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Biomedical subjects

J Hunter

Publications and source records attributed to J Hunter.

At least 199 records · Page 11Linked to original sources
PubMed1981

Inhibitors of monocyte responses to chemotaxins are present in human cancerous effusions and react with monoclonal antibodies to the P15(E) structural protein of retroviruses.

Individuals with cancer have previously been shown to have abnormal chemotactic responsiveness. Surgical removal of the tumor often resulted in normalization of monocyte function, which suggests that human neoplasms might inhibit monocyte chemotaxis by release of soluble mediators. We therefore examined the effects of cancerous effusions on monocyte polarization, i.e., the rapid change in monocyte morphology from round to a triangular "motile" configuration in response to chemoattractants. All 17 malignant effusions, representing 15 tumor types, inhibited monocyte polarization induced by the chemoattractant N-formyl-methionyl-leucyl-phenylalanine by 45-89% (mean 55.9 +/- 12.7%, P less than 0.01) in blinded assays. None of 17 benign effusions signigicantly inhibited polarization (0-15%, mean 6.2 +/- 4.2%). Dilutions of cancerous effusions as low as 1:200 produced inhibition that was time, temperature, and dose dependent . Monocyte polarization induced by activated serum or by chemotactic lymphokine was also blocked by cancerous effusions. The inhibitory activity affected the monocyte directly, and did not destroy the chemoattractant or block the polarization of granulocytes to chemotactic factors. High pressure liquid chromatography of five cancerous fluids revealed three peaks of inhibitory activity: greater than or equal to 200,000, 46,000 +/- 13,000, and 21,000 +/- 3,000 daltons. Fractionation of noncancerous effusions revealed only small amounts of the highest molecular weight inhibitory activity. The inhibitory activity in cancerous effusion was heat stable (56 degrees C, 30 min), trypsin sensitive, and could be absorbed by three different monoclonal antibodies reactive to P15(E), a structural component of type C retroviruses. In contrast, six monoclonal antibodies with other specificities had no effect on the inhibitors of polarization. This study demonstrates that human cancerous effusions contain novel proteins that are potent inhibitors of monocyte function and that are recognized by antibodies reactive to the P15(E) component of retroviruses. By producing such factors, tumor cells may subvert monocyte-mediated surveillance.

Adult↗
PubMed1980

Mucocutaneous lymph node syndrome (Kawasaki disease). A report of 2 cases.

Two cases of Kawasaki disease, both with cardiac involvement, are reported in South African children and the diagnostic problems are discussed. In patient 1 an ECG showed the development of an inferior myocardial infarction, and in patient 2 on aneurysm of the left coronary artery was found at postmortem examination.

Child, Preschool↗
PubMed1980

Descending aortic aneurysmectomy without adjuncts to avoid ischemia.

Encouraged by reports on the safety of simple aortic cross-clamping for resection of descending aortic aneurysm, we began utilizing this technique more liberally in 1976. This study was undertaken to examine the results of operation in 36 patients, equally divided into two distinct groups. In Group 1, either extracorporeal circulation or indwelling temporary shunts were employed during the period of aortic occlusion. In Group 2, simple aortic cross-clamping was utilized to manage the lesion. No adjuncts were used to avoid ischemia in the latter group. The only 2 early deaths and two instances of paraplegia occurred in Group 1. In general, there were fewer complications in Group 2, with approximately two-thirds of the patients experiencing an uneventful postoperative course. These differences are considered important since the two groups were similar in respect to the extent and nature of the lesions and other factors contributing to operative risk.

Adolescent↗
PubMed1979

Safety and efficacy of living BCG or BCG cell walls (CW) in the treatment of guinea pig hepatoma.

Guinea pigs with established intradermal tumors and microscopic lymph node metastases were treated by intralesional injection of graded doses of living BCG or BCG CW. The lowest dose of living BCG used produced a significant cure rate and no grossly evident toxicity. An intermediate and the highest dose of living BCG used cured some animals but others lost weight and a significant number died as a result of the treatment. Histologic examination of animals with significant weight loss showed fatty degeneration of the liver, granulomatous hepatitis and histiocytic infiltration of the spleen. None of the doses of BCG CW used was toxic and they were at least as effective as living BCG in intralesional treatment. In some experiments in which treatment was delayed it was found that the extent of disease required to render treatment ineffective was about the same for living BCG and for BCG CW.

Animals↗
PubMed1979

Gestation and inter-birth intervals in the owl monkey (Aotus trivirgatus griseimembra).

A single, timed mating indicated a gestation period of 133 days for Aotus trivirgatus griseimembra. This figure is confirmed by approximate correspondence with minimum inter-birth intervals, results from radioimmunoassay of urinary oestrogens during pregnancy, and general agreement with a logarithmic plot of gestation period against body weight for simian primates. Birth data indicate that owl monkey females in present colonies in captivity breed throughout the year and will, on average, produce 3 infants every 2 years. There is no evidence of a characteristic post-partum oestrus.

Animals↗
PubMed1979

A comparison and an investigation of a potential synergistic effect of labetalol and bethanidine in patients with mild hypertension.

1 The effects of labetalol, bethanidine and combined treatment with both drugs were compared in a within-patient randomized cross-over study in mild essential hypertension. Attention was directed to whether or not labetalol and bethanidine differed in their pattern of effect on arterial BP and whether evidence of synergism was apparent. 2 At the doses used labetalol significantly lowered systolic and diastolic BPs and heart rate lying, sitting, standing and after exercise. The dose of bethanidine used did not affect heart rate significantly while lowering systolic and diastolic BPs only after exercise and less clearly on standing. Combined treatment lowered BPs on standing and after exercise and heart rate after exercise. 3 The type and frequency of side-effects were similar with bethanidine and labetalol but were much less with combined treatment. 4 No evidence of synergism was observed.

Adult↗
PubMed1977

An RNA core in the 30S ribosomal subunit of Escherichia coli and its structural and functional significance.

1. Evidence is presented for the occurrence of a very stable RNA core (S4-RNA) in "native" 16S RNA that is also present in the 30S subunit of Escherichia coli. A model giving the approximate location of this RNA core in the 30S subunit is presented. 2. It is proposed (a) that this S4-RNA acts as a nucleus for the assembly of the 30S subunit, and (b) that a small class of "linkage" proteins, including S4, further facilitate the assembly of the proteins to the RNA, thereby explaining some of the "cooperative" effects that are observed during in vitro assembly. 3. Evidence for the importance of the RNA core in the functioning of the ribosome is discussed.

Bacteria↗
PubMed1977

Effect on pancreatic blood flow and insulin output of infusions of aminophylline, galactose and galactose plus aminophylline into an isolated in situ portion of pancreas.

Effects on pancreatic blood flow and insulin output of infusions of aminophylline, galactose and galactose plus aminophylline were studied on an isolated portion of dog pancreas with only one afferent and one efferent blood vessel remaining. Infusion of aminophylline at 8 mg per minute gave significant increases in pancreatic blood flow and insulin output. Infusion of galactose at 7.2 mg per minute significantly increased insulin output. Galactose (7.2 mg per minute) plus aminophylline (8 mg per minute) also increased both pancreatic blood flow and insulin output. Pancreatic venous plasma glucose levels rose slightly during these infusions. Since the perfusing plasma contained a fasting level of glucose both aminophylling and galactose when infused alone or together were infused in the presence of approximately 1 mg/ml glucose. Pancreatic blood flow and insulin output increased to a lesser extent when aminophylline was infused along with galactose, the when aminophylline was infused alone.

Aminophylline↗
PubMed1976

Incidence of sperm antibodies before and after vasectomy.

Sperm-agglutinating antibodies were present in three (2-6%) of 117 fertile men and in 19 (33-9%) of 56 men who had been vasectomized. Twenty-four of the 56 vasectomized men had been studied before vasectomy; sperm-agglutinating antibodies were present in one (4-3%) compared with eight (33-3%) after vasectomy. No sperm-immobilizing antibodies were detected before vasectomy but were present in 10 (17-9%) of the 56 men after vasectomy.

Antibodies↗
PubMed1976

Age-related changes in localization of injected radiolabelled lymphocytes in the lymph nodes of antigen-stimulated mice.

The localization of i.v. injected syngeneic lymph node cells, radiolabelled with 51Cr or 75Se-L-selenomethionine, was studied in male CBA/H mice aged between 3 and 30 months. The following results were obtained. (1) Localization of cells from young adult donors was greater in the s.c. lymph nodes of old than of young recipients, the main increase being between 15 and 17 months of age. Increases in lymph node weight and DNA-synthesis were also seen at this time; but the rise in cell localization was significant even when calculated per unit of tissue weight. Splenic localization either declined slightly with age or, like the liver, showed no significant change. (2) Local antigenic stimulation by a single injection of sheep erythrocytes into one front footpad, 24 hr before lymph node cell injection, resulted in increased localization in the regional lymph nodes of 3-17 month old, but rarely of 24-30 month old mice. (3) No consistent differences in localization were observed between lymph node cells from 4-month and 25-month old donors. Both age-related and antigen-related increases in cell localization were at least partly attributable to an enhanced rate of entry of lymphocytes from the blood to the lymph nodes. Although the changes underlying the decline in antigen-related localization of cells in old recipients have still to be clarified, it is probable that the defective immune responses of old mice result partly from this decline.

Aging↗
PubMed1974

Changes in cortisol metabolism following rifampicin therapy.

A patient with Addison's disease required increased corticosteroid dosage whilst receiving rifampicin. The pharmacological half-life of cortisol was reduced, but returned to normal when rifampicin was stopped. Cortisolproduction rates in four patients with pulmonary tuberculosis rose during treatment with rifampicin, as did urinary D-glucaric-acid excretion, an index of liver microsomal-enzyme activity. The alteration of the corticosteroid requirement in the patient with Addison's disease and the elevation of the cortisol-production rates were attributed to increased cortisol catabolism following hepatic macrosomal-enzyme induction by rifampicin.

Addison Disease↗