Biomedical subjects

A L Martínez

Publications and source records attributed to A L Martínez.

7 recordsLinked to original sources

PubMed2006

Evaluation of the antinociceptive effect of Rosmarinus officinalis L. using three different experimental models in rodents.

The rationale of this investigation was to examine the antinociceptive effect of an ethanol extract of Rosmarinus officinalis (RO) aerial parts, using three different experimental models: acetic acid-induced writhing test and formalin test in mice; and a model of arthritic pain: "pain-induced functional impairment model in the rat (PIFIR model)". The antinociceptive efficacies were evaluated using several dose-response curves and time courses. The antinociceptive effects from RO extract were compared with the antinociceptive effect of either tramadol (TR: 3.16-50 mg/kg, i.p. in mice, and 1.0-31.62 mg/kg, i.p. in rats) or acetylsalicylic acid (AA: 31.62-562.32 mg/kg, p.o.). RO extract (10-300 mg/kg, p.o.) significantly (P < 0.001) reduced the number of writhing movement induced by the i.p. administration of acetic acid solution in a dose-dependent way (ED50 = 108.84 mg/kg, whereas, TR showed an ED50 = 12.38 mg/kg). In addition, RO extract (30-300 mg/kg) significantly (P < 0.001) inhibited licking and shaking behaviours in both early (neurogenic pain) and in the late (inflammatory pain) phases of the formalin test. These effects were like those produced by TR. Concerning the results using the PIFIR model, RO extract (30-3000 mg/kg, p.o.) like either TR or AA, produced a significant (P < 0.001) and dose-dependent antinociceptive response in rats (RO: ED50 = 222.78 mg/kg versus TR: ED50 = 11.06 mg/kg and AA: ED50 = 206.13 mg/kg). These results strongly suggest that aerial parts of RO possess antinociceptive and anti-inflammatory activity, and reinforce the use of this plant in folk medicine.

Analgesics↗

PubMed2006

Pharmacological evaluation of the anxiolytic and sedative effects of Tilia americana L. var. mexicana in mice.

The anxiolytic and sedative effects of Tilia americana L. var. mexicana (Schltdl.) Hardin inflorescence extracts and its acute toxicity were tested. Sodium pentobarbital (SP)-induced hypnosis potentiation (SPP), as well as ambulatory activity and anti-anxiety response in three different experimental models were evaluated with hexane and methanol extracts in mice. In order to determine the proper timing of assessments and to identify the most active extract, a 100mg/kg dosage of hexane, ethyl acetate and methanol crude extracts were tested on SPP after 15, 30 and 60min of the administration. Then a dose-response curve was made for the hexane (10-1000mg/kg) and methanol (10-300mg/kg) extracts in all experimental models. Both extracts produced a significant and dose-dependent lengthening in the time of SP, with the methanol extract being more potent than the hexane extract at 60min after administration. Moreover, a significant and dose-dependent attenuation in the anxiety-response in the plus-maze test and exploratory cylinder activity, but also a diminution in the ambulatory activity and in the head dipping response were observed resembling the response to diazepam. Acute toxicity was observed with less dose of methanol extract (LD(50)=375mg/kg) in comparison to the hexane extract (LD(50)>2900mg/kg). Results of the present study shows that Tilia americana var. mexicana possesses depressant activity on the CNS similar to the better-studied species of European Tilia and reinforces its use as anxiolytic and sedative in traditional medicine.

Animals↗

PubMed2006

Neuropharmacological effects of an ethanol extract of the Magnolia dealbata Zucc. leaves in mice.

Magnolia dealbata Zucc. is considered to have tranquilizer and anticonvulsant properties in Mexican traditional medicine. In the present study we report the effects of a crude extract of Magnolia dealbata (30, 100 and 300 mg/kg) on mouse central nervous system (CNS). Pharmacological effects were tested on ambulatory activity, anti-anxiety response, sodium pentobarbital-induced hypnosis and pentylenetetrazole (PTZ)-induced seizures in comparison to honokiol, buspirone, ethosuximide and diazepam as corresponding reference drugs. No changes in spontaneous locomotor activity were produced posterior to Magnolia dealbata administration; however, a significant and dose-dependent diminution in the anxiety response was observed in experimental models such as plus-maze, head-dipping and exploratory rearing tests. Magnolia dealbata not only prolonged the time of sodium pentobarbital-induced hypnosis and delayed the onset of PTZ-induced mioclonus and clonus, but also hindered the presence of tonic seizures and avoided mortality. The hypnotic, anxiolytic and anticonvulsant effects obtained in these experiments support the hypothesis that Magnolia dealbata possesses CNS activity and reinforces the popular use in Mexican traditional medicine.

Animals↗

PubMed1999

Sister-chromatid exchanges induced by disulfiram in bone marrow and spermatogonial cells of mice treated in vivo.

Disulfiram is a widely used drug to treat alcoholism due to its capacity to inhibit the metabolism of acetaldehyde; however, its genotoxic potential is not well known. Thus, the aim of this investigation was to determine whether the chemical may induce sister-chromatid exchanges (SCEs) in an in vivo study using mouse bone marrow and spermatogonial cells. We used doses of 200, 400 and 800 mg/kg body weight and compared the obtained data with the values determined in a negative control group as well as with a positive control group (cyclophosphamide, 50 mg/kg). The results in both systems indicated a weak genotoxic response by the chemical. In the case of bone marrow, a significant SCE level was achieved only with the high tested dose, but in spermatogonial cells the three doses tested showed a significant difference with respect to the negative control. No significant alterations in the mitotic index or in the cell proliferation kinetics were observed in somatic cells. Concerning the effect of cyclophosphamide, an increase in the level of SCEs was observed in both types of cells, reaching more than three times the values obtained in their respective control groups.

Alcohol Deterrents↗

PubMed1999

[Thyroglossal duct cysts].

INTRODUCTION: A thyroglossal cyst (TGC) is an unusual neck lesion that is occassionally diagnosed in a general hospital that mostly attend adult patients. The aim of the current study was to analyze our experience in the management of these lesions. MATERIAL AND METHODS: The records of 43 patients operated on at the Social Security Hospital in Quito (Ecuador) from 1980 to 1998 for a thyroglossal duct cyst or fistula, were reviewed. RESULTS: Distribution was similar in both sexes. Mean age was 23. Thirty-five patients presented with a cystic lesion located in the midline or slightly laterally in the neck, closely related to the hyoid bone; the other 8 patients had a cutaneous fistula at the same place. All of the patients but one, underwent a radical Sistrunk procedure; complications were minor. In 5 patients (12%), a papillary thyroid carcinoma within the TGC was reported at the histologic study. No recurrence developed after a mean 23-month follow-up. CONCLUSIONS: A cyst or a fistula located at the level of the hyoid bone suggest a thyroglossal duct lesion. A papillary carcinoma can rarely occur within the TGC. A Sistrunk procedure is usually curative.

Adolescent↗

PubMedDate not supplied

Evaluation of the enhanced oral effect of omapatrilat-monolein nanoparticles prepared by the emulsification-diffusion method.

In the present study, the emulsification-diffusion method was optimized in order to obtain omapatrilat/monolein-nanoparticles (omapatrilat/MO-nanoparticles). The antihypertensive effect of omapatrilat/MO-nanoparticles in spontaneously hypertensive rats (SHR) after oral administration was evaluated. The results indicated that the variables involved in the process did not have an influence on particle size, and that the former is directly determined by the amphiphilic properties of MO. When SHR were orally treated with omapatrilat/MO-nanoparticles, blood pressure was significantly reduced and completely normalized after three days. This effect was markedly higher than that observed with omapatrilat suspensions. The effect of omapatrilat/MO-nanoparticles can be attributed to: (i) The molecular dispersion of the drug into the lipophilic domain of monolein's bicontinuous phase; (ii) the adhesive properties of the nanodispersion on the gastrointestinal mucosa; (iii) the high surface area of the dispersion; (iv) the intraluminal interaction between MO, the mixed micelles arising from the digestive process, and omapatrilat; and (v) the well-known absorption-promoting properties of lipids, and in particular, of MO. MO-nanoparticles can be an interesting system to increase the oral bioavailability of drugs.

Administration, Oral↗

PubMedDate not supplied

Anaplastic thyroid carcinoma in ecuador: analysis of prognostic factors.

The highest incidence of anaplastic thyroid carcinoma (ATC) has been reported in countries with endemic goiter, such as in Ecuador. In this country, ATC is the third most common histologic type of thyroid cancer, following papillary and follicular carcinoma. The aim of this study was to review the clinical presentation and the results of treatment of a large consecutive series of ATC patients treated at the oncological department of a general hospital in Quito, Ecuador. This is a retrospective study of 30 patients diagnosed with ATC at the Social Security Hospital, from 1982 to 1998. Symptomatic rapidly growing neck masses were generally present. All the patients had histological diagnosis of ATC. Two patients with pulmonary metastases and pleural effusion died before treatment could be instituted. Twenty-eight patients received at least one type of treatment: surgery, radiation therapy (RT), or chemotherapy (CT). The two most frequently employed therapeutic modalities were surgery followed by RT and/or CT in 14 patients and surgery alone in 9 patients. Surgery was performed in 23 patients but a complete resection was possible in only 14 patients. RT, postoperatively or alone, was given to 17 patients. Only 5 patients received doses ranging from 4,000 to 5,000 cGy and 4 patients more than 5,000 cGy. CT was administered to 17 patients. Doxorubicin alone was given to 10 patients and different combinations to the remaining patients. Local control was obtained in 8 of 14 complete resections. The prognostic value of the following parameters was studied by univariate analysis: duration of symptoms, size of the tumor, extent of glandular involvement, type of treatment, and surgical margins. A statistically longer survival was found in cases of differentiated carcinoma with areas of ATC or tumor limited to one lobe, those patients who received a complete treatment of chemotherapy, and those patients with tumors smaller than 10 cm and with duration of symptoms longer than 4 months. Longer mean survivals were seen in patients with longer duration of symptoms and smaller lesions. Five patients with focal anaplastic lesions within a differentiated thyroid carcinoma or a lesion limited to one lobe had a significant better survival (a mean of 20 months).

Adult↗