Application of Western patients-based Adjuvant! Online (AOL) model on Korean colon cancer patients

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Background: Adjuvant! Online (AOL) is a web-accessible risk-assessment model that predicts the mortality and the benefits of adjuvant therapy ( www.adjuvantonline.org ). AOL has never been validated for Asian colon cancer patients.

Methods: Using the Yonsei Tumor Registry (YTR) database, we calculated the survival for the patients with T1-4, N0-2, M0 colon cancer who were treated at the Yonsei Cancer Center between 1990 and 2005. Observed and predicted 5-year survival was compared for each patient.

Results: The median age of the study population was 60 years (range, 15-87 years) and the median follow-up duration was 7.9 years (range, 0.06-19.8 years) for all 1,431 patients. While AOL underestimate overall survival (OS) (predicted-observed=-1.02%, P=0.008), it overestimate colon cancer-specific survival (CCSS) (predicted-observed=3.8%, P<0.001) in Korean patients. Especially, AOL underestimated OS and CCSS in younger patients than age 50 years (predicted-observed=-4.3%, P<0.001 and predicted-observed=-3.5%, P<0.001, respectively). We conducted an internal model validation by using a Korean version of AOL (KAOL), which was a new model for prognosis based on AOL's parameters. 5-year OS and CCSS between the observed and the KAOL predicted survival were not different (77.25 vs. 77.15, P=0.873 and 77.4% vs. 77.6%, P=0.78, respectively). The concordance indexes about OS and CCSS were 0.75 and 0.74, respectively.

Conclusions: KAOL model for Korean colon cancer patients is more suitable to predict 5-year outcomes compared to ALO model for Western patients.

No significant financial relationships to disclose.

Clevudine for chronic hepatitis B: antiviral response, predictors of response, and development of myopathy

Clevudine has been approved for the treatment of chronic hepatitis B (CHB) in South Korea. However, its long-term antiviral effect and safety awaits more study. The aim of this study was to evaluate antiviral efficacy, predictors of virologic response, and development of myopathy after clevudine therapy for CHB. The study included 102 nucleoside naïve CHB patients who had received clevudine for more than 6 months with good compliance. The median duration of clevudine treatment was 53 weeks (range, 25-90 weeks). A retrospective analysis of data retrieved from medical records was performed. The cumulative rate of virologic response [hepatitis B virus (HBV) DNA level <2000 copies/mL] at 48 weeks of clevudine therapy was 81%, and cumulative rate of clevudine resistance was 11% at 60 weeks of treatment. Independent predictors of virologic response to clevudine therapy were hepatitis B e antigen (HBeAg) negativity and rapid decrease of viral load during the early phase of treatment. The clevudine-related myopathy developed in 3.9% of patients, and was reversible after discontinuation of clevudine. Clevudine showed a potent antiviral response, and its effect was higher in HBeAg-negative patients, with rapid viral load reduction after therapy. However, long-term therapy for more than 1 year resulted in the development of considerable resistance and myopathy. Therefore, we should consider alternative antiviral agents if clevudine resistance or clevudine-induced myopathy is developed in patients on clevudine for the treatment of CHB.

67 PIG OOCYTES WITH A LARGE PERIVITELLINE SPACE MATURED IN VITRO HAVE GREATER DEVELOPMENTAL COMPETENCE AFTER PARTHENOGENESIS AND SOMATIC CELL NUCLEAR TRANSFER

The size of perivitelline space (PVS) is closely related with the frequency of polyspermic fertilization in pig oocytes. It has been reported that enlargement of PVS is attributed to accumulation of glycoproteins synthesised and secreted from cumulus cells and that culture of immature oocytes in low-salt medium enlarges PVS in pigs. This study examined the developmental competence of pig oocytes after parthenogenetic activation (PA) and somatic cell nuclear transfer (SCNT) in relation to the size of the PVS of oocytes matured in vitro (IVM). Cumulus–oocyte complexes were matured in medium 199 (Experiment 1) or porcine zygote medium (PZM)-3 (Experiment 2) supplemented with pig follicular fluid, cysteine, pyruvate, EGF, insulin, and hormones for the first 22 h and then cultured in hormone-free medium for an additional 22 h. IVM oocytes were activated electrically for PA or used as recipient cytoplasts for SCNT. PA and SCNT embryos were cultured for 7 days in PZM-3 medium supplemented with bovine serum albumin. The intracellular glutathione (GSH) level in IVM oocytes was determined by analysing the fluorescence intensity of oocytes after staining with CellTracker Blue CMF2HC. The expression of CDK1, PCNA, and ERK2 mRNA in IVM oocytes was analysed by RT-PCR. Data were analysed using a general linear model procedure followed by the least significant difference mean separation procedure when the treatments differed at P < 0.05. In Experiment 1, oocytes with a larger PVS had higher (P < 0.05) levels of intracellular GSH (1.0 pixels/oocyte v. 0.6 pixels/oocyte) and blastocyst formation (54% v. 37%) after PA than oocytes with smaller PVS. In Experiment 2, maturation culture of oocytes in PZM-3 with reduced (61.6 mM) NaCl concentration significantly increased (P < 0.05) the size of the PVS (5.2 μM v. 3.3 μM) compared with control oocytes that were matured in PZM-3 containing 108 mM NaCl, although the treatment did not alter the nuclear maturation. Moreover, oocytes with increased PVS expressed more CDK1, PCNA, and ERK2 mRNA and had higher (P < 0.05) intracellular GSH levels (1.6 pixels/oocyte v. 1.2 pixels/oocyte) and increased blastocyst formation after PA (52% v. 41%) and SCNT (32% v. 18%) compared with control oocytes. Our results demonstrate that pig oocytes with a large PVS have greater developmental competence after PA and SCNT, which is attributed to improved cytoplasmic maturation resulting from the enhanced GSH level and transcription factor expression and that enlargement of PVS by the culture in low-NaCl medium also improves developmental competence of pig oocytes. This work was supported by grants (#20070301034040 and #20080401034072) from the BioGreen 21 Program (Rural Development Administration, Republic of Korea).

Formation of vitamin A lipid droplets in pancreatic stellate cells requires albumin

OBJECTIVE

Quiescent pancreatic stellate cells (PSCs) store vitamin A as cytoplasmic lipid droplets, and, when activated by profibrogenic stimuli, they transform into myofibroblast-like cells characterised by the loss of vitamin A droplets. Activation of stellate cells is central to fibrogenesis, but the mechanism for the formation of vitamin A droplets and its relationship to stellate cell activation remain unclear.

METHODS

With use of cultured PSCs, an attempt was made to characterise the function of albumin endogenously expressed in stellate cells.

RESULTS

Albumin is endogenously expressed in quiescent PSCs, localised in cytoplasmic lipid droplets, and its levels are markedly reduced after stellate cell activation. Continuous albumin expression in stellate cells is sufficient to maintain their fat-storing phenotype even after cell passages and renders cells resistant to the activating effects of transforming growth factor beta (TGFbeta). Forced expression of albumin in PSCs after passage 2 (activated PSCs) induced the re-appearance of lipid droplets and phenotypic changes, which were previously reported with retinol treatment. Retinol increases albumin synthesis in activated PSCs and the suppression of albumin expression using small interfering RNA (siRNA) abolishes retinol-induced effects.

CONCLUSIONS

The data demonstrate a novel role for albumin in the formation of cytoplasmic vitamin A lipid droplets in stellate cells, and suggest that albumin may have a direct influence on stellate cell activation.

Improvement in skin wrinkles from the use of photostable retinyl retinoate: a randomized controlled trial

BACKGROUND

Photoaged skin can be treated with retinoids, which are natural and synthetic vitamin A derivatives. However, these are photounstable and can cause skin irritation, which is a major limitation in their use in general cosmetics. Retinyl retinoate, which is an ester of all-trans retinoic acid (RA) and all-trans retinol, has reduced toxicity due to blocking of the carboxyl end group of RA and higher skin regeneration activity than retinol.

OBJECTIVES

To assess the efficacy of a photostable retinyl retinoate in treating women over 30 years old with periorbital wrinkles.

METHODS

We conducted two clinical studies with a total of 46 Korean women with periorbital wrinkles, who were not pregnant, nursing or undergoing any concurrent therapy. In the first clinical study, the efficacy of retinyl retinoate was compared with placebo. Twenty-four patients completed a 12-week trial of 0.06% retinyl retinoate applied twice daily to one side of the face and a placebo applied to the other side. In the second clinical study, the efficacy of retinyl retinoate was compared with retinol. Twenty-two patients completed an 8-week trial of 0.06% retinyl retinoate applied twice daily to one side of the face and 0.075% retinol applied to the other side. Efficacy was based on a global photodamage score, photographs, and image analysis using replicas and visiometer analysis (Skin-Visiometer SV 600; Courage & Khazaka, Cologne, Germany) every 4 weeks. The standard wrinkle and roughness parameters used in assessing skin by visiometer were calculated and statistically analysed.

RESULTS

The retinyl retinoate-treated wrinkles improved compared with wrinkles treated with placebo or retinol, as assessed by both the investigators and the subjects. Also, skin replica analysis indicated significant improvements in retinyl retinoate-treated skin in both studies, especially in average roughness.

CONCLUSIONS

Retinyl retinoate applied twice daily was significantly more effective than a placebo or retinol in treating periorbital wrinkles. Importantly, no severe side-effects were observed.

Comparison of risk factors and clinical responses to proton pump inhibitors in patients with erosive oesophagitis and non-erosive reflux disease

BACKGROUND

There has been no report on the response to proton pump inhibitor (PPI) therapy and on-demand or the relapse rate of non-erosive reflux disease (NERD) and erosive oesophagitis in Korea.

AIM

To compare the risk factors, clinical symptoms and PPI responses between patients with erosive oesophagitis and NERD patients.

METHODS

A survey was performed prospectively in the erosive oesophagitis (205 patients) and NERD group (200 patients). Clinical symptoms, risk factors and PPI responses were analysed. On-demand therapy and the relapse rate of GERD symptoms were investigated during a one-year follow-up.

RESULTS

BMI > or = 25 (OR 3.0, 95% CI 1.1-8.3), alcohol use (OR 2.9, 95% CI 1.0-8.3), hiatal hernia (OR 5.0, 95% CI 1.2-20) and triglyceride > or =150 mg/dL (OR 4.0, 95% CI 1.7-10) were more common in the erosive oesophagitis group than in the NERD group by multivariate analysis. The ratio of oesophageal to extra-oesophageal symptoms was higher in the erosive oesophagitis group compared with the NERD group (P < 0.001). The PPI response rates at 8 weeks were different (P = 0.02); refractory rates were higher in the NERD group (16.7%) compared with the erosive oesophagitis group (6.0%). However, there was no significant difference between the two groups in on-demand therapy or the relapse rate.

CONCLUSION

These results suggest that the underlying pathogenic mechanisms of erosive oesophagitis and NERD are distinct.

Prognostic impact of response to second-line chemotherapy on overall survival of patients with advanced gastric cancer

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Background: It has been debated on whether tumor response to first-line chemotherapy (CT) would be reliable predictor for overall survival (OS) of cancer patients (pts). In case of advanced gastric cancer (AGC), many pts receive 2nd line CT after failure to 1st line treatment, so response to 2nd line CT as well as 1st line could affect OS. Methods: We retrieved clinical data of a total of 1,335 pts with AGC treated with palliative CT from January 2000 to December 2006 in National Cancer Center, Korea, including 757 pts who also received 2nd line CT. Responses to 1st and 2nd line CT were evaluable in 504 pts. Retrospective analysis was done to find correlation between objective tumor response to 1st and 2nd line CT and OS of the 504 pts, whom we divided into 4 groups: responders to both 1st and 2nd line CT (RR group); responders to 1st but not to 2nd line CT (RN group); responders to 2nd but not to 1st line CT (NR group); and nonresponders to both 1st and 2nd line CT (NN group). Results: Objective response rate of 1st and 2nd line CT was 41.7% and 12.3%, respectively. Responders to 1st line CT had a trend to respond to 2nd line CT (ORR of 2nd line CT in responders vs nonresponders to 1st line CT: 15.7% vs 9.9%, p = 0.049). 33/177/29/265 pts were assigned to each of RR/RN/NR/NN group, respectively. With median follow-up of 48.7 mo (range 23.2 - 93.7), median OS was 12.7 mo (95% CI 11.8–13.6). Baseline characteristics were balanced between 4 groups except higher hemoglobin and serum albumin level in RR group, younger median age in NN group, and fewer pts with poor performance status or poorly differentiated histology in NR group. Overall survival of RR, RN, NR, and NN group was 31.8 mo, 15.5 mo, 18.9 mo, and 9.2 mo, respectively (p<0.001). Multivariate analysis revealed relapsed disease after curative surgery, well-differentiated histology, absence of pulmonary metastasis, higher serum albumin level, lower serum bilirubin and alkaline phosphatase level, response to both of 1st line and 2nd line CT were reliable factors for favorable survival. Conclusions: Among the patients who received 2nd line chemotherapy for AGC, response to 2nd line CT was strongly associated with OS regardless of previous response to 1st line CT.

No significant financial relationships to disclose.

304 PRODUCTION OF TRANSGENIC CHICKENS EXPRESSING HUMAN ERYTHROPOIETIN IN A TETRACYCLINE-INDUCIBLE MANNER

The use of livestock animals as bioreactors to address the growing demand for large quantities and increasing numbers of biopharmaceuticals is of prime strategic relevance to agricultural improvement and medical advancement. We report here the production of transgenic chickens that produce human erythropoietin (hEPO) using replication-defective Moloney murine leukemia virus-based vectors. Because it is well known that constitutive overexpression of some cytokine genes in the transgenic animals may cause serious physiological disturbances, the vectors were designed to express in the presence of tetracycline. In addition, we introduced woodchuck hepatitis virus posttranscriptional regulatory element sequence at 3′ end of hEPO gene to boost the gene expression under the inducible condition. Approximately 5 μL of vector virus solution concentrated as much as 109 cfu mL–1 was injected beneath the blastoderm of non-incubated chicken embryo (stage X). Out of 596 injected eggs, 36 chicks hatched after 21 days of incubation and 23 hatched chicks were found to express vector-encoded hG-GSF gene when fed with doxycycline. Quantitative analysis of the blood samples taken from some Go transgenic chickens resulted in more than 300 IU mL–1 of hEPO in the blood. These transgenic chickens have not exhibited any physiological abnormalities; therefore, it is possible that this controllable gene expression system may be useful in minimizing detrimental side effects when used to produce other transgenic animals. The biological activity of the recombinant hEPO was comparable to its commercially derived Escherichia coli counterpart. The significance of this work stems from the fact that it is the first successful report on the production of transgenic chickens expressing the hEPO gene. This approach can be employed to create a useful transgenic model system for further studies on the chicken embryo development and the efficient production of transgenic chickens as bioreactors. This work was supported by: The BioGreen 21 Program of the Rural Development Administration, Republic of Korea; The SRC/ERC program of MOST/KOSEF (grant no. R11-2002-100-04005-0); The 2006–2011 Technology Development Program for Agriculture and Forestry (TDPAF), Ministry of Agriculture and Forestry, Republic of Korea.

Use of whey permeate for cultivating Ganoderma lucidum mycelia

A novel approach to utilizing whey permeate, the cultivation of mycelia of the edible mushroom Ganoderma lucidum, is introduced. The major objective of this research was to use whey permeate as an alternative growth medium for the cultivation of mycelia of edible mushroom G. lucidum and to find an optimum condition for solid-state cultivation. Response surface analysis was applied to determine the combination of substrate concentration (25 to 45 g of lactose/L), pH (3.5 to 5.5), and temperature (25 to 35 degrees C) resulting in a maximal mycelial growth. The radial extension rates, estimated by measuring the diameters of growing colonies on the Petri dishes, were used as the growth of the mycelia at different conditions. In the model, pH and temperature significantly affected mycelial growth, but lactose concentration did not. The condition predicted to maximize the radial extension rate of 17.6 +/- 0.4 mm/d was determined to be pH 4.4 and temperature 29.4 degrees C. Therefore, the results suggest that whey permeate could be utilized as a growth substrate for the cultivation of mycelia from the edible mushroom G. lucidum, enhancing the use of this by-product by the cheese manufacturing industry.

Does microbleed predict haemorrhagic transformation after acute atherothrombotic or cardioembolic stroke?

OBJECTIVES

Cerebral microbleeds (MBs) are known to be indicative of bleeding-prone microangiopathy and may predict incident intracerebral haemorrhage. However, there is controversy concerning the causal relationship between the presence of MBs and haemorrhagic transformation (HTf) after ischaemic stroke.

METHODS

Of the 1034 patients with acute ischaemic stroke who were consecutively admitted to our hospital, 377 patients with stroke due to large-artery atherothrombosis or cardioembolism were selected for participation in this study. We examined the MBs using T2*-weighted gradient-echo MRI performed within 24 hours after admission, and the incidence of HTf was assessed using follow-up brain MRI during the hospitalisation period.

RESULTS

Of the 377 patients with stroke, 234 were male (62.1%) and the mean age was 66.2 +/-11.7 years. MBs were initially found in 109 patients (28.9%), and newly incident HTf was noted during the hospitalisation period in 74 patients (19.6%). The presence of MBs was not increased in the patients with HTf (24.3% vs. 30.0% in the patients without HTf; p = 0.331). In addition, the number of MBs was not higher in the patients with HTf (0.7+/-1.5 vs. 1.8+/-8.1; p = 0.234). This lack of significance between MBs and HTf persisted after stratification by stroke mechanism.

CONCLUSIONS

This study suggests that underlying MBs do not predict incident HTf after acute ischaemic stroke. The clinical significance of MBs should be differentially evaluated according to the type of disease (intracerebral haemorrhage vs. HTf).

The prevalence of and risk factors for erosive oesophagitis and non-erosive reflux disease: a nationwide multicentre prospective study in Korea

BACKGROUND

Prospective nationwide multicentre studies that have evaluated endoscopic findings and reflux symptoms using a well-designed questionnaire are very rare.

AIM

To compare the prevalence rates of and risk factors for erosive oesophagitis and non-erosive reflux disease (NERD) in the Korean population.

METHODS

A gastroscopic examination was performed on 25 536 subjects who visited 40 Healthcare Centers for a health check-up. A gastro-oesophageal reflux questionnaire and multivariate analysis were used to determine the risk factors for erosive oesophagitis and NERD.

RESULTS

2019 (8%) and 996 subjects (4%) had erosive oesophagitis and non-erosive reflux disease, respectively; only 58% of subjects with erosive oesophagitis had reflux symptoms. Multivariate analysis showed that the risk factors for erosive oesophagitis and NERD differed, i.e. those of erosive oesophagitis were male, a Helicobacter pylori eradication history, alcohol, body mass index > or =25 and hiatal hernia. In contrast, the risk factors for NERD were female, age <40 and > or =60 vs. 40-59 years, body mass index <23 and a monthly income <$1000, glucose > or =126 mg/dL, smoking, a stooping posture at work and antibiotic usage.

CONCLUSIONS

The prevalence rates of erosive oesophagitis and NERD were 8% and 4%, respectively, in Korean health check-up subjects. The risk factors for erosive oesophagitis and NERD were found to differ, which indicates that their underlying pathogeneses are distinct.