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Biomedical subjects

R Joshi

Publications and source records attributed to R Joshi.

At least 55 records · Page 3Linked to original sources
PubMed1995

Comparative evaluation of modified m-FC and m-TEC media for membrane filter enumeration of Escherichia coli in water.

Two media used to detect fecal coliforms in water by membrane filtration, m-FC and m-TEC, were modified and supplemented with the chromogenic substrate 5-bromo-6-chloro-3-indoyl-beta-D-glucuronide (BCIG) and were compared for quantitative recovery of Escherichia coli. Student's t test of data from 181 water samples of sewage, rivers, lakes, and wells did not demonstrate any statistically significant differences (P = 0.05) in the enumeration of E. coli with these media. Target colonies were confirmed to be E. coli at rates of 98.6 and 97.3% by using FC-BCIG and TEC-BCIG media, respectively. Glucuronidase-negative isolates of E. coli were encountered at the same frequency (6.0%) on both media. This collaborative study demonstrated that either modified basal medium could be used successfully for detection of E. coli in various nontreated waters within 24 h.

Colony Count, Microbial↗
PubMed1995

Ovarian disorders of pregnancy.

Hormonal ovarian disorders are uncommon during pregnancy and present primarily as ovarian masses. The two most common conditions are luteomas and hyperreactio luteinalis. The most common clinical manifestation is maternal virilization, which occasionally affects the fetus also. Rarely, an acute abdomen can result from hemorrhage or torsion of the mass. Because most of the entities regress spontaneously following delivery, a conservative management approach that includes preserving the ovaries is warranted.

Female↗
PubMed1994

Structural and functional analysis of an Opaque-2-related gene from sorghum.

The Opaque-2 (O2) gene from maize encodes a transcriptional activator of the b-ZIP class. We have isolated and characterized a gene from sorghum, related in sequence to the O2 gene from maize. A single copy of the gene is present in sorghum. Both genomic and cDNA sequences of the O2-related sorghum gene were determined. The sequence is highly homologous to maize O2 both in the promoter and in the coding region. The most closely related sequences contain the b-ZIP domain with only 11 amino acid substitutions in a total of 122 residues. In transient expression assays, the sorghum O2-related coding sequence, expressed from a CaMV 35S promoter, activates expression from the maize b-32 promoter as effectively as that obtained with the maize O2 sequence.

Amino Acid Sequence↗
PubMed1994

Pregnancies after assisted fertilization for "extreme" male factor: report on three cases.

Three cases of extreme male factor infertility, not acceptable for conventional IVF, are presented. In the first case, only 30 sluggishly motile spermatozoa were obtained in two ejaculates but treatment with SUZI resulted in a viable singleton pregnancy. In the second case, a combination of microepididymal sperm aspiration, for vasal obstruction after failure of reversal, with intracytoplasmic sperm injection resulted in a viable singleton pregnancy. In the third case, the husband had a vasal reservoir for distal vasal blockage. Sperm from the reservoir with extremely low motility and high antisperm antibody were microinjected by intracytoplasmic sperm injection and this resulted in a triplet pregnancy.

Adult↗
PubMed1993

Pheochromocytoma manifested as noncardiogenic pulmonary edema.

We have reported the case of a woman who had repeated episodes of noncardiogenic pulmonary edema as the initial clinical manifestation of pheochromocytoma. She had no evidence of heart failure or paroxysmal blood pressure changes. In a review of the English-language literature, we found only five other cases in which pheochromocytoma was associated with noncardiogenic pulmonary edema. Our report emphasizes the need to consider pheochromocytoma in the differential diagnosis of noncardiogenic pulmonary edema. Awareness of this unusual clinical presentation will increase the likelihood of early diagnosis and surgical cure.

Adrenal Gland Neoplasms↗
PubMed1993

Tiapride versus metoclopramide: comparison after minor gynaecological surgery.

Tiapride (Tiapridal, Delagrange), a dopaminergic D2 receptor blocking agent having anxiolytic, sedative, antiemetic and analgesic properties was compared with metoclopramide and placebo in a randomized double-blind trial to determine its effects on post-operative nausea, vomiting, and sedation. The agents were given intravenously immediately before induction of anaesthesia to 75 women scheduled for minor elective gynaecological surgery. A standardized anaesthetic technique was used in all the patients. In the recovery room anti-emetic and sedative effects of tiapride and metoclopramide were similar and significantly better (P < 0.001) than placebo. In the ward at the end of 5 h anti-emetic (P < 0.05), and sedative (P < 0.01) effects of tiapride were significantly better than both metoclopramide and placebo.

Abortion, Incomplete↗
PubMed1992

The point mutation of hypoxanthine-guanine phosphoribosyltransferase (HPRTEdinburgh) and detection by allele-specific polymerase chain reaction.

The change in DNA responsible for partial hypoxanthine-guanine phosphoribosyltransferase (HPRT) deficiency in three brothers has been determined by polymerase chain amplification and sequencing. An A-to-G substitution at base 155 in exon 3 predicts a change in aspartic acid 52 to glycine. Allele-specific polymerase chain amplification verified the presence of the mutation in genomic DNA and provides a means of direct diagnostic assay.

Adolescent↗
PubMed1992

Synovial fluid stimulates the proliferation of rabbit ligament. Fibroblasts in vitro.

This study was designed to test the hypothesis that synovial fluid may be inhibitory to cell proliferation. The effects of bovine synovial fluid (SF) and hyaluronic acid (HA) on the proliferation of normal rabbit medial collateral ligament (MCL), anterior cruciate ligament (ACL), and MCL scar cells were therefore investigated. Cell lines established from rabbit tissues were plated, incubated, and allowed to attach before treatment with varying concentrations of SF, HA, and a balanced salt solution (BSS). The BSS group was added as a control to observe the effects of media dilution alone on cell proliferation. Cell numbers from each group were quantified at 24, 48, 72, and 96 hours. Results showed that for all cell types, cell proliferation during the log phase of growth was significantly stimulated by SF. Maximum stimulation occurred in 20% SF with stimulation decreasing at higher concentrations of SF. HA had virtually no effect on scar and ACL cells, and only a slight stimulatory effect on MCL cells. Media dilution had no effect on scar cells and began to inhibit cell proliferation of ACL and MCL cells only at high dilutions. These findings suggest that low concentrations of bovine SF stimulate proliferation of rabbit ligament and scar fibroblasts in vitro by a mechanism that appears not to involve HA. Even in high concentrations, SF was not inhibitory to proliferation. The implications of these findings to ligament healing and normal ligament physiology require further investigation.

Animals↗
PubMed1991

Adducin in erythrocyte precursor cells of rats and humans: expression and compartmentalization.

Adducin is a calmodulin-binding protein involved in the assembly of the erythrocyte membrane skeleton. To investigate the expression of adducin during human erythropoiesis, we performed immunofluorescence studies on smears of cultured human erythroblasts. Adducin immunoreactivity was found in the early stages of erythropoiesis. Proerythroblasts were the first erythroid precursor cells positive for adducin. The adducin signal was very similar to the signal of erythroid beta-spectrin in that both proteins lined the membrane of erythroid precursor cells. Cell fractionation experiments were performed to further analyze the intracellular distribution of adducin in erythroid cells. In erythroblasts, about 60% of total cellular adducin appeared in the Triton-soluble fraction. In reticulocytes, the Triton-soluble fraction decreased to 30% of total reticulocyte adducin. Erythrocytes had no detectable amount of adducin in the Triton-soluble pool. Instead, adducin was quantitatively bound to the Triton-insoluble erythrocyte cytoskeleton. Our results suggest that adducin is expressed early in the development of the erythrocyte membrane skeleton, whereas stable assembly onto the membrane skeleton does not occur before the final stages of mammalian erythropoiesis.

Animals↗
PubMed1991

Primary structure and domain organization of human alpha and beta adducin.

Adducin is a membrane-skeletal protein which is a candidate to promote assembly of a spectrin-actin network in erythrocytes and at sites of cell-cell contact in epithelial tissues. The complete sequence of both subunits of human adducin, alpha (737 amino acids), and beta (726 amino acids) has been deduced by analysis of the cDNAs. The two subunits have strikingly conserved amino acid sequences with 49% identity and 66% similarity, suggesting evolution by gene duplication. Each adducin subunit has three distinct domains: a 39-kD NH2-terminal globular protease-resistant domain, connected by a 9-kD domain to a 33-kD COOH-terminal protease-sensitive tail comprised almost entirely of hydrophilic amino acids. The tail is responsible for the high frictional ratio of adducin noted previously, and was visualized by EM. The head domains of both adducin subunits exhibit a limited sequence similarity with the NH2-terminal actin-binding motif present in members of the spectrin superfamily and actin gelation proteins. The COOH-termini of both subunits contain an identical, highly basic stretch of 22 amino acids with sequence similarity to the MARCKS protein. Predicted sites of phosphorylation by protein kinase C include the COOH-terminus and sites at the junction of the head and tail. Northern blot analysis of mRNA from rat tissues, K562 erythroleukemia cells and reticulocytes has shown that alpha adducin is expressed in all the tissues tested as a single message size of 4 kb. In contrast, beta adducin shows tissue specific variability in size of mRNA and level of expression. A striking divergence between alpha and beta mRNAs was noted in reticulocytes, where alpha adducin mRNA is present in at least 20-fold higher levels than that of beta adducin. The beta subunit thus is a candidate to perform a limiting role in assembly of functional adducin molecules.

Amino Acid Sequence↗
PubMed1990

Mapping the domain structure of human erythrocyte adducin.

Adducin is a 200-kDa heterodimeric protein associated with the erythrocyte membrane skeleton which binds to Ca2+/calmodulin, promotes binding of spectrin to actin, and is a substrate for protein kinases C and A. Adducin polypeptides can be structurally and functionally divided into two distinct regions. The amino-terminal 39-kDa domain of each subunit is more basic and resistant to proteases than the C-terminal 60-64-kDa domain, which is very sensitive to proteolytic degradation. Two-dimensional peptide map analysis revealed that the 39-kDa protease-resistant domains represent a portion of adducin which is highly conserved between the alpha and beta subunits whereas the protease-sensitive regions are different in each subunit. Comparison of the structural and functional properties of purified 39-kDa domains with intact adducin showed that the 39-kDa domains were not phosphorylated by protein kinases C or A and did not bind to Ca2+/calmodulin or interact with spectrin and actin. This suggests that the protease-sensitive domains may perform the various functions of adducin since these activities were all lacking from the protease-resistant domains. It is also possible that the conserved and variable domains are both required for one or more activities of adducin or that the 39-kDa domains play a role in maintaining the oligomeric state of adducin necessary for interaction of the variable domains with spectrin-actin complexes.

Blood Proteins↗
PubMed1990

Sulfate self-exchange and amino acid transport in calcium-loaded human erythrocytes.

To analyze the effects of Ca2(+)-mediated membrane protein changes on the membrane function, we have studied the SO4(2-) self-exchange and amino acid transport in human erythrocytes after loading them with Ca2+ with the help of ionophore A23187. The SO4(2-) self-exchange is inhibited by 20-30% by loading the erythrocytes with 25 microM to 0.5 mM Ca2+. The extent of this inhibition is almost doubled (50-60%) by increasing the Ca2+ loading concentration to 1.5 mM. This additional effect of 1.5 mM Ca2+ is not correlated with the Ca2(+)-induced ATP depletion or membrane protein degradation, but is caused by the transglutaminase-catalyzed membrane protein crosslinking. Like the SO4(2-) self-exchange, L-alanine and L-cysteine uptakes are also inhibited in Ca2(+)-loaded cells. However, no effect is observed on the L-lysine uptake under identical conditions. These results have been interpreted to suggest that the Ca2(+)-mediated effects on the SO4(2-) self-exchange and amino acid transport are caused perhaps by the Ca2(+)-induced structural rearrangement of the band 3 protein.

Adenosine Triphosphate↗
PubMed1990

Establishment and comparison of fibroblast cell lines from the medial collateral and anterior cruciate ligaments of the rabbit.

We have developed a procedure to explant fibroblasts from the anterior cruciate ligament (ACL) and the medical collateral ligament (MCL) of the rabbit knee, and have optimized conditions for maintaining them in culture. Maximal growth for both ACL and MCL cells was obtained with Dulbecco's modified Eagle's medium supplemented with 15% fetal bovine serum and 250 microM ascorbate. ACL and MCL fibroblasts displayed intrinsic differences in their responses to changes in culture parameters. Specifically, they displayed different growth responses when plated at different densities and responded to RPMI 1640 medium in very different ways. There were also biochemical differences between the cell types. Both cell types produced similar amounts of collagen in culture, but the ratio of type I to type III, the major collagen subtypes produced by these cells, were different. ACL fibroblasts produced 86.7% type I and 13.3% type III, and MCL fibroblasts produced 71.1% type I and 28.9% type III. In addition, total protein produced by ACL fibroblasts was higher than that produced by MCL cells. This confirms the suggestions of previous researchers that such differences might exist.

Animals↗