A case of Collet-Sicard syndrome associated with traumatic atlas fractures and congenital basilar invagination

An 18 year old man with congenital basilar invagination developed multiple lower cranial nerve (CN) palsies including CN IX to XII after a traffic accident. Computed tomography of his skull base revealed a two part atlas Jefferson fracture. Normally, lower cranial nerves (CN IX-XII) pass through a space between the styloid process and the atlas transverse process. Atlas burst fractures rarely cause neurological deficits because of a greater transverse and sagittal diameter of the spinal canal at the atlas, and a tendency of the lateral masses to slide away from the cord after injury. However, when associated with a rare condition-congenital basilar invagination-atlas fractures can compromise the space and make CN IX-XII more vulnerable to compression injury. This report discusses the correlation between the anatomical lesions and clinical features of this patient.

Primary intracranial myxopapillary ependymomas: report of two cases and review of the literature

Myxopapillary ependymoma is a variant of ependymoma occurring almost exclusively in the conus medullaris or filum terminale. Myxopapillary ependymoma found primarily in the brain is extremely rare. Two such cases appearing at the 4th ventricle and cerebral falx are reported. The imaging features of such tumors are a primary cystic mass with strong enhancement at its solid part. Myxopapillary ependymoma should be a possible differential diagnosis when an intracranial cystic tumor is found.

A scoring system for the early detection of oral submucous fibrosis based on a self-administered questionnaire

OBJECTIVES

The aims of the present study were to evaluate the frequent clinical complaints of oral submucous fibrosis (OSF) and to develop a scoring system for early detection of the disease by a self-administered questionnaire.

METHODS

A total of 296 subjects were recruited, including 123 OSF patients without oral cancer and 173 betel quid chewers without OSF or oral cancer. A self-administered questionnaire was used to collect the symptom profile from study subjects. Their maximal mouth opening (MMO) between upper and lower incisor edges was measured and recorded by well-trained nurses. A binary logistic regression model examining the likelihood of OSF based on the eight symptoms of interest was used to develop the scoring system.

RESULTS

Among 79 OSF subjects with an MMO < 35 mm, the most frequent complaint was trismus (87.3%), followed by burning sensation (76.0%) and xerostomia (72.2%). Among 44 OSF subjects with an MMO > or = 35 mm, burning sensation (68.2%) was the most frequent complaint, followed by trismus (54.5%) and xerostomia (54.5%). Six frequent complaints including trismus, burning sensation, xerostomia, sore throat, numbness, and oral ulceration were utilized to develop a scoring system for the early detection of OSF. The scoring system had an area under the receiver operating characteristic curve of 0.90.

CONCLUSION

This study suggests a screening questionnaire of frequent complaints for the early detection of OSF.

Modification effects of GSTM1, GSTT1 and CYP2E1 polymorphisms on associations between raw salted food and incomplete intestinal metaplasia in a high-risk area of stomach cancer

Incomplete intestinal metaplasia (IM) is a precursor of stomach cancer. To identify risk factors of incomplete IM, a 2-stage survey was carried out in 1995 among 1,485 residents in Matzu, an area with highest mortality from stomach cancer in Taiwan. There were 312 study subjects including 174 men and 138 women sampled for the gastroendoscopic examination of IM. Information on personal and familial history of stomach cancer, cigarette smoking, alcohol consumption and intake frequency of various salted food items were obtained by personal interview based on a structured questionnaire. Blood samples were collected from each participant. Four biopsies per subject were taken from all subjects at gastroendoscopic examination to diagnose the status of IM pathologically. The Helicobacter pylori in biopsies was detected by the histomorphological or immunochemistry method, and antibodies against H. pylori in serum by the enzyme-linked immunosorbent assay. Plasma level of selenium was determined by atomic absorption spectrometry, plasma level of retinol, alpha-tocopherol, alpha-carotene, and beta-carotene by high performance liquid chromatography, genotypes of glutathione S-transferase (GST) M1 and T1 and cytochrome P450 (CYP) 2E1 by polymerase chain reaction. The significant association between history of stomach cancer among first-degree relatives and incomplete IM was found (odds ratio [OR] = 2.50; 95% confidence interval [CI] = 1.15-5.43). There was no association between H. pylori infection and incomplete IM. Alcohol drinkers for >20 years had an elevated risk compared to non-drinkers (OR = 3.34; 95% CI = 1.19-9.39). No associations between incomplete IM and plasma levels of selenium, retinol, alpha-tocopherol, alpha-carotene and beta-carotene were found. Salted food including salted meat, dehydrated salted vegetables and raw salted seafood consumed at ages of </=15 and 16-30 years old was associated with an increased IM risk with OR ranging from 2-3. More striking associations between incomplete IM and salted food intake were observed among subjects with genotypes of GSTM1 null, GSTT1 non-null and CYP2E1 c1/c1. Our study suggests the importance of gene-environment interaction on the development of incomplete IM.

The use of evoked potentials for clinical correlation and surgical outcome in cervical spondylotic myelopathy with intramedullary high signal intensity on MRI

OBJECTIVE

To investigate the use of motor evoked potentials (MEPs) and somatosensory evoked potentials (SEPs) for clinical significance and surgical outcome in patients with cervical spondylotic myelopathy (CSM) with intramedullary high signal intensity on T2 weighted MRI.

METHODS

Forty nine patients were scored according to the modified Japanese Orthopaedic Association (JOA) score for cervical myelopathy. MEP and SEP studies were performed and the results were categorised as normal or abnormal. Thirty nine patients who had received surgical decompression were re-evaluated after 6 months. Surgical outcome was represented by the recovery ratio of the JOA score.

RESULTS

Abnormal MEPs were observed in 44 patients (arm: 43; leg: 30). Abnormal SEPs were found in 32 patients: (median: 24; tibial: 23). Patients with abnormal SEPs had a worse JOA score than those with normal SEPs. Thirty nine patients received surgical treatment. Patients younger than 55 had better recovery ratios than those who were 55 or older (p = 0.005, two sample Student's t test). Patients with normal median SEPs also had better recovery ratios than those with abnormal median SEPs (p = 0.007, two sample Student's t test). Among median SEP variables, only N9-20 was significantly associated with recovery ratio (p = 0.016, stepwise linear regression), with age factor controlled (p = 0.025, stepwise linear regression).

CONCLUSION

Arm MEP was the most sensitive EP test for detecting myelopathy in patients with chronic CSM. Median and tibial SEPs correlated well with the severity of myelopathy while normal median SEPs correlated with good surgical outcome. Among median SEP variables, only N9-20 correlated with surgical outcome.

Increased Circulating Endothelin-1 in Rheumatic Mitral Stenosis

BACKGROUND

Increased plasma endothelin (ET)-1 concentrations have been observed in patients with rheumatic mitral stenosis (MS). However, the mechanisms of increased circulating ET-1 in patients with MS remain unclear.

METHODS

We measured plasma concentrations of ET-1 in blood samples from the femoral vein and artery, and right and left atria obtained from 20 patients with moderate-to-severe rheumatic MS before and after percutaneous transluminal mitral valvuloplasty (PTMV) [group 1; 16 patients in chronic atrial fibrillation and 4 patients in sinus rhythm]. In addition, we measured plasma concentrations of ET-1 in the peripheral venous blood samples obtained from 22 control patients (including 14 healthy volunteers in sinus rhythm [group 2] and 8 patients in chronic lone atrial fibrillation [group 3]). Plasma ET-1 concentrations were measured by solid-phase, sandwich enzyme-linked immunosorbent assay.

RESULTS

The peripheral venous plasma concentrations of ET-1 were significantly higher in group 1 patients (2.46 +/- 0.90 pg/mL) than in group 2 and group 3 patients (0.74 +/- 0.42 pg/mL and 0.99 +/- 0.41 pg/mL, respectively [mean +/- SD]; p < 0.0001). However, there was no significant difference in the peripheral venous concentrations of ET-1 between group 2 and group 3 patients. In group 1 patients, the plasma ET-1 concentration in the femoral vein (2.46 +/- 0.90 pg/mL) was significantly higher than that in the right atrium (2.02 +/- 0.69 pg/mL), left atrium (2.11 +/- 0.99 pg/mL), and femoral artery (2.05 +/- 0.75 pg/mL) [p = 0.0001]. The plasma ET-1 concentration in the femoral vein was not correlated with the mean left atrial pressure (r = 0.05; p = 0.838) and mean pulmonary artery pressure (r = 0.07; p = 0.757). The plasma ET-1 concentration in the left atrium was also not correlated with the mean left atrial pressure (r = 0.11; p = 0.656), mean pulmonary artery pressure (r = 0.06; p = 0.788), or mitral valve area (r = 0.02; p = 0.936). Although the area of mitral valve increased significantly (1.06 +/- 0.17 cm(2) vs 1.48 +/- 0.32 cm(2); p < 0.0001), and the mean left atrial pressure (23.0 +/- 5.1 mm Hg vs 17.6 +/- 5.9 mm Hg; p < 0.0001) and mean pulmonary arterial pressure (31.0 +/- 7.9 mm Hg vs 25.5 +/- 7.0 mm Hg; p < 0.001) fell significantly and immediately after PTMV, there were no significant changes in the plasma ET-1 concentrations in the femoral vein, right atrium, left atrium, and femoral artery immediately after PTMV.

CONCLUSION

Increased production of ET-1 in the pulmonary circulation in response to increased pulmonary artery pressure was not the mechanism of increased circulating ET-1 concentration in patients with MS. We proposed that one of the mechanisms of increased ET-1 concentration in the femoral vein was increased peripheral ET-1 release due to increased systemic venous pressure and mechanical damage of the endothelium.

Prevalence of myopia in Taiwanese schoolchildren: 1983 to 2000

INTRODUCTION

To determine time trends in myopia over a 20-year period in Taiwan, we conducted 5 nationwide surveys pertaining to the ocular refraction of schoolchildren in 1983, 1986, 1990, 1995 and 2000.

MATERIALS AND METHODS

The sampling technique used herein involved the assessment of stratified systematic clusters, with the unweighted myopic rate being represented using data derived from different sectors of the population, such as metropolitan, city, town, and aboriginal. The mean values for the spherical equivalent of the cycloplegic refractive status and the dimension of corneal radii as determined by the autorefractometer were used for the calculation.

RESULTS

In our review of 5 nationwide myopia surveys, we found that the mean prevalence of myopia among 7 year olds increased from 5.8% in 1983 to 21% in 2000. At the age of 12, the prevalence of myopia was 36.7% in 1983 increasing to 61% in 2000, corresponding figures for 15-year-olds being 64.2% and 81%, respectively. The prevalence of myopia increased from 74% in 1983 to 84% in 2000 for children aged between 16 and 18 years, and, in addition, the prevalence of high myopia (over -6.0 D) increased from 10.9% in 1983 to 21% of 18-year-old students of Taiwan in 2000. The mean refractive status at the age of 12 deteriorated from -0.48 D in 1983 to -1.45 D in 2000, and from -1.49 D to -2.89 D for children aged 15, whilst for individuals aged 18, it deteriorated from -2.55 D in 1983 to -3.64 D in 2000. The mean ocular refraction began to progress to a myopic condition at the age of 11 in 1983, this becoming an age of 8 years in 2000. There appeared to be significant difference in both the prevalence and the degree of myopia between study participants residing in cities and villages.

CONCLUSIONS

We conclude that the cause of the relative increasing severity of myopia among the schoolchildren was due to the onset of myopia at a very young, and progressively-decreasing, age over the study period. Thus, to reduce the prevalence and severity of myopia, we should pay more attention to the eye care of pre-schoolchildren.

Six-month angiographic results of primary angioplasty with adjunctive PercuSurge GuardWire device support: Evaluation of the restenotic rate of the target lesion and the fate of the distal balloon occlusion site

Recently, the combination of primary percutaneous coronary intervention (PCI) and adjunctive PercuSurge device support has been reported to be superior to conventional primary PCI in terms of immediate angiographic results. However, there are no data regarding 6-month angiographic results for either the treatment site or the site of the distal protection balloon. The purpose of this study was to address these two issues. Between May and November 2002, a total of 74 patients who had experienced acute myocardial infarction (AMI) underwent either primary PCI (48 patients within 12 hr of AMI) or elective PCI (26 patients with AMI of > 12 hr and < 72 hr) using the PercuSurge device through a transradial approach. The final TIMI 3 flow and myocardial blush grade > or = 2 achieved were 94% and 93%, respectively. Of these patients, three died in the hospital, two died in the third month after discharge, and the remainder of the patients were followed up in our outpatient department for a mean of 13 +/- 2.9 months. Six-month angiographic follow-up was performed in 85.5% (59/69) of patients. The angiographic restenotic rate (defined as > or = 50% restenosis at the target lesion site) was 22.0% (13/59) of patients. However, only 11.9% (7/59) of patients required repeat target vessel revascularization. Moderate obstruction at the site of the distal protection balloon was found in 5.1% (n = 3) of patients during PCI. Six-month angiographic results demonstrated that all three patients had significant stenosis at the site of the distal protection balloon that required PCI. PercuSurge device utilization during PCI in the clinical setting of AMI yielded a substantially higher rate of immediate final TIMI 3 flow in epicardial vessels and increased the integrity of the microvasculature. Combined therapy of PCI with the PercuSurge device appeared to have favorable late angiographic results at the target site. Late significant stenosis occurred at the site of the distal protection balloon if a preexisting moderate or more advanced atherosclerotic lesion was present there.

Seropositivity of hepatitis B e antigen and hepatocellular carcinoma

Chronic infection with hepatitis B virus (HBV) is an important clinical problem due to its worldwide distribution and potential of adverse sequelae including hepatocellular carcinoma (HCC). Hepatitis B e antigen (HBeAg) is a biomarker of active viral proliferation in hepatocytes and infectivity. The prevalence of HBeAg among subjects chronically infected with HBV decreases with the increase in age. Case series studies have found a lowest seroprevalence of HBeAg in HCC patients compared with patients affected with chronic hepatitis B and liver cirrhosis. Case-control studies have shown a significantly higher seroprevalence of HBeAg in HCC cases than matched controls. A recent long-term follow-up study has shown a significantly elevated HCC risk for seropositives of both hepatitis B surface antigen (HBsAg) and HBeAg compared with seropositives of HBsAg only and seronegatives. The biological gradient remained in further stratification analyses by serum level of alanine transaminase and status of liver cirrhosis detected by ultrasonography. The cumulative HCC risk from age 30 to 70 years has been estimated to be 87% for those who were persistently seropositive on HBsAg and HBeAg, 12% for those with persistent seropositivity of HBsAg only, and 1% for those who were seronegative on HBsAg and HBeAg.

Transradial application of percusurge guardwire device during primary percutaneous intervention of infarct-related artery with high-burden thrombus formation

A large infarct-related artery (IRA), which mostly contains high-burden thrombus formation (HBTF) and lipid pool-like plaque contents, has been suggested to play a pivotal role in the no-reflow phenomenon during primary percutaneous coronary intervention (p-PCI). To reduce the thrombus burden of the IRA using the PercuSurge GuardWire device before intervention may be of crucial importance to preventing no-reflow. The purposes of this study were to test the transradial application (TRA) of this new mechanical device and to determine its impact on prevention of no-reflow during p-PCI. From May to September 2002, the PercuSurge GuardWire device was utilized in 42 consecutive patients with acute myocardial infarction and large IRA (vessel size >or= 3.5 mm with HBTF; group 1). From January to December 2000, p-PCI was performed in large IRA (vessel size >or= 3.5 mm) with HBTF using tranfemoral arterial approach in 101 consecutive patients (group 2). The angiographic and clinical outcomes of the two groups were compared in a chronologically consecutive manner. Successful reperfusion (final TIMI-3 flow) was significantly higher in group 1 than in group 2 patients (95.2% vs. 79.1%; P = 0.005). Moreover, the combined incidence of vascular complications, post-PCI thromboembolisms (defined as a distal embolism and a post-PCI residual thrombus score of >or= 3), and combined 30-day major adverse cardiac events were significantly lower in group 1 than in group 2 patients (all P values < 0.05). In group 1 patients, post-p-PCI myocardial blush (MB) of >or= 2 grades was found to be more than 88.0%. Furthermore, when compared with preintervention, thrombus scores were significantly reduced after aspiration (P = 0.0001), whereas the minimal lumen diameter (P = 0.0001), TIMI flow grade (P = 0.0001), and MB grade (P = 0.0001) had all significantly increased after aspiration using Export Aspiration Catheter. There were no significant differences in corrected TIMI frame count (P = 0.42), TIMI flow grade (P > 0.5), or MB grade (all P values > 0.5) between postaspiration and post-PCI. The TRA of the PercuSurge GuardWire device during primary intervention of large IRA with HBTF was safe and feasible and provided benefits to patients. The initial successful reduction of the thrombus burden with this mechanical device before intervention can be translated into increased final TIMI-3 flow, a combined MB of >or= 2 grades, and fewer final thromboembolic events.

Effect of Adjunctive Tirofiban Therapy on Angiographic and Clinical Outcomes in Patients With ST-segment Elevated Acute Myocardial Infarction Undergoing Primary Stenting

The benefit of primary percutaneous coronary intervention is limited by a 5% to 20% incidence of suboptimal epicardial coronary blood (< or = TIMI-2 flow). Recently, data has demonstrated that when administered in conjunction with primary stenting for the treatment of acute myocardial infarction (AMI), abciximab improves the success rate of the stenting procedure and provides additional clinical benefits. But data on a combination of tirofiban and primary stenting for treatment of ST-segment elevated (ST-se) AMI is unknown. Between May 1999 and September 2000, primary stenting without adjunctive tirofiban therapy was performed in 136 consecutive patients (control group) with ST-se AMI. Between January 2001 and May 2002, we routinely administered tirofiban to 133 consecutive patients (study group) with ST-se AMI before they underwent primary stenting. The angiographic and clinical outcomes of both groups were compared in a chronologically consecutive manner. The overall mortality rate was significantly higher in patients with failed (< or = TIMI-2 flow) than in patients with successful (TIMI-3) reperfusion (20.0% vs 3.5%, P < 0.0001). Univariate analysis demonstrated that there were no significant differences in the successful reperfusion (85.7% vs 84.6%, P = 0.84) or 30-day combined end points - death, recurrent ischemia or reinfarction (8.3% vs 11.0%, P = 0.59) between study and control group patients. Clinical variables were used to statistically analyze potential risk factors for unsuccessful reperfusion (< or = TIMI-2 flow) in the study group patients. Multiple stepwise logistic regression analysis demonstrated that the reference lumen diameter (RLD) of the infarct-related artery (IRA) > or = 3.5 mm (P = 0.0004) and the lesion length of the obstruction > or = 20.0 mm (P = 0.018) were the significant independent predictors of failed normalized coronary blood flow. There were no significant differences in the restenotic rate of IRA (29.2% vs 30.8%, P = 0.9) or mortality rate (1.6% vs 1.6%, P = 1.0) at six-month follow-up. In conclusion, our study demonstrates that primary stenting with adjunctive tirofiban therapy in ST-se AMI did not provide additional benefits in short-term and intermediate-term angiographic and clinical outcomes compared to conventional primary stenting.

Epstein-Barr virus seroreactivity among unaffected individuals within high-risk nasopharyngeal carcinoma families in Taiwan

Most adults have been infected with EBV. Many studies have indicated that antibodies against specific EBV antigens, particularly IgA antibodies, can be predictive or prognostic of EBV-associated malignancies, such as NPC. We hypothesized that healthy individuals from families with a history of multiple members affected with NPC (who therefore might be genetically susceptible to NPC themselves) might have an EBV antibody profile that is distinct from that seen in healthy individuals from the community at large. To explore this possibility and examine determinants of anti-EBV antibody levels in healthy, high-risk individuals, we evaluated data from 2 parallel studies of NPC in Taiwan, which included 1,229 healthy members of families in which 2 or more individuals were affected with NPC and 320 controls from the community at large. Blood collected from participants was tested for IgA antibodies against EBV VCA and EBNA-1 and for neutralizing antibodies against EBV DNase using standard assays. We observed evidence of familial aggregation of EBV seroreactivity among individuals from high-risk, multiplex NPC families. Anti-VCA IgA and anti-EBNA-1 IgA antibody seroprevalence in unaffected family members of NPC cases was 5-6 times higher than in members of the community (p < 0.01). This elevated seroprevalence among unaffected individuals from high-risk families was observed regardless of the relationship of the unaffected individual to the closest affected relative (siblings, parents, children or spouses). No sociodemographic or environmental factors examined were found to strongly and consistently correlate with elevated seroprevalence, but patterns emerged of increasing seroprevalence among older individuals and among females. Unaffected individuals from high-risk NPC families have elevated anti-EBV IgA antibody titers. The etiologic and clinical implications of this finding remain to be established.

Seroepidemiology of hepatitis E virus infection among preschool children in Taiwan

In order to study the seroprevalence of hepatitis E virus (HEV) infection among preschool children in Taiwan, a community-based survey was carried out in 54 kindergartens in 10 urban areas, 10 rural areas, and 2 aboriginal areas randomly selected through stratified sampling. Serum specimens of 2,538 preschool children were screened for HEV antibodies (anti-HEV) by a commercially available enzyme immunoassay. The odd ratios (OR) with 95% confidence intervals (CI) were estimated through multiple logistic regression analysis. A total of 86 children were anti-HEV seropositive, giving a prevalence of 3.4%. The prevalence of anti-HEV was 3.9% (19 of 484) among aboriginal children, a significantly increased seroprevalence compared with that among children who lived in urban areas (OR = 1.68; 95% CI = 1.56-2.95; P < 0.05). Females had a higher anti-HEV seroprevalence than the males (OR = 1.55; 95% CI = 1.14-2.54; P < 0.05). Rates of anti-HEV antibody increased with age in aboriginal areas (chi(2) for trend = 5.59, P = 0.02), but decreased with age in non-aboriginal areas. The poor water supply system, poor sewage disposal, exposure to wild animals, and other environmental conditions in the aboriginal areas might have played a role in their infection with HEV in Taiwan.

Role of reproductive factors in hepatocellular carcinoma: Impact on hepatitis B- and C-related risk

Hepatocellular carcinoma (HCC) is more prevalent in men than in women. Estrogen may play some role in the development of HCC. We conducted a multicenter case-control study to evaluate the effects of reproductive factors on HCC risk, and to assess whether the association between each factor and HCC differs between hepatitis B surface antigen (HBsAg)-positive and -negative women, in which hepatitis C virus (HCV) is the major cause of HCC. The study included 218 women with HCC and 729 control women selected from nonbiological and first-degree female relatives of patients with HCC. The risk of HCC was inversely related to the number of full-term pregnancies (FTP) (P(trend) =.0216) and age at natural menopause (P(trend) =.0251 among women aged 45-55 without prior surgical menopause). Oophorectomy at age <or=50 during premenopausal years was also a risk factor (multivariate-adjusted OR, 2.57; 95% CI, 1.42-4.63). Use of hormone replacement therapy (HRT) (multivariate-adjusted OR, 0.46; 95% CI, 0.27-0.79) was associated with a lower risk of HCC, and there was a trend in the risk with increasing duration of HRT (P(trend) = 0.0013). All reproductive factors had a similar impact on HBsAg-positive and -negative women except for an early menarche (<or=12 vs. >or=16 years), which increased HCC risk in HBsAg carriers (multivariate-adjusted OR, 6.96; 95% CI, 2.52-19.18) but posed no increased risk in noncarriers (P(interaction) =.0053). In conclusion, increased exposure to estrogen during adulthood may provide a protective effect against HCC. Nevertheless, an early menarche, which results in early estrogen exposure, does not confer protection for HBsAg carriers.

Effect of the PercuSurge GuardWire device on the integrity of microvasculature and clinical outcomes during primary transradial coronary intervention in acute myocardial infarction

The present study investigates whether preintervention thrombectomy with a PercuSurge distal balloon protection device can improve final angiographic results compared with adjunctive tirofiban therapy during primary percutaneous coronary intervention (PCI) in large infarct-related arteries (IRAs) (vessel size >/=3.5 mm) with high-burden thrombus formation (HBTF). Results indicate that this mechanical device is superior to adjunctive tirofiban therapy during primary PCI in large IRAs with HBTF in terms of final epicardial flow, microvasculature integrity, and 30-day clinical outcomes.

Direct stenting of a transradial left internal mammary artery graft

Taking the transfemoral approach when performing a left internal mammary artery (LIMA) graft intervention is generally recognized as posing significant technical challenges. However, little has been reported on alternative transradial approaches to LIMA. In this report, we present our experience in a patient who had anastomosis-site LIMA graft stenosis and was successfully treated with direct stenting. We used a 6-French Kimny guiding catheter inserted through the left radial artery, even though the procedure was complicated by an acute occlusion of a LIMA body, requiring bail-out stenting following intra-aortic balloon pump support and temporary cardiac pacing. The patient was discharged 6 days after the procedure and remains asymptomatic during follow-up visits. Our results suggest that a transradial approach is feasible for LIMA intervention procedures.

Peripheral differential leukocyte counts and subsequent mortality from all diseases, cancers, and cardiovascular diseases in Taiwanese

BACKGROUND AND PURPOSE

A higher total leukocyte count has been reported to predict all-cause mortality in men, but data are limited for this relation in women and for the relation between differential leukocyte counts and all-cause mortality in both men and women. This study was designed to analyze these relationships in Taiwanese.

METHODS

A total of 8447 subjects were enrolled from participants in a physical check-up program at National Taiwan University Hospital from 1995 to 1997. Information on mortality was obtained from a national mortality databank that was updated to the end of 2001. Data were analyzed by Student's t test and Cox regression analysis.

RESULTS

Among the 245 deaths, 88 were due to cancer and 62 were due to cardiovascular diseases. Cox regression analysis revealed an inverse association between lymphocyte count and all-cause mortality in the study group as a whole (all subjects, p < 0.01, hazard ratio = 0.73). This inverse association was mainly due to an inverse association between lymphocyte count and cancer mortality (p < 0.05, hazard ratio = 0.64), especially the mortality from hepatoma (p = 0.010, hazard ratio = 0.29). The latter hazard ratio of 0.29 indicates that, in all subjects, every decrease of 1.0 x 10(9)/L in lymphocyte count increased the risk of mortality from hepatoma by 3.45-fold during an average follow-up period of 65.5 months. There was a positive association between total leukocyte count and all-cause mortality in men (p < 0.05, hazard ratio = 1.10), mainly due to both the neutrophil and monocyte counts having positive associations with the cardiovascular mortality (both p < 0.05, hazard ratio = 1.23 and 1.22, respectively). The latter hazard ratio of 1.22 indicates that, in men, every increase of 0.1 x 10(9)/L in monocyte count increased the risk of cardiovascular mortality by 1.22-fold.

CONCLUSIONS

In Taiwanese adults of both genders, a lower lymphocyte count is associated with cancer mortality, especially mortality from hepatoma. In Taiwanese men, higher neutrophil and monocyte counts are associated with cardiovascular mortality.

The methylenetetrahydrofolate reductase 677C-->T polymorphism and lung cancer risk in a Chinese population

BACKGROUND

We examined the relationship of the MTHFR C677T genotype with the risk of lung cancer in a nested case-control study conducted in a cancer screening follow-up study in Taiwan.

MATERIALS AND METHODS

A total of 59 histologically confirmed lung cancer cases and 232 cancer-free controls were recruited between July 1990 and December 2000. The MTHFR C677T genotype was determined by a PCR-restriction fragment length polymorphism assay.

RESULTS

The MTHFR 677T variant genotype, including 677CT and 677TT, was observed in 39% of cases and 47% of controls. The resultant adjusted odds ratio (OR) was 0.71 (95% confidence interval [CI] = 0.39-1.30). The inverse association of the MTHFR 677T variant genotype with lung cancer risk was apparent in both smokers and nonsmokers.

CONCLUSION

These results suggest that the MTHFR 677T variant genotype reduces the risk of lung cancer. Larger studies incorporating dietary folate intake and the variant genotypes are needed to clarify our results.

Polymorphisms in XRCC1 and glutathione S-transferase genes and hepatitis B-related hepatocellular carcinoma

Chronic infection with hepatitis B virus (HBV) causes DNA damage. An arginine (Arg)-to-glutamine (Gln) polymorphism at codon 399 in the XRCC1 gene is putatively associated with DNA damage. In a case-control study of 577 HBV surface antigen carriers with hepatocellular carcinoma (HCC) and 389 HBV carrier control subjects, we investigated the association between this polymorphism and the risk of HCC and assessed whether this association varied with glutathione S-transferase (GST) status; GSTs are involved in carcinogen metabolism. All statistical tests were two-sided. The XRCC1 Gln allele was associated with a dose-dependent increased risk of early-onset HCC (<50 years) but not with the risk of late-onset HCC (P(trend) =.01). The GSTT1-null genotype alone did not affect risk, but the GSTM1-null genotype was associated with a decreased risk for early-onset HCC. Various combinations of GSTM1 and GSTT1 genotypes differentially modified the association of XRCC1 with HCC (P(interaction) =.005); e.g., for individuals with the GSTT1-null/GSTM1-present genotype, the risk of HCC was greater for those with the Gln/Gln genotype (odds ratio = 8.07, 95% confidence interval = 1.67 to 38.93) than for those with the Arg/Arg genotype. Thus, GST status appears to affect the risk of HCC associated with this XRCC1 polymorphism.

Nasopharyngeal carcinoma and genetic polymorphisms of DNA repair enzymes XRCC1 and hOGG1

Nitrosamine consumption and polymorphisms in CYP2E1, the product of which is involved in the activation of nitrosamines into reactive intermediates, have been shown to be associated with nasopharyngeal carcinoma (NPC) risk. Given that reactive intermediates created during nitrosamine metabolism are capable of DNA damage, we further hypothesized that differences between individuals in their ability to repair DNA damage might be important in NPC pathogenesis. To evaluate this hypothesis, this study focused on effects of genetic polymorphisms of DNA repair genes hOGG1 and XRCC1 on the development of NPC. We conducted a case-control study to investigate the genotypes of 334 patients with NPC and 283 healthy community controls matched by sex, age, and residence. The PCR-based RFLP assay was used to identify genetic polymorphisms. After adjustment for sex, age, and ethnicity, the odds ratio (OR) of developing NPC for hOGG1 codon 326 genotypes of Ser/Cys and Cys/Cys compared with the Ser/Ser genotype was 1.6 (95% CI, 1.0-2.6). For XRCC1 codon 280 genotypes of Arg/His and His/His compared with the Arg/Arg genotype, the OR was 0.64 (95% CI, 0.43-0.96). Among subjects with putative high-risk genotypes for both hOGG1 and XRCC1, the OR was 3.0 (95% CI, 1.0-8.8). Furthermore, subjects with putative high-risk genotypes for hOGG1, XRCC1, and CYP2E1 had an OR of disease of 25 (95% CI, 3.5-177). Polymorphisms of the DNA repair genes hOGG1 (codon 326) and XRCC1 (codon 280) are associated with an altered risk of NPC. Carriers of multiple putative high-risk genotypes have the highest risk of developing NPC.

Predictors of whole-body vibration levels among urban taxi drivers

To identify a set of important WBV predictors that could be used to develop a statistical instrument for exposure assessment in a large epidemiologic study, a total of 432 WBV measures were taken from a sample of 247 male drivers in Taipei City, Taiwan. In accordance with the ISO 2631-1 (1997) methods, we measured the frequency-weighted vertical acceleration (z-axis) over drivers' seat surface, under conditions representing different types of rides (vacant vs. short vs. long) assigned to random destinations. Mixed effect models were used to analyse the WBV data including repeated measures. For this group of urban taxi drivers regularly exposed to WBV of low intensity (mean = 0.31 ms( - 2), ranging from 0.17 to 0.55 ms( - 2) r.m.s.), our analyses indicated that average driving speed was the primary predictor (p < 0.0001). As average driving speed increased, measured vertical acceleration increased in a quadratic-linear manner (p < 0.0001). Other WBV predictors, after adjusting for the effects of other covariates, included automobile manufacturer (p = 0.02), engine size (p = 0.04), body weight (p = 0.002), age (p = 0.02), use of seat cushion (p = 0.03), and traffic period (p = 0.02). Our study suggests that a similar statistical approach could be employed in future studies to improve the quality and efficiency of WBV exposure assessment in professional drivers.

Gene expression of inflammatory molecules in circulating lymphocytes from arsenic-exposed human subjects

Long-term arsenic exposure is associated with an increased risk of vascular diseases including ischemic heart disease, cerebrovascular disease, and carotid atherosclerosis. The pathogenic mechanisms of arsenic atherogenicity are not completely clear. A fundamental role for inflammation in atherosclerosis and its complications has become appreciated recently. To investigate molecular targets of inflammatory pathway possibly involved in arsenic-associated atherosclerosis, we conducted an exploratory study using cDNA microarray and enzyme-linked immunosorbent assay to identify genes with differential expression in arsenic-exposed yet apparently healthy individuals. As an initial experiment, array hybridization was performed with mRNA isolated from activated lymphocytes of 24 study subjects with low (0-4.32 microg/L), intermediate (4.64-9.00 microg/L), and high (9.60-46.5 microg/L) levels of blood arsenic, with each group comprising eight age-, sex-, and smoking frequency-matched individuals. A total of 708 transcripts of known human genes were analyzed, and 62 transcripts (8.8%) showed significant differences in the intermediate or high-arsenic groups compared with the low-level arsenic group. Among the significantly altered genes, several cytokines and growth factors involving inflammation, including interleukin-1 beta, interleukin-6, chemokine C-C motif ligand 2/monocyte chemotactic protein-1 (CCL2/MCP1), chemokine C-X-C motif ligand 1/growth-related oncogene alpha, chemokine C-X-C motif ligand 2/growth-related oncogene beta, CD14 antigen, and matrix metalloproteinase 1 (interstitial collagenase) were upregulated in persons with increased arsenic exposure. Multivariate analyses on 64 study subjects of varying arsenic exposure levels showed that the association of CCL2/MCP1 plasma protein level with blood arsenic remained significant after adjustment for other risk factors of cardiovascular diseases. The results of this gene expression study indicate that the expression of inflammatory molecules may be increased in human subjects after prolonged exposure to arsenic, which might be a contributory factor to the high risk of atherosclerosis in arseniasis-endemic areas in Taiwan. Further multidisciplinary studies, including molecular epidemiologic investigations, are needed to elucidate the role of arsenic-associated inflammation in the development of atherosclerosis and subsequent cardiovascular disease.