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Biomedical subjects

C Collins

Publications and source records attributed to C Collins.

At least 55 records · Page 3Linked to original sources
PubMed1997

Tumors around implants.

In 1989, A. G. Apley recommended cautious surveillance of malignant tumors that developed in association with orthopaedic implants. This retrospective review of the Bristol Bone Tumour Register between 1980 and 1992 reports on 240 malignant soft tissue sarcomas. Eighteen developed in the thigh region of patients more than 50 years old, and 4 of these developed in the soft tissues around a hip arthroplasty.

Aged↗
PubMed1997

Physical mapping of the 5 Mb D9S196-D9S180 interval harboring the basal cell nevus syndrome gene and localization of six genes in this region.

The basal cell nevus syndrome (Gorlin syndrome) is characterized by multiple basal cell carcinomas and diverse developmental defects. The gene responsible for this syndrome has been mapped previously to a 2 cM interval between D9S196 and D9S 180 at 9q22.3, and very recently mutations of a candidate gene in this region--the human homolog of the Drosophila patched gene have been identified. We report here on physical mapping studies integrating a contig of yeast artificial chromosomes and bacterial artificial chromosomes with a long-range map spanning approximately 5 Mb between the recombination-determined flanking markers. Six genes have been mapped to this interval.

17-Hydroxysteroid Dehydrogenases↗
PubMed1997

Emotional distress and morbidity in dementia carers: a matched comparison of husbands and wives.

OBJECTIVE: This study aimed to: (i) replicate previous findings that women experience more strain and distress than men when caring for dementing spouses; (ii) explore what factors underlie this sex difference. DESIGN: Two closely matched subsamples of spouse carers, husbands and wives respectively, were selected and the two groups compared. SETTING: An urban psychogeriatric service in the UK. SUBJECTS: 48 spouses of referred dementia cases. MEASURES: Mental health was rated by the General Health Questionnaire, the Strain Scale and the Life Satisfaction Index. Various factors related to caregiving were assessed by the Problem Checklist, and a specially devised instrument to record caregiving task involvement, formal/informal support, objective burden, satisfaction with supports and attitudes to the relationship and to caregiving. RESULTS: The wives' levels of strain and morale were significantly worse than husbands'. There were qualitative differences between husbands and wives in terms of caregiving tasks undertaken. Wives tolerated dementia sufferers depending on them less well. Wives were also more likely to wish to leave caregiving to someone else and cited more reasons for giving up. Subjects of both sexes displayed a strong tendency to view women as generally better suited to the caregiving role, and wives felt a greater obligation to care. CONCLUSIONS: It is concluded that such attitudinal or social factors are the chief determinants of wives' higher levels of strain and distress.

Aged↗
PubMed1996

Cloning, mapping, and in vivo localization of a human member of the PKCI-1 protein family (PRKCNH1).

We report here the complete cDNA sequence, genomic mapping, and immunolocalization of the first human member of the protein kinase C inhibitor (PKCI-1) gene family. The predicted human protein (hPKCI-1) is 96% identical to bovine and 53% identical to maize members, indicating the great evolutionary conservation of this protein family. The hPKCI-1 gene (HGMV-approved symbol PRKCNH1) maps to human chromosome 5q31.2 by fluorescence in situ hybridization. Indirect immunofluorescence shows that hPKCI-1 localizes to cytoskeletal structures in the cytoplasm of a human fibroblast cell line and is largely excluded from the nucleus. The cytoplasmic localization of hPKCI-1 is consistent with a postulated role in mediating a membrane-derived signal in response to ionizing radiation.

Amino Acid Sequence↗
PubMed1996

Independent amplification and frequent co-amplification of three nonsyntenic regions on the long arm of chromosome 20 in human breast cancer.

DNA amplification at 20q13.2 is common in breast cancer, correlates with poor prognosis, and may reflect location of an important oncogene. Recently, other regions along 20q were also found to undergo amplification. Here, amplification levels and patterns of co-amplification were analyzed by interphase fluorescence in situ hybridization at 14 loci along 20q in 146 uncultured breast carcinomas and 14 cell lines. Three regions were independently amplified in uncultured tumors: RMC20C001 region at 20q13.2 (highly amplified in 9.6% of the cases), PTPN1 region 3 Mb proximal (6.2%), and AIB3 region at 20q11 (6.2%). Co-amplifications involving two or three of these regions were seen in 11 of the 19 highly amplified tumors. The results suggest that three distinct nonsyntenic regions along 20q may be important and that complex chromosomal rearrangements underlie their frequent co-amplification in breast cancer.

Breast Neoplasms↗
PubMed1996

RAG1, RAG2 and pre-T cell receptor alpha chain expression by adult human hepatic T cells: evidence for extrathymic T cell maturation.

Flow cytometric analysis of cell suspensions obtained from normal adult liver tissue at the time of transplantation revealed significant populations of T lymphocytes. These were examined for molecular evidence of local T cell maturation using reverse transcription-polymerase chain reaction to detect expression of recombination activation gene 1 (RAG1), RAG2 and pre-T cell receptor alpha chain (pTalpha), which occurs only in early thymocyte development. Four specimens of whole liver were positive for RAG1 and RAG2 expression, whereas peripheral blood mononuclear cells from the same individuals were negative. To localize RAG expression, immature (CD2+CD7+) and mature (CD45R0+) T cell subpopulations were isolated by magnetic separation from hepatic and peripheral blood mononuclear cell preparations. We detected the expression of RAG1, RAG2 and pre-TCRalpha in five specimens of hepatic CD2+CD7+ but not in CD45RO+ hepatic lymphocytes. Four out of six specimens of CD2+CD7+ cells from the peripheral blood were negative for RAG1 and RAG2 while all six specimens were positive for pTalpha expression. These results suggest that pre-T cells are trafficking from the bone marrow or the thymus to other tissues to continue differentiation and selection in the context of an appropriate cellular and molecular environment. The presence of immature populations of T cells in the adult liver and high levels of RAG expression suggests that the adult liver provides such an environment for extrathymic T cell maturation. These findings may have important implications for tolerance induction after liver transplantation and offer help in understanding the etiology of autoimmune liver disease.

Adult↗
PubMed1996

Amplifications of oncogene erbB-2 and chromosome 20q in breast cancer determined by differentially competitive polymerase chain reaction.

A new method of measuring gene copy number in small samples of DNA was used to measure amplification of the erbB-2 gene and of chromosome 20q in breast cancer. This method, termed 'differentially competitive polymerase chain reaction' (DC-PCR) combines the advantages of two other techniques for measuring amplification by PCR, namely differential PCR and competitive PCR. The DC-PCR methodology was evaluated for sensitivity and specificity by comparing amplification of erbB-2 measured by DC-PCR with that obtained by fluorescence in situ hybridization (FISH) for 42 cases or Southern blotting and/or slot blot analysis for 34 cases. There was over 90 percent concordance with both FISH and Southern blotting and/or slot blot analysis. DC-PCR was used to further characterize the newly described amplicon at chromosome 20q. By analyzing DNA from 10 breast cancer cell lines at 7 different loci, we identified a potential common region of amplification of approximately 5 centimorgans at chromosome 20q13 bordered by loci D20S52 and RMC20C100-S1. One hundred and seventeen cases of primary breast cancer were evaluated for amplification at these two loci. Amplification at one or more loci, defined as > 1.5 fold higher copy number than that of normal DNA, was found in 25 cases (21%). Sixteen cases were amplified at only one of the two probes (12 cases for RMC20C001-S1 and 4 cases for D20S52), suggesting that the target gene lies between the two markers or that there are two independent target genes within a small chromosome region.

Blotting, Southern↗
PubMed1996

Phase II study of high-dose cisplatin, etoposide, and cyclophosphamide for refractory ovarian cancer.

OBJECTIVES: A phase II trial of high-dose cyclophosphamide, etoposide, and cisplatin was done. STUDY DESIGN: Forty-eight patients with progressive or persistent disease and previous cisplatin-based chemotherapy and no paclitaxel therapy were entered for treatment on the basis of two cycles of cyclophosphamide (4500 mg/m2), etoposide (750 mg/m2), and cisplatin (120 mg/m2). RESULT: Seventy-four cycles were delivered. Six patients died during treatment (12.5%). Of 28 with measurable disease, there was a 25% response rate and 32% had stable disease. Median time to recurrence and survival were significantly different for minimal versus bulky disease (p = 0.0089, p = 0.0008, log rank) and for platinum-sensitive versus platinum-resistant disease (p = 0.18, p = 0.0012, log-rank). The number of prior regimens was not correlated with time to progression or survival. CONCLUSION: This study shows little advantage for high-dose protocols except for patients with a response to platinating agents and minimal residual disease.

Adult↗
PubMed1996

Genotype of the cystic fibrosis population of the Hunter Region of New South Wales.

OBJECTIVE: To determine the genotype of patients attending the cystic fibrosis clinic at John Hunter Hospital, Newcastle, Australia. METHODOLOGY: Seventy-five of the 76 patients attending the clinic over a 6 month period had blood collected for genetic analysis of 17 of the cystic fibrosis (CF) gene mutations. RESULTS: Sixty-one per cent of the patients were homozygous for the delta F508 mutation and all except one child had at least one delta F508 mutation. DISCUSSION: Nearly 80% of the CF genes were the delta F508 mutation. This prevalence suggests that the obligatory false negative rate of a newborn screening programme for CF based on a combination of immunoreactive trypsin and the delta F508 gene may be as low as 4-5%.

Adolescent↗
PubMed1996

Clonal analysis of human recurrent superficial bladder cancer by immunohistochemistry of P53 and retinoblastoma proteins.

PURPOSE: To investigate the clonal origin of malignant cells in recurrent superficial bladder cancer. MATERIALS AND METHODS: We compared the protein expression of p53 and retinoblastoma (Rb) by immunohistochemistry using antibody P1801 and PMG3-245, respectively, in 13 patients at the time of primary superficial bladder cancer resection (6 Ta and 7 T1) and their 15 corresponding recurrences of disease. Mutations in p53 and Rb were inferred on the basis of immunoperoxidase staining. RESULTS: At the time of initial tumor resection, a p53 mutation was observed in 5 patients (39%) and an Rb mutation was observed in 3 (23%). The p53/Rb mutation status of recurrent bladder cancers completely matched their corresponding primary bladder cancer. CONCLUSIONS: The chance that recurrent bladder cancer originated from independent clones in this study was extremely small (p < 10(-6)). This result strongly supports the monoclonal origin of recurrent superficial bladder cancer.

Carcinoma, Transitional Cell↗
PubMed1995

Mutagenesis analysis of the membrane-proximal ligand binding site of the TGF-beta receptor type III extracellular domain.

There are two TGF-beta binding subdomains in the extracellular domain of receptor type III (proximal and distal in relation to the transmembrane domain). Here we present an extension of our analysis of the proximal binding site of receptor type III. Due to the original deletion mutagenesis strategy, our proximal binding site contained 19 amino acids from the N-terminal part of the receptor. By deleting these, we demonstrated that they did not contribute to the binding ability of the proximal binding site. We also produced a soluble, secreted form of the proximal binding site and demonstrated that it was able to bind TGF-beta. Finally, we analyzed the role of the three asparagine residues (580, 591, 595) that are located in the region of the receptor that is necessary for expression of a functional proximal binding site, and found that mutation of these residues individually to alanine did not affect ligand binding.

Animals↗