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Biomedical subjects

K B Rao

Publications and source records attributed to K B Rao.

At least 19 recordsLinked to original sources
PubMed2005

Adrenomyeloneuropathy.

Adrenomyeloneuropathy is a rare X-linked inherited disorder of peroxisomes characterized by the accumulation of very long chain fatty acids (VLCFA) in the central and peripheral nervous system, adrenal glands and testis leading to the dysfunction of these organs and systems. The phenotypic expression is highly variable, childhood cerebral adrenoleukodystrophy and adrenomyeloneuropathy being the main variants. Here we report a case of adrenomyeloneuropathy presenting initially as Addison's disease, which remained undiagnosed for many years with many rare features. We could not locate any other publication on this subject in the indexed journals of literature published from India.

Adolescent↗
PubMed1999

Kinetics of inclusion body production in batch and high cell density fed-batch culture of Escherichia coli expressing ovine growth hormone.

A process for maximizing the volumetric productivity of recombinant ovine growth hormone (r-oGH) expressed in Escherichia coli during high cell density fermentation process has been devised. Kinetics of r-oGH expression as inclusion bodies and its effect on specific growth rates of E. coli cells were monitored during batch fermentation process. It was observed that during r-oGH expression in E. coli, the specific growth rate of the culture became an intrinsic property of the cells which reduced in a programmed manner upon induction. Nutrient feeding during protein expression phase of the fed-batch process was designed according to the reduction in specific growth rate of the culture. By feeding yeast extract along with glucose during fed-batch operation, high cell growth with very little accumulation of acetic acid was observed. Use of yeast extract helped in maintaining high specific cellular protein yield which resulted in high volumetric productivity of r-oGH. In 16 h of fed-batch fermentation, 3.2 g l-1 of r-oGH were produced at a cell OD of 124. This is the highest concentration of r-oGH reported to date using E. coli expression system. The volumetric productivity of r-oGH was 0.2 g l-1 h-1, which is also the highest value reported for any therapeutic protein using IPTG inducible expression system in a single stage fed-batch process.

Animals↗
PubMed1999

Expression of growth factor ligand and receptor genes in preimplantation stage water buffalo (Bubalus bubalis) embryos and oviduct epithelial cells.

The temporal pattern of expression of genes for several growth factor ligands and receptors was examined in preimplantation water buffalo embryos and oviduct epithelial cells using RT-PCR. The identity of the resulting PCR products was confirmed by their expected size, restriction analysis, Southern blot hybridization and nucleotide sequence analysis. Preimplantation stage embryos from the one-cell to the blastocyst stage were derived after maturation, fertilization and culture of oocytes in vitro. Expression of members of the insulin-like growth factor (IGF) family was observed predominantly in preimplantation stage embryos and oviduct epithelial cells. Similarly, transcripts encoding insulin and IGF-I receptors were detected at each stage of embryonic development. The mRNA transcript of the IGF-I receptor was not detected in oviduct epithelial cells, but a prominent band corresponding to the insulin receptor was observed. Insulin and IGF-II mRNA were expressed as maternal transcripts that were not detected at the two- to four-cell stage but were present as zygotic transcripts at the eight-cell stage. Transcripts encoding IGF-I were detected in oviduct epithelial cells, but were not observed in any of the preimplantation stage embryos. Transforming growth factor (TGF) alpha and beta and epidermal growth factor mRNA transcripts were not detected in any of the preimplantation stage embryos. These results indicate that IGF-I acts via a paracrine mechanism to promote growth and development of preimplantation water buffalo embryos. Similarly, IGF-II appears to act through a heterologous autocrine mechanism via the IGF-I or the insulin receptor. Furthermore, the presence of TGF-alpha in oviduct epithelial cells indicates that it may have a critical role during development.

Amino Acid Sequence↗
PubMed1998

Effect of insulin-like growth factor I and its interaction with gonadotropins on in vitro maturation and embryonic development, cell proliferation, and biosynthetic activity of cumulus-oocyte complexes and granulosa cells in buffalo.

In this study we have examined the effect of insulin like growth factor I (IGF-I) and its interaction with gonadotropins in the presence or absence of granulosa cell coculture on in vitro oocyte maturation (IVM) and their subsequent embryonic development in buffalo. We also have examined the role of IGF-I alone or in combination with gonadotropins on DNA synthesis, steroidogenesis, and protein synthesis of cumulus-oocytes complexes (COCs) and granulosa cells. Results showed that IGF-I stimulates oocytes maturation in a dose-dependent manner, with maximal effect at a dose of 100 ng/ml (P < 0.05). IGF-I showed positive interaction with follicle-stimulating hormone (FSH) in the presence or absence of granulosa cells on meiotic maturation and synergistically enhanced DNA synthesis, protein synthesis, and steroidogenesis in the presence of granulosa cells. This synergistic effect is mainly caused by the increase of IGF-I receptors in granulosa cells by FSH, as evident by [125I]IGF-I binding study. Luteinizing hormone (LH), however, was found to suppress IGF-I and IGF-I + FSH stimulated oocyte maturation. Addition of LH to cultures containing IGF-I + FSH, on the contrary, caused a significant increase in oocyte maturation when cocultured with granulosa cells. Addition of IGF-I during IVM significantly improve cleavage and blastocyst development rate over the control group. However, there was no cumulative effect when IGF-I and gonadotropins were present together. Addition of granulosa cells during IVM, however, enhanced blastocyst development in the IGF-I + FSH and IGF-I + FSH + LH groups. Our results demonstrated that IGF-I is a major follicular factor responsible for stimulating oocyte maturation in the buffalo. Interaction between IGF-I and FSH suggests that they seem to act synergistically as an autocrine and paracrine regulator of granulosa cells and therefore together promote mitosis, steroidogenesis, and protein synthesis.

Animals↗
PubMed1998

Randomly amplified polymorphic DNA (RAPD) for evaluating genetic relationships among varieties of guinea fowl.

The present study investigated the use of randomly amplified polymorphic DNA (RAPD) in estimating the intra and inter varietal genetic variation in three varieties of guinea fowl (Lavender, Pearl and White). The estimates, measured as band sharing were high for within population (0.946-0.971) and between population (0.990-0.999) genetic similarity. The respective estimates were 0.898-0.929 and 0.923-0.928 when estimated as frequency of occurrence of bands. The results indicated a very low level of intra and inter varietal genetic variation in these guinea fowl varieties, which in turn suggested the low level of genetic variation in these populations. The possible reasons for this high genetic similarity has been discussed.

Animals↗
PubMed1998

Rapid sexing of bovine preimplantation embryos using polymerase chain reaction: production of calves with predetermined sex under field conditions.

Two to four blastomere size biopsies were obtained from each 6-day-old embryo of zebu and crossbred cattle for sex determination. The sex of the embryos was determined with a set of bovine Y-chromosome specific primer pairs by using polymerase chain reaction. Thirty two biopsied embryos after their sex was determined, when transferred fresh to synchronized recipients, resulted in 56.2% pregnancy rate. Sixteen healthy calves were born at full term, while 2 heifers aborted at mid-term from fresh embryo transfer. Simultaneously, 44 biopsied embryos which were kept frozen, were thawed at a later date and transferred to the previously synchronized recipients, thereby leading to 24 pregnancies (54.5%). Twenty-three healthy calves were born at full term, while 1 heifer aborted at mid-term from frozen-thawed embryo transfer. The pregnancy rates from both fresh and frozen-thawed biopsied embryos were comparable with that of controls (P > 0.05). Except for a single misidentification of a male calf as a female by our PCR assay (2.6%), the phenotypic sex of all the live born calves as well as the aborted fetuses was correctly matched with the PCR detection.

Animals↗
PubMed1996

Detection of species-specific genetic markers in farm animals through random amplified polymorphic DNA (RAPD).

The potential use of random amplified polymorphic DNA (RAPD) was evaluated as a source of development of alternative genetic markers for studying variation in buffalo (Bubalus bubalis) and other related species of the Artiodactyla family Bovidae, in order to ascertain genetic relationships and diversities. Fourteen arbitrary primers were used to amplify DNA fragments in four species such as Indian Zebu cattle (Bos indicus), buffalo (Bubalus bubalis), sheep (Ovis aries) and goat (Capra hircus). Clear and distinct RAPD patterns with a higher level of polymorphism was detected between species, while fewer polymorphisms were found within the species. Species were subsequently scored for presence or absence of RAPD fragments and Jaccard's similarity coefficients were calculated to quantify the genetic divergence among the species. Wagner parsimony analysis of the RAPD data for 542 markers resulted in one most parsimonious tree which revealed very low similarity among the four species analysed.

Animals↗
PubMed1995

Assessment of amplicons in the DNA from boiled tissue by PCR and AP-PCR amplification.

Polymerase chain reaction (PCR) is a technique sensitive enough to amplify small DNA fragments a billion-fold. The generation of amplicons either by PCR with a set of oligo primers or by arbitrarily primed AP-PCR with a single oligonucleotide primer is based on the availability of intact template and priming sites. With these approaches, it is possible to generate specific and random amplicons to assess the extent of damage to DNA caused by any of the physical, chemical, or environmental factors. We report the amplification of sex chromosome and autosome specific loci in the buffalo (Bubalus bubalis) genome by symmetrical and AP-PCR performed on DNA samples isolated from the muscle tissues that were boiled (treated) for different lengths of time. No difference was noticed in the amplification profile of DNA cooked for various lengths of time. However, after HinfI treatment, AP-PCR amplification of these DNAs revealed more bands on agarose gel than unrestricted samples. The successful amplification of the DNA samples isolated from the boiled tissues is attributed to the intactness of the amplicons. This suggests that despite storage for more than a year and subsequent heat treatment to the muscle tissues, the DNA remains a good substrate for PCR and AP-PCR amplification. Relevance of this work in the context of DNA probe technology is discussed.

Animals↗
PubMed1993

Sex determination of in vitro developed buffalo (Bubalus bubalis) embryos by DNA amplification.

This study was conducted to determine the sex of buffalo embryos produced in vitro by amplifying male specific DNA sequences using the polymerase chain reaction (PCR). This method uses three different pairs of bovine Y-chromosome specific primers and a pair of bovine satellite specific primers. Buffalo in vitro fertilized embryos at the 4-cell to blastocyst stage were collected at days 3, 4, 6, and 8 postinsemination, and the sex of each embryo was determined using all three different Y-chromosome specific primers. The bovine satellite sequence specific primers recognize similar sequences in buffalo and are amplified both in males and in females. Similarly, Y-chromosome specific primers amplify the similar Y-chromosome specific sequences in male embryos of buffalo. Upon examining genomic DNA from lymphocytes of adult males and females, and embryos, the results demonstrate the feasibility of embryo sexing in buffaloes. Furthermore, sex determination by PCR was found to be a rapid and accurate method.

Animals↗
PubMed1992

Cloning and nucleotide sequencing of sheep growth hormone cDNA.

cDNA was prepared from the mRNA isolated from sheep anterior pituitary glands. On cloning cDNA in E. coli, a clone coding full sequence of sheep pre-growth hormone was determined. The sequence for the sheep growth hormone (GH) is in agreement with the amino acid sequence of the protein determined previously except for the asparagine residue at position 99 rather than aspartic acid and the arginine residue at position 146 in place of threonine. The cDNA sequence presented is also in accordance with the genomic sequence for the sheep GH gene that has been reported.

Amino Acid Sequence↗
PubMed1992

Sex determination in sheep and goats using bovine Y-chromosome specific primers via polymerase chain reaction: potential for embryo sexing.

A simple and novel method, using polymerase chain reaction (PCR) has been standardized for accurate sex determination in sheep and goats. The assay utilizes a pair of bovine Y-chromosome specific primers and the genomic DNA isolated from blood samples of adult male and female sheep and goats. The primers recognize and amplify the Y-chromosome specific sequences in male goats and sheep. The assay is accurate, reliable and rapid.

Animal Husbandry↗
PubMed1975

Maternal mortality in a teaching hospital in southern India. A 13-year study.

During the 13 years 1960-1972, in a teaching hospital that serves a predominantly rural and semiurban population in southern India, there were 74,384 deliveries and 1245 maternal deaths, a maternal mortality rate of 16.7 per 1000 births. Direct obstetric factors caused 854 (65.5%) of these deaths. The leading indirect or associated causes of maternal deaths were anemia, cerebrovascular accidents, and infectious hepatitis. During the past 13 years, monthly maternal mortality meetings have helped to reduce the incidence of avoidable factors in maternal deaths among patients from the city but not among those brought from the surrounding countryside. The important causes of maternal deaths in this developing country, and their prevention, are individually discussed.

Abortion, Illegal↗