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Biomedical subjects

P Nigam

Publications and source records attributed to P Nigam.

At least 19 recordsLinked to original sources
PubMed1995

Simultaneous raw starch hydrolysis and ethanol fermentation by glucoamylase from Rhizoctonia solani and Saccharomyces cerevisiae.

Crude glucoamylase preparation from Rhizoctonia solani was used to saccharify raw and cooked starch. Various concentrations of potato starch and wheat flour from 10-40%, w/v were used for mashing but 30% was found to be the optimal and economical. The saccharified mash yielded 5.89%, v/v ethanol in a simultaneous saccharification and fermentation process using a yeast strain Saccharomyces cerevisiae (SC-39) at 35 degrees C for 4 days. Removal of inhibitory substances from the fermenting broth through dialysis caused considerable increase in ethanol production.

Ethanol↗
PubMed1994

Production, partial characterization, and potential diagnostic use of salicylate hydroxylase from Pseudomonas putida UUC-1.

An unusual strain of Pseudomonas putida UUC-1 capable of growth at high salicylate concentration (10 gl-1) was investigated with the aim of developing an assay and a biosensor system for determining salicylate in body fluids by utilizing the salicylate hydroxylase enzyme. Medium and growth condition optimization were carried out under chemostat conditions. The highest biomass yield was at 4.0 gl-1 salicylate, 25 degrees C, pH 6.5, and 0.2 h-1 dilution rate. Growth occurred at up to 0.45 h-1 dilution rate, producing 236 Ul-1 enzyme activity and an output of 424 U h-1. The activity and productivity were higher than any reported in the literature for this enzyme. It had a Km value of 2.07 +/- 0.32 microM and an M(r) of approximately 43,000. In addition, its specific activity in the crude extract (0.8-0.9 U mg-1 protein) was similar to the commercially available enzyme. No plasmid DNA was detected in this strain, and no salicylate-negative isolates were obtained when curing with mitomycin C. It is therefore proposed that our strain has a chromosomally located inducible salicylate hydroxylase gene that enables it to grow at high salicylate. This strain also offers a means of cheaply producing large quantities of the enzyme through standard fermentation techniques.

Biosensing Techniques↗
PubMed1993

Production of the enzyme dihydrofolate reductase by methotrexate-resistant bacteria isolated from soil.

Six bacterial cultures isolated from soil were capable of growing in the presence of methotrexate (MTX). Two strains, PFR-1 and 3, developed resistance to 500 micrograms cm-3 MTX in the medium and produced elevated levels of the enzyme dihydrofolate reductase (EC 1.5.1.3): 2580 and 2702 U dm-3 compared to the sensitive parent strains (28 and 35 U dm-3). Isolate PFR-3 showed maximum enzyme production (4950 U dm-3, specific activity 12.56 U mg-1 in flasks and 5737 U dm-3, specific activity 14.80 U mg-1 in 5-dm3 fermenter) during exponential phase of growth (6 h) at 37 degrees C and pH 7.0.

Chromatography, High Pressure Liquid↗
PubMed1993

Dihydrofolate reductase synthesis in continuous culture using a methotrexate-resistant Escherichia coli.

A methotrexate-resistant strain of Escherichia coli Type I produced exceptionally high levels of the enzyme dihydrofolate reductase (EC 1.5.1.3) in 6 h of batch fermentation. The culture had markedly improved performance under chemostat culture conditions in terms of enzyme yield and output. Temperature, pH, dilution rates, and nutrient composition were optimized under chemostat culture conditions. A maximum enzyme yield of 10,360 U l-1 and a specific activity of 22.84 U mg-1 were obtained under chemostat conditions at pH 7.0, temperature 37 degrees C, and dilution rate 0.2 h-1, using media containing 1.0 and 0.6% (w/v) dextrose and yeast extract, respectively. The culture's performance and enzyme yields in chemostat and the feasibility of large-scale production are discussed.

Bacteriological Techniques↗
PubMed1991

Clinical profile of herpes zoster ophthalmicus.

Herpes zoster ophthalmicus was seen in 22 cases out of 195 cases of herpes zoster (11.3% incidence). It was affecting mainly adults (90.9%). Oedema over the lids (81.8%) was invariably present and lead to ptosis. Mucopurulent conjunctivitis, predominantly mucoid (72.7%) was the commonest manifestation associated with vesicles over the lid margins. Sectorial (22.7%) and diffuse (9.1%) episcleritis appeared in later part of first week, while nodular episcleritis was observed in one case only on 12th day of the disease. Nummular keratitis was seen in 31.8% of cases between 8-10 days. Iritis and iridocyclitis was seen in 45.4% of cases out of which 36.3% had secondary ocular hypertension (glaucoma). Neuroparalytic keratitis and internal ophthalmoplegia were detected in one patient each. Postherpetic neuralgia occurred in 22.7% of cases and was uncommon in younger age group (below 40 years, 4.5%). Carbamazepine was effective in relieving the herpetic pain.

Adolescent↗
PubMed1991

Clinical profile of giardiasis and comparison of its therapeutic response to metronidazole and tinidazole.

Seventy five cases (50 males, 25 females; mean age 20.2 +/- 5.8 years), whose stools were positive for cysts and/or trophozoites of Giardia lamblia, were studied for their clinical profile and therapeutic response to metronidazole and tinidazole. Maximum frequency of cases (41.2%) was noted upto 20 years of age, and it declined with advancing age. A majority of them (41.3%) presented with non-specific symptoms while 38.6% were asymptomatic parasite carriers. Features of malabsorption were observed in 12% of cases and 8% presented with acute illness, having explosive, watery, foul smelling diarrhoea along with crampy upper abdominal discomfort. Most of them (62.5%) had blood group A. Tinidazole (97.5%) was more efficacious (P less than 0.01) than metronidazole (54%) in a single dose of 50 mg/Kg, with good tolerance. Tinidazole can be recommended for the treatment of giardiasis in individual cases as well as in families and close communities.

Adolescent↗
PubMed1990

Betel chewing and dental decay.

A survey was carried out on Four hundred and sixty patients to find out the effects of betel chewing on dental caries & oral hygiene. It was found that among the betel chewers as well as the non betels chewers., the highest caries susceptibility was in the age group of 20-34 years. Also caries susceptibility was higher among the females as compared to males. It was also observed that though the habit of betel chewing reduces the incidence of dental decay, maintenance of oral hygiene is very poor.

Adolescent↗
PubMed1988

Male gonads in leprosy--a clinico-pathological study.

Sixty male leprosy patients (mean age 27.2 +/- 5.04 years) selected at random, were studied for gonadal involvement with the mean duration of illness 4.17 +/- 3.27 years. Only lerpomatous and borderline leprosy cases developed testicular and epididymal changes. Testicular pain and/or swelling (lepromatous 62.5%, borderline 30%) was the main presenting feature. Altered sexual function was observed in 34(56.6%) cases, and 11 patients revealed altered sexual hair pattern. Gynecomastia was seen in 9 cases. Reduced testicular size along with its soft feeling was present in 25% of cases while no testicular sensation was felt in 8 (13.3%) cases, and impaired testicular sensation in 9 (15%) of them. Spermogram revealed azoospermia in 19 (35%) and oligospermia in 16 (26.6%) cases. Histo-pathology revealed evidences of leprous pathology irrespective of testicular size, semen picture and clinical manifestations. There was marked variation in histopathological findings in testes and hence it was difficult to categorise them into vascular, interstitial and obliterative phase.

Adolescent↗
PubMed1987

Clinical experience with the use of peripheral vasodilator in oral disorders.

Conventional therapies practised in the treatment of asymptomatic neuralgia, oral submucous fibrosis and paraesthesic numbness, are empirical and symptomatic in nature. These are usually prolonged and may be inadequate, impractical with complete or incomplete remissions associated with or without relapses. High dosages of drugs administered for longer duration, are also not infrequently without side-effects. With these problems in view, the clinical use of nylidrin hydrochloride a peripheral vasodilator, was experienced for over 10 years. Irrespective of age, sex and status, 97 cases were randomly extracted from the hospital and oral surgery clinical records. The projected sample included 33 cases of asymptomatic neuralgia, 58 cases of oral submucous fibrosis and 6 cases of numbness. Neuralgia, where mean age was 50 years, was treated with nylidrin hydrochloride, vitamin B-complex and carbamazepine. Oral submucous fibrosis where mean age was 38 years, was treated with nylidrin hydrochloride, vitamins A,E,B-complex, iodine, placental extract, local and systemic corticosteroids and physiotherapy. Paraesthesic numbness, following iatrogenic or accidental trauma to the affected nerve, was treated with nylidrin hydrochloride and B-complex therapy. Peripheral vasodilator administered in all 97 cases, initially contained low divided doses, which steadily were increased or decreased as per individual response. There were reportedly no side-effects, except complaints of flushingly warm skin. Supportive therapy with antibacterials, tranquilizers and analgesics, along with minor dental surgery, were given as and when required. The success rate was 72.16% in total, while individually it varied from 84.85% in neuralgia, 62.07% in oral submucous fibrosis and 100% in numbness.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

Cholestasis in amoebic liver abscess.

Two hundred and thirty six patients with amoebic liver abscess were investigated for cholestasis, its mechanism and the natural course of the disease. Cholestasis was seen in 29% of cases and it presented with some unusual features: it was frequently seen in young men (mean age 38.6 +/- 6.3 years) (87%) with acute onset (69%) and was associated with signs of peritonism, or peritonitis (28%), splenomegaly (12%) and hepatic encephalopathy (coma 13%). Raised diaphragm was seen only in 37% of cases. Alcoholism may have contributed to the cholestasis in 37% of cases. Multiple (43%) and single (32%) large liver abscesses, especially on the inferior surface of the liver (25%), were common in jaundiced patients with amoebic liver abscess, while size and number of abscesses were directly related to the raised serum bilirubin concentrations. Bromsulphalein excretion (BSP) was found to be significantly reduced (p less than 0.01) in patients with jaundice (60%). Retrograde injection of contrast media into the common bile duct during six necropsies showed compression by amoebic liver abscess on the hepatic ducts. The mortality (43%) and the complications were significantly higher (p less than 0.001) in patients with jaundice. The aspiration/surgical drainage of amoebic liver abscess together with a combination of metronidazole and di-iodohydroxyquinoline was more effective than either metronidazole alone, or dehydroemetine with chloroquine.

Adolescent↗