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A L Teixeira

Publications and source records attributed to A L Teixeira.

16 recordsLinked to original sources
PubMed2006

Eotaxin-2 in sputum cell culture to evaluate asthma inflammation.

The aim of the present study was to elucidate whether the culture of cells recovered from induced sputum may represent a suitable model to evaluate cytokine and chemokine production by airway inflammatory cells. Sputum induction was performed in 21 normal subjects and 30 asthmatic patients. A total of 21 out of the 30 asthmatic patients were taking inhaled corticosteroids, while the remaining nine were steroid-naive asthmatics. The steroid-naive group was evaluated before and after a 14-day treatment with oral prednisone (40 mg.day(-1)). The supernatant of lysed and centrifuged sputum and the supernatant of sputum cell culture were analysed. Tumour necrosis factor-alpha, interleukin (IL)-8 (CXCL8), IL-1beta, IL-13 and eotaxin-2 (CCL24) concentrations were determined by specific ELISA. Eotaxin-2 production by cell culture was higher in the asthma group (131+/-108 pg.mL(-1)) than in the control group (36+/-41 pg.mL(-1)) and treatment with oral corticosteroids eliminated this difference. In addition, reduction of eotaxin-2 levels by corticosteroid treatment was greater in cell culture (81.3% reduction) than in sputum (26.4%). There was correlation between the decrease in eotaxin-2 production and the decrease in blood eosinophil number and between eotaxin-2 and eosinophils in sputum. Eotaxin-2 may play an important role in asthma and the response to corticosteroid treatment suggests that analysis of sputum cell culture is relevant as an inflammatory parameter.

Administration, Inhalation↗
PubMed2006

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.

Adjuvants, Immunologic↗
PubMed2006

Concentrations of CXCL8, CXCL9 and sTNFR1 in plasma of patients with pulmonary tuberculosis undergoing treatment.

BACKGROUND: Chemokines are a class of cytokines with chemotactic properties shown to be induced by M. tuberculosis or its antigens in vitro and in experimental infection in vivo. A few studies have also demonstrated the expression of chemokines in clinical samples of patients with active tuberculosis (TB). In the present work, we measured the concentration of chemokines in plasma samples of HIV-negative patients with pulmonary tuberculosis at different stages of chemotherapy. For comparison, we also evaluated the levels of sTNFR1 and TNF-alpha. METHODS: Cytokines and chemokines were measured by ELISA in healthy individuals and patients with active pulmonary TB at different stages of treatment. RESULTS: The concentrations of CXCL8, CXCL9 and sTNFR1 were elevated in patients with active pulmonary TB but returned to background levels at 4-6 months of chemotherapy. The concentration of CCL11 was elevated in patients with active pulmonary tuberculosis when compared to control and remained elevated throughout the specific therapy. There was no difference in the plasma concentration of CCL2 and CXCL10 between pulmonary TB patients and control subjects. CONCLUSION: Measurement of the CXCL8, CXCL9 and sTNFR1 may be useful to assess response to treatment in pulmonary TB patients.

Cytokines↗
PubMed2006

Levels of serum chemokines discriminate clinical myelopathy associated with human T lymphotropic virus type 1 (HTLV-1)/tropical spastic paraparesis (HAM/TSP) disease from HTLV-1 carrier state.

Approximately 5% of people infected with human T lymphotropic virus type 1 (HTLV-1) develop clinical myelopathy or tropical spastic paraparesis (HAM/TSP) that is associated with high-levels of Th1 cytokines, interferon (IFN)-gamma and tumour necrosis factor (TNF)-alpha. Chemokines are known to induce cytokine secretion and direct the trafficking of immune cells to sites of disease. The present study measured serum chemokines correlated with autonomously released IFN-gamma in cell cultures. HTLV-1 infection was defined by enzyme-linked immunosorbent assay (ELISA) and confirmed by Western blot. Subjects included HTLV-1 carriers (n = 56), patients with HAM/TSP (n = 31) and healthy HTLV-1 seronegative volunteer controls (n = 20). Serum chemokines and IFN-gamma autonomously released by mononuclear cells in culture were quantified by ELISA. Compared to HTLV-1 carriers, serum chemokines in HAM/TSP patients showed significantly increased levels of CXCL9 and CXCL10, significantly diminished levels of CCL2 and similar amounts of CCL11 and CCL24. In contrast, CCL11 and CCL24 were significantly lower in serum of HAM/TSP patients than either control. IFN-gamma was positively correlated with CXCL9 and CXCL10 when HAM/TSP and HTLV-1 carriers were used as a combined group. However, despite a large proportion of HTLV-1 carriers having high IFN-gamma levels, these chemokines were not increased in carriers. This study showed that high levels of CXCL9 and CXCL10 in the systemic circulation and low serum CCL2 levels are features of HAM/TSP. HTLV-1 infection and Tax and/or additional viral encoded factor-mediated pathological processes triggering T cell activation with autogenous IFN-gamma release are probably involved in regulating chemokine release.

Biomarkers↗
PubMed2006

Serum and cerebral spinal fluid levels of chemokines and Th2 cytokines in Schistosoma mansoni myeloradiculopathy.

Schistosomal myeloradiculopathy (SMR) is the most common neurological form of Schistosoma mansoni infection. In this study we investigated the expression of chemokines and Th2 cytokines in serum and cerebral spinal fluid (CSF) of SMR patients. SMR patients presented increased serum levels of CCL11/eotaxin and CCL24/eotaxin-2 when compared to controls. SMR patients also had higher levels of IL-13 in CSF. Thus, SMR patients present enhancement of both IL-13 and CCR3 acting chemokines, both of which may facilitate the expression of a Th2 response and Th2-dependent damage to the spinal cord. As this cytokine is responsible for promoting Th2 responses, this finding is in accordance to the view that Th2 cells are important in the immunological process against the S. mansoni.

Adolescent↗
PubMed2006

Effect of the treatment with methylprednisolone on the cerebrospinal fluid and serum levels of CCL2 and CXCL10 chemokines in patients with active multiple sclerosis.

BACKGROUND: Several experimental and human studies suggest that the chemokines CCL2 and CXCL10 may play a role in the pathogenesis of multiple sclerosis (MS). Here, we evaluated the effect of intravenous methylprednisolone (IVMP) therapy on the levels of CCL2 and CXCL10 in the cerebrospinal fluid (CSF) and serum of patients with active MS. METHODS: Serum and CSF samples were obtained from 14 patients with active relapsing-remitting MS (age +/- SD years, 37.0 +/- 8.1; M/F, 6/8) and age- and gender-matched control subjects. All patients were submitted to IVMP treatment (500 mg daily for 5 days). Blood and CSF sampling were performed at admission, i.e. before treatment (day 0), at the end of the treatment (day 6) and 30 days after treatment (day 30). The clinical status of MS patients was also assessed. CCL2 and CXCL10 were measured by enzyme-linked immunosorbent assay. RESULTS: Multiple sclerosis patients had lower CCL2 and higher CXCL10 in CSF when compared with control subjetcs. After treatment with methylprednisolone, MS patients showed clinical improvement and the CSF concentrations of CCL2 and CXCL10 modified toward normal values. CONCLUSIONS: The clinical improvement of active MS following the treatment with methylprednisolone was associated with the modification of CSF levels of CCL2 and CXCL10, suggesting that these chemokines may be useful markers of response to treatment and relapses in MS patients.

Adult↗
PubMed2005

Migraine headache in patients with Sydenham's chorea.

We compared the frequency of migraine among Sydenham's chorea (SC) patients, rheumatic fever (RF) patients without neurological symptoms and matched controls. Migraine was more frequent in SC patients (12/55, 21.8%) than in controls (9/110, 8.1%) and as common as in the RF group (10/55, 18.2%). Our data are in agreement with previous studies reporting higher frequency of migraine in other basal ganglia disorders, such as essential tremor and Tourette's syndrome.

Adolescent↗
PubMed2002

Simple phonic tic in multiple sclerosis.

Movement disorders occurring in association with multiple sclerosis (MS) are rare. Among them paroxysmal dystonia is the most common, although chorea, ballism, palatal myoclonia, spasmodic torticollis, writer's cramp and generalized dystonia have been reported. We describe a 34-year old woman with MS who developed simple phonic tic characterized by throat-clearing sounds. Magnetic resonance imaging showed demyelinating lesions involving the thalamus and basal ganglia. This is the first report of tic disorder occurring as a manifestation of MS.

Adult↗
PubMed2001

Cardiac autonomic denervation and functional response to neurotoxins during acute experimental Chagas' disease in rats.

Severe cardiac autonomic denervation occurs in the acute Chagas' disease in rats. The present study aims at verifying whether this denervation was accompanied by impairment of heart function. Scorpionic (Tityus serrulatus) crude venom was used for neurotransmitter release in isolated hearts (Langendorff's preparation). In control hearts, the venom induced significant bradycardia followed by tachycardia. In infected animals, despite the severe (sympathetic) or moderate (parasympathetic) cardiac denervation, the venom provoked similar bradycardia but the tachycardia was higher. The hearts of infected animals beat at significantly lower rate. Atropine prevented this lower rate. Our results demonstrated sympathetic dysfunction during the acute phase of Trypanosoma cruzi infection in rats, the parasympathetic function being spared.

Acetylcholine↗
PubMed2001

Evidence for a direct action of Tityus serrulatus scorpion venom on the cardiac muscle.

The ability of toxins to activate the cardiovascular system plays an important role in the morbidity and lethality of the Tityus serrulatus scorpion envenoming. Most of the actions of the scorpion toxins are indirect and due to the release of adrenergic and cholinergic neurotransmitters. Accordingly, treatment following envenoming is targeted towards inhibition of adrenergic and cholinergic receptors. Here, we have sought evidence for a direct action of T. serrulatus venom on the isolated rat heart (Langendorff's method). We show that the bradycardia induced by T. serrulatus venom was completely blocked by atropine, a muscarinic receptor antagonist. Similarly, the increase in heart rate that follows the venom-induced bradycardia was totally inhibited by a beta(1)-adrenoceptor antagonist or by chemical sympathetic denervation with 6-hydroxydopamine. In contrast to these findings, the venom-induced increase in contractile force was not modified by beta(1)-adrenoceptor blockade or by chemical sympathetic denervation. The results clearly demonstrate that the chronotropic effects of T. serrulatus are dependent on neurotransmitter release, but the inotropic effects are not. The neurotransmitter-independent increase in contractility seems to be a direct action of the venom on cardiomyocytes. We suggest that this direct effect on cardiac fibers may play a role in the development of cardiac arrhythmias and contractility defects following envenoming with T. serrulatus scorpion.

Acetylcholine↗
PubMed2000

Infection with different Trypanosoma cruzi populations in rats: myocarditis, cardiac sympathetic denervation, and involvement of digestive organs.

We tested four isolates of Trypanosoma cruzi to assess parasite virulence and ability to cause myocarditis, cardiac sympathetic denervation, and histopathologic alterations in organs of the digestive system. The susceptibility of rats depends on the population of T. cruzi, with the ABC strain and the CL-Brener clone killing all animals, regardless of the parasitemic pattern. All tested T. cruzi populations caused acute myocarditis, but failed to induce histologic alterations in the intestine. The Cl-Brener and ABC isolates caused esophageal myositis. The myocarditis caused by the ABC, CL-Brener, and Y isolates was severe, but resolution started at the end of the acute phase. In contrast, the Col 1.7 G2 clone induced mild and sustained myocarditis. Our results also showed that T. cruzi populations able to induce severe acute myocarditis caused marked sympathetic denervation, but recovery of normal cardiac histology and innervation occurred. The sustained myocarditis induced by Col 1.7 G2 clone failed to cause sustained denervation.

Animals↗
PubMed1993

Strongyloidiasis in Campinas city region (Brazil). Parasitological and serological data.

A retrospective study of laboratory records in a 400-bed university hospital in Campinas city, SP (Southeastern Brazil) suggests that infection by Strongyloides stercoralis is widespread in the region. A prevalence of 10.81% was found in 37,621 stool specimens examined in a two-year period. Parasite-specific IgG antibodies were measured by ELISA in sera from 90 patients with strongyloidiasis. The ELISA detected antibody in 76 (84.44%) patients, indicating that serodiagnostic tests may be helpful in screening patients for strongyloidiasis.

Animals↗
PubMedDate not supplied

[The evaluation of antigenic preparations of Strongyloides stercoralis for the immunodiagnosis of strongyloidiasis].

Aqueous-soluble (AS) antigens from larvae of Strongyloides stercoralis, extracted with phosphate-buffered saline, are traditionally used for serodiagnosis of strongyloidiasis. To identify sources of antigens for use in serodiagnosis, residual particulates from parasite larvae after aqueous extraction were solubilized with Tris-buffered 8M urea, yielding a urea-soluble (US) antigen fraction. Both AS and US antigens from S. stercoralis were evaluated by an enzyme-linked immunosorbent assay. No significative differences were observed between AS and US antigens from the parasite regarding specific antigenic activity and cross-reactivity. Immunoassays are highly dependent on the antigen for sensitivity and specificity. Crude extracts from S. stercoralis should be further studied, mainly in relation to antigenic fractions which could provide even more sensitive and specific results. Studies of fractionation of S. stercoralis must take into account the antigen yield of both the crude extract and fractions, since larvae of parasite are normally difficult to obtain. Considering this aspect, the results from this study are very useful, since the extraction with urea substantially increased the amounts of antigenic materials normally obtained with the classical aqueous extraction.

Animals↗
PubMedDate not supplied

[Neural tube defects. The 10-year experience of a central maternity hospital].

OBJECTIVES: 1) To determine trends in prevalence of neural tube defects and the impact of therapeutic abortion. 2) To review perinatal management of spina bifida. DESIGN: All spontaneous and therapeutic abortions, still births and live births affected by neural tube defects registered in Alfredo da Costa Maternity in Lisbon, from 1983 to 1992, were retrospectively analysed. RESULTS: Eighty-two cases with neural tube defects are reported and myelomeningocele and anencephaly++ were the most frequent ones. Total prevalence for all defects was 0.78:1000 births with a small upward trend during the last two years. Birth prevalence was 0.6:1000, with a clear downward trend, due to therapeutic abortion. Prenatal diagnosis improved significantly, from 9% of all defects detected in 1983-87 to 77.5% in 1988-92. Since 1989, all cases of anencephaly were detected before birth. Most cases of spina bifida were vaginally delivered, and elective cesarean section occurred in 4. Early closure of the defect was undertaken in 87.6% of the newborns with open spina bifida. CONCLUSION: While total prevalence of neural tube defects remained stable, with only a small upward trend, prenatal diagnosis and therapeutic abortion resulted in a 56.3% fall in birth prevalence. Optimal management of open spina bifida demands a multidisciplinary team with an individual program for each case.

Female↗