The relationship between visceral adiposity and cardiometabolic risk in Chinese women with polycystic ovary syndrome.

OBJECTIVE: To compare the extent to which visceral adiposity, as measured by mesenteric fat thickness, contribute to cardiometabolic risk, especially insulin resistance, in women with PCOS and healthy control. METHODS: This is a cross-sectional study with a total of 190 women with PCOS fulfilling the Rotterdam diagnostic criteria. Women without PCOS were recruited from a previous study, which comprised 416 healthy women controls with normal glucose tolerance. All subjects underwent OGTT, biochemical assessment, and sonographic assessment with measurements of mesenteric, preperitoneal and subcutaneous fat thickness. RESULTS: Mesenteric fat thickness was strongly correlated to cardiometabolic traits including blood pressure, fasting and 2-h glucose, triglycerides, HOMA-IR; and was negatively correlated to HDL-C in both cohorts (all p < 0.01). In PCOS, positive correlation was observed between mesenteric fat thickness and free androgen index (p < 0.01). Compared with controls, the regression line between mesenteric fat and HOMA-IR is much steeper in PCOS (p < 0.01). CONCLUSION: Women with PCOS remain more insulin resistant compared to controls at any given degree of visceral adiposity.

Betaine supplementation to rats alleviates disturbances induced by high-fat diet: pleiotropic effects in model of type 2 diabetes.

Betaine is a biologically active compound exerting beneficial effects in the organism, however, the exact mechanisms underlying its action are not fully elucidated. The present study aimed to explore, whether betaine alleviates disorders induced by feeding rats a high-fat diet (HFD). Rats were divided into 3 groups: control, fed an HFD and fed an HFD and receiving betaine (2% water solution for 8 weeks). Betaine improved glucose tolerance, decreased blood levels of non-esterified fatty acids and prevented lipid accumulation in the skeletal muscle of rats on an HFD. Betaine reduced activities of blood alanine aminotransferase, blood levels of bilirubin and hepatic lipid content. Expression of fatty acid synthase in the liver and the skeletal muscle was decreased in response to feeding an HFD, and this effect was deepened by betaine in the muscle tissue. Hepatic and muscular expression of genes related to insulin signaling were unchanged in HFD-fed rats. Lipolysis stimulated by epinephrine (an adrenergic receptor agonist), forskolin (an activator of adenylate cyclase), dibutyryl-cAMP (an activator of protein kinase A) and DPCPX (an adenosine A1 receptor antagonist) was diminished in the adipocytes of rats fed an HFD, however, this effect was alleviated by betaine. Moreover, blood leptin levels in HFD-fed rats were elevated, whereas leptinemia have normalized by betaine supplementation. Betaine prevented the increase in expression of N-methyl D-aspartate receptors in the hippocampus and in the cerebral cortex. These results indicate that betaine positively affects the insulin-sensitive tissues: liver (hepatoprotective effects), skeletal muscle (reduced lipid accumulation) and adipose tissue (a rise in lipolysis), which is associated with improved insulin sensitivity. Betaine-induced prevention of hyperleptinemia indicates restoration of leptin action, and changes in the brain reveal neuroprotective properties. Our results show that betaine induces positive changes in HFD-fed rats, its action is pleiotropic and involves different tissues.

High risk of conversion to diabetes in first-degree relatives of individuals with young-onset type 2 diabetes: a 12-year follow-up analysis.

AIM: Family history of diabetes is an established risk factor for Type 2 diabetes, but the impact of a family history of young-onset diabetes (onset < 40 years) on future risk of diabetes among first-degree relatives is unclear. In this prospective study, we examined the influence of family history of late- versus young-onset diabetes on the development of diabetes in a young to middle-aged Chinese population. METHODS: Some 365 siblings identified through probands with Type 2 diabetes and 452 participants from a community-based health awareness project (aged 18-55 years) who underwent metabolic assessment during the period 1998-2002 were followed to 2012-2013 to determine their glycaemic status. Multivariate logistic regression was performed to investigate the association of family history of diabetes presented at different age categories with development of diabetes. RESULTS: In this cohort, 53.4% (n = 167) of participants with a family history of young-onset diabetes, 30.1% (n = 68) of those with a family history of late-onset diabetes and 14.4% (n = 40) of those without a family history developed diabetes. Using logistic regression, family history of diabetes presented at ages ≥ 50, 40-49, 30-39 and < 30 years, increased conversion to diabetes with respective odds ratios of 2.4, 5.8, 9.4 and 7.0 (P < 0.001 for all), after adjustment for socio-economic status, smoking, obesity, hypertension and dyslipidaemia. Among participants without diabetes at baseline, risk association of family history of late-onset diabetes with incident diabetes was not sustained, whereas that of family history of young-onset diabetes remained robust on further adjustment for baseline glycaemic measurements. CONCLUSIONS: First-degree relatives of people with Type 2 diabetes, especially relatives of those with young-onset diabetes, are at high risk for diabetes.

Contraction-induced interleukin-6 gene transcription in skeletal muscle is regulated by c-Jun terminal kinase/activator protein-1.

Exercise increases the expression of the prototypical myokine IL-6, but the precise mechanism by which this occurs has yet to be identified. To mimic exercise conditions, C2C12 myotubes were mechanically stimulated via electrical pulse stimulation (EPS). We compared the responses of EPS with the pharmacological Ca(2+) carrier calcimycin (A23187) because contraction induces marked increases in cytosolic Ca(2+) levels or the classical IκB kinase/NFκB inflammatory response elicited by H(2)O(2). We demonstrate that, unlike H(2)O(2)-stimulated increases in IL-6 mRNA, neither calcimycin- nor EPS-induced IL-6 mRNA expression is under the transcriptional control of NFκB. Rather, we show that EPS increased the phosphorylation of JNK and the reporter activity of the downstream transcription factor AP-1. Furthermore, JNK inhibition abolished the EPS-induced increase in IL-6 mRNA and protein expression. Finally, we observed an exercise-induced increase in both JNK phosphorylation and IL-6 mRNA expression in the skeletal muscles of mice after 30 min of treadmill running. Importantly, exercise did not increase IL-6 mRNA expression in skeletal muscle-specific JNK-deficient mice. These data identify a novel contraction-mediated transcriptional regulatory pathway for IL-6 in skeletal muscle.

IκB kinase ß (IKKß) does not mediate feedback inhibition of the insulin signalling cascade.

In the present study, we have examined whether IKKß [IκB (inhibitor of nuclear factor κB) kinase ß] plays a role in feedback inhibition of the insulin signalling cascade. Insulin induces the phosphorylation of IKKß, in vitro and in vivo, and this effect is dependent on intact signalling via PI3K (phosphoinositide 3-kinase), but not PKB (protein kinase B). To test the hypothesis that insulin activates IKKß as a means of negative feedback, we employed a variety of experimental approaches. First, pharmacological inhibition of IKKß via BMS-345541 did not potentiate insulin-induced IRS1 (insulin receptor substrate 1) tyrosine phosphorylation, PKB phosphorylation or 2-deoxyglucose uptake in differentiated 3T3-L1 adipocytes. BMS-345541 did not prevent insulin-induced IRS1 serine phosphorylation on known IKKß target sites. Secondly, adenovirus-mediated overexpression of wild-type IKKß in differentiated 3T3-L1 adipocytes did not suppress insulin-stimulated 2-deoxyglucose uptake, IRS1 tyrosine phosphorylation, IRS1 association with the p85 regulatory subunit of PI3K or PKB phosphorylation. Thirdly, insulin signalling was not potentiated in mouse embryonic fibroblasts lacking IKKß. Finally, insulin treatment of 3T3-L1 adipocytes did not promote the recruitment of IKKß to IRS1, supporting our findings that IKKß, although activated by insulin, does not promote direct serine phosphorylation of IRS1 and does not contribute to the feedback inhibition of the insulin signalling cascade.

Suppression of inflammation-associated factors by indole-3-carbinol in mice fed high-fat diets and in isolated, co-cultured macrophages and adipocytes.

AIMS: This study investigated the effects of indole-3-carbinol (I3C), a compound from cruciferous vegetables, on various parameters related to obesity, in particular, the parameters of infiltration by macrophages and of inflammatory cytokines expressed during the co-culture of adipocytes and macrophages. METHODS: Male C57BL/6 mice were fed with a control diet (C group), high-fat diet (HF group) and HF+5 mg kg(-1) I3C (HFI group). The I3C was intraperitoneally injected (HFI group) for 12 weeks. Epididymal adipose tissue (AT) was collected and stained for F4/80, a marker of macrophages. RESULTS: The immunohistochemical staining for F4/80 indicated a greater presence of macrophages in the HF group than in AT from the control and HFI groups. Furthermore, I3C treatment, in an in vitro cell culture system, decreased expression of inducible nitric oxide synthase (iNOS), decreased nitrite content and enhanced expression of peroxisome proliferator-activated receptor (PPAR-γ). Moreover, in vitro cell culture studies revealed that I3C inhibited intracellular lipid accumulation in hypertrophied adipocytes. In macrophage and primary adipocyte co-culture, I3C inhibited expression of interleukin-6 (IL-6). CONCLUSIONS: In vivo treatment with I3C reduced the infiltration of macrophages in AT, and in vitro addition of I3C to co-cultured macrophages and adipocytes reduced nitrite production and IL-6 expression. With cultures of adipocytes only, I3C inhibited accumulation of intracellular lipid, either by disrupting differentiation, or by directly inhibiting triglyceride synthesis.

Sonographic measurement of mesenteric fat predicts presence of fatty liver among subjects with polycystic ovary syndrome.

OBJECTIVE: Visceral fat is believed to be important in the pathogenesis of metabolic syndrome and fatty liver. In this study, we examined the relationship between mesenteric fat thickness and other sonographic indices of adiposity and the presence of fatty liver among subjects with polycystic ovary syndrome (PCOS). SUBJECTS AND METHODS: A total of 117 Chinese subjects with PCOS were evaluated (mean age, 28.6 ± 6.5 yr; mean body mass index, 24.3 ± 5.3 kg/m(2)). Anthropometric measurements and metabolic risk profile, including a standard oral glucose tolerance test, were assessed in all subjects. All subjects underwent an ultrasound examination for measurement of thickness of mesenteric, preperitoneal, and sc fat as well as evaluation for fatty liver. RESULTS: Forty-six (39.3%) of the subjects had fatty liver. PCOS subjects with fatty liver had higher body mass index, waist circumference, waist-hip ratio, and systolic blood pressure; a more unfavorable lipid profile with higher triglyceride; lower high-density lipoprotein cholesterol; higher fasting glucose and insulin; higher 2-h glucose during oral glucose tolerance test; lower SHBG; and higher alanine aminotransferase. Subjects with fatty liver had increased thickness of preperitoneal, mesenteric, and sc fat, as well as increased carotid intima-media thickness. Abdominal fat thickness showed moderate correlation to alanine aminotransferase as well as fasting insulin. On multivariate logistic regression, fasting insulin and mesenteric fat thickness were identified as independent predictors of fatty liver among subjects with PCOS. CONCLUSION: Fatty liver is present in a significant proportion of Chinese patients with PCOS. Sonographic measurement of mesenteric fat is an independent determinant of fatty liver among subjects with PCOS and identifies subjects at increased cardiovascular risk.

Interleukin-6-deficient mice develop hepatic inflammation and systemic insulin resistance.

AIMS/HYPOTHESIS: The role of IL-6 in the development of obesity and hepatic insulin resistance is unclear and still the subject of controversy. We aimed to determine whether global deletion of Il6 in mice (Il6 (-/-)) results in standard chow-induced and high-fat diet (HFD)-induced obesity, hepatosteatosis, inflammation and insulin resistance. METHODS: Male, 8-week-old Il6 (-/-) and littermate control mice were fed a standard chow or HFD for 12 weeks and phenotyped accordingly. RESULTS: Il6 (-/-) mice displayed obesity, hepatosteatosis, liver inflammation and insulin resistance when compared with control mice on a standard chow diet. When fed a HFD, the Il6 (-/-) and control mice had marked, equivalent gains in body weight, fat mass and ectopic lipid deposition in the liver relative to chow-fed animals. Despite this normalisation, the greater liver inflammation, damage and insulin resistance observed in chow-fed Il6 (-/-) mice relative to control persisted when both were fed the HFD. Microarray analysis from livers of mice fed a HFD revealed that genes associated with oxidative phosphorylation, the electron transport chain and tricarboxylic acid cycle were uniformly decreased in Il6 (-/-) relative to control mice. This coincided with reduced maximal activity of the mitochondrial enzyme ß-hydroxyacyl-CoA-dehydrogenase and decreased levels of mitochondrial respiratory chain proteins. CONCLUSIONS/INTERPRETATION: Our data suggest that IL-6 deficiency exacerbates HFD-induced hepatic insulin resistance and inflammation, a process that appears to be related to defects in mitochondrial metabolism.

Life-threatening Torsades de Pointes resulting from "natural" cancer treatment.

INTRODUCTION: Nonradioactive cesium chloride (CsCl) is used by some alternative medicine advocates as a treatment for cancer. The therapy was proven to be neither safe nor effective. Chronic use of CsCl has resulted in cases with severe cardiotoxicity. CASE REPORT: A 65-year-old lady presented to our hospital's accident and emergency department with recurrent syncope attacks. Electrocardiogram monitoring showed QT prolongation and transient Torsades de Pointes (TDP) ventricular tachycardia. She was taking anticancer naturopathic drugs for 6 weeks before admission. One of her naturopathic drugs was subsequently confirmed containing 89% CsCl by weight. Besides conventional treatment of QT prolongation and TDP, the patient was given a 4-week course of oral Prussian blue to enhance gastrointestinal elimination of cesium. The serum half-life of cesium was reduced from 61.7 to 29.4 days after the use of Prussian blue. QT prolongation was normalized in 27 days. DISCUSSION: To our knowledge, this is the first published case of nonradioactive cesium poisoning treated with Prussian blue. A transient rise in serum cesium level was observed during Prussian blue therapy. Possible explanations for this observation include poor drug compliance during outpatient treatment and redistribution of cesium from body stores. CONCLUSION: Nonradioactive CsCl poisoning can result in severe cardiotoxicity with QT prolongation and TDP ventricular tachycardia. The key points in the management of nonradioactive cesium poisoning include cessation of cesium exposure, vigorous electrolytes replacement, and oral Prussian blue therapy.

Brain-derived neurotrophic factor is produced by skeletal muscle cells in response to contraction and enhances fat oxidation via activation of AMP-activated protein kinase.

AIMS/HYPOTHESIS: Brain-derived neurotrophic factor (BDNF) is produced in skeletal muscle, but its functional significance is unknown. We aimed to determine the signalling processes and metabolic actions of BDNF. METHODS: We first examined whether exercise induced BDNF expression in humans. Next, C2C12 skeletal muscle cells were electrically stimulated to mimic contraction. L6 myotubes and isolated rat extensor digitorum longus muscles were treated with BDNF and phosphorylation of the proteins AMP-activated protein kinase (AMPK) (Thr(172)) and acetyl coenzyme A carboxylase beta (ACCbeta) (Ser(79)) were analysed, as was fatty acid oxidation (FAO). Finally, we electroporated a Bdnf vector into the tibialis cranialis muscle of mice. RESULTS: BDNF mRNA and protein expression were increased in human skeletal muscle after exercise, but muscle-derived BDNF appeared not to be released into the circulation. Bdnf mRNA and protein expression was increased in muscle cells that were electrically stimulated. BDNF increased phosphorylation of AMPK and ACCbeta and enhanced FAO both in vitro and ex vivo. The effect of BDNF on FAO was AMPK-dependent, since the increase in FAO was abrogated in cells infected with an AMPK dominant negative adenovirus or treated with Compound C, an inhibitor of AMPK. Electroporation of a Bdnf expression vector into the tibialis cranialis muscle resulted in increased BDNF protein production and tropomyosin-related kinase B (TrkB(Tyr706/707)) and extracellular signal-regulated protein kinase (p44/42 Thr(202)/Tyr(204)) phosphorylation in these muscles. In addition, phosphorylation of ACCbeta was markedly elevated in the Bdnf electroporated muscles. CONCLUSIONS/INTERPRETATION: These data identify BDNF as a contraction-inducible protein in skeletal muscle that is capable of enhancing lipid oxidation in skeletal muscle via activation of AMPK.

HSP72 protects against obesity-induced insulin resistance.

Patients with type 2 diabetes have reduced gene expression of heat shock protein (HSP) 72, which correlates with reduced insulin sensitivity. Heat therapy, which activates HSP72, improves clinical parameters in these patients. Activation of several inflammatory signaling proteins such as c-jun amino terminal kinase (JNK), inhibitor of kappaB kinase, and tumor necrosis factor-alpha, can induce insulin resistance, but HSP 72 can block the induction of these molecules in vitro. Accordingly, we examined whether activation of HSP72 can protect against the development of insulin resistance. First, we show that obese, insulin resistant humans have reduced HSP72 protein expression and increased JNK phosphorylation in skeletal muscle. We next used heat shock therapy, transgenic overexpression, and pharmacologic means to overexpress HSP72 either specifically in skeletal muscle or globally in mice. Herein, we show that regardless of the means used to achieve an elevation in HSP72 protein, protection against diet- or obesity-induced hyperglycemia, hyperinsulinemia, glucose intolerance, and insulin resistance was observed. This protection was tightly associated with the prevention of JNK phosphorylation. These findings identify an essential role for HSP72 in blocking inflammation and preventing insulin resistance in the context of genetic obesity or high-fat feeding.

Elevation of pro-inflammatory cytokines, C-reactive protein and cardiac troponin T in chronic renal failure patients on dialysis.

Chronic renal failure (CRF) patients suffer from a chronic inflammation. They are at increased risk of cardiovascular disease. In order to investigate this inflammatory process and cardiovascular risk factors associated with haemodialysis (HD) and peritoneal dialysis (PD), we compared serum/plasma pro-inflammatory cytokines, C-reactive protein (CRP), and cardiac troponin T (cTnT) of 146 CRF patients treated or not treated with PD or HD. Serum cytokines and CRP as well as plasma cTnT were measured by enzyme-linked immunosorbent assay, chemiluminescence immunoassay, and electrochemiluminescence immunoassay, respectively. Results indicated that serum interleukin (IL)-18 concentrations were significantly higher in PD and low creatinine clearance pre-dialysis CRF (LCC) patients than HD patients (both p < 0.05). IL-6 and tumour necrosis factor (TNF)-alpha concentrations were significantly higher in PD patients than LCC patients (both p < 0.01). Serum hsCRP and plasma cTnT in HD were significantly higher than LCC (both p < 0.01). The elevation of pro-inflammatory cytokines should play an important role in the chronic inflammation and increased cardiovascular risk of CRF patients on dialysis. We are evaluating further the diagnostic and prognostic applications of pro-inflammatory cytokines and biochemical inflammatory markers for these patients.

Near-miss errors in laboratory blood test requests by interns.

BACKGROUND: Human errors have proven to be one of the most formidable patient care challenges in acute hospital setting. AIM: To evaluate the at-risk period for near-miss errors in laboratory blood test requests, in an acute medical hospital. DESIGN: Hospital-based retrospective analysis. METHODS: We reviewed the database of voluntary reports for near-miss errors for laboratory blood test requests by 104 medical residents in their first postgraduate year (interns), over a 2-year period (October 2002 to September 2004). To identify patterns and causal factors we analysed the reports with respect to months of working experience, work hours, and work shifts of an extended duration. RESULTS: There were 52 near-miss events among patients cared for by the medical service (20 male patients, 32 females, mean age 72.6 +/- 9.7 years). The overall incidence of near-miss events when interns practiced during the first month of training vs. subsequent months was 1.6 (95%CI 0.77-2.9) vs. 0.6 (95%CI 0.44-0.83) cases per 100 intern-days at risk. The odds ratio for a near-miss event during the first month of intern training vs. subsequent months was 2.64 (95%CI 1.29-5.38). With respect to the interns' on-call shift schedule, one half of the near-miss episodes occurred during an intern's on-call days and another half of them during an extended on-call shift; none of the events occurred during a standard working shift. These events peaked in frequency when on-call interns had worked for 12-20 h. DISCUSSION: The first month of internship represents an error-prone period. The best interventions to reduce near-miss errors by recently graduated medical interns should be the subject of further research.

Altering dietary nutrient intake that reduces glycogen content leads to phosphorylation of nuclear p38 MAP kinase in human skeletal muscle: association with IL-6 gene transcription during contraction.

To determine the effect of glycogen availability and contraction on intracellular signaling and IL-6 gene transcription, eight males performed 60 min of exercise on two occasions: either with prior ingestion of a normal (Con) or low carbohydrate (LCHO) diet that reduced pre-exercise muscle glycogen content. Muscle biopsies were obtained and analyzed for IL-6 mRNA. In addition, nuclear proteins were isolated from the samples and analyzed for the mitogen- activated protein kinases (MAPK) c-jun amino-terminal kinase (JNK) 1 and 2 and p38 MAPK. Nuclear fractions were also analyzed for the phosphorylated forms of JNK (p-JNK) and p38 MAPK (p-p38 MAPK) and the abundance of the nuclear transcription factors nuclear factor of activated T cells (NFAT) and nuclear factor kappa-beta (NF-kappabeta). No differences were observed in the protein abundance of total JNK 1/2, p38 MAPK, NFAT, or NF-kappabeta before exercise, but the nuclear abundance of p-p38 MAPK was higher (P<0.05) in LCHO. Contraction resulted in an increase (P<0.05) in nuclear p-JNK 1/2, but there were no differences when comparing CON with LCHO. The fold increase in IL-6 mRNA with contraction was potentiated (P<0.05) in LCHO. A correlation between pre-exercise nuclear phosphorylated p38 MAPK and contraction-induced fold increase in IL-6 mRNA was performed, revealing a highly significant correlation (r=0.96; P<0.01). We next incubated L6 myotubes in ionomycin (a compound known to induce IL-6 mRNA) with or without the pyridinylimidazole p38 MAPK inhibitor SB203580. Treatments did not affect total nuclear p38 MAPK, but ionomycin increased (P<0.05) both nuclear p-p38 MAPK and IL-6 mRNA. The addition of SB203580 to ionomycin decreased (P<0.05) nuclear p-p38 MAPK and totally abolished (P<0.05) the ionomycin- induced increase in IL-6 mRNA. These data suggest that reduced carbohydrate intake that results in low intramuscular glycogen leads to phosphorylation of p38 MAPK at the nucleus. Furthermore, phosphorylation of p38 MAPK in the nucleus appears to be an upstream target for IL-6, providing new insights into the regulation of IL-6 gene transcription.

Role of beta-blockade in anaesthesia and postoperative pain management after hysterectomy.

BACKGROUND: Perioperative use of beta-blockers has been advocated as a strategy to prevent cardiac sequelae. This study evaluated the influence of perioperative esmolol administration upon anaesthesia and postoperative pain management amongst patients undergoing hysterectomy. METHODS: Ninety-seven ASA I-II patients, undergoing abdominal total hysterectomy, were randomly divided into one of two groups. Patients in the Esmolol group received an i.v. loading dose of esmolol 0.5 mg kg(-1) followed by infusion of 0.05 mg kg(-1) min(-1) before anaesthesia induction. The infusion was documented at the completion of surgery. The Control group received a volume of normal saline. After surgery, all patients were treated with patient-controlled i.v. analgesia (PCA), which was programmed to deliver 1 mg of morphine on demand for 3 consecutive days. Pain intensity on movement and at rest, sedation score, and side effects were recorded. RESULTS: The two groups were comparable with respect to their characteristics. Patients in the esmolol group received significantly lower end-tidal isoflurane concentrations (1.0 (0.3) vs 1.4 (0.5)%, respectively; P<0.001) and fentanyl (0.9 (0.2) vs 1.2 (0.5) microg kg(-1), respectively; P=0.006) during anaesthesia. They also showed a reduced heart rate and arterial pressure response to tracheal intubation, skin incision, and tracheal extubation. The Esmolol group consumed less PCA morphine in 3 days (37.3 (8.4) vs 54.7 (11.2) mg, respectively; P=0.005). Pain intensity and medication side effects were similar in the two groups. CONCLUSION: The results suggest that perioperative esmolol administration during anaesthesia reduces the intraoperative use of inhalation anaesthetic and fentanyl, decreases haemodynamic responses, and reduced morphine consumption for the first 3 postoperative days.

Cytokine gene expression in human skeletal muscle during concentric contraction: evidence that IL-8, like IL-6, is influenced by glycogen availability.

To determine the expression and induction of cytokines in human skeletal muscle during concentric contractions, eight males performed 60 min of bicycle exercise, with either a normal (Con) or reduced (Lo Gly) preexercise intramuscular glycogen content. Muscle biopsy samples were obtained before and after exercise and analyzed for glycogen and the mRNA expression of 13 cytokines. Resting muscle glycogen was higher (P < 0.05) in Con compared with Lo Gly and was reduced (P < 0.05) to 102 +/- 32 vs. 17 +/- 5 mmol U glycosyl/kg dry mass for Con and Lo Gly, respectively. We detected mRNA levels in human skeletal muscle for five cytokines, namely interleukin (IL)-1 beta, IL-6, IL-8, IL-15, and tumor necrosis factor-alpha. However, muscle contraction increased (P < 0.05) the mRNA expression of IL-6 and IL-8 alone. In addition, the fold change for both IL-8 and IL-6 was markedly higher (P < 0.05) in Lo Gly compared with Con. Given these results, we analyzed venous blood samples, obtained before and during exercise, for IL-6 and IL-8. Plasma IL-6 was not different at rest, and although the circulating concentration of this cytokine increased (P < 0.05) it increased to a greater extent (P < 0.05) throughout exercise in Lo Gly. In contrast, plasma IL-8 was not affected by exercise or treatment. These data demonstrate that cytokines are not ubiquitously expressed in skeletal muscle and that only IL-6 and IL-8 mRNA are increased during contraction of this mode and duration. Furthermore, the mRNA abundance of IL-6 and IL-8 appears to be influenced by glycogen availability in the contracting muscle.

Skeletal myocytes are a source of interleukin-6 mRNA expression and protein release during contraction: evidence of fiber type specificity.

In this study, we aimed to determine whether skeletal muscle cells per se are a source of interleukin (IL)-6 during contraction and whether IL-6 production is fiber type specific. Muscle biopsy samples were collected from seven males before (PRE) and after (POST) completing 120 min of continuous bicycle ergometry. Biopsies were sectioned and analyzed for the following: IL-6 protein detected by immunohistochemistry (IHC), IL-6 mRNA content detected by in situ hybridization, fiber type measured by either IHC or myofibrillar ATPase activity stain, and glycogen content measured by periodic acid schiff (PAS) assay. Fibers were qualitatively categorized according to glycogen content to one of five groups (1-5), with 1 being very low (LOW) and 5 being very high (HIGH) glycogen. Total fluorescence (PRE vs. POST) and glycogen-dependent fluorescence (LOW vs. HIGH) of IL-6 protein were quantitated using Metamorph software. Total IL-6 protein was elevated from PRE to POST exercise (P<0.05). At PRE, IL-6 protein was evenly distributed across all fibers at low levels, consistent with glycogen distribution. At POST, IL-6 protein was greater (P<0.05) in HIGH compared with LOW glycogen fibers, which coincided with type 2 fibers. IL-6 mRNA was distributed peripherally in all fibers at PRE. At POST, however, IL-6 mRNA appeared predominantly in type 2 fibers, which also had higher glycogen content (P<0.05). These data demonstrate that myocytes per se are a source of IL-6 produced during contraction. Our data also suggest that type 2 fibers predominantly produce IL-6 during muscle contractile activity.

Plasma inflammatory cytokines and chemokines in severe acute respiratory syndrome.

Severe acute respiratory syndrome (SARS) is a recently emerged infectious disease caused by a novel coronavirus, but its immunopathological mechanisms have not yet been fully elucidated. We investigated changes in plasma T helper (Th) cell cytokines, inflammatory cytokines and chemokines in 20 patients diagnosed with SARS. Cytokine profile of SARS patients showed marked elevation of Th1 cytokine interferon (IFN)-gamma, inflammatory cytokines interleukin (IL)-1, IL-6 and IL-12 for at least 2 weeks after disease onset, but there was no significant elevation of inflammatory cytokine tumour necrosis factor (TNF)-alpha, anti-inflammatory cytokine IL-10, Th1 cytokine IL-2 and Th2 cytokine IL-4. The chemokine profile demonstrated significant elevation of neutrophil chemokine IL-8, monocyte chemoattractant protein-1 (MCP-1), and Th1 chemokine IFN-gamma-inducible protein-10 (IP-10). Corticosteroid reduced significantly IL-8, MCP-1 and IP-10 concentrations from 5 to 8 days after treatment (all P < 0.001). Together, the elevation of Th1 cytokine IFN-gamma, inflammatory cytokines IL-1, IL-6 and IL-12 and chemokines IL-8, MCP-1 and IP-10 confirmed the activation of Th1 cell-mediated immunity and hyperinnate inflammatory response in SARS through the accumulation of monocytes/macrophages and neutrophils.

Alpha-fetoprotein variants in a case of pancreatoblastoma.

We describe a 6-year-old boy with histologically confirmed pancreatoblastoma and a markedly elevated serum alpha-fetoprotein (AFP) concentration. Due to local tumour invasion, cytotoxic chemotherapy was given to debulk the tumour before attempting surgical resection. Serial serum AFP concentrations were measured on this patient. During chemotherapy there was a > 95% fall in total AFP. Tumour-specific variants of AFP, detected by isoelectric focusing, also disappeared during chemotherapy but recurred when chemotherapy was withdrawn. It is suggested that although there was no change in overall size of the tumour, as assessed by various imaging techniques, the changes in serological markers may indicate that the treatment did in fact cause considerable tumour necrosis, AFP and its variants may be useful markers of tumour response in patients with pancreatoblastoma. The expression of AFP and its variants in pancreatoblastoma may be related to the embryonic origin of the pancreas.