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71.
Yechiel Becker Eynath Tabor Yael Asher Irit Davidson Mertyn Malkinson R. L. Witter 《Virus genes》1993,7(3):277-287
A radioactive PCR test was developed that amplified the very virulent Marek's disease virus-1 (vvMDV-1) DNA sequence containing the 132 bp repeats. In apathogenic MDV-1 (CVI 988, Rispens), amplified DNA bands containing multiple copies of 132 bp repeats were identified. In the present study this PCR technique was used to monitor the passage level of vvMDV-1 in chicken embryo fibroblasts (CEF) in which the number of tandem 132 bp repeats was increased. It was found that at passage level 32 of vvMDV-1-B isolate, the 132 bp tandem repeat was already markedly amplified and its pattern resembled that of the MDV-1 (CVI 988, Rispens) vaccine virus DNA. In the vvMDV-1Z strain, amplification of the 132 bp repeat was not detectable at a similar passage level. The PCR test demonstrated that the apathogenic MDV-1 Md11/75c virus developed by extensive in vitro passaging has amplified 132 bp DNA repeats similar to those of the commercial vaccine virus (CVI 988, Rispense). It was also found that the pattern of viral RNA from infected cells detectable by Northern blot hybridization was markedly changed from a 2.4 kb RNA species in cells infected with vvMDV-1 viruses, to four RNA species (ranging from 2.2 to 4.4 kb) in cells infected with passage 32 of MDV-1-B strain, to a very large number of undefined RNA species synthesized in cells infected with attenuated MDV-1 viruses (CVI 988, Rispens and Md 11/75c). 相似文献
72.
Expression of CD44 in effusions of patients diagnosed with serous ovarian carcinoma – diagnostic and prognostic implications 总被引:2,自引:0,他引:2
Berner HS Davidson B Berner A Risberg B Kristensen GB Trope CG Van de Putte G Nesland JM 《Clinical & experimental metastasis》2000,18(2):197-202
CD44 is a family of cell adhesion molecules involved in a variety of cellular functions. The present study analysed the expression
of two CD44 isoforms in serous effusions of patients diagnosed with ovarian carcinoma and corresponding primary and metastatic
lesions. Fifty-eight effusions, 23 primary ovarian tumours, and 44 metastatic lesions were studied for protein expression
of CD44s and v3-10 using immunohistochemistry. Results were correlated with clinical parameters. CD44v3-10 was seen in carcinoma
cells in the majority of cases at all sites. Malignant effusions showed an up-regulation of CD44s compared to both primary
tumours and metastatic solid lesions. Mesothelial cells frequently expressed CD44s, but were rarely immunoreactive for v3-10.
CD44s immunoreactivity in cancer cells in effusions was significantly more often observed in patients with FIGO stage 3 than
in stage 4 patients (P = 0.045). Staining results did not correlate with age, effusion site, metastatic site, tumour grade or residual tumour mass
after initial surgery. Likewise, comparison of overall and disease-free survival with expression of the CD44 isoforms studied
did not reveal any statistically significant associations. The up-regulation in CD44 levels in effusions, primarily in stage
3 disease, suggests that adhesion of ovarian carcinoma cells to mesothelium may be regulated at the level of CD44s expression,
and provides further evidence of phenotypic alteration in the transition from primary tumour cell clones to effusions. The
similar expression profile of CD44 in carcinoma cells in peritoneal and pleural effusions supports our previous observations
and the hypothesis that carcinoma cells in peritoneal effusions are truly metastatic.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
73.
AIMS: Previous studies investigating the link between infection with Borrelia burgdorferi and morphoea have produced conflicting results. Often, these studies have been undertaken in patients from different regions or countries, and using methods of varying sensitivity for detecting Borrelia burgdorferi infection. This study aimed to establish whether a relation could be demonstrated in the Highlands of Scotland, an area with endemic Lyme disease, with the use of a sensitive method for detecting the organism. METHODS: The study was performed on biopsies of lesional skin taken from 16 patients from the Highlands of Scotland with typical clinical features of morphoea. After histological confirmation of the diagnosis, a nested polymerase chain reaction (PCR) using primers to a unique conserved region of the Borrelia burgdorferi flagellin gene was performed on DNA extracts from each biopsy. A literature search was also performed for comparable studies. RESULTS: None of the 16 patients had documented clinical evidence of previous infection with B burgdorferi. DNA was successfully extracted from 14 of the 16 cases but all of these were negative using PCR for B burgdorferi specific DNA, despite successful amplification of appropriate positive controls in every test. The results were compared with those of other documented studies. CONCLUSIONS: Examination of the literature suggests that there is a strong geographical relation between B burgdorferi and morphoea. These results, in which no such association was found, indicate that morphoea may not be associated with the subspecies of B burgdorferi found in the Highlands of Scotland. 相似文献
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BACKGROUND: Several examinations have detected a relation between depressive symptoms and medical utilization. However, selection biases have been involved in most previous examinations. We sought to test the association between depressive symptoms and prospective, increased medical care utilization, in a population-based Canadian sample, while controlling for utilization due to medical illness and controlling for selection bias. METHODS: Data from the Nova Scotia Health Survey 1995, an age- and sex-stratified random sampling of 3227 Nova Scotian adults, included the Center for Epidemiological Studies-Depression scale and items assessing chronic medical conditions and current limitations in daily activities resulting from medical illness. We linked survey data with medical care utilization measures for the year following the survey, including out-patient visits, reimbursement for out-patient services, hospitalizations, and hospitalization days. RESULTS: After controlling for age, sex, count of medical diagnoses and current medical severity, those with a greater level of depressive symptoms were at greater risk of having increased medical care utilization in the following year. These results remained after removing mental health care utilization costs. CONCLUSIONS: In a population-based sample, depressive symptoms predicted greater medical care utilization, independent of a number of medical severity measures. Whether depressive symptoms are a risk marker or a causal risk factor for increased medical utilization remains to be explored. 相似文献
79.
This study was designed to assess the serum and mucosal immune response to naturally acquired rotavirus enteritis in children. Serum and duodenal secretions were collected 1 week and again 4 to 5 weeks after the onset of illness from 10 children. In two of these children, the procedure was repeated 12 to 15 months later. Another 10 children with bacterial enteritis were studied as controls. The antibody response in serum included a significant elevation of rotavirus-specific immunoglobulin M (IgM) in acute-phase samples (P less than 0.05), but not in convalescent-phase samples, when compared with controls. Rotavirus-specific IgG and IgA levels were significantly elevated in convalescent-phase serum when compared with acute-phase serum (P less than 0.025), but not in control serum. Rotavirus-specific IgA levels in convalescent duodenal secretions were significantly raised when compared with both acute-phase and control samples (P less than 0.01). Rotavirus-specific IgM levels were elevated in acute-phase duodenal secretions (P less than 0.05), but not in convalescent-phase secretions. In two children, the secretory IgA response had disappeared by 12 months. These studies demonstrate the presence of rotavirus-specific antibody in duodenal secretions which may be important for protection against reinfection and may be capable of being stimulated by oral vaccination. 相似文献
80.
Effects of flanking base sequences on 5-bromodeoxyuridine mutagenesis in mammalian cells 总被引:2,自引:0,他引:2
The molecular mechanisms of incorporation-dependent, 5-bromodeoxyuridine (BrdU)-induced mutagenesis were analyzed in murine A9 cells that possess a single copy of theEscherchia coli gpt gene integrated into the chromosomal DNA as part of a shuttle vector. Four independently derived GPT– mutants with single base changes within the integratedgpt gene were utilized in BrdU-induced reversion analyses to test the relative mutability of guanine residues in four different settings: the 5 and 3 guanine residues of a GG doublet, the 3 guanine residue of a GGGG quartet, and the middle guanine residue of a GGG triplet. Two of the mutant lines possessed GG doublet sequences in which a GCAT transition at either guanine residue of the doublet leads to restoration of GPT enzyme activity without restoring wild-type DNA sequence. Both lines were shown to be effectively reverted by BrdU incorporation-dependent mutagenesis, and sequencing of thegpt genes from numerous independently derived revertants of both lines demonstrated that greater than 90% of the revertants arose due to GCAT transitions at the 3 guanine residue of the doublet. BrdU-induced reversion of two additional GPT– mutant lines demonstrated that the 3 guanine residue of a GGGG quartet is efficiently mutated, while the middle guanine residue of a GGG triplet sequence is at least 10-fold less mutable by BrdU incorporation-dependent mutagenesis than the 3 guanine residue of a GG doublet or GGGG quartet. All four mutant lines tested were equally revertible by treatment with the alkylating agent ethyl methane sulfonate. The results from this study define a sequence-specific mechanism for BrdU-induced, incorporation-dependent mutagenesis and demonstrate the use of reversion analysis for the determination of sequence specific effects at precise sites within a gene. 相似文献