Sample Matrix Interference in Immunoassays for Organochlorine Residues in Plant-derived Foods and Some Strategies for Their Removal

Immunoassays for two groups of organochlorine insecticides, cyclodienes (endosulfan and heptachlor) and DDT were applied to the analysis of a diverse range of plant-derived foods. Water-miscible solvent extracts of high-moisture, low-fat foods such as cauliflower, cabbage, green and red blue grapes and tomato caused little or no interference with the assays, enabling methanol or acetonitrile extracts of the foods to be analysed directly by immunoassay, after dilution in assay buffer. Reasonable recoveries of spikes of these pesticides were obtained by direct analysis of extracts of spiked commodities, with reliable detection down to 0.025 mg kg^-1 heptachlor or endosulfan and 0.1 mg kg^-1 DDT in the commodities. Acetonitrile extracts of milk could also be analysed directly for DDT. In contrast, extracts of low moisture, non-fatty (rice) and fatty (cottonseed) food commodities interfered appreciably with the assays, reducing assay colour and detection sensitivity. Some simple cleanup methods were developed to remove interference and enable detection of spiked organochlorines in these foods. Extracts of coloured foods, such as tea, coffee and spinach caused similarly major interference in the assays, and a number of simple clean-up methods were ineffective in removing interference. However, use of an immunoaffinity chromatography method for cyclodienes enabled quantitative recoveries to be obtained in extracts of several of these foods when analysed by either ELISA or gas chromatography. Direct analysis was suited for screening purposes but immunoaffinity chromatography results were more quantitative. These results indicate that ELISAs can be applied under developing country conditions to a range of diverse foods, but that cleanup strategies need to be tailored to different types of foods.     

Th1 cell development induced by cysteine proteinases A and B in localized cutaneous leishmaniasis due to Leishmania guyanensis

The cysteine proteinases CPA and CPB from Leishmania major induced Th1 responses in patients with leishmaniasis due to Leishmania guyanensis. Furthermore, cysteine proteinases induced neither interleukin 4 (IL-4) nor IL-13 and low levels of IL-10 in controls and patients. The results suggest that CPs would be quite good candidates for a vaccine against different Leishmania species.     

In vitro leishmanicidal activity of 3-substituted isocoumarins: synthesis and structure activity relationship

Twenty-five 3-substituted isocoumarins were synthesized using cutting edge microwave-assisted technology in high yields. The syntheses of different isocoumarins were carried out in a single step by the direct condensation of homophthalic acid with aryol and acyl chlorides under the solvent-free conditions without any solid support. The structures of all the synthesized compounds were characterized using different spectroscopic techniques including UV, IR, (1)HNMR and EIMS and purity was confirmed by CHN analysis. All the synthesized compounds were tested for in vitro leishmanicidal activity. Compounds 3a, 3b, 3g, 3l, 3m, 3r, 3t, 3w, 3x, and 3y displayed potential in vitro leishmanicidal activity with IC(50) values in the range of 0.56-84.38 microg/ml, whereas standard inhibitors amphotericine B have IC(50) = 0.24 microg/ml. The compounds 3b, 3g, 3m, 3t, 3w, 3x, and 3y having IC(50) values 27.86, 28.88, 36.49, 34.37, 28.68, 0.89 and 0.56 microg/ml, respectively, were most active among the present series while remaining others were found less active. The compound 3x and 3y can act as potential lead molecules for further development of isocoumarin-based new drugs for the treatment of leishmaniasis.     

Renal angiomyoadenomatous tumor: morphologic, immunohistochemical, and molecular genetic study of a distinct entity

We present a series of a distinct tumorous entity named renal angiomyoadenomatous tumor (RAT). Five cases were retrieved from the consultation files of the authors. Histologic and immunohistochemical features were evaluated. Sequencing analysis of coding region of the VHL gene was carried out in all cases. The tumors were composed of admixture of an epithelial clear cell component and prominent leiomyomatous stroma. Epithelial cells formed adenomatous tubular formations endowed with blister-like apical snouts. All tubular/glandular structures were lined by a fine capillary network. The epithelial component was positive for epithelial membrane antigen, CK7, CK20, AE1-AE3, CAM5.2, and vimentin in all cases. In all analyzed samples, no mutation of the VHL gene was found. RAT is a distinct morphologic entity, being different morphologically, immunohistochemically, and genetically from all renal tumors including conventional clear cell carcinoma and mixed epithelial and stromal tumor of kidney.     

Aggressive pilomatrixoma

We report a case of aggressive pilomatrixoma (PMX) in a 25‐year‐old male who presented with swelling in left supraclavicular region of 2‐month duration. A diagnosis of small round cell tumor was suggested on fine‐needle aspiration cytology. He underwent wide excision of the mass. On histomorphological examination, a diagnosis of aggressive PMX was made. The swelling recurred after 3 months of complete resection and on examination had similar morphological features. The case is presented because of the potential diagnostic difficulties on cytological examination and rare occurrence of aggressive variant of PMX. Diagn. Cytopathol. 2014;42:906–911. © 2014 Wiley Periodicals, Inc.     

The N-terminal region containing the zinc finger domain of tobacco streak virus coat protein is essential for the formation of virus-like particles

Tobacco streak virus (TSV), a member of the genus Ilarvirus (family Bromoviridae), has a tripartite genome and forms quasi-isometric virions. All three viral capsids, encapsidating RNA 1, RNA 2 or RNA 3 and subgenomic RNA 4, are constituted of a single species of coat protein (CP). Formation of virus-like particles (VLPs) could be observed when the TSV CP gene was cloned and the recombinant CP (rCP) was expressed in E. coli. TSV VLPs were found to be stabilized by Zn²⁺ ions and could be disassembled in the presence of 500 mM CaCl_2. Mutational analysis corroborated previous studies that showed that an N-terminal arginine-rich motif was crucial for RNA binding; however, the results presented here demonstrate that the presence of RNA is not a prerequisite for assembly of TSV VLPs. Instead, the N-terminal region containing the zinc finger domain preceding the arginine-rich motif is essential for assembly of these VLPs.     

Starting dose of levothyroxine for the treatment of congenital hypothyroidism: a systematic review

OBJECTIVE: To determine the effect of levothyroxine sodium starting dose on cognitive development, growth, or behavior in children with congenital hypothyroidism identified by neonatal screening. DESIGN: Systematic review of cohort studies. Two analyses were performed: a between-study comparison of mean starting dose with mean developmental score and an analysis of the within-study effects of starting dose on cognitive development, growth, or behavior. RESULTS: The between-study comparison (14 cohort studies based on 1321 patients) found that the standardized mean IQ or developmental quotient scores ranged from 90 to 115 but were not associated with the mean starting dose of levothyroxine (P =.48). The within-study comparison of 4 cohort studies (based on 558 patients) that reported the effect of the starting dose of levothyroxine on cognitive development found no consistent effects. There was weak evidence for an effect of starting dose on growth (1 study) and on behavior problems (1 study). CONCLUSIONS: The evidence for an effect of starting dose of levothyroxine on cognitive development, growth, or behavior is too weak to justify recommendations in favor of high- or standard-dose regimens. More reliable information, based on a randomized controlled trial of starting dose or a meta-analysis of the individual patient data currently available, is required to inform treatment policies.     

Expression of Wnt-signaling pathway proteins in intraductal papillary mucinous neoplasms of the pancreas: a tissue microarray analysis

Abrogation of the Wnt-signaling pathway is implicated in the carcinogenesis of several malignancies, especially colorectal cancer where up to 90% of cases are thought to have impaired Wnt signaling. It is less frequently involved in conventional ductal pancreatic adenocarcinoma. This pathway has not been explored in intraductal papillary mucinous neoplasms (IPMNs) of the pancreas previously and formed the basis of this study. A tissue microarray of 18 cases of IPMN was stained for proteins involved in the Wnt pathway: adenomatous polyposis coli (APC), pan-beta-catenin, axin 2, glycogen synthase 3alphabeta and 3beta, c-myc, E-cadherin, and cyclin D1. The IPMNs were classified as 8 adenomas, 3 borderline, and 7 cases with carcinoma in situ and/or invasive carcinoma, occurring in 13 females, and the overall age range was 45 to 73 years. Immunohistochemical analysis showed nuclear beta-catenin staining in 7 (39%) of the 18 cases. The cases with nuclear beta-catenin localization included 1 adenoma, 2 borderline IPMN, and 4 carcinomas in situ and/or invasive carcinomas. Seven cases showed absence of APC immunostaining and these included 4 cases with nuclear beta-catenin localization. Fourteen cases displayed marked diffuse up-regulation of c-myc protein, and 12 cases also showed diffuse cyclin D1 protein overexpression. E-cadherin expression was intense and membrane in location (comparable to normal tissue) in 6 of 8 adenomas (no tissue was available in 1 case). Decreased E-cadherin staining was noted in 8 cases where tissue was available for assessment. There was progressive decrease in membrane staining of E-cadherin in 2 of 3 borderline lesions, 1 of 2 carcinomas in situ, and 4 of 5 invasive carcinomas. All other immunostains were either normal in distribution or did not show any correlation with beta-catenin or clinicopathologic parameters. In conclusion, 7 (39%) of 18 cases of IPMN in this study demonstrated abnormal localization of beta-catenin, 4 of which also lacked APC expression. Of 5 carcinomas arising in IPMN, 4 displayed a decrease in E-cadherin expression. There was also a trend for the higher grades of IPMN to show nuclear localization of beta-catenin. These findings suggest that a proportion of cases of IPMN may show abnormalities in the Wnt-signaling pathway with consequent altered expression of downstream related proteins.     

Diabetes mellitus in Asian Indian children and adolescents

AIM: To study the clinical and metabolic profile of type 1 and type 2 diabetes mellitus in children and adolescents in a South Asian population. RESEARCH DESIGN AND METHODS: Sixty children were recruited. They were divided into three groups: Group I--type 2 diabetes mellitus (DM2), Group II--type 1 diabetes mellitus (DM1), and Group III--healthy controls. The clinical history and biochemical parameters (HbA1c, serum insulin, C-peptide, triglycerides, total cholesterol and HDL-cholesterol) were recorded. Homeostasis model assessment for insulin resistance (HOMAIR) and quantitative insulin sensitivity check index (QUICKI) were calculated. RESULTS AND CONCLUSIONS: Children and adolescents with DM2 had a significant family history of DM and clinical features of insulin resistance, including increased body mass index, waist:hip ratio and acanthosis nigricans. They also had decreased insulin sensitivity together with dyslipidemia of metabolic syndrome, i.e. high triglyceride, high total cholesterol and low HDL-cholesterol. The presence of these predictors of cardiovascular disorders is known to contribute to morbidity and mortality. Hence, DM2 needs to be recognized early in Asian Indian children.