Study - Minimal erythema response (MED) to solar simulated irradiation in normal Indian skin

BACKGROUND: Phototesting is an essential tool in the investigation of photodermatoses. AIMS: The main aim was to study the cutaneous response to UVR in terms of minimal erythema dose (MED) to both UVA and UVB in normal Indian subjects with a solar simulator and to study the relationship of skin type to MED. METHODS: One hundred healthy volunteers not on any medication and without any history of photodermatoses were phototested using a solar simulator with whole spectrum irradiation (UVA, UVB and visible light) and only visible and UVA radiation. The tested areas were marked with gentian violet and readings were taken after 24 hrs. RESULTS: Of the 100 volunteers, 48% were males and 52% were females, with a mean age of 36.6 \ub1 11.6 yrs. The most common skin type among Indians was type 5 (46%) followed by type 4 (41%). The mean MED for UVB was 61.5 \ub1 17.25J/cm2. The MED for UVA could not be determined as none of the patients showed any erythema after irradiation for 45 minutes. CONCLUSIONS: As the MED is found to be low in idiopathic acquired photodermatoses, the MED in the normal population could serve as a baseline data in the investigation

Indoor Social Networks in a South African Township: Potential Contribution of Location to Tuberculosis Transmission

CITATION: Wood, R. et al. 2012. Indoor social networks in a South African township : potential contribution of location to tuberculosis transmission. PLoS ONE, 7(6): e39246, doi:10.1371/journal.pone.0039246.The original publication is available at http://journals.plos.org/plosoneBackground We hypothesized that in South Africa, with a generalized tuberculosis (TB) epidemic, TB infection is predominantly acquired indoors and transmission potential is determined by the number and duration of social contacts made in locations that are conducive to TB transmission. We therefore quantified time spent and contacts met in indoor locations and public transport by residents of a South African township with a very high TB burden. Methods A diary-based community social mixing survey was performed in 2010. Randomly selected participants (n = 571) prospectively recorded numbers of contacts and time spent in specified locations over 24-hour periods. To better characterize age-related social networks, participants were stratified into ten 5-year age strata and locations were classified into 11 types. Results Five location types (own-household, other-households, transport, crèche/school, and work) contributed 97.2% of total indoor time and 80.4% of total indoor contacts. Median time spent indoors was 19.1 hours/day (IQR:14.3–22.7), which was consistent across age strata. Median daily contacts increased from 16 (IQR:9–40) in 0–4 year-olds to 40 (IQR:18–60) in 15–19 year-olds and declined to 18 (IQR:10–41) in ≥45 year-olds. Mean daily own-household contacts was 8.8 (95%CI:8.2–9.4), which decreased with increasing age. Mean crèche/school contacts increased from 6.2/day (95%CI:2.7–9.7) in 0–4 year-olds to 28.1/day (95%CI:8.1–48.1) in 15–19 year-olds. Mean transport contacts increased from 4.9/day (95%CI:1.6–8.2) in 0–4 year-olds to 25.5/day (95%CI:12.1–38.9) in 25–29 year-olds. Conclusions A limited number of location types contributed the majority of indoor social contacts in this community. Increasing numbers of social contacts occurred throughout childhood, adolescence, and young adulthood, predominantly in school and public transport. This rapid increase in non-home socialization parallels the increasing TB infection rates during childhood and young adulthood reported in this community. Further studies of the environmental conditions in schools and public transport, as potentially important locations for ongoing TB infection, are indicated.http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0039246Publisher's versio

An overview of geospatial methods used in unintentional injury epidemiology

BACKGROUND: Injuries are a leading cause of death and disability around the world. Injury incidence is often associated with socio-economic and physical environmental factors. The application of geospatial methods has been recognised as important to gain greater understanding of the complex nature of injury and the associated diverse range of geographically-diverse risk factors. Therefore, the aim of this paper is to provide an overview of geospatial methods applied in unintentional injury epidemiological studies. METHODS: Nine electronic databases were searched for papers published in 2000-2015, inclusive. Included were papers reporting unintentional injuries using geospatial methods for one or more categories of spatial epidemiological methods (mapping; clustering/cluster detection; and ecological analysis). Results describe the included injury cause categories, types of data and details relating to the applied geospatial methods. RESULTS: From over 6,000 articles, 67 studies met all inclusion criteria. The major categories of injury data reported with geospatial methods were road traffic (n = 36), falls (n = 11), burns (n = 9), drowning (n = 4), and others (n = 7). Grouped by categories, mapping was the most frequently used method, with 62 (93%) studies applying this approach independently or in conjunction with other geospatial methods. Clustering/cluster detection methods were less common, applied in 27 (40%) studies. Three studies (4%) applied spatial regression methods (one study using a conditional autoregressive model and two studies using geographically weighted regression) to examine the relationship between injury incidence (drowning, road deaths) with aggregated data in relation to explanatory factors (socio-economic and environmental). CONCLUSION: The number of studies using geospatial methods to investigate unintentional injuries has increased over recent years. While the majority of studies have focused on road traffic injuries, other injury cause categories, particularly falls and burns, have also demonstrated the application of these methods. Geospatial investigations of injury have largely been limited to mapping of data to visualise spatial structures. Use of more sophisticated approaches will help to understand a broader range of spatial risk factors, which remain under-explored when using traditional epidemiological approaches

Extensive larva migrans

Larva migrans is characterized by tortuous migratory lesions of the skin caused by larvae of nematodes. A 26-year-old fisherman presented to us with complaints of an itchy eruption on his back and arms of two months\u2032 duration. Clinical examination revealed multiple wavy serpentine tracts and fork like lesions with a raised absolute eosinophil count of 3800 cells/cmm. Biopsy was inconclusive. This case is reported to highlight the extensive involvement by larva migrans

Lichen amyloidosus: A study of clinical, histopathologic and immunofluorescence findings in 30 cases

En este artículo se presentan 3 propuestas de investigación que tienden a vincular el fenómeno tecnológico-cultural-social del big data con la teoría de los sistemas sociales de Niklas Luhmann, en un nivel programático. Específicamente, proponemos: (1) explorar la tematización del big data y su relación con la sociedad y la ciencia por parte de distintos sistemas sociales; (2) desarrollar e integrar herramientas y técnicas analíticas de big data en un diseño metodológico empírico coherente con los postulados de la teoría; y (3) llevar adelante un análisis epistemológico de los reclamos cognitivos en la retórica del big data, por la vía de un análisis comparativo con “constructivismo operativo” propuesto por Luhmann como la epistemología de los sistemas sociales.This paper proposes (at a programmatic level) 3 research lines that tend to link the technological-cultural-social phenomenon of big data with Niklas Luhmann’s Social Systems Theory. We propose: (1) to explore the thematization of big data and its relation to society and science by different social systems; (2) to develop and integrate big data analytical tools and techniques in an empirical methodological design consistent with the postulates of the theory; and (3) to carry out an epistemological analysis of cognitive claims in the rhetoric of big data, through a comparative analysis with "operational constructivism" proposed by Luhmann as the epistemology of social systems.Este artigo apresenta três propostas de pesquisa que tendem a vincular o fenômeno tecnológico-cultural-social do big data com a teoria dos sistemas sociais de Niklas Luhmann, em um nível programático. Especificamente, propomos: (1) explorar a tematização do big data e sua relação com a sociedade e a ciência por diferentes sistemas sociais; (2) desenvolver e integrar ferramentas e técnicas analíticas de big data em um desenho metodológico empírico consistente com os postulados da teoria; e (3) realizar uma análise epistemológica das reivindicações cognitivas na retórica do big data, através de uma análise comparativa com o "construtivismo operacional" proposto por Luhmann como a epistemologia dos sistemas sociais.Facultad de Trabajo Socia