Prolonged treatment with the beta3-adrenergic agonist CL 316243 induces adipose tissue remodeling in rat but not in guinea pig: 2) modulation of glucose uptake and monoamine oxidase activity.

Beta3-adrenergic agonists are well-recognited to promote lipid mobilisation and adipose tissue remodeling in rodents, leading to multilocular fat cells enriched in mitochondria. However, effects of beta3-adrenergic agonists on glucose transport are still controversial. In this work, we studied in white adipose tissue (WAT) the influence of sustained beta3-adrenergic stimulation on the glucose transport and on the mitochondrial monoamine oxidase (MAO) activity. As one-week administration of CL 316243 (CL, 1 mg/kg/d) induces beta-adrenergic desensitization in rat but not in guinea pig adipocytes, attention was paid to compare these models. When expressing glucose uptake as nmoles of 2-deoxyglucose/100 mg cell lipids, maximally stimulated uptake was increased in adipocytes of WAT from treated rats but not from treated guinea pigs. However, basal hexose uptake was also increased in CL-treated rats and, as a consequence, the dose-dependent curves for insulin stimulation were similar in control and CL-treated rats when expressed as fold increase over basal. Insulin-induced lipogenesis was unchanged in rat or guinea pig adipocytes after CL-treatment. The glucose carriers GLUT4 and corresponding mRNA were increased in subcutaneous WAT or in brown adipose tissue (BAT) but not in visceral WAT or muscles of CL-treated rats. There was an increase of MAO activity in WAT and BAT, but not in liver, of CL-treated rats while no change was detected in guinea pigs. These findings show that only rat adipocytes, which are beta3-adrenergic-responsive, respond to chronic beta3-AR agonist by an increase of GLUT4 content and MAO activity, despite a desensitization of all beta-adrenoceptor subtypes.

[Non-palpable breast lesions: radio-pathologic correlations on open excisional biopsies. Significance of the choice of technique for minimal excisional biopsy]. / Lésions infracliniques mammaires: corrélations radiopathologiques sur les pièces d'exérèse chirurgicale. Intérêt pour le choix des techniques d'exérèse a minima.

OBJECTIVE: To decrease the number of open excisional breast biopsies, percutaneous breast biopsies have been developed to perform the histologic diagnosis of non-palpable breast lesions. Some techniques allow a complete removal of small radiologic lesions. To evaluate the accuracy of a pathologic analysis performed only on the radiologic findings, we studied the radiologic and histologic correlation on open excisional biopsy (OEB) specimens. The aim of our study was to determine how many carcinomas were found distant from the radiologic findings. MATERIAL AND METHODS: Non-palpable breast lesions have been excised after preoperative localization. The radiologic findings were classified in microcalcifications, masses, architectural distortion and in sonographic masses. The correlation between the radiologic and pathologic findings was studied and all the lesions incidentally discovered on histology with no correlation with the imaging findings or distant from the radiologic findings were described. One hundred and twenty-nine lesions have been evaluated in 99 patients. Radiologic findings included 79 clusters of microcalcifications, 30 masses, six architectural distortions and 14 sonographic lesions. RESULTS: The histopathological results were benign in 41.9%, malignant in 49.6% and atypical hyperplasia lesions were discovered in 8.5%. All benign lesions were correlated to radiologic findings. No malignant lesion was found at a distance. In three cases atypical hyperplasia lesions were coexistent with the radiologic findings correlated with benign lesions and in three cases they were found at a distance. All but two malignant lesions were correlated with radiologic findings. In two cases a microinvasive carcinoma and foci of labular carcinoma in situ were found coexistent with benign lesions. The subgroup of small lesions lesser than 10 mm included 31 benign lesions. A complete removal of these lesions should be obtained with percutaneous biopsies. CONCLUSION: A pathologic analysis targeted on radiologic findings is accurate. Numerous open excisional biopsies performed for benign pathology should be avoided.

Immune cells in adipose tissue: key players in metabolic disorders.

Obesity, defined as the excess development of adipose tissue, is an important risk factor for metabolic and cardiovascular diseases such as type 2 diabetes, hypertension and atherosclerosis. Over the past few years, metabolic inflammation has emerged as a major process underlying the link between obesity and its associated pathologies. Adipose tissue appears to play a primary and crucial role as a source and site of inflammation. Accumulation of immune cells within adipose tissue occurs in obese conditions. The present review focuses on the relationship between adipose tissue and immune cells, including macrophages, dendritic cells, T and B lymphocytes, and natural killer cells, in both the physiological state and under obese conditions. The factors involved in the accumulation of both myeloid and lymphoid cells in adipose tissue are also described. In addition, the role of adipose-tissue immune cells on adipocyte metabolism and cells of the adipose tissue stromal-vascular fraction are discussed, with particular emphasis on the cross-talk between macrophages and adipocytes, together with recent reports of T lymphocytes in adipose tissue.