Kinesio taping with ballistic six plyometric training on speed, accuracy, target and joint proprioception in fast bowlers with glenohumeral instability

Cricket is one of the most popular international sports played worldwide. Ballistic six plyometric training improves throwing activity in throwing sports, improves rotator cuff muscular strength, and prevents and reduces the risk of shoulder injury associated with overhead pitching. Kinesiotaping is used in rehabilitation, as a treatment for sportsrelated injuries, and as a means of injury prevention. The objective of the study was to compare the combined effect of kinesiotaping with ‘ballistic six plyometric training’ and with ballistic six plyometric training alone on speed, accuracy, target and joint proprioception in fast bowlers with mild glenohumeral joint instability. Thirty male semiprofessional fast bowlers in the age group of 20-30 years were included in this study and randomly divided into two groups: group A and group B with 15 players in each group. Group A received kinesiotaping along with ballistic six plyometric training, whereas group B was only given ballistic six plyometric training. Both groups also performed conventional upper extremity workouts. All players were evaluated for bowling speed, accuracy, target and joint proprioception (internal rotation & external rotation) with a radar gun, cricket specific bowling accuracy test, no. of balls hit stump in an over and inclinometer, respectively. Both groups improved significantly at the end of week 8, however, group B showed significant difference for bowling speed, accuracy, target and joint proprioception (P<0.05). Rehabilitation protocol comprising of combined kinesiotaping, plyometrics along with conventional protocol can be beneficial in enhancing performance related variables, i.e. bowling speed, accuracy and target in fast bowlers with mild glenohumeral instability.

4300Strain parameters at rest and after exercise in symptomatically stable patients with improved heart failure - STRESS-HF

Background

Optimal medical therapy (OMT) results in improvement in left ventricular (LV) ejection fraction (EF) and reduction in LV size in approximately 40% of patients of heart failure with reduced ejection fraction (HFrEF). Recent studies have proposed to continue treatment in all patients of this subgroup as improvement in LVEF does not indicate actual myocardial recovery. Global Longitudinal strain (GLS) is more sensitive marker of LV systolic function and better predictor of mortality than LVEF. GLS may identify probable patients in whom the therapy can be minimized or stopped.

Aim

To determine global longitudinal strain at rest and after exercise in patients with idiopathic dilated cardiomyopathy (DCM) who have improved LVEF ≥50% on guideline directed medical therapy (GDMT) and compare with resting & exercising LVEF on 3-dimesional (3D).

Material and methods

This Observational study was conducted in a tertiary care referral hospital, from February 2018 to October 2018. All patients with idiopathic DCM who had a documented LVEF of ≤40% in the past and improved LVEF (LVEF ≥50%) on GDMT were included in the study. Patients with secondary causes of HFrEF, poor echocardiographic window and inability to exercise were excluded from the study. Strain parameters were calculated at rest and after atleast 5 METS of exercise. GLS value of ≥ minus 12.6% was considered as mildly reduced strain, ≤ minus 8% as severely reduced strain and the values in between as moderately reduced strain. Post exercise, drop of >5% in absolute LVEF value or decrease in GLS >15% from baseline was considered as poor myocardial recovery.

Results

A total of 44 patients [mean age of 46.8±13.1 years and 24 males (54.5%)] constituted the study group. At the time of diagnosis, 31 (70.5%) patients were in NYHA class II and the remaining were in class III. Duration of GDMT ranged from 4 to 38 (median 12) months. Following improvement on GDMT, 25 (56.8%) were in class I and rest were in class II. Mean LVEF at diagnosis and after recovery was 33.6±4.9% and 55.1±4.5%, respectively with a mean absolute change in LVEF of 21.3±6.1%. At rest, mean 3D LVEF was 53±3.5% and GLS was −12.3±3.1. Mild, moderate and severely reduced strain was seen in 24 (54.5%), 13 (29.6%) and 7 (15.9%), respectively. After exercise, mean 3D LVEF was 51.5.±4.5% (mean decrease 1.5±2.1%) and mean GLS was −7±4.2% (mean decrease −5.3±4.6%). After exercise, none had a fall of LVEF >5% however 32 (72.7%) had a decrease of >15% in GLS. Seven (15.9%) patients had improvement in GLS, 4 (9.1%) had <15% decrease and 1 (2.3%) showed no change in GLS on exercise. The change in GLS on exercise was significant (p=0.001), but change in 3D LVEF was not significant (p=0.956).

Conclusion

Global longitudinal strain is a better marker for assessing myocardial recovery than LVEF in patients of heart failure with improved ejection fraction.

Acknowledgement/Funding

None

24-hour Arterial Stiffness Monitoring in Kidney Transplant Recipients in the Early Postoperative Period

INTRODUCTION

Laboratory tests and anthropometric assessments are essential in determining the risk for cardiovascular disease in patients after kidney transplantation (KTx). Patients with hypertension and elevated pulse wave velocity (PWV) are at a higher risk of cardiovascular mortality. The purpose of this study was to determine the role of blood pressure, arterial stiffness, and selected laboratory and anthropometric parameters in estimating the risk of cardiovascular disease in KTx patients.

METHODS

A total of 17 KTx patients of the Clinical Department of Gastroenterological Surgery and Transplantation at Central Clinical Hospital of Ministry of the Interior and Administration (MSWiA Hospital) in Warsaw, Poland, were enrolled in this study between 3 to 7 days after undergoing kidney transplantation. Medical records of these patients were reviewed for the selected laboratory parameters. The patients' blood pressure and PWV values were monitored for 24 hours and their body mass index (BMI) values were calculated (BMI ≥ 25.0 is considered overweight).

RESULTS

Hemoglobin concentration showed a negative correlation with PWV (r = -0.6), whereas red blood cell distribution width (RDW) showed a positive correlation with the PWV value (r = 0.29). There was a significant correlation (r = 0.21) between overweight measured via BMI and the PWV values. For results of kidney function blood tests, the estimated glomerular filtration rate (GFR) and creatinine levels showed no significant correlation with 24-hour PWV values (GFR r = -0.03; creatinine r = 0.03).

CONCLUSIONS

The following were shown to be important indices of cardiovascular risk in the evaluated population of KTx patients: age, BMI, blood pressure, PWV, hemoglobin levels, red blood cells, and RDW%.

A multicentric study to evaluate efficacy and safety of cefetamet pivoxyl in lower respiratory tract infections in Indian patients

This multicentric, open label, non-comparative study was designed to evaluate the extended spectrum of third generation oral cephalosporin, cefetamet pivoxyl in the treatment of patients with lower respiratory tract infections. This study was conducted among 111 patients with clinical, radiological and bacteriological findings consistent with the diagnosis. After obtaining written informed consent, patients were given cefetamet 500 mg tablet twice a day for 7 days. Cefetamet consistently decreased all clinical signs and symptoms at post-therapy visit. All the treated patients were either cured or improved. Cefetamet was well tolerated with a low incidence of drug related adverse events. The findings of this study indicate that cefetamet pivoxyl was well tolerated and is suitable option for the treatment of patients with lower respiratory tract infection.

Transformed target cell-derived superoxide anions drive apoptosis induction by myeloperoxidase

Myeloperoxidase induces apoptosis in src- or raxs-transformed fibroblasts, but not in parental nontransformed fibroblasts. This selectivity seems to be based on superoxide anion production by transformed cells, a recently described characteristic feature of transformed cells. Myeloperoxidase-mediated apoptosis induction is inhibited by SOD, catalase, 4-aminobenzoyl hydrazide, taurine and DMSO. This pattern of inhibition allows us to conclude that transformed cell derived superoxide anions dismutate to hydrogen peroxide, which fosters HOCl formation by myeloperoxidase. Hydrogen peroxide formation thereby is the rate-limiting step and depends on the cell density. In a second step, HOCl interacts with superoxide anions to yield the highly reactive apoptosis inducing hydroxyl radical. This conclusion was verified through selective apoptosis induction in transformed cells by direct addition of HOCl, which was also inhibited by SOD and DMSO. Our findings demonstrate a specific interplay between target cell derived superoxide anions and MPO during selective apoptosis induction.

Target cell-derived superoxide anions cause efficiency and selectivity of intercellular induction of apoptosis

Transformed fibroblasts are specifically eliminated by their nontransformed neighbors through intercellular induction of apoptosis. This process depends on the number of nontransformed effector cells and on the local density of transformed target cells. Intercellular signalling is inhibited by SOD (a scavenger of superoxide anions), taurine (a scavenger of HOCl), 4-aminobenzoyl hydrazide (a mechanism-based inhibitor of peroxidase), DMSO (a hydroxyl radical scavenger), and two inhibitors of NO synthase. Therefore, selective apoptosis induction seems to be based on superoxide anion production by transformed cells, their spontaneous dismutation to hydrogen peroxide, and HOCl generation by a novel effector cell-derived peroxidase. HOCl then interacts with target cell-derived superoxide anions to yield hydroxyl radicals. Due to the short diffusion pathway of superoxide anions, hydroxyl radical generation is confined to the intimate vicinity of transformed cells. In parallel, NO derived from effector cells interacts with superoxide anions of target cells to yield the apoptosis inducer peroxynitrite. Reconstitution experiments using transformed or nontransformed cells in conjunction with myeloperoxidase, HOCl, or an NO donor demonstrated that superoxide anions generated extracellularly by transformed cells participate in intercellular signalling and at the same time determine transformed cells as selective targets for intercellular induction of apoptosis.

Arguments against the significance of the Fenton reaction contributing to signal pathways under in vivo conditions

One of the common explanations for oxidative stress in the physiological milieu is based on the Fenton reaction, i.e. the assumption that radical chain reactions are initiated by metal-catalyzed electron transfer to hydrogen peroxide yielding hydroxyl radicals. On the other hand - especially in the context of so-called "iron switches" - it is postulated that cellular signaling pathways originate from the interaction of reduced iron with hydrogen peroxide. Using fluorescence detection and EPR for identification of radical intermediates, we determined the rate of iron complexation by physiological buffer together with the reaction rate of concomitant hydroxylations of aromatic compounds under aerobic and anaerobic conditions. With the obtained overall reaction rate of 1,700 M(-1)s(-1) for the buffer-dependent reactions and the known rates for Fenton reactions, we derive estimates for the relative reaction probabilities of both processes. As a consequence we suggest that under in vivo conditions initiation of chain reactions by hydroxyl radicals generated by the Fenton reaction is of minor importance and hence metal-dependent oxidative stress must be rather independent of the so-called "peroxide tone". Furthermore, it is proposed that - in the low (subtoxic) concentration range - hydroxylated compounds derived from reactions of "non-free" (crypto) OH radicals are better candidates for iron-dependent sensing of redox-states and for explaining the origin of cellular signals than the generation of "free" hydroxyl radicals.

Assaying for hydroxyl radicals: hydroxylated terephthalate is a superior fluorescence marker than hydroxylated benzoate

Generation of hydroxyl radicals in terephthalate (benzene-1,4-dicarboxylic acid) solution yields fluorescent 2-hydroxy-terephthalate. The reaction product is stable for hours and can readily be assessed using standard fluorimeters. The efficiency, i.e. the relative increase of fluorescence per *OH radical, is about three times higher than that of the formation of salicylate (2-hydroxy-benzoate) from benzoic acid and approximately hundred-fold higher than that of the hydroxylation of phenylalanine. As the terephthalate molecule is symmetric with respect to ring-hydroxylation, only one isomer is formed; hence, mechanistic interpretation of the hydroxylation reaction is facilitated. The scavenging rate constant of terephthalate for *OH yielding the hydroxycyclohexadienyl adduct as first intermediate is close to the diffusion controlled limit (k = 3.3 x 10(9) M(-1) s(-1)). Therefore, competition of the detector molecule with biomolecules being present under physiological conditions is expected to be efficient. The assay can be used to detect 'free' *OH radicals produced by the radiolysis of water as well as 'hydroxyl analogous species' that have been suggested to arise from the interaction of complex-bound reduced metal with either oxygen or hydrogen peroxide, e.g. from Fenton reactions. Based on calibration with radiolytically generated hydroxyl radicals the detection limit of the method is estimated to be around 50 nmol/dm3. Terephthalate is classified non-toxic and hence may also prove useful for microdialysis and continuous flow experiments as observation of fluorescence is 'non-destructive' and the reporter substance does not necessarily have to be subjected to HPLC.

Phagocytic killing of microorganisms by radical processes: consequences of the reaction of hydroxyl radicals with chloride yielding chlorine atoms

Chloride anions and hydrogen peroxide serve as substrates for myeloperoxidase (MPO) in order to produce hypochlorous acid (HOCl) as one of the major killing agents of phagocytic leukocytes. Apart from this role of being a substrate for the MPO-reaction the chloride anion has been considered as unreactive and has not been implicated in radical reactions which contribute to the killing process. From the inherent reactivities of the pertinent radicals (as determined by pulse radiolysis experiments), the great abundance of chloride, and the most probable distribution of reactants within the phagosome, we deduce estimates for the average life-time and free diffusion path-length in this milieu and arrive at a model according to which chloride ions enter into radical chains and influence the killing of ingested bacteria to an extraordinarily high extent. We propose that hydroxyl radicals--despite some controversial arguments in the literature--may still be considered as important contributors to cell killing especially since we show that their reactions are made more effective by producing chlorine radicals in a cyclic process. We furthermore present arguments how the phagocyte may protect itself from harmful actions of HOCl and H2O2 after the superoxide-generating activity of NADPH oxidase is turned off.

Radical functions in vivo: a critical review of current concepts and hypotheses

Most of the basic knowledge about radical reactions comes from radiation chemical studies in vitro. In view of the rapidly increasing knowledge on radical reaction in vivo, it is important to reconcile the fundamental physico-chemical reaction characteristics of radicals with the need to explain their alleged biological effects. Severe problems in the understanding of their in vivo action remain unsolved. An example is phagocytosis, which seems to be a paradigm of a 'deleterious' radical process. The exact mechanism is not clear; so it is an open question whether the intruder is eventually killed by radicals (like OH) or by endproducts of radical reactions (like H2O2 and/or HOCl). It is even more difficult to understand signalling by radicals: owing to their chemical nature they are 'unspecifically' reacting species--they withdraw or add electrons--and thus their reactions are governed by redox-properties. Since all radicals have different redox characteristics and different molecular shapes, the usual key-and-keyhole picture for molecular interaction does not apply, as there, is no reactive site conceivable which has the property of reacting with radicals 'specifically. Our intent in this article is: (i) to briefly review some fundamental characteristics of in vitro radical reactions, (ii) to extrapolate from this to the conditions in vivo, and (iii) to discuss current hypotheses concerning the redox-regulation of cellular signalling. This leads us to the tentative conclusion that radicals per se must be tolerated by the cell and do not threaten its life, if they stay below a certain concentration limit. The main biological implication of radical-reactions seems to be that the cell derives signals from the balance of oxidative versus reductive processes and that radicals may interact with pathways of intra- and intercellular communication.

Hydrogen peroxide protects yeast cells from inactivation by ionizing radiation: a radiobiological paradox

PURPOSE

To elucidate mechanisms of the interaction of hydrogen peroxide with chloride-derived cytotoxins under steady-state irradiation conditions and to determine the effects on cell viability.

MATERIALS AND METHODS

Yeast cells were suspended in phosphate-buffered saline and exposed to 60Co gamma-irradiation under different conditions. The colony-forming ability was determined.

RESULTS

Irradiation of PBS produces H2O2 and HOCl simultaneously. Under slightly acidic conditions and low oxygen tension the yield of HOCl exceeds that of H2O2 while at physiological pH and normoxic conditions H2O2 exceeds HOCl. Both substances react with each other rapidly in a pH-dependent way, even during an irradiation that lasts several seconds. As HOCl is about 1000-fold more toxic than H2O2 to the strain of Saccharomyces cerevisiae used in these experiments, it is evident that in an irradiation that produces more HOCl than H2O2 the radiation-induced damage will be large. If, in contrast, the cells are irradiated under conditions in which H2O2 production predominates, the damage will be small. One would therefore predict that addition of hydrogen peroxide to a cell suspension prior to irradiation should result in protection for suspended cells if H2O2 interferes with the generation of HOCl and thereby inactivates this more powerful toxin. Our data show that addition of H2O2 in sublethal concentration decreases radiation-induced cell death to the level that is found in chloride-free solution, i.e. depending on pH, reduces it by a factor of > or = 3.

Radiation chemistry of physiological saline reinvestigated: evidence that chloride-derived intermediates play a key role in cytotoxicity

Contrary to common belief, hydrogen peroxide (H2O2) and hypochlorite (HOCl) are not produced continuously and independently during the irradiation of buffer solution containing chloride. Different buildup and decay reactions are involved in a complex interaction of these substances during irradiation. Which of the species predominates is determined by the parameters of the solution. The amount of either compound detectable after irradiation depends on the dissolved gas (O2, N2O or N2), on the pH value and to some extent on the presence of catalytic metals: Under slightly acidic conditions, low oxygen content and high generation rates of OH radicals, the only detectable species is hypochlorite; at high oxygen content and at pH values in the physiological range, hydrogen peroxide is the main detectable product. However, H2O2 and HOCl react with each other in a pH-dependent way, yielding the stable products O2 and Cl-. This reaction limits the expected lifetime of both species in aqueous solution to some tens of seconds. Therefore, analysis of the sample solution after irradiation determines only the substance that was present in greater relative concentration at the termination of irradiation. Such analysis, however, does not allow conclusions about the processes that occurred during irradiation. We have investigated the decay and formation reactions of H2O2 and HOCl under all relevant irradiation conditions and found evidence that the formation and further reaction of HOCl-, the precursor of HOCl, is of central importance even in cases where no significant amounts of H2O2 or HOCl are detectable after irradiation. We discuss the consequences of these results for the cytotoxicity observed after irradiation of cells suspended in physiological saline and conclude that analogous processes must also be relevant for irradiations under in vivo conditions.

Radiation-induced cell killing is highly dependent upon buffer treatment (filtration compared to autoclaving) due to metal-catalyzed formation of hypochlorite: a cautionary note

Buffer solutions used in experiments in radiation biology may be sterilized by either autoclaving or filtration. We show here that for phosphate-buffered saline such differences in buffer treatment may result in widely differing dose-effect curves for cell killing. The temperature-dependent transformation of monophosphate ions into di- or polyphosphate evidently proceeds to an appreciable extent upon autoclaving the buffers at 120 degrees C for 10 to 20 min. This increases the capability of the buffer to chelate spurious metal contaminations and, as a consequence, to reduce the amount of cytotoxic hypochlorite being produced. Depending on conditions of buffer treatment we have observed dose modification factors for the colony-forming ability of yeast cells up to the order of 3. Thus effects due to buffer treatment might easily outweigh the effect which the experiment was originally designed to determine. We strongly advise, therefore, that results of parallel sets of experiments in which different methods of buffer sterilization have been used should not be compared directly.

Kinetic and spectroscopic studies on a superoxide dismutase from Propionibacterium shermanii that is active with iron or manganese: pH-dependence

Kinetic studies were performed on the superoxide dismutases isolated from the anaerobic bacterium Propionibacterium shermanii as active enzymes with either iron or manganese, which were naturally incorporated into the same molecule depending on the metal supply. Both the Fe- and Mn- forms showed decreasing activity with increasing pH. This suggests the protonation of some groups near the metal, possibly a metal-bound water molecule. Thus the kinetic behaviour of this superoxide dismutase is much more dependent on the protein structure than on the metal incorporated into the active site. The secondary structures of both forms were not influenced by variations in pH, whereas the EPR spectra of the Fe-superoxide dismutase changed as a function of pH. The EPR spectra apparently consist of two overlapping species. Steady-state experiments proved that all iron-containing species show catalytic activity, but the species predominating in the alkaline pH range displays a lower reaction rate. The Michaelis constant and maximal turnover number for the Fe-superoxide dismutase were determined polarographically as Km = 0.54 mmol/l and Vmax. = 2000 mol.s-1 at pH 9.5. These data indicate that, in anaerobic bacteria under physiological conditions, the superoxide dismutase is not saturable with O2-. and the catalytic activity is similar to that of metal-specific Fe- or Mn-superoxide dismutases from aerobic organisms.

Reactions of hydrogen peroxide with superoxide dismutase from Propionibacterium shermanii--an enzyme which is equally active with iron or manganese--are independent of the prosthetic metal

Propionibacterium shermanii contains a single constitutive superoxide dismutase (SOD) which is active with either iron or manganese incorporated in the same protein moiety. Copper and cobalt can also be incorporated by the bacteria in the active center of the SOD under conditions of metal deficiency, but in this case the enzyme is enzymatically inactive. In contrast to other bacterial SODs, the Fe-SOD of P. shermanii remains highly resistant to inactivation by hydrogen peroxide, as does Mn-SOD. Both SOD types cannot be distinguished by their inactivation patterns. Incubation with hydrogen peroxide results in a concentration- and time-dependent decrease in tryptophan fluorescence, independent of the metal present in the active center. Moreover, the Fe-SOD shows a time-dependent decrease in spin concentration after addition of hydrogen peroxide, which reflects alterations in the environment of the metal rather than a reduction of Fe3+ to Fe2+. No obvious correlations exist, however, between these effects and the enzymatic activity of the enzyme. The resistance of the SODs from P. shermanii to inactivation by hydrogen peroxide seems to be caused by the fact that a tryptophan residue near the metal-chelating histidine-75--which is present in all Fe-SODs being rapidly inactivated by this agent--is exchanged for valine.

Signalling by O2-. and NO.: how far can either radical, or any specific reaction product, transmit a message under in vivo conditions?

With regard to the stability of the NO. radical as a chemical entity, it is without doubt able to serve as an intra- as well as an intercellular messenger. The radical O2-., in contrast, does not seem to be suited to far-range signalling in the vascular system. Its short chemical half-life, which is limited by the presence of various reactive blood constituents to below 50 ms, results in a free diffusion path length of less than 40 microns, i.e. only the distance between just a few cells. While accelerated 'downstream' transport by arterial blood may help to extend the action sphere, there is no possibility for O2-. to serve as a signal in an upstream direction. The estimates presented, however, do not invalidate arguments for a possible role of superoxide anions in intra- or pericellular signalling phenomena. Cross-talk between NO.- and O2-.-dependent signal routes, e.g. by peroxynitrite formation, is unlikely to be a relevant process under the conditions which prevail in the vascular system.

On the cytotoxicity of irradiated media. To what extent are stable products of radial chain reactions in physiological saline responsible for cell death?

In a previous publication (Czapski et al. 1992) we reported that HOCl accounts for the toxicity of irradiated phosphate-buffered saline towards Escherichia coli bacterial cells. We have now investigated the respective toxicities towards lambda phage and mammalian cells. For phage, as with bacteria, cytotoxicity of the irradiated media seems to derive from HOCl without detectable contribution of H2O2. Mammalian cells (V79 CHO), in contrast, are more sensitive to H2O2 than to HOCl. Both agents, however, are not able to account quantitatively for the toxicity of irradiated solutions towards V79 cells; a hitherto unidentified chlorine/oxygen derivative--being formed in the sub-micromolar concentration range--is suggested to be responsible for toxicity in the case of eukaryotes.

Radical intermediates during the oxidation of nitropropanes. The formation of NO2 from 2-nitropropane, its reactivity with nucleosides, and implications for the genotoxicity of 2-nitropropane

The chemistry of the nonenzymatic oxidation of the rat liver carcinogen, 2-nitropropane, and its anionic form, propane-2-nitronate, was investigated using pulse radiolysis and EPR/spin trapping with 3,5-dibromo-4-nitrosobenzenesulfonic acid as the trapping agent. The results suggest that, following initial oxidation to a secondary alkyl radical, propane-2-nitronate is effectively degraded in a peroxidative chain reaction with the intermediary formation of peroxyl and NO2.radicals. The latter radical was shown to react appreciably fast with ribonucleosides, deoxyribonucleosides, and guanosine nucleotides. It is proposed that nonenzymatic formation of NO2.radicals after enzymatic oxidation of propane-2-nitronate to the corresponding secondary alkyl radical accounts for the induction of DNA damage observed after exposure of rats to 2-nitropropane.

Direct and indirect measurements of oxygen radicals

Instead of covering the available detection methods in detail it is attempted to highlight the ambiguities inherent in oxygen radical detection under in vivo conditions. Due to physicochemical properties of the oxygen molecule, all organic matter is bound to autoxidize. From this it follows that a certain 'background' level of oxygen radical production will always be present and that it may be difficult to differentiate between inherent and induced oxygen radical production. Radicals by their very nature react 'unspecifically'. This infers that it is difficult to identify them unequivocally. The most common methods for oxygen radical detection are briefly mentioned.

Relation of childhood malnutrition to parental education and mothers' nutrition related KAP

Severely malnourished children (26), weight for age 55.27 +/- 3.17, were identified in a colony of predominantly Muslim urban slum dwellers of low economic status. An equal number of normally nourished children matched for age, sex and per capita income were identified. A strong relation was found between nutritional status of the subjects and educational level of their mothers (P less than 0.025). Father's education was unrelated to childrens' nutritional status. A thirty seven point questionnaire was administered to the mothers to record their nutritional knowledge, attitudes and practices (KAP). Analysis revealed that better KAP in relation to 16 of these 37 questions was not associated with better nutritional status. Seven questions were found to have only a weak association. The remaining 14 questions were identified as important for a nutrition education programme. Comparison of nutritional KAP score based on these 14 questions in case of mothers of normal and severely malnourished children revealed a significantly higher score in the former. Questions related to growth monitoring and breast feeding were not found to be important. No significant association was found between mothers' KAP and educational level. It is concluded that (i) Maternal education and KAP are significantly and independently associated with childrens' nutritional status. (ii) The content areas of knowledge, attitudes and practices significantly associated with nutritional status pertain to nutritional requirements of children, nutritional value of foods, immunisation, hygiene, oral rehydration and diarrhea.

An expanded function for superoxide dismutase

alpha-Hydroxyalkylperoxyl radicals were generated from the primary and secondary alcohols methanol, ethanol and 2-propanol in N2O/O2-saturated aqueous solutions by pulse radiolysis. These radicals reduced a ferric iron porphyrin complex, tetrakis-(4-N-methylpyridyl)porphine, with diffusion-controlled rate constants. The extreme sensitivity of the shift of the Soret absorption band in this reaction was used to determine, by competition kinetics, the reactivity of the peroxyl radicals with different proteins. Only native Cu,Zn-superoxide dismutase and metallothionein showed competitive behavior, with SOD exhibiting rate constants close to the dismutation rate for O2-. Metallothionein was slower by a factor of 30 with hydroxymethylperoxyl radicals. We propose, that SOD has unique properties of the protein surface in addition to the prosthetic copper site, having possibly evolved as a 'general-purpose radical-scavenging protein'.

Calcium in lipid peroxidation: does calcium interact with superoxide?

Using a pulse radiolysis approach to generate and observe superoxide anions (O2-.) in the absence and presence of calcium, we have attempted to verify the recent hypothesis of Babizhayev (Arch. Biochem. Biophys. 266, 446-451, 1988) of a Ca2(+)-O2-. interaction during lipid peroxidation. We could not observe rapid scavenging of O2-. or complex formation with Ca2+ to account for an inhibitory effect of this cation on lipid peroxidation. Neither could we agree that the stimulatory effect is due to liberation of catalytic ferrous iron from weak complexes by Ca2+. Drawing on reports in the literature, we propose an alternate explanation for the apparent stimulation of lipid peroxidation by low Ca2+ concentrations. In our view, this is not a direct effect, but reflects independently initiated processes of lipid peroxidation and Ca2+ translocation, which interact subsequently in a synergistic manner. The reported inhibition at high Ca2+ concentrations is considered an artifact as it was observed at levels far in excess of those relevant to animal systems (but not necessarily in some plant compartments).

Reaction of NO with O2-. implications for the action of endothelium-derived relaxing factor (EDRF)

Under physiological pH conditions (pH 7.2-7.4) the rate constant of the reaction NO + O2- yielding peroxonitrite (ONOO-) was determined as k = (3.7 +/- 1.1) x 10(7) M-1 s-1. The decay of peroxonitrite at this pH follows first order kinetics with a rate constant of 1.4 s 1. At alkaline pH peroxonitrite is practically stable. Possible consequences of these reactions for the biological lifetime of EDRF will be discussed.

The mechanism of cytochrome C reduction by alkyl radicals. Evidence for multiple reaction pathways

The reactions of the hydroxyalkyl radicals .CH2OH and (CH3)2.COH with oxidized cytochrome c are for more complex than previously reported. Analysis of the pulse-radiolytic data by kinetic modelling revealed that only about 40% of the alkyl radicals reduce the ferric iron chromophore. Altogether, four different reactions have to be considered for the disappearance of the alkyl radicals, only two of which affect the metal site. The data show that these radicals, similar to the much more reactive hydrated electrons and hydrogen atoms, are capable to react with biological macromolecules in diverse ways.

Oxygen radicals acting as chemical messengers: a hypothesis

Based on a critical reappraisal of the reactions of radicals in a biological milieu, a hypothesis is proposed according to which superoxide anion radicals act as biological messengers rather than as mediators or precursors of cellular damage under oxidative stress conditions.

A critical reevaluation of some assay methods for superoxide dismutase activity

We have compared the direct method of pulse radiolysis to the indirect methods of cytochrome c and nitroblue tetrazolium for assaying the superoxide dismutase activity of a compound. We have shown that with pulse radiolysis, where high concentrations of O2- are generated, the "turnover" rate constant, kcat, can be determined directly, while with the indirect methods, where relatively low steady state concentrations of O2- are formed, the value of kcat determined by these methods, can be orders of magnitude lower than that determined directly. The main reason for the lower values obtained with the indirect methods is due to the fast reoxidation of the reduced compound by molecular oxygen. Additional problems which arise with the use of indirect methods for determining superoxide dismutase catalytic activity are discussed.

Reactions of linoleic acid peroxyl radicals with phenolic antioxidants: a pulse radiolysis study

Linoleic acid peroxyl radicals (LOO.) can be viewed as model intermediates occurring during lipid peroxidation processes. Formation and reactions of these species were investigated in aqueous alkaline solution using the technique of pulse radiolysis combined with kinetic spectroscopy. Irradiation of linoleic acid in N2O/O2-saturated solutions leads to a mixture of peroxyl radical isomers, whereas reaction of 13-hydroperoxylinoleic acid (13-LOOH) with azide radicals in N2O-saturated solution produces 13-LOO. radicals specifically. These peroxyl radicals cannot be observed directly, but their reactions with the two flavonols, kaempferol and quercetin, acting as radical-scavenging antioxidants, produced strongly absorbing aroxyl radicals (ArO.). The same aroxyl radicals were generated by .OH and N3. with rate constants exceeding 10(9) dm3 mol-1 s-1. Applying a reaction scheme that includes competing generation and decay reactions of both LOO. and ArO. radicals, we derived individual rate constants for LOO. reactions with the phenols (greater than 10(7) dm3 mol-1 s-1), with the aroxyl radicals to form covalent adducts (greater than 10(8) dm3 mol-1 s-1), as well as for their bimilecular decay (3.0 X 10(8) dm3 mol-1 s-1). These results demonstrate the high reactivity of both fatty acid peroxyl radicals and the flavone antioxidants in aqueous solution.

Radical scavenging by flavonoid antioxidants

Aroxyl radicals of fifteen structurally distinct flavonoids were generated by attack of azide radicals (N3.) on the parent compounds dissolved in aqueous solution at pH 11.5. Generation rate constants were all found to be very high (2.4-8.8 x 10(9) dm3mol-1 s-1), whereas the decay rates differed considerably, ranging from 10(5) to 10(8) dm3mol-1 s-1. In most cases the spectral characteristics of the transient aroxyl radicals relate to structural features of the parent compounds and according to spectral similarities they can be classed in three distinct groups (with only two exceptions). Although the data do not conclusively prove that the biological function of flavonoids might be the scavenging of radicals, the very high rate constants of formation and the relative stability of some of the aroxyl radicals, are in support of such a hypothesis.

The reaction of sulfite radical anion with nucleic acid components

The sulfite radical anion (SO3.-) is the first intermediate in the autoxidation of sulfite to sulfate. Using competition kinetics, its reactivities with the nucleic acid bases and the corresponding nucleosides were investigated. The second order rate constants were found to be rather low, k less than or equal to 1 x 10(6) dm3mol-1s-1 at pH 7. As a competitor, the carotenoid crocin was used, which was found to be bleached very efficiently by SO3.- (k = 1.0 x 10(9) dm3mol-1 s-1).

The kinetics of the reaction of ferritin with superoxide

Using pulse radiolysis and competition kinetics with cytochrome c, the reaction of superoxide with horse spleen ferritin was investigated. The second-order rate constant is estimated to be 2 +/- 1 x 10(6) dm3 mol-1 s-1.

Pulmonary tuberculosis among contacts of patients with tuberculosis in an urban Indian population

The study was conducted among 1810 contacts of 50 index "cases"/"suspects" of pulmonary tuberculosis including 312 household and 1498 neighbourhood contacts in the Jhansi city of Uttar Pradesh. The overall prevalence of radiologically active and bacteriologically confirmed tuberculosis was 2.9% and 1.1%. The prevalence rates of radiologically active and bacteriologically confirmed disease, although comparatively high in both the contact groups, were significantly higher in household (5.4% and 2.6%) than in neighbourhood contacts (2.3% and 0.8%). Significant differences in distribution of secondary cases among clusters were observed. Although higher prevalence rates were found in contacts of sputum positive source than in contacts of sputum negative source in both the contact groups, the statistical difference was observed to be insignificant. Case yield among contact symptomatics was 80.0% (30.8% cases and 49.2% suspects).

The value of the small bowel enema to the general surgeon

Lesions of the small bowel are notoriously difficult to diagnose, many only coming to light at laparotomy. At this hospital the small bowel enema has been used for radiology of the small bowel for many years. The procedure is uncomfortable for the patient, as intubation of the proximal small bowel is essential, and for the radiologist it can be very time-consuming. A review of patients referred by the general surgeons over the past 5 years has demonstrated the value of the technique. It has proved to be accurate in over 90 per cent of cases with only 2 per cent false negative and 1 per cent false positive results. The most common diagnosis has been Crohn's disease which can be very accurately assessed. Other lesions diagnosed include lymphoma, involvement by metastases, benign stricture and adhesions. A normal results has prevented an unnecessary laparotomy in several patients. It is concluded that this technique is the most satisfactory method for radiology of the small bowel and it should be much more widely available.

Epidemiology of human rotavirus diarrhoea: a review

Human rotavirus has been held to be responsible in as many as 60-80% of acute diarrheas between 6-24 months of age in India, especially during winter season. Antibodies against human rotavirus have been demonstrated in more than 90% of children aged 5 years indicating a previous infection. Vomiting, diarrhea, mild temperature with mild to severe dehydration have been observed to be the common features of human rotavirus diarrhea. The management consists of rehydration therapy by fluids and electrolytes while antibiotics are of no use. Development of an oral, live, attenuated polyvalent vaccine for producing enteric and humoral immunity against human rotavirus diarrhea will be ideal to prevent morbidity and mortality in developed as well as developing countries.

Radical intermediates involved in the bleaching of the carotenoid crocin. Hydroxyl radicals, superoxide anions and hydrated electrons

The participation of the primary radicals in the bleaching of aqueous solutions of the carotenoid crocin by ionizing radiation was investigated, employing both X-radiolysis and pulse radiolysis. The pulse-radiolytic data demonstrated a very rapid diffusion-controlled attack by both hydroxyl radicals (.OH) and hydrated electrons (eaq-), while superoxide anions (O2-) did not react at all. The site of the initial reaction of these radicals was not limited to the polyene chromophore. Slower secondary reactions involving crocin alkyl or peroxy radicals contribute mainly to the overall bleaching, in particular during steady-state irradiation.

Formation of ethylene from methionine. Reactivity of radiolytically produced oxygen radicals and effect of substrate activation

Ethylene was determined by gas chromatography after reaction of radiolytically produced OH and O2- radicals with methionine, methionine + pyridoxal phosphate and S-adenosyl-methionine (SAM). Both oxygen radicals, alone or in combination, liberate ethylene from methionine and methionine/pyridoxal phosphate. From SAM ethylene was primarily produced by the combined attack of OH nad H2O2 or O2-.

On the nature of biochemically generated hydroxyl radicals. Studies using the bleaching of p-nitrosodimethylaniline as a direct assay method

An efficient scavenger for radiolytically generated hydroxyl (OH) radicals, p-nitrosodimethylaniline, was used to try to substantiate the presence of this oxygen radical species in several biochemical systems. Most of these systems which were investigated had previously been assumed to generate OH radicals, e.g. the autoxidation of 6-hydroxydopamine, the hydroxylating system NADH/phenazine methosulfate, and the oxidation of xanthine or acetaldehyde by xanthine oxidase. We did not observe inhibition of the bleaching of p-nitrosodimethylaniline in oxygenated solutions by other scavengers of OH radicals nor, in the case of xanthine/xanthine oxidase, by catalase and superoxide dismutase. We therefore conclude that, under biochemical conditions as opposed to radiolysis or photolysis, no freely diffusable OH radicals are formed. Rather, a strongly oxidizing OH-analogous complex is considered to represent the p-nitrosodimethylaniline-detectable species formed under these conditions.

Pulse-radiolytic investigations of catechols and catecholamines. II. Reactions of Tiron with oxygen radical species

Transient spectra and kinetic data of Tiron (1,2-dihydroxybenzene-3,5-disulphonic acid) are reported, obtained after pulse-radiolytic oxidation by hydroxyl radicals (.OH), superoxide anions (O-2) or a combination of both oxygen radicals. The rate constant with .OH radicals was determined at 1.0.10(9) M-1.s-1. Contrary to a previous report (Greenstock, C.L. and Miller, R.W. (1975) Biochim. Biophys. Acta 396, 11--16), the rate constant with O-2 of 1.0.10(7) M-1.s-1 is lower by one order of magnitude; also the semiquinone absorbs at 300 nm rather than at 400 nm. The ratio of the rate constants with .OH and O-2 of 100 again demonstrates that any oxidation reaction by the latter radical is unspecific due to the more efficient reaction of .OH radicals, leading to the same products with catechol compounds.