RESUMEN
BACKGROUND: A unified set of criteria for neurocysticercosis (NCC) has helped to standardize its diagnosis in different settings. METHODS: Cysticercosis experts were convened to update current diagnostic criteria for NCC according to two principles: neuroimaging studies are essential for diagnosis, and all other information provides indirect evidence favoring the diagnosis. Recent diagnostic advances were incorporated to this revised set. RESULTS: This revised set is structured in absolute, neuroimaging and clinical/exposure criteria. Absolute criteria include: histological confirmation of parasites, evidence of subretinal cysts, and demonstration of the scolex within a cyst. Neuroimaging criteria are categorized as major (cystic lesions without scolex, enhancing lesions, multilobulated cysts, and calcifications), confirmative (resolution of cysts after cysticidal drug therapy, spontaneous resolution of single enhancing lesions, and migrating ventricular cysts on sequential neuroimaging studies) and minor (hydrocephalus and leptomeningeal enhancement). Clinical/exposure criteria include: detection of anticysticercal antibodies or cysticercal antigens by well-standardized tests, systemic cysticercosis, evidence of a household Taenia carrier, suggestive clinical manifestations, and residency in endemic areas. Besides patients having absolute criteria, definitive diagnosis can be made in those having two major neuroimaging criteria (or one major plus one confirmative criteria) plus exposure. For patients presenting with one major and one minor neuroimaging criteria plus exposure, definitive diagnosis of NCC requires the exclusion of confounding pathologies. Probable diagnosis is reserved for individuals presenting with one neuroimaging criteria plus strong evidence of exposure. CONCLUSIONS: This revised set of diagnostic criteria provides simpler definitions and may facilitate its more uniform and widespread applicability in different scenarios.
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Neurocisticercosis/diagnóstico , Encéfalo/diagnóstico por imagen , Humanos , NeuroimagenRESUMEN
OBJECTIVE: To determine the frequency of spinal neurocysticercosis (NCC) in patients with basal subarachnoid NCC compared with that in individuals with viable limited intraparenchymal NCC (≤20 live cysts in the brain). METHODS: We performed a prospective observational case-control study of patients with NCC involving the basal cisterns or patients with only limited intraparenchymal NCC. All patients underwent MRI examinations of the brain and the entire spinal cord to assess spinal involvement. RESULTS: Twenty-seven patients with limited intraparenchymal NCC, and 28 patients with basal subarachnoid NCC were included in the study. Spinal involvement was found in 17 patients with basal subarachnoid NCC and in only one patient with limited intraparenchymal NCC (odds ratio 40.18, 95% confidence interval 4.74-340.31; p < 0.0001). All patients had extramedullary (intradural) spinal NCC, and the lumbosacral region was the most frequently involved (89%). Patients with extensive spinal NCC more frequently had ventriculoperitoneal shunt placement (7 of 7 vs 3 of 11; p = 0.004) and tended to have a longer duration of neurologic symptoms than those with regional involvement (72 months vs 24 months; p = 0.062). CONCLUSIONS: The spinal subarachnoid space is commonly involved in patients with basal subarachnoid NCC, compared with those with only intraparenchymal brain cysts. Spinal cord involvement probably explains serious late complications including chronic meningitis and gait disorders that were described before the introduction of antiparasitic therapy. MRI of the spine should be performed in basal subarachnoid disease to document spinal involvement, prevent complications, and monitor for recurrent disease.
Asunto(s)
Imagen por Resonancia Magnética , Neurocisticercosis/diagnóstico , Enfermedades de la Columna Vertebral/diagnóstico , Espacio Subaracnoideo , Tomografía Computarizada por Rayos X , Adolescente , Adulto , Anciano , Encéfalo/patología , Estudios de Casos y Controles , Estudios Transversales , Progresión de la Enfermedad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Neurocisticercosis/epidemiología , Examen Neurológico , Perú , Médula Espinal/patología , Enfermedades de la Columna Vertebral/epidemiología , Derivación Ventriculoperitoneal , Adulto JovenRESUMEN
In cases of cysticercosis, seizures and other symptoms occur in persons with only calcified brain lesions. The presence of perilesional edema has been documented in association with calcified lesions in symptomatic patients, but the frequency of this complication and characteristics of the patients who develop it are not known. Patients in Peru and the United States with neurocysticercosis, documented by positive results of serological testing and with only calcified lesions as shown using computerized tomography, were studied using magnetic resonance imaging. Perilesional edema was observed in slightly more than one-third of the patients, and some patients had frequent, severely disabling episodes. Those with an increased proportion of enhancing calcified lesions were more likely to show perilesional edema. Edema around calcified lesions is common in this population and is associated with seizures and neurological morbidity.
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Encefalopatías/complicaciones , Edema Encefálico/etiología , Calcinosis/complicaciones , Neurocisticercosis/complicaciones , Convulsiones/etiología , Adolescente , Adulto , Animales , Encefalopatías/parasitología , Edema Encefálico/diagnóstico por imagen , Calcinosis/diagnóstico por imagen , Calcinosis/parasitología , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Neurocisticercosis/parasitología , Perú , Convulsiones/diagnóstico por imagen , Tomografía Computarizada por Rayos X , Estados UnidosRESUMEN
Neurocysticercosis is the most common helminthic infection of the CNS but its diagnosis remains difficult. Clinical manifestations are nonspecific, most neuroimaging findings are not pathognomonic, and some serologic tests have low sensitivity and specificity. The authors provide diagnostic criteria for neurocysticercosis based on objective clinical, imaging, immunologic, and epidemiologic data. These include four categories of criteria stratified on the basis of their diagnostic strength, including the following: 1) absolute--histologic demonstration of the parasite from biopsy of a brain or spinal cord lesion, cystic lesions showing the scolex on CT or MRI, and direct visualization of subretinal parasites by funduscopic examination; 2) major--lesions highly suggestive of neurocysticercosis on neuroimaging studies, positive serum enzyme-linked immunoelectrotransfer blot for the detection of anticysticercal antibodies, resolution of intracranial cystic lesions after therapy with albendazole or praziquantel, and spontaneous resolution of small single enhancing lesions; 3) minor--lesions compatible with neurocysticercosis on neuroimaging studies, clinical manifestations suggestive of neurocysticercosis, positive CSF enzyme-linked immunosorbent assay for detection of anticysticercal antibodies or cysticercal antigens, and cysticercosis outside the CNS; and 4) epidemiologic--evidence of a household contact with Taenia solium infection, individuals coming from or living in an area where cysticercosis is endemic, and history of frequent travel to disease-endemic areas. Interpretation of these criteria permits two degrees of diagnostic certainty: 1) definitive diagnosis, in patients who have one absolute criterion or in those who have two major plus one minor and one epidemiologic criterion; and 2) probable diagnosis, in patients who have one major plus two minor criteria, in those who have one major plus one minor and one epidemiologic criterion, and in those who have three minor plus one epidemiologic criterion.
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Neurocisticercosis/diagnóstico , HumanosRESUMEN
Microsporidia (phylum Microspora) are unicellular parasites commonly found in invertebrates, fish, and laboratory animals; however, microsporidiosis is an emerging problem in patients with the acquired immunodeficiency syndrome (AIDS). The infective stage of these parasites is the spore, which possesses a rigid cell wall that protects the parasite outside its host. Little is known about their antigenic composition. Sensitive, reliable, and easily performed methods for identification and speciation are generally not available. Here, we report the production of 21 MAbs specific to spore antigens of several species of Microsporidia. MAbs were generated to purified spores of Encephalitozoon intestinalis and Encephalitozoon hellem, and their reactivities were tested against spores and intracellular developing forms of E. intestinalis, E. hellem, Encephalitozoon cuniculi, and Vittaforma corneae. Both species-specific and broad-reactivity MAbs were produced. Five MAbs reacted against the spores of all four species tested: 7 with 3 species, 6 with 2 species, 1 with E. intestinalis, and 4 with the polar tube of all species. Immunoelectron microscopy confirmed the reactivity of specific MAbs to the spore wall or the polar tube. These MAbs reacted to a few antigens as determined by Western blot, and none of the epitopes were periodate-sensitive. These MAbs may be useful in the diagnosis and speciation of Microsporidia as well in the purification, cloning, and detection of these antigens.
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Anticuerpos Monoclonales/inmunología , Anticuerpos Antiprotozoarios/inmunología , Antígenos de Protozoos/inmunología , Microsporida/inmunología , Esporas/inmunología , Animales , Anticuerpos Monoclonales/aislamiento & purificación , Especificidad de AnticuerposRESUMEN
The protozoan parasite Giardia lamblia is transmitted as an environmentally resistant cyst. The encystation process is attracting attention not only from the viewpoint of disease transmission, but also as a model for differentiation. Here, Hugo Luján, Michael Mowatt and Theodore Nash discuss molecular events underlying this process, including the induction of expression and transport of cyst wall proteins and the induction of Golgi-like activity. They also propose that the signal for encystation derives from cholesterol deprivation in the lower small intestine.
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Microbiologists have long been intrigued by the ability of parasitic organisms to adapt to changes in the environment. Since most parasites occupy several niches during their journey between vectors and hosts, they have developed adaptive responses which allow them to survive under adverse conditions. Therefore, the life cycles of protozoan and helminthic parasites are excellent models with which to study numerous mechanisms involved in cell differentiation, such as the regulation of gene expression, signal transduction pathways, and organelle biogenesis. Unfortunately, many of these studies are very difficult because the conditions needed to elicit developmental changes in parasites remain undetermined in most cases. Recently, several interesting findings were reported on the process of differentiation of Giardia lamblia trophozoites into cysts. G. lamblia is a flagellated protozoan that inhabits the upper small intestine of its vertebrate host and is a major cause of enteric disease worldwide. It belongs to the earliest identified lineage among eukaryotes and therefore offers a unique insight into the progression from primitive to more complex eukaryotic cells. The discovery of a specific stimulus that induces trophozoites to differentiate into cysts, the identification and characterization of encystation-specific molecules, the elucidation of novel biochemical pathways, and the development of useful reagents and techniques have made this parasite an excellent model with which to study differentiation in eukaryotic cells. In this review, we summarize the most recent fundings on several aspects of Giardia differentiation and discuss the significance of these findings within the context of current knowledge in the field.
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Giardia lamblia/crecimiento & desarrollo , Animales , Transporte Biológico , Pared Celular/metabolismo , Giardia lamblia/citología , Giardia lamblia/metabolismoRESUMEN
During the summer of 1980, acute Manson's Schistosomiasis occurred in 28 pediatric patients, swimming in two ponds with no watershed connections between them, in the rural area of Juncos and Cidra, Puerto Rico. Clinical and immunological events were studied and Oxamniquine (Vansil, Pfizer) was administered to all of them and followed closely for 3 years. Fever and general malaise recorded in 93 of the patients, diarrhea and abdominal pain in 68 and urticaria or facial edema in 64. Hepato and/or splenomegaly was recorded in 71 of them. Twenty seven of the patients had evidence of immunoserological activity against adult schistosomal antigens (GASP and PSAP). Two patients had intense immunologic activity, even before the recovering of fresh Schistosoma mansoni eggs in their stool. This was a response to GASP and PSAP antigens. When they started passing fresh eggs of schistosoma and COP (Circumoval Precipitation Test) turned positive, their clinical status worsened and antibodies to GASP antigen increased two fold. The oviposition phase elicited a strong antibody and immunological reaction with significant eosinophilia and cross reaction was observed between adult schistosomal and egg shell antigens. Severe clinical manifestations were seen in spite of low egg excretion. Oxamniquine was effective in obtaining a coprological cure and in altering the immunologic response as compared with other untreated groups in literature
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Humanos , Niño , Adolescente , Esquistosomicidas/uso terapéutico , Esquistosomiasis/tratamiento farmacológico , Oxamniquina/uso terapéutico , Enfermedad Aguda , Brotes de Enfermedades , Esquistosomiasis/epidemiología , Puerto Rico/epidemiologíaRESUMEN
During the summer of 1980, acute Manson's Schistosomiasis occurred in 28 pediatric patients, swimming in two ponds with no watershed connections between them, in the rural area of Juncos and Cidra, Puerto Rico. Clinical and immunological events were studied and Oxamniquine (Vansil, Pfizer) was administered to all of them and followed closely for 3 years. Fever and general malaise recorded in 93% of the patients, diarrhea and abdominal pain in 68% and urticaria or facial edema in 64%. Hepato and/or splenomegaly was recorded in 71% of them. Twenty seven of the patients had evidence of immunoserological activity against adult schistosomal antigens (GASP and PSAP). Two patients had intense immunologic activity, even before the recovering of fresh Schistosoma mansoni eggs in their stool. This was a response to GASP and PSAP antigens. When they started passing fresh eggs of schistosoma and COP (Circumoval Precipitation Test) turned positive, their clinical status worsened and antibodies to GASP antigen increased two fold. The oviposition phase elicited a strong antibody and immunological reaction with significant eosinophilia and cross reaction was observed between adult schistosomal and egg shell antigens. Severe clinical manifestations were seen in spite of low egg excretion. Oxamniquine was effective in obtaining a coprological cure and in altering the immunologic response as compared with other untreated groups in literature.
Asunto(s)
Oxamniquina/uso terapéutico , Esquistosomiasis/tratamiento farmacológico , Esquistosomicidas/uso terapéutico , Enfermedad Aguda , Adolescente , Niño , Brotes de Enfermedades , Humanos , Puerto Rico/epidemiología , Esquistosomiasis/epidemiologíaRESUMEN
The trophozoite antigens of Giardia lamblia to which host humoral and cellular immune responses are directed have not been identified. Therefore, we initiated studies to characterize these antigens in strains of G. lamblia from Afghanistan, Oregon, Ecuador, and Puerto Rico. By polyacrylamide gel electrophoresis, the electrophoretic mobility patterns of proteins of the four strains were similar; molecular weights of protein bands ranged between 12,000 and 140,000. The antigens which reacted with rabbit and anti-G. lamblia antisera by immunoelectrophoresis were also similar for the four strains. However, comparison by crossed immunoelectrophoresis showed the Oregon strain, which has been the longest in culture, lacked a set of anodic antigens and the single neutral antigen which were present in the other three strains. In addition, other minor antigen differences between the strains were detected by this technique. When we employed trophozoites from each strain as antigen in an enzyme-linked immunosorbent assay against 10 human antisera of various liters, we also detected some differences between the strains. Although polyacrylamide gel electrophoresis and immunoelectrophoresis revealed gross similarity among G. lamblia from widely differing geographic locations, subtle differences detected by crossed electrophoresis and enzyme-linked immunosorbent assay suggest the existence of potentially important antigenic differences among these strains.