Exposure to Cryogenic Temperature and Exercises and Changes in Blood Pressure.

BACKGROUND: Cryotherapy is one of the methods used in physical medicine to achieve analgesic, anti-inflammatory, antiedematous effects and to reduce muscle tension. OBJECTIVE: The aim of the study was to assess the impact of systemic cryotherapy combined with kinesitherapy on systolic and diastolic blood pressure. MATERIALS AND METHODS: A group of 215 individuals of both sexes was selected and submitted to a two-week cycle of the systemic cryotherapy treatment combined with kinesiotherapy. RESULTS: The decrease of average values was observed in systolic and diastolic blood pressure. In the case of systolic blood pressure there was a significant decrease of average value from 125 mm Hg on the first day to the value of 121.7 mmHg on 10th treatment day. In the case of diastolic blood pressure a significant decrease in the average blood pressure value of 80 mmHg to a value of 76.8 mmHg was observed in the further course of treatment. CONCLUSION: One cryostimulation treatment causes a decrease of the average values of the systolic blood pressure and diastolic blood pressure while the series of 10 treatments leads to stabilization of pressure. Stabilization of systolic blood pressure in men was significantly slower than in women, achieving statistically higher mean values. The women were more responsive to applied cryotherapy.

Melatonin and succinate reduce rat liver mitochondrial dysfunction in diabetes.

Mitochondrial dysfunction and an increase in mitochondrial reactive oxygen species in response to hyperglycemia during diabetes lead to pathological consequences of hyperglycemia. The aim of the present work was to investigate the role of a specific functional damage in rat liver mitochondria during diabetes as well as to evaluate the possibility of metabolic and antioxidative correction of mitochondrial disorders by pharmacological doses of succinate and melatonin. In rat liver mitochondria, streptozotocin-induced diabetes was accompanied by marked impairments of metabolism: we observed a significant activation of α-ketoglutarate dehydrogenase (by 60%, p<0.05) and a damage of the respiratory function. In diabetic animals, melatonin (10 mg/kg b.w., 30 days) or succinate (50 mg/kg b.w., 30 days) reversed the oxygen consumption rate V(3) and the acceptor control ratio to those in nondiabetic animals. Melatonin enhanced the inhibited activity of catalase in the cytoplasm of liver cells and prevented mitochondrial glutathione-S-transferase inhibition while succinate administration prevented α-ketoglutarate dehydrogenase activation. The mitochondria dysfunction associated with diabetes was partially remedied by succinate or melatonin administration. Thus, these molecules may have benefits for the treatment of diabetes. The protective mechanism may be related to improvements in mitochondrial physiology and the antioxidative status of cells.

Oxygen-related processes in red blood cells exposed to tert-butyl hydroperoxide.

The correlation between the oxidative processes in tert-butyl hydroperoxide (tBHP)-exposed red blood cells and the reactions of oxygen consumption and release were investigated. Red blood cell exposure to tBHP resulted in transient oxygen release followed by oxygen consumption. The oxygen release in red blood cells was associated with intracellular oxyhaemoglobin oxidation. The oxygen consumption proceeded in parallel with free radical generation, as registered by chemiluminescence, but not to membrane lipid peroxidation. The oxygen consumption was also observed in membrane-free haemolyzates. The order of the organic hydroperoxide-induced reaction of oxygen release with respect to the oxidant (tBHP) was estimated to be 0.9 +/- 0.1 and that of the oxygen consumption reaction was determined to be 2.4 +/- 0.2. The apparent activation energy values of the oxygen release and oxygen consumption were found to be 107.5 +/- 18.5 kJ/mol and 71.0 +/- 12.5 kJ/mol, respectively. The apparent pKa value for the functional group(s) regulating the cellular oxyHb interaction with the oxidant in tBHP-treated red blood cells was estimated to be 6.7 +/- 0.2 and corresponded to that of distal histidine protonation in haemoprotein. A strong dependence of tBHP-induced lipid peroxidation on the oxygen concentration in a red blood cell suspension was observed (P50 = 32 +/- 3 mmHg). This dependence correlated with the oxygen dissociation curve of cellular haemoglobin. The order of the membrane lipid peroxidation reaction with respect to oxygen was found to be 0.5 +/- 0.1. We can conclude that the intensity of the biochemical process of membrane lipid peroxidation in tBHP-exposed erythrocytes is controlled by small changes in such physiological parameters as the oxygen pressure and oxygen affinity of cellular haemoglobin. Neither GSH nor oxyhaemoglobin oxidation depended on oxygen pressure.

Histone deacetylase inhibitor NVP-LAQ824 has significant activity against myeloid leukemia cells in vitro and in vivo.

NVP-LAQ824 is a novel potent hydroxamic acid-derived histone deacetylase inhibitor that induces apoptosis in nanomolar concentrations in myeloid leukemia cell lines and patient samples. Here we show the activity of NVP-LAQ824 in acute myeloid leukemia cells and BCR/ABL-expressing cells of mouse and human origin, both sensitive and resistant to imatinib mesylate (Gleevec, STI-571). Whereas imatinib inhibited overall cellular tyrosine phosphorylation in Ba/F3.p210 cells, NVP-LAQ824 did not inhibit tyrosine phosphorylation, and did not affect BCR/ABL or ABL protein expression. Neither compound was able to inhibit cellular tyrosine phosphorylation in the imatinib-resistant Ba/F3.p210-T315I cell line. These data taken together suggest that BCR/ABL kinase activity is not a direct target of NVP-LAQ824. Synergy between NVP-LAQ824 and imatinib was demonstrated against BCR/ABL-expressing K562 myeloid leukemia cell lines. In addition, we show that NVP-LAQ824 was well tolerated in vivo in a pre-clinical murine leukemia model, with antileukemia activity resulting in significant prolongation of the survival of mice when treated with NVP-LAQ824 compared to control mice. Taken together, these findings provide the framework for NVP-LAQ824 as a novel therapeutic in myeloid malignancies.

Comparison of melatonin products against USP's nutritional supplements standards and other criteria.

OBJECTIVE: To evaluate and compare the quality of a sample of melatonin products, as measured by the United States Pharmacopeial Convention (USP) General Tests and Assays for Nutritional Supplements (other than Microbial Limits) and certain other tests. DESIGN: Five immediate-release, two sublingual, and two controlled-release products were randomly gathered from a health food store, groceries, and pharmacies in the Baltimore-Washington metropolitan area. MAIN OUTCOME MEASURES: Weight variation, disintegration (not applicable for controlled-release products), and drug dissolution, based on USP standards. Twelve-hour dissolution profiles were obtained from the controlled-release products. All tablets were also evaluated for friability following the USP procedure and for hardness following unofficial procedures. RESULTS: All products passed the weight variation test. Two products showed excessive friability. Three immediate-release products failed both the disintegration and the dissolution tests. One of the three products demonstrated a threefold difference in hardness. One controlled-release product released 90% of melatonin in four hours in the dissolution test; the other released 90% of its content in 12 hours. CONCLUSION: Some products showed evidence of poor formulation and/or poor quality control as indicated by excessive friability, failure to disintegrate and dissolve, and excessive variation in hardness. In vitro release profiles of the two controlled-release products were substantially different. The poor quality of some supplements should be a concern to consumers and health care providers.

Plasma pharmacokinetics and tissue distribution of paclitaxel in CD2F1 mice.

We defined the pharmacokinetics of paclitaxel after i.v., i.p., p.o., and s.c. administration of 22.5 mg/kg to CD2F1 mice. Additional mice were studied after i.v. bolus dosing at 11.25 mg/kg or 3-h continuous i.v. infusions delivered at 43.24 micrograms kg-1 min-1. Plasma was sampled between 5 min and 40 h after dosing. Brains, hearts, lungs, livers, kidneys, skeletal muscles, and, where applicable, testicles were sampled after i.v. dosing at 22.5 mg/kg. Liquid-liquid extraction followed by isocratic high-performance liquid chromatography (HPLC) with UV detection was used to determine paclitaxel concentrations in plasma and tissues. After i.v. administration to male mice, paclitaxel clearance (CLtb) was 3.25 ml min-1 kg-1 and the terminal half-life (t1/2) was 69 min. After i.v. administration to female mice, paclitaxel CLtb was 4.54 ml min-1 kg-1 and the terminal t1/2 was 43 min. The bioavailability of paclitaxel was approximately 10%, 0, and 0 after i.p., p.o., and s.c. administration, respectively. Paclitaxel bioavailability after i.p. administration was the same when the drug was delivered in a small volume to mimic the delivery method used to evaluate in vivo antitumor efficacy or when it was delivered in a large volume to simulate clinical protocols using i.p. regional therapy. Paclitaxel was not detected in the plasma of mice after i.p. delivery of the drug as a suspension in Klucel: Tween 80. Pharmacokinetic parameters were similar after i.v. delivery of paclitaxel at 22.5 and 11.25 mg/kg; however, the CLtb calculated in these studies was much lower than that associated with 3-h continuous i.v. infusions. After i.v. administration, paclitaxel was distributed extensively to all tissues but the brain and testicle. These data are useful in interpreting preclinical efficacy studies of paclitaxel and predicting human pharmacokinetics through scaling techniques.