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Biomedical subjects

J García

Publications and source records attributed to J García.

At least 181 records · Page 10Linked to original sources
PubMed1997

[Unilateral renal agenesis associated with pelvic renal ectopy].

OBJECTIVE: To describe a rare case of right renal agenesia and left pelvic ectopy. To our knowledge, only 10 such cases have been reported in the world literature. METHODS: A 76-year-old male patient who consulted for irritative prostatic syndrome is described. Patient evaluation included IVP and CT. RESULTS: IVP revealed the absence of the right kidney in addition to an anomalous position of the left kidney. The foregoing findings were confirmed by CT. CONCLUSION: This uncommon congenital anomaly is essentially asymptomatic and is generally diagnosed in infants through its complications. In the case described herein, however, this anomaly had been incidentally detected during IVP and CT assessment of a 76-year-old patient who had consulted for irritative prostatic syndrome.

Abnormalities, Multiple↗
PubMed1996

High-dose systemic interleukin-2 therapy in stage IV neuroblastoma for one year after autologous bone marrow transplantation: pilot study.

Despite intensified chemotherapy protocols, including autologous bone marrow transplantation (ABMT), stage IV neuroblastoma has a poor prognosis, and modern therapeutic trends are aimed at the eradication of minimal residual disease, which is though to be the main factor leading to relapse. In this pilot study, we report the systemic administration of high doses of interleukin-2 after ABMT in four patients. Five day cycles of IL-2 at a dose of 18 x 10(6) IU/m2/day were administered at variable time intervals as frequent as it was necessary to maintain the levels of natural killer (NK) cytotoxic activity higher than the median control value (40 LU/ml blood) throughout 1 year from the start of first IL-2 treatment. After IL-2 infusion, NK and LAK activities increased significantly (median 742 x 10(-3) LU/ml blood and 186.8 x 10(-3) LU/ml blood, respectively). Toxicities were transient and no life-threatening complications were observed. Fever, anorexia, skin rash and enlarged liver were always present. Anaemia, thrombocytopenia, leukocytosis, lymphocytosis and and eosinophilia occurred following most of the IL-2 courses. Although the small number of patients does not allow an estimation of the immunomodulatory-antineoplasic effects of IL-2, the results seem promising for the management of neuroblastoma patients.

Adrenal Gland Neoplasms↗
PubMed1996

An extended x-ray absorption fine structure study of the high-affinity cation-binding site in the purple membrane.

The structure of the high-affinity cation-binding site of bacteriorhodopsin was studied using extended x-ray absorption fine structure techniques. The results obtained for Mn2+ in aqueous solution and for the complex BR-Mn2+ (1:1 molar ratio) show great similarities, suggesting that Mn2+, when bound to this site, is coordinated with six atoms of oxygen, forming an octahedral disposition. The interatomic distance between the atoms of oxygen and the Mn2+ was found to be 2.17 A for the complex BR-Mn2+, similar to Mn2+ in solution (2.15 A). In addition, the absence of any other peak at greater distances in the Fourier-transformed spectrum indicates that neither phosphorus nor sulphur atoms are present in the second coordination shell. This suggests that this binding site is located in the protein, discarding the proximity of lipid polar headgroups.

Binding Sites↗
PubMed1996

Contraceptive patterns among women and men in León, Nicaragua.

The aim was to study the contraceptive patterns among men and women in León, Nicaragua. A questionnaire about sexual, contraceptive, reproductive and socioeconomic issues was directed to 7,789 households including 22% of all women of the municipality aged 15-49 years (n = 10,867). A subsample of 388 men and 413 women aged 15-49 years was drawn at random. Refusals were less than 2%. Private interviews revealed that among fertile women who had been sexually active within the last three months, non-pregnant and wishing to avoid pregnancy, 77% were contracepting. Female sterilization was the most common contraceptive method (39%), followed by intrauterine device (16%). Even though around 60% of women at some time had tried oral contraceptives, only 13% of contraceptors used them currently. The rhythm and interruption methods together constituted only 4%. Condom use was low and mainly occasional. Contraceptive use in sexually active women aged 15-44 years was lower among those having lower education, living in rural areas, and living under poverty conditions. The predominance of female sterilization and the occasional condom use-mainly reported by men-reflects a situation of relative male control over contraception and reproduction. This probably originates from "machista" values where men having many children with different women are considered strong. There was also a significantly higher use of contraceptives among the better-off women and men compared with the extremely poor. The situation of many poor women, in a country with limited contraceptive services, is worrying considering that abortion is illegal and the threat of HIV epidemic is growing. The situation for adolescents is particularly problematic with low experience in contraceptive use.

Adolescent↗
PubMed1996

[Teachers' attitudes toward smoking prevention at schools].

Teenage smoking continues to present a significant public health problem. Children begin to smoke in elementary and middle school, although consumption is highest during university studies. In spite of their limitations, school-based campaigns are the most effective weapons against smoking. Spanish educational authorities have developed an interdisciplinary anti-smoking curriculum for health education. In practice, however, the curriculum is not usually implemented. An understating of teachers' attitudes toward such campaigns can lead to their better design, contributing to greater cooperation and better outcome. We therefore surveyed teachers participating in the School-based Smoking Prevention Plan during 1993-1995. Teachers had a generally favorable opinion of the campaign and wanted to continue it; they were well disposed to cooperate more actively with the physicians who carried it out.

Adult↗
PubMed1996

Anomalous retinoblastoma protein expression in Sternberg-Reed cells in Hodgkin's disease: a comparative study with p53 and Ki67 expression.

Retinoblastoma (Rb) tumour-suppressor protein plays a critical role in cell cycle control. Rb inactivation is a frequent phenomenon in tumours of different cell lineages, in which the absence of Rb protein has been considered to be a marker of Rb disregulation. We used modern immunohistochemical techniques to study the expression of Rb protein in a large series of 130 patients with Hodgkin's disease. Simultaneously, Western blot was used to analyse a more restricted group (12 patients) to confirm the immunohistochemical results and to clarify the phosphorylation status of Rb protein. As the level of Rb expression varied according to cell cycle stage, we also performed immunostaining for Ki67, a protein present in proliferating cells. To make comparison possible, we first characterised the amount and phosphorylation status of Rb protein in reactive lymphoid tissue and phytohaemagglutinin (PHA)-stimulated lymphocytes. The presence of p53 in Sternberg-Reed cells was also included in the study, as both proteins (p53 and Rb) have been found to be closely associated in cell cycle control. PHA-stimulated peripheral blood lymphocytes showed a parallel increase in Rb and cell cycle progression, together with progressive Rb phosphorylation. In reactive lymphoid tissue there was also a clear correlation between Rb expression and the Ki67 proliferation index (R = 0.96, P = 0.038). When analysing Hodgkin's disease samples, a clear difference emerges between cases of nodular lymphocyte predominance, which preserve the relationship between Rb and Ki67 expression (r = 0.8727, P = 0.000), and classical forms of Hodgkin's disease (nodular sclerosis and mixed cellularity), which display a strong deviation from this pattern. Two main anomalies were found: (1) One group of 21/130 cases with partial or total loss of Rb protein expression, which could reflect the existence of genetic alterations, or an altered transcriptional or translational regulation of Rb gene. (2) Another group with an abnormally high Rb/Ki67 ratio, which could support conflicting interpretations: (i) excess Rb protein for controlling cell cycle progression; or (ii) adhesion of Rb protein to other cellular or viral proteins, such as p53 and MDM2. The results of this study indicate an anomalous pattern of expression of Rb in classical forms of Hodgkin's disease, and suggest the possibility of undertaking functional studies (E1A adhesion, p16 expression) with the aim of better characterising the status of Rb protein, and correlating these findings with clinical course in Hodgkin's disease patients.

Hodgkin Disease↗
PubMed1996

Ca2+ release from the sarcoplasmic reticulum compared in amphibian and mammalian skeletal muscle.

Puzzled by recent reports of differences in specific ligand binding to muscle Ca2+ channels, we quantitatively compared the flux of Ca2+ release from the sarcoplasmic reticulum (SR) in skeletal muscle fibers of an amphibian (frog) and a mammal (rat), voltage clamped in a double Vaseline gap chamber. The determinations of release flux were carried out by the "removal" method and by measuring the rate of Ca2+ binding to dyes in large excess over other Ca2+ buffers. To have a more meaningful comparison, the effects of stretching the fibers, of rapid changes in temperature, and of changes in the Ca2+ content of the SR were studied in both species. In both frogs and rats, the release flux had an early peak followed by fast relaxation to a lower sustained release. The peak and steady values of release flux, Rp and Rs, were influenced little by stretching. Rp in frogs was 31 mM/s (SEM = 4, n = 24) and in rats 7 +/- 2 mM/s (n = 12). Rs was 9 +/- 1 and 3 +/- 0.7 mM/s in frogs and rats, respectively. Transverse (T) tubule area, estimated from capacitance measurements and normalized to fiber volume, was greater in rats (0.61 +/- 0.04 microns-1) than in frogs (0.48 +/- 0.04 micron-1), as expected from the greater density of T tubuli. Total Ca in the SR was estimated as 3.4 +/- 0.6 and 1.9 +/- 0.3 mmol/liter myoplasmic water in frogs and rats. With the above figures, the steady release flux per unit area of T tubule was found to be fourfold greater in the frog, and the steady permeability of the junctional SR was about threefold greater. The ratio Rp/Rs was approximately 2 in rats at all voltages, whereas it was greater and steeply voltage dependent in frogs, going through a maximum of 6 at -40 mV, then decaying to approximately 3.5 at high voltage. Both Rp and Rs depended strongly on the temperature, but their ratio, and its voltage dependence, did not. Assuming that the peak of Ca2+ release is contributed by release channels not in contact with voltage sensors, or not under their direct control, the greater ratio in frogs may correspond to the relative excess of Ca2+ release channels over voltage sensors apparent in binding measurements. From the marked differences in voltage dependence of the ratio, as well as consideration of Ca(2+)-induced release models, we derive indications of fundamental differences in control mechanisms between mammalian and amphibian muscle.

Animals↗
PubMed1996

Interleukin-2 in neuroblastoma: clinical perspectives based on biological studies.

Stage IV neuroblastoma (NB) is a disease with a poor prognosis. Chemotherapeutical intensification and hematological rescue with autologous bone marrow transplantation (ABMT) achieve some complete remissions (CR), but most patients relapse during the first year. Immunotherapy could be an alternative in this situation of high risk of relapse due to residual disease and ABMT-related immunodepression. Ten stage IV NB patients in CR or very good partial remission have been treated with recurrent 5-day cycles of high doses of Interleukin-2 (IL2) after ABMT throughout one year (usually 5-6 cycles). Natural killer (NK) and lymphokine-activated killer (LAK) cytotoxic activities, as well as phenotype and number of circulating NK cells were determined, before and after each course of IL2 treatment. The effects promoted by IL2 varied during treatment: early cycles of IL2 induced a great extent of cell expansion, mainly on CD3-/CD16-/CD56+bright and CD8+dim cell phenotypes; conversely, late courses of IL2 promoted higher NK cytotoxic activity but a lesser increase on circulating NK cells. The induction of LAK activity did not significantly differ from early and late IL2 treatments. Clinical results are still inconclusive due to the small number of patients. The median follow-up of patients treated with IL2 is 24 months and the disease free survival (DFS) probability is 0.80 +/- 0.12 vs 0.16 +/- 0.15 from a historical control with identical treatment, but in the absence of IL2 treatment (p < 0.005). IL2 treatment-related toxicity was mild and no interruption of the treatment was required. Extremely accurate hydric control was carried out to avoid, as much as possible, the consequences of vascular leak syndrome, one of the most important toxic effects of IL2 treatment. The results presented here suggest an evolution of NK activity during IL2 treatment after ABMT, which should be taken into account for the designing of new immunotherapeutical protocols and opens a promising perspective in treatment of stage IV neuroblastoma.

Bone Marrow Transplantation↗