Carmen Marquez - Academia.edu (original) (raw)

Papers by Carmen Marquez

Research paper thumbnail of First Pre-Clinical and Clinical Validation of an Automated Sperm Injection Robot (Icsi-A) in Human Oocytes

Research paper thumbnail of Los curanderos y santeros del Alto Rïo Negro com exponentes de un sincretismo cultural amazónico

Los fenómenos sociales que analizaremos en las páginas siguientes se encuentranlocalizadosprincip... more Los fenómenos sociales que analizaremos en las páginas siguientes se encuentranlocalizadosprincipalmente en las márgenesde los ríos Negro, Guainíay bajo Casiquiare.A estosefectos, consideramos como Alto Río Negro a la zona que se extiende desde San Gabriel da Cachoeira (unos setenta kilómetros más abajo de la boca del río Vaupeis) hasta el alto Guainía y de la cual excluimos el alto Casiquiare, río arriba de la boca del afluente Basiba, por encontrarse deshabitado desde hace unos veinte años y por pertenecer con más derecho a las culturas orinoquenses Dearwa (también llamada Piaroa) Ye’kwana (o Maquiritare) e incluso Yanomami (o Guaica). La zona así delimitada pertenece a la cuenca amazónica y se halla cubierta por bosque tropical lluvioso con bosque bajo y por sabanas inundables (rebalses, en el habla local) en la divisoria con la cuenca dcl Orinoco que señalanlos ríos Tcmi y Atabapo.No obstante,algunos de los elementoslúdicos y religiosos que hoy nos ocupan también se observan en ...

Research paper thumbnail of Exorcismo contra una epidemia de sarampión que azota al Alto Río Negro

Research paper thumbnail of Spectral karyotyping of fresh, non-inseminated oocytes

Molecular Human Reproduction, 2002

The object of this study was to determine the mechanisms producing aneuploidy in female meiosis I... more The object of this study was to determine the mechanisms producing aneuploidy in female meiosis I by analysing the whole chromosome complement of human non-inseminated and unfertilized fresh oocytes. For this purpose, 131 fresh oocytes were obtained from 16 oocyte donors (24-48 years old). These oocytes were fixed immediately after retrieval and 47 good quality metaphases from 13 donors were analysed by spectral karyotyping to identify all 23 chromosome types. The data was divided into two maternal age groups, 24-34 (n ⍧ 31) and ≥35 years (n ⍧ 16). More non-disjunction (13 and 25%), unbalanced predivision (10 and 44%, P < 0.01) and balanced predivision (6 and 62%, P < 0.001) events were found in the older group of oocytes. There was an increase in balanced predivision with decreasing chromosome size (P < 0.001). The present results are the first obtained in fresh oocytes where all chromosomes were specifically identified, and support previous theories that predivision of chromatids is a major factor causing aneuploidy. Previous reports with inseminated, non-fertilized oocytes fixed ≥24 h after retrieval suffered from artefactual predivision of chromatids triggered by in-vitro ageing of oocytes.

Research paper thumbnail of Positive outcome after preimplantation diagnosis of aneuploidy in human embryos *

Human Reproduction, 1999

Chromosomal abnormalities are responsible for a great deal of embryo wastage, which is reflected,... more Chromosomal abnormalities are responsible for a great deal of embryo wastage, which is reflected, at least partially, in decreased implantation and increased miscarriage in older women. To address this problem the transfer of only chromosomally normal embryos previously selected by preimplantation genetic diagnosis (PGD) has been proposed. We designed a multi-centre in-vitro fertilization (IVF) study to compare controls and a test group that underwent embryo biopsy and PGD for aneuploidy. Patients were matched retrospectively, but blindly, for average maternal age, number of previous IVF cycles, duration of stimulation, oestradiol concentrations on day ⍣1, and average mature follicles. All these parameters were similar in test and control groups. Only embryos classified as normal for those chromosomes were transferred after PGD. The results showed that the rates of fetal heart beat (FHB)/embryo transferred between the control and test groups were similar. However, spontaneous abortions, measured as FHB aborted/FHB detected, decreased after PGD (P < 0.05), and ongoing pregnancies and delivered babies increased (P < 0.05) in the PGD group of patients. Two conclusions were obtained: (i) PGD of aneuploidy reduced embryo loss after implantation; (ii) implantation rates were not significantly improved, but the proportion of ongoing and delivered babies was increased.

Research paper thumbnail of Rapid visualization of metaphase chromosomes in single human blastomeres after fusion with in-vitro matured bovine eggs

Human Reproduction, 1999

The present study was aimed to facilitate karyotyping of human blastomeres using the metaphase-in... more The present study was aimed to facilitate karyotyping of human blastomeres using the metaphase-inducing factors present in unfertilized eggs. A rapid technique for karyotyping would have wide application in the field of preimplantation genetic diagnosis. When cryopreserved invitro matured bovine oocytes were fused with human blastomeres, the transferred human nuclei were forced into metaphase within a few hours. Eighty-seven human blastomeres from abnormal or arrested embryos were fused with bovine oocytes in a preclinical study. Fusion efficiency was 100%. In 21 of the hybrid cells, no trace of human chromatin was found. Of the remaining 66, 64 (97%) yielded chromosomes suitable for analysis. The method was used to karyotype embryos from two patients with maternal translocations. One embryo which was judged to be karyotypically normal was replaced in the first patient, resulting in one pregnancy with a normal fetus. None of the second patient's embryos was diagnosed as normal, and hence none was transferred. The results of the present study demonstrated that the ooplasmic factors which induce and maintain metaphase in bovine oocytes can force transferred human blastomere nuclei into premature metaphase, providing the basis for a rapid method of karyotyping blastomeres from preimplantation embryos and, by implication, cells from other sources.

Research paper thumbnail of 1208 Adherence to combination therapy increases sustained response in patients with chronic hepatitis C

Hepatology, 2003

AASLD ABSTRACTS 741A for 36 weeks. Ribavirin 1000 or 1200 mg/day was coadministered throughout th... more AASLD ABSTRACTS 741A for 36 weeks. Ribavirin 1000 or 1200 mg/day was coadministered throughout the 48-week treatment period. Patients who failed to achieve an on-treatment virological response, defined as undetectable HCV RNA levels (<50 IU/mL, COBAS AMPLICOR ® HCV Test, v2.0 [Roche Diagnostics]) after 12 weeks, discontinued treatment. Results Seventy-five patients were randomized to treatment. Three patients did not receive study medication, thus 72 patients were included in the analysis (Table). The rates of virological response after 12 weeks of treatment with peginterferon alfa-2a (40KD) increased in a dose-dependent manner: 21.4% in the 180/~g/week group, 35% in the 270 /~g/week group, and 45.8% in the 360 /~g/week group. Overall, the response rates were higher in patients with low baseline viral loads (-<800,000 IU/mL). The incidence of adverse events, severe adverse events, and laboratory abnormalities including neutropenia and thrombocytopenia were similar among the three treatment groups. Asthenia (40.3%), headache (34.7%), fever (31.9%), and myalgia (27.8%) were the most frequently reported adverse events overall. Reductions in the dosage of peginterferon alfa-2a (40KD) because of adverse events occurred in 9, 2 and 3 patients in the 180, 270 and 360/~g/week groups, respectively. At week 12, grade 3 neutropenia was detected in 8 (29.6%), 5 (27.8%) and 3 (13%) patients treated with peginterferon alfa-2a (40KD) 180, 270 or 360/~g/week. No patients in any group had grade 4 neutropenia, or grade 3 or 4 thrombocytopenia after 12 weeks. Conclusions In patients infected with HCV genotype I who have failed to respond to previous treatment with IFN/ribavirin, peginterferon alfa-2a (40KD) (PEGASYS ®) and ribavirin (COPEGUS ®) can suppress HCV RNA levels below the limit of detection. The highest rate of virological response at week 12 was obtained in patients treated with peginterferon alfa-2a (40KD) 360/~g/week. Peginterferon alfa-2a (40KD) was equally well-tolerated at doses of 180 to 360/~g/week. Baseline Characteristics and Virological Response at Week 12

Research paper thumbnail of 583 Long-term follow-up of chronic hepatitis C patients non-responders to antiviral treatment

Hepatology, 2003

Background: Fibrotest-Actitest (FF-AT) are non-invasive biochemical markers of fibrosis and activ... more Background: Fibrotest-Actitest (FF-AT) are non-invasive biochemical markers of fibrosis and activity used as alternatives to liver biopsy in CHC. Biopsy has a high sampling error (33% for fibrosis and 24% for activity) and intra-and inter-pathologist variability greater than 10%. FF-AT components can be modified by hemolysis, sepsis or Gilbert's disease. Therefore discordances between biopsy and FF-AT results can be either due to FF-AT or to biopsy. Aim: to prospectively assess the causes of the high discordance (H'D) of at least 2 stages or 2 grades METAVIR between FF-AT and biopsy. Methods: The histological fibrosis stage and activity grade were pro-spec~vely assessed on the same day by an intercostal liver biopsy or by FF-AT. Several risk factors of failure were considered at baseline and during follow-up. For biopsy failure these were biopsy size <15mm, more than one fragment, and <5 portal tracts. Good quality biopsies were never been dassified as failure except only in opposite clinical and biological evidence (drrhosis or acute flare up). For FF-AT failure these were hemolysis, acute inflammation, and Gilbert's disease. Independent endpoints used for assessing drrhosis were a platelet count <150,000, obvious drrhosis on ultrasound, gradient portal pressure >5 mmHg, and grade 2 or 3 esophageal varices. Biopsy failure was defined as being certain if 1) FF-AT predicted drrhosis in the presence of at least 2 signs of cirrhosis; or 2) if there were signs of acute flare up of hepatitis

Research paper thumbnail of Preimplantation Diagnosis: An Alternative to Prenatal Diagnosis of Genetic and Chromosomal Disorders

Journal of Assisted Reproduction and Genetics, 1999

Research paper thumbnail of Spectral Karyotyping of Unfertilized and Noninseminated Oocytes

Fertility and Sterility, 2000

genes, Band 11, has been further analyzed. This gene shows no significant homology to any known g... more genes, Band 11, has been further analyzed. This gene shows no significant homology to any known gene. Full length cDNA clones have been sequenced and show an open reading frame coding for an 112 amino acid protein. In the mouse M1 myelo-monocytic cell line, LIF has been shown to down regulate the mRNA expression of Band 11, by two fold. Northern blot analysis of Band 11 in the uteri of pseudopregnant, wild type mice shows a small decrease between day 4 and 4.5 of pseudopregnancy, followed by a significant increase on day 5. In-vivo studies of LIF regulation and protein tagging are underway. Conclusions: We have identified a number of genes in the mouse uterus that are potentially regulated by LIF in-vivo. These genes may allow us further insights into the molecular pathway by which LIF controls the initial attachment of the embryo to the uterine epithelium. Understanding this pathway may greatly extend the therapeutic options open to patients with infertility.

Research paper thumbnail of Chromosome Abnormalities in Embryos Obtained After Conventional In Vitro Fertilization and Intracytoplasmic Sperm Injection

Fertility and Sterility, 1998

To compare the rate of numerical chromosome abnormalities in embryos derived from bipronucleated ... more To compare the rate of numerical chromosome abnormalities in embryos derived from bipronucleated zygotes produced by intracytoplasmic sperm injection (ICSI) and conventional IVF. Design: Embryos were classified by maternal age and morphological and developmental characteristics to avoid bias when comparing chromosome abnormalities in ICSI and IVF embryos.

Research paper thumbnail of First Pre-Clinical and Clinical Validation of an Automated Sperm Injection Robot (Icsi-A) in Human Oocytes

Research paper thumbnail of Los curanderos y santeros del Alto Rïo Negro com exponentes de un sincretismo cultural amazónico

Los fenómenos sociales que analizaremos en las páginas siguientes se encuentranlocalizadosprincip... more Los fenómenos sociales que analizaremos en las páginas siguientes se encuentranlocalizadosprincipalmente en las márgenesde los ríos Negro, Guainíay bajo Casiquiare.A estosefectos, consideramos como Alto Río Negro a la zona que se extiende desde San Gabriel da Cachoeira (unos setenta kilómetros más abajo de la boca del río Vaupeis) hasta el alto Guainía y de la cual excluimos el alto Casiquiare, río arriba de la boca del afluente Basiba, por encontrarse deshabitado desde hace unos veinte años y por pertenecer con más derecho a las culturas orinoquenses Dearwa (también llamada Piaroa) Ye’kwana (o Maquiritare) e incluso Yanomami (o Guaica). La zona así delimitada pertenece a la cuenca amazónica y se halla cubierta por bosque tropical lluvioso con bosque bajo y por sabanas inundables (rebalses, en el habla local) en la divisoria con la cuenca dcl Orinoco que señalanlos ríos Tcmi y Atabapo.No obstante,algunos de los elementoslúdicos y religiosos que hoy nos ocupan también se observan en ...

Research paper thumbnail of Exorcismo contra una epidemia de sarampión que azota al Alto Río Negro

Research paper thumbnail of Spectral karyotyping of fresh, non-inseminated oocytes

Molecular Human Reproduction, 2002

The object of this study was to determine the mechanisms producing aneuploidy in female meiosis I... more The object of this study was to determine the mechanisms producing aneuploidy in female meiosis I by analysing the whole chromosome complement of human non-inseminated and unfertilized fresh oocytes. For this purpose, 131 fresh oocytes were obtained from 16 oocyte donors (24-48 years old). These oocytes were fixed immediately after retrieval and 47 good quality metaphases from 13 donors were analysed by spectral karyotyping to identify all 23 chromosome types. The data was divided into two maternal age groups, 24-34 (n ⍧ 31) and ≥35 years (n ⍧ 16). More non-disjunction (13 and 25%), unbalanced predivision (10 and 44%, P < 0.01) and balanced predivision (6 and 62%, P < 0.001) events were found in the older group of oocytes. There was an increase in balanced predivision with decreasing chromosome size (P < 0.001). The present results are the first obtained in fresh oocytes where all chromosomes were specifically identified, and support previous theories that predivision of chromatids is a major factor causing aneuploidy. Previous reports with inseminated, non-fertilized oocytes fixed ≥24 h after retrieval suffered from artefactual predivision of chromatids triggered by in-vitro ageing of oocytes.

Research paper thumbnail of Positive outcome after preimplantation diagnosis of aneuploidy in human embryos *

Human Reproduction, 1999

Chromosomal abnormalities are responsible for a great deal of embryo wastage, which is reflected,... more Chromosomal abnormalities are responsible for a great deal of embryo wastage, which is reflected, at least partially, in decreased implantation and increased miscarriage in older women. To address this problem the transfer of only chromosomally normal embryos previously selected by preimplantation genetic diagnosis (PGD) has been proposed. We designed a multi-centre in-vitro fertilization (IVF) study to compare controls and a test group that underwent embryo biopsy and PGD for aneuploidy. Patients were matched retrospectively, but blindly, for average maternal age, number of previous IVF cycles, duration of stimulation, oestradiol concentrations on day ⍣1, and average mature follicles. All these parameters were similar in test and control groups. Only embryos classified as normal for those chromosomes were transferred after PGD. The results showed that the rates of fetal heart beat (FHB)/embryo transferred between the control and test groups were similar. However, spontaneous abortions, measured as FHB aborted/FHB detected, decreased after PGD (P < 0.05), and ongoing pregnancies and delivered babies increased (P < 0.05) in the PGD group of patients. Two conclusions were obtained: (i) PGD of aneuploidy reduced embryo loss after implantation; (ii) implantation rates were not significantly improved, but the proportion of ongoing and delivered babies was increased.

Research paper thumbnail of Rapid visualization of metaphase chromosomes in single human blastomeres after fusion with in-vitro matured bovine eggs

Human Reproduction, 1999

The present study was aimed to facilitate karyotyping of human blastomeres using the metaphase-in... more The present study was aimed to facilitate karyotyping of human blastomeres using the metaphase-inducing factors present in unfertilized eggs. A rapid technique for karyotyping would have wide application in the field of preimplantation genetic diagnosis. When cryopreserved invitro matured bovine oocytes were fused with human blastomeres, the transferred human nuclei were forced into metaphase within a few hours. Eighty-seven human blastomeres from abnormal or arrested embryos were fused with bovine oocytes in a preclinical study. Fusion efficiency was 100%. In 21 of the hybrid cells, no trace of human chromatin was found. Of the remaining 66, 64 (97%) yielded chromosomes suitable for analysis. The method was used to karyotype embryos from two patients with maternal translocations. One embryo which was judged to be karyotypically normal was replaced in the first patient, resulting in one pregnancy with a normal fetus. None of the second patient's embryos was diagnosed as normal, and hence none was transferred. The results of the present study demonstrated that the ooplasmic factors which induce and maintain metaphase in bovine oocytes can force transferred human blastomere nuclei into premature metaphase, providing the basis for a rapid method of karyotyping blastomeres from preimplantation embryos and, by implication, cells from other sources.

Research paper thumbnail of 1208 Adherence to combination therapy increases sustained response in patients with chronic hepatitis C

Hepatology, 2003

AASLD ABSTRACTS 741A for 36 weeks. Ribavirin 1000 or 1200 mg/day was coadministered throughout th... more AASLD ABSTRACTS 741A for 36 weeks. Ribavirin 1000 or 1200 mg/day was coadministered throughout the 48-week treatment period. Patients who failed to achieve an on-treatment virological response, defined as undetectable HCV RNA levels (<50 IU/mL, COBAS AMPLICOR ® HCV Test, v2.0 [Roche Diagnostics]) after 12 weeks, discontinued treatment. Results Seventy-five patients were randomized to treatment. Three patients did not receive study medication, thus 72 patients were included in the analysis (Table). The rates of virological response after 12 weeks of treatment with peginterferon alfa-2a (40KD) increased in a dose-dependent manner: 21.4% in the 180/~g/week group, 35% in the 270 /~g/week group, and 45.8% in the 360 /~g/week group. Overall, the response rates were higher in patients with low baseline viral loads (-<800,000 IU/mL). The incidence of adverse events, severe adverse events, and laboratory abnormalities including neutropenia and thrombocytopenia were similar among the three treatment groups. Asthenia (40.3%), headache (34.7%), fever (31.9%), and myalgia (27.8%) were the most frequently reported adverse events overall. Reductions in the dosage of peginterferon alfa-2a (40KD) because of adverse events occurred in 9, 2 and 3 patients in the 180, 270 and 360/~g/week groups, respectively. At week 12, grade 3 neutropenia was detected in 8 (29.6%), 5 (27.8%) and 3 (13%) patients treated with peginterferon alfa-2a (40KD) 180, 270 or 360/~g/week. No patients in any group had grade 4 neutropenia, or grade 3 or 4 thrombocytopenia after 12 weeks. Conclusions In patients infected with HCV genotype I who have failed to respond to previous treatment with IFN/ribavirin, peginterferon alfa-2a (40KD) (PEGASYS ®) and ribavirin (COPEGUS ®) can suppress HCV RNA levels below the limit of detection. The highest rate of virological response at week 12 was obtained in patients treated with peginterferon alfa-2a (40KD) 360/~g/week. Peginterferon alfa-2a (40KD) was equally well-tolerated at doses of 180 to 360/~g/week. Baseline Characteristics and Virological Response at Week 12

Research paper thumbnail of 583 Long-term follow-up of chronic hepatitis C patients non-responders to antiviral treatment

Hepatology, 2003

Background: Fibrotest-Actitest (FF-AT) are non-invasive biochemical markers of fibrosis and activ... more Background: Fibrotest-Actitest (FF-AT) are non-invasive biochemical markers of fibrosis and activity used as alternatives to liver biopsy in CHC. Biopsy has a high sampling error (33% for fibrosis and 24% for activity) and intra-and inter-pathologist variability greater than 10%. FF-AT components can be modified by hemolysis, sepsis or Gilbert's disease. Therefore discordances between biopsy and FF-AT results can be either due to FF-AT or to biopsy. Aim: to prospectively assess the causes of the high discordance (H'D) of at least 2 stages or 2 grades METAVIR between FF-AT and biopsy. Methods: The histological fibrosis stage and activity grade were pro-spec~vely assessed on the same day by an intercostal liver biopsy or by FF-AT. Several risk factors of failure were considered at baseline and during follow-up. For biopsy failure these were biopsy size <15mm, more than one fragment, and <5 portal tracts. Good quality biopsies were never been dassified as failure except only in opposite clinical and biological evidence (drrhosis or acute flare up). For FF-AT failure these were hemolysis, acute inflammation, and Gilbert's disease. Independent endpoints used for assessing drrhosis were a platelet count <150,000, obvious drrhosis on ultrasound, gradient portal pressure >5 mmHg, and grade 2 or 3 esophageal varices. Biopsy failure was defined as being certain if 1) FF-AT predicted drrhosis in the presence of at least 2 signs of cirrhosis; or 2) if there were signs of acute flare up of hepatitis

Research paper thumbnail of Preimplantation Diagnosis: An Alternative to Prenatal Diagnosis of Genetic and Chromosomal Disorders

Journal of Assisted Reproduction and Genetics, 1999

Research paper thumbnail of Spectral Karyotyping of Unfertilized and Noninseminated Oocytes

Fertility and Sterility, 2000

genes, Band 11, has been further analyzed. This gene shows no significant homology to any known g... more genes, Band 11, has been further analyzed. This gene shows no significant homology to any known gene. Full length cDNA clones have been sequenced and show an open reading frame coding for an 112 amino acid protein. In the mouse M1 myelo-monocytic cell line, LIF has been shown to down regulate the mRNA expression of Band 11, by two fold. Northern blot analysis of Band 11 in the uteri of pseudopregnant, wild type mice shows a small decrease between day 4 and 4.5 of pseudopregnancy, followed by a significant increase on day 5. In-vivo studies of LIF regulation and protein tagging are underway. Conclusions: We have identified a number of genes in the mouse uterus that are potentially regulated by LIF in-vivo. These genes may allow us further insights into the molecular pathway by which LIF controls the initial attachment of the embryo to the uterine epithelium. Understanding this pathway may greatly extend the therapeutic options open to patients with infertility.

Research paper thumbnail of Chromosome Abnormalities in Embryos Obtained After Conventional In Vitro Fertilization and Intracytoplasmic Sperm Injection

Fertility and Sterility, 1998

To compare the rate of numerical chromosome abnormalities in embryos derived from bipronucleated ... more To compare the rate of numerical chromosome abnormalities in embryos derived from bipronucleated zygotes produced by intracytoplasmic sperm injection (ICSI) and conventional IVF. Design: Embryos were classified by maternal age and morphological and developmental characteristics to avoid bias when comparing chromosome abnormalities in ICSI and IVF embryos.