The effect of cholinergic drugs on [3H]acetylcholine release from slices of rat hippocampus, striatum and cortex

Slices from rat hippocampus, striatum or cortex were incubated with l mum [3H] choline and following 75 min superfusion with Krebs solution the efflux of radioactivity was measured. The slices were stimulated either electrically (1 Hz) or with 25 mM potassium and the rate constant of the evoked release and the size of the releasable pool were estimated. The spontaneous efflux of radioactivity and the releasable pool but not the rate of evoked release correlated with the reported endogenous ACh content of the 3 areas. Raised potassium released radioactivity at a lower rate but from a larger pool than electrical stimulation from all 3 areas. In all 3 areas atropine alone potentiated while physostigmine, oxotremorine and carbamylcholine decreased the rate of evoked release. This depression was fully antagonized by atropine. The drugs had no effect on the size of the releasable pool. Findings suggest that muscarinic receptors located on cholinergic axons or terminals have a physiological role in the autoregulation of ACh release from these 3 areas.     

Adrenergic receptors and secretory responses of the rat submandibular salivary gland after periodic incisor reduction

While loss-of-function mutations in Gsalpha are invariably associated with the short stature and brachydactyly of Albright hereditary osteodystrophy (AHO), the association with hormone resistance (to parathyroid hormone and thyrotropin) typical of pseudohypoparathyroidism type Ia (PHP-Ia) is much more variable. Observational studies and DNA polymorphism analysis suggest that maternal transmission of the Gsalpha mutation may be required for full expression of clinical hormone resistance. To test this hypothesis, we studied transmission of a frameshift mutation in Gsalpha through three generations of a pedigree affected by AHO and PHP-Ia. While all family members carrying this loss-of-function mutation in one Gsalpha allele had AHO, neither the presence of the mutation nor the degree of reduction of erythrocyte Gsalpha bioactivity allowed prediction of phenotype (AHO alone versus AHO and PHP-Ia). Paternal transmission of the mutation (from the patriarch of the first generation to three members of the second generation) was not associated with concurrent PHP-Ia, but maternal transmission (from two women in the second generation to four children in the third generation) was invariably associated with PHP-Ia. No expansion of an upstream short CCG nucleotide repeat region was detected, nor was there evidence of uniparental disomy by polymorphism analysis. This report, the first to document the effects across three generations of both paternal and maternal transmission of a specific Gsalpha mutation, strongly supports the hypothesis that a maternal factor determines full expression of Gsalpha dysfunction as PHP-Ia.     

The influence of sex hormones on obesity across the female life span

Women have a higher prevalence of obesity than men in most developed countries. Obesity affects many aspects of women's health by increasing risk for heart disease, diabetes, breast cancer, and infertility. One reason for the gender difference in obesity may be that fluctuations in reproductive hormone concentrations throughout women's lives uniquely predispose them to excess weight gain. Studies in experimental animals and women have shown that hormonal changes across the menstrual cycle affect calorie and macronutrient intake and alter 24-hour energy expenditure. Pregnancy is a significant factor in the development of obesity for many women. Various factors are associated with excess weight retention following pregnancy, including weight gain during pregnancy, ethnicity, dietary patterns, and interval between pregnancies. There is a need to tailor recommendations for energy intake during pregnancy to individual women, and recent evidence also suggests that the timing of weight gain during pregnancy is a critical factor. Menopause is also a high-risk time for weight gain in women. Although the average woman gains 2-5 pounds during menopausal transition, some women are at risk for greater weight gains. There is also a hormonally driven shift in body fat distribution from peripheral to abdominal at menopause, which may increase health risks in older women. Hormone therapies have varying impacts on body weight and fat distribution. In summary, hormonal fluctuations across the female life span may explain the increased risk for obesity in women. Awareness of these factors allows development of targets for prevention and early intervention.     

Seizure activity and lesions of neuronal cells by intrahippocampal injection of guanidinosuccinic acid in rats]

Intrahippocampal injection(ihci) of guanidinosuccinic acid (GSA) to rats, induced typical generarized clonic seizures and epileptiform discharges in electrohippocampogram (EHG) and electrocorticogram (ECoG), degenerative changes of neuronal cells in the injected side hippocampus. The pyramidal cells in CA1 area were found to be more vulnerable to GSA than the granular cells. Phenobarbital and phenytoin are typical antiepiletics, but in no case did they successfully protect against GSA induced convulsions, epileptiform discharges in the EHG and ECoG and neurolysis. Ketamine, a selective noncompetitive NMDA receptor antagonist, was shown to protect against not only seizures, but also neuronal cell damage induced by GSA. All these results indicate that GSA very like the endogenous excitatory amino acid, glutamic acid, it also has such effects mentioned above. Therefore, the NMDA receptor may mediate both effects of GSA.     

Vitamin C elevates red blood cell glutathione in healthy adults

Pre-transplant nephrectomy was done in a 25-year-old man for calculous pyelonephritis using a retroperitoneal laparoscopic approach with a newly devised ligature applicator-dissector- kidney retractor.     

A peculiar form of amicrobial pustulosis of the folds associated with systemic lupus erythematosus and other auto-immune diseases

This article continues the series of electronic microscopical investigations of tick attachment and host's inflammatory reaction in the attachment site. In all this works we used larvae of different Ixodid ticks but the same species of the host (white mouse), Ixodid species having different type of attachment. Dermacentor marginatus (Amosova, 1989a) is characterized by the superficial penetration of mouth parts, the abundance of cement around them and on the surface of the host's skin, the mouth parts of Hyalomma asiaticum are fully inserted and the superficial cement is minimal (Amosova, 1989b) and Ixodes ricinus has mouth parts inserted more deeply in the skin tissue of the host and the cement substance localised only on the surface of the skin at the 1st and 2nd days of feeding period. For this investigation we choose Haemaphysalis longicornis because it is known (see Kemp et al., 1982) that genus Haemaphysalis has the most superficial localisation of the mouth parts in the attachment site. We have studied a fine structure of cement cone and the cement substance surrounding the mouth parts in the skin and have demonstrated that it is very similar to the Dermacentor marginatus cement structure. The pattern of cellular response is similar to D. marginatus lesion too.