Food intake is inversely correlated with central nervous system histamine receptor (H1) concentrations in male Sprague-Dawley rats fed normal, low protein, low energy or poor quality protein diets

The reported studies were designed to examine relationships between whole-brain histamine receptors (H1) and food intake in male Sprague-Dawley rats. Three different experiments were conducted. In each experiment, control rats were fed normal protein (25 g casein/100 g food) and normal metabolizable energy (16.21 kJ/100 g food) diets. Feeding low protein diets (1 g casein/100 g food) elevated central H1 receptor concentrations (P < 0.0027) and reduced voluntary food intake (P < 0.007) compared with normal diets. Feeding low energy diets lowered H1 receptor concentrations (P < 0.0089) and increased voluntary food intake (P < 0.0012). Low quality protein diets also affected the central nervous histaminergic system. Whole-brain H1 receptor concentrations were significantly higher for rats fed low quality protein (25 g gelatin/100 g food) compared with rats fed casein (P < 0.0001). Rats fed medium quality protein (25 g wheat gluten/100 g food) or low quality protein ate significantly less food (P < 0.0001). In all experiments, dietary manipulation affected central histamine receptors. Elevated concentrations of H1 receptors were associated with a decrease in food intake whereas lowered concentrations of H1 receptors were associated with an increase in food intake (P < 0.001). The results of these experiments support the hypothesis that central histamine H1 receptor concentrations in male rats are inversely correlated with voluntary food intake and affected by dietary composition.     

Effect of sympathectomy on mechanical properties of common carotid and femoral arteries

Sympathetic stimulation is accompanied by a reduction of arterial distensibility, but whether and to what extent elastic and muscle-type arterial mechanics is under tonic sympathetic restraint is not known. We addressed this issue by measuring, in the anesthetized rat, the diameters of the common carotid and femoral arteries with an echo-Doppler device (NIUS 01). Blood pressure was measured by a catheter inserted contralaterally and symmetrically to the vessel where the diameter was measured. Arterial distensibility over the systolic-diastolic pressure range was calculated according to the Langewouters formula. Data were collected in 10 intact (vehicle pretreatment) and 9 sympathectomized (6-hydroxydopamine pretreatment) 3-month-old Wistar-Kyoto rats. Compared with the intact animals, sympathectomized rats showed a marked increase in arterial distensibility over the entire systolic-diastolic pressure range. When quantified by the area under the distensibility-pressure curve, the increase was 59% and 62% for the common carotid and femoral arteries, respectively (P<.01 for both). In the femoral but not in the common carotid artery, sympathectomy was accompanied also by an increase in arterial diameter (+18%, P<.05 versus intact). Therefore, in the anesthetized normotensive rat, sympathetic activity exerts a tonic restraint on large-artery distensibility. This restraint is pronounced in elastic vessels and even more pronounced in muscle-type vessels.     

Pulmonary sarcoidosis: morphologic associations of airflow obstruction at thin-section CT

PURPOSE: To identify relationships between the obstructive defects of pulmonary sarcoidosis and the computed tomographic (CT) patterns of disease. MATERIAL AND METHODS: CT scans obtained in 45 patients were scored semiquantitatively for extent of five CT patterns, and the functional importance of each pattern was evaluated. RESULTS: The most prevalent CT patterns were decreased attenuation (n = 40), a reticular pattern (n = 37), and a nodular pattern (n = 36). At univariate and multivariate analyses, a reticular pattern was the main determinant of functional impairment, particularly airflow obstruction. The extent of a reticular pattern was independently associated with airflow obstruction, as shown by the inverse relationships with the forced expiratory volume in 1 second (FEV1) (P < .001), FEV1-forced vital capacity ratio (P < .01), maximum expiratory flow at 25% above residual volume (P < .001), and maximum expiratory flow at 50% above residual volume (P < .001) and the positive relationship with the residual volume-total lung capacity ratio (P < .001). CONCLUSION: In sarcoidosis, CT features compatible with small airways disease are common but contribute little to airflow obstruction, particularly in more advanced disease, which is characterized by an extensive reticular pattern. A reticular pattern at CT is the major morphologic association of airflow obstruction.     

Inflammatory breast cancer and body mass index

PURPOSE: No studies have investigated the etiology of inflammatory breast cancer (IBC), the most lethal form of breast cancer. Because high body mass index (BMI) is associated with decreased risk of premenopausal breast cancer but increased risk of postmenopausal breast cancer, we evaluated whether high BMI was a risk factor for IBC. PATIENTS AND METHODS: In a case-comparison study, we matched by ethnicity and registration date 68 IBC patients treated at The University of Texas M.D. Anderson Cancer Center from 1985 to 1996 with 143 patients with non-IBC and 134 patients with cancer at sites other than the breast or reproductive tract (non-breast cancer). The non-breast cancer group was used in lieu of a population-based, healthy control group, which was not available. RESULTS: IBC patients were younger at menarche and the time of their first live birth than non-IBC and non-breast cancer patients. The proportion of premenopausal IBC patients was higher than the proportion of premenopausal women in the comparison groups, although differences were not significant. There were no differences in height, but IBC patients were heavier (77.6 kg) than non-IBC (70.0 kg) and non-breast cancer patients (68.0 kg). After adjusting for other factors, women in the highest BMI tertile (BMI > 26.65 kg/m2) relative to the lowest tertile (BMI < 22.27) had significantly increased IBC risk (IBC v non-IBC, odds ratio [OR] = 2.45, 95% confidence interval [CI] = 1.05 to 5.73; IBC v non-breast cancer, OR = 4.52, 95% CI = 1.85 to 11.04). This association was not significantly modified by menopausal status and was independent of age at menarche, family history of breast cancer, gravidity, smoking status, and alcohol use. CONCLUSION: Our investigation showed that high BMI was significantly associated with an increased risk of IBC. This association did not vary by menopausal status, although IBC patients were more likely to be premenopausal. Confirming our findings and identifying other IBC risk factors may provide directions for future research on the aggressive nature of IBC.     

Mechanism of mosaic attenuation of the lungs on computed tomography in induced bronchospasm

The purpose of this study was to investigate whether hypoxic pulmonary vasoconstriction is the major determinant of the computed tomography (CT) pattern of mosaic attenuation in asthmatic patients with induced bronchoconstriction. Thin-section CT was performed at suspended full inspiration immediately and 30 min after methacholine bronchoprovocation in 22 asthmatic subjects, who were randomly assigned to breathe room air (group A, n = 8), oxygen via nasal prongs at 5 l/min (group B, n = 8), and oxygen via face mask at 12 l/min (group C, n = 6). CT changes were quantified in terms of global lung density and density in hypodense and hyperdense areas. Lung parenchymal density increases were greatest in group C and greater in group B than in group A, globally (P = 0.03) and in hypodense regions (P = 0.01). On bivariate analysis, the only change in cross-sectional area was related to change in global density. In hypodense regions, density change was related both to reduction in cross-sectional area (P < 0.0005) and to oxygen administration (P = 0.01). After correction for changes in global lung density, only oxygen was independently related to density increase in hypodense areas (P = 0.02). In induced bronchoconstriction, the CT appearance of mosaic attenuation can be largely ascribed to hypoxic vasoconstriction rather than to changes in lung inflation.     

Effect of chemotherapy on the larval mass and the long-term course of alveolar echinococcosis. Swiss Echinococcosis Study Group

The efficacy of long-term chemotherapy in nonresectable alveolar echinococcosis is debated, particularly because of the difficulty in defining therapeutic success. In this study the effect of chemotherapy on the parasitic mass was evaluated in a series of 37 patients. The patients had larval lesions documented by serial computed tomography studies at least 1.5 yr after chemotherapy (mean = 6.4 yr, range = 1.5 to 10.7 yr). The therapeutic regimen consisted of mebendazole (n = 34) or albendazole (n = 3) as previously described. The maximal areas of the parasitic lesions were assessed morphometrically by means of digital image analysis, utilizing the point-integration method, before and after chemotherapy. Marked regression of larval tissue occurred in 18 patients (group A; 48.6%), stationary lesions were noted in 13 patients (group C; 35.1%) and progression was found in 6 patients (group B; 16.2%). The three groups did not differ significantly with regard to age, plasma drug levels, duration of chemotherapy or initial size and composition of lesions (e.g., cystic cavities, degree of calcification). Despite morphologically successful chemotherapy in moist patients (e.g., 84%; groups A and C), late cholestatic complications after 1.5 to 11 yr of chemotherapy occurred in 10 patients (group A, n = 7; group C, n = 3; 4 of them died) and esophageal variceal bleeding occurred in 3 patients (relieved by sclerotherapy). These late complications were probably mainly due to posttherapy fibrosis of hilar structures. In conclusion, our data support the efficacy of chemotherapy. However, chemotherapy is not curative, and severe late complications were observed in patients with hilar (fibrotic) involvement.