bluuebunny/crossref_metadata_2025 huggingface dataset:
Why do People get Tattoos?
Authors: Kang Miliann , Jones Katherine
Published: February 2007

As increasingly diverse groups of people get tattoos, popular perceptions are often out of synch with the individual meanings behind them.
The PROGINS polymorphism of the human progesterone receptor diminishes the response to progesterone
Authors: Romano Andrea , Delvoux Bert , Fischer Dagmar-Christiane , Groothuis Patrick
Published: February 2007

The human progesterone receptor (PR) is a ligand-dependent transcription factor and two isoforms, (PRA and PRB), can be distinguished. PROGINS, a PR polymorphic variant, affects PRA and PRB and acts as a risk-modulating factor in several gynaecological disorders. Little is known about the functional consequences of this variant. Here, we characterise the properties of PROGINS with respect to transcription, mRNA maturation, protein activity and proliferation. PROGINS is characterised by a 320 bp PV/HS-1 Alu insertion in intron G and two point mutations, V660L in exon 4 and H770H (silent substitution) in exon 5. The Alu element contains a half oestrogen-response element/Sp1-binding site (Alu-ERE/Sp1), which acts as an in-cis intronic enhancer leading to increased transcription of the PROGINS allele in response to 17β-oestradiol. Moreover, Alu insertions in the human genome are frequently methylated. Our data indicate that the PROGINS-Alu does not affect gene transcription due to DNA methylation. However, the Alu element reduced the stability of the PROGINS transcript compared with the CP allele and does not generate splice variants. The amino acid substitution (V600L) in exon 4 leads to differences in PR phosphorylation and degradation in the two PR variants upon ligand binding, most likely as a result of differences in the three-dimensional structures of the two PR variants. As a consequence, the PR-L660 (PROGINS) variant (1) displays decreased transactivation activity in a luciferase reporter system and (2) is less efficient in opposing cell proliferation in hamster ovarian cells expressing human PRA, when compared with the PR-V660 (most common variant). Taken together, our results indicate that the PROGINS variant of PR is less responsive to progestin compared with the most common PR because of (i) reduced amounts of gene transcript and (ii) decreased protein activity.
Euthanasia and the Administration of Neuromuscular Blockers without Ventilation: Should Physicians Fear Prosecution?
Authors: Ziegler Stephen J.
Published: February 2007

A common dilemma among physicians who treat the dying is whether pharmacological paralysis should be reversed prior to removal of mechanical ventilation. But what if a physician were to administer a neuromuscular blocker without ever ventilating the patient in the first place? While there is evidence that euthanasia does occur in the United States, few physicians have been prosecuted. Could these infrequent prosecutions reflect a conscious desire by prosecutors not to pursue such matters? In an effort to explore this question, chief prosecutors in four U.S. states were presented with a vignette based on an actual event involving the administration of Succinylcholine to a dying patient. Response rates in this study were very acceptable (76.36% overall), and results indicated that not only was the likelihood of criminal prosecution low, almost half of the prosecutors believed that a physicianadministered lethal injection may be morally justified in some circumstances even though illegal.
The Dance of Closeness-Distance in Couple Relationships after the Death of a Parent
Authors: Rosenblatt Paul C. , Barner John R.
Published: February 2007

In-depth interviews of 18 couples focused on the couple relationship after a partner experienced the death of a parent. Working from a view of couple relationships as involving a dance of closeness and distance, never getting too far apart or coming too close, the article explores how a parent's death can alter the conditions, forms, and grounds of closeness-distance and how issues of support following the death are entangled in the dance. As they grieve, bereaved partners might want closeness at some times, distance at others, and might welcome or reject offered support. A parent death may be freeing in terms of time or emotion and may profoundly effect thoughts about the meaning of life. The dance of closeness-distance may change if people feel freed by the death and work with new life meanings. Closeness-distance is also affected by how partners feel about what they shared or did not share as a result of the loss. Further complicating the dance are the effects of practical issues that may arise following a parent death, including dealing with a surviving parent and with the estate of the deceased.
A Pilot Study of the Development of a Tool to Measure Instrumental and Intuitive Styles of Grieving
Authors: Martin Terry L. , Wang Wen-Chi
Published: February 2007

Recently, 2 patterns of grieving (intuitive and instrumental) were identified as 2 extremes on a continuum. One of these patterns (instrumental) challenged the grief work hypothesis and traditional views of grieving. This study sought to validate an instrument to identify these 2 patterns. Sixty-three volunteer participants were randomly assigned to two groups, each receiving both the Grief Experience Inventory and the Grief Pattern Inventory. It was hypothesized that: 1) the Grief Pattern Inventory would determine the intuitive and instrument patterns of grief; and 2) these 2 patterns would be correlated with the subscales on Grief Experience Inventory to further highlight the differences between the 2 patterns. The analyzed results were found to support both of the hypotheses.
Heritability and clinical features of multigenerational families with obsessive‐compulsive disorder and hoarding
Authors: Mathews Carol A. , Nievergelt Caroline M. , Azzam Amin , Garrido Helena , Chavira Denise A. , Wessel Jennifer , Bagnarello Monica , Reus Victor I. , Schork Nicholas J.
Published: February 2007

To date, only one complete genome screen for obsessive‐compulsive disorder (OCD) has been published. That study identified a region of suggestive linkage (maximum lod score of 2.25) with a relatively small sample size (N = 56; 27 with OCD). Additional complete genome screens are needed to confirm this finding and identify other regions of linkage. We present the clinical characteristics and power to detect linkage of 11 multigenerational families with OCD and hoarding (N = 92; 44 with OCD), as well as heritability estimates for several quantitative traits. Families with at least two individuals with OCD were identified through probands with childhood‐onset OCD. Expected lod scores were calculated for simulated genetic marker data under an additive and two dominant models assuming a dense SNP marker map. All affected individuals had an early age of onset (18 or younger). Hoarding was present in 46% of subjects. Obsessive‐compulsive symptoms and hoarding were highly heritable. The maximum mean expected lod score was 3.31 for OCD and 1.39 for hoarding. We found reasonable power to detect regions of interest (lod = 2) for OCD in these families, but will need to expand our family collection to have adequate power to detect regions of interest for hoarding. © 2007 Wiley‐Liss, Inc.
Growth and developmental outcomes of three high‐risk infant rhesus macaques (Macaca mulatta)
Authors: Dettmer Amanda M. , Houser Lisa A. , Ruppenthal Gerald C. , Capuano Saverio , Hewitson Laura
Published: February 2007

Infants classified as “high risk” are born with a greater chance of developing medical complications at birth, and may have cognitive and other developmental complications later in life. Very few reports exist regarding the survival and outcome of such infants in primate colonies. Here we present early growth and developmental data on three high‐risk infant rhesus macaques (one female and two males) that were born either with intrauterine growth restriction (IUGR; born below the 1st birth weight percentile for gestational age) or extremely prematurely (at gestational days 128 and 140; mean full‐term gestation=164 days). We compared the outcome of these infants with that of healthy controls born at term and found no gross developmental delays in these infants with respect to growth, neonatal reflex and motor skill development, early cognitive development, or social behavior. Neurological and cognitive assessments were compared in terms of both postnatal and gestational age. The survival of these infants was dependent on a 24‐hr staffed nursery and a fluid protocol that catered to each high‐risk infant's individual needs. When such measures are implemented, infants such as these have a good chance of survival and can serve as excellent models for high‐risk human babies and their subsequent development. Am. J. Primatol. 69:503–518, 2007. © 2007 Wiley‐Liss, Inc.
Fruit availability, chimpanzee diet, and grouping patterns on Rubondo Island, Tanzania
Authors: Moscovice L.R. , Issa M.H. , Petrzelkova K.J. , Keuler N.S. , Snowdon C.T. , Huffman M.A.
Published: February 2007

We examined seasonal patterns of fruit availability, dietary quality, and group size in the descendants of an introduced chimpanzee population on Rubondo Island, Tanzania. The site has supported a free‐ranging population without provisioning for 40 years. Our goals were to determine whether Rubondo chimpanzees experience periods of fruit shortage, and whether they respond to changes in fruit availability similarly to chimpanzees at endemic sites. We indexed the fruit availability of tree and liana species on transects stratified across three chimpanzee ranging areas. We used fecal analyses to evaluate seasonal changes in diet, and used data on party size and nesting group size to examine seasonal patterns of grouping. Tree fruit availability was positively correlated with rainfall, with a period of relative tree fruit scarcity corresponding with the long dry season. Liana fruit availability was not related to rainfall, and lianas exhibited less variable fruiting patterns across seasons. Fruits made up the majority of the chimpanzee diet, with lianas accounting for 35% of dietary fruit species. Fruits of the liana Saba comorensis were available during all months of phenological monitoring, but they were consumed more when tree fruit was scarce, suggesting that Saba comorensis fruits may be a fallback food for Rubondo chimpanzees. There were no increases in consumption of lower‐quality plant parts between seasons, and there were no changes in group size between seasons. These results contrast with evidence from several endemic chimpanzee study sites, and indicate that Rubondo chimpanzees may have access to abundant and high‐quality foods year round. Am. J. Primatol. 69:487–502, 2007. © 2007 Wiley‐Liss, Inc.
‘Improvisational negotiation,’ leads 2007 CPR awards; Nigeria ADR group gets special award
Authors: Bleemer Russ
Published: February 2007

A rundown of the 2006 CPR Institute Awards for Excellence in ADR, given out last month at CPR's Annual Meeting in New York. Also, CPR announces a new addition to its Panels of Distinguished Neutrals
Sich durchdringende polare und unpolare Untergitter in intermetallischen Phasen: die Struktur von NaCd2
Authors: Fredrickson Daniel C. , Lee Stephen , Hoffmann Roald
Published: February 2007

In den 1960er Jahren bestimmte Samson die Strukturen einiger der komplexesten intermetallischen Phasen, darunter NaCd2, Mg2Al3und Cu3Cd4, die jeweils über 1000 Atome pro Elementarzelle aufweisen. Basierend auf den bemerkenswerten Arbeiten von Samson und Andersson verwenden wir quantenmechanische Rechnungen zur Beschreibung dieser Strukturen. Der formale Aufbau der Struktur auf der Grundlage der elektronischen Verhältnisse beginnt mit der relativ einfachen Mg17Al12‐Struktur und setzt sich bis zu Samsons NaCd2‐Struktur fort, wobei die Aufteilung in elektronenreiche und elektronenarme Gitterplätze (bezüglich der durchschnittlichen Elektronenzahl) bei beiden Strukturen das Vorliegen von Fragmenten des MgCu2‐Typs aufdeckt. Die äußeren und inneren Bereiche eines solchen Fragments weisen unterschiedliche Bindungsverhältnisse auf: Der innere Bereich ist eher polar, während die Grenzflächen relativ unpolar sind. Dieser Sachverhalt kann mit der Geometrie der Grenzflächenplätze begründet werden, die zugleich an elektronenreichen wie auch elektronenarmen Gittern beteiligt sind. Die polaren und unpolaren Gitterplätze in NaCd2sind durch eine Minimalfläche, die D‐Fläche, voneinander getrennt. Die Argumente, die für eine solche Struktur sprechen, beruhen auf elektronischen Überlegungen. Ein entscheidendes Merkmal besteht darin, dass sich polare und unpolare Bindungstypen gegenseitig durchdringen. Diese Methode lässt sich auch auf andere Strukturen anwenden.
Innentitelbild: Reduction of Phenyl Silyl Acetylenes with Lithium: Unexpected Formation of a Dilithium Dibenzopentalenide (Angew. Chem. 9/2007)
Authors: Saito Masaichi , Nakamura Michio , Tajima Tomoyuki , Yoshioka Michikazu
Published: February 2007

Die Reduktion von Phenylsilylacetylenen mit Lithium lieferte neben dem erwarteten 1,4‐Dilithio‐1,3‐butadien unerwartet auch ein Dilithiumdibenzopentalenid‐Derivat. Die Sperrigkeit des Silylsubstituenten im Phenylsilylacetylen beeinflusst den Reduktionsmodus erheblich. Weitere Einzelheiten finden Sie in der Zuschrift von M. Saito et al. auf S. 1526 ff.
Inside Cover: Reduction of Phenyl Silyl Acetylenes with Lithium: Unexpected Formation of a Dilithium Dibenzopentalenide (Angew. Chem. Int. Ed. 9/2007)
Authors: Saito Masaichi , Nakamura Michio , Tajima Tomoyuki , Yoshioka Michikazu
Published: February 2007

Reduction of phenyl silyl acetylenes with lithium led to the unexpected formation of a dilithium dibenzopentalenide derivative together with the expected 1,4‐dilithio‐1,3‐butadiene. The bulkiness of the silyl substituent of the phenyl silyl acetylene strongly affects its reduction mode. Further details may be found in the Communication by M. Saito and co‐workers on page 1504 ff.
A Large Scale Synthesis of a Natural Antibiotic, 2,4‐Diacetylophloroglucinol (DAPG)
Authors: Zakrzewski Jerzy , Karpińska Monika , Maliński Zbigniew
Published: February 2007

A natural antibiotic, 2,4‐diacetylophloroglucinol (DAPG), has been prepared by the acetylation of phloroglucinol (PhL) with acetic anhydride in the presence of boron trifluoride etherate complex. The crude DAPG is efficiently purified using chromatographic filtration with boiling eluent.
Synthesis of Molecular Wires of Linear and Branched Bis(terpyridine)‐Complex Oligomers and Electrochemical Observation of Through‐Bond Redox Conduction
Authors: Nishimori Yoshihiko , Kanaizuka Katsuhiko , Murata Masaki , Nishihara Hiroshi
Published: February 2007

Films of linear and branched oligomer wires of Fe(tpy)2 (tpy=2,2′:6′,2′′‐terpyridine) were constructed on a gold‐electrode surface by the interfacial stepwise coordination method, in which a surface‐anchoring ligand, (tpyC6H4NNC6H4S)2 (1), two bridging ligands, 1,4‐(tpy)2C6H4 (3) and 1,3,5‐(CCtpy)3C6H3 (4), and metal ions were used. The quantitative complexation of the ligands and FeII ions was monitored by electrochemical measurements in up to eight complexation cycles for linear oligomers of 3 and in up to four cycles for branched oligomers of 4. STM observation of branched oligomers at low surface coverage showed an even distribution of nanodots of uniform size and shape, which suggests the quantitative formation of dendritic structures. The electron‐transport mechanism and kinetics for the redox reaction of the films of linear and branched oligomer wires were analyzed by potential‐step chronoamperometry (PSCA). The unique current‐versus‐time behavior observed under all conditions indicates that electron conduction occurs not by diffusional motion but by successive electron hopping between neighboring redox sites within a molecular wire. Redox conduction in a single molecular wire in a redox‐polymer film has not been reported previously. The analysis provided the rate constant for electron transfer between the electrode and the nearest redox‐complex moiety, k1 (s−1), as well as that for intrawire electron transfer between neighboring redox‐complex moieties, k2 (cm2 mol−1 s−1). The strong effect of the electrolyte concentration on both k1 and k2 indicates that the counterion motion limits the electron‐hopping rate at lower electrolyte concentrations. Analysis of the dependence of k1 and k2 on the potential gave intrinsic kinetic parameters without overpotential effects: k10=110 s−1, k20=2.6×1012 cm2 mol−1 s−1 for [n Fe3], and k10=100 s−1, k20=4.1×1011 cm2 mol−1 s−1 for [n Fe4] (n=number of complexation cycles).
Trading performance, disposition effect, overconfidence, representativeness bias, and experience of emerging market investors
Authors: Chen Gongmeng , Kim Kenneth A. , Nofsinger John R. , Rui Oliver M.
Published: February 2007

Using brokerage account data from China, we study investment decision making in an emerging market. We find that Chinese investors make poor trading decisions: the stocks they purchase underperform those they sell. We also find that Chinese investors suffer from three behavioral biases: (i) they tend to sell stocks that have appreciated in price, but not those that have depreciated in price, consistent with a disposition effect, acknowledging gains but not losses; (ii) they seem overconfident; and (iii) they appear to believe that past returns are indicative of future returns (a representativeness bias). In comparisons to prior findings, Chinese investors seem more overconfident than U.S. investors (i.e., the Chinese hold fewer stocks, yet trade very often) and their disposition effect appears stronger. Finally, we categorize Chinese investors based on proxy measures of experience and find that “experienced” investors are not always less prone to behavioral biases than are “inexperienced” ones. Copyright © 2007 John Wiley & Sons, Ltd.
Maternal plasma pyridoxal‐5′‐phosphate concentrations and risk of isolated oral clefts in the Philippines
Authors: Tamura Tsunenobu , Munger Ronald G. , Nepomuceno Buena , Corcoran Christopher , Cembrano Joselito , Solon Florentino
Published: February 2007

BACKGROUND:

We report that inadequate vitamin B‐6 status of Filipino mothers, assessed by erythrocyte aspartate aminotransferase activity coefficient (EAST‐AC), is associated with an increased risk for isolated cleft lip with or without cleft palate (CL/P) in their children. Its association with the status assessed by plasma pyridoxal‐5′‐phosphate (PLP) concentrations is unknown.

METHODS:

In a case‐control study in the Philippines including 46 cases (mothers of a child with CL/P) and 392 controls (mothers of an unaffected child), we evaluated the association between the risk for CL/P and maternal vitamin B‐6 status assessed by PLP and EAST‐AC.

RESULTS:

The ORs of CL/P were estimated by classifying mothers by PLP (>30, 20–30, and <20 nmol/L). Using the highest PLP group as the reference, ORs (95% CIs) were 1.03 (0.45–2.37) and 2.66 (1.30–5.50) for the middle and lowest groups, respectively (p trend = .01). In multivariate models controlling for various covariates including folate, the risk for CL/P was approximately 12 times higher in mothers with inadequate vitamin B‐6 status, assessed by both PLP and EAST‐AC values, compared to those with adequate status by both values.

CONCLUSIONS:

Inadequate vitamin B‐6 status assessed by maternal PLP and EAST‐AC values independently and both combined was associated with an increased risk for CL/P. The association was highest when both values were considered, suggesting that the measurement of both PLP and EAST‐AC provides better assessment of vitamin B‐6 status than either measurement alone. Birth Defects Research (Part A) 2007. © 2007 Wiley‐Liss, Inc.
Assessment of developmental toxicity of vorinostat, a histone deacetylase inhibitor, in Sprague‐Dawley rats and Dutch Belted rabbits
Authors: Wise L. David , Turner Katie J. , Kerr Janet S.
Published: February 2007

BACKGROUND: The developmental toxicity potential of vorinostat (suberoylanilide hydroxamic acid [SAHA], ZOLINZA™), a potent inhibitor of histone deacetylase (HDAC), was assessed in Sprague‐Dawley rats and Dutch Belted rabbits. HDAC inhibitors have been shown to mediate the regulation of gene expression, induce cell growth, cell differentiation, and apoptosis of tumor cells. Range‐finding studies established oral dose levels of 5, 15, or 50 mg/kg/day and 20, 50, or 150 mg/kg/day in rats and rabbits, respectively. METHODS: Animals were dosed on Gestation Days 6–20 or 7–20, respectively, with litter/fetal parameters evaluated on GD 21 and 28, respectively. Separate studies evaluated toxicokinetic parameters at the mid‐ and high‐dose levels. RESULTS: There was no maternal toxicity observed at the highest dose levels; however, hematology and serum biochemistry changes were characterized in the range‐finding studies. Vorinostat did not induce morphological malformations in either rat or rabbit fetuses. In rats, drug‐related developmental toxicity was observed only in the high‐dose group and consisted of markedly decreased fetal weight and increases in fetuses with a limited number of skeletal variations. In rabbits, drug‐related developmental toxicity was also observed only in the high‐dose group and consisted of slightly decreased fetal weight and increases in fetuses with a short 13th rib and incomplete ossification of metacarpals. Maternal exposures to vorinostat based on AUC and Cmax values were comparable at the high‐dose levels of both species. Rabbits tolerated higher dosages probably due to more extensive metabolism. Maternal concentrations of vorinostat were ∼1,000–fold above the known in vitro HDAC inhibitory concentration. CONCLUSIONS: Review of previous work with valproic acid, another HDAC inhibitor, suggest that the developmental toxicity profiles of these 2 compounds are not the result of HDAC inhibition but involve other mechanisms. Birth Defects Res (Part B) 80:57–68, 2007. © 2007 Wiley‐Liss, Inc.
Die Fossilgeschichte des Menschen: Wie aus den ersten Primaten Homo wurde (Teil 1)
Authors: Welsch Ulrich
Published: February 2007

Der Entwicklungsweg des Menschen begann vor circa sechs Millionen Jahren, als sich die Entwicklungslinien von Mensch und Schimpansen trennten. In den vergangenen Jahrzehnten wurden mehr relevante Fossilfunde gemacht als in den gut 100 Jahren zuvor, so dass die Grundzüge der Evolution des Menschen mittlerweile recht gut bekannt sind. Die zunehmende Zahl an Forschern auch außerhalb Europas und der lässt erwarten, dass die Zahl der Funde in Zukunft noch wesentlich anwachsen wird, so dass Wissenslücken geschlossen werden, aber auch neue Interpretationen diskutiert werden müssen. Dieser zweiteilige Artikel bietet einen Überblick über gesicherte Erkenntnisse, spannende Funde – und offene Fragen.
Vegetation – der unterschätzte Klimafaktor: Treib‐ und Eishausklima in der Erdgeschichte
Authors: Mosbrugger Volker , Micheels Arne
Published: February 2007

Landpflanzen nehmen auf drei Wegen Einfluss auf die klimatischen Verhältnisse: über Veränderungen der Strahlungsbilanz, der Stoffkreisläufe und des Impulsaustausches. Beispiele aus der Erdgeschichte zeigen, wie groß dieser Einfluss der Vegetation auf das Klimageschehen sein kann. Im Karbon führte offensichtlich die Besiedlung des Festlandes durch Pflanzen zur Entwicklung eines Eishausklimas mit ausgedehnter Vereisung. Umgekehrt erlaubte zu Zeiten von Treibhausklimaten mit hohen CO2‐Konzentrationen die Ausbreitung der Wälder bis in hohe Breiten erst die Entwicklung eines global relativ ausgeglichenen Klimas mit warmen und eisfreien Polarregionen. Für alle Modelle, die das Klima der kommenden Jahrzehnte berechnen sollen, ist diese Wechselwirkung von entscheidender Bedeutung.
Zur Psychologie des Essens und Trinkens: Essen ist mehr als Ernährung
Authors: Pudel Volker
Published: February 2007

Aus der täglichen Aufgabe, Nahrung zu suchen, ist in der Überflussgesellschaft die Aufgabe geworden, sich für oder gegen Lebensmittel zu entscheiden. Die Verfügbarkeit von Lebensmitteln, der Mangel an körperlicher Aktivität und die auf Notzeiten ausgerichteten evolutionsbiologischen Programme überfordern das Individuum und lassen Ernährungsprobleme entstehen. 50 Jahre Ernährungsaufklärung mit überwiegend kognitiver Information (Verhaltensprävention) haben nicht zu einer Entschärfung der Ernährungsprobleme beigetragen. Mehr Chance wird der Verhältnisprävention eingeräumt, die Lebensbedingungen schaffen sollte, unter denen ein günstiges Ess‐ und ein aktiveres Bewegungsverhalten leichter fallen. Dazu könnte eine Optimierung der Speisenangebote in den öffentlichen Küchen ein wichtiger Schritt sein, wenn gesetzliche Rahmenbedingungen für die Realisierung sorgen.
Feinstaub bewirkt entzündliche Reaktion in der Lunge
Authors: Stöger Tobias , Schulz Holger
Published: February 2007

Bereits kurzzeitige Belastung mit Feinstaub führt zu entzündlichen Veränderungen in der Lunge, wie eine Studie des Nationalen Genomforschungsnetzes (NGFN) zeigt. In der Lunge von Mäusen, die über 24 Stunden Feinstaubpartikel eingeatmet hatten, sind verstärkt Gene und Proteine aktiv, die entweder an der Akutphase‐Antwort des Immunsystems oder an der Entstehung von Entzündungen beteiligt sind.
Chile: Begehrte Schnecken
Authors: Vasquez Nelson , Kronberg Inge
Published: February 2007

Meeresschnecken werden in Europa nur wenig verzehrt. In anderen Kontinenten ist besonders die algenfressende Haliotis (Meerohr) beliebt, die je nach der Fleischfarbe als rosa, grüne, rote, schwarze oder weiße Abalone gehandelt wird. Eine ähnliche große Meeresschnecke ist die chilenische Abalone (Concholepas concholepas), die zu den Raubschnecken (Muricidae) gehört, also eigentlich eine “falsche” Abalone ist. Sie wird in Chile und Peru als “loco” gesammelt und gegessen. Seit über 20 Jahren spielt auch der Export eine wachsende Rolle und hat zu einem Rückgang der Bestände geführt. Die Erforschung ihrer Biologie und Managementpläne unter Beteiligung der Küstenbewohner sollen das Problem lösen.
The Relevance of student seminars on clinically related subjects in a biochemistry course for medical and nutrition students
Authors: Hermes‐Lima Marcelo , Muniz Karinne C. , Coutinho Iracema S.
Published: February 2007

The aim of this study was to determine the value of a system of seminars on clinically related biochemistry topics for undergraduate students in medicine and nutrition at the University of Brasília, Brazil. During the second semester of 1998 (1998–2), the teaching staff decided to establish new and stricter rules for the seminar method and to adopt a system of peer tutoring, whereby former good to excellent students of the class Bioquímica e Biofísica helped in the planning and preparation of the oral presentations. The average performance grades for the seminars in the first semester of 1998 (1998–1) (7.19 ± 1.42) were significantly lower than those for the following semesters (ranging from 8.10 to 8.91), indicating some degree of success with the new system. We also conducted, by means of questionnaires, an evaluation (scores ranging from 0 to 4) of each student seminar (14 topics) in relation to the overall biochemistry learning experience connected to the clinical expectations of the students. All seminars but one averaged above 3.0. Moreover, when asked whether (i) the seminars were relevant to a more clinical approach to biochemistry and whether (ii) the oral presentations could be viewed as valid tools for the understanding of biochemistry, 96% (n = 188) and 80.6% (n = 150) of the students, respectively, answered, “yes.” The students also scored the work of the peer tutors high (ranging from 3.38 to 3.90, out of 4). A seminar system for a clinically related biochemistry course may also open the minds of students about the relevance of biochemistry to their future medical or nutritional practices.
Integrating internet assignments into a biochemistry/molecular biology laboratory course
Authors: Kaspar Roger L.
Published: February 2007

A main challenge in educating undergraduate students is to introduce them to the Internet and to teach them how to effectively use it in research. To this end, an Internet assignment was developed that introduces students to websites related to biomedical research at the beginning of a biochemistry/molecular biology laboratory course. The basic sites introduced cover many subjects, include searching for specific DNA sequences, restriction enzyme mapping, RNA folding, analyzing three‐dimensional protein images, and literature searches. These newly learned Internet skills are incorporated into other aspects of the laboratory course. In the example illustrated here, students sequence DNA inserts from randomly chosen bacterial colonies prepared from a human cDNA plasmid library. The obtained DNA sequence is used to search on‐line data bases introduced in the initial Internet assignment to determine whether the cDNAs have already been identified. The sequencing “wet‐lab” module, coupled with the Internet assignment, gives students experience in four areas. 1) purifying plasmid DNA, 2) performing restriction endonuclease digests on the plasmid DNA, 3) sequencing double‐stranded DNA, and 4) comparison of obtained sequence data to known DNA sequences in the human genome data base in a way that simulates a research experience.
The TRIPSE: A process‐oriented evaluation for problem‐based learning courses in basic sciences
Authors: Rangachari P. K.
Published: February 2007

A process‐oriented problem solving exercise is discussed that attempts to mimic the scientific process. This would be particularly useful for problem‐based courses in the basic biomedical sciences.
Practical studies on urine demonstrating principles of clinical and veterinary significance
Authors: Ryan J. Philip , Irwin Jane A.
Published: February 2007

Urine is a versatile and variable fluid that can be readily used in practical classes to demonstrate important biochemical and physiological principles. It can be readily adjusted to simulate a wide variety of medical conditions. This paper describes a range of easily performed experiments and includes some background on clinical and veterinary aspects. The experiments can be adapted for veterinary medicine, animal science, or medical students of biochemistry or physiology. To avoid any possibility of health risks posed by real urine samples, the experiments may be carried out on simulated samples. These experiments are ideal for laboratories with small resources.
Evaluation of molecular visualization software for teaching protein structure differing outcomes from lecture and lab: Differing outcomes from lecture and lab
Authors: White Brian , Kim Stella , Sherman Katerina , Weber Nicole
Published: February 2007

In this study we measured the learning outcomes resulting from using molecular visualization software in lecture and in the teaching laboratory of a large introductory‐level undergraduate biology majors' course. The study was initially carried out in the Fall semester of 1999; the results of this study were used to devise an expanded laboratory component that was evaluated in a second study carried out in the Fall of 2000. In both studies, students (n = 175 and 161) attended two 50‐min lectures that used molecular visualization software to explain protein structure and function and the gene‐protein connection. Students also used this software during one 3‐h laboratory session as a tool for exploring these topics. Students completed open‐ended pre‐ and post‐surveys that involved a related but unfamiliar task. Survey responses were scored for correctness, as well as by the type(s) of explanations used in the response. We found the following eight types of responses that students employed to explain protein structure and function: genetics, protein structure, chemical interactions, amino acid sequence, purpose/teleology, extrinsic factors, miscellaneous, and none. In both studies, the frequencies of correct answers, as well as the frequencies of each response type, showed significant changes as a result of lecture and/or lab. The effects of lecture were highly similar in both studies. The changes in the expanded lab resulted in significant changes in outcome. Overall, the curriculum effectively communicated several core concepts in protein biochemistry and expanded the conceptual “toolkit” that students applied to problems of protein structure and function. Lecture increased students' understanding of the role of amino acid sequence, whereas lab tended to increase their understanding of three‐dimensional structure and the gene‐protein connection. Our results demonstrate that exposure to molecular visualization, even for a relatively brief time, can improve students' understanding of protein structure and function. In addition, we demonstrate the differing and largely non‐overlapping effects of lecture and lab, suggesting that effective use of molecular visualization should involve both types of activities.
Investigating plant galactomannans
Authors: Mulimani Veerappa H. , Prashanth Sirigeri J.
Published: February 2007

This paper presents a review of biological importance and occurrence of galactomannan in plants. Its chemical composition and structure are reviewed, and a short laboratory practical exercise on the isolation and determination of D‐mannose/D‐galactose ratio of plant galactomannan is presented.
Understanding heterologous protein overproduction under the T7 promoter: A practical exercise
Authors: Christodoulou Evangelos , Vorgias Constantinos E.
Published: February 2007

Because various genome projects have been advanced many genes are known, and large amounts of proteins are required to elucidate their function. Most biomolecular research laboratories have a need to overexpress a certain gene, or a part of it, in eukaryotic or prokaryotic expression systems. It is therefore important for young students to become familiar with the technology of heterologous gene expression systems. Gene expression in eukaryotic cells is rather complicated and costly and is therefore not ideally suited to exercises for students. The goal of this paper is to describe an experimental example of a well known and broadly used prokaryotic system, the pET system, that works under the strong T7 promoter. The clones described in this paper are suitable for the practical exercise and are available upon request.
An experiment illustrating the effect of saline stress and ions on the malate dehydrogenase activity in vegetal tissues*
Authors: González‐Moreno Sergio , Perales‐Vela Hugo , Alvarez Martha O. Salcedo
Published: February 2007

This paper describes a simple, rapid, and economic protocol to evaluate the effect of saline stress and Na+, K+, Ca2+, and Mg2+ions on malate dehydrogenase activity in crude extracts from the leaves and roots ofVigna radiata. The main objectives of this work are to illustrate the effect of an environmental stress factor, as well as thein vitroeffect of some ions on an enzymatic activity, while introducing the students to the use of Michaelis‐Menten kinetics and a graphic procedure to calculate kinetics constants.
On the H+/2e− stoichiometry of the respiratory chain *
Authors: Guerra Guadalupe , Martínez Federico , Pardo Juan Pablo
Published: February 2007

To calculate the number of ATP molecules synthesized during oxidative phosphorylation, and to understand the yield and efficiency of this process, it is necessary to know the H+/2e− stoichiometry of the respiratory complexes, as well as the H+/ATP ratio for the ATP synthase. However, in most biochemistry textbooks, this topic is treated poorly. For example, several books simply mention that mitochondrial respiratory complexes pump protons across the membrane, without any reference to the number of protons translocated per pair of electrons [1–4]. Stryer's textbook [5] mentions a 4H+/2e−, 2H+/2e−, 4H+/2e− stoichiometry for complex I, III, and IV, respectively, but most recent editions of the biochemistry textbooks of Nelson and Cox [6] and Voet et al. [7] cite a 4, 4, 2 stoichiometry [6, 7]. Several years ago Hinkle et al. [8] proposed a 4, 2, 4 stoichiometry for the “effective” pumping of protons across the membrane; interestingly, these values are identical to the number of charges moved across the inner mitochondrial membrane by respiratory complexes I, III, and IV. The present work describes several arguments in favor of the stoichiometry of 4, 2, 4 for complex I, III, and IV, respectively.
Introduction to interpretation of stochastic parameters: Computer‐intensive procedures for evaluation of data in enzyme kinetics
Authors: Tenekedjiev Kiril , Kolev Krasimir
Published: February 2007

Computer simulation of a simple enzyme kinetic model is used to train medical students in interpretation of the stochastic nature of experimentally estimated model parameters. The principles for identification of parameters and estimation of their confidence intervals with the help of Monte Carlo procedures are introduced in a simplified and easily perceivable form.
An innovative selection and training program for problem‐based learning (PBL) workshop leaders in biochemistry*
Authors: Platt Terry , Barber Eugene , Yoshinaka Antoine , Roth Vicki
Published: February 2007

We describe here a novel and effective structure to support the replacement of traditional recitation sections in a large upper level biochemistry course with small student‐led problem‐based learning (PBL) groups (“workshops”) that employ a cooperative learning approach. This is part of an ongoing campus‐wide effort to establish and maintain such workshops as a viable and integral component of many undergraduate courses at the University of Rochester. In biochemistry, for each workshop group of 8–10 students, we rely on a student leader, usually recruited from the previous year's pool of top students, whose function is both to guide and to inspire the group effort. A crucial component of our approach is that these leaders participate in a semester‐long credit‐bearing training course co‐taught by the course instructors and an educational specialist. In this course, leaders review the preceding and upcoming weeks' workshops and study selected aspects of learning theory, group dynamics, and diversity training. Overall our workshop leaders feel that they benefit substantially from this training by improving their pedagogical skills in the context of biochemistry, by putting theories about group leadership and learning into practice, and by solidifying their working biochemical knowledge. We believe that the important features of implementing our model (the incorporation of a problem‐based learning approach into a student‐led small group format) are: 1) the teamwork as co‐equals between the course instructors and the educational specialists, 2) the concurrent iterative training of the workshop leaders in a credit‐bearing course of study, 3) the built‐in leader turnover (normally a frustrating occurrence) as a beneficial component of the course, and 4) the enthusiasm and commitment to biochemistry displayed to current students by their peer leaders.
A programmable $25 thermal cycler for PCR
Authors: Betsch David F. , Blais Brian S.
Published: February 2007

This article describes the construction of a safe, programmable, automatic thermal cycler for PCR that can be easily constructed by persons with basic soldering and mechanical skills for under $25 in parts and a modest computer such as IBM 486, all of which are readily available. The cycler relies on the heating provided by an incandescent light bulb and cooling by simple convection.
A laboratory exercise in comparative DNA analysis
Authors: Brown Lesley R.
Published: February 2007

This report describes a laboratory exercise that is used in an upper level biochemistry course at a small liberal arts college. The laboratory exercise was designed with three major learning objectives in mind. The first objective is that students learn how to isolate and purify plasmid DNA. The second is that they understand this process on a molecular level. Last, they analyze their DNA samples using a variety of biochemical and biophysical methods. By comparing and contrasting the results, they are to draw conclusions about which methods would be best under a given set of experimental conditions.
Determination of the molecular size of BSA by fluorescence anisotropy
Authors: González Flecha F. Luis , Levi Valeria
Published: February 2007

This work describes a laboratory experiment to illustrate the usefulness of fluorescence anisotropy in the field of biophysics. Fluorescence anisotropy of dansyl‐labeled BSA was determined in media of increasing glycerol concentrations. The Perrin equation was fitted to the experimental data, obtaining the molecular volume of the protein. The simplicity of the experiment and data analysis helped the students to focus on the relationship between probe anisotropy and rotational diffusion. Additionally, this laboratory exercise has the advantage of using a protein and a probe that are inexpensive and very common in many laboratories.
The regulation of the function of the tumor suppressor protein p53
Authors: Szeberenyi Jozsef
Published: February 2007

Terms to be familiar with before you start to solve the test: Tumor suppressor proteins; p53 protein; p53‐positive and p53‐negative tumors; transcription factors; protein phosphorylation; retinoblastoma protein; Go phase; apoptosis; chaperone; transfection; expression plasmid; cDNA; papillomavirus; Western blot analysis; γ‐irradiation; mitotic index; [3H]thymidine labeling.
Adapting a biochemistry course to distance education
Authors: Yokaichiya Daniela K. , Galembeck Eduardo , Torres Bayardo B.
Published: February 2007

Internet‐based distance education seems to be an attractive alternative to offer courses dealing with specific topics that are not conveniently explored in undergraduate courses. This is a good way to provide access to the recent and updated discoveries in this research area and to reach people who could not take the classes in the traditional mode. Using the communication advantages available via the Internet, we adapted the course “Biochemistry of Nutrition,” first offered as a summer course to be entirely carried out at distance. The adaptation explored the use of online tools such as E‐mail communication among students and teachers, computer conferencing in small groups to discuss specific subjects, and texts and software downloads to be used as main references. Graduate students had their first real experience as teachers, which proved to be very productive for both the development of the Internet version of the course and their integration with undergraduate students.
The zymogen‐enteropeptidase system: A practical approach to study the regulation of enzyme activity by proteolytic cleavage*
Authors: Pizauro João M. , Ferro Jesus A. , de Lima Andréa C. F. , Routman Karina S. , Portella Maria Célia
Published: February 2007

The present research describes an efficient procedure to obtain high levels of trypsinogen and chymotrypsinogen by using a simple, rapid, and easily reproducible method. The extraction process and the time‐course of activation of zymogens can be carried out in a single laboratory period, without sophisticated equipment. The main objective was to prepare a laboratory class that would stimulate student interest in enzyme regulation, exploring the fact that the catalytic activity of some enzymes is regulated by different mechanisms. The regulation of proteolytic enzymes requires the synthesis of an inactive zymogen and its being irreversibly “switched on” by specific proteolytic cleavage.
The expression of ovomucoid gene*
Authors: Szeberenyi Jozsef
Published: February 2007

Terms to be familiar with before you start to solve the test: gene expression, isolation of RNA, Northern blotting, hybridization, autoradiography, pre‐mRNA splicing, exons and introns, poly(A) tail, and triplet code.
An hypothesis‐driven, molecular phylogenetics exercise for college biology students
Authors: Parker Joel D. , Ziemba Robert E. , Cahan Sara Helms , Rissing Steven W.
Published: February 2007

This hypothesis‐driven laboratory exercise teaches how DNA evidence can be used to investigate an organism's evolutionary history while providing practical modeling of the fundamental processes of gene transcription and translation. We used an inquiry‐based approach to construct a laboratory around a nontrivial, open‐ended evolutionary question about the relationship of five species ofDrosophila. In the course of answering this question, students at the early college biology level learn how the information in DNA can be extracted and used by both the cell and scientists. This dual proximate‐ultimate approach introduces students to the techniques of PCR, DNA sequencing, and phylogenetic sequence analysis while simultaneously providing a concrete pen‐and‐paper model of the cellular processes of transcription and translation. The laboratory has been successfully employed over 3 years with first‐year college students and has proven its versatility by being easily adapted to a “dry lab” form with advanced high school students.
Formation and detoxification of reactive oxygen species
Authors: Kuciel Radosława , Mazurkiewicz Aleksandra
Published: February 2007

A model of reactive oxygen species metabolism is proposed as a laboratory exercise for students. The superoxide ion in this model is generated during the reaction of oxidation of xanthine, catalyzed by xanthine oxidase. The effect of catalase, superoxide dismutase, and allopurinol on superoxide ion generation and removal in this system is also determined, using cytochrome c as a probe.
Thermodynamic properties of peptide folding
Authors: Sigman Jeffrey A.
Published: February 2007

Inter‐ and intramolecular forces and thermodynamics are concepts usually presented early within introductory biochemistry and have relevance to many topics throughout the remainder of the course. For this reason, it is important to have a good foundation in these concepts so they can be applied to many systems. To this end, a group problem has been developed that allows students to analyze thermodynamic data and, using their knowledge of inter‐ and intramolecular forces, gain an understanding of the elements involved in the thermodynamic stability and folding of a peptide.
An introductory bioinformatics exercise to reinforce gene structure and expression and analyze the relationship between gene and protein sequences
Authors: Almeida Craig A. , Tardiff Daniel F. , De Luca Jane P.
Published: February 2007

We have developed an introductory bioinformatics exercise for sophomore biology and biochemistry students that reinforces the understanding of the structure of a gene and the principles and events involved in its expression. In addition, the activity illustrates the severe effect mutations in a gene sequence can have on the protein product. Students search GenBank for the wild‐type nucleotide sequence of the Caenorhabditis elegans unc‐22 gene, the amino acid sequence of its gene product, and the nucleotide sequence of the transposon Tc5. The nucleotide sequences are manipulated using two programs in the Lasergene® software package from DNASTAR®. The first program, EditSeq®, enables students to experience the meticulous process required to precisely locate and remove intron sequences from the wild‐type unc‐22 allele to generate a cDNA sequence. The unc‐22(r466) allele is generated by inserting the sequence of the transposon Tc5 into the appropriate location of the third exon in unc‐22. The open reading frames of both cDNAs are located and then translated. MegAlign®, the second program, aligns the wild‐type sequence of the UNC‐22 protein and the wild‐type and mutant protein sequences that were constructed. The degree of sequence similarity between the aligned proteins allows students to verify their success in processing the gene, as well as to visualize the truncated protein product from the Tc5 mutant allele. Student feedback and possible modifications to the exercise as well as supplemental exercises are also discussed.