Cardiac allograft rejection and enhancement in natural recombinant rat strains.

Cardiac allografts were carried out using rat strain combinations with recombinant haplotypes. Rejection times were determined in unsensitized recipients, recipients that had been immunized to produce hyperacute or accelerated rejection, and recipients that had been i.v.

Effect of magnesium deficiency on rat bone and kidney sensitivity to parathyroid hormone.

A series of six experiments was conducted to investigate the effects of Mg deficiency in the young rat on parathyroid hormone (PTH) activity and on response to parathyroid extract (PTE) and to endogenously produced PTH stimulated by dietary Ca deficiency. Major criteria employed were 45Ca release from pre-labeled bone and urinary excretion of cAMP. Mg deficiency was accompanied by lowered 45Ca mobilization and urinary cAMP excretion, indicating either a depression in PTH secretion or tissue insensitivity to it.

Goodpasture's syndrome treated with plasmapheresis. Report of a case.

A 55-year old man had pulmonary hemorrhage and renal insufficiency. Direct immunofluorescence of a renal biopsy specimen disclosed prominent linear deposition of IgA along glomerular capillary walls. The patient underwent clinical remission following plasma exchange and immunosuppressive therapy.

Ventricular fibrillation in a patient with unsuspected mitral valve prolapse and a prolonged Q-T interval.

Mitral valve prolapse is a common cardiac abnormality associated with arrhythmias and sudden death. In most instances it can be diagnosed on the basis of physical findings. Those patients who are symptomatic or who display electrocardiographic abnormalities appear to be most susceptible to arrhythmias and, therefore, may be at increased risk for anaesthesia.

A case-control study of hair dye use and breast cancer.

A case-control study of the relationship between hair dye use and breast cancer included 129 breast cancer patients and 193 control women drawn from the records of a multiphasic screening clinic. Information was obtained by telephone interview on a number of risk factors for breast cancer and on variables pertaining to hair dye use: chronologic time, duration, frequency, type, and color. From this, quantitative measures of cumulative hair dye use at various intervals prior to breast cancer (or an equivalent for controls) were obtained.

The effect of anticomplementary cobra venom factor on hyperacute rat cardiac allograft rejection.

Cobra venom factor was used as a probe to evaluate the effect of depression of recipient hemolytic C3 activity on the sequential morphologic features of hyperacute cardiac allograft rejection in the rat. A series of ACI cardiac allografts transplanted to Lewis recipients presensitized &with ACI skin grafts was studied at arbitrary time periods over the initial 24 hours posttransplantation. The usual morphologic features of hyperacute rejection in this model, platelet aggregation, intravascular fibrin, endothelial destruction, neutrophil infiltration, and myocardial necrosis, were not observed in all allografts when recipient hemolytic C3 activity was virtually undetectable at the time of transplantation.

Studies on the role of nickel in the ruminant.

Lambs were fed 6 to 7% of metabolic body weight per day of a basal purified diet low in nickel (65 ppb) or the basal diet plus 5 ppm nickel for a 97 day period in an attempt to demonstrate an essential role for nickel in the ovine. Weight gains for the entire period and digestibility of dry matter and of protein at 28 and 56 days were not different between the two groups. At 28 days, but not at 56 days, urinary nitrogen was less and percentage retention of absorbed nitrogen was greater in the supplemented lambs.

Local degradation of luteinizing hormone-releasing hormone (LH-RH) in the rat central nervous system.

Peptidases inactivating luteinizing hormone-releasing hormone (LH-RH) were found to be present in two subcellular fractions prepared from the following areas of the central nervous system of male and female rats: thalamus, hypothalamus, cortex and cerebellum. LH-RH immunoreactivity was also detected in these fractions after peptidase activity had been removed by heat denaturation. These findings support the concept that LH-RH may have a role in modulating neuronal activity within the central nervous system (CNS).

Hyperacute rejection of cardiac allografts in a rat strain with a hereditary platelet function defect.

Graft hypoperfusion secondary to widespread vascular occlusion by recipient-derived platelet aggregates may be a major determinant of hyperacute cardiac allograft rejection in the rat. Since a hereditary platelet aggregation defect, attributed to decreased platelet levels of serotonin and adenine nucleotides and a depressed release reaction, has been described in the fawn-hooded rat strain, the effects of this intrinsic platelet function defect on the time course and morphologic features of hyperacute rejection have been evaluated. A series of nine heterotopic ACI cardiac allografts in fawn-hooded recipients actively immunized with ACI skin grafts were studied.

Influence of dietary copper on lead toxicity in the young male rat.

An investigation of the influence of dietary copper (1, 5, 20 ppm) on toxicity of dietary lead (0 and 200 ppm) in the young male rat in a 4-week period indicated that as dietary copper increase so did the severity of lead toxicity. Evidence included increased lead concentration in kidney and a two- to threefold increase in the excretion of urinary delta-aminolevulinic acid. Liver copper concentration was also found to increase in rats receiving lead at the two lower copper levels.

Influence of dietary selenium on lead toxicity in the rat.

An investigation of the influence of dietary selenium (0.015, 0.05, 0.

Influence of dietary zinc on lead toxicity in the rat.

An investigation of the influence of dietary zinc (8, 35, 200 ppm) on the toxicity of dietary lead (0, 50, 200 ppm) in the young male rat in a seven week period indicated that as dietary zinc increased, the severity of lead toxicity decreased. Evidence included decreased lead concentration in blood, liver, kidneys, and tibias; decreased excretion of urinary delta-aminolevulinic acid; decreased accumulation of free erythrocyte porphyrins; decreased inhibition of kidney delta-aminolevulinic acid dehydrase activity; and a decrease in apparent lead absorption. Infected zinc did not afford protection against lead toxicity.

Nonessential role of neutrophils as mediators of hyperacute cardiac allograft rejection in the rat.

The presence of neutrophils within the graft has been widely emphasized as a characteristic feature of hyperacute rejection, and analogies have been drawn to the Arthus reaction, in which neutrophils are essential mediators of tissue damage. To evaluate the role of neutrophils as mediators of graft destruction in hyperacute rejection, we studied a series of 16 heterotopic ACT strain rat cardiac allografts in skin-presenitized Lewis strain recipients, all of which recieved prior treatment with cyclophosphamide and methotrexate or heterologous rabbit antirat polymorphonuclear globulin. Fourteen recipients showed significant depression in levels of circulating neutrophils prior to transplant, and neutrophils were not detected in 13 allogrates at the time of functional rejection.

Influence of dietary Ca, Mg, and P on cyclic-AMP excretion and kidney calcification in the rat.

A series of five experiments was conducted with young male albino rats to investigate effects of various levels of dietary Ca, P and Mg on urinary cAMP excretion and kidney calcification. Urinary cAMP excretion was shown to be directly correlated with injected parathyroid (PT) hormone dose level and to be inversely associated with dietary Ca intake. Thus, cAMP excretion may be presumed to reflect PT activity in the young rat.

A controlled sequential morphologic study of hyperacute cardiac allograft rejection in the rat.

A series of heterotopic cardiac allografts from ACI strain rat donors to ACI skin-presensitized Lewis strain recipients was examined by light and electron microscopy at intervals from 1 minute to 24 hours for a sequential morphologic study of hyperacute rejection. Syngeneic Lewis hearts grafts in ACI skin-presensitized Lewis recipients provided controls. Extensive platelet aggregation throughout the vasculature of the allografts in the presence of a largely intact endothelium was the initial morphologic event, which was present by 1 minute posttransplant and absent in all syngeneic controls.

A theoretical method for the determination of amino acid availabilty utilizing 14C labeled protein sources.

A theoretical method is described whereby the availabilities of amino acids from test proteins are determined relative to the availabilities of amino acids from egg albumen. The method requires that both the test protein and the egg albumen be 14C labeled. The relative availabilities of the amino acids are determined from the change in specific activities of the dietary amino acids and those recovered in the feces.