(65)Zn(2+) transport by isolated gill epithelial cells of the American lobster, Homarus americanus

Gills are the first site of impact by metal ions in contaminated waters. Work on whole gill cells and metal uptake has not been reported before in crustaceans. In this study, gill filaments of the American lobster, Homarus americanus, were dissociated in physiological saline and separated into several cell types on a 30, 40, 50, and 80% sucrose gradient. Cells from each sucrose solution were separately resuspended in physiological saline and incubated in (65)Zn(2+) in order to assess the nature of metal uptake by each cell type. Characteristics of zinc accumulation by each kind of cell were investigated in the presence and absence of 10 mM calcium, variable NaCl concentrations and pH values, and 100 mu M verapamil, nifedipine, and the calcium ionophore A23187. (65)Zn(2+) influxes were hyperbolic functions of zinc concentration (1-1,000 mu M) and followed Michaelis-Menten kinetics. Calcium reduced both apparent zinc binding affinity (K (m)) and maximal transport velocity (J (max)) for 30% sucrose cells, but doubled the apparent maximal transport velocity for 80% sucrose cells. Results suggest that calcium, sodium, and protons enter gill epithelial cells by an endogenous broad-specificity cation channel and trans-stimulate metal uptake by a plasma membrane carrier system. Differences in zinc transport observed between gill epithelial cell types appear related to apparent affinity differences of the transporters in each kind of cell. Low affinity cells from 30% sucrose were inhibited by calcium, while high affinity cells from 80% sucrose were stimulated. (65)Zn(2+) transport was also studied by isolated, intact, gill filament tips. These intact gill fragments generally displayed the same transport properties as did cells from 80% sucrose and provided support for metal uptake processes being an apical phenomenon. A working model for zinc transport by lobster gill cells is presented.

P-Glycoprotein Expression, Tumor Weight, Age, and Relapse in Patients with Stage I and II Favorable-Histology Wilms` Tumor

Fifteen percent of patients with Wilms`` tumor (WT) experience relapse. It has been suggested that weight and age may affect the chances of relapse. Few studies have investigated the role, if any, between P-glycoprotein (P-gp) and relapse. The authors assessed the prognostic value of tumor weight and age at diagnosis and asked whether some other potential biological markers, specifically P-gp protein expression, had a prognostic value in favorable-histology WT. No association between age and relapse could be found. Patients with tumor weight >= a parts per thousand yen550 g were 6 times more likely to relapse, whereas P-gp expression was positive in 18/40 (45%%) of the patients, of which 10/12 (83.3%%) relapsed and 8/28 (28.6%%) did not. Further studies are necessary to elucidate whether or not P-gp is related to relapse in patients with histologically favorable Wilms`` tumor. If confirmed, the protein may be used in the future as a target for new drugs and treatments for this group of patients.

Kinetic Analysis of Gill (Na+,K+)-ATPase Activity in Selected Ontogenetic Stages of the Amazon River Shrimp, (Decapoda, Palaemonidae): Interactions at ATP- and Cation-Binding Sites

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

Toxicidade aguda e efeitos histopatológicos do herbicida diquat na brânquia e no fígado da tilápia nilótica (Oreochromis niloticus)

The lethal concentration of 50% (LC (I) and the histopathologic effects of diquat herbicide on Nile tilapia (Oreochromis niloticus) fish were evaluated in three experiments. The fishes were exposed to concentrations of 0, 25, 30, 35, 40, 45, 50, 55 and 60 rug diquat L-1, and gill and liver histology were evaluated in the surviving fishes. The estimated LC (I) (50-96h) of diquat was 37.28 mg L-1, with lower limits of 33.12 mg L-1 and upper limits of 41.44 mg L-1. In the treatment with 30, 35 and 40 mg L-1, signs of apical fusion of the secondary lamellae were observed; with 45 and 50 mg L-1, congestion of the primary lamellae was observed; in the treatment with 55 mg L-1, congestion of blood vessels on secondary lamellae took place. The livers of fishes in treatments with 0, 25, 30 and 35 mg L-1showed cordonal organization of hepatocytes. In the treatments with 40 and 45 mg L-1, hypertrophy of hepatocytes took place; with 50 and 55 mg L-1, cell fusion and the presence of vacuoles inside hepatocytes were observed. Diquat presented low risk of toxicity for nile tilapia, as the more severe histopathologic alterations occurred only in higher concentrations.

Haematological and gill responses in parasitized tilapia from valley of Tijucas River, SC, Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

OVARIAN HISTOLOGY and FOLLICULAR SCORE IN FEMALE RATS TREATED WITH NANDROLONE DECANOATE and SUBMITTED TO PHYSICAL EFFORT

The study was conducted to analyze the histology of the ovaries of adults rats treated with steroids, and submitted or not to physical effort. The control group consisted of females submitted to physical effort and sedentary females, both of which received a physiological solution of 0.9% saline. Treated females, sedentary or not, received 6 mg/kg of body weight of nandrolone decanoate. The steroid and physiological solution were administered intraperitoneally, with a single injection per week for 4 consecutive weeks. The applied physical effort was swimming (20 minutes daily, 5 days/week, for the 4 weeks of treatment). Serial sections (5 mu m) of ovaries were prepared for histological evaluation and follicular score. The weight of ovaries and hypophysis, the number of antral and atretic follicles, and the area of corpus luteum were all affected by the steroids. In the ovaries of the control groups, well-developed corpus luteum was observed. In the treated groups, the cortical stroma was occupied by ovarian interstitial tissue. The females treated with steroids presented estral acyclicity. The use of nandrolone decanoate, whether associated with physical effort or not, affected the morphological pattern of the ovaries.

Glibenclamide effects on renal function and histology after acute hemorrhage in rats under sevoflurane anesthesia

Introduction. Hypovolemia from hemorrhage evokes protective compensatory reactions, such as the renin-angiotensin system, which interferes in the clearance function and can lead to ischemia. This study was designed to evaluate the effects of glibenclamide, a K-ATP(+) channel blocker, on renal function and histology in rats in a state of hemorrhagic shock under sevoflurane anesthesia. Material and Methods. Twenty Wistar rats were randomized into two groups of 10 animals each (G1 and G2), only one of which (G2) received intravenous glibenclamide (1 mu g.g(-1)), 60 min before bleeding was begun. Both groups were anesthetized with sevoflurane and kept on spontaneous respiration with oxygen-air, while being bled of 30% of volemia in three stages with 10 min intervals. There was an evaluation of renal function-sodium para-aminohippurate and iothalamate clearances, filtration fraction, renal blood flow, renal vascular resistance-and renal histology. Renal function attributes were evaluated at three moments: M1 and M2, coinciding with the first and third stages of bleeding; and M3, 30 min after M2, when the animals were subjected to bilateral nephrectomy before being sacrificed. Results. Significant differences were found in para-aminohippurate clearance, G1 < G2, and higher renal vascular resistance values were observed in G1. Histological examination showed the greater vulnerability of kidneys exposed to sevoflurane alone (G1) with higher scores of vascular and tubular dilatation. There were vascular congestion and tubular vacuolization only in G1. Necrosis and signs of tubular regeneration did not differ in both groups. Conclusion. Treatment with glibenclamide attenuated acutely the renal histological changes after hemorrhage in rats under sevoflurane anesthesia.

Renal histology and immunohistochemistry after acute hemorrhage in rats under sevoflurane and ketoprofen effect

OBJETIVO: Investigar a influência do inibidor não-seletivo da ciclooxigenase, cetoprofeno (ceto) intravenoso, em alterações histológicas e dos níveis das citocinas renais - fator α de necrose tumoral (TNF- α) e interleucina 1 (IL-1) - após hemorragia de 30% da volemia (10%, três vezes, em intervalos de 10 min). MÉTODOS: Sob anestesia com sevoflurano (sevo), os grupos sevo e sevo+ceto (10 ratos cada) foram preparados cirurgicamente para leitura de pressão arterial média (PAM) e administração de solução de Ringer (5 mL/kg/h) e de cetoprofeno (1,5 mg/kg), no início da anestesia, no grupo sevo+ceto. Mediu-se temperatura retal continuamente. Os valores de temperatura e PAM foram observados antes da primeira hemorragia (T1), após a terceira hemorragia (T2) e 30 min após T2 (T3). Realizada nefrectomia bilateral nos dois grupos para análise histológica e imuno-histoquímica. RESULTADOS: Nos dois grupos, temperatura e PAM diminuíram com relação aos valores basais. Hipotermia foi mais acentuada no grupo sevo (p=0,0002). Necrose tubular foi mais frequente no grupo sevo (p=0,02). As citocinas estiveram igualmente presentes nos rins dos dois grupos. CONCLUSÃO: Cetoprofeno foi mais protetor no rim de rato durante anestesia com sevoflurano e hipovolemia, porém parece que TNF- α e IL-1 não estão envolvidas nessa proteção.

End-to-end arterial anastomosis with fibrin glue in larger arteries: histology, hydroxyproline concentration and tensile strength study in carotids of rabbits

A anastomose arterial término-terminal é demorada, requer tempo prolongado de oclusão vascular e esta associada a necrose focal, infiltração leucocitária e, conseqüentemente, à fibrose e calcificação da parede arterial. A cola de fibrina é uma alternativa para a anastomose microvascular e pode evitar estas alterações com menor aderência aos tecidos vizinhos e melhor coaptação das bordas arteriais. OBJETIVO: Comparar o processo cicatricial de anastomoses convencionais com anastomoses feitas com cola de fibrina em artérias maiores. MÉTODOS: em 22 coelhos, ambas carótidas foram seccionadas transversalmente e reconstruídas por meio de anastomose término-terminal com 4 pontos simples de reparo e cola de fibrina de um lado (G1), e com 8 pontos separados do outro lado (G2). Após 3 e 15 dias, os animais foram destinados aleatoriamente para estudo de força tênsil concentração de hidroxiprolina (8 animais) e avaliação histológica das anastomoses (3 animais). As lâminas histológicas foram coradas pelo HE Masson e Picrossirius polarização (PSP). RESULTADOS: Após 3 e 15 dias a força tênsil aumenta em ambos os grupos, de 280,0± 32,6g para 432,2± 131,2g no Grupo 1 e de 221,4± 72,4g para 452,2± 132,0g no Grupo 2; sem diferença estatística entre os grupos em cada período. A concentração de hidroxiprolina expressa como razão hidroxiprolina/proteína, variou de 0,0816± 0,0651 para 0,0622± 0,0184 no Grupo 1 e de 0,0734± 0,0577 para 0,0460± 0,0271 no Grupo 2; sem diferença estatística entre os períodos e grupos. Os estudos histológicos mostraram discreto aumento das reações de inflamação e reparação no Grupo 2. A técnica PSP mostrou predomínio do colágeno tipo I em relação do colágeno tipo II nas anastomoses de ambos os grupos, sem diferença expressiva entre esses grupos. CONCLUSÃO: A anastomose com a cola de fibrina foi menos lesiva para a parede arterial do que a anastomose convencional. Mesmo usando menos pontos, as características de força tênsil e de cicatrização da anastomose com cola de fibrina foram similares em ambos os grupos. Os tempos de realização das anastomoses foram significativamente maiores do que na anastomose convencional.

Participatory design in the project of virtual learning environment of histology

This present article describes a research on the development, under the approach of participatory design, a virtual teaching-learning of Histology in which students and teachers participated actively in all stages of development of the educational environment. We postulates that the development of virtual learning environment of Histology, through the Participatory Design approach, contributes to greater acceptance and use by students and that the adoption of virtual environment for teaching and learning by teachers is a determining factor of use by students

Pharmacological dose of alpha-tocopherol induces cardiotoxicity in Wistar rats determined by echocardiography and histology

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

Relationship of abomasal histology and parasite-specific immunoglobulin A with the resistance to Haemonchus contortus infection in three breeds of sheep

This study was carried out to evaluate the relationship of abomasal inflammatory cells and parasite-specific immunoglobulin A (IgA) in mucus, with the resistance to Haemonchus contortus infection in three breeds of sheep naturally infected with gastrointestinal nematodes. The breeds were the native Santa Ines sheep, and the European Suffolk and Ile de France breeds. Mast cells, eosinophils and globule leucocytes were enumerated in abomasal mucosa. Eosinophils within the sub-mucosa also were counted separately. Histamine concentration was estimated in abomasal tissue samples. Enzyme-linked immunosorbent assay was carried out in mucus samples to determine the level of IgA anti-H. contortus third and fifth instar. There were no significant differences among group means of these variables (P > 0.05). The correlation coefficients between fecal egg counts (FEC) x mast cells (r = -0.490; P < 0.05) and FEC x eosinophils in sub-mucosa (r = -0.714; P < 0.01) was significant in the Santa Ines sheep. In the Ile de France group, the correlation coefficients between globule leucocytes x FEC (r = -0.879; P < 0.001) and histamine x worm burden (r = -0.833; P < 0.01) were also significant. In the Santa Ines and Ile de France sheep, correlation coefficients between IgA anti-L3 x worm burden and IgA anti-L3 x FEC were negative. In general, inflammatory cells and IgA-parasite-specific in abomasum were inversely associated with H. contortus worm burden and FEC indicating that they may impair parasite development or fecundity in the three breeds of sheep. However, similar mean values of inflammatory cells and IgA were found in the resistant (Santa Ines) and in the susceptible (Suffolk and Ile de France) breeds of sheep. The enumeration of cells by histological assessment does not provide information on their functional activity, which may be different among breeds. Thus, the effect of breed on the functional activity of these and other inflammatory cells is an important area for further study. (c) 2004 Elsevier B.V. All rights reserved.

Persistent Impairment of Testicular Histology and Sperm Motility in Adult Rats Treated with Cisplatin at Peri-Puberty

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)