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Biomedical subjects

J R Rao

Publications and source records attributed to J R Rao.

At least 37 records · Page 2Linked to original sources
PubMed1997

Comparison of indirect immunofluorescence (IIF) and enzyme-linked immunosorbent assay (ELISA) in detecting Babesia bigemina infection in cattle.

An indirect immunofluorescence test (IIF) and an enzyme-linked immuno-sorbent assay (ELISA) were standardised to investigate the prevalence of bovine babesiosis caused by Babesia bigemina in experimentally and naturally infected bovids. Both IIF and ELISA detected antibodies to B. bigemina 7 days after experimental infection with 87.5% and 100% sensitivity, respectively. The IIF results indicated that a titre greater than 1:64 was a reliable indicator of B. bigemina infection. Serological study of 214 serum samples collected from Boophilus microplus infested cattle from the State of Orissa revealed 33.6% overall seroreactivity by ELISA, whereas IIF recorded 9.4%. Both IIF and ELISA showed some degree of cross-reactivity between Indian (Izatnagar) and Mexican strains of B. bigemina.

Animals↗
PubMed1996

Effect of Mycobacterium phlei on the development of immunity to Babesia bigemina.

The immunomodulatory role of Mycobacterium phlei against intracellular blood protozoan Babesia bigemina was demonstrated following experimental immunisation and challenge in bovine calves. A lysate of erythrocytes infected (6 x 10(9)) with B. bigemina was used as a source of dead antigen either with Freund's complete adjuvant (FCA) or with a trypsinised culture of M. phlei as a non-specific immunomodulation (NSI) agent with appropriate controls. Following virulent challenge with B. bigemina infected erythrocytes (1 x 10(7)), the NSI printed calves showed 100% protection, while the dead antigen alone with FCA afforded 75% protection. The protective status of the immunising regimes was studied by clinicopathological parameters and assessment of humoral and cell-mediated immune responses. The role of babesial dead antigen and the effects of M. phlei on the development of immunity to B. bigemina is discussed.

Animals↗
PubMed1995

Influence of dietary aflatoxin on Eimeria uzura infection in Japanese quail (Coturnix coturnix japonica).

A study was conducted to assess the influence of dietary aflatoxin on Eimeria uzura in Japanese quail (Coturnix coturnix japonica). Quail receiving 1 part per million (ppm) of dietary aflatoxin B1 and inoculated with 10(5) sporulated oocysts of E. uzura gained significantly less weight than chicks receiving either aflatoxin or coccidia alone. Increased morbidity, mortality and decreased efficiency of feed utilization were also evident. The combination of E. uzura infection and aflatoxicosis resulted in reduction in packed cell volume (PCV) and haemoglobin (Hb). The combination of E. uzura infection and aflatoxicosis in Japanese quail may influence the course of coccidial infection due to the additive effects of aflatoxin.

Aflatoxin B1↗
PubMed1994

Rhizobia catabolize nod gene-inducing flavonoids via C-ring fission mechanisms.

Gas chromatographic and mass spectrometric analyses of derivatized culture medium extracts were used to identify the products of flavonoid metabolism by rhizobia. A number of Rhizobium species and biovars degraded their nod gene-inducing flavonoids by mechanisms which originated in a cleavage of the C-ring of the molecule and which yielded conserved A- and B-ring products among the metabolites. In contrast, Pseudomonas putida degraded quercetin via an initial fission in its A-ring, and Agrobacterium tumefaciens displayed a nonspecific mode of flavonoid degradation which yielded no conserved A- or B-ring products. When incubated with rhizobia, flavonoids with OH substitutions at the 5 and 7 positions yielded phloroglucinol as the conserved A-ring product, and those with a single OH substitution at the 7 position yielded resorcinol. A wider range of structures was found among the B-ring derivatives, including p-coumaric, p-hydroxybenzoic, protocatechuic, phenylacetic, and caffeic acids. The isoflavonoids genistein and daidzein were also degraded via C-ring fission by Rhizobium fredii and Rhizobium sp. strain NGR234, respectively. Partially characterized aromatic metabolites with potential nod gene-inducing activity were detected among the products of naringenin degradation by Rhizobium leguminosarum bv. viciae. The initial structural modification of nod gene-inducing flavonoids by rhizobia can generate chalcones, whose open C-ring system may have implications for the binding of inducers to the nodD gene product.

Agrobacterium tumefaciens↗
PubMed1992

Localized Changes in Flavonoid Biosynthesis in Roots of Lotus pedunculatus after Infection by Rhizobium loti.

Two-dimensional paper chromatography in four solvent systems, high-sensitivity spray reagents, and UV absorption spectroscopy were used to separate and characterize flavonoids and isoflavonoids in roots and root nodules of 20-d-old Lotus pedunculatus Cav. Seedlings were grown either under sterile conditions or after inoculation with Fix(+) or Fix(-) strains of Rhizobium loti. Flavonoids rather than isoflavonoids predominated in all tissues. Flavonoid profiles in sterile and denodulated root tissues were remarkably similar, both qualitatively and quantitatively. At least 14 partially purified flavonoid aglycones and conjugates were found in root extracts; denodulated root tissues contained no compounds that were not also present in sterile roots. Fix(+) rhizobia were responsible for major postinfection shifts in plant flavonoid biosynthesis at the sites of nodule morphogenesis. Polymeric flavolans were absent from Fix(+) nodules but present in all root tissues and in Fix(-) nodules. Catechin was detected only in Fix(+) nodules.

Journal Article↗
PubMed1990

Interaction between Eimeria uzura infection and aflatoxicosis in Japanese quail (Coturnix coturnix japonica).

The clinical signs and gross lesions caused by Eimeria uzura (10(5) oocysts) in Japanese quail (Coturnix coturnix japonica) exhibited little or no influence in the face of intercurrent dietary aflatoxicosis (1 p.p.m. of aflatoxin B1 from Day 0 to 55). Similarly, no significant differences in the mucosal morphology of the intestine were evident histologically between the two groups of Japanese quail. The nervous signs of ataxia, leg weakness, incoordination of movement, torticollis and terminal opisthotonos were toxin-induced manifestations. In the aflatoxic quail, hypoplastic changes and selective depletion of lymphocytes were more prominent in the bursa of fabricius. Increased relative mean weights of liver, kidney, spleen, crop, proventriculus and gizzard were observed in birds due to aflatoxin sensitivity. The combination of E. uzura infection and aflatoxicosis in Japanese quail may cause significant weight loss, and increased oocyst production and reproductive potential.

Aflatoxin B1↗
PubMed1981

Chronic threshold of stimulating electrodes: comparison of activated vitreous carbon with conventional platinum-iridium electrodes in animal tests.

Electrodes made of vitreous carbon are inert, corrosion-resistant, inactive to electrocatalytic reactions and are especially biocompatible. Upon activation, they attain a capacitance of 20 to 40 mF and become "non-polarizable". Therefore, they should be particularly suitable as stimulating and sensing electrodes for cardiac pacemakers. The connective tissue layer that develops around the electrode because of the foreign-body reaction is less than 100 micron thick. The threshold rise, through lower than that of conventional Pt-Ir or ELGILOY electrodes, cannot be attributed exclusively to the connective tissue layer that is formed. Under favourable conditions, the threshold in animal experiments remains below 525 mV. Blood-spaces adjoining the electrodes are found at higher chronic threshold values.

Animals↗
PubMed1978

Electrochemical behavior of amino acids and their influence on the anodic oxidation of glucose in neutral media.

Body fluids contain a large number of amino acids along with glucose. Therefore, the electrochemical behavior of amino acids should be considered in studying the anodic oxidation reaction of glucose for biological applications. Potential-sweep and steady-state measurements with different platinum electrodes under neutral conditions have shown that the oxidation of amino acids is basically possible. However, their presence, especially as a mixture, has a remarkable influence on the glucose oxidation and the anodic reaction is strongly inhibited. With respect to the degree of inhibition, they can be classified into two groups. The inhibiting effect is particularly drastic in the case of basic and unsaturated amino acids as well as the ones containing sulphur because of their strong absorption at the electrode surface. The glucose currents are inhibited by about 90% under steady-state. In addition to the direct electrochemical inhibition, the following bacterial decomposition of amino acids is probably also responsible for the drastic effect. However, about 10% of the glucose currents still remain measurable indicating that glucose is detectable at physiological concentrations even under extremly unfavorable conditions. This result is of basic importance in operating a biofuel cell or in measuring glucose concentrations.

Amino Acids↗
PubMed1976

Animal experiments with biogalvanic and biofuel cells.

Animal experiments with biogalvanic cells have demonstrated that an average power of 80 muW can be derived continously for at least 2 years. There is a further scope to stabilize the power at 100 muW for considerable longer periods so that the chances of cardiac pacing with biogalvanic power have become bright. However, large scale efforts are necessary in in establishing the statistical reliability and the secured performance which are expensive and time consuming. Animal experiments with biofuel cells are still in preliminary stages. We derived a continous power of 40 muW (4MUW/cm2) at 575 mV over 150 days so far. This is the longest recorded period with such a high power density. The main problem in deriving higher power over longer period is to properly encapsulate the cell with materials which are hydrophilic and essentially biocompatible.

Animals↗