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Biomedical subjects

D Curtis

Publications and source records attributed to D Curtis.

At least 181 records · Page 10Linked to original sources
PubMed1991

No evidence for a susceptibility locus predisposing to manic depression in the region of the dopamine (D2) receptor gene.

Recent reports of cytogenetic abnormalities linked to psychiatric illness and the localisations of the genes for the dopamine (D2) receptor and tyrosinase on the long arm of chromosome 11 have suggested that susceptibility loci for schizophrenia and manic depression might be situated in this region. We could find no evidence for linkage in five Icelandic pedigrees between manic depression and markers in this region, and we have excluded candidate genes coding for the D2 receptor and tyrosinase. We conclude that mutations at loci in this region are not a common cause of manic depression in the population studied.

Adult↗
PubMed1991

Decreased hippocampal expression of a glutamate receptor gene in schizophrenia.

'A striking and specific loss of the messenger RNA that encodes a non-N-methyl D-aspartate (non-NMDA) glutamate receptor was found in hippocampal tissue obtained at necropsy from 6 patients with schizophrenia, when compared to specimens from 8 controls without neurological or psychiatric signs or symptoms. These findings support suggestions of aberrant glutamatergic function in schizophrenia. Evidence that gene expression may be abnormal in schizophrenia, with decreased production of an excitatory neurotransmitter receptor, may have therapeutic as well as pathogenetic implications.'

Gene Expression Regulation↗
PubMed1991

Linkage disequilibrium between two highly polymorphic microsatellites.

The PCR was used to amplify genomic DNA from two microsatellite (dC-dA)n.(dG-dT)n sequences found to be present in the same chromosome 5 genomic clone. Analysis of the haplotype frequencies of these two interspersed repeat sequences in individuals showed strong allelic association or linkage disequilibrium. Six alleles were found for p599 (CA)n with a PIC value of 0.71 and 8 alleles were seen for lambda 599 (CA)n with a PIC value of 0.74. The two microsatellites are separated by approximately 7 kb. Analysis of the length variations for the two microsatellites showed that they were positively correlated, a finding that has no obvious explanation. The strong linkage disequilibrium found demonstrates stability during evolution for these novel markers. Therefore they should be powerful new tools for studying genetic drift and admixture of populations. Furthermore, disequilibrium data from microsatellites can be used in the fine mapping and cloning of disease genes.

Alleles↗
PubMed1991

Complexity preference in substance abusers and controls: relationships to diagnosis and personality variables.

To assess the relationship between complexity preference as measured by the Barron-Welsh Revised Art Scale and models of arousal and personality, 36 male substance abusers and 24 community controls were given this tool as well as a battery of personality tests. Some support was found for the notion that emotionality, as measured by the Test of Emotional Styles, was associated with preference for complexity. Relevant neurobiological models of affective expression and hemispheric asymmetry are discussed in light of these findings.

Adult↗
PubMed1990

Synergistic effects of azathioprine and ultraviolet light detected by sister chromatid exchange analysis.

The immunosuppressant azathioprine and longwave ultraviolet (UV) light have been postulated to have a synergistic effect on DNA resulting in carcinogenic change. This study investigated the in vitro effect of UV light on renal transplant recipients (RTRs) immunosuppressed with azathioprine and prednisolone to prevent rejection and patients on azathioprine for skin conditions and normal controls on no drug therapy. The results show clearly that there is an increase in sister chromatid exchanges (SCEs) in both patient groups in response to UV light with the greatest increase shown by the RTRs. Both patient groups without exposure to UV also showed a significant increase, as compared with normal controls, with the RTRs again showing the highest level. Both patient groups also showed disruption of the cell cycle in response to UV light as measured by the proliferative rate index (PRI) but the controls did not. These findings support the hypothesis of a synergistic effect between azathioprine and UV light and correlate well with the clinical pattern of carcinogenesis observed in these patients, with RTRs having a well-documented increased risk of neoplasia, particularly skin carcinomas in light-exposed areas.

Adult↗
PubMed1990

Endodontic considerations when fabricating overdentures.

Successful use of an overdentures prosthesis depends on the successful completion and maintenance of endodontically-treated teeth. The process of completion and maintenance of teeth so treated in elderly individuals is difficult and less predictable. The purpose of this paper is to discuss treatment considerations to enhance success when treating elderly candidates for endodontic overdenture abutment retention.

Aged↗
PubMed1989

Carrier detection and prenatal diagnosis in Norrie disease.

We report the use of DNA probes to determine carrier status in three young women from a large kindred with Norrie disease. One of the women requested prenatal diagnosis during pregnancy. In this pedigree, Norrie disease was not characterized by a deletion at DXS7.

Blindness↗
PubMed1989

Understanding Romanowsky staining. 2. The staining mechanism of suspension-fixed cells, including influences of specimen morphology on the Romanowsky-Giemsa effect.

Romanowsky staining of suspension-fixed lymphocytes and fibroblasts, deposited as monolayers on slides, involves an initial basic dyeing process followed by formation of a hydrophobic Azur B/Eosin Y complex at the more permeable and so faster staining cellular sites. This mechanism is shared with blood and marrow smears. However certain morphological features peculiar to suspension-fixed, cell culture-derived preparations also influence the staining pattern via rate control: namely the irregular and bulky profiles of fibroblasts, compared to the smoother and thinner lymphocytes; and the occasional superficial occlusion of cells by culture medium.

Azure Stains↗
PubMed1989

Molecular analysis of recombination events in Drosophila.

The locations of crossover junctions and gene conversion tracts, isolated in the rosy gene of Drosophila melanogaster, were determined using DNA sequencing and denaturing gradient gel electrophoresis. Frequent DNA sequence polymorphisms between the parental genes served as unselected genetic markers. All conversion tracts were continuous, and half of the reciprocal crossover events had conversion tracts at the crossover junction. These experiments have also identified the sequence polymorphisms responsible for altered gene expression in two naturally occurring rosy variants.

Animals↗
PubMed1989

Recent and future molecular genetic research into schizophrenia.

The difficulties anticipated in the application of molecular genetics to schizophrenia research have not prevented the first successful localization of a susceptibility gene for a subtype of schizophrenia. It is argued that this approach is the most useful of the possible molecular genetic strategies because it leads both to enhanced clinical genetic investigation and to further recombinant DNA research to clone and sequence schizophrenia susceptibility mutations. Future recombinant DNA research can now use long-range mapping and cloning techniques such as the chromosome walking/jumping approach and the strategy of cloning brain-specific cDNAs from brain mRNA. The identification of carriers for high-risk studies and the genetic validation of diagnosis appear to be the most promising clinical developments. Prenatal counseling will only become widely feasible when much more is known about the extent of heterogeneity of linkage in schizophrenia.

Chromosomes, Human, Pair 5↗