RESUMEN
Sympathetic nerve activity to the cardiovascular system displays prominent respiratory-related modulation which leads to the generation of rhythmic oscillations in blood pressure called Traube-Hering waves. An amplification of this respiratory modulation of sympathetic activity is observed in hypertension of both genetic, the spontaneously hypertensive rat, and induced, chronic intermittent hypoxia or maternal protein restriction during gestation, origin. Male offspring of mothers with uteroplacental insufficiency, induced by bilateral uterine vessel ligation at 18 days of gestation, are also hypertensive in adulthood. In this study we examined whether these male offspring display altered respiratory modulation of sympathetic activity at pre-hypertensive ages compared to controls. Respiratory, cardiovascular and sympathetic parameters were examined using the working heart-brainstem preparation in 35 day old male rats that had reduced birth weight due to uteroplacental insufficiency. Whilst all respiratory parameters were not different between groups, we observed an enhanced respiratory-related burst of thoracic sympathetic nerve activity and amplified Traube-Hering waves in the growth-restricted group. This group also showed an increased sympathetic and bradycardic response to activation of peripheral chemoreceptors. The observations add support to the view that altered respiratory modulation of sympathetic activity represents a common mechanism involved in the development of several forms of hypertension.
Asunto(s)
Hipoxia Fetal/fisiopatología , Trastornos Nutricionales en el Feto/fisiopatología , Respiración , Sistema Nervioso Simpático/fisiopatología , Animales , Bradicardia/fisiopatología , Tronco Encefálico/fisiopatología , Células Quimiorreceptoras/fisiología , Modelos Animales de Enfermedad , Corazón/fisiopatología , Hipertensión/fisiopatología , Masculino , Distribución Aleatoria , Ratas , Ratas Endogámicas WKY , Transmisión Sináptica , Técnicas de Cultivo de TejidosRESUMEN
Rett syndrome is a neurodevelopmental disease accompanied by complex, disabling symptoms, including breathing symptoms. Because Rett syndrome is caused by mutations in the transcriptional repressor methyl-CpG-binding protein 2 (MeCP2), Mecp2-deficient mice have been generated as experimental model. Males of Mecp2-deficient mice (Mecp2(-/y)) breathe normally at birth but show abnormal respiratory responses to hypoxia and hypercapnia from postnatal day 25 (P25). After P30, Mecp2(-/y) mice develop breathing symptoms reminiscent of Rett syndrome, aggravating until premature death at around P60. Using plethysmography, we analyzed the sighs and the post-sigh breathing pattern of unrestrained wild type male mice (WT) and Mecp2(-/y) mice from P15 to P60. Sighs are spontaneous large inspirations known to prevent lung atelectasis and to improve alveolar oxygenation. However, Mecp2(-/y) mice show early abnormalities of post-sigh breathing, with long-lasting post-sigh apnoeas, reduced tidal volume when eupnoea resumes and lack of post-sigh bradypnoea which develop from P15, aggravate with age and possibly contribute to breathing symptoms to come.
Asunto(s)
Hipercalcemia/complicaciones , Hipoxia/complicaciones , Proteína 2 de Unión a Metil-CpG/deficiencia , Anomalías del Sistema Respiratorio/fisiopatología , Síndrome de Rett/fisiopatología , Factores de Edad , Animales , Animales Recién Nacidos , Apnea/genética , Apnea/fisiopatología , Modelos Animales de Enfermedad , Hipercalcemia/genética , Hipoxia/genética , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Pletismografía , Respiración/genética , Mecánica Respiratoria/genética , Anomalías del Sistema Respiratorio/genética , Síndrome de Rett/genética , Volumen de Ventilación Pulmonar/genéticaRESUMEN
The authors report the case of a 15-year-old female suffering from bilateral keratitis revealing Lyme's disease, 6 years after a tick bite. The corneas disclosed multiple hazy infiltrates adjacent to the limbus and in the midperiphery, from the superficial layers to pre-Descemet's membrane. The other systems involved were the joints, the skin (an atypical erythema chronicum migrans), and perhaps the peripheral nerves. The diagnosis was confirmed by indirect immunofluorescence assays in the serum of the patient who completely and rapidly healed with amoxicillin and systemic and topical steroids. The clinical and serological pitfalls which explain the frequent delayed diagnosis of Lyme's disease, its complications, especially ocular, and the therapeutic strategies are discussed.
Asunto(s)
Queratitis/etiología , Enfermedad de Lyme/complicaciones , Adolescente , Femenino , Humanos , Enfermedad de Lyme/diagnóstico , Enfermedad de Lyme/fisiopatología , Factores de TiempoRESUMEN
In this work, the authors pointed out that the perturbation of connection between parents and children was the primary factor of squint in 10% in cases. They proved it with two examples.