Search results for "Calcium"
showing 10 items of 1740 documents
Modified cryopreservation and xenotransplantation of human parathyroid tissue.
1999
Introduction: A modified cryopreservation technique for human parathyroid tissue was compared with the standard method using a programmed freezer. Methods: Total parathyroidectomy was performed in three groups of 6-week-old Rowett nude rats. Group I (control) underwent no transplantation of parathyroid tissue (n=9). After 10 days, the rats of groups II (n=15) and III (n=15) underwent xenotransplantation of 20 mg cryopreserved human parathyroid tissue, which had been stored in liquid nitrogen at –196°C for 1–22 months prior to xenotransplantation. The parathyroid tissue was derived from 15 parathyroidectomized patients with renal hyperparathyroidism. Two tissue samples were obtained from eve…
MECHANISMS OF TENSION DEVELOPMENT INDUCED BY MONENSIN IN GUINEA-PIG AORTA : EFFECTS OF VERAPAMIL, OUABAIN, PRAZOSIN AND GLIBENCLAMIDE
1993
The influence of monensin (10 µmol/L) alone and in the presence of verapamil (3 µmol/L) or ouabain (1 mmol) and prazosin (1 µmol/L) or glibenclamide (10 µmol/L) were studied on the muscle tension of guinea pig aorta. Changes in tissue sodium, potassium and calcium ion contents of the aortic muscle produced by monensin in the presence of prazosin were evaluated. Monensin in normal Tyrode's solution containing prazosin caused an increase in the resting tension followed by a decrease and returned to normal values. Verapamil reduced the muscle tension induced by monensin. After ouabain, monensin induced sustained increase in the resting tension. Glibenclamide partially reversed the relaxant pha…
Acute oral administration of low doses of methylphenidate targets calretinin neurons in the rat septal area.
2015
Methylphenidate (MPD) is a commonly administered drug to treat children suffering from attention deficit hyperactivity disorder (ADHD). Alterations in septal driven hippocampal theta rhythm may underlie attention deficits observed in these patients. Amongst others, the septo-hippocampal connections have long been acknowledged to be important in preserving hippocampal function. Thus, we wanted to ascertain if methylphenidate administration, which improves attention in patients, could affect septal areas connecting with hippocampus. We used low and orally administered methylphenidate doses (1.3; 2.7 and 5mg/Kg) to rats what mimics the dosage range in humans. In our model, we observed no effec…
Influence of the calcium antagonist amlodipine on left ventricular mass and function in patients with essential hypertension
1997
This study was conducted to evaluate the influence of antihypertensive treatment with the calcium antagonist amlodipine on left ventricular structure and systolic and diastolic function in patients with essential hypertension.
A clinical study of the effect of calcium sodium phosphosilicate on dentin hypersensitivity
2012
Objective: Dentinal hypersensitivity is a commonly encountered problem with varied treatment options for its management. A large number of home use products have been tested and used for the management of dentinal hypersensitivity. This 8 week clinical trial investigates the temporal efficacy of commercially available calcium sodium phosphosilicate containing toothpaste in comparison to a potassium nitrate containing toothpaste. Methods: A total 20 subjects between the ages of 18 to 65 years were screened for a visual analogue score (VAS) for sensitivity of 5 or more by testing with a cold stimulus and randomly divided into test and positive control groups. Baseline sensitivity VAS scores t…
Myogenic effects enhance norepinephrine constriction: Inhibition by nitric oxide and felodipine
1998
Myogenic effects enhance norepinephrine constriction: Inhibition by nitric oxide and felodipine. Myogenic, pressure-induced vasoconstriction may amplify the effects of circulating vasoconstrictors. Through intravital microscopy in cremaster arterioles (31 to 115 μm diameter), the relative contribution of myogenic responses (MR) to norepinephrine (NE)-induced constriction and the inhibitor potency of nitric oxide (NO) or a Ca2+ entry blocker (CEB), felodipine (F), were examined. In 24 anesthetized hamsters, a vessel occluder was placed around the aorta to control cremaster vessel inflow pressure (IP). NE infusion increased blood pressure (by 50 ± 2mm Hg) and induced significant constriction …
Endothelin action on goat cerebral arteries.
1990
Abstract Cumulative application of endothelin-1 (human) markedly constricted goat isolated cerebral arteries in a concentration-dependent manner. Contractile responses were not affected by removal of endothelial cells. Removal of extracellular calcium or addition of the calcium channel blocker nicardipine (10−7 M) failed to abolish responses to endothelin. The results suggest that the endothelium-independent constriction of cerebral arteries produced by endothelin cannot be explained solely by voltage-dependent calcium channels. The contractile responses are likely to be mediated by stimulation of specific receptors for this peptide.
Increased 2-Hydroxylation of Estrogen in Women with a Family History of Osteoporosis
2005
Recent studies indicate that women with predominant estrogen metabolism through the 2-hydroxyl (inactive) pathway have lower bone mineral density (BMD) compared with those with predominant 16alpha-hydroxylation (active). Although many factors have been identified to affect estrogen metabolism, the role of a family history of osteoporosis remains unknown. The objective of this study was to investigate the influence of family history of osteoporosis and other clinical factors on estrogen hydroxylation. This was a cross-sectional study conducted in a university-based research center from May 2002 to February 2004. The participants included 175 otherwise healthy postmenopausal women at least 1 …
Bafetinib inhibits functional responses of human eosinophils in vitro
2012
Eosinophils play a prominent role in the process of allergic inflammation. Non-receptor associated Lyn tyrosine kinases generate key initial signals in eosinophils. Bafetinib, a specific Abl/Lyn tyrosine kinase inhibitor has shown a potent antiproliferative activity in leukemic cells, but its effects on eosinophils have not been reported. Therefore, we studied the effects of bafetinib on functional and mechanistic responses of isolated human eosinophils. Bafetinib was more potent than non-specific tyrosin kinase comparators genistein and tyrphostin inhibiting superoxide anion triggered by N-formyl-Met-Leu-Phe (fMLF; 100 nM) (−log IC50=7.25±0.04 M; 6.1±0.04 M; and 6.55±0.03 M, respectively).…
Alteration of the Calcium Content in Inner Hair Cells of the Cochlea of the Guinea Pig after Acute Noise Trauma with and without Application of the O…
1999
Calcium ions are known to be important to the process of signal transduction across the apical and basal sides of the inner hair cells. Calcium channel antagonists have been demonstrated by light microscopy to provide protection against acoustic trauma. To evaluate the protective effect of calcium channel blocker on the inner ear cells to noise exposure, the amount of the histochemical reaction products formed in the cytoplasm of the inner hair cells of the guinea pig after application of pyroantimonate was measured by an image processing system connected to an energy-filtering transmission electron microscope (EFTEM). Compared to untreated control specimens (experimental animal group I) th…