Search PubMed⌕ Search

Biomedical subjects

J Morrissey

Publications and source records attributed to J Morrissey.

At least 109 records · Page 6Linked to original sources
PubMed1999

Dosimetry in mice exposed to 1.6 GHz microwaves in a carrousel irradiator.

We have developed a carrousel irradiator for mice which delivers a head-first and near-field radiofrequency exposure that more closely simulates cellular telephone and radio use than conventional whole body exposure systems. Mouse cadavers were placed on the carrousel irradiator and exposed with their noses 5 mm from the feedpoint of a 1.6 GHz antenna. Local measured specific absorption rates (SAR) in brain regions corresponding to the frontal cortex, medial caudate putamen, and midhippocampal areas were 2.9, 2.4, and 2.2 W/kg per watt of irradiated power, respectively. In addition, average SAR was estimated to be 3.4 W/kg per watt along the sagittal plane of the brain, 2.0 W/kg per watt along the sagittal plane of the body, and between 6.8 and 8.1 W/kg per watt at peak locations along the sagittal plane at the body surface. This detailed SAR information in mice is critical to the interpretation of biological studies of IRIDIUM exposure, and similar analysis should be included for all studies of in vivo exposure of small animals to microwaves.

Absorption↗
PubMed1999

Characterization of rural mental health service systems.

This paper explores two mental health systems in rural North Carolina that provide services to people with severe mental disorders. Recent findings show rural people with mental disorders receive less mental health care than their urban counterparts. This study asks whether rural service systems differ from urban systems in the way that their services are coordinated and structured. A popular conception is that public mental health systems in the United States are uncoordinated with many services provided outside the mental health sector. Rural service providers are seen as even more dependent on nonspecialized mental health providers than their urban counterparts. While many rural service barriers are attributed to the rural environment, little is known about rural service systems and how their organization might contribute to or negate barriers to care. Social network methods were used in this study to compare two rural with four urban systems of care. Findings confirm that mental health systems fit the de facto hypothesis, but that rural systems differ in ways not anticipated by the hypothesis. Rather than being more dependent on nonmental health agencies, rural mental health agencies are more interdependent.

Health Services Needs and Demand↗
PubMed1999

Role of TNFR1 and TNFR2 receptors in tubulointerstitial fibrosis of obstructive nephropathy.

Unilateral ureteral obstruction (UUO) results in tubulointerstitial fibrosis of the obstructed kidney. In this study, we report the contribution of tumor necrosis factor-alpha (TNF-alpha) to the fibrosis that develops after ureteral obstruction. Mice in which individual TNF-alpha receptors TNFR1 or TNFR2 had been genetically knocked out were used, and results were compared with mice of C57Bl/6 background after 5 days UUO. Both kidneys were removed and examined histologically for changes in interstitial volume (Vv(int)), collagen IV deposition, alpha-smooth muscle actin (alpha-SMA) matrix score, nuclear factor-kappaB (NF-kappaB) activity, and TNF-alpha mRNA levels. We found that the Vv(int) of contralateral unobstructed kidneys averaged approximately 7% and was indistinguishable among the three genotypes of mice. Vv(int) of ureteral obstructed kidney of C57Bl/6 mice averaged 33 +/- 3.9% after 5 days of UUO. Vv(int) of obstructed kidneys of TNFR1 mice was significantly reduced to 19.4 +/- 3.1%, whereas that of TNFR2 mice was significantly decreased to 25.4% +/- 4.8%. There was a modest but significant difference between Vv(int) of TNFR1 and TNFR2 (P < 0. 047). Both collagen IV and alpha-SMA matrix scores were decreased significantly in obstructed kidney of TNFR1 mouse compared with that of C57Bl/6 and TNFR2 mice. Nuclear extracts prepared from kidney cortex were found to have a significant increase in NF-kappaB binding activity in obstructed kidney compared with contralateral kidney. Individual knockout of the TNFR1 or TNFR2 genes resulted in significantly less NF-kappaB activation compared with the wild type, with TNFR1 being less than TNFR2 knockout. There was a significant increase in TNF-alpha mRNA in the kidney with ureteral obstruction in all three genotypes. TNFR1 knockout displayed a significant reduction in amount of TNF-alpha mRNA induced compared with wild-type or TNFR2 knockout mice. Treatment of TNFR1 knockout mice with an angiotensin converting enzyme inhibitor further decreased Vv(int) and TNF-alpha mRNA induction, suggesting an interaction of ANG II and TNF-alpha systems. These results suggest that TNF-alpha contributes, in part, to changes in interstitial volume, myofibroblast differentiation, and NF-kappaB activation in the kidney during ureteral obstruction. These changes appear to be mediated through both TNFR1 and TNFR2 gene products with effects through the TNFR1 receptor predominating. Furthermore, ANG II appears to stimulate TNF-alpha pathophysiological events leading to renal fibrosis.

Actins↗
PubMed1998

See you in court. Damage inflicted by the Y2K bug threatens to become a dream for litigators but a nightmare for healthcare executives.

Most hospitals and health systems perceive and treat the year-2000 faulty computer code as a technical problem, but it is a high-level management problem. If hospitals don't start preparing comprehensively, they will face a host of consequences. Experts say spillover will extend into business issues, finances and liability. But providers must choose their most important priorities and develop contingency plans.

Chronology as Topic↗
PubMed1998

Healthcare international.

How people are treated when they need medical care depends on where in the world they are. In deciding which tools of the medical trade are used to treat disease and when they're used, location is paramount. A country's social policy, healthcare payment systems and cultural factors bear heavily on the utilization of medical technology. The cover story kicks off the magazine's third international healthcare section.

Global Health↗