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Cloned mice derived from somatic cell nuclei.

In 1997, a cloned sheep "Dolly" was produced by nuclear transfer of somatic cell. The first birth of cloned mice derived from some somatic cells were succeeded in 1998. At present, it is shown that somatic cells, cumulus cells, fibroblasts and Sertoli cells can be used to the study of cloned animal as nuclear donor. In this study investigation was designed to compare with efficiency on the production of cloned embryos by using the microinjection and the electrofusion methods for nuclear transfer. Oocyte enucleation was performed with a micromanipulator. The oocyte was held by holding pipette, and was enucleated using a beveled pipette. Microinjection method: Cell's nucleus injection was carried out by piezo-micromanipulator. Cytochalasin B treated cumulus cell was aspirated into a injection pipette, and was broken its plasma membrane using the injection pipette. Then, the cumulus cell was injected into the enucleated ooplasm directly. Electrofusion method: The cell was aspirated into a beveled pipette, and then an aspirated cell was inserted into perivitelline space. Then, the pair of enucleated oocyte and cell was fused using electrical cell fusion apparatus. The reconstituted embryos were activated after nuclear transfer using St2+. Reconstituted embryos had been produced by the microinjection showed the embryonic development to over 8-cell stages. But, the rate of fragmentation of reconstituted embryos by the microinjection showed a little high rate in comparison with the electrofusion. When some reconstituted embryos by the microinjection were transplanted to pseudopregnant females' oviduct, 9 fetuses were observed at 14 days post coitum.

Animals↗

Embryo development and establishment of pregnancy after embryo transfer in pigs: coping with limitations in the availability of viable embryos.

Embryo transfer and pregnancy maintenance strategies in pigs were evaluated with reference to situations in which limited numbers of viable embryos or micromanipulated embryos are available, such as pig cloning. Development of embryos with compromised zona pellucida was compared with development of embryos with intact zona pellucida. Micromanipulation had no effect on blastocyst production rates after development in vivo or in vitro, but development in vivo improved the number of embryos reaching the blastocyst stage. Transfer of embryos with compromised zona pellucida resulted in live piglets. Several hormone treatments to maintain pregnancy were tested in a model in which three embryos were transferred into unmated recipient gilts, compared with transfer of three embryos into mated recipients. None of the hormonal treatments resulted in pregnancy rates of more than 25% at term and no more than 9% of transferred embryos survived, in comparison with 50% of the mated recipients successfully carrying 25% of transferred embryos. Lastly, the developmental potential of parthenogenetic embryos was assessed and 62% of transferred embryos resulted in pregnancies, none of which continued beyond day 55 of gestation. After co-transfer of three fertilized embryos with 55-60 parthenogenetic embryos into each of six recipients, two live piglets were delivered. The results from the present study indicate that transfer of zona pellucida compromised embryos can yield litters of normal piglets. In addition, it was demonstrated in a model system involving the transfer of three fertilized embryos into mature gilts that hormonal pregnancy maintenance strategies support a low proportion of embryos to term. Lastly, the present study shows for the first time a comparably effective but novel alternative for pregnancy maintenance in the pig involving the co-transfer of parthenote embryos.

Animals↗

[Identification of the origin of single nucleated red blood cells and free DNA in peripheral blood of pregnant women].

OBJECTIVE: To investigate the feasibility of using single fetal nucleated red blood cells (FNRBCs) and free DNA for noninvasive prenatal diagnosis. METHODS: 116 samples of maternal blood were analyzed. Single FNRBCs were isolated from the peripheral blood samples of 51 pregnant women with the gestational period of 14 to 26 weeks by micromanipulation techniques after density gradient centrifugation. Nested polymerase chain reaction method was used to amplify the SRY gene. Plasma DNA in blood samples of 65 pregnant women with the gestational period of 5 approximately 40 weeks were extracted and primer extension preamplification (PEP) and nested polymerase chain reaction were employed to amplify the SRY gene. Chorionic tissue/amniotic cells were extracted to compare the concordance between the examination result of the meternal blood and that of chorionic tissue/amniotic cells. Venous blood of healthy men and unpregnant women were used as controls. RESULTS: (1) The detection rate of single nucleated red blood cells was 90.20% (46/51). (2) The concordance rate of SRY gene amplification results of single cells with real fetal sex was 82.61% (38/46), the sensitivity rate was 80.00% (24/30), and the specificity rate was 87.50% (14/16). (3) The concordance rate of SRY gene amplification results of free DNA with real fetal sex was 90.77% (59/65), the sensitivity rate was 89.13% (41/46), and the specificity rate was 94.74% (18/19). CONCLUSION: (1) The single nucleated red blood cells and free DNA in maternal blood are of fetal origin and can be one of the valuable material sources for prenatal diagnosis. (2) The detection purity of FNRBC by using micromanipulation techniques is nearly 100% and it provides a new way for noninvasive prenatal diagnosis.

Adult↗

Microrobots for in vitro fertilization applications.

The Micromanipulation and Micro-actuation Research Group at the LAB has activities related to biological and surgical applications. Concerning cells micromanipulation, our laboratory works in collaboration with the research team "Genetic and Reproduction" of the Besançon's hospital (France). The global final objective is the development of an automatic intra cytoplasmic sperm injection (ICSI) device in order to improve performances and ergonomics of current devices. In the future this new device will contain various modules: module for removal of cumulus cells, modules for characterization of oocytes, microinjection module, cells transport system. The first subsystem developed is a new single cell transport system. It consists in a so-called micropusher which pushes single cells without having contact with the external environment. This micropusher is a ferromagnetic particle (from 400 x 400 x 20 microm3 to 100 x 100 x 5 microm3) which follows the movement of a permanent magnet located under the biological medium. A 2D micro-positioning table moves this magnet under the glass slide. The pusher and cells positions are measured through an optical microscope with a CCD camera located above the biological medium. The second subsystem is developed to measure oocytes mechanical stiffness in order to sort them. We have then developed a micro/nano-force sensor based on the diamagnetic levitation principle: a glass tip end-effector (with 20 microm in diameter) is fixed on the equipment which is in levitation (0.5 mm in diameter, 100 mm in length). When a force is applied to the levitated glass tip, it moves to a new equilibrium position. Thanks to themeasurement of this displacement, the applied force can be measured. Since there is no contact and friction between the levitated tip and the fixed part, the resolution of this sensor is very high (10 nN).

Fertilization in Vitro↗

[First attempts of detecting fetal cells in the maternal circulation].

INTRODUCTION: In prenatal diagnosis there is great interest for noninvasive diagnostic methods. Authors report their first results in detecting fetal cells in the maternal circulation during pregnancy. OBJECTIVE: The aim of the study was to detect fetal gender from maternal peripheral blood samples during pregnancy. METHOD: Authors have analysed fetal nucleated red blood cells. In 12 cases after a double density Percoll gradient separation they labelled the surface antigens of the cells with anti-glycophorin-A and anti-CD45 fluorescent antibodies, did an intracellular staining of the epsilon haemoglobin chain, and analysed the cells with flow cytometry. The CD45 negative/glycophorin-A positive/epsilon-haemoglobin chain positive cells were considered as fetal cells. Having the results, in another 13 cases magnetic activated cell sorting with CD71 antibody were used as an enrichment step. Authors made an intracellular staining of the epsilon haemoglobin chain, the positive cells were isolated by micromanipulation, and analysed by single cell fluorescent polymerase chain reaction. Primers for the amelogenin gene were used to detect fetal gender. RESULTS: Only the Percoll enrichment step itself is not enough for using the samples for diagnostic molecular-biologic examinations, a following enrichment step is needed. For this the authors used magnetic activated cell sorting with CD71 antibody. With the help of this enrichment step, after the intracellular staining of the epsilon haemoglobin chain the direct micromanipulator isolation of the epsilon haemoglobin chain positive cells could be done. After analysing single cells by fluorescent polymerase chain reaction, in 8 out of the 11 comparable cases the results were similar to those, what was found during the genetic amniocentesis. In 2 cases from this 8, genetic amniocentesis proved Klinefelter syndrome, which they could also confirm with the examination of fetal cells in the maternal circulation. CONCLUSION: The results of the study suggest that the method described above can be useful in prenatal genetic diagnosis, and improving it could be useful to detect other genetic abnormalities (chromosomal abnormalities, single gene disorders) as well.

Antigens, CD↗

[DNA samples preparation from single cell and its application in sensitivity test].

OBJECTIVE: To establish a reliable, exact and practical method to prepare DNA samples for sensitivity-test purposes. METHODS: The micromanipulation method was employed to prepare exact quantity DNA samples used to study the sensitivity of Profiler Plus Kit-ABI PRISM 310 system. RESULTS: We succeed in establishing a micromanipulation method to prepare groups of DNA samples, which contain 1-11 cells in turn, and also succeed in using them to study the sensitivity of Profiler Plus Kit-ABI310 system. CONCLUSION: The method we have established is proved to be a reliable, exact and practical way to prepare DNA samples for sensitivity-test purposes.

DNA↗

Changes in cell surface antigen expressions during proliferation and differentiation of human erythroid progenitors.

Cell surface antigen expression during proliferation and differentiation of human erythroid progenitors was examined using a combination of sequential micromanipulations of paired daughter cells derived from erythroid burst-forming units (BFU-E) and immuno-staining with a panel of monoclonal antibodies. Single hematopoietic progenitors were identified in methylcellulose cultures containing human cord blood mononuclear cells and micromanipulated individually to secondary culture. Paired daughter cells, granddaughter cells, and subsequent generations, whose counterparts produced erythroid bursts, were stained with various cytochemical and immuno-alkaline phosphatase stainings. Most paired daughter cells of BFU-E immunostained positively with anti-platelet glycoprotein(GP) IIb, antiplatelet GPIIb/IIIa, anti-HLA-DR, and antitransferrin receptor antibodies. Acid phosphatase staining was also positive. Neither CD34 nor CD33 antigens were identified on the cells. CD36 and blood group A antigens were first identified on cells from aggregates containing 32 to 64 cells after 4 days of secondary culture and preceded the expression of glycophorin A and hemoglobin alpha. These results indicate that various cell surface antigens were sequentially expressed during the proliferation and differentiation of erythroid progenitors, and that our procedure may be useful for clarifying the morphologic and immunologic properties of hematopoietic stem cells.

Antibodies, Monoclonal↗

Physics of light and lasers.

Because most laser procedures use the heating effect of the light and given the number of parameters that may be varied--such as power density, power, pulsing, and heating of fiber tips and probes--significant overlap in applications of the various lasers can result. This is readily apparent in the conflicting claims of laser manufacturers seen in promotional materials. Despite this, each type has its strengths. The CO2 laser is a specialty instrument, particularly for microscopic applications in neurosurgery, otolaryngology, and gynecology. Its hemostasis and vaporizing abilities allow its use in dermatology and in general surgery for tumor resection and hemostasis. In gynecology it seems best for colposcopy (cervical and vaginal) and, through a micromanipulator, for laparotomy. The beam is focused and delivered by handpieces and micromanipulators on microscopes. Through the laparoscope, it requires the use of a special laser coupler on a special laser laparoscope to allow for line-of-sight delivery of the beam through the operating channel. Waveguide delivery systems have been introduced for CO2 laser laparoscopy using standard laparoscopes. These function as hollow, slender tubes through which the beam is transmitted by means of hundreds of glancing internal reflections in the tube, which emits the beam at its tip. This eliminates many of the alignment problems of coupler cube-type systems and allows the beam to be delivered close to the target. The Nd:YAG laser is the primary endoscopic instrument in pulmonology, gastroenterology, and urology. The use of contact tips, though not a panacea, increases its applications, particularly in general surgery. Its primary use in gynecology is for endometrial ablation with bare fibers for deep coagulation. Its use for laparoscopy with contact probes or sculpted fibers is quickly growing. Green light lasers (argon and KTP) are color-selective photocoagulators and may be used to cut tissue. They are fiberoptically delivered like the Nd:YAG laser. Their best use in gynecology appears to be a versatile instruments for operative laparoscopy and the simple treatment of endometriosis. A standard quartz fiber with these lasers is usually more versatile than a contact tip with an Nd:YAG laser when used for cutting.

Carbon Dioxide↗

The correlation between sperm cell morphology and fertilization after zona pellucida slitting in subfertile males.

OBJECTIVE: This work was undertaken to evaluate the correlation between sperm cell morphology and fertilization after zona pellucida slitting in subfertile males. DESIGN: Twenty-two couples who failed at least one in vitro fertilization attempt because of lack of oocytes fertilization underwent a zona-slitting micromanipulative procedure. A total of 245 oocytes were retrieved and inseminated by three different modes: 151 oocytes underwent micromanipulation, 2 were damaged, and the remaining 149 inseminated by the husband's sperm (group A). Fifty-five oocytes were not manipulated and inseminated by the husband's sperm (group B), and 39 oocytes were not manipulated and inseminated by a donor sperm (group C). RESULTS: Fertilization rates were 26.8%, 5.5%, and 53.8% in groups A, B, and C, respectively, and differed significantly between group A and group B. The cleavage rates were lower for oocytes fertilized by the husband's sperm (48.6%) than that obtained by donor (90%), suggesting a sperm factor contributing to this phenomenon. The procedure was most efficient in patients with a total motile sperm count after preparation of greater than or equal to 5 million and with either normal sperm morphology or defects localized to the acrosome or tail region only. Sperm with nuclear morphological abnormalities demonstrated a marked reduction in fertilization potential. CONCLUSION: It is concluded that the zona-slitting technique enhances fertilization of severely subfertile sperm, and its efficacy is affected by sperm morphology and a threshold concentration of motile cells.

Animals↗

[In vitro separation and development of sheep blastomeres].

Four cell embryos collected by laparatomy from Sardinian breed ewes superovulated with FSH-p (16 mg Sigma), were divested of their zonae pellucidae (ZP) by micromanipulation or chemical methods (pronase 0.5%, tyrode pH 2.2). The blastomeres were separated by pipetting using a flame polished pasteur pipette in a Ca free medium (PBS. Sigma) and were inserted into previously evacuated Z.P. using a Leitz micromanipulator. The Z.P. were removed either mechanically or with acid tyrode; pronase was unable to digest them after incubation at 30 degrees C for 120 minutes. The single blastomeres were cocultured on a monolayer of ovine oviductal epithelial cells in TCM 199 + 10 FCS at 38 degrees C in 5% CO2 for 60 hours. No developments were observed in blastomeres obtained by acid digestion of the ZP while 50% of the other blastomeres continued their development until the 16 cell stages. Our results suggest that coculture with oviductal epithelial cell monolayers can support in vitro development of single ovine blastomeres.

Animals↗

Clonal proliferation in vitro of individual murine and human hemopoietic cells after fluorescence-activated cell sorting.

A modification of the fluorescence-activated cell sorter (FACS) was used to rapidly and reliably study the clonal proliferation of single hemopoietic cells. Murine FDC-P1 and human cord blood progenitor cells were examined for their ability to proliferate from single cells in 96-well microtiter plates containing agar medium and appropriate stimuli. FACS-sorted FDC-P1 single cells formed colonies in 345 out of 558 wells (62%), which compared favorably with control cultures (53%) and micromanipulated single cells (55%). Similarly, the frequency and type of day-14 colonies arising from cord blood progenitor cells when sorted as single cells by the FACS compared favorably with those grown from micromanipulated single cells or in control cultures.

Animals↗

Phenotypic and functional heterogeneity of human peripheral blood T lymphocytes producing colony stimulating factor. A clonal and precursor frequency analysis.

In this report we describe the precursor frequency and the subset distribution of peripheral blood human T cells producing lymphokine(s) acting on the proliferation and differentiation of bone marrow precursors of the granulocyte/macrophage series, as assessed in a liquid microculture assay. Because the sensitivity of this system was similar to that of the classic colony formation assay in semi-solid (methylcellulose) medium, it is likely that the lymphokine activity measured in this assay corresponds to the colony-stimulating factor (CSF) activity. Single human T lymphocytes, isolated from peripheral blood by E rosetting and Ficoll-Hypaque gradients, were seeded into microculture wells by limiting dilution or micromanipulation techniques and were incubated under culture conditions that allow clonal expansion of essentially all T cells. After 15 to 20 days, microcultures were stimulated with PHA and CSF activity was assayed in culture supernatants 24 hr thereafter. About 45% (1/2.3) of peripheral blood T cells were found to give rise to CSF-producing progenies. Moreover, when fluorescence-activated cell sorter-purified T4+ and T4- (or T8- and T8+) were analyzed, the frequency of the precursors of CSF-producing cells was 1/1.5 in the T4+ subset, whereas approximately one-third of the T8+ cells had this functional potential. To additionally characterize T cells responsible for CSF production, unfractionated T cells as well as T4+ and T4- cells were cloned by single cell micromanipulation. The resulting clones were analyzed simultaneously for the production of IL 2, production of CSF and for cytolytic activity in a lectin-dependent assay. It was found that 25/48 clones obtained from unfractionated T cells produced CSF, whereas 23/48 and 19/48 produced IL 2 or had cytolytic activity respectively. Six of the 25 CSF-producing clones had only this functional capability, whereas the remaining clones in addition displayed cytolytic activity (4/25), IL 2 production (10/25), or both (5/25). A similar functional heterogeneity was observed among T4+ and T4- clones, thus indicating that T cells producing CSF are functionally heterogeneous within both the T4+ and T8+ subsets.

Cell Differentiation↗

Single-cell origin of human mixed hemopoietic colonies expressing various combinations of cell lineages.

We have established single-cell culture for human mixed hemopoietic colonies using a micromanipulator. Mononuclear cells from human umbilical cord blood were cultured at a concentration of 1 X 10(4) cells per milliliter in methylcellulose medium containing medium conditioned by phytohemagglutinin-stimulated leukocytes and erythropoietin. It was possible to identify the single hemopoietic progenitors in situ in methylcellulose culture on the basis of unique morphology and migratory ability after 36 to 60 hours of incubation. Candidate single hemopoietic progenitors from methylcellulose medium were individually micromanipulated to secondary culture dishes and cultured for an additional ten to 14 days. The colonies derived from the single progenitors were individually picked and stained with May-Grünwald-Giemsa for analyses of the cellular composition. A total of 288 single cells were individually transferred to second dishes. Then 186 single cells produced secondary colonies consisting of cells in one to five different lineages. A total of 39 single cells produced mixed hemopoietic colonies consisting of cells in two, three, four, and five different lineages. There were eight types of colonies revealing two different lineages, ie, neutrophil (n)-erythrocyte (E), macrophage (m)-E, m-megakaryocyte (M), eosinophil (e)-basophil (b), eE, bE, bM, and EM lineages. Three types of colonies consisting of cells in three lineages were also seen, ie, nmM, nbE, and ebE. There were six types of colonies consisting of cells in four lineages, ie, nmbM, nmEM, nebE, mebM, and meEM. One type of colony consisted of cells in five different lineages (nmbEM). These results indicate the single-cell origin of human mixed hemopoietic colonies expressing various combinations of cell lineages. It also provides experimental data in support of stochastic mechanisms of stem cell differentiation.

Azure Stains↗

Disparate differentiation in hemopoietic colonies derived from human paired progenitors.

We analyzed the differentiation of hemopoietic colonies derived from human paired daughter cells. Candidate progenitor cells were isolated by use of a micromanipulation technique from cultures of My-10 antigen-positive cord blood cells. Then nine to 36 hours later, the paired daughter cells were separated with a micromanipulator and allowed to form colonies in methylcellulose medium containing erythropoietin, phytohemagglutinin leukocyte-conditioned medium, and platelet-poor plasma. The cellular composition of the colonies was determined by differentiating all of the cells of the May-Grünwald-Giemsa-stained preparation. Of a total of 75 evaluable pairs of colonies, 35 consisted of 28 types of disparate pairs revealing nonhomologous lineage combinations. Forty pairs were homologous in lineage expression. However, the proportions of the individual cell lineages were significantly different in the members of some of the homologous pairs. Some pairs revealed significant differences in colony size. These observations are similar to those reported for murine paired progenitors and are consistent with the stochastic model of human stem cell differentiation.

Basophils↗

Evidence for multipotentiality of antibody synthesizing cells.

Immunization of mice with two unrelated antigens or antigenic determinants regularly results in the appearance of hemolytic plaque forming cells (PFC) of each specificity and of some PFC (1-4%) reacting to both determinants. Micromanipulation of individual double PFC appearing after immunization with trinitrophenyl conjugated sheep erythrocytes (TNP-SRBC) into media containing indicator erythrocytes (native SRBC and TNP-horse RBC) and a soluble specific inhibitor (TNP-BSA or soluble SRBC antigen), showed that the specific inhibitor suppressed the lysis of the corresponding indicator but did not interfered with the lysis of the unrelated indicator. Persistance of one specific activity in spite of complete inhibition of the other indicated that these double PFC synthesize two different antibody molecules. The destiny of double cells was studied in individual cell cultures by micromanipulating them into wells containing heavily irradiated normal mouse spleen cells and both determinants (TNP-SRBC). Those double cells which divided they generated in 24 hours monospecific daughter PFC (either anti-TNP or anti-native SRBC). Individually cultured monospecific PFC from mice immunized with one antigen (native SRBC) generated daughter PFC of the same specificity. By contrast, monospecific PFC from mice immunized with TNP-SRBC generated PFC of either the same specificity of (more frequently) of the one the other specificity. Thus, immunization with substituted erythrocytes resulted in the development of three clonotypes: two clones each composed only of cells of either specificity (amphispecific clonotype). For the maintenance of this amphispecific clone, continuous presence in the culture media of both antigenic determinants was necessary. Removal of the one for 48 hours (but not for 24 hours) abolished the generation of daughter cells of the same specificity.

Animals↗

[Assisted hatching and micro-fertilization].

Erbium-YAG laser has been applied for micromanipulation in human beings. In a first series of attempts it was used in the fertilization process for subzonal insemination (SUZI): laser assisted micromanipulation achieved significant higher fertilization rates (34.8%) when compared to mechanical SUZI (16.1%), and for partial zona dissection (PZD): in this case laser did not improve the results (laser 14.8% vs mechanical 14%). Erbium-YAG laser was used to assist hatching. In the mouse it significantly improved the hatching rate (80% vs 29.3%) 110 hours post hCG. This technique was applied in two different centres to patients with previous IVF failures. The implantation rate per embryo (14.4% laser assisted hatching vs 6% control group) and the pregnancy rate per transfer (40% vs 16.2%) were improved.

Animals↗

Evaluation of sperm function. What is available in the modern andrology laboratory?

Tests of sperm function markedly improve the clinician's ability to diagnose male factor infertility accurately. An understanding of the patient's sperm defect may improve the clinical management of male infertility. A wide spectrum of therapeutic options is available to the urologist treating the infertile male. IVF is now routinely employed for many types of male factor infertility with promising results. Micromanipulation has permitted men who, in the not so distant past, were considered infertile to experience fatherhood. In light of these promising therapeutic advances, accurate assessment of sperm function becomes crucial. Treatment options may be selected on the basis of specific functional defects of sperm. Sperm with an inability to bypass cervical mucus may be adequately treated with IUI. Oligospermic men with sperm capable of ova penetration can be treated with IVF, whereas men whose sperm are incapable of zona binding/penetration may be treated with micromanipulation. Sperm function assays provide a rationale for the selection of specific therapies to treat or bypass identified defects, and by providing comprehensive and accurate diagnosis, they make possible individually tailored therapies. Such individualized treatment choices may improve success rates for many male factor patients.

Cervix Mucus↗

Zona drilling and sperm insertion with combined laser microbeam and optical tweezers.

A combined UV-laser microbeam and optical-tweezers trap was used to perform laser zona drilling and subzonal insemination in cattle. Using a precisely focused UV-laser microbeam, a small channel of about 10 microns in diameter was drilled into the zona pellucida. With a three-dimensional optical-tweezers trap, a single sperm was caught and transported through the laser-drilled hole directly into the perivitelline space. Furthermore, the sperm was brought into close contact with the oolemma to facilitate sperm-oocyte fusion. Using the laser-microscope system, noncontact, entirely sterile, and highly selective micromanipulation of gametes can be achieved with no need for mechanical microtools. Laser micromanipulation seems to be less detrimental to the gametes and is comparatively is easy to perform. Thus, the combined UV-laser microbeam and optical tweezers trap may be a helpful tool for IVF procedures.

Animals↗