A Comparison of the P-POSSUM and NELA Risk Score for Patients Undergoing Emergency Laparotomy in Singapore.

BACKGROUND (AIMS, HYPOTHESES, OR OBJECTIVES): Emergency laparotomy (EL) is a high-risk surgical procedure associated with considerable morbidity and mortality around the world. A reliable risk-assessment tool that is specific to patients undergoing EL allows the early identification of high-risk patients and enables appropriate healthcare resource allocation. The objective of this study was to compare the commonly used Portsmouth-physiologic and operative severity score for the enumeration of mortality and morbidity (P-POSSUM) with the recently developed National Emergency Laparotomy Audit (NELA) score in terms of their accuracy for identifying patients at increased risk of 30-day mortality in a predominantly Asian population. METHODS: Physiological and operative data from a prospectively collected audit of adult patients undergoing EL in 2018 and 2019 across two tertiary hospitals in Singapore were used to retrospectively calculate both the P-POSSUM and NELA scores for each patient encounter. This was then compared to actual mortality rates to determine each model's accuracy and precision. RESULTS: 830 patients were included in the study with a 30-day mortality of 5.66%. The area under the receiver operating characteristics curve (AUROC) was similar for both the NELA (0.86, p < 0.001, 95% CI 0.81-0.91) and the P-POSSUM models (0.84, p < 0.001, 95% CI 0.78-0.89). While the models over-predicted mortality, overall O:E ratios showed that the NELA model performance was superior to that of P-POSSUM (0.58 [95% CI 0.43-0.77] compared to 0.34 [95% CI 0.26-0.46]). CONCLUSION: The NELA risk-prediction model accurately predicts 30-day mortality in this large cohort of patients undergoing EL and outperforms the current P-POSSUM model. We recommend that the NELA score should replace the P-POSSUM score as a model to distinguish between high- and low-risk patients undergoing EL.

Unusual acute promyelocytic leukemia following de novo renal transplant: case report and literature review.

Acute promyelocytic leukemia (APL) with transcripting three isoforms of mRNA from PML-RAR alpha fusion genes following renal transplantation has never been reported in the literature. A 39-year-old man received a cadaveric renal allograft for IgA chronic kidney disease in 2006 and was consecutively immunosuppressed by tacrolimus, mycophenolate mofetil, and prednisolone. In 2008, he presented with gum bleeding and weight loss. Following bone marrow biopsy, we diagnosed acute promyelocytic leukemia. Molecular analysis demonstrated atypical presence consisting of three isoforms of mRNA from PML-RAR alpha fusion genes. The patient was administered with three courses of consolidation chemotherapy plus atretinoin, resulting in complete remission and did not jeopardize his allograft function. This novel finding suggests that the leukemogenesis of APL may be polyclonal, sharing similar progenitor targeting on complicated karyotypes, responding well to current chemotherapy.

Pannexin2 as a novel growth regulator in C6 glioma cells.

Connexins (Cxs), the gap junction proteins, have been found to be downregulated in many types of cancers including gliomas. By restoring gap junctional communication in cancer cell models, the neoplastic phenotype can be reversed, suggesting Cxs are tumor suppressors. Pannexin2 (Panx2) is a member of the novel gap junction protein family, Panxs, and it has been proposed as a brain-specific protein. Recently, gene array analysis showed an overall reduction of Panx2 in gliomas, and a direct correlation was observed between Panx2 expression and post-diagnosis survival in patients. In this study, we explored the potential inverse correlation between Panx2 and glioma oncogenicity. A decrease or absence of Panx2 expression in a panel of human glioma cell lines was found, whereas an appreciable amount of Panx2 was detected in both human brain and astrocytes. Stable Panx2 expression revealed a flattened morphology and increased cell-cell contacts in rat C6 glioma cells similar to Panx1. However, in contrast to Panx1 and Panx3, Panx2 was predominately detected in the cytoplasm in vesicle-like patterns but not at the plasma membrane. Coexpression of Panx2 and Panx1 did not show colocalization of both Panxs. Strikingly, restoration of Panx2 expression significantly reduced in vitro oncogenicity parameters, including monolayer saturation density and anchorage-independent growth, as well as in vivo tumor growth. This study suggests a role of aberrant Panx2 expression during gliomagenesis, and that Panx2 independently functions as a negative growth regulator without Panx1.

Connexin 43 hemichannels contribute to the propagation of apoptotic cell death in a rat C6 glioma cell model.

Gap junctions (GJs) have been demonstrated to communicate cell death signals from apoptotic to healthy cells, thereby spatially extending apoptosis. Before being incorporated into GJs, hemichannels (hemi-GJs) are normally closed but recent evidence suggests that they can be opened by various messengers and conditions, thereby forming a pore through which molecules can enter or leave the cell potentially leading to cell death. The aim of this study was to determine the contribution of GJs and hemichannels in the communication of apoptosis toward surrounding cells. We induced apoptosis in C6 glioma cells stably transfected with connexin (Cx)43, with cytochrome C (cytC) using in situ electroporation and found that healthy surrounding cells underwent apoptotic transformation. Work with various cell death markers, wild-type (WT) and Cx43-expressing cells, inhibitors of GJs and/or hemichannels, and Cx43 gene silencing showed that GJs contribute to the spread of apoptosis in a zone next to where apoptosis was triggered whereas hemichannels also promoted cell death beyond this area. Buffering cytoplasmic Ca(2+) changes inhibited the spread of apoptosis in both cases. We conclude that Cx43 hemichannels, in concert with their GJ counterparts, play a role in communicating cytC-induced apoptotic cell death messages.

Morphology and properties of denture acrylic resins cured by microwave energy and conventional water bath.

OBJECTIVES: This study examined the influence of microwave energy levels on the morphology and properties of an impact resistant denture material poly(methyl methacrylate) with a thickness of 10 mm. METHODS: A microwave flask containing two resin blocks was processed at 80, 160, 240, and 560 W for 15, 10, 7, and 2 min, separately. Each Flask was then turned over, and cured for an additional 2 min at 560 W. The process using conventional methods was carried out at 70 degrees C for 9 h. The blocks were tested for hardness, porosity, flexural properties, solubility, and molecular weight. The morphology of the specimens after staining with osmium tetroxide was examined by transmission electron microscope. RESULTS: The changes in temperature with time were recorded during microwave heating at 80, 160, and 240 W, respectively. A significantly large difference in the curing temperature was observed when comparing these two processing methods. There was little difference in the mean values of surface hardness and the weight percent of the insoluble parts. The mean domain size and the volume fraction of the rubber phase favor of the water-bath method. However, the porosity in the water-bath-cured specimens was much less than that in the microwave-cured specimens. Thus, the conventionally cured specimens showed better flexural strength and flexural modulus than the microwave-cured specimens. SIGNIFICANCE: This study has shown that microwave energy can efficiently polymerize denture base polymer. Highly statistical differences in morphology and flexural properties favor of the water-bath method. Choice of a suitable microwave power and polymerization time is important in order to reduce porosity to a minimum level and increase the domain size and volume of the rubber phase.

Constrictive pericarditis associated with Marlex mesh. Two case reports.

Two patients were referred to our hospital with constrictive pericarditis approximately 1 year after undergoing mitral valve repair at another institution. Both repairs had included the use of a pericardial substitute, Marlex mesh, to prevent adhesion and to facilitate possible reoperations. Computed tomography and cardiac catheterization were used to establish the diagnosis of constrictive pericarditis. During surgery, dense, thickened fibrous tissue, the result of a Marlex mesh-related reaction, was found tightly adhered to the epicardium in each of the patients. It appeared that the Marlex mesh, which had been inserted to facilitate reoperation, had contributed to the development of constrictive pericarditis.

Non-competitive inhibition of 5-HT3 receptor-mediated currents by progesterone in rat nodose ganglion neurons.

The effect of progesterone on the serotonin type 3 (5-HT3) receptor-mediated response was studied in acutely dissociated rat nodose ganglion neurons by using the whole-cell voltage-clamp technique. Progesterone rapidly and reversibly inhibited 5-HT-induced currents in a dose-dependent manner, with an EC50 of 31 microM and a maximal inhibition of 75%. Neither the 5-HT response nor inhibition of the 5-HT response by extracellularly applied progesterone was significantly affected by inclusion of a saturating concentration of progesterone in the electrode buffer, arguing that progesterone acted at the extracellular surface of the membrane. Progesterone also inhibited the 5-HT response non-competitively by a voltage- and agonist-independent mechanism that was distinct from that of open-channel blockers.

Delayed onset of amaurosis fugax in a patient with type A aortic dissection post surgical repair.

Stroke is an important complication for the surgical treatment of type A aortic dissection and it occurs immediately post operation. Many surgical techniques such as deep hypothermic circulatory arrest and retrograde cerebral perfusion have been reported to ameliorate this complication. We report here a male Taiwanese patient with type A aortic dissection involving the arch who underwent surgical repair. Amaurosis fugax appeared on the 4th day post operation. Funduscopic findings demonstrated multi focal embolization and carotid sonography revealed normal carotid arteries. The symptoms and signs improved after anticoagulation therapy. This is a rare case of delayed onset of amaurosis fugax in a patient with type A aortic dissection post surgical repair. The thromboemboli might have originated from the internal surface of the sawing area.

Cardiogenic shock in a patient with glyphosate-surfactant poisoning.

We present a case of glyphosate-induced cardiogenic shock in a young man. The patient a 26-year-old man, presented with nausea and vomiting 4 hours after attempting suicide by drinking 150 mL of glyphosate surfactant. Cardiogenic shock with accelerated idio-ventricular rhythm on electrocardiography developed after admission. Intravenous injection of epinephrine, atropine, and calcium failed to improve the condition. Over the next 16 hours, the QRS complex gradually narrowed, sinus rhythm returned, and the hemodynamic status improved. Echocardiograms revealed diffuse left ventricular hypokinesis with markedly reduced ejection fraction while the patient was in shock; normal left ventricular function resumed the next day. In this case, the glyphosate surfactant poisoning-induced shock may have been due to transient suppression of the cardiac conduction system and contractility, rather than intravascular hypovolemia.

Evaluation of the early stage of carotid atherosclerosis using the vascular response to nitroglycerin and high-resolution ultrasonography.

The purpose of this study was to determine whether the early stages of arterial atherosclerosis could be evaluated by the vascular response to nitroglycerin (NTG). The vascular elasticity of the common carotid artery (CCA) was evaluated at sites without atheromatous plaque using high-resolution ultrasonography before and after sublingular NTG administration. The vascular elasticity was expressed by vascular strain (VS) and pressure-strain elastic modulus (Ep). The study was performed in 9 normal young males (group N) and 52 patients who were suspected to have coronary artery disease (CAD). In group N, VS of the CCA increased from 9+/-2 to 13+/-4%, Ep decreased from 80+/-18 to 42+/-14 kPa (p<0.01) and systolic blood pressure (SBP) decreased from 116+/-8 to 109+/-8 mmHg (p<0.05) after NTG administration. Two different responses were observed in the patients. One group of patients (group A, n=27) showed similar responses to NTG as those of group N; that is, VS increased from 8+/-4 to 14+/-8%, Ep decreased from 115+/-64 to 57+/-31 kPa (p<0.01) and SBP decreased from 121+/-15 to 110+/-16 mmHg (p<0.05). In the other group (group B, n=25), in spite of SBP decreasing from 124+/-21 to 111+/-21 mmHg (p<0.05), VS decreased from 11+/-4 to 7+/-3% and Ep increased from 76+/-29 to 113+/-53 kPa (p<0.01). The prevalence and severity of CAD were lower in group A than in group B (33 vs 80%, 11 vs 60%, p<0.01, respectively). The prevalence of atheromatous plaque of the CCA was also lower in group A than in group B (4 vs 22%, p<0.01). These results revealed that the prevalence of carotid atheromatous plaque was highly correlated with that of CAD (p=0.001) and suggested that the vascular elasticity response of the CCA to NTG is highly associated with atherosclerotic changes of the artery and may be a useful method for detecting the early stages of atherosclerosis.

The effect of morphology variety of EVAL membranes on the behavior of myoblasts in vitro.

Not only the surface morphology but also the surface chemistry can be changed during the fabrication of biomaterials. Therefore, the result of a biocompatibility test of one material may alter to a great extent, dependent on the fabrication process. In this paper, the in vitro interaction of myoblasts and EVAL membranes with different surface properties was investigated. It was observed that moderate contact angle and porous structure are favourable for the cell adhesion and growth. However, cell adhesion and growth were decreased on a porous structure with particulate morphology and higher contact angle.

Risk factors associated with coronary artery stenosis among patients with chest pain in eastern Taiwan.

To analyze the risk factors for coronary artery stenosis among patients who were admitted to the hospital with chest pain in eastern Taiwan, we retrospectively reviewed the clinical data of 444 patients who received coronary arteriography, including 62 aborigines. Results indicated that there were 268 patients (64%) with coronary stenosis. Male to female ratio, mean age, pack-years of cigarette smoking, and hypertension were significantly higher in patients with coronary stenosis (CS group) than in patients without coronary stenosis (control group). There were also significant differences in the serum levels of total cholesterol, low-density lipoprotein cholesterol and high-density lipoprotein cholesterol between the CS and control groups. The total cholesterol and low-density lipoprotein cholesterol of both the CS and control groups were lower than those reported in western Taiwan. The prevalence of coronary stenosis among Taiwanese patients who presented with chest pain was significantly higher than in aborigines (64% vs 38%), although there were no significant differences in common risk factors between these two ethnic groups. These results revealed that the common risk factors in eastern Taiwan were the same as those reported here and suggest that race may be an important risk factor for coronary stenosis.

Klebsiella pneumoniae-induced mycotic aneurysm of the abdominal aorta complicated by bloody pleural effusion--a case report.

A 68-year-old diabetic male who suffered from recurrent severe lumbago and high fever was found to have mycotic abdominal aneurysm. His symptoms did not improve after maximum-dose antibiotic therapy. Bloody pleural effusion on the left side was noticed hours before he expired. Klebsiella pneumoniae alone was isolated from blood from cellulitis-related bacteremia, when aneurysm formation was complete and later from bloody pleural effusion. To our knowledge, this is the first report of mycotic abdominal aneurysm of solely Klebsiella pneumoniae complicated by bloody pleural effusion.

Beneficial effects of atrial natriuretic peptide on exercise-induced myocardial ischemia in patients with stable effort angina pectoris.

BACKGROUND: It has been shown that atrial natriuretic peptide (ANP), an endogenous vasodilator, dilates coronary arteries and decreases coronary vascular resistance. The purpose of this study was to determine whether an intravenous administration of ANP attenuated exercise-induced myocardial ischemia in 14 patients with stable effort angina pectoris. METHODS AND RESULTS: The first 12 patients (patients 1-12) who had exercise-induced ST segment depression underwent treadmill exercise testing and the last seven patients (patients 8-14) underwent the exercise 201Tl-single-photon emission computed tomography (SPECT) study while synthetic 28-amino acid alpha-human ANP (0.1 micrograms/kg per minute) or saline was intravenously infused in a double-blind, cross-over manner. The duration of exercise testing was the same during ANP and saline infusion, which was determined in preliminary exercise testings in each patient to cause a transient perfusion defect and/or ischemic ST segment depression. During saline infusion, all 12 patients developed exercise-induced ischemic ST segment depression, whereas no significant ST segment depression appeared during ANP infusion. Average ST segment depression during ANP infusion was significantly less (p < 0.01) than that during saline infusion (0.0 +/- 0.0 versus 0.2 +/- 0.1 mV, mean +/- SD). The averaged extent and severity scores assessed by 201Tl-SPECT were smaller (p < 0.05) during ANP infusion than during saline infusion (extent score: 0.22 +/- 0.20 versus 0.42 +/- 0.20; severity score: 18.77 +/- 23.45 versus 38.24 +/- 24.04, respectively). ANP decreased resting systolic blood pressure from 125 +/- 15 to 110 +/- 15 mm Hg (p < 0.01) but did not alter resting heart rate. At peak exercise, systolic blood pressure, heart rate, and the rate-pressure products did not differ during ANP and saline infusion. At peak exercise, plasma ANP increased from 98 +/- 45 to 4,383 +/- 2,782 pg/ml and cGMP increased from 3.6 +/- 1.7 to 34.5 +/- 16.1 pmol/ml during ANP infusion; values were significantly higher than those during saline infusion (from 96 +/- 42 to 133 +/- 66 pg/ml and from 3.4 +/- 1.8 to 4.6 +/- 1.8 pmol/ml, respectively). CONCLUSIONS: An intravenous administration of ANP attenuated exercise-induced myocardial ischemia in patients with stable effort angina pectoris. Although the mechanism by which ANP attenuated myocardial ischemia was not defined, increased myocardial perfusion to the ischemic region might be an important factor.

Transesophageal echocardiographic findings of quadricuspid aortic valve.

We report a case of a 40-year-old man who had a quadricuspid aortic valve associated with aortic regurgitation. The anomaly was revealed by transesophageal echocardiography (TEE), and confirmed by cardiac surgery. TEE is a useful noninvasive method for identifying the quadricuspid aortic valve.