Muscle Lipid Oxidation Is Not Affected by Obstructive Sleep Apnea in Diabetes and Healthy Subjects.

The molecular mechanisms linking obstructive sleep apnea (OSA) with type 2 diabetes mellitus (T2DM) remain unclear. This study investigated the effect of OSA on skeletal muscle lipid oxidation in nondiabetic controls and in type 2 diabetes (T2DM) patients. Forty-four participants matched for age and adiposity were enrolled: nondiabetic controls (control, n = 14), nondiabetic patients with severe OSA (OSA, n = 9), T2DM patients with no OSA (T2DM, n = 10), and T2DM patients with severe OSA (T2DM + OSA, n = 11). A skeletal muscle biopsy was performed; gene and protein expressions were determined and lipid oxidation was analyzed. An intravenous glucose tolerance test was performed to investigate glucose homeostasis. No differences in lipid oxidation (178.2 ± 57.1, 161.7 ± 22.4, 169.3 ± 50.9, and 140.0 ± 24.1 pmol/min/mg for control, OSA, T2DM, and T2DM+OSA, respectively; p > 0.05) or gene and protein expressions were observed between the groups. The disposition index, acute insulin response to glucose, insulin resistance, plasma insulin, glucose, and HBA1C progressively worsened in the following order: control, OSA, T2DM, and T2DM + OSA (p for trend <0.05). No association was observed between the muscle lipid oxidation and the glucose metabolism variables. We conclude that severe OSA is not associated with reduced muscle lipid oxidation and that metabolic derangements in OSA are not mediated through impaired muscle lipid oxidation.

The impact of iron coagulant on the behavior and biochemistry of freshwater mussels Anodonta cygnea and Unio tumidus during lake restoration.

Iron (Fe) treatment is one of the most commonly used methods to restore eutrophic lakes and reservoirs. The Fe-based coagulants dosage results in an almost immediate improvement in water quality at a relatively low cost. However, the effects of the application of coagulants are not always predictable, and the scale of the risks is not fully understood. The dosage of coagulants changes the chemical and physical properties of water, thereby affecting aquatic biocenoses. In this study, several laboratory experiments were conducted to evaluate the effects of Fe-based coagulant dosage on two bivalves species: Anodonta anatina and Unio tumidus. Their ability to efficiently filter water and reduce seston makes them a key component of aquatic ecosystems in terms of maintaining proper ecological health and stable functioning. Behavioral response, biochemical parameters, and body chemistry changes in mussels exposed to different doses of coagulant were surveyed. A dose-dependent reduction in filtration activity of both species was observed. As early as 10 g Fe m2 (which is a moderate dose used in lakes restoration), mussels of both species almost completely reduced their filtration activity and remained with closed valves for several subsequent days. Significant Fe accumulation in muscles of bivalves exposed to coagulant was also observed. This was particularly the case when very high doses of coagulant were applied. Then, the iron content in leg muscles of both species increased over fourfold. At the same time, a decrease in muscles calcium and phosphorus content was observed. No symptoms of oxidative stress (TBARS, H2O2) after mussels exposure to coagulants were found. The results suggest that the application of Fe-based coagulant for water ecosystem restoration may be a threat to the mussels population. These findings are significant for decisions on the selection of restoration methods for a specific lake.

Visceral Fat Accumulation Is Related to Impaired Pancreatic Blood Perfusion and Beta-Cell Dysfunction in Obese Women.

AIMS/HYPOTHESIS: Beta-cell failure plays a fundamental role in type 2 diabetes mellitus (T2DM) development. It has been shown that the beta-cells are among the most sensitive to hypoxia. We aimed to analyze whether decrease in pancreatic perfusion relates to 1/decline in beta-cell function and 2/visceral fat accumulation in patients with T2DM. METHODS: Fifteen women with T2DM on metformin therapy alone and fifteen women of comparable age and BMI without prediabetes/diabetes were cross-sectionally examined: clinical and anthropometric examination, fast sampled intravenous glucose tolerance test (FSIVGTT), dynamic contrast-enhanced magnetic resonance imaging to assess pancreatic perfusion (area under the curve of postcontrast saturation, AUCTSIC), and visceral adiposity (VAT, calculated from transverse sections at the level L2-L5 vertebrae). RESULTS: Pancreatic blood perfusion (AUCTSIC) did not differ between groups (p = 0.273), but it negatively correlated with BMI (r = -0.434, p = 0.017), WHR (r = -0.411, p = 0.024), and VAT (r = -0.436, p = 0.016) in both groups. Moreover, AUCTSIC in the head of the pancreas negatively correlated with the level of fasting glycemia (r = -0.401, p = 0.028) and HOMA-IR (r = -0.376, p = 0.041). DISCUSSION/CONCLUSION: We showed that decreased pancreatic perfusion did not relate to beta-cell dysfunction in early stages of T2DM development, but it was related to VAT, insulin resistance, and higher fasting glycemia. Furthermore, lower pancreatic perfusion was related to VAT, insulin resistance, and higher fasting glycemia.

Hypoxia Modulates Effects of Fatty Acids on NES2Y Human Pancreatic ß-cells.

Saturated fatty acids (FAs) induce apoptosis in the human pancreatic NES2Y ß-cell line while unsaturated FAs have nearly no detrimental effect. Moreover, unsaturated FAs are capable of inhibiting the pro-apoptotic effect of saturated FAs. Hypoxia is also known to have deleterious effects on ß-cells function and viability. In the present study, we have tested the modulatory effect of hypoxia on the effect of FAs on the growth and viability of the human pancreatic NES2Y ß-cells. This study represents the first study testing hypoxia effect on effects of FAs in pancreatic ß-cells as well as in other cell types. We showed that hypoxia increased the pro-apoptotic effect of saturated stearic acid (SA). Endoplasmic reticulum stress signaling seemed to be involved while redistribution of FA transporters fatty acid translocase/cluster of differentiation 36 (FAT/CD36) and fatty acid-binding protein (FABP) do not seem to be involved in this effect. Hypoxia also strongly decreased the protective effect of unsaturated oleic acid (OA) against the pro-apoptotic effect of SA. Thus, in the presence of hypoxia, OA was unable to save SA-treated ß-cells from apoptosis induction. Hypoxia itself had only a weak detrimental effect on NES2Y cells. Our data suggest that hypoxia could represent an important factor in pancreatic ß-cell death induced and regulated by FAs and thus in the development of type 2 diabetes mellitus.

An innovative intermittent hypoxia model for cell cultures allowing fast Po2 oscillations with minimal gas consumption.

Performing hypoxia-reoxygenation cycles in cell culture with a cycle duration accurately reflecting what occurs in obstructive sleep apnea (OSA) patients is a difficult but crucial technical challenge. Our goal was to develop a novel device to expose multiple cell culture dishes to intermittent hypoxia (IH) cycles relevant to OSA with limited gas consumption. With gas flows as low as 200 ml/min, our combination of plate holders with gas-permeable cultureware generates rapid normoxia-hypoxia cycles. Cycles alternating 1 min at 20% O2 followed by 1 min at 2% O2 resulted in Po2 values ranging from 124 to 44 mmHg. Extending hypoxic and normoxic phases to 10 min allowed Po2 variations from 120 to 25 mmHg. The volume of culture medium or the presence of cells only modestly affected the Po2 variations. In contrast, the nadir of the hypoxia phase increased when measured at different heights above the membrane. We validated the physiological relevance of this model by showing that hypoxia inducible factor-1α expression was significantly increased by IH exposure in human aortic endothelial cells, murine breast carcinoma (4T1) cells as well as in a blood-brain barrier model (2.5-, 1.5-, and 6-fold increases, respectively). In conclusion, we have established a new device to perform rapid intermittent hypoxia cycles in cell cultures, with minimal gas consumption and the possibility to expose several culture dishes simultaneously. This device will allow functional studies of the consequences of IH and deciphering of the molecular biology of IH at the cellular level using oxygen cycles that are clinically relevant to OSA.

Increased Incretin But Not Insulin Response after Oral versus Intravenous Branched Chain Amino Acids.

BACKGROUND/AIMS: Branched chain amino acids (BCAAs) are known to exert an insulinotropic effect. Whether this effect is mediated by incretins (glucagon like peptide 1 [GLP-1] or glucose-dependent insulinotropic peptide [GIP]) is not known. The aim of this study was to show whether an equivalent dose of BCAA elicits a greater insulin and incretin response when administered orally than intravenously (IV). METHODS: Eighteen healthy, male subjects participated in 3 tests: IV application of BCAA solution, oral ingestion of BCAA and placebo in an equivalent dose (30.7 ± 1.1 g). Glucose, insulin, C-peptide, glucagon, GLP-1, GIP, valine, leucine and isoleucine concentrations were measured. RESULTS: Rise in serum BCAA was achieved in both BCAA tests, with incremental areas under the curve (iAUC) being 2.1 times greater for IV BCAA compared with those of the oral BCAA test (p < 0.0001). Oral and IV BCAA induced comparable insulin response greater than placebo (240 min insulin iAUC: oral 3,411 ± 577 vs. IV 2,361 ± 384 vs. placebo 961.2 ± 175 pmol/L, p = 0.0006). Oral BCAA induced higher GLP-1 (p < 0.0001) and GIP response (p < 0.0001) compared with the IV or placebo. Glucose levels declined significantly (p < 0.001) in the same pattern during both BCAA tests with no change in the placebo group. CONCLUSIONS: An equivalent dose of BCAA elicited a comparable insulin and greater incretin response when administered orally and not when administered through IV. We conclude that insulinotropic effects of BCAA are partially incretin dependent.

Inhibition of Lipolysis Ameliorates Diabetic Phenotype in a Mouse Model of Obstructive Sleep Apnea.

Obstructive sleep apnea (OSA) is associated with insulin resistance, glucose intolerance, and type 2 diabetes. Causal mechanisms mediating this association are not well defined; however, augmented lipolysis in adipose might be involved. Here, we investigated the effect of acipimox treatment (lipolysis inhibitor) on glucose tolerance and insulin sensitivity in mice exposed to intermittent hypoxia (IH). C57BL6/J mice were exposed for 14 days to IH or control conditions. IH was created by decreasing the fraction of inspired oxygen from 20.9 to 6.5%, 60 times/h. Control exposure was air (fraction of inspired oxygen, 20.9%) delivered at an identical flow rate. Acipimox was provided in drinking water (0.5 g/ml) during exposures. After exposures, intraperitoneal insulin (0.5 IU/kg) and glucose (1 g/kg) tolerance tests were performed, and primary adipocytes were isolated for lipolysis experiments. IH elevated fasting glucose by 51% and worsened glucose tolerance and insulin sensitivity by 33 and 102%, respectively. In parallel, IH increased spontaneous lipolysis by 264%, and reduced epididymal fat mass by 15% and adipocyte size by 8%. Acipimox treatment prevented IH-induced lipolysis and increased epididymal fat mass and adipocyte size by 19 and 10%, respectively. Acipimox fully prevented IH-induced impairments in fasting glycemia, glucose tolerance, and insulin sensitivity. For all reported results, P less than 0.05 was considered significant. Augmented lipolysis contributes to insulin resistance and glucose intolerance observed in mice exposed to IH. Acipimox treatment ameliorated the metabolic consequences of IH and might represent a novel treatment option for patients with obstructive sleep apnea.

Adipogenesis, lipogenesis and lipolysis is stimulated by mild but not severe hypoxia in 3T3-L1 cells.

In-vitro investigation of the effects of hypoxia is limited by physical laws of gas diffusion and cellular O2 consumption, making prolonged exposures to stable O2 concentrations impossible. Using a gas-permeable cultureware, chronic effects of mild and severe hypoxia on triglyceride accumulation, lipid droplet size distribution, spontaneous lipolysis and gene expression of adipocyte-specific markers were assessed. 3T3-L1 cells were differentiated under 20%, 4% or 1% O2 using a gas-permeable cultureware. Triglyceride accumulation, expression of genes characteristic for advanced adipocyte differentiation and involvement of key lipogenesis enzymes were assessed after exposures. Lipogenesis increased by 375% under mild hypoxia, but dropped by 43% in severe hypoxia. Mild, but not severe, hypoxia increased formation of large lipid droplets 6.4 fold and strongly induced gene expression of adipocyte-specific markers. Spontaneous lipolysis increased by 488% in mild, but only by 135% in severe hypoxia. Inhibition of ATP-dependent citrate lyase suppressed hypoxia-induced lipogenesis by 81% and 85%. Activation of HIF inhibited lipogenesis by 59%. Mild, but not severe, hypoxia stimulates lipolysis and promotes adipocyte differentiation, probably through excess of acetyl-CoA originating from tricarboxylic acid cycle independently of HIF activation.

[Obstructive sleep apnoea and type 2 diabetes mellitus]. / Obstrukcní spánková apnoe a diabetes mellitus 2. typu.

Obstructive sleep apnoea syndrome (OSA) is a disease very frequently occurring in people with type 2 diabetes, that significantly increases cardiovascular morbidity and mortality. In a number of studies, OSA has been identified as an independent risk factor for the development of insulin resistance, glucose intolerance and type 2 diabetes mellitus. Disorders of glucose homeostasis in patients with OSA are probably mediated by chronic intermittent hypoxia and/or sleep fragmentation through activation of the sympathetic nervous system, the hypothalamic-pituitary-adrenal stress axis, pro-inflammatory paths or oxidative stress. Despite the high prevalence of OSA among patients with type 2 diabetes as well as the proven benefit of the continuous positive airway pressure (CPAP) therapy on reduction of mortality, most patients with OSA remain undiagnosed. Active OSA screening should therefore be performed in all patients with type 2 diabetes, ideally through home monitoring of oxygen saturation and breathing during sleep. Although the effect of CPAP therapy on the improvement in diabetes control (decrease in glycated hemoglobin) has not been clearly proven in patients with type 2 diabetes so far, promising outcomes have been observed during the treatment of patients with prediabetes.Key words: CPAP - diabetes mellitus - glycemic control - intermittent hypoxia - obstructive sleep apnoea - screening - sleep fragmentation.

[Changes in nutritional recommendations for a healthy population and their influence on a diabetic diet]. / Posuny v nutricních doporuceních pro zdravé obyvatelstvo a jejich dopad pro diabetickou dietu.

UNLABELLED: Recently, thousands of papers brought knowledge about effects of nutrients on cellular level, in experimental animals and in human experiments on one side, the results of epidemiological studies on the other side have suggested the nutrients and foods for healthy diet and nutrients and foods, which should be consumed only in limited amount. Among foods, which should be avoided, those with higher content of trans-fatty acids. Their daily intake should not exceed 1 % of total energy intake. Similar should be limited saturated fatty acid, added sugar and salt. On the contrary, the intake of monounsaturated and polyunsaturated fatty acids in foods should be basic part of fat intake. In these conditions the amount of consumed fat could create up to 35 % of all daily energy intake. Beneficial carbohydrates are those with low glycemic index, i.e. whole grain and brown rice products and legumes. The intake of salt is necessary to limit fewer than 6 g per day and alcohol intake should not exceed 10 g per day in women and 20 g per day in men. The recommendation in last years do not limit cholesterol daily intake. The food of animal origin with high content of saturated fatty acids, i.e. meat and milk products parallel contains also cholesterol. On the other hand, the oils of vegetable origin mostly from tropical oils, which contents high amount of saturated fatty acids represents the risk? On the contrary eggs and shellfish contents high amount of cholesterol and very low amounts of saturated fatty acids. Therefore, there is no reason for their strict limitation in the diet. KEY WORDS: carbohydrate - diabetes - dietary recommendation - energy intake - fat - healthy diet - iron - cholesterol - protein.

[Motor vehicle driving and diabetes mellitus - medical aspects]. / Rízení motorových vozidel a diabetes mellitus - lékarské aspekty.

Diabetes mellitus is a disease which may affect the eligibility to hold a driving license and increase the risk of a road accident. Hypoglycemia while driving is considered to be the most risky situation, with diabetes increasing the mentioned risk for instance due to impaired vision in the case of possible retinopathy. The group of drivers with diabetes being at the greatest risk as to accidents are those with a case history of severe hypoglycemia or hypoglycemia occurred while driving, or possibly of a road accident. Measuring glycaemia before driving and their knowledge how to prevent and treat hypoglycemia - those are the two crucial preventive elements indispensable for insulin treated diabetes patients in order to secure safe road traffic.

The effect of cultureware surfaces on functional and structural components of differentiated 3T3-L1 preadipocytes.

Experiments using cultured primary cells or cell lines are a routine in vitro approach used across multiple biological disciplines, However, the structural and functional influences of various cultureware materials on cultured cells is not clearly understood. Surface treatments of cultureware have proven to have profound effects on cell viability and proliferation. In this study, we investigated the impact of polystyrene and fluorocarbon cultureware dishes on the proteomic profile of differentiated 3T3-L1 preadipocytes. After expansion and differentiation of cells on appropriate cultureware dishes, cell lysates were separated using two-dimensional gel electrophoresis and proteins were visualized with Coomassie blue staining. Spots with the highest differential expression between the two culture conditions were subsequently analyzed using matrix-assisted laser desorption/ionization mass spectrometry and the identified proteins were subjected to pathway analysis. We observed that 43% of all spots were differentially expressed depending on the cultureware. Pathway analysis revealed that glucose metabolism, mitochondrial structure and cell differentiation, represented by 14-3-3 protein-mediated signaling and the mitochondrial inner membrane organizing system (MINOS), were significantly affected by cultureware material. These results indicate that cultureware material can have a profound effect on key adipocyte functional pathways. These effects modifications of the cells should be reflected in the design of in vitro experiments and interpretation of their results.

System for exposing cultured cells to intermittent hypoxia utilizing gas permeable cultureware.

Tissue intermittent hypoxia (IH) occurs in obstructive sleep apnea, sickle cell anemia, physical exercise and other conditions. Poor gas solubility and slow diffusion through culture media hampers mimicking IH-induced transitions of O(2) in vitro. We aimed to develop a system enabling exposure of cultured cells to IH and to validate such exposure by real-time O(2) measurements and cellular responses. Standard 24-well culture plates and plates with bottoms made from a gas permeable film were placed in a heated cabinet. Desired cycling of O(2) levels was induced using programmable solenoids to purge mixtures of 95% N(2) + 5% CO(2) or 95% O(2) + 5% CO(2). Dissolved oxygen, gas pressure, temperature, and water evaporation were measured during cycling. IH-induced cellular effects were evaluated by hypoxia inducible factor (HIF) and NF-κB luciferase reporters in HEK296 cells and by insulin secretion in rat insulinoma cells. Oxygen cycling in the cabinet was translated into identical changes of O(2) at the well bottom in gas permeable, but not in standard cultureware. Twenty-four hours of IH exposure increased HIF (112%), NF-κB (111%) and insulin secretion (44%). Described system enables reproducible and prolonged IH exposure in cultured cells while controlling for important environmental factors.

[Factors causing damage and destruction of beta-cells of the islets of Langerhans in the pancreas]. / Faktory vedoucí k poskození a destrukci B-bunek Langerhansových ostruvku pankreatu.

Insulin secretion in patients with manifested diabetes mellitus tends to disappear months to decades after the diagnosis, which is a clear sign of a gradual loss of pancreatic islet beta-cells. In our sample of 30 type 2 diabetic patients, whose disease manifested between 30 and 45 years of age, about a half have retained or even increased insulin secretion 30 years later, while the other half exhibit a much diminished or lost insulin secretion. Factors that can damage or destroy beta-cells can be divided into the following groups: Metabolic factors: hyperglycemia and glucotoxicity, lipotoxicity, hypoxia, reactive oxygen species; Pharmacological factors: antimicrobial medication pentamidine, SSRI antidepressants; Factors related to impaired insulin secretion: MODY type diabetes; Environmental toxic factors: rat poison Vacor, streptozotocin, polychlorinated and polybrominated hydrocarbons; Disorders of the exocrine pancreas: tumor infiltration, fibrous infiltration, chronic pancreatitis, cystic fibrosis; Infections, inflammation, autoimmunity, viral factors: Coxsackie viruses, H1N1 influenza, enteroviruses. We are currently working on finding other factors leading to beta-cell damage, studying their effect on apoptosis and necrosis and looking for possible protective factors to prevent this damage. We our increasing knowledge about the mechanisms of beta-cell damage and destruction we come ever closer to suggest measures for their prevention. In this review we offer a brief and simplified summary of some of the findings related to this area.Key words: pancreatic islet beta-cells of Langerhans - factors damaging or destroying beta-cells - insulin secretion.

Sleep-disordered breathing increases mortality in patients with diabetes.

STUDY OBJECTIVES: Sleep-disordered breathing (SDB) and diabetes mellitus (DM) are often concomitant; however, data on the impact of SDB on mortality in the population with diabetes remain scarce. METHODS: The population from the Sleep Heart Health Study, a multicenter prospective observational study representing 5780 patients with polysomnography and mortality data, including 453 patients with DM, was analyzed to assess the impact of SDB variables and the presence of DM on all-cause, cardiovascular disease (CVD), and non-CVD associated mortality. Survival analysis and proportional hazard regression models were used to calculate the adjusted hazard ratios (aHR) for mortality. RESULTS: Patients with DM and the average SpO2 >91.4% had significantly lower all-cause (aHR 0.52, CI 0.34-0.80) and CVD mortality risk (aHR 0.44, CI 0.22-0.87) as compared with patients with SpO2 below this value. Apnea-hypopnea index >31 (aHR 1.58, CI 1.10-2.28) and oxygen desaturation index >13.3 (aHR 1.58, CI 1.10-2.25) were associated with increased all-cause mortality in participants with DM on treatment. Sleep efficiency and proportion of rapid-eye movement (REM) sleep did not have any impact on mortality in patients with DM and thus differed significantly from individuals without DM, where increased all-cause mortality was observed in those with sleep efficiency <81.4% (aHR 0.77, CI 0.68-0.87) or REM sleep <14.9% (aHR 0.78, CI 0.68-0.89). CONCLUSIONS: Patients with diabetes on treatment and moderate to severe sleep-disordered breathing experience increased all-cause mortality. Reduced average oxygen saturation predicted both all-cause and cardiovascular death in the population with diabetes.

Does PAD and microcirculation status impact the tissue availability of intravenously administered antibiotics in patients with infected diabetic foot? Results of the DFIATIM substudy.

Aims/hypothesis: The aim of this substudy (Eudra CT No:2019-001997-27)was to assess ATB availability in patients with infected diabetic foot ulcers(IDFUs)in the context of microcirculation and macrocirculation status. Methods: For this substudy, we enrolled 23 patients with IDFU. Patients were treated with boluses of amoxicillin/clavulanic acid(AMC)(12patients) or ceftazidime(CTZ)(11patients). After induction of a steady ATB state, microdialysis was performed near the IDFU. Tissue fluid samples from the foot and blood samples from peripheral blood were taken within 6 hours. ATB potential efficacy was assessed by evaluating the maximum serum and tissue ATB concentrations(Cmax and Cmax-tissue)and the percentage of time the unbound drug tissue concentration exceeds the minimum inhibitory concentration (MIC)(≥100% tissue and ≥50%/60% tissue fT>MIC). Vascular status was assessed by triplex ultrasound, ankle-brachial and toe-brachial index tests, occlusive plethysmography comprising two arterial flow phases, and transcutaneous oxygen pressure(TcPO2). Results: Following bolus administration, the Cmax of AMC was 91.8 ± 52.5 µgmL-1 and the Cmax-tissue of AMC was 7.25 ± 4.5 µgmL-1(P<0.001). The Cmax for CTZ was 186.8 ± 44.1 µgmL-1 and the Cmax-tissue of CTZ was 18.6 ± 7.4 µgmL-1(P<0.0001). Additionally, 67% of patients treated with AMC and 55% of those treated with CTZ achieved tissue fT>MIC levels exceeding 50% and 60%, respectively. We observed positive correlations between both Cmax-tissue and AUCtissue and arterial flow. Specifically, the correlation coefficient for the first phase was r=0.42; (P=0.045), and for the second phase, it was r=0.55(P=0.01)and r=0.5(P=0.021). Conclusions: Bactericidal activity proved satisfactory in only half to two-thirds of patients with IDFUs, an outcome that appears to correlate primarily with arterial flow.

Microdialysis as a tool for antibiotic assessment in patients with diabetic foot: a review.

Diabetic foot is a serious late complication frequently caused by infection and ischaemia. Both require prompt and aggressive treatment to avoid lower limb amputation. The effectiveness of peripheral arterial disease therapy can be easily verified using triplex ultrasound, ankle-brachial/toe-brachial index examination, or transcutaneous oxygen pressure. However, the success of infection treatment is difficult to establish in patients with diabetic foot. Intravenous systemic antibiotics are recommended for the treatment of infectious complications in patients with moderate or serious stages of infection. Antibiotic therapy should be initiated promptly and aggressively to achieve sufficient serum and peripheral antibiotic concentrations. Antibiotic serum levels are easily evaluated by pharmacokinetic assessment. However, antibiotic concentrations in peripheral tissues, especially in diabetic foot, are not routinely detectable. This review describes microdialysis techniques that have shown promise in determining antibiotic levels in the surroundings of diabetic foot lesions.

Catecholamine and insulin control of lipolysis in subcutaneous adipose tissue during long-term diet-induced weight loss in obese women.

The aim of this study was to investigate the evolution of the adrenergic and insulin-mediated regulation of lipolysis during different phases of a 6-mo dietary intervention. Eight obese women underwent a 6-mo dietary intervention consisting of a 1-mo very low-calorie diet (VLCD) followed by a 2-mo low-calorie diet (LCD) and 3-mo weight maintenance (WM) diet. At each phase of the dietary intervention, microdialysis of subcutaneous adipose tissue (SCAT) was performed at rest and during a 3-h hyperinsulinemic euglycemic clamp. Responses of dialysate glycerol concentration (DGC) were determined at baseline and during local perfusions with adrenaline or adrenaline and phentolamine before and during the last 30 min of the clamp. Dietary intervention induced a body weight reduction and an improved insulin sensitivity. DGC progressively decreased during the clamp, and this decrease was similar during the different phases of the diet. The adrenaline-induced increase in DGC was higher at VLCD and LCD compared with baseline condition and returned to prediet levels at WM. In the probe with adrenaline and phentolamine, the increase in DGC was higher than that in the adrenaline probe at baseline and WM, but it was not different at VLCD and LCD. The results suggest that the responsiveness of SCAT to adrenaline-stimulated lipolysis increases during the calorie-restricted phases due to a reduction of the α(2)-adrenoceptor-mediated antilipolytic action of adrenaline. At WM, adrenaline-stimulated lipolysis returned to the prediet levels. Furthermore, no direct relationship between insulin sensitivity and the diet-induced changes in the regulation of lipolysis was found.

Influence of Hyperglycaemia and CRP on the Need for Mechanical Ventilation in Guillain-Barré Syndrome.

Objectives: Elevated blood glucose and CRP (C-reactive protein) are usually related to a worsened clinical outcome in neurological diseases. This association in Guillain-Barré syndrome (GBS) has been studied rarely. We tried to analyse if hyperglycaemia and CRP at admission may influence the outcome of GBS, including mechanically ventilated (MV) patients. Methods: We retrospectively studied 66 patients (40 males, 19-93 years, average 56 years) without diabetes mellitus and free of corticoid treatment, who fulfilled the clinical criteria for diagnosis of GBS. Hyperglycaemia (the level of fasting plasma glucose, FPG) was defined as blood glucose level >5.59 mmol/L according to our laboratory. CRP >5 mg/L was considered as an abnormally elevated value. Results: At admission, 32 GBS patients (48%) had hyperglycaemia according to FPG level. A severe form of GBS (>4 according to Hughes GBS scale) was observed in 17 patients (26%); and 8 of them (47%) had hyperglycaemia. Fourteen patients (21%) were MV, and in 10 of them (71%) hyperglycaemia was present. CRP was significantly increased in MV patients. The linear model revealed a significant relationship between CRP and glycemia (p = 0.007) in subjects without MV (p = 0.049). In subjects with MV the relationship was not significant (p = 0.2162, NS). Conclusion: In the acute phase of GBS at admission, hyperglycaemia and higher CRP occur relatively frequently, and may be a risk factor for the severity of GBS. Stress hyperglycaemia due to impaired glucose homeostasis could be one explanation for this condition.

Hypoxia-Induced Sarcoplasmic Reticulum Ca2+ Leak Is Reversed by Ryanodine Receptor Stabilizer JTV-519 in HL-1 Cardiomyocytes.

BACKGROUND: To assess whether hypoxia, as can be found in obstructive sleep apnea syndrome, is causally associated with the development of heart failure through a direct effect on calcium leakage from the sarcoplasmic reticulum. METHODS: The impact of hypoxia on sarcoplasmic reticulum calcium leakage and expres- sion of RyR2 (ryanodine receptor2) and SERC2a (sarcoplasmic reticulum Ca2+ATPase 2a) was investigated together with the outcomes of JTV-519 and S107 treatment. HL-1 car- diomyocytes were cultured for 7 days on gas-permeable cultureware under control (12% O2) or hypoxic (1% O2) conditions with or without JTV-519 or S107. SRCL was assessed using a Fluo-5N probe. Gene and protein expression was analyzed using qPCR and western blotting. RESULTS: Hypoxic exposure increased sarcoplasmic reticulum calcium leakage by 39% and reduced RyR2 gene expression by 52%. No effect on RyR2 protein expression was observed. Treatment with 1µM JTV-519 reduced sarcoplasmic reticulum calcium leakage by 52% and 35% under control and hypoxic conditions, respectively. Administration of 1 µM JTV-519 increased RyR2 gene expression by 89% in control conditions. No effect on SRCL, RyR2, or SERC2a gene, or protein expression was observed with S107 treatment. CONCLUSION: Hypoxia increased sarcoplasmic reticulum calcium leakage which was ame- liorated by JTV-519 treatment independently of gene or protein expression. JTV-519 rep- resents a possible treatment for obstructive sleep apnea-associated HF.