Striatal dopaminergic modulation of lateral hypothalamic self-stimulation.

The bilateral application of crystalline 6-hydroxydopamine to the ventral anterior head of the corpus striatum of rats severely suppressed responding for electrical stimulation of the lateral hypothalamus. This suppression lasted for days or weeks, after other behavioral deficits in food and water intake and activity had recovered. Application of crystalline dopamine through the same cannulas temporarily reversed the impairment. Applications of crystalline dopamine to the same striatal region of untreated rats were more effective in enhancing self-stimulation than similar applications of norepinephrine.     

Evidence for ascending noradrenergic mediation of hypothalamic hyperphagia

Rats sustaining unilateral ablation of the ventral ascending noradrenergic bundle, in combination with a contralateral parasagittal knife cut rostrolateral to the ventromedial nucleus of the hypothalamus (VMN), became obese. Ablation of the ventral noradrenergic (NA) bundle was effective at both mammillary and midbrain levels. The weight gains produced by this asymmetrical technique were comparable to those obtained following bilateral parasagittal knife cuts. Rats with unilateral mammillary lesions that spared the ventral NA bundle or unilateral midbrain lesions which only partially destroyed the ventral NA bundle, in combination with the contralateral parasagittal knife cut, did not become obese. The neural substrate damaged in the production of hypothalamic hyperphagia thus appears to be that part of the ascending ventral NA bundle which projects medially through the effective parasagittal knife cut locus rostrolateral to the VMN.     

Pressure pain thresholds and musculoskeletal morbidity in automobile manufacturing workers

Objectives: Reduced pressure pain thresholds (PPTs) have been reported in occupational groups with symptoms of upper extremity musculoskeletal disorders (UEMSDs). The purpose of this study was to determine whether automobile manufacturing workers (n=460) with signs and symptoms of UEMSDs had reduced PPTs (greater sensitivity to pain through pressure applied to the skin) when compared with unaffected members of the cohort, which served as the reference group. The association of PPTs with symptom severity and localization of PE findings was investigated, as was the hypothesis that reduced thresholds would be found on the affected side in those with unilateral physical examination (PE) findings. Methods: PPTs were measured during the workday at 12 upper extremity sites. A PE for signs of UEMSDs and symptom questionnaire was administered. After comparison of potential covariates using t tests, linear regression multivariable models were constructed with the average of 12 sites (avgPPT) as the outcome. Results: Subjects with PE findings and/or symptoms had a statistically significant lower avgPPT than non-cases. AvgPPT was reduced in those with more widespread PE findings and in those with greater symptom severity (test for trend, P≤0.05). No difference between side-specific avgPPT was found in those with unilateral PE findings. Reduced PPTs were associated with female gender, increasing age, and grip strength below the gender-adjusted mean. After adjusting for the above confounders, avgPPT was associated with muscle/tendon PE findings and symptom severity in multivariable models. Conclusions: PPTs were associated with signs and symptoms of UEMSDs, after adjusting for gender, age and grip strength. The utility of this noninvasive testing modality should be assessed on the basis of prospective large cohort studies to determine if low PPTs are predictive of UEMSDs in asymptomatic individuals or of progression and spread of UEMSDs from localized to more diffuse disorders.     

The use of a personal digital assistant for dietary self-monitoring does not improve the validity of self-reports of energy intake

Underreporting of energy intake is a pervasive problem and resistant to improvement, especially among people with overweight and obesity. The goal of this study was to investigate whether the use of a personal digital assistant (PDA) for dietary self-monitoring would reduce underreporting prevalence and improve the validity of self-reported energy intake. Adults with overweight and obesity (n=61, 92% women, mean age 48.2 years, mean body mass index 32.3) were provided with a PalmZire 21 (Palm, Inc, Sunnyvale, CA) loaded with Calorie King's Diet Diary software (version 3.2.2, 2002, Family Health Network, Costa Mesa, CA). Subjects participated in a 24-week in-person behavioral weight control program and were asked to self-monitor their diet and exercise habits using the PDA. Basal metabolic rate and physical activity level were estimated at baseline. Energy intake from 7-day electronic food records were collected within the first month of the weight-control program. As subjects were actively losing weight, Bandini's adjustments were used to correct self-reported energy intake for weight loss. In this group, where 41% of the subjects were categorized as low-energy reporters, the use of a PDA did not improve validity of energy reporting when compared to what is reported in the literature.     

Maternal antioxidant intake in pregnancy and wheezing illnesses in children at 2 y of age

BACKGROUND: Low intakes of dietary antioxidants may contribute to increases in asthma and allergy. OBJECTIVE: We investigated the association of maternal total intakes (foods + supplements) of 10 antioxidant nutrients during pregnancy with wheezing and eczema in 2-y-old children. DESIGN: Subjects were 1290 mother-child pairs in an ongoing cohort study. Maternal dietary and supplement intakes were assessed by using a validated food-frequency questionnaire administered in the first and second trimesters. Antioxidant nutrient intakes were calculated, and the mean for each nutrient was considered to be the exposure during pregnancy. The outcomes of interest were any wheezing by the child during either the first or second year of life, recurrent wheezing in both years, and eczema in either the first or second year. RESULTS: No association was observed between maternal total intake of any antioxidant nutrient and eczema. In multivariate logistic regression models, the highest quartile compared with the lowest quartile of maternal total intakes of vitamin E [odds ratio (OR): 0.70; 95% CI: 0.48, 1.03] and zinc (OR: 0.59; 95% CI: 0.41, 0.88) was inversely associated with any wheezing at 2 y of age (P for trend = 0.06 and 0.01 over quartiles of intake for vitamin E and zinc, respectively). Similar results were obtained for recurrent wheezing at 2 y of age with vitamin E (OR: 0.49; 95% CI: 0.27, 0.90) and zinc (OR: 0.49; 95% CI: 0.27, 0.87) (P for trend = 0.05 and 0.06 over quartiles of intake for vitamin E and zinc, respectively). CONCLUSION: Our results suggest that higher maternal total intakes of antioxidants during pregnancy may decrease the risks for wheezing illnesses in early childhood.     

Dexmedetomidine does not increase the incidence of intracarotid shunting in patients undergoing awake carotid endarterectomy

Systemic administration of dexmedetomidine (DEX) decreases cerebral bloodflow (CBF) via direct alpha-2-mediated constriction of cerebral blood vessels and indirectly via its effect on the intrinsic neural pathway modulating vascular smooth muscle. Reduction in CBF without a concomitant decrease in cerebral metabolic rate has raised concerns that DEX may limit adequate cerebral oxygenation of brain tissue in patients with already compromised cerebral circulation (e.g., carotid endarterectomy [CEA]). In this study, we established the incidence of intraarterial shunting used as a sign of inadequate oxygen delivery in a consecutive series of 123 awake CEA performed in our institution using DEX as a primary sedative. Data were prospectively recorded in 151 patients who underwent CEA during the study period. Eighteen patients were sedated with midazolam and fentanyl (M/F) for medical or logistical reasons. Patients thought to be at risk of an intraoperative stroke were treated with a prophylactic intraarterial shunt. These patients, as well as those who required general anesthesia, were excluded from the final analysis. Five patients (4.3%) in the DEX group required intraarterial shunts. The incidence of shunting in patient undergoing awake CEA in our institution is 10% (historical control). No patients developed a stroke or other serious complications. It appears that the use of DEX as a primary sedative drug for CEA does not increase the incidence of intraarterial shunts.