bluuebunny/crossref_metadata_2025 huggingface dataset:
Protective Effects of Piceatannol against Beta‐Amyloid–Induced Neuronal Cell Death
Authors: KIM HYO JIN , LEE KI WON , LEE HYONG JOO
Published: April 2007

Abstract:  Beta‐amyloid (Aβ) is a main component of senile plaques in Alzheimer's disease (AD) that induces neuronal cell death. Since reactive oxygen species (ROS) have been implicated in Aβ‐induced neurotoxicity, considerable attention has recently been focused on identifying naturally occurring antioxidative phenolic phytochemicals that are able to decrease ROS levels. Piceatannol (trans‐3,4,3′,5′‐tetrahydroxystilbene), which has a structure homologous to resveratrol, is an anti‐inflammatory and antiproliferative stilbene compound derived from plants. This article investigated the possible protective effects of piceatannol on Aβ‐induced PC12 neuronal cell death, and found that piceatannol exerted much stronger protective effects than did resveratrol. Piceatannol treatment attenuated the intracellular accumulation of ROS induced by treatment of PC12 cells with Aβ, inhibited Aβ‐induced apoptotic features including internucleosomal DNA fragmentation, nucleus condensation, cleavage of poly(ADP‐ribose) polymerase (PARP), and activation of caspase‐3. These results suggest that piceatannol blocks Aβ‐induced accumulation of ROS, thereby protecting PC12 cells from oxidative stress.
Jaceosidin Induces Apoptosis in ras‐Transformed Human Breast Epithelial Cells through Generation of Reactive Oxygen Species
Authors: KIM MIN‐JUNG , KIM DO‐HEE , LEE KI WON , YOON DO‐YOUNG , SURH YOUNG‐JOON
Published: April 2007

Abstract:  Extracts of Artemisia plants possess anti‐inflammatory and antioxidative activities. Eupatilin (5,7‐dihydroxy‐3′,4′,6‐tri‐methoxy‐flavone), a pharmacologically active flavone derived from Artemisia asiatica, was shown to inhibit phorbol ester‐induced cyclooxygenase‐2 expression and NF‐κB activation in mouse skin, and also to induce cell cycle arrest in ras‐transformed human mammary epithelial (MCF10A‐ras) cells. In this article, we examined the ability of jaceosidin (4′,5,7‐trihydroxy‐3′,6‐dimethoxyflavone) isolated from Artemisia argyi to inhibit the proliferation of MCF10A‐ras cells. Jaceosidin reduced the viability of MCF10A‐ras cells to a greater extent than eupatilin. Jaceosidin treatment resulted in increased intracellular accumulation of reactive oxygen species (ROS) in MCF10A‐ras cells, which was blocked by the antioxidant N‐acetylcysteine (NAC). NAC attenuated jaceosidin‐induced cytotoxicity. To better assess the proapoptotic effects of jaceosidin, we analyzed the treated cells by the flow cytometry. MCF10A‐ras cells treated with jaceosidin (100 μM) exhibited the increased proportion of hypodiploid or apoptotic cells (48.72% as composed to 7.78% in control cells). Jaceosidin treatment also increased the ratio of proapoptotic Bax to the antiapoptotic Bcl‐2 and induced the cleavage of caspase‐3 and poly(ADP‐ribose)polymerase (PARP). Moreover, jaceosidin elevated the expression of p53 and p21, while the compound inhibited the activation of ERK1/2 that is an important component of cell survival signaling.
Caspase Activation and Extracellular Signal‐Regulated Kinase/Akt Inhibition Were Involved in Luteolin‐Induced Apoptosis in Lewis Lung Carcinoma Cells
Authors: KIM JIN‐HYUNG , LEE EUN‐OK , LEE HYO‐JUNG , KU JIN‐SOOK , LEE MIN‐HO , YANG DEOK‐CHUN , KIM SUNG‐HOON
Published: April 2007

Abstract: Luteolin was isolated fromScutellaria barbataD. Don (S. barbata). In the present study, we examined the underlying molecular mechanism of luteolin and its effect onin vivotumor growth of Lewis lung carcinoma (LLC) cells. Luteolin exhibited antiproliferative activity against LLC cells with IC50of 12 μM. Luteolin effectively increased Annexin‐V‐positive cells as well as sub G1DNA portion as seen on flow cytometric analysis. Western blotting has revealed that luteolin effectively activates caspase 9 and 3, cleaves poly (ADP‐ribose) polymerase (PARP), and increases the ratio of Bax/Bcl‐2. Furthermore, mitochondrial membrane potential was reduced by luteolin as seen on fluorescence microscopy. Luteolin downregulated the expression of extracellular signal‐regulated kinase (ERK) and Akt in a concentration‐dependent manner. In addition, luteolin significantly inhibited the growth of LLC cells implanted on the flank of mice to 40% and 60% of untreated control group values at 2 mg/kg and 10 mg/kg, respectively. Similarly, luteolin significantly reduced the expression of proliferating cell nuclear antigen (PCNA) as well as increased the expression of terminal deoxynucleotidyl transferase biotin‐dUTP nick end labeling (TUNEL) in tumor section of LLC‐bearing mice as determined by immunohistochemistry. Taken together, these results suggest that luteolin exerts antitumor activity by caspase activation and ERK/Akt inhibition.
Henry Reaction and 1,4-Addition of Nitroalkanes to α,β-Unsaturated Carbonyl Compounds under the Influence of MS 4 Å in DMSO
Authors: Oriyama Takeshi , Aoyagi Masaru , Iwanami Katsuyuki
Published: April 2007

In the presence of MS 4 Å in DMSO (dimethyl sulfoxide), Henry reaction with various carbonyl compounds and nitroalkanes proceeded smoothly to give the corresponding β-nitroalcohol without a base catalyst. Moreover, 1,4-additon of nitroalkane to α,β-unsaturated ketones was also performed in DMSO.
Tapping to a Very Slow Beat: A Comparison of Musicians and Nonmusicians
Authors: Repp Bruno H. , Doggett Rebecca
Published: April 2007

WHEN NONMUSICIANS TAP with isochronous auditory tone sequences, the taps typically precede the tone onsets. However, when the tone inter-onset interval (IOI) is increased beyond 2 s, an increasing proportion of taps follows the tone onsets by 150 ms or more. Such responses indicate reactions rather than anticipations, and they have been interpreted as reflecting a rate limit of synchronization related to a temporal limit of auditory working memory. In the present study, musicians and nonmusicians were asked to synchronize their taps with sequences whose IOIs ranged from 1000 to 3500 ms. Nonmusicians showed much larger anticipation errors and higher variability but actually fewer reactive responses than musicians. No clear landmarks of a rate limit for synchronization were observed.
Can Juvenile Justice Detention Facilities Meet the Call of the American Academy of Pediatrics and National Commission on Correctional Health Care? A National Analysis of Current Practices
Authors: Gallagher Catherine A. , Dobrin Adam
Published: April 2007

OBJECTIVE. Despite the recommendation of the American Academy of Pediatrics, just 53 of the ∼3500 juvenile justice residential facilities in the United States have received voluntary accreditation for facility health care from the National Commission on Correctional Health Care. This suggests either that facilities do not meet the standards of care or do not seek accreditation. This study describes whether and under what conditions juvenile detention facilities (a narrowly defined subset of all facility types) adhere to some of the standards outlined by the National Commission on Correctional Health Care and promoted by the American Academy of Pediatrics.

METHODS. Data from 2 national censuses of juvenile justice residential facilities (n = 726) were used to describe detention facility performance in terms of 10 types of service provision, ranging from health screening to communicable-disease testing. Multivariate models predicting high levels of service provision were estimated.

RESULTS. Juvenile detention centers partially meet some of the minimum standards. Most services can be garnered at some level; however, they tend to be provided on an ad hoc basis for portions of the population rather than systematically for the whole population. Detention centers most likely to provide a higher tier of services tend to be those that have longer average lengths of stay, are larger, and are government owned. There are also geographic and racial differences in quality and scope of health services.

CONCLUSIONS. Juvenile facilities have been provided a single set of standards for a diverse system with tremendous variation across and within facility types. Detention centers are just one specialized type. Very few detention centers meet a minimum standard of care, which suggests that standards are simply not being met (hence the low levels of accreditation). The findings of this study call into question whether detention facilities with little in the way of health care infrastructure can benefit from National Commission on Correctional Health Care standards as they are currently packaged, regardless of whether accreditation is the ultimate goal.
Masculine Beliefs, Parental Communication, and Male Adolescents' Health Care Use
Authors: Marcell Arik V. , Ford Carol A. , Pleck Joseph H. , Sonenstein Freya L.
Published: April 2007

OBJECTIVES. Male adolescents frequently become disconnected from health care, especially as they get older, which limits physicians' abilities to address their health needs and results in missed opportunities to connect them to the health care system as they enter adulthood. In this study we tested the ability of modifiable (beliefs about masculinity, parental communication, sex education, and health insurance) and nonmodifiable (age, race/ethnicity, and region of residence) factors to prospectively predict health care use by male adolescents.

PATIENTS AND METHODS. We conducted a prospective analysis of data from 1677 male participants aged 15 to 19 years who completed the National Survey of Adolescent Males, a household probability survey conducted throughout the United States in 1988 (wave 1, participation rate: 74%) and in 1990–1991 (wave 2, follow-up rate: 89%). We present percentages and adjusted relative risks of the factors that predict male adolescents' self-report of a physical examination by a regular provider in the past year measured at wave 2.

RESULTS. On average, 1067 (66%) of 1677 male adolescents at wave 2 reported having a physical examination within the last year. Factors associated with a lower likelihood of a physical examination included living in the South, Midwest, and West; being older in age; and holding more traditional masculine beliefs. Factors associated with a higher likelihood of a physical examination included communicating about reproductive health with both parents and being insured. Male adolescents who were sexually active or engaged in ≥2 other risk behaviors had neither a higher nor lower likelihood of a physical examination.

CONCLUSIONS. Efforts to enhance male adolescents' health through health care should include work to modify masculine stereotypes, improve mothers' and fathers' communication about health with their sons, expand health insurance coverage, and identify interventions to connect male adolescents at increased risk for health problems with health care.
Quantification of Deep Gray Matter in Preterm Infants at Term-Equivalent Age Using Manual Volumetry of 3-Tesla Magnetic Resonance Images
Authors: Srinivasan Latha , Dutta Robin , Counsell Serena J. , Allsop Joanna M. , Boardman James P. , Rutherford Mary A. , Edwards A. David
Published: April 2007

OBJECTIVE. Nonhypothesis-based MRI-analysis techniques including deformation-based morphometry and automated tissue segmentation have suggested that preterm infants at term-equivalent age have reduced tissue volume in the basal ganglia and thalami, which is most apparent among infants with supratentorial lesions. The aim of our study was to test this hypothesis by direct measurement of thalamic and lentiform nuclei volumes in preterm infants at term-equivalent age and term-born controls using manual volumetry.

DESIGN/METHODS. Forty preterm infants at term-equivalent age (median gestational age: 29.5 weeks; median birth weight: 1.3 kg) and 8 term-born controls were examined using a 3-T Philips (Best, Netherlands) system. T1-weighted volume images and T2-weighted fast-spin echo pseudovolumes were acquired. There was no significant difference in postmenstrual age at image acquisition between the 2 groups. ImageJ 1.34 (National Institutes of Health, Bethesda, MD) was used for manual segmentations.

RESULTS. The median thalamic and lentiform nuclei volumes for preterm infants at term-equivalent age were 13.6 and 3.07 cm3, respectively, significantly smaller than term-control volumes of 16.3 and 5.6 cm3, respectively. Ten preterm infants at term-equivalent age had supratentorial lesions (intraventricular hemorrhage, periventricular leukomalacia, or hemorrhagic parenchymal infarction), and the median thalamic and lentiform volumes for this group were 10.4 and 1.7 cm3, respectively. When this group was excluded, the remaining infants who had mild or moderate diffuse excessive high signal intensity in the white matter on T2-weighted images had a smaller, yet significant, volume reduction compared with controls. Tissue volumes were not related to weight and gestational age at birth.

CONCLUSIONS. Manual volumetry confirms that preterm infants at term-equivalent age have reduced thalamic and lentiform volumes compared with controls. This was most marked among infants with supratentorial lesions but was also seen among those with nonfocal white matter abnormalities.
Family-Centered Bedside Rounds: A New Approach to Patient Care and Teaching
Authors: Muething Stephen E. , Kotagal Uma R. , Schoettker Pamela J. , del Rey Javier Gonzalez , DeWitt Thomas G.
Published: April 2007

The importance of patient-centered care and the role of families in decision-making are becoming more recognized. Starting with a single acute care unit, a multidisciplinary improvement team at Cincinnati Children's Hospital developed and implemented a new process that allows families to decide if they want to be part of attending-physician rounds. Family involvement seems to improve communication, shares decision-making, and offers new learning for residents and students. Despite initial concerns of staff members, family-centered rounds has been widely accepted and spread throughout the institution. Here we report our experiences as a potential model to improve family-centered care and teaching.
Do All Infants With Apparent Life-Threatening Events Need to Be Admitted?
Authors: Claudius Ilene , Keens Thomas
Published: April 2007

OBJECTIVE. The goal was to identify criteria that would allow low-risk infants presenting with an apparent life-threatening event to be discharged safely from the emergency department.

METHODS. We completed data forms prospectively on all previously healthy patients <12 months of age presenting to the emergency department of an urban tertiary care children's hospital with an apparent life-threatening event over a 3-year period. These patients were then observed for subsequent events, significant interventions, or final diagnoses that would have mandated their admission (eg, sepsis).

RESULTS. In our population of 59 infants, all 8 children who met the aforementioned outcome measures, thus requiring admission, either had experienced multiple apparent life-threatening events before presentation or were in their first month of life. In our study group, the high-risk criteria of age of <1 month and multiple apparent life-threatening events yielded a negative predictive value of 100% to identify the need for hospital admission.

CONCLUSIONS. Our study suggests that >30-day-old infants who have experienced a single apparent life-threatening event may be discharged safely from the hospital, which would decrease admissions by 38%.
Incidence, Complications, and Risk Factors for Prolonged Stay in Children Hospitalized With Community-Acquired Influenza
Authors: Coffin Susan E. , Zaoutis Theoklis E. , Rosenquist Anna B. Wheeler , Heydon Kateri , Herrera Guillermo , Bridges Carolyn B. , Watson Barbara , Localio Russell , Hodinka Richard L. , Keren Ron
Published: April 2007

OBJECTIVES. Few studies have examined the characteristics and clinical course of children hospitalized with laboratory-confirmed influenza. We sought to (1) estimate the age-specific incidence of influenza-related hospitalizations, (2) describe the characteristics and clinical course of children hospitalized with influenza, and (3) identify risk factors for prolonged hospitalization.

PATIENTS AND METHODS. Children ≤21 years of age hospitalized with community-acquired laboratory-confirmed influenza at a large urban children's hospital were identified through review of laboratory records and administrative data sources. A neighborhood cohort embedded within our study population was used to estimate the incidence of community-acquired laboratory-confirmed influenza hospitalizations among children <18 years old. Risk factors for prolonged hospitalization (>6 days) were determined by using logistic regression.

RESULTS. We identified 745 children hospitalized with community-acquired laboratory-confirmed influenza during the 4-year study period. In this urban cohort, the incidence of community-acquired laboratory-confirmed influenza hospitalization was 7 per 10000 child-years of observation. The median age was 1.8 years; 25% were infants <6 months old, and 77% were children <5 years old. Many children (49%) had a medical condition associated with an increased risk of influenza-related complications. The incidence of influenza-related complications was higher among children with a preexisting high-risk condition than for previously healthy children (29% vs 21%). However, only cardiac and neurologic/neuromuscular diseases were found to be independent risk factors for prolonged hospitalization.

CONCLUSIONS. Influenza is a common cause of hospitalization among both healthy and chronically ill children. Children with cardiac or neurologic/neuromuscular disease are at increased risk of prolonged hospitalization; therefore, children with these conditions and their contacts should be a high priority to receive vaccine. The impact on pediatric hospitalization of the new recommendation to vaccinate all children 6 months to <5 years old should be assessed.
Prevention of Influenza: Recommendations for Influenza Immunization of Children, 2006–2007
Authors:   Committee on Infectious Diseases
Published: April 2007

The purpose of this statement is to update recommendations for routine use of influenza vaccine in children for the 2006–2007 influenza season. The American Academy of Pediatrics recommends annual influenza immunization for (1) children with high-risk conditions who are 6 months and older; (2) healthy children 6 through 59 months of age; (3) household contacts and out-of-home caregivers of children with high-risk conditions and all healthy children younger than 5 years; and (4) health care professionals. Other children, adolescents, and adults can be immunized to decrease the impact of influenza as indicated in the Red Book: 2006 Report of the Committee on Infectious Diseases.
Maize population hybrids: Successful genetic resources for breeding programs and potential alternatives to single-cross hybrids
Authors: Carena M.
Published: April 2007

Conservation of maize (
Zea mays
L.) genetic resources has been the emphasis of national and international institutions for the benefit of mankind. However, limited resources have been devoted to their adequate exploitation, making genetic resources less useful to the public and private scientific community. As a consequence, public maize breeders have exploited a limited number of heterotic combinations for cultivar development and basic molecular studies while genetic effects are different for different hybrids. Extensive testing of maize population hybrids is a successful approach to choose and improve germplasm sources with high mean performance, useful genetic variability, and excellent combining ability. There is a need to keep applied breeding programs strong in order to link efforts in germplasm conservation with its improvement and utilization.
Quality responses of winter wheat cultivars to nitrogen and fungicide applications in Croatia
Authors: Varga B. , Svečnjak Z. , Jurković Z. , Pospišil M.
Published: April 2007

Winter wheat (
Triticum aestivum
L.) cultivars may differ in grain quality responses to nitrogen (N) and fungicide applications, the two most important management inputs in the temperate climates of Europe. Limited information is available on N and fungicide effects on wheat quality in Croatia, where the wheat crop is widely grown under low N inputs without fungicide application. Field experiments were conducted during three years to evaluate the effects of fungicide (tebuconazol applied around heading) and two N fertilization rates on the grain quality of six widely grown winter wheat cultivars. Most cultivars failed to achieve the minimum breadmaking standards at a low N rate because of low protein content (103 g kg
−1
), Zeleny sedimentation (22.2 cm
3
) and wet gluten (201 g kg
−1
). High N fertilization significantly increased these quality traits in all cultivars (an average of 21% for grain protein, 58% for Zeleny sedimentation and 40% for wet gluten). However, some cultivars with low genetic potential for accumulating grain protein failed to reach the breadmaking quality even at a high N rate when the N availability in the soil was limited by drought. Significant cultivar × N interactions existed for all grain quality traits, but were mainly associated with differences in the magnitude of the responses and less with the ranks. Five cultivars consistently showed increased falling number as the N rate rose, but these cultivar-specific responses to N fertilization were of much lesser magnitude than those across years. Fungicide application showed no effect on grain protein. Zeleny sedimentation, wet gluten or gluten index in all six cultivars tested, whereas one cultivar consistently showed decreased falling number after fungicide use. Only the hectolitre weights increased following fungicide application, especially for disease-susceptible cultivars at the high N rate. Thus, high N fertilization resulted in cultivar-dependent increases in protein content, Zeleny sedimentation, wet gluten and falling number, whereas fungicide application had no effect on grain quality except improved hectolitre weights.
INCREASING FICTION WRITERS' PRODUCTIVITY THROUGH AN INTERNET‐BASED INTERVENTION
Authors: Porritt Matthew , Burt Andrew , Poling Alan
Published: April 2007

Ten participants from an online community of fiction writers were exposed to a treatment package intended to increase their writing productivity. The package consisted of graphic feedback provided through a Web page, praise for goal completion delivered via e‐mail, and editing of manuscripts by other members of the community dependent on the completion of word‐count goals. A multiple baseline design across groups was used to evaluate the effects of the intervention, which was successful in increasing the number of words written.
Occurrence of Periodontopathic and Superinfecting Bacteria in Chronic and Aggressive Periodontitis Subjects in a Colombian Population
Authors: Botero Javier Enrique , Contreras Adolfo , Lafaurie Gloria , Jaramillo Adriana , Betancourt Marisol , Arce Roger Mauricio
Published: April 2007

Background: Differences in the composition of subgingival microbiota in periodontitis have been observed in different geographic locations. Some of these microbial differences could have clinical significance. This study describes clinical parameters and the composition of the subgingival microbiota in chronic periodontitis (CP) and aggressive periodontitis (AgP) patients in a Colombian population.

Methods: Clinical parameters (probing depth, clinical attachment level, bleeding on probing, and plaque index) and plaque samples from 68 CP, 12 AgP, and 30 periodontally healthy subjects were analyzed. Subgingival samples were processed using culture, biochemical tests, and polymerase chain reaction for the detection of periodontal and superinfecting pathogens. The analysis of variance, χ2, and Kruskal‐Wallis tests were used to evaluate differences between groups for clinical parameters and microbiologic composition (P ≤0.05).

Results: Clinical parameters were significantly increased in CP and AgP patients compared to healthy subjects (P <0.001), but no differences were found between periodontitis groups. Porphyromonas gingivalis, Tannerella forsythensis, and Eikenella corrodens showed higher frequencies in AgP compared to CP and healthy subjects (P <0.05). Extension (localized and generalized) of the periodontal destruction had no effect on the composition of the subgingival microbiota. Gram‐negative enteric rods were more frequent in AgP patients (P <0.01).

Conclusions: This study demonstrated a high prevalence of P. gingivalis, T. forsythensis, and E. corrodens in AgP patients. Gram‐negative enteric rods were frequent in AgP and CP patients. Differences in the composition of subgingival microbiota in periodontitis patients need to be taken into account when considering the best therapeutic approach for each individual, including the use of antibiotics.
Clinical Crown Length of the Maxillary Anterior Teeth Preorthodontics and Postorthodontics
Authors: Konikoff Bryan M. , Johnson David C. , Schenkein Harvey A. , Kwatra Naveen , Waldrop Thomas C.
Published: April 2007

Background: Prevalence information on excessive gingival display in postorthodontic patients is limited. By studying the size relationship of the clinical crowns of teeth, in an orthodontic population, we can begin to quantify their need for periodontal plastic surgery.

Methods: Preorthodontic and postorthodontic crown dimensions were measured on 200 plaster models, and after 5 years, 31 of the subjects were recalled to repeat the measurements in a clinical examination. The measurements included clinical crown lengths and widths of the six anterior teeth, and these values were compared to known ideals.

Results: This study revealed a significant increase in the length of the maxillary anterior crowns over the three examinations, yet these values were still ∼1.5 mm shorter than ideal. The mean crown width‐to‐length ratio was 87% to 88% for maxillary central incisors, clearly above the accepted “ideal.” In addition, 61% to 71% of maxillary central incisors exceeded allowable crown width‐to‐length ratios, and 61% of subjects displayed asymmetry in gingival architecture.

Conclusions: Although this study only examined one aspect of excessive gingival display, to our knowledge it is the first study to show that in a predominantly young, postorthodontic population, the prevalence of non‐ideal width‐to‐length ratios is >65% and the presence of asymmetry is >60%. Therefore, close interaction between the periodontist and the orthodontist is necessary to diagnose these conditions to provide patients with all options for improving their smile.
Effects of Platelet Concentrate on Palatal Wound Healing After Connective Tissue Graft Harvesting
Authors: Yen C. Alec , Griffin Terrence J. , Cheung Wai S. , Chen Jake
Published: April 2007

Background: Platelet concentrate (PC) is known to contain growth factors that stimulate cellular proliferation and differentiation. In this double‐blind, placebo‐controlled, randomized study, the objective was to determine whether PC accelerated connective tissue graft (CTG) wound healing and maintained donor site tissue thickness.

Methods: Twenty healthy adult subjects with multiple bilateral gingival recessions were treated with CTGs and PC combined with CTGs. The donor sites were treated with PC and placebo. Clinical wound healing was observed for an average of 6 weeks. Biopsies were taken from donor sites and submitted for histology and immunohistochemical analysis for type I and III collagens. Palatal tissue thickness, post‐surgical complications, and pain level were evaluated. Wilcoxon, Cronbach, one‐sample t, and paired‐sample t tests were used to assess statistical significance at P <0.05.

Results: PC‐treated palatal donor sites were 1.10 mm thicker than control sites. PC‐treated recipient sites showed accelerated clinical healing compared to controls. PC did not accelerate donor site clinical healing. No significant statistical differences in complication occurrence and perceived pain levels were found between control and PC‐treated sites. Biopsy samples revealed that during healing, PC‐treated sites contained lower concentrations of inflammatory cells, more type I mature collagen, and less type III immature collagen than control sites.

Conclusions: PC may accelerate wound healing and hasten the regeneration of palatal donor tissue. PC did not influence complication occurrences or mediate pain level. PC has the potential to shorten the treatment time for patients who need multiple CTG procedures.
Platelet‐Rich Plasma: Growth Factors and Pro‐ and Anti‐Inflammatory Properties
Authors: El‐Sharkawy Hesham , Kantarci Alpdogan , Deady Jennifer , Hasturk Hatice , Liu Hongsheng , Alshahat Mohammad , Van Dyke Thomas E.
Published: April 2007

Background: Platelet‐rich plasma (PRP) promotes regeneration of bone, presumably through the action of concentrated growth factors. However, it is not clear how PRP affects the inflammatory response. The purpose of this study was to analyze the growth factors in PRP and to study the effects of PRP on monocyte cytokine release and lipoxin A4 (LXA4) generation.

Methods: PRP was prepared from healthy donors. Platelet‐derived growth factor (PDGF)‐AB, PDGF‐BB, transforming growth factor‐β1, insulin‐like growth factor‐I, fibroblast growth factor‐basic (FGF‐b), epidermal growth factor (EGF), vascular endothelial growth factor, interleukin‐12 (p40/70), and regulated on activation, normal T‐cell expressed and secreted (RANTES) levels were evaluated by enzyme‐linked immunosorbent assay and bead‐based multiplexing. Peripheral blood monocytes were isolated and cultured with or without PRP. Cytokine, chemokine, and LXA4 levels as well as monocyte chemotactic migration were analyzed.

Results: Growth factors were increased significantly in PRP compared to whole blood (WB) and platelet‐poor plasma. Monocyte chemotactic protein‐1 (MCP‐1) was suppressed significantly by PRP, whereas RANTES was increased significantly in monocyte cultures. LXA4 levels were significantly higher in PRP compared to WB. PRP stimulated monocyte chemotaxis in a dose‐dependent fashion, whereas RANTES, in part, was responsible for PRP‐mediated monocyte migration.

Conclusions: PRP is a rich source of growth factors and promoted significant changes in monocyte‐mediated proinflammatory cytokine/chemokine release. LXA4 was increased in PRP, suggesting that PRP may suppress cytokine release, limit inflammation, and, thereby, promote tissue regeneration.
Impact of the Distinct Sampling Area on Volumetric Features of Gingival Crevicular Fluid
Authors: Hatipoğlu Hasan , Yamalik Nermin , Berberoğlu Atilla , Eratalay Kenan
Published: April 2007

Background: Volumetric features of gingival crevicular fluid (GCF) are under the influence of many factors, including sampling variables. Standardizing such factors may enable a more precise methodology. Thus, analysis of the possible impact of the clinical periodontal status and the distinct location of sampling sites on fluid volume was performed.

Methods: Clinical parameters were recorded, and fluid samples were obtained from 931 maxillary sites. The potential site‐specific volumetric differences among healthy, gingivitis, and periodontitis sites; between multirooted or single‐rooted teeth and mesio‐buccal or disto‐buccal sampling sites; and the correlations between volume and clinical measures were statistically analyzed.

Results: Although volume increased in a disease‐related pattern (healthy < gingivitis < periodontitis; P <0.05), the distribution range of volume was widespread, with prominent overlaps between the different clinical periodontal conditions. Multirooted teeth presented more fluid volume, and even mesio‐buccal or disto‐buccal sites exhibited some volumetric differences (P <0.05). Constant correlations between volume and clinical parameters could be observed only at gingivitis sites (P <0.05).

Conclusions: The spectrum of fluid volume is disease related in general. However, the wide range of volumetric distribution, the site‐specific nature, and the clear impact of the distinct sampling site on volume are important volumetric features of this biologic fluid. Whenever possible, standardization of the extent of probing depth, degree of gingival inflammation, and distinct sampling area is likely to improve the reliability of GCF methodology.
Transforming Growth Factor‐β1 Accelerates Resorption of a Calcium Carbonate Biomaterial in Periodontal Defects
Authors: Koo Ki‐Tae , Susin Cristiano , Wikesjö Ulf M.E. , Choi Seong‐Ho , Kim Chong‐Kwan
Published: April 2007

Background: In a previous study, recombinant human transforming growth factor‐beta1 (rhTGF‐β1) in a calcium carbonate carrier was implanted into critical‐size, supraalveolar periodontal defects under conditions for guided tissue regeneration (GTR) to study whether rhTGF‐β1 would enhance or accelerate periodontal regeneration. The results showed minimal benefits of rhTGF‐β1, and a clear account for this could not be offered. One potential cause may be that the rhTGF‐β1 formulation was biologically inactive. Several growth or differentiation factors have been suggested to accelerate degradation of biomaterials used as carriers. The objective of this study was to evaluate possible activity of rhTGF‐β1 on biodegradation of the calcium carbonate carrier.

Methods: rhTGF‐β1 in a putty‐formulated particulate calcium carbonate carrier was implanted into critical‐size, supraalveolar periodontal defects under conditions for GTR in five beagle dogs. Contralateral defects received the calcium carbonate carrier combined with GTR without rhTGF‐β1 (control). The animals were euthanized at week 4 post‐surgery and block biopsies of the defect sites were collected for histologic and histometric analysis. Radiographs were obtained at defect creation and weeks 2 and 4 after defect creation.

Results: No statistically significant differences were observed in new bone formation (bone height and area) among the treatments. However, total residual carrier was significantly reduced in sites receiving rhTGF‐β1 compared to control (P = 0.04). Similarly, carrier density was considerably reduced in sites receiving rhTGF‐β1 compared to control; the difference was borderline statistically significant (P = 0.06).

Conclusion: Within the limitations of the study, it may be concluded that rhTGF‐β1 accelerates biodegradation of a particulate calcium carbonate biomaterial, indicating a biologic activity of the rhTGF‐β1 formulation apparently not encompassing enhanced or accelerated periodontal regeneration.
Coronally Positioned Flap for Treatment of Restored Root Surfaces: A 6‐Month Clinical Evaluation
Authors: Lucchesi Juliana Antico , Santos Vanessa Renata , Amaral Cristiane Mariote , Peruzzo Daiane Cristina , Duarte Poliana Mendes
Published: April 2007

Background: The aim of this study was to evaluate clinically the treatment of gingival recession associated with non‐carious cervical lesions (NCCLs) by resin modified glass ionomer cement (RMGI) or microfilled resin composite (MRC) and coronally positioned flap (CPF) at 6 months following surgery.

Methods: Fifty‐nine patients were assigned to one of three treatments: root exposure without NCCL treated with CPF (group 1); root exposure with NCCL treated with RMGI restoration plus CPF (group 2); or root exposure with NCCL treated with MRC restoration plus CPF (group 3). Clinical measurements that were assessed at baseline and at 3 and 6 months after surgery included plaque index (PI), bleeding on probing (BOP); probing depth (PD), recession reduction (RR), clinical attachment level gain (CALG), keratinized tissue height (KTH), keratinized tissue thickness (KTT), percentage of root coverage (RC), and percentage of restored root coverage (RRC).

Results: Intra‐ and intergroup analyses demonstrated no significant differences in PI, BOP, PD, RR, CALG, KTH, or KTT (P >0.05) among the groups at any time. At 6 months, the mean RC was 80.83% ± 21.08% for group 1; the mean RRCs were 71.99% ± 18.69% and 74.18% ± 15.02% for groups 2 and 3, respectively. There were no statistically significant differences in RRC between groups 2 and 3.

Conclusion: All treatments showed root coverage improvement without damage to periodontal tissues, supporting the use of CPF for treatment of root surfaces restored with RMGI or MRC as being effective over the 6‐month period.
Epidemiology of Osteoporosis
Authors: Cvijetić Selma , Grazio Simeon , Kaštelan Darko , Koršić Mirko
Published: April 2007

Epidemiologija Osteoporoze

U većini zemalja u svijetu, pa tako i u Hrvatskoj ne postoji jedinstveni sustav registriranja oboljelih od osteoporoze, kao ni osoba s osteoporotskim prijelomima. Podatci iz epidemioloških istraživanja pokazuju da je učestalost osteoporoze veća u azijskim zemljama u odnosu na europsko i sjevernoameričko stanovništvo bijele rase, u kojih prevalencija iznosi 10% do 15%. U Hrvatskoj je učestalost slična onoj u drugim europskim zemljama, dok je incidencija osteoporotskih prijeloma nešto veća od europskog prosjeka. Također je broj prijavljenih slučajeva osteoporoze i osteomalacije od primarne zdravstvene zaštite zadnjih 10 godina u stalnom porastu i u 2004. godini je iznosio 0,70% u odnosu na ukupan broj prijavljenih bolesti. Najvažniji rizični čimbenici bolesti su dob, naslijeđe, životne navike, postojanje kroničnih bolesti i hormonskih poremećaja te individualna fizikalna obilježja kosti. Kao u većine kroničnih bolesti, mjerama prevencije može se pravodobno spriječiti nastanak bolesti i njezinih komplikacija.
Glucocorticoid-Induced Osteoporosis
Authors: Čurković Božidar
Published: April 2007

Osteoporoza Uzrokovana Glukokortikoidima

Glukokortikoidi su lijekovi koji najčešće uzrokuju osteoporozu, a učinci tih lijekova pobuđuju sve veću pozornost zbog njihove raširene primjene u autoimunim, plućnim, gastrointestinalnim bolestima ili nakon transplantacije organa. Glukokortikoidna osteoporoza nastaje brzo, unutar nekoliko prvih mjeseci primjene glukokortikoida, više zahvaća spužvastu nego kortikalnu kost i brzo povećava rizik nastanka prijeloma, poglavito kralježaka i kuka. Učinci glukokortikoida na skelet ovisni su i o dozi i o trajanju terapije. Mehanizmi kojima glukokortikoidi dovode do osteoporoze su mnogobrojni i nisu još potpuno jasni. Usprkos postojanju više preporuka za otkrivanje i liječenje glukokortikoidne osteoporoze i lijekova koji mogu smanjiti rizik prijeloma kralježnice, još uvijek se razmjerno mali postotak bolesnika zadovoljavajuće dijagnosticira i liječi.
Layer‐by‐Layer Assembly of Silicotungstate Multilayer Films Modified on Glassy Carbon Electrode and Their Electrochemical Behaviors
Authors: Du Jinyan , Lv Guiqin , Hu Changwen , Wu Huaqiang
Published: April 2007

A new electrode was modified by multilayer films composed of heteropolyanion (SiW12) and cationic polymer poly(diallyldimethylammonium chloride) through electrochemical growth. The modified electrode electrochemical behavior, the effect of solution pH and electrocatalytic response to the reduction of BrO3‐ and NO2‐ have been investigated. The result shows that the electrochemical process of multilayer films modified electrode including SiW12 is a reversible process by electrochemical step. One‐electron process has no proton participation in the first step, and one‐electron process is accompanied by one proton participation in the second step and two‐electron process is accompanied by two protons participation in the third step. The films grow uniformly, and the peak currents increase with increasing layer numbers. The peak currents increase with scan rate, and the reduced potentials of multilayer films shift negatively with increasing pH. The electrochemical mechanism of multilayer films was suggested.
Dynamic Ultrasound‐Assisted Extraction of Catechins and Caffeine in Some Tea Samples
Authors: Gu Xungang , Cai Jibao , Zhang Zhengzhu , Su Qingde
Published: April 2007

A novel dynamic ultrasound‐assisted extraction (DUAE) device has been constructed for extraction of five catechins and caffeine in solid sample. The accurate, simple, reproducible and sensitive method for the determination of five catechins and caffeine has been developed and validated. A comparison has been made of the efficiencies by employing DUAE and conventionally static ultrasound‐assisted extraction (UAE). The proposed method can not only improve extraction efficiency but also decrease time and solvent consumption. The commercial Chinese tea samples, involving green and black teas, are rapidly analyzed by the proposed DUAE method. The linearity, range, selectivity, precision, accuracy, and robustness also showed acceptable values.
Platinum(II), Palladium(II), Rhodium(III) and Lead(II) Voltammetric Determination in Sites Differently Influenced by Vehicle Traffic
Authors: Melucci Dora , Locatelli Clinio
Published: April 2007

The present work reports analytical results relevant to voltammetric determination of Pt(II), Pd(II), Rh(III) [Platinum Group Metals (PGMs)] and Pb(II) in superficial water sampled in sites differently influenced by vehicle traffic, especially considering their temporal behaviour. For all the elements, in addition to detection limits, precision, expressed as relative standard deviation (sr %) and accuracy, expressed as percentage recovery (R %) are also reported. In all cases they show to be good, being the former lower than 6 % and the latter in the range 94‐105 %. A critical comparison with spectroscopic measurements is also discussed.
Heavy Metal Removal from Aqueous Solution by Pseudevernia Furfuracea (L.) Zopf
Authors: Ates Ayten , Yildiz Atilla , Yildiz Nuray , Calimli Ayla
Published: April 2007

The present study was carried out in a batch system using a lichen (Pseudevernia furfuracea (L.) Zopf) for the sorption of nickel(II) and copper(II) ions from water. Particularly, the effect of pH, contact time and temperature were considered. Pseudevernia furfuracea exhibited nickel(II) and copper(II) uptake of 49.87 and 60.83 mg/g at an initial pH of 4 and 5‐6 at 35 °C respectively. Both the Freundlich and Langmuir adsorption models were suitable for describing the biosorption of nickel(II) and copper(II) by the biosorbent. Biosorption showed pseudo first order rate kinetics for nickel and copper ions. Using the equilibrium constant values obtained at 25 and 35 °C, the thermodynamics properties of the biosorption (ΔG°, ΔH° and ΔS°) were determined. The biosorption of nickel(II) and copper(II) onto Pseudevernia furfuracea was found to be endothermic.
Enantioselektive Morita‐Baylis‐Hillman‐Reaktionen und ihre Aza‐Varianten
Authors: Masson Géraldine , Housseman Christopher , Zhu Jieping
Published: April 2007

Asymmetrische Morita‐Baylis‐Hillman(MBH)‐Reaktionen haben sich in den letzten Jahren parallel zum Konzept der difunktionellen Organokatalyse rasant weiterentwickelt. Während die Organokatalyse im Allgemeinen erst beginnt, bei einer Reihe wichtiger organischer Umwandlungen mit der Metallkatalyse zu konkurrieren, zählt die MBH‐Reaktion zu einer Gruppe prototypischer Reaktionen, für die organische Katalysatoren ihren metallhaltigen Analoga bereits jetzt überlegen sind. Dieser Kurzaufsatz gibt einen Überblick über neue mechanistische Erkenntnisse und Fortschritte bei der Synthese von niedermolekularen organischen Verbindungen für enantioselektive MBH‐ und Aza‐MBH‐Reaktionen.
Influence of annealing on conduction of high‐density polyethylene/carbon black composite
Authors: Song Yihu , Zheng Qiang
Published: April 2007

The high‐density polyethylene/carbon black (HDPE/CB) composite with a CB volume fraction of 0.113 is isothermally annealed at various temperatures from 116 to 149°C, covering the positive temperature coefficient (PTC) transition and the negative temperature coefficient regions during heating as well as from 149 to 122°C above the reverse‐PTC transition during cooling. Influences of annealing temperature on the resistance–temperature and the resistance–time characteristics are discussed. The results show that both the resistance‐temperature and the resistance‐time characteristics are highly sensitive to the thermal history. Effects of recrystallization of HDPE and redistribution of CB aggregates in HDPE on the performance are discussed. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Controlled release study of carbaryl insecticide from calcium alginate and nickel alginate hydrogel beads
Authors: Işıklan Nuran
Published: April 2007

In this study, controlled release formulations for reducing environmental impact of pesticides have been produced by encapsulating as a model pesticide carbaryl (Carb) in the alginate beads. The various hydrogel bead formulations were prepared by the ionotropic crosslinking of sodium alginate (NaAlg) with calcium and nickel ions. The surface morphology of prepared beads was characterized with scanning electron microscopy (SEM). SEM confirmed the spherical nature and surface morphology of the particles. Bead characteristics, such as carbaryl entrapment efficiency, particle size, equilibrium swelling degree, and carbaryl release kinetics, were determined. The effects of the bead preparation conditions such as crosslinker concentration and type, carbaryl/sodium alginate (Carb/NaAlg) ratio and percentage of NaAlg on the carbaryl release from the calcium alginate (Ca‐Alg) and nickel alginate (Ni‐Alg) beads were investigated in distilled water at 25°C. It was observed that carbaryl release from the Ca‐Alg beads was slower than that of Ni‐Alg beads. The release results indicated that carbaryl release from both of the Ca‐Alg and Ni‐Alg beads decreases with the increasing crosslinker concentration, Carb/NaAlg ratio and percentage of NaAlg. The highest carbaryl release was found to be 100% for the Ni‐Alg beads at 3 days whereas the lowest carbaryl release was found to be 67% for the Ca‐Alg beads at 21 days. The swelling measurements of the beads were also in consistent with the carbaryl release results. The carbaryl release from most of the bead formulations followed Case II transport. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Synthesis, characterization, and applications of novel additives of polysiloxane containing N,N′‐bis(diphenylsilyl)tetraphenylcyclodisilazane
Authors: Zhu Yangping , Guo Li , Zhang Zhijie , Xie Zemin , Xu Caihong
Published: April 2007

Three N,N′‐bis(diphenylsilyl)tetraphenylcyclodisilazane‐based derivatives, N,N′‐bis(3,3,3‐trimethyl‐1,1‐diphenyl‐disiloxanyl)tetraphenylcyclodisilazane, N‐(3,3‐dimethyl‐1,1‐diphenyl‐3‐vinyl‐disiloxanyl)‐N′‐(3,3,3‐trimethyl‐1,1‐diphenyl‐disiloxanyl)‐tetraphenylcyclodisilazane, and N,N′‐bis‐(3,3‐dimethyl‐1,1‐diphenyl‐3‐vinyl‐disiloxanyl) tetraphenylcyclodisilazane, were synthesized. These compounds were synthesized in an easy and effective route. X‐ray single‐crystal diffraction analyses showed that the four‐member rings were planar rings, and the structures are different with the different substitution. The compound N,N′‐bis‐(3,3‐dimethyl‐1,1‐diphenyl‐3‐vinyl‐disiloxanyl) tetraphenylcyclodisilazane was added to the silicone rubber as additive to enhance the thermal stability greatly increased the thermal stability of the silicone rubber, without altering the glass transition temperature. The weight loss at 350°C in nitrogen atmosphere for 24 h reduced from 55.8% for 0 wt % to 9.8% for 10 wt % addition N,N′‐Bis‐(3,3‐dimethyl‐1,1‐diphenyl‐3‐vinyl‐disiloxanyl)tetraphenylcyclodisilazane. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007