Proteins in a nonvenomous defensive secretion: biosynthetic significance.

In common with many arthropods, the true bug, Leptoglossus phyllopus, when disturbed, emits a two-phase secretion that consists of an organic phase and an aqueous phase. The organic phase is a mixture of highly reactive low-molecular-weight compounds, analogous to those produced by other arthropods, and is deterrent to many kinds of predators. The aqueous phase, heretofore ignored in most analyses of arthropod defensive secretions, contains proteins.

Effect of adriamycin on the reproductive integrity of cultured leukemia L1210 and P388 cells.

Proliferating cultured P388 cells exhibited a greater degree of sensitivity to adriamycin than did proliferating cultured L1210 cells, although both leukemia cell populations had approximately the same doubling time. The rate of reduction in viability when cultured L1210 cell populations were exposed to adriamycin (0.0625-2.

DNA synthesis and depletion of prolactin in the pituitary gland of the male rat.

Haloperidol, bromocriptine and diethylstilboestrol dipropionate were given in various régimes to male rats to determine their effects on pituitary DNA synthesis, prolactin secretion and growth hormone secretion. Haloperidol increased serum prolactin but did not stimulate pituitary DNA synthesis or reduce pituitary prolactin concentrations. Haloperidol potentiated the effects of oestrogen on serum prolactin and on pituitary DNA synthesis; pituitary prolactin concentrations were greatly reduced, and growth hormone secretion was slightly inhibited.

Onset of oestrogen-induced prolactin secretion and DNA synthesis by the rat pituitary gland.

The times of onset of oestrogen-induced prolactin secretion and DNA synthesis were studied in the pituitary gland of the male rat. At intervals from 3 to 96 h after injection of 10 mg diethylstilboestrol dipropionate, serum and pituitary prolactin concentrations were measured by radioimmunoassay and pituitary DNA synthesis by incorporation of [3H]-thymidine in vitro. Serum prolactin was raised significantly from 6 h onwards and DNA synthesis was increased from 30 h onwards.

Kinetics of reduction in viability of cultured leukemia L1210 cells exposed to purine analogs.

Rates of reduction in viability and degree of cell killing were relatively independent of concentrations when replicating cultured L1210 cells were exposed to increasing concentrations of 6-thioguanine, 6-methylthiopurine ribonucleoside, 9-beta-D-arabinofuranosyl-9H-purine-6-thiol, or 9-ethyl-6-thiopurine. The relative lack of dependence of cell killing rate on cytotoxic concentrations suggest (a) that these agents may be only effective aganinst proliferating cells, and (b) that only limited therapeutic advantage can be gainged by increasing their concentration beyond a minimum effective level. In contrast, the rate and degree of cell killing were dependent upon concentrations when cells were exposed to increasing amounts of 4-aminopyrrolo(2,3-d)pyrimidine-beta-D-ribofuranoside or to 2-fluoroadenosine, indicating that these analogs are not cell-cycle-stage-specific and that nonreplicating cell populations may be sensitive to them.

Ambiguity of the thymidine index.

The observed thymidine indices of seven experimental tumor lines are compared as a function of duration of emulsion exposure. The effects of dose level of tritiated thymidine and background threshold are also evaluated. The results indicate that an arbitrary high background threshold discriminates against "lightly" labeled cells at short periods of exposure but that the chosen threshold becomes less critical with longer exposure.

Medullary carcinoma of the thyroid, multiple phaeochromocytomas, mucosal neuromas, marfanoid habitus and other abnormalities (Sipple's syndrome).

A case of Sipple's syndrome is reported, in which the full phenotype was expressed. The patient had the typical marfanoid habitus, with thickened lips and alae nasi, neuromas on lips and tongue, medullary carcinoma of the thyroid gland, phaeochromocytomas, and medullated corneal nerve fibres. The plasma calcitonin level was initially elevated, rose on calcium infusion before thyroidectomy, and was undetectably after thyroidectomy.

Wildlife rabies in Europe and the British situation.

The red fox is considered to be the main reservoir of the present European rabies epizootic which began in Poland in 1939-40. Its usual rate of spread is 20 to 60 km a year. Mortality among rabies-infected fox populations is estimated variously to be 20 to 60%.

The effect of multiphasic biochemical screening on the diagnosis of primary hyperparathyroidism.

Experience of primary hyperparathyroidism (PHPT) at the Royal Brisbane Hospital was reviewed to determine the effect of multiphasic biochemical screening, introduced during 1970, on the rate of diagnosis of this disease. In the period 1959-1970, there were 28 proved cases and, in the period 1971-1974, 41 cases, an increase from 2.5 to 11.

Estimation of tumor cell kill from Gompertz growth curves.

The Gompertz function has been found to mathematically describe several types of biologic growth, including the growth of transplantable animal tumors. If it is assumed that treatment (chemotherapy, surgery, x-irradiation) of tumors causes cell death in a relatively short interval and that the surviving cells begin to repopulate immediately, producing tumor growth according to the Gompertz function before treatment, then the displacement in time between the two growth curves may be quantitatively related to tumor cell kill. This theory is developed and compared to bioassay values.

Urinary excretion of cyclic AMP in primary hyperparathyroidism.

Urinary adenosine 3' 5' - cyclic monophosphate (cyclic AMP) was assessed by a competitive protein binding method in 19 patients with primary hyperparathyroidism (PHPT) and in 15 control subjects. The mean value of 6.6 +/- S.

Urinary cyclic AMP in diagnosis and management of hypercalcaemia: studies of patients without primary hyperparathyroidism.

Urinary adenosine -3' ,5' - cyclic monophosphate was measured in 14 patients with hypercalcaemia not caused by primary hyperparathyroidism. Increased levels were found in patients with malignant disease without bone metastases and believed to be examples of paraendocrine syndrome. Decreased levels were found in patients with metastatic carcinoma involving bone, and in patients with multiple myeloma, lymphoma and immobilisation after fracture.