Corneal Alternations Induced by Topical Application of Benzalkonium Chloride in Rabbit

Benzalkonium chloride (BAC) is the most common preservative in ophthalmic preparations. Here, we investigated the corneal alternations in rabbits following exposure to BAC. Twenty-four adult male New Zealand albino rabbits were randomly divided into three groups. BAC at 0.01%, 0.05%, or 0.1% was applied twice daily to one eye each of rabbits for 4 days. The contralateral untreated eyes were used as control. Aqueous tear production and fluorescein staining scores of BAC-treated eyes were compared with those of controls. The structure of the central cornea was examined by in vivo confocal microscopy. Expression of mucin-5 subtype AC (MUC5AC) in conjunctiva was detected by immunostainig on cryosections. Corneal barrier function was assessed in terms of permeability to carboxy fluorescein (CF). The distribution and expression of ZO-1, a known marker of tight junction, and reorganization of the perijunctional actomyosin ring (PAMR) were examined by immunofluorescence analysis. Although there were no significant differences between control and BAC-treated eyes in Schirmer scores, corneal fluorescein scores and the number of conjunctival MUC5AC staining cells, in vivo confocal microscopy revealed significant epithelial and stromal defects in all BAC-treated corneas. Moreover, BAC at 0.1% resulted in significant increases in central corneal thickness and endothelial CF permeability, compared with those in control eyes, and endothelial cell damage with dislocation of ZO-1 and disruption of PAMR. Topical application of BAC can quickly impair the whole cornea without occurrence of dry eye. A high concentration of BAC breaks down the barrier integrity of corneal endothelium, concomitant with the disruption of PAMR and remodeling of apical junctional complex in vivo

Mapping Helminth Co-Infection and Co-Intensity: Geostatistical Prediction in Ghana

Urinary schistosomiasis and hookworm infections cause considerable morbidity in school age children in West Africa. Severe morbidity is predominantly observed in individuals infected with both parasite types and, in particular, with heavy infections. We investigated for the first time the distribution of S. haematobium and hookworm co-infections and distribution of co-intensity of these parasites in Ghana. Bayesian geostatistical models were developed to generate a national co-infection map and national intensity maps for each parasite, using data on S. haematobium and hookworm prevalence and egg concentration (expressed as eggs per 10 mL of urine for S. haematobium and expressed as eggs per gram of faeces for hookworm), collected during a pre-intervention baseline survey in Ghana, 2008. In contrast with previous findings from the East Africa region, we found that both S. haematobium and hookworm infections are highly focal, resulting in small, localized clusters of co-infection and areas of high co-intensity. Overlaying on a single map the co-infection and the intensity of multiple parasite infections allows identification of areas where parasite environmental contamination and morbidity are at its highest, while providing an evidence base for the assessment of the progress of successive rounds of mass drug administration (MDA) in integrated parasitic disease control programs

Mapping the Risk of Anaemia in Preschool-Age Children: The Contribution of Malnutrition, Malaria, and Helminth Infections in West Africa

Ricardo Soares Magalhães and colleagues used national cross-sectional household-based demographic health surveys to map the distribution of anemia risk in preschool children in Burkina Faso, Ghana, and Mali

Cross-sectional and prospective associations between sleep, screen time, active school travel, sports/exercise participation and physical activity in children and adolescents

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Binary systems and their nuclear explosions

Peer ReviewedPreprin

Descriptive Epidemiology of Chronic Hypertension, Gestational Hypertension, and Preeclampsia in New York State, 1995–2004

We examined social, demographic, and behavioral predictors of specific forms of hypertensive disorders in pregnancy in New York State. Administrative data on 2.3 million births over the period 1995–2004 were available for New York State, USA, with linkage to birth certificate data for New York City (964,071 births). ICD-9 hospital discharge diagnosis codes were used to assign hypertensive disorders hierarchically as chronic hypertension, chronic hypertension with superimposed preeclampsia, preeclampsia (eclampsia/severe or mild), or gestational hypertension. Sociodemographic and behavioral predictors of these outcomes were examined separately for upstate New York and New York City by calculating adjusted odds ratios. The most commonly diagnosed conditions were preeclampsia (2.57 % of upstate New York births, 3.68 % of New York City births) and gestational hypertension (2.46 % of upstate births, 1.42 % of New York City births). Chronic hypertension was much rarer. Relative to non-Hispanic Whites, Hispanics in New York City and Black women in all regions had markedly increased risks for all hypertensive disorders, whereas Asian women were at consistently decreased risk. Pregnancy-associated conditions decreased markedly with parity and modestly among smokers. A strong positive association was found between pre-pregnancy weight and risk of hypertensive disorders, with slightly weaker associations among Blacks and stronger associations among Asians. While patterns of chronic and pregnancy-induced hypertensive disorders differed, the predictors of gestational hypertension and both mild and severe preeclampsia were similar to one another. The increased risk for Black and some Hispanic women warrants clinical consideration, and the markedly increased risk with greater pre-pregnancy weight suggests an opportunity for primary prevention among all ethnic groups