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Biomedical subjects

J López

Publications and source records attributed to J López.

At least 55 records · Page 3Linked to original sources
PubMed2000

Patient dose from barium procedures.

The objective of this work was to estimate patient doses (dose-area product, organ dose, effective dose and entrance surface dose) for barium procedures. A total of 175 procedures, in 175 patients, for five different examination categories was analysed. Dose-area product was determined using a transmission ionization chamber. Organ dose and effective dose were assessed using a knowledge of the examination and the software. For all patients, the contribution of fluoroscopy to the total dose was greater than that from radiography. Dose-area product from double contrast barium enema, enteroclysis and intestinal tract procedures was higher than that obtained for the other procedures. The average effective dose was 1.04 mSv and 13.99 mSv for oesophageal tract and enteroclysis examinations, respectively. Entrance surface dose in the oesophageal tract was 16 mGy, 10 times lower than for the other four procedures. Patient dose reduction in barium procedures may be achieved by improved training of resident radiologists, senior radiologists and other specialists in radiation protection.

Adult↗
PubMed2000

Brush-like cells within bronchial epithelia of chicken lung (Gallus gallus).

The secondary and primary (mesobronchus) bronchi of chicken lung are lined by a typical respiratory epithelium: pseudostratified columnar ciliated with goblet cells. Up to date, four constituting epithelial cell types have been identified: ciliated, mucosecretory, basal and endocrine cells. In this study a putative new epithelial cell type, the brush-like cell, is described. The avian brush-like cells have only been found in the bronchial epithelia but never in the gas-exchange areas. They are scattered among the other epithelial cells, mainly ciliated cells, and their number is extremely low. The characteristic morphological feature of these cells is an apical protruding cytoplasm with microvilli. This cell type is similar to that found in the lung of some mammalian and non-mammalian species. The functional role of these cells is not yet clear; they could carry out absorptive processes.

Animals↗
PubMed2000

Copper sensitivity in dorsal hippocampus slices.

The action of copper on the pyramidal neurons in CA1 of the hippocampus is little understood. Our main aim was to study the possible interaction of copper on the synaptic network in CA1 pyramidal neurons. We used Wistar rats hippocampus slices in a recording chamber. The population response ("population of spikes") collected by an extracellular micropipette under baseline conditions served as control. Copper, GABA, bicuculline and picrotoxin were delivered in different experimental conditions to the slice. One, 10 and 100 microM of copper concentration decreased significantly the amplitude and duration of the population spikes in relation to the control response. This effect did not show concentration dependency. Copper in bicuculline medium decreased significantly the duration response in relation to the control response and in relation to copper effect in a free bicuculline medium. This phenomenon emphasizes the copper action on the GABA (B) and (C) receptors. Copper in a picrotoxin medium increased significantly the excitability of the response. This new effect suggests that copper acts on non-GABA receptors, an effect that could be detected when the GABA receptors were inactivated. As a result of these findings it appears that, under our experimental conditions, copper generated transient sensitivity changes in pyramidal neurons of CA1 dorsal hippocampus.

Action Potentials↗
PubMed2000

Unrelated donor bone marrow transplantation as treatment for chronic myeloid leukemia: the Spanish experience. The Chronic Myeloid Leukemia Subcommittee of the GETH. Grupo Español de Trasplante Hemopoyético.

BACKGROUND AND OBJECTIVE: To analyze the results of unrelated bone marrow transplantation (UDBMT) as treatment for chronic myeloid leukemia (CML) in Spain. DESIGN AND METHODS: Eighty-seven consecutive UDBMT performed in 9 centers between October 1989 and February 1998 were evaluated. This represents more than 95% of UDBMT for CML performed in adult transplant centers in Spain during this period. The patients' median age was 31.5 years (range, 12-49). The median interval from CML diagnosis to UDBMT was 30 months (range, 3-160). Seventy-nine percent of transplants were performed during the first chronic phase (1CP). RESULTS: Actuarial probability of survival and disease-free survival at 4 years for the whole series was 24% (95% confidence interval [CI]: 14%-34%) and 20% (CI: 10%-30%), respectively. The cumulative incidence of relapse and transplant-related mortality (TRM) was 7% (CI: 4%-10%) and 71% (CI: 60%-82%), respectively. The main causes of death were graft failure (n=7), infection (n=23), and graft-versus-host disease (GvHD) (n=25). The actuarial probability of acute GvHD grade II-IV and grade III-IV was 56% (CI:46%-66%) and 36% (CI: 26%-36%), respectively. The cumulative incidence of extensive chronic GvHD was 18% (CI: 9%-27%). Univariate analyses showed that the pre-transplant factor with the highest influence on survival was disease status at transplant (30% in 1CP vs. 0% in advanced phases; p=0.0001). Other pre-transplant factors influencing survival among patients in 1CP were: patient's age (older than 30 years 11% vs. 48%), interval diagnosis-transplantation (longer than 2 years 17% vs. 55%), donor type (HLA, B, DRB1 identical 32% vs. 25%), CMV serologic status (donor and recipient negative 63% vs. 24%), year of transplantation (before 1995 19% vs. 40%), and conditioning regimen (cyclophosphamide plus total body radiation 40% vs. 16%). The main risk factors had a cumulative effect on survival. Thus, probability of survival ranged from 66% (CI: 39%-93%) in patients in 1CP, under 40 years of age, transplanted from an HLA, A, B, DRB1 identical donor during the first two years after diagnosis, to 0% in those with three or more risk factors. INTERPRETATION AND CONCLUSIONS: This experience shows that UDBMT used to have a high TRM that has progressively decreased along the years. At the present time, the results are encouraging, particularly when UDBMT is performed under favorable conditions.

Actuarial Analysis↗
PubMed2000

[Parathyroid cysts. Their differential diagnosis from thyroid pathology. A report of 2 cases].

Parathyroid cysts are rare in clinical practice, but, when they appear, they can be mistaken for more common thyroid conditions, that can incidentally be associated with them. We present two cases of parathyroid cysts. One of them was misdiagnosed of thyroid nodule and the other was found in the context of a normo-functioning multinodular goitre. In this last case, the presenting symptoms had raised the suspicion of malignancy. Both of them responded favorably to evacuation of the liquid by means of a puncture-aspiration with a fine needle (PAFN). Our clinical cases show that the diagnosis of parathyroid cyst should be considered in patients with a cervical mass, even if an evident thyroid condition is present. They may be accurately diagnosed by means of PAFN and determining PTH in the cystic liquid, whose characteristics help to predict its side of origin.

Cysts↗
PubMed2000

[Technology for the whole utilization of brewer's yeast in food industry].

A flexible scheme for the fractionation of brewer's yeast was developed. The procedure allows the production of different products such as: dry yeast flakes, dry yeast pills, yeast-extract based table sauce, yeast protein concentrates and soy-like sauce. The investment required for the processing of one ton per day is below 2 million dollars with an overall profitability higher than 53%. Investment is recovered in 0.75 years. The production of food ingredients from yeast upgrades its biomass about 25 fold. Present procedure is compared with other biomass fractionation processes taking into account the utilization of all technological streams where the process becomes environmentally friendly since effluent production significantly lower than similar technologies.

Analysis of Variance↗
PubMed1999

[Reconstitution of peripheral blood lymphocytes in patients treated with bone marrow transplantation: comparison between allogeneic and autologous transplantation].

BACKGROUND: This study compares the immune reconstitution of total T cells, CD4 and CD8 cell subsets, activated T cells, NK cells and B cells in 66 patients who underwent allogeneic or autologous bone marrow transplantation (BMT). PATIENTS, MATERIAL AND METHODS: The reconstitution of peripheral lymphocytes subsets was studied using two-color flow cytometry. The study group consisted of 39 patients who received allogeneic BMT compared with 27 patients who received autologous BMT. Peripheral blood was examined at different time intervals. As a measure of immune function, the response to the mitogen phytohemaglutinin (PHA) was determined. RESULTS: The pattern of recovery of CD3+, CD4+ and CD8+ T cells, as well as the PHA response, was similar for each type of transplant. CD3+CD5- cells were significantly higher following autologous BMT than after allogeneic BMT and during more time. An overexpression of DR on T cells following autologous or allogeneic BMT demonstrates an increasing degree of T-lymphocyte activation. This activated T-cell subset was more stable in patients transplanted with allogeneic BM than in patients treated with autologous BM. The levels of total B cells and CD19+CD5+ B-cells were increased during 2 to 12 months following autologous MBT, remaining normal afterwards; in contrast, the levels of CD19+ lymphocytes and CD19+CD5+B-cells remained higher than normal ranges until 36 months in patients transplanted with allogeneic BM. The percentage of NK cells was significantly increased following both autologous and allogeneic BMT. The highest percentage of NK cells were detected about 2 and 6 months post-transplant in patients treated with autologous or allogeneic BM, respectively. CONCLUSIONS: Allogeneic BMT appears to induce a slight delay recovery of B and NK cells in comparison to autologous BMT. In contrast, T-cells recovery was similar for each type of transplant, although a higher percentage of CD3+CD5- T cells and a faster recovery of activated CD3+DR+ cells to normal levels were observed in patients transplanted with autologous BM.

Adolescent↗
PubMed1999

Uptake of heavy metals to the extracellular and intracellular compartments in three species of aquatic bryophyte.

Shoot tips of Fontinalis antipyretica, Scapania undulata, and Fissidens polyphyllus were maintained for 60 min with solutions containing 0, 1, 10, 50, 100, or 200 ppm of Cd, Co, Cu, Ni, Pb, or Zn. A sequential extraction procedure was then used to estimate the amounts of the corresponding metal, and of K and Mg, in the extracellular compartment (extraction with NiCl(2) or EDTA), the intracellular compartment (subsequent extraction with cold dilute HNO(3)), and the particulate fraction (subsequent extraction with hot concentrated HNO(3)). In most cases more metal was taken up to the extracellular compartment than to the intracellular compartment, while particulate-fraction content was negligible. The relationship between metal concentration in the water and metal content in the extracellular compartment was well modeled with a Michaelis-Menten-type equation. Results suggest that in S. undulata extracellular cation-binding sites have a high metal affinity, while in F. polyphyllus it is relatively low. However, postincubation intracellular contents were highest in the latter species. The ranking of the six metals by amounts taken up into the intracellular compartment was the same for all three bryophyte species. Uptake of heavy metals led to considerable losses of intracellular K (probably due to effects on plasma membrane properties), and of extracellular Mg (probably due to displacement from cation-binding sites). Losses of intracellular K were most marked in S. undulata, followed by F. antipyretica. By contrast, S. undulata was the species from which losses of extracellular Mg were lowest.

Bryopsida↗
PubMed1999

Adrenomedullin in nonmammalian vertebrate pancreas: an immunocytochemical study.

Adrenomedullin (AM) immunoreactive cells have been identified, by immunocytochemical methods, in the endocrine pancreas of seven nonmammalian vertebrate species, belonging to the cartilaginous and bony fish, amphibian, reptilian, and bird classes. The frequency and distribution of the pancreatic AM cells vary among the different animals. In most species, these cells are found scattered mainly among the exocrine component, with a few present in the islet-like structures. The distribution of AM cells in both fish species and Xenopus shows an inverse pattern, since almost every AM cell is located in the islets. In addition, the colocalization of AM with other classical pancreatic peptide immunoreactivities has been analyzed. In numerous cells, AM immunoreactivity did not colocalize with the other hormones, suggesting that AM-producing cells might constitute a new endocrine cell type in the pancreas of many species. Nevertheless, in other cells a species-specific pattern of colocalizations with insulin, somatostatin, glucagon, and pancreatic polypeptide was found, indicating that complex interactions among all these hormones may occur. In conclusion, AM represents a new regulatory peptide of the endocrine nonmammalian vertebrate pancreas, which is possibly involved in the modulation of insulin secretion and other pancreatic functions.

Adrenomedullin↗
PubMed1999

Proadrenomedullin N-terminal 20 peptide (PAMP) immunoreactivity in vertebrate juxtaglomerular granular cells identified by both light and electron microscopy.

The gene for adrenomedullin (AM), a multifunctional peptide hormone, is expressed in mammalian renal tissue and has been shown to stimulate renin release. The exact cell source of this peptide and its gene-related partner, proadrenomedullin N-terminal 20 peptide (PAMP), in kidney is still uncertain. In the present study we have identified PAMP-immunoreactive cells in the kidney of different mammalian species, including man, by light microscopy. In addition, these cells have been further studied in mouse kidney by both light and electron microscopic techniques. At the light microscopic level, PAMP immunolabeling is preferentially located in the subendothelial cells of the enlarged glomerular afferent arterioles, that is, in the juxtaglomerular cells. However, these cells do not show immunolabeling for AM. At the electron microscopic level, the immunostaining appears inside the renin-containing secretory granules of the juxtaglomerular cells. These results confirm the direct link between renin and the AM peptide family and provide a morphological basis for studying the potential modulatory function of AM and PAMP in the control of renin activity. In contrast, neither AM nor PAMP immunoreactivities were detected in the kidney of nonmammalian vertebrates, other than in blood vessels of particular species, providing a new phylogenetic difference in the juxtaglomerular apparatus between mammalian and nonmammalian vertebrates.

Adrenomedullin↗