625 research outputs found
Combined simultaneous transcranial and transsphenoidal resection of large-to-giant pituitary adenomas
Background: While large-to-giant pituitary adenomas (PAs) may be safely removed by experienced surgeons through a single route, the procedure is technically challenging. We present the outcome of a simultaneous combined transcranial and transsphenoidal approach and discuss its applications. Methods: A retrospective review was conducted on 12 consecutive patients. Surgical complications, visual and endocrinological functions, and tumour control were reviewed. Results: There were four men and eight women, with a mean age of 47.6 years. All but one patient had non-functioning PAs. The mean tumour height was 4.1 cm (range: 2.3-5.5). The predominant presenting symptoms were visual field loss in eight patients, headache in three patients and mental confusion in one patient. There was no operative mortality. Post-operative cerebrospinal fluid leakage occurred in one patient. Five of the eight patients who presented with visual field loss achieved full recovery, and three had partial improvement. Two patients developed permanent diabetes insipidus after surgery. Panhypopituitarism occurred in one patient. Gross total removal (GTR) was achieved in five, and subtotal removal (STR) in seven patients. Seven patients received post-operative external irradiation. All patients who had GTR remained tumour-free and all those with STR had stable diseases after a mean follow-up period of 53.1 months (range: 14.1-92.1). Conclusion: The simultaneous 'above and below' approach is a safe and effective surgical strategy for large-to-giant PAs, particularly when expertise in endoscopic transsphenoidal surgery is unavailable. Its use, however, should be limited to a carefully selected group of patients, and tailored to individual user's expertise and experience. © 2011 The Author(s).published_or_final_versio
Structural change and the narrowing gender gap in wages : theory and evidence from Hong Kong
This paper offers a theoretical and empirical analysis on the sources of the narrowing gender gap in wages. Based on some existing literature, the model posits that the narrowing gender gap may be related to women\u27s changing comparative advantage and the gender gap is smaller in occupations in which physical labor is less intensively used. The model implies that when an economy transforms from a manufacturing-oriented economy to service-oriented economy, a woman\u27s productivity relative to a man\u27s will generally increase so that the gender gap narrows. The implications of the theoretica1 analysis are then tested based on one percent random sub-samples of two population censuses. The empirical results support the predictions of the model
Neuroprotective effects of ginsenosides Rh1 and Rg2 on neuronal cells
<p>Abstract</p> <p>Background</p> <p>The present study investigates the effects of ginsenosides Rh<sub>1 </sub>and Rg<sub>2 </sub>against 6-hydroxydopamine (6-OHDA), a neurotoxin on SH-SY5Y cells and PC-12 cells. The effects of these two ginsenosides on neuronal differentiation are also examined.</p> <p>Methods</p> <p>LDH assay was used to measure cell viability after exposure to 6-OHDA and ginsenosides. Neuronal differentiation was evaluated by changes in cell morphology and density of neurite outgrowths. Western blotting was used to determine the ginsenosides' effects on activation of extracellular signal-regulated protein kinases (ERKs).</p> <p>Results</p> <p>Rh<sub>1 </sub>and Rg<sub>2 </sub>attenuated 6-OHDA toxicity in SH-SY5Y cells and induced neurite outgrowths in PC-12 cells. 6-OHDA-induced ERK phosphorylation was decreased by Rh<sub>1 </sub>and Rg<sub>2</sub>. 20(R)-form and 20(S)-form of the ginsenosides exerted similar effects in inducing neurite outgrowths in PC-12 cells.</p> <p>Conclusion</p> <p>The present study demonstrates neuroprotective effects of ginsenosides Rh<sub>1 </sub>and Rg<sub>2 </sub>on neuronal cell lines. These results suggest potential Chinese medicine treatment for neurodegenerative disorders (<it>eg </it>Parkinson's disease).</p
Right ventricular exclusion for hepatocellular carcinoma metastatic to the heart
We used for the first time a right ventricular exclusion procedure for the treatment of hepatocellular carcinoma metastatic to the right ventricle. Our case report shows that this surgical option can be effective as rescue therapy for right ventricular outflow tract obstruction secondary to myocardial metastasis in critically ill patients. Most notably, this technique can prevent inadvertent dislodgement of tumor cells
Granulin-epithelin precursor is an oncofetal protein defining hepatic cancer stem cells
Background and Aims: Increasing evidence has suggested that hepatocellular carcinoma (HCC) might originate from a distinct subpopulation called cancer stem cells (CSCs), which are responsible for the limited efficacy of conventional therapies. We have previously demonstrated that granulin-epithelin precursor (GEP), a pluripotent growth factor, is upregulated in HCC but not in the adjacent non-tumor, and that GEP is a potential therapeutic target for HCC. Here, we characterized its expression pattern and stem cell properties in fetal and cancerous livers. Methods: Protein expression of GEP in fetal and adult livers was examined in human and mouse models by immunohistochemical staining and flow cytometry. Liver cancer cell lines, isolated based on their GEP and/or ATP-dependent binding cassette (ABC) drug transporter ABCB5 expression, were evaluated for hepatic CSC properties in terms of colony formation, chemoresistance and tumorigenicity. Results: We demonstrated that GEP was a hepatic oncofetal protein that expressed in the fetal livers, but not in the normal adult livers. Importantly, GEP+ fetal liver cells co-expressed the embryonic stem (ES) cell-related signaling molecules including β-catenin, Oct4, Nanog, Sox2 and DLK1, and also hepatic CSC-markers CD133, EpCAM and ABCB5. Phenotypic characterization in HCC clinical specimens and cell lines revealed that GEP+ cancer cells co-expressed these stem cell markers similarly as the GEP+ fetal liver cells. Furthermore, GEP was shown to regulate the expression of ES cell-related signaling molecules β-catenin, Oct4, Nanog, and Sox2. Isolated GEP high cancer cells showed enhanced colony formation ability and chemoresistance when compared with the GEP low counterparts. Co-expression of GEP and ABCB5 better defined the CSC populations with enhanced tumorigenic ability in immunocompromised mice. Conclusions: Our findings demonstrate that GEP is a hepatic oncofetal protein regulating ES cell-related signaling molecules. Co-expression of GEP and ABCB5 further enriches a subpopulation with enhanced CSC properties. The current data provide new insight into the therapeutic strategy. © 2011 Cheung et al.published_or_final_versio
How do tree species with different successional stages affect soil organic nitrogen transformations?
Organic nitrogen (N) is the most important N component of soil organic matter.However, knowledge on how tree species with different successional stages affect its transformations in soils remains limited. To address this issue, we sampled mineral soils (0−10 cm) in monocultures composed by tree species of different successional stages, including early (black alder and silver birch), early to mid (sycamore and European ash), and late (sweet chestnut, pedunculate oak and European beech), and measured the potential protease activity, the microbial uptake and respiration of 14C-labeled organic N (L-alanine and L-trialanine), and the mineralization of L-alanine N. The activities of alanine aminopeptidase and leucine aminopeptidase (153.8−341.9 and 91.6−147.9 nmol/g/h, respectively), the half-life of the uptake of alanine and trialanine (26.7−39.6 and 60.8−78.6 min, respectively), the half-life of the mineraliztion of alanine and trialanine (1.98−2.45 and 2.98−4.13 h, respectively) by soil microbes were altered by tree species of different successional stages, systematically changing the transformation chain of soil organic N. From trees of early successional stage to that of late, the turnover rates of soil organic N appeared to decrease and the half-life appeared to increase significantly. The (carbon) C:N ratio of soil microbial biomass was positively related to the half-life of 14Clabeled alanine and trialanine mineralization, and was negatively related to the C use efficiency of alanine, suggesting that microbial demand for C could partially drive the assimilation of soil organic N. Our results suggest that the successional stage of tree species play an important role in regulating the soil organic N turnover. An improved understanding of how tree species with different successional stages influence microbial function and soil organic N cycling is beneficial to future afforestation and forest management, alleviating the impacts of global change on the ecosystem
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