Investigation of an outbreak of chikungunya in Malegaon Municipal areas of Nasik district, Maharashtra (India) and its control.

BACKGROUND & OBJECTIVES: An outbreak of chikungunya fever occurred in Malegaon town of Nasik district of Maharashtra state, India during February and March 2006. A total of 4530 fever cases were reported during this period including 1781 cases which were admitted in different hospitals of the town. An entomological and epidemiological investigation was carried out in the affected villages during the outbreak to study the possible causes of the outbreak and to isolate the virus responsible. METHODS: Entomological evaluation was done as per WHO guidelines. Sera samples were collected by venipuncture from clinically suspected chikungunya patients in hospitals and also during house-to-house survey in affected villages. IgM antibodies to dengue virus were detected using IgM capture ELISA (PANBIO) and by "Haemagglutination inhibition test" for detection of antibodies against Chikungunya virus. Acute sera samples were inoculated in cell lines for virus isolation. The isolates were confirmed by RT-PCR. RESULTS: On investigation, it was found that water storage containers like cement tanks, plastic containers or earthen pots placed in front of the individual houses were the potential breeding sites for Aedes aegypti. Entomological survey carried out in the most affected areas revealed high Aedes indices. House, container and breteau indices were found to be 27.2, 16.19 and 35.1, respectively. Out of the 13 acute sera samples collected, virus was isolated in 10 samples. The isolates were confirmed by RT-PCR and sequencing using primers from nsP1 gene of Chikungunya virus (CHIKV, Accession No. EF077609, EF077610). Of the 17 convalescent sera tested, significant level of HI antibodies to CHIKV was detected in five samples. One sample was positive for IgM antibodies against dengue virus. Based on clinico-epidemiological features and laboratory findings, the illness was confirmed to be of chikungunya viral disease. CONCLUSION: Control measures targeting the vector population and personal protective measures against the mosquito bites were instituted. Extensive IEC campaign with the involvement of community and religious leaders helped in containment of the disease.

Entomological indices of Aedes aegypti at some international airports and seaports of southern India--a report.

Entomological surveys were undertaken at some of the international airports/seaports (Bangalore, Calicut, Chennai, Cochin, Thiruvanathapuram and Vishakapatnam) to find out the breeding prevalence of dengue vector mosquito in diverse breeding containers from 1998 to 2004. Three vector indices (House index, Container index and Breateu index) were used to assess the breeding potential at each airport/seaport. International Health Regulations urged national governments to keep all the international airports/seaports and peripheral areas up to 400 meters free from Aedes aegypti mosquitoes. However, surveys revealed high vector indices at all the airports and seaports. Health authorities of airports/seaports need to take cognizance of these facts and develop action plan for appropriate control measures with emphasis on vector surveillance.

Lipid composition and amino acid uptake during rotavirus infection and protection with trypsin inhibitor in malnourished infant mice.

The aim of the study was to evaluate the influence of rotavirus (RV) and soyabean trypsin inhibitor (TI) on lipid composition and uptake of glucose and glycine in rotavirus (RV) infected malnourished (PEM) infant mice. Malnutrition was achieved in animals by doubling the litter size. Cholesterol (Ch) and phospholipd (PL) contents, uptake levels of glucose and glycine were determined in jejunum and ileum portion of small intestine. Increase in Ch/PL ratios was observed in PEM+RV group. The levels became comparable in PEM+RV+TI as compared to PEM. Uptake levels of glucose and glycine increased in PEM animals. With rotavirus (PEM+RV+TI group), the levels decreased which became comparable to PEM. Changes in uptake and lipid composition with rotavirus and trypsin inhibitor may be responsible for altering membrane fluidity and organization during rotavirus diarrhea. The results establish the importance of trypsin inhibitor during oral infection with rotavirus.

Mild-to-moderate malnutrition and small intestine of young rhesus monkeys.

The effect of severe malnutrition and protein deficiency on small intestine has been documented, but the literature on the effect of mild-to-moderate protein-energy malnutrition (PEM) on small intestine is scant. Mild-to-moderate PEM is most prevalent in India. Twenty-four young rhesus monkeys weighing 1.5-2.0 kg were divided into two groups, control and experimental. Mild-to-moderate PEM was induced in the experimental group by giving half of the required normal diet providing 2.42 g protein.kg-1.day-1 and 55 kcal.kg-1.day-1. Body weight, serum protein, and D-xylose were measured before starting the experiment, at PEM stage, and after rehabilitation. Experimental monkeys representing group I were killed after a 25-30% reduction in body weight along with control group 1 animals at 12 wk. The rest of the experimental animals were rehabilitated for another 10-12 wk and killed along with their respective controls (control group 2). Brush-border membrane vesicles were prepared from three parts of the small intestine. Viable vesicles were used for the uptake of [U-14C]L-proline. Alkaline phosphatase and enterokinase were also measured. Uptake of L-proline amino acid and the activity of both enzymes were found to be decreased significantly in the PEM group; a D-xylose test was abnormal. All animals recovered after rehabilitation. These results indicate that even mild-to-moderate malnutrition affects the absorptive and digestive capacity of the brush border of the small intestine, which reversed back on rehabilitation.

Study of oxidative-stress in rotavirus infected infant mice.

Rotavirus induced diarrhoea was investigated in neonatal mice. Assessment of oxidative/antioxidative profile was the mechanistic approach to study the nature of injury. Neonatal mice (NMRI strain) were infected orally with the homologous strain of (EB) rotavirus (serotype 3). The peak severity of rotavirus infection was attained on the third day post infection. The whole small intestine of neonatal mice on day 3 post infection was homogenized and analysed for oxidative/antioxidative profile. Glutathione and related thiols were significantly declined in rotavirus infected group. Superoxide dismutase, glutathione peroxidase and glutathione-S-transferase (1-chloro 2, 4 dinitrobenzene) activities were also decreased in the rotavirus infected group. The activities of glutathione reductase and glutathione-S-transferase (ethacrynic acid) however were elevated with rotavirus infection in comparison to the control group. Similarly, ADP-FeCI3, NADPH induced lipid peroxidation was elevated with rotavirus infection. Thus the altered oxidative/antioxidative profile indicated the presence of oxidative stress in the rotavirus infected group and can be postulated to have a prominent role in the pathogenesis of the disease.

Protection against rotavirus challenge in mice orally inoculated with trypsin inhibitor.

BACKGROUND AND OBJECTIVES: the burden of rotavirus disease is significant in developed as well as developing countries and has not diminished with improved hygiene. In the present studies the protective efficacy of soyabean trypsin inhibitor (TI) was investigated on the gut following rotavirus (RV) infection in inbred mice. METHODS: infant BALB/c mice of 7 days age (n=108) were divided into three equal groups (control, RV and RV+TI). Animals were orally inoculated either with normal saline, EB RV (serotype-3) or RV+TI and were sacrificed under light chloroform anesthesia on days 0, 1, 3, 5, 7 and 10 post inoculation (pi). Gamma-glutamyl transpeptidase (GGT), leucine aminopeptidase (LAP), and leucine amino acid uptake in the jejunum and ileum were assessed. RESULTS: rotavirus inoculated animals showed significant reduction in body weights on days 3 and 5 pi as a result of diarrhoea which resolved by day 7 pi. In RV+TI inoculated animals diarrhoea jejunum and ileum in mice inoculated with RV as compared to controls. With the administration of TI the amino acid uptake, and GGT and LAP levels were higher in both segments of the small intestine and comparable to the controls. INTERPRETATION AND CONCLUSIONS: on the administration of TI, leucine amino acid uptake, and levels of GGT and LAP were similar to the controls in the jejunum and ileum of infant mice showing its possible protective efficacy during rotavirus infection.

Oral aluminum administration and oxidative injury.

For a long time, aluminium (Al) has been considered an indifferent element from a toxicological point of view. In recent years, however, Al has been implicated in the pathogenesis of several clinical disorders, such as dialysis dementia, the fulminant neurological disorder that can develop in patients on renal dialysis. In the present study, the effect of chronic oral administration of Al on certain biochemical parameters of brain homogenate has been investigated. The feeding of test diet for 6 wk resulted in a decrease of thiols, glutathione reductase (GR), and adenosine Triphosphatase (ATPase). A nonsignificant decrease in peroxidation and glutathione-S-transferase (GST) was also detected in the Al-treated rats. From this study, it can be concluded that oxidative stress is produced by the metal.

Protein-energy malnutrition and oxidative injury in growing rats.

1. Weaning rats were fed ad libitum isocaloric diets containing 5% and 20% casein based proteins. 5% protein diet was protein deficient diet. Pair fed rats with the 5% protein group were maintained simultaneously on 20% protein diet but the amount restricted to the amount taken up by PEM group. 2. Glutathione, antioxidative enzymes, lipid peroxidation and histopathological studies in liver and only glutathione and antioxidative enzymes in blood were carried out. 3. Rats fed the 5% protein diet developed a severe protein energy malnutrition (PEM) whereas those on pair-fed diet developed mild to moderate PEM. 4. Glutathione related thiols superoxide dismutase, glutathione peroxidase, catalase and glutathione-Stransferase with (1 Chloro 2,4-dinitro benzene (CDNB) substrate) were decreased in liver with concomitant increase of lipid peroxidation in severe PEM. In blood glutathione, glutathione peroxidase and catalase were decreased while superoxide dismutase was increased in severe PEM group. 5. Mild to moderate PEM (pair-fed group) also resulted in similar changes in liver except glutathione peroxidase, lipid peroxidation in liver and superoxide dismutase in blood. 6. Hepatic injury was detectable only in the severe PEM group. 7. Oxidative-stress and hepatic injury occurred in severe PEM and to a lesser degree in mild to moderate PEM.

Isoniazid- and rifampicin-induced oxidative hepatic injury--protection by N-acetylcysteine.

The role of N-acetylcysteine (NAC), a glutathione (GSH) precursor, was investigated in protection against isoniazid- (INH) and rifampicin- (RIF) induced oxidative hepatic injury in young Wistar rats. The hepatotoxic dose of INH and RIF was 50 mg kg(-1) day(-1) each and the hepatoprotective dose of NAC was 100 mg kg(-1) day(-1). All drugs were administered intraperitoneally (i.p.) in sterile water (4.0 ml kg(-1) day(-1)) over a period of 3 weeks. Status of oxidative/antioxidative profiles was the mechanistic approach to assess the hepatotoxicity and/or hepatoprotection. The oxidative injury in INH-RIF co-exposed animals was closely associated with significant decline of GSH and related thiols, as well as with compromised antioxidant enzyme system. The oxidative stress was further supported by increased lipid peroxidation observed in these animals. The co-administration of NAC prevented the induction of oxidative stress in INH-RIF co-exposed animals. The amelioration of oxidative stress by NAC was faithfully reflected as normal morphology in these animals, except the presence of mild degree of portal triaditis in one animal co-exposed to INH-RIF and NAC. In contrast, the animals co-exposed to INH-RIF alone showed histological lesions which ranged from intralobular inflammation to patchy necrosis. These results suggest that INH-RIF-induced oxidative injury can be prevented by supporting the cellular antioxidant defense mechanism by NAC.

Effect of rotavirus infection on lipid composition and glucose uptake in infant mouse intestine.

OBJECTIVE: To study the effect of rotavirus infection on lipid composition and glucose uptake in small intestine of infant mice. METHODS: Thirty six 7-day old balb/c mice were given 50 mL (100 ID50) rotavirus suspension orally; 36 control animals received only normal saline. Body weight of animals was recorded. Six animals in each group were sacrificed on days 0, 1, 3, 5, 7 and 10 post-inoculation (pi). Intestines were removed, everted and homogenized in ice-cold saline. Cholesterol and phospholipid content, glucose uptake and alkaline phosphatase in the jejunum and ileum were determined. RESULTS: Rotavirus infection led to a significant decrease in body weight with on days 3 and 5 pi as compared to controls, and to an increase in cholesterol and phospholipid content of the intestine. Uptake of glucose also increased significantly. Alkaline phosphatase activity was significantly reduced on days 3 and 5 pi as compared to controls. CONCLUSION: This study provides characterization of the lipid composition and uptake of glucose in infant mice small intestinal segments during rotavirus infection.

Alterations in duodenal disaccharidases in chronic smokers.

OBJECTIVE: To assess the effect of smoking on activity of intestinal disaccharidases. METHODS: The study was conducted on patients with non-ulcer dyspepsia who were smokers (n=20) or non-smokers (n=20). Smokers were classified according to smoking index into mild, moderate and heavy smokers. Biopsy specimens were taken from the second part of the duodenum at endoscopy and examined histologically, and for disaccharidase (lactase, sucrase, maltase and trehalase) activities. RESULTS: Mean duration of symptoms was more in smokers than in non-smokers. None of the smokers had endoscopic evidence of duodenal inflammation. Lactase and trehalase levels were significantly decreased in smokers. There was no difference in enzyme levels between mild smokers and non-smokers. Decreased lactase, maltase and trehalase activities were observed in moderate smokers compared to mild smokers. Duration of symptoms had no relation to enzyme activities. CONCLUSIONS: Intestinal disaccharidase levels are diminished by smoking.

Rotavirus infections.

In 1976, John Rohde, highlighting the importance of diarrhea as prime killer of children in the developing world, beckoned the scientific community to "take science where the diarrhea is". The World Health Organization estimates that one billion diarrheal episodes occur in infants annually resulting in 3.3 million deaths, making diarrheal disease a major contributor to infant mortality in developing world (Bern et al., 1992). The need for simple, effective and inexpensive intervention to treat diarrhea and to prevent its occurrence is urgent and abundantly clear. Among the etiological agents of acute infectious diarrhea rotaviruses account for nearly 25% of hospital admissions in India with vomitting and diarrhea followed by severe dehydration in very young children below 2 years of age (Broor et al., 1985). In developing countries, it has been estimated that more than 870,000 children die from rotavirus infection every year (Perez-Schael, 1996). The discovery of rotavirus by Bishop and colleagues in 1973 initiated a line of research that has progressed rapidly towards the goal of prevention of rotavirus diarrhea (Bishop et al., 1973).

Comparison of duodenal and jejunal disaccharidase levels in patients with non ulcer dyspepsia.

AIMS: This study was conducted to compare the duodenal and jejunal disaccharidase levels in the same individual with duodenal ulcer or non ulcer dyspepsia. METHODS: Thirty seven patients (duodenal ulcer--11, non-ulcer dyspepsia--26) were included in the study. Endoscopic biopsy samples were obtained from jejunum and duodenum using pediatric colonofibroscope. RESULTS: Levels of jejunal disaccharidases were significantly higher than the duodenal disaccharidases. CONCLUSIONS: An estimate of jejunal disaccharidases can be had by multiplication of duodenal disaccharidased by a factor 1.48 for lactase, 1.50 for sucrase and 1.56 for maltase.

Lactose intolerance in different types of irritable bowel syndrome in north Indians.

BACKGROUND: Twenty-five patients of irritable bowel syndrome (IBS) and 25 normal healthy individuals serving as controls, were studied for lactose intolerance. METHODS: Hydrogen breath test was used as an investigation after giving 50 g of oral lactose. Clinically, the patients were classified into 3 types of IBS. RESULTS: Eleven (44%) out of 25 patients belonged to diarrhoeal type of IBS, 7 (28%) of 25 patients to spastic and rest 7 (28%) of 25 patients had features of both types of symptoms. Lactose hydrogen breath test was abnormal in 9 cases (82%) of 11 diarrhoeal type of IBS which was significantly higher (p < 0.02) than controls. However, the difference of abnormal hydrogen breath test between spastic type of IBS and patients with features of both types was not significant as compared to controls. CONCLUSIONS: These results suggest that patients with diarrhoeal type of IBS have a higher incidence of lactose intolerance as compared to spastic type as well as patients with features of both types.

Soybean trypsin inhibitor confers protection against rotavirus infection in infant mice.

OBJECTIVE: To study the effects of soybean trypsin inhibitor (TI) on glycine uptake, glutathione (GSH) levels and morphological changes of intestine in rotavirus (RV) infected infant mice. METHODS: A total of 144 infant mice (7/8 days old) were divided in 3 groups (i.e. control, RV and RV + inhibitor). Infant mice were orally inoculated with the EB strain of RV and Trypsin protease inhibitor (TI) and 8 animals each were sacrificed on days 0,1,3,5,7 and 10 post infection (p.i). Glycine uptake (in vitro), GSH levels and histological changes were assessed in the jejunum, ileum and colon. RESULTS: Glycine uptake and GSH levels were significantly reduced on days 3 and 5 p.i in jejunum and ileum of RV inoculated animals, compared to the controls. Glycine uptake and GSH levels were maintained as in controls in the RV + TI inoculated animals on days 3 and 5 p.i in jejunum and colon but not in ileum where lesser values were recorded. Histology showed vacuolar degeneration in ileum towards the apical portion whereas normal morphology was observed in jejunum, similar to controls. No histological changes were observed in colon in any of the groups. Electron microscopic study confirmed the viral infection. CONCLUSION: Administration of Trypsin protease inhibitor along with RV reverted the effects of RV infection on amino acid uptake and GSH levels completely in the jejunum and partially in the ileum.

Effect of Giardia lamblia on duodenal disaccharidase levels in humans.

The study was conducted to detect the effect of giardiasis on human disaccharidase levels. Forty patients attending the medical outpatient department of PGIMER, Chandigarh were enrolled. Twenty patients, positive for Giardia lamblia comprised the study group while 20 patients negative for Giardia lamblia were taken as controls. Upper gastrointestinal endoscopy was performed in all patients. Estimation of lactase, sucrase, maltase and trehalase was done in biopsies. Histopathological investigation was carried out in all biopsy specimens after Haematoxylin and Eosin staining. Complaints of pain abdomen and bloating occurred commonly in giardiasis. Four biopsy samples in study group showed mild increase in lymphomononuclear infiltrate. Giardia lamblia was detected in 7 biopsies. Lactase levels were decreased significantly (p < 0.05) in giardiasis. Rest of the enzymes were comparable to the controls. No differences in the enzyme activities were observed between males and females in either group and with the duration of symptoms.

Protective effect of N-acetylcysteine in isoniazid induced hepatic injury in growing rats.

Status of oxidative/antioxidative profile was the mechanistic approach to inumerate the nature of protection by N-acetylcysteine (NAC) in isoniazid (INH) exposed experimental animals. Analysis of lipid peroxidation, thiol levels, cytochrome P450, superoxide dismutase (SOD), catalase, glutathione peroxidase, reductase and transferase were estimated in liver along with the body and liver weight of animals and histological observations. Isoniazid exposure to animals resulted in no change in body and liver weights. Thiols, lipid peroxidation, catalase, SOD glutathione peroxidase, reductase, transferase and cytochrome P450 levels were altered with INH exposure. Supplementation of NAC with INH protected the animals against hepatotoxic reactions by minimizing the free radical induced tissue injury and overall maintenance of the endogenous scavengers of free radicals.

Protection against rotavirus diarrhoea in mice by trypsin inhibitor.

To investigate the role of soyabean trypsin inhibitor (TI) during rotavirus (RV) diarrhoea, changes in enzyme activities of six relevant mucosal enzymes (lactase, sucrase, maltase, trehalase, glucoamylase and alkaline phosphatase) were assayed following inoculation of suckling mice with EB rotavirus (serotype 3) along with the TI and compared with the age-matched healthy control mice. The animals were divided into three groups i.e. group 1 (controls), group 2 (RV inoculated) and group 3 (RV + TI inoculated and sacrificed under light anaesthesia on 0, 1, 3, 5, 7 and 10 day post inoculation (dpi). Then intestines were excised and divided into two parts (jejunum and ileum). They were separately homogenized in 0.9% cold normal saline and activities of mucosal enzyme were measured. Alkaline phosphatase and disaccharidases were found to be decreased significantly in RV inoculated animals in both the anatomical portions of small intestine of mice. These enzyme levels were restored with the administration of TI i.e. in group 3 and became comparable to the controls in both intestinal portions. These studies suggest that activity of intestinal enzymes which are important in digestive absorptive functions of small intestine were restored with the addition of TI whengiven to infant mice showing its protective efficacy during rotavirus infection.

Effect of alcohol dependence on the levels of duodenal disaccharidases in human subjects.

BACKGROUND: The aim of the study was to detect the duodenal enzyme activity in patients of alcohol dependence and to compare with non-alcoholic patients of non-ulcer dyspepsia. METHODS: Disaccharidases (lactase, sucrase, maltase) were estimated in 20 non alcoholic patients of non-ulcer dyspepsia and 20 alcoholics admitted to the drug de-addiction and treatment centre of PGIMER, Chandigarh, India. RESULTS: No significant influence of alcohol on enzyme levels in patients of alcohol dependence when compared to patients of non-ulcer dyspepsia was observed. However, a significant decrease in lactase level was noted in patients consuming more than 125 gm/day of alcohol. CONCLUSION: Amount of consumption of alcohol showed decrease in lactase enzyme, but not in maltase and sucrase. There was no effect of duration of alcohol consumption on dissacharidases in the two groups.