Use of a carbon paste electrode modified with spinel-type manganese oxide as a potentiometric sensor for lithium ions in flow injection analysis

A potentiometric sensor constructed from a mixture of 25% (m/m) spinel-type manganese oxide (lambda-MnO2), 50% (m/m) graphite powder and 25% (m/m) mineral oil is used for the determination of lithium ions in a flow injection analysis system. Experimental parameters, such as pH of the carrier solution, flow rate, injection sample volume, and selectivity for Li+ against other alkali and alkaline-earth ions and the response time of this sensor were investigated. The sensor response to lithium ions was linear in the concentration range 8.6 x 10(-5) - 1.0 x 10(-2) mol L-1 with a slope 78.9 +/- 0.3 mV dec(-1) over a wide pH range 7 - 10 (Tris buffer), without interference of other alkali and alkaline-earth metals. For a flow rate of 5.0 mL min(-1) and a injection sample volume of 408.6 muL, the relative standard deviation for repeated injections of a 5.0 x 10(-4) mol L-1 lithium ions was 0.3%.

Use of comet assay to assess DNA damage in patients infected by Helicobacter pylori - Comparisons between visual and image analyses

Studies of DNA damage in gastric epithelial cells of Helicobacter pylori (H. pylori)-infected patients are conflicting, possibly due to different methods used for scoring DNA damage by Comet assay. Therefore, we compared the sensitivity of visual microscopic analysis (arbitrary units-scores and comets%) and image analysis system (tail moment), in the gastric epithelial cells from the antrum and corpus of 122 H. pylori-infected and 32 non-infected patients. The feasibility of cryopreserved peripheral blood lymphocytes and whole-blood cells for DNA damage biomonitoring was also investigated. In the antrum, the levels of DNA damage were significantly higher in H. pylori-infected patients with gastritis than in non-infected patients with normal mucosa, when evaluated by image analysis system, arbitrary units and comets%. In the corpus, the comets% was not sufficiently sensitive to detect the difference between H. pylori-infected patients with gastritis and non-infected patients with normal mucosa. The image analysis system was sensitive enough to detect differences between non-infected patients and H. pylori-infected patients with mild gastritis and between infected patients with moderate and severe gastritis, in both antrum, and corpus, while arbitrary units and comets% were unable to detect these differences. In cryopreserved peripheral blood lymphocytes, the levels of DNA damage (tail moment) were significantly higher in H. pylori-infected patients with moderate and severe gastritis than in non-infected patients. Overall, our results indicate that the image analysis system is more sensitive and adequate to measure the levels of DNA damage in gastric epithelial cells than the other methods assayed. (c) 2005 Elsevier B.V. All rights reserved.

Sequence, evolution and ligand binding properties of mammalian Duffy antigen/receptor for chemokines

The Duffy antigen/receptor for chemokine, DARC, acts as a widely expressed promiscuous chemokine receptor and as the erythrocyte receptor for Plasmodium vivax. To gain insight into the evolution and structure/function relations of DARC, we analyzed the binding of anti-human Fy monoclonal antibodies (mAbs) and human chemokines to red blood cells (RBCs) from 11 nonhuman primates and two nonprimate mammals, and we elucidated the structures of the DARC genes from gorilla, gibbon, baboon, marmoset, tamarin, night monkey and cattle. CXCL-8 and CCL-5 chemokine binding analysis indicated that the promiscuous binding profile characteristic of DARC is conserved across species. Among three mAbs that detected the Fy6 epitope by flow cytometric analysis of human and chimpanzee RBCs, only one reacted with night monkey and squirrel monkey. Only chimpanzee RBCs bound a significant amount of the anti-Fy3 mAb. Fy3 was also poorly detected on RBCs from gorilla, baboon and rhesus monkey, but not from new world monkeys. Alignment of DARC homologous sequences allowed us to construct a phylogenetic tree in which all branchings were in accordance with current knowledge of primate phylogeny. Although DARC was expected to be under strong internal and external selection pressure, in order to maintain chemokine binding and avoid Plasmodium vivax binding, respectively, our present study did not provide arguments in favor of a selection pressure on the extracellular domains involved in ligand specificity. The amino acid variability of DARC-like polypeptides was found to be well correlated with the hydrophylicity indexes, with the highest divergence on the amino-terminal extracellular domain. Analysis of the deduced amino acid sequences highlighted the conservation of some amino acid residues, which should prove to be critical for the structural and functional properties of DARC.

Standardization of platelet parameters determination in blood samples collected with EDTA

The Abbott Cell-Dyn 3000 automated hematological analyzer prepares a histogram of platelet volume, which is measured by a technique using electrical impedance, inferring from its platelet count (PLT), mean platelet volume (MPV) and platelet distribution width (PDW). This equipment also calculates the plateletcrit (PCT). These platelet parameters may be important to evaluate platelet function, but they require standardization, because platelets swell when in contact with ethylenediaminetetra-acetic acid salts, hence an increase in blood sample storage time produces artificially increased results. To assess the effect of storage time on MPV, PLT, PDW and PCT, blood samples from 23 sickle cell anemia patients during steady state (Group I) and 50 from healthy controls (Group II) were placed in Vacutainer® tubes with dipotassium ethylenediaminetetra-acetic acid and measured over a period of 1440 minutes (24 h) at the following times: immediately after the venipuncture (time 0), 15, 30, 60, 120, 240, 360, 480 and 1440 minutes. The mean values of MPV and PCT were significantly increased (p<0.00001) along the storage time in both groups. The mean values of PLT and PDW were practically stable (p>0.05) throughout the storage time in both groups.

A comparison of human and porcine acellular dermal tissues in the subcutaneous space of a rat model

The study compared the host response to a human and a porcine acellular dermal tissue implanted in the subcutaneous space of a rat model. The human and porcine acellular grafts were surgically implanted in the subcutaneous tissue of rats (5 rats/group) and the materials were evaluated at 7, 15, 30, 60 and 180 postoperative days (PO). The histological immune response was quantified using a digital image analysis system, which evaluated the number of vessels present in the implants and in the surrounding soft tissue, the area of inflammatory cell infiltration in the grafts, the width of the capsular formation present around the tissues and the area of implants absorbed. The data were submitted to statistical analysis. Light microscopy showed mononuclear cellular infiltration, the presence of a capsular formation surrounding the grafts and the presence of vacuolar structures (optically empty spaces) inside the implants. The image analysis comparing both materials showed significant inflammatory cells in the human graft at 15 and 30 PO, thicker capsular formation in the porcine tissue at 60 PO, increased number of vessels inside the implants and in the surrounding tissues in the porcine graft and a similar absorption pattern in both materials at 180 PO. The histological findings showed that both tissues were well-tolerated when implanted in the subcutaneous tissue of rats, allowing us to consider the porcine acellular dermal graft as a provisional alternative material for reconstructive plastic surgery. Copyright © 2005 Taylor & Francis LLC.

Uterine and luteal hemodynamic evaluation of the non pregnant mare

Background: Studies with Doppler ultrassonography started at the end of the 90s for the determination of physiological and pathological alterations in the reproductive tract of the mare. Uterine alterations caused by inflammation, response from seminal plasma infusion, hormonal variations during estrous and diestrus, pregnancy and action of various vasoactive factors influence on the vascular perfusion detected by Doppler ultrasound. The development of efficient methods for uterine quality evaluation is of big importance for field equine reproduction veterinarians, once uterine environment is responsible for pregnancy maintenance. Review: Nowadays, the most used methods of uterine evaluation are the mode B ultrassonography, cytology, culture and biopsy. Hemodynamic evaluation of the uterus can be done by spectral data collected from large vessels, as A. uterine and its ramifications, or from subjective or objective evaluations from endometrium, miometrium and mesometrium attachment, which provide data referent to local and specific alterations of the evaluated area. Alterations in uterine vascular perfusion has been detected during estrous cycle, during pregnancy and in cases of infusion of inflammatory substances. These alterations happen because of vasoactive substances that act in the uterus during these events, however, most of these vasoactive substances are probably not even known. Also, important hemodynamic alterations in old mares, as an increase in vascular resistance, have been described. This increase might result from fibrosis of the uterus and in women it is considered to be a cause of infertility. In mares, periglandular fibrosis of the endometrium is considered to be the major diagnosable cause of embryonic and fetal loss in older mares. For the CL, ovarian artery of the mare supplies the ovary as well as the oviduct and therefore can be used for evaluation of these areas. The CL evaluation can also be done by the percentage of luteum area with colored signals as an indicator of the extent of blood flow. The percentage of the CL area with colored signals is determined subjectively by images observations in real time and/or by a freezing Power Doppler cross-section image with the maximum number of color pixels taped and the total number of color pixels is assessed by a computer analysis system. Therefore, a high correlation between plasmatic progesterone and CL vascularization also allows the CL evalution by this technique. In a first report, CL circulation reached its maximum on D5, the progesterone concentration in peripheral blood increased until D7 and in a posterior report, maximum perfusion was achieved two days after the maximum progesterone concentration (D8). Blood flow reduced between D10-D14 some days before the plasma progesterone decrease and, during the luteolytic period (D15-D17), the decline in CL blood-flow area was greater than blood flow decrease. Conclusion: Doppler ultrassonography add knowledge about uterine viability and CL functionality can be easily used by veterinarians in the field. It is a noninvasive method that provides real time results. However, because of the short time studies in this area have been done, many other answers still need to be found until normal and pathological patterns will be established.

Morphology of the midgut of Rhipicephalus sanguineus (Latreille, 1806) (Acari: Ixodidae) adult ticks in different feeding stages

The intestinal epithelial cells of ticks are fundamental for their full feeding and reproductive success, besides being considered important sites for the development of pathogens. Rhipicephalus sanguineus ticks are known for their great medical and veterinary importance, and for this reason, the knowledge of their intestinal morphology may provide relevant subsidies for the control of these animals, either by direct acaricidal action over these cells or by the production of vaccines. Therefore, this study aimed to describe the midgut morphology of male and female R. sanguineus ticks in different feeding stages, by means of histological analysis. Significant differences were observed between the genders, and such alterations may refer mainly to the distinct demands for nutrients, much higher in females, which need to develop and carry out the egg-laying process. In general, the midgut is coated by a thin muscle layer and presents a pseudostratified epithelium, in which two basic types of cells can be observed, connected to a basal membrane - generative or stem and digestive cells. The latter was classified as follows: residual, deriving from the phase anterior to ecdysis; pinocytic, with vesicles containing liquid or pre-digested components of blood; phagocytic, with entire cells or remnants of nuclear material inside cytoplasmic vesicles; and mature, free in the lumen. Digestion is presumably intracellular and asynchronous and corresponds to a process which starts with the differentiation of generative cells into pinocytic digestive cells, which subsequently start to phagocytize intact blood cells and finally detach from the epithelium, being eliminated with feces. © 2012 Springer-Verlag Berlin Heidelberg.

Chronic Ethanol Consumption Alters All-Trans-Retinoic Acid Concentration and Expression of Their Receptors on the Prostate: A Possible Link Between Alcoholism and Prostate Damage

Background: Ethanol (EtOH) alters the all-trans-retinoic acid (ATRA) levels in some tissues. Retinol and ATRA are essential for cell proliferation, differentiation, and maintenance of prostate homeostasis. It has been suggested that disturbances in retinol/ATRA concentration as well as in the expression of retinoic acid receptors (RARs) contribute to benign prostate hyperplasia and prostate cancer. This study aimed to evaluate whether EtOH consumption is able to alter retinol and ATRA levels in the plasma and prostate tissue as well as the expression of RARs, cell proliferation, and apoptosis index. Methods: All animals were divided into 4 groups (n = 10/group). UChA: rats fed 10% (v/v) EtOH ad libitum; UChACo: EtOH-naïve rats without access to EtOH; UChB: rats fed 10% (v/v) EtOH ad libitum; UChBCo: EtOH-naïve rats without access to EtOH. Animals were euthanized by decapitation after 60 days of EtOH consumption for high-performance liquid chromatography and light microscopy analysis. Results: EtOH reduced plasma retinol concentration in both UChA and UChB groups, while the retinol concentration was not significantly different in prostate tissue. Conversely, plasma and prostate ATRA levels increased in UChB group compared with controls, beyond the up-regulation of RARβ and -γ in dorsal prostate lobe. Additionally, no alteration was found in cell proliferation and apoptosis index involving dorsal and lateral prostate lobe. Conclusions: We conclude that EtOH alters the plasma retinol concentrations proportionally to the amount of EtOH consumed. Moreover, high EtOH consumption increases the concentration of ATRA in plasma/prostate tissue and especially induces the RARβ and RARγ in the dorsal prostate lobe. EtOH consumption and increased ATRA levels were not associated with cell proliferation and apoptosis in the prostate. © 2012 by the Research Society on Alcoholism.

An optimised electrochemical biosensor for the label-free detection of C-reactive protein in blood

C-reactive protein (CRP) is an acute phase protein whose levels are increased in many disorders. There exists, in particular, a great deal of interest in the correlation between blood serum levels and the severity of risk for cardiovascular disease. A sensitive, label-free, non-amplified and reusable electrochemical impedimetric biosensor for the detection of CRP in blood serum was developed herein based on controlled and coverage optimised antibody immobilization on standard polycrystalline gold electrodes. Charge transfer resistance changes were highly target specific, linear with log. CRP. concentration across a 0.5-50. nM range and associated with a limit of detection of 176. pM. Significantly, the detection limits are better than those of current CRP clinical methods and the assays are potentially cheap, relatively automated, reusable, multiplexed and highly portable. The generated interfaces were capable not only of comfortably quantifying CRP across a clinically relevant range of concentrations but also of doing this in whole blood serum with interfaces that were, subsequently, reusable. The importance of optimising receptor layer resistance in maximising assay sensitivity is also detailed. © 2012.

Epidemiologia das reações transfusionais imediatas no Hospital Amaral Carvalho de Jaú

Pós-graduação em Pesquisa e Desenvolvimento (Biotecnologia Médica) - FMB

Evidências clínico-patológicas de ovinos intoxicados experimentalmente com sementes de Crotalaria spectabilis (Leg.papilionoidea)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Caracterização genética de avestruzes (Struthio camelus) usando marcadores RAPD

O objetivo deste trabalho foi avaliar a variabilidade genética de populações de avestruzes (Struthio camelus) por meio de marcadores RAPD (Polimorfismos de DNA amplificado ao acaso). Foram coletadas 121 amostras de indivíduos procedentes dos estados do Pará, Maranhão, Tocantins e Minas Gerais. O DNA genômico foi extraído a partir de sangue total. A triagem de iniciadores permitiu a seleção de 15 entre os 60 analisados que foram amplificados pelo método PCR. Os produtos da PCR foram visualizados em gel de agarose 1,5% e foi gerada uma matriz binária para os fragmentos amplificados com presença (1) e ausência (0) de banda. Para a verificação do número ótimo de bandas polimórficas foi realizada a análise de bootstrap por meio do software GQMOL. Para a análise dos dados foi utilizado o programa NTSYS-pc (Numerical Taxonomy and Multivariate Analysis Sistem), versão 2.02. A similaridade entre as amostras foi analisada através do coeficiente de Jaccard. Foi gerada uma matriz de distância cofenética, usando o módulo Sahncof, do programa NTSYS 2.2. Para realização da estruturação gênica o procedimento empregado foi a análise de variância molecular (AMOVA), processada no software Arlequin 2.0 (Schneider et al., 2000). Os 15 iniciadores geraram um total de 109 bandas polimórficas. A análise de bootstrap mostrou que a partir de 100 bandas o trabalho já se torna mais confiável, uma vez que a magnitude da correlação foi bem próxima do valor máximo (r=0,99), como também a soma de quadrados dos desvios (SQd) atingiu valor baixo 1,25 e o valor do estresse (E) foi de 0,05. Na análise entre pares de grupos, foi verificado que a maior e menor similaridade estão em torno, respectivamente, de 0,86 e 0,00. No que diz respeito à distribuição de freqüência das similaridades obtidas entre os 5.644 pares formados na matriz genética, pode-se verificar que 32,69 % dos pares ficaram incluídos nas classes com similaridades variando de 0,01 a 0,10. Nota-se que a maior porcentagem (85,59%) dos pares ficou distribuídos nas três primeiras classes das extremidades e que a minoria deles (14,41%) apresentou similaridades variando de 0,21 a 1,00. O teste de Mantel mostrou correlação de 0,81 e o dendrograma gerou 67 grupos delimitados pela Sm que foi de 0,49. A maior similaridade foi de 0,86 e a menor de 0,06. Os dados relativos à análise de variância molecular mostraram que a porcentagem de variação genética entre procedências foi baixa e significativa (24,03%, p < 0,0001), evidenciando que grande parte da variação encontra-se dentro das populações (75,97 %). Os marcadores RAPD foram eficientes na caracterização da similaridade genética.

Desenvolvimento de um sistema de análise de imagem para quantificação do tamanho e distribuição de partículas de desgaste

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Determination of carbofuran and diuron in FIA system using electrochemical sensor modified with organometallic complexes and graphene oxide

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Determination of salicylate in blood serum using an amperometric biosensor based on salicylate hydroxylase immobilized in a polypyrrole-glutaraldehyde matrix

The use of an amperometric biosensor for the salicylate determination in blood serum is described. The biosensor is based on salicylate hydroxylase (EC 1.14.13.1) electropolymerized onto a glassy carbon-working electrode with polypyrrole and glutaraldehyde, to improve the biosensor lifetime. The hexacyanoferrate (II) was also incorporated to work as a redox mediator to minimize possible interferences. The salicylate is enzymatically converted to catechol, which is monitored amperometrically by its electrooxidation at +0.170 V versus SCE (saturated calomel electrode). Salicylate determination was carried out maintaining the ratio between β-NADH and salicylate at 4:1 (30°C). The amperometric response of the biosensor was linearly proportional to the salicylate concentration between 2.3 x 10-6 and 1.4 x 10-5 mol l- 1, in 0.1 mol l-1 phosphate buffer (pH 7.8), containing 0.1 mol l-1 KCl and 5.0 x 10-4 mol l-1 Na2H2EDTA, as supporting electrolyte. The recovery studies, in the presence of several interfering compounds, showed recoveries between 96.4 and 104.8%. The useful lifetime of the biosensor in the concentration range evaluated was at least 40 days, in continuous use. Blood serum samples analyzed by this biosensor showed a good correlation compared to the spectrophotometric method (Trinder) used as reference, presenting relative deviations lower than 7.0%. (C) 2000 Elsevier Science B.V.