Physicochemical properties and structural changes of chicken breast meat subjected to radio frequency tempering combined with conventional thawing treatments

Being able to thaw frozen meat in a reasonable time without impairing quality is crucial for industry and households. Radio frequency (RF) techniques have been used to defrost frozen foods. The influences of RF (50 kW, 27.12 MHz) tempering combined with water immersion (WI, 20°C) thawing (RFWI) or air convection (AC, 20°C) thawing (RFAC) on the physicochemical and structural changes of chicken breast meat were investigated, and the results were compared with those of the fresh meat (FM) and the meat samples subjected to WI and AC only. The thawing processes were terminated when the core temperatures of the samples reached 4°C. The results indicated that AC was the most time-consuming technique, whereas RFWI required the least amount of time. The moisture losses, contents of the thiobarbituric acid-reactive substance, total volatile basic nitrogen, and total viable counts of the meat subjected to AC were higher. Relatively less changes in water-holding capacity, coloration, oxidation, microstructure, protein solubility, and high sensorial acceptance were observed for RFWI and RFAC. This study demonstrated that the meat thawed using RFWI and RFAC was of satisfactory quality. Therefore, the RF techniques can be effective alternatives to the time-consuming conventional thawing methods and benefit the meat industry.

Association of leukocyte mitochondrial DNA copy number with longitudinal C-reactive protein levels and survival in older adults: a cohort study

BACKGROUND

Systemic chronic inflammation occurs with age. The association of the leukocyte mitochondrial DNA copy number, a measure of mitochondrial function in aging, with the temporal profile of serum high-sensitivity C-reactive protein and mortality risk remains uncertain. The objectives of this study were to examine the association of the leukocyte mitochondrial DNA copy number with longitudinal high-sensitivity C-reactive protein levels and the association of the longitudinal high-sensitivity C-reactive protein levels with mortality risk.

METHODS

This prospective cohort study included 3928 adults aged ≥ 55 years without systemic inflammation in the baseline examination of the Healthy Aging Longitudinal Study in Taiwan, which started in 2009. Each participant received leukocyte mitochondrial DNA copy number measurement using a fluorescence-based quantitative polymerase chain reaction at baseline, serum high-sensitivity C-reactive protein measurements at baseline and the follow-up examination five years later, and the ascertainment of all-cause death (until November 30, 2021). The relationships among the leukocyte mitochondrial DNA copy number, longitudinal serum high-sensitivity C-reactive protein levels, and time to all-cause mortality were examined using the joint longitudinal and survival modeling analysis.

RESULTS

Of the 3928 participants (mean age: 69 years; 2060 [52%] were women), 837 (21%) died during follow-up. In the adjusted analysis, one standard deviation lower natural log-transformed baseline leukocyte mitochondrial DNA copy number was associated with an increase of 0.05 (95% confidence interval [CI], 0.02 to 0.08) standard deviation in serum high-sensitivity C-reactive protein in subsequent years. An increase of 1 standard deviation in instantaneous high-sensitivity C-reactive protein levels was associated with a hazard ratio (HR) for all-cause mortality of 1.22 (95% CI, 1.14 to 1.30). Similar results were obtained after further adjusting for baseline high-sensitivity C-reactive protein levels (HR [95% CI], 1.27 [1.16 to 1.38]) and after excluding those with serum high-sensitivity C-reactive protein above 10 mg/L (HR [95% CI], 1.21[1.11 to 1.31]) or 3 mg/L (HR [95% CI], 1.19 [1.06 to 1.31]) during follow-up.

CONCLUSIONS

A lower leukocyte mitochondrial DNA copy number was associated with persistently higher high-sensitivity C-reactive protein levels. Moreover, these higher time-varying high-sensitivity C-reactive protein levels were instantaneously associated with a higher risk of death.

Regulation of mitochondrial fusion and mitophagy by intra-tumoral delivery of membrane-fused mitochondria or Midiv-1 enhances sensitivity to doxorubicin in triple-negative breast cancer

Increasing mitochondrial fusion by intra-tumoral grafting of membrane-fused mitochondria created with Pep-1 conjugation (P-Mito) contributes to breast cancer treatment, but it needs to be validated. Using mitochondrial division inhibitor-1 (Mdivi-1, Mdi) to disturb mitochondrial dynamics, we showed that the antitumor action of P-Mito in a mouse model of triple-negative breast cancer depends upon mitochondrial fusion and that Mdi treatment alone is ineffective. P-Mito significantly enhanced Doxorubicin (Dox) sensitivity by inducing mitochondrial fusion and mitophagy, and the same efficiency was also achieved with Mdi by inhibiting mitophagy. Cell death was induced via the p53 pathway and AIF nuclear translocation in the case of P-Mito, versus the caspase-dependent pathway for Mdi. Notably, both mitochondrial treatments reduced oxidative stress and blood vessel density of xenograft tumors, especially P-Mito, which was accompanied by inhibition of nuclear factor kappa-B activation. Furthermore, through enrichment analysis, four microRNAs in serum microvesicles induced by P-Mito caused expression of predicted targets via the PI3K-Akt pathway, and significantly impacted regulation of nuclear processes and myeloid cell differentiation. Clustering of gene-sets implicated a major steroid catabolic network. This study showed diverse roles of mitochondria in breast cancer and revealed effective adjuvant therapy targeting mitochondrial fusion and mitophagy.

Coenzyme Q10 Supplementation Increases Removal of the ATXN3 Polyglutamine Repeat, Reducing Cerebellar Degeneration and Improving Motor Dysfunction in Murine Spinocerebellar Ataxia Type 3

Coenzyme Q10 (CoQ10), a well-known antioxidant, has been explored as a treatment in several neurodegenerative diseases, but its utility in spinocerebellar ataxia type 3 (SCA3) has not been explored. Herein, the protective effect of CoQ10 was examined using a transgenic mouse model of SCA3 onset. These results demonstrated that a diet supplemented with CoQ10 significantly improved murine locomotion, revealed by rotarod and open-field tests, compared with untreated controls. Additionally, a histological analysis showed the stratification of cerebellar layers indistinguishable from that of wild-type littermates. The increased survival of Purkinje cells was reflected by the reduced abundance of TUNEL-positive nuclei and apoptosis markers of activated p53, as well as lower levels of cleaved caspase 3 and cleaved poly-ADP-ribose polymerase. CoQ10 effects were related to the facilitation of the autophagy-mediated clearance of mutant ataxin-3 protein, as evidenced by the increased expression of heat shock protein 27 and autophagic markers p62, Beclin-1 and LC3II. The expression of antioxidant enzymes heme oxygenase 1 (HO-1), glutathione peroxidase 1 (GPx1) and superoxide dismutase 1 (SOD1) and 2 (SOD2), but not of glutathione peroxidase 2 (GPx2), were restored in 84Q SCA3 mice treated with CoQ10 to levels even higher than those measured in wild-type control mice. Furthermore, CoQ10 treatment also prevented skeletal muscle weight loss and muscle atrophy in diseased mice, revealed by significantly increased muscle fiber area and upregulated muscle protein synthesis pathways. In summary, our results demonstrated biochemical and pharmacological bases for the possible use of CoQ10 in SCA3 therapy.

Transcriptomic and Metabolic Network Analysis of Metabolic Reprogramming and IGF-1 Modulation in SCA3 Transgenic Mice

Spinocerebellar ataxia type 3 (SCA3) is a genetic neurodegenerative disease for which a cure is still needed. Growth hormone (GH) therapy has shown positive effects on the exercise behavior of mice with cerebellar atrophy, retains more Purkinje cells, and exhibits less DNA damage after GH intervention. Insulin-like growth factor 1 (IGF-1) is the downstream mediator of GH that participates in signaling and metabolic regulation for cell growth and modulation pathways, including SCA3-affected pathways. However, the underlying therapeutic mechanisms of GH or IGF-1 in SCA3 are not fully understood. In the present study, tissue-specific genome-scale metabolic network models for SCA3 transgenic mice were proposed based on RNA-seq. An integrative transcriptomic and metabolic network analysis of a SCA3 transgenic mouse model revealed that metabolic signaling pathways were activated to compensate for the metabolic remodeling caused by SCA3 genetic modifications. The effect of IGF-1 intervention on the pathology and balance of SCA3 disease was also explored. IGF-1 has been shown to invoke signaling pathways and improve mitochondrial function and glycolysis pathways to restore cellular functions. As one of the downregulated factors in SCA3 transgenic mice, IGF-1 could be a potential biomarker and therapeutic target.

Intranasal delivery of mitochondria for treatment of Parkinson's Disease model rats lesioned with 6-hydroxydopamine

The feasibility of delivering mitochondria intranasally so as to bypass the blood-brain barrier in treating Parkinson's disease (PD), was evaluated in unilaterally 6-OHDA-lesioned rats. Intranasal infusion of allogeneic mitochondria conjugated with Pep-1 (P-Mito) or unconjugated (Mito) was performed once a week on the ipsilateral sides of lesioned brains for three months. A significant improvement of rotational and locomotor behaviors in PD rats was observed in both mitochondrial groups, compared to sham or Pep-1-only groups. Dopaminergic (DA) neuron survival and recovery > 60% occurred in lesions of the substantia nigra (SN) and striatum in Mito and P-Mito rats. The treatment effect was stronger in the P-Mito group than the Mito group, but the difference was insignificant. This recovery was associated with restoration of mitochondrial function and attenuation of oxidative damage in lesioned SN. Notably, P-Mito suppressed plasma levels of inflammatory cytokines. Mitochondria penetrated the accessory olfactory bulb and doublecortin-positive neurons of the rostral migratory stream (RMS) on the ipsilateral sides of lesions and were expressed in striatal, but not SN DA neurons, of both cerebral hemispheres, evidently via commissural fibers. This study shows promise for intranasal delivery of mitochondria, confirming mitochondrial internalization and migration via RMS neurons in the olfactory bulb for PD therapy.

[Effect of levothyroxine treatment on pregnancy outcomes in euthyroid women with thyroid autoantibody positive: a Meta-analysis]

Objective: To conduct a systematic review of the association of levothyroxine treatment with pregnancy outcomes in euthyroid women who are thyroid autoantibody positive. Methods: Medline, Excerpta Medica (EMBASE), Cochrane Library, China National Knowledge Infrastructure (CNKI), China Biology Medicine (CBM), Wanfang data and VIP database were searched from inception until Jan. 28, 2020. All published randomized controlled trials assessing the association of levothyroxine treatment with pregnancy outcomes in euthyroid women with thyroid autoantibody-positive were included. STATA 11.0 and RevMan 5.3 softwares were used to perform this Meta-analysis. Results: A total of 6 studies met the inclusion criteria, with 2 188 women randomized. Meta-analysis showed that there was no significantly association between miscarriage (OR=0.85, 95%CI: 0.65-1.11, P=0.234) and preterm birth (OR=0.79, 95%CI: 0.54-1.16, P=0.224) with levothyroxine treatment. Conclusions: Levothyroxine therapy could not reduce the risk of miscarriage and preterm birth in euthyroid women with thyroid autoantibody-positive. Therefore, levothyroxine should be used with caution for these pregnant women.

Antitumor Actions of Intratumoral Delivery of Membrane-Fused Mitochondria in a Mouse Model of Triple-Negative Breast Cancers

Background

The transfer of whole mitochondria has been demonstrated to be beneficial for treating breast cancer because it induces apoptosis and drug sensitivity; however, in vivo evidence of this benefit remains scant. The present study compared the transplantation of mitochondria with instinctive (Mito) and membrane-fused morphologies induced by Pep-1 conjugation (P-Mito) using a mouse model of triple-negative breast cancers.

Materials and Methods

Mice with advanced severe immunodeficiency received orthotopic implantation of MDA-MB-231 human breast cancer cells followed by transplants of 5-bromo-2'-deoxyuridine (BrdU)-labeled Mito or P-Mito (200 μg [10 μg/μL]) through intratumoral injection at multiple points once a week for 4 weeks.

Results

After 1 month of consecutive treatment, 8.2% and 14.2% of the BrdU-labeled mitochondria were preserved in tumors of the Mito and P-Mito groups, respectively. Both Pep-1 and P-Mito treatments reduced tumor weight (21.7% ± 2.43% vs 40.6% ± 2.28%) and led to marked inhibition of Ki67 staining and angiogenesis. However, only the P-Mito group exhibited obvious necrosis and DNA fragmentation accompanied by an altered tumor microenvironment, which included reduced oxidative stress and size of cancer-associated fibroblast populations and enhanced immune cell infiltration. Transmission electron microscopy images further revealed an elongated network of perinuclear mitochondria fused with a few peripheral mitochondria in the nonnecrotic area in the P-Mito group as well as increases in mitochondrial fusion proteins and parkin compared with mitochondrial fission proteins.

Conclusion

In this study, the results of mitochondrial transplantation emphasized that the facilitation of mitochondrial fusion is a critical regulator in breast cancer therapy.

Treadmill training increases the motor activity and neuron survival of the cerebellum in a mouse model of spinocerebellar ataxia type 1

Spinocerebellar ataxia (SCA) type 1 (SCA1) is a rare autosomal dominant disorder that is characterized by worsening of disordered coordination, ataxia of the trunk, and other neurological symptoms. Physical activity improves both mobility and the daily living activities of patients with SCA. Intervention with daily regular treadmill exercise may slow the deterioration of cerebellar neurons in SCA1. Therefore, the signal changes and performance of cerebellar neurons after exercise in SCA1 was investigated in this study. We employed a transgenic mouse model of SCA1, generated by amplifying the cytosine-adenine-guanine trinucleotide repeat expansions, and the mice underwent 1 month of moderate daily treadmill exercise for 1 hour. The rotarod test revealed that the motor function of the SCA1 mice that underwent training was superior to that of the control SCA1 mice, which did not undergo training. Moreover, the cerebellar pathology revealed preserved Purkinje neurons stained by carbindin with an increase of the neuronal Per Arnt Sim domain protein 4, a key regulation in the structural and functional plasticity of neurons, in the excised SCA1 mice relative to the controls. The mechanism was related to an increase of phosphorylation of ribosomal protein S6, a downstream target of the mammalian target of rapamycin pathway, but not to autophagy activation. This study determined that regular treadmill exercise may play a crucial role in the viable support of cerebellar neurons in SCA1.

Mitochondrial transplantation regulates antitumour activity, chemoresistance and mitochondrial dynamics in breast cancer

Background

The transfer of whole mitochondria that occurs during cell contact has been found to support cancer progression. However, the regulatory role of mitochondria alone is difficult to elucidate due to the complex microenvironment. Currently, mitochondrial transplantation is an available approach for restoring mitochondrial function in mitochondrial diseases but remains unclear in breast cancer. Herein, effects of mitochondrial transplantation via different approaches in breast cancer were investigated.

Methods

Whole mitochondria (approximately 10.5 μg/ml) were transported into MCF-7 breast cancer cells via passive uptake or Pep-1-mediated delivery. Fresh mitochondria isolated from homeoplasmic 143B osteosarcoma cybrids containing mitochondrial DNA (mtDNA) derived from health individuals (Mito) or mtDNA with the A8344G mutation (Mito⁸³⁴⁴) were conjugated with cell-penetrating peptide Pep-1 (P-Mito) or not conjugated prior to cell co-culture. Before isolation, mitochondria were stained with MitoTracker dye as the tracking label. After 3 days of treatment, cell viability, proliferation, oxidative stress, drug sensitivity to Doxorubicin/Paclitaxel and mitochondrial function were assessed.

Results

Compared with P-Mito, a small portion of Mito adhered to the cell membrane, and this was accompanied by a slightly lower fluorescent signal by foreign mitochondria in MCF-7 cells. Both transplantations induced cell apoptosis by increasing the nuclear translocation of apoptosis-inducing factor; inhibited cell growth and decreased oxidative stress in MCF-7 cells; and increased the cellular susceptibility of both the MCF-7 and MDA-MB-231 cell lines to Doxorubicin and Paclitaxel. Mitochondrial transplantation also consistently decreased Drp-1, which resulted in an enhancement of the tubular mitochondrial network, but a distinct machinery through the increase of parkin and mitochondrial fusion proteins was observed in the Mito and P-Mito groups, respectively. Furthermore, although there were no differences in energy metabolism after transplantation of normal mitochondria, metabolism was switched to the energetic and glycolytic phenotypes when the mitochondria were replaced with dysfunctional mitochondria, namely, Mito⁸³⁴⁴ and P-Mito⁸³⁴⁴, due to dramatically induced glycolysis and reduced mitochondrial respiration, respectively. Consequently, transplant-induced growth inhibition was abolished, and cell growth in the Mito⁸³⁴⁴ group was even higher than that in the control group.

Conclusion

This study reveals the antitumour potential of mitochondrial transplantation in breast cancer via distinct regulation of mitochondrial function.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1028-z) contains supplementary material, which is available to authorized users.

Aminoglycoside-associated nonsyndromic deafness and speech disorder in mitochondrial A1555G mutation in a family: A case report

RATIONALE

Mitochondrial DNA mutations have been associated with many maternal inherited diseases. A1555G mutation in mtDNA effects the gene code for rRNA, resulting in the structural change of human ribosome rending it susceptible to binding of the common antibiotic, aminoglycosides. Such mutation has linked with non-syndromic hearing loss and is one of the most common mtDNA mutations in Asian populations.

PATIENT CONCERNS

A 50-year-old Taiwanese female visited our neurology department with concern for multiple members with hearing loss in her family, including herself.

DIAGNOSES

Physical examination findings were not significant besides hearing loss and brain MRI did not reveal any lesions. BAEP confirmed bilateral peripheral sensory deficit. Given the multiple cases of hearing loss in the family, a genetic cause was suspected. Using PCR and sequences chromatogram technique we have identified A1555G mutation on her mtDNA affecting region codes for 12S rRNA. Additionally, we observed severe speech disorder in two young family members with the onset of hearing loss began in their early childhood.

INTERVENTIONS

The patient declined any form of intervention at the time for personal reasons.

OUTCOMES

The patient was satisfied with the diagnosis, her and her families are continuously followed by our neurology department.

LESSONS

We report on a family with mtDNA mutation hearing loss that is related to exposure to aminoglycosides. Children with such mutation are at high risk for impaired linguistic function. Early identification and intervention with cochlear implant should be considered.

Dysphagia with fatal choking in oculopharyngeal muscular dystrophy: Case report

RATIONALE

Oculopharyngeal muscular dystrophy (OPMD) is an autosomal dominant late-onset progressive muscle disorder typically characterized by ptosis, difficulty in swallowing, and proximal limb weakness. Underdiagnosis of OPMD is common in Asian countries and results in delayed diagnoses and fatal events.

PATIENT CONCERNS

Here, we report the case of a 53-year-old female who suffered from progressive dysphagia and experienced several choking events involving solid material. An extensive family history of dysphagia was noted, and 2 family members had died as a result of aspiration.

DIAGNOSES

PABPN1 genotyping and DNA sequence analysis revealed a heterozygous (GCG)10(GCA)3GCG mutation that led to the diagnosis of OPMD.

INTERVENTIONS

Rehabilitation exercises, namely, the Shaker exercise and the Masako maneuver, were suggested.

OUTCOMES

Improved swallowing ability with safe food intake was noted after 2 months of training. Surgical intervention will be considered when progression of the disease is noted.

LESSONS

Underdiagnosis and a lack of awareness of OPMD may lead to choking, aspiration pneumonia, and death in multiple members of affected families. Currently, there is no definitive treatment for OPMD, but rehabilitation exercises and surgical intervention are helpful in relieving dysphagia.

Personal exposure to fine particulate matter and benzo[a]pyrene from indoor air pollution and leukocyte mitochondrial DNA copy number in rural China

Households in Xuanwei and Fuyuan, China, possess hazardous levels of fine particulate matter with an aerodynamic diameter <2.5 microns (PM2.5) and polycyclic aromatic hydrocarbons (PAHs) from coal combustion. Previous studies found that increased exposure to PM2.5 and benzo[a]pyrene (BaP; a PAH) were associated with decreased mitochondrial DNA copy number (mtDNAcn), a marker of oxidative stress. We further evaluated these associations in a cross-sectional study of 148 healthy non-smoking women from Xuanwei and Fuyuan. Personal exposure to PM2.5 and BaP was measured using portable devices. MtDNAcn was measured using qPCR amplification of leukocyte DNA that was collected after air measurements. Linear regression models were used to estimate the associations between personal exposure to PM2.5 and BaP, and mtDNAcn adjusted for age, body mass index (BMI) and fuel type. We found inverse associations between exposure to PM2.5 and BaP, and mtDNAcn. Each incremental log-μg/m3 increase in PM2.5 was associated with a significant decrease in mtDNAcn of -10.3 copies per cell [95% confidence interval (95% CI): -18.6, -2.0; P = 0.02]. Additionally, each log-ng/m3 increase in BaP was associated with a significant decrease in mtDNAcn of -5.4 copies per cell (95% CI: -9.9, -0.8, P = 0.02). Age, BMI, fuel type and coal mine type were not significantly associated with mtDNAcn. Exposure to PM2.5 and BaP may alter mitochondrial dynamics in non-smoking Chinese women. MtDNAcn may be a potential mediator of indoor air pollution on chronic disease development.

Correction: Systematic investigation of the SERS efficiency and SERS hotspots in gas-phase deposited Ag nanoparticle assemblies

Correction for 'Systematic investigation of the SERS efficiency and SERS hotspots in gas-phase deposited Ag nanoparticle assemblies' by L. B. He et al., Phys. Chem. Chem. Phys., 2017, 19, 5091-5101.

A prospective study of mitochondrial DNA copy number and the risk of prostate cancer

PURPOSE

Evidence suggests that mitochondrial DNA (mtDNA) copy number increases in response to DNA damage. Increased mtDNA copy number has been observed in prostate cancer (PCa) cells, suggesting a role in PCa development, but this association has not yet been investigated prospectively.

METHODS

We conducted a nested case-control study (793 cases and 790 controls) of men randomized to the screening arm of the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial (PLCO) to evaluate the association between pre-diagnosis mtDNA copy number, measured in peripheral blood leukocytes, and the risk of PCa. We used logistic regression to estimate odds ratios (OR) and 95% confidence intervals (CI) and polytomous logistic regression to analyze differences in associations by non-aggressive (Stage I/II AND Gleason grade < 8) or aggressive (Stage III/IV OR Gleason grade ≥ 8) PCa.

RESULTS

Although mtDNA copy number was not significantly associated with PCa risk overall (OR 1.23, 95% CI 0.97-1.55, p = 0.089), increasing mtDNA copy number was associated with an increased risk of non-aggressive PCa (OR 1.29, 95% CI 1.01-1.65, p = 0.044) compared to controls. No association was observed with aggressive PCa (OR 1.02, 95% CI 0.64-1.63, p = 0.933). Higher mtDNA copy number was also associated with increased PSA levels among controls (p = 0.014).

CONCLUSIONS

These results suggest that alterations in mtDNA copy number may reflect disruption of the normal prostate glandular architecture seen in early-stage disease, as opposed to reflecting the large number of tumor cells seen with advanced PCa.

Enucleation versus hepatectomy for giant hepatic haemangiomas: a meta-analysis

INTRODUCTION Hepatic haemangiomas are the most common benign liver tumours. They can be treated with surgical resection such as enucleation or hepatectomy if necessary. However, controversy remains over the clinical outcome and safety of these two methods. In this study, we performed a comprehensive meta-analysis to compare the efficacy of liver resection with enucleation for giant haemangiomas. METHODS The online databases PubMed, Embase and CNKI (China National Knowledge Infrastructure) were searched for relevant original articles. We compared operation time, blood loss, transfusion requirements, inflow occlusion time and postoperative complications between enucleation and hepatectomy. RESULTS Seven controlled clinical trials met the predefined inclusion criteria. Analysis indicated that the enucleation group had significantly shorter operation time (weighted mean difference, WMD -28.22, 95% confidence interval, CI, -54.82 to -1.62), less blood loss (WMD -395.92, 95% CI -521.25 to -270.58) and fewer complications (odds ratio, OR, 0.47, 95 % CI 0.34 to 0.65). There were no significant differences between enucleation and hepatectomy with regard to transfusion requirements (OR 0.61, 95% CI 0.22 to 1.68) and inflow occlusion time (WMD 7.91, 95% CI -5.62 to 21.44). CONCLUSIONS Enucleation has advantages over hepatectomy in relation to operation time, blood loss and complications. Enucleation is a safe and effective treatment for giant hepatic haemangioma.

Expression and clinical significance of PIWIL2 in hilar cholangiocarcinoma tissues and cell lines

The objective of this study was to explore the relationship between PIWI-like protein 2 (PIWIL2) and clinicopathological charac-teristics and prognosis after radical resection. To accomplish this, we analyzed PIWIL2 expression in hilar cholangiocarcinoma tissues and cell lines. PIWIL2 expression was detected by immunohistochemistry in 41 hilar cholangiocarcinoma samples and 10 control tissues. Western blotting and immunocytofluorescence were used to investigate PIWIL2 expression in the cholangiocarcinoma cell line QBC939 and the bile duct epithelial cell line HIBEpic. Univariate and multivariate surviv-al analyses were performed using the Kaplan-Meier method for hilar cholangiocarcinoma patients who underwent radical resection. PIWIL2 expression was significantly higher in the hilar cholangiocarcinoma tissues and QBC939 cells than in control tissues and HIBEpic cells, respectively (P < 0.05). Poorly and moderately differentiated cholan-giocarcinoma tissues had significantly higher PIWIL2 expression than well-differentiated tissues (P < 0.05). Univariate analysis demonstrated that high PIWIL2 expression was associated with shorter survival time after radical resection (P < 0.05). Multivariate analysis showed that PI-WIL2 expression was an independent prognostic factor after radical re-section of hilar cholangiocarcinoma (P < 0.05). PIWIL2 expression was also associated with tumor-node-metastasis stage and differentiation. PIWIL2 was an independent prognostic factor after radical resection of hilar cholangiocarcinoma.

Pooled analysis of mitochondrial DNA copy number and lung cancer risk in three prospective studies

BACKGROUND

We previously reported that higher levels of mitochondrial DNA copy number (mtDNA CN) were associated with lung cancer risk among male heavy smokers (i.e., ≥20 cigarettes per day) in the Alpha-Tocopherol Beta-Carotene (ATBC) study. Here, we present two additional prospective investigations nested in the Prostate, Lung, Colorectal, and Ovarian (PLCO) cancer screening trial and the Shanghai Women's Health Study (SWHS), and pooled with previously published data from ATBC.

MATERIALS

All DNA were extracted from peripheral whole blood samples using the phenol-chloroform method, and mtDNA CN was assayed by fluorescence-based qPCR. Multivariate unconditional logistic regression models were used to estimate ORs and 95% confidence intervals for the association of mtDNA CN and lung cancer risk.

RESULTS

Overall, mtDNA CN was not associated with lung cancer risk in the PLCO, SWHS, or pooled populations (all P trends > 0.42, P heterogeneity = 0.0001), and mtDNA CN was inversely associated with lung cancer risk among male smokers in PLCO, the opposite direction observed in ATBC. In addition, the mtDNA CN association observed among male heavy smokers in ATBC was the opposite direction in PLCO.

CONCLUSIONS

mtDNA CN was not consistently associated with lung cancer risk across three prospective study populations from Europe, Asia, and the United States.

IMPACT

This pooled study suggests no consistent association between prediagnostic mtDNA CN levels and lung cancer risk across several populations. Cancer Epidemiol Biomarkers Prev; 23(12); 2977-80. ©2014 AACR.

Mitochondrial DNA copy number and chronic lymphocytic leukemia/small lymphocytic lymphoma risk in two prospective studies

BACKGROUND

Mitochondrial DNA copy number (mtDNA CN) may be modified by mitochondria in response to oxidative stress. Previously, mtDNA CN was associated with non-Hodgkin lymphoma (NHL) risk, particularly chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL). We conducted a replication study in the Prostate, Lung, Colorectal, and Ovarian (PLCO) study and pooled with published ATBC (Alpha-Tocopherol, Beta-Carotene) data.

METHODS

In PLCO, 292 NHL cases (95 CLL/SLL cases) and 301 controls were pooled with 142 NHL cases (47 CLL/SLL cases) and 142 controls from ATBC. Subjects answered a questionnaire and provided blood. DNA was extracted from prediagnostic peripheral white blood, and mtDNA CN assayed by quantitative polymerase chain reaction. Unconditional logistic regression estimated mtDNA CN and NHL risk by odds ratios (OR) and 95% confidence intervals (95% CI).

RESULTS

Greater mtDNA CN was associated with increased risk of CLL/SLL among males in PLCO (3rd vs. 1st tertile: OR, 2.21; 95% CI, 1.03-4.72; Ptrend: 0.049) and pooled (T3 vs. T1: OR, 3.12; 95% CI, 1.72-5.68; Ptrend: 0.0002). Association was stronger among male smokers (Ptrend: <0.0001) and essentially identical for cases diagnosed <6, >6-8, and >8 years from blood draw (pooled: Pinteraction: 0.65). mtDNA CN and risk of other NHL subtypes and multiple myeloma showed no association.

CONCLUSIONS AND IMPACT

Mitochondrial DNA CN was associated with risk of CLL/SLL in males/male smokers. The risk was observed among cases diagnosed as long as 8 years after blood draw. These results suggest that higher mtDNA CN may reflect a process involved in CLL/SLL development.

Mitochondrial DNA copy number and future risk of B-cell lymphoma in a nested case-control study in the prospective EPIC cohort

It has been suggested that mitochondrial dysfunction and DNA damage are involved in lymphomagenesis. Increased copy number of mitochondrial DNA (mtDNA) as a compensatory mechanism of mitochondrial dysfunction previously has been associated with B-cell lymphomas, in particular chronic lymphocytic leukemia (CLL). However, current evidence is limited and based on a relatively small number of cases. Using a nested case-control study, we extended these findings with a focus on subtype-specific analyses. Relative mtDNA copy number was measured in the buffy coat of prospectively collected blood of 469 lymphoma cases and 469 matched controls. The association between mtDNA copy number and the risk of developing lymphoma and histologic subtypes was examined using logistic regression models. We found no overall association between mtDNA and risk of lymphoma. Subtype analyses revealed significant increased risks of CLL (n = 102) with increasing mtDNA copy number (odds ratio = 1.34, 1.44, and 1.80 for quartiles 2-4, respectively; P trend = .001). mtDNA copy number was not associated with follow-up time, suggesting that this observation is not strongly influenced by indolent disease status. This study substantially strengthens the evidence that mtDNA copy number is related to risk of CLL and supports the importance of mitochondrial dysfunction as a possible mechanistic pathway in CLL ontogenesis.

Delivering healthy mitochondria for the therapy of mitochondrial diseases and beyond

Mitochondrial transfer has been demonstrated to a play a physiological role in the rescuing of mitochondrial DNA deficient cells by co-culture with human mesenchymal stem cells. The successful replacement of mitochondria using microinjection into the embryo has been revealed to improve embryo maturation. Evidence of mitochondrial transfer has been shown to minimize injury of the ischemic-reperfusion rabbit heart model. In this mini review, the therapeutic strategies of mitochondrial diseases based on the concept of mitochondrial transfer are illustrated, as well as a novel approach to peptide-mediated mitochondrial delivery. The possible mechanism of peptide-mediated mitochondrial delivery in the treatment of the myoclonic epilepsy and ragged-red fiber disease is summarized. Understanding the feasibility of mitochondrial manipulation in cells facilitates novel therapeutic skills in the future clinical practice of mitochondrial disorder.

Presence of cytomegalovirus DNA in leucocytes is associated with increased oxidative stress and subclinical atherosclerosis in healthy adults

OBJECTIVE

Investigate the latent cytomegalovirus (CMV) infection as a biomarker of oxidative stress and atherosclerosis.

METHODS

Latent CMV infection was diagnosed in healthy individuals with PCR-evidence of CMV DNA in peripheral leucocytes. Oxidative stress and atherosclerosis were measured by mitochondrial DNA oxidative damage index (mtDNA(ΔCT)) and intima media thickness (IMT).

RESULTS

The CMV DNA positive subjects had a higher mean mtDNA(ΔCT) and greater IMT than subjects in the control group.

CONCLUSIONS

Presence of CMV DNA in leucocytes, as a marker of latent CMV infection, was associated with increased levels of oxidative stress and subclinical atherosclerosis in healthy adults.

A nested case-control study of leukocyte mitochondrial DNA copy number and renal cell carcinoma in the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial

Mitochondrial DNA (mtDNA) is vulnerable to mutations, and the number of copies of mtDNA per cell may increase to compensate for DNA damage. Case-control studies have reported associations between altered mtDNA copy number and risk of renal cell carcinoma (RCC); however, this association has not been investigated prospectively. We conducted a nested case-control study (252 cases and 504 controls) of RCC risk in relation to pre-diagnostic leukocyte mtDNA copy number in the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial. mtDNA copy number was measured in triplicate using a fluorescence-based quantitative PCR assay; samples from 22 cases and 36 controls could not be assayed, leaving 230 cases and 468 controls for analysis. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using unconditional logistic regression. High mtDNA copy number was associated with an increased risk of RCC, both overall (highest quartile versus lowest: OR = 2.0, 95% CI = 1.2-3.2; P trend = 0.002) and among cases diagnosed ≥6 years after blood collection (OR = 2.6, 95% CI = 1.4-5.0; P trend = 0.003). These findings did not differ significantly by sex, body mass index, history of hypertension or smoking status (P interaction ≥ 0.3). Results of this study suggest that high pre-diagnostic leukocyte mtDNA copy number, a suspected marker of oxidative DNA damage and mitochondrial dysfunction, is associated with increased future RCC risk.

ACAT Inhibitory Activity of Exudates from Calocedrus Macrolepis Var. Formosana

Cholesterol acyltransferase (ACAT) is an enzyme controlling cholesterol esterification in cells. Large amounts of cholesterol esters accumulate in macrophages and smooth muscle cells of blood vessel walls resulting in the initial stages of atherosclerosis. Thus, atherosclerosis might be inhibited through inhibition of the activity of ACAT. In the present study, we identified by spectral analysis and chromatographic quantification that ferruginol was the most abundant component of exudates secreted from the wounding site of Calocedrus macrolepis Kurz var. formosana. Results obtained from the cholesterol absorption assay revealed that ferruginol exhibited a significant inhibitory activity on cholesterol absorption in mice macrophages (RAW 264.7 cell). Based on the results from analyzing the ratio of cholesterol esterification, ferruginol dose-dependently suppressed cholesterol esterification and the IC50 value was 2.0 μg/mL. In conclusion, ferruginol revealed strong inhibitory activities that retarded the absorption and esterification of cholesterol in cells. Our finding indicates that ferruginol might possess a potential for development as a pharmaceutical product for preventing arteriosclerosis.

ACAT inhibitory activity of exudates from Calocedrus macrolepis var. formosana

Cholesterol acyltransferase (ACAT) is an enzyme controlling cholesterol esterification in cells. Large amounts of cholesterol esters accumulate in macrophages and smooth muscle cells of blood vessel walls resulting in the initial stages of atherosclerosis. Thus, atherosclerosis might be inhibited through inhibition of the activity of ACAT. In the present study, we identified by spectral analysis and chromatographic quantification that ferruginol was the most abundant component of exudates secreted from the wounding site of Calocedrus macrolepis Kurz var. formosana. Results obtained from the cholesterol absorption assay revealed that ferruginol exhibited a significant inhibitory activity on cholesterol absorption in mice macrophages (RAW 264.7 cell). Based on the results from analyzing the ratio of cholesterol esterification, ferruginol dose-dependently suppressed cholesterol esterification and the IC50 value was 2.0 microg/mL. In conclusion, ferruginol revealed strong inhibitory activities that retarded the absorption and esterification of cholesterol in cells. Our finding indicates that ferruginol might possess a potential for development as a pharmaceutical product for preventing arteriosclerosis.

FGF21 in ataxia patients with spinocerebellar atrophy and mitochondrial disease

BACKGROUND

Serum fibroblast growth factor 21 (FGF21) was proven to be a useful biomarker for the presence of mitochondrial neuromuscular disease.

METHODS

In the present study, we used the difference in the serum FGF21 level to differentiate between ataxia patients with hereditary spinocerebellar atrophy (SCA-ataxia) and those with mitochondrial syndrome (Mito-ataxia). Patients with SCA-ataxia (SCA2, SCA3) and Mito-ataxia (MELAS, MERRF, LHON, maternal inherited hearing impairment mtDNA A1555G mutation) were recruited in this study. All SCA-ataxia patients revealed a consistent pattern of cerebellar atrophy. On the contrary, some of the Mito-ataxia patients exhibited a vascular lesion with cerebellar infarction.

RESULTS

Extremely higher levels of serum FGF21 were found in the Mito-ataxia patients with MERRF and MELAS diseases, but not in patients with SCA-ataxia or LHON/mtDNA A1555G mutation. The positive trend between the mtDNA heteroplasmy and serum FGF21 was indicated in either MERRF (P=0.003, r=0.923) or MELAS (P=0.070, r=0.566) patients.

CONCLUSION

Serum FGF21 can be applied as the first molecular screening among patients suspected to be victims of hereditary ataxia with neuromuscular degeneration prior to mass genetic screening.

Constitutive mitochondrial DNA copy number in peripheral blood of melanoma families with and without CDKN2A mutations

Quantitative changes in mitochondrial DNA (mtDNA) have been associated with the risk of a number of human cancers; however, the relationship between constitutive mtDNA copy number in blood and the risk of familial cutaneous malignant melanoma (CMM) has not been reported. We measured mtDNA copy number using quantitative PCR in blood-derived DNA from 136 CMM cases and 302 controls in 53 melanoma-prone families (23 segregating CDKN2A germline mutations). MtDNA copy number did not vary by age, sex, pigmentation characteristics, or CMM status. However, germline CDKN2A mutation carriers had significantly higher mean mtDNA copy number compared to non-carriers, particularly among CMM cases (geometric mean mtDNA copy number of 144 and 111 for carrier versus non-carrier, respectively; P= 0.02). When adjusting for age, sex, and familial correlation, having increasing mtDNA copy number was significantly associated with CDKN2A mutation status among CMM cases (OR=1.47, P_trend=0.024). In particular, individuals with specific CDKN2A mutations with the potential to inactivate or reduce the level of the p16-INK4 reactive oxygen species (ROS) protective function had significantly increased mtDNA copy number levels (P=0.035). Future research in prospective studies is required to validate these findings and to further investigate mtDNA copy number in both blood and melanoma tissues in relation to CMM risk and CDKN2A mutation status.

Mitochondrial DNA copy number and pancreatic cancer in the alpha-tocopherol beta-carotene cancer prevention study

Diabetes, obesity, and cigarette smoke, consistent risk factors for pancreatic cancer, are sources of oxidative stress in humans that could cause mitochondrial DNA (mtDNA) damage and increase mtDNA copy number. To test whether higher mtDNA copy number is associated with increased incident pancreatic cancer, we conducted a nested case-control study in the Alpha-Tocopherol Beta Carotene Cancer Prevention (ATBC) Study cohort of male smokers, aged 50 to 69 years at baseline. Between 1992 and 2004, 203 incident cases of pancreatic adenocarcinoma occurred (follow-up: 12 years) among participants, with whole blood samples used for mtDNA extraction. For these cases and 656 controls, we calculated ORs and 95% CIs using unconditional logistic regression, adjusting for age, smoking, and diabetes history. All statistical tests were two sided. Higher mtDNA copy number was significantly associated with increased pancreatic cancer risk (highest vs. lowest mtDNA copy number quintile, OR = 1.64, 95% CI = 1.01-2.67, continuous OR = 1.14, 95% CI 1.06-1.23), particularly for cases diagnosed during the first 7 years of follow-up (OR = 2.14, 95% CI = 1.16-3.96, P(trend) = 0.01, continuous OR = 1.21, 95% CI = 1.10-1.33), but not for cases occurring during follow-up of 7 years or greater (OR = 1.14, 95% CI = 0.53-2.45, continuous OR = 1.05, 95% CI = 0.93-1.18). Our results support the hypothesis that mtDNA copy number is associated with pancreatic cancer and could possibly serve as a biomarker for pancreatic cancer development.

Inhibitory effect of human breast cancer cell proliferation via p21-mediated G1 cell cycle arrest by araliadiol isolated from Aralia cordata Thunb

A new polyacetylenic compound, araliadiol, was isolated from the leaves of Aralia cordata Thunb. (Araliaceae). The structure of araliadiol was determined to be 3( S),8( R)-pentadeca-1,9( Z)-diene-4,6-diyne-3,8-diol by MS, NMR, IR, and UV spectroscopic analysis as well as Mosher ester reaction. Araliadiol displayed a significant inhibitory effect on the growth of a human breast adenocarcinoma cell line (MCF-7), with an IC (50) value for cytotoxicity of 6.41 µg/mL. Cell cycle analysis revealed that the proportion of cells in the G (1) phase of the cell cycle increased in a dose-dependent manner (from 54.7 % to 72.0 %) after 48 h exposure to araliadiol at dosages ranging from 0 to 80 µM. The results suggest that araliadiol inhibits cell cycle progression of MCF-7 at the G (1)-S transition. After treatment with araliadiol, phosphorylation of retinoblastoma protein (Rb) in MCF-7 cells was inhibited, accompanied by a decrease in the levels of cyclin D (3) and cyclin-dependent kinase 4 (cdk4) and an increase in the expression of p21 (WAF-1/Cip1). However, the expression of phosphorylated p53 (Ser15) and Chk2 was not altered in MCF-7 cells. These findings indicate that araliadiol exhibits its growth-inhibitory effects on MCF-7 cells through downregulation of cdk4 and cyclin D (3), and upregulation of p21 (WAF-1/Cip1) by a p53-independent mechanism.

Gluten sensitivity: associated sporadic cerebellar ataxia in Taiwan

PURPOSE

Gluten sensitivity (GS) is related to the pathogenesis of sporadic or hereditary ataxia.

METHODS

Total of 194 healthy controls and patients with either hereditary ataxia (n=207) or sporadic ataxia (n=361) were tested for the circulating gluten-related autoantibodies which serve as biomarkers to interpret the existence of GS.

RESULTS

The incidences of GS in each population were 1% in normal subjects, 2% in hereditary ataxia patients and 9% in sporadic ataxia patients. High serum level of anti-gliadin IgG/IgA and t-transglutaminase IgA were disclosed at the sporadic ataxia patients compared with normal subjects. However, the anti-gliadin IgG is more specific to the disease of sporadic ataxia.

CONCLUSION

Relatively higher incidence of GS was found in the population of sporadic ataxia patients but not in either normal subjects or hereditary ataxia patients in Taiwan. Anti-gliadin IgG still is a very powerful indicator to implicate the immune-related sporadic ataxia and we conclude that GS-related sporadic ataxia exists in Taiwan with linkage to autoimmune events.

Mitochondria DNA deletion and copy numbers of cumulus cells associated with in vitro fertilization outcomes

OBJECTIVE

Mitochondria are important organelles in cell biology. We aimed to study the effects of mitochondrial DNA variations in cumulus cells (CCs) upon in vitro fertilization and embryo transfer (IVF-ET) outcomes.

STUDY DESIGN

A total of 51 women undergoing IVF-ET were recruited for the study. The CCs were collected during oocyte retrievals. Mitochondria DNA 4977-bp deletion (dmtDNA-delta5Kb) and copy numbers (MCN) of CCs were analyzed by polymerase chain reaction. The relationships of dmtDNA-delta5Kb and MCN with patients' age, embryo qualities and pregnancy rates (PRs) were detected and compared.

RESULTS

PRs were positively correlated with younger age, better transferred embryo qualities and lower dmtDNA-delta5Kb ratios in CCs. The dmtDNA-delta5Kb status was positively associated with older age and higher MCN but was not associated with embryo morphologic scoring. The dmtDNA-delta5Kb ratios of transferred embryos in pregnancy and nonpregnancy groups were 0% and 10.4%, respectively. The dmtDNA-delta5Kb in > or = 34-year-old and <34-year-old groups were 6.9% and 3.2%, respectively.

CONCLUSION

The dmtDNA-delta5Kb and MCN statuses of CCs are negatively associated with PRs, which might be potential tools for oocyte evaluation and embryo selections during IVF-ET.

Using autocloning effects to develop broad-bandwidth, omnidirectional antireflection structures for silicon solar cells

In this study, we used the autocloning effect on pyramid structures to develop broad-bandwidth, omnidirectional antireflection structures for silicon solar cells. The angular dependence of reflectance on several pyramid structures was systematically investigated. The deposition of three-layer autocloned films reduced the refractive index gap between air and silicon, resulting in an increase in the amount of transmitted light and a decrease in the total light escaping. The average reflectance decreased dramatically to ca. 2-3% at incident angles from 0 to 60° for both sub-wavelength- and micrometer-scale pyramid structures. The measured reflectance of the autocloned structure was less than 4% in the wavelength range from 400 to 1000 nm for incident angles from 0 to 60°. Therefore, the autocloning technique, combined with optical thin films and optical gradient structures, is a practical and compatible method for the fabrication of broad-bandwidth, omnidirectional antireflection structures on silicon solar cells.

Depletion of mitochondrial DNA in leukocytes of patients with poly-Q diseases

Polyglutamine (poly-Q) diseases are late-onset neurodegenerative disorders arising from the expansion of an unstable CAG repeat in the affected gene, which is translated to a tract of glutamine residues. This kind of mutant proteins may be aggregated and accumulated, and thereby enhance cellular oxidative stress. In one of our previous studies (Free Radic. Res. 2003;37:1307-17), we found that alteration in the leukocyte mtDNA content is very sensitive to the level of oxidative stress in blood. Thus, we proposed that leukocyte mtDNA content may be used as a biomarker to predict the severity of clinical manifestation of poly-Q diseases. We recruited 50 healthy subjects and 114 patients with poly-Q diseases, including spinal cerebellar atrophy 2/3, spinal bulbar muscular atrophy, and Huntington chorea. We found that mtDNA in leukocytes was depleted in patients with poly-Q diseases (P<0.05). Moreover, the results showed that patients with lower mtDNA content more frequently manifested multiple-symptom disorders and had high CAG repeat numbers in the mutant genes. In conclusion, we suggest that leukocyte mtDNA content correlates with the length of GAG repeat and may serve as an index of the severity of poly-Q diseases.

B-group vitamins, MTHFR C677T polymorphism and carotid intima-media thickness in clinically healthy subjects

OBJECTIVE

Plasma B-group vitamins and age may affect the carotid intima-media thickness (IMT) in subjects with different 677TT genotype of the methylenetetrahydrofolate reductase (MTHFR) gene.

DESIGN

A hospital-based cross-study.

SETTING

Genomic and Vascular Center, Changhua Christian Hospital, Changhua, Taiwan.

SUBJECTS

Five hundred and forty-one clinically healthy subjects.

INTERVENTION

Fasting plasma, homocysteine (Hcy), vitamin B(6), vitamin B(12), folate and B-mode carotid ultrasound.

RESULTS

MTHFR genotype, plasma concentrations of folate, vitamin B(6) and vitamin B(12) and age were significantly correlated to the plasma Hcy concentration. MTHFR 677TT carriers had higher concentrations of Hcy than did subjects with the CC and CT genotypes. Age, sex, body mass index and plasma Hcy were independent contributors to increase carotid IMT. However, with stratification by mean value of age and B-group vitamins concentrations, we found that at advanced age, lower plasma folate and vitamin B(12) were three risk factors involved in the enhancing effect of the MTHFR 677TT genotype on the increase of plasma Hcy and carotid IMT.

CONCLUSION

MTHFR 677TT-related carotid atherosclerosis was only identified in healthy elderly subjects with lower level of plasma folate and vitamin B(12).

SPONSORSHIP

Changhua Christian Hospital.

Alteration of the copy number of mitochondrial DNA in leukocytes of patients with hyperlipidemia

Lipid metabolism in leukocytes may be disturbed by mitochondrial dysfunction caused by depletion of mitochondrial DNA (mtDNA) in response to an increase of oxidative stress in blood circulation. It is possible that alteration in mtDNA copy number of the leukocyte is involved in the impairment of the scavenging of oxidatively modified plasma proteins such as oxidized low-density lipoprotein (oxLDL). To test this hypothesis, we recruited 91 healthy subjects and 63 patients with hyperlipidemia (LDL >130 mg/dL) for this study. The copy number of mtDNA in the leukocyte and the titer of oxLDL IgG autoantibody (oLAB) were determined as indices of the oxidative stress response of immune cells. The results revealed a significant higher level of plasma oxLDL, lower titer of oLAB, and decreased copy number of mtDNA in patients with hyperlipidemia (P <0.05). In the analysis of partial correlations under age control, we found that an increase in the copy number of mtDNA was positively correlated with an increase in the level of oLAB (P <0.005, r = 0.3002) and a decrease in the oxLDL level (P <0.05, r = -0.2654) in healthy subjects but not in patients. Based on the results obtained from this case-control study, we conclude that the increase of mtDNA copy number might provide the leukocyte an increased capability of scavenging oxLDL, possibly by enhanced generation of oLAB in healthy subjects, but not in hyperlipidemic patients who had lower mtDNA copy numbers in their leukocytes. Taken together, these findings suggest that an alteration of mtDNA copy number in the leukocyte may be one of the risk factors for hyperlipidemia.

High prevalence of the COII/tRNA(Lys) intergenic 9-bp deletion in mitochondrial DNA of Taiwanese patients with MELAS or MERRF syndrome

The COII/tRNA(Lys) intergenic 9-bp deletion (MIC9D) of mitochondrial DNA (mtDNA) has been established as a genetic polymorphism for Asian-Pacific populations. We investigated whether this small mtDNA deletion is co-transmitted with human diseases such as mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS) and myoclonic epilepsy with ragged-red fibers (MERRF) syndromes. Forty unrelated Taiwanese families, including 12 families with MERRF and A8344G mtDNA mutation and 28 families with MELAS and A3243G mutation of mtDNA, respectively, were recruited in this study. In addition, 199 healthy subjects were recruited as control. We found that the frequency of occurrence of mtDNA with the MIC9D polymorphism in healthy subjects was 21% (41/199). However, the incidence of the MIC9D polymorphism was 67% (8/12) among the probands of all the families with MERRF syndrome (P = 0.001; OR = 8) and 39% (11/28) among the probands of the families with MELAS syndrome (P = 0.038; OR = 2). This finding indicates that the frequency of occurrence of mtDNA with the MIC9D polymorphism in patients with MERRF or MELAS syndrome is higher than that of healthy subjects. The prevalence of mitochondrial encephalomyopathies in relation to the MIC9D polymorphism of mtDNA in Taiwanese population is discussed.

The Effects of Different Electrical Stimulation Protocols on Nerve Regeneration Through Silicone Conduits

BACKGROUND

The effects of electrical stimulation on the regeneration of transected nerves through silicone rubber conduits may depend on the stimulation protocol.

METHODS

Rat sciatic nerve was transected and reconnected using a silicone rubber conduit with a 7-mm gap. The subjects were divided into nine groups. Each group received one protocol of electrical stimulation 30 minutes each day for 3 weeks. The effects of electrical stimulation were evaluated through morphologic methods.

RESULTS

Direct current stimulation increased nerve fiber bundle area without significantly affecting the number of myelinated fibers, resulting in decreased nerve fiber density. All the pulse current stimulation protocols as a group decreased the nerve fiber bundle area without affecting the number of myelinated fibers, resulting in increased nerve fiber density. Within the pulse current stimulation protocols, stimulation frequency affected nerve fiber density, whereas current strength did not.

CONCLUSIONS

Stimulation protocols had significant influences on the benefit of electrical stimulation in nerve regeneration.

Contribution of conjugated linoleic acid to the suppression of inflammatory responses through the regulation of the NF-kappaB pathway

Data from a number of researchers have shown that conjugated linoleic acid (CLA) has some beneficial health activities in animal models. Because inflammatory responses are associated with pathophysiology of many diseases, the aim of this study is to explore the effect and mechanism of CLA in the regulation of lipopolysaccharide (LPS)-induced inflammatory responses in RAW 264.7 macrophages. The addition of increasing levels of CLA proportionally augmented the incorporation of CLA in cultures. CLA diminished LPS-induced mRNA and protein expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX2) as well as subsequent production of nitric oxide and prostaglandin E(2), respectively. We further examined the effect of CLA on LPS-induced NF-kappaB activation by Western blot and the electrophoretic mobility shift assay. The addition of CLA at 200 microM significantly diminished LPS-induced protein expression of the cytoplasmic phosphorylated inhibitor kappaBalpha and nuclear p65 as well as NF-kappaB nuclear protein-DNA binding affinity. In conclusion, our data suggest that CLA may inhibit LPS-induced inflammatory events in RAW 264.7 macrophages and this inhibitory activity of CLA, at least in part, occurs through CLA modulating the NF-kappaB activation and therefore negatively regulating expression of inflammatory mediators.

The effects of Ginkgo biloba extracts on the memory and motor functions of rats with chronic cerebral insufficiency

The main goal of the current study was to investigate the effects of two Ginkgo leaf extracts, EGb 761 and an extract of local Ginkgo leaf (LGb), on the memory and motor functions of rats with chronic cerebral insufficiency (produced by bilateral common carotid artery ligation). After the operation, spatial memory and motor functions were tested for over 80 days. Tests included (1) radial-arm maze test for testing spatial memory and locomotor activity and (2) muscle force and hind limbs for escape. The results indicate that both EGb 761 and LGb improved spatial memory from the second week after operation, but only EGb 761 delayed deterioration of motor functions from the fifth week after operation.

Contribution of endotoxin in macrophage cytokine response to ambient particles in vitro

Ambient particles may cause pulmonary inflammation with ensuing morbidity. Particle-induced production of proinflammatory cytokines in vitro has been used as an indicator of particle toxicity. To identify particle components that were related to particle toxicity, Andersen dichotomous impactors were used to collect ambient fine (PM(2.5)) and coarse (PM(2.5-10)) particles in central Taiwan with extraction in endotoxin-free water. Mouse monocyte-macrophage cell line RAW 264.7 cells were exposed to particle extracts at 40 micro g/ml for 16 h, and tumor necrosis factor-alpha (TNF-alpha) was measured in the medium by enzyme-linked immunosorbent assay (ELISA). Cell viabilities were all greater than 82%. Coarse particles stimulated higher TNF-alphaproduction than fine particles, and this was associated with greater particulate endotoxin content. Polymyxin B inhibited 42% of TNF-alpha production elicited by coarse particles and 32% of TNF-alpha production elicited by fine particles. In fine particles, TNF-alpha production was negatively correlated with Zn content, while no element in coarse particles correlated with TNF-alpha production. Results suggest that endotoxin and other components may be important factors for TNF-alpha production by macrophages in vitro.

Effect of different solvents and crosslinkers on cytocompatibility of Type II collagen scaffolds for chondrocyte seeding

Type II collagen extracted from porcine costal cartilage was evaluated as scaffolds for cartilage tissue engineering. Chemical crosslinkers were employed to improve the mechanical properties and the resistance toward degradation. Films and porous scaffolds were prepared from collagen solutions dissolved in 3% acetic acid (designated A) or in deionized water (designated W) and crosslinked by an epoxy (designated E) or by a carbodiimide (designated C). Immortalized rat chondrocytes and rabbit chondrocytes were used to assess cytocompatibility of crosslinked collagen matrices. Cell adhesion rate onto the films made by different preparations ranked in the order of WE > or = WC > AC > or = AE. Cell proliferation ranked in the order of AC > WC > AE > or = WE. Cells maintained round morphology only on AC and WC films. In 3-D seeding, AC scaffolds also were found to be the most cytocompatible. WC scaffolds, however, had better dimensional stability. It was concluded that Type II collagen scaffolds, when prepared by using deionized water as the solvent and carbodiimide as the crosslinker, could promote chondrocyte growth and matrix production.

Spatio-temporal variations of sulphur dioxide patterns with wind conditions in central Taiwan

Sulphur dioxide (SO2) is one of the main atmospheric pollutants in central Taiwan. This article analyses the SO2 concentration seasonal variations and spatial distribution using data obtained from ten air quality monitoring stations and the Taiwan Weather Bureau. It reveals that SO2 concentration is high in winter and low in summer and that high concentration centers are located south of the Taichung coal-fired power plant, the main source of SO2 emissions in the region. The location of high concentration centers changes with different prevailing winds. SO2 variations due to wind direction are not unique. During short periods, when meteorological conditions are constant, variation in the pollution sources cause variations in the spatial distribution. This has been deduced by appreciation of 'Intervention analysis' to time series of hourly data.

An evaluation of susceptibility testing methods for ampicillin-sulbactam using a panel of beta-lactamase-producing bacteria

Bacteria possessing TEM-1-like beta-lactamases are generally regarded as susceptible to ampicillin-sulbactam (SAM), while those harboring OXA-1 enzymes are considered resistant. The current study was undertaken to compare susceptibility testing using various combinations of ampicillin and sulbactam to improve clinical correlation. Members of the Enterobacteriaceae family harboring TEM-1, SHV-1 or OXA-1-like beta-lactamases were tested using the agar dilution method. A substantial proportion of strains harboring OXA-1-like beta-lactamases showed false susceptibility to SAM at the 1:1 ratio or fixed sulbactam concentration of 8 microg/ml. At a fixed sulbactam concentration of 4 microg/ml, the activity of ampicillin-sulbactam appeared to be reduced, with large numbers of TEM-1 producers becoming frankly resistant. Results obtained with the 2:1 ratio exhibited the closest correlation with that obtained by the currently recommended disk diffusion test. However, very major errors were still found between the disk diffusion test and agar dilution test, suggesting the necessity for consideration of a change in criteria for interpretation of disk diffusion test results. In conclusion, SAM susceptibility testing by agar dilution using other than a 2:1 ratio is not recommended and results should be interpreted with caution.