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Biomedical subjects

E Rocha

Publications and source records attributed to E Rocha.

At least 145 records · Page 8Linked to original sources
PubMed1989

Fibrinogen Sevilla, a congenital dysfibrinogenemia characterized by an abnormal monomer aggregation and a defective plasmin lysis.

A dysfibrinogenemia (fibrinogen Sevilla) was detected in a 64-yr-old woman with no previous history of hemorrhagic diathesis or thrombosis. Thrombin and reptilase times were prolonged. The aggregation of fibrin monomers showed a prolonged latency time with a defective slope although fibrinopeptide release and clot stabilization were found to be normal. Plasmin proteolysis was abnormal with a much slower plasmic degradation in patient's purified fibrinogen. By chromatofocussing the patient's fibrinogen showed an abnormality in pattern elution with a second peak eluting at a pH slightly more basic than the normal one (pH 5.5). Likewise, the isoelectrofocussing of purified non-reduced patient's fibrinogen in agarose gel showed an abnormal distribution in its focussed bands, especially in a group which focussed in a pI-interval between 5.20-5.85. By two-dimensional electrophoresis we did not find any abnormality in the fibrinogen-reduced chains. These results could indicate that the abnormal monomer aggregation, as well as the defective plasmin lysis, could be due to conformational aspects of fibrinogen rather than to structural defects.

Blood Coagulation Disorders↗
PubMed1989

[Coagulation inhibitors in patients with neoplasms].

Mean plasma concentrations of the main inhibitors of blood coagulation antithrombin III (AT III), protein C and protein S were determined in 149 patients with different local and disseminated malignancies. Results were compared with findings in 44 healthy subjects. No statistical significant differences for AT III, protein C and free protein S were found between patients and controls. However, total protein S showed a significant increase in the patient group (p less than 0.0003). None of the parameters analyzed showed differences according to the degree of tumoral activity nor to the tumour localization. We conclude that the main inhibitors of the blood coagulation seem not to play an important role in the pathogenesis of the hypercoagulable state in malignancy. The increased levels in total protein S would indicate endothelial synthesis in response to thrombogenic stimuli.

Adult↗
PubMed1989

Implications of a quasispecies genome structure: effect of frequent, naturally occurring amino acid substitutions on the antigenicity of foot-and-mouth disease virus.

We provide evidence that the quasispecies nature (extreme genetic heterogeneity) of foot-and-mouth disease virus is relevant to the virus evading an immune response. A monoclonal antibody neutralizing the viral infectivity (clone SD6) recognizes an epitope located around a highly conserved sequence (amino acid sequence Arg-Gly-Asp-Leu-Ala at positions 141-145) in the capsid protein VP1 of foot-and-mouth disease virus of serotype C1. The amino acid substitutions Ala-138----Thr and Leu-147----Ile (or ----Val) reduced 100-fold the binding titer of monoclonal antibody SD6 to virions or to VP1. The effect of those substitutions was quantitatively reproduced with synthetic peptides representing the relevant sequences. This provides evidence that the two chemically conservative amino acids replacements--and not other substitutions present in the virus quasispecies--are responsible for the modified interaction with neutralizing monoclonal antibody SD6. The three substitutions were fixed in the viral capsid during one occurrence of foot-and-mouth disease and, furthermore, they are of a type found frequently among independent foot-and-mouth disease virus isolates. The results implicate the extreme heterogeneity of foot-and-mouth disease virus as an important element of viral pathogenesis.

Amino Acid Sequence↗
PubMed1988

Plasminogen activator inhibitor activity in bacterial infection.

It has been experimentally shown that endotoxin induces a marked increase in the levels of a fast-acting inhibitor of plasminogen activator (PAI). The plasma PAI activity and tissue-type plasminogen activator (t-PA) concentrations were measured in 61 patients with human septicaemia and results were compared with those observed in healthy controls. There was a markedly significant increase of PAI in plasma and platelet extracts of patients with septicaemia as compared to controls (p less than 0.0001). No correlation between PAI and endotoxin concentration was observed. Fibrin autography of plasma samples confirmed that activator inhibition was associated with the formation of an enzyme-inhibitor complex. t-PA activity was similar in patients and controls, whereas t-PA Ag showed a significant increase in patients (p less than 0.0001). A significant inverse correlation between t-PA activity and PAI was observed (p less than 0.05). PAI activity was higher in patients with positive blood cultures (p less than 0.0001) and gram-negative septicaemia (p less than 0.0001). There was also a significant increase of PAI levels in patients with disseminated intravascular coagulation (DIC) as compared with patients without DIC (p less than 0.001). We conclude that there is a marked increase of PAI in patients with sepsis. Increased PAI activity may contribute to the pathogenesis of DIC associated with septicaemia.

Adolescent↗
PubMed1988

Preoperative identification of patients at high risk of deep venous thrombosis despite prophylaxis in total hip replacement.

Clinical and laboratory variables were measured on the day before operation in 111 patients who underwent total hip replacement prophylactically treated with acetylsalicylic acid or heparin-dihydroergotamine. Postoperative deep vein thrombosis (DVT) was detected in 16 patients by ascending venography. Stepwise logistic discriminant analysis was used to identify DVT predicting factors. Three such factors, fibrinogen degradation products (FDP), plasminogen activator inhibitor (PA-inhibitor) and tissue type plasminogen activator (t-PA), were found to be significantly associated with DVT and were used to construct a predictive index. The predictive index, I = -2.09 + 0.46 (FDP) + 1.39 (PA-inhibitor) -0.24 (t-PA), was 100% sensitive and 95% specific in the prediction of DVT. This index would allow for identification of those patients in whom routine prophylaxis would be sufficient and for selecting those in whom more effective prophylactic regimens would be necessary.

Adult↗
PubMed1988

Extensive antigenic heterogeneity of foot-and-mouth disease virus of serotype C.

The antigenic behavior of 46 field isolates of foot-and-mouth disease virus (FMDV) of serotype C has been studied with a panel of 24 monoclonal antibodies (MAbs) prepared against FMDV C1 or FMDV C3 Indaial. Reactivities were assayed by immunodot, immunoelectrotransfer blot, and neutralization of infectivity. The epitopes recognized by the 10 nonneutralizing MAbs are conserved in all isolates analyzed. In contrast, extreme antigenic heterogeneity is documented with regard to reactivity with 14 MAbs that, on this basis, define at least 12 epitopes involved in neutralization of FMDV of serotype C. The 31 isolates from South America were divided into 17 distinct antigenic groups and the 15 isolates from Europe into 7 groups. Lack of correspondence between antigenic composition and the origin--date and place of isolation--of the viruses was noted in several instances. Antigenic heterogeneity is shown among epidemiologically closely related FMDVs. In most--but not all--cases tested, a good correlation was found between binding of a neutralizing MAb to virions and its ability to neutralize infectivity. It is concluded that variation of epitopes involved in neutralization of FMDV is extensive among subtypes of serotype C and also among individual isolates of one subtype.

Animals↗
PubMed1988

Coevolution of cells and viruses in a persistent infection of foot-and-mouth disease virus in cell culture.

Virus and cells evolve during serial passage of cloned BHK-21 cells persistently infected with foot-and-mouth disease virus (FMDV). These carrier cells, termed C1-BHK-Rc1 (J.C. de la Torre, M. Dávila, F. Sobrino, J. Ortín, and E. Domingo, Virology 145:24-35, 1985), become constitutively resistant to the parental FMDV C-S8c1. Curing of late-passage C1-BHK-Rc1 cells of FMDV by ribavirin treatment (J.C. de la Torre, B. Alarcón, E. Martínez-Salas, L. Carrasco, and E. Domingo, J. Virol. 61:233-235, 1987) did not restore sensitivity to FMDV C-S8c1. The resistance of C1-BHK-Rc1 cells to FMDV C-S8c1 was not due to an impairment of attachment, penetration, or uncoating of the particles but to some intracellular block that resulted in a 100-fold decrease in the amount of FMDV RNA in the infected cells. FMDV R59, the virus isolated from late-passage carrier cells, partly overcame the cellular block and was more cytolytic than FMDV C-S8c1 for BHK-21 cells. Sequencing of the VP1 gene from nine viral clones from C1-BHK-Rc1 cells showed genetic heterogeneity of 5 X 10(-4) substitutions per nucleotide. Mutations were sequentially fixed during persistence. In addition to resistance to FMDV C-S8c1, C1-BHK-Rc1 cells showed a characteristic round cell morphology, and compared with BHK-21 cells, they grew faster in liquid culture, were less subject to contact inhibition of growth, and had an increased ability to form colonies in semisolid agar. Reconstitution of a persistent infection was readily attained with late-passage C1-BHK-Rc1 cells and FMDV C-S8c1 or FMDV R59. The results suggest that coevolution of BHK-21 cells and FMDV contributes to the maintenance of persistence in cell culture.

Animals↗
PubMed1988

Fibrinolytic activity in plasma after gynecological and urological surgery.

Fibrinolytic activity was studied in 51 patients subjected to major surgery (27 urological and 24 gynecological) without prophylaxis. Postoperative deep-vein thrombosis (DVT) was diagnosed by venography in 6 patients (11%). Blood samples were obtained preoperatively and on days 1, 3 and 7 postoperatively. Reduced fibrinolytic activity, as determined by prolongation of euglobulin lysis time (ELT), decrease in plasminogen activators on fibrin plate and decrease in tissue-type plasminogen activator (t-PA) activity were present postoperatively. Moreover, a marked increase in short duration in fast-acting inhibitor (PA-inhibitor) levels was observed on postoperative day 1 (p less than 0.001). Patients with DVT had higher fibrinogen degradation product (FDP) levels on postoperative days 3 and 7 (p less than 0.02). Preoperative PA-inhibitor activity was higher (p less than 0.02) in those patients who developed postoperative DVT. It is concluded that the decrease in t-PA and the increase in PA-inhibitor may contribute to the reduced postoperative fibrinolytic activity after major surgery. PA-inhibitor may represent a useful predictive marker of postoperative DVT.

Adult↗
PubMed1988

Does desmopressin acetate reduce blood loss after surgery in patients on cardiopulmonary bypass?

It has been suggested that desmopressin acetate (DDAVP) administration reduces blood loss after cardiac surgery. We have investigated the effect of DDAVP administration in a double-blind, randomized, prospective trial including 100 patients placed on cardiopulmonary bypass during surgery. Fifty patients received 0.3 micrograms/kg DDAVP and 50 patients received a placebo administered in a 50 ml saline solution over 15 min when cardiopulmonary bypass had been concluded. Results showed no significant differences either in total blood loss per square meter (458 +/- 206 ml in the DDAVP group vs 536 +/- 304 ml in the placebo group) or in necessity for red cell transfusions (1642 +/- 705 ml in the DDAVP group vs 1574 +/- 645 ml in the placebo group) in the first 72 hr after surgery. Only intraoperative blood loss per square meter was significantly lower (p less than .02) in the DDAVP group (131 +/- 106 ml) as compared with the placebo group (193 +/- 137 ml). The prolongation of bleeding time and the decrease of factor VIII:C and factor VIII:von Willebrand factor 90 min after treatment were significantly lower (p less than .001) in the DDAVP group as compared with the placebo group. We conclude that the administration of DDAVP in patients placed on cardiopulmonary bypass during surgery does not reduce total blood loss and is only effective in reducing intraoperative bleeding.

Blood Transfusion↗
PubMed1987

Reactivity with monoclonal antibodies of viruses from an episode of foot-and-mouth disease.

A panel of 12 monoclonal antibodies (MAbs) raised against foot-and-mouth disease virus (FMDV) of serotype C1 (FMDV C-S8c1) and 11 MAbs raised against other FMDVs have been used to evaluate the reactivity of 14 isolates of FMDV of serotype C1 (series FMDV C-S), 12 of them from one disease episode (Spain 1979-1982). The assays used were immunoelectrotransfer blot, immunodot and neutralization of infectivity. None of the isolates could be clearly distinguished by its reactivity with 6 non-neutralizing and 2 neutralizing MAbs raised against FMDV C-S8c1. In contrast, the isolates were distinguished in two groups by a 10(2)-fold difference in their reactivity with 6 neutralizing MAbs. The reactivity of MAbs with synthetic peptides indicated that conserved and non-conserved epitopes recognised respectively by neutralizing MAbs 4G3 and SD6 are localized in the immunogenic region (amino acids 138-156) of VP1. Thus, epidemiologically related FMDVs differ in at least one epitope critical for virus neutralization.

Amino Acid Sequence↗
PubMed1986

Prophylaxis of thromboembolic disease and platelet-related changes following total hip replacement: a comparative study of aspirin and heparin-dihydroergotamine.

A prospective study involving 120 consecutive patients undergoing total hip replacement was performed to compare the effectiveness of aspirin (high and low dose) or a combination of heparin plus dihydroergotamine (heparin-DHE) in preventing isotopic and phlebographic deep vein thrombosis (DVT), and to evaluate their effect on postoperative platelet changes. Phlebographic DVT was demonstrated in 9 cases (30%) in control group, in 1 (3.3%) in aspirin (high-dose) group (p less than 0.01), in 1 (3.3%) in aspirin (low-dose) group (p less than 0.01) and in 5 (16.6%) in heparin-DHE group (p = NS). Aspirin was able to reduce the postoperative increase in circulating platelet aggregates, platelet factor 4 and beta-thromboglobulin observed in control group. This study shows that aspirin is effective in the prevention of DVT for patients undergoing total hip replacement. Small aspirin dose (250 mg/day) represents an effective form of prophylaxis in these patients.

Aspirin↗
PubMed1986

IgD plasma cell leukemia associated with pyroglobulinemia and pyroglobulinuria.

A 70-yr-old man with multiple myeloma IgD developed a plasma cell leukemia producing a serum IgD monoclonal peak and lambda light chains in the urine. When the serum and the urine were heated at 56 degrees C for 30 min both monoclonal bands disappeared. The precipitate failed to redissolve on heating to 100 degrees C. Ion exchange chromatography with a linear gradient of phosphate buffer, pH 8, 0.020-0.300 mol/l and column electrofocusing showed that the serum pyroglobulin was eluted with buffer concentration between 0.040-0.125 mol/l and had an isoelectric point of 5.02, while the pyroglobulin of the urine was eluted with 0.020-0.033 mol/l and had a pI = 7.16. The serum and urine pyroglobulins had a total antigenic community with their correspondent purified proteins. The isolated lambda chains did not change when they were heated at 56 degrees C for 30 min, nevertheless, the heated purified IgD shows some changes in its isoelectric point, molecular mass and antigenicity. These changes in the purified IgD suggest that the pyroprecipitability could be due to conformational features.

Aged↗
PubMed1986

Prothrombin Segovia: a new congenital abnormality of prothrombin.

A family with a new congenital dysprothrombinemia is presented. The propositus is a 21-yr-old man who presented simultaneously with hemartrosis of the left knee and an extensive hematoma following a minor trauma. Prothrombin time and activated partial thromboplastin time were prolonged. Prothrombin activity was very low when measured by biological assay using physiological activators (7% by one-stage method and 20% by two-stage method) or a Russel's viper venom-cephalin mixture (23%), Notechis scutatus scutatus venom (15%) and Echis carinatus venom (17%); in contrast, the level was found to be borderline to normal using Taipan viper venom (64%) and normal by both staphylocoagulase and immunologic methods. Family studies revealed consanguinity between the propositus' mother and father and both presented a 50% reduced prothrombin level when physiological activators or Echis carinatus viper venom were used. A line of identity between normal and abnormal prothrombin was observed on immunodiffusion. The migration of the abnormal prothrombin was less anodic and was not changed by the addition of calcium. The patient's serum showed 3 bands in the bidimensional immunoelectrophoresis system, whereas normal serum showed only 2 bands. The term prothrombin Segovia is proposed to define this new prothrombin abnormality.

Adult↗
PubMed1986

Evan's syndrome, chronic active hepatitis and focal glomerulonephritis in IgA deficiency.

A 10-year-old female with a complete selective IgA deficiency and recurrent autoimmune disease (chronic active hepatitis, focal glomerulonephritis, hemolytic anemia and thrombopenic purpura) is presented. Both serum IgA and saliva secretory IgA were below the detection limit. The small bowel biopsy using a peroxidase-antiperoxidase technique showed absence of plasma cells secreting IgA. Circulating antibodies against mitochondria, microsomal thyroid antigen were detected as well as rheumatoid factor. Circulating immune complexes were present. A positive Coombs' test and a slightly positive reaction for cryoagglutinins were demonstrated. No alterations in cellular immunity were observed. Clinical and analytical improvement with prednisone and azathioprine was obtained.

Agglutinins↗
PubMed1986

Non Hodgkin's lymphomas following chemoradiotherapy for Hodgkin's disease. Two new cases and a review of the literature.

Two patients developed non-Hodgkin's lymphoma (NHL) six and ten years after radiotherapy and chemotherapy for Hodgkin's disease nodular sclerosis type. The histological classification of the developing NHL for the two patients was: IgG (K) secreting lymphoplasmacytoid lymphoma of the stomach, and immunoblastic lymphoma of the cervical lymph nodes. Both patients responded well to conventional chemotherapy for NHL and are alive 22 and 5 months after the diagnosis of the secondary tumor. Forty eight cases of NHL after treatment for HD have been previously reported. We present a review of the literature of these cases, adding to this literature the first reported case of gastric lymphoplasmacytoid lymphoma under such circumstances.

Adolescent↗