Mechanisms of liver and muscle insulin resistance induced by chronic high-fat feeding

To elucidate cellular mechanisms of insulin resistance induced by excess dietary fat, we studied conscious chronically high-fat-fed (HFF) and control chow diet-fed rats during euglycemic-hyperinsulinemic (560 pmol/l plasma insulin) clamps. Compared with chow diet feeding, fat feeding significantly impaired insulin action (reduced whole body glucose disposal rate, reduced skeletal muscle glucose metabolism, and decreased insulin suppressibility of hepatic glucose production [HGP]). In HFF rats, hyperinsulinemia significantly suppressed circulating free fatty acids but not the intracellular availability of fatty acid in skeletal muscle (long chain fatty acyl-CoA esters remained at 230% above control levels). In HFF animals, acute blockade of beta-oxidation using etomoxir increased insulin-stimulated muscle glucose uptake, via a selective increase in the component directed to glycolysis, but did not reverse the defect in net glycogen synthesis or glycogen synthase. In clamp HFF animals, etomoxir did not significantly alter the reduced ability of insulin to suppress HGP, but induced substantial depletion of hepatic glycogen content. This implied that gluconeogenesis was reduced by inhibition of hepatic fatty acid oxidation and that an alternative mechanism was involved in the elevated HGP in HFF rats. Evidence was then obtained suggesting that this involves a reduction in hepatic glucokinase (GK) activity and an inability of insulin to acutely lower glucose-6-phosphatase (G-6-Pase) activity. Overall, a 76% increase in the activity ratio G-6-Pase/GK was observed, which would favor net hepatic glucose release and elevated HGP in HFF rats. Thus in the insulin-resistant HFF rat 1) acute hyperinsulinemia fails to quench elevated muscle and liver lipid availability, 2) elevated lipid oxidation opposes insulin stimulation of muscle glucose oxidation (perhaps via the glucose-fatty acid cycle) and suppression of hepatic gluconeogenesis, and 3) mechanisms of impaired insulin-stimulated glucose storage and HGP suppressibility are not dependent on concomitant lipid oxidation; in the case of HGP we provide evidence for pivotal involvement of G-6-Pase and GK in the regulation of HGP by insulin, independent of the glucose source.     

Leucocyte-migration inhibition induced by uveoretinal antigen in patients with diabetic retinopathy

Leucocyte-migration inhibition was to determine the state of hypersensitivity in 65 diabetic patients with different stages of retinopathy and 21 nondiabetic controls. About one third of the patients with simple or proliferative retinopathy exhibited significant leucocyte-migration inhibition of 0.2 mg/ml. protein concentration of uvreoretinal antigen. In contrast, only one of 15 patients with minimal retinopathy and none of the controls showed significant leucocyte-migration inhibition. Corneal and lenticular antigens did not evoke a cellular immune response in any of the tested individuals. These findings suggest that cell-mediated hypersensitivity to uveoretinal antigen may develop in diabetic patients with prolonged, progressive, simple or proliferative retinopathy.     

Heat pipes with header and artery systemsCaloducs avec des systemes de pilotage et d'irrigationWärmerohre mit verteiler- und arterien-systemenTeплoвыe тpyбы, имeyщиe cиcтeмы кoллeктop-apтepия

A novel form of artery and header system for use in heat pipes is described, then thermal/hydraulic design procedures developed. The artery system is simple and robust, and self-priming without the use of capillary arteries. Operation with single-phase fluids in the artery, when acting against gravity, is discussed. When in this orientation the axial load can exceed that in the horizontal plane, and be more than ten-fold the unit without an artery.     

Sarcoidosis with salivary gland involvement: biochemical studies on parotid saliva

Parotid saliva from a patient suffering from sarcoidosis with salivary gland involvement has been shown to have a decreased level of alpha-amylase but increased levels of albumin and lysozyme. These observations suggest that in addition to impaired gland function, gland damage as a result of inflammation had occurred which permitted increased passage of constituents from serum into the gland secretion.     

Regulation of the immune system by synthetic polynucleotides. VI. Amplification of the immune response in young and aging mice

Model systems for study of the action of adjuvants in immunodeficient states were developed in 10- to 14-day-old BALB/aj mice and aging BALB/aj mice (12 to 16 months). With sheep red blood cells as antigen polyadenylicpolyuridylic acid complexes (poly A:U) were found to be stimulatory in both the neonatal and aging mice. The effect of poly A:U was similar to that seen when 5 X 10(6) thymocytes from immunologically mature mice were given with antigen. Cell-free supernatant fluids induced by incubation of poly A:U with thymocytes likewise were capable of restoring the number of antibody-forming cells to normalcy in aging mice.     

Hypertension--the fledgling of modern medical practice

The treatment of hypertension was discovered long before the mechanisms of the disease became known. Only recently has it been appreciated that blood pressure is controlled physiologically in many ways. Hypertension has suddenly achieved celebrity status. It is now recognized as the second leading cause of death in the United States. New programs have made the public aware of it and have prompted many individuals to have their blood pressure checked. Office diagnostic measures usually suffice to determine the presence of the disease. Treatment should generally be initiated with a slow-acting diuretic or with propranolol; other drugs may be added later. Treatment is a lifelong undertaking, and engaging the patient as a partner in the venture by means of home blood pressure measurements and an educational program contributes to its success. Treatment of hypertension is the first step in the prophylaxis of atherosclerosis.     

Women's attitudes to mastectomy for breast cancer

One hundred patients who had been subjected to mastectomy for carcinoma were interviewed retrospectively to gauge their attitudes to any physical and/or emotional disabilities relating to their operation or disease. It was found that 40% of the patients had delayed for longer than a month after the onset of symptoms before seeking medical advice, but the reasons for this were not readily forthcoming. However, fear of mastectomy was not a common cause. Anxiety and embarassment due to an absent breast occurred in about one-third of patients, and did not diminish with time. Knowledge and the use of mammary prostheses was far from universal, and disturbingly only two-thirds were counselled in these matters by their medical advisers. Physical complications were common, particularly lymphoedema of the arm, and as expected this was closely related to the type and extent of treatment undertaken.     

Family planning opinion leadership in Korea, 1971

The characteristics of Korean family planning opinion leaders are assessed through a secondary analysis of the 1971 national survey conducted by the Korean Institute for Research in the Behavioral Sciences. In effect, what characterized Korean family planning opinion leaders was a rather national and democratic model. Those who had tried methods, discussed them, and knew a lot about them assumed leadership roles more than others. Place of residence, education, and other such variables mattered relatively little unless a woman had credibility imparted by actual use and knowledge imparted by use or discussions with family planning professionals.