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Biomedical subjects

J Wood

Publications and source records attributed to J Wood.

At least 217 records · Page 12Linked to original sources
PubMed1988

Upper gastrointestinal endoscopy after cardiac transplantation.

Three hundred four patients have undergone cardiac transplantation at the University of Pittsburgh since 1980. Twenty patients have required 27 upper gastrointestinal (GI) endoscopic procedures. After heart transplantation the primary indications for endoscopy were epigastric pain (six patients with gastritis, one with multiple shallow gastric ulcers, and one with normal test results), mild upper GI bleeding (four patients with esophagitis, two with gastritis, and two with multiple shallow gastric ulcers), dysphagia and odynophagia (two patients with esophagitis), persistent nausea and vomiting (one with normal test results), lower GI bleeding (one with normal test results), and routine follow-up (one with normal test results). After heart-lung transplantation the primary indications for the endoscopy were massive upper GI bleeding (three patients with actively bleeding duodenal ulcers), dysphagia and odynophagia (one patient with esophagitis), mild upper GI bleeding (one patient with gastritis), and routine follow-up (one patient with normal test results). No complications resulted from endoscopy. The procedures were performed in the GI suite without cardiac monitoring. Prophylactic antibiotics were not routinely administered. No patient had a fungal infection of the upper GI tract--a finding attributed to the prophylactic use of nystatin in all patients. Opportunistic viral infections were identified histologically in six patients, including two patients with actively bleeding duodenal ulcers. The possibility of opportunistic viral infections in this immunosuppressed group required aggressive diagnostic techniques, including endoscopy and biopsy, which can be safely performed after cardiac transplantation.

Adult↗
PubMed1988

Influence of age on the pharmacokinetics of butorphanol.

Butorphanol kinetics were studied in 8 young (23-34 years of age) and 9 elderly (65-79 years of age) healthy male subjects following a single, intravenous 2-mg dose of butorphanol tartrate. Plasma and blood concentrations collected over 24 h were analyzed by a second antibody radioimmunoassay for unchanged drug. Systemic blood clearance (21.29 +/- 7.18 ml/min/kg), apparent steady-state volume of distribution (9.02 +/- 2.40 liters/kg), distribution half-life (7.67 +/- 4.66 min), and the blood/plasma concentration ratio (1.21 +/- 0.36) in the elderly did not differ from those in the younger subjects. However, the terminal elimination half-life was significantly prolonged in the elderly (5.51 +/- 2.49 versus 3.67 +/- 0.52 h, p less than 0.05). Positive correlations between age and terminal elimination half-life and volume of distribution were noted. Our data suggest that young and old subjects attain similar plasma concentrations after single doses; however, longer dosing intervals may be necessary for multiple dosing in the elderly. The appropriate dosing interval for butorphanol needs to be assessed in elderly patients.

Adult↗
PubMed1987

Muscarinic receptors and amylase secretion of rat pancreatic acini during cerulein-induced acute pancreatitis.

This study examines the effects of cerulein-induced acute pancreatitis on the secretory response of rat pancreatic acini to carbamylcholine and concentration of acinar muscarinic receptors. Rats were injected subcutaneously every 8 hr with cerulein, 12 micrograms/kg, for two days. They were sacrificed 2 and 4 hr after the first injection, 4 hr after the second and third, and 8 hr after the sixth. By 2 hr after the first injection, carbamylcholine showed decreased potency for stimulating amylase release; decreased potency becomes maximal after the second injection. Four hours after the first injection, carbamylcholine also showed decreased efficacy for causing maximal amylase release. In the course of development of pancreatitis, progressive reductions in muscarinic receptor concentrations were evident from 4 hr after the second injection. Following the complete treatment (8 hr after the sixth injection), no alteration could be observed in the affinity or proportions of each agonist class of muscarinic receptors. These studies indicate that the pancreatic acinar cells still remain functional after acute cerulein-induced pancreatitis, although significant reductions in potency and efficacy of carbamylcholine to cause amylase release and reduced muscarinic receptor concentration occur.

Acute Disease↗
PubMed1987

Malignant hyperthermia: a dilemma for the cardiac surgeon.

Malignant hyperthermia is an inherited disease of skeletal muscle characterized by acute elevations of body temperature. The hyperthermic crisis is triggered by a variety of drugs and by volatile anesthetics or it may occur in response to stress. In this report the authors describe the case of a patient with malignant hyperthermia who underwent emergency aortocoronary bypass surgery for unstable angina. They outline the anesthetic and surgical management for individuals susceptible to hyperthermic crises who require open-heart surgery.

Aged↗
PubMed1987

Infectivity and reactogenicity of reassortant cold-adapted influenza A/Korea/1/82 vaccines obtained from the USA and USSR.

The safety and immunogenicity of two live influenza A virus vaccine strains, the CR 59 and 17/25/1 cold-adapted (ca) reassortants, were evaluated in 170 healthy young adult volunteers. The vaccines were produced by recombining A/Korea/1/82 (H3N2) wild-type virus with either A/Ann Arbor/6/60 (H2N2) or A/Leningrad/134/17/57 (H2N2) ca donors of attenuation. Both vaccines were well tolerated in volunteers. The 17/25/1 strain, prepared from A/Leningrad, infected at least 70% of seronegative volunteers after the first dose and 84% after the second; the CR 59 strain infected 62% and 72% of volunteers after first and second doses, respectively. Among the vaccinees who were initially seropositive, 17/25/1 infected 66% after one dose and 85% after two, while CR 59 infected 62% and 71%, respectively. Despite differences in temperature sensitivity, genetic composition, and serological reactivity to monoclonal antibodies, both vaccines behaved almost identically in animal models and man. We conclude that both donors of attenuation may be of great potential value.

Adolescent↗
PubMed1987

Pancreatic and intestinal growth-promoting effect of truncal vagotomy in the rat.

The effect of chronic subdiaphragmatic truncal vagotomy was investigated on body weight gain, food intake pattern, and also on intestinal and pancreatic growth, in adult rats. Two sham-operated groups, the one fed ad libitum, the other pair-fed with the vagotomized rats, served as controls. Body weight of vagotomized rats decreased in the first 5 postoperative days, due to hypophagia. Then, body weight increased as food intake reached the presurgery level. The rats were killed after 34 days of vagotomy. A moderate pancreatic and intestinal hypertrophy was observed in the vagotomized rats, while the tissue weight of and the DNA and protein contents in the colon and the oxyntic and antral areas of the stomach did not change compared to controls. The mechanism of the intestinal and pancreatic hypertrophy is unknown; several humoral and nervous factors may be involved in it.

Animals↗
PubMed1986

Proteases of enhanced stability: characterization of a thermostable variant of subtilisin.

A procedure has been developed for the isolation and identification of mutants in the bacterial serine protease subtilisin that exhibit enhanced thermal stability. The cloned subtilisin BPN' gene from Bacillus amyloliquefaciens was treated with bisulfite, a chemical mutagen that deaminates cytosine to uracil in single-stranded DNA. Strains containing the cloned, mutagenized subtilisin gene which produced subtilisin with enhanced thermal stability were selected by a simple plate assay procedure which screens for esterase activity on nitrocellulose filters after preincubation at elevated temperatures. One thermostable subtilisin variant, designated 7150, has been fully characterized and found to differ from wild-type subtilisin by a single substitution of Ser for Asn at position 218. The 7150 enzyme was found to undergo thermal inactivation at one-fourth the rate of the wild-type enzyme when incubated at elevated temperatures. Moreover, the mid-point in the thermally induced transition from the folded to unfolded state was found to be 2.4-3.9 degrees C higher for 7150 as determined by differential scanning calorimetry under a variety of conditions. The refined, 1.8-A crystal structures of the wild-type and 7150 subtilisin have been compared in detail, leading to the conclusion that slight improvements in hydrogen bond parameters in the vicinity of position 218 result in the enhanced thermal stability of 7150.

Amino Acid Sequence↗
PubMed1986

Prospective payment: systemic effects on the provision of community care for the elderly.

The financial incentives of Medicare's Prospective Payment System are encouraging hospitals to discharge patients sooner and at a lower functional status. This discussion analyzes the possible impact of the subacute patient on the community system of care. Three broad areas of potential impact are examined: the systemic changes in the community system of care stimulated by vertical integration and the influx of proprietaries into community service delivery; structural changes which may be experienced by community service agencies in meeting the demands of increased volume and increased acuity; the impact on the family and the informal system of care delivery as it responds to the increased demands of caring for the subacute patient.

Aged↗
PubMed1985

A double-blind trial of hyperbaric oxygen in the treatment of multiple sclerosis.

A randomized double-blind trial of hyperbaric oxygen (2 atmospheres absolute for 20 sessions of 90 minutes, over a period of one month) demonstrated no advantage over a placebo gas mixture in the treatment of multiple sclerosis. Of 41 patients completing the trial, 21 had been treated with oxygen, eight of whom reported improvement (two confirmed objectively). Of 20 patients in the placebo group, seven claimed improvement (four confirmed objectively). Even when patients with mild disease were considered separately, or when functional systems were assessed individually, no benefit could be shown to result from hyperbaric oxygen therapy.

Adult↗
PubMed1985

Does the underprivileged area index work?

The underprivileged area index was developed by Jarman to identify areas with the greatest need for general practitioner services and where general practitioners were under the greatest pressure. We found that in wards that scored the worst on the underprivileged area index the doctor:patient ratios were the highest. We suggest that the index needs to be used with other indicators to identify variations in need in small areas.

Humans↗
PubMed1985

Macrophage Fc gamma 2b receptor expression and receptor-mediated phospholipase activity: regulation by endogenous eicosanoids.

The expression of Fc gamma 2b receptors and receptor-mediated arachidonic acid metabolism by murine peritoneal macrophages was examined in vitro. The expression of Fc gamma 2b receptors was found to increase progressively with time in culture and this increase was dependent on protein synthesis and glycosylation. The increase in Fc gamma 2b receptor expression was inhibited by hydrocortisone and by BW755C, an inhibitor of both the lipoxygenase and cyclo-oxygenase pathways of arachidonic acid metabolism. Inhibition by BW755C was found to be reversed in the presence of exogenous leukotriene D4. In contrast, selective inhibition of the cyclo-oxygenase pathway by indomethacin enhanced the increase in receptor expression. This enhancement was only partially reversed by exogenous prostaglandin (PG)E2. Interaction of the Fc gamma 2b receptor with ligand in the form of erythrocytes specifically sensitized with IgG2b resulted in the release and subsequent metabolism of arachidonic acid. PGE2 was found to be the principal product. Occupation of the Fc gamma 2a receptor did not result in arachidonic acid release. Down regulation of Fc gamma 2b receptor expression produced a commensurate reduction in receptor-mediated phospholipase activity measured by arachidonic acid release. Macrophages cultured for 24 h in the presence of fetal calf serum without additional stimuli produced substantial amounts of eicosanoids. PGI2 was the principal product. Taken together these data demonstrate a potential feedback regulation of receptor-triggered arachidonic acid metabolism by eicosanoids acting at the level of Fc gamma 2b receptor expression.

Animals↗
PubMed1985

Muscle and plasma amino acids during semi-starvation in normal subjects: hypocaloric glucose vs. amino acid infusions.

Normal subjects were fed hypocaloric amounts of amino acids or glucose for 3 days to separate the effects of these nutrients from those of trauma on muscle and plasma amino acids. Intracellular and plasma levels of Val, Leu and Ile were increased in both groups but were increased to a greater extent when amino acids were infused. Intracellular free glutamine concentration in muscle tissue was not significantly altered. Some of the trauma induced changes in amino acids can be replicated by maintaining normal subjects on hypocaloric amino acids; the decrease in glutamine concentration seen with trauma is not a function of hypocaloric nutrition.

Journal Article↗
PubMed1985

An operational model of pharmacological agonism: the effect of E/[A] curve shape on agonist dissociation constant estimation.

An operational model of pharmacological agonism has been analysed to predict the behaviour of rectangular hyperbolic and non-hyperbolic agonist-concentration effect, E/[A], curves with variation in receptor concentration, [Ro]. Irreversible antagonism is predicted to cause E/[A] curve gradient changes in non-hyperbolic cases but not in hyperbolic cases; in both cases estimation of agonist dissociation constants (KAS) is theoretically valid. 5-Hydroxytryptamine (5-HT) produced "steep' E/[A] curves in contracting the rabbit isolated aorta preparation. Irreversible antagonism by phenoxybenzamine (Pbz) produced a flattened E/[A] curve, consistent with theoretical predictions. Fitting 5-HT E/[A] curves in the presence and absence of Pbz to the model provided an estimate of KA for 5-HT which was not significantly different from the estimate obtained using Furchgott's null method. The operational model of agonism appears to account qualitatively and quantitatively for the effects of [Ro] changes on hyperbolic and non-hyperbolic E/[A] curves. Under conditions where irreversible antagonism may be used to estimate KAS, fitting the operational model directly to E/[A] data represents a valid, economical and analytically simple alternative to the conventional null method.

Animals↗
PubMed1985

Multivariate analysis of glycosylated haemoglobin in insulin-treated diabetics.

Glycosylated haemoglobin (HbA1), as an assessment of overall control, was estimated in 858 insulin-treated diabetics attending for changeover to U100 insulin in North East Wales. Details of age, sex, duration of diabetes, insulin regimen and monitoring method were recorded. Multivariate analysis revealed lower HbA1 in patients receiving twice-daily (mean 11.01) as compared with once-daily insulin (11.42, P = 0.011), but no difference was found between urine and blood glucose testers when other variables were taken into consideration. HbA1 was lower in men (mean 10.94) compared with women (mean 11.39, P = 0.004) and there was a positive correlation of HbA1 in men with age (P = 0.046) and in women with duration of disease (P = 0.005).

Age Factors↗