[Comparison PCR and culture methods for detect coccoid forms of Helicobacter pylori]

Helicobacter pylori [Pylori] was the most common cause of chronic gastritis and was linked to peptic ulcer disease and gastric cancer. Environmental factors such as water a reservoir of H.pylori which infect human, a Non-culture bacteria in coccoid forms widespread in aquatic environments. The objective of this study was elevating the diagnostic value of PCR and culture methods for diagnosis coccoid forms of H.pylori. ITo induce coccoid forms, ten different strains of H.pylori [H1-H10] were inoculated into 30 drinking water samples. Then, the samples were incubated at three different temperatures of 4°C, 22°C and 37°C for the durations of 30 and 60 days. The samples were cultured on brucella blood agar and DNA was also extracted also from them and PCR performed on samples. Percentage of H.pylori cells detected at specified temperatures by the culture were 0%, 10% and 0% in the first month and were 0%, 10%, 30% in the second month whereas by the PCR molecular method were 30%, 80%, and 30% in the first month and were 20%, 20%, and 40% in the second month, respectively. Finding show PCR methods more capable than culture for detect the coccoid forms of H.pylori, therefore this method could be used to detect non-culture forms

Early fetal gender determination using real-time PCR analysis of cell-free fetal DNA during 6[th]-10[th] weeks of gestation

Nowadays, new advances in the use of cell free fetal DNA [cffDNA] in maternal plasma of pregnant women has provided the possibility of applying cffDNA in prenatal diagnosis as a non-invasive method. In contrary to the risks of invasive methods that affect both mother and fetus, applying cffDNA is proven to be highly effective with lower risk. One of the applications of prenatal diagnosis is fetal gender determination, which is important in fetuses at risk of sex-linked genetic diseases. In such cases by obtaining the basic information of the gender, necessary time management can be taken in therapeutic to significantly reduce the necessity of applying the invasive methods. Therefore in this study, the probability of detecting sequences on the human Y-chromosome in pregnant women has been evaluated to identify the gender of fetuses. Peripheral blood samples were obtained from 80 pregnant women with gestational age between 6[th] to 10[th] weeks and the fetal DNA was extracted from the plasma. Identification of SRY, DYS14 and DAZ sequences, which are not present in the maternal genome, was performed using Real-Time PCR. All the obtained results were compared with the actual gender of the newborns to calculate the test accuracy. Considerable 97.3% sensitivity and 97.3% specificity were obtained in fetal gender determination which is significant in the first trimester of pregnancy. Only in one case, false positive result was obtained. Using non-invasive method of cffDNAs in the shortest time possible, as well as avoiding invasive tests for early determination of fetal gender, provides the opportunity of deciding and employing early treatment for fetuses at risk of genetic diseases

Fetal sex determination using non-invasive method of cell-free fetal DNA in maternal plasma of pregnant women during 6[th]- 10[th] weeks of gestation

In previous years, identification of fetal cells in maternal blood circulation has caused a new revolution in non-invasive method of prenatal diagnosis. Low number of fetal cells in maternal blood and long-term survival after pregnancy limited the use of fetal cells in diagnostic and clinical applications. With the discovery of cell-free fetal DNA [cffDNA] in plasma of pregnant women, access to genetic material of the fetus had become possible to determine early gender of a fetus in pregnancies at the risk of X-linked genetic conditions instead of applying invasive methods. Therefore in this study, the probability of detecting sequences on the Y chromosome in pregnant women has been evaluated to identify the gender of fetuses. Peripheral blood samples were obtained from 80 pregnant women at 6th to 10th weeks of gestation and then the fetal DNA was extracted from the plasma. Nested PCR was applied to detect the sequences of single copy SRY gene and multi copy DYS14 and DAZ genes on the Y chromosome of the male fetuses. At the end, all the obtained results were compared with the actual gender of the newborns. In 40 out of 42 born baby boys, the relevant gene sequences were identified and 95.2% sensitivity was obtained. Conclusion: Non-invasive early determination of fetal gender using cffDNA could be employed as a pre-test in the shortest possible time and with a high reliability to avoid applying invasive methods in cases where a fetus is at the risk of genetic diseases