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Biomedical subjects

M Pathak

Publications and source records attributed to M Pathak.

14 recordsLinked to original sources
PubMed2001

Role of myocytes in myocardial collagen production.

Excessive collagen deposition may cause abnormal stiffness of the heart during hypertrophy and heart failure. The potent vasoconstrictor angiotensin II seems, via an unknown mechanism, to stimulate collagen production. This study describes the in vitro and ex vivo effects of [Sar(1)]Ang II on collagen production by fibroblasts in culture and in beating, nonworking heart preparations. The effects of [Sar(1)]Ang II on isolated rat hearts or rat heart fibroblasts were determined by quantifying transcript levels of collagen phenotypes I and III through videodensitometry after Northern blot analysis with specific cDNA probes (collagen [P alpha( 2)r(2)] rat alpha( 2)[I] probe for type I and human skin fibroblast alpha(1)[III] probe for type III). When [Sar(1)]Ang II was added in vitro to neonatal or adult 28-week-old Wistar-Kyoto rat heart fibroblasts, questionable stimulation in the mRNAs of types I and III occurred. In contrast, when 10(-8) mol/L [Sar(1)]Ang II was added to beating, nonworking Wistar-Kyoto rat heart preparation ex vivo, a 1.5- to 2.5-fold stimulation of collagen mRNAs of phenotypes I and III was observed. When neonatal fibroblasts were cocultured with neonatal myocytes in vitro, with 10(-10) mol/L [Sar(1)]Ang II added, there was no stimulation of either phenotype. However, significant stimulation of both collagen transcripts was recorded when 10(-10) mol/L [Sar(1)]Ang II was added to adult fibroblasts cocultured with either neonatal or adult myocytes. Our data suggest that factors produced by myocytes are necessary for upregulation of collagen genes in vitro and demonstrate that fibroblast-myocyte cross-talk is required for Ang II-induced collagen upregulation.

Angiotensin II↗
PubMed2000

Spinal cord infarction following vertebral angiography: clinical and pathological findings.

Spinal cord damage from radiographic contrast material has been known to occur in both spinal and nonspinal angiographic procedures. Reported here is cervical spinal cord injury (SCI) during vertebral angiography. During the procedure, the patient displayed signs of acute cervical spinal cord irritation that should have been taken as a warning of impending injury. Autopsy 9 years later showed evidence of central cervical spinal cord necrosis. The pathological findings are similar to those seen in animal models of contrast media-induced SCI; and the pathophysiological mechanisms of such injury are discussed.

Angiography↗
PubMed1999

Systematic review of risk factors for urinary tract infection in adults with spinal cord dysfunction.

Recurrent urinary tract infections (UTIs) occur frequently in persons with neurogenic bladders due to spinal cord dysfunction, resulting in increased morbidity and cost. The authors conducted a systematic review to identify risk factors for UTI using controlled clinical trials, cohort, and cross-sectional studies that assessed risk factors for UTI and included bacteriuria or UTI as an outcome. Twenty-two studies met the inclusion criteria. Quality assessment revealed important methodological deficiencies. Two studies provide evidence supporting increased bladder residual volume as a risk factor. Most of the retrieved studies investigated method of drainage with the consistent finding that persons using intermittent catheterization had fewer infections than those with indwelling catheters. There is conflicting evidence over the value of sterile or "no touch" catheter techniques compared with clean intermittent catheterization. There is insufficient evidence to assess risk due to psychosocial, behavioral, and hygiene factors; sex; level of function; and time since injury.

Adult↗
PubMed1994

Linking radiosilver to monoclonal antibodies reduced by ascorbic acid. Comparison of results with stable silver using gravimetric technique and silver 110-M using radiotracer technique.

Radiosilver-111 and Radiogold-199 were proposed by us (1) as suitable isotopes for radioimmunotherapy in areas such as India by reason of their suitable half-lives and B-emissions (Ag-111 T1/2 = 7.45 d and Au-199 T1/2 = 3.15 d). Since silver is monovalent, it is difficult to link to conventional bifunctional chelates. We therefore explored the use of sulfur-based linkers (2). Encouraged by the Thakur and De Fulvio Technique (3) of linking technetium to disulfide groups in antibodies reduced by ascorbic acid that is eminently biocompatible, we have explored the linkage of silver to immunoglobulin reduced by ascorbic acid. The linkage of silver was assessed with stable Ag-108 using dialysis to quantify the free silver after the reaction of silver and reduced immunoglobulins in various molar ratios (1:1, 1:2, 1:5, 1:10). The silver quantity was estimated gravimetrically after precipitation as chloride. It was observed that using these molar ratios there was negligible silver efflux into the dialysate, suggesting stable linkage. We also assessed the linkage using Ag-110M as radiotracer. The comparative results with the two techniques are described.

Antibodies, Monoclonal↗
PubMed1994

Removal of endotoxin from antibody preparations for clinical use. Assessment of polymyxin-sepharose CNBr affinity chromatography.

Despite attempts to maintain asepsis, good manufacturing practices, and the use of terminal sterilization by millipore filtration, the nuclear practitioner is always worried about the possibility of endotoxin contamination. Methods, such as ion-exchange chromatography, have been tried for removing endotoxins during the preparation of radiolabeled antibodies, and so on. As suggested by Stevenson (1990), we evaluated the Issekutz technique (1) of endotoxin removal by affinity chromatography using a polymyxin cyanogen bromide (CNBr) Sepharose column. The endotoxin content of millipore filtrates of heat killed/sonicated suspensions of Pseudomonas pyocyaneus, E. coli were measured using a Sigma (St. Louis, MO) Endotoxin Assay Kit before and after filtration through such columns and compared with the results obtained using gel exclusion and ion-exchange columns of the same length and diameter. Reduction of endotoxin content to undetectable levels by the polymyxin column was observed. The use of such columns for terminal endotoxin removal analogous to terminal sterilization is advocated especially when developing a radiopharmaceutical such as radiolabeled antibodies for in house use.

Antibodies, Monoclonal↗
PubMed1992

Effects of plant extract Centella asiatica (Linn.) on cold restraint stress ulcer in rats.

Extract of C. asiatica (Linn.) inhibited significantly gastric ulceration induced by cold and restraint stress (CRS) in Charles-Foster rats, Antiulcer activity of plant extract was compared with famotidine (H2-antagonist) and sodium valproate (anti-epileptic). Plant extract, formotidine and sodium valproate showed a dose dependent reduction of gastric ulceration. Plant extract increased brain GABA level which was also dose dependent. Pretreatment with bicuculline methiodide (specific GABAA-antagonist) at the dose level of 0.5 mg/kg im, reversed the antiulcerogenic activity of both plant extract and sodium valproate. Bicuculline as such did not induce gastric ulceration in normal rat.

Animals↗
PubMed1989

Hats: design and protection from ultraviolet radiation.

An estimated 400,000 non-melanoma skin cancers occur each year. A majority of them will develop on sun-exposed areas of the face, head, and neck. By virtue of having assignments that involve outdoor duty, often in areas of high ultraviolet radiation exposure, military personnel are at increased risk of developing these cancers. Hats provide a means of sun protection; however, some styles are more protective than others. Two styles of hats currently used by the military are compared.

Female↗
PubMedDate not supplied

Blood lines.

Explore the source record for details and available documents.

Health Education↗
PubMedDate not supplied

Perceived morbidity, utilisation of health services and factors affecting it in a rural area.

A survey of perceived morbidity was carried out in rural population in eight villages and four wards of Saoner town, covering a total population of 8,876. The nature of illness was assessed by weekly visits to the families. History regarding treatment taken for disease and its source was taken. The overall incidence of perceived morbidity was 176.35 spells of sickness per 1000 population per month. Health care agency was contacted for 36.7 per cent spells of sickness. Utilisation of health services was found to be affected significantly by factors like age (chi 2 = 138.36), literacy (chi 2 = 14.123), type of occupation (chi 2 = 433.74), nature of illness (chi 2 = 83.578) and accessibility of health services. A health behaviour model of the population has also been discussed in this paper.

Analysis of Variance↗
PubMedDate not supplied

Expression of the neutral amino acids transporter ASCT1 in esophageal carcinomas.

Cancers cells utilize more glucose and amino acids than their benign counterparts. Overexpression of the facilitative glucose transporter Glut1 in human cancers was found to correlate with aggressive biologic behavior. The aim of this work was to determine whether the neutral amino acid transporter ASCT1 is expressed in human esophageal carcinomas, and to correlate the findings with Glut1 expression. Sections of formalin-fixed and paraffin-embedded tissue from 42 cases of esophageal carcinomas were entered in the study. Immunohistochemical staining was performed using a rabbit anti-ASCT1 IgG developed in our laboratory, and anti-Glut1 antibody, using standard avidin-streptavidine immunoperoxidase method. Sections of formalin-fixed and paraffin-embedded HepG2 cells were used as positive controls. The percent of ASCT1-positive cells was scored. Statistical analysis was performed using Fisher's exact test. ASCT1 immunoreactivity was cytoplasmic, whereas Glut1 was membranous. Significantly more adenocarcinomas expressed ASCT1 than squamous cell carcinomas (p < 0.0001), whereas Glut1 expression was similar in both tumor types. There was no association between the expression of either transporter and lymph node metastasis. Glut1 was expressed more often in the better differentiated than the poorly differentiated squamous carcinomas (p = 0.003). These results suggest that unlike in squamous cell carcinoma, ASCT1 plays a significant role in the recruitment of amino acids in adenocarcinoma of the esophagus, and suggest that the metabolic needs, and uptake of nutrients, are regulated differently in these two tumor types. Additional studies with larger number of patients are needed to determine the biological significance of ASCT1 expression in esophageal carcinomas.

Adenocarcinoma↗