P53 intron 2 polymorphisms and mutations in non-small cell lung carcinoma in Hong Kong

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Endothelial Cells in Co-culture Enhance Embryonic Stem Cell Differentiation to Pancreatic Progenitors and Insulin-Producing Cells through BMP Signaling

Endothelial cells (ECs) represent the major component of the embryonic pancreatic niche and play a key role in the differentiation of insulin-producing β cells in vivo. However, it is unknown if ECs promote such differentiation in vitro. We investigated whether interaction of ECs with mouse embryoid bodies (EBs) in culture promotes differentiation of pancreatic progenitors and insulin-producing cells and the mechanisms involved. We developed a co-culture system of mouse EBs and human microvascular ECs (HMECs). An increase in the expression of the pancreatic markers PDX-1, Ngn3, Nkx6.1, proinsulin, GLUT-2, and Ptf1a was observed at the interface between EBs and ECs (EB-EC). No expression of these markers was found at the periphery of EBs cultured without ECs or those co-cultured with mouse embryonic fibroblasts (MEFs). At EB-EC interface, proinsulin and Nkx6.1 positive cells co-expressed phospho-Smad1/5/8 (pSmad1/5/8). Therefore, EBs were treated with HMEC conditioned media (HMEC-CM) suspecting soluble factors involved in bone morphogenetic protein (BMP) pathway activation. Upregulation of PDX-1, Ngn3, Nkx6.1, insulin-1, insulin-2, amylin, SUR1, GKS, and amylase as well as down-regulation of SST were detected in treated EBs. In addition, higher expression of BMP-2/-4 and their receptor (BMPR1A) were also found in these EBs. Recombinant human BMP-2 (rhBMP-2) mimicked the effects of the HMEC-CM on EBs. Noggin (NOG), a BMP antagonist, partially inhibited these effects. These results indicate that the differentiation of EBs to pancreatic progenitors and insulin-producing cells can be enhanced by ECs in vitro and that BMP pathway activation is central to this process

Elevated plasma adiponectin levels in patients with chronic obstructive pulmonary disease

BACKGROUND: Adiponectin is an anti-inflammatory adipokine that may play a role in chronic obstructive pulmonary disease (COPD) pathogenesis. OBJECTIVE: To investigate the relationship between adiponectin, interleukin (IL) 6, IL-8 and C-reactive protein (CRP) and COPD by evaluating these biomarkers in ever-smokers with or without the disease. METHOD: Plasma levels of adiponectin, IL-6, IL-8 and CRP were measured using commercially available kits in COPD patients (n = 71), healthy ever-smokers (n = 62) and non-smokers (n = 51). RESULTS: There were significant increases in plasma adiponectin, IL-6 and CRP in COPD patients (median [IQR] 4.39 μg/ml [2.68-6.98], 4.19 pg/ml [<2.40-6.40], 8.75 mg/l [4.26-40.63], respectively) compared to healthy ever-smokers (1.90 μg/ml [0.86-2.86], <2.40 pg/ml [<2.40-2.77], 3.71 mg/l [1.97-10.37 mg/l], respectively, P < 0.001) and non-smokers (1.76 μg/ml [1.34-2.52], <2.40 pg/ml [<2.40-2.78], 3.12 mg/l [2.11-5.71], respectively, P < 0.001). COPD patients had lower plasma IL-8 levels than healthy ever-smokers. Among ever-smokers with or without COPD, plasma adiponectin, IL-6 and CRP levels were inversely correlated with forced expiratory volume in 1 second (% predicted) after adjustment for age, body mass index, smoking status and pack-years. CONCLUSION: Our findings suggest that in COPD patients, adiponectin might be associated with COPD pathogenesis. © 2010 The Union.postprin

A New Model of Delirium Care in the Acute Geriatric Setting: Geriatric Monitoring Unit

<p>Abstract</p> <p>Background</p> <p>Delirium is a common and serious condition, which affects many of our older hospitalised patients. It is an indicator of severe underlying illness and requires early diagnosis and prompt treatment, associated with poor survival, functional outcomes with increased risk of institutionalisation following the delirium episode in the acute care setting. We describe a new model of delirium care in the acute care setting, titled Geriatric Monitoring Unit (GMU) where the important concepts of delirium prevention and management are integrated. We hypothesize that patients with delirium admitted to the GMU would have better clinical outcomes with less need for physical and psychotropic restraints compared to usual care.</p> <p>Methods/Design</p> <p>GMU models after the Delirium Room with adoption of core interventions from Hospital Elder Life Program and use of evening bright light therapy to consolidate circadian rhythm and improve sleep in the elderly patients. The novelty of this approach lies in the amalgamation of these interventions in a multi-faceted approach in acute delirium management. GMU development thus consists of key considerations for room design and resource planning, program specific interventions and daily core interventions. Assessments undertaken include baseline demographics, comorbidity scoring, duration and severity of delirium, cognitive, functional measures at baseline, 6 months and 12 months later. Additionally we also analysed the pre and post-GMU implementation knowledge and attitude on delirium care among staff members in the geriatric wards (nurses, doctors) and undertook satisfaction surveys for caregivers of patients treated in GMU.</p> <p>Discussion</p> <p>This study protocol describes the conceptualization and implementation of a specialized unit for delirium management. We hypothesize that such a model of care will not only result in better clinical outcomes for the elderly patient with delirium compared to usual geriatric care, but also improved staff knowledge and satisfaction. The model may then be transposed across various locations and disciplines in the acute hospital where delirious patients could be sited.</p> <p>Trial Registration</p> <p>Current Controlled Trials <a href="http://www.controlled-trials.com/ISRCTN52323811">ISRCTN52323811</a></p

Interaction of TGFβ and BMP Signaling Pathways during Chondrogenesis

TGFβ and BMP signaling pathways exhibit antagonistic activities during the development of many tissues. Although the crosstalk between BMP and TGFβ signaling pathways is well established in bone development, the relationship between these two pathways is less well defined during cartilage development and postnatal homeostasis. We generated hypomorphic mouse models of cartilage-specific loss of BMP and TGFβ signaling to assess the interaction of these pathways in postnatal growth plate homeostasis. We further used the chondrogenic ATDC5 cell line to test effects of BMP and TGFβ signaling on each other's downstream targets. We found that conditional deletion of Smad1 in chondrocytes resulted in a shortening of the growth plate. The addition of Smad5 haploinsufficiency led to a more severe phenotype with shorter prehypertrophic and hypertrophic zones and decreased chondrocyte proliferation. The opposite growth plate phenotype was observed in a transgenic mouse model of decreased chondrocytic TGFβ signaling that was generated by expressing a dominant negative form of the TGFβ receptor I (ΔTβRI) in cartilage. Histological analysis demonstrated elongated growth plates with enhanced Ihh expression, as well as an increased proliferation rate with altered production of extracellular matrix components. In contrast, in chondrogenic ATDC5 cells, TGFβ was able to enhance BMP signaling, while BMP2 significantly reduces levels of TGF signaling. In summary, our data demonstrate that during endochondral ossification, BMP and TGFβ signaling can have antagonistic effects on chondrocyte proliferation and differentiation in vivo. We also found evidence of direct interaction between the two signaling pathways in a cell model of chondrogenesis in vitro

Endothelium-Derived Netrin-4 Supports Pancreatic Epithelial Cell Adhesion and Differentiation through Integrins α2β1 and α3β1

BACKGROUND: Netrins have been extensively studied in the developing central nervous system as pathfinding guidance cues, and more recently in non-neural tissues where they mediate cell adhesion, migration and differentiation. Netrin-4, a distant relative of Netrins 1-3, has been proposed to affect cell fate determination in developing epithelia, though receptors mediating these functions have yet to be identified. METHODOLOGY/PRINCIPAL FINDINGS: Using human embryonic pancreatic cells as a model of developing epithelium, here we report that Netrin-4 is abundantly expressed in vascular endothelial cells and pancreatic ductal cells, and supports epithelial cell adhesion through integrins α2β1 and α3β1. Interestingly, we find that Netrin-4 recognition by embryonic pancreatic cells through integrins α2β1 and α3β1 promotes insulin and glucagon gene expression. In addition, full genome microarray analysis revealed that fetal pancreatic cell adhesion to Netrin-4 causes a prominent down-regulation of cyclins and up-regulation of negative regulators of the cell cycle. Consistent with these results, a number of other genes whose activities have been linked to developmental decisions and/or cellular differentiation are up-regulated. CONCLUSIONS/SIGNIFICANCE: Given the recognized function of blood vessels in epithelial tissue morphogenesis, our results provide a mechanism by which endothelial-derived Netrin-4 may function as a pro-differentiation cue for adjacent developing pancreatic cell populations expressing adhesion receptors α2β1 and α3β1 integrins

Polymorphisms and mutatons detected in P53 exon 2 and intron 2 in lung carcinomas in Hong Kong

Purpose: Lung cancer is the commonest cause of cancer death in both men and women in Hong Kong, and over 60% of our female patients are non-smokers. Gene mutations are involved in the multistage process of lung tumorigenesis. p53 gene mutations with ethnic differences have been reported. In our previous study of 52 non-small cell lung carcinoma (NSCLC) patients, a polymorphism in p53 intron 2 (A1 and A2 alleles) and a 15% frequency of p53 intron 2 mutations were detected. In the present study, the significance of these polymorphisms and mutations was further studied. Methods: Triple specimens from the lung tumour, normal lung tissue and peripheral blood of 23 NSCLC patients were analysed for polymorphisms and mutations in p53 gene intron 2 and exons 2 and 3 by polymerase chain reaction - single strand conformation polymorphism and direct DNA-sequencing techniques. Results: All cell lines established from peripheral blood lymphocytes shared the same genotypes found in the normal lung tissue, but differed in 4 cases where mutations were detected in the tumours. Detected mutations in the tumour tissues resulted from an A2 to A1 conversion. The A1 allelic frequency appeared to be specifically and significantly increased in the adenocarcinoma tumour tissues as compared to normal tissues in these patients. A new polymorphism localized to p53 exon 2 was detected, appearing with equally high frequency among lung cancer patients and healthy individuals. Conclusions: The p53 intron 2 polymorphic locus is a hot spot for mutations in Hong Kong lung cancer patients and these mutations are probably somatic. Clinical Implications: p53 gene is a commonly affected target gene in our NSCLC patients, and intron 2 mutations may play a role in the malfunction of p53 gene during lung carcinogenesis in Chinese patients in Hong Kong. Peripheral blood DNA may be used to analyse the normal genotype of this locus. The clinical significance of the new p53 polymorphism in exon 2 remains to be elucidated.link_to_OA_fulltex

p53 intron 2 genotypes detected in normal specimens and lung carcinomas in Hong Kong

Previous studies suggest that the polymorphic p53 intron 2 displays a high frequency of mutations, occurring with different frequencies in tumor tissues versus peripheral blood of lung cancer patients as compared to healthy individuals. We evaluated the significance of these polymorphisms and mutations utilizing matched triple specimens from the lung tumor, normal lung tissue, and peripheral blood of cancer patients. Identical genotypes were observed in normal tissues and blood, while 4 mutations were observed in tumors. The Al allelic frequency was increased in the adenocarcinoma tissues as compared to normal tissues. Two p53 exon 2 polymorphisms were detected, appearing with equal frequencies among cancer patients and healthy individuals. The p53 intron 2 polymorphic locus is a hot spot for mutations in Hong Kong lung cancer patients