Tehran University Medical Journal

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Background: The value of the mandibulo-canine index (MCI) in gender identification has been proved in some studies in various countries. The goal of our study was to determine the utility of MCI in gender identification in Iran.

Methods: This descriptional survey was performed on a group of 18- to 25-year-old Iranian students at the Tehran University of Medical Science. We included 50 males and 50 females that were selected using a single sampling method. Data were statistically analyzed by SPSS (v. 13) and t-test.

Results: No statistically significant difference was found between the mean ages of the two groups. Among men, the MCI ranged from 0.209 to 0.293, with a mean of 0.252. Among women, the MCI ranged from 0.202 to 0.276, with a mean of 0.245. There was significant statistical difference between the two means, (0.007 P value = 0.04). The standard MCI of 0.247 was compared to that of each gender, after which no significant statistical difference was found between the two genders (P value = 0.8).

Conclusions: Despite some studies performed in other countries displaying the usefulness of MCI in sex determination, our data did not support this conclusion. Perhaps this difference can be explained because of the variety ethnic groups from various cities of Iran represented in this research had some influence on the results.

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Background: Alkaloids are a group of nitrogenous compounds with potential effects on the physiological behavior of human and animals. Some of these compounds are considered important drugs in modern medicine, such as atropine and morphine. Plants are considered the most important source of alkaloids. Therefore, investigating the presence of alkaloids in different plants is very important. Usually, alkaloids in plants are identified by methods such as those of Dragendorf, Wagner and Meyer, among others, which require milligrams of alkaloids for identification. In the present study, a fast and sensitive procedure for detecting of alkaloids in plants is presented.
Methods: Twelve dried plants samples were investigated for the presence alkaloids. After extracting the total alkaloid into methanol using a Soxhlet extractor, a few milligrams of the extract was transferred to a separatory funnel, buffered to pH 4.7, the bromocresol green (BCG) solution (10-4 M) was added, mixed and extracted with CHCl3 until a yellow color was observed in the CHCl3 layer, indicating the presence of the alkaloid. The crude extracts were also investigated by the standard methods of Dragendorf, Wagner and Meyer for the presence of alkaloids.
Results: Investigation of the 12 plant samples for the presence of alkaloids by the standard reagents of Dragendorf, Wagner, and Meyer showed that only Camelia sinensis (flowers), Echium amoenum Fisch & Mey (flowers), and Stachys (aerial parts) are devoid of alkaloids, with all other samples positive for alkaloids. By the BCG procedure, similar results were obtained, except for the E. amoenum flower, which was positive. The minimum detectable limit for alkaloids by the BCG method is the equivalent of approximately 40μg atropine.
Conclusions: According to previous reports, only one of these plants does not contain alkaloids. All studied plants positive for alkaloids by standard reagents were positive by the BCG procedure. Stachys was negative for alkaloids by both the standard reagents and the BCG method, in agreement with previous reports. However, black tea, reported to contain xanthine alkaloids, was negative for alkaloids by both the standard reagents and the BCG method. Therefore, the BCG method is not suitable for the detection of xanthine alkaloids. Nevertheless, the microgram detectable limit for alkaloids indicates that the BCG method is very sensitive.

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Background: The clinical importance of yeast infections has increased in recent decades. There are 10-15 pathogenic Candida species. The current morphological and physiological methods for identification of Candida species are generally not easy to interpret and may be expensive or time-consuming. In the present study, we introduce and use a new approach for the identification and differentiation of medically important yeast species of Candida. In this method, size polymorphism of the internal transcribed spacer regions, ITS1 and ITS2, of the ribosomal DNA in various Candida species is used as the basis of species recognition.

Methods: The genomic DNA of 31 standard strains and 60 clinical isolates was extracted and PCR-amplified using two primer pairs (ITS1-ITS2 and ITS3-ITS4) separately. Both PCR products were mixed and analyzed after standard agarose gel electrophoresis. The species of the tested yeasts were identified by the electrophoretic patterns of the mixed PCR products of each sample, comparing the data obtained from the sequence analyses of ITS1 and ITS2 molecules.

Results: By this method, with the exception of C. albicans and C. dubliniensis, we were able to clearly differentiate nearly all common pathogenic Candida species, including C. albicans, C. glabrata, C. gulliermondii, C. parapsilosis, C. tropicalis,      C. krusei, C. kefyr, C. lusinaniae and C. rugosa. All standard and clinical strains were identified correctly, without expensive methods such as sequencing and capillary electrophoresis.

Conclusion: It seems that the PCR-FSP method introduced in this study is the easiest molecular approach for the identification of a wide range of pathogenic Candida species and is applicable for diagnostic and epidemiological purposes in reference laboratories.

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Background: Infections caused by opportunistic yeasts such as Candida species, Trichosporon, Rhodotorula and Saccharomyces have increased in immunocompromis- ed patients and their identification is crucial as intrinsic and acquired resistance of some yeast species to antifungal agents are on the rise. The aim of this study was to identify the organisms to the species level in order to suggest accurate and effective antifungal therapies. Methods: In this study that carried out in Tehran, Iran in 2009, 200 patients with yeast infection were medically examined and clinical specimens were prepared for direct examination and culture on Sabouraud dextrose agar. Subsequently, the isolated yeast colonies were identified using various tests including culture on Corn Meal agar with Tween 80, CHROMagar Candida and casein agar. For the definite identification of organisms some biochemical tests were done based on carbohydrate assimilation by RapID Yeast Plus System kit, and, finally, a molecular method, PCR-RFLP, using Hpa II enzyme, was performed for the remaining unknown yeast species. Results: A total of 211 yeast isolates were identified in 200 patients with yeast infections. The most frequent isolated yeasts were Candida albicans, 124 (58.77%), followed by Candida parapsilosis, 36 (17.06%), Candida tropicalis, 17 (8.06%), Candida glabrata, 13 (6.16%), Candida krusei, 8 (3.79%), Candida guilliermondii, 2 (0.96%), Trichosporon, 3 (1.14%), Rhodotorula, 1 (0.47%), Saccaromyces cerevisiae, 1 (0.47%) and other yeast species, 6 (2.84%). Conclusion: Nail candidiasis was the most prevalent type of yeast infection in the patients and Candida albicans was the most frequent isolated species from all clinical specimens.

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Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 Background: Nocardiosis is a rare and potentially life-threatening infection caused by several species of the Nocardia genus. The objective of this study was to develop and evaluate a rapid and new method to clinically identify relevant Nocardia species. Rapid and accurate diagnosis of Nocardia species is essential for the treatment of severe infections and prevention of cerebral abscess.
Methods:  One hundred and eighty patients, 103 (57.22%) male and 77 (42.78%) female, with severe symptomatic pulmonary infection were studied in the course of a 12-month period in Dr. Shariati Teaching Hospital affiliated to Tehran University of Medical Sciences in 2010. The specimens were cultured and identified using microbiological and biochemical tests. Polymerase chain reaction (PCR) was used to directly identify the organism in the broncoalveolar lavage samples collected from the patients. NG1 and NG2 primers were used to amplify a Nocardia genus-specific 598-bp fragment of 16S rRNA.
Results:  Nineteen samples (10.56%) were positive with PCR and 5 samples (2.78%) with conventional methods. All samples with positive cultures were also positive by PCR.
Conclusion: The results of this study showed that PCR has a high sensitivity and accuracy for the detection of Nocardia compared with culture and biochemical tests. Considering the rapidity, precision, high sensitivity and specificity of molecular techniques, use of these techniques is suggested in conjunction with conventional methods for the detection of Nocardia phenotypes in clinical laboratories and research centers.