Search PubMed⌕ Search

Biomedical subjects

H Black

Publications and source records attributed to H Black.

At least 55 records · Page 3Linked to original sources
PubMed1985

Lantana poisoning of cattle and sheep in New Zealand.

The investigation of a field case of Lantana camara poisoning in cattle is reported. Toxicity was confirmed by the experimental dosing of two sheep with dried leaf powder at 6 and 12 mg/kg body weight. Marked cholestatic hepatophy and renal tubular disease resulted. This is the first reported case of toxicity due to grazing a Lantana camara variety grown in New Zealand.

Journal Article↗
PubMed1979

Impaired renal tubular potassium secretion in sickle cell disease.

We examined renal tubular function in six patients with sickle cell hemoglobin. All had normal inulin and para-aminohippurate clearances and impaired urinary concentrating and acidifying abilities. After intravenous potassium chloride administration, maximum excretion of potassium (U,V) was significantly lower in sickle cell patients than in control subjects, and the percentage of potassium load excreted in 5 h was markedly reduced. Urinary potassium excretion after sodium sulfate infusion was also markedly reduced in sickle cell patients compared to control subjects. After 40 mg of oral furosemide, U,V was also diminished in sickle cell patients. Plasma aldosterone response to ACTH and intravenous potassium was similar to that of control subjects. Plasma renin activity increased normally after volume contraction. We conclude that sickle cell patients have a defect in their ability to excrete an acute potassium load that cannot be attributed to abnormal renin or aldosterone secretion. Overall potassium homeostasis is maintained by extrarenal mechanisms during acute potassium loading.

Aldosterone↗
PubMed1977

Results and complications of intraaortic balloon pumping in surgical and medical patients.

The intraaortic balloon was attempted for therapy in 94 patients and successfully placed in 86. The balloon catheter could not be passed through the femoral or iliac artery in 12 patients (13 percent) of the group; in 4 of these the balloon was inserted through an aortic arch graft. The medical indications were cardiogenic shock and preinfarction angina. Ten of the 14 patients in the group with shock survived when treated with an aortic balloon without emergency surgery. Indications for balloon pumping in the surgical group included inability to wean the patient from the pump-oxygenator, postoperative shock and prophylactic placement of the balloon for poor ventricular function. Inability to remove a patient from pump-oxygenator support was the most common surgical indication, and 47 percent of patients were long-term survivors. Only 1 of the 17 patients for whom balloon pumping was used prophylactically died. Complications occurred in 17 percent of the entire group of 86 patients although the rate for medical patients with cardiogenic shock was 50 percent. The most common complication was arterial insufficiency requiring removal of the balloon. Four patients had permanent damage to the legs from ischemia, one patient requiring bilateral amputation. The overall incidence of serious arterial obstruction was 10 percent. Other complications included balloon displacement with arterial obstruction and pericardial tamponade from anticoagulant agents resulting in death.

Angina Pectoris↗
PubMed1977

Left ventricular wall resection for aneurysm and akinesia due to coronary artery disease: fifty consecutive patients.

Left ventricular wall resection with or without vein bypass grafting was performed in 50 consecutive patients with aneurysm or an akinetic segment with poor left ventricular hemodynamics. Ejection fraction averaged 29% and left ventricular end-diastolic pressure averaged 20 mm Hg. Associated valve disease was present in 14 patients (28%). Hospital mortality was 22% (11 patients) and late mortality was 20% (10 patients). The lowest mortality (3%, 1 death) was found in patients who had anterior apical resection with associated vein bypass, in whom prophylactic balloon pumping was used when needed for ejection fractions of less than 30%. A high mortality occurred with associated valve replacement (6 deaths, 86%) and posterior aneurysm. Among 39 patients followed for an average of twenty-four months, 34 (87%) improved one class and 18 (46%) improved two classes of the New York Heart Association Functional Classification.

Adult↗
PubMed1976

Suspected Sarcocystis infections of the bovine placenta and foetus.

Protozoan parasites resembling Sarcocystis schizonts were found in the brains of 2 bovine foetuses and the placentas of another 4. As typical of Sarcocystis, the organisms were located mainly within vascular endothelial cells, and frequently the zoites within the schizonts were arranged in a rosette or palisade fashion. Pathological changes noted were placentitis, myocarditis, pulmonary vasculitis and encephalitis. Attempts to demonstrate Toxoplasma by animal inoculation and serology were unsuccessful.

Abortion, Veterinary↗
PubMed1976

A syndrome of acute zinc deficiency during total parenteral alimentation in man.

Changes in the plasma and urine levels of the trace metal zinc have been followed in a series of 37 adult patients totally supported by intravenous alimentation. Copper has also been determined in more recent cases. In such a seriously ill group, although urinary zinc loss may be very high at the height of catabolism, severe plasma depletion does not occur unless there is a subsequent phase of sustained anabolism and weight gain. In four patients plasma zinc fell to very low levels during this phase and three of this group developed a syndrome characterized by diarrhea, mental depression, para-nasal, oral and peri-oral dermatitis, and alopecia. The response to oral or intravenous zinc therapy is striking, except for hair regrowth which is delayed but eventually complete. The syndrome we have recognized in adult man has not been previously described. It resembles however the parakeratosis of zinc deficient swine and it is also very similar to Acrodermatitis enteropathica, a genetically determined disorder of infants very recently linked to zinc deficiency. Zinc is clearly essential to human metabolism and it should be included in all parenteral alimentation regimes particularly during the period of rapid, sustained, weight gain.

Adult↗
PubMed1976

Influence of uremia and hemodialysis on the turnover and metabolic effects of glucagon.

To evaluate the mechanism and role of hyperglucagonemia in the carbohydrate intolerance of uremia, 19 patients with chronic renal failure (12 of whom had undergone chronic hemodialysis for at least 11 mo) and 35 healthy control subjects were studied. Plasma glucagon, glucose, and insulin were measured in the basal state, after glucose ingestion (100 g), after intravenous alanine (0.15 g/kg), and during a 3-h continuous infusion of glucagon (3 ng/kg per min) which in normal subjects, raised plasma glucagon levels into the upper physiological range. Basal concentrations of plasma glucagon, the increment in glucagon after infusion of alanine, and post-glucose glucagon levels were three- to fourfold greater in uremic patients than in controls. The plasma glucagon increments after the infusion of exogenous glucagon were also two- to threefold greater in the uremics. The metabolic clearance rate (MCR) of glucagon in uremics was reduced by 58% as compared to controls. In contrast, the basal systemic delivery rate (BSDR) of glucagon in uremics was not significantly different from controls. Comparison of dialyzed and undialyzed uremics showed no differences with respect to plasma concentrations, MCR, or BSDR of glucagon. However, during the infusion of glucagon, the increments in plasma glucose in undialyzed uremics were three- to fourfold greater than in dialyzed uremics or controls. When the glucagon infusion rate was increased in controls to 6 ng/kg per min to produce increments in plasma glucagon comparable to uremics, the glycemic response remained approximately twofold greater in the undialyzed uremics. The plasma glucose response to glucagon in the uremics showed a direct linear correlation with oral glucose tolerance which was also improved with dialysis. The glucagon infusion resulted in 24% reduction in plasma alanine in uremics but had no effect on alanine levels in controls. It is concluded that (a) hyperglucagonemia in uremia is primarily a result of decreased catabolism rather than hypersecretion of this hormone; (b) sensitivity to the hyperglycemic effect of physiological increments in glucagon is increased in undialyzed uremic patients; and (c) dialysis normalizes the glycemic response to glucagon, possibly accounting thereby for improved glucose tolerance despite persistent hyperglucagonemia. These findings thus provide evidence of decreased hormonal catabolism contributing to a hyperglucagonemic state, and of altered tissue sensitivity contributing to the pathophysiological action of this hormone.

Adolescent↗
PubMed1975

The role of intraaortic balloon counterpulsation in patients undergoing cardiac operations.

Intraaortic balloon counterpulsation (IABC) was used to assist 60 patients undergoing cardiac operations for reasons of acute left ventricular failure (18 patients) or electively for indications in high-risk coronary and valvular heart disease (42 patients). Nine of 18 patients achieved hemodynamic stability when treated for acute perioperative or postoperative cardiogenic shock. Four of these died from problems unassociated with postoperative left ventricular failure and 5 were long-term survivors, indicating a potential salvage of 50%. In 42 high-risk patients, IABC was used electively to control preinfarction angina before operation (21 patients) and prophylactically to prevent postoperative low-output failure in another 21 patients with severe coronary and valvular heart disease. Thirty-nine, or 93%, of these patients survived. There were no deaths in the preinfarction angina group, 1 death in the group with coronary disease and ejection fractions less than 30%, and 2 deaths in those with valvular heart disease and congestive failure. Seven patients developed thrombotic or ischemic complications, but no permanent damage resulted. IABC is an important form of assistance for any patient with preoperative, intraoperative, or postoperative left ventricular failure and adds safety and hemodynamic stability for the high-risk patient with preinfarction angina or poor ventricular function.

Assisted Circulation↗
PubMed1975

Smoking and disease: effect on serum antitrypsin in hospitalized patients.

The mean serum antitrypsin (AT) activity for 1,829 patients hospitalized with medical problems exceeded the mean for a group of blood bank donors by 51%. Analysis of data from individual patients in terms of the general category (there were 16) of their disease and smoking status (smoker, nonsmoker, former smoker) indicated significant differences due to disease status and smoking status. The highest mean AT levels were associated with infectious, respiratory, and neoplastic diseases. Smokers had significantly higher mean levels than nonsmokers, and lung cancer patients had significantly higher mean levels than those with other malignant neoplasms. Among smokers (as a group) mean AT levels. through elevated relative to nonsmokers were not significantly related to duration or intensity of smoking; but former smokers showed a decline (with time following cessation of smoking) in their mean AT level to the mean level for nonsmokers. These findings provide further evidence of the sensitivity of serum antitrypsin activity to environmental influences.

Adult↗