Translocation (6;8)(q22;q12) in Ph+ chronic myelocytic leukemia.
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Adult↗
Biomedical subjects
M Schmid
Publications and source records attributed to M Schmid.
[Heterosexual transmission of hepatitis-C virus].
Parenteral transmission of hepatitis C virus (HCV) through blood transfusions and intravenous drug misuse is well established. Since 50% of patients with hepatitis C have no history of parenteral exposure, other ways of transmission must exist. The purpose of this study was to examine the epidemiological importance of heterosexual intercourse for transmission of HCV infection. 29 heterosexual contacts (13 men, 16 women, mean age 47 years) of 29 index patients (16 men, 13 women, mean age 49 years) with histologically und serologically documented chronic hepatitis C were questioned about parenteral exposure and sexual behaviour. Their serum samples were examined for ALT activity and anti-HCV antibodies (first-generation Ortho-HCV-ELISA). Five contacts were using condoms to prevent infection. Five of 24 contacts (21%) practising unprotected sexual intercourse, but none of 5 contacts using condoms, showed evidence of heterosexual HCV transmission: 4 were anti-HCV positive (one with elevated ALT activity) and another showed elevated ALT activity with a negative anti-HCV test. None of these contacts had a history of parenteral exposure. Our results indicate that heterosexual transmission of HCV is epidemiologically important. The true rate of infection may be even higher, for two reasons: (1) not every HCV infection is detected by the anti-HCV test, and (2) the anti-HCV test may turn negative again in uncomplicated infection.
Adult↗
[Second generation hepatitis-C virus test and polymerase chain reaction in anti-C 100 negative patients with chronic non-A, non-B hepatitis].
The aim of our study was to evaluate whether a negative HCV test of the first generation (HCV-ELISA 1) using the antigen C100-3 excludes chronic HCV infection, or whether patients exist who are negative for antibodies to C100-3 in spite of chronic hepatitis C. 27 patients with histologically proven chronic non-A, non-B hepatitis, all of whom were HCV-ELISA 1 negative, were tested by the HCV test systems of the second generation (Ortho-HCV-ELISA 2 and Chiron-HCV-RIBA 2) based on the distinct HCV antigens 5-1-1, C100-3, C33c and C22-3. To determine the presence of viremia, serum samples were also tested for HCV-RNA with "nested" PCR. 10 of 27 patients proved to be persistently negative when tested with the second generation assays. One patient showed low grade reactivity by HCV-ELISA 2, but non-reactivity by HCV-RIBA 2. In none of these 11 patients was HCV-RNA detected. 16 (60%) of 27 patients negative with HCV-ELISA 1 were positive with HCV-ELISA 2. HCV-RIBA 2 detected antibodies to the structural core antigen C22-3 in all of these 16 patients and antibodies to the non-structural antigen C33c in 14 of them, while antibodies to 5-1-1 or C100-3 were not found in any of these cases. 10 (63%) of the 16 HCV-ELISA 1 negative, but HCV-ELISA 2 and HCV-RIBA 2 positive patients were positive for HCV-RNA by "nested" PCR.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
[Hepatitis-C virus and hepatoma].
To clarify the relationship between hepatitis C virus (HCV) infection and hepatocellular carcinoma (HCC), frozen serum samples from 213 patients with histologically proven liver cirrhosis alone (96 alcoholics, 59 HBsAg positive, 29 non-A, non-B hepatitis, 29 cryptogenic) and 40 patients with liver cirrhosis and HCC (12 alcoholics, 7 HBsAg positive, 7 non-A, non-B hepatitis, 14 cryptogenic) were analyzed for antibodies to hepatitis C virus (anti-HCV) with the ortho-HCV-ELISA. The results were as follows. 50 of 253 (20%) patients were anti-HCV positive. The prevalence of anti-HCV was significantly higher in patients with HCC than in patients without HCC (14 of 40 [35%] vs 36 of 213 [17%]; p less than 0.001). In anti-HCV-positive patients HCC were significantly more frequent than in anti-HCV-negative patients (14 of 50 [28%] vs 26 of 203 [13%]; p less than 0.001). The significantly higher occurrence of HCC in anti-HCV-positive patients was not related to other known risk factors such as alcoholism or chronic hepatitis B virus (HBV) infection. Patients with HCV infection as the only risk factor also had a significantly higher occurrence of HCC (12 of 38 [32%] vs 26 of 203 [13%]; p less than 0.001). Our data suggest that chronic HCV infection plays an important role in the pathogenesis of HCC, in particular in patients with cirrhosis unrelated to alcohol or HBV infection.
Aged↗
[Anti-HCV test in patients with chronic non-A, non-B hepatitis].
Our study was designed to evaluate the clinical significance of the ELISA-anti-HCV test. 90 patients with histologically proven chronic non-A, non-B hepatitis (NANBH) and a control group consisting of 36 patients with primary biliary cirrhosis (PBC) were analyzed for antibodies to hepatitis C virus (anti-HCV). Frozen serum samples were tested with the ortho-HCV-ELISA. 67 of 90 (74%) patients with chronic NANBH showed antibodies to the hepatitis C virus. The prevalence of anti-HCV in patients with parenterally transmitted and sporadic chronic NANBH was 70% (23 of 33) and 77% (44 of 57) and in patients with chronic active and chronic persistent NANBH 73% (27 of 37) and 76% (40 of 53) respectively. No significant difference in the prevalence of anti-HCV in the 4 subgroups of patients with chronic NANBH was found. 2 of 36 patients (6%) with PBC were anti-HCV positive without evidence of previous HCV infection. Our results bear out the experience of other authors, that HCV is the commonest pathogen of chronic NANBH. The low prevalence of anti-HCV in patients with PBC suggests good specificity. There have been reports in the literature of "false positive results", particularly in autoimmune hepatitis, and it has been shown that borderline positive test results are often unspecific and therefore to be interpreted with care.
Adult↗
Increased surface expression of a newly identified 150-kDa dimer early after human T lymphocyte activation.
Lymphocyte activation induces or increases the expression of several surface structures, some of which are directly involved in cell growth such as receptors for IL-2 or transferrin. In order to identify new structures characteristic of activated lymphocytes, we developed a series of mAb against functionally defined human T cell clones. In the present study we report the isolation of a mAb termed BB18 recognizing, at the cell surface, a novel 150-kDa glycoprotein dimer whose expression on T lymphocytes increases readily after their activation with various stimuli including lectins. In contrast, in the presence of PMA, cell-surface expression of this 150-kDa structure is down-regulated even earlier than CD3 molecules. Biochemical studies as well as phenotypic analysis revealed that this structure is different from all previously identified molecules on the lymphocyte cell surface. Furthermore, functional studies showed that triggering this disulfide-linked dimer through BB18 epitope in the presence of submitogenic concentrations of PMA induced strong lymphocyte proliferation. This proliferative response require E+ cells and accessory cells, and this even after immobilization of BB18 mAb.
Animals↗
The CD39 molecule defines distinct cytotoxic subsets within alloactivated human CD8-positive cells.
Lymphocyte activation induces or increases the expression of several surface structures, none of which is characteristic of an activated cell subset. In particular, structures such as CD45RO, CD25, CD26, CD49b, CD54, CD71 are expressed by the vast majority of lymphocytes at various times following in vitro activation. CD39 molecules were originally identified on activated B lymphocytes and have recently been described on activated T cell clones. In the present report, we have characterized phenotypically and functionally defined cell subsets generated during an in vitro allostimulation. Results indicated that the percentage of CD39+ cells reached a maximum at day 6 and remained stable thereafter. We demonstrate that CD39 expression allows the identification within the allosensitized CD8+ cytotoxic cells of distinct subsets of cells mediating allo cytotoxic T lymphocyte or natural killer (NK)-like reactivity. More precisely, CD8+CD39+ alloactivated cells mainly mediate specific killer activity, whereas CD8+CD39- alloactivated cells predominantly exhibit NK-like reactivity. Further, we show a high functional correlation associated with the lack of CD39 expression on NK-like alloactivated CD8+ cells, while there is no association with CD56 or CD57 NK-associated structures.
Adenosine Triphosphatases↗
Detection of hepatitis C viraemia in Caucasian patients with hepatocellular carcinoma.
Potential risk factors for the development of hepatocellular carcinoma were analysed in 40 Caucasian patients with this malignancy. A higher proportion (14 of 40; 35%) had evidence of hepatitis C virus (HCV) infection than had evidence of either hepatitis B virus (HBV) carriage (17.5%) or alcohol abuse (30%). In all 14 patients whose sera were reactive by HCV ELISA (Ortho second generation test), the presence of antibodies to HCV were confirmed by recombinant immunoblot assay (Ortho RIBA-2). Furthermore, two independent laboratories detected HCV-RNA in 10 of the 14 (71%) anti-HCV positive sera. Two additional sera were shown to contain HCV-RNA when reanalysed by a modified PCR using oligonucleotide primers designed to amplify a shorter fragment of the 5' noncoding region of the genome. Seven of the anti-HCV positive patients also had evidence of prior HBV infection and 2 admitted to alcohol abuse. HCV infection was the only identifiable risk factor in 6 patients. These data confirm the association between HCV infection and hepatocellular carcinoma and suggest that persistent viral replication accompanies tumour development in the majority of patients whose serum contains anti-HCV.
Aged↗
A 47,XXY female with unusual genitalia.
A 47,XXY karyotype was found in a 6-year-old girl. The patient had female external genitalia, clitoromegaly, remnants of the ductus mesonephricus, uterus, and gonads in the labia majora which were determined to be testes by histology. Cytogenetic and DNA analyses suggest that the Y chromosome had a normal structure and that both X chromosomes were of maternal origin. The unusual clinical findings in the patient are discussed.
Adult↗
Fragile site (16) (q22). III. Segregation analysis.
The rare autosomal fragile site, fra (16) (q22), is the most common of all rare autosomal fragile sites and has a heterozygote frequency of about 5%. Evidence for it was found following the segregation expected from a simple codominant trait with complete penetrance; this is in contrast to a variety of other rare autosomal fragile sites. Based on the analysis of 12 families in which fra (16) (q22) is segregating, we found that, whereas complete penetrance could be confirmed, the transmitting parent was significantly more likely to be of the female sex. On the other hand, there was no evidence for preferential transmission to offspring of either sex.
Chromosome Fragile Sites↗
Chromosome banding in Amphibia. XVII. First demonstration of multiple sex chromosomes in amphibians: Eleutherodactylus maussi (Anura, leptodactylidae).
A cytogenetic study performed on a population of the South American leptodactylid frog Eleutherodactylus maussi revealed multiple sex chromosomes of the X1X1X2X2 female/X1X2Y male (= XXAA female/XXAY male) type. The diploid chromosome number is 2n = 36 in all females and 2n = 35 in most males. The multiple sex chromosomes originated by a centric fusion between the original Y chromosome and a large autosome. In male meiosis the X1X2Y (= XXAY) multiple sex chromosomes form a classical trivalent configuration. E. maussi is the first species discovered in the class Amphibia that is distinguished by a system of multiple sex chromosomes. Only one single male was found in the population with 2n = 36 chromosomes and lacking the Y-autosomal fusion. This karyotype (XYAA male) is interpreted as the ancestral condition, preceding the occurrence of the Y-autosome fusion.
Animals↗
Early stages of sex chromosome differentiation in fish as analysed by simple repetitive DNA sequences.
Animal sex chromosome evolution has started on different occasions with a homologous pair of autosomes leading to morphologically differentiated gonosomes. In contrast to other vertebrate classes, among fishes cytologically demonstrable sex chromosomes are rare. In reptiles, certain motifs of simple tandemly repeated DNA sequences like (gata)n/(gaca)m are associated with the constitutive heterochromatin of sex chromosomes. In this study a panel of simple repetitive sequence probes was hybridized to restriction enzyme digested genomic DNA of poeciliid fishes. Apparent male heterogamety previously established by genetic experiments in Poecilia reticulata (guppy) was correlated with male-specific hybridization using the (GACA)4 probe. The (GATA)4 oligonucleotide identifies certain male guppies by a Y chromosomal polymorphism in the outbred population. In contrast none of the genetically defined heterogametic situations in Xiphophorus could be verified consistently using the collection of simple repetitive sequence probes. Only individuals from particular populations produced sex-specific patterns of hybridization with (GATA)4. Additional poeciliid species (P. sphenops, P. velifera) harbour different sex-specifically organized simple repeat motifs. The observed sex-specific hybridization patterns were substantiated by banding analyses of the karyotypes and by in situ hybridization using the (GACA)4 probe.
Animals↗
Polymerase chain reaction detects hepatitis B virus DNA in paraffin-embedded liver tissue from patients sero- and histo-negative for active hepatitis B.
The polymerase chain reaction (PCR) was used to analyse tissues from paraffin blocks of liver needle biopsies retrospectively. Biopsies of 29 patients with proven HBsAg and HBcAg expression in liver tissue and of 8 healthy volunteers served as positive (group 1) and negative tissue controls (group 2), respectively. These were compared with 16 patients with proven HBsAg expression in liver but lack of HBcAg (group 3), with 23 patients with anti-HBc as the only hepatitis B virus (HBV)-related marker (group 4) and with 21 patients with liver disease and without HBV markers in tissue or serum (group 5). PCR detected HBV sequences in all cases of the positive control group and in 94% of group 3, in 65% of group 4, and in 71.4% of group 5, whereas all healthy volunteers were negative. Our data show that PCR is able to detect HBV-DNA sequences in virtually all patients with active viral antigen expression but also in a high proportion of hepatitic patients who are silent for active HB but may or may not show signs of a contact with the HBV. Thus, PCR for HBV-DNA in paraffin sections might become a useful tool for identifying patients carrying HBV-DNA but not expressing HBV antigens.
Base Sequence↗
Characterization of centromere arrangements and test for random distribution in G0, G1, S, G2, G1, and early S' phase in human lymphocytes.
The arrangement of centromeres, cluster formation and association with the nucleolus and the nuclear membrane were characterized in human lymphocytes during the course of interphase in a cell-phase-dependent manner. We evaluated 3,893 cell nuclei categorized by five parameters. The centromeres were visualized by means of indirect immunofluorescent labeling with anti-centromere antibodies (ACA) contained in serum of patients with CREST syndrome. The cell nuclei were classified as G0, G1, S, G2, G1' and early S' phase by comparing microscopically identified groups of cell nuclei with flow cytometric determination of cell cycle stage of synchronized and unsynchronized lymphocyte cell cultures. Based on a discrimination analysis, a program was devised that calculated the probability for any cell nucleus belonging to the G0, G1, S, G2, G1' and early S' phase using only two microscopic parameters. Various characteristics were determined in the G0, S, and G2 stages. A transition stage to S phase within G1 was detected. This stage shows centromere arrangements not repeated in later cell cycles and which develop from the dissolution of centromere clusters in the periphery of the nucleus during G0 and G1. S phase exhibits various non-random centromere arrangements and associations of centromeres with the nucleolus. G1' and early S' phase of the second cell cycle display no characteristic centromere arrangement. The duplication of centromeres in G2 is asynchronous in two phases. For all cell phases a test for random distribution of the centromeres in the cell nucleus was performed. There is a distinct tendency for centromeres to be in a peripheral position during G0 and G1; this tendency becomes weaker in S phase. Although the visual impression is a seemingly random distribution of centromeres in G2 and G1', statistical analysis still demonstrates a significant deviation from random distribution in favor of a peripheral location. Only the early S phase of the second cell cycle shows no significant deviation from a random distribution.
Cell Cycle↗
In situ mapping of the chicken progesterone receptor gene and the ovalbumin gene.
The chicken progesterone receptor (cPR) gene and the ovalbumin (OA) gene, a target of cPR regulation, have been mapped via fluorescent in situ hybridization to the two largest chromosomes of the chicken karyotype. cPR is subtelomeric on the long arm of chromosome 1 and OA is on the long arm of chromosome 2, close to the centromere. A 35-kb cosmid probe for the cPR gene and two genomic fragments of 9.2 and 15 kb for the OA gene were biotin-labeled for nonradioactive localization of the two chicken loci.
Animals↗
A human moderately repeated Y-specific DNA sequence is evolutionarily conserved in the Y chromosome of the great apes.
Evolutionary conservation of the human-derived moderately repeated Y-specific DNA sequence Y-190 (DYZ5) was investigated in the chimpanzee, orangutan, and gorilla. Southern blot analysis showed the presence of the sequence in the Y chromosome of all great apes. Pulsed-field gel electrophoresis and in situ hybridization revealed that the repeat is organized in one major block and confined to a small region of the Y chromosome of the three species. DYZ5 was assigned to the proximal short arm of the Y chromosome of the chimpanzee and orangutan and to the long arm of the Y chromosome of the gorilla. In light of its evolutionary conservation, DYZ5 may have an as yet undetermined structural function in the Y chromosome.
Animals↗
Mapping the beta NGF gene in situ to a microchromosome in chicken.
The chicken nerve growth factor (beta NGF) gene has been mapped by fluorescent in situ hybridization to a pair of microchromosomes, confirming previous reports of the existence of a single gene locus. A 39-kb genomic fragment cloned in a cosmid vector and including the 5' end of the beta NGF locus was biotinylated for nonradioactive detection of the gene. This report adds to the increasing evidence proving microchromosomal localization of highly conserved and biologically fundamental genes. The implications of such genes belonging to very small linkage groups for the transmission of alleles from generation to generation together with the relevance of nonisotopic in situ hybridization for avian gene mapping are considered.
Animals↗
An intriguing Y chromosome in Heteromys anomalus (Rodentia, Heteromyidae).
The mitotic chromosomes of the pocket mouse Heteromys anomalus (Rodentia, Heteromyidae) from Venezuela were analyzed by means of conventional staining and various banding techniques. The karyotype of this species is distinguished by a Y chromosome with exceptional banding properties. The very large heterochromatic Y long arm shows a remarkable bright quinacrine fluorescence, but only moderate or dull fluorescence when labeled with other AT base pair-specific fluorochromes. The implications of these findings are discussed.
Animals↗