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.

Polimorfismos genéticos da kappa-caseína e da beta-lactoglobulina e produção de leite em bovinos / Kappa-casein and beta-lactoglobulin genetic polymorphisms and milk yield in bovines

As variantes gênicas da beta-lactoglobulina (β-LG) e da kappa-caseína (κ-CN) bovinas são associadas à produção, qualidade e características de processamento do leite. O objetivo deste trabalho foi analisar as frequências dos genótipos AA, AB e BB, por meio da técnica de PCR-RFLP, da β-LG e da κ-CN bovinas, e suas associações com a produção de leite (kg leite/dia) em bovinos das raças Girolanda, Holandesa e Jersey. Para a κ-CN, a frequência do genótipo AA foi maior nos animais das raças Holandesa (37%) e Girolanda (63%). Na raça Jersey, houve predomínio do genótipo BB (60%). Para a β-LG, o genótipo AB foi o mais encontrado nas raças Girolanda (54%) e Holandesa (58%), enquanto nos animais da raça Jersey houve predomínio do genótipo BB (45%). Houve associação do alelo B da κ-CN com maior produtividade leiteira nas raças Girolanda e Holandesa, e do alelo A da β-LG com maior produtividade de leite na raça Jersey. As variantes genéticas da κ-CN podem ser usadas como marcadores na seleção para a produtividade leiteira nas raças Girolanda e Holandesa. Para a raça Jersey, as variantes da β-LG seriam mais adequadas para essa seleção.

Bovine beta-lactoglobulin (β-LG) and kappa-casein (κ-CN) genic variants are associated with productivity, quality and processing features of milk. The objective of this study was to analyze through the PCR-RFLP technique, the frequency of AA, AB and BB genotypes of bovine β-LG and κ-CN, and their association to milk production (kg milk/day) in Girolanda, Holstein and Jersey cattle. For κ-CN, the frequency of the AA genotype was higher in Holstein (37%) and Girolanda (63%), while there was a predominance of the BB genotype in Jersey (60%). For β-LG, the BB genotype was the most found in Girolanda (54%) and Holstein (58%), while there was a predominance of the BB genotype (45%) in Jersey. There was a positive association between B allele of κ-CN and milk production in the Girolanda and Holstein cattle and between A allele of β-LG and milk production in the Jersey cattle. Genetic variants of κ-CN could be used as markers for the selection for productivity in Girolanda and Holstein cattle. The genetic variants of β-LG would be more appropriate for this selection in the Jersey breed.

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.

Gastroesophageal reflux disease: New oral findings.

OBJECTIVE: The objective of this study was to investigate the effects of gastroesophageal reflux disease (GERD) on dentition, salivary function, and oral mucosa. STUDY DESIGN: Thirty-one patients with esophagitis underwent medical evaluation, which included taking their medical history, performing both an esophagogastroduodenoscopy and esophagus biopsy, and conducting a stomatologic examination. The latter consisted of an extraoral and intraoral physical examination, saliva tests (flow, buffer capacity, and pH), and biopsy and morphometry of the palatal mucosa, as well as taking a history of the patients' habits. Fourteen healthy volunteers from the same population were used as a control group. RESULTS: No relationship between GERD and changes in the oral cavity was shown by saliva tests, oral clinical examination, or histopathologic examination of the palatal mucosa. However, morphometric analysis of the palatal epithelium showed a statistically significant difference between the patients with GERD and the control group. CONCLUSIONS: GERD is associated with microscopic alterations in the palatal mucosa (epithelial atrophy and increased fibroblast number), which are only detected by morphometry.

Observation of Oriented Close-Packed Lattice Planes in Polycrystalline Hard-Sphere Solids.

We report time-resolved Bragg scattering experiments on solidifying colloidal suspensions of hard spheres. The polar angle-averaged, integrated intensity of the (111) and (311) reflections show a transient, two-step behavior below melting, which depends in a complex way on the volume fraction and is not present for (200) or (220). Detailed analysis of the full two-dimensional scattering pattern reveals intensity maxima of sixfold symmetry close to the position of the (111) and (311) Debye-Scherrer rings. These can be explained assuming oriented crystals with close-packed planes parallel to the container walls. We show that the observed temporal behavior is due to competing homogeneous and heterogeneous nucleation and growth scenarios. Copyright 1998 Academic Press.

Limb girdle muscular dystrophy: a prospective follow-up study of functional impairment.

This 6-year prospective follow-up study evaluated the rate of clinical disease progression in 19 of 20 previously reported patients with strictly selected limb girdle muscular dystrophy. There was no significant deterioration in muscle strength (assessed by manual muscle testing). An activities of daily living (ADL) scale showed significant functional deterioration in 30% of patients with predominant involvement in a single functional domain variable between patients, and determined by the patient's previous level of function. A functional grading system showed that 70% of patients had deteriorated at least one grade in the arms and/or legs. Deterioration of the ADL score correlated with the loss of functional grades. We conclude that assessment of functional ability may be more sensitive to detect clinical disease progression compared to testing of muscle strength. The clinical parameter that correlates best with the activity of the underlying disease process is not determined. Tests for strength and functional impairment are complementary. Patients expressed appreciation that functional disability was addressed during follow-up visits.

[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.

Ultrastructure of the secretory compartment of the Rana catesbeiana exocrine pancreas.

In the Rana catesbeiana exocrine pancreas 2 types of serozimogenic cells could be observed. They were called light and dark cells. The light cells were observed in a greater number and presented the GER cisterns predominantly located in the basal region of the cell and the vesicular forms of the GER mainly in the supranuclear region. The Golgi complex was well developed and the secretory granules were grouped in the cell apex. The mitochondrion were distributed by the cytoplasm and the nucleous appeared in the basal region of the cell and presented a pale and vesiculous profile that made the nucleolus evident. The dark cells were observed in smaller quantity and in this cell occurred a predominance of GER vesicles. The cytoplasmic matrix presented an electron-dense appearance and a large quantity of free ribosomes. The Golgi complex is poorly developed, the secretory granules and the mitochondria are scarce. We could observe besides the light and dark cells, the centroacinar and the intermediate cells. The centroacinar cells lay in the luminal border of the acinar cells. They presented an electron-lucent cytoplasmic matrix where could be noted a few GER profiles and the secretory granules were absent. The intermediate cells showed, intermingled within the same cell, the zimogenic and the endocrine-like alfa and beta Langerhans granules.

Quantitative description of a teleost exocrine pancreas. Ultrastructural morphometric study of nonstimulated acinar cells.

The quantitative analysis of exocrine pancreas was fulfilled in teleost fish ( Pimelodus maculatus). The volume fraction occupied by acinar cells, blood vessels and ducts has been assessed by point-counting volumetry in 0.25 micron araldite sections. Measurements of the diameters of the transections of acinar cells nuclei and nucleolus allowed the assessment of the mean nuclear and nucleolar volume according to the method of Bach (1963). With these data, the cytoplasm nuclei and nucleolus volume was calculated in cubic micrometers. Morphometric ultrastructural data was obtained by applying over the electronmicrophotographs (X 21,000) a test system of 84 segments regularly spaced one from another (Weibel 1966). The results obtained was analysed and compared to the mammalian.

Electron microscopic study of teleost (Pimelodus maculatus) pancreatic islet cells.

The endocrine pancreas of the freshwater teleost Pimelodus maculatus was studied by electron microscopy. Based on the granule morphology 2 cell types were described: Secretory granules of type I cells are rounded, nearly completely filling the limiting membranous sac which measures from 120 to 150 nm in diameter; the type II granules are also rounded and measure from 220 to 270 nm in diameter; they consist of an eccentrical electron dense core separated from the limiting membrane by a wide electron lucent halo. These characteristics are correlated with those found in other teleosts.

Fine structural analysis of a teleost exocrine pancreas cellular components - a freeze-fracture and transmission electron microscopic study.

The normal exocrine pancreas of Pimelodus maculatus (Teleostei) has been studied by freeze-fracture and conventional transmission electron microscopy. 4 cellular types in the acini are observed: the acinar cells, the argentaffin cells, the intermediate cells and the centroacinar cells. The most proeminent cytoplasmic feature of the acinar cells is that the well developed rough endoplasmic reticulum, which appear predominantly under the vesicular form. The argentaffin cells are found lodged between the acinar cells and duct cells, in the connective tissue they are isolated principally that surrounds the ducts. The typical granules are the cytoplasmic component wich characterize the argentaffin cells. The indermediate cells are characterized by the presence of two distinct granule types: one resembling that found in the endocrine cells and the other resembling the granules of the acinar cells. The centroacinar cells is similar that found in other species.

Histochemical (polysaccharides, proteins, nucleic acids and enzymes) and autoradiographic (incorporation of 35S labelled sodium sulfate) study of the epithelial intestinal cells of Xenodon merremii Wagler, 1824 (Ophidia).

A histochemical and autoradiographic study of the lining intestinal epithelium of the snake Xenodon merremii is reported. The absorptive cells present neutral polysaccharides, arginine, tyrosine, tryptophan, cysteine, alkaline phosphatase, acid phosphatase, ATPase, AMPase, esterase and RNA. There are histochemical differences between the goblet cells of the small and of the large intestine. Whereas in the former predominates the neutral polysaccharides and are found arginine, tyrosine, tryptophan and cysteine, in the latter predominates the sulfated polysaccharides (confirmed by the uptake of radioactive sulfur) and no amino acids were found.

Ultrastructure of the epidermal cells of the teleost Pimelodus maculatus Lacépède, 1803 (pisces).

By means of electronmicroscope technique were studied the cell types in the epidermis of the teleost Pimelodus maculatus LACEPEDE. The varied cells were described after their morphological aspect. The behaviour of the plasma membrane and the cytoplasmatic components, especially the microfilaments and the rough endoplasmatic reticulum, were discussed in the functionally manner of this cells. The relationship of the cell types to the mitotic cell cycle gave some interesting references.