RESUMEN
Schwann cells are glial cells that support axonal development, maintenance, defense, and regeneration in the peripheral nervous system. There is limited knowledge regarding the organization, plasticity, and aging of Schwann cells within the dental pulp in adult permanent teeth. The present study sought to relate changes in the pattern of Schwann cell phenotypes between young and old adult teeth with neuronal, immune, and vascular components of the dental pulp. Schwann cells are shown to form a prominent glial network at the dentin-pulp interface, consisting of nonmyelinating and myelinating phenotypes, forming a multicellular neuroimmune interface in association with nerve fibers and dendritic cells. Schwann cell phenotypes are recognized by the expression of S100, glial fibrillary acidic protein (GFAP), myelin basic protein (MBP), Sox10, GAP43, and p75NTR markers. In young adult teeth, a dense population of nonmyelinating Schwann cells projects processes in close association with sensory nerve terminals through the odontoblast layer, reaching the adjacent predentin/dentin domain. While GAP43 and p75NTR are highly expressed in nonmyelinating Schwann cells from young adult teeth, the presence of these markers declines significantly in old adult teeth. Myelinated axons, identified by MBP expression, are mainly present at the Raschkow plexus and within nerve bundles in the dental pulp, but their density is significantly reduced in old adult versus young adult teeth. These data reveal age-related changes within the glial network of the dental pulp, in association with a reduction of coronal dental pulp innervation in old adult versus young adult teeth. The prominence of Schwann cells as a cellular component at the dentin-pulp interface supports the notion that their association with sensory nerve terminals and immune system components forms part of an integrated multicellular barrier for defense against pathogens and dentin repair.
Asunto(s)
Envejecimiento/fisiología , Pulpa Dental/citología , Pulpa Dental/metabolismo , Células de Schwann/citología , Células de Schwann/metabolismo , Adolescente , Adulto , Anciano , Biomarcadores/metabolismo , Femenino , Proteína Ácida Fibrilar de la Glía/metabolismo , Humanos , Masculino , Persona de Mediana Edad , Proteína Básica de Mielina/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Fenotipo , Receptores de Factor de Crecimiento Nervioso/metabolismoRESUMEN
Los Trastornos Temporomandibulares (TTM) son un conjunto de problemas musculares y articulares que afectan al sistema masticatorio. En Chile, hay pocos estudios epidemiológicos en TTM y no se conoce su distribución, severidad, necesidad de tratamiento y comorbilidad. Estas patologías no están incorporadas a las prestaciones de salud oral de las Garantías Explícitas en Salud (GES) y no existen Guías Clínicas Unificadas a nivel nacional para su diagnóstico y derivación desde la Atención Primaria en Salud (APS). El objetivo general de este estudio fue determinar la prevalencia de trastornos temporomandibulares en adultos beneficiarios del Servicio de Salud de Valparaíso y San Antonio (SSVSA). Para lo anterior se propuso un estudio observacional de corte transversal (prevalencia) de TTM, cuya población objetivo correspondió a adultos (mayores de 18 años) beneficiarios del Fondo Nacional de Salud (FONASA) del SSVSA inscritos en consultorios de APS de la comuna de Valparaíso (n= 273.449 según los registros per capita de pacientes válidamente inscritos en 2012). Se examinaron 270 pacientes (168 mujeres, 102 hombres), seleccionados al azar, utilizando las categorías diagnósticas del Research Diagnostic Criteria de Dworkin (Dworkin 1992, adscritas a la Asociación Internacional para la investigación Dental). Los resultados arrojaron una prevalencia de TTM de un 49,6% (al menos un diagnóstico) en la muestra estudiada; y un 19,6% de la población padecía de un TTM severo (dolor muscular y/o articular, asociado a limitación funcional), siendo el sexo femenino el más comprometido (AU)
Temporomandibular Disorders (TMD) are a set of muscle and joint problems affecting the masticatory system. In Chile, there are few epidemiological studies on TMD, and no distribution, severity, and comorbidity need for treatment is known. These conditions are not incorporated into oral health benefits of Explicit Health Guarantees (GES) and there are no clinical guidelines for diagnosis and referral from Primary Health Care (PHC). The overall objective of this study was to determine the prevalence of Temporomandibular Disorders in adults beneficiaries of the Health Service of Valparaiso and San Antonio (SSVSA). For the above observational cross-sectional study (prevalence) TMD, whose target population corresponded to adults (over 18 years) beneficiaries of the National Health Fund (FONASA) of SSVSA enrolled in PHC clinics of the commune of Valparaiso proposed (n= 273,449 according to per capita patients validly registered records in 2012). 270 patients (168 women, 102 men), selected at random, using the diagnostic categories of Research Diagnostic Criteria Dworkin (Dworkin 1992, assigned to the International Association for Dental Research) were examined. The results showed a prevalence of 49.6% TTM (at least one diagnosis) in the sample; and 19.6% of the population suffered from severe TMD (muscle pain and/or joint pain associated with functional limitation), being the most committed female (AU)
Asunto(s)
Humanos , Masculino , Femenino , Adolescente , Adulto , Persona de Mediana Edad , Anciano , Trastornos de la Articulación Temporomandibular/epidemiología , Síndrome de la Disfunción de Articulación Temporomandibular/epidemiología , Distribución por Edad y Sexo , Prevalencia , Comorbilidad , Atención Primaria de Salud/estadística & datos numéricosRESUMEN
Esophageal duplication cysts are a rare medical entity. In most cases they are located at the level of the distal esophagus. Although our case is not unique, we want to focus on it as a reflection on diagnostic methods. The aim of this article is to show through the report on a case of esophageal duplication treated by us, followed by a review of similar cases in the literature, the utility of EUS in the diagnosis of upper-diaphragmatic and not communicating esophageal duplication. We report a case of a 43 year-old woman. She came to our attention for heartburn and retrosternal sense of space. The patient underwent an endoultrasonography (EUS) examination of the esophagus. The framework put EUS diagnosis of cystic formation of the esophagus (esophageal duplication cysts likely). We demonstrate that only EUS has a correlation with the determination of the pre-operative diagnosis with a statistical significance (p <0.001). In the diagnosis of esophageal not communicating duplication cysts EUS is the most specific diagnostic exam.
Asunto(s)
Quiste Esofágico/diagnóstico por imagen , Adulto , Quiste Esofágico/patología , Esofagoscopía/métodos , Femenino , Humanos , Resultado del Tratamiento , UltrasonografíaRESUMEN
The dental pulp in human primary teeth is densely innervated by a plethora of nerve endings at the coronal pulp-dentin interface. This study analyzed how the physiological root resorption (PRR) process affects dental pulp innervation before exfoliation of primary teeth. Forty-four primary canine teeth, classified into 3 defined PRR stages (early, middle, and advanced) were fixed and demineralized. Longitudinal cryosections of each tooth were stained for immunohistochemical and quantitative analysis of dental pulp nerve fibers and associated components with confocal and electron microscopy. During PRR, axonal degeneration was prominent and progressive in a Wallerian-like scheme, comprising nerve fiber bundles and nerve endings within the coronal and root pulp. Neurofilament fragmentation increased significantly during PRR progression and was accompanied by myelin degradation and a progressive loss of myelinated axons. Myelin sheath degradation involved activation of autophagic activity by Schwann cells to remove myelin debris. These cells expressed a sequence of responses comprising dedifferentiation, proliferative activity, GAP-43 overexpression, and Büngner band formation. During the advanced PRR stage, increased immune cell recruitment within the dental pulp and major histocompatibility complex (MHC) class II upregulation by Schwann cells characterized an inflammatory condition associated with the denervation process in preexfoliative primary teeth. The ensuing loss of dental pulp axons is likely to be responsible for the progressive reduction of sensory function of the dental pulp during preexfoliative stages.
Asunto(s)
Pulpa Dental/inervación , Exfoliación Dental/fisiopatología , Diente Primario/inervación , Niño , Diente Canino/patología , Diente Canino/fisiopatología , Pulpa Dental/patología , Pulpa Dental/fisiología , Humanos , Microscopía Confocal , Microscopía Electrónica de Transmisión , Vaina de Mielina/ultraestructura , Degeneración Nerviosa , Fibras Nerviosas/ultraestructura , Resorción Radicular/patología , Resorción Radicular/fisiopatología , Células de Schwann/fisiología , Exfoliación Dental/patología , Diente Primario/patología , Diente Primario/fisiologíaRESUMEN
AIM: This study sought to better understand the relationship between anthropometric profile and maximal strength, as assessed in the sport of powerlifting as relatively little research has examined how differences in anthropometry may contribute to bodyweight-related differences in performance or between more and less successful lifters in the same bodyweight class. METHODS: To address this aim, 63 male powerlifters from an Argentine National Tournament were assessed for 31 anthropometric variables taken using ISAK (International Society for the Advancement of Kinanthropometry) protocols. Body fractionation (adipose, muscle, bone, residual and skin tissue masses) was determined using the validated Kerr & Ross five way fractionation model of body composition that has yet to be used with powerlifters. RESULTS: Results indicated that the powerlifters showed very elevated values of mesomorphy, muscle girths, muscle mass, bone breadths, and all this accompanied by a medium to low stature. Most of these characteristics were more pronounced in the heavier divisions. The winners had significantly larger proportional muscle mass (53.9 ± 2.2%), muscle to bone mass ratio (5.3 ± 1) and crural index (1.21 ± 0.12) than the non-winners. CONCLUSION: These comparisons reveal some potential key anthropometric determinants of high level powerlifting performance. These results further support the view that while powerlifters have unique anthropometric profiles, more successful powerlifters typically have higher degrees of muscle mass expressed per unit height and/or bone mass but similar segment lengths and segment length ratios to their less successful peers.
Asunto(s)
Antropometría/métodos , Rendimiento Atlético/fisiología , Peso Corporal/fisiología , Deportes/fisiología , Levantamiento de Peso/fisiología , Adiposidad/fisiología , Adulto , Índice de Masa Corporal , Estudios Transversales , Humanos , MasculinoRESUMEN
En las últimas décadas se observa un notable incremento de las enfermedades crónicas no trasmisibles asociadas a estilos de vida no saludables, donde la obesidad es en sí misma una enfermedad crónica y a la vez un reconocido factor de riesgo de muchas otras. Los objetivos del presente trabajo son evaluar el valor predictivo del Índice de Masa Corporal (IMC), perímetro de cintura e índice cintura/altura para el desarrollo de hipertensión arterial (HTA), hipercolesterolemia y diabetes tipo 2 (DM2) en una cohorte de empleados públicos hospitalario de Posadas, Misiones, seguidos desde el año 2002 al 2012. La población total estuvo constituida por 989 empleados públicos, de los cuales fueron seleccionados 259 trabajadores que eran normotensos, no hipercolesterolémicos y no diabéticos al inicio del estudio. Se realizaron encuestas personales, mediciones antropométricas, de presión arterial y extracción sanguínea con ayuno de 12 horas. Para el análisis de eventos se utilizó el modelo de riesgos proporcionales de Cox, calculando los correspondientes Hazard Ratio (HR) corregidos por edad y sexo. El IMC predijo de forma significativa la presentación de HTA (HR: 1,100; IC: 1,054-1,148; p < 0,001) y DM2 (HR: 1,253; IC: 1,122-1,40; p < 0,001). El perímetro de cintura se asoció en forma significativa con HTA (HR: 2,273; IC: 1,465-3,826; p<0,001) y DM2 (HR: 5,578; IC: 1,247-24,92; p: 0,024). El índice cintura/altura predijo de forma significativa la presentación de HTA (HR: 2,173; IC: 1,438-3,283; p < 0,001) y DM2 (HR: 5,875; IC: 1,140-30,28; p: 0,034). Ninguno de los indicadores de obesidad evaluados se asoció de forma significativa con la presentación de hipercolesterolemia. Se concluye que el IMC, el perímetro de cintura y el índice cintura/altura predijeron el desarrollo de HTA y diabetes tipo 2. Se resalta así la utilidad de estos indicadores en la vigilancia de las entidades consideradas a través de mediciones antropométricas tradicionales. Rev Argent Endocrinol Metab 51:185-191, 2014 Los autores declaran no poseer conflictos de interés.
In recent decades, a significant increase has been observed in noncommunicable chronic diseases associated with unhealthy lifestyles, with obesity being a chronic disease in itself and at the same time a recognized risk factor for many other conditions. The aim of this study is to assess the predictive value of body mass index (BMI), waist circumference and waist index / height for the development of high blood pressure (hypertension), high cholesterol and type 2 diabetes (DM2) in a cohort of public hospital employees from Posadas, Misiones, who were followed up from 2002 to 2012. Of the total population of 989 public employees, we selected 259 subjects with normal blood pressure, no hypercholesterolemia and no diabetes at baseline. Personal interviews, anthropometric and blood pressure measurements were performed and blood samples were collected after a 12-hour fast. For the event analysis, the Cox proportional hazards model was used, calculating the corresponding Hazard Ratio (HR) adjusted for age and sex. BMI significantly predicted the development of hypertension (HR: 1.100, CI: 1.054 to 1.148, p < 0.001) and DM2 (HR: 1.253, CI: 1.122 to 1.40, P < 0.001). The waist circumference was associated with hypertension (HR: 2.273, CI: 1.465 to 3.826, p < 0.001) and DM2 (HR: 5.578, CI: 1.247 to 24.92, p = 0.024). The waist / height ratio significantly predicted the development of hypertension (HR: 2.173, CI: 1.438 to 3.283, p < 0.001) and DM2 (HR: 5.875, CI: 1.140 to 30.28, p = 0.034). None of the indicators of obesity evaluated was significantly associated with the development of hypercholesterolemia. We conclude that BMI, waist circumference and waist / height ratio predicted the development of hypertension and type 2 diabetes. This underlines the usefulness of these indicators for monitoring the above-referred conditions by traditional anthropometric measurements. Rev Argent Endocrinol Metab 51:185-191, 2014 No financial conflicts of interest exist.
RESUMEN
The quality of harvested rainwater used for toilet flushing in a private house in the south-west of France was assessed over a one-year period. Temperature, pH, conductivity, colour, turbidity, anions, cations, alkalinity, total hardness and total organic carbon were screened using standard analytical techniques. Total flora at 22 °C and 36 °C, total coliforms, Escherichia coli and enterococci were analysed. Overall, the collected rainwater had good physicochemical quality but did not meet the requirements for drinking water. The stored rainwater is characterised by low conductivity, hardness and alkalinity compared to mains water. Three widely used bacterial indicators - total coliforms, E. coli and enterococci - were detected in the majority of samples, indicating microbiological contamination of the water. To elucidate factors affecting the rainwater composition, principal component analysis and cluster analysis were applied to the complete data set of 50 observations. Chemical and microbiological parameters fluctuated during the course of the study, with the highest levels of microbiological contamination observed in roof runoffs collected during the summer. E. coli and enterococci occurred simultaneously, and their presence was linked to precipitation. Runoff quality is also unpredictable because it is sensitive to the weather. Cluster analysis differentiated three clusters: ionic composition, parameters linked with the microbiological load and indicators of faecal contamination. In future surveys, parameters from these three groups will be simultaneously monitored to more accurately characterise roof-collected rainwater.
Asunto(s)
Monitoreo del Ambiente/métodos , Agua Dulce/química , Agua Dulce/microbiología , Vivienda , Lluvia/química , Lluvia/microbiología , Microbiología del Agua , Fenómenos Químicos , Bases de Datos como Asunto , Enterococcus/aislamiento & purificación , Escherichia coli/aislamiento & purificación , Francia , Concentración de Iones de Hidrógeno , Análisis Multivariante , Análisis de Componente Principal , Reciclaje , Estaciones del AñoRESUMEN
Pese a la elevada incidencia de displasia de cadera clínicamente importante (3-5 casos por cada 1000 recién nacidos vivos) y a los ampliamente estudiados factores de riesgo principales (parto de presentación podálica, sexo femenino y antecedentes familiares de displasia evolutiva de cadera), no se ha conseguido encontrar una estrategia efectiva que reduzca la incidencia de casos tardíos. Reabrimos, a propósito de un caso, la controversia existente acerca del cribado ecográfico universal en la patología osteomuscular más frecuente de la infancia (AU)
Despite the elevated incidence of clinically relevant hip dysplasia (3-5 per 1000 live births) and the broadly studied main risk factors (breech position, female sex and family cases), we have not achieved an effective prevention strategy, and so the detection of late cases has not decreased. We reopen, following a case, the existent controversy upon universal ultrasound screening on the most frequent musculo-skeletal disorder in the infancy (AU)
Asunto(s)
Humanos , Masculino , Femenino , Recién Nacido , Luxación Congénita de la Cadera , Tamizaje Masivo/métodos , Factores de Riesgo , Ultrasonografía , Acetábulo/lesiones , Acetábulo/fisiopatología , Osteoartritis/complicaciones , Osteoartritis/diagnósticoRESUMEN
El síndrome de la boca ardiente (SBA) es una entidad nosológica, más frecuente en mujeres menopáusicas. Su principal característica es una sintomatología urente y/o dolorosa de la mucosa bucal (principalmente en la lengua), sin hallazgos clínicos aparentes que expliquen la aparición de esta sensación. Se encuentra relacionado con una serie de factores locales, sistémicos posibles desencadenantes, por lo que se considera de etiología multifactorial. El tratamiento va dirigido a mejorar la sintomatología y controlar los factores. Las terapias propuestas consistentes en control de factores locales, factores sistémicos y psicológicos y algunas indicaciones farmacológicas, proporcionan resultados mediocres. En términos generales, el SBA continúa siendo objeto de estudios en el ámbito de la medicina bucal en busca de un diagnóstico más preciso y de una terapéutica más eficaz (AU)
Burning mouth syndrome (BMS) is a nosological entity, frequent in women in the menopausal period, which principal characteristic is a burning and/or pain sensation of the oral cavity (principally in the tongue). However, the oral mucosa often appears normal, with no apparent organic cause to account for the symptomatology. This syndrome is found to be related which a series of local and systemic factors as possible cause. Therefore is to be considerate a pathology with multifactorial etiology. The treatment is directed to improve the symptomatology and to control the factors. The proposal therapies, related to the control of local, systemic and psychological factors and some pharmacological indications, provide poor results. In general terms the BMS is still the object of many studies in the environment of the oral medicine, in order to search several aspects of diagnose and a more effective therapy (AU)
Asunto(s)
Humanos , Síndrome de Boca Ardiente/epidemiología , Posmenopausia , Glosalgia/etiología , Trastornos Somatomorfos/epidemiología , Síndrome de Boca Ardiente/clasificaciónRESUMEN
The authors report two cases of bezoars. The first was a large gastric bezoar in a patient who had undergone Billroth II gastroresection 40 years earlier. The second was a bezoar located in the distal part of the sigmoid colon accompanied by acute diverticular disease. Both bezoars were removed using endoscopic techniques. The method of exeresis is described together with the characteristics of the different anatomic sites. The authors review the literature focusing on nosology, symptomatology, diagnosis and guidelines for therapy. Considerable attention is paid to the use of endoscopy associated with prokinetic-enzymatic medical therapy. Surgery is reserved for rare cases of endoscopic failure, mostly recorded in the event of trichobezoars following the onset of intestinal occlusions caused by migration, or lastly when the cause of the bezoar is a pre-existing organic or functional stenosis.
RESUMEN
In 10,700 upper gastrointestinal endoscopies performed between 1990 and 1995; one case of gastric haemangioma was observed. The rarity of this tumour, which represents 0.05% of all the digestive neoplasms is underlined and its features and clinical history are reported. This case and the other four reported in Italy during the last fifteen years are critically reviewed. The various diagnostic-therapeutic pictures emerging from literature are examined.
Asunto(s)
Hemorragia Gastrointestinal/etiología , Hemangioma/complicaciones , Pólipos/complicaciones , Neoplasias Gástricas/complicaciones , Anciano , Anciano de 80 o más Años , Femenino , Hemangioma/patología , Humanos , Pólipos/patología , Neoplasias Gástricas/patologíaRESUMEN
BACKGROUND: Personal experience in the treatment of seven pancreatic pseudocysts (four infected and one causing a high intestinal occlusion due to compression on the duodenum) is reported. METHODS: In these emergency situations, which are very risky with the traditional surgical treatments, the percutaneous needle-aspiration with needle of Ciba 22 gauge allowed to overcome the critical phase. RESULTS: In none of the cysts there was a Wirsung's obstruction preventing the defluxion towards the papilla, that's why ductal effraction, being the origin of the pseudocyst, healed spontaneously even if it required many needle-aspiration treatments. CONCLUSIONS: This is the needle-aspiration has been the only approach to the complete elision of the cavity. The methodology used has been described in detail.
Asunto(s)
Biopsia con Aguja/métodos , Seudoquiste Pancreático/patología , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Seudoquiste Pancreático/complicaciones , Seudoquiste Pancreático/diagnóstico por imagen , UltrasonografíaRESUMEN
The authors report two cases of gastric leiomyoblastoma, one benign and one malignant, come to clinical observation for digestive hemorrhage; in both cases a preoperating diagnosis of benignity or malignity was made and in one case even of histotype, thanks to fine needle biopsy. After a short introduction regarding some historical notes, the predictive parameters of malignity, the classification of this rare myoid tumor, the authors discuss the distribution of the pathology in the population, the symptomatology, the diagnostic "iter" with particular regard to the needle biopsy, the surgical treatment, and the indispensable parameters for formulating a correct prognosis.
Asunto(s)
Leiomioma Epitelioide/patología , Neoplasias Gástricas/patología , Adulto , Anciano , Biopsia con Aguja , Gastrectomía , Humanos , Leiomioma Epitelioide/diagnóstico por imagen , Leiomioma Epitelioide/cirugía , Masculino , Estómago/diagnóstico por imagen , Estómago/patología , Neoplasias Gástricas/diagnóstico por imagen , Neoplasias Gástricas/cirugía , UltrasonografíaRESUMEN
The authors report a clinical case of the gallbladder carcinoid tumour treated with laparoscopic cholecystectomy. After a short analysis of the classification, the malignant potentiality and the symptoms of gallbladder carcinoids, they conclude that it is possible to treat carcinoids with laparoscopic cholecystectomy, but only in some selected cases, that is to say in the absence of factors indicative of local invasion and that in the other cases it is preferable the classic surgical treatment of laparotomic resection.
Asunto(s)
Tumor Carcinoide/cirugía , Colecistectomía Laparoscópica/métodos , Neoplasias de la Vesícula Biliar/cirugía , Anciano , Tumor Carcinoide/diagnóstico , Tumor Carcinoide/patología , Colelitiasis/diagnóstico , Colelitiasis/patología , Colelitiasis/cirugía , Femenino , Vesícula Biliar/patología , Neoplasias de la Vesícula Biliar/diagnóstico , Neoplasias de la Vesícula Biliar/patología , Humanos , Grabación en VideoRESUMEN
A clinical entity named 'bovine paraplegic syndrome' ('síndrome parapléjico de los bovinos') has spread alarmingly in the cattle-growing areas of the central and eastern plains of Venezuela. It is estimated that four million cattle are bred in the area where the disease occurs. The mortality ranges from 5 to 25% of the animals at risk, mostly pregnant or lactating cows. The principal characteristic of the bovine paraplegic syndrome is ventral or sternal decubitus, in animals that make vain efforts to stand when stimulated. The diagnosis is established when all other possible causes (e.g. paralytic rabies, botulism and blood parasites such as Anaplasma marginal, Babesia bovis, B. bigemina, and Trypanosoma vivax) have been ruled out clinically and by laboratory tests. Death always occurs, usually after a few days, and there is no known treatment. In this work, we describe results that show the presence of a toxin in the cattle suffering from, or liable to suffer from the syndrome. The toxin is produced by ruminal bacteria. In squid giant axons under voltage clamp conditions, the toxin blocks the sodium current. We detected the toxin analytically by absorbance measurements at 340 nm after reacting with picrylsulfonic acid. We obtained a good separation of the toxin with isocratic high pressure liquid chromatography, using 40% methanol in water on phenylborasil columns.
Asunto(s)
Enfermedades de los Bovinos/fisiopatología , Paraplejía/fisiopatología , Paraplejía/veterinaria , Toxinas Biológicas/análisis , Animales , Axones/efectos de los fármacos , Encéfalo/metabolismo , Bovinos , Enfermedades de los Bovinos/microbiología , Cromatografía Líquida de Alta Presión , Decapodiformes/efectos de los fármacos , Electromiografía , Eritrocitos/efectos de los fármacos , Espacio Extracelular/efectos de los fármacos , Femenino , Técnicas In Vitro , Dosificación Letal Mediana , Masculino , Ratones , Paraplejía/microbiología , Rumen/química , Rumen/microbiología , Ovinos , Canales de Sodio/efectos de los fármacos , Espectrofotometría Ultravioleta , Toxinas Biológicas/química , Toxinas Biológicas/toxicidadRESUMEN
We studied the ruminal population densities of bacteria in animals with and without bovine paraplegic syndrome (BPS). All bacterial counts were performed under strict anaerobiosis. Although the rumen bacterial density was around 10(9) bacteria/ml in animals, both apparently healthy or suffering from BPS, a shift towards Gram-negative strains occurred in animals with BPS. The toxin added to the cultures stimulated bacterial growth. Bacterial strains from the rumen could produce the toxin in vitro. Gram-positive bacteria differed in their ability to produce the toxin; Streptomyces bovis did not produce the toxin, while Lactobacillus vitulinum was an efficient producer. All Gram-negative bacteria tested could produce the compound.