Seasonal analysis of food items and feeding habits of endangered riverine catfish Rita rita (Hamilton, 1822) / Análise sazonal de itens e hábitos alimentares de bagres ribeirinhos Rita rita (Hamilton, 1822) ameaçados de extinção

This investigation presents the food and feeding activity of and endangered riverine catfish Rita rita, during February 2017-January 2018. A total of 225 fish individuals was analyzed for stomach contents by characterizing the dominant food items and morphometric features. The results divulged ten major food items consumed, preferably fish scales and eggs, teleost fishes, copepods, cladocerans, rotifers, and mollusks. Total length and body weight of fish varied between 9-34 cm (20.53 ± 6.90 cm) and 10-400 g (9125.94 ± 102.07 g), respectively. The index of relative importance (IRI%) showed the importance of rotifers over the other food items. Morisita's index of diet overlap indicated seasonal variations in catfish diets with summer and monsoon displaying the least overlap, while maximum overlap during monsoon and winter seasons. The non-metric multidimensional scaling (nMDS) indicated the close association between the food items available during summer and winter seasons with a significant difference among the seasons (ANOSIM, R = 0.638, P = 0.013). Levin's niche breadth index arranged in the order of 0.88>0.81>0.78>0.63>0.43 for the size classes of V, IV, III, II and I, respectively. The PCA explained 95.39% of the total variance among the food items and fish size groups. Small-sized fish individuals displayed a greater correlation with food items suitable for their mouth size. In conclusion, the variety and frequency of food items recorded indicated considerable feeding plasticity and opportunistic feeding behavior with a shift from carnivorous to omnivorous feeding nature. This study could render useful information on the food and feeding habits of R. rita and provide background for preparing its diet for future aquaculture practices.

Esta investigação apresenta a alimentação e a atividade alimentar de bagres ribeirinhos Rita rita ameaçados de extinção, no período de fevereiro de 2017 a janeiro de 2018. Um total de 225 peixes foi analisado quanto ao conteúdo do estômago, caracterizando os itens alimentares dominantes e as características morfométricas. Os resultados apresentaram dez principais itens alimentares consumidos, preferencialmente escamas e ovos de peixes, teleósteos, copépodes, cladóceros, rotíferos e moluscos. O comprimento total e o peso corporal dos peixes variaram entre 9-34 cm (20,53 ± 6,90 cm) e 10-400 g (9125,94 ± 102,07 g), respectivamente. O índice de importância relativa (IRI%) mostrou a importância dos rotíferos sobre os demais itens alimentares. O índice de sobreposição de dieta de Morisita indicou variações sazonais nas dietas de bagres no verão e nas monções, exibindo a menor sobreposição, enquanto a sobreposição máxima ocorreu durante as estações das monções e do inverno. A escala multidimensional não métrica (nMDS) indicou a estreita associação entre os itens alimentares disponíveis durante o verão e o inverno, com uma diferença significativa entre as estações (ANOSIM, R = 0,638, P = 0,013). O índice de amplitude de nicho de Levin foi organizado na ordem de 0,88 > 0,81 > 0,78 > 0,63 > 0,43 para as classes de tamanho de V, IV, III, II e I, respectivamente. O PCA explicou 95,39% da variação total entre os itens alimentares e os grupos de tamanho de peixes. Peixes de pequeno porte apresentaram maior correlação com itens alimentares adequados ao tamanho da boca. Em conclusão, a variedade e a frequência dos itens alimentares registrados indicaram plasticidade alimentar considerável e comportamento alimentar oportunista, com uma mudança da natureza carnívora para onívora. Este estudo pode fornecer informações úteis sobre os hábitos alimentares e de alimentação de R. rita e apresentar subsídios para a preparação de sua dieta em futuras práticas de aquicultura.

Seasonal analysis of food items and feeding habits of endangered riverine catfish Rita rita (Hamilton, 1822) / Análise sazonal de itens e hábitos alimentares de bagres ribeirinhos Rita rita (Hamilton, 1822) ameaçados de extinção

This investigation presents the food and feeding activity of and endangered riverine catfish Rita rita, during February 2017-January 2018. A total of 225 fish individuals was analyzed for stomach contents by characterizing the dominant food items and morphometric features. The results divulged ten major food items consumed, preferably fish scales and eggs, teleost fishes, copepods, cladocerans, rotifers, and mollusks. Total length and body weight of fish varied between 9-34 cm (20.53 ± 6.90 cm) and 10-400 g (9125.94 ± 102.07 g), respectively. The index of relative importance (IRI%) showed the importance of rotifers over the other food items. Morisita's index of diet overlap indicated seasonal variations in catfish diets with summer and monsoon displaying the least overlap, while maximum overlap during monsoon and winter seasons. The non-metric multidimensional scaling (nMDS) indicated the close association between the food items available during summer and winter seasons with a significant difference among the seasons (ANOSIM, R = 0.638, P = 0.013). Levin’s niche breadth index arranged in the order of 0.88>0.81>0.78>0.63>0.43 for the size classes of V, IV, III, II and I, respectively. The PCA explained 95.39% of the total variance among the food items and fish size groups. Small-sized fish individuals displayed a greater correlation with food items suitable for their mouth size. In conclusion, the variety and frequency of food items recorded indicated considerable feeding plasticity and opportunistic feeding behavior with a shift from carnivorous to omnivorous feeding nature. This study could render useful information on the food and feeding habits of R. rita and provide background for preparing its diet for future aquaculture practices.

Esta investigação apresenta a alimentação e a atividade alimentar de bagres ribeirinhos Rita rita ameaçados de extinção, no período de fevereiro de 2017 a janeiro de 2018. Um total de 225 peixes foi analisado quanto ao conteúdo do estômago, caracterizando os itens alimentares dominantes e as características morfométricas. Os resultados apresentaram dez principais itens alimentares consumidos, preferencialmente escamas e ovos de peixes, teleósteos, copépodes, cladóceros, rotíferos e moluscos. O comprimento total e o peso corporal dos peixes variaram entre 9-34 cm (20,53 ± 6,90 cm) e 10-400 g (9125,94 ± 102,07 g), respectivamente. O índice de importância relativa (IRI%) mostrou a importância dos rotíferos sobre os demais itens alimentares. O índice de sobreposição de dieta de Morisita indicou variações sazonais nas dietas de bagres no verão e nas monções, exibindo a menor sobreposição, enquanto a sobreposição máxima ocorreu durante as estações das monções e do inverno. A escala multidimensional não métrica (nMDS) indicou a estreita associação entre os itens alimentares disponíveis durante o verão e o inverno, com uma diferença significativa entre as estações (ANOSIM, R = 0,638, P = 0,013). O índice de amplitude de nicho de Levin foi organizado na ordem de 0,88 > 0,81 > 0,78 > 0,63 > 0,43 para as classes de tamanho de V, IV, III, II e I, respectivamente. O PCA explicou 95,39% da variação total entre os itens alimentares e os grupos de tamanho de peixes. Peixes de pequeno porte apresentaram maior correlação com itens alimentares adequados ao tamanho da boca. Em conclusão, a variedade e a frequência dos itens alimentares registrados indicaram plasticidade alimentar considerável e comportamento alimentar oportunista, com uma mudança da natureza carnívora para onívora. Este estudo pode fornecer informações úteis sobre os hábitos alimentares e de alimentação de R. rita e apresentar subsídios para a preparação de sua dieta em futuras práticas de aquicultura.

Seasonal analysis of food items and feeding habits of endangered riverine catfish Rita rita (Hamilton, 1822)

Abstract This investigation presents the food and feeding activity of and endangered riverine catfish Rita rita, during February 2017-January 2018. A total of 225 fish individuals was analyzed for stomach contents by characterizing the dominant food items and morphometric features. The results divulged ten major food items consumed, preferably fish scales and eggs, teleost fishes, copepods, cladocerans, rotifers, and mollusks. Total length and body weight of fish varied between 9-34 cm (20.53 ± 6.90 cm) and 10-400 g (9125.94 ± 102.07 g), respectively. The index of relative importance (IRI%) showed the importance of rotifers over the other food items. Morisitas index of diet overlap indicated seasonal variations in catfish diets with summer and monsoon displaying the least overlap, while maximum overlap during monsoon and winter seasons. The non-metric multidimensional scaling (nMDS) indicated the close association between the food items available during summer and winter seasons with a significant difference among the seasons (ANOSIM, R = 0.638, P = 0.013). Levins niche breadth index arranged in the order of 0.88>0.81>0.78>0.63>0.43 for the size classes of V, IV, III, II and I, respectively. The PCA explained 95.39% of the total variance among the food items and fish size groups. Small-sized fish individuals displayed a greater correlation with food items suitable for their mouth size. In conclusion, the variety and frequency of food items recorded indicated considerable feeding plasticity and opportunistic feeding behavior with a shift from carnivorous to omnivorous feeding nature. This study could render useful information on the food and feeding habits of R. rita and provide background for preparing its diet for future aquaculture practices.

Resumo Esta investigação apresenta a alimentação e a atividade alimentar de bagres ribeirinhos Rita rita ameaçados de extinção, no período de fevereiro de 2017 a janeiro de 2018. Um total de 225 peixes foi analisado quanto ao conteúdo do estômago, caracterizando os itens alimentares dominantes e as características morfométricas. Os resultados apresentaram dez principais itens alimentares consumidos, preferencialmente escamas e ovos de peixes, teleósteos, copépodes, cladóceros, rotíferos e moluscos. O comprimento total e o peso corporal dos peixes variaram entre 9-34 cm (20,53 ± 6,90 cm) e 10-400 g (9125,94 ± 102,07 g), respectivamente. O índice de importância relativa (IRI%) mostrou a importância dos rotíferos sobre os demais itens alimentares. O índice de sobreposição de dieta de Morisita indicou variações sazonais nas dietas de bagres no verão e nas monções, exibindo a menor sobreposição, enquanto a sobreposição máxima ocorreu durante as estações das monções e do inverno. A escala multidimensional não métrica (nMDS) indicou a estreita associação entre os itens alimentares disponíveis durante o verão e o inverno, com uma diferença significativa entre as estações (ANOSIM, R = 0,638, P = 0,013). O índice de amplitude de nicho de Levin foi organizado na ordem de 0,88 > 0,81 > 0,78 > 0,63 > 0,43 para as classes de tamanho de V, IV, III, II e I, respectivamente. O PCA explicou 95,39% da variação total entre os itens alimentares e os grupos de tamanho de peixes. Peixes de pequeno porte apresentaram maior correlação com itens alimentares adequados ao tamanho da boca. Em conclusão, a variedade e a frequência dos itens alimentares registrados indicaram plasticidade alimentar considerável e comportamento alimentar oportunista, com uma mudança da natureza carnívora para onívora. Este estudo pode fornecer informações úteis sobre os hábitos alimentares e de alimentação de R. rita e apresentar subsídios para a preparação de sua dieta em futuras práticas de aquicultura.

Can Costus afer be used for co-treatment of COVID-19, its symptoms and comorbidities? A novel approach for combating the pandemic and implications for sub-Saharan Africa

@#Despite the huge loss of lives and massive disruption of the world economy by the COVID-19 pandemic caused by SARS-CoV-2, scientists are yet to come out with an effective therapeutic against this viral disease. Several vaccines have obtained ‘emergency approval’, but difficulties are being faced in the even distribution of vaccines amongst high- and lowincome countries. On top of it, comorbidities associated with COVID-19 like diabetes, hypertension and malaria can seriously impede the treatment of the main disease, thus increasing the fatality rate. This is more so in the context of sub-Saharan African and south Asian countries. Our objective was to demonstrate that a single plant containing different phytoconstituents may be used for treatment of COVID-19 and comorbidities. Towards initial selection of a plant, existing scientific literature was scanned for reported relevant traditional uses, phytochemicals and pharmacological activities of a number of plants and their phytoconstituents pertaining to treatment of COVID-19 symptoms and comorbidities. Molecular docking studies were then performed with phytochemicals of the selected plant and SARS-CoV-2 components – Mpro, and spike protein receptor binding domain and hACE2 interface using AutoDock Vina. We showed that crude extracts of an indigenous African plant, Costus afer having traditional antidiabetic and antimalarial uses, has phytochemicals with high binding affinities for Mpro, and/or spike protein receptor binding domain and hACE2 interface; the various phytochemicals with predicted high binding energies include aferoside C, dibutyl phthalate, nerolidol, suginal, and ±-terpinene, making them potential therapeutics for COVID-19. The results suggest that crude extracts and phytochemicals of C. afer can function as a treatment modality for COVID-19 and comorbidities like especially diabetes and malaria.

Potential role of flavonoids against SARS-CoV-2 induced diarrhea

@#COVID-19, caused by the SARS-CoV-2 virus, can lead to massive inflammation in the gastrointestinal tract causing severe clinical symptoms. SARS-CoV-2 infects lungs after binding its spike proteins with alveolar angiotensin-converting enzyme 2 (ACE2), and it also triggers inflammation in the gastrointestinal tract. SARS-CoV-2 invades the gastrointestinal tract by interacting with Toll-like receptor-4 (TLR4) that induces the expression of ACE2. The influx of ACE2 facilitates cellular binding of more SARS-CoV-2 and causes massive gastrointestinal inflammation leading to diarrhea. Diarrhea prior to COVID-19 infection or COVID-19-induced diarrhea reportedly ends up in a poor prognosis for the patient. Flavonoids are part of traditional remedies for gastrointestinal disorders. Preclinical studies show that flavonoids can prevent infectious diarrhea. Recent studies show flavonoids can inhibit the multiplication of SARS-CoV-2. In combination with vitamin D, flavonoids possibly activate nuclear factor erythroid-derived-2-related factor 2 that downregulates ACE2 expression in cells. We suggest that flavonoids have the potential to prevent SARS-CoV-2 induced diarrhea.

Screening and Production of Biodegradable Polyester Poly(3-hydroxybutyrate) by Bacteria Endophytic to Brassica nigra L.

Aims: Poly(3-hydroxybutyrate) [P(3HB)], the microbially produced biodegradable thermoplastics has find wide range of applications in recent years. Development of low cost production strategies utilizing novel organisms is a crucial challenge. Present study is aimed to isolate and screen bacterial endophytes of Brassica nigra L. for the production of P(3HB). Place and Duration of Study: The experiments were performed in the Microbiology Laboratory, Department of Botany, University of Calcutta, Kolkata during 2012-2014. Methodology: Culturable bacterial endophytes were isolated from surface sterilized healthy tissues of B. nigra L. and screened for P(3HB) production in mineral salts medium. The chloroform extracted dried polymer was treated with H2SO4 and quantified spectrophotometrically at 235 nm. Results: About 78% of the bacterial endophytes recovered from surface sterilized B. nigra L. tissues showed different degrees of P(3HB) accumulation. Isolates (9) showing P(3HB) accumulation exceeding 10% of the cell dry weight (CDW) were characterized and tentatively identified as members of Bacillus, Pseudomonas, Xanthomonas, Alcaligenes and Acetobacter. The most potent isolate, BNL 06 identified as Bacillus pumilus BNL 06 (GenBank Accession No. KP202723), accumulated P(3HB) accounting 18% of CDW with an yield of 0.55 g/l. Finally the nature of the polymer was further confirmed by FTIR analysis. Conclusion: Exploration of the endophytic bacterial diversity of B. nigra L. have clearly revealed the potential of Bacillus pumilus BNL 06 for P(3HB) production as an alternative source of thermoplastics.

Production of Extracellular Enzymes by Halophilic Bacteria Isolated from Solar Salterns.

During the course of survey of halophilic microorganisms, a total of sixteen bacterial isolates were obtained from coastal solar salterns of Orissa and West Bengal, India. Morphological, physiological and biochemical characteristics of these isolates indicate that majority of them belong to the genus Halomonas, however, members belonging to Cobetia and Halococcus were not uncommon. These isolates were screened for the production of extracellular enzymes such as amylase, glutaminase, asparaginase, xylanase, cellulase, gelatinase, inulinase, caseinase, pectinase, urease and lipase. Among these hydrolytic enzymes, glutamine and asparagine hydrolytic activities were predominant, although lipid and casein degrading activities were not inferior. However, amylase and gelatinase production were rare. None of these halophiles was able to degrade cellulose, inulin, pectin and xylan and only one isolate was capable of hydrolyzing urea.

Bacterial Endophytes of the Medicinal Herb Hygrophila spinosa T. Anders and Their Antimicrobial Activity.

Aims: The ethnobotanical herb Hygrophila spinosa T. Anders (Acanthaceae) is native to India and used in traditional ayurvedic medicines for its pharmacologically important phytochemicals. This study aims to isolate and characterize the culturable bacterial endophytes of H. spinosa and evaluate their antimicrobial properties. Place and Duration of Study: The experiments were performed in the Department of Botany, Serampore College, Serampore as well as in the Microbiology Laboratory, Department of Botany, University of Calcutta, Kolkata during 2011 to 2012. Methodology: Bacterial endophytes were isolated from healthy plant tissues following surface sterilization and plating on nutrient agar, glycerol asparagine agar and tryptic soy agar. They were characterized physio-biochemically following standard microbiological and biochemical methods. The endophytes were screened for production of antimicrobial compounds following cross-streak assay against test strains Bacillus subtilis, B. cereus, Escherichia coli, Pseudomonas cepacia, Klebsiella pneumoniae and Staphylococcus aureus on nutrient agar plates. Results: Eleven phenotypically distinguishable bacterial endophytes were isolated from surface sterilized leaf, stem and root tissues and Shannon Weaver diversity index clearly revealed more diverse (0.83) types of endophytes in leaves than in stem (0.48) and root (0.41) tissues. Physio-biochemical features of the isolates clearly indicated distinct variation in their sugar fermentation profiles along with NaCl tolerance. The endophytes produced important enzymes like catalase, amylase, gelatinase, nitrate reductase and lipase. The bacterial isolates belonged to the genera Bacillus, Paenibacillus, Pseudomonas, Ralstonia, Staphylococcus, Micrococcus and Acidomonas. Antibiotic sensitivity profile, however, have indicated that the isolates were mostly resistant to amoxycillin and bacitracin, while they were highly susceptible to tetracycline followed by neomycin and streptomycin. Interestingly, the bacterial endophytes of H. spinosa give a definite stamp on their antimicrobial activity against E. coli and K. pneumoniae followed by S. aureus. Two isolates, Paenibacillus HGS 202 and Acidomonas HGR 302 obtained from stem and root segments respectively showed antimicrobial activity against B. subtilis, B. cereus, E. coli, K. pneumoniae and S. aureus. Conclusion: This study identified 11 bacterial endophytes harbored by the leaves, stem and root of H. spinosa which demonstrated antibacterial activity against Gram-positive as well as Gram-negative bacterial strains. Moreover these endophytic bacterial isolates could be exploited as sources of antibacterial substances.

"Nonunion of Adult Humerus Fracture" - Management Using the Ilizarov External Fixator.

Humeral shaft fractures occur about three percent of all fractures in adults. A very high union rate is achieved with non-operative treatment, however when nonunion occurs conservative approach or after operative management they are often very difficult to treat, and often requires multiple procedures to achieve union. Even with multiple procedures, true pseudoarthrosis have only a 59% union rate. The aim of this study was to find out the results of such complicated cases treating with Ilizarov's external fixator. We conducted a prospective study of eleven patients with nonunion humeral shaft fracture in adult wherein the outcome of the treatment was analyzed. In our series we achieved union in all of the cases with a mean of 29.1 weeks with negligible complications like pin tract infections and in one case refracture occur due to forceful manipulation. So it can be concluded that Ilizarov's method is an excellent option for the treatment of nonunion of diaphyseal fracture of the humerus.

Evaluation of in vitro Reduction of Hexavalent Chromium by Cell-Free Extract of Arthrobacter sp. SUK 1201.

Aims: This study aims at to evaluate the hexavalent chromium [Cr(VI)] reduction potential of crude cell-free extracts of chromium resistant and reducing bacterium Arthrobacter sp. SUK 1201 and determination of optimum conditions for Cr(VI) reduction for possible bioremediation of Cr pollutants. Place and Duration of Study: Chromium reduction studies with Arthrobacter sp. SUK 1201, was undertaken in the Microbiology Laboratory, Department of Botany, University of Calcutta, Kolkata during 2010-2012. Methodology: Cell-free extract was prepared from freshly grown cell mass of Arthrobacter sp. SUK 1201 following the standard procedure. Cell mass suspended in Tris-HCl was sonicated (120 KHz for 30 min), centrifuged (12,000×g at 4ºC for 10 min) and the supernatant (S12) was used as the cell- free extract (CFE). Chromate reductase activity of the CFE was assayed colorimetrically using 1, 5-diphenylcarbazide as the complexing reagent. Results: Chromate reductase activity of CFE of Arthrobacter sp. SUK 1201 was constitutive in nature and reduced Cr(VI) with decreasing efficiency as the concentration of Cr(VI) was increased. Its Km and Vmax were 263.45 M Cr(VI) and 17.5 U mg-1 protein respectively. Reduction of Cr(VI) was optimal at pH 7 and 32ºC but was extremely thermolabile. NADH was the most suitable electron donor, and the chromate reduction was enhanced by Cu(II) and Fe(III), but inhibited by Hg(II). Among the different inhibitors tested, 2, 4-dinitrophenol (DNP) restored nearly 96.4% reductase activity, while carbonyl cyanidem- chloro phenyl hydrazone (CCCP) was most inhibitory to the process. Conclusion: It has been established that the Cr(VI) reduction potential of the cell-free extract of Arthrobacter sp. SUK 1201 is promising and could be exploited in the bioremediation of toxic hexavalent chromium.

Hexavalent chromium reduction by aerobic heterotrophic bacteria indigenous to chromite mine overburden

Microbiological analysis of overburden samples collected from chromite mining areas of Orissa, India revealed that they are rich in microbial density as well as diversity and dominated by Gramnegative (58%) bacteria. The phenotypically distinguishable bacterial isolates (130) showed wide degree of tolerance to chromium (2-8 mM) when tested in peptone yeast extract glucose agar medium. Isolates (92) tolerating 2 mM chromium exhibited different degrees of Cr+6 reducing activity in chemically defined Vogel Bonner (VB) broth and complex KSC medium. Three potent isolates, two belonging to Arthrobacter spp. and one to Pseudomonas sp. were able to reduce more than 50 and 80% of 2 mM chromium in defined and complex media respectively. Along with Cr+6 (MIC 8.6-17.8 mM), the isolates showed tolerance to Ni+2, Fe+3, Cu+2 and Co+2 but were extremely sensitive to Hg+2 followed by Cd+2, Mn+2 and Zn+2. In addition, they were resistant to antibiotics like penicillin, methicillin, ampicillin, neomycin and polymyxin B. During growth under shake-flask conditions, Arthrobacter SUK 1201 and SUK 1205 showed 100% reduction of 2 mM Cr+6 in KSC medium with simultaneous formation of insoluble precipitates of chromium salts. Both the isolates were also equally capable of completely reducing the Cr+6 present in mine seepage when grown in mine seepage supplemented with VB concentrate

Thyroid disorders in Khulna district: a community based study.

This study reports the prevalence of thyroid diseases and their relationship to autoimmunity in a population of Khulna district where goitre is not endemic. A survey was performed among citizens of a union of Khulna district. The study population consisted of a random sample of the students of primary schools, secondary schools and people of nearby areas. History taking, neck examination for goitre and blood examination for thyroid hormones was done from each subject. Blood sample was measured for thyroid hormones and thyroid microsomal antibody (TMAb) using radioimmunoassay method. Of the total 925 individual studied, 527 was female and 398 was male with age ranges from 2-62 years (mean 19.86 +/- 13.62 years). The overall occurrence of thyroid disease was estimated to be 20.43%. The spectrum of thyroid disorders showed highest incidence of diffuse goitre (7.35%), followed by sub-clinical hypothyroidism (6.59%), hypothyroidism (4.97%), hyperthyroidism (0.86%) and sub-clinical hyperthyroidism (0.65%). The incidence of thyroid disorders was observed to be highest in the 11-45 years age group (79.89%). Female outnumbered male, the ratio being 2.5:1 with preponderance of female subjects in all disease groups. The prevalence of all goitre was 10.49%. TMAb estimation was performed in 318 samples, of them 48 cases (15.09%) was found to be autoimmune thyroid disease. Of the total sub-clinical and overt hypothyroidism, the incidence of autoimmune thyroid disease was 29.29% and non-goitrous thyroid dysfunction was more common than goitrous one. Three of 38 (7.89%) euthyroid goitrous subjects showed positive antibody. Interestingly, 16 of 181 (8.84%) individual had a positive antibody, which was considered normal by neck examination. Goitre prevalence of 10.49% in this study indicates the region to be a mild iodine deficient area. Chronic autoimmune disease is likely to be one of the etiological factors for thyroid disorders in this southern zone.

Growth-associated production and characterization of poly (3-hydroxybutyric acid) of Azotobacter beijerinckii DAR-102.

Production of poly (3-hydroxybutyric acid) [P(3HB)] by Azotobacter beijerinckii DAR-102 isolated in this laboratory has been optimized under batch-culture. The accumulatad polymer attained 58% of cell dry mass during mid-stationary phase with an yield of 0.58 g/l when grown in nitrogen-free medium. The optimum concentration of glucose and fructose for P(3HB) production was 3% (w/v) and 2% (w/v) respectively while that of casamino acid and tryptose was 0.1% (w/v). Phosphate at a concentration suboptimal for growth and limitation of oxygen in the medium favoured P(3HB) accumulation. The production of P(3HB) was maximum with an inoculum dose of 4% (v/v). The accumulated polymer was isolated by direct chloroform extraction of the dry cell mass and purified by precipitation with diethyl ether. The purified polymer has been characterized in terms of its solubility properties, melting temperature, and UV-, IR- and NMR-spectroscopic analyses.

Micropropagation of sweet orange, Citrus sinensis Osbeck. for the development of nucellar seedlings.

Protocol for micropropagation of elite plants of sweet orange (Citrus sinensis) through nucellar embryo culture has been standardized. Three to four nucellar embryos and a zygotic embryo could be excised from a single mature seed and successfully generated as healthy plants in basal MS medium. MS medium supplemented with NAA (1 mg/L) or 2, 4.D (1 mg/L) promoted callus development in both nucellar and zygotic embryos. GA3 (1 mg/L) enriched medium induced plantlets initiation but their growth was very poor. No significant differences were observed between initial growth patterns of nucellar and zygotic seedlings developing from the same ovule. Five to six shoots were obtained from collar region of both category of embryos in MS medium supplemented with BAP (1 mg/L) within 60 days of inoculation. The number of plantlets were almost doubled after their transfer in the same medium and culture for another 30 days. Higher doses of BAP resulted in initiation of callus directly from the embryos. The regenerated shoots (2-3 cm) could be rooted in MS medium supplemented with either only NAA (0.75 mg/L) or NAA (0.50 mg/L) and IBA (2.0 mg/L). A number of plantlets could be obtained from a nucellar embryo grown shoot within a limited time period.

Exopolysaccharide production by some rhizobium strain in culture.

Eight Rhizobium strains were screened for exopolysaccharide production during growth in yeast extract mannitol medium. A strain of Rhizobium loti produced more than 250 mg of exopolysaccharide/100 ml of culture during the stationary phase of growth. Exopolysaccharide production was favoured by maltose and mannitol but N2 supplementation could not affect the production siginificantly. Preliminary studies indicate that the polymer contains 16% protein and 73.5% carbohydrate being composed of glucose, galactose and glucuronic acid.

Clinical experiences with vecuronium in children.

The neuromuscular blocking effects of vecuronium have been investigated clinically in children regarding its efficacy and safety. The drug is given either of the two doses--0.08 mg/kg body weight or 0.1 mg/kg body weight in 40 children as a single intravenous bolus injection for endotracheal intubation. Vecuronium in doses of 0.1 mg/kg body weight provided satisfactory clinical relaxation for ideal intubating conditions in all children in reference to the ease of intubation, intermediate duration of action, spontaneous or easy reversal of the neuromuscular block, cardiovascular stability and absence of serious side-effects. Thus vecuronium may be regarded as a useful muscle relaxant in paediatric anaesthesia.

Trimeprazine as oral premedication in children.

The effect of oral trimeprazine alone or in combination with either atropine or glycopyrrolate or pethidine as oral premedication in children was studied. The effects of different drug combinations were evaluated in respect of pre-operative sedation, salivary secretion, induction characteristic, postoperative sedation and postoperative vomiting. The study concludes that trimeprazine in combination with either atropine or glycopyrrolate is mostly effective, safe and satisfactory as oral premedication in children. Trimeprazine along with pethidine can be recommended for all purpose oral medication both in pre- and post-operative period.