Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 12 de 12
Filtrar
1.
Reprod Biomed Online ; 36(2): 130-136, 2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-29269265

RESUMEN

Shared motherhood IVF treatment is becoming increasingly accepted among assisted reproductive techique practitioners and patients in Europe, although data on its overall efficiency remain scarce. This 6-year retrospective study from a single, private, UK HFEA-regulated centre included consecutive lesbian couples (n = 121) undergoing shared motherhood IVF treatment (141 cycles). Recipients were more parous and had undergone more previous intrauterine insemination and IVF treatments than donor partners, who had slightly higher ovarian reserve markers than recipients. Indications in most cycles (60%) were non-medical. Most (79%) egg-providers were stimulated with gonadotrophin releasing hormone antagonist protocol, and no moderate or severe cases of ovarian hyperstimulation syndrome (OHSS) arose. A total of 172 fresh and vitrified-warmed embryo transfers were carried out: 70% at the blastocyst-stage and 58% involved a single embryo. Cumulative live birth rate per receiver was 60% (72/120), and twin delivery rate was 14% (10/72). Perinatal outcome parameters were better for singleton than twin pregnancies, although the latter also achieved generally favourable outcomes. No significant difference in cumulative outcomes were found between synchronized and non-synchronized cycles. Shared motherhood IVF combines ovarian stimulation with single blastocyst transfer to provide a safe and effective treatment modality offering reassuring obstetrical and perinatal outcomes.


Asunto(s)
Tasa de Natalidad , Fertilización In Vitro , Donación de Oocito , Minorías Sexuales y de Género , Adulto , Femenino , Humanos , Persona de Mediana Edad , Inducción de la Ovulación , Embarazo , Estudios Retrospectivos , Adulto Joven
2.
BJS Open ; 5(1)2021 01 08.
Artículo en Inglés | MEDLINE | ID: mdl-33609379

RESUMEN

BACKGROUND: Phlegmonous and gangrenous appendicitis represent independent pathophysiological entities with different clinical courses ranging from spontaneous resolution to septic disease. However, reliable predictive methods for these clinical phenotypes have not yet been established. In an attempt to provide pathophysiological insights into the matter, a genomewide gene expression analysis was undertaken in patients with acute appendicitis. METHODS: Peripheral blood mononuclear cells were isolated and, after histological confirmation of PA or GA, analysed for genomewide gene expression profiling using RNA microarray technology and subsequent pathway analysis. RESULTS: Samples from 29 patients aged 7-17 years were included. Genomewide gene expression analysis was performed on 13 samples of phlegmonous and 16 of gangrenous appendicitis. From a total of 56 666 genes, 3594 were significantly differently expressed. Distinct interaction between T and B cells in the phlegmonous appendicitis group was suggested by overexpression of T cell receptor α and ß subunits, CD2, CD3, MHC II, CD40L, and the B cell markers CD72 and CD79, indicating an antiviral mechanism. In the gangrenous appendicitis group, expression of genes delineating antibacterial mechanisms was found. CONCLUSION: These results provide evidence for different and independent gene expression in phlegmonous and gangrenous appendicitis in general, but also suggest distinct immunological patterns for the respective entities. In particular, the findings are compatible with previous evidence of spontaneous resolution in phlegmonous and progressive disease in gangrenous appendicitis.


Asunto(s)
Apendicitis/clasificación , Apendicitis/genética , Leucocitos Mononucleares/patología , Enfermedad Aguda , Adolescente , Niño , Femenino , Gangrena , Perfilación de la Expresión Génica , Humanos , Masculino , Análisis por Micromatrices , Estudios Prospectivos
3.
Leukemia ; 19(7): 1198-206, 2005 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-15902298

RESUMEN

Overexpression of BCR-ABL and P-glycoprotein (Pgp) are two of the known mechanisms of imatinib resistance. As combination therapy may allow to overcome drug resistance, we investigated the effect of combination treatment with imatinib and 17-allylamino-17-demethoxygeldanamycin (17-AAG), a heat-shock protein 90 (Hsp90) inhibitor, on different imatinib-sensitive and imatinib-resistant CML cell lines. In imatinib-sensitive cells, combination index (CI) values obtained using the method of Chou and Talalay indicated additive (CI=1) or marginally antagonistic (CI>1) effects following simultaneous treatment with imatinib and 17-AAG. In imatinib-resistant cells both drugs acted synergistically (CI<1). In primary chronic-phase CML cells additive or synergistic effects of the combination of imatinib plus 17-AAG were discernible. Annexin V/propidium iodide staining showed that the activity of imatinib plus 17-AAG is mediated by apoptosis. Combination treatment with imatinib plus 17-AAG was more effective in reducing the BCR-ABL protein level than 17-AAG alone. Monotherapy with 17-AAG decreased P-glycoprotein activity, which may increase intracellular imatinib levels and contribute to the sensitization of CML cells to imatinib. The results suggest that combination of imatinib and 17-AAG may be useful to overcome imatinib resistance in a clinical setting.


Asunto(s)
Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/efectos de los fármacos , Protocolos de Quimioterapia Combinada Antineoplásica/farmacología , Proteínas de Fusión bcr-abl/biosíntesis , Leucemia Mielógena Crónica BCR-ABL Positiva/tratamiento farmacológico , Piperazinas/farmacología , Proteínas Tirosina Quinasas/biosíntesis , Pirimidinas/farmacología , Rifabutina/análogos & derivados , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/fisiología , Apoptosis/efectos de los fármacos , Benzamidas , Benzoquinonas , Proliferación Celular/efectos de los fármacos , Sinergismo Farmacológico , Proteínas de Fusión bcr-abl/genética , Regulación Leucémica de la Expresión Génica/efectos de los fármacos , Humanos , Mesilato de Imatinib , Hibridación Fluorescente in Situ , Lactamas Macrocíclicas , Leucemia Mielógena Crónica BCR-ABL Positiva/genética , Leucemia Mielógena Crónica BCR-ABL Positiva/patología , Fosforilación , Proteínas Tirosina Quinasas/análisis , ARN Mensajero/genética , Rifabutina/farmacología , Ensayo de Tumor de Célula Madre
4.
Cancer Res ; 59(14): 3404-10, 1999 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-10416602

RESUMEN

We used the human myelomonoblastic leukemia cell line PLB-985 to study the effects of temperatures ranging from 37 degrees C to 43 degrees C for 1 h on the induction of apoptosis and cell cycle distribution in leukemia cells. The threshold temperature for the onset of apoptosis was 42 degrees C. Whereas hyperthermia exerted no effect on the expression of Bcl-2 and Bax, heat induced a >30-fold increase of tumor necrosis factor (TNF) alpha mRNA expression and a significant increase in TNF-alpha protein secretion. This endogenous production of TNF-alpha correlated directly with the temperature-induced apoptode effect. Blocking TNF-alpha expression via treatment with pyrrolidinedithiocarbamate or blocking TNF-alpha activity with neutralizing antibodies abrogated heat-provoked apoptosis. In addition, exposure of cell culture supernatant of heat-treated PLB-985 cells to untreated cells induced an apoptotic effect. These data indicate a TNF-a-mediated self eradication of the leukemia cells after heat exposure. Inducing apoptosis with wild-type TNF-alpha or p55 and p75 protein muteins demonstrated that this effect was mediated by the p55 receptor. Interestingly, the autocrine suicidal loop found in immature leukemia cells was lost after granulocytic differentiation with 0.5% N,N-dimethylformamide. These data should be of critical importance for the understanding of the biological impact of fever as well as for developing therapeutic approaches to malignant diseases


Asunto(s)
Apoptosis/fisiología , Fiebre/fisiopatología , Calor , Leucemia Mielomonocítica Aguda/patología , Proteínas de Neoplasias/fisiología , Factor de Necrosis Tumoral alfa/fisiología , Anticuerpos Monoclonales/farmacología , Antígenos CD/fisiología , Ciclo Celular/efectos de los fármacos , Diferenciación Celular/efectos de los fármacos , Dimetilformamida/farmacología , Regulación Leucémica de la Expresión Génica/efectos de los fármacos , Genes bcl-2 , Humanos , Hipertermia Inducida , Leucemia Mielomonocítica Aguda/genética , Leucemia Mielomonocítica Aguda/metabolismo , Proteínas de Neoplasias/biosíntesis , Proteínas de Neoplasias/genética , Proteínas Proto-Oncogénicas/biosíntesis , Proteínas Proto-Oncogénicas c-bcl-2/biosíntesis , Pirrolidinas/farmacología , ARN Mensajero/biosíntesis , ARN Neoplásico/biosíntesis , Receptores del Factor de Necrosis Tumoral/fisiología , Receptores Tipo I de Factores de Necrosis Tumoral , Proteínas Recombinantes/farmacología , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Tiocarbamatos/farmacología , Células Tumorales Cultivadas/efectos de los fármacos , Células Tumorales Cultivadas/metabolismo , Células Tumorales Cultivadas/patología , Factor de Necrosis Tumoral alfa/biosíntesis , Factor de Necrosis Tumoral alfa/genética , Factor de Necrosis Tumoral alfa/farmacología , Proteína X Asociada a bcl-2
5.
J Leukoc Biol ; 73(5): 600-3, 2003 May.
Artículo en Inglés | MEDLINE | ID: mdl-12714574

RESUMEN

Chronic myelogenous leukemia (CML) is characterized by aberrant trafficking of malignant hematopoietic progenitor cells in the peripheral blood. Expression of the cell adhesion molecule CD62L was reported to be significantly lower in CML patients than in normal controls. We studied whether the transcription of CD62L in CML cells is dependent on the activity of the BCR-ABL tyrosine kinase. Following addition of the Abelson (ABL) tyrosine kinase inhibitor imatinib (formerly STI571) to two BCR-ABL-positive cell lines (BV173, SD-1), we observed a dose-dependent increase in CD62L RNA levels of up to 45-fold by a quantitative, real-time polymerase chain reaction and an increase in the amount of cell surface-bound CD62L of up to 18-fold by quantitative flow cytometry, respectively. These data are validated by an increased CD62L expression in the bone marrow of patients (n=6) with advanced CML who received imatinib. Restoration of defective cell adhesion mediated via the CD62L pathway may be one mechanism of action of imatinib in BCR-ABL-positive leukemias.


Asunto(s)
Antineoplásicos/farmacología , Biomarcadores de Tumor/análisis , Inhibidores Enzimáticos/farmacología , Proteínas de Fusión bcr-abl/análisis , Regulación Leucémica de la Expresión Génica/efectos de los fármacos , Selectina L/biosíntesis , Leucemia Mielógena Crónica BCR-ABL Positiva/patología , Proteínas de Neoplasias/biosíntesis , Piperazinas/farmacología , Pirimidinas/farmacología , Benzamidas , Relación Dosis-Respuesta a Droga , Humanos , Mesilato de Imatinib , Selectina L/genética , Leucemia Mielógena Crónica BCR-ABL Positiva/metabolismo , Proteínas de Neoplasias/genética , Reacción en Cadena de la Polimerasa , ARN Mensajero/biosíntesis , ARN Neoplásico/biosíntesis , Células Tumorales Cultivadas/efectos de los fármacos
6.
Artículo en Inglés | MEDLINE | ID: mdl-26172649

RESUMEN

When DNA molecules are heated they denature. This occurs locally so that loops of molten single DNA strands form, connected by intact double-stranded DNA pieces. The properties of this "melting" transition have been intensively investigated. Recently there has been a surge of interest in this question, in part caused by experiments determining the properties of partially bound DNA confined to nanochannels. But how does such confinement affect the melting transition? To answer this question we introduce and solve a model predicting how confinement affects the melting transition for a simple model system by first disregarding the effect of self-avoidance. We find that the transition is smoother for narrower channels. By means of Monte Carlo simulations we then show that a model incorporating self-avoidance shows qualitatively the same behavior and that the effect of confinement is stronger than in the ideal case.


Asunto(s)
ADN/química , Modelos Moleculares , Transición de Fase , Conformación de Ácido Nucleico , Desnaturalización de Ácido Nucleico
7.
Biomicrofluidics ; 9(4): 044114, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-26392826

RESUMEN

The contiguity and phase of sequence information are intrinsic to obtain complete understanding of the genome and its relationship to phenotype. We report the fabrication and application of a novel nanochannel design that folds megabase lengths of genomic DNA into a systematic back-and-forth meandering path. Such meandering nanochannels enabled us to visualize the complete 5.7 Mbp (1 mm) stained DNA length of a Schizosaccharomyces pombe chromosome in a single frame of a CCD. We were able to hold the DNA in situ while implementing partial denaturation to obtain a barcode pattern that we could match to a reference map using the Poland-Scheraga model for DNA melting. The facility to compose such long linear lengths of genomic DNA in one field of view enabled us to directly visualize a repeat motif, count the repeat unit number, and chart its location in the genome by reference to unique barcode motifs found at measurable distances from the repeat. Meandering nanochannel dimensions can easily be tailored to human chromosome scales, which would enable the whole genome to be visualized in seconds.

8.
Protein Sci ; 5(8): 1477-89, 1996 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-8844839

RESUMEN

The role of charges near the pore mouth has been discussed in theoretical work about ion channels. To introduce new negative charges in a channel protein, amino groups of porin from Rhodobacter capsulatus 37b4 were succinylated with succinic anhydride, and the precise extent and sites of succinylations and structures of the succinylporins determined by mass spectrometry and X-ray crystallography. Molecular weight and peptide mapping analyses using matrix-assisted laser desorption-ionization mass spectrometry identified selective succinylation of three lysine-epsilon-amino groups (Lys-46, Lys-298, Lys-300) and the N-terminal alpha-amino group. The structure of a tetra-succinylated porin (TS-porin) was determined to 2.4 A and was generally found unchanged in comparison to native porin to form a trimeric complex. All succinylated amino groups found in a mono/di-succinylated porin (MS-porin) and a TS-porin are localized at the inner channel surface and are solvent-accessible: Lys-46 is located at the channel constriction site, whereas Lys-298, Lys-300, and the N-terminus are all near the periplasmic entrance of the channel. The Lys-46 residue at the central constriction loop was modeled as succinyl-lysine from the electron density data and shown to bend toward the periplasmic pore mouth. The electrical properties of the MS-and TS-porins were determined by reconstitution into black lipid membranes, and showed a negative charge effect on ion transport and an increased cation selectivity through the porin channel. The properties of a typical general diffusion porin changed to those of a channel that contains point charges near the pore mouth. The single-channel conductance was no longer a linear function of the bulk aqueous salt concentration. The substantially higher cation selectivity of the succinylated porins compared with the native protein is consistent with the increase of negatively charged groups introduced. These results show tertiary structure-selective modification of charged residues as an efficient approach in the structure-function evaluation of ion channels, and X-ray crystallography and mass spectrometry as complementary analytical tools for defining precisely the chemically modified structures.


Asunto(s)
Fragmentos de Péptidos/análisis , Porinas/química , Estructura Terciaria de Proteína , Rhodobacter capsulatus/química , Secuencia de Aminoácidos , Cromatografía Líquida de Alta Presión , Conductometría , Cristalografía por Rayos X , Bromuro de Cianógeno/química , Lisina/química , Potenciales de la Membrana , Datos de Secuencia Molecular , Fosfatidilcolinas/química , Fosfatidilcolinas/metabolismo , Porinas/metabolismo , Probabilidad , Unión Proteica , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Estereoisomerismo , Relación Estructura-Actividad , Tripsina/metabolismo
9.
Eur J Biochem ; 217(1): 105-14, 1993 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-8223547

RESUMEN

In cell extracts of Lactobacillus delbrückii ssp. lactis DSM7290 a peptidase with the ability to hydrolyse Phe-beta-naphthylamide (Phe-beta-NA) and His-beta-NA could be detected. Escherichia coli lacking the enzyme activity in an enzymic plate assay was used to screen high-copy-number and low-copy-number plasmid libraries of size-fractionated Lactobacillus DNA. Clones with the desired phenotype were detected, and the gene, designated pepN, was further subcloned and sequenced. A large open reading frame of 2529 nucleotides is predicted to encode a protein of 843 amino acids (95358 Da). Comparison of the pepN gene from Lb. delbrückii ssp. lactis DSM7290 indicates that it is homologous to genes of the family of Zn(2+)-metallohydrolases and PepN shows identity with the active centre Zn(2+)-binding motif of these enzymes. The substrate Lys-beta-NA is more effectively cleaved than Phe-beta-NA or His-beta-NA which were used for screening in E. coli. The cloned pepN gene was efficiently overexpressed in E. coli and subcloning of the gene in Lactobacillus casei resulted in a moderate overexpression of approximately 20-fold. The pepN gene product was purified from the pepN-deficient E. coli strain CM89, using the substrate Lys-p-nitroanilide (Lys-NH-Ph) in the assay procedure. In a four-step procedure including streptomycin sulfate precipitation, anion-exchange chromatography and gel filtration the peptidase was purified to electrophoretic homogeneity.


Asunto(s)
Aminopeptidasas/genética , Clonación Molecular , Lactobacillus/enzimología , Análisis de Secuencia de ADN , Secuencia de Aminoácidos , Aminopeptidasas/química , Aminopeptidasas/metabolismo , Secuencia de Bases , Escherichia coli/genética , Regulación Bacteriana de la Expresión Génica , Lactobacillus/genética , Metales/farmacología , Datos de Secuencia Molecular , Plásmidos , Mapeo Restrictivo , Homología de Secuencia de Ácido Nucleico , Especificidad por Sustrato , Transformación Bacteriana , Zinc/metabolismo
10.
J Antimicrob Chemother ; 26 Suppl B: 147-52, 1990 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-2258341

RESUMEN

In a double-blind multicentre study the efficacy and safety of a single-dose treatment with pefloxacin (800 mg) was compared with a five-day treatment regimen of 960 mg co-trimoxazole twice daily in the therapy of acute uncomplicated cystitis in women. In order to maintain blindness, patients in the pefloxacin group received placebo to complement the full number of tablets. Nine centres were involved; 155 patients received pefloxacin and 161 patients received co-trimoxazole. Of these, 140 patients treated with pefloxacin and 145 with co-trimoxazole were considered valid for efficacy and safety analysis. At the first follow-up, after seven to ten days, 97.1% of the pefloxacin group and 95.2% of the co-trimoxazole group were bacteriologically cured. At the second follow-up visit, after 28 to 42 days, the urine culture was negative in 95.0% of the pefloxacin group and 90.3% of the co-trimoxazole group. A single dose of 800 mg pefloxacin was demonstrated to be as safe and at least as effective as a five-day regimen of co-trimoxazole in the treatment of uncomplicated cystitis.


Asunto(s)
Cistitis/tratamiento farmacológico , Pefloxacina/administración & dosificación , Combinación Trimetoprim y Sulfametoxazol/administración & dosificación , Adulto , Método Doble Ciego , Esquema de Medicación , Femenino , Estudios de Seguimiento , Humanos , Persona de Mediana Edad , Pefloxacina/uso terapéutico , Combinación Trimetoprim y Sulfametoxazol/uso terapéutico
11.
Reprod Biomed Online ; 6(3): 277-80, 2003.
Artículo en Inglés | MEDLINE | ID: mdl-12735857

RESUMEN

Egg donation is associated with medical and surgical risks regardless of the source of eggs, be it through commercial, altruistic or more recent egg-share donors. Egg sharing is the only system that does not turn a healthy woman (the donor) into a patient. Using carefully selected egg-share donors, pregnancy rates for both donor and recipient are as good as any egg-donation programme, with one cohort of eggs being used with more efficiency. We propose that anonymous egg sharing, as licensed by the Human Fertilisation and Embryology Authority (HFEA), minimizes risk, is ethically sound and should be considered as the only acceptable form of anonymous egg donation.


Asunto(s)
Transferencia de Embrión , Donación de Oocito/ética , Donación de Oocito/métodos , Altruismo , Femenino , Regulación Gubernamental , Humanos , Masculino , Óvulo , Embarazo , Resultado del Embarazo , Técnicas Reproductivas , Riesgo , Reino Unido
12.
Hum Reprod ; 11(5): 1126-31, 1996 May.
Artículo en Inglés | MEDLINE | ID: mdl-8671404

RESUMEN

The present acute shortage of eggs for donation cannot be overcome unless adequate guidelines are set to alleviate the anxieties regarding payments, in cash or kind, to donors. The current Human Fertilisation and Embryology Authority (HFEA) guidelines do not allow direct payment to donors but accept the provision of lower cost or free in vitro fertilization (IVF) treatment to women in recognition of oocyte donation to anonymous recipients. Egg-sharing achieved in this way enables two infertile couples to benefit from a single surgical procedure. However, the practical guidelines related to this approach are ill-defined at the present time leading to some justifiable uncertainty. A pilot study was therefore undertaken in order to establish the place of egg-sharing in an assisted conception programme. The current HFEA guidelines on medical screening of patients, counselling, age and rigid anonymity between the donor and recipient were followed. The study involved 55 women (25 donors and 30 recipients) in 73 treatment cycles involving fresh and frozen-thawed embryos. Donors were previous IVF patients who, regardless of their ability to pay, shared their eggs equally with matched anonymous recipients. They paid only for their consultations and tests right up to the point of being matched with a recipient. The sole recipient paid the cost applicable in egg donation of a single egg collection, although both received embryo transfers. The results indicate that although the recipients were older than the donors (41.4 +/- 0.9 versus 31.6 +/- 0.5 years), and there was no difference in the mean number of eggs allocated, the percentage fertilization rates, or the mean number of embryos transferred, there were more births per patient amongst recipients than amongst donors (30 versus 20%). We conclude that providing the donors are selected carefully, this scheme whereby a sub-fertile donor helps a sub-fertile recipient is a very constructive way of solving the problem of the shortage of eggs for donation. There are also the advantages of including a group of women who would otherwise be denied treatment. Problems related to 'patient coercion' can, in our view, be fully overcome by the application of strict common-sense safeguards. The ideal of pure altruism is not without its medical and moral risk. The success of egg-sharing depends on shared interests and a degree of altruism between the donor, the recipient and the centre. The current HFEA guidelines should be applauded for enabling a highly effective concept of mutual help to develop.


Asunto(s)
Ética , Donación de Oocito , Adulto , Envejecimiento , Niño , Protección a la Infancia , Transferencia de Embrión , Femenino , Fertilización In Vitro , Humanos , Infertilidad Femenina/terapia , Donación de Oocito/estadística & datos numéricos , Embarazo , Resultado del Embarazo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA