Oxidative status and reduced glutathione levels in premature coronary artery disease and coronary artery disease

Identifying patients at risk of developing premature coronary artery disease (PCAD) which occurs at age below 45 years old and constitutes approximately 7–10% of coronary artery disease (CAD) worldwide remains a problem. Oxidative stress has been proposed as a crucial step in the early development of PCAD. This study was conducted to determine the oxidative status of PCAD in comparison to CAD patients. PCAD (<45 years old) and CAD (>60 years old) patients were recruited with age-matched controls (n?=?30, each group). DNA damage score, plasma malondialdehyde (MDA) and protein carbonyl content were measured for oxidative damage markers. Antioxidants such as erythrocyte glutathione (GSH), oxidised glutathione (GSSG), and glutathione peroxidase activity (GPx), superoxide dismutase (SOD) and catalase (CAT) were also determined. DNA damage score and protein carbonyl content were significantly higher in both PCAD and CAD when compared to age-matched controls while MDA level was increased only in PCAD (p<.05). In contrast, GSH, GSH/GSSG ratio, α-tocotrienol isomer, and GPx activity were significantly decreased, but only in PCAD when compared to age-matched controls. The decrease in GSH was associated with PCAD (OR?=?0.569 95%CI [0.375???0.864], p?=?.008) and cut-off values of 6.69?μM with areas under the ROC curves (AUROC) 95%CI: 0.88 [0.80–0.96] (sensitivity of 83.3%; specificity of 80%). However, there were no significant differences in SOD and CAT activities in all groups. A higher level of oxidative stress indicated by elevated MDA levels and low levels of GSH, α-tocotrienol and GPx activity in patients below 45 years old may play a role in the development of PCAD and has potential as biomarkers for PCAD.     

Severity-Based Adaptation with Limited Data for ASR to Aid Dysarthric Speakers

Automatic speech recognition (ASR) is currently used in many assistive technologies, such as helping individuals with speech impairment in their communication ability. One challenge in ASR for speech-impaired individuals is the difficulty in obtaining a good speech database of impaired speakers for building an effective speech acoustic model. Because there are very few existing databases of impaired speech, which are also limited in size, the obvious solution to build a speech acoustic model of impaired speech is by employing adaptation techniques. However, issues that have not been addressed in existing studies in the area of adaptation for speech impairment are as follows: (1) identifying the most effective adaptation technique for impaired speech; and (2) the use of suitable source models to build an effective impaired-speech acoustic model. This research investigates the above-mentioned two issues on dysarthria, a type of speech impairment affecting millions of people. We applied both unimpaired and impaired speech as the source model with well-known adaptation techniques like the maximum likelihood linear regression (MLLR) and the constrained-MLLR(C-MLLR). The recognition accuracy of each impaired speech acoustic model is measured in terms of word error rate (WER), with further assessments, including phoneme insertion, substitution and deletion rates. Unimpaired speech when combined with limited high-quality speech-impaired data improves performance of ASR systems in recognising severely impaired dysarthric speech. The C-MLLR adaptation technique was also found to be better than MLLR in recognising mildly and moderately impaired speech based on the statistical analysis of the WER. It was found that phoneme substitution was the biggest contributing factor in WER in dysarthric speech for all levels of severity. The results show that the speech acoustic models derived from suitable adaptation techniques improve the performance of ASR systems in recognising impaired speech with limited adaptation data.     

Hexavalent molybdenum reduction to Mo-blue by <Emphasis Type="Italic">Acinetobacter calcoaceticus</Emphasis>

A local molybdenum-reducing bacterium was isolated and tentatively identified as Acinetobacter calcoaceticus strain Dr.Y12 based on carbon utilization profiles using Biolog GN plates and 16S rDNA comparative analysis. Molybdate reduction was optimized under conditions of low dissolved oxygen (37 °C and pH 6.5). Of the electron donors tested, glucose, fructose, maltose and sucrose supported molybdate reduction after 1 d of incubation, glucose and fructose supporting the highest Mo-blue production. Optimum Mo-blue production was reached at 20 mmol/L molybdate and 5 mmol/L phosphate; increasing the phosphate concentrations inhibited the production. An increase in an overall absorption profiles, especially at peak maximum at 865 nm and the shoulder at 700 nm, was observed in direct correlation with the increased in Mo-blue amounts. Metal ions, such as chromium, cadmium, copper, mercury and lead (2 mmol/L final concentration) caused ≈88, 53, 80, 100, and 20 % inhibition, respectively. Respiratory inhibitors, such as antimycin A, rotenone, sodium azide and cyanide showed in this bacterium no inhibition of the Mo-blue production, suggesting that the electron transport system is not a site of molybdate reduction.     

Haplotype and network analysis of island flying fox (Pteropus hypomelanus) using D-loop region of mitochondrial DNA to confirm subspecies designation

Mammal Research - Taxonomic confusion among island flying foxes (Pteropus hypomelanus) still in debate as in the lack of further genetic studies that describe subspecies validity needs...     

Development of a Polygonum minus cell suspension culture system and analysis of secondary metabolites enhanced by elicitation

Polygonum minus has been reported to contain valuable metabolites and to date, there is no report on using cell culture technique for metabolite production in P. minus. Naphthalene acetic acid (NAA) concentrations in the range of 2–6 mg L^?1 were used in a matrix of combinations with dichlorophenoxyacetic acid (2,4-D) concentrations in the range of 2–10 mg L^?1 as plant growth regulators (PGRs) to induce callus cultures. Media that were supplemented with 2 mg L^?1 2,4-D + 4 mg L^?1 NAA, 2 mg L^?1 2,4-D + 6 mg L^?1 NAA and 6 mg L^?1 2,4-D + 8 mg L^?1 NAA were effective for callus induction (93.3 % of the explants produced callus). To establish cell culture, the best growth was obtained from medium that was supplemented with 1 mg L^?1 2,4-D + 2 mg L^?1 NAA. From a 1-g inoculum size, the fresh weight increases exponentially after 5–10 days of culture, and a 26.71 g maximum fresh weight was obtained after 25 days of culture. The cell culture medium was then analyzed using gas chromatography–mass spectrometry (GC–MS). Jasmonic acid (100, 50, 25 and 5 μM), salicylic acid (100, 50, 25 and 5 μM), yeast extract (500, 250 and 100 mg L^?1) and glass beads were used in this research as elicitors. The cell cultures were then incubated with the different elicitors for 1, 2, 3 and 4 days. Several compounds with high peak area percentages were detected, including 2-furancarboxaldehyde, 5-hydroxymethyl, furfural, and 2-cyclopenten-1-one, 2-hydroxy. These results show the diversity of metabolites released by P. minus cell into the culture medium under control conditions.     

Screening of soy and milk protein hydrolysates for their ability to activate the CCK1 receptor

The cholecystokinin receptor-type 1 (CCK1R) is a G-protein coupled receptor localized in the animal gastrointestinal tract. Receptor activation by the natural peptide ligand CCK leads to a feeling of satiety. In this study, hydrolysates from soy and milk proteins were evaluated for their potential to activate the CCK1R, assuming that bioactive peptides with a satiogenic effect can be used as an effective therapeutic strategy for obesity. Different protein hydrolysates were screened with a cell-based bioassay, which relies on the generation of a fluorescent signal upon receptor activation. Fluorescence was monitored using a fluorescence plate reader and confocal microscopy. Results from the fluorescence plate reader were biased by background autofluorescence of the protein hydrolysate matrices, which makes the fluorescence plate reader inappropriate for the evaluation of complex formulations. Measurements with the confocal microscope resulted in reliable and specific results. The latter approach showed that the gastrointestinal digested 7S fraction of soy protein demonstrates CCK1R activity.     

Optimization of ultraviolet ozone treatment process for improvement of polycaprolactone (PCL) microcarrier performance

Growing cells on microcarriers may have overcome the limitation of conventional cell culture system. However, the surface functionality of certain polymeric microcarriers for effective cell attachment and growth remains a challenge. Polycaprolactone (PCL), a biodegradable polymer has received considerable attention due to its good mechanical properties and degradation rate. The drawback is the non-polar hydrocarbon moiety which makes it not readily suitable for cell attachment. This report concerns the modification of PCL microcarrier surface (introduction of functional oxygen groups) using ultraviolet irradiation and ozone (UV/O₃) system and investigation of the effects of ozone concentration, the amount of PCL and exposure time; where the optimum conditions were found to be at 60,110.52 ppm, 5.5 g PCL and 60 min, respectively. The optimum concentration of carboxyl group (COOH) absorbed on the surface was 1495.92 nmol/g and the amount of gelatin immobilized was 320 ± 0.9 µg/g on UV/O₃ treated microcarriers as compared to the untreated (26.83 ± 3 µg/g) microcarriers. The absorption of functional oxygen groups on the surface and the immobilized gelatin was confirmed with the attenuated total reflectance Fourier transformed infrared spectroscopy (ATR-FTIR) and the enhancement of hydrophilicity of the surface was confirmed using water contact angle measurement which decreased (86.93°–49.34°) after UV/O₃ treatment and subsequently after immobilization of gelatin. The attachment and growth kinetics for HaCaT skin keratinocyte cells showed that adhesion occurred much more rapidly for oxidized surfaces and gelatin immobilized surface as compared to untreated PCL.