Journal of School of Public Health and Institute of Public Health Research

Evaluation of latex agglutination test (KATEX®) for the detection of urinary antigens in human visceral leishmaniasis

M Mohebali

Background and Aim: In this study, we compared a latex agglutination test (KatexR) with the direct agglutination test (DAT) for the diagnosis of human visceral leishmaniasis (HVL) in an area with a high prevalence of zoonotic visceral leishmaniasis (ZVL) in Iran.
Materials and Methods: The validity of the KatexR (Kalon Biological Ltd, England) for detection of urinary Leishmania antigens in HVL was compared with standard direct agglutination test on 92 visceral leishmaniasis patients (29 were acute and 65 were chronic phase) and 90 healthy controls over a period of one year.
Results: We detected a sensitivity of 82.7% and a specificity of 98.9% in the acute phase. As for the chronic phase, the test showed a sensitivity of 6.15% and a specificity of 98.9% at a 1:3200 cut-off titer. Concordance between KatexR and DAT was 94 .9% in the acute phase and 59. 3% in the chronic phase. As the rapid, noninvasive Katex does not require much expertise or elaborate equipment.
Conclusion: It can be used for screening and diagnosis of human visceral leishmaniasis in remote endemic foci.

Application of bootstrap sample-resample method in logistic regression in analysis of breast cancer data

H Zeraati

Background and Aim: The purpose of this study was to assess the accuracy of the bootstrap method in logistic regression and to explore the method's use in logistic regression models in cases where the sample size is insufficient.
Materials and Methods: We use data from 150 patients who had undergone surgery at the Cancer Institute, Emam Khomeini hospital during from 1999 to 2001. Then we drew repeated samples of size 50 from these 150 patients.
Results: Applying ordinary logistic regression, an appropriate model we fitted to the initial data. Then confidence intervals and standard errors were computed for all regression coefficients. There are many situations where the sample size is insufficient and conditions for using ordinary logistic regression are not met. In these cases the use of the bootstrap method not only produces more accurate estimations of regression coefficients, but with repeated sampling, produces estimates very close to the true values. This holds for the estimation of regression coefficients, confidence intervals and standard errors of coefficients.
Conclusion: In this study we show the optimal number of replications and the optimal sample size when using the bootstrap method in studies involving relatively small sample sizes.

Preventive effect of vitamin D3 on lung tumor formation in balb/c mice

F Koohdani

Background and Aim: In order to elucidate the role of vitamin D in the genesis of lung tumors, we used an experimental model of lung lesions in mice induced by the administration of urethane.
Materials and Methods: A total of inbred balb/c mice (male and female) 9-11 weeks old, were studied. They were divided into 3 groups. The first and second groups (U and U+D) were injected with urethane i.p, 600 mg/kg/day with 48 hours intervals for three times. The second group was given 3.5 mg/kg (6.3 mg/1000 ml) vitamin D with drinking water for 4 weeks after starting the injection by urethane.
Results: The third group served as control. Total remaining mice were killed after 20 weeks. Lung lesions were histopathologically characterized by hyperplasia, adenoma and adenocarcinoma in different groups. Tumor formation significantly increased in the urethane group as compared with control group (p<0.05) but there was not any difference between those receiving the (U+D) treatment group and the controls.
Conclusion: It seems vitamin D inhibites genesis of lung tamors induced by the administration of urethane.

Risk factors for breast cancer in Mazandaran Province, 2004

K Holakouie Naeini

Background and Aim: Breast cancer is the leading cause of cancer death among women, both in Iran and worldwide. The wide variation in breast cancer incidence in different geographical areas calls for studies to clarify the role of potential risk factors. In this study we looked at some factors that could be involved in the pathogenesis of breast cancer.
Material and Methods: This matched case-control study was carried out in the summer of 2004, and it drew on data recorded in Babol (Caspian) Cancer Registry. We investigated 250 biopsy-proven cases of breast cancer, together with 500 controls chosen from the neighbors of cases. We matched the subjects with regard to age (with 3 years intervals). Crude and adjusted odds ratios and relevant 95% confidence intervals were calculated through conditional logistic regression, using STATA 8.0.
Results: This study involved 250 incident cases of breast cancer and 500 age-matched controls. The mean age of the cases was 48.7 (±11.37) years with 48, 22 and 80 years as median, min. and max. values, respectively. Mean age in the controls was 48.0 (±11.46) years with 47.5, 19 and 77 years as median, min. and max. values, respectively. In the multivariate analysis, the following variables were found to be risk factors: university education (OR=5.89, 95%CI: 1.73-20.09), menopause (OR=3.98, 95%CI: 2.29-6.91), induced abortion (OR=1.56, 95%CI: 1.02-2.22), BMI (OR=1.02, 95%CI: 1.01-1.03) and longer duration of breast feeding was determined as protective factor against breast cancer (OR=0.995, 95%CI: 0.990-0.999).
Conclusion: Modifiable risk factors should be considered in the community-based preventive interventions. The following areas could serve as topics for community education in Mazandaran: the role of high BMI and induced abortion in increasing the chance of breast cancer and also the protective role of breast feeding on this issue.

Study of bacterial contamination of milk and milk products in Yazd Province

Salari M.H.

Background and Aim: As the population of the world increases, it is essential that food production keep pace. It will be necessary not only to produce more food, but also to maintain this food so that it is safe and wholesome for human consumption. The purpose of this study was to investigate the rate of Coliform, Staphylococcus aureus, Mould, Yeast and other aerobic and mesophilic bacteria as contaminats of milk and milk products in Yazd province.
Material and Methods: In this study a total of 198 different samples including Milk (24.2%), Yoghurt (21.2%), Cream (12.1%), Cheese (18.2%), Ice cream (12.1%) and dairy powders (12.1%) were investigated by culture method and biochemical tests. Then obtained data were analyzed by SPSS and χ2 programs.
Results: On the basis of our findings, of the total samples, 136 cases (68.7%) were desirable, 48 cases (24.2%) acceptable and 14 cases (7.1%) undesrable. Microbial contaminants of undesrable samples were coliform (7.1%), Staphylococcus aureus (6.1%) and yeast (6.1%). Meanwhile, the results of χ2 Statistical analysis test, showed significant different between contamination rate and kind of Milk products (df = 5, χ2 = 17.75, P<0.005(.
Conclustion: It seems that despite the efforts, which have been done for prevention of food contamination in Yazd province, it is still considered as a threat for people Health.

A seroepidemiological survey of visceral leishmaniasis (KALA-AZAR) in Germi district, Ardabil Province

M Moheb Ali

Familial aggregation of esophageal cancer in Babol district in the north of Iran

K Holakuei Naieni

Background and Aim: The aim of this study is to evaluate the familial aggregation of esophageal cancer in a defined population under coverage of Babol Research Station, Institute of Public Health Research, Tehran University of Medical Sciences, in one of the high incidence areas in north of Iran and to assess the risk of disease associated with first degree familial relationship.
Material and Methods: In this study, the data of family members of three to four successive generations and family history of esophageal and other cancers were collected from esophageal cancer cases which occurred between 2001-2003 in Babol district. The pairwise odds ratio of logistic regression method with GEE2 approach used for familial aggregation of esophageal cancer within first degree family. The results have been adjusted on covariates of age and sex of each family member and age and sex of the proband .
Results: The proportion of having a positive family history of esophageal cancer in first relatives is 3.09% (3.8 % in men and 2.3 % in female relatives). The pairwise odds ratio was 1.79 (95% CI :1.1 , 2/93) in first degree family and odds ratio between parent – offspring was 2.21 (95%CI :1.1 , 4/44)and relation between sibling was 1.92(95%CI: 0.87, 4.24) . It was not possible to look for any parent – parent pattern.
Conclustin: We found a familial aggregation between first degree relatives in this area.The association between parent–offspring suggests the presence of a genetic component in this disease.

Comparison of two nutrition education techniquies on breakfast-eating practice in primary school girls, Tehran

H Sadrzadeh-Yeganeh

Background and Aim: Children, who go to school without breakfast or have breakfast that is not nutritious enough, will not be able to meet their nutritional needs for growth. Nutrition education can be instrumental in providing knowledge, desirable attitude, and changing behavior concerning breakfast. The purpose of this study was to compare two method of nutrition education – booklet and lecture- on practice of fourth grade girls.
Material and Methods: Using three stage random sampling a total of 150 students were randomly selected and divided into 3 equal groups booklet, lecture, and control. At the beginning of the study, an assessment of practice was conducted for all groups. Education through booklet and lecture was provided. Two weeks after the education, an assessment of practice was conducted again. To collect data two types of questionnaires - general and practice - were used.
Results: The result showed a significant difference of means of practice (P=0.002) score among three groups. The mean score of practice in the lecture against the control group and that of the booklet against control group increased 0.84 (P=0.005), 0.76 (P=0.014) respectively, but no significant increase was observed between lecture against the booklet group. After omitting the effect of independent variables in question, education still increases the difference of means of practice scores significantly (P=<0.05). Lectures are a more dynamic method for nutrition education.
Conclustion: Considering the large number of students in primary schools and lack of access to a direct method of education, using booklets is an appropriate method.