Uremic anorexia: a consequence of persistently high brain serotonin levels? The tryptophan/serotonin disorder hypothesis.
(33/485)
Anorexia is a frequent part of uremic syndrome, contributing to malnutrition in dialysis patients. Many factors have been suggested as responsible for uremic anorexia. In this paper we formulate a new hypothesis to explain the appetite disorders in dialysis patients: "the tryptophan/serotonin disorder hypothesis." We review current knowledge of normal hunger-satiety cycle control and the disorders described in uremic patients. There are four phases in food intake regulation: (1) the gastric phase, during which food induces satiety through gastric distention and satiety peptide release; (2) the post absorptive phase, during which circulating compounds, including glucose and amino acids, cause satiety by hepatic receptors via the vagus nerve; (3) the hepatic phase, during which adenosine triphosphate (ATP) concentration is the main stimulus inducing hunger or satiety, with cytokines inhibiting ATP production; and (4) the central phase, during which appetite is regulated through peripheral (circulating plasma substances and neurotransmitters) and brain stimuli. Brain serotonin is the final target for peripheral mechanisms controlling appetite. High brain serotonin levels and a lower serotonin/dopamine ratio cause anorexia. Plasma and brain amino acid concentrations are recognized factors involved in neurotransmitter synthesis and appetite control. Tryptophan is the substrate of serotonin synthesis. High plasma levels of anorectics such as tryptophan (plasma and brain), cholecystokinin, tumor necrosis factor alpha, interleukin-1, and leptin, and deficiencies of nitric oxide and neuropeptide Y have been described in uremia; all increase intracerebral serotonin. We suggest that brain serotonin hyperproduction due to a uremic-dependent excess of tryptophan may be the final common pathway involved in the genesis of uremic anorexia. Various methods of ameliorating anorexia by decreasing the central effects of serotonin are proposed. (+info)
An assessment of various household food security measures in Hawaii has implications for national food security research and monitoring.
(34/485)
The Core Food Security Module (CFSM), the national food security monitoring tool, requires three affirmative responses to categorize households as food insecure. If this tool is unreliable or inaccurate, vulnerable segments of our population may be adversely affected. The objectives of the present study were to assess the credibility of applying the CFSM categorical measure to a population sample from Hawaii and to assess the concurrent validity of the CFSM, the new face-valid measure and measures adapted from the Radimer/Cornell (RC) measure and Community Childhood Hunger Identification Project. The sample included 1469 respondents gathered through a statewide telephone sample and 144 food pantry recipients. Responses to the 18 CFSM questions were used to create all four measures. The credibility of the CFSM categorical measure was also assessed via comparisons with individual items and with the 1995 national modal CFSM response pattern. Categorical measures were compared across food security prevalence estimates and indices of income and vegetable intake and with the CFSM scale measure. Differences in the modal response pattern between samples affected CFSM categorization. Only 36% of households followed the Hawaii modal response pattern, and categorization was not consistent with the content of key items. Although 85% of the households were classified as food secure by the CFSM, only 78% were classified as food secure with each of the other food security measures. Concurrent validity of all measures was confirmed. A reassessment of the national CFSM categorical measure appears warranted. (+info)
CA1-specific N-methyl-D-aspartate receptor knockout mice are deficient in solving a nonspatial transverse patterning task.
(35/485)
In both humans and animals, the hippocampus is critical to memory across modalities of information (e.g., spatial and nonspatial memory) and plays a critical role in the organization and flexible expression of memories. Recent studies have advanced our understanding of cellular basis of hippocampal function, showing that N-methyl-d-aspartate (NMDA) receptors in area CA1 are required in both the spatial and nonspatial domains of learning. Here we examined whether CA1 NMDA receptors are specifically required for the acquisition and flexible expression of nonspatial memory. Mice lacking CA1 NMDA receptors were impaired in solving a transverse patterning problem that required the simultaneous acquisition of three overlapping odor discriminations, and their impairment was related to an abnormal strategy by which they failed to adequately sample and compare the critical odor stimuli. By contrast, they performed normally, and used normal stimulus sampling strategies, in the concurrent learning of three nonoverlapping concurrent odor discriminations. These results suggest that CA1 NMDA receptors play a crucial role in the encoding and flexible expression of stimulus relations in nonspatial memory. (+info)
Long-term prognosis in children with recurrent abdominal pain.
(36/485)
The present study is a follow-up of 34 cases admitted to a paediatric department with recurrent abdominal pain (RAP) in 1942 and 1943. 45 persons without a history of RAP were selected at random and included as controls. Using a questionnaire, there was a higher incidence of gastrointestinal symptoms among persons with a history of RAP during childhood than among controls (P less than 0.05). 18 of the original 34 cases who still had symptoms were re-examined; 11 had a clinical picture consistent with a diagnosis of irritable colon, 5 had a picture compatible with both irritable colon and peptic ulcer/gastritis, and 2 had duodenal ulcer. Abdominal pains occurred no more frequently among children of parents who had had RAP during childhood than among children of parents without such a history. However, there was a higher incidence of abdominal pain among children of parents who were complaining of abdominal discomfort at the time of the investigation than among children whose parents were without such symptoms (P less than 0.005). (+info)
Food insufficiency, family income, and health in US preschool and school-aged children.
(37/485)
OBJECTIVES: This study investigated associations between family income, food insufficiency, and health among US preschool and school-aged children. METHODS: Data from the third National Health and Nutrition Examination Survey were analyzed. Children were classified as food insufficient if the family respondent reported that the family sometimes or often did not get enough food to eat. Regression analyses were conducted with health measures as the outcome variables. Prevalence rates of health variables were compared by family income category, with control for age and gender. Odds ratios for food insufficiency were calculated with control for family income and other potential confounding factors. RESULTS: Low-income children had a higher prevalence of poor/fair health status and iron deficiency than high-income children. After confounding factors, including poverty status, had been controlled, food-insufficient children were significantly more likely to have poorer health status and to experience more frequent stomachaches and headaches than food-sufficient children; preschool food-insufficient children had more frequent colds. CONCLUSIONS: Food insufficiency and low family income are health concerns for US preschool and school-aged children. (+info)
Food insecurity is positively related to overweight in women.
(38/485)
Although individuals with poor food security might be expected to have reduced food intake, and thus reduced body fat and less likelihood of being overweight, these associations have not been adequately studied. The purpose of the current study was to examine the relationship between food insecurity and overweight as measured by body mass index (BMI) using data from the nationally representative 1994-1996 Continuing Survey of Food Intakes by Individuals (CSFII). Overweight was defined as BMI >27.3 kg/m(2) for women and 27.8 kg/m(2) for men. Food insecurity was related to overweight status for women (n = 4509, P < 0.0001), but not for men (n = 4970, P = 0.44). Excluding the 11 severely insecure women, the prevalence of overweight among women increased as food insecurity increased, from 34% for those who were food secure (n = 3447), to 41% for those who were mildly food insecure (n = 966) and to 52% for those who were moderately food insecure (n = 86). Food insecurity remained a significant predictor of overweight status, after adjustment for potentially confounding demographic and lifestyle variables (P < 0.01). In a logistic regression analysis, mildly insecure women were 30% more likely to be overweight than those who were food secure [odds ratio (OR) 1.3, P = 0.005]. Thus, food insecurity had an unexpected and paradoxical association with overweight status among women with a higher prevalence of overweight among the food insecure, and a resulting potential for increased incidence of obesity-related chronic diseases. Given that the rates of both overweight and food insecurity are on the rise, this research area warrants further investigation. (+info)
Is food insufficiency associated with health status and health care utilization among adults with diabetes?
(39/485)
OBJECTIVES: Preliminary studies have shown that among adults with diabetes, food insufficiency has adverse health consequences, including hypoglycemic episodes and increased need for health care services. The purpose of this study was to determine the prevalence of food insufficiency and to describe the association of food insufficiency with health status and health care utilization in a national sample of adults with diabetes. METHODS: We analyzed data from adults with diabetes ( n =1,503) interviewed in the Third National Health and Nutrition Examination Survey. Bivariate and multivariate analyses were used to examine the relationship of food insufficiency to self-reported health status and health care utilization. RESULTS: Six percent of adults with diabetes reported food insufficiency, representing more than 568,600 persons nationally (95% confidence interval, 368,400 to 768,800). Food insufficiency was more common among those with incomes below the federal poverty level (17% vs 4%, P < or = .001). Adults with diabetes who were food insufficient were more likely to report fair or poor health status than those who were not (63% vs 43%; odds ratio, 2.2; P=.05). In a multivariate analysis, fair or poor health status was independently associated with poverty, nonwhite race, low educational achievement, and number of chronic diseases, but not with food insufficiency. Diabetic adults who were food insufficient reported more physician encounters, either in clinic or by phone, than those who were food secure (12 vs 7, P<.05). In a multivariate linear regression, food insufficiency remained independently associated with increased physician utilization among adults with diabetes. There was no association between food insufficiency and hospitalization in bivariate analysis. CONCLUSIONS: Food insufficiency is relatively common among low-income adults with diabetes and was associated with higher physician utilization. (+info)
Involvement of human amygdala and orbitofrontal cortex in hunger-enhanced memory for food stimuli.
(40/485)
We used positron emission tomography to measure regional cerebral blood flow (rCBF) in 10 healthy volunteers performing a recognition memory task with food and non-food items. The biological salience of the food stimuli was manipulated by requiring subjects to fast before the experiment and eat to satiation at fixed time points during scanning. All subjects showed enhanced recognition of food stimuli (relative to non-food) in the fasting state. Satiation significantly reduced the memory advantage for food. Left amygdala rCBF covaried positively with recognition memory for food items, whereas rCBF in right anterior orbitofrontal cortex covaried with overall memory performance. Right posterior orbitofrontal rCBF covaried positively with hunger ratings during presentation of food items. Regression analysis of the neuroimaging data revealed that left amygdala and right lateral orbitofrontal rCBF covaried as a function of stimulus category (i.e., food vs non-food). These results indicate the involvement of amygdala and discrete regions of orbitofrontal cortex in the integration of perceptual (food), motivational (hunger), and cognitive (memory) processes in the human brain. (+info)