MHY446 induces apoptosis via reactive oxygen species-mediated endoplasmic reticulum stress in HCT116 human colorectal cancer cells

This study investigated the potential of a newly synthesized histone deacetylase (HDAC) inhibitor, MHY446, in inducing cell death in HCT116 colorectal cancer cells and compared its activity with that of suberoylanilide hydroxamic acid (SAHA), a well-known HDAC inhibitor. The results showed that MHY446 increased the acetylation of histones H3 and H4 and decreased the expression and activity of HDAC proteins in HCT116 cells. Additionally, MHY446 was confirmed to bind more strongly to HDAC1 than HDAC2 and inhibit its activity. In vivo experiments using nude mice revealed that MHY446 was as effective as SAHA in inhibiting HCT116 cell-grafted tumor growth. This study also evaluated the biological effects of MHY446 on cell survival and death pathways. The reactive oxygen species (ROS) scavenger N-acetyl-L-cysteine (NAC) confirmed that ROS play a role in MHY446-induced cell death by reducing poly(ADP-ribose) polymerase cleavage. MHY446 also induced cell death via endoplasmic reticulum (ER) stress by increasing the expression of ER stress-related proteins. NAC treatment decreased the expression of ER stress-related proteins, indicating that ROS mediate ER stress as an upstream signaling pathway and induce cell death. While MHY446 did not exhibit superior HDAC inhibition efficacy compared to SAHA, it is anticipated to provide innovative insights into the future development of therapeutic agents for human CRC by offering novel chemical structure-activity relationship-related information.

Pathogenesis, Intervention, and Current Status of Drug Development for Sarcopenia: A Review

Sarcopenia refers to the loss of muscle strength and mass in older individuals and is a major determinant of fall risk and impaired ability to perform activities of daily living, often leading to disability, loss of independence, and death. Owing to its impact on morbidity, mortality, and healthcare expenditure, sarcopenia in the elderly has become a major focus of research and public policy debates worldwide. Despite its clinical importance, sarcopenia remains under-recognized and poorly managed in routine clinical practice, partly owing to the lack of available diagnostic testing and uniform diagnostic criteria. Since the World Health Organization and the United States assigned a disease code for sarcopenia in 2016, countries worldwide have assigned their own disease codes for sarcopenia. However, there are currently no approved pharmacological agents for the treatment of sarcopenia; therefore, interventions for sarcopenia primarily focus on physical therapy for muscle strengthening and gait training as well as adequate protein intake. In this review, we aimed to examine the latest information on the epidemiology, molecular mechanisms, interventions, and possible treatments with new drugs for sarcopenia.

Recent Developments in Combination Chemotherapy for Colorectal and Breast Cancers with Topoisomerase Inhibitors

DNA topoisomerases are important enzymes that stabilize DNA supercoiling and resolve entanglements. There are two main types of topoisomerases in all cells: type I, which causes single-stranded DNA breaks, and type II, which cuts double-stranded DNA. Topoisomerase activity is particularly increased in rapidly dividing cells, such as cancer cells. Topoisomerase inhibitors have been an effective chemotherapeutic option for the treatment of several cancers. In addition, combination cancer therapy with topoisomerase inhibitors may increase therapeutic efficacy and decrease resistance or side effects. Topoisomerase inhibitors are currently being used worldwide, including in the United States, and clinical trials on the combination of topoisomerase inhibitors with other drugs are currently underway. The primary objective of this review was to comprehensively analyze the current clinical landscape concerning the combined application of irinotecan, an extensively investigated type I topoisomerase inhibitor for colorectal cancer, and doxorubicin, an extensively researched type II topoisomerase inhibitor for breast cancer, while presenting a novel approach for cancer therapy.

MHY2251, a New SIRT1 Inhibitor, Induces Apoptosis via JNK/p53 Pathway in HCT116 Human Colorectal Cancer Cells

Sirtuins (SIRTs) belong to the nicotinamide adenine dinucleotide (NAD+)-dependent class III histone deacetylase family. They are key regulators of cellular and physiological processes, such as cell survival, senescence, differentiation, DNA damage and stress response, cellular metabolism, and aging. SIRTs also influence carcinogenesis, making them potential targets for anticancer therapeutic strategies. In this study, we investigated the anticancer properties and underlying molecular mechanisms of a novel SIRT1 inhibitor, MHY2251, in human colorectal cancer (CRC) cells. MHY2251 reduced the viability of various human CRC cell lines, especially those with wild-type TP53. MHY2251 inhibited SIRT1 activity and SIRT1/2 protein expression, while promoting p53 acetylation, which is a target of SIRT1 in HCT116 cells. MHY2251 treatment triggered apoptosis in HCT116 cells. It increased the percentage of late apoptotic cells and the sub-G1 fraction (as detected by flow cytometric analysis) and induced DNA fragmentation. In addition, MHY2251 upregulated the expression of FasL and Fas, altered the ratio of Bax/Bcl-2, downregulated the levels of pro-caspase-8, -9, and -3 proteins, and induced subsequent poly(ADP-ribose) polymerase cleavage. The induction of apoptosis by MHY2251 was related to the activation of the caspase cascade, which was significantly attenuated by pre-treatment with Z-VAD-FMK, a pan-caspase inhibitor. Furthermore, MHY2251 stimulated the phosphorylation of c-Jun N-terminal kinase (JNK), and MHY2251-triggered apoptosis was blocked by pre-treatment with SP600125, a JNK inhibitor. This finding indicated the specific involvement of JNK in MHY2251-induced apoptosis. MHY2251 shows considerable potential as a therapeutic agent for targeting human CRC via the inhibition of SIRT1 and activation of JNK/p53 pathway.

Limited liver resections in the posterosuperior segments: international multicentre propensity score-matched and coarsened exact-matched analysis comparing the laparoscopic and robotic approaches

Background

Limited liver resections (LLRs) for tumours located in the posterosuperior segments of the liver are technically demanding procedures. This study compared outcomes of robotic (R) and laparoscopic (L) LLR for tumours located in the posterosuperior liver segments (IV, VII, and VIII).

Methods

This was an international multicentre retrospective analysis of patients who underwent R-LLR or L-LLR at 24 centres between 2010 and 2019. Patient demographics, perioperative parameters, and postoperative outcomes were analysed; 1 : 3 propensity score matching (PSM) and 1 : 1 coarsened exact matching (CEM) were performed.

Results

Of 1566 patients undergoing R-LLR and L-LLR, 983 met the study inclusion criteria. Before matching, 159 R-LLRs and 824 L-LLRs were included. After 1 : 3 PSM of 127 R-LLRs and 381 L-LLRs, comparison of perioperative outcomes showed that median blood loss (100 (i.q.r. 40–200) versus 200 (100–500) ml; P = 0.003), blood loss of at least 500 ml (9 (7.4 per cent) versus 94 (27.6 per cent); P < 0.001), intraoperative blood transfusion rate (4 (3.1 per cent) versus 38 (10.0 per cent); P = 0.025), rate of conversion to open surgery (1 (0.8 per cent) versus 30 (7.9 per cent); P = 0.022), median duration of Pringle manoeuvre when applied (30 (20–46) versus 40 (25–58) min; P = 0.012), and median duration of operation (175 (130–255) versus 224 (155–300); P < 0.001) were lower in the R-LLR group compared with the L-LLR group. After 1 : 1 CEM of 104 R-LLRs with 104 L-LLRs, R-LLR was similarly associated with significantly reduced blood loss and a lower rate of conversion to open surgery.

Conclusion

Based on a matched analysis of well selected patients, both robotic and laparoscopic access could be undertaken safely with good outcomes for tumours in the posterosuperior liver segments.

Novel SIRT Inhibitor, MHY2256, Induces Cell Cycle Arrest, Apoptosis, and Autophagic Cell Death in HCT116 Human Colorectal Cancer Cells

We examined the anticancer effects of a novel sirtuin inhibitor, MHY2256, on HCT116 human colorectal cancer cells to investigate its underlying molecular mechanisms. MHY2256 significantly suppressed the activity of sirtuin 1 and expression levels of sirtuin 1/2 and stimulated acetylation of forkhead box O1, which is a target protein of sirtuin 1. Treatment with MHY2256 inhibited the growth of the HCT116 (TP53 wild-type), HT-29 (TP53 mutant), and DLD-1 (TP53 mutant) human colorectal cancer cell lines. In addition, MHY2256 induced G0/G1 phase arrest of the cell cycle progression, which was accompanied by the reduction of cyclin D1 and cyclin E and the decrease of cyclin-dependent kinase 2, cyclin-dependent kinase 4, cyclin-dependent kinase 6, phosphorylated retinoblastoma protein, and E2F transcription factor 1. Apoptosis induction was shown by DNA fragmentation and increase in late apoptosis, which were detected using flow cytometric analysis. MHY2256 downregulated expression levels of procaspase-8, -9, and -3 and led to subsequent poly(ADP-ribose) polymerase cleavage. MHY2256-induced apoptosis was involved in the activation of caspase-8, -9, and -3 and was prevented by pretreatment with Z-VAD-FMK, a pan-caspase inhibitor. Furthermore, the autophagic effects of MHY2256 were observed as cytoplasmic vacuolation, green fluorescent protein-light-chain 3 punctate dots, accumulation of acidic vesicular organelles, and upregulated expression level of light-chain 3-II. Taken together, these results suggest that MHY2256 could be a potential novel sirtuin inhibitor for the chemoprevention or treatment of colorectal cancer or both.

P3637Relationship between serial measurements of NT-proBNP and cardiovascular events in patients with acute coronary syndrome

Background

Increased level of natriuretic peptides has been known as an important predictors of adverse cardiovascular (CV) outcomes in patients with acute coronary syndrome (ACS). We sought to evaluate clinical implication of N-terminal pro-brain natriuretic peptide (NT-proBNP) measured at initial and follow-up periods.

Methods

Serial NT-proBNP levels (on-admission and one-month post-PCI) were measured in ACS patients undergoing PCI (n=2,290). High NT-proBNP levels were determined according to the predefined age-specific criteria. Patients were stratified into 4 groups according to NT-proBNP levels (on-admission & one-month): (1) normal-normal group (n=1234, 53.9%); (2) high–normal group (n=257, 11.2%); (3) normal-high group (n=376, 16.4%); and (4) high-high group (n=423, 18.5%). Clinical events were defined as all-cause death and MACE (a composite of CV death, non-fatal MI, and ischemic stroke).

Results

With a median follow-up of 35.9 (IQR: 16.8, 54.5) months, all-cause death and MACE were occurred in 4.1% and 7.2%, respectively. NT-proBNP on-admission vs. at one-month did not differ significantly (median 391.6 [IQR: 143.9, 1402.3] vs. median 619.1 [IQR 240.1, 1616.1]; p=0.622), but the prevalence of high NT-proBNP was increased over time (25.3% to 34.9%; p<0.001). The rates of all-cause death and MACE significantly increased only in the high-high group compared with other groups (log-rank test, all p values <0.001, Figure). After adjustment, the high-high group remained significantly risky in terms with the occurrence of all-cause death (HR, 2.99; 95% CI, 1.65 to 5.41; p<0.001) and MACE (HR, 1.96; 95% CI, 1.28 to 3.01; p=0.002).

Figure 1

Conclusion

Serial measurements of NT-proBNP at on-admission and follow-up can help to stratify the risks of all-cause death and adverse CV events following PCI in ACS patients. About two-fifths of patients having high NT-proBNP level during hospitalization can be classified into the low-risk group for all-cause death and adverse CV events.

Acknowledgement/Funding

None

VDJ Gene Usage of B Cell Receptors in Peripheral Blood of ABO-incompatible Kidney Transplantation Patients

INTRODUCTION

B cell subtypes and immunoglobulin variable (V), diversity (D), joining (J) gene segment usage of B cell receptors in ABO-incompatible (ABOi) kidney transplantation (KT) in comparison to ABO-compatible KT have not been studied. The aims of this study were to analyze the VDJ gene segment usages of B cell receptors in peripheral blood of ABOi KT recipients.

METHODS

Eighteen ABOi KT patients with accommodation (ABOiA), 10 ABO-compatible stable KT patients (ABOcS), and 10 ABOi KT patients with biopsy-proven acute antibody-mediated rejection (ABOiR) at day 10 after transplantation were selected. Complete transcriptomes of their peripheral blood samples were sequenced and analyzed through RNA sequencing.

RESULTS

By family, immunoglobulin heavy chain variable 3 (IGHV3), immunoglobulin light kappa chain variable 1 (IGKV1), immunoglobulin light lambda chain variable 2 (IGLV2), and immunoglobulin light lambda chain joining 3 (IGLJ3) gene segments were most frequently used in all groups, and their usage was not statistically different among the three groups except for IGHV3 and IGKV1. IGKV1 was more frequently used in the ABOiA group than in the ABOcS group. According to individual gene segments, IGHV3-7, IGHV3-15, IGHV4-59, IGKV3-11, IGLV1-44, IGLV2-14, IGLV4-69, and IGLV7-46 were more frequently used in the ABOcS group than other groups, and IGKV3-7 was more frequently used in the ABOiR group than other groups. IGLV5-52 and IGLV7-43 were more frequently used in the ABOiA group than in ABOcS group.

CONCLUSIONS

Our findings suggest that RNA sequencing transcriptomic analyses of peripheral blood can provide information on the VDJ gene usage of B cell receptors and the mechanisms of accommodation and immune reaction in ABOi KT.

MHY451 induces cell cycle arrest and apoptosis by ROS generation in HCT116 human colorectal cancer cells

Colorectal cancer (CRC) is the third most frequently diagnosed cancer and cause of cancer-related deaths. Despite advancements in conventional therapeutic approaches to CRC, most patients with CRC die of their disease. There is a need to develop novel therapeutic agents for this malignancy. Therefore, the present study aimed to examine the anticancer effects and elucidate the underlying mechanism of MHY451 in HCT116 human colorectal cancer cells. Treatment with MHY451 inhibited cell growth in a time- and concentration-dependent manner. MHY451 increased the accumulation of cell cycle progression at the G2/M phase. This agent decreased the protein level of cyclin B1 and its activating partners, Cdc25c and Cdc2, whereas it increased the cell cycle inhibitor p21WAF/CIP. The induction of apoptosis was observed by decreased viability, cleavage of poly(ADP-ribose) polymerase (PARP), alteration in the ratio of Bax/Bcl-2 protein expression and reduction of procaspase-8 and -9. Pretreatment with Z-VAD-FMK, a pan-caspase inhibitor, inhibited MHY451-induced apoptosis, indicating that apoptotic cell death by MHY451 was mediated through caspases. Moreover, the apoptotic effect of MHY451 was reactive oxygen species (ROS)-dependent, evidenced by the inhibition of MHY451-induced PARP cleavage and ROS generation by N-acetylcysteine-induced ROS scavenging. Taken together, these results demonstrate that MHY451 exerts anticancer effects by regulating the cell cycle, inducing apoptosis through caspase activation and generating ROS. These results suggest that MHY451 has considerable potential for chemoprevention or treatment of CRC or both.

Serum 25-hydroxyvitamin D cutoffs for functional bone measures in postmenopausal osteoporosis

This study sought to determine the minimal serum 25-hydroxyvitamin D [25(OH)D] concentration required to maintain bone health in postmenopausal women with low bone mass. A serum 25(OH)D concentration of 20 ng/mL rather than 30 ng/mL was appropriate for bone health.

INTRODUCTION

There is no consensus on the minimal serum 25-hydroxyvitamin D [25(OH)D] concentration required to maintain bone health. The aim of this study was to investigate the relationship between 25(OH)D measured via liquid chromatography-mass spectrometry (LC-MS/MS), which is the current gold standard, and biochemical markers of bone turnover, PTH, and bone mineral densitometry (BMD).

METHODS

The medical records of 750 postmenopausal women newly diagnosed with osteoporosis or osteopenia at Samsung Medical Center from 2009 to 2014 were investigated. Subjects were divided into four groups according to serum 25(OH)D concentration: <10, 10-20, 20-30, and ≥30 ng/mL. Serum concentrations of bone-specific alkaline phosphatase (BS-ALP), carboxy-terminal cross-linking telopeptide of type 1 collagen (CTx), intact PTH (iPTH), and BMD were compared among the four groups using analysis of covariance. Thresholds of 25(OH)D were then assessed using spline plots and locally weighted regression smoothing (LOESS) plots.

RESULTS

25(OH)D was negatively correlated with serum BS-ALP, CTx, and iPTH. Only femur neck and total femur BMD had significant positive relationships with 25(OH)D. Cutoff values of 11.9 and 9.7 ng/mL were estimated from the spline plots of femur neck and total femur BMD, respectively. For iPTH, the LOESS plot showed a steep decrease to a serum 25(OH)D concentration of about 20 ng/mL, followed by a plateau.

CONCLUSIONS

According to this study, a serum 25(OH)D concentration of 20 ng/mL, rather than 30 ng/mL, was appropriate for bone health.

Serous cystic neoplasm of the pancreas: a multinational study of 2622 patients under the auspices of the International Association of Pancreatology and European Pancreatic Club (European Study Group on Cystic Tumors of the Pancreas)

OBJECTIVES

Serous cystic neoplasm (SCN) is a cystic neoplasm of the pancreas whose natural history is poorly known. The purpose of the study was to attempt to describe the natural history of SCN, including the specific mortality.

DESIGN

Retrospective multinational study including SCN diagnosed between 1990 and 2014.

RESULTS

2622 patients were included. Seventy-four per cent were women, and median age at diagnosis was 58 years (16-99). Patients presented with non-specific abdominal pain (27%), pancreaticobiliary symptoms (9%), diabetes mellitus (5%), other symptoms (4%) and/or were asymptomatic (61%). Fifty-two per cent of patients were operated on during the first year after diagnosis (median size: 40 mm (2-200)), 9% had resection beyond 1 year of follow-up (3 years (1-20), size at diagnosis: 25 mm (4-140)) and 39% had no surgery (3.6 years (1-23), 25.5 mm (1-200)). Surgical indications were (not exclusive) uncertain diagnosis (60%), symptoms (23%), size increase (12%), large size (6%) and adjacent organ compression (5%). In patients followed beyond 1 year (n=1271), size increased in 37% (growth rate: 4 mm/year), was stable in 57% and decreased in 6%. Three serous cystadenocarcinomas were recorded. Postoperative mortality was 0.6% (n=10), and SCN's related mortality was 0.1% (n=1).

CONCLUSIONS

After a 3-year follow-up, clinical relevant symptoms occurred in a very small proportion of patients and size slowly increased in less than half. Surgical treatment should be proposed only for diagnosis remaining uncertain after complete workup, significant and related symptoms or exceptionally when exists concern with malignancy. This study supports an initial conservative management in the majority of patients with SCN.

TRIAL REGISTRATION NUMBER

IRB 00006477.

Long-term control of diabetes in immunosuppressed nonhuman primates (NHP) by the transplantation of adult porcine islets

Pig islets are an alternative source for islet transplantation to treat type 1 diabetes (T1D), but reproducible curative potential in the pig-to-nonhuman primate (NHP) model has not been demonstrated. Here, we report that pig islet grafts survived and maintained normoglycemia for >6 months in four of five consecutive immunosuppressed NHPs. Pig islets were isolated from designated pathogen-free (DPF) miniature pigs and infused intraportally into streptozotocin-induced diabetic rhesus monkeys under pretreatment with cobra venom factor (CVF), anti-thymocyte globulin (ATG) induction and maintenance with anti-CD154 monoclonal antibody and low-dose sirolimus. Ex vivo expanded autologous regulatory T cells were adoptively transferred in three recipients. Blood glucose levels were promptly normalized in all five monkeys and normoglycemia (90-110 mg/dL) was maintained for >6 months in four cases, the longest currently up to 603 days. Intravenous glucose tolerance tests during the follow-up period showed excellent glucose disposal capacity and porcine C-peptide responses. Adoptive transfer of autologous regulatory T cells was likely to be associated with more stable and durable normoglycemia. Importantly, the recipients showed no serious adverse effects. Taken together, our results confirm the clinical feasibility of pig islet transplantation to treat T1D patients without the need for excessive immunosuppressive therapy.

Portal vein patency after pancreatoduodenectomy for periampullary cancer

BACKGROUND

The fate of the portal vein (PV) after pancreatoduodenectomy, especially its long-term patency and associated complications, has received little attention. The aim of this study was to explore the long-term patency rate of the PV after pancreatoduodenectomy, focusing on risk factors for PV stenosis/occlusion and associated complications.

METHODS

Serial CT images of patients who underwent pancreatoduodenectomy for periampullary cancer between January 2000 and June 2012 in a single institution were evaluated for PV stenosis or occlusion.

RESULTS

A total of 826 patients were enrolled. The PV stenosis/occlusion rate after pancreatoduodenectomy was 19.6 per cent and the 5-year patency rate 69.9 per cent. The most frequent cause of PV stenosis/occlusion was local recurrence followed by postoperative change and PV thrombosis. Patients who underwent PV resection had a higher PV stenosis/occlusion rate than those who did not (51 versus 17.4 per cent; P < 0.001). The 3-year patency rate was highest in patients with cancer of the ampulla of Vater and lowest in patients with pancreatic cancer (91.9 versus 55.5 per cent respectively; P < 0.001). Multivariable analysis showed that risk factors for PV stenosis/occlusion included primary tumour location, chemoradiotherapy and PV resection. PV stenosis or occlusion without disease recurrence was observed in 17.3 per cent of the patients. PV resection and grade B or C pancreatic fistula were independent risk factors for PV stenosis/occlusion. Among 162 patients with PV stenosis or occlusion, five (3.1 per cent) had fatal recurrent gastrointestinal bleeding.

CONCLUSION

PV stenosis or occlusion is common after pancreatoduodenectomy, particularly if the PV has been resected and/or chemoradiotherapy was given after surgery. Although recurrence is the most frequent cause of PV stenosis/occlusion, this complication is found in a significant proportion of patients without disease recurrence.

Relative adrenal insufficiency in chronic liver disease: its prevalence and effects on long-term mortality

BACKGROUND

The relationship between relative adrenal insufficiency (RAI) and chronic liver disease is unclear.

AIM

To determine the frequency with which RAI is observed in noncritically ill patients at various stages of chronic liver disease, and the correlation between RAI and disease severity and long-term mortality.

METHODS

In total, 71 non-critically ill patients with liver cirrhosis (n = 54) and chronic hepatitis (n = 17) were evaluated prospectively. A short stimulation test (SST) with 250 μg of corticotrophin was performed to detect RAI. RAI was defined as an increase in serum cortisol of <9 μg/dL in patients with a basal total cortisol of <35 μg/dL.

RESULTS

RAI was observed in only 13 (24.1%) of 54 patients with cirrhosis. Compared to those without RAI, cirrhotic patients with RAI had significantly higher Child-Turcotte-Pugh score (10.3 ± 1.7 vs. 7.1 ± 1.8, mean ± s.d., P < 0.001) and Model for End-Stage Liver Disease score (14.5 ± 6.6 vs. 9.4 ± 3.7, P = 0.017). The cortisol response to corticotropin was negatively correlated with the severity of cirrhosis (P < 0.05). In addition, the mortality rate was higher in cirrhotic patients with RAI (69.2%) than in those without RAI (4.9%; P < 0.001) during the follow-up period of 20.1 ± 13.5 months (range, 5.8-51.1 months). The cumulative 1-year survival rates in cirrhotic patients with and without RAI were 69.2% and 95.0%, respectively (P = 0.05), while the corresponding cumulative 3-year survival rates were 0% and 95.0% (P < 0.001).

CONCLUSIONS

Relative adrenal insufficiency is more commonly observed in those with severe cirrhosis, and is clearly associated with more advanced liver disease and a shortened long-term survival. This suggests that relative adrenal insufficiency is an independent prognostic factor in non-critically ill patients with cirrhosis.

Anti-inflammatory effects of betaine on AOM/DSS‑induced colon tumorigenesis in ICR male mice

Betaine is an important human nutrient obtained from various foods and studies in animals and humans have provided results suggesting their pathogenesis of various chronic diseases and points to a role in risk assessment and disease prevention. However, the molecular mechanisms of its activity remain poorly understood and warrant further investigation. This study was performed to investigate the anti-inflammation and tumor preventing capacity of betaine on colitis-associated cancer in mice. In in vivo experiments, we induced colon tumors in mice by azoxymethane (AOM) and dextran sulfate sodium (DSS) and evaluated the effects of betaine on tumor growth. Administration with betaine significantly decreased the incidence of tumor formation with downregulation of inflammation. Treatment with betaine inhibited ROS generation and GSSG concentration in colonic mucosa. Based on the qPCR data, administration of betaine inhibited inflammatory cytokines such TNF-α, IL-6, iNOS and COX-2. In in vitro experiments, LPS-induced NF-κB and inflammatory-related cytokines were inhibited by betaine treatment in RAW 264.7 murine macrophage cells. Our findings suggest that betaine is one of the candidates for the prevention of inflammation-associated colon carcinogenesis.

Staging accuracy of endoscopic ultrasound performed by nonexpert endosonographers in patients with resectable esophageal squamous cell carcinoma: is it possible?

The accuracy of endoscopic ultrasound (EUS) is operator-dependent. According to learning curve study, the accuracy of EUS T-staging for esophageal cancer has been reported to be greater in an investigator who had performed at least 100 EUS examinations. We determined comparative study regarding T-staging accuracy of EUS for esophageal squamous cell carcinoma between expert and nonexpert endoscopic ultrasonographers. We retrospectively identified 73 consecutive patients with esophageal squamous cell carcinoma who underwent EUS and endoscopic mucosal resection, endoscopic submucosal dissection, or surgery. EUS was performed by expert (Group 1) and nonexpert (Group 2) endoscopic ultrasonographers in multitertiary hospitals. Groups 1 and 2 were 37 and 36 patients during 2005-2011, respectively. Forty-two patients (57.5%) of the overall patients underwent surgical exploration. Correct endoscopic ultrasonographic T-staging of Group 1 was observed in 34 (91.9%) patients, while that of Group 2 was observed in 26 (72.2%) patients. And there was significant difference in correct endoscopic ultrasonographic T-staging between Group 1 and Group 2 (P = 0.035). The incorrect endoscopic ultrasonographic T-staging of Group 1 were three cases that were overstaging (8.1%), but in Group 2 there were seven overstaging (19.4%) and three understaging (8.3%). There was no significant difference in overstaging or understaging of incorrect endoscopic ultrasonographic T-staging between Group 1 and Group 2 (P = 0.528). This study first provides evidence that endoscopic ultrasonographic T-staging of nonexpert endoscopic ultrasonographers was inferior to be correct, compared with that of expert endoscopic ultrasonographers. EUS staging for esophageal cancer should be performed by expert endoscopic ultrasonographers to provide appropriate management strategy.

A novel hydroxamic acid derivative, MHY218, induces apoptosis and cell cycle arrest through downregulation of NF-κB in HCT116 human colon cancer cells

Colorectal cancer (CRC) is one of the most common malignant diseases and frequent cause of cancer deaths in the world. In spite of the significant advances in conventional therapeutic approaches to CRC, most patients ultimately die of their disease. There is a need to develop novel preventive approaches for this malignancy. This study was carried out to investigate the anticancer effect of MHY218, a hydroxamic acid derivative, in HCT116 human colon cancer cells. Treatment of cells with MHY218 resulted in growth inhibition and induction of apoptosis in a concentration-dependent manner. MHY218 induced G2/M phase arrest in the cell cycle progression which was observed by flow cytometry analysis, and a decrease in the protein expression of cyclin B1 and its activating partners Cdc25C and Cdc2. MHY218 also caused an increase in the expression levels of p21(WAF1/CIP1), a G2/M phase inhibitor, in a p53-independent pathway. The induction of apoptosis was observed by decreased viability, DNA fragmentation, cleavage of poly(ADP-ribose) polymerase, alteration in the ratio of Bax/Bcl-2 protein expression, and activation of caspase-3, -8 and -9. In addition, MHY218 treatment showed downregulation of the expression levels of the transcription factor nuclear factor-kappa B (NF-κB) in the nucleus, which has been reported to be implicated in the apoptotic cell death of several types of cancer cells, suppression of TNF-α-induced NF-κB activation, inhibition of cyclooxygenase-2 expression, repression of matrix metalloproteinase-9 activation and decrease of 5-lipoxygenase in a concentration-dependent manner. These results suggest that MHY218 may be a useful candidate to be used in the chemoprevention and/or treatment of colon cancer.

Baicalein, an active component of Scutellaria baicalensis Georgi, induces apoptosis in human colon cancer cells and prevents AOM/DSS-induced colon cancer in mice

Flavonoids have been demonstrated to provide health benefits in humans. Baicalein (5,6,7-trihydroxyflavone) is a phenolic flavonoid compound derived mainly from the root of Scutellaria baicalensis Georgi, a medicinal plant traditionally used in oriental medicine. Baicalein is widely used in Korean and Chinese herbal medicines as anti-inflammatory and anticancer therapy. However, the molecular mechanisms of its activity remain poorly understood and warrant further investigation. This study was performed to investigate the anticancer effect of baicalein on HCT116 human colon cancer cells and the tumor preventing capacity of baicalein on colitis-associated cancer in mice. In in vivo experiments, we induced colon tumors in mice by azoxymethane (AOM) and dextran sulfate sodium (DSS) and evaluated the effects of baicalein on tumor growth. Baicalein treatment on HCT116 cells resulted in a concentration-dependent inhibition of cell growth and induction of apoptotic cell death. The induction of apoptosis was determined by morphological changes and cleavage of poly(ADP-ribose) polymerase. Baicalein also suppressed the activation of NF-κB through PPARγ activation. These results indicate that the anti-inflammatory effects of baicalein may be mediated through PPARγ activation. Finally, administration with baicalein significantly decreased the incidence of tumor formation with inflammation. Our findings suggest that baicalein is one of the candidates for the prevention of inflammation-associated colon carcinogenesis.

Novel dihydrobenzofuro[4,5-b][1,8]naphthyridin-6-one derivative, MHY-449, induces apoptosis and cell cycle arrest in HCT116 human colon cancer cells

Colorectal cancer (CRC) is the second most frequent cancer in men and the third most common cancer in women in Korea. In spite of the significant advances in conventional therapeutic approaches to CRC, most patients ultimately die of their disease. There is a need to develop novel preventive approaches for this malignancy. This study was carried out to investigate the anticancer effect of the diastereoisomeric compounds, MHY-449 and MHY-450, novel dihydrobenzofuro[4,5-b][1,8]naphthyridin-6-one derivatives, on HCT116 human colon cancer cells. MHY-449 exhibited more potent cytotoxicity than MHY-450, against HCT116 cells. Treatment of cells with MHY-449 resulted in growth inhibition and induction of apoptosis in a concentration-dependent manner, and inhibition of proliferation in a time-dependent manner. The induction of apoptosis was observed by decreased cell viability, DNA fragmentation, activation of protein levels involved in death receptors. Moreover, activation of caspase-3, -8 and -9 and cleavage of poly(ADP-ribose) polymerase and alteration in the ratio of Bax/Bcl-2 protein expression was observed. MHY-449 induced G2/M phase arrest in the cell cycle progression which was observed by flow cytometry analysis, and a decrease in the protein expression of cyclin B1 and its activating partners Cdc25c and Cdc2. MHY-449 also caused increase in the expression levels of p53, a tumor suppressor gene, and p21WAF1/CIP and p27KIP, G2/M phase inhibitors. These results suggest that MHY-449 may be a useful candidate for chemo-prevention and/or treatment of colon cancer.

Aspirin enhances doxorubicin-induced apoptosis and reduces tumor growth in human hepatocellular carcinoma cells in vitro and in vivo

Combined therapy with multiple drugs is a common practice in the treatment of cancer, which can achieve better therapeutic effects than a single drug, and can reduce the side effects as well as drug resistance. This study aimed to determine whether aspirin (ASA) shows synergism with doxorubicin (DOX) in HepG2 human hepatocellular carcinoma cells in vitro and in a HepG2 cell xenograft model in BALB/c nude mice. When treated in combination, DOX (0.25 nmol/ml) and ASA (5 µmol/ml) produced strong synergy in growth inhibition, cell cycle arrest and importantly, apoptosis in vitro in comparison to single treatments. Moreover, ASA (100 mg/kg/day orally) and DOX (1.2 mg/kg biweekly ip) induced synergistic antitumor activity in the HepG2 cell xenograft model in nude mice. Therefore, the combination of ASA and DOX could be used as a novel combination regimen which provides a strong anticancer synergy in the treatment of hepatocellular carcinoma.

The influence of interval between conization and laparoscopic radical hysterectomy on the morbidity of patients with cervical cancer

OBJECTIVE

To evaluate the correlations between postoperative sequelae and the intervals between conization and subsequent laparoscopic radical hysterectomy (LRH) and pelvic lymphadenectomy in patients with cervical cancer.

MATERIALS AND METHODS

A retrospective study was conducted in a tertiary care university hospital. The medical records of cervical cancer patients undergoing LRH and pelvic lymphadenectomy between April 2005 and August 2011 were reviewed. The subjects were divided into three groups according to time from conization to LRH: group 1 (within six weeks, n = 17), group 2 (> six weeks, n = 38), and group 3 (no previous conization, n = 40).

RESULTS

The three groups showed no significant differences with respect to patient and tumor characteristics, intraoperative variables such as surgical time, blood loss, conversion to laparotomy, and perioperative morbidity, while the complications in group 1 showed a significant difference compared to groups 2 and 3.

CONCLUSIONS

LRH is feasible for the treatment of cervical cancer patients with previous conization and the appropriate time interval is after six weeks. A careful separation of the bladder and ureters from the cervix is recommended to minimize morbidity associated with this surgery.

Aspirin induces apoptosis in vitro and inhibits tumor growth of human hepatocellular carcinoma cells in a nude mouse xenograft model

Nonsteroidal anti-inflammatory drugs (NSAIDs) are known to induce apoptosis in a variety of cancer cells, including colon, prostate, breast and leukemia. Among them, aspirin, a classical NSAID, shows promise in cancer therapy in certain types of cancers. We hypothesized that aspirin might affect the growth of liver cancer cells since liver is the principal site for aspirin metabolism. Therefore, we investigated the effects of aspirin on the HepG2 human hepatocellular carcinoma cell line in vitro and the HepG2 cell xenograft model in BALB/c nude mice. We found that treatment with aspirin inhibited cell growth and induced apoptosis involving both extrinsic and intrinsic pathways as measured by DNA ladder formation, alteration in the Bax/Bcl-2 ratio, activation of the caspase activities and related protein expressions. In vivo antitumor activity assay also showed that aspirin resulted in significant tumor growth inhibition compared to the control. Oral administration of aspirin (100 mg/kg/day) caused a significant reduction in the growth of HepG2 tumors in nude mice. These findings suggest that aspirin may be used as a promising anticancer agent against liver cancer.

Amyloid vs FDG-PET in the differential diagnosis of AD and FTLD

OBJECTIVE

To compare the diagnostic performance of PET with the amyloid ligand Pittsburgh compound B (PiB-PET) to fluorodeoxyglucose (FDG-PET) in discriminating between Alzheimer disease (AD) and frontotemporal lobar degeneration (FTLD).

METHODS

Patients meeting clinical criteria for AD (n = 62) and FTLD (n = 45) underwent PiB and FDG-PET. PiB scans were classified as positive or negative by 2 visual raters blinded to clinical diagnosis, and using a quantitative threshold derived from controls (n = 25). FDG scans were visually rated as consistent with AD or FTLD, and quantitatively classified based on the region of lowest metabolism relative to controls.

RESULTS

PiB visual reads had a higher sensitivity for AD (89.5% average between raters) than FDG visual reads (77.5%) with similar specificity (PiB 83%, FDG 84%). When scans were classified quantitatively, PiB had higher sensitivity (89% vs 73%) while FDG had higher specificity (83% vs 98%). On receiver operating characteristic analysis, areas under the curve for PiB (0.888) and FDG (0.910) were similar. Interrater agreement was higher for PiB (κ = 0.96) than FDG (κ = 0.72), as was agreement between visual and quantitative classification (PiB κ = 0.88-0.92; FDG κ = 0.64-0.68). In patients with known histopathology, overall classification accuracy (2 visual and 1 quantitative classification per patient) was 97% for PiB (n = 12 patients) and 87% for FDG (n = 10).

CONCLUSIONS

PiB and FDG showed similar accuracy in discriminating AD and FTLD. PiB was more sensitive when interpreted qualitatively or quantitatively. FDG was more specific, but only when scans were classified quantitatively. PiB slightly outperformed FDG in patients with known histopathology.

Abstract 182: Novel hydroxamic acid-derivative, MHY218, induces apoptosis and cell cycle arrest in HCT116 human colon cancer cells

In this study, we investigated the anti-proliferative and pro-apoptotic properties of novel hydroxamic acid-derivative, MHY218, in HCT116 human colon cancer cells. We found that treatment of cells with MHY218 resulted in growth inhibition and induction of apoptosis in a concentration-dependent manner. The induction of apoptosis was showed by decreased viability, cleavage of poly(ADP-ribose) polymerase (PARP), alteration in the ratio of Bax/Bcl-2 protein expression, and activation of caspase-8 and -9 together with caspase-3. In addition, MHY218 induced G2/M phase cell cycle arrest which was related to a decrease in the protein expression of cyclin B1 and its activating partners Cdc25c and Cdc2. MHY218 also caused an increase in the expression levels of p21WAF1/CIP1 in a p53-independent pathway. Nuclear transcription factor-kappa B (NF-κB) has been reported to be an implicated factor in apoptotic cell death of various cancer cells. Therefore, we found the effect of MHY218 on NF-κB signaling pathway. Treatment of cells with MHY218 resulted in inhibition of the expression levels of NF-κB and IκBα in a dose-dependent manner. These results suggest that MHY218 may have potential as a chemotherapeutic agent for prevention against colon cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 182. doi:10.1158/1538-7445.AM2011-182

Polymorphisms in the Matrilin-1 gene and risk of mandibular prognathism in Koreans

Previous linkage analysis of an Asian population proposed possible candidate genes for mandibular prognathism, such as Matrilin-1 (cartilage matrix protein). To investigate the association between the single-nucleotide polymorphisms (SNPs) in Matrilin-1 and mandibular prognathism, we investigated three sequence variants (-158 T>C, 7987 G>A, 8572 C>T) in 164 mandibular prognathism patients and 132 control individuals with a normal occlusion. The results showed that the 8572 TT genotypes in Matrilin-1 showed increased risk of mandibular prognathism (OR = 9.28, 95% Cl = 1.19~197.57, P < 0.05), whereas the 7987 AA genotype showed a protective effect for mandibular prognathism (OR = 0.16, 95% Cl = 0.05~0.47, P < 0.05). Genotyping results showed that the Matrilin-1 polymorphism haplotype TGC (ht4; 158T, 7987G, and 8572C alleles) had a pronounced risk effect for mandibular prognathism compared with controls (OR = 5.16, 95% Cl = 2.03~13.93, P < 0.01). The results suggest that polymorphisms in Matrilin-1 could be used as a marker for genetic susceptibility to mandibular prognathism.

A nucleic acid-hydrolyzing antibody penetrates into cells via caveolae-mediated endocytosis, localizes in the cytosol and exhibits cytotoxicity

Many natural anti-DNA antibodies (Abs) have the ability to translocate across the plasma membrane and localize in the nucleus of mammalian cells, frequently leading to cytotoxicity to cells. Herein, we report detailed intracellular trafficking routes and cytotoxicity in HeLa cells for a single chain variable fragment (scFv) Ab, 3D8, which is an anti-DNA Ab capable of hydrolyzing both DNA and RNA. The intracellular penetration of 3D8 scFv occurred by caveolae/lipid raft endocytosis. The time-course chasing experiments revealed that 3D8 scFv escaped directly from the caveosome into the cytosol and remained in the cytosol without further trafficking into endosomes, lysosomes, endoplasmic reticulum, Golgi, or nucleus. The cytosolically localized 3D8 scFv maintained its nuclease activity to hydrolyze cellular RNAs, mainly mRNAs, eventually triggering apoptotic cell death. Our results demonstrate that 3D8 scFv has a unique intracellular trafficking route of localizing in the cytosol, thereby exhibiting cytotoxicity due to its nuclease activity.

Conflict monitoring in early frontotemporal dementia

BACKGROUND

Despite the extensive frontal atrophy and behavioral disinhibition that characterizes behavioral variant frontotemporal dementia (bvFTD), many studies of early bvFTD suggest normal executive functioning (EF). The current study examined cognitive control in patients with bvFTD who otherwise seemed cognitively normal.

METHODS

Subjects included 7 patients with bvFTD with normal neuropsychological test scores, 7 patients with bvFTD matched for Mini-Mental State Examination score but with impaired neuropsychological test scores, and 14 normal controls. A flanker paradigm and other measures of EF were administered to participants. A semiautomated parcellation program was used to analyze structural MRI scans.

RESULTS

On the flanker task, multivariate analysis of variance revealed a significant condition X diagnosis interaction. Both bvFTD groups showed a larger congruency effect than normal controls, i.e., they displayed disproportionately reduced speed and accuracy on incongruent trials relative to congruent trials. Imaging data illustrated significant orbitofrontal atrophy in patients with early bvFTD as compared with controls.

CONCLUSIONS

Patients with behavioral variant frontotemporal dementia (bvFTD) who performed within normal limits on clinical tests of executive functioning demonstrated a select impairment on an experimental test of cognitive control, suggesting a subtle impairment in inhibiting attention or response to the irrelevant stimuli. Measures of neuropsychological functioning sensitive to the ventromedial prefrontal cortex may be useful in early diagnosis of patients with bvFTD. Our understanding of this syndrome may be increased by considering the efficiency of selective inhibition, a fundamental component of executive cognitive control.

Modulation of firing activity by ATP in dopamine neurons of the rat substantia nigra pars compacta

ATP acts as a neurotransmitter or co-neurotransmitter in many areas of the CNS and peripheral nervous systems; however, little is known about the expression and functional role of purinoceptors (P2) in midbrain dopaminergic neurons. Therefore, we investigated P2X receptor expression and regulation of spontaneous firing activity in dopaminergic neurons of the substantia nigra pars compacta (SNc) in rats using patch-clamp and Ca(2+)-imaging techniques. In most neurons, application of ATP (1 microM-1 mM) increased firing rate dose-dependently (EC(50)=1.26+/-0.26 microM, n=45). When the P2-receptor agonists such as 2-methylthio-adenosine 5'-triphosphate (2-MeSATP) or ATPgammaS were applied or pressure-applied to the neuron, the firing activity increased together with a rise in cytosolic Ca(2+) concentration ([Ca(2+)]c), but application of beta,gamma-methylene ATP (P2X(1, 3) agonist) or methylthio-adenosine 5'-diphosphate (P2Y(1) agonist) had no effect. In many neurons, the effect of ATP was abolished by the application of the P2-receptor antagonists, suramin or pyridoxal-phosphate-6-azophenyl-2',4'-disulfonic acid (PPADS). When ATP was applied in a Ca(2+)-free solution, there was no detectable change in [Ca(2+)]c, suggesting that ATP does not release Ca(2+) from intracellular stores. In the single-cell reverse transcription polymerase chain reaction (RT-PCR), we found that 65% of dopaminergic neurons expressed mRNAs for P2X receptors; positive amplifications of P2X(6) (57.1%), P2X(2/6) (25.0%), and P2X(4) mRNA (17.9%), respectively. From the above results, we could conclude that ATP modulates firing activities in the rat SNc dopaminergic neurons, possibly via P2X(2), P2X(2/6), and/or P2X(4) receptors.

Expression profiling of radiation-induced genes in radiodermatitis of hairless mice

BACKGROUND

Radiation induces many cellular events leading to radiodermatitis.

OBJECTIVES

The aim of this study was to establish a radiodermatitis model using experimental animals, and to examine the expression profile of radiation-induced genes.

METHODS

Hairless mice were irradiated on the dorsal skin; then total RNAs were isolated and microarray hybridizations were performed.

RESULTS

Irradiation with a total of 40 Gy (10 Gy day-1 for four consecutive days) provokes radiodermatitis in the hairless mouse. After microarray analysis, 130 genes that showed upregulation by radiation were selected and organized into four different clusters, depending on the time-kinetic pattern. Classification of these genes into several functional categories revealed that various biological processes were globally affected by radiation. These include transcription regulation, signal transduction, cell communication, cell death regulation and metabolism.

CONCLUSIONS

These results demonstrate the complexity of the transcriptional profile of the radiation response, providing important clues on which to base further investigations of the molecular events underlying radiodermatitis.

Effects of Puerariae Flos and Puerariae Radix extracts on antioxidant enzymes in ethanol-treated rats

This study was performed to investigate the effect of Puerariae Flos (PF) and Puerariae Radix (PR) water extracts on the activities and mRNA expression of three hepatic antioxidant enzymes in ethanol-treated rats. Male Sprague-Dawley rats were divided into four groups, a control, ethanol-treated, ethanol plus PF-treated, and ethanol plus PR-treated group with seven rats per group. Ethanol (25 % v/v, 5 g/kg body weight) was orally administered once a day for 5 weeks. The PF and PR water extracts were supplemented in a diet based on 1.2 g of raw PF or PR/kg body weight/day. Ethanol administration without the PF or PR supplement significantly lowered the activities of hepatic Cu/Zn SOD and catalase (CAT), whereas it increased the hepatic GSH-Px activity. However, the PF and PR supplementation resulted in a significant increase in the Cu/Zn SOD and/or CAT activities and a significant decrease in the GSH-Px activity in the ethanol-treated rats. The mRNA levels of these antioxidant enzymes in the ethanol-treated rats were normalized to the control level by the PF or PR supplement. The hepatic glutathione content, which was significantly lower in the ethanol-treated group than in the control group, was also normalized to the control level by supplementing with either PF or PR. The PF or PR supplement resulted in lowering the hepatic malondialdehyde to the control level in the ethanol-treated rats.

Endogenous gastrin stimulates regeneration of remnant pancreas after partial pancreatectomy

The purpose of this study was to evaluate the effect of endogenous gastrin on pancreatic regeneration after a partial pancreatectomy in the rat. Sixty rats were divided into 6 groups. Groups I and II received sham operation (splenectomy only), and groups III, IV, V, and VI received both 66% partial pancreatectomy (PPx) and splenectomy. Endogenous hypergastrinemia was induced in groups II, IV, and VI by gavage of Lansoprozole (LSP) for three weeks. In groups V and VI, gastrin receptor blocker, L365,260, was given continuously using an osmotic minipump. Following three weeks of treatment, PPx alone increased the pancreatic weight and protein content, but not RNA or DNA content (Group III). In the PPx groups, the pancreatic weight, and contents of protein, RNA, and DNA were significantly increased in the LSP treated rats (Group IV). This effect was abolished by L365,260 (Group VI). This results suggest that endogenous gastrin specifically stimulates regeneration of the remnant pancreas after partial pancreatectomy in rat. Induction of endogenous hypergastrinemia may be useful in patients following pancreatic resection for the prevention and treatment of pancreatic insufficiency.

Circulating levels of interleukin-8 and vascular endothelial growth factor in patients with carotid stenosis

Interleukin (IL)-8 and vascular endothelial growth factor (VEGF) are important factors that induce the migration and proliferation of endothelial cells, increase the vascular permeability, and the modulate chemotaxis of monocytes. These molecules have been found in human atherosclerotic plaques. However, it is not clear whether the circulating levels of IL-8 and VEGF correlate with the extents of carotid stenosis. In this study, we investigated the relationship between circulating levels of IL-8 as well as VEGF and the extents of carotid stenosis. Sera from 41 patients with carotid stenosis were assessed for concentrations of IL-8 and VEGF by enzyme-linked immunosorbent assay. The degree of stenosis of extracranial carotid artery was calibrated by carotid B- mode ultrasonography. The serum concentration of IL-8 (r = -0.04733, p > 0.05) was not correlated with the degree of stenosis. However, the serum concentration of VEGF (r = 0.4974, p < 0.01) was significantly correlated with the degree of carotid stenosis. These findings suggest that increased serum level of VEGF might be a marker for higher degree of stenosis of extracranial carotid artery.

Practical guidelines for the preservation of the pancreaticoduodenal arteries during duodenum-preserving resection of the head of the pancreas: clinical experience and a study using resected specimens from pancreaticoduodenectomy

BACKGROUND/AIMS

The purpose of this study was to create a practical guideline for vascular preservation during duodenum-preserving resection of the head of the pancreas.

METHODOLOGY

We examined the anatomy of pancreaticoduodenal arteries by specimen angiography and dissection using 12 pancreaticoduodenectomy specimens. We also reviewed our experiences with duodenum-preserving resection of the head of the pancreas.

RESULTS

In the specimens, the posterior pancreaticoduodenal artery and its duodenal branches were easily separated from the posterior surface of the pancreas, and its papillary branch was identified in two-thirds of the cases. It was difficult to dissect the anterior superior pancreaticoduodenal arteries from the pancreas because they were partially buried in the pancreatic parenchyma. The anterior inferior pancreaticoduodenal artery located in the posterior and inferior surface of the pancreas could be safely dissected in two-thirds of the cases. Duodenum-preserving resection of the head of the pancreas was performed in 7 patients. In every case, the anterior superior pancreaticoduodenal artery was sacrificed and the anterior inferior pancreaticoduodenal artery was preserved. In 3 cases, the entire posterior pancreaticoduodenal artery was preserved and in 4 cases a short segment of the posterior pancreaticoduodenal artery was removed accidentally. The pancreatic head was totally removed and the intrapancreatic common bile duct was preserved. There were 3 postoperative complications, pancreatic leakage, intraabdominal fluid collection and bile duct stricture. They improved with conservative management.

CONCLUSIONS

To safely perform duodenum-preserving resection of the head of the pancreas, preservation of the whole posterior pancreaticoduodenal artery and anterior inferior pancreaticoduodenal artery is recommended because they can be safely dissected from the pancreas, and the posterior pancreaticoduodenal artery provides the major blood supply to the papilla and distal bile duct. However, removal of a short segment of posterior pancreaticoduodenal artery does not preclude a good blood supply to the duodenum because of bidirectional blood flow.

Biological monitoring of workers exposed to ethylbenzene and co-exposed to xylene

OBJECTIVE

Ethylbenzene is an important constituent of widely used solvent mixtures in industry. The objective of the present study was to provide information about biological monitoring of occupational exposure to ethylbenzene, and to review the biological limit values corresponding to the threshold limit value of ethylbenzene.

METHODS

A total of 20 male workers who had been exposed to a mixture of ethylbenzene and xylene, through painting and solvent mixing with commercial xylene in a metal industry, were recruited into this study. Environmental and biological monitoring were performed during an entire week. The urinary metabolites monitored were mandelic acid for ethylbenzene and methylhippuric acid for xylene. Correlations were analyzed between urinary metabolites and environmental exposure for ethylbenzene and xylene. The interaction effects of a binary exposure to ethylbenzene and xylene were also investigated using a physiologically based pharmacokinetic (PBPK) model.

RESULTS

The average environmental concentration of organic solvents was 12.77 ppm for xylene, and 3.42 ppm for ethylbenzene. A significant correlation (R2 = 0.503) was found between environmental xylene and urinary methylhippuric acid. Urinary level of methylhippuric acid corresponding to 100 ppm of xylene was 1.96 g/g creatinine in the worker study, whereas it was calculated as 1.55 g/g creatinine by the PBPK model. Urinary level of mandelic acid corresponding to 100 ppm of ethylbenzene was found to be 0.7 g/g creatinine. PBPK results showed that the metabolism of ethylbenzene was highly depressed by co-exposure to high concentrations of xylene leading to a non-linear behavior.

CONCLUSIONS

At low exposures, both methylhippuric acid and mandelic acid can be used as indicators of commercial xylene exposures. However at higher concentrations mandelic acid cannot be recommended as a biological indicator due to the saturation of mandelic acid produced by the co-exposure to xylene.

K-ras oncogene mutation in cancer and precancerous lesions of the gallbladder

BACKGROUND AND OBJECTIVES

To determine whether K-ras mutation plays any role in the development and progression of gallbladder cancer, or has any clinical or pathological significance in gallbladder cancer patients, we investigated the presence and incidence of this mutation in the normal mucosa, and precancerous and cancerous lesions of the gallbladder.

METHODS

DNA was obtained from normal mucosa, dysplastic mucosa, primary cancer tissues, and metastatic lymph nodes that were identified and microdissected from the paraffin blocks of 20 gallbladder cancer cases. K-ras codon 12 mutations were investigated using a modified two-step polymerase chain reaction and the restriction fragment length polymorphism method, and by direct sequencing with an automated sequencer.

RESULTS

K-ras mutations were detected in the tissues of 10 out of the 20 patients. A mutation was present in the dysplastic epithelium associated with the primary carcinoma in 3 out of 12 specimens, in metastatic carcinoma in 1 out of 5 patients, and in primary carcinoma in 8 out of 20 patients. Mutation was found only once in the dysplastic, noncancerous epithelium, and only once in a metastatic tumor although not detectable in the primary cancer. Direct sequencing showed that the mutations were G to C substitutions (GGT-->CGT) at the first site of codon 12, except in two cases (GGT-->TGT). There were no correlations between K-ras mutations and clinicopathological factors.

CONCLUSIONS

K-ras mutations were detected in half of the gallbladder cancer cases. We suggest that K-ras mutation may play a role in the development of premalignant lesions or early carcinogenesis in some gallbladder cancers. We were unable to find any evidence that K-ras mutation plays any role in tumor progression or metastasis, or that it has any clinicopathological significance.

Acoustic rhinometric evaluation of the nasal response to exercise in patients with nasal septal deviation

We aimed to investigate nasal response to exercise in patients with a nasal septal deviation. Acoustic rhinometric measurements of cross-sectional areas (CSA) at 3.3, 4.0, 6.4 cm from the nostril, and nasal volume (NV) were conducted in 10 patients. The consecutive measurements were undertaken just before and immediately after 10, 20, and 30 min of treadmill exercise. In the concave nasal cavities, NV and CSA at 3.3 cm and 6.4 cm from the nostril showed a significant increase in immediate post-exercise and 10-minute post-exercise measurements. At 4.0 cm from the nostril, a significant increase was sustained by 20 min after exercise. However, in convex nasal cavities, exercise did not result in a significant increase except for the immediate post-exercise measurement at 4 cm from the nostril. The results of this study indicated that, in nasal septal deviation, the mucosal response is more prominent in the concave nasal cavities than in the convex nasal cavities.

Uncertainties in physiologically based pharmacokinetic models caused by several input parameters

OBJECTIVE

One of the problems in the application of physiologically based pharmacokinetic (PB-PK) models is that authors often use different input parameters, with unknown influence on the results. Differences in the simulation results obtained with various sets of parameters are examined herein.

METHOD

Chemicals considered were perchloroethylene, toluene, and styrene. Simulations of alveolar concentrations, blood concentrations, and urinary metabolite excretions were performed for the three solvents. The input parameters discussed herein are physiological values, metabolic constants, and partition coefficients. The influence of metabolic constants and partition coefficients is studied by comparison of models against one another.

RESULTS

Metabolic parameters such as Vmax and K(m) varied considerably between authors. Tissue-gas partition coefficients, especially for the fat compartment, also differed according to the authors. Such differences in input parameter values proved to have a large influence on PB-PK model results and, therefore, increased their uncertainties. Uncertainties were much more significant in urinary metabolite concentration than in alveolar and blood concentration for chemicals that are poorly metabolized. On the other hand, uncertainties were more significant in alveolar and blood concentrations than in urinary metabolite excretions for chemicals that are well metabolized.

CONCLUSION

Careful attention is necessary in the selection and/or citation of values from published data. The validity of PB-PK models should be simultaneously confirmed with both the blood and/or alveolar concentration and urinary metabolite concentrations.

Border malaria characters of reemerging vivax malaria in the Republic of Korea

Since 1993, the number of vivax malaria cases has increased every year in the northern part of the Republic of Korea (ROK). This study was designed to characterize factors related to the reemergence of malaria in the ROK. A total of 21 cases diagnosed in 1993 and 1994 distributed sporadically in the narrow zone along the demilitarized zone (DMZ). Of total 317 civilian inhabitant cases reported in 1994-1997, 287 cases were studied and 80.8% of them resided within 10 km from the southern border of the DMZ. The frequency distribution of anti-Plasmodium vivax antibody titers using indirect fluorescent antibody test was compared in three villages in relation with distance from the DMZ. The number of inhabitants with high antibody titers was larger in the village nearest to the border than that in more distant villages. The present results highly suggested that the reemerging vivax malaria start in the border area, most possibly caused by infected mosquitoes which flew across the border. This pattern of transmission repeated year after year.

Up-regulation of interleukin-4 and CD23/FcepsilonRII in minimal change nephrotic syndrome

Although the pathogenesis of childhood minimal change nephrotic syndrome (MCNS) has not been clearly defined, the current hypothesis favors an involvement of T cell dysfunction. The symptom onset and the relapse of MCNS are frequently associated with allergy and increased IgE levels in sera. Since a T cell-derived cytokine interleukin-4 (IL-4) plays a key role in the regulation of IgE production and allergic response, we investigated the role of IL-4 in the pathophysiology of MCNS. Using fluorescence-activated cell scanning we observed a significantly higher expression of CD23, the type II IgE receptor (FcepsilonRII), on fresh B cells from active MCNS patients (n=22) compared with age-matched healthy normal controls (n=12). The upregulation of CD23 correlates with greater IL-4 activity in the culture supernatant of MCNS peripheral blood lymphocytes (PBLs) than normal PBLs stimulated by mitogens, as assessed by the CD23-inducing effect of the PBL supernatant on tonsillar B cells. Furthermore, Northern blot and reverse transcription-based polymerase chain reaction analysis have revealed significantly elevated levels of IL-4 mRNAs both in mitogen-stimulated and unstimulated MCNS PBLs, compared with healthy normals or disease controls with other renal disorders. Together these results strongly suggest that the upregulation of IL-4 in T cells may be part of the T cell dysfunction involved in MCNS.

Application of biological monitoring to the quantitative exposure assessment for neuropsychological effect by chronic exposure to organic solvents

OBJECTIVE

Quantitative exposure assessment became more common as a result of attempts to reduce nondifferential exposure misclassification and to observe a steeper exposure-response relationship. Several exposure variables were compared in a demonstration of the exposure-response relationship between neuropsychological abnormality and long-term exposure to organic solvents in workers at one shipyard.

METHOD

Environmental monitoring and biological monitoring were performed to evaluate the exposure of the workers to organic solvents. Cumulative exposure (CE) and lifetime-weighted average exposure variables were developed with both environmental and biological monitoring data. A neuropsychological questionnaire and a function test for confirmation of a disorder or dysfunction in attention, executive function, visuospatial, and constructional abilities, learning and memory, and psychomotor function were performed.

RESULTS

The abnormal rate in neuropsychological diagnosis was 9.3% in the exposed group, which was much higher than the 2.1% rate obtained in the nonexposed group (P<0.01). The neuropsychological abnormal rate showed a significant dose-response association with CE created with biological monitoring data. The results also suggest that biological monitoring can provide impressive and effective information for quantitative exposure assessment, even in epidemiology studies.

Biological monitoring of tetrahydrofuran: contribution of a physiologically based pharmacokinetic model

A seven-compartment physiologically based pharmacokinetic (PBPK) model was developed to predict biological levels of tetrahydrofuran under various exposure scenarios. Affinities for the tissue were estimated from measurements of liquid-gas partition coefficients for water, olive oil, and blood. Metabolism was assumed to follow a rapid first order reaction. urinary excretion was simulated considering passive reabsorption of tetrahydrofuran in the tubules. The validity of the model was tested by comparison with available experimental and field data. Agreement was satisfactory with all studies available except one, which showed much higher results than expected. The source of this difference could not be identified, but cannot be explained by different exposure conditions, such as duration, concentration, or physical work load. However, it is recommended that this particular study not be used in the establishment of a biological exposure index. Simulation of repeated occupational exposure with the PBPK model allowed the prediction of biological levels that would be reached after repeated exposure at the American Conference of Governmental Industrial Hygienists' threshold limit value, time-weighted average of 200 ppm. For samples taken at the end of the shift, the PBPK model predicts 5.1 ppm for breath, 57 mumol/L (4.1 mg/L) for venous blood, and 100 mumol/L (7.2 mg/L) for urine.

Comparison of the hemolytic activity and solution structures of two snake venom cardiotoxin analogues which only differ in their N-terminal amino acid

Cardiotoxin analogues IV (CTX IV) and II (CTX II) isolated from the venom of Taiwan Cobra (Naja naja atra) differ in their amino acid sequence by a single amino acid at the N-terminal end. Leucine at the N-terminal end in CTX II is replaced by arginine in CTX IV. CTX IV is an unique snake venom cardiotoxin as it is the only cardiotoxin isoform known so far which possesses a positively charged residue at the N-terminal amino acid. All other cardiotoxins have a hydrophobic amino acid (leucine or isoleucine) at their N-terminal end. The aim of the present study is to understand the effect(s) of the presence of a cationic residue on the structure and functional properties of cardiotoxin(s). Comparison of the hemolytic activities of CTX IV and CTX II shows that lytic activity of the former is at least twice as that shown by the latter. Comparison of the solution structures of CTX IV and CTX II using two-dimensional NMR spectroscopy and dynamical simulated annealing technique reveals that the backbone fold of both the toxin isoforms is almost similar. The secondary structural elements in these two cardiotoxin isoforms consist of long, triple-stranded, as well as short, double-stranded, antiparallel beta-sheets. Thermal denaturation experiments showed that the structure of CTX IV is more stable than that of CTX II. Critical analysis of the three-dimensional structures of CTX IV and CTX II reveals the presence of a "cationic" cluster comprising of positively charged residues on the concave side of the CTX IV molecule. Similar clusters consisting of positively charged residues are not found in CTX II. The differential erythrocyte lytic activities of these two cardiotoxins are attributed to the difference(s) in the distribution of the positively charged residues in their three-dimensional structures.