[Functional outcomes of 100 patients with adenocarcinoma of the esophagogastric junction undergoing Cheng's GIRAFFE(®) reconstruction after proximal gastrectomy].

Objective: To investigate the functional outcomes and postoperative complications of Cheng's GIRAFFE reconstruction after proximal gastrectomy. Methods: A descriptive case series study was conducted. Clinical data of 100 patients with adenocarcinoma of the esophagogastric junction who underwent Cheng's GIRAFFE reconstruction after proximal gastrectomy in Cancer Hospital of University of Chinese Academy of Sciences (64 cases), Zhejiang Provincial Hospital of Chinese Medicine (24 cases), Lishui Central Hospital (10 cases), Huzhou Central Hospital (1 case) and Ningbo Lihuili Hospital (1 case) from September 2017 to June 2021 were retrospectively analyzed. Of 100 patients, 64 were males and 36 were females; the mean age was (61.3 ± 11.1) years and the BMI was (22.7±11.1) kg/m(2). For TNM stage, 68 patients were stage IA, 24 were stage IIA and 8 were stage IIB. Postoperative functional results and postoperative complications of radical gastrectomy with Giraffe reconstruction were analyzed and summarized. Gastroesophageal reflux disease questionnaire (RDQ) score and postoperative endoscopy were used to evaluate the occurrence of reflux esophagitis and its grade (grade N, grade A, grade B, grade C, and grade D from mild to severe reflux). The continuous data conforming to normal distribution were expressed as (mean ± standard deviation), and those with skewed distribution were presented as median (Q1, Q3). Results: All the 100 patients successfully completed R0 resection, including 77 patients undergoing laparoscopic surgery and 23 patients undergoing laparotomy. The Giraffe anastomosis time was (38.6±14.0) min; the blood loss was (73.0±18.4) ml; the postoperative hospital stay was 9.5 (8.2, 13.0) d; the hospitalization cost was (6.0±0.3) ten thousand yuan. Fourteen cases developed perioperative complications (14.0%), including 7 cases of pleural effusion or pneumonia, 3 cases of anastomotic leakage, 2 cases of gastric emptying disorder, 1 case of gastrointestinal hemorrhage and 1 case of anastomotic stenosis, who were all improved and discharged after symptomatic management. Patients were followed up for (33.3±1.6) months. Eight patients were found to have reflux symptoms by RDQ scale six months after surgery, and 11 patients (11/100,11.0%) were found to have reflux esophagitis by gastroscopy, including 6 in grade A, 3 in grade B, and 2 in grade C. All the patients could control their reflux symptoms with behavioral guidance or oral PPIs. Conclusion: Cheng's GIRAFFE reconstruction has good anti-reflux efficacy and gastric emptying function; it can be one of the choices of reconstruction methods after proximal gastrectomy.

[Clinical features and survival analysis in non-M(3) acute myeloid leukemia patients with ASXL1 gene mutation].

Objective: To examine the survival rates and clinical characteristics of people with newly discovered non-M(3) acute myeloid leukemia (AML) who carry the ASXL1 gene mutation. Methods: From January 2016 to April 2021, the clinical information of patients with newly diagnosed non-M(3) AML at Shandong University's Qilu Hospital was retrospectively examined, and their clinical characteristics and survival were compared and analyzed. Gene mutation was detected by next-generation sequencing. Results: ① The study included 256 AML patients who were initially diagnosed and had complete data, including 47 cases of ASXL1 gene mutation-positive (ASXL1(+)) patients and 209 cases of ASXL1 gene mutation-negative (ASXL1(-)) patients. All patients were divided into three groups: elderly (≥60 years old, n=92) , middle-aged (45-59 years old, n=92) , and young (≤44 years old, n=72) . ②WBC, and age were higher in patients with ASXL1 mutations compared to ASXL1(-) patients, while complete response after the first round of treatment (CR(1)) was lower (P<0.05) . In the elderly group, WBC and the proportion of aberrant cells in nuclear cells in ASXL1(+) patients were higher than those in ASXL1(-) patients (P<0.05) . In the young group, the WBC of ASXL1(+) patients was higher than that of ASXL1(-) patients (z=-2.314, P=0.021) . ③IDH2 mutation and ASXL1 mutation was related (P=0.018, r=0.34) . In ASXL1(+) patients, the proportion of peripheral blasts in the high VAF group (VAF>40% ) was higher than that in the low VAF group (VAF<20% ) , and the proportion of aberrant nuclear cells was higher in the duplication and replacement mutation patients than in the deletion mutation patients (P<0.05) . ④The overall survival (OS) and progression-free survival (PFS) of ASXL1(+) patients were shorter than those of ASXL1(-) patients (median, 10 months vs 20 months, 10 months vs 17 months; P<0.05) . The proportion number of aberrant cells in nuclear cells (≥20% ) , complex karyotypes, and TET2 mutation were all independent risk variables that had an impact on the prognosis of ASXL1(+) patients, according to multivariate analysis (P<0.05) . Conclusion: ASXL1-mutated non-M(3) AML patients have higher WBC in peripheral blood, a higher proportion of aberrant cells in nuclear cells, lower CR(1) rate, and shorter OS and PFS. Additionally, a poor prognosis is linked to higher VAF, duplication, and substitution mutations in the ASXL1 gene, as well as the high proportion of aberrant cells in nuclear cells, complex karyotype, and TET2 mutation.

Serum CXCL13 and PECAM-1 can be used as diagnostic and prognostic markers in elderly patients with gastric cancer.

PURPOSE: To investigate the application value of serum CXC Chemokine-13 (CXCL-13) and platelet endothelial cell adhesion molecule-1 (PECAM-1) in elderly patients with gastric cancer (GC). METHODS: Ninety-eight elderly GC patients admitted to the Affiliated Hexian Memorial Hospital of Southern Medical University were selected as a research group, and 60 healthy subjects of the same age and in relatively good health who underwent physical examination at the same period were selected as a control group. Enzyme-linked immunosorbent assay (ELISA) was used to detect the levels of CXCL13 and PECAM-1 in serum. The clinical diagnosis and prognostic value of serum CXCL13 and PECAM-1 in elderly GC patients were analyzed. RESULTS: The levels of CXCL13 and PECAM-1 in serum of the research group were significantly higher than those of the control group (P < 0.001). The AUC value of combined diagnosis of elderly GC patients by serum CXCL13 and PECAM-1 was 0.950, and that of combined evaluation of prognosis of patients was 0.849. Serum CXCL13 and PECAM-1 were significantly related to TNM staging, differentiation degree and tumor diameter in elderly GC patients (P < 0.05). High levels of CXCL13 and PECAM-1 were significantly associated with lower 5-year OS (P < 0.05). CONCLUSION: Elderly GC patients with higher TNM staging, longer tumor diameters, high levels of CXCL13 and PECAM-1 had an increased risk of poor prognosis. Serum CXCL13 and PECAM-1 can be used as effective indicators for diagnosis and prognosis of elderly patients with GC, and can predict the 5-year OS in patients.

LncRNA GAS5 affects epithelial-mesenchymal transition and invasion of breast cancer cells by regulating miR-216b.

OBJECTIVE: To study the mechanism of lncRNA GAS5 affecting epithelial-mesenchymal transition and invasion of breast cancer cells by regulating miR-216b. PATIENTS AND METHODS: Quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) was used to detect the expressions of GAS5 and miR-216b in breast cancer and paracancerous tissues. The relationship between GAS5 and clinicopathological parameters of breast cancer patients was analyzed. The Dual-Luciferase reporter gene was used to detect the interaction between GAS5 and miR-216b and the transwell invasion assay was used to detect the invasive ability of lung cancer cells after GAS5 inhibition. Apoptosis assay was used to detect the apoptosis of breast cancer cells after GAS5 inhibition. Western blotting and immunofluorescence staining were used to detect the inhibition of GAS5 epithelial-mesenchymal transition. RESULTS: Compared with paracancerous tissues, in breast cancer tissues, the expression of GAS5 was increased and the expression of miR-216b was decreased. As the patients enter the later stages of breast cancer, the expression level of GAS5 in breast cancer patients was significantly elevated. The expression of GAS5 in the tissues with lymph node metastasis of breast cancer was markedly increased. The inhibition of GAS5 can promote the apoptosis of breast cancer cells; GAS5 can specifically bind to the 3' UTR of miR-216b. The expression of GAS5 inhibited the expression of E-cadherin in breast cancer cells and significantly upregulated N-cadherin, which has been confirmed by immunofluorescence staining experiments. CONCLUSIONS: GAS5 plays an important role in the development of breast cancer. GAS5 can target on miR-216b to regulate the biological behavior and epithelial-mesenchymal transition of breast cancer cells.

MicroRNA-760 inhibits the biological progression of colorectal carcinoma by directly targeting FOXA1 and regulating epithelial-to-mesenchymal transition and PI3K/AKT signaling pathway.

OBJECTIVE: Colorectal carcinoma (CRC) is one of the most common factors for tumor-associated mortalities globally. In recent years, microRNAs (miRNAs) have been identified as novel therapeutic biomarkers for cancer treatment. The purpose of the current study was to unravel the clinical significance and underlying molecular mechanisms of miR-760 in CRC progression. PATIENTS AND METHODS: Fifty-four pairs of CRC tissue samples and adjacent para-carcinoma tissue samples were collected from CRC patients who underwent surgical resection. We measured miR-760 expressions in CRC using quantitative Real-time polymerase chain reaction (qRT-PCR) analysis. MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assays and transwell assays were performed to determine the functions of miR-760 in CRC cell proliferation, invasion and migration. Dual-luciferase reporter assays and Western blots were used to investigate the underlying molecular mechanisms. Moreover, the association between miR-760 expressions and clinicopathological features was analyzed. RESULTS: In this study, the results showed that the down-regulated miR-760 expressions were related to the poor prognosis and malignant clinicopathologic features of CRC patients. Furthermore, functional assays revealed that miR-760 restoration obviously suppressed CRC cell proliferation, migration and invasion through modulating phosphatidylinositol 3-kinase/ protein kinase B (PI3K/AKT) pathway and epithelial-mesenchymal transition (EMT). FOXA1 was also considered as a functional target of miR-760 in CRC cells. Furthermore, miR-760 up-regulation also significantly repressed tumorigenesis in vivo. CONCLUSIONS: These results suggested that miR-760 exerted cancer-suppressive functions in CRC, providing a therapeutic strategy for CRC treatment.

The role of rectus muscle myectomy in the management of large-angle strabismus for Graves' ophthalmopathy.

PurposeRetrospective noncomparative case series to investigate the role of rectus muscle myectomy for the treatment of large-angle strabismus in patients with Graves' ophthalmopathy.Patients and methodsData from 47 consecutive patients with Graves' ophthalmopathy who underwent complete myectomy for large-angle strabismus (strabismus greater than 25 prism diopters (PDs)) were collected retrospectively. Pre- and postoperative deviations in primary and reading position were measured in PDs. Postoperative deviation of <5 diopters in primary gaze and functional binocular vision in central 30° field were considered as successful surgical outcomes.ResultsPatients undergoing complete myectomy of the restricted muscles in large-angle strabismus achieved a 78.7% success rate after the first surgery. Reoperation performed on seven patients resulted in 85.7% success rate in reoperation group. The overall success rate was 91.5%. The mean efficacy of the isolated rectus muscle myectomy was 34.3±7.7 PDs.ConclusionsThe complete rectus muscle myectomy technique is effective and predictable in the treatment of large-angle strabismus in patients with Graves' ophthalmopathy.

TGF-ß1 polymorphisms and familial aggregation of liver cancer in Guangxi, China.

The goal of present study was to investigate the relationship between polymorphisms of TGF-ß1 and familial aggregation of liver cancer in Guangxi Zhuang, Han, and Yao populations. We conducted a population-based case-control family study of liver cancer in Guanxi, China. A total of 214 individuals from 37 case families were surveyed for polymorphisms in TGF-ß1. We genotyped six functional TGF-ß1 polymorphisms: rs1800469, rs2241715, rs2241716, rs11466345, rs8105161, and rs747857. Levels of TGF-ß1, hepatitis B surface antigen, and anti-hepatitis C virus in all serum samples were detected using the enzyme-linked immunoassay method, and presence of hepatitis B virus (HBV) DNA was determined using polymerase chain reaction amplification. A standardized questionnaire was used to collect information from subjects, including alcohol consumption, smoking, eating, and water drinking habits. The results were compared with those from 214 control individuals. The results showed that the TGF-ß1 genotypes rs1800469, rs2241715, rs2241715, and rs8105161 were more frequent in patients than in controls. The risk factors for familial aggregation of liver cancer in Guangxi were determined, from high to low, to be: drinking sugared beverages > alcohol consumption > HBV DNA-positive > rs1800469 TT homozygous genotype > rs2241715 TT homozygous genotype. The results suggested that TGF-ß1 rs1800469 TT and rs2241715 TT homozygote genotypes represent the genetic factors underlying familial clustering of liver cancer in Guangxi, and that drinking water use, alcohol consumption, and testing positive for HBV DNA are the main environmental factors contributing to familial aggregation of liver cancer in Guangxi.

Increased 8-hydroxy-2'-deoxyguanosine in plasma and decreased mRNA expression of human 8-oxoguanine DNA glycosylase 1, anti-oxidant enzymes, mitochondrial biogenesis-related proteins and glycolytic enzymes in leucocytes in patients with systemic lupus erythematosus.

We measured plasma levels of the oxidative DNA damage marker 8-hydroxy-2'-deoxyguanosine (8-OHdG) and leucocyte mRNA expression levels of the genes encoding the 8-OHdG repair enzyme human 8-oxoguanine DNA glycosylase 1 (hOGG1), the anti-oxidant enzymes copper/zinc superoxide dismutase (Cu/ZnSOD), manganese superoxide dismutase (MnSOD), catalase, glutathione peroxidase-1 (GPx-1), GPx-4, glutathione reductase (GR) and glutathione synthetase (GS), the mitochondrial biogenesis-related proteins mtDNA-encoded ND 1 polypeptide (ND1), ND6, ATPase 6, mitochondrial transcription factor A (Tfam), nuclear respiratory factor 1(NRF-1), pyruvate dehydrogenase E1 component alpha subunit (PDHA1), pyruvate dehydrogenase kinase isoenzyme 1 (PDK-1) and hypoxia inducible factor-1α (HIF-1α) and the glycolytic enzymes hexokinase-II (HK-II), glucose 6-phosphate isomerase (GPI), phosphofructokinase (PFK), glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and lactate dehydrogenase A (LDHa). We analysed their relevance to oxidative damage in 85 systemic lupus erythematosus (SLE) patients, four complicated SLE patients undergoing rituximab treatment and 45 healthy individuals. SLE patients had higher plasma 8-OHdG levels (P < 0·01) but lower leucocyte expression of the genes encoding hOGG1(P < 0·01), anti-oxidant enzymes (P < 0·05), mitochondrial biogenesis-related proteins (P < 0·05) and glycolytic enzymes (P < 0·05) than healthy individuals. The increase in plasma 8-OHdG was correlated positively with the elevation of leucocyte expression of the genes encoding hOGG1 (P < 0·05), anti-oxidant enzymes (P < 0·05), several mitochondrial biogenesis-related proteins (P < 0·05) and glycolytic enzymes (P < 0·05) in lupus patients. The patients, whose leucocyte mtDNA harboured D310 heteroplasmy, exhibited a positive correlation between the mtDNA copy number and expression of ND1, ND6 and ATPase 6 (P < 0·05) and a negative correlation between mtDNA copy number and systemic lupus erythematosus disease activity index (SLEDAI) (P < 0·05), as well as plasma 8-OHdG (P < 0·05). In particular, four complicated SLE patients with increased expression of the genes encoding the anti-oxidant enzymes, GAPDH, Tfam and PDHA1, experienced better therapeutic outcomes after rituximab therapy. In conclusion, higher oxidative damage with suboptimal increases in DNA repair, anti-oxidant capacity, mitochondrial biogenesis and glucose metabolism may be implicated in SLE deterioration, and this impairment might be improved by targeted biological therapy.

Microdialysis: a technique for pharmacokinetic-pharmacodynamic studies of oncological drugs.

Solid tumors have several barriers that may limit drug penetration and provide inherent mechanisms of resistance. Therefore, the evaluation of antineoplastic agents should base on tumor drug exposure and antitumor activity. Owing to selective access to the extracellular space of the tumor, which acts as target site for most antineoplastic drugs, monitoring drug disposition and corresponding antitumor activity, microdialysis (MD), a probe-based sampling technique, satisfies regulatory requirements for pharmacokinetic- pharmacodynamic (PK-PD) studies. MD is a powerful tool for PK-PD studies of oncological drugs, which would allow better understanding of exposure-response relationships and contributes to the research and development of oncological drugs. Recent progresses in the development of MD for estimating PK-PD studies of oncological drugs are summarized in this review. Special preclinical application examples of MD for PK-PD studies of oncological drugs organized by types of antineoplastic drugs and informations collected are also described. In conclusion, the role of MD in preclinical PK-PD studies of oncological drugs has been confirmed and it has provided a strong foundation for further clinical research.

Mitochondrial dysfunction-induced amphiregulin upregulation mediates chemo-resistance and cell migration in HepG2 cells.

The aim of this study was to investigate the contribution of mitochondrial dysfunction to chemoresistance and migration of hepatoma cells. We found that inhibition of mitochondrial respiration and mitochondrial DNA (mtDNA) depletion resulted in induction of amphiregulin (AR) expression in HepG2 cells. Upon oligomycin treatment of HepG2 cells, the cytosolic Ca(2+) was significantly raised after 30 min, and the intracellular level of reactive oxygen species (ROS) was elevated 2.2-fold after 4 h. Moreover, the condition medium of oligomycin-treated HepG2 cells was found to stimulate the migration of SK-Hep-1 cells. On the other hand, oligomycin-induced cisplatin-resistance and cell migration of HepG2 cells were attenuated by AR-specific RNA interference (#L-017435, Dharmacon) and a neutralizing antibody (MAB262, R&D Systems), respectively. Together, these findings suggest that mitochondrial dysfunction induced Ca(2+) mobilization, and ROS overproduction, which modulated the chemo-resistance and migration of hepatoma cells through the induction and activation of AR.

Oxidative stress in patients with Graves' ophthalmopathy: relationship between oxidative DNA damage and clinical evolution.

PURPOSE: To evaluate the relationship between oxidative stress and clinical evolution in patients with Graves' ophthalmopathy (GO). METHODS: Thirty-one euthyroid GO patients and 25 healthy subjects participated in this study. Oxidative DNA damage was assessed by determination of the 8-hydroxy-2'-deoxyguanosine (8-OHdG) level in urine by ELISA. The relationship of oxidative DNA damage to the clinical evolutions of GO, especially the smoking status, clinical activity scores (CAS), and ophthalmopathy index was examined. RESULTS: The mean 8-OHdG was significantly higher in GO patients than that of normal controls (12.6+/-5.7 vs 6.7+/-2.5 ng/mg creatinine, P<0.001). Smokers had significant higher 8-OHdG than did never smokers in GO patients (P=0.029), but not in healthy controls (P=0.374). Among GO patients, only CAS remained significantly correlated with 8-OHdG (P=0.001) after adjusting for age, sex, disease duration, the status of antithyroid drug and smoking, and thyroid-stimulating hormone level. Patients with active GO (CAS>3) had higher 8-OHdG than did the patients with CAS

Cadmium-induced autophagy and apoptosis are mediated by a calcium signaling pathway.

The cytotoxicity of cadmium (Cd) induced autophagy and apoptosis in MES-13 cells was determined by flow cytometry. Autophagy was also assessed by formation of autophagosomes and processing of LC3. Pharmacological inhibition of autophagy resulted in increased of cell viability, suggesting autophagy plays a role in cell death in Cd-treated mesangial cells. Cd also induced a rapid elevation in cytosolic calcium ([Ca(2+)](i) ), and modulation of [Ca(2+)](i) via treatment with IP (3)R inhibitor or knockdown of calcineurin resulted in a change in the proportion of cell death, suggesting that the release of calcium from the ER plays a crucial role in Cd-induced cell death. Inhibition of Cd-induced ERK activation by PD 98059 suppressed Cd-induced autophagy, and BAPTA-AM eliminated activation of ERK. BAPTA-AM also inhibited Cd-induced mitochondrial depolarization and activation of caspases. These findings demonstrated that Cd induces both autophagy and apoptosis through elevation of [Ca(2+)](i), followed by Ca(2+)-ERK and Ca(2+)-mitochondria-caspase signaling pathways.

Alteration of the copy number and deletion of mitochondrial DNA in human hepatocellular carcinoma.

Somatic mutations in mitochondrial DNA (mtDNA) have been detected in hepatocellular carcinoma (HCC). However, it remains unclear whether mtDNA copy number and mitochondrial biogenesis are altered in HCC. In this study, we found that mtDNA copy number and the content of mitochondrial respiratory proteins were reduced in HCCs as compared with the corresponding non-tumorous livers. MtDNA copy number was significantly reduced in female HCC but not in male HCC. Expression of the peroxisome proliferator-activated receptor gamma coactivator-1 was significantly repressed in HCCs (P<0.005), while the expression of the mitochondrial single-strand DNA-binding protein was upregulated, indicating that the regulation of mitochondria biogenesis is disturbed in HCC. Moreover, 22% of HCCs carried a somatic mutation in the mtDNA D-loop region. The non-tumorous liver of the HCC patients with a long-term alcohol-drinking history contained reduced mtDNA copy number (P<0.05) and higher level of the 4977 bp-deleted mtDNA (P<0.05) as compared with non-alcohol patients. Our results suggest that reduced mtDNA copy number, impaired mitochondrial biogenesis and somatic mutations in mtDNA are important events during carcinogenesis of HCC, and the differential alterations in mtDNA of male and female HCC may contribute to the differences in the clinical manifestation between female and male HCC patients.

Genetic polymorphism of hOGG1 and risk of pterygium in Chinese.

PURPOSE: Ultraviolet irradiation is known to cause oxidative DNA damage and is thought to be a major factor implicated in the pathogenesis of pterygium. The highly mutagenic 8-hydroxy-2'-deoxyguanosine, a marker for the evaluation of photo-oxidative DNA damage, can be repaired by human 8-oxoguanine glycosylase I (hOGG1). A transition of C to G at nucleotide position 1245 in exon 7 of the hOGG1 gene is associated with the substitution of cysteine for serine at codon 326. In this study, we investigated the association of the hOGG1 Ser326Cys polymorphism with pterygium in a Chinese population. METHODS: In all, 70 patients and 86 controls were enrolled in this study. The Ser326Cys polymorphism was determined by the polymerase chain reaction-restriction fragment-length polymorphism analysis. The association between this genetic polymorphism and risk of pterygium was examined by chi(2)-test and logistic regression. RESULTS: The allelic frequencies for the Ser and Cys variants of hOGG1 gene were not significantly different between the two groups. However, when compared with Ser/Ser and Ser/Cys genotypes combined, we found that the homozygous Cys/Cys genotype was more prevalent in pterygium patients than controls (P=0.024) with the odds ratio being 2.2 (95% CI: 1.1-4.5). In the pterygium group, the mean age of patients with the Cys/Cys genotype was younger than those with the other two genotypes (P=0.025). CONCLUSIONS: Our findings suggest that the 1245C --> G transition in exon 7 of the hOGG1 gene, which results in Ser326Cys substitution of the enzyme, might play a role in the susceptibility of humans to pterygium.

Mutations at the mitochondrial DNA polymerase (POLG) locus associated with male infertility.

Human mitochondrial DNA polymerase, encoded by POLG, contains a polyglutamine tract encoded by a CAG microsatellite repeat. Analysis of POLG genotypes in different populations identified an association between absence of the common, ten-repeat allele and male infertility typified by a range of sperm quality defects but excluding azoospermia.

Accumulation of mitochondrial DNA deletions in human oral tissues -- effects of betel quid chewing and oral cancer.

Accumulation of mitochondrial DNA (mtDNA) mutations in human tissues has been associated with intrinsic aging and environmental insult. Recently, mtDNA mutations have been detected in various tumors, including head and neck tumors. However, the factors affecting the occurrence and accumulation of mtDNA deletions in tumor tissues are poorly understood. In Taiwan, betel quid chewing is a major risk factor for oral cancer. Using polymerase chain reaction (PCR) techniques, we examined large-scale deletions of mtDNA in 53 pairs of tumor and non-tumor oral tissues from the patients with or without betel quid chewing history. The results revealed that irrespective of the history of betel quid chewing, the incidences of the 4977bp deletion and other deletions of mtDNA were lower in the tumor portion as compared with the non-tumor portion. The average proportions of the 4977bp deleted mtDNA in the tumor tissues of the betel quid chewers and non-betel quid chewers were 13- and 5-fold, respectively, lower than those in the corresponding non-tumor tissues. Moreover, the average proportion of 4977bp deleted mtDNA was significantly higher (P<0.05) in the non-tumor oral tissues of the patients with betel quid chewing history than that of the patients without the history of betel quid chewing. These results suggest that betel quid chewing may increase mtDNA mutation in human oral tissues and that accumulation of mtDNA deletions and subsequent cytoplasmic segregation of these mutations during cell division could be an important contributor to the early phase of oral carcinogenesis.

Erythropoietin and iron: the role of ascorbic acid.

Provision of sufficient available iron is a prerequisite to ensure the optimal response to recombinant human erythropoietin (rHuEpo). Functional iron deficiency (a state when iron supply is reduced to meet the demands for increased erythropoiesis) is the common cause of rHuEpo hyporesponsiveness in dialysis patients who have normal iron status, even when they are iron-overloaded. Iron supplementation is not justified for this hyporesponsiveness in patients with iron overload due to the potential hazards of iron overload aggravated by intravenous iron therapy. Furthermore, in vivo studies indicated that the promising effect of intravenous iron medication to overcome iron-deficient erythropoiesis is not observed in iron-overloaded haemodialysis (HD) patients. Ascorbic acid, a water-soluble antioxidant as well as a reducing agent, has a number of associations with iron metabolism. Recent research highlights that ascorbic acid can potentiate the mobilization of iron from inert tissue stores and facilitates the incorporation of iron into protoporphyrin in iron-overloaded HD patients being treated with rHuEpo. Interest has turned towards the use of ascorbic acid as an adjuvant therapy in this field. This review focuses on the improvement of rHuEpo response by administration of ascorbic acid and discusses its clinical implications and potential issues for nephrologists.

Oxidative stress in human aging and mitochondrial disease-consequences of defective mitochondrial respiration and impaired antioxidant enzyme system.

Respiratory function of mitochondria is compromised in aging human tissues and severely impaired in the patients with mitochondrial disease. A wide spectrum of mitochondrial DNA (mtDNA) mutations has been established to associate with mitochondrial diseases. Some of these mtDNA mutations also occur in various human tissues in an age-dependent manner. These mtDNA mutations cause defects in the respiratory chain due to impairment of the gene expression and structure of respiratory chain polypeptides that are encoded by the mitochondrial genome. Since defective mitochondria generate more reactive oxygen species (ROS) such as O2- and H2O2 via electron leak, we hypothesized that oxidative stress is a contributory factor for aging and mitochondrial disease. This hypothesis has been supported by the findings that oxidative stress and oxidative damage in tissues and culture cells are increased in elderly subjects and patients with mitochondrial diseases. Another line of supporting evidence is our recent finding that the enzyme activities of Cu,Zn-SOD, catalase and glutathione peroxidase (GPx) decrease with age in skin fibroblasts. By contrast, Mn-SOD activity increases up to 65 years of age and then slightly declines thereafter. On the other hand, we observed that the RNA, protein and activity levels of Mn-SOD are increased two- to three-fold in skin fibroblasts of the patients with CPEO syndrome but are dramatically decreased in patients with MELAS or MERRF syndrome. However, the other antioxidant enzymes did not change in the same manner. The imbalance in the expression of these antioxidant enzymes indicates that the production of ROS is in excess of their removal, which in turn may elicit an elevation of oxidative stress in the fibroblasts. Indeed, it was found that intracellular levels of H2O2 and oxidative damage to DNA and lipids in skin fibroblasts from elderly subjects or patients with mitochondrial diseases are significantly increased as compared to those of age-matched controls. Furthermore, Mn-SOD or GPx-1 gene knockout mice were found to display neurological disorders and enhanced oxidative damage similar to those observed in the patients with mitochondrial disease. These observations are reviewed in this article to support that oxidative stress elicited by defective respiratory function and impaired antioxidant enzyme system plays a key role in the pathophysiology of mitochondrial disease and human aging.

Evidence for alterations in circulating low-molecular-weight antioxidants and increased lipid peroxidation in smokers on hemodialysis.

BACKGROUND/AIM: Cardiovascular disease is the major cause of mortality in dialysis patients, accounting for about 40% of deaths in most large registries. Oxidative stress has been strongly implicated in the pathogenesis of these events. As end-stage renal disease is a state of elevated free radical activity, the aim of the present study was to investigate the negative impact of smoking in 57 male hemodialysis patients. METHODS: The patients, who were 20-85 years of age (mean age 51.0 +/- 14 years), had been on hemodialysis for at least 6 months before participating in this study. Fasting blood sampling for serum lipid, albumin, urate and lipophilic antioxidants such as tocopherols, carotenes, ascorbate and lipid peroxides was performed. RESULTS: The plasma malondialdehyde (MDA) concentration was significantly higher in hemodialysis patients who smoked compared to hemodialysis patients who were nonsmokers (1.92 +/- 0.52 vs. 1.59 +/- 0.42 nmol/ml, p = 0.006). No association was found between levels of MDA in smokers and parameters such as body mass index, serum cholesterol, serum triglycerides and smoking index. There were no significant differences in the plasma levels of uric acid, alpha-tocopherol, gamma-tocopherol, delta-tocopherol, alpha-carotene, beta-carotene and retinol between the two groups. A significantly lower level of plasma ascorbate was observed in hemodialysis patients who smoked compared to the nonsmoking hemodialysis patients or healthy controls (4.59 +/- 4.0 vs. 9.57 +/- 4.0 and 10.16 +/- 4.6 microg/ml, p < 0.05). Moreover, in smokers, the plasma levels of ascorbate were negatively correlated with the levels of plasma MDA (r = -0.43, p < 0.001) of each patient. Partial correlation analysis of the plasma levels of the measured antioxidants and the smoking index revealed a negative correlation between the plasma levels of lipid-normalized lycopene and the smoking index (r = -0.53, p < 0.05). CONCLUSION: Our data suggest that cigarette smoking further increases plasma-circulating products of lipid peroxidation, which are already increased in nonsmoking hemodialysis patients as compared to matched healthy controls. The lower plasma levels of ascorbate in hemodialysis patients who smoke suggest that these patients may be more susceptible to oxidative tissue damage caused by smoking.

Detection of Epstein-Barr virus DNA in the peripheral-blood cells of patients with nasopharyngeal carcinoma: relationship to distant metastasis and survival.

PURPOSE: Nasopharyngeal carcinoma (NPC) has been proved to be an Epstein-Barr virus (EBV)-associated cancer. By use of nested polymerase chain reactions (PCRs), we examined whether the presence of EBV DNA in the peripheral-blood cells (PBC) can serve as a prognostic indicator for NPC. PATIENTS AND METHODS: Peripheral blood from 124 patients with NPC who had no evidence of distant metastasis and 114 healthy volunteers with serologically positive findings for EBV infection was collected prospectively. Plasma and erythrocytes were separated. DNA was extracted from PBCs and analyzed by a nested PCR using primers specific to Epstein-Barr virus nuclear antigen 1 (EBNA-1). All patients were treated by radiotherapy with or without chemotherapy. Clinical parameters and status of EBNA-1 in PBCs were used for survival analysis using the Kaplan-Meier method and the Cox proportional hazards model. RESULTS: Positive rates of EBNA-1 DNA in PBCs of NPC patients and healthy volunteers are 71% and 14%, respectively (P =.001). No significant difference was observed with regard to the clinical characteristics of patients who were EBNA-1-positive (n = 88) and those who were EBNA-1-negative (n = 36). After a median follow-up period of 38 months (range, 24 to 56 months), 29 of 88 EBNA-1-positive patients and only one of 36 EBNA-1-negative patients developed distant metastases (P =.00015). Kaplan-Meier estimates of overall survival (P =.0010), metastasis-free survival (P =.0004), and progression-free survival (P =.0004) were significantly lower for the patients in the EBNA-1-positive group than for those in the EBNA-1-negative group. Multivariate Cox analysis confirmed the same results. CONCLUSION: The presence of EBNA-1 DNA in PBCs is a novel, important risk factor for patients with NPC that indicates a significantly higher risk of developing distant metastasis as well as a lower survival rate.