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Clinical relevance and therapeutic predictive ability of hypoxia biomarkers in head and neck cancer tumour models. Mol Oncol 2024. [PMID: 38426642 DOI: 10.1002/1878-0261.13620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 12/20/2023] [Accepted: 02/19/2024] [Indexed: 03/02/2024] Open
Abstract
Tumour hypoxia promotes poor patient outcomes, with particularly strong evidence for head and neck squamous cell carcinoma (HNSCC). To effectively target hypoxia, therapies require selection biomarkers and preclinical models that can accurately model tumour hypoxia. We established 20 patient-derived xenograft (PDX) and cell line-derived xenograft (CDX) models of HNSCC that we characterised for their fidelity to represent clinical HNSCC in gene expression, hypoxia status and proliferation and that were evaluated for their sensitivity to hypoxia-activated prodrugs (HAPs). PDX models showed greater fidelity in gene expression to clinical HNSCC than cell lines, as did CDX models relative to their paired cell lines. PDX models were significantly more hypoxic than CDX models, as assessed by hypoxia gene signatures and pimonidazole immunohistochemistry, and showed similar hypoxia gene expression to clinical HNSCC tumours. Hypoxia or proliferation status alone could not determine HAP sensitivity across our 20 HNSCC and two non-HNSCC tumour models by either tumour growth inhibition or killing of hypoxia cells in an ex vivo clonogenic assay. In summary, our tumour models provide clinically relevant HNSCC models that are suitable for evaluating hypoxia-targeting therapies; however, additional biomarkers to hypoxia are required to accurately predict drug sensitivity.
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Fragment-based and structure-guided discovery of perforin inhibitors. Eur J Med Chem 2023; 261:115786. [PMID: 37716187 DOI: 10.1016/j.ejmech.2023.115786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 08/24/2023] [Accepted: 08/31/2023] [Indexed: 09/18/2023]
Abstract
Perforin is a pore-forming protein whose normal function enables cytotoxic T and natural killer (NK) cells to kill virus-infected and transformed cells. Conversely, unwanted perforin activity can also result in auto-immune attack, graft rejection and aberrant responses to pathogens. Perforin is critical for the function of the granule exocytosis cell death pathway and is therefore a target for drug development. In this study, by screening a fragment library using NMR and surface plasmon resonance, we identified 4,4-diaminodiphenyl sulfone (dapsone) as a perforin ligand. We also found that dapsone has modest (mM) inhibitory activity of perforin lytic activity in a red blood cell lysis assay in vitro. Sequential modification of this lead fragment, guided by structural knowledge of the ligand binding site and binding pose, and supported by SPR and ligand-detected 19F NMR, enabled the design of nanomolar inhibitors of the cytolytic activity of intact NK cells against various tumour cell targets. Interestingly, the ligands we developed were largely inert with respect to direct perforin-mediated red blood cell lysis but were very potent in the context of perforin's action on delivering granzymes in the immune synapse, the context in which it functions physiologically. Our work indicates that a fragment-based, structure-guided drug discovery strategy can be used to identify novel ligands that bind perforin. Moreover, these molecules have superior physicochemical properties and solubility compared to previous generations of perforin ligands.
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Clonal dynamics limits detection of selection in tumour xenograft CRISPR/Cas9 screens. Cancer Gene Ther 2023; 30:1610-1623. [PMID: 37684549 PMCID: PMC10721547 DOI: 10.1038/s41417-023-00664-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 08/08/2023] [Accepted: 08/29/2023] [Indexed: 09/10/2023]
Abstract
Transplantable in vivo CRISPR/Cas9 knockout screens, in which cells are edited in vitro and inoculated into mice to form tumours, allow evaluation of gene function in a cancer model that incorporates the multicellular interactions of the tumour microenvironment. To improve our understanding of the key parameters for success with this method, we investigated the choice of cell line, mouse host, tumour harvesting timepoint and guide RNA (gRNA) library size. We found that high gRNA (80-95%) representation was maintained in a HCT116 subline transduced with the GeCKOv2 whole-genome gRNA library and transplanted into NSG mice when tumours were harvested at early (14 d) but not late time points (38-43 d). The decreased representation in older tumours was accompanied by large increases in variance in gRNA read counts, with notable expansion of a small number of random clones in each sample. The variable clonal dynamics resulted in a high level of 'noise' that limited the detection of gRNA-based selection. Using simulated datasets derived from our experimental data, we show that considerable reductions in count variance would be achieved with smaller library sizes. Based on our findings, we suggest a pathway to rationally design adequately powered in vivo CRISPR screens for successful evaluation of gene function.
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Evofosfamide for the treatment of human papillomavirus-negative head and neck squamous cell carcinoma. JCI Insight 2023; 8:169136. [PMID: 36810255 PMCID: PMC9990753 DOI: 10.1172/jci.insight.169136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023] Open
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Patient-Derived Xenograft and Organoid Models for Precision Medicine Targeting of the Tumour Microenvironment in Head and Neck Cancer. Cancers (Basel) 2020; 12:E3743. [PMID: 33322840 PMCID: PMC7763264 DOI: 10.3390/cancers12123743] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 12/10/2020] [Accepted: 12/10/2020] [Indexed: 12/24/2022] Open
Abstract
Patient survival from head and neck squamous cell carcinoma (HNSCC), the seventh most common cause of cancer, has not markedly improved in recent years despite the approval of targeted therapies and immunotherapy agents. Precision medicine approaches that seek to individualise therapy through the use of predictive biomarkers and stratification strategies offer opportunities to improve therapeutic success in HNSCC. To enable precision medicine of HNSCC, an understanding of the microenvironment that influences tumour growth and response to therapy is required alongside research tools that recapitulate the features of human tumours. In this review, we highlight the importance of the tumour microenvironment in HNSCC, with a focus on tumour hypoxia, and discuss the fidelity of patient-derived xenograft and organoids for modelling human HNSCC and response to therapy. We describe the benefits of patient-derived models over alternative preclinical models and their limitations in clinical relevance and how these impact their utility in precision medicine in HNSCC for the discovery of new therapeutic agents, as well as predictive biomarkers to identify patients' most likely to respond to therapy.
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Radiosensitization of head and neck squamous cell carcinoma lines by DNA-PK inhibitors is more effective than PARP-1 inhibition and is enhanced by SLFN11 and hypoxia. Int J Radiat Biol 2019; 95:1597-1612. [PMID: 31490091 DOI: 10.1080/09553002.2019.1664787] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Background and purpose: Poly(ADP-ribose)polymerase-1 (PARP1) and DNA-dependent protein kinase (DNA-PK) play key roles in the repair of radiation-induced DNA double strand breaks, but it is unclear which is the preferred therapeutic target in radiotherapy. Here we compare small molecule inhibitors of both as radiosensitizers of head and neck squamous cell carcinoma (HNSCC) cell lines.Methods: Two PARP1 inhibitors (olaparib, veliparib) and two DNA-PK inhibitors (KU57788, IC87361) were tested in 14 HNSCC cell lines and two non-tumorigenic lines (HEK-293 and WI-38/Va-13), with drug exposure for 6 or 24 h post-irradiation, using regrowth assays. For three lines (UT-SCC-54C, -74B, -76B), radiosensitization was also assessed by clonogenic assay under oxia and acute (6 h) anoxia, and for 54C cells under chronic hypoxia (0.2% O2 for 48 h). Relationships between sensitizer enhancement ratios (SER) and gene expression, assessed by RNA sequencing, were evaluated.Results: The inhibitors were minimally cytotoxic in the absence of radiation, with 74B and 54C cells the most sensitive to both olaparib and KU57788. Median SER values for each inhibitor at 1.1 µM were 1.12 (range 1.02-1.24) for olaparib, 1.08 (1.04-1.13) for veliparib, 1.35 (1.10-1.64) for IC87361 and 1.77 (1.41-2.38) for KU57788. The higher SER values for the DNA-PK inhibitors were observed with all cell lines (except HEK-293) and all concentrations tested and were confirmed by clonogenic assay. Radiosensitization by the DNA-PK inhibitors correlated with expression of SLFN11 mRNA. Radiosensitization by IC87361 and olaparib was significantly enhanced under acute anoxia and chronic hypoxia.Conclusions: The DNA-PK inhibitors KU57788 and IC87361 are more effective radiosensitizers than the PARP-1 inhibitors olaparib and veliparib at non-cytotoxic concentrations in HNSCC cell cultures and their activity is enhanced by SLFN11 and hypoxia.
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Evofosfamide for the treatment of human papillomavirus-negative head and neck squamous cell carcinoma. JCI Insight 2018; 3:122204. [PMID: 30135316 PMCID: PMC6141174 DOI: 10.1172/jci.insight.122204] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Accepted: 07/13/2018] [Indexed: 01/10/2023] Open
Abstract
Evofosfamide (TH-302) is a clinical-stage hypoxia-activated prodrug of a DNA-crosslinking nitrogen mustard that has potential utility for human papillomavirus (HPV) negative head and neck squamous cell carcinoma (HNSCC), in which tumor hypoxia limits treatment outcome. We report the preclinical efficacy, target engagement, preliminary predictive biomarkers and initial clinical activity of evofosfamide for HPV-negative HNSCC. Evofosfamide was assessed in 22 genomically characterized cell lines and 7 cell line-derived xenograft (CDX), patient-derived xenograft (PDX), orthotopic, and syngeneic tumor models. Biomarker analysis used RNA sequencing, whole-exome sequencing, and whole-genome CRISPR knockout screens. Five advanced/metastatic HNSCC patients received evofosfamide monotherapy (480 mg/m2 qw × 3 each month) in a phase 2 study. Evofosfamide was potent and highly selective for hypoxic HNSCC cells. Proliferative rate was a predominant evofosfamide sensitivity determinant and a proliferation metagene correlated with activity in CDX models. Evofosfamide showed efficacy as monotherapy and with radiotherapy in PDX models, augmented CTLA-4 blockade in syngeneic tumors, and reduced hypoxia in nodes disseminated from an orthotopic model. Of 5 advanced HNSCC patients treated with evofosfamide, 2 showed partial responses while 3 had stable disease. In conclusion, evofosfamide shows promising efficacy in aggressive HPV-negative HNSCC, with predictive biomarkers in development to support further clinical evaluation in this indication.
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Expression of the serine protease inhibitor neuroserpin in cells of the human myeloid lineage. Thromb Haemost 2017. [DOI: 10.1160/th06-09-0543] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
SummaryMyeloid progenitors in the bone marrow differentiate into most of the major cell types of the immune system, including macrophages and dendritic cells. These cells play important roles in both innate and adaptive immunity. They express a number of proteases and protease inhibitors including members of the serine proteinase inhibitor or serpin superfamily. In this study we report the differential expression of neuroserpin in cells of the human myeloid lineage. Neuroserpin was highly expressed and secreted following the differentiation of monocytes to macrophages and dendritic cells. Activation of dendritic cells with lipopolysaccharide resulted in increased neuroserpin mRNA levels but no neuroserpin secretion. Confocal immunofluorescence microscopy showed neuroserpin was differentially localised in human myeloid cells. In macrophages and dendritic cells it was concentrated in vesicles located in close proximity to the plasma membrane. The majority of activated dendritic cells also exhibited an intracellular focal concentration of neuroserpin which co-localised with the lysosomal/late endosomal marker LAMP-1. As neuroserpin inhibits tissue plasminogen activator, a comparative analysis of tPA and plasminogen activator inhibitor-1 (PAI-I) expression was undertaken. This analysis revealed differential expression of PAI-I and neuroserpin suggesting they may have different functions in human immune cells.
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Topical cystic fibrosis transmembrane conductance regulator gene replacement for cystic fibrosis-related lung disease. Paediatr Respir Rev 2017; 22:47-49. [PMID: 27964951 DOI: 10.1016/j.prrv.2016.10.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Accepted: 10/19/2016] [Indexed: 11/29/2022]
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Physiological and pathological functions of neuroserpin: Regulation of cellular responses through multiple mechanisms. Semin Cell Dev Biol 2017; 62:152-159. [PMID: 27639894 DOI: 10.1016/j.semcdb.2016.09.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Revised: 09/09/2016] [Accepted: 09/12/2016] [Indexed: 11/17/2022]
Abstract
It is 27 years since neuroserpin was first discovered in the nervous system and identified as a member of the serpin superfamily. Since that time potential roles for this serine protease inhibitor have been identified in neuronal and non-neuronal systems. Many are linked to inhibition of neuroserpin's principal enzyme target, tissue plasminogen activator (tPA), although some have been suggested to involve alternate non-inhibitory mechanisms. This review focuses mainly on the inhibitory roles of neuroserpin and discusses the evidence supporting tPA as the physiological target. While the major sites of neuroserpin expression are neural, endocrine and immune tissues, most progress on characterizing functional roles for neuroserpin have been in the brain. Roles in emotional behaviour, synaptic plasticity and neuroprotection in stroke and excitotoxicity models are discussed. Current knowledge on three neurological diseases associated with neuroserpin mutation or activity, Familial Encephalopathy with Neuroserpin Inclusion Bodies (FENIB), Alzheimer's disease and brain metastasis is presented. Finally, we consider mechanistic studies that have revealed a distinct inhibitory mechanism for neuroserpin and its possible implications for neuroserpin function.
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Association Interleukin-4 and Interleukin-4 Receptor Gene Polymorphism and Acute Rejection and Graft Dysfunction After Kidney Transplantation. Transplant Proc 2017; 48:813-9. [PMID: 27234743 DOI: 10.1016/j.transproceed.2015.12.059] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Revised: 11/25/2015] [Accepted: 12/30/2015] [Indexed: 11/15/2022]
Abstract
BACKGROUND Cytokine genotypes have previously been studied in patients undergoing solid organ transplantation; certain polymorphisms have been implicated in the development of acute rejection (AR) and graft dysfunction (GD). Allograft outcomes determined, in part, by alloimmune responses is mainly mediated by T-cell responses, activated and driven by cytokines. Interleukin-4 (IL-4) is one such cytokine, which exerts its biological effects through binding to the IL-4 receptor (IL-4R) complex on target cells. In the present study, we investigated whether polymorphisms of the IL-4 and/or IL-4R gene were associated with susceptibility to acute AR and GD after kidney transplantation. METHODS We analyzed 2 single nucleotide polymorphism (SNPs) of IL-4 (rs2243250 and rs2070874) and 3 SNPs of IL-4R (rs1801275, rs2107356, and rs1805010) in 344 kidney transplant recipients. These patients included 62 of whom had developed AR and 215 of whom had GD in 1 year after kidney transplantation. RESULTS The AR group included 62 patients (45 men and 17 women). There was a statistically significant difference in the male-to-female ratio and the use of tacrolimus in the AR group. The GD group included 215 patients. Patients who developed GD were more likely to be older and have an underlying cause of end-stage renal disease that was unknown compared with patients who did not have GD, the cause of which was typically known. Among the SNPs examined, 1 of the SNPs in the IL-4R gene (ie, rs1801275) showed a statistical association with AR (co-dominant model, P = .061; dominant model, P = .019; and log-addictive model, P = .029). In addition, 1 of the IL-4R SNPs (ie, rs2107356) was statistically associated with GD (dominant model, P = .034). No significant difference in the IL-4 genotype was observed between the AR/GD and non-AR/non-GD subjects. CONCLUSIONS One IL-4R gene polymorphism (rs1801275) was associated with AR. In addition, a separate IL-4R SNP (rs2107356) was statistically associated with GD after kidney transplantation.
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Implementing standard setting into the Conjoint MAFP/FRACGP Part 1 examination - Process and issues. MALAYSIAN FAMILY PHYSICIAN : THE OFFICIAL JOURNAL OF THE ACADEMY OF FAMILY PHYSICIANS OF MALAYSIA 2016; 11:2-8. [PMID: 28461851 PMCID: PMC5408869] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
BACKGROUND The College of General Practitioners of Malaysia and the Royal Australian College of General Practitioners held the first Conjoint Member of the College of General Practitioners (MCGP)/Fellow of Royal Australian College of General Practitioners (FRACGP) examination in 1982, later renamed the Conjoint MAFP/FRACGP examinations. The examination assesses competency for safe independent general practice and as family medicine specialists in Malaysia. Therefore, a defensible standard set pass mark is imperative to separate the competent from the incompetent. OBJECTIVE This paper discusses the process and issues encountered in implementing standard setting to the Conjoint Part 1 examination. DISCUSSION Critical to success in standard setting were judges' understanding of the process of the modified Angoff method, defining the borderline candidate's characteristics and the composition of judges. These were overcome by repeated hands-on training, provision of detailed guidelines and careful selection of judges. In December 2013, 16 judges successfully standard set the Part 1 Conjoint examinations, with high inter-rater reliability: Cronbach's alpha coefficient 0.926 (Applied Knowledge Test), 0.921 (Key Feature Problems).
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Abstract
AIM This study aimed to assess the intent to enrol in a master of nursing programme among Bangladesh nurses, identify preferred programme options and measure the association among intent to enrol in the programme, clinical competency and job satisfaction. BACKGROUND Personal and professional aspects of potential students pursuing graduate education are beneficial in devising educational strategies. However, considering the pressing needs for higher nursing education, there are no masters of nursing programmes in Bangladesh. METHODS This study used a descriptive correlational design. Nurses working in Bangladesh public sector were recruited to participate in a self-administered survey (n = 260). The questionnaire consisted of perception of job satisfaction, clinical competency and the need for educational options, including the intent to enrol in a master of nursing programme, preferred specialty area, curriculum content and career goals after graduation. Data were analysed using descriptive statistics and point-biserial correlation. RESULTS Ninety per cent of the respondents reported that they intended to enrol in a master of nursing programme. Intention was significantly correlated with clinical competency but not with job satisfaction. The most preferred specialty areas were nursing management and education. Half of the respondents responded that teaching at nursing schools was a career goal after graduation. DISCUSSION The results of the needs assessment for the programme reflected the unique interest and priorities of the current status of Bangladesh. CONCLUSIONS The results indicate a strong motivation to enrol in a master of nursing programme, confidence in clinical competence and high demand for programme in nursing management and education. These findings should be considered to design the programme in order to meet the interest of Bangladesh nurses. IMPLICATIONS FOR NURSING AND HEALTH POLICY Educational needs assessments should take precedence to ensure the best possible educational outcome and to produce competent nurses who will contribute in achieving the Millennium Development Goals of Bangladesh.
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Physiologic Changes in the Heart Following Cessation of Mechanical Ventilation in a Porcine Model of Donation After Circulatory Death: Implications for Cardiac Transplantation. Am J Transplant 2016; 16:783-93. [PMID: 26663659 DOI: 10.1111/ajt.13543] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Revised: 08/31/2015] [Accepted: 09/18/2015] [Indexed: 01/25/2023]
Abstract
Hearts donated following circulatory death (DCD) may represent an additional source of organs for transplantation; however, the impact of donor extubation on the DCD heart has not been well characterized. We sought to describe the physiologic changes that occur following withdrawal of life-sustaining therapy (WLST) in a porcine model of DCD. Physiologic changes were monitored continuously for 20 min following WLST. Ventricular pressure, volume, and function were recorded using a conductance catheter placed into the right (N = 8) and left (N = 8) ventricles, and using magnetic resonance imaging (MRI, N = 3). Hypoxic pulmonary vasoconstriction occurred following WLST, and was associated with distension of the right ventricle (RV) and reduced cardiac output. A 120-fold increase in epinephrine was subsequently observed that produced a transient hyperdynamic phase; however, progressive RV distension developed during this time. Circulatory arrest occurred 7.6±0.3 min following WLST, at which time MRI demonstrated an 18±7% increase in RV volume and a 12±9% decrease in left ventricular volume compared to baseline. We conclude that hypoxic pulmonary vasoconstriction and a profound catecholamine surge occur following WLST that result in distension of the RV. These changes have important implications on the resuscitation, preservation, and evaluation of DCD hearts prior to transplantation.
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Avoidance of Profound Hypothermia During Initial Reperfusion Improves the Functional Recovery of Hearts Donated After Circulatory Death. Am J Transplant 2016; 16:773-82. [PMID: 26780159 DOI: 10.1111/ajt.13574] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2015] [Revised: 08/17/2015] [Accepted: 08/31/2015] [Indexed: 01/25/2023]
Abstract
The resuscitation of hearts donated after circulatory death (DCD) is gaining widespread interest; however, the method of initial reperfusion (IR) that optimizes functional recovery has not been elucidated. We sought to determine the impact of IR temperature on the recovery of myocardial function during ex vivo heart perfusion (EVHP). Eighteen pigs were anesthetized, mechanical ventilation was discontinued, and cardiac arrest ensued. A 15-min standoff period was observed and then hearts were reperfused for 3 min at three different temperatures (5°C; N = 6, 25°C; N = 5, and 35°C; N = 7) with a normokalemic adenosine-lidocaine crystalloid cardioplegia. Hearts then underwent normothermic EVHP for 6 h during which time myocardial function was assessed in a working mode. We found that IR coronary blood flow differed among treatment groups (5°C = 483 ± 53, 25°C = 722 ± 60, 35°C = 906 ± 36 mL/min, p < 0.01). During subsequent EVHP, less myocardial injury (troponin I: 5°C = 91 ± 6, 25°C = 64 ± 16, 35°C = 57 ± 7 pg/mL/g, p = 0.04) and greater preservation of endothelial cell integrity (electron microscopy injury score: 5°C = 3.2 ± 0.5, 25°C = 1.8 ± 0.2, 35°C = 1.7 ± 0.3, p = 0.01) were evident in hearts initially reperfused at warmer temperatures. IR under profoundly hypothermic conditions impaired the recovery of myocardial function (cardiac index: 5°C = 3.9 ± 0.8, 25°C = 6.2 ± 0.4, 35°C = 6.5 ± 0.6 mL/minute/g, p = 0.03) during EVHP. We conclude that the avoidance of profound hypothermia during IR minimizes injury and improves the functional recovery of DCD hearts.
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Physiological and pathological roles of tissue plasminogen activator and its inhibitor neuroserpin in the nervous system. Front Cell Neurosci 2015; 9:396. [PMID: 26528129 PMCID: PMC4602146 DOI: 10.3389/fncel.2015.00396] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Accepted: 09/22/2015] [Indexed: 12/03/2022] Open
Abstract
Although its roles in the vascular space are most well-known, tissue plasminogen activator (tPA) is widely expressed in the developing and adult nervous system, where its activity is believed to be regulated by neuroserpin, a predominantly brain-specific member of the serpin family of protease inhibitors. In the normal physiological state, tPA has been shown to play roles in the development and plasticity of the nervous system. Ischemic damage, however, may lead to excess tPA activity in the brain and this is believed to contribute to neurodegeneration. In this article, we briefly review the physiological and pathological roles of tPA in the nervous system, which includes neuronal migration, axonal growth, synaptic plasticity, neuroprotection and neurodegeneration, as well as a contribution to neurological disease. We summarize tPA's multiple mechanisms of action and also highlight the contributions of the inhibitor neuroserpin to these processes.
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Tissue plasminogen activator inhibits NMDA-receptor-mediated increases in calcium levels in cultured hippocampal neurons. Front Cell Neurosci 2015; 9:404. [PMID: 26500501 PMCID: PMC4598481 DOI: 10.3389/fncel.2015.00404] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Accepted: 09/23/2015] [Indexed: 01/15/2023] Open
Abstract
NMDA receptors (NMDARs) play a critical role in neurotransmission, acting as essential mediators of many forms of synaptic plasticity, and also modulating aspects of development, synaptic transmission and cell death. NMDAR-induced responses are dependent on a range of factors including subunit composition and receptor location. Tissue-type plasminogen activator (tPA) is a serine protease that has been reported to interact with NMDARs and modulate NMDAR activity. In this study we report that tPA inhibits NMDAR-mediated changes in intracellular calcium levels in cultures of primary hippocampal neurons stimulated by low (5 μM) but not high (50 μM) concentrations of NMDA. tPA also inhibited changes in calcium levels stimulated by presynaptic release of glutamate following treatment with bicucculine/4-aminopyridine (4-AP). Inhibition was dependent on the proteolytic activity of tPA but was unaffected by α2-antiplasmin, an inhibitor of the tPA substrate plasmin, and receptor-associated protein (RAP), a pan-ligand blocker of the low-density lipoprotein receptor, two proteins previously reported to modulate NMDAR activity. These findings suggest that tPA can modulate changes in intracellular calcium levels in a subset of NMDARs expressed in cultured embryonic hippocampal neurons through a mechanism that involves the proteolytic activity of tPA and synaptic NMDARs.
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Chemicals eluting from disposable plastic syringes and syringe filters alter neurite growth, axogenesis and the microtubule cytoskeleton in cultured hippocampal neurons. J Neurochem 2015; 133:53-65. [PMID: 25522164 DOI: 10.1111/jnc.13009] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Revised: 11/27/2014] [Accepted: 11/28/2014] [Indexed: 12/29/2022]
Abstract
Cultures of dissociated hippocampal neurons are often used to study neuronal cell biology. We report that the development of these neurons is strongly affected by chemicals leaching from commonly used disposable medical-grade syringes and syringe filters. Contamination of culture medium by bioactive substance(s) from syringes and filters occurred with multiple manufacturing lots and filter types under normal use conditions and resulted in changes to neurite growth, axon formation and the neuronal microtubule cytoskeleton. The effects on neuronal morphology were concentration dependent and significant effects were detected even after substantial dilution of the contaminated medium. Gas chromatography-mass spectrometry analyses revealed many chemicals eluting from the syringes and filters. Three of these chemicals (stearic acid, palmitic acid and 1,2-ethanediol monoacetate) were tested but showed no effects on neurite growth. Similar changes in neuronal morphology were seen with high concentrations of bisphenol A and dibutyl phthalate, two hormonally active plasticisers. Although no such compounds were detected by gas chromatography–mass spectrometry, unknown plasticisers in leachates may affect neurites. This is the first study to show that leachates from laboratory consumables can alter the growth of cultured hippocampal neurons. We highlight important considerations to ensure leachate contamination does not compromise cell biology experiments.
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An analysis approach to identify specific functional sites in orthologous proteins using sequence and structural information: application to neuroserpin reveals regions that differentially regulate inhibitory activity. Proteins 2015; 83:135-52. [PMID: 25363759 DOI: 10.1002/prot.24711] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Revised: 10/22/2014] [Accepted: 10/27/2014] [Indexed: 01/12/2023]
Abstract
The analysis of sequence conservation is commonly used to predict functionally important sites in proteins. We have developed an approach that first identifies highly conserved sites in a set of orthologous sequences using a weighted substitution-matrix-based conservation score and then filters these conserved sites based on the pattern of conservation present in a wider alignment of sequences from the same family and structural information to identify surface-exposed sites. This allows us to detect specific functional sites in the target protein and exclude regions that are likely to be generally important for the structure or function of the wider protein family. We applied our method to two members of the serpin family of serine protease inhibitors. We first confirmed that our method successfully detected the known heparin binding site in antithrombin while excluding residues known to be generally important in the serpin family. We next applied our sequence analysis approach to neuroserpin and used our results to guide site-directed polyalanine mutagenesis experiments. The majority of the mutant neuroserpin proteins were found to fold correctly and could still form inhibitory complexes with tissue plasminogen activator (tPA). Kinetic analysis of tPA inhibition, however, revealed altered inhibitory kinetics in several of the mutant proteins, with some mutants showing decreased association with tPA and others showing more rapid dissociation of the covalent complex. Altogether, these results confirm that our sequence analysis approach is a useful tool that can be used to guide mutagenesis experiments for the detection of specific functional sites in proteins.
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The use of internal laryngeal pressure to improve the laryngeal view in a patient with a difficult airway. Anaesth Intensive Care 2012; 40:736-737. [PMID: 22813522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
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The serine protease inhibitor neuroserpin regulates the growth and maturation of hippocampal neurons through a non-inhibitory mechanism. J Neurochem 2012; 121:561-74. [PMID: 22191421 DOI: 10.1111/j.1471-4159.2011.07639.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Neuroserpin is a brain-specific serine protease inhibitor that is expressed in the developing and adult nervous system. Its expression profile led to suggestions that it played roles in neuronal growth and connectivity. In this study, we provide direct evidence to support a role for neuroserpin in axon and dendritic growth. We report that axon growth is enhanced while axon and dendrite diameter are reduced following neuroserpin treatment of hippocampal neurons. More complex effects are seen on dendritic growth and branching with neuroserpin-stimulating dendritic growth and branching in young neurons but switching to an inhibitory response in older neurons. The protease inhibitory activity of neuroserpin is not required to activate changes in neuronal morphology and a proportion of responses are modulated by an antagonist to the LRP1 receptor. Collectively, these findings support a key role for neuroserpin as a regulator of neuronal development through a non-inhibitory mechanism and suggest a basis for neuroserpin's effects on complex emotional behaviours and recent link to schizophrenia.
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Value of alpha-foetoprotein for screening of recurrence in hepatocellular carcinoma post resection. Singapore Med J 2012; 53:32-35. [PMID: 22252180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
INTRODUCTION The aim of this study was to establish the value of alpha-foetoprotein (AFP) for the screening of recurrences in hepatocellular carcinoma (HCC) in patients who have undergone curative hepatic resection. METHODS 72 HCC patients who had curative resection/liver transplant in 2000-2006 were monitored for recurrence by evaluating the three- or six-monthly AFP and computed tomography images. Patients without recurrence were followed up for a mean duration of 7.27 years. RESULTS Out of the 72 patients, 34 (47.2%) suffered from HCC recurrence. 65.4% of recurrent cases had AFP values showing an upward trend. Patients with recurrence had higher AFP values than those without at last follow-up (119.45 μg/L vs. 3.1 μg/L, p < 0.001). AFP at recurrence was independent of gender, race, history of alcohol consumption and hepatitis C or cirrhosis status. Patient with hepatitis B or those with tumours larger than 5 cm had higher AFP values. The best cut-off AFP indicative of HCC recurrence was 5.45 μg/L (sensitivity 84.4%; specificity 77.1%). High preoperative AFP was associated with high AFP at recurrence (correlation coefficient 0.553, p = 0.01). CONCLUSION AFP alone is an inadequate screening test for HCC recurrence since only about two-thirds of patients showed upward AFP trend on recurrence. Our study found a relatively low cut-off point for detection of recurrence (5.54 μg/L). Patients with high preoperative AFP tended to have high AFP on recurrence. Imaging is recommended for patients with AFP levels > 5.45 μg/L, especially when AFP shows a rising trend.
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Hearts from DCD donors display acceptable biventricular function after heart transplantation in pigs. Am J Transplant 2011; 11:1621-32. [PMID: 21749639 DOI: 10.1111/j.1600-6143.2011.03622.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Cardiac transplantation is in decline, in contrast to other solid organs where the number of solid organ transplants from donors after circulatory death (DCD) is increasing. Hearts from DCD donors are not currently utilized due to concerns that they may suffer irreversible cardiac injury with resultant poor graft function. Using a large animal model, we tested the hypothesis that hearts from DCD donors would be suitable for transplantation. Donor pigs were subjected to hypoxic cardiac arrest (DCD) followed by 15 min of warm ischemia and resuscitation on cardiopulmonary bypass, or brainstem death (BSD) via intracerebral balloon inflation. Cardiac function was assessed through load-independent measures and magnetic resonance imaging and spectroscopy. After resuscitation, DCD hearts had near normal contractility, although stroke volume was reduced, comparable to BSD hearts. DCD hearts had a significant decline in phosphocreatine and increase in inorganic phosphate during the hypoxic period, with a return to baseline levels after reperfusion. After transplantation, cardiac function was comparable between BSD and DCD groups. Therefore, in a large animal model, the DCD heart maintains viability and recovers function similar to that of the BSD heart and may be suitable for clinical transplantation. Further study is warranted on optimal reperfusion strategies.
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A one-hour infusion of infliximab during maintenance therapy is safe and well tolerated: a prospective cohort study. Aliment Pharmacol Ther 2011; 34:181-7. [PMID: 21615434 DOI: 10.1111/j.1365-2036.2011.04699.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
BACKGROUND Infliximab is a chimeric monoclonal antibody to tumour necrosis factor alpha (TNFα) with efficacy in inducing and maintaining remission of inflammatory bowel disease, rheumatoid arthritis, ankylosing spondylitis and psoriasis. Infliximab is generally administered over 2h with a further 1-h postinfusion observation. This time interval has substantial impact on healthcare resources and is costly in terms of patient's time away from work. AIM To examine the safety and tolerability of a 1-h, relative to a 2-h maintenance of infusion of infliximab, and to determine the effect of corticosteroid premedication and concurrent immunosuppressor use on infusion reaction rates. METHOD A prospective cohort study with variable follow-up duration of 2165 consecutive infliximab infusions in 415 patients during 2009 was conducted. Diagnosis, infusion episode number, infusion rate, premedication, concurrent immunosuppressor therapy, the nature and the outcome of infusion reactions were examined. RESULTS The majority of infusions (74%) were for management of inflammatory bowel disease. Infusion reactions clustered within the first eight infusions with subsequent sporadic reactions. The infusion reaction incidence rate per 1000 person days in 274 1-h infusions from 54 patients and 1356 2-h infusions from 256 patients were 0.08 and 0.28 respectively (P=0.07). Poisson regression model confirmed that the concurrent use of immunosuppressor therapy was associated with a lower infusion reaction rate, whereas corticosteroid premedication was not. CONCLUSIONS During maintenance therapy, infliximab infusion can be safely administered over 1h in patients with no past history of significant infliximab infusion reaction. Corticosteroid premedication had no impact on the infusion reaction rates.
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Degradation of malachite green in aqueous solution by Fenton process. JOURNAL OF HAZARDOUS MATERIALS 2009; 164:468-72. [PMID: 18804913 DOI: 10.1016/j.jhazmat.2008.08.018] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2008] [Revised: 08/08/2008] [Accepted: 08/08/2008] [Indexed: 05/03/2023]
Abstract
In this study, advanced oxidation process utilizing Fenton's reagent was investigated for degradation of malachite green (MG). The effects of different reaction parameters such as the initial MG concentration, initial pH, the initial hydrogen peroxide concentration, the initial ferrous concentration and the reaction temperature on the oxidative degradation of MG have been investigated. The optimal reacting conditions were experimentally found to be pH 3.40, initial hydrogen peroxide concentration=0.50mM and initial ferrous concentration=0.10mM for initial MG concentration of 20mg/L at 30 degrees C. Under optimal conditions, 99.25% degradation efficiency of dye in aqueous solution was achieved after 60 min of reaction.
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Neuroserpin regulates N-cadherin-mediated cell adhesion independently of its activity as an inhibitor of tissue plasminogen activator. J Neurosci Res 2008; 86:1243-53. [PMID: 18092357 DOI: 10.1002/jnr.21592] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Neuroserpin is an inhibitor of tissue plasminogen activator (tPA) that is expressed in developing and adult nervous systems. Spatial and temporal analysis of neuroserpin expression suggests that it is involved in regulating the proteolytic balance associated with axonogenesis and synaptogenesis during development and synaptic plasticity in the adult. Here we demonstrate that altered expression of neuroserpin modulates the degree of cell-cell adhesion in pheochromocytoma PC12 cells independently of its role as an inhibitor of tPA. Levels of the homophilic cell-cell adhesion molecule N-cadherin are increased in neuroserpin-overexpressing cell lines. N-cadherin immunoreactivity was detected in a Triton X-100-insoluble fraction and localized to regions of cell contact, consistent with a role in enhancing cell surface adhesion. PC12 cell lines expressing neuroserpin mutants that lack tPA inhibitory activity also showed increased cell-cell adhesion and N-cadherin expression. Our results identify neuroserpin as a novel regulator of cell-cell adhesion and the synaptic adhesion molecule N-cadherin as a key effecter in this response. In nerve cells, neuroserpin may regulate the levels of N-cadherin available for construction, maintenance, and control of synapses and synaptic dynamics.
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Association of MCP-1 and CCR2 polymorphisms with the risk of late acute rejection after renal transplantation in Korean patients. Int J Immunogenet 2008; 35:25-31. [PMID: 18186797 PMCID: PMC2228509 DOI: 10.1111/j.1744-313x.2007.00725.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Among the factors modulating transplant rejection, chemokines and their respective receptors deserve special attention. Increased expression of monocyte chemoattractant protein-1 (MCP-1) and its corresponding receptor (chemokine receptor-2, CCR2) has been implicated in renal transplant rejection. To determine the impact of the MCP-1-2518G and CCR2-64I genotypes on renal allograft function, 167 Korean patients who underwent transplantation over a 25-year period were evaluated. Genomic DNA was genotyped using polymerase chain reaction followed by restriction fragment length polymorphism analysis. Fifty-five (32.9%) patients were homozygous for the MCP-1-2518G polymorphism. Nine (5.4%) patients were homozygous for the CCR2-64I polymorphism. None of the investigated polymorphism showed a significant shift in long-term allograft survival. However, a significant increase was noted for the risk of late acute rejection in recipients who were homozygous for the MCP-1-2518G polymorphism (OR, 2.600; 95% CI, 1.125–6.012; P = 0.022). There was also an association between the MCP-1-2518G/G genotype and the number of late acute rejection episodes (P = 0.024). Although there was no difference in the incidence of rejection among recipients stratified by the CCR2-V64I genotype, recipients with the CCR2-V64I GG genotype in combination with the MCP-1-2518G/G genotype had a significantly higher risk of acute or late acute rejection among the receptor-ligand combinations (P = 0.006, P = 0.008, respectively). The MCP-1 variant may be a marker for risk of late acute rejection in Korean patients.
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Audit on cardiovascular disease preventive care in general practice. Singapore Med J 2008; 49:311-315. [PMID: 18418523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
INTRODUCTION Cardiovascular disease is a major cause of morbidity and mortality. Primary care doctors as general practitioners (GPs) play a central role in prevention, as they are in contact with a large number of patients in the community through provision of first contact, comprehensive and continuing care. This study aims to assess the adequacy of cardiovascular disease preventive care in general practice through a medical audit. METHODS Nine GPs in Malaysia did a retrospective audit on the records of patients, aged 45 years and above, who attended the clinics in June 2005. The adequacy of cardiovascular disease preventive care was assessed using agreed criteria and standards. RESULTS Standards achieved included blood pressure recording (92.4 percent), blood sugar screening (72.7 percent) and attaining the latest blood pressure of equal or less than 140/90 mmHg in hypertensive patients (71.3 percent). Achieved standards ranged from 11.1 percent to 66.7 percent in the maintenance of hypertension and diabetic registries, recording of smoking status, height and weight, screening of lipid profile and attaining target blood sugar levels in diabetics. CONCLUSIONS In the nine general practice clinics audited, targets were achieved in three out of ten indicators of cardiovascular preventive care. There were vast differences among individual clinics.
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Abstract
The name astrovirus was used by Madeley and Cosgrove in 1975 to describe a small round virus (approximately 28 nm diameter) with star-like appearance on electron microscopy. It was first seen in faeces from a few children with gastroenteritis. An aetiological role in gastroenteritis has since been confirmed. The virus causes a mild illness after an incubation period of 3-4 days. Antibody studies indicate that infection is widespread and, in Britain, mainly occurs in the 2-5 year age group. Outbreaks occur in, for example, institutions and paediatric wards. The virus usually spreads by the faecal-oral route but food- or water-borne outbreaks have occurred. Strains of astrovirus have been isolated from many animals including calf, lamb, pig, cat, dog, duck and turkey. The lamb strain can cause gastroenteritis but the bovine strain did not cause diarrhoea in gnotobiotic calves. Infected turkeys have scours, and infection in ducklings causes haemorrhagic hepatitis with a mortality up to 25%. Five human serotypes have been described, all antigenically distinct from the bovine and ovine strains. The human astrovirus does not replicate in conventional tissue cultures but undergoes a non-productive cycle in human embryo kidney cells, and productive replication in the presence of trypsin. It is a positive-strand RNA virus, which is acid stable (pH3), survives at 60 degrees C for five but not 10 minutes and, like the enteroviruses, resists inactivation by alcohols. It has a density of 1.35-1.37 g/ml in caesium chloride.
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Dynamic evaluation of [18F]-FDG uptake in the rat brain by microPET imaging. CONFERENCE PROCEEDINGS : ... ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL CONFERENCE 2007; 2004:4461-4. [PMID: 17271296 DOI: 10.1109/iembs.2004.1404240] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
This study aims to acquire the functional image of the rat brain, small animal positron emission tomography (microPET) with high resolution and sensitivity is adopted to assess the metabolic activity corresponding to the neuronal activity induced by the electrical stimulation of the rat tail using [18F] fluorodeoxyglucose (FDG) as the radiotracer. The microPET imaging technology can provide anatomical and functional information on neuronal activity used to analyze responses in pathway sequence relationships between the thalamus and the cerebral cortex.
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Intercostal nerve blockade for cancer pain: effectiveness and selection of patients. Hong Kong Med J 2007; 13:266-70. [PMID: 17664531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2023] Open
Abstract
OBJECTIVES To review treatment results of intercostal nerve blockade at our centre and those reported in the literature, and to determine which patients benefit most from this procedure. DESIGN Retrospective study. SETTING Regional palliative care centre in a regional hospital in Hong Kong. PATIENTS Oncology patients who had intercostal nerve blockade at Tuen Mun Hospital from 1995 to 2005 were divided into three groups: (1) those who appeared not to tolerate opioids; (2) those deemed to have inadequate pain control, despite high doses of analgesics; and (3) those referred to avoid early use of high-dose opioids and tolerance. MAIN OUTCOME MEASURES The effectiveness and complications of intercostal nerve blockade, and the extent of benefit derived from intercostal nerve blockade in different patient groups. RESULTS This study found that 80% of the 25 patients noted optimal local pain control and 56% experienced reduction in analgesic use after intercostal nerve blockade. About 32% did not notice recurrence of the targeted pain till the end of their lives. None of the patients developed pneumothorax. Most benefit from intercostal nerve blocks were derived by group 2 patients, 90% of whom obtained optimal local pain control (P=0.23) and enjoyed a significant reduction in analgesics use (P=0.019), and in 40% their target pain was controlled till the end of life. Only about one third of group 3 patients had subsequent reduction in use of analgesics, mainly because they had co-existing pain other than at the target selected for treatment. Half (50%) of group 1 patients achieved optimal pain control. CONCLUSION Our treatment results from intercostal nerve blockade are comparable to those reported in the literature. The procedure is safe if closely monitored. Good selection of cases is important for optimising the therapeutic gain. The largest benefit is obtained in patients who have inadequate pain control after high-dose morphine.
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Management of Retrosternal Goitre with Superior Vena Cava Obstruction. Heart Lung Circ 2007; 16:312-4. [PMID: 17442618 DOI: 10.1016/j.hlc.2006.07.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2006] [Revised: 06/25/2006] [Accepted: 07/10/2006] [Indexed: 11/19/2022]
Abstract
Acute respiratory and cardiovascular decompensation secondary to retrosternal goitre is uncommon but life threatening. We report our experience of successful surgical management of a patient who presented acute enlargement of the mediastinal component of retrosternal goitre, which resulted in tracheal and vena cava compression.
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Expression of the serine protease inhibitor neuroserpin in cells of the human myeloid lineage. Thromb Haemost 2007; 97:394-9. [PMID: 17334506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Myeloid progenitors in the bone marrow differentiate into most of the major cell types of the immune system, including macrophages and dendritic cells. These cells play important roles in both innate and adaptive immunity. They express a number of proteases and protease inhibitors including members of the serine proteinase inhibitor or serpin superfamily. In this study we report the differential expression of neuroserpin in cells of the human myeloid lineage. Neuroserpin was highly expressed and secreted following the differentiation of monocytes to macrophages and dendritic cells. Activation of dendritic cells with lipopolysaccharide resulted in increased neuroserpin mRNA levels but no neuroserpin secretion. Confocal immunofluorescence microscopy showed neuroserpin was differentially localised in human myeloid cells. In macrophages and dendritic cells it was concentrated in vesicles located in close proximity to the plasma membrane. The majority of activated dendritic cells also exhibited an intracellular focal concentration of neuroserpin which co-localised with the lysosomal/late endosomal marker LAMP-1. As neuroserpin inhibits tissue plasminogen activator, a comparative analysis of tPA and plasminogen activator inhibitor-1 (PAI-1) expression was undertaken. This analysis revealed differential expression of PAI-1 and neuroserpin suggesting they may have different functions in human immune cells.
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Video assisted thoracic surgery in the management of spontaneous pneumothorax: the current status. Postgrad Med J 2006; 82:179-85. [PMID: 16517799 PMCID: PMC2563704 DOI: 10.1136/pgmj.2005.038398] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Over the past decade, video assisted thoracic surgery (VATS) has changed the way spontaneous pneumothorax (SP) is managed. Benefits of VATS include less postoperative pain, shorter hospital stay, and attenuated postoperative inflammatory response are evident compared with open thoracic procedures. Furthermore, the increasing acceptance by patients and referring physicians is testament to its success. Recent studies and the authors decade of experience in management of SP by VATS show that it is quick, safe, and effective, with recurrence rates generally comparable to open procedures, with some exceptions. However, selecting the correct procedure and patient, as well as knowing the limitations of the surgeons and techniques are paramount for success. Even to this day, there are considerable variations in the treatment of SP and large scale controlled studies are needed to better define timing of surgery and the role of the different procedures in the treatment and prevention of SP.
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Audit of hypertension in general practice. THE MEDICAL JOURNAL OF MALAYSIA 2005; 60:475-82. [PMID: 16570710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
An audit of hypertension management was done in October 2004 in nine general practice (GP) clinics. Two structure, ten process and two outcome indicators were assessed. Results showed that targets were achieved in only four indicators, i.e., weight recording (89%), BP monitoring (85.8%), follow-up interval not exceeding 6 months (87.9%) and mean diastolic BP (73.9%). The other indicators (hypertension registry, reminder mechanisms for defaulters, recording of smoking, height, fundoscopy, monitoring of lipid profile, blood sugar, ECG, renal function and achievement of target mean systolic pressure) showed adequacy percentages varying from 22.1 to 68.7. Out of the 1260 patients assessed, 743 (59%) achieved a mean BP < or = 140/90 (or < or = 130/80 mmHg with diabetes mellitus / renal insufficiency) in the last 3 recorded readings. There was a vast difference between individual clinics. Reasons for not achieving targets were discussed and remedial measures for implementation were recommended.
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Abstract
Severe acute respiratory syndrome (SARS) is an emerging infectious disease with both pulmonary and extra-pulmonary manifestations. Although coagulation abnormalities are common in these patients, clinically overt thromboembolic events are rarely reported. This report describes the first case of pulmonary artery thrombosis in a patient with laboratory confirmed SARS.
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Iatrogenic causes of hilar radiopaque densities. Eur Respir J 2005; 26:358. [PMID: 16055886 DOI: 10.1183/09031936.05.00038305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Abstract
Thoracic procedures are considered to be among the most painful surgical incisions and are associated with considerable postoperative pain and shoulder dysfunction, severely affecting mobility and activities of daily living. Improper patient positioning, muscle division, perioperative nerve injury, rib spreading, and consequent postoperative pain influence the patient's postoperative shoulder function and quality of life. To reduce access trauma and postoperative morbidity, various alternative modalities have been proposed to replace the standard PLT, including muscle-sparing techniques and VATS. Initial evaluations suggest that these alternatives are associated with significantly better postoperative shoulder function. Proper comparative studies using standardized questionnaires, objective evaluations, or quality-of-life assessments are scarce, however. Proper postoperative care, including early mobilization and effective physiotherapy, is a cornerstone in successful patient rehabilitation and rapid return to normal daily activities. Whether upper extremity exercises can contribute to improvement in postoperative shoulder function and the ability to perform activities of daily living needs to be studied further.
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Audit of diabetes mellitus in general practice. THE MEDICAL JOURNAL OF MALAYSIA 2004; 59:317-22. [PMID: 15727376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Abstract
An audit on diabetic management was done in seven Perak general practice (GP) clinics in December 2001. The results showed inadequacies in nine out of eleven criteria assessed. Remedial measures were implemented. A second audit in March 2003, at the completion of the audit cycle, showed improvements in all the criteria used. All clinics established a diabetic register compared to 28.6% in the first audit and 57.1% of the clinics set up a reminder mechanism compared to 0% in the first audit. In the process of care, recording of weight, height, blood pressure; feet examination, fundoscopy, blood sugar monitoring and urine for albumin improved at the end of the audit cycle. In the only outcome criteria, the blood sugar control improved from 21.8% to 31.3%.
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Abstract
Lung cancer continues to be the most common cancer in the world, with the highest cancer mortality rate by far. Although resection remains the treatment of choice in early-stage NSCLC, the prognosis remains grim even after surgical treatment. In a patient population with such a high mortality rate, evaluation and preservation of QOL after treatment is imperative. Early-stage lung cancer patients already have significantly lower QOL when compared with the normal population before surgical treatment, with significant impairment in physical and emotional functioning. Lung cancer resection causes further deterioration of QOL, especially in the first 3 to 6 months after surgery. While some studies suggest that QOL returns to baseline levels at 6 to 9 months postoperatively, others report that QOL is still significantly impaired at 6 months and 1 year after surgery. Although prospective studies analyzing long-term postoperative QOL are not available, retrospective data suggest that long-term survivors after lung cancer surgery enjoy good QOL despite impaired physical functioning. QOL studies on VATS lung cancer resection are extremely limited. More prospective, longitudinal studies with larger study populations and longer follow-up periods are needed to portray the course of QOL in lung cancer patients more accurately and to improve postoperative care. Furthermore, comparative studies between VATS and the standard thoracic incisions (including QOL assessments) must be performed to guide clinical decision making regarding selection of optimal access modality for performing lung cancer resection.
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Abstract
During double-lumen tube (DLT) placement, the anesthesiologist must be mindful of the margin of safety. We determined how this margin is affected by the presence of a tracheal bronchus by elucidating the mathematical relationship between some relevant physical dimensions of the trachea, bronchi, and DLT. Our results suggest that a tracheal bronchus only rarely affects the intrinsic margin of safety of DLT placement. When the tracheal bronchus is located much higher than its most frequently seen location (within 2 cm from the carina), however, there is increased risk that it could be blocked by the tracheal cuff of a left-sided DLT.
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Current indications and results of VATS in the evaluation and management of hemodynamically stable thoracic injuries. Eur J Cardiothorac Surg 2004; 25:1048-53. [PMID: 15145008 DOI: 10.1016/j.ejcts.2004.02.017] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2003] [Revised: 02/12/2004] [Accepted: 02/16/2004] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVE Thoracic injuries are among the most severe forms of trauma and also a leading cause of morbidity and mortality. Video Assisted Thoracic Surgery (VATS) has recently provided an alternative method to simultaneously diagnose and manage patients sustaining chest injuries. We analyze our experience with VATS in the setting of thoracic trauma detailing indications for exploration, procedures performed and results of surgery. METHODS A 6-year single institution review of patients undergoing VATS due to injuries sustained from both blunt and penetrating chest trauma at a Level I trauma center and university teaching hospital. Comparisons were made between groups of blunt and penetrating trauma as to Injury Severity Score (ISS), presence of extra-thoracic injuries, initial thoracostomy drainage and length of postoperative stay. RESULTS VATS was successfully performed in 19 consecutive patients without conversion to thoracotomy. Indications for exploration included acute hemorrhage, retained hemothorax, suspected diaphragmatic injuries (DI), suspected cardiac injury, intra-thoracic foreign body, persistent airleak and chronic empyema. Procedures performed consisted of evacuation of retained hemothorax, hemostasis of intra-thoracic bleeders, repair of DI, wedge lung resections and decortication. Mean postoperative length of stay was 5.86 days. There were no morbidities. One patient with severe intra-abdominal injuries expired on the first postoperative day. CONCLUSION In hemodynamically stable patients with thoracic injuries, VATS provides an accurate assessment of intra-thoracic organ injury and can be utilized to definitively and effectively manage injuries sustained as a result of blunt or penetrating thoracic trauma. VATS should be used with caution in patients sustaining severe and life threatening intra-abdominal injuries.
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Abstract
Synovial sarcomas are uncommon soft tissue tumours. Immunohistochemistry and cytogenetic techniques are essential for proper diagnosis and differentiation from other spindle cell neoplasms. A case of mediastinal synovial sarcoma is described, of which the unusual location, diagnosis and treatment form the basis of this report.
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The impact of thoracic surgical access on early shoulder function: video-assisted thoracic surgery versus posterolateral thoracotomy. Eur J Cardiothorac Surg 2003; 23:390-6. [PMID: 12614812 DOI: 10.1016/s1010-7940(02)00795-9] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
OBJECTIVE Whether video-assisted thoracic surgery (VATS) is associated with less shoulder dysfunction when compared with posterolateral thoracotomy (PLT) remains unclear. We therefore conducted this prospective study to assess the shoulder function in patients following major lung resection using either the VATS or PLT approach. METHODS Twenty-nine consecutive patients were prospectively recruited into the study. Eighteen patients underwent major lung resection through VATS (VATS group) and 11 patients through PLT (open group). Shoulder function was measured preoperatively, and postoperatively at 1 week, 1 month and at 3 months. All assessments were done by two experienced physiotherapists using the American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form. RESULTS Shoulder strength was significantly better preserved in the VATS group at 1 week after surgery when compared with the PLT group (92 versus 81% of preoperative value; P=0.024). VATS patients also had better range of motion especially with respect to external rotation at 1 week (98 versus 91%; P=0.015) and forward elevation at 1 month (98 versus 93%; P=0.024) and 3 months after surgery (100 versus 96%; P=0.021). Analgesic requirement was significantly less in the VATS group postoperatively at 1 week (P=0.009) and 1 month (P=0.004). CONCLUSIONS VATS major lung resection is associated with significantly less shoulder dysfunction and pain medication requirement in the early postoperative period when compared to the PLT approach.
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Radioimmunodetection of cervical carcinoma xenografts with (111)In-labeled MAb Cx-99 detected by a hand-held gamma detector. EUR J GYNAECOL ONCOL 2002; 23:178-82. [PMID: 12094949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
PURPOSE To establish a radioimmunodetection (RAID) system for localization of cervical cancer by labeling 111-indium ((111)In) to a monoclonal antibody against cytokeratin 19 (MAb Cx-99), and detecting it with a hand-held gamma detector in an animal model. METHODS MAb Cx-99 was labeled with 111-Indium by the DTPA chelating method. From the second day to the seventh day after injection of this immunoconjugate into athymic nude mice bearing cervical cancer cell line CC7T xenografts, the biodistribution ratios of tumor and non-tumor radioactivity were detected by a hand-held gamma detector. Data were also correlated with the data detected by the conventional gamma counter. RESULTS The labeling efficiency of this (111)In-labeled MAb Cx-99 and (111)In-labeled MOPC was 91.6% and 95.5%, respectively. After injection, the liver, kidney and lung were initially noticed to have high radioactivity, but the localization of tumor/tissue ratios increased progressively as time passed, indicating the effect of delayed detection for distinguishing tumor from non-tumor tissues. Except for the spleen, the range of tumor/tissue ratios was 1.18-32.7 and 1.14-39.35 for the fourth day and the seventh day, respectively. The tumor/spleen ratio remained low until the seventh day after injection, thus indicating that the spleen might have a different excretion rate. CONCLUSION This study indicated the feasibility of a hand-held detection system in the localization of cervical cancer after injection of (111)In-labeled MAb Cx-99. The effect of delayed detection was obvious by the decreasing high bindings in the liver, spleen and kidney, with the applicable detection time being four to seven days after injection.
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A simple maneuver to detect air leaks on the operating table after needlescopic video-assisted thoracic surgery. J Thorac Cardiovasc Surg 2002; 124:1029-30. [PMID: 12407391 DOI: 10.1067/mtc.2002.125650] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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Abstract
STUDY OBJECTIVES Quality of life (QOL) following video-assisted thoracic surgery (VATS) major lung resection has not been systematically studied. This study was designed to evaluate the intermediate to long-term QOL in patients with lung cancer following resection, comparing VATS with thoracotomy. DESIGN Cross-sectional study, telephone survey. METHODS Of 136 disease-free surviving patients with non-small cell lung cancer operated on between 1994 and 2000, 45 patients were excluded because of large tumors (> 5 cm) or locally advanced disease, and another 27 patients were excluded because of adjuvant therapy, coexisting cancer from another source, or psychiatric illness. At the time of the survey, 13 patients were found to be either unsuitable or unwilling to participate. This left a total of 51 patients, with 27 patients in the VATS group and 24 patients in the thoracotomy group (open group), for the final analysis. QOL was assessed using Chinese versions of the European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire (QLQ)-C30 and the EORTC QLQ-LC13, supplemented with nine self-developed surgery-related questions. RESULTS Mean follow-up time was 33.5 months in the VATS group (median, 20.8 months; range, 6.0 to 84.2 months) and 39.4 months in the open group (median, 37.7 months; range, 7.0 to 75.1 months). Both groups had good QOL and high levels of functioning despite a fairly high incidence of symptoms. There was a trend for VATS patients to score higher on the QOL and functioning scales and to report fewer symptoms. However, these differences did not lead to statistical significance. CONCLUSIONS This study showed that lung cancer patients with resectable disease following surgical treatment without recurrence have good QOL and high levels of functioning on intermediate to long-term follow-up, with no significant differences between the VATS and open groups.
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Video-assisted thoracic surgery for mediastinal extramedullary haematopoiesis. Ann R Coll Surg Engl 2002; 84:161-3. [PMID: 12092864 PMCID: PMC2503808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023] Open
Abstract
Extramedullary haematopoiesis is a rare cause of an intrathoracic mass. We report a case of posterior mediastinal extramedullary haematopoietic mass in a 50-year-old man who presented with non-specific symptoms and a paravertebral mass on chest X-ray. Diagnosis was achieved by using video-assisted thoracic surgery.
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