Cytogenetic and molecular biomonitoring of agricultural workers exposed to pesticides in Brazil

The use of agricultural chemicals without correct protection may lead to alterations in the genetic material of cells and the possible development of several types of tumors. The individual genetic variability in the enzymes which metabolize agricultural chemicals is also involved in this process, such as when the enzymes are not efficient in the detoxifying process of the organism, the metabolic subproducts accumulate, contributing to the tumorigenic process. Cytogenetic monitoring was carried out on a group of 20 male workers occupationally exposed to a mixture of pesticides in the town of S?o Jer?nimo da Serra, PR (Brazil). Student's t = test and Wilcoxon's test showed, respectively, that there was no significant difference between the chromosome aberration frequencies between the exposed and control groups and between the paired individuals. However, there was a significant difference in the two analyses regarding the mitotic index of the sampled individuals. Smoking and time of exposure to agricultural chemicals did not influence the cytogenetic responses obtained, but the mitotic index of the control individuals was higher than that of the exposed individuals from the different age groups. The GSTM1 gene polymorphism was 33% null. When statistical tests were carried out to assess the relationship of the GSTM1 genotypes with the chromosome aberrations and mitotic indexes, there was no significant difference. The CA frequencies found in this study were low, making it difficult to associate it with the GSTM1 gene polymorphism. Teratogenesis Carcinog. Mutagen. 20:161-170, 2000.     

Immunocytochemical identification and analysis of the diffuse bipolar cell type DB6 in macaque monkey retina

The distribution and morphology of CD15‐immunoreactive bipolar cells were studied in the retina of macaque monkey. Labelled cells have a large dendritic tree contacting several cones and a narrowly stratified axon terminal that ends deep in the inner plexiform layer, close to the ganglion cell layer. The morphology of the labelled cells corresponds to that of the diffuse bipolar cell type named DB6 by Boycott & Wässle (1991; Eur. J. Neurosci., 3 ,1069). We conclude that CD15 is a marker for DB6 bipolar cells, enabling the quantitative analysis of the distribution and connectivity of this diffuse bipolar cell type.     

Guess what! SALT - related B-cell lymphoma presenting as a xanthomatous infiltration of the neck

A 37-year-old man without previous medical history working as a lock keeper was seen in our unit for a progressive painless subcutaneous flesh coloured infiltration of the lower anterior area of the neck growing slowly over 5 months. Clinical cutaneous findings showed a non pruriginous yellowish papulonodular eruption mimicking xanthomas (Figs. 1 and 2). No other clinical abnormalities were found. A cutaneous biopsy specimen was performed. Histopathological examination revealed, under a normal epidermis, a dense lymphoplasmocytoid infiltrate involving the dermis with periadnexal and perivascular reinforcement (Figs. 3 and 4).     

Coronary anastomotic devices: Theory and patented ideas on micromechanical fastening

Coronary anastomotic devices are being designed to reduce the laborious, complex suturing approach to endoscopic coronary surgery. An anastomotic device should be safe and reliable, it should allow full view of the vessel parts to be bonded, it must provide a simple and rapid deployment, and should be hemodynamically adequate. Three anastomotic device categories found in the (patent) literature are discussed that use micromechanical fastening techniques. First, devices using individual bonding elements; second, devices using bonding elements anchored to extraluminal frames; third, devices using an internal frame, often a stent-like structure. Anastomotic devices described in the (patent) literature to date fail to meet all requirements for endoscopic coronary application.     

Acitretin is converted to etretinate only during concomitant alcohol intake

BACKGROUND: Acitretin has replaced etretinate in the treatment of various disorders of keratinization due to a considerably shorter terminal half-life. Possible esterification of acitretin to etretinate in the presence of ethanol has been reported. OBJECTIVES: To determine the plasma concentrations of etretinate as a metabolite in patients with various disorders of keratinization after multiple acitretin dosing, and to assess the influence of alcohol consumption using a questionnaire. In addition, to study the influence of alcohol consumption on the risk of metabolic formation of etretinate. PATIENTS/METHODS: Eighty-six acitretin (Neotigason(R), Roche)-treated outpatients from three centres provided pre-dose (trough) samples for determining plasma concentrations of acitretin and its metabolites 13-cis-acitretin and etretinate. Patients received acitretin doses of between 0.1 and 1.3 mg kg-1 daily. The concentrations of etretinate, acitretin and 13-cis-acitretin were determined by reverse-phase high-performance liquid chromatography. RESULTS: Of the 86 patients, 30 had detectable plasma etretinate levels. No etretinate was found in 20 patients who reported that they never drank alcohol, while etretinate was found in all 16 patients with an average weekly alcohol consumption of > 200 g ethanol, corresponding to about 15 U (1 U equals half a pint of standard beer or a wine glass of non-fortified wine). Etretinate was detected in 14 of 50 patients with a moderate weekly alcohol intake of up to 200 g ethanol. A trend linking higher alcohol intake with both higher risk of etretinate formation and higher etretinate levels was observed. The study also revealed that the ethylesterification only relates to acitretin (13-trans-) and not to the main metabolite 13-cis-acitretin, although the latter compound showed higher plasma trough concentration levels at steady state. CONCLUSIONS: Owing to the teratogenic potential and possible side-effects of oral retinoids, fertile women especially should be informed about the importance of strict alcohol abstinence during treatment and for at least 2 months after stopping therapy. In case of non-compliance with alcohol abstinence a post-therapy contraceptive period of 2-3 years should be recommended.     

Characteristics of haemopoietic progenitor cells related to CD34 epitope class expression

Haemopoietic progenitor cells (HPCs) express the CD34 molecule, a heavily glycosylated transmembrane protein displaying three main classes of epitopes. The CD34 epitope class expression may vary between different subsets of HPCs. The aim of this study was to characterise the subsets of HPCs expressing CD34 class II and III epitopes. The cells were studied for coexpression of activation-, lineage- and adhesion-associated molecules, and their clonogenic ability and morphological features were examined. CD34+ HPCs expressing class III epitopes outnumbered those expressing class II. Class III expressing HPCs were enriched for CFU-GM and BFU-E and cells coexpressing CD13, CD33, c-kit and CD71 compared to class II expressing HPCs. CD34+ cells exclusively expressing class III epitopes uniformly displayed CD13 and CD33; they had a high clonogenic capacity and morphological characteristics of promyelocytes and myelocytes. The data show that class III epitopes are distributed more broadly on CD34+ HPCs than are class II epitopes, and that lack of class II epitopes is confined to CD34+ HPCs at a late stage of myeloid differentiation. The higher number of class III expressing HPCs coexpressing c-kit and CD71 suggests that these cells exhibit a higher proliferative or differential potential than do HPCs expressing class II epitopes.