Anti-leishmania antibodies in cerebrospinal fluid from dogs with visceral leishmaniasis

Visceral leishmaniasis in Brazil is caused by Leishmania (Leishmania) chagasi and the dog is its most important reservoir. The clinical features in dogs include loss of weight, lymphadenopathy, renal failure, skin lesions, fever, hypergammaglobulinemia, hepatosplenomegaly, anemia, and, rarely, neurological symptoms. Most infected animals develop active disease, characterized by high anti-leishmania antibody titers and depressed lymphoproliferative ability. Antibody production is not primarily important for protection but might be involved in the pathogenesis of tissue lesions. An ELISA test was used to determine if there is an association between neurological symptoms and the presence of anti-L. chagasi antibodies in cerebrospinal fluid (CSF). Thirty serum and CSF samples from symptomatic mixed breed dogs (three with neurological symptoms) from a region of high incidence of visceral leishmaniasis in Brazil were examined for antibody using total parasite antigen and anti-dog IgG peroxidase conjugate. A high level of L. chagasi antibodies was observed in sera (mean absorbance ± SD, 1.939 ± 0.405; negative control, N = 20, 0.154 ± 0.074) and CSF (1.571 ± 0.532; negative control, N = 10, 0.0195 ± 0.040) from all animals studied. This observation suggests that L. chagasi can cause breakdown of filtration barriers and the transfer of antibodies and antigens from the blood to the CSF compartment. No correlation was observed between antibody titer in CSF and neurological symptoms.

Genesis and Evolution of Brittle Structures In Southwestern Finland and Western South Africa. Insights into Fault Reactivation, Fluid Flow and Structural Maturity in Precambrian Cratons

The bedrock of old crystalline cratons is characteristically saturated with brittle structures formed during successive superimposed episodes of deformation and under varying stress regimes. As a result, the crust effectively deforms through the reactivation of pre-existing structures rather than by through the activation, or generation, of new ones, and is said to be in a state of 'structural maturity'. By combining data from Olkiluoto Island, southwestern Finland, which has been investigated as the potential site of a deep geological repository for high-level nuclear waste, with observations from southern Sweden, it can be concluded that the southern part of the Svecofennian shield had already attained structural maturity during the Mesoproterozoic era. This indicates that the phase of activation of the crust, i.e. the time interval during which new fractures were generated, was brief in comparison to the subsequent reactivation phase. Structural maturity of the bedrock was also attained relatively rapidly in Namaqualand, western South Africa, after the formation of first brittle structures during Neoproterozoic time. Subsequent brittle deformation in Namaqualand was controlled by the reactivation of pre-existing strike-slip faults.In such settings, seismic events are likely to occur through reactivation of pre-existing zones that are favourably oriented with respect to prevailing stresses. In Namaqualand, this is shown for present day seismicity by slip tendency analysis, and at Olkiluoto, for a Neoproterozoic earthquake reactivating a Mesoproterozoic fault. By combining detailed field observations with the results of paleostress inversions and relative and absolute time constraints, seven distinctm superimposed paleostress regimes have been recognized in the Olkiluoto region. From oldest to youngest these are: (1) NW-SE to NNW-SSE transpression, which prevailed soon after 1.75 Ga, when the crust had sufficiently cooled down to allow brittle deformation to occur. During this phase conjugate NNW-SSE and NE-SW striking strike-slip faults were active simultaneous with reactivation of SE-dipping low-angle shear zones and foliation planes. This was followed by (2) N-S to NE-SW transpression, which caused partial reactivation of structures formed in the first event; (3) NW-SE extension during the Gothian orogeny and at the time of rapakivi magmatism and intrusion of diabase dikes; (4) NE-SW transtension that occurred between 1.60 and 1.30 Ga and which also formed the NW-SE-trending Satakunta graben located some 20 km north of Olkiluoto. Greisen-type veins also formed during this phase. (5) NE-SW compression that postdates both the formation of the 1.56 Ga rapakivi granites and 1.27 Ga olivine diabases of the region; (6) E-W transpression during the early stages of the Mesoproterozoic Sveconorwegian orogeny and which also predated (7) almost coaxial E-W extension attributed to the collapse of the Sveconorwegian orogeny. The kinematic analysis of fracture systems in crystalline bedrock also provides a robust framework for evaluating fluid-rock interaction in the brittle regime; this is essential in assessment of bedrock integrity for numerous geo-engineering applications, including groundwater management, transient or permanent CO2 storage and site investigations for permanent waste disposal. Investigations at Olkiluoto revealed that fluid flow along fractures is coupled with low normal tractions due to in-situ stresses and thus deviates from the generally accepted critically stressed fracture concept, where fluid flow is concentrated on fractures on the verge of failure. The difference is linked to the shallow conditions of Olkiluoto - due to the low differential stresses inherent at shallow depths, fracture activation and fluid flow is controlled by dilation due to low normal tractions. At deeper settings, however, fluid flow is controlled by fracture criticality caused by large differential stress, which drives shear deformation instead of dilation.

Serum and cerebrospinal fluid concentrations of E-selectin in patients with aneurysmal subarachnoid hemorrhage

The goal of the present study was to determine concentrations of E-selectin in both cerebrospinal fluid (CSF) and serum of patients with aneurysmal subarachnoid hemorrhage (SAH) and to evaluate the correlation between the clinical parameters and E-selectin levels. Both CSF and serum samples obtained from 12 patients with aneurysmal SAH and 8 patients with hydrocephalus (control group) without any other known central nervous system disease were assayed for E-selectin by quantitative enzyme-linked immunosorbent assay and the results were compared between the two groups. Mean levels of soluble forms of E-selectin within the first 3 days and on the 5th and 7th days of SAH were 4.0 ± 7.9, 2.8 ± 5.2, and 3.1 ± 4.9 ng/ml in the patient's CSF, and 33.7 ± 9.2, 35.1 ± 7.0, and 35.2 ± 8.7 ng/ml in serum, respectively. In contrast, mean E-selectin levels were 0.1 ± 0.2 ng/ml in CSF and 8.7 ± 5.0 ng/ml in serum of control patients. The difference between groups was statistically significant regarding both CSF and serum E-selectin levels (P < 0.05). Thus, we have demonstrated a marked increase of E-selectin concentration in both CSF and serum of patients with aneurysmal SAH compared with control and suggest that blocking the interaction between E-selectin and vascular endothelium may have a beneficial effect on vasospasms.

Serum and cerebrospinal fluid S100B concentrations in patients with neurocysticercosis

The clinical manifestations of neurocysticercosis (NC) are varied and depend on the number and location of cysts, as well as on the host immune response. Symptoms usually occur in NC when cysticerci enter a degenerative course associated with an inflammatory response. The expression of brain damage markers may be expected to increase during this phase. S100B is a calcium-binding protein produced and released predominantly by astrocytes that has been used as a marker of reactive gliosis and astrocytic death in many pathological conditions. The aim of the present study was to investigate the levels of S100B in patients in different phases of NC evolution. Cerebrospinal fluid and serum S100B concentrations were measured in 25 patients with NC: 14 patients with degenerative cysts (D), 8 patients with viable cysts (V) and 3 patients with inactive cysts. All NC patients, except 1, had five or less cysts. In most of them, symptoms had been present for at least 1 month before sample collection. Samples from 8 normal controls (C) were also assayed. The albumin quotient was used to estimate the blood-brain barrier permeability. There were no significant differences in serum (P = 0.5) or cerebrospinal fluid (P = 0.91) S100B levels among the V, D, and C groups. These findings suggest that parenchymal changes associated with a relatively small number of degenerating cysts probably have a negligible impact on glial tissue.

Chemokines in the cerebrospinal fluid of patients with active and stable relapsing-remitting multiple sclerosis

Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease of the human central nervous system. Although its etiology is unknown, the accumulation and activation of mononuclear cells in the central nervous system are crucial to its pathogenesis. Chemokines have been proposed to play a major role in the recruitment and activation of leukocytes in inflammatory sites. They are divided into subfamilies on the basis of the location of conserved cysteine residues. We determined the levels of some CC and CXC chemokines in the cerebrospinal fluid (CSF) of 23 relapsing-remitting MS patients under interferon-ß-1a therapy and 16 control subjects using ELISA. MS patients were categorized as having active or stable disease. CXCL10 was significantly increased in the CSF of active MS patients (mean ± SEM, 369.5 ± 69.3 pg/mL) when compared with controls (178.5 ± 29.1 pg/mL, P < 0.05). CSF levels of CCL2 were significantly lower in active MS (144.7 ± 14.4 pg/mL) than in controls (237.1 ± 16.4 pg/mL, P < 0.01). There was no difference in the concentration of CCL2 and CXCL10 between patients with stable MS and controls. CCL5 was not detectable in the CSF of most patients or controls. The qualitative and quantitative differences of chemokines in CSF during relapses of MS suggest that they may be useful as a marker of disease activity and of the mechanisms involved in the pathogenesis of the disease.

New conserved vorticity integrals for moving surfaces in multi-dimensional fluid flow

For inviscid fluid flow in any n-dimensional Riemannian manifold, new conserved vorticity integrals generalizing helicity, enstrophy, and entropy circulation are derived for lower-dimensional surfaces that move along fluid streamlines. Conditions are determined for which the integrals yield constants of motion for the fluid. In the case when an inviscid fluid is isentropic, these new constants of motion generalize Kelvin’s circulation theorem from closed loops to closed surfaces of any dimension.

The acoustic signature of fluid flow in complex porous media

Effective medium approximations for the frequency-dependent and complex-valued effective stiffness tensors of cracked/ porous rocks with multiple solid constituents are developed on the basis of the T-matrix approach (based on integral equation methods for quasi-static composites), the elastic - viscoelastic correspondence principle, and a unified treatment of the local and global flow mechanisms, which is consistent with the principle of fluid mass conservation. The main advantage of using the T-matrix approach, rather than the first-order approach of Eshelby or the second-order approach of Hudson, is that it produces physically plausible results even when the volume concentrations of inclusions or cavities are no longer small. The new formulae, which operates with an arbitrary homogeneous (anisotropic) reference medium and contains terms of all order in the volume concentrations of solid particles and communicating cavities, take explicitly account of inclusion shape and spatial distribution independently. We show analytically that an expansion of the T-matrix formulae to first order in the volume concentration of cavities (in agreement with the dilute estimate of Eshelby) has the correct dependence on the properties of the saturating fluid, in the sense that it is consistent with the Brown-Korringa relation, when the frequency is sufficiently low. We present numerical results for the (anisotropic) effective viscoelastic properties of a cracked permeable medium with finite storage porosity, indicating that the complete T-matrix formulae (including the higher-order terms) are generally consistent with the Brown-Korringa relation, at least if we assume the spatial distribution of cavities to be the same for all cavity pairs. We have found an efficient way to treat statistical correlations in the shapes and orientations of the communicating cavities, and also obtained a reasonable match between theoretical predictions (based on a dual porosity model for quartz-clay mixtures, involving relatively flat clay-related pores and more rounded quartz-related pores) and laboratory results for the ultrasonic velocity and attenuation spectra of a suite of typical reservoir rocks. (C) 2003 Elsevier B.V. All rights reserved.

Neurofilament heavy subunit in cerebrospinal fluid: A biomarker of amyotrophic lateral sclerosis?

The objectives of this study were to investigate the presence of the three neurofilament subunits, ubiquitin, proteasome and 3-nitrotyrosine, in CSF samples of ALS patients. CSF samples were obtained by lumbar puncture from 10 ALS patients and six controls. All samples were analysed by Western blotting. Results revealed that neurofilament heavy subunit was identified in 70% of ALS cases and we conclude that this subunit may be a promising biomarker for clinical diagnosis of ALS.

Boundary and internal conditions for adjoint fluid-flow problems

The ever-increasing robustness and reliability of flow-simulation methods have consolidated CFD as a major tool in virtually all branches of fluid mechanics. Traditionally, those methods have played a crucial role in the analysis of flow physics. In more recent years, though, the subject has broadened considerably, with the development of optimization and inverse design applications. Since then, the search for efficient ways to evaluate flow-sensitivity gradients has received the attention of numerous researchers. In this scenario, the adjoint method has emerged as, quite possibly, the most powerful tool for the job, which heightens the need for a clear understanding of its conceptual basis. Yet, some of its underlying aspects are still subject to debate in the literature, despite all the research that has been carried out on the method. Such is the case with the adjoint boundary and internal conditions, in particular. The present work aims to shed more light on that topic, with emphasis on the need for an internal shock condition. By following the path of previous authors, the quasi-1D Euler problem is used as a vehicle to explore those concepts. The results clearly indicate that the behavior of the adjoint solution through a shock wave ultimately depends upon the nature of the objective functional.

Evaluation of electrophoretic profile and albumin quota in the cerebrospinal fluid of dogs with distemper showing or not neurvous signs

Estudaram-se o perfil eletroforético das proteínas liquóricas e a cota de albumina em cães sem e com cinomose na fase neurológica e não-neurológica. A punção da cisterna magna para a obtenção de amostras de liquor realizou-se em 30 cães. Analisaram-se teores de proteínas totais, cota de albumina e fracionamento eletroforético das proteínas liquóricas em gel de agarose. Os resultados foram semelhantes nos cães normais e nos cães com cinomose sem sinais neurológicos e significativamente elevados no grupo de cães com cinomose apresentando sinais neurológicos. O estudo do quadro protéico do líquido cérebroespinhal foi útil e contribuiu significativamente na detecção de lesões ao sistema nervoso central e de danos à barreira hematoencefálica durante a fase neurológica da cinomose.

Physical-chemical analysis of the cerebrospinal fluid of healthy dogs submitted to different storage periods and temperatures

Disfunções envolvendo o sistema nervoso são de grande importância na Medicina Veterinária, pois tratam-se de enfermidades de elevada incidência e com poucos subsídios auxiliares no seu diagnóstico, prognóstico e na avaliação de terapias empregadas. Ainda hoje, o diagnóstico baseia-se, em grande parte, no histórico e no exame clínico neurológico. Dessa forma, a análise dos constituintes do fluido cefalorraquidiano torna-se uma das poucas alternativas de acesso clínico ao sistema nervoso central (SNC). Mesmo com a grande utilidade do exame físico-químico e citoscópico do liquor na neurologia veterinária, poucos são os estudos sobre a estabilidade dos seus constituintes sob estocagem. Dessa forma, o presente trabalho teve como finalidade verificar a influência da temperatura e do tempo de conservação nas características físico-químicas do liquor de cães hígidos. Para tanto, foram coletadas amostras de LCR, através da punção da cisterna cerebelo-medular de cães clinicamente sadios, as quais foram submetidas à análise da densidade específica, do pH, da glicorraquia, das proteínas totais e das atividades das enzimas creatina quinase (CK) e aspartato aminotransferase (AST), após conservá-las em diferentes temperaturas (25°C, 4°C e -4°C) e por diferentes períodos de tempo (logo após a colheita, 24 horas, 48 horas, uma semana e um mês). Dentre os resultados obtidos, foi possível verificar, principalmente, que houve estabilidade dos parâmetros estudados por até um mês de estocagem nas amostras mantidas sob a temperaturas de congelamento de -4°C.