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1.
Ceska Gynekol ; 79(1): 22-8, 2014 Jan.
Artigo em Tcheco | MEDLINE | ID: mdl-24635361

RESUMO

OBJECTIVE: One of causes of male infertility is reduced sperm motility. It turns out that the reduced efficiency of the mitochondrial respiratory activity may play a role in the development of this disorder. The aim of our study was to comprehensively determine mitochondrial respiratory activity of sperm with normal and reduced motility. DESIGN: Prospective study. SETTING: Department of Histology and Embryology, Faculty of Medicine in Pilsen, Charles University in Prague; Department of Physiology, Faculty of Medicine in Pilsen, Charles University in Prague; Institute of Reproductive Medicine and Endocrinology, IVF Centers Prof. Zech, Plzen. METHODS: Ejaculates of 14 men were obtained from IVF Center Prof. Zech, Pilsen. According to the World Health Organization classification, samples were divided into normozoospermatic (n = 7) and asthenozoospermatic(n = 7) groups. Respiratory activity of sperm was measured on two-chamber oxygraph Oroboros. RESULTS: In asthenozoospermatic samples, significantly reduced activity of complex I (p = 0.007) and increased respiration after application of ATP-synthase inhibitor oligomycin (showing increased uncoupled oxidation and phosphorylation, p = 0.046) were found. Inhibition of complex I by rotenone showed that complex I contribution to the total capacity of oxidative phosphorylation of healthy sperm was relatively lower than it is typical for somatic cells. CONCLUSION: In our study, we measured mitochondrial respiratory activity of human sperm, permeabilized by digitonin, by high-resolution oxygraphy, which allows the determination of oxygen consumption from the smallest possible number of germ cells. The study results confirm reduced activity of complex I in asthenozoospermatics and suggest that increased leakage of protons from the mitochondrial matrix, which leads to reduced efficiency of phosphorylating process, could participate in the reduced sperm motility. Better characterization of male germ cells, either completely healthy or with affected motility, will help us to understand better the physiological process of fertilization and also to choose the most viable sperm for infertility treatment by methods of assisted reproduction.


Assuntos
Astenozoospermia/genética , Infertilidade Masculina/etiologia , Mitocôndrias/fisiologia , Motilidade dos Espermatozoides/genética , Espermatozoides/patologia , Adulto , Astenozoospermia/complicações , Astenozoospermia/metabolismo , Humanos , Infertilidade Masculina/genética , Infertilidade Masculina/metabolismo , Masculino , Estudos Prospectivos , Espermatozoides/metabolismo
2.
Ceska Gynekol ; 79(1): 16-21, 2014 Jan.
Artigo em Tcheco | MEDLINE | ID: mdl-24635360

RESUMO

OBJECTIVE: Obesity and overweight negatively affect the ability of women to conceive naturally, contributes to the increased incidence of obstetric complications during pregnancy and affect the outcome of assisted reproduction techniques (ART). The aim of our study was to compare the results of treatment of infertilityin a group of infertile women undergoing ART, depending on the values of BMI and changes in levels of selected hormones and markers of oxidative stress in follicular fluid. DESIGN: Retrospective comparative study. SETTING: Faculty of Medicine in Pilsen, Charles University in Prague; Institute of Reproductive Medicine and Endocrinology, IVF Centers - Prof. Zech, Plzen. METHODS: The studied group consisted of 44 women (mean age of 31.9 years, SD = 4.35) treated for infertility at the Institute of Reproductive Medicine and Endocrinology - IVF Centers Prof. Zech. Women were divided into 2 groups according to BMI (37 women had normal BMI, 7 women were overweight). Prolactin, free T3 and T4 hormone, homocysteine, malondialdehyde, glutathione peroxidase, total antioxidant capacity and total protein were analyzed in the follicular fluid both groups. Only blood free samples were studied after pooling of all FF samples of each patient. RESULTS: We observed significantly lower levels of glutathion peroxidase in the group of overweight women(p = 0.0044). The pregnancy success rate with women with normal BMI and overweight women did not differ significantly from each other (p = 0.4430). CONCLUSION: Our study did not confirm the negative effect of obesity on the results of treatment of infertility, specifical-ly pregnancy rate in a group of infertile women undergoing treatment with assisted reproduction techniques.


Assuntos
Infertilidade Feminina/terapia , Sobrepeso/complicações , Taxa de Gravidez/tendências , Técnicas de Reprodução Assistida , Adulto , Feminino , Humanos , Infertilidade Feminina/complicações , Gravidez , Estudos Retrospectivos
3.
Hum Reprod ; 28(11): 2950-7, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24030587

RESUMO

STUDY QUESTION: Does the storage time of vitrified human blastocysts negatively impact their survival, the implantation potential of embryos or the malformation rate of babies born? SUMMARY ANSWER: There was no evidence that storage times of up to 6 years after vitrification (VIT) had a negative impact on blastocyst survival, the implantation potential of embryos or the malformation rate of babies born. WHAT IS KNOWN ALREADY: Although several thousand children have been born after blastocyst VIT, many aspects of this technique remain to be elucidated. New applications, such as fertility preservation, lead to long storage times of vitrified gametes or embryos but it remains to be determined if these vitrified embryos are stable over time. STUDY DESIGN, SIZE, DURATION: A retrospective study including 603 transfers was conducted between January 2009 and April 2012. Blastocysts were vitrified using a closed system. PARTICIPANTS/MATERIALS, SETTING, METHODS: All patients underwent the transfer of aseptically vitrified/warmed blastocysts in a cryo-cycle. A total of 1077 blastocysts were transferred. Survival rates (SRs), implantation potential, birth rates and characteristics of the children born were evaluated. MAIN RESULTS AND THE ROLE OF CHANCE: We found that the storage of vitrified blastocysts in aseptic conditions neither impaired blastocyst viability (SR after warming during the first year of storage was 83.0% compared with 83.1% after 5-6 years of storage: NS) nor decreased pregnancy rates (clinical pregnancy rate after 1 year of storage was 40.0 versus 38.5% after 6 years: NS). In addition, no increase in the malformation rate over time was observed. LIMITATIONS, REASONS FOR CAUTION: Our study only included the transfer of blastocysts which had been vitrified aseptically (i.e. using a closed system). Therefore, our results might not be applicable to 'open' VIT systems. The long-term follow-up of children born will be necessary to confirm our findings. WIDER IMPLICATIONS OF THE FINDINGS: The results suggest that vitrified human blastocysts can be stored for long periods of time without significant negative consequences for the offspring. Therefore, the method should be of benefit to those patients who need to consider taking measures for fertility preservation. STUDY FUNDING/COMPETING INTEREST(S): No external funding was sought for this study and the authors have no conflict of interest to declare.


Assuntos
Blastocisto/fisiologia , Técnicas de Cultura Embrionária , Implantação do Embrião , Resultado da Gravidez , Criopreservação/métodos , Transferência Embrionária , Feminino , Humanos , Gravidez , Taxa de Gravidez , Estudos Retrospectivos , Fatores de Tempo
4.
J Assist Reprod Genet ; 29(2): 131-5, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22116647

RESUMO

BACKGROUND: To analyze the effects of embryo transfer (ET) quality on clinical pregnancy (CPR) and live birth delivery rates (LBDR). METHODS: In a retrospective study at a single, private infertility center between November 2005 and December 2009 one thousand fifty-five day-3 and day-5 ETs following IVF/ICSI/IMSI were evaluated. We analyzed the impact of an atraumatic ET with a soft catheter (ET 1), after external guidance (ET 2), after probing of the cervix with a stylet (ET 3), or after grasping the portio vaginalis with a tenaculum (ET 4) on CPR and LBDR. RESULTS: The use of external guidance showed a significantly reduced LBDR as compared to an atraumatic ET (26.0% vs. 32.5%). The lowest CPR and LBDR were found in ET 4. The application of stylets in cases of difficult ETs was superior to the use of external guidance. No differences in miscarriages between ET 1-4 were noted. CONCLUSIONS: Besides embryo culture and patient history, the quality of an ET might also have an important impact on pregnancy outcome. Techniques to ensure an atraumatic ET, such as mechanic uterine cavity length measurements, before starting treatment might help identify patients at risk for a difficult ET and lead to modified treatments, such as the primary use of a stylet. Limitation of study: retrospective analysis.


Assuntos
Transferência Embrionária/normas , Fertilização in vitro , Nascido Vivo , Aborto Espontâneo , Adulto , Coeficiente de Natalidade , Transferência Embrionária/métodos , Feminino , Humanos , Gravidez , Estudos Retrospectivos , Injeções de Esperma Intracitoplásmicas/métodos
5.
Ceska Gynekol ; 77(5): 471-6, 2012 Oct.
Artigo em Tcheco | MEDLINE | ID: mdl-23116354

RESUMO

OBJECTIVE: Follicular fluid (FF) provides an important microenvironment for the development of oocytes. The biochemical composition of the FF plays critical role in the oocyte competence. The aim of our study was to compare the levels of selected hormones in FF of infertile women and healthy fertile oocyte donors. DESIGN: Retrospective comparative study. SETTING: Department of Histology and Embryology, Faculty of Medicine in Pilsen, Charles University in Prague; Department of Gynecology and Obstetrics, Charles University and University Hospital in Pilsen; Institute of Reproductive Medicine and Endocrinology, IVF Centers Prof. Zech, Plzen. METHODS: Levels of prolactin, free T3 and free T4 hormones in the FF of 146 women were analyzed. We have analysed FF of 74 infertile patients (mean age 31 years, SD = 4.65) and 72 healthy fertile oocyte donors (mean age 26 years, SD = 4.44). Only blood free samples were studied after pooling of all FF samples each patient. Levels of hormones were determined using ECLIA method (Electro-Chemi-Luminiscent Immunoassay) on the Cobas e411. RESULTS: RESULTS showed statistically significantly higher levels of prolactin (p=0.0006) and free T4 hormone (p=0.0246) in FF of infertile women in comparison to the group of healthy fertile oocyte donors. CONCLUSION: Our study confirms the presence of prolactin and thyroid hormones in FF and it can be suggested that they play a key role in the regulation of reproductive processes. The study of FF from donors and their detailed comparison with infertile patients with various gynaecological causes of infertility has great value for better understanding of regulatory mechanisms of fertility.


Assuntos
Infertilidade Feminina/metabolismo , Oócitos/química , Prolactina/análise , Tiroxina/análise , Tri-Iodotironina/análise , Adulto , Feminino , Líquido Folicular/química , Humanos , Doação de Oócitos
6.
Ceska Gynekol ; 77(6): 543-8, 2012 Dec.
Artigo em Tcheco | MEDLINE | ID: mdl-23521197

RESUMO

OBJECTIVE: Follicular fluid (FF) affects oocyte development and disruption of its homeostasis has a crucial effect on egg developmental potential. The aim of this study was to compare the levels of selected oxidative stress markers in the FF of women with impaired fertility and healthy fertile oocytes donors. DESIGN: A retrospective comparative study. SETTING: Faculty of Medicine in Pilsen, Charles University in Prague; Institute of Reproductive Medicine and Endocrinology, IVF Center Prof. Zech, Pilsen. METHODS: Levels of homocysteine (Hcy), malondialdehyde (MDA), glutathione peroxidase (GPx), total antioxidant capacity (AOK) and total protein (CB) were analyzed in the FF. We have analysed FF of 146 women - 74 infertile patients (mean age 31 years, SD = 4.65) and 72 healthy fertile oocyte donors (mean age 26 years, SD = 4.44). Only blood free samples were studied after pooling of all FF samples each patient. RESULTS: The study showed a statistically significantly higher Hcy levels (p < 0.0001) in the FF of healthy fertile women compared with impaired fertility group both - comparing the two groups regardless the age and in groups of the same age range (for the age group between 20 to 29 years isp = 0.0002, for the age group between 30 to 39 years is p < 0.0001). When divided into above age ranges we found statistically significantly higher levels of MDA in the control group aged 20 to 29 years compared to same age infertile patients (p = 0.0374) and statistically significantly higher AOK in infertile women between 30 to 39 years of age compared to same age control group (p = 0.0458). CONCLUSION: The presence or on the contrary the absence of prooxidant parameters in the FF has an important role in the ability of conception and subsequent embryo development.


Assuntos
Líquido Folicular/metabolismo , Infertilidade Feminina/metabolismo , Estresse Oxidativo , Doadores de Tecidos , Adulto , Antioxidantes/metabolismo , Feminino , Glutationa Peroxidase/metabolismo , Homocisteína/metabolismo , Humanos , Malondialdeído/metabolismo
7.
Folia Biol (Praha) ; 57(4): 162-9, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21978758

RESUMO

Mouse embryonic carcinoma cells (P19 line) were studied for both their survival and developmental potential in the intact cerebellum of B6CBA mice. The P19 cells were cultured and labelled with green fluorescent protein using transfection. Cells were used for transplantation either in the undifferentiated stage or after 3 days of neurodifferentiation induced by retinoic acid. The intracerebellar application was performed in 43 mice: group A (N = 21) received neuroprogenitors and group B (N = 22) received undifferentiated cells. The morphology of transplanted cells within the context of the surrounding cerebellar tissue was evaluated after 3 weeks. Naive P19 cells engrafted and survived in the cerebellum of 7 of the 22 adult mice (survival rate 31.8 %). Neuroprogenitors survived in 13 of the 21 mice (survival rate was 61.9 %). Since the cut-off is P < 0.05, the difference is not statistically significant (P = 0.069). An expansive appearance of the graft was significantly more frequent (P = 0.0047) in naive P19 cells than in neuroprogenitors. In mice in which the grafts did not survive, no marks of grafted cells or only fluorescing detritus were found. In conclusion, this is the first study to track the fate and morphology of embryonic carcinoma cells transplanted into the cerebellum, confirming that neuroprogenitors derived from embryonic carcinoma cells can settle in the host tissue and differentiate according to the surrounding conditions. With further validation, the embryonic carcinoma cells could become a valuable model with which to study the impact of cell therapy on neurodegenerative diseases.


Assuntos
Sobrevivência Celular/fisiologia , Cerebelo/citologia , Neurônios/citologia , Células-Tronco/citologia , Animais , Western Blotting , Diferenciação Celular/fisiologia , Linhagem Celular Tumoral , Transplante de Células , Técnica Indireta de Fluorescência para Anticorpo , Camundongos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transplante de Células-Tronco
8.
Reprod Biomed Online ; 21(6): 776-82, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21050820

RESUMO

The elucidation of the metabolic requirements of human embryos in vivo or in vitro remains, despite being intensively investigated, a work in progress. The adoption of extended embryo culture to the blastocyst stage during the last decade has entailed new challenges. With the increased attention to culture media formulations, more evidence on the sensitivity of embryos to their early environmental conditions is accumulating which might affect phenotype and developmental potential. A retrospective study was conducted that comprised 286 IVF cycles to evaluate the effect of two different culture media on blastocyst development and pregnancy outcome. Embryos were either cultured in a one step or a sequential medium. Higher fertilization rates and augmented blastocyst rates as well as higher implantation rates were observed when embryos were cultured in one step medium (P<0.05). Interestingly, the transfer of two embryos where one embryo was cultured in either medium resulted in a significantly higher rate of twin pregnancies. Although multiple pregnancies should be avoided in assisted reproduction treatment to reduce risks for offspring and mother, this higher frequency of twin pregnancies resulting from the transfer of embryos derived from different culture media suggests that each embryo makes individual demands on its early environment.


Assuntos
Blastocisto/fisiologia , Meios de Cultura/química , Técnicas de Cultura Embrionária/métodos , Desenvolvimento Embrionário/fisiologia , Fertilização in vitro , Feminino , Humanos , Gravidez , Resultado da Gravidez , Estudos Retrospectivos
9.
Reprod Biomed Online ; 19(1): 72-8, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19573294

RESUMO

Although some post-thaw morphological predictors of pregnancy have been investigated in slow freezing of blastocysts, no such data have been published for vitrified and warmed blastocysts. Therefore, a prospective four-part score was applied to vitrified/warmed day-5 embryos to evaluate whether certain morphological parameters could serve as predictors of implantation, pregnancy and live birth. All morulae/blastocysts that were considered to be viable after warming were scored according to a previously unpublished grading system based on re-expansion, hatching (out of an artificial gap in the zona pellucida), extensive cytoplasmic granulation and presence of necrotic foci. Overall, 74% (202/273) of the vitrified concepti were found to be viable after warming. Early blastocysts showed better survival versus extended/hatching blastocysts (P < 0.01). Of the morphological parameters analysed, immediate re-expansion (P < 0.05) and hatching (P < 0.001) were positive predictors of the rates of implantation, pregnancy and live birth. The opposite holds for extensive cytoplasmic granulation (P < 0.05), which was negatively related. Accurate scoring of warmed blastocysts (within the first 2 h) allows for prediction of pregnancy outcome, and thus will help to further reduce the number of transferred embryos.


Assuntos
Coeficiente de Natalidade , Implantação do Embrião , Transferência Embrionária , Taxa de Gravidez , Adulto , Feminino , Temperatura Alta , Humanos , Gravidez
10.
Reprod Biomed Online ; 19(5): 700-7, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20021718

RESUMO

During embryo vitrification, it is advisable that cooling and storage should occur in a carrier device in which there is complete separation of the embryos from liquid nitrogen to ensure asepsis. The consequence of a reduction in the cooling rate resulting from the heat-insulating barrier aseptic devices has to be counteracted by gradually increasing intracellular concentrations of cryoprotectants without inducing a toxic effect. Blastocysts originating from couples with male and/or female factor infertility (group 1) or from oocyte donors (group 2) or from in-vitro matured oocytes (group 3) were gradually exposed to increasing concentrations of dimethylsulphoxide/ethylene glycol (5/5%, 10/10% and 20/20%) before aseptic vitrification using a specially designed carrier (VitriSafe), a modification of the open hemi-straw plug device. A total of 120 aseptic vitrification/warming cycles were performed in group 1, 91 in group 2 and 22 in group 3. Survival rates before embryo transfer, ongoing pregnancy and implantation rates were as follows: for group 1, 73, 43 and 26%; for group 2, 88, 53 and 34%; and for group 3, 69, 50 and 38%, respectively. In spite of reduced cooling rates due to aseptic vitrification conditions, a three-step exposure to cryoprotectant solutions protects the embryos effectively from cryo-injuries and guaranties high survival rates.


Assuntos
Blastocisto/citologia , Criopreservação , Técnicas de Cultura Embrionária , Blastocisto/efeitos dos fármacos , Crioprotetores/farmacologia , Técnicas de Cultura Embrionária/instrumentação , Implantação do Embrião , Transferência Embrionária , Feminino , Humanos , Infertilidade Feminina , Masculino , Gravidez , Taxa de Gravidez , Doadores de Tecidos
12.
Minerva Ginecol ; 67(2): 127-47, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25668422

RESUMO

Conventional controlled ovarian stimulation (cCOS) can cause significant discomfort, including ovarian hyperstimulation syndrome (OHSS). Clearly, management of OHSS and poor responder patients requires new strategies to overcome these problems and facilitate the birth of a healthy child with the fewest stimulation cycles. Several alternative methods have been developed. Non-conventional controlled ovarian stimulation (non-cCOS) is based on low-dose stimulation regimens and is often termed "light", "soft", "mini", "minimal", "mild", "low cost", or "low dose IVF". Non-controlled ovarian stimulation therapies (non-COS) include natural cycle IVF or a mixture between non-controlled and non-cCOS, termed "modified natural IVF" or "antiestrogen/aromatase inhibitor/low dose FSH-cycles", in which cycles are monitored but not controlled. These approaches promise to reduce the physical, emotional, and financial burden of IVF therapy while maintaining acceptable pregnancy rates. Such approaches might reduce the risk of OHSS. However, the overall cost per baby increases due to the higher number of stimulation cycles required, and the inconvenience of ovum pick-up still remains. The primary focus should be to obtain several good quality blastocysts after a single cCOS cycle. Thus, adequate numbers of mature oocytes are mandatory. What is more difficult and expensive for patients: several non-COS/non-cCOS cycles to obtain a baby or a single cCOS cycle with a high probability to obtain more than one child? Classic cCOS using the GnRH agonist long protocol followed by single embryo transfer (SET) at the blastocyst stage and aseptic vitrification of surplus embryos optimizes the IVF outcome. This strategy, combined with outpatient management in the case of OHSS, minimizes inconvenience and risks of OHSS. Accumulation cycles (AC) by repeated COS with subsequent freezing of blastocysts, combined with preimplantation genetic screening (PGS), is a promising new approach for low responders, especially in cases of advanced maternal age (AMA).


Assuntos
Fertilização in vitro/métodos , Síndrome de Hiperestimulação Ovariana/prevenção & controle , Indução da Ovulação/métodos , Blastocisto/metabolismo , Transferência Embrionária/economia , Transferência Embrionária/métodos , Feminino , Fertilização in vitro/economia , Hormônio Liberador de Gonadotropina/administração & dosagem , Humanos , Recém-Nascido , Idade Materna , Síndrome de Hiperestimulação Ovariana/etiologia , Indução da Ovulação/economia , Gravidez , Taxa de Gravidez
13.
Geburtshilfe Frauenheilkd ; 74(10): 928-932, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25364032

RESUMO

Introduction: Diminished ovarian reserve (DOR) has been linked to certain subpopulations and distinct gene polymorphisms. It has even been hypothesized that the AB0 blood group system could be linked to ovarian reserve (OR) as reflected by early follicular phase follicle stimulating hormone (FSH) levels. Although estimation of OR is routinely done using levels of anti-Müllerian hormone (AMH), FSH, estradiol or inhibin B, the diagnostic accuracy of these markers is often limited. The aim of this study was to evaluate whether there is any correlation between IVF patients' AB0 blood group system and ART outcome. Methods: In this retrospective observational single-center study we investigated the outcome of 1889 IVF cycles carried out between 2005 and 2012 with regard to blood type and OR in different age groups (21-36 years and 37-43 years). The number of cumulus oocyte complexes (COCs) and metaphase II oocytes obtained after ovarian stimulation, fertilization rate (FR), pregnancy rate (PR) and birth rate (BR) were evaluated with respect to maternal age (21-36 and 37-43 years, respectively). Results: We found no significant differences in the average number of COCs after ovum pick-up in either of the age groups. Moreover, the mean number of MII oocytes and 2PN stages were similar for all blood type groups. As regards IVF outcome measured in terms of PR and BR, no significant differences were observed between the different blood groups. In conclusion, no correlation was found between blood type and female fertility. Discussion: The most precise definition of OR is determining the number of competent oocytes. Based on the finding of our study, the hypothesis that there is a correlation between OR and AB0 blood group system can be dismissed for Caucasian IVF patients.

14.
Geburtshilfe Frauenheilkd ; 72(8): 716-720, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25258463

RESUMO

Purpose: Aim of the study was to investigate the incidence, progress, management and outcome of adnexal torsion after controlled ovarian hyperstimulation in embryo transfer cycles. Materials and Method: A retrospective analysis was done of 1007 patients of a private IVF centre. The literature on adnexal torsion is reviewed. Results: In the literature, the incidence of adnexal torsion after assisted reproductive technologies (ART) is given as around 0.2 %. A significant increase of up to 33 % has been reported for cases with additional ovarian hyperstimulation syndrome (OHSS) and in pregnant women. In our retrospective analysis of 1007 women (incidence 0.46 %) with 1411 fresh embryo transfer cycles, we found an incidence of 0.35 % per embryo transfer. All adnexal torsions were treated by laparoscopic derotation to preserve fertility. All 5 cases with torsion were pregnant, 2 patients had mild OHSS. We recorded 3 term deliveries, 1 induced abortion for sirenomelia, and 1 missed abortion. Conclusion: Adnexal torsion must be kept in mind after hyperstimulation and embryo transfer, especially when pregnancy or OHSS is also present. With early diagnosis, it should be possible to preserve fertility using laparoscopic derotation.

15.
Cell Biol Int ; 31(5): 489-93, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17198755

RESUMO

Chimeric organisms are commonly generated by injecting stem cells into blastocysts. Embryonic stem cells injected into the blastocoel cavity participate in the further development of the embryo. Adult stem cells have also been used in injection experiments to study their potential plasticity. In this study we focused on the early fate of injected human adult hematopoietic stem cells (HSCs). HSCs were followed immunohistochemically 1-19 h after injection into murine blastocysts. We found that they only rarely attached and integrated into the blastocysts. The high rate of loss of injected cells after prolonged in vitro culture of the chimeras can be explained by apoptosis. Our findings are consistent with previous studies reporting a low rate of integration of adult cells injected to produce chimeric embryos, but this is the first demonstration that the low efficiency of adult stem cell injections into blastocysts is influenced by apoptosis.


Assuntos
Apoptose/fisiologia , Blastocisto/citologia , Caspase 3/metabolismo , Células-Tronco/citologia , Células-Tronco/enzimologia , Adulto , Animais , Parto Obstétrico , Sangue Fetal/citologia , Humanos , Recém-Nascido , Antígenos Comuns de Leucócito/análise , Camundongos , Transplante Heterólogo
16.
Reprod Biomed Online ; 11(3): 355-61, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16176678

RESUMO

Partially or completely hatched blastocysts were obtained from women with at least one previous cycle with failure of implantation. On day 5 after fresh embryo transfers, the remaining vitrification cycles (VC) were divided into three categories according to the types of blastocysts. The first group (20 VC) contained blastocysts (n = 38) with open zona pellucida (ZP), the second group of 34 VC contained blastocysts (n = 100) with both open and intact ZP, while the third group (14 VC) contained blastocysts with intact ZP (n = 39). Blastocysts were exposed to two mixtures of cryoprotectants. At 24 h after warming, survival rates of 82% (31/38), 72% (72/100) and 64% (25/39) were observed in the three groups respectively. Numbers of embryo transfers and blastocysts in the three groups respectively were 20, 31 and 13 transfers, and 31, 60 and 25 blastocysts, resulting in corresponding ongoing pregnancy rates per VC of 35, 26 and 21%. Blastocysts with a larger blastocoelic cavity survived vitrification better when they had partially or completely hatched. Survival rates significantly increased (P < 0.01) from 55 to 81% after warming expanded blastocysts with an intact ZP (n = 42) compared with an open ZP (n = 54) respectively. This study shows that partially or completely hatched blastocysts can be cryopreserved by a simple vitrification procedure using the hemi-straw as embryo carrier.


Assuntos
Blastocisto/fisiologia , Técnicas de Cultura Embrionária , Fertilização in vitro/métodos , Zona Pelúcida/fisiologia , Adulto , Blastocisto/citologia , Criopreservação/métodos , Transferência Embrionária , Feminino , Humanos , Gravidez , Taxa de Gravidez
17.
Reprod Biomed Online ; 10(3): 406-14, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15820055

RESUMO

One of the big question marks in current stem cell research is whether there is true plasticity of adult progenitor cells (APC) or if cell fusion is the principle source of the supposed plasticity. The generation of chimeras by injecting adult progenitor cells into blastocysts is not new. This paper describes an efficient embedding technique for murine blastocysts injected with human APC. This method could help in establishing a novel tool to analyse the process of plasticity, if it truly exists. If this is the case, this technology could be of great help to characterize surface markers of stem cells in great detail. On the other hand, fusion of cells could also be investigated. A system of embedding blastocysts was set up using paraffin for further analysis by means of light microscopy and immunohistochemistry. The embedding of the chimaeras consists of fixing them first with paraformaldehyde in phosphate-buffered saline (PFA/PBS), embedding them in gelatine, fixing the gelatine block with PFA/PBS and finally fixing the gelatine block in a Petri dish by embedding it in paraffin. Using this protocol, the morphology of the blastocysts is well preserved.


Assuntos
Blastocisto/citologia , Inclusão em Parafina/métodos , Células-Tronco Pluripotentes/citologia , Animais , Quimera , Transplante de Células-Tronco Hematopoéticas , Humanos , Técnicas In Vitro , Camundongos , Transplante de Células-Tronco
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