Synthesis and characterization of AgI-Ag2O-SeO2 glass-nanocomposites embedded with beta-AgI and Ag2SeO3 nanocrystals.

Glass-nanocomposites of compositions xAgI - (1 - x)(0.40Ag2O-0.60SeO2) for 0.15 < or = x < or = 0.30 were prepared by quenching the melt of the appropriate mixtures of the chemicals AgI, AgNO3 and SeO2. Differential scanning calorimetry (DSC) was employed to determine the glass transition and crystallization temperatures. The as-prepared samples were heat-treated above glass transition temperature to observe the growth of nanoparticles. X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) were used to explore the microstructure of these samples. These studies revealed the presence of beta-AgI and Ag2SeO3 nanocrystals in both the as-prepared and heat-treated samples. The particle size was found to decrease with the increase of AgI content in both cases. The heat-treated samples showed increased tendency of crystallization for the compositions with higher AgI content. The beta-alpha phase transition of AgI crystals was observed at approximately 147-149 degrees C for heat-treated samples. Fourier transform infrared (FTIR) spectra revealed that the basic structure of the glassy network remained invariant to change of AgI content as well as to heat-treatment.

Functionalizing titania nanoparticle surfaces in a fluidized bed plasma reactor.

Functionalizing nanoparticle surfaces is essential for achieving homogeneous dispersions of monodisperse particles in polymer nanocomposites for successful utilization in engineering applications. Functionalization reduces the surface energy of the nanoparticles, thereby limiting the tendency to agglomerate. Moreover, reactive groups on the surface can also participate in the polymerization, creating covalent bonds between the inorganic and organic phases. In this paper, a fluidized bed inductively coupled plasma (FB-ICP) reactor is used to break apart the agglomerates and functionalize commercial TiO2 nanoparticle powders in a batch of several grams. The fluidized bed could be implemented into a continuous flow reactor, potentially making this a viable method to treat larger quantities of commercial powders. The particles are treated with acrylic acid (AA) and tetraethylorthosilicate (TEOS) plasma and the functionalized particles were collected separately from bulk powder. High resolution transmission electron microscopy (HRTEM) analysis showed that the particles were coated uniformly with polymer coatings with thicknesses around a few nanometers. Fourier-transformed infrared spectroscopy (FTIR) studies of the polymer-coated particles showed the presence of different functional groups (poly-acrylic acid/siloxane) similar to that present in the bulk films. The dispersion behavior of the TiO2 nanoparticles showed much improvement with reduced agglomerate size.

Comparative efficacy of antimicrobial treatments in dairy cows at dry-off to prevent new intramammary infections during the dry period or clinical mastitis during early lactation: a systematic review and network meta-analysis.

A systematic review and network meta-analysis were conducted to assess the relative efficacy of antimicrobial therapy given to dairy cows at dry-off. Eligible studies were controlled trials assessing the use of antimicrobials compared to no treatment or an alternative treatment, and assessed one or more of the following outcomes: incidence of intramammary infection (IMI) at calving, incidence of IMI during the first 30 days in milk (DIM), or incidence of clinical mastitis during the first 30 DIM. Databases and conference proceedings were searched for relevant articles. The potential for bias was assessed using the Cochrane Risk of Bias 2.0 algorithm. From 3480 initially identified records, 45 trials had data extracted for one or more outcomes. Network meta-analysis was conducted for IMI at calving. The use of cephalosporins, cloxacillin, or penicillin with aminoglycoside significantly reduced the risk of new IMI at calving compared to non-treated controls (cephalosporins, RR = 0.37, 95% CI 0.23-0.65; cloxacillin, RR = 0.55, 95% CI 0.38-0.79; penicillin with aminoglycoside, RR = 0.42, 95% CI 0.26-0.72). Synthesis revealed challenges with a comparability of outcomes, replication of interventions, definitions of outcomes, and quality of reporting. The use of reporting guidelines, replication among interventions, and standardization of outcome definitions would increase the utility of primary research in this area.

Comparative efficacy of teat sealants given prepartum for prevention of intramammary infections and clinical mastitis: a systematic review and network meta-analysis.

A systematic review and network meta-analysis were conducted to assess the relative efficacy of internal or external teat sealants given at dry-off in dairy cattle. Controlled trials were eligible if they assessed the use of internal or external teat sealants, with or without concurrent antimicrobial therapy, compared to no treatment or an alternative treatment, and measured one or more of the following outcomes: incidence of intramammary infection (IMI) at calving, IMI during the first 30 days in milk (DIM), or clinical mastitis during the first 30 DIM. Risk of bias was based on the Cochrane Risk of Bias 2.0 tool with modified signaling questions. From 2280 initially identified records, 32 trials had data extracted for one or more outcomes. Network meta-analysis was conducted for IMI at calving. Use of an internal teat sealant (bismuth subnitrate) significantly reduced the risk of new IMI at calving compared to non-treated controls (RR = 0.36, 95% CI 0.25-0.72). For comparisons between antimicrobial and teat sealant groups, concerns regarding precision were seen. Synthesis of the primary research identified important challenges related to the comparability of outcomes, replication and connection of interventions, and quality of reporting of study conduct.

An investigation into possible quantum chaos in the H2 molecule under intense laser fields via Ehrenfest phase space (EPS) trajectories.

By employing the Ehrenfest "phase space" trajectory method for studying quantum chaos, developed in our laboratory, the present study reveals that the H2 molecule under intense laser fields of three different intensities, I = 1 × 1014 W/cm2, 5 × 1014 W/cm2, and 1 × 1015 W/cm2, does not show quantum chaos. A similar conclusion is also reached through the Loschmidt echo (also called quantum fidelity) calculations reported here for the first time for a real molecule under intense laser fields. Thus, a long-standing conjecture about the possible existence of quantum chaos in atoms and molecules under intense laser fields has finally been tested and not found to be valid in the present case.

Response of pre-adult and adult stages of Trichuris muris to common anthelmintics in mice.

The common anthelmintics, oxantel, mebendazole, albendazole and pyrantel were assessed for their comparative activity against Trichuris muris in mice. Mice were infected with T. muris and the infection was maintained by a brief cortisone administration during the second week of infection. Mice carrying the infection with different life cycle stages, viz. fourth stage larvae (L4), pre-adult and adult stages were dosed with anthelminitics. The worm burdens in control infection groups varied although infection dose and other conditions were uniformly followed. With various dose regimens tested, oxantel was highly potent; it eliminated completely pre-adult and adult stages, respectively at 25 and 12.5 mg kg-1 dose levels with significant activity also against adult worms at a 1.56 mg kg-1 dose level and against pre-adults at a 6.25 mg kg-1 level. Pre-adults required twice the dose given to that of adults for complete (100%) activity. Mebendazole was the next most active; a dosage of 37.5 mg kg-1 was completely active against pre-adults whereas a dosage of 2 x 50 mg kg-1 was required for complete elimination of adult worms. In addition, about 90% of the worms were eliminated with a single dose of 150 mg kg-1. However, a significant activity was seen against adults at a 25 mg kg-1 level and pre-adults at 37.5 mg kg-1, the lowest level tested. In comparison, albendazole did not induce complete clearance of pre-adult and adult stages even when tested at dose levels as high as 150 and 2 x 75 mg kg-1, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adaptive cytoprotection of gastric surface epithelial cells against injury by physiologic concentrations of bile acid.

The purpose of this study was to determine whether adaptive cytoprotection of gastric mucosa could be demonstrated with concentrations of bile acid, which is normally found in the human stomach, and whether cyclooxygenase inhibition, in turn, could blunt the response. Surface epithelial cell exfoliation and ion fluxes were used as end points. A transduodenal gastric cannula was placed, and the pylorus/gastroesophageal junction was ligated in adult male Sprague-Dawley rats that had been anesthetized. In experiment 1 (N = 30), rat stomachs were exposed for 15 minutes to 5 ml of either a neutral test solution (160 mmol/L NaCl, pH 7) or 1 mmol/L acidified taurocholate (ATC) (100 mmol/L HCl, 60 mmol/L NaCl, 1 mmol/L taurocholic acid; pH 1.2). All rats were subsequently exposed for 15 minutes to 5 mmol/L ATC during which time mucosal injury was assessed by measuring net flux of H+, Na+, and K+, volume, and DNA efflux. In experiment 2 (N = 35), all stomachs were pretreated for 15 minutes with 1 mmol/L ATC before mucosal injury with 5 mmol/L ATC (15 minutes). Eighteen rats were pretreated with indomethacin (5 mg/kg) subcutaneously 75 minutes before the experiment was begun, and the same parameters were measured. Pretreatment of rat gastric mucosa with 1 mmol/L ATC significantly attenuated the mucosal injury that was seen with subsequent exposure to 5 mmol/L ATC, resulting in significantly (p less than 0.05) less luminal H+ loss (-16 +/- 4 vs -32 +/- 4 mEq/15 min) and DNA efflux (181 +/- 21 vs 270 +/- 25 micrograms/15 min) than the nonadapted group. Indomethacin pretreatment significantly attenuated the adaptive protective response, resulting in greater loss of H+ (-29 +/- 4 vs -18 +/- 3) and DNA efflux (190 +/- 35 vs 110 +/- 18, both p less than 0.05) after exposure to 5 mmol/L ATC. These studies demonstrate that adaptive cytoprotection of gastric mucosa occurs with physiologic concentrations of an irritant that is normally present in the stomach. Indomethacin blunts this effect, which suggests that adaptive cytoprotection in this setting may be mediated by production of endogenous prostaglandins.

Anthelmintic efficacy of amoscanate (C 9333-Go/CGP 4540) against various infections in rodents, dogs and monkeys.

The anthelmintic activity of Amoscanate (C 9333-GO/CGP 4540) has been studied in experimental infections with the human hookworm, Necator americanus, in hamsters; Nematospiroides dubius, Hymenolepsis nana and natural infections with Syphacia obvelata in mice; Ancylostoma caninum, A. ceylanicum in mongrel dogs; Oesophagostomum apiostumum and Strongyloides fuelleborni in rhesus monkeys. Single oral doses of 30-60 mg/kg eliminated 94 to 99% of the total Necator parasites in 37-day-old non-patent infection, while single oral doses of 25 mg/kg expelled the entire worm burden in patient infection in hamsters. When incorporated in feed at the 0.01% level and administered ad lib. to hamsters at 20, 27 and 34 days postexposure for 5 days, the worm burdens were reduced 88 to 94%. N. dubius was completely eradicated by a single oral dose of 200 mg/kg while S. obvelata and H. nana were expelled at doses of 12.6 mg/kg and 50 mg/kg, respectively. A dose of 25 mg/kg in dogs produced 100% fecal egg reduction in hookworm and 99% in ascarid infections. The drug at 3 x 2.5 mg/kg administered at 4-hour intervals produced similar effects in mixed A. caninum and A. ceylanicum infections. Against natural infections of S. fulleborni and Oe. apiostumum in rhesus monkeys the drug showed 100% efficacy at a dosage of 60 mg/kg administered thrice at 12-hour intervals.

Production and cross-reactivity patterns of a panel of high affinity monoclonal antibodies to Vibrio cholerae O139 Bengal.

A series of monoclonal antibodies of different isotypes specific for Vibrio cholerae O139, the new pandemic strain of cholera, was produced. These mAbs reacted only with the reference strain (MO45) representing serovar O139 but did not react with any of the other reference strains representing serovars O1 to O140. Significantly, the mAbs did not agglutinate the R-cultures of V. cholerae (CA385, 20-93) which demonstrated the exceptional specificity of these mAbs and indicated that the mAbs recognized antigenic determinants unique for the O139 serovar. There was heterogeneity in the intensity of reactivity of the mAbs with strains of V. cholerae O139 isolated from diverse sources. Apart from 4H6, the other mAbs agglutinated all the O139 strains examined. 2D12 and 2F8 were the best mAbs based on the intensity of agglutination with all the O139 strains. Evaluation of 3A10 in comparison with a polyclonal anti-O139 antibody raised in rabbit using the slide agglutination format revealed that 3A10 fared as well as the polyclonal antibody for the laboratory identification of the O139 serovar. The acquisition of these mAbs provide reagents which would be very useful in the development of simple immunodiagnostic assays for the diagnosis of V. cholerae O139 infections.

Reaching out beyond the hills: HIV prevention among injecting drug users in Manipur, India.

Outreach interventions using ex-IDUs to inform and educate their peers about HIV/AIDS prevention measures have been found to be effective in the United States and other developed countries. While HIV/AIDS prevention programmes targeting IDUs have also been implemented in a number of developing countries, very little information is available on the process of implementation of these programmes. This paper attempts to document some of this knowledge by describing the implementation process of an outreach intervention targeting IDUs in a small town--Churachandpur--with high injection drug use and high HIV infection rates, in the north-eastern state of Manipur. The paper describes the barriers encountered in implementing the outreach and how these barriers were minimized. In conclusion, the paper makes the case for targeting outreach to the larger community before targeting the IDUs.

PIP: In the small town of Churanchandpur, Manipur, India, heroin injection began in the early 1980s. Over 80% of the injecting drug users (IDUs) in the state of Manipur are estimated to be HIV-positive. The implementation of an outreach intervention targeting IDUs is detailed. An advisory committee sought to create a supporting environment for the outreach by minimizing police harassment of IDUs. Church leaders were also provided information about the HIV/AIDS problem as were families of IDUs and the community. Outreach workers were recruited from the community and trained regarding HIV/AIDS epidemiology, prevention, antibody testing, and referral. The IDUs were approached in pairs by the outreach workers who delivered prevention messages: not to use drugs and injecting equipment; cleaning syringes with bleach; avoiding multiple sex partners; and using condoms. Within 1 year, 750 of the estimated 800 IDUs were reached and 3930 bleach kits and 4734 condoms were distributed. Referrals were made for medical problems (thrombophlebitis, abscess, and infections) to a team doctor or drop-in centers. Later, active IDUs were also recruited to help reach new IDUs. Dealers' homes were also visited to distribute risk reduction information and bleach kits. At the six drug treatment centers regular weekly visits were paid to provide prevention information. Weekly visits were made to the jail with a similar bid. A drug users' organization was formed which discussed health concerns faced by IDUs on a weekly basis. Two drop-in centers were also set up, where an average of 10-15 IDUs could come daily and discuss any problem with the field staff. Constraints on the outreach implementation included illegal drug use, low morale among the outreach workers, lack of understanding of the community and church, the cumbersome bureaucracy, the deteriorating political situation, no facilities for voluntary HIV testing and counseling, and the relapse of outreach workers into drug use.

Kanagawa phenomenon and serotypic pattern of Vibrio parahaemolyticus strains isolated from various sources in Calcutta.

A total of 135 strains of Vibrio parahaemolyticus isolated during the period 1976-77 from human gastroenteritis cases and various categories of environmental sources, e.g., crustaceans, fish and different water samples (pond, stored, open well and tap water) were tested for their Kanagawa phenomenon and serotypic pattern. Amongst the 80 human isolates tested, 69 strains (86.3%) were Kanagawa phenomenon positive, and 60 strains (75.0%) were serologically typable--the dominant serotype being 05:K15. Of the 25 isolates from various water sources 10(40.0%) were Kanagawa phenomenon positive, and 17(68.0%) were serologically typable and 4 (23.5%) of them belonged to serotype 05:K15. All the 30 strains isolated from crustaceans and fish were Kanagawa phenomenon negative and 22 (73.3%) of them were serologically typable, belonging to heterogeneous serotypes. The results of this study also indicate the possible role of water in the transmission of V. parahaemolyticus infection in Calcutta slums.

An epidemic of rotavirus diarrhoea in Manipur, India.

Recurrent epidemics of acute diarrhoeal disease in young children have occurred during the winter months in Manipur (India) for many years. During November 1979, children admitted to hospital for acute diarrhoea were investigated and, in addition to pathogenic Escherichia coli and Shigella rotovirus was detected by ELISA in a number of stool samples, especially of those less than one year old. The importance of this finding and the need for further study are discussed.

Necator americanus and Ancylostoma ceylanicum: development of protocols for dual infection in hamsters.

Two-day-old baby hamsters were infected initially with the infective larvae of hamster-adapted human hookworm, Necator americanus (NaL3). After a specified period they were again infected orally with infective larvae of Ancylostoma ceylanicum (AcL3). Three weeks after the second infection they were killed and the establishment of N. americanus and A. ceylanicum was assessed. The effect of different infection levels and exposure period of N. americanus on the concurrent establishment of A. ceylanicum was also examined. An infection with 50 NaL3 percutaneously, and 3 weeks later, a second infection with 50 AcL3 orally has produced reasonably equal number of hookworms (no statistical difference in the burden of N. americanus and A. ceylanicum) in the intestine of hamsters. Thus this protocol of dual infection was found suitable to develop two species of hookworms in hamsters for anthelmintic screening.

Site of resistance to Necator americanus in hamsters.

Resistance to the development of human hookworm, Necator americanus was examined in 3- to 6-week-old young adult hamsters. Only 3% of N. americanus infective third stage larvae (NaL3) reached maturity in the intestines of young adults as opposed to as many as 60% in 2-day-old baby hamsters. This seemingly effective resistance prevailing in young adults was investigated in some detail. The skin, the first site of contact for the invading NaL3, was bypassed during the infection process. Completely in vitro exsheathed NaL3 (ExNaL3) were used, and young adult hamsters were infected parenterally, by-passing the skin. Even after exsheathing the larvae artificially before infection and by-passing the skin, no improvement was seen in the development of N. americanus in the intestines of young adults. Higher infection doses also did not increase the worm burden. Some of the factors limiting the development of parasites in young adults were examined. N. americanus were monitored in lungs and intestines during various intervals after infection. Similar parasite burdens were apparent in lungs of baby as well as young adult hamsters. In the intestines, a significantly lower burden of N. americanus was seen during various intervals in young adults compared to the baby hamsters. Moreover, N. americanus were expelled soon after reaching the intestine. This comparative monitoring revealed the intestine as the seat of resistance against the establishment of N. americanus in young adult hamsters.

HIV-2 strikes injecting drug users (IDUs) in India.

Manipur, a north-eastern state of India bordering Myanmar, observed introduction of HIV-1 among fairly large number of IDUs in October 1989, followed by rapid spread within the next 6 months. HIV-2 in injectors was not present until recently, though it was detected from other parts of India in 1991. This communication reports for the first time presence of HIV-2 among young injectors of Manipur. All the HIV-2 infected IDUs were also found to be infected with HIV-1. HIV-2 has affected a large number of people in Africa through heterosexual transmission. It remains to be seen whether HIV-2 spreads rapidly also among the drug-injecting population of Manipur. Observation of the disease progression among HIV-2 infected IDUs will also be of interest.

PIP: HIV-1 was first detected in India in 1986. HIV-2 was first detected in the country in 1991 when paid blood donors and STD clinic attenders in north India tested seropositive for the virus. HIV-2 was later detected in Bombay and Goa. HIV-2 was also introduced in Madras and followed by an exponential increase in 1992 where heterosexual transmission was found to be responsible for the spread of the virus. 433 blood samples were collected and screened during the second quarter of 1994 from blood donors, injecting drug users (IDUs), and clinically suspected HIV disease cases admitted to the Regional Medical College (RMC) Hospital or treated at the outpatient department. 60.5% of IDUs tested positive for HIV-1, 6.6% were infected with both HIV-1 and HIV-2, and none were found to be infected exclusively with HIV-2. HIV-infected IDUs were aged 15-35 years and exclusively male. Most clinically suspected cases were young males attending the various departments of RMC with a history of long continued diarrhea, herpes zoster, extreme weight loss, miliary pulmonary tuberculosis, extrapulmonary tuberculosis, or pericardial effusion. Their histories suggested that many were IDUs, while a few only gave histories of unprotected sex with commercial sex workers. The report of a possible link between IDUs of Manipur and Madras suggests that HIV-2 may have come from Madras. The study of dual infection with both HIV-1 and HIV-2 among the IDUs may help in understanding the factors responsible for the efficient transmission of the two viruses. An extensive literature search found that HIV-2 among IDUs has previously been reported only from Spain approximately two years earlier.

Epidemic of herpes zoster following HIV epidemic in Manipur, India.

Since 1989, injecting drug use (IDU) related HIV infection has affected thousands of young adults in Manipur, a north eastern state of India bordering Myanmar following a similar kind of epidemic in adjoining countries like Thailand and Myanmar. During a clinical surveillance of a group of HIV positive IDUs for a natural history study at Manipur, herpes zoster (HZ) emerged as the most specific early HIV related illness (positive predictive value of 100%) in patients belonging to the age group of 12-45 years. Data collected from the dermatology departments of the two main hospitals of the state revealed that there had been an epidemic of HZ since 1990 (rate of 1990 being 11.3/1000 compared to 6.5/1000 in 1989, P value < 0.0001) among males of 12-45 years. The epidemic of HZ has been attributed to the preceding epidemic of IDU related HIV in the same age and gender group occurring 1 year earlier. HZ should be recognised as a marker condition similar to tuberculosis indicating the necessity of screening for HIV in regions where the dual problem of IDU and HIV exist in young adults.

Epidemiology of Vibrio cholerae O139 with special reference to intrafamilial transmission in Calcutta.

A total of 27 families of hospitalised patients (index case families) suffering from acute watery diarrhoea caused by Vibrio cholerae O139, and 14 neighbourhood families were bacteriologically screened for 4 consecutive days to determine the extent of V. cholerae O139 infection amongst healthy contacts and other suspected vehicles of transmission at the intrafamilial level. V. cholerae O139 was isolated from faeces of 14.6% of healthy contacts in index case families as compared to none in neighbourhood families (P = 0.002). The organism could be recovered from 3.7% of handwashings of contacts of index cases and also from stored drinking water (8.0%), open well water (28.6%), flies (3.8%) and pond water (25.0%) used by the index case families and none from neighbourhood families. The large number of asymptomatic infected persons indicate an epidemiological similarity to that of eltor cholera. The organisms may be carried on hands and may act as a potential source of infection to other inmates through contamination of stored drinking water, open wells etc. The results will be useful in formulating strategies for intervention of transmission of V. cholerae O139 at the community level.

An outbreak of acute diarrhoeal disease amongst tribal population in Tripura.

A massive outbreak of acute diarrhoeal diseases occurred during March-April, 1992 in the north district of Tripura. Investigation of the outbreak revealed Vibrio cholerae 01 biotype ElT or as the main etiologic agent in 50 per cent of patients. The outbreak which started amongst the tribal population might have spread due to prevailing illiteracy, poverty, low personal and domestic hygiene and vulnerable water sources (chhara water).

Clinical & bacteriological profiles of shigellosis in Calcutta before & after an epidemic (1984-87).

Patients below 5 yr of age, hospitalised for shigellosis over a period of four years (1984-87), were studied. During the epidemic of bacillary dysentery (1984) isolation of different Shigella spp. as well as Shigella dysenteriae type 1 was high. Decreased isolation of Sh. dysenteriae type 1 and increased isolation of Sh. flexneri was observed during post-epidemic years (1985-87). Isolation of different Shigella spp. was always above 25 per cent from patients with dysentery and greater than 7 per cent from those with watery diarrhoea during the post-epidemic years. Higher incidence of shigellosis was observed amongst older children (greater than 3 yr). Most of the shigellosis patients complained of blood and mucus in stools. Vomiting was common among shigellosis patients presenting with watery diarrhoea whereas fever was commonly seen in patients with both dysentery and watery diarrhoea. Most patients of shigellosis presenting with blood and mucus in stools had no dehydration.

A longitudinal study of diarrhoea among children in Calcutta communities.

PIP: A longitudinal study was conducted to determine the profile of diarrheal diseases in a group of 383 children below 5 years of age in 2 typical slums of Calcutta (India). The overall annual incidence of diarrheal illness in these children during the 1st year of the study was found to be 1.1/child. However, the incidence was higher (1.9/child) in children below 2 years of age and declined progressively with advancing age. Most (99.5%) of the diarrheal episodes were mild in nature and not a single child required hospitalization; about 53.4% children had no diarrheal symptoms. Enteropathogens identified in diarrheal stool samples from 13.7% of children included enteropathogenic Escherichia coli (5.8%), rotaviruses (5.6%), shigellae (3.5%), Salmonella spp, (1.0%), Entamoebae histolytica (0.9%), Giardia lamblia (0.4%), Vibrio cholerae (0.6%), and V. parahemolyticus (0.3%).^ieng