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1.
BMC Microbiol ; 9: 194, 2009 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-19744321

RESUMEN

BACKGROUND: Chamydophila pneumoniae (CP) and/or Mycoplasma pneumoniae (MP) are two bacteria detected in vulnerable atheromas. In this study we aimed to analyze whether CP and/or MP aggravates atherosclerosis induced by cholesterol-enriched diet in C57BL/6 apoE KO male mice. Thirty male apoE KO mice aged eight weeks fed by a diet containing 1% cholesterol until 32 weeks of age were divided into four groups: the first was inoculated with CP (n = 7), the second with MP (n = 12), the third with both CP + MP (n = 5), and the fourth with saline (sham n = 6). The animals were re-inoculated at 36 weeks of age, and sacrificed at 40 weeks of age. Two ascending aorta and one aortic arch segments were sampled. In the most severely obstructed segment, vessel diameter, plaque height, percentage of luminal obstruction and the degree of adventitial inflammation were analyzed. The plaque area/intimal surface ratio was obtained by measuring all three segments. The adventitial inflammation was semiquantified (0 absent, 1 mild, 2 moderate, and 3 diffuse). RESULTS: The mean and standard deviation of plaque height, % luminal obstruction, external diameter, the plaque area/intimal surface ratio and the adventitial inflammation values are the following for each group: MP (0.20 +/- 0.12 mm, 69 +/- 26%, 0.38 +/- 0.11 mm, 0.04 +/- 0.04 and 0.22 +/- 0.67), CP (0.23 +/- 0.08 mm, 90 +/- 26%, 0.37 +/- 0.08 mm, 0.04 +/- 0.03, and 0.44 +/- 0.53), MP + CP (18 +/- 0.08 mm, 84 +/- 4.0%, 0.35 +/- 0.25 mm, 0.03 +/- 0.03 and 1.33 +/- 0.82) and sham (0.08 +/- 0.09 mm, 42 +/- 46%, 0.30 +/- 0.10 mm, 0.02 +/- 0.03 and 0.71 +/- 0.76). A wider area of plaque/intimal surface was observed in MP + CP inoculated groups (p = 0.07 and 0.06) as well as an increased plaque height in CP (p = 0.01) in comparison with sham group. There was also an increased luminal obstruction (p = 0.047) in CP inoculated group in comparison to sham group. Adventitial inflammation in MP + CP inoculated group was higher than MP, CP and the sham groups (p = 0.02). CONCLUSION: Inoculation of CP, MP or both agents in C57BL/6 apoE KO male mice caused aggravation of experimental atherosclerosis induced by cholesterol-enriched diet, with distinct characteristics. CP inoculation increased the plaque height with positive vessel remodeling and co-inoculation of MP + CP caused the highest adventitial inflammation measures.


Asunto(s)
Aterosclerosis/complicaciones , Infecciones por Chlamydophila/complicaciones , Neumonía por Mycoplasma/complicaciones , Animales , Aorta/microbiología , Aorta/patología , Enfermedades de la Aorta/complicaciones , Enfermedades de la Aorta/microbiología , Aterosclerosis/microbiología , Chlamydophila pneumoniae , Colesterol en la Dieta , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Mycoplasma pneumoniae
2.
Mem Inst Oswaldo Cruz ; 104 Suppl 1: 199-207, 2009 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-19753475

RESUMEN

UNLABELLED: Chronic cardiopathy (CC) in Chagas disease is a fibrotic myocarditis with C5b-9 complement deposition. Mycoplasma and Chlamydia may interfere with the complement response. Proteolytic enzymes and archaeal genes that have been described in Trypanosoma cruzi may increase its virulence. Here we tested the hypothesis that different ratios of Mycoplasma, Chlamydia and archaeal organisms, which are frequent symbionts, may be associated with chagasic clinical forms. MATERIALS AND METHODS: eight indeterminate form (IF) and 20 CC chagasic endomyocardial biopsies were submitted to in situ hybridization, electron and immunoelectron microscopy and PCR techniques for detection of Mycoplasma pneumoniae (MP), Chlamydia pneumoniae(CP), C5b-9 and archaeal-like bodies. RESULTS: MP and CP-DNA were always present at lower levels in CC than in IF (p < 0.001) and were correlated with each other only in CC. Electron microscopy revealed Mycoplasma, Chlamydia and two types of archaeal-like bodies. One had electron dense lipid content (EDL) and was mainly present in IF. The other had electron lucent content (ELC) and was mainly present in CC. In this group, ELC correlated negatively with the other microbes and EDL and positively with C5b-9. The CC group was positive for Archaea and T. cruzi DNA. In conclusion, different amounts of Mycoplasma, Chlamydia and archaeal organisms may be implicated in complement activation and may have a role in Chagas disease outcome.


Asunto(s)
Archaea/aislamiento & purificación , Cardiomiopatía Chagásica/microbiología , Chlamydophila pneumoniae/aislamiento & purificación , Complejo de Ataque a Membrana del Sistema Complemento/análisis , Mycoplasma pneumoniae/aislamiento & purificación , Antígenos Bacterianos/análisis , Biopsia , Cardiomiopatía Chagásica/patología , Enfermedad Crónica , Humanos , Hibridación in Situ , Microscopía Electrónica , Reacción en Cadena de la Polimerasa
3.
Artículo en Inglés | MEDLINE | ID: mdl-30519544

RESUMEN

Background: Archaeal genes present in Trypanosoma cruzi may represent symbionts that would explain development of heart failure in 30% of Chagas disease patients. Extracellular vesicles in peripheral blood, called exosomes (< 0.1 µm) or microvesicles (>0.1 µm), present in larger numbers in heart failure, were analyzed to determine whether they are derived from archaea in heart failure Chagas disease. Methods: Exosomes and microvesicles in serum supernatant from 3 groups were analyzed: heart failure Chagas disease (N = 26), asymptomatic indeterminate form (N = 21) and healthy non-chagasic control (N = 16). Samples were quantified with transmission electron microscopy, flow cytometer immunolabeled with anti-archaemetzincin-1 antibody (AMZ 1, archaea collagenase) and probe anti-archaeal DNA and zymography to determine AMZ1 (Archaeal metalloproteinase) activity. Results: Indeterminate form patients had higher median numbers of exosomes/case vs. heart failure patients (58.5 vs. 25.5, P < 0.001), higher exosome content of AMZ1 antigens (2.0 vs. 0.0; P < 0.001), and lower archaeal DNA content (0.2 vs. 1.5, P = 0.02). A positive correlation between exosomes and AMZ1 content was seen in indeterminate form (r = 0.5, P < 0.001), but not in heart failure patients (r = 0.002, P = 0.98). Higher free archaeal DNA (63.0 vs. 11.1, P < 0.001) in correlation with exosome numbers (r = 0.66, P = 0.01) was seen in heart failure but not in indeterminate form (r = 0.29, P = 0.10). Flow cytometer showed higher numbers of AMZ1 microvesicles in indeterminate form (64 vs. 36, P = 0.02) and higher archaeal DNA microvesicles in heart failure (8.1 vs. 0.9, P < 0.001). Zymography showed strong% collagenase activity in HF group, mild activity in IF compared to non-chagasic healthy group (121 ± 14, 106 ± 13 and 100; P < 0.001). Conclusions: Numerous exosomes, possibly removing and degrading abnormal AMZ1 collagenase, are associated with indeterminate form. Archaeal microvesicles and their exosomes, possibly associated with release of archaeal AMZ1 in heart failure, are future candidates of heart failure biomarkers if confirmed in larger series, and the therapeutic focus in the treatment of Chagas disease.


Asunto(s)
Archaea/fisiología , Enfermedad de Chagas/inmunología , Insuficiencia Cardíaca/inmunología , Trypanosoma cruzi/inmunología , Trypanosoma cruzi/microbiología , Adulto , Anciano , Anciano de 80 o más Años , Antígenos Bacterianos/sangre , Biomarcadores , Enfermedad de Chagas/sangre , Colagenasas , Exosomas , Femenino , Citometría de Flujo , Insuficiencia Cardíaca/sangre , Humanos , Masculino , Metaloproteasas , Microscopía Electrónica de Transmisión , Persona de Mediana Edad
4.
Biomed Res Int ; 2017: 7212985, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28337456

RESUMEN

Previous studies showed the presence of Mycoplasma pneumoniae (M. pneumoniae) and membrane-shed microparticles (MPs) in vulnerable atherosclerotic plaques. H&S Science and Biotechnology developed PTCTS, composed by natural particles from medicinal plants (PTC) combined with trans-Sialidase (TS), to combat MPs and Mycoplasma pneumoniae. Our aim was to determine the effects of the different components of PTCTS in a rabbit model of atherosclerosis. Rabbits were fed with high cholesterol diet for 12 weeks and treated during the last 6 weeks with either vehicle, PTC, TS, or PTCTS. Lipid profile and quantification of MPs positive for Mycoplasma pneumoniae and oxidized LDL antigens were carried out. Aortas and organs were then histologically analyzed. PTCTS reduced circulating MPs positive for Mycoplasma pneumoniae and oxidized LDL antigens, reduced the plaque area in the abdominal aorta, and caused positive remodeling of the ascendant aorta. PTC caused positive remodeling and reduced plaque area in the abdominal aorta; however, TS had a lipid lowering effect. PTCTS components combined were more effective against atherosclerosis than individual components. Our data reinforce the infectious theory of atherosclerosis and underscore the potential role of circulating MPs. Therefore, the removal of Mycoplasma-derived MPs could be a new therapeutic approach in the treatment of atherosclerosis.


Asunto(s)
Aterosclerosis/tratamiento farmacológico , Glicoproteínas/administración & dosificación , Mycoplasma pneumoniae/efectos de los fármacos , Neuraminidasa/administración & dosificación , Placa Aterosclerótica/tratamiento farmacológico , Animales , Aorta Abdominal/efectos de los fármacos , Aorta Abdominal/patología , Aterosclerosis/metabolismo , Aterosclerosis/microbiología , Aterosclerosis/patología , Productos Biológicos/administración & dosificación , Productos Biológicos/química , Colesterol en la Dieta/farmacología , Dieta Alta en Grasa/efectos adversos , Modelos Animales de Enfermedad , Glicoproteínas/química , Humanos , Lipoproteínas LDL/metabolismo , Masculino , Mycoplasma pneumoniae/patogenicidad , Neuraminidasa/química , Plantas Medicinales/química , Placa Aterosclerótica/microbiología , Placa Aterosclerótica/patología , Conejos
5.
APMIS ; 114(5): 338-44, 2006 May.
Artículo en Inglés | MEDLINE | ID: mdl-16725009

RESUMEN

Mycoplasma pneumoniae (MP) and Chlamydophila pneumoniae (CP) antigens are encountered in complicated atheromas and may be implicated in the diversity of atherosclerotic lesions. Mycoplasma can downregulate the immune system, altering levels of inflammation, which may favor the proliferation of other co-infectious agents. In the present study we analyze whether initially stable human atheromas exhibit different ratios of MP/CP antigens compared to ongoing atheromatous lesions. Two groups were examined for the presence of inflammatory cells, macrophages, growth factors and infectious agents: Group I (GI), n=16, early stable atheromas, <4 CD68(+) macrophages/400 x field, showing a normal distribution and a fibrous cap; Group II (GII), n=14, growing atheromas, > or =4 CD68+ cells/400 x field, lacking a fibrous cap, showing a non-normal macrophage distribution. The amounts of CP (but not MP) antigens and lymphocytes in GI were significantly lower than in GII. MP/CP ratios were higher in GI. MP correlated with CP and PDGFB in GI (r=0.79 and r=0.83, p<0.001), but not in GII (r=-0.4 and r=-0.08, p=0.81). MP and CP antigens are already present in early atheromas, and a higher MP/CP ratio correlates with increased growth factors, lower inflammation and plaque stability.


Asunto(s)
Infecciones por Chlamydophila/complicaciones , Chlamydophila pneumoniae/aislamiento & purificación , Enfermedad de la Arteria Coronaria/diagnóstico , Enfermedad de la Arteria Coronaria/microbiología , Mycoplasma pneumoniae/aislamiento & purificación , Neumonía por Mycoplasma/complicaciones , Adulto , Anciano , Anciano de 80 o más Años , Antígenos Bacterianos/análisis , Antígenos CD/metabolismo , Antígenos de Diferenciación Mielomonocítica/metabolismo , Recuento de Células , Chlamydophila pneumoniae/inmunología , Enfermedad de la Arteria Coronaria/patología , Vasos Coronarios/microbiología , Vasos Coronarios/patología , Progresión de la Enfermedad , Femenino , Humanos , Inmunohistoquímica , Inflamación/patología , Macrófagos/citología , Macrófagos/patología , Masculino , Persona de Mediana Edad , Mycoplasma pneumoniae/inmunología , Factor de Crecimiento Derivado de Plaquetas/metabolismo
6.
Clinics (Sao Paulo) ; 71(3): 163-8, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-27074178

RESUMEN

OBJECTIVE: Exercise is a protective factor for cardiovascular morbidity and mortality, with unclear mechanisms. Changing the myocardial metabolism causes harmful consequences for heart function and exercise contributes to metabolic adjustment modulation. Peroxisome proliferator-activated receptors (PPARs) are also myocardium metabolism regulators capable of decreasing the inflammatory response. We hypothesized that PPAR-α is involved in the beneficial effects of previous exercise on myocardial infarction (MI) and cardiac function, changing the expression of metabolic and inflammatory response regulators and reducing myocardial apoptosis, which partially explains the better outcome. METHODS AND RESULTS: Exercised rats engaged in swimming sessions for 60 min/day, 5 days/week, for 8 weeks. Both the exercised rats and sedentary rats were randomized to MI surgery and followed for 1 week (EI1 or SI1) or 4 weeks (EI4 or SI4) of healing or to sham groups. Echocardiography was employed to detect left ventricular function and the infarct size. Additionally, the TUNEL technique was used to assess apoptosis and immunohistochemistry was used to quantitatively analyze the PPAR-α, TNF-α and NF-κB antigens in the infarcted and non-infarcted myocardium. MI-related mortality was higher in SI4 than in EI4 (25% vs 12%), without a difference in MI size. SI4 exhibited a lower shortening fraction than EI4 did (24% vs 35%) and a higher apoptosis/area rate (3.97±0.61 vs 1.90±1.82) in infarcted areas (both p=0.001). Immunohistochemistry also revealed higher TNF-α levels in SI1 than in EI1 (9.59 vs 4.09, p<0.001) in infarcted areas. In non-infarcted areas, EI4 showed higher levels of TNF-α and positive correlations between PPAR-α and NF-κB (r=0.75, p=0.02), in contrast to SI4 (r=0.05, p=0.87). CONCLUSION: Previously exercised animals had better long-term ventricular function post-MI, in addition to lower levels of local inflammatory markers and less myocardial apoptosis, which seemed to be related to the presence of PPAR-α.


Asunto(s)
Infarto del Miocardio/metabolismo , PPAR alfa/metabolismo , Condicionamiento Físico Animal/fisiología , Animales , Apoptosis/fisiología , Femenino , Inflamación/metabolismo , Modelos Animales , Infarto del Miocardio/diagnóstico por imagen , Infarto del Miocardio/patología , FN-kappa B/metabolismo , PPAR alfa/análisis , Distribución Aleatoria , Ratas Wistar , Tiempo , Factor de Necrosis Tumoral alfa/metabolismo , Ultrasonografía , Función Ventricular/fisiología
7.
Contemp Top Lab Anim Sci ; 42(1): 52-6, 2003 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-12580575

RESUMEN

Routine examinations of conventional outbred Wistar rats in our laboratory showed increased serum levels of alkaline phosphatase, aspartate aminotransferase, alanine aminotransferase, and urea. Electron microscopy and specific reactions showed C. pneumoniae and M. pulmonis in lung, liver, spleen, heart, and kidney sections. We could not exclude the fact that other infectious microorganisms detected through routine health surveillance affected the Wistar rat colony; however, we have not identified any of those microorganisms by electron microscopy of the organs listed. Natural coinfection of C. pneumoniae and M. pulmonis can occur in laboratory rats and is associated with histopathological and functional compromise of many organs. Further studies comparing different conventional animals and specific pathogen-free animals are necessary to better understand the present findings and to define whether coinfection influences the results of experimental studies with rats.


Asunto(s)
Animales de Laboratorio , Infecciones por Chlamydophila/veterinaria , Chlamydophila pneumoniae , Infecciones por Mycoplasma/veterinaria , Ratas Wistar , Enfermedades de los Roedores/microbiología , Alanina Transaminasa/sangre , Fosfatasa Alcalina/sangre , Animales , Animales de Laboratorio/microbiología , Aspartato Aminotransferasas/sangre , Infecciones por Chlamydophila/complicaciones , Chlamydophila pneumoniae/aislamiento & purificación , Corazón/microbiología , Riñón/microbiología , Hígado/microbiología , Pulmón/microbiología , Masculino , Microscopía Electrónica , Mycoplasma/aislamiento & purificación , Infecciones por Mycoplasma/complicaciones , Ratas , Ratas Wistar/microbiología , Enfermedades de los Roedores/sangre , Enfermedades de los Roedores/patología , Bazo/microbiología , Urea/sangre
8.
Clinics ; 71(3): 163-168, Mar. 2016. tab, graf
Artículo en Inglés | LILACS | ID: lil-778995

RESUMEN

OBJECTIVE: Exercise is a protective factor for cardiovascular morbidity and mortality, with unclear mechanisms. Changing the myocardial metabolism causes harmful consequences for heart function and exercise contributes to metabolic adjustment modulation. Peroxisome proliferator-activated receptors (PPARs) are also myocardium metabolism regulators capable of decreasing the inflammatory response. We hypothesized that PPAR-α is involved in the beneficial effects of previous exercise on myocardial infarction (MI) and cardiac function, changing the expression of metabolic and inflammatory response regulators and reducing myocardial apoptosis, which partially explains the better outcome. METHODS AND RESULTS: Exercised rats engaged in swimming sessions for 60 min/day, 5 days/week, for 8 weeks. Both the exercised rats and sedentary rats were randomized to MI surgery and followed for 1 week (EI1 or SI1) or 4 weeks (EI4 or SI4) of healing or to sham groups. Echocardiography was employed to detect left ventricular function and the infarct size. Additionally, the TUNEL technique was used to assess apoptosis and immunohistochemistry was used to quantitatively analyze the PPAR-α, TNF-α and NF-κB antigens in the infarcted and non-infarcted myocardium. MI-related mortality was higher in SI4 than in EI4 (25% vs 12%), without a difference in MI size. SI4 exhibited a lower shortening fraction than EI4 did (24% vs 35%) and a higher apoptosis/area rate (3.97±0.61 vs 1.90±1.82) in infarcted areas (both p=0.001). Immunohistochemistry also revealed higher TNF-α levels in SI1 than in EI1 (9.59 vs 4.09, p<0.001) in infarcted areas. In non-infarcted areas, EI4 showed higher levels of TNF-α and positive correlations between PPAR-α and NF-κB (r=0.75, p=0.02), in contrast to SI4 (r=0.05, p=0.87). CONCLUSION: Previously exercised animals had better long-term ventricular function post-MI, in addition to lower levels of local inflammatory markers and less myocardial apoptosis, which seemed to be related to the presence of PPAR-α.


Asunto(s)
Animales , Femenino , Infarto del Miocardio/metabolismo , PPAR alfa/metabolismo , Condicionamiento Físico Animal/fisiología , Apoptosis/fisiología , Inflamación/metabolismo , Modelos Animales , Infarto del Miocardio/patología , Infarto del Miocardio , FN-kappa B/metabolismo , PPAR alfa/análisis , Distribución Aleatoria , Ratas Wistar , Tiempo , Factor de Necrosis Tumoral alfa/metabolismo , Función Ventricular/fisiología
9.
Mem. Inst. Oswaldo Cruz ; 104(supl.1): 199-207, July 2009. ilus, tab
Artículo en Inglés | LILACS | ID: lil-520880

RESUMEN

Chronic cardiopathy (CC) in Chagas disease is a fibrotic myocarditis with C5b-9 complement deposition. Mycoplasma and Chlamydia may interfere with the complement response. Proteolytic enzymes and archaeal genes that have been described in Trypanosoma cruzi may increase its virulence. Here we tested the hypothesis that different ratios of Mycoplasma, Chlamydia and archaeal organisms, which are frequent symbionts, may be associated with chagasic clinical forms. MATERIALS AND METHODS: eight indeterminate form (IF) and 20 CC chagasic endomyocardial biopsies were submitted to in situ hybridization, electron and immunoelectron microscopy and PCR techniques for detection of Mycoplasma pneumoniae (MP), Chlamydia pneumoniae(CP), C5b-9 and archaeal-like bodies. RESULTS: MP and CP-DNA were always present at lower levels in CC than in IF (p < 0.001) and were correlated with each other only in CC. Electron microscopy revealed Mycoplasma, Chlamydia and two types of archaeal-like bodies. One had electron dense lipid content (EDL) and was mainly present in IF. The other had electron lucent content (ELC) and was mainly present in CC. In this group, ELC correlated negatively with the other microbes and EDL and positively with C5b-9. The CC group was positive for Archaea and T. cruzi DNA. In conclusion, different amounts of Mycoplasma, Chlamydia and archaeal organisms may be implicated in complement activation and may have a role in Chagas disease outcome.


Asunto(s)
Humanos , Archaea/aislamiento & purificación , Cardiomiopatía Chagásica/microbiología , Chlamydophila pneumoniae/aislamiento & purificación , Complejo de Ataque a Membrana del Sistema Complemento/análisis , Mycoplasma pneumoniae/aislamiento & purificación , Antígenos Bacterianos/análisis , Biopsia , Enfermedad Crónica , Cardiomiopatía Chagásica/patología , Hibridación in Situ , Microscopía Electrónica , Reacción en Cadena de la Polimerasa
10.
Arq. bras. cardiol ; 74(2): 149-51, Jan. 2000. ilus
Artículo en Inglés | LILACS | ID: lil-262348

RESUMEN

A possible relationship between C.pneumoniae (CP) infection, atherosclerosis and acute myocardial infarction is a debated matter. Now we performed the search of CP in histological segments of fatal ruptured plaques and of stable plaques by histochemistry (Macchiavello stain), immunohistochemistry and in situ hybridization techniques. Electron microscopy and confocal laser microscopy techniques were used in two additional cases. The semi-quantitification of CP + cells (0-4+) and quantification of lymphocytes demonstrated greater amount of CP + cells and more inflammation in the adventitia of vulnerable plaque vessel segments than of stable ones, larger amount of CP + cells in adventitia than in the plaque and high frequency of CP + cells in all groups studied. This preliminary study strongly suggests a direct pathogenetic involvement of adventitial CP in the rupture of the atheromatous plaque, development of acute myocardial infarction and also in the development of atherosclerosis.


Asunto(s)
Humanos , Aterosclerosis/microbiología , Infecciones por Chlamydia/complicaciones , Chlamydophila pneumoniae/aislamiento & purificación , Infarto del Miocardio/microbiología , Aterosclerosis/patología , Vasos Sanguíneos/microbiología , Vasos Sanguíneos/patología , Infarto del Miocardio/patología
11.
In. Schiabel, Homero; Slaets, Annie France Frère; Costa, Luciano da Fontoura; Baffa Filho, Oswaldo; Marques, Paulo Mazzoncini de Azevedo. Anais do III Fórum Nacional de Ciência e Tecnologia em Saúde. Säo Carlos, s.n, 1996. p.771-772.
Monografía en Portugués | LILACS | ID: lil-233974

RESUMEN

Este trabalho apresenta o desenvolvimento de um programa educativo em hipermidia, direcionado para jovens, que tem a finalidade de promover a reflexão sobre aspectos da AIDS. Utilizando-se da tecnologia da informática, com sons e imagens e com metáfora de história em quadrinhos, pretende-se estimular uma mudança de comportamento frente às questões de prevenção, aspectos sexuais, sociais e existenciais. O programa foi elaborado a partir da ferramenta de autoria "Multimedia Toolbook 3.0", com recursos e interfaces agradáveis e estimulantes para a população de adolescentes e pré-adolescentes. Nas imagens das diversas telas encontram-se questionamentos que facilitarão a cada usuário, a construção de respostas a partir da própria reflexão.


Asunto(s)
Humanos , Niño , Adolescente , Hipermedia , Metáfora , Síndrome de Inmunodeficiencia Adquirida/prevención & control , Síndrome de Inmunodeficiencia Adquirida/transmisión
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