title: I'm So Excited

text: Two years later, on the group's RIAA certified multi-Platinum album "Break Out," a slightly remixed and edited version of the song was included and re released as a single. This time, it peaked at No. 9 on the "Billboard" Hot 100 and No. 25 on the "Billboard" Adult Contemporary chart.


title: I'm So Excited

text: In March 2001, the song was included in the RIAA and National Endowment for the Arts project Songs of the Century, a list intended to "promote a better understanding of America's musical and cultural heritage." The song was ranked #264 out of 365 songs.


title: I'm So Excited

text: A music video was filmed for the 1984 re-release release of the single, directed by choreographer Kenny Ortega. In the clip, the sisters are seen getting ready for a formal party at a high society club. Anita Pointer is shown dressing and applying make up; Ruth Pointer, wearing only a nightgown, is shown rolling around on her bed and throwing her garments around; and June Pointer is wearing nothing at all and taking a bubble bath. Once the sisters arrive at the club, they are photographed, attracting the attention of the other party goers. By the video's end, they have the club on its feet jamming to the song. On the video also appears Dorian Harewood.


title: I'm So Excited

text: In 2001, Australian "Big Brother" season one contestant Sara-Marie Fedele teamed up with Australian girl group Sirens to record a cover version of "I'm So Excited", titled "I'm So Excited (The Bum Dance)". This cover was released through BMG Australia on October 15, 2001, as a CD single containing the original version, two remixes, and B-side "Feelin Free". Upon its release, the song reached number 12 on the Australian ARIA Singles Chart, spending four weeks in the top 50.


title: Kjeldahl method

text: The Kjeldahl method or Kjeldahl digestion () in analytical chemistry is a method for the quantitative determination of nitrogen contained in organic substances plus the nitrogen contained in the inorganic compounds ammonia and ammonium (NH/NH). Without modification, other forms of inorganic nitrogen, for instance nitrate, are not included in this measurement. Using an empirical relation between Kjeldahl nitrogen content and protein content it is an important method for analyzing proteins. This method was developed by Johan Kjeldahl in 1883.


title: Kjeldahl method

text: The method consists of heating a sample to 360–410 °C with concentrated sulfuric acid (HSO), which decomposes ("digests" or "destructs") the organic sample by oxidation to liberate the reduced nitrogen as ammonium sulfate. Hot concentrated sulfuric acid oxidizes carbon (as bituminous coal) and sulfur (see sulfuric acid's reactions with carbon):


title: Kjeldahl method

text: Catalysts like selenium, HgSO or CuSO are often added to make the digestion go faster. NaSO or KSO is also added to increase the boiling point of HSO. Digestion is complete when the liquor clarifies with the release of fumes. A distillation system depicted below is built.


title: Kjeldahl method

text: The end of the condenser is dipped into a known volume of standard acid (i.e. acid of known concentration). A weak acid like boric acid (HBO) in excess of ammonia is often used. Standardized HCl, HSO or some other strong acid can be used instead, but this is less commonplace. The sample solution is then distilled with a small amount of sodium hydroxide (NaOH). NaOH can also be added with a dropping funnel. NaOH reacts the ammonium (NH) to ammonia (NH), which boils off the sample solution. Ammonia bubbles through the standard acid solution and reacts back to ammonium salts with the weak or strong acid.


title: Kjeldahl method

text: Ammonium ion concentration in the acid solution, and thus the amount of nitrogen in the sample, is measured via titration. If boric acid (or some other weak acid) was used, direct acid–base titration is done with a strong acid of known concentration. HCl or HSO can be used. Indirect back titration is used instead if strong acids were used to make the standard acid solution: strong base of known concentration (like NaOH) is used to neutralize the solution. In this case, the amount of ammonia is calculated as the difference between the amount of HCl and NaOH. In the case of direct titration, it is not necessary to know the exact amount of weak acid (e.g. boric acid) because it does not interfere with the titration (it does have to be in excess of ammonia to efficiently trap it). Thus, one standard solution is needed (e.g. HCl) in the direct titration, while two are needed (e.g. HCl and NaOH) in the back-titration. One of the suitable indicators for these titration reactions is Tashiro's indicator.


title: Kjeldahl method

text: In practice, this analysis is largely automated; specific catalysts accelerate the decomposition. Originally, the catalyst of choice was mercuric oxide. However, while it was very effective, health concerns resulted in it being replaced by cupric sulfate. Cupric sulfate was not as efficient as mercuric oxide, and yielded lower protein results. It was soon supplemented with titanium dioxide, which is currently the approved catalyst in all of the methods of analysis for protein in the Official Methods and Recommended Practices of AOAC International.


title: Kjeldahl method

text: The Kjeldahl method's universality, precision and reproducibility have made it the internationally recognized method for estimating the protein content in foods and it is the standard method against which all other methods are judged. It is also used to assay soils, waste waters, fertilizers and other materials. It does not, however, give a measure of true protein content, as it measures nonprotein nitrogen in addition to the nitrogen in proteins. This is evidenced by the 2007 pet food incident and the 2008 Chinese milk powder scandal, when melamine, a nitrogen-rich chemical, was added to raw materials to fake high protein contents. Also, different correction factors are needed for different proteins to account for different amino acid sequences. Additional disadvantages, such as the need to use concentrated sulfuric acid at high temperature and the relatively long testing time (an hour or more), compare unfavorably with the Dumas method for measuring crude protein content.


title: Kjeldahl method

text: Total Kjeldahl nitrogen or TKN is the sum of nitrogen bound in organic substances, nitrogen in ammonia (NH-N) and in ammonium (NH-N) in the chemical analysis of soil, water, or waste water (e.g. sewage treatment plant effluent).


title: Kjeldahl method

text: Today, TKN is a required parameter for regulatory reporting at many treatment plants, and as a means of monitoring plant operations.


title: Kjeldahl method

text: TKN is often used as a surrogate for protein in food samples. The conversion from TKN to protein depends on the type of protein present in the sample and what fraction of the protein is composed of nitrogenous amino acids, like arginine and histidine. However, the range of conversion factors is relatively narrow. Example conversion factors, known as N factors, for foods range from 6.38 for dairy and 6.25 for meat, eggs, maize (corn) and sorghum to 5.83 for most grains; 5.95 for rice, 5.70 for wheat flour, and 5.46 for peanuts. In practice, 6.25 is used for almost all food and feed regardless of applicability. The factor 6.25 is specifically required by US Nutrition Label regulations in the absence of another published factor.


title: Kjeldahl method

text: The Kjeldahl method is poorly sensitive in the original version. Other detection methods have been used to quantify NH after mineralisation and distillation, achieving improved sensitivity: in-line generator of hydride coupled to a plasma atomic emission spectrometer (ICP-AES-HG, 10–25 mg/L), potentiometric titration (>0.1 mg of nitrogen), zone capillary electrophoresis (1.5 µg/ml of nitrogen), and ion chromatography (0.5 µg/ml).


title: Kjeldahl method

text: Kjeldahl method is not applicable to compounds containing nitrogen in nitro and azo groups and nitrogen present in rings (e.g. pyridine, quinoline, isoquinoline) as nitrogen of these compounds does not convert to ammonium sulfate under the conditions of this method.


title: Conestoga wagon

text: The Conestoga wagon is a specific design of heavy covered wagon that was used extensively during the late eighteenth century, and the nineteenth century, in the eastern United States and Canada. It was large enough to transport loads up to , and was drawn by horses, mules, or oxen. It was designed to help keep its contents from moving about when in motion and to aid it in crossing rivers and streams, though it sometimes leaked unless caulked.


title: Conestoga wagon

text: Most covered wagons used in the westward expansion of the United States were not Conestoga wagons but rather ordinary farm wagons fitted with canvas covers, as true Conestoga wagons were too heavy for the prairies.


title: Conestoga wagon

text: The first known, specific mention of "Conestoga wagon" was by James Logan on December 31, 1717, in his accounting log after purchasing it from James Hendricks. It was named after the Conestoga River or Conestoga Township (itself named after a small tribe of the Susquehannock) in Lancaster County, Pennsylvania, and is thought to have been introduced by German settlers for transports to Philadelphia.


title: Conestoga wagon

text: In colonial times the Conestoga wagon was popular for migration southward through the Great Appalachian Valley along the Great Wagon Road. After the American Revolution it was used to open up commerce to Pittsburgh and Ohio. In 1820 rates charged were roughly one dollar per 100 pounds per 100 miles, with speeds about per day. The Conestoga, often in long wagon trains, was the primary overland cargo vehicle over the Appalachian Mountains until the development of the railroad. The wagon was pulled by a team of up to eight horses or a dozen oxen. In Canada, the Conestoga wagons were used by Pennsylvania German migrants who left the United States for Southern Ontario, settling various communities in Niagara Region, Kitchener-Waterloo area and York Region (mostly in Markham and Stouffville).


title: Conestoga wagon

text: The Conestoga wagon was built with its floor curved upward to prevent the contents from tipping and shifting. Including its tongue, the average Conestoga wagon was 18 feet (5.4 m) long, 11 feet (3.3 m) high, and 4 feet (1.2 m) in width. It could carry up to of cargo. The seams in the body of the wagon were caulked with tar to protect them from leaking while crossing rivers. A tough white canvas cover was stretched across the wagon for protection from the elements. The frame and suspension were made of wood, and the wheels were often iron rimmed for greater durability. Water barrels were built on the side of the wagon, toolboxes held tools needed for repair, and a feed box on the back of the wagon was used to feed the horses. The early freight wagon was not intended to be ridden upon. The wagon had a brake handle on the left side between the two wheels and a teamster either walked beside the wagon or could ride standing (and could sit for a rough ride) on a pull-out board, called a "lazy board", that provided access to the brake handle. The left horse near the wagon was referred to as the "wheel horse" and was sometimes ridden. The Conestoga wagon began the custom of "driving" on the right-hand side of the road.


title: Conestoga wagon

text: For pulling the heavy freight wagons the Conestoga horse, a special breed of medium to heavy draft horses, was developed. The Conestoga was never an established breed, and they could be of several different colors. The beginnings were from the same Conestoga Valley as the wagon being Lancaster County. The horses were not bred by any scientific method, but by necessity.


title: Conestoga wagon

text: Samuel Gist, a prominent landowner, slave owner, banker, as well as a partner with George Washington, contributed to the eventual breeding of what became known as the Conestoga. Gist became famous by founding the Gist settlements, including one southwest of Leesburg, Ohio, and freeing his slaves, albeit only through his will after dying. The lineage of the Conestoga is not clear and there is more than one possibility. In 1774 there were 50 English stallions and 30 mares imported into Virginia. These either came from Byerley Turk, the Darley Arabian, or the Godolphin Arabian. Gist imported a Darley Arabian stud named "Bulle Rock" from England in 1732. Breeding this horse and descendants with Virginia mares led to larger size horses. These mares, bred with studs of Flemish ancestry, were reportedly brought to the United States by William Penn, but this has been asserted as lore.


title: Conestoga wagon

text: The demise of the Conestoga was predicted in 1864, relegated to oblivion by "modern inventions and recent innovations", through a Congressional printing and historical contribution by John Strohm. A few miles south of Conestoga, in Martic, Pennsylvania, a John Eshelman owned a sleek solid black Conestoga pictured as plate XXIV in the publication.


title: Destiny Fulfilled

text: Destiny Fulfilled is the fifth and final studio album by American R&B trio Destiny's Child. It was released on November 16, 2004, by Columbia Records and Sony Urban Music. A comeback release, it marked the return of Destiny's Child after the group went into hiatus, which allowed each member to release solo albums. Unlike their previous material, this record saw each member equally contributing to the songwriting and production. Destiny's Child further worked with frequent collaborators such as Rockwilder, Swizz Beatz and Rodney Jerkins as well as several new producers.


title: Destiny Fulfilled

text: For the album's theme, the members drew inspiration from the conversations they had during the first week of recording when they discussed about the happenings in their lives while being apart. Composed mostly of mid-tempo songs and ballads that are subsequent continuations of each other, altogether telling one complete story, "Destiny Fulfilled" is an R&B album. It was released to generally mixed reviews among music critics who criticized its mid-tempo ballads and lyrical content. The album was commercially successful; it reached number two on the US "Billboard" 200, and has since been certified triple Platinum in that region. It was also successful in different countries worldwide receiving certifications in Australia, Canada, Germany and the United Kingdom among others.


title: Destiny Fulfilled

text: As part of the album's promotion, the group performed songs from it on numerous award ceremonies and televised appearances in the US and Europe. They further embarked on the tour Destiny Fulfilled... and Lovin' It in 2005 with 67 dates across four continents worldwide. "Destiny Fulfilled" spawned four singles—the lead single "Lose My Breath", "Soldier", "Girl" and "Cater 2 U". After the tour, the group disbanded.


title: Destiny Fulfilled

text: While recording their third studio album "Survivor" in late 2000, Beyoncé announced that Destiny's Child would eventually go on a hiatus that would allow each member to release a solo album, which they hoped would further increase interest in the group. The idea of solo releases emanated from the group's manager, Beyoncé's father, Mathew Knowles. Kelly Rowland further explained in an interview that Destiny's Child has been present in the media for a long time and they wanted to "give the public eye a rest from DC for a minute". During that same interview, she acknowledged that the trio would return to the studio in fall 2003 to start with the work on a new album.


title: Destiny Fulfilled

text: Two members of the group, Beyoncé and Rowland each released one album, while Michelle Williams released two. While each member achieved domestic success, Beyoncé's had been regarded as the most successful with the release of "Dangerously in Love" (2003), which enjoyed international commercial success and acclaim. This, along with their other ongoing projects, led to speculation over the disbandment of Destiny's Child. Amidst rumors and speculations, Rowland announced in 2004 their return to the studio to record what would become their fourth and final album. The group claimed that the reunion was destined to happen, and that their affinity to each other kept them together.


title: Destiny Fulfilled

text: After this album, the group planned to part ways after their fourteen-year career to facilitate their solo careers. Beyoncé has noted that their destinies were already fulfilled; however, Destiny's Child claimed that naming the album "Destiny Fulfilled" was not a coincidence. Beyoncé has said that "the group felt it still had something to offer musically" with the album before adding: "We did this record for ourselves, not to sell a million the first week out... That doesn't mean as much to us as just the fact that three friends got back together to do another record. That was our destiny.". Rowland commented: "We were like, 'You know what, we're getting older and we want to end on a high note.' We want to give our fans a great final record". Beyoncé, also commented regarding the finality of their career: "Who knows what will happen in three, five or 10 years? The main thing is that we maintain our friendship and that we do it because we want to – not because it's a good business move."


title: Destiny Fulfilled

text: Production of the album began in summer of 2004 with Destiny's Child taking help from frequent collaborators including Rockwilder, Swizz Beatz and Rodney Jerkins. The group worked on the album within a period of three weeks. Jerkins, who had worked with Beyoncé for her solo album "Dangerously in Love", concerned how he would manage the production, saying, "How is this going to work?' Cause Beyoncé, she blew up solo, so how's it going to work in a group together?". He stated that once he got inside the studio, however, his skepticism vanished as he saw the group's "excitement being back in the studio together", calling the process "natural". The members of the group stated that the first week of recording was spent solely on conversations about the happenings in their lives while being apart from each other as they hadn't spent quality time for a long period. This further inspired them to record the conversations and use it as the main theme of the record.


title: Destiny Fulfilled

text: Differing from "Survivor" in that previously Beyoncé had taken an active role in writing and producing, "Destiny Fulfilled" saw each member contributing inputs culled from personal experiences and individual opinions and points of view not dependent from the others'. In most cases, producers of the album would send them a CD containing a track that would be the group's basis in the songwriting process; without the producer's supervision of which part to sing, that formed a new direction of their style different from their previous records. The traditional approach where each member sang one verse and chimed in the chorus was replaced; in some songs in "Destiny Fulfilled", their vocals were alternated in every line of the lyrics, a technique similar to hip hop artists. Destiny's Child took the role of executive producing alongside their manager, Mathew Knowles. Beyoncé, who vocally produced the songs, commented that it was important for her to make sure their voices were audible and identifiable. Taking it as one of her goals, the group decided to focus on mid-tempo songs and on few dance numbers and ballads—which they considered people cannot sing with. Beyoncé elaborated "We wanted to make sure that the songs would be something that we were proud of 10 years from now, 20 years from now. We wanted it to be something that people can really feel an emotion to. Up-tempo songs can do that, but they more make you wanna dance." As Rowland was recently engaged in the time of the writing of the album, it further influenced her songwriting. She also cited that being apart from the group affected the album as well: "All of us have been in three different places ... so there's a lot to talk about, a lot that's gone on, personally. I think it's important to talk about that on this new record, to put what we've been going through separately into the new record."


title: Destiny Fulfilled

text: During an interview with MTV, Beyoncé stated that the songs put altogether tell a complete story and noted that each song was a subsequent continuation to the next one. She concluded, "[The album continues with] this whole journey of this group of women trying to find love. And truly they find it because they love themselves and find it in themselves. It's friendship, it's love, it's maturity and growth, and it's everything that we wanted it to be." For the music of the album, the group tried challenging themselves, working with different arrangements, trying to create an original sound; to succeed in this, they were influenced by The Emotions, Jodeci and SWV mixing elements of their music. "Destiny Fulfilled" is predominantly an R&B concept album tracing a woman's relationship journey. Critics further found elements of soul music, dance and hip-hop. The album is mostly composed of mid and slowtempo balladry following the opening two songs; Caroline Sullivan of "The Guardian" felt that the ballads showcased "the girliness in the trio, musically and lyrically". Eric Henderson of Slant Magazine found elements of middle of the road music in the ballads.


title: Destiny Fulfilled

text: The album opens with the up-tempo dance song "Lose My Breath", a track detailing a man full of empty promises to a woman. It is musically complete with military, marching-band drums and keyboard stabs and the backing track contains various sound effects. "Soldier", the second track with T.I. and Lil Wayne, the only featured artists on the album, contains elements from Southern hip hop and Crunk&B. Unsatisfied and unfulfilled with the lover from the opening song, the protagonists ask for a decent soldier, further singing about finding a gangster. After finding the soldier, the third song, the R&B number "Cater 2 U", lyrically is about submissively serving the man considered as such. Inspired by him, the protagonists sing about doing various things to make him happy musically accompanied by synthesizer as the song builds a crescendo.


title: Destiny Fulfilled

text: The fourth song "T-Shirt" is complete with inorganic drum sounds, guitar and backwards loop as the trio sings about sleeping in bed with their man's T-shirt, "craving his presence, and inhailing his scent". "Is She the Reason" is an R&B ballad which was noted to have a similar chord progression to materials by The Beatles, which lyrically speaks on being in competition with another woman for her mans love & attention. It contains a trumpet-laden sample from Melba Moore's song "I Don't Know No One Else to Turn To". The next song, "Girl" was noted for its Motown influence and a theme talking about friendship. "If", complete with strings, lyrically talks about men who don't appreciate their female lovers until their relationship ends and they realize their mistakes. "Free" was described as a "soul classic from 1975" with critics also noting elements of 1970s funk music, as the trio speaks on being "set free" after being in a relationship where her lover never tending to her desires like she does for him. The midtempo number "Through with Love" was noted for having an "angry" nature as it talks about a break-up. It contains an undulating piano line as the members of the group sing with restrained vocals and later religious redemption with elements of gospel. In "Love", "capital "L" kicks the daylights out of the forces of fear, doubt and disappointment", as the group "thank[s] God for love". They further sing about how people "can't truly love another until [they] love God and then [themselves]". They further proclaim that they have found love and are "madly in it".


title: Destiny Fulfilled

text: The track listing of "Destiny Fulfilled" was revealed on October 15, 2004. The album was first released in Japan on November 10, 2004. It was released on November 16, 2004, in North America via Columbia Records. Although the original release was intended to be one day earlier, Columbia Records was concerned about "potential for Internet leaks and 'burned' CD counterfeits" that could "lead consumers to experience inferior and incomplete versions of the album" which led to the postponement of "Destiny Fulfilled".


title: Destiny Fulfilled

text: The group performed "Lose My Breath" on ABC's 2004 National Football League "Opening Kickoff" special after its online release on September 9, 2004, to break their yearlong hiatus. On October 25, 2004, they appeared at the Radio Music Awards in Las Vegas performing the song with an a cappella jazz opening. The following month they performed three songs from their previous albums and finished with "Lose My Breath" on "The Oprah Winfrey Show" where they also sat down for an interview with Oprah Winfrey. On November 8, 2004, the trio appeared on "Total Request Live" ("TRL") and performed the song along with "Say My Name". They went to the German entertainment TV show "Wetten, dass..?" on November 13, 2004, and performed "Lose My Breath". At BET's "106 & Park" Destiny's Child performed "Soldier" on November 15, 2004. They also performed the song on CBSs "The Early Show" on December 8, 2004. In early February 2005 they gave another performance of "Soldier" at the British show "Top of the Pops". At the 2005 NBA All-Star Game on February 20, 2005, they sang both "Soldier" and "Lose My Breath". They performed the latter song again at the 2005 ESPY Awards on July 13 with the ceremony being aired on ESPN four days later. "Cater 2 U" was performed on June 28 during the 2005 BET Awards in Los Angeles.


title: Destiny Fulfilled

text: When the advanced release date of the album was announced, the group confirmed the initial dates of their worldwide tour Destiny Fulfilled... and Lovin' It in connection with "Destiny Fulfilled"s promotion. Promotions of the tour were aired over the radio and television across the United States and the group further collaborated with McDonald's, which served as its sponsor. The tour's set list included songs from "Destiny Fulfilled" as well as Destiny's Child's previous albums and songs from the solo albums of each member performed individually. Numerous costume changes occurred throughout the show; the concert exhibited products from Beyoncé's clothing line from the House of Deréon, a company she co-founded with her mother Tina Knowles. A performance from the tour was filmed in Atlanta on July 15, 2005, and the DVD "Live in Atlanta" chronicling the concert was released on March 28, 2006.


title: Destiny Fulfilled

text: The album's lead single, "Lose My Breath", premiered on AOL Music on September 9, 2004, and it was released on September 21. Its high-mark debut at number 30 on the "Billboard" Hot 100 prior to its release gave the album an early boost. The single peaked at number three on the chart for the week ending November 6, 2004 giving the group their ninth top ten single. "Lose My Breath" topped the Hot Dance Club Songs chart for the week ending January 8, 2005 and was later certified gold by the Recording Industry Association of America (RIAA) on April 28, 2005, selling 500,000 copies in the US. It was also successful across Europe, peaking at number one on the European Hot 100 Singles chart for the week ending December 4, 2004 spending four consecutive weeks on top. It managed to top the charts in Belgium, Ireland, Italy and Switzerland and it further appeared in the top ten in almost every other chart. The American Broadcasting Company (ABC) used the song as the music for their introductory montage at the 2004 NBA Playoffs and through the first few weeks of the 2005 NBA Playoffs.


title: Destiny Fulfilled

text: "Soldier", released on November 9, 2004, peaked at the third position on the "Billboard" Hot 100 chart becoming the band's tenth top ten single on that chart. It further became the second single from the album to top the Hot Dance Club Songs chart for the week ending February 26, 2005. The RIAA gave it a gold certification for selling 500,000 digital copies in the US. "Soldier" further peaked at number four on the UK Singles Chart, number 3 on the ARIA Charts in Australia and appeared in the top 20 in many European countries. The third single from the album, "Girl" was sent to radio on March 15, 2005 and later released commercially on May 2, 2005, in the UK and on May 17 in the US. It was successful on the ARIA Chart peaking at number five and number six both on the UK Singles Chart and the New Zealand Singles Chart in addition to appearing in other European charts. In the US, it peaked at number 23 on the "Billboard" Hot 100 chart becoming the lowest charting single there from the album. The fourth and final single from "Destiny Fulfilled" was "Cater 2 U" released in the US and Italy only beginning on June 7, 2005. It peaked at number 14 on the "Billboard" Hot 100 and number three on the Hot R&B/Hip-Hop Songs further being certified gold by the RIAA.


title: Destiny Fulfilled

text: "Destiny Fulfilled" received mixed reviews from music critics. At Metacritic, which assigns a weighted mean rating out of 100 to reviews from mainstream critics, the album received an average score of 52 based on 17 reviews. Dimitri Ehrlich of "Vibe" magazine complimented the production of the album, saying that it "showcases advanced production values" with "impressive" songwriting and vocal abilities and concluded that it "offers divine satisfaction". A writer of "Billboard" felt that "Destiny Fulfilled" worked as "a testament to Beyoncé's evolving multiple talents". Stephen Thomas Erlewine of AllMusic praised Rowland's and Williams' abilities as vocalists and their contributions to the choruses, but felt that Beyoncé "steals every song on Destiny Fulfilled" further commending her for sounding "larger than life even when she's quiet"; however he concluded, "as a whole, the album winds up sounding too reserved and heavy-handed, which makes it a disappointment". Andy Battaglia of "The A.V. Club" wrote in his review that ""Destiny Fulfilled" sounds distant and detached" further criticizing its mid-tempo ballads for sounding "uninterrupted at best, uninspired at worst". Kelefa Sanneh of "The New York Times" commented that it is "a surprisingly perfunctory disc that never quite justifies its existence". Alan Ranta of Tiny Mix Tapes doubted Beyoncé's lyrical sincerity, saying, "the success of this album depends once again on the complete suspension of die-hard fans' disbelief that Beyoncé 'Your Ad Here' Knowles could ever actually truly love another human being as much as she loves herself and her possessions."


title: Destiny Fulfilled

text: Caroline Sullivan of "The Guardian" commented that the lead vocals of the songs were likely to be sung by each member equally, noting that it made the album a "democratic" one; however she criticized them for squandering "the extent of their talents" on the album. Tom Sinclair of "Entertainment Weekly" also noticed its "overall air of democracy at work" and noted that "Destiny Fulfilled" "often moves at a molasses-like pace, weighted down with a preponderance of exquisitely executed but ultimately dull ballads". Jenny Eliscu of "Rolling Stone" magazine echoed his comments, saying, "In all but a couple of songs, the verses are divided into three sections, with Beyonce leading things off, followed by Rowland, then Williams". She noted that after a couple of upbeat songs, "the album slumps into an endless string of overwrought R&B ballads where the only saving grace is ... these ladies can harmonize like nobody's business." Eric Henderson of Slant Magazine has commented that the ballads of the album build into "the same sort of standoffish sexual supply-and-demand bartering that has marred their worst tracks". Most of the critics questioned why Beyoncé had to return to Destiny's Child after achieving the most success among the members of the group. Henderson lambasted Beyoncé to performing again with the group with the "full intention" of taking advantage to bolster her "divette" status to superstardom. In May 2006, "Destiny Fulfilled" was listed at number 24 on a list titled "The 50 Worst Albums Ever!" compiled by "Q" magazine.


title: Destiny Fulfilled

text: The album won in the category for Favorite Soul/R&B Album at the 2005 American Music Awards where Destiny's Child also won the Favorite Soul/R&B Band award. At the 2005 Soul Train Music Awards "Destiny Fulfilled" received an award for Best R&B/Soul Album while "Soldier" received Best R&B/Soul Single. The album was nominated in the category for Best Contemporary R&B Album at the 48th Grammy Awards in 2006 but it lost to Mariah Carey's "The Emancipation of Mimi". Its singles "Soldier" and "Cater 2 U" further received nominations in three different categories at the same ceremony. The previous year, "Lose My Breath" was nominated in the category for Best R&B Vocal Performance by a Duo Or Group at the 47th Annual Grammy Awards.


title: Destiny Fulfilled

text: In the United States, the album debuted at number 19 on the "Billboard" 200 for the week ending November 27, 2004 for amassing sales of 61,000 copies prior to a whole tracking week. In its first official week of sales, "Destiny Fulfilled" sold over 497,000 copies, with an increase of 713% compared to its early sales; the album's chart position rocketed to number two on the "Billboard" 200 for the week ending December 4, 2004. In the same week, it debuted at number one on the Top R&B/Hip-Hop Albums chart becoming the group's second chart topper following "Survivor" in 2001. After being removed from the top position for three consecutive weeks, "Destiny Fulfilled" returned to number one for the week ending January 1, 2005. On January 14, 2005, it was certified triple Platinum by the Recording Industry Association of America (RIAA) for shipment of 3,000,000 copies. It emerged as the seventh best-selling album and third best-selling R&B album in 2005. As of October 2009, the album has sold 3.1 million copies in the US according to Nielsen SoundScan. It was ranked at number 133 on the decade-end chart of the best-selling albums in that country for the period between 2000 and 2009. The album peaked at number 3 on the Canadian Albums Chart and was awarded Platinum certification by Music Canada selling 100,000 copies.


title: Destiny Fulfilled

text: In the UK, "Destiny Fulfilled" debuted at number five on the UK Albums Chart on November 27, 2004, which also became its peak position in that country. Having spent a total of 21 weeks on the chart, it became the group's third album to enter the top ten in the UK until 2005 and the fourth one in their entire career. On November 19, 2004, the British Phonographic Industry (BPI) certified it Platinum for selling 300,000 copies. On the Irish Albums Chart, "Destiny Fulfilled" debuted and peaked at number 6 on November 18, 2004, becoming Destiny's Child third consecutive top ten album in Ireland. It was also successful in other European countries, peaking at number 3 on the German Albums Chart, further being certified Platinum in that region. In France, "Destiny Fulfilled" peaked at number nine in its first week on November 14, 2004. It was last seen on the country's albums chart at number 163 on September 3, 2005.


title: Destiny Fulfilled

text: On the Australian ARIA Albums Chart, "Destiny Fulfilled" debuted at number 11 on November 28, 2004, a position which later became its peak. Spending a total of 31 weeks through 2004 and 2005 ascending and descending the chart, the album was certified Platinum by the Australian Recording Industry Association (ARIA) for shipment of 70,000 copies in that region. In New Zealand, "Destiny Fulfilled" peaked at number 21 on April 25, 2005, and the Recorded Music NZ (RMNZ) awarded it with a gold certification for 7,500 copies sold. In Japan, the album debuted and peaked at number four on the Oricon chart due to the success of "Lose My Breath" which reached number one on the singles chart there. The album has sold over 625,000 copies there and was certified double Platinum by Oricon making it Destiny's Child's biggest success there to date. It won in the category Rock/Pop Album of the Year International at the 19th Japan Gold Disc Award in 2005 organized by the Recording Industry Association of Japan (RIAJ). "Destiny Fulfilled" was named the eighth best-selling album of 2004 worldwide by the International Federation of the Phonographic Industry (IFPI). The album has sold over 7,000,000 copies worldwide.


title: Destiny Fulfilled

text: In a visit at the Palau Sant Jordi in Barcelona, Spain on July 11, 2005, Rowland announced before 16,000 spectators that Destiny Fulfilled... and Lovin' It would be Destiny's Child last tour together, revealing their formal disbandment. After their final North American leg, the group parted ways. In a statement released to MTV, the band said that the tour had provided them the opportunity to depart from Destiny's Child on a "high note". They also talked about the moment when the group started their musical endeavor and their realizations of pursuing individual careers after working together for several years. Destiny's Child thanked fans for their support while not closing the chance of seeing them continuing each member's goals in music, film, and television. In another interview they explained that their disbandment was planned during the making of the album. While in the studio, they discussed individual aspirations and realized that remaining as a group would prevent them in pursuing those interests. Rowland revealed that they wanted to break up while they were still successful and "friends [with each other]". Beyoncé, however, emphasized that "Destiny Fulfilled" would not be their last album and disclosed the idea of a possible reunion.


title: Dum spiro spero

text: Dum spiro spero, which translates to "While I breathe, I hope", is a Latin phrase of indeterminate origin. It is the motto of various places and organisations, including the U.S. state of South Carolina.


title: Dum spiro spero

text: The sense of "dum spiro spero" can be found in the work of Greek poet Theocritus (3rd Century BC), who wrote: "While there's life there's hope, and only the dead have none." That sentiment seems to have become common by the time of Roman statesman Cicero (106 – 43 BC), who wrote Atticus: "As in the case of a sick man one says, 'While there is life there is hope' ["dum anima est, spes esse"], so, as long as Pompey was in Italy, I did not cease to hope."


title: Dum spiro spero

text: The phrase had begun appearing in its current form by at least the 1780s, as it is present on a representation of the seal of South Carolina printed in March 1785. At some point, it also became the motto of the town of St Andrews, Scotland, and is visible on heraldry around the town of from the mid-19th century onwards.


title: Dum spiro spero

text: "Dum spiro spero" is used as a motto by armigerous families including the Corbet baronets of Moreton Corbet (both creations), the Hoare baronets of Annabella, Co. Cork, and the Viscounts Dillon.


title: Dum spiro spero

text: Individuals who used the motto include Charles I, King of England; Sir James Brooke, Rajah of Sarawak, and the merchant seaman and privateer, later Royal Governor of the Bahama Islands, Woodes Rogers.


title: Kara Sea

text: The Kara Sea (, "Karskoye more") is a marginal sea, separated from the Barents Sea to the west by the Kara Strait and Novaya Zemlya, and from the Laptev Sea to the east by the Severnaya Zemlya archipelago. Ultimately the Kara, Barents and Laptev Seas are all extensions of the Arctic Ocean north of Siberia.


title: Kara Sea

text: The Kara Sea's northern limit is marked geographically by a line running from Cape Kohlsaat in Graham Bell Island, Franz Josef Land, to Cape Molotov (Arctic Cape), the northernmost point of Komsomolets Island in Severnaya Zemlya.


title: Kara Sea

text: Its main ports are Novy Port and Dikson and it is important as a fishing ground although the sea is ice-bound for all but two months of the year. The Kara Sea contains the East-Prinovozemelsky field (an extension of the West Siberian Oil Basin), containing significant undeveloped petroleum and natural gas. In 2014, US government sanctions resulted in Exxon having until September 26 to discontinue its operations in the Kara Sea.


title: Kara Sea

text: It is named after the Kara river (flowing into Baydaratskaya Bay), which is now relatively insignificant but which played an important role in the Russian conquest of northern Siberia. The Kara river name is derived from a Nenets word meaning 'hummocked ice'.


title: Kara Sea

text: In Turkic languages, for example, in Turkish, Tatar and Bashkir and others, the name of the sea is an exonym and literally translated as 'the Black Sea' (). By analogy with the Black Sea, "Kara Deniz" is also used to designate the Kara Sea. Thus, in the Turkic languages there are two black seas (one in the North of Turkey, the other in the North of Eurasia). This is due to the fact that color definitions are associated with the symbolic color characteristic of the countries of the world, where "kara" ('black') is north.


title: Kara Sea

text: There are many islands and island groups in the Kara Sea. Unlike the other marginal seas of the Arctic, where most islands lie along the coasts, in the Kara Sea many islands, like the Arkticheskiy Institut Islands, the Izvesti Tsik Islands, the Kirov Islands, Uedineniya or Lonely Island, Wiese Island, and Voronina Island are located in the open sea of its central regions.


title: Kara Sea

text: The largest group in the Kara Sea is by far the Nordenskiöld Archipelago, with five large subgroups and over ninety islands. Other important islands in the Kara Sea are Bely Island, Dikson Island, Taymyr Island, the Kamennyye Islands and Oleni Island. Despite the high latitude, all islands are unglaciated except for Ushakov Island at the extreme northern limit of the Kara Sea.


title: Kara Sea

text: Water circulation patterns in the Kara Sea are complex. The Kara Sea tends to be sea ice covered between September and May, and between May and August heavily influenced by freshwater run-off (roughly 1200 km yr) from the Russian rivers (e.g., Ob, Yenisei, Pyasina, Pur, and Taz). The Kara Sea is also affected by the water inflow from the Barents Sea, which brings 0.6 Sv in August and 2.6 Sv in December. The advected water originates from the Atlantic, but it was cooled and mixed with freshwater in the Barents Sea before it reaches the Kara Sea. Simulations with the Hamburg shelf ocean model (HAMSOM) suggest that no typical water current pattern consists in the Kara Sea throughout the year. Depending on the freshwater run-off, the dominant wind patterns, and the sea ice formation, the water currents change.


title: Kara Sea

text: The Kara Sea was formerly known as Oceanus Scythicus or Mare Glaciale and it appears with these names in 16th century maps. Since it is closed by ice most of the year it remained largely unexplored until the late nineteenth century.


title: Kara Sea

text: In 1556 Stephen Borough sailed in the "Searchthrift" to try to reach the Ob River, but he was stopped by ice and fog at the entrance to the Kara Sea. Not until 1580 did another English expedition, under Arthur Pet and Charles Jackman, attempt its passage. They too failed to penetrate it, and England lost interest in searching for the Northeast Passage.


title: Kara Sea

text: In 1736–1737 Russian Admiral Stepan Malygin undertook a voyage from Dolgy Island in the Barents Sea. The two ships in this early expedition were the "Perviy", under Malygin's command and the "Vtoroy" under Captain A. Skuratov. After entering the little-explored Kara Sea, they sailed to the mouth of the Ob River. Malygin took careful observations of these hitherto almost unknown areas of the Russian Arctic coastline. With this knowledge he was able to draw the first somewhat accurate map of the Arctic shores between the Pechora River and the Ob River.


title: Kara Sea

text: In 1878, Finnish explorer Adolf Erik Nordenskiöld on ship "Vega" sailed across the Kara Sea from Gothenburg, along the coast of Siberia, and despite the ice packs, got to 180° longitude by early September. Frozen in for the winter in the Chukchi Sea, Nordenskiöld waited and bartered with the local Chukchi people. The following July, the Vega was freed from the ice, and continued to Yokohama, Japan. He became the first to force the Northeast Passage. The largest group of islands in the Kara Sea, the Nordenskiöld Archipelago, has been named in his honour. The year 1912 was a tragic one for Russian explorers in the Kara Sea. In that fateful year unbroken consolidated ice blocked the way for the Northern Sea Route and three expeditions that had to cross the Kara Sea became trapped and failed: Sedov's on vessel "St. Foka", Brusilov's on the "St. Anna", and Rusanov's on the "Gercules". Georgy Sedov intended to reach Franz Josef Land on ship, leave a depot over there, and sledge to the pole. Due to the heavy ice the vessel could only reach Novaya Zemlya the first summer and wintered in Franz Josef Land. In February 1914 Sedov headed to the North Pole with two sailors and three sledges, but he fell ill and died on Rudolf Island. Georgy Brusilov attempted to navigate the Northeast Passage, was trapped in the Kara Sea, and drifted northward for more than two years reaching latitude 83° 17' N. Thirteen men, headed by Valerian Albanov, left the vessel and started across the ice to Franz Josef Land, but only Albanov and one sailor (Alexander Konrad) survived after a gruesome three-month ordeal. The survivors brought the ship log of "St. Anna", the map of her drift, and daily meteorological records, but the destiny of those who stayed on board remains unknown. In the same year the expedition of Vladimir Rusanov was lost in the Kara Sea. The prolonged absence of those three expeditions stirred public attention, and a few small rescue expeditions were launched, including Jan Nagórski's five air flights over the sea and ice from the NW coast of Novaya Zemlya.


title: Kara Sea

text: After the Russian Revolution in 1917, the scale and scope of exploration of the Kara Sea increased greatly as part of the work of developing the Northern Sea Route. Polar stations, of which five already existed in 1917, increased in number, providing meteorologic, ice reconnaissance, and radio facilities. By 1932 there were 24 stations, by 1948 about 80, and by the 1970s more than 100. The use of icebreakers and, later, aircraft as platforms for scientific work were developed. In 1929 and 1930 the Icebreaker Sedov carried groups of scientists to Severnaya Zemlya, the last major piece of unsurveyed territory in the Soviet Arctic; the archipelago was completely mapped under Georgy Ushakov between 1930 and 1932.


title: Kara Sea

text: Particularly worth noting are three cruises of the Icebreaker "Sadko", which went farther north than most; in 1935 and 1936 the last unexplored areas in the northern Kara Sea were examined and the small and elusive Ushakov Island was discovered.


title: Kara Sea

text: In the summer of 1942, German Kriegsmarine warships and submarines entered the Kara Sea to destroy as many Russian vessels as possible. This naval campaign was named "Operation Wunderland". Its success was limited by the presence of ice floes, as well as bad weather and fog. These effectively protected the Soviet ships, preventing the damage that could have been inflicted on the Soviet fleet under fair weather conditions.


title: Kara Sea

text: In October 2010, the Russian government awarded a license to Russian oil company Rosneft for developing the East-Prinovozemelsky oil and gas structure in the Kara Sea.


title: Kara Sea

text: There is concern about radioactive contamination from nuclear waste the former Soviet Union dumped in the sea and the effect this will have on the marine environment. According to an official "White Paper" report compiled and released by the Russian government in March 1993, the Soviet Union dumped six nuclear submarine reactors and ten nuclear reactors into the Kara Sea between 1965–1988. Solid high- and low-level wastes unloaded from Northern Fleet nuclear submarines during reactor refuelings were dumped in the Kara Sea, mainly in the shallow fjords of Novaya Zemlya, where the depths of the dumping sites range from 12 to 135 meters, and in the Novaya Zemlya Trough at depths of up to 380 meters. Liquid low-level wastes were released in the open Barents and Kara Seas. A subsequent appraisal by the International Atomic Energy Agency showed that releases are low and localized from the 16 naval reactors (reported by the IAEA as having come from seven submarines and the icebreaker "Lenin") which were dumped at five sites in the Kara Sea. Most of the dumped reactors had suffered an accident.


title: Kara Sea

text: The Soviet submarine K-27 was scuttled in Stepovogo Bay with its two reactors filled with spent nuclear fuel. At a seminar in February 2012 it was revealed that the reactors on board the submarine could re-achieve criticality and explode (a buildup of heat leading to a steam explosion vs. nuclear). The catalogue of waste dumped at sea by the Soviets, according to documents seen by Bellona, includes some 17,000 containers of radioactive waste, 19 ships containing radioactive waste, 14 nuclear reactors, including five that still contain spent nuclear fuel; 735 other pieces of radioactively contaminated heavy machinery, and the K-27 nuclear submarine with its two reactors loaded with nuclear fuel.


title: Kara Sea

text: The Great Arctic State Nature Reserve—the largest nature reserve of Russia—was founded on May 11, 1993 by Resolution No. 431 of the Government of the Russian Federation (RF). The Kara Sea Islands section (4,000 km²) of the Great Arctic Nature Reserve includes: the Sergei Kirov Archipelago, the Voronina Island, the Izvestiy TSIK Islands, the Arctic Institute Islands, the Svordrup Island, Uedineniya (Ensomheden) and a number of smaller islands. This section represents rather fully the natural and biological diversity of Arctic sea islands of the eastern part of the Kara Sea.


title: Kara Sea

text: Nearby, the Franz Josef Land and Severny Island in northern Novaya Zemlya are also registered as a sanctuary, the Russian Arctic National Park.


title: Carcinogenesis

text: Carcinogenesis, also called oncogenesis or tumorigenesis, is the formation of a cancer, whereby normal cells are transformed into cancer cells. The process is characterized by changes at the cellular, genetic, and epigenetic levels and abnormal cell division. Cell division is a physiological process that occurs in almost all tissues and under a variety of circumstances. Normally, the balance between proliferation and programmed cell death, in the form of apoptosis, is maintained to ensure the integrity of tissues and organs. According to the prevailing accepted theory of carcinogenesis, the somatic mutation theory, mutations in DNA and epimutations that lead to cancer disrupt these orderly processes by interfering with the programming regulating the processes, upsetting the normal balance between proliferation and cell death. This results in uncontrolled cell division and the evolution of those cells by natural selection in the body. Only certain mutations lead to cancer whereas the majority of mutations do not.


title: Carcinogenesis

text: Variants of inherited genes may predispose individuals to cancer. In addition, environmental factors such as carcinogens and radiation cause mutations that may contribute to the development of cancer. Finally random mistakes in normal DNA replication may result in cancer causing mutations. A series of several mutations to certain classes of genes is usually required before a normal cell will transform into a cancer cell. Recent comprehensive patient-level classification and quantification of driver events in TCGA cohorts revealed that there are on average 12 driver events per tumor, of which 0.6 are point mutations in oncogenes, 1.5 are amplifications of oncogenes, 1.2 are point mutations in tumor suppressors, 2.1 are deletions of tumor suppressors, 1.5 are driver chromosome losses, 1 is a driver chromosome gain, 2 are driver chromosome arm losses, and 1.5 are driver chromosome arm gains. Mutations in genes that regulate cell division, apoptosis (cell death), and DNA repair may result in uncontrolled cell proliferation and cancer.


title: Carcinogenesis

text: Cancer is fundamentally a disease of regulation of tissue growth. In order for a normal cell to transform into a cancer cell, genes that regulate cell growth and differentiation must be altered. Genetic and epigenetic changes can occur at many levels, from gain or loss of entire chromosomes, to a mutation affecting a single DNA nucleotide, or to silencing or activating a microRNA that controls expression of 100 to 500 genes. There are two broad categories of genes that are affected by these changes. Oncogenes may be normal genes that are expressed at inappropriately high levels, or altered genes that have novel properties. In either case, expression of these genes promotes the malignant phenotype of cancer cells. Tumor suppressor genes are genes that inhibit cell division, survival, or other properties of cancer cells. Tumor suppressor genes are often disabled by cancer-promoting genetic changes. Finally Oncovirinae, viruses that contain an oncogene, are categorized as oncogenic because they trigger the growth of tumorous tissues in the host. This process is also referred to as viral transformation.


title: Carcinogenesis

text: There is a diverse classification scheme for the various genomic changes that may contribute to the generation of cancer cells. Many of these changes are mutations, or changes in the nucleotide sequence of genomic DNA. There are also many epigenetic changes that alter whether genes are expressed or not expressed. Aneuploidy, the presence of an abnormal number of chromosomes, is one genomic change that is not a mutation, and may involve either gain or loss of one or more chromosomes through errors in mitosis. Large-scale mutations involve either the deletion or duplication of a portion of a chromosome. Genomic amplification occurs when a cell gains many copies (often 20 or more) of a small chromosomal region, usually containing one or more oncogenes and adjacent genetic material. Translocation occurs when two separate chromosomal regions become abnormally fused, often at a characteristic location. A well-known example of this is the Philadelphia chromosome, or translocation of chromosomes 9 and 22, which occurs in chronic myelogenous leukemia, and results in production of the BCR-abl fusion protein, an oncogenic tyrosine kinase. Small-scale mutations include point mutations, deletions, and insertions, which may occur in the promoter of a gene and affect its expression, or may occur in the gene's coding sequence and alter the function or stability of its protein product. Disruption of a single gene may also result from integration of genomic material from a DNA virus or retrovirus, and such an event may also result in the expression of viral oncogenes in the affected cell and its descendants.


title: Carcinogenesis

text: DNA damage is considered to be the primary cause of cancer. More than 60,000 new naturally-occurring instances of DNA damage arise, on average, per human cell, per day, due to endogenous cellular processes (see article DNA damage (naturally occurring)).


title: Carcinogenesis

text: Additional DNA damage can arise from exposure to exogenous agents. As one example of an exogenous carcinogenic agent, tobacco smoke causes increased DNA damage, and this DNA damage likely cause the increase of lung cancer due to smoking. In other examples, UV light from solar radiation causes DNA damage that is important in melanoma, "Helicobacter pylori" infection produces high levels of reactive oxygen species that damage DNA and contribute to gastric cancer, and the "Aspergillus flavus" metabolite aflatoxin is a DNA damaging agent that is causative in liver cancer.


title: Carcinogenesis

text: DNA damage can also be caused by substances produced in the body. Macrophages and neutrophils in an inflamed colonic epithelium are the source of reactive oxygen species causing the DNA damage that initiates colonic tumorigenesis, and bile acids, at high levels in the colons of humans eating a high-fat diet, also cause DNA damage and contribute to colon cancer.


title: Carcinogenesis

text: Such exogenous and endogenous sources of DNA damage are indicated in the boxes at the top of the figure in this section. The central role of DNA damage in progression to cancer is indicated at the second level of the figure. The central elements of DNA damage, epigenetic alterations and deficient DNA repair in progression to cancer are shown in red.


title: Carcinogenesis

text: A deficiency in DNA repair would cause more DNA damage to accumulate, and increase the risk for cancer. For example, individuals with an inherited impairment in any of 34 DNA repair genes (see article DNA repair-deficiency disorder) are at increased risk of cancer, with some defects causing an up to 100% lifetime chance of cancer (e.g. p53 mutations). Such germline mutations are shown in a box at the left of the figure, with an indication of their contribution to DNA repair deficiency. However, such germline mutations (which cause highly penetrant cancer syndromes) are the cause of only about "one percent" of cancers.


title: Carcinogenesis

text: The majority of cancers are called non-hereditary or "sporadic cancers". About 30% of sporadic cancers do have some hereditary component that is currently undefined, while the majority, or 70% of sporadic cancers, have no hereditary component.


title: Carcinogenesis

text: In sporadic cancers, a deficiency in DNA repair is occasionally due to a mutation in a DNA repair gene; much more frequently, reduced or absent expression of DNA repair genes is due to epigenetic alterations that reduce or silence gene expression. This is indicated in the figure at the 3rd level from the top. For example, for 113 colorectal cancers examined in sequence, only four had a missense mutation in the DNA repair gene MGMT, while the majority had reduced MGMT expression due to methylation of the MGMT promoter region (an epigenetic alteration).


title: Carcinogenesis

text: When expression of DNA repair genes is reduced, this causes a DNA repair deficiency. This is shown in the figure at the 4th level from the top. With a DNA repair deficiency, DNA damage persists in cells at a higher than typical level (5th level from the top in figure); this excess damage causes an increased frequency of mutation and/or epimutation (6th level from top of figure). Experimentally, mutation rates increase substantially in cells defective in DNA mismatch repair or in Homologous recombinational repair (HRR). Chromosomal rearrangements and aneuploidy also increase in HRR-defective cells During repair of DNA double-strand breaks, or repair of other DNA damage, incompletely-cleared repair sites can cause epigenetic gene silencing.


title: Carcinogenesis

text: The somatic mutations and epigenetic alterations caused by DNA damage and deficiencies in DNA repair accumulate in field defects. Field defects are normal-appearing tissues with multiple alterations (discussed in the section below), and are common precursors to development of the disordered and over-proliferating clone of tissue in a cancer. Such field defects (second level from bottom of figure) may have numerous mutations and epigenetic alterations.


title: Carcinogenesis

text: It is impossible to determine the initial cause for most specific cancers. In a few cases, only one cause exists: for example, the virus HHV-8 causes all Kaposi's sarcomas. However, with the help of cancer epidemiology techniques and information, it is possible to produce an estimate of a likely cause in many more situations. For example, lung cancer has several causes, including tobacco use and radon gas. Men who currently smoke tobacco develop lung cancer at a rate 14 times that of men who have never smoked tobacco: the chance of lung cancer in a current smoker being caused by smoking is about 93%; there is a 7% chance that the smoker's lung cancer was caused by radon gas or some other, non-tobacco cause. These statistical correlations have made it possible for researchers to infer that certain substances or behaviors are carcinogenic. Tobacco smoke causes increased exogenous DNA damage, and this DNA damage is the likely cause of lung cancer due to smoking. Among the more than 5,000 compounds in tobacco smoke, the genotoxic DNA-damaging agents that occur both at the highest concentrations, and which have the strongest mutagenic effects are acrolein, formaldehyde, acrylonitrile, 1,3-butadiene, acetaldehyde, ethylene oxide and isoprene.


title: Carcinogenesis

text: Using molecular biological techniques, it is possible to characterize the mutations, epimutations or chromosomal aberrations within a tumor, and rapid progress is being made in the field of predicting certain cancer patients' prognosis based on the spectrum of mutations. For example, up to half of all tumors have a defective p53 gene. This mutation is associated with poor prognosis, since those tumor cells are less likely to go into apoptosis or programmed cell death when damaged by therapy. Telomerase mutations remove additional barriers, extending the number of times a cell can divide. Other mutations enable the tumor to grow new blood vessels to provide more nutrients, or to metastasize, spreading to other parts of the body. However, once a cancer is formed it continues to evolve and to produce sub-clones. It was reported in 2012 that a single renal cancer specimen, sampled in nine different areas, had 40 "ubiquitous" mutations, found in all nine areas, 59 mutations shared by some, but not all nine areas, and 29 "private" mutations only present in one area.


title: Carcinogenesis

text: The lineages of cells in which all these DNA alterations accumulate are difficult to trace, but two recent lines of evidence suggest that normal stem cells may be the cells of origin in cancers. First, there exists a highly positive correlation (Spearman's rho = 0.81; P < 3.5 × 10−8) between the risk of developing cancer in a tissue and the number of normal stem cell divisions taking place in that same tissue. The correlation applied to 31 cancer types and extended across five orders of magnitude. This correlation means that if normal stem cells from a tissue divide once, the cancer risk in that tissue is approximately 1X. If they divide 1,000 times, the cancer risk is 1,000X. And if the normal stem cells from a tissue divide 100,000 times, the cancer risk in that tissue is approximately 100,000X. This strongly suggests that the main factor in cancer initiation is the fact that "normal" stem cells divide, which implies that cancer originates in normal, healthy stem cells.


title: Carcinogenesis

text: Second, statistics show that most human cancers are diagnosed in older people. A possible explanation is that cancers occur because cells accumulate damage through time. DNA is the only cellular component that can accumulate damage over the entire course of a life, and stem cells are the only cells that can transmit DNA from the zygote to cells late in life. Other cells, derived from stem cells, do not keep DNA from the beginning of life until a possible cancer occurs. This implies that most cancers arise from normal stem cells.


title: Carcinogenesis

text: The term "field cancerization" was first used in 1953 to describe an area or "field" of epithelium that has been preconditioned by (at that time) largely unknown processes so as to predispose it towards development of cancer. Since then, the terms "field cancerization" and "field defect" have been used to describe pre-malignant tissue in which new cancers are likely to arise.


title: Carcinogenesis

text: Field defects have been identified in association with cancers and are important in progression to cancer. However, it was pointed out by Rubin that "the vast majority of studies in cancer research has been done on well-defined tumors in vivo, or on discrete neoplastic foci in vitro. Yet there is evidence that more than 80% of the somatic mutations found in mutator phenotype human colorectal tumors occur before the onset of terminal clonal expansion…" More than half of somatic mutations identified in tumors occurred in a pre-neoplastic phase (in a field defect), during growth of apparently normal cells. It would also be expected that many of the epigenetic alterations present in tumors may have occurred in pre-neoplastic field defects.


title: Carcinogenesis

text: In the colon, a field defect probably arises by natural selection of a mutant or epigenetically altered cell among the stem cells at the base of one of the intestinal crypts on the inside surface of the colon. A mutant or epigenetically altered stem cell may replace the other nearby stem cells by natural selection. This may cause a patch of abnormal tissue to arise. The figure in this section includes a photo of a freshly resected and lengthwise-opened segment of the colon showing a colon cancer and four polyps. Below the photo there is a schematic diagram of how a large patch of mutant or epigenetically altered cells may have formed, shown by the large area in yellow in the diagram. Within this first large patch in the diagram (a large clone of cells), a second such mutation or epigenetic alteration may occur, so that a given stem cell acquires an advantage compared to its neighbors, and this altered stem cell may expand clonally, forming a secondary patch, or sub-clone, within the original patch. This is indicated in the diagram by four smaller patches of different colors within the large yellow original area. Within these new patches (sub-clones), the process may be repeated multiple times, indicated by the still smaller patches within the four secondary patches (with still different colors in the diagram) which clonally expand, until stem cells arise that generate either small polyps or else a malignant neoplasm (cancer). In the photo, an apparent field defect in this segment of a colon has generated four polyps (labeled with the size of the polyps, 6mm, 5mm, and two of 3mm, and a cancer about 3 cm across in its longest dimension). These neoplasms are also indicated (in the diagram below the photo) by 4 small tan circles (polyps) and a larger red area (cancer). The cancer in the photo occurred in the cecal area of the colon, where the colon joins the small intestine (labeled) and where the appendix occurs (labeled). The fat in the photo is external to the outer wall of the colon. In the segment of colon shown here, the colon was cut open lengthwise to expose its inner surface and to display the cancer and polyps occurring within the inner epithelial lining of the colon.


title: Carcinogenesis

text: If the general process by which sporadic colon cancers arise is the formation of a pre-neoplastic clone that spreads by natural selection, followed by formation of internal sub-clones within the initial clone, and sub-sub-clones inside those, then colon cancers generally should be associated with, and be preceded by, fields of increasing abnormality, reflecting the succession of premalignant events. The most extensive region of abnormality (the outermost yellow irregular area in the diagram) would reflect the earliest event in formation of a malignant neoplasm.


title: Carcinogenesis

text: In experimental evaluation of specific DNA repair deficiencies in cancers, many specific DNA repair deficiencies were also shown to occur in the field defects surrounding those cancers. The table below gives examples for which the DNA repair deficiency in a cancer was shown to be caused by an epigenetic alteration, and the somewhat lower frequencies with which the same epigenetically caused DNA repair deficiency was found in the surrounding field defect.


title: Carcinogenesis

text: Some of the small polyps in the field defect shown in the photo of the opened colon segment may be relatively benign neoplasms. In a 1996 study of polyps less than 10mm in size found during colonoscopy and followed with repeat colonoscopies for 3 years, 25% remained unchanged in size, 35% regressed or shrank in size and 40% grew in size.


title: Carcinogenesis

text: Cancers are known to exhibit genome instability or a "mutator phenotype". The protein-coding DNA within the nucleus is about 1.5% of the total genomic DNA. Within this protein-coding DNA (called the exome), an average cancer of the breast or colon can have about 60 to 70 protein altering mutations, of which about 3 or 4 may be "driver" mutations, and the remaining ones may be "passenger" mutations. However, the average number of DNA sequence mutations in the entire genome (including non-protein-coding regions) within a breast cancer tissue sample is about 20,000. In an average melanoma tissue sample (melanomas have a higher exome mutation frequency),) the total number of DNA sequence mutations is about 80,000. These high frequencies of mutations in the total nucleotide sequences within cancers suggest that often an early alteration in the field defect giving rise to a cancer (e.g. yellow area in the diagram in the preceding section) is a deficiency in DNA repair. Large field defects surrounding colon cancers (extending to about 10 cm on each side of a cancer) are found to frequently have epigenetic defects in two or three DNA repair proteins (ERCC1, ERCC4 (XPF) and/or PMS2) in the entire area of the field defect. When expression of DNA repair genes is reduced, DNA damage accumulates in cells at a higher than normal rate, and this excess damage causes an increased frequency of mutation and/or epimutation. Mutation rates strongly increase in cells defective in DNA mismatch repair or in homologous recombinational repair (HRR). A deficiency in DNA repair, itself, can allow DNA damage to accumulate, and error-prone translesion synthesis of some of the damaged areas may give rise to mutations. In addition, faulty repair of this accumulated DNA damage may give rise to epimutations. These new mutations and/or epimutations may provide a proliferative advantage, generating a field defect. Although the mutations/epimutations in DNA repair genes do not, themselves, confer a selective advantage, they may be carried along as passengers in cells when the cell acquires an additional mutation/epimutation that does provide a proliferative advantage.


title: Carcinogenesis

text: There are a number of theories of carcinogenesis and cancer treatment that fall outside the mainstream of scientific opinion, due to lack of scientific rationale, logic, or evidence base. These theories may be used to justify various alternative cancer treatments. They should be distinguished from those theories of carcinogenesis that have a logical basis within mainstream cancer biology, and from which conventionally testable hypotheses can be made.


title: Carcinogenesis

text: Several alternative theories of carcinogenesis, however, are based on scientific evidence and are increasingly being acknowledged. Some researchers believe that cancer may be caused by aneuploidy (numerical and structural abnormalities in chromosomes) rather than by mutations or epimutations. Cancer has also been considered as a metabolic disease, in which the cellular metabolism of oxygen is diverted from the pathway that generates energy (oxidative phosphorylation) to the pathway that generates reactive oxygen species. This causes an energy switch from oxidative phosphorylation to aerobic glycolysis (Warburg's hypothesis), and the accumulation of reactive oxygen species leading to oxidative stress ("oxidative stress theory of cancer"). Another concept of cancer development is based on exposure to weak magnetic and electromagnetic fields and their effects on oxidative stress, known as magnetocarcinogenesis.


title: Carcinogenesis

text: A number of authors have questioned the assumption that cancers result from sequential random mutations as oversimplistic, suggesting instead that cancer results from a failure of the body to inhibit an innate, programmed proliferative tendency. A related theory suggests that cancer is an atavism, an evolutionary throwback to an earlier form of multicellular life. The genes responsible for uncontrolled cell growth and cooperation between cancer cells are very similar to those that enabled the first multicellular life forms to group together and flourish. These genes still exist within the genomes of more complex metazoans, such as humans, although more recently evolved genes keep them in check. When the newer controlling genes fail for whatever reason, the cell can revert to its more primitive programming and reproduce out of control. The theory is an alternative to the notion that cancers begin with rogue cells that undergo evolution within the body. Instead, they possess a fixed number of primitive genes that are progressively activated, giving them finite variability. Another evolutionary theory puts the roots of cancer back to the origin of the eukaryote (nucleated) cell by massive horizontal gene transfer, when the genomes of infecting viruses were cleaved (and thereby attenuated) by the host, but their fragments integrated into the host genome as immune protection. Cancer thus originates when a rare somatic mutation recombines such fragments into a functional driver of cell proliferation.


title: Carcinogenesis

text: Often, the multiple genetic changes that result in cancer may take many years to accumulate. During this time, the biological behavior of the pre-malignant cells slowly changes from the properties of normal cells to cancer-like properties. Pre-malignant tissue can have a distinctive appearance under the microscope. Among the distinguishing traits of a pre-malignant lesion are an increased number of dividing cells, variation in nuclear size and shape, variation in cell size and shape, loss of specialized cell features, and loss of normal tissue organization. Dysplasia is an abnormal type of excessive cell proliferation characterized by loss of normal tissue arrangement and cell structure in pre-malignant cells. These early neoplastic changes must be distinguished from hyperplasia, a reversible increase in cell division caused by an external stimulus, such as a hormonal imbalance or chronic irritation.


title: Carcinogenesis

text: The most severe cases of dysplasia are referred to as "carcinoma in situ." In Latin, the term "in situ" means "in place"; "carcinoma in situ" refers to an uncontrolled growth of dysplastic cells that remains in its original location and has not shown invasion into other tissues. Carcinoma in situ may develop into an invasive malignancy and is usually removed surgically when detected.


title: Carcinogenesis

text: Just as a population of animals undergoes evolution, an unchecked population of cells also can undergo "evolution". This undesirable process is called somatic evolution, and is how cancer arises and becomes more malignant over time.


title: Carcinogenesis

text: Most changes in cellular metabolism that allow cells to grow in a disorderly fashion lead to cell death. However, once cancer begins, cancer cells undergo a process of natural selection: the few cells with new genetic changes that enhance their survival or reproduction multiply faster, and soon come to dominate the growing tumor as cells with less favorable genetic change are out-competed. This is the same mechanism by which pathogenic species such as MRSA can become antibiotic-resistant and by which HIV can become drug-resistant), and by which plant diseases and insects can become pesticide-resistant. This evolution explains why a cancer relapse often involves cells that have acquired cancer-drug resistance or resistance to radiotherapy).


title: Carcinogenesis

text: In a 2000 article by Hanahan and Weinberg, the biological properties of malignant tumor cells were summarized as follows:


title: Carcinogenesis

text: These biological changes are classical in carcinomas; other malignant tumors may not need to achieve them all. For example, given that tissue invasion and displacement to distant sites are normal properties of leukocytes, these steps are not needed in the development of leukemia. Nor do the different steps necessarily represent individual mutations. For example, inactivation of a single gene, coding for the p53 protein, will cause genomic instability, evasion of apoptosis and increased angiogenesis. Further, not all the cancer cells are dividing. Rather, a subset of the cells in a tumor, called cancer stem cells, replicate themselves as they generate differentiated cells.


title: Carcinogenesis

text: Normally, once a tissue is injured or infected, damaged cells elicit inflammation by stimulating specific patterns of enzyme activity and cytokine gene expression in surrounding cells. Discrete clusters ("cytokine clusters") of molecules are secreted, which act as mediators, inducing the activity of subsequent cascades of biochemical changes. Each cytokine binds to specific receptors on various cell types, and each cell type responds in turn by altering the activity of intracellular signal transduction pathways, depending on the receptors that the cell expresses and the signaling molecules present inside the cell. Collectively, this reprogramming process induces a stepwise change in cell phenotypes, which will ultimately lead to restoration of tissue function and toward regaining essential structural integrity. A tissue can thereby heal, depending on the productive communication between the cells present at the site of damage and the immune system. One key factor in healing is the regulation of cytokine gene expression, which enables complementary groups of cells to respond to inflammatory mediators in a manner that gradually produces essential changes in tissue physiology. Cancer cells have either permanent (genetic) or reversible (epigenetic) changes to their genome, which partly inhibit their communication with surrounding cells and with the immune system. Cancer cells do not communicate with their tissue microenvironment in a manner that protects tissue integrity; instead, the movement and the survival of cancer cells become possible in locations where they can impair tissue function. Cancer cells survive by "rewiring" signal pathways that normally protect the tissue from the immune system. This alteration of the immune response is evident in early stages of malignancy too.


title: Carcinogenesis

text: NF-κB activates the expression of numerous genes involved in the transition between inflammation and regeneration, which encode cytokines, adhesion factors, and other molecules that can change cell fate. This reprogramming of cellular phenotypes normally allows the development of a fully functional intact tissue. NF-κB activity is tightly controlled by multiple proteins, which collectively ensure that only discrete clusters of genes are induced by NF-κB in a given cell and at a given time. This tight regulation of signal exchange between cells protects the tissue from excessive inflammation, and ensures that different cell types gradually acquire complementary functions and specific positions. Failure of this mutual regulation between genetic reprogramming and cell interactions allows cancer cells to give rise to metastasis. Cancer cells respond aberrantly to cytokines, and activate signal cascades that can protect them from the immune system.


title: Carcinogenesis

text: The role of iodine in marine fish (rich in iodine) and freshwater fish (iodine-deficient) is not completely understood, but it has been reported that freshwater fish are more susceptible to infectious and, in particular, neoplastic and atherosclerotic diseases, than marine fish. Marine elasmobranch fishes such as sharks, stingrays etc. are much less affected by cancer than freshwater fishes, and therefore have stimulated medical research to better understand carcinogenesis.


title: Carcinogenesis

text: In order for cells to start dividing uncontrollably, genes that regulate cell growth must be dysregulated. Proto-oncogenes are genes that promote cell growth and mitosis, whereas tumor suppressor genes discourage cell growth, or temporarily halt cell division to carry out DNA repair. Typically, a series of several mutations to these genes is required before a normal cell transforms into a cancer cell. This concept is sometimes termed "oncoevolution." Mutations to these genes provide the signals for tumor cells to start dividing uncontrollably. But the uncontrolled cell division that characterizes cancer also requires that the dividing cell duplicates all its cellular components to create two daughter cells. The activation of anaerobic glycolysis (the Warburg effect), which is not necessarily induced by mutations in proto-oncogenes and tumor suppressor genes, provides most of the building blocks required to duplicate the cellular components of a dividing cell and, therefore, is also essential for carcinogenesis.


title: Carcinogenesis

text: Oncogenes promote cell growth through a variety of ways. Many can produce hormones, a "chemical messenger" between cells that encourage mitosis, the effect of which depends on the signal transduction of the receiving tissue or cells. In other words, when a hormone receptor on a recipient cell is stimulated, the signal is conducted from the surface of the cell to the cell nucleus to affect some change in gene transcription regulation at the nuclear level. Some oncogenes are part of the signal transduction system itself, or the signal receptors in cells and tissues themselves, thus controlling the sensitivity to such hormones. Oncogenes often produce mitogens, or are involved in transcription of DNA in protein synthesis, which creates the proteins and enzymes responsible for producing the products and biochemicals cells use and interact with.


title: Carcinogenesis

text: Mutations in proto-oncogenes, which are the normally quiescent counterparts of oncogenes, can modify their expression and function, increasing the amount or activity of the product protein. When this happens, the proto-oncogenes become oncogenes, and this transition upsets the normal balance of cell cycle regulation in the cell, making uncontrolled growth possible. The chance of cancer cannot be reduced by removing proto-oncogenes from the genome, even if this were possible, as they are critical for growth, repair and homeostasis of the organism. It is only when they become mutated that the signals for growth become excessive.


title: Carcinogenesis

text: One of the first oncogenes to be defined in cancer research is the ras oncogene. Mutations in the Ras family of proto-oncogenes (comprising H-Ras, N-Ras and K-Ras) are very common, being found in 20% to 30% of all human tumours. Ras was originally identified in the Harvey sarcoma virus genome, and researchers were surprised that not only is this gene present in the human genome but also, when ligated to a stimulating control element, it could induce cancers in cell line cultures.


title: Carcinogenesis

text: Proto-oncogenes promote cell growth in a variety of ways. Many can produce hormones, "chemical messengers" between cells that encourage mitosis, the effect of which depends on the signal transduction of the receiving tissue or cells. Some are responsible for the signal transduction system and signal receptors in cells and tissues themselves, thus controlling the sensitivity to such hormones. They often produce mitogens, or are involved in transcription of DNA in protein synthesis, which create the proteins and enzymes responsible for producing the products and biochemicals cells use and interact with.


title: Carcinogenesis

text: Mutations in proto-oncogenes can modify their expression and function, increasing the amount or activity of the product protein. When this happens, they become oncogenes, and, thus, cells have a higher chance of dividing excessively and uncontrollably. The chance of cancer cannot be reduced by removing proto-oncogenes from the genome, as they are critical for growth, repair and homeostasis of the body. It is only when they become mutated that the signals for growth become excessive.


title: Carcinogenesis

text: It is important to note that a gene possessing a growth-promoting role may increase the carcinogenic potential of a cell, under the condition that all necessary cellular mechanisms that permit growth are activated. This condition also includes the inactivation of specific tumor suppressor genes (see below). If the condition is not fulfilled, the cell may cease to grow and can proceed to die. This makes identification of the stage and type of cancer cell that grows under the control of a given oncogene crucial for the development of treatment strategies.


title: Carcinogenesis

text: Tumor suppressor genes code for anti-proliferation signals and proteins that suppress mitosis and cell growth. Generally, tumor suppressors are transcription factors that are activated by cellular stress or DNA damage. Often DNA damage will cause the presence of free-floating genetic material as well as other signs, and will trigger enzymes and pathways that lead to the activation of tumor suppressor genes. The functions of such genes is to arrest the progression of the cell cycle in order to carry out DNA repair, preventing mutations from being passed on to daughter cells. The p53 protein, one of the most important studied tumor suppressor genes, is a transcription factor activated by many cellular stressors including hypoxia and ultraviolet radiation damage.


title: Carcinogenesis

text: Despite nearly half of all cancers possibly involving alterations in p53, its tumor suppressor function is poorly understood. p53 clearly has two functions: one a nuclear role as a transcription factor, and the other a cytoplasmic role in regulating the cell cycle, cell division, and apoptosis.


title: Carcinogenesis

text: The Warburg hypothesis is the preferential use of glycolysis for energy to sustain cancer growth. p53 has been shown to regulate the shift from the respiratory to the glycolytic pathway.


title: Carcinogenesis

text: However, a mutation can damage the tumor suppressor gene itself, or the signal pathway that activates it, "switching it off". The invariable consequence of this is that DNA repair is hindered or inhibited: DNA damage accumulates without repair, inevitably leading to cancer.


title: Carcinogenesis

text: Mutations of tumor suppressor genes that occur in germline cells are passed along to offspring, and increase the likelihood for cancer diagnoses in subsequent generations. Members of these families have increased incidence and decreased latency of multiple tumors. The tumor types are typical for each type of tumor suppressor gene mutation, with some mutations causing particular cancers, and other mutations causing others. The mode of inheritance of mutant tumor suppressors is that an affected member inherits a defective copy from one parent, and a normal copy from the other. For instance, individuals who inherit one mutant "p53" allele (and are therefore heterozygous for mutated "p53") can develop melanomas and pancreatic cancer, known as Li-Fraumeni syndrome. Other inherited tumor suppressor gene syndromes include "Rb" mutations, linked to retinoblastoma, and "APC" gene mutations, linked to adenopolyposis colon cancer. Adenopolyposis colon cancer is associated with thousands of polyps in colon while young, leading to colon cancer at a relatively early age. Finally, inherited mutations in "BRCA1" and "BRCA2" lead to early onset of breast cancer.


title: Carcinogenesis

text: Development of cancer was proposed in 1971 to depend on at least two mutational events. In what became known as the Knudson two-hit hypothesis, an inherited, germ-line mutation in a tumor suppressor gene would cause cancer only if another mutation event occurred later in the organism's life, inactivating the other allele of that tumor suppressor gene.


title: Carcinogenesis

text: Usually, oncogenes are dominant, as they contain gain-of-function mutations, while mutated tumor suppressors are recessive, as they contain loss-of-function mutations. Each cell has two copies of the same gene, one from each parent, and under most cases gain of function mutations in just one copy of a particular proto-oncogene is enough to make that gene a true oncogene. On the other hand, loss of function mutations need to happen in both copies of a tumor suppressor gene to render that gene completely non-functional. However, cases exist in which one mutated copy of a tumor suppressor gene can render the other, wild-type copy non-functional. This phenomenon is called the "dominant negative effect" and is observed in many p53 mutations.


title: Carcinogenesis

text: Knudson's two hit model has recently been challenged by several investigators. Inactivation of one allele of some tumor suppressor genes is sufficient to cause tumors. This phenomenon is called haploinsufficiency and has been demonstrated by a number of experimental approaches. Tumors caused by haploinsufficiency usually have a later age of onset when compared with those by a two hit process.


title: Carcinogenesis

text: In general, mutations in both types of genes are required for cancer to occur. For example, a mutation limited to one oncogene would be suppressed by normal mitosis control and tumor suppressor genes, first hypothesised by the Knudson hypothesis. A mutation to only one tumor suppressor gene would not cause cancer either, due to the presence of many "backup" genes that duplicate its functions. It is only when enough proto-oncogenes have mutated into oncogenes, and enough tumor suppressor genes deactivated or damaged, that the signals for cell growth overwhelm the signals to regulate it, that cell growth quickly spirals out of control. Often, because these genes regulate the processes that prevent most damage to genes themselves, the rate of mutations increases as one gets older, because DNA damage forms a feedback loop.


title: Carcinogenesis

text: Mutation of tumor suppressor genes that are passed on to the next generation of not merely cells, but their offspring, can cause increased likelihoods for cancers to be inherited. Members within these families have increased incidence and decreased latency of multiple tumors. The mode of inheritance of mutant tumor suppressors is that affected member inherits a defective copy from one parent, and a normal copy from another. Because mutations in tumor suppressors act in a recessive manner (note, however, there are exceptions), the loss of the normal copy creates the cancer phenotype. For instance, individuals that are heterozygous for p53 mutations are often victims of Li-Fraumeni syndrome, and that are heterozygous for Rb mutations develop retinoblastoma. In similar fashion, mutations in the adenomatous polyposis coli gene are linked to adenopolyposis colon cancer, with thousands of polyps in the colon while young, whereas mutations in BRCA1 and BRCA2 lead to early onset of breast cancer.


title: Carcinogenesis

text: A new idea announced in 2011 is an extreme version of multiple mutations, called "chromothripsis" by its proponents. This idea, affecting only 2–3% of cases of cancer, although up to 25% of bone cancers, involves the catastrophic shattering of a chromosome into tens or hundreds of pieces and then being patched back together incorrectly. This shattering probably takes place when the chromosomes are compacted during normal cell division, but the trigger for the shattering is unknown. Under this model, cancer arises as the result of a single, isolated event, rather than the slow accumulation of multiple mutations.


title: Carcinogenesis

text: Many mutagens are also carcinogens, but some carcinogens are not mutagens. Examples of carcinogens that are not mutagens include alcohol and estrogen. These are thought to promote cancers through their stimulating effect on the rate of cell mitosis. Faster rates of mitosis increasingly leave fewer opportunities for repair enzymes to repair damaged DNA during DNA replication, increasing the likelihood of a genetic mistake. A mistake made during mitosis can lead to the daughter cells' receiving the wrong number of chromosomes, which leads to aneuploidy and may lead to cancer.


title: Carcinogenesis

text: "Helicobacter pylori" can cause gastric cancer. Although the data varies between different countries, overall about 1% to 3% of people infected with "Helicobacter pylori" develop gastric cancer in their lifetime compared to 0.13% of individuals who have had no "H. pylori" infection. "H. pylori" infection is very prevalent. As evaluated in 2002, it is present in the gastric tissues of 74% of middle-aged adults in developing countries and 58% in developed countries. Since 1% to 3% of infected individuals are likely to develop gastric cancer, "H. pylori"-induced gastric cancer is the third highest cause of worldwide cancer mortality as of 2018.


title: Carcinogenesis

text: Infection by "H. pylori" causes no symptoms in about 80% of those infected. About 75% of individuals infected with "H. pylori" develop gastritis. Thus, the usual consequence of "H. pylori" infection is chronic asymptomatic gastritis. Because of the usual lack of symptoms, when gastric cancer is finally diagnosed it is often fairly advanced. More than half of gastric cancer patients have lymph node metastasis when they are initially diagnosed.


title: Carcinogenesis

text: The gastritis caused by "H. pylori" is accompanied by inflammation, characterized by infiltration of neutrophils and macrophages to the gastric epithelium, which favors the accumulation of pro-inflammatory cytokines and reactive oxygen species/reactive nitrogen species (ROS/RNS). The substantial presence of ROS/RNS causes DNA damage including 8-oxo-2'-deoxyguanosine (8-OHdG). If the infecting "H. pylori" carry the cytotoxic cagA gene (present in about 60% of Western isolates and a higher percentage of Asian isolates), they can increase the level of 8-OHdG in gastric cells by 8-fold, while if the "H. pylori" do not carry the cagA gene, the increase in 8-OHdG is about 4-fold. In addition to the oxidative DNA damage 8-OHdG, "H. pylori" infection causes other characteristic DNA damages including DNA double-strand breaks.


title: Carcinogenesis

text: "H. pylori" also causes many epigenetic alterations linked to cancer development. These epigenetic alterations are due to "H. pylori"-induced methylation of CpG sites in promoters of genes and "H. pylori"-induced altered expression of multiple microRNAs.


title: Carcinogenesis

text: As reviewed by Santos and Ribeiro "H. pylori" infection is associated with epigenetically reduced efficiency of the DNA repair machinery, which favors the accumulation of mutations and genomic instability as well as gastric carcinogenesis. In particular, Raza et al. showed that expression of two DNA repair proteins, ERCC1 and PMS2, was severely reduced once "H. pylori" infection had progressed to cause dyspepsia. Dyspepsia occurs in about 20% of infected individuals. In addition, as reviewed by Raza et al., human gastric infection with "H. pylori" causes epigenetically reduced protein expression of DNA repair proteins MLH1, MGMT and MRE11. Reduced DNA repair in the presence of increased DNA damage increases carcinogenic mutations and is likely a significant cause of "H. pylori" carcinogenesis.


title: Carcinogenesis

text: Furthermore, many cancers originate from a viral infection; this is especially true in animals such as birds, but less so in humans. 12% of human cancers can be attributed to a viral infection. The mode of virally induced tumors can be divided into two, "acutely transforming" or "slowly transforming". In acutely transforming viruses, the viral particles carry a gene that encodes for an overactive oncogene called viral-oncogene (v-onc), and the infected cell is transformed as soon as v-onc is expressed. In contrast, in slowly transforming viruses, the virus genome is inserted, especially as viral genome insertion is an obligatory part of retroviruses, near a proto-oncogene in the host genome. The viral promoter or other transcription regulation elements, in turn, cause over-expression of that proto-oncogene, which, in turn, induces uncontrolled cellular proliferation. Because viral genome insertion is not specific to proto-oncogenes and the chance of insertion near that proto-oncogene is low, slowly transforming viruses have very long tumor latency compared to acutely transforming virus, which already carries the viral-oncogene.


title: Carcinogenesis

text: Viruses that are known to cause cancer such as HPV (cervical cancer), Hepatitis B (liver cancer), and EBV (a type of lymphoma), are all DNA viruses. It is thought that when the virus infects a cell, it inserts a part of its own DNA near the cell growth genes, causing cell division. The group of changed cells that are formed from the first cell dividing all have the same viral DNA near the cell growth genes. The group of changed cells are now special because one of the normal controls on growth has been lost.


title: Carcinogenesis

text: Depending on their location, cells can be damaged through radiation, chemicals from cigarette smoke, and inflammation from bacterial infection or other viruses. Each cell has a chance of damage. Cells often die if they are damaged, through failure of a vital process or the immune system, however, sometimes damage will knock out a single cancer gene. In an old person, there are thousands, tens of thousands, or hundreds of thousands of knocked-out cells. The chance that any one would form a cancer is very low.


title: Carcinogenesis

text: When the damage occurs in any area of changed cells, something different occurs. Each of the cells has the potential for growth. The changed cells will divide quicker when the area is damaged by physical, chemical, or viral agents. A vicious circle has been set up: Damaging the area will cause the changed cells to divide, causing a greater likelihood that they will experience knock-outs.


title: Carcinogenesis

text: This model of carcinogenesis is popular because it explains why cancers grow. It would be expected that cells that are damaged through radiation would die or at least be worse off because they have fewer genes working; viruses increase the number of genes working.