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Biomedical subjects

J B Martin

Publications and source records attributed to J B Martin.

At least 73 records · Page 4Linked to original sources
PubMed1992

[Treatment of venous thrombosis with low molecular weight heparin and fluindione].

Thirty-one consecutive patients with deep vein thrombosis were treated with Fraxiparine, a low molecular weight heparin, and fluindione, an oral anticoagulant prescribed at an early stage. Despite the weight/biological effectiveness ratio, the dose of Fraxiparine had to be adjusted in 46 percent of the patients to remain within the therapeutic range selected (0.5 to 1 antiXa/ml units). The early administration of fluindione reduced the duration of heparin therapy to 5.75 days. Using a prescription guide on days 2 and 4 might improve the safety of the fluindione induction.

Adult↗
PubMed1992

Neurologic manifestations of hypothalamic disease.

The hypothalamus, in addition to regulating the anterior and posterior pituitary, controls water balance through thirst, regulates food ingestion and body temperature, influences consciousness, sleep, emotion and other behaviors. Much has been learned of these effects in human disease through the clinical manifestations that occur with hypothalamic lesions. This study reviews the clinical pathologic correlations that have been made in recent years showing that regions of the hypothalamus exert functions in humans that are similar to those identified in experimental animals. Clinical pathologic correlations have not always provided precise analysis of hypothalamic function. The hypothalamus is small and often lesions that come to clinical attention achieve considerable size before their recognition, making local anatomic dissections of the effects of the lesions difficult. Nevertheless, the use of modern non-invasive techniques including CT scans and magnetic resonance imaging (MRI) have provided new information not previously available. This paper reviews several cases of hypothalamic disorder recognized recently. (1) A 33-year-old black man with hypothalamic sarcoidosis. Manifestations of hypothalamic dysfunction included panhypopituitarism, aggressive hyperphagia, polydipsia (partially due to hyperglycemia secondary to diabetes mellitus), drowsiness, depression, and irritability. (2) A 37-year-old woman with a large intrahypothalamic tumor (biopsy showed pituitary adenoma), with drowsiness, poikilothermia, lack of satiety, confusion, and memory loss. She becomes depressed when she is transiently more alert (as after hypertonic contrast-dye infusion). (3) A 60-year-old man with hypothalamic compression by a pituitary tumor, associated with syndrome of inappropriate ADH (SIADH), severe anorexia, memory loss, but preserved thirst. After surgical decompression of the tumor his appetite acutely recovered, but he developed severe hypo(poikilo)thermia. (4) A 45-year-old woman with a suprasellar craniopharyngioma presented with severe drowsiness, hyperphagia, depression, and memory loss post-operatively, which responded to antidepressants (except for the memory loss). She had extremely labile blood pressures and serum Na for about 1 week post-operatively.

Adult↗
PubMed1992

Cancer pain: a multidimensional perspective.

Cancer pain has traditionally been studied from a unidimensional/medical model. However, limitations of the medical model have led researchers to the development of multidimensional models of cancer pain. The current manuscript describes a multidimensional model of cancer pain with six components: physiological, sensory, affective, cognitive, behavioral and sociocultural. Research relevant to each component of the model is reviewed with an emphasis on future research directions.

Humans↗
PubMed1992

Women's attitudes toward careers in academic medicine at the University of California, San Francisco.

In order to identify the concerns and possible barriers for women considering careers in academic medicine, in 1990 the authors surveyed both men and women medical students, housestaff, postdoctoral students, and junior faculty at The University of California, San Francisco (UCSF). The authors achieved a 58% response rate from students and faculty, a 21% response rate from postdoctoral students, and a 15% response rate from housestaff. Results indicated that women at all levels were less interested in academic careers than were their male colleagues. Concerns about balancing family responsibilities, clinical practice, and teaching in addition to the research required of an academic career were mentioned most frequently. Women, especially those among the housestaff and junior faculty, reported fewer mentor relationships and role models. The authors discuss these findings in relation to other studies and describe what they are doing to foster women's interest and success in academic medicine at UCSF.

Attitude↗
PubMed1992

Information systems for evaluating the quality of prescribing.

OBJECTIVE: An important purpose of drug usage evaluation (DUE) is to provide feedback to physicians on population-based prescribing patterns and problems. This article has four objectives: (1) to outline prescribing information requirements for a computerized information system in terms of the variables needed for DUE, (2) to describe existing computerized information systems that collect and organize prescribing data, (3) to assess existing systems in terms of their capacity to provide the requirements outlined in our first objective, and (4) to suggest design changes to existing systems that would improve the DUE process. ANALYSIS: There are several existing DUE information systems that have some capacity to evaluate the quality of prescribing in specific populations (e.g., veterans, public and private insured groups, hospital service areas). Shortcomings of most DUE information systems include patient identification problems, defects in database design, and lack of software to identify prescribing problems and perform statistical analysis. CONCLUSIONS: DUE information systems could be used and upgraded to enable physicians to develop more rational prescribing rules from population data that would improve the quality of prescribing.

Drug Prescriptions↗
PubMed1992

Design and validation of a critical care simulation model.

The high costs of building, equipping, and staffing critical care beds, coupled with more restrictive reimbursement policies, are forcing hospital administrators to seek ways for determining accurately the number of critical care beds needed. Existing critical care bedsizing models do not capture the complexity of today's critical care environment, nor have they been formally validated using actual hospital performance data. The study described herein was designed to address these needs. A GPSS/H simulation model was developed and validated, and includes the flow of patients through the study hospital's operating rooms, post-anesthesia recovery unit, three intensive care units, and two intermediate care (stepdown) units.

Bed Occupancy↗
PubMed1992

Identification of factors associated with hospital readmission and development of a predictive model.

Multiple hospital admissions, especially those related to the chronically ill, represent a particular challenge to both the acute and long-term care sectors to identify effective methods of resource management. This study analyzes the multiple admission patterns associated with a cohort of 4,219 adult medical-surgical patients discharged alive from a community teaching hospital in Michigan. The sample was divided into two groups: 3,818 patients who survived and 392 who expired during the one-year follow-up period. For the surviving subsample, the characteristics found to be directly associated with the likelihood of readmission included increased age, advanced stage of disease, greater index-episode length of stay, discharge by an internist rather than a surgeon, Medicare as expected source of payment, decreased physician age, discharge to a community setting, and increased number of prior hospital episodes. For the subsample who died, only one explanatory variable was significantly associated with an increased likelihood of readmission-discharge to a community setting (with or without home care) rather than a nursing home. The article includes illustrates of the importance of decisions regarding posthospital, long-term care services on the likelihood of rehospitalization.

Adult↗
PubMed1991

The role of private body consciousness and anxiety in the report of somatic symptoms during magnetic resonance imaging.

The present study examined an information processing model of symptom reporting (Ahles, Cassens, & Stallings, Journal of Behavior Therapy and Experimental Psychiatry 18, 215-222, 1987) in a medical sample during an anxiety-arousing diagnostic medical evaluation. The predisposition to attend to physical sensations (private body consciousness), state anxiety, and symptom reporting were assessed in 47 patients undergoing a magnetic resonance imaging (MRI) procedure. The results of this study provide further support for the information processing model; the interaction between private body consciousness and state anxiety significantly predicted symptom reporting during the MRI. The pattern of results points to attention to physical sensations and anxiety as important mediators of symptom reporting.

Adult↗
PubMed1991

Training physician-scientists for the 1990s.

The author describes a paradox: on the one hand, remarkable strides have been made in biomedical research that have created unparalleled opportunities for progress in the understanding, prevention, and treatment of human diseases; yet on the other hand, too few people are being adequately trained to actualize the promise of these advances. Concerns that have been raised in the past concerning the training of physician-scientists are reviewed and general statements are made about their current availability. The status and health of M.D.-Ph.D. programs are discussed, because many think this kind of program is an important mechanism for training the biomedical researchers of the future. New initiatives under way to encourage careers in research are considered and recommendations are made for the future support of research training and encouragement of the exceptional young people who are entering the research pipeline.

Attitude of Health Personnel↗
PubMed1991

Neonatal treatment with monosodium glutamate: effects of prolonged growth hormone (GH)-releasing hormone deficiency on pulsatile GH secretion and growth in female rats.

Administration of monosodium glutamate (MSG) to neonatal rodents produces permanent lesions of hypothalamic arcuate neurons that secrete GH-releasing hormone (GHRH). The present study was intended to determine the consequences of GHRH deficiency on the pulsatile GH secretory pattern and growth in MSG-treated female rats and to compare these effects with those observed in male littermates. Male and female rats were injected with MSG [4 mg/g body wt (BW), sc] or saline (controls) on days 2, 4, 6, 8, and 10 after birth. Immunoreactive GHRH concentrations were decreased in the hypothalamus (by 60%) and in the median eminence (by 95%) of adult male and female MSG-treated rats. In contrast, somatostatin concentrations were unaffected. BW and linear growth were severely impaired in male MSG-treated rats, but in MSG-lesioned females BW was not different from controls, and the attenuation of longitudinal growth was less severe and the obesity more pronounced than in males. These sex differences occurred despite similar reductions (by 55%) in serum insulin-like growth factor I concentrations in male and female MSG-treated rats. MSG treatment also produced decreases in pituitary wt and GH content (by 60%), independent of sex. Pulsatile GH secretion was studied by serial blood sampling of chronically cannulated, freely moving rats. Plasma GH patterns were analyzed by the PULSAR program. Compared to controls, treatment with MSG led to a marked inhibition (by 90%) of GH secretion in both sexes. Significant reductions in GH pulse amplitude (-95%) and pulse duration (-62%) were observed in males, whereas pulse amplitude (-85%), pulse frequency (-67%), and baseline GH concentrations (-80%) were markedly reduced in females. The GH responses to an iv bolus injection of rat GHRH (1 microgram/rat) was severely blunted in both male and female MSG-treated rats. This study demonstrates that GHRH deficiency in female rats results in a marked inhibition of GH pulses, as in males, but also causes severe and sex-specific reductions in GH basal secretion and pulse frequency. These observations suggest that hypothalamic GHRH secretion in female rats is more continuous than in males and is a determinant of the elevated interpulse secretion of GH. Moreover, body wt and linear growth are less severely affected by arcuate lesions in female animals, compared to males. These sex-related differences in growth rates may result in part from the tendency of female MSG-lesioned rats to become more obese than males, and the development of obesity, in turn, may antagonize the factors that tend to slow linear growth.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1991

Continuous personnel scheduling algorithms: a literature review.

Hospitals frequently use personnel scheduling options as recruiting and retention instruments. The successful application of these personnel scheduling tools, whether developed in-house or purchased from vendors, requires appreciation of the interrelationships of three basic manpower decisions--staffing, personnel scheduling, and allocation. This article introduces these basic relationships and their influence on the development of satisfactory personnel schedules. Next, it reviews published personnel scheduling algorithms, applicable to hospital operations, within the context of the three manpower decisions. It is proposed that scheduling algorithms be classified by type of schedule produced (cyclic or noncyclic); and technique used (heuristic, mathematical programming, or self-scheduling). The characteristics of each classification are discussed. Considerations for the development of new personnel scheduling algorithms are also presented.

Algorithms↗
PubMed1990

A natural-abundance 13C-NMR study of Dictyostelium discoideum metabolism. Monitoring of the spore germination process.

Amoebae and spores of the cellular slime mold Dictyostelium discoideum have been investigated by natural-abundance proton-decoupled 13C-NMR spectroscopy. Axenically grown vegetative amoebae have been found to contain, as prominent metabolites, the polyamines 1,3-diaminopropane (3.2 mM), putrescine (9.4 mM) and spermidine (1.7 mM). We also detected lactic acid (4.4 mM) and the following amino acids as free metabolites in concentrations ranging over 1-3 mM: glycine, alanine, glutamine and glutamate. The glycogen level is highly dependent upon growth state, being below the level of NMR detection in early-exponential cells and reaching about 110 mM glucose equivalents in plateau-phase cells. Dormant spores contained high amounts of trehalose (50 mM), glutamine (73 mM) and glutamate (20 mM). The latter two compounds were not reported previously to be present in such high concentrations in Dictyostelium spores. Germination induced by heat-shock activation was monitored by 13C NMR. No change in the major components occurred during the activation step. The progressive disappearance of trehalose during germination correlated with the decrease of glutamine and glutamate. In general, the data suggest that germinated spores contain a composition of free metabolites very similar to that of starved vegetative amoebae.

Amines↗
PubMed1990

Characterization and mechanism of glutamate neurotoxicity in primary striatal cultures.

Excitatory amino acids may play a role in the pathogenesis of cell death in neurodegenerative diseases, including Huntington's disease (HD). In an attempt to develop a tissue culture model for HD, the toxicity of glutamate was examined in primary striatal cultures derived from newborn rats. Morphological criteria were used to determine the toxic effects of glutamate in 6-, 12-, and 18-day-old cultures which were examined before and after 1-3 h of exposure to glutamate. Although younger cultures demonstrated little susceptibility to glutamate relative to controls, the number of neurons in older cultures was significantly depleted in the presence of glutamate. Glutamate toxicity was dose-dependent, with an ED50 of approximately 300 microns glutamate, and a maximal effect was observed within 3 h of initial exposure. Affected neurons demonstrated somal swelling within 1 h of glutamate exposure and disruption of neuritic processes and somal integrity within 3 h. Cell death was significantly increased by raising the extracellular calcium concentration and could be decreased by the addition of magnesium to the incubation medium. Moreover, the N-methyl-D-aspartate (NMDA) receptor agonist, quinolinic acid, showed a toxicity profile similar to that of glutamate. The NMDA receptor competitive antagonist, 2-amino-5-phosphonovalerate (APV) significantly reduced toxicity, albeit incompletely. An additional component of glutamate mediated toxicity in striatal cultures could be explained by activation of non-NMDA receptor subtypes. These in vitro studies indicate that glutamate is toxic to a subset of mature striatal neurons in the absence of a glutamatergic afferent input, and that this toxicity is mediated partially by the NMDA receptor, with an additional component due to non-NMDA receptors.

2-Amino-5-phosphonovalerate↗