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Biomedical subjects

C Ortega

Publications and source records attributed to C Ortega.

At least 55 records · Page 3Linked to original sources
PubMed1990

Prevention of nausea and vomiting in cisplatin-treated patients by a selective 5-hydroxytryptamine (5-HT3) receptor antagonist, ICS 205-930.

The results of an open study designed to evaluate the prevention of cisplatin-induced emesis by the specific 5-HT3 receptor antagonist ICS 205-930 are reported. Fifty-four cancer patients, treated with diverse chemotherapy regimens, all including cisplatin (greater than = 50 mg/m2), received ICS 205-930 for a total of 165 courses. ICS 205-930 (10 mg) was given i.v. immediately before the cisplatin infusion and a second 10-mg dose was given immediately after. In 109 courses (66%) the patients did not have any vomiting episodes. Nausea was absent in 44.8% of courses. More than 3 vomiting episodes occurred only in 17 (10.4%) courses, and severe nausea only in 11 (6.6%). ICS 205-930 was extremely well tolerated. Mild headache occurred during 7 courses (4.2%) in 4 patients, hypotension during 5 courses (3%) in 3 patients and lipothymia in 2 courses (1.2%) in 2 patients. These results suggest that ICS 205-930 is an effective and well tolerated antiemetic drug in patients receiving cisplatin chemotherapy.

Adult↗
PubMed1989

Immunomodulation of HLA class I and II expression on a human tumor derived cell line by 5-azacytidine, bacterial lipopolysaccharide, gamma interferon and a phorbol ester.

The modulation of histocompatibility antigens (HLA) expression by four different agents (gamma-IFN, LPS, PMA and 5-azaC) was investigated on a human tumor derived cell line that did not constitutively express HLA class I and class II molecules on its surface. Demethylating drug 5-azaC induced HLA class I but not HLA class II antigen expression. Gamma interferon and LPS induced HLA-DR and HLA-DP, but not HLA-DQ class II nor HLA class I antigens, while phorbol ester was unable to induce either class I or II molecule expression of the HLA system. These results suggest that HLA class I expression is constitutively inhibited by methylation of its coding genes. Treatment with 5-azaC leads to the HLA class I molecule expression, while HLA class II genes, DR and DP, seem to be under a different inhibitory mechanism as it was induced by LPS and gamma-interferon but not by 5-azaC. HLA-DQ class II antigens were not detected in response to any of the immunomodulators used.

Antibodies, Monoclonal↗
PubMed1987

Allergic reactivity and socio-economic level in a tropical environment.

As some factors associated with the tropical environment can modify the expression of atopic disease, various indicators of allergic reactivity were compared between allergic and non-allergic subjects of different socio-economic level in Caracas, Venezuela (Lat. 10 degrees N). The socio-economic levels considered were high (HSEL), medium-high (MSEL) or low (LSEL). As generally found in temperature climates, in the HSEL the total serum IgE levels of allergic patients were significantly greater than those of non-allergic individuals (geometric means of 274 vs 126 IU/ml, respectively), as were also the specific serum IgE antibody levels (55.6 vs 23.8% positive, respectively, for house dust). These results correlated closely with the skin-test reactivity of these subjects (60.3 vs 17.5% positive for house dust). In this group, the degree of intestinal helminthic infection was low (5.6% positive for Ascaris). In contrast, for the MSEL where the degree of parasitic infection was higher (13.0%), the total serum IgE levels were elevated in both allergic and non-allergic subjects (602 vs 363 IU/ml). Similarly, positivity for specific IgE antibody was high, and comparable between allergics and non-allergics of this group (61.5 vs 54.2%), as was also the case for skin-test reactivity (71.9 vs 60.4%). In the LSEL, parasitic infection was prevalent (47.6%), and the total serum IgE levels were markedly elevated, with little difference occurring between allergic and non-allergic individuals (2269 vs 1981 IU/ml). The positivity for specific IgE antibody was high, and effectively independent of the allergic state (75.6 vs 53.7%), but in contrast the skin test reactivity was relatively low (22.0 vs 9.8%).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1984

Structural studies of the Escherichia coli O-antigen 6.

The structure of the Escherichia coli O-antigen 6 has been investigated using n.m.r. spectroscopy, methylation analysis, and various specific degradations. It is concluded that the O-antigen is composed of pentasaccharide repeating-units having the following structure. (Formula: see text)

Antigens, Bacterial↗
PubMed1978

Studies of antithyroid antibodies in Down's syndrome.

The presence of antithyroid antibodies (antithyroglobulin and antimicrosomal) in serum of patients with Down's syndrome and their respective mothers were studied based on data from the literature, showing a possible correlation between the presence of these antibodies in the serum of mothers and the birth of mongoloid children. Antithyroid antibodies were studied in 40 patients with Down's syndrome, with ages ranging from 5 months to 21 years old, 24 males and 16 females and in the respective mothers whose ages varied from 22 to 66 years. In none of the analyzed sera of the mongoloids as well of their mothers, the authors were able to detect the antithyroid antibodies studied.

Adolescent↗
PubMed1977

Studies on thyroid and hypophysary thyrotrophic hormone (TSH) in Down syndrome.

Serum TSH was studied in 22 patients with Down syndrome, from 4 to 15 years old. In 6 of these patients radioidine uptake by thyroid gland after 2 and 24 hours of administration and clearance rates before and after TSH stimulus (10 mul-IM) were measured. Results show that serum TSH was normal in 17 patients and above normal limits in 5 patients. Thyroid uptake after 2 hours as well clearance rates, both below normal, had a response to TSH stimulus with normal or below values. These data along with previous reports, suggest, that in children with Down syndrome, there is a thyroid dysfunction in which a slow response no TSH stimulus seems to be the basic defect.

Adolescent↗
PubMed1975

In vivo measurement of variations in the oxygen 18 content of water in rat brain.

A method of analysis for oxygen 18 is described, based on the anodic oxidation of specially prepared tantalum wires implanted through cannulas into the tissue of living animals. The thin anodic oxide layer formed on these wires is then analyzed by the 18O(p,alpha)15N reaction. The isotopic oxygen concentration of water in the brain obtained by this method compares very well with the values obtained by conventional analysis using mass spectrometry. This in vivo method of nuclear microanalysis has been used in both metabolic and equilibration experiments involving oxygen 18. The half-life for the turnover of 18O in body water was found to be about 3 days. A simple three-pool model is presented which can account for the experimental results obtained from the dilution by body water of interperitoneally injected water highly enriched in 18O.

Animals↗
PubMedDate not supplied

Verrucous hemangioma: report of two cases and review of the literature.

Verrucous hemangiomas are usually congenital lesions which typically present as warty, bluish, vascular papules, plaques, or nodules, mainly on the lower limbs of children. They show no tendency to spontaneous resolution, and tend to spread and recur after inadequate treatments. We report two instances of verrucous hemangioma, one in an adult and one in a child, discuss the clinical, histopathologic, and therapeutic aspects of this entity, and review the literature.

Aged↗
PubMedDate not supplied

[Adjuvant chemotherapy in gastric carcinoma].

The adjuvant chemotherapy (A.C.) is considered as a complementary treatment in patients who underwent radical surgery for gastric cancer, with complete removal of the tumor and absence of macroscopically detectable metastasis. This treatment is generally started within 4-6 weeks after the operation. The indication to A.C. is related practically only to the stage of the disease, due to the fact that no other prognostic factors of an increased risk of relapse have been detected. Two metanalysis have been recently published by Earle (1998) and Floriani (1998); both the two have recognized a possible effective role of the CA for Gastric Cancer. Naturally these "impressions" of efficacy documented by these two metanalysis should be confirmed through new trials with larger recruitment. In these new trials the new generation schedules (weekly PELF, ECF plus 5-FU), which showed an increased response for advanced disease, should be administered.

Chemotherapy, Adjuvant↗
PubMedDate not supplied

Cryopreservation of ovules and somatic embryos of citrus using the encapsulation-dehydration technique.

Cryopreservation of ovules and somatic embryos from several genotypes of citrus was achieved using the encapsulation-dehydration technique. Survival of cryopreserved ovules was occasional and erratic after different pregrowth conditions in liquid medium with 0.75M, 1M or up to 1.25M sucrose. An efficient cryopreservation protocol was established for somatic embryos derived from two embryogenic sources (ovules and cut thin layer explants from stigma, style and ovaries). High survival rates (75-100%) were consistently obtained after 1 day pregrowth in 0.75M sucrose, desiccation down to 20-25% moisture content in the beads and direct immersion in liquid nitrogen. The histological study showed that embryos subjected to the encapsulation-dehydration, accumulated high sucrose levels which appear to ensure the recovery of the whole embryo after cryopreservation.

Cell Survival↗