Melanocytes in the testes of Eupemphix nattereri (Anura, Leiuperidae): Histological, stereological, and ultrastructural aspects

Ectothermic vertebrates have a well-developed system of melanin-containing cells, which localize in several organs and tissues and compose an extracutaneous pigmentary system. This research aimed at characterizing histological and ultrastructural patterns of pigmented cells in the testes of the anura Eupemphix nattereri (Steindachner, 1963), including the stereological and quantitative evaluation of this cell type in the gonads. Ten adult males were collected in Nova Itapirema, São Paulo, Brazil, and submitted to morphological studies with light and transmission electron microscopy. The testis presents a great number of large cells with many brown granules and long cytoplasmic processes. The pigmented cells found in the testis are structurally similar to melanocytes, characterized by large amounts of melanosomes. The cells may be in intimate contact with the same cell type, with myoid cells surrounded by a large amount of collagen fibers, Leydig cells, and next to fibroblasts. The distribution and amount of extracutaneous melanocytes is variable when other organs and membranes are analyzed, allowing the establishment of species-specific patterns for the extracutaneous pigmentary system.

Histology and morphometry of the testes of adult domestic cats (Felis catus)

Testicles of 30 mongrel cats were analyzed histologically and morphometrically, divided into three groups: G1 (1-2 years old), G2 (over 2 and up to 4 years old) and G3 (over 4 and up to 6 years old). After orchiectomy and histopathology, the morphometric parameters studied were: thickness of the tunica albuginea (72 mu m) and seminiferous epithelium (77.19 mu m), perimeter (53.81; 90.57 mu m), (54.80; 101.07 mu m); area (174.23; 494.55 mu m(2)), (176.68; 629.70 mu m(2)); maximum diameter (14.94; 28.02 mu m), (14.76; 31.66 mu m); minimum diameter (13.25; 21.92 mu m), (13.30; 24.52 mu m); and shape factor (index for regularity of the format) (1.36; 1.36), (1.39; 1.35) of the nucleus and cytoplasm of spermatogonia and Leydig cells, respectively. The results can be used for comparative studies and contribute knowledge concerning the height of the seminiferous epithelium, thickness of the tunica albuginea and size of spermatogonia and Leydig cells.

Glifosato: Propriedades, toxicidade, usos e legislação

This paper supplies a compact revision on the herbicide glyphosate physic-chemistry characteristic mains, including toxicity and valid Brazilian legislation for its use.

Testes size in leptodactylid frogs and occurrence of multimale spawning in the genus Leptodactylus in Brazil

Although rare, some anurans show multimale spawning. Herein we present data on testes mass relative to body mass for 11 leptodactylids and report multimale spawning in Leptodactylus chaquensis and Leptodactylus podicipinus. Testes mass averaged 4.13% of body mass for L. chaquensis and 0.75% for L. podicipinus. Testes size of both leptodactylid species with multimale spawning show that they are large and close to values recorded for rhacophorid frogs with multimale breeding (0.71-7.79%). Large testes size in frogs with multimale spawning supports the sperm competition hypothesis.

Análise retrospectiva da toxicidade de gotas otológicas, medicamentos tópicos nasais e orofaríngeos registrada na Grande São Paulo.

BACKGROUND: Retrospective analysis of human toxicity files involving topical medicines for treatment of upper airways diseases (eardrops, topical nasal medicines, lozenges, drops and sprays for oropharyngeal affections). METHODS: Thirty-four brands of eardrops, 48 of topical nasal medicines and 22 of tablets, lozenges and sprays for oropharyngeal affections were selected, from a total of 104 products available in Brazil. We analyzed the registries in the electronic database from the Poison Control Centre of São Paulo (CCI-Jabaquara), Brazil, for the period from January 1996 through December 2000. The cases related to selected pharmaceuticals were collected. RESULTS: 10,823 cases of human toxicity caused by medicines were voluntarily reported to CCI-Jabaquara. Topical medicines for treatment of upper airways diseases accounted for 291 cases (2.68%), from which 240 (82.5%) represented poisoning; 12 (4.1%) involved ear drops, 268 (92%), topical nasal medicines and 11 (3.9%), topical medicines for oropharyngeal affections. Among topical nasal medicines, vasoconstrictors predominated (233 cases), and among medicines for oropharyngeal affections, it was tetracaine (four cases). Considering age distribution, toxicity predominated significantly in children aged from 1 to 4 years (p=0.0003). The main causes of toxicity were: accidental intake of medicines (43%) and error in drug administration (14.8%). Hypereflexia and vomiting were the most frequent symptoms related to toxicity. CONCLUSIONS: There was significant incidence of systemic toxicity due to eardrops, topical nasal and oropharyngeal medicines in children 1 to 4 years-old, whose main cause was accidental intake of these medicines.

Testes de biocompatibilidade in vitro de duas formas comerciais do agregado de trióxido mineral

Recently, regular and white mineral trioxide aggregate (MTA) are being used in Dentistry as retrofilling materials. Genotoxicity and cytotoxicity tests form an important part of cancer research and risk assessment of potential carcinogens. Thus, the goal of this study was to examine the genotoxicity and cytotoxicity of regular and white MTA in vitro by the single cell gel (comet) assay and trypan blue exclusion test, respectively. Mouse lymphoma cells were exposed to two presentation forms of MTA at final concentrations ranging from 1 to 1,000 μg/mL for 3 h at 37°C. The results showed that both compounds tested did not produce genotoxic effects at all concentrations evaluated. Likewise, no statistically significant differences (p > 0.05) were observed in cytotoxicity. Taken together, our results suggest that regular and white MTA are not genotoxins and are not able to interfere in cellular viability as assessed by single cell gel (comet) assay and trypan blue assay, respectively.

Study of chromosomal and nucleolar aspects in testes of Nysius californicus (Heteroptera: Lygaeidae)

In Nysius californicus (family Lygaeidae, subfamily Orsillinae), a pest commonly known as the seed bug, the chromosome complement is 2n = 16 (12A + 2m + XY), testes are formed by seven seminiferous tubules covered by an orange-colored membrane, and spermatogenesis is cystic. At prophase, sex chromosomes are heteropycnotic and autosomes usually show a chiasma. At metaphase, sex chromosomes along with microchromosomes may be seen located at the center of a ring formed by the remaining autosomes. A characteristic specific of N. californicus was the presence of nucleolar material observed from the cystic cell to the completely differentiated spermatozoon. Variations in size, shape and location of the nucleolar material occur during this process, denoting a variable degree of activity in the different stages. ©FUNPEC-RP.

Toxicidade aguda do sulfato de cobre e do extrato aquoso de folhas secas de nim para o caramujo (Pomacea canaliculata)

Snails can become an environmental and economic problem, causing substantial losses. The objective of this work was to estimate the acute toxicity of copper sulfate pentahydrate (CuSO4.5H2O) and the aqueous extract of dried neem leaves on snails (P. canaliculata) under laboratory conditions. In order to estimate the lethal concentration 50% (LC (I)50;96h), snails were exposed to six increasing copper sulfate concentrations (0.0; 0.01; 0.03; 0.05; 0.07 and 0.1 mg L-1) and six increasing concentrations of aqueous extract of dried neem leaves 0.0; 100; 125; 150; 175 and 200 mL aqueous extract of dried neem leaves L-1 water, equivalent to (0.0; 1.18; 1.47; 1.77; 2.06 and 2.36 mg azadirachtin L -1), in triplicate and one control treatment in an entirely random delineation. Estimated LC (I)50;96h, of copper sulfate was 0.02 mg copper sulfate L-1, with a 0.01 mg L-1 lower limit and a 0.03 mg L-1 upper limit. Estimated lethal concentration 50% of the aqueous extract of dried neem leaves was 142.75 mL L-1, equivalent to 1.68 mg L-1 of azadirachtine, with a 130.89 mL L-1 (1.54 mg L-1) low limit and 155.69 mL L-1 (1.83 mg L -1) as the upper limit.

Avaliação de desempenho do microaspersor amanco em bancada de testes

The need for a rational use of water and supply of food for a growing world population have led to the development of research in the area of irrigation systems. Thus, some irrigation systems which join efficiency with low cost of material have been developed. Although some technical characteristics are provided by the manufacturers, tests are required to verify functioning of the system and uniformity of water distribution. Continuous research on uniformity, characteristics of the materials and design of water distribution systems is essential for system improvement. Therefore, the objective of this work was to evaluate the CV (manufacturer's coefficient of variation) of Amanco microsprinkler (1.0 mm light green nipple) using bench testing in the laboratory of Irrigation at UNESP - FCA campus of Botucatu-SP. Twenty-five microsprinklers in a sequential design were used in the tests. Three flow systems were tested as follows: a Coil system based on serial connected pipes; a Lateral system, the most common system in which secondary lines are fed by a main line; and a Mesh system used in the urban water supply. The results showed that 4.17% CVf met the production standards and the Lateral and Mesh systems were similar regarding outflow using bench testing. The Mesh system presented the highest mean value of outflow and the lowest range of variation.

Toxicidade de fármacos nitrofurânicos

During the structural designing of new drugs, it is possible predict the influence of specific chemical groups on pharmacological activity. Among these, the nitro group has potential antiparasitic activity, being present in many antimicrobial drugs, such as metronidazole, nitrofurazone, furazolidone, oxamniquine and chloramphenicol. Also, the introduction of the nitro group into a molecule can modify the physicochemical and electronic properties of the substance. Besides antimicrobial drugs, this group is also found in other drug classes, such as antiulcer, anti-inflamatory and anxiolytic. However, the use of the nitro group in drug design has encountered restrictions, due to the associated toxicity. This article is a review of the toxicity of nitrofuran compounds, as well the possible mechanisms involved and the strategy of latentiation by molecular modification to decrease their toxicity.

Testes de vigor para avaliação da qualidade fisiológica de sementesde Sebastiania commersoniana (Baill.) Smith & Downs.

The objective of this work was to evaluate the efficiency of different vigor tests to assess S. commersoniana seeds physiological quality during storage. Therefore, seeds were stored in cloth bags, plastic bags and glass containers for 531 days, both at room temperature and in a cold chamber. Periodically samples were taken and the following tests were conducted: standard germination, germination speed index, first count after germination, seedlings fresh and dry matter, electrical conductivity (imbibitions for 2 and 24 hours) and accelerated aging, in order to monitoring the seeds physiologic quality. Data were submitted to polynomial regression analysis, for each of the combination of packaging/storage condition. The results obtained led to the following considerations: a) the speed germination index and the accelerated aging test permitted a good evaluation of the seed-lots quality; b) the first count of germination did not allow any prediction about seed lots vigor; c) seedling fresh and dry matter did not discriminate among seed lots; d) electrical conductivity test after 2 h imbibitions was not adequate to evaluate the seed lots vigor and e) the electric conductivity test with 24 h imbibitions was more adequate to differentiate among seed lots, but with little efficiency to discriminate among seed lots with intermediate vigor or with low quality differences.

Estudo fitoquímico preliminar e bioensaio toxicológico frente a larvas de Artemia salina Leach. de extrato obtido de frutos de Solanum lycocarpum A. St.-Hill (Solanaceae)

The phytochemical profile of ethanolic extract of Solanum lycocarpum fruits was analyzed and preliminary toxicity tests were performed against brine shrimp larvae. The extract was subjected to preliminary phytochemical analysis to identify the main classes of secondary metabolites and tested against the larvae of A. salina to obtain the median lethal concentrations (LC50%). The phytochemical tests showed the presence of phenols, tannins, saponins, alkaloids and free steroids. The extract was fractionated with various solvents for toxicity testing against the larvae and the hydroalcoholic fraction showed considerable cytotoxicity (CL50% = 285.546 g/mL).

Testes de envelhecimento acelerado e de condutividade elétrica em sementes de Dictyoloma vendellianum A. Juss.

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Determinação da toxicidade do selênio por meio de análises hematológicas em Oreochromis niloticus

Selenium (Se) is described as an essential micronutrient and participates in different biological functions, as the antioxidant defense systems maintenance and regulation. However, when in high concentrations, Se may cause toxic effects as well as hematological changes in fish. The aim of the present study was to determine the toxicity of selenium in the form of sodium selenate (Na 2Se 6+O 4) in Oreochromis niloticus based on hematological parameters, after exposure to different concentrations (0.01, 0.14 and 1.4 mg Se 6+ L -1). The erythrocytic and leukocytic series were examined over 14 days at intervals of 0, 3, 5, 7,10 and 14 days. The erythrocytic series showed significant alterations in the first 7 days, including the control group. Neutrophils and monocytes showed variations in the first 3 days at a concentration of 1.40 mgSe 6+ L -1 characterizing an acute response. The total number of leukocytes was different in relation to time zero on all Se concentrations. The thrombocyte count also differed statistically from time zero and control in the first 3 days at 0.14 mgSe 6+ L -1. These results indicate that different concentrations induce an acute response with diminution of total leukocytes, neutrophilia, monocytosis and thrombocytosis.