Miller-Fisher syndrome associated with Campylobacter jejuni bearing lipopolysaccharide molecules that mimic human ganglioside GD3.

A Campylobacter jejuni strain of serotype O:10 was isolated from a patient who had Miller-Fisher syndrome. In its biochemical reactions and cellular morphology, the isolate was characteristic of typical C. jejuni. Antibodies against extracted lipopolysaccharide (LPS) were detected by passive hemagglutination in the acute- and convalescent-phase patient sera. By sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting with the O:10 antiserum, it was demonstrated that the strain possessed both low- and high-molecular-weight molecules. Chemical analysis of the LPS revealed that the core oligosaccharide has a terminal trisaccharide epitope consisting of two molecules of sialic acid linked to galactose, a structure reflecting the terminal region of human ganglioside GD3. As this trisaccharide is also present in LPS cores of serotype O:19 strains from patients with Guillain-Barré syndrome but not in cores of nonneuropathic C. jejuni, a possible role for the trisaccharide in the etiology of neuropathies is indicated, and a difference for distinguishing neuropathic strains from nonneuropathic strains may be the presence of a sialyltransferase required for the synthesis of this trisaccharide.

Gonadotrophin and steroid concentrations in jugular and testicular venous plasma in stallions before and after GnRH injection.

Six normal stallions of light horse breeds aged 5-17 years were used from fall to winter to investigate the difference between steroid hormone concentrations in testicular and jugular venous blood before and after exogenous GnRH. At 48 h before experimentation, an indwelling cannula was placed surgically in the testicular vein of the stallion. After the stallion recovered from anaesthesia, a catheter was placed percutaneously in the jugular vein. Each stallion was housed in a tie stall to allow simultaneous sampling of jugular or testicular blood. On the first and second sampling days, respectively, 1 ml of physiological saline solution and a 1 ml solution of GnRH (25 micrograms) were administered intravenously. Samples were taken from both sites at intervals from 60 min before treatment to 780 min after treatment. Plasma was analyzed for luteinising hormone (LH) and follicle-stimulating hormone (FSH), 17 beta-hydroxyandrogens (androgens), oestrone and oestrogen conjugates by radioimmunoassay. Pre-treatment (baseline) plasma concentrations of both LH and FSH between jugular and testicular samples were similar. The difference between basal levels of jugular and testicular androgens, oestrone and oestrogen conjugates were 144-fold, 60-fold and 13-fold respectively, although individual variation was observed. A low dose of exogenous GnRH produced a significant LH and FSH response in testicular and jugular plasma (P less than 0.05). There were no significant changes in steroid secretion caused by the increases in LH and FSH (P greater than 0.05), although individual variation in the androgen response was apparent (P less than 0.1). There was a positive correlation between basal testicular venous androgen levels and the magnitude of the FSH response to GnRH (P less than 0.05). Significant correlations between baseline oestrogens and the magnitude of the gonadotrophin response was not observed. Surgery depressed jugular oestrogen conjugate values (P less than 0.001) when compared to pre-surgical samples. Spermatogenesis also was depressed (P less than 0.01) by surgical manipulation, although total viable spermatozoa counts returned to normal limits within 3-5 months post operatively. We developed a model that allows the study of dynamic endocrine events associated with the hypophyseal-gonadal axis of the stallion. Our findings confirm the presence of a testicular-jugular hormone gradient in the unanaesthetized stallion. We have demonstrated that a relatively low dose of GnRH can induce a significant gonadotrophin response and a variable androgen response, but not a significant oestrogen response. Although baseline levels of androgens and not oestrone and oestrogen conjugates appeared to affect pituitary responsiveness, other steroidogenic components may be involved.(ABSTRACT TRUNCATED AT 400 WORDS)

The comparative efficacy of minocycline and penicillin-V in Staphylococcus aureus skin and soft tissue infections.

The antistaphylococcal properties of orally administered minocycline and penicillin-V were compared for one hundred and fifteen patients receiving minocycline and one hundred and twenty-eight receiving penicillin-V for various types of cutaneous infections. The majority of bacterial isolates were staphylococcal organisms. Of these 82 percent showed initial in vitro sensitivity to minocycline while only 20 percent did to penicillin-V. The percentage of clinical cures was higher with minocycline (74 percent) than with penicillin-V (54 percent), however, most patients, in both groups, showed clinical improvement. The rate of clinical improvement appeared to be significantly faster with minocycline. There was a higher percentage of adverse, chiefly vestibular, effects in the minocycline group (16 percent vs 7 percent). The study clearly demonstrates the superior antistaphylococcal properties of minocycline as compared with penicillin-V.