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Biomedical subjects

L Gil

Publications and source records attributed to L Gil.

At least 55 records · Page 3Linked to original sources
PubMed1993

Mutagenicity of organic extracts from Santiago (Chile) airborne particulate matter.

The Ames test has been used to detect the mutagenic activity of organic extracts from Santiago (Chile) airborne particles collected in 1990 and 1991 in one of the monitoring net system stations (MACAM). The samples were assayed with the strains TA98, TA98-NR, and TA98/1,8-DNP6 of Salmonella typhimurium, in the presence and in the absence of liver S9 fraction obtained from rats treated with Aroclor 1254. With the strain TA98 all the samples showed a very high mutagenic response either in the presence or in the absence of S9 fraction, suggesting that Santiago airborne particles contain both indirect-acting (polycyclic aromatic hydrocarbons) and direct-acting mutagenic agents. The mutagenicity of Santiago airborne particles was much higher than that reported in studies performed in other countries. Results obtained with the strains TA98-NR and TA98/1,8-DNP6 suggest that the extracts also contain mononitro and dinitroarenes. These nitroarenes have been described as very potent mutagenic agents, that can be generated by photochemical reactions under certain atmospheric conditions, or in the combustion of fuel, especially of diesel motors. The presence of polycyclic aromatic hydrocarbons and nitroarenes in Santiago airborne particles, as well as the high levels of mutagenicity detected, suggest that the inhabitants permanent exposure to these kinds of compounds represents a high risk for human health.

Air Pollutants↗
PubMed1990

Influence of capsaicin-sensitive afferent neurones on the acid secretory responses of the rat stomach in vivo.

1. The influence of capsaicin-sensitive afferent neurones in modulating acid-secretory responses has been investigated in the continuously perfused stomach of the anaesthetized rat. 2. Ablation of primary afferent neurones, after systemic neonatal pretreatment with high doses of capsaicin, did not modify acid responses to direct stimuli of the oxyntic cell with histamine (5 mg kg-1), pentagastrin (20 micrograms kg-1) or carbachol (4 micrograms kg-1). 3. Acid responses to hypoglycaemia induced by insulin (0.3 iu kg-1) were not influenced by systemic capsaicin pretreatment or by acute coeliac ganglionectomy. Vagotomy abolished this secretory response. 4. The increase in acid output induced by gastric distension (20 cmH2O) was abolished by systemic neonatal capsaicin pretreatment. Likewise, vagotomy and acute coeliac ganglionectomy eliminated this secretory response. 5. Acute intragastric infusion with high doses of capsaicin inhibited the acid responses to distension but failed to modify the increase in acid output induced by insulin. 6. Local application (7-14 days before) of capsaicin to the coeliac ganglion abolished the acid response to gastric distension. This lack of secretory response was not the result of a nonspecific destruction of the ganglion, since changes in intragastric pressure after electrical stimulation of the coeliac ganglion were unaffected by such treatment. 7. These observations indicate that peripheral capsaicin-sensitive sensory neurones, located both in the gastric mucosa and in the coeliac ganglion, play a physiological role in the acid secretory responses to gastric distension.

Anesthesia↗
PubMed1990

Zinc acexamate inhibits gastric acid and pepsinogen secretion in the rat.

Pretreatment with zinc acexamate (25-100 mg kg-1 i.p.) inhibited acid and pepsinogen secretion in the pylorus-ligated rat. Zinc acexamate (5-50 mg kg-1 p.o.) also inhibited the increases in acid secretion induced by carbachol (10 micrograms kg-1) and 2-deoxy-D-glucose (200 mg kg-1) in the perfused stomach of the anaesthetized rat. A delayed antisecretory effect was observed with this drug on histamine induced responses. High concentrations of zinc acexamate (10(-5) - 10(-2) M) did not modify the in-vitro activity of pepsin. Administration of zinc acexamate resulted in an increase in the presence of pepsinogen at the mucosal level. A morphological examination of the gastric mucosa confirmed an accumulation of zymogen-containing granules in the gastric chief cells of zinc acexamate-treated rats (50 mg kg-1 p.o.). These results indicate that zinc acexamate decreases acid and pepsinogen secretion in-vivo, and this may explain its antiulcer activity.

Aminocaproates↗
PubMed1990

Flumecinol, a novel inducer of testosterone 16 alpha-hydroxylation in male rats.

1. Flumecinol, a new inducer of the cytochrome P-450 monooxygenases, was studied in rats as a possible effector of liver microsomal testosterone oxidases. The drug enhanced the total content of liver cytochrome P-450 in immature and adult rats. 2. When total testosterone oxidation activity was compared in liver microsomes of treated and untreated rats, no differences in activities were observed in 60-day-old-rats, but a slight decrease was found in 35-day-old treated rats. 3. Several regio- and stereo-specific hydroxylases were modified by flumecinol administration; in 35-day-old rats only 16 alpha-hydroxylation was induced, whereas in 60-day-old rats a slight increase in 2 alpha-hydroxylation was also observed.

Aging↗
PubMed1990

[Specific character of movement disorders in children studying string instruments].

Orthopaedic examinations were carried out in 242 children studying string instruments. Various indispositions and deformations of the motor organs were found in 31 children. It has been demonstrated that they were mainly the result of technical errors in holding of the instrument, which caused overloading of the upper extremities and the spine.

Arm↗
PubMed1990

[The protease-antiprotease system in pathogenesis of transient arthritis of a single joint in children].

In 35 patients with transient arthritis of a single joint, levels of alpha-1-antitrypsin were determined in the serum in the acute stage of the disease, the recovery period, and the control group. The results were compared. Determination was that the results of examination have indicated a markedly increased level of carried out by the use of M-Partigen, immunodiffusive plates by the Mancini me-alpha-1-antitrypsin in the serum in children in the acute period of this disease and a significant decrease of its level in the period of subsidence of the clinical symptoms in comparison with the control group. The changes in the level of this enzyme indicate disturbance of protease-antiprotease balance in pathogenesis of this disease.

Arthritis↗
PubMed1990

[Ultrasonography in transient hip synovitis in children].

Ultrasonography was performed in 10 children with the symptoms of transient hip synovitis. In all the patients inflation of the capsule was found. At the following examinations subsidence of intraarticular exudate was observed.

Child↗