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Biomedical subjects

R Rodriguez

Publications and source records attributed to R Rodriguez.

At least 307 records · Page 17Linked to original sources
PubMedDate not supplied

A death from fentanyl overdose.

A case of death from self-injection of fentanyl and a method for its detection in autopsy specimens are reported. Fentanyl was measured by extraction of biological samples with ethyl acetate, partitioning into 0.1N HCl, then reextracting into ethyl acetate after alkalinization of the acid phase. After reducing to a residue, the fentanyl was measured by selective ion monitoring gas chromatography/mass spectrometry. Concentrations of 4.8, 6.3, and 4.7 micrograms/L were found in blood, urine, and bile, respectively.

Adult↗
PubMedDate not supplied

Dose levels due to neutrons in the vicinity of high-energy medical accelerators.

High-energy photons are generated for use in radiation therapy by the deceleration of electrons in metal targets. Fast neutrons are also generated as a result of (gamma, n) and (e, e'n) interactions in the target, beam compensator filter, and collimator material. In this work the absorbed dose due to neutrons was measured at the center of a 10 X 10-cm photon beam and 5 cm outside of the beam edge for a number of treatment units (Varian Clinac-18, Allis-Chalmers 25-MeV betatron, and Brown Boveri 45-MeV betatron). Dose levels due to slow and fast neutrons were also established outside of the treatment rooms and a Bonner sphere neutron spectrometer system was employed to determine the neutron energy spectrum due to stray neutron radiation at each accelerator. For the linac it was found that the neutron dose at the beam center was 0.0039% of the photon dose and values of 0.04% and 0.053% were observed for the Allis-Chalmers betatron and the Brown Boveri betatron. Dose-equivalent rates in the range 0.3-22.5 mrem were measured for points outside the treatment rooms when the accelerators were operated at a photon dose rate of 100 rad/min at the treatment position.

Environmental Exposure↗
PubMedDate not supplied

Nuclear grade and DNA ploidy in stage IV breast cancer with only visceral metastases at initial diagnosis.

AIMS AND BACKGROUND: The presence of early metastases to distant sites in breast cancer patients is an infrequent event whose mechanisms are still not clear. The aim of this study was to evaluate the biologic and clinical role of DNA ploidy and cell nuclear grade of primary tumors in the metastatic process of a series of stage IV previously untreated breast cancer patients with only visceral metastases. METHODS: DNA flow cytometry analysis on paraffin-embedded material and cell nuclear grading of primary tumors was performed on a series of 50 breast cancer patients with only visceral metastases at the time of initial diagnosis. RESULTS: Aneuploidy was found in 28/46 (61%) of evaluable cases and was independent of site of involvement, clinical response, time of progression and overall survival of patients. Of the 46 cases evaluable for nuclear grade, 5 (11%), 16 (35%) and 25 (54%) were classified as G1 (well-differentiated) G2 and G3, respectively. Nuclear grade also was unrelated to response to therapy and overall survival, whereas time to progression was significantly longer in G1-2 than G3 tumors with the logrank test (P < 0.03) and multivariate analysis. CONCLUSIONS: Our results seem to stress the difficulty to individualize different prognostic subsets from a series of breast cancer patients with only visceral metastases at initial diagnosis according to DNA flow cytometry and nuclear grade.

Adult↗
PubMedDate not supplied

Hemodynamic effects of morphine during and early after cardiac operations.

Hemodynamics and blood gases were measured before and 15 minutes after small (10 mg/70 kg) doses of intravenously administered morphine in two groups of patients having open heart surgery. In one group, the study was undertaken after median sternotomy but before perfusion. The other group had been in the intensive care unit for approximately 1 hour. No changes were found in either group in cardiac index, atrial pressures, arterial pressure, or blood gas variables. However, mean systemic vascular resistance decreased from 41.5 to 35.4 after morphine was given postoperatively. Hence, hemodynamically, morphine is a safe drug if given in small doses for pain relief and sedation early after open heart surgery.

Adult↗
PubMedDate not supplied

Enflurane as a primary anesthetic agent for patients with chronic obstructive pulmonary disease.

For years, halothane has been the anesthetic agent of choice for patients with chronic obstructive pulmonary disease (COPD) and reversible airway disease (asthma). Enflurane was compared with halothane in 100 patients with COPD substantiated by spirometry and history. Intraoperative and postoperative complications in each relatively homogenous 50-patient group were assessed. Spirometry, blood gases, chest x-rays, incidence of complications involving secretions, coughing, wheezing, and cardiovascular problems were similar in both groups. Enflurane appears to be equivalent to halothane as an anesthetic in such patients.

Anesthesia, Inhalation↗
PubMedDate not supplied

DNA content by flow cytometry in gastric carcinoma: pathology, ploidy and prognosis.

BACKGROUND/AIMS: The prognostic relevance of histopathologic findings in gastric carcinoma is well established. Studies on DNA-ploidy are still scanty and contradictory. METHODOLOGY: Histopathologic parameters, DNA ploidy and S-phase were evaluated in 78 cancer patients curatively resected, using formalin-fixed paraffin-embedded tissue. RESULTS: Thirty-nine tumors (50%) were aneuploid. No significant correlation was found between histologic data and ploidy, but tumors with nodal involvement were more frequently aneuploid. In univariate analysis, tumor location (p=0.05), tumor size (p=0.01), differentiation grade (p=0.02), Lauren classification (p=0.01), deeper infiltration of gastric wall (p=0.001), nodal affectation (p=0.0000) and number of lymph nodes (p=0.01), TNM stage (p=0.0000), type of gastrectomy performed (p=0.04), and DNA ploidy (p=0.04) significantly influenced survival. S-phase values had no effect on prognosis. In the multiple regression model, factors independently associated with survival were TNM stage (p=0.0009), nodal affectation (p=0.01) and, marginally, ploidy (p=0.08). CONCLUSIONS: In gastric carcinoma curatively resected, the more relevant prognostic factors were stage and nodal involvement. Fifty percent of the tumors were aneuploid. Aneuploidy was significantly associated with poorer prognosis.

Adult↗
PubMedDate not supplied

[Potassium canreonate in neurosurgical brain edema].

The effect on the hydroelectrolytic metabolism and on the evolution of cerebral oedema of a new injectable aldosterone-antagonist, canreonate-potassium (Soldactone) was studied in two groups of subjects. The first group consisted of 14 patients who had undergone neurosurgical operations for expansive endocranial processes. The second group consisted of 18 non-operated cases of post-traumatic coma. The water-salt balance and the neurologic picture were carefully controlled during anf after 6-8 days of treatment with 600 mg/day of canrenoate-potassium by intravenous route. Comparison was also made between the conventional treatment with hyperventilation and that combined with canrenoate-K. The results obtained demonstrate that the aldosterone-antagonist induces a clinically significant retention of sodium. This is accompanied by a more favourable evolution of the cerebral oedema. Canrenoate-potassium was very well tolerated both locally and generally.

Adult↗
PubMedDate not supplied

Digestive cancer in relation to diet in Spain.

Dietary factors are widely considered to be largely responsible for the different cancer incidences observed in different populations. In the present study we investigated the possible influence of dietary habits on the incidence of digestive cancer in the provinces of Spain. Data on specific mortality due to digestive cancer corresponding to the period 1975 to 1985 were obtained from the Instituto Nacional de Estadística. Nutritional data on the different provinces were in turn gathered from the Instituto de Nutrición del Consejo Superior de Investigaciones Científicas. The information was processed by the SPSS statistical software package. Lifestyle and socio-cultural factors are found to influence dietary risk factors in digestive cancer, particularly among women. The most significant correlations with the different cancers studied corresponded to total energy intake (responsible for 27.4% of variance), animal fats, and smoked fish and coffee. The latter is related to oral and esophageal cancer in particular (responsible for 15.4% of variance). Consumption of carrots and frozen vegetables is responsible for 6.5% of variance, vs. 4.4% of variance for alcoholic beverages, sugar, and Vitamin D. Differences are noted between both the sexes and their relationship to the different cancers studied.

Adult↗
PubMedDate not supplied

Pathogenicity of two strains of Mycoplasma gallisepticum in broilers.

Strains F and R of Mycoplasma gallisepticum (MG) were compared in two laboratory trials for their relative pathogenicity in terms of inducing airsacculitis and antibody production to MG. Chickens exposed to the R strain had significantly higher incidence of air-sac lesions (P less than 0.05) and greater severity of airsacculitis than did chicks exposed to the F strain. In both trials, chickens vaccinated simultaneously with Newcastle disease-infectious bronchitis vaccine and exposed to MG had more severe lesions than did chickens exposed to mycoplasma alone. chickens exposed to the F strain had significantly lower geometric mean hemagglutination-inhibition antibody titers to MG than did chicks exposed to the R strain. Chickens vaccinated simultaneously with Newcastle disease-infectious bronchitis vaccine and exposed to R strain had significantly lower body weights than did chickens in the other group.

Air Sacs↗
PubMedDate not supplied

Evaluation of a vaccine against Mycoplasma gallisepticum in commercial broilers.

The efficacy of live Mycoplasma gallisepticum (MG) vaccine against respiratory mycoplasmosis was studied in three laboratory trials with commercial broilers. Broiler chickens were infected with the F or R strain of MG by eyedrop at 1 day of age, and challenged by aerosol exposure to the R strain of MG along with eyedrop vaccination against Newcastle disease and infectious bronchitis at 30 or 34 days of age. Observations were made of macroscopic lesions, severity of airsacculitis, isolations of MG, serologic test results, clinical signs, and mortality. In all the vaccinated groups, the air-sac-lesion score was lower after challenge than in unvaccinated control chickens. After challenge the control group also had a higher number of MG isolations from the air sac than did the vaccinated chickens. There were no air-sac lesions observed in broilers before challenge in 2 of 3 trials.

Air Sacs↗
PubMedDate not supplied

Development of human leukemia U-937 cell sublines resistant to doxorubicin: induction of differentiation and altered sensitivities to topoisomerase-directed drugs.

Cell sublines resistant to doxorubicin (DOX) were developed from the human leukemia cell line, U-937/WT, exposed to stepwise DOX increases. In contrast to U-937/WT cells, the DOX-resistant U-937/RD cells have longer doubling time; are more differentiated along the monocytic lineage as determined by the presence of morphological features and mRNA coding for the monocyte colony-stimulating factor-1 receptor; synthesize the apoptosis-associated Bax protein; are less sensitive to apoptosis-inducing topoisomerase II-directed drugs, apparently because of increased synthesis of P-glycoprotein; and are practically non-tumorigenic when xenografted in nude mice. However, U-937/WT and U-937/RD cells exhibit similar sensitivity to the apoptosis-inducing drug 9-nitrocamptothecin. These findings suggest that several mechanisms are involved in the development of DOX-resistance in U-937 cells, and further, 9-nitrocamptothecin can overcome resistance to DOX. These findings may have clinical implications.

ATP Binding Cassette Transporter, Subfamily B, Mem↗