4,986 research outputs found

    The Nutritional Status of Elites in India, Kenya, and Zambia: An appropriate guide for developing reference standards for undernutrition?

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    Assessments of undernutrition are typically based on comparisons between anthropometric indicators of children and a reference standard from the US. Due to a number of problems associated with this reference standard, WHO is currently engaged in generating a new international reference standard for child growth based on well­to­do populations in a sample of poor and rich countries. The focus on socioeconomic elites is to ensure that the measured growth reflects their genetic potential (and not according their constrained environment). Based on an analysis of the Demographic and Health Surveys from Kenya, India, and Zambia, we identify a number of problems associated with using socioeconomic elites as representative of the genetic potential of a population. First, there are several, non­overlapping ways to identify elites. Second, the anthropometric status of elites appears to depend to a considerable degree on the nutrition and health status of non­elites. Third, there is a danger that the elites are not a random sample of the growth potential of the population. And lastly, it appears that the nutritional status of elites differs substantially between the three countries so that it is unclear how one can combine them to generate one international reference standard

    Detection of HPV in cancerous and non-cancerous esophageal tissues from Turkmen-Sahra, Iran

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    The aim of this study were to assess the presence of HPV esophageal infection among Iranian Turkmen who live in an area located in the cancer belt in Asia. The specimens derived from 120 patients previously diagnosed for Squamous Cell Carcinoma (SCC) non-cancerous tissue derived from esophagus. All specimens were examined for the presence of HPV DNA PCR was utilized to amplify a 150 bp segment of HPV L1 gene using the consensus primers. The amplified region was subsequently sequenced to identify the HPV genotypes. The HPV DNA was detected in 49.4% of patients with SCC, and 58% of non-cancerous tissue of esophagus. The positive samples included HPV-16 (46.6%), HPV-6 (24.6%), HPV-66 (8.2%), HPV-52 (4.1%), HPV-18 (2.7%); 14% of cases were positive for more than one type of HPV. The results confirm the presence of HPV in both esophageal cancerous and non-cancerous tissues. These results imply two different interpretations: 1) Due to non-significant difference between the rate of HPV positive in cancerous and non-cancerous tissues, HPV has no important role in esophageal cancers, which is less probable. 2). Because of a highly incidence of esophageal cancer in Turkmen-Sahra region, the HPV is a possible etiologic agent in esophageal carcinogenesis, most probably acting synergistically with physical, chemical, and/or nutritional factors that have previously been found to be related to this malignancy in Turkmen-Sahra. © 2006 Academic Journals Inc., USA

    Potential mutations associated with occult hepatitis B virus status

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    Context: Occult hepatitis B virus (HBV) status (OHBS) is simply defined as the presence of HBV DNA in the liver (with or without detectable HBV DNA in the serum), in the absence of serum HBV surface antigen (HBsAg). Importance of OHBS is mostly clinical, related to its possible role in spreading through blood transfusion and liver transplantation; causing classic forms of HBV. Mechanisms underlying this entity are poorly defined. Several possibilities have been suggested, with major classification into two groups: defective host immune response and viral replication activity through mutations of HBV DNA sequence. Mutations are extensively investigated in all four overlapping open reading frames (ORFs) of HBV genome, to define their possible role in the pathogenesis of OHBS. Some of these mutations like S-escape mutants could not be detected by the routine available assays, making them difficult to diagnosis. Therefore, trying to detect this covert condition could be more helpful for defining better preventive and therapeutic strategies. Evidence Acquisition: In the present study we provided an in-depth review of the most important new data available on different mutations in HBV genome of patients with OHBS, which may play a role in the pathogenesis of OHBS. The data were collected through reviewing the full-text articles, identified by the PubMed search, using the following keywords and their different combinations: occult hepatitis B, HBV genome, "a" determinant, HBV open reading frames, S mutations, X mutations, P mutations and C mutations. Results: Variants within the major hydrophilic region (MHR) of the HBsAg, deletions in the pre-S1region, codon stop in the S open reading frames (ORF), sporadic non common mutations, some mutations affecting the posttranslational production of HBV proteins in the S ORF like deletion mutations, mutations in start codon and nucleotide changes in the X ORF, deletion and point mutations in P ORF and sometimes, nucleotide substitution in the C ORF are among the assumed mutations detected to have a role in OHBS appearance. Conclusions: Studies mostly lacked a control group and the whole-length HBV sequencing was scant with conflicting results, suggesting that OHBS is often a result of multiple mechanisms. Additional studies on full-length HBV genomes from occult and non-occult HBV cases may shed more light on the interplay between different mechanisms involved in the pathogenesis of OHBS. © 2014, Kowsar Corp.; Published by Kowsar Corp

    Optimization of a solar air heater with phase change materials: Experimental and ‎numerical study

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    In this paper, a solar air heater (SAH) with phase change material (PCM)-based energy storage is ‎investigated. Paraffin was placed underneath the absorber plate as the PCM. A transient two-‎dimensional laminar model was used in the Ansys Fluent 17 software to study the effects of different ‎parameters on the performance of the SAH, such as the air mass flow rate, the amount of paraffin, and ‎the thermal conductivity of the paraffin. The performance of the SAH was optimized by considering ‎two objectives simultaneously: thermal energy efficiency and maximum nocturnal temperature ‎difference between the inlet and the outlet of the SAH. To validate the numerical model, a SAH with ‎a 2-cm paraffin layer and the same dimensions as the numerical model was built and tested. The ‎results of the simulation showed good agreement with the experimental results.

    Anti-influenza antibody level after vaccination in north of Iran

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    Objective:Influenza is a highly transmitted disease and about 10% of the world's population is affected by this disease annually. The aim of this research was to study the variation of serum antibody levels among subjects who had already been vaccinated against influenza. Methods And Materials:This descriptive-analytical study was carried out on 196 subjects who had influenza vaccination (influvac 2005/2006) and on 200 subjects who were matched with the vaccinated subjects by their ages in Gorgan which is located in the northeast of Iran. The subject's sera were prepared seven weeks after the influenza vaccination. Their serum antibody levels were determinated by the heamaglutination inhibition test. Results:The antibody titre in 81 subjects of the vaccinated group and in 175 subjects of the control group was less then 1/40. The mean antibody titre of the vaccinated subjects and the control group was 143.4±10.89 and 18.34±3.2, respectively. The difference was statistically significant (P value=0.000). Conclusion:The findings showed that the mean titre of the antibodies in the vaccinated and control groups was statistically different. This means that the influenza vaccine has good efficacy in our population

    Molecular epidemiology of high-risk types of Human Papillomaviruses (16, 18) in pap-smear, the North East of Iran

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    Background: Cervical Cancer is one of the most important and commonly diagnosed types of cancer in females. There are different causes of cervical cancer, amongst which recurrent and persistent infection with HPV types 16 and 18 are the most renowned ones. These genotypes are the main factors in 99% of cases in developed countries and 70% in developing ones. Due to the importance of these viruses in cervical cancer, molecular detection of HPV and its high risk genotypes in Gorgan was designed. Methods: Pap smears and swabs specimens were taken from 308 women. Papanicola staining method and cytology were used. Nucleic acid was extracted by proteinase K phenol-chloroform standard method and then assessed by using beta-globin primer. Polymerase Chain Reaction (PCR) was then performed for papilomaviruses on all patients and positive cases from both types, including HPV 16 and 18 genotypes, were detected. Results: Three hundred and eight women (15-75 years old) with mean age of 37.54±10.6 were recruited. Seventy six cases (20.1%) of whom were infected with HPV and 48.6% with HPV16 or 18 positive. Normal cytology was seen in 226 cases and 41 patients (18.1%) were HPV positive. Amongst those 152 cases with inflammation or abnormal cytology, 35 cases (23%) were HPV positive. No significant relation was reported between different variables and HPV infections. Conclusions: Due to high rate of HPV infection, as well as its high risk genotypes in different studies, more careful screening of women by Pap smear is recommended

    Crimean-congo hemorrhagic fever: Case series from a medical center in golestan province, Northeast of Iran (2004-2006)

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    Crimean-Congo hemorrhagic fever (CCHF) is a widely distributed lethal disease, worldwide. Humans are usually infected with CCHF virus through a tick bite or close contact with viral contaminated tissues or with blood of domestic animals or of infected patients. The present study reports six cases of CCHF, who were in contact with both infected tissues and blood from sheep. In some regions like Golestan province (North of Iran), clinician suspicion may have an important role in early diagnosis and treatment of the disease. Conservative therapy (intensive monitoring) and prescription of antiviral medication (Ribavirin) accompanied with corticosteroids, was useful at the early stage of CCHF

    Risk factors of esophageal cancer in Turkmen Sahra of Iran

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    Present study was carried out in three years' duration (2002-2004) to investigate the risk factors of esophageal cancer in Iranian Turkmens (Northeast of Iran; where the esophageal cancer is the most common world wide). Concerning registered cases of esophageal cancer in the region, 139 cases were selected. Controls matching in terms of age and sex were 500 healthy individuals. Furthermore, a questionnaire was designated with several questions including: personal characteristics, family history of cancer, possible disease background, and addiction to cigarettes or drugs, and presence of any particular dietary habits. The questionnaires filled with free will (voluntarily) by cases and controls. The collected data was analyzed by SPSS 10.0 software. The mean age of people under study was 60 years. The studied cases were significantly correlated with their first line relatives in term of cancer contraction (P=0.001 and OR=7.6). It was also significant in second and third line relatives (P=0.042 and OR=3.38). There was a significant correlation considering the consumption of stale food and butter with esophageal cancer. As a conclusion, in addition to mentioned risk factors, some other factors as mode of nourishment, employment status, special hygienic habits and inheritance were important factors in esophageal cancer etiology among the studied subjects
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