Influences of ethanol and temperature on sucrose-evoked response of gustatory neurons in the hamster solitary nucleus

Taste-responsive neurons in the nucleus of the solitary tract (NST), the first gustatory nucleus, often respond to thermal or mechanical stimulation. Alcohol, not a typical taste modality, is a rewarding stimulus. In this study, we aimed to investigate the effects of ethanol (EtOH) and/or temperature as stimuli to the tongue on the activity of taste-responsive neurons in hamster NST. In the first set of experiments, we recorded the activity of 113 gustatory NST neurons in urethane-anesthetized hamsters and evaluated responses to four basic taste stimuli, 25% EtOH, and 40°C and 4°C distilled water (dH₂O). Sixty cells responded to 25% EtOH, with most of them also being sucrose sensitive. The response to 25% EtOH was significantly correlated with the sucrose-evoked response. A significant correlation was also observed between sucrose- and 40°C dH₂O- and between 25% EtOH- and 40°C dH₂O-evoked firings. In a subset of the cells, we evaluated neuronal activities in response to a series of EtOH concentrations, alone and in combination with 32 mM sucrose (EtOH/Suc) at room temperature (RT, 22°C–23°C), 40°C, and 4°C. Neuronal responses to EtOH at RT and 40°C increased as the concentrations increased. The firing rates to EtOH/Suc were greater than those to EtOH or sucrose alone. The responses were enhanced when solutions were applied at 40°C but diminished at 4°C. In summary, EtOH activates most sucrose-responsive NST gustatory cells, and the concomitant presence of sucrose or warm temperatures enhance this response. Our findings may contribute to elucidate the neural mechanisms underlying appetitive alcohol consumption.

Efficacy and safety of combination therapy with SGLT2 and DPP4 inhibitors in the treatment of type 2 diabetes: A systematic review and meta-analysis

BACKGROUND

This review evaluated the efficacy and safety of a combination therapy comprising a sodium-glucose cotransporter type 2 inhibitor (SGLT2i) and dipeptidyl peptidase-4 inhibitor (DPP4i) in type 2 diabetes.

METHODS

A literature search through to May 2017 was carried out of PubMed, Embase and the Cochrane Central Register of Controlled Trials. Studies were eligible if they were randomized controlled trials (RCTs) comparing SGLT2i plus DPP4i (SGLT2i/DPP4i) against DPP4i±placebo or SGLT2i±placebo and published in English. The primary outcome was change in HbA_1c from baseline.

RESULTS

Eight RCTs comparing SGLT2i/DPP4i and DPP4i, and five RCTs comparing SGLT2i/DPP4i and SGLT2i, with three RCTs involving both comparisons, were included in the present review. SGLT2i/DPP4i resulted in a greater mean HbA_1c reduction [weighted mean difference (WMD]): -0.62%] than did DPP4i alone, which was a much less marked reduction (WMD: -0.35%) than with SGLT2i alone. Also, significant differences in body weight loss from baseline were observed only with SGLT2i/DPP4i vs. DPP4i, but not vs. SGLT2i. The risk of hypoglycaemic events was low and similar between treatment groups. When subjects were stratified based on baseline HbA_1c, any reduction by SGLT2i/DPP4i in relation to DPP4i was proportional to baseline HbA_1c levels. However, compared with SGLT2i, HbA_1c reductions with SGLT2i/DPP4i were modest regardless of baseline HbA_1c.

CONCLUSION

Combination therapy with SGLT2i and DPP4i is both efficacious and safe. In particular, a marked additional glucose-lowering effect is evident when SGLT2i is combined with or added to DPP4i, and not vice versa. However, baseline HbA_1c determined the additional glucose-lowering effects of SGLT2i in combined treatment with DPP4i.

The 100 Most-Cited Articles Focused on Ultrasound Imaging: A Bibliometric Analysis

Purpose The number of citations that an article has received reflects its impact on a particular research area. The aim of this study was to identify the 100 most-cited articles focused on ultrasound (US) imaging and to analyze the characteristics of these articles. Methods We determined the 100 most-cited articles on US imaging via the Web of Science database, using the search term. The following parameters were used to analyze the characteristics of the 100 most-cited articles: publication year, journal, journal impact factor, number of citations and annual citations, authors, department, institution, country, type of article, and topic. Results The number of citations for the 100 most-cited articles ranged from 1849 to 341 (median: 442.0) and the number of annual citations ranged from 108.0 to 8.1 (median: 22.1). The majority of articles were published in 1990 - 1999 (39 %), published in radiology journals (20 %), originated in the United States (45 %), were clinical observation studies (67 %), and dealt with the vessels (35 %). The Department of Internal Medicine at the University of California and the Research Institute of Public Health at the University of Kuopio (n = 4 each) were the leading institutions and Salonen JT and Salonen R (n = 4 each) were the most prolific authors. Conclusion Our study presents a detailed list and analysis of the 100 most-cited US articles, which provides a unique insight into the historical development in this field.

Percutaneous radiofrequency ablation for symptomatic uterine leiomyomas: a systematic review and meta-analysis

PURPOSE

To evaluate the efficacy and safety of percutaneous radiofrequency ablation (RFA) in the treatment of uterine leiomyomas.

MATERIALS AND METHODS

Medline, Embase, and Cochrane databases were searched through August 2014 for all relevant studies on RFA for uterine leiomyomas. The efficacy and safety of RFA were assessed using the outcome measures of tumor volume, symptom severity score, health-related quality of life (HRQL) score, procedure-related complications, and reintervention. The authors calculated pooled event rates with 95% confidence intervals using random-effects model to assess the effects of RFA.

RESULTS

Eight observational studies were identified as eligible for inclusion in this meta-analysis and included 370 patients. All analyzed outcomes showed statistically significant improvements from baseline to final follow-up. Twenty-seven complications were identified and five of them qualified as major complications. Five patients required reintervention after RFA.

CONCLUSIONS

Percutaneous RFA is an effective and safe treatment for patients with uterine leiomyomas.

EFFECTS OF RESISTANCE EXERCISES AND COMPLEX DECONGESTIVE THERAPY ON ARM FUNCTION AND MUSCULAR STRENGTH IN BREAST CANCER RELATED LYMPHEDEMA

The incorporation of resistance exercises into the lifestyle of patients with lymphedema is understudied and an emerging interest. We investigated the effectiveness and results of adding a moderate intensity resistance exercise program for 8 weeks in conjunction with intensive CDT for 1 or 2 weeks (depending on severity) on arm volume, arm function, QOL, and muscular strength in patients with breast cancer-related lymphedema. This prospective, pilot trial included forty-four patients with a history of breast cancer who were beginning complex decongestive therapy for lymphedema. They were assigned to either the intervention (n = 22) or control (n = 22). groups. The intervention comprised of resis- tance band exercises 5 times a week for 8 weeks. These were initially supervised during the intensive lymphedema treatment, but performed independently during the study period. Limb volume, muscular strength, and the European Organization for Research and Treatment of Cancer QOL Questionnaire C30 (EORTC QLQ-C30), EORTC-Breast Cancer-Specific QOL Questionnaire (EORTC QLQ-BR23), and Disabilities of Arm, Shoulder, and Hand (DASH) questionnaires were assessed at baseline and at 8 weeks. After 8 weeks, the intervention group demonstrated statistically significant differences (p < 0.05) in the DASH score and muscular strength compared to the control group. Our results indicate that upper body resistance exercise demonstrates a positive effect on arm function and muscular strength without increasing arm volume in breast cancer related lymphedema during and shortly post intensive CDT lymphedema treatment.

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

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

Clinical characteristics predicting early clinical failure after 72 h of antibiotic treatment in women with community-onset acute pyelonephritis: a prospective multicentre study

In patients with community-onset acute pyelonephritis (CO-APN), assessing the risk factors for poor clinical response after 72 h of antibiotic treatment (early clinical failure) is important. The objectives of this study were to define those risk factors, and to assess whether early clinical failure influences mortality and treatment outcomes. We prospectively collected the clinical and microbiological data of women with CO-APN in South Korea from March 2010 to February 2012. The numbers of cases in the early clinical success and early clinical failure groups were 840 (79.1%) and 222 (20.9%), respectively. Final clinical failure and mortality were higher in the early clinical failure group than in the early clinical success group (14.9% vs 2.3%, p <0.001; 6.8% vs 0.1%, p 0.001, respectively). In a multiple logistic regression model, the risk factors for early clinical failure among the total 1062 patients were diabetes mellitus (OR 1.5; 95% CI 1.1-2.1), chronic liver diseases (OR 3.3; 95% CI 1.6-6.7), malignancy (OR 2.2; 95% CI 1.1-4.4), Pitt score ≥2 (OR 2.5; 95% CI 1.6-3.8), presence of azotaemia (OR 1.8; 95% CI 1.2-2.7), white blood cell count ≥20 000/mm(3) (OR 2.5; 95% CI 1.6-4.0), serum C-reactive protein level ≥20 mg/dL (OR 1.7; 95% CI 1.2-2.4), and history of antibiotic usage within the previous year (OR 1.5; 95% CI 1.1-2.2). Analysing the subgroup of 743 patients with CO-APN due to Enterobacteriaceae, fluoroquinolone resistance of the uropathogen was another factor associated with early clinical failure (OR 1.7; 95% CI 1.1-2.5). Simple variables of underlying diseases, previous antibiotic usage and initial laboratory test outcomes can be used to decide on the direction of treatment in CO-APN.

Clinical characteristics of community-acquired acute pyelonephritis caused by ESBL-producing pathogens in South Korea

OBJECTIVES

The aim of this study was to determine the risk factors and clinical characteristics of community-acquired acute pyelonephritis (CA-APN) caused by extended-spectrum β-lactamase (ESBL)-producing organisms.

METHODS

From March 2010 to February 2011, patients with CA-APN were recruited in 11 hospitals in South Korea. Clinical and microbiological data were collected prospectively, and the ESBLs and multilocus sequence types of the ESBL-producing Escherichia coli were characterized. Comparison between CA-APN caused by ESBL-producing Enterobacteriaceae and those by non-ESBL-producing organisms was performed.

RESULTS

A total of 566 patients were recruited. Enterobacteriaceae were detected in 526 patients. Forty-six isolates (46/526, 8.7 %) were positive for ESBLs. Clinical and microbiological failure did not differ between the two groups, despite there being fewer patients with ESBL-positive isolates provided with appropriate antibiotics initially (19.6 vs. 93.8 %, p < 0.001). However, the duration of hospitalization was longer in the ESBL group (10.5 vs. 7.0 days, p = 0.012). In a logistic regression model, Charlson score ≥1 point [odds ratio (OR) 3.4, 95 % confidence interval (CI) 1.6-7.0, p = 0.001], antibiotics usage during the previous year (OR 3.1, 95 % CI 1.4-7.2, p = 0.008), and urinary catheterization during the previous month (OR 4.4, 95 % CI 1.1-17.6, p = 0.035) were associated with the risks of CA-APN by ESBL producers. CTX-M-15 (48 %) and CTX-M-14 (38 %) were the most common ESBLs. ST131 was the most common clone (7/24, 29.1 %), which was more frequently resistant to cefepime, fosfomycin, and temocillin.

CONCLUSIONS

The risk factors for CA-APN by ESBL producers were Charlson score ≥1 point, antibiotics usage during the previous year, and urinary catheterization during the previous month.

Comparison of bolus transit patterns identified by esophageal impedance to barium esophagram in patients with dysphagia

Bolus transit through the esophagus has not been validated by videoesophagram in patients with dysphagia and changes in impedance with abnormal barium transit have not been described in those patients. The aim of this study was to compare esophageal impedance findings with barium esophagram measurements in patients with dysphagia. The consecutive patients with dysphagia underwent conventional multichannel esophageal impedance manometry, after which a barium videoesophagram was performed simultaneously with multichannel esophageal impedance manometry using a mean of three swallows of barium. Esophageal emptying patterns shown in the esophagogram were classified by the degree of intraesophageal stasis and presence of intraesophageal reflux. Bolus transit patterns in impedance were classified as complete and incomplete transit. Sixteen patients (M : F = 8 : 8, mean age, 47 years) were enrolled. Their manometric diagnosis were normal (n= 6), ineffective esophageal motility (n= 1), diffuse esophageal spasm (DES; n= 2), and achalasia (n= 7). Sixty-three swallows were analyzed. According to impedance analysis, 21/22 swallows with normal barium emptying showed complete transit (96%) and 31/32 swallows with severe stasis showed incomplete transit (97%). Nine swallows with mild stasis showed either complete or incomplete transit patterns in impedance. Swallows with mild barium stasis and complete transit in impedance were observed in patients who had received treatment (two patients with achalasia with history of esophageal balloonplasty and a patient with DES after nifedipine administration). Impedance reflected severe stasis with retrograde barium movement and described typical bolus transit patterns in patients with achalasia and DES. In conclusion, impedance-barium esophagram concordance is high for swallows with normal esophageal emptying and for severe barium stasis in patients with dysphagia.

Impact of non-alcoholic fatty liver disease on microalbuminuria in patients with prediabetes and diabetes

BACKGROUND

It is unknown whether microalbuminuria is associated with non-alcoholic fatty liver disease (NAFLD) among patients with prediabetes and type 2 diabetes mellitus (DM). This study investigated the association of NAFLD with microalbuminuria among patients with prediabetes and diabetes.

METHODS

We evaluated 1361 subjects who had an abnormal oral glucose tolerance test (OGTT) on routine screening. All participants were divided into two groups, prediabetes and newly diagnosed type 2 DM, and the association of NAFLD with metabolic parameters on microalbuminuria was analysed.

RESULTS

The patients with NAFLD had higher prevalence rates of microalbuminuria (6.3% vs 19%; P = 0.001 in prediabetes, 4.5% vs 32.6%; P < 0.001 in diabetes) and also had a greater albumin-to-creatinine ratio (14.6 +/- 52.0 microg/mg Cr vs 27.7 +/- 63.9 microg/mg Cr; P = 0.051 in prediabetes, 11.4 +/- 21.4 microg/mg Cr vs 44.7 +/- 76.4 microg/mg Cr; P < 0.001 in diabetes) than those without NAFLD. The logistic regression analysis showed that NAFLD was associated with increased rates of microalbuminuria (odds ratio 3.66; 95%confidence interval (CI) 1.31-10.20, P = 0.013 in prediabetes, odds ratio 5.47;95% CI 1.01-29.61, P = 0.048 in diabetes), independently of age, sex, body mass index, waist circumference, liver enzymes, lipid profiles, HbA1c, insulin resistance as estimated by homeostasis model assessment, hypertension,smoking status and the metabolic syndrome.

CONCLUSIONS

The results of our study revealed a strong relationship between microalbuminuria and NAFLD in the patients with prediabetes and newly diagnosed diabetes. Further studies are required to confirm whether NAFLD is a predictor of the development of microalbuminuria in patients with prediabetes and diabetes.

Pitfalls in the radiological and pathological correlation of tumour response rates of hepatocellular carcinoma following radiofrequency ablation

According to the American Association for the Study of Liver Diseases (AASLD) guidelines, radiofrequency ablation (RFA) is a safe and effective treatment for patients with unresectable hepatocellular carcinoma (HCC). In most studies, the initial complete tumour response rates of small HCCs < or =3 cm following RFA have been reported as more than 90% or 95%, and local tumour progression rates have been reported as approximately 10% or 20%. Notwithstanding these promising clinical outcomes, the complete tumour response rates for HCC following RFA as determined by conventional histopathological diagnostic criteria have been reported to be less than 50% in many recent reports. While considering that most cases of local tumour progression of HCC are known to occur within two years following RFA, it may not be reasonable to assume that clinical and radiological examinations have significantly overestimated the tumour response rates. On the contrary, it is likely that the conventional histopathological examination techniques may have underestimated the tumour response rates. The apparent discrepancy between the histopathological and the radiological tumour response of radiofrequency ablation for hepatocellular carcinomas can be attributed to several histological features, such as thermal fixation or apoptosis, that were not included in the conventional histopathological diagnostic criteria. However, a robust conclusion cannot be derived because of lack of adequate controlled studies, and further well designed prospective multicentre trials will be helpful to solve this issue.

Immobilization of glucoamylase and glucose oxidase in activated carbon: effects of particle size and immobilization conditions on enzyme activity and effectiveness

Glucoamylase and glucose oxidase have been immobilized on carbodiimide-treated activated carbon particles of various sizes. Loading data indicate nonuniform distribution of immobilized enzyme within the porous support particles. Catalysts with different enzyme loading and overall activities have been prepared by varying enzyme concentration in the immobilizing solution. Analysis of these results by a new method based entirely upon experimentally observable catalyst properties indicates that intrinsic catalytic activity is reduced by immobilization of both enzymes. Immobilized glucoamylase intrinsic activity decreases with increasing enzyme loading, and similar behavior is suggested by immobilized glucose oxidase data analysis. The overall activity data interpretation method should prove useful in other immobilized enzyme characterization research, especially in situations where the intraparticle distribution of immobilized enzyme is nonuniform and unknown.

Type II and III Taste Bud Cells Preferentially Expressed Kainate Glutamate Receptors in Rats

Glutamate-induced cobalt uptake reveals that non-NMDA glutamate receptors (GluRs) are present in rat taste bud cells. Previous studies involving glutamate induced cobalt staining suggest this uptake mainly occurs via kainate type GluRs. It is not known which of the 4 types of taste bud cells express subunits of kainate GluR. Circumvallate and foliate papillae of Sprague-Dawley rats (45~60 days old) were used to search for the mRNAs of subunits of non-NMDA GluRs using RT-PCR with specific primers for GluR1-7, KA1 and KA2. We also performed RT-PCR for GluR5, KA1, PLCbeta2, and NCAM/SNAP 25 in isolated single cells from taste buds. Taste epithelium, including circumvallate or foliate papilla, express mRNAs of GluR5 and KA1. However, non-taste tongue epithelium expresses no subunits of non-NMDA GluRs. Isolated single cell RT-PCR reveals that the mRNAs of GluR5 and KA1 are preferentially expressed in Type II and Type III cells over Type I cells.

Change of insulin sensitivity in hepatitis C patients with normal insulin sensitivity: a 5-year prospective follow-up study variation of insulin sensitivity in HCV patients

BACKGROUND

Hepatitis C virus (HCV) infection is associated with a high prevalence of diabetes mellitus (DM). Insulin resistance (IR) is known to play a crucial role in the development of DM in chronic hepatitis C (CHC) patients. We prospectively investigated changes of insulin sensitivity in CHC patients during a 5-year period and analysed the factors significantly associated with IR.

METHODS

Sixty-two CHC patients with normal insulin sensitivity (CHC group), and a healthy control group of 172 subjects matched by age, gender, body mass index and lifestyles were studied. We compared the initial baseline insulin sensitivity, metabolic parameters and incidence of IR at the end of the follow-up period between the two groups. The changes in insulin sensitivity, metabolic parameters and the development of IR were analysed as well as factors associated with the development of IR.

RESULTS

IR developed in 22.5% of 62 CHC patients and 5.2% of 172 normal individuals (P < 0.001). HCV infection per se and the genotype 1 were independent risk factors for the development of IR. The duration of infection > or = 120 months, initial fasting glucose 90-100 mg/dL, fasting insulin > or = 10 microIU/mL and the homeostasis model assessment (HOMA-IR) 2.3-2.7 were significantly associated with the development of IR in the CHC group.

CONCLUSION

HCV infection was an independent risk factor for the development of IR. All CHC patients, even those with normal insulin sensitivity, require careful monitoring for the development of IR.

Successful transcatheter closure of a large patent ductus venosus with the Amplatzer vascular plug II

Patent ductus venosus is a rare form of congenital portosystemic shunt from the fetal umbilical vein to the inferior vena cava. The reported surgical treatments include ligation, banding, and liver transplantation. In addition, transcatheter closure with a coil, stent, or original Amplatzer vascular plug (AVP) has been reported. The AVP II, a redesigned version of the original vascular plug with a finer more densely woven nitinol wire and a large diameter (up to 22 mm) is available. This reported case is the first successful occlusion of a large patent ductus venosus with the new AVP II.

Local recurrence after curative resection in patients with colon and rectal cancers

BACKGROUND AND AIMS

There are a range of rates and a number of prognostic factors associated with the local recurrence of colorectal cancer after curative resection. The aim of this study was to identify the potential prognostic factors of local recurrence in patients with colon and rectal cancers.

MATERIALS AND METHODS

A retrospective review of 1,838 patients who underwent curative resection of non-metastatic colorectal cancer was conducted. The patients were treated between 1994 and 2004, and had a minimum follow-up of 3 years.

RESULTS

There were 994 patients with colon cancer and 844 patients with rectal cancer. The median duration of follow-up was 60.9 +/- 24.5 months. With respect to colon cancer, the local recurrence rate was 6.1% (61 patients). With respect to rectal cancer, 95 patients had a local recurrence (11.3%), the rate of which was statistically greater than the local recurrence rate for colon cancer (p < 0.001). The overall recurrence rate was 16.4% (301 patients), and the local recurrence rate, with or without systemic metastases, was 8.5% (156 patients). Local recurrences occurred within 2 and 3 years in 59.9% and 82.4% of the patients, respectively. In patients with colon and rectal cancer, the pathologic T stage (p = 0.044 and p = 0.034, respectively), pathologic N stage (p = 0.001 and p < 0.001, respectively), and lymphovascular invasion (p = 0.013 and p = 0.004, respectively) were adverse risk factors for local recurrence. The level of the anastomosis from the anal verge was an additional prognostic factor (p = 0.007) in patients with rectal cancer.

CONCLUSION

Compulsive follow-up care of patients with colon and rectal cancers is needed for 3 years after curative resection, especially in patients who have adverse risk factors for local recurrence.

Development of a solar-powered microbial fuel cell

AIMS

To understand factors that impact solar-powered electricity generation by Rhodobacter sphaeroides in a single-chamber microbial fuel cell (MFC).

METHODS AND RESULTS

The MFC used submerged platinum-coated carbon paper anodes and cathodes of the same material, in contact with atmospheric oxygen. Power was measured by monitoring voltage drop across an external resistance. Biohydrogen production and in situ hydrogen oxidation were identified as the main mechanisms for electron transfer to the MFC circuit. The nitrogen source affected MFC performance, with glutamate and nitrate-enhancing power production over ammonium.

CONCLUSIONS

Power generation depended on the nature of the nitrogen source and on the availability of light. With light, the maximum point power density was 790 mW m(-2) (2.9 W m(-3)). In the dark, power output was less than 0.5 mW m(-2) (0.008 W m(-3)). Also, sustainable electrochemical activity was possible in cultures that did not receive a nitrogen source.

SIGNIFICANCE AND IMPACT OF THE STUDY

We show conditions at which solar energy can serve as an alternative energy source for MFC operation. Power densities obtained with these one-chamber solar-driven MFC were comparable with densities reported in nonphotosynthetic MFC and sustainable for longer times than with previous work on two-chamber systems using photosynthetic bacteria.

Quality and effect of single dose versus split dose of polyethylene glycol bowel preparation for early-morning colonoscopy

BACKGROUND AND STUDY AIMS

The conventional procedure of ingestion of an entire dose of polyethylene glycol solution on the day before early-morning colonoscopy may result in poor bowel preparation. The aim of this study was to evaluate the efficacy and effect of a split-dose ingestion of polyethylene glycol for early-morning colonoscopy.

METHODS

A total of 303 age- and sex-matched consecutive individuals presenting for medical check-ups were randomly assigned to receive either 4 L of polyethylene glycol solution with a soft diet on the day before colonoscopy (n = 152; group A), or 3 L of polyethylene glycol solution with a soft diet on the preceding day and then 1 L of the solution on the day of colonoscopy (n = 151; group B). The quality of bowel preparation was evaluated using the Ottawa scale, and the time to cecal intubation and the technical difficulty during the procedure were also recorded.

RESULTS

There was no difference in compliance between group A (single-dose) and group B (split-dose). The quality of bowel preparation was better in group B compared with group A. When the participants were categorized according to compliance (good compliance, 116 in group A, 119 in group B; poor compliance, 36 in group A, 32 in group B), the quality of the bowel preparation had a higher score in the good compliance compared with the poor compliance group, and in group B this difference was usually significant.

CONCLUSIONS

Split-dose bowel preparation with polyethylene glycol solution provided a better quality preparation than the conventional method for patients undergoing early-morning colonoscopy.

Molecular epidemiologic study of a human immunodeficiency virus 1 outbreak in haemophiliacs B infected through clotting factor 9 after 1990

BACKGROUND AND OBJECTIVES

Twenty haemophiliacs were diagnosed as infected with human immunodeficiency virus 1 (HIV-1), 1 to 2 years after exposure to clotting factor 9 manufactured in Korea, beginning in early 1990. This study assessed the genetic relationships between viruses found in plasma donors and haemophiliacs.

MATERIALS AND METHODS

Sequencing of the nef and pol genes of viruses from infected haemophiliacs, plasma donors whose plasma was used in domestic clotting factor manufacture, haemophiliacs infected outside Korea, and local controls were determined by nested polymerase chain reactions and direct DNA sequencing. Phylogenetic analysis was used to investigate the relationships among the sequences.

RESULTS

Both plasma donors and the haemophiliacs were infected with a subclade of subtype B that is a founder effect lineage in Korea.

CONCLUSION

Our data indicate that HIV-1 transmission to 20 haemophiliacs occurred through intravenous injection of Korean-made clotting factor.

SUMMARY

A clotting factor made in Korea from blood from cash-paid donors infected at least 20 haemophiliacs with HIV-1 subtype B.

Gene amplification and protein overexpression of HER-2/neu in human extrahepatic cholangiocarcinoma as detected by chromogenic in situ hybridization and immunohistochemistry: its prognostic implication in node-positive patients

BACKGROUND

In cholangiocarcinoma (CC), HER-2/neu protein overexpression has rarely been reported and the results are conflicting. The present study aimed to clarify the rates of HER-2/neu protein overexpression and gene amplification in human extrahepatic CC and to evaluate the correlation between HER-2/neu and several clinicopathologic features.

PATIENTS AND METHODS

We investigated HER-2 gene amplification by chromogenic in situ hybridization (CISH) and HER-2/neu protein overexpression by immunohistochemistry in 55 extrahepatic CC patients who underwent curative surgery at our institution.

RESULTS

Overexpression of HER-2/neu protein (staining intensity score > or = 2) was found in 16 out of 55 patients (29.1%). CISH revealed that HER-2 gene signals were increased in 10 out of 55 patients (18.1%). There was a positive and significant correlation between HER-2 gene amplification and HER-2/neu protein overexpression (Spearman's rho = 0.718, P < 0.01). In subgroup with lymph node metastases, HER-2 gene amplification by CISH was significant prognostic factor for survival (OR 43.6, 95% confidence interval 1.6-1219.6).

CONCLUSIONS

HER-2/neu protein overexpression by HER-2 gene amplification may occur in human extrahepatic CC and constitute an independent prognostic factor in patients with lymph node metastases. In subgroup with lymph node metastases who exhibit HER-2/neu overexpression might constitute potential candidates for new adjuvant therapy, such as humanized monoclonal antibodies.

Serotonin transporter gene polymorphism and irritable bowel syndrome

Polymorphisms in the promoter region of the serotonin reuptake transporter (SERT) gene may underlie the disturbance in gut function in patients with irritable bowel syndrome (IBS). Association studies of SERT polymorphisms and IBS have shown diverse results among different countries, which might be due to racial and subject composition differences. The aim of this study was to assess the potential association between SERT polymorphisms and IBS in Koreans. A total of 190 IBS patients, who met the Rome II criteria, and 437 healthy controls were subjected to genotyping. SERT polymorphisms differed in the IBS and control groups (P = 0.014). The SERT deletion/deletion genotype occurred with greater frequency in the diarrhoea-predominant IBS group than in the controls. A strong genotypic association was observed between the SERT deletion/deletion genotype and diarrhoea-predominant IBS (P = 0.012). None of the clinical symptoms analysed was significantly associated with the SERT genotypes. The frequency of the SERT insertion/insertion genotype was much lower than that of the other two genotypes. A significant association was observed between the SERT polymorphism and IBS, especially diarrhoea-predominant IBS, suggesting that the SERT gene is a potential candidate gene involved in IBS in Korea.

Multicentre, parallel group, randomised, single-blind study of the safety and efficacy of atosiban versus ritodrine in the treatment of acute preterm labour in Korean women

OBJECTIVE

To compare the efficacy and safety of atosiban with those of ritodrine in preterm labour.

DESIGN

Multicentre, single-blind, randomised, controlled trial.

SETTING

Obstetric units in six referral centres in Korea.

POPULATION

Women with singleton pregnancies with preterm labour, between 24 and 33 + 6 weeks of gestation.

METHODS

One hundred and twenty-eight women were randomised to receive intravenous atosiban (n= 63) or ritodrine (n= 65) and were stratified by gestational age (<28 weeks and >or=28 weeks). Atosiban or ritodrine was administered for up to 48 hours. Progression of labour was assessed by the frequency of contractions and cervical dilatation and effacement. Alternative tocolysis could be given as rescue therapy.

MAIN OUTCOME MEASURE

Efficacy was assessed as the proportion of women in each group who did not deliver and did not need alternative tocolytic therapy at 48 hours and 7 days after therapy initiation. Safety was assessed as the numbers of maternal adverse events and neonatal morbidity.

RESULTS

Tocolytic efficacy after 7 days was significantly better in the atosiban group than in the ritodrine group (60.3 versus 34.9%), but not at 48 hours (68.3 versus 58.7%). Maternal adverse events related to therapy were reported less frequently in the atosiban group (7.9 vs 70.8%; P= 0.0001), resulting in fewer early drug terminations due to adverse events (0 versus 20.0%; P= 0.0001). This, however, was not accompanied by a concurrent improvement in perinatal outcomes.

CONCLUSION

The efficacy and safety of atosiban in the treatment of preterm labour were superior to those of ritodrine.

Clinical features associated with improvement of fatty liver disease

BACKGROUND

We presumed that identification of the factors associated with improvement of fatty livers disease (FLD) would support the therapeutic options for FLD. The goal of this study was to clarify what clinical characteristics are associated with biochemical and sonographic improvements in the non-alcoholic population with fatty livers.

METHODS

A total of 615 non-alcoholic men had elevated alanine aminotransferase (ALT) (> or = 40 IU/L) levels and sonographic evidence of a fatty liver, and their clinical characteristics were assessed at the beginning of the study and after 1 year of follow up. The improvement was defined as combination of normal ALT level and negative sonography for hepatic fat after 1 year. Programmed intervention or medications were not applied in this study population.

RESULTS

The overall rate of improvement of FLD after a 1-year follow up was 37/615 (6.0%). The improvement was strongly associated with decrement of changes in bodyweight, body mass index, waist circumference, gamma-glutamyltransferase, fasting blood sugar, total cholesterol, triglycerides, low-density lipoprotein cholesterol, total cholesterol/high-density lipoprotein cholesterol ratio and homeostasis model assessment. Multivariate analysis showed that decrement of changes in bodyweight (odds ratio (OR) = 1.56; 95% confidence interval (95%CI): 1.27-1.92) per 1 kg, body mass index (OR = 2.42; 95%CI: 1.58-3.71) per 1 SD (0.8 kg/m2), waist circumference (OR = 2.13; 95%CI: 1.02-4.54) per 1 cm, and low-density lipoprotein cholesterol (OR = 1.64; 95%CI: 1.05-2.56) per 1 SD (22 mg/dL) were all independent predictors for improvement of FLD.

CONCLUSIONS

These results suggest that the reduction of bodyweight is a major key point for the improvement of FLD.

Novel action of gastric proton pump inhibitor on suppression of Helicobacter pylori induced angiogenesis

BACKGROUND

Although activation of mitogen activated protein kinases (MAPKs) by Helicobacter pylori infection is associated with induction of host angiogenesis, which may contribute to H pylori associated gastric carcinogenesis, the strategy for its prevention has not been identified. As we previously reported a strong inhibitory action of gastric proton pump inhibitors (PPIs) on MAPK extracellular signal regulated kinase (ERK)1/2 phosphorylation, we investigated whether PPIs could suppress the H pylori induced angiogenesis via inhibition of MAPK ERK1/2.

METHODS

To address the relationship between H pylori infection and angiogenesis, comparative analysis of density of CD34(+) blood vessel was performed in tissues obtained from 20 H pylori positive gastritis and 18 H pylori negative gastritis patients. Expression of hypoxia inducible factor 1 (HIF-1alpha) and vascular endothelial growth factor (VEGF) was tested by reverse transcription-polymerase chain reaction and secretion of interleukin 8, and VEGF was measured by ELISA. To evaluate the direct effect of H pylori infection on the tubular formation of human umbilical vein endothelial cells (HUVEC), an in vitro angiogenesis assay was employed. Activation of MAPK and nuclear factor kappaB (NFkappaB) was detected by immunoblotting.

RESULTS

H pylori positive gastritis patients showed a higher density of CD34(+) blood vessels (mean 40.9 (SEM 4.4)) than H pylori negative gastritis patients (7.2+/-0.8), which was well correlated with expression of HIF-1alpha. Conditioned media from H pylori infected gastric epithelial cells directly induced tubular formation of HUVEC and the increase of in vitro angiogenesis was suppressed by PPI treatment. Infection of H pylori significantly upregulated expression of HIF-1alpha and VEGF in gastric epithelial cells and expression of proangiogenic factors was mediated by MAPK activation and partially responsible for NFkappaB activation. PPIs effectively inhibited the phosphorylation of MAPK ERK1/2 that is a principal signal for H pylori induced angiogenesis.

CONCLUSIONS

The fact that PPIs could downregulate H pylori induced angiogenesis indicates that antiangiogenic treatment using a PPI could be a promising protective therapeutic approach for H pylori associated carcinogenesis.

Pretreatment of sludge with microwaves for pathogen destruction and improved anaerobic digestion performance

A new way of generating Class A sludge using microwaves was evaluated through a series of laboratory-scale experiments. Microwaves provide rapid and uniform heating throughout the material. Other benefits of microwave treatment include instant and accurate control and selective and concentrated heating on materials, such as sludge, that have a high dielectric loss factor. Sludge was irradiated with 2450-MHz microwaves, and fecal coliforms were counted. Fecal coliforms were not detected at 65 degrees C for primary sludge and anaerobic digester sludge and at 85 degrees C for waste activated sludge when sludge was irradiated with 2450-MHz microwaves. During the bench-scale anaerobic digester operation, the highest average log reduction of fecal coliforms was achieved by the anaerobic digester fed with microwave-pretreated sludge (> or = 2.66 log removal). The anaerobic digester fed with microwave-irradiated sludge was more efficient in inactivation of fecal coliforms than the other two digesters fed with raw sludge and externally heated sludge, respectively. It took more than three hydraulic retention times for a bench-scale mesophilic anaerobic digester to meet Class A sludge requirements after feeding microwave-irradiated sludge. Class A sludge can be produced consistently with a continuously fed mesophilic anaerobic digester if sludge is pretreated with microwaves to reach 65 degrees C.

Preclinical application of radioimmunoguided surgery using anti-carcinoembryonic antigen biparatopic antibody in the colon cancer

Radioimmunoguided surgery (RIGS) has been known as a sophisticated tool to detect micrometastasis intraoperatively. A preclinical model of RIGS was designed to test the possible clinical applicability of the biparatopic antibody in detecting colorectal cancer. The biparatopic antibody was constructed using two anti-carcinoembryonic antigen (CEA)-specific antibodies, T84.66 and PR1A3, reacting against two different epitopes. (125)I-labeled biparatopic antibody was introduced via the principal colonic arteries at the end of operation in 10 operable patients with colon cancer. After 24 h, the radioactivities of the tumors and lymph nodes were counted using the gamma-detecting probe. The radioactivity count was performed ex vivo. The accurate detection in the primary tumors and metastatic lymph nodes were 100 and 88.7% respectively. False-positive detections occurred in 24 of 256 lymph nodes (9.4%), whereas false-negative detections occurred in 5 of them (2%). The most frequent cause of false-positive detection was dissociated radionuclides trapped in the lymphatic tissues. False-negative detections occurred mainly from weak targeting by radiolabeled antibody, probably due to weak expression of tumor CEA. Conclusively, as most detection errors appear to be reduced within 3 days in vivo, the biparatopic antibody can efficiently be applied to the clinical RIGS, thereby facilitating accurate detection and removal of occult cancer foci in colorectal cancer.

Glutamate-induced cobalt uptake elicited by kainate receptors in rat taste bud cells

Glutamate-induced cobalt uptake reveals non-N-methyl-D-aspartate (non-NMDA) glutamate receptors (GluRs) in rat taste bud cells. However, it is not known which type of non-NMDA glutamate receptors is involved. We used a cobalt staining technique combined with pharmacological tests for kainate or alpha-amino-3-hydroxy-5-methyl-isoxazole-propionic acid (AMPA) receptors and/or immunohistochemistry against subunits of GluRs to examine the presence of non-NMDA receptors in rat foliate tastebud cells. Cobalt uptake into taste cells was elicited by treating taste buds with glutamate, kainate or SYM 2081, a kainate receptor agonist. Treating taste buds with AMPA or fluorowillardiine did not stimulate significant cobalt uptake. Moreover, 6-cyano-7-nitro-quinoxaline-2, 3-dione significantly reduced cobalt staining elicited by glutamate or kainate receptor agonists, but SYM 2206, an AMPA receptor antagonist, did not. Immunohistochemistry against subunits of GluRs reveals GluR6 and KA1-like immunoreactivity. Moreover, most glutamate-induced cobalt-stained cells showed GluR6 and KA1-like immunoreactivity. These results suggest that glutamate-induced cobalt uptake in taste cells occurs mainly via kainate type GluRs.

Evaluation of bipolar electrocoagulation applied to biofiltration for phosphorus removal

To reduce the residual organic matter and phosphorus contained in secondary effluent, a biofiltration system combined with electrocoagulation using bipolar iron electrodes was evaluated as a supplementary treatment to existing small-community sewage treatment. Based on the results of batch tests, bipolar electrocoagulation (BEC) was found to be more effective on phosphorus removal than monopolar electrocoagulation (MEC) but energy consumption was less in monopolar electrocoagulation. Optimum conditions of BEC to treat the secondary effluent were current density 15 A/m2, electrode spacing 1 cm and pH < 8. The removals of COD(Cr) and phosphorus by biofiltration system without BEC were 69.1% and 9.6%, respectively. However, biofiltration system combined with BEC showed 76.6-83.7% and 70.7-93.0% removal for COD(Cr) and phosphorus respectively. Extraordinary increase in phosphorus could be achieved by introducing electrocoagulation to biofiltration, and BEC/biofiltration system was evaluated to be applicable to existing small-community sewage treatment plants as a supplementary process.

Long-term evaluation of mice model infected with Helicobacter pylori: focus on gastric pathology including gastric cancer

BACKGROUND

Long-term evaluation of gastric pathology after H. pylori infection is very important in order to reveal its clinical implications, since debate still exists on the gastric carcinogenesis provoked by H. pylori infection in animal models.

AIM

Either to evaluate the long-term outcome of H. pylori infection or to determine how H. pylori could provoke gastric cancer in the mice model.

METHODS

Four-week-old specific pathogen free C57BL/6 mice (n = 115) were infected with SS1, the mouse-adapted H. pylori strain. After 4, 8, 16, 24, 36, 50 and 80 weeks of bacterial infection, the H. pylori-infected mice were sacrificed.

RESULTS

After 80 weeks of infection, almost all the H. pylori-infected mice developed hyperplastic gastritis, but did not show any evidence of gastric adenoma, dysplasia or carcinoma. PCNA positive cells were most abundant after 50 weeks and tended to decrease thereafter up to 80 weeks, whereas apoptosis began to be noted 8 weeks after H. pylori infection, showing 7-8 apoptotic cells/high power field, and tending to increase as time passed. Normally observed neutral mucin decreased during the experiment, showing the most marked decrease 50 weeks after H. pylori infection. In contrast, acidic mucin was noted from 50 weeks after infection.

CONCLUSION

The SS1-infected mouse seems to be a suitable animal model for H. pylori-related research, and H. pylori itself does not induce gastric cancer in normal wild-type mouse model following long-term exposure, which could be explained by the balance that exists between cell proliferation and apoptosis.

Effect of long-term administration of rebamipide on Helicobacter pylori infection in mice

BACKGROUND

It has been suggested that chronic, persistent, uncontrolled inflammations in the stomach could provide the basic step for the beginning of carcinogenesis. One of the potential clinical applications of rebamipide is the inhibition of the immunoinflammatory response in gastric mucosa imposed by Helicobacter pylori.

AIM

To determine the implications of long-term rebamipide treatment in H. pylori infection, we studied the underlying moleculo-pathological changes in gastric lesions in mice infected with H. pylori (SS1 strain), following this treatment.

METHODS

C57BL/6 mice were sacrificed 24 and 50 weeks after H. pylori infection, respectively. Colonization rates of H. pylori, degree of gastric inflammation and other pathological changes including atrophic gastritis and metaplasia, serum levels of IL-1beta, TNF-alpha, IFN-gamma and IL-10, mRNA transcripts of various mouse cytokines and chemokines, and NF-kappaB binding activities, and finally the presence of gastric adenocarcinoma were compared between an H. pylori infected group (HP), and an H. pylori infected group administered with long-term rebamipide-containing pellet diets (HPR).

RESULTS

Serum levels of IL-1beta, IFN-gamma and TNF-alpha, the gastric mucosal expression of ICAM-1, HCAM and MMP, and transcriptional regulation of NF-kappaB-DNA binding were all significantly decreased in the HPR group compared with the HP group. An RNase protection assay showed, in the rebamipide administered group, significantly decreased mRNA levels of apoptosis-related genes such as caspase-8, FasL, Fas, TRAIL and various cytokines genes such as IFN-gamma, RANTES, TNF-alpha, TNFR p75, IL-1beta. In the experiment designed to provoke gastric cancer through MNU treatment with H. pylori infection, the incidence of gastric carcinoma was not different in either group. However, long-term administration of rebamipide showed the advantage of decreasing precancerous lesions like chronic atrophic gastritis and showed molecular evidence of attenuation of proliferation.

CONCLUSION

The long-term administration of rebamipide should be considered in the treatment of H. pylori since it demonstrated molecular and biological advantages like a lessening of gastric inflammation and a possible chemopreventive effect.

Comparative study of three-dimensional and conventional endorectal ultrasonography used in rectal cancer staging

BACKGROUND

Three-dimensional (3D) imaging offers improved knowledge of various anatomic structures and tumors by providing 3D images. This prospective study was performed to verify whether 3D endorectal ultrasonography (EUS) enhances the accuracy of rectal cancer staging, as compared with conventional EUS.

METHODS

Using both 3D and conventional EUS, 33 consecutive patients with operable rectal cancer were preoperatively staged. A rigid 3D probe with a scanner was used for 3D EUS, and a rigid endorectal probe with a scanner was used for conventional EUS.

RESULTS

The accuracy of 3D EUS was 90.9% for pT2 and 84.8% for pT3, whereas that of conventional EUS was 84.8% and 75.8%, respectively, thereby showing no difference between these two methods. The lymph node metastasis was accurately predicted by 3D EUS in 28 patients (84.8%), whereas conventional EUS predicted the disorder in 22 patients (66.7%). The difference was not statistically significant. The average infiltration grade of the circumference on transverse 3D EUS scans was associated closely with advancement of the TNM stage (p <0.001-0.006) and lymph node metastasis (p = 0.003). The presence of a cone-shaped surface on the deep tumor border correlated with the infiltration grade shown on all of the sectional displays (p <0.001-0.042) and with advancement of the TNM stage (p = 0.018).

CONCLUSIONS

Although the findings did not show 3D EUS to have a significant advantage over conventional EUS for the accurate evaluation of rectal cancer, a numeric advantage may possibly be statistically significant in a further study with larger cases. Furthermore, stereoscopic visualization provided easier and complete understanding of both focal lesions and lymph nodes.

Expression of multidrug resistance-associated protein1,P-glycoprotein, and thymidylate synthase in gastric cancer patients treated with 5-fluorouracil and doxorubicin-based adjuvant chemotherapy after curative resection

Both 5-fluorouracil and doxorubicin are commonly used agents in chemotherapy of gastric cancer in adjuvant setting as well as metastatic disease. In a variety of malignancies, high expression of multidrug resistance-associated protein1 and P-glycoprotein has been associated with resistance to doxorubicin, whereas 5-fluorouracil resistance has correlated with the level of thymidylate synthase expression. We evaluated the expression of multidrug resistance-associated protein1, P-glycoprotein, and thymidylate synthase using immunohistochemistry in 103 locally advanced gastric cancer patients (stage IB-IV) who underwent 5-fluorouracil and doxorubicin-based adjuvant chemotherapy after curative resection and investigated the association between their expression and clinicopathologic characteristics including prognosis of the patients. While high expression (> or =5% of tumour cells positive) of multidrug resistance-associated protein1 and P-glycoprotein was observed in 70 patients (68%) and 42 patients (41%), respectively, 65 patients (63%) had primary tumours with high expression (> or =25% of tumour cells positive) of thymidylate synthase. There was a significant association between multidrug resistance-associated protein1 and P-glycoprotein expression (P<0.0001) as well as P-glycoprotein and thymidylate synthase expression (P<0.0001). High multidrug resistance-associated protein1 and P-glycoprotein expressions were associated with well and moderately differentiated histology (P<0.0001 and P=0.03, respectively) and intestinal type (P<0.0001 and P=0.009, respectively). High multidrug resistance-associated protein1 expression correlated with lymph node metastasis (P=0.037), advanced stage (P=0.015), and older age (P=0.021). Five-year disease-free survival and overall survival of total patients were 55.2% and 56.2%, respectively, with a median follow-up of 68 months. There were no significant differences in disease-free survival and overall survival according to the expression of multidrug resistance-associated protein1 (P=0.902 and P=0.975, respectively), P-glycoprotein (P=0.987 and P=0.955, respectively), and thymidylate synthase (P=0.604 and P=0.802, respectively). Concurrent high expression of these proteins (high multidrug resistance-associated protein1/P-glycoprotein, high multidrug resistance-associated protein1/thymidylate synthase, high P-glycoprotein/thymidylate synthase) did not correlate with disease-free survival or overall survival. Even high expression of all three proteins was not associated with poor disease-free survival (P=0.919) and overall survival (P=0.852). In conclusion, high expression of multidrug resistance-associated protein1, P-glycoprotein, and thymidylate synthase did not predict poor prognosis of gastric cancer patients treated with 5-fluorouracil and doxorubicin-based adjuvant chemotherapy. A larger study including patients treated with surgical resection alone would be necessary.

Methylation of O(6)-methylguanine-DNA methyltransferase gene is associated significantly with K-ras mutation, lymph node invasion, tumor staging, and disease free survival in patients with gastric carcinoma

BACKGROUND

O(6)-methylguanine-DNA methyltransferase (MGMT) can remove O(6)alkylG DNA adducts. If they are not removed, then the adducts mispair with T during DNA replication, resulting in G-to-A mutation. Interrelations between MGMT gene inactivation by promoter methylation, K-ras mutation, and clinicopathologic features in patients with gastric carcinoma were studied.

METHODS

Surgically removed tumor tissues from 79 patients were analyzed with MGMT methylation by genomic DNA modification and methylation specific polymerase chain reaction analysis, K-ras mutation by mutant allele specific amplification, TNM classification according to the International Union Against Cancer system, and MGMT protein expression by immunohistochemistry.

RESULTS

MGMT-promoter methylation was found in 18 of 79 tumors. Among those 18 tumors, K-ras mutations were found in 33% and 11% of tumors at codons 12 and 13, respectively, corresponding to 20 times and 7 times greater rates of mutation compared with unmethylated tumors. MGMT methylation was associated significantly with lymph node invasion (P < 0.01), tumor stage (P < 0.03) and 5-year disease free survival (P < 0.02). MGMT protein expression was detected in intestinal metaplasia and adenocarcinoma samples, whereas no expression was detected in normal foveolar cells.

CONCLUSIONS

MGMT-promoter methylation in patients with gastric carcinoma was associated significantly with point mutations of K-ras at codons 12 and 13, lymph node invasion, tumor stage, and disease free survival. These associations indicate a significant role of MGMT methylation during gastric carcinogenesis.

Phylogenetic analysis of reverse transcriptase in antiretroviral drug-naive Korean HIV type 1 patients

To study whether genotypic antiretroviral resistance testing (GART) is needed to guide initial antiretroviral therapy in Korea, we determined partial pol sequences in peripheral blood mononuclear cells (PBMCs) obtained from 29 antiretroviral drug-naive HIV-1 patients. Phylogenetic analysis revealed four subtypes: B (23 patients), D (1 patient), recombinant strain (2 patients), and "untyped" (3 patients). Eighteen (78.3%) of the 23 subtype B isolates formed a distinct monophyletic cluster. The average genetic distances of 23 subtype B compared with reference strain HXB2 were 2.7% (range, 1.5-4.6%). Only one patient harbored variant virus containing a V179D mutation causing resistance to efavirenz. These data derived from therapy-naive patients suggest that potential use of primary resistance testing to guide initial antiretroviral therapy should be considered in Korea. This is the first report on the molecular nature of HIV-1 RT in Korea.

Construction of the Korea Elderly Pharmacoepidemiologic Cohort: drug utilization review of cephalosporins in geriatric inpatients

We performed a cohort-based pharmacoepidemiologic study in order to evaluate the pattern of cephalosporin prescriptions in elderly inpatients in Korea. The Korea Elderly Pharmacoepidemiologic Cohort was composed of a geriatric population of beneficiaries of the Korea Medical Insurance Corporation residing in Busan in 1993. The cohort consisted of 23,649 members, comprising 15,221 women (64.4%) and 8428 men (35.6%). The study population for drug utilization review consisted of those cohort members who were admitted into hospitals during the period January 1993 through December 1994. The number of hospitalized patients was 4262, comprising 2631 women (61.7%) and 1681 men (38.3%). The trend of cephalosporin prescriptions over the 2-year period showed that the use of second and third generation cephalosporins increased relative to the use of first generation. The use of cephalosporins combined with other antibiotics was found to occur in 22.8% aminoglycosides (76.7%) and quinolones (17.1%) being the most common antibiotics combined with cephalosporins. Our result demonstrates an increase in the prescription of second and third generation cephalosporins in Korea, which has implications not only for the elderly population but also for the total population because of the impact on health care costs and the potential for the emergence of antimicrobial resistance.

Induction of apoptotic cell death by a p53-independent pathway in neuronal SK-N-MC cells after treatment with 2,2',5,5'-tetrachlorobiphenyl

Apoptotic cell death is an active process, which is a critical feature of the regulated development of multicellular organisms. Polychlorinated biphenyls (PCBs) are ubiquitous environmental contaminants, some of which may be neurotoxic. This study investigates the 2,2', 5,5'-tetrachlorobiphenyl (PCB 52) induced apoptosis in human neuronal SK-N-MC cells, and the role of p53 in this response. Upon treatments with PCB 52, time- and concentration-dependent inhibition of the cell viability was observed. PCB 52 also caused apoptosis, as measured by cell morphology and DNA fragmentation. The capability of PCB 52 to induce apoptosis was associated with the proteolytic cleavage of specific target proteins, such as poly(ADP-ribose) polymerase (PARP) and beta-catenin proteins, suggesting the possible involvement of caspases. In general, DNA-damaging agents induce accumulation of the tumor suppressor protein p53, leading cells to either growth arrest in G1, or apoptosis. However, our data showed that both p53 and Bcl-2 protein levels were decreased in a time-dependent manner during apoptosis after exposure to PCB 52. These results suggest that PCB 52 induced a p53-independent apoptosis in these cells.

Long-term intake of Korean red ginseng in HIV-1-infected patients: development of resistance mutation to zidovudine is delayed

We have observed that CD4+ T cell counts in human immunodeficiency virus (HIV)-1-infected patients treated with only Korean red ginseng (KRG) are maintained or even increased for a prolonged period. In the present study, we investigated whether the development of resistance mutations in reverse transcriptase (RT) to zidovudine (ZDV) is delayed by combined therapy with KRG and ZDV. Nested polymerase chain reaction (PCR) and direct sequencing methods were used to define RT codons 41, 67, 70, 210, 215 and 219 of the HIV-1 pol gene in DNA from peripheral blood mononuclear cells (PBMC) samples from 18 patients. Nine of these eighteen patients were in the KRG group and had been treated with KRG for 60 +/- 15 months (range: 38-82) and ZDV, and nine were in the control group and had been treated with ZDV only. The patients in the KRG group had been treated with ZDV for 75 +/- 24 months, and CD4+ T cell counts were maintained from 239 +/- 85 to 234 +/- 187 microliters-1 (P > 0.05) during the study period, whereas the patients in the control group had been treated with ZDV for 51 +/- 31 months, and their CD4+ T cell counts decreased from 272 +/- 97 to 146 +/- 154 microliters-1 (P < 0.01). In samples within 24 months of ZDV therapy, the overall incidence of 6 resistance mutations to ZDV was 4.2% and 47% in the KRG and control group (P < 0.01), respectively. In samples after 24 months of therapy, the incidence was 21.7% and 56.3% in the KRG and control group (P < 0.01), respectively. These data suggest that the maintenance of CD4+ T cell counts by ZDV and KRG-intake for a prolonged period might be indirectly associated with delayed development of resistance to ZDV by KRG-intake.

Myocardial creatine kinase kinetics and isoform expression in hearts with severe LV hypertrophy

Left ventricular (LV) hypertrophy (LVH) results in a fetal shift in myocardial creatine kinase (CK) expression. Because CK plays an important role in intracellular energy production, transport, and utilization, this study was performed to characterize changes in CK expression and CK flux in severe pressure-overload LVH. Ascending aortic banding in 8-wk-old dogs resulted in LVH with a 92% increase in relative LV mass. In LVH hearts, CK-M isoform mRNA was decreased by 40% (P = 0.05) and protein was decreased by 50% (P < 0.01), whereas mitochondrial CK protein was decreased by 22% (P < 0.05). CK-B isoform mRNA was undetectable in normal hearts but was prominently expressed in LVH (P < 0.01); CK-B protein was increased by more than 10-fold in LVH (P < 0.01). Despite these changes, total CK activity was normal in LVH. Myocardial CK flux was examined using (31)P magnetic resonance spectroscopy magnetization transfer. The CK forward rate constant was similar in normal and LVH hearts at baseline and did not change in either group during dobutamine treatment. In hearts with LVH, the CK forward flux rate was reduced by approximately 60% (P < 0.05) and decreased further during dobutamine. Thus, although pressure-overload LVH caused alterations of expression of both CK mRNA and protein levels, LV performance and oxygen consumption in response to dobutamine were normal. However, myocardial free ADP was increased in LVH hearts. This finding suggests that the CK alterations result in a need for higher ADP levels to maintain ATP synthesis in the hypertrophied heart.

Glomus tumor of the stomach: CT findings

We present the radiologic findings of gastric glomus tumors in two patients, in whom upper gastrointestinal series and computed tomography (CT) were primarily used for diagnosis. The diagnosis was surgically confirmed. Contrast-enhanced CT showed peripheral nodular or homogeneous strong enhancement in the arterial phase and prolonged enhancement in the delayed phase.

Characterization of mevalonate kinase V377I, a mutant implicated in defective isoprenoid biosynthesis and HIDS/periodic fever syndrome

The list of diseases linked to defects in lipid metabolism has recently been augmented by the addition of hyperimmunoglobulinemia D and periodic fever syndrome (HIDS: MIM 260920), which are correlated with depressed levels of mevalonate kinase activity [1,2] and protein [1]. More specifically, a V377I substitution has been proposed to account for this disease. We observed that V377 appears to be far from invariant in eukaryotic mevalonate kinases. Prokaryotic mevalonate kinases are lower in molecular weight and several terminate prior to residue 377 of the eukaryotic proteins. These observations prompted our direct test of the impact of V377 on activity and protein stability by engineering a V377I mutation in a recombinant human mevalonate kinase. The mutant protein has been isolated and kinetically characterized. In comparison with wild-type enzyme, V377I exhibits only modest differences (notably > or = 6-fold inflation of K(m(MVA))) that do not account for the diminished mevalonate kinase activity assayed in HIDS cell extracts. Moreover, thermal inactivation (50 degrees C) of isolated wild-type and V377I enzymes demonstrates little difference in stability between these proteins. We conclude that a single V377I substitution is unlikely to explain the observation of depressed mevalonate kinase stability and catalytic activity in HIDS.

Investigation of invariant serine/threonine residues in mevalonate kinase. Tests of the functional significance of a proposed substrate binding motif and a site implicated in human inherited disease

Mevalonate kinase serine/threonine residues have been implicated in substrate binding and inherited metabolic disease. Alignment of >20 mevalonate kinase sequences indicates that Ser-145, Ser-146, Ser-201, and Thr-243 are the only invariant residues with alcohol side chains. These residues have been individually mutated to alanine. Structural integrity of the mutants has been demonstrated by binding studies using fluorescent and spin-labeled ATP analogs. Kinetic characterization of the mutants indicates only modest changes in K(m)((ATP)). K(m) for mevalonate increases by approximately 20-fold for S146A, approximately 40-fold for T243A, and 100-fold for S201A. V(max) changes for S145A, S201A, and T243A are < or =3-fold. Thus, the 65-fold activity decrease associated with the inherited human T243I mutation seems attributable to the nonconservative substitution rather than any critical catalytic function. V(max) for S146A is diminished by 4000-fold. In terms of V/K(MVA), this substitution produces a 10(5)-fold effect, suggesting an active site location and catalytic role for Ser-146. The large k(cat) effect suggests that Ser-146 productively orients ATP during catalysis. K(D(Mg-ATP)) increases by almost 40-fold for S146A, indicating a specific role for Ser-146 in liganding Mg(2+)-ATP. Instead of mapping within a proposed C-terminal ATP binding motif, Ser-146 is situated in a centrally located motif, which characterizes the galactokinase/homoserine kinase/ mevalonate kinase/phosphomevalonate kinase protein family. These observations represent the first functional demonstration that this region is part of the active site in these related phosphotransferases.

Expression of thymidylate synthase in gastric cancer patients treated with 5-fluorouracil and doxorubicin-based adjuvant chemotherapy after curative resection

We evaluated the expression of thymidylate synthase (TS) in locally advanced gastric cancer patients treated with adjuvant chemotherapy after curative resection and investigated the association between TS expression and clinicopathologic characteristics including prognosis of the patients. TS expression was evaluated by immunohistochemical staining using TS106 monoclonal antibody in 103 locally advanced gastric cancer patients (stage IB-IV) who underwent 5-fluorouracil (5-FU) and doxorubicin-based adjuvant chemotherapy after curative resection. 65 patients (63%) had primary tumours with high TS expression (> or = 25% of tumour cells positive), and 38 patients (37%) demonstrated low TS expression (< 25% of tumour cells positive or no staining). High TS expression was associated with male gender (P = 0.002), poorly differentiated histology (P = 0.015), and mixed type in Lauren's classification (P = 0.027). There were no statistically significant differences in 4-year disease-free survival (60.0% vs. 57.2%, P = 0.548) and overall survival (59.6% vs. 59.3%, P = 0.792) between high-TS group and low-TS group. In conclusion, although high TS expression was associated with poorly differentiated histology and mixed type in Lauren's classification, it did not predict poor disease-free and overall survival in gastric cancer patients treated with 5-FU and doxorubicin-based adjuvant chemotherapy after curative resection. Further prospective studies including the evaluation of other biological markers associated with the resistance to 5-FU and doxorubicin are necessary.

Noninvasive measurements of transmural myocardial metabolites using 3-D (31)P NMR spectroscopy

A completely noninvasive three-dimensional (3-D) static magnetic field magnitude spatially localized (31)P spectroscopy technique has been developed and applied to study the in vivo canine myocardium at 9.4 T. The technique incorporates both Fourier series windows and selective Fourier transform methods utilizing all three orthogonal gradients for 3-D phase encoding. The number of data acquisitions for each phase-encoding step was weighted according to the Fourier coefficients to define cylindrical voxels. Spatially localized (31)P spectra can be generated for voxels of desired location within the field of view as a postprocessing step. The quality of localization was first demonstrated by using a three-compartment phantom. The technique was then applied to in vivo canine models and yielded (31)P cardiac spectra with an excellent signal-to-noise ratio. The in vivo validation experiments, using an implanted 2-phosphoenolpyruvate-containing marker, demonstrated that the technique is capable of measuring at least two transmural layers of left ventricular myocardium representing the subepicardium and subendocardium.

Protective effects of (-)-epigallocatechin-3-gallate on UVA- and UVB-induced skin damage

It has been known that green tea and its components possess significant chemopreventive effects against chemical carcinogens and photo-caused skin tumor formation. In this study, the protective effects of (-)-epigallocatechin-3-gallate (EGCG), a major green tea catechin, on the ultraviolet (UV)-induced skin damage (photoaging) were studied in guinea pigs, hairless mice and human dermal fibroblast cultures. The lipid peroxidation was significantly reduced in the EGCG-treated group. The amount of lipid peroxides produced in the control and EGCG treated group were 838 +/- 144 and 286 +/- 57 nmol/mg at 18 h after UV irradiation, respectively. UVB-induced erythema was also significantly reduced in the EGCG treated group. The erythema relative index of the control and the EGCG treated group were 311 +/- 45 and 191 +/- 49 at 16 h after UV irradiation, respectively. EGCG treatment reduced UVA-induced skin damage (roughness and sagginess) and protected from the decrease of dermal collagen in hairless mouse skin. EGCG treatment blocked the UV-induced increase of collagen secretion and collagenase mRNA level in fibroblast culture. The nuclear transcription factors NF-kappaB and AP-1 binding activities were also inhibited by EGCG treatment.

Systemic lupus erythematosus: brain MR imaging and single-voxel hydrogen 1 MR spectroscopy

PURPOSE

To evaluate the usefulness of magnetic resonance (MR) imaging and hydrogen 1 MR spectroscopy in the detection of brain involvement in patients with systemic lupus erythematosus (SLE) with or without neuropsychiatric symptoms.

MATERIALS AND METHODS

Twenty-six patients who had SLE with (n = 17) or without (n = 9) neuropsychiatric symptoms were examined at MR imaging and (1)H MR spectroscopy. The voxel was placed in the basal ganglia and peritrigonal white matter. Eight healthy volunteers were included.

RESULTS

Five of nine patients with major neuropsychiatric symptoms and one of eight patients with minor neuropsychiatric symptoms had abnormal MR imaging findings. (1)H MR spectroscopy showed a significantly decreased N:-acetylaspartate-creatine (Cr) ratio in the basal ganglia and an increased choline-Cr ratio in the peritrigonal white matter in patients with major symptoms compared with those with minor symptoms, those without symptoms, and healthy control subjects. Among patients with major symptoms, there was no difference in metabolite ratios between those with and those without abnormal MR imaging findings. Among patients with normal MR imaging findings, abnormal spectral changes were observed only in those with major neuropsychiatric symptoms. In patients without neuropsychiatric symptoms, results of (1)H MR spectroscopy and MR imaging were normal.

CONCLUSION

In patients with SLE, (1)H MR spectroscopic findings seem to reflect the cerebral metabolic disturbance related to the severity of the neuropsychiatric symptoms and are not related to the presence of abnormal MR imaging findings.

Perigastric lymph node status can be a simple prognostic parameter in patients with gastric cancer

BACKGROUND/AIMS

The number of metastatic lymph nodes has been a significant prognostic factor after curative resection of gastric cancer and adopted as a new UICC classification of nodal stages in gastric cancer. The extent of lymphadenectomy is another significant factor but has been fiercely debated. Regardless of the type of lymphadenectomy, perigastric lymph node dissection is always carried out. In this study, we examined whether the number of metastatic perigastric nodes can be a prognostic indicator of gastric cancer.

METHODOLOGY

For the purpose of evaluating perigastric lymph node status, a retrospective study was carried out with 760 patients who underwent curative gastric resection from June 1994 to November 1998.

RESULTS

The 4-year cumulative survival rate was 64% and the survival rate decreased significantly when the number of positive perigastric nodes exceeded 3. Comparing with the patients having 0-2 positive perigastric nodes, patients whose metastatic perigastric lymph nodes exceeded 3 or more exhibited deeper tumor invasion, larger tumor size and older age. Multivariate analysis identified the number of positive perigastric nodes, together with depth of tumor invasion, as the strongest independent prognostic factors for survival.

CONCLUSIONS

We suggest that the number of metastatic perigastric nodes can be used as a simple prognostic parameter in patients with gastric cancer and that intensive follow-up and adjuvant chemotherapy should be recommended for the patients with more than 3 metastatic perigastric nodes.

Effects of high pressure on solvent isotope effects of yeast alcohol dehydrogenase

The effect of pressure on the capture of a substrate alcohol by yeast alcohol dehydrogenase is biphasic. Solvent isotope effects accompany both phases and are expressed differently at different pressures. These differences allow the extraction of an inverse intrinsic kinetic solvent isotope effect of 1.1 (i.e., (D(2(O)))V/K = 0.9) accompanying hydride transfer and an inverse equilibrium solvent isotope effect of 2.6 (i.e., (D(2(O)))K(s) = 0.4) accompanying the binding of nucleotide, NAD(+). The value of the kinetic effect is consistent with a reactant-state E-NAD(+)-Zn-OH(2) having a fractionation factor of phi approximately 0.5 for the zinc-bound water in conjunction with a transition-state proton exiting a low-barrier hydrogen bond with a fractionation factor between 0.6 and 0.9. The value of the equilibrium effect is consistent with restrictions of torsional motions of multiple hydrogens of the enzyme protein during the conformational change that accompanies the binding of NAD(+). The absence of significant commitments to catalysis accompanying the kinetic solvent isotope effect means that this portion of the proton transfer occurs in the same reactive step as hydride transfer in a concerted chemical mechanism. The success of this analysis suggests that future measurements of solvent isotope effects as a function of pressure, in the presence of moderate commitments to catalysis, may yield precise estimates of intrinsic solvent isotope effects that are not fully expressed on capture at atmospheric pressure.

Effect of pressure on deuterium isotope effects of yeast alcohol dehydrogenase: evidence for mechanical models of catalysis

Moderate pressure accelerates hydride transfer catalyzed by yeast alcohol dehydrogenase, indicative of a large negative volume of activation [Cho and Northrop (1999) Biochemistry 38, 7470-7475]. A comparison of the effects of pressure on the oxidation of normal versus dideuteriobenzyl alcohol generates a monophasic decrease in the intrinsic isotope effect; therefore, the volume of activation for the transition-state of deuteride transfer must be even more negative, by 10.4 mL/mol. This finding appears consistent with hydrogen tunneling previously proposed for this dehydrogenase [Cha, Y., Murray, C. J., and Klinman, J. P. (1989) Science 243, 1325-1330]. However, a global fit of the primary data shows that the entire isotope effect arises from a transition-state phenomenon, unlike normal isotope effects, which arise from different vibrational frequencies in reactant states, and tunneling isotope effects, which arise from a mixture of both states. Assuming the phenomenon is tunneling, the isotopic data are consistent with a Bell tunneling correction factor of Q(H) = 12 and an imaginary frequency of nu(H) = 1220 cm(-1), the first so calculated from experimental enzymatic data. This excessively large correction factor and the large difference in the isotopic activation volumes, plus the low isotope effects at extrapolated pressures, challenge traditional applications of physical organic chemistry and transition-state theory to enzymatic catalysis. They suggest instead that something other than transition-state stabilization or tunneling is responsible for the rate acceleration, something unique to the enzymatic transition state that does not occur in nonenzymatic reactions. Arguments for the vibrational model of coupled atomic motions and the fluctuating enzyme model of protein domain motion are put forward as possible interpretations.

Significant correlation between serum level of hepatocyte growth factor and progression of gastric carcinoma

Hepatocyte growth factor (HGF) can promote proliferation of many types of tumor cells including gastric cancer cells. To study the role of HGF in the progression of gastric carcinoma, HGF levels were measured by an enzyme immunoassay (EIA) system in sera of gastric cancer patients and followed up the levels after the operation. The mean serum HGF level in 212 healthy control subjects, 140 patients with primary gastric cancer, and 13 patients with recurrent gastric cancer were 0.199 +/- 0.073, 0.325 +/- 0.209, and 0.578 +/- 0.258 ng/ml, respectively. The increase of the levels was significantly correlated with the progression of tumor stage. The levels decreased to normal levels 1 month after curative resection of the tumors. However, the levels did not decrease significantly in nonresected cases. During the follow-up of the patients for several months, the level was significantly increased in recurrent gastric cancer patients, whereas there was no increase in nonrecurrent patients. In conclusion, the serum HGF levels significantly correlated with the aggressiveness of the tumors, suggesting an important role of HGF in the progression of gastric carcinoma.