Vitamin D nutritional status in early pregnancy and its relationship with periconceptional multiple micronutrients supplementation.

BACKGROUND AND OBJECTIVES: To assess the vitamin D nutritional status (VDN) of pregnant women in early pregnancy and investigate the effects of periconceptional supplementation with multiple micronutrients (MMs) on this status. METHODS AND STUDY DESIGN: Data were taken from the Pregnancy Health Care System and Hospital Information System in 2018 in Beijing. Vitamin D nutritional status in early pregnancy was evaluated among 4,978 pregnant women, and 4,540 women who took folic acid only (FA) or multiple mi-cronutrients supplements (MM) during the periconceptional period, were include to estimate the associations between periconceptional supplementation with MM and prevalence of vitamin D deficiency or insufficiency with logistic regression model. RESULTS: The mean early-pregnancy vitamin D concentration was 18.6 (±7.5) ng/mL, and the rates of deficiency and insufficiency were 31.6% and 60.5%, respectively. Compared to the FA group, the adjusted odds ratio (aOR, 95%confidence interval, CI) for insufficiency or deficiency of the MM group were 0.25(0.18-0.34), and the aOR (95%CI) for deficiency of the MM group were 0.17 (0.12-0.23). Women who took MMs for a longer period of time, at higher frequencies, and with higher compliance scores had lower rates of deficiency and insufficiency. In winter, spring, and autumn, taking MMs could reduce deficiency by about 70%; in summer, there was little effect. CONCLUSIONS: Among women in Beijing, serum concentrations of vitamin D in early pregnancy are relatively low, and the rates of deficiency and insufficiency are high. Taking MMs during the periconceptional period could improve this situation.

New ketamine analogue: 2-fluorodeschloro-N-ethyl-ketamine and its suggested metabolites.

Identifying new psychoactive substances (NPSs) and their metabolites is essential for regulating such substances for purposes of law enforcement and forensics. NPSs can be regulated on the basis of their chemical structures before they become a critical threat to society. Further, NPS metabolites can be targeted for analysis in urine, blood, and hair. This case study reports an incident in which 10 bags with approximately 15 g of crystalline material were seized from suspects by law enforcement officers and sent to the laboratory for confirmation. Gas chromatography-mass spectrometry, liquid chromatography-high-resolution mass spectrometry, and nuclear magnetic resonance (NMR) were employed to analyze these materials. The analyses revealed that the materials were a new ketamine analog, 2-fluorodeschloro-N-ethyl-ketamine (2-FDCNEK). Single-crystal X-ray diffraction (SXRD) analysis was also employed to confirm this result. In addition, metabolites of 2-FDCNEK were investigated using a fungal model and a urine sample from an abuser. The results suggest that 2-FDCNEK and 2-fluorodeschoro-norketamine are optimal metabolites for biological samples. This report presents the mass fragmentation, NMR analysis, and SXRD data of 2-FDCNEK. In addition, it provides suggestions regarding metabolites of 2-FDCNEK for law enforcement and forensic purposes, thereby facilitating the detection of this new ketamine analog.

Influence of Admission Time on Health Care Quality and Utilization in Patients with Stroke: Analysis for a Possible July Effect and Weekend Effect.

(1) Purpose: Undesirable health care outcomes could conceivably increase as a result of the entry of new, less experienced health care personnel into patient care during the month of July (the July effect) or as a result of the less balanced allocation of health care resources on weekends (the weekend effect). Whether these two effects were present in Taiwan's National Health Insurance (NHI) system was investigated. (2) Methods: The current study data were acquired from the NHI Research Database. The research sample comprised ≥18-year-old patients diagnosed as having a stroke for the first time from 1 January 2006 to 30 September 2012. The mortality rate within 30 days after hospitalization and readmission rate within 14 days after hospital discharge were used as health care quality indicators, whereas health care utilization indicators were the total length and cost of initial hospitalization. (3) Results: The results revealed no sample-wide July effect with regard to the four indicators among patients with stroke. However, an unexpected July effect was present among in-patients in regional and public hospitals, in which the total lengths and costs of initial hospitalization for non-July admissions were higher than those for July admissions. Furthermore, the total hospitalization length for weekend admissions was 1.06-1.07 times higher than that for non-weekend admissions; the total hospitalization length for weekend admissions was also higher than that for weekday admissions during non-July months. Thus, weekend admission did not affect the health care quality of patients with stroke but extended their total hospitalization length. (4) Conclusions: Consistent with the NHI's general effectiveness in ensuring fair, universally accessible, and high-quality health care services in Taiwan, the health care quality of patients examined in this study did not vary significantly overall between July and non-July months. However, a longer hospitalization length was observed for weekend admissions, possibly due to limitations in personnel and resource allocations during weekends. These results highlight the health care efficiency of hospitals during weekends as an area for further improvement.

Complement 3 and the Prognostic Nutritional Index Distinguish Kawasaki Disease from Other Fever Illness with a Nomogram.

OBJECTIVE: This study aimed to establish a model to distinguish Kawasaki disease (KD) from other fever illness using the prognostic nutritional index (PNI) and immunological factors. METHOD: We enrolled a total of 692 patients (including 198 with KD and 494 children with febrile diseases). Of those, 415 patients were selected to be the training group and 277 patients to be the validation group. Laboratory data, including the neutrophil-to-lymphocyte ratio (NLR), the platelet-to-lymphocyte ratio (PLR), the prognostic nutritional index (PNI), and immunological factors, were retrospectively collected for an analysis after admission. We used univariate and multivariate logistic regressions and nomograms for the analysis. RESULT: Patients with KD showed significantly higher C3 and a lower PNI. After a multivariate logistic regression, the total leukocyte count, PNI, C3, and NLR showed a significance (p < 0.05) and then performed well with the nomogram model. The areas under the ROC in the training group and the validation group were 0.858 and 0.825, respectively. The calibration curves of the two groups for the probability of KD showed a near agreement to the actual probability. CONCLUSIONS:  Compared with children with febrile diseases, patients with KD showed increased C3 and a decreased nutritional index of the PNI. The nomogram established with these factors could effectively identify KD from febrile illness in children.

Unexpected identification of a bupivacaine analog from smuggling by using single-crystal X-ray diffraction analysis: N-(2,6-dimethylphenyl)-1-phenethylpiperidine-2-carboxamide.

The identification of new psychoactive substances (NPSs) is essential against drug abuse, especially for "new" drugs that are not regulated by international drug conventions. A suspicious powder seized by the officers of Taipei Customs Administration of Taiwan was sent to this laboratory for analysis by using gas chromatography-mass spectrometry (GCMS), liquid chromatography-high resolution mass spectrometry (LCHRMS), proton nuclear magnetic resonance (1H NMR), carbon-13 nuclear magnetic resonance (13C NMR) with distortionless enhancement by polarization transfer (DEPT) at proton pulses of 45°, 90°, and 135°, two-dimensional correlation NMR measurements (2D_COSY), and heteronuclear single-quantum correlation NMR measurements (2D_HSQC). However, the structure of this "unknown" sample was difficult to identify. Alternatively, single-crystal X-ray crystallography was applied for structural determination after the crystallization of the compound in methanol. The structure was thus identified as N-(2,6-dimethylphenyl)-1-phenethylpiperidine-2-carboxamide (NDMPPPC), an analog of bupivacaine with similar pharmacological effects to those of cocaine, ketamine and morphine. The identification of NDMPPPC is in accordance with all mass fragments and NMR signal data, demonstrating that single-crystal X-ray diffraction can be used for structural determination, especially for complicated structures of "new" drugs or "unknown" samples. The seizure of NDMPPPC from smuggling indicates a great potential to become part of the next generation of NPSs.

A Nomogram Model Identifies Eosinophilic Frequencies to Powerfully Discriminate Kawasaki Disease From Febrile Infections.

Background: Kawasaki disease (KD) is a form of systemic vasculitis that occurs primarily in children under the age of 5 years old. No single laboratory data can currently distinguish KD from other febrile infection diseases. The purpose of this study was to establish a laboratory data model that can differentiate between KD and other febrile diseases caused by an infection in order to prevent coronary artery complications in KD. Methods: This study consisted of a total of 800 children (249 KD and 551 age- and gender-matched non-KD febrile infection illness) as a case-control study. Laboratory findings were analyzed using univariable, multivariable logistic regression, and nomogram models. Results: We selected 562 children at random as the model group and 238 as the validation group. The predictive nomogram included high eosinophil percentage (100 points), high C-reactive protein (93 points), high alanine transaminase (84 points), low albumin (79 points), and high white blood cell (64 points), which generated an area under the curve of 0.873 for the model group and 0.905 for the validation group. Eosinophilia showed the highest OR: 5.015 (95% CI:-3.068-8.197) during multiple logistic regression. The sensitivity and specificity in the validation group were 84.1 and 86%, respectively. The calibration curves of the validation group for the probability of KD showed near an agreement to the actual probability. Conclusion: Eosinophilia is a major factor in this nomogram model and had high precision for predicting KD. This report is the first among the existing literature to demonstrate the important role of eosinophil in KD by nomogram.

A novel nomogram model for differentiating Kawasaki disease from sepsis.

Kawasaki disease (KD) is a form of systemic vasculitis that occurs in children under the age of 5 years old. Due to prolonged fever and elevated inflammatory markers that are found in both KD and sepsis, the treatment approach differs for each. We enrolled a total of 420 children (227 KD and 193 sepsis) in this study. Logistic regression and a nomogram model were used to analyze the laboratory markers. We randomly selected 247 children as the training modeling group and 173 as the validation group. After completing a logistic regression analysis, white blood cell (WBC), anemia, procalcitonin (PCT), C-reactive protein (CRP), albumin, and alanine transaminase (ALT) demonstrated a significant difference in differentiating KD from sepsis. The patients were scored according to the nomogram, and patients with scores greater than 175 were placed in the high-risk KD group. The area under the curve of the receiver operating characteristic curve (ROC curve) of the modeling group was 0.873, sensitivity was 0.893, and specificity was 0.746, and the ROC curve in the validation group was 0.831, sensitivity was 0.709, and specificity was 0.795. A novel nomogram prediction model may help clinicians differentiate KD from sepsis with high accuracy.

Reference-Based Integral MR-EPT:Simulation and Experiment Studies on the 9.4T MRI.

Current integral-equation (IE) based MR electrical properties tomography (EPT) methods utilize simulated incident radio-frequency (RF) fields, which are inaccurate and lead to reconstruction errors. To improve the accuracy and practicability of IE-based MR-EPT methods, a new approach is presented that obtains the incident fields using reference subjects and RF field mapping techniques. The Incident field approximation (IFA) is first demonstrated in this paper. This approximation assumes that two imaged subjects with similar coil/subject interactions will have similar incident RF fields, thus one can feed the estimation of the incident fields within the imaged subject into the calculation of those within a homogeneous subject (reference subject). This is done by measuring the total RF fields ( field) of the reference using field mapping techniques, using the known EPs of the reference subject and by rearranging Ampere's Law and the integral equations. The calculated incident RF fields are then used to reconstruct the EPs' distribution with a three-dimensional (3D) integral-based MR-EPT method. Numerical simulation results indicated that the incident RF fields obtained from the reference subject provide accurate 3D reconstruction of EPs with less than 16% root mean square error (RMSE) in noise-free scenario while the conventional IE method had more than 28% RMSE. The phantom-based experiments at 9.4T MRI system have also been conducted to evaluate the performance of the proposed method and the results indicated that the proposed method achieved desirable robustness against the noise in practical scenario with less than 21% RMSE while the conventional differential equation-based method showed worse than 37% RMSE.

Risk of acute coronary syndrome after parathyroidectomy in patients with end-stage renal disease: A population-based cohort study in Taiwan.

AIM: Patients with end-stage renal disease (ESRD) who received parathyroidectomy (PTX) had persistently reduced levels of parathyroid hormone. This study investigated the risk of acute coronary syndrome (ACS) in patients with ESRD who underwent PTX using a nationwide health insurance claims database. METHODS: Of all ESRD patients, we selected 1047 individuals who had undergone PTX between 2000 and 2008 as the PTX group and 4188 patients who did not undergo PTX (non-PTX group) matched by propensity score. Multivariable Cox proportional hazards regression analysis was conducted for assessing the excess ACS risk for the PTX group compared to the non-PTX group. RESULTS: The mean follow-up periods were 4.63 and 4.04 years for the PTX and non-PTX groups, respectively. A significant reduction in the risk of ACS (adjusted hazard ratio = 0.74, 95% confidence interval = 0.57-0.96) was observed for the ESRD patients after PTX. CONCLUSIONS: Parathyroidectomy is associated with reduced risk of ACS in patients with ESRD.

Curcumin Acetate Nanocrystals for sustained Pulmonary Delivery: Preparation, Characterization and In Vivo Evaluation.

The main objective of this study was to test the hypothesis that inhaled nanocrystals of a highly lipophilic drug could be used as a novel approach for producing sustained pulmonary delivery. Curcumin acetate, an ester prodrug of curcumin, was utilized as a highly lipophilic model drug. Curcumin acetate was subjected to wet ball milling to produce different particle sizes of nanocrystals and microparticles, and the milled curcumin acetate was spray-dried to yield similar inhalable microparticles. Following intrapulmonary administration in rats, pharmacokinetic experiments indicated that curcumin acetate significantly extended the pulmonary absorption time by 7.2-fold compared to curcumin, possibly due to the high lipophilicity of the former. The biodistribution data showed that aerosolized curcumin acetate nanocrystals 123.7 nm in size not only prolonged pulmonary retention, with the AUC value of curcumin acetate being 7.62-fold higher than that of the microparticles 1120 nm in size, but also increased the local in vivo release rate by 3.3-fold and the local availability of converted curcumin by 25.1-fold. In addition, the improved local availability resulted in better pharmacological efficacy in a monocrotaline-induced rat model of pulmonary arterial hypertension. This study was the first to demonstrate that inhalable nanocrystals are a feasible means for the sustained pulmonary delivery of highly lipophilic drugs.

Ezrin/Exocyst complex regulates mucin 5AC secretion induced by neutrophil elastase in human airway epithelial cells.

BACKGROUND/AIM: Increased mucin secretion is a characteristic feature of many chronic airway diseases, particularly during periods of exacerbation; however, the exact mechanism of mucin secretion remains unclear. Ezrin, which is a specific marker of apical membranes, is predominantly concentrated in exocyst-rich cell surface structures, crosslinking the actin cytoskeleton with the plasma membrane. In the present study, we examined whether Ezrin is involved in mucin 5AC (MUC5AC) secretion after neutrophil elastase (NE) attack, and we investigated the role of the exocyst complex docking protein Sec3 in this process. METHODS: NE was used as a stimulator in a 16HBE14o- cell culture model. The expression and location of Ezrin and Sec3 were investigated, and the interaction between Ezrin and Sec3 in 16HBE14o-cells was assayed after treatment with NE, Ezrin siRNA, Sec3 siRNA, neomycin or PIP2-Ab. RESULTS: We found that Ezrin was highly expressed in the bronchi of humans with chronic airway diseases. NE induced robust MUC5AC protein secretion. The Ezrin siRNA, Sec3 siRNA, and neomycin treatments led to impaired MUC5AC secretion in cells. Both Ezrin and Sec3 were recruited primarily to the cytoplasmic membrane after NE stimulation, and the neomycin and PIP2-Ab treatments abrogated this effect. Immunoprecipitation analysis revealed that Ezrin and Sec3 combined to form complexes; however, these complexes could not be detected in Ezrin∆1-333 mutant-transfected cells, even when PIP2 was added. CONCLUSIONS: These results demonstrate that Ezrin/Sec3 complexes are essential for MUC5AC secretion in NE-stimulated airway epithelial cells and that PIP2 is of critical importance in the formation of these complexes.

Hepatitis C virus infection increases the risk of developing peripheral arterial disease: a 9-year population-based cohort study.

BACKGROUND & AIMS: The relationship between hepatitis C virus (HCV) infection and peripheral arterial disease (PAD) development remains unclear. METHODS: Health insurance claims data were used to construct a cohort of HCV-infected patients diagnosed during the period 1998-2011. Patients younger than 20 years and those with history of hepatitis B or PAD were excluded. We selected 7641 HCV-infected patients and 30564 matched controls. The adjusted risk of developing PAD was analyzed using a multivariate Cox hazard model. RESULTS: The results show that the excess risk of PAD development in HCV-infected patients is 1.43-fold higher (95% CI=1.23-1.67) compared with non-HCV patients. The adjusted risk of PAD development increases with age; compared with the 20-34 year-old patients, the risk is 3.96-fold higher in HCV-infected patients aged 35-49 years, and 11.7-fold higher in those aged 65 years and above. CKD/ESRD has the highest risk for PAD (HR=1.80, 95% CI=1.29-2.53). HCV-infected patients with four comorbidities exhibit a substantially higher risk of developing PAD (HR=9.25, 95% CI=6.35-13.5). Excess risk of developing PAD is observed from the first year of follow-up till the third year. CONCLUSION: HCV-infected patients have an independently higher risk of developing PAD. HCV-infected patients with comorbidity have increased risk of developing PAD.

Characteristics, survival, and related factors of newly diagnosed colorectal cancer patients refusing cancer treatments under a universal health insurance program.

BACKGROUND: Colorectal cancer is the third most commonly diagnosed cancer worldwide. Few studies have addressed the causes and risks of treatment refusal in a universal health insurance setting. METHODS: We examined the characteristics and survival associated with treatment refusal in patients with newly diagnosed colorectal cancer in Taiwan during 2004-2008. Treatment refusal was defined as not undergoing any cancer treatment within 4 months of confirmed cancer diagnosis. Patient data were extracted from four national databases. Factors associated with treatment refusal were identified through logistic regression using the generalized estimating equation method, and survival analysis was performed using the Cox proportional hazards model. RESULTS: Of the 41,340 new colorectal cancer cases diagnosed, 3,612 patients (8.74%) refused treatment. Treatment refusal rate was higher in patients with less urbanized areas of residence, lower incomes, preexisting catastrophic illnesses, cancer stages of 0 and IV, and diagnoses at regional and district hospitals. Logistic regression analysis revealed that patients aged >75 years were the most likely to refuse treatment (OR, 1.87); patients with catastrophic illnesses (OR, 1.66) and stage IV cancer (OR, 1.43) had significantly higher refusal rates. The treatment refusers had 2.66 times the risk of death of those who received treatment. Factors associated with an increased risk of death in refusers included age ≥ 75 years, insured monthly salary ≥ 22,801 NTD, low-income household or aboriginal status, and advanced cancer stage (especially stage IV; HR, 11.33). CONCLUSION: Our results show a lower 5-year survival for colorectal patients who refused treatment than for those who underwent treatment within 4 months. An age of 75 years or older, low-income household status, advanced stages of cancer, especially stage IV, were associated with higher risks of death for those who refused treatment.

Section 9. Technical details of microsurgical biliary reconstruction in living donor liver transplantation.

Small size and multiple ducts, particularly in right lobe liver grafts, are major factors that contribute to biliary complications in living donor liver transplantation. To improve the outcome of biliary reconstruction, further investigation and refinement of reconstruction techniques and management strategies are necessary. From March 2006 to June 2012, routine MBR was performed in 584 grafts in 581 consecutive LDLT (including 3 dual graft transplants). All biliary reconstructions were performed using microsurgical technique by a single microsurgeon. The classification of biliary reconstruction was based according to the number of ducts in the graft, the manner in which these ducts were reconstructed (with or without ductoplasty), and the conduit used (recipient duct or jejunum) to reconstruct the biliary tree. In duct-to-duct reconstruction, posterior wall first technique by using interrupted suture and continuous running and interrupted tie technique (combined method) for the anterior wall were performed. Recipient reduction ductoplasty was done, if necessary. In duct-to-jejunum reconstruction, enterotomy was performed first under microscope; then, the serosal and mucosal layers were sutured together using 8-0 prolene to facilitate the anastomosis. Posterior wall first by using interrupted suture technique and combined method for the anterior wall were also performed. Overall, there were 397 right and 184 left lobe grafts. Single duct opening was noted in 440 (75.34%), two duct openings in 135(23.12%), and three duct openings in 9 (1.54%) grafts. Duct-to-duct anastomosis was performed in 473 (81%) and duct-to-jejunum Roux limb in 111 (19%) biliary reconstructions. Size discrepancy in the graft and recipient ducts was noted in 394 (83.3%) reconstructions. The overall biliary complication was 7.9%. These included 19 (3.3%) bile leaks and 27 (4.6%) biliary strictures. The routine use of MBR capably surmounts the difficulties brought about by the anatomic variations and the size discrepancies between the graft and recipient hepatic ducts with excellent outcome.

Early and long-term results of routine microsurgical biliary reconstruction in living donor liver transplantation.

We describe our early and long-term experience with routine biliary reconstruction via a microsurgical technique in living donor liver transplantation (LDLT). One hundred seventy-seven grafts (including 3 dual grafts) were primarily transplanted into 174 recipients. The minimum follow-up was 44 months. Biliary reconstructions were based on biliary anatomical variations in graft and recipient ducts. The recipient demographics, graft characteristics, types of biliary reconstruction, biliary complications (BCs), and outcomes were evaluated. There were 130 right lobe grafts and 47 left lobe grafts. There were single ducts in 71.8%, 2 ducts in 26.0%, and 3 ducts in 2.3% of the grafts. The complications were not significantly related to the size and number of ducts, the discrepancy between recipient and donor ducts, the recipient age, the ischemia time, or the type of graft. The overall BC rate was 9.6%. The majority of the complications occurred within the first year, and only 1 patient developed a stricture at 20 months. No new complications were noted after 2 years. When the learning-curve phase of the first 15 cases was excluded, the overall BC rate was 6.79%, and the rate of complications requiring interventions was 2.5%. In conclusion, the routine use of microsurgical biliary reconstruction decreases the number of early and long-term anastomotic BCs in LDLT.

All-in-one sleeve patch graft venoplasty for multiple hepatic vein reconstruction in living donor liver transplantation.

OBJECTIVES: This paper presents an innovative technique to address complex multiple hepatic vein (HV) reconstruction in right lobe graft living donor liver transplantation (RL-LDLT). METHODS: A patient with hepatitis C virus-related cirrhosis underwent RL-LDLT. The graft had seven HVs, including: the right HV (17 mm); one segment VII HV (11 mm); two segment VI HVs (6 mm and 16 mm), and three segment V HVs. The graft weighed 663 g (53% of standard liver volume; ratio of graft weight to recipient body weight: 0.96). Each HV had significant drainage territory requiring reconstruction. A cryopreserved iliac vein graft was used to create a sleeve patch to incorporate the HV openings. The holes were anastomosed to their corresponding HV tributaries using continuous 6-0 polydioxanone (PDS) sutures. Two of the three segment V HVs were combined using a smaller iliac vein patch, which was anastomosed in an end-to-side fashion to a previously harvested recipient umbilical vein interposition graft. The other end of the umbilical vein graft was anastomosed to the larger iliac vein sleeve patch. RESULTS: Overall, six HV openings were incorporated in one sleeve patch to allow a single wide anastomosis with the recipient inferior vena cava. Doppler ultrasound after reconstruction showed adequate flow patterns in all the HVs. CONCLUSIONS: All-in-one sleeve patch graft venoplasty simplifies the reconstruction of multiple HVs and reduces warm ischaemia time in RL-LDLT with excellent outcomes.

An ordered Si nanowire with NiSi2 tip arrays as excellent field emitters.

A method was developed to grow ordered silicon nanowire with NiSi(2) tip arrays by reacting nickel thin films on silica-coated ordered Si nanowire (NW) arrays. The coating of thin silica shell on Si NW arrays has the effect of limiting the diffusion of nickel during the silicidation process to achieve the single crystalline NiSi(2) NWs. In the meantime, it relieves the distortion of the NWs caused by the strain associated with formation of NiSi(2) to maintain the straightness of the nanowire and the ordering of the arrays. Other nickel silicide phases such as Ni(2)Si and NiSi were obtained if the silicidation processes were conducted on the ordered Si NWs without a thin silica shell. Excellent field emission properties were found for NiSi(2)/Si NW arrays with a turn on field of 0.82 V µm(-1) and a threshold field of 1.39 V µm(-1). The field enhancement factor was calculated to be about 2440. The stability test showed a fluctuation of about 7% with an applied field of 2.6 V µm(-1) for a period of 24 h. The excellent field emission characteristics are attributed to the well-aligned and highly ordered arrangement of the single crystalline NiSi(2)/Si heterostructure field emitters. In contrast to other growth methods, the present growth of ordered nickel silicide/Si NWs on silicon is compatible with silicon nanoelectronics device processes, and also provides a facile route to grow other well-aligned metal silicide NW arrays. The advantages will facilitate its applications as field emission devices.

Role of reactive oxygen species-elicited apoptosis in the pathophysiology of mitochondrial and neurodegenerative diseases associated with mitochondrial DNA mutations.

A wide spectrum of pathogenic mutations of mitochondrial DNA (mtDNA) has been demonstrated to cause mitochondrial dysfunction and overproduction of reactive oxygen species (ROS), in relation to mitochondrial and neurodegenerative diseases. Our previous studies have shown that large-scale deletions of mtDNA not only serve as an indicator of oxidative damage, but also result in greater susceptibility of human cells to apoptosis triggered by UV irradiation and other apoptotic stimuli. In this review, we focus on the involvement of mtDNA-mutation-associated oxidative stress and susceptibility to apoptosis in the pathophysiology of mitochondrial and neurodegenerative diseases. Different lines of research have provided concordant data to suggest that the mtDNA-mutation-elicited energy insufficiency and enhanced oxidative stress and damage lead to cell dysfunction, and increase the susceptibility of affected cells to apoptosis in patients with these diseases. Moreover, accumulating experimental evidence has shown that antioxidant therapy is a good strategy for decreasing intracellular ROS and alleviating oxidative-stress-induced apoptosis in cells of patients that harbor pathogenic mtDNA mutations.

Activation of PKCdelta and ERK1/2 in the sensitivity to UV-induced apoptosis of human cells harboring 4977 bp deletion of mitochondrial DNA.

The 4977 bp deletion of mitochondrial DNA (mtDNA), often found in patients with chronic progressive external ophthalmoplegia (CPEO), has been demonstrated to increase the susceptibility to apoptosis of human cells. We investigated the mechanism underlying the apoptotic susceptibility of the Delta4977 cybrid harboring about 80% 4977 bp-deleted mtDNA. The production of hydrogen peroxide (H(2)O(2)) and phosphorylation of PKCdelta and ERK1/2 were increased in the Delta4977 cybrid, which was more susceptible to UV-induced apoptosis. Moreover, treatment with N-acetyl-l-cysteine (NAC) or blocking of activation of PKCdelta by rottlerin or PKCdelta-siRNA, and inhibition of ERK1/2 by PD98059 or ERK1/2-siRNA significantly attenuated the susceptibility of the Delta4977 cybrid to apoptosis. Furthermore, the increase of PKCdelta expression in the Delta4977 cybrid also amplified the apoptotic signal through caspase 3-mediated proteolytic activation of PKCdelta. In addition, PKCdelta and ERK1/2 were hyperphosphorylated in skin fibroblasts of CPEO patients harboring 4977 bp-deleted mtDNA. We suggest that the activation of PKCdelta and ERK1/2 elicited by 4977 bp-deleted mtDNA-induced oxidative stress plays a role in the susceptibility of the mutant cells to apoptosis. This may explain, at least in part, the degenerative manifestation of brain and muscle in patients with mitochondrial encephalomyopathies such as CPEO syndrome.