Search PubMed⌕ Search

Biomedical subjects

M Thomas

Publications and source records attributed to M Thomas.

At least 469 records · Page 26Linked to original sources
PubMed1995

Delayed effects of exposure to organophosphorus compounds.

In a group of 34 industrial workers, chronically exposed to organophosphorus (OP) compounds, serum pseudocholinesterase activity was depressed significantly in the exposed group as compared to the control group. There was a significantly higher incidence of peripheral neuropathy among the workers exposed to OP compounds, as compared to the control group. Mild to profound sensorineural hearing deficits were detected in both the exposed and control groups. As the pre-exposure hearing status of the workers was not known and since many other factors can also cause pathological changes in the cochlear nerve, a definite conclusion about the ototoxic nature of the OP compounds could not be drawn.

Adult↗
PubMed1995

Serotonergic mechanisms and current and future psychiatric practice.

The participation of serotonin (5-HT) in the regulation of diverse biological and psychological functions makes it possible for medications acting on 5-HT subsystems to play a role in the treatment of a growing number of psychiatric and medical disorders. The actions of new medications on the 5-HT reuptake mechanism are complemented by actions on the 5-HT receptors and on other neurotransmitter systems that may be effective in complex and treatment-resistant syndromes. New drugs acting on one or more of the seven major 5-HT receptor classes that have been identified thus far appear to be promising for the treatment of specific subtypes of psychiatric syndromes, from depression to anxiety to schizophrenia. A given serotonergic medication may be useful for more than one disorder because it acts on specific dimensions of psychobiological malfunction that characterize more than one disorder, dimensions that are mediated by more than one receptor.

Anxiety Disorders↗
PubMed1994

Gene density and organization in a small region of the Arabidopsis thaliana genome.

We have characterized a 6.4 kb genomic fragment from Arabidopsis thaliana ecotype Columbia overlapping the 5' end of the AKin10 gene which encodes a protein Ser/Thr kinase. Using, as probes, various restriction fragments located upstream of AKin10, two cDNA clones have been isolated from a cDNA library prepared from young shoot tissue. A comparison between the cDNA and the above genomic sequences allowed us to locate two novel genes, Atcys1 and Athyp1 (for Arabidopsis thaliana cystathionine gamma-synthase 1 and hypothetical protein 1). The coding sequences of both genes are interrupted by introns and the exons match the sequences of the corresponding cDNAs. Further analysis of the genomic fragment revealed the presence of an open reading frame (ORF) of 609 nucleotides situated between the two genes. Atcys1, Athyp1, AKin10 and the ORF are very close to each other and organized in the same polarity; hence, the intergenic regions probably contain, within less than 0.5 kb, all the regulatory elements necessary to govern initiation and termination of transcription. The deduced protein sequence of Atcys1 shows a high degree of similarity with the cystathionine gamma-synthase from Escherichia coli. The putative product of the Athyp1 gene contains seven hydrophobic regions flanked by hydrophilic domains, reminiscent of membrane-spanning proteins. Southern blot hybridization experiments suggest the presence of one copy of Atcys1, Athyp1 and AKin10 per haploid genome, and Northern blot analysis demonstrates that the three genes are differentially expressed in roots, shoots and leaves.

Arabidopsis↗
PubMed1994

Linkage analysis of a candidate locus (HLA) in autosomal dominant sacral defect with anterior meningocele.

Sacral defect with anterior meningocele (SDAM) is a type of caudal dysgenesis. It is present at birth and becomes symptomatic later in life, usually because of obstructive labor in females, chronic constipation, rectal fistula and abscess, or meningitis. The inheritance is autosomal dominant. HLA has been implicated in caudal dysgenesis because of analogy with disorders of the T-locus complex, a tail length determining gene in mice which is linked to the major histocompatibility complex, H-2. Members of a 5-generation family with sacral defect and anterior meningocele (SDAM) were typed with polymorphic markers (dinucleotide repeats D6S89, D6S105, D6S109, and TCTE1) linked to HLA. Two-point and multipoint analysis exclude the HLA region as the location for the SDAM gene in this family.

Abnormalities, Multiple↗
PubMed1994

Immunohistochemical Detection of p53 and c-erbB-2 Proteins: Prognostic Significance in Operable Breast Cancer.

We examined the associations of p53 expression and/or c-erbB-2 expression with Ag-NOR counts and clinicopathologic variables in 111 breast cancer patients, and assessed whether expression of either p53or c-erbB-2 would be useful prognostic indicators. There was no significant association between p53 expression and c-erbB-2 expression, but p53 expression and c-erbB-2 expression, especially in combination, were shown to be significantly associated with Ag-NOR counts and axillary lymph node metastasis. Although p53 expression and c-erbB-2 expression were significant prognostic factors by univariate analysis, they did not appear to be independent prognostic factors by multivariate analysis, in which nodal status was introduced using the Cox model. When nodal status was excluded from the model, however, concurrent p53 and c-erbB-2 expression did have a significant prognostic value. Therefore, it was suggested that concurrent p53 and c-erbB-2 expression provides valuable prognostic information for breast cancer patients in whom axillary lymph node dissection has not been performed.

Journal Article↗
PubMed1994

Genetic marking shows that Ph+ cells present in autologous transplants of chronic myelogenous leukemia (CML) contribute to relapse after autologous bone marrow in CML.

Relapse after autologous bone marrow transplantation for chronic myelogenous leukemia (CML) can be due either to the persistence of leukemia cells in systemic tissues following preparative therapy, or due to the persistence of leukemia cells in the autologous marrow used to restore marrow function after intensive therapy. To help distinguish between these two possible causes of relapse, we used safety-modified retroviruses, which contain the bacterial resistance gene NEO, to mark autologous marrow cells that had been collected from patients early in the phase of hematopoietic recovery after in vivo chemotherapy. The cells were then subjected to ex vivo CD34 selection following collection and 30% of the bone marrow were exposed to a safety-modified virus. This marrow was infused after delivery of systemic therapy, which consisted of total body irradiation (1,020 cGy), cyclophosphamide (120 mg/kg), and VP-16 (750 mg/m2). RT PCR assays specific for the bacterial NEO mRNA, which was coded for by the virus, and the bcr-abl mRNA showed that in two evaluable CML patients transplanted with marked cells, sufficient numbers of leukemia cells remained in the infused marrow to contribute to systemic relapse. In addition, both normal and leukemic cells positive for the retroviral transgenome persisted in the systemic circulation of the patients for at least 280 days posttransplant showing that the infused marrow was responsible for the return of hematopoiesis following the preparative therapy. This observation shows that it is possible to use a replication-incompetent safety-modified retrovirus in order to introduce DNA sequences into the hematopoietic cells of patients undergoing autologous bone marrow transplantation. Moreover, this data suggested that additional fractionation procedures will be necessary to reduce the probability of relapse after bone marrow transplantation in at least the advanced stages of the disease in CML patients undergoing autologous bone marrow transplantation procedures.

Antigens, CD↗
PubMed1994

Blood glucose distribution and prevalence of diabetes in Hanoi (Vietnam).

Few epidemiologic surveys have been performed to assess the prevalence of diabetes in representative samples, and few data are available on the epidemiologic features of diabetes in Southeast Asia. We report the results of a 1990 study performed in the Hanoi area (Vietnam) on 4,912 subjects (95.0% of the eligible population), aged 15 years or over, selected by a stratified random cluster procedure using the 1989 census list. A two-step design was used: 1) screening for diabetes by measuring capillary blood glucose (CBG) before dinner with a Glucometer II device; and 2) for subjects with a CBG measurement of > or = 105 mg/dl, a diagnostic test on the following morning, using a 75-g oral glucose tolerance test and World Health Organization criteria (93.9% of the positive screenees took this test). CBG values before dinner were unimodally distributed and skewed to the right, increasing with age in both sexes. Women had a significantly higher level of age-adjusted CBG than did men before dinner (p < 0.0001) as well as when fasting (p < 0.0001) and 2 hours after the oral glucose tolerance test (p = 0.013). The prevalence of diabetes was 1.2% (95% confidence interval (CI) 0.9-1.5) and of impaired glucose tolerance, 1.6% (95% CI 1.3-2.0). Women had a significantly higher age-adjusted prevalence of diabetes than did men (relative risk = 2.3; 95% CI 1.3-4.1). Of the 63 diabetic subjects, nine (14.3%) had been diagnosed before the study, only one was obviously insulin dependent, and only one was obese with a body mass index of > or = 27 kg/m2. The subjects living in the urban areas had higher levels of fasting and 2-hour CBG and a higher diabetes prevalence than did the rural inhabitants (relative risk = 1.3; 95% CI 1.04-3.23). Diabetes appears to be a rare disease in the Hanoi area (1.4% for subjects aged 30-64 years, after age standardization using the Segi distribution), affecting women two times as often as men. Typical insulin-dependent (type I) or obese non-insulin-dependent (type II) diabetes mellitus patients are uncommon.

Adolescent↗