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Biomedical subjects

R Sehgal

Publications and source records attributed to R Sehgal.

At least 19 recordsLinked to original sources
PubMed2006

Development of passive haemagglutination (PHA) and haemagglutination inhibition (HAI) technique for potency estimation of Cobra Antisnake Venom Serum (ASVS).

Antibodies against snake venom or antivenom potency are assayed quantitatively by in-vivo neutralization test in mice, which requires large number of laboratory animals. In potency assays of biological substances such as antivenoms, it is highly desirable to avoid suffering and death of animals by substituting in-vivo method with in-vitro methods, provided such methods measure life-saving capability with precision similar to that of in-vivo method. The in-vitro tests determine the neutralizing power of antivenom by permitting the evaluation of a particular biological activity of the venom and its neutralization after mixing the venom with the antivenom [Theakston RDG, Reid HA. Development of simple standard assay procedures for the characterization of snake venom. Bull WHO 1983;61:949-956; Gutierrez JM, Rojas G, Lomonte B, Gene JA, Chaves F, Alvarado J, et al. Standardizing of assays for testing the neutralizing ability of antivenoms. Toxicon 1990;28:1127-1129; Theakston R.D.G. Comments on letter of Gutierrez et al. on standardization of assays for testing the neutralizing ability of antivenoms. Toxicon 1990;28:1131-1132; Harvey AL, Barfaraz A, Thomson E, Faiz A, Preston S, Harris JB. Screening of snake venom for neurotoxic and myotoxic effects using simple in-vitro preparation from rodents and chicks. Toxicon 1994;32:257-265; World Health Organization Progress in characterization of venom and standardization of anti-venoms. Geneva: WHO offset publication; 1981. p. 58.]. Hence, the ideal requirements for an assay in detecting venom and venom antibody include high level of sensitivity, specificity (ability to differentiate between venom and venom antibody produced by closely related species of snakes), reproducibility and simplicity. A new in-vitro procedure for quantitative analysis of potency of ASVS by passive haemagglutination (PHA) and haemagglutination inhibition (HAI) has been explored. The methods described are simple, rapid, economical, reproducible and useful in replacing the more expensive in-vivo neutralization assays. Moreover, it also eliminates the use of laboratory animals.

Animals↗
PubMed2006

A comparative study on the efficacy of rofecoxib in monoarticular arthritis induced by latex of Calotropis procera and Freund's complete adjuvant.

The role of prostaglandins in Calotropis procera latex induced inflammation and hyperalgesia has been well established. The acute inflammation induced by the dried latex (DL) of this plant could be effectively ameliorated by standard anti-inflammatory drugs. In present study we have evaluated the efficacy of rofecoxib, a COX-2 inhibitor in monoarthritis induced by intra-articular injection of DL and compared it with that against Freund's Complete Adjuvant (FCA). DL and FCA were injected into the right ankle joint of the rat and the joint diameter was measured by a micrometer screw gauge on day 0, 4, 8, 12, 20 and 28. Concomitantly the hyperalgesic response was also evaluated by motility test, stair climbing ability test, dorsal flexion pain test and compression test. The effect of rofecoxib was evaluated on these parameters in both the models. Both DL and FCA produced peak inflammation on day 4 that was associated with decreased pain threshold and functional impairment. Although rofecoxib was more effective in improving motility in the DL model, its effect on joint inflammation, hyperalgesia and stair climbing ability was comparable in both the models. Thus, our study indicates that DL induced monoarthritis could be used as a model for the screening and evaluation of anti-inflammatory and anti-arthritic drugs.

Administration, Oral↗
PubMed2006

Evaluation of cytotoxic potential of latex of Calotropis procera and podophyllotoxin in Allium cepa root model.

In the present study we have utilized the Allium cepa root tip meristem model to evaluate the cytotoxic and anti-mitotic activities of latex of Calotropis procera (DL) and podophyllotoxin. Standard cytotoxic drug cyclophosphamide and non-cytotoxic drugs cyprohcptadine and aspirin served as controls. Like cyclophosphamide, both DL and podophyllotoxin significantly inhibited the growth of roots and mitotic activity in a dose-dependent manner. However, podophyllotoxin was more potent in this regard and produced root decay. Cyproheptadine and aspirin, on the other hand, showed a marginal effect on the root growth and mitotic activity at much higher concentrations.

Calotropis↗
PubMed2005

Antioxidant and protective effect of latex of Calotropis procera against alloxan-induced diabetes in rats.

In the present study, dry latex (DL) of Calotropis procera possessing potent anti-inflammatory activity was evaluated for its antioxidant and anti-hyperglycemic effects against alloxan-induced diabetes in rats. Daily oral administration of DL at 100 and 400 mg/kg doses produced a dose-dependent decrease in the blood glucose and increase in the hepatic glycogen content. DL also prevented the loss of body weight in diabetic rats and brought down the daily water consumption to values comparable to normal rats. DL also produced an increase in the hepatic levels of the endogenous antioxidants, namely superoxide dismutase (SOD), catalase and glutathione, while it brought down the levels of thiobarbituric acid-reactive substances (TBARS) in alloxan-induced diabetic rats. The efficacy of DL as an antioxidant and as an anti-diabetic agent was comparable to the standard anti-diabetic drug, glibenclamide.

Alloxan↗
PubMed2005

Laparoscopic-assisted ileo-colectomy for tuberculosis.

BACKGROUND: Laparoscopic-assisted colon resection (LACR) for benign disease has gained acceptance and has a lower morbidity than open surgery. Reports in Western literature have outlined the use of LACR for diverticulosis, ulcerative colitis, and Crohn's disease. We evaluated the use of LACR in patients with ileo-cecal tuberculosis (IC-TB) and describe our technique and results. METHODS: Twenty-six patients (20 F) between 16 and 45 years of age underwent a LACR for IC-TB over a 4-year period. Three access ports were used in 22 patients, four patients needed four ports. The cecum, ascending colon, proximal transverse colon, and terminal ileum were mobilized completely. The right colic vessels were divided intracorporeally. The specimen was delivered using a 5- to 6-cm incision. The ileo-colic pedicle and bowel were divided outside and an ileocolic anastomosis performed. After placing the bowel within the abdomen the pneumoperitoneum was recreated, saline irrigation done, and hemostasis achieved. RESULTS: No patient needed a formal laparotomy. Peristalsis returned within 48 h in 19 patients and after 72 h in the remaining seven. Oral liquids were started on all patients by the 3rd postoperative day (POD) and a soft diet by the 5th POD. Twenty patients had a bowel movement by the 4th POD and the rest by the 5th POD. Eighteen patients were discharged by the 5th day and the remaining by the 7th day. Three patients developed wound sepsis. Twenty-one patients could resume normal activity within 2 weeks, the rest within a month. CONCLUSION: Laparoscopic-assisted colon resection seems to be an ideal operation for patients with ileo-cecal tuberculosis. It has minimal morbidity and allows a quick return to normal activity.

Adolescent↗
PubMed2005

Pediatric HIV infection.

OBJECTIVE: The present cross sectional study was undertaken to study clinical profile of HIV infection in children in Northern India. METHODS: 64 children from newborn to eighteen years, presenting for confirmation of diagnosis of HIV infection or monitoring of CD4-CD8 counts in confirmed cases, were evaluated. Children were categorized as per CDC classification of Pediatric HIV. The diagnosis was confirmed by serological tests or PCR assay. CD4-CD8 counts were done by FACS Count. RESULTS: Majority of the children were between 18 months to 5 years. Adolescents comprised 24% of the case. 51.5% children were infected through the mode of mother to child transmission. 39% of the case was transfusion-mediated. Unsafe medical injections probably contributed to 6.2% and heterosexual promiscuity led to 3.1% cases. Clubbing, not described in Indian studies so far, was seen in 9.3% cases. CONCLUSIONS: HIV infection is a chronic childhood disease extending into adolescence, and contaminated blood and unsafe medical injections are still important routes of HIV transmission in India.

Adolescent↗
PubMed2005

Altered lipid parameters in patients infected with Entamoeba histolytica, Entamoeba dispar and Giardia lamblia.

Information on the effect of parasitic infections on lipid parameters is scarce. Certain parasites induce significant changes in lipid parameters, as demonstrated by the fact that substitution of lipid/cholesterol for serum in axenic culture medium (in vitro) and in experimental models (in vivo) supports vigorous growth of Entamoeba histolytica. Thus, significant changes in lipid parameters may be induced in an infected host. Blood samples are obtained from intestinal amoebiasis patients passing E. histolytica (n=8), E. dispar (n=15) or Giardia lamblia (n=9) cysts, or diagnosed with amoebic liver abscess (ALA; n=50) and from apparently normal healthy individuals (control group; n=30). Levels of total serum cholesterol, high-density lipoprotein and low-density lipoprotein are assessed using commercial kits. E. histolytica and E. dispar isolates are differentiated by hexokinase isoenzyme electrophoresis and by enzyme-linked immunosorbent assay (ELISA; Techlab) tests. Results show that E. histolytica, E. dispar and G. lamblia cyst passers had significantly lower levels of total serum cholesterol (73.42 +/- 2.24 mg/dL), compared to levels in ALA cases (101 +/- 2.85 mg/dL) and in controls (166.26 +/- 2.02 mg/dL). Further study of a greater number of cases is needed to explore the relevance of this finding.

Adolescent↗
PubMed2005

Prevalence of parenterally transmitted hepatitis viruses in clinically diagnosed cases of hepatitis.

Hepatitis B virus (HBV) is the most important causative agent of blood borne hepatitis in humans. Hepatitis D Virus (HDV) infection occurs either as a coinfection or superinfection in HBV carriers. Hepatitis C virus (HCV) is the major cause of transfusion non-A, non-B hepatitis and continues to be a major cause of human liver disease throughout the world. The present study was conducted on 70 clinically diagnosed cases of viral hepatitis to study the prevalence of parenterally transmitted viral hepatitis. The serum samples were tested for HBsAg, HBeAg, IgM anti-HBc, anti-HBe, anti-HCV and anti-HDV using separate ELISA kits. Of the 70 serum samples tested, 28 (40%) were positive for HBsAg out of which 3 (4.28%) were positive for HBeAg also. Five (7.1%) of the HBsAg positive cases tested positive for IgM anti-HBc also. HBsAg alone was found in 17 (24.28%) cases. The prevalence of anti-HCV was 3 (4.28%) in 70 cases. Thus early screening of clinically diagnosed cases of viral hepatitis is essential for establishing diagnosis and treatment to prevent long term sequelae.

Adult↗
PubMed2003

SEN virus infection--a new hepatitis virus: a review.

Approximately 10% of transfusion associated hepatitis and 20% of community acquired hepatitis cases do not have a defined etiology, suggesting the existence of an additional causative agent. The recent agents which have been detected in blood were Hepatitis G virus (HGV) and TT virus (TTV), members of the family Circoviridae. These viruses were initially thought to be associated with post-transfusion hepatitis but later studies negated this causal effect. Recently, a novel DNA virus at the moment designated as SEN virus (SEN-V) was discovered and is thought to be associated with post-transfusion hepatitis. This virus is related to the above two agents and belongs to the same family. Whether, like HGV and TTV causal relationship with hepatitis is finally confirmed only time will tell, but, at the moment the association appears to present. The present review summarizes the present available data on this new agent of hepatitis.

Hepatitis Viruses↗
PubMed2002

Naegleria meningitis: a rare survival.

Acute amebic meningoencephalitis caused by free-living amebae naegleria fowleri is extremely rare and uniformly fatal with only seven survivals reported till date. An interesting case of naegleria meningitis diagnosed by wet mount cytology of cerebrospinal fluid (CSF) and treated with amphoterecin B, rifampicin and ornidazole with complete recovery is presented. In cases of suspected pyogenic meningitis, if CSF staining, antigen detection or culture is negative for bacteria, a wet mount cytology of CSF for naegleria is suggested. Early treatment with amphoterecin B and rifampicin may improve survival.

Adult↗
PubMed2002

Acanthamoeba adherence to soft contact lens and human corneal stroma.

In the present study, the adhesibility of Acanthamoeba castellani trophozoites and cysts to hydrogel contact lenses and to human cornea was investigated. Segments of unworn contact lenses were prepared (120 segments in total). In addition, 8 corneal buttons were obtained from 8 enucleated eyes. And each cornea cut into 8 radial segments. To these lens and corneal segments, 1.2 x 106/ml and 1.3 x 106/ml of cysts and trophozoites respectively were added under varying conditions. The adhesion was checked at 0, 3 and 24 hours after the exposure. Adhesion analysis showed that the trophozoites adhered equally well to lens or cornea. There is an increase in the number of trophozoites adhering to contact lenses as well as cornea. This difference is more significant for contact lenses. Washing of contact lenses significantly decreased the adherence of the trophozoites after 3 hours of incubation. When the comparison of adhesion was done between the unwashed worn and unwashed unworn contact lenses, it was observed that there was a significant difference in adherence to new lenses where the adherence was much lower. The study shows that washing of contact lenses does decrease the chances of colonization by Acantamoeba catellani and also that older lenses have higher chances of getting colonized probably due to the occurrence of scratches et. on the surface which may help in colonization.

Acanthamoeba↗
PubMed2002

Hepatitis G virus (HGV): current perspectives.

Five viruses are usually associated with hepatitis in humans: A-E. In addition to these viruses as aetiological agents of hepatitis, there remain a number of patients with hepatitis in whom no virus could be identified. It was therefore postulated that there may be other agents which may be causing hepatitis. Recently, two viruses have been associated with hepatitis: hepatitis G virus (HGV), and transfusion transmissible virus (TTV). Hepatitis G virus (HGV) is a single stranded RNA virus which represents a newly discovered virus belonging to the flavivirus family. HGV is distinct from hepatitis C virus (HCV) and the newly discovered GBV-A and GBV-B agents, while GBV-C represents an isolate of HGV. The structure of the HGV genome resembles that of HCV. HGV replicates in peripheral blood cells, while replication in liver cells has not been observed till date. Diagnosis of HGV infection is mainly by use of polymerase chain reaction (PCR), as serological techniques are still being developed. Epidemiological data indicate that the virus is prevalent throughout the world, including India and is transmitted via blood/blood products, sexually and vertically from infected mothers to children. The relationship between infection with the virus and presence of liver pathology is controversial and has not been proven beyond doubt, as majority of patients with HGV have no detectable evidence of disease.

Child, Preschool↗
PubMed2001

Receptor-Ck regulates giardia encystation process.

The study addressed to resolve the mechanism involved in cholesterol-dependent regulation of giardia encystation process, revealed that (a) the trophozoites have the ability to express genes coding for receptor-Ck and sterol element binding protein (SREBP); (b) inhibition of cholesterol dependent activation of receptor-Ck results in the upregulation of CWP-1 gene expression leading to encystation process. Based upon these findings, we propose that receptor-Ck dependent signalling is responsible for the regulation of giardia encystation process by cholesterol.

Animals↗
PubMed2000

Isolation of emetine resistant clones of Entamoeba histolytica by petri dish agar method.

Emetine resistant clones of Entamoeba histolytica strain HM1:IMSS were isolated by using petri dish agar method after mutation with ethyl-methanesulphonate. Two emetine resistant clones were obtained and both were resistant to emetine at a concentration of 24 micrograms/ml of emetine. The 50 per cent inhibitory concentration (IC50) for both emetine sensitive and resistant clones was 5 and 14 micrograms/ml respectively. The colony forming efficiency of E. histolytica strain HM1:IMSS varied from 44 to 54 per cent. This method is useful for isolating clones from different strains of the parasite for molecular and immunological studies.

Agar↗