Studies on efficiency of guava (Psidium guajava) bark as bioadsorbent for removal of Hg (II) from aqueous solutions.

Biosorption of Hg (II) was investigated in this study by using guava bark powder (GBP). In the batch system, effects of various parameters like contact time, initial concentration, pH and temperature were investigated. Removal of Hg (II) was pH dependent and was found maximum at pH 9.0. Based on this study, the thermodynamic parameters like change in standard Gibb's free energy (DeltaG(0)), standard enthalpy (DeltaH(0)) and standard entropy (DeltaS(0)) were evaluated. The rate kinetic study was found to follow second-order. The applicability of Freundlich adsorption isotherm model was tested. The value of regression coefficient was greater than 0.99. This indicated that the isotherm model adequately described the experimental data of the biosorption of Hg (II). Maximum adsorption of 3.364 mgg(-1) was reached at 80 min. The results of the study showed that guava bark powder can be efficiently used as a low-cost alternative for the removal of divalent mercury from aqueous solutions.

Seasonal variations of heavy metal contamination in river Gomti of Lucknow city region.

The present study deals with the seasonal variations in the concentrations of heavy metals namely chromium, lead and mercury by using spectrophotometric methods. The water samples were collected at regular intervals from five selected sites of river Gomti in the pre-monsoon period (months of February-May) and the post monsoon period (months of October-January). The concentrations of chromium (VI) and mercury (II) were determined by using Genesys-10 UV-VIS Spectrophotometer while lead (II) concentrations were determined using Atomic Absorption Spectrophotometer, Perkin-Elmer 5000 model. The concentrations of all the three metals were found to be higher in the pre-monsoon period than in the post-monsoon period. The statistical analysis of the data was discussed in both the seasons in terms of mean, standard deviation and coefficient of variation.

Effect of Dictyocaulus filaria infection on the osmotic fragility of sheep erythrocytes.

The osmotic fragility of erythrocytes in lambs experimentally infected with Dictyocaulus filaria was studied weekly for 71 weeks. In acute infection, the erythrocytic fragility increased from the third week of infection onwards, reached its peak by the eleventh week and declined thereafter. However, in the chronic immune-carrier stage, this increase in the fragility did not return to normal until the end of the experiment. This enhanced fragility showed a positive correlation with the faecal larval count, worm burden and the extent of lung damage in lambs.

Studies on the prevalence and laboratory transmission of fascioliasis in animals in the Kashmir Valley.

In Kashmir, 85.1% of cattle, 51.3% of sheep and 14.8% of goats were found infected with Fasciola spp. The prevalence rate varied from 66.6 to 100.0%, 25.0 to 100% and nil to 66.0% in cattle, sheep and goats respectively in different months of the year. Fasciola gigantica was the predominant species in all animal species but sheep harboured both F. gigantica and F. hepatica. The prevalence of F. hepatica infection in sheep happens to be the first report from India. Lymnaea auricularia sensu stricto supported the development of F. gigantica under laboratory conditions. The incubation temperature affected the shedding of the cercariae. Snails maintained at 25-27 degrees C started cercarial shedding as early as day 20 post-infection (PI), whereas those maintained at 10-12 degrees C commenced it from day 64 PI. One out of three experimentally infected guinea pigs aged 1 month revealed adult flukes in the liver at necropsy on day 52 PI.

Indirect fluorescent antibody test for the detection of antibodies to Echinococcus granulosus in experimentally infected pups.

Adult parasites of Echinococcus granulosus of buffalo origin were used as antigen in the indirect fluorescent antibody test (IFA) for detection of antibodies to E. granulosus in experimentally infected pups. The technique permitted detection of antibodies on Day 5 post-infection (p.i.) and up to Day 80 p.i. in infected animals. The antigen-antibody reaction was characterized by the appearance of a specific brilliant greenish yellow fluorescence on the embryophore of mature eggs present within and outside the gravid segment of the cestode. A maximum antibody titre of 1:320 at Day 50 p.i. was observed in the infected pups, coinciding with maturation of adult worms in the intestine of the host.

Echinococcus granulosus in animals in northern India.

The prevalence of larval Echinococcus granulosus in buffaloes, sheep and goats and in adult stray and shepherd dogs was studied in northern India. A total of 48.1% of 754 buffaloes, 30.5% of 1215 sheep and 21.0% of 447 goats were found to be infected with this parasite. The prevalence of infection in buffaloes was higher in older animals than in younger animals. The lungs and livers appeared to be the sites of predilection. A high percentage of cysts from buffaloes (71.1%) were sterile, whereas a high percentage (90.0%) of cysts from sheep and goats were fertile. Shepherd dogs showed a higher prevalence of infection than stray dogs and the latter examined near the vicinity of slaughter houses had a higher prevalence of infection than those examined in other parts of the city.

Control of sheep lungworm in India.

Lungworm infections (parasitic bronchitis) of sheep and goats are widely prevalent in hilly regions of India and neighbouring countries. Several species of strongyloid nematodes are involved but the most prevalent, and most pathogenic, is Dictyocaulus filaria - responsible for heavy mortality in young animals and severe morbidity in survivors. Control of these parasites now relies on a gamma-attenuated D. filaria vaccine developed in India in 1971. Vaccination of 6-week-old lambs has since become an accepted part of the regular sheep husbandry practice in India, and trials are now underway to extend use of the vaccine to goats, and to set up similar vaccination procedures in other countries. In this review, the authors trace the development of the D. filaria vaccine, highlighting its production and application. Although imperfect, the vaccine is now making a substantial contribution to improved sheep rearing by pastoral in the northern hill areas of India.

Preliminary observations on the effect of Dictyocaulus filaria on the blood clotting time of sheep.

The whole blood clotting time progressively increased from the second to the eighth week in lambs receiving a primary infection of Dictyocaulus filaria larvae. However, in vaccinated lambs it remained unaffected. Levamisole hydrochloride was ineffective when given 4 days after infection but restored the blood clotting time to near normal soon after treatment when it was given 30 days after infection.

Establishment of Ascaridia galli in betamethasone-treated chickens.

Twenty-five day-old White Leghorn chickens were each infected orally with 500 (Group I), 1000 (Group II) and 2000 (Group III) infective eggs of Ascaridia galli and were killed 30 days after the infection. A high percentage of the infecting dose (6.5%) established as adult worms in the intestine of chickens receiving the lowest level of primary infection, but as the amount of primary infection given to birds increased, there was a significant fall in the percentage establishment of adult worms in the intestine. A similar pattern of worm establishment was shown by chickens of the same age and receiving similar levels of primary infections, but which were treated with betamethasone at a dose of 2 mg/kg body weight commencing 5 days before and continuing up to 15 days after the infection. Betamethasone-treated birds, however, showed more establishment of worms in the intestine, but lower weight gains in comparison to the birds which were not treated. Different levels of primary infections given, with or without treatment with betamethasone, had no effect on the sex ratio of the resultant male/female worm populations, which became established in almost equal numbers in the intestine of chickens.

Serum lactate dehydrogenase: clinical significance of alterations in its activity in lambs infected with Dictyocaulus filaria.

Alterations in the serum lactate dehydrogenase activity of Dictyocaulus filaria infected lambs were studied. The significant increase in its activity during patency correlated well with the progress of the disease and lung damage caused by the parasite. The enzyme may be of use in assessing the potency of D filaria vaccine and the chemotherapeutic value of an anthelmintic. Its use as a non-invasive method for earlier diagnosis and prognosis of the disease under experimental conditions is suggested.

Specificity of fungal lipase in hydrolytic cleavage of oil.

Lipase isolated from the fungus Fusarium oxysporum f. sp. lini has shown specificity to saturated acids. In vitro hydrolytic splitting of cotton seed, ground-nut and fungal (F. oxysporum) oil substrates by the enzyme preparation from this fungus, revealed preferential fatty acid specificity. The enzyme attacked the triglyceride molecule, liberating 90-97% of saturated fatty acids, irrespective of length of the carbon chain.

Oesophagostomum columbianum: gamma-irradiated third-stage larvae for immunization in lambs.

40-kR gamma-irradiated third-stage larvae of Oesophagostomum columbianum were used for the immunization of Kashmir Merino lambs. Male lambs (aged from 8 to 12 weeks) were immunized in two separate experiments by two doses of irradiated larvae, given 21 days apart, and subsequently challenged with normal larvae. Judging by the establishment of worms resulting from the challenge infections in the immunized and control groups of lambs in the two experiments, a high degree of immunity was shown to develop in young lambs vaccinated with 500, followed 21 days later with 2000, 40-kR irradiated larvae. Lambs from the immunized groups showed more nodules in the intestine, a high percentage of which were positive for histotrophic stages of O. columbianum, than did controls. The importance of this finding in relation to the possible use of a vaccine for the immuno-prophylaxis of oesophagostomiasis in sheep and other animals is discussed.

Gastro-intestinal nematodes in sheep in Kashmir.

Examination at necropsy of the abomasum and intestinal tract of 62 sheep (including both sexes) of Karnah breed, aged one to two years over a period of one year was conducted at Handwara, situated in the north-west of Kashmir Valley. The following species of nematodes were found: Haemonchus contortus, Trichostrongylus axei, Trichostrongylus colubriformis, Bunostomum trigonocephalum, Chabertia ovina, Nematodirus spathiger, Skrjabinema ovis and Trichuris ovis. Infections with Trichostrongylus axei and T. colubriformis were, respectively, 57.7 and 40.2% of the total of all nematodes recovered. Faecal examination of adult sheep of Karnah breed, aged two to four years, comprising mostly pregnant and lactating ewes, showed a rise in strongyle egg counts during the months of March and April, coinciding with the lambing season in the area. The lambs showed a rise in faecal strongyle egg output from May onwards. The counts reached their peak during the month of September. It is presumed that pastures contaminated by pregnant and lactating ewes during the spring season were responsible for the acquisition of heavy nematode infections by lambs in the area.

Immunization with irradiated larvae against Dictyocaulus filaria in young lambs.

In the lungworm-endemic areas of Kashmir, 6-10 week old lambs of Karnah and Kashmir Merino breeds were vaccinated with two doses of 50 kR gamma-irradiated larvae of Dictyocaulus filaria, given a month apart. Assessed on the basis of reduced prevalence and significantly lower faecal larval output over an eight-month observation period, vaccinated lambs showed a high degree of resistance to naturally acquired D. filaria infection. The results also show that vaccination against D. filaria provided some degree of protection against infection with other lungworm species.

Immunization of lambs against Oesophagostomum columbianum, using irradiated third stage larvae.

The effect of gamma irradiation at doses of 40- and 50 kR on the development of third stage larvae of Oesophagostomum columbianum and the protection conferred by these irradiated larvae against the nematode, was studied in 6-8 week old male Kashmir Merino lambs. At 40- and 50 kR doses, the third stage larvae failed to develop to the adult stage in the intestine. Though single vaccination with 2000, 50 kR irradiated larvae failed to protect the animals against the infection, vaccination with the same number of 40 kR irradiated larvae conferred a partial protection. The presence of adult worms of O. columbianum in sites outside the intestine of 6-8 week old lambs have been demonstrated for the first time.