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Biomedical subjects

J Batlle

Publications and source records attributed to J Batlle.

At least 19 recordsLinked to original sources
PubMed2000

A transcriptional insulator at the imprinted H19/Igf2 locus.

Igf2 and H19 exhibit parent-of-origin-specific monoallelic expression. H19 is expressed from the maternal chromosome and Igf2 from the paternal. The two genes share enhancer elements and monoallelic expression of both genes is dependent on cis-acting sequences upstream of the H19 promoter. In this work we examine the mechanisms by which this region silences the maternal Igf2 allele and we demonstrate that deletion of this region can result in high levels of activation of both H19 and Igf2 from a single chromosome. Moreover, by inserting this cis element between a promoter and its enhancer at a heterologous position, we demonstrate that the sequences carry both insulator activity and the ability to be stably imprinted. We also characterize the insulator in vitro and show that it is neither enhancer nor promoter specific.

Animals↗
PubMed1999

Induction of immune tolerance with recombinant factor VIII in haemophilia A patients with inhibitors.

We report on 11 patients (nine unrelated and a brother pair) with severe haemophilia A and factor VIII (FVIII) inhibitor, in whom immune tolerance (IIT) was induced with recombinant FVIII (r-FVIII). Their age ranged from 11 months to 47 years. The number of exposure days (ED) at inhibitor detection varied from 11 to 130. Nine of the 11 patients were high responders ¿>10 Bethesda units (BU) with peak inhibitor levels ranging from 10 to 566 BU. The other two were low responders with peak levels between 0.7 and 2 BU. Before inhibitor detection, the patients had been receiving products of various purities. The IIT regimens were very heterogeneous, and the treatment schedule varied from a short period with 50 IU kg-1 every 2 days, followed by 100 IU kg-1 every 2 days and then 220 IU kg-1 daily. The outcome was considered successful when the inhibitor level fell to 0.6 BU or lower after IIT treatment. The outcome overall was successful in nine out of 11 patients (81.8%), with the nine successful cases comprising seven of the nine high responders (77.8%) and the two low responders. Definite failure of IIT was observed in one high responder after two different IIT regimens. A second high responder is still on IIT treatment. All patients in whom IIT was successful are currently receiving r-FVIII on demand or prophylactically at various dosages. Despite the variability of the patient characteristics and the IIT schedules, this study demonstrates that r-FVIII represents an effective alternative for the eradication of inhibitors through IIT.

Adolescent↗
PubMed1999

[Correction].

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Factor V↗
PubMed1997

Alloantibody from a patient with severe von Willebrand disease inhibits von Willebrand factor-FVIII interaction.

The aim of this study was to analyze the ability of an alloantibody from a patient with severe von Willebrand disease (vWD) to interfere with the vWF domain for FVIII, to inhibit factor VIII (FVIII), and to compare it with a rabbit polyclonal antibody. The vWF domain for binding to FVIII was assayed by a method previously described but using recombinant FVIII (r-FVIII, Kogenate), which contains no vWF, instead of Hemofil M (HM). Rabbit or human antibodies towards FVIII (FVIII-Ab) were analyzed using microtiter wells with immobilized r-FVIII through a monoclonal anti-FVIII antibody and an ELISA method. IgG from plasma of a patient with hemophilia A and FVIII inhibitor was used as a positive control. Normal human and rabbit IgGs were included as negative controls. Human vWD alloantibody IgG and the rabbit anti-vWF antibody IgG reacted with immobilized normal vWF, inhibiting its binding to r-FVIII in a dose-dependent manner, which suggests that it is specific. Normal human IgG fraction, as well as nonspecific rabbit IgG, did not interfere with this binding at all. The monoclonal antibody used in this assay to immobilize vWF did not alter this interaction at all. Human vWD alloantibody IgG and the rabbit antibody against vWF showed a partial inhibitory activity to plasma FVIII as well as r-FVIII. The inhibition reached a plateau with residual FVIII activity. FVIII-Ab were not detected in human alloantibody or in rabbit antibody preparations. In contrast, hemophiliac FVIII inhibitor showed FVIII-AB. This human vWD alloantibody behaves like polyclonal heterologous antibodies, and their inhibition of FVIII seems to be nonspecific due to a steric hindrance mechanism provided that both have no FVIII antibodies.

Animals↗
PubMed1997

The problem of diagnosing von Willebrand's disease.

Diagnosis of von Willebrand's disease (vWD), particularly vWD Type 1, remains a clinical problem for several aspects. Its definitive diagnosis requires documentation of three factors: bleeding, low levels of qualitatively normal von Willebrand factor (vWF), and inheritance. In the absence of any of these factors the diagnosis may be only merely 'possible', or even unacceptable. Laboratory diagnosis of vWD includes screening tests and confirmatory tests. vWD Types 2 and 3 are relatively easy to diagnose and appear to be genetic disease of a single locus, the vWF gene. As new genetic and possibly non-genetic factors are discovered, the diagnosis of vWD Type 1 may become easier.

Diagnosis, Differential↗
PubMed1996

Antibodies to factor VIII in plasma of patients with hemophilia A and normal subjects.

Non-neutralizing factor VIII (FVIII) antibodies (FVIII-Ab) in hemophilia A may be associated with an abnormal clinical response to FVIII concentrates. Patients with FVIII inhibitors may develop noncoagulation FVIII-Ab after the induction of immunotolerance. Natural FVIII-Ab may be detected in the plasma of some healthy subjects. The aim of this study was to analyze the presence of FVIII-Ab in the plasma of 53 normal blood donors and 124 patients with hemophilia A (18 patients had a previous history of FVIII inhibitor, but only 12 had inhibitor at the moment this study was performed). FVIIII inhibitor was measured using the Bethesda method. FVIII-Ab were analyzed by a specific ELISA assay using purified FVIII from a monoclonal concentrate and a standard plasma containing 26 Bethesda units (BU) of FVIII inhibitor. Purified FVIII was used to coat wells of a microtiter plate and was incubated with dilutions of plasma to be tested. Bound human IgG FVIII-Ab were detected by incubation with polyclonal sheep anti.human IgG alkaline phosphatase conjugate, and the OD405 was quantitated. A linear fit was obtained (by plotting FVIII-Ab positivity [OD 405nm] versus BU titer) when serial dilutions of this standard inhibitor plasma, containing titers of 0.5 BU or higher, were used. Four different levels of FVIII-Ab positivity [OD 405nm] were distinguished in this assay: Negative levels (-) were obtained with dilutions of the standard inhibitor containing < 0.5 BU. Mild levels (+) were obtained with dilutions of 0.5-5 BU. Moderate levels (+2) were obtained for dilutions ranging from 5-25 BU. Maximum positivity (+3) was obtained for dilutions of titers > 25 BU. FVIII-Ab positivity was detected in eight of the normal subjects (15%): three were found to be moderately positive (+2) and five mildly positive (+). No inhibitory activity was detectable when whole plasma was used. All the hemophilic patients with a presence of FVIII inhibitor at the time of the study were found to be positive for FVIII-Ab. In addition, the level of positivity correlated with the corresponding BU. Four of the six patients who had a history of inhibitory were negative and two positive. Twenty additional patients (16.12%) in whom no inhibitory activity was detected were found to be positive for FVIII-Ab: 16 + and four +2. The mean age of patients with FVII-Ab positivity was significantly higher than that of patients of the FVIII-Ab negative group (p < 0.005). In conclusion, FVIII-Ab positivity in patients with hemophilia A was 17.7% higher than the level of positivity detected by an inhibitory assay. We propose that this method for FVIII-Ab analysis could be used for patients with hemophilia A, at least to complement the functional inhibitor assay. FVIII recovery or half-life should be assessed in patients who test positive for FVIII-Ab and who show no evidence of inhibitor.

Adolescent↗
PubMed1994

Hemophilia A or von Willebrand disease?

Seven members of the same family were studied on several occasions due to a history of hemorrhages. The propositus, a 12-year-old boy, his sister, one brother, and their father all had a low plasma factor VIII (FVIII) level. Von Willebrand factor (vWF) activity, vWF multimeric analysis, and vWF factor domain for binding to FVIII were normal in all seven subjects. The sister had a normal 46XX karyotype. The study of two intragenic restriction fragment length polymorphisms (RFLPs) and two closely linked, highly polymorphic extragenic markers showed a phenotypic expression of mild hemophilia A, which suggests that the sister of the propositus is homozygous or compound heterozygous at the hemophilia A locus. She would have inherited two hemophilic genes: one from her carrier mother and the other from her father, a mild hemophiliac.

Binding Sites↗
PubMed1994

Proteolytic processing of von Willebrand factor subunit: heterogeneity in type-IIA von Willebrand disease.

Type IIA von Willebrand disease (vWD) is a heterogeneous disorder for which two different pathogenetic mechanisms have been proposed: increased proteolytic susceptibility of von Willebrand factor (vWF), and/or interference of its post-translational processing. Subunit analysis of vWF in type-IIA vWD has revealed an increased relative proportion of the 176- and 140-kDa subunit-derived fragments, suggesting an augmented fragmentation of vWF, even in the resting state. We analyzed the subunit pattern of vWF in plasma from five previously described patients with type-IIA vWD. All of them showed the above-mentioned pattern. In addition, the presence of a new band with an apparent molecular mass of 200 kDa, not described in normal individuals or in patients with vWD, was repeatedly observed in one of these patients. This patient also exhibited an abnormal vWF multimeric structure in platelets and in plasma, before and after desmopressin administration, when the blood was collected either in the presence or in the absence of proteinase inhibitors. We believe that an abnormal primary structure of vWF could be responsible for this abnormal proteolytic fragmentation pattern, as well as for the abnormal multimerization of vWF. Moreover, an abnormal susceptibility to proteolysis appears to be present, as suggested by the increase in the relative proportion of the 176-kDa fragment observed in the same patient. Future sequencing studies and genetic analysis may clarify whether there are one or two different defects related to the vWF of that patient. Our results indicate that the subunit analysis of vWF may reveal additional defects present in type-IIA vWD that may help our understanding of the pathogenesis of such disease.

Blood Platelets↗
PubMed1994

Prevalence, follow-up and clinical significance of the anticardiolipin antibodies in normal subjects.

To date very few studies that analyze the prevalence of anticardiolipin antibodies (ACA) in healthy subjects have been reported. No data based on a systematic analysis of normal subjects with positive ACA is available. The aim of the present study was to evaluate the prevalence of ACA; its clinical significance and relationship to the lupus anticoagulant (LA) and other autoimmune parameters in an apparently healthy population. 552 normal blood donors from a blood bank were randomly selected. ACA positive donors who consented were monitored over a period of twelve months and tested every three months. ACA (IgG and IgM isotypes) were quantitated by enzyme linked immunoassay (ELISA). The prevalence for IgG ACA in our donor population was estimated to be 6.5%, and 9.4% for IgM ACA, which is similar to the one previously reported for IgG and slightly higher for IgM. It is worth noting that in our study ACA positive donors exhibited a progressive negativization. Eight donors with IgG ACA and seven with IgM ACA remained positive for nine months. Five donors with IgG ACA and four with IgM ACA had family history of thromboembolic disease. One donor with IgG ACA and two with IgM ACA had had unexplained miscarriages in the past. We did not find any relationship between ACA and LA, nor between ACA positivity and the clinical and laboratory data studied. Pseudopositivity for lues was not found. No thrombotic event occurred in donors that were positive for ACA during the 12-month follow-up.

Adult↗
PubMed1994

[Comparative multicenter study of a rabbit high-sensitivity thromboplastin and a recombinant thromboplastin with synthetic phospholipids].

PURPOSE: The purpose of the present study was to compare the results obtained with a human recombinant thromboplastin (Innovin, Baxter) (IN) and a high-sensitivity rabbit brain reagent (Thromboplastin IS, Baxter) (IS), on the performance of prothrombin time (PT) test and the functional assay of factors included in the extrinsic coagulation system, in order to establish possible differences on imprecision, diagnostic accuracy and sensitivity to the oral anticoagulant defect, between the two products. MATERIAL AND METHODS: Six Spanish hospital took part in the study. Plasma samples from 221 healthy subjects, 100 patients with severe liver disease, 27 with dysfibrinogenaemia, 10 with lupus anticoagulant and from 13 individuals propositus and their relatives with congenital deficiencies of the extrinsic coagulation pathway, and their relatives were studied; 188 patients stabilized on oral anticoagulant therapy and 82 on heparin therapy were also included. The in vitro effect of heparin was tested by addition of increasing amounts of heparin (0.3 to 10.0 IU/mL) to aliquots of normal plasma. RESULTS: Both in the intra-assay and in the inter-assay imprecision study, a better coefficient of variation was obtained with IN when the PT was performed on abnormal samples. Prothrombin time ratio from patients with liver disease had significantly higher values with IS. On the contrary, IN had a higher sensitivity in samples from patients with dysfibrinogenaemia or from those stabilized on oral anticoagulant therapy. In showed a very low sensitivity to heparin at concentrations corresponding to the therapeutic range. CONCLUSIONS: The results of this field study indicate that IN, compared with a high-sensitivity rabbit brain thromboplastin, is a suitable reagent for PT determination in normal subjects, patients with liver disease or with congenital deficiencies of clotting factors. It shows a higher sensitivity in cases of dysfibrinogenaemia and in patients on oral anticoagulant therapy. In addition, the recombinant reagent had better reproducibility when the PT was performed on abnormal samples, and it was hardly affected by heparin within the therapeutic range.

Afibrinogenemia↗
PubMed1993

Activity-dependent plastic changes in the motor nerve terminals of the adult rat.

Small and short-lasting physiologic variations in the locomotor activity of normal adult rats can induce remodelling in the motor nerve endings of the fast extensor digitorum longus muscle. The specificity and relative importance of the different plastic adaptations occurring in the presynaptic axonal tree have been studied, in silver impregnated nerve endings, by using an automatic image analysis treatment of the nerve terminals' geometric properties and a discriminant analysis of the morphometric parameters. Changes observed, like selective length variations in certain terminal segments and positional rearrangements, agree with a mechanism of neural connectivity regulation in the adult that arises as a consequence of normal neuromuscular activity.

Adaptation, Physiological↗
PubMed1993

[Therapy of disseminated intravascular coagulation in acute promyelocytic leukemias. Apropos of 19 cases].

PURPOSE: To evaluate our experience in the treatment of disseminated intravascular coagulation (DIC) associated to AML-M3 with substitution therapy with or without heparin. PATIENTS AND METHODS: The clinical records of 19 patients diagnosed of AML-M3 in the Hospital Juan Canalejo, in La Coruña, between 1986 and 1991 were revised. DIC was defined by abnormalities in one or more of the following: prothrombin time, activated partial thromboplastic time, thrombin time, fibrinogenaemia, fibrin/fibrinogen degradation products, D-dimers. The treatment given to 13 patients was only substitutive including platelets, fresh-frozen plasma, cryoprecipitates and antithrombin III. Low-dose sodium heparin (Kabi) in continuous intravenous infusion was associated to the treatment of the remaining 6 patients. With regard to the leukaemic therapy, most of the patients received daunorubicin, 2 mg/kg/day x 5 days, and AraC, 100 mg/Kg/day x 7 days. RESULTS: All patients showed haemorrhagic symptoms at diagnosis, and laboratory data of DIC were present in 11 cases (57%). The mean duration of DIC was 6.5 days for the patients receiving substitutive treatment and 9.5 days for those given heparin. Complete remission (CR) of the leukaemia was attained in 12 cases (63%); of the patients treated with heparin, 50% achieved CR whereas 75% of those receiving substitute therapy attained CR. The 24-months survival rate was 30% for the patients treated with substitutive therapy and 16% for those treated with heparin. The incidence of death associated to haemorrhage during induction therapy was 30% for the substitutive treatment group and 50% for the heparin group. CONCLUSION: Shorter duration of DIC, lesser rate of early death, higher CR rate and longer 2-year survival were found in those AML-M3 patients not receiving heparin.

Adolescent↗
PubMed1992

Further evidence for recessive inheritance of von Willebrand disease with abnormal binding of von Willebrand factor to factor VIII.

A new family with a bleeding diathesis and FVIII deficiency secondary to abnormal binding of von Willebrand factor (vWF) to factor VIII (FVIII) is described. Two propositi of this family, an 18-year-old male and a 33-year-old female, both with a history of epistaxis, bruising, bleeding from the gums, epistaxis, hemarthrosis, and hematoma, were analyzed. Also additional members of the same family with no bleeding history were also studied. The propositi showed normal vWF activities, low FVIII activity; one of them had been diagnosed as having hemophilia A and the other was a hemophilia A carrier. Both showed a very poor response to treatment with FVIII concentrates and desmopressin (DDAVP) but a good clinical response to cryoprecipitate. APTT was prolonged and no inhibitory activity was noticeable in their plasmas. Thirty-five units per kilogram body weight of Hemofil M was infused to both propositi and FVIII reached basal level within 60 minutes of the infusion. No FVIII response at all was observed in the female after intravenous DDAVP administration. However, the male who received the infusion of 35 U/kg body weight of Humate-P achieved a normal FVIII level that was maintained for 12 hours. Multimeric analysis of vWF was normal in all the members studied. Von Willebrand factor domain for FVIII binding was assayed in the two propositi and in six other members of the same family by using a non-isotopic and sensitive method, a modification of the one previously described, using the Hemofil M concentrate as exogenous FVIII. The data obtained showed that both propositi had similar binding to that observed by using plasma of a patient with severe von Willebrand disease. Furthermore, five siblings had a decreased binding of vWF to FVIII, when compared with plasma from normal individuals or patients with hemophilia A. We also observed that, for screening purpose, the ratio of bound FVIII/immobilized vWF (at saturation of the anti-vWF and offering of 1 U/ml of exogenous FVIII) distinguished two levels of abnormality (normal range 0.70-1.15, propositi 0.004-0.007, and remaining members affected 0.25-0.42). The most probable explanation is that the propositi are homozygous or double heterozygous, the other five siblings affected being heterozygous for a recessive vWF defect. This more accessible assay presented here may be of help in routine analysis for diagnosing this type of von Willebrand disease, which has important implications for therapy and genetic counseling.

Deamino Arginine Vasopressin↗
PubMed1992

Pattern of arborization of the motor nerve terminals in the fast and slow mammalian muscles.

A silver impregnation method and a morphometric approach were used to define differences existing in the motor nerve terminal branching pattern between a fast-twitch muscle (extensor digitorum longus) and a slow-twitch one (soleus) of the normal adult rat. Because no single measure can describe precisely all geometrical properties (ie both topology and metrics) of the nerve terminals, we evaluated morphologic parameters defining length and angular characteristics in the different terminal segments classified according to their centrifugal order. The main results indicate that the distal free-end segments in the extensor digitorum longus muscle are shorter and less divergent than in the soleus nerve terminals. The endings in the two muscles have different fractal dimensions. Findings are discussed in the context of the hypothetical mechanisms governing motor nerve terminal size and complexity.

Animals↗