[Efficacy and safety of endovascular therapy after 24 h from ischemic stroke onset in patients with acute anterior circulation ischemic stroke]

Objective: To explore the effectiveness and safety of endovascular treatment (EVT) for patients with acute anterior circulation ischemic stroke with symptom onset exceeding 24 h. Methods: In this retrospective cohort study, data were extracted from patients who underwent endovascular treatment for acute anterior circulation ischemic stroke at the First Hospital of Jilin University from February 2019 to April 2022. A total of 569 patients were included, with a mean age of 63 (54-70) years. Among them, 398 (69.9%) were male. The patients were divided into two groups based on symptom onset time:>24 h group and≤24 h group. Propensity score matching (PSM) was used to match the patients in a 1︰1 ratio between the>24 h group and the≤24 h group. Logistic regression was used to evaluate the impact of symptom onset time on outcome events. Results: Before PSM, compared with≤24 h group, the>24 h group had a younger age [56 (48, 64) vs. 64 (55, 70), Z=-3. 60, P<0.001]; lower proportion of prior atrial fibrillation [1.8% (1/57) vs. 21.1% (108/512), χ2=12.39, P<0.001]; lower proportion of wake-up stroke [7.0% (4/57) vs. 27.7% (142/512), χ2=11.54, P<0.001]; lower baseline NIHSS score [11.0 (7.5, 14.0) vs. 13.0 (10.0, 16.0), Z=-3.22, P<0.001]; and a higher American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology(ASITN/SIR) grading (P<0.001). After PSM, there were no significant differences in baseline characteristics between the two groups. There was no significant difference in the proportion of patients with a modified Rankin Scale (mRS) score≤2 at 90 days after surgery between the two groups (before matching: 42.0% vs. 40.4%, OR=0.745, 95%CI 0.407-1.362, P=0.339; after matching: 51.8% vs. 39.3%, OR=0.511, 95%CI 0.212-1.236, P=0.136). No significant differences were observed in the incidence of any safety outcomes between the>24 h group and the≤24 h group. Conclusion: For patients with acute anterior circulation ischemic stroke with symptom onset exceeding 24 h, EVT is feasible after strict radiological screening and has similar safety and effectiveness as for patients with symptom onset under 24 h.

[Effect of exosome derived from ovarian cancer cell on the differentiation of fibroblast]

Objective: To study the effects of exosome secreted by ovarian cancer (OC) cell on the differentiation and metastasis of normal fibroblasts (NFs). Methods: NFs were collected from patients who underwent hysteromyoma resection in the Affiliated Hospital of Qingdao University from May to December 2019. Exosome was extracted from the culture supernatant of SKOV3 cells by using ultra-high-speed centrifugation. The NFs were co-cultured with condition medium (CM), exosome of SKOV3 (SKOV3-exo) and control medium. The expression levels of fibroblast activation protein (FAP) and α-smooth muscle actin (α-SMA) were detected by real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) and western blot. The metastatic ability of NFs was detected by Transwell array. Results: Under the transmission electron microscope, the extracellular vesicles extracted from the culture supernatant of SKOV3 were 30-100 nm in diameter with cup holder-like bilayer membrane structure, and the protein expression levels of TSG101 and HSP27 in exosomes (1.00±0.05 and 1.12±0.13) were higher than those of ovarian cancer SKOV3 cells (0.22±0.21 and 0.36±0.14, respectively, P<0.05). PKH67 fluorescently labeled exosomes could be taken up by NFs. The expression levels of α-SMA and FAP mRNA in CM group(2.91±0.15 and 3.21±0.33)and SKOV3-exo group (3.50±0.21 and 4.63±0.24, respectively) were higher than that in blank group (1.00±0.06 and 1.00±0.13, P<0.05). The protein expression levels of α-SMA and FAP in CM group and SKOV3-exo group (0.89±0.11 and 1.25±0.09, 0.81±0.09 and 1.20±0.12) were higher than those in the blank group (0.12±0.31 and 0.11±0.19, respectively, P<0.05). The migrated numbers of cells in the CM group and SKOV3-exo group [(215.01±14.80) and (389.72±19.43), respectively] were higher than that in the blank group [(113.73±4.70), P<0.05]. Conclusion: The exosome secreted by SKOV3 cells can be taken up by NFs, which makes it to differentiate into cancer associated fibroblasts (CAFs) and significantly enhances its metastatic ability, indicating that OC cells may promote the transformation of normal ovarian mesenchymal fibroblasts to CAFs through exosome pathways, and then promote the development of ovarian cancer.

Association Between Level of Fibrosis, Rather Than Antiviral Regimen, and Outcomes of Patients With Chronic Hepatitis B

BACKGROUND & AIMS

We performed a propensity-score matched analysis to investigate whether entecavir, compared with lamivudine, can reduce risk of hepatocellular carcinoma (HCC) in patients with chronic hepatitis B after adjusting for level of fibrosis.

METHODS

We performed a retrospective study of 1079 patients with chronic hepatitis B who received first-line therapy with lamivudine (n = 435) or entecavir (n = 644) from 2006 through 2013. Only patients with available liver stiffness value measured by transient elastography were recruited. Liver cirrhosis was diagnosed by ultrasonography. To adjust for the imbalance of patients treated with lamivudine versus entecavir, we performed propensity-score matching (PSM), at a ratio of 1:1, using 7 factors (age, sex, hepatitis B e antigen, alanine aminotransferase, serum albumin, platelet count, and liver stiffness; PSM1) or 8 factors (variables of PSM1 plus ultrasonography measurements of cirrhosis; PSM2). Patients with virologic breakthrough or resistance mutations received rescue therapy.

RESULTS

Over the 7-year period, 91 patients developed HCC and 104 had liver-related events in the entire cohort. In multivariate analyses, level of fibrosis, but not antiviral regimen, was independently associated with risk of HCC (P < .05). The PSM1 group included 342 pairs of patients and the PSM2 group included 338 pairs. Similar proportions of patients given lamivudine versus entecavir developed HCC in each model (10.5% given lamivudine vs 9.9% given entecavir in PSM1 and 11.9% vs 12.6% in PSM2; all P > .05). When PSM was applied to patients with liver stiffness value ≤13 kPa or >13 kPa, patients given lamivudine versus entecavir still had similar cumulative rates of HCC development (all P > .05).

CONCLUSIONS

In a PSM analysis, we associated level of fibrosis, rather than antiviral regimen, with risk of HCC, when patients received appropriate rescue therapy in case of virologic breakthrough or resistance mutations.

A western validation of a novel gastric cancer prognostic model using American data

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Background: A novel prediction model, the Yonsei University Gastric Cancer Prediction Tool was developed by an international collaborative group (G6+) for accurate determination of 5-year overall survival of gastric cancer patients. This prediction model was created using a prospectively maintained single institution database of 12,399 patients and included clinically relevant factors not accounted for in the TNM staging system. This prediction model was validated using external data sets from Asia; its’ applicability in the American population has yet to be determined through a validated data set. Methods: Using the SEER dataset, 2014 release, all patients with gastric adenocarcinoma diagnosed between the years 2002 –2012 who underwent resection were selected. The following characteristics were selected for analysis: age, sex, gender, depth of tumor invasion, number of positive lymph nodes, total lymph nodes retrieved, presence of distant metastasis, extent of resection, and histology. These data were processed through a recently published prognostic nomogram to obtain concordance index (C-statistic) using the bootstrap method and calibration was assessed. This was compared to the current prognostic index, the TNM staging system. Results: A total of 26,019 possible patients were identified from the SEER database, years 2002-2012. Of these, 11,765 had complete datasets. Validation of the prognostication model revealed a C-statistic of 0.762 (95% CI 0.754-0.769). This is compared to the 7thTNM staging model, C-statistic 0.683 (95% CI 0.677-0.689). The new nomogram was found to be significantly more accurate with a p-value of < 0.001. Conclusions: Our study validates a novel prediction model for gastric cancer in the American patient population. Using this model, superior accuracy in prognosticating the 5-year survival of gastric cancer patients was confirmed in the western cohort strongly supporting its global applicability. This model also allows for inclusion of those who did not undergo adequate lymphadenectomy or who underwent a non-curative resection and can be a useful prediction tool for an increasing number of gastric cancer patients world-wide.

Clinical Benefit of Hepatic Arterial Infusion Concurrent Chemoradiotherapy in Locally Advanced Hepatocellular Carcinoma: A Propensity Score Matching Analysis

PURPOSE

The aim of this study was to evaluate whether hepatic arterial infusion concurrent chemoradiotherapy (CCRT) could improve overall survival (OS) in patients with locally advanced hepatocellular carcinoma (LAHCC).

MATERIALS AND METHODS

Two databases were reviewed from Yonsei Cancer Center (YCC) and Korean Liver Cancer Study Group (KLCSG) nationwide multi-center hepatocellular carcinoma (HCC) cohort. The CCRT group included 106 patients, with stage III-IV, Child-Pugh classification A, Eastern Cooperative Oncology Group performance status 0 or 1, who underwent definitive CCRT as the initial treatment at YCC. We used propensity score matching to adjust for seven clinical factors, including age, tumor size, TNM stage by the Liver Cancer Study Group of Japan, T stage, Barcelona Clinic Liver Cancer (BCLC) staging system, etiology of HCC, and portal vein invasion, which all differed significantly in the two databases. From the KLCSG cohort enrolled at 32 institutions, 106 patients for the non-CCRT group were defined.

RESULTS

After propensity score matching, all patient characteristics were balanced between the two groups. The CCRT group had better OS (median, 11.4) than the non-CCRT group (6.6 months, p=0.02). In multivariate analyses for all patients, CCRT (hazard ratio [HR], 1.48; 95% confidence interval [CI], 1.11 to 1.97; p=0.007), tumor size (HR, 1.08; 95% CI, 1.04 to 1.12; p < 0.001), and BCLC stage (HR, 0.54; 95% CI, 0.36 to 0.8; p=0.003) were independent prognostic factors for OS.

CONCLUSION

CCRT showed better OS for LAHCC patients. In LAHCC patients with a good performance and normal liver function, CCRT could be a feasible treatment option. All of these findings need to be validated in prospective clinical trials.

Increased risk of hepatocellular carcinoma in chronic hepatitis B patients with transient elastography-defined subclinical cirrhosis

Early detection of liver cirrhosis in its subclinical stage is of paramount importance to identify high-risk individuals for developing hepatocellular carcinoma (HCC). This study investigated whether transient elastography (TE) can identify patients with subclinical cirrhosis (SCC) who are at increased risk of developing HCC among chronic hepatitis B (CHB) patients without clinical evidence of cirrhosis. A total of 2,876 CHB patients without clinical cirrhosis who received TE examinations between April 2006 and December 2012 were enrolled in this prospective study. SCC was defined as a nonclinical cirrhosis, but with a liver stiffness (LS) value ≥13 kilopascals (kPa). Mean age of the study population was 46.1 years, and male gender was predominant (n = 1,775; 61.7%). Mean LS value was 7.9 kPa, and SCC was identified in 285 (9.9%) patients. During the median follow-up period of 48.9 months (range, 6.6-96.2), HCC developed in 16 patients (13.3 per 1,000 person-years) in the SCC group and 36 (3.4 per 1,000 person-years) in the non-SCC group. Cumulative incidence rate of HCC in the SCC group was significantly higher than that in the non-SCC group (P < 0.001, log-rank test). On multivariate analysis, SCC was independently associated with a risk of developing HCC, regardless of antiviral therapy (without antiviral therapy: hazard ratio [HR]: 4.680; 95% confidence interval [CI]: 1.187-18.441; P = 0.027; with antiviral therapy: HR, 3.344; 95% CI: 1.526-7.328; P = 0.003).

CONCLUSION

TE can identify CHB patients with SCC who are at increased risk of developing HCC, even when cirrhosis is not clinically apparent.

Anti-adhesive effect of a thermosensitive poloxamer applied after the removal of nasal packing in endoscopic sinus surgery: a randomised multicentre clinical trial

OBJECTIVE

To compare the efficacies of a thermosensitive poloxamer (TPX) and Merogel in preventing adhesion applied after the removal of nasal packing in endoscopic sinus surgery as a non-inferiority trial.

DESIGN

Randomised, multicentre, single-blind, active-controlled, matched-pair study.

SETTING

Yonsei University Gangnam Severance Hospital, Korea University Guro Hospital.

PARTICIPANTS

A total of 70 patients were enroled and underwent endoscopic sinus surgeries. Four of the patients did not complete their follow-up. Analysis of the 66 enroled patients having completed postoperative assessment was performed. The severity of rhinosinusitis was graded with a Lund-McKay CT score, and only those with bilateral disease and a CT score difference ≤2 between sinuses were included.

MAIN OUTCOME MEASURES

An independent rhinologist from a third institution through a blinded assessment with digital photoendoscopy of the middle meati bilaterally taken postoperatively.

RESULTS

In the blinded assessment, thermosensitive poloxamer (anti-adhesion rate: 92%) was similar to Merogel (anti-adhesion rate: 89%). Evaluation of the presence and grade of adhesion, oedema, and infection in the middle meatus revealed no significant differences between the thermosensitive poloxamer group and the Merogel group at all postoperative periods.

CONCLUSION

Anti-adhesive effects of thermosensitive poloxamer are similar to those of Merogel. Therefore, thermosensitive poloxamer can be considered a safe alternative to Merogel for preventing adhesion in patients undergoing endoscopic sinus surgeries, and further evaluation of thermosensitive poloxamer as an anti-adhesive and primary packing material compared with the control using no packing is needed.

Transient elastography-based risk estimation of hepatitis B virus-related occurrence of hepatocellular carcinoma: development and validation of a predictive model

Background

The purpose of this study was to develop and validate a novel transient elastography-based predictive model for occurrence of hepatocellular carcinoma (HCC).

Methods

A total of 1,250 patients with chronic hepatitis B and baseline liver stiffness values were recruited between May 2005 and December 2007. The predictive model for HCC occurrence was constructed based on a Cox proportional hazards model. We estimated baseline disease-free probabilities at 3 years. Discrimination and calibration were used to validate the model.

Results

HCC occurred in 56 patients during a median follow-up of 30.7 months. Multivariate analysis revealed that age, male gender, and liver stiffness values were independent predictors of HCC (all P<0.05), whereas hepatitis B virus DNA ≥20,000 IU/L showed borderline statistical significance (P=0.0659). We developed a predictive model for HCC using these four variables, which showed good discrimination capability, with an area under the receiver operating characteristic curve (AUROC) of 0.806 (95% confidence interval 0.738–0.874). We used the bootstrap method to assess discrimination. The AUROC remained largely unchanged between iterations, with an average value of 0.802 (95% confidence interval 0.791–0.812). The predicted risk of occurrence of HCC calibrated well with the observed risk, with a correlation coefficient of 0.905 (P<0.001).

Conclusion

This novel model accurately estimated the risk of HCC occurrence in patients with chronic hepatitis B.

Rapid and safe learning of robotic gastrectomy for gastric cancer: multidimensional analysis in a comparison with laparoscopic gastrectomy

BACKGROUND

The learning curve of robotic gastrectomy has not yet been evaluated in comparison with the laparoscopic approach. We compared the learning curves of robotic gastrectomy and laparoscopic gastrectomy based on operation time and surgical success.

METHODS

We analyzed 172 robotic and 481 laparoscopic distal gastrectomies performed by single surgeon from May 2003 to April 2009. The operation time was analyzed using a moving average and non-linear regression analysis. Surgical success was evaluated by a cumulative sum plot with a target failure rate of 10%. Surgical failure was defined as laparoscopic or open conversion, insufficient lymph node harvest for staging, resection margin involvement, postoperative morbidity, and mortality.

RESULTS

Moving average and non-linear regression analyses indicated stable state for operation time at 95 and 121 cases in robotic gastrectomy, and 270 and 262 cases in laparoscopic gastrectomy, respectively. The cumulative sum plot identified no cut-off point for surgical success in robotic gastrectomy and 80 cases in laparoscopic gastrectomy. Excluding the initial 148 laparoscopic gastrectomies that were performed before the first robotic gastrectomy, the two groups showed similar number of cases to reach steady state in operation time, and showed no cut-off point in analysis of surgical success.

CONCLUSIONS

The experience of laparoscopic surgery could affect the learning process of robotic gastrectomy. An experienced laparoscopic surgeon requires fewer cases of robotic gastrectomy to reach steady state. Moreover, the surgical outcomes of robotic gastrectomy were satisfactory.

Association between IL28B polymorphisms and spontaneous clearance of hepatitis B virus infection

BACKGROUND/AIMS

Single-nucleotide polymorphisms (SNPs) near the interleukin 28B gene (IL28B; interferon [IFN]-λ-3) are associated with outcomes of chronic hepatitis C virus (HCV) and hepatitis B virus (HBV) infection treated with peginterferon (PEG-IFN) alpha-based antiviral therapy. In this study, we investigated the influence of IL28B polymorphisms on spontaneous clearance of HBV infection in a large Korean cohort.

METHODS

Between January 2007 and June 2010, a total of 208 patients with chronic HBV infection and newly diagnosed HBV-related hepatocellular carcinoma were recruited as the CC group [HBsAg(+) for >6 months, anti-HBc(+), and anti-HBs(-)]. In addition, 351 organ donors were stratified into the UE group [n = 106; HBsAg(-), anti-HBc(-), and anti-HBs(-)] or the SC group [n = 245; HBsAg(-), anti-HBc(+), and anti-HBs(+)]. The SNaPshot ddNTP Primer Extension Kit (Applied Biosystems, Foster City, CA) was used for SNP detection. Direct full sequencing of the IL28B coding region was attempted.

RESULTS

Regardless of group, rs12979860 CC was most frequently identified (85.0% in UE, 85.9% in SC, and 93.5% in CC, respectively), whereas rs12979860 TT was not identified in any group. Similarly, rs12980275 AA and rs8099917 TT were most frequently identified (≥85%) regardless of group, whereas rs12980275 GG was identified in only one subject in the SC group. In addition, rs8099917 GG was not identified. The prevalences of CC in rs12979860, AA in rs12980275, and TT in rs8099917 were significantly higher in the CC group when compared with the UE and SC group (all P<0.05). Among 19 novel SNPs in the IL28B coding region, the proportions of 6 SNPs were significantly different among the UE, SC, and CC groups (all P<0.05).

CONCLUSIONS

The SNP upstream of IL28B that has the strongest genetic association with HCV recovery has an inverse influence on HBV recovery. Additional studies are needed to understand the mechanisms of this SNP in HBV infection.

Staging of adenocarcinoma of the esophagogastric junction: comparison of AJCC 6th and 7th gastric and 7th esophageal staging systems

BACKGROUND

Adenocarcinoma of esophagogastric junction (EGJ) is currently staged by the esophageal staging criteria according to the American Joint Committee on Cancer (AJCC) staging system, 7th edition. We compared the performance of 6th gastric (G6), 7th gastric (G7), and 7th esophageal (E7) staging systems.

METHODS

A total of 202 curatively resected adenocarcinomas of EGJ were analyzed. Patient outcomes were assessed according to G6, G7, and E7 staging. Tumor invasion to the subserosal or serosa layer was regarded as invasion to the adventitia for E7 staging. Performance was measured based on monotonicity (decreasing survival with increasing stage), distinctiveness (survival difference between different stages), and homogeneity (homogenous survival in the same stage).

RESULTS

Each staging system was monotonous except for T1-2N0 lesions of E7. This was related to the introduction of histologic grade in E7 staging. Distinctiveness in each staging system was variable. As for the homogeneity, patients whose disease was staged as Ib (E7) exhibited different survival when reassessed by G6 and G7; again, this was related to histologic grading. Patients with IIIb (G7) and IIIc (E7) disease had different survival when reassessed by G6 staging, reflecting the poorer survival of patients with more than 15 lymph node metastases.

CONCLUSIONS

Staging of EGJ cancer based on the current AJCC, 7th edition, criteria of esophageal cancer staging has several limitations. We recommend considering modifications of the following in future updates of the staging system: accurate anatomical definition of tumor depth, removal of histologic grade from staging parameters, and classification of more than 15 lymph node metastases as a highly advanced stage.

Prediction of gastric cancer survival after gastrectomy using nomogram from 10,621 patients: Developed and validated using international databases

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Background: Patient-specific prognosis for gastric cancer is difficult to determine. Internationally accepted AJCC TNM staging system currently provides the best framework for predicting a patient’s prognosis. However, a major weakness of the TNM system is that significant survival differences exist even within its subgroups. The objective of this study was to create a simple tool to accurately predict patient survival from gastric cancer after gastrectomy. Methods: Between December 1986 to March 2007, 10,621 patients were surgically treated for gastric cancer at a single institution and observed until death. A nomogram was determined using Cox proportional hazard regression for multivariate analysis and the Kaplan-Meier method for estimation of 5-year overall survival. Overall survival was the endpoint. The predicted probability of the nomogram for actual overall survival was compared to the 7th edition AJCC TNM staging system. Then, the nomogram was validated using external data sets from four different institutions from Korea, Japan, and China. The number of patients in each data set was 1573 (A), 297 (B), 78 (C) and 767 patients (D). Results: Variables selected for the prediction model included age, gender, depth of invasion, number of metastatic lymph nodes (LN), total number of LN retrieved, and the presence of distant metastasis. The newly developed nomogram more accurately predicted a gastric cancer patient’s overall 5-year survival than the 7th Edition AJCC TNM system (p=0.0024) with area under the curve 0.8023 (our nomogram) and 0.7869 (AJCC TNM staging system). The concordance indexes of the different validation sets were 0.824 (A), 0.835 (B), 0.916 (C), and 0.767 (D). Conclusions: Our simple nomogram requires minimal patient and tumor information. It accurately predicts the 5-year overall survival for a patient with gastric cancer after surgical resection. Already internationally validated with data sets of various sample sizes and from different countries, our new nomogram provides a useful tool for prognostication after gastrectomy with wide applicability in different patient populations and institutions.

Performance of transient elastography for the staging of liver fibrosis in patients with chronic hepatitis B: a meta-analysis

BACKGROUND

Transient elastography (TE), a non-invasive tool that measures liver stiffness, has been evaluated in meta-analyses for effectiveness in assessing liver fibrosis in European populations with chronic hepatitis C (CHC). However, these data cannot be extrapolated to populations in Asian countries, where chronic hepatitis B (CHB) is more prevalent. In this study, we performed a meta-analysis to assess the overall performance of TE for assessing liver fibrosis in patients with CHB.

METHODS

Studies from the literature and international conference abstracts which enrolled only patients with CHB or performed a subgroup analysis of such patients were enrolled. Combined effects were calculated using area under the receiver operating characteristic curves (AUROC) and diagnostic accuracy values of each study.

RESULT

A total of 18 studies comprising 2,772 patients were analyzed. The mean AUROCs for the diagnosis of significant fibrosis (F2), severe fibrosis (F3), and cirrhosis (F4) were 0.859 (95% confidence interval [CI], 0.857-0.860), 0.887 (95% CI, 0.886-0.887), and 0.929 (95% CI, 0.928-0.929), respectively. The estimated cutoff for F2 was 7.9 (range, 6.1-11.8) kPa, with a sensitivity of 74.3% and specificity of 78.3%. For F3, the cutoff value was determined to be 8.8 (range, 8.1-9.7) kPa, with a sensitivity of 74.0% and specificity of 63.8%. The cutoff value for F4 was 11.7 (range, 7.3-17.5) kPa, with a sensitivity of 84.6% and specificity of 81.5%.

CONCLUSION

TE can be performed with good diagnostic accuracy for quantifying liver fibrosis in patients with CHB.

Effect of sevoflurane on grafted kidney function in renal transplantation

BACKGROUND

The objective of this retrospective study was to determine if there are any differences in grafted kidney function in recipients of kidney transplantation (KT) when donors and recipients were anesthetized with sevoflurane compared to desflurane.

METHODS

Seventy-three pairs of donors-recipients were anesthetized with sevoflurane (Sevo group) and 71 pairs were anesthetized with desflurane (Des group). We retrospectively investigated the blood urea nitrogen (BUN) levels, creatinine (Cr) levels, and estimated glomerular filtration rates (eGFR) of the recipients in both groups for 1 year postoperatively. We tested non-inferiority for serum creatinine at discharge and 1 year after KT. Short-term (1 year) outcomes of KT were assessed by the incidence of delayed graft function (DGF), acute rejection episodes (ARE), and graft failure.

RESULTS

There were no differences in BUN, Cr, eGFR, or outcomes of KT at 1 year postoperatively. Specifically, the 95% confidence interval for the difference in creatinine levels between the Sevo and Des groups was less than the margin of equivalence at the time of discharge and 1 year after surgery. The occurrences of DGF, ARE, and graft failure were comparable between the groups.

CONCLUSIONS

Compared to desflurane, sevoflurane had no adverse effects on grafted renal function or on the short-term outcome of renal transplantation.

Low-dose abdominal CT for evaluating suspected appendicitis

BACKGROUND

Computed tomography (CT) has become the predominant test for diagnosing acute appendicitis in adults. In children and young adults, exposure to CT radiation is of particular concern. We evaluated the rate of negative (unnecessary) appendectomy after low-dose versus standard-dose abdominal CT in young adults with suspected appendicitis.

METHODS

In this single-institution, single-blind, noninferiority trial, we randomly assigned 891 patients with suspected appendicitis to either low-dose CT (444 patients) or standard-dose CT (447 patients). The median radiation dose in terms of dose-length product was 116 mGy·cm in the low-dose group and 521 mGy·cm in the standard-dose group. The primary end point was the percentage of negative appendectomies among all nonincidental appendectomies, with a noninferiority margin of 5.5 percentage points. Secondary end points included the appendiceal perforation rate and the proportion of patients with suspected appendicitis who required additional imaging.

RESULTS

The negative appendectomy rate was 3.5% (6 of 172 patients) in the low-dose CT group and 3.2% (6 of 186 patients) in the standard-dose CT group (difference, 0.3 percentage points; 95% confidence interval, -3.8 to 4.6). The two groups did not differ significantly in terms of the appendiceal perforation rate (26.5% with low-dose CT and 23.3% with standard-dose CT, P=0.46) or the proportion of patients who needed additional imaging tests (3.2% and 1.6%, respectively; P=0.09).

CONCLUSIONS

Low-dose CT was noninferior to standard-dose CT with respect to negative appendectomy rates in young adults with suspected appendicitis. (Funded by GE Healthcare Medical Diagnostics and others; ClinicalTrials.gov number, NCT00913380.).

A scoring system for prediction of lateral neck node metastasis from papillary thyroid cancer

Lateral neck node metastasis is an important prognostic factor in thyroid carcinoma. We developed a scoring system for use in prediction of lateral neck node metastasis from papillary thyroid cancer. In this study, 161 consecutive patients were included in the training data set. This scoring system, named the Yonsei Estimated Value (YEV) for lymph node metastasis in papillary thyroid cancer, was developed on the basis of results from multivariate logistic regression analysis of preoperative clinical and radiologic data. Sixty eight consecutive patients were included for testing of the validity of the scoring system. The equation for prediction of lateral neck node metastasis was follows:YEV (Yonsei Estimated Value) = 1/(1+X)X = Exp (5.333-[0.902 × sex]+[0.036 × age]-[1.020 × tumor size]-[0.177 × lymph node size]-[0.032 × lymph node density])When the YEV was 0.3 or more, the probability of lateral neck node metastasis was 79.0%, with sensitivity of 76.3%, specificity of 69.8%, positive predictive value of 56.7%, and negative predictive value of 85.1% in the training set. When fine needle aspiration biopsy for suspicious lateral neck nodes is not possible, or the results are inadequate, our scoring system for prediction of lateral neck node metastasis can be helpful in optimization of the surgical extent for each patient.

The ratio of intra-tumoral regulatory T cells (Foxp3+)/helper T cells (CD4+) is a prognostic factor and associated with recurrence pattern in gastric cardia cancer

BACKGROUND

TILs have been reported to be a prognostic factor in human cancers. We assessed the prognostic significance of tumor-infiltrating regulatory T cells in gastric cardia cancer.

METHODS

We retrospectively reviewed the database of Severance Hospital for patients who underwent curative resection of gastric cardia cancer from Jan 2000 to Dec 2006 and identified 180 patients. Immunohistochemistry for TIL subsets was performed against CD3, CD4, CD8, Foxp3, and granzyme B in the resected tumor specimens. The absolute numbers and relative ratios of positively stained lymphocytes for each subset were evaluated.

RESULTS

A high Foxp3/CD4 ratio was identified as an unfavorable prognostic factor for overall survival (OS) using univariate and multivariate analysis of all immunologic variables. Patients group with high Foxp3/CD4 ratio was associated with loco-regional recurrence (P = 0.033). In multivariate analysis for clinical and immunologic variables, the nodal status (hazards ratio--HR: 3.863, confidence interval--CI: 1.664-8.966, P = 0.002), depth of invasion (HR: 3.607, CI: 1.443-9.019, P = 0.006), and Foxp3/CD4 ratio (HR: 1.812, CI: 1.022-3.212, P = 0.042) were identified as independent prognostic factors for OS.

CONCLUSIONS

A higher regulatory T cells/helper T cells ratio is associated with an unfavorable prognosis and loco-regional recurrence pattern in gastric cardia cancer.

Acute appendicitis in young adults: low- versus standard-radiation-dose contrast-enhanced abdominal CT for diagnosis

PURPOSE

To compare low and standard radiation doses in intravenous contrast material-enhanced abdominal computed tomography (CT) for the diagnosis of acute appendicitis in young adults.

MATERIALS AND METHODS

The institutional review board approved this retrospective study and waived informed consent. The study included 257 patients (age range, 15-40 years) who underwent CT for suspected appendicitis performed by using a low radiation dose (n = 125) or a standard radiation dose (n = 132). Receiver operating characteristic (ROC) analysis, Fisher exact tests, and Mann-Whitney U tests were used to compare the diagnosis of appendicitis and diagnostic confidence as recorded in prospective CT reports between the two groups.

RESULTS

For 55 low-radiation-dose (median dose-length product, 122 mGy · cm) and 44 standard-dose (median dose-length product, 544 mGy · cm) examinations, one of two abdominal radiologists made primary reports that served as final reports. For the remaining examinations, on-call radiologists with differing levels of experience issued preliminary reports and the two abdominal radiologists then provided final reports. In the primary reports, the low- and standard-dose CT groups did not significantly differ in area under the ROC curve (0.96 vs 0.97, P = .76), sensitivity (90% [38 of 42] vs 89% [47 of 53], P > .99), or specificity (92% [76 of 83] vs 94% [74 of 79], P = .74) in the diagnosis of appendicitis. There was also no significant difference between the two groups in the confidence level when diagnosing (P = .71) or excluding (P = .20) appendicitis in the primary reports. Similar results were observed for the final reports. The two dose groups also did not significantly differ in terms of appendiceal visualization, diagnosis of appendiceal perforation, or sensitivity for alternative diagnoses.

CONCLUSION

Low-dose CT may have comparable diagnostic performance to standard-dose CT for the diagnosis of appendicitis in young adults.

Oral vitamin B12 replacement: an effective treatment for vitamin B12 deficiency after total gastrectomy in gastric cancer patients

BACKGROUND

Vitamin B12 deficiency is a common long-term sequelae after total gastrectomy. Intramuscular injection of vitamin B12 is the only known treatment. We investigated the efficacy and safety of oral vitamin B12 replacement for gastric cancer patients with vitamin B12 deficiency after total gastrectomy.

METHODS

We performed a single-arm, open-label, fixed-drug dosage, prospective study (NCT00699478) involving gastric cancer patients who underwent total gastrectomy. Vitamin B12-deficient (<200 pg/ml) patients (n = 30) received daily oral vitamin B12 (dosage: 1500 μg mecobalamin) administration for 3 months. The primary outcome measurement was serum vitamin B12. The secondary outcome measurements were improvement of neurologic symptoms and hematologic findings (serum folate, homocysteine, ferritin, iron, total iron binding capacity, transferrin, and mean corpuscular volume). For comparison, another group of vitamin B12 deficient patients (n = 30) received intramuscular vitamin B12 injections (dosage: 1000 μg cyanocobalamin) weekly for 5 weeks and monthly thereafter for a total of 3 months in a separate study period.

RESULTS

In both groups, mean serum vitamin B12 increased after 30 days of treatment and was maintained up to 90 days. No adverse effects related to oral or intramuscular vitamin B12 replacements were noted. Both groups showed decreased homocysteine levels. Before treatment, 29 patients in the oral vitamin B12 group had neurologic symptoms related to vitamin B12 deficiency. After oral vitamin B12 treatment, 28 patients experienced symptom relief, and 16 patients were symptom free.

CONCLUSIONS

Oral vitamin B12 replacement is an effective and safe treatment for vitamin B12 deficiency in gastric cancer patients after total gastrectomy.

Assessment of nurses' nutritional knowledge regarding therapeutic diet regimens

Metabolic diseases and cardiovascular disease (CVD), the incidence of which is currently increasing in Korea, can be managed well with dietary education and modification. However, it has yet to be established whether nurses have sufficient knowledge to impart appropriate nutritional counseling to patients with these diseases. Our study involved 506 nurses working at Asan Medical Center, Samsung Medical Center, and Seoul National University Hospital between March and May, 2006. The questionnaire was comprised of 42 diet-related questions pertaining to diabetes, obesity, and CVD. Nurses' correct-response rate for overall nutritional knowledge was worse than reported in Western countries (58.4%), and particularly so with regard to obesity and CVD. Although many nurses were aware of the therapeutic aspects of nutrients in relation to CVD, most of them had limited knowledge about low-cholesterol diets and sources of water-soluble fiber, fatty acids and the specific food items that prevent CVD. Our results suggest that there is an urgent need to update the contents of nutrition education for nurses to reflect the current changes in the Korean diet and the increasing incidence of metabolic diseases and CVD.

Childhood risk factors in Korean women with anorexia nervosa: two sets of case-control studies with retrospective comparisons

OBJECTIVE

The aim of this study was to investigate the characteristics of the risk factors for anorexia nervosa (AN) in Korean women.

METHOD

Two sets of case-control comparisons were conducted, in which 52 women with lifetime AN from Seoul, S. Korea, were compared with 108 Korean healthy controls and also with 42 women with lifetime AN from the UK in terms of their childhood risk factors. A questionnaire designed to conduct a retrospective assessment of the childhood risk factors was administered to all participants.

RESULTS

The Korean AN women were more likely to report premorbid anxiety, perfectionism, and emotional undereating and were less likely to report having supportive figures in their childhood than the Korean healthy controls. There were no overall differences in the childhood risk factors between the Korean and British women with AN.

DISCUSSION

Premorbid anxiety, perfectionism, less social support, and emotional undereating merit attention as risk factors in Korean AN. The current results are informative, but an epidemiologically robust prospective case-control study would be needed to validate these findings.

[Natural history of HBeAg negative chronic hepatitis B virus infection: a cohort study]

BACKGROUND/AIMS

The long-term virologic and biochemical changes in patients with HBeAg negative HBV infection, especially in Asia, remain unclear. To address this issue, we conducted a 3 year- retrospective, cohort study.

METHODS

A total of 157 patients with HBeAg negative HBV infection who were monitored without treatment were reviewed between January 1999 and March 2004. Those patients were followed up every 3 months with liver function tests and serologic tests. All patients were stratified into 3 groups; inactive carrier (IC), viremic carrier (VC) and chronic hepatitis (CH). Serum HBV DNA was measured by a hybridization assay (sensitivity: 1.4 x 10(5)) genomes/mL, Digene Diagnostics, Silver Spring, USA).

RESULTS

The median age of enrolled patients was 42.7 years (M:F=2.3:1). By single time-point observations, the 3 year-cohort prevalence of HBeAg negative CH varied from 12.7 to 35.8% (median 20.7%) HBeAg negative CH was accumulated over time (P=0.002) and transition rates among three groups after 3 years of follow-up are as follows: IC to CH, 6.0%; IC to VC, 4.1%; VC to CH, 23.2%. VC seems to be a disease state in the middle of transition from IC to CH.

CONCLUSIONS

We demonstrated the dynamic changing patterns of HBeAg negative CH with time, of which the change from IC or VC to CH was dominant.

Oncocytoma of the spinal cord causing paraplegia – a case report

STUDY DESIGN

Case report.

OBJECTIVES

To describe a rare case of oncocytoma arising from the spinal cord in a 40-year old woman.

SETTING

Republic of Korea.

METHODS

The patient's history, physical examination, radiological and pathological findings were reviewed.

RESULTS

A 40-year-old woman presented with 3-month history of low back pain. Magnetic resonance imaging revealed an intradural extramedullary mass located between L1 and L4. She refused any surgical treatment and so was discharged. At 10 days after discharge, an emergency operation was performed because of sudden paralysis in both lower extremities. The confirmed diagnosis is oncocytoma. At 4 months after surgery, the patient failed to obtain neurological recovery from complete paraplegia.

CONCLUSIONS

Since the progression of an intradural extramedullary mass that shows minor neurological symptoms can lead to complete paraplegia in a short time, close observation and early surgical decompression are necessary.

P63 and EGFR as prognostic predictors in stage IIB radiation-treated cervical squamous cell carcinoma

OBJECTIVES

The purpose of this study was to determine the relation between p63, p53-related gene, epidermal growth factor receptor (EGFR), and spontaneous apoptosis in relation to radiotherapy in patients with FIGO stage IIB cervical carcinoma, who had undergone radiation and concurrent chemotherapy, retrospectively.

METHODS

Eighty-four patients with FIGO stage IIB squamous cell carcinoma (SCC) of the uterine cervix, who were treated with radiotherapy and concurrent chemotherapy between 1991 and 1996, were included in the present study. The clinicopathologic features, patterns of treatment failure, and survival data were compared with the expressions of p63 and EGFR, which were determined by immunohistochemistry and with apoptosis by TUNEL on tissue-arrayed slides. Univariate and multivariate analyses were performed to determine the prognostic factors that influence patient survival.

RESULTS

Overall the indices of the expressions of p63 and EGFR in stage IIB cervical carcinoma were 18.7 and 26.6%, respectively, and these were found to be correlated. EGFR expression was significantly associated with extrapelvic failure (P = 0.03), whereas p63 was associated with locoregional failure (P = 0.03). The spontaneous apoptotic index showed no prognostic value, but the immunoreactivities of p63 and EGFR were associated with a worse prognosis by both univariate (P = 0.01 and 0.04, respectively) and multivariate analysis (95% CI:2.0-4.4, RR:3.2 and 95% CI:4.9-8.7, RR:6.7, respectively).

CONCLUSIONS

The expression of p63 gene is associated with poor survival and locoregional failure, whereas EGFR expression was found to be a prognostic predictor of extrapelvic failure. Both molecules were found to be potent molecular risk factors in patients with FIGO stage IIB SCC of the uterine cervix, who had received radiotherapy and concurrent chemotherapy.

A dominant antigenic region of the hantaan virus nucleocapsid protein is located within a amino-terminal short stretch of hydrophilic residues

The nucleocapsid (N) protein of the Hantaan virus (HTNV) is a major viral antigen that induces a strong antibody response during the acute phase of infection. By immunoblot analyses of the recombinant N proteins using human sera of the hemorrhagic fever with renal syndrome (HFRS), we have confirmed previous finding by other investigators of the presence of a highly antigenic region near the amino terminus of the HTNV N protein. We have further located the antigenic region within a short stretch of hydrophilic sequences between the 26 and the 46th amino acid residues. The recombinant glutathione S-transferase fusion proteins containing this region was expressed as a soluble form in a large quantity in Escherichia coli, and purified by a single-step affinity chromatography. The recombinant antigen also showed a similar, but a weaker reactivity with human antisera to Seoul virus (SEOV), the virus most closely related to HTNV.

The analysis of Plasmodium vivax Duffy receptor binding domain gene sequence from resurgent Korea isolates

The Duffy binding domain gene structures of Plasmodium vivax facilitate the invasion of erythrocytes. Human erythrocytes that lack Duffy blood group antigens are resistant to invasion by P. vivax. We have sequenced the Duffy binding domain gene from eight P. vivax isolates collected from malaria cases in South Korea. When compared to isolates from other regions in the world, the amino acid sequences of the Korean isolates showed unique variations in region II. From 606 sequenced amino acids, 32 variations were found. Of these, three variations were regularly found in positions 424, 437 and 503 of the Sal-1 amino acid sequence. In region III, six isolates had a loss of the 30 bp (FAESTKSAE) insert. However, six isolates had 6 bp (SD) inserts at the end of region III. Two cases had a reverse pattern. Our results suggest that the P. vivax currently found in South Korea are unique when compared to other isolates and can be divided, by the analysis of their molecular structure, into two strains.

Protease activity and host cell binding of the 42-kDa rhoptry protein from Toxoplasma gondii after secretion

Three proteases were identified in the excretory/secretory proteins (ESP) from Toxoplasma gondii by the gelatin acrylamide gel electrophoresis (GAGE), of which the molecular masses were 80, 70, and 42 kDa. One of the proteases with 42 kDa was reactive to a monoclonal antibody (mAb), Tg786 clone, which was localized in the rhoptry of T. gondii by immunohistochemistry. The protease was maximally active at the pH range between 7.5 and 8.5, and was sensitive to inhibition by TPCK and EGTA. The gelatinolytic activity of the protease was dependent on the concentration of calcium ion. The protease was active only in the millimolar ranges of calcium but not in micromolar ranges, implicating that the secretion is critical event for the activation of the protease. The secreted protease was shown to bind to the host cells upon Western blot and immunofluorescence analysis. It is suggested that the protease may target to the plasma membrane of the host cells, which provides appropriate environment for the entry of the parasite into host cells. The mAb (Tg786) of T. gondii also reacted with a protein of the same size and equivalent locality of rhoptry in Neospora caninum, a similar Apicomplexan protozoa, suggesting that secreted protease mediates a common function in the mechanism of entry into host cells.

Molecular genetic analysis of reovirus isolated in Korea

Reovirus isolates from human, striped-field mouse (Apodemus agrarius) and Korean field mouse (A. peninsulae) in Korea showed extensive variability in the patterns of electrophoretic migration of the double-stranded RNA (dsRNA) genome segments. Hemagglutination inhibition (HI) test was performed for serotype determination of 12 reovirus isolates. To clarify genetic diversity and molecular phylogeny of Korean reoviruses, L1, S3 and S4 genomic segments of reoviruses were amplified by RT-PCR and directly sequenced. Among 12 reovirus strains, 9 strains were type 3 and 3 strains were type 2. The L1 was highly conserved showing 91.5-100%, 94.7-100% similarities among Korean isolates, and 77.5-97.9%, 92.6-96.8% similarities compared to other reference strains of each genotypes at nucleotide and amino acid levels, respectively. In S3 and S4 segments, 84.4-99.3%, 72.3-99% nucleotide sequence similarities and 92-99.3%, 89.1-98.4% amino acid sequence similarities among Korean isolates were observed, and 70.8-93.9%, 72.3-98.7% nucleotide sequence similarities and 81.8-100%, 88.3-97.7% amino acid sequence similarities compared with other reference strains of each genotype were observed, respectively. Phylogenetic analyses based on the S3 and S4 nucleotide sequences indicate that genotypes of reovirus are more related with geographic differences rather than host species or date of isolation.

Molecular cloning and characterization of peroxiredoxin from Toxoplasma gondii

A cDNA of 1.1 kb comprising the gene encoding the peroxiredoxin of Toxoplasma gondii (TgPrx) has been cloned. The open reading frame of 591 bp was translated into a protein of 196 amino acids with a molecular mass of 25 kDa. Conserved 2 cysteine domains of Phe-Val-Cys-Pro and Glu-Val-Cys-Pro indicated TgPrx belonged to 2-Cys Prx families. TgPrx showed the highest homology with that of Arabidopsis thaliana by 53.9% followed by Entamoeba histolytica with 39.5% by the amino acid sequence alignment. Polyclonal antibody against recombinant TgPrx detected 25 kDa band in T. gondii without binding to host cell proteins. TgPrx was located in the cytoplasm of T. gondii extracellularly or intracellularly by immunofluorescence assay. The expression of TgPrx was increased as early as 30 min after the treatment with artemisinin in the intracellular stage, while no changes in those of host Prx I and TgSOD. This result implies that TgPrx may function as an antioxidant protecting the cell from the attack of reactive oxygen intermediates. It is also suggested that TgPrx is a possible target of chemotherapy.

Molecular epidemiology of hepatitis A virus in Korea

BACKGROUND

The prevalence of antibodies for hepatitis A virus (anti-HAV) in adolescents and young adults has decreased remarkably following the economic growth in Korea. As a result, this age group has a high risk for HAV infection paradoxically, and over 1500 cases of clinically overt hepatitis A occurred in 1998. Human isolates of hepatitis A virus (HAV) are categorized within four genotypes (I, II, III, and VII). In some geographic regions, closely related isolates cluster, suggesting endemic spread of the virus, while in other regions multiple genotypes circulate. Virtually no data are available with regard to the genetic relatedness of Korean strains of HAV.

METHODS AND RESULTS

A 168 base pair segment encompassing the putative VP1/2A junction of the HAV genome was amplified by RT-PCR and sequenced in sera of 18 Korean patients with a sporadic form of acute hepatitis A. Pairwise comparisons of the nucleic acid and amino acid sequences of 18 Korean isolates with one another revealed that the Korean isolates showed > 94.6% and > 96.4% identity, respectively. All of the 18 Korean isolates clustered within genotype IA, irrespective of the geographic locations and the time that hepatitis occurred. Unique amino acid sequence changes that had never been reported in genotype IA were found in nine of the 18 isolates. These changes were Gln-->Ser and Lys-->Arg in 2A-19 and 2A-10 amino acid positions.

CONCLUSION

The presence of single genotype and unique mutations may be related with the circulation of endemic HAV over a long period of time in Korea.

The analysis of circumsporozoite-protein gene sequences from South Korean isolates of Plasmodium vivax

The amino-acid sequences corresponding to the circumsporozoite protein (CSP) of Plasmodium vivax fall into two main types, VK210 and VK247, each of which has a characteristic tandem repeat. When the repetitive domains of the CSP gene from six isolates of P. vivax from South Korea were sequenced they were found to show a total of 20 tandem amino-acid repeats, and repeat patterns that are regular and distinct from those of other P. vivax isolates. The amino-acid sequences of the South Korean parasites were found to be most similar to those of three isolates from China (CH-3, CH-4, and CH-5) and, particularly, to one from North Korea. A sequence (AGGNAANKKAEDAGGNA) and two repeats of the sequence GGNA found in the North Korean parasites were found in all six isolates from South Korea. The South Korean parasites investigated appear phylogenetically identical and unique to the Korean peninsula.

Genetic diversity of Apodemus agrarius-borne hantaan virus in Korea

Hantaan (HTN) virus, the etiologic agent of clinically severe hemorrhagic fever with renal syndrome (HFRS), was first isolated in 1976 from lung tissues of striped field mice (Apodemus agrarius) captured in Songnae-ri, Kyungki-do, Korea. To clarify the genetic diversity and phylogenetic relationship among Korean strains of HTN virus, viral sequences of the partial S and M segments were amplified from lung tissues of 24 seropositive striped field mice captured between 1989 and 1998 at 11 sites in South Korea. The 771-nucleotide (nt) S segment sequences (coordinates 432 to 1202) of HTN virus strains from Yangju-kun differed by 10 to 40 nt (1.3 to 5.2%) from virus strains from Pocheon-kun, Songnae-ri and Nonsan-kun. Similar degrees of genetic variation were found in the G1 and G2 glycoprotein-encoding M segment. Phylogenetic trees, based on the partial S and M segments and generated by the maximum parsimony and neighbor-joining methods, demonstrated that virus strains from various geographic regions in South Korea showed a tendency to form two phylogenetic subgroups and were evolutionarily distinct from HTN virus strains from the People's Republic of China.

Instrumental and bioanalytical measures of persistent organochlorines in blue mussel (Mytilus edulis) from Korean coastal waters

Blue mussels (Mytilus edulis) collected from 34 locations along the south and east coast of Korea were analyzed for polychlorinated biphenyls (PCBs) and organochlorine (OC) pesticides. Maximum concentrations of PCBs and total OC pesticides were 98.5 and 20.5 ng/g, wet weight, respectively. Extracts were fractionated by Florisil chromatography and each fraction was screened for dioxin-like activity in vitro, using recombinant rat hepatoma cells (H4IIE-luc). Fraction 2 (F-2), which contained hexachlorocyclohexanes, chlordanes, p,p'-DDD, and p,p'-DDT, generally elicited significant dioxin-like activity compared to control, whereas Fraction 1 (F-1), which contained PCBs, p,p'-DDE, and hexachlorobenzene, did not. The greatest magnitude of dioxin-like response observed was 44% of the maximum response elicited by a 2,000 pM 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) standard. The relatively low magnitudes of dioxin-like response observed for F-1 samples were consistent with the relatively low PCB concentrations. At concentrations equal to the maximum observed in the mussel samples, neither individual OC pesticides nor a mixture of OC pesticides yielded a significant dioxin-like response in the H4IIE-luc assay. Thus, the concentrations of OC pesticides in F-2 did not appear to have accounted for the dioxin-like activity observed. This suggests the presence of unidentified and/or unknown, acid-stable, dioxin-like compounds in F-2. This study suggests that in vitro bioassays are useful in assessing the contamination of mussels collected from coastal marine locations.

Phylogenetic analysis of the small hydrophobic (SH) gene of mumps virus in Korea: identification of a new genotype

Viral RNAs extracted from fifteen mumps virus isolated from throat swab, saliva, blood, urine or CSF during mumps epidemics between 1997-1998 in Korea were amplified by reverse transcriptase-polymerase chain reaction (RT-PCR) and compared by nucleotide sequencing of the small hydrophobic (SH) gene. The deduced amino acid sequences of the SH gene were aligned with the published sequences of mumps virus isolated in different geographic areas. A comparison of the SH gene of mumps viruses in Korea indicated 96.2-100% and 91.2-100% similarity at the nucleotide and amino acid levels, respectively. Phylogenetic analysis, using the neighbor-joining method, showed that Korean mumps virus strains formed a genetically distinct monophyletic group from previously reported genotypes based on the 315-bp length nucleotide and 57 deduced amino acid sequences of the SH gene, and possibly be designated as a new genotype (I).

Cloning and expression of a cysteine proteinase gene from Paragonimus westermani adult worms

A gene encoding a cysteine proteinase from Paragonimus westermani has been cloned and expressed in Escherichia coli. The cysteine proteinase cDNA fragment was amplified by reverse transcription-polymerase chain reaction (RT-PCR) using degenerate oligonucleotide primers derived from the conserved active site of the cysteine proteinase. The 5' and 3' regions of the gene were amplified using a PCR technique for the rapid amplification of cDNA ends. The cloned gene has an open reading frame of 687 bp and deduced amino acid sequence of 229. Sequence analysis and alignment showed significant homologies with the eukaryotic cysteine proteinases and conservation of the Cys, His, and Asp residues that form a catalytic triad. Analysis of the expressed protein on sodium dodecyl sulfate polyacrylamide gel electrophoresis showed that the molecular weight of the protein was approximately 28.5 kDa. The expressed protein reacted with the sera of patients with paragonimiasis but not with the sera of fascioliasis and clonorchiasis. These results suggest that the expressed protein may be valuable as a specific diagnostic material for the immunodiagnosis of paragonimiasis.

Isolation of a cDNA encoding a 31-kDa, pathogenesis-related 5/thaumatin-like (PR5/TL) protein abundantly expressed in apple fruit (Nalus domestica cv. Fuji)

A fruit-specific and pathogenesis-related 5/thaumatin-like (PR5/TL), 31-kDa protein was isolated by 2D-PAGE from fully-grown apples (Malus domestica cv. Fuji) and named Mdtl1 (Malus domestica thaumatin-like protein 1). Using the N-terminal sequence of the protein, the full-length cDNA encoding Mdtll was isolated. The cDNA clone (Mdtl1) consists of 944 bp with an open reading frame (ORF) of 744 bp encoding a protein of 247 amino acids. The deduced amino acid sequence of Mdtl1 shows high similarity to the sequences of PR5/TL proteins. Mdtl1 is a slightly acidic protein with a putative signal peptide and a putative N-glycosylation site, and lacks a C-terminal extension. This suggests that Mdtl1 is an apoplastic glycoprotein. Results of northern blotting indicated that expressions of Mdtl1 are developmentally regulated. Southern blot analysis showed that Mdtl1 may be present as a single copy, and there exist other genes closely related to Mdtl1 in the apple genome.

Analysis of Plasmodium vivax merozoite surface protein-1 gene sequences from resurgent Korean isolates

The merozoite surface protein-1 (MSP-1) of Plasmodium vivax exhibits great antigenic diversity among different isolates of this parasite. This antigen is a useful genetic marker for studying the polymorphism of natural P. vivax parasite populations. One or more of these populations has been responsible for resurgent malaria now occurring in Korea. This paper reports the analysis of a highly polymorphic region between interspecies conserved blocks 5 and 6 of the MSP-1 gene, using the polymerase chain reaction to amplify the DNA fragment encompassing these regions from 25 Korean isolates, followed by sequencing. Almost all amino acid sequences of Korean isolates were nearly identical to that of Thai isolates TD525A (96.6-99.7%) and TD424 (96.3-99.5%), and very similar to that of the France-Belem strain when compared with other isolates (Sal-1, Sri Lanka, and Colombia). Interallelic recombination was found in the poly-Q repeat and a Sal-1 type amino acid structure was observed in all isolates. This study shows that the MSP gene nucleotide sequence of resurgent P. vivax in Korea is most similar to that of Thai isolates; however, the Korean strains are phylogenetically unique.

Failure to demonstrate Borna disease virus genome in peripheral blood mononuclear cells from psychiatric patients in Korea

RNA, extracted from peripheral blood mononuclear cells (PBMC) obtained from 81 Korean psychiatric patients (39 with schizophrenia, 33 with bipolar affective disorders and nine with major depression), was analyzed for a 391-nucleotide, highly conserved region of the p24 protein-encoding ORF II of Borna disease virus (BDV), using nested reverse transcription-polymerase chain reaction (RT-PCR). BDV genomic RNA was not detected in PBMC from any of the 81 Korean psychiatric patients. These data do not support an etiologic association between BDV infection and neuropsychiatric disorders in humans.

Infection rate of Leptospira interrogans in the field rodent, Apodemus agrarius, in Korea

Leptospirosis has significantly decreased in Korea since 1988, following the leptospiral vaccination programme initiated in 1988. Whether this wholly explains the decreased incidence is uncertain. As an initial step to answer this question, infection rates of Leptospira interrogans in field rodents, Apodemis agrarius, were examined and compared with previous data. Two hundred and twenty-two A. agrarius were captured during October-December 1996. Spirochaetes were isolated from 22 (9.9%) and leptospiral DNA was detected in an additional 6 rodents (12.6%). Subsequent microscopic agglutination tests (MAT) classified all these isolates as L. interrogans serogroup Icterohaemorrhagiae serovar lai. The above data did not significantly differ from previous surveys in 1984-7. There was no significant change of L. interrogans infection in field rodents following the introduction of the vaccination programme in Korea. Further studies are needed to determine the role of human vaccination in reducing incidence.

Slow dendritic transport of dissociated mouse hippocampal neurons exposed to aluminum

We determined the influence of aluminum on dendritic transport, using an in vitro system of dissociated mouse hippocampal neurons. Newly synthesized RNA from dissociated mouse hippocampal neurons was more slowly transported into dendrites in the presence of aluminum chloride when compared to those without the addition of aluminum chloride to the culture medium. Suppression of dendritic transport of newly synthesized RNA may be responsible for the dendritic degeneration observed in aluminum neurotoxicity, eventually leading to neuronal degeneration.

Human T-cell lymphotropic virus type I in Iranian-born Mashhadi Jews: genetic and phylogenetic evidence for common source of infection

High prevalence of human T-cell lymphotropic virus type I (HTLV-I) infection and disease has been identified among Iranian-born Mashhadi Jews, an ethnically segregated, highly inbred population. To determine the origin and genetic diversity of HTLV-I in this group, 1,039 bp spanning selected regions of the HTLV-I gag, pol, env and pX genes were enzymatically amplified and sequenced directly from DNA of five Mashhadi Jews (three with spastic myelopathy and two asymptomatic carriers). Alignment and comparison of these sequences with cosmopolitan and Australo-Melanesian topotypes of HTLV-I indicated that the HTLV-I strains from Mashhadi Jews, which were > or = 99.9% identical among themselves, exhibited considerable sequence similarity (> or = 99%) to HTLV-I strains from southern India, suggesting a common source of infection. Phylogenetic analysis, using the maximum parsimony method, was consistent with a single-source introduction of HTLV-I into the Mashhadi Jewish community.

Sequence and phylogenetic analyses of human T cell lymphotropic virus type 1 from a Brazilian woman with adult T cell leukemia: comparison with virus strains from South America and the Caribbean basin

Human T cell lymphotropic virus type 1 (HTLV-1) is endemic in South America and the Caribbean basin. To clarify the genetic and phylogenetic relationship between an HTLV-1 strain isolated from a Brazilian woman with adult T cell leukemia and viral isolates from elsewhere in South America and from other geographic regions, selected regions of the gag, pol, env, and pX genes were amplified and directly sequenced. The overall sequence similarities between the Brazil-R-1 strain and the Japanese prototype ATK strain were 98.7% based on 1,295 nucleotides and 99.1% based on 429 amino acids. Phylogenetic analysis indicated that strain Brazil-R-1 clustered with other Brazilian and South American HTLV-1 isolates and was more closely related to Caribbean isolates from Martinique and Guadeloupe than to virus strains from other geographic regions. These data suggest a common source of HTLV-1 infection in the Caribbean basin and South America.

Genotyping of human T cell lymphotropic virus type I using Australo-Melanesian topotype-specific oligonucleotide primer-based polymerase chain reaction: insights into viral evolution and dissemination

Sequence variants of human T cell lymphotropic virus type I (HTLV-I), genetically distinct from cosmopolitan strains of HTLV-I from Japan, the Americas, the Caribbean, and Africa, have been discovered among Melanesians in Papua New Guinea and the Solomon Islands and among Australian aboriginals. By using oligonucleotide primer pairs derived from sequences unique to the gp46- and gp21-encoding regions of the env gene of the Melanesian HTLV-I variants, HTLV-I strains from widely separated geographic regions could be grouped into either of two major geographic-specific genotypes or topotypes: Australo-Melanesian and cosmopolitan. These primers did not permit amplification of the corresponding env gene regions in strains of simian T cell lymphotropic virus type I from Asia and Africa. Phylogenetic analysis also supported two distinct lineages, consistent with evolution of HTLV-I in Australia and Melanesia independent from that in other parts of the world.

Genetic evidence for a hantavirus enzootic in deer mice (Peromyscus maniculatus) captured a decade before the recognition of hantavirus pulmonary syndrome

To determine if the emergence of hantavirus pulmonary syndrome in the United States was a consequence of recent amino-acid altering mutations and/or genetic reassortment with pathogenic hantaviruses, we examined lung and spleen tissues from seropositive deer mice trapped in August 1983 in Mono County, California, for hantaviral RNA by reverse transcriptase-directed polymerase chain reaction. Alignment and comparison of 1485 nucleotides of the S and M genomic segments enzymatically amplified from these tissues indicated that these deer mice harbored a hantavirus which was genetically similar, differing by less than 2% at the deduced amino-acid level, to the hantavirus implicated in cases of hantavirus pulmonary syndrome occurring in the Four-Corners region of New Mexico, Arizona, Utah, and Colorado in 1993. The peromyscine rodent-borne hantaviruses were, in turn, genetically distinct from other well-characterized hantaviruses, diverging by approximately 30% from Prospect Hill and Puumala viruses at the nucleotide and amino acid levels. Phylogenetic analysis using the maximum parsimony, neighbor-joining, and unweighted pair-group methods indicated that the Peromyscus-derived hantavirus shared a common ancestry with arvicolid rodent-borne hantaviruses. Overall congruency of the phylogenetic trees based on the S and M genomic sequences supported the evolutionary position of the peromyscine rodent-borne hantaviruses. Our data also establish the existence of a hantavirus enzootic in deer mice long before the recognition of hantavirus pulmonary syndrome in the United States.

Genetic and phylogenetic analyses of human T-cell lymphotropic virus type I variants from Melanesians with and without spastic myelopathy

Molecular variants of human T-cell lymphotropic virus type I (HTLV-I) have been isolated recently from lifelong residents of remote Melanesian populations, including a Solomon Islander with tropical spastic paraparesis/HTLV-I-associated myelopathy (TSP/HAM) or HTLV-I myeloneuropathy. To clarify the genetic heterogeneity and molecular epidemiology of disease-associated strains of HTLV-I, we enzymatically amplified, then directly sequenced representative regions of the gag, pol, env, and pX genes of HTLV-I strains from Melanesians with and without TSP/HAM, and aligned and compared these sequences with those of HTLV-I strains from patients with TSP/HAM or adult T-cell leukemia/lymphoma and from asymptomatic carriers from widely separated and culturally disparate populations. Overall, the HTLV-I variant from the Solomon Islander with TSP/HAM, like HTLV-I strains from asymptomatically infected Melanesians, diverged by approx 7% from cosmopolitan HTLV-I strain. No disease-specific viral sequences were found. Gene phylogenies, as determined by the unweighted pair-group method of assortment and by the maximum parsimony method, indicated that the Melanesian and cosmopolitan strains of HTLV-I have evolved along separate geographically dependent lineages, one comprised of HTLV-I strains from Papua New Guinea and the Solomon Islands, and the other composed of virus strains from Japan, India, the Caribbean, Polynesia, the Americas, and Africa. The total absence of nonhuman primates in Papua New Guinea and the Solomon Islands precludes any possibility that the Melanesian HTLV-I strains have evolved recently from the simian homolog of HTLV-I.

Genetic analysis and molecular phylogeny of simian T-cell lymphotropic virus type I: evidence for independent virus evolution in Asia and Africa

Type C retroviruses, designated simian T-cell lymphotropic virus type I (STLV-I), have been isolated from several genera of Old World monkeys and apes, but not from New World monkeys and prosimians. To determine the genomic diversity and molecular evolution of STLV-I and to clarify their genetic relationship to human T-cell lymphotropic virus type I (HTLV-I), we enzymatically amplified, then directly sequenced selected regions of the gag, pol, env, and pX genes of STLV-I strains from Asia and Africa. STLV-I strains Si-2, Matsu, and JM86 from Japanese macaques, which exhibited sequence similarities ranging from 98.5 to 99.8% among themselves, diverged by 12.9 to 13.3% from STLV-I strain MM39-83 from a naturally infected rhesus macaque, by 9.7 to 11.2% from STLV-I strains from Africa, and by 8.8 to 11.2% from HTLV-I strains originating in Japan, India, Africa, the Caribbean, the Americas, Polynesia, and Melanesia. By contrast, the interspecies nucleotide sequence similarity among African STLV-I strains from green monkey, yellow baboon, sooty mangabey, and common chimpanzee was remarkably high, ranging from 96.9 to 97.4%, and these STLV-I strains diverged by only 2.2 to 2.8% from HTLV-I strain EL from equatorial Zaire. Phylogenetic trees constructed by using the neighbor-joining and maximum parsimony methods indicated that the Asian STLV-I strains diverged from the common ancestral virus prior to African STLV-I and cosmopolitan and Melanesian HTLV-I strains. Thus, our data are consistent with an archaic presence of STLV-I in Asia, probably predating macaque speciation, with subsequent independent virus evolution in Asia and Africa.

Sequence analysis of human T cell lymphotropic virus type I strains from southern India: gene amplification and direct sequencing from whole blood blotted onto filter paper

Human T cell lymphotropic virus type I (HTLV-I) infection in India has been found to be associated with adult T cell leukaemia/lymphoma (ATLL) and HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP) among life-long residents of southern India. To examine the heterogeneity of HTLV-I strains from southern India and to determine their relationship with the sequence variants of HTLV-I from Melanesia, 1149 nucleotides spanning selected regions of the HTLV-I gag, pol, env and pX genes were amplified and directly sequenced from DNA extracted from whole blood blotted onto filter paper and from peripheral blood mononuclear cells, obtained from one patient with HAM/TSP, two with ATLL and eight asymptomatic carriers from Andhra Pradesh, Kerala and Tamil Nadu. Sequence alignments and comparisons indicated that the 11 HTLV-I strains from southern India were 99.2% to 100% identical among themselves and 98.7% to 100% identical to the Japanese prototype HTLV-I ATK. The majority of base substitutions were transitions and silent. No frameshifts, insertions, deletions or possibly disease-specific base changes were found in the regions sequenced. The observed clustering of the Indian HTLV-I strains with those from Japan, as determined by the maximum parsimony method, suggested a common source of HTLV-I infection with subsequent parallel evolution. Amplification of DNA from blood specimens collected on filter paper may be useful for the study of other blood-borne pathogens.