PubMed Health⌕ Search

Biomedical subjects

R Fuentes

Publications and source records attributed to R Fuentes.

At least 37 records · Page 2Linked to original sources
PubMed1995

Phase II trial of carboplatin in combination with etoposide in locally advanced large cell carcinoma and adenocarcinoma of the lung.

A total of 18 patients with locally advanced (Stage III) adenocarcinoma and large cell undifferentiated carcinoma of the lung, previously untreated, were enrolled in a Phase II trial. Treatment consisted of carboplatin 325 mg/m2, day 1 and etoposide 100 mg/m2 on days 2 and 3. All patients were evaluable for response. Of these, one patient had a partial response (5.5%; confidence interval 0-24%). Toxicity comprised mainly leukopenia and anaemia. Other toxicities were mild. This Phase II study evidenced a poor response rate for these regimes on adenocarcinoma and large cell undifferentiated carcinoma of the lung.

Adenocarcinoma↗
PubMed1995

Neurological assessment of high grade astrocytomas following high dose radiotherapy as sole treatment.

Between January 1985 and June 1991, 19 patients, in whom the site and extension of the tumour prevented surgical excision, were treated with high dose radiotherapy as sole treatment for high grade astrocytomas. Quality of life, according to functional capacity, was measured prospectively before treatment and 4 weeks later. High dose radiation improved the functional capacity in only four of the patients (21%). The mean duration of improvement was 12 weeks and median survival 22 weeks (range 4-80). We conclude that high dose radiotherapy is not very useful and is probably not justified in this group of patients.

Astrocytoma↗
PubMed1995

[Seroprevalence of Epstein Barr virus infection in a healthy population of Santiago de Chile].

To study the rate of infection by Epstein Barr virus (EBV) in Santiago, Chile, the prevalence of antibody to the viral capsid antigen (VCA-IgG) was determined in a group of 663 healthy individuals grouped by age and socioeconomic level (SEL). In addition, several risk factors for infection were studied. VCA-IgG was determined by ELISA. The total prevalence was 76.7%. When grouped by age and SEL, 50% of the children from low and medium SEL had been already infected by the age two, compared to 5.9% in the high SEL (p < 0.01). However, by age twenty, 90% of the total sample had already specific antibodies to EBV. Age and number of household members were positively associated with the infection. High socioeconomic level represented a delay factor in the acquisition of the virus, (p < 0.01). These results show that EBV infection is frequent in Santiago, occurring early in childhood among medium and low SEL. Hence, the classical infectious mononucleosis should be recognized more frequently among adolescents and young adults belonging to high SEL, while the clinical spectrum of associated manifestations different from the typical mononucleosis syndrome should be investigated among those exposed in early age.

Adolescent↗
PubMed1992

Measurement of spherical aberration of intraocular lenses with the Ronchi test.

During the last few years the design and production of intraocular lenses (IOL's) have grown in a spectacular way due to the development of ocular surgery. Most of the data on the optics of IOL's have been based on conventional geometric calculations. In this paper, we present our results on the measurement of spherical wave aberration of IOL's by means of the Ronchi test.

Humans↗
PubMed1989

Five-year results of combined chemotherapy and mediastinal radiation therapy in small cell lung cancer.

Eighty-five patients with small cell lung cancer (limited disease = LD in 39, extensive disease = ED in 46) received the combination of cyclophosphamide, methotrexate, vincristine and CCNU, and mediastinal radiotherapy given simultaneously after the third course of chemotherapy. The duration of treatment was approximately 12 months. A complete response was obtained in 41% of LD and in 15% of ED patients, and a partial response in 38 and 22%, respectively. Median survival was 55 weeks for LD and 37 weeks for ED patients. Two patients (5%) with LD have survived free of disease more than 3 years since their diagnosis.

Carcinoma, Small Cell↗
PubMed1977

Carbon-13 as a tool for the study of carbohydrate structures, conformations and interactions.

The application of 13C-NMR spectroscopy to problems involving the structures and interactions of carbohydrates is described. Both 13C-enriched and natural abundance compounds were used and some advantages of the use of the stable isotope are described. Carbon-carbon and carbon-proton coupling constants obtained from 1-13C enriched carbohydrates were employed in the assignment of their chemical shifts and to establish solution conformation. In all cases studied thus far, C-3 couples to C-1 only in the beta-anomers while C-5 couples to C-1 only in the alpha-anomers. C-6 and C-2 always couple to C-1 in both anomeric species. The alkaline degradation of glucose [1-13C] to saccharinic acids was followed by 13C-NMR. The conversion of glucose [1-13C] to fructose-1, 6-bisphosphate [1, 6-13C] by enzymes of the glycolytic pathway was shown as an example of the use of 13C-enriched carbohydrates to elucidate biochemical pathways. In a large number of glycosyl phosphates the 31P to H-1 and 31P to C-2 coupling constants demonstrate that in the preferred conformation and phosphate group lies between the O-5 and the H-1 of the pyranose ring. The influence of paramagnetic Mn2 + ions on the proton decoupled 13C-NMR spectra of uridine diphosphate N-acetylglucosamine indicates that the Mn2 + interacts strongly with the pyrophosphate moiety and with the carbonyl groups of the uracil and N-acetyl groups.

Carbohydrates↗
PubMed1975

Carbon-13 nuclear magnetic resonance studies of adenosylcobalamin and alkylcorrinoids, selectively enriched with carbon-13.

The carbon-13 nuclear magnetic resonance spectra of a series of alkylcorrinoids, selectively enriched with 13C in the alkyl ligand, were recorded at 25.2 MHz and 25 degrees. The nature of the axial ligands markedly affects the chemical shift of the labeled alkyl moiety (trans effect) as well as the 13C resonances of selected carbon atoms of the corrin ring (cis effect). Although a number of factors appear to influence the trans effect on the chemical shift of the alkyl ligand (important among them being electric field effects), the cis effect appears to be dominated by changes in charge density (at the methine bridge carbon atoms, C-5, C-10, C-15) and by steric effects (at the methyl groups at C-1, C-5, and C-15) accompanying axial ligation. Spin-latice relaxation times of several organocorrinoids, selectively labeled with 13C in the ligands attached to cobalt, were also measured. The T1 values of the methylene carbons of [5'-13C]adenosylcobalamin and [2-13C]carboxymethylcobalamin are very similar to that of the methine bridge carbon atom C-10 of the corrin ring, indicating that rotation about the carbon-cobalt bond of these two corrinoids is severely restricted. On the other hand, internal rotation about the carbon-cobalt bond of methylcobalamin is rapid.

Adenosine↗
PubMedDate not supplied

Relationships among personnel tests, age, and job performance.

Relationships among an information-processing based test battery, job performance, and age were examined using a sample of petroleum transport drivers. The results suggest that when age differences in job performance occur, they can be better explained by performance on valid predictors rather than age per se. The findings are discussed in the context of moderated models of job experience, the Age Discrimination in Employment Act (ADEA), and the erroneous use of age as a surrogate measure in personnel decision making.

Accidents, Traffic↗
PubMedDate not supplied

Tumor markers (CEA, CA 125, CYFRA 21-1, SCC and NSE) in patients with non-small cell lung cancer as an aid in histological diagnosis and prognosis. Comparison with the main clinical and pathological prognostic factors.

CEA, CA 125, SCC, CYFRA 21-1 and NSE were prospectively studied in 211 patients with non-small cell lung cancer and compared with clinical parameters (age, sex, Karnofsky Index, symptoms and smoking status), histopathological parameters (stage, histology, tumor size and nodal involvement), biological parameters (LDH and albumin) and the therapy used (surgery, chemotherapy or radiotherapy). Tumor marker sensitivity was CYFRA 21-1: 76%, CA 125: 55%, CEA: 52%, SCC: 33% and NSE: 22%. One of the tumor markers was abnormally high in 87% of the patients with locoregional disease and in 100% of the patients with metastases. Except for NSE, all tumor markers showed a clear relationship with tumor stage and histology and therefore enabled a better histological diagnosis. Abnormal CEA serum levels were mainly found in adenocarcinomas, CA 125 in large-cell lung cancers (LCLC) and adenocarcinomas and SCC in squamous tumors. Eighty-five percent of the patients with SCC levels >2 ng/ml had squamous tumors. Likewise, CA 125 levels <60 U/ml or CEA <10 ng/ml excluded adenocarcinoma or LCLC with a probability of 82 and 91%, respectively.

Antigens, Neoplasm↗