Iranian Journal of Public Health
Volume:34 Issue: 1, Spring 2005

Abstract: While hearing loss has been considered to be a very heterogeneous disorder, mutations in Gap junction beta 2 (GJB2) gene encoding Connexin 26 (Cx26) protein are the major cause of autosomal recessive and sporadic non-syndromic deafness in many populations. In this study, we have investigated the prevalence of the GJB2 gene mutations using nested PCR pre screening strategy and direct sequencing method. Two hundred and seventy two hearing impaired subjects were studied from 210 families obtained from two large cities of Iran (Tehran and Tabriz). Twenty four different genetic variants were identified. Cx26 mutations were found in 53 of the 210 families (25.2%) including T8M, 35delG, W24X, R32H, V37I, E47X, 167delT, delE120, Y136X, R143W, R184P, 235delC and V27I+E114G. Homozygosity and compound heterozygosity for the Cx26 mutations were found in 39 of 210 (18.5%) families. Homozygosity for the 35delG mutation was the most common that causes hearing loss in 28 (13.3%) patients. Six novel variants H16R, E101E, K102Q, G200R, 327delG and G130A were detected in this study. As a conclusion, the present survey revealed that the rate of mutation in Cx26 gene in our area is lower than in Europe; nevertheless, this rate is regarded as a considerable cause of deafness in the cited provinces in Iran.

Abstract: Strongyloidiasis, caused by a nematode parasite so-called Strongyloides stercoralis is one of the major human intestinal nematode infections. Considering that stool examination for Strongyloides larvae is not a sensitive method and immunodiagnostic methods are more applicable for this purpose, so the present study was conducted to compare the somatic (S) and excretory - secretory (ES) antigens of Strongyloides stercoralis in IgG-ELISA to diagnose human strongyloidiasis. Serum samples obtained from 50 individuals infected with Strongyloides stercoralis. Sera from healthy control individuals, not infected with any parasitic diseases (n=/30) and from others with different parasitic infections including hydatidosis (n=20), toxocariosis (n=18), ascariasis (n=2), trichostrongylosis (n=10), and hymenolepiasis (n=2) were examined as well. The cut-off point for (S) and ES was 0.48 and 0.36, respectively. Thirty eight and 42 out of 50 individuals infected with Strongyloides stercoralis were also seropositive using (S) and ES antigens, in that order, whereas 15 cases of false positive reactions for (S) and 10 for ES antigen were detected when non-strongyloidiasis sera were examined, therefore the sensitivity of the test was 80.6% and 86.2% for (S) and ES antigens, respectively. The specificity of those antigens was calculated as 84.2% and 88.2%, correspondingly. It was concluded that overall ES antigen showed a more convincing diagnosis in comparison with (S) antigen, although every interpretation of the results should be in accompany with clinical manifestations and a history of the disease.

Abstract: Cryptosporidiosis is a gastroenteric disease caused by the protozoan parasite Cryptosporidium parvum. Water–borne transmission of this organism has become more prevalent in recent years. Current method for detection of C. parvum oocysts in water is immunofluoresence assay (IFA). The method is time consuming, laborious and particularly not–specific. It cannot determine the infectivity of detected oocysts. We have evaluated a nested- PCR assay for sensitive detection of C. parvum oocysts in water samples. Water sample concentrates were spiked with Cryptosporidium oocysts and after DNA extraction and purification by QIAamp DNA mini kit, detection was achieved by nested PCR amplification of a 200 bp region of hsp70 gene specific for C. Parvum. The method could detect as few as one oocyst in seeded tap water samples. On the basis of these results, PCR could be a useful tool in the monitoring of water samples for the detection of Cryptosporidium oocysts.

Abstract: Toxoplasmosis is a widespread infection in the world. Although the infection by Toxoplasma gondii is widely prevalent in humans and animals, the disease is uncommon and most of the acquired infections are asymptomatic. The important aspect of this parasitic infection is the probable danger of congenital transmission and its severe effects on the fetus. In the present descriptive study, a total of 353 samples from mentally retarded children and adolescents in rehabilitation centers in Tehran, were examined from 2001 to 2002. In order to determine the Toxoplasma antibodies, the samples were tested using an IFA technique and in some cases ELISA technique was applied as well. Fourteen percent of the examined samples were positive. In this research Toxoplasma antibody titer in 36 cases were reported as 1:100 and it was found to be 1:200, 1:400 and 1:800 in 9,1 and 3 cases, respectively. In three cases for which the titer was reported 1:800, samples were tested applying Ig-M ELISA technique in order to determine if there was an acute infection but all tests were negative. In the current study, we did not find any significant differences in the prevalence rate between the genders, but the prevalence significantly increases with age. We used standard questionnaires for causative relation in congenital toxoplasmosis within sero-positive children and 3 cases of infection were documented during the mother''s pregnancy period

Abstract: Vitiligo is a common skin disorder, characterized by depigmented patches due to selective destruction of melanocytes. The etiology of this disease is unknown. A number of hypotheses including viral theory have been proposed to explain the etiology. To determine the prevalence of antibody to hepatitis C virus infection in vitiligo patients, the present study was performed. Third generation ELISA test was used for detection of antibodies to HCV in human sera. All normal controls were anti-HCV negative whereas only one patient was positive for anti-HCV and there was no significant difference in the prevalence of anti-HCV between patients and controls. These results indicate that hepatitis C virus has not a direct causal role in the pathogenesis of vitiligo, however, this does not rul out a "hit and run" virus induced disease.

Abstract: The Clara cell protein (CC16) is a small and readily diffusible protein of 16 kDa secreted by bronchiolar Clara cells in the distal airspaces. Mutation detection methods identified an adenine to guanine substitution in the CC16 gene at position 38 (A38G) downstream from the transcription initiation site within the non-coding region of exon 1. In the present study, the genetic polymorphism of CC16 was detected by PCR-based method in 175 normal individuals from Shiraz population, Fars province (south of Iran). Initially the subjects were divided into two sex groups. Considering that there was no statistically significant differences between males and females (χ2 = 5.52; df = 2; P<0.05) the sex groups were pooled. The frequencies of 38A and 38G alleles were 0.24 and 0.76 percent, respectively. The study population was at Hardy-Weinberg equilibrium (χ2 = 2.61; df = 1; P<0.05). The present results indicated that this polymorphism might have a geographic distribution.

Abstract: Stress and mental health at the place of work have received great attention by researchers. In spite of technology improvement in high-tech systems, the operators face new problems, which can affect mental health. There is hardly any published research about stress or mental health in such workplaces in developing countries. This paper presents the application of the self-rating scale General Health Questionnaire (GHQ-28) to study mental health of 160 controllers working in a part of Air Traffic Control (ATC) as a high-tech system in Iran. Logistic regression analysis showed that demographic variables did not exhibit a statistically significant effect on scores of the test. In order to compare mental health of these operators with general population, an exposure / non-exposure study was designed. Three age groups (less than 29 years, 30 through 39 y, and more than 40 y) were compared in exposed and non-exposed groups. The results of Fisher’s exact test showed that mental distress symptoms were significantly higher in the exposed group. There were significant job effects on somatization, anxiety and depression as well as on the total score of GHQ-28 for the two first age groups (P<.05). No significant effects of the job were found on social dysfunction symptoms in any age groups. The risk ratio of expressing depression and anxiety symptoms were more than three times greater in these operators than general population.

Abstract: Hydatid disease is a term used to refer infection with the methacestode of Echinococcus granulosus parasite in humans, and echinococcusis is restricted to infection with the adult stage in carnivores.Glutathione S-Transferase (GST) represents the major class of detoxification enzymes from helminth parasites such as Echinococcus protoscoleces (PSC) and it is candidate for chemotherapeutic and vaccine design. Therefore, GST of protoscoleces could be a target for evaluation of drug effect as triclabendazole in hydatid cyst. For this purpose, GST enzymes were purified from protoscoleces of hydatid cyst and sheep liver tissue by glutathione affinity chromatography using a wash-batch method and subsequently detected their SDS-PAGE pattern. Afterward, GST specific activity levels were assayed in the whole extract and purified solutions spectrophotometrically at 30°C with reduced glutathione (GSH) and 1-chloro-2, 4-dinitrobenzen (CDNB) substrate. Finally, GST inhibition assay was investigated in the solutions by powder and bolus of triclabendazole. GST fraction as a 26 kDa (MW) band was obtained on SDS-PAGE. The level of GST specific activity in purified solutions was detected 10.24 µmol/min/mg proteins for protoscoleces and 37.84 µmol/min/mg protein for liver tissue. Comparison of the effect of powder and bolus of triclabendazole in solutions revealed inhibition concentration (IC50) 8.71 and 11.16 µg/ml for protoscoleces GST and 8.65 and 9.70 µg/ml for liver tissue GSTs, respectively. These findings suggest the possibility of selective inhibition of protoscoleces. GSTs by triclabendazol in vitro and use of these results for understanding of its molecular effect in vivo.

Abstract: Autosomal recessive and sporadic non-syndromic hearing loss (ARSNSHL) is the major form of hereditary deafness.Mutations in the GJB2 gene encoding the gap-junction protein Connexin 26 have been identified to be highly associated with ARSNSHL. In this study we have analyzed 196 deaf subjects from 179 families having one or more deaf children in 3 proviences of Iran, including Kordestan, Khuzestan and Golestan. The nested PCR prescreening strategy and direct sequencing technique were used to detect the mutations in coding exon of the gene. Altogether 3 GJB2 recessive mutations including 35delG, 167delT and V27I+E114G, were identified in 23 of 179 families (12.8%). Fourteen of 179 families were observed to have GJB2 mutation in both alleles (7.8%). A novel variant (R159H) also was found in a deaf family from Khuzestan. Four polymorphisms V27I, E114G, S86T and V153 I also were detected in 7 families. A polymorphism (S86T) was seen in the whole population studied. Our data indicated that the rate of connexin 26 mutations is different in this three Irainian population and is lower than the high frequency of 35delG (26%) reported from Gilan province in the north of Iran.

Abstract: Human parvovirus B19, the causative agent of fifth disease in childhood, is non-enveloped DNA virus and resistant to many physicochemical agents. B19 is a potential risk to hemophiliac patients receiving blood products. To determine the prevalence of the corresponding antibody in patients with hemophilia A or B or Von Will brand’s disease (VWBD), we tested 180 hemophilia patients aged 1-45 years for anti B19 IgG. This work was descriptive, cross-sectional study. The results were compared with those of 400 age-matched controls, male blood donors and male children (18-45 and 3-17 years of age, respectively). The overall prevalence of B19 IgG in the hemophilia patients was 74% (133/180), and in the controls 56.5% (226/400, P<0.001). The significant difference in prevalence of B19 IgG between hemophiliacs and healthy persons demonstrated that there was a high risk of transmission of parvovirus B19 through plasma- derived clotting products. These observations demonstrate that parvovirus B19 is frequently transmitted in blood products. Existing virus-inactivating methods do not prevent transmission.

Abstract: Due to the worldwide increase in the number of older people in both developed and developing countries, there is a public health concern for dealing with age related diseases such as neurodegenerative diseases. There is little known about the difference in neuronal cell responses between genders. Our understanding of the neuronal cell response regarding genders, will be useful for developing more efficient therapies for these diseases such as Alzheimer’s disease. To investigate gender differences in neuronal cell response against cell death inducers, we examined the percentage of cell death in male and female mouse primary cortical neuronal cultures. Our findings indicate that there is a difference in cellular response to ethanol (a cell death inducer) that may be the basis of how they behave in vivo of what may be seen in adults, as they age. These observation support this idea that genetic factors, most likely governed by X or Y chromosomes.

Abstract: The treatment facility of Albourz Industrial City was established in 1999 at the southeast of Albourz Mountain with an area of 200,000 square meters. Currently, 40,000 cubic meters of industrial wastes are treated daily utilizing biological method of activated sludge up to the second phase without chlorination in this treatment facility. Then, the discharged wastes are directed toward the lower agricultural lands. The environmental status of the region was investigated by testing the impact of wastewater and agricultural products in four tries. In two tries, the levels of COD and BOD were higher than the environmental standards, but there was no trace of heavy metal contamination in any of the tests. In order to make inquiry about the general health of the residents and domesticated animals, a questionnaire for the farmers and animal of husbandmen was prepared. The residents were dissatisfied with the utilization of wastewater for their domesticated animals. However, farmers were content and satisfy due to their need to compensate the shortage of cultivation water with the freely available discharged wastewater of the industrial city. Because there is no enough water in Iran, they have to buy water from tankers. In the other way wastewater of Albourz industrial city had some metals and mineral materials, so it effected on growth of agricultural product, this shows a little bit of metals and mineral materials is useful for plants. An inquiry about the status of public health and diseases transferred by water was conducted and local physicians were interviewed and statistical data was collected. The number of reported cases of cholera and typhoid was low, but the number of parasitic disease cases due to remains of human waste in water was quite high. Approximately, most of the local residents were suffering from stomachaches related to parasitic disease and physical weakness. It is recommended that the Department of the Environment conduct educational programs for the employees of Industrial Cities in order to persuade them on the benefits of mandatory chlorination process in the treatment facility for the sake of employees and public health. Meanwhile, related laboratory tests to be followed up and studied by pertinent organizations to ensure proper management and planning of the discharged wastewater resources; the wastewater is a valuable source of irrigation water.

Abstract: Self etching primers, due to ease of manipulation, have been extensively used in recent years. These self etching primers containing a relatively weak acid, may not provide an optimal bond strength. The purpose of the present in-vitro investigation was to evaluate the effects of 37% phosphoric acid application prior to applying self etching primers on composite bond strength. In this experimental study a total of 48 premolar and molar teeth, free of caries, filling, abrasion, crack or other dental defects were selected. The extracted teeth were immediately stored in physiologic serum and divided randomly into two equal groups (n=24).Each group was also divided into two subgroups of twelve teeth each as follows: Subgroup A: enamel was not acid-etched, subgroup B: enamel was acid-etched (group I).Subgroup C: dentin was not acid- etched, subgroup D: dentin was acid-etched (group II).In acid-conditioned groups, water rinsing was followed by the application of a bonding agent (Etch & Primer 3), however for non-acid-treated groups, just the bonding agent was used. Then composite resin blocks (1.5×2 mm and 2.5 mm in diameter) were formed and light cured at all directions for 40 seconds, following this the specimens were placed in an Instron universal testing machine to determine shear bond strength. The data were analyzed by t-test. Results showed that no statistically significant differences were between the mean values of etch and un-etch enamel (P=0.232), similarly those of etch and un-etch dentin (P=0.148). In this investigation we concluded that acidic components employed in self-etching primers were of weak type, but self-etching primers could be used without phosphoric acid conditioning

Abstract: T4 and T3, two major hormones of thyroid gland, are responsible for regulation of “basal metabolism” in the body. Thyroid function is regulated primarily by variation in the pituitary TSH. In this study, about four hundred individuals were considered from four Iranian populations. They were selected randomly in their cities; Shiraz, Mashhad, Rasht, and Ilam. Essential family information was asked to achieve native belonging of each person to related population. Blood specimens were collected, by separating serums, freezed serums were transferred immediately to Tehran for hormone assay. Assay of T4 and T3 concentrations was carried out by “RIA-magnetic” kits and of TSH by “IRMA-magnetic” kits. Analysis of variance has been taken into account among days of sampling in each city to calculate mean concentrations for T4, T3 and TSH. Analysis of association between age and hormones concentrations in each population was done by the regression and the correlation tests. Significant differences were detected at T4 mean concentration in each of these populations (P=0.0001). Differences for T3 mean concentration were observed only between Shiraz and Mashhad (P=0.021); and Shiraz and Rasht (P=0.003). By increasing age of individuals, there were also a negative correlation at mean concentrations of T4 and T3 in Ilam (P=0.022), and Mashhad (P=0.016) respectively. According to these data, and specificity of environmental and genetic factors to each popualtions, specific “normal reference” of T4 and T3 homones should be considred for each of these populations. Correlation study of mean concentrations of these hormones and genetic variations of some critical genes such as thyroid peroxidase (TPO) and iodothyronine deiodinase can open new window of epidimiology among Iranian popualltions.