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Biomedical subjects

A Curtis

Publications and source records attributed to A Curtis.

At least 19 recordsLinked to original sources
PubMed1992

The effects of staurosporine and okadaic acid on baby hamster kidney fibroblast cell adhesion.

The effects of staurosporine, a potent protein kinase C inhibitor, and okadaic acid, a non-TPA tumour promoter, on the adhesion of BHK fibroblast were investigated. Staurosporine at 2.5 and 5 microM was found to stimulate a gradual increase in BHK cell adhesion as well as spreading in 3% serum-containing medium. An increase of approximately 27% over the control value was found at 5 microM concentration in 20 minutes. No such effect was seen in serum-free conditions. Staurosporine at 5 microM, enhanced BHK cell-cell adhesion in 3% serum and in serum-free conditions. Okadaic acid, a phosphatase inhibitor, at concentrations between 0.25 and 1 microgram/ml, was found to inhibit BHK cell-substratum adhesion and spreading. The inhibitory effect was time and concentration dependent. These findings suggest that protein kinase C might be involved in the mechanism(s) controlling BHK cell attachment.

Alkaloids↗
PubMed1992

The gene for Aarskog syndrome is located between DXS255 and DXS566 (Xp11.2-Xq13).

Aarskog syndrome has been mapped to Xq13 on the basis of a patient carrying an Xq13:8p21.2 translocation. We have identified a new microsatellite marker in a clone mapping to this region (HX60;DXS566). Using primers flanking this microsatellite along with primers detecting a microsatellite at PGK1P1 and DXS255, and DXS72, we have performed a multipoint analysis in a large kindred with Aarskog syndrome. Our results suggest that the Aarskog locus lies proximal to Xq13. This is supported by the recent redefining of the breakpoint of the original translocation as between DXS14 (Xp11.21-p11.1) and DXS146 (Xp11.23-p11.22).

Abnormalities, Multiple↗
PubMed1992

Molecular genetics of inherited retinal degenerations.

There has recently been substantial progress in categorizing the vast range of human retinal degeneration phenotypes. A molecular approach has assigned chromosomal locations for approximately a dozen such diseases and has identified four of the genes involved.

Albinism, Ocular↗
PubMed1992

A submicroscopic translocation, t(4;10), responsible for recurrent Wolf-Hirschhorn syndrome identified by allele loss and fluorescent in situ hybridisation.

A 2 year old girl presented with developmental delay and subtle dysmorphic features suggestive of Wolf-Hirschhorn syndrome (WHS). High resolution chromosome analysis was normal in the child and both parents. Molecular analysis indicated that the child had not inherited a maternal allele of probes from 4p16, confirming the clinical diagnosis. Prenatal diagnosis in the next pregnancy showed that again the fetus had no maternal allele for probes mapping to 4p16. Fluorescent in situ hybridisation in the mother showed a submicroscopic translocation, t(4;10). A normal karyotype in a child with clinical features of WHS is an indication for further investigation.

Abnormalities, Multiple↗
PubMed1991

Identification of a mutation in the promoter region of the dystrophin gene in a patient with atypical Becker muscular dystrophy.

We have identified 7 patients with Becker muscular dystrophy (BMD) in whom analysis of dystrophin by immunoblotting shows a full-sized molecule produced at reduced abundance compared with controls. They have no detectable deletion in their dystrophin cDNA. One patient presented atypically with unusually severe cramps as his only symptom for 25 years. These patients were investigated using the polymerase chain reaction (PCR) with 3 sets of primers within the promoter region of the dystrophin gene, followed by dot blot and restriction analysis. In the patient with the atypical history, one of the expected fragments on PCR failed to amplify. A large deletion was excluded by the finding of normally sized fragments on amplification with the other primer sets. The mutation was localised to the 3' end of the forward primer binding site by dot blot and restriction analysis. This result supports the hypothesis that, in patients with a full-sized dystrophin molecule produced at reduced abundance, the phenotype may result from a mutation in the promoter region of the dystrophin gene. The atypical history of the patient in whom this was detected adds to the variety of phenotypes now known to exist as BMD.

Adolescent↗
PubMed1991

Association of less common cystic fibrosis mutations with a mild phenotype.

A majority of cystic fibrosis (CF) genes (70 to 75%) share a single mutation, but the remaining 25 to 30% of defects are accounted for by more than 20 different mutations. One of the less frequent mutations, G551D, has been identified in the CF genes of two sibs and one unrelated adult patient. The adult patient also has a second rare mutation, delta I507. All three subjects exhibit a less severe phenotype than that normally associated with CF. This supports a hypothesis that the common mutation (delta F508) is responsible for the severe form of the disorder, and the minority of patients with a milder form tend to have mutations at other sites in the CF gene.

Adolescent↗
PubMed1991

Linkage disequilibrium and recombination make a telomeric site for the Huntington's disease gene unlikely.

In a Scottish family in which Huntington's disease (HD) was segregating, recombination was observed between the D4S115/S111 and D4S43/S95 loci, with the HD gene associated with the more proximal D4S43/S95 locus. Analysis of linkage disequilibrium in Scottish families showed significant non-random association between the HD gene and alleles at the D4S95 and D4S98 loci. This adds to previous evidence that the HD locus is not sited at the telomere of chromosome 4.

Alleles↗
PubMed1990

Detection and quantitation of HLA class II molecules on keratinocytes by quantitative immunofluorescence.

The paper describes measurements of HLA-DR antigen expression on normal human keratinocytes in culture using anti-HLA-DR antibodies and fluorescent Protein A or fluorescent second antibody methods and a low-light level video camera and image analysis program to quantitate the fluorescence output. The measurements are ultimately quantitated in terms of molecules of Ia antigen reacting material per cell. The method has a sensitivity at a S/N ratio of 10:1 of 180 molecules/micron2. The results show that normal keratinocytes do indeed express class II antigens on their surfaces at levels well above background. We confirm that treatment of the cells with gamma-interferon produces enhanced expression of DR antigens within 4 days. The method of quantitation is applicable to fluorescence and other low light level images.

Calibration↗
PubMed1990

The haplotype distribution of the delta F508 mutation in cystic fibrosis families in Scotland.

The gene defective in cystic fibrosis (CF) has recently been isolated and the major mutation identified. The haplotype distribution of this mutation (delta F508) has been determined for 215 CF chromosomes in the Scottish population. delta F508 represents 73% of all CF mutations in this group. There remains considerable linkage disequilibrium between XV2c and KM19 and other mutations in the CF gene.

Chromosome Deletion↗
PubMed1990

Hyperbaric oxygen therapy for necrotizing fasciitis reduces mortality and the need for debridements.

Twenty-nine patients with necrotizing fasciitis were treated from 1980 to 1988. This study evaluates how the addition of hyperbaric oxygen (HBO) therapy to surgical treatment has affected mortality and the number of debridements required to achieve wound control in these patients. Two groups of patients were viewed: group 1 (n = 12) received surgical debridement and antibiotics only; group 2 (n = 17) received HBO (90 minutes at 2.5 atm, average 7.4 treatments) in addition to surgery and antibiotics. Both groups were similar in age, race, sex, wound bacteriology, and antimicrobial therapy. Body surface area affected was similar, however, perineal involvement was more common in group 2 (53%) than in group 1 (12%). The admitting conditions of patients in group 1 (non-HBO) were diabetic, 33%; white blood cell count more than 12,000, 50%; and shock, 8%. The admitting conditions of patients in group 2 (HBO) were diabetic, 47%; white blood cell count more than 12,000, 59%; and shock, 29%. Although group 2 patients receiving HBO were more seriously ill on admission, mortality was significantly lower (23%) compared to group 1 (66%) (p less than 0.02). In addition, only 1.2 debridements per group 2 patient were required to achieve wound control versus 3.3 debridements per group 1 patient (p less than 0.03). The addition of HBO therapy to the surgical and antimicrobial treatment of necrotizing fasciitis significantly reduced mortality and wound morbidity (number of debridements) in this study, especially among nonclostridial infections. We conclude that HBO should be used routinely in the treatment of necrotizing fasciitis.

Adolescent↗
PubMed1989

Predictive testing for Huntington's disease with linked DNA markers.

Availability of new DNA markers, more tightly linked to the Huntington's disease (HD) locus than the original G8 (D4S10) probes, has improved predictive accuracy for both presymptomatic and prenatal exclusion testing. 50 predictive tests were carried out on high-risk individuals. 6 of these were on first-trimester chorionic villus biopsy specimens; in 2 cases the HD gene was not transmitted to the fetus while in 4 cases no exclusion could be made. The remaining 44 tests were on adults with either 25 or 50% risk of manifesting the disease; 19 had a greatly increased risk and 25 a substantially decreased risk of HD. Family structures in Scotland are suitable for testing about 75% of potentially affected individuals, and the new generation of DNA markers makes virtually all families fully informative.

Adult↗