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Biomedical subjects

R Taylor

Publications and source records attributed to R Taylor.

At least 235 records · Page 13Linked to original sources

Best estimate of the magnitude of mortality due to occupational exposure to hazardous substances.

OBJECTIVES: With a proportionate attributable risk approach, to estimate the magnitude of premature mortality induced by exposure to hazardous substances in the Australian workforce. METHODS: Estimates of the magnitude of mortality induced by exposure to hazardous substances in the Australian work-force were calculated by the proportionate attributable risk approach after careful consideration of options for methodological refinements. The main data sources used were unit mortality datasets (individual deidentified death records), and tabulations when these were unavailable. RESULTS: The estimated number of deaths that occurred in Australia each year from occupational exposure to hazardous substances was 2290; 78% of these were men. The rate of mortality attributable to occupational exposure to hazardous substances was three to four times greater in male workers than in female workers. Male (productive) person-years of life lost (PYLL) were generally eight times higher than female PYLL. Cancer was the prime cause of death, followed by renal, cardiovascular, neurological, and chronic respiratory disease. Acute toxic episodes accounted for a small proportion of mortality but yielded a much larger proportion of PYLL, reflecting the relatively young ages of those who experienced fatal effects. CONCLUSIONS: Although national estimates of the proportions of mortality attributable to occupational exposure to hazardous substances seemed to be validly derived, uncertainties remain associated with the lack of an empirical basis for derivation of proportionate risk fractions used in the calculations. The finding of an appreciable burden of mortality that is attributable to past occupational exposure to hazardous substances emphasises the necessity for occupational health and safety authorities to measure and reduce worksite exposures. There is also an incentive to encourage the construction of appropriately designed cohort studies across industries and occupational groupings so that, ultimately, risk estimates may be directly calculated and applied to total workforce data for the definitive estimation of the magnitude of harm induced by occupational exposure to hazardous substances.

Australia↗

Effects of community services on disability and symptoms. PRiSM Psychosis Study. 4.

BACKGROUND: Community care for people with psychosis can be provided via several different service models. The study compared two models: standard community treatment with high patient: staff ratios, and intensive community treatment in which there was more of an emphasis on community involvement and lower patient:staff ratios. METHOD: All people fulfilling diagnostic criteria for psychosis and living in two defined geographical areas in south London were identified. These people were provided with either an intensive or standard service depending on their address. Their social behaviour and symptoms were measured at the beginning of the study and after two years. RESULTS: There is little evidence of any effects of the two service models on levels of symptoms. However, the standard service did seem to be advantageous in reducing social disability for those with medium or low levels of disability. CONCLUSIONS: The effect of intensive community services was the opposite to that predicted. Despite improvements in outcomes (e.g. hospital admission), there were no advantages for this type of service in the measures of disability or symptoms. In fact, the standard service was effective in reducing disability, whereas in the intensive service there was no change.

Community Mental Health Services↗

A behavioral intervention for improving verbal behaviors of heroin addicts in a treatment clinic.

Positively reinforcing appropriate behaviors improved verbal behaviors of opioid-dependent patients in a buprenorphine treatment clinic. During B phases of an ABAB design, clients received stickers for engaging in appropriate verbal or nonverbal behaviors. Each sticker provided a chance of winning $25. No reinforcement was provided during the A phases. Appropriate verbal behaviors increased during reinforcement periods, and inappropriate verbal behaviors decreased.

Adult↗

Spiral maze performance in dementia.

58 patients with probable Alzheimer dementia and 58 with probable multi-infarct dementia were given spiral mazes of differing complexity and 20 other neuropsychological tests. When age and over-all neuropsychological functioning were taken into account, spiral maze performance was poorer for patients with multi-infarct dementia but there were no significant group differences related to task complexity or indices of performance strategy.

Adult↗

Effects of age of acquisition, word frequency, and familiarity on object recognition and naming in dementia.

116 patients with established dementia completed a short confrontation naming test. Naming latency correlated -.69 (Kendall tau, p < .001) with general frequency of the name of the object. Recognition failure correlated .53 with age of acquisition of the name and -.58 with familiarity of the object. These and other correlations are not in accord with recent findings from studies of normal people. More extensive studies of these relationships in dementia, where disorders of recognition and naming are common, would be informative.

Adult↗

Adhesion of tumoricidal eosinophils to MCA-38 colon adenocarcinoma cells involves protein tyrosine kinase activation and is diminished by elevated cyclic AMP in the effector cell.

Although eosinophils have been implicated in immune responses to certain types of tumors, the mechanisms of anti-tumor activity by eosinophils are poorly understood. We show here that mouse eosinophils kill allogeneic MCA-38 colon adenocarcinoma cells in the absence of specific anti-body. Eosinophil adhesion to MCA-38 monolayers occurred within 15 min and plateaued at 90 min. Although mouse eosinophils express alphaL (CD11a), alphaM (CD11b), and alpha4 (CD49d) integrin chains, blocking antibody studies revealed that these molecules are not involved in eosinophil binding to MCA-38 cells. Adhesion was also fibronectin-independent. Binding was inhibited when eosinophils, but not MCA-38 cells, were pretreated with methyl 2,5-dihydroxycinnamate (MDHC), a selective inhibitor of protein tyrosine kinases, or 8-Br-cAMP-Na, a cell-permeable cyclic AMP analogue. Adhesion was unaffected by calphostin C, a specific inhibitor of protein kinase C, and wortmannin, a selective inhibitor of phosphatidylinositol 3-kinases.

Adenocarcinoma↗

Cultural diversity in Florida nursing programs: a survey of deans and directors.

To determine how nursing programs in the state of Florida promote and integrate cultural diversity, a survey of deans and directors was conducted. Of 90 deans and directors surveyed, 46 (51%) responded. The ethnic composition of students and faculty in the respondents' programs was examined in comparison with that of the Florida population. Hispanics, Blacks, and Asians were found to be underrepresented in nursing faculty as compared with their proportion in the state population. The majority of deans and directors ranked the goal of promoting cultural diversity of moderate importance. The two most critical issues perceived by the respondents were the lack of cultural knowledge, sensitivity, and awareness, and the academic problems and educational deficits of minority students. In 50% of the programs surveyed, culture content was integrated throughout the curriculum. Other programs either integrated culture content in specific classes or offered a course in transcultural nursing. Although numerous approaches are currently being employed to recruit ethnically diverse faculty and students, the data suggest that more extensive and innovative efforts are needed to overcome existing barriers. As nursing faces the challenge of caring for a multicultural society in the 21st century, nursing leaders and organizations must collaborate to resolve the issues and problems revealed in this survey.

Cultural Diversity↗

Transferrin in normal and neoplastic endocervical tissues: distribution and receptor expression.

OBJECTIVE: Our recent studies showed that lactoferrin seems to be down-regulated in endocervical adenocarcinomas. We extended those studies to examine the expression of transferrin (Tf) and its receptor (TfR) in endocervical carcinogenesis and any relationship to the expression of lactoferrin, steroid receptors and the proliferative index. STUDY DESIGN: A retrospective study was performed using sections prepared from paraffin-embedded, formalin-fixed surgical specimens of normal endocervix, endocervical adenocarcinoma and cervical adenocarcinoma in situ. Standard immunohistochemical techniques were used to localize Tf and its receptor in the normal and malignant endocervix. In situ detection of mRNA for Tf and the TfR was also performed. The relative intensity of the immunoreaction was estimated using digital computer image analysis. Statistical significance was tested by Student's t test. RESULTS: No differences in the relative staining intensity for Tf and TfR proteins were noted between normal and neoplastic glands. However, quantitation revealed that a greater number of malignant glands stained positive for TfR than observed in the normal endocervix. Expression of Tf and TfR did not correlate with the expression of steroid receptors and lactoferrin or with the rate of proliferation. CONCLUSION: We have demonstrated the expression of Tf and its receptor by both normal and malignant endocervical glands. The increased number of malignant endocervical glands expressing TfR may indicate a special requirement for Tf and the iron that it carries. Our data provide evidence for the existence of a Tf, TfR autocrine or paracrine circuit involved in the regulation of normal and abnormal endocervical physiology.

Adenocarcinoma↗

Check your cultural competence.

Intrapersonal reactions such as ethnocentrism, prejudice, anxiety, stereotyping, and our comfort zone with the familiar can influence our interactions with culturally diverse people. Here, we explore these stumbling blocks, the dynamics behind these reactions, and strategies nurse managers can employ to enhance their cultural competence.

Clinical Competence↗

Involvement of XRCC1 and DNA ligase III gene products in DNA base excision repair.

DNA ligase III and the essential protein XRCC1 are present at greatly reduced levels in the xrcc1 mutant CHO cell line EM-C11. Cell-free extracts prepared from these cells were used to examine the role of the XRCC1 gene product in DNA base excision repair in vitro. EM-C11 cell extract was partially defective in ligation of base excision repair patches, in comparison to wild type CHO-9 extracts. Of the two branches of the base excision repair pathway, only the single nucleotide insertion pathway was affected; no ligation defect was observed in the proliferating cell nuclear antigen-dependent pathway. Full complementation of the ligation defect in EM-C11 extracts was achieved by addition to the repair reaction of recombinant human DNA ligase III but not by XRCC1. This is consistent with the notion that XRCC1 acts as an important stabilizing factor of DNA ligase III. These data demonstrate for the first time that xrcc1 mutant cells are partially defective in ligation of base excision repair patches and that the defect is specific to the polymerase beta-dependent single nucleotide insertion pathway.

Animals↗

Improvement in endothelial function by angiotensin converting enzyme inhibition in insulin-dependent diabetes mellitus.

We postulated that nitric oxide (NO)-mediated endothelial function would be improved by acute and short-term treatment with an angiotensin converting enzyme (ACE) inhibitor in patients with type I diabetes mellitus, in whom endothelial function is depressed. Nine type I diabetic patients and eight healthy subjects underwent forearm blood flow measurement using strain gauge plethysmography during intraarterial infusion of incremental doses of endothelium-dependent (acetylcholine [ACh]) and endothelium-independent (sodium nitroprusside [SNP]) vasodilators. Pretreatment ACh responses were depressed in diabetic patients relative to the normal subjects (P < 0.05). No difference between the groups was evident in response to SNP. Acute ACE inhibition (with intrabrachial enalaprilat) enhanced ACh responses in the diabetic patients (P < 0.005), with a further improvement evident after 1 mo of oral therapy with enalapril (P < 0.001) when ACh responses were normalized. ACE inhibition did not affect SNP responses. We conclude that acute administration of the ACE inhibitor, enalaprilat, enhances NO-mediated endothelial function in type I diabetic patients, with further improvement evident after 4 wk of enalapril therapy.

Administration, Oral↗

FHIT gene expression in human ovarian, endometrial, and cervical cancer cell lines.

The fragile histidine triad (FHIT) gene, located at 3p14.2, has been shown to be altered in numerous epithelial cancers. Because previous studies have shown a loss of heterozygosity and cytogenetic abnormalities at the 3p region in ovarian, endometrial, and cervical carcinomas, we examined the status of the FHIT gene in 14 ovarian, 8 cervical, and 4 endometrial human cancer cell lines. RNA was isolated and subjected to reverse transcription-PCR to amplify the FHIT gene transcript. Sixty-three % (5 of 8) of cervical cell lines, 14% (2 of 14) of ovarian cell lines, and none (0 of 4) of the endometrial cell lines displayed aberrantly migrating FHIT transcripts. DNA sequencing demonstrated that the aberrantly migrating bands primarily lacked exons 5, 6, and 7 (with other exon losses also observed), resulting in shorter mRNA transcripts. Southern blot analysis of DNA from five of the cervical carcinomas demonstrated alterations in four of them, three of which had exhibited no normally sized FHIT transcripts. The results suggest that the expression of the FHIT gene may be altered in cervical tumor tissue, potentially implicating this gene in cervical tumorigenesis, whereas the involvement of this gene appears to be less important in the development of ovarian and endometrial cancer.

Acid Anhydride Hydrolases↗

Complete primary structure of two splice variants of collagen XII, and assignment of alpha 1(XII) collagen (COL12A1), alpha 1(IX) collagen (COL9A1), and alpha 1(XIX) collagen (COL19A1) to human chromosome 6q12-q13.

Overlapping cDNA clones that encode the full-length human alpha 1(XII) collagen polypeptides were isolated. The long variant molecule cDNA of 9750 nucleotides (nt) contains a 9189-nt open reading frame encoding 3063 amino acid residues. The short variant molecule cDNA of 6258 nt contains a 5697-nt open reading frame encoding 1899 amino acid residues. At the amino terminus of each variant is a 24-residue signal peptide that is followed by the mature polypeptides of 3039 amino acid residues with a calculated molecular mass of 330,759 Da for the long variant and 1875 amino acid residues with a calculated molecular mass of 203,163 Da for the short variant polypeptide. The human collagen XII chains are predicted to have all the structural domains described for the molecules in chicken and mouse, including, fibronectin type III repeats, von Willebrand factor A domains, and two triple-helical domains similar to those of all the other collagen family members. The amino acid residue sequence of human alpha 1(XII) collagen showed 92% identity to the mouse chain and 78% identity to the chicken chain. The sequence of three peptide fragments of collagen XII isolated from human placenta was identical to the sequence predicted from the deduced cDNA sequence and confirms that the cDNA encodes human alpha 1(XII) collagen. An isolated genomic clone was used to map the locus of the COL12A1 gene to chromosome 6q12-q13, very close to the locus of the FACIT collagen genes COL9A1 and COL19A1. RT-PCR on a variety of cDNAs demonstrates that both variant transcripts appear in human amnion, chorion, skeletal muscle, small intestine, and in cell cultures of human dermal fibroblasts, keratinocytes, and endothelial cells. Only the small variant transcript is apparent in human lung, placenta, kidney, and a squamous cell carcinoma cell line. These results confirm the previous observations showing that collagen XII is found in collagen I-containing tissues.

Alternative Splicing↗

Development and validation of a genetic algorithm for flexible docking.

Prediction of small molecule binding modes to macromolecules of known three-dimensional structure is a problem of paramount importance in rational drug design (the "docking" problem). We report the development and validation of the program GOLD (Genetic Optimisation for Ligand Docking). GOLD is an automated ligand docking program that uses a genetic algorithm to explore the full range of ligand conformational flexibility with partial flexibility of the protein, and satisfies the fundamental requirement that the ligand must displace loosely bound water on binding. Numerous enhancements and modifications have been applied to the original technique resulting in a substantial increase in the reliability and the applicability of the algorithm. The advanced algorithm has been tested on a dataset of 100 complexes extracted from the Brookhaven Protein DataBank. When used to dock the ligand back into the binding site, GOLD achieved a 71% success rate in identifying the experimental binding mode.

Algorithms↗