bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mutation-selection balance accounting for genetic variation for viability in Drosophila melanogaster as deduced from an inbreeding and artificial selection experiment
Authors: Rodríguez-Ramilo S. T. , Pérez-Figueroa A. , Fernández B. , Fernández J. , Caballero A. 
Published: December 2004

Abstract
We carried out an experiment of inbreeding and upward artificial selection for egg-to-adult viability in a recently captured population of Drosophila melanogaster, as well as computer simulations of the experimental design, in order to obtain information on the nature of genetic variation for this important fitness component. The inbreeding depression was linear with a rate of 0.70 ± 0.11% of the initial mean per 1% increase in inbreeding coefficient, and the realized heritability was 0.06 ± 0.07. We compared the empirical observations of inbreeding depression and selection response with computer simulations assuming a balance between the occurrence of partially recessive deleterious mutations and their elimination by selection. Our results suggest that a model assuming mutation-selection balance with realistic mutational parameters can explain the genetic variation for viability in the natural population studied. Several mutational models are incompatible with some observations and can be discarded. Mutational models assuming a low rate of mutations of large average effect and highly recessive gene action, and others assuming a high rate of mutations of small average effect and close to additive gene action, are compatible with all the observations.
Predation and the persistence of melanic male mosquitofish (Gambusia holbrooki)
Authors: Horth L. 
Published: December 2004

Abstract
The empirical reasons for the persistent rarity of a genotype are typically complex and tedious to identify, particularly in nature. Yet rare morphs occur in a substantial fraction of phenotypic polymorphisms. A colour polymorphism has persisted for decades in the eastern mosquitofish, yet why this is so remains obscure. Here, I report the results of (1) intensive sampling at 45 natural sites to obtain the frequency distribution of the melanic (black) mosquitofish morph in Florida, (2) predation trials, conducted independently in mesocosms, with three different predatory species and (3) two mark-recapture studies, conducted in nature. This work (1) documents the rarity of melanic mosquitofish in nature, (2) demonstrates that melanic males experience a selective advantage over silver males in the presence of predators, (3) indicates no difference in the colour morphs‘ survival at a natural site essentially devoid of these predators, although suggesting a higher rate of recapture for melanic males at a site rife with predators. Overall, selective predation appears to contribute to the persistence of the melanic morph, despite its rarity in nature.
Effect of thyroliberin on the course of experimental candidosis in mice
Authors: Błaszkowska J. , Pawlikowski M. , Komorowski J. , Kurnatowski P. 
Published: December 2004

SummaryThyroliberin (TRH) is one of the hormones, which affect immunologic processes. This hormone was studied in experimental subacute candidosis in mice. BALB/c males were given intraperitoneally single dose of Candida albicans cells (1 × 107 to 1 × 109 cfu of strain no. 244–33 ATCC). The animals from the experimental groups were injected subcutaneously, after 24 h from inoculation, dose of 10 μg TRH in 0.2 ml 0.9% NaCl, seven times at 24 h intervals. The control animals were given respectively 0.2 ml of physiologic NaCl solution. We have found that the examined hormone significantly decreases mortality in these animals (LD50C. albicans for mice treated with TRH was three times higher than that in the control groups), prolongs mean survival time for mice and decreases the intensity of fungal invasion of the animal organs.
Cryptococcal meningitis in two apparently immunocompetent Maltese patients
Authors: Vella Zahra L. , Mallia Azzopardi C. , Scott G. 
Published: December 2004

SummaryTwo cases of cryptococcal meningitis occurring in immunocompetent men are described. The first case involves a farmer in whom cryptococcal meningitis was rapidly diagnosed using direct microscopy, latex antigen tests and culture of cerebrospinal fluid (CSF). In the second case, initial mycological tests on CSF (direct microscopy and culture) were repetitively negative and latex antigen tests gave unconvincing results. The patient was started on triple antituberculosis therapy, on which he improved immediately; therapy was continued for 1 year with the patient remaining well. However, within 1 week of stopping therapy, he had to be readmitted with neurological signs and symptoms. Culture of CSF this time yielded Cryptococcus neoformans and the antigen test was consistently positive. These are the first reported cases of cryptococcal meningitis in immunocompetent patients in Malta.
Use of imidazole‐based eradication regimens for Helicobacter pylori should be abandoned in North India regardless of in vitro antibiotic sensitivity
Authors: BHATIA VIKRAM , AHUJA VINEET , DAS BIMAL , BAL CHANDRASEKHAR , SHARMA MAHESH P 
Published: December 2004

AbstractBackground and Aim:  The purpose of this study was to compare the efficacy of tinidazole‐ versus clarithromycin‐based triple regimens for eradication of Helicobacter pylori in North Indian patients of peptic ulcer disease, and to correlate the outcome with in vitro antibiotic susceptibility.Methods:  One hundred and forty‐six H. pylori‐infected patients with active ulcer were included in the prospective, randomized study. A total of 70 patients received lansoprazole 30 mg b.d., amoxycillin 1000 mg b.d. and tinidazole 500 mg b.d. (LAT), and 76 patients received lansoprazole 30 mg b.d., amoxycillin 1000 mg b.d. and clarithromycin 500 mg b.d. (LAC) for 14 days. The H. pylori status was assessed by urea breath test, rapid urease test, and histology and antibiotic sensitivity pattern by Epsilometer test.Results:  In per‐protocol analysis of 112 patients the H. pylori eradication rate was 42.3% (95% confidence interval (CI): 0.29–0.56) in LAT, and 64.8% (95%CI: 0.52–0.78) in LAC (95%CI of difference of proportions: 0.13–0.33, P = 0.01). Ulcer healed in 69.2% in the LAT group (95%CI: 0.57–0.82) and 81.7% in the LAC group (95%CI: 0.72–0.92; P = 0.02). Antibiotic susceptibility testing was done in 31 patients. Metronidazole resistance was present in 41.9% isolates but was unrelated to the outcome of the LAT regimen.Conclusion:  Imidazole‐based eradication regimens should be abandoned in North India regardless of in vitro susceptibility results.
Hepatitis B virus infection after renal transplantation in the presence of antibody to hepatitis B surface antigen immunity
Authors: KIM KYUN‐HWAN , AHN SANG HOON , CHUNG HYO YOUNG , PAIK YONG HAN , Lee KWAN SIK , KIM YU SEUN , CHON CHAE YOON , MOON YOUNG MYOUNG , HAN KWANG‐HYUB 
Published: December 2004

AbstractBackground and Aim: Hepatitis B virus (HBV) infection has been known to be hampered by immunity against hepatitis B surface antigen (HBsAg). However, HBV with mutations within the common antigenic epitope of HBsAg, the ‘a’ determinant region, can escape from humoral immunity. Moreover, HBV infection by ‘a’ determinant mutants in chronic HBV patients has been reported after renal transplantation. In the present study, the authors investigated HBV infection after renal transplantation despite passive immunization or resolved HBV infection.Methods: A total of 1682 patients who underwent a renal transplant between 1979 and 1998 at the Severance Hospital, Yonsei University College of Medicine, Korea, were enrolled. The sequence of the HBV genome was analyzed from two patients with antibody to HBsAg (anti‐HBs) immunity.Results: Of 1682 patients who were HBsAg negative before transplantation, 21 patients were found to be HBsAg positive, with elevated aspartate aminotransferase and alanine aminotransferase levels after transplantation. Interestingly, six of 21 (28.6%) patients were anti‐HBs positive before the transplantation. Sequence analysis of the cloned HBV from two of six patients with anti‐HBs immunity showed no evidence of significant mutations within the ‘a’ determinant region, suggesting a wild‐type of HBV. Their donors were not exposed to HBV before transplantation (all HBV markers were negative). Seven deaths of 21 patients were ascribed to HBV‐related complications.Conclusions: Regardless of anti‐HBs immunity, HBV infection occurred in immunosuppressed patients in a high endemic area. The molecular mechanism and clinical impact of HBV infection after renal transplantation in patients with anti‐HBs immunity should be further reappraised.© 2004 Blackwell Publishing Asia Pty Ltd
Optimal treatment strategy for elderly patients with hepatocellular carcinoma
Authors: DOHMEN KAZUFUMI , SHIRAHAMA MASAFUMI , SHIGEMATSU HIROHISA , IRIE KOJI , ISHIBASHI HIROMI 
Published: December 2004

AbstractBackground and Aims:  The age distribution of patients with hepatocellular carcinoma (HCC) now peaks at nearly 70 years in Japan and this is continually increasing. Whether such elderly patients with HCC aged 80 years or older should be treated, and if so, how they should be selected for treatment remains uncertain. The present study was undertaken to determine any differences in the clinical characteristics and prognostic features between patients with HCC aged 80 years or older and those younger than 80 years of age. We also aimed to identify any significant variables in the prognosis of elderly patients with HCC aged 80 years or older.Methods:  Seven hundred and four patients with HCC, diagnosed during a 12‐year period from January 1989 to December 2000, were categorized into two groups as follows: (i) 36 patients aged 80 years or older at the detection of HCC were defined as the elderly group and; (ii) 668 patients younger than 80 years of age were placed in the non‐elderly group. Clinical variables were analyzed and compared between the two groups, and any significant variables in the prognosis were simultaneously determined.Results:  Regarding sex, viral markers, concentration of serum alpha‐fetoprotein, diameter and number of tumors, Child's grade, presence of portal thrombosis, histology grade of HCC and any types of treatment, no significant difference was found between the two groups. The 1‐year and 3‐year survival rates in the elderly group (54.1 and 28.1%, respectively) were not significantly different from those in the non‐elderly group (69.9 and 43.2%, respectively; P = 0.1053). The only significant factor in the prognosis in the elderly group was the presence of portal thrombosis, although a Child's grade of B or C was almost a significant factor with a P‐value of 0.063. Tumor size measuring more than 3 cm in the greatest dimension, non‐solitary tumor, Child's grade of B or C, and the presence of portal thrombosis were all found to be prognostic factors in the non‐elderly group using a multivariate analysis.Conclusions:  An advanced stage of HCC, not advanced age, influenced the survival rate in these elderly patients. Therefore, an optimal treatment strategy should be applied for elderly patients with HCC who demonstrate less prognostic factors in the same manner as that for non‐elderly patients.© 2004 Blackwell Publishing Asia Pty Ltd
Reasons for creation of permanent ileostomy for the management of idiopathic chronic constipation
Authors: EL‐TAWIL AM 
Published: December 2004

AbstractThe aim of the present study was to examine the reasons for initiation of end ileostomy for management of intractable constipation over the last 35 years. A total of 62 patients with intractable constipation, on whom an end ileostomy was created during the period from 1966 to 2001, were recorded. The incidence of initiating a terminal ileostomy as a further surgical intervention to the total number of managed patients in examined studies varied from 2 to 25%. Preoperative unevaluated anal and rectal abnormalities formed the highest proportion compared with other reasons (65%, 40/62). A better understanding of the functional colonic and anorectal abnormalities may facilitate changes in surgical therapy.
Gastric emptying function changes in patients with thyroid cancer after withdrawal of thyroid hormone therapy
Authors: KAO PAN‐FU , LIN JEN‐DER , CHIU CHENG‐TANG , HSU HUI‐TING , SEE LAI‐CHU , TZEN KAI‐YUAN 
Published: December 2004

AbstractBackground: Hypothyroidism is commonly thought to cause decreased gastric emptying but is mostly associated with autoimmune disease. In the present study the gastric emptying function of thyroid cancer patients with severe hypothyroidism of short duration was evaluated with a radionuclide solid meal gastric emptying study.Methods: Twenty‐two patients who had undergone surgical operation and131I ablation for thyroid cancer participated in solid meal gastric emptying studies before the withdrawal of thyroxine and then again 4 weeks after the withdrawal of thyroxine. Eleven patients had an additional gastric emptying study at 6 weeks after withdrawal of thyroxine. Gastric emptying curves and emptying parameters were calculated. Student's pairedt‐test was used for statistical analysis of data for all cases between the baseline and at 4 weeks after withdrawal. An additional repeated measureanovawith multiple comparisons was performed on data between baseline, 4 weeks and 6 weeks after withdrawal for the other 11 patients. AllPvalues presented are two‐tailed and the significance level is 0.05.Results: Hypothyroidism status was confirmed by the marked change of the serum thyroxine and thyroid‐stimulating hormone 4 weeks and 6 weeks after withdrawal of the thyroxine replacement (P < 0.001). The gastric half‐emptying time and emptying rate changed significantly after short‐term severe thyroid hormone deficiency (P < 0.005). However, the length of the lag phase did not have a statistically significant change at 4 weeks or 6 weeks after withdrawal of the thyroxin replacement (P = 0.219 and 0.142).Conclusions: Hypothyroidism following the withdrawal of the thyroxine replacement in thyroid cancer patients preparing for131I cancer work‐up can significantly prolong gastric half‐emptying time and emptying rate.
Complement regulatory proteins in normal human esophagus and esophageal squamous cell carcinoma
Authors: SHIMO KIMIHIRO , MIZUNO MOTOWO , NASU JUNICHIROU , HIRAOKA SAKIKO , MAKIDONO CHIHO , OKAZAKI HIROAKI , YAMAMOTO KAZUHIDE , Okada Hiroyuki , Fujita Teizo , SHIRATORI YASUSHI 
Published: December 2004

AbstractBackground:  Altered expression of three complement regulatory proteins, decay‐accelerating factor (CD55), membrane cofactor protein (CD46) and homologous restriction factor 20 (CD59) has been identified in human gastrointestinal malignancies, but their expression in esophageal cancer has not been described. Therefore the purpose of the present paper was to study the distribution of these proteins in human normal and malignant esophageal mucosa.Methods and results:  In the normal esophageal mucosa, CD55 predominantly stained on the cell membrane of squamous epithelium in the superficial and prickle cell layers, whereas CD46 most intensely stained on the cell membrane in the basal and parabasal cell layers. In contrast to this reciprocal expression of CD55 and CD46, CD59 was broadly distributed on the cell membrane in all layers. In the esophageal squamous cell carcinoma, CD55 staining was intense in the stroma but was negligible in the cancer cells. In contrast, CD46 and CD59 stained almost uniformly on the tumor cell membrane. There was a significant difference in the intensity of the staining of CD55 and CD46 among cells in various layers of normal esophageal mucosa and esophageal carcinoma cells, but not in the staining of CD59. Similar expression patterns of the three complement regulatory proteins in carcinoma cells and in normal epithelium in the basal and parabasal cell layers were observed.Conclusions:  These observations on the expression of the three complement regulatory proteins would help understanding of the host immune responses involving the complement system against esophageal squamous cell carcinoma.
Genetic and phenotype changes following in vitro interactions between Helicobacter pylori strains
Authors: YAKOOB JAVED , FAN XUEGONG , HU GUOLING , ZHANG ZHENG 
Published: December 2004

AbstractBackground:  The purpose of the present paper was to determine whether in vitro interaction between different Helicobacter pylori strains leads to changes in antibiotic susceptibility, cagA, vacAM2 and DNA fingerprint patterns.Methods:  Three H. pylori strains with known antibiotic susceptibility, cagA, vacAM2 status and polymerase chain reaction–random amplified polymorphic DNA (PCR‐RAPD) fingerprint analysis were suspended in phosphate buffered saline (PBS pH 7.0), and the suspensions were mixed in equal proportion prior to culture on chocolate agar plates. Subcultures were performed five times every 3 days. As a control, each of the three strains was also subcultured separately. Antibiotic susceptibility testing, PCR for cagA, vacAM2 and PCR‐RAPD analysis were done.Results:  Surviving strain of the two H. pylori strains in each combination demonstrated change in resistance to both antibiotics but no change in sensitivity. CagA status of the surviving strain varied as compared to the vacAM2 status, which did not change. The PCR‐RAPD fingerprint showed unique band pattern.Conclusion:  DNA transformation follows in vitro interaction. Helicobacter pylori strain with antibiotic resistance is likely to dominate in such in vitro interactions between various strains.
High viral load is a risk factor for hepatocellular carcinoma in patients with chronic hepatitis B virus infection
Authors: OHATA KAZUYUKI , HAMASAKI KEISUKE , TORIYAMA KAN , ISHIKAWA HIROKI , NAKAO KAZUHIKO , EGUCHI KATSUMI 
Published: December 2004

AbstractBackground and Aims:  Hepatitis B virus (HBV) is considered a major risk factor for the progression to liver cirrhosis and hepatocellular carcinoma (HCC). The serum level of HBV‐DNA is correlated with progression of the disease. The aim of the present study was to determine the relationship between the level of HBV‐DNA and hepatocarcinogenesis in patients with chronic HBV infection.Methods:  The authors studied 73 patients who were diagnosed with chronic HBV infection at Nagasaki University Hospital (Nagasaki, Japan) between January 1980 and December 1999. The significance of age, sex, habitual drinking, serum alanine aminotransferase level, HBV viral load, interferon treatment, hepatic fibrosis and hepatic inflammation on the development of HCC were examined using univariate and multivariate analyses.Results:  The cumulative incidence rates of HCC were 14%, 29% and 48% at 5, 10 and 15 years after liver biopsy, respectively. Multivariate analysis identified high viral load, together with age and severe fibrosis, as independent and significant risk factors (P = 0.045, 0.047 and 0.013, respectively) for HCC.Conclusions:  The present findings indicate that high viral load is a risk factor for HCC in patients with chronic HBV infection. Patients with a high HBV viral load should be carefully monitored for HCC.
Cadherin/catenin complex appears to be intact in hepatocellular carcinomas from Australia and South Africa
Authors: HERATH NIRMITHA I , WALSH MICHAEL D , KEW MICHAEL C , YOUNG JOANNE , LEGGETT BARBARA A , MACDONALD GRAEME A 
Published: December 2004

AbstractBackground and Aim:  E‐cadherin binds to β‐catenin to form the cadherin/catenin complex required for strong cell adhesion. Inactivation of this complex in tumors facilitates invasion into surrounding tissues. Alterations of both proteins have been reported in hepatocellular carcinomas (HCC). However, the interactions between E‐cadherin and β‐catenin in HCC from different geographical groups have not been explored. The aim of the present study was to assess the role of E‐cadherin and β‐catenin in Australian and South African patients with HCC.Methods:  DNA was extracted from malignant and non‐malignant liver tissue from 37 Australian and 24 South African patients, and from histologically normal liver from 20 transplant donors. Chromosomal instability at 16q22, promoter methylation at E‐cadherin, β‐catenin mutations and E‐cadherin and β‐catenin protein expression was assessed using loss of heterozygosity, methylation‐specific polymerase chain reaction, denaturing high‐performance liquid chromatography and immunohistochemistry, respectively.Results:  Loss of heterozygosity at 16q22 was prevalent in South African HCC patients (50%vs 11%; P < 0.05, χ2). In contrast, E‐cadherin promoter hypermethylation was common in Australian cases in both malignant (30%vs 13%; P = not significant, χ2) and non‐malignant liver (57%vs 8%, respectively, P < 0.001, χ2). Methylation of non‐malignant liver was more likely to be detected in patients over the age of 50 years (P < 0.001, χ2), the overall mean age for our cohort of patients. Only one β‐catenin mutation was identified. E‐cadherin protein expression was reduced in one HCC, while abnormalities in protein expression were absent in β‐catenin.Conclusion:  Contrary to previous observations in HCC from other countries, neither E‐cadherin nor β‐catenin appears to play a role in hepatocarcinogenesis in Australian and South African patients with HCC.
Effects of pravastatin and bezafibrate on biliary lipid excretion and hepatic expression of Abcg5 and Abcg8 in the rat
Authors: KAMISAKO TOSHINORI , OGAWA HIROSHI 
Published: December 2004

AbstractBackground and Aim:  Multidrug resistance associated gene product 2 (Mdr2) is believed to have a significant role in biliary cholesterol and phospholipid secretions. Both pravastatin and bezafibrate resulted in Mdr2 induction, but increased cholesterol secretion was observed only in pravastatin treatment. To explore the mechanism, the hepatic expression of genes that are responsible for the metabolism of the lipids was studied.Methods:  Rats were divided into three experimental groups: (i) the control group; (ii) the bezafibrate group, which was fed a diet containing 0.45% bezafibrate for 5 days; and (iii) the pravastatin group, which was fed a diet containing 0.1% pravastatin for 5 days. Serum, hepatic and biliary lipids were measured by colorimetric assays and hepatic mRNA related to lipid metabolism was studied by reverse transcription–polymerase chain reaction (RT‐PCR).Results:  In the bezafibrate group biliary phospholipid secretion was increased although cholesterol secretion was not increased. In the pravastatin group, biliary cholesterol and phospholipid secretions were significantly increased. The biliary cholesterol/phospholipid ratio was decreased in the bezafibrate group, but the ratio did not change in the pravastatin group. Hepatic Mdr2, Abcg5 and Abcg8 mRNA expression was remarkably increased in the pravastatin group in comparison with the control group (184%, 264% and 247% of control value, respectively). In the bezafibrate group the hepatic gene expression of Mdr2 was increased (157% of control value), but there were no significant changes in hepatic Abcg5 and Abcg8 mRNA expression compared with the control group.Conclusions:  Compared with Mdr2, Abcg5 and Abcg8 seem to be more essential transporters for biliary secretion of cholesterol. Pravastatin upregulated Abcg5/Abcg8 while bezafibrate did not, which appears to explain the different effects of these compounds on biliary lipid secretion.© 2004 Blackwell Publishing Asia Pty Ltd