Tooth morphology, implantation and replacement system of Hoplias malabaricus (Teleostei, Characiformes, Erythrinidae) / Morfologia, implantação e sistema de substituição dentária do Hoplias malabaricus (Teleostei, Characiformes, Erythrinidae)

The oropharyngeal cavity of Hoplias malabaricus, an ichthyophagous freshwater fish, is anatomically adapted to predation. Macroscopic and microscopic analyses were conducted in order to study the morphology and system of implantation and replacement of teeth. The results showed that this teleost has conical and caniniform teeth, with an orthodentin crown covered by an enameloid cap and a vascularised orthodentin in the root. With regard to the implantation system, there is a junction between the tooth and the bone tissue, as a typical physiological dental ankylosis. The teeth are replaced by a resorption process of multinucleated giant cells that actively eliminate the dentin and bone tissue.

A cavidade orofaríngea do Hoplias malabaricus, um peixe de água doce ictiófago, é anatomicamente adaptado à predação. Análises macroscópica e microscópica foram realizadas com o objetivo de estudar a morfologia e o sistema de implantação e substituição dentária. Os resultados mostraram que este teleósteo apresenta dentes cônicos e caniniformes, com coroa de ortodentina coberta por capuz enamelóide e ortodentina vascularizada na raiz. Em relação ao Sistema de implantação, existe uma junção entre o dente e o tecido ósseo, semelhante a uma anquilose dentária fisiológica típica. Os dentes são substituídos por um processo de reabsorção por células gigantes multinucleadas que ativamente eliminam a dentina e o tecido ósseo.

Tooth morphology, implantation and replacement system of Hoplias malabaricus (Teleostei, Characiformes, Erythrinidae).

The oropharyngeal cavity of Hoplias malabaricus, an ichthyophagous freshwater fish, is anatomically adapted to predation. Macroscopic and microscopic analyses were conducted in order to study the morphology and system of implantation and replacement of teeth. The results showed that this teleost has conical and caniniform teeth, with an orthodentin crown covered by an enameloid cap and a vascularised orthodentin in the root. With regard to the implantation system, there is a junction between the tooth and the bone tissue, as a typical physiological dental ankylosis. The teeth are replaced by a resorption process of multinucleated giant cells that actively eliminate the dentin and bone tissue.

Posttherapeutic cure criteria in Chagas' disease: conventional serology followed by supplementary serological, parasitological, and molecular tests.

We performed a critical study of conventional serology, followed by supplementary serological, parasitological, and molecular tests, to assess the response to etiologic treatment of Chagas' disease. A group of 94 Chagas' disease patients treated with benznidazole at least 10 years earlier were evaluated from the laboratory and clinical points of view. When conventional serology (enzyme-linked immunosorbent assay [ELISA], indirect immunofluorescence [IIF], and indirect hemagglutination [IHA]) and classic criteria (consistent results with any two of the three tests) or more rigorous criteria (consistent results from the three tests) were used, 10.6% and 8.5% of patients were considered treated and cured (TC) by classic and rigorous criteria, respectively. Patients were then evaluated using supplementary (recombinant ELISA and Trypanosoma cruzi excreted-secreted antigen blotting [TESA-blot]), parasitological (hemoculture), and molecular (PCR) tests. The results of recombinant ELISA were similar to those with the rigorous criterion (three consistent test results). The TESA-blot group showed a higher percentage (21.3%) of negative results than the groups defined by either cure criterion. Hemoculture and PCR gave negative results for all treated and cured (TC) patients, regardless of the criterion used. Recombinant ELISA and TESA-blot tests showed negative results for 70% and 87.5% of the patients categorized as TC by the classic and three-test criteria, respectively. For patients with discordant conventional serology, the supplementary serological and molecular tests were the decisive factor in determining therapeutic failure. Clinical evaluation showed that 62.5% of TC patients presented with the indeterminate form of the disease. Additionally, treated patients with negative TESA-blot results should be reevaluated later with all methodologies used here to verify whether TESA-blot is a reliable way to determine early parasitological cure of Chagas' disease.

Periodontitis and arthritis interaction in mice involves a shared hyper-inflammatory genotype and functional immunological interferences.

Periodontitis (PD) and rheumatoid arthritis (RA) have been found to be clinically associated and to share the chronic nature of the inflammatory reaction associated with bone resorption activity. However, the mechanisms underlying such association are unknown. Therefore, we examined the basis of Actinobacillus actinomycetemcomitans- and Porphyromonas gingivalis-induced PD and pristane-induced arthritis (PIA) interaction in mice. Higher severity PD in the genetically inflammation prone acute inflammatory reactivity maximum (AIRmax) mice strain was associated with higher levels of TNF-alpha, IL-1beta, IL-17, matrix metalloproteinase (MMP)-13, and RANKL, whereas PD/PIA co-induction resulted in even higher levels of IL-1beta, IFN-gamma, IL-17, RANKL, and MMP-13 levels. Conversely, PD/PIA co-induction in AIRmin strain did not alter the course of both pathologies. PIA/PD co-induction resulted in altered expression of T-cell subsets transcription factors expression, with T-bet and RORgamma levels being upregulated, whereas GATA-3 levels were unaltered. Interestingly, PIA induction resulted in alveolar bone loss, such response being highly dependent on the presence of commensal oral bacteria. No differences were found in PIA severity parameters by PD co-induction. Our results show that the interaction between experimental PD and arthritis in mice involves a shared hyper-inflammatory genotype and functional interferences in innate and adaptive immune responses.

Periodontitis and arthritis interaction in mice involves a shared hyper-inflammatory genotype and functional immunological interferences

Periodontitis (PD) and rheumatoid arthritis (RA) have been found to be clinically associated and to share the chronic nature of the inflammatory reaction associated with bone resorption activity. However, the mechanisms underlying such association areunknown. Therefore, we examined the basis of Actinobacillus actinomycetemcomitans- and Porphyromonas gingivalis-inducedPD and pristane-induced arthritis (PIA) interaction in mice. Higher severity PD in the genetically inflammation prone acute inflammatory reactivity maximum (AIRmax) mice strain was associated with higher levels of TNF-a, IL-1b, IL-17, matrix metalloproteinase (MMP)-13, and RANKL, whereas PD/PIA co-induction resulted in even higher levels of IL-1b, IFN-g, IL-17, RANKL, and MMP-13 levels. Conversely, PD/PIA co-induction in AIRmin strain did not alter the course of both pathologies. PIA/PD co-induction resulted in altered expression of T-cell subsets transcription factors expression, with T-bet and RORg levels being upregulated, whereas GATA-3 levels were unaltered. Interestingly, PIA induction resulted in alveolar bone loss, such response being highly dependent on the presence of commensal oral bacteria. No differences were found in PIA severity parameters by PD co-induction. Our results show that the interaction between experimental PD and arthritis in mice involves a shared hyper-inflammatory genotype and functional interferences in innate and adaptive immune responses.

Structural evaluation of the effects of chronic ethanol ingestion on the testis of Calomys callosus.

Chronic exposure to ethanol may results in pathophysiologic changes in cellular function. The present work was designed to investigate the morphology of testis submitted to experimental ethanol ingestion. Experimental animals were divided into two groups. The control group (n=23) received a solid diet and tap water and the alcoholic group (n=23) received the same solid diet and ethanol P.A. diluted 20% in water (v/v). After 120 days of treatment, all animals were anesthetized, weighed and sacrificed. Testosterone and luteinizing hormone levels in serum were lower in the alcoholic group than in the control group. Histological and ultrastructural alterations were observed in the testicular alcoholic germinative cells like enormous spaces, lipid droplets accumulation, digestive vacuoles, irregular diameter of the seminiferous tubules and interstitial dilated blood vessels. It was concluded that 20% ethanol provokes lesions on the testis germinative epithelium probably inducing gonadal dysfunction.

No relationship between subchronic fluoride intake and DNA damage in Wistar rats.

Fluoride has been widely used in dentistry because it is an effective caries prophylactic agent. However, excess fluoride may represent a hazard to human health, especially by causing injury on the genetic apparatus. Genotoxicity tests form an important part of cancer research and risk assessment of potential carcinogens. In the current study, the potential DNA damage associated with exposure to fluoride was assessed by the single cell gel (comet) assay in peripheral blood, oral mucosa and brain cells in vivo. Male Wistar rats were exposed to sodium fluoride (NaF) at a 0, 7 and 100 ppm dose for drinking water during 6 weeks. The results pointed out that NaF did not contribute to the DNA damage in all cellular types evaluated as depicted by the mean tail moment and tail intensity. These findings are clinically important since they represent an important contribution to the correct evaluation of the potential health risk associated with dental agents exposure.

Post-natal maturation of acinar cells of the guinea pig pancreas: an ultrastructural morphometric study.

The morphological maturation of the acinar cells of the guinea pig pancreas during post-natal development was characterized morphometrically by determining the intracytoplasmic accumulation of rough endoplasmic reticulum (RER) and zymogen granules. The following results were obtained for the period analysed, i.e., from 2 to 70 days of post-natal life: (a) the acinar cell volume increased by 210% (P < 0.01); (b) the mostly cisternal RER occupied more than 30% of the cytoplasm at any age studied and their total volume and surface in the cell were increased by 300 and 534% (P < 0.01), respectively; (c) maturation in the morphological pattern of the RER was observed; (d) the mean number of zymogen granules per cell increased from 261 at 2 days to 422 at 70 days (P < 0.01), while their mean diameter increased from 0.52 to 0.94 micron (P < 0.01) during the same period; (e) these increases in granule number and size were responsible for a 500% (P < 0.01) increase in total volume from 2 to 70 days and for a 304% increase (P < 0.01) in total surface from 2 to 35 days; (f) the RER and the zymogen granules together occupied 44, 54, 55 and 57% of the cytoplasm at 2, 14, 35 and 70 days of age, respectively. We conclude that although the pancreatic acinar cells of the guinea pig are morphologically well differentiated at 2 days of age, with the cytoplasm already showing a large amount of RER and zymogen granules, they are still immature. Morphological maturation of the acinar cell occurs during the first months of post-natal life and is characterized by a substantial gain in cell volume and intracytoplasmic accumulation of RER and zymogen granules, which significantly increase of both their absolute volume and total surface, with a higher growth rate being observed during the period from 2 to 14 days of post-natal life.

Allometric analysis of the postnatal development of the Syrian golden hamster pancreas.

The objective of the present study was to analyse allometrically the growth of the Syrian golden hamster pancreas during days 2 to 70 of postnatal development. Body and pancreatic mass were determined, followed by stereological determination of the absolute volume of each morphological compartment of the pancreas. The marked pancreatic growth, by 4360%, was due to an increase in the absolute volume of all morphological compartments, mainly the acini which showed an increase of 10 431%. Bivariate allometric analysis of pancreatic mass and morphological compartmental volume in relation to body mass gain showed: (1) a biphasic pattern for pancreatic mass, acinar volume, excretory duct volume and stromal volume, with the first phase being observed from 2 to 21 days of age and the second from 21 to 70 days of age, with allometry coefficients of 1.537-0.513, 1.770-0.543, 1.651-0.506 and 0.967-0.258, respectively, and (2) a monophasic pattern from 2 to 70 days for intercalated duct volume and islet volume, with allometry coefficients of 0.913 and 1.727, respectively. These results show that during the growth of the pancreas in relation to that of the body some structures - acini and excretory ducts - follow the growth pattern of the organ, while others - intercalated ducts and islets - show a different pattern. This may be related to the genetic growth characteristics of each compartment itself or to some relationship between compartments during some stage of the ontogenetic development of this organ.

Morphometric dimensions of Syrian golden hamster pancreas of both sexes.

The morphometric dimensions of the various structures of the pancreas of adult Syrian golden hamsters, of both sexes, were evaluated using stereological methods. The average body mass of the animals used was 133.8 +/- 2.45 g and 140.6 +/- 7.98 g for the males and females, respectively, and the pancreatic mass, 389.9 +/- 14.88 and 409.7 +/- 21.42 mg, respectively. The analysis of variance of the obtained data showed that: a) the acini, intercalated ducts and stroma did not present statistically significant differences in any of the dimensions evaluated, with the exception of the nucleus volume of the acinar cells which was 8.5% larger in the female (P < 0.05); b) the excretory ducts exhibited surface density, total external surface, surface-to-volume ratio, and absolute cell number, 18%, 33%, 14%, and 44%, respectively, larger in the females (P < 0.05); and c) the pancreatic islets of the females exhibited volume density, total volume and absolute cell number, 20%, 27% and 27%, respectively, larger than those of the males (P < 0.05).

[Ultrastructural morphometric study of sex dimorphism in cells of the ductus granulosus of the submandibular glands of mice]. / Estudo morfométrico ultra-estrutural do dimorfismo sexual em células de ductos granulosos de glândulas submandibulares de camundongos.

The sexual dimorphism in the secretory cell of the granular convolated tubule of mouse submandibular gland was morphometrically studied in light and electronic microscope level. In semithin sections (0.5 micron) the nuclear volume (Bach, 1963) and the fractions of cellular volume occupied by the nucleus and by cytoplasm were determined (Chalkley, 1943). In twenty electronmicrographs per animal with a final magnification of x 15.000, using the Weibel's et al. (1966) multiproposition test system, were obtained relatives morphometrics data, which multiplied by the cytoplasmatic volume provided us the respective absolute values. The results showed a presence of a sexual dimorphism at subcellular level. The secretory cell of the male is higher and exhibit a greater volume when compared with that cells of the female. In the male that cells are characterized by a higher total volume of the endoplasmic reticulum, Golgi complex and secretory granules. The secretory granules and the condensation vacuoles size are more developed in male cells. The female secretory granular cells exhibit a greater absolute number of the condensation vacuoles and secretory granules, as well as, a higher mitochondria total volume and surface.