946 resultados para Paramagnetic fluid


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Dissertação para obtenção do Grau de Doutor em Química Sustentável

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IEEE International Conference on Cyber Physical Systems, Networks and Applications (CPSNA'15), Hong Kong, China.

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The goal of this short communication is to report the uncommon presence of intracellular amastigotes of Leishmania in peritoneal fluid of a dog with leishmaniasis from Alagoas State, Brazil. Physical examination of an adult male rottweiler suspected to be suffering of leishmaniasis revealed severe loss of weight, ascitis, splenomegaly, moderately enlarged lymph nodes, onychogryphosis, generalized alopecia, skin ulcers on the posterior limbs, and conjunctivitis. Samples of bone marrow, popliteal lymph node, skin ulcer, and peritoneal fluid were collected and smears of each sample were prepared and stained with hematoxylin and eosin. Numerous amastigotes were detected in bone marrow, popliteal lymph node, and skin ulcer smears. Smears of peritoneal fluid revealed the unusual presence of several free and intracellular amastigotes of Leishmania. Future studies are needed to determine whether the cytology of ascitic fluid represents a useful tool for diagnosis Leishmania infection in ascitic dogs, particularly in those living in areas where canine leishmaniasis is enzootic.

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Chronic meningitism is a less frequent manifestation of neurocysticercosis caused by Taenia solium cysticerci. In the present study we used Co-agglutination (Co-A), a simple and rapid slide agglutination test to detect specific Cysticercus antigen in the 67 cerebrospinal fluid (CSF) samples from patients with chronic meningitis of unknown etiology. The results were compared with that of ELISA for detection of antibodies. Among these samples four (5.97%) were positive for Cysticercus antigen by Co-A test and six (8.95%) were positive for antibodies by ELISA. Two samples were positive by both Co-A and ELISA, two were positive only by Co-A and four were positive only by ELISA. In the present study, although Cysticercus antigen and antibodies were present in CSF samples from eight (11.94%) patients, we cannot affirm that all the cases of chronic meningitis are due to cysticercosis, but for any case of chronic meningitis of unknown origin, it would be useful to consider the possibility of cysticercal meningitis.

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The aim of the present study is to evaluate cyst wall and protoscolex as an alternate source of antigen in serodiagnosis of cystic echinococcosis (CE). A total of 90 blood samples, 30 each of confirmed CE cases, disease controls and healthy controls were collected. Dot-ELISA using cyst wall, protoscolex and cyst fluid were used to demonstrate anti-hydatid antibodies. The sensitivity of Dot-ELISA using cyst wall, protoscolex and cyst fluid was 96.66%, 86.66% and 93.33% respectively and the specificity of the assay was 70% for Dot-ELISA using cyst fluid, protoscolex and cyst wall antigens. Results of the present study show that cyst wall and protoscolex can also be an useful source of antigen in detection of hydatid antibodies in the serodiagnosis of CE.

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Abstract In a few rare diseases, specialised studies in cerebrospinal fluid (CSF) are required to identify the underlying metabolic disorder. We aimed to explore the possibility of detecting key synaptic proteins in the CSF, in particular dopaminergic and gabaergic, as new procedures that could be useful for both pathophysiological and diagnostic purposes in investigation of inherited disorders of neurotransmission. Dopamine receptor type 2 (D2R), dopamine transporter (DAT) and vesicular monoamine transporter type 2 (VMAT2) were analysed in CSF samplesfrom 30 healthy controls (11 days to 17 years) by western blot analysis. Because VMAT2 was the only protein with intracellular localisation, and in order to compare results, GABA vesicular transporter, which is another intracellular protein, was also studied. Spearman’s correlation and Student’s t tests were applied to compare optical density signals between different proteins. All these synaptic proteins could be easily detected and quantified in the CSF. DAT, D2R and GABA VT expression decrease with age, particularly in the first months of life, reflecting the expected intense synaptic activity and neuronal circuitry formation. A statistically significant relationship was found between D2R and DAT expression, reinforcing the previous evidence of DAT regulation by D2R. To our knowledge, there are no previous studies on human CSF reporting a reliable analysis of these proteins. These kinds of studies could help elucidate new causes of disturbed dopaminergic and gabaergic transmission as well as understanding different responses to L-dopa in inherited disorders affecting dopamine metabolism. Moreover, this approach to synaptic activity in vivo can be extended to different groups of proteins and diseases.

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The question of whether HIV-1 RNA in cerebrospinal fluid (CSF) is derived from viral replication in the central nervous system or simply reflects the transit of infected lymphocytes from the blood compartment has long been a matter of debate. Some studies found no correlation between CSF and plasma viral load, whereas others did. The lack of a correlation between the two compartments suggests that the presence of HIV-1 RNA is not simply due to the passive passage of the virus from blood to CSF but rather due to intrathecal replication. To evaluate the correlation between plasma and CSF HIV-1 RNA levels and to identify situations in which there is no correlation between the two compartments, seventy patients were prospectively studied. The association between CSF and plasma viral load was evaluated in the total population and in subgroups of patients with similar characteristics. A correlation between the CSF and plasma compartments was observed for patients undergoing highly active antiretroviral therapy (HAART), those with a CD4 T lymphocyte count lower than 200 cells/mm³, and those with increased CSF protein content. On the other hand, no correlation was observed for patients without adequate virological control, who had a CD4 count higher than 200 cells/mm³ and who did not use HAART. The correlation between the two compartments observed in some patients suggests that CSF HIV-1 RNA levels may reflect plasma levels in these subjects. In contrast, the lack of a correlation between the two compartments in patients who were not on HAART and who had normal CSF proteins and a poor virological control possibly indicates compartmentalization of the virus in CSF and, consequently, plasma-independent intrathecal viral replication.

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SUMMARY Cerebral toxoplasmosis can be highly debilitating and occasionally fatal in persons with immune system deficiencies. In this study, we evaluated the Toxoplasma gondii-specific IgG subclass antibody response in 19 cerebrospinal fluid (CSF) samples from patients with cerebral toxoplasmosis who had a positive IgG anti-T. gondii ELISA standardized with a cyst antigen preparation. There were no significant differences between the rates of positivity and the antibody concentrations (arithmetic means of the ELISA absorbances, MEA) for IgG1 and IgG2, but the rates of positivity and MEA values for these two IgG subclasses were significantly higher than those for IgG3 and IgG4. The marked IgG2 response in CSF from patients with cerebral toxoplasmosis merits further investigation.

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Acc. Chem. Res., 2006, 39 (10), pp 788–796 DOI: 10.1021/ar050104k

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Tyrosine hydroxylase (TH) deficiency is an inborn error of dopamine biosynthesis and a cause of early parkinsonism. Two clinical phenotypes have been described. Type “B”: early onset severe encephalopathy; type “A”: later onset, less severe and better response to L-dopa. We aimed to study the expression of several key dopaminergic and gabaergic synaptic proteins in the cerebrospinal fluid (CSF) of a series of patients with TH deficiency and their possible relation with the clinical phenotype and response to L-DOPA. Dopamine transporter (DAT), D2-receptor and vesicularmonoamine transporter (VMAT2)weremeasured in the CSF of 10 subjectswith THdeficiency byWestern blot analysis. In 3 patients, data of pre- and post-treatmentwith L-DOPA were available, and in one of them, GABA vesicular transporter was determined. Results were compared to an age-matched control population. The concentration of D2-receptors in CSFwas significantly higher in patients with TH deficiency than in controls. Similarly, DAT and vesicular monoamine transporter type 2 were up-regulated. Studies performed before LDOPA, and on L-DOPA therapy showed a paradoxical response with D2 receptor expression increase as L-Dopa doses and homovanillic concentration gradually raised in a B phenotype patient. The opposite results were found in two patients with A phenotype. However, this is a very small sample, and further studies are needed to conclude robust differences between phenotypes. Synaptic proteins are detectable in the CSF and their quantification can be useful for understanding the pathophysiology of neurotransmitter defects and potentially to adjust and personalize treatments in the future.

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We reviewed the cerebrospinal fluid (CSF) syndromes of 100 consecutive HIV-positive patients presenting acute consciousness compromise in emergency rooms, and correlated them with clinical data. The most frequent CSF syndromes were: absolute protein-cytological dissociation (21), viral (19), neurocryptococcosis (7), relative protein-cytological dissociation (6) and septic (4), moderate hypoglycorrachia (4), severe hypoglycorrachia (4) and hydroelectrolytic disturbance (3). One fifth of the patients had CSF syndromes considered sufficient for diagnosis or an immediate clinical decision. The most common clinical data were infective and neurological. There was little correlation between the clinical data and the CSF syndromes. We conclude that in HIV-positive individuals presenting acute consciousness disturbances there are frequently non-specific results in the CSF analysis that must be weighed against a detailed history and thorough physical examination. Taking this into account, in about one fifth of cases the CSF analysis can offer useful information for treatment.

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Toxoplasmosis is one of the most common infections all over the world. Most cases are asymptomatic, except in immunosuppressed individuals and fetuses, which can be seriously damaged. Prenatal diagnosis should be made as soon as possible since treatment of the mother can minimize fetal sequelae. Our aim in this study was to test the polymerase chain reaction technique (PCR) in 86 samples of amniotic fluid from women who seroconverted during pregnancy. DNA was amplified using external primers and, in a second step, internal primers, in a nested PCR system. Samples were also inoculated into mice and the newborn were evaluated by T. gondii serology, skull x-ray, transfontanel ultrasound, fundoscopic examination, lumbar puncture and clinical examination. PCR was positive in seven cases and negative in 79. Among PCR-positive cases, two were negative by inoculation into mice and by clinical evaluation; among PCR-negative ones, three had clinical evidence of toxoplasmosis and one was positive after inoculation into mice. PCR showed values of sensitivity = 62.5% and specificity = 97.4%; the values of inoculation into mice where 42.9% and 100%, respectively. Although PCR should not be used alone for prenatal diagnosis of congenital toxoplasmosis, it is a promising method and deserves more studies to improve its efficacy.

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The efficacy of whole parasite and vesicular fluid antigen extracts from Taenia solium and Taenia crassiceps cysticerci for immunodiagnosis of neurocysticercosis was evaluated using ELISA on cerebrospinal fluid samples. Anticysticercal IgG antibodies were assayed in cerebrospinal fluid samples from 23 patients with neurocysticercosis and 35 patients with other neurological disorders. The ELISA reaction for the whole Taenia solium cysticercal extract showed 91.3% sensitivity and 94.3% specificity, whereas the sensitivity and specificity of the ELISA for the whole Taenia crassiceps cysticercal extract were 87% and 94.3%, respectively. The ELISA reactions for vesicular fluid from Taenia solium or Taenia crassiceps showed 91.3% sensitivity and 97.1% specificity. Considering the results obtained from the four antigen preparations, vesicular fluid from Taenia solium and Taenia crassiceps cysticerci may be useful as a source of antigens for immunological reactions that are used for detecting specific antibodies in cerebrospinal fluid samples from patients with neurocysticercosis.

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Introduction Toxoplasmosis may be life-threatening in fetuses and in immune-deficient patients. Conventional laboratory diagnosis of toxoplasmosis is based on the presence of IgM and IgG anti-Toxoplasma gondii antibodies; however, molecular techniques have emerged as alternative tools due to their increased sensitivity. The aim of this study was to compare the performance of 4 PCR-based methods for the laboratory diagnosis of toxoplasmosis. One hundred pregnant women who seroconverted during pregnancy were included in the study. The definition of cases was based on a 12-month follow-up of the infants. Methods Amniotic fluid samples were submitted to DNA extraction and amplification by the following 4 Toxoplasma techniques performed with parasite B1 gene primers: conventional PCR, nested-PCR, multiplex-nested-PCR, and real-time PCR. Seven parameters were analyzed, sensitivity (Se), specificity (Sp), positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio (PLR), negative likelihood ratio (NLR) and efficiency (Ef). Results Fifty-nine of the 100 infants had toxoplasmosis; 42 (71.2%) had IgM antibodies at birth but were asymptomatic, and the remaining 17 cases had non-detectable IgM antibodies but high IgG antibody titers that were associated with retinochoroiditis in 8 (13.5%) cases, abnormal cranial ultrasound in 5 (8.5%) cases, and signs/symptoms suggestive of infection in 4 (6.8%) cases. The conventional PCR assay detected 50 cases (9 false-negatives), nested-PCR detected 58 cases (1 false-negative and 4 false-positives), multiplex-nested-PCR detected 57 cases (2 false-negatives), and real-time-PCR detected 58 cases (1 false-negative). Conclusions The real-time PCR assay was the best-performing technique based on the parameters of Se (98.3%), Sp (100%), PPV (100%), NPV (97.6%), PLR (∞), NLR (0.017), and Ef (99%).