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Biomedical subjects

J Rice

Publications and source records attributed to J Rice.

At least 91 records · Page 5Linked to original sources
PubMed1997

Correlation of major histocompatibility complex with opportunistic infections in simian immunodeficiency virus-infected rhesus monkeys.

The role of the major histocompatibility complex (MHC) in the pathogenesis of AIDS is complex because of compounding variables within the virus, host, and environment. Important variables can be controlled by using the experimental animal model of AIDS induced by simian immunodeficiency virus in rhesus monkeys (Macaca mulatta). We studied whether the MHC type influenced which opportunistic infections arose in an individual monkey. Several associations were found. For example, cytomegalovirus was strongly associated with Mamu-B6 (p < 0.001), whereas Cryptosporidium was associated strongly with Mamu-DR3 (p < 0.001). We also found that having one opportunistic infection increased the risk of having another.

Alleles↗
PubMed1997

Effect of short-term treatment with a monoclonal antibody to P-selectin on balloon catheter-induced: intimal hyperplasia, re-endothelialization, and attenuation of endothelial-dependent relaxation.

The effects of an anti-P-selectin monoclonal antibody (MAb, PB1.3; Cytel Corporation) on neoendothelialization; neoendothelial function, as evidenced by acetylcholine-induced relaxation (nitric oxide formation); and intimal hyperplasia following embolectomy catheter-induced injury to the rabbit thoracic aorta were investigated. Catheter injury was induced in two groups of New Zealand White rabbits. One group received no treatment, while the second group received short-term treatment with the MAb (i.p., immediately before and 12 h after induction of catheter injury). A third group underwent a sham operation and served as uninjured controls. Following sacrifice at 2 weeks after injury, aortic rings were assessed for degree of intimal hyperplasia, neoendothelial morphology (scanning electron microscopy), and acetylcholine-induced relaxation. Aortic tissue from catheter-injured animals that received treatment exhibited improved neoendothelial morphology, as compared with tissue from untreated but catheterized animals; however, no statistically significant attenuation of the hyperplastic response or improvement in the attenuated neoendothelial-dependent acetylcholine-induced relaxant response that is characteristic of neoendothelium that forms after catheter denudation was observed. These data suggest that short-term attenuation of P-selectin-mediated polymorphonuclear leukocyte (PMN)/endothelium, PMN/platelet interactions, and/or thrombin formation beneficially affects neoendothelialization of the vascular wall following balloon catheter-induced injury.

Animals↗
PubMed1996

Parent-of-origin effect in transmission of bipolar disorder.

Recently, possible involvement of a parent-of-origin effect in the transmission of bipolar disorder has been suggested. We examined the possible contribution of parent-of-origin effect by using data from a large family and family history study of bipolar patients in the Collaborative Depression Study. In 276 probands with bipolar I disorder, family histories were examined using three diagnostic criteria: 1) bipolar I disorder, 2) bipolar I or bipolar II disorder, and 3) bipolar disorders or recurrent unipolar depression for parents and siblings. An excess of affected mothers was not observed when unipolar depression was excluded. Age-at-onset was significantly lower in probands having a father with bipolar disorders or recurrent unipolar depression than in probands with an affected mother. This difference was not observed when unipolar depression was excluded. There was no significant difference of prevalence rate in children of affected mothers and those with affected fathers. These data do not support the contribution of parent-of-origin effect in the transmission of bipolar disorder.

Adult↗
PubMed1996

Validation of a method to estimate age-specific human immunodeficiency virus (HIV) incidence rates in developing countries using population-based seroprevalence data.

The authors have conducted an analysis to validate a computer model that uses age-specific human immunodeficiency virus (HIV) prevalence data to estimate age-specific HIV incidence rates. Data for the analysis are from a cohort study of volunteer male workers in Bujumbura, the capital city of Burundi. Testing for HIV prevalence was conducted at baseline, and HIV-negative subjects were retested annually from 1990 to 1993 to determine rates of seroconversion. Input parameters required for the model include age-specific HIV prevalence and estimates of age-specific mortality rates for HIV-negative and HIV-positive subjects. Incidence rate estimates from the model were 2.0, 2.7, 1.0, 1.5, and 1.8 per 100 person-years for age groups 20-24, 25-29, 30-34, 35-39, and 40-44 years, respectively. Corresponding observed incidence rates for the same age groups were 1.6, 1.8, 2.2, 2.3, and 1.5 per 100 person-years, respectively. Most observed incidence rates fell within the 95% confidence limits of the model estimates. Expected numbers of cases within age intervals did not differ significantly from observed number of cases. The authors conclude that the model proved to be successful in approximating observed incidence rates and that it is a useful tool, particularly in countries where prevalence data are available and where HIV prevalence has stabilized, which is when the underlying assumptions in the model are best met. The model provides crucial information about incidence rates that might not be evident from prevalence data alone.

Adolescent↗
PubMed1996

Modeling nucleotide evolution: a heterogeneous rate analysis.

A new model of molecular evolution is introduced that allows for heterogeneous rates across the sequence positions. The development of this model was motivated by two issues: first, a number of studies have shown that the positions in a DNA sequence evolve at different rates, and second, it has been shown that not accounting for this heterogeneity can lead to biased estimates of evolutionary parameters. The authors generalize the Markovian model of molecular evolution to allow for heterogeneous rates and explore some of the consequences of such a model. In particular, they quantify the biases incurred by incorrectly assuming an equal-rate model and consider what can be learned about evolutionary parameters under a heterogeneous model.

Biological Evolution↗
PubMed1996

Brain protein and alpha-ketoglutarate dehydrogenase complex activity in Alzheimer's disease.

To determine whether the reduction in brain alpha-ketoglutarate dehydrogenase complex activity in Alzheimer's disease (AD) is associated with an abnormality in one of its three constituent enzyme subunits, we measured protein levels of alpha-ketoglutarate dehydrogenase (El), dihydrolipoamide succinyltransferase (E2), and dihydrolipoamide dehydrogenase (E3), in postmortem brain of 29 patients with AD (mean age, 73 years; age range of onset, 50-78 years) and 29 control subjects. In the AD group protein levels of all three subunits were significantly reduced by 23 to 41% in the temporal cortex, whereas in the parietal cortex (El: -28%; E3: -32%) and hippocampus (E3: -33%) significant changes were limited to El and E3. alpha-Ketoglutarate dehydrogenase complex activities were more markedly reduced (by 46-68%) and did not correlate with protein levels, suggesting that decreased enzyme activity cannot be primarily explained by loss of alpha-ketoglutarate dehydrogenase complex protein. We did not find two E2 immunoreactive forms in the brain of any patient, as has been reported in fibroblasts of patients with very-early-onset chromosome 14-linked AD. We conclude that brain protein and activity levels of alpha-ketoglutarate dehydrogenase complex are reduced in patients with AD who have onset after 50 years and suggest that these changes, which are also observed in other human brain disorders, may represent a nonspecific consequence of different neurodegenerative processes. Nevertheless, reduced levels of this rate-limiting enzyme of the Krebs cycle could contribute to the brain neurodegenerative mechanisms of AD.

Age Factors↗
PubMed1996

Cocaine analgesia: an in vivo structure-activity study.

Hot plate testing of rats was performed to determine the optimal analgesic doses of intracerebroventricularly (ICV) administered cocaine, significant cocaine metabolites, and selected structurally similar molecules. Optimal, (subseizure) analgesic doses for cocaine and selected cocaine analogues were (in microM): cocaine, 0.37; cocaethylene, 0.09; benzoylecgonine, 0.35; norcocaine, 0.43; and ecgonine, 2.1. Ecgonine methyl ester was not analgesic at < or = 3.7 microM. These results, in conjunction with findings on other structurally similar molecules suggest that, of the molecules tested, (a) a hydrophobic group at the C-3 attached carbon is critical for analgesia; (b) a hydrophobic C-2 ester group can enhance analgesic activity (e.g., cocaethylene); (c) the N-methyl position is minimally important for analgesia; and (d) isomeric configurational changes can influence analgesia.

Anesthetics, Local↗
PubMed1996

Scaphoid osteochondroma mimicking carpal coalition.

We present the case of a 10-year-old girl who presented with a block to wrist abduction. Plain radiographs of the wrist suggested a coalition between the carpal bones. A CT scan, however, revealed the presence of an osteocartilaginous lesion on the distal pole of the scaphoid. This was resected and histology showed it to be an osteochondroma.

Bone Neoplasms↗
PubMed1995

Predictors of HIV disease progression in women.

A retrospective cohort study was conducted to analyze variables predictive of acquired immunodeficiency syndrome (AIDS), as defined by the Centers for Disease Control (CDC) in 1987, and death in 224 women infected with the human immunodeficiency virus (HIV) who were evaluated through two HIV outpatient programs in New Orleans between January 1987 and December 1991 and followed through February 1993. Variables predictive of AIDS in a multivariate proportional hazards model were an entry CD4 cell count < 200/mm3 (adjusted RR 8.2, 95% CI 3.2, 20.9) and rapid CD4 cell count decline (adjusted RR 6.0, 95% CI 2.4, 15.5). A baseline AIDS diagnosis (by the CDC 1987 definition) was highly predictive of death (RR 36.3, 95% CI 15.7, 70.1). In multivariate analyses none of the relative risks for predictive variables remained significant if adjusted for a diagnosis of AIDS at entry. Although immunological parameters were predictive of early HIV disease progression, an AIDS diagnosis was the strongest prognostic indicator of death in a cohort of North American women.

Acquired Immunodeficiency Syndrome↗
PubMed1995

Effect of light therapy on salivary melatonin in seasonal affective disorder.

To investigate the role of a light-induced advance in the timing of the melatonin rhythm in seasonal affective disorder, 11 depressed patients underwent 2 weeks of light therapy with full spectrum or cool white light. Evening saliva samples were collected before and after each week of treatment and assayed for melatonin to determine the time of onset of nocturnal secretion. Both treatments reduced depression scores, advanced the timing of the melatonin rhythm, and increased melatonin concentrations. Time of onset of the nocturnal increase in melatonin did not differ between clinical responders and nonresponders, suggesting that a phase advance in the onset of nocturnal melatonin secretion is not sufficient to induce clinical remission in seasonal affective disorder.

Adult↗
PubMed1995

A preliminary comparison of two perennially ice-covered lakes in Antarctica: analogs of past Martian lacustrine environments.

Perennially ice-covered lakes in the Antarctic have been suggested as analogs to lakes which may have existed on the surface of Mars 3.5 billion years ago. During the 1991-1992 austral summer, a joint Russian/American research effort was directed at studies of ice-covered lakes in the Bunger Hills Oasis, Antarctica (66 degrees S, 100 degrees E). The primary objective of the expedition was to investigate this ice-free area for features analogous to ancient martian environments that may have been capable of supporting life and to compare the ice-covered lakes of the Bunger Hills with those in the McMurdo Dry Valleys of southern Victoria Land (77 degrees S, 166 degrees E) as part of the continuing studies of Antarctic-Mars analogs.

Antarctic Regions↗
PubMed1995

Evaluation of a program to remove barriers to public health care for women with HIV infection.

To facilitate access to care for HIV-infected women, a maternal-child program was started at an HIV outpatient clinic in New Orleans. The program consisted of free child care and transportation, separate waiting and examination rooms, female care providers, merged visits for mother and child, and on-site colposcopy services. This study evaluates the efficacy of the program on improving attendance at the clinic by follow-up of 143 women and 557 men (serving as controls). Multivariate models were adjusted for history of intravenous drug abuse, race, age, CD4 cell count, staging of disease, and time in the clinic. Half of the clients achieved high attendance rates. Women were as likely as men to achieve high attendance rates before the interventions, but more likely to do so at both 6 months and 1 year postintervention (after adjustment for the other variables). These results suggest that responding to special gender-related needs can improve women's attendance for clinic visits.

Adult↗
PubMed1995

Affective illness in family members and matched controls.

As part of the US National Institute of Mental Health Collaborative Program on the Psychobiology of Depression study, a subset of 460 randomly chosen relatives of affectively ill probands were compared to a control group matched by the acquaintanceship method. The rate of major affective disorder in relatives was found to be 36%; the rate among controls was 28%. Relatives were also found to have significantly higher rates of bipolar II disorder, any Research Diagnostic Criteria (RDC) affective disorder and any RDC mental disorder. All of these rates were found to be significantly higher when female relatives were compared with their acquaintances, but only the rate of any RDC mental disorder was higher when this comparison was made in men. The acquaintanceship method enabled the selection of a control group that closely resembled the relatives, probably to the extent of "overmatching". When the match was evaluated to determine whether relatives tended to select comparably ill (or well) acquaintances, this was found to be the case only for alcoholic and never mentally ill relatives.

Adult↗
PubMed1995

Effective hospital leadership for quality: theory and practice.

Hospitals need excellent leadership to be efficient in the use of scarce stakeholder resources and to be effective in the competitive provision of services to multiple customers. This study was conducted with the cooperation of the executive team at a large government-funded hospital in Brisbane. It focused on understanding the conceptual models of leadership held by members of the executive and comparing this model with an externally derived model of leadership. Performance on the local model was estimated by cross-linking performance assessment on the external model. Members of the executive espoused, and were also rated by others in the hospital as practising, to a moderate degree, a transformational style of leadership. An overall evaluation of quality practice in the hospital revealed the use of data, the understanding of processes and the formation of supplier partnerships as the areas of hospital activity most limiting the ability to improve. The implications of the conceptual model and performance levels are discussed in relation to the introduction of quality management practice in the hospital, and in terms of management development. A complementary paper focusing on quality implementation as perceived at different staff levels in the hospital is in preparation.

Australia↗
PubMed1995

Compliance with public sector HIV medical care.

Despite the availability of free or low-cost public sector human immunodeficiency virus (HIV) health-care services, important inequities in utilization exist. This study examined two measures of compliance with HIV medical care: attendance of scheduled outpatient visits and use of the emergency room. Clients of two public HIV outpatient clinics were followed from time of health-care initiation to either death or the end of the study. The association of race, sex, age, and injection drug use (IDU) with these measures were examined in multivariate logistic regression. Models were adjusted for disease staging at time of entry and for length of follow-up time in clinic. Of 1824 clients followed, 15% failed to attend scheduled visits and 18.1% had at least one emergency room visit. Clients who missed visits were more likely to be African American, to have a history of IDU, and to have a CD4 cell count < 500/mm3 or an acquired immunodeficiency syndrome (AIDS)-defining opportunistic infection at entry. They were also more likely to have > or = 12 months of follow-up time in the HIV clinic, but were less likely to have entered into health care from an early intervention clinic. Clients who had at least one emergency room visit were more likely to be African American, female, IDU, and under 22 years of age; these clients were also more likely to have entered with CD4 < 200/mm3 or with an opportunistic infection, and to have > or = 12 months of follow-up in the clinic.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗