Maxillary Sinus Augmentation Using Prehydrated Corticocancellous Porcine Bone: Hystomorphometric Evaluation after 6 Months

Background: Insufficient alveolar bone height often prevents the placement of standard dental implants in the posterior part of edentulous maxilla. In order to increase adequately the vertical dimension of the reabsorbed alveolar process, a sinus lift procedure is often necessary. The aim of this study was to evaluate histologic results of a prehydrated corticocancellous porcine bone used in maxillary sinus augmentation. Methods: Patients (age 18–70 years) with a residual bone height requiring a maxillary sinus augmentation procedure to place dental implants were eligible for this study. All patients were treated with the same surgical technique consisting of sinus floor augmentation via a lateral approach. The space obtained by elevation of the mucosa wall was grafted with prehydrated and collagenated corticocancellous porcine bone. Biopsies were harvested 6 months after the augmentation procedures. Results: Twenty‐four patients were enrolled. The mean percentage of new formed bone was 43.9 ± 18.6% (range 7.5–100%), whereas the mean percentage of residual graft material was 14.2 ± 13.6% (range 0–41.9%). The new bone/residual graft material ratio in the maxillary sinuses was 3.1. The mean soft tissues percentage was 41.8 ± 22.7% (range 0–92.5%). Conclusion: The present study suggested that porcine bone showed excellent osteoconductive properties and could be used successfully for sinus augmentation. Moreover, the porcine bone showed a high percentage of reabsorption after 6 months; this might be because of the presence of collagen and the porosity of the graft material.     

Effects of partial hepatectomy on extrarenal erythropoietin production in rats

Studies were performed to determine the effects of partial hepatectomy on extra-renal erythropoietin production. Rats were either partially hepatectomized or sham operated. At intervals of from 5 min to 7 days afterward, both kidneys were removed from cohorts of the above two groups of rats and the animals were then exposed to hypoxia for 7.5 hr. Immediately afterward, their plasma was collected and its erythropoietin titer was assayed. Rats which were partially hepatectomized 2-4 days prior to nephrectomy and hypoxia had significantly higher plasma erythropoietin levels than did sham- operated controls, whereas rats hepatectomized 5 min, 1 day, or 7 days prior to nephrectomy and hypoxia did not. These data are consistent with the conclusion that extrarenal erythropoietin production is enhanced in association with rapid regeneration of hepatic cells.     

HCV serotypes in Brazilian patients.

OBJECTIVE: To investigate the prevalence of the different types of hepatitis C virus (HCV) in a population of chronic HCV carriers using the Murex HCV serotyping 1-6 assay. METHODS: All serum samples from these patients had a positive nested PCR HCV reaction. The sera were submitted to ELISA, modified, for the identification of antibodies against HCV serotypes 1, 2, 3, 4, 5 and 6 (Murex HCV serotyping 1-6 assay). RESULTS: The viral serotype was identified in 166 (75.8%) of the 219 patients, 108 (65.11%) males and 58 (34.9%) females. Patient age ranged from 12 to 73 years, with a mean of 41.1 years. The form of acquisition of the disease most frequently reported was blood transfusion. The results showed a predominance of type 1 (70.0%), followed by type 3 (22.3%) and type 2 (4.2%). CONCLUSION: Samples presenting low and very close optical density readings may lead to discrepant diagnoses concerning HCV serotypes and should be confirmed by genotyping. The serotyping can be useful in clinical practice and can be of help in establishing the prognosis of the disease, also favoring epidemiologic studies independently of the technology required for genotyping tests.     

DA1 receptor mediates dopamine-induced relaxation of opossum lower esophageal sphincter in vitro

The objective of the present experiments was to determine the specific receptor subtype through which dopamine (DA) receptor agonists relax the lower esophageal sphincter in vitro. Opossum lower esophageal sphincter smooth muscle strips were placed in oxygenated Krebs' solution containing propranolol and cocaine. The tissues were placed at a tension that gave maximum relaxation to electrical field stimulation and were then pretreated with phenoxybenzamine. The effects of DA, and the DA receptor agonists epinine and apomorphine were determined. In addition, agonist responses were studied in the presence of the selective DA2 receptor antagonist domperidone, a mixed DA1/DA2 receptor antagonist metoclopramide, and the selective DA1 receptor antagonists bulbocapnine and SK&F 83566. The DA agonists relaxed the smooth muscle strips in the following order of potency: DA greater than epinine greater than apomorphine. Domperidone did not antagonize DA- or apomorphine-induced relaxation. Metoclopramide failed to alter DA-induced relaxation. Bulbocapnine and SK&F 83566 significantly inhibited the relaxation induced by DA. These data indicate that DA-induced lower esophageal sphincter relaxation in vitro is mediated by DA1 receptors.     

ER-β expression in large bowel adenomas: Implications in colon carcinogenesis

BACKGROUND: A pivotal role of oestrogen receptor-beta has been suggested in colon carcinogenesis in humans. However, few data are available on oestrogen receptor-beta in colorectal pre-cancerous lesions. AIM: In the present study, we evaluated oestrogen receptor-beta expression and its possible correlation with proliferative activity and apoptosis in colorectal adenomas and normal colon tissue. PATIENTS/METHODS: Adenomatous tissue from 25 patients with colonic polyps, and normal tissue from 25 controls were used. Oestrogen receptor-beta expression, colonocyte proliferation (expressed as PCNA positivity) and apoptosis were evaluated. RESULTS: In adenomatous tissue, a significant reduction of oestrogen receptor-beta was observed compared to normal mucosa (10.1+/-5.5% vs. 44.2+/-13.7; p<0.03), while the expression of oestrogen receptor-alpha remained unvaried. Cell proliferative activity significantly increased in adenomatous tissue compared to normal mucosa (59.3+/-7.1 vs. 18.5+/-8.8; p<0.0001), doubling the PCNA/apoptosis ratio. An inverse correlation was found between oestrogen receptor-beta and PCNA expression in adenomas (r=-0.81), a datum confirmed by confocal microscopy evaluation. CONCLUSIONS: Our data demonstrate, for the first time, a significant reduction of oestrogen receptor-beta expression already in the pre-cancerous phase of colon carcinogenesis. This suggests a role of selective oestrogen receptor-beta agonists in the prevention of colorectal cancer.