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Biomedical subjects

E Quintana

Publications and source records attributed to E Quintana.

At least 73 records · Page 4Linked to original sources
PubMed1990

Observations on the contrasting reaction of some electron dense stains applied on epoxy-embedded tissue sections.

Epon sections from glutaraldehyde-fixed rat bone marrow were treated with aqueous solutions of the following electron contrasting agents: uranyl acetate, ruthenium red, potassium permanganate, potassium dichromate, stannous chloride, palladium (II) chloride, sodium molybdate, phosphomolybdic acid, molybdenum heteropolyblue, phosphotungstic acid, iron(II)-phenanthroline, aluminium-hematoxylin, mercurochrome, cuprolinic blue, and sirius light turquoise blue. At the ultrastructural level, a high degree of electron opacity was always observed in mast cell granules and the crystalline inclusion (internum) of eosinophil granules. The chromatin revealed a somewhat lower and variable contrasting reaction, while the matrix (externum) of eosinophil granules appeared with scarce or no contrast. This pattern of electron opacity showed no correlation with the type of agent used; therefore, it can be assumed that binding processes based on the own chemical reactivity of the compounds are rather of secondary importance. The differential epoxy resin embedding of cell structures and the variable access of aqueous reagents through the non-polar plastic could be the predominant factors which account for these contrasting reactions.

Animals↗
PubMed1989

[Nephrotic syndrome and B leukemia].

A boy, aged 14 1/2 years, presented with Burkitt leukemia. His renal status was normal before treatment. Chemotherapy (SFOP LMB 86 protocol) was begun Oct. 9, 1986. After the first 2 courses of chemotherapy, the patient had Gram negative sepsis treated with cefotaxime, netilmycine, Vancomycin and ornidazole. During sepsis, nephrotic syndrome developed (albumin 25 g/l, non selective proteinuria 15 g/24 h), with moderately high blood pressure, functional renal failure (creatinine 141 mumols/l, U/P urea = 20), polyuria and tubular damage. Kidney ultrasonography was normal. Needle biopsy showed minimal glomerular lesions, acute tubular lesions, and no deposits in immunofluorescence. The nephrotic syndrome disappeared within 3 weeks, with treatment of leukemia. He is at present in complete remission with a follow-up of 25 months.

Adolescent↗
PubMed1988

Prognostic factors in 281 children with nonmetastatic rhabdomyosarcoma (RMS) at diagnosis.

Pretreatment characteristics of 281 children with nonmetastatic rhabdomyosarcoma, included in the registry of the International Society of Pediatric Oncology (SIOP) between January 1975 and December 1983, were examined to study the children's prognosis. The multivariate statistical method (Cox regression model) was used for each of two endpoints: survival time and disease-free time. The three most important predictors for survival time were primary site (p less than .001), clinical stage (p = .009), and sex (p = .020). The best results involved paratesticular and orbital primary sites, regardless of the clinical stage; males fared slightly better than females. These same three factors were also significant predictors for disease-free time.

Adolescent↗
PubMed1988

Detection of benzo[a]pyrene diol epoxide-DNA adducts in human placenta.

Human placenta is a readily available organ that responds to maternal environmental insult and has been previously used to investigate metabolism and bioactivation of procarcinogens, for example, benzo[a]pyrene. HPLC in combination with synchronous fluorescence spectroscopy was used to examine 28 placentas for the presence of benzo[a]pyrene diol epoxide-DNA adducts, and 10 of these were found to be positive. DNA samples from these placentas were subsequently pooled and subjected to partial enzymatic digestion to oligonucleotide fragments. Concentration of those DNA fragments containing benzo[a]pyrene diol epoxide-DNA adducts was achieved by immunoaffinity chromatography with polyclonal antibodies raised against these adducts. Column eluates were hydrolyzed under mild acid conditions and extracted with an organic solvent. The presence of benzo[a]pyrene-7,10/8,9-tetrahydrotetrol residues in the extracts was determined by HPLC and synchronous fluorescence spectroscopy and was confirmed by GC/MS. The results unequivocally confirm bioactivation and formation of DNA adducts from benzo[a]pyrene in human placenta in vivo and establish a methodological approach to direct measurement of carcinogen-DNA adducts that are formed as a result of human environmental exposure.

7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide↗
PubMed1987

ICU pneumonias: a multi-institutional study.

We conducted a prospective multi-institutional study of nosocomial and community-acquired pneumonias in 1378 patients admitted to the ICUs of six hospitals. We also investigated 1005 of these patients who were intubated and mechanically ventilated for a reason other than pneumonia, the risk of developing pneumonia, and the relationship between the incidence of pneumonia and the length of time during which the patients were mechanically ventilated. A bacteriologic diagnosis was made in 38% of the nosocomial and 21% of the community-acquired pneumonias. The total mortality rate was 40%; 47% of the patients with nosocomial and 17% of the patients with community-acquired pneumonias died. Because it was difficult to make an etiologic diagnosis in two-thirds of the cases, the treatment had to be based on an assumed causative organism.

Adult↗
PubMed1987

Influence of single and double immunomagnetic depletion on the hemopoietic capacity of marrow in patients with advanced neuroblastoma submitted to autologous bone marrow transplantation.

Eighteen marrows from 16 patients with advanced neuroblastoma were submitted to a single or double immunomagnetic depletion procedure to purge them of tumor cells. Analysis of results showed that the CFU-GM recoveries were 59% +/- 16 (SE) and 33% +/- 16 after one or two cycles of incubation with microspheres. This led to yields of 7.8 x 10(4) and 4.1 x 10(4) CFU-GM available per kg body weight, respectively. Successful engraftment was demonstrated in all evaluable patients. However, some patients had delayed hematologic recoveries, particularly for platelets.

Antibodies, Monoclonal↗
PubMed1983

Erroneous interpretation of pulmonary capillary wedge pressure in massive pulmonary embolism.

Pulmonary capillary wedge pressure (WP) values obtained after catheterization of a pulmonary artery (PA) totally occluded by thrombus may be erroneously interpreted. The left lower lobe PA was catheterized in 13 anesthetized dogs. Measurements of mean pulmonary artery pressure (MPAP) and WP were performed before and after total occlusion of the PA by a clamp located 1 cm from the tip of the catheter. There was a difference between pulmonary artery occluded pressure (PAoP), MPAP, and WP, both in normovolemic and overload conditions (p less than .01). The PAoP was not equivalent either to WP or to MPAP. In massive pulmonary embolism, WP may not reflect left ventricular end-diastolic pressure (LVEDP).

Animals↗