Investigation into postoperative endophthalmitis and lessons learned

PURPOSE: To describe an approach to the investigation of a series of endophthalmitis cases to determine whether there was a true outbreak. SETTING: Outpatient facility, Sunderland, England. METHODS: Different approaches to statistical analysis of the probability of infrequent events being due to chance occurrence are described. Potential factors leading to an outbreak were reviewed. RESULTS: Bayesian statistical analysis was shown to be appropriate in the determination of an endophthalmitis outbreak. The only factor found to account for the outbreak was the operating surgeon's recent abandonment of subconjunctival antibiotic prophylaxis. This decision was based on the absence of good evidence that subconjunctival antibiotic injection is effective in prophylaxis. These endophthalmitis cases demonstrate that the absence of evidence for effect is not the same as there being no effect. CONCLUSIONS: Bayesian statistical analysis has a place in determining whether an outbreak has occurred. Withdrawing treatment simply on the basis of a lack of good evidence can lead to undesirable outcomes.     

Speciation of arsenic in biological samples

Speciation of arsenicals in biological samples is an essential tool to gain insight into its distribution in tissues and its species-specific toxicity to target organs. Biological samples (urine, hair, fingernail) examined in the present study were collected from 41 people of West Bengal, India, who were drinking arsenic (As)-contaminated water, whereas 25 blood and urine samples were collected from a population who stopped drinking As contaminated water 2 years before the blood collection. Speciation of arsenicals in urine, water-methanol extract of freeze-dried red blood cells (RBCs), trichloroacetic acid treated plasma, and water extract of hair and fingernail was carried out by high-performance liquid chromatography (HPLC)-inductively coupled argon plasma mass spectrometry (ICP MS). Urine contained arsenobetaine (AsB, 1.0%), arsenite (iAs(III), 11.3), arsenate (iAs(V), 10.1), monomethylarsonous acid (MMA(III), 6.6), monomethylarsonic acid (MMA(V), 10.5), dimethylarsinous acid (DMA(III), 13.0), and dimethylarsinic acid (DMA(V), 47.5); fingernail contained iAs(III) (62.4%), iAs(V) (20.2), MMA(V) (5.7), DMA(III) (8.9), and DMA(V) (2.8); hair contained iAs(III) (58.9%), iAs(V) (34.8), MMA(V) (2.9), and DMA(V) (3.4); RBCs contained AsB (22.5%) and DMA(V) (77.5); and blood plasma contained AsB (16.7%), iAs(III) (21.1), MMA(V) (27.1), and DMA(V) (35.1). MMA(III), DMA(III), and iAs(V) were not found in any plasma and RBCs samples, but urine contained all of them. Arsenic in urine, fingernails, and hair are positively correlated with water As, suggesting that any of these measurements could be considered as a biomarker to As exposure. Status of urine and exogenous contamination of hair urgently need speciation of As in these samples, but speciation of As in nail is related to its total As (tAs) concentration. Therefore, total As concentrations of nails could be considered as biomarker to As exposure in the endemic areas.     

Antiulcer activity of methanol fraction of Barleria lupulina Lindl. in animal models

The objective of the present study was to evaluate the gastric cytoprotective activity of the methanol extract of aerial parts of the plant Barleria lupulina Lindl (Acanthaceae) in albino rats using various models of ulcers such as drug induced ulcers, restraint ulcers, duodenal ulcers and pylorus ligated ulcers. The effect of the extract on gastric secretion and lipid peroxidation (thiobarbituric acid reacting substances TBARS) was also studied in rats. The extract at the tested dose of 200 mg/kg significantly reduced the volume of gastric juice, total acidity and the ulcer index in pylorus ligated rats. It also afforded significant protection against alcohol and indomethacin induced ulcer as well as stress induced ulceration. TBARS in the stomach of indomethacin treated rats was also reduced. In addition, it gave protection against duodenal ulcers. The study suggests that the methanol extract of aerial parts of Barleria lupulina Lindl. has a protective effect against experimental gastric and duodenal ulcers.     

Evaluation of the anticarcinogenic activity of Swertia chirata Buch.Ham, an Indian medicinal plant, on DMBA-induced mouse skin carcinogenesis model

Considerable attention has been focused on plants which are sources of natural anti-oxidant compounds, because most of them have a modulatory role on physiological functions and biotransformation reactions involved in the detoxification process. Such compounds are likely to afford protection from cytotoxic, genotoxic and metabolic actions of environmental toxicant thereby reducing the risk for cancer. The present study reports the anticarcinogenic activity of Swertia chirata Buch.Ham, an Indian medicinal plant. All the four detoxification enzymes studied viz, GST, GPx, SOD and CAT were found to be activated in different degrees following treatment with infusion of Swertia chirata, its crude extract and a purified 'Amarogentin' rich extract. The activation of the enzymes was accompanied by significant reduction in lipid peroxidation and inhibition of incidence as well as multiplicity of Dimethylbenz(a)anthracene (DMBA) induced papillomas. The effect of S.chirata on apoptosis and cell proliferation was also studied in mice skin exposed to DMBA. Both the crude and purified extracts significantly inhibited cell proliferation and induced apoptosis. This is the fi rst report of its kind and the observation suggests the chemopreventive potential of Swertia chirata.     

Motor performance as a function of verbal, nonverbal interference and handedness

The effect of verbal and nonverbal interference on finger-tapping performance was analyzed in self-classified left (n = 15) and right-handed (n = 15) subjects. Data were analyzed with a Group (left hander, right hander) x Condition (with interference [verbal, nonverbal], without interference) x Hand (left hand, right hand) mixed factorial ANOVA with repeated measures in Condition and Hand factors. Verbal as well as nonverbal interference conditions, as compared to non-interference conditions, significantly impaired finger-tapping performance of the left relative to right handers.     

Efficient priming of simian/human immunodeficiency virus (SHIV)-specific T-cell responses with DNA encoding hybrid SHIV/hepatitis B surface antigen particles

Recent efforts to design an human immunodeficiency virus type 1 (HIV-1) vaccine candidate have focused on means of eliciting anti-viral T-cell responses. We tried to improve the immunogenicity of DNA vaccines by designing hybrid DNA constructs encoding hepatitis B surface antigen (HBsAg) fused to antigenic domains of simian/human immunodeficiency virus (SHIV 89.6P). Immunisation with hybrid DNA induced both effector and long-lasting precursor T-cells. Following boosting with a recombinant modified vaccinia Ankara (rMVA) producing full-length SIV and HIV antigens, it appeared that priming with hybrid DNA had increased virus-specific T-cell responses in terms of both the number of virus-specific IFN-gamma-secreting T-cells and virus-specific lymphoproliferation. After intrarectal challenge with SHIV 89.6P, immunised animals demonstrated early control of SHIV 89.6P replication and stable CD4+ T-cell counts.     

Carcinogenic effect of nicotine on normal mammary ductal epithelial cells and the protective role of beta-carotene

A number of carcinogens like polycyclic hydrocarbons and aromatic amines have been incriminated to induce mammary carcinomas in vitro and in vivo. Studies have supported an inter-relationship between tobacco consumption and breast cancer. Because nicotine is the major alkaloid present in tobacco this study was conducted to find the direct in vitro effect of nicotine on normal mammary ductal epithelial cells. It was seen in the present work that nicotine causes a statistically significant increase in the proliferative rate and ER (estrogen receptor) expression as compared to the control group. This change was more pronounced with a lower concentration of nicotine (650 microg/ml). Colony efficiency also showed a similar trend. Beta carotene was added in the present work to study its anti oxidant effect on nicotine induced changes. Beta carotene significantly decreased the proliferation rate induced by 650 microg/ml nicotine. It also prevented the cytotoxic effect of higher dose of nicotine, however, it failed to alter significantly the ER expression induced by lower concentration of nicotine though it showed decreasing trend.