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The morphology of horizontal cells was studied in the retina of dichromatic capuchin monkeys, Cebus apella. The cells were labeled with the carbocyanine dye, 1,1',dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI), and the labeling was then photoconverted to a stable product by using a diaminobenzidine reaction. The sizes of cell body, dendritic field, and axon terminal, as well as the number of dendritic clusters and cone convergence, were measured at increasing distance from the fovea. Three distinct morphological classes of horizontal cells were identified. Their dendritic and axonal morphology resembles those of H1, H2, and H3 cells described in trichromatic primates. The size of the cell bodies, dendritic fields, and axon terminals of all cell classes increases towards retinal periphery. H3 cells have larger dendritic fields and more dendritic clusters than H1 cells. All labeled horizontal cells located in selected patches of retina were further analyzed to quantify the differences between H1 and H3 cells. H1 cells have smaller dendritic field area, smaller total length of primary dendrites, more dendritic branching points, and larger fractal dimension than H3 cells. We have distinguished H1 and H3 cells based solely in morphological criteria. Their physiology should be further analyzed with detail, but their presence in both dichromatic and trichromatic primates suggests that neither of them have a specialized role in the red-green color opponent channel of color vision., (Copyright 2002 Wiley-Liss, Inc.)

In the cacao-growing region in the southern part of the state of Bahia, the organochlorine insecticides, mainly gamma-benzene hexachloride (BHC) and dichlorodiphenyltrichloroethane (DDT), have been used for about 40 years on cacao crops and in public health programs for control of the insect vectors of different diseases, especially malaria. This paper presents the results of tests performed on 127 persons, all males, between the ages of 15 and 52 years, divided into eight groups as follows: three groups consisted of persons occupationally exposed to 1.5% BHC, that is, technical hexachlorocyclohexane (HCH); two groups consisted of individuals who had had occasional contact with the products or worked in areas near those in which they were used; two groups were appliers of DDT, and the last group--the control group--consisted of 50 individuals who had had no history of occupational exposure to insecticides. All the participants underwent testing to determine the parameters of biochemistry, hematology, and organochlorine insecticide residues in the blood. It was found that improper handling of the products and failure to use individual protective equipment, together with longer time of exposure, significantly increased the rates of GOT and GPT in the appliers of DDT and technical HCH, and in the latter the rates of alkaline phosphatase, albumin, and cholesterol were also found to be higher. In view of the high morbidity among pesticide appliers in agriculture and public health campaigns, it is important to institute programs to teach these workers to avoid contamination of their persons and of the environment by developing good hygiene habits, using individual protective equipment, and correctly handling the products. Rural workers and public health authorities must become aware of the importance of protective equipment, periodic health examinations, and reduced environmental pollution in order to lessen occupational risks of field workers and promote improved conditions of life for the rural population at large.

Sixteen patients acutely poisoned with aldrin were examined to evaluate a possible correlation between serum aldrin and dieldrin levels and clinical complaints. The patients were classified as having mild (N = 8), moderate (N = 5) or severe (N = 3) poisoning according to clinical symptoms. Concentrations of less than 20 micrograms/l were usually associated with mild poisoning, which involved complaints such as nausea, vomiting and epigastric pain, whereas concentrations of 100 to 200 micrograms/l were considered to represent moderate intoxication and were associated with nausea, vomiting, epigastric pain, headache, dizziness, and convulsions. Severe or fatal cases were associated with levels above 700 micrograms/l. Taken together, these results suggest that serum aldrin and dieldrin levels can be used as indicators of clinical prognosis after acute poisoning with these insecticides and that convulsions could suddenly occur even in the absence of prodromal signs or symptoms.

In the attempt to correlate clinical findings with serum levels of aldrin, sixteen patients were followed-up after acute intoxication by this agent. Eight of them, males and females, aged from 1 to 37 years, presented no or light symptoms (some discomfort and nausea). The serum of one of these patients was found to contain 16.6 ppb of aldrin and that of another, 1.41 ppb of dieldrin. A group of five patients, aged from two to 30 years, showed symptoms of moderate severity, reporting nausea, vomiting, drowsiness, dyspnea, sweating, mild jerking, rise in blood pressure and convulsions. Of these cases, two were accidental and three were attempted suicides, the majority achieving complete recovery within 24 hours. Serum levels of aldrin were between 6.98 ppb and 26.3 ppb and of dieldrin between 82.00 and 314.18 ppb. We found three severe cases, aged from 21 to 35 years, two attempted suicides and one occupational case. Two of these patients died and one of them presented hypothermia, coma, absence of reflexes and generalized convulsions, and another presented abdominal pain, paleness, sweating, cold extremities, dyspnea, hyperthermia and generalized convulsions. In the first one that died the serum levels were: of aldrin 30.00 ppb and of dieldrin 720 ppb. In the other levels of 747.3 ppb of aldrin and 1,314.00 ppb of dieldrin were found. The third had less serious symptoms and presented serum levels of aldrin of 31.05 ppb and of dieldrin 147.11 ppb.(ABSTRACT TRUNCATED AT 250 WORDS)