Descriptive analysis of eating regulation in obese and nonobese children.
Bite rate, sip rate, and concurrent activities of six 7-yr-old children, three obese and three nonobese, were observed at lunchtime over a six-month period. A procedure for decreasing bite rate, putting eating utensils down between bites, was implemented in a multiple-baseline across-subjects design. Sip rates and concurrent activities were observed to assess behavioral covariations. In addition, bite rate and amount of food completed were computed over six food categories to analyze food preferences. Results indicated the control of bite rate acorss all subjects, with a significant reduction in amount of food consumed. Correlations between the response classes indicated they were at least partially independent. Differences in eating behavior of obese and nonobese subjects were observed for breadstuffs and milk drinking. (+info)
Modification of behavioral and neural taste responses to NaCl in C57BL/6 mice: effects of NaCl exposure and DOCA treatment.
To investigate the possible role of peripheral gustatory responsiveness to changes in NaCl acceptance, we studied NaCl consumption and the chorda tympani nerve responses to lingual application of NaCl in C57BL/6ByJ mice. The mice were treated with 300 mM NaCl (given to drink in 96-h two-bottle tests with water) or with injections of deoxycorticosterone acetate (DOCA; 33 mg/kg daily). Naive mice were neutral to 75 mM NaCl, but mice previously exposed to 300 mM NaCl avoided 75 mM NaCl. The NaCl-exposed (300 mM for 4 days and 75 mM for 2 days) mice had enhanced amiloride-sensitive components of the chorda tympani responses to 10-30 mM NaCl applied at room temperature (24 degrees C). DOCA injections increased acceptance of 300 mM NaCl, but did not change the chorda tympani responses to 100-1000 mM NaCl. However, the DOCA-treated mice had enhanced amiloride-sensitive components of the chorda tympani responses to cold (12 degrees C) 10-30 mM NaCl. These data suggest that peripheral gustatory responsiveness possibly contributes to the NaCl aversion induced by exposure to concentrated NaCl, but not to the DOCA-induced increase of NaCl acceptance. (+info)
The effects of diet on the esterification of glycerol phosphate, dihydroxyacetone phosphate and 2-hexadecylglycerol by homogenates of rat adipose tissue.
1. Male rats were fed for 5 weeks after weaning on a diet containing (by weight) 59% of starch or on diets that contained 39% of starch and 20% of either sucrose, beef tallow or corn oil. 2. The rats fed on the beef tallow consumed more energy than did the rats fed on the starch and sucrose diets. The rats fed on the corn oil drank less water than did the other groups of rats. 3. There were no significant differences between the four groups in terms of body-weight gain, epididymal-fat-pad weight and in the size, number and triacylglycerol content of the adipocytes in the fat-pads. 4. There was a significant correlation (P less than 0.001) between the activities of glycerol phosphate acyltransferase and monoacylglycerol acyltransferase in individual rats. Both of these activities were highest in the group fed on the high-starch diet and both correlated with the consumption of glucose by individual rats in the four groups. 5. The percentage of glycerol phosphate converted into diacylglycerol and triacylglycerol was positively correlated with the mean diameters, surface area and triacylglycerol content of the adipocytes for individual rats and was greates in the sucrose-fed rats. 6. The specific activity of dihydroxyacetone phosphate acyltransferase was highest in the rats fed on beef tallow. This activity was positively correlated with the energy intake for all dietary groups over the 5-week feeding period. 7. The results are discussed in terms of the functions of the three routes of glycerolipid synthesis in adipose tissue. (+info)
Impact of social interactions in the community on the transmission of tuberculosis in a high incidence area.
BACKGROUND: Tuberculosis (TB) is transmitted by close contact with an infectious person. It is assumed that close contact occurs amongst household members and that contact outside the house is "causal" and does not play a major role in the transmission of TB. METHODS: This study was conducted in an impoverished area with a high incidence of TB and a low HIV seropositive prevalence. Thirty three households with 84 TB patients were identified between February 1993 and April 1996 and the transmission of TB was studied by combining Mycobacterium tuberculosis fingerprinting with in depth sociological interviews. RESULTS: Forty two strain genotypes were identified in the 84 patients. In 15 households all the patients had identical strains, in nine households all the patients had different strains, and in nine households some patients had identical strains and one had a different strain. In 26 houses at least one patient had a strain which formed part of a larger community cluster and in 12 of these households the patient(s) had contact with a community member who had the identical strain. In 58% of the cases the contact took place while drinking in social groups. CONCLUSION: In high incidence areas contact outside the household may be important for the transmission of TB. This contact often takes place during recreation which, in the case of this study of impoverished people, consisted of drinking in social groups. Social interaction patterns should be studied and understood for effective implementation of control strategies. (+info)
Genetics of mouse behavior: interactions with laboratory environment.
Strains of mice that show characteristic patterns of behavior are critical for research in neurobehavioral genetics. Possible confounding influences of the laboratory environment were studied in several inbred strains and one null mutant by simultaneous testing in three laboratories on a battery of six behaviors. Apparatus, test protocols, and many environmental variables were rigorously equated. Strains differed markedly in all behaviors, and despite standardization, there were systematic differences in behavior across labs. For some tests, the magnitude of genetic differences depended upon the specific testing lab. Thus, experiments characterizing mutants may yield results that are idiosyncratic to a particular laboratory. (+info)
Cardiovascular changes associated with dehydration and drinking in unrestrained, lactating goats.
The aim of this study was to investigate if the alertness connected with seeing water increased arterial blood pressure and heart rate to the same extent as the act of drinking, and if ingestion of warm water caused a different effect compared with ingestion of cool water on these cardiovascular variables. Seven goats of the Swedish domestic breed (Capra hircus) were used in a cross-over design. The animals were dehydrated for 24 h. They were allowed to watch water being prepared for 11-16 min, after which they were given access to warm (35 degrees C) or cool (15 degrees C) water. The goats drank 6.86 +/- 0.36 l of the warm water and 4.54 +/- 0.35 l of the cool water (P < 0.05) within the first hour. The arterial blood pressure, heart rate and activity of the animals were registered by an implanted telemetric device. Dehydration did not affect the cardiovascular variables, except before feeding in the morning, when the heart rate accelerated faster in dehydrated goats. Heart rate increased abruptly when dehydrated goats saw water being prepared, remained at the increased level during drinking and then slowly declined. It increased again during the afternoon feeding, to a level similar to that on control days, but between 18.00 and 06.00 h the heart rate was higher than during control nights. Blood pressure did not change when the goats saw water, but increased when they drank. On the morning following rehydration, the rise in heart rate in response to feeding was delayed compared with that during control and dehydration periods. It is concluded that seeing water caused arousal in the goats, resulting in an accelerated heart rate. The additional rise in blood pressure during the act of drinking appears to be a combination of excitement and sensory inputs from the pharyngeal region, causing a temporary activation of the sympathetic nervous system. (+info)
Congenital renal dysplasia and psychogenic polydipsia in a Bernese mountain dog.
Congenital renal dysplasia was tentatively diagnosed, based on ultrasound and an intravenous urogram, in a 5-month-old female with polyuria and polydipsia. Creatinine clearance measurement revealed that the renal dysplasia was not the cause of the polyuria. A modified water deprivation test eliminated other differential diagnoses and confirmed psychogenic polydipsia. (+info)
Influence of S-adenosyl-L-methionine on chronic mild stress-induced anhedonia in castrated rats.
1. S-adenosyl-L-methionine (SAMe) is the most important methyl donor in the brain and is essential for polyamine synthesis. Methyl group deficiency in the brain has been implicated in depression; on the other hand, polyamines enhance phosphorylation processes, and phosphorylation of functional proteins in neurons in involved in the therapeutic mechanisms of antidepressants. 2. The effect of SAMe in an animal model of 'depression', the chronic mild stress-induced anhedonia, was studied using long-term castrated male and female Lister hooded rats. 3. Chronic daily exposure to an unpredictable sequence of mild stressors produced, within 3 weeks, a significant reduction of the consumption of a sucrose solution. SAMe (100, 200 or 300 mg kg-1 daily i.m.) while having no influence on sucrose intake in non-stressed animals, dose-dependently reinstated sucrose consumption within the first week of treatment, both in male and in female stressed rats. Imipramine (10 mg kg-1 daily i.p.) produced a similar effect after a 3 week treatment. 4. Similarly, a palatable food reward-induced place preference conditioning was developed in SAMe (200 or 300 mg kg-1 daily i.m.)--and in imipramine (10 mg kg-1 daily i.p.)--treated chronically stressed animals (males and females), whilst it could not be obtained in vehicle-treated rats. 5. Moreover, the same doses of SAMe (but not of imipramine) restored the exploratory activity and curiosity for the environment (rearing), in the open-field test. 6. While imipramine caused a blockade of the growth throughout the treatment, SAMe produced only a transient growth arrest during the first week of treatment. 7. These results show that SAMe reverses an experimental condition of 'depression-like' behaviour in rats, the effect being more rapid and complete than that of imipramine, and without apparent side effects. (+info)