Morphometric and morphological analysis of neuromuscular junction alterations in the denervated rat diaphragm

The morphological and structural alterations that occur in the neuromuscular junctions of the denervated rat diaphragm were studied. Fifteen adult male albino rats (Rattus norvegicus) aged about 60 days and with a mean weight of 200 g were used. Chronically denervated diaphragms were obtained and the animals were sacrificed after 4, 8 and 12 weeks of denervation. The left antimere of the diaphragm was denervated by section of the phrenic nerve and the right antimere was used as control. Each antimere was divided into three fragments: one was used for histochemical (nonspecific esterase) and morphometric study of neuromuscular junctions, and the other two were used for transmission and scanning electron microscopy (SEM) analysis. Histochemical analysis of the diaphragm neuromuscular junctions after denervation showed only small changes in junction morphology. However, these junctions became smaller and elongated and presented less visible contours with increasing time of denervation. Ultrastructural analysis of neuromuscular junctions after 12 weeks showed more or less organized junctional folds on the muscle fiber surface. The junctional cytoplasm exhibited important alterations such as mitochondrial degeneration and the presence of numerous filaments. SEM revealed the presence of deep primary synaptic grooves with peripheral excavations which housed the nerve terminal boutons and exhibited internally the secondary synaptic clefts present among the junctional folds of the sarcolemma. This study showed that some of the morphological changes demonstrated in other denervated striated skeletal muscles are not repeated at the same intensity or in the same temporal pattern in the rat diaphragm.

Laryngeal and voice disorders in patients with gastroesophageal symptoms. Correlation with pH-monitoring

OBJETIVO: Investigar as alterações laríngeas e vocais em pacientes com sintomas de refluxo gastroesofágico e correlacioná-las com o exame de phmetria. MÉTODOS: Estudo prospectivo que incluiu os pacientes atendidos nos ambulatórios de Distúrbios da Voz da Faculdade de Medicina de Botucatu no período de cinco anos com sintomas vocais e gastroesofágicos. Os pacientes foram submetidos à videolaringoscopia, às análises vocais perceptivo-auditivas, a analise vocal acústica computadorizada e ao exame de pHmetria de dois canais com monitorização durante 24 horas. RESULTADOS: Foram incluídos 57 pacientes (entre 21 a 65 anos; 45 mulheres e 12 homens). Desses, 18 apresentavam pHmetria normal (31,6%) e 39 alterada (68,4%). As videolaringoscopias registraram diversas lesões laríngeas tanto nos pacientes com pHmetria normal como alterada, sendo mais relevantes neste último grupo, destacando-se a paquidermia posterior. As avaliações vocais perceptivo-auditivas identificaram alterações vocais de diversas intensidades em ambos os grupos, mais importantes nos pacientes com pHmetria alterada. Todos os parâmetros acústicos, exceto Fo, mostraram-se alterados em ambos os grupos, quando comparados aos controles. CONCLUSÕES: Alterações vocais perceptivas e acústicas, e lesões laríngeas foram registradas tanto nos pacientes com phmetria normal como alterada, sinalizando para a importância da historia clínica e dos achados videolaringoscópicos no diagnóstico das laringites ácidas.

Estudo epidemiológico de disfonias em crianças de 4 a 12 anos

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Histology and ultrastructure of pericardial cells of Scaptotrigona postica latreille (Hymenoptera, Apidae) in workers and queens of different ages

The paper presents a study of the pericardial cells of Scaptotrigona postica an eusocial Brazilian stingless bee. Light and electron microscopy was used in a comparative study on workers and queens of different ages, exerting different functions in the colony. The pericardial cells are found only in the peticardial sinus, mainly in groups around the dorsal vessel. Each cell is enclosed by the basal membrane and its peripheral region is characterized by folds of the plasma membrane, which form canals and loops. The points where the plasma membrane folds is frequently closed by diaphragms, that along with the basal lamina form a barrier to substances from hemolymph. Along the membrane limiting the canals and loops, an intense endocytic activity through coated vesicles takes place indicating a selective absorption of hemolymph components. In older individuals, workers or queens, the cells exhibit larger quantities of cytoplasm inclusions, heterogeneous vacuoles containing the final products of intracellular digestion, and autophagic vacuoles with concentric membranous structures. The pericardial cells general morphology is in accordance with the role in processing metabolites captured from hemolymph and storage of indigested residues. (C) 2006 Elsevier Ltd. All rights reserved.

Azadirachta indica A. Juss (neem) induced morphological changes on oocytes of Rhipicephalus sanguineus (Latreille, 1806) (Acari: Ixodidae) tick females

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The functional morphology of the metapleural gland of the leaf-cutting ant Atta laevigata (Formicidae: Attini)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A comparative cytochemical study of the dufour gland in the eusocial bee Apis mellifera Linne, 1758 and Melipona bicolor Lepeletier, 1836

Dufour glands of Apis mellifera and Melipona bicolor were studied under light and transmission electron microscopy, using the cytochemical techniques of mercury bromophenol blue for protein detection, imidazole-buffered osmium tetroxide selective staining of unsaturated lipids, lanthanum nitrate for intercellular junction identification and zinc-iodide-osmium tetroxide for cytoplasmic endomembrane visualization. The results in both species corroborated the lipid nature of the gland secretion and showed in A. mellifera the poverty of the synthetic machinery in the worker gland cells in comparison with the queen, as expected by previous biochemical analyses. The pathway of the exogenous compounds of the secretion is intracellular, since substances can penetrate the cell folds and intercellular junctions, but their access to the, gland lumen is barred by the apical intercellular junctions.

A new species of torrent frog genus Hylodes (Anura : Leptodactylidae) from southeastern Brazil

We describe a new species of Hylodes from Parque Estadual do Ibitipoca, Conceicao do Ibitipoca, Municipality of Lima Duarte, State of Minas Gerais, southeastern Brazil. The new species is a member of the Hylodes lateristrigatus group, and it is characterized by small size, snout rounded in dorsal view and protruding in lateral view, presence of vocal slits and sacs, upper surface of finger discs without well developed scutes, dorsum light brown to gray with dark blotches, and details of the advertisement call. Descriptions of the tadpole, vocalizations, and information on natural history are provided. The tadpole has a ventral depression anterior to the coiled intestine, as in other species of the genus. Hylodes meridionalis (Mertens), previously considered a member of the H. nasus species group, is transferred to the H. lateristrigatus species group.

A new frog of the genus Hylodes (Amphibia : Leptodactylidae) from Minas Gerais, Brazil

A new species of leptodactylid frog is described from Parque das Mangabeiras, in Belo Horizonte, Minas Gerais, south-eastern Brazil. The new species is a member of the Hylodes lateristrigatus group, and is characterized by medium size, snout rounded in dorsal view and protruding in lateral view, presence of vocal slits and sacs, upper surface of finger and toe discs with well-developed scutes, a weakly developed stripe on the upper lip, dorsum, arm, leg, and foot dark brown with small irregular brown and black dots, and absence of red and yellow spots in live specimens. The descriptions of the tadpoles and vocalizations, and information on natural history are provided. Hylodes perplicatus (Miranda-Ribeiro), previously considered a member of the H. nasus species group, is transferred to the H. lateristrigatus species group.

Redescription of Physalaemus barrioi (Anura: Leiuperidae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Tissue alterations in the Guinea pig lateral prostate following antiandrogen flutamide therapy

The flutamide antiandrogenic effects oil the Guinea pig male prostate morphology in puberal, post-puberal and adult ages were evaluated in the present study. Daily-treated group animals received flutamide Subcutaneous injection at a dose of 10 mg/Kg body weight for 10 days. The control group animals received a pharmacological vehicle under the same conditions. The lateral prostate was removed, fixed and processed for light and transmission electron microscopy. The results revealed all increase of the acinus diameter in the treated puberal animals and straitness in the stromal compartment around the acini. The epithelial cells exhibited cubic phenotype. In the post-puberal and adult animals, a decrease of the acinus diameter was observed, as well as an increase of the smooth muscle layer and presence of the folds at epithelium. The ultrastructural evaluation of the secretory cells in the treated group demonstrated endomembrane enlargement, mainly in the rough endoplasmic reticulum and Golgi apparatus. In addition, a decrease of the microvilli and alterations in the distribution patterns and density of the stromal fibrillar components were observed. In Conclusion, the flutamide treatment exerts tissue effects oil the lateral prostate, promoting stroma/epithelium alterations.

Structural basis for metal ion coordination and the catalytic mechanism of sphingomyelinases D

Sphingomyelinases D (SMases D) from Loxosceles spider venom are the principal toxins responsible for the manifestation of dermonecrosis, intravascular hemolysis, and acute renal failure, which can result in death. These enzymes catalyze the hydrolysis of sphingomyelin, resulting in the formation of ceramide 1-phosphate and choline or the hydrolysis of lysophosphatidyl choline, generating the lipid mediator lysophosphatidic acid. This report represents the first crystal structure of a member of the sphingomyelinase D family from Loxosceles laeta (SMase I), which has been determined at 1.75-angstrom resolution using the quick cryo-soaking technique and phases obtained from a single iodine derivative and data collected from a conventional rotating anode x-ray source. SMase I folds as an (alpha/beta)(8) barrel, the interfacial and catalytic sites encompass hydrophobic loops and a negatively charged surface. Substrate binding and/or the transition state are stabilized by a Mg2+ ion, which is coordinated by Glu(32), Asp(34), Asp(91), and solvent molecules. In the proposed acid base catalytic mechanism, His(12) and His(47) play key roles and are supported by a network of hydrogen bonds between Asp(34), Asp(52), Trp(230), Asp(233), and Asn(252).

Interactions of mast cell degranulating peptides with model membranes: A comparative biophysical study

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Actinic cheilitis: Clinical and histological features

Purpose: The purpose of this study was to analyze the clinical and histological features of actinic cheilitis (AC).Patients and Methods: A total of 29 patients with AC were clinically evaluated, and incisional biopsies were performed to confirm the clinical diagnosis. Histological features were analyzed, and dysplasia was classified as mild, moderate, or severe. The chi(2) test was used for the following variables: gender, age, race, and smoking habits. The degree of dysplasia was related to these variables (Fisher's test) to test for independence between them (P <.05).Results: of the patient group, 72.41% were male, 75.86% were overage 40 years, 93.10% were white, and 72.41% were nonsmokers. Clinically, all patients presented with multifocal lesions. The following manifestations were seen: dryness, atrophy, scaly lesions, swelling of the lip, erythema, ulceration, blurred demarcation between the lip vermilion border and the skin, marked folds along the lip vermilion, white spots or plaques, crusts, blotchy areas, and areas of pallor. Keratosis, granulosis, hyperplasia, acanthosis, or atrophy and dysplasia were found in the epithelial tissue; elastosis, inflammatory infiltrate, and vasodilatation were found in the connective tissue. Dysplasia was mild in 10.34% of the patients, moderate in 27.59%, and severe in 62.07%. Absence of sample homogeneity was observed in regard to gender, age, race, and smoking habits. It was not possible to reject the hypothesis of independence between mild, moderate, or severe dysplasia and gender, age, race, and smoking habits.Conclusions: Dryness, atrophy, and scaly lesions were the most common clinical findings observed. Dysplasia, inflammatory infiltrate, and vasodilatation, as well as elastosis, were the most common histological findings observed. Gender, age, race, or smoking habits were not related to the degree of dysplasia in the sample. (c) 2008 American Association of Oral and Maxillofacial Surgeons.

Solid-phase peptide synthesis in highly loaded conditions

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)