Individual and Combined Associations of Cognitive and Mobility Limitations on Mortality Risk in Older Adults

Objective

To evaluate the potential independent and combined associations of cognitive and mobility limitations on risk of all-cause mortality in a representative sample of the US older adult population who, at baseline, were free of cardiovascular and cerebrovascular disease.

血管紧张素转换酶抑制剂肾保护作用的有效剂量探讨

目的　探讨ACEI肾保护作用的有效剂量。方法　原发性肾小球疾病患者 15 4例。分别实施Captopril、Cilazapril和Enalapril各高、低两个剂量组以及作为对照给予Amlodipine治疗 4个月。治疗前、后每月检测平均动脉压、尿蛋白、尿白蛋白排泄率、尿钠、尿尿素氮和肾功能 ,并检测患者ACE基因表型。结果　①各组间ACE基因表型分布和蛋白质、食盐摄入量无明显差别 ;②三种ACEI的高、低剂量组间的抗尿蛋白作用和对肾功能的影响无明显差别。结论　对原发性肾小球疾病患者低剂量的ACEI也具备良好的肾保护作用。     

Phenols of virgin olive oil protects nuclear DNA against oxidative damage in HeLa cells

Oxidative DNA damage is an inescapable consequence for cells constantly exposed to oxidative stress derived from normal metabolic processes and from environmental factors. Phenolic compounds, which have strong antioxidant activity, prevent DNA damage by protecting the cells against harmful effects of oxidative stress. In this study, the effect of virgin olive oil phenolic extract (OOPE) was investigated on H₂O₂-induced mitochondrial DNA (mtDNA) and nuclear DNA (nDNA) damage in HeLa cells. DNA damage was assessed in mitochondria and two nuclear regions by using quantitative PCR (QPCR) assay. The cells were pre-treated with non-cytotoxic doses of OOPE for 4 h, and DNA damage was determined. OOPE alone does not change the steady-state level of DNA damage. The oxidative stress generated with 750 μM H₂O₂ caused two times greater damages in mtDNA compared to nDNA, which included the nonexpressed β-globin region (1.507 ± 0.110 lesions/10 kb) and the expressed APEX1 gene (1.623 ± 0.243 lesions/10 kb) with respect to the control region. When cells were preincubated with OOPE for 4 h, nDNA damage under stress condition was completely inhibited; however, mtDNA damage was not affected by this procedure. These results suggest that OOPE has a protective effect against nDNA damage in HeLa cells.     

Assessment of PCBs exposure in human hair using double focusing high resolution mass spectrometry and single quadrupole mass spectrometry

Polychlorinated biphenyls (PCBs) levels were assessed in human hair samples, originating from two main agricultural regions of Greece. The analysis was performed by gas chromatography-mass spectrometry (GC-MS) and gas chromatography-double focusing high resolution mass spectrometry (GC-DFHRMS). The main analytical procedure involved hair decontamination, solid-liquid extraction and cleanup steps. The recoveries of PCBs ranged from 71.2% to 101.6%, with accuracies greater than 87.5% and the between-run precisions (%RSD) lower than 25% for all analytes. Differences in the frequencies of detection and the median values of PCBs were detected between the examined regions and between the applied analytical techniques. All Peloponnesus' hair examined samples were found positive for each examined PCB, while the percentage of the total positive samples ranged from 86.1% (for PCB 138) to 94.4% (for PCB 28 and 153 congeners) using GC-DFHRMS. The Cretan hair samples were less contaminated (SUM PCBs=0.61 and 1.47pg/mg) unlike the Peloponnesus' samples (SUM PCBs=24.68 and 38.74pg/mg) measured by GC-DFHRMS and GC-MS, respectively. PCBs with high chlorination gave lower concentration values compared to low chlorination PCBs in both populations. No significant differences were observed between women and men. The GC-DFHRMS technique provided higher percentage of positive samples and low PCBs median values, due to higher sensitivity and interferences from isobaric ions in the GC-MS technique and is therefore considered as a powerful tool for such assessments in hair specimens.     

Cannabis induces different cognitive changes in schizophrenic patients and in healthy controls

It is known that 60 to 80% of schizophrenic patients show deficits in cognition. There may be an increase in these deficits as a result of additional regular use of cannabis. The aim of the study was to evaluate the effect of chronic cannabis consumption on the cognitive functions of schizophrenic patients and healthy control subjects after a minimum abstinence time of 28 days. The study sample consisted of 39 schizophrenics (19 cannabis-abusers and 20 non-abusers) and 39 healthy controls (18 cannabis-abusers, 21 non-abusers). In a 2x2-factorial design (Diagnostic Groups [healthy controls, schizophrenic patients]xCannabis abuse [without, with]) with diagnostic group and cannabis consumption considered between-subject factors) we tested the hypothesis that dually diagnosed patients (i.e. suffering both from schizophrenia and cannabis abuse) perform worse in neuropsychological tests than schizophrenic patients without cannabis abuse. On the whole, schizophrenic patients performed worse than healthy control subjects. Surprisingly, rather than deteriorating neuropsychological performance, regular cannabis abuse prior to the first psychotic episode improved cognition in some tests. This was even more pronounced when regular consumption started before the age of 17. On the other hand, cannabis use deteriorated test performance in healthy controls, especially in cases when regular consumption started before the age of 17. To sum up, regular cannabis abuse has a different effect on cognitive function in schizophrenic patients and healthy controls.     

海星醇提取物对疾病引起的胃肠动力障碍的改善作用

目的考察海星用体积分数为60%、70%的乙醇溶液沉淀等量混合提取物(60%and 70%e-quivalent ethanol sediments extract of asterias,HX)对糖尿病胃轻瘫小鼠,利血平抑郁小鼠及应激小鼠胃肠动力障碍的改善作用。方法采用小鼠胃排空和小肠推进的实验方法。结果连续6 d灌胃给予HX(1.3、2.6、3.9 g.kg-1),可明显改善糖尿病胃轻瘫小鼠的胃排空延迟和小肠推进减慢;HX(1.3、2.6 g.kg-1)可改善利血平所致抑郁小鼠的胃排空延迟和小肠推进减慢,HX(1.3 g.kg-1)对应激引起的小鼠胃排空延迟和小肠推进的减慢均有改善作用。结论HX可改善糖尿病、抑郁和应激引发的胃肠动力障碍。提示海星作为一种新型的调节胃肠动力的海洋药物,在疾病伴随的胃肠动力障碍的治疗中具有广阔的开发前景。     

Anti-inflammatory, antioxidant, anti-tyrosinase and phenolic contents of four Podocarpus species used in traditional medicine in South Africa

Ethnopharmacological relevance

Species of Podocarpus are used traditionally in their native areas for the treatment of fevers, asthma, coughs, cholera, chest complaints, arthritis, rheumatism, venereal diseases and distemper in dogs.

Aims of the study

To investigate the antioxidant, anti-inflammatory and anti-tyrosinase activities of four Podocarpus species, Podocarpus elongatus, Podocarpus falcatus, Podocarpus henkelii and Podocarpus latifolius, used in traditional medicine in South Africa. Phytochemical analysis to determine the phenolic contents was also carried out.

Materials and methods

DPPH, FRAP and β-carotene-linoleic acid assays were used to determine the antioxidant/radical scavenging activities of these species. Anti-inflammatory activity of these species was assayed against two cyclooxygenase enzymes (COX-1 and COX-2). Tyrosinase inhibition activity was analysed using the modified dopachrome method with l-DOPA as the substrate. Phenolics were quantitatively determined using spectrophotometric methods.

Results

Stems of Podocarpus latifolius exhibited the lowest EC₅₀ (0.84 μg/ml) inhibition against DPPH. The percentage antioxidant activity based on the bleaching rate of β-carotene ranged from 96% to 99%. High ferric reducing power was observed in all the extracts. For COX-1, the lowest EC₅₀ value was exhibited by stem extracts of Podocarpus elongatus (5.02 μg/ml) and leaf extract of Podocarpus latifolius showed the lowest EC₅₀ against COX-2 (5.13 μg/ml). All extracts inhibited tyrosinase activity in a dose-dependent manner with stem extract of Podocarpus elongatus being the most potent with an EC₅₀ value of 0.14 mg/ml. The total phenolic content ranged from 2.38 to 6.94 mg of GAE/g dry sample.

Conclusion

The significant pharmacological activities observed support the use of these species in traditional medicine and may also be candidates in the search for modern pharmaceuticals in medicine, food and cosmetic industries.     

Hydrophobicity-dependent QSARs to predict the toxicity of perfluorinated carboxylic acids and their mixtures

Perfluorinated carboxylic acids (PFCAs) have wide industrial applications because of their unique physicochemical characteristics. However, data on the toxicity of much of this chemical class is lacking, particularly with regard to mixture toxicity. In this study, the toxicity of individual PFCAs and their mixtures to Photobacterium phosphoreum were observed. There was a tendency of increasing toxicity from C3 to C14 PFCA and a tendency of decreasing toxicity from C14 to C18 PFCA because of “the maximum tolerance of the cell membrane”. Using the equivalent log K_OW (octanol–water partition coefficient) and log K_SD (C₁₈-Empore™ disks/water partition coefficient), two linear quantitative structure–activity relationship (QSAR) models were formulated. This indicated both K_SD and K_OW can describe the hydrophobicity of a single chemical. However, for the PFCA mixtures, K_MD is the more reasonable parameter than K_owmix to describe the hydrophobicity because only the equivalent log K_MD could be used to predict the mixture toxicity.