High performance thin layer chromatography analysis of deltamethrin residue on the impregnated bed nets during a leishmaniasis control program in Iran

The control of leishmaniasis, a tropical neglected disease, has been concern of Iranian health authorities due to the increasing number of cases during the last two decades. The objective of this study was to determine deltamethrine residue on the impregnated bed nets using HPTLC technique in a leishmaniasis control program in Iran. During this experimental study, a total of 130 small pieces of polyester netting were sewn to top, upper, and lower sides of some bed nets and then were impregnated with deltamethrin .The treated bed nets were distributed in Isfahan and Mashhad areas in April 2003. The samples were cut randomly after impregnation intervals. Deltamethrin was extracted using acetone from samples and the extract was applied for spotting onto plates. The plates were developed with n-hexane: ethyl acetate, 90+10[v/v], as a mobile phase in a Camage chamber. The qualifying of residue was observed in UV cabinet with lambda =254 nm wavelength. Data were analyzed using SPSS version 11.5. and Stata Version 8. A three way ANOVA was used to compare the means of deltamethrin residue in each area, group and measuring time. The Kruskal-Wallis test was used to compare the means of residue for each of these factors with the control separately. The retardation factor of deltamethrin was calculated 0.50 +/- 0.02. The residues of deltamethrin persisted well on impregnated nets at least for 15 weeks after impregnation. No significant difference could be detected in the loss of residue of insecticide in comparison to measuring times and positions of sampling pieces on the bed nets in these areas. Based on the results of the present study the use of HPTLC technique is recommended instead of other chromatographic methods for analysis of insecticide residue on the impregnated bed nets

Accuracy of gray-scale and color doppler sonography in diagnosis of hepatic hemangioma, hepatocellular carcinoma and liver metastasis

Distinguishing cavernous hemangioma from malignant neoplasms represents a diagnostic challenge. Knowledge of the entire spectrum of gray-scale ultrasonography [US] and color Doppler appearances of these tumors is important. The objective of this study was to determine the diagnostic accuracy of gray-scale US and color Doppler appearances of liver tumors. 88 patients with 93 focal hepatic lesions were prospectively studied with gray-scale and color Doppler US. The final diagnoses of the liver lesions as confirmed by pathology or 99mTc-red blood cell scintigraphy were 41 hemangiomas, 15 hepatocellular carcinomas [HCCs] and 37 metastases. 87.8% of hemangiomas and 66.7% of HCCs were hyperechoic, while 54.1% of metastases were hypoechoic. In lesions < 3 cm in diameter, the sensitivity and specificity of the hyperechoic pattern for differentiation of hemangioma from metastasis and HCC were 94.1% and 80.0%, respectively. They were higher than the lesions with a diameter ?3 cm [83.3% and 45.9%, respectively, both P=0.001]. Posterior acoustic enhancement was seen in 78% of hemangiomas [P<0.001], as compared to 24.4% in metastases and 13.3% in HCCs. 10 hemangiomas had an echogenic rim. The peripheral hypoechoic rim, named as the target sign, was seen in 37.8% of metastases, 26.7% of HCCs and 2.4% of hemangiomas [P<0.001]. Most hemangiomas [85.4%] showed no lesional blood flow, while most HCCs [80%] had both intraand peri-lesional vascularity [P<0.001]. There was intratumoral blood flow in 86.7% of HCCs. Lesional flow, whether intratumoral or peritumoral or both, was seen in all 14 patients with HCC while absence of the lesional flow was not noted in any of the HCCs. Most hemangiomas had no detectable blood flow in color Doppler US. Almost all HCCs had intra- and/or peri-tumoral vascularity in color Doppler sonography, so the probability of hepatocellular carcinoma is low in a hepatic mass without intra- or peri-lesional vascular blood flow. So these findings together with morphological criteria may help narrow down the differential diagnosis in certain clinical conditions

Reliability analysis of traffic noise estimation in highways of Tehran by Monte Carlo simulation method

This study was aimed to examine the reliability of traffic noise estimate and measurement techniques in highways of Tehran, capital of Iran. The multiple regressions showed that the traffic flow and the distance from the effective source position are the most important factors to estimate the L10 [1h]. Traffic flow, traffic composition in terms of heavy vehicles and traffic speed are identified as the key factors influencing the generation of traffic noise. The new equations for estimating the noise descriptor L10 was calibrated on the basis of noise measurements. The effects of the key factors on L10 [1h] were examined by the sensitivity analysis and it was found that traffic flow, distance from the effective source position, traffic composition and traffic speed had the most sensitivity on traffic noise, respectively. The probability distribution for each of the key factors was derived with the use of the survey data. The reliability of the traffic noise estimates was obtained from the combined probability distribution of the key factors by Monte Carlo simulation method. This study showed that there was no significant difference between estimated noise by calibrated CoRTN calculation of road traffic noise and measured noise level. The reliability analysis gives the traffic noise estimates with a particular probability or vice versa