Effects of acute and chronic ingestion of tolbutamide in the chicken

The effects of acute and chronic ingestion of tolbutamide were studied in the growing chicken. After an oral load of 100 or 25 mg tolbutamide/kg b.w., plasma insulin levels increased in a dose-dependent manner but to relatively low levels for about 10 min, while 10-20 min following tolbutamide, plasma glucose levels were markedly decreased and remained so for 2--5 hr. After 100 mg tolbutamide/kg, the profound hypoglycaemia which developed, was generally accompanied by symptoms resembling an hypoglycaemic coma: panting, muscular flacidity and convulsion. Body temperature and plasma calcium levels were not changed during and after tolbutamide-induced insulin release. In the chicken, tolbutamide response is therefore characterized by a fugitive insulin release and a profound and prolonged hypoglycaemia which suggest that the action of insulin is potentiated by other factors. Chronic ingestion of tolbutamide in the diet transiently (for one week) increased the live body weight of a dose of 400 mg tolbutamide/kg of diet. Long term (5 weeks) fasting plasma glucose levels were unchanged and fasting plasma insulin levels were decreased in the chronic tolbutamide treated chickens.     

Inhibitory effects of tunicamycin and 2-deoxyglucose on thyroglobulin synthesis

The kinetic incorporation of labelled sugars and amino acids by rat thyroid hemilobes was measured in the presence of 2-deoxyglucose and tunicamycin, inhibitors of the glycosylation of glycoproteins. With either inhibitor the carbohydrate content of exocytosed thyroglobulin was only slightly decreased (less than 20% of control) whereas the rate of exocytosis was strongly inhibited (by 60-80%). As no intracellular accumulation or proteolysis of non-glycosylated molecules was detected, the reduced rate of thyroglobulin release seems essentially due to a decrease in protein synthesis. In a whole cell system (hemilobes), it is impossible to uncouple glycosylation and protein synthesis by incubation with tunicamycin; 50 micrograms/ml tunicamycin for 270 min inhibited total [3H]-glucosamine and 14C-labelled amino acid incorporation by 65% and 33% respectively. This can be contrasted with cell-free incubation of thyroid rough microsomes where glycosylation was blocked by the same tunicamycin concentration (90% inhibition of N-[3H]acetylglucosamine transfer from UDP-N-[3H]acetylglucosamine) whilst ongoing protein synthesis was not significantly modified (less than 4% inhibition). This clearly suggests that, in thyroid follicular cells, a regulatory link exists between the synthesis of the peptide moiety of a glycoprotein and its glycosylation.     

Public interest activities of APA members.

Surveyed public interest activities of 990 American Psychological Association (APA) members. Activities are presented in terms of the percentage of Ss performing them, the amount of time invested during a 12-mo period, and the extent to which they were uncompensated. Results show that (1) slightly more than half of the activities were primarily uncompensated, (2) 4% of the Ss did no public interest work during the past year, and (3) 9% reported doing public interest work on almost a full-time basis. The median APA member reported spending nearly 300 hrs a year on public interest activity. (18 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Performance of a Noncoherent FSK Receiver Preceded by a Bandpass Limiter

Many applications of the bandpass limiter involve either coherent or noncoherent demodulation following the limiter. In this paper we study the performance of a noncoherent frequency-shift keying (FSK) receiver when it is preceded by a bandpass limiter. In particular, we obtain expressions for signal suppression- factor, output signal-to-noise ratio (SNR), and error probability from which one can assess the degradation in performance of the receiver due to the presence of the limiter. Both narrow-band and wide-band cases are treated thus covering situations where no frequency uncertainty exists (i.e., known carrier frequency) as well as large-frequency uncertainties. Also discussed is the first-order signal plus noise probability density function (pdf) following noncoherent demodulation.     

An experimental study of the relation between nursing care and patient welfare.

4 experiments were conducted in an ongoing hospital setting to test the hypothesis that increasing the amount and quality of nursing care would produce improvements in patient welfare. Changes introduced on experimental wards consisted of increasing the size of the nursing staff, conducting inservice-education programs, and combining increased staffing and inservice education. With the exception of a reduction in patient complaints during 1 experiment, no improvement in patient welfare was produced. Results suggest that there is a limit to the contribution which nursing can make to patient welfare and that this limit is much closer to the existing level of care than was formerly thought. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Learning during sleep?

Studies on the sleep-learning phenomenon are criticized in terms of weaknesses in experimental design, statistics and methodology employed, and criteria of sleep. While it is highly speculative that the studies reviewed show that sleep-learning is possible, "The conditions under which the results were found tend more to support the contention that some learning takes place in a special kind of waking state wherein Ss apparently do not remember later on if they had been awake. This may be of great practical importance from the standpoint of economy in study time, but it cannot be construed as sleep-learning." 25 references. (PsycINFO Database Record (c) 2010 APA, all rights reserved)