Search PubMed⌕ Search

Biomedical subjects

C Cooper

Publications and source records attributed to C Cooper.

At least 451 records · Page 25Linked to original sources
PubMed1991

Appendicular skeletal status and hip fracture in the elderly: 14-year prospective data.

Fourteen-year follow-up of 535 elderly people included in a British survey in 1973 revealed 23 incident hip fractures. The relationship between appendicular bone mass, assessed in the initial survey by metacarpal morphometry, and fracture risk was analyzed. There was an increased risk of hip fracture with declining metacarpal cortical index at baseline. The risk increase, however, was not statistically significant. It remained similar after adjustment was made for the reported prevalence of falls. These prospective data suggest that osteoporosis may contribute less to the risk of hip fracture in the very elderly than in younger individuals.

Age Factors↗
PubMed1991

Fractures of the hip and distal forearm in West Africa and the United Kingdom.

Comparison of age- and sex-specific incidence rates of fractures of the proximal femur and the distal forearm showed significantly lower rates in Ibadan than in two urban centres in England, with risk ratio of up to 20. In the Ibadan data no evidence of higher rates in women or of a prominent age-associated increase in rates was observed.

Aged↗
PubMed1991

Use of chemotaxonomy as an aid to differentiate among Capnocytophaga species, CDC group DF-3, and aerotolerant strains of Leptotrichia buccalis.

Four strains of fastidious gram-negative rods, thought to be Capnocytophaga species (formerly CDC group DF-1 or Bacteroides ochraceus) or CDC group DF-3 on the basis of conventional phenotypic criteria, were also analyzed for cellular fatty acid (CFA) composition. It was found that the CFA compositions of these strains were qualitatively incorrect for those taxa. Subsequently, it was determined that all four bacteria were in fact aerotolerant strains of Leptotrichia buccalis, based on biochemical reactions, CFA composition, and lactic acid as the major end product of glucose fermentation. It is recommended that, in addition to conventional cultural and biochemical criteria, all strains of Capnocytophaga or CDC group DF-3 should also be tested for metabolic end products of fermentation and CFA composition as essential adjuncts for identification.

Bacteroidaceae↗
PubMed1991

Osteoarthritis of the hip and acetabular dysplasia.

The relation between acetabular dysplasia and osteoarthritis of the hip was examined in a series of 1516 pelvic radiographs taken for non-skeletal indications. Osteoarthritis was assessed by measuring joint space, and dysplasia by the centre-edge angle and acetabular depth. In contrast with previous studies of patients with symptomatic osteoarthritis of the hip, no evidence that dysplasia predisposes to osteoarthritis was found. Possible reasons for the discrepancy are discussed. It was concluded that although acetabular dysplasia may lead to osteoarthritis of the hip in some subjects, it is unlikely to be an important cause of the disease in men.

Acetabulum↗
PubMed1991

Osteoarthritis of the hip and osteoporosis of the proximal femur.

A negative association has been reported between osteoarthritis and osteoporosis. There are, however, few population based data to support this association. In this study the bone density in the upper femur was compared with the presence and severity of hip osteoarthritis in 314 subjects undergoing radiography for non-skeletal indications. There was a statistically significant negative association between the two disorders. This relation may reflect differences in the cause of these two major musculoskeletal conditions.

Adult↗
PubMed1991

An investigation of ring and dicentric chromosomes found in three Turner's syndrome patients using DNA analysis and in situ hybridisation with X and Y chromosome specific probes.

We have studied three patients with features of Turner's syndrome, two with a 45,X/46,X,r(?) and the third with a 45,X/46,X,dic?(Y) karyotype. Because Turner's syndrome patients with a mosaic karyotype containing a Y chromosome are known to have a high risk of developing gonadal tumours, we used DNA analysis and in situ hybridisation with X and Y specific probes to identify the chromosomal origin of the rings and dicentric chromosomes in the three index patients. Both ring chromosomes were shown to be of X origin, while the dicentric was composed of Y chromosome material. We discuss the importance of using a combination of molecular and cytogenetic analyses in such cases.

Adolescent↗
PubMed1991

Gallbladder varices: imaging findings in patients with portal hypertension.

A retrospective review of the medical and imaging records of 50 patients with portal hypertension examined in the authors' department during a 2-year period identified six patients with gallbladder wall varices. Imaging studies performed in these patients included computed tomography (CT) (four patients), duplex and color Doppler flow (five patients), and magnetic resonance (MR) (four patients). Five of six patients with gallbladder varices had portal vein thrombosis. Anechoic areas within the gallbladder wall detected with ultrasonography could be distinguished from intramural edema by using duplex or color Doppler flow imaging in all five patients in whom it was used. Contrast material enhancement of these varices was detected with CT in three patients, two of whom also had adjacent mesenteric collaterals. Gradient-echo MR imaging (fast imaging in steady precession/fast low-angle shot) showed flow-related enhancement within the gallbladder wall in two patients. The presence of gallbladder wall varices may imply the presence of portal vein thrombosis. Since these varices can be a source of major blood loss, surgeons must be made aware of them when operating on patients with portal hypertension.

Adult↗
PubMed1991

Requirement for cell-to-cell contact for the immunosuppressive activity of human alveolar macrophages.

The ability of alveolar macrophages (AM) obtained by bronchoalveolar lavage of healthy volunteers to suppress T lymphocyte responses to the mitogen phytohemagglutinin (PHA) in vitro was investigated. AM but not monocytes (MN) inhibited responses of peripheral blood mononuclear cells (PBMC) to PHA as measured by incorporation of [3H]thymidine [( 3H]TdR) and interleukin-2 (IL-2) expression. Supernatants of AM generated for various periods and with various concentrations of cells did not, however, inhibit PBMC responses to PHA. To examine the role of cell contact in the inhibitory activity of AM, AM or MN were added to PBMC in 6-well plates either directly (in co-culture) or separated by a 0.45-micron filter. MN did not inhibit PBMC blastogenic responses under either condition. AM at a 1:2 ratio with PBMC inhibited blastogenesis by 75 +/- 11% (mean +/- SD, n = 3, P less than 0.01) when cultured directly with PBMC but had no inhibitory effect on blastogenesis when physically separated from target PBMC. AM in co-culture with PBMC also inhibited PHA-stimulated IL-2 production by 70% but did not inhibit IL-2 production when AM were separated from PBMC in dual chambers. To assess the role of the cell surface in the inhibitory activity of AM, AM and MN were fixed with 2% paraformaldehyde. Neither fixed nor unfixed MN inhibited PBMC blastogenic responses, but both fixed and unfixed AM inhibited responses similarly (77 to 95%).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

MR imaging of the portal venous system: value of gradient-echo imaging as an adjunct to spin-echo imaging.

We evaluated the use of gradient-echo (GRE) as an adjunct to spin-echo (SE) MR imaging of the portal venous system. GRE imaging was performed in 31 subjects, 15 normal volunteers and 16 patients with documented portal venous disease (15 cases) or suspected disease (one case). Eight of 16 patients had venous thrombosis, five had focal thrombus, and three had complete occlusion. Six patients had extrinsic venous compression by tumor. Of the two other patients, one had an arteriovenous fistula and the other a falsely positive angiogram, suggesting portal vein occlusion. In normal subjects, GRE scans had excellent visualization of the portal venous system with high intravascular signal compared with surrounding tissues. Nine (60%) of 15 normal subjects and three patients had an artifact consisting of a curvilinear area of decreased signal that could mimic clot. In three of five patients with focal thrombus, clot was identified on GRE but not on SE images. In all three patients with occlusion, SE and GRE images demonstrated similar findings. In five of the six patients with extrinsic venous compression by tumor, SE and GRE studies showed similar findings. Of the two patients, an arteriovenous fistula was seen on GRE MR in one, and in the other, patency of the left portal vein was seen on SE and GRE images after angiography had suggested portal vein occlusion. Collateral vessels were seen in nine of 16 patients. In five of nine cases, GRE MR demonstrated more extensive collaterals than did SE MR. In summary, GRE MR provides a useful adjunct to standard SE MR imaging. Benefits include high contrast between vascular structures and surrounding tissues, reduced motion artifact, and rapid scanning within a breath-hold.

Adolescent↗
PubMed1991

Expression of the parathyroid hormone-related peptide gene in rat tissues.

We have demonstrated that parathyroid hormone-related peptide (PTHrP) mRNA is expressed ubiquitously in normal tissues of the rat, including organs previously considered to be transcriptionally silent. We reverse transcribed PTHrP and PTH mRNA and amplified the resultant cDNA using the polymerase chain reaction. The level of transcriptional activity of PTHrP was highly variable in different tissues, suggesting tissue-specific regulation. Significant PTHrP gene activity in the nonlactating mammary gland of the pregnant rat suggests that PTHrP may be involved in mammary differentiation. PTHrP gene expression was detected throughout the gastrointestinal tract and in cardiovascular tissues, suggesting that it might act as an autocrine and/or paracrine regulatory factor and may be the natural ligand for the receptors discovered originally in these tissues using PTH analogs. In contrast, PTH gene activity is restricted to the parathyroids, under physiologic conditions.

Animals↗
PubMed1990

Immunologic responsiveness in American cutaneous leishmaniasis lesions.

American cutaneous leishmaniasis is a disease of skin and mucous membranes in which T lymphocytes reactive to Leishmania (Viannia) braziliensis are thought to contribute to protective immunity. To characterize the nature of the T cell inflammatory infiltrate in American cutaneous leishmaniasis lesions, immunohistochemistry with mAb that define T cell subpopulations and in situ hybridization to detect mRNA coding for IFN-gamma were performed. In both localized cutaneous (LCL) and mucocutaneous (MCL) lesions, we observed a predominance of T memory (CD4+CD45RO+) as compared to T naive cells (CD+CD45RA+). The percentages of cells containing IFN-gamma mRNA were equivalent in both LCL and MCL lesions. T cells were extracted from LCL and MCL lesions and analysis indicated that T cells from both lesions had been stimulated by L. (V.) braziliensis in vivo and gave equivalent proliferative responses in vitro. The present data suggest that T memory cells, which are likely to elaborate IFN-gamma, are components of DTH response to L. (V.) braziliensis and participate in the pathogenesis of both LCL and MCL lesions.

Animals↗
PubMed1990

Analysis of the transgenome of MET transfectant cell lines reveals that MET activation is accompanied by an interstitial insertion.

The MET oncogene, present in the MNNG-HOS chemically transformed human cell line, is activated by a gene fusion involving sequences from chromosome 1 and chromosome 7. Activated MET can act as a dominant selectable marker for chromosome-mediated gene transfer, and several transfectant cell lines have been established using this technique. Analysis of the transgenomes within these cell lines indicates that MET activation is not simply due to a chromosome translocation, but may involve an interstitial insertion of DNA from chromosome 1, into chromosome 7, probably associated with other rearrangements. Pulse field gel analysis of two transfectants indicates that, despite the presence of complex rearrangements close to MET, chromosome 7 sequences are grossly intact over a 1-Mb region thought to contain the gene defective in cystic fibrosis.

Animals↗