The antiepileptic activity of JSTX-3 is mediated by N-methyl-D-aspartate receptors in human hippocampal neurons

We analyzed the effect of the acylpolyaminetoxin JSTX-3 on the epileptogenic discharges induced by perfusion of human hippocampal slices with artificial cerebrospinal fluid lacking Mg2+ or N-methyl-D-aspartate. Hippocampi were surgically removed from patients with refractory medial temporal lobe epilepsy, sliced in the surgical room and taken to the laboratory immersed in normal artificial cerebrospinal fluid. Epileptiform activity was induced by perfusion with Mg2+-free artificial cerebrospinal fluid or by iontophoretically applied N-methyl-D-aspartate and intracellular and field recordings of CAI neurons were performed. The ictal-like discharges induced by Mg2+-free artificial cerebrospinal fluid and N-methyl-D-aspartate were blocked by incubation with JSTX-3. This effect was similar to that obtained with the N-methyl-D-aspartate receptor antagonist DL(-)2-amino-5 phosphonovaleric acid. Our findings suggest that in human hippocampal neurons, the antiepileptic effect of JSTX-3 is mediated by its action on N-methyl-D-aspartate receptor.

Genetic damage in human peripheral lymphocytes exposed to antimicrobial endodontic agents

Objective. Formocresol, paramonochlorophenol, or calcium hydroxide have been widely used in dental practice to eradicate bacteria and consequently to produce root canal disinfection. Taking into consideration strong evidence for a relationship between DNA damage and carcinogenesis, the purpose of the present study was to evaluate the genotoxic effects of antimicrobial endodontic compounds in human peripheral lymphocytes by single-cell gel ( comet) assay. This technique detects DNA strand breaks in individual cells.Study design. A total of 10 mu L of the tested substance solution (formocreso1, paramonochlorofeno1, and calcium hydroxide at 100-mu g/mL concentration) was added to human peripheral lymphocytes from 10 volunteers for 1 hour at 37 degrees C. The negative control group was treated with vehicle control (PBS) for 1 hour at 37 degrees C, as well. For the positive control group, lymphocytes were exposed to hydrogen peroxide at 100 mu M during 5 minutes on ice.Results. No DNA breakage was detected after a treatment of peripheral lymphocytes by formocresol, paramonochlorophenol, or calcium hydroxide at 100 mu g/mL.Conclusions. In summary, our results indicate that exposure to formocresol, paramonochlorophenol, or calcium hydroxide may not be a factor that increases the level of DNA lesions in human peripheral lymphocytes as detected by single-cell gel (comet) assay.

Determination of cinnamic acid in human urine by differential-pulse polarography

The differential pulse polarographic behaviour of cinnamic acid was studied in acetate and phosphate buffer solutions (pH 3.5-7.5). The reduction mechanism is discussed. The drug can be determined at pH 5.0 over the concentration range 5 X 10(-5)-1 X 10(-3) mol l(-1). The effect of tetraalkylammonium salts on the electroanalytical determination of cinnamic acid was investigated, the direct determination of the drug (0.7-5.5 mu g ml(-1)) in urine samples diluted with acetate buffer (pH 5.0) can be effected in the presence of 1 x 10(-3) mol l(-1) cetyldimethylethylammonium bromide solution. The detection limit was found to be 0.1 mu g ml(-1). The relative standard deviation from six determinations at the 5.5 mu g ml(-1) level was 1%.

Vehicle influence on calcium hydroxide pastes diffusion in human and bovine teeth

The purpose of this study was to compare the pH and calcium ion liberation after use of calcium hydroxide pastes with different paste vehicles in human or bovine teeth. Ninety-two single-rooted human and bovine roots were used. The roots were instrumented and an external cavity preparation was performed. The roots were divided in to human and bovine groups. Each group was subdivided into four subgroups (SB) according to the vehicle:SB1, detergent; SB2, saline; SB3, polyethylenoglycol + camphorated paramonochlorophenol (Calen PMCC) and SB4, polyethylenoglycol + furacyn paramonochlorophenol (FPMC). Specimens were immersed into saline solution at 37 degrees C and after 7 and 14 days pH and calcium ion measurements were made. The results were analyzed by ANOVA and Tukey tests (P < 0.05). There was no statistical difference between bovine and human teeth in the pH analysis (P < 0.05), but bovine teeth provided larger calcium ion liberation than human teeth. Calen PMCC was statistically more effective for pH increase and calcium ion liberation in all analyses, followed by FPMC and saline. Detergent showed the lowest pH alterations and calcium ion liberation. The period of 14 days showed more calcium ionic liberation than the 7-day period.

Lithium thiazolidine-4-carboxylate: Synthesis, spectroscopic characterization and preliminary in vitro cytotoxic studies in human HeLa cells

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

Collagen is reduced and disrupted in human aneurysms and dissections of ascending aorta

In ascending aorta aneurysms, there is an enlargement of the whole vessel, whereas aortic dissections (ADs) are characterized by the cleavage of the wall into 2 sheets at the external half. We searched if alterations in collagen could be related to these diseases. Sections of aortas from 14 case patients with acute dissections, 10 case patients with aneurysms, and 9 control subjects were stained with picrosirius. Slides were analyzed under polarized microscopy to evaluate the structure of collagen fibers. The proportion of collagen was calculated in each half of the medial layer by color detection in a computerized image analysis system. Collagen appearance under polarized light was consistent with collagenolysis. The mean collagen proportions at the inner and outer halves, respectively, were 0.50 +/- 0.13 and 0.40 +/- 0.08 in the control group, 0.20 +/- 0.10 and 0.18 +/- 0.12 in the AD group, and 0.33 +/- 0.12 and 0.19 +/- 0.12 in the aneurysm group. The AD (P < .01) and control (P = .04) groups had less collagen at the external half, no difference was found in the aneurysm group (P = .71). In both halves, there was less collagen in the case patients than in the control subjects (all P < .01), but at the internal half, the decrease was significantly greater in the case patients with aneurysms than in those with dissections (P = .03; at the external half, P = .99). Aortic dissections and aneurysms show a decrease in collagen content that could be related to a weakness of the wall underlying the diseases, but the locations of the decrease differ: in dissections, it is situated mostly at the external portion of the media (site of cleavage), whereas in aneurysms, it is more diffuse, consistent with the global enlargement. (c) 2008 Elsevier B.V. All rights reserved.

Downregulation of nuclear factor-kappa B (NF-kappa B) pathway by silibinin in human monocytes challenged with Paracoccidioides brasiliensis

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

Cholangiocarcinoma and Squamous Cell Carcinoma of the Stratified Epithelial Portion of the Stomach in a Horse: A Case Report

Both cholangiocarcinoma and squamous cell carcinoma of the stomach stratified squamous epithelial portion are rarely found in equine medicine despite being more common in human beings, dogs, and cats. The objective of the present article was to report the simultaneous occurrences of these two types of neoplasias in an 11-year-old mare. Numerous firm, whitish nodules were distributed throughout the liver parenchyma and those protruding over its surface were umbilicated in their appearance. It was verified that the nodules adhered to the peritoneum and omentum, diaphragm, spleen, and stomach serosa compressed the adjacent structures. The stomach stratified squamous epithelial portion, particularly originating in the margo plicatus toward the cardia, was covered by numerous smooth, whitish spherules. Microscopic examination allowed the liver, tumor, and the abdominal implants to be identified as a cholangiocarcinoma, and the stomach neoplasia as a carcinoma of its stratified squamous epithelial portion. Considering this as an uncommon finding, although when considered individually, the presence of a cholangiocarcinoma and a squamous cell carcinoma of the stratified squamous epithelial portion of the equine stomach in the same specimen is worthy of reporting. (C) 2011 Elsevier B.V. All rights reserved.

Foraging behavior of Hudsonian Godwit Limosa haemastica (Charadriiformes, Scolopacidae) in human-disturbed and undisturbed occasions in the Atlantic coast of Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Cycloactive, aneugenic and clastogenic effects of Paracoccidioides brasiliensis exoantigen in human lymphocyte cultures

The in vitro effect of Paracoccidioides brasiliensis exoantigen on the human lymphocytes cell cycle and chromosomes was studied. Human peripheral blood lymphocyte cultures from ten healthy, white, non-smoking, non-related adult males (mean age 31·3 ± 8·2 years) were studied. Blood cultures were treated with three exoantigen concentrations (0·25, 2·50 and 10·00 μg ml -1). At least 1000 metaphases were analysed at each concentration, for evaluation of numerical and structural chromosome aberrations (cA) and 30 000 for mitotic index (MI). Among the treated cultures, statistically significant differences in the frequencies of MI and cA were not observed. Nevertheless, when compared with control cultures, they all showed a significantly lower frequency of MI and higher frequency of cA. It is suggested that the detected alterations were caused by the exoantigen, its fractions or its metabolites. © 1996 Informa UK Ltd All rights reserved.

Intrapulpar temperature during continuous CO2 laser irradiation in human molars: An in vitro study

To establish safety parameters, we in vitro studied the increase in intrapulpal temperature caused by the use of a cw CO2 laser. A thermistor was implanted in the inner part of the pulpal chamber of 25 human lower third molars to measure the intrapulpal temperature produced by laser powers between 2-10 W and exposure times of 0.5-25.0 s. The Pearson linear correlation factor applied to the measured values showed there is a direct relationship between the independent variable and the applied power. A variance analysis produced the linear regression equation: T=1.10+(0.127)E where T is the temperature and E the energy. The results showed that, with a power of 4 W and maximum exposure time of 2.5 s (10 J) and a power density of 12738.85 W cm-2, there will be no damaging reactions affecting the pulpal tissues.

Metacyclogenesis modulates the ability of Leishmania promastigotes to induce IL-12 production in human mononuclear cells

Immunity against the intracellular protozoan Leishmania species is highly dependent on Th1 development. We have previously shown that IL-12 is a powerful and probably obligatory factor for Th1 cell generation and proliferation. We also observed that the experimental infection of C3H and BALB/c mice with Leishmania major is associated with IL-12 production in vivo. Now we demonstrate that metacyclic L. major promastigotes are poor inducers of IL-12 in vitro in fresh human PBMC and monocytes. In addition, we show that the ability of this pathogen to induce IL-12 and other cytokines is modulated by the metacyclogenic process, which had previously not been recognized. In contrast to the infective parasites (metacyclic promastigotes), the procyclic promastigotes collected at the logarithmic phase of the culture displayed a striking ability to induce IL-12, IFN-γ, TNF-α, and IL-10. Despite this differential effect of procyclic and metacyclic parasites in terms of IL-12 induction, both stages were inhibitory for IL-12 production induced by Staphylococcus aureus. The ability of procyclic promastigotes and, to a much lesser extent, that of metacyclic promastigotes to induce IL-12 were enhanced by pretreatment of monocytes in a cytokine milieu containing IFN-γ, IL-4, IL-13, or granulocyte-macrophage CSF or. by neutralization of endogenous IL-10. Our results suggest the development of an evasion mechanism as the Leishmania promastigotes mature to infectious forms and the possi-bility of using Ags derived from procyclic promastigotes for immunization procedures. Copyright © 1997 by The American Association of Immunologists.

Collagen fibers in human prostatic lesions: histochemistry and anisotropies

The present study focuses on establishing patterns of collagen fibers distribution in prostatic nodular hyperplasia and adenocarcinomas, in comparison with the normal tissue. Sections of prostatic transurethral resection were subjected to Gömöri's method for collagen fibers and reticulin and analyzed under ordinary and polarized light microscopy. Controls and hyperplastic regions present collagen fibers with variable thickness that run in different directions, establishing a tridimensional network. These fibers exhibit birefringence and dichroism thus demonstrating their fibrillar integrity. On the other hand, increased variability in collagen fiber distribution and anisotropical properties occur in adenocarcinomas evaluated in accordance with the Gleason's score. In some of their areas, a well-defined collagen network delimitates the base of transformed epithelial cells whereas in other areas the collagen fibers are disorganized and do not establish a boundary between the epithelial structures and the stroma. In these areas, collagen is found in the stroma. It was also observed that adenocarcinoma tumor cells rest on a scaffold of thin and dendritic collagen fibers. Collagen fibers of the prostatic stroma of the adenocarcinomas may show a modification in arrangement and fibrillar compactness. In prostatic nodular hyperplasia, there is no change in collagen molecular integrity, since collagen affinity for silver and collagen birefringence are similar to controls. In adenocarcinoma with high dedifferentiation degree, thin and branched strongly argyrophilic and birefringent collagen fibers are detected in regions of cell proliferation. In the adjacent stroma, hyaline plaques are indicative of matrix degradation or remodellation.