Suction drain tip culture in orthopaedic surgery: a prospective study of 214 clean operations

We conducted a prospective cohort study in order to determine whether suction drain specimen cultures from orthopaedic surgery predicted an early wound infection. We included 218 consecutive clean orthopaedic operations requiring drains in one unit over a period of 1 year. The suction drain tip, drain fluid and wound discharge specimens were cultured, and the surgical wound was followed up for 3 months. There were six deep and two superficial wound infections. Wound infection was significantly related to positive suction tip culture but not to positive drain fluid culture. Following our methodology for culture, a positive drain tip culture predicts wound infection in 50% and a negative culture virtually excludes the possibility of a deep infection.

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Résumé Nous avons conduit prospectivement une étude de cohorte pour déterminer si les cultures dun échantillon du produit de drainage aspiratif peuvent être prédictives précocément dune infection. Nous avons inclus 218 opérations orthopédiques propres consécutives, exigeant un drainage, sur une période dune année. Lextrémité du drain, le liquide de drainage, et des prélévements opératoires étaient mis en culture et la cicatrice chirurgicale surveillée pendant 3 mois. Il y avaient 2 infections superficielles et 6 pronfondes. Linfection était en rapport significatif avec la culture du drain mais sans rapport avec celle du liquide de drainage. En suivant notre méthodologie, une culture positive de lextrémité du drain prédit linfection de la blessure dans 50% et une culture négative exclut la possibilité dune infection profonde.

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First presented at the Tenth International Scientific Meeting of the European Society of Chemotherapy, Vienna, 30 June 2003.     

Exposure assessment for respirable particulates associated with household fuel use in rural districts of Andhra Pradesh, India

Indoor air pollution associated with combustion of solid fuels seems to be a major contributor to the national burden of disease in India, but relatively few quantitative exposure assessment studies are available. This study quantified the daily average concentrations of respirable particulates (50% cut-off at 4 microm) in 412 rural homes selected through stratified random sampling from three districts of Andhra Pradesh, India and recorded time activity data from 1400 individuals to reconstruct 24-h average exposures. The mean 24-h average concentrations ranged from 73 to 732 microg/m(3) in gas- versus solid fuel-using households, respectively. Concentrations were significantly correlated with fuel type, kitchen type, and fuel quantity. The mean 24-h average exposures ranged from 80 to 573 microg/m(3). Among solid fuel users, the mean 24-h average exposures were the highest for women cooks and were significantly different from men and children. Among women, exposures were the highest in the age group of 15-40 years (most likely to be involved in cooking or helping in cooking), while among men, exposures were highest in the age group of 65-80 years (most likely to be indoors). The data are being used to develop a model to predict quantitative categories of population exposure based on survey information on housing and fuel characteristics. This would facilitate the development of a regional exposure database and enable better estimation of health risks.     

Synergistic effect of methanol extract of Abies webbiana leaves on sleeping time induced by standard sedatives in mice and anti-inflammatory activity of extracts in rats

During the determination of LD50 values of extracts of Abies webbiana, it was observed that the methanol extract (MEAW) produces sedation of animals. This led to investigation of the effect of MEAW on sleeping time in mice. When various doses of the methanol extract (100, 150, and 200 mg/kg body weight) were administered alone, no hypnotic activity was observed. However, these exhibited significant synergistic effects (P < 0.001) at those dose levels in mice when administered prior to the administration of standard sedatives (pentobarbitone sodium: 50 mg/kg and diazepam: 6 mg/kg, respectively). In addition anti-inflammatory effects of methanol, chloroform, and petroleum ether extracts of Abies webbiana leaves in rats were performed to assess scientific validity of the medicinal claim of Indian folk medicine. The effects of leaf extracts (methanol, chloroform, and petroleum ether) against inflammation were studied by carrageenan-induced paw edema model in rats. The methanol extract (400 mg/kg p.o.) of leaves of Abies webbiana showed the best significant anti-inflammatory activity as compared to that of diclofenac sodium (150 mg/kg p.o.). The LD50 values of methanol, chloroform, and petroleum ether extracts were found to be 986, 1387, and > 3200 mg/kg, respectively. Thus, the therapeutic index of methanol extract may be favorable to open a new vista on combination therapy of hypnotics and may also against inflammation.     

Morphologic effects of subtoxic neonatal chlorpyrifos exposure in developing rat brain: regionally selective alterations in neurons and glia

The widely used organophosphate insecticide, chlorpyrifos (CPF), elicits neurobehavioral teratogenesis with exposure windows ranging from the embryonic neural tube stage through postnatal development. To explore the morphologic changes occurring in late-stage exposure, newborn rats were given 5 mg/kg of CPF s.c. daily on postnatal days (PN) 11-14, a regimen that is devoid of systemic toxicity, but that elicits long-term cognitive impairment. On PN15 and 20, we examined the septal nucleus, striatum and somatosensory cortex. Across all three regions, CPF elicited a significant decrease in the number of glial cells. Superimposed on this basic pattern, there were region-specific alterations in the number and type of neurons, and neuronal perikaryal dimensions. In the septal nucleus, the CPF group exhibited an increase in the number of neurons on PN20, representing a delay in the normal maturational decline; there was a parallel decrease in the glial/neuronal ratio. In the striatum, the number of neurons per unit area was reduced in the CPF group, accompanied by perikaryal hypertrophy, as evidenced by an increase in the average neuronal cell diameter. In the somatosensory cortex, the distribution of cell sizes indicated a decrease in the proportion of small, nonpyramidal cells. Thus, there are subtle morphological changes in the juvenile rat brain after neonatal CPF exposure that are detectable with quantitative analysis and that correlate with later emergence of behavioral alterations. Furthermore, the current findings support the hypothesis that CPF interferes with gliogenesis, a relatively late event in brain development; accordingly, the vulnerable period for adverse effects of CPF is likely to extend into childhood or adolescence.     

Formulation and biopharmaceutical evaluation of osmotic matrix tablets of diclofenac sodium

The objective of our study was to prepare and evaluate osmotic matrix (OM) tablets of diclofenac sodium (DS). In vitro studies were done on USPXXIV dissolution apparatus II in different release medium. Surface characteristics of coating films and osmotic contribution of OM tablets also were studied. In vivo evaluation was carried out in 6 healthy human volunteers using HPLC method to assay plasma samples, and the results were compared with the performance of fabricated matrix and two commercial tablets of DS. Through in vitro drug release kinetics, using regression coefficient analysis and Peppas equation, different pharmacokinetic parameters and relative bioavailability were determined. OM tablets were found to provide more prolonged and controlled therapeutic plasma DS levels and also showed improved bioavailability in comparison to fabricated matrix and commercial tablets studied.     

Development and in vitro evaluations of gelatin A microspheres of ketorolac tromethamine for intranasal administration

Gelatin A microspheres (MS) of ketorolac tromethamine (KT) for intranasal systemic delivery were developed with the aim to avoid gastro-intestinal complications, to improve patient compliance, to use as an alternative therapy to conventional dosage forms, to achieve controlled blood level profiles, and to obtain improved therapeutic efficacy in the treatment of postoperative pain and migraine. Gelatin A microspheres were prepared using the emulsification-crosslinking technique. The drug was dispersed in polymer gelatin and formulated into a w/o emulsion with liquid paraffin, using glutaraldehyde as a crosslinking agent. The formulation variables were drug loading and the concentrations of polymer (gelatin), co-polymer (chitosan) and the crosslinking agent. All the prepared microspheres were evaluated for physical characteristics, such as particle size, incorporation efficiency, swelling ability, in vitro bioadhesion on rabbit small intestine and in vitro drug release characteristics in pH 6.6 phosphate buffer. All the microspheres showed good bioadhesive properties. Gelatin A and chitosan concentrations, percentage of the crosslinking agent and also the drug loading affected significantly the rate and extent of drug release. The data indicated that the KT release followed Higuchi's matrix model.     

Development and biopharmaceutical evaluation of osmotic pump tablets for controlled delivery of diclofenac sodium

Based on the principles of an elementary osmotic pump (OP), OP tablets were designed and evaluated with the aim to deliver diclofenac sodium (DS) in a controlled manner. In vitro evaluation was done in various release media and kinetics was evaluated using the regression coefficient analysis. Effects of orifice size, coating membrane type, coating thickness, static and stirred conditions and pH variation were studied. In vivo evaluation was performed on six healthy human volunteers and various pharmacokinetic parameters (c(max), t(max), AUC(0-24), MRT) and relative bioavailability were calculated. The results were compared with the performance of two commercial tablets of DS. The drug release from OP tablets was dependent on the type and thickness of the coating membrane, but was independent of the orifice size and static and stirred conditions of the release medium. The OP tablets provided a prolonged and controlled DS release compared to commercial sustained-release and conventional tablets of DS.     

Transdermal iontophoresis of insulin. Part 1: A study on the issues associated with the use of platinum electrodes on rat skin

We have studied the issues associated with the use of platinum electrodes for transdermal iontophoretic delivery of peptides, using insulin as a model peptide. Insulin permeation was studied using full-thickness rat skin by varying the donor solution pH as a function of electrode polarity. The stability of insulin under the iontophoretic conditions was studied using TLC, SDS-polyacrylamide gel electrophoresis and HPLC. Large pH shifts were observed during anodal iontophoresis (AI), when the donor solution pH was above the isoelectric point of insulin and in cathodal iontophoresis (CI), when the donor solution pH was below the isoelectric point of insulin. The direction and magnitude of electroosmotic flow was influenced by pH of the donor solution and the electrode polarity. On the other hand, the buffer used to maintain the pH governed the contribution of electrorepulsion to the overall transport of insulin. Electrochemical degradation of insulin was significant during AI at pH 7.4. Among the pH investigated, AI of insulin at pH 3.6 and CI at pH 8.35 were better, as the pH shift was relatively less and electrochemically more stable during iontophoresis as compared with other pH. In summary, the pH shift caused by platinum electrodes had a significant influence on the permeation and stability of insulin.     

Tobacco consumption in India: a new look using data from the National Sample Survey

This paper examines the various issues surrounding tobacco use in India, using National Sample Survey and other data. The study demonstrates that 150 million Indians used tobacco in 1998 and that during the 1990's, the prevalence increased for both rural and urban areas, as well as in both sexes and in all age groups. Such large numbers have staggering implications for the country's economy, health outcomes and resources, and the magnitude of tobacco control challenges. Bidis hand-rolled cigarettes remain the most commonly used form of tobacco. However, major differences in rates and types of tobacco used were seen among various sex, age, economic and social class groups, suggesting that public health efforts to reduce consumption will require focused initiatives to target various populations and products.