Evaluation of the 45-degree labial bevel with a shoulder preparation

This study compared the margin opening of cemented porcelain-fused-to-metal crowns of three different casting designs: 80-degree bevels with metal collars, 80-degree bevels with porcelain applied to the labial collars, and 45-degree labial bevels with metal and porcelain to a common margin termination. There were no statistically significant differences between the margin opening of the three groups. Porcelain application and firing did not distort the facial margin. The 45-degree bevel with porcelain to the margin has greater esthetic potential and the same margin adaptation as the 80-degree bevel with an all-metal collar.     

Synovial-type giant cell tumors of the vertebral column: a clinicopathologic study of 15 cases,with a review of the literature and discussion of the differential diagnosis

Synovial and tenosynovial giant cell tumors only rarely arise in close proximity to the axial skeleton; to date, fewer than 30 examples have been reported in the English-language medical literature. In this report we describe the clinical, radiologic, histopathologic, and immunohistochemical findings in 15 cases retrieved from our files. The study group comprised 7 males and 8 females, ranging in age from 17 to 44 years (mean age, 32 years). The tumors involved the cervical (n = 11), thoracic (n = 1), lumbar (n = 2), and sacrococcygeal (n = 1) regions and ranged in size from 1.0 to 6.0 cm in greatest dimension (median size, 3 cm). Symptoms were present for 2 months to at least 2 years, with the most common complaint being pain localized to the spinal region (n = 12). Ten patients also had radicular symptoms. Radiologic studies, available for 11 cases, usually demonstrated a mass involving the posterior aspect of adjoining vertebrae. Bony abnormalities (including scalloping, erosion, and destruction), facet joint and soft tissue involvement, and extradural extension were typically present. Histologically, all tumors contained a proliferation of epithelioid (histiocytoid) cells, admixed with varying numbers of osteoclast-like giant cells, siderophages, xanthoma cells, lymphocytes, and some spindled fibroblast-like cells. Only 1 tumor had the classic villiform architecture of pigmented villonodular synovitis. The remaining 14 tumors had a nodular appearance with varying amounts of collagen. Seven of these had definite histological evidence of infiltrative growth, and 6 had some features that warranted concern for possible infiltration. Only 1 tumor had findings fully compatible with a localized synovial-type giant cell tumor/nodular (teno)synovitis. All tumors had mitotic activity, with mitotic counts ranging from 1 to 21 mitotic figures per 50 high-power fields (HPFs) (mean mitotic count, 5 mitotic figures/50 HPFs). Immunohistochemistry was performed on 5 tumors, and immunoreactivity was present for CD68, CD163, and vimentin. Limited immunoreactivity for muscle actin (HUC1-1) was also noted. Follow-up information was available for 9 of the 15 patients (60%). Five patients had no evidence of recurrent or persistent disease 4 months to 9 years after undergoing either a local excision with gross total tumor removal (with or without irradiation) or a wide en bloc resection. Four patients had persistent disease after undergoing either an incomplete resection or biopsy with spinal fusion procedure. All 4 of these patients had additional surgical intervention (accompanied by irradiation in 2 instances), but only one was known to be disease-free at last follow-up (10 years after gross total tumor removal). No patient has experienced a metastasis or died of disease. The best predictor of outcome was gross total tumor removal at the surgical outset.     

Repeated central administration of selegiline attenuated morphine physical dependence in rat

BackgroundLong-term exposure to opiates induces physical dependence; however, the neurobiological mechanisms of this phenomenon are not completely clear. The purpose of this study was to evaluate the effects of systemic and intracerebroventricular (icv) administration of selegiline (a selective inhibitor of monoamine oxidase B) on the morphine withdrawal syndrome in rats.MethodsTo this aim, adult male Sprague Dawley rats were selected randomly, and then growing doses of morphine were administered subcutaneously at an interval of 12 h for nine days with the intention of inducing dependency. Nine days after, only the morning dose of morphine was administered, followed by systemic or central injection of saline or selegiline. Later, naloxone was injected after 30 min and withdrawal signs recorded for a period of 60 min.ResultsResults showed failure of systemic administration of selegiline in changing the withdrawal symptoms; nevertheless, icv injection attenuated the withdrawal signs significantly.ConclusionIn conclusion we found that central administration of selegiline attenuated morphine withdrawal symptoms     

Unsteady-state airflow and particle deposition in a three-generation human lung geometry

The study of particle transport and deposition in the human lung is critical in health risk assessment of air pollutants and in pharmaceutical drug delivery. Several computational fluid dynamics (CFD) studies have investigated particle deposition in the lung for simplified airflow scenarios. A shortcoming with most CFD studies is uncertainty regarding flow boundary conditions, which directly impacts airflow and particle deposition. The influence of inlet and outlet conditions on airflow and particle deposition in lung common airways was assessed here. Common airways consisted of nine airways of the human lung ahead of lobes: the trachea, main, and lobar bronchi connected as a network of cylindrical tubes with dimensions based on morphometric measurements. Three different boundary conditions were used: (1) prescribed constant flow rate at the trachea entrance and atmospheric pressure at terminal branch exits, (2) atmospheric pressure at the trachea inlet and prescribed outlet flow rates corresponding to uniform lobar expansion, and (3) the same as case (2) with exit flow rates according to nonuniform lobar expansion. Unsteady airflow fields were numerically solved for a 2-s inhalation. Spherical particles of 1 nm to 10 microm diameter were injected at the trachea inlet, and particle deposition patterns during inhalation were evaluated. A Lagrangian particle tracking method was used that included particle inertia, gravity, and Brownian motion. Predicted flows showed similar trends but with a notable difference in magnitude. Lower particle deposition was found in case (1) for all particle sizes. The differences among these cases indicated the significance of realistic boundary conditions for accurate assessment of the flow field and particle deposition.     

Gemcitabine and interferon-alpha 2b in solid tumors: a phase I study in patients with advanced or metastatic non-small cell lung,ovarian, pancreatic or renal cancer

We performed a phase I study combining gemcitabine and interferon (IFN)- 2b in patients with advanced solid tumors to determine the maximum tolerated dose (MTD) and recommended doses for phase II trials. Five dose levels of gemcitabine (mg/m )/IFN- (x10 IU) were planned: 500/5, 1000/5, 1000/7, 1000/10 and 1200/10. Gemcitabine was given once weekly and IFN 3 x weekly for 3 consecutive weeks followed by 1 week of rest (28-day cycles). Between February 1997 and June 1999, 21 patients with advanced pancreatic ( =3), ovarian ( =1), renal ( =10) and non-small cell lung cancer (NSCLC; =7) were enrolled. The MTD was reached at gemcitabine 1000 mg/m and IFN- 7 x 10 IU, with two of three patients having dose-limiting toxicity (thrombocytopenia). The predominant hematologic toxicities (grade 3/4) were neutropenia and thrombocytopenia (13 and five patients, respectively). Three patients had moderate neutropenic fever and one had grade 4 AST/ALT; none required hospitalization. Of the 18 evaluable patients, responses included one partial response (NSCLC) and 10 stable diseases (eight renal cancer). We conclude that the recommended phase II study regimen is gemcitabine 1000 mg/m and IFN- 5 x 10 IU, every 28 days. The results, particularly those in metastatic renal carcinoma, are encouraging and worthy of further evaluation in phase II trials.     

Heparanase-1 expression is associated with the metastatic potential of breast cancer

BACKGROUND: Metastasis of malignant breast cells is in part mediated through degradation of the extra-cellular matrix by proteolysis, enabling malignant cells to migrate through the surrounding stroma. Heparanase-1 (HPR1) is an endoglycosidase that specifically degrades the heparan sulfate (HS) moiety of proteoglycans, a component of the extracellular matrix and basement membrane. METHODS: Fifty-one primary breast tumors, 13 lymph node metastases, 4 ductal carcinoma in situ, 7 benign, and 5 normal specimens were examined for HPR1 expression using immunohistochemical staining. The functional role of HPR1 expression was determined by examining HS deposition using immunofluorescence staining. RESULTS: Sixteen of 30 breast carcinomas (53%) with sentinel node metastasis expressed HPR1. In contrast, only 5 of 21 nonmetastatic primary breast carcinomas (23%) were HPR1 positive. Eighteen of 30 breast carcinomas between 1 and 5 cm expressed HPR1, compared with 3 of 21 HPR1-positive specimens in tumors < or =1 cm. Statistical analysis revealed that HPR1 expression was associated with breast tumor metastases (P =.04) and primary tumors between 1 and 5 cm (P =.002). Ninety percent of HPR1-positive tumors lacked HS deposition, suggesting an inverse correlation between HPR1 expression and HS deposition. CONCLUSIONS: HPR1 expression correlates with the lack of HS deposition and with the metastatic potential of breast cancers. The frequency of HPR1 is significantly higher in breast tumors between 1 and 5 cm than in tumors < or =1 cm.