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Biomedical subjects

E Jimenez

Publications and source records attributed to E Jimenez.

106 records · Page 6Linked to original sources
PubMed1983

Comparison of central nervous system prophylaxis with cranial radiation and intrathecal methotrexate versus intrathecal methotrexate alone in acute lymphoblastic leukemia.

In acute lymphoblastic leukemia (ALL), central nervous system (CNS) prophylaxis with cranial irradiation plus 5 doses of intrathecal methotrexate (i.t. MTX) reduces the incidence of CNS relapse to 7%-15%. However, increased evidence of CNS delayed toxicity started to be recognized as CT scan abnormalities and neuropsychologic alterations, mainly in children. Two questions were analyzed in the present report: (1) Will further doses of i.t. methotrexate and dexamethasone (i.t. MTX-DMT) decrease the incidence of CNS relapse in patients treated early in remission with cranium irradiation plus i.t. MTX-DMT even more? (2) Is i.t. MTX-DMT given during induction and maintenance equally as effective as cranium irradiation plus i.t. MTX-DMT? A randomized study was designed to answer the first question. Incidence of primary CNS relapse in i.t. MTX-DMT-treated patients with a WBC count less than 50,000 was 11% (15 of 135 patients) and was 11% (17 of 150) in the untreated group. In patients with a WBC count greater than 50,000, it was 16% (6/37) in the treated group and 19% (6/31) in the control group. No difference was observed according to treatment in both prognostic groups. Patients in this study were retrospectively compared with a consecutive protocol in which patients received 3 doses of i.t. MTX-DMT alone during induction plus 3 doses weekly during the first month of remission and every 3 mo thereafter. The incidence of primary CNS leukemia at 60 mo in patients with a WBC count less than 50,000 was 20% in the irradiated group and 32% in the group with i.t. MTX-DMT alone. This difference was not significant. However, the relapse-free survival at 60 mo was 26% and 41%, respectively, (p less than 0.0005). The incidence of primary CNS relapse in patients with a WBC count more than 50,000 at 48 mo was 28% in the irradiated group and 42% in the nonirradiated group. The difference was not significant. The duration of complete remission was similar, remaining at 15% and 16% of patients disease-free at 48 mo, respectively. We conclude that (A) after cranial irradiation plus i.t. MTX-DMT X 5, the use of additional doses of i.t. MTX-DMT is not of further benefit in preventing CNS relapse; (B) the use of i.t. MTX-DMT alone compares similarly with cranial irradiation plus i.t. MTX-DMT in the incidence of CNS relapse; and (C) relapse-free survival and survival in patients with a WBC count less than 50,000 were significantly longer in those without cranial irradiation.

Adult↗
PubMed1982

[Primary pulmonary hypertension in children].

Case report of an infant who, having been under cardiological observation since birth, developed the clinical symptoms of primary pulmonary hypertension at 12 months. The ECC showed right-ventricular hypertrophy, which progressed rapidly. Heart catheterization confirmed the suspected diagnosis of pulmonary hypertension without cardiovascular malformation. Treatment with isoproterenol and tolazoline was initiated but was unsuccessful: the child died at 18 months. The diagnosis was supported by the histopathology.

Cardiac Catheterization↗
PubMed1980

The epidemiology of Entamoeba histolytica in Mexico City. A pilot survey I.

Stocks of intestinal amoebae isolated from hospital patients in Mexico City and grown in monoxenic culture were compared among themselves and with those already described (SARGEAUNT & WILLIAMS, 1979), using the electrophoretic patterns of four enzymes: glucose phosphate isomerase (GPI), phosphoglucomutase (PGM), L-malate:NADP+ oxido-reductase (oxalacetate-decarboxylating) (ME) and hexokinase (HK). New isoenzyme groups (SARGEAUNT & WILLIAMS, 1979) of all the amoebae, including Entamoeba histolytica have been demonstrated. Amongst these have been found seven more groups of E. histolytica, two new groups of E. hartmanni, one new group of Dientamoeba fragilis and one new group of E. coli. Of the seven new groups of E. histolytica three are known to originate from patients with clinical amoebiasis whilst the remainder are from asymptomatic subjects. Only 11.2% of the 125 isolations were associated with clinical amoebiasis, and these are clearly distinguished from the isolations from asymptomatic patients by their electrophoretic isoenzyme pattern.

Amoeba↗
PubMed1971

Methods for accelerating the fluorescent-antibody test for rabies diagnosis.

The time required to perform the fluorescent-antibody test for rabies was reduced by eliminating acetone fixation of the brain impressions and by incubating the conjugate-impression reaction at room temperature for only 10 min. Elimination of the preliminary acetone fixation had no effect on the diagnosis of impression smears from 246 mammalian brains by immunofluorescence. Staining at 37 C for 30 min and staining at room temperature for 10 min were found to be equally effective in the examination of impression smears from 161 brain samples. The procedure, as modified, shortens the time required for the diagnosis of rabies by immunofluorescence from about 5.5 hr to approximately 45 min.

Acetone↗
PubMed1966

Rate of Glycolate Formation During Photosynthesis at High pH.

The products of C(14)O(2) fixation by Chlamydomonas and Chlorella were studied under conditions most favorable for glycolate synthesis. The highest percentage of the C(14) was incorporated into glycolate in the pH range of 8 to 9. After 1 to 2 minutes as much as 40% of the C(14) was found in glycolate products and only a trace of C(14) was present as phosphoglycerate. Below pH 8 the rate of photosynthesis was much faster, but only a small percent of the C(14) was incorporated into glycolate in 1 or 2 minutes, while a high percent of the C(14) accumulated in phosphoglycerate. C(14) labeling of glycolate even at pH 8 or above did not occur at times shorter than 10 seconds. During the first seconds of photosynthesis, nearly all of the C(14) was found in phosphoglycerate and sugar phosphates. Thus glycolate appears to be formed after the phosphate esters of the photosynthetic carbon cycle.Washing Chlamydomonas with water 2 or 3 times resulted in the loss of most of their free phosphate. When a small aliquot of NaHC(14)O(3) was added to washed algae in the absence of this buffering capacity, the pH of the algal medium became 8 or above and much of the fixed C(14) accumulated in glycolate.

Journal Article↗
PubMedDate not supplied

Endothelial modulation of resting and stimulated vascular tone in the pig capsular testicular artery.

We have investigated the wall tension characteristics and the role of endothelium on vascular tone, at rest and under K+ depolarization, in isolated rings from the pig capsular testicular artery. The active tension reached a maximum that was significantly lower in vessels without endothelium, whereas the passive tension and the Ca2+-dependent myogenic tone were not significantly affected by endothelium removal. Both NG-nitro-l-arginine (L-NOARG, 10(-4) M) and methylene blue (10(-5) M), increased the basal resting tension (BRT) in vessels with endothelium, while indomethacin (10(-6) M) decreased BRT in vessels both with and without endothelium. Either removal of endothelium or treatment with indomethacin (10(-6) M), quinacrine (10(-5) M) or ibuprofen (10(-5) M), significantly depressed the K+ concentration response curve, while dazoxiben (10(-5) M) and SQ 30,741 (10(-5) M) had no effect. L-NOARG (10(-6) M) potentiated the contractile response to K+ in vessels with endothelium, whereas L-NOARG (10(-4) M) was ineffective in vessels devoid of endothelium. These results suggest that a predominating NO release from endothelium, together with a cyclooxygenase-derived vasoconstrictor, modulate vascular tone at rest. In contrast, predominant endothelial release of a cyclooxygenase-derived contractile factor, but different from TXA2, PGH2 or superoxide anions, is induced by K+ depolarization and leads to vasoconstriction.

Animals↗
PubMedDate not supplied

c-myc, c-erb-B2, nm23 and p53 expression in human endometriosis.

We studied the expression of oncogenes and tumor-suppressor genes in human endometriosis in a retrospective pilot study. Sixteen patients with histologically verified pelvic endometriosis at the university-based tertiary care referral center were studied. Immunohistochemical determination of c-myc, c-erb-B2, nm23 and p53 expression in archival, paraffin-embedded pathological samples were used from patients operated upon for pelvic endometriosis. c-myc was expressed in 8/15 cases (53.3%). nm23 was expressed in 7/16 cases (43.7%). c-erb-B2 and p53 reactivity was undetectable in the samples studied. The c-myc oncogene and nm23 are overexpressed in many cases of endometriosis, and may play a still undefined role in its pathogenesis. Immuno-histochemistry is a useful tool for the study of oncogenic activation in this disease.

Biopsy↗
PubMedDate not supplied

[Use of diazepam during labor].

The effect of diazepam has been watched and studied by continuing monitoring of the heart rate of the mother, the fetus and the newborn, as well as by studying the acid-base balance of the mother and the fetus and the newborn after doses of 20 mg of diazepam had been given to 40 normal labouring women. A good calming effect was found in 87 p. % of women and the remainder had an acceptable result. Both in the mother and in the fetus tachycardia resulted from injection of diazepam as well as a lessening in the frequency of changes in the heart rate. These two alterations were statistically significant (p less than 0.01) and appeared very soon after the administration of the diazepam. Later, no other effects could be found in the mother, the fetus or the newborn.

Acid-Base Equilibrium↗
PubMedDate not supplied

[Significance of Doppler blood flow studies in twin pregnancies].

Twin pregnancies are characterized by similar uteroplacental but different fetoplacental haemodynamics at the same gestational age. The aim of this study was to investigate the correlation between Doppler blood flow measurements of fetal vessels and the morphological findings of the placenta, fetal growth and signs of fetal hypoxia. The study group consists of 18 twin pregnancies with operative delivery. In all cases the placenta was examined morphologically. We found similar discordancies in the pulsatility index (PI) or the mean blood flow velocity (Vmean) of the fetal aorta (measurements less than 7 days before delivery) and the birth-weight. In twin pregnancies with operative delivery due to fetal indication in 11 out of 12 cases the twin with suspected hypoxia had a relatively lower Vmean and a higher PI value. The association of pathological blood flow velocity waveforms of the umbilical artery, the fetal aorta and the fetal common carotid artery and histomorphological findings of the placenta could be demonstrated.

Aorta↗
PubMedDate not supplied

Correlation of MDR1 expression and oncogenic activation in human epithelial ovarian carcinoma.

The expression of the MDR1 gene has been shown to correlate with tumor aggressiveness and oncogenic activation both in experimental tumor models and in human clinical specimens In order to verify whether this association also takes place in ovarian carcinoma, we studied tumor samples from 39 patients by means of immunohistochemistry for the overexpression of P-glycoprotein (MDR1), nm23, c-erb-B2 and p53. MDR1 (p = 0.023), nm 23 (p = 0.037) and c-erb-B2 (p = 0.015) were expressed significantly more in specimens from patients with advanced stage of disease. There were no differences in p53 expression between both groups of patients. Furthermore, we found a significant coexpression of MDR1 and nm23 (p = 0.028), and of MDR1 and c-erb-B2 (p = 0.0077). There was no association between the expression of the MDR1 gene and p53. These results parallel those previously reported by us for mammary carcinoma, and seem to indicate that expression of the multidrug resistance gene (MDR1) is inherent to the development of the malignant phenotype in several human tumors.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMedDate not supplied

Co-expression of the MDR1 gene and HSP27 in human ovarian cancer.

Heat-shock proteins seem to play a still undefined role in cancer. One of them particularly, the low molecular weight HSP27, seems to be involved in resistance to chemotherapy. This phenomenon has been reported in breast cancer cell lines, and the aim of this study was to investigate if it also takes place in clinical tumour samples from ovarian cancer patients. We studied ovarian carcinoma samples from 95 patients by means of immunohistochemistry for the overexpression of both the product of the multidrug-resistance gene (P-glycoprotein) and HSP27. The expression of the MDR1 gene in more than 50% of the tumour cells was associated with an almost significantly shorter survival of patients with stage II, III and IV tumours (p = 0.05), although intriguingly not with the response to chemotherapy. Tumours expressing the MDR1 gene, furthermore, also tended to co-express HSP27 (64.9% vs. 42.1%), and this difference was statistically significant (p = 0.026).

ATP Binding Cassette Transporter, Subfamily B, Mem↗