Release and accumulation of neurotransmitters in the rat brain: acute effects of ethanol in vitro and effects of long-term voluntary ethanol intake

OBJECTIVE: The purpose of this study is to examine the accuracy and complications of transthoracic needle aspiration biopsy (TTNA) to determine its optimal role in the evaluation of patients with lung tumors. MATERIALS AND METHODS: The charts of 130 consecutive patients who had undergone CT-guided TTNA were reviewed retrospectively. Thirty-two (25%) of these patients had subsequent surgery and 5 had subsequent transbronchial biopsy (TBB). Using the final surgical and TBB diagnosis as a reference, the accuracy, sensitivity, specificity, and prevalence of malignancy were calculated. Each case was also examined to determine the presence or absence of complications. RESULTS: Of the 130 biopsy results, 95 (73%) were malignant, 33 (25%) were nonspecific, and only 2 (2%) had a specific benign diagnosis. Thirty-two patients subsequently underwent surgical resection. The overall prevalence of malignancy after surgical diagnosis was 91%. The overall diagnostic accuracy of TTNA was 76%. The sensitivity of TTNA for the detection of malignancy was 74% and its specificity was 100%. When comparing TTNA results of small (<3 cm) and large (> or = 3 cm) tumors, the occurrence of nonspecific results was 36% and 16%, respectively. Fifty-six (43%) patients had a pneumothorax subsequent to TTNA. Twenty-four (43%) of these patients required a chest tube and remained hospitalized for a mean of 6 days. CONCLUSION: Patients who are surgical candidates and have a high clinical suspicion for malignancy should undergo surgical biopsy and resection of their lung tumors if indicated. Information gained from TTNAs performed on this patient population will rarely result in a change in their clinical management.     

Electron-beam computed tomography in heart surgery

PURPOSE: Electron beam CT (EBCT) has been devised to improve the imaging of the heart and the great vessels. Therefore, this method is expected to facilitate the imaging workup of patients referred for cardiothoracic surgery. We set out to review the most important surgical issues that can be addressed with this method. METHODS: From June, 1997 until July, 1998, more than 300 patients were referred from cardiothoracic surgery. In a retrospective analysis, diagnostic results were reviewed and compared with surgical findings and the clinical course. RESULTS: Aortocoronary bypass graft occlusions were detected with a sensitivity of 100% and a specificity of 95%. Calcifications of the aorta, pericardium and intracardiac tumors were surgically confirmed in all instances. There was a significant association of the degree of coronary artery calcification and the progression of cardiac allograft vasculopathy in 50 heart transplant recipients. In EBCT of the aorta, a high degree of diagnostic confidence was found for aortic dissection, aortic wall hematoma or aortic perforation. CONCLUSIONS: We conclude that EBCT represents an important diagnostic tool both for surgical planning and postoperative surveillance in cardiothoracic surgery.     

A heterologous in vitro coculture system to study interaction between human bladder cancer cells and fibroblasts

Three-dimensional multicellular spheroids of two fibroblast cell lines (WI-38 and N1) and two differently differentiated bladder carcinoma cell lines (RT4 and J82) were used for cocultures of multicellular tumor spheroids with multicellular spheroids of fibroblasts. The aim of the study was the establishment and characterization of a standardized three-dimensional model for studies of tumor cell-fibroblast interaction as one aspect of tumor-stromal cell interactions of in vivo tumor tissue. Interaction of multicellular spheroids of both fibroblast cell types was analyzed by staining with antibodies against cytokeratin, vimentin and different extracellular matrix molecules. Further, proliferation assessment and phenotypic characterization of the cocultures are presented. Interactions varied with tumor cell type and fibroblast cell type, reflecting intrinsic properties of tumor cells and fibroblasts. The coculture of tumor cells with N1 reflected the in vivo situation the closest, since invasive properties of J82 as well as noninvasive properties of RT4 were characteristics seen in coculture.     

Heat transfer in liquid hydrogen

With boiling of hydrogen under pressure one observes a shift of the q-ΔT curves to higher values of ΔT, caused by a layer of solidified gases, the thickness of which increases continuously. With this process one observes ‘hysteresis’.The departure diameter D and the frequency f of bubbles were observed with discrete nucleate boiling under pressure. The results can be described by the equation f D² = K; K diminishes with rising pressure and with increasing roughness of the surface.     

Low energy ion scattering study of Ni-MoAl2O3 catalysts

The principles of low energy ion scattering (ISS) and its application to the study of real catalyst surfaces are discussed. As a special example, the effect of the calcination temperature of a Ni-Mo/ Al₂O₃ on the elemental distribution is studied. From the ISS “depth profiles” it can be concluded that at temperatures <770 K the molybdate phase on the Al₂O₃ support forms islands with three-dimensional extension while uncovered support surface remains even though the loading corresponds to the theoretical monolayer capacity. A spreading of the molybdate over the support surface occurs at 870 K to form a more or less closed monolayer. Simultaneously, Ni²⁺ ions are lost from the surface molybdate by penetration into subsurface layers of the Al₂O₃ matrix where they occupy octahedral and tetrahedral sites. The importance of the redistribution of promotor ions and the dispersion of the molybdate phase for the catalytic performance is emphasized.     

Correlation of in vitro and in vivo results of vacuum plasma sprayed titanium implants with different surface topography

Research has proven that rough surfaces improve both biologic and biomechanical responses to titanium (Ti) implants. The purpose of this study was to evaluate the correlation between the expression of bone cell-associated proteins to Vacuum Plasma-Sprayed Titanium implants (VPS-Ti) with different surface textures in vitro and the bone integration in vivo. The biological performances of the surfaces were evaluated over a period of 8 weeks using human bone marrow cell cultures and Göttinger mini pigs. Cells were cultured on VPS-Ti with two respectively different surface-roughnesses (Ra). The level of Osteoprotegerin (OPG), Osteocalcin (OC) and alkaline phosphatase activity (ALP) were evaluated. The bone integration in vivo was evaluated by histomorphological analyses. A cancellous structured titanium (CS-Ti) construct was used as reference material in both study designs. Comparison of data was conducted using the Scheffé tests and the paired t-test with Bonferroni’s correction. A comparative analysis was done to measure the degree of association between the in vitro and in vivo data. A total amount of OC was significantly increased for VPS-Ti for cells cultured on both VPS-Ti and CS-Ti, while OPG was only detectable after 8 weeks without any significant differences. The ALP activity on all surfaces was not statistically increased. For VPS-Ti with Ra ranging from 0.025 mm up to 0.059 mm, bone integration response was increased, but there was no statistical difference between the VPS-Ti. Expression of OPG, OC and ALP correlated with the histomorphological data over the 8-week period. The in vitro data suggest the superiority of VPS-Ti over CS-Ti, but more importantly, the biocompatibility of testing an in vitro model to predict the outcome and possible integration of implants in vivo.