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PubMed2006

[In-vitro differentiation of human testicular round spermatids to elongating spermatids].

OBJECTIVE: To investigate the differentiation of human testicular spermatogenic cells during in vitro culture. METHODS: Testicular cells of obstructive azoospermic patients' testis biopsies were dispersed employing mechanic methods. Then, (1) mixed testicular cells were applied to in vitro culture, and changes of the ratio of elongating spermatids and all round cells were analyzed during mixed cell culture; (2) round spermatids were picked up from the mixed cells employing micromanipulator, followed by differentiation of the isolated round spermatids during microdrop culture. RESULTS: The ratio of the elongating spermatids increased significantly (P < 0.05) after 24 hours of mixed cell culture in HTF medium supplemented with FSH and testosterone. During single round spermatid culture, transformation of the round spermatid to elongating spermatid with newly formed flagellum was observed, and the transformation ratio within 48 hours of microdrop culture was 3.54%. The differentiation of human testicular spermatogenic cells cultured in Vero cell conditioned medium was similar to that cultured in HTF medium. CONCLUSION: Human testicular round spermatids can differentiate to elongating spermatids during in vitro culture. Vero cell conditioned medium does not promote the differentiation of human testicular round spermatids to elongating spermatids.

Animals↗
PubMedDate not supplied

[Biophysical aspects of reconstruction of a single cell by the methods of cell engineering].

The problems of a low efficiency of mammalian cloning are discussed with emphasis on the necessity of the expertise of each step of single cell reconstruction, beginning with microsurgical manipulations. The fact of cell content leakage when the cell is held during microsurgery or microinjections with the help of the conventional method using negative pressure in the holding micropipette was demonstrated in experiments on murine embryos. It was shown that the rate of cell content efflux depends on the value of negative pressure generated in the holding micropipette, and is directly proportional to the dimensions of its orifice and the duration of micromanipulations. An alternative method of cell fixation using the capillary forces of the holding micropipette was proposed. The method optimizes the process of cell fixation, reducing the holding effort by two orders of magnitude. As a result, 92% of embryos remain viable after fixation of embryo, as compared with 39% in the conventional technique. In order to diminish the cell damage produced by the tip of a microinstrument, a new technique of fabricating micropipettes was proposed. The improved method of filling the micropipette with viscous liquids, including DNA, which is described in details in the paper, enabled constant (non-stop) microinjection of more than 1000 cells by hand, without any special automatic device.

Animals↗
PubMed1990

Proliferative potential of murine peritoneal mast cells after degranulation induced by compound 48/80, substance P, tetradecanoylphorbol acetate, or calcium ionophore A23187.

Proliferative potential of degranulated mast cells was investigated. Mast cells were collected from the peritoneal cavity of mice, and degranulation was induced by compound 48/80, substance P, 12-O-tetradecanoylphorbol 13-acetate (TPA), or calcium ionophore A23187. The potentiality of colony formation in methylcellulose was not reduced by treatment of various concentrations of compound 48/80, substance P and TPA. When degranulation was induced by compound 48/80, substance P or TPA, proportion of highly degranulated mast cells containing less than five granules was rather small. In contrast, considerable proportion of highly degranulated mast cells was obtained after the treatment with the low concentration (0.1 microgram/ml) of A23187. These highly degranulated mast cells, which were individually picked up by the micromanipulator, proliferated not only in methylcellulose but also in the skin of mast cell-deficient WBB6F1-W/Wv mice. Inasmuch as we have already shown the proliferation of IgE-sensitized and Ag-stimulated mast cells, degranulated mast cells appear to retain the proliferative potential in general.

Animals↗
PubMed1991

Individual embryonic fibroblasts express multiple beta chains in association with the alpha v integrin subunit. Loss of beta 3 expression with cell confluence.

The alpha chain of the vitronectin receptor, alpha v, has been found in association with the integrin subunits beta 1, beta 3, or beta 5 on different cell types. We show here that cultured embryonic fibroblasts simultaneously display alpha v beta 3, alpha v beta 1, and alpha v in association with two other beta subunits, one of which is probably beta 5. Polymerase chain reaction analysis of single cells isolated by micromanipulation identified mRNA for alpha v, beta 1, beta 3, and beta 5 in six of eight clones. Immunoprecipitation of iodinated cell surface proteins with a monoclonal antibody to alpha v indicated that the relative proportions of the different beta chains in association with alpha v varied, particularly between two different cell lines. The cytokines platelet-derived growth factor, transforming growth factor beta 1, and tumor necrosis factor alpha did not appear to alter this ratio although tumor necrosis factor alpha increased the surface expression of the alpha v-associated integrins; but overnight culture in basic fibroblast growth factor caused a lower expression of alpha v beta 1 and alpha v beta 5 with no reduction in alpha v beta 3 expression. When the cell cultures were grown to complete confluence, surface expression of beta 3 was abolished, and the expression of an unknown beta chain (beta u) became more prominent. This effect was not overcome by culturing confluent cells with basic fibroblast growth factor. Affinity column chromatography showed that alpha v beta 5 bound to vitronectin but alpha v beta 1 did not, whereas alpha v beta 1 but not alpha v beta 5 bound to fibronectin. These results suggest that, on individual cells, the beta subunits found in association with alpha v may vary according to the proliferative capacity of the cell and that the promiscuous beta 3 subunit is progressively replaced by beta subunits of individual ligand specificity.

Base Sequence↗
PubMed1991

[Humoral regulation of stem cell proliferation].

The central feature of hematopoiesis is life-long, stable cell renewal. This process is supported by hemopoietic stem cells which, in the steady state, appear to be dormant in cell cycling. The recruitment of the dormant stem cells into cell cycle may be promoted by such factors as interleukin (IL)-1, IL-6, granulocyte-colony stimulating factor (G-CSF), and newly discovered IL-11. The effects of IL-1 on stem cells may be indirect. Once the stem cells leave Go and begin proliferation, the subsequent process is characterized by continued proliferation and differentiation. Though several models of stem cell differentiation have been proposed, micromanipulation studies of individual progenitors suggest that the commitment of multipotential progenitors to single lineages is a stochastic process. The proliferation of early hemopoietic progenitors requires the presence of IL-3 and/or IL-4, and the intermediate process appears to be supported by granulocyte/macrophage-CSF (GM-CSF). Once the progenitors are committed to individual lineages, the subsequent maturation process appears to be supported by late-acting, lineage-specific factors such as erythropoietin (erythropoiesis), G-CSF (neutrophil production), and IL-5 (eosinophilopoiesis). Thus, hemopoietic proliferation appears to be regulated by a cascade of factors directed at different developmental stages.

Animals↗
PubMed1991

Modern approaches to the treatment of human infertility through assisted reproduction.

Medical statistics from the United States show approximately 15 percent of all couples of reproductive age are unable to conceive naturally. In recent years, the numbers of couples with reproductive problems has increased, principally due to changes in life style and delayed childbearing. Only 13 years after the birth of the first "test tube baby", advances in the field of human reproduction have created a wide range of alternatives to help infertile couples conceive a healthy infant. Together, these techniques are called Assisted Reproductive Technology (ART) and include: in vitro fertilization (IVF), intratubal transfer of gametes (GIFT), intratubal transfer of zygotes (ZIFT), tubal transfer of preimplantation embryos (TET), gamete or embryo donation, cryopreservtion, and micromanipulation. The application of these techniques is presented here. While much remains to be learned, the ability to fertilize ova in vitro and sustain early embryonic life outside the body is now a reality. Contrary to the idea that these techniques create life in vitro, they simply remove barriers caused by different forms of infertility which impede the creation of life. More than 30,000 infants have now been produced world-wide through ART. In the future, new developments in the field of assisted reproduction promise to bring new hope to the growing numbers of infertile couples around the world.

Female↗
PubMed1991

Assisted reproductive technologies for male factor infertility.

Experience in the diagnosis and treatment of infertility has led to an increased understanding of the prominent role male factors play in many couples' inability to conceive. While many forms of male factor infertility are amenable to treatment, for some patients there is no corrective therapy available. For this reason, a great deal of attention has been focused on developing technologies for semen processing and sperm utilization in cases of decreased semen quality. One area of research is the development of more sophisticated methods of assessing sperm function, as well as methods of sperm preparation. Progress is also being made in the application of technologies such as intrauterine insemination and in vitro fertilization in the treatment of male factor infertility. Such developments have improved prospects for fertility among patients suffering from decreased semen quality, as well as those suffering from such disorders as ejaculatory failure and congenital vasal agenesis. Current research also offers promise for future applications such as gamete micromanipulation. This technology holds potential for improving fertility even among patients suffering from profound male factor disorders. The following is a summary of recent publications pertaining to the application of these assisted reproductive technologies in the management of male factor infertility.

Fertilization in Vitro↗
PubMed1991

[Phenotypic and functional analysis of thymic nurse cell (TNC)-lymphocytes].

Thymic nurse cells (TNC) are epithelial cells containing intact T-cells engulfed within membrane-lined vacuoles in their cytoplasm. Since thymic epithelial cells strongly express MHC class I and II antigens, these lymphoid-epithelial complexes have been considered to provide an optimal micro-environment for the process of self-recognition and/or clonal deactivation of thymocytes. The present experiments were designed to further analyze the phenotypical stage of differentiation and the functional properties of intra-TNC lymphocytes (TNC-L) at a single cell level using the chorionallantoic membrane (CAM) assay, which can only be performed in avian species and, thus, presents a unique possibility to circumvent technical problems for the functional study of TNC-L in mammals. In immunofluorescence analyses with monoclonal antibodies (mAb) to the chicken alpha/beta and gamma/delta T cell receptors (TCR) and the CD3, CD4, and CD8 equivalents, an enrichment was found of CD3+/CD4+/CD8-, CD3+/CD4-/CD8+, TCR alpha/beta + and TCR gamma/delta + cells inside TNC, as compared with extra-TNC thymocytes. Assessing micromanipulated, single chicken TNC in the CAM assay, we also demonstrated at a clonal level that TNC-L possess a strong graft-versus-host (GvH) reactivity in allogeneic combinations. This reaction showed morphological, phenotypical and functional characteristics of a classical graft-versus-host reaction (GvHR). The efficiency to induce a GvHR was higher for TNC-L than peripheral blood lymphocytes (PBL) or thymocytes from the same donor. Surprisingly, in syngeneic combinations TNC-L also react against self-MHC molecules with high frequency. The frequency in syngeneic combinations is, however, lower than in allogeneic combinations.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

[In vitro dissection and development of sheep embryos after preservation at very low temperature (-196 degrees C)].

Embryos obtained from Sardinian breed ewes superovulated with FSH-p (Sigma) were frozen at -196 degrees C in liquid nitrogen. After 6 months storage, the embryos (12, all at the compact morula stage), were thawed in a water bath at 39 degrees C for 30 minutes. Six embryos were dissected with a Leitz micromanipulator using a simplified technique. Both demi and intact embryos, were cultured in medium TCM 199 + 10% FCS at 38 degrees C in 5% CO2 for 24 hours. Only five demi-embryos (41.6%) became blastocysts versus 4 whole embryos (66.6%) after the culture period. Splitting as our results show, lowers the embryo viability after freezing-thawing, but it can be used in certain instances to obtain genetic improvement in the Sardinian breed.

Animals↗
PubMed1990

Comparison of persistence of seven bovine viruses on bovine embryos following in vitro exposure.

The ability of seven cytopathic strains of bovine viruses to adhere to the zona pellucida of six-to-eight day-old bovine embryos were compared. Embryos were exposed to virus by placing them either in virus suspensions or by culturing them on infected bovine turbinate cultures for 18-24 h. After exposure to bovine virus diarrhea virus (BVDV), infectious bovine rhinotracheitis virus (IBV), bluetongue virus (BTV), pseudorabies virus (PRV), vesicular stomatitis virus (VSV), parainfluenza 3 virus (PI3), or bovine enterovirus virus (BEV), the embryos were tested for virus by culture in bovine turbinate cells and by morphological examination using electron microscopy (EM). A special technique to minimize loss of embryos processed for EM was developed. More embryos had viral particles on the surface of the zona pellucida after exposure to 18-24 hour infected cell cultures than did embryos exposed to viral culture suspensions. The most dramatic finding was that BTV adhered in large numbers to the surface of the zona pellucida of exposed embryos. IBRV, PRV, and VSV comprised an intermediate group, with virions occasionally detected on the surface of exposed embryos after 5 washes. Therefore, extensive washing is required. The PI3 and BEV were easily removed from embryo-exposed virus by washing. BVD was difficult to identify morphologically, making assessment by EM unreliable. There was no evidence that any one of the seven viruses penetrated the intact zona pellucida. Using a micromanipulator, 42 embryos were also directly inoculated through the zona pellucida with +/- 50 picoliters of virus inoculum or medium.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Cloning of embryos.

Nuclear transfer for the study of differentiation in amphibians has been used since the 1950s, but not until recently have the same procedures been applied successfully to some mammals. Nuclear transfer, as developed for the amphibian, is successful in sheep, cattle, rabbit, and pig, but not mouse embryos. This fact is discussed in relation to the species-specific timing of the activation of the zygotic genome. Nuclear transfer to an oocyte presumably results in a genomic reprogramming of the transferred nucleus. The limits of differentiation that can be reprogrammed have yet to be determined. Since the cells of early embryos are thought to have identical nuclear genomes, early embryos can be used as a source of donor nuclei; and, when combined with serial nuclear transfer, can theoretically produce an unlimited number of identical offspring. Cloning by splitting does not result in a reprogramming of the genome and is limited in the number of identical offspring that can result. Here we discuss some of the factors to consider concerning micromanipulation and nuclear reprogramming and how they relate to other embryo technologies.

Animals↗
PubMed1990

[Medical aspects of diagnosis before implantation].

With the currently available techniques, it is not possible to perform cytogenetic and enzymatic analyses on 1 or 2 cells collected from a human embryo prior to its reimplantation. The recent techniques of polymerase chain reaction may allow DNA analyses in some cases: sexing or diagnosis of monogenic diseases. The reliability of these techniques and the absence of adverse effects due to embryo micromanipulation have to be demonstrated. The practical medical application of preimplantation diagnosis requires in vitro fertilization in a fertile couple and its low rate of success has to be compared to the reliability of the early prenatal diagnosis on chorionic villus samples.

Blastocyst↗
PubMedDate not supplied

[The isoenzyme identification and pathogenic characteristics of clones of Leishmania major, L. sp. nov. and L. gerbilli].

Using Fonbrune's micromanipulators, 16 freshly obtained Leishmania isolates (13 from R. opimus, 1 from P. papatasi, 2 from patients with skin leishmaniasis) have been cloned. 4 out of them were L. major isolates, 5 were L. sp. nov. isolates, 5 were mixed L. major and L. sp. nov. isolates and 1 was L. gerbilli isolate. 316 clones were identified using electrophoresis in polyacrylamide gel by 8 enzymes: PGI, PGM, 6-PGD, MDG, G-6-PGD, ME, ALAT, ASAT--and tested for pathogenic activity on golden hamsters. It has been shown that clones of different Leishmania species are characterized by specific pathogenic activity (L. major, by high and L. sp. nov. and L. gerbilli, by low activity). 9-25% of isolates obtained from R. opimus consisted of L. major-L. sp. nov. clone mixture. The isolates obtained from patients with skin leishmaniasis consisted of L. major clones alone. The rate and nature of changes in Leishmania isolate properties during cultivation in different media and golden hamsters depends on the species clone structure of the isolate.

Animals↗
PubMed1990

Antagonistic and agonistic properties of saccharide moieties in the hemizona assay.

The hemizona assay (HZA) was used to evaluate the effects of different sugars on human sperm-zona pellucida interactions. In each controlled assay, sperm binding from men of known fertility with/without preincubation with different carbohydrate constituents was compared. We used human prophase I oocytes obtained from surgically removed ovaries; these oocytes were stored in salt solution and later bisected by micromanipulation. Preincubation of sperm (1 hour) with fucoidin (1.0 mg/mL) significantly inhibited binding by more than 85% as compared with controls. Similarly, lesser fucoidin concentrations of 0.5, 0.25, and 0.01 mg/mL were markedly inhibitory. In addition, preincubation times of 60, 30, and 15 minutes were not different in their degree of inhibitory effect. On the other hand, preincubation of the hemizonae with fucoidin before HZA inhibited binding by 43% compared with controls. Here, the fucoidin effect was significantly less inhibitory than the sperm preincubation effect of fucoidin. Preincubation of sperm with d-fucose had no measurable effect on binding, whereas d-glucose (1.0 mg/mL) and 1-fucose (1.0 mg/mL) increased binding. These results indicate: (1) that the HZA provides a unique internally controlled homologous bioassay to evaluate the effects of simple and complex carbohydrates on sperm zona interactions; (2) that fucoidin is an immediate (less than 15 minutes) inhibitor of human sperm binding to the human zona pellucida under HZA conditions.

Anticoagulants↗
PubMed1990

Ooplasmic transfusion: prophase germinal vesicle oocytes made developmentally competent by microinjection of metaphase II egg cytoplasm.

Approximately one fourth of all human oocytes collected for in vitro fertilization are of immature origin. Even when these oocytes undergo nuclear maturation, fertilization, and cleavage in vitro, transfer of such embryos rarely results in pregnancy reaching delivery. We hypothesized that human embryos derived from prophase I oocytes were developmentally incompetent because they lacked a factor(s) found in in vivo matured oocytes. Using micromanipulation techniques in monkeys, we removed ooplasm from metaphase II oocytes and injected it into prophase I oocytes. After nuclear maturation, oocytes were transferred to the fallopian tube for fertilization. After ooplasmic transfusion, prophase I oocytes resulted in a delivery rate of 13%. When metaphase II ooplasm was heated or exposed to ribonuclease A before microinjection into prophase I oocytes, it lost effectiveness in conferring developmental competence.

Animals↗
PubMed1990

The influence of oxygen tension, temperature, and hemoglobin concentration on the rheologic properties of sickle erythrocytes.

With the use of micromanipulation techniques, the shear modulus or "rigidity" mu, the recovery time tc, and the unfolding time tf for individual sickle cells have been measured at different oxygen tensions, temperatures, and cell densities. In these experiments, the partial pressure of oxygen was varied from 156 to 40 mm Hg and the temperature was controlled at 25 degrees C or 37 degrees C. Three mean cellular hemoglobin concentrations were studied: 29 g/dL, 33 g/dL, and 46 g/dL. The lighter cells (29 and 33 g/dL) exhibited at most a threefold increase in rigidity as the pO2 was decreased from 156 to 40 mm Hg. At 25 degrees C, the densest cells (46 g/dL) also exhibited a threefold increase. However, at 37 degrees C, the rigidity of these cells increased eightfold between 156 to 40 mm Hg. Compared with normal cells, this gives a rigidity that is 18 times larger. In contrast to the values for mu, the values for tc and tf remained essentially unchanged (within the accuracy of the experiments) for the lighter cells and could not be measured for the densest cells.

Adolescent↗
PubMed1985

Clonal analysis of basophil differentiation in bone marrow cultures from a Down's syndrome patient with megakaryoblastic leukemia.

We present the in vitro differentiation of marrow cells from a patient with Down's syndrome accompanied by megakaryoblastic leukemia into basophils in the presence of phytohemagglutinin-stimulated leukocyte conditioned medium, using a liquid culture and methylcellulose culture system. Identification of basophils was established by metachromatic staining with toluidine blue, transmission electron microscopy, and the presence of histamine. However, these basophils did not release histamine in response to calcium ionophore or chemotactic peptide. Samples from suspension cultures that contained 90% basophils showed chromosomal markers characteristic of leukemic cells (48, XY, +11, +21, t(1;15)) in all examined mitoses. The cellular composition of leukemic colonies grown in methylcellulose culture from single cells was studied using the micromanipulation technique. High plating efficiency and extreme predominance of basophil colonies were observed. In a total 137 cultures, 79 revealed colony growth. Of 59 colonies that were analyzed by cytologic examination, 46 were pure basophil colonies. These basophil colonies showed disperse morphology, similar to that of a normal basophil colony. The clonality of the basophil colonies and skewing of lineage expression were documented from leukemic single-cell cultures. These data showed that leukemic cells have the capacity for differentiation into some lineages that are not expressed in vivo.

Basophils↗
PubMed1988

Generation and functional characterization of T cell lines and clones specific for Schistosoma japonicum egg antigen in humans.

T cell lines specific for Schistosoma japonicum egg Ag were established in vitro from patients with chronic schistosomiasis japonica, and investigated their possible immunopathologic roles by testing lymphokines production and in vitro granuloma formation assay. All lines tested had surface phenotypes of CD3+ CD4+ CD8-, and showed S. japonicum soluble egg Ag (SEA)-specific proliferation requiring HLA-DR-restricted Ag presentation. Of these fractions of SEA separated by gel filtration, Fraction II (m.w. 7,000 to 18,000) and III (m.w. 7,000) induced strong proliferation of T cell lines, whereas fraction I (m.w. 18,000+) failed to induce detectable proliferation to any T cell lines tested. One of the T cell lines was cloned by micromanipulation: two of eight clones responded only to fraction II, and six to both fractions II and III. We observed that four of eight clones tested produced IL-2 in response to SEA, and three of them were able to transfer S. japonicum egg-specific granulomatous hypersensitivity in vitro to an HLA haplo-identical individual without previous schistosome infection. These immunopathologic functions of T cell clones seemed to be activated by at least two distinct epitopes of SEA. Our present observations suggest that at least two distinct CD4+ human T cells, both of which recognize epitopes expressed on SEA molecules of less than 18 kDa, might have critical roles in granulomatous hypersensitivity to eggs of S. japonicum in humans.

Adult↗