Human serum for in vitro cultivation of Babesia bovis

Various combinations of human serum (from blood of groups A and Rhesus positive) with bovine serum, i.e. 20% + 20% (Medium I), 30% + 10% (II), 40% + 0% (III) and 0% + 40% (IV) and Medium-199 (60%) were used in the propagation of Babesia bovis. Babesia bovis stabilate revived by inoculation in a bovine calf was used at a level of 6% parasitized erythrocytes (PPE). The medium was replenished every 24 h. The medium changed from bright red to dark-coffee color every 24 h. The increase in PPE was maximal between 24 and 48 h. It was also observed that the increase in PPE was significantly higher in a 1:2 dilution compared with a 1:1 dilution. The increase in PPE was highest in Medium I with a 50% replacement of bovine with human serum. However, the parasites could not be subcultured and maintained continuously. Fifty percent replacement was thus optimal for the human-bovine serum combination in a microaerophilous stationary phase (MASP) system. The results indicate that B. bovis can also multiply in a human/bovine serum MASP culture system at least for a period of 48 h, and this is consistent with the zoonotic nature of Babesia species.

Taxonomic relationship of some members of Azotobacteraceae based on their protein profiles

Analysis of protein profiles of the members of Azotobacteraceae suggests that the genus Azotobacter consists of a heterogeneous group of bacteria, of which Azotobacter beijerinekii should possibly be separated to a new genus. Azomonas agilis and Azomonas macrocytogenes are only 26 percent related to each other.

Fungitoxic properties of Prunus persica oil

During screening of leaves of 15 higher plant species, the leaves of Prunus persica exhibited absolute inhibition of mycelial growth of Aspergillus flavus. The active fraction was isolated in form of an essential oil which exhibited fungistatic nature at its minimum inhibitory concentration of 0.1% and showed a broad antifungal range. The oil was found non-phytotoxic to the seedling growth and seed germination of wheat.

Treatment of bovine tropical theileriosis with buparvaquone

The antitheilerial activity of buparvaquone in crossbred male calves, experimentally infected with Theileria annulata (Izatnagar isolate) has been tested. Animals were treated intramuscularly at the dose rate of 2.5 mg/kg1 body weight. A single dose of the drug administered during the phase of ascending parasitaemia cured all the infected calves while all the untreated infected control calves died.

Bio-environmental control of malaria in a tribal area of Mandla district, Madhya Pradesh, India

Bizadandi block of District Mandla was selected for demonstration of bio-environmental control of malaria. The project presently covers 80 experimental villages and 12 control villages. In this area, because of indifferent surveillance and spraying in the past (from 1978-86) the API was reported low and the parasite reservoir in the community had built up over the years. At the outset of the study the malaria prevalence was high with preponderance of P. falciparum. Densities of A. culicifacies were very high and A. fluviatilis was also present. P. falciparum predominated in both experimental and control area during 1988 than in 1987. Annual blood examination rate (ABER) was 73.6 and 57.5 and annual parasite incidence (API) was 114.7 and 228.0 in experimental and control villages in 1987, while in 1988, ABER and API was 63 and 73 and 112 and 316 in experimental and control, respectively. There was constant stabilization of Pf in neighbouring blocks in 1988 while in experimental areas Pf percentage has come down appreciably during March to June. It is very alarming to note that the parasite reservoir in control villages was sufficient to maintain active transmission even when antimalarial activities are at a peak. The application of residual insecticides like DDT and HCH has no tangible impact on the reduction in vector densities and the transmission of malaria. Even if a replacement insecticide like malathion is used it may produce very limited impact on vector densities in such forested zones. Thus, there is an urgent need to intensify integrated malaria control operations in the area on long term basis.

Occurrence, identification and possible significance of ornithine lipid in Thiobacillus ferrooxidans

An ornithine containing aminolipid has been found in Thiobacillus ferrooxidans grown in ferrous sulfate medium, which was purified and estimated at four main phases of growth. GLC analysis of ornithine lipid has revealed the existence of mainly C18:1 and C22:1 fatty acids. The infrared spectra showed the existence of both amide and ester linkages in the aminolipid. The major ester linked fatty acid was C22:1. The interaction of ornithine lipid with membrane was investigated by delipidation of the membrane particles, which resulted in the perturbation of the activities of the three enzymes of iron oxidation system. The activities could be restored to the lipid depleted particles by preincubation with a dispersion of purified ornithine lipid together with coenzyme Q8. The kinetic parameters of the enzyme activities were also affected by delipidation which was significantly altered in the reconstituted particles by this lipid, thus indicating a possible role of ornithine lipid in iron oxidation system.

Permeable membrane/mass spectrometric measurement of solvent 1H/2H, 12C/13C, and 16O/18O kinetic isotope effects associated with alpha-chymotrypsin deacylation: evidence for reaction mechanism plasticity

We have measured, by permeable membrane/mass spectrometry, the 16O/18O, 12C/13C, and solvent H2O/D2O kinetic isotope effects (kie) associated with acyl-alpha-chymotrypsin hydrolysis and transesterification. The hydrolysis of alpha-chymotrypsinyl 2-furoate has a 12C/13C kie of approximately 1.06. Transesterification of the same acyl enzyme shows 16O/18O, 12C/13C, and solvent H2O/D2O kinetic isotope effects of 1.015 (0.003), 1.01-1.02, and 2.226 (0.007), respectively. From the temperature independence of the 16O/18O transesterification kinetic isotope effect and kinetic data reported elsewhere [Wang, C.-L. A., Calvo, K. C., & Klapper, M. H. (1981) Biochemistry 20, 1401-1408], we conclude that there are two active forms of acylchymotrypsin. We also propose that formation of the tetrahedral intermediate is the rate-limiting step in both hydrolysis and transesterification and that the position of the transition state in the transesterification is closer to the starting enzyme ester while that for the hydrolytic reaction is closer to the tetrahedral intermediate. These results are discussed in terms of reaction mechanism plasticity.

Effect of tryptophan on 2,4-dichlorophenoxyacetic acid toxicity in the nitrogen-fixing-cyanobacterium Nostoc linckia

The combined effect of a hormone weed killer 2,4-dichlorophenoxyacetic acid (2,4-D) and an amino acid (tryptophan) has been studied on growth and heterocyst differentiation in the cyanobacterium Nostoc linckia. 2.4-D at 100 micrograms/ml stimulated growth and heterocyst frequency in combined nitrogen-free medium while its higher concentrations inhibited both. Tryptophan under similar conditions promoted much growth yield with 3-4 fold enhanced heterocyst frequency than the control. Such heterocysts were immature and showed germination under in situ condition. The concentrations of 2,4-D (100 micrograms/ml) and tryptophan (50 micrograms/ml), stimulatory to growth and heterocyst formation, caused additive effect while herbicide inhibition of nitrogen-fixing growth at higher doses was partially relieved by tryptophan but tryptophan-induced heterocyst frequency was completely suppressed under this condition. The possible role of interaction of these two chemicals on growth and heterocyst formation has been discussed.

Induction of benzo(a)pyrene hydroxylase in Aspergillus ochraceus TS: evidences of multiple forms of cytochrome P-450

The filamentous fungus Aspergillus ochraceus TS produces an inducible microsomal cytochrome P-450 linked monooxygenase which is capable of hydroxylating benzo(a)pyrene in presence of O2 and NADPH. The addition of Benzo(a)pyrene, 3-Methyl cholanthrene, beta-Naphthoflavone and other aryl hydrocarbons during the induction period causes dramatic improvement in the kinetics of benzo(a) pyrene hydroxylation as was evidenced by large decrease in Km and increase in Vmax values. On the other hand, treatment with Phenobarbital, Polychlorinated biphenyl and Progesterone has no significant effect on the kinetics of benzo(a)pyrene hydroxylation although a significant induction of NADPH-Cyt C reductase activity was observed in all the three cases. Again, both Phenobarbital and 3-Methyl cholanthrene induced microsomes exhibit the characteristic reduced metyrapone difference spectra. These findings together with the results obtained with flavone on the metabolism of benzo(a)pyrene by various microsomal preparations suggest a parallel induction of multiple forms of cytochrome P-450 as observed in mammalian liver under identical condition.

Microsomal benzo(a)pyrene hydroxylase in Aspergillus ochraceus TS: assay and characterization of the enzyme system

Microsomal preparations of Aspergillus ochraceus TS oxidised benzo(a)pyrene very efficiently in the presence of NADPH and 02 and exhibits a pH optimum of 8.0-8.2. The hydroxylation is also effected in presence of NaI04. Hydroxylation was inhibited by metyrapone, SKF-525A, PCMB, imidazole, carbon monoxide and flavone but not by cyanide, azide and antimycin A indicating thereby the involvement of cytochrome P-450 in this reaction. Inhibition by cytochrome C is consistent with the participation of NADPH-cytochrome C reductase in this hydroxylation. Reduced microsomes and its solubilized preparation, when treated with carbon monoxide, showed absorption maxima at 453 and 449 respectively. Different classical inducers of cytochrome P-450 induce the benzo(a)-pyrene hydroxylase activity to varying degree and as such suggests the existence of multiple forms of cytochrome P-450 in this fungus.

Alcohol induced conformational transitions of proteins and polypeptides. Thermodynamic studies of some model compounds

Integral enthalpies of solution of diglycine in tert.-butyl alcohol + water and of diglycine and beta-alanine in ethanol + water mixtures were measured at 298.15 K as a function of alcohol concentration. Enthalpies of transfer of the solutes from water to aqueous alcohol mixtures were evaluated from these data. Entropies of transfer of a peptide backbone unit (CH2CONH) and peptide group (CONH) from water to aqueous ethanol solutions were derived from the enthalpy of transfer data and the free energies of transfer of glycine, alpha-alanine, beta-alanine and diglycine. The thermodynamic transfer functions are discussed in terms of "water structure" mediated solute-solute interactions. The observed trends in the thermodynamic transfer functions have also been utilized to rationalize the effect of alcohols on the conformational stability of proteins and polypeptides in aqueous solutions.

Variation of antimetabolite sensitivity with different carbon sources in Bacillus subtilis

The susceptibility of Bacillus subtilis to amino acid analogues was found to be markedly influenced by the carbon source used in the test media. Thialysine inhibited the bacterium with a greater number of carbon sources than the other two analogues tested. 5-Hydroxylysine was inhibitory with glycerol, lactose, D-xylose, L-arabinose and soluble starch while ethionine showed toxicity with lactose, D-xylose and L-arabinose. None of these analogues were toxic at the levels tested when D-galactose was used as carbon source. The bacterium was not susceptible to thialysine with glycerol, to 5-hydroxylysine with L-arabinose and to ethionine with lactose.

Partial molar heat capacity of the peptide group in aqueous solutions

Integral enthalpies of solution at very high dilution of sodium salts of N-acetyl amino acids, N-acetyl peptides, and N-benzoyl glycine have been measured in water at 298.15 and 308.15 K. Standard heat capacities of solution at 303.15 K have been derived from the enthalpy of solution data. The peptide backbone-unit (CH2CONH) contribution toward the limiting partial molal heat capacities derived from these experimental results is compared with those obtained from Cop2 of other model compounds, viz. oligopeptides, pyrrolidones, piperidones, diketopiperazine, and amides. Cop2 of the peptide backbone unit observed in the sodium slats of the N-substituted amino acids and peptides is also correlated with the structural details of the compounds and it is concluded that Cop2 contribution of the whole CH2CONH group, rather than that of CONH group, should be used for predicting the heat capacities of polypeptides and proteins in aqueous solution.

Comparative efficacy of drugs in bovine anaplasmosis

Calves experimentally infected with Anaplasma marginale were subjected to chemotherapeutic treatment in groups, each group receiving one drug only. Observations were made on clinical signs, haematological changes, parasitaemias and levels of antibodies as measured by the complement fixation test. The most effective treatment was with imidocarb; other drugs which were apparently effective were steclin, terramycin and aureomycin in that order, while chloroquin diphosphate and camoquin gave little indication of therapeutic value.

Deoxyribonucleic acid-mediated transformation of Spirillum lipoferum

The methodology for deoxyribonucleic acid-mediated transformation of Spirillum lipoferum to resistance to various antimicrobial agents is reported.

Surgical correction of senile entropion of the lower lid with fascia lata sling

A method of surgical correction of senile entropion of the lower lid with heterogenous fascia lata sling is described with no tissue loss and minimum of surgical trauma.

Scanning electron microscopy of the spines of the tunic of the ascidian, Boltenia ovifera

The presence of small spines on the exterior surface of the tunic of Boltenia ovifera, which contain axially oriented microfibrils of cellulose, was confirmed by scanning electron microscopy. These spines axe a continuous extension of the mass of the tissue without a recognizable discontinuity between them and the rest of the tunic. They show a trilobed form at their base after preparation for electron microscopy but this may be a result of desiccation. Tips of the spines are blunt and they, as well as the axial microfibrils which compose the shaft, are enclosed in a sheath which seems to be amorphous. On the surface of the tunic, the water-insoluble glycoprotein component is sparsely distributed. The distribution and morphology of these spines pose unusual problems for the mechanism of extracellular synthesis and deposition of cellulose microfibrils.

DEVELOPMENTAL STUDIES ON THE COENOCYTIC ALGA, CAULERPA SERTULARIOIDES

Thallus growth and development in the coenocyti alga Caulerpa sertularioides (Gmelin) Howe have been studied quantitatively. In unsupplemented seawater at 26 C and in a 12:12 hr light/dark cycle, new rhizomes formed near the old growing points on thalli transplanted from the ocean. Adjacent to the apices of new rhizomes, rhizoids were produced downward, regularly spaced and at a rate of about 1.5/day. Upright. shoots developed irregularly in acropetal succession behind the tips of either the parent or the new rhizomes, which arose as branches of the old. Rates of rhizome, rhizoid, and upright shoot elongation were 0.4, 0.81, and 0.54 cm/day, respectively. Thalli survived up to 2 months in unsupplemented seawater. Long-term growth was obtained by varying culture conditions. A substratum of sand, apparently rich in microorganisms, produced long-term thallus growth in seawater, and the form of development changed so that upright shoot formation was promoted and rhizome elongation halved. Similar effects were elicited by indole-3-acetic acid, 5 × 10(-5) , M in seawater and by sap expressed from C. racemosa or C. sertularioides and added to seawater at 2.5-10% by volume. The regulation of development in an algal coenocyte is discussed and analogies with regulation in multicellular plants are drawn.