A seasonal study for determination of aflatoxin M1 level in dairy products in Iranshahr, Iran.

BACKGROUND AND PURPOSE: Aflatoxin M1, in milk and dairy products, is classified by the International Agency for Research on Cancer as human carcinogens (class 2B). The aim of this study was to evaluate aflatoxin M1 contamination level in dairy products from Iranshahr city, Iran, using ELISA technique. MATERIALS AND METHODS: In our study, 87 samples of milk, white cheese, yoghurt, and butter were collected in different seasons and after preparation, were analyzed by ELISA technique. RESULTS: The contamination level of aflatoxin M1 in pasteurized milk (n=40) yoghurt (n=15), white cheese (n=6), and butter (n=10) samples were determined to be 81.6%, 83.3%, 60%, and 100%, respectively. However, in 8.1% of the pasteurized milk samples, aflatoxin M1 concentration was above the legal accepted limit (>50 ng). The level of aflatoxin M1 was significantly higher in winter compared to summer (P<0.05). In addition, the concentration of aflatoxin M1 was higher in urban regions than rural ones (P<0.05). CONCLUSION: The results of this study emphasized the importance of seasonal and regional effects on aflatoxin M1 contamination of dairy products.

Potential effects of Trachyspermum copticum essential oil and propolis alcoholic extract on Mep3 gene expression of Microsporum canis isolates.

OBJECTIVE: The purpose of this study was to evaluate the effects of Trachyspermum copticum (T. copticum) essential oil and propolis alcoholic extract on growth and transcription of Mep3 gene of Microsporum canis (M. canis) strains. METHODS: The antifungal activity was assayed by broth macrodilution method. Fungal isolates were grown in soy peptone liquid medium and treated with T. copticum oil and propolis extract. Total RNAs of M. canis were subjected to reverse transcription-polymerase chain reaction (RT-PCR). Specific primers of Actin and Mep3 genes were used. RESULTS: The results revealed that MIC values of T. copticum oil against M. canis strains were ranged from 0.2-30.5 µg/mL, with 42.3% of the strains inhibited at 0.9 µg/mL. In addition, MIC values of propolis extract against M. canis strains were ranged from 0.2-488.2 µg/mL, with 34.6% of the strains inhibited at 0.9 µg/mL. RT-PCR analysis of Mep3 and Actin expression showed DNA fragments of 661 and 690 bp amplified in all isolates before treatments with T. copticum essential oil and propolis extract. Both T. copticum and propolis completely inhibited the expression of Mep3 gene. CONCLUSION: We reported for the first time that T. copticum and propolis inhibits the expression of Mep3 gene in M. canis strains in relation to a remarkable inhibition in protease production by the fungus.

Synthesis, X-ray crystallography characterization, vibrational spectroscopic, molecular electrostatic potential maps, thermodynamic properties studies of N,N'-di(p-thiazole)formamidine.

In this work, we will report a combined experimental and theoretical study on molecular and vibrational structure of N,N'-di(p-thiazole)formamidine (DpTF). DpTF has been synthesized and characterized by elemental analysis, FT-IR, FT-Raman, 1H NMR, 13C NMR spectroscopy and X-ray single crystal diffraction. The FT-IR and FT-Raman spectra of DpTF were recorded in the solid phase. The optimized geometry was calculated by HF and B3LYP methods using 6-31G(d) basis set. The FT-IR and FT-Raman spectra of DpTF was calculated at the HF/B3LYP/6-31G(d) level and were interpreted in terms of potential energy distribution (PED) analysis. The scaled theoretical wavenumber showed very good agreement with the experimental values. A detailed interpretation of the infrared and Raman spectra of DpTF was reported. On the basis of vibrational analyses, the thermodynamic properties of the title compound at different temperatures have been calculated, revealing the correlations between Cp,m°, Sm°, Hm° and temperatures. Furthermore, molecular electrostatic potential maps (MESP) and total dipole moment properties of the compound have been calculated.

X-ray crystallography characterization, vibrational spectroscopy, NMR spectra and quantum chemical DFT/HF study of N,N'-di(2-methoxyphenyl)formamidine.

The title compound, N,N'-di(2-methoxyphenyl)formamidine (DMPF) was synthesized and characterized by FT-IR, FT-Raman, (1)H NMR, (13)C NMR spectroscopy and X-ray single crystal diffraction. The results show that the compound crystallizes in an orthorhombic system, with space group of Pbca and eight molecules in the unit cell. The unit cell parameters are: a=11.1118 (7)A, b=14.9878 (9)A and c=16.2851 (10)A. The molecular geometry, the normal mode frequencies and corresponding vibrational assignments of DMPF at the ground state were performed by HF and B3LYP methods with 6-311+G(d,p) basis set. It was observed that the bond lengths and angles in the molecule, obtained by X-ray at the level of theory, were in good agreement with those of the experiment. A detailed interpretation of the infrared and Raman spectra of DMPF was reported. The (13)C NMR and (1)H NMR of DMPF have been calculated using HF and B3LYP methods with 6-311+G(d,p) basis set. Comparison between experimental and theoretical results showed that B3LYP/6-311+G(d,p) method is able to provide more satisfactory results for predicting IR, Raman, (1)H NMR and (13)C NMR properties.

Analysis of ligand binding process using binding capacity concept.

Binding capacity is the homotropic second derivative of the binding potential with respect to the chemical potential of the ligand. It provides a measure of steepness of the binding isotherm and represents the extent of cooperativity. In the present study, the shape of the binding capacity curve for various systems was investigated and the relation between binding capacity and the extent of cooperativity examined. In this regard, a novel linear graphical method was introduced for binding data analysis. The stoichiometry of binding and the extent of cooperativity can be determined by this method. This method has been successfully applied to various systems such as binding of oxygen to hemoglobin, warfarin to human serum albumin and dodecyltrimethylammonium bromide to alpha-amylase.

[Surgical indications and techniques in Basedow's disease, multinodular goiter and thyroid cancers]. / Indications et techniques chirurgicales dans la maladie de Basedow, le goitre multinodulaire et les cancers thyroïdiens.

This is a retrospective study of 47 near total and 30 total thyroidectomies for multinodular goiter, Graves' disease and thyroid cancer. Complications are rare: one permanent recurrent nerve palsy out of 154 nerves at risk, one definitive hypoparathyroidism. For a benign pathology, the former bilateral sub-total thyroidectomy should be replaced by a near-total thyroidectomy which leaves one unilateral thyroid remnant the size of a cherry. Using this technique, we did not observe any recurrence. Among 42 patients controlled after more than one year 1/3 have a normal thyroid function. Systematic substitution is not indicated. Thyroxine should be used only if hypothyroidism develops after the operation or if an increase of the thyroid remnant is demonstrated. Thyroid cancer should be treated by total thyroidectomy, except for noninvasive papillary cancer without node metastasis for which a total lobectomy is sufficient.

[Thyroid nodules. Surgical aspects]. / Nodules thyroïdiens. Aspect chirurgical.

This is a restrospective study of 176 thyroid nodules operated between 1977 and 1990, excluding bilateral goiters. 145 were benign with 111 cold and 34 hot nodules; 31 were cancers. Fine needle biopsy (FNB) is useless in hot nodules. For the cold ones, even in recent series, FNB can give false positive or negative results. This means that the answer of FNB should be closely related to the clinical and US findings. The surgical treatment of thyroid nodules must be a total lobectomy including the isthmus. The recurrent laryngeal nerve must be followed entirely. There was no permanent nerve palsy among the 122 total lobectomies. The risk of developing another controlateral nodule later is low (2/110 cases). It is very difficult to distinguish a follicular cancer from an adenoma on frozen section. For this reason, the patient should be warned that a second operation might be necessary some days later if the definitive diagnosis is a follicular cancer. For a non-invasive and non-metastatic papillary cancer, total lobectomy is sufficient. More advanced papillary and all other thyroid cancers should be treated by a total thyroidectomy.