Spherites in the midgut epithelial cells of the sugarcane borer parasitized by Cotesia flavipes.

Diatraea saccharalis, the main pest of sugarcane, has been controlled by Cotesia flavipes. Very little is known about the effect of parasitism on the host organs, including the midgut. The Lepidoptera midgut epithelium is composed of columnar, goblet, regenerative, and endocrine cells. Spherites have been described in columnar and regenerative cells of several Lepidoptera species, and presented a lot of functional meaning. We identified spherites in the midgut epithelial cells of non-parasitized D. saccharalis larvae analyzed the effect of parasitism on spherite morphology and distribution along the length of the midgut. Midgut fragments of both non-parasitized and parasitized larvae were processed for transmission electron microscopy. All the midgut epithelial cells showed spherites, but they were not preferentially located in a particular part of the cells. Parasitized larvae had more spherites, mainly in the columnar cells, than non-parasitized larvae. This observation was associated with an ionic imbalance within the insect host. Spherites were more abundant in the anterior midgut region than in other regions, which suggests that this region is involved in ion transport by intracellular and/or paracellular route. The morphological variability of spherites in the cells of parasitized larvae was related to the developmental stages of these structures.

Laryngeal papillomatosis: morphological study by light and electron microscopy of the HPV-6.

UNLABELLED: Laryngeal papillomatosis is the most frequent benign neoplasia in children. It is caused by HPV 6 and 11. The lesions are exophytic and highly recurrent, compromising the airway mucosa, mainly the larynx. Study design--clinical prospective. AIMS: To show morphologic alterations of the epithelium (light and electron microscopy) in the HPV-6 lesions. METHODS: Specimens of laryngeal lesions obtained during surgery of four children (1 male, 3 female) were submitted to HPV typing (PCR), light microscopy and electron microscopy. RESULTS: In all specimens, HPV type 6 was found. Epithelial projections were found by electron microscopy with superficial cells in desquamation. Light microscopy showed exophytic projections of the keratinized stratified squamous epithelium overlying a fibrovascular core. Koilocytes (vacuolated cells), suggesting the viral infection by HPV, were identified. No alterations were seen in the basement membrane and corion. Ultraestrutural analysis showed vacuolated cells with clear cytoplasmic inclusions, intercellular injuries and widening intercellular spaces. CONCLUSIONS: morphologic alterations of the epithelium in the HPV-6 lesions are superficial, and additional studies including the others HPV types are needed to show the more aggressive and extensive aspect of the disease.

Localization and irregular distribution of Na,K-ATPase in myelin sheath from rat sciatic nerve.

Sodium, potassium adenosine triphosphatase (Na,K-ATPase) is a membrane-bound enzyme that maintains the Na(+) and K(+) gradients used in the nervous system for generation and transmission of bioelectricity. Recently, its activity has also been demonstrated during nerve regeneration. The present study was undertaken to investigate the ultrastructural localization and distribution of Na,K-ATPase in peripheral nerve fibers. Small blocks of the sciatic nerves of male Wistar rats weighing 250-300g were excised, divided into two groups, and incubated with and without substrate, the para-nitrophenyl phosphate (pNPP). The material was processed for transmission electron microscopy, and the ultra-thin sections were examined in a Philips CM 100 electron microscope. The deposits of reaction product were localized mainly on the axolemma, on axoplasmic profiles, and irregularly dispersed on the myelin sheath, but not in the unmyelinated axons. In the axonal membrane, the precipitates were regularly distributed on the cytoplasmic side. These results together with published data warrant further studies for the diagnosis and treatment of neuropathies with compromised Na,K-ATPase activity.

[Ultrastructural evaluation of mitomycin C toxic effects on the ciliary epithelium of normal rabbits eyes with and without aqueous humor suppressant treatment]. / Avaliação ultra-estrutural dos efeitos tóxicos da mitomicina C no epitélio ciliar de olhos de coelhos normais com e sem tratamento hipotensor ocular prévio.

PURPOSE: To evaluate the effects of mitomycin C (MMC) on the internal ciliary epithelium (ICE) of the ciliary body of animals treated with two different aqueous humor suppressants. METHODS: The eyes of sixteen Norfolk albino rabbits divided into four experimental groups were studied. The right eyes (RE) of the four groups received 0.1 ml of MMC (0.5 mg/ml) under the scleral flap. The left eyes (LE) was the control group. Group 1 (G1) did not have any other treatment. To Group 2 (G2) and Group 4 (G4) acetazolamide was administered. To Group (G3) and Group 4 (G4) timolol maleate was administered. ICE was examined by transmission electron microscopy (TEM). RESULTS: The following aspects were observed in all groups, except in G1 LE: cell shrinkage and/or enlargement of intercellular spaces, rarefied mitochondria, clear vesicular structures and electron-dense bodies. The internal limitant membrane showed to be thickened, discontinued and separated in all groups, except in G1 LE and G2 LE. Discharge of cytoplasmatic material was observed only in the groups treated with aqueous humor suppressants. CONCLUSIONS: 1) MMC, acetazolamide and timolol maleate caused morphological alterations in the ciliary epithelium even when used alone. 2) The combination of MMC and acetazolamide caused more alterations than did isolated acetazolamide, but not more than MMC alone. 3) For the other combinations the alterations were similar.

[Choroidal vessels alterations in treated and untreated diabetic rats]. / Alterações vasculares na coróide de ratos diabéticos tratados e não tratados.

PURPOSE: To evaluate the diabetic alterations and the impact of short and long-term medical treatment on them. METHODS: Thirty Wistar rats were divided into 3 groups: control (GC), diabetic (DG), and treated diabetic (TG) and the observations were made 1 month (M1) and 12 months (M2) after diabetes induction. Diabetes was induced by intravenous alloxan (42 mg/kg). The treated group received acarbose orally and insulin by subcutaneous injection. Eyes were prepared for transmission electron microscopy, specifically for ultrastructure of the Bruch membrane and choroidal vessels. RESULTS: Ultrastructural examination of the diabetic rat choroid showed deposits in the Bruch membrane and accumulation of vesicles, glycogen and dense bodies in endothelial cell cytoplasm. The most affected group was that of the diabetics on month 12 (GDM2). The treated diabetics showed the least alterations on month 12 (GTM2). CONCLUSION: Diabetic rats develop degenerative alterations in the Bruch membrane and choroidal vessels. These alterations are more evident in animals submitted to chronic disease, but they are also present in acute disease. Degenerative processes were not avoided with short-term treatment. Long-term treatment inhibited the progress of these processes.

Ultrastructure of the ovariole sheath in Diatraea saccharalis (Lepidoptera: Pyralidae).

The ultrastructure of the ovariole sheath along the Diatraea saccharalis ovariole was studied by scanning and transmission electron microscopy. Each ovariole is surrounded by an epithelial sheath, a tunica propria and scattered lumen cells. These three components of the ovariole sheath show different ultrastructural features along the ovariole, in the germarium or in the vitellarium; these differences are more evident in the epithelial sheath cells. The epithelial sheath is composed by two layers of cells, the external one running longitudinally and the internal one running circularly in the ovariole. These cells, in vitellarium, present cytoplasmic bundles of myofilaments that are arranged parallel to the long axis of the cells; these myofilaments are apparently related to the contraction movements of the follicles within the ovariole. The acellular tunica propria, composed of finely filamentous material, is attached to the adjacent follicle cells by adhesive dense plates. Between the epithelial sheath and the tunica propria there is a population of lumen cells, with morphological features of secretory activity.

[Mitomycin C toxicity in rabbit corneal endothelium]. / Toxicidade da mitomicina C ao endotélio da córnea de coelhos.

PURPOSE: To evaluate corneal endothelium alterations after applying mitomycin C to the sclera using transmission and scanning electron microscopy, correlating alterations with time, concentration, and evaluation methods. METHODS: The corneal endothelium of both eyes of 32 albino rabbits was evaluated and distributed into four groups of 8. Mitomycin C was applied under a scleral flap in the right eye for 5 minutes. Mitomycin C concentrations were 0.5 mg/ml for G1 and G2 and 0.2 mg/ml for G3 and G4. Examinations were performed 15 days after application to G1 and G3, and 30 days after application to G2 and G4. Four cornea in each group were prepared for transmission electron microscopy and four for scanning electron microscopy. Left eyes of all animals were used as controls. RESULTS: Transmission electron microscopy showed corneal endothelium alterations in all groups: rarefied cytoplasm, dilation and fragmentation of rough endoplasmic reticulum cisternae, Golgi apparatus with cisternal dilation, reduced vacuoles, and irregularities of internal membrane more noticeable in G1 and G2. Scanning electron microscopy revealed alterations in all groups except G1: changes in the shape and size of cells and longer filopodial projections. CONCLUSIONS: 1 - Corneal endothelium alterations were seen at both 0.5 and 0.2 mg/ml concentrations and at 15 and 30 days after mytomicin C application; 2 - Alterations were more intense with higher mytomicin C concentration by transmission electron but not by scanning electron microscopy; 3 - The alterations correlated with time by scanning electron microscopy but not by transmission electron microscopy.

Is Reinke's edema a precancerous lesion? Histological and electron microscopic aspects.

The objectives of this study were to evaluate morphologic alterations and precancerous lesions in Reinke's edema. Patients included were 54 smokers with bilateral Reinke's edema submitted to surgery in the Otolaryngology Department, Botucatu Medical School, São Paulo State University, Brazil, between 2002 and 2006. All specimens were evaluated by light microscopy and five contralateral lesions were also evaluated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The main histological alterations were edema (100%), inflammation (81.48%), basal membrane (bm) thickening (77.77%), and vessel proliferation (75.92%). Epithelium alterations were classified as grade 0 (11.11%), grade 1 (70.37%), grade 2 (14.81%), and grade 3 (3.70%). In the case included in grade 3 classification, microinvasive carcinoma was detected. SEM showed epithelial surface with some cellular desquamation, few microridges, and a polished and impermeable surface aspect. TEM showed epithelial hyperplasia, basal cells with different sizes, widening of the intercellular spaces, abnormal desmosome architecture, thickening of the bm, some electron-dense vesicles, and points of interruption. The morphological alterations presented in this study are not specific to Reinke's edema but this lesion can be the site of different grades of dysplasia and carcinoma, justifying the importance of periodic laryngeal endoscopic exams and meticulous histological analysis.

Lidocaine effects on corneal endothelial cell ultrastructure.

The purpose of this study was to determine whether intracameral commercial lidocaine 2% induces alterations on the rabbit corneal endothelium. Forty white rabbits received different substances inside the anterior chamber: group (G)1, no substance; G2 and G3 received lidocaine 2% with preservative in aqueous solution; G4 and G5, lidocaine 2% with preservative in gel solution; G6 and G7, the anesthetic preservative (metilparahydroxybenzoate 0.1%); and G8 and G9, lidocaine 2% without preservative in aqueous solution. The animals from G2, 4, 6 and 8 were sacrificed after 1 h, and from G3, 5, 7 and 9 after 24 h after injection of the substance inside the anterior chamber. The corneas were clinically evaluated and assessed by transmission and scanning electron microscopy. G1, 2, 6, 7, 8 and 9 animals had very similar characteristics in clinical, ultrastructural and morphometric evaluations; the G3 and G4 animals showed discrete edema and one animal in G5 had intense corneal edema. We conclude that lidocaine 2% with preservative induces few ultrastructural alterations in the corneal endothelial cells.

The Lanz endotracheal tube decreases tracheal injury in dogs.

PURPOSE: To determine, in dogs anesthetized with nitrous oxide (N2O), (whether the endotracheal tube (ETT) cuffed with a Lanz pressure regulating valve decreases the tracheal consequences of tracheal intubation. METHODS: Sixteen mixed-breed dogs were allocated to two groups according to the ETT used: Control group (n = 8) - Rüsch ETT, and Lanz group (n = 8) - ETT with Lanz pressure regulating valve. The ETT cuffs in both groups were inflated with air to an intracuff pressure of 30 cm H2O. Anesthesia was induced and maintained with pentobarbitone and N2O (1.5 L x min(-1)) and O2 (1 L x min(-1)). ETT cuff pressures were measured before (control) and 60, 120, and 180 min during N2O administration. The dogs were sacrificed, and biopsy specimens from four predetermined areas of the tracheal mucosa in contact with the ETT were collected for light and scanning electron microscopy (SM) examination. RESULTS: Cuff pressures in the Control group were higher than in the Lanz group at all time points studied (P < 0.001), with an increase over time only in the Control group (P < 0.001). Median neutrophilic inflammatory infiltration values of the epithelial surface, and in the subepithelial layer in contact with the cuff, were higher in the Control group as compared to the Lanz group (3.0 vs 1.0 and 3.0 vs 1.5 respectively) (P < 0.05). On SM examination, median histological grades were higher in the Control group compared to Lanz group (2.9 vs 1.9 respectively), (P < 0.05). CONCLUSIONS: The Lanz ETT decreases tracheal mucosal injury in dogs.

Toxicidade da mitomicina C ao endotélio da córnea de coelhos / Mitomycin C toxicity in rabbit corneal endothelium

OBJETIVO: Avaliar alterações do endotélio corneano após aplicação de mitomicina C na esclera por meio de microscopia eletrônica de transmissão e de varredura e correlacionar as alterações com tempo, concentração e entre os dois métodos de avaliação. MÉTODOS: Foi avaliado o endotélio corneano dos olhos de 32 coelhos albinos distribuídos em 4 grupos experimentais com 8 coelhos cada um. A mitomicina C foi aplicada sob retalho escleral no olho direito por 5 minutos. Nos grupos G1 e G2 a concentração da mitomicina C foi de 0,5 mg/ml e nos grupos G3 e G4 a concentração foi de 0,2 mg/ml. O exame foi realizado com 15 dias após nos grupos G1 e G3 e com 30 dias nos grupos G2 e G4. Dos 8 animais 4 foram preparados para microscopia eletrônica de transmissão e 4 para microscopia eletrônica de varredura. Os olhos esquerdos de todos animais serviram como controle. RESULTADOS: À microscopia eletrônica de transmissão foram observadas alterações do endotélio corneano em todos os grupos experimentais: rarefação do citoplasma, dilatação e fragmentação das cisternas do retículo endoplasmático rugoso, aparelhos de Golgi com dilatação das cisternas, redução de vacúolos e irregularidades da membrana celular interna sendo mais intensas em G1 e G2. À microscopia eletrônica de varredura foram observadas alterações em todos grupos experimentais, exceto G1: alteração de forma e tamanho das células e projeções filopoidais mais longas. CONCLUSÕES: 1 - A mitomicina C causou alteração no endotélio da córnea tanto na concentração de 0,5 mg/ml como de 0,2 mg/ml observadas 15 e 30 dias após a aplicação; 2 - As alterações foram mais intensas com a maior concentração de mitomicina C (0,5 mg/ml) na microscopia eletrônica de transmissão e não na microscopia eletrônica de varredura; 3 - As alterações tiveram correlação com o tempo na microscopia eletrônica de varredura e não na microscopia eletrônica de transmissão.

PURPOSE: To evaluate corneal endothelium alterations after applying mitomycin C to the sclera using transmission and scanning electron microscopy, correlating alterations with time, concentration, and evaluation methods. METHODS: The corneal endothelium of both eyes of 32 albino rabbits was evaluated and distributed into four groups of 8. Mitomycin C was applied under a scleral flap in the right eye for 5 minutes. Mitomycin C concentrations were 0.5 mg/ml for G1 and G2 and 0.2 mg/ml for G3 and G4. Examinations were performed 15 days after application to G1 and G3, and 30 days after application to G2 and G4. Four cornea in each group were prepared for transmission electron microscopy and four for scanning electron microscopy. Left eyes of all animals were used as controls. RESULTS: Transmission electron microscopy showed corneal endothelium alterations in all groups: rarefied cytoplasm, dilation and fragmentation of rough endoplasmic reticulum cisternae, Golgi apparatus with cisternal dilation, reduced vacuoles, and irregularities of internal membrane more noticeable in G1 and G2. Scanning electron microscopy revealed alterations in all groups except G1: changes in the shape and size of cells and longer filopodial projections. CONCLUSIONS: 1 - Corneal endothelium alterations were seen at both 0.5 and 0.2 mg/ml concentrations and at 15 and 30 days after mytomicin C application; 2 - Alterations were more intense with higher mytomicin C concentration by transmission electron but not by scanning electron microscopy; 3 - The alterations correlated with time by scanning electron microscopy but not by transmission electron microscopy.

[Effects of tracheal tube cuff limit pressure (25 cmH2O) and "seal" pressure on tracheal mucosa of dogs.]. / Efeitos da pressão limite (25 cmH2O) e mínima de "selo" do balonete de tubos traqueais sobre a mucosa traqueal do cão.

BACKGROUND AND OBJECTIVES: Injuries of tracheal mucosa in contact with tracheal tube cuff is a function of cuff pressure and exposure time. This study aimed at analyzing injuries of tracheal mucosa in contact with tracheal tube cuff inflated to reach "seal" pressure or limit 25 cmH2O pressure, below critical 30 cmH2O, to prevent tracheal damage. METHODS: This study involved 16 dogs submitted to intravenous anesthesia and artificial ventilation. Dogs were randomly distributed into two experimental groups according to tracheal tube cuff pressure (Portex Blue Line, UK): Gseal (n = 8) cuff with minimum "seal" pressure to prevent air leakage during artificial ventilation; G25 (n=8) cuff inflated to 25 cmH2O. Cuff pressure was measured with a digital manometer at the beginning of the experiment (control) and 60, 120 and 180 minutes later. Animals were sacrificed and tracheal mucosa areas adjacent to the tracheal tube cuff were biopsed by scanning electronic microscopy (SEM). RESULTS: Mean cuff pressure was maintained between 24.8 and 25 cmH2O in G25 and between 11.9 and 12.5 cmH2O in Gseal. SEM changes were mild and not significantly different between groups (p > 0.30), with more severe injuries to tracheal areas in contact with the cuff as compared to areas adjacent or not to tracheal tube (p < 0.05). CONCLUSIONS: In dogs under our experimental conditions, tracheal tube cuff inflation to 25 cmH2O limit or to "seal" pressure to prevent air leakage has determined minor injuries to the tracheal mucosa in contact with tracheal tube cuff, without significant differences between groups.

Papilomatose laríngea: análise morfológica pela microscopia de luz e eletrônica do HPV-6 / Laryngeal papillomatosis: morphological study by light and electron microscopy of the HPV-6

Papilomatose laríngea é neoplasia benigna mais freqüente nas crianças, causada pelo HPV, principalmente subtipos 6 e 11 e caracteriza-se pela presença de lesões proliferativas exofíticas e recidivantes sobre a mucosa das vias aérea, em especial na laringe. Forma de Estudo: Clínico prospectivo. OBJETIVOS: Demonstrar alterações epiteliais morfológicas (pela microscopia de luz e eletrônica) em lesões papilíferas casadas pelo HPV-6. MATERIAL E MÉTODOS: Fragmentos de lesões de papilomatose laríngea, colhidos durante procedimento cirúrgico de quatro crianças (1 masculino, 3 femininas), foram submetidos à tipagem do HPV (por método de PCR), análise pela microscopia de luz e microscopia eletrônica (varredura e transmissão). RESULTADOS: Na tipagem, todos os papilomas eram do subtipo 6. A microscopia de varredura identificou projeções epiteliais de vários tamanhos, com células superficiais em descamação. A microscopia de luz demonstrou lesões exofíticas, revestidas por epitélio hiperplásico com coilócitos e binucleações, característicos do HPV. A membrana basal e o córion adjacente estavam íntegros. À microscopia eletrônica de transmissão identificou-se vacuolização perinuclear e alargamento das junções intercelulares. CONCLUSÕES: As alterações morfológicas apresentadas pelo HPV-6 demonstram o caráter não-invasivo da lesão, sendo necessário estudos morfológicos adicionais relacionando os outros tipos de HPV, considerados mais agressivos, com os achados ultra-estruturais.

Laryngeal papillomatosis is the most frequent benign neoplasia in children. It is caused by HPV 6 and 11. The lesions are exophytic and highly recurrent, compromising the airway mucosa, mainly the larynx. Study design - clinical prospective. AIMS: to show morphologic alterations of the epithelium (light and electron microscopy) in the HPV-6 lesions. METHODS: specimens of laryngeal lesions obtained during surgery of four children (1 male, 3 female) were submitted to HPV typing (PCR), light microscopy and electron microscopy. RESULTS: in all specimens, HPV type 6 was found. Epithelial projections were found by electron microscopy with superficial cells in desquamation. Light microscopy showed exophytic projections of the keratinized stratified squamous epithelium overlying a fibrovascular core. Koilocytes (vacuolated cells), suggesting the viral infection by HPV, were identified. No alterations were seen in the basement membrane and corion. Ultraestrutural analysis showed vacuolated cells with clear cytoplasmic inclusions, intercellular injuries and widening intercellular spaces. CONCLUSIONS: morphologic alterations of the epithelium in the HPV-6 lesions are superficial, and additional studies including the others HPV types are needed to show the more aggressive and extensive aspect of the disease.

Avaliação ultra-estrutural dos efeitos tóxicos da mitomicina C no epitélio ciliar de olhos de coelhos normais com e sem tratamento hipotensor ocular prévio / Ultrastructural evaluation of mitomycin C toxic effects on the ciliary epithelium of normal rabbits eyes with and without aqueous humor suppressant treatment

OBJETIVO: Avaliar o epitélio ciliar interno (ECI) do corpo ciliar após aplicação de mitomicina C (MMC) sob retalho escleral, em animais tratados com dois tipos de inibidores da produção do humor aquoso. MÉTODOS: Foram estudados ambos os olhos de 16 coelhos divididos em 4 grupos experimentais. Foi realizado retalho escleral em todos os olhos dos animais, mas apenas os olhos direitos (OD) receberam MMC. No grupo 1 (G1) não houve tratamento prévio. Nos grupos G2 e G4 foi administrada acetazolamida e nos grupos G3 e G4 maleato de timolol. O ECI foi examinado à microscopia eletrônica de transmissão (MET). Os olhos esquerdos formaram os grupos controle. RESULTADOS: Em todos os grupos exceto no G1 OE, foram observadas: retração das células e/ou alargamento entre invaginações, mitocôndrias com rarefação, vesículas claras e corpos densos. A membrana limitante interna estava espessada, descontínua ou descolada em todos grupos exceto G1 OE e G2 OE. Foi observada liberação de material citoplasmático apenas nos grupos tratados com inibidores da produção de humor aquoso. CONCLUSÕES: 1- MMC, acetazolamida e maleato de timolol causaram alterações morfológicas no epitélio ciliar mesmo usados isoladamente. 2- A associação MMC e acetazolamida causou mais alterações do que a acetazolamida isoladamente, mas não mais do que a MMC isoladamente. 3- Nas demais associações as alterações foram semelhantes.

PURPOSE: To evaluate the effects of mitomycin C (MMC) on the internal ciliary epithelium (ICE) of the ciliary body of animals treated with two differents aqueous humor supressants. METHODS: The eyes of sixteen Norfolk albino rabbits divided into four experimental groups were studied. The right eyes (RE) of the four groups received 0.1 ml of MMC (0.5 mg/ml) under the scleral flap. The left eyes (LE) was the control group. Group 1 (G1) did not have any other treatment. To Group 2 (G2) and Group 4 (G4) acetazolamide was administered. To Group (G3) and Group 4 (G4) timolol maleate was administered. ICE was examined by transmission electron microscopy (TEM). RESULTS: The following aspects were observed in all groups, except in G1 LE: cell shrinkage and/or enlargement of intercellular spaces, rarefied mitochondria, clear vesicular structures and electron-dense bodies. The internal limitant membrane showed to be thickened, discontinued and separeted in all groups, except in G1 LE and G2 LE. Discharge of cytoplasmatic material was observed only in the groups treated with aqueous humor supressants. CONCLUSIONS: 1) MMC, acetazolamide and timolol maleate caused morphological alterations in the ciliary epithelium even when used alone. 2) The combination of MMC and acetazolamide caused more alterations than did isolated acetazolamide, but not more than MMC alone. 3) For the other combinations the alterations were similar.

Alterações vasculares na coróide de ratos diabéticos tratados e não tratados / Choroidal vessels alterations in treated and untreated diabetic rats

OBJETIVO: Conhecer os efeitos do diabetes e o impacto de seu tratamento medicamentoso em curto e longo prazo sobre os vasos da coróide e membrana de Bruch. MÉTODOS: Foram estudados 30 ratos Wistar, divididos em 3 grupos experimentais: grupo controle (GC), grupo diabético (GD) e grupo diabético tratado (GT), estudados 1 mês (momento M1) e 12 meses (momento M2) após o início do experimento. O diabetes foi induzido por aloxana endovenosa, na dose de 42 mg/kg. O GT foi tratado com hipoglicemiante oral (acarbose) e insulina subcutânea. Após o sacrifício, os olhos foram preparados para exame ao microscópio eletrônico de transmissão, interessando a ultra-estrutura da membrana de Bruch e os vasos da coróide. RESULTADOS: O exame ultra-estrutural da coróide dos ratos diabéticos mostrou depósitos na membrana de Bruch, acúmulo de vesículas, glicogênio e corpos densos no citoplasma das células endoteliais. O grupo mais afetado foi de ratos diabéticos de 12 meses (GDM2). Os animais com menor intensidade de alterações foram os ratos tratados por 12 meses (GTM2). CONCLUSÃO: Os ratos diabéticos desenvolveram alterações degenerativas na membrana de Bruch e vasos da coróide. Estas alterações foram mais evidentes nos animais submetidos à doença crônica, mas também ocorreram agudamente. O tratamento a curto prazo não foi capaz de evitar os processos degenerativos. A longo prazo, o tratamento inibiu a progressão destes processos.

PURPOSE: To evaluate the diabetic alterations and the impact of short and long-term medical treatment on them. METHODS: Thirty Wistar rats were divided into 3 groups: control (GC), diabetic (DG), and treated diabetic (TG) and the observations were made 1 month (M1) and 12 months (M2) after diabetes induction. Diabetes was induced by intravenous alloxan (42 mg/kg). The treated group received acarbose orally and insulin by subcutaneous injection. Eyes were prepared for transmission electron microscopy, specifically for ultrastructure of the Bruch membrane and choroidal vessels. RESULTS: Ultrastructural examination of the diabetic rat coroid showed deposits in the Bruch membrane and accumulation of vesicles, glycogen and dense bodies in endothelial cell cytoplasm. The most affected group was that of the diabetics on month 12 (GDM2). The treated diabetics showed the least alterations on month 12 (GTM2). CONCLUSION: Diabetic rats develop degenerative alterations in the Bruch membrane and choroidal vessels. These alterations are more evident in animals submitted to chronic disease, but they are also present in acute disease. Degenerative processes were not avoided with short-term treatment. Long-term treatment inhibited the progress of these processes.

Utilização do AutoCAD 2004 para quantificação de pesquisas usando fotomicrografias eletrônicas / AutoCAD 2004 to quantify electron-photomicrography

OBJETIVO: Avaliar o uso do programa AutoCAD 2004 para estudos quantitativos em microscopia eletrônica. MÉTODOS: A demonstração da utilização do AutoCAD 2004 foi feita em um modelo experimental de diabetes induzido em ratos, divididos em Grupo Controle (GC-10 animais) e Grupo Diabético (GD - 10 animais), avaliados 1 mês depois da indução do diabetes. Os olhos foram removidos após o sacrifício dos animais e preparados para exame em microscópio eletrônico, tendo sido feitas fotografias dos vasos retinianos. Foi utilizado o programa AutoCAD2004 para avaliar a espessura da membrana basal dos vasos. Os resultados foram avaliados estatisticamente. RESULTADOS: Usando o método proposto foi possível realizar medidas quantitativas na membrana basal de vasos retinianos de ratos diabéticos. CONCLUSÃO: O AutoCAD 2004 se mostrou efetivo, seguro e de fácil utilização para a quantificação de fenômenos biológicos, sendo possível sugerir este meio para a realização de avaliações quantitativas em experimentos biológicos.

OBJECTIVE: To determine if the AutoCAD 2004 program is available to be used in quantitative research on electron microscopy. METHODS: A demonstrative of the AutoCAD2004 was done in an experimental model of diabetes induced in rats. The animals were divided by lot in control group animals (GC-10 animals) and diabetic group (GD - 10 animals), evaluated 1 month after the diabetes induction. The eyes were removed after sacrifice and prepared to electron microscopy. The retina was photographed and the AutoCAD2004 program was used to measure the basal membrane of retina vessels. The results were submitted to statistical analysis. RESULTS: The AutoCAD2004 was effective to obtain quantitative measures from the basal membrane of retina vessels and there were no difference between the studied groups. CONCLUSION: The AutoCAD2004 was effective, safe and easy to apply to quantify biological parameters, which allowed suggest it to quantitative research.

Ultrastructure of Giardia duodenalis trophozoites group from hamster: some relevant aspects

Throphozoites of Giardia duodenalis group obtained from fragments or scratched of hamster's mucosa were examined by transission electron microscopy. The fine structure of the trophozoites are presented and comapred with those described for other animals. Some of the trophozoites present the cytoplasm full of glycogen, rough endoplasmic reticulum-like structures and homogeneous inclusions not enclosed by membranes, recognized as lipid drops, which had not been observed in Giardia from other animals. The adhesive disk is composed of a layer of microtubules, from which fibrous ribbons extend into the cytoplasm; these ribbons are linked by layer of crossbridge filaments that shows an intermediary dense band, described for the first time in this paper. The authors regard this band as the result of the cross-bridge filaments slinding in the medium region between adjacent fibrous ribbons, and suggest a contractile activity for them. The role of the adhesive disk on the trophozoite mechanism of attachment to host mucosa is also discussed

Giardia muris and Giardia duodenalis groups: ultrastructural differences between the trophozoites

Neste trabalho foi analisada, através de Microscopia Eletrônica de Transmissäo, a morfologia de trofozoitos de Giardia muris obtidos de hamsters, ratos peridomiciliares e camundongos, bem como de trofozoitos de Giardia duodenais obtidos de hamsters e ratos peridomiciliares . Basicamente a ultraestrutura dos trofozoitos estudados foi semelhante. Foram observadas, no entanto, diferenças na morfologia de franja ventro-lateral dos trofozoitos de Giardia muris quando comparados com os de Giardia duodenalis, diferenças estas relacionadas ao tamanho, arranjo das lâminas marginais e presença de lamela osmiofílica

Giardia agilis: ultrastructure of the trophozoites in the frog intestine

Intestine samples of Bufo sp. tadpoles with parasitism confirmed for Giardia agilis were studied by transmission electron microscopy. The G. agilis trophozoites were long and thin. The plasma membrane was sometimes undulated and the cytoplasm, adjacent to the dorsal and ventral regions, showed numerous vacuoles. The two nuclei presented prominent nucleoli. The cytoplasm was electron-dense with free ribosomes, glycogen and rough endoplasmic reticulum-like structures. Polyhedral inclusions were observed in the cytoplasm and outside the protozoan; some of these inclusions exhibited membrane disruption. The flagella ultrastructure is typical, with the caudal pair accompanied by the funis. Next to the anterior pair, osmiophilic material was noticed. The ventro-lateral flange was short and thick, supported by the marginal plates that penetrated into its distal extermity; only its distal portion had adjacent osmiophilic filament. The G. agilis trophozoites showed the general subcellular feature of the genus. However, the ventro-lateral flange ultrastructure was an intermediate type between G. muris and G. duodenalis.

Efeito do colírio de 5-fluorouracil sobre o epitélio corneano íntegro de coelhos / Effects of 5-fluorouracil eye drops on intact rabbit corneal epithelium

OBJETIVO: Observar os efeitos da aplicaçäo tópica de 5-fluorouracil (5-FU) sobre o epitélio corneano íntegro. MÉTODOS: Foram utilizados 10 coelhos albinos (14 olhos), divididos em: grupo controle (GC), 4 olhos nos quais näo se administraram drogas, grupo 1 (G1), 5 olhos que receberam 5-fluorouracil na concentraçäo 1,25 por cento e grupo 2 (G2), 5 olhos que receberam 5-fluorouracil na concentraçäo de 2,5 por cento. A droga foi instilada 4 vezes por dia, durante 7 dias, quando os animais foram sacrificados, os olhos removidos, separando-se a córnea que foi preparada de modo convencional para estudo em microscópico eletrônico de varredura. RESULTADOS: GC: observaram-se células de formato hexagonal, claras, escuras e intermediárias, compondo o epitélio corneano de coelhos. Presença de numerosas microplicas, principalmente nas células claras. Cada célula possui cerca de 1 a 3 criptas. Nos animais do G1, observou-se maior número de células escuras, regiöes com diminuiçäo no número de criptas; alteraçöes da superfície celular, protusäo na regiäo do núcleo e descamaçäo de células epiteliais. Os do G2 tiveram aumento de microprojeçöes na superfície celular, modificaçöes nas junçöes intercelulares até separaçäo de células adjacentes; diminuiçäo do número e variabilidade no tamanho das criptas. As alteraçöes mais freqüentes ocorreram nas células da periferia da córnea. CONCLUSÄO: O 5-fluorouracil teve efeitos deletérios no epitélio íntegro corneano de coelhos. As alteraçöes observadas foram mais importantes nos animais que receberam a droga mais concentrada (G2) e mais freqüentes na periferia da córnea