Control of Ca2+ influx in human neutrophils by inositol 1,4,5-trisphosphate (IP3) binding: differential effects of micro-injected IP3 receptor antagonists.

Neutrophils signal Ca2+ changes in response to occupancy of G-protein-linked receptors such as the formylated peptide receptor. This Ca2+ signal is composed of two parts, inositol 1,4,5-trisphosphate (IP3)-triggered release of Ca2+ from an intracellular store and Ca2+ influx. In order to probe the relationship between these events, cytosolic free Ca2+ changes in neutrophils were monitored after micro-injection of agents which inhibit IP3 binding. Micro-injection of heparin into neutrophils totally inhibited both formylmethionyl-leucylphenylalanine-induced Ca2+ release and the subsequent Ca2+ influx. This effect was not due to prior depletion of Ca2+ stores. Furthermore, micro-injection with anti-IP3-receptor antibody also inhibited Ca2+ release. However, anti-IP3-receptor antibody and another high-molecular-mass IP3-binding antagonist, heparin-albumin conjugate, failed to inhibit the accompanying Ca2+ influx. It was concluded that two IP3-binding sites exist in neutrophils: one accessible by both heparin and the high-molecular-mass inhibitors of IP3 binding and responsible for Ca2+ release, and another inaccessible to high-molecular-mass molecules and responsible for Ca2+ influx.

Long-term follow-up of the treatment of essential hypertension with a high-fibre, low-fat and low-sodium dietary regimen.

Thirty-two patients who were being treated with drugs for essential hypertension were started on a dietary regimen comprising high-fibre, low-fat and low-sodium composition. The results are reported of 19 patients who attended after 3 months and for a long-term mean follow-up period of 3.9 years. A significant reduction in systolic (P less than 0.01) and diastolic blood pressure (P less than 0.001) was observed at 3 months and again after 3.9 years (P less than 0.05 and less than 0.001 respectively). This was accompanied by significant weight loss at 3.9 years (P less than 0.05), although the loss was not as great as that at 3 months of study. The number of anti-hypertensive tablets taken by the group was significantly reduced both at 3 months by 60 per cent (P less than 0.01) and after 3.9 years by 49 per cent (P less than 0.01). No changes were observed in mean levels of total serum cholesterol and triglyceride levels although the significant rise in mean HDL-cholesterol levels observed at 3 months (P less than 0.01) was maintained in the long term (P less than 0.05). Analysis of two 24-h dietary histories on non-consecutive days after 3.9 years demonstrated close compliance with the intended regimen, particularly in intakes of sodium, fibre and carbohydrate. However, mean fat intake was 8 per cent above that of the intended dietary regimen. We conclude that the hypotensive response, accompanied by reduction in weight and antihypertensive drug therapy, and improvement in cardiovascular risk, may be maintained in the long term on the modified dietary regimen.

Chiasmal compression from metastatic cancer to the pituitary gland.

A case of chiasmal compression and panhypopituitarism from carcinoma of the breast metastatic to the pituitary gland is presented. A review of the subject of metastatic disease of the pituitary emphasizes the paucity of clinical involvement in most cases. Posterior pituitary insufficiency is the most common manifestation, with anterior pituitary involvement being much rarer, and chiasmal compression the least common.

Aneurysm of the azygos artery.

A saccular aneurysm of the azygos artery is reported. The relationship between (a) this aneurysm and the primitive vessel from which it arises and (b) the aneurysms which are frequently seen involving persistent carotid-basilar anastomoses is described.