Evaluation of the RapidHIT™ 200 System: A comparative study of its performance with Maxwell(®) DNA IQ™/Identifiler(®) Plus/ABI 3500xL workflow.

RapidHIT(™) System is a rapid DNA instrument that is capable of processing forensic samples from extraction through to capillary electrophoresis and profile generation within two hours. Evaluation of the RapidHIT(™) 200 System was conducted to examine several key performance indicators of the instrument, including reproducibility, contamination, sensitivity, versatility and the possibility of sample re-extraction. Results indicated that the RapidHIT(™) 200 System was capable of generating high quality DNA profiles which were comparable to those from the standard protocol comprising of Maxwell(®) 16 DNA IQ(™) System, Identifiler(®) Plus and ABI 3500xL. No contamination was detected during the studies. Results also showed that the instrument was able to generate DNA profiles from samples containing lower amounts of DNA (0.5 µl of blood) albeit with more allele and locus dropouts when compared to the standard protocol. The ability to process blood swabs, blood-stained FTA punches, semen swabs, buccal swabs, product of conception (POC), bone marrow, fingernail clippings and cigarette butts at a good success rate indicated the robustness and versatility of the RapidHIT(™) 200 System. Furthermore, additional alleles could be recovered via re-analysis of the failed samples using the standard protocol. In summary, our results showed that the RapidHIT(™) 200 System was able to process casework samples for the purpose of providing rapid intelligence through DNA database searches and reference matching. Confirmative DNA results can be obtained through either concurrent processing of duplicate samples via standard protocol or re-extraction of samples retrieved from the RapidHIT(™) sample cartridge.

Cyclooxygenase-1 mediated platelet reactivity in young male smokers.

BACKGROUND: The purpose of this study is to investigate the acute and chronic effects of cigarette smoking on cyclooxygenase- 1(COX-1)-mediated platelet reactivity among cigarette smokers. METHODS: The levels of collagen-induced platelet aggregation, platelet COX-1 activity, and expressions were compared between smokers and age-matched nonsmokers. In smokers, the acute effects of cigarette smoking were assessed by repeating these measurements an hour after smoking. RESULTS: Twenty-five smokers and age-matched nonsmokers (all men; mean age, 29 years) were studied. Collagen-induced platelet aggregation and plasma/urinary thromboxane B2 (TXB2) and 11-dehydroxythromboxane B2 levels were higher in cigarette smokers compared to nonsmokers. Greater expression of platelet COX-1 was observed in smokers than in nonsmokers. Among smokers, collagen-induced platelet aggregation correlated positively with platelet volume and circulating nicotine and cotinine concentrations. The levels of plasma/urinary TXB2 were significantly increased an hour after cigarette smoking. CONCLUSION: Cigarette smoking aggravates COX-1-mediated platelet reactivity in young, otherwise healthy, smoking men.

Oral zinc supplementation does not improve oxidative stress or vascular function in patients with type 2 diabetes with normal zinc levels.

OBJECTIVE: There is considerable controversy about what constitutes optimal zinc intakes in patients with type 2 diabetes mellitus. Several studies suggest that higher zinc intakes improve vascular function and decrease oxidative damage. We aimed to assess the effects of zinc supplementation using a range of reliable biomarkers of oxidative damage and vascular function in patients with type 2 diabetes. METHODS: Forty male type 2 diabetic patients were supplemented either with 240 mg/day of zinc as zinc gluconate (n=20) or with placebo (n=20) for 3 months. Blood and spot urine samples were taken at baseline, days 3 and 7, months 1, 2 and 3 during supplementation and 1 month after cessation. Serum zinc, reliable biomarkers of oxidative damage (F(2)-isoprostanes, neuroprostanes, cholesterol oxidation products, allantoin) as well as hydroxyeicosatetraenoic acid products and vascular-related indices (augmentation index, pulse wave velocity and aortic pressure) were measured. RESULTS: Despite significantly higher levels of serum zinc in the treatment group, markers of oxidative damage, levels of hydroxyeicosatetraenoic acid products and vascular indices were unchanged by zinc supplementation during the four-month study period. CONCLUSION: Improving the zinc status in patients with type 2 diabetes with normal zinc levels did not have any impact on oxidative damage and vascular function, and such supplementation may not be generally beneficial in these individuals.

Oxidative damage in ischemic stroke revealed using multiple biomarkers.

BACKGROUND AND PURPOSE: We investigated changes in oxidative damage after ischemic stroke using multiple biomarkers. METHODS: Serial blood and urine samples of ischemic stroke subjects and age-matched control subjects were assayed for F2-isoprostanes, hydroxyeicosatetraenoic acid products, F4-neuroprostanes, 24-hydroxycholesterol, allantoin, and urate. RESULTS: Sixty-six stroke subjects (mean age, 65 years; median National Institutes of Health Stroke Scale 17) and 132 control subjects were recruited. A bimodal pattern of change was observed in plasma and urinary F2-isoprostanes and plasma 24-hydroxycholesterol. The rise in plasma hydroxyeicosatetraenoic acid products, F4-neuroprostanes, and allantoin was highest 6 to 12 hours after stroke onset, whereas plasma urate was significantly lower than controls on Days 1 to 3. After adjusting for age and baseline National Institutes of Health Stroke Scale, baseline plasma esterified hydroxyeicosatetraenoic acid products (OR, 1.01; 95% CI, 1.01 to 1.02), plasma urate (1.01; 1.00 to 1.01), and plasma free F4-neuroprostanes (2.73; 1.76 to 3.93) were associated with 90-day good functional recovery (modified Rankin Scale ≤1). CONCLUSIONS: Multiple markers of oxidative damage are increased immediately after stroke and remain elevated for several days. Recognition of these temporal changes may help design better antioxidant treatment trials for acute ischemic stroke.

Biomarkers of oxidative damage in cigarette smokers: which biomarkers might reflect acute versus chronic oxidative stress?

Cigarette smoking predisposes to the development of multiple diseases involving oxidative damage. We measured a range of oxidative damage biomarkers to understand which differ between smokers and nonsmokers and if the levels of these biomarkers change further during the act of smoking itself. Despite overnight abstinence from smoking, smokers had higher levels of plasma total and esterified F(2)-isoprostanes, hydroxyeicosatetraenoic acid products (HETEs), F(4)-neuroprostanes, 7-ketocholesterol, and 24- and 27-hydroxycholesterol. Levels of urinary F(2)-isoprostanes, HETEs, and 8-hydroxy-2'-deoxyguanosine were also increased compared with age-matched nonsmokers. Several biomarkers (plasma free F(2)-isoprostanes, allantoin, and 7ß-hydroxycholesterol and urinary F(2)-isoprostane metabolites) were not elevated. The smokers were then asked to smoke a cigarette; this acute smoking elevated plasma and urinary F(2)-isoprostanes, plasma allantoin, and certain cholesterol oxidation products compared to presmoking levels, but not plasma HETEs or urinary 8-hydroxy-2'-deoxyguanosine. Smokers showed differences in plasma fatty acid composition. Our findings confirm that certain oxidative damage biomarkers are elevated in smokers even after a period of abstinence from smoking, whereas these plus some others are elevated after acute smoking. Thus, different biomarkers do not measure identical aspects of oxidative stress.

Oxidative damage in Parkinson disease: Measurement using accurate biomarkers.

Oxidative damage has been implicated in the pathogenesis of Parkinson disease (PD) but the literature data are confusing. Using products of lipid and DNA oxidation measured by accurate methods, we assessed the extent of oxidative damage in PD patients. The levels of plasma F(2)-isoprostanes (F(2)-IsoPs), hydroxyeicosatetraenoic acid products (HETEs), cholesterol oxidation products, neuroprostanes (F(4)-NPs), phospholipase A(2) (PLA(2)) and platelet activating factor-acetylhydrolase (PAF-AH) activities, urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG), and serum high-sensitivity C-reactive protein were compared in 61 PD patients and 61 age-matched controls. The levels of plasma F(2)-IsoPs, HETEs, 7beta-and 27-hydroxycholesterol, 7-ketocholesterol, F(4)-NPs, and urinary 8-OHdG were elevated, whereas the levels of plasma PLA(2) and PAF-AH activities were lower, in PD patients compared to controls (p< 0.05). The levels of plasma F(2)-IsoPs, HETEs, and urinary 8-OHdG were higher in the early stages of PD (p trend< 0.05). There was a significant negative correlation between the cumulative intake of levodopa and urinary 8-OHdG (r= -0.305, p= 0.023) and plasma total HETEs (r= -0.285, p= 0.043). Oxidative damage markers are systemically elevated in PD, which may give clues about the relation of oxidative damage to the onset and progression of PD.