How deep a superficial gravity abscess?
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Adult↗
Biomedical subjects
S-C Chen
Publications and source records attributed to S-C Chen.
Lactococcus garvieae infections in humans: possible association with aquaculture outbreaks.
Lactococcus garvieae is an important pathogen in aquaculture, outbreaks of which significantly affect production. It is a rare pathogen with a low virulence in human infection. The relation between the aquaculture outbreak and the human infection has not been clarified. Prospective and retrospective epidemiologic surveillance of the four patients with L. garvieae infection between 2000 and 2003 and their relations to the aquaculture outbreaks of L. garvieae were conducted. All the four patients with L. garvieae infection were associated with gastrointestinal disorders. Three of the four patients gave a history of consuming raw fish and in three of the four patients, the infection occurred in summer between June and August while there is a decrease of fisheries production and an increase in L. garvieae infection in aquaculture farms. There was a 100% identity of 16S rDNA sequence of L. garvieae isolates from patient 1 and from the squid muscle obtained from the restaurant where patient 1 consumed the raw fish. Sporadic occurrence of L. garvieae infection in human appears to correlate with the seasonal aquaculture outbreaks of L. garvieae infection. The presence of gastro-intestinal disorder may facilitate L. garvieae infection.
Aged↗
Survival benefit of transcatheter arterial chemoembolization in patients with hepatocellular carcinoma larger than 10 cm in diameter.
BACKGROUND: The safety and survival benefit of transcatheter arterial chemoembolization for patients with huge hepatocellular carcinoma is uncertain. AIM: To evaluate the role of embolization in unresectable hepatocellular carcinomas larger than 10 cm. METHODS: Twenty-six consecutive patients who had an unresectable hepatocellular carcinoma larger than 10 cm and refused aggressive treatment, were enrolled as the control group. Another 31 patients matching with the control cases and undergoing embolization for huge unresectable hepatocellular carcinoma served as the embolization group. Survival between the two groups was compared. RESULTS: Two patients (7%) died from embolization-related complications. Patients in embolization group had longer survival than those in control group (median survival: 9.13 vs. 2.1 months). The 1-, 3- and 5-year survival rates in embolization group were 42%, 13% and 7% respectively. The 1- and 3-year survival rates for patients in control group were 8% and 0% respectively. In multivariate analysis, embolization and prothrombin ratio < or =1.2 were two independent factors associated with a better survival. CONCLUSIONS: Embolization-related mortality is low for huge hepatocellular carcinoma, and the technique provides survival benefit in patients with unresectable hepatocellular carcinomas larger than 10 cm in diameter.
Adult↗
Attitude toward living donor liver transplantation in Taiwan.
OBJECTIVES: The purpose of this study was to investigate the attitudes and characteristics of donors for living donor liver transplantation (LDLT). METHODS: This retrospective study was performed by a mailing or by telephone using a questionnaire. LDLT donors were recruited from a teaching hospitals located in a metropolitan area of northern Taiwan. The 11-item attitude questionnaire was specifically developed from the literature review with coordinator, physician, and donor feedback. Donors were asked to rate the queries on a 5-point Likert intensity scale. RESULTS: The 47 LDLT donors included 28 (60%) women and 19 (40%) men. Most of the LDLT donors were aged less than 30 years old (n = 24, 51%) with (n = 12, 26%) between 31 and 40 years, and 11 (23%) more than 41 years. Self-perceived health status was poor (n = 4, 9%), not bad (n = 22, 47%), good (n = 19, 40%), or very good (n = 2, 4%). The top five LDLT donor attitudes were recognition of liver donation (n = 42, 89%), recognition of brain donation (n = 41, 88%), a hero (n = 35, 75%), honor to be a donor (n = 35, 5%), and improved relationship with recipient after donation (n = 33, 70%). The best person to suggest organ donation to a family was ranked as the doctors related to transplantation (n = 41, 88%), transplantation nurse coordinator (n = 40, 85%), social worker (n = 23, 49%), and doctor unrelated to transplantation (n = 17, 17%). CONCLUSION: This study revealed positive attitudes toward donation. Some data afford insight to the decision-making procedure. Donor concerns may help professionals provide better interventions in the future.
Adult↗
Impact of liver donation on quality of life and physical and psychological distress.
UNLABELLED: Our objectives were to assess the characteristics of donors for living-donor liver transplantation (LDLT) and to examine the impact of donation on LDLT donor quality of life (QOL) regarding physical and psychological distress. METHODS: Data were collected from a mailed survey or an interview using a cross-sectional prospective study design. We used the abbreviated version of the World Health Organization Quality of Life (WHOQOL-BREF), Physical Symptom Disturbance Scale, and Psychological Distress Scale. LDLT donors were recruited from a teaching hospital located in a metropolitan area of northern Taiwan. RESULTS: The 35 LDLT donors have a mean age 34.0 +/- 8.6 years and were recruited at a median of 25.9 months after donation (range, 0.6-92 months). The average scores in the four domains of the WHOQOL-BREF scale ranged from 13.5 to 14.9. LDLT Donors reported higher QOL scores in social and environment domains but lower scores in physical and psychological domains than healthy adults. Numbers of physical symptoms experienced by each donor ranged from one (n = 4) to 27 (n = 2). Feeling throbbing, itching or numbness around the wound was the most common physical symptom disturbance reported by donors (n = 26, 74%). Approximately 40% of the donors reported having one to three metrics of psychological distresses. "Easily feel distress and angry" was the most common psychological distress reported by 57% (n = 20) of donors. CONCLUSIONS: This study indicated that liver donation had a mild negative impact on donors physical and psychological facets of QOL. These results may assist professionals to provide appropriate clinical management.
Adult↗
In situ hybridization and RT-PCR detection of Macrobrachium rosenbergii nodavirus in giant freshwater prawn, Macrobrachium rosenbergii (de Man), in Taiwan.
Between January and March 2006, suspected outbreaks of white tail disease were observed in post-larvae and juveniles of Macrobrachium rosenbergii in hatcheries and nursery ponds at Kaohsiung and Pingtung Counties in southern Taiwan. Pathognomonic lesions showed the presence of large oval and/or irregular basophilic, cytoplasmic inclusion bodies in the infected muscles and hepatopancreas. Reverse transcriptase polymerase chain reaction (RT-PCR) assay and in situ hybridization (ISH) revealed evidence of M. rosenbergii nodavirus (MrNV) infection but did not detect extra small virus. Phylogenetic analysis indicated that there were very high identities between nucleotide sequences among six strains obtained in this study (99.5-100%), moderate identities with Caribbean and Indian strains (98.2-98.6%), but slightly lower identity with a Chinese strain (95.2%). This is the first confirmation of MrNV in giant freshwater prawns, using an RT-PCR and ISH, in Taiwan.
Abdominal Muscles↗
Viral hepatitis and proteinuria in an area endemic for hepatitis B and C infections: another chain of link?
BACKGROUND AND OBJECTIVES: Virus hepatitis may lead to nephropathy as one of its multiple extrahepatic manifestations. Proteinuria by dipstick, a simple test in practice, is a useful and cardinal sign of underlying renal abnormalities. The aim of this study was to elucidate the impact of hepatitis B virus (HBV) and/or hepatitis C virus (HCV) infections on the occurrence of proteinuria amongst adults. DESIGN AND SETTING: A prospective, cross-sectional, community-based study was conducted in an HBV/HCV endemic area of southern Taiwan. Eligible subjects aged 40-65 years (n=9934) underwent testing of hepatitis B surface antigen (HBsAg), HCV antibody (anti-HCV) and other related biochemical profiles. Urinalysis with repeated dipstick for proteinuria detection was performed. RESULTS: Anti-HCV-positive rate amongst proteinuria subjects was significantly higher than nonproteinuria subjects (9.6% vs. 6.2%, P<0.001). By contrast, HBsAg-positive rate did not differ between subjects with and without proteinuria (13.0% vs. 13.8%, P=0.57). Prevalence of proteinuria amongst anti-HCV-positive subjects (10.2%) was significantly higher than that in HBsAg-positive subjects (6.4%, P=0.004) and in HBsAg-negative or anti-HCV-negative subjects (7.0%, P=0.004). The difference persisted even after excluding diabetics. Multivariate logistic regression analyses showed that diabetes was the most important significant factor associated with proteinuria, followed by hypertension, anti-HCV seropositivity, body mass index, age and triglyceride levels. CONCLUSION: We demonstrated the significant association between proteinuria and HCV, but not HBV, infection in this HBV/HCV-endemic area.
Adult↗
The role of thyroid autoantibodies in the development of thyroid dysfunction in Taiwanese chronic hepatitis C patients with interferon-alpha and ribavirin combination therapy.
To investigate the role of thyroid autoantibodies in the development of thyroid dysfunction among chronic hepatitis C (CHC) patients receiving interferon-alpha (IFN-alpha) plus ribavirin (RBV) combination therapy, 95 Taiwanese naïve patients with baseline euthyroidism were enrolled. They were treated with IFN-alpha2b, 6 million units thrice weekly, plus RBV 1,000-1,200 mg daily for 24 weeks. Thyroid function, anti-thyroglobulin and antiperoxidase autoantibodies were tested at enrollment (M0), at the end-of-treatment (M6) and 6 months after end-of-treatment (M12). The percentages of thyroid autoantibodies were 8.4%, 11.6% and 9.5%, at M0, M6 and M12 respectively. Fourteen (14.7%) patients developed thyroid dysfunction at M6 or M12. Thyroid dysfunction occurred during treatment in five (62.5%) of the eight patients with baseline thyroid autoantibodies, which was significantly higher than nine (10.3%) of 87 patients without baseline thyroid autoantibodies (P = 0.0001). Among 14 patients who developed thyroid dysfunction, four (80.0%) of five patients with baseline thyroid autoantibodies recovered at M12, in contrast to two (25%) of eight without baseline thyroid autoantibodies recovered at M12 (P < 0.05). In conclusion, thyroid autoantibodies, either occurred before or during IFN-alpha plus RBV combination therapy, carry a high prediction of subsequent thyroid dysfunction. There also exists difference in the clinical manifestations of thyroid dysfunction in CHC patients treated with combination therapy.
Adult↗
Associations of tumour necrosis factor alpha promoter polymorphisms at position -308 and -238 with clinical characteristics of chronic hepatitis C.
The aim of this study was to investigate the association between G vs A transitions in the promoter region of the tumour necrosis factor (TNF) alpha at positions -308 (TNF308.2) and -238 (TNF238.2) and clinical features of chronic hepatitis C (CHC). These two promoter TNF-alpha variants were determined in 250 biopsy-proven CHC patients by polymerase chain reaction amplification, followed by the Restriction Fragment Length Polymorphism (RFLP) method. The distribution of -308 and -238 TNF-alpha promoter genotypes were TNF308.1/TNF308.1: 187 (74.8%), TNF308.1/TNF308.2: 57 (22.8%) and TNF308.2/TNF308.2: 6 (2.4%), respectively, and TNF238.1/TNF238.1: 247 (98.8%) and TNF238.1/TNF238.2: 3 (1.2%). The frequencies of the TNF308.2 and TNF238.2 promoter alleles were 13.8% and 0.6%. Increased TNF308.2 allele copy numbers were significantly associated with increased frequency of lower pretreatment hepatitis C virus (HCV) RNA levels (<800 000 IU/mL; P = 0.031) and severe fibrosis stage (F3-F4; P = 0.006) and higher mean fibrosis score (P = 0.007). The higher cytokine production (with one or two TNF308.2 alleles) was correlated significantly with lower pretreatment HCV RNA levels with a lower mean HCV RNA level (P = 0.024) and increased frequency of lower pretreatment HCV RNA levels (<800 000 IU/mL; P = 0.017). Stepwise logistic regression showed that higher fibrosis score and low HCV RNA levels were independently related to the TNF308.2 allele [odds ratio (95% CI): 1.385 (1.127-1.702) and 0.698 (0.488-0.990)]. We conclude that inheritance of the TNF-alpha promoter genotype at the position -308 appears to be associated with variability in severity of fibrosis and viral load in chronic HCV infection.
Adolescent↗
Analysis of the influence of therapy and viral suppression on high-risk sexual behaviour and sexually transmitted infections among patients infected with human immunodeficiency virus in Taiwan.
This study examined the effects of certain characteristics of human immunodeficiency virus (HIV)-infected patients related to the risks of practising unprotected sex (UPS) among 919 HIV-infected patients who attended the sexually transmitted disease (STD) clinic of the Taipei City STD Control Center, Taiwan, during the period January-July 2004. After learning that they were HIV-positive, 517 (56%) subjects had practised UPS, 476 (52%) had a new STD diagnosis, and 106 (12%) had used some form of injected drug. UPS was reported by 76% of homosexual/bisexual males, 19% of heterosexual males and 5% of females, and was reported more often by those individuals with casual sexual partners (p < 0.001). According to multivariate logistic regression analyses, UPS was associated with male-to-male sexual intercourse (OR 2.46; 95% CI 1.26-4.86, p < 0.001), with casual sexual partners (OR 2.82; 95% CI 1.62-4.88, p < 0.001), and with an individual's knowledge of his/her HIV status for > 11 years (OR 2.06; 95% CI 1.02-4.18, p < 0.05). Although using anti-retroviral therapy to prevent sexual transmission of HIV is rational, the avoidance of at-risk sexual behaviour should also be a priority among HIV-seropositive individuals. Ongoing risk-reduction counselling related to HIV transmission is needed to reduce certain sexual behaviours associated with HIV transmission.
Adult↗
Predictive models of control strategies involved in containing indoor airborne infections.
Recently developed control measure modeling approaches for containing airborne infections, including engineering controls with respiratory protection and public health interventions, are readily amenable to an integrated-scale analysis. Here we show that such models can be derived from an integrated-scale analysis generated from three different types of functional relationship: Wells-Riley mathematical model, competing-risks model, and Von Foerster equation, both of the key epidemiological determinants involved and of the functional connections between them. We examine mathematically the impact of engineering control measures such as enhanced air exchange and air filtration rates with personal masking combined with public health interventions such as vaccination, isolation, and contact tracing in containing the spread of indoor airborne infections including influenza, chickenpox, measles, and severe acute respiratory syndrome (SARS). If enhanced engineering controls could reduce the basic reproductive number (R0) below 1.60 for chickenpox and 3 for measles, our simulations show that in such a prepared response with public health interventions would have a high probability of containing the indoor airborne infections. Combinations of engineering control measures and public health interventions could moderately contain influenza strains with an R0 as high as 4. Our analysis indicates that effective isolation of symptomatic patients with low-efficacy contact tracing is sufficient to control a SARS outbreak. We suggest that a valuable added dimension to public health inventions could be provided by systematically quantifying transmissibility and proportion of asymptomatic infection of indoor airborne infection. Practical Implications We have developed a flexible mathematical model that can help determine the best intervention strategies for containing indoor airborne infections. The approach presented here is scalable and can be extended to include additional control efficacies. If a newly emergent airborne infection should appear, the model could be quickly calibrated to data and intervention options at the early stage of the outbreak. Data could be provided from the field to estimate value of R0, the serial interval between cases, the distributions of the latent, incubation, and infectious periods, case fatality rates, and secondary spread within important mixing groups. The combination of enhanced engineering control measures and assigned effective public health interventions would have a high probability for containing airborne infection.
Air Pollution, Indoor↗
Preventable deaths in patients admitted from emergency department.
BACKGROUND: There is limited data about how appropriate medical care is in the emergency department (ED). OBJECTIVES: To investigate the rate and types of preventable deaths among patients with early mortality after emergency admission from the ED. METHODS: We retrospectively reviewed charts of early mortality (defined as mortality which occurred within 24 hours after admission from the ED) over a 3 year period. Those patients with terminal cancer or out of hospital cardiac arrest (OHCA) at presentation were excluded. Two independent assessors reviewed each eligible chart and determined whether early mortality was preventable. Any disagreements were resolved through discussion between the investigators. A mortality event was considered preventable if actions or missed actions were identified that would have prevented the death. The types of preventability were categorised as misdiagnosis, delayed diagnosis, and inappropriate medical management. Interrater reliability in the initial determination was assessed using Cohen kappa statistic. RESULTS: Over a 3 year period, 210 early mortality cases were identified. Excluding patients with terminal cancer or OHCA, the rate of preventable deaths was 25.8% (32/124). The types of preventability were inappropriate medical management (17 patients), delayed diagnosis (eight), and misdiagnosis (seven). There was good agreement between assessors with a Cohen kappa statistic of 0.81. CONCLUSIONS: Preventable deaths in emergency admitted patients with early mortality are not uncommon. Analysis and identification of preventability early mortality by using a chart based method may be used as a quality assurance index in emergency medical care.
Adolescent↗
alpha-fetoprotein response predicts survival benefits of thalidomide in advanced hepatocellular carcinoma.
BACKGROUND: Radiographic measurements do not always reflect the biological response of hepatocellular carcinoma to drug therapy. AIMS: To evaluate the clinical implications of tumour marker (alpha-fetoprotein) response in advanced hepatocellular carcinoma patients with thalidomide treatment. PATIENTS AND METHODS: Forty-two advanced hepatocellular carcinoma patients with baseline alpha-fetoprotein levels above 200 ng/mL and thalidomide therapy were included. Serum alpha-fetoprotein levels were measured every 4 weeks. alpha-fetoprotein response was defined as a 50% or greater reduction of alpha-fetoprotein levels for 4 or more weeks during treatment. Radiographic response was assessed by World Health Organization criteria; survivals were estimated by Kaplan-Meier method and prognostic factors were assessed by Cox's proportional hazard model. RESULTS: With intention-to-treat analysis, radiographic response and alpha-fetoprotein response were obtained in 7% (three of 42, 95% confidence interval: 0-15) and 24% (10 of 42, 95% CI: 10-38) of patients, respectively. All radiographic response was observed in alpha-fetoprotein responders. Multivariate analyses showed alpha-fetoprotein response was independent prognostic factor for both progression-free survival (relative risk = 0.394, 95% CI: 0.189-0.820, P = 0.013) and overall survival (relative risk = 0.241, 95% CI: 0.096-0.606, P =0.003), whereas radiographic response was not. CONCLUSION: alpha-fetoprotein response can more accurately reflect the biological response of advanced hepatocellular carcinoma to thalidomide therapy than radiographic response.
Aged↗
The role of transcatheter arterial embolization for patients with unresectable hepatocellular carcinoma: a nationwide, multicentre study evaluated by cancer stage.
BACKGROUND: Transcatheter arterial embolization is a major palliative treatment for unresectable hepatocellular carcinoma, but the survival benefit of transcatheter arterial embolization is controversial. AIM: To evaluate the role of transcatheter arterial embolization in different stage of unresectable hepatocellular carcinoma and to select patients who can get the best benefit from the treatment. METHODS: From 1991 to 1995, 476 patients who had unresectable hepatocellular carcinoma from four medical centres in Taiwan were enrolled. Among them, 425 underwent transcatheter arterial embolization, and 51 received supportive treatment alone. The survivals between the two groups were compared. RESULTS: Among the 476 patients, transcatheter arterial embolization can significantly prolong survival. The 1-, 2-, and 5-year survival rates for patients who underwent transcatheter arterial embolization were 60.2%, 39.3%, and 11.5%; and the rates for patients who underwent supportive treatment were 37.3%, 17.6%, and 2%, respectively (P = 0.0002). The survival benefit of transcatheter arterial embolization was observed in patients between Cancer and the Liver Italian Program 0 and Cancer and the Liver Italian Program 4. In multivariate analysis, transcatheter arterial embolization, tumour size <5 cm and earlier Cancer and the Liver Italian Program stage were independent factors associated with a better survival. CONCLUSIONS: For patients who fulfilled the criteria of transcatheter arterial embolization, embolization can serve as a primary treatment for patients with unresectable hepatocellular carcinoma. The survival benefit of transcatheter arterial embolization is regardless of tumour stages.
Carcinoma, Hepatocellular↗
Effects of surface electrical stimulation on the muscle-tendon junction of spastic gastrocnemius in stroke patients.
PURPOSE: The purpose of this study was to explore the effects of spasticity suppression by surface electrical stimulation (ES) o the muscle-tendon junction of spastic gastrocnemius muscles in stroke. METHODS: Twenty-four neurologically stable stroke patients (aged 41-69 years, 12-35 months post-stroke), with spasticity graded 2 or 3 on the modified Ashworth scale, were recruited and divided into two groups. In the ES group, each patient received 20 min of surface ES once daily, 6 days per week for 1 month. In the control groups, ES was used with stimulation intensity kept at zero. To evaluate the therapeutic effect, the modified Ashworth scale, Fmax/Mmax ratio, H-reflex latency, H-reflex recovery curve, and the 10-m walking time were tested before and after the 1-month of treatment. RESULTS: In the ES group, the modified Ashworth scale showed a trend toward reduced spasticity after 1 month of treatment. The Fmax/Mmax ratio decreased from 8.10% +/- 4.84% to 4.00% +/- 1.36%; the H-reflex latency increased from 28.87 +/- 2.45 ms to 29.40 +/- 2.57 ms; the H-reflex recovery curves indicated a downward shift; and the 10-metre walking time significantly decreased after ES. In the control group, none of the measures showed a statistically significant change. CONCLUSIONS: In this study, we demonstrated a way to suppress spasticity at a metameric site and to increase walking speed effectively by applying surface ES on the muscle-tendon junction of spastic gastrocnemius muscles.
Adult↗
Analysis of sonographic features for the differentiation of benign and malignant breast tumors of different sizes.
OBJECTIVE: To analyze the value of various sonographic features in differentiating benign from malignant breast tumors of different sizes to improve the diagnostic accuracy in small lesions. METHODS: The sonographic features of 1203 histologically confirmed solid breast lesions were prospectively documented with respect to anteroposterior (AP) diameter/width ratio, shape, margin, echogenicity, echotexture, posterior echo and bilateral refraction sign. The sensitivity, specificity and accuracy of breast ultrasound were calculated for lesions grouped according to size (< or = 1, 1.1-2 and > 2 cm). Univariate and multiple logistic regression analyses including calculation of odds ratios for single sonographic features were used to analyze the significance of the different diagnostic features. RESULTS: The accuracy of breast sonography in differentiating between benign and malignant tumors < or = 1, 1.1-2 and > 2 cm in size was 75.6%, 86.4% and 88.4%, respectively. Univariate analysis demonstrated that all sonographic features were significant in tumors > or = 1.1 cm. Shape, margin, echogenicity and echotexture were the significant factors in those tumors < or = 1 cm. Multiple logistic regression analysis demonstrated that margin, shape, posterior echo and echogenicity were the significant factors for differential diagnosis in tumors > 2 cm. Echogenicity, margin, shape, bilateral refraction sign and echotexture were the significant factors for tumors 1.1-2 cm. On multiple regression analysis, margin was the only significant factor for tumors < or = 1 cm. CONCLUSION: Tumor margin is the most important sonographic feature in evaluating breast lesions in any size group. With the combination of significant factors and emphasis on specific features according to size of lesion, the diagnostic accuracy of ultrasound for the differential diagnosis of malignant and benign tumors may be improved.
Adolescent↗
Pregnancy outcomes with increased nuchal translucency after routine Down syndrome screening.
OBJECTIVES: The purpose of this study was to evaluate the outcomes of pregnancies with nuchal translucency greater or equal to 3 mm for routine first trimester screening in unselected populations. METHODS: A total of 2980 pregnant women for first trimester ultrasonography were routinely offered crown-rump length (CRL) and nuchal translucency (NT) for screening for Down syndrome between 11 and 14 weeks' gestation. A complete follow-up was obtained in all cases by a review of medical records. RESULTS: Using a cut-off value of 3 mm, the prevalence of increased fetal NT was 0.7% (n=22). Among the 22 cases, there were five (22.7%) chromosomal abnormalities. Of the 17 chromosomally normal pregnancies, four resulted in fetal demise (spontaneous abortion, intrauterine death or termination of pregnancy due to fetal abnormalities). The remaining 13 pregnancies resulted in live births, including one gestational hypertension and one preterm delivery, respectively. The total incidence of an adverse outcome in the group of increased fetal NT was 45.5%. CONCLUSIONS: In a routine population with first-trimester ultrasonography, fetal NT measuring greater than or equal to 3 mm was associated with a poor pregnancy outcome with not only chromosomal abnormalities and congenital cardiac diseases, but also poor maternal and fetal health or adverse pregnancy outcomes. In addition, this study also demonstrated the necessity for fetal assessment and follow-up in cases where the fetal NT is increased in the first trimester.
Adolescent↗
In vitro folate supplementation alleviates oxidative stress, mitochondria-associated death signalling and apoptosis induced by 7-ketocholesterol.
Folate has recently been proposed as a new antioxidant. Folate supplementation may have a protective effect in counteracting oxidant-induced apoptotic damage. The present studies were undertaken to examine whether there is a direct link between folate levels, antioxidant capability and reduced apoptotic damage. Using an in vitro cellular model of 7-ketocholesterol (KC)-induced apoptosis, U937 cells were pre-cultured with a folate-deficient medium supplemented with various levels of folate (2-1500 micromol/l) before treatment with 7-KC. Apoptotic markers, mitochondria-associated death signals and levels of reactive oxygen species were assayed. After treatment with 7-KC for 30 h, low and high levels of folate supplementation significantly (P<0.05) reduced nuclear DNA loss. Only high levels of folate supplementation (>1000 micromol/l) were effective in counteracting 7-KC-promoted apoptotic membrane phosphatidylserine exposure and DNA laddering. The attenuation of 7-KC-induced apoptotic damage by high-dose folate supplementation coincided with a partial normalization of mitochondria membrane potential dissipation, a suppression of cytochrome c release and an inhibition of procaspase 3 activation. The prevention of mitochondrial dysfunctions and apoptotic processes was associated with antioxidant actions of high-dose folate by a marked scavenging of intracellular superoxide. Collectively, our present results demonstrate that in vitro folate supplementation exerts differentially protective effects against 7-KC-induced damage. High-dose supplementation alleviates oxidative stress, mitochondria-associated death signalling and apoptosis induced by 7-KC. However, the in vivo relevance is not clear and requires further study.
Antioxidants↗