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Biomedical subjects

B Verma

Publications and source records attributed to B Verma.

18 recordsLinked to original sources
PubMed2001

A computer-aided diagnosis system for digital mammograms based on fuzzy-neural and feature extraction techniques.

An intelligent computer-aided diagnosis system can be very helpful for radiologist in detecting and diagnosing microcalcifications' patterns earlier and faster than typical screening programs. In this paper, we present a system based on fuzzy-neural and feature extraction techniques for detecting and diagnosing microcalcifications' patterns in digital mammograms. We have investigated and analyzed a number of feature extraction techniques and found that a combination of three features, such as entropy, standard deviation, and number of pixels, is the best combination to distinguish a benign microcalcification pattern from one that is malignant. A fuzzy technique in conjunction with three features was used to detect a microcalcification pattern and a neural network to classify it into benign/malignant. The system was developed on a Windows platform. It is an easy to use intelligent system that gives the user options to diagnose, detect, enlarge, zoom, and measure distances of areas in digital mammograms.

Breast Neoplasms↗
PubMed1999

Intraosseous access using butterfly needle.

Butterfly needle (18 G) was used for intraosseous administration of fluids and drugs in 22 children with shock. All except one patient could be stabilized successfully. Fifteen children had severe dehydration because of diarrhoea. The intraosseous route needs to be popularized as an option for rehydration in areas, where diarrhoeal dehydration continues to be an important cause of child mortality.

Child, Preschool↗
PubMed1998

Topical pefloxacin in bacterial keratitis.

PROBLEM: To evaluate the clinical efficacy and safety of topical pefloxacin 0.3% drops as the sole antibiotic used to treat culture positive bacterial corneal ulcers. METHODS: Forty two consecutive Gram's smear-positive cases of bacterial corneal ulcers were enrolled for this prospective open labelled clinical trial. All patients underwent a complete clinical and microbiological work up and were put on topical 0.3% pefloxacin drops with supportive cycloplegic, vitamins and antiglaucoma therapy. Of 42 cases, 4 cases of mycotic keratitis and 6 culture negative cases were excluded from the study. RESULTS: Positive microbiologic cultures were obtained in 84.2% (32 of 38) cases. Staphylococcus aureus (14/32; 43.7%) and coagulase negative Staphylococci (12/32; 37.5%) were the two most common organisms isolated. Resolution of the corneal ulcer was achieved in 31 out of 32 cases (96.9%) with a mean duration of 9.3+/-5.3 days (range 3-21 days). Best corrected visual acuity of 20/200 or better was achieved in 65.6% of cases at 4 weeks post resolution. Corneal deposits were observed in one case which disappeared 8 days following discontinuation of therapy. CONCLUSIONS: Topical pefloxacin is effective as a single antibiotic agent for the treatment of bacterial keratitis.

Adolescent↗
PubMed1998

Study on serum sperm agglutination in cases of unexplained infertility.

In our study we investigated 100 couples of unexplained infertility in order to detect the presence of anti-spermatozoal antibodies. Both auto-immunity and Iso-immunity have been found responsible in 12.5% of couples of primary infertility & 10% of couples of secondary infertility. As many as, 21% of cases of unexplained infertility were attributed to presence of antibodies in sera of infertile couples. Here, we highlight the importance of anti-spermatozoal antibodies testing in the first instance itself in cases of unexplained infertility.

Agglutination Tests↗
PubMed1997

Recognition of rotating images using an automatic feature extraction technique and neural networks.

This paper presents a new automatic feature extraction technique and a neural network based classification method for recognition of rotating images. The image processing technique extracts global features of an image and converts a large size image into a one-dimensional small vector. A special advantage of the proposed technique is that the extracted features are the same even if the original image is rotated with rotation angles from 5 to 355 or rotated and a little bit distorted. The proposed technique is based on simple co-ordinate geometry, fuzzy sets and neural networks. The proposed approach is very easy in implementation and it has been developed in C++ on a Sun workstation. The experimental results have demonstrated that the proposed approach performs successfully on a variety of small as well as large scale rotated and distorted images.

Algorithms↗
PubMed1994

Acute ethanol consumption synergizes with trauma to increase monocyte tumor necrosis factor alpha production late postinjury.

The hypothesis that acute ethanol uptake plus trauma can synergize to increase immunosuppression was tested. We found that, unlike non-alcohol-exposed patients, patients with acute alcohol use prior to trauma have a transient decrease in monocyte tumor necrosis factor alpha (TNF alpha) production during the very early postinjury (0-3 days) period. However, TNF alpha production by these alcohol-exposed patients' monocytes (M0) became hyperelevated late postinjury (> 9 days). Consequently, these massively elevated M0 TNF alpha levels can contribute to posttrauma immunosuppression after acute alcohol use. We also demonstrate that normal monocyte activation with the superantigen, Staphylococcus enterotoxin B (SEB), results in a preferential induction of cell-associated M0 TNF alpha production, described as characteristic of immunosuppressed trauma patients. Acute in vitro ethanol treatment down-regulated the elevated TNF alpha production by trauma patients' M0 after either SEB, muramyl-dipeptide (MDP), interferon-gamma plus MDP, or lipopolysaccharide (LPS) stimulation. Both SEB- and LPS-induced TNF alpha mRNA induction was inhibited by acute alcohol treatment in normal M0, indicating that ethanol can regulate cytokine gene expression. An additional immunosuppressive effect of acute ethanol's stimulation was suggested by its induction of elevated transforming growth factor beta production in trauma patients' activated M0.

Adult↗
PubMed1994

Regulatory potential of ethanol and retinoic acid on human monocyte functions.

Retinoic acid (RA), a metabolic product of vitamin A, has been shown to affect a variety of immune functions, including monocytes. Monocyte functions and mediator production are also modulated by ethanol exposure. This study demonstrates that therapeutic doses of RA (0.1-10 microM) significantly increase transforming growth factor-beta (TGF beta) production both in THP-1, human myelomonocytic cells, and in human peripheral blood monocytes. We have previously reported TGF beta induction by ethanol in human M theta. Combination of RA stimulation with acute in vitro ethanol treatment, however, resulted in significantly lower M theta TGF beta production than TGF beta levels induced by RA alone (p < 0.003). Down-regulation of M theta TGF beta production by ethanol was tested at the concentration range of 25-150 mM and occurred both at high and low RA concentrations (10-0.1 microM). In contrast to its inhibitory effect on RA-induced M theta TGF beta production, ethanol augmented TGF beta production induced by muramyl dipeptide (20 micrograms/ml), suggesting that ethanol can either up- or down-regulate M theta TGF beta production, depending on the costimulatory factors. RA also induced a moderate increase in M theta tumor necrosis factor-alpha (TNF alpha) production, which was down-regulated by ethanol both at the level of secreted and cell-associated TNF alpha. In addition to regulation of cytokine production, both RA and ethanol decreased expression of CD4 on THP-1 cells. The degree of inhibition of CD4 expression by RA was more significant than by ethanol, but RA-induced decrease in CD4 expression was not significantly affected by the combined stimulation with ethanol.(ABSTRACT TRUNCATED AT 250 WORDS)

CD4 Antigens↗
PubMed1993

Selective inhibition of antigen-specific T lymphocyte proliferation by acute ethanol exposure: the role of impaired monocyte antigen presentation capacity and mediator production.

Ethanol consumption is associated with impaired immunity. Our data demonstrate that even a single dose of a biologically relevant concentration (25-150 mM) of ethanol can down-regulate antigen-specific T lymphocyte proliferation. In contrast, ethanol augmented mitogen-induced T cell proliferation, suggesting that its inhibitory effect on antigen-specific T cell proliferation was due to its effects on monocytes (m phi s) rather than on T cells. The immunodepressive effects of ethanol on m phi antigen-presenting cell (APC) capacity were manifested whether alcohol treatment was limited to the antigen uptake-processing period only or was present during the entire period of antigen presentation. These inhibitory effects of ethanol were also evident on both the high-antigen-presenting, Fc gamma RI-negative (-31 +/- 17%), and low-antigen-presenting, Fc gamma RI-positive (-42 +/- 15%) m phi subpopulations. Further analysis demonstrated that ethanol inhibits the production of interleukin-1 beta (IL-1 beta) and induces transforming growth factor beta (TGF-beta) and prostaglandin E2 (PGE2), monocyte-derived mediators that can affect T cell proliferation. Ethanol resulted in a dose-dependent down-regulation of secreted and cell-associated IL-1 beta protein as well as IL-1 beta mRNA levels induced by adherence or bacterial stimulation. The causal relationship between decreased m phi IL-1 beta production, elevated TGF-beta levels, and the decreased m phi APC capacity was further substantiated when exogenous IL-1 beta protein or anti-TGF-beta neutralizing antibody prevented the down-regulatory effect of ethanol on antigen-specific T cell proliferation. Utilizing a cyclooxygenase inhibitor, we also demonstrated that the ethanol-induced decrease in m phi APCs is not mediated by enhanced PGE2 production.

Adult↗
PubMed1988

Partial purification and characterization of phosphatidylinositol kinase from bovine brain.

Purification of Phosphatidylinositol (PI) kinase was attempted from bovine brain. A seven step purification protocol increased the specific activity 100 x but attempts at further purification were unsuccessful. Labeling of the partially purified PI kinase with the ATP analog fluorosulfonylbenzoyl adenosine reproducibly identified three bands on polyacrylamide gel electrophoresis of 76 K, 45 K, and 29 K, one of which likely represents PI kinase. Kinetic studies showed a Km of 17 microM for ATP, 0.02 mg/ml for PI and a Vm of 1830 pmol/min/mg protein for ATP and 820 pmol/min/mg protein for PI.

1-Phosphatidylinositol 4-Kinase↗
PubMed1975

Conformational and functional studies of chemically modified cytochrome c: nitrated and iodinated cytochromes c.

The purification of iodinated (E. B. McGowan and E. Stellwagen (1970), Biochemistry 9, 3074) and of nitrated (M. Sokolovsky et al. (1970), Biochemistry 9, 5113) cytochromes c resulted in the recovery from the former preparation of diiododityrosyl-cytochrome c (DIDT-) with modification of Tyr-67 and Tyr-74, and, from the latter, a mononitromonotyrosyl-cytochrome c (MNMT-), with modification of Tyr-67, and mononitrodityrosyl-cytochrome c (MNDT-), with the added modification of Tyr-48. The three purified preparations were conformationally characterized using pH-spectroscopy, circular dichroism, thermal denaturation, reducibility with ascorbate, autoxidation with molecular oxygen, and binding with CO. These results are related to the two aspects of biological function, reducibility, measured by NADH-cytochrome c reductase, and oxidizability, with cytochrome c oxidase, as well as to structure-function relationships in the protein. MNMT-cytochrome c was found to be, structurally and conformationally, a single isomer, reducible with ascorbate, with a small, but definite affinity for both oxidation with molecular oxygen and binding of CO. Conformationally, in both valence states of the metal atom, it represents a molecular form with native-like conformation with small but definite perturbations in the immediate vicinity of the heme group, reflected by the destabilization of the Met-80-S-Fe linkage. MNMT-ferricytochrome c exhibits a pK of 6.2 for the transformation of the low-spin, native-like spectral form II containing the 695-nm band to form lacking lacking the 695-nm band. The isomerization at pK = 6.2, when analyzed in terms of the isomerization of the native protein with a pK of 9.2 and the nature of the group involved, indicates that Tyr-67 is not involved in the isomerization of the modified preparation, and possibly not in the native protein as well. In terms of biological function, the partial derangement of redecibility (24%) and the unaltered oxidizability point to the functional significance of Tyr-67, and provide another example of selectivity between the two aspects of physiological functional function, in agreement with the two-function, two-path operational model of the protein. The MNDT- and DIDT-ferricytochromes c exhibited physicochemical properties indicative of gross derangement of both the conformation of the protein as well as of the coordination configuration of the metal atom. The complete inability to accept an electron from NADH-cytochrome c reductase in both cases, and the retention of 50% of the oxidizability property of DIDT-cytochrome c, were interpreted to be the result of conformational derangement, rather than the added modification of Tyr-48 or of Tyr-74.

Amino Acids↗