25 resultados para blood serum


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Epidemiological studies show that elevated plasma levels of advanced glycation end products (AGEs) are associated with diabetes, kidney disease, and heart disease. Thus AGEs have been used as disease progression markers. However, the effects of variations in biological sample processing procedures on the level of AGEs in plasma/serum samples have not been investigated. The objective of this investigation was to assess the effect of variations in blood sample collection on measured Ne_(carboxy-methyl)lysine (CML), the best characterised AGE, and its homolog, Ne_(carboxyethyl)lysine (CEL). The investigation examined the effect on CML and CEL of different blood collection tubes, inclusion of a stabilising cocktail, effect of freeze thaw cycles, different storage times and temperatures, and effects of delaying centrifugation on a pooled sample from healthy volunteers. CML and CEL were measured in extracted samples by ultra_performance liquid chromatography-tandem mass spectrometry. Median CML and CEL ranged from 0.132 to 0.140 mM/M lys and from 0.053 to 0.060 mM/M lys, respectively. No significant difference was shown CML or CEL in plasma/serum samples. Therefore samples collected as part of epidemiological studies that do not undergo specific sample treatment at collection are suitable for measuring CML and CEL.

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Aim: To determine if serum pigment epithelium-derived factor (PEDF) levels in Type 2 diabetes are related to vascular risk factors and renal function. Methods: PEDF was quantified by ELISA in a cross-sectional study of 857 male Veterans Affairs Diabetes Trial (VADT) subjects, and associations with cardiovascular risk factors and renal function were determined. In a subset (n = 246) in whom serum was obtained early in the VADT (2.0 ± 0.3 years post-randomization), PEDF was related to longitudinal changes in renal function over 3.1 years. Results: Cross-sectional study: In multivariate regression models, PEDF was positively associated with serum triglycerides, waist-to-hip ratio, serum creatinine, use of ACE inhibitors or angiotensin receptor blockers, and use of lipid-lowering agents; it was negatively associated with HDL-C (all p < 0.05). Longitudinal study: PEDF was not associated with changes in renal function over 3.1 years (p > 0.09). Conclusions: Serum PEDF in Type 2 diabetic men was cross-sectionally associated with dyslipidemia, body habitus, use of common drugs for blood pressure and dyslipidemia, and indices of renal function; however, PEDF was not associated with renal decline over 3.1 years.

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Dietary flavonoid intake, especially berry flavonoids, has been associated with reduced risks of cardiovascular disease (CVD) in large prospective cohorts. Few clinical studies have examined the effects of dietary berries on CVD risk factors. We examined the hypothesis that freeze-dried strawberries (FDS) improve lipid and lipoprotein profiles and lower biomarkers of inflammation and lipid oxidation in adults with abdominal adiposity and elevated serum lipids. In a randomized dose-response controlled trial, 60 volunteers [5 men and 55 women; aged 49 ± 10 y; BMI: 36 ± 5 kg/m2 (means ± SDs)] were assigned to consume 1 of the following 4 beverages for 12 wk: 1) low-dose FDS (LD-FDS; 25 g/d); 2) low-dose control (LD-C); 3) high-dose FDS (HD-FDS; 50 g/d); and 4) high-dose control (HD-C). Control beverages were matched for calories and total fiber. Blood draws, anthropometrics, blood pressure, and dietary data were collected at screening (0 wk) and after 12-wk intervention. Dose-response analyses revealed significantly greater decreases in serum total and LDL cholesterol and nuclear magnetic resonance (NMR)–derived small LDL particle concentration in HD-FDS [33 ± 6 mg/dL, 28 ± 7 mg/dL, and 301 ± 78 nmol/L, respectively (means ± SEMs)] vs. LD-FDS (−3 ± 11 mg/dL, −3 ± 9 mg/dL, and −28 ± 124 nmol/L, respectively) over 12 wk (0–12 wk; all P < 0.05). Compared with controls, only the decreases in total and LDL cholesterol in HD-FDS remained significant vs. HD-C (0.7 ± 12 and 1.4 ± 9 mg/dL, respectively) over 12 wk (0–12 wk; all P < 0.05). Both doses of strawberries showed a similar decrease in serum malondialdehyde at 12 wk (LD-FDS: 1.3 ± 0.2 μmol/L; HD-FDS: 1.2 ± 0.1 μmol/L) vs. controls (LD-C: 2.1 ± 0.2 μmol/L; HD-C: 2.3 ± 0.2 μmol/L) (P < 0.05). In general, strawberry intervention did not affect any measures of adiposity, blood pressure, glycemia, and serum concentrations of HDL cholesterol and triglycerides, C-reactive protein, and adhesion molecules. Thus, HD-FDS exerted greater effects in lowering serum total and LDL cholesterol and NMR-derived small LDL particles vs. LD-FDS in the 12-wk study. These findings warrant additional investigation in larger trials. This trial was registered at clinicaltrials.gov as NCT01883401.

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The present study assessed whether increased fruit and vegetable (F&V) intake reduced the concentrations of the inflammatory marker serum amyloid A (SAA) in serum, HDL2 and HDL3 and whether the latter reduction influenced any of the functional properties of these HDL subfractions. The present study utilised samples from two previous studies: (1) the FAVRIT (Fruit and Vegetable Randomised Intervention Trial) study - hypertensive subjects (systolic blood pressure (BP) range 140-190 mmHg; diastolic BP range 90-110 mmHg) were randomised to receive a 1-, 3- or 6-portion F&V/d intervention for 8 weeks, and (2) the ADIT (Ageing and Dietary Intervention Trial) study - older subjects (65-85 years) were randomised to receive a 2- or 5-portion F&V/d intervention for 16 weeks. HDL2 and HDL3 were isolated by rapid ultracentrifugation. Measurements included the following: serum high-sensitive C-reactive protein (hsCRP) by an immunoturbidimetric assay; serum IL-6 and E-selectin and serum-, HDL2- and HDL3-SAA by ELISA procedures; serum-, HDL2- and HDL3-cholesterol ester transfer protein (CETP) activity by a fluorometric assay. Although the concentrations of hsCRP, IL-6 and E-selectin were unaffected by increasing F&V intake in both studies (P>0·05 for all comparisons), those of SAA in HDL3 decreased in the FAVRIT cohort (P= 0·049) and those in HDL2 and HDL3 decreased in the ADIT cohort (P= 0·035 and 0·032), which was accompanied by a decrease in the activity of CETP in HDL3 in the FAVRIT cohort (P= 0·010) and in HDL2 in the ADIT cohort (P= 0·030). These results indicate that SAA responds to increased F&V intake, while other inflammatory markers remain unresponsive, and this leads to changes in HDL2 and HDL3, which may influence their antiatherogenic potential. Overall, the present study provides tangible evidence of the effectiveness of increased F&V intake, which may be of use to health policy makers and the general public.

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Epidemiological studies show that elevated plasma levels of advanced glycation end products (AGEs) are associated with diabetes, kidney disease, and heart disease. Thus AGEs have been used as disease progression markers. However, the effects of variations in biological sample processing procedures on the level of AGEs in plasma/serum samples have not been investigated. The objective of this investigation was to assess the effect of variations in blood sample collection on measured N (ε)-(carboxymethyl)lysine (CML), the best characterised AGE, and its homolog, N (ε)-(carboxyethyl)lysine (CEL). The investigation examined the effect on CML and CEL of different blood collection tubes, inclusion of a stabilising cocktail, effect of freeze thaw cycles, different storage times and temperatures, and effects of delaying centrifugation on a pooled sample from healthy volunteers. CML and CEL were measured in extracted samples by ultra-performance liquid chromatography-tandem mass spectrometry. Median CML and CEL ranged from 0.132 to 0.140 mM/M lys and from 0.053 to 0.060 mM/M lys, respectively. No significant difference was shown CML or CEL in plasma/serum samples. Therefore samples collected as part of epidemiological studies that do not undergo specific sample treatment at collection are suitable for measuring CML and CEL.

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Intake of heterocyclic amines (HCAs, carcinogens produced during cooking of meat/fish, the most abundant being PhIP, DiMeIQx and MeIQx) is influenced by many factors including type/thickness of meat and cooking method/temperature/duration. Thus, assessment of HCA dietary exposure is difficult. Protein adducts of HCAs have been proposed as potential medium-term biomarkers of exposure, e.g. PhIP adducted to serum albumin or haemoglobin. However, evidence is still lacking that HCA adducts are viable biomarkers in humans consuming normal diets. The FoodCAP project, supported by World Cancer Research Fund, developed a highly sensitive mass spectrometric method for hydrolysis, extraction and detection of acid-labile HCAs in blood and assessed their validity as biomarkers of exposure. Multiple acid/alkaline hydrolysis conditions were assessed, followed by liquid-liquid extraction, clean-up by cation-exchange SPE and quantification by UPLC-ESI-MS/ MS. Blood was analysed from volunteers who completed food diaries to estimate HCA intake based on the US National Cancer Institute’s CHARRED database. Standard HCAs were recovered quantitatively from fortified blood. In addition, PhIP/MeIQx adducts bound to albumin and haemoglobin prepared in vitro using a human liver microsome system were also detectable in blood fortified at low ppt concentrations. However, except for one sample (5pg/ml PhIP), acid-labile PhIP, 7,8-DiMeIQx, 4,8-DiMeIQx and MeIQx were not observed above the 2pg/ml limit of detection in plasma (n=35), or in serum, whole blood or purified albumin, even in volunteers with high meat consumption (nominal HCA intake >2µg/day). It is concluded that HCA blood protein adducts are not viable biomarkers of exposure. Untargeted metabolomic analyses may facilitate discovery of suitable markers.

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Inflammatory atherosclerosis is increased in subjects with type 1 diabetes mellitus (T1DM). Normally high-density lipoproteins(HDL) protect against atherosclerosis; however, in the presence of serum amyloid-A- (SAA-) related inflammation this propertymay be reduced. Fasting blood was obtained from fifty subjects with T1DM, together with fifty age, gender and BMI matchedcontrol subjects. HDL was subfractionated into HDL2 and HDL3 by rapid ultracentrifugation. Serum-hsCRP and serum-, HDL2-,and HDL3-SAA were measured by ELISAs. Compared to control subjects, SAA was increased in T1DM subjects, nonsignificantly inserum (P = 0.088), and significantly in HDL2 (P  = 0.003) and HDL3 (P  = 0.005). When the T1DM group were separated accordingto mean HbA1c (8.34%), serum-SAA and HDL3-SAA levels were higher in the T1DM subjects with HbA1c ≥ 8.34%, compared towhen HbA1c was <8.34% (P  < 0.05). Furthermore, regression analysis illustrated, that for every 1%-unit increase in HbA1c, SAAincreased by 20% and 23% in HDL2 and HDL3, respectively, independent of BMI. HsCRP did not differ between groups (P  > 0.05).This cross-sectional study demonstrated increased SAA-related inflammation in subjects with T1DM that was augmented by poorglycaemic control. We suggest that SAA is a useful inflammatory biomarker in T1DM, which may contribute to their increasedatherosclerosis risk.

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Secondary or late graft failure has been defined as the development of inadequate marrow function after initial engraftment has been achieved. We describe a case of profound marrow aplasia occurring 13 years after sibling allogeneic bone marrow transplantation for chronic myeloid leukaemia (CML) in first chronic phase. Although the patient remained a complete donor chimera, thereby suggesting that an unselected infusion of donor peripheral blood stem cells (PBSC) or bone marrow might be indicated, the newly acquired aplasia was thought to be immune in aetiology and some immunosuppression was therefore considered appropriate. Rapid haematological recovery was achieved after the infusion of unselected PBSC from the original donor following conditioning with anti-thymocyte globulin (ATG).

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Currently, there are no biomarkers which can identify patients with an increased risk of developing urothelial cancer as a result of occupational chemical exposure. The aim of this study was to evaluate the relationships between final diagnosis and 22 biomarkers measured in urine, serum and plasma collected from 156 hematuric patients. Fourteen of the 80 patients (17.5%) with urothelial cancer and 13/76 (17.1%) of the controls were deemed to have a history of chemical exposure. We applied Fisher's exact tests to explore associations between chemical exposure and final diagnosis, and tumor stage and grade, where applicable; ANOVA and t-test to compare age across patients with and without chemical exposure; and Zelen's exact test to evaluate relationships across final diagnosis, chemical exposure and smoking. Following pre-selection of biomarkers using Lasso, we identified biomarkers with differential levels across patients with and without chemical exposure using Welch's t-test. Using a one-sided t-test and considering multiple testing using FDR, we observed that TM levels in urine were significantly higher in samples from patients with a history of chemical exposure regardless of their diagnosis as control or urothelial cancer (one-sided t-test, pUC = 0.014 and pCTL = 0.043); in the presence of dipstick protein and when urinary pH levels ≤ 6 (p = 0.003), but not in the presence of dipstick blood (p = 0.115). Urothelial cancer patients with a history of chemical exposure were significantly younger (64.1 years) than those without chemical exposure (70.2 years) (one-sided t-test p-value = 0.012); and their tumors were higher grade (Fisher's exact test; p = 0.008). There was a strong association between a history of chemical exposure and smoking in urothelial cancer patients (Zelen's exact test; p = 0.025). Elevated urinary thrombomodulin levels could have the potential to identify chemical exposure in hematuric patients at high risk of developing urothelial cancer.

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Current treatment strategies for the treatment of brain tumor have been hindered primarily by the presence of highly lipophilic insurmountable blood-brain barrier (BBB). The purpose of current research was to investigate the efficiency of engineered biocompatible polymeric nanoparticles (NPs) as drug delivery vehicle to bypass the BBB and enhance biopharmaceutical attributes of anti-metabolite methotrexate (MTX) encapsulated NPs. The NPs were prepared by solvent diffusion method using cationic bovine serum albumin (CBA), and characterized for physicochemical parameters such as particle size, polydispersity index, and zeta-potential; while the surface modification was confirmed by FTIR, and NMR spectroscopy. Developed NPs exhibited zestful relocation of FITC tagged NPs across BBB in albino rats. Further, hemolytic studies confirmed them to be non-toxic and biocompatible as compared to free MTX. In vitro cytotoxicity assay of our engineered NPs on HNGC1 tumor cells proved superior uptake in tumor cells; and elicited potent cytotoxic effect as compared to plain NPs and free MTX solution. The outcomes of the study evidently indicate the prospective of CBA conjugated poly (D,L-lactide-co-glycolide) (PLGA) NPs loaded with MTX in brain cancer bomber with amplified capability to circumvent BBB.