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Biomedical subjects

F Gilsanz

Publications and source records attributed to F Gilsanz.

At least 19 recordsLinked to original sources
PubMed1997

A markedly disrupted skeletal network with abnormally distributed intramembrane particles in complete protein 4.1-deficient red blood cells (allele 4.1 Madrid): implications regarding a critical role of protein 4.1 in maintenance of the integrity of the red blood cell membrane.

Electron microscopic (EM) studies were performed to clarify the interactions of membrane proteins in the red blood cell membrane structure in situ of a homozygous patient with total deficiency of protein 4.1 who carried a point mutation of the downstream translation initiation codon (AUG --> AGG) of the protein 4.1 gene [the 4.1 (-) Madrid; Dalla Venezia et al, J Clin Invest 90:1713, 1992]. Immunologically, as expected, protein 4.1 was completely missing in the red blood cell membrane structure in situ. A markedly disrupted skeletal network was observed by EM using the quick-freeze deep-etching method and the surface replica method, although the number of spectrin molecules was only minimally reduced (395 +/- 63/microm2; normal, 504 +/- 36/microm2). The number of basic units in the skeletal network was strikingly reduced (131 +/- 21/microm2; normal, 548 +/- 39/microm2), with decreased small-sized units (17 +/- 4/microm2; normal, 384 +/- 52/microm2) and increased large-sized units (64% +/- 14%; normal, 5% +/- 1%). Concomitantly, immuno-EM disclosed striking clustering of spectrin molecules with aggregated ankyrin molecules in the red blood cell membrane structure in situ. Although no quantitative abnormalities in the number and size distribution of the intramembrane particles were observed, there was a disappearance of regular distribution, with many clusters of various sizes, probably reflecting the distorted skeletal network. Therefore, protein 4.1 suggests by EM to play a crucial role in maintenance of the normal integrity of the membrane structure in situ not only of the skeletal network but also of the integral proteins.

Anemia, Hemolytic↗
PubMed1996

The cisternae decorating the red blood cell membrane in congenital dyserythropoietic anemia (type II) originate from the endoplasmic reticulum.

We studied 20 individuals from 17 unrelated families with congenital dyserythropoietic anemia (type II; CDAII). The clinical phenotype was mild to moderate. The inheritance pattern was invariably recessive. Coomassie blue stained gels after sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) show that band 3 was thinner and migrated slightly faster than usual. In addition, staining showed two unknown minor bands (in the patients), but not in normal controls, the obligate carrier parents, or in patients with other anemic syndromes. These minor proteins were studied using partial digestion, amino acid sequencing, Western blotting, immunofluorescence, and immunogold electron microscopy. They were identified as the glucose-regulated protein GRP78 and calreticulin that are resident proteins of the endoplasmic reticulum (ER). Using specific antibody, we showed that protein disulfide isomerase (PDI), a third major protein of the ER, was also present on the SDS-PAGE of red blood cell (RBC) ghosts. Immunofluorescence colocalized PDI with the dense discontinuous ring decorating the RBC membrane. Immunogold electron microscopy showed that PDI was localized in the lumen of the cisternae, confirming that these originate from the smooth ER. From a practical point of view, screening the above minor proteins in RBC membranes appears to be a straightforward and reliable diagnostic test for CDAII.

Amino Acid Sequence↗
PubMed1996

Assessment of the severity of hereditary spherocytosis using routine haematological data obtained with dual angle laser scattering cytometry.

Dual angle laser scattering cytometry (DALC) measures erythrocyte volume and haemoglobin concentration directly and provides spherocyte quantification. We have studied DALC red cell features in hereditary spherocytosis (HS) relating them to the clinical severity of the illness. A total of 140 controls and 80 non-splenectomized HS cases were studied, with mild (n = 32), moderate (n = 37) and severe (n = 11) disease. DALC measured mean corpuscular haemoglobin concentration, percentage of erythrocytes with haemoglobin concentration over 410 g/l (%Hyper), red cell volume and haemoglobin concentration distribution widths which were significantly different in HS cases when compared with controls (P < 0.001). Severe HS cases had more heterogeneous erythrocyte populations, both in volume and haemoglobin concentration (P < 0.001). Clinical severity of HS was best reflected by erythrocyte volume distribution width followed by %Hyper. DALC red cell features are both a diagnostic tool and an index to the severity of HS.

Adolescent↗
PubMed1996

Hemolytic anemia in chronic large granular lymphocytic leukemia of natural killer cells: cytotoxicity of natural killer cells against autologous red cells is associated with hemolysis.

BACKGROUND: It has ben suggested that natural killer cells are effectors in some hemolytic transfusion reactions, but a direct mechanism of the destruction of red cells has not been demonstrated. CASE REPORT: Lytic activity of natural killer cells against autologous red cells was found in a patient with large granular lymphocytic leukemia of natural killer cells and hemolytic anemia, with no evidence of immune antibody or complement-mediated hemolysis. Large granular lymphocytes in the blood showed a CD2+ CD3- CD16+ CD57+ phenotype, cytotoxic activity against natural killer cell-sensitive K562 target cells, and no lytic activity against natural killer cell-resistant JY target cells. Cytotoxicity directed against red cells was quantified by a 51Cr-specific release assay with autologous and ABO-identical red cells used as target cells and the patients purified natural killer cells used as effector cells in the presence and absence of autologous serum. The cytotoxic activity of natural killer cells was directed against autologous red cells but not against allogenic red cells, and it was not enhanced by the presence of autologous serum in the medium. Clinical remission was induced by the administration of cyclophosphamide, after which no evidence of cytotoxic activity against the red cells could be found. CONCLUSION: Hemolytic anemia in the presence of a negative direct antiglobulin test can be attributed to a direct cytotoxic mechanism mediated by natural killer cells.

Aged↗
PubMed1996

[Reference values in the diagnosis of anemia in the elderly].

OBJECTIVES: To analyze the usefulness of some reference values for erythropoiesis in the elderly. Methods. A total of 226 individuals older than 65 years (139 females and 87 males) were studied with measurements of hemoglobin (Hb), corpuscular indexes, red blood cell distribution index, serum iron level, ferritin and creatinine. Plasma erythropoietin (EPO) was determined in 72 cases. Values were grouped according to age, younger (126) and older than 76 years (100), and sex. RESULTS: Hb was lower in males older than 76 years than in individuals younger than 76 years but this differences was not observed among women. Serum iron level was low in 13.3% of individuals. Creatinine was higher among males than among women and higher among males younger than 76 years than in males older than 76 years. EPO was higher among the elderly patients than in young adults (p < 0.001), keeping no relationship with age. CONCLUSIONS: With the exception of EPO, the usual reference values for erythropoiesis in the adults can be used for the elderly patients. Despite differences in EPO compared with adults, the quantitation of this finding is useless for the diagnosis of anemia in the elderly.

Aged↗
PubMed1996

Quinton-Mahurkar catheter as short-term central venous access for PBSC collection: single-center experience of 370 aphereses in 110 patients.

We retrospectively analyzed our experience with the Quinton-Mahurkar dual-lumen hemodialysis catheter as short-term central venous access for harvesting peripheral blood stem cells (PBSC) for autologous transplantation. For intensification therapy for various malignancies 370 leukaphereses were performed in 110 candidates. The catheter was placed percutaneously under local anesthesia only for the time of blood collection and in no case was it used for the PBSC transplant. No systemic antithrombotic prophylaxis was administered. PBSC were collected using a continuous flow cell separator, COBE Spectra, after mobilization with chemotherapy followed by cytokine: rhGM-CSF and rhG-CSF s.c. (35 patients) or rhG-CSF s.c. alone (75 patients). The median number of aphereses was two (1-13). Eighty-nine patients (81.3%) required three or fewer sessions to collect the minimum mononuclear cell target number of 6 x 10(8) MNC/kg. The volume of blood per kg body weight processed for each apheresis was 240 ml (range 150-560 ml) equivalent to 13 l (6-30 l) and the median flow rate was 61 ml/min (range 30-90 ml/min). The total CD34+ cell yield per patient was 3.55 x 10(6)/kg (0.26-34.8) and the MNC yield was 6.1 x 10(8)/kg (2.96-12.6). We observed the following complications: local infection in four cases (3.6%), catheter occlusion for local thrombosis in two cases (1.8%) and pneumothorax in one case (0.97%). In our experience the Mahurkar-Quinton catheter, when placed specifically for apheresis sessions, was very effective and safe for PBSC harvesting with a low incidence of complications.

Catheterization, Central Venous↗
PubMed1996

The effect of splenectomy in hereditary spherocytosis by dual angle laser light cytometry.

We have applied dual angle laser scattering cytometry (DALC), which provides objective assessment of spherocytosis, to study the changes of hereditary spherocytosis (HS) red cell populations after splenectomy. Eighty unsplenectomized HS patients (32 mild, 37 moderate and 11 severe cases), 26 splenectomized HS patients (SHS, formerly 21 moderate and five severe cases) and 140 controls were studied. SHS were similar to unsplenectomized mild HS cases, with homogeneous red cell volume distribution and spherocytosis. Spherocytosis in SHS was significantly higher when compared with controls (P < 0.001) but less when compared with unsplenectomized HS patients (P < 0.01).

Adolescent↗
PubMed1995

Acquired pure red cell aplasia: a study of six cases.

Persistent infection by parvovirus B19 associated with pure red cell aplasia (PRCA) has been documented in immunocompromised patients. Bone marrow failure is associated with conditions in which immune surveillance is impaired, and in these instances occult parvovirus infection may be suspected. In this study we have assessed by serological and molecular methods whether parvovirus B19 infection may be a more frequent cause of PRCA than hitherto suspected and whether it may be present in the absence of a typical bone marrow picture. Six patients with PRCA--two with isolated PRCA and no apparent underlying disease, two with a lymphoproliferative disease, one with thymoma, and one with chronic myelomonocytic leukemia--have been studied. Four of the six patients had overt PCRA and were clearly immunocompromised. Parvovirus B19 was not detected in any of the six patients by PCR analysis and serology investigating the presence of IgM or IgG antibodies. Although parvovirus B19 infection needs to be ruled out in PRCA it represents only one, and probably not the most frequent, etiological factor of PRCA.

Adult↗
PubMed1993

Hb Villaverde [beta 89 (F5) Ser-->Thr]: the structural modification of an intrasubunit contact is responsible for a high oxygen affinity.

Hb Villaverde [beta 89 (F5) Ser-->Thr], identified in a Spanish patient, is a new human hemoglobin variant, electrophoreticaly silent, responsible for a severe erythrocytosis. This abnormal hemoglobin displays a very high oxygen affinity and a markedly reduced cooperativity that is partly restored in the presence of IHP. Determination of the structural abnormality was achieved on a mixture of the normal and abnormal beta-chains. After isolation of the abnormal tryptic peptide by RP-HPLC, its sequence was determined by mass spectrometry. The structural abnormality disturbs the intrasubunit interaction between helices F and H and, thus, may weaken the C-terminal bonds of the deoxy conformation and the heme contacts of several hydrophobic residues. Hb Villaverde demonstrates that this intrasubunit contact between helices F and H is essential for the cohesion of the hemoglobin molecule.

Adult↗
PubMed1993

Evidence that red blood cell protein p55 may participate in the skeleton-membrane linkage that involves protein 4.1 and glycophorin C.

Human erythrocyte p55 is a peripheral membrane protein that contains three distinct domains in its primary structure: an N-terminal domain, an SH3 motif, and a C-terminal guanylate kinase domain. We used naturally mutated red blood cells (RBCs) with primary genetic defects resulting in the absence of protein 4.1 (4.1[-] hereditary elliptocytosis) or glycophorin C (Leach elliptocytosis). The absence of either protein was associated with the absence of p55. On a stoichiometric basis, the reduction in glycophorin C (about 80%) was concomitant to the lack of p55 in RBCs devoid of protein 4.1. Similarly, the reduction of protein 4.1 (about 20%) was equivalent to the absence of p55 in RBCs devoid of glycophorin C. These correlations suggest that p55 is associated, in precise proportions, with the protein 4.1-glycophorin-C complex, linking the skeleton and the membrane. The protein 4.1-glycophorin-C cross-bridge is known to be critically important for the stability and mechanical properties of human RBC plasma membrane. Because isoforms of protein 4.1, glycophorin C, and p55 exist in many tissues, these results provide evidence of a linkage between the skeleton and the membrane that may have implications in many nonerythroid cells.

Blood Proteins↗
PubMed1993

Diagnosis of hereditary spherocytosis with dual-angle differential light scattering.

Efficacy in the diagnosis of hereditary spherocytosis (HS) using a system of dual-angle differential light scattering of a monochromatic laser beam on sphere-shaped and fixed erythrocytes was evaluated. Fifty-one nonsplenectomized patients with HS, 6 with autoimmune hemolytic anemia, and 140 control subjects were studied. The percentage of erythrocytes with hemoglobin concentration more than 410 g/L (hyperhemoglobin) was significantly different in patients with HS and control subjects (P < 0.001). Hyperhemoglobin could be detected even in the mildest HS, in all patients with autoimmune hemolytic anemia, and in some control subjects, although none of the latter had more than 3%. This technique is extremely sensitive to the presence of spherocytes and the absence of erythrocytes with more than 410 g/L hemoglobin excludes HS. The presence of hyperhemoglobin is not specific for HS and increased amounts of hyperhemoglobin were found in patients with autoimmune hemolytic anemia and control subjects. To make a confident diagnosis of HS, the detection of hyperhemoglobin must be evaluated in the same clinical setting and with the same criteria as those applied to the osmotic fragility test.

Erythrocytes↗
PubMed1993

Fetal anaemia due to pyruvate kinase deficiency.

Pyruvate kinase deficiency was diagnosed in an infant by umbilical vessel sampling at 30 weeks' gestation. Although three previous hydropic siblings had been stillborn or died in the neonatal period, this infant survived with transfusion dependent haemolytic anaemia. Prompt fetal diagnosis of pyruvate kinase deficiency is feasible and allows better management of hydrops fetalis due to this disorder.

Anemia, Hemolytic, Congenital↗
PubMed1992

Cytohematologic and cytogenetic prognostic factors at diagnosis and in the evolution in 46 primary myelodysplastic syndromes.

The myelodysplastic syndromes (MDS) are a heterogeneous group of diseases with different prognosis and evolution. Most of the studies on prognostic factors performed previously have independently evaluated the clinico-hematologic or cytogenetic data at diagnosis. In the present paper, 46 primary MDS were clinically, hematologically, and cytogenetically investigated at diagnosis, in order to determine the principal factors affecting the survival probability between a great number of characteristics. A univariate regression analysis of all the data allows one to recognize that the main factors are: the complexity of karyotype (p = 0.00001), the percentage of type I and total marrow blast cells (p = 0.001), and the abnormal localized immature myeloid precursors' (ALIP) presence (p = 0.001). Twenty-five patients underwent consecutive studies during their evolution. The karyotype instability gives information both on the likely evolution to acute leukemia and on poor survival.

Adult↗
PubMed1992

Chronic ethanol abuse and membrane fluidity changes in liver disease.

The long-term effect of ethanol on human red cell membrane fluidity was studied, by fluorescence polarization with 1,6-diphenyl-1,3,5-hexatriene as a probe, in 11 healthy subjects, 9 chronic alcoholics without evidence of liver disease, 12 chronic alcoholics with biopsy-proven alcoholic liver disease and 9 abstemious patients with chronic active liver disease, most of them cirrhosis of the liver. Fluorescence polarization values were not significantly different in the two groups without liver disease. Patients with alcoholic and non-alcoholic liver disease showed higher fluorescence polarization values than patients without liver disease. These changes correlated with the severity of liver dysfunction and were not related to alcohol consumption. In conclusion, the decrease in fluidity of the erythrocyte membrane in alcoholic patients with chronic liver disease, is related to liver dysfunction but not to chronic ethanol ingestion. Changes in membrane fluidity in chronic alcoholics are found only in the presence of liver disease.

Adult↗
PubMed1992

Homozygous 4.1(-) hereditary elliptocytosis associated with a point mutation in the downstream initiation codon of protein 4.1 gene.

We studied a 43 yr-old Spanish patient with homozygous 4.1(-) hereditary elliptocytosis. Any form of protein 4.1 was missing in the red cells. Spectrin and actin were slightly, yet significantly, diminished. Alterations appeared at the level of proteins 4.5 and 4.9. Glycophorin C was sharply reduced. The abnormal allele was associated with the -++-- haplotype (Pvu II, Bgl II, Bgl II, Pvu II, Pvu II). mRNA 4.1(-) had an apparently normal size but was diminished by about two-thirds. Because the abnormal phenotype pertained to the red cell, we sequenced the 4.1 cDNA regions that appear critical to this cell type. The ultimate change turned out to be a point mutation of the downstream translation initiation codon (AUG-->AGG). No disorders in other cell types could be related with certainty to the present 4.1(-) HE allele.

Adult↗
PubMed1992

Age and sex matched analysis of Hb Lepore trait in a new population in Spain.

A group of subjects with Hb Lepore trait has been found in the region between Extremadura and Toledo in Spain. Clinical, radiological and hematological studies were carried out on 81 cases from 23 families. Asthenia was the sole complaint in seven of forty cases. Abdominal echography showed no cholelithiasis in 16 children under 16 years. Hb Lepore mean was 10.81 +/- 1.97%, range 6.5 to 16.1%, Hb A2 levels were normal and Hb F values were high. Globin chain synthesis in reticulocytes showed a total alpha/beta ratio of 1.89 +/- 0.3. Hematological values from Hb Lepore trait subjects were analyzed according to age and sex and the data compared to beta thalassemia and delta-beta thalassemia cases of matched age and sex. Hb Lepore trait patients had a milder form of thalassemia minor than beta thalassemia patients, with higher levels of hemoglobin, MCV and MCH for all three groups: children under 13 years, males over 14 years and females over 14 years. Children and females with Hb Lepore had higher hemoglobin levels than those with delta-beta thalassemia minor, while no significant difference was found in males.

Adolescent↗