RESUMEN
Inflammatory bowel diseases (IBD) are a group of chronic inflammatory conditions of the gastrointestinal tract associated with multiple pathogenic factors, including dysregulation of the immune response. Effector CD4+ T cells and regulatory CD4+ T cells (Treg) are central players in maintaining the balance between tolerance and inflammation. Interestingly, genetic modifications in these cells have been implicated in regulating the commitment of specific phenotypes and immune functions. However, the transcriptional program controlling the pathogenic behavior of T helper cells in IBD progression is still unknown. In this study, we aimed to find master transcription regulators controlling the pathogenic behavior of effector CD4+ T cells upon gut inflammation. To achieve this goal, we used an animal model of IBD induced by the transfer of naïve CD4+ T cells into recombination-activating gene 1 (Rag1) deficient mice, which are devoid of lymphocytes. As a control, a group of Rag1-/- mice received the transfer of the whole CD4+ T cells population, which includes both effector T cells and Treg. When gut inflammation progressed, we isolated CD4+ T cells from the colonic lamina propria and spleen tissue, and performed bulk RNA-seq. We identified differentially up- and down-regulated genes by comparing samples from both experimental groups. We found 532 differentially expressed genes (DEGs) in the colon and 30 DEGs in the spleen, mostly related to Th1 response, leukocyte migration, and response to cytokines in lamina propria T-cells. We integrated these data into Gene Regulatory Networks to identify Master Regulators, identifying four up-regulated master gene regulators (Lef1, Dnmt1, Mybl2, and Jup) and only one down-regulated master regulator (Foxo3). The altered expression of master regulators observed in the transcriptomic analysis was confirmed by qRT-PCR analysis and found an up-regulation of Lef1 and Mybl2, but without differences on Dnmt1, Jup, and Foxo3. These two master regulators have been involved in T cells function and cell cycle progression, respectively. We identified two master regulator genes associated with the pathogenic behavior of effector CD4+ T cells in an animal model of IBD. These findings provide two new potential molecular targets for treating IBD.
Asunto(s)
Linfocitos T CD4-Positivos , Redes Reguladoras de Genes , Enfermedades Inflamatorias del Intestino , Animales , Enfermedades Inflamatorias del Intestino/genética , Enfermedades Inflamatorias del Intestino/inmunología , Enfermedades Inflamatorias del Intestino/metabolismo , Enfermedades Inflamatorias del Intestino/patología , Ratones , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD4-Positivos/metabolismo , Modelos Animales de Enfermedad , Linfocitos T Reguladores/inmunología , Linfocitos T Reguladores/metabolismo , Ratones Endogámicos C57BL , Ratones Noqueados , Regulación de la Expresión GénicaRESUMEN
Huntington's disease (HD) is a disorder caused by an abnormal expansion of trinucleotide CAG repeats within the huntingtin (Htt) gene. Under normal conditions, the CREB Binding Protein interacts with CREB elements and acetylates Lysine 27 of Histone 3 to direct the expression of several genes. However, mutant Htt causes depletion of CBP, which in turn induces altered histone acetylation patterns and transcriptional deregulation. Here, we have studied a differential expression analysis and H3K27ac variation in 4- and 6-week-old R6/2 mice as a model of juvenile HD. The analysis of differential gene expression and acetylation levels were integrated into Gene Regulatory Networks revealing key regulators involved in the altered transcription cascade. Our results show changes in acetylation and gene expression levels that are related to impaired neuronal development, and key regulators clearly defined in 6-week-old mice are proposed to drive the downstream regulatory cascade in HD. Here, we describe the first approach to determine the relationship among epigenetic changes in the early stages of HD. We determined the existence of changes in pre-symptomatic stages of HD as a starting point for early onset indicators of the progression of this disease.
Asunto(s)
Enfermedad de Huntington , Ratones , Animales , Enfermedad de Huntington/genética , Enfermedad de Huntington/metabolismo , Histonas/genética , Histonas/metabolismo , Acetilación , Modelos Animales de Enfermedad , Epigénesis Genética , Proteína Huntingtina/genética , Proteína Huntingtina/metabolismoRESUMEN
The comparative pharmacokinetics of ivermectin (IVM), between healthy and in Escherichia coli lipopolysaccharides (LPS) injected sheep, was investigated after an intravenous (IV) administration of a single dose of 0.2 mg/kg. Ten Suffolk Down sheep, 55 ± 3.3 kg, were distributed in two experimental groups: Group 1 (LPS): treated with three doses of 1 µg LPS/kg bw at -24, -16, and -0.75 hr before IVM; group 2 (Control): treated with saline solution (SS). An IV dose of 0.2 mg IVM/kg was administered 45 min after the last injection of LPS or SS. Plasma concentrations of IVM were determined by liquid chromatography. Pharmacokinetic parameters were calculated based on non-compartmental modeling. In healthy sheep, the values of the pharmacokinetic parameters were as follows: elimination half-life (2.85 days), mean residence time (MRT) (2.27 days), area under the plasma concentration curve over time (AUC, 117.4 ng day-1 ml-1 ), volume of distribution (875.6 ml/kg), and clearance (187.1 ml/day). No statistically significant differences were observed when compared with the results obtained from the group of sheep treated with LPS. It is concluded that the acute inflammatory response (AIR) induced by the intravenous administration of E. coli LPS in adult sheep produced no changes in plasma concentrations or in the pharmacokinetic behavior of IVM, when it is administered intravenously at therapeutic doses.
Asunto(s)
Antiparasitarios/farmacocinética , Endotoxinas/farmacología , Ivermectina/farmacocinética , Animales , Antiparasitarios/administración & dosificación , Antiparasitarios/sangre , Cromatografía Liquida/veterinaria , Femenino , Inyecciones Intravenosas/veterinaria , Ivermectina/administración & dosificación , Ivermectina/sangre , Masculino , Ovinos/metabolismo , Enfermedades de las Ovejas/metabolismo , Enfermedades de las Ovejas/microbiologíaRESUMEN
The L-type calcium channel (LTCC) is an important determinant of cardiac contractility. Therefore, changes in LTCC activity or protein levels could be expected to affect cardiac function. Several studies describing LTCC regulation are available, but only a few examine LTCC protein stability. Polycystin-1 (PC1) is a mechanosensor that regulates heart contractility and is involved in mechanical stretch-induced cardiac hypertrophy. PC1 was originally described as an unconventional Gi/o protein-coupled receptor in renal cells. We recently reported that PC1 regulates LTCC stability in cardiomyocytes under stress; however, the mechanism underlying this effect remains unknown. Here, we use cultured neonatal rat ventricular myocytes and hypo-osmotic stress (HS) to model mechanical stretch. The model shows that the Cavß2 subunit is necessary for LTCC stabilization in cardiomyocytes during mechanical stretch, acting through an AKT-dependent mechanism. Our data also shows that AKT activation depends on the G protein-coupled receptor activity of PC1, specifically its G protein-binding domain, and the associated Gßγ subunit of a heterotrimeric Gi/o protein. In fact, over-expression of the human PC1 C-terminal mutant lacking the G protein-binding domain blunted the AKT activation-induced increase in Cav1.2 protein in cardiomyocytes. These findings provide novel evidence that PC1 is involved in the regulation of cardiac LTCCs through a Gißγ-AKT-Cavß2 pathway, suggesting a new mechanism for regulation of cardiac function.
Asunto(s)
Canales de Calcio Tipo L/metabolismo , Miocitos Cardíacos/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Transducción de Señal , Estrés Mecánico , Canales Catiónicos TRPP/metabolismo , Animales , Canales de Calcio Tipo L/genética , Proteínas Proto-Oncogénicas c-akt/genética , Ratas , Canales Catiónicos TRPP/genéticaRESUMEN
Evidence from systems biology indicates that promiscuous drugs, i.e. those that act simultaneously at various protein targets, are clinically better in terms of efficacy, than those that act in a more selective fashion. This has generated a new trend in drug development called polypharmacology. However, the rational design of promiscuous compounds is a difficult task, particularly when the drugs are aimed to act at receptors with diverse structure, function and endogenous ligand. In the present work, using docking and molecular dynamics methodologies, we established the most probable binding sites of SB-206553, a drug originally described as a competitive antagonist of serotonin type 2B/2C metabotropic receptors (5-HT2B/2CRs) and more recently as a positive allosteric modulator of the ionotropic α7 nicotinic acetylcholine receptor (nAChR). To this end, we employed the crystal structures of the 5-HT2BR and acetylcholine binding protein as templates to build homology models of the 5-HT2CR and α7 nAChR, respectively. Then, using a statistical algorithm, the similarity between these binding sites was determined. Our analysis showed that the most plausible binding sites for SB-206553 at 5-HT2Rs and α7 nAChR are remarkably similar, both in size and chemical nature of the amino acid residues lining these pockets, thus providing a rationale to explain its affinity towards both receptor types. Finally, using a computational tool for multiple binding site alignment, we determined a consensus binding site, which should be useful for the rational design of novel compounds acting simultaneously at these two types of highly different protein targets.
Asunto(s)
Indoles/química , Piridinas/química , Receptores de Serotonina 5-HT2/química , Receptor Nicotínico de Acetilcolina alfa 7/química , Secuencia de Aminoácidos , Animales , Sitios de Unión/genética , Unión Competitiva , Humanos , Indoles/metabolismo , Indoles/farmacología , Simulación de Dinámica Molecular , Datos de Secuencia Molecular , Estructura Molecular , Unión Proteica , Isoformas de Proteínas/química , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Estructura Terciaria de Proteína , Piridinas/metabolismo , Piridinas/farmacología , Receptores de Serotonina 5-HT2/genética , Receptores de Serotonina 5-HT2/metabolismo , Homología de Secuencia de Aminoácido , Antagonistas de la Serotonina/química , Antagonistas de la Serotonina/metabolismo , Antagonistas de la Serotonina/farmacología , Receptor Nicotínico de Acetilcolina alfa 7/genética , Receptor Nicotínico de Acetilcolina alfa 7/metabolismoRESUMEN
The plasma kinetic profile of moxidectin (MXD) in ewes during the last third of pregnancy was studied after the subcutaneous dose of 0.2 mg/kg of body weight (bw). Two groups of sheep (n = 7) that were equally balanced in body weight were used. Group I (control) was maintained unmated, while Group II (pregnant) was estrous-synchronized and mated with fertile rams. Both groups were maintained under similar conditions regarding management and feeding. When the ewes from Group II fulfilled 120 days of pregnancy, both groups were treated with a subcutaneous injection of 0.2 mg of MXD/kg bw. Blood samples were collected at different set times between 1 h and 40 days post-treatment. After plasma extraction and derivatization, the samples were analyzed using high-performance liquid chromatography with fluorescence detection. A noncompartmental pharmacokinetic analysis was performed, and the data were compared using Student's t-test. The mean pharmacokinetic parameters, including Cmax , Tmax , and the area under the concentration-time curve (AUC), were similar for both groups of sheep. The average of elimination half-life was significantly lower (P = 0.0023) in the pregnant (11.49 ± 2.2 days) vs. the control (17.89 ± 4.84 days) sheep. Similarly, the mean residence time (MRT) for the pregnant group (20.6 ± 3.8 days) was lower (P = 0.037) than that observed in the control group (27.4 ± 9.1 days). It is concluded that pregnancy produces a significant decrease in mean values of half-life of elimination of MXD, indicating that pregnancy can increase the rate of elimination of the drug reducing their permanence in the body.
Asunto(s)
Antinematodos/farmacocinética , Macrólidos/farmacocinética , Ovinos/metabolismo , Animales , Antinematodos/administración & dosificación , Antinematodos/sangre , Estudios de Casos y Controles , Femenino , Inyecciones Subcutáneas/veterinaria , Macrólidos/administración & dosificación , Macrólidos/sangre , Infecciones por Nematodos/tratamiento farmacológico , Infecciones por Nematodos/prevención & control , Infecciones por Nematodos/veterinaria , Embarazo , Ovinos/parasitología , Enfermedades de las Ovejas/tratamiento farmacológico , Enfermedades de las Ovejas/prevención & controlRESUMEN
Two unidentified graves were found during construction of a new crypt at the Metropolitan Cathedral in Santiago, Chile. One of the bodies was sent to the Teaching Hospital of the University of Chile for forensic identification. The fully mummified corpse was suspected to be that of Diego Portales, a prominent Chilean politician who was assassinated in 1837. The condition of the corpse determined that the best way to establish a positive identification was by means of a multislice CT scan, since the body had been autopsied and embalmed using unknown substances. This paper presents the results of the virtual autopsy of the remains and compares these results with the original autopsy report of 1837. The embalming method is also discussed, based on chemical analysis using inductively coupled mass spectroscopy (ICP-MS) and cold vapour atomic absorption spectrometry (HG-CVAAS).
Asunto(s)
Autopsia/métodos , Antropología Forense/métodos , Homicidio/historia , Chile , Embalsamiento , Historia del Siglo XIX , Humanos , Masculino , Momias , Tomografía Computarizada por Rayos X/métodos , Imagen de Cuerpo Entero/métodos , Heridas por Arma de Fuego/diagnóstico por imagen , Heridas por Arma de Fuego/historiaRESUMEN
El Trauma Raquimedular (TRM) es el resultado del daño18, 19 producido por lesiones traumáticas vertebrales a cualquier nivel y que comprometen a las diferentes estructuras que componen la columna vertebral, particularmente la médula espinal o sus raíces. Su incidencia14, 16 varía entre 11.5 y 53.4 por cada millón de habitantes y la causa más frecuente en nuestro país son las caídas. La región cervical es la más afectada seguida de la unión toracolumbar. Los segmentos torácicos y lumbares se comprometen con menor frecuencia, siendo similar en ambos niveles. Es una patología catastrófica para los pacientes y sus familias, ya que habitualmente los afectados son personas jóvenes en edad productiva17. Conjuntamente con el inmenso problema social, esta patología constituye un gran problema económico15 para los sistemas de salud debido al alto costo que implica su tratamiento tanto en la fase aguda como su posterior rehabilitación. El tratamiento del TRM se debe iniciar desde el momento en que se sospecha una lesión medular. Con el fin de evitar el daño medular secundario, además de la inmovilización precoz1,2,3,4,5,6,9, 20 se han probado distintos protocolos de tratamientos farmacológicos7,8,10,12,13, sin resultados que avalen su uso. Los protocolos basados en los estudios NASCIS21,22,23,24 utilizados en la actualidad emplean metilprednisolona en dosis de 30 mg/kg en bolo infundido en 15 minutos, seguido de una infusión en dosis de 5.4 mg/kg/hora. Dependiendo si el tiempo transcurrido desde la lesión es menor a 3 horas la infusión se mantiene por 23 horas y si la lesión se encuentra entre 3 y 8 horas se mantiene por 47 horas. Del mismo modo se han utilizado TRH26, Gaciclidina, Naloxona22, Tirilizad24, Nimodipino25 y más recientemente se ha propuesto el tratamiento de células madres27,28. Por otra parte una serie de trabajos11 sugieren que la descompresión y estabilización precoz en TRM disminuye el daño medular así como las complicaciones médicas...
Spinal Cord Injury (SCI) is due to traumatic lesions involving spine, specially spinal cord and its roots. This is a catastrophic neurological disorder for the patients which are usually young people in productive age. The incidente range is from 11.5 to 53.4 per million people. Besides the great social problem it brings another important issue for health systems due to high costs involved. Different pharmacologic protocols have been proposed to avoid a possible further damage, without results supporting their use. Otherwise multiple studies suggest that early spine decompression and stabilization diminish secondary spinal cord damage as well as medical complications and period of hospitalization. Our study retrospectively evaluated a group of patients who received a late decompression and stabilization and one that received an early within the first 72 hours focusing in pre and post surgical stay and associated medical complications. The data were obtained of the Neurosurgical Department of The Rancagua Regional Hospital database and includes 233 patients with spinal cord injury between May 1997 and October 2009. Cervical Spinal Cord Injury is more prevalent and more common in middle age men. Patients who underwent early decompression were hospitalized less time and suffer less medical complications.
Asunto(s)
Humanos , Descompresión Quirúrgica , Fracturas de la Columna Vertebral/cirugía , Chile , Estudios RetrospectivosRESUMEN
BACKGROUND: Community-acquired pneumonia (CAP) severity scores can identify patients at low risk for mortality who may be suitable for ambulatory care. Here, we follow the clinical course of hospitalized patients with CAP due to 2009 H1N1 influenza. OBJECTIVE: To evaluate the role of CAP severity scores as predictors of mortality. METHODS: This was a secondary data analysis of patients hospitalized with CAP due to 2009 H1N1 influenza confirmed by reverse transcriptase polymerase chain reaction enrolled in the CAPO (Community-Acquired Pneumonia Organization) international cohort study. CAP severity scores PSI (Pneumonia Severity Index), CURB-65 (confusion, urea, respiratory rate, blood pressure, age ≥ 65 years) and CRB-65 (confusion, respiratory rate, blood pressure, age ≥ 65 years) were calculated. Actual and predicted mortality rates were compared. A total of 37 predictor variables were evaluated to define those associated with mortality. RESULTS: Data from 250 patients with CAP due to 2009 H1N1 influenza were analyzed. Patients with low predicted mortality rates (0-1.5%) had actual mortality rates ranging from 2.6% to 17.5%. Obesity and wheezing were the only novel variables associated with mortality. CONCLUSIONS: The decision to hospitalize a patient with CAP due to 2009 H1N1 influenza should not be based on current CAP severity scores, as they underestimate mortality rates in a significant number of patients. Patients with obesity or wheezing should be considered at an increased risk for mortality.
Asunto(s)
Infecciones Comunitarias Adquiridas/mortalidad , Subtipo H1N1 del Virus de la Influenza A/aislamiento & purificación , Gripe Humana/mortalidad , Neumonía Viral/mortalidad , Adulto , Anciano , Estudios de Cohortes , Infecciones Comunitarias Adquiridas/fisiopatología , Infecciones Comunitarias Adquiridas/virología , Femenino , Predicción , Hospitalización , Humanos , Gripe Humana/complicaciones , Gripe Humana/fisiopatología , Masculino , Persona de Mediana Edad , Obesidad/complicaciones , Neumonía Viral/fisiopatología , Neumonía Viral/virología , Ruidos Respiratorios/fisiopatología , Factores de Riesgo , Índice de Severidad de la EnfermedadRESUMEN
As the pandemic of 2009 H1N1 influenza A virus progressed, more patients required hospitalisation. The objective of this study is to describe the characteristics and clinical course of hospitalised patients with 2009 H1N1 virus infection in Chile. This was a prospective, observational study of 100 consecutive hospitalised patients with RT-PCR-confirmed 2009 H1N1 influenza A, admitted to Puerto Montt General Hospital (Puerto Montt, Chile). Information was obtained regarding contact history, demographics, laboratory values and clinical course. The primary reason for hospitalisation was pneumonia, in 75% of patients. Rapid influenza A test was positive in 51% of patients. Prior exposure to 2009 H1N1 virus was documented in 21% of patients. Clinical failure, documented in 18% of cases, was characterised by respiratory failure and acute respiratory distress syndrome. Failure was more common in patients with obesity, tachypnoea, confusion and multilobar infiltrates. When evaluating a patient hospitalised with influenza-like illness, a negative rapid test for influenza A or negative contact with a suspected case should not alter physicians' considerations regarding the likelihood of 2009 H1N1 virus infection. Patients with 2009 H1N1 virus infection with obesity, tachypnoea, confusion and multilobar infiltrates should be closely monitored since they are at high risk for clinical failure.
Asunto(s)
Subtipo H1N1 del Virus de la Influenza A/metabolismo , Gripe Humana/epidemiología , Gripe Humana/virología , Adulto , Antibacterianos/farmacología , Antivirales/farmacología , Chile , Femenino , Humanos , Gripe Humana/complicaciones , Masculino , Persona de Mediana Edad , Obesidad/complicaciones , Pandemias , Estudios Prospectivos , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Riesgo , Factores de Tiempo , Resultado del TratamientoRESUMEN
Since 1995 when the first case of hantavirus pulmonary syndrome (HPS) was reported in Patagonia, there have been more than 400 cases of HPS reported in five countries in South America. The first case of HPS was associated with Andes (AND) virus. In this study, we report on the genetic diversity, geographical distribution, and serological features of hantavirus infection in six countries in South America based on 87 HPS cases from Argentina, Bolivia, Chile, Paraguay, and Uruguay. An early immunoglobulin M (IgM), IgA, and IgG humoral response was observed in almost all HPS cases. The IgM response appears to peak 1 or 2 days after the onset of symptoms. Peak IgG antibody titers occur mostly after the first week. Low IgG titers or the absence of IgG was associated with higher mortality rates. The IgA response peaks around day 15 and then rapidly decreases. The results of phylogenetic analysis based on partial M-fragment G1- and G2-encoding sequences showed that HPS cases from the five countries were infected with viruses related to AND or Laguna Negra (LN) virus. Within AND virus-infected persons, at least five major genetic lineages were found; one lineage was detected in Uruguayan and Argentinean cases from both sides of the Rio de la Plata river. Two Paraguayan patients were infected with a virus different from LN virus. According to the results of phylogenetic analyses, this virus probably belongs to a distinct lineage related more closely to the AND virus than to the LN virus, suggesting that there is probably an Oligoryzomys-borne viral variant circulating in Paraguay. These studies may contribute to a better understanding of hantavirus human infection in South America.
Asunto(s)
Anticuerpos Antivirales/sangre , Variación Genética , Virus Hantaan/genética , Virus Hantaan/inmunología , Síndrome Pulmonar por Hantavirus/epidemiología , Adolescente , Adulto , Anciano , Niño , Preescolar , Femenino , Virus Hantaan/aislamiento & purificación , Síndrome Pulmonar por Hantavirus/virología , Humanos , Masculino , Persona de Mediana Edad , Filogenia , América del Sur/epidemiologíaAsunto(s)
Humanos , Masculino , Femenino , /normas , Enfermería , Control de Calidad , Carga de Trabajo/normas , Unidades de Cuidados IntensivosRESUMEN
In March-October 1987 were analyzed 1295 coprological specimens in a sample of the human population who lives in riverside localities in the Valdivia River Basin, Chile. A 23.6% of examined persons presented infection by one or more helminth species. The prevalence of infection by Ascaris lumbricoides, Trichuris trichiura and Trichostrongylidae gen. sp. were 15.5, 12.7 and 0.2%, respectively. The prevalence of human ascariosis and trichuriosis were greater in pre-school and school children. The sex of the host and prevalence of geohelminthosis did not show any relationship. Prevalences of ascariosis and trichuriosis were higher in persons from houses with no sanitary fecal and water disposal. Over 35% and 20.7% of family groups showed infection by A. lumbricoides and T. trichiura, respectively in over 40% of the members of each group. Fecal samples from domestic mammals revealed the following prevalences rates for helminth infections: in dogs 19.0 and 15.2% for Toxocara canis and Uncinaria stenocephala respectively, in cats 65.1% for Toxocara cati, and in pigs 25.4 and 3.2% for Ascaris suum and Trichuris suis respectively. Some of these species are clearly demonstrated agents of zoonoses.
Asunto(s)
Ascariasis/epidemiología , Parasitosis Intestinales/epidemiología , Tricostrongiloidiasis/epidemiología , Tricuriasis/epidemiología , Adolescente , Adulto , Animales , Enfermedades de los Gatos/epidemiología , Gatos , Niño , Preescolar , Chile/epidemiología , Enfermedades de los Perros/epidemiología , Perros , Femenino , Humanos , Lactante , Masculino , Prevalencia , Porcinos , Enfermedades de los Porcinos/epidemiología , Toxocariasis/epidemiologíaRESUMEN
Between March and October 1987, the prevalence of infection by Blastocystis hominis and other intestinal protozoan, their relationship with the age and sex of the hosts, and the percentage of infected persons in family groups were determined in riverside communities of Valdivia River Basin, Chile. One or more intestinal protozoan species were determined in 72.5% of the examined persons. The prevalence was greater for B. hominis (61.8%). The prevalences of B. hominis, Endolimax nana and Entamoeba coli were greater in relation to the age of the host. The sex of the host and prevalence of infections by B. hominis and other species of intestinal protozoans did not show association. Prevalence of B. hominis was greater in persons from houses with no sanitary faeces disposal. Over 60% of the members of family groups showed infection by B. hominis in 53.1% of the groups compared to 2.4%-21.8% of infections by other protozoan species. Faecal samples of 45 pigs revealed 22.2% of infection by Blastocystis.
Asunto(s)
Infecciones por Blastocystis/epidemiología , Blastocystis hominis , Parasitosis Intestinales/epidemiología , Infecciones por Protozoos/epidemiología , Adolescente , Adulto , Distribución por Edad , Animales , Infecciones por Blastocystis/parasitología , Blastocystis hominis/aislamiento & purificación , Niño , Preescolar , Chile/epidemiología , Heces/parasitología , Femenino , Agua Dulce , Humanos , Lactante , Parasitosis Intestinales/parasitología , Masculino , Prevalencia , Infecciones por Protozoos/parasitología , Distribución por SexoRESUMEN
In the Valdivia (Chile) river basin 1,295 inhabitants of 6 riverside districts were examined between March and October 1987 and showed a 1.2% of prevalence by Diphyllobothrium in the districts of Riñihue and Las Huellas. Prevalence of 5.3% and 9.8% respectively were registered in dogs of the districts of Riñihue and Malihue. No cat or pig infection was observed in the different districts. The parasites recovered after the treatment were identified as Diphyllobothrium latum. Human infection by D. latum in the districts affected results from the consumption of smoked or insufficiently cooked fish. The investigation of 1,450 fish (4 exotic species and 11 autochthonous ones), caught in the Valdivia river basin in 1986 and 1987, showed the existence of plerocercoids of D. latum and/or Diphyllobothrium dendriticum in Salmo gairdneri and Salmo trutta among exotic fish and in some autochthonous species. Prevalence and mean intensity in the infection of fish as well as the degree of aggregation in the infrapopulations varied in the different districts. Some species of fish would act as intermediary hosts and others as paratenic hosts in the life cycles of Diphyllobothrium spp. in the Valdivia river basin. An improvement in the conditions of basic sanitation, in sanitary education and in the treatment of infected persons is proposed as a means for the control of diphyllobothriasis in the districts affected.