Indoor air quality of schools in Alexandria city

Poor air quality in schools can affect children's desire and ability to concentrate and learn and may lead to increased rate of absenteeism. This study was carried out with the aim of characterizing and measuring indoor air quality in school buildings, measuring ventilation status and studying the impact of design and environmental parameters on some measured pollutant levels. The study was carried out in some primary schools of Alexandria City. All ventilation rate levels exceeded the ASHRAE standard of 15 cfm/pupil except for a few cases. Badly located and small window area led to air stagnation and low ventilation rates. Levels of TSP greatly exceeded a suggested daily guideline of 150 mug/m3. The highest average levels of TSP were found inside classrooms surrounded by unpaved playground and located near semi rural, commercial and heavy traffic areas, while lowest levels were in classrooms located next to residential areas. The average total bacteria were highest in winter. There was also a slight increase in respiratory symptoms and signs in winter. There was a significant positive correlation between average total, pathogenic and non-pathogenic bacteria with average TSP Levels, indoor CO2 levels and relative humidity; while a significant negative correlation was observed with ventilation rate and class volume occupied. The average attack rate of respiratory conditions was 1.96 episode per child. Running nose was the highest frequent symptom. Students of first grade had an incidence rate higher than that among fifth grade students

CD1, CD4, CD8 and CD56: as possible tools for early cancer detection and staging part I

Antigen presenting, direct killing and chemotactic responsiveness activity of tumor infiltrating immunocompetent cells were studied in 58 patients with early oral premalignant and malignant spectrum of squamous epithelial proliferation. The cells of Langerhans [CD1 or T6], T lymphocytes bearing suppressor/cytotoxic [CD8] or helper/inducer [CD4], natural killing [NK] cells [CD56] were imaged by the indirect immunoperoxidase method, as to the best of their knowledge, no enough data about their localization in the oral premalignant lesions up till present date. Lc lost their dendritic processes through higher stages of malignancy whereas, high CD4/CD8 and CD56 cells count were noticed at the early and late pre-neoplastic stages. Few of these immunocompetent cells were detected for the first time [to the best of the knowledge] infiltrating the dysplastic oral mucosa. The variable shapes of NK cells while, acting on the neoplastic cells were assessed, also for the first time in the present analysis. The enigma of transformation towards the end of neoplasia stasis, or even regression present in some patients could be influenced with the immunocompetent cells as well as other factors. Marked local immunocytodeficiency were observed in most of the analyzed cells except for CD8 and NK cells through the series of these diseases. In order to achieve an effective adjuvant immunotherapy a thorough analysis of the immune situation is a pre-request. According to the present results, the abovementioned markers have an important role in cancer assessment, prognosis, prevention and treatment