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1.
Viruses ; 15(12)2023 Nov 23.
Artículo en Inglés | MEDLINE | ID: mdl-38140542

RESUMEN

Monkeypox virus (MPXV), belonging to the Poxviridae family and Orthopoxvirus genus, is closely related to the smallpox virus. Initial prodromal symptoms typically include headache, fever, and lymphadenopathy. This review aims to detail various ocular manifestations and immune evasion associated with the monkeypox viral infection and its complications, making it appropriate as a narrative review. Common external ocular manifestations of MPXV typically involve a generalized pustular rash, keratitis, discharges, and dried secretions related to conjunctival pustules, photophobia, and lacrimation. Orthopoxviruses can evade host immune responses by secreting proteins that antagonize the functions of host IFNγ, CC and CXC chemokines, IL-1ß, and the complement system. One of the most important transcription factors downstream of pattern recognition receptors binding is IRF3, which controls the expression of the crucial antiviral molecules IFNα and IFNß. We strongly recommend that ophthalmologists include MPXV as part of their differential diagnosis when they encounter similar cases presenting with ophthalmic manifestations such as conjunctivitis, blepharitis, or corneal lesions. Furthermore, because non-vaccinated individuals are more likely to exhibit these symptoms, it is recommended that healthcare administrators prioritize smallpox vaccination for at-risk groups, including very young children, pregnant women, older adults, and immunocompromised individuals, especially those in close contact with MPXV cases.


Asunto(s)
Enfermedades de la Córnea , Monkeypox virus , Niño , Humanos , Femenino , Embarazo , Preescolar , Anciano , Evasión Inmune , Vacunación , Párpados
2.
Viruses ; 15(2)2023 02 16.
Artículo en Inglés | MEDLINE | ID: mdl-36851765

RESUMEN

Non-human primates contribute to the spread of yellow fever virus (YFV) and the establishment of transmission cycles in endemic areas, such as Brazil. This study aims to investigate virological, histopathological and immunohistochemical findings in livers of squirrel monkeys (Saimiri spp.) infected with the YFV. Viremia occurred 1-30 days post infection (dpi) and the virus showed a predilection for the middle zone (Z2). The livers were jaundiced with subcapsular and hemorrhagic multifocal petechiae. Apoptosis, lytic and coagulative necrosis, steatosis and cellular edema were also observed. The immune response was characterized by the expression of S100, CD11b, CD57, CD4 and CD20; endothelial markers; stress and cell death; pro and anti-inflammatory cytokines, as well as Treg (IL-35) and IL-17 throughout the experimental period. Lesions during the severe phase of the disease were associated with excessive production of apoptotic pro-inflammatory cytokines, such as IFN-γ and TNF-α, released by inflammatory response cells (CD4+ and CD8+ T lymphocytes) and associated with high expression of molecules of adhesion in the inflammatory foci observed in Z2. Immunostaining of the local endothelium in vascular cells and the bile duct was intense, suggesting a fundamental role in liver damage and in the pathogenesis of the disease.


Asunto(s)
Fiebre Amarilla , Animales , Saimiri , Virus de la Fiebre Amarilla , Hígado , Citocinas
3.
Acta Trop ; 231: 106468, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35429458

RESUMEN

The early detection and diagnosis of deaths in free-ranging non-human primates (NHPs) are key points for the surveillance of Yellow Fever (YF) in Brazil. The histopathological identification of infectious diseases remains very useful and reliable in the screening and detection of emerging zoonotic diseases such as YF. We surveyed data records and liver slides stained with hematoxylin and eosin from the Epizootics Surveillance Network to control YF, Ministry of Health of Brazil, to evaluate histopathological hallmarks for the diagnosis of the YF virus infection. We selected natural fatal cases in NHPs from the genera Alouatta spp., Callithrix spp., and Sapajus spp. with a positive immunohistochemical assay for YF in liver samples. Our findings showed the full-spectrum YF-associated hepatic lesions in all NHPs, but some histopathological findings differed in the distribution and intensity between the three genera. In our study, South American NHPs showed significant differences in the YF-associated hepatic histopathological features compared to fatal cases reported in humans.


Asunto(s)
Alouatta , Fiebre Amarilla , Animales , Brasil/epidemiología , Callithrix , Fiebre Amarilla/epidemiología , Fiebre Amarilla/prevención & control , Virus de la Fiebre Amarilla , Zoonosis/epidemiología
4.
J Clin Med ; 7(12)2018 Nov 28.
Artículo en Inglés | MEDLINE | ID: mdl-30487475

RESUMEN

INTRODUCTION: The recent Zika virus(ZIKV) epidemic in Brazil was characterized by a range of different clinical presentations, particularly microcephaly, Guillain-Barré syndrome, and death. In this context, we determined the causal relationship between fatal microcephaly cases and ZIKV infection. METHODS: Twelve fatal cases of neonates, whose mothers were infected with ZIKV during pregnancy, were examined; cases included nine neonatal deaths due to microcephaly, one miscarriage, and two stillbirths. Tissue samples were obtained from all cases at necropsy and were submitted for virological investigation (RT-qPCR and virus isolation) and/or histopathology (hematoxylin and eosin staining) and immunohistochemical assay for the detection of ZIKV antigens. RESULTS: ZIKV antigens and/or ZIKV RNA were detected in tissue samples of all 12 cases examined. ZIKV was recovered in one case. Results of the virological and immunohistochemical analyses, as well as the anatomic abnormalities and histopathologic changes observed at necropsy on the 12 fatal cases, are presented. CONCLUSIONS: Data from these 12 cases provide strong evidence of the causal relationship between ZIKV and congenital disease in fetuses of women who were infected with the virus during pregnancy.

5.
Front Microbiol ; 9: 1879, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30154781

RESUMEN

Human T lymphotropic virus type 1 (HTLV-1) is the etiological agent of HTLV-1-associated myelopathy, and adult T cell lymphoma/leukemia (ATL/L). Pulmonary complications such as alveolitis and bronchiectasis were found in individuals who develop TSP/HAM due to chronic inflammation. These individuals showed image anomalies in CT scans and changes in pulmonary function parameters distinctive of pulmonary disease. Furthermore, infected individuals have a greater susceptibility to pulmonary tuberculosis either due to changes in the innate immune response, in asymptomatic carriers, or to an opportunistic disease linked to immunodepression, in individuals who develop ATL/L. This summary addresses the general lack of knowledge regarding the relationship between HTLV-1 and pulmonary diseases and provides direction for future work.

6.
Am J Pathol ; 188(11): 2644-2652, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-30121258

RESUMEN

Zika virus (ZIKV) is a single-stranded positive-sense RNA flavivirus that possesses a genome approximately 10.7 Kb in length. Although pro-inflammatory and anti-inflammatory cytokines and apoptotic markers belonging to the extrinsic and intrinsic pathways are suggested to be involved in fatal cases of ZIKV-induced microcephaly, their exact roles and associations are unclear. To address this, brain tissue samples were collected from 10 individuals, five of whom were diagnosed as ZIKV positive with microcephaly and a further five were flavivirus-negative controls that died because of other causes. Examination of material from the fatal cases of microcephaly revealed lesions in the cerebral cortex, edema, vascular proliferation, neuronal necrosis, gliosis, neuronophagy, calcifications, apoptosis, and neuron loss. The expression of various apoptosis markers in the neural parenchyma, including FasL, FAS, BAX, BCL2, and caspase 3 differed between ZIKV-positive cases and controls. Further investigation of type 1 and 2 helper T-cell cytokines confirmed a greater anti-inflammatory response in fatal ZIKV-associated microcephaly cases. Finally, an analysis of the linear correlation between tumor necrosis factor-α, IL-1ß, IL-4, IL-10, transforming growth factor-ß, and IL-33 expression and various apoptotic markers suggested that the immune response may be associated with the apoptotic phenomenon observed in ZIKV-induced microcephaly.


Asunto(s)
Apoptosis , Microcefalia/inmunología , Microcefalia/patología , Neuronas/inmunología , Tejido Parenquimatoso/inmunología , Infección por el Virus Zika/complicaciones , Virus Zika/patogenicidad , Citocinas/metabolismo , Femenino , Humanos , Recién Nacido , Masculino , Microcefalia/virología , Neuronas/patología , Neuronas/virología , Tejido Parenquimatoso/patología , Tejido Parenquimatoso/virología , Embarazo , Infección por el Virus Zika/virología
7.
Sci Rep ; 8(1): 1, 2018 01 08.
Artículo en Inglés | MEDLINE | ID: mdl-29311619

RESUMEN

Zika virus (ZIKV) has recently caused a pandemic disease, and many cases of ZIKV infection in pregnant women resulted in abortion, stillbirth, deaths and congenital defects including microcephaly, which now has been proposed as ZIKV congenital syndrome. This study aimed to investigate the in situ immune response profile and mechanisms of neuronal cell damage in fatal Zika microcephaly cases. Brain tissue samples were collected from 15 cases, including 10 microcephalic ZIKV-positive neonates with fatal outcome and five neonatal control flavivirus-negative neonates that died due to other causes, but with preserved central nervous system (CNS) architecture. In microcephaly cases, the histopathological features of the tissue samples were characterized in three CNS areas (meninges, perivascular space, and parenchyma). The changes found were mainly calcification, necrosis, neuronophagy, gliosis, microglial nodules, and inflammatory infiltration of mononuclear cells. The in situ immune response against ZIKV in the CNS of newborns is complex. Despite the predominant expression of Th2 cytokines, other cytokines such as Th1, Th17, Treg, Th9, and Th22 are involved to a lesser extent, but are still likely to participate in the immunopathogenic mechanisms of neural disease in fatal cases of microcephaly caused by ZIKV.


Asunto(s)
Sistema Nervioso Central/inmunología , Sistema Nervioso Central/metabolismo , Inmunidad , Microcefalia/etiología , Infección por el Virus Zika/complicaciones , Virus Zika , Apoptosis , Biomarcadores , Biopsia , Citocinas/metabolismo , Femenino , Humanos , Inmunohistoquímica , Recién Nacido , Mediadores de Inflamación/metabolismo , Masculino , Microcefalia/diagnóstico , Modelos Biológicos , Infección por el Virus Zika/virología
8.
Infect Dis Poverty ; 6(1): 82, 2017 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-28457229

RESUMEN

BACKGROUND: The impact of leprosy reduces health-related quality of life of affected patients, interfering with different factors such as nutrition. This study investigated the lipid profile, nutritional status, and risk for cardiovascular disease (CVD) in patients who underwent leprosy treatment in Brazil. METHODS: Eighty-four adult patients of both genders ranging in age from 20 to 60 years and diagnosed with paucibacillary (PB) or multibacillary (MB) leprosy were selected after undergoing multidrug treatment. The following data were collected: sociodemographic and clinical data; food intake; anthropometric measures (weight, height, and waist circumference); and lipid profile components (total cholesterol, high-density lipoprotein cholesterol [HDL-c], low-density lipoprotein cholesterol [LDL-c], and triglycerides). RESULTS: Among the study population, there was a predominance of males (65.48%) aged 50 to 60 years, patients with an income of 248-496 American dollars (63.10%), patients who completed elementary school (65.48%), inactive patients (76.19%), non-smokers (46.43%), and non-drinking patients (69.05%). The levels (mean ± standard deviation) of total cholesterol were 193.8 ± 29.4 mg/dL in the PB form and 203.5 ± 41.7 mg/dL in the MB form. The mean LDL-c was 116.9 ± 22.7 mg/dL in PB patients and 121 ± 31.3 mg/dL in MB patients. Mean triglyceride levels were 123.4 ± 45.2 mg/dL in the PB form and 147.4 ± 88.9 mg/dL in the MB form. The evaluation of nutritional status showed that 41.67% of the patients were eutrophic, while 55.96% had excess weight. Food intake was significantly associated with HDL-c in male patients (P = 0.0264) and with triglycerides in patients above the ideal weight (P = 0.0049). CONCLUSIONS: The risk of acquiring CVDs was observed to be high due to patients' excess weight and increased waist circumference. This study will guide clinicians in the adequate treatment of patients with leprosy in order to avoid adverse cardiovascular events.


Asunto(s)
Enfermedades Cardiovasculares/epidemiología , Colesterol/sangre , Lepra/tratamiento farmacológico , Lepra/epidemiología , Triglicéridos/sangre , Adulto , Tamaño Corporal/fisiología , Enfermedades Cardiovasculares/complicaciones , Estudios de Cohortes , Ingestión de Alimentos/fisiología , Femenino , Humanos , Lepra/complicaciones , Lepra/metabolismo , Masculino , Persona de Mediana Edad , Adulto Joven
10.
J Clin Virol ; 85: 56-64, 2016 12.
Artículo en Inglés | MEDLINE | ID: mdl-27835759

RESUMEN

BACKGROUND: Zika virus (ZIKV) was first detected in Brazil in May 2015 and the country experienced an explosive epidemic. However, recent studies indicate that the introduction of ZIKV occurred in late 2013. Cases of microcephaly and deaths associated with ZIKV infection were identified in Brazil in November, 2015. OBJECTIVES: To determine the etiology of three fatal adult cases. STUDY DESIGN: Here we report three fatal adult cases of ZIKV disease. ZIKV infection in these patients was confirmed by cells culture and/or real-time reverse transcriptase polymerase chain reaction (RT-qPCR) and by antigen detection using immunohistochemical assay. Samples of brain and other selected organs taken at autopsy from three patients were also analyzed by histopathological and immunohistological examination. RESULTS: The first patient, a 36-year-old man with lupus and receiving prednisone therapy, developed a fulminant ZIKV infection. At autopsy, RT-qPCR of blood and tissues was positive for ZIKV RNA, and the virus was cultured from an organ homogenate. The second patient, a previously healthy female, 16 years of age, presented classic symptoms of Zika fever, but later developed severe thrombocytopenia, anemia and hemorrhagic manifestations and died. A blood sample taken on the seventh day of her illness was positive RT-PCR for ZIKV RNA and research in the serum was positive for antinuclear factor fine speckled (1/640), suggesting Evans syndrome (hemolytic anemia an autoimmune disorder with immune thrombocytopenic purpura) secondary to ZIKV infection. The third patient was a 20-year-old woman hospitalized with fever, pneumonia and hemorrhages, who died on 13days after admission. Histopathological changes were observed in all viscera examined. ZIKV antigens were detected by immunohistochemistry in viscera specimens of patients 1 and 3. These three cases demonstrate other potential complications of ZIKV infection, in addition to microcephaly and Guillain-Barre syndrome (GBS), and they suggest that individuals with immune suppression and/or autoimmune disorders may be at higher risk of developing severe disease, if infected with ZIKV.


Asunto(s)
Infección por el Virus Zika/diagnóstico , Infección por el Virus Zika/patología , Virus Zika/aislamiento & purificación , Adolescente , Adulto , Antígenos Virales/análisis , Autopsia , Encéfalo/virología , Brasil , Resultado Fatal , Femenino , Humanos , Inmunohistoquímica , Masculino , ARN Viral/sangre , Reacción en Cadena en Tiempo Real de la Polimerasa , Cultivo de Virus , Vísceras/virología , Adulto Joven
11.
Viruses ; 8(1)2015 Dec 24.
Artículo en Inglés | MEDLINE | ID: mdl-26712781

RESUMEN

Human T-lymphotropic virus type-1 (HTLV-1) infection is associated with adult T-cell leukemia/lymphoma (ATL). Tropical spastic paraparesis/HTLV-1-associated myelopathy (PET/HAM) is involved in the development of autoimmune diseases including Rheumatoid Arthritis (RA), Systemic Lupus Erythematosus (SLE), and Sjögren's Syndrome (SS). The development of HTLV-1-driven autoimmunity is hypothesized to rely on molecular mimicry, because virus-like particles can trigger an inflammatory response. However, HTLV-1 modifies the behavior of CD4⁺ T cells on infection and alters their cytokine production. A previous study showed that in patients infected with HTLV-1, the activity of regulatory CD4⁺ T cells and their consequent expression of inflammatory and anti-inflammatory cytokines are altered. In this review, we discuss the mechanisms underlying changes in cytokine release leading to the loss of tolerance and development of autoimmunity.


Asunto(s)
Autoinmunidad , Infecciones por HTLV-I/inmunología , Virus Linfotrópico T Tipo 1 Humano/inmunología , Animales , Infecciones por HTLV-I/virología , Virus Linfotrópico T Tipo 1 Humano/genética , Virus Linfotrópico T Tipo 1 Humano/fisiología , Humanos
12.
Microb Pathog ; 78: 29-36, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25450888

RESUMEN

Jorge Lobo's disease is a rare mycosis characterized by chronic inflammation, which causes skin lesions in the absence of visceral dissemination. The disease occurs mainly in hot and humid climates and most cases have been registered in the Brazilian Amazon region. This study investigated possible microvascular alterations in skin lesions caused by infection with Lacazia loboi which may interfere with the clinical progression of the disease. Immunohistochemistry was used to evaluate the density of blood and lymphatic vessels, as well as expression of the cell adhesion molecules ICAM-1, VCAM-1 and E-selectin. The results showed a reduced number of blood (62.66 ± 20.30 vessels/mm(2)) and lymphatic vessels (3.55 ± 5.84 vessels/mm(2)) in Jorge Lobo's disease when compared to control skin (169.66 ± 66.38 blood vessels/mm(2) and 8 ± 2.17 lymphatic vessels/mm(2)). There were a larger number of vessels expressing ICAM-1 (27.58 ± 15.32 vessels/mm(2)) and VCAM-1 (7.55 ± 6.2 vessels/mm(2)). No difference was observed in the expression of E-selectin (4.66 ± 11 vessels/mm(2)). Taken together, the results indicate changes in the local microvasculature which may interfere with the development of an efficient cell-mediated immune response and may explain restriction of the fungus to the site of injury.


Asunto(s)
Células Endoteliales/patología , Lacazia/fisiología , Lobomicosis/patología , Microvasos/patología , Piel/irrigación sanguínea , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores/metabolismo , Brasil , Selectina E/genética , Selectina E/metabolismo , Células Endoteliales/metabolismo , Femenino , Humanos , Inmunohistoquímica , Molécula 1 de Adhesión Intercelular/genética , Molécula 1 de Adhesión Intercelular/metabolismo , Lobomicosis/genética , Lobomicosis/metabolismo , Lobomicosis/microbiología , Masculino , Microvasos/metabolismo , Microvasos/microbiología , Persona de Mediana Edad , Piel/metabolismo , Piel/patología , Molécula 1 de Adhesión Celular Vascular/genética , Molécula 1 de Adhesión Celular Vascular/metabolismo , Adulto Joven
13.
Rev Med Virol ; 23(5): 305-18, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23873723

RESUMEN

Yellow fever is a viral hemorrhagic fever, which affects people living in Africa and South America and is caused by the yellow fever virus, the prototype species in the Flavivirus genus (Flaviviridae family). Yellow fever virus infection can produce a wide spectrum of symptoms, ranging from asymptomatic infection or oligosymptomatic illness to severe disease with a high fatality rate. In this review, we focus in the mechanisms associated with the physiopathology of yellow fever in humans and animal models. It has been demonstrated that several factors play a role in the pathological outcome of the severe form of the disease including direct viral cytopathic effect, necrosis and apoptosis of hepatocyte cells in the midzone, and a minimal inflammatory response as well as low-flow hypoxia and cytokine overproduction. New information has filled several gaps in the understanding of yellow fever pathogenesis and helped comprehend the course of illness. Finally, we discuss prospects for an immune therapy in the light of new immunologic, viral, and pathologic tools.


Asunto(s)
Fiebre Amarilla/inmunología , Fiebre Amarilla/patología , Virus de la Fiebre Amarilla/inmunología , África , Animales , Modelos Animales de Enfermedad , Humanos , Inmunoterapia/métodos , América del Sur , Fiebre Amarilla/terapia , Virus de la Fiebre Amarilla/fisiología
14.
Microb Pathog ; 53(1): 44-8, 2012 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-22542711

RESUMEN

Case-control study based on the immunohistochemistry for TGF-ß1 evaluation of cervical samples obtained from two groups of women: CIN/HIV- and CIN/HIV+. Eleven women infected with HIV and with a histopathological diagnosis of CIN were included. The control group consisted of 12 patients with CIN. Cervical tissue samples obtained from all patients were submitted to histopathology and semiquantitative analysis of immunostaining for TGF-ß1 protein. In addition, the peripheral CD4+ cell count and viral load were evaluated in HIV + patients. Tissue expression of the cytokine was higher in the CIN/HIV+ group compared to control (p = 0.0023). In addition, higher TGF-ß1 expression was observed in higher grade cervical lesions in the two groups. There was a trend toward a direct correlation between peripheral CD4+ T cell count and tissue TGF-ß1, and toward an inverse correlation between viral load and cytokine expression. Thus, TGF-ß1 was more marked in situations in which cervical lesions are known to present a more aggressive behavior, suggesting that this cytokine is involved in the pathogenesis of tumor growth in these lesions. Tissue expression of TGF-ß1 is increased in cervical samples from HIV-infected women with CIN.


Asunto(s)
Síndrome de Inmunodeficiencia Adquirida/complicaciones , Síndrome de Inmunodeficiencia Adquirida/patología , Cuello del Útero/patología , Expresión Génica , Factor de Crecimiento Transformador beta1/biosíntesis , Displasia del Cuello del Útero/complicaciones , Displasia del Cuello del Útero/patología , Síndrome de Inmunodeficiencia Adquirida/inmunología , Adulto , Recuento de Linfocito CD4 , Estudios de Casos y Controles , Femenino , VIH/aislamiento & purificación , Humanos , Inmunohistoquímica , Carga Viral , Displasia del Cuello del Útero/inmunología
15.
J Virol Methods ; 174(1-2): 29-34, 2011 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-21419803

RESUMEN

Yellow fever virus (YFV), a member of the family Flaviviridae, genus Flavivirus is endemic to tropical areas of Africa and South America and is among the arboviruses that pose a threat to public health. Recent outbreaks in Brazil, Bolivia, and Paraguay and the observation that vectors capable of transmitting YFV are presenting in urban areas underscore the urgency of improving surveillance and diagnostic methods. Two novel methods (RT-hemi-nested-PCR and SYBR(®) Green qRT-PCR) for efficient detection of YFV strains circulating in South America have been developed. The methods were validated using samples obtained from golden hamsters infected experimentally with wild-type YFV strains as well as human serum and tissue samples with acute disease.


Asunto(s)
Técnicas de Diagnóstico Molecular/métodos , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/métodos , Virología/métodos , Fiebre Amarilla/diagnóstico , Virus de la Fiebre Amarilla/aislamiento & purificación , Animales , Cricetinae , Humanos , Mesocricetus , Suero/virología , América del Sur , Fiebre Amarilla/virología , Virus de la Fiebre Amarilla/genética
16.
Parasitol Int ; 58(2): 154-60, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19567230

RESUMEN

The present study analyses complement resistance, cell surface carbohydrates expression, lipidic composition and morphology in vivo and in vitro, of Leishmania (Viannia) shawi, a parasite identified in the Amazon region, Pará state, in 1989. We demonstrated that promastigotes in the stationary (STAT) growth phase are more resistant to complement lysis than in the logarithmic (LOG) growth phase. Ultrastructural analyses and imidazol technique showed accumulation of lipids in STAT growth phase promastigotes, which was confirmed by biochemical approach. Light and electron microscopy of skin lesion in hamster footpads caused by promastigotes in STAT growth phase, 90 days post inoculation, showed amastigotes inside of macrophage and free in the tissue surrounded by collagen fibers as well as extensive inflammatory reaction with tissue destruction. We also demonstrated, using lectins by agglutination assays and flow cytometry, the presence of fucose, mannose and/or glucose carbohydrate residues on the surface of LOG and STAT promastigotes. The results constitute the first characterization essay combining biochemical and morphological approaches dedicated to LOG and STAT growth phase promastigotes of L. (V) shawi contributing for a better knowledge of this poorly studied species of the New World.


Asunto(s)
Leishmania/clasificación , Leishmania/patogenicidad , Leishmaniasis Cutánea , Animales , Brasil , Carbohidratos/análisis , Carbohidratos/química , Proteínas del Sistema Complemento/inmunología , Cricetinae , Cobayas , Humanos , Lectinas/metabolismo , Leishmania/crecimiento & desarrollo , Leishmania/ultraestructura , Leishmaniasis Cutánea/inmunología , Leishmaniasis Cutánea/parasitología , Leishmaniasis Cutánea/patología , Mesocricetus , Microscopía/instrumentación , Microscopía Electrónica
17.
Int J Exp Pathol ; 88(1): 63-73, 2007 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-17244340

RESUMEN

Minaçu virus was isolated from Ochlerotatus scapularis (Diptera: Culicidae) in Minaçu, Goiás State, Brazil, in 1996. In attempting characterization of virus serological (hemagluttination inhibition, HI; indirect immunofluorescence assay, IFA), physicochemical [test for deoxycholate acid (DCA) sensitivity; polyacrylamide gel electrophoresis (PAGE)] tests and ultrastructural studies were made. Virus was also assayed in suckling mice after intracerebral inoculation of 0.02 ml and in VERO and C6/36 cells with 0.1 ml of viral suspension containing 10(5) LD50/ml. Inoculated and control systems were observed daily. Every 24 h, one control and two inoculated animals were killed for tissue testing, including histopathological changes by haematoxylin and eosin (HE)-stained sections, which were semi-quantified. Research into viral antigen in the tissues of mice [central nervous system (CNS), liver, heart, lungs, spleen and kidneys] was carried out by the immunohistochemical technique using the peroxidase system. The virus only replicated in VERO cells, with antigen positive by IFA. Positive complement fixation tests were only obtained using antiserum of Minaçu virus. Minaçu virus is DCA resistant; haemagglutinating activity was negative. By electronic microscopy non-enveloped virus particles were 75 nm in diameter. PAGE analysis showed Minaçu virus genome profile with 10 RNA segments. Infected, non-killed animals died 7 days after inoculation. Tissue lesions were observed in all organs, except the lungs. Intense lesions were observed in the CNS and the heart, where neurone and cardiocyte necroses, respectively, were noted. The liver, spleen and kidneys had moderate tissue changes. Viral antigens were more abundant in the CNS and the heart, and absent in the lungs. In conclusion, Minaçu virus belongs to the family Reoviridae, genus Orbivirus.


Asunto(s)
Orbivirus/aislamiento & purificación , Infecciones por Reoviridae/patología , Animales , Animales Lactantes , Antígenos Virales/sangre , Brasil , Línea Celular , Chlorocebus aethiops , Pruebas de Fijación del Complemento , Ácido Desoxicólico/farmacología , Detergentes/farmacología , Técnica del Anticuerpo Fluorescente , Ratones , Ratones Endogámicos , Microscopía Electrónica , Orbivirus/inmunología , Orbivirus/patogenicidad , ARN Viral/sangre , Células Vero
18.
Trans R Soc Trop Med Hyg ; 101(2): 161-8, 2007 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-16872652

RESUMEN

The study of the in-situ cellular immune response is very important for the understanding of different liver infections. In the present study, 53 liver samples obtained by viscerotomy from patients who died during the course of jungle yellow fever were analyzed. The diagnosis was confirmed by serology, viral isolation and virus-specific immunohistochemistry. The specimens were analyzed by immunohistochemistry using specific antibodies for apoptosis, CD45RO, CD4, CD8, CD20, S100, CD57 and CD68. Quantitative analysis of the labeling pattern showed a clear predominance of the different phenotypes in the portal tract and midzone region of the acini. There was a predominance of T CD4+ lymphocytes, accompanied by the presence of T CD8+ lymphocytes, natural killer cells (CD57), macrophages and antigen-presenting cells (S100). The disproportion between the intensity of inflammation and the degree of hepatic injury was probably due to the intense apoptotic component, which classically does not induce an inflammatory response. The present study demonstrates that, despite the disproportion between injury and inflammation, the cellular immune response plays an important role in the pathogenesis of the hepatocytic injury observed in yellow fever, probably as a result of cytolytic actions through mechanisms involving MHC II and the activation of Fas receptors and granzymes/perforins.


Asunto(s)
Hepatocitos/patología , Fiebre Amarilla/patología , Análisis de Varianza , Anticuerpos Antivirales/inmunología , Biomarcadores , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD8-positivos/inmunología , Femenino , Hepatocitos/inmunología , Humanos , Inmunidad Celular , Inmunohistoquímica , Masculino , Proteínas S100/inmunología , Fiebre Amarilla/inmunología , Virus de la Fiebre Amarilla/inmunología
20.
Med Hypotheses ; 67(3): 618-21, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-16650626

RESUMEN

Yellow fever is an acute infectious, non-contagious disease characterized by intense vasculopathy and lesions in different organs. In the liver, one of the main targets of the virus, the infection induces a characteristic midzonal injury characterized by hepatocyte necrosis, apoptosis and steatosis. This characteristics pattern of liver injury in yellow fever is also observed in conditions of low-flow hypoxia and other infections such as dengue and Rift Valley fever. There are no reports in the literature explaining the genesis of this peculiar histopathological pattern in yellow fever. Some hypotheses have been proposed to explain the mechanism of this midzonal distribution pattern observed in the liver such as low-flow hypoxia and tropism of the virus toward hepatocytes in this area. These hypotheses are discussed in view of more recent findings regarding the pathogenesis of yellow fever and regarding hepatic physiopathology, and a new hypothesis is proposed: the midzonal necrosis is consequence of action of combined factors mainly the direct cytopathic effect of YFV associated with a potent immune response in which CD4+ and CD8+ lymphocytes and the cytokines, especially TGF-beta, but also TNF-alpha and IFN-gamma play an important role.


Asunto(s)
Hepatocitos/patología , Hepatocitos/virología , Hígado/lesiones , Fiebre Amarilla/inmunología , Fiebre Amarilla/patología , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD8-positivos/inmunología , Humanos , Inflamación/patología , Interferón gamma/inmunología , Modelos Inmunológicos , Necrosis/patología , Factor de Necrosis Tumoral alfa/inmunología , Fiebre Amarilla/virología , Virus de la Fiebre Amarilla/aislamiento & purificación
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