bluuebunny/crossref_metadata_2025_split huggingface dataset:
Window‐period human immunodeficiency virus transmission to two recipients by an adolescent blood donor
Authors: Phelps Ruby , Robbins Kenneth , Liberti Thomas , Machuca Ana , Leparc German , Chamberland Mary , Kalish Marcia , Hewlett Indira , Folks Thomas , Lee Lisa M. , McKenna Matthew 
Published: May 2004

BACKGROUND:  Pooled NAT and donor screening have reduced the diagnostic window period for HIV in the blood donor population to approximately 10 to 15 days. This report describes two cases of transfusion‐acquired HIV infection and verification of transmission from the donor to the recipients, and attempts to identify how the 18‐year‐old donor acquired her infection.STUDY DESIGN AND METHODS:  After a repeat donor had a positive HIV test result, two recipients of the donor's previous donation were identified and tested. The donor and recipients were interviewed and blood samples were obtained for HIV DNA sequencing and phylogenetic analysis.RESULTS:  The two recipients had positive HIV test results. Phylogenetic analysis showed a high genetic similarity among the viruses (bootstrap 100%), consistent with transmission from the donor to the recipients. Four of five men with whom the donor had sexual contact during the critical time period when infection most likely occurred were located and tested; results were negative for HIV.CONCLUSIONS:  Pooled NAT of blood donations has not eliminated the window period for HIV identification during seroconversion.
A new automated cell washer device for thawed cord blood units
Authors: Perotti Cesare G. , Fante Claudia Del , Viarengo Gianluca , Papa Pietro , Rocchi Loretta , Bergamaschi Paola , Bellotti Laura , Marchesi Andrea , Salvaneschi Laura 
Published: May 2004

BACKGROUND:  The current available techniques to wash out DMSO from thawed umbilical cord blood (UCB) units are based essentially on standard centrifugation in an open system with various degrees of cell loss.STUDY DESIGN AND METHODS:  We evaluated the capacity of a new automated closed device (Cytomate, Baxter, IL) to wash out the DMSO from thawed UCB units, saving at the same time the progenitor and accessory cells in terms of CD34+ cells and MNCs. We modified the standard software of the device and calculated the cell recovery on 25 UCB units. Moreover, we set up a new gas chromatographic method to exactly detect the DMSO removal rate.RESULTS:  To evaluate the efficiency of the Cytomate device, we considered the postthawing (prewashing) versus postwashing cell recovery. The average recovery (%) in terms of total nucleated cells was 63.30 (range, 40.12‐89.00), CD34+ cells was 70.20 (range, 11.51‐89.01), CD3+ cells was 61.01 (range, 28.80‐87.08), CD4+ cells was 62.53 (range, 30.62‐96.73), CD8+ cells was 57.4 (range, 26.87‐94.72), CD19+ cells was 63.33 (range, 39.10‐90.33), CD16+/56+ cells was 70.67 (range, 8.91‐98.40), CFU‐GM was 74.33 (range, 20.23‐98.60), total CFUs was 82.34 (range, 14.83‐247.12), and viability was 89.67(range, 70.74‐98.30). The total working time required was, on average, 15 minutes (range, 7‐20).CONCLUSIONS:  The Cytomate device demonstrated a satisfying efficiency in cell recovery and in maintaining the clonogenic power of the UCB graft. The removal rate of DMSO was practically complete with evident advantages for the recipient. Finally, the entire manipulation performed in a closed system revealed to be safe, maintaining the sterility of the graft.
Possible association between different congenital abnormalities and use of different sulfonamides during pregnancy
Authors: Czeizel Andrew E. , Puhó Erzsébet , T. Sørensen Henrik , Olsen Jørn 
Published: May 2004

ABSTRACT  The objective of the study presented here was to check the debated human teratogenic potential of sulfonamide drugs. Five different sulfonamides such as sulfamethazine, sulfathiourea, sulfamethoxypyridazine, sulfamethoxydiazine and the combination of sulfamethazine‐sulfathiourea‐sulfamethoxypyridazine were differentiated.Cases with congenital abnormalities were compared with their matched controls without congenital abnormalities in the population‐based large data set of the Hungarian Case‐Control Surveillance of Congenital Abnormalities between 1980 and 1996.Of 38 151 newborn infants without any congenital abnormalities (control group), 163 (0.4%) had mothers who were treated with the sulfonamides studied during pregnancy, while of 22 843 cases with congenital abnormalities, 140 (0.6%) had mothers who were treated with the sulfonamides studied during pregnancy. The analysis of cases and matched controls indicated a higher rate of cardiovascular malformation (adjusted prevalence odds ratios [POR] with 95% CI: 3.5, 1.9–6.4) and clubfoot (adjusted POR with 95% CI: 2.6, 1.1–6.2) in infants born to mothers with sulfonamide treatment in the second and third months of pregnancy. The detailed analysis of different sulfonamides showed a possible association between cardiovascular malformations (adjusted POR with 95%; CI: 6.5, 2.6–15.9), particularly ventricular septal defect (17.1, 1.3–141.1) and sulfamethoxydiazine during the second and third months of pregnancy. In addition, a possible association was found between clubfoot and sulfathiourea, both during the entire pregnancy (adjusted POR with 95% CI: 2.3, 1.2–4.3) and in the second and third months of gestation (3.9, 1.1–13.8).Thus, maternal treatment of sulfamethoxydiazine may cause ventricular septal defect, while sulfathiourea may induce clubfoot; however, further studies are needed to verify or reject these associations.
Anti-GPVI–associated ITP: an acquired platelet disorder caused by autoantibody-mediated clearance of the GPVI/FcRγ-chain complex from the human platelet surface
Authors: Boylan Brian , Chen Hong , Rathore Vipul , Paddock Cathy , Salacz Michael , Friedman Kenneth D. , Curtis Brian R. , Stapleton Michelle , Newman Debra K. , Kahn Mark L. , Newman Peter J. 
Published: May 2004

Abstract
Platelet glycoprotein (GP) VI is a 62-kDa membrane glycoprotein that exists on both human and murine platelets in a noncovalent complex with the Fc receptor (FcR) γ chain. The GPVI/FcRγ-chain complex serves as the major activating receptor for collagen, as evidenced by observations that platelets genetically deficient in GPVI or the FcRγ chain are highly refractory to collagen-induced platelet activation. Recently, several different rat anti–murine GPVI monoclonal antibodies, termed JAQs 1, 2, and 3, were produced that had the unique property of “immunodepleting” GPVI from the murine platelet surface and rendering it unresponsive to collagen or GPVI-specific agonists like convulxin or collagen-related peptide (CRP). Herein, we describe a patient with a mild bleeding disorder and a moderately reduced platelet count whose platelets fail to become activated in response to collagen or CRP and inefficiently adhere to and form thrombi on immobilized collagen under conditions of arterial shear. Although the amount of GPVI platelet mRNA and the nucleotide sequence of the GPVI gene were found to be normal, both GPVI and the FcRγ chain were nearly absent from the platelet surface and were markedly reduced in wholeplatelet detergent lysates. Patient plasma contained an autoantibody that bound specifically to GPVI-positive, normal platelets, and cleared soluble GPVI from the plasma, suggesting that the patient suffers from a rare form of idiopathic thrombocytopenic purpura caused by a GPVI-specific autoantibody that mediates clearance of the GPVI/FcRγ-chain complex from the platelet surface. Since antibody-induced GPVI shedding now has been demonstrated in both humans and mice, these studies may provide a rationale for developing therapeutic reagents that induce temporary depletion of GPVI for the treatment of clinical thrombosis.
Maximizing power and minimizing treatment failures in clinical trials
Authors: Rosenberger William F , Hu Feifang 
Published: May 2004

Background Response-adaptive randomization procedures have a long history in the theoretical statistics literature over the past four decades. The main idea historically was to develop randomization procedures that place fewer patients on the inferior treatment. More recent research has changed the main focus to that of usual considerations in typical clinical trials: power, sample size, expected treatment failures, maintaining randomization, among others. Methods We describe response-adaptive randomization procedures for simple clinical trials comparing two binomial success probabilities, including the randomized play-the-winner rule, the drop-the-loser rule, and a modification of the doubly-adaptive biased coin design. We treat as our principal goal minimizing expected treatment failures while preserving power and randomization. Based on some recent theoretical literature [1,8,14], the basic guidelines for selecting an appropriate procedure include targeting optimal allocation, having small variability, and preserving randomization. We use simulation to compare power and expected treatment failures according to these guidelines. Results When the two treatments had high probabilities (>0.5) of success, the randomized play-the-winner rule was less powerful than complete randomization and the drop-the-loser rule by 1–3 percent with slightly larger expected number of treatment failures than the drop-the-loser rule. For all the success probabilities we examined, the drop-the-loser rule was within 1 percent of the power of complete randomization with a modest reduction of treatment failures. The doubly-adaptive biased coin design was as powerful or slightly more powerful than complete randomization in every case and expected treatment failures were always less, with modest reductions of the order of 0.3 percent to 8.3 percent. Conclusions We conclude that the drop-the-loser rule and a modification of the doubly-adaptive biased coin design are the preferred procedures, and simulations show that these procedures yield a modest reduction in expected treatment failures while preserving power over complete randomization.
Equipoise: a case study of the views of clinicians involved in two neonatal trials
Authors: Garcia Jo , Elbourne Diana , Snowdon Claire 
Published: May 2004

Background It is considered to be a fundamental ethical premise of human experimentation, that it should be carried out only where the effects of an intervention are unclear. The point at which it is considered that there is insufficient scientific and medical evidence to clearly state the superiority of an intervention has been termed equipoise. This concept has been the subject of much recent impassioned debate but little empirical research about the views of people involved in recruitment to randomized controlled trials (RCTs), and none in the particularly emotive area of neonatal intensive care. Methods Thirty neonatologists recruiting into one or both of two neonatal RCTs in five centres in England were interviewed using a semi-structured schedule to explore their involvement in randomised trials. The interviews were tape-recorded and transcribed. Equipoise was one among a range of topics covered. Concepts relating to equipoise were identified by close reading of the entire interviews. Themes emerging from the data were noted in their contexts then discussed between the coauthors. Interviewees also completed a brief questionnaire about their demographic background, and their experience of research and RCTs. Results Almost all the neonatologists used the concept of equipoise [using words and phrases such as uncertainty, lack of knowledge (or ignorance), strengths of views, and balancing of pros and cons] in their interview and, for most of them, equipoise seemed to be a useful term. They explored ideas about equipoise at the individual and community levels, and some linked equipoise with notions of the responsibility that should be exercised by the scientific and professional communities. They differed in the importance they gave to individual equipoise, and in how they reacted to threats to equipoise. Feelings of doubt about a trial and disturbed equipoise were more often expressed by more junior doctors. Conclusions Our findings suggest that the concept of equipoise goes beyond the idea of uncertainty. In part this is because it includes the balancing of benefit and harm; this balancing is part of a professional obligation and requires engagement with ‘expert’ knowledge. Equipoise could therefore be seen as ‘active’ or ‘responsible’ uncertainty. Elucidation of this difficult concept may help to facilitate recruitment for both clinicians and parents in future trials and thereby help to find answers to important clinical questions.
Environmental influence on testicular MAP kinase (ERK1) activity in the frogRana esculenta
Authors: Chieffi Paolo , Minucci Sergio 
Published: May 2004

SUMMARYRecent studies suggest a role for ERK1 in the regulation of spermatogonial proliferation. In this report the frog Rana esculenta, a seasonal breeder, was used as a model to study the possible effect on ERK1 of photoperiod and temperature. Adult male R. esculenta were subjected to several combinations of light and temperature at different times of the year to elucidate the regulation of ERK1 testicular activity in the spermatogonial proliferation by these environmental factors.Western blot analysis shows that under controlled experimental conditions an increase of temperature and photoperiod in November, characterized by a decrease in primary spermatogonial mitosis, induces ERK1 activity and spermatogonial proliferation, as confirmed using the proliferating cellular nuclear antigen (PCNA) as an early molecular marker. In contrast, a decrease in temperature and photoperiod in March, with an increase of primary spermatogonial mitosis, impairs ERK1 activity and spermatogonial proliferation.In conclusion, our data clearly show for the first time in a non-mammalian vertebrate that the temperature and the photoperiod exert a role in the spermatogonial proliferation via ERK1 activity.
The stability of telomereless chromosome fragments in adult androgenetic rainbow trout
Authors: Ocalewicz K. , Babiak I. , Dobosz S. , Nowaczyk J. , Goryczko K. 
Published: May 2004

SUMMARY
The study provides new data on the stability of gamma radiation-induced chromosome fragments of a putative maternal nuclear genome in an androgenetic vertebrate, rainbow trout (Oncorhynchus mykiss Walbaum). The fragments were found in five of 16 examined individuals and they were mostly centromeric parts of metacentric or subtelocentric chromosomes. Chromosome fragments were identical in all cells of a given androgenetic individual,indicating that segregation of chromosome fragments is active from the early cell divisions. Most of the fragments were telomereless, i.e. they had no telomeric sequences on their ends. This shows that telomeres are not necessary for stability of chromosomal structures in a vertebrate genome. In one individual, the interstitial telomeric sites were found in chromosomes, which could be the effect of joining chromosome fragments.
Social responses without early experience: Australian brush-turkey chicks use specific visual cues to aggregate with conspecifics
Authors: Göth Ann , Evans Christopher S. 
Published: May 2004

SUMMARY
Almost all birds depend upon early experience with adults and siblings to learn recognition cues. Megapodes, such as the Australian brush-turkey(Alectura lathami), have evolved a very different life history. Eggs are incubated in mounds of decaying organic material. Chicks hatch asynchronously and receive no parental care, so imprinting cannot occur. Nevertheless, chicks subsequently form groups with similar-aged conspecifics. We explored the perceptual basis of this aggregation response, focussing on likely visual cues, such as pecking movements and body colour. Experiments were conducted under naturalistic conditions in a large aviary, using realistic robot models and colour filters. The robots successfully evoked a range of social responses resembling those of a live companion. Aggregation depended upon both behaviour and morphology. Simultaneous choice tests revealed that brush-turkey chicks preferred a pecking robot over either a static model or a scanning robot, suggesting that responsiveness depends upon particular movement patterns. In addition, chicks were sensitive to changes in appearance but only those that affected radiance at short wavelengths. The mechanism underlying social aggregation after hatching hence involves relatively specific cues. This perceptual bias seems to be largely experience independent and may exploit attributes to which potential predators are insensitive.
Negative effects of early developmental stress on yolk testosterone levels in a passerine bird
Authors: Gil Diego , Heim Claudia , Bulmer Elena , Rocha Milagros , Puerta Marisa , Naguib Marc 
Published: May 2004

SUMMARYFemale birds incorporate in the yolks of their eggs significant concentrations of a number of different androgens. Yolk androgen has been shown to positively affect several fitness components at the embryo, nestling and juvenile stages. Previous experiments have shown that females lay eggs with higher androgen concentrations when they are paired with highly ornamented males. This pattern suggests that yolk androgens are costly to females. In this study, we experimentally manipulated adult female condition in zebra finches Taeniopygia guttata by modifying the level of developmental stress they suffered as nestlings. This was achieved by cross-fostering nestlings to broods of varying brood size. Subsequently, we measured the yolk testosterone contents of the female offspring that resulted from the experimental manipulation. As predicted, females deposited decreasing concentrations of testosterone with increasing brood sizes experienced as nestlings: testosterone concentration (mean ± s.e.m.) of eggs laid by females from small broods, 20.66±2.08 pg mg–1; medium broods, 15.32±1.94 pg mg–1; and large broods, 14.51±1.66 pg mg–1. Additionally, testosterone concentration decreased with laying order, and varied with clutch size in a complex way. Differences in egg testosterone between females exposed to different brood sizes are in line with previous findings in showing that early developmental stress can affect adult reproductive performance, although our study did not detect an effect in other breeding parameters, such as latency to breed or clutch size. Furthermore, the results are consistent with the hypothesis that there is a cost associated with yolk testosterone. However, it is still unclear what the nature of this cost may be, and whether it is paid by females, offspring, or both.
Escape manoeuvres in the spiny dogfish (Squalus acanthias)
Authors: Domenici Paolo , Standen Emily M. , Levine Robert P. 
Published: May 2004

SUMMARYThe locomotor performance of dogfish during escape responses was observed by means of high-speed video. Dogfish show C-type escape responses that are comparable with those shown previously in teleosts. Dogfish show high variability of turning rates of the anterior part of the body (head to centre of mass), i.e. with peak values from 434 to 1023 deg. s-1. We suggest that this variability may be due to the presence of two types of escape manoeuvres, i.e. responses with high and low turning rates, as previously found in a teleost species. Fast responses (i.e. with high maximum turning rates, ranging between 766 and 1023 deg. s-1) showed significantly higher locomotor performance than slow responses (i.e. with low maximum turning rates, ranging between 434 and 593 deg. s-1) in terms of distance covered, speed and acceleration, although no differences were found in the turning radius of the centre of mass during the escape manoeuvres. The existence of two types of escape responses would have implications in terms of both neural control and muscular activation patterns. When compared with literature data for the locomotor performance of bony fishes, dogfish showed relatively low speed and acceleration, comparable turning rates and a turning radius that is in the low part of the range when compared with teleosts, indicating relatively high manoeuvrability. The locomotor performance observed in dogfish is consistent with their morphological characteristics: (1) low locomotor performance associated with low thrust developed by their relatively small posterior depth of section and(2) relatively high manoeuvrability associated with their high flexibility.
Changes in gene expression associated with acclimation to constant temperatures and fluctuating daily temperatures in an annual killifishAustrofundulus limnaeus
Authors: Podrabsky Jason E. , Somero George N. 
Published: May 2004

SUMMARYEurythermal ectotherms commonly thrive in environments that expose them to large variations in temperature on daily and seasonal bases. The roles played by alterations in gene expression in enabling eurytherms to adjust to these two temporally distinct patterns of thermal stress are poorly understood. We used cDNA microarray analysis to examine changes in gene expression in a eurythermal fish, Austrofundulus limnaeus, subjected to long-term acclimation to constant temperatures of 20, 26 and 37°C and to environmentally realistic daily fluctuations in temperature between 20°C and 37°C. Our data reveal major differences between the transcriptional responses in the liver made during acclimation to constant temperatures and in response to daily temperature fluctuations. Control of cell growth and proliferation appears to be an important part of the response to change in temperature, based on large-scale changes in mRNA transcript levels for several key regulators of these pathways. However, cell growth and proliferation appear to be regulated by different genes in constant versus fluctuating temperature regimes. The gene expression response of molecular chaperones is also different between constant and fluctuating temperatures. Small heat shock proteins appear to play an important role in response to fluctuating temperatures whereas larger molecular mass chaperones such as Hsp70 and Hsp90 respond more strongly to chronic high temperatures. A number of transcripts that encode for enzymes involved in the biosynthesis of nitrogen-containing organic osmolytes have gene expression patterns that indicate a possible role for these `chemical chaperones' during acclimation to chronic high temperatures and daily temperature cycling. Genes important for the maintenance of membrane integrity are highly responsive to temperature change. Changes in fatty acid saturation may be important in long-term acclimation and in response to fluctuating temperatures; however cholesterol metabolism may be most critical for short-term acclimation to fluctuating temperatures. The variable effect of temperature on the expression of genes with daily rhythms of expression indicates that there is a complex interaction between the temperature cycle and daily rhythmicity in gene expression. A number of new hypotheses concerning temperature acclimation in fish have been generated as a result of this study. The most notable of these hypotheses is the possibility that the high mobility group b1 (HMGB1) protein, which plays key roles in the assembly of transcription initiation and enhanceosome complexes, may act as a compensatory modulator of transcription in response to temperature, and thus as a global gene expression temperature sensor. This study illustrates the utility of cDNA microarray approaches in both hypothesis-driven and `discovery-based' investigations of environmental effects on organisms.