Residential segregation and infant mortality: a multilevel study using Iranian census data

There is a great amount of literature concerning the effect of racial segregation on health outcomes but few papers have discussed the effect of segregation on the basis of social, demographic and economic characteristics on health. We estimated the independent effect of segregation of determinants of socioeconomic status on infant mortality in Iranian population. For measuring segregation, we used generalized dissimilarity index for two group and multi group nominal variables and ordinal information theory index for ordinal variables. Sample data was obtained from Iranian latest national census and multilevel modeling with individual variables at level one and segregation indices measured at province level for socioeconomic status variables at level two were used to assess the effect of segregation on infant mortality. Among individual factors, mother activity was a risk factor for infant mortality. Segregated provinces in regard to size of the house, ownership of a house and motorcycle, number of literate individual in the family and use of natural gas for cooking and heating had higher infant mortality. Segregation indices measured for education level, migration history, activity, marital status and existence of bathroom were negatively associated with infant mortality. Segregation of different contextual characteristics of neighborhood had different effects on health outcomes. Studying segregation of social, economic, and demographic factors, especially in communities, which are racially homogenous, might reveal new insights into dissimilarities in health

Utility of filter paper for preserving insects, bacteria, and host reservoir DNA for molecular testing

Appropriate methodology for storage biological materials, extraction of DNA, and proper DNA preservation is vital for studies involving genetic analysis of insects, bacteria, and reservoir hosts as well as for molecular diagnostics of pathogens carried by vectors and reservoirs. Here we tried to evaluate the utility of a simple filter paper-based for storage of insects, bacteria, rodent, and human DNAs using PCR assays. Total body or haemolymph of individual mosquitoes, sand flies or cockroaches squashed or placed on the paper respectively. Extracted DNA of five different bacteria species as well as blood specimens of human and great gerbil Rhombomys opimus was pipetted directly onto filter paper. The papers were stored in room temperature up to 12 months during 2009 until 2011. At monthly intervals, PCR was conducted using a 1-mm disk from the DNA impregnated filter paper as target DNA. PCR amplification was performed against different target genes of the organisms including the ITS2-rDNA of mosquitoes, mtDNA-COI of the sand flies and cockroaches, 16SrRNA gene of the bacteria, and the mtDNA-CytB of the vertebrates. Successful PCR amplification was observed for all of the specimens regardless of the loci, taxon, or time of storage. The PCR amplification were ranged from 462 to 1500 bp and worked well for the specified target gene/s. Time of storage did not affect the amplification up to one year. The filter paper method is a simple and economical way to store, to preserve, and to distribute DNA samples for PCR analysis

[Comparison of nested case-control and cohort analysis methodologies using a district TB registry data]

The nested case-control study has become popular as an efficient alternative to the full-cohort design. This study compares the results of a nested case-control analysis approach with the full cohort analysis. A cohort of 276 subjects [new cases from a TB registry] was used for this study. Cox Regression model was used for the full cohort analysis. In order to do the nested case-control analysis, for each death, three random controls were selected from those who did not suffer from the outcome at the time of the outcome took place. Case control data was analyzed by the conditional logistic regression model. Results from both cohort and nested case-control analyses show that treatment group is the only variable that affects on the outcome. Gender, place of residence, and age has no effect on the outcome. For binary exposure variables with trivial effects [e.g. Gender and place of residence], the relative efficiency of nested case-control study design is approximately 75%. Results of this study show that nested case-control study is not only an easy and cost-effective method for data analysis but also is as robust as cohort analysis in rate ratio and its variance estimation

[Antibacterial activity of hydroalcoholic extract of Salvia officinalis and Achillea millefolium against cariogenic microorganisms: an in vitro investigation]

There is an increasing global tendency to use traditional medicines and drug-extracts from natural plant materials. This in-vitro study was conducted in order to evaluate the cariostatic effect of hydroalcoholic extract of Salvia officinalis and Achillea millefolium. In this experimental study, hydroalcoholic extracts were prepared from Salvia officinalis and Achillea millefolium using maceration method. The antibacterial activity of these two extracts against Streptococcus mutans, Lactobacillus rhamnosus, and Actinomyces viscosus were evaluated through broth macrodilution method. Data was analyzed with Mann-Whitney test. The Minimum Inhibitory Concentration [MIC] of Salvia officinalis and Achillea millefolium for streptococcus mutans were 6.25 and 50 micro gram per milli liter, respectively. The corresponding figures for Lactobacillus rhamnosus were 1.56 and 12.5 micro gram per milli liter; and for Actinomyces viscosus the value were 12.5 and 50 micro gram per milli liter, respectively. The differences between the two extracts were statistically significant. Both extracts had growth inhibitory effect on all three bacteria. Salvia officinalis showed greater inhibitory effect on growth of all three bacteria. Both extracts had bactericidal effect in the considered concentration range

[Use of rat estrus serum for in vitro maturation of bovine oocytes]

Superovulation produces complications in some patients, so in vitro maturation of oocyles is used to decrease or eliminate these complications and improve IVF. Moreover, IVM is used for different aspects of reproductive researches. Slaughterhouse ovaries are the main source of oocytes for IVM and IVF studies. Different media has been introduced and experimented for in vitro maturation of oocytes. Animal's serum at estrus stage contains different hormones and proteins which are essential for oocyte maturation. The aim of this study was to compare three culture media for in vitro maturation [IVM] of bovine oocytes; 1][control]TCM-l99, 2]HCG and follicular fluid [FF] and 3] antibiotic. Rat estrus serum [RSS] or fetal bovine serum [FBS] was added to control medium. Total of 1789 compact cumulus oocyte complexes [COCs] were aspirated from ovaries of slaughtered animals. Oocytes were randomly cultured in mentioned media and incubated in 38.5°C, 5% CO2 and 95% humidity for 24 hours. The maturation of oocytes was judged according to cumulus cell expansion or randomly orcein stained oocytes and observation of polar bodies. The results showed that maturation rate was significantly higher in second and third group [90.2%, 78.7%] as compared to the control group [p<0.001]. There was no significant difference between second and third groups [90.2% vs. 86.6%]. RSS is as effective as FBS for IVM of bovine oocytes and can be used as an alternative