BACKGROUND: Tetracyclines (TCs) are broad-spectrumantibiotics that are widely used in veterinary medicine. Thepresence of TCs residues in milk is a public health concern allover the world. OBJECTIVES:This study aimed to determine TCsresiduals in pasteurized milk marketed by some dairy companiesin Tehran from April 2011 to March 2012. METHODS: 432pasteurized milk samples were purchased from supermarketssupplying the milk products of 12 major dairy companies inTehran (3 samples from each company every month), and theywere stored at -20 0C until analysis. Oxytetracycline (OTC) andTetracycline (TC) residues in each sample were extracted by aliquid - liquid phase procedure and quantitated using a highperformance liquid chromatographic (HPLC) method. Chromatographicconditions included a mobile phase as oxalic acidbuffer- acetonitril (80: 20) with a flow rate of 1mL/min and UVdetectionat 355 nm. RESULTS: TCs residuals in most milksamples were lower than 100 ppb, maximum residue level(MRL); however, in seven samples (1.62%) the total residues ofOTC and TC were more than MRL. In the latter milk samples, themedian total TCs residue was 625 ppb, ranging between 274 and1270 ppb. CONCLUSIONS: Because of the presence of TCresidues above the MRL level in a limited number of milksamples, it is concluded that more studies and supervision ofhealth authorities are needed in this field.

BACKGROUND: Aflatoxin B1 (AFB1) is a toxic metaboliteproduced by Aspergillus species that contaminates a wide range ofagricultural products. OBJECTIVES: This study was designed todevelop a rapid and highly sensitive immunoassay method inmicroarray format for quantitative detection of AFB1 to evaluatethe potential of microarray platform for high-throughput screening,which can be beneficial in food and feed industry. METHODS:Following successful optimization, using an indirect competitiveimmunoassay in dot blot format, AFB1-bovine serum albumin(AFB1-BSA) conjugate was contact-printed onto 16 isolated subarrayson multi-pad nitrocellulose coated slides; subsequently usedin competitive binding assays. RESULTS: Using the aforementionedassay, AFB1 was determined from 15 pg/g to 3.04 ng/g workingrange with detection limit (LOD) of 1 pg/g. To evaluate assayperformance in real food matrices, the authors spiked wheatsamples with different concentration of AFB1. After extraction,working ranges of 0.11-4.15 ng/g with detection limit of 30pg/g wasdetermined. Good recoveries (94±9%) were obtained, demonstratingaccurate detection of AFB1 concentrations in wheat samples.Assay procedure completed in 3 hours. CONCLUSIONS: The resultsindicated that the proposed developed assay in microarray formatcould be used for rapid and sensitive detection of AFB1in wheatsamples.

Perosomus elumbis is an occasional congenital anomaly ofcattle, swine, sheep, and dogs with unknown etiology. Thiscongenital abnormality occurs in both sexes. A dead Holsteincalf characterized by musculoskeletal and external genitaliaabnormalities was referred to the large animal hospital ofUniversity of Tehran. Radiographic evaluation and subsequentdissection revealed that the vertebral column was truncated at thelevel of first lumbar vertebra (L1). Moreover, L2-L5, sacrum andcoccygeal vertebrae were absent. The dorsum of the lumbosacralregion contained only soft tissues. Urogenital tract wasincomplete, and it contained agenesis of the ovaries, uterinetubes, cervix, and vulva concurrent with unilateral umbilicalartery agenesis. Small and large intestine contained blind-endedsacs. No testes, scrotum, and penis were found. The intact ureterwas attached to a thin-walled fluid fill sac. The laboratory findingshowed that the pH of the fluid was 6 and contained hemoglobin,white blood cells, bacteria, a few red blood cells, oxalatecrystalline, and epithelial cells. It was concluded that thecollected fluid was urine. This is the first report of perosomuselumbis in a Holstein calf having a lot of visceral abnormalitiesin Iran.

BACKGROUND: Among all common techniques in sitedirectedmutagenesis, λ Red recombinase system has beenwidely used to knock out chromosomal genes in bacteria. In thismethod, there is always the risk of DNA Linear digestion byhost's restriction enzymes that leads to the low frequency ofrecombination. OBJECTIVES:To overcome this, we constructeda recombinant vector to disrupt phoP gene in Salmonellatyphimurium. METHODS: The SOEing PCR method andrestriction enzymes were used to construct the vector. RESULTS:The resulting plasmid, pTAAZ92, contains a Kanamycincassette with two long homologous arms flanking of the phoPgene. CONCLUSIONS: After electrotransformation of thepTAAZ92 into the Salmonella typhimurium , the phoP gene isreplaced by the Kanamycin cassette through homologousrecombination. According to the high homology of the phoPgene in many of Salmonella species the pTAAZ92 can be used todisrupt the phoP gene in most of these species.

BACKGROUND: Urinary oxalate and citrate are the keyfactors in caox urolithiasis of cats and Gamma GlutamylTransferase is a good test for assessment of kidney damage.Favorable effects of Cynodon dactylon on calcium oxalate stoneformation have recently been proved in rats. OBJECTIVES: Thepresent study was designed to investigate the alteration ofurinary oxalate, citrate, and GGT after administration of thehydroalcoholic extract of Cynodon dactylon to experimentalhyperoxaluric cats. No scientific study has been done so far todemonstrate the beneficial effect of this plant in cats. METHODS:13 mature male cats were randomly divided into 3 groups: groupAreceived standard diet and drinking water while, group B andC also received ethylene glycol at sub-toxic dose (130 mg/kg)daily for 30 days. Group C received hydroalcoholic extract ofC.dactylon (400 mg/kg) from day 0 to 30, as well. Urine sampleswere collected on days 0, 15, and 30 and were analyzed foroxalate, citrate, and GGT levels. RESULTS: Urine oxalate levelin group B was significantly higher than group C on days 15 and30. Urinary citrate excretion was significantly higher in group Ccompared to the other groups on day 15; however, it decreasedduring the entire experiment in groups B and C. Urinary GammaGlutamyl Transferase level was increased in hyperoxaluric catsand decreased in the treated group during the experiment.CONCLUSIONS: Based on our results, C.dactylon extract couldreduce the hyperoxaluria and has beneficial effects onpreventing the renal damage in cats. Such findings provide ascientific explanation for applying C.dactylon in prevention andpossible treatment of CaOx kidney stones in cats and humans.

BACKGROUND: All-trans retinol is a biological antioxidantscavenging the ROS in the cell culture. OBJECTIVES: This studywas conducted to investigate the effect of all-trans retinol infertilization and culture medium on mouse embryo's developmentalcompetence. METHODS: This study was designed into twoexperiments. In the first experiment, in vitro mature oocytes wereco-cultured with sperm in fertilization medium containing differentconcentrations of all-trans retinol (0, 1, 5, and 10 μM). Afterfertilization, zygotes in each group were separately cultured in CZBculture medium for 5 days to the blastocyst stage. In the secondexperiment, in vitro produced zygotes were cultured in CZB culturemedium containing different concentrations of all-trans retinol (0,1, 5, and 10 μM) for 5 days to the blastocyst stage. RESULTS: In thefirst experiment, the blastocyst formation rate significantlyincreased by 5 μM in all-trans retinol, which was more than those ofthe other groups. Also, percentage of grade one embryos wassignificantly higher in the presence of 5 μM all-trans retinol thanthose in the presence of 0 and 1 μM all-trans retinol. In the secondexperiment, different concentrations of all-trans retinol could notalter blastocyst formation rate; however, the percentage of gradeone embryo was higher in the presence of 10 μM all-trans retinolthan that of the control group. CONCLUSIONS: These resultsshowed that supplementation of fertilization medium with 5 μM alltransretinol could improve mouse embryo's development andmorphology. On the other hand, supplementation of embryo culturemedium can improve mouse embryo morphology without anyeffect on embryo developmental competence.

BACKGROUND: Growth promoters are chemical and biologicalsubstances that are added to livestock food with the aimto improve the growth of chickens in fattening and the utilizationof food, and in this way achieve better production and financialresults. OBJECTIVES:An experiment was conducted to evaluatethe effects of enzyme complex, probiotic, and their combinationon performance of broilers fed a basal wheat-barley-soybeanmeal diet from 1 to 47 d of age. METHODS:Atotal of 480-dayoldmale broiler chicks (Arbor Acres) were randomly assigned to6 treatments, with 4 replicate cages per treatment and 20 birds percage. The experiment consisted of a 3×2 factorial arrangementof the treatments, with 3 concentrations of enzyme complex (0,half of the commercial suggested level or commercial suggestedlevel) and 2 concentrations of probiotic (0 and suggested level).RESULTS: Results showed that the suggested level of enzymecomplex could improve body weight and feed conversion ratio(p<0.05), but addition of probiotic only decreased the feedconversion ratio (p<0.05). There was no interaction betweenenzyme complex and probiotic on performance (p>0.05).Probiotic supplementation did not improve the efficacy ofenzyme complex at any levels. The examination of length andrelative weight of different regions of intestine showed that onlyenzyme complex could decrease the relative weight of duodenumand length of jejunum; however, there was no interactionbetween treatments for these parameters. CONCLUSIONS: Thisresearch did not demonstrate any interaction effect betweenenzyme complex and probiotic on broilers performance fedwheat-barley-soybean meal diet.

A2-year-old cachectic cross-breed gelding was admitted toVeterinary Teaching Hospital of University of Tehran followingthe onset of a marked respiratory distress, coughing and ventraledema. Clinical examinations indicated harsh respiratory andexpiratory sounds as well as jugular vein distention. Therespiratory and heart rates were 35/min and 60 bpm, respectively.Agrade III/IV pansystolic murmur with the PMI on the tricuspidvalve, which could be heard on the left side, was detected. Sinustachycardia was revealed by electrocardiography. Rupture of thechorda tendineae of the tricuspid valve, pulmonary arteryregurgitation, pulmonary artery hypertension, tricuspid valveregurgitation, pulmonary artery, and right ventricular dilationwere also found in echocardiography. These findings wereconfirmed at post mortem examinations. On the basis of thefindings, chorda tendineae rapture of the tricuspid valve andright side heart failure due to primary pulmonary hypertensionwere diagnosed.

Some heavy metals are dangerous to health and there is rising concern about the quality of foodstuffs in some parts of the world. Fish, particularly Tuna fish, can concentrate huge quantities of several metals from water and they even play a significant role in human nourishment. OBJECTIVES: In this study, the concentrations of mercury and four trace metals in five brands of canned tuna samples purchased within the Tabriz city (Iran) were determined after digestion via the Association of Official Analytical Chemists techniques. METHODS: A total of 40 samples were collected. Lead and cadmium levels were determined via graphite tube atomic absorption spectrophoto-metry, whereas nickel and tin levels were determined via flame atomic absorption spectrophotometry, and mercury levels were determined via hydride generation atomic absorption spectro-photometry. RESULTS: The ranges obtained for the elements were Pb (0.01-0.242), Ca (0.0-1.05), Ni (0.113-0.589), Sn (0.05-0.9), and Hg (0.1-0.205) mg/kg wet weight. CONCLUSIONS: The results showed that tuna fabricated and marketed in Tabriz (Iran) had safe level of heavy metals that were lower than the averages of EC/FAO/WHO levels for these toxic metals.

The mucus layer plays an important role as an intermediate for the protection of the gut against acidic chyme, digestive enzymes, and pathogens; in addition, it acts as a lubricant and facilitator of nutrient transportation. Phytogenic compounds seem to promote intestinal mucus production. OBJECTIVES: The current study was conducted to investigate the effects of low and high levels of energy and amino acids in combination with turmeric, thyme, and cinnamon on chicken performance and expression of mucin 2 gene. METHODS: The eight experimental groups consisted of diluted and condensed diet with and without the addition of 5g/kg of each turmeric, thyme, and cinnamon to the diet. Chicken performance was recorded. Expression analysis of the mucin 2 gene was carried out by quantitative RT-PCR. RESULTS: Body weight gain, feed intake, FCR, and mortality rate were not affected by diets (p>0.05). A significant (p<0.05) reduction of the mucin 2 gene expression was observed in chickens fed by condensed diet; however, the expression increased by supplementation of turmeric, thyme, and cinnamon. CONCLUSIONS: These results, in addition to the function of herbs in increasing the activity of some enzymes which is possibly related to the mucin biological pathways, showed that the application of turmeric, thyme, and cinnamon could be useful in poultry diets. It appears that supplementation of turmeric, thyme, and cinnamon could increase mucin 2 gene expression in the small intestine, and this can improve intestinal digestive function and defense.