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Biomedical subjects

J L Navarro

Publications and source records attributed to J L Navarro.

At least 19 recordsLinked to original sources
PubMed1999

Apo E influences declarative and procedural learning in age-associated memory impairment.

Age-associated memory impairment (AAMI) is a clinical entity which was originally described to define memory problems linked to normal aging. Apolipoprotein E and ACE genes have both been associated with cognitive impairment in aging and dementia. The purpose of this study was to investigate memory and executive functions in AAMI according to the genetic background. We found that subjects carrying the Apo E epsilon4 allele exhibit lower memory performance on tests of both declarative and procedural memory. We did not find differences on frontal lobe tests. These findings give further support to the hypothesis concerning a genetic susceptibility for cognitive impairment in aging.

Aged↗
PubMed1999

Expression of Bcl-2 by human bone marrow mast cells and its overexpression in mast cell leukemia.

Bcl-2 protein plays a major role in the prevention of programmed cell death of differentiating cells. In the present study, the expression of cytoplasmic bcl-2 by human Bone Marrow Mast Cells (BMMC) from both normal and pathological bone marrow samples was examined. A total of 35 subjects corresponding to 9 healthy volunteers, 8 cases of adult indolent systemic mast cell disease (SMCD), 4 cases of pediatric mastocytosis (PM), 11 cases of hematological malignancies (HM), 2 cases of reactive bone marrow, and 1 case of mast cell leukemia (MCL) were analyzed. The expression of bcl-2 was studied using quantitative three-color flow cytometry. We also studied the molecular configuration of the bcl-2 gene and other relatives by Southern blot and polymerase chain reaction (PCR) in the MCL case. Bcl-2 expression was detected in BMMC from all samples analyzed. No significant differences on the expression of bcl-2 were detected between BMMC from healthy subjects and patients with SMCD, PM, HM, and reactive bone marrow. By contrast, bcl-2 protein was overexpressed in BMMC from MCL patient without gene rearrangement. Our results show that bcl-2 protein was constitutively expressed by BMMC. BMMC from MCL display overexpression of bcl-2, which could not be related to molecular rearrangements involving the bcl-2 gene. The expression of this protein by mature MC may play a role in the prevention of MC apoptosis and thus help to explain the long survival of these cells. The overexpression of bcl-2 by BMMC in MCL may help to explain their resistance to chemotherapy-induced apoptosis.

Adult↗
PubMed1999

Molecular analysis of HLA class I alleles in the Mexican Seri Indians: implications for their origin.

The molecular analysis of HLA class I loci has demonstrated that, although, the genetic profile is restricted in Amerindians, several micropolymorphisms may be important in conferring a biological advantage. We analyzed the HLA-A and B genetic profile of Seris, a Mexican Indian tribe living in northwestern Mexico in the state of Sonora. There are presently only 619 individuals. Our study included 100 Seris belonging to nine families. HLA-A and -B loci typing was performed by polymerase chain reaction using an amplification refractory mutation system (PCR-ARMS) on a select group of samples; all of them were typed by polymerase chain reaction using sequence-specific oliogonuoleotide probes (PCR-SSOP) at a low-intermediate resolution level. The correlation between the techniques was 100%. Only five HLA-A alleles and seven HLA-B alleles were found. A*0201, A*68, A*31, A*24, B*3501, B*40, B*51, B*3512 and B*15 were present in over 5% of the individuals. B*27052 was detected in 2%. B27 is absent in any other Mexican Indian groups previously studied. The presence of B27 may be the result of a founder effect due to different waves of southward migrations. The B-locus is more diverse and the prevalent haplotypes were: A*0201-B*3501, A*0201-B*40, A*0201-B*3512, A*31-B*51, A*68-B*3501 and A*68-B*40. This genetic profile is different from the pattern of other Mexicans. The phylogenetic tree suggests that Seris are more closely related to the Warao Indians from Venezuela, who live in a similar ecosystem, and to some groups of Argentina, than they are to the Mexican Lacandones who live in the jungle. These data emphasize the relevance of the interaction between genes and environment.

Genetics, Population↗
PubMed1999

The CD69 early activation molecule is overexpressed in human bone marrow mast cells from adults with indolent systemic mast cell disease.

We have analysed the quantitative expression of surface CD69 antigen on human mast cells (MC), from both normal and pathological bone marrow (BM) samples, using flow cytometry. Our major aim was to analyse whether CD69 is constitutively expressed by normal BMMC and to explore the possible differences between CD69 expression by BMMC from normal controls and patients suffering from different pathological conditions. The constitutive expression of surface CD69 was clearly demonstrated in BMMC; however, systemic mast cell disease (SMCD) patients showed significantly higher levels of surface CD69 expression than healthy controls (P < 0.001), chronic lymphocytic leukaemia (P = 0.001), monoclonal gammopathy of unknown significance (P < 0.001), multiple myeloma (P < 0.001) patients, and myelodysplastic syndromes (P = 0.002). Furthermore, almost no overlap between the levels of CD69 expression on BMMC was observed between SMCD cases and the remaining groups of individuals except for the paediatric mastocytosis group (P > 0.05). From the other groups of patients, monoclonal gammopathy of unknown significance (P = 0.04), myelodysplastic syndromes (P = 0.03) and paediatric mastocytosis (P = 0.003) cases showed a significantly higher expression of surface CD69 as compared to normal subjects. In summary, our findings show that the CD69 antigen is overexpressed in SMCD patients.

Adolescent↗
PubMed1998

[Von Willebrand disease: characteristics and response to desmopressin. Study of 103 cases].

BACKGROUND: To describe the main characteristics and response to desmopressin infusion in 103 patients suffering from von Willebrand disease (vWD). PATIENTS AND METHODS: The criteria for diagnosis were (except for type 2N) the coexistence of von Willebrand factor ristocetin cofactor (vWF:RCo) activity < 50 U/dl with bleeding disease or one of the following data: von Willebrand factor antigen (vWF:Ag) activity < 50 U/dl, factor VIII (FVIII) activity < 50 U/dl or the existence of a increased bleeding time (BT). Multimeric studies of vWF were performed in 51 cases and ristocetin induced platelet aggregation (RIPA) was also performed. RESULTS: Spontaneous bleeding was found in 36 patients, while in 18 cases the diagnosis was done after surgical bleeding. Thirteen patients (6 presenting with mild bleeding) were studied for abnormalities in the routine preanestesic tests. Other 22 patients were diagnosed with vWD by familial studies. There were 3 patients with type 2B, 1 case with type 2N and other patient with type 3. BT was found increased in 26 out of 58 patients. The activities of vWF:CoR and vWF:Ag were 38.4 (9.4) U/dl and 45.8 (23.2) U/dl, respectively, while the activity of FVIII was 49.9 (20.8) U/dl. Prophylactic DDAVP (desmopressin) was infused in 32 patients. After 1 h, basal activities of vWF:CoR and vWF:Ag were increased by 3.1 (3.2) and 3.4 (3.1) times, respectively, and maintained for 3 h. FVIII activity increased 3.6 (2.3) times the basal levels decreasing after 3 h (2.9 [2.1]; p < 0.01). The BT was corrected in 8 out of ten patients. CONCLUSIONS: vWD is a major cause of surgical bleeding. Preanestesic anamnesis and coagulation tests can be useful to identify vWD. Many patients with vWD have normal BT. A failure in the response to desmopressin infusion is unusual.

Deamino Arginine Vasopressin↗
PubMed1998

Human bone marrow mast cells from indolent systemic mast cell disease constitutively express increased amounts of the CD63 protein on their surface.

The quantitative measurement of the expression of both cytoplasmic and surface CD63 antigen by human mast cells from both normal and pathological bone marrow samples was studied by use of flow cytometry. Our major goal was to analyze whether in vivo CD63 expression by human bone marrow mast cells could be useful to discriminate bone marrow mast cells from patients with mastocytosis from other conditions. For that purpose, a total of 65 subjects corresponding to 12 healthy volunteers, 25 B-cell chronic lymphoproliferative disorders, 5 reactive bone marrow samples, 4 myelodysplastic syndromes, and 19 mastocytosis were analyzed. The expression of both surface and cytoplasmic CD63 by human bone marrow mast cells is clearly demonstrated. Our results show that high amounts of CD63 are present in human bone marrow mast cells most of it corresponding to an intracellular localization. No significant differences in CD63 expression were observed as regards both total and cytoplasmic CD63, except for higher CD63 levels in adult patients with mastocytosis (P = 0.05). By contrast, the mean level of surface CD63 significantly varied between the different groups of individuals. Accordingly, patients with monoclonal gammopathies displayed a slight decrease (P = 0.1) in surface CD63 expression, whereas bone marrow mast cells from adults with indolent systemic mast cell disease showed significantly (P = 0.0005) higher levels of surface CD63 as compared to healthy controls.

Adult↗
PubMed1998

Indolent systemic mast cell disease in adults: immunophenotypic characterization of bone marrow mast cells and its diagnostic implications.

The aim of the present study was to explore the diagnostic value of the immunophenotypic analysis of bone marrow mast cells (BMMC) in indolent systemic mast cell disease (SMCD) patients. For that purpose, a total of 10 SMCD patients and 19 healthy controls were analyzed. Our results show that BMMC from SMCD are different from normal BMMC with regard to both their light scatter and immunophenotypic characteristics. Accordingly, forward light scatter (FSC), side (90 degrees) light scatter (SSC), and baseline autofluorescence levels were higher in BMMC from indolent SMCD patients than they were in control subjects. From the immunophenotypic point of view, the most striking findings were the constant expression of CD2 (P = .0001), CD25 (P = .0001), and CD35 (P = .06) molecules by BMMC from SMCD patients, markers that were absent from all normal controls. In contrast, CD71, absent in BMMC from indolent SMCD, was positive in BMMC from normal subjects. Although, slight differences between BMMC from SMCD patients and normal controls were found in several other markers, they did not reach statistical significance. In conclusion, our results show that simultaneous assessment of FSC/SSC and reactivity for the CD117, CD2, CD25, CD33, and CD35 forms the basis for the immunophenotypic characterization of BMMC from SMCD in adults and should be integrated with clinical and morphologic studies for the diagnosis of the disease.

Adult↗
PubMed1998

Degree of hypercoagulability and hyperfibrinolysis is related to organ failure and prognosis after burn trauma.

Severely burned patients often present a hypercoagulability situation. However, its magnitude, time course, and relationship with organ failure and outcome remains to be established. Forty-three patients were studied on the first and seventh day after burn for hypercoagulability and fibrinolysis parameters. A hypercoagulability and hyperfibrinolysis state was found the first day after burn demonstrated by high levels of activated factor VII (VIIa, p<0.01), thrombin-antithrombin III complex (TAT, p<0.01), tissue plasminogen activator (t-PA, p<0.001) and D dimer (DD, p<0.01) and low levels of antithrombin III (ATIII, p<0.01), protein C (PC, p<0.01), plasminogen (PG, p<0.001) and alpha2 antiplasmin (AP, p<0.001). A paradoxical coexisting hypofibrinolysis was found as suggested by a low global fibrinolytic activity in the euglobulin plasma fraction fibrin plate assay (FA, p<0.01) and high levels of tissue plasminogen activator inhibitor type 1 (PAI-1, p<0.01). On day 7, a less marked hypercoagulability situation was found, with low ATIII (p<0.01) and PC (p<0.01), persisting the hypofibrinolytic situation observed on the first day. Non-survivors (NS) showed higher levels of VIIa (p<0.01), TAT (p<0.05) and t-PA (p<0.05), and lower levels of ATIII (p<0.05), PC (p<0.05) and AP (p<0.001) than survivors (S) on the first day. Also, there was a positive correlation of Marshall organ failure score with ATIII, (r2=0.49, p<0.001), PC, (r2=0.14, p<0.045) and PG levels, (r2=0.41, p<0.0003). Severely burned patients show a state of transient disseminated intravascular coagulation, related to the development of organ failure and outcome.

Adult↗
PubMed1998

Immunophenotypic characterization of human bone marrow mast cells. A flow cytometric study of normal and pathological bone marrow samples.

The goal of the present paper was to define the immunophenotype of bone marrow mast cells (BMMC) from healthy controls and patients with hematologic malignancies (HM) based on the use of multiple stainings with monoclonal antibodies analyzed by flow cytometry. Our results show that BMMC from both groups of individuals display a similar but heterogeneous immunophenotype. The overall numbers of BMMC are higher in the HM group of individuals (p = 0.08). Three patterns of antigen expression were detected: (1) markers constantly positive in all cases analyzed (CD9, CD29, CD33, CD43, CD44, CD49d, CD49e, CD51, CD71, CD117, and Fc(epsilon)RI), (2) antigens that were constantly negative (CD1a, CD2, CD3, CD5, CD6, CD11a, CD14, CD15, CD16, CD19, CD20, CD21, CD23, CD25, CD30, CD34, CD38, CD41a, CD42b, CD65, CD66b, HLA-DR, and CD138), and (3) markers that were positive in a variable proportion of cases--CD11b (50%), CD11c (77%), CD13 (40%), CD18 (20%), CD22 (68%), CD35 (27%), CD40 (67%), CD54 (88%) and CD61 (40%). In addition, BMMC from all cases explored were CD45+, and this antigen was expressed at an intensity similar to that of mature granulocytes. In summary, our results show that BMMC from both healthy controls and HM patients display a relatively heterogeneous immunophenotype. Interestingly, we have observed clear differences between the immunophenotype of BMMC and MC from other tissues. This could be due either to the heterogeneity of human MC according to their tissue localization or to the sensitivity of the method used for antigen detection.

Antibodies, Monoclonal↗
PubMed1998

Controlled-rate versus uncontrolled-rate cryopreservation of peripheral blood progenitor cells: a prospective multicenter study. Group for Cryobiology and Biology of Bone Marrow Transplantation (CBTMO), Spain.

BACKGROUND AND OBJECTIVE: Cryopreservation of hemopoietic progenitors for transplantation has been traditionally performed by the use of a controlled-rate freezer. Several groups have reported successful cryopreservation of progenitor cells at -80 degrees C without a controlled-rate freezer. In an attempt to elucidate whether both methods are equally efficient, we compared controlled-rate versus uncontrolled cryopreservation of peripheral blood progenitor cells (PBPC) in a prospective, multicenter study. DESIGN AND METHODS: Apheresis products from patients undergoing PBPC mobilization were split into two aliquots, and cryopreserved simultaneously by both methods, in autologous plasma plus 10% dimethylsulfoxide. Controlled-rate samples were placed into a programmable freezer with a cooling rate of 1-2 degrees C/min. Uncontrolled-rate samples were directly introduced into a -80 degrees C mechanical freezer. After thawing, cell counts, assays for viability, clonogenic cultures and CD34+ cell enumeration were performed. RESULTS: A total of 105 cases were included. No significant differences were found in viability (mean 88.8 +/- 13% in the controlled-rate group vs. 89.7 +/- 12% in the uncontrolled-rate group), nucleated cell loss (23.5 +/- 23% vs. 23 +/- 22%), mononuclear cell loss (19 +/- 23% vs. 19.1 +/- 22%), and loss of CD34+ cells (34.3 +/- 33% vs. 28.6 +/- 34%). On the other hand, recovery of granulomonocytic colony-forming units (CFU-GM), was significantly better with the controlled-rate technique, than with the non-controlled-rate method (104.3 +/- 95 vs. 86.5 +/- 80, respectively; p = 0.048). INTERPRETATION AND CONCLUSIONS: Our results indicate that both techniques are suitable for cryopreservation of PBPC, although a better recovery of committed progenitors is achieved by the controlled-rate method. Therefore, the use of controlled-rate freezer should probably be recommended.

Blood Preservation↗
PubMed1997

Carcase and component yields of rheas.

1. Three Greater Rheas (Rhea americana) and 5 Lesser Rheas (Pterocnemia pennata) were slaughtered, using the procedures conventional for ostriches in South Africa, in order to determine the expected yield of by-products and saleable lean meat, fat and bone of rheas. 2. Differences (P < 0.05) between species were found in the proportional weight of the wings, feet, skin and liver. The wings, feet and head of rheas form a higher proportion of the carcase than in ostriches, whereas the skin of the former represents a lower percentage of body weight. 3. Lean meat production from rheas (64% on a carcase weight basis) is in the same order as for ostriches, broilers, turkeys and beef.

Adipose Tissue↗
PubMed1996

Plasma phospholipids and platelet function in uremic patients.

An increased activity of phospholipase A2 has been observed in the plasma of patients with uremia. This enzyme converts phosphatidylcholine to lysophosphatidylcholine (LPC), an inhibitor of platelet aggregation. We measured the levels of plasma phospholipids including LPC, and platelet aggregation in 7 patients with uremia. Platelet response to agonists was defective, mainly with collagen (p < 0.001). The patients' levels of LPC in plasma were similar to those of controls (109.7 +/- 41.6 vs. 80.4 +/- 16.8 nmol/ml) and did not correlate with the platelet response to adenosine diphosphate (r = -0.51). The amount of phosphatidylcholine was increased with respect to normal plasma (1,041.0 +/- 201.8 vs. 760.8 +/- 142.7 nmol/ml, p < 0.01), while the levels of other phospholipids were normal. These results do not suggest a participation of plasma LPC in the genesis of the platelet defect observed in patients with uremia.

Adolescent↗
PubMed1996

Platelets isolated by albumin gradient retain normal activation pathways.

Isolated platelets from samples with low counts produce technical problems. Albumin gradient (AG) has been shown to be useful for this purpose, preserving the aggregating response of these cells. The influence of this method in the enzymatic pathways that regulate the platelet activation is studied. Platelets were isolated by either AG or conventional centrifugation methods and labelled with C-14-arachidonic acid (C-14-AA). Isolated platelets were activated with thrombin (5 U/ml) and lipids were extracted according to Bligh and Dyer. Platelet phospholipids and prostanoids were resolved by TLC. The incorporation of C-14-AA by platelets was similar by both methods (31.7 +/- 18% versus 47.2 +/- 6.9%), as well as the distribution of C-14-AA in the five major platelet phospholipids. Formation of radioactive thromboxane B2, hydroxyheptadecatrienoic acid and hydroxyeicosatetraenoic acid by activated platelets was also similar by both methods. These findings suggest that platelet isolation by albumin gradient preserves the enzymatic pathways responsible for the activation of these cells.

Albumins↗
PubMed1996

Flow cytometric analysis of mast cells from normal and pathological human bone marrow samples: identification and enumeration.

In the present paper we have used a three-color immunofluorescence procedure combined with flow cytometry cell analysis and sorting for the identification and enumeration of human mast cells in both normal and pathological bone marrow samples. Our results show that bone marrow mast cells are clearly identifiable on the basis of their light-scatter properties and strong CD117 expression. These cells were negative for the CD34, CD38, and BB4 antigens. In addition, they were CD33+ and displayed a high reactivity for the anti-IgE monoclonal antibody. The identity of the CD117-strong+ cells (mast cells) was confirmed by both microscopic examination and flow cytometry analysis. The overall frequency of mast cells in the bone marrow samples analyzed in the present study was constantly lower than 1%. The lowest frequencies corresponded to normal human bone marrow samples (0.0080 +/- 0.0082%) and the highest to those patients suffering from indolent systemic mast cell disease (0.40 +/- 0.13%). In summary, our results show that the identification and enumeration of bone marrow mast cells can be achieved using multiparametric flow cytometry. Moreover, once identified, mast cells are suitable for being characterized from the phenotypic and the functional point of view, facilitating the comparison between normal and abnormal mast cells.

Bone Marrow↗
PubMed1995

Arachidonic acid metabolism in platelets of patients with essential thrombocythaemia.

Platelet aggregation tests and studies comprising [14C] arachidonic acid [14C]AA incorporation, release and metabolism were performed in resting and thrombinstimulated platelets of 11 patients with essential thrombocythaemia (ET) and 11 normal subjects. Nine patients had abnormal aggregation tests. Incorporation and distribution of [14C]AA in main platelet phospholipids (PLs) was similar in both groups. Activated platelets of patients with ET released more radioactivity from PLs that controls (13.7 +/- 5.4% versus 8.2 +/- 1.9%, p < 0.01). The formation of 12-L-hydroxy-5,8,10-heptadecatrienoic acid (HHT) was also increased (3.3 +/- 1.4% of total radioactivity versus 1.6 +/- 0.4% in controls (p < 0.0001). The same results were obtained for the generation of thromboxane B2 (p < 0.01). We did not detect differences in the formation of 12-L-hydroxy- 5,8,10,14-eicosatetraenoic acid (3.3 +/- 1.7% in patents versus 2.0 +/- 0.5% in controls). These results indicate that platelets of patients with ET have an increased activity of phospholipases and suggest a facilitated metabolism of arachidonate by the prostaglandinsynthetase pathway. Our results also demonstrate that impairment of aggregation tests in these patients was not due to a defective activity of the enzymes involved in the release and metabolism of AA by platelets.

Adult↗