New iridium dopants forg white phosphorescent devices: enhancement of efficiency and color stability by an energy-harvesting layer

A new light blue complex (fmoppy)2Ir(tfpypz) [bis(4'-fluoro-6'-methoxylphenyl pyridinato)-iridium(III)-3-(trifluoromethyl)-5-(pyridin-2-yl)-1,2,4-triazolate] and a new orange complex (dpiq)2Ir(acac) [bis(3,4-diphenylisoquinoline)-iridium(III)-acetylacetonate] were synthesized. These two complexes were used as the dopants for the fabrication of two-element white phosphorescent devices. Via the introduction of a thin energy-harvesting layer (EHL) to harvest the extra energy and exciton from the emission zone, highly efficient two-element white devices with excellent color stability were created. One of the best devices shows yellow-white color emission with an extremely high external quantum efficiency (EQE) of 21.5% and a current efficiency of 68.8 cd/A. The other device gave a pure white emission with an external quantum efficiency of 19.2% and a current efficiency of 53.2 cd/A. At a high brightness of 1000 cd/m(2), the EQE still remains as high as 18.9 and 17.2%. With a brightness of 1000-10000 cd/m(2), the CIE coordinates of these two devices shift by only (0.02, ≤0.01). The white phosphorescent devices with the EHL showed much higher efficiency and better color stability than the one without the EHL.

Iodine-129 in seawater offshore Fukushima: distribution, inorganic speciation, sources, and budget

The Fukushima nuclear accident in March 2011 has released a large amount of radioactive pollutants to the environment. Of the pollutants, iodine-129 is a long-lived radionuclide and will remain in the environment for millions of years. This work first report levels and inorganic speciation of (129)I in seawater depth profiles collected offshore Fukushima in June 2011. Significantly elevated (129)I concentrations in surface water were observed with the highest (129)I/(127)I atomic ratio of 2.2 × 10(-9) in the surface seawater 40 km offshore Fukushima. Iodide was found as the dominant species of (129)I, while stable (127)I was mainly in iodate form, reflecting the fact that the major source of (129)I is the direct liquid discharges from the Fukushima NPP. The amount of (129)I directly discharged from the Fukushima Dai-ichi nuclear power plant to the sea was estimated to be 2.35 GBq, and about 1.09 GBq of (129)I released to the atmosphere from the accident was deposited in the sea offshore Fukushima. A total release of 8.06 GBq (or 1.2 kg) of (129)I from the Fukushima accident was estimated. These Fukushima-derived (129)I data provide necessary information for the investigation of water circulation and geochemical cycle of iodine in the northwestern Pacific Ocean in the future.

Validation of the behavior and concept based assessment of professionalism competence in postgraduate first-year residents

BACKGROUND

The evaluation of professional behaviors and concepts of postgraduate first-year (PGY1) residents has been identified as an area for development. This study examined the efficiency of the professionalism-assessing objective structured clinical examination (OSCE), 360° evaluation, and mini-Clinical Examination Exercise scores (mini-CEX; p-OSCE, p-360° evaluation, and p-mini-CEX scores).

METHODS

Between January 2009 and January 2012, 189 PGY1 residents were evaluated for behavior- and concept-based professionalism competence based on the above three methods using two checklists unique to each case. Data were analyzed for reliability, inter-rater agreement, interval changes, and gender-related difference for each method.

RESULTS

The test reliabilities of p-OSCE, p-360° evaluation, and p-mini-CEX were acceptable. Further, the reliability of concept and combined p-OSCE was higher than that of behavior p-OSCE. In addition, the concept OSCE p-scores and behavior 360° evaluation p-scores were significantly improved after 6 months of training. The inter-rater agreements were relatively good in p-OSCE and p-360° evaluation. Interestingly, male PGY1 residents had higher behavior 360° evaluation p-scores from nurses than those of females, whereas female PGY1 residents had higher behavior 360° evaluation p-scores from patients than those of males. Behavior and concept OSCE p-scores were positively correlated with behavior 360° evaluation p-scores. In comparison with p-360° evaluation, the combination of p-360° evaluation + OSCE + mini-CEX significantly increases their reliabilities.

CONCLUSION

The current study suggests that the p-OSCE, p-360° evaluation, and p-mini-CEX are feasible methods for evaluating professionalism in clinical training of PGY1 residents. Combination of the above three evaluations, participation, and support from multiple constituencies and multiple representatives provides good reliability and adds credibility in the assessment of professionalism competence.

Chronological changes in renal vascular reactivity in portal hypertensive rats

BACKGROUND

Circulatory dysfunction in portal hypertension is characterized by increased cardiac output, decreased systemic vascular resistance, a fall in mean arterial pressure secondary to splanchnic and systemic vasodilation and hence renal hypoperfusion. Previous studies have disclosed that renal vasculatures of portal hypertensive rats had lower perfusion pressure and hyporesponsiveness to endogenous vasoconstrictors. However, the sequences of altered renal haemodynamics have never been described. This study aimed to explore the evolution of renal vascular hyporeactivity and associated mechanisms during portal hypertension.

MATERIALS AND METHODS

All rats were randomized into partial portal vein ligation (PVL) or shamed surgery. Isolated kidney perfusion was performed at postoperative day 1, 4, 7 and 14, respectively, to evaluate chronologically renal vascular response to endothelin-1. Renal arteries and kidneys were harvested for further analysis.

RESULTS

Impaired renal vascular reactivity to endothelin-1 developed 1 week following PVL. There were extensive up-regulations of vasodilative nitric oxide synthase (NOS) and cyclooxygenase-2 in renal arteries of PVL rats. Among them, the changes in endothelial NOS paralleled with the evolution of renal vascular hyporesponsiveness. Preincubation of NOS inhibitor attenuated the renal vascular hyporeactivity in PVL rats. Up-regulated NOS and down-regulated cyclooxygenase-2 in kidneys of PVL rats might play a critical role to maintain renal circulation and body fluid homoeostasis in response to systemic hypotension.

CONCLUSIONS

This investigation highlights the versatile nature of renal vasculatures in portal hypertension, which is replete with compensatory mechanisms. It may help to unveil potential mechanisms of severe renal dysfunction in advanced liver disease.

Adverse postoperative outcomes in surgical patients with immune thrombocytopenia

Background

Patients with immune thrombocytopenia (ITP) are likely to have various medical co-morbidities, yet their global features regarding adverse postoperative outcomes and use of medical resources when undergoing major surgery are unknown. The objective of this study was to validate whether ITP is an independent risk factor for adverse postoperative outcomes, and to explore the potential clinical predictors of outcomes after major surgery among patients with ITP.

Methods

A retrospective population-based cohort study was conducted using Taiwan's National Health Insurance Research Database, controlling for preoperative co-morbidities by means of multiple logistic regression. Major postoperative complication and mortality rates, and in-hospital medical costs were analysed.

Results

The study included 11 085 surgical patients with ITP and 44 340 controls without ITP matched for sex, age, and type of surgery and anaesthesia. Surgical patients with ITP had a higher risk of postoperative death (odds ratio (OR) 1·89, 95 per cent confidence interval 1·57 to 2·27), and overall postoperative complications (OR 1·47, 1·39 to 1·56), and increased hospital stay (OR 1·90, 1·80 to 2·01), admission to the intensive care unit (OR 1·73, 1·63 to 1·83) and medical costs (OR 1·89, 1·79 to 1·99). Amount of preoperative platelet and/or red blood cell transfusion, emergency visits and admission to hospital for ITP care were identified as risk factors for adverse postoperative outcomes.

Conclusion

Patients with ITP undergoing surgery are at increased risk of adverse perioperative events, particularly if blood or blood product transfusion are required preoperatively, or the procedure is done as an emergency.

The influence of sorafenib on hepatic encephalopathy and the mechanistic survey in cirrhotic rats

BACKGROUND

Sorafenib, a multikinase inhibitor that inhibits angiogenesis and carcinogenesis, has been used for patients with advanced hepatocellular carcinoma. However, sporadic cases have been reported with the development of hepatic encephalopathy (HE) after sorafenib treatment, mostly in those with cirrhosis. Liver function impairment, portal-systemic collaterals and brain oxidative stress participate in the pathogenesis of HE. The study therefore aimed to investigate the potential influences of sorafenib on HE and the relevant risk factors in cirrhotic rats.

METHODS

Liver cirrhosis was induced in Spraque-Dawley rats with common bile duct ligation (CBDL). CBDL rats received sorafenib 1 mg/kg/day or distilled water (DW) via oral gavage since the 15th day post surgery for 2 weeks. On the 28th day, after motor activities measurements, mean arterial pressure, portal pressure and heart rate were checked. Thereafter, cerebral cortex and cerebellum were dissected for oxidative stress study and blood was collected for liver biochemistry survey.

RESULTS

Sorafenib significantly reduced portal pressure (22%) and collateral shunting degree (15%) in cirrhotic rats. Alanine transaminase, aspartate transaminase, total bilirubin and ammonia were similar in sorafenib- and DW-treated groups. Motor activities were not significantly altered by sorafenib. In cerebrum, the oxidant and antioxidant substances activities were not significantly different between the two groups, whereas they were divergent in cerebellum and hippocampus.

CONCLUSION

By surveying three main aspects involved in the pathogenesis of HE, this study demonstrates that sorafenib does not increase the risk of HE in cirrhotic rats.

The structure of acyl coenzyme A-cholesterol acyltransferase and its potential relevance to atherosclerosis

Acyl coenzyme A-cholesterol acyltransferase (ACAT) catalyzes the formation of intracellular cholesterol esters. It is present in a variety of tissues and is believed to play significant roles in cholesterol homeostasis. Under pathologic conditions, accumulation of the ACAT reaction product as cytoplasmic cholesterol ester lipid droplets within macrophages and smooth muscle cells is a characteristic feature of early lesions of human atherosclerotic plaques. ACAT is a membrane protein located in the endoplasmic reticulum. Its activity is susceptible to inactivation by detergents, and it has never been purified to homogeneity; no antibodies directed against it have been reported. Through a somatic cell and molecular genetic approach, we have recently succeeded in molecular cloning and functional expression of a human macrophage ACAT cDNA. This cDNA contains an open reading frame of 1650 base pairs encoding an integral membrane protein of 550 amino acids. Protein homology analysis shows that the predicted protein sequence shares short regions of homology with other enzymes involved in the catalysis of acyl adenylate formation with subsequent acyl thioester formation and acyl transfer. The ACAT cDNA will enable the investigation of ACAT biochemistry and molecular biology. It will speed up the design of specific ACAT inhibitors as drugs that may provide more effective therapeutic treatment or prevention of atherosclerosis. In addition, studies on the physiologic roles of ACAT in various tissues can now be undertaken through transgenic animal research.

A novel approach for normalizing the photoreflectance spectrum by using polymer-dispersed liquid crystal

This study developed a novel type of normalization procedure for modulation reflectance spectroscopy experiments to obtain the relative change in the reflectance spectrum, ΔR/R. This technique uses a polymer-dispersed liquid crystal to ensure that the dc component of the signal from the detector remained constant by varying the intensity of the light striking the sample. This method is particularly useful for photoreflectance measurement, which may encounter background problems because of scattered pump light and/or photoluminescence. It does not require a change in the gain of the detector or the use of a variable neutral density filter mounted on a servo-motor.

Comorbidities associated with psoriasis - data from the malaysian psoriasis registry

All around the world, there is growing evidence of the association between psoriasis and comorbidities which increase the risk of cardiovascular disease. This study aims to determine the prevalence of various comorbidities among adult psoriasis patients in Malaysia. A cross-sectional study was conducted among patients in the Malaysian Psoriasis Registry from January 2007 to December 2008. A total of 2,267 adult patients with psoriasis from 13 dermatology centers were included. Prevalence of various comorbidities were: hypertension 25.9%, diabetes mellitus 17.7 %, dyslipidaemia 17.8%, overweight 33.2%, obesity 20.7%, ischaemic heart disease 5.8% and cerebrovascular disease 1.4%. These comorbidities were more prevalent in patients with psoriasis of late-onset and longer duration. Active screening of these comorbidities in all adult psoriasis patients is recommended.

Cannabinoid receptor 2 agonist ameliorates mesenteric angiogenesis and portosystemic collaterals in cirrhotic rats

Angiogenesis in liver cirrhosis leads to splanchnic hyperemia, increased portal inflow, and portosystemic collaterals formation, which may induce lethal complications, such as gastroesophageal variceal hemorrhage and hepatic encephalopathy. Cannabinoids (CBs) inhibit angiogenesis, but the relevant influences in cirrhosis are unknown. In this study, Spraque-Dawley rats received common bile duct ligation (BDL) to induce cirrhosis. BDL rats received vehicle, arachidonyl-2-chloroethylamide (cannabinoid receptor type 1 [CB(1) ] agonist), JWH-015 (cannabinoid receptor type 2 [CB(2) ] agonist), and AM630 (CB(2) antagonist) from days 35 to 42 days after BDL. On the 43rd day, hemodynamics, presence of CB receptors, severity of portosystemic shunting, mesenteric vascular density, vascular endothelial growth factor (VEGF), VEGFR-1, VEGFR-2, phospho-VEGFR-2, cyclooxygenase (COX)-1, COX-2, and endothelial nitric oxide synthase (eNOS) expressions as well as plasma VEGF levels were evaluated. Results showed that CB(1) and CB(2) receptors were present in left adrenal veins of sham rats, splenorenal shunts (the most prominent intra-abdominal shunts) of BDL rats, and mesentery of sham and BDL rats. CB(2) receptor was up-regulated in splenorenal shunts of BDL rats. Both acute and chronic JWH-015 treatment reduced portal pressure and superior mesenteric arterial blood flow. Compared with vehicle, JWH-015 significantly alleviated portosystemic shunting and mesenteric vascular density in BDL rats, but not in sham rats. The concomitant use of JWH-015 and AM630 abolished JWH-015 effects. JWH-133, another CB(2) agonist, mimicked the JWH-015 effects. JWH-015 decreased mesenteric COX-1, COX-2 messenger RNA expressions, and COX-1, COX-2, eNOS protein expressions. Furthermore, JWH-015 decreased intrahepatic angiogenesis and fibrosis.

CONCLUSIONS

CB(2) agonist alleviates portal hypertension (PH), severity of portosystemic collaterals and mesenteric angiogenesis, intrahepatic angiogenesis, and fibrosis in cirrhotic rats. The mechanism is, at least partly, through COX and NOS down-regulation. CBs may be targeted in the control of PH and portosystemic collaterals.

Aliskiren reduces portal pressure in portal hypertensive rats

BACKGROUND

Aliskiren is a direct renin inhibitor used in the treatment for arterial hypertension. It can also augment nitric oxide (NO) production, which plays a crucial role in the pathogenesis of portal hypertension and modulation of porto-systemic collaterals. This study investigated the effects of aliskiren on portal pressure and porto-systemic collaterals of portal vein-ligated (PVL) rats.

MATERIALS AND METHODS

Sham-operated and PVL rats received aliskiren (50 mg/kg per day) or distilled water (control) treatment for 10 days. The mean arterial pressure and portal pressure were measured by catheterization of the right femoral artery and mesenteric vein, while the superior mesenteric arterial blood flow was measured by Doppler technique. The left adrenal vein and superior mesentery artery were dissected for mRNA study. The PVL rats also underwent preincubation with (i) Krebs solution (control); (ii) 10(-4) M aliskiren; or (iii) 10(-4) M aliskiren plus nonselective NO inhibitor N(ω)-nitro-L-arginine (10(-4) M), followed by the addition of arginine vasopressin (AVP) to evaluate the collateral vascular responsiveness.

RESULTS

Aliskiren had systemic arterial pressure- and portal pressure-lowering effects in PVL rats. Superior mesentery arterial resistance also decreased. The constitutive NO synthase was enhanced in the left adrenal vein and superior mesentery artery after aliskiren treatment. Aliskiren attenuated the collateral vasoconstrictive effects of AVP, but the vasodilatory effects were abolished after nonselective NO synthase inhibition.

CONCLUSIONS

Chronic aliskiren use reduces portal pressure in portal hypertensive rats partly due to the modulation of splanchnic and collateral NO synthase.

Pravastatin for thioacetamide-induced hepatic failure and encephalopathy

BACKGROUND

Nitric oxide (NO) inhibition aggravates hepatic damage and encephalopathy and increases mortality in rats with thioacetamide (TAA)-induced acute liver failure. Statins enhance NO production but whether they influence the above parameters are unknown.

MATERIAL AND METHODS

Male Sprague-Dawley rats were used. In the first series, TAA (350 mg/kg per day, i.p. for 3 days) was administered to induce acute liver failure. Control rats received saline. Rats received distilled water or pravastatin (20 mg/kg per day, p.o.) from 2 days before to 3 days after TAA or saline injection. In the second series, liver cirrhosis was induced by common bile duct ligation (BDL). Sham-operated rats served as controls. Rats received distilled water or pravastatin for 5 or 14 days until the 42nd day after operation. On the last day of treatment, survival, motor activities, serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), bilirubin, ammonia and brain histology were evaluated.

RESULTS

Thioacetamide and BDL rats showed higher ALT, AST, bilirubin and ammonia levels and lower motor activity counts compared with their corresponding control groups. In TAA rats, pravastatin elicited higher total and ambulatory motor activity counts and lower AST and total bilirubin levels. Survival was improved, whereas brain H&E staining was not significantly different in TAA rats with or without pravastatin treatment. In BDL groups, rats with or without pravastatin treatment were not different in motor activity counts and liver biochemistry.

CONCLUSIONS

Pravastatin ameliorates hepatic encephalopathy and liver biochemistry and improves survival in rats with acute liver failure, but not in those with cirrhosis.

The roles of angiotensin II receptors in the portosystemic collaterals of portal hypertensive and cirrhotic rats

BACKGROUND/AIMS

In liver cirrhosis/portal hypertension, collaterals as varices may bleed and are influenced by vasoresponsiveness. An angiotensin blockade ameliorates portal hypertension but the influence on collaterals is unknown.

METHODS

Portal hypertension and cirrhosis were induced by portal vein (PVL) and common bile duct ligation (BDL). Hemodynamics, real-time PCR of angiotensin II receptors (AT(1)R, AT(2)R) in the left adrenal vein (LAV, sham) and splenorenal shunt derived from LAV (PVL, BDL) were performed. With an in situcollateral perfusion model, angiotensin II vasoresponsiveness with different preincubations was evaluated: (1) vehicle; (2) AT(1)R blocker losartan; (3) losartan plus nonselective nitric oxide synthase (NOS) inhibitor (N(ω)-nitro-L-arginine); (4) AT(2)R blocker PD123319; (5) PD123319 plus N(ω)-nitro-L-arginine; (6) N(ω)-nitro-L-arginine, and (7) losartan plus inducible NOS inhibitor aminoguanidine.

RESULTS

LAV AT(1)R and AT(2)R expression decreased in PVL and BDL rats. Losartan attenuated angiotensin II-elicited vasoconstriction but PD123319 had no effect. N(ω)-nitro-L-arginine but not aminoguanidine reversed the losartan effect.

CONCLUSIONS

Angiotensin receptors are downregulated in the collateral vessel of portal hypertensive and cirrhotic rats. The AT(1)R blockade attenuates the angiotensin II vasoconstrictive effect, suggesting AT(1)R mediates collateral vasoconstriction and the influence of AT(2)R is negligible. The lack of aminoguanidine influence indicates that endothelial NOS participates in the losartan effect.

Portosystemic collaterals are not prerequisites for the development of hepatic encephalopathy in cirrhotic rats

BACKGROUND

Liver functions and portosystemic collaterals influence the development and severity of hepatic encephalopathy (HE) in cirrhosis. However, it has not been examined which factor has a greater influence or if shunts can be used to determine the presence and severity of HE. The expression of tumor necrosis factor-α (TNF-α) is increased in cirrhosis, and its role in HE deserves further evaluation.

METHODS

Portal hypertension was induced by portal vein ligation (PVL; a model of high-degree portosystemic shunting without significant liver damage) and liver cirrhosis was induced by bile duct ligation (BDL; a model of low-degree shunting with liver cirrhosis) in male Spraque-Dawley rats. Sham-operated rats were used as controls. Motor activity counts, hemodynamic parameters, plasma levels, liver biochemistry parameters, TNF-α, and a flow-pressure curve study of portosystemic collaterals (where a higher slope indicates fewer portosystemic collaterals) were performed on Day 7 after PVL and Week 5 after BDL.

RESULTS

Portal pressure was significantly higher in the PVL and BDL groups than in controls. The liver biochemistry parameters, TNF-α, and motor activities were not significantly different between the PVL and PVL-control groups. In the BDL group, TNF-α, AST, and total bilirubin levels were significantly higher and the motor activity counts were lower than in the BDL-control group. Moreover, in the BDL rats, TNF-α (p=0.037, R=-0.490), AST (p=0.007, R=-0.595) and total bilirubin (P=0.001, R=-0.692) levels, but not the slopes of the flow-pressure curves, were significantly and negatively correlated with the motor activity counts.

CONCLUSION

The presence of a high degree of portosystemic shunting without significant liver damage may not be adequate for the development of HE.

Assessment of first-year post-graduate residents: usefulness of multiple tools

BACKGROUND

Objective Structural Clinical Examination (OSCE) usually needs a large number of stations with long test time, which usually exceeds the resources available in a medical center. We aimed to determine the reliability of a combination of Direct Observation of Procedural Skills (DOPS), Internal Medicine in-Training Examination (IM-ITE(®)) and OSCE, and to verify the correlation between the small-scale OSCE+DOPS+IM-ITE(®)-composited scores and 360-degree evaluation scores of first year post-graduate (PGY(1)) residents.

METHODS

Between 2007 January to 2010 January, two hundred and nine internal medicine PGY1 residents completed DOPS, IM-ITE(®) and small-scale OSCE at our hospital. Faculty members completed 12-item 360-degree evaluation for each of the PGY(1) residents regularly.

RESULTS

The small-scale OSCE scores correlated well with the 360-degree evaluation scores (r = 0.37, p < 0.021). Interestingly, the addition of DOPS scores to small-scale OSCE scores [small-scale OSCE+DOPS-composited scores] increased it's correlation with 360-degree evaluation scores of PGY(1) residents (r = 0.72, p < 0.036). Further, combination of IM-ITE(®) score with small-scale OSCE+DOPS scores [small-scale OSCE+DOPS+IM-ITE(®)-composited scores] markedly enhanced their correlation with 360-degree evaluation scores (r = 0.85, p < 0.016).

CONCLUSION

The strong correlations between 360-degree evaluation and small-scale OSCE+DOPS+IM-ITE(®)-composited scores suggested that both methods were measuring the same quality. Our results showed that the small-scale OSCE, when associated with both the DOPS and IM-ITE(®), could be an important assessment method for PGY(1) residents.

Measurements of natural carbonate rare earth elements in femtogram quantities by inductive coupled plasma sector field mass spectrometry

A rapid and precise standard-bracketing method has been developed for measuring femtogram quantity rare earth element (REE) levels in natural carbonate samples by inductively coupled plasma sector field mass spectrometry that does not require chemical separation steps. A desolvation nebulization system was used to effectively reduce polyatomic interference and enhance sensitivity. REE/Ca ratios are calculated directly from the intensities of the ion beams of (46)Ca, (139)La, (140)Ce, (141)Pr, (146)Nd, (147)Sm, (153)Eu, (160)Gd, (159)Tb, (163)Dy, (165)Ho, (166)Er, (169)Tm, (172)Yb, and (175)Lu using external matrix-matched synthetic standards to correct for instrumental ratio drifting and mass discrimination. A routine measurement time of 3 min is typical for one sample containing 20-40 ppm Ca. Replicate measurements made on natural coral and foraminiferal samples with REE/Ca ratios of 2-242 nmol/mol show that external precisions of 1.9-6.5% (2 RSD) can be achieved with only 10-1000 fg of REEs in 10-20 μg of carbonate. We show that different sources for monthly resolved coral ultratrace REE variability can be distinguished using this method. For natural slow growth-rate carbonate materials, such as sclerosponges, tufa, and speleothems, the high sample throughput, high precision, and high temporal resolution REE records that can be produced with this procedure have the potential to provide valuable time-series records to advance our understanding of paleoclimatic and paleoenvironmental dynamics on different time scales.

Routine drainage is not necessary after laparoscopic gastric bypass

INTRODUCTION

Routine intra-abdominal drainage has been recommended for detecting surgical complications, such as anastomotic leaks or intra-abdominal hemorrhage, after laparoscopic gastric bypass for morbid obesity. The aim of this study was to determine whether routine drainage after laparoscopic gastric bypass is indeed necessary.

METHODS

Patients undergoing laparoscopic gastric bypass with intra-abdominal drainage (D-group) were compared with those without drainage (N-group) in a retrospective study. The main outcome measures were postoperative course and complications.

RESULTS

No differences were observed in the postoperative complications. Both groups had one major complication of leakage (1/90, 1.1%). Minor complications occurred in six D-group patients (6/90, 6.7%) and eight N-group patients (8/90, 8.9%) (P=0.578). No difference was observed in postoperative analgesic dose usage (mean ± SD: 63 ± 37 mg vs 60 ± 31 mg; P=0.963) or length of stay hospital (5.2 ± 2.6 d vs 4.7 ± 1.8 d; P=0.135). However, the N-group had a shorter time to flatus passage compared to the D-group (1.6 ± 0.7 d vs 1.2 ± 0.5 d; P=0.006).

CONCLUSION

Routine abdominal drainage is not necessary after a successful laparoscopic gastric bypass for morbidly obese patients. Drainage omission may contribute to a quicker recovery without additional surgical complications.

A core competence-based objective structured clinical examination (OSCE) in evaluation of clinical performance of postgraduate year-1 (PGY₁) residents

BACKGROUND

Clinical competency certifications are important parts of internal medicine residency training. This study aims to evaluate a composite objective structured clinical examination (OSCE) that assesses postgraduate year-1 (PGY(1)) residents' acquisition of the six core competencies defined by the Accreditation council for Graduate Medical Education (ACGME).

METHODS

Six-core-competency-based OSCE was used as examination of the clinical performance of 192 PGY(1) residents during their 3-month internal medicine training between 2007 January and 2009 December. For each year, the reliability of the entire examination was calculated with Cronbach's alpha.

RESULTS

The reliability of six-core-competency-based OSCE was acceptable, ranging from 0.69 to 0.87 between 2007 and 2009. In comparison with baseline scores, the summary scores and core-competency subscores all showed significant increase after PGY(1) residents finished their 3-month internal medicine training program.

CONCLUSION

By using a structured development process, the authors were able to create reliable evaluation items for determining PGY(1) residents' acquisition of the ACGME core competencies.

Clinical instructors' perception of a faculty development programme promoting postgraduate year-1 (PGY1) residents' ACGME six core competencies: a 2-year study

Objective The six core competencies designated by Accreditation Council for Graduate Medical Education (ACGME) are essential for establishing a patient centre holistic medical system. The authors developed a faculty programme to promote the postgraduate year 1 (PGY(1)) resident, ACGME six core competencies. The study aims to assess the clinical instructors' perception, attitudes and subjective impression towards the various sessions of the 'faculty development programme for teaching ACGME competencies.' Methods During 2009 and 2010, 134 clinical instructors participated in the programme to establish their ability to teach and assess PGY(1) residents about ACGME competencies. Results The participants in the faculty development programme reported that the skills most often used while teaching were learnt during circuit and itinerant bedside, physical examination teaching, mini-clinical evaluation exercise (mini-CEX) evaluation demonstration, training workshop and videotapes of 'how to teach ACGME competencies.' Participants reported that circuit bedside teaching and mini-CEX evaluation demonstrations helped them in the interpersonal and communication skills domain, and that the itinerant teaching demonstrations helped them in the professionalism domain, while physical examination teaching and mini-CEX evaluation demonstrations helped them in the patients' care domain. Both the training workshop and videotape session increase familiarity with teaching and assessing skills. Participants who applied the skills learnt from the faculty development programme the most in their teaching and assessment came from internal medicine departments, were young attending physician and had experience as PGY(1) clinical instructors. Conclusions According to the clinical instructors' response, our faculty development programme effectively increased their familiarity with various teaching and assessment skills needed to teach PGY(1) residents and ACGME competencies, and these clinical instructors also then subsequently apply these skills.

Simvastatin effects on portal-systemic collaterals of portal hypertensive rats

BACKGROUND AND AIM

Portal-systemic collateral vascular resistance and vasoconstrictor responsiveness are crucial in portal hypertension and variceal bleeding control. Statins enhance vasodilators production, but their influence on collaterals is unknown. This study aimed to survey the effect of simvastatin on collaterals.

METHODS

Partially portal vein-ligated rats received oral simvastatin (20 mg/kg/day) or distilled water from -2 to +7 day of ligation. After hemodynamic measurements on the eighth postoperative day, baseline perfusion pressure (i.e. an index of collateral vascular resistance) and arginine vasopressin (AVP, 0.1 nM-0.1 microM) responsiveness were evaluated with an in situ perfusion model for collateral vascular beds. RT-PCR of endothelial NO synthase (eNOS), inducible NOS (iNOS), cyclooxygenase-1 (COX-1), COX-2, thromboxane A(2) synthase (TXA(2)-S) and prostacyclin synthase genes was performed in parallel groups for splenorenal shunt (SRS), the most prominent intra-abdominal collateral vessel. To determine the acute effects of simvastatin, collateral AVP response was assessed with vehicle or simvastatin. SRS RT-PCR of eNOS, iNOS, COX-1, COX-2 and TXA(2)-S, and measurements of perfusate nitrite/nitrate, 6-keto-PGF1(alpha) and TXB(2) levels were performed in parallel groups without AVP.

RESULTS

Acute simvastatin administration enhanced SRS eNOS expression and elevated perfusate nitrite/nitrate and 6-keto-PGF1(alpha) concentrations. Chronic simvastatin treatment reduced baseline collateral vascular resistance and portal pressure and enhanced SRS eNOS, COX-2 and TXA(2)-S mRNA expression. Neither acute nor chronic simvastatin administration influenced collateral AVP responsiveness.

CONCLUSION

Simvastatin reduces portal-systemic collateral vascular resistance and portal pressure in portal hypertensive rats. This may be related to the enhanced portal-systemic collateral vascular NO and prostacyclin activities.

Pravastatin administration does not induce detrimental effects on hemodynamics and collaterals of portal hypertensive rats

BACKGROUND AND AIMS

The 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor can enhance endothelial nitric oxide synthase expression and induce vasodilatation. The vasodilatory effect may be detrimental to portal-systemic collaterals due to aggravating the shunting degrees. The present study investigated the effects of pravastatin, a HMG-CoA reductase inhibitor, on the collateral vascular responsiveness to endothelin-1 (ET-1) and portal-systemic shunting in portal hypertensive rats.

METHODS

The partial portal vein-ligated (PVL) rats received either pravastatin (25 mg/kg per day) or distilled water since 2 days prior to until 7 days after ligation. On the 8(th) day following hemodynamic measurements, the collateral vascular responsiveness to ET-1 was evaluated by an in situ collateral perfusion model. The shunting degrees of collaterals were evaluated by constructing vascular flow-pressure curves and color microsphere study, respectively. PVL rats underwent pre-incubation with: (i) Krebs solution (control); or Krebs solution plus (ii) 2 x 10(-5) M pravastatin; (iii) pravastatin + N(omega)-nitro-L-arginine (10(-4) M); and (iv) pravastatin + indomethacin (10(-5) M), followed by ET-1 (10(-10)-10(-7) M) administration to evaluate the collateral vascular responsiveness.

RESULTS

In chronic study, pravastatin did not modify systemic and portal hemodynamics and collateral vascular responsiveness to ET-1. The resistances of flow-pressure curves and the microsphere study demonstrated similar shunting degrees between both groups. Furthermore, pravastatin pre-incubation didn't reduce collateral perfusion pressure to ET-1.

CONCLUSION

Chronic pravastatin administration does not induce detrimental effects on hemodynamics and collaterals in PVL rats, nor does it influence the shunting degree. In addition, it does not modify the vasoconstrictive effect of ET-1 on the collaterals of PVL rats.

Lack of therapeutic effects of gabexate mesilate on the hepatic encephalopathy in rats with acute and chronic hepatic failure

BACKGROUND AND AIM

Inflammation plays a pivotal role in liver injury. Gabexate mesilate (GM, a protease inhibitor) inhibits inflammation by blocking various serine proteases. This study examined the effects of GM on hepatic encephalopathy in rats with acute and chronic liver failure.

METHODS

Acute and chronic liver failure (cirrhosis) were induced by intraperitoneal TAA administration (350 mg/kg/day for 3 days) and common bile duct ligation, respectively, in male Sprague-Dawley rats. Rats were randomized to receive either GM (50 mg/10 mL/kg) or saline intraperitoneally for 5 days. Severity of encephalopathy was assessed by the Opto-Varimex animal activity meter and hemodynamic parameters, mean arterial pressure and portal pressure, were measured (only in chronic liver failure rats). Plasma levels of liver biochemistry, ammonia, nitrate/nitrite, interleukins (IL) and tumor necrosis factor (TNF)-alpha were determined.

RESULTS

In rats with acute liver failure, GM treatment significantly decreased the plasma levels of alanine aminotransferase (P = 0.02), but no significant difference of motor activity, plasma levels of ammonia, IL-1beta, IL-6, IL-10 and TNF-alpha or survival was found. In chronic liver failure rats, GM significantly lowered the plasma TNF-alpha levels (P = 0.04). However, there was no significant difference of motor activity, other biochemical tests or survival found. GM-treated chronic liver failure rats had higher portal pressure (P = 0.04) but similar mean arterial pressure in comparison with saline-treated rats.

CONCLUSIONS

Chronic GM treatment does not have a major effect on hepatic encephalopathy in rats with TAA-induced acute liver failure and rats with chronic liver failure induced by common bile duct ligation.

Leucinopine, a characteristic compound of some crown-gall tumors

An unusual compound has been found in crowngall tumors induced by those Agrobacterium tumefaciens strains that utilize neither octopine nor nopaline. The compound has been isolated and shown by proton and carbon-13 NMR spectroscopy and by synthesis to be N(2)-(1,3-dicarboxypropyl)-L-leucine, which also exists in a cyclized (i.e., lactam) form. This compound, which we name "leucinopine," was not detected in octopine tumors, nopaline tumors, or the tumors induced by A. tumefaciens strains 181 and EU6.