RESUMEN

Neutron scattering instruments play an important role in studying the inner structure of materials. A neutron beam monitor is a detector commonly used in a neutron scattering instrument. The detection efficiency for most neutron beam monitors is quite low (10-4-10-6). However, in some experiments with a low neutron flux, such as small angle neutron scattering (SANS) and inelastic neutron scattering experiments, a neutron beam monitor with a higher detection efficiency (∼1% for thermal neutrons) is required to reduce the duration of the experiment. To meet this requirement, a ceramic gas electron multiplier-based neutron beam monitor equipped with a 1 µm 10B4C neutron converter was developed in this study. Its performance was determined both experimentally and in simulations. The detection efficiency in the wavelength range of 1.8-5.5 Å was measured experimentally and was confirmed by the simulation results. An algorithm based on event selection and position reconstruction was developed to improve the spatial resolution to about 1 mm full-width-half-maximum. The wavelength spectrum was measured in beamline 20 (BL20) and agreed well with the results obtained using a commercial monitor. The maximum counting rate was 1.3 MHz. The non-uniformity over the whole 100 × 100 mm2 active area was determined to be 1.4%. Due to the excellent performance of this monitor, it has been used in several neutron instruments, such as the SANS and the High-Energy Direct-Geometry Inelastic Spectrometer instruments in the China spallation neutron source.

RESUMEN

Repurposing existing drugs to inhibit SARS-CoV-2 infection in airway epithelial cells (AECs) is a quick way to find novel treatments for COVID-19. Computational screening has found dicoumarol (DCM), a natural anticoagulant, to be a potential SARS-CoV-2 inhibitor, but its inhibitory effects and possible working mechanisms remain unknown. Using air-liquid interface culture of primary human AECs, we demonstrated that DCM has potent antiviral activity against the infection of multiple Omicron variants (including BA.1, BQ.1 and XBB.1). Time-of-addition and drug withdrawal assays revealed that early treatment (continuously incubated after viral absorption) of DCM could markedly inhibit Omicron replication in AECs, but DCM did not affect the absorption, exocytosis and spread of viruses or directly eliminate viruses. Mechanistically, we performed single-cell sequencing analysis (a database of 77,969 cells from different airway locations from 10 healthy volunteers) and immunofluorescence staining, and showed that the expression of NAD(P)H quinone oxidoreductase 1 (NQO1), one of the known DCM targets, was predominantly localised in ciliated AECs. We further found that the NQO1 expression level was positively correlated with both the disease severity of COVID-19 patients and virus copy levels in cultured AECs. In addition, DCM treatment downregulated NQO1 expression and disrupted signalling pathways associated with SARS-CoV-2 disease outcomes (e.g., Endocytosis and COVID-19 signalling pathways) in cultured AECs. Collectively, we demonstrated that DCM is an effective post-exposure prophylactic for SARS-CoV-2 infection in the human AECs, and these findings could help physicians formulate novel treatment strategies for COVID-19.

Asunto(s)

COVID-19 , Dicumarol , Humanos , SARS-CoV-2 , COVID-19/genética , Epitelio

RESUMEN

BACKGROUND: Maternal diabetes compromises the quality and developmental potential of oocytes. Therefore, it is important to study how to ameliorate the adverse effects of diabetes on oocyte quality. Epigallocatechin gallate (EGCG) has a variety of physiological activities, including anti-inflammatory, antioxidant, and anti-diabetes. In the present study, we evaluated the effect of EGCG on the maturation of diabetic oocytes in vitro. OBJECTIVE: Investigating the role of EGCG in restoring the adverse effects of diabetes on oocyte quality. METHODS: Diabetes mouse model was established by a single injection of streptozotocin (STZ). Oocytes were collected and matured in vitro with/without EGCG in M16 medium. RESULTS: Compared with control, diabetic oocytes have a higher frequency of spindle defects and chromosome misalignment, but EGCG effectively reduces the incidence of oocytes with abnormal spindle assembly and chromosome mismatches. Moreover, the abnormal mitochondrial membrane potential (MMP) of diabetic oocytes is significantly alleviated by EGCG, and the reduced expression of genes regulating mitochondrial fusion (Mfn1 and Mfn2) and fission (Drp1) in diabetic oocytes is significantly increased while EGCG is added. EGCG also decreases the higher level of reactive oxygen species (ROS) in diabetic oocytes that may be regulated by the increased expression of superoxide dismutase 1 (Sod1) and superoxide dismutase 2 (Sod2). EGCG can also reduce the DNA damage of diabetic oocytes. CONCLUSIONS: Our results suggest that EGCG, at least partially, improve the quality of diabetic oocytes.

Asunto(s)

Catequina , Diabetes Gestacional , Ratones , Femenino , Humanos , Embarazo , Animales , Oocitos , Antioxidantes/farmacología , Catequina/farmacología

RESUMEN

With WO3/BiVO4/MXene ternary composite layers as a working electrode, a smart volumetric photoelectrochemical system using electrostatic bias voltage inducted by atmospheric electric field was developed. Under single sun illumination and 0.8 V hardwired bias, the current response of the ternary electrode is 1.15 mA cm-2, which is 1.31 times higher than that of the WO3/BiVO4 electrode, mainly due to the higher charge transfer rate between the MXene layer and the BiVO4 structure. Further, the response of the ternary electrode increases to 1.39 mA cm-2 at an extra atmospheric electric field of 1100 V m-1. It can be demonstrated that the effect of the atmospheric electric field can be regarded as an extra hardwired bias of 0.101 V in the system. The experimental results reveal that the native carriers, including inducted electron/holes in MXene and BiVO4, and carriers in the electrolyte, are all effectively excited by the electrostatic induction of atmospheric electric field.

RESUMEN

SCOPE: Tea is a popular beverage worldwide and has many health functions. Protocatechuic acid (PCA) is an important bioactive component of tea and has benefit to health. In some cases, oocytes after ovulation may miss the optimal fertilization time and enter a postovulatory ageing process. Therefore, to investigate the role of PCA in delaying oocyte ageing is aimed. METHODS AND RESULTS: Metaphase II (MII) oocytes aged in vitro are randomly divided into three groups: control, aged, and aged + PCA. PCA treatment (30 µM) reduces the fragmentation rate and the incidence of abnormal spindle morphology and chromosome misalignment of oocytes aged 24 h in vitro. The mitochondrial dysfunction of aged oocytes, such as decreased mitochondrial membrane potential and excessive accumulation of reactive oxygen (ROS), is also alleviated by PCA. PCA also delays apoptosis of aged oocytes, and improves the sperm binding capacity. Otherwise, aged oocytes treated with PCA have a higher fertilization rate and blastocyst rate compared with untreated aged oocytes in vitro. CONCLUSION: PCA is an important bioactive ingredient of tea that improves aged oocyte quality, suggesting that PCA is available to improve the quality of aged oocytes in vitro.

Asunto(s)

Envejecimiento , Semen , Femenino , Masculino , Animales , Ratones , Oocitos/metabolismo , Té/metabolismo

RESUMEN

BACKGROUND: Human sperm concentration and motility have dropped dramatically (50%) in the past few decades, and environmental factors are involved in this decline. Long non-coding RNAs (lncRNA) have been discovered to be involved in many cellular processes including spermatogenesis. OBJECTIVE: This investigation aimed to explore the role of lncRNA8276 in murine spermatogenesis. MATERIALS AND METHODS: The expression of lncRNA8276 was modified by knockdown or overexpression in mouse testes and spermatogonial stem cells (C18-4 cell line). Sperm quality was determined in the F0 and F1 generations of mice. Furthermore, the underlying mechanisms were studied through gene expression and/or protein expression of spermatogenesis-related genes and cell junction-related genes by different methods. RESULTS: In the current investigation, we discovered that sperm lncRNA8276 was decreased by NH3 /H2 S in three generations (F0, F1, and F2) of mouse sperm. In vivo testicular knockdown of lncRNA8276 led to a decline in sperm concentration and motility in both F0 (muF0) and F1 (muF1) generations Moreover, knockdown lncRNA8276 decreased the gene and protein levels of important genes related to cell-cell junctions and spermatogenesis. The data were further confirmed in mouse spermatogonia stem cell line C18-4 cells through knockdown of lncRNA8276. DISCUSSION AND CONCLUSION: Our study suggests that lncRNA8276 may be involved in cell-cell junction formation in the mouse testis to regulate spermatogenesis. It may be a target for the modification of spermatogenesis and male fertility, or male contraception. This investigation offers a potential therapeutic strategy for male infertility.

Asunto(s)

Adhesión Celular , ARN Largo no Codificante , Espermatogénesis , Animales , Adhesión Celular/genética , Humanos , Masculino , Ratones , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , Semen , Espermatogénesis/genética , Espermatogonias , Testículo/metabolismo

RESUMEN

Objective@#To investigate the association between the left atrial appendage (LAA) volume and atrial fibrillation (AF) recurrence after radiofrequency catheter ablation.@*Methods@#We prospectively enrolled sixty-two patients with AF (40 cases with paroxysmal AF, 22 cases with persistent AF) who successfully underwent a first AF catheter ablation and had performed contrast-enhanced cardiac computed tomography (CT) prior to the procedure to measure LAA volumes in our hospital from January 2012 to August 2015. Circumferential pulmonary vein isolation was performed under the guidance of three-dimension mapping system (CARTO system). Linear ablation or ablation of complex fractioned atrial electrograms was also undertaken if necessary. All patients were followed up at the 3rd, 6th and 12th months after ablation by 24-hour ambulatory Holter monitoring, and were divided into the non-recurrence group (n=42) and the AF recurrence group (n=20). Univariate and multivariate Cox proportional hazards regression analysis were used to assess the factors related to AF recurrence. The receiver operating characteristic (ROC) curve was calculated to assess the best cut-off value of LAA volume to predict AF recurrence. Kaplan-Meier method was used to evaluate the rate of freedom from AF recurrence.@*Results@#Mean LAA volume in all patients was (9.5±3.6)ml. AF recurrence occurred in 20 patients (32%) during the follow-up period. The LAA volume was significantly larger in the AF recurrence group than in the non-recurrence group ((11.5±3.8)ml vs. (8.3±3.1)ml, P=0.002). In the univariate regression analysis, LAA volume (HR=1.36, 95%CI 1.14-1.82, P<0.001), persistent AF (HR=4.43, 95%CI 1.52-12.06, P<0.001) and hypertension (HR=1.61, 95%CI 1.13-2.04, P=0.041) were risk factors of AF recurrence. However, multivariate regression analysis revealed that LAA volume (HR=1.32, 95%CI 1.12-1.51, P<0.001) and persistent AF (HR=4.22, 95% CI 1.48-11.05, P<0.001) were independent predictors for AF recurrence after ablation. The receiver operating characteristic (ROC) curve analysis revealed that a LAA volume >8.80 ml was associated with AF recurrence after ablation (sensitivity: 94% and specificity: 66%, area under the curve=0.76). Kaplan-Meier analysis showed a lower rate free from AF recurrence in the group with LAA volume >8.80 ml (P<0.001).@*Conclusion@#Larger LAA volume is associated with AF recurrence after catheter ablation in patients with AF. A LAA volume greater than 8.80 ml could be used to predict AF recurrence after ablation.

RESUMEN

Thymopentin is a group of biologically active peptide secreted mainly by the epithelial cells of thymic cortex and medulla. Whether it promotes T cells production from human embryonic stem cells(hESCs) in vitro remains an elusive issue. In the present study, we develop a novel strategy that enhances T-cell lineage differentiation of hESCs in collagen matrix culture by sequential cytokine cocktails treatment combined with thymopentin stimulation. We observed that approximately 30.75% cells expressed CD34 on day 14 of the cultures and expressed the surface markers of erythroid, lymphoid and myeloid lineages. The results of colony assays and gene expressions by RT-PCR analysis also demonstrated that hematopoietic progenitor cells (HPCs) derived from hESCs were capable of multi-lineage differentiation. Further study revealed that culturing with thymopentin treatment, the CD34(+)CD45RA(+)CD7(+) cells sorted from HPCs expressed T-cell-related genes, IKAROS, DNTT, TCRγ and TCRß, and T-cell surface markers, CD3, cytoplasmic CD3, CD5, CD27, TCRγδ, CD4 and CD8. The differentiated cells produced the cytokines including IFN-γ, IL-2 and TNF-α in response to stimulation, providing the evidence for T-cell function of these cells. In conclusion, thymopentin enhances T-cell lineage differentiation from hESCs in vitro by mimicking thymus peptide environment in vivo.

Asunto(s)

Células Madre Embrionarias/citología , Linfopoyesis/efectos de los fármacos , Linfocitos T/citología , Timopentina/farmacología , Antígenos CD34/biosíntesis , Antígenos CD34/metabolismo , Antígenos CD7/metabolismo , Antígenos de Superficie/biosíntesis , Linaje de la Célula , Células Cultivadas , Células Madre Hematopoyéticas/citología , Humanos , Interferón gamma/biosíntesis , Interleucina-2/biosíntesis , Antígenos Comunes de Leucocito/metabolismo , Células Madre Pluripotentes/citología , Factor de Necrosis Tumoral alfa/biosíntesis

RESUMEN

Human embryonic stem (hES) cells with the capacity of self-renewal and multilineage differentiation are promising sources for generation of pancreatic islet cells for cell replacement therapy in diabetes. Here we induced hES cells into insulin-producing cells (IPCs) in a stepwise process which recapitulated islet organogenesis by directing cells through the stages resembling definitive endoderm, gut-tube endoderm, pancreatic precursor and cells that expressed pancreatic endocrine hormones. The dynamic expression of microRNAs (miRNAs) during the differentiation was analyzed and was compared with that in the development of human pancreatic islets. We found that the dynamic expression patterns of miR-375 and miR-7 were similar to those seen in the development of human fetal pancreas, whereas the dynamic expression of miR-146a and miR-34a showed specific patterns during the differentiation. Furthermore, the expression of Hnf1ß and Pax6, the predicted target genes of miR-375 and miR-7, was reciprocal to that of miR-375 and miR-7. Over-expression of miR-375 down-regulated the expression of gut-endoderm/pancreatic progenitor specific markers Hnf1ß and Sox9. Therefore, the miRNAs may directly or indirectly regulate the expression of pancreatic islet organogenesis-specific transcription factors to control the differentiation and maturation of pancreatic islet cells.

Asunto(s)

Diferenciación Celular/genética , Células Madre Embrionarias/metabolismo , Células Secretoras de Insulina/metabolismo , MicroARNs/genética , Células Madre Embrionarias/citología , Proteínas del Ojo/biosíntesis , Proteínas del Ojo/genética , Regulación del Desarrollo de la Expresión Génica , Factor Nuclear 1-beta del Hepatocito/biosíntesis , Factor Nuclear 1-beta del Hepatocito/genética , Proteínas de Homeodominio/biosíntesis , Proteínas de Homeodominio/genética , Humanos , Insulina/biosíntesis , Islotes Pancreáticos/metabolismo , MicroARNs/biosíntesis , Factor de Transcripción PAX6 , Factores de Transcripción Paired Box/biosíntesis , Factores de Transcripción Paired Box/genética , Proteínas Represoras/biosíntesis , Proteínas Represoras/genética , Factor de Transcripción SOX9/biosíntesis , Factor de Transcripción SOX9/genética

RESUMEN

Human embryonic stem (hES) cells can differentiate into cells of the three germ layers in vitro and serve as a powerful resource to study mechanisms involved in cell fate decisions. However, it is difficult to promote the directed and efficient differentiation of hES cells toward a specific lineage. Here we establish a stepwise strategy for generating hemato-endothelial and cardiac precursors from hES cells in single culture conditions. The efficiency of committing hES cells to three cell lineages was significantly higher with our approach than with exposure to single or multiple cytokines. Efficiency was determined using quantitative analysis by gene expression, flow cytometry, and colony assays. Several cytokines were sufficient to drive the efficient differentiation of hES cells into specific lineages. Each of these factors appeared to regulate specific steps of differentiation: BMP4 promoted the efficient formation of mesoderm; bFGF induced the differentiation of these mesodermal precursors to the hemangioblast fate; VEGF and TPO were required for the production of committed hematopoietic progenitors. This stepwise control of differentiation in vitro leads to a high frequency of hemato-endothelial and cardiac precursors derived from hES cells and offers a unique model for studying the molecular and cellular events that regulate hematopoiesis and cardiogenesis.

Asunto(s)

Linaje de la Célula/fisiología , Citocinas/fisiología , Cuerpos Embrioides/citología , Células Madre Embrionarias/citología , Células Endoteliales/citología , Células Endoteliales/fisiología , Corazón/embriología , Células Madre Hematopoyéticas/citología , Diferenciación Celular/fisiología , Células Cultivadas , Cuerpos Embrioides/fisiología , Células Madre Embrionarias/fisiología , Células Madre Hematopoyéticas/fisiología , Humanos , Mesodermo/citología , Mesodermo/embriología , Miocardio/citología

RESUMEN

OBJECTIVE: To compare the clinical outcomes of gonadotropin-releasing hormone (GnRH) antagonist (GnRH-ant) fixed protocol with GnRH agonist (GnRH-a) long protocol in infertile patients with normal ovarian reserve function in their first in vitro fertilization-embryo transfer (IVF-ET) cycle, and to explore the feasibility and advantage of GnRH antagonist protocol performed in normal responders. METHODS: From January 2011 to June 2011, 771 infertile women with normal ovarian reserve function underwent their first IVF or intracytoplasmic sperm injection (ICSI) cycles in Peking University Third Hospital, which were divided into 245 cycles in GnRH-ant fixed protocol group (GnRH-ant group) and 526 cycles in GnRH-a long protocol group (GnRH-a group). The data of general demographic, treatment and clinical outcome were compared between two groups. RESULTS: Age, infertile duration, body mass index (BMI), baseline serum follicle-stimulating hormone (FSH) and estradiol levels between two groups did not reached statistical difference (P > 0.05). The level of estradiol was (12 289 ± 6856) pmol/L in GnRH-ant group and (14 934 ± 8007) pmol/L in GnRH-a group at day of hCG injection. The mean length of stimulation was (10.3 ± 1.2) days in GnRH-ant group and (12.8 ± 1.6) days in GnRH-a group. The dose of gonadotropin was (2013 ± 607) U in GnRH-ant group and (2646 ± 913) U in GnRH-a group. The number of ovum was 15 ± 7 in GnRH-ant group and 17 ± 8 in GnRh-a group. Those clinical parameter all reached statistical difference (P < 0.05). The number of embryo was 7 ± 4 in GnRH-ant group and 8 ± 5 in GnRH-a group, the rate of clinical pregnancy was 40.9% (94/230) in GnRH-ant group and 45.6% (216/474) in GnRH-a group, the rate of implantation was 26.1% (128/490) in GnRH-ant group and 30.9% (307/994) in GnRH-a group, the rate of continuing pregnancy was 38.7% (89/230) in GnRH-ant group and 42.6% (202/474)in GnRH-a group, those parameter did not reach statistical difference (P > 0.05). The rate of moderate or severe ovarian hyperstimulation syndrome was 2.4% (6/245) in GnRH-ant group and 4.2% (22/526) in GnRH-a group, which did not show significant difference (P > 0.05). CONCLUSION: In the first IVF or ICSI cycle of the patients with normal ovarian reserve function, the fixed GnRH-ant protocol could get the same satisfied clinical outcome, and it is more economic, convenient and safer compared with low dose depot GnRH-a long protocol.

Asunto(s)

Fertilización In Vitro , Hormona Liberadora de Gonadotropina/agonistas , Hormona Liberadora de Gonadotropina/antagonistas & inhibidores , Infertilidad Femenina/terapia , Inducción de la Ovulación/métodos , Adulto , Gonadotropina Coriónica/administración & dosificación , Gonadotropina Coriónica/uso terapéutico , Protocolos Clínicos , Transferencia de Embrión , Estradiol/sangre , Femenino , Hormona Folículo Estimulante/sangre , Hormona Liberadora de Gonadotropina/administración & dosificación , Gonadotropinas/administración & dosificación , Gonadotropinas/uso terapéutico , Antagonistas de Hormonas/administración & dosificación , Antagonistas de Hormonas/uso terapéutico , Humanos , Síndrome de Hiperestimulación Ovárica/epidemiología , Síndrome de Hiperestimulación Ovárica/prevención & control , Embarazo , Índice de Embarazo , Resultado del Tratamiento

RESUMEN

AIM: Ghrelin is involved in regulating the differentiation of mesoderm-derived precursor cells. The aim of this study was to investigate whether ghrelin modulated the differentiation of human embryonic stem (hES) cells into cardiomyocytes and, if so, whether the effect was mediated by growth hormone secretagogue receptor 1α (GHS-R1α). METHODS: Cardiomyocyte differentiation from hES cells was performed according to an embryoid body (EB)-based protocol. The cumulative percentage of beating EBs was calculated. The expression of cardiac-specific markers including cardiac troponin I (cTnI) and α-myosin heavy chain (α-MHC) was detected using RT-PCR, real-time PCR and Western blot. The dispersed beating EBs were examined using immunofluorescent staining. RESULTS: The percentage of beating EBs and the expression of cTnI were significantly increased after ghrelin (0.1 and 1 nmol/L) added into the differentiation medium. From 6 to 18 d of differentiation, the increased expression of cTnI and α-MHC by ghrelin (1 nmol/L) was time-dependent, and in line with the alteration of the percentages of beating EBs. Furthermore, the dispersed beating EBs were double-positively immunostained with antibodies against cTnI and α-actinin. However, blockage of GHS-R1α with its specific antagonist D-[lys(3)]-GHRP-6 (1 µmol/L) did not alter the effects of ghrelin on cardiomyocyte differentiation. CONCLUSION: Our data show that ghrelin enhances the generation of cardiomyocytes from hES cells, which is not mediated via GHS-R1α.

Asunto(s)

Células Madre Embrionarias/citología , Ghrelina/metabolismo , Miocitos Cardíacos/citología , Receptores de Ghrelina/metabolismo , Diferenciación Celular , Línea Celular , Células Madre Embrionarias/metabolismo , Humanos , Miocitos Cardíacos/metabolismo

RESUMEN

hESCs (human embryonic stem cells) can differentiate into tissue derivatives of all three germ layers in vitro and mimic the development of the embryo in vivo. In this study, we have investigated the potential of an hESC-based assay for the detection of toxicity to cardiac differentiation in embryonic development. First of all, we developed the protocol of cardiac induction from hESCs according to our previous work and distinguished cardiac precursor cells and late mature cardiomyocytes from differentiated cells, demonstrated by the Q-PCR (quantitative real-time PCR), immunocytochemistry and flow cytometry analysis. In order to test whether CPA (cyclophosphamide) induces developmental and cellular toxicity in the human embryo, we exposed the differentiating cells from hESCs to CPA (a well-known proteratogen) at different stages. We have found that a high concentration of CPA could inhibit cardiac differentiation of hESCs. Two separate exposure intervals were used to determine the effects of CPA on cardiac precursor cells and late mature cardiomyocytes respectively. The cardiac precursor cells were sensitive to CPA in non-cytotoxic concentrations for the expression of the cardiac-specific mRNA markers Nkx2.5 (NK2 transcription factor related, locus 5), GATA-4 (GATA binding protein 4 transcription factor) and TNNT2 (troponin T type 2). Non-cytotoxic CPA concentrations did not affect the mRNA markers' expression in late mature cardiomyocytes, indicating that cardiac precursors were more sensitive to CPA than late cardiomyocytes in cardiogenesis. We set up the in vitro developmental toxicity test model so as to reduce the number of test animals and expenses without compromising the safety of consumers and patients. Furthermore, such in vitro methods may be possibly suited to test a large number of chemicals than the classical employed in vivo tests.

Asunto(s)

Antineoplásicos Alquilantes/toxicidad , Diferenciación Celular/efectos de los fármacos , Ciclofosfamida/toxicidad , Células Madre Embrionarias/efectos de los fármacos , Miocitos Cardíacos/efectos de los fármacos , Biomarcadores/metabolismo , Células Madre Embrionarias/citología , Células Madre Embrionarias/metabolismo , Humanos , Miocitos Cardíacos/citología , Miocitos Cardíacos/metabolismo , ARN Mensajero/metabolismo , Reacción en Cadena en Tiempo Real de la Polimerasa , Pruebas de Toxicidad

RESUMEN

In this study a three step culture system, 2D-3D sequential culture in vitro and further implantation in vivo was developed to induce human embryonic stem cells (hESCs) into cartilage like tissues. Five-day-old embryoid bodies were plated for chondrogenic induction for 27 days (step1), then the cells were suspended in alginate and seeded onto polylactic-co-glycolic acid (PLGA) scaffolds for 3D cultivation for 7 days (step 2) and the cells/alginate/PLGA complexes were further transplanted into nude mice for 8 weeks (step 3). At same time, some of complexes were cultured in vitro up to 8 weeks. At the end of step 1, cells exhibited fibroblast-like morphology and expressed chondrocyte-specific markers, Sox 9 and collagen II. During the following 8 weeks of 3D cultivation in vitro, cells displayed spherical morphology, decreased immunoreactivity to Sox-9 and increased one to collagen II, demonstrated further differentiation to mature chondrocyte. In implanted grafts, not only cells appeared typical chondrocytes shape and markers but also cartilage like tissues were formed. These results indicate that 2D-3D sequential culture in vitro is an efficient protocol to induce hESCs differentiates into chondrocytes, while the three step culture system may be an appropriate procedure to derive cartilage like tissues from hESCs.

Asunto(s)

Alginatos/química , Cartílago/fisiología , Técnicas de Cultivo de Célula , Células Madre Embrionarias/fisiología , Ácido Láctico/química , Ácido Poliglicólico/química , Andamios del Tejido/química , Alginatos/metabolismo , Animales , Materiales Biocompatibles/química , Materiales Biocompatibles/metabolismo , Cartílago/citología , Diferenciación Celular , Línea Celular , Condrocitos/citología , Condrocitos/fisiología , Células Madre Embrionarias/citología , Ácido Glucurónico/química , Ácido Glucurónico/metabolismo , Ácidos Hexurónicos/química , Ácidos Hexurónicos/metabolismo , Humanos , Implantes Experimentales , Ácido Láctico/metabolismo , Ensayo de Materiales , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Ácido Poliglicólico/metabolismo , Copolímero de Ácido Poliláctico-Ácido Poliglicólico , Ingeniería de Tejidos/métodos

RESUMEN

Islet-like cells derived from embryonic stem (ES) cells may be a promising therapeutic option for future diabetes treatment. Here, we demonstrated a five-stage protocol with adding exendin-4 instead of nicotinamide finally could generate islet-like cells from human embryonic stem (ES) cells. Immunofluorescence analysis revealed a high percentage of c-peptide positive cells in the derivation. However, in addition to insulin/c-peptide, most cells also coexpressed PDX-1 (pancreas duodenum homeobox-1), glucagon, somatostatin or pancreatic polypeptide. Insulin and other pancreatic beta-cell-specific genes were all present in the differentiated cells. Insulin secretion could be detected and increased significantly by adding KCL in high glucose concentration in vitro. Furthermore, subcutaneous transplantation of scaffolds seeded with the islet-like cells or cell transplantation under kidney capsules for further differentiation in vivo could improve 6h fasted blood glucose levels and diabetic phenotypes in streptozotocin-induced diabetic SCID mice. More interestingly, blood vessels of host origin, characterized by mouse CD31 immunostaining, invaded the cell-scaffold complexes. This work reveals a five-stage protocol with adding exendin-4 may be an effective protocol on the differentiation of human ES cells into islet-like cells, and suggests scaffolds can serve as vehicles for islet-like cell transplantation.

Asunto(s)

Diabetes Mellitus Experimental/complicaciones , Células Madre Embrionarias/citología , Hiperglucemia/complicaciones , Hiperglucemia/terapia , Islotes Pancreáticos/citología , Ácido Láctico/farmacología , Ácido Poliglicólico/farmacología , Andamios del Tejido , Animales , Biomarcadores , Glucemia/efectos de los fármacos , Diferenciación Celular/efectos de los fármacos , Forma de la Célula/efectos de los fármacos , Conducta de Ingestión de Líquido/efectos de los fármacos , Células Madre Embrionarias/efectos de los fármacos , Ayuno/sangre , Conducta Alimentaria/efectos de los fármacos , Técnica del Anticuerpo Fluorescente , Proteínas de Homeodominio/metabolismo , Humanos , Hiperglucemia/sangre , Insulina/metabolismo , Secreción de Insulina , Proteínas de Filamentos Intermediarios/metabolismo , Islotes Pancreáticos/efectos de los fármacos , Islotes Pancreáticos/ultraestructura , Trasplante de Islotes Pancreáticos , Ratones , Proteínas del Tejido Nervioso/metabolismo , Nestina , Copolímero de Ácido Poliláctico-Ácido Poliglicólico , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transactivadores/metabolismo

Asunto(s)

Hiperprolactinemia/diagnóstico , Hiperprolactinemia/terapia , Metrorragia/diagnóstico , Metrorragia/terapia , Diagnóstico Diferencial , Dilatación y Legrado Uterino , Endometrio/patología , Femenino , Humanos , Hiperprolactinemia/etiología , Metrorragia/etiología , Neoplasias Hipofisarias/diagnóstico , Neoplasias Hipofisarias/terapia , Prolactina/sangre

RESUMEN

Based on 9-month consecutive in situ monitoring data, this paper investigated the pollutant sources and loadings of eutrophication in Lichee Lake in Shenzhen. The external source mainly comes from overflow of storm sewer system, which will deteriorate water quality in lake. Total phosphorus concentration was measured with a maximum of 0.347 mg/L after overflow. The sediment release experiment showed that the release rate of total nitrogen during the first week was about 0.036 8 g/(m2 x d), and less release of total phosphorus from sediment into water was measured under aerobic condition. The total phosphorus modeling of each sub-lake for Lichee Lake was developed. The model had a good agreement with 2 groups of monitoring data. And calculation results showed that, it will take 2.18 days subject to 24-hour operations of the integrated treatment project per day to improve water quality in Lake to satisfy the National Standard IV of surface water.

Asunto(s)

Eutrofización , Agua Dulce/análisis , Modelos Teóricos , Fósforo/análisis , Contaminantes Químicos del Agua/análisis , China , Sedimentos Geológicos/química , Contaminación del Agua/análisis , Contaminación del Agua/prevención & control

RESUMEN

Based on 9-month monitoring field data, this paper analyzes the variation of chlorophyll-a (Chl-a), total phosphorus (TP), total nitrogen (TN) and transparency (SD) in different sub-lake districts in order to study the treatment effect of eutrophication restoration project in Lichee Lake in Shenzhen. The statistical results show that, the average of TP and TN for whole lake were below 0.1 mg x L(-1) and 1.5 mg x L(-1) respectively, the average of Chl-a of north lake district and east lake district were 16.77 microg x L(-1) and 21.45 microg x L(-1) respectively, lower than that of south lake district (35.83 microg x L(-1) and west lake district (32.69 microg x L(-1)), and the average of SD for whole lake was greater than 0.5 m. During the 9-month operation of the restoration project, the average water quality satisfied the National Standard IV for surface water and the water was improved from hypereutrophic status to eutrophic status in Lake.

Asunto(s)

Clorofila/análisis , Eutrofización , Agua Dulce/análisis , Contaminantes Químicos del Agua/análisis , China , Clorofila A , Monitoreo del Ambiente , Restauración y Remediación Ambiental , Nitrógeno/análisis , Fósforo/análisis

RESUMEN

OBJECTIVE: To describe the birth achieved from frozen embryos after intracytoplasmic sperm injection (ICSI) of donor sperm into vitrified oocytes. PATIENT: A 25-year-old woman whose husband was azoospermic undergoing IVF therapy. METHODS: Oocytes collected after ovarian stimulation were vitrified, thawed, and fertilized by frozen donor sperm. RESULTS: Nineteen oocytes were vitrified and all survived after thawing. Thirteen of the 19 oocytes that underwent ICSI with donors sperm were successfully fertilized. Twelve embryos were cryopreserved again by conventional slow-freezing protocol because of uterine bleeding on the day of transfer. Three thawed embryos were transferred, and a normal male with an infant karyotype of 46,XY was delivered. CONCLUSION: This case report demonstrates effective oocyte cryopreservation by vitrification.

Asunto(s)

Criopreservación , Oocitos/fisiología , Resultado del Embarazo , Preservación de Semen , Inyecciones de Esperma Intracitoplasmáticas , Adulto , Azoospermia/terapia , Transferencia de Embrión , Femenino , Humanos , Masculino , Embarazo , Donantes de Tejidos