The ubiquitin-proteasome system in Strongyloididae. Biochemical evidence for developmentally regulated proteolysis in Strongyloides venezuelensis

Nematode parasites from the genus Strongyloides spp. are important pathogens of the intestinal mucosa of animals and humans. Their complex life cycles involve alternating developmental adaptations between larvae stages and the adult parthenogenetic female. Here, we report, primarily through homology-based searching, the existence of the major components of the ubiquitin-proteasome system in this genus, using the available EST data from S. ratti, S. stercoralis, and Parastrongyloides trichosuri. In this study, S. venezuelensis was used as our model organism for detection of proteasome activity and ubiquitinated substrates in cytosolic preparations from the L3 larvae and the adult female. Marked differences in proteasome capabilities were found when these two stages were compared. A preference for degradation of chymotryptic synthetic peptides was found in both stages with the adult exhibiting a higher rate of hydrolysis compared to the larvae. Due to the high evolutionary conservation of proteasome alpha subunits, an anti-human proteasome antibody was able to recognize proteasome subunits in these preparations by Western blotting, supporting the proposal that the activity of the ubiqutin-proteasome system is developmentally regulated in this nematode.

CCR2 receptor is essential to activate microbicidal mechanisms to control Toxoplasma gondii infection in the central nervous system

Chemokines comprise a structurally related family of cytokines that regulate leukocyte trafficking. Because infection with Toxoplasma gondii can induce an important inflammatory reaction that, if left uncontrolled, can lead to death, we investigated the role of the chemokine receptor CCR2 in T gondii infection. We orally infected CCR2(-/-) mice with five ME-49 T gondii cysts and monitored morbidity, survival, and immune response thereafter. The CCR2(-/-) mice displayed higher susceptibility to infection as all mice died on day 28 after infection. Despite similar Th1 responses, a more evident anti-inflammatory response was induced in the peripheral organs of CCR2(-/-) mice compared with wild-type C57BL/6 mice. Additionally, CCR2-/- mice presented greater parasitism and a milder inflammatory reaction in their peripheral organs with lesser CD4(+) and MAC-1(+) and greater CD8(+) cell migration. The parasite load decreased in these organs in CCR2(-/-) mice but remained uncontrolled in the central nervous system. Additionally, we observed down-regulated inducible nitric oxide synthase expression in peripheral organs from CCR2(-/-) mice that was associated with a small nitric oxide production by spleen macrophages. In conclusion, in the absence of CCR2, another mechanism is activated to control tissue parasitism in peripheral organs. Nevertheless, CCR2 is essential for the activation of microbicidal mediators that control T gondii replication in the central nervous system.

Participation of kallikrein-kinin system in different pathologies

The general description of kinins refers to these peptides as molecules involved in vascular tone regulation and inflammation. Nevertheless, in the last years a series of, evidences has shown that local hormonal systems, such as the kallikrein-kinin system, may be differently regulated and are of pivotal importance to pathophysiological control. The combined interpretations of many recent studies allow us to conclude that the kallikrein-kinin system plays broader and richer roles than those classically described until recently. In this review, we report findings concerning the participation of the kallikrein-kinin system in inflammation, cancer, and in pathologies related to cardiovascular, renal and central nervous systems. (c) 2007 Elsevier B.V. All rights reserved.

In pursuit of prognostic factors in children with pilocytic astrocytomas

This study described a 23-year experience in the treatment of children with pilocytic astrocytomas (piloA) with the aim of identifying putative clinical, histopathological, and/or immunohistochemical features that could be related to the outcome of these patients. Clinical data of 31 patients under 18 years of age with piloA were obtained from 1984 to 2006. The mean age at the time of surgery was 7.8 +/- 4.2 years (1 to 17 years), and the mean follow-up was 5.7 +/- 5.4 years (1 to 20 years). The most common site of tumor formation was the cerebellum (17), followed by brainstem (4), optic chiasmatic hypothalamic region (4), cerebral hemisphere (3), cervical spinal cord (2), and optic nerve (1). Gross total resection (GTR) was achieved in 23 (74.1%), mainly in those with tumors located in the cerebellum and cerebral hemispheres (P = 0.02). The global mortality rate was 6.4%. Nine patients were reoperated. Rosenthal fibers, eosinophilic granular bodies, microvascular proliferation, and lymphocytic infiltration were observed in most cases. The mean Ki-67LI was 4.4 +/- 4.5%. In all cases, Gal-3 expression in tumor cells was observed with variable staining pattern. Aside from GTR, no other clinical, histopathological, or immunohistochemical features were found to be related to the prognosis. We postulate that strict follow-up is recommended if piloA is associated with high mitotic activity/Ki67-LI, or if GTR cannot be achieved at surgery. Tumor recurrence or progression of the residual lesion should be strictly observed. In some aspects, childhood piloA remains an enigmatic tumor.

Comparative role of neuropsychological testing in the presurgical evaluation of children with medically intractable epilepsies

In the present study, we evaluated the preoperative demographic, clinical, and neuropsychological variables that could predict postoperative seizure outcome in a group of pediatric epileptic patients. We studied 40 consecutive pediatric patients, ages ranging from 6 to 16 years, that underwent resective surgery for the treatment of medically intractable epilepsy at the Clinical Hospital of RibeirA o pound Preto School of Medicine. We performed ictal electroencephalography (EEG), interictal EEG, magnetic resonance imaging (MRI), and a preoperative neuropsychological assessment in the presurgical workup. The following factors were correlated with seizure outcome: (1) duration of epilepsy, (2) surgery localization, (3) localized Neuropsychological (NPS) Evaluation, (4) ictal EEG, (5) interictal EEG, and (6) MRI. Mental retardation, NPS tests, and the other demographic variables failed to correlate with seizure reduction. The identification of predictor variables of epilepsy surgery outcome could improve the epileptic prognosis and guarantee the children`s full potential development.

Evaluation of the respiratory muscle strength of cirrhotic patients: Relationship with Child-Turcotte-Pugh scoring system

Pulmonary abnormalities are observed in chronic hepatopathy. The measurement of the maximum inspiratory and expiratory pressure may evaluate lung function and the risks associated with hepatic transplantation. Thus, the present work sought to evaluate the respiratory muscle strength of 29 patients between 17 and 63 years old who were enrolled for liver transplantation. The patients were classified according to Child-Turcotte-Pugh score as A, B, or C, and also according to a physiotherapeutic evaluation, which included measurement of respiratory muscle strength by means of a digital manovactrometer, which determines the maximum inspiratory pressure (MaxIP) and the maximum expiratory pressure (MaxEP). The tests were performed with seated individuals having their nostrils obstructed by a nasal clip. The MaxIP was measured during the effort initiated in the residual volume, whereas the MaxEP was measured during the effort initiated in the total pulmonary capacity, keeping pressures stable for at least 1 second. The statistical analysis was performed through using the Mann-Whitney test with a 5% level of significance. The MaxIP values of Child A 95.5 +/- 40.507 cm H2O (average +/- DP) and Child B 87.2 +/- 35.02 patients were higher than those for Child C patients (34.83 +/- 3.68; P <.05). Similar results were observed for the MaxEP of Child A and B groups (116.25 +/- 31.98 and 97.28 +/- 31.08, respectively; P <.05), versus the Child C group (48.16 +/- 22.60). Between groups A and B, the MaxEP were similar (P >.05). We concluded that Child C patients display muscle weakness significantly greater than that of subjects classified as Child A or B.

Transcriptional Response of Peripheral Lymphocytes to Early Fibrosarcoma: A Model System for Cancer Detection Based on Hybridization Signatures

Since circulating leukocytes, mainly B and T cells, continuously maintain vigilant and comprehensive immune surveillance, these cells could be used as reporters for signs of infection or other pathologies, including cancer. Activated lymphocyte clones trigger a sensitive transcriptional response, which could be identified by gene expression profiling. To assess this hypothesis, we conducted microarray analysis of the gene expression profile of lymphocytes isolated from immunocompetent BALB/c mice subcutaneously injected with different numbers of tumorigenic B61 fibrosarcoma cells. Flow cytometry demonstrated that the number of circulating T (CD3(+)CD4(+) or CD3(+)CD8(+)) or B (CD19(+)) cells did not change. However, the lymphocytes isolated from tumor cell-injected animals expressed a unique transcriptional profile that was identifiable before the development of a palpable tumor mass. This finding demonstrates that the transcriptional response appears before alterations in the main lymphocyte subsets and that the gene expression profile of peripheral lymphocytes can serve as a sensitive and accurate method for the early detection of cancer. Exp Biol Med 234:802-812, 2009

The Effect of Repetitive Pilot-Hole Use on the Insertion Torque and Pullout Strength of Vertebral System Screws

Study Design. In vitro biomechanical investigation of the screw-holding capacity. Objective. To evaluate the effect of repetitive screw-hole use on the insertional torque and retentive strength of vertebral system screws. Summary and Background Data. Placement and removal of vertebral system screws is sometimes necessary during the surgical procedures in order to assess the walls of the pilot hole. This procedure may compromise the holding capacity of the implant. Methods. Screws with outer diameter measuring 5, 6, and 7 mm were inserted into wood, polyurethane, polyethylene, and cancellous bone cylindrical blocks. The pilot holes were made with drills of a smaller, equal, or wider diameter than the inner screw diameter. Three experimental groups were established based on the number of insertions and reinsertions of the screws and subgroups were created according to the outer diameter of the screw and the diameter of the pilot hole used. Results. A reduction of screw-holding capacity was observed between the first and the following insertions regardless the anchorage material. The pattern of reduction of retentive strength was not similar to the pattern of torque reduction. The pullout strength was more pronounced between the first and the last insertions, while the torque decreased more proportionally from the first to the last insertions. Conclusion. Insertion and reinsertion of the screws of the vertebral fixation system used in the present study reduced the insertion torque and screw purchase.

Frequency and prognostic relevance of cancer testis antigen 45 expression in multiple myeloma

Objective. This study aims to analyze the expression of cancer testis antigen 45 (CT45) in normal tissues and in plasma cell disorders and to identify possible associations with clinical data and prognosis in multiple myeloma (MM) patients. Materials and Methods. Expression of CT45 was studied in 20 normal tissues (testis, placenta, skeletal muscle, bladder, lung, spleen, heart, brain and fetal brain, thymus, uterus, stomach, mammary gland, pancreas, prostate, small intestine, kidney, adrenal gland, spinal cord, colon, and one pool of 10 normal bone marrow samples) and bone marrow aspirates from 3 monoclonal gammopathies of undetermined significance, 5 solitary plasmacytomas, 61 newly diagnosed MM patients and MM cell line U266 by reverse transcriptase polymerase chain reaction. Results. CT45 was positive in 3 of 20 (15%) normal tissues tested: lung, brain (both fetal and adult), and spinal cord. Among monoclonal gammopathies, CT45 was positive in 2 of 5 (40%) solitary plasmacytomas bone marrow aspirates, 10 of 61 (16%) MM bone marrow aspirates, and in the U266 MM cell line. Conclusions. We did not find associations between bone marrow histology and CT45 expression. However, we demonstrated for the first time that positive expression of CT45 was associated with poor prognostic (international Staging System) and poor outcomes in MM patients, meaning that CT45-positive cases presented seven times more chance of worse evolution than the negative ones. (C) 2009 ISEH - Society for Hematology and Stem Cells. Published by Elsevier Inc.

Role of mixed Th1 and Th2 serum cytokines on pathogenesis and prognosis of hantavirus pulmonary syndrome

The hantavirus pulmonary syndrome (HPS) is an emerging syndrome in the Americas. The disease results from intense immune activation and changes in vascular permeability. The aim of this study was to determine the profile of serum cytokines in HPS patients looking for correlation with the clinical parameters, severity and outcome of illness. Studying 21 HPS patients, we found that IL-6 may have an important role in the pathogenesis of HPS, being associated with fatal outcome. Our results also support a mixed Th1/Th2 immune response during the course of HPS and that the magnitude of Th1 response effector cytokines is correlated to HPS severity. The decreased levels of TGF-beta observed in HPS patients suggest that immunoregulatory activity could be damaged in these patients. (c) 2008 Elsevier Masson SAS. All rights reserved.