Microbiological assessment of arterial allografts processed in a tissue bank.

The transmission of microbial infection through tissue allografts is one of the main risks that must be controlled in tissue banks. Therefore, microbiological monitoring controls and validated protocols for the decontamination of tissues during processing have been implemented. This study is based on the evaluation of data from microbiological cultures of arteries (mainly long peripheral arteries) processed in the tissue bank of Valencia (Spain). Donors' profile, pre- and post-disinfection tissue samples were assessed. The presence of residual antibiotics in disinfected tissues was determined and the antimicrobial potential of these tissues was tested. Our overall contamination rate was 23.69%, with a disinfection rate (after antibiotic incubation) of 87.5%. Most (76.09%) of the microbial contaminants were identified as Gram positive. Arterial allografts collected from body sites affected by prior organ removal showed higher risk of contamination. Only vancomycin was detected as tissue release. The antimicrobial effect on Candida albicans was lower than that for bacterial species. Risk assessment for microbial contamination suggested the donor's skin and the environment during tissue collection as the main sources for allograft contamination. Antibiotic-disinfected arterial allografts showed antimicrobial potential.

Impact of using artemisinin-based combination therapy (ACT) in the treatment of uncomplicated malaria from Plasmodium falciparum in a non-endemic zone.

BACKGROUND: Artemisinin-based combination therapy (ACT) has been adopted by the World Health Organization as a first-line treatment for uncomplicated Plasmodium falciparum malaria. In endemic regions, it has proven more effective in treating the disease, and even in reducing its transmission. Nonetheless, there is a scarcity of studies carried out in non-endemic areas on imported uncomplicated malaria. METHODS: This is a retrospective, observational study performed on patients diagnosed and admitted with uncomplicated P. falciparum malaria between 2004 and 2015. The objective was to compare the parasite clearance period and the average hospital length of stay for patients treated with ACT vs those receiving other treatment regimens. RESULTS: Eighty-five patients were included in the study. Fifty-one received ACT treatment (dihydroartemisinin-piperaquine) and thirty-four patients were treated with quinine sulfate+doxycycline or atovaquone/proguanil. The parasite clearance period was shorter in the group of patients treated with ACT compared to those receiving other treatment types: 24 h (IQR 24) vs 48 h (IQR 48), p < 0.01. The average hospital stay was also shorter in the ACT group with respect to the second group: 2.67 days (IQR 1.08) vs 3.96 days (IQR 2.87), p < 0.001. A mild case of hepatitis was registered in the group treated with ACT. CONCLUSIONS: ACT treatment of admitted hospital patients with imported uncomplicated malaria from P. falciparum reduced the days spent hospitalized as well as producing a more rapid parasite clearance compared to classic treatment. In spite of being treated with safe medications, one has to be alert to possible adverse effects such as hepatitis and delayed haemolytic anaemia.

Thiolated DAB dendrimer/ZnSe nanoparticles for C-reactive protein recognition in human serum.

A nanocomposite obtained by a thiol DAB-dendrimer (generation 5), coated with fluorescent ZnSe quantum dots, was successfully synthesized for the selective recognition of C-reactive protein. The procedure presented was carried out by a novel, cheap and non-toxic bottom up synthesis. The nanocomposite showed an excitation at 180 nm, with two emission bands at 411 and 465 nm, with a full-width at half-maximum of 336 nm. The Stokes shift was influenced by the presence of coating molecules and the intensity was dependent on pH due to the presence of a charge transfer process. The transmission electron microscopy images demonstrated that the spherical nanoparticles obtained displayed a regular shape of 30 nm size. The fluorescence intensity was markedly quenched by the presence of C-reactive protein, with a dynamic Stern-Volmer constant of 0.036 M(-1). The quenching profile shows that about 51% of the ZnSe QDs are located in the external layer of the thiol dendrimer accessible to the quencher. The precision of the method obtained as relative standard deviation was 3.76% (4 mg L(-1), n=3). This water soluble fluorescent nanocomposite showed a set of favorable properties to be used as a sensor for the C-reactive protein in serum samples, at concentrations of risk levels.

Más allá del diámetro aórtico. Biomecánica aórtica, análisis de elementos fi nitos y práctica clínica / No disponible

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CdSe and ZnSe quantum dots capped with PEA for screening C-reactive protein in human serum.

A fluorescence chemical sensor for C-reactive protein (CRP) was developed based on the selective interaction with CdSe and ZnSe quantum dots (QDs) coated with O-phosphorylethanolamine (PEA). Synthesis procedure and analytical parameters such as pH and ionic strength were studied. The decrease in the fluorescence emission intensity was explained due to the specific interaction of the QDs-PEA with CRP, and a correlation was observed between the quenching of the fluorescence and the concentration of CRP. The accuracy of the proposed method was 0.37% as RSD. The proposed method was applied to screen serum samples, and showed to be sensible at the C-reactive protein concentrations of risks levels.

Practical diagnosis of red cell disorders in southern Spain.

BACKGROUND: Hereditary red cell disorders are associated with a protective effect against malaria, which results in an increased prevalence in malaria-endemic areas. Migratory flows from these areas are resulting in a marked increase in such abnormalities in Southern Spain. METHODS: All hemoglobin disorders diagnosed between 1997 and 2010 have been recorded. Since 2008, we have performed systematic screening for hemoglobinopathies on African patients. A high-pressure liquid chromatography system was used as screening method for structural hemoglobinopathies and for separation of hemoglobin (Hb) F and A(2). RESULTS: We detected 666 cases in patients of foreign origin and 308 in native Spanish patients. Thalassemias (thal) are the most frequent disorders amongst the local population: ß-thal minor, 57.1% (176/308); α-thal, 18.2% (56/308), and δß-thal, 7.8% (24/308). In ethnic minorities, there is a huge variety of hemoglobinopathies: heterozygous Hb S, 45% (300/666); heterozygous Hb C, 15% (100/666); ß-thal minor, 13.7% (91/666); α-thal, 10.2% (68/666); Hb SS in 14 patients, and Hb CC in 9 patients. Of the native patients, 14 were found to have Hb AS and 9 Hb AC. CONCLUSION: Given the modern migratory flows, greater knowledge of these disorders is needed by all medical staff, and new practical and cost/time-effective diagnostic approaches have to be devised.

Analytical performance of a sensitive assay for cardiac troponin I with loci technology.

OBJECTIVES: To confirm the analytical performance of the Dimension Vista LOCI troponin I assay (cTnI). DESIGN AND METHOD: Limit of blank (LoB), limit of detection (LoD), limit of quantitation (LoQ) with a 10% coefficient of variation (CV), linearity, precision, method comparison, and 99th percentile upper reference limits (URL) were analyzed. Endogenous analytes and rheumatoid factor (RF) were tested for assay interference. RESULTS: The 99th percentile was 0.022 microg/L (CV=14%) and the LoQ was 0.036 microg/L. The ratio of 10% CV concentration to 99th percentile was 1.63. Linearity extended from 0 to 44.36 microg/L. The method comparison equation was Dimension(R) Vista=0.94 (Dimension RxL)+0.00 microg/L with bias at low levels. No interference was detected. CONCLUSIONS: This study shows acceptable performance characteristics of the LOCI cTnI assay on Dimension Vista to diagnosis and risk stratification of patients with acute coronary syndrome symptoms.

Effects of propofol on the leukocyte nitric oxide pathway: in vitro and ex vivo studies in surgical patients.

This study was designed to evaluate the mechanism by which propofol modifies leukocyte production of nitric oxide (NO) in humans. In vitro experiments used whole blood from healthy volunteers (n = 10 samples/experiment). Ex vivo experiments studied the effects of an intravenous dose of 2.5 mg propofol per kilogram body weight followed by intravenous infusion of 4 mg kg(-1) h(-1) in surgical patients in ASA class I or II (n = 20). In whole blood, neutrophils and plasma, we measured NO production and the activities of the enzymes nitric oxide synthase [inducible (iNOS) and constitutive (cNOS)] and cyclooxygenase [constitutive (COX-1) and inducible (COX-2)]. Concentrations of interleukins (IL-1beta, IL-6, and IL-10) and tumor necrosis factor-alpha (TNFalpha) were measured in plasma. In blood from healthy donors, propofol increased NO production and cNOS activity. The concentration of propofol that increased NO production by 50% (EC(50)) was 23.5 microM, and the EC(50) of propofol for cNOS was 18.6 microM. In blood from surgical patients, propofol increased NO production by 52% and cNOS activity by 57%. Propofol inhibited iNOS activity in vitro; the concentration that reduced activity by 50% (IC(50)) was 19.9 microM. In surgical patients propofol inhibited iNOS activity by 53%. COX-1 and COX-2 activities were inhibited in vitro (IC(50) 32.6 and 187 microM, respectively) and in surgical patients (53 and 81% inhibition, respectively). Plasma concentrations of IL-1beta, IL-6, and TNFalpha were significantly reduced in surgical patients (32, 23, and 21% inhibition, respectively). None of these parameters were modified in a group of patients (n = 10) anesthetized with sevoflurane. We conclude that propofol stimulated constitutive NO production and inhibited inducible NO production, possibly by curtailing the stimulation of iNOS by inflammatory mediators in surgical patients.

Dietary virgin olive oil reduces oxidative stress and cellular damage in rat brain slices subjected to hypoxia-reoxygenation.

We investigated how virgin olive oil (VOO) affected platelet and hypoxic brain damage in rats. Rats were given VOO orally for 30 days at 0.25 or 0.5 mL kg(-1) per day (doses A and B, respectively). Platelet aggregation, thromboxane B2, 6-keto-PGF(1alpha), and nitrites + nitrates were measured, and hypoxic damage was evaluated in a hypoxia-reoxygenation assay with fresh brain slices. Oxidative stress, prostaglandin E2, nitric oxide pathway activity and lactate dehydrogenase (LDH) activity were also measured. Dose A inhibited platelet aggregation by 36% and thromboxane B2 by 19%; inhibition by dose B was 47 and 23%, respectively. Virgin olive oil inhibited the reoxygenation-induced increase in lipid peroxidation (57% in control rats vs. 2.5% (P < 0.05) in treated rats), and reduced the decrease in glutathione concentration from 67 to 24% (dose A) and 41% (dose B). Brain prostaglandin E2 after reoxygenation was 306% higher in control animals, but the increases in treated rats were only 53% (dose A) and 45% (dose B). The increases in nitric oxide production (213% in controls) and activity of the inducible isoform of nitric oxide synthase (175% in controls) were both smaller in animals given VOO (dose A 84%; dose B 12%). Lactate dehydrogenase activity was reduced by 17% (dose A) and 42% (dose B). In conclusion, VOO modified processes related to thrombogenesis and brain ischemia. It reduced oxidative stress and modulated the inducible isoform of nitric oxide synthase, diminishing platelet aggregation and protecting the brain from the effects of hypoxia-reoxygenation.

Gender differences in the effect of aspirin on retinal ischemia, prostanoid synthesis and nitric oxide production in experimental type 1-like diabetes.

BACKGROUND: The protective effect of acetylsalicylic acid (aspirin) against cardiovascular events is known to be weaker in women than in men. The present study was designed to test whether this effect of aspirin differed between sexes in an experimental model of diabetes with retinal ischemia. METHODS: We compared nondiabetic rats and rats after 1, 2 and 3 months of diabetes that were given 2 mg/kg/day p.o. of aspirin from the first day of diabetes. The variables recorded were platelet aggregation, production of thromboxane B(2) (TxB(2)), 6-keto-prostaglandin F(1alpha) and aortic nitric oxide, and the percentage of the retinal surface occupied by horseradish peroxidase (HRP)-permeable vessels. RESULTS: In female rats made diabetic, TxB(2) synthesis was more markedly reduced, and the percentage of HRP-permeable retinal vessels was less markedly reduced, than in their male counterparts. The response to aspirin treatment was weaker in female than in male diabetic rats in terms of inhibition of TxB(2) synthesis, increased nitric oxide production, and prevention of the increase in the percentage of retinal surface covered by HRP-permeable vessels. CONCLUSION: Aspirin was less effective in preventing retinal ischemia in experimental diabetes in female than in male rats.

Hipercoagulabilidad debida a resistencia adquirida a la proteína C activada: ¿primer signo de neoplasia de colon? / Hypercoagulable state due to acquired protein C resistance. Harbinger of colonic neoplasm?

La resistencia a la proteína C activada (RPCa) hereditaria se ha identificado como un importante factor de riesgo para sucesos tromboembólicos, y consiste en una mutación del factor V que lo hace irreconocible para la inhibición por la proteína C activada (Factor V Leiden, FVL). Sin embargo, la RPCa también se describe en pacientes sin FVL (RPCa adquirida) asociada a la presencia de anticoagulante lúpico, embarazo y neoplasias. Describimos un caso de TVP en una mujer de 54 años, sin síntomas digestivos y con marcadores tumorales negativos, que presentaba RPCa y fue diagnosticada un año después de adenocarcinoma de colon. Una vez consiguió remisión completa, se normalizó la RPCa y se descartó que presentara FVL. En el estudio de trombofilia, el hallazgo de RPCa puede verse influida por reactantes de fase aguda o por un proceso neoplásico, por lo que requiere una valoración evolutiva y un rastreo genético del FVL

Hereditary activated protein C resistance (aPCR) has been indentified as an important risk factor for the occurrence of thromboembolic events. It is most frequently hereditary, and caused by a point mutation in factor V, named Factor V Leiden (FVL), which renders it resistant to the anticoagulant action of circulating protein C. However, aPCR can also be found in absence of FVL (acquired aPCR), associated to lupus anticoagulant, pregnancy or neoplasms. We report a case of deep venous thrombosis (DVT) in a 54 year-old woman, with no digestive symptoms and negative screening for biochemical tumor markers, who presented with DVT from FVL-negative aPCR, one year before being diagnosed of colonic adenocarcinoma. Once complete remission of the carcinoma was reached, aPCR returned to normal values. In thrombophilia screening studies, the finding of aPCR may be caused by acute-phase reactants or neoplastic processes, and therefore require evolutive evaluation and genetic search for FVL

Antioxidant and antiplatelet effects of the alpha-tocopherol-aspirin combination in type 1-like diabetic rats.

We analyze the effect of the combination of acetylsalicylic acid (2 mg/kg/day p.o.) and alpha-tocopherol (25 mg/kg/day p.o.) in a type-1-like experimental model of diabetes mellitus on platelet factors, endothelial antithrombotic factors and tissue oxidative stress. In diabetic rats, the combination of drugs had a greater inhibitory effect on platelet aggregation than in untreated control animals with diabetes (88.87%). The combination of drugs had little effect on the inhibition of thromboxane production (-90.81%) in comparison to acetylsalicylic acid alone (-84.66%), potentiated prostacyclin production (+162%) in comparison to alpha-tocopherol alone (+30.55%), and potentiated nitric oxide production (+241%) in comparison to either drug alone (acetylsalicylic acid +125%, alpha-tocopherol +142%). The combination of the two drugs improved the thromboxane/prostacyclin balance (0.145+/-0.009) in comparison to untreated diabetic animals (4.221+/-0.264) and in untreated healthy animals (0.651+/-0.045). It did not potentiate the antioxidant effect of either drug alone, but did increase tissue concentrations of reduced glutathione, especially in vascular tissue (+90.09% in comparison to untreated animals). In conclusion, in the experimental model of diabetes tested here, the combination of acetylsalicylic acid and alpha-tocopherol led to beneficial changes that can help protect tissues from thrombotic and ischemic phenomena.

Effects of hypoxia reoxygenation in brain slices from rats with type 1-like diabetes mellitus.

BACKGROUND: The aim of this study was to determine whether the brain tissue of type 1 diabetic animals is more susceptible to damage by hypoxia reoxygenation than healthy animals. METHODS: This study used rats with diabetes of 1, 2 and 3 months (N = 15 rats/group). Brain slices were subjected to hypoxia and reoxygenation for 180 min in vitro. We measured oxidative stress (lipid peroxidation, glutathione concentration and enzyme activities related to glutathione), concentration of prostaglandin E(2) (PGE(2)) and nitric oxide (NO) pathway (nitrite + nitrate, activities of constitutive (cNOS) and inducible (iNOS) nitric oxide synthase). As a parameter of cell death we measured the efflux of lactate dehydrogenase (LDH). RESULTS: After reoxygenation LDH activity increased in comparison to nondiabetic animals by 40, 40.6 and 68.9% in animals with diabetes of 1, 2 and 3 months duration, respectively. These changes were accompanied by greater increases in lipid peroxides (25.4, 93.7 and 92.8%). PGE(2) accumulated in significantly larger amounts in diabetic animals (62.5, 85.5 and 114%), and nitrite + nitrate accumulation was significantly greater in rats with diabetes of 2 (40.2%) and 3 months duration (24.0%). iNOS activity increased significantly in all the groups of diabetic animals, with the largest increases in rats with diabetes of 2 (18.6%) and 3 months duration (21.1%). CONCLUSIONS: The biochemical pathways involved in oxidative stress and neuronal death are more sensitive to hypoxia reoxygenation in type 1-like diabetic, as compared to normal, rats.

Effects of aspirin plus alpha-tocopherol on brain slices damage after hypoxia-reoxygenation in rats with type 1-like diabetes mellitus.

Diabetes mellitus is a risk factor for cerebrovascular ischemic disease. Aspirin (acetylsalicylic acid) is the most widely used drug for the secondary prevention of thrombotic phenomena. It has been also recently demonstrated that alpha-tocopherol influenced in vitro the antiplatelet effect of aspirin. The aim of the present study is to evaluate the effects aspirin plus alpha-tocopherol on cerebral oxidative stress, prostaglandin production and the nitric oxide pathway in a model of hypoxia-reoxygenation in rat brain slices. Our results show an imbalance in brain oxidative status (reflected mainly as the increase in lipid peroxides) as a result of diabetes itself rather than a failure of the glutathione-based antioxidant system. Moreover, our results also show a higher concentration of prostaglandins in the brain of diabetic animals and a higher nitric oxide concentration, mainly through a high iNOS activity. After 180 min of post-hypoxia reoxygenation, LDH activity was 40.6% higher in animals with diabetes, in comparison to non-diabetic animals. The increase of the LDH efflux observed in non-treated rats was reduced by 31.2% with aspirin, by 34.7% with alpha-tocopherol and by 69.8% with the association aspirin-alpha-tocopherol. The accumulation of prostaglandin E2 observed in diabetic non-treated rats was reduced statistically after the treatment with aspirin (34.2% inhibition), alpha-tocopherol (19.3% inhibition) or the association aspirin-alpha-tocopherol (54.4% inhibition). Nitric oxide production after 180 min reoxygenation was significantly reduced in aspirin (36.4%), alpha-tocopherol (22.7%) and aspirin-alpha-tocopherol (77.8%) treated rats with respect to diabetic non-treated animals; this was related mainly with a reduction in iNOS activity. The association between aspirin and alpha tocopherol could protects against brain ischemic-reperfusion damage with a better profile than aspirin alone.

[Hypercoagulable state due to acquired protein C resistance, harbinger of colonic neoplasm?]. / Hipercoagulabilidad debida a resistencia adquirida a la proteína C activada: primer signo de neoplasia de colon?

Hereditary activated protein C resistance (aPCR) has been identified as an important risk factor for the occurrence of thromboembolic events. It is most frequently hereditary, and caused by a point mutation in factor V, named Factor V Leiden (FVL), which renders it resistant to the anticoagulant action of circulating protein C. However, aPCR can also be found in absence of FVL (acquired aPCR), associated to lupus anticoagulant, pregnancy or neoplasms. We report a case of deep venous thrombosis (DVT) in a 54 year-old woman, with no digestive symptoms and negative screening for biochemical tumor markers, who presented with DVT from FVL-negative aPCR, one year before being diagnosed of colonic adenocarcinoma. Once complete remission of the carcinoma was reached, aPCR returned to normal values. In thrombophilia screening studies, the finding of aPCR may be caused by acute-phase reactants or neoplastic processes, and therefore require evolutive evaluation and genetic search for FVL.