Prevalence and genetic aspects of deaf mutism in Shanghai

Two hundred and eighty-five cases of congenital deaf mutism were ascertained in a population of 483,611 in Zhabei District in Shanghai. The prevalence was 0.059% (1:1697). Inherited cases accounted for 84.83% of all cases. The mode of inheritance was autosomal recessive with complete penetrance and heterogeneity (consisting of at least five different loci). The fitness was 77.63%, the coefficient of selection was 0.2237, the mutation rate was 1.119 x 10(-4) mutation/gamete, and no heterozygote advantage was proven.

Direct evidence for the interaction of the nucleotide affinity analog 5'-p-fluorosulfonylbenzoyl adenosine with a platelet ADP receptor

Previous reports have indicated that the nucleotide affinity analog 5'-p-fluorosulfonylbenzoyl adenosine (FSBA) at concentrations between 40 and 100 mumol/L and at times greater than 20 minutes covalently modifies a single protein component on the external platelet membrane surface and that adenosine diphosphate (ADP) protects against this reaction. That this protein is an ADP receptor linked to platelet activation is shown by FSBA inhibition of ADP-mediated platelet shape change, aggregation, and fibrinogen receptor exposure. In this report, further evidence for the interaction of FSBA with the ADP receptor on platelets is provided by the observation that FSBA at high concentrations (100 to 500 mumol/L) behaves as a weak agonist to produce platelet shape change within one minute as detected by spectroscopic assay and scanning electron microscopy with concomitant phosphorylation of the light chain of platelet myosin. The specificity of FSBA as an agonist is demonstrated by inhibition of FSBA-induced shape change by ATP and the covalent incorporation of SBA as well as the failure of 5'-fluorosulfonylbenozoyl guanosine (FSBG) to cause shape change. In contrast, incubation of platelets with low concentrations of [3H]-FSBA (40 mol/L) is not associated with stimulation of platelet shape change or myosin light chain phosphorylation.

Effects of adenosine 3',5'-cyclic monophosphate, forskolin, and cholera toxin on hormone production in human term placental cells

Trophoblast cells from human term placenta in monolayer culture were used to investigate the role of adenosine 3',5'-cyclic monophosphate in the production of human chorionic gonadotropin and estradiol-17 beta. The intracellular concentration of adenosine 3',5'-cyclic monophosphate was elevated by (1) addition of an adenosine 3',5'-cyclic monophosphate analogue, 8-bromoadenosine 3',5'-cyclic monophosphate, (2) inhibition of the hydrolysis of Gs-GTP complex by cholera toxin, and (3) direct stimulation of adenylate cyclase with forskolin. Addition of 2 mmol/L of 8-bromoadenosine 3',5'-cyclic monophosphate markedly increased the accumulation of human chorionic gonadotropin in the culture medium on days 2, 3, and 4 of treatment. Likewise, addition of cholera toxin (0.2 microgram/ml) or forskolin (50 mumol/L) also enhanced human chorionic gonadotropin production. On the other hand, the production of estradiol-17 beta was significantly inhibited by 8-bromoadenosine 3',5'-cyclic monophosphate, at the same time that human chorionic gonadotropin production was enhanced in the same experiments. These results further support a differential role of adenosine 3',5'-cyclic monophosphate on human chorionic gonadotropin and estradiol-17 beta production in the human term placenta.

Serotonin turnover in raphe neurons transplanted into rat hippocampus

Injections of the neurotoxin, 5,7-dihydroxytryptamine, into rostral raphe nuclei in rats reduced serotonin (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) in hippocampus to 35-50% of normal levels but only reduced 5-HT synthesis and catabolism by 20-35%. The small reduction in 5-HT metabolism as compared to depletion of 5-HT suggests that 5-HT turnover was increased in nerve terminals that survived the neurotoxin lesion. Transplantation of rat fetal raphe cells into the 5-HT-denervated hippocampus restored 5-HT and 5-HIAA levels and 5-HT synthesis to 125-150% of normal. This demonstrates that transplantation of fetal raphe tissue can restore metabolism to normal levels in the 5-HT denervated hippocampus.