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1.
Hum Reprod ; 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38775331

RESUMO

STUDY QUESTION: Does the use of preimplantation genetic testing for aneuploidies (PGT-A), personalized embryo transfer with endometrial receptivity assay (pET-ERA), or the use of donated oocytes modify the incidence of biochemical pregnancy loss (BPL) in frozen single embryo transfer (FSET)? SUMMARY ANSWER: Following FSET, BPL incidence does not differ between own and donated oocytes, and the use of PGT-A with euploid embryo transfer or pET-ERA results in a similar incidence of BPL compared to cycles without embryo or endometrial analysis. WHAT IS KNOWN ALREADY: BPL occurs frequently after IVF, and many factors have been associated with its incidence. The etiology of BPL is not well known, but the most probable cause seems to be either a low-quality embryo or impaired endometrial maintenance. The impact of techniques diagnosing embryonic ploidy or endometrial receptivity on BPL incidence and the BPL incidence between own and donated oocytes have not been analyzed. STUDY DESIGN, SIZE, DURATION: This is a retrospective cohort study analyzing the incidence of BPL over 3741 cycles of FSET derived from own (2399 cycles) and donated (1342 cycles) oocytes between January 2013 and January 2022 in 1736 of which PGT-A, pET-ERA, or both were applied. PARTICIPANTS/MATERIALS, SETTING, METHODS: We defined BPL as a pregnancy diagnosed only by serum ß-hCG > 10 UI/l followed by a decrease that does not result in a clinical pregnancy. Clinical pregnancy was defined as the presence of gestational sac on transvaginal ultrasound. We compared BPL rates among patients undergoing 2399 FSETs from own oocytes, which comprised 1310 cycles of embryos analyzed by PGT-A, 950 cycles of untested embryos, 30 cycles of untested embryos with pET-ERA, and a subgroup of 109 cycles analyzed by both PGT-A and pET-ERA. We also included a total of 1342 FSET cycles from donated oocytes comprising 132, 1055, 140, and 15 cycles in the same groups, respectively. MAIN RESULTS AND THE ROLE OF CHANCE: In FSET from own oocytes, the overall BPL rate per embryo transfer was 8.2% (95% CI [7.09-9.33]). In untested embryo transfers, the BPL rate was 7.5% [5.91-9.37]. In the PGT-A group, the BPL rate was 8.8% [7.32-10.47]. In the pET-ERA group, the rate was 6.7% [0.82-22.07]. In the PGT-A+ERA group, the rate was 6.5% [2.65-12.90]. No significant differences were found (P = 0.626). A multivariate analysis considering clinically meaningful variables that were significantly different among groups, taking the untested embryos/endometrium group as a reference, showed comparable incidences among groups. For PGT-A, the adjusted odds ratio (AdjOR) was 1.154 [0.768-1.735] (P = 0.49) and for PGT-A+ERA 0.885 [0.330-2.375] (P = 0.808). Because of a low number of registered cases in the pET-ERA group, and to prevent statistical errors and convergence issues, this group was excluded from further analysis. In FSET of donated oocytes, the overall BPL rate per embryo transfer was 4.9% [3.76-6.14]. In the PGT-A group, the BPL rate was 6.8% [3.16-12.55]. In the pET-ERA group, the rate was 5.0% [2.03-10.03]. In untested embryo transfers, the rate was 4.7% [3.46-6.10]. No cases occurred in the PGT-A+ERA group, and no significant differences were found (P = 0.578). The multivariate analysis showed comparable incidences among groups. For PGT-A the AdjOR was 1.669 [0.702-3.972] (P = 0.247) and for pET-ERA 1.189 [0.433-3.265] (P = 0.737). The PGT-A+ERA group was eliminated from the model to prevent statistical errors and convergence issues because no BPL cases were registered in this group. In the multivariate analysis, when the sources of oocytes were compared, own versus donated, no significant differences were found in the incidence of BPL. LIMITATIONS, REASONS FOR CAUTION: This was a retrospective cohort study with potential biases. In addition, we were unable to control differences among groups due to modifications in medical or laboratory protocols during this long time period, which may modify the relationships being addressed. Factors previously associated with BPL, such as immunological conditions other than thyroid autoimmunity, were not considered in this study. Limited sample sizes of some groups may limit the statistical power for finding differences that can be present in the general population. WIDER IMPLICATIONS OF THE FINDINGS: BPL may be related to a mechanism not associated with the chromosomal constitution of the embryo or the transcriptome of the endometrium. More studies are needed to explore the factors associated with this reproductive issue. STUDY FUNDING/COMPETING INTEREST(S): No specific funding was available for this study. None of the authors have a conflict of interest to declare with regard to this study. TRIAL REGISTRATION NUMBER: This trial was registered at clinicaltrials.gov (NCT04549909).

2.
ACS Appl Mater Interfaces ; 15(23): 28705-28715, 2023 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-37269290

RESUMO

In this work we study conjugated polyelectrolyte (CPE) films based on polyamidoamine (PAMAM) dendrimers of generations G1 and G3. These fractal macromolecules are compared to branched polyethylenimine (b-PEI) polymer using methanol as the solvent. All of these materials present a high density of amino groups, which protonated by methoxide counter-anions create strong dipolar interfaces. The vacuum level shift associated to these films on n-type silicon was 0.93 eV for b-PEI, 0.72 eV for PAMAM G1 and 1.07 eV for PAMAM G3. These surface potentials were enough to overcome Fermi level pinning, which is a typical limitation of aluminium contacts on n-type silicon. A specific contact resistance as low as 20 mΩ·cm2 was achieved with PAMAM G3, in agreement with the higher surface potential of this material. Good electron transport properties were also obtained for the other materials. Proof-of-concept silicon solar cells combining vanadium oxide as a hole-selective contact with these new electron transport layers have been fabricated and compared. The solar cell with PAMAM G3 surpassed 15% conversion efficiency with an overall increase of all the photovoltaic parameters. The performance of these devices correlates with compositional and nanostructural studies of the different CPE films. Particularly, a figure-of-merit (Vσ) for CPE films that considers the number of protonated amino groups per macromolecule has been introduced. The fractal geometry of dendrimers leads to a geometric increase in the number of amino groups per generation. Thus, investigation of dendrimer macromolecules seems a very good strategy to design CPE films with enhanced charge-carrier selectivity.

3.
Phys Chem Chem Phys ; 18(11): 7632-40, 2016 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-26376836

RESUMO

A comprehensive Raman resonance scattering study of ZnSxSe1-x (ZnSSe) solid solutions over the whole compositional range (0 ≤ x ≤ 1) has been carried out using 325 and 455 nm excitation wavelengths. The Raman scattering intensities of LO ZnS-like and ZnSe-like phonon modes, corresponding to pure S and Se vibrations, respectively, are revealed to be significantly enhanced when excited with 325 nm excitation in the case of S vibrations, and with 455 nm in the case of Se vibrations. This behavior is explained by the interaction of the excitation photons with the corresponding S or Se electronic states in the conduction band, and further confirmed by first principles simulations. These findings advance the fundamental understanding of the coupling between the electronic transitions and photons in the case of Raman resonance effects, and provide inputs for further studies of lattice dynamics, especially in the case of chalcogenide materials. Additionally, the coexistence of modes corresponding to only S vibrations and only Se vibrations in the ZnSSe alloys makes these results applicable for the compositional assessment of ZnSSe compounds.

4.
J Cytol ; 30(1): 1-7, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23661932

RESUMO

BACKGROUND: Cyclin-A and cyclin-E are regulators of G1-S phase of normal cell cycle. Integration of human papilloma virus high-risk (HR-HPV) could alter this mechanism, and its overexpression has been associated with poor prognosis in cervical cancer. AIM: To determine the expression of cyclin-A and cyclin-E, types of HR-HPV and physical state of DNA in cytologies with the diagnosis of low-grade squamous intraepithelial lesion (LSIL). MATERIALS AND METHODS: 115 cytological specimens in liquid base (liquid-PREP(™)) were analyzed. 25 specimens were with no signs of SIL (NSIL) and without HPV; 30 with NSIL with low-risk HPV (LR-HPV); 30 with NSIL with HR-HPV; and 30 with both LSIL and HR-HPV. The expression of cyclins was evaluated by immunocytochemistry; and the detection of viral DNA was done by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLPs) for genotyping or sequencing of HPV. The physical state of HPV was evaluated by in situ hybridization with amplification with tyramide. RESULTS: In the cytologies NSIL with LR-HPV, the expression of cyclin-A and cyclin-E was found respectively in 23.3% and 33.3% of the specimens. Among the specimens of NSIL with HR-HPV, 33.3% expressed cyclin-A and 40% cyclin-E, while 100% of the LSILs expressed the 2 cyclins. On the other hand, 100% of the samples NSIL with LR-HPV presented an episomal pattern. Of the specimens of NSIL with HR-HPV, 56.6% exhibited an episomal pattern, 23.3% integrated and 20%, mixed. Among the LSILs, 90% were mixed and 10% integrated. CONCLUSIONS: The cyclins A and E are present in the LSILs that occur predominantly in mixed state in the presence of HR-HPV.

5.
Plant Dis ; 96(9): 1280-1285, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30727155

RESUMO

Fusarium head blight (FHB) is an important disease of wheat and barley worldwide. The disease is primarily caused by members of the Fusarium graminearum species complex, consisting of at least 14 phylogenetically distinct species. To determine the population structure of the FHB pathogens in a naturally infected disease nursery located at Jianyang, Fujian province, China, 160 isolates of the F. graminearum complex were recovered from symptomatic wheat spike samples collected in two consecutive years (2008 and 2009) and characterized using species- and chemotype-specific polymerase chain reaction as well as variable number tandem repeat (VNTR) markers. All isolates analyzed were identified as F. asiaticum except for one isolate, which was identified as F. avenaceum. Among the 159 F. asiaticum isolates, 126 (79%) isolates were of the nivalenol (NIV) type while 29 (18%) isolates were of the 15-acetyl deoxynivalenol type and only 4 (3%) isolates were of the 3-acetyl deoxynivalenol type. The 10 VNTR markers revealed 124 distinct haplotypes and 76 polymorphic alleles across the whole population. The two subpopulations (FA-08 and FA-09) grouped based on the year of collection exhibited low genetic differentiation (Fst = 0.032) and high gene flow (Nm = 15.13). However, a significant genetic differentiation was found within the NIV-type isolates as revealed by the Structure software. The pairwise linkage disequilibrium tests did not support the hypothesis of random mating in the population because half (48.8%) of the locus pairs showed a linkage disequilibrium (P > 0.05). Our results suggest that FHB in this nursery was caused by a genetically homogenous and non-random mating population of F. asiaticum in 2008 and 2009, which consisted of all three trichothecene types with various levels of aggressiveness.

6.
Genesis ; 46(1): 19-28, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18196602

RESUMO

Retinoids play critical regulatory roles in the maintenance of mammalian epithelia and exert pleiotropic effects through nuclear receptors. RXRalpha, which is a ligand-dependent transcription factor, is the most abundant RXR isotype expressed in cervical epithelia, and may play a crucial role in cervix development and homeostasis. We have previously described a mouse model to induce the temporally controlled epithelia-specific somatic mutagenesis of RXRalpha alleles in epidermis. To study the role of RXRalpha in cervical homeostasis, we ablated RXRalpha in cervix epithelial cells of adult mice. We found that such mutant mice develop ectocervical atrophy with moderate epidermoid metaplasia. In addition, we report a simultaneous increase of cell proliferation and apoptosis levels accompanied by alteration in the expression of genes involved in both processes.


Assuntos
Colo do Útero/fisiologia , Células Epiteliais/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Receptor X Retinoide alfa/genética , Receptor X Retinoide alfa/fisiologia , Animais , Apoptose , Proliferação de Células , Epiderme/metabolismo , Feminino , Homeostase , Ligantes , Camundongos , Camundongos Mutantes , Mutagênese , Mutação
7.
Acta Obstet Gynecol Scand ; 82(5): 439-42, 2003 May.
Artigo em Inglês | MEDLINE | ID: mdl-12752074

RESUMO

BACKGROUND AND OBJECTIVES: Collection strategy is the first step for collecting good quality cord blood (CB) units. There are two principal different techniques to collect CB from the umbilical vein: in the delivery room while the placenta is still in the uterus by midwives and obstetricians or in an adjacent room after placental delivery by CB-bank trained personnel. In this study, the benefits and disadvantages between two different CB collection strategies were evaluated in order to improve CB bank methodology. DESIGN AND METHODS: Valencia CB bank maintains the two different collection strategies aforementioned. Before processing CB units, volume was calculated and samples were drawn for cell counts. After processing and before cryopreservation, samples for cell counts, CD34 analysis, viability, clonogenic assays and microbiology were drawn directly from the bags. We compared the efficiency of the two collection techniques. RESULTS: Obstetric date and umbilical CB was obtained from 848 vaginal (484 collected in uterus and 364 collected ex uterus). The proportion of excluded CB units before processing was 33% for ex uterus and 25% for in uterus. The difference was statistically significant. A larger volume and a higher number of total nucleated cells, CD34+ cells and CFUs were harvested in the in uterus collection group. INTERPRETATION AND CONCLUSIONS: Based on our findings, we conclude that the mode of collection influences the hematopoietic content of CB donations. Collection before placental delivery is the best approach to CB collection and allows optimizing CB bank methodology.


Assuntos
Coleta de Amostras Sanguíneas/métodos , Criopreservação/métodos , Parto Obstétrico , Sangue Fetal/citologia , Antígenos CD34/análise , Parto Obstétrico/métodos , Feminino , Transplante de Células-Tronco Hematopoéticas , Células-Tronco Hematopoéticas/imunologia , Humanos , Placenta/irrigação sanguínea , Gravidez , Espanha , Estatísticas não Paramétricas
8.
Bone Marrow Transplant ; 31(4): 269-73, 2003 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-12621461

RESUMO

The use of cord blood (CB) for transplantation has increased greatly in recent years. The collection strategy is the first step in collecting good-quality CB units. There are two main techniques for collecting CB from the umbilical vein: in the delivery room while the placenta is still in the uterus by midwives and obstetricians or in an adjacent room after placental delivery by CB bank trained personnel. In this study, the benefits and disadvantages between the two different CB collection strategies were evaluated, in order to improve CB bank methodology. Valencia CB bank maintains the two different collection strategies. CB was obtained from 569 vaginal and 70 caesarean deliveries and obstetrical and clinical charts were reviewed. Before processing CB units, volume was calculated and samples were drawn for cell counts. After processing and before cryopreservation samples were drawn for cell counts, CD34+cell analysis, viability, clonogenic assays and microbiology were drawn directly from the bags. We compared the efficiency of the two collection techniques. Obstetric data and umbilical CB were obtained from 569 vaginal (264 collected in utero and 305 collected ex utero) and 70 caesarean deliveries. The proportion of excluded CB units before processing was 33% for vaginal ex utero, 25% for vaginal in utero and 46% for caesarean deliveries. Differences were statistically significant. For vaginal deliveries a larger volume and a higher number of nucleated cells, percentage of CD34+ cells and colony-forming units (CFUs) were harvested in the in utero collection group. There was no statistical difference between CB collected after placental expulsion from vaginal and caesarean deliveries. Comparison between all vaginal and caesarean deliveries did not show any difference. We conclude that the mode of collection influences the haematopoietic content of CB donations. Collection before placental delivery is the best approach to CB collection and allows optimisation of CB bank methodology. Caesarean deliveries seem to contain similar progenitor content to vaginal deliveries.


Assuntos
Sangue Fetal/citologia , Células-Tronco Hematopoéticas/citologia , Adulto , Peso ao Nascer , Separação Celular/métodos , Ensaio de Unidades Formadoras de Colônias , Criopreservação , Parto Obstétrico , Feminino , Idade Gestacional , Humanos , Recém-Nascido , Idade Materna , Placenta , Gravidez , Preservação de Tecido/métodos , Veias Umbilicais
9.
Am J Physiol Heart Circ Physiol ; 279(2): H772-8, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10924077

RESUMO

Angiogenesis is a component of the multifactoral adaptation to exercise training, and vascular endothelial growth factor (VEGF) is involved in extracellular matrix changes and endothelial cell proliferation. However, there is limited evidence supporting the role of VEGF in the exercise training response. Thus we studied mRNA levels of VEGF, using quantitative Northern analysis, in untrained and trained human skeletal muscle at rest and after a single bout of exercise. Single leg knee-extension provided the acute exercise stimulus and the training modality. Four biopsies were collected from the vastus lateralis muscle at rest in the untrained and trained conditions before and after exercise. Training resulted in a 35% increase in muscle oxygen consumption and an 18% increase in number of capillaries per muscle fiber. At rest, VEGF/18S mRNA levels were similar before (0.38 +/- 0.04) and after (1.2 +/- 0.4) training. When muscle was untrained, acute exercise greatly elevated VEGF/18S mRNA levels (16.9 +/- 6.7). The VEGF/18S mRNA response to acute exercise in the trained state was markedly attenuated (5.4 +/- 1.3). These data support the concept that VEGF is involved in exercise-induced skeletal muscle angiogenesis and appears to be subject to a negative feedback mechanism as exercise adaptations occur.


Assuntos
Fatores de Crescimento Endotelial/genética , Exercício Físico/fisiologia , Regulação da Expressão Gênica , Linfocinas/genética , Músculo Esquelético/fisiologia , Adaptação Fisiológica , Adulto , Capilares/fisiologia , Fator 2 de Crescimento de Fibroblastos/genética , Humanos , Articulação do Joelho , Masculino , Músculo Esquelético/irrigação sanguínea , Oxigênio/sangue , Consumo de Oxigênio , Descanso , Fator A de Crescimento do Endotélio Vascular , Fatores de Crescimento do Endotélio Vascular
10.
Biotechnol Bioeng ; 40(7): 753-9, 1992 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-18601178

RESUMO

Ethanol production was evaluated from eucalyptus wood hemicellulose acid hydrolysate using Pichia stipitis NRRL Y-7124. An initial lag phase characterized by flocculation and viability loss of the yeast inoculated was observed. Subsequently, cell regrowth occurred with sequential consumption of sugars and production of ethanol. Polyol formation was detected. Acetic acid present in the hydrolysate was an important inhibitor of the fermentation, reducing the rate and the yield. Its toxic effect was due essentially to its undissociated form. The fermentation was more effective at an oxygen transfer rate between 1.2 and 2.4 mmol/L h and an initial pH of 6.5. The hydrolysate used in the experiences had the following composition (expressed in grams per liter): xylose 30, arabinose 2.8, glucose 1.5, galactose 3.7, mannose 1.0, cellobiose 0.5, acetic acid 10, glucuronic acid 1.5, and galacturonic acid 1.0. The best values obtained were maximum ethanol concentration 12.6 g/L, fermentation time 75 h, fermentable sugar consumption 99% ethanol yield 0.35 g/g sugars consumed, and volumetric ethanol productivity 4 g/L day. (

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