Effect of implementation of safety measures in tae kwon do competition.

BACKGROUND: Previous reviews of tae kwon do (TKD) tournaments have documented injury rates of 25/1000 to 12.7/100 athlete exposures. Most injuries have been reported to be to the head and the neck and are occasionally very serious. Many of these studies involved high level TKD competitions with minimal safety precautions. Recently, safety measures have been implemented in many TKD competitions. OBJECTIVE: To evaluate retrospectively the incidence of injuries in TKD competitions involving a wide range of participants and featuring extensive safety precautions. METHODS: A total of 2498 participants ranged in age from 18 to 66, included both men and women, and ranged in rank from yellow to black belt. Traumas, defined as any event requiring interaction with medical staff, were documented with respect to mechanism, diagnosis, treatment, and follow up recommendations. An injury was defined as a trauma that prevented a contestant from resuming competition on the day that the trauma occurred, according to National Collegiate Athletic Association criteria. RESULTS: The injury rate was 0.4/1000 athlete exposures. This is lower than reported in previous studies of TKD tournaments and in many other sports. CONCLUSION: TKD tournaments that emphasise limited contact, protective equipment, and medical supervision are relatively safe and compare favourably with other sports.

Effects of acute and repeated oral doses of D-tagatose on plasma uric acid in normal and diabetic humans.

D-tagatose, a stereoisomer of D-fructose, is a naturally occurring ketohexose proposed for use as a low-calorie bulk sweetener. Ingested D-tagatose appears to be poorly absorbed. The absorbed portion is metabolized in the liver by a pathway similar to that of D-fructose. The main purpose of this study was to determine if acute or repeated oral doses of D-tagatose would cause elevations in plasma uric acid (as is seen with fructose) in normal humans and Type 2 diabetics. In addition, effects of subchronic D-tagatose ingestion on fasting plasma phosphorus, magnesium, lipids, and glucose homeostasis were studied. Eight normal subjects and eight subjects with Type 2 diabetes participated in this two-phase study. Each group was comprised of four males and four females. In the first phase, all subjects were given separate 75 g 3-h oral glucose and D-tagatose tolerance tests. Uric acid, phosphorus, and magnesium were determined in blood samples collected from each subject at 0, 30, 60, 120, and 180 min after dose. In the 8-week phase of the study, the normals were randomly placed into two groups which received 75 g of either D-tagatose or sucrose (25 g with each meal) daily for 8 weeks. The diabetics were randomized into two groups which received either 75 g D-tagatose or no supplements of sugar daily for 8 weeks. Uric acid, phosphorus, magnesium, lipids, glycosylated hemoglobin, glucose, and insulin were determined in fasting blood plasma of all subjects at baseline (time zero) and biweekly over the 8 weeks. The 8-week test did not demonstrate an increase in fasting plasma uric acid in response to the daily intake of D-tagatose. However, a transient increase of plasma uric acid levels was observed after single doses of 75 g of D-tagatose in the tolerance test. Plasma uric acid levels were found to rise and peak at 60 min after such dosing. No clinical relevance was attributed to this treatment-related effect because excursions of plasma uric acid levels above the normal range were small and were of short duration. Consistent with earlier observations on fructose, the increase of plasma uric acid was associated with a slight decrease of plasma phosphorus and a slight increase of magnesium. The daily ingestion of D-tagatose for 8 weeks had no effect on fasting plasma magnesium, phosphorus, cholesterol, triglycerides, glycosylated hemoglobin, glucose, and insulin levels. The ingestion of three 25-g doses per day for a period of 8 weeks resulted in varying amounts of flatulence in seven of the eight subjects, and some degree of diarrhea in six subjects. D-tagatose holds promise as a sweetener with no adverse clinical effects observed in these studies.

In vivo antiperoxidative effect of 9-cis beta-carotene compared with that of the all-trans isomer.

It has been implied that the antiperoxidative activity of beta-carotene is important for its ability to prevent malignant and cardiovascular diseases. In vitro studies have shown that 9-cis beta-carotene is a better antioxidant than the all-trans isomer. In the present study the antiperoxidative biopotency of 9-cis beta-carotene was studied in vivo. For three weeks, weanling female rats were fed diets containing 10% fresh or oxidized soybean oil. The experimental diets were supplemented with beta-carotene at 1 g/kg with the synthetic all-trans isomer or with a carotene extract of Dunaliella bardawil containing 75% 9-cis beta-carotene. Both carotene sources prevented to the same extent hepatic and erythrocyte peroxidation associated with the consumption of oxidized oil. However, this beneficial effect was accompanied, in most of the groups, by a reduction in the hepatic carotene stores. Only in the animals fed Dunaliella extract combined with oxidized oil were the hepatic stores of beta-carotene and vitamin A maintained. The enhanced degradation of 9-cis beta-carotene observed in the livers of these animals might indicate that, like the effect observed under in vitro conditions, this isomer has a greater affinity toward free radicals and therefore might be a more efficient antioxidant than the all-trans form under in vivo conditions. The activity of glutathione peroxidase, glucose-6-phosphate dehydrogenase, and glutathione reductase as affected by the two carotene sources was also studied.

Differential effects of serotonin and raphe grafts in the hippocampus and hypothalamus: a combined behavioural and anatomical study in the rat.

Combined with a partial cholinergic deficiency, serotonergic lesions induce severe spatial learning deficits. Serotonergic lesions, however, have additional effects, such as reduced body weight and disruption of thermoregulation, which may be the cause of the observed learning deficits. Restoration of the serotonergic innervation of the hippocampus by raphe grafts reduces these learning deficits. The effects of the grafts may result from a direct support of spatial learning but may also be an indirect result of preventing some of the other effects of serotonergic lesions. In the present study we used raphe grafts to examine the selectivity and specificity of the effects of serotonergic lesions in the rat, and used the behavioural effects as an indication of successful transplantation in order to examine the fine details of such grafts. Raphe grafts in the hippocampus did not prevent the effects of the lesions on body weight, thermoregulation and exploratory behaviour but did minimize the effects of the lesions on spatial learning. In contrast, raphe grafts in the hypothalamus reduced the effects of the lesions on thermoregulation but failed to support learning. The grafted fibres showed termination specificity with the interneurons, which is typical of the serotonergic innervation of the normal hippocampus. The results indicate that the serotonergic innervation of the hippocampus functions locally to support spatial learning. This role of serotonin is independent of its involvement in modulation of body weight, thermoregulation or exploratory behaviour. The results confirm that the modes of serotonergic action in the hippocampus include the selective innervation of specific interneuron subpopulations.

Phosphorylation by protein kinase A of RCK1 K+ channels expressed in Xenopus oocytes.

Phosphorylation-mediated regulation of voltage-gated K+ channels has been implicated in numerous electrophysiological studies; however, complementary biochemical studies have so far been hampered by the failure to isolate and characterize any K+ channel proteins of distinct molecular identity. We used the Xenopus oocyte expression system to study the biosynthesis and phosphorylation by protein kinase A (PKA) of rat brain RCK1 (Kv1.1) K+ channel protein. RCK1 protein was isolated by immunoprecipitation from oocytes injected with RCK1 cRNA and analyzed by SDS-polyacrylamide gel electrophoresis (SDS-PAGE). The channel protein was expressed in the form of several polypeptides. The 57-kDa polypeptide, usually the major constituent, resided both in the cytosol and in the plasma membrane. Its levels were correlated with RCK1 current amplitudes (IRCK1) and upon incubation of the cRNA-injected oocytes with tunicamycin, its molecular weight was decreased and at the same time IRCK1 was reduced. These results suggest that the membranal 57-kDa polypeptides represent functional channels that are N-glycosylated. Furthermore, a study of the phosphorylation of the RCK1 polypeptides revealed that the 57-kDa polypeptide was specifically targeted for phosphorylation by PKA. It could be phosphorylated in vitro by the catalytic subunit of PKA (PKA-CS). In its native state in intact oocytes, the 57-kDa polypeptide was partially phosphorylated and could be further phosphorylated in vivo by addition of a membrane-permeant cAMP analog. Site-directed mutagenesis demonstrated that phosphorylation of a single site on the C-terminus of the channel molecule fully accounts for these phosphorylations.(ABSTRACT TRUNCATED AT 250 WORDS)

9-Cis beta-carotene as a precursor of retinol isomers in chicks.

The possibility that 9-cis beta-carotene serves as a precursor for retinol in general, and particularly for 9-cis retinol, was studied in chicks, in which the 9-cis beta-carotene is preferentially accumulated. One week old chicks were fed a synthetic diet supplemented with 9-cis and all-trans beta-carotene mixtures, in which the 9-cis isomer content was 9, 19.1, 31.2, 40.8, 57.7 or 77.0%. It was found that an elevation in the dietary 9-cis beta-carotene level led to a decrease in the hepatic retinol stores, despite the increased level of total and 9-cis beta-carotene in the liver. HPLC chromatography revealed the presence of all-trans, 13-cis and 9-cis retinol in the livers. A high 9-cis beta-carotene diet brought about a significant, but very small, elevation in the part of the cis retinol isomers relative to the all-trans isomer. It was concluded that 9-cis beta-carotene has a low activity as a precursor of retinol in general. This decreased activity is not due to a low availability of the isomer to the enzymatic cleavage. It seems also that 9-cis beta-carotene is not an efficient precursor of 9-cis retinol.

The effects of serotonin depletion and raphe grafts on hippocampal electrophysiology and behavior.

The involvement of the serotonergic system in spatial learning and a possible correlation between serotonergic modulation of hippocampal electrical activity and spatial learning were studied in rats. Control, partial septal-lesioned (SL), 5,7-dihydroxytryptamine (5,7-DHT)-injected (DHT), double-lesioned (5,7-DHT and SL; DL), and DL rats that were transplanted with embryonic raphe grafts into the hippocampus (RG) were tested in a spatial task in a water maze and in an active avoidance shuttle-box task. The responses of the dentate gyrus (DG) to perforant-path (PP) stimulation were examined in the same rats, under the following conditions: (1) priming stimulation of the PP (testing feedback inhibition), (2) priming stimulation of the commissural pathway (testing feedforward inhibition), (3) during repeated stimulation of the PP at 7 Hz (frequency potentiation), and (4) following tetanic stimulation [long-term potentiation (LTP)]. DL, but not DHT or SL, treatment severely impaired the performance of rats in both reference- and working-memory tasks in the water maze. This effect was not seen in the shuttle box. The ability of the DG to exhibit LTP, which was reduced in the DHT and SL rats, was apparently similar to controls in the DL group, DL, but not DHT or SL alone, resulted in a reduction of inhibition in the DG. Both the behavioral deficits and the reduction in hippocampal inhibition were ameliorated by intrahippocampal raphe grafts. These results indicate that the serotonergic innervation of the hippocampus plays a role in spatial learning when the septohippocampal neurotransmission systems are disrupted. Furthermore, these results suggest that restoration of modulation of hippocampal inhibition, by raphe grafts, underlies the behavioral recovery observed in these rats.

[Optimization of the treatment of patients with hypertensive disease from the rheological viewpoint]. / Optimizatsiia lecheniia bol'nykh gipertonicheskoi bolezn'iu s reologicheskikh pozitsii.

The efficacy of various modes of correcting rheological disorders (membrane-protective agents, laser irradiation, plasmapheresis was compared in hypertensive patients. In 30% of the patients, the conventional antihypertensive therapy was demonstrated to deteriorate hemorheological parameters, which was due to its atherogenic impact on the blood lipid spectrum. Essential phospholipids, laser irradiation, and plasmapheresis, which are supplemented to the multimodality therapy promote a significant improvement of hemorheological parameters, which makes it possible to recommend them for management of hypertensive patients with a stable (essential phospholipids), complicated (laser irradiation), and refractory (plasmapheresis) course.

[Evaluation of the effectiveness of infusion solutions based on electron-microscopic studies]. / Otsenka éffektivnosti infuzionnykh sred po dannym élektronno- mikroskopicheskikh issledovanii.

Two combined hemocorrectors have been developed for the treatment of shock terminal phases. The effectiveness of these infusion solutions was evaluated in the study of the liver and myocardium ultrastructure in experimental animals during the development of ischemic shock and its treatment. It was shown that a combination of the known agents (Rheopolyglucin, lactasol, mannitol and sodium succinate) favourably influenced the structure of the microcirculation bed, but did not affect metabolic disorders typical for a "shock cell". Inclusion into the combined hemocorrector of a molecular autocomplex, a derivative of 1,4-naphthoquinone, producing a membrane-protective effect, has significantly promoted the preservation and recovery of intracellular structures of the liver and myocardium cells.

Riboflavin deficiency and the function and fluidity of rat erythrocyte membranes.

The effect of riboflavin deficiency on the fluidity and function of the red blood cell (RBC) membrane and on the activity of some enzymes involved in antioxidant defense mechanisms was studied. Growing male rats were fed an experimental (riboflavin-deficient) or a control (riboflavin-supplemented) diet. Following 7 wk of feeding, RBC from riboflavin-deficient rats contained higher levels of peroxidation products, most likely due to decreased glutathione reductase activity. An elevation in glutathione peroxidase activity was also observed whereas the activity of catalase and superoxide dismutase was not affected. Membrane fluidity was studied by fluorescence polarization, using 1,6-diphenyl-1,3,5 hexatriene (DPH) as a probe. The fluidity of RBC membranes isolated from riboflavin-deficient rats was significantly lower than that of the controls. This decreased fluidity was accompanied by an increase in the activity of the membrane-bound enzyme acetylcholinesterase. This study demonstrated that a decrease in cells' ability to cope with peroxidative damage as a result of riboflavin deficiency may lead to changes in the fluidity and function of membranes.

[The efficacy of rheopolyglucin-based blood correctors in acute blood loss in rats]. / Effektivnost' gemokorrektorov na osnove reopoligliukina pri ostroi krovopotere u krys.

The efficacy of rheopolyglucin and complex blood correctors based on it was demonstrated in experiments on 86 albino male rats. The main renal functions (glomerular filtration and tubular secretion), determined by radionuclide methods, were restored by means of infusion therapy. The effect was produced by the complex action exerted on the main pathogenetic mechanisms of the process. Rheopolyglucin injected into intact rats and rats subjected to blood loss led to a certain increase of the blood histamine level, but did not induce a shock-like reaction. Infusion of an equal volume of isotonic sodium chloride solution was also accompanied with hyperhistaminemia in some of the rats.

[Influence of agents of infusion-transfusion therapy on the status of kidney function in hemorrhagic shock]. / Vliianie sredstv infuzionno-transfuzionnoUi terapii na sostoianie funktsii pochek pri gemorragicheskom shoke.

The influence of autologous blood, rheopolyglucinum with mannitol and of two combined blood corrigents on tubular secretion (with respect to 131I-hippuran excretion) and glomerular filtration (with the use of 169Yb-DTPA) was studied in experiments on white mice with "irreversible" hemorrhagic shock. It was established that autoblood transfusion led to an insignificant recovery of tubular secretion and glomerular filtration in shock. Rheopolyglucinum with mannitol improved, to some extent, the kidney function, while the combined blood corrigents including rheopolyglucinum, mannitol, crystalloids and sodium succinate contributed to more complete recovery of the kidney function. The highest effect was recorded when the blood corrigent was supplemented by a compound resuming the electron transport along the mitochondrial respiratory chain. The use of the autoblood with combined blood corrigents (1:4) in severe hemorrhagic shock led to the same degree of recovery of tubular secretion and glomerular filtration as combined blood corrigents alone.

[Effect of 1,4-naphthoquinones on lipolysis in hemorrhagic shock]. / Vliianie nekotorykh 1,4-naftokhinonov na lipoliz pri gemorragicheskom shoke.

Derivatives of 1,4-naphthoquinones increased the lipolytic activity of epididymal and perinephric fatty tissues. A compound AK-45 Na at a dose of 30 mg/kg elevated the positive effect of rheopolyglucine on lipid metabolism, contributing to mobilization as well as to consumption of lipids in hemorrhagic shock in rats and rabbits.

[Vascular brain lesions and ischemic heart disease]. / Sosudistye porazheniia mozga i ishemicheskaia bolezn' serdtsa.

The role of essential hypertension in the pathogenesis of cerebral vessel disorders (not only hemorrhagic, but also ischemic) is greater than in the pathogenesis of the heart ischemic disease. An analysis of the evidences left by ancient doctors, when compared with statistical data of our time, gives one grounds to believe that cerebral hemorrhages have been a rather common disease, at least, since the time of the antique civilization of Greece and Rome, whereas ischemic heart disease has become a widespread disease among the population of the developed countries only in our time. This makes it possible to assume that the role of essential hypertension and that of atherosclerosis are not equal in the "diseases of civilization", if the diseases of today's developed society are meant.

Clinical applications of biofeedback: implications for psychiatry.

The authors briefly describe biofeedback techniques such as EMG feedback, temperature feedback, and heart rate feedback, along with reports from the literature about their application to specific problems such as subvocalization while reading, Raynaud's disease, cardiac arrhythmias, and epilepsy. Many clinical applications of biofeedback are aimed at inducing relaxation, a state that has important psychotherapeutic potential. The authors suggest that biofeedback could be used to reduce a patient's general level of arousal or as an adjunct to behavior therapy or insight therapy. While there have been no reports in the literature of any harmful effects secondary to feedback training, the authors caution that some patients may respond negatively to an objectively measured state of relaxation.