We sought evidence for pulsatility of lipolysis in human subcutaneous adipose tissue in vivo. Arterialized and adipose tissue venous blood samples were drawn at 2-min intervals from nine healthy subjects. This procedure was repeated during hyperinsulinemic-euglycemic clamp to remove insulin pulsatility. We found evidence for pulsatile release of both nonesterified fatty acids (NEFAs) (seven of nine subjects) and glycerol (five of six subjects) with a period of ϳ12-14 min. This pulsatility was maintained even during the hyperinsulinemic clamp. Checks were made for spurious pulse detection, including the creation of "mock" venoarterialized differences by subtracting one subject's arterialized concentrations from another's venous; the peaks detected were less consistent in character than with real data (peak width, P ؍ 0.006; peak interval, P < 0.004). Significant cross-correlations between NEFA and glycerol release also provided evidence of a real effect. Arterialized norepinephrine concentrations were also pulsatile, but the period did not match that of NEFA and glycerol release. Insulin concentrations were pulsatile with a typical period of 12 min, but this was not significantly cross-correlated with lipolysis. We conclude that release from adipose tissue of the products of lipolysis is pulsatile in humans. Diabetes 54:1297-1303, 2005 I t is increasingly recognized that metabolic processes do not operate at steady rates. Oscillations in glycolytic flux, synchronized across cells, have long been recognized (1). Pulsatile secretion of hormones is also well established, and for insulin, for example, there is a clear oscillatory pattern with a characteristic period of 12-13 min observable in systemic plasma (2,3). Among the metabolic processes regulated by insulin is adipose tissue lipolysis. Recently, rapid oscillations in lipolysis have been observed in omental adipose tissue in dogs (4). These oscillations appeared to be independent of insulin, however, and were partially blocked by propranolol. More recent work in dogs has shown that oscillations of lipolysis, detected in systemic plasma nonesterified fatty acid (NEFA) concentrations, are superimposed on a steady background level of NEFA, and only the oscillatory component is blocked by specific blockade of the 3-adrenoceptor, which is responsible for lipolysis in dogs (5).In humans, adipose tissue lipolysis, as measured by microdialysis of interstitial glycerol, is not affected by propranolol after an overnight fast. (6). This seems surprising but might be understandable if -adrenergic activation were responsible for only a small component of lipolysis; rapid oscillations might be lost with the limited time resolution of microdialysis. If pulsatile lipolysis were detectable in humans, it might considerably alter our view of NEFA release and its interaction with insulin action and glucose metabolism.Therefore, we have sought evidence for pulsatility of lipolysis in human adipose tissue. The subcutaneous upper-body adipose tissue makes the largest contributio...
Summary A 40-year-old woman was hospitalised at 25-week gestation following a diagnosis of severe symptomatic hypercalcaemia (adjusted serum calcium 3.02 mmol/L). A diagnosis of primary hyperparathyroidism (PHP) was made on the basis of elevated parathyroid hormone (PTH) 11.2 pmol/L (reference range 1.5–6.9) and exclusion of familial hypocalciuric hypercalcaemia. Ultrasound examination of the neck did not convincingly demonstrate an abnormal or enlarged parathyroid gland and parathyroid scintigraphy was not performed due to maternal choice relating to perceived radiation risk to the foetus. At neck exploration during the 28th week of pregnancy a right lower pole parathyroid lesion was excised together with two abnormal lymph nodes (largest 1.6 cm). Histology confirmed a parathyroid adenoma and also papillary thyroid carcinoma deposits in the two resected lymph nodes. Post-operatively, levels of adjusted serum calcium normalised and pregnancy progressed uneventfully to term. Total thyroidectomy was performed 2 weeks after delivery revealing two small foci of papillary micro-carcinoma (largest 2.3 mm, one in each thyroid lobe) with no evidence of further metastatic tumour in lymph nodes removed during functional neck dissection. Radioiodine remnant ablation (RRA) was performed 2 months post thyroidectomy to allow for breast involution. The patient remains in full clinical and biochemical remission 9 years later. We present and review the difficult management decisions faced in relation to the investigation and treatment of PHP in pregnancy, further complicated by incidentally discovered locally metastatic pT1aN1aM0 papillary thyroid carcinoma. Learning points: PHP may have serious consequences during pregnancy and usually requires surgical management during pregnancy to reduce the risk of maternal and foetal complications. The indications for and optimal timing of surgical management are discussed. Localisation by parathyroid scintigraphy is controversial during pregnancy: modified dose regimes may be considered in preference as an alternative to unguided neck exploration. Breastfeeding is contraindicated for 6–8 weeks before radioactive-iodine remnant ablation (RRA) to prevent increased breast uptake. Breastfeeding is further contra-indicated until after a subsequent pregnancy. Incidentally discovered differentiated thyroid carcinoma (DTC) in cervical lymph nodes in some cases may be managed expectantly because in one quarter of thyroidectomies the primary tumour remains occult.
Administration of BCG by various dosage schedules suppressed adjuvant disease in rats. BCG administration produced an initial increase, followed by a depression, of the phytohemagglutinin response of purified blood lymphocytes. An increase in absolute and relative numbers of bursa-equivalent (B)-cells followed BCG administration, concurrent with a decrease in the phytohemagglutinin responsiveness. With adjuvant alone, there was a diminution in phytohemagglutinin response and an increase in number of B-cells; the latter occurred immediately after adjuvant injection and also when the generalized disease appeared. When both BCG and adjvant were present, parallel increases of phytohemagglutinin responsiveness and B-cell numbers resulted. The pattern of tissue localization of radioactively labeled thoracic duct cells from normal or BCG-treated donors given to normal, BCG-treated, adjuvant-injected, and BCG-treated + adjuvant-injected syngeneic recipients indicated significantly greater homing to the thymus and decreased localization to the bone marrow when BCG had been given to either donors or recipients. When labeled thymus cells were used, only the decreased bone marrow localization was noted. These observations suggest that the suppressive effect of BCG may be mediated through modification of the lymphocyte recirculation pattern, possibly resulting from alterations in lymphocyte recognition sites.
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