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Biomedical subjects

A Galli

Publications and source records attributed to A Galli.

At least 199 records · Page 11Linked to original sources
PubMed1984

Genetic and biochemical investigation on chloral hydrate in vitro and in vivo.

Chloral hydrate (CH), a metabolite of trichloroethylene (TCE), was studied in vitro using the D7 diploid strain of Saccharomyces cerevisiae, with and without a mammalian microsomal activation system (S9 fraction), and in vivo by intrasanguineous host-mediated assay (HMA). The in vivo effects on the hepatic microsomal monooxygenase induced by CH in mice pretreated with beta-naphthoflavone (beta-NF) and Naphenobarbital (PB) were also investigated. Chloral hydrate induced a significant increase of mitotic gene conversion in D7 strain both in vivo and in vitro. The enzymatic determinations in mice showed a decrease in aminopyrine N-demethylase (APD) and p-nitroanisole O-demethylase (p-NAD) activities (about 37% and 29% respectively) after one acute dose of CH. Moreover, stability experiments, carried out in the conditions of the liver microsomal assay (LMA), showed an increase of residual activity, after 1 h of preincubation with respect to the control (about 22% and 9% for APD and p-NAD respectively).

Aminopyrine N-Demethylase↗
PubMed1984

Relationships between diaphragmatic hiatus and infra-diaphragmatic esophagus: a combined X-ray and manometry study.

The relationship between the diaphragmatic hiatus, the infra-diaphragmatic esophagus and a manometric tube were examined in 10 patients not suffering from hiatal hernia or gastroesophageal reflux. During surgery, two metal markers were attached to the diaphragmatic hiatus and two others were fixed at the vertex of the angle of His. X-ray examinations were taken during manometric recordings of the high pressure zone (HPZ) both at rest and during relaxation. Comparison between the radiographs showed that during swallowing the manometric tube did not move with respect to the vertebral bodies; contraction of the esophagus caused complete disappearance of the infra-diaphragmatic esophagus. It was also observed that during pressure drop in the HPZ (so-called lower esophageal sphincter relaxation), the manometric recording site is located below the vertex of the angle of His, i.e. in the gastric cavity. These findings provide the basis for a hypothesis to explain the passage of a solid bolus through the lower esophagus into the stomach.

Adult↗
PubMed1983

Evidence of enrichment in glycine receptors of crude synaptic membranes from rat spinal cord following Triton X-100 treatment.

Treatment of synaptic membranes from rat brainstem and spinal cord with the nonionic detergent Triton X-100 at 1-10 microliters/mg protein caused a marked increase in glycine receptor (3H)strychnine binding expressed per mg of residual membrane protein. The effect was maximal (220 +/- 6% of control) at 5 microliters Triton/mg protein, while higher concentrations caused progressive loss of strychnine binding ability of membranes (27 +/- 6% at 25 microliters Triton/mg protein). The increase in strychnine binding caused by low Triton X-100 reflected an increase in membrane Bmax, the kD being unaffected by the treatment. The affinity of glycine analogues for receptor sites was not appreciably affected by the detergent either. The findings suggest an enrichment of the synaptic membrane preparation in glycine receptors, caused by the solubilization by Triton of membrane constituents not related to the receptor sites.

Animals↗
PubMed1983

Genetic and biochemical studies on perchloroethylene 'in vitro' and 'in vivo'.

Perchloroethylene (PCE) was tested in a diploid strain (D7) of the yeast Saccharomyces cerevisiae in suspension tests with and without a mammalian microsomal activation system (S9) and 'in vivo' by the intrasanguineous host-mediated assay. In addition, enzyme alteration studies were performed in mice non-pretreated or pretreated with phenobarbital + beta-naphthoflavone. PCE did not induce any genetic effect either 'in vitro' or 'in vivo'. In the suspension test, PCE was more toxic without metabolic activation and less toxic with mammalian microsomal activation. The enzymatic determinations showed an increase of the aminopyrine demethylase activity and of the level of cytochrome P-450.

Aminopyrine N-Demethylase↗
PubMed1983

Study of carbohydrate material isolated from ultrafiltrates in patients with chronic renal failure.

We have isolated substances of molecular weight ranging between 350 and 2,000 daltons from ultrafiltrates of 3 patients treated by maintenance haemodialysis for chronic renal failure. Such substances might have a role in the genesis of uraemic toxicity. We have chiefly studied their carbohydrate content. Material was fractionated according to a procedure previously used to urine in healthy controls. Consecutive ion exchange, charcoal Celite and paper chromatography lead to the isolation and purification of oligosaccharides, glycopeptides, glucuronoconjugates and peptides. The different classes of carbohydrate material present in dialysis fluids from uraemic patients are close to those formed in normal urines. All the oligosaccharides in renal failure urine had have identified in normal urine. In a previous studies we have demonstrated that the levels of glucuronoconjugates are higher in the blood of uraemic patients. The glucuronoconjugates and their aglycones could have a toxic effect but a great part of them is removed by hemodialysis.

Carbohydrates↗
PubMed1983

[Copper, zinc and aluminum contamination of blood specimens used for determination of these metals].

Increasing interest and demand in determinations of copper, zinc and aluminium in clinical biochemistry, led us to pay particular attention to problems of blood collection. We tested several blood collecting tubes for contamination by these metals. Evacuated tubes must be avoided; polystyrene and polypropylene tubes are apparently the least polluting. However, strict rules cannot be made, and each biochemist should test the blood collecting devices he wants to use for trace elements analysis.

Aluminum↗
PubMed1982

Direct evidence that eseroline possesses morphine-like effects.

The opiate-like effects of eseroline, a physostigmine derivative, were studied in different tests. The antinociceptive effect of eseroline given s.c. and intracerebrally could be detected in the rat hot plate test and was reversed by naloxone. The apparent pA2 values of naloxone demonstrated with eseroline and morphine were found to be equal, suggesting an effect on similar receptors. Eseroline also had opiate agonist activity on the isolated longitudinal muscle strip of guinea pig ileum and isolated nictitating membrane of the cat: presynaptically, it inhibited the contractions evoked by stimulation and its effect was antagonized by naloxone. Eseroline reduced acetylcholine release from the myenteric plexus of the longitudinal muscle strip when the cholinesterases had been inhibited by physostigmine. In addition, it was also found that eseroline antagonized the inhibitory effect of normorphine in the longitudinal muscle strip and potentiated the effect of exogenous acetylcholine on smooth muscle, both effects being attributed to its anticholinesterase activity. The analgesic effect of eseroline was not related to its anticholinesterase activity.

Acetylcholine↗
PubMed1982

[Genetic activity of 1,2-dichloroethylene. A). In vitro studies].

1,2-dichloroethylene cis and trans were tested for their ability to induce point mutation, mitotic gene conversion and mitotic recombination in a diploid strain (D7) of the yeast Saccharomyces cerevisiae in a suspension test with and without a mammalian microsomal activation system. In this test 1,2-DCE cis and trans were toxic but not genetically active even with S9 activation.

Dichloroethylenes↗
PubMed1982

[Genetic activity of 1,2-dichloroethylene. B). In vivo studies: effect on microsomal enzymes].

Mutagenicity study "in vivo" (Intravenous host mediated assay) confirms suspension test results with cis- and trans -1,2-dichloroethylene: no genetic effects could be detected. Single and repeated doses of trans-1,2-DCE induced liver aminopyrine demethylase and cytochrome P-450 whereas the cis- isomer decreased them. Similar results were obtained after induction with phenobarbital + beta-Naphthoflavone.

Aminopyrine N-Demethylase↗
PubMed1982

Reversible inhibition of acetylcholinesterase by eseroline, an opioid agonist structurally related to physostigmine (eserine) and morphine.

The action of eseroline--(3aS,8aR)-1,2,3,3a,8,8a-hexahydro-1,3a,8-trimethylpyrrolo[2,3-b]indo l-5-ol--salicylate was tested on preparations of ChE from different sources and on the longitudinal muscle of guinea-pig ileum. While eseroline is eseroline is extremely weak-acting on horse serum BuChE (Ki = 208 +/- 42 microM), it is a rather strong competitive inhibitor of AChE's, its Ki being 0.15 +/- 0.08 microM, 0.22 +/- 0.10 microM and 0.61 +/- 0.12 microM in electric eel, human RBC and rat brain, respectively. Eseroline inhibitory action in AChE in independent of the duration of pre-incubation and appears fully developed in less than 15 sec. This action is also rapidly reversible; after pre-incubation followed by dilution, maximum enzymic activity is regained within 15 sec. The electrically-evoked contractions of the longitudinal strip were inhibited by concentrations of eseroline in the range 0.2-15 microM, while they were increased by concentrations over 20 microM. In the same preparation, without electrical stimulation, but in the presence of naloxone, eseroline induced contractions at concentrations higher than 5 microM. This effect was antagonized by atropine. The inhibitory activity of eseroline parallels, as regards selectivity, potency and kinetics, that of the phenolic anticurare agent edrophonium, while it differs markedly from that of physostigmine.

Animals↗
PubMed1982

Presence of functionally active beta-adrenoceptors in rat mast cells. Correlation between (--)[3H]-dihydroalprenolol binding and inhibition of histamine release.

The correlation between the binding of a beta-adrenoceptor antagonist, (--)[3H]-dihydroalprenolol (DHAP), and the adrenergic inhibition of histamine release by acetylcholine and by compound 48/80 was studied with isolated purified rat mast cells and in rat mast cell crude membrane fractions. Acetylcholine-evoked histamine release was inhibited by catecholamines, in the order isoprenaline greater than adrenaline greater than noradrenaline. Pretreatment of cells with (--)alprenolol antagonized the inhibitory effect of isoprenaline on acetylcholine-induced histamine release. 40/80-evoked histamine release was blocked by isoprenaline at significantly higher concentrations than those required to inhibit cholinergic histamine release. The inhibitory effect of isoprenaline was equally antagonized by preincubating mast cells with (--)alprenolol. Specific binding sites for DHAP have been demonstrated in rat mast cell membranes. The specific binding of DHAP was inhibited by adrenoceptor agonists and antagonists according to the stereospecificity of these compounds. A close correlation between the binding-inhibitory potency of various adrenergic compounds and the data obtained in the pharmacological experiments was found, thus indicating the presence of beta-adrenoceptors in rat mast cells.

Acetylcholine↗
PubMed1981

Eseroline: a new antinociceptive agent derived from physostigmine with opiate receptor agonist properties. Experimental in vivo and in vitro studies on cats and rodents.

We report that eseroline, until now thought devoid of any biological action, is a potent antinociceptive agent. Its antinociceptive action is stronger than that of morphine in all tests studied and, though shorter lasting than that of the latter, has a latency of only a few minutes by subcutaneous route. Eseroline, like morphine and enkephalins, inhibits the electrically evoked twitches of the mouse vas deferens and of the guinea-pig ileum. Eseroline, moreover, releases 5-hydroxytryptamine from cat brain cortex in way similar to that of morphine and physostigmine.

Analgesics↗
PubMed1981

Hypothermia induced in rabbits by intracerebroventricular taurine: specificity and relationships with central serotonin (5-HT) systems.

The intracerebroventricular (i.c.v.) injection of taurine produced a fall in core temperature, the extent of which was dependent on the thermal gradient between the body and the environment. Concurrently, a sudden rise in ear skin temperature, which was maximal in the cold and negligible at 30 degrees C, was observed. The fever induced by i.v. injection of Escherichia coli endotoxin was antagonized by taurine. High temperatures produced by i.c.v. injection of prostaglandin E1 were also suppressed by taurine. Intracerebroventricular injections of bicuculline and strychnine, but not those of picrotoxin or pentylentetrazol, were able to reduce hypothermia induced by taurine. Intracerebroventricular injection of the taurine reuptake inhibitor guanidinoethyl sulfonate, on the contrary, did enhance the hypothermic response to taurine. Injection (i.c.v.) of serotonin (5-HT) elicited a fall in core temperature which was not accompanied by a rise in ear skin temperature, but was antagonized by the concurrent injection of the 5-HT antagonist methysergide. Pretreating animals with p-chlorophenyl-alanine caused a significant fall of brain 5-HT contents and a reduction of the hypothermic response to taurine. The latter effect was also observed when the animals were i.c.v. pretreated either the methysergide or with the 5-HT reuptake blockers chlorimipramine and Lilly 110140. These findings give support to the hypothesis that taurine-induced hypothermia in rabbits mediated by some taurine sensitive cells and, at least in part, by serotonergic synaptic mechanisms.

Animals↗
PubMed1981

Uremic middle molecules: analytical study of middle molecular weight fractions subpeak b4-2.

Fractions containing substances weighing less than 1800 daltons have been obtained from hemofiltrate and peritoneal dialysis fluid. Oligosaccharides and glycopeptides were evidenced in these fractions by paper chromatography. This analytical procedure has been applied to a fraction containing peak b4-2 obtained by molecular exclusion chromatography on Sephadex G-15 followed by ion exchange chromatography on Sephadex A-25 (Cueille et al.). Preparative paper chromatography of this fraction evidenced 3 carbohydrate and 3 peptidic fractions. Study of the carbohydrate fraction (01, 03, 04) by gas-chromatography and mass spectrometry shows that they are composed of glucuronoconjugates whose aglycons have not been identified. Fraction 04 which contains subpeak b4-2 has been found to have an inhibitory effect on the action potentials of the sural nerve of the frog.

Chromatography, Gas↗