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Biomedical subjects

K Cahill

Publications and source records attributed to K Cahill.

16 recordsLinked to original sources

Comparison of the effectiveness of two pressure-relieving surfaces: low-air-loss versus static fluid.

Limited research has been done to determine the effectiveness of the multitude of pressure reduction devices currently available for patient care. The purpose of this investigation was to examine the relative effectiveness of a dynamic low-air-loss (LAL) mattress and a static fluid mattress in reducing the risk of pressure ulcer development. The investigation consisted of two components: a comparative laboratory study and a retrospective clinical study. In the laboratory study, tissue interface pressures were measured on the two surfaces at three interface sites in a sample of six healthy adult volunteers. In the clinical study, a retrospective chart review was conducted to compare the actual incidence of pressure ulcer formation in a sample of 73 postoperative transplant patients who were placed on either the static fluid or LAL product. The instruments used were the Xsensor Pressure Mapping System (laboratory) and chart review tool (clinical). The main outcome measures included tissue interface pressures and incidence of pressure ulcer formation. The results were as follows: the laboratory study revealed significantly lower sacral pressures (t = -5.30, P = .003) on the low-air-loss mattress than on the static fluid mattress. Pressures did not differ significantly at the heel or trochanter sites. In the clinical study, the overall incidence of skin breakdown was 8.2%, with 5 occurrences (13.8%) in the LAL group and 1 occurrence (2.7%) in the static fluid group. However, this difference was not significant (Fisher's exact test = 0.107, P = .09). When considered jointly, the results of the two studies suggest that the static fluid and LAL products may be comparable in efficacy. Although the relatively small sample sizes used in the investigation limit generalizability, the results provide some initial direction for further clinical research in this area.

Adult↗

Transforming growth factor-beta levels in human allograft chronic fibrosis correlate with rate of decline in renal function.

BACKGROUND: Long-term renal transplant function is limited primarily by a progressive scarring process loosely termed "chronic rejection, chronic allograft nephropathy, or allograft fibrosis." Although the etiology of transplant fibrosis is uncertain, several possible factors including chronic cyclosporin A (CsA) exposure may contribute to its pathogenesis. CsA stimulates renal fibrosis perhaps through the induction of the potent pro-sclerotic growth factor, transforming growth factor beta (TGFbeta). Previously, we demonstrated that, in human transplant biopsies, acute CsA toxicity but not acute tubular necrosis is associated with elevated levels of renal TGFbeta protein. We now examine whether long-term CsA treatment (>1 year) is associated with elevated levels of intra-allograft TGFbeta and whether heightened expression of TGFbeta is clinically significant. METHODS: Using immunohistochemical techniques, we determined the relative level of expression of intrarenal TGFbeta protein in transplant biopsies. We studied biopsies obtained from 40 CsA-treated patients that were diagnosed as having chronic allograft fibrosis. Biopsies were scored as having minimal or high levels of TGFbeta. RESULTS: Seventy-two percent of patients expressed high levels of intra-allograft TGFbeta. This group of patients lost renal function at an average rate of -19.5+/-17.3 ml/min/year. In contrast, patients with minimal or no TGFbeta expression experienced a decline of only -6.2+/-4.1 ml/min/year (P=0.01). CONCLUSIONS: These results suggest that the majority of CsA-treated patients with biopsy proven chronic fibrosis have elevated levels of intra-graft TGFbeta that correlates with an increased rate of decline in renal function.

Adult↗

Differences between descriptive and multivariate estimates of the impact of Chevron Corporation's Health Quest Program on medical expenditures.

This investigation focused on alternative methods for evaluating the impact of Chevron Corporation's Health Quest Fitness Center program on medical expenditures, comparing descriptive and multivariate research designs. Many uncontrolled studies of corporate health management programs base estimates of program effectiveness on descriptive analyses such as Student's tests. Unlike more sophisticated multivariate analyses, descriptive analyses often produce biased estimates of program cost savings. To test alternative research design methods, the investigators compared inpatient and pharmacy expenditures for program participants and non-participants over a 2.5-year period, using descriptive and multivariate regression analyses. Results showed that compared with non-participants, expenditures for participants were significantly lower for subjects who used a Health Quest fitness center at least twice weekly. Previous descriptive studies suggested a much broader impact. The results underscore the need to use multivariate analyses when evaluating the financial impact of corporate health management programs, especially when randomization cannot be used to assign participation status.

Adolescent↗

A chimeric mouse/human anti-IL-2 receptor antibody with enhanced biological activities.

A chimeric mouse/human MAb against the human p55 IL-2R was constructed from Ig genes isolated from a mouse hybridoma cell line, designated AHT107. AHT107 binds to a different epitope on p55 than IL-2, and similar to observations made for other rodent anti-IL-2R antibodies that do not recognize the same or spatially related epitope as IL-2, murine AHT107 did not efficiently inhibit proliferation of T-lymphocytes in mitogen and MLR PBMC stimulation assays. In contrast, the chimeric AHT107 antibodies containing a human IgG-1 constant region had substantially more anti-proliferative activity than their murine IgG-I counterparts. Our results indicated that the human constant region of the chimeric antibodies interacted more efficiently than the murine constant region with effector components present in the PBMC cultures. This conclusion was supported by our observation that F(ab')2 generated from the chimeric antibodies did not efficiently inhibit proliferation in the PBMC assays, and the chimeric antibodies did not inhibit proliferation of an antigen specific, IL-2 dependent human T-cell clone stimulated in the absence of PBMC.

Amino Acid Sequence↗

HIV antibody testing and posttest counseling in the United States: data from the 1989 National Health Interview Survey.

To see how successful human immunodeficiency virus (HIV) counseling and testing efforts have been in testing the United States population, particularly among those at increased risk for HIV infection, we analyzed data from the 1989 National Health Interview Survey. Twenty percent of the NHIS sample (or, in terms of the general US population, an estimated 36 million persons) reported having been tested for HIV antibodies, mostly through blood donations. Although persons with increased risk of HIV infection had been tested and counseled at a much higher rate than the general population, the majority of this group had not yet been tested.

AIDS Serodiagnosis↗

Differential effects of a murine and chimeric mouse/human anti-interleukin-2 receptor antibody on human T-cell proliferation.

The preference for interleukin-2 receptor (IL-2R) expression on activated, compared with resting T lymphocytes makes the IL-2R a promising target for selective immunosuppressive therapy. To increase the potential therapeutic effectiveness of anti-IL-2R monoclonals, a chimeric mouse/human variant was constructed from Ig genes isolated from a murine anti-human IL-2R hybridoma cell line, designated AHT54. AHT54 binds to the same or spatially related epitope as IL-2 on the p55 protein that constitutes the low- and high-affinity forms of IL-2R. Although the murine and chimeric AHT54 antibodies inhibited cell-surface binding of IL-2 to the same extent, the chimeric antibodies containing a human IgG1 constant region had substantially more anti-proliferative activity than their murine IgG1 counterparts. Our results indicated that the human constant region of the chimeric antibodies interacted more efficiently than the murine constant region with effector components present in peripheral blood mononuclear cells (PBMC).

Animals↗

Gene-sized macronuclear DNA molecules are clustered in micronuclear chromosomes of the ciliate Oxytricha nova.

Following the sexual phase of its life cycle, the hypotrichous ciliate Oxytricha nova transforms a copy of its chromosomal micronucleus into a macronucleus containing short, linear DNA molecules with an average size of 2.2 kilobase pairs. In addition, more than 90% of the DNA sequences in the micronuclear genome are eliminated during this process. We have examined the organization of macronuclear DNA molecules in the micronuclear chromosomes. Macronuclear DNA molecules were found to be clustered and separated by less than 550 base pairs in two cloned segments of micronuclear DNA. Recombinant clones of two macronuclear DNA molecules that are adjacent in the micronucleus were also isolated and examined by DNA sequencing. The two macronuclear DNA molecules were found to be separated by only 90 base pairs in the micronuclear genome.

Animals↗

Yellow fever immunity surveys in northern Uganda and Kenya and eastern Somalia, 1966-67.

Recent epidemics of yellow fever in eastern Africa have stimulated serological surveys in the Karamoja district of Uganda, the northern frontier district of Kenya and the Giohar district of Somalia. All sera collected in the surveys were screened for group B arbovirus antibody using the HI test. Yellow fever immunity was confirmed by the mouse-protection test.No yellow fever immunity was found in sera collected from a residential tribal group at Karamoja but a small number of samples from persons who had previously lived outside the district showed immunity. Immunity was detected in sera from areas of the Northern Frontier district of Kenya. It is thought that this immunity may, in some areas, have resulted from extensions of the Ethiopian epidemic of 1960-62 into the region, but in another area of the district the immunity seems to have arisen from continuing focal transmission within Kenya. Yellow fever immunity was also detected in Somalia.

Adolescent↗

"Is this a dagger I see before me?"--an audit of stabbings and gunshot wounds in Limerick.

BACKGROUND: According to a recent study in Cardiff, the incidence of stab wounds is 14 per 100,000 population per annum. No such figures are available for Ireland. AIM: To evaluate the incidence, type of injury, medical consequences and outcome of patients with stab or gunshot wounds presenting to the Mid-Western Regional Hospital, Limerick, over a 12 month period. METHOD: A retrospective case study of all stab and gunshot wounds presenting over a 12 month period. RESULTS: Out of 62,000 new presentations to the Accident and Emergency (A&E) department, 101 (0.16%) were stabbings, giving an incidence of 33 per 100,000 population. Twenty-six patients required surgical intervention. There were three deaths. There were 10 gunshot wounds, of which 40% required surgical intervention, with no mortalities. CONCLUSION: The incidence of stab wounds presenting to our institution is high. Although constituting a small percentage of presentations to the A&E department they result in considerable morbidity and surgical activity.

Adolescent↗