Beneficial health effects of exercise--the role of IL-6 as a myokine

It is not clear how contracting skeletal muscles mediate the numerous and diverse metabolic and physiological effects that are beneficial for health. Researchers have searched for a muscle-contraction-induced factor - an 'exercise factor' - that mediates some of the exercise effects in other tissues such as the liver and adipose tissue. In our search for such a factor, we encountered the cytokine interleukin (IL)-6, which is produced by contracting muscles and released into the blood. We propose that muscle-derived IL-6 meets the criteria of an exercise factor and that such classes of cytokine should be named 'myokines'. The discovery of contracting muscle as a cytokine-producing organ creates a new paradigm: skeletal muscle as an endocrine organ. By contracting, it stimulates the production and release of myokines that can influence metabolism in tissue and organs. Newly identified myokines and their receptors could serve as targets in the treatment of metabolic disorders and other diseases.     

Warfarin dose and INR related to genotypes of CYP2C9 and VKORC1 in patients with myocardial infarction

Objectives

To analyse the effects of rosiglitazone administered at different times on neointimal formation in hypercholesterolemic rabbits following vascular injury.

Methods

Thirty-nine rabbits on a hypercholesterolemic diet were included. The animals underwent balloon catheter injury to the right iliac artery on day 14. They were divided into three groups as follows: control group, 13 rabbits without rosiglitazone; group I, 13 rabbits treated with rosiglitazone (3 mg/Kg body weight/day) for 28 days after the vascular injury; and group II, 13 rabbits treated with rosiglitazone (3 mg/Kg body weight/day) during all the experiment (42 days). Histological analysis was done by an experienced pathologist who was unaware of the rosiglitazone treatment. Histomorphometric parameters were performed by calculation of the luminal and intimal layer area, and intima/media layer area ratio (the area of the intimal layer divided by the area of the medial layer).

Results

Intimal area was significantly lower in group II vs. CG (p = 0.024) and group I (p = 0.006). Luminal layer area was higher in group II vs. CG (p < 0.0001) and group I (p < 0.0001). Intima/media layer area ratio was equal between CG and group I. Intima/media layer ratio area was significantly lower in group II vs. control group (p < 0.021) and group I (p < 0.003). There was a significant reduction of 65% and 71% in intima/media layer area ratio in group II vs. control group and group I, respectively.

Conclusion

Pretreatment with rosiglitazone in hypercholesterolemic rabbits submitted to vascular injury significantly reduces neointimal formation.     

Coping with life-threatening events was associated with better self-perceived health in a naval cross-sectional study

Objective

We studied the relationship between experiencing and coping with life-threatening events and self-perceived health in navy personnel operating mainly under peaceful circumstances.

Methods

The data were collected in a cross-sectional study from a questionnaire sent by mail at the end of 2002 to all employees in the Royal Norwegian Navy (N=3878) as part of a general health study. Both military and civilian personnel with different types of work on ships and ashore participated in the study. Logistic regression analyses were performed to study the relationship between the number of life-threatening events, occupational status, sex, age, and the extent of putting these events behind. The possible trends between the degree of putting the events behind and each of the eight SF-36 scales were calculated by bivariate correlations.

Results

Military personnel had experienced life-threatening events more often than civilians, but the military personnel appeared 5.5 times more likely to have put such events behind themselves than the civilians. The extent of having put life-threatening events behind oneself was clearly correlated to self-perceived health as measured by the SF-36 subscales bodily pain, general health, vitality, social functioning, role-emotional, and mental health. These associations had linear appearances.

Conclusion

Navy personnel who have experienced a life-threatening event and have not been able to put this event behind them are more likely to report a reduced self-perceived health.     

A second prophylactic MHC-mismatched bone marrow transplantation protects against rat acute myeloid leukemia (BNML) without lethal graft-versus-host disease

BACKGROUND: We have employed a rat model for human acute myeloid leukemia, a promyelocytic leukemia in the BN rat strain (BNML), to develop new protocols for immunotherapy in combination with allogeneic bone marrow transplantation (alloBMT). The status of mixed chimerism in allotransplanted rats provided an opportunity for immunotherapy using alloreactive donor cells. In addition to T or natural killer (NK) cells, we introduced a second infusion of bone marrow cells as prophylactic donor lymphocyte infusions (DLI) to test whether an effective graft-versus-leukemia (GVL) response could be obtained without clinical graft-versus-host disease (GVHD). METHODS: BN rats were sublethally irradiated and transplanted with T-cell depleted bone marrow cells from either fully major histocompatibility complex (MHC)-mismatched (PVG) donor rats or MHC-matched (PVG.1N) as controls. Seven days after transplantation, rats were given 500 leukemic cells to mimic minimal residual disease. Additional cellular therapy was given at day +7. The efficiency of DLI was monitored by chimerism analysis in peripheral blood. RESULTS: Rats receiving infusions of NK cells succumbed to leukemia. T-DLI induced complete donor T-cell chimerism and lethal GVHD. A second alloBMT protected against leukemia. This effect was dependent on an MHC incompatibility between the donor and host and also on the presence of alloreactive T cells in the second bone marrow inoculum, resulting in an increased, mixed donor T-cell chimerism. CONCLUSION: A second prophylactic transplantation influenced the degree of T-cell chimerism to balance favorably between GVL and GVHD. If applicable to humans, repeated alloBMT may provide a novel approach to leukemia therapy.     

5-Substituted imidazole-4-acetic acid analogues: synthesis, modeling, and pharmacological characterization of a series of novel gamma-aminobutyric acid(C) receptor agonists

A series of ring-substituted analogues of imidazole-4-acetic acid (IAA, 4), a partial agonist at both GABAA and GABAC receptors (GABA = gamma-aminobutyric acid), have been synthesized. The synthesized compounds 8a-l have been evaluated as ligands for the alpha1beta2gamma2S GABAA receptors and the rho1 GABAC receptors using the FLIPR membrane potential (FMP) assay and by electrophysiology techniques. None of the tested compounds displayed activity at the GABAA receptors at concentrations up to 1000 microM. However, the 5-Me, 5-Ph, 5-p-Me-Ph, and 5-p-F-Ph IAA analogues, 8a,c,f,g, displayed full agonist activities at the rho1 receptors in the FMP assay (EC50 in the range 22-420 microM). Ligand-protein docking identified the Thr129 in the alpha1 subunit and the corresponding Ser168 residue in rho1 as determinants of the selectivity displayed by the 5-substituted IAA analogues. The fact that GABA, 4, and 8a displayed decreased agonist potencies at a rho1Ser168Thr mutant compared to the WT rho1 receptor strongly supported this hypothesis. However, in contrast to GABA and 4, which exhibited increased agonist potencies at a alpha1(Thr129Ser)beta2gamma2 mutant compared to WT GABAA receptor, the data obtained for 8a at the WT and mutant receptors were nonconclusive.     

Experimental testing of skin reactions to insulin detemir in diabetes patients naïve to insulin detemir

Background/aims: Sporadic reports on immediate and delayed cutaneous reactions to insulin detemir, a modern insulin analogue, have raised unsupported claims of allergy of type I, III and IV. The purpose of this experimental study using a provocative design was to elucidate the potential mechanisms behind such skin reactions. Material and methods: A total of 40 patients with type 1 diabetes or insulin‐requiring type 2 diabetes, all naïve to insulin detemir, were injected on the thigh with 0.l mL of insulin detemir (Levemir^®) administered with an 8 mm needle at three different depths, i.e. intradermal, subdermal and subcutaneously. Saline was injected as control. Any cutaneous reactions were assessed after 10 and 30 min, after 24 and 48 h and after 7 days. Histopathology of positive reactions on day 7 was obtained. The study was randomized, controlled, double‐blinded, and conducted in accordance with ICH‐GCP guidelines. Blood flow was recorded with the Periflux PF5010, and skin colour (a^*) with the DSMII colorimeter. Results: Clinical reading, flowmetry and colorimetry consistently showed delayed reactions after intradermal insulin injection (35 of 40 patients reacted with mainly weak reactions, P<0.05), peaking after 48 h, contrasting no special reaction immediately after injection, except for reactions attributed to needle trauma. A total of 22 patients reacted on subdermal injection and 21 on subcutaneous injection. Histopathology on day 7 from 22 reactions in 15 patients showed a consistent pattern of inflammation with eosinophilia as typically observed in adverse skin reactions to a variety of medicines. Reactions were interpreted as non‐specific biologic responses to the insulin different from direct toxic actions and classical allergic reaction patterns. Only one person registered itch/discomfort. A prick test vs. histamine reference excluded insulin detemir to be a pharmacological histamine releaser. Thus, provocative testing with insulin detemir produced delayed skin reaction but no immediate reaction. Measurement of circulating insulin detemir‐specific antibodies by RIA before and after 3 months showed no increase. Conclusion: Non‐allergic delayed skin reactions from intradermal and, to a minor degree, subdermal and subcutaneous injections of insulin detemir were frequent in this experimental study and showed a consistent histology pattern of inflammation with eosinophilia. Immediate reactions were not produced. The reactions are unlikely to be specific for insulin detemir, and other insulins should be studied in a similar provocative design.