Natural regeneration in exotic tree plantations in Hong Kong, China

Tree plantations consisting mostly of a single exotic species have been established in Hong Kong, South China, for reforesting degraded lands since the 1950s. In this study, natural woody plant regeneration success under different types of closed-canopy plantations (Acacia confusa, Lophostemon confertus, Melaleuca quinquenervia and mixed-plantings) and natural secondary forests in the central New Territories were assessed. A total of 79 tree species, 64 shrubs and 23 woody climbers were recorded in 16 20 m × 20 m plantation plots. Stem density of woody plant regeneration was similar among all sites, ranging from 9031 to 10,950 stems > 0.5 m in height per hectare. Multivariate analysis of understorey species composition showed that there were consistent differences between plantation types. Lophostemon plantations generally had poor native plant colonization in comparison with natural secondary forests and other types of plantations. These differences between forest types can be at least partly attributed to pre-existing site conditions, since the tree species planted were matched to the site. Native woody plant colonization was poor on sites isolated from natural seed sources. Plantation understories were generally dominated by a few species of bird-dispersed shrubs, suggesting that enrichment planting with poorly dispersed shade-tolerant native tree species will be needed to facilitate regeneration in those plantations where natural regeneration is inadequate. © 2005 Elsevier B.V. All rights reserved.postprin

Mortalin-p53 interaction in cancer cells is stress dependent and constitutes a novel target for liver cancer therapy

Poster AbstractsThis journal suppl. entitled: The International Liver Congress™ 2011 Abstract Book 46 annual meeting of the European Association for the Study of the LiverBACKGROUND AND AIMS: The mortality rate of HCC is high due to tumor recurrence and lack of effective treatment. By proteomics analysis of matched tumor and non-tumor tissues, mortalin was identified as a marker for hepatocellular carcinoma (HCC) metastasis and recurrence, suggesting its tight link in HCC development and recurrence. The aim of this study is to examine the role of mortalin in hepatocarcinogenesis. METHODS: The mortalin expression ...postprin

Personal and Network Dynamics in Performance of Knowledge Workers: A Study of Australian Breast Radiologists

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Hypercoagulability progresses to hypocoagulability during evolution of acetaminophen-induced acute liver injury in pigs

Increases in prothrombin time (PT) and international normalised ratio (INR) characterise acute liver injury (ALI) and failure (ALF), yet a wide heterogeneity in clotting abnormalities exists. This study defines evolution of coagulopathy in 10 pigs with acetaminophen (APAP)-induced ALI compared to 3 Controls. APAP administration began at 0 h and continued to ‘ALF’, defined as INR >3. In APAP pigs, INR was 1.05 ± 0.02 at 0 h, 2.15 ± 0.43 at 16 h and > 3 at 18 ± 1 h. At 12 h thromboelastography (TEG) demonstrated increased clot formation rate, associated with portal vein platelet aggregates and reductions in protein C, protein S, antithrombin and A Disintegrin and Metalloprotease with Thrombospondin type 1 repeats–13 (ADAMTS-13) to 60%, 24%, 47% and 32% normal respectively. At 18 ± 1 h, INR > 3 was associated with: hypocoagulable TEG profile with heparin-like effect; falls in thrombin generation, Factor V and Factor VIII to 52%, 19% and 17% normal respectively; further decline in anticoagulants; thrombocytopenia; neutrophilia and endotoxemia. Multivariate analysis, found that ADAMTS-13 was an independent predictor of a hypercoagulable TEG profile and platelet count, endotoxin, Protein C and fibrinogen were independent predictors of a hypocoagulable TEG profile. INR remained normal in Controls. Dynamic changes in coagulation occur with progression of ALI: a pro-thrombotic state progresses to hypocoagulability

Audiovisual Biofeedback Improves Cine-Magnetic Resonance Imaging Measured Lung Tumor Motion Consistency.

PURPOSE: To assess the impact of an audiovisual (AV) biofeedback on intra- and interfraction tumor motion for lung cancer patients. METHODS AND MATERIALS: Lung tumor motion was investigated in 9 lung cancer patients who underwent a breathing training session with AV biofeedback before 2 3T magnetic resonance imaging (MRI) sessions. The breathing training session was performed to allow patients to become familiar with AV biofeedback, which uses a guiding wave customized for each patient according to a reference breathing pattern. In the first MRI session (pretreatment), 2-dimensional cine-MR images with (1) free breathing (FB) and (2) AV biofeedback were obtained, and the second MRI session was repeated within 3-6 weeks (mid-treatment). Lung tumors were directly measured from cine-MR images using an auto-segmentation technique; the centroid and outlier motions of the lung tumors were measured from the segmented tumors. Free breathing and AV biofeedback were compared using several metrics: intra- and interfraction tumor motion consistency in displacement and period, and the outlier motion ratio. RESULTS: Compared with FB, AV biofeedback improved intrafraction tumor motion consistency by 34% in displacement (P=.019) and by 73% in period (P<.001). Compared with FB, AV biofeedback improved interfraction tumor motion consistency by 42% in displacement (P<.046) and by 74% in period (P=.005). Compared with FB, AV biofeedback reduced the outlier motion ratio by 21% (P<.001). CONCLUSIONS: These results demonstrated that AV biofeedback significantly improved intra- and interfraction lung tumor motion consistency for lung cancer patients. These results demonstrate that AV biofeedback can facilitate consistent tumor motion, which is advantageous toward achieving more accurate medical imaging and radiation therapy procedures

The influence of perfusion solution on renal graft viability assessment

BACKGROUND: Kidneys from donors after cardiac or circulatory death are exposed to extended periods of both warm ischemia and intra-arterial cooling before organ recovery. Marshall’s hypertonic citrate (HOC) and Bretschneider’s histidine-tryptophan-ketoglutarate (HTK) preservation solutions are cheap, low viscosity preservation solutions used clinically for organ flushing. The aim of the present study was to evaluate the effects of these two solutions both on parameters used in clinical practice to assess organ viability prior to transplantation and histological evidence of ischemic injury after reperfusion. METHODS: Rodent kidneys were exposed to post-mortem warm ischemia, extended intra-arterial cooling (IAC) (up to 2 h) with preservation solution and reperfusion with either Krebs-Hensleit or whole blood in a transplant model. Control kidneys were either reperfused directly after retrieval or stored in 0.9% saline. Biochemical, immunological and histological parameters were assessed using glutathione-S-transferase (GST) enzymatic assays, polymerase chain reaction and mitochondrial electron microscopy respectively. Vascular function was assessed by supplementing the Krebs-Hensleit perfusion solution with phenylephrine to stimulate smooth muscle contraction followed by acetylcholine to trigger endothelial dependent relaxation. RESULTS: When compared with kidneys reperfused directly post mortem, 2 h of IAC significantly reduced smooth muscle contractile function, endothelial function and upregulated vascular cellular adhesion molecule type 1 (VCAM-1) independent of the preservation solution. However, GST release, vascular resistance, weight gain and histological mitochondrial injury were dependent on the preservation solution used. CONCLUSIONS: We conclude that initial machine perfusion viability tests, including ischemic vascular resistance and GST, are dependent on the perfusion solution used during in situ cooling. HTK-perfused kidneys will be heavier, have higher GST readings and yet reduced mitochondrial ischemic injury when compared with HOC-perfused kidneys. Clinicians should be aware of this when deciding which kidneys to transplant or discard