Search results for "ISM [radio lines]"
showing 10 items of 1018 documents
The tumour-inhibiting potential of the progesterone antagonist Onapristone in the human mammary carcinoma T61 in nude mice
1992
The progesterone antagonist Onapristone proved to possess strong tumour-inhibiting activity in a panel of experimental mammary carcinomas. Its underlying mechanism of action is due to a progesterone-receptor-mediated induction of terminal differentiation and a specific blockade of the cell cycle and is also present in the absence of progesterone as was shown in the MXT mammary tumour. To prove this further, the tumour-inhibiting activity of Onapristone was investigated in the human postmenopausal T61 mammary tumour implanted in castrated male nude mice. Whereas Onapristone given alone had no effect on growth of established tumours, after stimulation of the relatively low progesterone recept…
Noradrenaline release from permeabilized synaptosomes is inhibited by the light chain of tetanus toxin
1992
AbstractNoradrenaline release from rat brain cortical synaptosomes permeabilized with streptolysin O can be triggered by μM concentrations of free Ca2+. This process was inhibited within minutes by tetanus toxin and its isolated light chain, but not by its heavy chain. The data demonstrate that the effect of tetanus toxin on NA release from purified synaptosomes is caused by the intraterminal action of its light chain.
Memory-Based Mismatch Response to Frequency Changes in Rats
2011
Any occasional changes in the acoustic environment are of potential importance for survival. In humans, the preattentive detection of such changes generates the mismatch negativity (MMN) component of event-related brain potentials. MMN is elicited to rare changes (‘deviants’) in a series of otherwise regularly repeating stimuli (‘standards’). Deviant stimuli are detected on the basis of a neural comparison process between the input from the current stimulus and the sensory memory trace of the standard stimuli. It is, however, unclear to what extent animals show a similar comparison process in response to auditory changes. To resolve this issue, epidural potentials were recorded above the pr…
Effects of Propofol on H-reflex in Humans
2001
Background Depression of spinal cord motoneuron excitability has been proposed to contribute to surgical immobility. The H-reflex, which measures alpha-motoneuron excitability, is depressed by volatile anesthetics, whereas the action of propofol is unknown. The objective of this study was to determine the effects of propofol anesthesia on the H-reflex. Methods In 13 patients (group 1), H-reflex was measured before (T0), 3 min after (T1), and 10 min after (T2) a 2-mg/kg bolus dose of propofol, followed by an infusion of 10 mg x kg(-1) x h(-1). Ten patients (group 2) were studied when propofol was given via a programmable pump set to a propofol blood concentration of 6 microg/ml, and 10 pati…
Interaction of uridine with GABA binding sites in cerebellar membranes of the rat
1983
The effect of uridine, a postulated anticonvulsant agent, on GABA receptors has been investigated. Uridine inhibits [3H]GABA binding to rat cerebellar buffer-washed membranes. Pretreatment of the membranes with Triton X-100 increases the effect of uridine on GABA-binding. The Scatchard analysis reveals that both high and low affinities of GABA for its receptors are affected by 1 mM uridine, while the apparent number of binding sites remains unchanged. The ability of uridine to interact competitively with GABA binding sites, also examined by the Lineweaver-Burk analysis, suggests a possible mechanism of action of this anticonvulsant agent, so including it among those compounds characterized …
Local Cerebral Blood Flow in a Rat Cortical Vein Occlusion Model
1996
The symptoms following sinus and vein occlusion observed in patients and experimental animals display a considerable variability that so far remains largely unexplained. In a rat cortical vein occlusion model using a photochemical thrombotic technique, we examined changes in the cerebral venous flow pattern by fluorescence angiography and regional cerebral blood flow (rCBF) and cerebral blood volume fraction (CBVF) by a modern laser Doppler “scanning” technique. Brain damage was assessed histologically. Fluorescence angiographic findings fell into two groups: group A, rats with an altered venous flow pattern after occlusion (n = 12), and group B, rats with interruption of blood flow and/or…
On the mechanism of action of phenylephrine in rat atrial heart muscle
1994
Both in rat left atrial heart and in aortic smooth muscle preparations, phenylephrine (PE) caused a concentration-dependent increase in force of contraction (FC) in the presence of atenolol (10 mumol/l), which was antagonized by phentolamine, prazosin and WB 4101 in a competitive manner. The pA2 values of the antagonists in the cardiac tissue were 10-20fold lower than those in the rat thoracic aorta. In the spontaneously beating right atrium, PE exerted a positive chronotropic action, which was not significantly antagonized by phentolamine or prazosin. It is therefore assumed that the effects of phenylephrine in the left atrium and in the aorta are mediated by different subtypes of alpha 1-…
Calcium antagonist properties of cinnarizine, trifluoperazine and verapamil in guinea-pig normal and skinned trachealis muscle.
1990
In guinea-pig trachealis, depolarized by a K(+)-rich medium, Ca2+ (0.01-10 mM) caused concentration-related spasm. Verapamil (0.5-5 microM), cinnarizine (10-100 microM) and trifluoperazine (16-160 microM) each produced concentration-dependent antagonism of Ca2+ characterized by a rightward and downward displacement of the log concentration-effect curve for Ca2+. The rank order of potencies of these antagonists, measured as the IC75 against Ca2+ (10 mM)-induced contraction of depolarized trachea, was verapamil (5.6 microM) greater than cinnarizine (59 microM) greater than trifluoperazine (91 microM). In skinned trachea, verapamil in concentrations up to 100 microM did not modify the concentr…
Spasmolytic Effects of Aphanizomenon Flos Aquae (AFA) Extract on the Human Colon Contractility.
2021
The blue-green algae Aphanizomenon flos aquae (AFA), rich in beneficial nutrients, exerts various beneficial effects, acting in different organs including the gut. Klamin® is an AFA extract particularly rich in β-PEA, a trace-amine considered a neuromodulator in the central nervous system. To date, it is not clear if β-PEA exerts a role in the enteric nervous system. The aims of the present study were to investigate the effects induced by Klamin® on the human distal colon mechanical activity, to analyze the mechanism of action, and to verify a β-PEA involvement. The organ bath technique, RT-PCR, and immunohistochemistry (IHC) were used. Klamin® reduced, in a concentration-dependent manner, …
Cluster of cases of Salmonella enterica serotype Rissen infection in a general hospital, Italy, 2007.
2009
In 2007, three strains of Salmonella enterica serotype Rissen (S. Rissen) were isolated in the laboratory of diagnostic microbiology of the General Hospital of Prato, Tuscany, Italy, over a 1 month and half interval of time. The first isolate was recovered on January 26 from an outpatient with enteritis. Then, two strains were isolated on February 16 and March 11 respectively, from central venous catheters of patients who were being hospitalized in two departments of the Hospital. An epidemiologically linked cluster of cases of salmonellosis was suspected. The three strains were submitted to single enzyme-amplified fragment length polymorphism (SE-AFLP) and XbaI macrorestriction and pulsed-…