Biomedical subjects

M E Cabrera

Publications and source records attributed to M E Cabrera.

At least 37 records · Page 2Linked to original sources

PubMed1996

[Immunophenotype. Clinical and laboratory features of acute lymphoblastic leukemia in Chile. Study of 500 children and 131 adults].

We describe the clinical features and immunophenotype of 500 children and 131 adults with acute lymphoblastic leukemia (ALL), diagnosed between 1984 and 1993. Cases were classified, according to immunophenotype in B-cell ALL with three subtypes (pro-B or null, common and B) and T-cell ALL. Among children, common ALL accounted for 74% of cases and pro-B all was more common in children of less than one year (14%). B ALL was observed in 2% of children. Ten percent of children, mostly males, had T-cell ALL. The third part of these children had high leukocyte counts and a mediastinal mass. Children from Mapuche origin, compared with Caucasian children had a lower proportion of common ALL (36 and 74% respectively) and a higher proportions of T-cell ALL (41 and 10% respectively). Among adults common ALL was the most common phenotype (72%) followed by T-cell ALL (15%), pro-B ALL (11%) and B-cell ALL (2%). There was a lower incidence of children with common ALL with positive cytoplasmic immunoglobulin compared to North American or European studies (2 and 15-33% respectively) and a higher proportion of adults with common ALL compared with pro-B cell ALL, in contrast to European studies that show a higher proportion of patients with pro-B cell ALL. No other immunophenotypic, clinical or laboratory differences were observed with ALL from developed countries. It is concluded that the immunophenotyping of ALL allows a more precise diagnosis of this disease.

Adolescent↗

PubMed1995

HTLV-I positive progressive spastic paraparesis (TSP) associated with a lymphoid disorder in three Chilean patients.

We describe the clinical and laboratory features in three Caucasian Chilean patients with tropical spastic paraparesis (TSP) associated with/or preceded by a lymphoproliferative disorder involving cutaneous lesions and localised lymphadenopathy. The neurological symptoms and signs were characteristic of TSP and CSF examination revealed the presence of oligoclonal bands. All three patients had a moderate leucocytosis (10-14 x 10(9)/l) with eosinophilia and a minority (2-4%) of circulating atypical polylobed or ATLL-like lymphocytes. Lymph node histology showed a diffuse pattern of infiltration (1 case) and marked expansion of the paracortical zone with convoluted lymphocytes and immunoblasts (2 cases). Skin biopsy demonstrated a dermal lymphoid infiltration with epidermotropism. Antibodies to HTLV-I were detected in the serum and CSF in the three patients and Southern blot analysis of peripheral blood mononuclear cells showed a monoclonal integration of HTLV-I proviral DNA in one case whereas in the two others the pattern was indicative of low level polyclonal integration. All three patients were treated with prednisolone and one with PUVA with transient partial response on the skin and neurological manifestations. Two patients died months to 5 years from presentation and the other is alive 12 years from diagnosis with active neurological and skin disease. The simultaneous occurrence of HTLV-I associated TSP with smouldering ATLL and a cutaneous ATLL or pre-leukaemic form is discussed.

Adult↗

PubMed1995

[Systemic toxocariasis in the adult patient].

We report a retrospective review of eight patients (one male), aged 19 to 31 years old, with systemic toxocariasis (visceral larva migrans), seen at the Salvador Hospital of Santiago. Four cases had heart involvement, three had lung involvement and in two, several organs were affected. Seven cases had leukocytosis (range 14, 5 to 160 x 10(9)/l) and all had eosinophilia (35 to 90%). Serum ELISA titers for Toxocara sp were positive in all cases, ranging from 64 to 1000. Six patients were treated with thiabendazole and one with albendazole. Steroids or hydroxiurea were administered to patients with heart failure or hyperleukocytosis. Subjects with lung involvement recovered quickly but those with cardiac compromise had a partial recovery with frequent decompensations of their cardiac failure and one death. Eosinophilia lasted up to 20 years, in spite of specific treatment. We emphasize the importance of infection prevention, accuracy of diagnosis and the severity of cardiac damage in the adult patient.

Adult↗

PubMed1995

Rapid intraclonal switch of lineage dominance in congenital leukaemia with a MLL gene rearrangement.

We describe a case of neonatal mixed lineage leukaemia which presented with a dominant B progenitor lymphoblast population plus a minor monocytic component. Treatment of the patient with corticosteroid and Ara-C resulted in loss of lymphoblasts and a rapid (within 7 days) increase and dominance of the monocytic component. The common clonal origin of the two cell types was evident from the identical rearrangement in the MLL gene and a shared rearrangement of one IGH allele. In common with other neonatal or infant ALL with MLL gene rearrangements, this leukaemia may have originated in a common B-monocytic lineage stem cell during foetal haemopoiesis. The observations further suggest that the therapeutic impact of the MLL gene rearrangement is to some extent dependent on the cellular context in which it is expressed.

DNA-Binding Proteins↗

PubMed1994

An expanded scoring system including an index of nutritional status for patients with cystic fibrosis.

Evaluation of success or failure of therapy for patients with cystic fibrosis (CF) commonly relies on the results of a single pulmonary function test (PFT). Most PFT measurements reflect different functional aspects of the lung. Although no single parameter can summarize all aspects of lung function, a combination of several may provide an advantage by reflecting the overall abnormality of lung function in one number. Cropp et al. (1982, Am Rev Respir Dis 126:211-216) developed a multiparameter pulmonary function score (PFS) using the results of six separate parameters obtained from a PFT. In CF, there is also the potential for declining nutritional status (NS), leading to malnutrition and skeletal muscle wasting. Our aim was to expand the PFS by including weighted information on NS, and to determine whether the expanded score (nutritional-pulmonary function score, NPFS) was more sensitive in detecting change in outcome variables than the PFS. Individual PFT parameters, percent ideal body weight (%IBW), and an index of anaerobic performance (AP) were measured in 21 patients on admission to the hospital and again at discharge. In the group as a whole, in-hospital therapy resulted in improvement (P < 0.01) in individual PFT parameters, %IBW, PFS, and NPFS, and no change in AP. While the PFS more effectively reflected improvement in lung function than did any single PFT parameter, the NPFS resulted in an even more sensitive index of change. Based on these results, we believe that the NPFS, which includes both lung and nutritional status, provides an effective and sensitive index of disease severity that can be used as a unifying measure to: 1) detect disease progression; 2) guide rehabilitation and training; 3) stratify patients for clinical trials; or 4) evaluate the effects of a therapeutic intervention.

Adolescent↗

PubMed1994

[Prolymphocytic leukemia, description of 2 cases].

We present the clinical and laboratory features of 2 patients with B prolymphocytic leukemia. Both are females of the fifth and seventh decade of life. One had the classical clinical picture of massive splenomegaly and a high white cell count, with characteristic prolymphocytes, and the other was asymptomatic, with a low white cell count. The cells were positive to B cell lineage reagents with strong surface immunoglobuline (Ig) and unreactive to T cell antibodies. Analysis of Ig genes at the DNA level demonstrated that both cases had heavy-chain gene rearrangements, confirming the B-cell origin. These are the first patients of prolymphocytic leukemia described in Chile.

Aged↗

PubMed1994

[Cytogenetic studies of Chilean children with acute lymphoblastic leukemia].

Acute lymphoblastic leukemia (ALL) is the most frequent childhood cancer. The leukemic cells of ALL patients show several well defined numeric and structural chromosomal abnormalities which are universally known for its prognostic implications. We studied a group of 44 children with ALL, to investigate the incidence of chromosome aberrations in ALL, its lymphocyte lineage and some clinical feature associations, and the finding of non previously described aberrations. A high proportion of patients (79.5%) showed chromosomal abnormalities. Most of them had a pseudodiploid karyotype (46 chromosomes), characterized mainly by a translocation. In relation to chromosome number, 27% of them were hyperdiploid with more than 50; 9% hyperdiploid between 47-50 and 7% hypodiploid (less than 46). Among structural aberrations found, were the following recurrent translocations: t (1; 19), t (4; 11), t (9; 22) in 6.8%, 9.1% and 2.3% of cases respectively, all related to an early B immunophenotype. Other translocations found, compromised regions 7q22, 9p21 - 24. Two new translocations in ALL were found: t (1; 5)(q23; q33), apparently balanced, and t (13; 21)(q14; q22), unbalanced. Other recurrent structural changes found were: deletion (6q), (7q), (9p), (11q), (12p), inversion (3q), isochromosome (7q), maker chromosomes and double minutes. The distribution of chromosome abnormalities in this group of patients was in agreement with previous reports from other investigators.

Adolescent↗

PubMed1994

[Primary cerebral lymphoma following+ kidney transplant: a case report and review of the literature].

We report a 30 year old male, presenting eight years after receiving a kidney transplant with intracranial hypertension and two hyperdense masses detected in a brain CAT scan, whose histopathological study revealed a giant cell immunoblastic lymphoma. The patient was successfully treated with chemo and radiotherapy and after 18 months of follow up there is no evidence of tumoral relapse. Immunocompromised patients, specially transplant recipients, had a several fold higher incidence of malignant tumors, specially primary lymphomas of the central nervous system. These are generally of B type, are associated to Epstein Barr virus and have a high mortality. Cancer must be considered in the differential diagnosis of masses of uncertain origin in transplant recipients.

Adult↗

PubMed1994

HTLV-I positive adult T-cell leukaemia/lymphoma (ATLL) in Chile.

We describe the clinical and laboratory features of nine patients born in Chile with HTLV-I-positive adult T-cell leukemia/lymphoma (ATLL). All were adults (median age 51 years) of Caucasian origin without evidence of Indian or foreign extraction and none had been out of the country. The main disease features were organomegaly, cutaneous lesions, hypercalcemia and leukemia with atypical polylobed lymphocytes displaying a CD2+, CD3+, CD4+, CD8-, CD7- T-cell phenotype. Eight patients presented with acute type ATLL and one had a chronic form lasting for 16 months prior to the development of the acute phase. Lymph node histology (three cases) was consistent with a T-cell non-Hodgkin's lymphoma (large and small cells). Antibodies to HTLV-I were detected by ELISA and particle agglutination in the serum from eight of nine patients. DNA analysis showed HTLV-I proviral DNA in all seven cases investigated, including the single serologically negative patient. In five cases, HTLV-I was monoclonally integrated and in one case oligoclonal. In the seventh case viral DNA clonal status was ambiguous. Response to therapy was poor and median survival was 3 months (range 2-20 months). This study provides further evidence that HTLV-I is endemic in Chile, a non-tropical country where the two main diseases associated with HTLV-I, ATLL and TSP, are found.

Adult↗

PubMed1993

In utero rearrangements in the trithorax-related oncogene in infant leukaemias.

The majority (approximately 75%) of infant acute leukaemias have a reciprocal translocation between chromosome 11q23 and one of several partner chromosomes. The gene at 11q23 (named MLL, ALL-1, HRX or HTRX-1; refs 2-6) has been cloned and shares homology with the Drosophila developmental gene trithorax. Rearrangements of this gene (called HRX here) occur in introns and cluster in a region of approximately 10 kb; individual patients have different breakpoints. Here we describe three pairs of infant twins with concordant leukaemia who each share unique (clonal) but non-constitutive HRX rearrangements in their leukaemic cells, providing evidence that the leukaemogenic event originates in utero and unequivocal support for the intra-placental 'metastasis' hypothesis for leukaemia concordance in twins.

Chromosomes, Human, Pair 11↗

PubMed1993

Cardiopulmonary responses to exercise in children with activity sensing rate responsive ventricular pacemakers.

The physiological benefits of activity sensing rate responsive ventricular pacing (VVIR) over fixed rate pacing (VVI) were investigated in 14 children during incremental cycle exercise. Based on their heart rhythm response during exercise, children were divided into two groups. Group I patients (13 +/- 4 years) remained in a paced-only rhythm when exercised. Group II patients (16 +/- 7 years) were paced at rest but converted to sinus rhythm with exercise. In Group I patients, the significant physiological benefits of VVIR over VVI pacing were evidenced by a 51% increase in peak heart rate (HRmax) and a 16% increase in exercise duration and maximum oxygen uptake (VO2max). Additionally, a 27% reduction in peak oxygen pulse (O2Pmax) was found, reflecting a similar decrease in stroke volume. The cardiorespiratory responses of Group I and II patients were compared in terms of percent of predicted normal values. Although Group I patients in the VVIR mode attained a better exercise performance than in the VVI mode and a normal O2Pmax (108% pred), their HRmax (62% pred) and VO2max (70% pred) fell far below normal values. In comparison, Group II patients, who went into sinus rhythm, achieved normal values for HRmax (84% pred), VO2max (90% pred), and O2Pmax (97% pred). The higher pacing rates attained by Group I patients in the VVIR mode may have allowed them to reach not only a higher cardiac output but also a more normal stroke volume at peak exercise than in the VVI mode.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1993

Geographical distribution of acute lymphoblastic leukaemia subtypes: second report of the collaborative group study.

Childhood acute lymphoblastic leukemia (ALL) T and B precursor subtypes have been identified by standardised immunophenotyping in different geographic and ethnic settings. Comparison of the relative frequencies and estimated incidence rates of the major subtypes indicates very similar values, with the striking exception of black childhood populations in Africa in which there appears to be a significant and selective deficit in the incidence of the common (B-cell precursor) subset of ALL. There is suggestive evidence for a similar bias in ALL subtypes in South Africans of mixed ethnic origin and in Mapuche Indians from Chile. Several interpretations of these data are possible but the one favoured attributes these differences primarily to socio-economic factors and patterns of infection in infancy.

Adolescent↗

PubMed1992

[Mixed myelocytic and lymphocytic acute leukemia. Case report].

A patient with acute mixed myelocytic and lymphocytic leukemia is reported. The patient showed two populations of malignant myeloid and lymphoid cells with predominance of myeloid lineage. According to the present knowledge, it is hypothesized that its origin is at a pluripotent transformed stem cell which has the capability of differentiating through myeloid and lymphoid lineages. Its maturation is arrested at certain level, thus raising two monoclonal populations simultaneously in the same patient. The treatment should be combined with drugs used in acute myeloblastic and lymphoblastic leukemia. The response to chemotherapy is generally poor.

Adult↗

PubMed1992

[Immunologic study of lymphoproliferative diseases].

Thirty six patients with stage IV lymphoproliferative diseases, were studied with a panel of monoclonal antibodies. There were 26 B-Lymphoproliferative Diseases (BLD): 11 B-chronic lymphocytic leukemia, 15 B-cell non Hodgkin lymphoma and 10 T-Lymphoproliferative Diseases (TLD): 4 T-cell non Hodgkin lymphoma, 4 adult T-cell leukemia/lymphoma, 1 T-chronic lymphocytic leukemia and 1 Sezary Syndrome. HLA-DR and CD 19 (B4) were the most common antigens found in BLD. CD4 + CD8 was the most common phenotype in TLD. 13 out of 26 BLD and 1 out of 10 TLD, patient were alive at the end of a 4 year observation period. Our study shows that immunophenotyping is a very useful diagnostic test in lymphoproliferative diseases. Along with cytology and histopathology, it can better define different pathologic groups and lead more specific treatments.

Adolescent↗

PubMed1991

Noninvasive estimation of cardiac output with nonprescribed breathing.

A noninvasive method to estimate cardiac output Q without special patient cooperation was developed by modifying a previous acetylene-helium (C2H2-He) rebreathing technique (ART). Estimation of Q using ART is based on a single-compartment model that is valid only under prescribed breathing; e.g., fast, deep breathing, and emptying of the rebreathing bag on each breath. To make the ART less dependent on subject cooperation, a more sophisticated mathematical model and estimation method are needed. For this purpose, we modeled the C2H2 and He concentration dynamics at the mouth over successive breaths using a multi-compartment model. This model takes into account the effects of breathing pattern, compartmental volumes, and gas solubility. From computer simulations and sensitivity analysis, we found that Q could be estimated from the available data with adequate precision. Our model and estimation method were tested on a group of six normal adult subjects, at rest and during submaximal exercise (75 watts). Estimates of Q from our new method (6.5 +/- 0.4 L/min at rest, 12.5 +/- 0.4 L/min at 75 watts) were in agreement with those obtained using a previous ART (7.0 +/- 0.3 L/min at rest, 12.6 +/- 0.5 L/min at 75 watts). We conclude that this approach promises to provide reliable estimates of Q in patients (e.g., children and elderly), at rest and during exercise, without the need of prescribed breathing patterns or changes in rebreathing bag volume.

Acetylene↗

PubMed1991

Simultaneous adult T-cell leukemia/lymphoma and sub-acute polyneuropathy in a patient from Chile.

This paper reports a case of adult T-cell leukemia/lymphoma associated with human T-cell lymphotropic virus type I (HTLV-I) diagnosed in a Chilean patient who developed after 1 1/2 years a crisis with a progressive sensorimotor polyneuropathy. Serum and cerebrospinal fluid HTLV-I antibody tests were positive and HTLV-I DNA was clonally integrated in peripheral lymphocytes. This case is unusual in having simultaneous neurological disease. Along with other recent data from South America, this suggests that the endemic area of HTLV-I may spread far beyond the Caribbean area.

Adult↗

PubMed1990

Immunologic classification of acute lymphoblastic leukemia.

The study of cell surface antigens in acute lymphoblastic leukemia (ALL) has provided the basic information for classification of ALL into B cell or T cell lineage. Each immunologic type may present at an immature or more mature stage of maturation. This classification has prognostic significance since mature B cell and T cell ALL phenotypes have a worse prognosis, compared to common acute lymphoblastic leukemia-associated antigen (CALLA) positive leukemias that belong to an immature B cell lineage and have the best prognosis. By performing these immunologic studies together with those of molecular biology, it is now possible to establish the precise level of cell differentiation, the point at which the malignant transformation occurred. Further studies may allow correlation of these different maturation stages, thus providing insight into the biologic behavior of lymphoblastic leukemia.

Adenosine Deaminase↗

PubMed1989

[Von Willebrand's disease in the IX Region of Chile].

Bleeding disorders are frequent indications for reference to Hematologic Clinics. Won Willebrand's disease (vWD) is one of the commonest of inheritable hemorrhagic diathesis. In order to evaluate the frequency and clinical characteristics of vWD in the IX Region of Chile, we performed a clinical and laboratory investigation in 132 patients, children and adults, over a period of 3 years: 1983-1985. Within this group there was 26 close relatives. The laboratory tests used for the diagnosis were: bleeding time, factor VIII, von Willebrand factor and ristocetin cofactor. Diagnosis of vWD was made in 83 cases, most of them presenting the mild form of the disease. Two children had the severe form. The estimated prevalence of vWD in symptomatic patients in the IX Region of Chile is at least 113 per million, which makes it 3 or 4 times more frequent than hemophilia. vWD is observed at a much lower rate in mapuche than in caucasian population. The symptoms and their frequency were: post partum bleeding 75%, dental extraction bleeding 65%, surgical bleeding 65%, epistaxis 63%, menorrhagia 54%, easy bruising 45%, deep hematomas 8% and petechiae 5%. Five cases were asymptomatic. The bleeding time was the test most frequently abnormal: 72/83 cases (87%).

Adolescent↗