Assessment of DNA damage in workers occupationally exposed to pesticide mixtures by the alkaline comet assay

The potential genetic hazard of pesticides to human beings is of great concern in occupational and environmental settings because of the widespread use of these chemicals for domestic and industrial applications. Various studies have revealed a significantly elevated risk for particular tumours in humans exposed to some pesticides. Results from the biological monitoring or cytogenetic methods for the detection of health risks to pesticides have given both positive and negative results of mutagenicity. In this study DNA damage in peripheral lymphocytes of 33 pesticide-exposed workers employed in the municipality of Ankara (Turkey) for at least 1 year was examined by alkaline single-cell gel electrophoresis, the 'comet' technique. Results were compared with those from 33 controls of comparable age, sex and smoking habits, which were not occupationally exposed to pesticides. Work characteristics of the exposed workers and the use of personnel protective measures were also investigated. The DNA damage observed in lymphocytes of the workers was significantly higher than that in the controls ( P<0.001). The observed DNA damage was found to be significantly lower ( P<0.001) in workers applying some of the necessary individual safety protections during their work. Cigarette smoking was not related to increases in DNA damage; also, no significant association was found between the duration of occupational exposure to pesticides and the degree of DNA damage.     

Proboscis lateralis: radiological evaluation

Proboscis lateralis is a rare craniofacial anomaly. It consists of a soft, trunk-like process that originates from the medial portion of the orbital roof and it may be accompanied by a number of facial and cerebral anomalies. The characteristics and relationship of the lesion to adjacent structures should be known, and associated anomalies should be detected before surgical correction. The patient should undergo neuroimaging studies besides clinical evaluation to obtain this information in detail. The neuroimaging findings of only one previous case are available in the literature. We report two cases of proboscis lateralis evaluated by CT and MRI before corrective surgery.     

ABCC8 (SUR1) and KCNJ11 (KIR6.2) mutations in persistent hyperinsulinemic hypoglycemia of infancy and evaluation of different therapeutic measures

Persistent hyperinsulinemic hypoglycemia of infancy (PHHI) can occur as a result of mutations in the subunits that form the ATP-sensitive potassium channel (K+ATP) in pancreatic beta-cells which play a major role in modulating insulin secretion from the beta-cells. Mutations have been shown in the genes for these subunits, namely for the plasma membrane sulfonylurea receptor (SUR1), ABCC8, and its associated inwardly rectifying potassium channel (KIR6.2) KCNJ11. Drugs which act on K+ATP channels, such as diazoxide, seem to need intact ABCC8 to be able to show their effects. Thus, it would be desirable to know the exact locus of the abnormality in the beta-cell to be able to choose the right therapeutic agent or to perform early pancreatectomy. The aim of this study was to search for the correlation between the mutations of the K+ATP channel and the outcome of therapeutic measures in patients with PHHI followed for a duration of 4 months to 7.3 years. Thirteen patients (5 F, 8 M) with PHHI with a median age of 2.5 months (8 days-12.1 years) were included in the study. Therapy for PHHI was initiated either with diazoxide (n = 9) or with calcium channel blocker (n = 4) as the agent of first choice. Three patients unresponsive to drugs underwent 95% pancreatectomy. Mutation analysis was performed by polymerase chain reaction (PCR) and single strand conformation polymorphism (SSCP) in DNA samples extracted from patients' peripheral leukocytes. The PCR products were directly sequenced. Screening of ABCC8 and KCNJ11 for mutations revealed abnormalities in the ABCC8 gene in three patients out of 13: homozygosity for the 155del1 mutation, compound heterozygosity for T267-->G/A4612-2-->G, and compound heterozygosity for G4310-->A/ R1494Q. No mutations in the KCNJ11 gene were identified. Of the three patients who underwent pancreatectomy, two had identified mutations and one did not have any known mutation. In two patients in whom hyperinsulinism recurred after surgery and in the rest of the children, therapy with either diazoxide or calcium channel blocker proved to be effective in controlling hypoglycemia over the follow-up period. Thus it may be concluded that mutations in the ABCC8 gene were not predictive of the response to drugs. Unidentified mutations in the K+ATP channels other than those screened or other functional abnormalities in these channels may account for the different therapeutic responses.     

A two parameter Weibull distribution method for predicting cations in the ground water of Cauvery delta of Tamilnadu

A two parameter Weibull distribution model was applied to evaluate the quality of ground water collected from 50 wells in four regions (CSB, VSB, RCA, NDA) of Thanjavur district. The data of the cations (Ca, Mg, K, Na) and EC were used to predict the ground water quality. The shape (a) and scale (b) along with mean and percentile were zoned. A hybrid approach of the Weibull distribution model was done to estimate the mean. This hybrid approach may be used to predict and forecast the ground water quality. From the study the cationic parameters in the wells were not uniform which may be attributed to contamination either by surface flow or sea water.     

MRI of neurologic complications in end-stage renal failure patients on hemodialysis: pictorial review

End-stage renal disease patients who have been on long-term hemodialysis tend to develop central nervous system complications. The most common neurologic complications in this patient group include white matter changes, cerebral atrophy, osmotic demyelination syndrome, dialysis encephalopathy, hypertensive encephalopathy, intracranial hemorrhage, infarct, sinus thrombosis, and infection. Clinical evaluation of these patients is somehow complicated and MRI is important before establishment of the therapy. The purpose of this article is to illustrate the range of MRI findings of neurologic complications in end-stage renal failure patients on hemodialysis with etiologic factors. Received: 7 April 2000 Revised: 28 August 2000 Accepted: 28 August 2000     

Diffusion abnormalities of the uncinate fasciculus in Alzheimer’s disease: diffusion tensor tract-specific analysis using a new method to measure the core of the tract

Introduction Our aim was to determine diffusion abnormalities in the uncinate fasciculus (UF) in Alzheimer’s disease (AD) by diffusion tensor tractography (DTT) using a new method for measuring the core of the tract. Methods We studied 19 patients with AD and 19 age-matched control subjects who underwent MRI using diffusion tensor imaging (DTI). DTT of the UF was generated. The mean diffusivity (MD) and fractional anisotropy (FA) of the core of the tract were measured after voxelized tract shape processing. Student’s t-test was used to compare results between patients with AD and controls. Intraobserver correlation tests were also performed. Results FA was significantly lower (P < 0.0001) in the UF of patients with AD than of controls. There was no significant difference in MD along the UF between the two groups. Intraobserver reliability (intraclass correlation coefficient) for the first and second measurement was r > 0.93 for measured FA and r > 0.92 for measured MD. Conclusion Our results suggest that FA reflects progression of AD-related histopathological changes in the UF of the white matter and may represent a useful biological index in monitoring AD. Diffusion tensor tract-specific analysis with voxelized tract shape processing to measure the core of the tract may be a sensitive tool for evaluation of diffusion abnormalities of white matter tracts in AD.