The thyroid receptor ß modulator GC-1 reduces atherosclerosis in ApoE deficient mice.

Thyroid hormone reduces plasma cholesterol and increases expression of low-density lipoprotein receptor (LDL-R) in liver, an effect mediated by thyroid receptor ß (TRß). The selective TRß modulator GC-1 also enhances several steps in reverse cholesterol transport and can decrease serum cholesterol independently of LDL-R. To test whether GC-1 reduces atherosclerosis and to determine which mechanisms are active, we treated ApoE deficient mice with atherogenic diet ± GC-1. GC-1 reduced cholesteryl esters in aorta after 20 weeks. Serum free and esterified cholesterol were reduced after 1 and 10 weeks, but not 20 weeks. Hepatic bile acid synthesis and LDL-R expression was elevated after 1, 10 and 20 weeks, without changes in hepatic de novo cholesterol synthesis. GC-1 increased faecal neutral sterols and reduced serum campesterol after 1 week, indicating reduced intestinal cholesterol absorption. After 20 weeks, GC-1 increased faecal bile acids, but not faecal neutral sterols. Hepatic scavenger receptor B1 (SR-B1) expression was decreased by GC-1. We conclude that GC-1 delays the onset of atherosclerosis in ApoE deficient mice. Since ApoE is needed for hepatic cholesterol reabsorption by LDL-R, this supports the idea that GC-1 reduces serum cholesterol independently of LDL-R by increasing hepatic bile acid synthesis. GC-1 lipid-lowering effects in ApoE deficient mice may also be partly due to reduced intestinal cholesterol absorption. Since reductions in serum cholesterol are reversed at longer times, these GC-1 dependent effects may not be enough for sustained cholesterol reduction in long term treatments.

Acute in vivo effects of insulin on gene expression in adipose tissue in insulin-resistant and insulin-sensitive subjects.

AIMS/HYPOTHESIS: We determined the response of selected genes to in vivo insulin in adipose tissue in 21 non-diabetic women. MATERIALS AND METHODS: The women were divided into insulin-sensitive and -resistant groups based on their median whole-body insulin sensitivity (8.7+/-0.4 vs 4.2+/-0.3 mg kg(-1) min(-1) for insulin-sensitive vs -resistant group). Subcutaneous adipose tissue biopsies were obtained before and after 3 and 6 h of i.v. maintained euglycaemic hyperinsulinaemia. Adipose tissue mRNA concentrations of facilitated glucose transporter, member 1 (SLC2A1, previously known as GLUT1), facilitated glucose transporter, member 4 (SLC2A4, previously known as GLUT4), peroxisome proliferator-activated receptor gamma ( PPARG), peroxisome proliferator-activated receptor gamma co-activator 1alpha (PPARGC1A), 11beta-hydroxysteroid dehydrogenase-1 (HSD11B1), TNF, adiponectin (ADIPOQ), IL6 and the macrophage marker CD68 were measured using real-time PCR. RESULTS: Basal expression of 'insulin-sensitivity genes' SLC2A4 and ADIPOQ was lower while that of 'insulin-resistance genes', HSD11B1 and IL6 was significantly higher in the insulin-resistant than in the insulin-sensitive group. Insulin significantly increased expression of 'insulin-sensitivity genes' SLC2A4, PPARG, PPARGC1A and ADIPOQ in the insulin-sensitive group, while only expression of PPARG and PPARGC1A was increased in the insulin-resistant group. The expression of 'insulin-resistance genes' HSD11B1 and IL6 was increased by insulin in the insulin-resistant group, but insulin failed to increase HSD11B1 expression in the insulin-sensitive group. At 6 h, expression of HSD11B1, TNF and IL6 was significantly higher in the insulin-resistant than in the insulin-sensitive group. IL6 expression increased significantly more in response to insulin in the insulin-resistant than in the insulin-sensitive group. CD68 was overexpressed in the insulin-resistant as compared with the insulin-sensitive group at both 0 and 6 h. CONCLUSIONS/INTERPRETATION: These data suggest that genes adversely affecting insulin sensitivity hyperrespond to insulin, while genes enhancing insulin sensitivity hyporespond to insulin in insulin-resistant human adipose tissue in vivo.

Enhanced insulin-stimulated glycogen synthesis in response to insulin, metformin or rosiglitazone is associated with increased mRNA expression of GLUT4 and peroxisomal proliferator activator receptor gamma co-activator 1.

AIMS/HYPOTHESIS: The aim of this study was to determine the effect of several antidiabetic agents on insulin-stimulated glycogen synthesis, as well as on mRNA expression. METHODS: Cultured primary human skeletal myotubes obtained from six healthy subjects were treated for 4 or 8 days without or with glucose (25 mmol/l), insulin (400 pmol/l), rosiglitazone (10 micromol/l), metformin (20 micromol/l) or the AMP-activated kinase activator 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR) (200 micromol/l). After this, insulin-stimulated glycogen synthesis was determined. mRNA levels of the glucose transporters GLUT1 and GLUT4, the peroxisomal proliferator activator receptor gamma (PPAR gamma) co-activator 1 (PGC1) and the myocyte-specific enhancer factors (MEF2), MEF2A, MEF2C and MEF2D were determined using real-time PCR analysis after 8 days exposure to the various antidiabetic agents. RESULTS: Insulin-stimulated glycogen synthesis was significantly increased in cultured human myotubes treated with insulin, rosiglitazone or metformin for 8 days, compared with non-treated cells. Furthermore, an 8-day exposure of myotubes to 25 mmol/l glucose impaired insulin-stimulated glycogen synthesis. In contrast, treatment with AICAR was without effect on insulin-mediated glycogen synthesis. Exposure to insulin, rosiglitazone or metformin increased mRNA expression of PGC1 and GLUT4, while AICAR or 25 mmol/l glucose treatment increased GLUT1 mRNA expression. Metformin also increased mRNA expression of the MEF2 isoforms. CONCLUSIONS/INTERPRETATION: Enhanced insulin-stimulated glycogen synthesis in human skeletal muscle cell culture coincides with increased GLUT4 and PGC1 mRNA expression following treatment with various antidiabetic agents. These data show that chronic treatment of human myotubes with insulin, metformin or rosiglitazone has a direct positive effect on insulin action and mRNA expression.

In the lipodystrophy associated with highly active antiretroviral therapy, pseudo-Cushing's syndrome is associated with increased regeneration of cortisol by 11beta-hydroxysteroid dehydrogenase type 1 in adipose tissue.

AIMS/HYPOTHESIS: Highly active antiretroviral therapy (HAART) in patients infected with human immunodeficiency virus (HIV) is associated with a poorly understood lipodystrophic and hypertriglyceridaemic syndrome, which resembles Cushing's syndrome, but in which plasma cortisol is not elevated. We tested the hypothesis that this HAART-associated lipodystrophy is explained by increased local regeneration of cortisol from inactive cortisone within adipose tissue, catalysed by the enzyme 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1). METHODS: In this cross-sectional study, a previously described cohort of 30 HIV-infected patients with lipodystrophy were compared with 13 HIV-infected patients without lipodystrophy. Intra-abdominal and subcutaneous adipose tissue were quantified using magnetic resonance imaging. Gene expression in subcutaneous fat was measured using real-time PCR. Urine cortisol and its metabolites were analysed by gas chromatography/mass spectrometry. RESULTS: Patients with lipodystrophy had significantly higher 11beta-HSD1 mRNA concentrations (relative to beta2-microglobulin mRNA) in subcutaneous adipose tissue than non-lipodystrophic patients (0.29+/-0.20 vs 0.09+/-0.07, p=0.0004) and higher ratios of urinary cortisol : cortisone metabolites. Adipose tissue 11beta-HSD1 mRNA correlated with multiple features of insulin resistance and with mRNA concentrations for glucocorticoid receptor and angiotensinogen. CONCLUSIONS/INTERPRETATION: In adipose tissue of patients with HAART-associated lipodystrophy, 11beta-HSD1 mRNA is increased and its concentration is correlated with features of insulin resistance. We suggest that increased adipose tissue 11beta-HSD1 may explain the pseudo-Cushing's features in patients with HAART-associated lipodystrophy, and is a potential therapeutic target.

Insulin action in cultured human skeletal muscle cells during differentiation: assessment of cell surface GLUT4 and GLUT1 content.

In mature human skeletal muscle, insulin-stimulated glucose transport is mediated primarily via the GLUT4 glucose transporter. However, in contrast to mature skeletal muscle, cultured muscle expresses significant levels of the GLUT1 glucose transporter. To assess the relative contribution of these two glucose transporters, we used a novel photolabelling techniques to assess the cell surface abundance of GLUT1 and GLUT4 specifically in primary cultures of human skeletal muscle. We demonstrate that insulin-stimulated glucose transport in cultured human skeletal muscle is mediated by GLUT4, as no effect on GLUT1 appearance at the plasma membrane was noted. Furthermore, GLUT4 mRNA and protein increased twofold (p < 0.05), after differentiation, whereas GLUT1 mRNA and protein decreased 55% (p < 0.005). Incubation of differentiated human skeletal muscle cells with a non-peptide insulin mimetic significantly (p < 0.05) increased glucose uptake and glycogen synthesis. Thus, cultured myotubes are a useful tool to facilitate biological and molecular validation of novel pharmacological agents aimed to improve glucose metabolism in skeletal muscle.

Characterization of the human peroxisome proliferator activated receptor delta gene and its expression.

Peroxisome proliferator activated receptors (PPARs) are nuclear receptors regulating the expression of genes involved in lipid and glucose metabolism. Three different PPARs; alpha (PPARA), gamma (PPARG) and delta (PPARD) have been characterized and they are distinguished from each other by tissue distribution and cell activation. In this study, the structure and detailed chromosomal localization of the human PPARD gene was determined. Three genomic clones containing the PPARD gene was isolated from a human P1 library. The gene spans approximately 85 kb of DNA and consists of 9 exons and 8 introns with exons ranging in size from 84 bp to 2.3 kb and introns ranging from 180 bp to 50 kb. All splice acceptor and donor sites conform to the consensus sequences including the AG-GT motif. Although PPARD lacks a TATA box, the gene is transcribed from a unique start site located 380 bp upstream of the ATG initiation codon. The 5' and 3' ends were mapped by rapid amplification of cDNA ends and the mRNA size of PPARD based upon the structure of the gene is 3803 bp. In addition, the chromosomal sublocalization of PPARD was determined by radiation hybrid mapping. The PPARD gene is located at 14 cR from the colipase gene and 15 cR from the serine kinase gene at chromosomal region 6p21.2.

Pivmecillinam treatment in acute cystitis. Three versus seven days study.

In an open randomized study pivmecillinam (Selexid; CAS 32886-97-8) was studied by general practitioners in 345 female patients with uncomplicated acute cystitis. Out of the bacteriologically evaluated 299 patients 151 patients were treated for three days with two tablets of pivmecillinam 200 mg t.i.d. and 148 patients for seven days with one tablet t.i.d. There were no significant differences in the bacteriological effect between the two regimens. In the 3-day group 91% and 88% were cured at the first and the second control; in the 7-day group 94% and 95%, respectively. There was no significant difference in the total clinical effect, either. Adverse reactions, usually gastrointestinal disturbances, occurred in 10% of the 3-day group and in 11% of the 7-day group (N.S.). Pivmecillinam treatment in acute cystitis in women was equally effective whether given for three or seven days, with the same total frequency of adverse reactions for the two regimens.

The prevention of headache following spinal anaesthesia.

The efficacy of various methods in preventing headache following spinal anaesthesia was compared in 797 patients. The postspinal headache occurred in 17.8% of the patients in whom the lumbar puncture was done with a 22-gauge needle. The use of a 26-gauge needle reduced the occurrence of the headache to 7.8% (p less than 0.0125) and the administration of 100 mg of indomethacin six hours after the blockade to 10.3% (p less than 0.05) of the patients. The hydration, an infusion of 3000 ml of fluids during the operation day as compared to that of 1500 ml, did not prevent the headache, nor did the recumbency of 24 hours as compared to that of 8-16 hours, nor the prophylactic epidural blood patching. The headache occurred more often in young patients and in patients who had a history of repeating headache or migraine. In the patients with postspinal headache indomethacin relieved pain as effectively as a stronger analgesic-mixture. Other complaints occurring after the blockade were: pain in the lower back in 9.7% and pain in the lower extremities in 7.2% of the patients. The lithotomy position during the blockade predisposed the patients to these complications.

[The subclavian vein catheter related infections (author's transl)]. / Les complications infectieuses du cathétérisme de la veine sous-clavière.

The aim of the present investigation was to study the possible means to prevent the subclavian vein catheter related infections. The tip of the catheter and the part situating at the skin puncture were cultured using the semiquantitative culture method. The growth of the micro-organisms was divided into three groups: classical pathogenic, opportunistic and non pathogenic. We did not find any growth in 64 p. cent of the catheters. The puncture site gave growth in 15 p. cent, the catheter tip in 6,5 p. cent and both of them in 14 p. cent In this study four cases (1,5 p. cent) of septicemias were found. In these cases Streptococcus fecalis was the most common microorganism. The aim of the semiquantitative culture method was to differentiate a real catheter related infection and contamination. The real infection was found only in 32 catheter tips though growth was seen in 54 catheter tips. According to this investigation it seems that the most important factor in preventing catheter related infections was strict sterility during the catheter placement as well as during the maintenance. A small dose of heparin probably reduces the formation of fibrin sleeve around the catheter tip and thus prevents infections. The time the patient is catheterized is also of importance, patients with catheter related septicemia had twice as long duration than cases without growth of catheter tip.