bluuebunny/crossref_metadata_2025_split huggingface dataset:
Exposure assessment in epidemiology: Does gender matter?
Authors: Kennedy Susan M. , Koehoorn Mieke 
Published: November 2003

AbstractBackgroundThe pathway from potential hazards in the work environment to the measurement or estimation of personal exposure for epidemiologic studies comprises many steps, each of which can be influenced by factors that may or may not differ by gender. This article explores this pathway to address the question, “Should the potential for gender differences be taken into account in the activity of exposure assessment for epidemiologic studies?”MethodsEvidence from previously published studies and data from the investigators' own research were examined to explore whether or not several theoretical sources of gender ‘bias’ in exposure assessment have been found in actual studies. Sources of bias examined included: differences in job tasks despite same job titles; differences in delivered exposure due to differences in protective equipment, body size, or other relationships to exposure sources; and differences in estimated exposure arising from study methods or design.Results and ConclusionsEvidence was found for gender differences (and thus potential bias) from all these sources, at least in some studies. We conclude that the answer to the question posed, “Does gender matter, in exposure assessment for epidemiology?” is a qualified ‘yes,’ but that the magnitude and direction of the potential bias cannot be predicted, a priori. Am. J. Ind. Med. 44:576–583, 2003. © 2003 Wiley‐Liss, Inc.
Cancer incidence among laboratory workers in biomedical research and routine laboratories in Israel: Part I—the cohort study
Authors: Shaham Judith , Gurvich Rachel , Kneshet Yael 
Published: November 2003

AbstractBackgroundLaboratory work is associated with exposure to a mixture of carcinogens.MethodsThe cohort is comprised of 4,300 laboratory workers. Cancer incidence was followed from 1960 to 1997.ResultsA total of 230 cases were included in the cohort. The overall cancer standardized incidence ratio (SIR) was 1.04 (0.91–1.18). When a 20‐year latency was introduced, SIR was increased significantly: 1.35 (1.13–1.61). Among routine workers and researchers, SIR was elevated significantly for the total population and for women, when a 20‐year latency was introduced. SIR was also elevated significantly in research, routine, bacteriology and virology, and isotope laboratories. With respect to specific sites, significantly increased SIR was observed in breast, ovary, and thyroid cancer among women; and prostate cancer, leukemia, and melanoma among men.ConclusionsWe suggest that work in research and biomedical laboratories might involve an increased risk of certain types of cancer. Am. J. Ind. Med. 44:600–610, 2003. © 2003 Wiley‐Liss, Inc.
Kinesin motors as molecular machines
Authors: Endow Sharyn A. 
Published: November 2003

AbstractMolecular motor proteins, fueled by energy from ATP hydrolysis, move along actin filaments or microtubules, performing work in the cell. The kinesin microtubule motors transport vesicles or organelles, assemble bipolar spindles or depolymerize microtubules, functioning in basic cellular processes. The mechanism by which motor proteins convert energy from ATP hydrolysis into work is likely to differ in basic ways from man‐made machines. Several mechanical elements of the kinesin motors have now been tentatively identified, permitting researchers to begin to decipher the mechanism of motor function. The force‐producing conformational changes of the motor and the means by which they are amplified are probably different for the plus‐ and minus‐end kinesin motors. BioEssays 25:1212–1219, 2003. © 2003 Wiley Periodicals, Inc.
Investigating protein–protein interfaces in bacterial transcription complexes: a fragmentation approach
Authors: Burrows Patricia C. 
Published: November 2003

AbstractTranscription initiation by σ54–RNA polymerase (RNAP) relies explicitly on a transient interaction with a complex molecular machine belonging to the AAA+ (ATPases associated with various cellular activities) superfamily. Members of the AAA+ superfamily convert chemical energy derived from NTP hydrolysis to a mechanical force used to remodel their target substrate. Recently Bordes and colleagues,1 using a protein fragmentation approach, identified a unique sequence within σ54‐dependent transcriptional activators that constitutes a σ54‐binding interface. This interface is not static, but subject to nucleotide‐dependent movement which may represent a common mechanism for controlling output that has been adopted by other AAA+ proteins. BioEssays 25:1150–1153, 2003. © 2003 Wiley Periodicals, Inc.
Stereospecificity of flobufen metabolism in guinea pigs in vitro and in vivo: Phase I of biotransformation
Authors: Kral Radim , Skalova Lenka , Szotakova Barbora , Babu Yogeeta N. , Wsol Vladimir 
Published: November 2003

AbstractFlobufen (F) is an original nonsteroidal antiinflammatory drug that exists in two enantiomeric forms. Its biotransformation was investigated in male guinea pigs because of the similarities shown in a preliminary F metabolic study between guinea pig and man. Stereospecificity of the respective enzymes was studied in vitro, using microsomes and cytosol, and in vivo, in urine and feces. Rac‐F, R‐F, and S‐F served as substrates. The amount of 4‐dihydroflobufen stereoisomers (DHF) and other metabolites (M‐17203 and UM‐2) was determined by chiral HPLC using an R,R‐ULMO column. It was observed that F reductases were distributed differently in microsomes and cytosol. The microsomal fraction showed higher activity and different stereospecificity in rac‐F, R‐F, and S‐F reduction compared to cytosol. (2R;4S)‐DHF was the principle metabolite in microsomes and (2S;4S)‐DHF was the principle metabolite in cytosol. In vivo experiments revealed the excretion of a main metabolite UM‐2 in addition to other metabolites M‐17203 and DHF stereoisomers. UM‐2 was predominantly excreted after S‐F administration. Stereoselectivity of DHF stereoisomers excretion was different in urine and in feces. The absence of UM‐2 and M‐17203 in microsomes and cytosol and their presence in urine and feces showed that both could arise in some other extrahepatic tissue or cell compartment or that their formation depends on liver cell integrity. Chirality 16:1–9, 2004. © 2003 Wiley‐Liss, Inc.
Novel chiral sulfur‐containing ferrocenyl ligands for palladium‐catalyzed asymmetric allylic substitution
Authors: Nakamura Shuichi , Fukuzumi Takeo , Toru Takeshi 
Published: November 2003

AbstractNew chiral ferrocenyl ligands having chiral sulfinyl and phosphinyl groups were prepared. The palladium‐catalyzed allylic substitution reaction using these chiral ligands showed good enantioselectivity. The mechanism for the asymmetric reaction is proposed on the basis of the stereochemical outcome. Chirality 16:10–12, 2004. © 2003 Wiley‐Liss, Inc.
Enantioresolution of fluorinated diphenylmethanols and determination of their absolute configurations by X‐Ray crystallographic and 1H NMR anisotropy methods
Authors: Naito Junpei , Kosaka Masashi , Sugito Takeo , Watanabe Masataka , Harada Nobuyuki , Pirkle William H. 
Published: November 2003

AbstractVarious fluorinated diphenylmethanols were enantioresolved by the methods of chiral camphorsultam‐dichlorophthalic acid (CSDP acid) and/or 2‐methoxy‐2‐(1‐naphthyl)propionic acid (MαNP acid) yielding enantiopure alcohols. Their absolute configurations were unambiguously determined by X‐ray crystallography of CSDP esters and/or by the 1H NMR anisotropy method of MαNP esters for the first time. Chirality 16:22–35, 2004. © 2003 Wiley‐Liss, Inc.
Separation of cefoperazone enantiomers using β‐cyclodextrin as chiral additive by capillary zone electrophoresis
Authors: Wang Rong , Jia Zheng‐Ping , Fan Jun‐Jie , Hu Xiao‐Li , Li Yong‐Min , Chen Li‐Ren , Xie Jing‐Wen , Zhang Qiang 
Published: November 2003

AbstractA capillary electrophoresis method was developed to separate the enantiomers of cefoperazone. Different cyclodextrins, including α‐cyclodextrin (α‐CD), β‐cyclodextrin (β‐CD), γ‐cyclodextrin (γ‐CD), 2‐hydroxypropyl‐β‐cyclodextrin (HP‐β‐CD), and methyl‐β‐cyclodextrin (Me‐β‐CD), were tested as chiral additives in the running buffer. The effect of various parameters on enantioseparation such as concentration of NaH2PO4, buffer pH, and CD concentration was also studied. The cefoperazone enantiomers were baseline separated under conditions of 0.04 mmol/L β‐CD, 75 mmol/L NaH2PO4 buffer at pH 4.0. A fused silica capillary (40 cm effective length × 75 μm ID) was used. The applied voltage and capillary temperature were 20 kV and 25°C, respectively. Under these conditions, linear calibration curves were obtained in the 5–500 μg/ml range using UV detection at 280 nm. The limit of detection for both isomers was 0.1 μg/ml. The method was used for the analysis of different pharmaceutical preparations (dose) and biological samples containing cefoperazone. Chirality 16:45–49, 2004. © 2003 Wiley‐Liss, Inc.
Concentration of a potent calcium oxalate monohydrate crystal growth inhibitor in the urine of normal persons and kidney stone patients by ELISA‐based assay system employing monoclonal antibodies
Authors: Moghadam Mehdi F. , Tandon C. , Aggarwal S. , Singla S.K. , Singh S.K. , Sharma S.K. , Varshney G.C. , Jethi R.K. 
Published: November 2003

AbstractStandardized calcium oxalate monohydrate (COM) crystal growth assay system was employed to study the ability of various test samples to influence growth rates of COM crystals. The inhibitory activity (IA) of various samples was expressed in terms of inhibitory units. Urine samples obtained from normal persons and kidney stone patients were found to have IA of 3.18 ± 0.62 and 1.02 ± 0.08, respectively. A potent inhibitor having molecular weight between 14.2 and 16.2 kDa was found to be primarily responsible for the differences observed in the urinary IAs between normal persons and kidney stone patients. The potent inhibitor was found to be tightly associated with a chromophore resembling Urobilirubin. An ELISA based assay system, using monoclonal antibodies against the above most potent inhibitor confirmed the difference observed in the urinary IA between the normal persons and kidney stone patients. This assay system has the potential to be routinely used to screen human beings for potential stone formers. © 2003 Wiley‐Liss, Inc.
Molecular imaging of proteolytic activity in cancer
Authors: McIntyre J. Oliver , Matrisian Lynn M. 
Published: November 2003

AbstractThe early detection of both primary tumors and metastatic disease continue to be significant challenges in the diagnosis and staging of cancer. The growing recognition of the role of proteinases and proteolytic cascades in both the growth and metastasis of tumors has led to the development not only of therapeutic strategies using proteinase inhibitors, but also of methods to detect and image tumors in vivo via tumor‐associated proteolytic activities. These imaging strategies derive from the enhanced sensitivity afforded by amplification that can be obtained by enzymatic processing to increase the efficacy of imaging “contrast agents” coupled with the inherent substrate specificity and selectivity of proteinases. This review describes key proteinases important in cancer progression, the strategies that have been devised to detect and image proteolytic activity in vivo, and the potential for this kind of functional imaging to serve as a marker for targeted therapy. The intent is to draw attention to the developing methods of molecular imaging to facilitate not only cancer diagnosis, but also for devising strategies for individualized targeted therapy and non‐invasive monitoring of therapeutic efficacy. © 2003 Wiley‐Liss, Inc.
Thymic epithelial cells in age‐dependent involution
Authors: Brelińska Renata 
Published: November 2003

AbstractAging involves morphological and functional alterations within the microenvironment of the thymus where heterogenous populations of thymic epithelial cells (TEC) play the main roles. The studies performed to date on thymic involution signalize a disturbed interaction between individual thymic compartments that disrupt thymocyte‐TEC interactions and, as a sequele, disturb differentiation of both TEC and thymocytes. The process of aging affects the various subsets of TEC at different periods of life. Changes in different subsets of TEC are documented on the basis of their phenotypical characteristics, involving morphological analysis and immunocytochemistry. The character and kinetics of changes in TEC are typical for individual subsets and probably sex‐dependent. In the course of life, the involutionary changes, expressed by disorganised thymic structure and function, are accompanied by changes in medullary TEC, manifested by alterations in the differentiation process of the cells. In parallel, at the same stage of individual life, the aging process induces increased proliferative and secretory activity of subseptal TEC, which seem to functionally replace medullary TEC. Structural and phenotypic modifications of TEC are locally controlled by complex sets of different factors and seem to represent a morphological adaptation of the gland to the process of aging. Microsc. Res. Tech. 62:488–500, 2003. © 2003 Wiley‐Liss, Inc.
Age‐related changes in the function of T cells
Authors: Aspinall Richard 
Published: November 2003

AbstractAt the start of the last century in the United Kingdom, only 24% of the 587,830 deaths registered were of individuals over 65, but by the end of the century these figures had changed markedly. Of the 558,052 deaths in 1997, 84% were in the population over 65. This “right shift” in the survival curve is projected to continue. The UK Government Actuary's Department forecast that by 2020, 11.75 million people (19% of the population) will be over 65 rising to 15.1 million people (25% of the population) by 2040. Older members of society show infections of the urinary tract, respiratory tract, skin, soft tissue or intra‐abdominal region, infectious endocarditis, bacterial meningitis, tuberculosis, and herpes zoster, at a higher incidence than among younger adults. Moreover, mortality rates for these diseases are often 2–3 times higher among elderly patients than younger individuals with the same disease. The higher morbidity and mortality from these infections, plus the increased prevalence of specific cancers and certain autoimmune diseases point to an immune system deteriorating with age. At the core of the immune system are the T cells and this review analyses possible causes for the changes in T cell function that may account for the deterioration of the immune system. Any intervention to reverse the decline in the immune system must have a rational basis built on a hypothesis‐driven inquiry, and one such intervention process is presented here. Microsc. Res. Tech. 62:508–513, 2003. © 2003 Wiley‐Liss, Inc.
Predictive value of early HCV RNA quantitation for sustained response in nonresponders receiving daily interferon and ribavirin therapy
Authors: Trimoulet Pascale , de Lédinghen Victor , Foucher Juliette , Castéra Laurent , Fleury Hervé , Couzigou Patrice 
Published: November 2003

AbstractThe prognostic value of early hepatitis C virus (HCV)‐RNA load was evaluated among nonresponder patients to previous interferon (IFN) therapy treated with daily IFN and ribavirin. One hundred‐six nonresponders (83 men), mean age 44.8 ± 11 years, were treated with IFN‐α2b 3 MU/day for 24 weeks, followed by 3 MU × 3/week for 24 weeks plus ribavirin 1–1.2 g/day for 48 weeks. HCV RNA was quantified by Versant HCV RNA 3.0 assay (Bayer). The predictive values of the baseline and the change in viral load at week 1, 4, and 12 for sustained virological responses were analyzed using receiver operating characteristic (ROC) curves, as well as predictive values of >2 log10 drop from baseline by weeks 1, 4, and 12 in combination with undetectable HCV RNA for sustained virological response. Thirty‐two patients (30.2%) were sustained virological responders. The highest area under the curve was obtained at week 4. The unquantifiable HCV RNA level, in combination with at least a 2 log10 drop in viral load by week 4 and week 12, had a negative predictive value of 96% and 97%, respectively. Nonresponse can be predicted as early as week 4 or week 12 in nonresponders treated with daily IFN and ribavirin. J. Med. Virol. 72:46–51, 2004. © 2004 Wiley‐Liss, Inc.
Time course of hepatitis A viremia and viral load in the blood of human hepatitis A patients
Authors: Normann Andrea , Jung Christian , Vallbracht Angelika , Flehmig Bertram 
Published: November 2003

AbstractThe hepatitis A virus (HAV) is the most common etiological cause of acute hepatitis infections in humans in industrialized countries. Investigations into the viral load during HAV viremia, however, are rare. Therefore, correlation studies between viral load, biochemical, and specific serological markers have been undertaken. The group of sera comprised a series of multiple consecutive blood samples drawn from 11 patients at different times after onset of the disease. During the period up to 70 days after the onset of icterus, the individual range was at 1×103 to 3×104 HAV genome equivalents/ml. From day 75 until 120 after onset of the disease, the levels traced were at 103. In one case, it was possible to trace 1.25×104 genome equivalents/ml up to 180 days after onset of icterus and in two cases even up to 408 and 490 days viral load levels of 5×103 and 4×104 were detected, respectively. The same sera were used to measure IgM class antibodies to hepatitis A virus and the total anti‐HAV. The results demonstrate that a direct correlation to peak levels of viral load exists with peak serum transaminase levels, but neither with peak anti‐HAV IgM levels nor with total anti‐HAV. Decreasing amounts of anti‐HAV IgM tend to occur with decreasing amounts of HAV genome equivalents; and, vice versa, increasing amounts of total anti‐HAV are accompanied by decreasing amounts of HAV genome equivalents. The longest duration of viremia was found in patients infected with HAV genotype IA. J. Med. Virol. 72:10–16, 2004. © 2004 Wiley‐Liss, Inc.
Prevalence and characterization of astroviruses in Argentinean children with acute gastroenteritis
Authors: Espul Carlos , Martínez Norma , Noel Jacqueline S. , Cuello Hector , Abrile Cristina , Grucci Sandra , Glass Roger , Berke Tamas , Matson David O. 
Published: November 2003

AbstractAmong viral agents causing gastroenteritis, human astroviruses (HAstVs) take second or third place, after rotaviruses and caliciviruses, as the most frequent cause of illness. The aims of this study were to determine the prevalence of HAstV infection and to characterize the circulating HAstV strains in children with diarrhea under 3 years of age treated between 1995 and 1998 at out‐ or in‐patient facilities of the children's hospital in Mendoza, Argentina. Reverse transcription‐polymerase chain reaction (RT‐PCR) and enzyme immunoassay (EIA) were used to detect HAstVs in stool specimens. Positive specimens were tested further by EIA and/or sequenced to type detected HAstV strains. HAstVs were detected in 40 (3.7%) of 1,070 samples that were rotavirus and calicivirus‐negative: 14 (3.5%) of 402 from outpatients and 26 (3.9%) of 668 from inpatients. HAstV infection tended to be more severe in children during their first year of life: 18 (4.7%) of 383 HAstV‐positive children 0–11 months old were hospitalized versus 8 (2.8%) of 285 children 1 year of age or older (P = 0.29). Type 1 (HAstV‐1) was the most common type (41%), followed by HAstV‐4 (25%), HAstV‐2 (13%), HAstV‐3 (13%), and HAstV‐5 (8%). In this first epidemiological study of HAstV infection in this region, we confirmed HAstV to be a cause of severe gastroenteritis in children, more often among children younger than 12 months of age. HastV‐4 caused 25% of HastV infections in Mendoza, although it has been detected commonly elsewhere. Distinct genetic lineages were apparent but their epidemiological significance remains to be demonstrated. J. Med. Virol. 72:75–82, 2004. © 2004 Wiley‐Liss, Inc.
Stress‐induced subclinical reactivation of varicella zoster virus in astronauts
Authors: Mehta Satish K. , Cohrs Randall J. , Forghani Bagher , Zerbe Gary , Gilden Donald H. , Pierson Duane L. 
Published: November 2003

AbstractVaricella zoster virus (VZV) becomes latent in human ganglia after primary infection. VZV reactivation occurs primarily in elderly individuals, organ transplant recipients, and patients with cancer and AIDS, correlating with a specific decline in cell‐mediated immunity to the virus. VZV can also reactivate after surgical stress. The unexpected occurrence of thoracic zoster 2 days before space flight in a 47‐year‐old healthy astronaut from a pool of 81 physically fit astronauts prompted our search for VZV reactivation during times of stress to determine whether VZV can also reactivate after non‐surgical stress. We examined total DNA extracted from 312 saliva samples of eight astronauts before, during, and after space flight for VZV DNA by polymerase chain reaction: 112 samples were obtained 234–265 days before flight, 84 samples on days 2 through 13 of space flight, and 116 samples on days 1 through 15 after flight. Before space flight, only one of the 112 saliva samples from a single astronaut was positive for VZV DNA. In contrast, during and after space flight, 61 of 200 (30%) saliva samples were positive in all eight astronauts. No VZV DNA was detected in any of 88 saliva samples from 10 healthy control subjects. These results indicate that VZV can reactivate subclinically in healthy individuals after non‐surgical stress. J. Med. Virol. 72:174–179, 2004. © 2004 Wiley‐Liss, Inc.
Differential regulation of polysialyltransferase expression during hippocampus development: Implications for neuronal survival
Authors: Brocco Marcela , Pollevick Guido D. , Frasch Alberto C.C. 
Published: November 2003

AbstractPolysialyltransferases ST8SiaII/STX and ST8SiaIV/PST add polysialic acid (PSA) to the neural cell adhesion molecule (NCAM). Surface‐located PSA is involved in cell–cell interactions participating in structural and functional plasticity of neuronal circuits. This study was undertaken to investigate the polysialyltransferase regulation pattern during hippocampal development. Polysialyltransferase expression levels analyzed by real‐time RT‐PCR indicated that ST8SiaII/STX mRNA is markedly down‐regulated in vivo, decreasing abruptly at about the first week of postnatal development. ST8SiaII/STX mRNA is also down‐regulated in hippocampal cells in culture, accompanying the morphological differentiation of neuronal interconnectivity. In contrast, ST8SiaIV/PST levels remain comparatively low during hippocampus ontogeny. Immunolabeling of primary hippocampal culture assays demonstrated that PSA expression parallels ST8SiaII/STX mRNA levels. In comparison, polysialyltransferase mRNA levels are not regulated in neuroblastoma cells during their proliferation. Sequence analysis of the 3′‐untranslated region of ST8SiaII/STX cDNA indicated putative regulatory motifs. This information and the observed changes in mRNA half‐life during development suggest that ST8SiaII/STX might be also regulated at the posttranscriptional level. To understand the reasons for the tight control of ST8SiaII/STX expression during development, we overexpressed the enzyme in hippocampal primary cultures by transfection. Overexpression of ST8SiaII/STX wild type as well as of a mutant lacking enzymatic activity affected neuronal viability, leading to cell death. However, this phenomenon was abolished by a double mutation in the ST8SiaII/STX that prevents formation of its three‐dimentional structure. Interestingly, the overexpressed polysialyltransferase accumulates not only in the perinuclear region but also in the plasma membrane. Thus, overexpression of an ST8SiaII/STX that conserves its structure leads to abnormal accumulation of the protein, probably on the neuronal surface, affecting cell viability. This result explains the importance of an accurate regulation of polysialyltransferase expression during development. © 2003 Wiley‐Liss, Inc.