Clinical Sequalae of Initial Insurance Denials in a Large Academic Radiation Oncology Center

PURPOSE/OBJECTIVE(S)

The objective of this study is to investigate the clinical sequalae of initial radiation oncology insurance denials. The hypothesis is that while the majority of initial insurance case denials are ultimately overturned, there are potential clinical implications to these initial denials.

MATERIALS/METHODS

Data were extracted from an institutional registry of patient cases initially denied authorization by their insurers from January 2022 to December 2022. Chi-Square tests using statistical software were employed.

RESULTS

Two hundred six cases from November 2021 to December 2022 were identified. The majority (n = 199 [96.6%]) of insurers were commercial payers, while 7 (3.4%) were Medicare/Medicare Advantage. 161 (78.1%) patients were <65 years of age, and 45 (21.8%) 65 or older. One hundred forty-one (68.4%) cases were metastatic, 60 (29.1%) definitive, and 5 (2.4%) were recurrent. Of the 206 cases, 127 (61.6%) cases were ultimately successful in authorization of the ordered treatment without any change to the requested treatment technique or prescription dose after P2P (Peer to Peer review), second-level appeal, comparison plan submission, employer request, insurance carrier change, and/or external appeal, and 56 (27.2%) cases were authorized though with insurer-requested modification to radiation treatment technique and/or prescription dose. Of 21 cases with a requested change in prescription dose, the median decrease in biologically effective dose (BED) was 24 Gy (range: 2.3-51). Of 58 cases with requested change in RT technique, 20 (34.5%) changed from IMRT to 3D-CRT, 16 (27.6%) SBRT to 3D, 15 (25.9%) SBRT to IMRT, 6 (10.3%) SBRT to 2D, and 1 (1.7%) 3D-CRT to 2D. 19 (9.2%) cases remained unauthorized by the insurer but proceeded with treatment via departmental administrative clearance. Of 196 cases which went on to treatment, 72 (36.7%) cases were delayed for a mean of 7.8 days and median of 5 days (range: 1-49). P2P was performed by the treating radiation oncologist in 169 (82.0%) cases, of which 78 (46.1%) were successful in authorization of the ordered treatment. Of the 91 unsuccessful cases, 62 (68.1%) second-level appeals were performed, of which 39 (62.9%) were successful in overturning denied authorization. Of the 23 cases not authorized either through P2P or second-level appeal, 3 (13.0%) cases were successful in authorization of the requested treatment via employer request, external appeal through an independent review organization, or insurance carrier change.

CONCLUSION

Our institutional analysis suggests that while the majority of initial insurance case denials are ultimately overturned without any change to the requested treatment technique or prescription dose through a number of requests made by the insurer to the radiation oncologist, there are clinical implications with a significant percentage of case denials leading to treatment delays, decrease in prescription BED, and less conformal treatment technique.

Prospective, Cell-Free Circulating Tumor DNA (ctDNA) Profiling in Locally Advanced Lung Cancer Treated with Chemoradiation

PURPOSE/OBJECTIVE(S)

Liquid biopsy for cell-free circulating tumor DNA (ctDNA) allows for non-invasive, comprehensive genomic profiling. We explored the utility prospective liquid biopsy for (ctDNA) in among non-small cell lung cancer (NSCLC) patients treated with definitive chemoradiation.

MATERIALS/METHODS

This prospective clinical cohort consists of unresectable, locally advanced NSCLC patients who had liquid biopsy testing prior to initiation of cancer therapy. Liquid biopsy testing was performed using a next-generation sequencing assay (MSK-ACCESS) which includes 129 genes and paired white blood cell sequencing. An FDA-recognized database (OncoKB) was utilized to classify alterations associated with radiation resistance (including KEAP1, NFE2L2, STK11, and PIK3CA) and radiation sensitivity (including ATM, ATR, BRCA1/2, ARID1A, MLH1 and other DNA Damage Repair Pathway alterations). We evaluated progression-free survival (PFS) from the completion of chemoradiation using the Log-rank test.

RESULTS

Among 25 patients with prospective ctDNA testing prior to therapy initiation, 17 patients had stage III disease (68%), 8 patients had stage II disease (32%), 18 patients had adenocarcinoma (72%), 7 patients had squamous cell carcinoma (28%), and 23 (92%) were former or current smokers. The median radiation dose was 60 Gy in 30 fractions (range: 55 to 66 Gy in 20 to 33 fractions). 76% of patients (n = 18) had one or more alterations detected (median: 3 alterations, range: 1 - 8) including genomic markers of radiation response in 2 patients in BRCA1/2 (n = 2) and radiation resistance in 1 patient in KEAP1. The most common driver alteration detected was KRAS in 24% of the cohort (n = 6). Among patients with baseline detectable ctDNA, the median PFS was 21.3 months and was not reached among patients without baseline ctDNA detection (HR 4.54, p = 0.04).

CONCLUSION

Using an institutional assay, the presence of baseline cell-free ctDNA appeared prognostic in patients with unresectable, locally advanced NSCLC treated with definitive chemoradiation. We also detected driver alterations and potential markers of radiation resistance and response using ctDNA testing. Prospective cell-free ctDNA profiling may offer pathways to therapy personalization among patients with locally advanced unresectable lung cancer.

Association between non-vascularised bone graft failure and compartment of the defect in mandibular reconstruction: a systematic review and meta-analysis

Controversy exists regarding the influence of the graft placement site in the mandible on the success of non-vascularised bone grafts. In this study, we examine the association between the compartment of the mandibular defect and the bone graft failure rate. A systematic literature review and meta-analysis was performed using MEDLINE, Embase, and Cochrane databases. Failure rates according to the compartment of mandibular defect were extracted and analysed by meta-analysis. The Newcastle-Ottawa Scale was used to assess the quality of the studies, and publication bias was evaluated using funnel plots. The search strategy identified 27 publications. After screening, five were selected for review. Based on the result of comparison among these five, we found no significant statistical association between the bone graft failure rate and compartment of mandibular defect, although further investigation of prospective randomised cohort studies is required.

3334Updated meta-analysis of biodegradable polymer drug-eluting stent versus second-generation durable polymer drug-eluting stent implantations

Background

Data regarding clinical outcomes of biodegradable polymer drug-eluting stent (BP-DES) versus second-generation durable polymer drug-eluting stent (DP-DES) in patients undergoing percutaneous coronary intervention (PCI) are inconclusive.

Purpose

We aimed to perform a meta-analysis to investigate the clinical outcomes of BP-DES compared with second-generation DP-DES in patients who have undergone PCI.

Methods

We searched PubMed, MEDLINE, EMBASE, and Cochrane databases through January 2019 for randomized controlled trials comparing BP-DES with second-generation DP-DES in patients treated with PCI. All-cause death, cardiac death, myocardial infarction (MI), target vessel revascularization (TVR), target lesion revascularization (TLR), definite/probable stent thrombosis (ST) were compared between the groups. Additionally, a landmark analysis with the landmark set at 1 year and a subgroup analysis according to stent characteristics were performed.

Results

Data from 23 trials including 28802 randomized patients were analyzed. At a median follow up of 3.1 years, no significant differences were found in terms of all-cause death (odds ratio [OR] 1.05, 95% confidence interval [CI] 0.95–1.16), cardiac death (OR 1.01, 95% CI 0.87–1.17), MI (OR 0.92, 95% CI 0.82–1.03), TVR (OR 0.97, 95% CI 0.86–1.11), TLR (OR 0.97, 95% CI 0.85–1.11), and definite/probable ST (OR 0.86, 95% CI 0.70–1.07) between the groups. Landmark analysis showed that there were similar risks in all-cause death (OR 1.04, 95% CI 0.93–1.17), cardiac death (OR 1.11, 95% CI 0.92–1.36), MI (OR 0.94, 95% CI 0.79–1.13), TVR (OR 0.95, 95% CI 0.73–1.23), TLR (OR 1.00, 95% CI 0.80–1.24), and definite/probable ST (OR 0.92, 95% CI 0.67–1.28) between the groups. The similar tendency of any study endpoints between the groups was consistent in the subgroup, including stent platform (stainless steel vs. alloy), the drug coating distribution (abluminal vs. circumferential), the polymer degradation period (<6 months vs. >6 months), or the drug release duration (<6 months vs. >6 months) of BP-DES, or the DAPT duration (≥6 months vs. ≥12 months). However, the uses of BP-DES with sirolimus-eluting (OR 0.84, 95% CI 0.72–0.98) or ultrathin strut (defined as <70μm; OR 0.81, 95% CI 0.68–0.97) were predictive for lower risk of MI.

Clinical outcomes

Conclusions

In our updated meta-analysis, BP-DES implantation was associated with comparable clinical outcomes compared with second-generation DP-DES implantation. However, PCI with ultrathin biodegradable polymer sirolimus-eluting stent could reduce the risk of MI.

P2799Long-term outcomes after percutaneous coronary intervention with biodegradable polymer drug-eluting stent versus second-generation durable polymer drug-eluting stent: evidence from a meta-analysis

Background

The true benefit of biodegradable polymer drug-eluting stent (BP-DES) over second-generation durable polymer drug-eluting stent (DP-DES) expected to be represented during late period of follow-up after percutaneous coronary intervention (PCI), but prior meta-analysis only evaluated short-term outcomes.

Purpose

We aimed to compare the long-term clinical outcomes after PCI with BP-DES versus second-generation DP-DES by a meta-analysis of randomized controlled trials.

Methods

Randomized controlled trials comparing BP-DES with second-generation DP-DES implantations were searched through PubMed, MEDLINE, EMBASE, and Cochrane databases. All-cause death, cardiac death, myocardial infarction (MI), target vessel revascularization (TVR), target lesion revascularization (TLR), and definite/probable stent thrombosis (ST) were compared between the groups. In addition, a landmark analysis with the landmark set at 1-year and a subgroup analysis based on stent characteristics were performed.

Results

Fifteen trials that included a total of 21311 randomized patients with at least 2 years follow-up were analyzed. At a median follow-up of 4.2 years, no significant differences in the risks of all-cause death (odds ratio [OR] 1.03, 95% confidence interval [CI] 0.94–1.14), cardiac death (OR 1.03, 95% CI 0.88–1.20), MI (OR 0.90, 95% CI 0.79–1.01), TVR (OR 0.96, 95% CI 0.82–1.12), TLR (OR 0.97, 95% CI 0.85–1.11), and definite/probable ST (OR 0.84, 95% CI 0.67–1.05) were found between the groups. In the 1-year landmark analysis, the rates of all-cause death (OR 1.04, 95% CI 0.93–1.17), cardiac death (OR 1.11, 95% CI 0.92–1.36), MI (OR 0.94, 95% CI 0.79–1.13), TVR (OR 0.95, 95% CI 0.73–1.23), TLR (OR 1.00, 95% CI 0.80–1.24), and definite/probable ST (OR 0.94, 95% CI 0.67–1.31) were similar between the groups. There were comparable rates of any study endpoints between the groups regardless of stent platform (stainless steel vs. alloy), the polymer degradation period (<6 months vs. >6 months) or the drug release duration (<6 months vs. >6 months) of BP-DES, or the DAPT duration (≥6 months vs. ≥12 months). However, the use of BP-DES with sirolimus eluting (OR 0.82, 95% CI 0.70–0.97), circumferential drug distribution (OR 0.79, 95% CI 0.65–0.96), thin strut (defined as <100μm; OR 0.83, 95% CI 0.70–0.97), or ultrathin strut (defined as <70μm; OR 0.78, 95% CI 0.64–0.94) were associated with lower rates of MI than did second-generation DP-DES. Moreover, BP-DES with circumferential drug distribution (OR 0.82, 95% CI 0.69–0.98) was predictive for reduced rates of TVR.

Clinical outcomes

Conclusions

In this meta-analysis, long-term clinical outcomes were equivalent between BP-DES and second-generation DP-DES implantations. However, among BP-DESs, the improved risks of MI in those with sirolimus eluting, circumferential drug distribution, thin strut, or ultrathin strut and decreased rates of TVR in those with circumferential drug distribution were noted.

Non-tuberculous Mycobacterium infection after transfer of autologous fat to the face: a rare case

Autologous fat has long been used as a filler in the face, and has recently gained popularity in plastic surgery with a wound infection rate of 1% - 5%. The incidence of mycobacterial infections has increased over recent decades, which is attributed in part to the increased popularity of these procedures.² Infections by non-tuberculosis mycobacteria often cause chronic inflammation and progressive infection that may eventually manifest themselves as severe scars, fistulas, and hollows, and irregular facial contours. However, few cases of mycobacterial infection have been reported to have been caused by plastic surgery. We present a rare case of non-tuberculosis mycobacterial infection after transfer of autologous fat to the face.

Identification of transfusion-transmitted hepatitis A through postdonation information in Korea: results of an HAV lookback (2007-2012)

BACKGROUND AND OBJECTIVES

Despite safety measures to minimize the risk of transfusion-transmitted infections, a residual risk remains. To trace and review some such cases, we ask donors to notify the blood centre if they are diagnosed with an infection after they donate blood.

MATERIALS AND METHODS

We analysed all data on postdonation cases of hepatitis A reported between 2007 and 2012. Archived specimens from these donors were tested for hepatitis A virus (HAV) using anti-HAV IgM/IgG and HAV-PCR as markers. If any of the test results were positive, we reviewed the medical records of the recipients and, if necessary, tested them for hepatitis A.

RESULTS

Fifteen blood donors notified the blood centres of having been diagnosed with hepatitis A after donation. All archived samples except for one were HAV-PCR-positive and anti-HAV IgM/IgG-negative. Of the donated components, four RBCs and 14 FFPs had not been transfused to patients and were recalled. Among 26 recipients of the implicated components, fourteen were still alive when they were notified. Two patients showed clinical symptoms of hepatitis A and had positive results with anti-HAV IgM.

CONCLUSION

Transfusion-transmitted hepatitis A is rare but exists. To reduce the risk, donors should be told to notify the blood centre if they are diagnosed with blood-borne diseases after they donate blood. Physicians should consider the possibility of transfusion-transmitted hepatitis A if a transfused patient has hepatitis A but no history of travel or route of faecal-oral infection.

Radix Polygalae Extract Attenuates PTSD-like Symptoms in a Mouse Model of Single Prolonged Stress and Conditioned Fear Possibly by Reversing BAG1

Radix Polygalae (RP) has been used to relieve psychological stress in traditional oriental medicine. Recently, cell protective, antiamnestic and antidepressant-like effects were disclosed but the possible application of RP to post-traumatic stress disorder, in which exaggerated fear memory persists, has not yet been explored. For this purpose, the effects of RP on fear behavior was examined in a mouse model of single prolonged stress and conditioned fear (SPS-CF), previously shown to mimic key symptoms of post-traumatic stress disorder. Male mice received daily oral dose of RP extract or vehicle during the SPS-CF procedure. Then fear-related memory (cohort 1, n=25), non-fear-related memory (cohort 2, n=38) and concentration-dependent effects of RP on fear memory (cohort 3, n=41) were measured in 3 separate cohort of animals. Also working memory and anxiety-like behaviors were measured in cohort 1. RP-treated SPS-CF mice exhibited attenuated contextual but not cued freezing and no impairments in the working memory and spatial reference memory performances relative to vehicle-treated SPS-CF controls. RP-treated SPS-CF and naive mice also demonstrated no difference in anxiety-like behavior levels relative to vehicle-treated SPS-CF and naive controls, respectively. In the hippocampus of SPS-CF mice, expression of BAG1, which regulates the activity of GR, was decreased, whereas RP increased expression of BAG1 in naïve and SPS-CF mice. These results suggest that RP exerts some symptomatic relief in a mouse with exaggerated fear response. RP and its molecular components may thus constitute valuable research targets in the development of novel therapeutics for stress-related psychological disorders.

Underestimated caregiver burden by cancer patients and its association with quality of life, depression and anxiety among caregivers

This study examined how patients with cancer estimate caregiver burden (CB) and the association between their underestimation of CB and their caregivers' self-ratings of their quality of life (CQOLC-K; Korean version of the Caregiver Quality of Life Index-Cancer), depression and anxiety (Korean version of the Hospital Anxiety and Depression Scale). Participants consisted of 990 patient-caregiver dyads recruited from a nationwide cross-sectional survey conducted in South Korea. Medical baseline data were retrieved from the hospital information systems of the participating centres. The patients with cancer who underestimated CB ranged from 18.62% (for physical CB) to 23.33% (for social CB). They had less advanced cancer, a lower income, were the caregiver's spouse, reported higher levels of family avoidance of communication about cancer, and had female caregivers. The patients' underestimation of CB was significantly related to lower CQoL and higher levels of caregiver depression and anxiety. The current study provides empirical evidence for the link between the underestimation of CB by patients with cancer and compromised caregiving experiences of cancer caregivers. Open family communication about cancer was discussed as one of several practical strategies for decreasing patients' underestimation of CB.

Hematological adverse effects and pharmacokinetics of ribavirin in pigs following intramuscular administration

Ribavirin (RBV) is a synthetic guanosine analog that is used as a drug against various viral diseases in humans. The in vitro antiviral effects of ribavirin against porcine viruses were demonstrated in several studies. The purposes of this study were to evaluate the adverse effects and pharmacokinetics of ribavirin following its intramuscular (IM) injection in pigs. Ribavirin was formulated as a double-oil emulsion (RBV-DOE) and gel (RBV-Gel), which were injected into the pigs as single-dose IM injections. After injection of RBV, all of the pigs were monitored. The collected serum and whole blood samples were analyzed by liquid chromatography-tandem mass spectrometry and complete blood count analysis, respectively. All of the ribavirin-treated pigs showed significant decreases in body weight compared to the control groups. Severe clinical signs including dyspnea, anorexia, weakness, and depression were present in ribavirin-treated pigs until 5 days postinjection (dpi). The ribavirin-treated groups showed significant decrease in the number of red blood cells and hemoglobin concentration until 8 dpi. The mean half-life of the RBV-DOE and RBV-Gel was 27.949 ± 2.783 h and 37.374 ± 3.502 h, respectively. The mean peak serum concentration (C_max ) and area under the serum concentration-time curve from time zero to infinity (AUC_inf ) of RBV-DOE were 8340.000 ± 2562.577 ng/mL and 16 0095.430 ± 61 253.400 h·ng/mL, respectively. The C_max and AUC_inf of RBV-Gel were 15 300.000 ± 3764.306 ng/mL and 207526.260 ± 63656.390 h·ng/mL, respectively. The results of this study provided the index of side effect and pharmacokinetics of ribavirin in pigs, which should be considered before clinical application.

Effects of Per-diem payment on the duration of hospitalization and medical expenses according to the palliative care demonstration project in Korea

OBJECTIVES

The aim of this study was to examine the impacts of a government-directed palliative care demonstration (PCD) project, Per-diem Payment System (PDPS), on length of stay (LOS), hospital costs, resource usage and healthcare quality during the searched period from January in 2009 to December in 2010.

STUDY DESIGN

A retrospective claim data review.

METHODS

Individuals who had been eligible for the palliative care payment policy, PDPS, during 2 years (from 2009 to 2010) were assigned to the case group including seven hospitals (n = 3117). Those (seven hospitals) who were not come eligible for the palliative care payment policy were assigned to the control group (n = 2347) with fee for service. The data used in this study were electronically submitted requests of payment to the Health Insurance Review Agency during the period January 2009 to December 2010.

RESULTS

After the PCD project, the length of stay for palliative patients with cancer diseases decreased by 2.56% (β = -0.026; p-value = 0.0001) among patients hospitalized in a PCD project compared with patients hospitalized in seven hospitals that was not designed as a PCD project. Compared with costs before the PCD project, costs decreased by 0.76% (β = 0.013; p-value = 0.0001).

CONCLUSIONS

We provided evidence regarding the change in the societal burden due to palliative care. Although there was a reduction of direct medical costs reported in limited number of hospitals, in the long term, we can anticipate an expanding impact on medical costs in all palliative hospitals. Copyright © 2016 John Wiley & Sons, Ltd.

Role of protein kinase C-η in cigarette smoke extract-induced apoptosis in MRC-5-cells

Cigarette smoke (CS) is a major risk factor for emphysema, which causes cell death in structural cells of the lung by mechanisms that are still not completely understood. We demonstrated previously that CS extract (CSE) induces caspase activation in MRC-5 human lung fibroblasts, activated protein kinase C-η (PKC-η), and translocated PKC-η from the cytosol to the membrane. The objective of this study was to investigate the involvement of PKC-η activation in a CSE-induced extrinsic apoptotic pathway. We determined that CSE increases expression of caspase 3 and 8 cleavage in MRC-5 cells and overexpression of PKC-η significantly increased expression of caspase 3 and 8 cleavage compared with control LacZ-infected cells. In contrast, dominant negative (dn) PKC-η inhibited apoptosis in MRC-5 cells exposed to CSE and decreased expression of caspase 3 and 8 compared with control cells. Exposure to 10% CSE for >8 h significantly increased lactate dehydrogenase release in PKC-η-infected cells compared with LacZ-infected cells. Additionally, PKC-η-infected cells had an increased number of Hoechst 33342 stained nuclei compared with LacZ-infected cells, while dn PKC-η-infected cells exhibited fewer morphological changes than LacZ-infected cells under phase-contrast microscopy. In conclusion, PKC-η activation plays a pro-apoptotic role in CSE-induced extrinsic apoptotic pathway in MRC-5 cells. These results suggest that modulation of PKC-η may be a useful tool for regulating the extrinsic apoptosis of MRC-5 cells by CSE and may have therapeutic potential in the treatment of CS-induced lung injury.

A general strategy for generating intact, full-length IgG antibodies that penetrate into the cytosol of living cells

Full-length IgG antibodies cannot cross cell membranes of living cells; this limits their use for direct targeting of cytosolic proteins. Here, we describe a general strategy for the generation of intact, full-length IgG antibodies, herein called cytotransmabs, which internalize into living cells and localize in the cytosol. We first generated a humanized light chain variable domain (VL) that could penetrate into the cytosol of living cells and was engineered for association with various subtypes of human heavy chain variable domains (VHs). When light chains with humanized VL were co-expressed with 3 heavy chains (HCs), including 2 HCs of the clinically approved adalimumab (Humira®) and bevacizumab (Avastin®), all 3 purified IgG antibodies were internalized into the cytoplasm of living cells. Cytotransmabs primarily internalized into living cells by the clathrin-mediated endocytic pathway through interactions with heparin sulfate proteoglycan that was expressed on the cell surface. The cytotransmabs escaped into the cytosol from early endosomes without being further transported into other cellular compartments, like the lysosomes, endoplasmic reticulum, Golgi apparatus, and nucleus. Furthermore, we generated a cytotransmab that co-localized with the targeted cytosolic protein when it was incubated with living cells, demonstrating that the cytotransmab can directly target cytosolic proteins. Internalized cytotransmabs did not show any noticeable cytotoxicity and remained in the cytosol for more than 6 h before being degraded by proteosomes. These results suggest that cytotransmabs, which efficiently enter living cells and reach the cytosolic space, will find widespread uses as research, diagnostic, and therapeutic agents.

Multicentre study of robotic intersphincteric resection for low rectal cancer

BACKGROUND

There is a lack of information regarding the oncological safety of robotic intersphincteric resection (ISR) with coloanal anastomosis. The objective of this study was to compare the long-term feasibility of robotic compared with laparoscopic ISR.

METHODS

Between January 2008 and May 2011, consecutive patients who underwent robotic or laparoscopic ISR with coloanal anastomosis from seven institutions were included. Propensity score analyses were performed to compare outcomes for groups in a 1 : 1 case-matched cohort. The primary endpoint was 3-year disease-free survival.

RESULTS

A total of 334 patients underwent ISR with coloanal anastomosis, of whom 212 matched patients (106 in each group) formed the cohort for analysis. The overall rate of conversion to open surgery was 0.9 per cent in the robotic ISR group and 1.9 per cent in the laparoscopic ISR group. Nine patients (8.5 per cent) in the laparoscopic group and three (2.8 per cent) in the robotic ISR group still had a stoma at last follow-up (P = 0.075). Total mean hospital costs were significantly higher for robotic ISR (€ 12,757 versus € 9223 for laparoscopic ISR; P = 0.037). Overall 3-year local recurrence rates were similar in the two groups (6.7 per cent for robotic and 5.7 per cent for laparoscopic resection; P = 0.935). The combined 3-year disease-free survival rates were 89.6 (95 per cent c.i. 84.1 to 95.9) and 90.5 (85.4 to 96.6) per cent respectively (P = 0.298).

CONCLUSION

Robotic ISR with coloanal anastomosis for rectal cancer has reasonable oncological outcomes, but is currently too expensive with no short-term advantages.

Clinical significance of serum bilirubin and gamma-glutamyltransferase levels on coronary atherosclerosis assessed by multidetector computed tomography

BACKGROUND AND AIMS

Low bilirubin and high gamma-glutamyltransferase (GGT), which are endogenous markers of oxidative stress, confer a higher risk of cardiovascular disease (CVD). We investigated associations between serum concentrations of bilirubin, GGT and coronary atherosclerosis.

METHODS AND RESULTS

A cross-sectional analysis was performed on 1520 subjects who underwent multidetector computed tomography scans. Coronary atherosclerosis was assessed by coronary artery calcium score (CACS) and obstructive coronary artery disease (OCAD), was defined as the presence of coronary artery stenosis of ≥50%. Total bilirubin (TB) level was negatively correlated with CACS and coronary stenosis whereas GGT level was positively correlated with CACS in men. However, there was no correlation between TB, GGT levels and either CACS or coronary artery stenosis in women. In a multivariate-adjusted model, TB level was inversely associated with a CACS > 100 [odds ratio (OR) per log standard deviation (SD), 0.67; 95% confidence interval (CI), 0.52-0.87], and OCAD (OR per log SD, 0.77; 95% CI, 0.62-0.95) in men. By contrast, GGT level was positively associated with a CACS > 100 (OR per log SD, 1.35; 95% CI, 1.05-1.73) but not with OCAD. Adding TB and GGT to the conventional risk factors increased predictive accuracy for CACS > 100 (net reclassification improvement index [NRI] = 13.1%, P = 0.026; integrated discrimination index [IDI] = 0.024, P = 0.001) and for OCAD (NRI = 12.6%, P = 0.026; IDI = 0.010, P = 0.013).

CONCLUSIONS

Low TB and high GGT levels were concomitantly associated with coronary atherosclerosis in Korean men. Future studies are needed to elucidate the causal associations of TB and GGT with CVD.

Blood donors on teratogenic drugs and donor deferral periods in a clinical situation

Deferral of blood donors taking teratogenic drugs is critical. From March 2008 to January 2009, we analysed stored blood specimens from donors who had taken teratogenic drugs and whose blood was transfused to women of childbearing age to determine the plasma concentration at the time of donation using high-performance liquid chromatography. In total, 167 specimens were examined. The numbers of specimens exceeding the quantification limit were 7, 39, 4, 2 and 1 for finasteride, isotretinoin, acitretin, etretinate and dutasteride, respectively. Finasteride was beyond the recommended drug deferral period in one specimen. These results may help create practical deferral policies.

Glass-type wireless PPG measuring system

This paper is about a glass-type wireless bio-signal transmitter that can monitor the user's health state in daily life. The device implemented in this study consists of the transmission part and the receiving part. The transmission part includes a photoplethysmography(PPG) sensor for detecting pulse wave signals, accelerometer for detecting kinetic signals, and a wireless controller for transmitting acquired bio-information. The receiving part is designed to check and process transmitted data through interoperation with a PC. In the experiments, we collected data during a sitting posture and repeated sit-to-stand motion in laboratory environment, and analyzed the data. As to accuracy, the correlation between the peak-to-peak intervals in the signals of the Biopac equipment and the developed device measured in a sitting posture was 97.5%, and that measured in sit-to-stand motion was 87%. In addition, when bio-signals were transmitted through wireless communication, the transmission was successful 100% without any error. When pulse wave signals and kinetic signals were obtained and compared, the results proved the accuracy and daily applicability of the developed device, and the glass-type wireless bio-signal transmission system is expected to be applicable to unobtrusive health monitoring for the user.

Portable digital esophageal stethoscope system

Heart sound occurs when the heart contracts and expands. It provides information on myocardial contractility and blood vessels, which is not obtainable from ECG. For this reason, stethoscopy of heart sound in anesthesiology is a very crucial means for acquiring cardiac information and preventing intraoperative medical accidents, and it requires a system for precise objective measurement and analysis of heart sound and murmur. Thus, this study purposed to develop portable digital esophageal stethoscope (PDES) that can objectify and quantify heart sound and murmur. In this study, we designed PDES for precise measurement and analysis of heart sound and murmur data. Heart sound information obtained by inserting the sensor of the PDES into the patient's esophagus can be transmitted to a terminal or a PC and displayed on the screen The amplitude and waveform of heart sound are displayed using self-developed software Heart Sound 1.0. The results of experiment with the developed PDES showed that data on the amplitude and waveform of heart sound and murmur were produced stably in real-time. In addition, when heart sound was heard using a headphone, the sound was clear without external murmur. The PDES developed in this study, which complements the disadvantages of traditional esophageal stethoscope while preserving its advantages, could not only examine heart sound and murmur using an esophageal catheter but also display the amplitude and waveform of heart sound and murmur and measure the patient's body temperature. Accordingly, the developed PDES is expected to be useful in the continuous stethoscopy of heart sound during operation and to contribute to research on heart sound by providing heart sound data.

Deguelin inhibits retinal neovascularization by down-regulation of HIF-1alpha in oxygen-induced retinopathy

Retinal neovascularization is the most common cause of blindness; Retinopathy of pre-maturity (ROP) for children and diabetic retinopathy for young age group. ROP still remains as the most serious cause of vision loss in children. We provided that deguelin significantly reduces retinal neovascularization in a mouse model of ROP. Deguelin never affected the transcriptional activity of hypoxia inducible factor (HIF)-1, however, reduced HIF-1 expression, which led to the decrease of vascular endothelial growth factor expression. Deguelin effectively suppressed endothelial cell proliferation without cytotoxic effect under therapeutic concentration range. In addition, deguelin demonstrated no reduction or retardation in normal retinal development and no retinal toxicity. These data suggest deguelin is a potent inhibitor of retinal neovascularization and may be applied in the treatment of other vasoproliferative retinopathies.

The effects of a home-based intervention for young children with intellectual disabilities in Vietnam

BACKGROUND

This study was conducted to examine the impact of a 1-year intervention for children with intellectual disabilities (ID) in Vietnam.

METHOD

Subjects were 30 preschool-aged children with ID (ages 3 to 6 years). Sixteen were assigned to an intervention group and 14 to a control group. Based on the Portage Curriculum (CESA 5 2003), the intervention trained parents to work with their children through modelling and coaching by teachers during weekly home visits.

RESULTS

Comparison of pre-, mid- and post-intervention assessments of the children based on the Vineland Adaptive Behavior Scales (Sparrow et al. 1984a) indicated that the intervention was promising: children in the intervention group improved significantly in most domains of adaptive behaviours, and also performed significantly better than the control group in the areas of personal care and motor skills.

CONCLUSIONS

The results from the Vietnam programme are discussed in terms of its implications and strategies for developing programmes for children with disabilities in developing countries.

Evaluation of Subchronic Inhalation Toxicity of Dimethyl Disulfide in Rats

This study was carried out to investigate the potential subchronic inhalation toxicity of dimethyl disulfide (DMDS) via whole-body exposure in F344 rats. Groups of 10 rats of each sex were exposed to DMDS vapor by whole-body exposure at concentrations of 0, 5, 25, or 125 ppm for 6 h/day, 5 days/wk for 13 wk. All the rats were sacrificed at the end of treatment period. During the test period, clinical signs, mortality, body weights, food consumption, ophthalmoscopy, urinalysis, hematology, serum biochemistry, gross findings, organ weights, and histopathology were examined. At 25 ppm, a decrease in the body weight gain, food intake, aspartate aminotransferase (AST), alanine aminotransferase (ALT), and blood urea nitrogen (BUN) was observed in the males, but not in the females. However, at 125 ppm, a decrease in the body weight gain, food intake, and thymus weight and an increase in the weights of adrenal glands were observed in both genders. Serum biochemical investigations revealed a decrease in the AST, ALT, BUN, creatine phosphokinase (CPK), and triglyceride levels and an increase in the glucose level. In contrast, no treatment-related effects were observed in the 5 ppm group. The toxic potency of DMDS was slightly higher in males than that in females. In these experimental conditions, the target organ was not determined in rats. The no-observed-adverse-effect concentration (NOAEC) was found to be 5 ppm, 6 h/day for male rats and 25 ppm, 6 h/day for female rats.

Relationship between gamma-glutamyltransferase and metabolic syndrome in a Korean population

AIMS

To investigate associations between gamma-glutamyltransferase (GGT) and components of metabolic syndrome (MS), insulin resistance and inflammatory markers in the Korean population.

METHODS

The 3508 subjects enrolled in this survey participated in the Korean Rural Genomic Cohort (KRGC) study. Written consent was obtained from the local ethical committee. Of these participants, 1437 were men (mean age 56.9 +/- 7.9 years) and 2071 were women (mean age 55.8 +/- 8.1 years). We measured GGT levels and various biochemical markers. To examine insulin resistance status, we used the homeostasis assessment method for insulin resistance (HOMA-IR). For inflammatory marker, we used C-reactive protein (CRP) levels.

RESULTS

Serum GGT levels were significantly higher in the MS group compared to the healthy patient group [23 (5-1403) vs. 19 (5-1920) IU/l; P = 0.01]. The prevalence of MS and adjusted relative risk were both significantly increased from the lowest to highest GGT quartiles; these results persisted after adjustments for multiple confounders. Positive correlations were established between GGT and HOMA-IR or CRP.

CONCLUSION

These results suggest that GGT levels may be a surrogate marker of insulin resistance, inflammation and MS.

Stoichiometry of coagulation revisited

The roles of particles and natural organic matter (NOM) in determining coagulant (alum) doses in potable water treatment were investigated at two pH conditions (6 and 7). The concentrations of NOM and colloidal silica particles in raw water were systematically varied separately and in combination, and the impacts of these two classes of contaminants on the minimum effective alum doses were investigated using observations of turbidity and dissolved organic carbon (DOC) in laboratory jar tests. At both pHs, coagulant requirements for the removal of these contaminants by sedimentation and filtration were dominated by the DOC concentration in the raw water. The presence of low NOM concentrations (0.75-1.5 mg of C/L) decreased the minimum effective alum dose dramatically for waters low in silica particles, possibly by promoting the precipitation of aluminum hydroxide and/or Al-NOM solids, whose removal would otherwise be limited by low collision opportunities. Strong stoichiometric relationships were observed between DOC and coagulant demand at both pHs regardless of silica particle concentration. Silica contributed to coagulant demand only at very high particle concentrations.

The impact of the absolute number and ratio of positive lymph nodes on survival of endometrioid uterine cancer patients

The aim of the study was to determine the impact of the absolute number and ratio of positive lymph nodes on the survival in node-positive endometrioid uterine cancer. Data were obtained from the National Cancer Institute Registry from 1988 to 2001. Analyses were performed using Kaplan–Meier and Cox proportional hazard methods. A total of 1222 women were diagnosed with stage IIIC-IV node-positive endometrioid corpus cancer. The 5-year disease-specific survival of women with 1, 2–5, and >5 positive nodes were 68.1, 55.1, and 46.1%, respectively (P<0.001). Increasing lymph node ratio, expressed as a percentage of positive nodes to total nodes identified (⩽10, >10–⩽50, and >50%), was associated with a decrease in survival from 77.3 to 60.7 to 40.9%, respectively (P<0.001). The absolute number of positive nodes and the lymph node ratio remained significant after adjusting for stage (IIIC vs IV) and the extent of lymphadenectomy (⩽20 vs >20 nodes). On multivariate analysis, the absolute number of positive nodes and lymph node ratio were significant independent prognostic factors for survival. Increasing absolute number of positive nodes and lymph node ratio are associated with a poorer survival in women with node-positive uterine cancers. The stratification of node-positive uterine cancer for prognostic and treatment purposes warrants further investigation.

The potential therapeutic role of lymph node resection in epithelial ovarian cancer: a study of 13918 patients

The aim of the study is to determine the role of lymphadenectomy in advanced epithelial ovarian cancer. The data were obtained from the Surveillance, Epidemiology and End Results (SEER) program reported between 1988 and 2001. Kaplan–Meier estimates and Cox proportional hazards regression models were used for analysis. Of 13 918 women with stage III–IV epithelial ovarian cancer (median age: 64 years), 87.9% were Caucasian, 5.6% African Americans, and 4.4% Asians. A total of 4260 (30.6%) underwent lymph node dissections with a median number of six nodes reported. For all patients, a more extensive lymph node dissection (0, 1, 2–5, 6–10, 11–20, and >20 nodes) was associated with an improved 5-year disease-specific survival of 26.1, 35.2, 42.6, 48.4, 47.5, and 47.8%, respectively (P<0.001). Of the stage IIIC patients with nodal metastases, the extent of nodal resection (1, 2–5, 6–10, 11–20, and >20 nodes) was associated with improved survivals of 36.9, 45.0, 47.8, 48.7, and 51.1%, respectively (P=0.023). On multivariate analysis, the extent of lymph node dissection and number of positive nodes were significant independent prognosticators after adjusting for age, year at diagnosis, stage, and grade of disease. The extent of lymphadenectomy is associated with an improved disease-specific survival of women with advanced epithelial ovarian cancer.

Evaluation of developmental toxicity of amitraz in Sprague-Dawley rats

This study investigated the potential adverse effects of amitraz on the initiation and maintenance of pregnancy in Sprague-Dawley rats as well as its effects on embryo-fetal development after maternal exposure during the entire pregnancy period. Amitraz was administered to pregnant rats by gavage from days 1 to 19 of gestation at dose levels of 0, 3, 10, and 30 mg/kg/day. All dams underwent a caesarean section on day 20 of gestation and their fetuses were examined for any external, visceral, and skeletal abnormalities. At 30 mg/kg, maternal toxicity manifested as an increase in the incidence of abnormal clinical signs and a lower body weight gain and food intake. Developmental toxicity included an increase in the fetal death rate, a decrease in the litter size, and a reduction in the fetal body weight. In addition, there was an increase in the incidence of fetal external, visceral, and skeletal abnormalities. At 10 mg/kg, maternal toxicity observed included a decrease in the body weight gain and a decrease in food intake. In addition, minimal developmental toxicity, including a decrease in the fetal body weight, an increase in the visceral and skeletal aberrations, and a delay in fetal ossification. There were no signs of either maternal toxicity or developmental toxicity at 3 mg/kg. These results show that amitraz administered during the entire pregnancy period in rats is embryotoxic and teratogenic at the maternally toxic dose (i.e., 30 mg/kg/day) and is minimally embryotoxic at a minimally maternally toxic dose (i.e., 10 mg/kg/day). Under these experimental conditions, the no-observed-adverse-effect level of amitraz for both dams and embryo-fetal development is estimated to be 3 mg/kg/day.

Ovarian cancer in younger vs older women: a population-based analysis

To compare the clinico-pathologic prognostic factors and survival of younger vs older women diagnosed with epithelial ovarian cancer. Demographic, clinico-pathologic, treatment, and surgery information were obtained from patients with ovarian cancer from the Surveillance, Epidemiology, and End Results Program from 1988 to 2001 and analysed using Kaplan–Meier estimates. Of 28 165 patients, 400 were <30 years (very young), 11 601 were 30–60 (young), and 16 164 were >60 (older) years of age. Of the very young, young, and older patients, 261 (65.3%), 4664 (40.2%), and 3643 (22.5%) had stage I–II disease, respectively (P<0.001). Across all stages, very young women had a significant survival advantage over the young and older groups with 5-year disease-specific survival estimates at 78.8% vs 58.8 and 35.3%, respectively (P<0.001). This survival difference between the age groups persists even after adjusting for race, stage, grade, and surgical treatment. Reproductive age (16–40 years) women with stage I–II epithelial ovarian cancer who received uterine-sparing procedures had similar survivals compared to those who underwent standard surgery (93.3% vs 91.5%, P=0.26). Younger women with epithelial ovarian cancer have a survival advantage compared to older patients.

Pretreatment chemistry for dual media filtration: model simulations and experimental studies

Laboratory dual media filtration experiments were conducted (a) in direct filtration mode using model raw water moderate in turbidity and low in DOC, and (b) in conventional filtration mode treating water moderate in turbidity and high in DOC. Model simulations of filter performance for the removal of particles provided hypotheses for the experimental studies of dual media filtration. An increase in alum dose in direct filtration mode, while improving filter performance, also showed some disadvantages, including rapid development of head loss. Suboptimal dose in direct filtration significantly impaired the filter performance. In conventional mode, the effect of alum dose on the filter performance, while obvious, was not as dramatic as in direct filtration. Ripening indicated by particle counts occurred earlier than by turbidity and breakthrough of particle counts started earlier than breakthrough of turbidity, suggesting that turbidity can be used as a more conservative monitor of filter performance during the ripening period to minimise the risk of passage of small particles, while particle counts can be considered a more sensitive indicator of deteriorating filter performance during the breakthrough period. The lower sand layer served as a multiple barrier for particle when the performance of the anthracite layer was not effective.

Purification and Characterization of Intracellular Proteinase from Lactobacillus casei ssp. casei LLG

The intracellular proteinase of Lactobacillus casei ssp. casei LLG was isolated in the cytoplasmic fraction with 0.05 M Tris-HCl buffer (pH 7.5). The enzyme was purified by the fast protein liquid chromatography system equipped with ion-exchange and gel filtration chromatographies. This proteinase comprised a single monomeric form and had a molecular weight of about 55 kDa and an isoelectric point near pH 4.9. The optimum pH and temperature for the enzyme activity were determined to be pH 6.5 and 37 degrees C, respectively. The enzyme was inactivated by metal-chelating compounds (EDTA, 1,10-phenanthroline) and less affected by serine proteinase inhibitors (diisopropylfluorophosphate, phenylmethylsulfonyl fluoride). Proteinase activity was increased by Ca++, Mn++, and Co++, and inhibited by Cu++, Mg++, and Zn++. The activity of this enzyme to hydrolyze casein appeared to be more active on beta-casein than alphas1-casein and kappa-casein as monitored by polyacrylamide gel electrophoresis.

Antitumor effect of intratumoral administration of dendritic cell combination with vincristine chemotherapy in a murine fibrosarcoma model

A new antitumor therapeutic strategy utilizing the combined effect of chemotherapy and DC (dendritic cell)-based immunotherapy was designed, and the effect of intratumoral injections of unpulsed, immature DCs was evaluated after in vivo pretreatment of vincristine on tumor growth in a murine fibrosarcoma tumor model. Vincristine exerted a much more potent apoptosis/necrosis-inducing effect on MCA-102 tumor cells than on DCs both in vitro and in vivo. Moreover, CD11c, CD40, CD80 and CD86 molecules on DCs were not downregulated after treatment with vincristine either in vitro or in vivo. The growth of tumor significantly regressed in the group which received the combined vincristine chemotherapy with intratumoral administration of DCs in contrast to the untreated group, the group treated with DCs alone, and the group treated with vincristine alone. In particular, an upregulated expression of CD40, CD80 and CD86 molecules on DCs was found in the combination treatment group. Furthermore, the number of CD4+ and CD8+ T cells and the staining intensity of their CD4 and CD8 surface molecules also increased after the combination treatment. Therefore, our results indicate the feasibility of this combination therapy with vincristine chemotherapy and DC-based immunotherapy as an efficient antitumor strategy for the treatment of fibrosarcoma.

Application of cDNA microarray technique to detection of gene expression in host cells infected with viruses

cDNA microarray technique was used to monitor changes in mRNA levels in cells after Hantaan virus (HTNV) infection. The values of the ratio of medians for HTNV and Japanese encephalitis virus (JEV) at the early stage of infection were compared and found similar, suggesting that the same or similar genes are associated with the early events of infection with either virus. The reproducibility of values of the "ratio of medians" for HTNV was examined. We found that applying cluster analysis to the gene expression data groups efficiently together genes with the same function. Therefore, in analyzing the effects of viral infection on host cells by the cDNA microarray technique, clustering data appear to be necessary for gaining biological meaning from a dump of gene expression profiles obtained from virus-infected cells.

Immortalization of human embryonic fibroblasts by overexpression of c-myc and simian virus 40 large T antigen

SV40 large T antigen, a viral oncoprotein, is known to immortalize human diploid fibroblast by soaking up cellular RB and p53, but its frequency is extremely low. Additional genetic alteration is necessary for single-step immortalization. We attempted to find out what this alteration is by overexpressing cellular signal mediator genes; c-myc and cyclin D frequently amplified in many cancer cells. Overexpression of cyclin D did not affect the immortalization, but, overexpression of c-myc along with T antigen could immortalize normal human diploid fibroblast. Several cellular markers tested during immortalization process showed that p21, a cyclin-dependent kinase inhibitor and a marker of cellular senescence, disappeared in the life span-extended cells by T antigen and in the immortalized cells by c-myc. p21 was, however, elevated in the senescent cells and in the cells of crisis. Interestingly, p16 was upregulated whenever T antigen is overexpressed. Telomerase activity was also activated only in the immortalized cells. These results suggest that overexpression of c-myc contributes to immortalization of human diploid fibroblast by activating telomerase activity and suppressing p21 activity.

Analysis of the in vivo dendritic cell response to the bacterial superantigen staphylococcal enterotoxin B in the mouse spleen

To investigate the in vivo effects of Staphylococcal enterotoxin B (SEB) on dendritic cells (DCs) in the spleen, a single dose of SEB (50 microg/kg) was administered to BALB/c mice by intraperitoneal injection. Afterwards, the mice were sacrificed at 2, 6 and 24 hr, 2, 4, 7 and 15 days, and the spleens were removed. The immunocytochemical characterization of the cells was carried out using various monoclonal antibodies in cryostat-cut sections. The distribution patterns of DCs and their major costimulatory molecules, CD80, CD86 and CD40 in the spleen were identified, and the evidence for maturation of DCs in vivo in response to SEB was obtained. It was found that systemic administration of SEB induced the migration of most of the immature, splenic DCs from the marginal zone to the periarterial lymphatic sheath within 6 hr. This movement paralleled a maturation process, as assessed by upregulation of CD40, CD80 and CD86 expression in the interdigitating dendritic cells (IDCs). The upregulation of costimulatory molecule expression was conspicuous only in DCs in contrast to other antigen-presenting cells (APCs) such as macrophages and B cells which did not show any significant alterations in their costimulatory molecule expression. We also demonstrated the temporal expression pattern of these costimulatory molecules on the activated DCs. The upregulation of costimulatory molecules on DCs reached a peak level 6 hr after SEB injection, while the increase in number of T cells expressing T cell receptor V138 reached a peak level on day 2 after SEB treatment. In conclusion, we demonstrated the in vivo DC response to SEB in the mouse spleen, especially a potent stimulative effect of SEB on DCs in vivo, a temporal distribution pattern of DCs as well as T cells including TCR Vbeta8+ T cells, and a differential expression pattern of costimulatory molecules on the activated DCs. The results of the present study indicate that DCs are the principal type of APCs which mediate T cell activation by SAg in vivo, and that each costimulatory molecule may have different role in the activation of DCs by SAg. Thus, it is plausible to speculate that DCs play a critical role in the T cell clonal expansion by SAgs and other SAg-induced immune responses in vivo.

MR findings of the spinal paraganglioma : report of three cases

Extraadrenal paragangliomas involving the spine is less common and usually takes the form of intradural compression of the cauda equina. The authors report three cases of spinal paragangliomas resulting in extradural spinal cord compression and their MR findings. The MR imaging revealed a well-demarcated extradural mass with low to intermediate signal intensity on T1-weighted images and intermediate to high signal intensity on T2-weighted images compared to paravertebral muscles. After Gd-DTPA administration, heterogeneous and intense enhancement was found. Multiple punctate and serpiginous structures of signal void due to high-velocity flow were noted around and within the tumors on all sequences. In one case, the signal void structures were well corresponded with feeding arteries on angiography. These may be the characteristic findings of the extraadrenal paraganglioma involving the spine.

Calsequestrin, a calcium sequestering protein localized at the sarcoplasmic reticulum, is not essential for body-wall muscle function in Caenorhabditis elegans

Calsequestrin is the major calcium-binding protein of cardiac and skeletal muscles whose function is to sequester Ca(2+)in the lumen of the sarcoplasmic reticulum (SR). Here we describe the identification and functional characterization of a C. elegans calsequestrin gene (csq-1). CSQ-1 shows moderate similarity (50% similarity, 30% identity) to rabbit skeletal calsequestrin. Unlike mammals, which have two different genes encoding cardiac and fast-twitch skeletal muscle isoforms, csq-1 is the only calsequestrin gene in the C. elegans genome. We show that csq-1 is highly expressed in the body-wall muscles, beginning in mid-embryogenesis and maintained through the adult stage. In body-wall muscle cells, CSQ-1 is localized to sarcoplasmic membranes surrounding sarcomeric structures, in the regions where ryanodine receptors (UNC-68) are located. Mutation in UNC-68 affects CSQ-1 localization, suggesting that the two possibly interact in vivo. Genetic analyses of chromosomal deficiency mutants deleting csq-1 show that CSQ-1 is not essential for initiation of embryonic muscle formation and contraction. Furthermore, double-stranded RNA injection resulted in animals completely lacking CSQ-1 in body-wall muscles with no observable defects in locomotion. These findings suggest that although CSQ-1 is one of the major calcium-binding proteins in the body-wall muscles of C. elegans, it is not essential for body-wall muscle formation and contraction.

Mutation and expression of the p27KIP1 and p57KIP2 genes in human gastric cancer

Cyclin-dependent kinase inhibitors (CDKI) are negative regulators of cell cycle progression by binding the cyclin-CDK complex and inhibiting the CDK activity. Genetic alteration in the CDKI genes has been implicated for carcinogenesis. To test the genetic alteration in the p27 and p57 genes, KIP family CDKI genes, 30 gastric tumor-normal pairs and 8 gastric cancer cell lines were analyzed for mutations by polymerase chain reaction-single strand conformational polymorphism (PCR-SSCP). No mutation was detected in these genes although length polymorphisms in the proline-alanine repeat of the p57 gene were detected. When the p27 and p57 mRNAs were analyzed in gastric cancer cell lines by RT-PCR, the p27 mRNA was expressed considerably high in tumor cells but expression of the p57 mRNA was much low in gastric cancer cell lines compared to that of normal cells. The result suggests that inactivation of gene expression rather than mutations in the p57 gene accounts possibly for the involvement of this gene in tumorigenesis of gastric cancer. However, expression of the p27 gene seems to be essential for cell survival.

Mechanism for inactivation of the KIP family cyclin-dependent kinase inhibitor genes in gastric cancer cells

The mechanism for inactivation of the KIP family cyclin-dependent kinase inhibitor (CDKI) genes, the p21, p27, and p57 genes, in gastric cancer cells was tested by treating the cells with either the DNA demethylation agent, 5-aza-2'-deoxycytidine or the histone deacetylase inhibitor, n-butyric acid or trichostatin A. RNA expression of the gene was determined by reverse transcription PCR. The p21 gene was activated only by histone deacetylase inhibitor. The p57 gene was activated by histone deacetylase inhibitors in all of the gastric cancer cell lines and by 5-aza-2'-deoxycytidine in five of eight gastric cell lines. However, the p27 gene was not inactivated in gastric cancer cell lines. The methylation status of the promoter of the p21 and p57 genes was also tested by digestion with the methylation-sensitive restriction enzymes and a subsequent PCR. The promoter of the p21 gene has no methylation. The promoter of the p57 gene is, however, methylated in five of eight gastric cancer cell lines as expected from the result of the treatment with 5-aza-2'-deoxycytidine. Formation of the inactive chromatin through histone deacetylation seems to be the general mechanism for inactivation of both the p21 and the p57 genes in gastric cancer cells. Hypermethylation of promoter region seems to be an alternative pathway for inactivation of the p57 gene.