Inhibition of sodium-glucose cotransporter-2 and liver-related complications in individuals with diabetes: a Mendelian randomization and population-based cohort study

BACKGROUND AND AIMS

No medication has been found to reduce liver-related events. We evaluated the effect of sodium-glucose cotransporter-2 inhibitor (SGLT2i) on liver-related outcomes.

APPROACH AND RESULTS

Single nucleotide polymorphisms associated with SGLT2 inhibition were identified, and a genetic risk score (GRS) was computed using the UK Biobank data (n=337,138). Two-sample Mendelian randomization (MR) was conducted using the FinnGen (n=218,792) database and the UK Biobank data. In parallel, a nationwide population-based study using the Korean National Health Insurance Service (NHIS) database was conducted. The development of liver-related complications (ie, hepatic decompensation, HCC, liver transplantation, and death) was compared between individuals with type 2 diabetes mellitus and steatotic liver diseases treated with SGLT2i (n=13,208) and propensity score-matched individuals treated with dipeptidyl peptidase-4 inhibitor (n=70,342). After computing GRS with 6 single nucleotide polymorphisms (rs4488457, rs80577326, rs11865835, rs9930811, rs34497199, and rs35445454), GRS-based MR showed that SGLT2 inhibition (per 1 SD increase of GRS, 0.1% lowering of HbA1c) was negatively associated with cirrhosis development (adjusted odds ratio=0.83, 95% CI=0.70-0.98, p =0.03) and this was consistent in the 2-sample MR (OR=0.73, 95% CI=0.60-0.90, p =0.003). In the Korean NHIS database, the risk of liver-related complications was significantly lower in the SGLT2i group than in the dipeptidyl peptidase-4 inhibitor group (adjusted hazard ratio=0.88, 95% CI=0.79-0.97, p =0.01), and this difference remained significant (adjusted hazard ratio=0.72-0.89, all p <0.05) across various sensitivity analyses.

CONCLUSIONS

Both MRs using 2 European cohorts and a Korean nationwide population-based cohort study suggest that SGLT2 inhibition is associated with a lower risk of liver-related events.

Extrahepatic malignancies in metabolic dysfunction-associated fatty liver disease: A nationwide cohort study

BACKGROUND AND AIMS

Metabolic dysfunction-associated fatty liver disease (MAFLD) encompasses heterogeneous fatty liver diseases associated with metabolic disorders. We aimed to evaluate the association between MAFLD and extrahepatic malignancies based on MAFLD subtypes.

METHODS

This nationwide cohort study included 9 298 497 patients who participated in a health-screening programme of the National Health Insurance Service of Korea in 2009. Patients were further classified into four subgroups: non-MAFLD, diabetes mellitus (DM)-MAFLD, overweight/obese-MAFLD and lean-MAFLD. The primary outcome was the development of any primary extrahepatic malignancy, while death, decompensated liver cirrhosis and liver transplantation were considered competing events. The secondary outcomes included all-cause and extrahepatic malignancy-related mortality.

RESULTS

In total, 2 500 080 patients were diagnosed with MAFLD. During a median follow-up of 10.3 years, 447 880 patients (6.0%) with extrahepatic malignancies were identified. The DM-MAFLD (adjusted subdistribution hazard ratio [aSHR] = 1.13; 95% confidence interval [CI] = 1.11-1.14; p < .001) and the lean-MAFLD (aSHR = 1.12; 95% CI = 1.10-1.14; p < .001) groups were associated with higher risks of extrahepatic malignancy than the non-MAFLD group. However, the overweight/obese-MAFLD group exhibited a similar risk of extrahepatic malignancy compared to the non-MAFLD group (aSHR = 1.00; 95% CI = .99-1.00; p = .42). These findings were reproduced in several sensitivity analyses. The DM-MAFLD was an independent risk factor for all-cause mortality (adjusted hazard ratio [aHR] = 1.41; 95% CI = 1.40-1.43; p < .001) and extrahepatic malignancy-related mortality (aHR = 1.20; 95% CI = 1.17-1.23; p < .001).

CONCLUSION

The diabetic or lean subtype of MAFLD was associated with a higher risk of extrahepatic malignancy than non-MAFLD. As MAFLD comprises a heterogeneous population, appropriate risk stratification and management based on the MAFLD subtypes are required.

Editorial: Paradox of liver fat content in the spectrum of non-alcoholic fatty liver disease

This article is linked to Loomba et al paper. To view this article, visit https://doi.org/10.1111/apt.17783

Association between statin use and the prognosis of hepatocellular carcinoma after resection: a nationwide cohort study

Background

The majority of patients with hepatocellular carcinoma (HCC) following hepatic resection experience tumor recurrence. Statin use is associated with a reduced risk of HCC development; however, the association between statin use and the prognosis of HCC after resection remains unclear. We aimed to investigate the effect of statin use on the prognosis after hepatic resection among patients with HCC.

Methods

A nationwide cohort study was performed with data from the National Health Insurance Service Database in Korea. Among 65,101 HCC patients who underwent hepatic resection between January 2002 and December 2017, we included 21,470 patients. For validation, a hospital-based cohort of 3366 patients with very early or early-stage HCC who received curative-intent hepatic resection between January 2010 and December 2018 was analyzed. Recurrence-free survival (RFS) and overall survival (OS) was compared between statin users and non-users.

Findings

Among the nationwide cohort of 21,470 patients, 2399 (11.2%) used statins and 19,071 (88.8%) did not. Among the hospital cohort of 3366 patients, 363 (10.8%) used statins and 3003 (89.2%) did not. In the propensity score-matched nationwide cohort, statin users had better RFS (hazard ratio [HR], 0.60; 95% confidence interval [CI], 0.56-0.64; P < 0.001) and OS (HR, 0.49; 95% CI, 0.45-0.53; P < 0.001), with a duration-response relationship. In the propensity score-matched validation hospital cohort, statin treatment was significantly associated with better RFS (HR, 0.73; 95% CI, 0.59-0.90; P = 0.003) and OS (HR, 0.48; 95% CI, 0.32-0.72; P < 0.001). The beneficial effects of statins were more prominent in non-cirrhotics, tumors sized ≥3 cm, tumors with microscopic vascular invasion, or early HCC recurrence (<2 years after resection).

Interpretation

Statin use was associated with a better prognosis in a population-based cohort of patients with HCC after hepatic resection, which was further validated in a large hospital-based cohort.

Funding

Asan Institute for Life Sciences and Corporate Relations; Korean Association for the Study of the Liver.

COVID-19 Vaccination Alters NK Cell Dynamics and Transiently Reduces HBsAg Titers Among Patients With Chronic Hepatitis B

Coronavirus disease 2019 (COVID-19) vaccination may non-specifically alter the host immune system. This study aimed to evaluate the effect of COVID-19 vaccination on hepatitis B surface Ag (HBsAg) titer and host immunity in chronic hepatitis B (CHB) patients. Consecutive 2,797 CHB patients who had serial HBsAg measurements during antiviral treatment were included in this study. Changes in the HBsAg levels after COVID-19 vaccination were analyzed. The dynamics of NK cells following COVID-19 vaccination were also examined using serial blood samples collected prospectively from 25 healthy volunteers. Vaccinated CHB patients (n=2,329) had significantly lower HBsAg levels 1-30 days post-vaccination compared to baseline (median, -21.4 IU/ml from baseline), but the levels reverted to baseline by 91-180 days (median, -3.8 IU/ml). The velocity of the HBsAg decline was transiently accelerated within 30 days after vaccination (median velocity: -0.06, -0.39, and -0.04 log10 IU/ml/year in pre-vaccination period, days 1-30, and days 31-90, respectively). In contrast, unvaccinated patients (n=468) had no change in HBsAg levels. Flow cytometric analysis showed that the frequency of NK cells expressing NKG2A, an NK inhibitory receptor, significantly decreased within 7 days after the first dose of COVID-19 vaccine (median, -13.1% from baseline; p<0.001). The decrease in the frequency of NKG2A+ NK cells was observed in the CD56dimCD16+ NK cell population regardless of type of COVID-19 vaccine. COVID-19 vaccination leads to a rapid, transient decline in HBsAg titer and a decrease in the frequency of NKG2A+ NK cells.

Treated chronic hepatitis B is a good prognostic factor of diffuse large B-cell lymphoma

BACKGROUND/AIMS

Chronic hepatitis B (CHB) is a risk factor for non-Hodgkin lymphoma (NHL). Our recent study suggested that antiviral treatment may reduce the incidence of NHL in CHB patients. This study compared the prognoses of hepatitis B virus (HBV)-associated diffuse large B-cell lymphoma (DLBCL) patients receiving antiviral treatment and HBV-unassociated DLBCL patients.

METHODS

This study comprised 928 DLBCL patients who were treated with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) at two referral centers in Korea. All patients with CHB received antiviral treatment. Time-to-progression (TTP) and overall survival (OS) were the primary and secondary endpoints, respectively.

RESULTS

Among the 928 patients in this study, 82 were hepatitis B surface antigen (HBsAg)-positive (the CHB group) and 846 were HBsAg-negative (the non-CHB group). The median follow-up time was 50.5 months (interquartile range [IQR]=25.6-69.7 months). Multivariable analyses showed longer TTP in the CHB group than the non-CHB group both before inverse probability of treatment weighting (IPTW; adjusted hazard ratio [aHR]=0.49, 95% confidence interval [CI]=0.29-0.82, p=0.007) and after IPTW (aHR=0.42, 95% CI=0.26-0.70, p<0.001). The CHB group also had a longer OS than the non-CHB group both before IPTW (HR=0.55, 95% CI=0.33-0.92, log-rank p=0.02) and after IPTW (HR=0.53, 95% CI=0.32-0.99, log-rank p=0.02). Although liver-related deaths did not occur in the non-CHB group, two deaths occurred in the CHB group due to hepatocellular carcinoma and acute liver failure, respectively.

CONCLUSION

Our findings indicate that HBV-associated DLBCL patients receiving antiviral treatment have significantly longer TTP and OS after R-CHOP treatment than HBV-unassociated DLBCL patients.

Transarterial chemoembolization as an alternative to radioembolization is associated with earlier tumor recurrence than in radioembolization-eligible patients

Introduction

Although transarterial radioembolization (TARE) using yttrium-90 (⁹⁰Y) is a treatment option for large hepatocellular carcinoma (HCC), a fraction of patients are ineligible for TARE due to high lung shunt fraction (LSF).

Methods

We evaluated if treatment with transarterial chemoembolization (TACE), owing to TARE ineligibility was associated with early HCC progression. Consecutive patients with HCC who were initially TARE candidates were included. Patients with vascular invasion or metastasis were excluded. Primary endpoints were time-to-progression (TTP) and overall survival (OS). The secondary endpoint was objective response rate.

Results

In total, 175 patients were included: 144 underwent TARE (TARE-eligible group) and 31 underwent TACE due to high LSF (TARE-ineligible group). This latter group had larger tumors (13.8 cm vs. 7.8 cm, P<0.001) and higher MoRAL scores (1,385.8 vs. 413.3, P=0.002) than the TARE-eligible group. After balancing baseline characteristics with an inverse probability of treatment weighting (IPTW), the TARE-ineligible group showed shorter TTP [adjusted hazard ratio (aHR)=2.16, 95% confidence interval (CI)=1.14-4.07, P=0.02] and OS (aHR=1.80, 95% CI=0.85-3.80, P=0.12), although the latter was not statistically significant. The TARE-ineligible group had a significantly lower objective response rate than the TARE-eligible group (9.7% vs. 56.9%, P<0.001).

Conclusion

TARE-ineligible patients had larger tumors and higher MoRAL scores than TARE-eligible patients. Treatment with TACE, owing to high LSF, was associated with a shorter TTP even after balancing tumor size and MoRAL scores.

Association of Chronic Hepatitis B Infection and Antiviral Treatment With the Development of the Extrahepatic Malignancies: A Nationwide Cohort Study

PURPOSE

Epidemiologic studies suggest that chronic hepatitis B (CHB) is a risk factor for various primary extrahepatic malignancies. Our aim was to evaluate the associations of CHB and nucleos(t)ide analog (NA) treatment with the risk of the development of extrahepatic malignancies.

PATIENTS AND METHODS

We conducted an 18-month landmark analysis using nationwide claims data from the National Health Insurance Service of South Korea. Patients newly diagnosed with CHB in 2012-2014 (n = 90,944) and matched-controls (n = 685,436) were included. Patients with CHB were further classified as the NA-treated (CHB+/NA+, n = 6,539) or the NA-untreated (CHB+/NA-, n = 84,405) group. Inverse probability of treatment weighting analysis was applied to balance the treatment groups. Time-varying Cox analysis was performed to evaluate time-varying effect of NA treatment. The primary outcome was the development of any primary extrahepatic malignancy. Development of intrahepatic malignancy and death were considered as competing events.

RESULTS

During the study period (median = 47.4 months), 30,413 patients (3.9%) developed any extrahepatic malignancy. The CHB+/NA- group had a higher overall risk of extrahepatic malignancy than the CHB+/NA+ group (adjusted subdistribution hazard ratio [aSHR] = 1.28; 95% CI, 1.12 to 1.45; P < .001) or controls (aSHR = 1.22; 95% CI, 1.18 to 1.26; P < .001). There was no difference in the risk of extrahepatic malignancy between the CHB+/NA+ group and the controls (CHB+/NA+ v control: aSHR = 0.96; 95% CI, 0.84 to 1.08; P = .48). In time-varying Cox analysis, the CHB+/NA- patients were associated with a higher risk of extrahepatic malignancy than the CHB+/NA+ patients (aSHR = 1.37; 95% CI, 1.23 to 1.52; P < .001).

CONCLUSION

Patients with CHB have an elevated risk of developing primary extrahepatic malignancy. Long-term NA treatment was associated with a lower risk of extrahepatic malignancy development among patients with CHB.

High Estimated 24-Hour Urinary Sodium Excretion Is Related to Symptomatic Knee Osteoarthritis: A Nationwide Cross-Sectional Population-Based Study

OBJECTIVES

High salt intake results in various harmful effects on human health including hypertension, cardiovascular disease, and reduced bone density. Despite this, there are very few studies in the literature that have investigated the association between sodium intake and osteoarthritis (OA). Therefore, we aimed to explore these associations in a Korean population.

METHODS

This study used cross-sectional data from adult subjects aged 50-75 years from two consecutive periods of the Korean National Health and Nutrition Examination Survey V-VII (2010-2011 and 2014-2016). The estimated 24-hour urinary sodium excretion (24HUNa) was used as a surrogate marker of salt intake. In the 2010-2011 dataset, knee OA (KOA) was defined as the presence of the radiographic features of OA and knee pain. The association between KOA and salt intake was analysed using univariable and multivariable logistic regression methods. For the sensitivity analysis, the same procedures were conducted on subjects with self-reported OA (SR-OA) with knee pain in the 2010-2011 dataset and any site SR-OA in the 2014-2016 dataset.

RESULTS

Subjects with KOA had significantly lower energy intake, but higher 24HUNa than those without KOA. The restricted cubic spline plots demonstrated a J-shaped distribution between 24HUNa and prevalent KOA. When 24HUNa was stratified into five groups (<2, 2-3, 3-4, 4-5 and ≥5 g/day), subjects with high sodium intake (≥5 g/day) had a higher risk of KOA (odds ratio [OR] = 1.64, 95% confidence interval [CI] 1.03-2.62) compared to the reference group (3-4 g/day) after adjusting for covariates. The sensitivity analysis based on SR-OA with knee pain showed that high sodium intake was also significantly associated with increased prevalence of OA (OR = 1.84, 95% CI 1.10-3.10) compared with the reference group. Regarding SR-OA at any site in the 2014-2016 dataset, estimated 24HUNa showed a significantly positive association with the presence of SR-OA after adjusting for potential confounders.

CONCLUSIONS

This nationwide Korean representative study showed a significant association between symptomatic KOA and high sodium intake (≥5 g/day). Avoidance of a diet high in salt might be beneficial as a non-pharmacologic therapy for OA.

Effectiveness of Transarterial Chemoembolization-First Treatment for Advanced Hepatocellular Carcinoma: A Propensity Score Matching Analysis

Background

Still in real-world practice, advanced hepatocellular carcinoma (HCC) patients are treated with transarterial chemoembolization (TACE). This study compared the therapeutic effectiveness of initial TACE treatment and initial sorafenib treatment in advanced HCC patients.

Patient and Methods

Advanced HCC patients initially treated with sorafenib or TACE were included in this study. Treatment crossover due to an unfavorable response to initial treatment was allowed. Propensity score (PS) matching was applied for balancing baseline characteristics. The primary outcome was overall survival (OS) and the secondary outcomes included tumor response.

Results

A total of 554 patients were included in this study: 85 were initially treated with sorafenib (the sorafenib-first group) and 469 with TACE (the TACE-first group). In the entire cohort, the TACE-first group was associated with lower risk of death [adjusted hazard ratio (HR)=0.75, P=0.04]. In the PS-matched cohort (85 patients per group), the TACE-first group showed longer OS than the sorafenib-first group in both univariable (HR=0.68, P=0.02) and multivariable analyses (adjusted HR=0.58, P=0.002). Specifically, within both the entire and the PS-matched cohorts, the TACE-first group showed longer OS in subgroups with major portal vein tumor thrombosis (HR=0.72, P=0.048; HR=0.52, P=0.003) or infiltrative HCC (HR=0.42, P<0.001; HR=0.30, P=0.004, respectively). The objective response rate was higher in the TACE-first group (29.3% vs 14.7%, P=0.03) within the PS-matched cohort.

Conclusion

For advanced HCC, initial TACE leads to longer OS with a more favorable tumor response than initial sorafenib treatment. Intrahepatic tumor control with initial locoregional therapy may be a potent strategy for advanced HCC.

Empirical Treatment With Carbapenem vs Third-generation Cephalosporin for Treatment of Spontaneous Bacterial Peritonitis

BACKGROUND & AIMS

Third-generation cephalosporins (TGCs) are recommended as first-line antibiotics for treatment of spontaneous bacterial peritonitis (SBP). However, antibiotics against multidrug-resistant organisms (such as carbapenems) might be necessary. We aimed to evaluate whether carbapenems are superior to TGC for treatment of SBP.

METHODS

We performed a retrospective study of 865 consecutive patients with a first presentation of SBP (275 culture positive; 103 with TGC-resistant bacterial infections) treated at 7 referral centers in Korea, from September 2013 through January 2018. The primary outcome was in-hospital mortality. We made all comparisons using data from patients whose baseline characteristics were balanced by inverse probability of treatment weighting.

RESULTS

Of patients who initially received empirical treatment with antibiotics, 95 (11.0%) received carbapenems and 655 (75.7%) received TGCs. Among the entire study cohort, there was no significant difference in in-hospital mortality between the carbapenem (25.8%) and TGC (25.3%) groups (adjusted odds ratio [aOR], 0.97; 95% CI, 0.85-1.11; P = .66). In the subgroup of patients with high chronic liver failure-sequential organ failure assessment (CLIF-SOFA) scores (score of 7 or greater, n = 314), carbapenem treatment was associated with lower in-hospital mortality (23.1%) than in the TGC group (38.8%) (aOR, 0.84; 95% CI, 0.75-0.94; P=.002). In contrast, among patients with lower CLIF-SOFA scores (n = 436), in-hospital mortality did not differ significantly between the carbapenem group (24.7%) and the TGC group (16.0%) (aOR, 1.06; 95% CI, 0.85-1.32; P = .58).

CONCLUSIONS

For patients with a first presentation of SBP, empirical treatment with carbapenem does not reduce in-hospital mortality compared to treatment with TGCs. However, among critically ill patients (CLIF-SOFA scores ≥7), empirical carbapenem treatment was significantly associated with lower in-hospital mortality than TGCs.

Prognostic impact of concurrent nonalcoholic fatty liver disease in patients with chronic hepatitis B-related hepatocellular carcinoma

BACKGROUND AND AIM

As the prevalence of nonalcoholic fatty liver disease (NAFLD) is increasing globally, patients with both NAFLD and chronic hepatitis B (CHB)-related hepatocellular carcinoma (HCC) is also frequently found. This study aimed to investigate the clinical impact of concurrent NAFLD on the prognosis of patients with CHB-related HCC.

METHODS

Patients with CHB-related HCC who underwent surgical resection were consecutively selected from August 2009 to December 2013. The association between histologically proven concurrent NAFLD and clinical outcomes were analyzed. Propensity score (PS) matching was adapted to adjust for baseline characteristics. We also investigated the presence of nonalcoholic steatohepatitis (NASH) among patients with NAFLD and its association with clinical outcomes.

RESULTS

Among 338 CHB-related HCC patients selected, 196 patients (58.0%) were diagnosed with concurrent NAFLD. The median follow-up duration was 74.9 months. The patients with NAFLD tended to have better recurrence-free survival (RFS; log-rank, P = 0.16) and had significantly better overall survival (OS; log-rank, P = 0.004) than those without NAFLD. However, the survival benefit of the concurrent NAFLD was not significant in a multivariable Cox analysis (adjusted hazard ratio, 0.94; 95% confidence interval, 0.51-1.73, P = 0.84) or an analysis after PS matching (log-rank, P = 0.57). Regarding the presence or absence of NASH, no differences in the RFS (log-rank, P = 0.61) and OS (log-rank, P = 0.26) were found.

CONCLUSIONS

Concurrent NAFLD was not associated with both RFS and OS in patients with CHB-related HCC after adjusting for baseline characteristics. Moreover, NAFLD patients with NASH did not have significantly different clinical outcomes compared with NAFLD patients without NASH.

Additional fibrate treatment in UDCA-refractory PBC patients

BACKGROUND & AIMS

There is no proven treatment for ursodeoxycholic acid (UDCA)-refractory primary biliary cholangitis (PBC) other than obeticholic acid. Although fibrates have been reported to improve biochemical parameters, the long-term effects remain unclear. This study evaluated the effect of fibrate on clinical outcomes of UDCA-refractory PBC.

METHODS

Patients whose alkaline phosphatase (ALP) was not normalized with at least 13 mg/kg of UDCA treatment for >1 year were included from two tertiary referral centres. The primary outcome was ALP normalization. Secondary outcomes included the development of cirrhosis and hepatic deterioration. Immortal time bias was adjusted using the Mantel-Byar method.

RESULTS

A total of 100 UDCA-refractory PBC patients were included: 71 patients received UDCA alone (the UDCA group) and 29 patients received UDCA plus additional fibrate treatment of 160 mg/d fenofibrate or 400 mg/d bezafibrate (the fibrate/UDCA group). During the follow-up period, the probability of ALP normalization was significantly higher in the fibrate/UDCA group (hazard ratio [HR] = 5.00, 95% confidence interval = 2.87-8.27, P < 0.001). Among 58 non-cirrhotic patients (43 in the UDCA group and 15 in the fibrate/UDCA group), 19 patients (44.1%) in the UDCA group and none in the fibrate/UDCA group developed cirrhosis (HR = 0.12, P = 0.04). Hepatic deterioration (Child-Pugh score increase or signs of decompensated cirrhosis) occurred in 17 patients (23.9%) of the UDCA group and none in the fibrate/UDCA group in which the difference was significant (HR = 0.12, P = 0.04).

CONCLUSIONS

In patients with UDCA-refractory PBC, additional fibrate treatment is associated with a higher probability of ALP normalization and a lower risk of cirrhosis development and hepatic deterioration.

Incremental Peritoneal Dialysis May be Beneficial for Preserving Residual Renal Function Compared to Full-dose Peritoneal Dialysis

Maintaining residual renal function (RRF) is a crucial issue in peritoneal dialysis (PD). Incremental dialysis is the practice of initiating PD exchanges less than four times a day in consideration of RRF, and increasing dialysis dose in a step-wise manner as the RRF decreases. We aimed to compare the outcomes of incremental PD and full-dose PD in terms of RRF preservation and other outcomes. This was a single-center, observational study. Data were extracted retrospectively from a cohort of incident PD patients over 16 years old who started PD between 2007 and 2015 in the PD Unit of Seoul National University Hospital. We used inverse probability weighting (IPW) adjustment based on propensity scores to balance covariates between the incremental and full-dose PD groups. Multivariate, time-dependent Cox analyses were performed. Among 347 incident PD patients, 176 underwent incremental PD and 171 underwent conventional full-dose PD. After IPW adjustment, the incremental PD group exhibited a lower risk of developing anuria (hazard ratio [HR] 0.61, 95% confidence interval [CI] 0.43–0.88). Patient survival, technique survival, and peritonitis-free survival were all similar between these groups (P > 0.05 by log-rank test). Incremental PD was beneficial for preserving RRF and showed similar patient survival when compared to conventional full-dose PD.

A systemic lupus erythematosus patient with thunderclap headache: reversible cerebral vasoconstriction syndrome

Headaches are common in patients with systemic lupus erythematosus (SLE). It is important to identify the exact cause of headaches in SLE to avoid unnecessary steroid or immunosuppressive therapy like in neuropsychiatric SLE. A 35-year-old woman with SLE suddenly developed severe headache. Magnetic resonance angiography showed multifocal segmental narrowing of cerebral arteries, suggestive of central nervous system vasculitis. However, lack of abnormal enhancement in vessel wall imaging indicated reversible cerebral vasoconstriction syndrome (RCVS) rather than central nervous system vasculitis. The patient was treated with oral nimodipine and she recovered over a period of two months. Following magnetic resonance angiography on day 90 was normal. Herein we report a case of reversible cerebral vasoconstriction syndrome in an SLE patient with literature review.

The measurement of bone mineral density of bilateral proximal humeri using DXA in patients with unilateral rotator cuff tear

We propose that the measurement of the bone mineral density (BMD) of the proximal humerus be standardized using the dual energy X-ray absorptiometry (DXA) in patients supposed to undergo rotator cuff repair surgery as well as those with the fracture of the proximal humerus as the BMD of the proximal humerus is decreased in these patients.

INTRODUCTION

We propose that the measurement of the BMD of the proximal humerus be standardized using the DXA in patients who are supposed to undergo rotator cuff repair surgery as well as those with the fracture of the proximal humerus.

METHODS

We conducted the prospective study in 213 patients with unilateral rotator cuff tear but without contralateral shoulder pain or disease. In these patients, we preoperatively measured the BMD of the bilateral proximal humeri with a repeat measurement in 20 patients. We predefined three regions of interest (ROIs) in the proximal humerus with the consideration of the rotator cuff repair surgery as well as proximal humeral fractures.

RESULTS

The measurement of the BMD of the proximal humerus using the DXA showed excellent reliability (intraclass correlation coefficient > .90). BMD values of all three ROIs in the affected shoulder were significantly lower than those in asymptomatic shoulder (all p < 0.05). In female patients, the BMD values of ROIs in bilateral shoulder were significantly lower than those in male patients (all p < 0.001). In multiple regressions, however, there were no significant correlations between other clinical characteristics, except for the gender, and the BMD of GT in the affected shoulder.

CONCLUSIONS

It is imperative that the bone quality of the proximal humerus be accurately evaluated prior to surgery in patients who are supposed to undergo rotator cuff repair using suture anchors as well as in those with proximal humeral fractures. This is because the BMD of the proximal humerus is decreased in these patients.

Modelling a turbidity current in Soyang reservoir (Korea) and its control using a selective withdrawal facility

Persistent turbidity in reservoirs and their downstream after flood events is one of most important environmental issues in Korea. Recently, modification of withdrawal facility and installation of a new selective withdrawal structure (SWS) have been implemented for the mitigation of downstream impact and sediment loading into water treatment facilities. This study was to explore the characteristics of flood density flow induced into Soyang Reservoir and the transport processes of suspended sediments (SS) through application of coupled two-dimensional hydrodynamic and particle dynamic models (TM-1, TM-2 and TM-3). The TM-3 including a turbidity attenuation rate as a lumped parameter showed best performance in reproducing the magnitude and distribution of SS in the reservoir. The validated model was applied to evaluate the effectiveness of SWS, which was designed for the reservoir, with 6 different historical flood events. The magnitude of vertical mixing of the turbidity plume and its persistence within the reservoir were closely correlated to the ratio of the volume of turbidity flow to the total reservoir storage (the theta value). The operation of SWS showed a positive effect as long as theta is between 0.3 and 0.6 but negative when theta = 0.83 for the study reservoir, thus it should be optimized based on the theta value for a better management of the reservoir.

Characterization and modeling of turbidity density plume induced into stratified reservoir by flood runoffs

In monsoon climate area, turbidity flows typically induced by flood runoffs cause numerous environmental impacts such as impairment of fish habitat and river attraction, and degradation of water supply efficiency. This study was aimed to characterize the physical dynamics of turbidity plume induced into a stratified reservoir using field monitoring and numerical simulations, and to assess the effect of different withdrawal scenarios on the control of downstream water quality. Three different turbidity models (RUN1, RUN2, RUN3) were developed based on a two-dimensional laterally averaged hydrodynamic and transport model, and validated against field data. RUN1 assumed constant settling velocity of suspended sediment, while RUN2 estimated the settling velocity as a function of particle size, density, and water temperature to consider vertical stratification. RUN3 included a lumped first-order turbidity attenuation rate taking into account the effects of particles aggregation and degradable organic particles. RUN3 showed best performance in replicating the observed variations of in-reservoir and release turbidity. Numerical experiments implemented to assess the effectiveness of different withdrawal depths showed that the alterations of withdrawal depth can modify the pathway and flow regimes of the turbidity plume, but its effect on the control of release water quality could be trivial.

Diffusion tensor MR imaging and fiber tractography: technical considerations

This second article of the 2-part review builds on the theoretic background provided by the first article to cover the major technical factors that affect image quality in diffusion imaging, including the acquisition sequence, magnet field strength, gradient amplitude, and slew rate as well as multichannel radio-frequency coils and parallel imaging. The sources of many common diffusion image artifacts are also explored in detail. The emphasis is on optimizing these technical factors for state-of-the-art diffusion-weighted imaging and diffusion tensor imaging (DTI) based on the best available evidence in the literature. An overview of current methods for quantitative analysis of DTI data and fiber tractography in clinical research is also provided.

Diffusion tensor MR imaging and fiber tractography: theoretic underpinnings

In this article, the underlying theory of clinical diffusion MR imaging, including diffusion tensor imaging (DTI) and fiber tractography, is reviewed. First, a brief explanation of the basic physics of diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) mapping is provided. This is followed by an overview of the additional information that can be derived from the diffusion tensor, including diffusion anisotropy, color-encoded fiber orientation maps, and 3D fiber tractography. This article provides the requisite background for the second article in this 2-part review to appear next month, which covers the major technical factors that affect image quality in diffusion MR imaging, including the acquisition sequence, magnet field strength, gradient amplitude and slew rate, and multichannel radio-frequency coils and parallel imaging. The emphasis is on optimizing these factors for state-of-the-art DWI and DTI based on the best available evidence in the literature.

Accuracy of diffusion tensor magnetic resonance imaging tractography assessed using intraoperative subcortical stimulation mapping and magnetic source imaging

OBJECT

Resecting brain tumors involves the risk of damaging the descending motor pathway. Diffusion tensor (DT)-imaged fiber tracking is a noninvasive magnetic resonance (MR) technique that can delineate the subcortical course of the motor pathway. The goal of this study was to use intraoperative subcortical stimulation mapping of the motor tract and magnetic source imaging to validate the utility of DT-imaged fiber tracking as a tool for presurgical planning.

METHODS

Diffusion tensor-imaged fiber tracks of the motor tract were generated preoperatively in nine patients with gliomas. A mask of the resultant fiber tracks was overlaid on high-resolution T1- and T2-weighted anatomical MR images and used for stereotactic surgical navigation. Magnetic source imaging was performed in seven of the patients to identify functional somatosensory cortices. During resection, subcortical stimulation mapping of the motor pathway was performed within the white matter using a bipolar electrode.

RESULTS

A total of 16 subcortical motor stimulations were stereotactically identified in nine patients. The mean distance between the stimulation sites and the DT-imaged fiber tracks was 8.7 +/- 3.1 mm (+/- standard deviation). The measured distance between subcortical stimulation sites and DT-imaged fiber tracks combines tracking technique errors and all errors encountered with stereotactic navigation.

CONCLUSIONS

Fiber tracks delineated using DT imaging can be used to identify the motor tract in deep white matter and define a safety margin around the tract.

Diffusion tensor MR imaging tractography of the pyramidal tracts correlates with clinical motor function in children with congenital hemiparesis

BACKGROUND AND PURPOSE

Children with congenital hemiparesis have greater asymmetry in diffusion parameters of the pyramidal tracts compared with control subjects. We hypothesized that the asymmetry correlates with the severity of hemiparesis and that diffusion metrics would be abnormal in the affected tracts and normal in the unaffected tracts.

MATERIALS AND METHODS

Fifteen patients with congenital hemiparesis and 17 age-matched control subjects were studied with diffusion tensor MR imaging tractography. Hemipareses were scored as mild, moderate, or severe. We measured tract-specific diffusion parameters (fractional anisotropy, mean, and directional diffusion coefficients) of the pyramidal tracts. We compared tract-specific parameters and asymmetry between the right and left tracts of the differing severity groups and control subjects.

RESULTS

We observed many different causes of congenital hemiparesis including venous infarction, arterial infarction, and polymicrogyria. Clinical severity of hemiparesis correlated with asymmetry in fractional anisotropy (P < .0001), transverse diffusivity (P < .0001), and mean diffusivity (P < .03). With increasing severity of hemiparesis, fractional anisotropy decreased (P < .0001) and transverse diffusivity (P < .0001) and mean diffusivity (P < .02) increased in the affected pyramidal tract compared with controls. Diffusion metrics in the unaffected tract were similar to those in the control subjects.

CONCLUSION

Asymmetry in fractional anisotropy, transverse diffusivity, and mean diffusivity, as well as the degree of abnormality in the actual values of the affected pyramidal tracts themselves, correlates with the severity of motor dysfunction in infants and children with congenital hemiparesis from different causes. This suggests that abnormalities detected by diffusion tensor MR imaging tractography in the affected pyramidal tract are related to the functional ability of the affected pyramidal tract, regardless of the etiology of motor dysfunction.

Promoter methylation of helicase-like transcription factor is associated with the early stages of gastric cancer with family history

BACKGROUND

To investigate the clinicopathological significance of promoter methylation of the helicase-like transcription factor (HLTF) in primary gastric cancer.

PATIENTS AND METHODS

Two-hundred fifty six patients participated in this study. Methylation status of HLTF gene was evaluated in fresh-frozen tissues by the methylation-specific polymerase chain reaction. All statistical analyses were two-sided, with a 5% type I error rate.

RESULTS

Aberrant methylation of HLTF was found in 98 (38%) of 256 gastric cancer patients. HLTF methylation was significantly associated with a family history in the early stages of gastric cancer, regardless of histologic types. In intestinal-type cases, HLTF methylation occurred in 15 (56%) of 27 patients with family histories, and in 26 (31%) of 85 patients without family histories (P = 0.02). In diffuse-type cases, patients with family histories were also found to exhibit a higher prevalence of HLTF methylation than those without family histories (61% vs. 34%; P = 0.009). HLTF methylation in both of the histologic types occurred in about 70-90% of the early stage cases in which the patient had a family history and in 15-30% of cases in which the patient did not have a family history. In our multivariate logistic regression analysis, the stage 1-2 cases with family histories were determined to carry a higher risk of HLTF methylation than did the stage 3-4 cases without family histories in both the intestinal-type (OR = 6.01, 95% CI = 1.20-30.01, P = 0.02) and the diffuse-type cancers (OR = 8.25, 95% CI = 1.67-40.86, P = 0.009).

CONCLUSIONS

These results suggest that HLTF methylation may play a crucial role in the early stages of gastric carcinogenesis in patients with family histories and may be a valuable susceptible marker for the risk of gastric cancer in individuals with family histories.

Calibration of CE-QUAL-W2 for a monomictic reservoir in a monsoon climate area

The impact of inflow mixing on reservoir stratification is significant for reservoirs situated in a monsoon climate area. It cause difficulty in the calibration of a two-dimensional hydrodynamic and water quality model, CE-QUAL-W2 that was recently adopted for a real-time turbidity monitoring and modelling system (RTMMS) for a reservoir in Korea. This paper presents a systematic calibration and verification processe of the model for the reservoir. A sensitivity analysis showed that wind sheltering, Chezy, and sediment heat exchange coefficients are most sensitive to stratification structure. Inflow temperature was very sensitive during a year of normal precipitation, but it is not significant during a year of drought. Residual analysis revealed that the model has shortcomings in the simulation of water temperature near the metalimnetic zone without calibration. After calibration, however, the absolute mean errors between observed and simulated values were placed within 0.116-1.190 degrees C. Its performance was maintained under heavy flood events during the verification stage, which implies that the model is ready to use for the simulation of turbidity plume in the RTMMS under various hydrologic conditions. The suggested model calibration strategy and relevant results may be adopted for other reservoirs located in a monsoon climate area.

Recurrent hepatocellular carcinoma after liver transplantation mimicking post-transplantation lymphoproliferative disorder

Approximately 5% of patients with end-stage cirrhosis undergoing orthotopic liver transplantation have occult hepatocellular carcinoma. Careful follow up is required to detect recurrent tumour, and knowledge of the patterns of recurrence may avoid diagnostic confusion with other malignancies, such as post-transplantation lymphoproliferative disorder. This case report illustrates an unusual presentation of recurrent hepatocellular carcinoma in a 56-year-old man presenting with a para-aortic soft tissue mass, thought clinically and radiologically to represent lymphoma or post-transplantation lymphoproliferative disorder. This case demonstrates that recurrent hepatocellular carcinoma can present late after transplantation as retroperitoneal lymphadenopathy, and should alert physicians and radiologists to be aware of the radiological appearances of recurrence and of the need for early biopsy to avoid diagnostic confusion with other malignancies.

Development of water quality models for supporting NH3-N control in a dam regulated river

A seasonal occurrence of high ammonia nitrogen (NH3-N) concentrations has hampered chemical treatment processes of a water plant in Geum river of Korea. Monthly flow allocation from upstream dam is important for downstream NH3-N control. In this study, water quality models based on multiple regression (MR) and artificial neural network (ANN) methods were developed to support dam operations through providing forecasted NH3-N concentrations. The models were calibrated with 7 years of monthly data, and verified with another 3 years of independent data. In the models, the NH3-N concentration for next time step is dependent on dam outflow, river water quality such as alkalinity, temperature, and NH3-N of previous time step. During the calibration phase, the ANN models compared to MR models showed a better agreement with observed data as indicated with small RMSE and high R2 values. However, in the verification phase, the performance of ANN models was decreased and showed a little difference to MR models. From the model comparisons, it is recommended for both ANN and MR models to include the autocorrelation of NH3-N concentrations up to 3-lag months to avoid overestimation during low flow season.

Hepatic abscesses after liver transplantation secondary to traumatic intrahepatic bile duct injuries in a cadaveric allograft donor

We report the case of an ultimately successful liver transplant recipient whose post-transplant course was complicated by the early development of multiple abscesses in the graft. Post-transplant cholangiography identified multiple shear injuries to the second and third order intrahepatic bile ducts, originating from blunt trauma to the donor liver. Treatment was non-operative following recent reports of the successful management of intrahepatic bile duct injury in the stable trauma patient. This discussion adds to the limited literature available on the transplantation of injured donor livers, despite this being a relatively common practice. Further experience is needed in determining the appropriate criteria for the use of traumatized donor livers. Cholangiography carried out on the back table may help to determine if such injured livers are suitable for transplantation.

Orthotopic liver transplantation in a patient with carbamyl phosphate synthetase deficiency and cystic fibrosis

A 15-year-old female with carbamyl phosphate synthetase deficiency, cystic fibrosis, and cystic fibrosis-related diabetes underwent orthotopic cadaveric liver transplantation. Metabolic control was maintained during the procedure with nutritional support and the use of intravenous sodium phenylacetate and benzoate. Her postoperative course was complicated by seizures and a transient decline in her pulmonary function tests, which returned to preoperative levels within one year of the transplant. Now, four years post-transplant, her quality of life has dramatically improved. There are only four Canadian centres with paediatric liver transplantation programs. However, expert medical care for adults with inborn error of metabolism is even more limited, suggesting that access to adult medical care is one of the many factors to be considered when liver transplantation is contemplated for patients with metabolically unstable conditions.

Surgical staplers for vascular control of hepatic veins and portal structures in major hepatic resection

Phenomenal progress has occurred in the art of liver resection. Only a decade ago massive blood transfusion, liver failure, bile leak, or sepsis were alI frequent attendants of major resection, and intraoperative death from torrential bleeding from hepatic veins or vena cava was not uncommon. Now, major liver resection may be accomplished routinely without blood transfusion, and operative mortality of 0% to 2% is standard in expert hands. Uncontrolled hemorrhage remains the primary cause of intraoperative death. Mortality in the early postoperative period is usually related to delayed hemorrhage, inadequate hepatic reserve, or injury to vital blood supply or biliary drainage in the liver remnant.

Hydroquinone, a reactive metabolite of benzene, enhances interleukin-4 production in CD4+ T cells and increases immunoglobulin E levels in antigen-primed mice

Exposure to cigarette smoke is known to increase the risk of the development of allergic disease. The mechanism is not well understood. In this study, we determined the effect of hydroquinone (HQ), a major metabolite of benzene present in large quantities in cigarette tar, on interleukin-4 (IL-4) production by CD4+ T cells. HQ significantly enhanced IL-4 production by keyhole limpet haemocyanin (KLH)-primed CD4+ T cells in a dose-dependent manner. The enhancing effect of HQ on IL-4 production was maximal at a concentration of 50 micro m. It increased the level of IL-4 production approximately 10-fold. HQ enhanced IL-4 mRNA expression and also IL-4 gene promoter activity, suggesting that the enhancing effect of HQ on IL-4 production may occur at the transcriptional level. Furthermore, the injection of KLH-primed mice with HQ resulted in a significant increase in the levels of IL-4 and immunoglobulin E. These findings provide evidence that HQ, a major component of cigarette tar, may enhance allergic immune responses by inducing the production of IL-4 in CD4+ T cells.

Enhancement of 1 alpha,25-dihydroxyvitamin D(3)-induced differentiation of human leukaemia HL-60 cells into monocytes by parthenolide via inhibition of NF-kappa B activity

1. Transcription factors such as NF-kappa B provide powerful targets for drugs to use in the treatment of cancer. In this report parthenolide (PT), a sesquiterpene lactone of herbal remedies such as feverfew (Tanacetum parthenium) with NF-kappa B inhibitory activity, markedly increased the degree of human leukaemia HL-60 cell differentiation when simultaneously combined with 5 nM 1 alpha,25-dihydroxyvitamin D(3) (1,25-(OH)(2)D(3)). PT by itself did not induce HL-60 cell differentiation. 2. Cytofluorometric analysis indicated that PT stimulated 1,25-(OH)(2)D(3)-induced differentiation of HL-60 cells predominantly into monocytes. 3. Pretreatment of HL-60 cells with PT before the 1,25-(OH)(2)D(3) addition also potentiated the 1,25-(OH)(2)D(3)-induced HL-60 cell differentiation in both a dose- and a time-dependent manner, in which the enhanced levels of cell differentiation closely correlated with the inhibitory levels of NF-kappa B binding activity by PT. 4. In contrast, santonin, a sesquiterpene lactone without an inhibitory activity of NF-kappa B binding to the kappa B sites, did not enhance the 1,25-(OH)(2)D(3)-induced HL-60 cell differentiation. 5. In transfection experiments, PT enhanced 1,25-(OH)(2)D(3)-induced VDRE-dependent promoter activity. Furthermore, PT restored 1,25-(OH)(2)D(3)-induced VDRE-dependent promoter activity inhibited by TNF-alpha, an activator of NF-kappa B signalling pathway. 6. These results indicate that PT strongly potentiates the 1,25-(OH)(2)D(3)-induced HL-60 cell differentiation into monocytes via the inhibition of NF-kappa B activity and provide evidence that inhibition of NF-kappa B activation can be a pre-requisite to the efficient entry of promyelocytic leukaemia cells into a differentiation pathway.

The involvement of Ran GTPase in lipopolysaccharide endotoxin-induced responses

By functional cloning, we have established that Ran GTPase is involved in LPS-induced signal transduction. This has been accomplished by several functional comparisons of the two cDNAs, Lps(n)/Ran (or RanT/n) and Lps(d)/Ran (or RanC/d), which were isolated from cDNA libraries of LPS responder and hyporesponder mice, respectively. The letter n refers to the "normal" phenotype and the letter d refers to the "deficient" phenotype. Consistent with our previous results, more animal studies indicated that adenoviral transduction of RanC/d cDNA, but not RanT/n cDNA, into sensitive mice conferred significant resistance against endotoxin challenge. Thus the incorporation of RanC/d cDNA into gene therapy protocols as a therapeutic sequence remains very attractive. At steady state, hematopoietic cells transduced with RanC/d cDNA led to about a 10-fold increase in exogenous Ran protein compared with RanT/n cDNA. Furthermore, our cumulative data suggest that a slight elevation of Ran protein in B cells enhances LPS responsiveness, but the same elevation of Ran in macrophages does not. On the other hand, a high level of overexpression of Ran in both macrophages and B cells down-regulates LPS signal transduction. Thus LPS-induced signal transduction in macrophages and B cells is likely to occur via different signaling pathways.

Establishment of Porphyromonas gingivalis-specific T-cell lines from atherosclerosis patients

Porphyromonas gingivalis-specific T-cell lines were established from atherosclerotic lesions from two patients. T-cell lines were found to be a mixture of CD4+ and CD8+ T-cells producing variable amount of interferon-gamma, interleukin-4 and interleukin-10. The two patients have had a periodontal disease whose anti-P. gingivalis immunoglobulin G titers were significantly elevated, and P. gingivalis was the one of the predominantly cultivable microorganisms. This is the first report of the successful establishment of P. gingivalis-specific T-cell lines from atherosclerotic patients.

A single point mutation at the 3'-untranslated region of Ran mRNA leads to profound changes in lipopolysaccharide endotoxin-mediated responses

By functional cDNA expression cloning, we have previously established that Ran is important in lipopolysaccharide (LPS) signaling. This was achieved by functional comparison between two cDNAs, differing by a single base substitution within the 3'-untranslated region of the cDNA. This point mutation results in a striking RNA conformational change. No dramatic difference in total RNA at steady state could be found between the two molecules. However, at the protein level, RanC/d (from 870C mRNA) was 5-10-fold higher than RanT/n (from 870T mRNA) and this difference was not observed in non-hematopoietic cells transduced with the same vectors. This tissue-specific difference correlated with a difference in LPS endotoxin responses in corresponding hematopoietic cells. Importantly, the amounts of Ran- C/d and RanT/n proteins were similar initially but the difference became obvious with time. Both Ran proteins migrated from the cytoplasm to the nucleus, but Ran from RanC/d migrated faster than that of RanT/n. RanT/n protein preferentially remained in the cytoplasm and its overall amount was reduced at steady state, consistent with its degradation by intracellular proteases known to be involved in LPS-mediated signal transduction. As the two proteins are identical, the faster RanC/d nuclear localization and a preferred initial cytoplasmic RanT/n distribution suggest a difference in mRNA intracellular localization between the two molecules, as dictated by their RNA structural difference. By pulse-chase experiments, RanC/d proteins are more resistant to degradation than RanT/n protein; there also appear to have two populations of RanT/n proteins, one may reside in the cytoplasm and the other, in the nucleus. More RanC/d GTPase accumulated in the nuclei would conceivably alter the potency of signal transduction and therefore down-modulate LPS-mediated biological responses.

Inhibition of interleukin-12 production in lipopolysaccharide-activated mouse macrophages by parthenolide, a predominant sesquiterpene lactone in Tanacetum parthenium: involvement of nuclear factor-kappaB

Pharmacological control of interleukin-12 (IL-12) production may be a key therapeutic strategy for modulating immunological diseases dominated by type-1 cytokine responses. In this study, we investigated the effects of parthenolide, an anti-inflammatory sesquiterpene, on the production of IL-12 from mouse macrophages stimulated with lipopolysaccharide (LPS). Parthenolide potently inhibited the LPS-induced IL-12 production in a dose-dependent manner. The effect of parthenolide on IL-12 p40 promoter activation was analyzed by transfecting RAW264.7 monocytic cells with p40 promoter/luciferase constructs. The repressive effect mapped to a region in the p40 promoter containing a binding site for nuclear factor-kappaB (p40-kappaB). Furthermore, activation of macrophages by LPS resulted in markedly enhanced binding activity to the kappaB site, which significantly decreased upon addition of parthenolide. These results suggest that parthenolide-induced inhibition of IL-12 production in macrophages may explain some of the biological effects of parthenolide including its anti-inflammatory activity.

Inhibition of interleukin-12 production in lipopolysaccharide-activated mouse macrophages by hpyericin, an active component of Hypericum perforatum

Hypericin, an active component of Hypericum perforatum, was evaluated for the regulation of interleukin-12 (IL-12) production in mouse macrophages. Hypericin significantly inhibited IL-12 production in lipopolysaccharide-activated macrophages in a dose-dependent manner (IC50 = 1.45 micrograms/ml). Furthermore, hypericin potently inhibited the activation of IL-12 gene promoter, suggesting that hypericin negatively regulated IL-12 production at the transcription level. These results may explain some known biological activities of hypericin including its anti-rheumatic effect.

Capsaicin potentiates 1,25-dihydoxyvitamin D3- and all-trans retinoic acid-induced differentiation of human promyelocytic leukemia HL-60 cells

Human promyelocytic leukemia HL-60 cells are differentiated into monocytic or granulocytic lineage when treated with 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] or all-trans retinoic acid, respectively. In this study, the effect of capsaicin, an active component of the red pepper of the genus Capsocum, on cell differentiation was investigated in a HL-60 cell culture system. Treatment of HL-60 cells with 5-30 microg/ml capsaicin for 72 h inhibited cell proliferation and induced a small increase in cell differentiation. Interestingly, synergistic induction of HL-60 cell differentiation was observed when capsaicin was combined with either 5 nM 1,25-(OH)2D3 or 50 nM all-trans retinoic acid. Flow cytometric analysis indicated that combinations of 1,25-(OH)2D3 and capsaicin stimulated differentiation predominantly to monocytes whereas combinations of all-trans retinoic acid and capsaicin stimulated differentiation predominantly to granulocytes. Capsaicin enhanced protein kinase C activity in 1,25-(OH)2D3- and all-trans retinoic acid-treated HL-60 cells. In addition, inhibitors for protein kinase C [bisindolylmaleimide (GF-109203X), chelerythrine, 1-(5-isoquinolinesulfonyl)-2-methylpiperazine dihydrochloride (H-7)] and an inhibitor for extracellular signal-regulated kinase [2-(2'-amino-3'-methoxyphenyl)-oxanaphthalen-4-one (PD-098059)] significantly inhibited HL-60 cell differentiation induced by capsaicin in combination with either 1,25-(OH)2D3 or all-trans retinoic acid. These results indicate that capsaicin potentiates 1,25-(OH)2D3- or all-trans retinoic acid-induced HL-60 cell differentiation and that both protein kinase C and extracellular signal-regulated kinase are involved in the cell differentiation synergistically enhanced by capsaicin.

Specific association of Type I c-Abl with Ran GTPase in lipopolysaccharide-mediated differentiation

Each of several isoforms of c-Abl may be involved in different biological functions. Type I c-Abl has been shown to be involved in LPS-induced differentiation and Type IV c-Abl, apoptosis. Ran has recently been shown to be involved in LPS endotoxin signal transduction. Here we show that Type I c-Abl associates with Ran. Formation of this complex is specific, as Ran did not associate with the highly homologous Type IV c-Abl isoform. In non-stimulated lymphoid B cells, Type I c-Abl tyrosine kinase is inactive, whereas Type IV kinase is active. Formation of Type I c-Abl/Ran complex and activation of Type I c-Abl kinase activity are LPS dose-dependent. This complex is detectable in B cells of endotoxin-sensitive inbred mice but absent in B cells of endotoxin-resistant mice. These findings therefore suggest that Type I c-Abl and Ran are important targets in lipopolysaccharide-induced biological responses of hematopoietic cells.

EPIC tile flow and nitrate loss predictions for three Minnesota cropping systems

Subsurface tile drains are a key source of nitrate N (NO3-N) losses to streams in parts of the north central USA. In this study, the Erosion Productivity Impact Calculator (EPIC) model was evaluated by comparing measured vs. predicted tile flow, tile NO3-N loss, soil profile residual NO3-N, crop N uptake, and yield, using 4 yr of data collected at a site near Lamberton, MN, for three crop rotations: continuous corn (Zea mays L.) or CC, corn-soybean [Glycine max (L.) Merr.] or CS, and continuous alfalfa (Medicago sativa L.) or CA. Initially, EPIC was run using standard Soil Conservation Service (SCS) runoff curve numbers (CN2) for CC and CS; monthly variations were accurately tracked for tile flow (r2 = 0.86 and 0.90) and NO3-N loss (r2 = 0.69 and 0.52). However, average annual CC and CS tile flows were underpredicted by -32 and -34%, and corresponding annual NO3-N losses were underpredicted by -11 and -52%. Predicted average annual tile flows and NO3-N losses generally improved following calibration of the CN2; tile flow underpredictions were -9 and - 12%, whereas NO3-N losses were 0.6 and -54%. Adjusting a N parameter further improved predicted CS NO3-N losses. Predicted monthly tile flows and NO3-N losses for the CA simulation compared poorly with observed values (r2 values of 0.27 and 0.19); the annual drainage volumes and N losses were of similar magnitude to those measured. Overall, EPIC replicated the relative impacts of the three cropping systems on N fate.

Induction of immune hyporesponsiveness after portal vein immunization with ovalbumin

BACKGROUND

Previous work has demonstrated prolonged allograft survival after donor-specific portal vein immunization before the transplantation. The purpose of this study was to examine the potential mechanism of portal vein-induced hyporesponsiveness after portal vein immunization with the soluble protein ovalbumin.

METHODS

Balb/c mice were immunized with a portal vein injection of ovalbumin. After the immunization, in vivo delayed-type hypersensitivity response and in vitro proliferative response of ovalbumin-specific T cells were assessed to determine host immune response. Type 1 (IL-2, IL-12, IFN-gamma) and type 2 (IL-4, TGF-beta) regulatory cytokines were assessed by semiquantitative reverse transcriptase polymerase chain reaction. Sera anti-ovalbumin IgG, IgG1, and IgG2a were measured by enzyme-linked immunosorbent assay, and the antigen-presenting ability of liver nonparenchymal cells (NPCs) was assessed by T-cell proliferation to ovalbumin in vitro.

RESULTS

There was significant inhibition of ovalbumin-specific delayed-type hypersensitivity and T-cell proliferation in portal vein-immunized mice compared with intraperitoneal-immunized or control mice. Reverse transcriptase polymerase chain reaction analysis results showed that lymphocytes from portal vein-immunized mice exhibited decreased type 1 and increased type 2 cytokine messenger RNA expression compared with intraperitoneal-immunized or control animals. The type 2 cytokine response of lymphocytes from ovalbumin portal vein-immunized mice correlated with increased sera ovalbumin-IgG1 and decreased IgG2a. The results of an antigen-presenting assay revealed that liver NPCs were deficient antigen-presenting cells compared with adherent cells from heart or spleen.

CONCLUSIONS

Processing of ovalbumin by hepatic NPCs results in hyporesponsiveness to ovalbumin by an impaired type 1 cytokine response and a preferential shift toward a type 2 cytokine response, possibly because of defective antigen presentation by hepatic NPCs. Intrahepatic processing of antigen may play an important role in the development of strategies to reduce host immunoreactivity against transplanted allografts.

Expression of a truncated retroviral envelope gene enhances expression of normal cellular phenotypes

The envelope gene of Moloney murine leukemia virus (Mo-MLV) and its various functional domains have been studied extensively but not as much in terms of their biological effects on cell growth. In this study, we report the biological characterization of a truncated Mo-MLV envelope gene, LN11, which is devoid of a signal peptide. Its expression in various cell types, as compared to the control, enabled the transduced cells to assume a more normal phenotype, which is defined by an increase in contact inhibition and factor dependence, as well as reduced tumorigenicity. LN11-transduced fibroblasts exhibited a higher degree of contact inhibition, assumed a more flattened morphology and were more adherent compared to the control. In v-abl transformed hematopoietic cells, expression of LN11 resulted in slower cell growth, which was due to an enhanced dependence on exogenous growth factors. Enforced expression of LN11 also resulted in a slower rate of tumor development and a reduced tumor load. Thus, modification of a retroviral genome could have a significant impact on cell growth and development. This is one example where we need to consider the safety issue carefully when constructing retrovirus vectors for gene therapy.

Oxidized low density lipoprotein inhibits interleukin-12 production in lipopolysaccharide-activated mouse macrophages via direct interactions between peroxisome proliferator-activated receptor-gamma and nuclear factor-kappa B

Lipopolysaccharide (LPS) increases the production of interleukin-12 (IL-12) from mouse macrophages via a kappaB site within the IL-12 p40 promoter. In this study, we found that oxidized low density lipoprotein (oxLDL) inhibited this LPS-stimulated production of IL-12 in a dose-dependent manner while native LDL did not. OxLDL inhibited p40 promoter activation in monocytic RAW264.7 cells transiently transfected with p40 promoter/reporter constructs, and the repressive effect mapped to a region in the p40 promoter containing a binding site for nuclear factor-kappaB (NF-kappaB) (p40-kappaB). Activation of macrophages by LPS in the presence of oxLDL resulted in markedly reduced binding to the kappaB site, as demonstrated by the electrophoretic mobility shift assays. In contrast, native LDL did not inhibit the IL-12 p40 promoter activation and NF-kappaB binding to the kappaB sites, suggesting that oxidative modification of LDL was crucial for the inhibition of NF-kappaB-mediated IL-12 production. 9-Hydroxyoctadecadienoic acid, a major oxidized lipid component of oxLDL, significantly inhibited IL-12 production in LPS-stimulated mouse macrophages and also suppressed NF-kappaB-mediated activation in IL-12 p40 promoter. The NF-kappaB components p50 and p65 directly bound peroxisome proliferator-activated receptor-gamma (PPAR-gamma) in vitro. In cotransfections of CV-1 and HeLa cells, PPAR-gamma inhibited the NF-kappaB transactivation in an oxLDL-dependent manner. From these results, we propose that oxLDL-mediated suppression of the IL-12 production from LPS-activated mouse macrophages may, at least in part, involve both inhibition of the NF-kappaB-DNA interactions and physical interactions between NF-kappaB and PPAR-gamma.

De novo acute hepatitis B infection in a previously vaccinated liver transplant recipient due to a strain of HBV with a Met 133 Thr mutation in the "a" determinant

De novo HBV infection post-liver transplantation (LT) from an anti-HBc seropositive donor rarely presents as acute failure. We report a 42-year-old Caucasian female, HBsAg and anti-HBc seronegative, with primary biliary cirrhosis who received an allograft from a HBsAg negative, anti-HBc seropositive donor. The patient, previously vaccinated years pre-LT, was re-vaccinated against HBV and 1 year post-LT had an anti-HBs titre of 256 IU/l. Two years post-LT, elevated serum aminotransferases and worsening liver function with an INR of 2.0 developed. The HBsAg became positive, anti-HBs undetectable and serum HBV-DNA >2000 pg/ml by hybridisation assay. Liver biopsy revealed significant ballooning degeneration, piecemeal necrosis and positive immunostaining for HBsAg. Progressive liver failure developed followed by sepsis and terminal multi-organ failure. Subsequent analysis of the predominant HBV strain revealed mutations in the "a" determinant: Met 133 Thr (codon change ATG to ACG) and Asn 131 Thr.

CONCLUSION

' Acute de novo HBV infection from an anti-HBc sero-positive donor may occur long after LT despite protective anti-HBs titres post-vaccination secondary to the emergence of "a" determinant mutated strains of HBV.

Indications for liver transplantation in British Columbia's Aboriginal population: a 10-year retrospective analysis

OBJECTIVES

To study the indications for liver transplantation among British Columbia's First Nation population.

MATERIALS AND METHODS

A retrospective analysis of the British Columbia Transplant Society's database of Aboriginal and non-Aboriginal liver transplant recipients from 1989 to 1998 was undertaken. For primary biliary cirrhosis (PBC), the transplant assessment database (patients with and without transplants) was analyzed using a binomial distribution and compared with published census data regarding British Columbia's proportion of Aboriginal people.

RESULTS

Between 1989 and 1998, 203 transplantations were performed in 189 recipients. Fifteen recipients were Aboriginal (n=15; 7.9%). Among all recipients, the four most frequent indications for liver transplantation were hepatitis C virus (HCV) infection (n=57; 30.2%), PBC (n=34; 18.0%), alcohol (n=22; 11.6%) and autoimmune hepatitis (n=14; 7.4%). Indications for liver transplantation among Aboriginal people were PBC (n=8; 53.3%; P<0.001 compared with non-Aboriginal people), autoimmune hepatitis (n=4; 26.67%; P=0.017), acute failure (n=2; 13.3%) and HCV (n=1). Among all patients referred for liver transplantation with PBC (n=43), 29 (67.44%) were white and 11 (25.6%) were Aboriginal. A significant difference was found between the proportion of Aboriginal people referred for liver transplantation and the proportion of Aboriginal people in British Columbia (139,655 of 3,698,755 [3.8%]; 1996 Census, Statistics Canada) (P<0.001).

CONCLUSIONS

Aboriginal people in British Columbia are more likely to be referred for liver transplantation with a diagnosis of PBC but are less likely to receive a liver transplant because of HCV or alcohol than are non-Aboriginal people.