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S K Khanna

Publications and source records attributed to S K Khanna.

At least 19 recordsLinked to original sources
PubMed2005

Justifying the need to prescribe limits for toxic metal contaminants in food-grade silver foils.

The use of silver foils in various food preparations is a common practice in Middle Eastern and South East Asian countries. The FAO/WHO Joint Expert Committee on Food Additives (JECFA) has included silver in the list of food additives, but specifications were not prepared. Indian food legislation has included food-grade silver foil and laid down a purity requirement of 99.9%. This leaves an unspecified margin of 0.1% or 1000 microg g(-1) for contaminants. Therefore, a study to investigate the levels of metallic contaminants in food-grade silver foil was undertaken. Of 178 foils analysed, 161 (90%) contained silver, whilst 10% were fraudulently made up of aluminium. In the case of silver foils, 46% of the samples adhered to the desired purity requirement of 99.9%, while 54% had a lower silver content. Copper was present in 86.3% of the silver foils, while chromium, nickel and lead contamination was found in over 54% of samples. Cadmium levels were detected in 28% of the silver foils and manganese was present in 6.8% of samples. In silver foils showing metal contaminants, average levels were found for nickel (487 microg g(-1)), lead (301 microg g(-1)), copper (324 microg g(-1)), chromium (83 microg g(-1)), cadmium (97 microg g(-1)) and manganese (43 microg g(-1)), which being appreciable justify the need to prescribe limits for some metals in food-grade silver foil as well as for silver powder used in confectioneries and medicinal preparations. The work reported here should encourage manufacturers to use high-purity raw materials and take suitable precautions to reduce unwarranted exposure of consumers to toxic metal contaminants.

Aluminum↗
PubMed2003

Xanthogranulomatous cholecystitis.

Twelve cases of xanthogranulomatous cholecystitis are reported. The clinical presentation was similar to chronic cholecystitis. All patients had associated gallstones. The diagnosis was achieved at histopathological examination of the resected gall bladders and none had any focus of malignancy. Cholecystectomy was curative.

Adult↗
PubMed2002

Toxicity of argemone oil: effect on hsp70 expression and tissue damage in transgenic Drosophila melanogaster (hsp70-lacZ) Bg9.

The effect of argemone oil on hsp70 expression and tissue damage was investigated by studying beta-galactosidase activity, Western blotting and hybridization, and trypan blue staining in the larval tissues of transgenic Drosophila melanogaster (hsp70-lacZ)Bg9. Different concentrations of argemone oil were mixed with food and third-instar larvae were allowed to feed on them for different time intervals (2, 4, 24, and 48 h). Argemone oil was found to induce hsp70 even in the lowest concentration of the adulterant while maximum tissue damage was observed in the higher two treatment groups. Malpighian tubules and midgut tissue reflected maximum damage as evidenced by both high beta-galactosidase activity and trypan blue staining in these tissues. A prior temperature shock treatment to the larvae was enough to protect the larvae from argemone oil-induced tissue damage as evidenced by little or no trypan blue staining. The present study suggests the cytotoxic potential of argemone oil and further strengthens the evidence for the use of hsp70 as a biomarker in risk assessment.

Animals↗
PubMed2001

Quantitative determination of aflatoxin B1-oxime by column liquid chromatography with ultraviolet detection.

Liquid chromatography was used for the quantification of aflatoxin B1-oxime (AFB1-oxime). The yield of AFB1-oxime in the reaction mixture was 89%, while after purification on silica gel it was 72%. LC analysis of the reaction mixture after silica gel fractionation revealed a retention time of 0.84 min for AFB1-oxime, 8.42 min for AFB1, 1.21 min for unknown 1 and 1.61 min for unknown 2. UV-visible analysis of the reaction mixture after silica gel fractionation showed a lambda(max) of 269 and 361 nm for AFB1-oxime, 263 and 360 nm for AFB1, 273 nm for unknown 1 and 275 nm for unknown 2. Excitation and emission wavelengths were found to be 269 and 368/438 nm for AFB1-oxime, 359/424 nm for AFB1, 270 and 367/450 nm for unknown 1 and 273 and 416/447 nm for unknown 2. The method may find versatile application in monitoring reactions for the preparation of oximes of various analytes for the synthesis of their immunogens.

Aflatoxin B1↗
PubMed2001

Role of biological antioxidants in benzanthrone toxicity.

Previous studies indicate that benzanthrone, an anthraquinone dye intermediate, caused significant depletion of ascorbic acid (AsA). In this investigation the effect of benzanthrone on the status of different forms of AsA and other bio-antioxidants such as glutathione (GSH) was studied. Oral administration of benzanthrone (50, 125 or 250 mg/kg body weight) resulted in a significant increase of urinary AsA levels with a concomitant decrease in the urinary dehydroascorbic acid (DHA) content in both rats and guinea-pigs. Benzanthrone caused a dose-dependent decrease in hepatic, adrenal and serum AsA levels with a subsequent increase in DHA and diketogulonic acid (DKA) levels in both rats and guinea-pigs. Following benzanthrone treatment, rats showed an increase in the scorbutic index (to 1.01-1.21) of the liver, adrenal glands and serum compared to controls (0.12-0.24). The scorbutic indices of liver, adrenal glands and serum were also substantially increased (to 3.61-11.20) in benzanthrone-treated guinea-pigs compared to controls (0.16-0.38). Single oral administration of benzanthrone to guinea-pigs caused a dose-dependent depletion of GSH in liver (15-51%), adrenal glands (27-64%) and serum (32-86%). Furthermore, the depletion of GSH by benzanthrone in rats was of a lesser degree. This suggests that continued exposure of guinea-pigs to benzanthrone may lead to scurvy-type changes in this animal species but not to the same extent in rats, since the latter has the enzymatic capacity to synthesise AsA. Therefore, it can be hypothesised that benzanthrone per se, or its metabolites, interact with reduced GSH thereby causing its depletion. Furthermore, in order to replenish the depleted GSH levels, AsA might be oxidized to DHA and hence the decrease in AsA with the simultaneous increase in DHA was observed.

2,3-Diketogulonic Acid↗
PubMed2000

Intracystic tetracycline therapy for hypofunctioning cystic thyroid nodules.

OBJECTIVES: Hypofunctioning benign cystic thyroid nodules are a common occurrence in iodine deficient region. There are reports of resolution of recurrent thyroid cysts with tetracycline instillation. Hence we conducted a study in 20 patients with hypofunctioning benign cystic thyroid nodules to document response to intracystic instillation of tetracycline as a primary modality of treatment. METHODS: Twenty patients were thoroughly investigated for the presence of malignancy clinically, radiologically and cytologically. One milliliter of tetracycline was instilled under ultrasonographic guidance. Response to therapy was assessed clinically and ultrasonographically at one, three, six and 12 months. RESULTS: Study group comprised of five male and 15 female patients with mean age 30 +/- 8 years. Initial mean volume of nodules was 15 +/- 7 ml (6 to 27 ml), which was decreased to 3 +/- 3 ml at one month, 2 +/- 3 ml at three months, and 1 +/- 2 ml at six months. Maximum number of patients (75%) responded within three months, however two patients required reaspiration and reinstallation of tetracycline. Ultrasonography revealed fibrotic scar as thick wall with internal echodensities in six patients (30%) six month after sclerotherapy. There was high rate of patient satisfaction, as cosmetically tetracycline did not leave any scar, which was unavoidable with surgery. Six patients (30%) reported mild pain after injection, and one patient developed redness at the site of injection. CONCLUSIONS: Intracystic tetracycline sclerotherapy is highly effective as primary mode of treatment in hypofunctioning benign cystic thyroid nodule in selected group of patients not at high risk of malignancy.

Adult↗
PubMed1998

Role of cytochrome P-450 in quinalphos toxicity: effect on hepatic and brain antioxidant enzymes in rats.

Quinalphos (QP), an organophosphate pesticide, is used in controlling the pests of a variety of crops. To understand the mechanism of the metabolic basis of the toxicity of QP it was thought pertinent to study the role of cytochrome P-450 (P450) and antioxidant enzyme systems. Albino rats treated orally with QP (0.52 and 1.04 mg/kg body weight) for 60 days showed a significant decrease in body, brain and liver weights. Hepatic P450 content and its dependent monooxygenases, namely aryl hydrocarbon hydroxylase (AHH) and ethoxyresorufin-O-deethylase (ERD), were induced to 1.8-2.5-fold, while neuronal AHH was induced to 1.8-fold following QP treatment (1.04 mg/kg) to animals. The hepatic antioxidant defence system, comprising catalase, glutathione (GSH) reductase, superoxide dismutase (SOD) and GSH peroxidase, was also significantly increased in QP-treated animals, while in the brain only catalase was increased and GSH reductase decreased. There was no significant change in hepatic GSH content and lipid peroxide levels in QP treated animals at any dose group in comparison with the control group. Pretreatment of rats with phenobarbitone (PB) or 3-methylcholanthrene (MC) (P450 inducers) prevented mortality caused by the LD50 dose of QP, whereas pretreatment with cobalt chloride (a P450 inhibitor) enhanced the mortality rate to 100% within 3 days. From the above study it can be inferred that the toxicity of QP may be due to the parent compound or its metabolite(s) produced prior to P450 oxidation and that the induction of P450 system by QP may be a defence mechanism.

Acetylcholinesterase↗
PubMed1998

Early postoperative enteral feeding in patients with nontraumatic intestinal perforation and peritonitis.

BACKGROUND: In our clinical setting, patients with perforative peritonitis are frequently malnourished. Immediate postoperative enteral feeding has been shown effective in reducing septic morbidity in patients with abdominal trauma. This study was designed to investigate the feasibility and efficacy of immediate postoperative enteral feeding in patients with nontraumatic intestinal perforation and peritonitis. STUDY DESIGN: A prospective study spanning 1 year was conducted on patients with nontraumatic intestinal perforation and peritonitis. After laparotomy, patients were assigned randomly to a control or study group. The study group underwent a feeding jejunostomy and received enteral feeding from 12 hours postoperatively. A low-residue, milk-based diet was used. All patients underwent assessment for severity of sepsis and nutritional status at admission. Studies of nutritional status and nitrogen balance were repeated on days 4 and 7. RESULTS: Forty-three patients (21 in the study group; 22 in the control group) were included. The two groups were comparable except for a higher sepsis score in the study group (p < 0.05). Patients in the study group achieved a positive nitrogen balance by the third postoperative day; patients in the control group remained in negative nitrogen balance throughout the study. Abdominal distention (four patients) required temporary withdrawal of feeding. Diarrhea occurred in four patients but was controlled easily. The mortality rate was similar in the control and study groups (18.2% versus 19.1%). The control group had a total of 22 septic complications, versus eight in the study group (p < 0.05). CONCLUSIONS: Immediate postoperative feeding is feasible in patients with perforative peritonitis and reduces septic morbidity.

Adult↗
PubMed1998

Azo reductase activity of microbial population from gastrointestinal tract segments of various animals species.

Azo reductase activity of microbial population of stomach, small intestine, caecum and large intestine of different animals was investigated. There was low activity in stomach flora of wistar rat and 3 strains of mice. Flora of proximal portion of small intestine in different species revealed that carnivorous animals exhibited maximum activity followed by grazing animals. Maximum activity in middle portion of small intestine was noted in dog (98.2%), while minimum was observed in guinea pig (23.3%). Majority of test animals revealed maximum floral azo reductase activity (58-98%) in caecum. Activity in proximal portion of large intestine was highest in dog while pigeon and guinea pig had least activity (23.3-27.1%). Appreciable microbial activity in distal end of large intestine was noted in sheep and goat. In all the 15 animal species investigated caecum showed maximum activity followed by pre and post caecal segments while stomach possessed the least. The results suggest that inter-species differences exist in microbial reductive activity which may be due to variation in composition and distribution of GI tract microflora and thus can influence toxicological implication of various dyes.

Animals↗
PubMed1997

Traditions and reproductive technology in an urbanizing north Indian village.

This article addresses the practices of prenatal sex determination and sex-selective abortion through ethnographic research in Shahargaon, a Jat village undergoing rapid urbanization and cultural change in north India. The paper presents the sociodemographic outcomes of sex-selective abortion practiced within a system of patriarchy, manifested in terms of son preference and daughter disfavor. It argues that changes from an agriculture to an urban economy have led to a decrease in family size among Shahargaon Jats. In spite of improvements in educational and economic status, there is a reinforcement of son preference and daughter disfavor in the Jat community in Shahargaon. Jat couples are using prenatal sex determination and sex-selective abortion to achieve smaller family size and to reduce the number of daughters in a family.

Abortion, Induced↗
PubMed1997

Metanil yellow: a bifunctional inducer of hepatic phase I and phase II xenobiotic-metabolizing enzymes.

Metanil yellow, a non-permitted food colour, has been found in various foodstuffs. The induction potential of metanil yellow on hepatic microsomal cytochrome P-450 (P-450)-dependent monooxygenases and cytosolic detoxification enzymes, namely, glutathione S-transferase (GST) and quinone reductase (QR), was investigated. Oral administration of metanil yellow (430 mg/kg body weight) to four animals for seven days caused significant induction of hepatic P-450 (48%) and its dependent aryl hydrocarbon hydroxylase (100%) activity and cytosolic GST (136%) and QR (92%) activities. Parenteral administration of metanil yellow (80 mg/kg body weight) to another set of four animals for 3 days resulted in higher induction of ethoxyresorufin-O-deethylase (228%) as compared to other monooxygenases (64-92%), while GST and QR were also found to be induced (59-95%). Spectra of metanil yellow-induced microsomes showed an increase in P-450 with a shift of 2.2 nm in the soret region. The results suggest that metanil yellow acts as a bifunctional inducer of specific isozymes of P-450 and cytosolic enzymes and thus may involve the cytosolic aryl hydrocarbon (Ah) receptor for this type of induction.

Administration, Oral↗
PubMed1997

Sinus venosus atrial septal defects: surgical follow-up.

OBJECTIVE: To assess early and later results after surgery for sinus venous atrial septal defects (ASDs). METHODS: Forty-four patients of sinus venosus ASDs with anomalous drainage of the right superior pulmonary vein into the superior vena cava, were operated upon between January 1985 and June 1995. Defects were approached by an incision starting from the tip of the right atrial appendage then extending upward along the atrial crest to the medial wall of the superior vena cava. Atrial defects were closed by an autologous pericardial patch. Another pericardial patch was used to enlarge the superior vena cava-right atrial junction to avoid the narrowing of the superior vena cava. RESULTS: There was no operative mortality. The total duration of follow-up was 4 +/- 0.7 years. Follow-up of the echocardiographic study at 6 months and 2 years after surgery revealed a normal study. Two patients developed sinus node dysfunction of short duration in the immediate postoperative period. Follow-up of the electrocardiographic study at 6 months and 2 years revealed sinus node dysfunction in one and two patients, respectively.

Adolescent↗
PubMed1997

Clinicoepidemiological, toxicological, and safety evaluation studies on argemone oil.

Consumption of oil extracted from accidental or deliberate contamination of argemone seed to mustard seed is known to pose a clinical condition popularly referred to as Epidemic Dropsy. Several outbreaks of Epidemic Dropsy have occurred in the past in India as well as in Mauritius, Fiji Island, and South Africa. Clinico-epidemiological manifestations of argemone oil poisoning include vomiting, diarrhea, nausea, swelling of limbs, erythema, pitting edema, breathlessness, etc. In extreme cases, glaucoma and even death due to cardiac arrest have been encountered. The toxicity of argemone oil has been attributed to two of its physiologically active benzophenanthridine alkaloids, sanguinarine and dihydrosanguinarine. Histopathological studies suggest that liver, lungs, kidney, and heart are the target sites for argemone oil intoxication. Studies have shown to elucidate the cocarcinogenic potential of argemone oil that can be correlated with the binding of sanguinarine with a DNA template. Pharmacological response in intestine revealed immediate stimulation of tone and peristaltic movements of the gut in the sanguinarine-treated animals. Argemone oil/Sanguinarine caused a decrease in hepatic glycogen levels which may be due to the activation of glycogenolysis leading to an accumulation of pyruvate in the blood of Epidemic Dropsy cases. The increase in pyruvate levels causes uncoupling of oxidative phosphorylation leading to breathlessness, as observed in patients. Sanguinarine has been shown to inhibit Na+, K(+)-ATPase activity of different organs such as brain, heart, liver, intestine, and skeletal muscle, which may be due to the interaction with the glycoside receptor site on ATPase enzyme, thereby causing a decrease in the active transport of glucose. Argemone oil/alkaloid showed a Type II binding spectra with hepatic cytochrome P-450 (P-450) protein, thereby causing loss of P-450 content and an impairment of phase I and phase II enzymes. A green fluorescent metabolite of sanguinarine, benzacridine was detected in the milk of grazing animals. The delayed appearance of this metabolite in urine and feces of experimental animals suggests the slow elimination of the alkaloid. Argemone oil enhances hepatic microsomal and mitochondrial lipid peroxidation, indicating that these two organelles are the sites of membrane damage. Furthermore, studies suggest that singlet oxygen and hydroxyl radical are involved in argemone oil toxicity. Several bioantioxidants show protective effect in argemone oil-induced toxicity in experimental animals. The line of treatment in argemone-intoxicated epidemics has so far been only symptomatic, and specific therapeutic measures are still lacking, although it has been suggested that diuretics, bioantioxidants, steroids, vitamins, calcium- and protein-rich diet had some beneficial effects on Epidemic Dropsy cases.

Animals↗
PubMed1997

Reductive and hydrolytic activities of enteric bacteria on food colours.

Reductive and hydrolytic activities on two food colours namely metanil yellow and indigo carmine by different strains of enteric bacteria were evaluated. Enteric bacteria possessed both reductive and hydrolytic capabilities which depended upon the incubation period and the type of strain. In certain bacterial strains, (Escherichia coli and Vibrio sp.), reductive activity was visible after 3 hr. Other enteric strains showed an increasing activity right from the beginning of incubation. Enterobacter cloacae appeared to be producing maximum reductive capability followed by Enterobacter aerogenes and E. coli. Even enteric bacterial strains demonstrated a good response in obtaining hydrolytic activity of indigo carmine during incubation upto 10 hr, establishing the fact that the gut microflora may cause health problem to consumers.

Adult↗
PubMed1997

Comparative azo reductase activity of red azo dyes through caecal and hepatic microsomal fraction in rats.

In order to study the rate of formation of toxic aromatic amines, anaerobic reduction of four red azo dyes viz. amaranth, carmoisine, fast Red E and ponceau 4R was investigated by incubating caecal content and hepatic microsomal fraction of rats with 37.5 microM concentration of dyes in sodium phosphate buffer pH 7.4 using NADPH generating system, glucose oxidase system and nitrogen as the gaseous phase. Caecal suspension exhibited higher azo reductase activity than that of hepatic microsomal fraction using any of the 4 azo dyes. Caecal microbes showed maximal azo reductase activity when ponceau 4R was used as a substrate followed by fast Red E and carmoisine, while with amaranth the activity was minimum. Similarly ponceau 4 R exhibited maximum hepatic microsomal azo reductase activity followed by fast Red E and carmoisine whereas, amaranth had minimum activity. Caecal flora possessed almost 17 fold higher degradative capability of ponceau 4 R and fast Red E colourants than the hepatic microsomal fraction. The higher reductive ability through caecal flora for ponceau 4R and fast Red E signifies the formation of more aromatic amines which may be re-absorbed through the intestine to be either eliminated through urine as conjugates or retained in the target tissues to elicit toxic effects.

Animals↗
PubMed1996

Coeliac artery aneurysm: a case report.

Coeliac artery aneurysms are rare. A case of coeliac artery aneurysm treated successfully by endoaneurysmorrhaphy is presented. Although excision with arterial reconstruction is usually recommended, endoaneurysmorrhaphy can also be considered in selected cases.

Aneurysm↗
PubMed1996

Balloon mitral commissurotomy: an intraoperative assessment.

OBJECTIVE: Advances in balloon catheter technology have revolutionized the management of obstructive cardiovascular diseases. For lesions like mitral stenosis, balloon commissurotomy has emerged as an alternative to surgical relief showing definite functional benefits in a few clinical trials, albeit with variable results. Such variability necessitated objective evaluation of the efficacy of balloon mitral commissurotomy. METHODS: The balloon mitral commissurotomy was carried out in 11 patients suffering from isolated mitral stenosis, under vision in a surgical setting. All patients were in NYHA class III/IV. Initially single balloon was used for mitral commissurotomy followed by double balloon, before completing the mitral valvotomy with surgical instruments whenever required. The commissural split was measured by firmly stretching the two commissures using nerve hooks and measuring the distance between the two hooks with the help of a caliper. Assessment of balloon dilation was made by calculating exact percentage of residual commissural split following balloon dilation as compared with completed mitral valvotomy. The exact percentage of commissural split was thus obtained by subtracting residual commissural split following balloon dilation from commissural split obtained after surgical open mitral valvotomy. RESULTS: Complete commissurotomy using the balloon technique was possible in two (18.2%) patients. In the remaining nine (81.8%) patients, balloon expansion provided only 50% to 80% of commissural split and required instrumental completion with good results. CONCLUSIONS: Balloon mitral commissurotomy, by virtue of its circumferential force, helps to develop a good cleavage and attains good hemodynamic improvement which may be life saving in critical mitral stenosis in selected group of patients with pliable mitral leaflets and minimal subvalvular pathology.

Adolescent↗