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Biomedical subjects

H Hunt

Publications and source records attributed to H Hunt.

30 records · Page 2Linked to original sources

Observations on 100 patients with continuous intraoperative monitoring of intramyocardial pH. The adverse effects of ventricular fibrillation and reperfusion.

Intramyocardial pH and temperature data recorded in 100 patients undergoing cardiac operations were analyzed to elucidate the effects of ventricular fibrillation and reflow. All patients underwent a single period of aortic clamping. Systemic hypothermia (25 degrees C) and intermittent cold crystalloid K+ cardioplegia were employed for myocardial protection. Baseline myocardial pH was 6.88 +/- 0.03 at a temperature of 36.5 degrees +/- 0.2 degree C. During the period of hypothermic ventricular fibrillation prior to aortic clamping, ventricular fibrillation did not affect myocardial pH in 45 patients (Group 1). In 21 patients (Group 2), it caused a significant drop in intramyocardial pH despite cooling. Group 2 patients had a higher incidence of valvular heart disease and left ventricular hypertrophy. They also exhibited low intramyocardial pH values during the subsequent periods of aortic clamping and reflow, indicating inadequate myocardial protection. During the period of reflow, reperfusion acidosis (pH less than 6.8 at 32 degrees C) was encountered in 39 patients (Group B) as opposed to 37 patients (Group A) whose pH remained well above 6.8 during that period. Group B patients had a higher incidence of valvular heart disease and left ventricular hypertrophy, tended to have more ischemic anterior walls prior to cardiopulmonary bypass, sustained longer periods of aortic clamping, had intramyocardial pH evidence of suboptimal protection during aortic clamping, were affected more adversely by ventricular fibrillation during reflow, and tended to have a higher operative mortality. Thus: Depending on the underlying myocardial disease, the adequacy of protection during aortic clamping, and the conditions of reflow, intramyocardial pH in man can fall significantly during ventricular fibrillation and reflow. The metabolic correlate of injury with reflow is a reperfusion acidosis that can reach as low as pH 5.98. When encountered, reperfusion acidosis can be minimized by prompt defibrillation.

Adult↗

Delayed-onset heparin-induced thrombocytopenia. A potentially malignant syndrome.

Delayed-onset thrombocytopenia developed in 12 patients while they were receiving either prophylactic or therapeutic heparin. Five of the patients had thrombocytopenia alone, and seven had thromboembolic complications which contributed to the death of one patient. These complications included deep venous thrombosis (four patients), pulmonary embolism (three patients), myocardial infarction (one patient), sagittal sinus thrombosis (one patient), and femoral artery occlusion (one patient). The diagnosis of heparin-induced thrombocytopenia was delayed for between one and 13 days after the initial complicating event. All patients had heparin-dependent platelet-aggregating factor in their plasma. The characteristics of the heparin-dependent platelet-aggregating reaction were the same in all patients, but the nadir of thrombocytopenia was lower in patients with delayed-onset heparin-induced thrombocytopenia and complicating thromboembolism. These findings highlight the necessity for early recognition of this syndrome and for the prompt withdrawal of heparin to prevent considerable patient morbidity.

Adult↗

Alcoholism among Aboriginal people.

Much has been spoken and written about alcohol problems in Aboriginal communities, but little has been achieved in dealing with these problems effectively, as is clearly illustrated by the statistics in this article, which summarizes the over-all situation in New South Wales, analyses its historical development, and shows its present catastrophic proportions. An approach, based on 13 years of active and intensive involvement in this particular field, is presented which if properly implemented, could greatly alleviate this pressing problem.

Alcoholics Anonymous↗

Cryogenic preservation of rat polymorphonuclear leukocytes.

Rat polymorphonuclear leukocytes (PMNs) were frozen to --196 degrees C, thawed, and tested for functional viability using a variety of criteria, which included: qualitative and quantitative nitroblue tetrazolium assays, fluorometric membrane integrity assays, chemotactic assays, and bactericidal assay. Using these criteria, the survival of rat PMNs obtained from a glycogen-induced peritoneal wash averaged approximately 70% after thawing. The survival of PMNs obtained from rat peripheral blood was greater than 95%. Maximal survival for cryopreservation of these cells frozen in the presence of 10% dimethyl sulfoxide and 5% hydroxyethyl starch was obtained when the cells were cooled at approximately 10 degrees C/min.

Animals↗

Ward environment in an inpatient drug dependence treatment unit: II. Attempts to improve ward environment.

Ward activity and atmosphere in a Drug Dependence Treatment Unit were found to be poor in a previous study. The results of two attempts to improve ward environment are reported. The arrival of an occupational therapist had a very slight and restricted effect on the level of patients' constructive activity, and produced only one significant change on the Ward Atmosphere Scale; patients perceived an increase in Practicality. There was, however, a consistent improvement in patients' Vigor and Friendliness mood scores following the arrival of the occupational therapist. A pilot project using cigarettes as reinforces for patient constructive activity produced little sustained effect. Possible reasons for the difficulties in managing drug-dependent patients are discussed, and suggestions made for improvement.

Affect↗

Adrenergic factors influencing the mitotic rate in stratified squamous epithelium of the buccal mucosa of the rat.

1. An in vivo stathmokinetic technique was used to determine the immediate effect of various adrenoceptor agonists and antagonists on the mitotic rate in the stratified squamous epithelium of the rat buccal mucosa. 2. The mitotic rate increased significantly in rats treated with propranolol and with practolol, whereas the mitotic rate decreased significantly in rats treated with metaraminol. In animals treated with isoprenaline and phentolamine the mitotic rate did not differ significantly from the control value. 3. The nature of the involvement of adrenergic mechanisms with cell proliferation is still uncertain but both alpha- and beta-adrenergic mechanisms appear to be associated with the control of cell proliferation.

Adrenergic alpha-Agonists↗

Development and characterization of monoclonal antibodies to subgroup J avian leukosis virus.

In an attempt to develop a specific diagnostic test for avian leukosis virus (ALV) subgroup J (ALV-J) strain Hc1, four monoclonal antibodies (MAbs), JE9, G2, 145, and J47, were generated that are specific for ALV-J envelope glycoprotein, gp85. Polymerase chain reaction (PCR) was used to amplify genomic pro-viral DNA of Avian Disease and Oncology Laboratory (ADOL)-Hc1 and ADOL-4817 envelope genes. Both open reading frames encoding glycoproteins gp85 and gp37 were cloned into baculoviruses. Abundant expression of gp85 and gp37 was detected in the recombinant viruses with specific antibody to Hc1 strain of the ALV-J. The expressed proteins were used for immunization of mice to produce hybridoma cell lines secreting MAbs specific to ALV-J envelope protein. A panel of MAbs was generated by fusing NS1 myeloma cells and spleen cells from mice immunized with the recombinant baculoviruses. With the use of an immunofluorescence assay, three MAbs (JE9, G2, 145) reacted with ALV-J but not with subgroups A, B, C, D, or E of ALV. MAb J47 reacted with all exogenous subgroups of ALV including A, B, C, D, and J but not with endogenous subgroup E viruses. Western blot analysis was performed with all four MAbs against recombinant baculovirus and Hc1-infected chicken embryo fibroblast (CEF) lysates. A major band with a molecular weight about 90 kD corresponding to the size of ALV-J envelope was consistently obtained. With these MAbs, we detected the Hc1 antigen in CEFs infected with several ALV-J viruses isolated in the United States and also in tissue sections from chickens infected with Hc1 strain of ALV-J. These MAbs will be useful reagents for the diagnosis of ALV-J infection because they recognize a common antigenic epitope in six isolates tested thus far.

Animals↗

Comparison of specialized and standard enteral formulas in trauma patients.

STUDY OBJECTIVE: To compare selected nutrition and immunologic markers and infection in trauma patients receiving a specialized enteral formula with those receiving standard enteral therapy. DESIGN: Prospective, randomized clinical trial. SETTING: Level 1 trauma center at a county government hospital. PATIENTS: Forty-one consecutive patients with major trauma who required enteral nutrition support. Thirty-seven patients completed the study. Four patients (two in each group) were excluded, as additional operative procedures prevented initiation of enteral feedings within 7 days of injury. INTERVENTIONS: Nineteen patients fed the specialized enteral formula received supplemental arginine, linolenic acid, beta-carotene, and hydrolyzed protein for up to 10 days. Eighteen control patients received standard enteral nutrition. MEASUREMENTS AND MAIN RESULTS: After study entry, patients who received the specialized enteral formula had fewer infections than those receiving standard enteral nutrition (3/19 vs 10/18; p < 0.05). The change in nitrogen balance was significantly better (p < 0.05) from day 1 (-11.8 +/- 1.8 g/day) to day 5 (-5.9 +/- 2.0 g/day) for the group who received the specialized formula compared with the group who received standard enteral nutrition (-7.3 +/- 1.7 g/day to -7.4 +/- 2.8 g/day). Similarly, the change in C-reactive protein serum concentration was significantly better (p < 0.05) from day 1 (18.0 +/- 2.1 mg/dl) to day 5 (11.8 +/- 1.5 mg/dl) in the group who received the specialized formula compared with the group who received standard enteral nutrition (17.6 +/- 1.2 mg/dl to 14.4 +/- 1.7 mg/dl). The CD4:CD8 ratio increased more in the group who received the specialized formula, although this difference did not reach statistical significance. CONCLUSION: Trauma patients who received the specialized enteral formula demonstrated a decreased incidence of infection and increased improvements in nitrogen balance and other indexes of stress. Additional clinical trials demonstrating positive patient outcomes are necessary before these specialized enteral formulas are used as the standard of practice in critically ill patients.

Adolescent↗