A histomorphometric study of osteocytic lacunae in interradicular bone with periodontal disease.

Previous studies report on the differences in volume of osteocytic lacunae that are associated to different local and systemic bone pathologies. Alterations have also been reported in rats with periodontal disease. The aim of the present study was to assess the histomorphometric pattern of osteocytic lacunae of the interradicular septum in human molars with periodontal disease (PD). We took samples of the interradicular septum of 31 molars with indication of extraction of male and female patients, 18-55 years old, who attend the Department of Surgery II of the Faculty of Dentistry, National University of Cordoba and private centers. Clinical records were prepared for each patient. The corresponding radiographs were taken for all the patients. We studied 11 samples of molars with slight PD and 12 control molars free from PD. Ten samples of healthy bone corticals of vestibular or lingual tables obtained from histopathology archives were also assessed. Following extraction with atraumatic pincers, the interradicular septum was removed. The samples were fixed in buffered formaline, decalcified in EDTA and embedded in paraffin. Ten micrometer sections were stained with H&E and Masson's trichromic technique. The sections were analyzed by light microscopy. A minimum of 50 lacunae were selected at random in each sample for histomorphometric evaluation. Semi-automatic evaluation of the area and diameters of the lacunae was performed employing an image analyzer and the PRO IMAGE PLUS software. The data showed that the volume of osteocytic lacunae of interradicular bone is larger than that of the cortical bone of the vestibular or lingual tables. The latter are more ribbon-shaped and their minor diameter is smaller. No differences were found between the osteocytic lacunae of the interradicular bone of healthy molars and that of molars with slight periodontal disease. Given that the experimental data evidenced volume changes in osteocytic lacunae of severe, inflammatory periodontal lesions, it would be interesting to examine the volume changes in osteocytic lacunae in patients with varying degrees of periodontal disease to examine the role of osteocytes in the development and progression of periodontal disease.

A histomorphometric study of osteocytic lacunae in interradicular bone with periodontal disease

Previous studies report on the differences in volume of osteocytic lacunae that are associated to different local and systemic bone pathologies. Alterations have also been reported in rats with periodontal disease. The aim of the present study was to assess the histomorphometric pattern of osteocytic lacunae of the interradicular septum in human molars with periodontal disease (PD). We took samples of the interradicular septum of 31 molars with indication of extraction of male and female patients, 18-55 years old, who attend the Department of Surgery II of the Faculty of Dentistry, National University of Cordoba and private centers. Clinical records were prepared for each patient. The corresponding radiographs were taken for all the patients. We studied 11 samples of molars with slight PD and 12 control molars free from PD. Ten samples of healthy bone corticals of vestibular or lingual tables obtained from histopathology archives were also assessed. Following extraction with atraumatic pincers, the interradicular septum was removed. The samples were fixed in buffered formaline, decalcified in EDTA and embedded in paraffin. Ten micrometer sections were stained with H&E and Masson’s trichromic technique. The sections were analyzed by light microscopy. A minimum of 50 lacunae were selected at random in each sample for histomorphometric evaluation. Semi-automatic evaluation of the area and diameters of the lacunae was performed employing an image analyzer and the PRO IMAGE PLUS software. The data showed that the volume of osteocytic lacunae of interradicular bone is larger than that of the cortical bone of the vestibular or lingual tables. The latter are more ribbon-shaped and their minor diameter is smaller. No differences were found between the osteocytic lacunae of the interradicular bone of healthy molars and that of molars with slight periodontal disease. Given that the experimental data evidenced volume changes in osteocytic lacunae of severe, inflammatory periodontal lesions, it would be interesting to examine the volume changes in osteocytic lacunae in patients with varying degrees of periodontal disease to examine the role of osteocytes in the development and progression of periodontal disease.

A histomorphometric study of osteocytic lacunae in interradicular bone with periodontal disease.

Previous studies report on the differences in volume of osteocytic lacunae that are associated to different local and systemic bone pathologies. Alterations have also been reported in rats with periodontal disease. The aim of the present study was to assess the histomorphometric pattern of osteocytic lacunae of the interradicular septum in human molars with periodontal disease (PD). We took samples of the interradicular septum of 31 molars with indication of extraction of male and female patients, 18-55 years old, who attend the Department of Surgery II of the Faculty of Dentistry, National University of Cordoba and private centers. Clinical records were prepared for each patient. The corresponding radiographs were taken for all the patients. We studied 11 samples of molars with slight PD and 12 control molars free from PD. Ten samples of healthy bone corticals of vestibular or lingual tables obtained from histopathology archives were also assessed. Following extraction with atraumatic pincers, the interradicular septum was removed. The samples were fixed in buffered formaline, decalcified in EDTA and embedded in paraffin. Ten micrometer sections were stained with H&E and Massons trichromic technique. The sections were analyzed by light microscopy. A minimum of 50 lacunae were selected at random in each sample for histomorphometric evaluation. Semi-automatic evaluation of the area and diameters of the lacunae was performed employing an image analyzer and the PRO IMAGE PLUS software. The data showed that the volume of osteocytic lacunae of interradicular bone is larger than that of the cortical bone of the vestibular or lingual tables. The latter are more ribbon-shaped and their minor diameter is smaller. No differences were found between the osteocytic lacunae of the interradicular bone of healthy molars and that of molars with slight periodontal disease. Given that the experimental data evidenced volume changes in osteocytic lacunae of severe, inflammatory periodontal lesions, it would be interesting to examine the volume changes in osteocytic lacunae in patients with varying degrees of periodontal disease to examine the role of osteocytes in the development and progression of periodontal disease.

Avian minor salivary glands: an ultrastructural study of the secretory granules in mucous and seromucous cells.

Ultrastructural descriptions in birds are scarce thus, in this study we have characterized the secretory granules of mucous and seromucous cells from the palatine and lingual salivary glands of birds with different diets. The samples were taken from the tongue and palatine mucosa of chicken (Gallus gallus), quail (Coturnix coturnix), chimango (Milvago chimango) and white heron (Egretta thula). The samples were processed for observation by transmission electron microscopy (TEM) employing 4% Karnovsky solution for fixation. The most noteworthy finding was the heterogeneous ultrastructural appearance of the secretory granules. Differences in substructure were found between the four species, between the palatine and lingual glands in the same species and even within the same acinus and the same cell. At variance with other authors, these differences cannot be attributed to the type of fixative solution used taking into account that all the samples were processed in the same way. Previous histochemical studies have shown the presence of sulfated and non sulfated glycoconjugates in these glands which can be associated to the maturation of the granules. These granules are probably representative of peculiar storage of the secretory products that would give rise to a heterogeneous and complex ultrastructural pattern of granules in the mucosa and seromucosa cells of these avian species.

Avian minor salivary glands: an ultrastructural study of the secretory granules in mucous and seromucous cells

Ultrastructural descriptions in birds are scarce thus, in this study we have characterized the secretory granules of mucous and seromucous cells from the palatine and lingual salivary glands of birds with different diets. The samples were taken from the tongue and palatine mucosa of chicken (Gallus gallus), quail (Coturnix coturnix), chimango (Milvago chimango) and white heron (Egretta thula). The samples were processed for observation by transmission electron microscopy (TEM) employing 4

Karnovsky solution for fixation. The most noteworthy finding was the heterogeneous ultrastructural appearance of the secretory granules. Differences in substructure were found between the four species, between the palatine and lingual glands in the same species and even within the same acinus and the same cell. At variance with other authors, these differences cannot be attributed to the type of fixative solution used taking into account that all the samples were processed in the same way. Previous histochemical studies have shown the presence of sulfated and non sulfated glycoconjugates in these glands which can be associated to the maturation of the granules. These granules are probably representative of peculiar storage of the secretory products that would give rise to a heterogeneous and complex ultrastructural pattern of granules in the mucosa and seromucosa cells of these avian species.

Avian minor salivary glands: an ultrastructural study of the secretory granules in mucous and seromucous cells.

Ultrastructural descriptions in birds are scarce thus, in this study we have characterized the secretory granules of mucous and seromucous cells from the palatine and lingual salivary glands of birds with different diets. The samples were taken from the tongue and palatine mucosa of chicken (Gallus gallus), quail (Coturnix coturnix), chimango (Milvago chimango) and white heron (Egretta thula). The samples were processed for observation by transmission electron microscopy (TEM) employing 4

Karnovsky solution for fixation. The most noteworthy finding was the heterogeneous ultrastructural appearance of the secretory granules. Differences in substructure were found between the four species, between the palatine and lingual glands in the same species and even within the same acinus and the same cell. At variance with other authors, these differences cannot be attributed to the type of fixative solution used taking into account that all the samples were processed in the same way. Previous histochemical studies have shown the presence of sulfated and non sulfated glycoconjugates in these glands which can be associated to the maturation of the granules. These granules are probably representative of peculiar storage of the secretory products that would give rise to a heterogeneous and complex ultrastructural pattern of granules in the mucosa and seromucosa cells of these avian species.

An experimental model to study implant corrosion.

Corrosion phenomena would appear to play a decisive role in metallic implant long term behaviour. This study presents a method to correlate results obtained in "in vivo" and "in vitro" studies on materials used for metallic implants. Samples of titanium and copper immersed in saline solution (pH 7.4 and 5.2) were used for the "in vitro" study. Implants of these same materials were placed in rat tibiae following the method previously described by Cabrini et al. The animals were killed 14 days post-implantation, the tibiae were resected, radiographed and embedded in acrylic resin. Polarization curves revealed high corrosion in copper implants and low corrosion in titanium implants. It is important to point out that the titanium samples suffered slightly higher corrosion when immersed in a lower pH medium (pH 5.2), as in chronic inflammatory processes. A passive film was found on titanium samples as opposed to the strong corrosion observed in the copper implants. Microscopy revealed osseointegration around titanium implants and a severe inflammatory reaction with abscesses surrounding the copper implants. The method presented herein would allow to correlate "in vivo" and "in vitro" studies on corrosion in different implant materials and establish their relation with cell response.

An experimental model to study implant corrosion

Corrosion phenomena would appear to play a decisive role in metallic implant long term behaviour. This study presents a method to correlate results obtained in [quot ]in vivo[quot ] and [quot ]in vitro[quot ] studies on materials used for metallic implants. Samples of titanium and copper immersed in saline solution (pH 7.4 and 5.2) were used for the [quot ]in vitro[quot ] study. Implants of these same materials were placed in rat tibiae following the method previously described by Cabrini et al. The animals were killed 14 days post-implantation, the tibiae were resected, radiographed and embedded in acrylic resin. Polarization curves revealed high corrosion in copper implants and low corrosion in titanium implants. It is important to point out that the titanium samples suffered slightly higher corrosion when immersed in a lower pH medium (pH 5.2), as in chronic inflammatory processes. A passive film was found on titanium samples as opposed to the strong corrosion observed in the copper implants. Microscopy revealed osseointegration around titanium implants and a severe inflammatory reaction with abscesses surrounding the copper implants. The method presented herein would allow to correlate [quot ]in vivo[quot ] and [quot ]in vitro[quot ] studies on corrosion in different implant materials and establish their relation with cell response.

An experimental model to study implant corrosion.

Corrosion phenomena would appear to play a decisive role in metallic implant long term behaviour. This study presents a method to correlate results obtained in [quot ]in vivo[quot ] and [quot ]in vitro[quot ] studies on materials used for metallic implants. Samples of titanium and copper immersed in saline solution (pH 7.4 and 5.2) were used for the [quot ]in vitro[quot ] study. Implants of these same materials were placed in rat tibiae following the method previously described by Cabrini et al. The animals were killed 14 days post-implantation, the tibiae were resected, radiographed and embedded in acrylic resin. Polarization curves revealed high corrosion in copper implants and low corrosion in titanium implants. It is important to point out that the titanium samples suffered slightly higher corrosion when immersed in a lower pH medium (pH 5.2), as in chronic inflammatory processes. A passive film was found on titanium samples as opposed to the strong corrosion observed in the copper implants. Microscopy revealed osseointegration around titanium implants and a severe inflammatory reaction with abscesses surrounding the copper implants. The method presented herein would allow to correlate [quot ]in vivo[quot ] and [quot ]in vitro[quot ] studies on corrosion in different implant materials and establish their relation with cell response.

Effects of colchicine on parotid gland: structural and biochemical studies.

The present study involves the analysis of structural, ultrastructural and biochemical modifications induced by colchicine (Col) in Guinea Pig parotid gland. The biochemical studies showed that the highest concentration of soluble proteins occurred 4 hs after colchicine injection. The curve of a-amylase activity in the gland showed an increase in enzyme activity over control at approximately 4 hs post-injection. At 8 hours the rise was even greater. The structural and ultrastructural analyses of the gland revealed that 4 hs post-injection colchicine exerts its maximum inhibitory effect on secretion. At this treatment time, the cytoplasm contained granules of various sizes and sharp outlines. Large areas of the cytoplasm exhibited material which resembled the granular content and seemed to result from the fusion of granules. No secretion was found in the lumen of the ducts. The inhibitory effect on secretion would be due to the disassembly of microtubules which would in turn impair transport of the granules to the apical surface of the membrane and eventual exocytosis. We herein propose that the effects of colchicine in the experimental conditions of this study would be largely reversible at 24 hours. At this time, structural, ultrastructural and biochemical features were similar to those of controls.

Structural and biochemical modifications in parotid gland induced by fasting.

Structural, ultrastructural and biochemical modifications produced by fasting in the parotid gland of guinea pig, were studied. The highest storage of secretory granules was found in the apical cytoplasm after a 12 hour fasting period. The curve of soluble proteins showed that the highest storage of proteins in the parenchyma took place after a 10/12 hour fasting period. Amylase activity reached its highest point after a 10 hour fasting period. We suggest that granules stored in cellular cytoplasm after a 12 hour fasting period would have completed their maturation cycle.

[Dentinopulpar organ: biological basis of clinical response to Ca(OH)2 application]. / Organo dentino pulpar: fundamentos biológicos acerca de la respuesta clínica por aplicación de Ca(OH)2.

We have studied the changes presented by mediate and immediate roentgenographic images of indirect pulp capping and pulpotomies. In the cases of indirect pulp capping it was observed an increase of radiolucidity in the places occupied by Ca(OH)2, and sclerotic dentin was present. In pulpotomies, it was found the dentin bridge, which thickness increases with time. The radiolucidity of pulp chamber occupied by Ca(OH)2 was greater in the long time treatment. The radiopacity of non-vital dentin of walls and floor chamber was increased too. It has suggested that Ca++ ion would have migrated from its place and probably would take part in the synthesis of sclerotic dentin, independently of the vitality of the tissue.