Muramyl peptides and serotonin interact at specific binding sites on macrophages and enhance superoxide release

Serotonin at low micromolar concentrations inhibited binding of two [125I]-labeled muramyl peptides to resident mouse peritoneal cells and to a macrophage-derived cell line, PU5-1.8-F7. Binding of [3H]serotonin was inhibited in parallel fashion. Overnight incubation with serotonin or muramyl peptide enhanced the release of superoxide by both types of cells when later stimulated with phorbol myristate acetate. Serotonin antagonists decreased binding of muramyl peptide and serotonin and diminished the subsequent enhancement of superoxide release. A cell line variant lacking detectable binding sites for muramyl peptide was far less responsive (superoxide release) than the parent line, to either drug. The data are consistent with sharing of a common set of receptors on the macrophage by muramyl peptide and serotonin and with involvement of these receptors in enhancing superoxide release.

Scanning electron microscopic observations of the oocyst, sporoblast and sporozoite of Plasmodium yoelii yoelii

Scanning electron microscopy was used to study the surface characteristics of the oocyst, sporoblast and sporozoite of Plasmodium yoelii yoelii. Observations were made of the sporogonic stages of 6-12 day infections of the malaria parasite in Anopheles stephensi. Oocyst and sporoblast development were not synchronous. The surface of the undifferentiated (early stage) oocyst appeared smooth, whereas that of differentiated (late stage) oocysts were rough or wrinkled. The wall of the differentiated oocysts showed numerous micropores at higher magnification (x15,000-20,000) the biological significance of which is not known. Small, bud-like satellite bodies were seen attached to some oocysts. Various forms of different stages of the sporoblast were described. Sporozoite budding took place on the surface of the sporoblast body. The sporozoite was elongate, curved and with a blunt anterior end.

In vivo evidence for prostaglandin inhibitory activity in New Zealand green-lipped mussel extract

Prostaglandin synthetase inhibitors (eg, aspirin, indomethacin and naproxen) interfere with ovulation and prolong the gestation period in the rat. These properties could provide a novel test bed for the assessment of agents with prostaglandin biosynthesis inhibitory activity. Rats were fed green-lipped mussel extract and the effects on conception and the subsequent gestation period were determined. Parturition was delayed and fetal development was retarded in the Seatone-fed animals. The observations were consistent with the known effects of nonsteroidal anti-inflammatory drugs, suggesting that Seatone does contain pharmacologically active material inhibiting prostaglandin biosynthesis.

Effects of compliance alteration on healing of a porous dacron prosthesis in the thoracic aorta of the dog

In our study, the results reveal that a marked reduction in the compliance of an external-velour, weft-knit Dacron prosthesis did not impair healing of either the graft wall or of the anastomoses when these grafts were implanted in the upper part of the descending thoracic aorta of the dog for 56 days. These observations are clinically relevant, since they are important to the design of noncrimped fabric prostheses which are resistant to kink and compression when used for axillofemoral, femoropopliteal and femorotibial bypass. However, experimental studies of the influence of compliance disparity should be extended to such grafts implanted for several years.

On a new gap phenomenon in riemannian geometry

This note announces some theorems that show that the flat metric of euclidean space has no nearby nonflat complete metric with the property that its curvature keeps a sign and is "uniformly small" in a sense made precise here.

The gene frequency of serum albumin variants in Chinese and the electrophoretic characterization of several serum albumin variants

By screening a Chinese population of 1025 unrelated persons in Beijing, three serum albumin variants were discovered, and the gene frequency of serum albumin variants of Chinese is estimated as 0.0015. These albumin variants can be distinguished electrophoretically from each other, and were named tentatively as albumin Hanzhong, albumin Changzhi and albumin LXX respectively. A polyacrylamide gel electrophoresis procedure has been developed to characterize albumin variants by determining the relative mobilities (Rm) of albumin variants in a tris-succinate buffer system.

Valproic acid therapy in childhood epilepsy

Valproic acid, used alone or in combination with other anticonvulsants in 100 children with epilepsy, improved seizure control in all age groups. Mean improvement in seizure control was 82%. Petit mal seizures responded best, but other types of seizures, even with associated mental and physical handicaps, also responded well. A substantial improvement in alertness and behavior often occurred. Leukopenia (27%) and an elevated SGOT value (44%) were frequent but transient. Other side effects included alopecia (1), gastrointestinal distress with vomiting (7), pancreatitis (1), thrombocytopenia (1), edema (2), and coma (2). Three severely retarded children with frequent seizures died while receiving valproic acid, but it is not clear that death was caused by valproic acid. Children must be monitored carefully for potential toxic effects, and drug interactions with other anticonvulsants may cause problems in treatment.