bluuebunny/crossref_metadata_2025_split huggingface dataset:
Geographic variation in phenotypic plasticity in response to dissolved oxygen in an African cichlid fish
Authors: CRISPO E. , CHAPMAN L. J. 
Published: August 2010

AbstractGenetic adaptation and phenotypic plasticity are two ways in which organisms can adapt to local environmental conditions. We examined genetic and plastic variation in gill and brain size among swamp (low oxygen; hypoxic) and river (normal oxygen; normoxic) populations of an African cichlid fish,Pseudocrenilabrus multicolor victoriae. Larger gills and smaller brains should be advantageous when oxygen is low, and we hypothesized that the relative contribution of local genetic adaptation vs. phenotypic plasticity should be related to potential for dispersal between environments (because of gene flow’s constraint on local genetic adaptation). We conducted a laboratory‐rearing experiment, with broods from multiple populations raised under high‐oxygen and low‐oxygen conditions. We found that most of the variation in gill size was because of plasticity. However, both plastic and genetic effects on brain mass were detected, as were genetic effects on brain massplasticity. F1offspring from populations with the highest potential for dispersal between environments had characteristically smaller and more plastic brains. This phenotypic pattern might be adaptive in the face of gene flow, if smaller brains and increased plasticity confer higher average fitness across environment types.
Historical mutation rates predict susceptibility to radiation in Chernobyl birds
Authors: MØLLER A. P. , ERRITZøE J. , KARADAS F. , MOUSSEAU T. A. 
Published: August 2010

AbstractExtreme environmental perturbations are rare, but may have important evolutionary consequences. Responses to current perturbations may provide important information about the ability of living organisms to cope with similar conditions in the evolutionary past. Radioactive contamination from Chernobyl constitutes one such extreme perturbation, with significant but highly variable impact on local population density and mutation rates of different species of animals and plants. We explicitly tested the hypothesis that species with strong impacts of radiation on abundance were those with high rates of historical mutation accumulation as reflected by cytochrome b mitochondrial DNA base‐pair substitution rates during past environmental perturbations. Using a dataset of 32 species of birds, we show higher historical mitochondrial substitution rates in species with the strongest negative impact of local levels of radiation on local population density. These effects were robust to different estimates of impact of radiation on abundance, weighting of estimates of abundance by sample size, statistical control for similarity in the response among species because of common phylogenetic descent, and effects of population size and longevity. Therefore, species that respond strongly to the impact of radiation from Chernobyl are also the species that in the past have been most susceptible to factors that have caused high substitution rates in mitochondrial DNA.
Skeletogenesis by transfated secondary mesenchyme cells is dependent on extracellular matrix–ectoderm interactions in Paracentrotus lividus sea urchin embryos
Authors: Kiyomoto Masato , Zito Francesca , Costa Caterina , Poma Veronica , Sciarrino Serafina , Matranga Valeria 
Published: August 2010

In the sea urchin embryo, primary mesenchyme cells (PMCs) are committed early in development to direct skeletogenesis, provided that a permissive signal is conveyed from adjacent ectoderm cells. We showed that inhibition of extracellular matrix (ECM)–ectoderm cells interaction, by monoclonal antibodies (mAb) to Pl‐nectin, causes an impairment of skeletogenesis and reduced expression of Pl‐SM30, a spicule‐specific matrix protein. When PMCs are experimentally removed, some secondary mesenchyme cells (SMCs) switch to skeletogenic fate. Here, for the first time we studied SMC transfating in PMC‐less embryos of Paracentrotus lividus. We observed the appearance of skeletogenic cells within 10 h of PMCs removal, as shown by binding of wheat germ agglutinin (WGA) to cell surface molecules unique to PMCs. Interestingly, the number of WGA‐positive cells, expressing also msp130, another PMC‐specific marker, doubled with respect to that of PMCs present in normal embryos, though the number of SM30‐expressing cells remained constant. In addition, we investigated the ability of SMCs to direct skeletogenesis in embryos exposed to mAbs to Pl‐nectin after removal of PMCs. We found that, although phenotypic SMC transfating occurred, spicule development, as well as Pl‐SM30‐expression was strongly inhibited. These results demonstrate that ectoderm inductive signals are necessary for transfated SMCs to express genes needed for skeletogenesis.
Signaling pathways in ascidian oocyte maturation: The role of cyclic AMP and follicle cells in germinal vesicle breakdown
Authors: Lambert Charles C. 
Published: August 2010

Many ascidian oocytes undergo ‘spontaneous’ germinal vesicle breakdown (GVBD) when transferred from the ovary to normal pH 8.2 sea water (SW); however, low pH inhibits GVBD, which can then be stimulated while remaining in the low pH SW. Oocytes of Boltenia villosa blocked from GVBD by pH 4 SW undergo GVBD in response to permeant cyclic AMP (8‐bromo‐cyclic AMP), phosphodiesterase inhibitors (isobutylmethylxanthine and theophylline) or the adenylyl cyclase activator forskolin. This suggests that cAMP increases during GVBD. Removal of the follicle cells or addition of a protease inhibitor inhibits GVBD in response to raised pH but not to forskolin, theophylline or 8 bromo‐cAMP. Isolated follicle cells in low pH SW release protease activity in response to an increase in pH. These studies imply that the follicle cells release protease activity, which either itself stimulates an increase in oocyte cAMP level or reacts with other molecules to stimulate this process. Studies with the mitogen‐activated protein (MAP) kinase inhibitors U0126 and CI 1040 suggest that MAP kinase is not involved in GVBD. The Cdc25 inhibitor NSC 95397 inhibits GVBD at 200 nm in a reversible manner.
Development of the larval muscle system in the mussel Mytilus trossulus (Mollusca, Bivalvia)
Authors: Dyachuk Vyacheslav , Odintsova Nelly 
Published: August 2010

In the present study we examined muscle development throughout the complete larval cycle of the bivalve mollusc, Mytilus trossulus. An immunofluorescence technique and laser scanning confocal microscopy were used in order to study the organization of the muscle proteins (myosin, paramyosin, twitchin, and actin) and some neurotransmitters. The appearance of the muscle bundles lagged behind their nervous supply: the neuronal elements developed slightly earlier (by 2 h) than the muscle cells. The pioneer muscle cells forming a prototroch muscle ring were observed in a completed trochophore. We documented a well‐organized muscle system that consisted of the muscle ring transforming into three pairs of velar striated retractors in the early veliger. The striations were positive for all muscle proteins tested. Distribution of FMRFamide and serotonin (5‐HT) immunocytochemical staining relative to the muscle ring differed significantly: 5‐HT‐immunioreactive cells were situated in the center of the striated muscle ring, while Phe‐Met‐Arg‐Phe‐NH2 neuropeptide FMRFamid immunoreactive fibers were located in a distal part of this ring. Our data showed clearly that the muscle proteins and the neurotransmitters were co‐expressed in a coordinated fashion in a continuum during the early stages of the mussel development. Our study provides the first strong evidence that mussel larval metamorphosis is accompanied by a massive reorganization of striated muscles, followed by the development of smooth muscles capable of catch‐contraction.
The Sperm‐surface glycoprotein, SGP, is necessary for fertilization in the frog, Xenopus laevis
Authors: Nagai Keita , Ishida Takuya , Hashimoto Takafumi , Harada Yuichirou , Ueno Shuichi , Ueda Yasushi , Kubo Hideo , Iwao Yasuhiro 
Published: August 2010

To identify a molecule involved in sperm‐egg plasma membrane binding at fertilization, a monoclonal antibody against a sperm‐surface glycoprotein (SGP) was obtained by immunizing mice with a sperm membrane fraction of the frog, Xenopus laevis, followed by screening of the culture supernatants based on their inhibitory activity against fertilization. The fertilization of both jellied and denuded eggs was effectively inhibited by pretreatment of sperm with intact anti‐SGP antibody as well as its Fab fragment, indicating that the antibody recognizes a molecule on the sperm's surface that is necessary for fertilization. On Western blots, the anti‐SGP antibody recognized large molecules, with molecular masses of 65–150 kDa and minor smaller molecules with masses of 20–28 kDa in the sperm membrane vesicles. SGP was distributed over nearly the entire surface of the sperm, probably as an integral membrane protein in close association with microfilaments. More membrane vesicles containing SGP bound to the surface were found in the animal hemisphere compared with the vegetal hemisphere in unfertilized eggs, but the vesicle‐binding was not observed in fertilized eggs. These results indicate that SGP mediates sperm‐egg membrane binding and is responsible for the establishment of fertilization in Xenopus.
Hepatitis C virus prevalence and outcomes among injecting drug users on opioid replacement therapy
Authors: HALLINAN RICHARD , BYRNE ANDREW , AMIN JANAKI , DORE GREGORY J 
Published: August 2010

AbstractObjectives: To determine hepatitis C virus (HCV) prevalence among injecting drug users (IDUs) receiving opioid replacement therapy in a referred office setting, and assess potential needs for hepatitis C treatment and care.Methods: Data were collected on 178 IDUs receiving opioid replacement therapy who underwent clinical assessment between January 2002 and June 2003. Standard clinic protocols included HCV and hepatitis B virus (HBV) serology, liver biochemistry and HCV RNA analysis for patients with a positive HCV antibody and normal alanine aminotransferase (ALT) levels.Results: HCV prevalence was 75.3%, similar for males (75.5%) and females (74.4%), and increased with age from 60.8% for 19–30 years to 93.9% above 40 years. Among patients with HCV antibodies and no prior HCV antiviral therapy (n = 130), 53.1% had normal ALT levels and 25.4% were HCV‐RNA negative. Older patients were more likely to have normal ALT levels (P = 0.02), and be HCV‐RNA negative (P = 0.02). Younger patients were more likely to have been HBV vaccinated (P < 0.001), however, were less likely to have either vaccine or natural immunity (P = 0.006). Of 97 patients with probable chronic HCV infection, 58 patients met pre‐liver biopsy criteria for HCV treatment, 34 had relative contraindications to treatment and 6 had been referred for treatment assessment.Conclusion: Clinical characterization in a setting of high HCV prevalence has enabled the differentiation of patients into groups with no evidence of HCV viraemia, with chronic HCV infection, and those most appropriate for HCV treatment referral. These clinical assessments along with appropriate referral should be instituted in drug dependency treatment settings.
Outbreak of hepatitis C virus infection in an outpatient clinic
Authors: ISHIKAWA TAKASHI , FUKUSHIMA YASUSHI , SHIOBARA YUJIRO , KISHIMOTO TSUYOSHI , TANNO SAKIKO , SHOJI IKUO , SUZUKI TETSURO , MATSUI TAMANO , SHIMADA YASUSHI , OHYAMA TAKAAKI , NAGAI RYOZO , MIYAMURA TATSUO 
Published: August 2010

AbstractBackground:  From January through September 2001, seven patients were admitted to Fukaya Red Cross Hospital with typical clinical manifestations of acute hepatitis. Six were outpatients of the clinic, which is located near the hospital. An extensive survey of clinic outpatients conducted by the local health department revealed six more new acute hepatitis cases during this period.Methods:  A case control study was carried out to identify potential risk factors for infection. In total, 1946 outpatients with clinic records were scheduled to undergo hepatitis C virus (HCV)‐antibody testing. For the HCV‐Ab positive patients, HCV‐RNA was subtyped and quantified, and sequences of HCV hypervariable region 1 were determined.Results:  Ultimately, 12 patients with acute hepatitis and two asymptomatic subjects were found to be a part of this outbreak. HCV isolates were divided into three major groups using phylogenetic tree analysis. Only a past history of visiting the clinic was significantly associated with acute hepatitis. The timing of the parenteral medical procedure at the clinic and the onset of acute hepatitis strongly suggested association of the two events.Conclusions:  Our findings suggest that nosocomial HCV infection can occur in an outpatient clinic, even in countries where post‐transfusion hepatitis has been almost entirely eliminated.
Hydroxyproline content of needle biopsies as an objective measure of liver fibrosis: Emphasis on sampling variability
Authors: LEE HSUAN‐SHU , SHUN CHIA‐TUNG , CHIOU LING‐LING , CHEN CHIEN‐HUNG , HUANG GUAN‐TARN , SHEU JIN‐CHUAN 
Published: August 2010

AbstractBackground:  Needle liver biopsy is essential for the diagnosis of liver fibrosis and cirrhosis. However, sampling variability has been reported by semiquantitative methods. The aim of the present study was to investigate quantitatively the sampling variability of needle liver biopsy on the assessment of liver fibrosis/cirrhosis.Methods:  Liver samples of 12 patients undergoing autopsy, liver transplantation, or liver tumor resection were investigated. Nine to 10 liver biopsies at least 5 mm apart were taken from each of 12 removed human livers using Trucut needles. Hydroxyproline level of each liver core was determined. Sections >1 cm2 and stained by Sirius red were used for the reference staging of liver fibrosis in each patient according to the METAVIR scoring system.Results:  Hydroxyproline levels for the three groups, F0‐1, F2‐3, and F4, were significantly elevated as the fibrosis score increased. There was a wide range of hydroxyproline contents for the 9–10 biopsy samples from each liver, the coefficient of variation being between 13% and 36% (mean, 23%). Several differences were noted between the amount of collagen present according to hydroxyproline measurement and the stages of fibrosis according to histology.Conclusions:  Although increases in collagen content (by hydroxyproline) approximately paralleled increases in fibrosis stage (by histology), there was considerable overlap and some discrepancies. Much work remains to be done to clarify the significance of the apparent huge variations in fibrosis within diseased livers. It is advisable for clinicians to interpret staging diagnoses by histological staging with some caution.
Effects of somatostatin, terlipressin and somatostatin plus terlipressin on portal and systemic hemodynamics and renal sodium excretion in patients with cirrhosis
Authors: KALAMBOKIS GEORGIOS , ECONOMOU MICHALIS , PARASKEVI KOSTA , KONSTANTINOS PAPADIMITRIOU , PAPPAS CHRISTOS , KATSARAKI AFRODITI , TSIANOS EPAMEINONDAS V 
Published: August 2010

AbstractBackground and Aim:  Terlipressin and somatostatin are the most preferable agents for the control of variceal bleeding in cirrhotic patients. The present study evaluated the hemodynamic effects of somatostatin, terlipressin and somatostatin plus terlipressin in cirrhotic patients with portal hypertension, as well as the effect of each regimen on renal sodium excretion.Methods:  Twenty‐four patients with esophageal varices were randomly assigned to receive either an intravenous infusion of a placebo (n = 12) or somatostatin 250 µg/h after an initial bolus of 250 µg (n = 12) for 60 min. Thereafter, each patient received an intravenous injection of terlipressin 2 mg while the intravenous infusion of either somatostatin or placebo was maintained. Portal and systemic hemodynamic parameters, assessed by Doppler sonography, and urinary sodium excretion were evaluated at baseline, 60 min after placebo or somatostatin, and 30 min after terlipressin.Results:  Placebo had no effect on the patients studied. After terlipressin, portal vein velocity, portal flow volume and cardiac output (CO) significantly decreased (0.09 vs 0.15 m/s, 0.56 vs 1 L/min and 6.4 vs 7.6 L/min, respectively [values are medians]), while mean arterial pressure (MAP) and systemic vascular resistance significantly increased (103.3 vs 89.9 mmHg and 1541 vs 1108dyn.s/cm5, respectively). Fractional sodium excretion significantly increased in patients without ascites (0.43 vs 0.16%) while it did not change in patients with ascites. Somatostatin did not alter portal hemodynamics whereas it significantly reduced MAP, heart rate (HR) and CO (86.9 vs 98.6 mmHg, 65 vs 73 bpm and 8.4 vs 9.1 L/min, respectively) and, in patients with ascites, sodium excretion (0.13 vs 0.23%). The addition of terlipressin to somatostatin induced similar changes to those observed after terlipressin alone. The magnitude of increase in MAP was significantly higher in patients receiving terlipressin alone than in those receiving somatostatin plus terlipressin (15 vs 5.3%), while CO was conversely affected (−28.5 vs−20.9%).Conclusions:  Combined treatment with somatostatin and terlipressin does not exert an additive portal hypotensive effect in cirrhotic patients as compared to terlipressin alone, whereas somatostatin alone may impair systemic hemodynamics. Compared with somatostatin, terlipressin exerts a more beneficial effect on renal sodium excretion in patients with or without ascites.
Aberrant expression and localization of hnRNP‐A2/B1 is a common event in human gastric adenocarcinoma
Authors: Jing Guang‐Jun , Xu Dong‐Hui , Shi Song‐Lin , Li Qi‐Fu , Wang San‐Ying , Wu Fu‐Yun , Kong Hai‐Yan 
Published: August 2010

AbstractBackground and Aim:  Nuclear‐matrix proteins can be proteomic markers for cancer lesions. The present study aimed to determine the roles of heterogeneous nuclear ribonucleoproteins‐A2 and B1 (hnRNP‐A2/B1) in human gastric carcinogenesis.Methods:  Human gastric cancer and non‐cancerous tissues were collected for immunohistochemical analysis. Proteomics technique, Western blot, laser confocal microscope, and real‐time quantitative reverse transcription–polymerase chain reaction were performed to determine the aberrant expression of nuclear‐matrix proteins.Results:  hnRNP‐A2/B1 existed in the nuclear matrix of gastric cancer cells, and its expression was enhanced in human gastric cancer and decreased by hexamethylene bisacetamide. The colocalization of hnRNP‐A2/B1 with c‐myc, c‐fos, p53, and Rb was translocated from the nucleolus to the cytoplasm during the differentiation of tumor cells.Conclusions:  hnRNP‐A2/B1 affected tumor cell differentiation through interaction with oncogenes and tumor‐suppressor genes, and it was overexpressed in human gastric cancer. We postulate that hnRNP‐A2/B1 could serve as a biomarker for the diagnosis of human gastric cancer.
Analysis of K‐ras, BRAF, and PIK3CA mutations in laterally‐spreading tumors of the colorectum
Authors: Kaji Eisuke , Kato Jun , Suzuki Hideyuki , Akita Mitsuhiro , Horii Joichiro , Saito Shunsuke , Higashi Reiji , Ishikawa Shin , Kuriyama Motoaki , Hiraoka Sakiko , Uraoka Toshio , Yamamoto Kazuhide 
Published: August 2010

AbstractBackground and Aims:  Laterally‐spreading tumors (LST) are a newly‐recognized category of colorectal neoplasia, and are defined as lesions larger than 10 mm in diameter and extending circumferentially rather than vertically. However, genetic features of this new category of tumors are not fully elucidated. The aim of this study was to evaluate genetic alterations in LST.Methods:  We examined K‐ras, BRAF, and phosphoinositide‐3‐kinase catalytic‐α polypeptide (PIK3CA) mutations in 101 LST, including 68 LST‐granular type (LST‐G) and 33 LST‐non‐granular type by direct sequencing. As controls, we examined these gene mutations in 66 protruded colon adenomas (10 mm or larger) and 44 advanced colon cancers.Results:  K‐ras, BRAF, and PIK3CA mutations were observed in 59 (58%), zero (0%), and three (3%) LST, respectively. LST‐G morphology in the right‐sided colon was significantly correlated with the existence of K‐ras mutations, whereas a size of 20 mm or larger was the only predictor of mutations in the left‐sided colorectum. The frequency of K‐ras mutations in LST was particularly marked in the left‐sided colorectum compared to protruded adenomas or advanced cancers (LST vs protruded adenomas, P < 0.001; LST vs advanced cancers, P = 0.002), whereas in the right‐sided colon, K‐ras mutations were equally frequent. PIK3CA mutations were not familiar in either LST (3%) or advanced cancers (9%).Conclusions:  K‐ras mutations were involved in colorectal LST in different manners according to tumor location.
Controversies of cardiac glands in the proximal stomach: A critical review
Authors: Huang Qin 
Published: August 2010

AbstractCardiac glands (CG), along with oxyntocardiac glands, in a normal human constitute cardiac mucosa (CM) that is positioned in the proximal stomach with a length of 10–30 mm, according to traditional teaching. This doctrine has been recently challenged. On the basis of studies on autopsy and biopsy materials in the esophagogastric junction region, some investigators have reported the presence of CG in only 50% of the general US population. They believed that CG were an acquired, metaplastic lesion as a result of gastroesophageal reflux disease. Subsequent recent study results from other research groups showed the presence of CG in the proximal stomach in embryos, fetuses, pediatric, and adult patients in most Europeans and Americans, and almost all Japanese and Chinese patients. These new data showed the following important findings: (i) CG are confirmed to be congenital in the proximal stomach; (ii) the length of CM is much shorter, approximately 5 mm in Caucasians in Europe and North America, and approximately 13 mm in Japanese and probably also in Chinese; (iii) CG are also present in the distal superficial esophagus underneath squamous mucosa in almost all Japanese and Chinese patients, but not so common in Caucasians in Europe, and not clear in Caucasians in North America. The recent data indicate a clear difference in the distribution of CG in the proximal stomach among different ethnic populations, and might explain different disease pathogenesis mechanisms among various ethnic patient groups.