bluuebunny/crossref_metadata_2025_split huggingface dataset:
Activins and their receptors in female reproduction
Authors: Peng Chun , Mukai Spencer T 
Published: April 2011

Activins are growth and differentiation factors belonging to the transforming growth factor-β superfamily. They are dimeric proteins consisting of two inhibin β subunits. The structure of activins is highly conserved during vertebrate evolution. Activins signal through type I and type II receptor proteins, both of which are serine/threonine kinases. Subsequently, downstream signals such as Smad proteins are phosphorylated. Activins and their receptors are present in many tissues of mammals and lower vertebrates where they function as autocrine and (or) paracrine regulators of a variety of physiological processes, including reproduction. In the hypothalamus, activins are thought to stimulate the release of gonadotropin-releasing hormone. In the pituitary, activins increase follicle-stimulating hormone secretion and up-regulate gonadotropin-releasing hormone receptor expression. In the ovaries of vertebrates, activins are expressed predominantly in the follicular layer of the oocyte where they regulate processes such as folliculogenesis, steroid hormone production, and oocyte maturation. During pregnancy, activin-A is also involved in the regulation of placental functions. This review provides a brief overview of activins and their receptors, including their structures, expression, and functions in the female reproductive axis as well as in the placenta. Special effort is made to compare activins and their receptors in different vertebrates.Key words: activins, activin receptors, reproductive axis, placenta.
Stress-relaxation and contraction of a collagen matrix induces expression of TGF-β and triggers apoptosis in dermal fibroblasts
Authors: Varedi M , Tredget E E , Ghahary A , Scott P G 
Published: April 2011

Extracellular matrix serves as a scaffold for cells and can also regulate gene expression and ultimately cell behaviour. In this study, we compared the effects of three forms of type I collagen matrix, which differed only in their mechanical properties, and plastic on the expression of transforming growth factor-β1 (TGF-β1), matrix metalloproteinase-1 (collagenase), and type I collagen and on the growth and survival of human dermal fibroblasts. These effects were correlated with alterations in cell morphology and organization of intracellular actin. Cells in detached or stress-relaxed matrices were spherical, lacked stress fibres, and showed increased TGF-β1 mRNA compared to the cells in anchored collagen matrices or on plastic, which were polygonal or bipolar and formed stress fibres. The levels of TGF-β measured by bioassay were higher in detached and stress-relaxed collagen matrices, than in anchored collagen matrices. Cells on plastic contained little or no immunoreactive TGF-β, while most cells in collagen matrices were stained. The levels of collagenase mRNA were significantly higher in all the collagen matrix cultures compared to those on plastic, but there were no statistically significant differences between them. Levels of mRNA for procollagen type I were not significantly affected by culture in the collagen matrices. Apoptotic fibroblasts were detected by the TUNEL assay in detached (5.7%) and to a lesser extent in stress-relaxed (2.2%) matrices, but none were observed in anchored collagen matrices or on plastic. These results show that alterations in the mechanical properties of matrix can induce the expression of TGF-β and trigger apoptosis in dermal fibroblasts. They further suggest that inability to reorganize this matrix could be responsible for the maintenance of the fibroproliferative phenotype associated with fibroblasts in hypertrophic scarring.Key words: transforming growth factor-β, apoptosis, fibroblasts.
Field quality control of an earth dam: random versus purposive sampling
Authors: Kotzias P C , Stamatopoulos A C 
Published: April 2011

There are two sampling operations for field quality control of an earth dam: the random and the purposive. Both have been well established by their long use in engineering projects, but are fundamentally different in their basic assumptions, approach, and interpretation of results. They are analyzed herein and their basic similarities and differences are compared. The intent is to provide the proper perspective for an objective selection and subsequent implementation of one or the other operation. It is concluded that both operations can be implemented, singly or jointly, on a project, provided that inherent potentialities and limitations are clearly recognized and evaluated throughout design and construction. Key words: earth dam, rockfill, sampling, statistical analysis, quality control, quality assurance.
Vessel Wall Inflammation in Spontaneous Cervical Artery Dissection
Authors: Pfefferkorn Thomas , Saam Tobias , Rominger Axel , Habs Maximilian , Gerdes Lisa-Ann , Schmidt Caroline , Cyran Clemens , Straube Andreas , Linn Jennifer , Nikolaou Konstantin , Bartenstein Peter , Reiser Maximilian , Hacker Marcus , Dichgans Martin 
Published: April 2011

Background and Purpose—
Vessel wall inflammation (VWI) may be a pathogenetic factor in cervical artery dissection (CAD). We used contrast-enhanced high-resolution MRI (hrMRI) and positron emission tomography CT (PET-CT) to systematically investigate VWI in spontaneous CAD.

Methods—
In this monocentric, prospective, observational study, all consecutive patients with acute, MRI-confirmed, spontaneous CAD admitted to our center between August 2007 and August 2009 were included. VWI was defined as perivascular contrast enhancement in hrMRI and increased perivascular [18F]-fluorodesoxyglucose uptake in PET-CT. VWI was further differentiated between local (restricted to the site of dissection) and generalized (exceeding the site of dissection).

Results—

A total of 37 patients were included. Multiple dissections were seen in 10 patients (27%). Twenty-five patients received both modalities as planned, 8 received only PET-CT, and 4 received only hrMRI. A subset of patients showed signs of a generalized VWI in hrMRI (4/29 patients, 14%) and PET-CT (8/33 patients, 24%). In patients who received both modalities, all with hrMRI signs of generalized VWI were PET-CT positive (3/3), whereas some PET-CT–positive patients were hrMRI-negative (4/7). If present, generalized VWI in hrMRI completely resolved within 6 months. The presence of >2 simultaneous dissections (seen in 2 patients) was significantly associated with generalized VWI in hrMRI (
P
=0.015) but marginally not in PET-CT (
P
=0.053).

Conclusions—
A subset of patients with spontaneous CAD showed signs of a generalized transient inflammatory arteriopathy in contrast-enhanced hrMRI and PET-CT. This subset of patients may be more prone to multiple dissections.
Dietary Intakes of Antioxidant Vitamins and Mortality From Cardiovascular Disease
Authors: Kubota Yoshimi , Iso Hiroyasu , Date Chigusa , Kikuchi Shogo , Watanabe Yoshiyuki , Wada Yasuhiko , Inaba Yutaka , Tamakoshi Akiko ,   the JACC Study Group
Published: April 2011

Background and Purpose—
Only a few reports have dealt with the association of antioxidant vitamin intakes with mortality or morbidity from cardiovascular disease in Asia. We investigated the relation of dietary vitamins A, E, and C intake with mortality from cardiovascular disease for Japanese men and women.

Methods—
The subjects were 23 119 men and 35 611 women aged 40 to 79 years without a history of cardiovascular disease or cancer who responded to the food frequency questionnaire as part of the Japan Collaborative Cohort Study for Cancer Risk (JACC) Study. They were followed up for a median period of 16.5 years. Hazard ratios were calculated per quintile of dietary vitamins A, E, and C intake by using Cox proportional hazard model.

Results—
During the 859 962 person-year follow-up, there were 2690 deaths (1343 men and 1347 women) from cardiovascular disease, comprising 1227 (607 men and 620 women) from stroke and 557 (311 men and 246 women) from coronary heart disease. The multivariable hazard ratios (95% CI) associated with the highest versus lowest quintiles of vitamin C intake were 0.70 (0.54 to 0.92) for total stroke, 0.63 (0.41 to 0.97) for coronary heart disease, and 0.79 (0.66 to 0.94) for total cardiovascular disease for women, but the inverse associations observed were weak and did not reach statistical significance for men. No significant association was observed between vitamins A or E intake and risk of mortality for either men or women.

Conclusions—
Vitamin C intake is inversely associated with mortality from cardiovascular disease for Japanese women.
Association With Serum Gamma-Glutamyltransferase Levels and Alcohol Consumption on Stroke and Coronary Artery Disease
Authors: Higashiyama Aya , Wakabayashi Ichiro , Ono Yuu , Watanabe Makoto , Kokubo Yoshihiro , Okayama Akira , Miyamoto Yoshihiro , Okamura Tomonori 
Published: April 2011

Background and Purpose—
Light-to-moderate alcohol consumption is associated with reduced risk for cardiovascular disease, whereas high serum γ-glutamyltransferase (GGT) level is associated with cardiovascular disease. However, whether light-to-moderate alcohol drinking is still related to reduced risk of cardiovascular disease irrespective of GGT level is uncertain.

Methods—
We performed a 12.5-year cohort study of 2336 men (excluding exdrinkers) who were free from cardiovascular disease. They were classified into 4 groups according to alcohol consumption: never, and current light, moderate, or heavy drinker. The multivariate-adjusted hazard ratios of alcohol consumption for incidence of coronary artery disease, total stroke, and ischemic stroke compared with those of never drinkers were assessed with stratification by GGT median (32 IU/L).

Results—
In participants with GGT >32 IU/L, the hazard ratios of all current drinkers for total and ischemic stroke were higher than those of never drinkers. However, in all current drinkers with GGT ≤32 IU/L, the multivariate-adjusted hazard ratios for total and ischemic stroke were lower than in never drinkers.

Conclusions—
In men with above GGT median, alcohol drinking even with light-to-moderate consumption could be a risk factor for ischemic stroke.
“It’s a Wild Thing, Waiting to Get Me”: Stance Analysis of African Americans With Diabetes
Authors: Davis Boyd H. , Pope Charlene , Mason Peyton R. , Magwood Gayenell , Jenkins Carolyn M. 
Published: April 2011

Purpose This mixed methods study uses a unique approach from social science and linguistics methodologies, a combination of positioning theory and stance analysis, to examine how 20 African Americans with type 2 diabetes make sense of the practices that led to recurrent emergency department visits to identify needs for more effective intervention. Methods In a purposive sample of postemergency department visit interviews with a same-race interviewer, people responded to open-ended questions reflecting on the decision to seek emergency department care. As applied to diabetes education, positioning theory explains that people use their language to position themselves toward their disease, their medications, and the changes in their lives. Transcriptions were coded using discourse analysis to categorize themes. As a form of triangulation, stance analysis measured language patterns using factor analysis to see when and how speakers revealed affect, attitude, and agentive choices for action. Conclusion Final analysis revealed that one third of the sample exhibited high scores for positive agency or capacity for decision-making and self-management, while the rest expressed less control and more negative emotions and fears that may preclude self-management. This approach suggests a means to tailor diabetes education considering alternative approaches focused on communication for those facing barriers.
The “Ligamentization” Process in Anterior Cruciate Ligament Reconstruction
Authors: Claes Steven , Verdonk Peter , Forsyth Ramses , Bellemans Johan 
Published: April 2011

Background: Surgical anterior cruciate ligament reconstruction using tendon grafts has become the standard to treat the functionally unstable anterior cruciate ligament–deficient knee. Although tendons clearly differ biologically from ligaments, multiple animal studies have shown that the implanted tendons indeed seem to remodel into a ligamentous “anterior cruciate ligament–like” structure. Purpose: The goal of this study was to systematically review the current literature on the “ligamentization” process in human anterior cruciate ligament reconstruction. Study Design: Systematic review. Methods: A computerized search using relevant search terms was performed in the PubMed, MEDLINE, EMBASE, and Cochrane Library databases, as well as a manual search of reference lists. Searches were limited to studies examining the healing of the intra-articular portion of the tendon graft based on biopsies of this graft obtained from a living human. Results: Four studies were determined to be appropriate for systematic review, none of them reaching a level of evidence higher than 3. All reports considered autografts. Biopsy specimens were evaluated by light or electron microscopy and analyzed for vascularization, cellular aspects, and appearance of extracellular matrix. All authors universally agreed that the tendon grafts survive in the intra-articular environment. Based on changes observed in the healing grafts with regard to vascularization, cellular aspects, and properties of the extracellular matrix, different chronologic stages in the ligamentization process were discerned. Conclusion: The key finding of this systematic review is that a free tendon graft replacing a ruptured human anterior cruciate ligament undergoes a series of biologic processes termed “ligamentization.” The graft seems to remain viable at any time during this course. Histologically, the mature grafts may resemble the normal human anterior cruciate ligament, but ultrastructural differences regarding collagen fibril distribution do persist. Different stages of the ligamentization process are described, but no agreement exists on their time frame. Problematic direct transmission of animal data to the human situation, the limited number of reports considering the ligamentization process in humans, and the potential biopsy sampling error attributable to superficial graft biopsies necessitate further human studies on anterior cruciate ligament graft ligamentization.
Mechanisms of Anterior Cruciate Ligament Injury in World Cup Alpine Skiing
Authors: Bere Tone , Flørenes Tonje Wåle , Krosshaug Tron , Koga Hideyuki , Nordsletten Lars , Irving Christopher , Muller Erich , Reid Robert Cortas , Senner Veit , Bahr Roald 
Published: April 2011

Background: There is limited insight into the mechanisms of anterior cruciate ligament injuries in alpine skiing, particularly among professional ski racers. Purpose: This study was undertaken to qualitatively describe the mechanisms of anterior cruciate ligament injury in World Cup alpine skiing. Study Design: Case series; Level of evidence, 4. Methods: Twenty cases of anterior cruciate ligament injuries reported through the International Ski Federation Injury Surveillance System for 3 consecutive World Cup seasons (2006-2009) were obtained on video. Seven international experts in the field of skiing biomechanics and sports medicine related to alpine skiing performed visual analyses of each case to describe the injury mechanisms in detail (skiing situation, skier behavior, biomechanical characteristics). Results: Three main categories of injury mechanisms were identified: slip-catch, landing back-weighted, and dynamic snowplow. The slip-catch mechanism accounted for half of the cases (n = 10), and all these injuries occurred during turning, without or before falling. The skier lost pressure on the outer ski, and while extending the outer knee to regain grip, the inside edge of the outer ski caught abruptly in the snow, forcing the knee into internal rotation and valgus. The same loading pattern was observed for the dynamic snowplow (n = 3). The landing back-weighted category included cases (n = 4) where the skier was out of balance backward in flight after a jump and landed on the ski tails with nearly extended knees. The suggested loading mechanism was a combination of tibiofemoral compression, boot-induced anterior drawer, and quadriceps anterior drawer. Conclusion: Based on this video analysis of 20 injury situations, the main mechanism of anterior cruciate ligament injury in World Cup alpine skiing appeared to be a slip-catch situation where the outer ski catches the inside edge, forcing the outer knee into internal rotation and valgus. A similar loading pattern was observed for the dynamic snowplow. Injury prevention efforts should focus on the slip-catch mechanism and the dynamic snowplow.
Distribution and characterization of ampicillin- and tetracycline-resistant Escherichia colifrom feedlot cattle fed subtherapeutic antimicrobials
Authors: Mirzaagha Parasto , Louie Marie , Sharma Ranjana , Yanke L Jay , Topp Ed , McAllister Tim A 
Published: April 2011

Abstract

Background
Feedlot cattle in North America are routinely fed subtherapeutic levels of antimicrobials to prevent disease and improve the efficiency of growth. This practice has been shown to promote antimicrobial resistance (AMR) in subpopulations of intestinal microflora including Escherichia coli. To date, studies of AMR in feedlot production settings have rarely employed selective isolation, therefore yielding too few AMR isolates to enable characterization of the emergence and nature of AMR in E. coli as an indicator bacterium. E. coli isolates (n = 531) were recovered from 140 cattle that were housed (10 animals/pen) in 14 pens and received no dietary antimicrobials (control - 5 pens, CON), or were intermittently administered subtherapeutic levels of chlortetracycline (5 pens-T), chlortetracycline + sulfamethazine (4 pens-TS), or virginiamycin (5 pens-V) for two separate periods over a 9-month feeding period. Phenotype and genotype of the isolates were determined by susceptibility testing and pulsed field gel electrophoresis and distribution of characterized isolates among housed cattle reported. It was hypothesized that the feeding of subtherapeutic antibiotics would increase the isolation of distinct genotypes of AMR E. coli from cattle.

Results
Overall, patterns of antimicrobial resistance expressed by E. coli isolates did not change among diet groups (CON vs. antibiotic treatments), however; isolates obtained on selective plates (i.e., MA,MT), exhibited multi-resistance to sulfamethoxazole and chloramphenicol more frequently when obtained from TS-fed steers than from other treatments. Antibiograms and PFGE patterns suggested that AMR E. coli were readily transferred among steers within pens. Most MT isolates possessed the tet(B) efflux gene (58.2, 53.5, 40.8, and 50.6% of isolates from CON, T, TS, and V steers, respectively) whereas among the MA (ampicillin-resistant) isolates, the tem1-like determinant was predominant (occurring in 50, 66.7, 80.3, and 100% of isolates from CON, T, TS, and V steers, respectively).

Conclusions
Factors other than, or in addition to subtherapeutic administration of antibiotics influence the establishment and transmission of AMR E. coli among feedlot cattle.
Mycobacterium tuberculosis septum site determining protein, Ssd encoded by rv3660c, promotes filamentation and elicits an alternative metabolic and dormancy stress response
Authors: England Kathleen , Crew Rebecca , Slayden Richard A 
Published: April 2011

Abstract

Background
Proteins that are involved in regulation of cell division and cell cycle progression remain undefined in Mycobacterium tuberculosis. In addition, there is a growing appreciation that regulation of cell replication at the point of division is important in establishing a non-replicating persistent state. Accordingly, the objective of this study was to use a systematic approach consisting of consensus-modeling bioinformatics, ultrastructural analysis, and transcriptional mapping to identify septum regulatory proteins that participate in adaptive metabolic responses in M. tuberculosis.

Results
Septum site determining protein (Ssd), encoded by rv3660c was discovered to be an ortholog of septum site regulating proteins in actinobacteria by bioinformatics analysis. Increased expression of ssd in M. smegmatis and M. tuberculosis inhibited septum formation resulting in elongated cells devoid of septa. Transcriptional mapping in M. tuberculosis showed that increased ssd expression elicited a unique response including the dormancy regulon and alternative sigma factors that are thought to play a role in adaptive metabolism. Disruption of rv3660c by transposon insertion negated the unique transcriptional response and led to a reduced bacterial length.

Conclusions
This study establishes the first connection between a septum regulatory protein and induction of alternative metabolism consisting of alternative sigma factors and the dormancy regulon that is associated with establishing a non-replicating persistent intracellular lifestyle. The identification of a regulatory component involved in cell cycle regulation linked to the dormancy response, whether directly or indirectly, provides a foundation for additional studies and furthers our understanding of the complex mechanisms involved in establishing a non-replicating state and resumption of growth.
Improved antiretroviral treatment outcome in a rural African setting is associated with cART initiation at higher CD4 cell counts and better general health condition
Authors: Mossdorf Erik , Stoeckle Marcel , Mwaigomole Emmanuel G , Chiweka Evarist , Kibatala Patience L , Geubbels Eveline , Urassa Honoraty , Abdulla Salim , Elzi Luigia , Tanner Marcel , Furrer Hansjakob , Hatz Christoph , Battegay Manuel 
Published: April 2011

AbstractBackgroundData on combination antiretroviral therapy (cART) in remote rural African regions is increasing.MethodsWe assessed prospectively initial cART in HIV-infected adults treated from 2005 to 2008 at St. Francis Designated District Hospital, Ifakara, Tanzania. Adherence was assisted by personal adherence supporters. We estimated risk factors of death or loss to follow-up by Cox regression during the first 12 months of cART.ResultsOverall, 1,463 individuals initiated cART, which was nevirapine-based in 84.6%. The median age was 40 years (IQR 34-47), 35.4% were males, 7.6% had proven tuberculosis. Median CD4 cell count was 131 cells/μl and 24.8% had WHO stage 4. Median CD4 cell count increased by 61 and 130 cells/μl after 6 and 12 months, respectively. 215 (14.7%) patients modified their treatment, mostly due to toxicity (56%), in particular polyneuropathy and anemia. Overall, 129 patients died (8.8%) and 189 (12.9%) were lost to follow-up. In a multivariate analysis, low CD4 cells at starting cART were associated with poorer survival and loss to follow-up (HR 1.77, 95% CI 1.15-2.75, p = 0.009; for CD4 <50 compared to >100 cells/μl). Higher weight was strongly associated with better survival (HR 0.63, 95% CI 0.51-0.76, p < 0.001 per 10 kg increase).ConclusionscART initiation at higher CD4 cell counts and better general health condition reduces HIV related mortality in a rural African setting. Efforts must be made to promote earlier HIV diagnosis to start cART timely. More research is needed to evaluate effective strategies to follow cART at a peripheral level with limited technical possibilities.