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1.
Hong Kong Med J ; 29(1): 49-56, 2023 02.
Article in English | MEDLINE | ID: mdl-36810240

ABSTRACT

INTRODUCTION: This post-hoc analysis retrospectively assessed data from two recent studies of antiemetic regimens for chemotherapy-induced nausea and vomiting (CINV). The primary objective was to compare olanzapine-based versus netupitant/palonosetron (NEPA)-based regimens in terms of controlling CINV during cycle 1 of doxorubicin/cyclophosphamide (AC) chemotherapy; secondary objectives were to assess quality of life (QOL) and emesis outcomes over four cycles of AC. METHODS: This study included 120 Chinese patients with early-stage breast cancer who were receiving AC; 60 patients received the olanzapine-based antiemetic regimen, whereas 60 patients received the NEPA-based antiemetic regimen. The olanzapine-based regimen comprised aprepitant, ondansetron, dexamethasone, and olanzapine; the NEPA-based regimen comprised NEPA and dexamethasone. Patient outcomes were compared in terms of emesis control and QOL. RESULTS: During cycle 1 of AC, the olanzapine group exhibited a higher rate of 'no use of rescue therapy' in the acute phase (olanzapine vs NEPA: 96.7% vs 85.0%, P=0.0225). No parameters differed between groups in the delayed phase. The olanzapine group had significantly higher rates of 'no use of rescue therapy' (91.7% vs 76.7%, P=0.0244) and 'no significant nausea' (91.7% vs 78.3%, P=0.0408) in the overall phase. There were no differences in QOL between groups. Multiple cycle assessment revealed that the NEPA group had higher rates of total control in the acute phase (cycles 2 and 4) and the overall phase (cycles 3 and 4). CONCLUSION: These results do not conclusively support the superiority of either regimen for patients with breast cancer who are receiving AC.


Subject(s)
Antiemetics , Antineoplastic Agents , Breast Neoplasms , Humans , Female , Antiemetics/adverse effects , Palonosetron/adverse effects , Olanzapine/adverse effects , Quality of Life , Retrospective Studies , Dexamethasone , Vomiting , Nausea , Breast Neoplasms/drug therapy , Antineoplastic Agents/adverse effects
2.
Front Surg ; 9: 956177, 2022.
Article in English | MEDLINE | ID: mdl-36090334

ABSTRACT

During bypass surgery for peripheral arterial occlusive disease and ischaemic heart disease, autologous graft conduit including great saphenous veins and radial arteries are frequently stored in solution. Endothelial damage adversely affects the performance and patency of autologous bypass grafts, and intraoperative graft storage solutions have been shown to influence this process. The distribution of storage solutions currently used amongst Cardiothoracic and Vascular Surgeons from Australia and New Zealand is not well defined in the literature. The aim of this study was to determine current practices regarding autologous graft storage and handling amongst this cohort of surgeons, and discuss their potential relevance in the context of early graft failure. From this survey, the most frequently used storage solutions were heparinized saline for great saphenous veins, and pH-buffered solutions for radial arteries. Duration of storage was 30-45 min for almost half of respondents, although responses to this question were limited. Further research is required to investigate whether ischaemic endothelial injury generates a prothrombotic state, whether different storage media can alter this state, and whether this is directly associated with clinical outcomes of interest such as early graft failure.

3.
Hong Kong Med J ; 28(3): 230-238, 2022 06.
Article in English | MEDLINE | ID: mdl-35667869

ABSTRACT

BACKGROUND: Neoadjuvant chemoradiotherapy is a standard treatment for locally advanced rectal cancer, for which pathological complete response is typically used as a surrogate survival endpoint. Neoadjuvant rectal score is a new biomarker that has been shown to correlate with survival. The main objectives of this study were to investigate factors contributing to pathological complete response, to validate the prognostic significance of neoadjuvant rectal score, and to investigate factors associated with a lower neoadjuvant rectal score in a cohort of Hong Kong Chinese. METHODS: Data of patients with locally advanced rectal cancer who received neoadjuvant chemoradiotherapy from August 2006 to October 2018 were retrieved from hospital records and retrospectively analysed. RESULTS: Of 193 patients who had optimal response to neoadjuvant chemoradiotherapy and surgery, tumour down-staging was the only independent prognostic factor that predicted pathological complete response (P<0.0001). Neoadjuvant rectal score was associated with overall survival (hazard ratio [HR]=1.042, 95% confidence interval [CI]=1.021-1.064; P<0.0001), disease-free survival (HR=1.042, 95% CI=1.022-1.062; P<0.0001), locoregional recurrence-free survival (HR=1.070, 95% CI=1.039-1.102; P<0.0001) and distant recurrence-free survival (HR=1.034, 95% CI=1.012-1.056; P=0.002). Patients who had pathological complete response were associated with a lower neoadjuvant rectal score (P<0.0001), but pathological complete response was not associated with survival. For patients with intermediate neoadjuvant rectal scores, late recurrences beyond 72 months from diagnosis were observed. CONCLUSION: Neoadjuvant rectal score is an independent prognostic marker of survival and disease recurrence in a cohort of Hong Kong Chinese patients who received neoadjuvant chemoradiotherapy for locally advanced rectal cancer.


Subject(s)
Neoadjuvant Therapy , Rectal Neoplasms , Biomarkers , Chemoradiotherapy , Disease-Free Survival , Hong Kong , Humans , Neoplasm Recurrence, Local/pathology , Neoplasm Staging , Prognosis , Rectal Neoplasms/pathology , Rectal Neoplasms/therapy , Retrospective Studies , Treatment Outcome
4.
J Urban Health ; 99(1): 28-54, 2022 02.
Article in English | MEDLINE | ID: mdl-34997433

ABSTRACT

We reviewed research that examines racism as an independent variable and one or more health outcomes as dependent variables in Black American adults aged 50 years and older in the USA. Of the 43 studies we reviewed, most measured perceived interpersonal racism, perceived institutional racism, or residential segregation. The only two measures of structural racism were birth and residence in a "Jim Crow state." Fourteen studies found associations between racism and mental health outcomes, five with cardiovascular outcomes, seven with cognition, two with physical function, two with telomere length, and five with general health/other health outcomes. Ten studies found no significant associations in older Black adults. All but six of the studies were cross-sectional. Research to understand the extent of structural and multilevel racism as a social determinant of health and the impact on older adults specifically is needed. Improved measurement tools could help address this gap in science.


Subject(s)
Racism , Social Segregation , Black or African American/psychology , Aged , Black People , Humans , Middle Aged , Racism/psychology , Systemic Racism
5.
Biomed J ; 45(5): 776-787, 2022 Oct.
Article in English | MEDLINE | ID: mdl-34666219

ABSTRACT

INTRODUCTION: Organs procured following brain stem death (BSD) are the main source of organ grafts for transplantation. However, BSD is associated with inflammatory responses that may damage the organ and affect both the quantity and quality of organs available for transplant. Therefore, we aimed to investigate plasma and bronchoalveolar lavage (BAL) pro-inflammatory cytokine profiles and cardiovascular physiology in a clinically relevant 6-h ovine model of BSD. METHODS: Twelve healthy female sheep (37-42 Kg) were anaesthetized and mechanically ventilated prior to undergoing BSD induction and then monitored for 6 h. Plasma and BAL endothelin-1 and cytokines (IL-1ß, 6, 8 and tumour necrosis factor alpha (TNF-α)) were assessed by ELISA. Differential white blood cell counts were performed. Cardiac function during BSD was also examined using echocardiography, and cardiac biomarkers (A-type natriuretic peptide and troponin I were measured in plasma. RESULTS: Plasma concentrations big ET-1, IL-6, IL-8, TNF-α and BAL IL-8 were significantly (p < 0.01) increased over baseline at 6 h post-BSD. Increased numbers of neutrophils were observed in the whole blood (3.1 × 109 cells/L [95% confidence interval (CI) 2.06-4.14] vs. 6 × 109 cells/L [95%CI 3.92-7.97]; p < 0.01) and BAL (4.5 × 109 cells/L [95%CI 0.41-9.41] vs. 26 [95%CI 12.29-39.80]; p = 0.03) after 6 h of BSD induction vs baseline. A significant increase in ANP production (20.28 pM [95%CI 16.18-24.37] vs. 78.68 pM [95%CI 53.16-104.21]; p < 0.0001) and cTnI release (0.039 ng/mL vs. 4.26 [95%CI 2.69-5.83] ng/mL; p < 0.0001), associated with a significant reduction in heart contractile function, were observed between baseline and 6 h. CONCLUSIONS: BSD induced systemic pro-inflammatory responses, characterized by increased neutrophil infiltration and cytokine production in the circulation and BAL fluid, and associated with reduced heart contractile function in ovine model of BSD.


Subject(s)
Heart Diseases , Tumor Necrosis Factor-alpha , Sheep , Animals , Female , Tumor Necrosis Factor-alpha/metabolism , Interleukin-8 , Cytokines/metabolism , Brain Stem
6.
J Biomed Sci ; 27(1): 96, 2020 Oct 02.
Article in English | MEDLINE | ID: mdl-33008372

ABSTRACT

BACKGROUND: A lung transplant is the last resort treatment for many patients with advanced lung disease. The majority of donated lungs come from donors following brain death (BD). The endothelin axis is upregulated in the blood and lung of the donor after BD resulting in systemic inflammation, lung damage and poor lung graft outcomes in the recipient. Tezosentan (endothelin receptor blocker) improves the pulmonary haemodynamic profile; however, it induces adverse effects on other organs at high doses. Application of ex vivo lung perfusion (EVLP) allows the development of organ-specific hormone resuscitation, to maximise and optimise the donor pool. Therefore, we investigate whether the combination of EVLP and tezosentan administration could improve the quality of donor lungs in a clinically relevant 6-h ovine model of brain stem death (BSD). METHODS: After 6 h of BSD, lungs obtained from 12 sheep were divided into two groups, control and tezosentan-treated group, and cannulated for EVLP. The lungs were monitored for 6 h and lung perfusate and tissue samples were processed and analysed. Blood gas variables were measured in perfusate samples as well as total proteins and pro-inflammatory biomarkers, IL-6 and IL-8. Lung tissues were collected at the end of EVLP experiments for histology analysis and wet-dry weight ratio (a measure of oedema). RESULTS: Our results showed a significant improvement in gas exchange [elevated partial pressure of oxygen (P = 0.02) and reduced partial pressure of carbon dioxide (P = 0.03)] in tezosentan-treated lungs compared to controls. However, the lungs hematoxylin-eosin staining histology results showed minimum lung injuries and there was no difference between both control and tezosentan-treated lungs. Similarly, IL-6 and IL-8 levels in lung perfusate showed no difference between control and tezosentan-treated lungs throughout the EVLP. Histological and tissue analysis showed a non-significant reduction in wet/dry weight ratio in tezosentan-treated lung tissues (P = 0.09) when compared to control. CONCLUSIONS: These data indicate that administration of tezosentan could improve pulmonary gas exchange during EVLP.


Subject(s)
Endothelin Receptor Antagonists/pharmacology , Lung/drug effects , Pyridines/pharmacology , Respiratory Function Tests , Tetrazoles/pharmacology , Vasodilator Agents/pharmacology , Animals , Disease Models, Animal , Lung/physiology , Perfusion , Sheep, Domestic , Tissue Donors
7.
Br J Anaesth ; 122(2): 269-276, 2019 Feb.
Article in English | MEDLINE | ID: mdl-30686313

ABSTRACT

BACKGROUND: Recruitment manoeuvres generate a transient increase in trans-pulmonary pressure that could open collapsed alveoli. Recruitment manoeuvres might generate very high inspiratory airflows. We evaluated whether recruitment manoeuvres could displace respiratory secretions towards the distal airways and impair gas exchange in a porcine model of bacterial pneumonia. METHODS: We conducted a prospective randomised study in 10 mechanically ventilated pigs. Pneumonia was produced by direct intra-bronchial introduction of Pseudomonas aeruginosa. Four recruitment manoeuvres were applied randomly: extended sigh (ES), maximal recruitment strategy (MRS), sudden increase in driving pressure and PEEP (SI-PEEP), and sustained inflation (SI). Mucus transport was assessed by fluoroscopic tracking of radiopaque disks before and during each recruitment manoeuvre. The effects of each RM on gas exchange were assessed 15 min after the intervention. RESULTS: Before recruitment manoeuvres, mucus always cleared towards the glottis. Conversely, mucus was displaced towards the distal airways in 28.6% ES applications and 50% of all other recruitment manoeuvres (P=0.053). Median mucus velocity was 1.26 mm min-1 [0.48-3.89] before each recruitment manoeuvre, but was reversed (P=0.007) during ES [0.10 mm min-1 [-0.04-1.00]], MRS [0.10 mm min-1 [-0.4-0.48]], SI-PEEP [0.02 mm min-1 [-0.14-0.34]], and SI [0.10 mm min-1 [-0.63-0.75]]. When PaO2 failed to improve after recruitment manoeuvre, mucus was displaced towards the distal airways in 68.7% of the cases, compared with 31.2% recruitment manoeuvres associated with improved PaO2 (odds ratio: 4.76 (95% confidence interval: 1.13-19.97). CONCLUSIONS: Recruitment manoeuvres dislodge mucus distally, irrespective of airflow generated by different recruitment manoeuvres. Further investigation in humans is warranted to corroborate these pre clinical findings, as there may be limited benefits associated with lung recruitment in pneumonia.


Subject(s)
Airway Management/methods , Intubation, Intratracheal/methods , Mucus , Pneumonia, Bacterial/complications , Animals , Disease Models, Animal , Female , Peak Expiratory Flow Rate , Prospective Studies , Pseudomonas aeruginosa , Pulmonary Gas Exchange , Respiration, Artificial , Respiratory Mechanics , Sus scrofa , Swine
8.
Clin Oncol (R Coll Radiol) ; 31(2): e11-e20, 2019 02.
Article in English | MEDLINE | ID: mdl-30454940

ABSTRACT

AIMS: Recently published international guidelines recommended using the stimulated thyroglobulin (sTg) post-radioactive iodine (RAI) ablation, in conjunction with tumour stage, as a risk stratification factor. The choice of cut-off values for sTg, namely 1 and 10 ng/ml, was, however, largely based on the functional sensitivities of the assays used, with relatively few published data addressing the prognostic impact of alternative cut-off values. Our study aims to provide data on the prognostic value of sTg at different levels of sensitivities and specificities. MATERIALS AND METHODS: We conducted a retrospective review of all adult cases of differentiated thyroid carcinoma receiving RAI ablation at our centre from 2008 to 2010. All patients had sTg measured at around 6 months post-ablation. The functional sensitivity of our assay was 0.5 ng/ml. The outcome was adverse clinical event, defined as cancer-related death, persistent macroscopic disease demonstrable on imaging (including radioisotope scan) and/or receiving further treatment for persistent or recurrent disease. A receiver operating characteristic (ROC) analysis was carried out. RESULTS: We identified 140 patients treated in the review period, with 106 of them suitable for further analysis. The reasons for exclusion included the presence of anti-thyroglobulin antibodies and medullary or anaplastic histological subtypes. Most (54.7%) had intermediate-risk disease as per the American Thyroid Association classification (2009). The median follow-up duration was 6.4 years; the minimum, excluding deaths, was 5.0 years. ROC analysis showed that the optimal cut-off value of sTg for predicting adverse clinical events was >1.0 ng/ml, associated with a sensitivity of 90.9%, a specificity of 81.0%, a positive predictive value of 55.6% and a negative predictive value of 97.1%. CONCLUSION: Based on ROC analysis of sensitivities and specificities, our data showed that a post-ablation sTg value of 1 ng/ml is the optimal cut-off in prognostication of adverse clinical events.


Subject(s)
Thyroglobulin/therapeutic use , Thyroid Neoplasms/blood , Thyroid Neoplasms/diagnosis , Adult , Aged , Female , Humans , Male , Middle Aged , Prognosis , Retrospective Studies , Risk Factors , Thyroglobulin/pharmacology , Thyroid Neoplasms/pathology
9.
Hong Kong Med J ; 24(1): 56-62, 2018 02.
Article in English | MEDLINE | ID: mdl-29326401

ABSTRACT

INTRODUCTION: The management of human epidermal growth factor receptor 2 (HER2)-positive breast cancer has changed dramatically with the introduction and widespread use of HER2-targeted therapies. There is, however, relatively limited real-world information about the effectiveness and safety of trastuzumab emtansine (T-DM1) in Hong Kong Chinese patients. We assessed the efficacy and toxicity profiles among local patients with HER2-positive advanced breast cancer who had received T-DM1 therapy in the second-line setting and beyond. METHODS: This retrospective study involved five local centres that provide service for over 80% of the breast cancer population in Hong Kong. The study period was from December 2013 to December 2015. Patients were included if they had recurrent or metastatic histologically confirmed HER2+ breast cancer who had progressed after at least one line of anti-HER2 therapy including trastuzumab. Patients were excluded if they received T-DM1 as first-line treatment for recurrent or metastatic HER2+ breast cancer. Patient charts including biochemical and haematological profiles were reviewed for background information, T-DM1 response, and toxicity data. Adverse events were documented during chemotherapy and 28 days after the last dose of medication. RESULTS: Among 37 patients being included in this study, 28 (75.7%) had two or more lines of anti-HER2 agents and 26 (70.3%) had received two or more lines of palliative chemotherapy. Response assessment revealed that three (8.1%) patients had a complete response, eight (21.6%) a partial response, 11 (29.7%) a stable disease, and 12 (32.4%) a progressive disease; three patients could not be assessed. The median duration of response was 17.3 (95% confidence interval, 8.4-24.8) months. The clinical benefit rate (complete response + partial response + stable disease, ≥12 weeks) was 37.8% (95% confidence interval, 22.2%-53.5%). The median progression-free survival was 6.0 (95% confidence interval, 3.3- 9.8) months and the median overall survival had not been reached by the data cut-off date. Grade 3 or 4 toxicities included thrombocytopaenia (13.5%), raised alanine transaminase (8.1%), anaemia (5.4%), and hypokalaemia (2.7%). No patient died as a result of toxicities. CONCLUSIONS: In patients with HER2-positive advanced breast cancer who have been heavily pretreated with anti-HER2 agents and cytotoxic chemotherapy, T-DM1 is well tolerated and provided a meaningful progression-free survival of 6 months and an overall survival that has not been reached. Further studies to identify appropriate patient subgroups are warranted.


Subject(s)
Antineoplastic Agents, Immunological/administration & dosage , Antineoplastic Agents, Immunological/adverse effects , Breast Neoplasms/drug therapy , Maytansine/analogs & derivatives , Trastuzumab/administration & dosage , Trastuzumab/adverse effects , Ado-Trastuzumab Emtansine , Adult , Aged , Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Breast Neoplasms/genetics , Breast Neoplasms/mortality , Female , Hong Kong/epidemiology , Humans , Maytansine/administration & dosage , Maytansine/adverse effects , Middle Aged , Receptor, ErbB-2/genetics , Retrospective Studies , Survival Analysis
10.
Crit Care Resusc ; 19(Suppl 1): 45-52, 2017 Oct.
Article in English | MEDLINE | ID: mdl-29084501

ABSTRACT

BACKGROUND AND OBJECTIVE: Venovenous extracorporeal membrane oxygenation (VV ECMO) and extracorporeal CO2 removal (ECCO2R) are increasingly used in the management of severe respiratory failure. With bleeding complications being one of the major risks of these techniques, our aim in this systematic review was to assess the available literature on acquired von Willebrand syndrome (AvWS) and extracorporeal support. AvWS has previously been associated with bleeding and shear stress. DESIGN AND DATA SOURCES: A systematic review, using Medline via PubMed, was performed to identify eligible studies up to January 2017. RESULTS AND CONCLUSION: The prevalence of AvWF among patients on VV ECMO or ECCO2R is high, but only a limited number of studies are reported in the literature. AvWS testing should be performed, including vWF multimer analysis, vWF activity and vWF antigen concentration. The extent to which vWF contributes to bleeding during ECMO, or how much changes in ECMO management can influence high molecular weight vWF multimer levels, cannot be answered from the currently available evidence and there remains a need for future studies.


Subject(s)
Extracorporeal Membrane Oxygenation/methods , Hemorrhage/complications , Respiratory Insufficiency , von Willebrand Diseases/diagnosis , Humans , von Willebrand Diseases/complications , von Willebrand Diseases/therapy , von Willebrand Factor
11.
Pharmacol Res ; 117: 328-342, 2017 03.
Article in English | MEDLINE | ID: mdl-27993717

ABSTRACT

Proteinase-activated receptor 2 (PAR2) is a G protein-coupled receptor involved in metabolism, inflammation, and cancers. It is activated by proteolysis, which exposes a nascent N-terminal sequence that becomes a tethered agonist. Short synthetic peptides corresponding to this sequence also activate PAR2, while small organic molecules show promising PAR2 antagonism. Developing PAR2 ligands into pharmaceuticals is hindered by a lack of knowledge of how synthetic ligands interact with and differentially modulate PAR2. Guided by PAR2 homology modeling and ligand docking based on bovine rhodopsin, followed by cross-checking with newer PAR2 models based on ORL-1 and PAR1, site-directed mutagenesis of PAR2 was used to investigate the pharmacology of three agonists (two synthetic agonists and trypsin-exposed tethered ligand) and one antagonist for modulation of PAR2 signaling. Effects of 28 PAR2 mutations were examined for PAR2-mediated calcium mobilization and key mutants were selected for measuring ligand binding. Nineteen of twenty-eight PAR2 mutations reduced the potency of at least one ligand by >10-fold. Key residues mapped predominantly to a cluster in the transmembrane (TM) domains of PAR2, differentially influence intracellular Ca2+ induced by synthetic agonists versus a native agonist, and highlight subtly different TM residues involved in receptor activation. This is the first evidence highlighting the importance of the PAR2 TM regions for receptor activation by synthetic PAR2 agonists and antagonists. The trypsin-cleaved N-terminus that activates PAR2 was unaffected by residues that affected synthetic peptides, challenging the widespread practice of substituting peptides for proteases to characterize PAR2 physiology.


Subject(s)
Calcium Signaling/drug effects , Membrane Proteins/metabolism , Peptides/pharmacology , Receptor, PAR-2/metabolism , Animals , CHO Cells , Calcium/metabolism , Cattle , Cell Line , Cricetulus , Humans , Ligands , Mutagenesis, Site-Directed/methods , Mutation/drug effects , Protein Domains/physiology , Trypsin/metabolism
12.
Clin Nutr ESPEN ; 16: 16-23, 2016 Dec.
Article in English | MEDLINE | ID: mdl-28531450

ABSTRACT

BACKGROUND & AIMS: Malnutrition is prevalent in vascular surgical patients who commonly seek tertiary care at advanced stages of disease. Adjunct nutrition support is therefore pertinent to optimise patient outcomes. To negate consequences related to excessive or suboptimal dietary energy intake, it is essential to accurately determine energy expenditure and subsequent requirements. This study aims to compare resting energy expenditure (REE) measured by indirect calorimetry, a commonly used comparator, to REE estimated by predictive equations (Schofield, Harris-Benedict equations and Miller equation) to determine the most suitable equation for vascular surgery patients. METHODS: Data were collected from four studies that measured REE in 77 vascular surgery patients. Bland-Altman analyses were conducted to explore agreement. Presence of fixed or proportional bias was assessed by linear regression analyses. RESULTS: In comparison to measured REE, on average REE was overestimated when Schofield (+857 kJ/day), Harris-Benedict (+801 kJ/day) and Miller (+71 kJ/day) equations were used. Wide limits of agreement led to an over or underestimation from 1552 to 1755 kJ. Proportional bias was absent in Schofield (R2 = 0.005, p = 0.54) and Harris-Benedict equations (R2 = 0.045, p = 0.06) but was present in the Miller equation (R2 = 0.210, p < 0.01) even after logarithmic transformation (R2 = 0.213, p < 0.01). CONCLUSIONS: Whilst the Miller equation tended to overestimate resting energy expenditure and was affected by proportional bias, the limits of agreement and mean bias were smaller compared to Schofield and Harris-Benedict equations. This suggested that it is the preferred predictive equation for vascular surgery patients. Future research to refine the Miller equation to improve its overall accuracy will better inform the provision of nutritional support for vascular surgery patients and subsequently improve outcomes. Alternatively, an equation might be developed specifically for use with vascular surgery patients.


Subject(s)
Energy Metabolism , Nutritional Status/physiology , Peripheral Arterial Disease/surgery , Vascular Surgical Procedures , Adult , Body Mass Index , Calorimetry, Indirect/methods , Energy Intake , Female , Humans , Male , Malnutrition , Mathematics , Middle Aged , Nutritional Support , Obesity , Predictive Value of Tests , Rest
13.
Br J Pharmacol ; 171(17): 4112-24, 2014 Sep.
Article in English | MEDLINE | ID: mdl-24821440

ABSTRACT

BACKGROUND AND PURPOSE: Proteinase activated receptor 2 (PAR2) is a GPCR associated with inflammation, metabolism and disease. Clues to understanding how to block PAR2 signalling associated with disease without inhibiting PAR2 activation in normal physiology could be provided by studies of biased signalling. EXPERIMENTAL APPROACH: PAR2 ligand GB88 was profiled for PAR2 agonist and antagonist properties by several functional assays associated with intracellular G-protein-coupled signalling in vitro in three cell types and with PAR2-induced rat paw oedema in vivo. KEY RESULTS: In HT29 cells, GB88 was a PAR2 antagonist in terms of Ca(2+) mobilization and PKC phosphorylation, but a PAR2 agonist in attenuating forskolin-induced cAMP accumulation, increasing ERK1/2 phosphorylation, RhoA activation, myosin phosphatase phosphorylation and actin filament rearrangement. In CHO-hPAR2 cells, GB88 inhibited Ca(2+) release, but activated G(i/o) and increased ERK1/2 phosphorylation. In human kidney tubule cells, GB88 inhibited cytokine secretion (IL6, IL8, GM-CSF, TNF-α) mediated by PAR2. A rat paw oedema induced by PAR2 agonists was also inhibited by orally administered GB88 and compared with effects of locally administered inhibitors of G-protein coupled pathways. CONCLUSIONS AND IMPLICATIONS: GB88 is a biased antagonist of PAR2 that selectively inhibits PAR2/G(q/11)/Ca(2+)/PKC signalling, leading to anti-inflammatory activity in vivo, while being an agonist in activating three other PAR2-activated pathways (cAMP, ERK, Rho) in human cells. These findings highlight opportunities to design drugs to block specific PAR2-linked signalling pathways in disease, without blocking beneficial PAR2 signalling in normal physiology, and to dissect PAR2-associated mechanisms of disease in vivo.


Subject(s)
Oligopeptides/pharmacology , Receptor, PAR-2/antagonists & inhibitors , Animals , CHO Cells , Cells, Cultured , Cricetulus , Cytokines/antagonists & inhibitors , Cytokines/metabolism , Dose-Response Relationship, Drug , HT29 Cells , Humans , Ligands , Oligopeptides/administration & dosage , Rats , Receptor, PAR-2/metabolism , Signal Transduction/drug effects , Structure-Activity Relationship
14.
Br J Pharmacol ; 171(5): 1180-94, 2014 Mar.
Article in English | MEDLINE | ID: mdl-24354792

ABSTRACT

Although it has been known since the 1960s that trypsin and chymotrypsin can mimic hormone action in tissues, it took until the 1990s to discover that serine proteinases can regulate cells by cleaving and activating a unique four-member family of GPCRs known as proteinase-activated receptors (PARs). PAR activation involves the proteolytic exposure of its N-terminal receptor sequence that folds back to function as a 'tethered' receptor-activating ligand (TL). A key N-terminal arginine in each of PARs 1 to 4 has been singled out as a target for cleavage by thrombin (PARs 1, 3 and 4), trypsin (PARs 2 and 4) or other proteases to unmask the TL that activates signalling via Gq , Gi or G12 /13 . Similarly, synthetic receptor-activating peptides, corresponding to the exposed 'TL sequences' (e.g. SFLLRN-, for PAR1 or SLIGRL- for PAR2) can, like proteinase activation, also drive signalling via Gq , Gi and G12 /13 , without requiring receptor cleavage. Recent data show, however, that distinct proteinase-revealed 'non-canonical' PAR tethered-ligand sequences and PAR-activating agonist and antagonist peptide analogues can induce 'biased' PAR signalling, for example, via G12 /13 -MAPKinase instead of Gq -calcium. This overview summarizes implications of this 'biased' signalling by PAR agonists and antagonists for the recognized roles the PARs play in inflammatory settings.


Subject(s)
Receptors, Proteinase-Activated/metabolism , Animals , Humans , Inflammation/drug therapy , Receptors, Proteinase-Activated/antagonists & inhibitors , Signal Transduction
15.
Psychooncology ; 22(12): 2831-9, 2013 Dec.
Article in English | MEDLINE | ID: mdl-24038545

ABSTRACT

BACKGROUND: Anxiety and depression (distress) over the first year following the initial adjuvant therapy for advanced breast cancer (ABC) remain poorly documented in non-Caucasian populations. This study describes trajectories of distress and their determinants in Chinese women with ABC. METHODS: Of the 228 Chinese women newly diagnosed with ABC recruited from six oncology units, 192 completed an interview before their first course of chemotherapy (baseline) and follow-up interviews at 1.5, 3, 6, and 12 months thereafter. At baseline, participants were assessed for supportive care needs, psychological distress, physical symptom distress, optimism, and cancer-related rumination. At follow-up, participants completed the measure of psychological distress. Latent growth mixture modeling was used to identify trajectory patterns of distress. Multinominal logistic regression was used to identify predictors of trajectory patterns adjusted for demographic and medical characteristics. RESULTS: Four distinct trajectories of anxiety and depression were identified. Most women showed low-stable levels of anxiety (68%) and depression (68%), but one in 11 women were chronically anxious (9%) and depressed (9%). Optimism, negative cancer-related rumination, and physical symptom distress predicted both anxiety and depression trajectories. Psychological needs predicted anxiety trajectories. Women in the low-stable distress group reported high optimism, low psychological supportive care needs, low physical symptom distress, and low negative cancer-related rumination. CONCLUSION: Most women with ABC did not experience psychological distress over 12 months following diagnosis of ABC. Preventive interventions should focus on women at risk of high persistent distress and reducing rumination, providing emotional support, and managing physical symptoms.


Subject(s)
Anxiety Disorders/psychology , Anxiety/psychology , Asian People/psychology , Breast Neoplasms/psychology , Depression/psychology , Depressive Disorder/psychology , Stress, Psychological/psychology , Adaptation, Psychological , Adult , Breast Neoplasms/pathology , Breast Neoplasms/therapy , Disease Progression , Female , Humans , Logistic Models , Longitudinal Studies , Middle Aged , Models, Psychological , Multivariate Analysis , Needs Assessment , Neoplasm Staging , Social Support
16.
Allergy ; 68(6): 780-7, 2013 Jun.
Article in English | MEDLINE | ID: mdl-23621474

ABSTRACT

BACKGROUND: Exposure to environmental hormones, such as alkylphenols, has been suggested to be associated with the development of asthma, but the mechanism of action remains unclear. OBJECTIVE: This study examined the effect of 4-nonylphenol (NP), one of the most important alkylphenols, on conventional dendritic cells (cDCs) and adaptive T-cell responses. It also explored the role of aryl hydrocarbon receptor (AhR) in NP's effect. METHODS: NP-conditioned bone marrow-derived DCs (BM-DCs) and splenic CD11c(+) cDCs were assessed regarding function in a murine model under conditions relevant to route and level of exposure in humans. RESULTS: Our results showed that splenic cDCs from NP-exposed mice have potent Th2-skewing ability and secrete increased levels of IL-6 and TNF-α, but not IL-10 and IL-12, at baseline and after stimulation with LPS. Further, bone marrow-derived DCs were cultured in the presence of NP and showed similar cytokine pattern and influenced the antigen-specific T cells secreting significantly less IFN-γ. Importantly, NP-exposed mice developed more severe OVA-induced allergic lung inflammation compared with control group. Interestingly, in a congenic strain of mice carrying low-affinity, ligand-binding mutant AhR (AhR(d) ), NP's effect on DC functions and lung inflammation was not observed in vitro and in vivo. CONCLUSION: These results suggested that NP may disturb physiologic function of DCs through, in part, AhR-dependent mechanisms, supporting the importance of NP exposure on the regulation of DC functions and allergic inflammation.


Subject(s)
Asthma/chemically induced , Environmental Pollutants/toxicity , Phenols/toxicity , Adaptive Immunity/drug effects , Animals , Asthma/immunology , Asthma/metabolism , Biomarkers/metabolism , CD4-Positive T-Lymphocytes/drug effects , CD4-Positive T-Lymphocytes/metabolism , Cytokines/metabolism , Dendritic Cells/drug effects , Dendritic Cells/immunology , Dendritic Cells/metabolism , Lung/immunology , Lung/metabolism , Lung/pathology , Mice , Mice, Inbred BALB C , Receptors, Aryl Hydrocarbon/metabolism
17.
Br J Pharmacol ; 165(5): 1413-23, 2012 Mar.
Article in English | MEDLINE | ID: mdl-21806599

ABSTRACT

BACKGROUND AND PURPOSE: Many cells express proteinase activated receptor 2 (PAR2) on their plasma membrane. PAR2 is activated by proteolytic enzymes, such as trypsin and tryptase that cleave the receptor N-terminus, inititating signalling to intracellular G proteins. Studies on PAR2 have relied heavily upon activating effects of proteases and peptide agonists that lack stability and bioavailability in vivo. EXPERIMENTAL APPROACH: A novel small molecule agonist GB110 and an antagonist GB88 were characterized in vitro against trypsin, peptide agonists, PAR2 antibody, PAR1 agonists and flow cytometry,in seven cell lines using intracellular Ca(2+) mobilization and examined in vivo against PAR2- and PAR1-induced rat paw oedema. KEY RESULTS: GB110 is a potent non-peptidic agonist activating PAR2-mediated Ca(2+) release in HT29 cells (EC(50) ∼200 nM) and six other human cell lines, inducing PAR2 internalization. GB88 is a unique PAR2 antagonist, inhibiting PAR2 activated Ca(2+) release (IC(50) ∼2 µM) induced by native (trypsin) or synthetic peptide and non-peptide agonists. GB88 was a competitive and surmountable antagonist of agonist 2f-LIGRLO-NH(2), a competitive but insurmountable antagonist of agonist GB110, and a non-competitive insurmountable antagonist of trypsin. GB88 was orally active and anti-inflammatory in vivo, inhibiting acute rat paw oedema elicited by agonist GB110 and proteolytic or peptide agonists of PAR2 but not by corresponding agonists of PAR1 or PAR4. CONCLUSIONS AND IMPLICATIONS: The novel PAR2 agonist and antagonist modulate intracellular Ca(2+) and rat paw oedema, providing novel molecular tools for examining PAR2-mediated diseases.


Subject(s)
Dipeptides/pharmacology , Isoxazoles/pharmacology , Oligopeptides/pharmacology , Piperidines/pharmacology , Receptor, PAR-2/agonists , Receptor, PAR-2/antagonists & inhibitors , Spiro Compounds/pharmacology , Animals , Anti-Inflammatory Agents/pharmacology , Calcium/metabolism , Cell Line , Edema/metabolism , HT29 Cells , Humans , Inflammation/drug therapy , Inflammation/metabolism , Oligopeptides/metabolism , Peptides/metabolism , Rats , Receptor, PAR-1/metabolism , Receptor, PAR-2/metabolism , Trypsin/metabolism
18.
Psychooncology ; 20(12): 1292-300, 2011 Dec.
Article in English | MEDLINE | ID: mdl-22114044

ABSTRACT

BACKGROUND: There is no instrument available in Chinese for assessing psychosocial needs. This study aimed to assess the validity and reliability of the Chinese version of the Supportive Care Needs Survey short form (SCNS-SF34-C) in Chinese women with breast cancer (BC). METHODS: The Chinese version of the 34-item SCNS-SF34-C, a self-report measure for assessing psychosocial unmet needs, was administered to 348 Chinese women with BC at the outpatient oncology unit. Exploratory factor analysis (EFA) tested the factor structure. The internal consistency, convergent, divergent, and discriminant validity of the identified factor structure were assessed. RESULTS: In contrast to the five-factor structure identified in the original 34-item SCNS-SF34, our EFA produced a 33-item solution accounting for 54% of score variance comprising four-factors: (1) Health system, information, and patient support, (2) Psychological needs, (3) Physical and daily living, and (4) Sexuality needs. Separate dimensions for Health system and information, and the Patient care and support domains were not supported. Cronbach alphas ranged from 0.75 to 0.92. Correlations of psychological and physical symptom distress measures indicated acceptable convergent validity. No correlation with optimism and positive affect measures indicated divergent validity. Discriminant validity was demonstrated by effective differentiation between clinically distinct patient groups (no active treatment versus active treatment; advanced BC versus localized BC). DISCUSSION: The Chinese version of the Supportive Care Needs Survey has suitable factor structure and psychometric properties for use in assessing psychosocial needs among Chinese women with BC. Further validation is needed for other cancer types.


Subject(s)
Breast Neoplasms/psychology , Surveys and Questionnaires/standards , Adult , Aged , Aged, 80 and over , Breast Neoplasms/therapy , China , Factor Analysis, Statistical , Female , Humans , Middle Aged , Needs Assessment , Psychology , Reproducibility of Results , Translating
19.
J Fish Biol ; 77(4): 972-84, 2010 Sep.
Article in English | MEDLINE | ID: mdl-20840624

ABSTRACT

This research proposes a simplified method for estimating the mesohabitat composition that would favour members of a given set of aquatic species. The simulated composition of four types of mesohabitat units (deep pool, shallow pool, deep riffle and shallow riffle) could guide the design of in-stream structures in creating pool-riffle systems with ecological reference. Fish community data and an autecology matrix are used to support the development of a stream mesohabitat simulation based on regression models for reaches in mid to upper-order streams. The fish community-mesohabitat model results constitute a reference condition that can be used to guide stream restoration and ecological engineering decisions aimed at maintaining the natural ecological integrity and diversity of rivers.


Subject(s)
Ecology/methods , Ecosystem , Fishes , Rivers , Animals , Regression Analysis
20.
Gene Ther ; 17(8): 972-9, 2010 Aug.
Article in English | MEDLINE | ID: mdl-20357829

ABSTRACT

Foxp3, a member of the forkhead transcription factor family, is a master gene that controls the development and function of CD4(+)CD25(+) regulatory T (Treg) cells. It is thought to contribute to pathogenesis of many different tumors, including ovarian carcinoma and pancreatic, breast and pancreatic ductal adenocarcinoma. Selectively depleted Foxp3-expressing cells with anit-CD25 antibodies or vaccination of Foxp3 mRNA-transfected dendritic cells engender protective immunity against tumor. This study targeted silencing Foxp3 gene expression using RNA interference (RNAi) delivered by a lentiviral vector to evaluate the therapeutic role of Foxp3 short-hairpin RNAs (shRNAs) in a murine model of leukemia. RLmale symbol1, a mouse CD4(+)CD25(+) leukemia cell with Foxp3 expression, was used as the leukemia animal model. By infecting RLmale symbol1 cells with Lenti-Foxp3-siRNA, we reduced Foxp3 gene expression and the suppressive function of CD4(+)CD25(-) effector cells stimulated with ConA. Moreover, lentiviral-mediated Foxp3 RNAi transduced into RLmale symbol1 cell or injected into the tumor showed suppressive effects on tumor growth and prolonged the survival of tumor-transplanted mice. However, this suppressive effect was abrogated in NOD-SCID mice transplanted with Lenti-Foxp3-siRNA-infected RLmale symbol1 cells. In conclusion, inhibiting Foxp3 gene expression by shRNAs effectively decreases tumor growth of Treg cell-like leukemia. The results may provide a novel strategy for future immunotherapy against cancers.


Subject(s)
Forkhead Transcription Factors/antagonists & inhibitors , Lentivirus/genetics , Leukemia, Experimental/therapy , Leukemia, T-Cell/therapy , RNA Interference , Animals , Cell Line, Tumor , Genetic Therapy , Leukemia, Experimental/genetics , Leukemia, T-Cell/genetics , Male , Mice , Mice, Inbred BALB C , RNA Stability
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