PubMed Health⌕ Search

Biomedical subjects

G Rubio

Publications and source records attributed to G Rubio.

At least 37 records · Page 2Linked to original sources
PubMed1997

Determination of parameters that characterize effector-target conjugation of human NK and LAK cells by flow cytometry.

Effector-target conjugation between different cell populations of human NK cells and K562 tumor cells has been studied from binding isotherms obtained from data of effector (alpha) and target (beta) conjugate frequencies measured by flow cytometry analysis at different effector-to-target ratios. Non-linear and linear regression methods were applied to these isotherms to calculate the binding parameters that characterize the process of conjugation, namely, the maximum effector and target conjugate frequencies, the dissociation constant of the conjugates formed, the binding units and the area under the binding isotherms. The results obtained show that: (1) flow cytometry analysis of effector-target conjugation is faster, unbiased and more suitable than microscopic counting of conjugates, thereby permitting the analysis of larger number of conjugates in shorter times, (2) the binding parameters derived from conjugate frequencies obtained by flow cytometry analysis differ from those obtained by microscopy, (3) the discrepancies between the two methods are due to the presence of several cells engaged in multicellular conjugates that are detected as single particles by flow cytometry and (4) the analysis of population distributions of the conjugates formed at different values of the effector-to-target ratio permit the above discrepancies to be corrected.

Flow Cytometry↗
PubMed1997

Facial nerve palsy produced by plasma cell granuloma.

There are many causes for peripheral facial nerve palsy, such as an isolated phenomenon occurring in a healthy person (Bell's palsy), a manifestation of a systemic illness, or a component of a more widespread neurological disease. Plasma cell granuloma is the proliferation of polyclonal, nonneoplastic plasma cells. Several cases have been reported in the literature in which plasma cell granulomas have affected the brain, lungs, gastrointestinal tract, kidneys, salivary glands, and skin. We report a case of peripheral facial nerve palsy produced by a plasma cell granuloma that was confirmed by histological and immunohistochemical studies.

Journal Article↗
PubMed1997

Phenytoin reduces the contraction of recessive dystrophic epidermolysis bullosa fibroblast populated collagen gels.

Recessive dystrophic epidermolysis bullosa (RDEB) is a group of genetic disorders in which blistering occurs below the basement membrane, in many cases resulting in extensive scar formation, contractures and mitten deformities. Our aim was to compare quantitatively the contraction forces generated by normal and RDEB fibroblats and to investigate the effect of Phenytoin (5,5-diphenyl-2,4-imidazolidinedione, sodium salt; PHT). PHT is an anticonvulsant agent, that causes fibrosis as a side effect. This study utilised conventional untethered fibroblast populated collagen lattice contraction and a quantitative force measurement instrument, the culture force monitor (CFM). The RDEB cell lines were hypercontractile, generating 2.5 times the force of normal fibroblasts, though they appeared morphologically normal. In untethered collagen gels PHT (20 micrograms/ml) significantly reduced contraction of both normal and RDEB fibroblasts over 7 days. Pre-treatment of RDEB cells for 5 days also produced a 40% reduction in contraction as measured in the CFM. One suggested mechanism of PHT action is through inhibition of matrix metalloproteinase activity, but the similar effects of PHT and Colchicine (an inhibitor of microtubule polymerisation) in the CFM, indicate that it may act on contraction through disruption of microfilaments and changes to cell shape. These findings show that isolated RDEB fibroblasts retain the hypercontractile features of many of the patient's lesion sites and imply that local application of PHT may have a therapeutic effect in controlling contraction.

Biomechanical Phenomena↗
PubMed1997

Examination of craniofacial morphology in 10-month to 5-year-old children with cleft lip and palate.

OBJECTIVE: The purpose of this study was to assess craniofacial growth in children from 10 months to 5 years of age with cleft lip and/or palate and to develop a systematic method of cephalometric measurements. DESIGN: A case-control study. SETTING: Craniofacial unit of a teaching hospital for children. PATIENTS: A consecutive series of the first 22 patients with cleft lip and/or palate who underwent early reconstructive treatment [isolated cleft lip (CL) 6; isolated cleft palate (CP) 7; unilateral cleft lip and palate (UCLP) 7; and bilateral complete cleft lip and palate (BCLP) 2] (mean age, 27.9 months) and 22 age- and sex-matched noncleft children. INTERVENTIONS: Lateral cephalometric headfilms of the children were taken using a pediatric cephalostat. MAIN OUTCOME MEASURES: Cephalometric landmarks were measured according to Ricketts cephalometry. RESULTS: As compared with controls, CL patients had a lingual position and inclination of maxillary and mandibular incisors, an increase of interincisal angle and a decrease of incisor overjet, an increase in facial convexity, and a decrease in facial depth and mandible body length. In CP patients, palatal plane inclination and mandible arch were significantly reduced. In UCLP patients, there was a decrease in molar relation and incisor overbite, an increase in interincisal angle, reduced position and inclination of maxillary incisors and inclination of mandibular incisors, an increase in facial convexity, and lower facial height. CONCLUSIONS: Based on the absence of midface growth reduction, these short-term results suggest a tendency toward normal maxillomandibular growth.

Case-Control Studies↗
PubMed1997

Cardiovascular parameters of heroin-withdrawn addicts treated with guanfacine.

Blood pressure and heart rate were monitored in heroin addicts detoxified with guanfacine in an outpatient program. Retrospective analysis of the cardiovascular parameters from the addicts who failed this detoxification during the first 5 days of treatment (they consumed heroin within this period) showed that these patients experienced less hypotension and bradycardia when treated with the alpha 2-agonist than the group of successful patients. Therefore, the relapse to opiate use could be predicted, at least in some patients, by a minimal cardiovascular reaction to guanfacine. Opiate use was followed by significant increases in blood pressure and heart rate, as had happened in previous studies with clonidine-treated addicts. This finding further confirms a similarity between alpha 2-agonists adrenergic and opiates with regard to their cardiovascular effects.

Adrenergic alpha-Agonists↗
PubMed1997

Paclitaxel in platinum-resistant ovarian cancer patients. Argentine Multicenter Taxol Group.

Paclitaxel (Taxol; Bristol-Myers Squibb Company; Princeton, NJ) is an antineoplastic agent that inhibits microtubular function and has shown efficacy in several solid tumors, mainly ovarian tumors, in which 20% to 40% response rates in previously treated patients were observed. We conducted a study to assess survival, response rate, and toxicity associated with paclitaxel treatment in patients with advanced ovarian cancer resistant to platinum therapy. Between September 1994 and November 1996, 38 patients were admitted for study and 37 were evaluable. All had disease progression or relapse within 1 year of receiving platinum-containing first-line chemotherapy. Mean age was 59 years (range, 30 to 75 years), all had bulky disease, and 18 showed increased carbohydrate antigen-125 at admission. They were treated every 3 weeks with paclitaxel 175 mg/m2 as a 3-hour infusion, preceded by standard premedication. Response rate was 51.3%, with a median response duration of 10.0 months and a median survival rate of 16.8 months. Mild to moderate hematologic toxicity was observed with only one episode of grade 4 neutropenia, without fever. Gastrointestinal toxicity was moderate and peripheral neuropathy was mild, except for two patients who had concomitant pathologies or previous treatment, which might have caused some neuropathy. We concluded that paclitaxel given as a 3-hour infusion was easily administered for ambulatory treatment, with mild to moderate toxicity and promising results based on rate and duration of response as well as survival.

Adult↗
PubMed1997

[Carbohydrate deficient transferrin and other markers of alcohol consumption in the general hospital].

BACKGROUND: The ascertainment of patients who consume important amounts of alcohol admitted to a hospital is essential to prevent medical and psychological complications. Carbohydrate deficient transferrin (CDT) is a new marker of alcohol consumption which requires validation in the hospital setting. METHODS: The values of carbohydrate deficient transferrin (CDT), glutamic oxalacetic transaminase (GOT), gamma glutamil transpeptidase (GGT) and mean corpuscular volume (MCV) were measured in 101 consecutive patients admitted to the Internal Medicine and Surgery Departments. Considering amounts higher than 60 g/day of ethanol for male patients and higher than 40 g/day for female patients as risk consumption, the values for sensitivity, specificity and area under the curve were calculated for the different biological tests. RESULTS: Twenty-six percent of patients reported a consumption of risk. The sensitivity of the tests were lower than 50% and specificities higher than 77%. CDT had the lowest sensitivity (15%) but it was very specific (98%). CDT had a better sensitivity among women than among men. None of the tests had an area under the curve with adequate efficiency levels. CONCLUSIONS: CDT among the hospitalized patients and other biological markers of alcohol consumption have a low efficiency.

Adult↗
PubMed1996

Conjugation between cloned human NK cells (H7.8) and K562/MOLT4 tumor cell systems: saturability, binding parameters, and population distribution of conjugates.

Effector-target conjugation between cloned NK(H7.8)-K562 and NK(H7.8)-MOLT4 tumor cells has been studied from binding isotherms. Nonlinear and linear regression methods were used to calculate the maximum effector and target conjugate frequencies as well as the dissociation constant of the conjugates formed. The results obtained show there is an enhancement of the effector-target saturability and effector-target affinity in comparison with the values previously observed for polyclonal NK effector cells. Population distributions revealed that different types of conjugates were formed as the effector-to-target ratio was changed in the NK(H7.8)-K562 and NK(H7.8)-MOLT4 tumor cells. In both cases conjugates where one effector cell was bound to several target cells and conjugates with one target cell bound to several effector cells were found. At all values of R the prevailing conjugates were those with one effector cell bound to one target cell.

Cell Communication↗
PubMed1996

Adhesion, invasion and intracellular replication of Salmonella typhimurium in a murine hepatocyte cell line. Effect of cytokines and LPS on antibacterial activity of hepatocytes.

Elimination of pathogenic microorganisms in the liver may be an important effector mechanism in host defenses. In this paper we describe the adhesion, invasion and multiplication of Salmonella typhimurium in a murine embryonic hepatocyte cell line (ATCC TIB-73). Monolayers of hepatocytes treated with recombinant IFN gamma, IL1 beta, and LPS exhibit antibacterial activity against intracellular Salmonella. The dynamic of the infection process in stimulated vs unstimulated hepatocytes was determined by counting the number of survival bacteria in the cell monolayers at 4 and 28h after gentamicin was added to the infected cells. Salmonella typhimurium is able to adhere, invade and replicate inside the hepatocytes. The maximum number of cell-associated bacteria is approximately 15 bacteria per cell, whereas the invasive capacity of Salmonella is 0.003 bacteria per hepatocyte. Stimulated cultures display antibacterial activity compared to unstimulated controls. The antibacterial activity does not seem to be mediated by nitric oxide (NO) since inhibition of NO production by using NG-Monomethyl-L-Arginine did not revert the antibacterial activity. Also, high amounts of NO induced by adding L-Arginine to the cell cultures did not enhance hepatocyte antibacterial activity.

Animals↗
PubMed1996

[Parasitic delirium in patient with multiorganic pathology: a complex situation].

Delusion of parasitosis is often observed in people who usually take psychoactive drugs. Moreover, it can be present in infectious diseases or tumours of the central nervous system, metabolic disorders, deficiency and states systemic disorders, such as Systemic Lupus Erythematosus (SLE). The neuropsychiatric manifestations in SLE patients are common and constitute one of the criteria for the classification of SLE. Presentation as an acute organic mental syndrome is a clinical emergency and it is usually required the admission in the hospital. We report a case of delusion of parasitosis in a middle age woman diagnosed of SLE several years before and with previous corticosteroid therapy, right temporal arachnoid cyst, chronic Lyme disease and hypothyroidism. We analyse the different role of each pathology and the clinical practice difficulties in the management of these disorders.

Arachnoid Cysts↗
PubMed1995

Differential expression of DNA topoisomerases in non-small cell lung cancer and normal lung.

UNLABELLED: DNA topoisomerases are ubiquitous nuclear enzymes, and important targets of cancer chemotherapy. Expression of topoisomerase genes is often correlated with in vitro chemosensitivity. We investigated the expression of the topoisomerase genes in normal lung and non-small cell lung cancer. Expression of topoisomerase II-alpha, topoisomerase II-beta, and topoisomerase I genes has been assessed in tumor samples of 60 patients who underwent operation for a non-small cell lung carcinoma, by RNase protection assay, and by immunohistochemistry. The expression of topoisomerase II-alpha gene was either undetectable or very low in normal lung, while most NSCLC expressed readily quantifiable levels of this gene. No alteration of the topoisomerase II-alpha gene was found by Southern blotting in the NSCLC samples. In contrast to topoisomerase II-alpha, topoisomerase II-beta was expressed in most normal as well as in tumor tissue samples, at a similar level. The levels of expression of both topoisomerase II isoforms was lower than that of human lung cancer cell lines. The results of the topoisomerase II mRNA expression were confirmed by immunohistochemistry. Whereas topoisomerase II-alpha staining was mainly limited to the nucleus, staining with topoisomerase II-beta antibody was exclusively observed in nucleoli. Topoisomerase I was localized in the nuclei and expression was mainly limited to tumor cells. By RNase protection, topoisomerase I expression in NSCLC samples was in the range of that of human lung cancer cell lines. The expression of the topoisomerase genes did not seem to be coordinated. In tumor cells, there was a positive association between expression of topoisomerase II-alpha and Ki-67, a marker of cell proliferation, as assessed by immunohistochemistry, but not with topoisomerase II-beta or topoisomerase I. Clinical characteristics of the patients, and their survival did not appear to be correlated to the level of expression of any of the topoisomerase genes, although a trend towards a shorter survival was observed in patients whose tumors expressed relatively high topoisomerase II-alpha mRNA levels. IN CONCLUSION: (1) the two isoforms of topoisomerase II are differentially expressed in normal lung and NSCLC cells; (2) higher topoisomerase II-alpha expression is associated with higher cell proliferation in NSCLC; (3) the expression of topoisomerase II-alpha and topoisomerase I, but not of topoisomerase II-beta, was higher in tumor cells compared to normal lung. Given the differential expression of topoisomerases in normal lung and tumors, research of more potent and specific topoisomerase inhibitors might prove beneficial in non-small cell lung cancer. Immunohistochemistry may be indicated in prospectively investigating the correlation between expression of topoisomerases and results of chemotherapy treatment.

Aged↗
PubMed1995

Differential expression of the c-kit proto-oncogene in germ cell tumours.

The c-kit proto-oncogene product and its ligand stem cell factor play an important role in haematopoiesis, spermatogenesis, and melanogenesis. Using an anti-c-kit antiserum raised against a synthetic peptide, we studied the immunohistochemical expression of the c-kit gene product in 60 germ cell tumours (GCTs) (53 testicular, 7 extragonadal), derived from primary GCTs in 45 cases and metastatic tumours in 15 cases. Twenty-eight out of 28 seminomas showed c-kit membranous staining in the majority of cells. A similar pattern of expression was seen in intratubular germ cell neoplasia. Nine out of 29 (32 per cent) non-seminomas displayed cytoplasmic, but not membranous, c-kit immunoreactivity in occasional cells. In three mixed GCTs, c-kit expression was limited to the seminoma component. In normal testis, c-kit expression was observed in some basal tubular cells, corresponding to undifferentiated spermatogonia. These results suggest a role for c-kit in the oncogenesis of GCT, where down-regulation of c-kit might be a critical step during progression from seminomas to non-seminomas. Immunohistochemical analysis of c-kit should be considered as a diagnostic aid for GCT and in particular may be helpful in the identification of certain extragonadal seminomas.

Adolescent↗
PubMed1995

Presence and isotype of anti-ganglioside antibodies in healthy persons, motor neuron disease, peripheral neuropathy, and other diseases of the nervous system.

Antibodies of the IgM, IgG and IgA class against GM1, asialo-GM1, GD1b and GM2 gangliosides were determined in the sera of patients with motor neuron disease (MND), peripheral neuropathy, other neurological diseases (OND) and healthy individuals. Antibodies of the three immunoglobulin classes were present in healthy persons. MND patients did not differ from OND or controls in anti-GM1 titers of the three isotypes. In the group of peripheral neuropathy, no elevations of antibody titers were observed in patients with sensory or sensory-motor neuropathy; however, four out of 12 patients with the motor variety had very high levels of IgM or IgG antibodies. Two of these four patients also had increased titers of IgA antibodies, but no patients exhibited high titers restricted to this isotype.

Adult↗