A preliminary randomized controlled trial of repetitive transcranial magnetic stimulation applied to the left dorsolateral prefrontal cortex in treatment seeking participants with cannabis use disorder

BACKGROUND

Cannabis use disorder (CUD) is a common and consequential disorder. When applied to the dorsolateral prefrontal cortex (DLPFC), repetitive transcranial magnetic stimulation (rTMS) reduces craving across substance use disorders and may have therapeutic clinical effects when applied in serial-sessions. The present study sought to preliminarily determine whether serial-sessions of rTMS applied to the DLPFC had a therapeutic effect in CUD.

METHODS

This study was a two-site, phase-2, double-blind, randomized-controlled-trial. Seventy-two treatment-seeking participants (37.5% Women, mean age 30.2±9.9SD) with ≥moderate-CUD were randomized to active or sham rTMS (Beam-F3, 10Hz, 20-total-sessions, two-sessions-per-visit, two-visits-per-week, with cannabis cues) while undergoing a three-session motivational enhancement therapy intervention. The primary outcome was the change in craving between pre- and post- treatment (Marijuana Craving Questionnaire Short-Form-MCQ-SF). Secondary outcomes included the number of weeks of abstinence and the number of days-per-week of cannabis use during 4-weeks of follow-up.

RESULTS

There were no significant differences in craving between conditions. Participants who received active-rTMS reported numerically, but not significantly, more weeks of abstinence in the follow-up period than those who received sham-rTMS (15.5%-Active; 9.3%-Sham; rate ratio = 1.66 [95% CI: 0.84, 3.28]; p=0.14). Participants who received active-rTMS reported fewer days-per-week of cannabis use over the final two-weeks of the follow-up period than those receiving sham-rTMS (Active vs. Sham: -0.72; Z=-2.33, p=0.02).

CONCLUSIONS

This trial suggests rTMS is safe and feasible in individuals with CUD and may have a therapeutic effect on frequency of cannabis use, though further study is needed with additional rTMS-sessions and a longer follow-up period.

Study protocol for a sequential multiple assignment randomized trial to reduce risky drinking among service members and their partners

BACKGROUND

Military spouses and partners in relationships with a heavy drinking service member report high levels of mental health concerns and consequences, which are compounded when both partners drink heavily. Military spouses and partners -termed "concerned partners" (CPs)-may be an important gateway for motivating service members (SMs) to seek care. However, CPs may first need to reduce their own drinking and improve their communication to effectively support and encourage changes for their service member partner. Partners Connect is a web-based intervention aimed at improving communication and relationship quality and increasing SM help-seeking.

METHODS

The current study design is a two-stage Sequential Multiple Assignment Randomized Trial (SMART) to develop an adaptive CP intervention to decrease CP drinking and increase SM help-seeking. CPs aged 18 and older (n = 408) will be recruited via social media and followed for six months. In stage one, we will randomize CPs to either a 4-session web-based intervention (Partners Connect) or to receive communication resources from the Gottman Institute website. The goal is to have CPs invite their SM to complete an online personalized normative feedback (PNF) session. If their SM completes the PNF at stage one, CPs will be considered "responders," if the SM does not complete, CPs who are "non-responders" will be re-randomized during stage two to receive either (1) a CRAFT workbook or (2) phone-based CRAFT if in Partners Connect; or (1) Partners Connect or (2) a CRAFT workbook if in Gottman.

DISCUSSION

By first intervening with the service member's CP, we aim to better equip them to engage their service member partner in treatment services. In doing so, we develop a model that increases treatment accessibility and appeal among a group that may not otherwise seek care.

CLINICALTRIALS

gov Identifier: NCT05619185.

A Preliminary Investigation Of Repetitive Transcranial Magnetic Stimulation Applied To The Left Dorsolateral Prefrontal Cortex In Treatment Seeking Participants With Cannabis Use Disorder

Background

Cannabis use disorder (CUD) is a common and consequential disorder. When applied to the dorsolateral prefrontal cortex (DLPFC), repetitive transcranial magnetic stimulation (rTMS) reduces craving across substance use disorders and may have a therapeutic clinical effect when applied in serial sessions. The present study sought to preliminarily determine whether serial sessions of rTMS applied to the DLPFC had a therapeutic effect in CUD.

Methods

This study was a two-site, phase-2, double-blind, randomized-controlled-trial. Seventy-two treatment-seeking participants (37.5% Women, mean age 30.2±9.9SD) with ≥moderate-CUD were randomized to active or sham rTMS (Beam-F3, 10Hz, 20-total-sessions, with cannabis cues) while undergoing a three-session motivational enhancement therapy intervention. The primary outcome was the change in craving between pre- and post-treatment (Marijuana Craving Questionnaire Short-Form-MCQ-SF). Secondary outcomes included the number of weeks of abstinence and the number of days-per-week of cannabis use during 4-weeks of follow-up.

Results

There were no significant differences in craving between conditions. Participants who received active rTMS reported numerically, but not significantly, more weeks of abstinence in the follow-up period than those who received sham rTMS (15.5%-Active; 9.3%-Sham; rate ratio = 1.66 [95% CI: 0.84, 3.28]; p=0.14). Participants who received active rTMS reported fewer days-per-week of cannabis use over the final two-weeks of the follow-up period (Active vs. Sham: -0.72; Z=-2.33, p=0.02).

Conclusions

This trial suggests rTMS is safe and feasible in individuals with CUD and may have a therapeutic effect on frequency of cannabis use, though further study is needed with additional rTMS-sessions and a longer follow-up period.

Beliefs about prescription sleep medications and interest in reducing hypnotic use: an examination of middle-aged and older adults with insomnia disorder

STUDY OBJECTIVES

To examine beliefs about prescription sleep medications (hypnotics) among individuals with insomnia disorder seeking cognitive behavioral therapy for insomnia and predictors of wishing to reduce use.

METHODS

Baseline data was collected from 245 adults 50 years and older enrolled in the "RCT of the Effectiveness of Stepped-Care Sleep Therapy in General Practice" study. T-tests compared characteristics of prescription sleep medication users with those of nonusers. Linear regression assessed predictors of patients' beliefs about sleep medication necessity and hypnotic-related concerns. Among users, we examined predictors of wishing to reduce sleep medications, including perceived hypnotic dependence, beliefs about medications, and demographic characteristics.

RESULTS

Users endorsed stronger beliefs about the necessity of sleep medications and less concern about potential harms than nonusers (P < .01). Stronger dysfunctional sleep-related cognitions predicted greater beliefs about necessity and concern about use (P < .01). Patients wishing to reduce sleep medications reported greater perceived hypnotic dependence than those disinterested in reduction (P < .001). Self-reported dependence severity was the strongest predictor of wishing to reduce use (P = .002).

CONCLUSIONS

Despite expressing strong beliefs about necessity, and comparatively less concern about taking sleep medications, three-quarters of users wished to reduce prescription hypnotics. Results may not generalize to individuals with insomnia not seeking nonpharmacological treatments. Upon completion, the "RCT of the Effectiveness of Stepped-Care Sleep Therapy in General Practice" study will provide information about the extent to which therapist-led and digital cognitive behavioral therapy for insomnia contribute to prescription hypnotic reduction.

CLINICAL TRIAL REGISTRATION

Registry: ClinicalTrials.gov; Name: The RESTING Insomnia Study: Randomized Controlled Study on Effectiveness of Stepped-Care Sleep Therapy (RESTING); URL: https://clinicaltrials.gov/ct2/show/NCT03532282; Identifier: NCT03532282.

CITATION

Tully IA, Kim JP, Simpson N, et al. Beliefs about prescription sleep medications and interest in reducing hypnotic use: an examination of middle-aged and older adults with insomnia disorder. J Clin Sleep Med. 2023;19(7):1247-1257.

RCT of the effectiveness of stepped-care sleep therapy in general practice: The RESTING study protocol

Cognitive behavioral therapy for insomnia (CBT-I) is an effective, non-pharmacological intervention, designated by the American College of Physicians as the first-line treatment of insomnia disorder. The current randomized controlled study uses a Hybrid-Type-1 design to compare the effectiveness and implementation potential of two approaches to delivering CBT-I in primary care. One approach offers therapy to all patients through an automated, digital CBT-I program (ONLINE-ONLY). The other is a triaged STEPPED-CARE approach that uses a simple Decision Checklist to start patients in either digital or therapist-led treatment; patients making insufficient progress with digital treatment at 2 months are switched to therapist-led treatment. We will randomize 240 individuals (age 50 or older) with insomnia disorder to ONLINE-ONLY or STEPPED-CARE arms. The primary outcomes are insomnia severity and hypnotic medication use, assessed at baseline and at months 2, 4, 6, 9, and 12 after randomization. We hypothesize that STEPPED-CARE will be superior to ONLINE-ONLY in reducing insomnia severity and hypnotic use. We also aim to validate the Decision Checklist and explore moderators of outcome. Additionally, guided by the Reach, Effectiveness, Adoption, Implementation, and Maintenance (RE-AIM) framework, we will use mixed methods to obtain data on the potential for future dissemination and implementation of each approach. This triaged stepped-care approach has the potential to improve sleep, reduce use of hypnotic medications, promote safety, offer convenient access to treatment, and support dissemination of CBT-I to a large number of patients currently facing barriers to accessing treatment. Clinical trial registration:NCT03532282.

Viability of an Early Sleep Intervention to Mitigate Poor Sleep and Improve Well-being in the COVID-19 Pandemic: Protocol for a Feasibility Randomized Controlled Trial

BACKGROUND

The COVID-19 pandemic has led to drastic increases in the prevalence and severity of insomnia symptoms. These increases in insomnia complaints have been paralleled by significant decreases in well-being, including increased symptoms of depression, anxiety, and suicidality and decreased quality of life. However, the efficacy and impact of early treatment of insomnia symptoms on future sleep and well-being remain unknown.

OBJECTIVE

Here, we present the framework and protocol for a novel feasibility, pilot study that aims to investigate whether a brief telehealth insomnia intervention targeting new insomnia that developed during the pandemic prevents deterioration of well-being, including symptoms of insomnia, depression, anxiety, suicidality, and quality of life.

METHODS

The protocol details a 2-arm randomized controlled feasibility trial to investigate the efficacy of a brief, telehealth-delivered, early treatment of insomnia and evaluate its potential to prevent deterioration of well-being. Participants with clinically significant insomnia symptoms that began during the pandemic were randomized to either a treatment group or a 28-week waitlist control group. Treatment consists of 4 telehealth sessions of cognitive behavioral therapy for insomnia (CBT-I) delivered over 5 weeks. All participants will complete assessments of insomnia symptom severity, well-being, and daily habits checklist at baseline (week 0) and at weeks 1-6, 12, 28, and 56.

RESULTS

The trial began enrollment on June 3, 2020 and closed enrollment on June 17, 2021. As of October 2021, 49 participants had been randomized to either immediate treatment or a 28-week waitlist; 23 participants were still active in the protocol.

CONCLUSIONS

To our knowledge, this protocol would represent the first study to test an early sleep intervention for improving insomnia that emerged during the COVID-19 pandemic. The findings of this feasibility study could provide information about the utility of CBT-I for symptoms that emerge in the context of other stressors before they develop a chronic course and deepen understanding of the relationship between sleep and well-being.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04409743; https://clinicaltrials.gov/ct2/show/NCT04409743.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/34409.

Stakeholders' Perspectives regarding Participation in Neuromodulation-Based Dementia Intervention Research

This study evaluated stakeholders' perspectives regarding participation in two hypothetical neuromodulation trials focused on individuals with Alzheimer's disease and related disorders (ADRDs). Stakeholders (i.e., individuals at risk for ADRDs [n = 56], individuals with experience as a caregiver for someone with a cognitive disorder [n = 60], and comparison respondents [n = 124]) were recruited via MTurk. Primary outcomes were willingness to enroll (or enroll one's loved one), feeling lucky to have the opportunity to enroll, and feeling obligated to enroll in two protocols (transcranial magnetic stimulation, TMS; deep brain stimulation, DBS). Relative to the Comparison group, the At Risk group endorsed higher levels of "feeling lucky" regarding both research protocols, and higher willingness to participate in the TMS protocol. These findings provide tentative reassurance regarding the nature of decision making regarding neurotechnology-based research on ADRDs. Further work is needed to evaluate the full range of potential influences on research participation.

Twelve-day medium pumping into tubular cell-laden scaffold using a lab-made PDMS connector

In the current study, a method is proposed to supply culture medium into a two-layered cell-laden tubular scaffold in order to enhance cell proliferation, confluence, and viability. The two-layered cell-laden tubular scaffold was made of calcium-alginate mixed with fibroblast cells (NIH/3T3) using a lab-made double- coaxial laminar-flow generator. Afterwards, the tubular scaffold was connected to a syringe pump system using a polydimethylsiloxane (PDMS) micro-connector for long-term cell culture. Three medium pumping conditions were applied and compared: a heart-beat-mimicking pumping (20 µL/s, 1 s period, and 50 % pulse width), a continuous pumping (20 µL/s) and a non-pumping. Non-leaky connections between the tubular scaffolds and the micro-connector outlet were sustained for 13.5 ± 0.83 d in heartbeat-mimicking pumping and 11.8 ± 0.33 d in continuous pumping condition, due to the elasticity of the tubular scaffolds. Importantly, the two pumping conditions resulted in more cell proliferation, confluence, and viability than the non-pumping condition. Furthermore, analysis of newly-produced type-I collagen matrix indicated that the cells under the two pumping conditions formed a tissue-like structure. The proposed technique could further be applied to vascular co-culturing for vascular engineered tissue.

C3d-binding Donor-specific HLA Antibody Is Associated With a High Risk of Antibody-mediated Rejection and Graft Loss in Stable Kidney Transplant Recipients: A Single-center Cohort Study

BACKGROUND

One risk factor for antibody-mediated rejection (ABMR) and poor outcome after kidney transplantation is donor-specific anti‒human leukocyte antigen (anti-HLA) antibodies (DSAs). In this study we sought to determine whether the presence of DSAs that bind complement component C3d could better predict ABMR and graft loss in stable kidney transplant recipients (KTRs).

METHODS

We included 220 stable KTRs in this study and screened them for DSAs from July 2013 to July 2016.

RESULTS

Of the 220 KTRs, DSAs were detected in 24 (10.9%). The incidence of ABMR was 3.6% (8 of 220) overall, and C3d-DSA‒positive KTRs had a significantly higher incidence than SA-DSA‒positive KTRs (63.3% vs 38.9%, P = .03). Most C3d-binding DSAs were anti-HLA class II antibodies (11 of 13, 84.6%). Class II C3d-binding DSA was also significantly associated with graft failure on multivariate analysis, as were ABMR, chronic ABMR, and high serum creatinine. Class II C3d-binding DSA was also significantly associated with lower graft survival after ABMR.

CONCLUSION

C3d-binding DSA, especially class II, was significantly associated with the risk of ABMR and graft loss in stable KTRs. We suggest that monitoring of stable KTRs for C3d-binding DSA, followed by biopsy, could aid in early recognition of ABMR and prevention of graft loss.

Lifetime anxiety disorder and current anxiety symptoms associated with hastened depressive recurrence in bipolar disorder

AIMS

To assess differential relationships between lifetime anxiety disorder/current anxiety symptoms and longitudinal depressive severity in bipolar disorder (BD).

METHODS

Stanford BD Clinic outpatients enrolled during 2000-2011 were assessed with the Systematic Treatment Enhancement Program for BD (STEP-BD) Affective Disorders Evaluation and followed with the STEP-BD Clinical Monitoring Form while receiving naturalistic treatment for up to two years. Baseline unfavorable illness characteristics/current mood symptoms and times to depressive recurrence/recovery were compared in patients with versus without lifetime anxiety disorder/current anxiety symptoms.

RESULTS

Among 105 currently recovered patients, lifetime anxiety disorder was significantly associated with 10/27 (37.0%) demographic/other unfavorable illness characteristics/current mood symptoms/current psychotropics, hastened depressive recurrence (driven by earlier onset age), and a significantly (> two-fold) higher Kaplan-Meier estimated depressive recurrence rate, whereas current anxiety symptoms were significantly associated with 10/27 (37.0%) demographic/other unfavorable illness characteristics/current mood symptoms/current psychotropics and hastened depressive recurrence (driven by lifetime anxiety disorder), but only a numerically higher Kaplan-Meier estimated depressive recurrence rate. In contrast, among 153 currently depressed patients, lifetime anxiety disorder/current anxiety symptoms were not significantly associated with time to depressive recovery or depressive recovery rate.

LIMITATIONS

American tertiary BD clinic referral sample, open naturalistic treatment.

CONCLUSIONS

Research is needed regarding differential relationships between lifetime anxiety disorder and current anxiety symptoms and hastened/delayed depressive recurrence/recovery - specifically whether lifetime anxiety disorder versus current anxiety symptoms has marginally more robust association with hastened depressive recurrence, and whether both have marginally more robust associations with hastened depressive recurrence versus delayed depressive recovery, and related clinical implications.

Is a short arm cast appropriate for stable distal radius fractures in patients older than 55 years? A randomized prospective multicentre study

We conducted a prospective randomized, multicentre study to compare short arm and long arm plaster casts for the treatment of stable distal radius fracture in patients older than 55 years. We randomly assigned patients over the age of 55 years who had stable distal radius fracture to either a short arm or long arm plaster cast at the first review 1 week after their injury. Radiographic and clinical follow-up was conducted at 1, 3, 5, 12 and 24 weeks following their injury. Also, degree of disability caused by each cast immobilization was evaluated at the patient's visit to remove the cast. There were no significant differences in radiological parameters between the groups except for volar tilt. Despite these differences in volar tilt, neither functional status as measured by the Disabilities of the Arm, Shoulder and Hand, nor visual analogue scale was significantly different between the groups. However, the mean score of disability caused by plaster cast immobilization and the incidence rate of shoulder pain were significantly higher in patients who had a long plaster cast. Our findings suggest that a short arm cast is as effective as a long arm cast for stable distal radius fractures in the elderly. Furthermore, it is more comfortable and introduces less restriction on daily activities.

LEVEL OF EVIDENCE

II.

Self-Assembled Silica Nanostructures: Simultaneous Discrimination of Handedness, Pitch and Diameter of Helical Silica Nanotubes

The left- and right-handed helical silica nanostructures were obtained with the aid of organic templates, the formation of the nanostructures might follow a co-operation self-assembly mechanism. The chirality of the organogel self-assemblies was successfully transcribed in to the silica. The helical pitch and pore size of the silica nanotubes sensitively depended on the optical purity of the neutral gelator in the reaction mixtures.

An ultra-low power (ULP) bandage-type ECG sensor for efficient cardiac disease management

This paper proposed an ultra-low power bandage-type ECG sensor (the size: 76 × 34 × 3 (mm(3)) and the power consumption: 1 mW) which allows for a continuous and real-time monitoring of a user's ECG signals over 24h during daily activities. For its compact size and lower power consumption, we designed the analog front-end, the SRP (Samsung Reconfigurable Processor) based DSP of 30 uW/MHz, and the ULP wireless RF of 1 nJ/bit. Also, to tackle motion artifacts(MA), a MA monitoring technique based on the HCP (Half-cell Potential) is proposed which resulted in the high correlation between the MA and the HCP, the correlation coefficient of 0.75 ± 0.18. To assess its feasibility and validity as a wearable health monitor, we performed the comparison of two ECG signals recorded form it and a conventional Holter device. As a result, the performance of the former is a little lower as compared with the latter, although showing no statistical significant difference (the quality of the signal: 94.3% vs 99.4%; the accuracy of arrhythmia detection: 93.7% vs 98.7%). With those results, it has been confirmed that it can be used as a wearable health monitor due to its comfortability, its long operation lifetime and the good quality of the measured ECG signal.

Donor-recipient sex mismatch in kidney transplantation

BACKGROUND

The lack of reliable human proxies for minor (ie, non-HLA) histocompatibility loci hampers the ability to leverage these factors toward improving transplant outcomes. Despite conflicting reports of the effect of donor-recipient sex mismatch on renal allografts, the association between acute rejection of renal allografts and the development of human alloantibodies to the male H-Y antigen suggested to us that donor-recipient sex mismatch deserved re-evaluation.

OBJECTIVE

To evaluate whether the relationships between donor sex and allograft failure differed by recipient sex.

METHODS

We studied recipients of deceased-donor (n = 125,369) and living-donor (n = 63,139) transplants in the United States Renal Data System. Using Cox proportional hazards models stratified by donor type, we estimated the association between donor-recipient sex mismatch and death-censored allograft failure with adjustment for known risk factors, with and without the use of multiple imputation methods to account for potential bias and/or loss of efficiency due to missing data.

RESULTS

The advantage afforded by male donor kidneys was more pronounced among male than among female recipients (8% vs 2% relative risk reduction; interaction P < 0.01). This difference is of the order of magnitude of several other risk factors affecting donor selection decisions.

CONCLUSIONS

Donor-recipient sex mismatch affects renal allograft survival in a direction consistent with immune responses to sexually determined minor histocompatibility antigens. Our study provides a paradigm for clinical detection of markers for minor histocompatibility loci.

The effects of femoral graft placement on in vivo knee kinematics after anterior cruciate ligament reconstruction

Achieving anatomical graft placement remains a concern in Anterior Cruciate Ligament (ACL) reconstruction. The purpose of this study was to quantify the effect of femoral graft placement on the ability of ACL reconstruction to restore normal knee kinematics under in vivo loading conditions. Two different groups of patients were studied: one in which the femoral tunnel was placed near the anterior and proximal border of the ACL (anteroproximal group, n=12) and another where the femoral tunnel was placed near the center of the ACL (anatomic group, n=10) MR imaging and biplanar fluoroscopy were used to measure in vivo kinematics in these patients during a quasi-static lunge. Patients with anteroproximal graft placement had up to 3.4mm more anterior tibial translation, 1.1mm more medial tibial translation and 3.7° more internal tibial rotation compared to the contralateral side. Patients with anatomic graft placement had motion that more closely replicated that of the intact knee, with anterior tibial translation within 0.8mm, medial tibial translation within 0.5mm, and internal tibial rotation within 1°. Grafts placed anteroproximally on the femur likely provide insufficient restraint to these motions due to a more vertical orientation. Anatomical femoral placement of the graft is more likely to reproduce normal ACL orientation, resulting in a more stable knee. Therefore, achieving anatomical graft placement on the femur is crucial to restoring normal knee function and may decrease the rates of joint degeneration after ACL reconstruction.

An equatorial pacific ocean source of atmospheric mercury

Pronounced increases in total gaseous mercury (TGM) in the near surface marine atmosphere were found in the equatorial region (4 degrees N to 10 degrees S) of the Pacific Ocean at 160 degrees W. The atmospheric enhancement of TGM corresponded closely to sea-surface manifestations of equatorial upwelling as reflected in measured changes of temperature and nutrient concentrations as well as to variations of reactive mercury in surface seawater. The elevated atmospheric TGM levels most probably result from oceanic mercury evasion associated with upwelling and increased biological production that occurs in the equatorial Pacific Ocean.This evidence of sea-to-air mercury transfer supports model predictions of an oceanic source of atmospheric mercury and suggests that marine-derived mercury emissions should occur in other biologically productive regimes.

Comparison of particle size spectrum determination from images made using manual and automated image analysis

A digital processing method is described for determining the size spectra of sub-micron particles in natural water from transmission electron microscopy images of particles collected by ultracentrifugation, and is compared with traditional manual counting and size measurement methods. The processing method is based on the use of the MatLab Image Processing toolbox. The manual method was found to underestimate the population of particles smaller than 40 nm equivalent radius, primarily because of a "fatigue factor" in counting the very large numbers of particles in this size range. By contrast, the manual method produced higher particle counts of particles >50 nm radius, primarily because manual counters tend to group together particles as aggregates that digital processing indicates are not contiguous. The digitally-produced size spectrum for a river water sample was found to closely follow a power-series law down to the smallest particle size.

Endoscopic submucosal resection with double ligation technique for treatment of small rectal carcinoid tumors

BACKGROUND AND STUDY AIMS

It is difficult to achieve complete endoscopic resection of rectal carcinoid tumors without any procedure-related complications. In this study, we evaluated the efficacy and safety of endoscopic submucosal resection with double ligation (ESMR-DL) for the treatment of small rectal carcinoid tumors.

PATIENTS AND METHODS

Eleven rectal carcinoid tumors (in 11 patients) were resected by ESMR-DL between November 2001 and April 2004, using a conventional single-channel endoscope with an attached band-ligator device. The lesion was aspirated into the ligator device and an elastic band was placed around the base; a detachable snare was then used to ligate the stalk below the elastic band; and snare resection was performed above the elastic band. The resected specimens were examined with respect to size, histological atypia, depth of invasion, and the histological appearance of the resection margins.

RESULTS

All the lesions were excised completely without any complications. There was no tumor invasion beyond the submucosal layer and there was no evidence of atypia in any of the specimens. Tumor diameter varied from 2.0 mm to 10.0 mm (average 6.2 mm). None of the 11 specimens showed histopathological evidence of tumor involvement at the resection margins. There were no immediate or late complications (bleeding or perforation) after ESMR-DL. There was no local recurrence and there were no distant metastases in any patients during the mean follow-up period of 18 months.

CONCLUSION

Endoscopic submucosal resection with double ligation is a useful and safe method for the treatment of small rectal carcinoid tumors.

Effect of the Tube Diameter Distribution on the High-Temperature Structural Modification of Bundled Single-Walled Carbon Nanotubes

We present results of a systematic high-resolution transmission electron microscopy study of the thermal evolution of bundled single-walled carbon nanotubes (SWNTs) subjected to approximately 4-h high-temperature heat treatment (HTT) in a vacuum at successively higher temperatures up to 2200 degrees C. We have examined purified SWNT material derived from the HiPCO and ARC processes. These samples were found to thermally evolve along very different pathways that we propose depend on three factors: (1) initial diameter distribution, (2) concomitant tightness of the packing of the tubes in a bundle, and (3) the bundle size. Graphitic nanoribbons (GNR) were found to be the dominant high-temperature filament in ARC material after HTT = 2000 degrees C; they were not observed in any heat-treated HiPCO material. The first two major steps in the thermal evolution of HiPCO and ARC material agree with the literature, i.e., coalescence followed by the formation of multiwall carbon nanotubes (MWNTs). However, ARC material evolves to bundled MWNTs, while HiPCO evolves to isolated MWNTs. In ARC material, we find that the MWNTs collapse into multishell GNRs. The thermal evolution of these carbon systems is discussed in terms of the diameter distribution, nanotube coalescence pathways, C-C bond rearrangement, diffusion of carbon and subsequent island formation, as well as the nanotube collapse driven by van der Waals forces.

Thermal conversion of bundled carbon nanotubes into graphitic ribbons

High temperature heat treatment (HTT) of bundled single-walled carbon nanotubes (SWNTs) in vacuum ( approximately 10(-5) Torr) has been found to lead to the formation of two types of graphitic nanoribbons (GNRs), as observed by high-resolution transmission electron microscopy. Purified SWNT bundles were first found to follow two evolutionary steps, as reported previously, that is, tube coalescence (HTT approximately 1400 degrees C) and then massive bond rearrangement (HTT approximately 1600 degrees C), leading to the formation of bundled multiwall nanotubes (MWNTs) with 3-12 shells. At HTT > 1800 degrees C, we find that these MWNTs collapse into multishell GNRs. The first type of GNR we observed is driven by the collapse of diameter-doubled single-wall nanotubes, and their production is terminated at HTT approximately 1600 degrees C when the MWNTs also start to form. We propose that the collapse is driven by van der Waals forces between adjacent tubes in the same bundle. For HTT > 2000 degrees C, the heat-treated material is found to be almost completely in the multishell GNR form.

Developing products for personalized medicine: NIH Research Tools Policy applications

For innovators at academic or industrial institutions to develop personalized medicine products at the accelerated pace required, rapid access to state-of-the-art research tools and reagents are needed. Unreasonable restrictions or delays in the use of such tools may undermine the development of these customized diagnostics and therapeutic products designed to provide significant treatment benefits to patients who frequently do not benefit from traditional therapeutic approaches. In its funding agreements and its own internal research programs, the National Institutes of Health is implementing policies to facilitate the exchanges of these research tools and related resources.

Distribution and licensing of drug discovery tools--NIH perspectives

Now, more than ever, drug discovery conducted at industrial or academic facilities requires rapid access to state-of-the-art research tools. Unreasonable restrictions or delays in the distribution or use of such tools can stifle new discoveries, thus limiting the development of future biomedical products. In grants and its own research programs the National Institutes of Health (NIH) is implementing its new policy to facilitate the exchanges of these tools for research discoveries and product development.

Typing of clinical isolates of Mycobacterium leprae and their distribution in Korea

Although there is no genetic diversity in isolates of Mycobacterium leprae, the variance of tandem repeats in the rpoT gene was recently demonstrated. We have typed clinical isolates of M. leprae in Korea using difference of the tandem repeats in the rpoT gene. Among 69 patients, 65 Korean isolates (94.2%) demonstrated four copies of the 6 bp tandem repeat (GACATC) in the rpoT gene, and incidences of three copies were found in only two Koreans and two foreigners (2.9%, respectively).

Genotypic prevalence of the fimbrial adhesins (F4, F5, F6, F41 and F18) and toxins (LT, STa, STb and STx2e) in Escherichia coli isolated from postweaning pigs with diarrhoea or oedema disease in Korea

A PCR was used to determine the genotypic prevalence of five fimbrial adhesins (F4, F5, F6, F41 and F18), two heat-stable enterotoxins (STa and STb), the heat-labile enterotoxin (LT), and the shiga toxin 2e (Stx2e) in 230 isolates of Escherichia coli from postweaning pigs with diarrhoea or oedema disease. Ninety-four (40.9 per cent) of the isolates carried genes for at least one of the fimbrial adhesins or toxins. Genes for the F18 fimbrial adhesin were detected in 18.3 per cent, and genes for F4, F6, F5 and F41 were detected in 10.0 per cent, 4.3 per cent, 1.7 per cent and 0.8 per cent of the isolates, respectively. Genes for STa, STb and LT were detected in 25.7 per cent, 15.2 per cent and 8.7 per cent of the isolates, respectively. Genes for Stx2e were detected in 36 (15.6 per cent) of the isolates, and among them 24 also contained the gene for F18ab and four also contained the gene for F18ac.

Molecular cloning and characterization of mouse cardiac triadin isoforms

Triadin is a ryanodine receptor and calsequestrin binding protein located in junctional sarcoplasmic reticulum of striated muscles. In the present study, mouse cardiac triadin cDNAs have been identified by cDNA library screening and RT-PCR. The deduced aa sequences show that the three isoforms consist of 277, 293 and 305 aa giving rise to the molecular weights of approximately 31,414, 33,066, and 34,328, respectively. The isoforms have identical 262 aa N-terminal sequences, whereas they have distinct C-terminal sequences. Northern blot analysis using a cDNA probe representing the N-terminal common region of triadin revealed that the mouse triadins were present both in heart and skeletal muscles. The estimated sizes of the transcripts were approximately 1.3, 4.3 and 5 kb in heart and 5, 5.5 and 7 kb in skeletal muscle. Endo H treatment and Western blot analysis of isolated mouse cardiac sarcoplasmic reticulum and in vitro translation products indicate that there are three distinct mouse cardiac triadin isoforms having molecular weights of 35, 35.5 and 40 kDa. We termed those three isoforms as mouse cardiac triadin 1, mouse cardiac triadin 2 and mouse cardiac triadin 3.

Prolonged organ retention and safety of plasmid DNA administered in polyethylenimine complexes

Polyethylenimine (PEI) has been studied as an efficient nonviral gene transfer vector. Here, we report the biodistribution fates and safety of plasmid DNA intravenously administered in PEI complexes. Using pCMVbeta as a model gene, the biodistribution of plasmid DNA was measured by quantitative polymerase chain reaction. A deletion mutant of pCMVbeta was used as an internal standard. After intravenous administration of PEI/DNA complexes, the serum levels of DNA rapidly declined for up to 15 min. However, after this point, the serum levels of DNA diminished slowly. At 15 min after dose, PEI/DNA complexes showed 33-fold higher distribution of DNA in the lung than did naked DNA. At 24 h, all the organs tested showed much higher levels of plasmid DNA in PEI/DNA complexes, with distribution in the liver and lung being three orders of magnitude higher than naked DNA. The mRNA expression of DNA was observed in various organs of PEI/DNA-treated mice at 12 days after dose. Once a week dosing of PEI/DNA complexes over 3 consecutive weeks did not alter the histology of the organs. However, twice a week dosing over 3 weeks induced a sign of inflammation in the liver. These results indicate that PEI enhances the delivery and retention of plasmid DNA in the organs, especially the liver, but that safe delivery requires proper dosing intervals.

Influence of the number of lymph nodes examined on staging of gastric cancer

BACKGROUND

Nodal staging for gastric cancer according to the 1997 Union Internacional Contra la Cancrum tumour node metastasis classification is based on the number of metastatic lymph nodes. The aim of this study was to evaluate whether the number of lymph nodes examined affected staging of gastric cancer.

METHODS

A retrospective study was performed in 4789 consecutive patients with gastric cancer, who had undergone curative resection (R0) from 1986 to 1995. Patients were classified according to the number of nodes examined. The number of metastatic lymph nodes and stage-stratified survival were compared.

RESULTS

There were significant differences in the number of metastatic lymph nodes and survival in stage IIIA between patients with 15 or more lymph nodes and those with fewer than 15 nodes. In analysis restricted to patients with 15 or more nodes, stage-stratified survival did not vary significantly with lymph node yields for any stage except IIIB, in which there was a significant difference between the subgroup with fewer than 20 examined lymph nodes and patients with 35 or more nodes.

CONCLUSION

The number of lymph nodes examined did not significantly affect node staging of gastric cancer as long as at least 15 nodes were examined. For stage IIIB, more than 15 lymph nodes may be required for optimal staging.

Results of immunochemo-surgery for gastric carcinoma

BACKGROUND/AIMS

Although the therapeutic results of gastric cancer have markedly improved, it still remains the most common cancer death in Korea.

METHODOLOGY

The clinicopathologic characteristics were analyzed for 11,491 consecutive patients who underwent operation for gastric cancer at the Department of Surgery, Seoul National University Hospital from 1971 to 1997. We also evaluated the survival and prognostic factors for 9,262 consecutive patients from 1981 to 1996. The prognostic significance of treatment modality [surgery alone, surgery + chemotherapy, surgery + immunotherapy + chemotherapy (immunochemo-surgery)] were evaluated in stage III gastric cancer.

RESULTS

The 5-year survival rate of overall patients was 55.8%, and that of patients who received curative resection was 64.8%. The 5-year survival rates according to TNM stage were 92.9% for Ia, 84.2% for Ib, 69.3% for II, 45.8% for IIIa, 29.6% for IIIb and 9.2% for IV. Depending on the extent of resection, the 5-year survival rates were 68.7% for STG, 45.4% for TG, 19.6% for combined resection and there was no 5-year survivor in the nonresection group. Regarding adjuvant treatment modality, significant survival difference was observed in stage III patients. The 5-year survival rates were 44.8% for the immunochemo-surgery group, 36.8% for the surgery + chemotherapy group and 27.2% for the surgery alone group.

CONCLUSIONS

Curative resection, depth of invasion and lymph node metastasis were the most significant prognostic factors in gastric cancer. Consequently, early detection and curative resection with radical lymph node dissection, followed by immunochemotherapy especially in patients with stage III gastric cancer should be recommended as a standard treatment principle for patients with gastric cancer.

Nasal absorption and biodistribution of plasmid DNA: an alternative route of DNA vaccine delivery

Nasal administration is emerging as a new route of DNA vaccine delivery. We aimed to study the extent of absorption and biodistribution of intranasally administered plasmid DNA. After intranasal administration, the level of plasmid DNA in the serum peaked at 1.5 h. The ratio of the area under the concentration (AUC) after intranasal administration of DNA over the AUC after intravenous administration was 0.14. At 15 min post inoculation, the highest organ distribution was observed in the liver and the cervical lymph nodes showed the highest level among the lymph nodes. At 24 h a higher localization of plasmids to the brain than to the lung and spleen was notable. A significant level of mRNA expression was observed in the lymph nodes. These results suggest that plasmid DNA can be substantially absorbed and distributed to the lymph nodes after intranasal administration, partly explaining the systemic immunogenicity of intranasally administered plasmid DNA vaccines.

Ellagic acid rhamnosides from the stem bark of Eucalyptus globulus

Four ellagic acid rhamnosides were isolated from the stem bark of Eucalyptus globulus. Their structures have been established on the basis of the analysis of their 1H NMR, 13C NMR, HMBC, IR and MS spectral data. The HMBC data of these compounds were most useful for their structure determinations, with these bring determined to be 3-O-methylellagic acid 3'-O-alpha-rhamnopyranoside, 3-O-methylellagic acid 3'-O-alpha-3''-O-acetylrhamnopyranoside, 3-O-methylellagic acid 3'-O-alpha-2''-O-acetylrhamnopyranoside, 3-O-methylellagic acid 3'-O-alpha-4''-O-acetylrhamnopyranoside, respectively. Their antioxidant activities were evaluated by measuring the inhibition of lipid peroxidation using rat liver microsomes, with IC50 values of 10.0-14.0 microg/ml.

A Clinicopathological Analysis of Recurrent Gastric Cancer

PURPOSE

This study was designed to investigate the correlation between the clinicopathologic characteristics and the recurrence pattern of gastric cancer and to define survival difference according to treatment modality after diagnosis of recurrence.

MATERIALS AND METHODS

We retrospectively reviewed the medical records of 4184 patients who had undergone radical surgery for primary gastric cancer from 1986 through 1996. Clinicopathologic factors were analyzed for the relationship of each factor with the pattern of recurrence. And the survival after diagnosis of recurrence was compared among the treatment modalities.

RESULTS

Recurrence pattern was confirmed in 1141 patients. Loco-regional recurrence occurred in 291 patients (20.1%), peritoneal recurrence in 383 (26.5%), distant recurrence in 290 (20.1%), and mixed recurrence in 177 (12.3%), respectively. Early recurrence (less than 2 years) occurred in 767 (69.3%), intermediate recurrence (2~5 years) in 286 (25.8%), and late recurrence (more than 5 years) in 54 (4.9%). In multivariate analysis, T stage, N stage, size of tumor and perineural invasion were independent prognostic factors for recurrence. Median survival from diagnosis of recurrence was 24.2 months in the curative operation group, 7.7 months in the chemotherapy group, 7.1 months in the non-curative operation group and 3.3 months in the conservative treatment group, respectively (p=0.000).

CONCLUSION

The clinicopathological analysis of recurrent gastric cancer showed recurrent patterns and prognostic factors. Curative resection is suggested to have survival benefit in recurrent gastric cancer patients, although it was possible in patients with limited extent of disease.

Nitric oxide mediates platelet activating factor-induced microvascular leakage in rat airways

Platelet activating factor (PAF), a highly potent chemical mediator in inflammation and allergic reactions, induces microvascular leakage in several tissues. In rat airways, PAF-induced microvascular leakage is probably mediated by an endothelial cell receptor in the microvessels. Nitric oxide (NO), first identified as endothelium-derived relaxing factor, has been suggested to be a mediator of airway microvascular leakage. However, the role of NO in PAF-induced microvascular leakage in the airways has not yet been established. The aim of this study was to investigate the role of NO in PAF-induced microvascular leakage in rat nasal mucosa and trachea. We injected PAF (1 microg/kg) intravenously, and the amount of PAF-induced microvascular leakage was measured with extravasation of Evans blue dye (30 mg/kg, injected intravenously 5 minutes before the injection of PAF) by means of spectrophotometry and fluorescence microscopy. Five Sprague-Dawley rats were pretreated with NG-nitro-L-arginine methyl ester (L-NAME; 10 mg/kg, intravenously injected 1 hour before the injection of PAF) to inhibit NO synthase, and control rats (n = 4) were pretreated with normal saline solution. The average amount of extravasated Evans blue dye was significantly lower in the L-NAME-pretreated rats than in the control rats (t-test, p < .01). Tissue sections of the L-NAME-pretreated rats clearly showed a decreased extravasation of Evans blue dye on fluorescence microscopy. In conclusion, pretreatment with L-NAME clearly inhibited PAF-induced microvascular leakage in the nasal mucosa and trachea of rats. This finding implies that PAF may activate the constitutive endothelial NO synthase in the microvessels, and that activated endogenous NO may mediate PAF-induced microvascular leakage in rat airways.

Methyl mercury bioaccumulation in long-finned eels, Anguilla dieffenbachii, from three rivers in Otago, New Zealand

This research focuses on mercury (Hg) bioaccumulation in New Zealand long-tinned eels (Anguilla dieffenbachii) from the aquatic environment. Total Hg (HgT) and methyl mercury (MeHg) concentrations were determined in muscle tissue from eels living in three South Island rivers dominated respectively by urban, native bush and agricultural land-uses. Most of the Hg in eels was MeHg (> 84%) and the MeHg concentrations increased linearly with both length and eel age for a given river habitat. The annual growth rates for eels from the urban and agricultural streams were greater than for eels from the native bush stream. The average MeHg accumulation rate was significantly higher for the eels in the agricultural stream compared with either the urban or native bush catchments. These results are probably due to a combination of factors and further investigations in the lower food web are necessary to elucidate the exact mechanisms of MeHg bioaccumulation in these creatures.

Multiplex in-cell reverse transcription-polymerase chain reaction for the simultaneous detection of p210 and p190 BCR-ABL mRNAs in chronic myeloid leukemia and Philadelphia-positive acute lymphoblastic leukemia cell lines

We designed a novel multiplex in-cell reverse transcription-polymerase chain reaction method for the simultaneous detection and differentiation of p190 and p210 BCR-ABL mRNAs within single cells from the human chronic myeloid leukemia and Philadelphia positive acute lymphoblastic leukemia. Human K562 chronic myeloid leukemia and SUP B-15 Ph+ acute lymphoblastic leukemia cell lines were used as positive controls for p210 and p190 BCR-ABL mRNAs, respectively. HL60 cell line was used as a negative control. After the leukemia cells were fixed and permeabilized, without extracting nucleic acids, the mRNAs were reverse transcribed to cDNAs, and the cDNAs were amplified by multiplex polymerase chain reaction with fluorescent primers specific for p190 and p210 BCR-ABL mRNAs. After transfer onto glass slides by cytospin, the amplified cells were detected by fluorescence microscopy. Fluorescence microscopy after propidium iodide or 4',6-diamidino-2-phenylindone counterstaining showed that the positive K562 cells exhibited a yellow-green fluorescent cytoplasm around a red nucleus, and that the positive SUP B-15 cells exhibited an orange cytoplasm around a blue nucleus. Only the red or blue nucleus was visible in respective negative HL60 cells. The specificity of amplification was confirmed by the absence of a signal when control experiments were performed either with RNase digestion of mRNA or without reverse transcriptase/Taq polymerase. We conclude that the multiplex in-cell reverse transcription-polymerase chain reaction method is capable of simultaneously detecting and differentiating the p210 and p190 BCR-ABL mRNAs of chronic myeloid leukemia and Philadelphia-positive acute lymphoblastic leukemia cells, and that it may be useful in quantitatively monitoring the minimal residual disease during therapy.

Microsatellite instability and Epstein-Barr virus infection in gastric remnant cancers

Clinicopathological analysis, microsatellite analysis, detection of Epstein-Barr virus (EBV), and immunohistochemistry on p53 protein were performed in 26 cases of gastric remnant cancer (GRC). They were divided into two groups; Group A (n = 14) who had undergone a primary gastrectomy for benign gastric disease, and Group B (n = 12) who had undergone the same operation for gastric cancer. EBV infection was present in 29% of Group A, 8% of Group B and 6% of the conventional gastric carcinoma (CGC) (Group A vs CGC, P = 0.01). Microsatellite instability (MSI) was found in 7% of Group A, 25% of Group B, and 9% of the CGC (Group B vs CGC; P = 0.08). p53 Overexpression was observed in 46% of the GRC and 33% of the CGC. p53 Overexpression was observed in 90% of the intestinal type of GRC, but in only 20% of the diffuse type of GRC (P = 0.002). The cancer stage was a significant factor in the univariate analysis of survival (P = 0.04). In conclusion, GRC is different from CGC in terms of MSI or EBV association. The pathogenetic differences between the two groups require further investigation. EBV infection may have been involved in the carcinogenesis of Group A. MSI may be an important factor in the carcinogenesis of metachronous multiple gastric cancer (Group B).

Result of 11,946 gastric cancer treatment with immunochemosurgery

Although the therapeutic results of gastric cancer have markedly improved, it still remains the most common of cancer deaths in Korea. Annually more than 700, and all together 11,946, gastric cancer patients were surgically treated from 1970 to 1998 at Seoul National University Hospital. Stage III gastric cancer is already a systemic disease, Radical surgery alone cannot cure the patient, and about 35% recurred within 2-3 years. To improve the prognosis of advanced gastric cancer, systemic treatment such as immunotherapy and chemotherapy is required in the early postoperative period to kill the micrometastatic or remaining cancer cells after curative resection. We evaluated the survival rate and prognostic factors for 9,262 consecutive patients from 1981 to 1996. The clinicopathologic variables used for evaluating prognostic values were classified into patient, -tumor- and treatment-related factors. The prognostic significance of treatment modality was evaluated in stage III gastric cancer. The five-year survival rates were 55.9% for overall patients and 64.8% for patients who received curative resection. Radical lymph node dissection was found to produce survival gains in patients with stage II and IIIa. For postoperative adjuvant therapy, immunochemotherapy was most effective in patients with stage III. In multivariate analysis, curability of operation, depth of invasion, and ratio of involved-to-resected lymph nodes were the significant prognostic factors. Consequently, early detection and real curative resection with radical lymph node dissection, followed by immunochemotherapy (particularly in patients with stage III gastric cancer) should be recommended as a standard treatment principle for patients with gastric cancer.

Lipid peroxidation inhibitory activity of some constituents isolated from the stem bark of Eucalyptus globulus

Twelve compounds with lipid peroxidation inhibitory activity were isolated from the stem bark of E. globulus. Their structures were assigned as a new aromatic monoterpene (1) and eleven known compounds, pinoresinol (2), vomifoliol (3), 3,4,5-trimethoxyphenol 1-O-beta-D-(6'-O-galloyl)glucopyranoside (4), methyl gallate (5), rhamnazin (6), rhamnetin (7), eriodictyol (8), quercetin (9), taxifolin (10), engelitin (11), and catechin (12) on the basis of UV, mass, and NMR spectroscopic analyses. These compounds except vomifoliol significantly inhibited lipid peroxidation in rat liver microsome.

Antiphotooxidative activity of protoberberines derived from Coptis japonica makino in the chlorophyll-sensitized photooxidation of oil

Antiphotooxidative components were isolated from the methanolic extract of Coptis japonica Makino by liquid-liquid partitioning fractionation, subsequent column chromatography on Sephadex LH-20 and silica gel, and preparative silica gel TLC. The isolated compounds were identified as coptisine, jatrorrizhine, berberine, and magnoflorine by a combination of spectroscopic studies using UV-visible, IR, mass-spectrometry, and NMR. Coptisine, jatrorrizhine, and berberine isolated from Coptis japonica Makino showed strong antiphotooxidative activity in the chlorophyll-sensitized photooxidation of linoleic acid. However, these compounds did not show either inhibitory activity against lipid peroxidation in rat liver microsomes nor DPPH radical scavenging activity, indicating that their antiphotooxidative activity was not due to the radical chain reaction breaking ability but due to singlet oxygen quenching activity. Commercially available authentic protoberberines (berberine chloride and palmatine chloride) also showed strong antioxidative activity in the chlorophyll-sensitized photooxidation of linoleic acid. The antiphotooxidative activities of the berberine chloride and palmatine chloride were significantly higher than that of ascorbyl palmitate in the chlorophyll-sensitized photooxidation of linoleic acid. These results clearly showed for the first time the antiphotooxidative properties of protoberberines in chlorophyll-sensitized photooxidation of oil.

Curtisians A-D, new free radical scavengers from the mushroom Paxillus curtisii

In our continuous investigation for free radical scavengers from extracts of fruit body of basidiomycetes, we have isolated four new p-terphenyl compounds, designated as curtisians A-D, from the methanolic extract of the fruit body of Paxillus curtisii. These compounds were isolated by silica gel and Sephadex LH-20 column chromatographies, preparative-TLC and HPLC, consecutively. The structures of curtisians were assigned as p-terphenyls with substituents of acetyl, benzoyl, phenylbutyryl, 3-hydroxybutyryl and 3-acetoxybutyryl. Curtisians A, B, C and D exhibited inhibitory activity against lipid peroxidation with IC50, values of 0.15, 0.17, 0.24 and 0.14 microg/ml, respectively.

Two new genotypes of Plasmodium vivax circumsporozoite protein found in the Republic of Korea

The gene encoding Plasmodium vivax circumsporozoite protein (PvCSP) exhibits polymorphism in many geographical isolates. The present study was designed to investigate polymorphism in PvCSP gene of P. vivax isolates in Korea. Thirty isolates, obtained from indigenous cases in Yonchon-gun, Kyonggi-do in 1997, were subjected for sequencing and RFLP analysis of the repeat and post-repeat regions of PvCSP gene and two genotypes (SK-A and SK-B) were identified. The genotype of 19 isolates was SK-A and that of 11 isolates was SK-B. Although the number of 12-base repeats present in SK-A was three while two were found in a Chinese strain CH-5, the repeat sequence of SK-A was identical to that of CH-5 except for one base substitution. Compared with known data there was no identical isolates with SK-B, but the sequence of SK-B was similar to that of a North Korean (NK) isolate. These results indicate that two genotypes of PvCSP coexist in the present epidemic area of Korea and the present parasite may originate from East Asia. RFLP would be useful to classify genotypes of P. vivax population instead of gene sequencing.

Management of complex breast cysts

OBJECTIVE

This study was undertaken to evaluate the various strategies currently in use to manage complex cysts and specifically address the need for intervention.

MATERIALS AND METHODS

A review of 4562 breast sonograms obtained during an 18-month period revealed 308 complex cysts in 252 women. Data collected from review of patient records included the patient's age and risk factors for breast cancer, aspiration or biopsy results (or both), follow-up imaging studies, and management recommendations.

RESULTS

Management recommendations for complex cysts were 1-year follow-up in 13 patients, 6-month follow-up in 148, sonographically guided aspiration in 82, aspiration with possible core biopsy in 62, and excisional biopsy in three. No malignancies were diagnosed in the group treated with follow-up imaging, sonographically guided aspiration, or excisional biopsy. One malignancy, a papilloma with a 3-mm focus of ductal carcinoma in situ, was diagnosed in one of the patients who underwent core biopsy.

CONCLUSION

Of the lesions classified as complex cysts, the malignancy rate was 0.3% (1/308). This malignancy rate is lower than that for lesions classified as probably benign using mammographic criteria (i.e., for lesions classified as category 3 lesions using the Breast Imaging Reporting and Data System). Because the accepted standard practice for management of probably benign lesions is follow-up studies, the low yield of malignancy in this series suggests that complex cysts can be managed with follow-up imaging studies instead of intervention.

Detection of methylation damage in DNA of gastric cancer tissues using 32P postlabelling assay

Gastric cancer is the most common cancer in Korea. The causes are still unknown but it has been speculated that gastric cancer is associated with consumption of foods rich in nitrates/nitrites or a high dietary intake of salt or pickled food. In the present study, we studied the level of alkylated DNA adducts formed in gastric cancer tissues in comparison with that in normal gastric mucosa. DNA was extracted from surgically removed gastric cancer tissues and patient-matched normal gastric mucosa. The level of N7-methyldeoxyguanosine was measured by 32P-postlabelling assay after high performance liquid chromatography (HPLC) enrichment. We found that the level of N7-methyldeoxyguanosine of gastric cancerous tissues was significantly higher than that of normal gastric mucosa (P=0.01685).

Surgical results in gastric cancer

Although the therapeutic results for gastric cancer have markedly improved, it remains the most common cause of cancer death in Korea. Annually, at Seoul National University Hospital, over 700 gastric cancer patients are surgically treated, and, between the years from 1970 and 1997, a total of 11,491 such patients were treated. We will review the principles of surgery for gastric cancer and our comparative studies of immunochemosurgery and postoperative chemotherapy. Further, we will review our evaluation of the survival rate and prognostic factors for 9,262 patients from 1981 to 1996. We conclude that the most important factors for improvement of the postoperative survival of these patients are early diagnosis and curative resection with radical lymph node dissection, followed by postoperative immunochemotherapy. This should be recommended as the standard treatment for patients with gastric cancer, especially patients with Stage III gastric cancer.

Prognostic factors in 2230 Korean colorectal cancer patients: analysis of consecutively operated cases

To define the prognostic factors in Korean colorectal cancer patients, univariate and multivariate analysis were performed on data from 2230 consecutive patients who underwent resection for colorectal cancer at the Seoul National University Hospital. The prognostic variables used for the analysis included patient's age, gender, bowel obstruction, bleeding, symptom duration, preoperative leukocyte count, preoperative serum carcinoembryonic antigen (CEA) level, Dukes' stage, tumor location, tumor size, depth of bowel wall invasion, number of lymph node metastases, histologic differentiation, and gross morphology of tumor. The overall 5-year survival rate was 62%. In the univariate analysis, all the factors except sex, symptom duration, and tumor size were associated with prognosis. Among the factors significant in the univariate analysis, Dukes' stage (p < 0.001), number of lymph node metastasis (p < 0.001), CEA level (p < 0.001), tumor location (p = 0.003), gross morphology of tumor (p = 0.017), and depth of bowel wall invasion (p = 0.031) were significant in the multivariate analysis. Several differences in prognostic factors between colon cancer and rectal cancer were observed. In the multivariate analysis, gross tumor morphology was significant only for colon cancer, and histologic differentiation was significant only for rectal cancer. Lymph node metastasis was an independent prognostic variable for both colon and rectal cancer, but its significance was more prominent for rectal cancer. Although Dukes' stage is the most reliable prognostic predictor, this study shows that other factors (preoperative CEA level, gross morphology of tumor, location of tumor, nodal status) also provide important information for the outcome of the patient.

Experimental infection of chimpanzees with hepatitis G virus and genetic analysis of the virus

Hepatitis G virus (HGV) was transmitted to 2 chimpanzees by inoculation with human plasma containing approximately 10(8) genome equivalents (GE) of HGV. The infection was characterized by the late appearance (weeks 10 and 11 after inoculation [pi]) of viremia that persisted throughout the 120-week follow-up. Serum HGV titer increased steadily until it plateaued at 10(6)-10(7) GE/mL. However, despite this relatively high titer, neither of the chimpanzees developed hepatitis. The sequence of the viral genome, recovered from each chimpanzee at week 77 pi, differed from that of the inoculum by 5 nt (2 aa) and 27 nt (2 aa). Two more chimpanzees were inoculated with a first-passage plasma pool. The chimpanzee inoculated with approximately 10(6.7) GE of HGV had viremia at week 1 pi. However, the viral titer increased with the same kinetics as observed in the first passage. The second chimpanzee inoculated with approximately 10(4.7) GE of HGV had late appearance (week 7 pi) of viremia.

Nutritional status of gastric cancer patients after total gastrectomy

A number of causes of malnutrition after total gastrectomy have been proposed. The purpose of this study was to assess nutritional status and to determine the cause of malnutrition after total gastrectomy. We studied 20 gastric cancer patients who had undergone total gastrectomy and immunochemotherapy and 6 normal controls. Nutritional status was assessed by dietary history, anthropometric methods, and serologic measurements. Malabsorption tests included the fecal fat excretion test, D-xylose absorption test, glucose tolerance test, vitamin B12 absorption test using dual isotopes, bacterial culture of jejunal aspirates, and jejunal biopsy. Weight loss was compared to the preoperative status in all patients (average 15%: 59.0 +/- 9.9 vs. 50.2 +/- 7.8 kg, preoperatively vs. postoperatively). Average daily calorie intake was 1586.2 kcal, which is lower than the normal intake of Korean adults (1838 kcal). Malnutrition of skeletal and visceral protein was not found. There was, however, severe fat malnutrition and a deficit of body fat. Postoperatively the body mass index was considerably lower than that preoperatively (22.2 +/- 0.4 vs. 18.9 +/- 0.4 kg/m2; preoperatively vs. postoperatively). With malabsorption tests, the daily excreted amount of fecal fat was 28.6 +/- 3.4 g (mean +/- SD) in patients and 6.9 +/- 0.2 g in controls. There was no significant malabsorption of carbohydrates. In 64.3% (9/14) of patients, vitamin B12 absorption was abnormal; and the serum concentration of vitamin B12, which was significantly related to malabsorption of this vitamin, was lower than normal in 73.7% (14/19). Bacterial overgrowth was not found, and there were no abnormal histologic findings in the jejunal mucosa. These results suggest that poor oral intake and fat malabsorption following total gastrectomy cause malnutrition and that fat malabsorption may be related to relative pancreatic insufficiency.