Hepatic oxidative stress in fructose-induced fatty liver is not caused by sulfur amino acid insufficiency

Fructose-sweetened liquid consumption is associated with fatty liver and oxidative stress. In rodent models of fructose-mediated fatty liver, protein consumption is decreased. Additionally, decreased sulfur amino acid intake is known to cause oxidative stress. Studies were designed to test whether oxidative stress in fructose-sweetened liquid-induced fatty liver is caused by decreased ad libitum solid food intake with associated inadequate sulfur amino acid intake. C57BL6 mice were grouped as: control (ad libitum water), fructose (ad libitum 30% fructose-sweetened liquid), glucose (ad libitum 30% glucose-sweetened water) and pair-fed (ad libitum water and sulfur amino acid intake same as the fructose group). Hepatic and plasma thiol-disulfide antioxidant status were analyzed after five weeks. Fructose- and glucose-fed mice developed fatty liver. The mitochondrial antioxidant protein, thioredoxin-2, displayed decreased abundance in the liver of fructose and glucose-fed mice compared to controls. Glutathione/glutathione disulfide redox potential (E(h)GSSG) and abundance of the cytoplasmic antioxidant protein, peroxiredoxin-2, were similar among groups. We conclude that both fructose and glucose-sweetened liquid consumption results in fatty liver and upregulated thioredoxin-2 expression, consistent with mitochondrial oxidative stress; however, inadequate sulfur amino acid intake was not the cause of this oxidative stress.     

Erratum to: Clinical importance of Bcl-6-positive non-deep-site involvement in non-HIV-related primary central nervous system diffuse large B-cell lymphoma

Journal of Neuro-Oncology -     

Inhibitory effect on TNF-α-induced IL-8 secretion in HT-29 cell line by glyceroglycolipids from the leaves of Ficus microcarpa

Bioassay-guided fractionation based on the anti-inflammatory activity of a methanol extract of Ficus microcarpa leaves led to the isolation of seven galactolipids: 2(S)-3-O-octadeca-9Z,12Z,15Z-trienoylglyceryl-O-β-D-galactopyranoside (1), (2S)-2,3-O-dioctadeca-9Z,12Z,15Z-trienoylglyceryl-O-β-D-galactopyranoside (2), (2S)-2,3-O-dioctadeca-9Z,12Z-dienoylglyceryl-O-β-D-galactopyranoside (3), (2S)-3-O-octadeca-9Z,12Z,15Z-trienoylglyceryl-6′-O-(α-D-galactopyranosyl)-β-D-galactopyranoside (4), (2S)-2,3-O-dioctadeca-9Z,12Z,15Z-trienoylglyceryl-6’-O-(α-D-galactopyranosyl)-β-D-galactopyranoside (5), gingerglycolipid B (6), and (2S)-2,3-O-dioctadeca-9Z,12Z-dienoylglyceryl-6′-O-(α-D-galactopyranosyl)-β-D-galactopyranoside (7). Their chemical structures were elucidated by mass, 1D-, and 2D-NMR spectroscopic methods as well as chemical methods. The antiinflammatory effect of these compounds on TNF-α induced IL-8 secretion in the HT-29 cell line was evaluated. All above galactolipids showed significant inhibition ranging 40% at a concentration of 50 μM. The results suggest that galactolipids from the leaves of F. microcarpa may be used as potent anti-inflammatory agents.     

Plasma-arc generated light inhibits proliferation and induces apoptosis of human gingival fibroblasts in a dose-dependent manner.

OBJECTIVE: This study examined the effects of blue light exposure on the proliferation and cytotoxicity of human gingival fibroblasts (HGF). Cellular mechanism by which blue light causes cytotoxic effects was also investigated. METHODS: HGF were exposed to the plasma-arc generated blue light with various energy densities ranging from 2 to 48J/cm(2). After light exposure of the cells, they were processed for analyzing tritium incorporation, succinate dehydrogenase (SDH) activity, trypan blue exclusion, and DNA fragmentation. In addition, possible mechanism of the light-mediated cytotoxicity was investigated through flow cytometric and Western blot analyses. RESULTS: Blue light exposure significantly inhibited proliferation and SDH activity of HGF in a dose-dependent manner; exposure more than 12J/cm(2) had a toxic effect on the cells. The blue light-induced cytotoxicity of the cells resulted from apoptosis, as proven by the migration of many cells to the sub-G(1) phase of cell cycle and the appearance of DNA ladders. Additional experiments revealed that blue light induces apoptosis of HGF through mitochondrial stress and poly (ADP ribose) polymerase cleavage. SIGNIFICANCE: This study suggests that plasma-arc generated blue light exerts some harm to cells, particularly damaging effect to DNA, and thus a long curing time more than recommended can cause biological damage on the oral tissue.     

Effects of heavy metals on transcription and enzyme activity of Na<Superscript>+</Superscript>/K<Superscript>+</Superscript>-ATPase in the monogonont rotifer, <Emphasis Type="Italic">Brachionus koreanus</Emphasis>

Heavy metals can lead to osmotic stress by disrupting the regulation of sodium ion in aquatic organisms. In this study, gene expression patterns and enzymatic activities of Na⁺/K⁺-ATPase in the monogonont rotifer, Brachionus koreanus were measured after exposure to different Cd (7.5, 15, and 30 mg/L), and Pb (0.1, 0.5, and 1.0 mg/L), respectively. As results, a significant increase in Bk Na⁺/K⁺-ATPase activity was observed after exposure to Cd and Pb in a concentration-dependent manner. Bk Na ⁺/K ⁺-ATPase mRNA level was significantly upregulated in the Cd-exposed group, whereas its level was reduced in the Pb-exposed group. These findings indicate that heavy metals could induce osmotic stress in B. koreanus, and Na⁺/K⁺-ATPase may be involved in cellular ho-meostasis in response to heavy metal exposure. This study is helpful for the understanding of the molecular mode of action of B. koreanus in response to heavy metals.     

Reproductive health services in Malawi: an evaluation of a quality improvement intervention

Objective

this study was to evaluate the impact of a quality improvement initiative in Malawi on reproductive health service quality and related outcomes.

Design

(1) post-only quasi-experimental design comparing observed service quality at intervention and comparison health facilities, and (2) a time-series analysis of service statistics.

Setting

sixteen of Malawi's 23 district hospitals, half of which had implemented the Performance and Quality Improvement (PQI) intervention for reproductive health at the time of the study.

Participants

a total of 98 reproductive health-care providers (mostly nurse–midwives) and 139 patients seeking family planning (FP), antenatal care (ANC), labour and delivery (L&;D), or postnatal care (PNC) services.

Intervention

health facility teams implemented a performance and quality improvement (PQI) intervention over a 3-year period. Following an external observational assessment of service quality at baseline, facility teams analysed performance gaps, designed and implemented interventions to address weaknesses, and conducted quarterly internal assessments to assess progress. Facilities qualified for national recognition by complying with at least 80% of reproductive health clinical standards during an external verification assessment.

Measurements

key measures include facility readiness to provide quality care, observed health-care provider adherence to clinical performance standards during service delivery, and trends in service utilisation.

Findings

intervention facilities were more likely than comparison facilities to have the needed infrastructure, equipment, supplies, and systems in place to offer reproductive health services. Observed quality of care was significantly higher at intervention than comparison facilities for PNC and FP. Compared with other providers, those at intervention facilities scored significantly higher on client assessment and diagnosis in three service areas, on clinical management and procedures in two service areas, and on counselling in one service area. Service statistics suggest that the PQI intervention increased the number of Caesarean sections, but showed no impact on other indicators of service utilisation and skilled care.

Conclusions

the PQI intervention showed a positive impact on the quality of reproductive health services. The effects of the intervention on service utilisation had likely not yet been fully realized, since none of the facilities had achieved national recognition before the evaluation. Staff turnover needs to be reduced to maximise the effectiveness of the intervention.

Implications for practice

the PQI intervention evaluated here offers an effective way to improve the quality of health services in low-resource settings and should continue to be scaled up in Malawi.     

Acute toxicity and antioxidant responses in the water flea <Emphasis Type="Italic">Daphnia magna</Emphasis> to xenobiotics (cadmium,lead, mercury,bisphenol A,and 4-nonylphenol)

Heavy metals have adverse effects to aquatic organisms, and endocrine-disrupting chemicals (EDCs) alter the normal functioning of hormones in living organisms. In the present study, an acute toxicity test was performed to determine the EC₅₀ values in the water flea Daphnia magna exposed to Cd, Pb, Hg, 4-nonylphenol (NP) and bisphenol A (BPA) for 48 h, according to the OECD test guideline 202. The mRNA expression of Cu/Zn-SOD, Mn-SOD, and catalase (CAT) was analyzed using real time RT-PCR. The results indicate that all chemicals tested showed a negative effect on the mobility of D. magna. The 48-h EC₅₀ values were 21.0 μg/L for Cd, 694.6 μg/L for Pb, 3.8 μg/L for Hg, 18.9 μg/L for 4-NP and 8.3 mg/L for BPA. The order of toxicity based on the EC₅₀ values was as follows: Hg>4-NP>Cd>Pb>BPA. Gene expression patterns indicated that Cd and Pb increased the mRNA levels of the genes encoding three antioxidant enzymes upon exposure for 48 h. Mn-SOD and CAT mRNAs were sensitively modulated in response to Pb. In contrast, the expression of these genes was up-regulated at 24 h and then reduced at 48 h after exposure to Hg. These findings suggest that the heavy metals (Cd, Pb, and Hg) can induce oxidative stress in D. magna and that the antioxidant enzymes were sensitive to 24h-Hg and 48h-Pb exposure. A significant increase in the mRNA expression of three antioxidant enzymes was observed after exposure to 4-NP, whereas a slight modulation of Mn-SOD and CAT mRNA levels was detected in response to BPA, indicating that these genes are involved in a cellular defense system against EDCs-mediated oxidative stress.     

Combined effects of cadmium and copper on the expression of antioxidant enzyme — coding genes in the polychaete, Perinereis nuntia

Polychaetes have been used as useful model organisms for environmental pollution monitoring in aquatic sediments. Here, we investigated the combined effect of copper (50, 100 and 200 μg/L) and cadmium (50 μg/L) on the expression of antioxidant enzymecoding genes (seven GST isoforms, Mn-SOD and Cu/Zn-SOD) in the marine polychaete Perinereis nuntia by quantitative real-time RT-PCR. As a result, SOD genes, especially Cu/Zn-SOD significantly increased up to 48 h after exposure to a mixture of Cu and Cd in a time and concentration-dependent manner more than in 50 μg/L Cd alone exposure. Similar expression patterns were observed in most GST isoforms. In particular, GST-omega and GST-sigma gene expression were highly upregulated in response to a combined stress of Cd and Cu. These findings suggest that such genes would be useful as a potential molecular biomarker for monitoring of combined environmental pollutions in aquatic ecosystem.