Update on clarithromycin resistance in Helicobacter pylori in Hong Kong and its effect on clarithromycin-based triple therapy

AIM

To determine the antibiotic susceptibility of Helicobacter pylori and evaluate the efficacy of a clarithromycin-based triple therapy in relation to antibiotic resistance.

METHODS

Consecutive patients referred for upper endoscopy due to dyspeptic symptoms were recruited. Gastric biopsies were obtained for the CLO test, histology and culture. Antibiotic susceptibility was assessed by the E-test. Patients with H. pylori infection received rabeprazole 20 mg, clarithromycin 500 mg, and amoxicillin 1,000 mg, all twice daily for 7 days.

RESULTS

Of 234 patients recruited, 124 were H. pylori-positive and culture was successful in 102 patients. The updated prevalences of resistance to clarithromycin, amoxicillin and metronidazole were 7.8, 0 and 39.2%, respectively. A total of 86 patients received 1-week triple therapy with rabeprazole 20 mg, clarithromycin 500 mg, and amoxicillin 1,000 mg, all twice daily, and 81 patients attended the follow-up test. Eradication rates by per-protocol and intention-to-treat analysis were 92.6 and 87.2%, respectively. The eradication rate by per protocol was significantly higher in patients with clarithromycin-susceptible strains than in those with clarithromycin-resistant strains (98.6 vs. 28.6%, p < 0.001).

CONCLUSION

Clarithromycin resistance reduces the clinical efficacy of clarithromycin-based triple therapy. However, due to the low prevalence of clarithromycin resistance, clarithromycin-based therapy is still the first choice for clinical use.

Effect of cyclo-oxygenase inhibitors on Helicobacter pylori susceptibility to metronidazole and clarithromycin

BACKGROUND

We previously reported that aspirin inhibited Helicobacter pylori growth and suppressed the mutagenic effect of metronidazole.

AIM

To determine the effects of a cyclo-oxygenase (COX)-2-specific inhibitor, SC-236, and a non-selective COX inhibitor, indometacin, on the growth, urease activity and antimicrobial susceptibility of H. pylori.

METHODS

Three H. pylori reference strains, and 18 clinical isolates were treated with SC-236 or indometacin for 24 and 48 h. Growth, urease activity and susceptibility to clarithromycin and metronidazole of the bacteria were assessed by viable colony counting, spectrophotometry and E-test respectively.

RESULTS

SC-236 and indometacin inhibited H. pylori growth in a dose-dependent manner with the lowest inhibitory concentrations of 0.03 and 0.1 mm, and the lethal concentrations of 0.09 and 0.3 mm, respectively. The numbers of CFU/mL in Brucella broth containing 0.09 mm SC-236 were 2 log lower at 24 h, and even 3 log lower at 48 h than that at 0 h (P = 0.035, compared with the vehicle control). Treatment of 0.3 mm indometacin reduced the number of CFU/mL by 1 log at 24 h compared with that at 0 h (P = 0.037 compared with the vehicle control). Helicobacter pylori urease activity began to decrease with 0.06 mm SC-236 at 24 h (P = 0.016), and 0.3 mm indometacin at 48 h (P = 0.025). MICs of metronidazole and clarithromycin against H. pylori were decreased significantly in the presence of 0.03 mm SC-236 or 0.1 mm indometacin (all P < 0.001).

CONCLUSION

Both SC-236 and indometacin suppressed the growth and urease activity of H. pylori in a dose-dependent manner, and increased its susceptibility to the antibiotics.

Pharmacokinetics and Lipid-Lowering Effect of Fluvastatin in Hypercholesterolaemic Patients on Maintenance Haemodialysis

Patients undergoing haemodialysis are predisposed to serum lipid abnormalities that can accelerate the development of atherosclerosis. Serum lipid levels must therefore be controlled over a long period. For patients with reduced renal function (including dialysis patients), special attention must be paid to hyperlipidaemia therapy, particularly drug selection. In this study, 30 mg/day fluvastatin was administered orally to five patients receiving maintenance haemodialysis. Their serum lipid levels and blood biochemistry were monitored during the 6 months of fluvastatin administration, and the pharmacokinetic parameters calculated. The therapeutic efficacy and safety of fluvastatin were demonstrated in this patient group. Furthermore, fluvastatin is not influenced by the dialysis membrane and does not accumulate in haemodialysis patients with hyperlipidaemia.

Epithelial maturation and extracellular matrix in reduced enamel epithelium

OBJECTIVE

To evaluate epithelial-mesenchymal interactions in morphological homeostasis through histologically orientated observations on the reduced enamel in epithelium.

STUDY DESIGN

Specimens were taken from impacted molar sites in 20 patients using the surgery. These were processed using standard histological, pathological and biochemical techniques. Slides were observed with a Nikon Eclipse E-600, Plan Apo piece, Microscopy, and photography was done using a Nikon Coolpix 990 digital camera.

RESULTS

Radiolucent lesions displayed the supporting fibrous connective tissue wall with stratified squamous epithelium lining mostly. None of the specimens displayed prominent CAM 5.2, and anti-human K7 reacuvity, and PAS positive staining.

CONCLUSION

While the results of this study suggest that the reduced enamel epithelium showed a lower tendency in cell cycle, it does indicate that a histologically oriented study of reduced enamel epithelium is needed for the understanding of epithelial-mesenchymal interactions in morphogenesis.

Clinical spectrum of acute respiratory distress syndrome in a tertiary pediatric intensive care unit

Acute respiratory distress syndrome (ARDS) has been a great challenge in the field of pediatric critical care medicine. The clinical picture of children with ARDS in Taiwan has seldom been reported. The purpose of this study was to investigate the incidence, predisposing factors, clinical manifestations, strategies of ventilator support, adjuvant therapies, and prognosis of children with ARDS in a tertiary pediatric intensive care unit (PICU). A retrospective review of admissions to our PICU in the past 3 years showed that 16 cases met the criteria of pediatric ARDS. The incidence was 0.2% of all PICU admissions. The predisposing factors were varied, and pneumonia was the most common. The mean values of acute lung injury scores, ventilation indices and PaO2/FiO2 on admission were 3.6 +/- 0.5, 68.0 +/- 32.8 and 71.6 +/- 25.2, respectively. The averages of maximal peak inspiratory pressure (PIP) and positive end-expiratory pressure (PEEP) were 40.3 +/- 9.8 and 14.0 +/- 4.6 cmH2O, respectively. Only three patients (19%) expired due to overwhelming systemic infection. Compared with our previous high mortality rate report, we emphasized gentle mechanical ventilation care, early employment of high PEEP and adjuvant therapy with sodium nitroprusside (SNP) nebulization and/or inhaled nitric oxide (iNO) to achieve an improved survival rate.

Comparative evaluation of the BACTEC MGIT 960 system with solid medium for isolation of mycobacteria

SETTING

The utilisation of new, rapid methods of diagnosis of tuberculosis is currently of great interest for tuberculosis control. This study was carried out in a teaching hospital in the eastern region of Taiwan.

OBJECTIVE

The BACTEC MGIT 960 system was evaluated and compared with Lowenstein-Jensen (LJ) medium and Middlebrook 7H11 plate for recovery rate and time to detection of mycobacteria.

DESIGN

A total of 1396 sputum samples were tested for the presence of mycobacteria. Specimens were processed and inoculated separately in the BACTEC MGIT 960 system, on LJ medium and 7H11 for comparative study.

RESULTS

The BACTEC MGIT 960 detected 235 isolates (100%), followed by LJ with 205 isolates (87.2%) and 7H11 with 178 isolates (75.7%). The mean time to detection of Mycobacterium tuberculosis complex was 11.6 days with MGIT 960, 20.1 days with LJ, and 18.7 days with 7H11. The contamination rates were 15.1% with MGIT 960, 10.1% with LJ and 9.7% with 7H11.

CONCLUSION

The BACTEC MGIT 960 system is a sensitive, rapid mycobacterial culturing system. However, the high contamination rate is a concern that should be carefully evaluated in the clinical setting.

Verapamil Sensitive Idiopathic Ventricular Tachycardia in an Infant

Idiopathic ventricular tachycardia is rare, especially in infants. We report here on an 8 month-old female infant who presented with tachycardia with a heart rate of 186 beats/ min. An electrocardiogram showed a right bundle branch block pattern, a QRS duration of 80 msec, a superior QRS axis, atrioventricular dissociation, and occasional fusion and capture beats. Suspected ventricular tachycardia was treated with lidocaine, propranolol and amiodarone, but in vain. The tachycardia was terminated and well controlled with the use of verapamil. According to an electrocardiogram and her clinical response, verapamil-sensitive idiopathic ventricular tachycardia was diagnosed with the arrhythmic origin in the left posterior fascicle.

Validation of the World Health Organization quality of life instrument in patients with HIV infection

We studied the reliability and validity of the World Health Organization quality of life (WHOQOL) assessment instrument in patients with human immunodeficiency virus (HIV) infection. WHOQOL-BREF was used to assess 136 HIV-infected outpatients. The results were analyzed and compared with data from 213 healthy persons. The Cronbach's alpha for internal consistency ranged from 0.74 to 0.85 across domains in HIV-infected patients. The test-retest reliability ranged from 0.64 to 0.79 across domains at average 4-week retest interval. Factor analysis identified four major factors: social, psychological, environment, and physical, consistent with the four domains of the instrument. The scores of all four domains correlated positively with self-evaluated health status and happiness (r range: 0.52-0.60 and 0.55-0.73 across domains, respectively), and correlated negatively with the number and severity of symptoms (r range: -0.40 to -0.47 and -0.41 to -0.52, respectively). The scores of physical, psychological and social domains, but not the environment domain, discriminated between healthy persons and HIV-infected patients (all p < 0.01). We conclude that the WHOQOL-BREF can be a useful quality-of-life instrument in patients with HIV infection.

An alternative method to enhance vagal activities and suppress sympathetic activities in humans

Vagal withdrawal and/or sympathetic overactivity is always accompanied by various kinds of stress and is dangerous to the body. We proposed that mild acupuncture on the Sishencong points may effectively enhance vagal activities but suppress sympathetic regulations of the heart in humans. Experiments were carried out on nine healthy male volunteers, while they were lying in a quiet room during 2-4 P.M. Acupuncture was applied 2 mm deep into the skin using standard stainless acupuncture needles at the Sishencong points, which are located on the vertex of the head, each 1 cm away from Baihui (GV 20) in four directions. Four points around the temporal area were selected as control points. Forty minutes of precordial ECG signals before, during, and after acupuncture were recorded continuously. Frequency-domain analysis of the stationary RR intervals was performed to evaluate the total variance, high-frequency power (HF, 0.15-0.40 Hz) and low-frequency power (LF, 0.04-0.15 Hz) in normalized units (LF%). Acupuncture on the Sishencong points resulted in an increased HF but a decreased LF% compared with the before acupuncture stage. Such effects did not occur when manual acupuncture was applied to the control points. The differences in the heart rate dynamics between Sishencong and the control groups took place 10 min after initiation of acupuncture and persisted even after the removal of the needles. Based on these results, we concluded that manual acupuncture on the Sishencong points enhanced cardiac vagal and suppressed sympathetic activities in humans. The underlying mechanisms and potential applications warrant further investigations.

The differences between late graft loss group and long-term graft survival group in renal transplantation

In renal transplantation, the long-term graft survival rate has not been improved. Until now, the differences between late graft loss and long-term graft survival have still not been estimated thoroughly. We have attempted to define clinical risk factors and parameters for late graft loss by comparing the differences in these two groups. Data from the Osaka University Database were assessed on 156 renal allografts during a 7-yr period. Thirty-six patients comprised the late graft loss group (patients in this group had graft function without need for dialysis for more than 3 yr post-transplantation, afterwards lost the allograft: 'loss group'). One hundred and twenty patients comprised the long-term graft survival group (patients in this group had graft function without need for dialysis until 31 December 1999: 'survival group'). Various immunological and non-immunological parameters were included in an univariate regression analysis. This analysis showed that donor age (P < 0.01), HLA mismatch number (P < 0.01) and a repeat of acute rejection (P < 0.01) were significant factors. Serum creatinine levels at 3 months (P = 0.01), proteinuria at 1 yr (P < 0.01) and antihypertensive treatment at 2 yr (P = 0.03) after transplantation were predictive of the risk of late graft loss. CsA trough concentration at 3-6 months (P < 0.05) and body mass index increase at 1 yr (P = 0.046) were elevated in the loss group. These results from a single centre suggest that immunological as well as non-immunological factors are associated with the pathogenesis of late graft loss.

[Preparation and evaluation of alkyl ether-bonded phase for reversed-phase high performance liquid chromatography]

A new silane coupling agent, beta-(3,4-epoxycyclohexyl)ethyltrimethoxy silane, was for the firsty time used to react with octanol, then the intermediate product was coupled onto porous silica to obtain a novel bonded phase for reversed-phase high performance liquid chromatography (RP-HPLC). Characterization of prepared packing was carried out with elemental analysis, solid-state 13C nuclear magnetic resonance spectrometry (NMR), Fourier transform infrared(FT-IR) spectroscopy. Chromatographic evaluations were carried out by using a mixture of organic compounds and methanol-water as the binary mobile phase. The results showed that the stationary phase has excellent chromatographic properties and resist to hydrolysis at a pH value between 2.5 and 7.5. The silanophilic activity of the OEBP was weakened because of the existence of the cyclohexyl group in the packing. It can be efficiently used for the separation of basic compounds.

Changes in lipid metabolism and effect of simvastatin in renal transplant recipients induced by cyclosporine or tacrolimus

Hyperlipidemia is frequently developed following renal transplantation and results in worsening of the patient's prognosis. In study 1, the effects of immunosuppressants, cyclosporine (CsA) and tacrolimus on serum lipids were compared in-patients undergoing renal transplantation. The study included 32 cases of renal transplantation recipients who randomized to the CsA treatment group (15 patients) and the tacrolimus group (17 patients). Before and 1 month after the transplantation, we assessed the serum lipid levels, apolipoprotein levels, the concentrations of cholesterol in the respective lipoprotein fractions and the enzyme activities related to lipid-metabolism. The serum lipid levels in both groups were significantly increased at 1 month after renal transplantation. In the CsA group, there were significant increases in cholesterol contents in very-low-density lipoprotein (VLDL), LDL2 and HDL2 fractions, whereas, in the tacrolimus group, cholesterol content was increased in VLDL and HDL2 fractions. In study 2, 1 month after renal transplantation, 19 patients with hypercholesterolemia (total cholesterol (TC) >200 mg/dl) and hypertriglyceridemia (triglyceride (TG) >150 mg/dl) were treated with simvastatin 5-10 mg/day for 6 months. Simvastatin treatment significantly decreased serum TC (240+/-29-200+/-22 mg/dl, P<0.001), low-density lipoprotein cholesterol (LDL-C; 114+/-20-99+/-17 mg/dl, P<0.05) and TG levels (217+/-103-130+/-38 mg/dl, P<0.01). In addition, there were significant decreases in very-low-density lipoprotein cholesterol (VLDL-C; 53+/-20-34+/-15 mg/dl, P<0.001). The Cmax and AUC of simvastatin were increased about eight-fold, when simvastatin was given in combination with CsA. In contrast, no significant changes in simvastatin levels were observed when combination with tacrolimus. Although simvastatin levels were increased with CsA, there were no abnormal changes in renal and liver functions, creatinine phosphokinase (CPK) levels or in incidence of adverse effects.

[Using genetic algorithm for quantitative analysis of overlapped spectra in FTIR]

Technique for the quantitative analysis of FTIR spectra, which are serious overlapped in the spectral bands, is studied by genetic algorithm. The multicomponent in the mixture, which contains ten air toxic organic components, such as benzene, phenixin, chlorobenzene, nitrobenzene, phenol, toluene, methanol, o-cresol, m-cresol and p-cresol, is simultaneously determined. The effect of the probability of crossover and the establishment of objective function are discussed. The method of adaptive mutation is used. The results indicate that genetic algorithm has excellent non-linear ability of solution. Mean relative error of each results is really small, generally not bigger than 1%, when the conditions are properly controlled.

[Preparation and evaluation of amide-octyl-bonded phase for the separation of basic substances in reversed-phase liquid chromatography]

A new bonded-phase, amide-octyl-bonded phase (AOBP), with an internal polar functional group-amide was firstly prepared in domestic by two-step reaction process. The amino phase was formed in the first step and further modified in the second step by attaching an alkyl chain via reaction of an acid chloride with the amino ligand. Characterization of prepared packing was carried out with elemental analysis and Fourier transform infrared (FTIR) spectrometry. Hydrophobicity, selectivity and silanophilic activity of AOBP were evaluated by using organic components including acidic, bascic and neutral analytes and methanol-water as binary mobile phase. The applicable ranges of pH and stability of AOBP were also evaluated. The results showed that AOBP has excellent chromatographic properties and resistance to hydrolysis between pH = 2.5-7.5, It can be used for the separation of basic solutes efficiently.

Impact of age on the injury pattern and survival of people with cervical cord injuries

STUDY DESIGN

A retrospective, follow-up study.

OBJECTIVES

To differentiate the injury pattern and survival of people with cervical cord injuries with onset at different ages.

SETTING

Rehabilitation wards of a university hospital that is a tertiary referral center in Taipei, Taiwan.

METHODS

The records of acute and traumatic cervical cord injury patients hospitalized from 1989 to 1997 were reviewed. All subjects received comprehensive rehabilitation programs during hospitalization. Their survival status at the end of follow-up was studied.

RESULTS

Forty-seven of 109 (43.1%) people with cervical cord injuries were 50 years or older at onset. Older patients were more frequently injured by minor falls, resulting in more incomplete quadriplegia. They also showed fewer spinal fractures, and more demonstrated associated spondylosis and ossification of the posterior longitudinal ligament. Eleven (10.2%) subjects were deceased, found by a linkage to a death registration database at the end of follow-up. The significant predictor of survival status at follow-up was older age at injury using Cox proportional hazards model.

CONCLUSION

Spinal cord injured patients had different injury patterns, demanding different preventative strategies. Those injured at older ages were at higher risk of mortality according to our study.

SPONSORSHIP

This study was supported in part by grants from the National Taiwan University Hospital (89S2005), Taipei, Taiwan.

Clinicopathological evaluation in non-episode biopsies of renal transplant allograft

Histopathological findings in renal allograft with stable function remain unclear. We therefore performed non-episode biopsy in the long-surviving renal allograft to investigate the histopathological changes. Our data show that, although arteriolopathy is characteristic of drug-induced nephropathy, it is unrelated to dosage and concentration of cyclosporine or tacrolimus in non-episode biopsy. We evaluated therefore the clinicopathological findings of arteriolopathy in this study. Non-episode biopsy was defined as follows: as serum creatinine level lower than, 2.0 mg/dl and a urinary protein level lower than 500 mg/day. A total of 65 biopsy specimens were enrolled in this study as non-episode biopsy. Twenty-nine specimens revealed arteriolopathy. There were no statistically significant differences between arteriolopathy and dosage or concentration of cyclosporine or tacrolimus. Arteriolopathy in non-episode biopsy was related to time of biopsy, kidney age, hypertension, and hyperlipidemia, suggesting that it is important for graft survival to strictly control blood pressure and blood lipid level.

Factors influencing vertebral bone density after renal transplantation

To improve our understanding of the mechanisms underlying osteoporosis following renal transplantation, we compared bone mineral density (BMD) in 158 transplant recipients and in 293 patients undergoing maintenance hemodialysis with age- and sex-matched normal controls. Observations in graft recipients were made up to several years following transplantation. Dual-energy X-ray absorptiometry was used to measure BMD. Correlations with clinical variables including serum concentration of parathyroid hormone (PTH) and steroid therapy were evaluated. Lumbar BMD was lower in transplant patients than in dialysis patients at all ages, and continued to decrease with increasing interval posttransplant until the second year after transplantation. Persistent hyperparathyroidism and daily prednisolone dosage were both associated with decreased BMD. Age and creatinine clearance were independent long-term predictors of BMD by multiple regression analysis. Treatment of renal graft recipients with calcium and vitamin D supplements or calcitonin may be indicated in the early months after transplantation.

Arteriolopathy in non-episode biopsies of renal transplant allograft

PURPOSE

We have been performing protocol biopsies since 1995 to predict the outcome of renal allograft. However, histopathological findings in renal allograft with stable function remain unclear. For this reason, we performed non-episode biopsy on long-surviving renal allograft and investigated the histopathological changes. Among the several diseases seen in non-episode biopsies, arteriolopathy, such as drug-induced nephropathy, is one of the most frequent diseases. However, it is unrelated to the dosage and the concentration of cyclosporine or tacrolimus. Consequently, we evaluated the clinicopathological findings of arteriolopathy in this study in order to clarify whether cyclosporine (CsA) or tacrolimus (FK506) is responsible for these findings.

MATERIALS AND METHODS

We defined non-episode biopsy as a case with a serum creatinine level less than 2.0 mg/dL and containing less than 500 mg/dL of urinary protein. Final results showed that 71 cases were identified as non-episode biopsy. We then evaluated the histopathological findings and the clinical characteristics of these cases.

RESULTS

Thirty-two of the 71 non-episode biopsy specimens showed findings of arteriolopathy. The frequency and the severity of arteriolopathy are not concerned with dosage and concentration of CsA or FK506. The arteriolopathy seen in non-episode biopsy was related to the time of the biopsy and the kidney age. Arteriolopathy in nonepisode biopsy also had a relationship with hypertension, suggesting that it is important to strictly control blood pressure for graft survival.

[Purification of proteins in human plasma with new nylon affinity membranes]

A series of affinity membranes were prepared by using microporous nylon membrane as matrix and activation method with s-triazine and 1,4-butanediol diglycidyl ether, separately. Three proteins with clinic value, gamma-globulin, plasminogen and thrombin, were purified from human plasma by one step with affinity membrane chromatography. The purities of gamma-globulin purified were higher than 83%, and purification folds were higher than 5. The purity of gamma-globulin obtained was higher than that of standard human gamma-globulin. The efficiencies of gamma-globulin purification with affinity membranes prepared by two activation methods were equal. Plasminogen purified with affinity membranes prepared by s-triazine activation was higher than that by 1,4-butanediol diglycidyl ether activation. And SDS-PAGE analysis showed that the purities of gamma-globulin and plasminogen obtained were higher than that of the commercial product. In addition, the purification of thrombin from human plasma by one step with trypsin activation column and affinity membrane was studied. Thrombin with specific activity of 42 NIH unit/mg and 42.5 NIH unit/mg could be obtained from human plasma through affinity membranes prepared by s-triazine and 1,4-butanediol diglycidyl ether methods, respectively.

Rapid and simultaneous determination of mycophenolic acid and its glucuronide conjugate in human plasma by ion-pair reversed-phase high-performance liquid chromatography using isocratic elution

A high-performance liquid chromatographic method has been developed for the simultaneous determination of mycophenolic acid (MPA) and its glucuronide conjugate (MPAG) in human plasma. The method involves protein precipitation with acetonitrile, followed by ion-pair reversed-phase chromatography on C18 column, with a 40 mM tetrabutyl ammonium bromide (TBA)-acetonitrile (65:35, v/v) mobile phase. A 20-microl volume of clear supernatant was injected after centrifugation, and the eluent was monitored at 304 nm. No interference was found either with endogenous substances or with many concurrently used drugs, indicating a good selectivity for the procedure. Calibration curves were linear over a concentration range of 0.5-20.0 microg/ml for MPA and 5-200 microg/ml for MPAG. The accuracy of the method is good, that is, the relative error is below 5%. The intra- and inter-day reproducibility of the analytical method is adequate with relative statistical deviations of 6% or below. The limits of quantification for MPA and MPAG were lower than 0.5 and 5.0 microg/ml, respectively, using 50 microl of plasma. The method was used to determine the pharmacokinetic parameters of MPA and MPAG following oral administration in a patient with renal transplantation.

[Sensitive and rapid analysis of nitrophenols and herbicides by capillary zone electrophoresis (CZE)]

11 Nitrophenols and some acidic herbicides have been separated by modified CZE. Good separation of such compounds can be achieved in less than 10 min by simply modifying the run buffer with organic solvents such as methanol, acetonitrile in a concentration of 40% (V/V). The limits of detection (LODs) for nitrophenols by UV-absorption at 215 nm were 0.5 mg/L-1.1 mg/L. Solid phase extraction was used to preconcentrate nitrophenols and some herbicides to reach an LOD at microgram/L levels. Typical samples have been analyzed.

Differences in binding of glucocorticoid receptor to DNA in chronic renal graft rejection

Although chronic rejection is the most common reason for late allograft loss, its pathophysiology and etiology are unclear. Attempts to prevent chronic rejection are now focused on the modulation of transcriptional regulation. We evaluated the ability of glucocorticoid receptors (GR) to bind to the DNA binding site in peripheral blood mononuclear cells (PBMC) of five patients with chronic rejection and seven without it. Using an electrophoretic mobility shift assay, we measured the amount of nuclear glucocorticoid receptor capable of binding to its specific DNA recognition sequences, termed glucocorticoid response elements (GRE). GR binding was significantly greater in control patients than in those with chronic rejection (P < 0.01). The retarded band was almost undetectable in two patients with chronic rejection even though they were taking more prednisolone than the seven control patients, all of whom had clearly identifiable retarded bands. These results suggest a decreased ability of GR to bind to GRE in chronic rejection, resulting in a reduced ability to block key proinflammatory promoter sites. This reduced binding may be one molecular basis of chronic rejection.

Rapid and simple determination of mycophenolic acid in human plasma by ion-pair RP-LC with fluorescence detection

Mycophenolic acid (MPA) is an immunosuppressive drug given as the prodrug of mycophenolate mofetil (MMF). In order to investigate the pharmacokinetics of MPA, a simple, specific, sensitive and reliable method has been established for the quantitative determination of MPA in plasma from renal transplant recipients. The method involves a single-step protein precipitation procedure and a specific determination by ion-pair reversed-phase high-performance liquid chromatography (HPLC) with fluorescence detection. Separation was achieved on a C18 column (150 x 4.6 mm, 5 microm) with a mobile phase composed of borate buffer (pH 10.0; 50 mM)--acetonitrile--tetrabutylammonium bromide (200 mM) (75:25:1, v/v/v). The fluorescence detector was set at 310 (excitation) and 430 nm (emission). Following protein precipitation with ice-cold acetonitrile, clear supernatants (50 microl) were injected into the HPLC system. The retention time of MPA was approximately 4.5 min. The HPLC run time was 8 min. The assay was linear in concentration range 0.2-20.0 microg/ml for MPA in human plasma. Precision of the assay in the concentration range examined was from 0.89 to 3.21% for the intra-assay run and from 3.01 to 4.35% for the inter-assay run. A limit of detection was 0.05 microg/ml at a signal-to-noise ratio of 3. This validated method was then applied to the determination of MPA concentrations in renal transplant recipients after oral administration of 0.75 g of MMF.

Chronic cyclosporin-induced nephropathy

AIMS

There is still no consensus about the prognostic influence of chronic nephropathy induced by low-dose maintenance therapy with cyclosporin. Our aim was to investigate the prognostic effect of cyclosporin nephropathy in Japanese renal transplant recipients.

MATERIAL

We retrospectively investigated the clinical records of 1,323 kidney transplant recipients who received cyclosporin at 65 institutions in Japan from 1982 to 1991.

METHOD

Renal biopsy was performed in 461 patients.

RESULTS

At 5 years and 9 years after transplantation, the patients who had cyclosporin nephropathy associated with immunological rejection, glomerulonephritis, or both showed a significantly worse prognosis than those with cyclosporin nephropathy alone (p < 0.01). There was no significant difference in the loss of renal function at 9 years after transplantation between patients showing no abnormalities and patients with cyclosporin nephropathy alone. Even when cyclosporin nephropathy was absent, the long-term prognosis was unfavorable in recipients with immunological rejection or glomerulonephritis.

CONCLUSIONS

These results suggest that cyclosporin nephropathy does not influence the prognosis of renal transplantation in patients on low-dose maintenance therapy with cyclosporin.

A simple self-rating assessment method of residual work capability for occupational permanent disabilities

BACKGROUND

To explore the validity, reliability, and determinants of a simple self-rating assessment method of residual work capability (RWC) after occupational permanent disabilities.

METHODS

Five hundred and thirty-nine compensated permanent disability workers answered three consecutive visual analogue questionnaires wherein they self-rated their residual work capability in terms of speed (RWCS), quality (RWCQ) and a combination of speed and quality (RWCC). At two major hospitals in Taiwan, 169 of these subjects were evaluated with physical capacity assessment (PCA), cognition and sensation assessment (CSA), the work ability index (WAI), and the 12-item Chinese health questionnaire (CHQ-12).

RESULTS

High test-retest reliability (Pearson's correlation coefficient 0.77) and satisfactory concurrent validity were shown for RWCS and RWCC. All PCA, CSA and WAI showed significant correlation with RWCs, while CHQ-12 displayed borderline correlation. Employment status after injury and status of the victim's salary as the main source of income for his/her family before injury, were the major determinants of RWCs, in addition to the scales of PCA, CSA and WAI.

CONCLUSIONS

The RWCC resulting from the self-rating method may be used as a simple assessment of a victim's residual work capability after occupational permanent disabilities.

[Renovascular hypertension]

Renovascular disease is one of the most common causes of secondary hypertension. Recent technical advances have changed the management principles, which include a more aggressive approach to the diagnosis and treatment of renovascular hypertension (RVH). We experienced a total of 95 cases with RVH between 1958 and 1999. The mean age of all patients was 31.8 years old, ranging from 3 to 64 years. The three major basal diseases that caused RVH were fibromuscular dysplasia (34/95), arteriosclerosis (26/95), and aortitis (12/95). Ninety-two kidneys were treated in 79 of the 95 patients. The major therapeutic modalities performed were reconstruction of renal artery (6/79), nephrectomy (21/79), autotransplantation (26/79), and percutaneous transluminal angioplasty (PTA) (25/79). PTA is now the treatment of choice for the initial management of patients with RVH. Surgical treatment is generally reserved for patients in whom PTA fails. Pharmacotherapy is used on patients awaiting angioplasty or revascularization, those who are too ill for intervention, and those who have failed to respond to intervention.

Vibration perception thresholds in workers with long term exposure to lead

OBJECTIVES

To evaluate the impact of long term occupational exposure to lead on function of the peripheral nervous system as reflected by vibration perception threshold (VPT), measured with a portable vibrameter.

METHODS

217 Workers in a lead battery factory were required to have an annual blood lead measurement during each of the 5 years preceding this study. All were invited to take the VPT test. A total of 206 workers were studied. The associations were analysed between VPTs and current blood lead concentration, mean concentration of blood lead over the past 5 years, maximum blood lead concentration during the past 5 years, index of cumulative blood lead (ICL), time weighted index of cumulative blood lead (TWICL), and percentage of lifespan spent at work in the plant, as well as the other potential confounders. Ordinary multiple regressions, generalised additive models, and hockey stick regression analyses were used to explore the potential existence of a threshold effect of blood lead variables on VPT.

RESULTS

VPT at a frequency of 220 Hz ranged from 6 to 100 (10(-2) g, or 0.098 m/s(2)) with a mean (SD) of 19.8 (14.2) for the feet and from 4 to 43 with a mean (SD) of 10.2 (6.1) for the hands. The five variables of exposure to lead were all significantly correlated with VPT of the feet but not the hands. In multiple linear regression analyses, the mean of the blood lead concentrations and the TWICL were significantly associated with VPT of the feet. The relation between VPT of the feet and mean blood lead was shown to be a J shaped curve with a generalised additive model and local smoothing technique. In the hockey stick regression, evidence was found of a threshold effect at a mean blood lead concentration of 31 microgram/dl. Above this threshold it was estimated that each increase of 1 microgram/dl mean blood lead over 5 years would increase VPT of the feet by 0.29 (10(-2) g) or 0.028 m/s(2) (at a frequency of 220 Hz) with other potential confounders held constant.

CONCLUSION

This study suggests that measurement of vibration sensory threshold is a relatively effective tool for detecting lead neuropathy in field studies, and that lead might cause sensory neuropathy with an effect threshold corresponding to a 5 year mean blood lead concentration of 31 microgram/dl.

Dimethylacetamide, ethylenediamine, and diphenylmethane diisocyanate poisoning manifest as acute psychosis and pulmonary edema: treatment with hemoperfusion

CASE REPORT

A 27-year-old man, employed by a synthetic fiber company, had been exposed to dimethylacetamide, ethylenediamine, and diphenylmethane diisocyanate in a confined space continuously for 4-6 hours per day for 3 days before admission. Hallucinations and delusions were noted at admission; pulmonary edema developed subsequently. The electroencephalogram showed diffuse moderate cortical dysfunction and slow waves at 4-7 Hz, 20-80 microV. Seizures, liver injury, and rhabdomyolysis were noted on the 4th hospital day. The patient was treated by hemoperfusion with a decrease in urine dimethylacetamide from 3,265 mg/g to 4 mg/g creatinine over 4 days. Serial urinary dimethylacetamide and electroencephalogram correlated with the clinical condition.

[Recent advances of silica packing in high performance liquid chromatography]

Developments of silica packings in high performance liquid chromatography are reviewed with 65 references. Preparative and modification methods of silica packings are introduced. The physical characterization on silica surface is elucidated. The applications of silica packings in HPLC are outlined and the trends of silica packings in China are described.

Subject-domain approach to the study of air pollution effects on schoolchildren's illness absence

In this paper, the authors propose a new statistical modeling technique, the subject-domain approach, which is theoretically proven to be equivalent to the time-domain approach in detecting an association between exposure and response with time trends. The authors use an empirical data set from a school absence monitoring study conducted during the 1994-1995 school year in Taiwan to demonstrate this subject-domain approach's application to environmental epidemiologic studies. Because the subject-domain models can control the influential personal confounding factors in the models, they show greater statistical power than the traditional time-domain approaches in determining the relation between air pollution and illness absences. The authors' models found that the schoolchildren's risks of illness absence were significantly related to acute exposures to nitrogen dioxide and nitrogen oxides with a 1-day lag (p < 0.01) at levels below the World Health Organization's guidelines. By contrast, the authors could not detect significant associations between air pollution and schoolchildren's absenteeism using time-domain approaches. Such findings imply that the models built on subject domain may be a general solution to the problem of the ecologic fallacy, which is commonly encountered in environmental and social epidemiologic studies.

Mother's willingness to pay for her own and her child's health: a contingent valuation study in Taiwan

We use the contingent valuation (CV) method to estimate mothers' willingness to pay (WTP) to protect themselves and their children from suffering a minor illness-a cold-in Taiwan. WTP is specified as a hedonic function of the duration and severity of the cold (measured alternatively by symptoms experienced and the Quality of Well-Being (QWB) index) and of respondents' socioeconomic characteristics. The average mother is willing to pay more to protect her child than herself from suffering a cold. Median WTP to avoid the average mother's and child's colds are US$37 and US$57, respectively. Adjusting for the greater duration and severity of the average mother's cold suggests that WTP to prevent comparable illnesses is approximately twice as large for the child as for the mother. We also find that mother's WTP is about 20% greater to prevent a son's than a daughter's illness.

Diagnosis and monetary quantification of occupational injuries by indices related to human capital loss: analysis of a steel company as an illustration

Prevention of occupational injuries is an important task of human resource management. In this study, new indices of human capital loss of occupational injury including cumulative injury rate, proportion of potential workdays lost, and potential salary lost were applied to the analysis of registry data of occupational injuries from 1986 to 1994 of a steel company in Taiwan. In addition, we compared these indices with disabling frequency rate and severity rate. The results showed that the average disabling frequency rate and cumulative injury rate of the whole company were 4.12 and 0.41, respectively; and the average disabling severity rate and proportion of potential workdays lost of the whole company were 563 and 229 x 10(-6), respectively, during 1986-1994. There was no consistent improvement in occupational safety in this period. The average potential salary lost of the whole company was more than US$ 2 million per year with a discount rate of 0.04, which was equivalent to 92 times of average annual income of a worker. The major monetary loss were due to non-traffic injuries of operators and traffic injuries of non-operators, which amounted to US$ 145 and 152 per person per year. As the new indices can provide additional information on lifetime occupational risk and human capital loss in monetary values, we concluded that they may be useful supplementary tools for monitoring and analyzing occupational injury data in a company.

New affinity nylon membrane used for adsorption of gamma-globulin

Microporous polyamide membranes were first modified by acid hydrolysis and subsequently bound with hydroxy-ethylcellulose to amplify reactive groups and reduce nonspecific interactions with proteins. Then 1,6-diaminohexane as space arm and phenylalanine as ligand were immobilized onto the nylon membranes by s-triazine trichloride activation. Affinity membranes thus obtained were set in a stack and used to adsorb gamma-globulin. The adsorption capacity (qm) of the affinity membrane is 53 micro gamma-globulin per m2 membrane and the desorption constant (Kd) is 2.35 x 10(-6) mol/l. The effects of feed, washing and elution rates on adsorption and desorption behavior were investigated. The results showed that affinity purification through these membranes could not be operated at very high flow-rates. A stack of 20 membranes with 47 mm diameter can adsorb 7.8 mg gamma-globulin with a purity of 91.6% from 4 ml of human plasma in a single-pass mode.

Oligosaccharides from Hoya carnosa

Oligosaccharides A, B, and C (1-3, respectively) were isolated from the stem of Hoya carnosa. Their structures were established by NMR and chemical methods. Compounds 1 and 2 were 6-deoxy-3-O-methyl-beta-allopyranosyl(1-->4)-beta-cymaropyranosyl( 1-- >4)-beta-cymaropyranosyl(1-->4)-beta-cymaronic acid delta-lactone and 6-deoxy-3-O-methyl-beta-allopyranosyl(1-->4)-beta-oleandropyranosyl++ +(1 -->4)-beta-cymaropyranosyl(1-->4)-beta-cymaronic acid delta-lactone, respectively. Compound 3 was the sodium salt of 2.

Plaque pH and associated parameters in relation to caries

Intensified plaque acidogenicity in caries-prone subjects was reported many years ago, but emerging evidence has suggested that the relationship may not be as strong as once thought. We have now determined a range of acidogenicity variables in subjects having both caries prevalence and incidence data, and have included plaque mineral data in the analysis. pH measurements were made in 20 randomly selected subjects from a high-caries group (mean DMFS = 8. 95) and 20 from a caries-free group of Beijing children aged 12 years participating in a caries prediction study. Subgroups with a 12-month DMFS increment >/=2 or = 0 were also formed from the two groups, respectively. Measurements were made with an iridium oxide electrode inserted between teeth 13/14, 23/24, 34/35 and 44/45, before and every 5 min for 30 min after rinsing with 10% sucrose, and the 4 resulting 'Stephan curves' averaged using a plaque pH analysis program. Supragingival plaque was collected from buccal and lingual smooth surfaces of posterior and upper anterior teeth and its acid extract analysed for Ca, P and F. Caries-free subjects (based on past experience) had a significantly higher maximum plaque pH and pH value after 30 min (reflecting a faster return to resting pH), a lower minimum enamel dissolution capacity of plaque and recorded less time below pH 7.0 than did high-caries subjects. No other differences were significant, including those of the principal acidogenic parameters 'minimum pH attained after a sugar rinse', 'curve area below the critical pH of 5.5' and 'time below the critical pH'. Selection of the caries groups on the basis of both experience and incidence did not reveal significant differences in more parameters. Upper arch plaque was significantly more acidogenic than lower arch plaque, and there was a consistently strong association between upper and lower arch values in individuals. Ca, P and F in the subjects' plaque had little or no influence on the principal acidogenic parameters. Our failure to find a relationship between caries prevalence or activity and these principal acidogenicity parameters may be related to differences between fissure and smooth surface plaque, temporal variations in acidogenicity and/or to use of F toothpaste during the 1-year observation period. These results support the view that factors such as the frequency of acidogenic episodes may be more important in caries progression than the degree of acidogenicity during any one episode.

Short-term effect of ozone on the pulmonary function of children in primary school

The objective of this study was to evaluate the short-term effect of ambient air pollution on the pulmonary function of schoolchildren. We sampled 941 children in primary school in three communities in Taiwan (Sanchun, Taihsi, and Linyuan). The nearby stations of the Taiwan air quality monitoring network provided the hourly ambient concentrations of sulfur dioxide, carbon monoxide, ozone, particulate matter < or = to 10 microm in aerodynamic diameter, and nitrogen dioxide. Spirometry was performed once for each sampled child. We also obtained the status of indoor air pollution and chronic respiratory disease history by using a structured questionnaire. Multivariate linear model analysis was used to evaluate pulmonary function effects of each pollutant in addition to determinants of indoor air pollution and meteorologic conditions. We found a significantly negative association of peak O(3) concentration on the day before spirometry with individual forced vital capacity and forced expiratory volume in 1 sec. The decrease in children's lung function can occur at peak hourly O(3) concentrations < 80 ppb. The slope of lung function decrease for Taiwanese children is approximately 1 mL/ppb for peak hourly O(3) exposure.

Inhibition of DNA synthesis in isolated human endometrial cells by a levonorgestrel-releasing intrauterine device

OBJECTIVE

To estimate the effect of an intrauterine device (IUD) releasing 20 micrograms levonorgestrel (LNG) per 24 hours on DNA synthesis in human endometrial cells before and after 12 months of use.

STUDY DESIGN

Endometrial specimens were collected from the anterior or posterior wall of the miduterus from 6 females on cycle day 10-12 before insertion of the IUD and after 12 months of use.

RESULTS

Previous results from our group did not reveal any influence on endometrial DNA cell content when a levonorgestrel IUD releasing 2 micrograms/24 h was used for 12 months in a group of fertile females. In this study, the IUD release rate, 20 micrograms LNG/24 h, was statistically significantly different from the results in the previous studies. The effect of the levonorgestrel IUD on endometrial proliferation was dose dependent, and a significant correlation could be found between continuous exposure to LNG and inhibition of DNA synthesis in endometrial cells.

CONCLUSION

Inhibition of proliferative activity in endometrial cells seems to be reflected by a decrease in DNA synthesis per cell nucleus and contributes to the clinical performance of the LNG-releasing IUD.

Monte Carlo estimation of extrapolation of quality-adjusted survival for follow-up studies

The expected quality-adjusted survival (QAS) for an index population with a specific disease can be estimated by summing the product of the survival function and the mean quality of life function of the population. In many follow-up studies with heavy censoring, the expected QAS may not be well estimated due to the lack of data beyond the close of follow-up. In this paper, we first created a reference population from the life tables of the general population according to the Monte Carlo method. Secondly, we fitted a simple linear regression line to the logit of the ratio of quality-adjusted survival functions for the index and reference populations up to the end of follow-up. Finally, combining information on the reference population with the fitted line, we predicted the expected quality-adjusted survival curve beyond the follow-up period for the index population. Simulation studies have shown that the simple Monte Carlo estimation procedure is a potential approach for estimating expected QAS and the survival function beyond the follow-up with a certain degree of accuracy.

Long-term effect of increased lead absorption on intelligence of children

The authors examined the reversibility of cognitive impairment caused by a mild increase in lead absorption among children. The results of our initial study revealed that air and soil outside a lead-recycling plant in Taiwan were seriously contaminated by lead, which was associated with lowered intelligence quotients of 32 children who attended a nearby kindergarten (i.e., kindergarten A). Thirty-five children-who were comparable with respect to age, sex, birth order, sibling number, and parental education level-from another kindergarten (i.e., kindergarten B) located 5 km from the plant were enrolled as the reference group. Following the initial study, kindergarten A school children moved 2 km from the lead-recycling plant. Twenty-eight children in each group were followed successfully 2.5 y later. Blood lead, intelligence quotient, and intelligence quotient-related factors were reassessed. The results showed that the average blood lead level of the exposed pupils dropped 6.9 microg/dl (standard deviation [SD] = 3.9 microg/dl) (p < .001), and the average intelligence quotient increased 11.7 points (SD = 13.2) (p < .01), compared with the results of the initial study. The average blood lead level of the reference group decreased by 1.7 microg/dl (SD = .1.3) (p < .001), whereas the average intelligence quotient increased by 4.2 points (SD = 13.8) (p = .115). There was a significant difference in intelligence quotients between the two groups during the initial study, but the difference subsequently disappeared during the follow up. The authors concluded that intelligence quotient impairment, caused by a mild subclinical elevation of blood lead (i.e., likely no more than 30 microg/dl) for a period of 1-3 y in 3- to 5-y-olds, is at least partially reversible.

Early induction of apoptosis in androgen-independent prostate cancer cell line by FTY720 requires caspase-3 activation

BACKGROUND

We previously reported that FTY720, a metabolite from Isaria sinclairii, induced some cancer cells to undergo apoptosis, and that FTY720-induced apoptosis was not related to Fas-antigens. In this study we investigated whether FTY720 was able to induce apoptosis in an androgen-independent prostate cancer cell line, DU145, which is not only resistant to androgen-withdrawal-induced apoptosis but also Fas- and TNF-alpha-mediated apoptosis.

METHODS

Cell survival and morphological change were examined and apoptosis was confirmed by DNA isolation and analysis of DNA fragmentation. Caspase activation was studied by using anti-caspase-1 and anti-caspase-3 antibodies. To determine whether caspase activation is central to FTY720-induced apoptosis, caspase inhibitor was added to the media 24 hr prior to the addition of FTY720.

RESULTS

We found that FTY720 rapidly induced apoptosis in DU145 cells, and that caspase-3 was activated during FTY720-induced apoptosis. In contrast, normal human prostate stromal cells were resistant to FTY720. Furthermore, FTY720-induced apoptosis was prevented by caspase-3 inhibitor.

CONCLUSIONS

The data in this report show that FTY720 is a potential strong antitumor agent for cell line DU145, and provide the first evidence for involvement of caspase-3 in apoptosis of an androgen-independent prostate cancer cell line. Activation of such caspases may provide a means for eliminating androgen-independent prostate cancer in humans.

Relationship of blood lead levels to personal hygiene habits in lead battery workers: Taiwan, 1991-1997

BACKGROUND

The blood lead concentrations of workers in lead battery factories are more than 4 times higher than those of the general population in Taiwan. Therefore, efforts are needed to reduce lead exposure in this high-risk population. A health promotion program on personal habits that reduce lead exposure has been carried out in a lead battery factory since 1991. This study investigated the longitudinal relationship of workers' blood lead concentrations and personal hygiene habits from 1991 through 1997.

METHODS

In each of the 7 years of the study, occupational physicians questioned workers regarding nine personal hygiene items, personal information, and medical history before their annual health examination. The relationship between blood lead concentrations and personal hygiene habits was analyzed by longitudinal multiple regression in a mixed effect model with adjustment for potential confounders. In addition, the risk ratio of a blood lead concentration exceeding 40 micrograms/dL in men and 30 micrograms/dL in women (the action levels set by the Department of Health, Taiwan) was estimated by generalized estimating equations.

RESULTS

Blood lead levels decreased significantly in the first 5 years of the study. The personal habits most closely related to blood lead concentrations were smoking at work sites (estimated coefficient = 3.13, P < 0.001), and eating at work sites (estimated coefficient = 1.38, P = 0.069). The risk ratio for workers with both these habits exceeding the action level of blood lead was 2.93 (95% CI 1.27-6.77). Difference in job titles, however, accounted for a major portion of the variance in blood lead. For example, working in "pasting" and "plate-cutting" was associated with blood lead elevations > 20 micrograms/dL in comparison to the "low- or no-exposure jobs."

CONCLUSIONS

Health promotion programs can decrease exposure of lead workers; reducing the practices of smoking and eating at work sites should be the core of such programs. However, a major reduction in lead exposure for some jobs (e.g., "pasting" and "plate cutting") in lead battery factories in Taiwan is unlikely to occur without major engineering changes.

Pregnane glycosides, gymnepregosides G-Q from the roots of Gymnema alternifolium

The structural elucidation of eleven new related polyoxypregnane glycosides, gymnepregosides G (1), H (2), I (3), J (4), K (5), L (6), M (7), N (8), O (9), P (10) and Q (11), from the roots of Gymnema alternifolium (Asclepiadaceae) was achieved by a detailed study of 1H- and 13C-NMR spectral data and chemical means. The results obtained for new compounds, 1-11, show that they are (20S)-pregn-6-ene-3 beta,5 alpha,8 beta,12 beta,14 beta,17 beta,20-heptaol 3-O-glycosides, and all the sugars at C-3 are beta(i-->4)-linked. Some of them possess benzoyl, (E)- and (Z)-cin-namoyl, and tigloyl residues as the ester linkages located at C-12 and/or C-20 of the aglycone.

Plasma p53 protein and anti-p53 antibody expression in vinyl chloride monomer workers in Taiwan

Vinyl chloride (VC) workers are known to be at risk for development of angiosarcoma of the liver (ASL), a rare tumor. Previously, a study of p53 gene mutations in tumors of VC-exposed workers found that 50% of liver angiosarcomas contained such mutations. Mutant p53 oncoprotein and anti-p53 antibodies can also be found in the sera of ASL patients and VC-exposed workers without cancer. Workers in Taiwan have also been exposed to VC, and some have contracted liver tumors. In this study, we used enzyme-linked immunosorbent assays to detect mutant p53 protein and anti-p53 antibodies in the plasma of VC-exposed workers in Taiwan. Thirty-three of 251 (13.2%) VC-workers tested positive for the p53 overexpression (10% with positive mutant p53 protein and 3.6% with positive anti-p53) in their plasma, but only 2 of 36 controls (5.6%) tested positive (2.8% with positive mutant p53 protein and 2.8% with positive anti-p53). There was a significant association between cumulative VC exposure concentration and positive p53 expression (P = 0.032) among VC workers after we adjusted for age, hepatitis, drinking, and smoking status. In summary, P53 overexpression (mutant p53 protein or anti-p53 antibody) can be found in the plasma of VC workers in Taiwan, and a significant dose-response relationship exists between plasma p53 overexpression and VC cumulative exposure concentration.