Biomedical subjects
Publications and source records attributed to A Merino.
We describe a mass located at the supraclavicular space in a patient with a 5 year history of erosive rheumatoid arthritis. The mass was initially diagnosed as a suspected metastasis, but direct puncture and magnetic resonance imaging revealed a cyst. Clinical and radiological characteristics are described and pathogenesis and treatment are discussed.
BACKGROUND: Bone marrow transplantation (BMT) from a histocompatible donor is the only curative treatment in chronic myeloid leukemia (CML). Only a minority of patients dispose of an adequate donor from among his/her relatives. The remaining transplant receptors must look to unrelated donors (URD). The experience of the Escuela de Hematología Farreras Valentí (Farreras Valentí School of Hematology, Barcelona, Spain) in BMT from URD in CML in the first chronic phase is herein reported. METHODS: Fifteen patients (9 males and 6 females, median age 33 years; range 14-48 years) were transplanted from October 1988 to May 1994. Serologic identity was expressed in the A, B and D loci in 9 cases and minor incompatibility in 6. Conditioning included total body irradiation and cyclophosphamide in 14 patients and busulphan plus cyclophosphamide in 1. Partial and selective T lymphocyte depletion was performed by elutriation in 7 cases. RESULTS: Primary implant failure was detected in 2 out of 14 risk patients (14%) and secondary failure was observed in 3 out of 12 cases (25%). The actuarial probability of acute graft versus host disease (GVHD) was 55 +/- 15% at 7 weeks with a probability of appearance with an intensity of II-IV of 31 +/- 13%. Five out of 7 patients with a survival of greater than 100 days, developed chronic GVHD (71%). Ten presented fatal complications. In 5 cases, death was due to pulmonary problems. Recurrence of CML was not observed in any of the patients in the series. The probability of disease free survival at 2 years was 30 +/- 12%. CONCLUSIONS: Bone marrow transplantation from an unrelated donor is an effective treatment for a proportion of patients with chronic myeloid leukemia although severe complications are frequent and originate a high mortality.
A case of monosomy 22 diagnosed prenatally is reported. During pregnancy, ultrasonic observations already revealed several cardiac malformations of the fetus in the 25th week. Following counselling, the pregnancy was terminated. Fetal autopsy revealed several abnormalities associated with DiGeorge syndrome.
BACKGROUND: To evaluate the efficacy of i.v. amphotericin B (AmB) as prophylaxis of deep mycosis (DM) in allogenic bone marrow transplantation (BMT). METHODS: From July 1991 to May 1993, 45 consecutive patients treated by allogenic BMT with no previous history of systemic mycosis and with normal renal function were administered prophylactic AmB at a dose of 0.5 mg/kg/48 h from day + 1 BMT until hemoperipheral recovery (group A). These were compared with an historic control group made up of 45 consecutive patients submitted to BMT from January 1990 to June 1991 who did not receive prophylactic AmB (group B). During the neutropenic phase all the patients remained in isolation units with laminar flow of filtered air and were administered oral non absorbable antibiotic therapy and diet of low bacterial content. The incidence of DM and the dose of AmB administered during the first 120 days post BMT were evaluated. RESULTS: In the first 30 days following BMT 3 (7%) cases of DM were observed in group A and 3 (7%) in group B. Four (9%) additional cases were found from days 30 to 120 in group A and 3 (7%) in group B. In 3 (7%) patients of the group which received prophylaxis and in 4 (9%) of the control group Candida spp. was isolated. In 3 (7%) patients from group A and 1 (2%) patient from group B the infection was due to Aspergillus. Although the patients from group A received therapeutic AmB less frequently (78% vs 91%) and later (13 [SD +/- 5.9] vs 9.2 [SD +/- 4.6] days) than those of group B (p < 0.002) the mean dose of AmB per patient treated was similar in both groups (11.3 [SD +/- 8.8] vs 11.8 [SD +/- 7] mg/kg). CONCLUSIONS: The prophylactic use of systemic amphotericin during the neutropenic phase of bone marrow transplantation does not reduce either the incidence of deep mycosis or the mean dose of amphotericin administered.
We explored B-cell function after tetanus toxoid (TT) immunization in 12 children with severe combined immunodeficiency disease or leukemia who were long-term survivors of an HLA-matched sibling or haplocompatible T cell-depleted parental bone marrow transplant (BMT), 10 of their healthy donors, and 13 normal controls. Specific in vivo and in vitro anti-TT antibody (Ab) production were measured by ELISA. We studied donors' and recipients' peripheral blood mononuclear cells (PBMC) and mixed E- (non-T cells) and E+ cells (T cells) spontaneously and after stimulation by TT in the absence or presence of interleukin-2 (IL-2), IL-4, and IL-6. Five of the 12 patients and all donors and controls responded with in vivo anti-TT Ab. In vitro anti-TT Ab production correlated with the in vivo response. All seven of the nonresponders were either fully engrafted or mixed chimeras (donor T cells but autologous B cells and monocytes). We could not identify a T-cell defect in four of the five nonresponders who were tested. In contrast, E- cells from three of three responders cooperated with fresh donor E+ cells even when they shared only one HLA haplotype. In three of seven nonresponders, in vitro anti-TT Ab production was restored after the addition of IL-4 or IL-6 but not IL-2. Our results suggest that the humoral immunodeficiency that exists post mismatched T cell-depleted BMT is either a B-cell, a monocyte, or a B-cell/T-cell cooperation defect which, in some patients, may be correctible with the addition of a cytokine. Also, it is not necessary to engraft donor B cells to achieve normal antibody responses and the ability to respond does not appear to correlate with pretransplant chemotherapy.
OBJECTIVES: This study attempted to determine the influence of progressive degrees of stenosis on platelet deposition onto a severely damaged vessel wall. BACKGROUND: The severity of wall injury and increased shear forces have been proposed as the determinants of thrombus formation and growth in arterial stenosis. METHODS: Carotid angioplasty was performed in 15 mongrel dogs to produce severe wall damage. Group I (n = 9) had arteries with damage only. In group II (n = 14), progressive degrees of stenosis were produced at the center of the dilated area. Acute thrombus formation was evaluated by angiography at the time of angioplasty and platelet deposition/cm2 quantified by indium-111 labeling 1 h after the procedure. RESULTS: Severe wall damage (group I) produced a significant increase in platelet deposition compared with control arterial segments (8.19 +/- 3.82 vs. 3.62 +/- 2.52 platelets x 10(6)/cm2 [mean +/- SD], p < 0.05), and the presence of a stenosis (group II) further increased platelet deposition (36.98 +/- 3.82 platelets x 10(6)/cm2, p < 0.05). Angiographic filling defects or total occlusion was found in seven of the arteries in group II but in none in group I (p < 0.05). A shear rate of approximately 5,000 s-1, corresponding to a critical stenosis of 70% and a 1.5- to 1.6-mm diameter, was found to identify the arteries in which thrombosis was likely to occur (p < 0.05). Four of 5 arteries < 1.5 to 1.6 mm in diameter had angiographic filling defects or occlusion compared with 1 of 13 with less severe stenosis (p < 0.01). CONCLUSIONS: In low shear rate conditions, deep arterial injury will lead to mural thrombosis without further thrombus growth. When deep arterial injury occurs under critical local shear conditions, platelet deposition will be enhanced, and thrombosis may progress to total occlusion.
Reconstituted transcription reactions containing the seven general transcription factors, in addition to RNA polymerase II, respond poorly to transcriptional activators. Two factors, Dr2 and ACF, necessary for high levels of transcription in response to an activator have been identified. ACF can enhance basal and activated transcription. Dr2 represses basal transcription, but this can be overcome by transcriptional activators or TFIIA. Dr2 is human DNA topoisomerase I. The DNA relaxation activity of topoisomerase I is dispensable for transcriptional repression. The effect of Dr2 is specific for TATA-box-containing promoters and is mediated by the TATA-binding protein.
We describe our 9-year experience with lectin-treated T-cell-depleted haplocompatible parental bone marrow transplantation (BMT) for 24 patients with severe combined immunodeficiency disease (SCID). Nineteen of 21 evaluable patients had T-cell engraftment; 2 of 11 patients tested had B-cell and monocyte engraftment. Fourteen of 24 (58%) patients are alive 7 months to 9.8 years post-BMT. Seventeen of 24 patients received pretransplant conditioning with chemotherapy and/or total body irradiation, and 8 of 24 received more than one transplant. Patients who received conditioning had a survival rate of 61% versus 57% for those who received no conditioning. None received graft-versus-host disease (GVHD) prophylaxis and no patient had acute or chronic GVHD greater than grade I. Kinetics and follow-up of immune recovery were analyzed in 14 patients who are greater than 1 year from transplant. Half of the patients showed evidence of T-cell function by 3 months and normal T-cell function by 4 to 7 months post-BMT. On average, T-cell numbers and subsets became normal 10 to 12 months posttransplant. Recovery of B-cell function was more delayed, although in most patients B-cell numbers and IgM levels were normal by 12 months post-BMT. B-cell function, as determined by isohemagglutinin titers or specific antibodies to pneumococcal polysaccharide, keyhole limpet hemocyanin, or tetanus toxoid, became normal in 10 of 14 patients 2 to 8 years post-BMT. Seven of the 14 are off gammaglobulin therapy. Production of isohemagglutinins tended to predict recovery of antibody response to pneumococcal polysaccharide (P < .064). Based on these results, we believe that haplocompatible BMT is an effective, curative treatment for patients with SCID who lack an HLA-matched related donor.
Octamer factor 2 (Oct-2, OTF-2, NF-A2) is an 'upstream' promoter factor that binds to the octamer motif (ATGCAAAT) implicated in control of immunoglobulin gene transcription in B-lymphocytes. We have studied the role of Oct-2 in the process of transcription initiation in vitro using both nuclear extracts and purified basal transcription factors. Oct-2 specifically stimulates transcription from octamer-containing promoters in both systems. Thus, Oct-2 is a 'true activator', rather than merely an 'anti-repressor' counteracting the effect of histones. In order-of-addition experiments, Oct-2 is required early, together with TFIID, to allow formation of a preinitiation complex. Oct-2 cannot functionally interact with cloned TATA binding protein (TBP) but rather requires 'coactivators' found in the TFIID fraction. In single-round transcription experiments, early competition for Oct-2 by an octamer oligonucleotide is deleterious, but no effect is seen after assembly of a complete preinitiation complex. However, for multiple rounds of transcription, Oct-2 is continuously required at the promoter; this result argues against a 'hit-and-run' mechanism whereby the activator becomes dispensible after organizing a TFIID-promoter complex. In agreement with our previous studies in vivo, the N-terminal glutamine-rich activation domain of Oct-2 is required for full activity in vitro, indicating that this domain directly interacts with basal transcription factors.
We present two prenatal cases of trisomy 9 mosaicism, both of which presented intrauterine growth retardation (IUGR) and other abnormal ultrasound findings. In case A, mosaicism was found in amniotic fluid cell cultures, of which 65 per cent were trisomic cells, on average. In case B, trisomic cells were present in amniotic fluid cell cultures (12 per cent) but none were found in fetal cord blood. After autopsy, cytogenetic findings were confirmed in different tissue cultures. It is concluded that echographic indicators are a very useful tool for a correct prenatal diagnostic interpretation of trisomy 9. Suspected trisomy 9 mosaicism always requires further investigation and fetal cord blood cytogenetic analysis may not be considered as providing an accurate diagnosis of fetal trisomy 9.
Transcription initiation plays a central role in the regulation of gene expression. Exciting developments in the last year have furthered our understanding of the interactions between general transcription factors and how these factors respond to modulators of transcription.
PURPOSE: Bone marrow transplantation (BMT) is an effective treatment for acute and chronic leukaemias. Lymphocyte depletion of donor bone marrow for preventing GVHD has been associated with a higher incidence of relapse after allogeneic BMT. This association suggests an antileukaemic effect of donor lymphocytes. In vitro studies show that cytotoxic T lymphocytes (CD3+ CD56+) and NK cells (CD3-CD56+) have an antileukaemic effect. To know which specific subpopulation of lymphocytes are depleted by counterflow centrifugation or elutriation, we analysed B, T, NK cells and hematopoietic precursors in the marrow fractions after this procedure. PATIENTS AND METHODS: Eight patients (6 CML, 1 ALL, 1 B-CLL) received an allogeneic BMT with lymphocyte depletion of the bone marrow graft using elutriation. After a Percoll gradient, donor marrow mononuclear cells (MNC) were separated with this method in five fractions (F1 to F5). RESULTS: Lymphocyte depletion of donor marrow was in average of 1.7 log. This depletion was also selective, the last fraction containing higher number of cytotoxic T lymphocytes and NK cells than the other fractions. Recovery of CD34+ cells in the four fractions concerning to post-Percoll marrow was 84%, most of them being in the last fraction. CONCLUSIONS: The use of elutriation for lymphocyte depletion is a good method for graft manipulation with the feasibility to adjust a lymphocyte/Kg. dose. Elutriation may be effective in reducing the incidence and severity of graft versus host disease and preserving the antileukaemic effect.
The efficiency of the GIBCORkit "Human Bone Marrow Stem Cell Proliferation Kit" for haemopoietic progenitors cultures, has been assessed in 24 bone marrow samples. The results, compared with those obtained in a parallel study with the routine method used in our laboratory (reference method), suggests that the kit has higher capacity for detecting haemopoietic progenitors, which is due to the increased number of BFU-E (108 +/- 78 vs 23 +/- 23, p < 0.0001). Total CFU-GM (considered here as the sum of CFU-G and CFU-M), do not differ significantly from the reference method (70 +/- 64 vs 77 +/- 64, p = 0.60) despite its increased CFU-G growth (25 +/- 26 vs 67 +/- 54, p < 0.0001). The finding of similar results in a multicentric study may contribute to demonstrate the advantages of this standardized method in the clinical practice.
We evaluated proliferative responses in mixed lymphocyte cultures (MLC) following bone marrow transplantation (BMT) in 14 recipients of T cell-depleted haplo-compatible parental marrow: 11 for the treatment of severe combined immunodeficiency (SCID), 2 for leukemia and 1 for Wiskott-Aldrich syndrome (WAS). We compared the results obtained in 9 SCID patients and 1 WAS patient with split chimerism (T cells of donor origin, B cells and monocytes of recipient origin) to 4 patients (2 SCID and 2 leukemias) who were full chimeras (T, B and monocytes of donor origin). In the full chimeras, as with the fresh donor PBMC, fresh donor T cells did not proliferate in the MLC to recipient non-T cells (E-). In this group there were no differences (p > 0.2) between the responses of engrafted T and fresh donor T to recipient E- cells. We found tolerance of engrafted donor T cells to residual mismatched T cell-depleted (E-) recipient cells in the split chimera group. In this group the engrafted T cells had low or no responses in MLC to HLA mismatched E- host cells compared with fresh donor cells (p < 0.001). In 3 of 8 split chimera patients that we tested the addition of small numbers (5000-10,000) of freshly isolated donor T cells, irradiated or not, resulted in a two fold increase in the engrafted T cell response to recipient E- cells. In contrast, in 3 of 3 full chimeras tested, the addition of fresh donor T cells had no demonstrable effect on the response of engrafted T cells to recipient E-.(ABSTRACT TRUNCATED AT 250 WORDS)
A patient with chronic alcoholism displayed significant ascites and a splenic pseudocyst, after relapsing chronic pancreatitis. The pathogenic possibilities are commented. The break of pancreatic ducts, with extravasation of enzymes, that would reach adjacent structures, is a common mechanism to both complications. The authors suggest aspirative puncture for the definitive diagnosis, following splenectomy and distal pancreatectomy as the safest treatment.
Field flow fractionation (FFF) is a new methodology described as being well-suited for the separation and characterization of biopolymers and particles. On theoretical grounds, cells may be separated with FFF if they differ in size, density or deformability. In the present study, we first tried to determine optimal separation conditions for red blood cells; thereafter we used FFF to examine red cell changes during a phenylhydrazine-induced hemolytic anemia. It has been shown that in less than 30 minutes, FFF is able to separate normal red blood cells from Heinz body-rich cells or reticulocytes that differ in size or density. The successive steps of hemolysis and regeneration appear clearly on the fractograms. Advantages and drawbacks of the method are discussed.
A new 11.5F over-the-wire vascular hemostasis device was compared to conventional manual compression in normal swine femoral arteries. Using percutaneous techniques, the collagen was deposited and hemostasis achieved in 7 vessels after 1 minute total, plus 4 minutes partial compression, while control manual compression required more than 5 minutes total compression to avoid hematoma formation. One month follow-up of treated arteries (n = 4) and controls (n = 3) showed no impairment in distal pulse or differences in histology at the puncture site in the control and treated arteries. Thus, the vascular hemostasis device technique is safe and effective, achieves hemostasis with less compression time and complications, and does not interfere with arterial wall healing or compromise the lumen.
OBJECTIVES: This study was designed to determine the blood elements responsible for spontaneous echocardiographic contrast. BACKGROUND: Spontaneous contrast or "smoke" is an echocardiographic image usually found in low flow conditions. Two blood elements, erythrocytes and platelets, have been related to the generation of smoke. METHODS: The echogenicity of porcine blood products was assessed in static and flow conditions and was graded on a digitized videodensity computer program that assigned a score of 0 for black and 100 for white images. Blood elements were circulated from a small tube (4-mm diameter) into a larger cylindric chamber (30-mm diameter) under controlled flow rate conditions. The following blood products were studied: whole blood, platelet-depleted blood, platelet-rich plasma, platelet-poor plasma, erythrocytes suspended in saline solution, adenosine diphosphate (ADP) added to platelet-rich plasma, and saline solution as a control medium. RESULTS: As blood flow was increased in 30 ml/min increments from 0 to 180 ml/min, whole blood echo videodensity (scale 0 to 100) progressively decreased in the larger tube from 38 and 42 to 20, 12, 14, 16 and 14, respectively. When flow increased from 0 to 30 ml/min in the smaller tube, corresponding to a wall shear rate of 0 to 80 s-1, the blood entering the chamber was completely echolucent. The echogenicity of blood products in the larger tube was for static flow (0 ml/min) and high flow (180 ml/min), respectively: platelet-depleted blood = 36 and 14; platelet-rich plasma = 2 and 2; platelet-poor plasma = 0 and 0; erythrocytes in saline solution = 8 and 12; ADP added to platelet-rich plasma = 0 and 15; saline solution = 0 and 0. Because platelets alone were nonechogenic but platelet-depleted blood produced a flow-dependent echogenicity similar to that produced by whole blood, platelets may not be involved in the production of smoke. However, when platelets were aggregated by ADP, they were echogenic but in dense clumps and in a flow-independent pattern not typical of the smokelike images. Erythrocytes suspended in saline solution had an intermediate density image. CONCLUSIONS: Echogenic smoke appears to be due primarily to the interaction of red blood cells and plasma proteins at low flow and low shear rate conditions.