The role of lipoteichoic acids on the adherence of Streptococcus equi to epithelial cells     

Satish K. Srivastava  Donald A. Barnum 《Veterinary microbiology》1983,8(5):485-492

The effect of the presence of lipoteichoic acids (LTA) on a strain of Streptococcus equi was investigated. The LTA were extracted in a crude form from the S. equi strain and were found to sensitize sheep red blood cells so that they agglutinated with antibodies specific to purified LTA of group A streptococci. The crude LTA preparation was also able to inhibit the specific haemagglutination reaction involving group A streptococcal LTA and LTA antibodies. Neither the purified LTA from group A streptococci nor the anti-LTA serum interfered with the adherence of S. equi to equine epithelial cells.  相似文献   

Pharmacokinetics and dosage regimen of cefotaxime in cross-bred calves following single intramuscular administration     

S. K. Sharma  A. K. Srivastava 《Veterinary research communications》1994,18(4):313-318

The pharmacokinetics, penetration into erythrocytes and plasma protein binding of cefotaxime were investigated in cross-bred calves. Following a single intramuscular dose of cefotaxime (10 mg/kg), the absorption half-life and elimination half-life were 0.13±0.03 h and 2.97±0.72 h, respectively. The apparent volume of distribution and total body clearance were 3.28±0.72 L/kg and 0.78±0.08 L/kg per h, respectively. The extent of penetration into erythrocytes was 24–40% of the total blood concentration. Cefotaxime was bound to plasma proteins of calves to the extent of 25.5–33.6%. A satisfactory intramuscular dosage regimen for cefotaxime in calves would be 11 mg/kg followed by 10 mg/kg at 7 h intervals.Abbreviations ATCC American type cell culture - MIC minimum inhibitory concentration - PCV packed cell volume  相似文献   

Cell Membrane Stability in Relation to Drought Tolerance in Wheat Genotypes     

M. Singh    J. P. Srivastava  A. Kumar 《Journal of Agronomy and Crop Science》1992,168(3):186-190

Genotyptc differences in wheat were observed in cell membrane with respect to injury caused by osmotic shock created with 40 per cent polyethylene glycol-6000. In general, genotypes with high cell membrane injury also registered much reduction in leaf water potential and osmotic potential. Cell membrane injury measured at 25 days after germination was found to be related with genotypic performance under drought conditions in field. Cell membrane stability measurements of normal plants, even at a very early stage of growth, is reported as criteria for selecting drought tolerant wheat genotypes.  相似文献   

Prevalent Serotypes of Pasteurella multocida Isolated from Different Animal and Avian Species in India     

Kumar AA  Shivachandra SB  Biswas A  Singh VP  Singh VP  Srivastava SK 《Veterinary research communications》2004,28(8):657-667

Identification and estimation of the prevalence of Pasteurella multocida organisms in different animal and avian species in India during November 2000 to July 2003 was carried out. Out of 418 samples collected from different outbreaks suspected to be caused by P. multocida, a total of 206 bacterial cultures were identified as P. multocida on the basis of cultural, morphological and biochemical characteristics. All the 206 cultures were isolated from different domestic animal species (cattle, buffalo, sheep, goat, pig and rabbit), avian species (chicken, duck, quail, turkey, goose) and wild animals such as leopard and deer. Serotyping of P. multocida cultures revealed the presence of various serotypes (A:1, A:3, A:1,3, A:4, B:2, D:1 and -:1) among the livestock population. P. multocida polymerase chain reaction (PCR) assay applied on different forms of bacterial cultures (bacterial culture lysate, direct bacterial colony and mixed bacterial culture lysate) yielded an amplified product of approximately 460 bp specific for P. multocida. The results of PCR assay correlated well with conventional methods of identification. The present investigation revealed the presence of varied serotypes among livestock and PCR assay was found to be useful for rapid, sensitive and specific diagnosis of pasteurellosis in animals and avian species.  相似文献   

Identification of avian strains of Pasteurella multocida in India by conventional and PCR assays   总被引：1，自引：0，他引：1  

Shivachandra SB  Kumar AA  Gautam R  Singh VP  Saxena MK  Srivastava SK 《Veterinary journal (London, England : 1997)》2006,172(3):561-564

The prevalence of capsular and somatic serotypes were studied among 123 Pasteurella multocida strains isolated from chickens (n = 94), ducks (22), quails (4), turkeys (2) and geese (1) from different geographical regions of India. All strains exhibited similar cultural and morphological characteristics. Ninety-two of the isolates belonged to serotype A:1, the most prevalent serotype, with serotypes A:3, A:1,3, D:3 and F:3 having two isolates each. Only one isolate was positive for serotypes A:4 and D:1. Twenty isolates were untyped. A multiplex capsular PCR assay generated amplicons of sizes 460, 1044, 657 and 854 bp in 106 isolates identified as capsular serotype-A, 15 in serotype D and two in serotype F. Capsular types B and E were not detected in any of the avian isolates studied. The present findings suggest that a multiplex capsular PCR assay may be suitable for the rapid initial identification serotypes P. multocida during epidemiological studies of fowl cholera.  相似文献   

Predators accelerate nutrient cycling in a bromeliad ecosystem     

Ngai JT  Srivastava DS 《Science (New York, N.Y.)》2006,314(5801):963

Conventional ecological theory predicts that predators affect nutrient cycling by decreasing the abundance or activity of prey. By using a predator-detritivore-detritus food chain in bromeliads, we show that predators can increase nutrient cycling by a previously undescribed, but broadly applicable, mechanism: reducing nutrient export by prey emigration. Contrary to expectations, predation on detritivores increases detrital nitrogen uptake by bromeliads. Predation reduces detritivore emergence and hence export of nitrogen from the system. Detritivores therefore benefit their host plant, but only when predators are present. More generally, our results show that predator loss or extinction can dramatically and unexpectedly affect ecosystem functioning.  相似文献   

Bioactivity guided isolation of antipsychotic constituents from the leaves of Rauwolfia tetraphylla L     

Gupta S  Khanna VK  Maurya A  Bawankule DU  Shukla RK  Pal A  Srivastava SK 《Fitoterapia》2012,83(6):1092-1099

This study was undertaken to ascertain the antipsychotic properties of Rauwolfia tetraphylla L. leaves and to isolate and characterize the antipsychotic constituents. Among the MeOH extract and some alkaloidal fractions at different pHs, the alkaloidal CHCl(3) fraction at pH-9 (2C) showed the highest antipsychotic activity against dopaminergic (DA-D(2)) and serotonergic (5-HT(2A)) receptors in-vitro and amphetamine induced hyperactive mouse model in-vivo. The activity guided isolation of CHCl(3) fraction (2C) afforded six indole alkaloids: 10-methoxytetrahydroalstonine (1), isoreserpiline (2), an isomeric mixture of 11-demethoxyreserpiline (3) and 10-demethoxyreserpiline (4), α-yohimbine (5) and reserpiline (6). Given orally, alkaloids 3-6 showed significant antipsychotic activity in a dose dependent manner. None of the extract, alkaloidal fractions or alkaloids showed any extra pyramidal symptoms at the tested doses. It was also observed that MeOH extract was behaving similar to other clinically used novel atypical antipsychotics in having 5-HT(2A) occupancy greater than the DA-D(2) receptor at the tested doses. Further toxicity and safety evaluation studies of MeOH extracts of R. tetraphylla leaves at different doses (10, 100, 300 and 2000 mg/kg) on female Swiss albino mice showed that MeOH extract is non toxic. The isolated alkaloids, 3-6 could serve as a promising lead structure for drug development of treating psychotic conditions in human.  相似文献   

Landscaping and performance of some aesthetic plant species in hot, arid conditions of India     

Rajesh Kumar Gupta  Pradeep Chaudhry  Rameshwar Lal Srivastava 《林业研究》2012,23(2):305-309

Establishment of ornamental and aesthetic plants in hot, arid conditions of India is difficult due to the prevailing climatic, edaphic and biotic factors. Effect of turfgrass on the growth of ornamental plants in hot arid conditions has not been studied so far anywhere in the world. A study was conducted on the campus of Arid Forest Research Institute, Jodhpur, India to assess the performance of a few ornamental plant species in combination with turfgrass and without turfgrass with respect to different soil tilling intervals. Growth of plants was better with turfgrass than without turfgrass. We suggest adopting a soil tilling interval of 30 days to achieve optimum growth of ornamental plant species in terms of height and crown diameter. Our results can help reduce labor costs and achieving better landscapes in fewer days in hot urban conditions of Indian sub continent.  相似文献   

Impact of molybdenum on the copper status of red deer (Cervus elaphus)     

ND Grace  PR Wilson  AK Quinn 《New Zealand veterinary journal》2013,61(2):137-141

AIM: To determine the effect of increasing molybdenum (Mo) intakes on serum and liver copper (Cu) concentrations and growth rates of grazing red deer (Cervus elaphus).

METHODS: Molybdenum- and Cu-amended fertilisers were applied to six 1.1-ha paddocks in a 3 × 2 design. Three levels of Mo were applied on two paddocks at each level in mid April (designated Day 1); levels were: none (control), 0.5 (medium) and 1.0 (high) kg Mo/ha as sodium molybdate. In late May (Day 39), two levels of Cu (none and 3.0 kg Cu/ha, as copper sulphate) were applied to each of the three levels of Mo-treated paddocks. Pasture Mo, Cu and sulphur (S) concentrations were measured at about fortnightly intervals. In late June (Day 74), ten 6-month-old red deer hinds were placed on the six experimental pastures, and serum and liver Cu concentrations were monitored at about monthly intervals for 102 days. The hinds were weighed on four occasions during the trial.

RESULTS: Mean pasture Mo concentrations on Day 56 were 2, 4.6 and 11.3 mg/kg dry matter (DM) for the untreated control, medium and high Mo-treated pastures, respectively. Pasture Cu concentration was 95 mg/kg DM on Day 59, 53 mg/kg DM on Day 90, and 9 mg/kg DM by Day 153. Mean S concentration in pasture was 3.3 (range 3.03–3.45) g/kg DM. Copper application to pasture had no significant effect on serum and liver Cu concentrations in deer so data were pooled within Mo treatment. Mean initial (Day 74) serum Cu concentration was 9.2 µmol/L. In the deer grazing the control Mo pasture, this increased to 10.3 µmol/L on Day 112, before decreasing to 6.4 µmol/L on Day 176. In deer grazing the medium and high Mo-treated pastures, mean serum Cu concentrations were 3.8 and 3.9 µmol/L, respectively, on Day 112, and 2.5 and 3.3 µmol/L, respectively, on Day 176. Mean initial (Day 74) liver Cu concentration was 131 µmol/kg fresh tissue. In the deer grazing the control Mo pasture, this declined to 120 and 52 µmol/kg on Days 112 and Day 176, respectively. In deer grazing the medium and high Motreated pastures, liver Cu concentrations decreased to 55 and 52 µmol/kg fresh tissue, respectively, on Day 112, and 21 and 20 µmol/kg fresh tissue, respectively, on Day 176. Mean serum and liver Cu concentrations were not significantly different between deer grazing the medium and high Mo-treated pastures, and were lower (serum p=0.003, liver p<0.001) in those groups than in deer grazing the untreated control pastures. No clinical signs of Cu deficiency associated with lameness were observed. Deer grazing pastures that had Mo concentrations >10 mg/kg DM had lower (p=0.002) growth rates (100 vs 130 g/day) than those on pastures containing <2.4 mg Mo/kg DM.

CONCLUSION: Increasing pasture Mo concentrations from 2 mg/kg DM to ≥4.6 mg/kg DM significantly reduced serum and liver Cu concentrations in grazing deer. Reduced growth rate was observed at pasture Mo concentrations >10 mg/kg DM.  相似文献   

Design of Optimum Response Surface Experiments for Electro-Coagulation of Distillery Spent Wash     

R. Krishna Prasad  R. Ram Kumar  S. N. Srivastava 《Water, air, and soil pollution》2008,191(1-4):5-13

Electro-coagulation (EC) of a distillery spent wash has been optimized by Box–Behnken design of surface response analysis in terms of color removal. The design was employed to derive a statistical model for the effect of parameters studied on removal of color using iron anodes. The current density (31 mA/cm²), dilution (17.5%) and time of electrolysis (4 hours) had been found to be the optimum conditions for maximum 95% color removal. The actual color removal at optimized conditions was found to be 93.5% which confirms close to the predicted response using response surface methodology.  相似文献