Brain volume regulation in response to changes in osmolality.
ABSTRACT Hypoosmolality and hyperosmolality are relatively common clinical problems. Many different factors contribute to the substantial morbidity and mortality known to occur during states of altered osmotic homeostasis. The brain is particularly vulnerable to disturbances of body fluid osmolality. The most serious complications are associated with pathological changes in brain volume: brain edema during hypoosmolar states and brain dehydration during hyperosmolar states. Studies in animals have elucidated many of the mechanisms involved with brain adaptation to osmotic stresses, and indicate that it is a complex process involving transient changes in water content and sustained changes in electrolyte and organic osmolyte contents. Appreciation of the nature of the adaptation process, and conversely the deadaptation processes that occur after recovery from hypoosmolality and hyperosmolality, enables a better understanding of the marked variations in neurological sequelae that characterize hyperosmolar and hypoosmolar states, and provides a basis for more rational therapies.
Article: Carbimazole embryopathy-bilateral choanal atresia and patent vitello-intestinal duct: a case report and review of literature.[show abstract] [hide abstract]
ABSTRACT: In utero exposure to carbimazole for maternal hyperthyroidism has been reported to cause choanal atresia. There are case reports of patent vitello-intestinal duct and Meckel's diverticulum in similar association. We report another such instance of an infant who was exposed to carbimazole in utero, presenting with bilateral choanal atresia and patent vitello-intestinal duct. As there seems to be no reports of a possible association between propylthiouracil and congenital malformations, it may be safer to use propylthiouracil instead of carbimazole.Birth Defects Research Part A Clinical and Molecular Teratology 08/2008; 82(9):649-51. · 2.27 Impact Factor
Article: Effect of osmolarity on CSF volume during ventriculo-aqueductal and ventriculo-cisternal perfusions in cats.[show abstract] [hide abstract]
ABSTRACT: The effect of cerebrospinal fluid (CSF) osmolarity on the CSF volume has been studied on different CSF/brain tissue contact areas. It has been shown, on anesthetized cats under normal CSF pressure, that the perfusion of CSF system (12.96 μl/min) by hyperosmolar CSF (400 mOsml/l) leads to significantly higher outflow volume (μl/min) during ventriculo-cisternal perfusion (29.36 ± 1.17 and 33.50 ± 2.78) than the ventriculo-aqueductal perfusion (19.58 ± 1.57 and 22.10 ± 2.31) in experimental period of 30 or 60 min. Both of these hyperosmolar perfusions resulted in significantly higher outflow volume than the perfusions by isoosmolar artificial CSF (12.86 ± 0.96 and 13.58 ± 1.64). These results suggest that the volume of the CSF depends on both the CSF osmolarity and the size of the contact area between CSF system and surrounding tissue exposed to hyperosmolar CSF. However, all of these facts imply that the control of the CSF volume is not in accordance with the classical hypothesis of cerebrospinal fluid hydrodynamic. According to this hypothesis, the CSF volume should be regulated by active formation of CSF (secretion) inside the brain ventricles and passive CSF absorption outside of the brain. Obtained results correspond to the new hypothesis which claims that the volume of CSF depends on the gradients of hydrostatic and osmotic forces between the blood on one side and extracellular fluid and CSF on the other. The CSF exchange between the entire CSF system and the surrounding tissue should, therefore, be determined by (patho)physiological conditions that predominate within those compartments.Neuroscience Letters 10/2010; 484(2):93-7. · 2.11 Impact Factor
Article: Appropriate fluid for intravenous maintenance therapy in hospitalized children--current status.The Indian Journal of Pediatrics 10/2010; 78(3):357-9. · 0.52 Impact Factor