Triglycerides-diabetes association in healthy middle-aged men: modified by physical fitness? A long term follow-up of 1962 Norwegian men in the Oslo Ischemia Study.

AIMS: To examine the impact of physical fitness (PF) on the association between fasting serum triglycerides (FTG) and diabetes risk and whether temporal changes in FTG predict diabetes risk in healthy middle-aged men. METHODS: FTG and PF (bicycle exercise test) were measured in 1962 men aged 40-59 years in 1972-1975 (Survey 1) and repeated in 1387 still healthy men on average 7.3 years later (Survey 2). Diabetes was diagnosed according to WHO 1985-criteria. RESULTS: During 35 years follow-up 202/1962 (10.3%) men developed diabetes. Compared with the lowest, the upper FTG tertile had a 2.58-fold (95% CI: 1.81-3.74) diabetes risk adjusted for age, fasting blood glucose and maternal diabetes, and a 2.29-fold (95%CI: 1.60-3.33) when also adjusting for PF. Compared with unchanged (±25%) FTG levels (n=664), FTG reduction of more than 25% (n=261) was associated with 56% lower (0.44; 95% CI: 0.24-0.75) diabetes risk, while FTG increase of more than 25% (n=462) was associated with similar risk. These associations were unchanged when adjusted for PF and PF change. CONCLUSIONS: High FTG-levels predicted long-term diabetes risk in healthy middle-aged men, and the association was only modestly weakened when adjusted for PF. A reduction in FTG was associated with decreased diabetes risk.

Benfotiamine increases glucose oxidation and downregulates NADPH oxidase 4 expression in cultured human myotubes exposed to both normal and high glucose concentrations.

The aim of the present work was to study the effects of benfotiamine (S-benzoylthiamine O-monophosphate) on glucose and lipid metabolism and gene expression in differentiated human skeletal muscle cells (myotubes) incubated for 4 days under normal (5.5 mM glucose) and hyperglycemic (20 mM glucose) conditions. Myotubes established from lean, healthy volunteers were treated with benfotiamine for 4 days. Glucose and lipid metabolism were studied with labeled precursors. Gene expression was measured using real-time polymerase chain reaction (qPCR) and microarray technology. Benfotiamine significantly increased glucose oxidation under normoglycemic (35 and 49% increase at 100 and 200 µM benfotiamine, respectively) as well as hyperglycemic conditions (70% increase at 200 µM benfotiamine). Benfotiamine also increased glucose uptake. In comparison, thiamine (200 µM) increased overall glucose metabolism but did not change glucose oxidation. In contrast to glucose, mitochondrial lipid oxidation and overall lipid metabolism were unchanged by benfotiamine. The expression of NADPH oxidase 4 (NOX4) was significantly downregulated by benfotiamine treatment under both normo- and hyperglycemic conditions. Gene set enrichment analysis (GSEA) showed that befotiamine increased peroxisomal lipid oxidation and organelle (mitochondrial) membrane function. In conclusion, benfotiamine increases mitochondrial glucose oxidation in myotubes and downregulates NOX4 expression. These findings may be of relevance to type 2 diabetes where reversal of reduced glucose oxidation and mitochondrial capacity is a desirable goal.

Directing an appropriate immune response: the role of defense collagens and other soluble pattern recognition molecules.

Defense collagens and other soluble pattern recognition receptors contain the ability to recognize and bind molecular patterns associated with pathogens (PAMPs) or apoptotic cells (ACAMPs) and signal appropriate effector-function responses. PAMP recognition by defense collagens C1q, MBL and ficolins leads to rapid containment of infection via complement activation. However, in the absence of danger, such as during the clearance of apoptotic cells, defense collagens such as C1q, MBL, ficolins, SP-A, SP-D and even adiponectin have all been shown to facilitate enhanced phagocytosis and modulate induction of cytokines towards an anti-inflammatory profile. In this way, cellular debris can be removed without provoking an inflammatory immune response which may be important in the prevention of autoimmunity and/or resolving inflammation. Indeed, deficiencies and/or knock-out mouse studies have highlighted critical roles for soluble pattern recognition receptors in the clearance of apoptotic bodies and protection from autoimmune diseases along with mediating protection from specific infections. Understanding the mechanisms involved in defense collagen and other soluble pattern recognition receptor modulation of the immune response may provide important novel insights into therapeutic targets for infectious and/or autoimmune diseases and additionally may identify avenues for more effective vaccine design.

Interferon-gamma receptor-1 gene polymorphism in tuberculosis patients from Croatia.

Recent studies have indicated that the interleukin-12/interferon-gamma (IFN-gamma) axis is important in mycobacterial infection susceptibility. Using an intronic (CA)n polymorphic microsatellite marker within the IFN-gamma receptor-1 (IFNGR1) gene, we have compared the allelic frequencies of this marker in hospitalized tuberculosis patients (n = 120) with that of controls (n = 87) from Rijeka, Croatia. We identified 13 (CA)n alleles in the tuberculosis patients, whereas only 10 were found in the controls. A significant difference between one allelic marker and the control group was observed (P = 0.02, 95% confidence interval 0.14-0.94), suggesting a possible protective association. In contrast, several other allelic markers showed a trend towards association with the disease. We also found a trend towards an increased frequency in homozygosity of one allelic marker in patients (11.7%) as compared with controls (4.6%). We conclude that there is no evidence for disease association of the IFNGR1 gene marker in Mendelian-type (single-allele) inheritance. However, our results also suggest that unidentified allelic variations in the IFNGR1 gene might elevate or decrease the risk in this ethnic population, as a part of the multigenic predisposition to tuberculosis.

Tailoring anti-complement therapeutics.

Complement is a core component of the immune system, which performs vital roles in immune surveillance. However, the active products that enable complement to perform its physiological roles can inappropriately target self tissues and cause pathology. Complement-mediated inflammation and tissue destruction is an important drive to pathology in diseases as diverse as rheumatoid arthritis and dementia. Two decades ago there were no agents that could be used therapeutically to inhibit the activation of complement, but increased understanding of the natural control of complement in vivo has markedly changed this situation. The realization that drugs mimicking the action of the complement regulatory proteins present on self cells, and in plasma, could effectively control pathological activation of complement has opened the door to the use of anticomplement therapy in disease. Here we will review the development of anticomplement therapeutics from the first generation agents, which are unmodified recombinant forms of natural regulators, to recent strategies for making better drugs. We will describe strategies for targeting the anticomplement activity to the site of disease, and for extending the plasma half-life of the agent. Finally, we will illustrate a novel approach to the delivery of anticomplement agents, making prodrugs that are activated only at disease sites thus minimizing the deleterious effects of systemic complement inhibition.

A preliminary study of circadian serum cortisol concentrations in response to a 72-hour fast in rheumatoid arthritis patients not previously treated with corticosteroids.

The aim of the study was to investigate the effects a 72-h fast upon serum total and free cortisol concentrations in RA patients not previously treated with glucocorticoids. Total serum cortisol and transcortin concentrations were measured in four RA patients with active disease at 4-h intervals during two 24-h periods (1200 h-1200 h), the first while eating a normal diet (fed state) and the second during the last 24 h of a 72-h water fast. Free cortisol concentrations were calculated from the total cortisol and transcortin values. The 3-day fast increased overall 24-h free and total cortisol concentrations by 50% and 35%, respectively. This was due largely to a marked increase in nocturnal serum cortisol concentrations during fasting, particularly at 0400 h, when mean total and free cortisol levels were increased by 170% and 260% compared to the fed state. Between 2000 and 0800 h overall total- and free cortisol concentrations were increased by 72% and 99%, respectively. These results suggest that an increase in nocturnal concentrations of cortisol occurs in response to fasting in RA patients not previously treated with glucocorticoids. These increases may mediate the beneficial clinical response previously found in studies of longer fasting periods in RA patients.

Serum levels of interleukin-6 and dehydroepiandrosterone sulphate in response to either fasting or a ketogenic diet in rheumatoid arthritis patients.

OBJECTIVE: To investigate the effects of either a 7-day fast or a 7-day ketogenic diet upon serum interleukin-6 (IL-6) and dehydroepiandrosterone sulphate (DHEAS) in RA patients. METHODS: We measured serum concentrations of DHEAS and IL-6 in 23 RA patients with active disease, 10 of whom followed a 7-day sub-total fast and 13 of whom consumed a ketogenic diet (isoenergetic, carbohydrate < 40 g/day) for 7 days. Clinical and laboratory variables were measured at baseline, on day 7 and after re-feeding on day 21. Correlation analyses were used to assess the associations between serum IL-6, DHEAS and disease activity variables at each timepoint. RESULTS: Fasting, but not the ketogenic diet, decreased serum IL-6 concentrations by 37% (p < 0.03) and improved disease activity at day 7. Both fasting and the ketogenic diet increased serum DHEAS levels by 34% as compared with baseline (both p < 0.006). Levels of IL-6, but not DHEAS, correlated with several disease activity variables. CONCLUSION: Both fasting and a ketogenic diet significantly increased serum DHEAS concentrations in RA patients. Only fasting significantly decreased serum IL-6 levels and improved disease activity. As the increases in serum DHEAS were similar in response to both fasting and a ketogenic diet, it is unlikely that the fall in serum IL-6 or clinical improvements after fasting were directly related to increases in serum DHEAS. The fasting-induced fall in serum IL-6 may underlie the fall in CRP and ESR observed in RA patients in response to a 7-day fast.

Reduction in serum leptin and IGF-1 but preserved T-lymphocyte numbers and activation after a ketogenic diet in rheumatoid arthritis patients.

OBJECTIVE: To assess the clinical, immunological and hormonal effects of carbohydrate restriction in rheumatoid arthritis (RA) patients via the provision of a ketogenic diet. METHODS: Thirteen RA patients with active disease consumed a ketogenic diet for 7 days, providing the estimated requirements for energy and protein whilst restricting their carbohydrate intake to < 40 g/day. This was followed by a 2-week re-feeding period. Clinical and laboratory evaluations were carried out on days 0, 7 and 21. Changes in serum glucose, beta-hydroxybutyrate (beta-HB), leptin, insulin-like growth factor-1 (IGF-1) and cortisol were also measured at these time points. To study CD4+ and CD8+ lymphocyte responses, mitogen stimulated T-cell activation was assessed in heparinised whole blood via flow-cytometric analysis of CD69 expression. RESULTS: After the 7-day ketogenic diet, there were significant increases in serum beta-HB and cortisol, and significant decreases in body weight, the total lymphocyte count, serum leptin, IGF-1 and glucose. However, with the exception of morning stiffness, there were no significant changes in any of the clinical or laboratory measures of disease activity, or in early T-lymphocyte activation and the absolute numbers of CD4+ and CD8+ cells. CONCLUSION: In RA patients several of the metabolic and hormonal responses to a ketogenic diet, such as a fall in serum IGF-1 and leptin, resemble those which occur in response to acute starvation. However, the clinical and immunological changes which occur in response to acute starvation do not take place with a ketogenic diet and thus may be dependent upon energy and/or protein restriction.

Decreased CD4+ lymphocyte activation and increased interleukin-4 production in peripheral blood of rheumatoid arthritis patients after acute starvation.

We investigated the effects of acute starvation on mitogen-induced T-cell activation and Th1/Th2 cytokine responses in rheumatoid arthritis (RA) patients. Ten RA patients with active disease underwent a 7-day fast followed by a 2-week refeeding period. Immunological, hormonal, laboratory and clinical evaluations were carried out on days 0, 7 and 21. Using flow cytometry, mitogen-stimulated T-cell activation was assessed in fresh heparinised blood via analysis of CD69 expression. Production of Th1 (interferon-gamma) and Th2 (interleukin-4, IL-4) cytokines was also assessed by ELISA. The 7-day fast significantly decreased the erythrocyte sedimentation rate, C-reactive protein level, joint count, morning stiffness, body weight, CD4+ and CD8+ counts and CD69+ expression on mitogen stimulated CD4+ lymphocytes. A significant increase in mitogen-induced IL-4 production after fasting was found. The fast markedly reduced serum leptin and insulin-like growth factor-1 concentrations. No significant differences occurred in serum cortisol or prolactin before and after fasting. Decreases in CD4+ lymphocyte activation during fasting correlated with decreases in body weight. Our results suggest that the clinical and laboratory improvements in fasting RA patients may be attributed to decreased CD4+ T-cell activation and an increase in the number and/or function of IL-4-producing Th2 cells. Factors associated with loss of body weight during acute starvation appear to have an inhibitory effect on CD4+ lymphocyte activation.

Changes in plasma free fatty acid concentrations in rheumatoid arthritis patients during fasting and their effects upon T-lymphocyte proliferation.

OBJECTIVE: To measure whether changes in the concentrations of circulating free fatty acids (FFAs) after a 7 day fast in rheumatoid arthritis (RA) patients would inhibit in vitro T-lymphocyte proliferation. METHODS: The concentration and composition of plasma FFAs were measured in nine RA patients at the conclusion of a 7 day fast. A FFA mixture was made up based on these findings (20% linoleic, 43% oleic, 10% stearic, 27% palmitic acid). Mitogen-induced lymphocyte proliferative responses were measured after co-culture of peripheral blood mononuclear cells (PBMC) from healthy individuals in the presence of increasing concentrations of this FFA mixture (from 0 to 2000 microM) and in the presence of FFA mixtures where the relative proportions of fatty acids varied. RESULTS: Both the concentration of the FFA mixture and the ratio between the unsaturated and saturated fatty acids significantly influenced in vitro lymphocyte proliferation (P<0.0001). Unexpectedly, the highest concentrations of the FFA mixture increased lymphocyte proliferation. At equimolar concentrations (600 microM), manipulating the amounts of oleic and linoleic fatty acids relative to stearic and palmitic fatty acids had a potent inhibitory effect upon lymphocyte proliferation. CONCLUSION: Fasting-associated increases in total plasma FFA concentrations do not inhibit, but rather enhance, in vitro lymphocyte proliferation. An inhibitory effect could only be achieved by manipulating the balance between the unsaturated and saturated fatty acids.

Passive dosimetry using detector tubes.

Detector tubes for toluene were cut to produce a nominal 0.5 cm orifice above the indicator material, and exposed to known vapor concentrations. The time needed to reach a pre-determined stain length by simple diffusion was measured. Calibration charts were prepared for time versus concentration for a 1 mm stain, as well as for various stain lengths. Tests were performed to determine the effect of increasing the orifice length and of diffusion through the glass wool plug. Each of these parameters resulted in less reliable concentration measurements than tubes of relatively shorter orifice length having no glass wool plug. Diffusion theory was used to develop theoretical calibration charts for comparison with experimental results, with the former underestimating necessary for appearance of the experimentally observed stains. The use of detector tubes having an orifice length of 0.5 cm as passive dosimeters is shown to be highly feasible based on experimental results.

Air sampling and analysis in a rubber vulcanization area.

Results of sampling and analysis of air in a rubber vulcanization area are described. Organic compounds were collected on activated charcoal, desorbed with carbon disulfide and analyzed by gas chromatography. Several previously identified substances were quantitated, including styrene, toluene, ethylbenzene, and several oligomers of 1,3-butadiene. Concentrations ranged from 0.007 to 1.1 ppm.

Health aspects of the curing of synthetic rubbers.

A commonly used tread rubber formulation was cured in the laboratory under conditions simulating vulcanization in the Bag-O-Matic press. Volatile emissions were collected on charcoal and analyzed by combined GC-mass spectrometry. The compounds identified were either contaminants present in the raw material or reaction products. Some of these compounds were also identified in charcoal tube samples collected in the atmosphere of the industrial operations. Estimates based on the loss of weight of rubber during curing were used to predict airborne concentrations and compared to the concentrations actually found. The literature of the toxicity of raw materials and effluents was reviewed, and no acute or chronic toxicological effects would be anticipated. Information concerning potential carcinogenicity was not available and could not be evaluated.

A model for deposition of fibers in the human respiratory system.

A mathematical model for estimating lung deposition of fibers is described. It is based on the aerodynamic behavior of thin straight rods. Predicted deposition values for rods of various equivalent aerodynamic diameters and lengths, for each of three tidal volumes and for each of three respiratory system compartments are reported.