Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P50583 (asymmetrical)
 12,197 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

It is well known that arginine vasopressin (AVP) produces up to a 40-fold increase (0.1 to 4.0 microL/min.cm2) in net water flux across the amphibian urinary bladder under an osmotic gradient (mucosal side 10% hypotonic). No AVP effect is observed when the gradient is in the opposite direction (serosal hypotonic). Similar asymmetrical behavior to osmotic gradients occurs in the frog corneal epithelium. This rectification phenomenon has not been satisfactorily explained. We measured net water fluxes in bladder sacs and confirmed that AVP has no effect when the serosal bath is hypotonic. We reasoned that the 'abnormal' serosal osmolarity was inducing changes in membrane water permeability, the very parameter being measured. Thus, we studied the effect of solution osmolarity on diffusional water flow (Jdw) across the frog bladder using 3H2O. As expected, AVP doubled Jdw (in either direction from 12 to 21 microL/min.cm2) when the serosal solution was iso-osmolar regardless of mucosal osmolarity. However, in the AVP-stimulated bladders, hypo-osmolarity of the serosal solution reduced Jdw by 42%, an effect that was reversible when normal osmolarity was re-established. Amphotericin B (instead of AVP) was used to irreversibly increase the permeability to water of the apical membrane. Under these conditions, basolateral hypotonicity also reversibly decreased Jdw by 32%, suggesting the basolateral membrane as the site where permeability is reduced. SEM and TEM of the tissue shows extreme swelling when it was exposed to serosal hypotonicity with or without AVP and typical surface morphology changes following hormone stimulation. We conclude that this swelling may initiate a signaling mechanism that reduces basolateral water permeability. These findings constitute evidence of basolateral water channel permeability regulation, which can also contribute to cell volume regulation.
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PMID:Evidence of basolateral water permeability regulation in amphibian urinary bladder. 946 4

Meningitis is a common and life-threatening infection of the central nervous system (CNS) in infants with long-term and disabling sequelae like hydrocephalus. Hydrocephalus is treated by diverting cerebrospinal fluid (CSF) either to another body cavity (via CSF shunt) or externally (via CSF drain) which are prone to infection. Though rare, Candida parapsilosis (C. parapsilosis) is a known pathogen in device-associated CNS infections and has been reported in both, infants and adults. A six-month-old male infant was brought to the hospital with disproportionate head enlargement of three months duration. Magnetic resonance imaging (MRI) was suggestive of gross asymmetrical hydrocephalus. An external ventricular drain (EVD) was placed, and vancomycin and meropenem were started. Four weeks later, he developed a fever with a blocked EVD. Repeat MRI revealed gross asymmetric dilatation of left lateral ventricle along with pneumocephalus in the right periventricular region. A right temporoparietal craniotomy with drainage of a multiloculated abscess was done along with the removal of right EVD and placement of left EVD. CSF showed pan-susceptible C. parapsilosis and fluconazole was started. Despite treatment, CSF continued to grow C. parapsilosis through day 10. The EVD was removed, and an Ommaya reservoir along with the ventricular catheter was placed for better interventricular antibiotic administration. After day 13 CSF became sterile. Ommaya reservoir was removed, fluconazole was continued for three weeks, and a ventriculoperitoneal shunt was placed five weeks later. The device-associated CNS infections are insidious with nonspecific manifestations making diagnosis difficult. C. parapsilosis has been increasing in prevalence, especially in immunocompromised hosts, infants, and in patients with indwelling catheters. Amphotericin B or fluconazole is the usual treatment with excellent outcomes and no mortality. This case underscores the need for suspicion of C. parapsilosis as a cause of device-associated CNS infections.
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PMID:Device-associated Central Nervous System Infection Caused by Candida parapsilosis. 3034 97