RESUMO

Objetivos. La sobreobturaci¨®n accidental o inadvertida con conos de gutapercha ocurre con cierta frecuencia en endodoncia cl¨ªnica. El prop¨®sito deeste estudio fue analizar la respuesta de los tejidos periapicales de la rata a sobreobturaciones intencionalesde conos de Resilon o conos de gutapercha recubiertos con resina. Material y m¨¦todos. Se obtuvo el acceso al conducto distal de los primeros molares inferiores (izquierdoy derecho) de 16 ratas macho Wistar con un peso de ¡À 250 g. Los conductos fueron preparados y sobreobturados con los materiales problema hasta una medida estandarizada de ¡À1 mm m¨¢s all¨¢ del ¨¢pice mediante el empleo de un localizador apical electr¨®nico. Las mand¨ªbulas fueron disecadas, fijadas en formol-buffer al 10 por ciento y descalcificadas. Los molares y los tejidos circundantes se prepararonpara su estudio histol¨®gico de rutina y se obtuvieron cortes seriados de aproximadamente 7 ¦Ìm de espesor de la ra¨ªz distal, los que fueron coloreadoscon hematoxilina y eosina. Los datos se categorizaron de acuerdo con par¨¢metros previamente establecidos y se analizaron mediante los tests deFisher, Kruskal-Wallis y el de comparaci¨®n m¨²ltiple de Dunn.Resultados. Luego de 30 d¨ªas la reacci¨®n a los materiales problema demostraron una respuesta inflamatoria moderada a severa. Estas reacciones disminuyeron significativamente (p<0.05) a los 90d¨ªas. En este lapso se observ¨® una reparaci¨®n progresiva de los tejidos periapicales circundada por un activo desarrollo de nuevas trab¨¦culas ¨®seas deapariencia normal. Conclusiones. Al finalizar la experiencia la reacci¨®n fue similar para ambos materiales, los que fueron bien tolerados por los tejidos periapicales, sin interferir con el proceso reparativo.

Assuntos

RESUMO

Objetivos. La sobreobturaci¿«n accidental o inadvertida con conos de gutapercha ocurre con cierta frecuencia en endodoncia cl¿¬nica. El prop¿«sito deeste estudio fue analizar la respuesta de los tejidos periapicales de la rata a sobreobturaciones intencionalesde conos de Resilon o conos de gutapercha recubiertos con resina. Material y m¿ªtodos. Se obtuvo el acceso al conducto distal de los primeros molares inferiores (izquierdoy derecho) de 16 ratas macho Wistar con un peso de í? 250 g. Los conductos fueron preparados y sobreobturados con los materiales problema hasta una medida estandarizada de í?1 mm m¿ós all¿ó del ¿ópice mediante el empleo de un localizador apical electr¿«nico. Las mand¿¬bulas fueron disecadas, fijadas en formol-buffer al 10 por ciento y descalcificadas. Los molares y los tejidos circundantes se prepararonpara su estudio histol¿«gico de rutina y se obtuvieron cortes seriados de aproximadamente 7 ªÌm de espesor de la ra¿¬z distal, los que fueron coloreadoscon hematoxilina y eosina. Los datos se categorizaron de acuerdo con par¿ómetros previamente establecidos y se analizaron mediante los tests deFisher, Kruskal-Wallis y el de comparaci¿«n m¿²ltiple de Dunn.Resultados. Luego de 30 d¿¬as la reacci¿«n a los materiales problema demostraron una respuesta inflamatoria moderada a severa. Estas reacciones disminuyeron significativamente (p<0.05) a los 90d¿¬as. En este lapso se observ¿« una reparaci¿«n progresiva de los tejidos periapicales circundada por un activo desarrollo de nuevas trab¿ªculas ¿«seas deapariencia normal. Conclusiones. Al finalizar la experiencia la reacci¿«n fue similar para ambos materiales, los que fueron bien tolerados por los tejidos periapicales, sin interferir con el proceso reparativo.(AU)

Assuntos

RESUMO

AIM: To investigate the effects of chronic drinking of cola beverages on metabolic and echocardiographic parameters in rats. METHODS: Forty-eight male Wistar rats were divided in 3 groups and allowed to drink regular cola (C), diet cola (L), or tap water (W) ad libitum during 6 mo. After this period, 50% of the animals in each group were euthanized. The remaining rats drank tap water ad libitum for an additional 6 mo and were then sacrificed. Rat weight, food, and beverage consumption were measured regularly. Biochemical, echocardiographic and systolic blood pressure data were obtained at baseline, and at 6 mo (treatment) and 12 mo (washout). A complete histopathology study was performed after sacrifice. RESULTS: After 6 mo, C rats had increased body weight (+7%, P < 0.01), increased liquid consumption (+69%, P < 0.001), and decreased food intake (-31%, P < 0.001). C rats showed mild hyperglycemia and hypertriglyceridemia. Normoglycemia (+69%, P < 0.01) and sustained hypertriglyceridemia (+69%, P < 0.01) were observed in C after washout. Both cola beverages induced an increase in left ventricular diastolic diameter (C: +9%, L: +7%, P < 0.05 vs W) and volumes (diastolic C: +26%, L: +22%, P < 0.01 vs W; systolic C: +24%, L: +24%, P < 0.05 vs W) and reduction of relative posterior wall thickness (C: -8%, L: -10%, P < 0.05 vs W). Cardiac output tended to increase (C: +25%, P < 0.05 vs W; L: +17%, not significant vs W). Heart rate was not affected. Pathology findings were scarce, related to aging rather than treatment. CONCLUSION: This experimental model may prove useful to investigate the consequences of high consumption of soft drinks.

RESUMO

The authors hypothesized that preeclampsia may change the phenotype of umbilical cord vessels. Segments of umbilical cords were obtained from 29 pregnant women (20 healthy and 9 with preeclampsia), which were histomorphometrically assessed. Birth weight was 2928 ± 613 g for the control group vs 1749 ± 656 g for the preeclampsia group (P<.0001). A significantly shorter gestational period was noted in the preeclampsia group: 35 weeks vs 39 weeks in the healthy group. Measurements of the outer layer area (116.4 ± 55 µm(2) vs 56.5±25 µm(2) ; P=.0038), the inner layer area (63.1 ± 16 µm(2) vs 28.6±8 µm(2) ; P<.0001), the lumen area (8.4 ± 1 µm(2) vs 3.4±2 µm(2) ; P=.0003), and the wall/lumen ratio (20.3 ± 9 vs 3.1 ± 0.6; P<.0001) of arteries were significantly larger in the preeclampsia umbilical cords. Concerning veins, the wall/lumen ratio was higher in the preeclampsia group. In this study, the umbilical cord in preeclampsia showed significant changes in the structure of umbilical arteries, with increases in wall areas and wall/lumen ratios.

Assuntos

RESUMO

INTRODUCTION: An evaluation was made of the connective tissue reaction in rats after subcutaneous implantation of methacrylate resin-based sealers (EndoREZ [Ultradent Products, Inc, South Jordan, UT] with a polymerization accelerator and RealSeal [Sybron Dental Specialties, Orange, CA]) and Pulp Canal Sealer (Sybron Dental Specialties), a zinc oxide and eugenol-based sealer used as the control. METHODS: Silicone tubes containing the test materials were implanted in 24 Wistar rats. Solid silicone rods of the same size served as the negative controls. After 10, 30, and 90 days, the animals (n = 8 per period) were euthanized and the implants with surrounding tissues dissected and processed for routine histological evaluation. A four-category evaluation system was used to measure and record the microscopic observations according to the thickness of a fibrous capsule, the vascular changes, and the various types of inflammatory cells. RESULTS: Initially, a severe inflammatory reaction was observed of the soft tissues in direct contact with both EndoREZ/Accelerator and Real Seal. The severity decreased over time and was resolved at the end of the experiment. Pulp Canal Sealer showed a severe tissue reaction for all observation periods. The negative controls showed an initial mild to moderate inflammatory reaction. After 30 days, healthy fibrous connective tissue was observed, which increased over time. After 10 days, no statistically significant differences between the experimental groups were observed. After 90 days, EndoREZ and RealSeal were statistically significantly less toxic than Pulp Canal Sealer (p > 0.05). CONCLUSIONS: After 90 days, both methacrylate resin-based sealers were considered biologically acceptable when implanted in subcutaneous connective tissues of the rat. Pulp Canal Sealer remained toxic for the duration of the study.

Assuntos

RESUMO

We performed a morphological characterization of intimal thickenings in coronary arteries in the very early stages of life to obtain insights into initial coronary atherogenesis. We examined specimens from 67 infants who had died of noncardiac causes within their first year of life. Serially cut sections were stained with hematoxylin-eosin, Azan, Alcian blue, acetic orceine, and immunotypified for CD68, CD34, and alpha-smooth muscle (SM) actin. Substantial changes were detected in about 1 of 3 participants. Alterations ranged from focal areas with mild myointimal thickening to diffuse moderate thickening. In those lesions, smooth muscle cells (SMCs) showed loss of polarity, infiltrating the subendothelium, mostly with rupture of the internal elastic lamina and without neoangiogenesis. Morphometrically, in musculoelastic intimal thickenings, neointimal thickness averaged 58.3 +/- 17.8 microm, affecting 46% of the internal elastic membrane perimeter; lumen stenosis averaged 13.7% +/- 5.0%. These lesions can be present very early in life and SMCs seem to play an essential role.

Assuntos

RESUMO

Dolichoarteriopathies consist of tortuosity, kinking, or coiling of the extracranial carotid arteries. Some authors consider these alterations a consequence of atherosclerotic vessel remodeling, while others ascribe them to anatomical variations of embryological origin. The objective was to establish whether carotid dolichoarteriopathies belonged to a congenital origin or to acquired conditions. Color Doppler ultrasonography of neck vessels was performed in 885 participants, whose age ranged from 1-day-old infants to 90-year-old adults. Prevalence of kinking and coiling was evaluated, and it was related to the presence of cardiovascular risk factors. Prevalence of either kinking or coil of carotid arteries showed no increase with age, as it was comparable across all ages; furthermore, frequency of these alterations showed no relationship to cardiovascular risk factors nor to the presence of atheromatous plaques. These findings suggest that carotid dolichoarteriopathies are a result of alterations in embryological development rather than vascular remodeling secondary to aging and/or atherosclerosis.

Assuntos

RESUMO

The purpose of this study was compare the biocompatibility of modified Portland cement (CPM) and mineral trioxide aggregate (MTA) in a subcutaneous rat model. Twenty-four male Wistar rats were used. Three silicon tubes were placed on the dorsal subcutaneous tissue of each animal: one tube contained MTA, one tube contained CPM and the other was an empty tube. The rats were sacrificed in 3 groups of 8 animals at 7, 14 and 30 postoperative days, respectively. Tissue samples were fixed in 10% buffered formalin, embedded in paraffin, and serial sections were cut and stained with hematoxylin and eosin, Masson Trichrome and Luna's stain. At day 7, the empty tubes displayed a mild inflammatory infiltrate. In the CPM group, an inflammatory infiltrate was observed with some eosinophils and immature connective tissue. The MTA group showed a similar infiltrate without eosinophils and presence of abundant necrotic tissue and numerous multinucleate foreign body giant cells. At day 14, the chronic infiltrate with eosinophils persisted when in contact with CPM. In the MTA group, necrosis and distant giant cells could still be seen. At day 30, all 3 groups showed mature fibrous collagenous tissue. These findings indicate a different response to the materials evaluated in this study. Although, MTA and CPM induced a chronic inflammatory infiltrate, necrosis and multinucleated foreign body giant cells predominated in the MTA group, while in the CPM group numerous eosinophils were seen at all the observational periods.

Assuntos

RESUMO

BACKGROUND: Carotid barochemoreceptor pathological lesions have been studied in animals, but few human necropsies have been performed. Therefore, data rely on case patients following surgery, radiotherapy and carotid endarterectomy. Almost no data are available regarding whether the effect of aging prevails over pathological conditions, despite the classic description that glomic fibrosis increases with age. OBJECTIVE: To morphometrically characterize the alterations of the carotid barochemoreceptors and their supplying arteries. METHODS: Patients (n=23) who had suffered and died from stroke, with and without complicated internal carotid atheromatosis, were divided by age (group 1: older than 80 years; group 2: 65 to 80 years; and group 3: younger than 65 years). Carotid segments were obtained at autopsy. The specimens were stained for light microscopy and immunohistochemistry. RESULTS: Carotid glomus presented from moderate-to-severe atrophy and fibrosis. A focal decrease in vascularization (CD34-positive) of the glomus (greater than 50%) was observed in areas of atrophy and fibrosis. Damaged nerve endings (S100 protein-positive) were observed at the media of the carotid sinus. Morphometric data showed no differences between groups for glomus area, number of type 1 and 2 cells, and the wall to lumen arteriole ratio. No statistical differences were demonstrated in the pathological findings of the carotid glomus when comparing complicated with noncomplicated plaques or age groups. CONCLUSION: Severe carotid chemoreceptor damage exists in patients who have died from stroke and suffered from carotid atheromatosis. These findings were independent from aging and plaque type. However, damage was correlated with a marked narrowing of the supplying arterioles as a consequence of hemodynamic and/or metabolic alterations (dyslipidemia, diabetes).

Assuntos

RESUMO

The purpose of this study was compare the biocompatibility of modified Portland cement (CPM) and mineral trioxide aggregate (MTA) in a subcutaneous rat model. Twenty-four male Wistar rats were used. Three silicon tubes were placed on the dorsal subcutaneous tissue of each animal: one tube contained MTA, one tube contained CPM and the other was an empty tube. The rats were sacrificed in 3 groups of 8 animals at 7, 14 and 30 postoperative days, respectively. Tissue samples were fixed in 10 percent buffered formalin, embedded in paraffin, and serial sections were cut and stained with hematoxylin and eosin, Masson Trichrome and Luna's stain. At day 7, the empty tubes displayed a mild inflammatory infiltrate. In the CPM group, an inflammatory infiltrate was observed with some eosinophils and immature connective tissue. The MTA group showed a similar infiltrate without eosinophils and presence of abundant necrotic tissue and numerous multinucleate foreign body giant cells. At day 14, the chronic infiltrate with eosinophils persisted when in contact with CPM. In the MTA group, necrosis and distant giant cells could still be seen. At day 30, all 3 groups showed mature fibrous collagenous tissue. These findings indicate a different response to the materials evaluated in this study. Although, MTA and CPM induced a chronic inflammatory infiltrate, necrosis and multinucleated foreign body giant cells predominated in the MTA group, while in the CPM group numerous eosinophils were seen at all the observational periods.

O propósito deste estudo foi comparar a biocompatibilidade do cimento Portland modificado (CPM) com agregado de trióxido mineral (MTA) no subcutâneo de um modelo murino. Foram usados 24 ratos Wistar macho. No tecido subcutâneo dorsal de cada animal se colocaram 3 tubos de silicone. Um contendo MTA, outro CPM e o último vazio. Os animais foram sacrificados em 3 grupos de 8 aos 7, 14 e 30 dias. As amostras se fixaram em formol e se coloriram com hematoxilina - eosina, Masson e Luna. No dia 7 os tubos vazios mostraram uma leve infiltração de células inflamatórias. No grupo CPM, se observou um infiltrado inflamatório com alguns eosinófilos e tecido conectivo imaturo. O grupo MTA mostrou um infiltrado similar sem eosinófilos e abundante necrose de tecido e numerosas células gigantes multinucleadas do tipo corpo estranho. Ao dia 14, o infiltrado crônico com eosinófilos persistiu em contato com CPM. No grupo MTA, a necrose e células multinucleadas afastadas ainda se podiam observar. Ao dia 30, os 3 grupos mostraram tecido fibroso maduro. Estes resultados mostram uma resposta diferente aos materiais avaliados no presente estudo. Apesar do que MTA e CPM causaram um infiltrado crônico, no grupo MTA predominou a necrose e as células gigantes, enquanto isso, no grupo CPM se observaram grandes quantidades de eosinófilos.

Assuntos