Ezetimibe treatment reduces oxidized low-density lipoprotein in biliary cirrhotic rats

BACKGROUND

In liver cirrhosis, chronic inflammation is associated with an increase in oxidative stress, and subsequently an increase in the concentration of oxidized low-density lipoprotein (ox-LDL). Ezetimibe is a lipid-lowering agent with anti-inflammation and anti-oxidative stress activities. This study aimed to investigate the effect of ezetimibe treatment on ox-LDL in cirrhotic rats.

METHODS

Biliary cirrhosis was induced in Sprague-Dawley rats with common bile duct ligation (BDL). Sham-operated rats served as surgical controls. Ezetimibe (10 mg/kg/d) or vehicle was administered in the sham-operated or BDL rats for 4 weeks, after which hemodynamic parameters, biochemistry data, and oxidative stress were evaluated. Plasma and intrahepatic ox-LDL levels were also examined, and hepatic proteins were analyzed to explore the mechanism of ezetimibe treatment.

RESULTS

The BDL rats had typical features of cirrhosis including jaundice, impaired liver function, hyperlipidemia, and elevated ox-LDL levels compared to the sham-operated rats. Ezetimibe treatment did not affect hemodynamics, liver biochemistry, or plasma lipid levels. However, it significantly reduced oxidative stress, plasma levels of ox-LDL, and tumor necrosis factor α. In addition, ezetimibe upregulated the hepatic protein expression of an ox-LDL scavenger (lectin-like ox-LDL rececptor-1), which resulted in reductions in intrahepatic ox-LDL and fat accumulation in the BDL rats. Nevertheless, ezetimibe treatment did not ameliorate hepatic inflammation or liver fibrosis.

CONCLUSION

Ezetimibe reduced plasma and intrahepatic ox-LDL levels in the cirrhotic rats. Furthermore, it ameliorated intrahepatic fat accumulation and oxidative stress. However, ezetimibe did not alleviate hepatic fibrosis or inflammation in the biliary cirrhotic rats.

Dual angiotensin receptor and neprilysin inhibitor reduced portal pressure through peripheral vasodilatation and decreasing systemic arterial pressure in cirrhotic rats

BACKGROUND

Portal hypertension develops along with the progression of liver cirrhosis. Natriuretic peptides have been shown to reduce portal pressure but concomitantly activate the renin-angiotensin-aldosterone system (RAAS). Angiotensin receptor-neprilysin inhibitors (ARNIs) upregulate natriuretic peptides and avoid the adverse effects of RAAS activation. ARNIs have been shown to reduce portal pressure in rats with pre-hepatic portal hypertension, which involves relatively little liver injury. This study aimed to evaluate the relevant effects of an ARNI in rats with both liver cirrhosis and portal hypertension.

METHODS

Male Sprague-Dawley rats received common bile duct ligation to induce liver cirrhosis and portal hypertension. Sham-operated rats served as surgical controls. All rats were randomly allocated into three groups to receive distilled water (vehicle), LCZ696 (an ARNI), or valsartan for 4 weeks. Portal hypertension and relevant derangements were assessed after treatment.

RESULTS

Portal hypertension and hyperdynamic circulation developed in the cirrhotic rats. In the rats with cirrhosis and portal hypertension, both LCZ696 and valsartan reduced portal hypertension, mean arterial pressure, and systemic vascular resistance. The decrease in portal pressure was highly associated with the reduction in arterial pressure and systemic vascular resistance. Blood flow in hepatic, splanchnic, and portosystemic collateral systems was not altered. LCZ696 did not significantly influence liver injury or plasma cytokine levels. Liver fibrosis and splanchnic angiogenesis were not affected.

CONCLUSION

ARNI treatment exerted portal pressure lowering effects via peripheral vasodilatation and decreasing systemic arterial pressure in the rats with liver cirrhosis and portal hypertension. Caution should be taken when using ARNIs in liver cirrhosis.

Sodium-Glucose Cotransporter-2 Inhibition Exacerbates Hepatic Encephalopathy in Biliary Cirrhotic Rats

In liver cirrhosis, hepatic inflammation and abundant portal-systemic collaterals are indicated for the development of hepatic encephalopathy. Sodium-glucose cotransporter-2 (SGLT-2) inhibitors are a type of anti-diabetic agent which exert pleiotropic and anti-inflammatory effects. Diabetes and chronic liver disease often coexist, but the influence of SGLT-2 inhibition on liver cirrhosis and hepatic encephalopathy remains unknown. This study investigated the effect of SGLT-2 inhibition on cirrhotic rats. Biliary cirrhosis was induced in Sprague-Dawley rats via common bile duct ligation. A total of two weeks of treatment with the SGLT-2 inhibitor, empagliflozin 30 mg/kg/d, was applied. The motor activities, hemodynamics, biochemistry parameters, plasma levels of vascular endothelial growth factor (VEGF), and the severity of portal-systemic collateral shunts were measured. The hepatic histopathology and protein expressions were examined. We found that empagliflozin treatment did not affect hemodynamics, liver biochemistry, or blood glucose levels in cirrhotic rats. Empagliflozin did not affect hepatic inflammation and fibrosis. The protein expression of factors related to liver injury were not influenced by empagliflozin. However, empagliflozin decreased motor activities in cirrhotic rats and increased portal-systemic collateral shunts and VEGF plasma levels. In summary, SGLT-2 inhibition by empagliflozin did not ameliorate portal hypertension and hepatic inflammation in cirrhotic rats. In contrast, it exacerbated hepatic encephalopathy, which was evidenced by a decrease in motor activity. A possible mechanism could be an increase of portal-systemic shunts related to VEGF upregulation. Therefore, empagliflozin use should be cautious in cirrhotic patients regarding the development of hepatic encephalopathy. SIGNIFICANCE STATEMENT: Sodium-glucose cotransporter-2 inhibition by empagliflozin did not ameliorate portal hypertension and hepatic inflammation in cirrhotic rats. In contrast, it exacerbated hepatic encephalopathy through increased portal-systemic shunts related to VEGF up-regulation.

Effects of PCSK-9 Inhibition by Alirocumab Treatments on Biliary Cirrhotic Rats

Hyperlipidemia and oxidative stress with elevated oxidized low-density lipoprotein (ox-LDL) exacerbate hepatic inflammation and fibrosis. The plasma level of low-density lipoprotein (LDL) is controlled by proprotein convertase subtilisin/kexin 9 (PCSK9). Alirocumab is a monoclonal antibody that decreases LDL via inhibiting PCSK9 function. Apart from lipid-lowering effects, alirocumab exerts anti-inflammation, anti-angiogenesis and anti-oxidant effects. This study aims to investigate the impact of alirocumab treatment on common bile duct ligation (BDL)-induced biliary cirrhotic rats. After a 4-week treatment of alirocumab, the hemodynamic data, blood biochemistry, ox-LDL level, oxidative stress markers, severity of hepatic encephalopathy and abnormal angiogenesis of BDL rats were measured and compared to the control group. BDL rats presented cirrhotic pictures and elevated ammonia, total cholesterol, LDL and ox-LDL levels compared to the control group. Alirocumab decreased plasma levels of total cholesterol, LDL, and oxidative stress markers; however, it did not affect the hemodynamics, liver and renal biochemistry, and the plasma levels of ammonia and ox-LDL. The motor activities, portal-systemic collaterals and mesenteric vascular density were not significantly different between alirocumab-treated and control groups. In addition, it did not affect hepatic inflammation, intrahepatic angiogenesis, liver fibrosis and free cholesterol accumulation in the liver of BDL rats. In conclusion, PCSK9 inhibition by alirocumab treatment ameliorates hyperlipidemia and systemic oxidative stress in biliary cirrhotic rats. However, it does not affect the plasma level of ox-LDL, intrahepatic inflammation and fibrosis. In addition, PCSK9 inhibition has a neutral effect on abnormal angiogenesis and hepatic encephalopathy in biliary cirrhotic rats.

Longitudinal assessment of milestone development among internal medicine residents in Taiwan

BACKGROUND/PURPOSE

The Accreditation Council for Graduate Medical Education (ACGME) milestones have been implemented in residency training worldwide. We investigated the development of individual competency in first-year residents (R1) and second-year postgraduate students (PGY2) who received internal medicine training in Taiwan.

METHODS

A multicenter observational cohort study was conducted to evaluate the competency-based milestone evaluation designed by the Taiwan Society of Internal Medicine in 2019. The evaluation was based on the ACGME-accredited milestone ratings. Periodic evaluation of milestone achievements of R1 and PGY2, who entered the internal medicine residency training at six medical centers, was performed. Each resident was evaluated every 3 months.

RESULTS

Among the 98 R1 enrolled in 2019, substantial improvement in sub-competencies, including skill in performing procedures (Patient Care 4), clinical knowledge (Medical Knowledge 1), knowledge of diagnostic testing and procedures (Medical Knowledge 2), and identify impact the cost of health care and practices cost-effective care (Systems Based Practice 3) during the two years of training. Among the 107 R1 and 46 PGY2 enrolled in 2020, no significant difference in baseline milestone ratings was observed. However, the milestone assessments of R1 in 2020 showed improvement in nearly all sub-competencies compared with the stationary status of PGY2 in 2020.

CONCLUSION

We demonstrate the application of ACGME-based accredited milestone ratings to target the educational goals of internal medicine residency training in Taiwan. Differences in milestone ratings between different PGY training systems exist. The long-term impact of performance among different PGY training systems requires further investigation.

Lycopene treatment improves intrahepatic fibrosis and attenuates pathological angiogenesis in biliary cirrhotic rats

BACKGROUND

Liver cirrhosis is characterized by liver fibrosis and pathological angiogenesis, which results in hyperdynamic circulation, portal-systemic collateral vascular formation, and abnormal angiogenesis. Lycopene is a nutrient mostly found in tomatoes. The beneficial effects of lycopene include anti-inflammation, anti-oxidation, anti-fibrosis, and anti-angiogenesis; however, the association between liver cirrhosis and pathological angiogenesis has yet to be studied. This study aimed to investigate the effects of lycopene on biliary cirrhotic rats.

METHODS

The efficacy of lycopene treatment in common bile duct ligation (BDL)-induced biliary cirrhotic rats was evaluated. Sham-operated rats served as surgical controls. Lycopene (20 mg/kg/day, oral gavage) or vehicle was administered to BDL or sham-operated rats for 4 weeks, after which the hemodynamics, liver biochemistry, portal-systemic shunting, liver and mesenteric angiogenesis, and hepatic angiogenesis-related protein expressions were examined.

RESULTS

Lycopene alleviated hyperdynamic circulation as evidenced by decreased cardiac index and increased peripheral vascular resistance (p < 0.05), but it did not affect portal pressure or liver biochemistry in the BDL rats (p > 0.05). Lycopene significantly diminished the shunting degree of portal-systemic collaterals (p = 0.04) and mesenteric vascular density (p = 0.01), and also ameliorated intrahepatic angiogenesis and liver fibrosis. In addition, lycopene upregulated endothelial nitric oxide synthase, protein kinase B (Akt) and phosphatidylinositol 3-kinases (PI3K), and downregulated vascular endothelial growth factor receptor 2 (VEGFR-2) protein expressions (p < 0.05) in the livers of the BDL rats.

CONCLUSION

Lycopene ameliorated liver fibrosis, hyperdynamic circulation, and pathological angiogenesis in biliary cirrhotic rats, possibly through the modulation of intrahepatic Akt/PI3K/eNOS and VEGFR-2 pathways.

Effects of dipeptidyl peptidase-4 inhibition on portal hypertensive and cirrhotic rats

BACKGROUND

Portal hypertension is a pathophysiological abnormality with distinct vascular derangements associated with liver cirrhosis. Dipeptidyl peptidase-4 (DPP-4) inhibitors are antidiabetic agents which exert pleiotropic vascular effects, but their relevant impact on portal hypertension and liver cirrhosis remains unclear. This study aims to clarify this issue.

METHODS

Rats receiving partial portal vein ligation (PVL) and common bile duct ligation (BDL) served as experimental models for portal hypertension and cirrhosis, respectively. After linagliptin (a DPP-4 inhibitor) treatment, the survival rate, hemodynamics, biochemistry parameters and liver histopathology were evaluated. In addition, the collateral vascular responsiveness and severity of portal-systemic shunting were examined. mRNA and protein expression in the vasculature and liver were also examined.

RESULTS

Linagliptin significantly reduced portal pressure (control vs linagliptin: 12.9 ± 1.2 vs 9.1 ± 2.0 mmHg, p = 0.001) and upregulated nitric oxide synthase expression in the collateral vessel, superior mesentery artery, and liver of PVL rats. However, the portal hypotensive effect was insignificant in BDL rats. Glucose plasma levels, liver and renal biochemistry parameters were not significantly altered by linagliptin. The degree of portal-systemic shunting and collateral vascular responsiveness were also not significantly altered by linagliptin treatment. Linagliptin did not improve liver fibrosis and hepatic inflammation in BDL rats.

CONCLUSION

DPP-4 inhibition by linagliptin reduced portal pressure in portal hypertensive rats but not in cirrhotic rats. It may act by decreasing intrahepatic resistance via upregulation of hepatic nitric oxide synthase in portal hypertensive rats.

Matrix metalloproteinase-9 inhibition or deletion attenuates portal hypertension in rodents

Liver cirrhosis and portal hypertension are accompanied by hyperdynamic circulation, angiogenesis and portosystemic collaterals. Matrix metalloproteinases (MMPs) participate in fibrogenesis and angiogenesis, however, whether they can be targeted in cirrhosis treatment is unclear. Therefore, we performed three series of experiments to investigate this issue. Liver cirrhosis was induced by common bile duct ligation (BDL) in Sprague‐Dawley rats. Sham‐operated rats served as controls. Rats were randomly allocated to receive vehicle, minocycline (a nonselective MMP inhibitor) or SB‐3CT (MMP‐2 and −9 inhibitor) for 28 days in the first and second series, respectively. MMP‐9 knockout mice were used in the third series. The results showed that minocycline ameliorated portal hypertension, hemodynamic abnormalities, reduced collateral shunting, mesenteric vascular density, plasma VEGF level and alleviated liver fibrosis. SB‐3CT attenuated portal hypertension, hemodynamic derangements, reduced shunting, mesenteric vascular density, mesenteric VEGF protein expression, and liver fibrosis. Knockout BDL mice had significantly alleviated portal hypertension, liver fibrosis, liver α‐SMA and mesenteric eNOS protein expressions compared to wild‐type BDL mice. Liver SMAD2 phosphorylation was down‐regulated in all series with MMP inhibition or knock‐out. In conclusion, MMP‐9 inhibition or deletion ameliorated the severity of cirrhosis, portal hypertension, and associated derangements. MMP‐9 may be targeted in the treatment of liver cirrhosis.

Peritoneal-Membrane Characteristics and Hypervolemia Management in Peritoneal Dialysis: A Randomized Control Trial

Excessive bodily-fluid retention is the major cause of hypertension and congestive heart failure in patients with end-stage renal disease. Compared to hemodialysis, peritoneal dialysis (PD) uses the abdominal peritoneum as a semipermeable dialysis membrane, providing continuous therapy as natural kidneys, and having fewer hemodynamic changes. One major challenge of PD treatment is to determine the dry weight, especially considering that the speed of small solutes and fluid across the peritoneal membrane varies among individuals; considerable between-patient variability is expected in both solute transportation and ultrafiltration capacity. This study explores the influence of peritoneal-membrane characteristics in the hydration status in patients on PD. A randomized control trial compares the bioimpedance-assessed dry weight with clinical judgment alone. A high peritoneal membrane D/P ratio was associated with the extracellular/total body water ratio, dialysate protein loss, and poor nutritional status in patients on PD. After a six-month intervention, patients with monthly bioimpedance analysis (BIA) assistance had better fluid (−1.2 ± 0.4 vs. 0.1 ± 0.4 kg, p = 0.014) and blood-pressure (124.7 ± 2.7 vs. 136.8 ± 2.8 mmHg, p < 0.001) control; however, hydration status and blood pressure returned to the baseline after we prolonged BIA assistance to a 3-month interval. The dry-weight reduction process had no negative effect on residual renal function or peritoneal-membrane function. We concluded that peritoneal-membrane characteristics affect fluid and nutritional status in patients on PD, and BIA is a helpful objective technique for fluid assessment for PD.

Early clinical exposure improves medical students' recognition of the need for professionalism and interprofessional collaboration

BACKGROUND

Medical students in Taiwan start their clerkship in their fifth year. A lack of early clinical exposure can mean they have a lack of medical professionalism and collaborative practice. This study investigates whether early engagement in hospital-based clinical practice could improve their understanding of these requirements.

METHODS

From 2017 to 2019, a total of 59 medical students at the end of their third year joined a 2-week summer camp at the hospital. Every participant was assigned to work with one patient and they accompanied this patient throughout their hospital course. The students were also asked to interview other medical professionals within the hospital and to write up interview reports. In addition, they had to complete pre- and postcamp questionnaires which included 10 questions to evaluate their recognition of professionalism, doctor-patient relationships, and interprofessional collaboration. Answers to the questions were all rated using a 5-score Likert scale.

RESULTS

The total postcamp Likert scores were significantly increased after the 2-week training camp compared with the precourse scores (pre- vs postcourse: 44.08 ± 0.45 vs 46.66 ± 0.33, p < 0.001). In addition, the students' recognition of medical professionalism, the importance of communication with patients, and their respect for other medical professionals were significantly improved after the 2-week training.

CONCLUSION

Our data showed that early clinical exposure through a preclerkship summer camp can help medical students improve their recognition of medical professionalism and interprofessional collaboration.

Role-play of real patients improves the clinical performance of medical students

BACKGROUND

This study aimed to evaluate whether the role-play (RP) of real patients by medical students as part of interactive clinical reasoning training can improve medical students' clinical performance.

METHODS

A total of 26 medical students volunteered to portray real patients within this program and were treated as the RP group while the other 72 students as the non-RP group. In the interactive morning meeting, the medical students practiced how to approach the RP student as if they were encountering a real patient. All students were evaluated by mini-clinical evaluation exercises (mini-CEX) before and after this training program.

RESULTS

We found that all students had an increased total mini-CEX score after 4-week training, especially for interviewing skills. Notably, after training, the RP students had significantly elevated total mini-CEX scores (51.23 ± 1.06 vs 53.12 ± 1.11, p = 0.028), and for counselling (7.15 ± 0.14 vs 7.54 ± 0.18, p = 0.015) and overall clinical competence (7.27 ± 0.15 vs 7.65 ± 0.16, p = 0.030). In contrast, the non-RP students had lower scores compared with the RP group, as revealed by both the pre- and post-training tests. Moreover, their mini-CEX scores were not improved after training.

CONCLUSION

Medical students who were motivated to RP real patients had better performance scores than those who did not. In addition, RP can enhance their counselling skills and clinical competences.

Sustained effects of faculty leadership development modules for clinical instructors of core competences education in Taiwan: a four-year explanatory case study

BACKGROUND

The Accreditation Council for Graduate Medical Education (ACGME) core competencies (CC) in general medicine-based primary care are essential for junior medical trainees. In this country, a regular faculty development (FD) program aimed at training faculty in instructing (teaching and assessing) these CC had operated. However, leadership was not emphasized. In a new intervention module, the roles and associated responsibilities of clinical instructors to conduct, design, and lead CC-based education were emphasis.

AIMS

This follow-up explanatory case study compares the effectiveness of intervention module with that of the previous regular module.

METHODS

The regular group (n = 28) comprised clinical instructors who participated in the FD module during the 2013-2014 year while the intervention group (n = 28) was composed of 2015-2016 participants. Prior to the formal (hands-on) training, participants in the intervention group were asked to study the online materials of the regular module. These participants then received a 30-h hands-on training in conducting, designing, and leading skills. Finally, they prepared a 10-h reflective end-of-module presentation of their real-world practices.

RESULTS

Following the training, a higher degree improvement in participants self-reported familiarity with CC education, self-confidence in their ability to deliver CC education and sustained involve CC education were noted among the intervention FD group, compared with the regular FD group. In the intervention group, senior academicians (associate and full professor) are more substantially involved in designing and leading CC-based courses than junior academicians (lecturers and assistant professors). Among non-teaching award winners of in the intervention FD group, the follow-up degree of sustained involvement in delivering, designing and leading CC-based courses was significantly higher than that of the regular group.

CONCLUSIONS

Our study demonstrated that leadership training in the intervention FD modules substantially motivated clinical instructors to become leaders in CC education.

NAFLD Aggravates Septic Shock Due to Inadequate Adrenal Response and 11β-HSDs Dysregulation in Rats

Background: Non-alcoholic fatty liver disease (NAFLD) is linked with metabolic syndrome. Previous studies showed that obesity may disrupt adrenal function and adversely affect its counter-regulations against shock. This study hence evaluated adrenal function abnormalities in NAFLD with shock. Methods: Sprague-Dawley rats were fed with regular chow-diet (control) or high fat diet (HFD, 60% energy derived from fat). Blood tests were performed at the end of the 4th, 6th and 8th week, respectively. Experiments were performed at the end of the 8th week. Results: HFD rats developed NAFLD. HFD rats had 27% and 51% increase in plasma corticosterone at the 6th and 8th week in usual status. However, HFD rats had 5 times more reduction of mean arterial pressure in response to lipopolysaccharide-induced sepsis as compared to control rats. The corticosterone increment ratio was also lower in HFD rats, even after ACTH administration. 11β-HSD system tended to generate more corticosterone in HFD rats under hemodynamic stable status without shock and the trend was lost in HFD rats with septic shock. Conclusion: Rats with NAFLD had profound septic shock due to inadequate corticosterone response. This is, at least partly, due to 11β-HSDs dysregulation in sepsis.

Dual Angiotensin Receptor and Neprilysin Inhibitor Ameliorates Portal Hypertension in Portal Hypertensive Rats

Background: Portal hypertension is characterized by exaggerated activation of the renin-angiotensin-aldosterone axis. Natriuretic peptide system plays a counter-regulatory role, which is modulated by neprilysin. LCZ696 (sacubitril/valsartan) is a dual angiotensin receptor and neprilysin inhibitor. This study evaluated the effect of LCZ696 on portal hypertensive rats. Methods: Portal hypertension was induced by partial portal vein ligation (PVL) in rats. LCZ696, valsartan (angiotensin receptor blocker), or normal saline (control) was administered in PVL rats for 10 days. Then, hemodynamic and biochemistry data were obtained. The hepatic histology and protein expressions were surveyed. On the parallel groups, the portal-systemic shunting degrees were determined. Results: LCZ696 and valsartan reduced mean arterial pressure and systemic vascular resistance. LCZ696, but not valsartan, reduced portal pressure in portal hypertensive rats (control vs. valsartan vs. LCZ696: 15.4 ± 1.6 vs. 14.0 ± 2.3 vs. 12.0 ± 2.0 mmHg, control vs. LCZ696: P < 0.05). LCZ696 and valsartan improved liver biochemistry data and reduced intrahepatic Cluster of Differentiation 68 (CD68)-stained macrophages infiltration. Hepatic endothelin-1 (ET-1) protein expression was downregulated by LCZ696. The portal-systemic shunting was not affected by LCZ696 and valsartan. Conclusion: LCZ696 and valsartan reduced mean arterial pressure through peripheral vasodilation. Furthermore, LCZ696 significantly reduced portal pressure in PVL rats via hepatic ET-1 downregulation.

A high-dose rapamycin treatment alleviates hepatopulmonary syndrome in cirrhotic rats

BACKGROUND

Rapamycin is a type of immunosuppressive agent that acts through inhibition of mammalian target of rapamycin (mTOR). Hepatopulmonary syndrome (HPS) is a lethal complication in cirrhotic patients. It is characterized by hypoxia and increased intrapulmonary shunts, in which pulmonary inflammation and angiogenesis play important roles. The current study aimed to evaluate the effect of rapamycin on HPS using the experimental model of common bile duct ligation (CBDL)-induced cirrhosis in rats.

METHODS

The rats received low-dose (0.5 mg/kg), high-dose (2 mg/kg) rapamycin, or vehicle from the 15th to the 28th day post CBDL. Then the mortality rate, hemodynamics, biochemistry parameters, arterial blood gas and plasma levels of vascular endothelial growth factor (VEGF) and tumor necrosis factor (TNF)-α were evaluated on the 28th day post CBDL. Pulmonary histopathological stains were performed, and protein expression was examined. In parallel groups, the intrapulmonary shunts of CBDL rats were measured.

RESULTS

Compared with the control, a high-dose rapamycin treatment decreased portal pressure and improved hypoxia in CBDL rats. It also reduced the plasma level of VEGF and TNF-α and decreased intrapulmonary shunts. Meanwhile, it ameliorated pulmonary inflammation and angiogenesis and downregulated the protein expression of mTOR, P70S6K, nuclear factor kappa B (NFκB), VEGF, and VEGF receptor 2. In contrast, low-dose rapamycin did not attenuate intrapulmonary shunts despite ameliorating portal hypertension.

CONCLUSION

High-dose rapamycin ameliorates HPS in cirrhotic rats as evidenced by the alleviated hypoxia and decreased intrapulmonary shunts. Downregulation of the mTOR/P70S6K, NFκB, and VEGF signaling pathways might play a key role.

Trios-OSCE-based simulation course enhances the subcompetency of emergency-stabilization for postgraduate year-1 residents

BACKGROUND

For patient safety, this study aims to evaluate the effectiveness of additional objective structured clinical examination (OSCE)-based medical simulation courses to establish the "emergency-stabilization" subcompetency of postgraduate first year (PGY-1) residents.

METHODS

In the simulation course, trainees were randomly divided into three groups: intervention, regular, and control group as Trios-OSCE trainees, Single-OSCE trainees, or OSCE observers (feedback-givers) after attending the pre-OSCE common simulation workshop. Three PGY-1 residents rotated through the Trios OSCE long-station together, while single PGY-1 residents rotated through regular OSCE alone and the control group gave feedback after observation of their peers' OSCE performance. Using Queen's simulation assessment tool, either in Trios-OSCE or Single-OSCE, performance levels were rated as either inferior, novice, competent, advanced or superior in the "therapeutic actions" and "communication" domains. The "overall performances" of all trainees were graded by qualified assessors, experienced facilitators, and standardized senior nurse.

RESULTS

The proportion of "overall performance" of trainee's, rated by an experienced facilitator as "above competent level," was significantly higher in intervention group A than in regular group B. After training, the degree of increase in self-efficacy scores was higher among the intervention group than the regular and control groups. In the follow-up stage, a trend of increasing self-efficacy scores was noted in both the interventional and regular groups. For all trainees among the three groups, high postcourse value scores confirm that the new Trios-OSCE model meets the needs of trainees and also motivates the self-directed learning and self-reflection of trainees.

CONCLUSION

Our results provide initial evidence that the new emergency-stabilization-enhanced Trios-OSCE-based medical simulation course including the additional training capacity offered by adding an observer group had positive effects on PGY-1 residents' self-efficacy and clinical transfer.

Effect of ivabradine, a funny current inhibitor, on portal hypertensive rats

BACKGROUND

Ivabradine is a funny current inhibitor which is administered to patients with congestive heart failure to reduce their heart rate (HR) and attenuate oxidative stress. Chronic liver diseases are characterized by portal hypertension and hyperdynamic circulation with tachycardia. The present study aimed to investigate the effect of ivabradine on portal hypertension.

METHODS

Male Sprague-Dawley rats received partial portal vein ligation (PVL) to induce portal hypertension. The PVL rats were randomly allocated to receive either vehicle or ivabradine treatment for 10 days. Then the hemodynamic data were collected. The levels of oxidative stress markers and the mRNA expression of nitric oxide synthase (NOS) were measured in the collateral vessel, the superior mesentery artery and the liver. In addition, the collateral vascular responsiveness to arginine vasopressin (AVP) was examined in the ivabradine-treated and vehicle-treated PVL rats.

RESULTS

Treatment with ivabradine significantly lowered the HR (174 ± 20 vs. 374 ± 9 beats/min; p < 0.001) and the superior mesentery arterial flow (SMAf) (6.6 ± 0.3 vs. 9.1 ± 0.7 mL/min/100 g BW; p = 0.005) of the PVL rats compared with the control group. The mean arterial pressure, cardiac index, systemic vascular resistance, portal pressure and serum levels of oxidative stress markers were not significantly affected by ivabradine treatment. In addition, the NOS expression and collateral vascular responsiveness to AVP were not significantly influenced by ivabradine treatment, either.

CONCLUSION

Ivabradine reduced the HR and SMAf in PVL rats, which alleviated the hyperdynamic circulatory state and splanchnic hyperemia of portal hypertension. However, whether these effects would help alleviate portal hypertension-related complications requires further clinical investigations.

Endotoxemia-enhanced renal vascular reactivity to endothelin-1 in cirrhotic rats

Hepatorenal syndrome (HRS), a severe complication of advanced cirrhosis, is defined as hypoperfusion of kidneys resulting from intense renal vasoconstriction in response to generalized systemic arterial vasodilatation. Nevertheless, the mechanisms have been barely investigated. Cumulative studies demonstrated renal vasodilatation in portal hypertensive and compensated cirrhotic rats. Previously, we identified that blunted renal vascular reactivity of portal hypertensive rats was reversed after lipopolysaccharide (LPS). This study was therefore conducted to delineate the sequence of renal vascular alternation and underlying mechanisms in LPS-treated cirrhotic rats. Sprague-Dawley rats were randomly allocated to receive sham surgery (Sham) or common bile duct ligation (CBDL). LPS was induced on the 28th day after surgery. Kidney perfusion was performed at 0.5 or 3 h after LPS to evaluate renal vascular response to endothelin-1 (ET-1). Endotoxemia increased serum ET-1 levels ( P < 0.0001) and renal arterial blood flow ( P < 0.05) in both Sham and CBDL rats. CBDL rats showed enhanced renal vascular reactivity to ET-1 at 3 h after LPS ( P = 0.026). Pretreatment with endothelin receptor type A (ET_A) antagonist abrogated the LPS-enhanced renal vascular response in CBDL rats ( P < 0.001). There were significantly lower inducible nitric oxide synthase (iNOS) expression but higher ET_A and phosphorylated extracellular signal-regulated kinase (p-ERK) expressions in renal medulla of endotoxemic CBDL rats ( P < 0.05). We concluded that LPS-induced renal iNOS inhibition, ET_A upregulation, and subsequent ERK signaling activation may participate in renal vascular hyperreactivity in cirrhosis. ET-1-targeted therapy may be feasible in the control of HRS. NEW & NOTEWORTHY Hepatorenal syndrome (HRS) occurred in advanced cirrhosis after large-volume paracentesis or bacterial peritonitis. We demonstrated that intraperitoneal lipopolysaccharide (LPS) enhanced renal vascular reactivity to endothelin-1 (ET-1) in cirrhotic rats, accompanied by inducible nitric oxide synthase inhibition, endothelin receptor type A (ET_A) upregulation, and subsequent extracellular signal-regulated kinase activation in renal medulla. Pretreatment with ET_A antagonist abrogated the LPS-enhanced renal vascular response in common bile duct ligation rats. These findings suggest that further clinical investigation of ET-1-targeted therapy may be feasible in the control of HRS.

Nucleos(t)ide Analogs Do Not Independently Influence Hepatic Fibrosis and Portal Hypertension beyond Viral Suppression in CBDL-Induced Cirrhotic Rat

Chronic hepatitis is the major cause of liver cirrhosis and portal hypertension. Several factors affect portal pressure, including liver fibrosis, splanchnic vasodilatation, and pathologic angiogenesis. Nucleos(t)ide analogs (NUCs), the oral antiviral agents, effectively attenuate chronic hepatitis B-related liver cirrhosis and portal hypertension via viral suppression and alleviation of hepatitis. On the other hand, NUCs affect tumor necrosis factor (TNF)-α, vascular endothelial growth factor (VEGF), and nitric oxide, which participate in fibrogenesis, vasodilatation, and angiogenesis. However, whether NUCs independently influence liver fibrosis and portal hypertension beyond viral suppression is unknown. This study thus aimed to evaluate the influences of three frequently used NUCs in rats with nonviral cirrhosis. Male Sprague-Dawley rats received common bile duct ligation (CBDL) to induce cholestatic cirrhosis and portal hypertension. The rats were randomly allocated into four groups, treated by mouth with lamivudine (30 mg/kg per day), entecavir (0.09 mg/kg per day), tenofovir (50 mg/kg per day), or distilled water (vehicle control) from the 15th day after CBDL. On the 29th day, liver cirrhosis- and portal hypertension-related parameters were evaluated. The results showed that chronic NUCs treatment did not affect hemodynamic parameters, plasma TNF-α concentration, and hepatic fibrogenesis protein expressions in rats with nonviral cirrhosis. Though the mesenteric VEGF receptor 2 phosphorylation was downregulated in NUCs-treated groups, the splanchnic angiogenesis was not influenced. In conclusion, lamivudine, entecavir, and tenofovir had no additional effects on liver cirrhosis and portal hypertension in rats with nonviral cirrhosis.

Peer-assisted learning model enhances clinical clerk's procedural skills

BACKGROUND

Failure to transfer procedural skills learned in a laboratory to the bedside is commonly due to a lack of peer support/stimulation. A digital platform (Facebook) allows new clinical clerks to share experiences and tips that help augment their procedural skills in a peer-assisted learning/teaching method. This study aims to investigate the effectiveness of the innovation of using the digital platform to support the transfer of laboratory-trained procedural skills in the clinical units.

METHODS

Volunteer clinical clerks (n = 44) were enrolled into the peer-assisted learning (PAL) group, which was characterized by the peer-assisted learning of procedural skills during their final 3-month clinical clerkship block. Other clerks (n = 51) did not join the procedural skills-specific Facebook group and served as the self-directed learning regular group. The participants in both the PAL and regular groups completed pre- and post-intervention self-assessments for general self-assessed efficiency ratings (GSER) and skills specific self-assessed efficiency ratings (SSSER) for performing vein puncture, intravenous (IV) catheter and nasogastric (NG) tube insertion. Finally, all clerks received the post-intervention 3-station Objective Structured Clinical Skills Examination (OSCE) to test their proficiency for the abovementioned three procedural skills.

RESULTS

Higher cumulative numbers of vein punctures, IV catheter insertions and NG tube insertions at the bedside were carried out by the PAL group than the regular group. A greater improvement in GSERs and SSSERs for medical procedures was found in the PAL group than in the regular group. The PAL group obtained higher procedural skills scores in the post-intervention OSCEs than the regular group.

CONCLUSION

Our study suggested that the implementation of a procedural skill-specific digital platform effectively helps clerks to transfer laboratory-trained procedural skills into the clinical units. In comparison with the regular self-directed learning group, the peer-assisted learning characteristics of Facebook give additional benefits to the PAL group by enhancing their procedural skills.

The effects of proton pump inhibitor on hepatic vascular responsiveness and hemodynamics in cirrhotic rats

BACKGROUND

Liver cirrhosis is associated with increased intrahepatic resistance due to hepatic fibrosis and exaggerated vasoconstriction. Recent studies have indicated that proton pump inhibitors (PPIs), in addition to acid suppression, modulate vasoactive substances and vasoresponsiveness. PPIs are frequently prescribed in patients with cirrhosis due to a higher prevalence of peptic ulcers, however other impacts are unknown.

METHODS

Liver cirrhosis was induced in Sprague-Dawley rats with common bile duct ligation (BDL). On the 29th day after BDL and after hemodynamic measurements, the intrahepatic vascular responsiveness to high concentrations of endothelin-1 (ET-1) was evaluated after preincubation with (1) Krebs solution (vehicle), (2) esomeprazole (30 μM), or (3) esomeprazole plus N^ω-nitro l-arginine (NNA, a non-selective NO synthase (NOS) inhibitor, 10^-4 M). After perfusion, the hepatic protein expressions of endothelial NOS (eNOS), inducible NOS (iNOS), cyclooxygenase (COX)-1, COX-2, endothelin-1, DDAH-1 (dimethylarginine dimethylaminohydrolase-1, ADMA inhibitor), DDAH-2, ADMA (asymmetrical dimethyl arginine, NOS inhibitor) were evaluated. In the chronic model, the BDL rats received (1) vehicle; or (2) esomeprazole (3.6 mg/kg/day, oral gavage) from the 1st to 28th day after BDL. On the 29th day and after hemodynamic measurements, plasma liver biochemistry and liver fibrosis were evaluated.

RESULTS

Esomeprazole did not affect hepatic ET-1 vasoresponsiveness. The hepatic protein expressions of the aforementioned factors were not significantly different among the groups. There were no significant differences in hemodynamics, liver biochemistry and hepatic fibrosis after chronic esomeprazole administration.

CONCLUSION

PPIs did not affect hepatic vasoresponsiveness or the release of vasoactive substances. Furthermore, they did not influence hemodynamics, liver biochemistry or severity of hepatic fibrosis in the cirrhotic rats.

Metformin reduces intrahepatic fibrosis and intrapulmonary shunts in biliary cirrhotic rats

BACKGROUND

Liver fibrosis causes portal hypertension which dilates collateral vasculature and enhances extra-hepatic angiogenesis including intrapulmonary shunts, which subsequently complicates with hepatopulmonary syndrome. Metformin is an anti-diabetic agent which possesses anti-inflammation and anti-angiogenesis properties. This study evaluated the effect of metformin treatment on liver and lung in a non-diabetic rat model with biliary cirrhosis induced via common bile duct ligation (CBDL).

METHODS

CBDL rats were fed with metformin 150 mg/kg/day during the 8th-28th day post operation. The hemodynamic and biochemistry parameters were tested, and blood gas analysis was performed. The liver and lung were dissected for protein analysis and immuno-histochemical stains. Intrapulmonary shunting degree was determined using color microsphere method.

RESULTS

Metformin treatment neither induced obvious hypoglycemic event nor altered hemodynamics in cirrhotic rats. The plasma levels of alanine aminotransferase were significantly reduced by metformin (control vs. metformin: 269 ± 56 vs. 199 ± 21 IU/L, P = 0.02). Sirius Red stains and CD-68 stains showed that metformin reduced intrahepatic fibrosis and CD-68-positive macrophages. Metformin did not influence hypoxia and intrapulmonary angiogenesis; however, it significantly reduced intrapulmonary shunts (31.7 ± 10.1 vs. 15.0 ± 6.6%, P = 0.006.). Furthermore, metformin reduced the protein expressions of COX-2 and PI3K in liver and COX-1 in lung.

CONCLUSION

Metformin reduced liver injury and improved hepatic fibrosis in cirrhotic rats. It also attenuated the intrapulmonary shunts. However, the effects of metformin on pulmonary angiogenesis and hypoxia were insignificant.

Effects of raloxifene on portal hypertension and hepatic encephalopathy in cirrhotic rats

Raloxifene, a selective estrogen receptor modulator, has been used extensively for osteoporosis. In addition to the effect of osteoporosis treatment, emerging evidences show that raloxifene affects the vascular function in different tissues. Cirrhosis is characterized with portal hypertension and complicated with hepatic encephalopathy. Portal hypertension affects portal-systemic shunt which leads to hepatic encephalopathy that the vascular modulation might influence severity of hepatic encephalopathy. Herein, we evaluated the impact of raloxifene on bile duct ligation (BDL)-induced cirrhotic rats. The female Sprague-Dawley rats received BDL plus ovariectomy or sham-operation. Four weeks later, rats were divided into 2 subgroups respectively to receive of raloxifene (10mg/kg/day) or saline (vehicle) for 14 days. On the 43th day, motor activities and hemodynamic parameters were measured. Hepatic and vascular mRNA and protein expressions were determined. The histopathological change of liver was examined. We found that the liver biochemistry, ammonia level and motor activity were similar between cirrhotic rats with or without raloxifene administration. The hemodynamic parameters were not significantly different except that raloxifene reduced portal venous inflow. Raloxifene exacerbated hepatic fibrosis and up-regulated hepatic endothelin-1 and cyclooxygenase 2 protein expressions. In addition, raloxifene modulated the mRNA expressions of endothelial nitric oxide synthase, cyclooxygenase and endothelin-1 in the superior mesenteric artery and collateral vessel. In conclusion, raloxifene aggravates hepatic fibrosis and decreases portal venous inflow in cirrhotic rats without adversely affecting portal hypertension and hepatic encephalopathy. The modulation of hepatic and vascular endothelin-1, endothelial nitric oxide synthase and cyclooxygenase expressions may play a role in the mechanism.

Voluntary attendance of small-group brainstorming tutoring courses intensify new clerk's "excellence in clinical care": a pilot study

BACKGROUND

Clerkship provides a unique way of transferring the knowledge and skills gathered during medical school's curriculum into real-ward clinical care environment. The annual program evaluation has indicated that the training of clerks in diagnostic and clinical reasoning skills needed to be enhanced. Recently, "clinical excellence" program have been promoted in our institution to augment the excellence in clinical care of new clerks. Current study aims to evaluate whether this pilot program improve the "clinical excellence" of new clerks.

METHODS

In a pilot study, groups of new clerks in years 2013 and 2014 voluntarily attended either a small-group brainstorming course or a didactic classroom tutoring courses as part of their 3-month internal medicine clinical rotation block. A third group of new clerks did not join either of the above courses and this group served as the control group. Pre-block/post-block self-assessment and post-block 5-station mini-Objective Subjective Clinical Examinations (OSCEs) were used to evaluate the effectiveness of these two additional courses that trained diagnostic and clinical reasoning skills.

RESULTS

Overtime, the percentages of new clerks that attended voluntarily either the small-group brainstorming or classroom tutoring courses were increased. Higher post-block self-assessed diagnostic and clinical reasoning skill scores were found among individuals who attended the small-group brainstorming courses compared to either the didactic group or the control group. In a corresponding manner, the small-group brainstorming group obtained higher summary OSCE_diag and OSCE_reason scores than either the didactic group or control group. For all basic images/laboratory OSCE stations, the individual diagnostic skill (OSCE_diag) scores of the small-group brainstorming group were higher than those of the didactic group. By way of contrast, only the clinical reasoning skill (OSCE_reason) scores of the basic electrocardiogram and complete blood count + biochemistry OSCE station of thesmall-group brainstorming group were higher than those of the didactic group. Among the small-group brainstorming group, clerks with higher cumulative learning hours (>30-h) had significant higher OSCE_diag and OSCE_reason scores (>400) than those with less cumulative learning hours.

CONCLUSION

Our pilot study provides a successful example of the use of a small-group tutoring courses for augmenting the diagnostic and clinical reasoning skills of new clerks. The positive results obtained during the initial 2-year long pilot "clinical excellence" program have encouraged the formal implementation of this course as part of the clerkship curriculum.

Endothelin receptor blockers reduce shunting and angiogenesis in cirrhotic rats

BACKGROUND

Angiogenesis plays a pivotal role in splanchnic hyperaemia and portosystemic collateral formation in cirrhosis. Endothelin-1 (ET-1), an endothelium-derived vasoconstrictor, has also been implicated in the pathogenesis of cirrhosis and portal hypertension.

DESIGN

This study aimed to survey the influences of ET-1 in cirrhosis-related angiogenesis. Common bile duct ligation was performed on Spraque-Dawley rats to induce cirrhosis. Since the 14th day after the operation, rats randomly received distilled water (DW, control), bosentan [a nonselective ET receptor (ETR) blocker] or ambrisentan (a selective ETA R blocker) for 4 weeks. On the 43rd day, portal and systemic haemodynamics, liver biochemistry, portosystemic shunting degree, mesenteric vascular density, mRNA and/or protein expressions of relevant angiogenic factors were evaluated.

RESULTS

In cirrhotic rats, bosentan significantly reduced portal pressure. Ambrisentan did not influence haemodynamics and liver biochemistry. Both of them significantly improved the severity of portosystemic collaterals and decreased the mesenteric vascular density. Compared with the DW-treated cirrhotic rats, splenorenal shunt and mesenteric inducible nitric oxide synthase (iNOS), cyclooxygenase 2 (COX2), vascular endothelial growth factor mRNA expressions and mesenteric iNOS, COX2, VEGF, phospho-VEGF receptor 2, Akt and phospho-Akt protein expressions were down-regulated in both groups.

CONCLUSIONS

In rats with liver cirrhosis, both nonselective and selective ETA R blockade ameliorate the severity of portosystemic shunting and mesenteric angiogenesis via the down-regulation of VEGF pathway and relevant angiogenic factors. ET receptors may be targeted to control the severity of portosystemic collaterals and associated complications in cirrhosis.

Daptomycin antibiotic lock therapy for hemodialysis patients with Gram-positive bloodstream infections following use of tunneled, cuffed hemodialysis catheters: retrospective single center analysis

Catheter-related blood stream infection (CRBSI) is a major complication in hemodialysis patients. We assessed the efficacy of systemic daptomycin (DPT) plus DPT antibiotic lock therapy (DPT-ALT) for catheter salvage in patients with Gram-positive CRBSIs. This is a retrospective study of hemodialysis patients with tunneled and cuffed hemodialysis catheters. All patients were from a single institution in Taipei and received systemic DPT plus DPT-ALT for the treatment of Gram-positive CRBSI. Successful resolution of CRBSI was implemented. Resolution of fever within 48 hours, negative result of repeated blood cultures after resolution of fever, no clinical evidence of CRBSI relapse and no need for catheter removal were measured. Fifteen hemodialysis patients received DPT-ALT for CRBSI, nine with coagulase-negative Staphylococcus (CONS), two with methicillin-resistant Staphylococcus aureus (MRSA), three with methicillin-sensitive Staphylococcus aureus (MSSA) and one with polymicrobial infections. Systemic DPT plus DPT-ALT cured 11 patients (73.3%). Treatment failed in all three MRSA cases (two with MRSA and one with MRSA + Enterococcus faecalis). Retrospective design and small sample size were the limitations of this study. Systemic DPT plus DPT-ALT appears to be a promising treatment for CRBSI from CONS and MSSA, but not for MRSA CRBSI. Systemic DPT plus DPT-ALT should be considered for patients with CRBSIs caused by certain species.

Self- and rater-assessed effectiveness of "thinking-aloud" and "regular" morning report to intensify young physicians' clinical skills

BACKGROUND

This study compared the effects of the "thinking aloud" (TA) morning report (MR), which is characterized by sequential and interactive case discussion by all participants, with "regular" MR for clinical skill training of young physicians.

METHODS

Between February 2011 and February 2014, young physicians [including postgraduate year-1 (PGY1) residents, interns, and clerks) from our hospital were sequentially enrolled and followed for 3 months. The self- and rater-assessed educational values of two MR models for building up clinical skills of young physicians were compared.

RESULTS

The junior (intern and clerk) attendees had higher self-assessed educational values scores and reported post-training application frequency of skills trained by TA MR compared with the senior (PGY1 resident) attendees. Higher average and percentage of increased overall rater-assessed OSCE scores were noted among the regular MR senior attendees and TA MR junior attendees than in their corresponding control groups (regular MR junior attendees and TA MR senior attendees). Interestingly, regular MRs provided additional beneficial effects for establishing the "professionalism, consulting skills and organization efficiency" aspects of clinical skills of senior/junior attendees. Moreover, senior and junior attendees benefited the most by participating in seven sessions of regular MR and TA MR each month, respectively.

CONCLUSION

TA MR effectively trains junior attendees in basic clinical skills, whereas regular MR enhances senior attendees' "work reports, professionalism, organizational efficiency, skills in dealing with controversial and professional issues." Undoubtedly, all elements of the two MR models should be integrated together to ensure patient safety and good discipline among young physicians.

A model of four hierarchical levels to train Chinese residents' teaching skills for "practice-based learning and improvement" competency

OBJECTIVES

The current study focused on validating a protocol for training and auditing the resident's practice-based learning and improvement (PBLI) and quality improvement (QI) competencies for primary care.

METHODS

Twelve second-year (R2), 12 first-year (R1) and 12 postgraduate year-1 residents were enrolled into group A, B and C, respectively, as trainees. After three training protocols had been completed, a writing test, self-assessed questionnaire and mini-OSTE and end-of-rotation assessment were used in auditing the PBLI competency, performance and teaching ability of trainees.

RESULTS

Baseline expert-assessed PBLI and QI knowledge application tool writing scores were low for the R1 and R2 residents. After three training protocols, PBLI and QI proficiencies, performance and teaching abilities were improved to similar levels cross the three training levels of residents based on the expert-assessed writing test-audited assessments and on the faculty and standardized clerk-assessed end-of-rotation-/mini-OSTE-audited assessments.

CONCLUSION

The different four-level hierarchical protocols used to teach group A, B and C were equally beneficial and fitted their needs; namely the different levels of the trainees. Specifically, each level was able to augment their PBLI and QI proficiency. This educational intervention helps medical institutions to train residents as PBLI instructors.

The Beneficial Effects of P2X7 Antagonism in Rats with Bile Duct Ligation-induced Cirrhosis

Splanchnic angiogenesis in liver cirrhosis often leads to complications as gastroesophageal variceal hemorrhage and the treatment efficacy is adversely affected by poor portal-systemic collateral vasoresponsiveness related to nitric oxide (NO). Purinergic receptor subtype P2X7 participates in the modulation of inflammation, angiogenesis, fibrogenesis and vasoresponsiveness, but the relevant influence in cirrhosis is unknown. Common bile duct-ligated (CBDL) or sham-operated Spraque-Dawley rats received brilliant blue G (BBG, a P2X7 antagonist and food additive) or vehicle from the 15th to 28th day after operations, then hemodynamics, mesenteric angiogenesis, portal-systemic shunting, liver fibrosis, and protein expressions of angiogenic and fibrogenic factors were evaluated. The influence of oxidized ATP (oATP, another P2X7 receptor antagonist) on the collateral vasoresponsiveness to arginine vasopressin (AVP) was also surveyed. BBG decreased superior mesenteric artery (SMA) flow, portal-systemic shunting, mesenteric vascular density, and mesenteric protein expressions of vascular endothelial growth factor (VEGF), VEGF receptor 2 (VEGFR2), phospho (p)-VEGFR2, platelet-derived growth factor (PDGF), PDGF receptor beta (PDGFRβ), cyclooxygenase (COX)-1, COX-2, and endothelial NO synthase (eNOS) in CBDL rats. BBG also ameliorated liver fibrosis and down-regulated hepatic interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), PDGF, IL-1β, transforming growth factor-beta (TGF-β), p-extracellular-signal-regulated kinases (ERK), and alpha-smooth muscle actin (α-SMA) expressions in CBDL rats. The collateral vasocontractility to AVP was enhanced by oATP. oATP down-regulated eNOS, inducible NOS (iNOS), VEGF, Akt, p-Akt, and nuclear factor-kappa B (NF-κB) expressions in splenorenal shunt, the most prominent intra-abdominal collateral vessel in rodents. P2X7 antagonism alleviates splanchnic hyperemia, severity of portal-systemic shunting, mesenteric angiogenesis, liver fibrosis, and enhances portal-systemic collateral vasoresponsiveness in cirrhotic rats. P2X7 blockade may be a feasible strategy to control cirrhosis and complications.

Caffeine ameliorates hemodynamic derangements and portosystemic collaterals in cirrhotic rats

Portal hypertension (PH), a pathophysiological derangement of liver cirrhosis, is characterized by hyperdynamic circulation, angiogenesis, and portosystemic collaterals. These may lead to lethal complications, such as variceal bleeding. Caffeine has been noted for its effects on liver inflammation, fibrogenesis, and vasoreactiveness. However, the relevant influences of caffeine in cirrhosis and PH have not been addressed. Spraque-Dawley rats with common bile duct ligation-induced cirrhosis or sham operation received prophylactic or therapeutic caffeine treatment (50 mg/kg/day, the first or 15th day since operation, respectively) for 28 days. Compared to vehicle (distilled water), caffeine decreased cardiac index, increased systemic vascular resistance, reduced portal pressure (PP), superior mesenteric artery flow, mesenteric vascular density, portosystemic shunting (PSS), intrahepatic angiogenesis, and fibrosis without affecting liver and renal biochemistry. The beneficial effects were reversed by selective adenosine A1 agonist N6-cyclopentyladenosine (CPA) or A2A agonist GCS21680. Both prophylactic and therapeutic caffeine treatment decreased portal resistance and PP in thioacetamide (200mg/kg, thrice-weekly for 8 weeks)-induced cirrhotic rats. Caffeine down-regulated endothelial nitric oxide synthase, vascular endothelial growth factor (VEGF), phospho-VEGFR2, and phospho-Akt mesenteric protein expression. Caffeine adversely affected viability of hepatic stellate and sinusoidal endothelial cells, which was reversed by CPA and GCS21680. On the other hand, caffeine did not modify vascular response to vasoconstrictors in splanchnic, hepatic, and collateral vascular beds.

CONCLUSIONS

Caffeine decreased PP, ameliorated hyperdynamic circulation, PSS, mesenteric angiogenesis, hepatic angiogenesis, and fibrosis in cirrhotic rats. Caffeine may be a feasible candidate to ameliorate PH-related complications in cirrhosis.

Diabetes enhances the intrahepatic vascular response to endothelin-1 in cirrhotic rats: association with the ETA receptor and pERK up-regulation

BACKGROUND & AIMS

Cirrhosis is characterized by increased intrahepatic vascular resistance and enhanced vasocontractile responsiveness that impedes portal inflow and elevates portal pressure, in which endothelin-1 (ET-1) plays a role. Diabetes and glucose influence vasoresponsiveness but their impact on the intrahepatic vascular bed in cirrhosis is unknown. To investigate intrahepatic ET-1 vasoresponsiveness in cirrhotic rats with and without diabetes and to explore the underlying mechanisms.

METHODS

Spraque-Dawley rats received common bile-duct ligation (BDL) to induce cirrhosis. Streptozotocin was injected to induce diabetes in the BDL rats (BDL/STZ). In situ liver perfusion was performed to obtain the ET-1 concentration-response curves. The basic hemodynamics and hepatic protein expressions of ET-1 receptors, pERK, ERK, pAkt, Akt, iNOS, eNOS, peNOS and calmodulin were evaluated. The circulating concentrations of N-terminal pro-brain natriuretic peptide (NT-ProBNP), blood urea nitrogen (BUN) and creatinine were also determined.

RESULTS

Body weight, mean arterial pressure, heart rate and survival rate were significantly decreased in the BDL/STZ rats. The perfusion pressure changes in response to ET-1 were higher in the BDL/STZ group for all perfusates. ETA receptor and pERK expressions were enhanced in the BDL/STZ group. The circulating concentrations of NT-ProBNP, BUN and creatinine, as well as SMA flow, were not significantly different between the BDL and BDL/STZ groups.

CONCLUSION

Cirrhotic rats with diabetes showed higher intrahepatic ET-1 vasoresponsiveness than normoglycemic cirrhotic rats. This effect is not affected by changes in perfused glucose concentration and may be related, at least in part, to intrahepatic ETA R receptor and pERK over-expression.

Lipopolysaccharide enhanced renal vascular response to endothelin-1 through ETA overexpression in portal hypertensive rats

BACKGROUND AND AIM

Hypo-perfusion resulting from intense renal vasoconstriction is traditionally contributed to renal dysfunction in advanced liver disease, although cumulative studies demonstrated renal vasodilatation with impaired vascular contractility to endogenous vasoconstrictors in portal hypertension and compensated liver cirrhosis. The pathophysiology of altered renal hemodynamics remains unclear. This study, using a rat model of portal hypertension with superimposed endotoxemia, was designed to delineate the evolution of renal vascular reactivity and vaso-regulatory gene expression during liver disease progression.

METHODS

Rats were randomized into sham surgery (SHAM) or partial portal vein ligation (PVL). Endotoxemia was induced by intraperitoneal injection of lipopolysaccharide (LPS) on the seventh day following surgery. Isolated kidney perfusion was performed at 0.5 h or 5 h after LPS to evaluate renal vascular response to endothelin-1.

RESULTS

In contrast to impaired vascular contractility of SHAM rats, PVL rats displayed enhanced renal vascular reactivity to endothelin-1 at 5 h following endotoxemia. There were extensive upregulations of inducible nitric oxide synthase in kidney tissues of endotoxemic rats. The changes of renal endothelin receptor type A (ETA ) level paralleled with the changes of renal vascular reactivity in LPS-treated rats. Compared with SHAM rats, PVL rats showed increased renal ETA and phosphorylated extracellular-signal-regulated kinases 1/2 (p-ERK1/2) at 5 h after LPS.

CONCLUSION

LPS-induced systemic hypotension induces a paradoxical change of renal vascular response to endothelin-1 between SHAM and PVL rats. LPS-induced renal vascular hyperreactivity in PVL rats was associated with upregulation of renal ETA and subsequent activation of ERK1/2 signaling.

Effect of early and intensive continuous venovenous hemofiltration on patients with cardiogenic shock and acute kidney injury after cardiac surgery

OBJECTIVE

Continuous renal replacement therapy (CRRT) is currently the mainstay renal support for critically ill patients. However, the optimal intensity of CRRT remains debated owing to the heterogeneity of the study populations and CRRT techniques across centers. The present study investigated the beneficial effects of early and intensive continuous venovenous hemofiltration (CVVH) on patients with shock after cardiotomy.

METHODS

Patients who had received CRRT for cardiogenic shock and acute kidney injury after cardiac surgery from January 2003 to December 2007 were retrospectively recruited. They were divided into 2 groups according to the delivered dosage of hemofiltration.

RESULTS

The mean duration between intensive care unit admission and initiation of CVVH was 1.4±0.8 days. The all-cause mortality by day 30 was 73.3% and 45.4% in the low- and high-dose groups, respectively (P=.002). The corresponding in-hospital mortality rate was 82.2% and 61.8% (P=.02). No significant difference was seen in the renal recovery of the survivors between the 2 groups.

CONCLUSIONS

In patients developing postoperative cardiogenic shock and acute kidney injury after cardiac surgery, an early higher CVVH dose was associated with better in-hospital and long-term survival. Moreover, the beneficial effect of intensive treatment might be more critical in the early perioperative period.

A comorbidity index for mortality prediction in Chinese patients with ESRD receiving hemodialysis

BACKGROUND AND OBJECTIVES

Chinese patients with ESRD have different comorbidity patterns than white patients with ESRD and require a validated comorbidity index. The objective of this study was to develop a new index for mortality prediction in 2006-2009 Taiwanese incident hemodialysis patients.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Data were retrieved from 2005 to 2010 Taiwan National Health Insurance claim records, and follow-up was available until December 31, 2010. The same comorbid conditions as the US Renal Data System (USRDS) index that occurred during a 12-month period from 9 months before to 3 months after dialysis initiation were used to construct the index. Integer weight of the comorbid conditions was derived from coefficient estimates of Cox regression for all-cause mortality, and the index was internally validated. The performance of the index was assessed by discrimination, calibration, and reclassification.

RESULTS

A total of 30,303 hemodialysis patients were included in this study. The weight for individual comorbid conditions of this index differed from that of the USRDS index. The performance of this index was similar to that of USRDS and Charlson indices in terms of model fit statistics, overall predictive ability, discrimination, and calibration. Hosmer-Lemeshow test showed that all three indices demonstrated significant differences between predicted and observed mortality rates. When patients were categorized by the predicted 2.5-year survival probabilities, the index achieved a net reclassification improvement of 4.71% (P<0.001), referenced to USRDS index.

CONCLUSIONS

Compared with USRDS index, this new index demonstrated better reclassification ability, but future studies should address the clinical significance.

Selective cyclooxygenase-1 inhibition improves collateral vascular reactivity in biliary cirrhotic rats

BACKGROUND

Evidence has demonstrated that overproduction of prostacyclin (PGI2) is critical in the pathogenesis of splanchnic hyposensitivity to vasoconstrictors in the cirrhotic state. The biosynthesis of PGI2 is through cyclooxygenase (COX). This study evaluated which isoform of COX is dominant in the mechanism of collateral vascular reactivity of biliary cirrhotic rats.

METHODS

Three groups of formalin-injected common bile duct-ligated (FBDL) induced cirrhotic rats received two doses of: (1) selective COX-1 inhibitor (SC-560 2 mg/kg); (2) COX-2 inhibitor (NS-398 2 mg/kg); (3) dimethyl sulfoxide (control). Subsequently, the rats were kept in metabolic cages for 24 hours to collect urine. Thereafter, the systemic and portal hemodynamics and renal function were measured. In another series, using in-situ collateral perfusion model, the collateral vascular responses to arginine vasopressin (AVP) were measured in the subject rats after preincubation of vehicle (Krebs solution), SC-560 (5 μM) or NS-398 (10 μM).

RESULTS

The mean arterial pressure, heart rate, and portal pressure were similar among SC-560-treated, NS-398-treated, and control groups. Additionally, there was no significant difference in the calculated creatinine clearance rates among these three groups. SC-560 preincubation significantly enhanced the pressor effect of AVP at the concentration of 3M × 10(-9) M (11.0 ± 1.0 mmHg vs. 6.4 ± 0.6 mmHg, p = 0.002) in the cirrhotic rats.

CONCLUSION

There was no significant hemodynamic change and renal toxicity after acute administration of COX inhibitor in the FBDL-induced cirrhotic rats. Preincubation of selective COX-1, but not COX-2, inhibitor could enhance collateral vascular response to AVP, indicating that COX-1 plays a major role in the collateral vascular reactivity.

Diabetes diminishes the portal-systemic collateral vascular response to vasopressin via vasopressin receptor and Gα proteins regulations in cirrhotic rats

Liver cirrhosis may lead to portal-systemic collateral formation and bleeding. The hemostatic effect is influenced by the response of collateral vessels to vasoconstrictors. Diabetes and glucose also influence vasoresponsiveness, but their net effect on collaterals remains unexplored. This study investigated the impact of diabetes or glucose application on portal-systemic collateral vasoresponsiveness to arginine vasopressin (AVP) in cirrhosis. Spraque-Dawley rats with bile duct ligation (BDL)-induced cirrhosis received vehicle (citrate buffer) or streptozotocin (diabetic, BDL/STZ). The in situ collateral perfusion was done after hemodynamic measurements: Both were perfused with Krebs solution, D-glucose, or D-glucose and NaF, with additional OPC-31260 for the BDL/STZ group. Splenorenal shunt vasopressin receptors and Gα proteins mRNA expressions were evaluated. The survival rate of cirrhotic rats was decreased by STZ injection. The collateral perfusion pressure changes to AVP were lower in STZ-injected groups, which were reversed by OPC-31260 (a V2R antagonist) and overcome by NaF (a G protein activator). The splenorenal shunt V2R mRNA expression was increased while Gα proteins mRNA expressions were decreased in BDL/STZ rats compared to BDL rats. The Gαq and Gα11 mRNA expressions also correlated with the maximal perfusion pressure changes to AVP. Diabetes diminished the portal-systemic collateral vascular response to AVP in rats with BDL-induced cirrhosis, probably via V2 receptor up-regulation and Gα proteins down-regulation.

Effects of simvastatin on the portal-systemic collateral vascular response to endothelin-1 and shunting degree in portal hypertensive rats

OBJECTIVE

Endothelin-1 (ET-1) exerts vasoconstrictive effect on portal-systemic collateral vascular bed of portal hypertensive rats. Statins are lipid-lowering agents with nitric oxide (NO)-related vasodilatory effects. Considering NO-associated vascular hyporesponsiveness to vasoconstrictors and shunting formation in portal hypertension, this study investigated the effects of simvastatin on 1) the portal-systemic collateral vascular responsiveness to ET-1 and 2) the portal-systemic shunting degree.

MATERIALS/METHODS

Portal hypertension was induced by partial portal vein ligation (PVL) in Sprague-Dawley rats. Simvastatin (20 mg/kg/day) or distilled water (control) was randomly administered by oral gavage since 2 days prior to until 7 days after PVL. Systemic and portal hemodynamics were measured on the 8th day. In another series, collateral perfusion with Krebs solution at different flow rates was performed to get flow-pressure curves which serve as an index of shunting degree. To survey the direct vascular effect, PVL rats randomly underwent preincubation with 1) Krebs solution, that is, the control group; or Krebs solution plus 2) simvastatin; 3) simvastatin + N (ω)-nitro-L-arginine (NNA, a NO synthase inhibitor); 4) simvastatin + indomethacin (a cyclooxygenase inhibitor), followed by ET-1 to evaluate the collateral vascular responsiveness.

RESULTS

Chronic simvastatin treatment significantly reduced portal pressure. The flow-pressure curves were similar between two groups. Simvastatin preincubation reduced collateral perfusion pressure changes to ET-1 (p < 0.05), which were partially reversed by NNA (p < 0.05), but not by indomethacin. Conclusions. Chronic simvastatin treatment significantly improved portal hypertension. The effect was at least partially exerted by decreased portal-systemic collateral vascular resistance through NO-mediated vascular hyporesponsiveness. The severity of portal-systemic collaterals was not influenced by simvastatin.

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.

Peritoneal dialysis as compared with hemodialysis is associated with higher overhydration but non-inferior blood pressure control and heart function

BACKGROUND/AIMS

Fluid overload is an important factor causing cardiovascular complications in dialysis patients. We compared fluid status, blood pressure (BP) and heart function between peritoneal dialysis (PD) patients and hemodialysis (HD) patients.

METHODS

We recruited 94 PD and 75 HD patients in our hospital. Fluid status was assessed by bioimpedance spectroscopy. Home BP was recorded. Use of antihypertensives was retrieved by chart review. In each group, 39 patients received echocardiographic examinations.

RESULTS

PD patients' fluid status was similar to that of predialysis HD patients. PD patients had lower systolic BP. E/E' and left ventricular mass index (LVMI) showed no significant intergroup difference. In multiple linear regression analyses, overhydration (OH)/extracellular water ratio >0.15 was associated with higher systolic BP, E/E' and LVMI.

CONCLUSIONS

While PD was associated with higher OH but non-inferior BP control and heart function, OH was indeed related to poor BP control, diastolic dysfunction and left ventricular hypertrophy.

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.

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.

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.

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.