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Biomedical subjects

P A Reyes

Publications and source records attributed to P A Reyes.

At least 19 recordsLinked to original sources
PubMed2005

Trypanocidal drugs for late stage, symptomatic Chagas disease (Trypanosoma cruzi infection).

BACKGROUND: People with Chagas disease (American Trypanosomiasis) may develop progressive and potentially lethal heart conditions. Drugs to eliminate the causative parasite, Trypanosoma cruzi, currently in use have limited therapeutic value and are used in early stages of the disease. Extending the use of these drugs to treat symptomatic chronic parasitism with chronic Chagasic cardiopathy (CCC) and progressive dilated cardiomyopathy has been proposed. OBJECTIVES: To assess the effects (harms and benefits) of nitrofurans and imidazolic trypanocidal drugs for treating late stage chronic Chagas disease and CCC. SEARCH STRATEGY: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) on The Cochrane Library (Issue 3, 2004), MEDLINE (1985-2004), EMBASE (1985-2004), BIREME (1985-2004), LILACS (1985-2004), ARTEMISA (1985-2004), SCIELO (1985-2004). Indexing terms in English and Spanish were used. References obtained were assessed for relevance by two reviewers independently. SELECTION CRITERIA: We included randomized controlled clinical trials (RCTs), single or double blind using trypanocidal drugs versus placebo or no treatment in CCC. DATA COLLECTION AND ANALYSIS: All articles retrieved were assessed using a predefined check list to determine if they met the inclusion criteria. Two independent reviewers collected data using a pre-designed form piloted on three articles before the review process started. Disagreements were resolved by a third reviewer. If the information was unavailable the articles were excluded. We planned a quantitative analysis of reduction of parasite load whether recorded as a categorical variable or the reduction of specific antibody titers. However insufficient data were available for quantitative analysis. We prepared a qualitative description of data identified. MAIN RESULTS: We found only one randomized double blind placebo controlled trial. We also found six uncontrolled or non-randomized studies which were of some relevance and were therefore described. We found insufficient evidence to define the effects of drug treatment for people with CCC. AUTHORS' CONCLUSIONS: There is insufficient evidence to support the efficacy of nitrofurans or imidazolic drugs as recommended treatment in CCC and chronic T.cruzi infections, specifically if overt heart disease is present. A well designed randomized controlled trial is necessary to establish if new drugs are suitable for treatment of cardiac patients with CCC.

Chagas Cardiomyopathy↗
PubMed2001

Anticardiolipin antibodies are not associated with rheumatic heart disease.

The aim of this study was to examine the prevalence of anticardiolipin antibodies in rheumatic valve heart disease. Serum samples of 31 consecutive patients with rheumatic heart disease and documented valve involvement, as well as six patients with acute rheumatic fever were tested for IgG anticardiolipin antibodies by a validated ELISA. No anticardiolipin antibodies were found when a cut-off point set at mean +/- 5 s.d. was applied. We can conclude that anticardiolipin antibodies are not present in rheumatic heart disease patients and, as suggested by several observations, these antibodies do not appear to have a pathogenic role in this particular disease.

Adult↗
PubMed2000

Absence of antiphospholipid/co-factor antibodies in Takayasu arteritis.

UNLABELLED: There are anecdotal reports and small series describing the presence of anticardiolipin antibodies in patients with Takayasu Arteritis. This communication describes a systematic study searching for non-organ specific autoantibodies which includes antinuclear antibodies, anticardiolipin and anti-beta(2) GP(1) antibodies in a cohort of 28 Mexicans with angiographic definitive diagnostic of Takayasu Arteritis. MATERIAL AND METHODS: Twenty-eight consecutive patients, who fulfilled classification and diagnostic criteria for Takayasu Arteritis and had a diagnostic panaortogram, were bled to study the presence of circulating autoantibodies in a cross-sectional design. RESULTS: There were no antinuclear antibodies, although a few sera had faint cytoplasm fluorescent deposit and reacted with cell extract. We did not recognize a distinct pattern. Also, there was no IgG nor IgM anticardiolipin antibodies nor anticofactor antibodies of clinical interest. DISCUSSION AND CONCLUSIONS: The presence of circulating non-organ specific autoantibodies is not a characteristic feature in Takayasu Arteritis when strict diagnostic criteria are applied. The occasional presence of such immune markers could be due to technical differences in sample management, less strict diagnosis or biological variability in certain cases, but has no diagnostic value.

Antibodies, Anti-Idiotypic↗
PubMed1998

Antiaorta antibodies and Takayasu arteritis.

A search for antibodies reactive against a total human aorta extract and its main protein components such as elastin, fibronectin and collagen was attempted by electroimmunetransference and ELISA. Thirty five sera from clinically and angiographically proven diagnosis of Takayasu Arteritis patients were compared with 32 sera from people without abnormalities. Non specific binding was found on electroimmune transference and no difference was shown in optical density readings in ELISA, therefore, we did not demonstrate the presence of antiaorta specific antibodies in this vasculitic condition. Our findings are in agreement with several authors, the contribution of humoral immunity to pathogenesis of Takayasu Arteritis has not been proved yet.

Adult↗
PubMed1998

Humoral nitric oxide levels and antibody immune response of symptomatic and indeterminate Chagas' disease patients to commercial and autochthonous Trypanosoma cruzi antigen.

We report here the evaluation of chagasic patients for the presence and/or severity of the disease, antibody to Trypanosoma cruzi, and nitric oxide (NO) serum levels. Serum samples tested by ELISA with autochthonous and commercial antigen revealed that 10% and 7.5% of the individuals were anti-T. cruzi antibody-positive, respectively. Ten of 21 seropositive individuals had no clinical signs, the other 11 cases presented cardiomyopathy and/or mega-gastrointestinal syndromes, and three patients presented a combined form. A statistical difference (P < 0.001) in antibody titer between asymptomatic and symptomatic patients with autochthonous antigen was detected, and serum NO levels was found to be three times higher in cases than in controls. These results suggest that it is recommended to use a sole source of antigen (autochthonous) for the serodiagnosis of Chagas' disease, and that the pathogenic role of NO in this disease should be evaluated.

Adult↗
PubMed1997

Absence of ANCA in Mexican patients with Takayasu's arteritis.

Antineutrophil cytoplasmic autoantibodies (ANCA) were sought in 43 sera from 39 Mexican patients with typical Takayasu's arteritis (TA), (5 with active and 34 with inactive disease), and in a comparative group comprising 50 sera. Results were negative in all cases. This suggests that ANCA are not a serologic feature in TA per se, even during its active stage. ANCA positivity in TA, when present, may be a non-related phenomenon and probably identifies a subset of patients with atypical forms of TA or a polyangiitis overlap syndrome.

Adult↗
PubMed1997

Molecular analysis of snRNAs and scRNAs using autoantibodies from patients with systemic lupus erythematosus.

Immunoprecipitation analysis of total HeLa cells RNA extract by protein A-Sheparose purified autoantibodies and pCp 32P-3' end labeling RNAs revealed that U1, U2, U4 and U5 snRNAs are related with anti-Sm or U1nRNP autoantibodies, while the hY1, hY3, hY4 and hY5 scRNAs were related to anti-SSA/Ro autoantibodies present in sera of patients with Systemic Lupus Erythematosus. The authors detected molecular snRNAs and scRNAs specificities by autoantibodies in 71 sera, the molecular RNA specificity for anti-Sm (U1, U2, U4 and U5 snRNAs) was present in 39%; anti-SSA/Ro sera reacted against scRNAs (hY1, hY3, hY4 and hY5) in 36%, then anti-U1nRNP sera recognized U1 snRNA in 13% of sera and anti-rRNP related with rRNA were recognized in 8%. Twenty-nine SLE sera were RNA negative. A molecular characterization of the autoantibodies in sera from SLE patients may be a useful tool for clinical and laboratory diagnosis of SLE, and the use of autoantibodies as molecular probes allows to continue exploring some basic mechanism of gene expression.

Autoantibodies↗
PubMed1996

Organ-specific circulating heart autoantibodies in Chagas' cardiomyopathy: exploratory study.

Chagas' disease can evolve to a chronic phase with cardiomyopathy that may include autoimmune mechanisms, among others. Recently an organ-specific anti-heart muscle antibody was detected in idiopathic cardiomyopathy, using human heart muscle as antigen. We decide to standardize an indirect immunofluorescence assay using rat organs in order to evaluate frequency of organ-specific anti-heart antibodies in chagasic cardiomyopathy. We tested 18 patients with chagasic cardiomyopathy for serum organ-specific anti-heart muscle antibodies. Nine patients were positive for organ-specific anti-heart antibodies (positive in heart muscle but negative in tongue muscle) and one was positive for non-organ-specific anti-heart muscle antibodies (positive in both heart and tongue muscle). We conclude that organ-specific anti-heart muscle antibodies can be detected using rat organs as antigens. Organ-specific anti-heart muscle antibodies are present in patients with chagasic cardiomyopathy.

Adult↗
PubMed1996

American trypanosomosis: in situ and generalized features of parasitism and inflammation kinetics in a murine model.

American trypanosomiasis: In situ and generalized features of parasitism and inflammation kinetics in a murine model. Experimental Parasitology 83, 267-274. Mimicking the natural conditions of mammalian infection, metacyclic trypomastigote forms of a Mexican isolate (Ninoa) of Trypanosoma cruzi were inoculated into mice in order to study inflammation kinetics and parasite clearance at the inoculation site, parasite tropism to different organs, and local inflammatory cell infiltrates. Polymorphonuclear cells were detected at the inoculation site as early as 1 hr after inoculation. Peak cell infiltrate was observed at 24 hr; at 96 hr polymorphonuclear cells had disappeared. Mononuclear cell infiltrates began at 24 hr, peaking at Day 15, and then stared disappearing by Day 30. Antigens and parasites were detected by conventional techniques up to 15 min and thereafter became undetectable. Amplification of the hypervariable region of kinetoplast minicircle DNA by polymerase chain reaction was positive from 24 hr to Day 15, and the reaction became negative on Day 30. Myositis was observed in skeletal muscle from Days 7 to 180, it progressed from slight to severe, with an inflammation process which included macrophages, plasmatic cells, and a few eosinophils, the phenotype of the infiltrating cells included LyT2+ and LyT1+ on Day 30, and both cell populations decreased in parallel on Day 180. Antigen and parasite nests were present from Day 15 to 180; in muscle the earliest time at which minicircle DNA was detected was Day 7 and it was present until Day 180. Myocarditis was also observed; it developed from slight to severe in between Days 7 and 30, then gradually decreased, and cleared up. Mononuclear cell infiltrates in the myocardium were present from Days 7 to 180. Antigen and parasite nests were detected at Days 15 and 30 and disappeared at Day 180, although minicircle DNA was detected until the last day of observation. Both skeletal and heart muscles showed inflammatory reaction foci containing T. cruzi antigen. There was twice the number of foci in heart as in skeletal muscle. This ratio was maintained by Day 30; later skeletal muscle showed persistent inflammation which was practically cleared up in the heart. Parasites or antigen were not detected by Day 180 in both skeletal and cardiac muscle; however, minicircle DNA was amplified, indicating that an small proportion of parasites evaded immune response. According to these data, Mexican Ninoa Strain has a classification as biodeme 3.

Amino Acid Sequence↗
PubMed1996

Takayasu arteritis in Mexico: a 38-year clinical perspective through literature review.

A literature search covering national reports since the first published in Mexico (1957), discloses 237 adults and 55 children with a definitive diagnosis of Takayasu's arteritis. This condition was first recognized by an ophtalmologist in 1946, and it was communicated 10 years after his observation. Since 1957, 11 clinical papers on Takayasu's arteritis had been published in Mexico and abroad; in contrast few papers were published in other Latinamerican countries and even in North America. Takayasu's arteritis in Mexico follows the clinical pattern described in Asian reports, it affects mainly non-caucasic young women, is a chronic disease which causes prominent cardiovascular complaints. Children developed a systemic disease with higher morbility and mortality. Uncommon diseases, such as Takayasu's arteritis represent an unique opportunity to compare clinical and biological profile among different populations to gain valuable knowledge and understanding of ethiopathogenesis.

Adolescent↗
PubMed1996

Valvular heart disease in primary antiphospholipid syndrome (PAPS): clinical and morphological findings.

PURPOSE: To describe clinically and pathologically the valvular lesion of the primary antiphospholipid syndrome (PAPS). PATIENTS AND METHODS: We studied six patients with PAPS and valvulopathy. Four of them died and had autopsy and two had valvular replacement. The study comprised 18 heart valves, 16 from autopsy and two, one mitral and one aortic, resected at surgery. RESULTS: Murmurs and echocardiographic findings kept correlation with gross pathology. Abnormalities were found in one or more valves in all patients including two of five aortic, two of five mitral, one of four pulmonary and two of four tricuspid. Co-existence of new and old lesions was observed. Pathologic findings included intravalvular thrombosis with focal necrosis, and hemorrhage, vascular proliferation, mild histiocytic/fibroblastic infiltration, laminated and verrucous fibrin deposits, laminated and/or nodular fibrosis, and focal calcification. CONCLUSION: The PAPS valvular lesion consists mainly of superficial or intravalvular fibrin deposits and its subsequent organization: vascular proliferation, fibroblast influx, fibrosis and calcification. This results in valve thickening, fusion and rigidity leading to functional abnormalities. Inflammation is not a prominent feature of this lesion.

Adult↗
PubMed1996

Primary antiphospholipid syndrome presenting as chronic thromboembolic pulmonary hypertension. Treatment with thromboendarterectomy.

Pulmonary hypertension may occur in the antiphospholipid syndrome as a result of recurrent pulmonary embolism or microthrombosis of pulmonary vessels. We describe 3 cases of primary antiphospholipid syndrome (APS) and cor pulmonale that fulfilled the criteria for chronic major vessel thromboembolic pulmonary hypertension. Pulmonary thromboendarterectomy was performed in all 3 patients and it was successful in 2. One patient died in the immediate postoperative period from hemorrhagic pulmonary edema. Chronic thromboembolic pulmonary hypertension should be added to the list of pulmonary vascular complications of primary APS. Despite its risk, pulmonary thromboendarterectomy represents a treatment option for this otherwise lethal condition.

Adult↗
PubMed1995

Ocular vaso-occlusive disease in primary antiphospholipid syndrome.

PURPOSE: To evaluate the ocular involvement in patients with the primary antiphospholipid syndrome. METHODS: The authors performed a cross-sectional ophthalmologic study of 17 patients with the primary antiphospholipid syndrome. Retinal fluorangiography was performed in 13 patients. RESULTS: Visual symptoms were described by ten patients. Visual acuity was markedly decreased in five eyes. Conjunctival telangiectases and microaneurysms, in addition to single instances of bilateral episcleritis and limbal keratitis, were the anterior segment findings. Fundus abnormalities were present in 15 patients. Venous tortuosity was the most common finding but there were instances of optic disc edema, vitreous hemorrhages, cotton-wool spots, vitreous bands, serous detachment of the macula, and retinal capillary abnormalities. Fluorangiography showed vaso-occlusive retinopathy in six eyes (5 patients, 29%). Choriocapillary vessel occlusion was observed in two eyes (1 patient) and binocular reticular degeneration of pigmentary epithelium was present in another case. CONCLUSION: The eye is frequently involved in the primary antiphospholipid syndrome, and serious ocular damage may occur. Detailed ophthalmologic evaluation is warranted in these patients.

Adult↗