Search PubMed⌕ Search

Biomedical subjects

M Briz

Publications and source records attributed to M Briz.

At least 37 records · Page 2Linked to original sources
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

Resistance to osmotic stress of horse spermatozoa: the role of ionic pumps and their relationship to cryopreservation success.

To study the resistance of horse spermatozoa against hyperosmotic stress, cells were incubated in solutions of 600 to 4000 mOsm(undisturbed media). Then, semen was immediately placed into an iso-osmotic solution (disrupted media). Incubation in undisturbed media decreased sperm viability in an osmolarity- and temperature-dependent manner. Viability was further decreased in disrupted media, with the effect dependent upon the initial osmolarity of the media and on the temperature. Treatment with ouabain or amiloride impaired the resistance of horse spermatozoa to hyperosmotic stress. Very few correlations were strong between viability after hyperosomotic stress and quality parameters of fresh and frozen-thawed horse semen. The results indicate that the usefulness of resistance to hyperosmotic stress in assessing frozen-thawed semen quality is compromised, since other factors are involved in the resistance to freezing-thawing. Both Na (+)K (+) ATP-ase and the Na (+)H (+) antiporter act in the resistance to hyperosmotic stress in horse spermatozoa.

Journal Article↗
PubMed1997

Subjecting horse spermatozoa to hypoosmotic incubation: effects of ouabain.

Although hypoosmotic tests are widely used to assess spermatozoal quality in different species, they have not been used extensively in the stallion. Moreover, the role of the Na (+)K (+), ouabain sensitive-ATP-ase in the response of equine sperm to hypoosmotic shock is not well understood. This study tests two hypotheses: 1) that equine spermatozoa will respond to a hypoosmotic medium by swelling of the tail, and 2) that addition of ouabain will increase the percentage of swollen sperm tails. Ejaculates from 3 stallions were collected with an artificial vagina and diluted in Kenney's medium (Time = 0). Aliquots were randomly selected to be incubated in an isoosmotic (297 mOsm) or different hypoosmotic media that were composed of citrate or of citrate wïth fructose. The osmolarity of the hypoosmotic media with citrate ranged from 18 to 96 mOsm, and the medium composed of citrate plus fructose (HOS medium) was of 153 mOsm. Moreover, aliquots of spermatozoa pretreated with ouabain were added to the isoosmotic medium and also to the HOS and the 96 mOsm citrate medium (ORT medium). Incubation of equine sperm in the hypoosmotic media resulted in a time- and osmolarity-dependent swelling of the sperm tail, reaching maximum values after incubation for 20-30 min in both the HOS and ORT media. Ouabain induced a dose-dependent effect on swollen tails and viability in fresh semen and also affected some parameters related to motility. Ouabain also increased the swelling response in a hypoosmotic medium although viability decreased. The percentage of swollen tails after incubation in ORT and HOS media snowed significant correlations to viability, altered acrosomes and total motility, but not to other parameters of horse semen analysis. Our results suggest that hypoosmotic tests could be used to improve standard horse semen analysis. Additionally, Na (+)K (+)-ATP-ase activity could be related to the response against hypoosmotic shock of horse spermatozoa.

Journal Article↗
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↗
PubMed1995

[Efficacy of various treatments in the management of idiopathic thrombocytopenic purpura in the adult].

PURPOSE: To evaluate the ITP treatment modalities and their results in a series of 30 adult patients. PATIENTS AND METHODS: 30 patients, age 15-74, were diagnosed of ITP in our institution between 1988 and December 1991. We defined the ITP as: mild (platelets > or = 50 x 10(9)/L and < or = 120 x 10(9)/L), moderate (platelets 25-50 x 10(9)/L) and severe (platelets < or = 25 x 10(9)/L). Treatment was initiated when the platelet count reached a level < 50 x 10(9)/L. Initial therapy was oral prednisone or methyl-prednisolone in all patients. In 12 unresponsive patients the treatment included splenectomy. Patients who fail steroid therapy and splenectomy received additional lines of therapy, that included: vincristine (n = 2), vinblastine (n = 1), danazol (n = 5), anti D immunoglobulin (n = 6), methotrexate (n = 2), intravenous immunoglobulin (n = 3). RESULTS: Complete remission was obtained in 19 patients with a follow-up of 3 to 55 months (median, 30 months). Partial remission was achieved in 4 patients, that was sustained for 9 to 39 months (median, 22.5 months) after initial therapy. One unresponsive patient died of infection. Six mild ITP patients did not require therapy with a follow-up of 14 to 56 months (median, 33.1 months). CONCLUSION: In adult patients with mild ITP, therapy is not required. Steroid therapy remains the initial therapeutic choice for moderate and severe ITP. In unresponsive patients useful alternative choices are splenectomy, danazol, anti D immunoglobulin and methotrexate.

Adolescent↗
PubMed1995

[Treatment with fludarabine of chronic refractory lymphoid leukemia].

PURPOSE: New antimetabolic drugs, purine-analogous, have been introduced in the treatment of advanced or refractory cases of chronic lymphocytic leukaemia (CLL), fludarabine (FLU) being one of such drugs. The results attained with FLU in 6 cases of refractory CLL are reported. PATIENTS AND METHODS: The efficacy and toxicity of FLU was evaluated in 6 patients (median age 63 years) between March 1993 and March 1994. Five patients were in stage III-IV and one in stage II of the Rai's system, and they were refractory to the usual treatment. The dosis used here was 30 mg/sq m/day, for 5 days every 4 weeks, up to a total of 6 therapeutic courses. The response was assessed after 3 and 6 courses. Anti-infectious prophylaxis was made with co-trimoxazole, monthly benzathine penicillin G and isoniazid in Mantoux-positive patients. The response criteria were those given by the NIC Working Group for CLL. RESULTS: The patients received 2 to 6 courses. None of them attained complete remission: 1 had nodular remission, 2 had partial remission, 2 responded partially although not reaching criteria for partial remission (1 died of pancytopenia), and 1 had disease progression and died after the second course. Fast and important reduction of the lymphocyte count as well as the CD4 lymphocytes was present in all cases. Bone-marrow infiltration decreased strikingly in 2 cases and the platelet count improved in 3 cases and worsened in 2 others. The following toxicity was recorded: 2 patients had nausea, 5 had neutropenia (below 500 x 10(9)/L in 3 instances) and 4 had thrombocytopenia (lower than 40 x 10(9)/L in one case). In 26 therapeutic courses there were 10 febrile episodes (1 for pneumonia, 1 for gastroenteritis and 8 without any septic foci); 1 patient developed pulmonary tuberculosis after completing the treatment and one patient died of posttransfusion graft versus host disease after splenectomy once she had completes six courses. CONCLUSION: This experience confirms the efficacy of FLU in the treatment of refractory B-CLL patients and is in agreement with previous reports as no response is initiated after the 3rd course. The lymphocyte count decreases quickly and strikingly. Depletion of CD4 lymphocytes along with neutropenia and hypogammaglobulinaemia make these patients highly sensitive to all types of infection, chiefly by opportunistic germs, so adequate anti-infectious prophylaxis is of great importance. The two patients with pre-treatment haemoglobin and platelet values lower than 10 g/dL and 40 x 10(9)/L, respectively, were the only ones in need of transfusion. No cumulative myelosuppression was appreciated.

Aged↗
PubMed1993

Ultrastructural abnormalities of boar spermatozoa.

Described here are the main ultrastructural malformations observed in spermatozoa of ejaculates collected from healthy, adult Landrace boars following 2 days of sexual abstinence. Previously semen had been collected 3 times per week. Sperm concentration in the cell-rich fraction of ejaculates was approximately 700,000 sperm/mm(3). The aberrant gamete forms did not exceed 2% of the total number of spermatozoa. Ultrastructural anomalies of spermatozoa were classified into 2 groups: head malformations and tail malformations. These consisted of: 1) spermatozoa with expanded and vacuolated acrosomes, 2) spermatozoa with myelin figures within the perinuclear space, 3) macrocephalic spermatozoa with 2 nuclei and a deformed acrosomal vesicle, 4) spermatozoa with an expanded acrosomal apex, 5) spermatozoa with nuclear vacuoles, 6) macrocephalic spermatozoa with a roundish head, 7) spermatozoa with swollen mitochondria, 8) spermatozoa with additional mitochondria over the mitochondrial sheath, 9) spermatozoa without the central microtubular pair, 10) spermatozoa without some peripheral doublets, 11) spermatozoa with 1 or 2 coiled tails, 12) spermatozoa with a folded tail and a disorganized connecting piece, 13) spermatozoa with a vesiculated tail, and 14) spermatozoa with 2 tails fused by their respective mitochondrial sheaths.

Journal Article↗
PubMed1992

Origin, development and ultrastructure of boar spermatozoa with folded tails and with two tails.

Spermatozoa from the three epididymal regions (head, body and tail) of healthy and sexually mature boars have been examined by light microscopy, and scanning and transmission electron microscopy. The origin, development and external and internal morphologies of aberrant spermatozoa with folded tails and spermatozoa with one or two heads and two fused tails have been established. A count carried out in each region of the epididymis indicated that significant differences (P less than 0.01) exist in the frequencies of each type of malformation and the epididymal region from which the spermatozoa come. Spermatozoa with folded tails at Jensen's ring originate in the cauda of the epididymis from immature spermatozoa that have not ejected the distal cytoplasmic droplet. The plasma membrane which covers the main piece is fused with the membranes of the midpiece, the connecting piece and the head. The fibrous sheath deforms the mitochondrial sheath and is placed between the plasma membrane and the postacrosomal dense lamina. Spermatozoa with one head and two fused tails originate in the epididymal body from spermatozoa with one head and two unfused tails coming from the cephalic region of the epididymis. Spermatozoa with two heads and two fused tails originate in the cephalic region of the epididymis by head-to-head agglutination of two spermatozoa and later fusion of their tails. The frequency of spermatozoa with two fused tails increases as they progress through the epididymal duct. Their tails, parallel in monocephalic spermatozoa and helicoid in bicephalic spermatozoa, have two complete axonemal axes. In their midpiece, the mitochondrial sheaths of the two axes are fused, producing an 8-shaped sheath.

Animals↗
PubMed1991

New data on aberrant spermatozoa in the ejaculate of Sus domesticus.

This paper describes 16 new types of aberrant spermatozoa observed by scanning electron microscopy in the ejaculate of two healthy, sexually mature Landrace boars. The new anomalies observed were 1) spermatozoa with folded tail and abnormal head; 2) tailless spermatozoa with an abnormal connecting piece; 3) immature spermatozoa with two tails of the same length, fused and coiled; 4) spermatozoa with two tails of the same length, fused and coiled, and a small, rounded head; 5) spermatozoa with two fused tails and a wide head; 6) spermatozoa with three tails of the same length, fused and coiled; 7) immature spermatozoa with two heads and two fused tails; 8) spermatozoa with two heads, one at each tip of the tail; 9) spermatozoa with a short, folded tail and a triangular head; 10) spermatozoa with a short tail lacking the intermediate piece; 11) spermatozoa with a short tail, without the main piece and with a long intermediate piece; 12) spermatozoa with a short tail, without the main piece and with a rough head; 13) spermatozoa with small, rounded head; 14) spermatozoa with small, aberrant heads; 15) spermatozoa with small, bacillary heads; and 16) immature spermatozoa with tapering heads.

Journal Article↗