Menadione and NH4Cl were reported to lower the islet content of reduced pyridine nucleotides. They were used to investigate the possible significance of NAD(P)H in the regulation of glucagon release by glucose and arginine. Menadione (10-25 mumol/l) enhanced arginine-stimulated glucagon release at a low glucose concentration (3.3 mmol/l), but failed both to affect glucagon secretion in the sole presence of glucose (3.3 mmol/l) and to suppress the inhibitory action of glucose 11.1 mmol/l upon glucagon output. In contrast to menadione, NH4Cl inhibited arginine-stimulated glucagon release at the low glucose concentration. The inhibitory action of glucose in high concentration upon glucagon release was not suppressed by NH4Cl. These findings do not permit to extrapolate to the A2-cell the concept that reduced pyridine nucleotides represent a major coupling factor in the nutritional regulation of hormonal release.

Ammonium Chloride↗

PubMedDate not supplied

Dynamics of insulin release by perifused insulin-producing tumoral cells: effects of glucose, forskolin, leucine, barium and theophylline.

Perifused tumoral insulin-producing cells, of the RINm5F line, display a high basal insulin output relative to their hormonal content. D-Glucose (2.8 or 16.7 mmol/l) causes a modest and monophasic increase in insulin output. The secretory response to D-glucose (1.4 to 16.7 mmol/l) is enhanced by forskolin, which exerts little effect in the absence of exogenous nutrient. L-Leucine (10.0 mmol/l) also stimulates insulin release from the perifused cells. The secretory response to these nutrient secretagogues in much less marked, however, than that evoked, in the absence of Ca2+, by the association of Ba2+ and theophylline. It is concluded that the dynamics of insulin release by the tumoral cells, when compared to that of normal islet cells, are characterized by several anomalies, including a high basal ratio between secretion and content, a low threshold (less than or equal to 1.4 mmol/l) in the secretory response to D-glucose, and a lesser responsiveness to nutrient than nonnutrient secretagogues.

Animals↗

PubMedDate not supplied

Pharmacokinetic studies of ambenonium chloride in patients with myasthenia gravis.

Serum levels of ambenonium chloride (AC) were monitored in 4 myasthenic patients. This determination revealed important intraindividual variations (up to 10-fold) over a period of 24 h. Levels varied considerably between different patients (maximum serum concentration of ambenonium chloride ranged from 0.129 to 0.812 micrograms/ml) and no correlation between the daily dose and the AUC was found. These characteristic properties of ambenonium chloride could explain the erratic pattern of bioavailability observed as well as the difficulty in controlling the disease in some patients.

Administration, Oral↗

PubMedDate not supplied

Unexpected diagnosis of Candida albicans meningitis in a premature neonate.

Candida albicans meningitis was found in an otherwise healthy 44-day-old premature infant whose birth weight was 1,860 gm. Almost no abnormal clinical or neurologic findings were present. The electroencephalogram, however, was abnormal. All previous body fluid cultures were negative. The combined use of amphotericin B and 5-fluorocytosine resulted in negative cerebrospinal fluid cultures after 3 weeks of therapy. Physical and psychomotor development remained normal on subsequent examination.

Antifungal Agents↗

PubMedDate not supplied

Water absorption in mortar determined by NMR.

Nuclear magnetic resonance (NMR) offers the possibility to determine moisture profiles in porous building materials. Moreover, the relaxation of the nuclear magnetic resonance signal can provide additional information on the water distribution in the microstructure. For mortar, it is shown that the transverse relaxation yields information on the distribution of water in the gel pores and capillary pores. Moisture profiles and relaxation were measured during water absorption. The effect of the drying treatment on the microstructure and the water absorption was investigated.

Absorption↗

PubMedDate not supplied

[Transplantation of the lower wisdom teeth. 6 years' experience].

The authors report their experience with reference to wisdom tooth transplantation involving fifteen patients over a period of 6 years. They exclude from this paper those transplantations which they have done using buds without roots and those with teeth with completely formed roots, which would not appear to be the best time for transplantation from a physiological standpoint. They feel that the main indication occurs when (multi-ring orthodontic treatment being impossible) the first molar is impossible to preserve and the wisdom tooth cannot apparently become functional. They describe their techniques. Despite the successess obtained (11 cases out of 15) with a follow-up of 6 years to one and a half years, the authors express a degree of reserve as far as the distant future is concerned with regard to possible rhizoclasia.

Adolescent↗

PubMedDate not supplied