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Biomedical subjects

M Briz

Publications and source records attributed to M Briz.

At least 19 recordsLinked to original sources
PubMed1999

Modulation of apoptosis by cytokines in B-cell chronic lymphocytic leukemia.

B-cell chronic lymphocytic leukemia (B-CLL) is characterized by the slow and progressive accumulation of monoclonal apparently mature, CD5(+) B lymphocytes. The majority of circulating cells appear to be nondividing, and it has been suggested that a prolonged life span is mainly responsible for the accumulation of the leukemic cells. However, spontaneous programmed cell death by apoptosis occurs when B chronic lymphocytic leukemia cells are cultured in vitro. This may be because of the lack of an unidentified essential cytokine present in vivo. Thus, we investigate interleukin-2 (IL-2), IL-4, IL-6 and IL-10 in vitro effects on apoptosis of B cells from 32 previously untreated patients with B-CLL in initial clinical stages. B cells were isolated from peripheral blood, and apoptosis was measured in these cells immediately after isolation and following incubation in vitro, without and with the different cytokines, for 24 and 48 h. Distribution of cellular DNA content and quantitative analysis of apoptosis were determined by standard propidium iodide staining and flow cytometry. Spontaneous apoptosis occurred in B-CLL cells incubated in vitro in the absence of cytokines. Our results indicate that both IL-2 and IL-4, but not IL-6, inhibit in vitro apoptosis in a large percentage of B-CLL patients. IL-10 increases in vitro apoptotic cell number in stage 0 patients, but not in stage I and II. These data support the hypothesis that IL-2 or IL-4, may be cell survival factors in vivo and that IL-10 might be a candidate for immune therapy of early B-CLL.

Adult↗
PubMed1999

Morphologic study of the testes from spontaneous unilateral and bilateral abdominal cryptorchid boars.

Macroscopical and histological characteristics were examined in both testes from three healthy boars, three boars with unilateral abdominal cryptorchidism on the right side, and three boars with bilateral abdominal cryptorchidism. Abdominal cryptorchidism, unilateral and bilateral, provoked a significant decrease of the weight and volume of the ectopic testes. The scrotal testis of the unilateral cryptorchid boars showed an increase in its volume and weight. Cryptorchidism also induced abnormalities in the histological structure of seminiferous tubules, lamina propria, and interstitial tissue of the abdominal testes. The number of seminiferous tubules decreased; the seminiferous epithelium was constituted by few spermatogonia with an atypical pattern and by abnormal Sertoli cells. The lamina propria showed a variable degree of thickening and collagenization. The interstitial tissue was very developed but displayed a decrease in the Leydig cell population. These abnormalities were more critical in bilateral cryptorchidism than in unilateral cryptorchidism. The scrotal testis of the unilateral cryptorchid boars showed normal appearance, but a decrease of the number of seminiferous tubules was observed. Moreover, the seminiferous tubules showed impaired spermatid maturation. The alterations observed in the abdominal testes of the unilateral and bilateral cryptorchid boars were attributed to defective proliferation and differentiation of Sertoli cells and Leydig cells. The anomalies in the scrotal testis of the unilateral cryptorchid boars were due to disturbances in the Sertoli cell activity.

Abdomen↗
PubMed1999

Umbilical cord blood banking for unrelated transplantation: evaluation of cell separation and storage methods.

Cost-efficient umbilical cord blood (UCB) banking requires well-standardized methods of volume reduction and storage. To compare UCB fractionation using a technique of hydroxyethyl starch (HES) sedimentation with the Ficoll (double) and Percoll methods, 50 whole units was allocated randomly to each procedure. HES resulted in a significantly better recovery of mononuclear cells (87.5%), granulocyte/macrophage colony-forming units (CFU-GM) (88.4%), and CD34- cells (87.4%) and lesser volume reduction (85.5%). HES was the least laborious, time consuming, and expensive of the three procedures, costing 3.4- and 4.4-fold less than the Ficoll and Percoll methods, respectively. Five units processed by each method was frozen in 4.5-mL cryotubes under optimal conditions. After thawing, the greatest degree of recovery of viable nucleated cells and number of CFU-GM per unit were obtained using the HES procedure. Using 4.5-mL cryotubes, the calculated number of units that could be stored in 600-L containers was 3.8- and 2.2-fold higher for Ficoll- and Percoll-separated than for HES-separated units, respectively. Nevertheless, the higher direct costs of the density gradient separation procedures outweighed their lower storage cost. For long-term cryopreservation, we assessed the freezing of HES-processed units in 50-mL cryobags and their specifically designed canisters. We found cell recoveries similar to those obtained with cryotubes, but storage capacity was decreased. Special racks designed for these canisters resulted in a 5-fold increase over the number of units stored in standard cryobags. This system also is feasible for Percoll- and Ficoll-separated units, resulting in comparable storage costs for the three separation methods. We conclude that this HES procedure and the 50-mL cryobags constitute a cost-efficient system for large-scale UCB banking.

Blood Preservation↗
PubMed1999

Apparent cure of Graves-Basedow disease after sibling allogeneic bone marrow transplantation.

Evidence that allogeneic bone marrow transplantation (BMT) can cure or alter the course of intractable autoimmune diseases comes from both extensive experimental work in animal models and anecdotal case reports in humans. We describe a female patient diagnosed as having severe aplastic anaemia (SAA), hyperthyroidism and ophthalmopathy of Graves-Basedow disease who received a BMT from her histocompatible sister. Fifty-three months after BMT, complete remission of hyperthyroidism and ocular signs persists. The SAA is cured and she is free of any chronic graft-versus-host disease (GVHD). In the early post-BMT period, PCR analysis of bone marrow and peripheral blood cells confirmed a complete chimerism of donor origin. Thus, it is plausible to attribute the resolution of the patient's thyroid hyperfunction and opththalmopathy to the replacement of the host immune system.

Adult↗
PubMed1999

[Detection of PNH clones using flow cytometry in aplastic anemia and paroxysmal nocturnal hemoglobinuria].

PURPOSE: To detect and quantify by flow cytometry (FC) PNH clones in paroxysmal nocturnal haemoglobinuria (PNH) and aplastic anaemia (AA) patients. PATIENTS AND METHODS: We have performed a flow cytometric analysis to determine the granulocyte expression of CD55 and CD59 from 29 patients with AA and 11 patients with PNH. RESULTS: In the 11 PNH patients the study showed 58 +/- 34% and 56 +/- 32% (mean +/- SD) CD55(-) y CD59(-) granulocytes. A good correlation was found between the results of FC and haemolysis. The follow-up study showed PNH clone progression in one case and stability in 5 cases. Among 11 AA patients studied at diagnosis, two presented a population of CD55(-) granulocytes (14% and 48%) with CD59 normal, this defect disappeared in both patients after immunosuppressive therapy. The FC study revealed PNH clones in 7 cases among the 26 analyzed after treatment (23 with ATG and/or CyA), in 3 cases with negative Ham's test (in two this became positive 6 and 12 months later). The mean values obtained in these 7 patients with PNH-AA syndrome were 26 +/- 15% y 36 +/- 30% (mean +/- SD) CD55(-) and CD59(-) granulocytes. The median time from diagnosis to detection of PNH phenomenon was 83 months. In the follow-up study, 4 cases had stability, one case had a decrease and one a progression of the abnormal clone. In a retrospective analysis, among the 7 patients with PNH-AA syndrome, 5 had a partial response after the initial treatment. CONCLUSIONS: The FC on granulocytes is a useful method to diagnose and characterize PNH. This test is good for early detection of PNH clones in AA patients at initial diagnosis and in long term survivors. In both diseases it permits measuring the extent of the abnormal clone and its follow up. The extent of the defect is more related to haemolysis than the haematopoietic deficiency. PNH development seems to be more frequent in AA patients with incomplete response after immunosuppressive therapy and in some cases the defect could be latent at the time of diagnosis.

Adult↗
PubMed1998

[Detection of human herpesvirus 8 in patients with Kaposi's sarcoma or Castleman's disease associated with AIDS].

A new herpesvirus provisionally termed as KSHV or HHV-8 has been detected in lesions from AIDS-based Kaposi's sarcoma (KS) and from other KS clinical forms, and also in other tumors such as body cavity-based lymphomas or Castleman's disease (CD). We have assessed the presence of this novel herpesvirus in specimens from patients diagnosed with either AIDS and KS or AIDS and CD. DNA samples from skin lesions and peripheral blood obtained from 8 patients diagnosed with AIDS, seven with KS and one with multicentric CD were analyzed; skin specimens and peripheral blood samples from volunteer blood donors or from KS and CD free HIV seronegative patients were used as controls. Detection of the virus was done by PCR amplification of KS330 region, one of the HHV-8 sequences first reported. All skin lesions analysed tested positive for KS330; peripheral blood samples from 5 of the patients, including the one diagnosed with CD, showed also the virus sequence. All skin specimens and peripheral blood samples from controls were negative. From our results it can be concluded that the novel herpesvirus HHV-8 can also be detected in patients with AIDS-associated KS and AIDS-associated CD in Spain.

Acquired Immunodeficiency Syndrome↗
PubMed1998

Detection of maternal DNA in umbilical cord blood by polymerase chain reaction amplification of minisatellite sequences.

One of the concerns about the use of cord blood as a source of hematopoietic stem cells for allogeneic transplantation is the possibility of contamination by maternal cells which could cause life-threatening GVHD. We have assessed cord blood contamination using PCR analysis of several minisatellite regions to detect maternal DNA. Eighty mother-cord pairs were obtained for this study. In one case there were no specific maternal alleles at any loci and, therefore, cord blood could not be evaluated. Thus, there was a total of 79 informative cases for the detection of maternal cells in the fetal circulation. In most cases, the level of detection was between 0.5 and 1%. We detected maternal DNA in the cord blood sample in only one case (1.26%), and the analysis of dilution experiments led to an estimate of 0.5-1% maternal cells. In conclusion, using PCR amplification of hypervariable regions, maternal DNA is very rarely detected in the cord blood collected at birth, although this approach has a relatively low level of sensitivity.

Chimera↗
PubMed1998

Preliminary experience in external quality control of RT-PCR PML-RAR alpha detection in promyelocytic leukemia.

To standardize the results obtained in PML/RAR alpha RT-PCR detection by laboratories of hospitals involved in the Spanish Program for Treatment of Hematological Malignancies (PETHEMA) LPA-96, designed for the treatment of acute promyelocytic leukemia (APL), cDNA samples obtained by reverse transcription of RNA from bone marrow samples of patients with APL were sent to participating laboratories. During the first year of this external quality assessment trial nine samples were tested by a maximum of 12 laboratories. The control gene was satisfactorily amplified in 90% of the samples (62 of 69 samples), supporting the adequacy of the cDNA to be used as control sample. There was an 83% concordance between laboratories for PML/RAR alpha detection with similar results for the type of PML/RR alpha rearrangements. However, 17% disagreement still remained, attributable to low sensitivity or inadequacy of methods followed. The results stressed the need for implementation of an external quality assessment scheme to ensure the standardization of the results.

Gene Amplification↗
PubMed1998

Detection of herpesvirus-like sequences in Kaposi's sarcoma from heart transplant recipients.

BACKGROUND: Herpesvirus-like DNA sequences have been found in lesions from patients with Kaposi's sarcoma in its several forms, suggesting that this tumor may be caused by a new herpesvirus, referred to as Kaposi's sarcoma-associated herpesvirus or human herpesvirus 8. METHODS: We analyzed DNA from skin and lung lesions, healthy skin, and peripheral blood mononuclear cells of three heart transplant recipients with Kaposi's sarcoma. We also studied DNA from normal skin and from peripheral blood of Kaposi's sarcoma-free heart transplant recipients. Samples were analyzed by polymerase chain reaction with specific primers to amplify the KS 330 sequence. RESULTS: The KS 330 fragment was found in Kaposi's sarcoma tissue of all three patients, in normal skin of one of them, and in peripheral blood of two. It was not detected in any of the samples from skin or peripheral blood of heart transplant recipients not affected by Kaposi's sarcoma. DNA extracted from a peripheral blood sample of one patient before transplantation showed that the KS 330 sequence was already detectable at that time. CONCLUSIONS: These findings suggest that Kaposi's sarcoma-associated herpesvirus may play a significant role in the pathogenesis of all forms of Kaposi's sarcoma. The development of the tumor in transplant recipients may be related, at least in some cases, to transplantation-associated immunosuppression, rather than to the acquisition of the virus from the donor.

Female↗
PubMed1998

Mucormycosis and hemopoietic transplants.

Mucormycosis is becoming recognized as a serious complication in patients undergoing hemopoietic transplantation (HT), because it is a major cause of morbidity and mortality. In our institution 4 cases of mucormycosis in post-HT period among 345 patients undergoing HT were diagnosed between 1984 and 1997. We studies the clinical characteristics of these cases and we conclude that mucormycosis is not a common infection in patients undergoing HT but that it is followed by a high morbidity and mortality. Maintained neutropenia is the most important risk factor.

Adult↗
PubMed1997

Induction of apoptosis by 2-chlorodeoxyadenosine in B cell chronic lymphocytic leukemia.

We investigated whether 2-chlorodexoyadenosine could induce apoptosis in B cell chronic lymphocytic leukemia (B-CLL) cells in vitro using clinically achievable drug doses, measuring apoptosis ratio by flow cytometry. B cells were isolated from previously untreated patients and apoptosis was measured in these cells immediately after isolation and following incubation in vitro, without and with 2-chlorodeoxyadenosine at different concentrations, for 24 and 48 h. Distribution of cellular DNA content and quantitative analysis of apoptosis were determined by standard propidium iodide staining and flow cytometry. Spontaneous apoptosis occurred in B-CLL cells incubated in vitro in the absence of drug, but the level of apoptosis was greater in cells treated with 2-chlorodeoxyadenosine after the second day of culture. The present in vitro study of B-CLL cells from previously untreated patients suggests this chemotherapeutic agent activates a program of cell death by apoptosis using a drug dose equivalent to the physiological concentration used in patients in vivo. These data reveal an interesting possibility in the 2-chlorodeoxyadenosine treatment of untreated patients by neoplastic B cell apoptosis induction.

Adult↗
PubMed1997

Epstein-Barr virus associated B-cell lymphoma after autologous bone marrow transplantation for T-cell acute lymphoblastic leukaemia.

Epstein-Barr virus associated lymphoproliferative disease after autologous bone marrow transplantation (ABMT) has rarely been reported. We report a case of B-cell lymphoma following ABMT for T-acute lymphoblastic leukaemia; bone marrow was purged in vitro with monoclonal antibodies to remove T cells. Immunoglobulin and T-cell receptor gene rearrangement studies were used to demonstrate clonality and to show that this patient developed a second neoplasm after ABMT. EBV proteins and genome (type A) were present in post-transplantation lymphoma, suggesting a causative role in its development.

Aged↗
PubMed1996

Donor leukocyte infusions for treatment of relapsed acute myeloid leukemia after allogeneic bone marrow transplantation.

A 24-year-old man with acute myelomonocytic leukemia (AML-M4) who relapsed 6 months after an allogeneic BMT was treated with chemotherapy followed by donor leukocyte infusions (4.19 x 10(8) mononuclear cells/kg). The patient developed grade II acute GVHD that responded to therapy with CsA and prednisone. Chimerism was assessed by PCR amplification of the MCT 118 hypervariable region. Fourteen months after donor leukocyte infusions the patient remains in complete remission, without any morphologic and cytogenetic evidence of leukemia, and with a complete donor chimerism. This case shows that donor leukocyte infusions are an effective therapy for some acute myeloid leukemia patients who relapse after allogeneic BMT.

Adult↗
PubMed1996

HLA haploidentical cord blood cell transplant in a 15-year-old, 50 kg weight patient: successful treatment for chronic myeloid leukemia after myeloid blastic transformation.

A 15-year-old, 50 kg weight patient with CML had a myeloblastic transformation which reverted to Ph negative remission with intensive chemotherapy 5 years after diagnosis. Umbilical cord blood (UCB) from an HLA-haploidentical sister had been frozen 2 years and 9 months before, as she had no HLA-identical sibling and no suitable unrelated donor had been found. UCB transplant was selected on the basis of previous general experience with this kind of transplant, lack of a better choice of donor, and likelihood of a prompt relapse of the disease without delay and the patient developed grade II aGVHD as well as severe CsA toxicity which required discontinuation of the drug, anti-IL2r being given instead. Subsequently she only had histologic evidence of cGVHD and 1.5 years after the transplant she remains in complete hematologic remission with full chimerism and without evidence of the bcr/abl fusion gene. This case illustrates further possibilities of allo-transplantation using UCB.

Adolescent↗
PubMed1996

Splenectomy for poor graft function after allogeneic bone marrow transplantation in patients with chronic myeloid leukemia.

We report four patients with chronic myeloid leukemia (CML) that showed poor graft function after a non-T-depleted bone marrow transplantation (BMT) from an HLA-compatible sibling donor and who were successfully treated with splenectomy. Conditioning was done with cyclophosphamide (CY) and total body irradiation (TBI) without additional splenic irradiation. Three patients had enlarged spleens before BMT. The nucleated cell dose infused ranged from 2.3-3.2 x 10(8)/kg. Bone marrow (BM) examination prior to splenectomy showed BM aplasia (three cases) or hypocellularity (one case). At splenectomy no patient had evidence of cytomegalovirus (CMV) infection or severe acute GVHD; and three patients had moderately enlarged spleens. All patients were transfusion dependent. Complete hematological recovery was obtained in all patients. BM cellularity was normal 1 month after splenectomy. Complete chimerism of donor origin was documented. The four patients are alive (+16 to +58 months after BMT). Thus, in patients with CML, a poor graft function may be successfully corrected by splenectomy.

Adult↗
PubMed1995

Diagnosis of transfusion-associated graft-versus-host disease by polymerase chain reaction in fludarabine-treated B-chronic lymphocytic leukaemia.

Transfusion-associated graft-versus-host disease (TA-GVHD), has rarely been reported associated with B-chronic lymphocytic leukaemia (B-CLL). We report a patient diagnosed with B-CLL, previously treated with fludarabine, who developed TA-GVHD after being transfused during surgery for splenectomy. Diagnosis was confirmed by polymerase chain reaction (PCR) detection of donor DNA in the patient, by amplification of Y-chromosome sequence and analysis of minisatellite polymorphisms. B-CLL patients treated with fludarabine appear to be at risk for TA-GVHD and should be regarded as candidates for transfusions with irradiated blood products. This case illustrates that PCR is a rapid technique for the early diagnosis of TA-GVHD.

Antineoplastic Agents↗