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Biomedical subjects

E Romano

Publications and source records attributed to E Romano.

At least 37 records · Page 2Linked to original sources

Lipid peroxidation and changes in T lymphocyte subsets and lymphocyte proliferative response in experimental iron overload.

This study was undertaken to investigate the hypothesis that lipid peroxidation might be associated with immunological abnormalities in experimental hemosiderosis. The correlation between the degree of plasma and spleen lipid peroxidation with lymphocyte proliferative response and with the proportion of T lymphocyte subsets was studied in normal and iron overloaded male Sprague Dawley rats. The iron-loading protocol consisted of a total dose of iron-dextran (1.5 mg/Kg body weight) divided in daily i.m. injections over twenty consecutive days. Lipid peroxidation was measured by the thiobarbituric acid assay in plasma and in homogenates of spleen. Plasma lipid peroxide level increased rapidly after i.m. administration of iron-dextran and decreased sharply at 48 h after the last injection. Conversely, a progressive increase of lipid peroxidation in homogenates of spleen was observed in the course of the iron overload protocol, remaining high even at 50 days after initiation of iron-dextran injections. The increase of spleen lipid peroxide levels was associated with decreased lymphocyte proliferative response to Con A in iron overloaded rats. The addition of superoxide dismutase and catalase to lymphocyte cultures reversed the inhibition of the proliferative response, implicating reactive species of oxygen as the causative agents of these alterations. These effects may be related with the enhanced membrane and DNA damage occurring during intracellular and extracellular peroxidation. Negative correlations between helper/cytotoxic ratio and malondialdehyde levels were obtained in blood and spleen during iron administration. These results supports the hypothesis that lipid peroxidation plays a role in the immunological abnormalities observed in experimental hemosiderosis.

Animals↗

Effect of hepatic isoferritins from iron overloaded rats on lymphocyte proliferative response: role of ferritin iron content.

Iron and ferritin impair a variety of immunological functions. To evaluate the effect of ferritin iron content on rat lymphocyte proliferative response, isoferritins that differ in their iron content and isoelectric point (pI) were isolated from iron overload rat livers by ultracentrifugation (isoferritins with high iron content and low pI) or crystallization (isoferritins with low iron content and high pI) methods. Additionally, commercial horse splenic ferritin (with a lower pI and higher iron content than rat isoferritins) was also tested. Proliferative response to Con A was decreased in a dose-dependent manner in all assays in which spleen cells were incubated with rat and horse isoferritins. However, isoferritins with higher iron contents (rat isoferritin obtained by ultracentrifugation and horse ferritin) caused a greater decrease of proliferative response at 5 and 25 micrograms/ml than the others. Rat and horse apoferritins showed no inhibitory effect on lymphocyte proliferative response, suggesting that the effect is due to iron probably through the damaging effect of reactive oxygen species generated by iron released by the isoferritins on lymphocyte functions. Additionally, the role of serum ferritin level on proliferative response was studied in an experimental model of iron overload in rats. An inverse relationship between the proliferative response and serum ferritin levels was observed. Our results suggest that the inhibitory effect of the isoferritins on lymphocyte proliferative response is due, at least partially, to the iron content of this protein and not exclusively to variation in pI as suggested by other authors. These results are in agreement with the possible immunosuppressor role of ferritin in vivo.

Animals↗

[Adsorption of volatile anesthetics on activated charcoal. Efficiency of an experimental filter during low-flow circuit ventilation].

The inclusion of charcoal filters in the anaesthetic low-flow systems contributes to the acceleration of the kinetics of isoflurane (Forane). In fifty-four subjects, scheduled for extra- and intracranial surgery, ventilated with a low-flow system (Ohmeda Excel OAV7750 with rebreathing cassette) with a mean total flow of 0.7 1/min, the experimental charcoal cartridge showed: (a) a good adsorbent power (awakening within 5-6 minutes from the inclusion of the cartridge into the circuit) and (b) efficiency (adsorbent power unchanged until the sixth application). The use of charcoal during low-flow anaesthesia is both useful and economical.

Adolescent↗

Cardiac allotransplantation across the ABO-blood group barrier by the neutralization of preformed antibodies: the baboon as a model for the human.

The baboon, like the human, expresses A and/or B blood group antigens on its tissues. Anti-A and anti-B antibodies are directed against these antigens, the epitopes of which are carbohydrate structures. Portions of these carbohydrates have been synthesized (trisaccharides A and B, respectively). When infused intravenously, the synthetic trisaccharides form a complex with the specific antibodies and neutralize their activity preventing them from binding to the antigen targets on a transplanted organ. In nonimmunosuppressed, hyperimmunized baboons, the continuous intravenous infusion of the specific trisaccharide alone (for 6 days) inhibited rejection of ABO-incompatible cardiac allografts, extending survival from a mean of 19 min (n = 3) to 8 days (n = 2), at which time the grafts failed from cellular (not vascular) rejection. The combination of long-term pharmacologic immunosuppression plus trisaccharide infusion (for periods of 8 to 19 days) extended survival to a mean of > 28 days (n = 4) with one heart functioning > 52 days. Accommodation clearly occurred in three of the four cases. This form of therapy may permit cadaveric organ allotransplantation across the ABO blood-group barrier in the human.

ABO Blood-Group System↗

PUVA-treated psoriatic skin as a model for cutaneous wrinkling assessed by skin replicas.

Psoriatic patients may offer a useful model for PUVA-induced skin wrinkling. This study deals with the changes induced by PUVA therapy on the cutaneous microrelief of psoriatic patients assessed by surface replicas. A non-exposed body area (buttocks) was considered. The microrelief was evaluated by means of replicas analysed by an automatic image analyser. Three groups of patients were considered: 1) 10 psoriatic patients who had been undergoing PUVA treatment for the first time and who had received a total PUVA dose of 200 +/- 20 J/cm2; 2) 16 psoriatic patients in long-term PUVA treatment (> 1000 J/cm2); 3) 13 psoriatic controls whose buttocks had never been affected by psoriasis nor exposed to sunlight or PUVA. The results showed that the number and the entity of the cutaneous crests and furrows had been increased by PUVA therapy. In particular the skin pattern analysis showed significant statistical differences between the second and the third group, while no changes were evident between the first and third group (ANOVA and Tukey test for multiple comparisons). In conclusion, our findings indicate that long-term PUVA therapy causes marked changes in the cutaneous microrelief, that this phenomenon can be measured non-invasively and that the changes observed are dependent on the PUVA-dose energies received.

Adult↗

Identification of alpha-galactosyl and other carbohydrate epitopes that are bound by human anti-pig antibodies: relevance to discordant xenografting in man.

Human anti-pig antibodies were obtained by perfusing pig hearts (n = 4) and kidneys (n = 8) with human AB or O plasma followed by elution with 3 M NaSCN. The antibodies were screened against a panel of 132 synthetic carbohydrates conjugated to bovine serum albumin using an enzyme-linked immunoassay. An anti-immunoglobulin antibody was also used to detect immunoglobulin deposits on pig tissues. Four carbohydrate molecules with a terminal alpha-galactose residue bound all but one of the human anti-pig kidney antibodies and most of the anti-pig heart antibodies. These were: (i) alpha Gal(1-->3)beta Gal(1-->4)beta GlcNac (linear B type 2); (ii) alpha Gal(1-->3)beta Gal(1-->4)beta Glc (linear B type 6); (iii) alpha Gal(1-->3)beta Gal(B disaccharide); and (iv) alpha Gal(alpha-D-galactose). Immunoglobulin deposition was documented post-plasma perfusion in all pig hearts and particularly strongly in all pig kidneys. These results suggest that human anti-pig antibodies are mainly directed against alpha-galactosyl structures. Extracorporeal immunoadsorption of human plasma through columns of the specific synthetic carbohydrate(s) might lead to depletion of anti-pig antibodies and allow discordant xenografting in man. Alternatively, the infusion of the specific carbohydrate(s) for a period of several days might result in neutralization of the anti-pig antibodies and allow accommodation to take place.

ABO Blood-Group System↗

Diaphragmatic function before and after laparoscopic cholecystectomy.

BACKGROUND: Diaphragm dysfunction is a primary cause of ventilatory impairment after upper abdominal surgery. Laparoscopic procedures may result in less dysfunction. To test this, diaphragmatic function was studied in ten healthy adult patients undergoing elective laparoscopic cholecystectomy and in five undergoing laparoscopic hernia repair. METHODS: Respiratory gas exchange, ventilation, and breathing pattern were measured before and 3 h after surgery. Respiratory drive was evaluated from the relationship of P0.1 to end-tidal carbon dioxide (PETCO2) during tidal breathing. Diaphragm contractile function was assessed from maximal transdiaphragmatic pressure (Pdimax), and Pdi during a maximal sniff maneuver (Pdisniff). RESULTS: Oxygen consumption and carbon dioxide production did not change after surgery. Pdimax decreased by more than 50% in the laparoscopic cholecystectomy group, but Pdisniff did not change. Tidal volume and the ratio of inspiratory time over total cycle time decreased by 30% and 13%, respectively, PETCO2 increased by 9%, and minute ventilation did not change. In contrast, there was no variation in ventilatory function in patients undergoing laparoscopic hernia repair. In both groups, P0.1 did not change, which excludes depressed respiratory drive as an explanation for the decreased Pdimax in laparoscopic cholecystectomy. Contractile failure of the diaphragm was discounted as well, because Pdisniff did not change, even in the laparoscopic cholecystectomy group. CONCLUSIONS: Although laparoscopic cholecystectomy does not increase metabolic demands in the early postoperative period, it impairs diaphragm function. The internal site of surgical intervention appears to be the critical variable determining diaphragmatic inhibition after laparoscopic abdominal surgery.

Adult↗

[Charcoal and isoflurane alveolar washout in low-flow circuit].

The inclusion of charcoal filters in anaesthetic low-flow systems contributes to the acceleration of the kinetics of isoflurane (Forane). In twenty subjects, scheduled for extra- and intracranial surgery, ventilated with a low-flow system (Ohmeda Excel OAV7750 with rebreathing cassette) with a mean total flow of 0.7 l/min, awakening was complete within 5 minutes from stopping isoflurane and including charcoal in the circuit. At the awakening, the expiratory concentration of isoflurane was 0.23% (95% confidence intervals: 0.19-0.27%): these values are similar to those of MACawake of isoflurane after fast alveolar washout. The use of charcoal during low-flow anaesthesia makes low-flow systems more flexible in their use; the anaesthetic level is more easily controllable and accidental overdosing of volatile anaesthetics can be immediately removed.

Adult↗

[Rheologic features of erythrocytes in beta-thalassemia minor].

The study assessed the physical characteristics of erythrocytes, viscosity and deformability, measured by a widely described double-filtration method. At the same plasma-cell viscosity was measured and the importance of the rigidity of RBC was evaluated as one of the many forces which interact among the cells and between the plasma and cells. The results showed a marked increase in corpuscular viscosity with reduced deformability, and a significant diminution of plasma-erythrocytic viscosity, whereas total viscosity remained unaltered. These parameters do not correlate with the quantitative pathological alterations of HbA2, but only with RDW-SD. Alterations of the proteic components with a relative increase in the alpha-chains of the erythrocytic membrane are thought to be responsible for these anomalies, by means af the modifications that the excess of alpha-globin causes to the structure and function of erythrocytic membrane; but the quantity of globin is not the decisive factor, and in fact the introduction of the beta-chains are able to correct erythrocytic deformability (Sorensen). Membrane rigidity is probably independent and unrelated to microcytemia, because these erythrocytes, have an excess of surface in relation to their volume, due to the simultaneous alteration of permeability. The diminished plasma-erythrocytic viscosity should be connected with the prevalence of repulsing forces, due to erythrocytic rigidity in relation to the attracting forces due to the proteic fractions which remain unchanged.

Adult↗

[Use of the perceptive stimulative model (PSM, Romano, 1979) as an individual and/or group diagnostic test].

MEP (Spanish acronym for Perceptive-stimulative Model) is a visual test whose nimble and simple administration is apt for both individual and group studies. As a diagnosis complementary instrument, its design has been arranged so that the perceptive material (i.e. geometric outlines) offers information on the degree of integration of ego functions, an analysis of which allows perspectives applicable to diagnosis, prognosis, and therapeutical orientation. At the same time, such analysis enables hypotheses related to the interaction potential of patients involved to be advanced.

Anxiety Disorders↗

[Biomolecules suppressing myelopoiesis].

Hematopoietic stem cells are capable of self-replication and differentiation to lineage-committed progenitor cells. The progenitors proliferate and differentiate to lineage-specific, morphologically recognizable precursors and, finally, to terminal circulating blood cells. These homeostatic mechanisms are regulated by a complex set of interacting growth stimulatory and inhibitory factors that are produced by, or in collaboration with, the tissue's regulatory microenvironment. A number of well-characterized cytokines have been implicated in the negative regulation of hematopoiesis: ferritin H-subunit (HF), lactoferrin (Lf), prostaglandin E (PGE), tumor necrosis factor (TNF), interferon (IFN), transforming growth factor-beta (TGF beta), acetyl-N-Ser-Asp-Lys-Pro (AcSDKP) or thymosin-beta 4, pyroGlu-Glu-Asp-Cys-Lys (pEEDCK), macrophage inflammatory protein-1 alpha (MIP-1 alpha), inhibin, superoxide dismutase (SOD), glutathione (GSH) and others not well-known yet. The role of inhibitors in restraining stem cells from entering the cell cycle and protecting them from the toxic side effects of chemotherapeutic drugs is opening an alternate strategy for the treatment of cancer patients.

Amino Acid Sequence↗

[Cardiovascular effects of a combination of vecuronium and low-dose fentanyl in atropinized and non-atropinized subjects].

The cardiovascular effects of the pharmacologic association of low-dose fentanyl (2 micrograms/kg) and vecuronium (120 micrograms/kg) have been studied in 38 ASA I and II atropinized and non-atropinized patients scheduled for abdominal surgery during induction of anaesthesia with thiopentone or propofol. Whatever the induction agent used, heart rate was consistently reduced in patients not receiving an anticholinergic drug, while it was unchanged in patients treated with atropine intravenously. In non-atropinized patients impressively lower minimum heart rates were observed during induction of anaesthesia with thiopentone. In this last group one patient suffered from a cardiac arrest resolved without sequelae. In patients treated with the association between vecuronium and low doses of fentanyl a pretreatment with atropine is always indicated. Propofol seems to be a better induction agent than thiopentone.

Aged↗

[Model of therapeutic programming in NIDDM diabetes].

The usual choice of therapy in NIDDM diabetes, using oral anti-diabetic compounds, insulin or associated treatments, is based on the results of treatment evaluated empirically using glycemic profiles. As a contribution to the search for a method of choosing a treatment which is based on laboratory data and can restore metabolic equilibrium as quickly as possible using the most efficacious drug at an optimal dose, the paper reports a method of assessing the severity of diabetes according to mean daily glucose concentrations, the degree of instability in relation to the standard deviation, and proposes a sensitivity test to SU which indicates the choice of therapy, together with an insulin sensitivity test which is useful for evaluated the optimal dose. Sensitivity to SU evaluated using this method is not dependent on the degree of severity of diabetes. With regard to its practical use for prescribing treatment the test is highly predictive in positive cases since it is extremely sensitive, while its low specificity does not rule out its use in cases of resistance. The analysis of the results obtained after treatment which was not indicated by the sensitivity tests but based on personal experience and the comparison of the two methods shows that a high percentage of patients received inadequate therapy either due to the prescription of the wrong type of treatment or an incorrect dosage.

Blood Glucose↗

[Monoclonal antibodies and T-cell clones against HLA antigens: production and characterization].

The production and characterization of 21 monoclonal antibodies (MoAbs) resulting from the immunization of Balb/c mice with human lymphoblastoid cell lines is reported. Twelve MoAbs seem to be detecting an HLA polymorphic determinant. Four MoAbs are recognizing monomorphic Class I molecules and another MoAb detects HLA Class II molecules. These results were confirmed by ELISA, cytotoxicity, immunofluorescence and immunoprecipitation. Class and subclass of the MoAbs were assessed by Ouchterlony analysis. Twenty two T cell clones were additionally generated by limiting dilution of lymphocytes stimulated by allogeneic peripheral blood lymphocytes on mixed lymphocyte cultures. Five of these clones were characterized, testing each one for its ability to proliferate in response to a panel of lymphoblastoid cell lines. It was found that they detect the HLA-A9, A23, A29-31, Bw62 and DR7 specificities respectively. These results indicate that the generation of cellular monoclonal reagents is apparently more productive than the generation of murine MoAbs specific for polymorphic variants of HLA antigens.

Animals↗