Search results for " calcium"
showing 10 items of 342 documents
Mechanisms underlying noise-induced hearing loss
2006
Noise-induced hearing loss (NIHL) is the worldwide leading occupational disease and presents an important socio-economic factor. Despite numerous identified details about its etiology, the underlying mechanisms, which induce NIHL, have been only partially identified. In the present article, we shall discuss possible mechanisms focusing on failure in cellular calcium regulation, leading to a rise in mitochondrial NO production and reactive oxygen species formation. In cases where radical production is significantly elevated, pathological concentrations lead to alterations of cell physiological conditions and finally contribute to NIHL. A more detailed knowledge about the induction of free ra…
Hypercalciuria and kidney calcifications in terminal 4q deletion syndrome: Further evidence for a putative gene on 4q
2003
We report a newborn girl with a de novo terminal 4q deletion (q31.3 → qter) and a characteristic phenotype of minor facial anomalies, cleft palate, congenital heart defect, abnormalities of hands and feet, and postnatal onset of growth deficiency. Laboratory studies showed excessive urinary calcium excretion on standard milk formula and on oral calcium load. Blood measurements of parathyroid hormone, calcitonin, bicarbonate, calcium, phosphorus, magnesium, sodium, chlorine, potassium, and urinary measurements of phosphorus, magnesium, sodium, chlorine, potassium were normal for age. At 2 months of life, ultrasonography showed kidney calcifications. Clinical and laboratory data support the d…
Surgical sphincter saving approach and topical nifedipine for chronic anal fissure with hypertonic internal anal sphincter
2020
PURPOSE The role of augmented internal anal sphincter (IAS) tone in the genesis of posterior chronic anal fissure (CAPF) is still unknown. Lateral internal sphincterotomy is the most employed surgical procedure, nevertheless it is burdened by high risk post-operative anal incontinence. The aim of our study is to evaluate results of sphincter saving procedure with post-operative pharmacological sphincterotomy for patients affected by CAPF with IAS hypertonia. Methods: We enrolled 30 patients, undergone fissurectomy and anoplasty with V-Y cutaneous flap advancement; all patients received topical administration of nifedipine 0.3% and lidocaine 1.5% ointment-based therapy before and for 15 days…
Use of Zoledronic Acid in a Neonate with Subcutaneous Fat Necrosis Complicated with Severe, Refractory Hypercalcemia.
2019
Objective Subcutaneous fat necrosis (SCFN) is a rare condition that may occur in the neonatal period. SCFN is an inflammatory disorder of the adipose tissue, usually found in full-term healthy infants who have a history of intrauterine or perinatal distress. It is usually a self-limited condition; however, in some cases, it can get complicated, leading to severe hypercalcemia that may be life-threatening. Study Design We report and describe a classic presentation of SCFN that led to severe hypercalcemia refractory to standard treatment. The diagnosis of SCFN was made based on the finding of subcutaneous nodules and of hypercalcemia. The serum calcium level reached 16.6 mg/dL. Hypercalcemia…
The influence of Ca2+ antagonists on the ciliary activity of the guinea pig trachea.
1990
The ciliary activity of the guinea pig tracheal respiratory epithelium was measured using a photoelectric device. Fourteen animals were administered 75 mg diltiazem/kg body weight 2 days, 1 day and 4 h prior to the investigation. Thirteen animals served as controls. In the pretreated group, the mean ciliary stroke frequency (13.4 +/- 3.0 Hz) was significantly lower (P = 0.02) than in the control group (16.6 +/- 3.7 Hz). The application of aerosolized 0.3 mmol/l nifedipine solution on the tracheal preparations of the control animals also significantly reduced the stroke frequency (P = 0.02). The ciliary activity never dropped beyond a frequency of about 8 Hz. The most probable interpretation…
Differential blockade by nifedipine and ω-conotoxin GVIA of α1- and β1-adrenoceptor-controlled calcium channels on motor nerve terminals of the rat
1990
Electrically evoked release of [3H]acetylcholine ([3H]ACh) from the rat phrenic nerve and its facilitation by stimulation of presynaptic alpha 1- and beta 1-adrenoceptors were investigated in the absence and presence of nifedipine and omega-conotoxin GVIA. Both calcium channel antagonists did not modify electrically evoked [3H]ACh release, but selectively blocked the effect triggered by both facilitatory adrenergic receptors. The increase in [3H]ACh release mediated via beta 1-adrenoceptor activation was abolished by low concentrations (1 nM) of omega-conotoxin GVIA, whereas nifedipine (100 nM) abolished the facilitatory effect mediated via alpha 1-adrenoceptor stimulation. Therefore, the b…
NADPH Oxidase Accounts for Enhanced Superoxide Production and Impaired Endothelium-Dependent Smooth Muscle Relaxation in BKβ1 −/− Mice
2006
Objective— Nitric oxide (NO)-induced vasorelaxation involves activation of large conductance Ca 2+ -activated K + channels (BK). A regulatory BKβ1 subunit confers Ca 2+ , voltage, and NO/cGMP sensitivity to the BK channel. We investigated whether endothelial function and NO/cGMP signaling is affected by a deletion of the β1-subunit. Methods and Results— Vascular superoxide in BKβ1 −/− was measured using the fluorescent dye hydroethidine and lucigenin-enhanced chemiluminescence. Vascular NO formation was analyzed using electron paramagnetic resonance (EPR), expression of NADPH oxidase subunits, the endothelial NO synthase (eNOS), the soluble guanylyl cyclase (sGC), as well as the activity a…
Other Methods to Assess Renal Damage
2015
Although glomerular filtration rate (GFR) and proteinuria remain gold standard in the evaluation of renal target organ damage, imaging techniques and image-derived parameters allow for both assessment of renal function and estimation of cardiovascular risk. Enhancement in digital image processing permits dynamic measurement of renal vascular and intraparenchymal processes in real time. The most relevant in terms of clinical use to assess hypertension-induced organ damage are the renal resistive index (RRI), renal calcium score, and functional magnetic resonance imaging.
Combined sub-optimal doses of Rosuvastatin and Bexarotene impairs angiotensin II-induced arterial mononuclear cell adhesion through inhibition of Nox…
2015
Aim: Mononuclear cell (MC) infiltration into the arterial subendothelium is a key event in atherogenesis. Rosuvastatin (Rosu) and bexarotene (Bex) exert anti-inflammatory activity, but serious dose-related adverse effects have emerged. The need for safer and effective strategies to prevent and treat atherosclerosis led us to test the effect of combined use of both drugs on angiotensin II (Ang-II)-induced arterial MC recruitment. Results: Vehicle, Rosu (10–30 nM), Bex (0.3–1 μM), or a combination of both were administered to human umbilical arterial endothelial cells (HUAECs) 20 h before stimulation with 1 μM Ang-II (4 h). Surprisingly, a combination of Rosu (10 nM)+Bex (0.3 μM), which did n…
Vascular effects of progesterone: Role of cellular calcium regulation
2001
Abstract —Vascular actions of progesterone have been reported, independently of estrogen, affecting both blood pressure and other aspects of the cardiovascular system. To study possible mechanisms underlying these effects, we examined the effects of P in vivo in intact rats and in vitro in isolated artery and vascular smooth muscle cell preparations. In anesthetized Sprague-Dawley rats , bolus intravenous injections of P (100 μg/kg) significantly decreased pressor responses to norepinephrine (0.3 μg/kg). In vitro, progesterone (10 −8 to 10 −5 mmol/L) produced a significant, dose-dependent relaxation of isolated helical strips, both of rat tail artery precontracted with KCl (60 mmol/L) or a…