Immunosensor for the diagnosis of Chagas' disease

Trypanosoma cruzi proteins from epimastigote membranes, herein referred as antigens, have been used for the construction of an amperometric immunosensor for serological diagnosis of Chagas' disease. The proteins used had a molecular mass ranging from 30 to 100 kDa. The gold electrode was treated with cysteamine and glutaraldehyde prior to antigen immobilization. Antibodies present in the serum of patients with Chagas' disease were captured by the immobilized antigens and the affinity interaction was monitored by chronoamperometry at a potential of -400 mV (versus Ag pseudo-reference electrode) using peroxidase-labeled IgG conjugate and hydrogen peroxide, iodide substrate. The incubation time to allow maximum antigen-antibody and antibody-peroxidase-labeled IgG interactions was 20 min with a reactivity threshold at -0.104 mu A. (c) 2004 Elsevier B.V. All rights reserved.

Gestão de estoques: uma proposta de reposição contínua para material médico hospitalar e medicamentos em um hospital universitário federal do estado do Rio Grande do Norte

The inventory management in hospitals is of paramount importance, since the supply materials and drugs interruption can cause irreparable damage to human lives while excess inventories involves immobilization of capital. Hospitals should use techniques of inventory management to perform replenishment in shorter and shorter intervals, in order to reduce inventories and fixed assets and meet citizens requirements properly. The inventory management can be an even bigger problem for public hospitals, which have restrictions on the use of resources and decisionmaking structure more bureaucratized. Currently the University Hospital Onofre Lopes (HUOL) uses a periodic replacement policy for hospital medical supplies and medicines, which involves one moment surplus stock replenishment, the next out of stock items. This study aims to propose a system for continuous replenishment through order point for inventory of medical supplies and medicines to the hospital HUOL. Therefore, a literature review of Federal University Hospitals Management, Logistics, Inventory Management and Replenishment System in Hospitals was performed, emphasizing the demand forecast, classification or ABC curve and order point system. And also, policies of inventory management and the current proposal were described, dealing with profile of the mentioned institution, the current policy of inventory management and simulation for continuous replenishment order point. For the simulation, the sample consisted of 102 and 44 items of medical and hospital drugs, respectively, selected using the ABC classification of inventory, prioritizing items of Class A, which contains the most relevant items in added value, representing 80 % of the financial value in 2012 fiscal year. Considering that it is a public organization, subject to the laws, we performed two simulations: the first, following the signs for inventory management of Instruction No. 205 (IN 205 ), from Secretary of Public Administration of the Presidency ( SEDAP / PR ), and the second, based on the literature specializing in inventory management hospital. The results of two simulations were compared to the current policy of replenishment system. Among these results are: an indication that the system for continuous replenishment reorder point based on IN 205 provides lower levels of safety stock and maximum stock, enables a 17% reduction in the amount spent for the full replenishment of inventories, in other words, decreasing capital assets, as well as reduction in stock quantity, also the simulation made from the literature has indicated parameters that prevent the application of this technique to all items of the sample. Hence, a change in inventory management of HUOL, with the application of the continuous replenishment according to IN 205, provides a significant reduction in acquisition costs of medical and hospital medicine

Indicator-free electrochemical DNA hybridization biosensor

A new electrochemical hybridization biosensor protocol without an external indicator is described. The biosensor format involves the immobilization of inosine-substituted (guanine-free) probe onto the carbon paste transducer, and a direct chronopotentiometric detection of the duplex formation by the appearance of the guanine oxidation peak of the target. Such a use of the intrinsic DNA electrochemical response for monitoring hybridization events offers several advantages (over the common use of external indicators), including the appearance of a new peak, a Aat background, or simplicity. A 4 min short hybridization period allows a detection limit around 120 ng/ml. Performance characteristics of the sensor are described along with future prospects. (C) 1998 Elsevier B.V. B.V. All rights reserved.

Preparation, characterization, and CuX2 and CoX2 (X = Cl-, Br-, ClO4-) adsorption behavior of a polyhedral oligomer silsesquioxane functionalized with an organic base

In this paper we report on the synthesis, characterization, and adsorption properties of the first 3-amino-1,2,4-triazole-modified porous silsesquioxane (ATPS). The isotherms of adsorption of MX2 (M = Cu(II), Co(II); X = Cl-, Br-, ClO4-) by ATPS were studied in ethanol and aqueous solutions at 298 K. The results showed that there is a good fit between the experimental data and the Langmuir isotherm. The adsorption capacity in both solvents followed the sequence Cu(II) >> Co(II). The lowest adsorption for Co(II) should be related to the largest hydration volume, which obstructs the adsorption capacity of the surface, and consequently causes a decrease in the number of cations adsorbed. For the salts with different anions the sequence was MCl2 > MBr2 > M(ClO4)2 in both solvents. The low affinity for M(ClO4)(2) toward the solid phase is a consequence of the poorer coordination ability of the ClO4-. Adsorptions from ethanol solutions were higher than those from aqueous solutions due to the higher polarity of water, which can more strongly solvate the solute and the basic sites on the surface. The following adsorption capacities (in mmol g(-1)) were determined: 0.24 (aq) and 0.84 (eth) for CuCl2, 0.09 (aq) and 0.16 (eth) for CuBr2, and 0.08 (aq) and 0.11 (eth) for Cu(ClO4)(2); 0.02 (aq) and 0.07 (eth) for CoCl2, 0.02 (aq) and 0.06 (eth) for CoBr2, and 0.01 (aq) and 0.05 (eth) for Co(ClO4)(2). (c) 2007 Elsevier B.V. All rights reserved.

Nanoparticles of octakis [3-(3-amino-1,2,4-triazole)propyl] octasilsesquioxane as ligands for Cu(II), Ni(II), Cd(II), Zn(II), and Fe(III) in aqueous solution

Nanoparticles of octakis[3-(3-amino-1,2,4-triazole)propyl]octasilsesquioxane (ATZ-SSQ) were tested as ligands, for transition-metal ions in aqueous solution with a special attention to sorption isotherms, ligand-metal interaction, and determination of metal ions in natural waters. The adsorption potential of the material ATZ-SSQ was compared with related [3(3-amino-1,2,4-triazole)propyl]silica gel (ATZ-SG). The adsorption was performed using a batchwise process and both organofunctionalized surfaces showed the ability to adsorb the metal ions from aqueous solution. The Langmuir model was used to simulate the sorption isotherms. The results suggest that the sorption of these metals on ATZ-SSQ and ATZ-SG occurs mainly by surface complexation. The equilibrium condition is reached at time lower than 3 min for ATZ-SSQ, while for ATZ-SG is only reached at time of 25 min. The maximum metal ion uptake values for ATZ-SSQ were higher than the corresponding values achieved with the ATZ-SG. In order to obtain more information on the ligand-metal interaction of the complexes on the surface of the ATZ-SSQ nanomaterial, ESR study with various degrees of copper loadings was carried out. The ATZ-SSQ was tested for the determination (in flow using a column technique) of the metal ions present in natural waters. (C) 2007 Elsevier B.V. All rights reserved.

Study of copper complexes absorbed on a silica gel surface chemically modified with 5-amino-1,3,4-thiadiazole-2-thiol

The isotherms of adsorption of CuX2 (XCl-, Br-, ClO4-) by silica gel chemically modified with 5-amino-1,3,4-thiadiazole-2-thiol were studied in acetone and ethanol solutions, at 25 degrees C. The following equilibria constants (in L mol(-1)) were determined: (a) CuCl2, 3.2 x 10(3) (ac), 2.5 x 10(3) (eth); (b) CuBr2, 2.9 x 10(3) (ac), 2.3 x 10(3) (eth); (c) Cu(ClO4)(2), 1.8 x 10(3) (ac), 1.2 x 10(3) (eth); ac, acetone; eth, ethanol. The electron spin resonance spectra of the surface complexes indicated a tetragonal-distorted structure in the case of lower degrees of metal loading on the chemically modified surface. The d-d electronic transition spectra showed that for the ClO4- complex, the peak of absorption did not change for any degree of metal loading and for Cl- and Br- complexes, the peak maxima shifted to higher energy with lower metal loadings. (C) 1998 Academic Press.

Adsorption of CuX2 (X = Cl-, Br-, and ClO4-) on a silica gel surface chemically modified with thiazolidine-2-thione from acetone and ethanol solutions

The isotherms of adsorption of CuX2 (X = Cl-, Br, ClO4-,) by silica gel chemically modified with thiazolidine-2-thione were studied in acetone (ac) and ethanol (eth) solutions at 25 degrees C. The following equilibrium constants (in 1 mol(-1)) were determined: a) CuCl2, 1.9 x 10(3) (ac), 1.6 x 10(3) (eth); b) CuBr2, 1.7 x 10(3) (ac), 1.2 x 10(3) (eth); c) Cu(ClO4)(2), 1.1 x 10(3) (ac), 1.0 x 10(3) (eth). The electron spin resonance spectra of the surface complexes indicate a tetragonal distorted structure in the case of lower degrees of metal loading on the chemically modified surface. The d-d electronic transition spectra show that for the ClO4- complex, the peak of absorption did not change for any degree of metal loading, and for Cl- and Br complexes, the peak maxima shift to higher energy with lower metal loading.

Estudo da imobilização de proteases para a síntese de oligolisinas

Enzymatic synthesis of peptides using proteases has attracted a great deal of attention in recent years. One key challenge in peptide synthesis is to find supports for protease immobilization capable of working in aqueous medium at high performance, producing watersoluble oligopeptides. At present, few reports have been described using this strategy. Therefore, the aim of this thesis was to immobilize proteases applying different methods (Immobilization by covalent bound, entrapment onto polymeric gels of PVA and immobilization on glycidil metacrylate magnetic nanoparticles) in order to produce water-soluble oligopeptides derived from lysine. Three different proteases were used: trypsin, α-chymotrypsin and bromelain. According to immobilization strategies associated to the type of protease employed, trypsin-resin systems showed the best performance in terms of hydrolytic activity and oligopeptides synthesis. Hydrolytic activities of the free and immobilized enzymes were determined spectrophotometrically based on the absorbance change at 660 nm at 25 °C (Casein method). Calculations of oligolysine yield and average degree of polymerization (DPavg) were monitored by 1H-NMR analysis. Trypsin was covalently immobilized onto four different resins (Amberzyme, Eupergit C, Eupergit CM and Grace 192). Maximum yield of bound protein was 92 mg/g, 82 mg/g and 60 mg/g support for each resin respectively. The effectiveness of these systems (Trypsin-resins) was evaluated by hydrolysis of casein and synthesis of water-soluble oligolysine. Most systems were capable of catalyzing oligopeptide synthesis in aqueous medium, albeit at different efficiencies, namely: 40, 37 and 35% for Amberzyme, Eupergit C and Eupergit CM, respectively, in comparison with free enzyme. These systems produced oligomers in only 1 hour with DPavg higher than free enzyme. Among these systems, the Eupergit C-Trypsin system showed greater efficiency than others in terms of hydrolytic activity and thermal stability. However, this did not occur for oligolysine synthesis. Trypsin-Amberzyme proved to be more successful in oligopeptide synthesis, and exhibited excellent reusability, since it retained 90% of its initial hydrolytic and synthetic activity after 7 reuses. Trypsin hydrophobic interactions with Amberzyme support are responsible for protecting against strong enzyme conformational changes in the medium. In addition, the high concentration of oxirane groups on the surface promoted multi-covalent linking and, consequently, prevented the immobilized enzyme from leaching. The aforementioned results suggest that immobilized Trypsin on the supports evaluated can be efficiently used for oligopeptides synthesis in aqueous media

Early hemodynamic and renal effects of hemorrhagic shock resuscitation with lactated Ringer's solution, hydroxyethyl starch, and hypertonic saline with or without 6% dextran-70

Background. Considering the renal effects of fluid resuscitation in hemorrhaged patients, the choice of fluid has been a source of controversy. In a model of hemorrhagic shock, we studied the early hemodynamic and renal effects of fluid resuscitation with lactated Ringer's (LR), 6% hydroxyethyl starch (HES), and 7.5% hypertonic saline (HS) with or without 6% dextran-70 (HSD).Materials and methods. Forty-eight dogs were anesthetized and submitted to splenectomy. An estimated 40% blood volume was removed to maintain mean arterial pressure (MAP) at 40 mm Hg for 30 min. The dogs were divided into four groups: LR, in a 3:1 ratio to removed blood volume; HS, 6 mL kg(-1); HSD, 6 mL kg(-1); and HES in a 1:1 ratio to removed blood volume. Hemodynamics and renal function were studied during shock and 5, 60, and 120 min after fluid replacement.Results. Shock treatment increased MAP similarly in all groups. At 5 min, cardiac filling pressures and cardiac performance indexes were higher for LR and HES but, after 120 min, there were no differences among groups. Renal blood flow and glomerular filtration rate (GFR) were higher in LR at 60 min but GFR returned to baseline values in all groups at 120 min. Diuresis was higher for LR at 5 min and for LR and HES at 60 min. There were no differences among groups in renal variables 120 min after treatment.Conclusions. Despite the immediate differences in hemodynamic responses, the low-volume resuscitation fluids, HS and HSD, are equally effective to LR and HES in restoring renal performance 120 min after hemorrhagic shock treatment. (c) 2006 Elsevier B.V. All rights reserved.

Venous ulcer: epidemiology, physiopathology, diagnosis and treatment

This review discusses the epidemiology, pathogenesis, diagnosis and current therapeutic options for venous ulcer. Venous ulcer is a severe clinical manifestation of chronic venous insufficiency (CVI). It is responsible for about 70% of chronic ulcers of the lower limbs. The high prevalence of venous ulcer has a significant socioeconomic impact in terms of medical care, days off work and reduced quality of life. Long-term therapeutics are needed to heal venous ulcers and recurrence is quite common, ranging from 54 to 78%. Thrombophlebitis and trauma with long-term immobilization predisposing to deep venous thrombosis are important risk factors for CVI and venous ulcer. The most recent theories about pathogenesis of venous ulcer have associated it with microcirculatory abnormalities and generation of an inflammatory response. Management of venous leg ulcers is based on understanding the pathogenesis. In recent years novel therapeutic approaches for venous ulcers have offered valuable tools for the management of patients with this disorder.

Luxação aguda isolada da articulação tibiofibular proximal

A luxação traumática isolada da articulação tibiofibular proximal é rara. Esta lesão pode não ser reconhecida ou diagnosticada no atendimento inicial. A ausência de suspeita clínica pode causar problemas para o diagnóstico. O diagnóstico necessita de história precisa do mecanismo e sintomas da lesão, avaliação clínica e radiográfica adequada de ambos joelhos. Casos não reconhecidos são fonte de alterações crônicas. O tratamento é feito por redução fechada e imobilização ou, em casos irredutíveis ou instáveis, redução aberta com fixação interna temporária. Um caso raro de luxação tibiofibular proximal isolada em um jogador de basquetebol é relatado para ilustrar essa lesão.

Efeito da heparina sódica e da enoxaparina na consolidação de fratura da tíbia no rato: avaliação clínica e anatomopatológica e biomecânica

Foi realizado estudo experimental em ratos para avaliar o efeito do anticoagulante na consolidação óssea, conforme critérios clínicos, anatomopatológicos e biomecânicos. Manualmente, após perfuração do osso, foi produzida fratura aberta, na diáfise da tíbia direita, mantida sem imobilização, em 72 ratos machos da linhagem Wistar, com 60 dias de idade e peso médio de 242 gramas. Doze horas após a fratura, foi iniciado tratamento anticoagulante, mantido por 28 dias. Via subcutânea, um grupo recebeu heparina sódica na dose de 200UI/Kg de 12 em 12 horas, enquanto outro, recebeu enoxaparina na dose de 1mg/Kg de 12 em 12 horas, doses preconizadas para tratamento do tromboembolismo em humanos. O terceiro grupo, controle, recebeu água destilada. Durante o experimento, os animais foram avaliados clinicamente e após 28 dias, sacrificados. Nos animais dos três grupos, a evolução clínica foi semelhante. Mediante análise anatomopatológica efetuada por estudo descritivo e quantitativo, foi observada presença de fibrose, cartilagem e osso igualmente nos três grupos, sempre com predomínio de tecido ósseo. O estudo biomecânico, realizado por intermédio de ensaios de flexão, demonstrou coeficiente de rigidez e carga máxima semelhantes nos três grupos. Nenhuma diferença clínica, anatomopatológica e biomecânica foi encontrada, resultando todas as fraturas em consolidação de acordo com os critérios adotados, concluindo-se, portanto, que a heparina sódica e a enoxaparina nas doses, via e tempo de administração utilizados não interfiriram na consolidação da fratura da tíbia do rato.

Estresse crônico melhora a função miocárdica sem alterar a atividade do canal-L para Ca+2 em ratos

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

Matricaria chamomilla CH12 decreases handling stress in Nelore calves

Matricaria chainomilla CH12 is a phytotherapeutic or homeopathic product, which has been used to reduce stress. Here, we examined its effect on preventing handling stress in bovines. Sixty Nelore calves were randomly distributed into two equal groups. One group was administered Matricaria chainomilla CH, in diet and the other the 'control' was not. Animals in both groups were maintained unstressed for 30 days to adjust to the feeding system and pasture, and were then stressed by constraint on the 31th, 38th, 45th and 60th experimental days. Blood samples were taken on these days after animals had been immobilization in a trunk contention for 5 min. Stress was followed by analyzing serum cortisol levels. These peaked on the 45th day and then decreased, but not to baseline, on the 60th day. on the 45th day cortisol levels were significantly lower in animals fed Matricaria chantomilla CH12, suggesting that this product reduces stress. These effects may be a consequence of its inhibiting cortisol production and its calming and anxiolytic effects.

Radiography, computed tomography and magnetic resonance imaging at 0.5 Tesla of mechanically inducedosteoarthritis in rabbit knees

In the present experimental study we assessed induced osteoarthritis data in rabbits, compared three diagnostic methods, i.e., radiography (XR), computed tomography (CT) and magnetic resonance imaging (MRI), and correlated the imaging findings with those obtained by macroscopic evaluation. Ten young female rabbits of the Norfolk breed were used. Seven rabbits had the right knee immobilized in extension for a period of 12 weeks (immobilized group), and three others did not have a limb immobilized and were maintained under the same conditions (control group). Alterations observed by XR, CT and MRI after the period of immobilization were osteophytes, osteochondral lesions, increase and decrease of joint space, all of them present both in the immobilized and non-immobilized contralateral limbs. However, a significantly higher score was obtained for the immobilized limbs (XT: P = 0.016, CT: P = 0.031, MRI: P = 0.0156). All imaging methods were able to detect osteoarthritis changes after the 12 weeks of immobilization. Macroscopic evaluation identified increased thickening of joint capsule, proliferative and connective tissue in the femoropatellar joint, and irregularities of articular cartilage, especially in immobilized knees. The differences among XR, CT and MRI were not statistically significant for the immobilized knees. However, MRI using a 0.5 Tesla scanner was statistically different from CT and XR for the non-immobilized contralateral knees. We conclude that the three methods detected osteoarthritis lesions in rabbit knees, but MRI was less sensitive than XR and CT in detecting lesions compatible with initial osteoarthritis. Since none of the techniques revealed all the lesions, it is important to use all methods to establish an accurate diagnosis.