The clinical course of polycythemia vera is often complicated by thrombosis as well as by the pos... more The clinical course of polycythemia vera is often complicated by thrombosis as well as by the possible transition to myeloid metaplasia with myelofibrosis or acute myeloid leukemia. The aim of this study was to assess the rate of these complications in subjects receiving currently recommended treatments.
Proceedings of The National Academy of Sciences, 2006
RNA interference, mediated by small interfering RNAs (siRNAs), is a conserved regulatory process ... more RNA interference, mediated by small interfering RNAs (siRNAs), is a conserved regulatory process that has evolved as an antiviral defense mechanism in plants and animals. It is not known whether host cells also use siRNAs as an antibacterial defense mechanism in eukaryotes. Here, we report the discovery of an endogenous siRNA, nat-siRNAATGB2, that is specifically induced by the bacterial pathogen Pseudomonas syringae carrying effector avrRpt2. We demonstrate that the biogenesis of this siRNA requires DCL1, HYL1, HEN1, RDR6, NRPD1A, and SGS3. Its induction also depends on the cognate host disease resistance gene RPS2 and the NDR1 gene that is required for RPS2-specified resistance. This siRNA contributes to RPS2-mediated race-specific disease resistance by repressing PPRL, a putative negative regulator of the RPS2 resistance pathway.
... see Table 11), and hybridized with the following probes: a 1.8 kb SAC I 5 fragment from the r... more ... see Table 11), and hybridized with the following probes: a 1.8 kb SAC I 5 fragment from the recombi-nant PRB 5, a 1.5 kb Pst I a fragment for the recombinant PRB al, a ... Higgs, DR, Vickers, MA, Wilkie, AOM, Pretorius, IM., Jarman, AP, and Weatherall, DJ, Blood, 73:1081, 1989. ...
Summary. The introduction of molecular biological techniques in the study of chronic myeloid leuk... more Summary. The introduction of molecular biological techniques in the study of chronic myeloid leukaemia (CML) allows us to show the bcr/abl gene rearrangement produced by the translocation between the c-abl proto-oncogene located in chromosome 9 and the bcr region located in chromosome 22, which constitutes the molecular alteration of Philadelphia chromosome in CML. We present the usefulness of the bcr/abl gene rearrangement study in the diagnosis of a blast crisis initially located in lymph nodes of a patient with CML. The DNA analysis allows demonstration that the lymph node neoplastic cells originate from the clone responsible for the CML, while obtaining metaphases from a lymph node for the cytogenetic study gives rise to enormous difficulties and is practically impossible if the problem is studied retrospectively based on frozen or fixed samples.
For centuries in Europe, population movements have contributed to ethnic groups, cultures, and co... more For centuries in Europe, population movements have contributed to ethnic groups, cultures, and consequently, inheritance mixing. There are certain genetic diseases such as hereditary hemochromatosis whose distribution is directly related to the population movements. The objective of the present investigation was to determine the C282Y and H63D mutation frequency of the HFE gene in a cohort study of 1,000 neonates in the Community of Madrid (Spain), thus contributing to the HFE gene mutations distribution research in Europe and establishing the origin of the mutations in Spain. The allelic frequency of C282Y mutation was 1.7% (CI 95% 1.1–2.3) and the H63D allele was present in 16.4% of chromosomes (CI 95% 14.8–18). In Spain, the presence of C282Y mutation and its distribution could be due more to Celtic than to Viking legacy, whereas it is assumed that the one in relation to the H63D variant occurred in the Basque Country during the Paleolithic Period.
We have examined the phenotypic effects of 21 independent deletions from the fully sequenced and ... more We have examined the phenotypic effects of 21 independent deletions from the fully sequenced and annotated 356 kb telomeric region of the short arm of chromosome 16 (16p13.3). Fifteen genes contained within this region have been highly conserved throughout evolution and encode proteins involved in important housekeeping functions, synthesis of haemoglobin, signalling pathways and critical developmental pathways. Although a priori many of these genes would be considered candidates for critical haploinsufficient genes, none of the deletions within the 356 kb interval cause any discernible phenotype other than alpha thalassaemia whether inherited via the maternal or paternal line. These findings contrast with previous observations on patients with larger (> 1 Mb) deletions from the 16p telomere and therefore address the mechanisms by which monosomy gives rise to human genetic disease.
The t(9;22)(q34;q11) produces the BCR/ABL fusion gene which codifies a 210 kb protein with a stro... more The t(9;22)(q34;q11) produces the BCR/ABL fusion gene which codifies a 210 kb protein with a strong tyrosine kinase activity and is involved in cellular development and growth. Because this translocation is a reciprocal event, it could give rise to a second fusion gene, ABL-BCR, on the derivative 9q+. We analyzed the influence of the 3' M-BCR deletion on the clinical picture at diagnosis and disease outcome in 57 patients with a clinical diagnosis of CML. Molecular studies were done on DNA from peripheral blood leukocytes or bone marrow with the restrictions enzymes BglII, EcoRI, HindIII, and BamHI, and the BCR 3' probe (transprobe 1) (Oncogene Science Inc.), which encompasses almost all of the 5.8 Kb of the M-BCR gene area. In 18 patients Southern blot analysis showed deletion of the 3' end of BCR gene (32.7%). There were no significant differences between patients with or without deletion, either in the clinical and laboratory data at the disease diagnosis or at the disease outcome. The absence of differences between the patients with and without 3' BCR deletion supports the hypothesis that the hybrid gene ABL-BCR does not have an important role in leukemogenesis in CML cases.
This work compiles the results of our research on alpha- and beta-thalassemias, and includes a li... more This work compiles the results of our research on alpha- and beta-thalassemias, and includes a literature review of the molecular genetics of alpha- and beta-thalassemias in Spain. We studied 1,564 subjects with thalassemia (294 with beta-thalassemia and 1,264 with alpha-thalassemia) by molecular biology techniques. In relation to beta-thalassemia, a total of 15 different mutations were characterized in a study of 308 chromosomes belonging to 294 unrelated subjects. Eleven were homozygotes (22 alleles), three compound heterozygotes (6 alleles), and the remaining 280 were heterozygotes (280 alleles). A total of 86.6% of the alleles identified can be grouped into five different mutations [IVS-I-1 (G-->A), IVS-I-6 (T-->C), IVS-I-110 (G-->A), codon 39 (C-->T), codons 8/9 (+G)]. In 14 subjects (4.5%), all heterozygotes, it was not possible to identify the alteration responsible for the beta-thalassemia. For alpha-thalassemia, 911 subjects showed heterozygous alpha(+)-thalassemia (872 with -3.7 kb; 14 with -4.2 kb; two with the deletion of 3.5 kb of DNA, and 23 with nondeletional alpha-thalassemia). Two hundred and thirty-three subjects had homozygous alpha(+)-thalassemia (223 for -alpha(-3.7)/-alpha(-3.7)); one for -alpha(-4.2)/-alpha(-4.2); six for -alpha(-3.7)/-alpha(-4.2); one for -alpha(-3.5)/-alpha(-3.7); one for alphaalpha(Nco)/alphaalpha(Nco); one for alpha(HPh)/alpha(Hph)). One hundred patients presented with heterozygous alpha(0)-thalassemia (18 of whom were progenitors of patients with Hb H disease). The alpha(0) determinant was found in 20 patients with Hb H disease associated with -alpha(-3.7). From the DNA analysis were identified the - -(MED), - -(SEA), - -(SPAN) deletions and the - -(MA) mutations; in three cases, a break that affects the distal portion of the short arm of chromosome 16; one of these was associated with the ATR-16 (alpha-thal with mental retardation) syndrome. Triplication of the alpha genes (alphaalphaalpha(-3.7)/alphaalpha) was found in 25 subjects, 16 of whom were associated with a heterozygous beta-thalassemia. Only one patient was homozygous for the triplication of alpha genes (alphaalphaalpha(-3.7)/alphaalphaalpha(-3.7)) that was associated with a heterozygous beta-thalassemia. In the Mediterranean region preventive programs for thalassemia, based on the detection of heterozygote carriers and genetic advice, are not sufficient to reduce the incidence of newborns with major thalassemia. Prenatal diagnosis of thalassemias has given a new dimension to the prevention of these, but in order to implement this, a knowledge of the mutations and the incidence of these, is essential. This study, therefore, aims to give a general picture of the molecular genetics of thalassemia and its geographical distribution in our area.
Dominant inherited β-thalassemias describe those β-thalassemia variants that result in a thalasse... more Dominant inherited β-thalassemias describe those β-thalassemia variants that result in a thalassemia intermediate phenotype in individuals who have inherited only a single copy of the abnormal β gene. This form of thalassemia is characterized by moderately severe anemia with jaundice and splenomegaly; it is also characterized by the presence of inclusion bodies in the red blood cell precursors and has, therefore, previously been referred to as inclusion body β-thalassemia. We describe a case of inclusion body β-thalassemia in a 51-year-old Spanish male caused by a deletion of 11 bp (CD 131–134) in exon 3 of the β-globin gene. The deletion of 11 bp in exon 3 of the β-globin chain is predicted to produce an anomalous chain of 134 amino acids instead of the normal 146 with an extremely altered amino acid sequence from residues 131–134. Although this shortened variant would lead to a missing H helix, which is involved in α1β1 contact and α1β2 subunit interactions, the variant chain can still be bound to the heme group and acquire a secondary structure that is not suitable for the formation of stable dimers or tetramers and also less susceptible to proteolytic degradation. This is the first report of such a β-thalassemia mutation.
Se le llama fisicoquímica a la parte de la química que estudia las propiedades físicas y estructu... more Se le llama fisicoquímica a la parte de la química que estudia las propiedades físicas y estructuras de la materia, las leyes de la interacción química y las teorías que las gobiernan.
The clinical course of polycythemia vera is often complicated by thrombosis as well as by the pos... more The clinical course of polycythemia vera is often complicated by thrombosis as well as by the possible transition to myeloid metaplasia with myelofibrosis or acute myeloid leukemia. The aim of this study was to assess the rate of these complications in subjects receiving currently recommended treatments.
Proceedings of The National Academy of Sciences, 2006
RNA interference, mediated by small interfering RNAs (siRNAs), is a conserved regulatory process ... more RNA interference, mediated by small interfering RNAs (siRNAs), is a conserved regulatory process that has evolved as an antiviral defense mechanism in plants and animals. It is not known whether host cells also use siRNAs as an antibacterial defense mechanism in eukaryotes. Here, we report the discovery of an endogenous siRNA, nat-siRNAATGB2, that is specifically induced by the bacterial pathogen Pseudomonas syringae carrying effector avrRpt2. We demonstrate that the biogenesis of this siRNA requires DCL1, HYL1, HEN1, RDR6, NRPD1A, and SGS3. Its induction also depends on the cognate host disease resistance gene RPS2 and the NDR1 gene that is required for RPS2-specified resistance. This siRNA contributes to RPS2-mediated race-specific disease resistance by repressing PPRL, a putative negative regulator of the RPS2 resistance pathway.
... see Table 11), and hybridized with the following probes: a 1.8 kb SAC I 5 fragment from the r... more ... see Table 11), and hybridized with the following probes: a 1.8 kb SAC I 5 fragment from the recombi-nant PRB 5, a 1.5 kb Pst I a fragment for the recombinant PRB al, a ... Higgs, DR, Vickers, MA, Wilkie, AOM, Pretorius, IM., Jarman, AP, and Weatherall, DJ, Blood, 73:1081, 1989. ...
Summary. The introduction of molecular biological techniques in the study of chronic myeloid leuk... more Summary. The introduction of molecular biological techniques in the study of chronic myeloid leukaemia (CML) allows us to show the bcr/abl gene rearrangement produced by the translocation between the c-abl proto-oncogene located in chromosome 9 and the bcr region located in chromosome 22, which constitutes the molecular alteration of Philadelphia chromosome in CML. We present the usefulness of the bcr/abl gene rearrangement study in the diagnosis of a blast crisis initially located in lymph nodes of a patient with CML. The DNA analysis allows demonstration that the lymph node neoplastic cells originate from the clone responsible for the CML, while obtaining metaphases from a lymph node for the cytogenetic study gives rise to enormous difficulties and is practically impossible if the problem is studied retrospectively based on frozen or fixed samples.
For centuries in Europe, population movements have contributed to ethnic groups, cultures, and co... more For centuries in Europe, population movements have contributed to ethnic groups, cultures, and consequently, inheritance mixing. There are certain genetic diseases such as hereditary hemochromatosis whose distribution is directly related to the population movements. The objective of the present investigation was to determine the C282Y and H63D mutation frequency of the HFE gene in a cohort study of 1,000 neonates in the Community of Madrid (Spain), thus contributing to the HFE gene mutations distribution research in Europe and establishing the origin of the mutations in Spain. The allelic frequency of C282Y mutation was 1.7% (CI 95% 1.1–2.3) and the H63D allele was present in 16.4% of chromosomes (CI 95% 14.8–18). In Spain, the presence of C282Y mutation and its distribution could be due more to Celtic than to Viking legacy, whereas it is assumed that the one in relation to the H63D variant occurred in the Basque Country during the Paleolithic Period.
We have examined the phenotypic effects of 21 independent deletions from the fully sequenced and ... more We have examined the phenotypic effects of 21 independent deletions from the fully sequenced and annotated 356 kb telomeric region of the short arm of chromosome 16 (16p13.3). Fifteen genes contained within this region have been highly conserved throughout evolution and encode proteins involved in important housekeeping functions, synthesis of haemoglobin, signalling pathways and critical developmental pathways. Although a priori many of these genes would be considered candidates for critical haploinsufficient genes, none of the deletions within the 356 kb interval cause any discernible phenotype other than alpha thalassaemia whether inherited via the maternal or paternal line. These findings contrast with previous observations on patients with larger (> 1 Mb) deletions from the 16p telomere and therefore address the mechanisms by which monosomy gives rise to human genetic disease.
The t(9;22)(q34;q11) produces the BCR/ABL fusion gene which codifies a 210 kb protein with a stro... more The t(9;22)(q34;q11) produces the BCR/ABL fusion gene which codifies a 210 kb protein with a strong tyrosine kinase activity and is involved in cellular development and growth. Because this translocation is a reciprocal event, it could give rise to a second fusion gene, ABL-BCR, on the derivative 9q+. We analyzed the influence of the 3' M-BCR deletion on the clinical picture at diagnosis and disease outcome in 57 patients with a clinical diagnosis of CML. Molecular studies were done on DNA from peripheral blood leukocytes or bone marrow with the restrictions enzymes BglII, EcoRI, HindIII, and BamHI, and the BCR 3' probe (transprobe 1) (Oncogene Science Inc.), which encompasses almost all of the 5.8 Kb of the M-BCR gene area. In 18 patients Southern blot analysis showed deletion of the 3' end of BCR gene (32.7%). There were no significant differences between patients with or without deletion, either in the clinical and laboratory data at the disease diagnosis or at the disease outcome. The absence of differences between the patients with and without 3' BCR deletion supports the hypothesis that the hybrid gene ABL-BCR does not have an important role in leukemogenesis in CML cases.
This work compiles the results of our research on alpha- and beta-thalassemias, and includes a li... more This work compiles the results of our research on alpha- and beta-thalassemias, and includes a literature review of the molecular genetics of alpha- and beta-thalassemias in Spain. We studied 1,564 subjects with thalassemia (294 with beta-thalassemia and 1,264 with alpha-thalassemia) by molecular biology techniques. In relation to beta-thalassemia, a total of 15 different mutations were characterized in a study of 308 chromosomes belonging to 294 unrelated subjects. Eleven were homozygotes (22 alleles), three compound heterozygotes (6 alleles), and the remaining 280 were heterozygotes (280 alleles). A total of 86.6% of the alleles identified can be grouped into five different mutations [IVS-I-1 (G-->A), IVS-I-6 (T-->C), IVS-I-110 (G-->A), codon 39 (C-->T), codons 8/9 (+G)]. In 14 subjects (4.5%), all heterozygotes, it was not possible to identify the alteration responsible for the beta-thalassemia. For alpha-thalassemia, 911 subjects showed heterozygous alpha(+)-thalassemia (872 with -3.7 kb; 14 with -4.2 kb; two with the deletion of 3.5 kb of DNA, and 23 with nondeletional alpha-thalassemia). Two hundred and thirty-three subjects had homozygous alpha(+)-thalassemia (223 for -alpha(-3.7)/-alpha(-3.7)); one for -alpha(-4.2)/-alpha(-4.2); six for -alpha(-3.7)/-alpha(-4.2); one for -alpha(-3.5)/-alpha(-3.7); one for alphaalpha(Nco)/alphaalpha(Nco); one for alpha(HPh)/alpha(Hph)). One hundred patients presented with heterozygous alpha(0)-thalassemia (18 of whom were progenitors of patients with Hb H disease). The alpha(0) determinant was found in 20 patients with Hb H disease associated with -alpha(-3.7). From the DNA analysis were identified the - -(MED), - -(SEA), - -(SPAN) deletions and the - -(MA) mutations; in three cases, a break that affects the distal portion of the short arm of chromosome 16; one of these was associated with the ATR-16 (alpha-thal with mental retardation) syndrome. Triplication of the alpha genes (alphaalphaalpha(-3.7)/alphaalpha) was found in 25 subjects, 16 of whom were associated with a heterozygous beta-thalassemia. Only one patient was homozygous for the triplication of alpha genes (alphaalphaalpha(-3.7)/alphaalphaalpha(-3.7)) that was associated with a heterozygous beta-thalassemia. In the Mediterranean region preventive programs for thalassemia, based on the detection of heterozygote carriers and genetic advice, are not sufficient to reduce the incidence of newborns with major thalassemia. Prenatal diagnosis of thalassemias has given a new dimension to the prevention of these, but in order to implement this, a knowledge of the mutations and the incidence of these, is essential. This study, therefore, aims to give a general picture of the molecular genetics of thalassemia and its geographical distribution in our area.
Dominant inherited β-thalassemias describe those β-thalassemia variants that result in a thalasse... more Dominant inherited β-thalassemias describe those β-thalassemia variants that result in a thalassemia intermediate phenotype in individuals who have inherited only a single copy of the abnormal β gene. This form of thalassemia is characterized by moderately severe anemia with jaundice and splenomegaly; it is also characterized by the presence of inclusion bodies in the red blood cell precursors and has, therefore, previously been referred to as inclusion body β-thalassemia. We describe a case of inclusion body β-thalassemia in a 51-year-old Spanish male caused by a deletion of 11 bp (CD 131–134) in exon 3 of the β-globin gene. The deletion of 11 bp in exon 3 of the β-globin chain is predicted to produce an anomalous chain of 134 amino acids instead of the normal 146 with an extremely altered amino acid sequence from residues 131–134. Although this shortened variant would lead to a missing H helix, which is involved in α1β1 contact and α1β2 subunit interactions, the variant chain can still be bound to the heme group and acquire a secondary structure that is not suitable for the formation of stable dimers or tetramers and also less susceptible to proteolytic degradation. This is the first report of such a β-thalassemia mutation.
Se le llama fisicoquímica a la parte de la química que estudia las propiedades físicas y estructu... more Se le llama fisicoquímica a la parte de la química que estudia las propiedades físicas y estructuras de la materia, las leyes de la interacción química y las teorías que las gobiernan.
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