Concentration-dependent modulation of basic fibroblast growth factor action on multiplication and locomotion of human teratocarcinoma cells.

A human teratoma cell line (Tera 2) was grown in serum-free medium, and the population multiplication was stimulated by the addition of 1-10 ng basic fibroblast growth factor (bFGF)/ml. The bFGF-effect was abrogated by the addition of protamine sulphate. When high concentrations of bFGF were added, a preferential effect on cell locomotion was observed. 100 ng bFGF/ml stimulated cell movement but only exerted a marginal effect on cell multiplication. These observed exogenous requirements for multiplication and locomotion were complemented by the expression of bFGF receptors. Scatchard analysis of binding data suggests the existence of a high-affinity and a low-affinity class of receptors.     

Phenylalanine Absorption and Metabolism in Parkinsonian Patients

Oral and intravenous L-phenylalanine loading tests were performed in 13 Parkinsonian patients and in 12 control subjects matched for age and weight. The results showed a normal intestinal absorption and a normal elimination from plasma of phenylalanine in the Parkinsonian patients.     

Effects of insulin-like growth factor-binding protein 2 and an IGF-type I receptor-blocking antibody on apoptosis in human teratocarcinoma cells in vitro

Human teratocarcinoma cells (Tera-2) deprived of serum undergo programmed cell death which can be counteracted by simultaneous addition of IGF-I or IGF-II. This protective effect of IGFs was specific in the sense that both addition of IGF-binding protein-2, and blocking of the IGF-type I receptor by a specific antibody, both resulted in an increased apoptotic rate.     

Neuronal storage of histamine in the brain and tele-methylimidazoleacetic acid excretion in portocaval shunted rats

Rats with portocaval anastomosis (PCA), an animal model of hepatic encephalopathy (HE), have very high brain histamine concentrations. Our previous studies based on a biochemical approach indicated histamine accumulation in the neuronal compartment. In this study, immunohistochemical evidence is presented which further supports the amine localization in histaminergic neurons. These neurons become pathological in appearance with cisternae frequently seen along histaminergic fibres in many brain areas, including the hypothalamus, amygdala, substantia nigra and cerebral cortex. Such formations were not observed in sham-operated animals. The neuronal deposition is predominant, and unique for histamine. It serves as a mechanism to counterbalance excessive brain neurotransmitter formation evoked by PCA. However, there are other mechanisms. The data provided here show that there is also a significant increase in histamine catabolism in the shunted rats, as reflected by both the higher brain N-tele-methylhistamine (t-MeHA) concentration and urinary excretion of N-tele-methylimidazoleacetic acid (t-MelmAA), a major brain histamine end product. The stomach, in addition to the brain, is a site of enhanced histamine synthesis in portocavally shunted subjects. After gastrectomy or food deprivation to eliminate the contribution of the stomach, shunted rats excrete significantly more t-MelmAA, implying the role of the CNS. This last finding suggests that under strictly defined conditions, namely in parenterally fed HE patients with abnormal plasma L-histidine, the measurement of urinary t-MelmAA might provide valuable information concerning putative brain histaminergic activity.     

Beneficial effects of angiotensin converting enzyme inhibition on renal function in patients with diabetic nephropathy.

The effects of angiotensin converting enzyme inhibition with captopril were investigated in patients with diabetic nephropathy and hypertension. After nine days'' treatment with captopril glomerular filtration rate was unchanged in 13 patients, whereas renal plasma flow had increased from 265 to 302 ml/min/1.73 m2 body surface area (p less than 0.05) and the filtration fraction had decreased from 14.3 to 12.8% (p less than 0.025). During two years'' treatment with captopril in 14 patients the mean arterial blood pressure had fallen by 5 mm Hg (p less than 0.005) and the deterioration in glomerular filtration rate had decreased from 10.3 to 2.4 ml/min/year (p less than 0.005). There was no correlation between the fall in blood pressure and the reduction in the deterioration of glomerular filtration rate. These findings suggest that the effects of angiotensin converting enzyme inhibition on renal haemodynamics protect renal function. Inhibitors of angiotensin converting enzyme should be considered for lowering blood pressure in patients with diabetic nephropathy.