Modulation of convulsive threshold of pentylene tetrazole by zinc

In the present study which was aimed to see the effect of zinc on pentylenetetrazole induced convulsive threshold in rats we found that zinc sulfate 100 μg intracerebroventricularly) and pentylenetetrazole (50 mg/kg intraperitoneally) produced dose related seizure activity; however, pretreatment with zinc decreased the threshold, increased the severity, incidence of multiple seizures and total duration of pentylenetetrazole induced seizures. Diazepam (5 mg/kg intraperitoneally) pretreatment increased the threshold and lowered the incidence of convulsions in zinc induced seizures which further confirms that the convulsive effect of zinc is through inhibition of gamma aimino butyric acid.

A new spray reagent for the detection of synthetic pyrethroids containing a nitrile group on thin-layer plates

This paper describes a new spray reagent for selective detection of synthetic pyrethroids containing alpha-cyano group i.e. lambda-cyhalothrin, deltamethrin, cyfluthrin and fluvalinate by thin layer chromatography. These synthetic pyrethroids on alkaline hydrolysis, yield a cynohydrin derivative which degrades to give HCN and a corresponding aldehyde. This liberated HCN reduces 2-(4-iodophenyl)-3-(4-nitrophenyl)-5-phenyl tetrazolium chloride (INT) to formazan, a pink product in the presence of phenazonium methosulfate (PMS). The pink colour formed remain stable for more than 24 h. Other group of insecticides like organophosphorus, organochlorine and carbamate do not interfere in the determination. Pyrethroid insecticides not containing hydrolysable nitrile group also do not interfere. The limit of detection is from 0.5 to 1 mug.

Substitute of Animals in Drug Research: An Approach Towards Fulfillment of 4R's

The preclinical studies for drug screening involve the use of animals which is very time consuming and expensive and at times leads to suffering of the used organism. Animal right activists around the world are increasingly opposing the use of animals. This has forced the researchers to find ways to not only decrease the time involved in drug screening procedures but also decrease the number of animals used and also increase the humane care of animals. To fulfill this goal a number of new in vitro techniques have been devised which are called 'Alternatives' or 'Substitutes' for use of animals in research involving drugs. These 'Alternatives' are defined as the adjuncts which help to decrease the use as well as the number of animals in biomedical research. Russell and Burch have defined these alternatives by three R's - Reduction, Refinement and Replacement. These alternative strategies include physico-chemical methods and techniques utilizing tissue culture, microbiological system, stem cells, DNA chips, micro fluidics, computer analysis models, epidemiological surveys and plant-tissue based materials. The advantages of these alternatives include the decrease in the number of animals used, ability to obtain the results quickly, reduction in the costs and flexibility to control the variables of the experiment. However these techniques are not glittering gold and have their own shortcomings. The disadvantages include the lack of an appropriate alternative to study the whole animal's metabolic response, inability to study transplant models and idiosyncratic responses and inability to study the body's handling of drugs and its subsequent metabolites. None-the-less these aalternative methods to certain extent help to reduce the number of animals required for research. But such alternatives cannot eliminate the need for animals in research completely. Even though no animal model is a complete set of replica for a process within a human body, the intact animal does provide a better model of the complex interaction of the physiological processes.

Mouthparts and stylet penetration of the lac insect Kerria lacca (Kerr) (Hemiptera:Tachardiidae)

Hitherto less known aspects on mouthpart morphology and penetration mechanism of the lac insect Kerria lacca have been explored. Unique details of the mouthparts, i.e. morphology of labium and stylets and salivary sheath have been brought out. The gross morphology of the mouthparts though resembled other plant sucking homopterans; a two-segmented labium with symmetrically distributed six pairs of contact-chemoreceptors on its surface was distinct; the mandibular stylets had serrations on its extreme apical region, while the maxillary stylets had their external surface smooth with parallel longitudinal grooves on their inner surface. Formation of flanges, salivary sheath and penetration pathway observed along with probing and penetration of the stylets intracellularly up to the phloem cells, as illustrated herein, are the addition to the existing knowledge on the structural details of the mouthparts and the feeding behavior thereupon.

Assessment of flubendiamide residues in pigeon pea in different agro-climatic zones of India

Supervised field trials were conducted at the research farms of four agricultural universities located at different agro-climatic zones of India to find out the harvest time residues of flubendiamide and its des-iodo metabolite on pigeon pea (Cajanus cajan) during the year 2006-2007. Two spray applications of flubendiamide 20 WDG at 50 g (T(1)) and 100 g (T(2)) a.i./ha were given to the crop at 15-days interval. The foliage samples at different time intervals were drawn at only one location, however, the harvest time samples of pigeon pea grain, shell, and straw were drawn at all the four locations. The residues were estimated by HPLC coupled with UV-VIS variable detector. No residues of flubendiamide and its des-iodo metabolite were found at harvest of the crop at or above the LOQ level of 0.05 μg/g. On the basis of the data generated, a pre-harvest interval (PHI) of 28 days has been recommended and the flubendiamide 20 WDG has been registered for use on pigeon pea by Central Insecticide Board and Registration Committee, Ministry of Agriculture, Government of India and the MRL has been fixed by Ministry of Health and Family Welfare, Government of India under Prevention of Food and Adulteration as 0.05 μg/g on pigeon pea grains.

Persistence and dissipation kinetics of deltamethrin on chili in different agro-climatic zones of India

Multi-location supervised field trials were conducted at four different agro climatic locations in India to evaluate the dissipation pattern of deltamethrin on chili. Deltamethrin 10 EC was applied on chili @17.5 and 35 g a.i. ha(-1), samples of green chili were drawn at different time intervals and that of red chili and soil at harvest time and quantified by gas liquid chromatography equipped with electron capture detector. The identity of residues were confirmed by Gas Chromatograph-Mass Spectrophotometer in selective ion monitoring mode in mass range 181, 253 m/z. Limit of quantification of the method was found to be 0.01 mg kg(-1). Half-life of deltamethrin at application rate of 17.5 g a.i. ha(-1) varied from 0.36 to 1.99 days and at double the application rate was found to range from 0.38 to 2.06 days. Residues of deltamethrin were found below its determination limit of 0.01 mg kg(-1) in red chili and soil. On the basis of the data generated, Deltamethrin 10 EC has been registered for use on chili in India and its Maximum Residue Limit has been fixed as 0.05 μg/g.

Prostate specific antigen in cord blood

Recent studies have demonstrated the presence of prostate specific antigen (PSA) in cord blood of male as well as female babies. The placental progesterone and estradiol up-regulate the synthesis and secretion of PSA in Placenta. This PSA is presumed to play a role in intrauterine growth of fetus by virtue of its proteolytic action on several substrates including insulin-like-growth-factor-binding-protein-3, insulin chains and Interleukin-2. This study was planned with the objective of correlating the levels of PSA in cord blood to gestation at delivery, the type of delivery and gender of the fetus. Fifty-seven cord blood samples were collected from the umbilical cord during delivery or mid-trimester abortion and analyzed for PSA using 'Active PSA DSL-9700 ultra sensitive' kit employing two-site immuno-radiometric assay principle and having a detection limit of 0.001 ng/ml. Mean PSA levels in cord blood were found to be 0.112 ± 0.027 ng/ml. The concentration of PSA in cord blood was found to be higher in case of higher gestational age, male baby and operative delivery. 50 % of cord bloods for female babies had PSA below detection limit (range <0.001-0.460 ng/ml), while all the male samples had detectable PSA (range 0.11-0.973 ng/ml). Higher Progesterone levels found in prenatal maternal blood in case of male babies may be responsible for the higher cord blood PSA. Mean cord blood PSA was 0.150 ± 0.150 ng/ml in forceps delivery and 0.078 ± 0.012 ng/ml in normal vaginal delivery. Forceps delivery causes much more stress and strain as compared to a normal vaginal delivery, resulting in increased levels of adrenal glucocorticoids, and therefore, higher cord blood PSA.

Persistent high prevalence of cardiovascular risk factors in the urban middle class in India: Jaipur Heart Watch-5

BACKGROUND AND OBJECTIVE

Urban subjects have high burden of cardiovascular risk factors, therefore, to evaluate risk factors in middle socioeconomic subjects and to study secular trends we performed an epidemiological study.

METHODS

The study was performed at urban middle class locations defined according to municipal records in years 2009-10. Stratified random sampling using house-to-house survey was performed. Details of medical history, anthropometry and clinical examination were recorded and biochemical tests performed for estimation of fasting glucose and lipids. Current definitions were used for risk factor classification. Descriptive statistics are provided. Trends were calculated using ANOVA or Mantel Haenszel chi-square. Univariate and multivariate logistic regression was performed to assess risk factor determinants. To determine secular trends we compared risk factors with previous cross-sectional studies performed in same locations in years 2002-3 and 2004-5 in subjects 20-59 years age.

RESULTS

We evaluated 739 subjects (men 451, women 288, response 67%). Age-adjusted prevalence (%) of risk factors in men and women respectively was smoking 95 (21.1) and 12 (4.2), low physical activity 316 (69.6) and 147 (52.3), high fat intake > or = 20 gm/day 278 (73.4) and 171 (68.7), low fruits and vegetables intake < 3 helpings/day 249 (70.3) and 165 (76.4), overweight/obesity 205 (46.2) and 142 (50.7), high waist size 58 (12.9) and 76 (26.6), high waist:hip 143 (31.9) and 154 (53.9), hypertension 177 (39.5) and 71 (24.6), high total cholesterol > or = 200 mg/ dl 148 (33.0) and 93 (32.7), low HDL cholesterol < 40/50 mg/dl 113 (25.1) and 157 (55.3), diabetes 62 (15.5) and 25 (10.8) and metabolic syndrome 109 (25.1) and 61 (22.0). Age-associated increase was observed in body mass index, waist size, waist ratio:hip, systolic blood pressure and fasting and total cholesterol, non-HDL cholesterol and triglycerides in women (Ptrend < 0.01). Age related increase was also observed in prevalence of obesity, truncal obesity, hypertension, diabetes and metabolic syndrome (Ptrend < 0.01). On univariate analysis significant determinants of risk factors were low educational and socioeconomic status for smoking, high fat diet for obesity and hypertension, low fruits and vegetables intake for metabolic syndrome, and low physical activity or obesity but on age-and sex-adjusted multivariate analysis only association was high fat diet with obesity and hypertension (logistic regression analysis p < 0.05). Compared to studies performed at similar locations in years 2002-03 and 2005-06 there was increasing trend in prevalence of high non-HDL cholesterol and hypertriglyceridemia (Ptrend < 0.05) while other risk factors did not change significantly.

CONCLUSIONS

There is a high prevalence of multiple cardiovascular risk factors in Indian middle class individuals. Secular trends demonstrate a persistent high prevalence and increasing non-HDL cholesterol and triglycerides over 8-year period.

Evaluation of anticonvulsant and nootropic effect of ondansetron in mice

The role of serotonin receptors have been implicated in various types of experimentally induced seizures. Ondansetron is a highly selective 5-hydroxytryptamine 3 (5-HT3) receptor antagonist used as antiemetic agent for chemotherapy-, and radiotherapy-induced nausea and vomiting. The present study was carried out to examine the effect of ondansetron on electroshock, pentylenetetrazole (PTZ)-induced seizures and cognitive functions in mice. Ondansetron was administered intraperitoneally (i.p.) at doses of 0.5, 1.0 and 2.0 mg/kg (single dose) to observe its effect on the increasing current electroshock seizure (ICES) test and PTZ-induced seizure test. In addition, a chronic study (21 days) was also performed to assess the effects of ondansetron on electroshock-induced convulsions and cognitive functions. The effect on cognition was assessed by elevated plus maze and passive avoidance paradigms. Phenytoin (25 mg/kg, i.p.) was used as a standard anticonvulsant drug and piracetam (200 mg/kg) was administered as a standard nootropic drug. The results were compared with an acute study, wherein it was found that the administration of ondansetron (1.0 and 2.0 mg/kg) significantly raised the seizure-threshold current as compared to control group in the ICES test. Similar results were observed after chronic administration of ondansetron. In PTZ test, ondansetron in all the three tested doses failed to show protective effect against PTZ-induced seizure test. Administration of ondansetron for 21 days significantly decreased the transfer latency (TL) and prolonged the step-down latency (SDL). The results of present study suggest the anticonvulsant and memory-enhancing effect of ondansetron in mice.

Protective role of curcumin on colchicine-induced cognitive dysfunction and oxidative stress in rats

Dementia is a syndrome of progressive nature, affects wide range of cognitive abilities like memory, language, calculation and so on, neuropsychiatric and social deficits to impair the routine social functions. The present study was designed to assess the effect of curcumin against colchicine-induced cognitive dysfunction and oxidative stress in rats and compare it with rivastigmine. Colchicine (15 µg/5µl) was administered to male Wistar rats intracerebroventricularly (i.c.v.) by stereotaxic apparatus to induce cognitive dysfunction. Administration of colchicine caused poor retention of memory in elevated plus maze, passive avoidance apparatus and Morris water maze paradigms. Chronic treatment with curcumin (100, 200 and 400 mg/kg, p.o.) twice daily and rivastigmine (2.5 mg/kg, p.o.) daily for a period of 28 days beginning 7 days prior to colchicine injection significantly improved colchicine-induced cognitive impairment. Biochemical assessment revealed that i.c.v. colchicine injection significantly increased lipid peroxidation, depleted reduced glutathione levels and decreased acetyl cholinesterase (AChE) activity in rat brains. Chronic administration of curcumin significantly reduced the elevated lipid peroxidation, restored the reduced glutathione levels and AChE activity; however, rivastigmine failed to prevent oxidative stress. The results of the current study indicate that curcumin (100, 200 and 400 mg/kg, p.o.) twice daily has a protective role against colchicine-induced cognitive impairment and associated oxidative stress.

Antagonism of stimulation-produced analgesia by naloxone and N-methyl-D-aspartate: role of opioid and N-methyl-D-aspartate receptors

The present study aims to investigate the influence of electrical stimulation of periaqueductal gray (PAG) following peripheral nerve injury and its modulation by naloxone and N-methyl-D-aspartate (NMDA). Chronic neuropathic pain was induced by chronic constriction injury of the sciatic nerve, and subsequently a cannula was implanted in the PAG area for the purpose of electrical stimulation and intra-PAG drug administration. Intra-PAG administration of morphine, ketamine, and their combination were found to elicit antinociceptive response on hot-plate test. Electrical stimulation of PAG was also observed to demonstrate decreased pain response on hot-plate test, and this effect was reversed by the administration of naloxone, NMDA, and their combination, when injected into the PAG area. These findings suggest that apart from the opioid receptors, probably NMDA receptors also have a role to play in stimulation-produced analgesia.

Effect of flaring of natural gas in oil fields of Assam on rice cultivation

Assam (India) is endowed with natural resources like oil, coal and natural gas. The crude oil, one of the most precious natural resources, is found in the districts of upper Assam. During the process of extraction of crude oil, low-pressure natural gas is burnt in the air. Most of the oil wells in upper Assam are located near rice fields and therefore, rice crop grown near the oil wells is exposed to light uninterruptedly causing grain sterility resulting significant loss in grain yield. To identify promising varieties for these areas, we studied the effect of flare on rice varieties with different photoperiod sensitivity. The high light intensity and increased light hours were the factors responsible for substantial loss in grain yield near the flare resulting from delay in flower initiation, reduction of panicle length, having less number of grains per panicle and more grain sterility. To prevent significant loss in yield, photoperiod-sensitive traditional and improved rice varieties should not be grown up to the distance of 80 and 100 m, respectively from the boundary wall of the flare pit. Modern weakly-photoperiod sensitive varieties like Ranjti and Mahsuri can be grown 40 m away from the wall while modern photoperiod insensitive variety like Jaya, can be cultivated 20 m away from the wall without significant loss in yield.

Persistence and safety risk assessment of propineb in Indian tea

A supervised field trial was conducted on tea with propineb at 1,750 and 3,500 g a.i./ha at two locations (Assam and Darjeeling), applied thrice at an interval of 10 days during the year 2006-2007. Propineb residue was measured spectrophotometrically at 435 nm in terms of CS2. The initial deposit of propineb in green tea leaves were found to be in the range of 16.26-35.96 mg/kg and the residue persisted up to 10 days irrespective of doses and locations with half-life value ranging from 2.24 to 2.43 days and preharvest interval of 17.17-21.37 days. Made tea residues ranged from 9.27 to 20.86 mg kg(-1) on 7 days and no residues could be detected on 14 days. Infusion study indicated that propineb did not infuse into tea liquor from made tea. The limit of determination was found to be 0.1 mg kg(-1) in terms of propineb for green tea leaves, made tea, and tea liquor. The tea applied with the recommended dose of propineb is safe for consumption as liquor.

Potassium channel openers exhibit cross-tolerance with morphine in two experimental models of pain

OBJECTIVE

The study was performed to assess the effect of potassium channel openers on morphine tolerance and vice-versa.

METHODS

Swiss albino mice of either gender weighing between 25-30 g were used for the study The study assesses the effect of potassium channel openers (cromakalim, diazoxide and minoxidil) on morphine tolerance and vice-versa, using formalin and tail-flick tests.

RESULTS

The antinociceptive effect of cromakalim and minoxidil was significantly reduced when administered to morphine-tolerant mice, in both the behavioural tests. However reduced analgesic effect of diazoxide was observed on morphine-tolerance in the formalin test but not in the tail-flick test. Tolerance was observed when morphine was administered to animals chronically treated with any of the potassium channel openers. The same effect was observed when morphine was injected into a group treated with a combination of morphine and any of the potassium channel openers.

CONCLUSIONS

This study, therefore, suggests that both morphine and potassium channel openers are cross-tolerant. However such interaction occurs at the level of potassium channels rather than at the level of receptors.

The mechanism of HIV-1 Tat-directed nucleic acid annealing supports its role in reverse transcription

The main function of the HIV-1 trans-activator of transcription (Tat protein) is to promote the transcription of the proviral DNA by the host RNA polymerase which leads to the synthesis of large quantities of the full length viral RNA. Tat is also thought to be involved in the reverse transcription (RTion) reaction by a still unknown mechanism. The recently reported nucleic acid annealing activity of Tat might explain, at least in part, its role in RTion. To further investigate this possibility, we carried out a fluorescence study on the mechanism by which the full length Tat protein (Tat(1-86)) and the basic peptide (44-61) direct the annealing of complementary viral DNA sequences representing the HIV-1 transactivation response element TAR, named dTAR and cTAR, essential for the early steps of RTion. Though both Tat(1-86) and the Tat(44-61) peptide were unable to melt the lower half of the cTAR stem, they strongly promoted cTAR/dTAR annealing through non-specific attraction between the peptide-bound oligonucleotides. Using cTAR and dTAR mutants, this Tat promoted-annealing was found to be nucleated through the thermally frayed 3'/5' termini, resulting in an intermediate with 12 intermolecular base pairs, which then converts into the final extended duplex. Moreover, we found that Tat(1-86) was as efficient as the nucleocapsid protein NCp7, a major nucleic acid chaperone of HIV-1, in promoting cTAR/dTAR annealing, and could act cooperatively with NCp7 during the annealing reaction. Taken together, our data are consistent with a role of Tat in the stimulation of the obligatory strand transfers during viral DNA synthesis by reverse transcriptase.

An efficient method for the production of marker-free transgenic plants of peanut (Arachis hypogaea L.)

Recombinant genes conferring resistance to antibiotics or herbicides are widely used as selectable markers in plant transformation for selecting the primary transgenic events. However, these become redundant once the transgenic plants have been developed and identified. Although, there is no evidence that the selectable marker genes are unsafe for consumers and the environment, it would be desirable if the marker genes can be eliminated from the final transgenic events. The availability of efficient transformation methods can enable the possibility of developing transgenic events that are devoid of the marker gene/s upfront. Taking advantage of the high and consistent transformation potential of peanut, we report a technique for developing its transgenics without the use of any selectable marker gene. Marker-free binary vectors harboring either the phytoene synthase gene from maize (Zmpsy1) or the chitinase gene from rice (Rchit) were constructed and used for Agrobacterium tumefaciens-mediated transformation of peanut. The putative transgenic events growing in vitro were initially identified by PCR and further confirmed for gene integration and expression by dot blots assays, Southern blots, and RT-PCR where they showed a transformation frequency of over 75%. This system is simple, efficient, rapid, and does not require the complex segregation steps and analysis for selection of the transgenic events. This approach for generation of marker-free transgenic plants minimizes the risk of introducing unwanted genetic changes, allows stacking of multiple genes and can be applicable to other plant species that have high shoot regeneration efficiencies.

Lorazepam versus diazepam-phenytoin combination in the treatment of convulsive status epilepticus in children: a randomized controlled trial

BACKGROUND

Convulsive status epilepticus demands urgent and appropriate management with anticonvulsants. Intravenous diazepam is an established drug in the management of convulsive status epilepticus in adults as well as in children. The efficacy of intravenous lorazepam has not been well established in children.

OBJECTIVE

To determine whether intravenous lorazepam is as efficacious as diazepam-phenytoin combination in the treatment of convulsive status epilepticus in children.

STUDY DESIGN

Randomized controlled trial.

METHODS

A total of 178 children were enrolled in the study; 90 in the lorazepam group and 88 in the diazepam-phenytoin combination group. Enrolled subjects were between 1 and 12 years with a clinical diagnosis of convulsive status epilepticus, presenting in pediatric emergency of a tertiary care hospital. They were randomized to receive either intravenous lorazepam (0.1 mg/kg) or intravenous diazepam (0.2 mg/kg)-phenytoin (18 mg/kg) combination at admission and were followed up for subsequent 18 h.

RESULTS

The overall success rate of therapy was 100% in both the groups. There was no statistically significant difference in the two groups (lorazepam versus diazepam-phenytoin combination) in the median time taken to stop the seizure [20s in both groups], the number of subjects requiring more than one dose of the study drug to stop the presenting seizure [lorazepam 6(6.7%) versus diazepam-phenytoin combination: 14 (15.9%); adjusted RR (95% CI)=0.377 (0.377, 1.046); P=0.061] and the number (%) of patients having respiratory depression [lorazepam 4(4.4%) versus diazepam-phenytoin combination 5 (5.6%)]. None of the patients in the two groups required additional anticonvulsant drug to stop the presenting seizure. No patient required mechanical ventilation and none of the patients in the two groups required cross-over to the alternative regimen.

CONCLUSION

Lorazepam is as efficacious and safe as diazepam-phenytoin combination. We recommend use of lorazepam as a single drug to replace the two drug combination of diazepam-phenytoin combination to control the initial seizure in pediatric convulsive status epilepticus.

Reversal of propoxur-induced impairment of step-down passive avoidance, transfer latency and oxidative stress by piracetam and ascorbic acid in rats

Propoxur, a carbamate pesticide has been shown to adversely affect memory and induce oxidative stress. The present study was designed to correlate the effect of propoxur, piracetam (a nootropic drug) and ascorbic acid (an antioxidant) on oxidative stress and cognitive function. Cognitive function was assessed using step-down latency (SDL) on a passive avoidance apparatus and transfer latency (TL) on elevated plus maze. Oxidative stress was assessed by examining brain malondialdehyde (MDA) and non-protein thiol (NP-SH) levels. A significant reduction in SDL and prolongation of TL was found for the propoxur-treated group at weeks 6 and 7 as compared with control (p<0.001). One week treatment by piracetam (400mg/kg/d, i.p.) or ascorbic acid (120mg/kg/d, i.p.) antagonized the effect of propoxur on SDL as well as TL. Both piracetam and ascorbic acid attenuated the propoxur-induced increase in brain MDA levels and decrease in brain NP-SH levels. Results of the present study show that ascorbic acid and piracetam have the potential to reverse cognitive dysfunction and oxidative stress induced by propoxur in the brain.

Mechanisms of strand break formation in DNA due to the direct effect of ionizing radiation: the dependency of free base release on the length of alternating CG oligodeoxynucleotides

The question of how NA base sequence influences the yield of DNA strand breaks produced by the direct effect of ionizing radiation was investigated in a series of oligodeoxynucleotides of the form (d(CG)(n))(2) and (d(GC)(n))(2). The yields of free base release from X-irradiated DNA films containing 2.5 waters/nucleotide were measured by HPLC as a function of oligomer length. For (d(CG)(n))(2), the ratio of the Gua yield to Cyt yield, R, was relatively constant at 2.4-2.5 for n = 2-4 and it decreased to 1.2 as n increased from 5 to 10. When Gua was moved to the 5' end, for example going from d(CG)(5) to d(GC)(5), R dropped from 1.9 +/- 0.1 to 1.1 +/- 0.1. These effects are poorly described if the chemistry at the oligomer ends is assumed to be independent of the remainder of the oligomer. A mathematical model incorporating charge transfer through the base stack was derived to explain these effects. In addition, EPR was used to measure the yield of trapped-deoxyribose radicals at 4 K following X-irradiation at 4 K. The yield of free base release was substantially greater, by 50-100 nmol/J, than the yield of trapped-deoxyribose radicals. Therefore, a large fraction of free base release stems from a nonradical intermediate. For this intermediate, a deoxyribose carbocation formed by two one-electron oxidations is proposed. This reaction pathway requires that the hole (electron loss site) transfers through the base stack and, upon encountering a deoxyribose hole, oxidizes that site to form a deoxyribose carbocation. This reaction mechanism provides a consistent way of explaining both the absence of trapped radical intermediates and the unusual dependence of free base release on oligomer length.

Differential antioxidative responses in transgenic peanut bear no relationship to their superior transpiration efficiency under drought stress

To counter the effects of environmental stresses, the plants must undergo detoxification that is crucial to avoid the accumulation of damaging free oxygen radicals (ROI). Here, we detail the oxidative damage, the antioxidant composition, and the osmoprotection achieved in transgenic plants of peanut overexpressing the AtDREB1A transgene, driven by a stress-inducible promoter (Atrd29A) when exposed to progressive water stress conditions. This study explored the biochemical mechanisms where (i) the antioxidants such as superoxide dismutase (SOD), ascorbate peroxidase (APOX), and glutathione reductase (GR) accumulated in the transgenic plants at comparably higher levels than their untransformed counterparts under dry soil conditions, (ii) a significant increase in the proline levels in the transgenic plants was observed in dry soils, and (iii) a dramatic increase in the lipid peroxidation in the untransformed controls in drier soils. Most of the biochemical parameters related to the antioxidative machinery in the tested peanut transgenics were triggered by the overexpression of AtDREB1A that appeared to differ from the untransformed controls. The antioxidants showed a negative correlation with the fraction of transpirable soil water (FTSW) thresholds, where the normalized transpiration rate (NTR) started decreasing in the tested plants. However, no significant relationship was observed between any of these biochemical indicators and the higher transpiration efficiency (TE) values found in the transgenic events. Our results show that changes in the antioxidative machinery in these transgenic peanut plants (overexpressing the AtDREB1A transcription factor) under water-limiting conditions played no causative role in improved TE.

Oral salbutamol for symptomatic relief in mild bronchiolitis a double blind randomized placebo controlled trial

OBJECTIVES

To determine the efficacy of oral salbutamol for providing symptomatic relief in mild bronchiolitis.

DESIGN

Randomized double-blind placebo controlled trial.

SETTING

Pediatric Outpatient Department of a tertiary care hospital.

SUBJECTS

140 infants (of 310 approached) with a clinical diagnosis of acute bronchiolitis with respiratory rate <or= 70 breath/min, heart rate <or= 200 beats/min, hemoglobin oxygen saturation (SpO2) >or= 95% in room air, no or mild accessory muscle use, and respiratory distress assessment instrument (RDAI) score <or=10. Children were followed up for 14 days.

INTERVENTION

Oral salbutamol (0.1 mg/kg/dose) (n=70) or placebo (n=70) three times a day for 7 days or till complete resolution of symptoms,whichever was earlier.

OUTCOME VARIABLES

Time for resolution of illness (ROI), duration of fever, cough,coryza, noisy breathing, time to achieve normal feeding and normal sleep, and frequency of hospitalization and adverse effects.

RESULTS

Median (SE, 95% CI) duration of resolution of overall illness was similar in the two groups [6 (0, 5 to 7) d in the salbutamol group vs. 5 (1, 4 to 6) days in placebo group; P=0.21]. There was no significant difference in mean duration of fever, cough, coryza, noisy breathing, time to achieve normal feeding and normal sleep; and frequency of hospitalization or adverse effects, between the two groups.However, tremors were observed in 5 infants in the salbutamol group.

CONCLUSION

Oral salbutamol is not superior to placebo in reducing the duration of symptoms in mild cases of acute bronchiolitis in children.