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.

Sevoflurane versus propofol for interventional neuroradiology: a comparison of the maintenance and recovery profiles at comparable depths of anesthesia

Background

Sevoflurane and propofol are used widely for interventional neuroradiology (INR). Using the bispectral index (BIS), we compared the clinical properties of sevoflurane and propofol anesthesia in patients undergoing INR at comparable depths of anesthesia.

Methods

The patients were allocated randomly into two groups. The sevoflurane group received propofol (1.5 mg/kg), alfentanil (5 µg/kg), and rocuronium (0.6 mg/kg) for induction, and the propofol group was induced with a target effect-site concentration of propofol (4 µg/ml), alfentanil (5 µg/kg), and rocuronium (0.6 mg/kg). After intubation, anesthesia was maintained with sevoflurane or propofol with 67% nitrous oxide in 33% oxygen. Sevoflurane and propofol concentrations were titrated to maintain the BIS at 50-60. Phenylephrine or opioid was used to maintain the mean arterial pressure within 20% of the baseline values. The amounts of phenylephrine or alfentanil used, the number of patients showing movement during the procedure, and the recovery times were recorded.

Results

Compared to the propofol group, the sevoflurane group showed faster recovery in spontaneous ventilation, eye opening, extubation, and orientation (4 vs. 7 min, 7 vs. 9 min, 8 vs. 10 min, 10 vs. 14 min, respectively; P < 0.01). In the propofol group, significantly greater amounts phenylephrine were used (P < 0.05), and more patients moved during the procedure (P < 0.05).

Conclusions

The use of sevoflurane in maintaining anesthesia during INR was associated with faster recovery, less patient movement during the procedure, and a more stable hemodynamic response when compared to propofol.

An educational program that contributes to improved patient and parental understanding of atopic dermatitis

Background

Providing an educational program as part of a health care program for the management of atopic dermatitis (AD) patients has rapidly become popular. AD educational programs can be of benefit in measured outcomes for both dermatology specialists and patients.

Objective

To determine the effects of programmed education delivered by dermatology specialists on the management and knowledge of AD, we assessed the effectiveness of patient/parental education at improving AD knowledge, and determined the usefulness of the education.

Methods

The program consisted of five, 20-minutes sessions which were prepared, discussed, reviewed, and delivered by professors of dermatology. At the end of the program, AD knowledge was assessed using a standardized questionnaire. A total of 148 people were included. Fifty-eight patients/parents received the programmed education and the remaining 90 did not receive the programmed education.

Results

The mean questionnaire scores from both groups were compared. Mean knowledge scores were significantly higher for those who received the education (p=0.00). We analyzed the knowledge score according to factors such as gender, education level, marital status, and occupation. The data indicated that education level influences the subjects' knowledge level of AD, but gender, occupation, and marital status do not.

Conclusion

An educational program can be an effective tool to improve patient quality of life and treatment compliance by providing psychological support to the patients and their parents.

Referred pain in right arm from abdominal wall pseudoaneurysm

Pseudoaneurysm of the abdominal wall is a possible but very rare clinical entity. It is a known complication of surgery, trauma, or arterial puncture, but it is rarely spontaneous. Even though it can usually present with a wide range of local symptoms, it can cause referred pain via spinal cord, which is cross-excited with afferent sympathetic nervous system. We report a case of right arm pain which was referred from a small abdominal pseudoaneurysm like a referred pain from gall bladder. This rare entity should be considered in the differential for pain management in case that the pain does not resolve with medication or interventional pain management.

New world cutaneous leishmaniasis treated with intralesional injection of pentavalent antimony

Cutaneous leishmaniasis is a skin infection caused by the Leishmania species, an intracellular protozoan parasite that is transmitted by various species of female sandflies. According to the geographic distribution and vectors, leishmaniasis is classified as Old World or New World cutaneous leishmaniasis. In Korea, 24 cases of Old World cutaneous leishmaniasis have been reported, but New World cutaneous leishmaniasis has not been reported as yet. A 37-year-old man presented with a 3-month history of a painful and erythematous nodule with two satellite papules on the left postauricular area and a papule on the left arm after traveling to the Amazon region in Brazil. After we performed skin biopsies of the lesions, diagnosis of cutaneous leishmaniasis was made by the histopathological findings. After intralesional injection of sodium stibogluconate (Pentostam®, GlaxoSmithKline) twice a week for 4 weeks, the lesions improved with scarring. Herein, we discuss this case of New World cutaneous leishmaniasis that was successfully treated with intralesional injection of sodium stibogluconate (Pentostam®) in Korea.

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.

Replacement of a tracheal defect with a tissue-engineered prosthesis: early results from animal experiments

OBJECTIVES

The major problems in the development of tracheal prosthesis are anastomotic dehiscence and stenosis, caused by poor epithelialization of the prosthetic graft. We developed a novel tracheal prosthesis with viable mucosa transplanted from the oral cavity and reported excellent long-term results after thoracic tracheal replacements in dogs. In the current study, we used tissue-engineering techniques to construct a mucosal prosthetic lining from skin cells and evaluated its usefulness in tracheal replacement.

METHODS

Abdominal skin patches (5 x 10 cm) were harvested from 10 adult mongrel dogs. The epithelial cells were separated, cultured in vitro for 4 weeks, and then seeded onto a porous polylactic glycolic acid scaffold (6 x 8 cm) to construct a lining mucosa. This was then mounted onto the prosthesis framework, made with polypropylene mesh reinforced with polypropylene rings. The mucosa-lined prosthesis was wrapped with the greater omentum of the same dog and placed in the peritoneal cavity for 1 week. Complete surgical resection and replacement of a thoracic tracheal segment (5 cm in length, just above the carina) was then performed using the prosthesis.

RESULTS

The animals regained full activity and survived with normal activity. Bronchoscopy at 1 week and at 1 and 2 months revealed no stenosis in the anastomosis.

CONCLUSIONS

This highly biocompatible tracheal prosthesis could prove useful for the reconstruction of large, circumferential tracheal defects.

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.