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PubMed1988

A simple hydraulic drive for remote control of the Huxley-style micromanipulator.

Electrodeposited metal bellows permit the construction of simple, reliable, and inexpensive hydraulic drives for the Huxley-style micromanipulator. This approach enables precise remote control of micromanipulation without introducing conductive leads or other potential sources of electrical noise near the experimental system. Moreover, the bellows arrangement preserves a stability and reproducibility in the positioning of the heavier transducers that is not matched by other hydraulic micromanipulators. The small size of the hydraulic coupler enables easy installation, and it can be adapted to preexisting manipulators. Importantly, the manipulator's original micrometer control is preserved, a feature that allows the investigator to tailor the apparatus for novel arrangements for micromanipulation.

Electrophysiology↗
PubMed1992

Micromanipulation of cleaved embryos cultured in protein-free medium: a mouse model for assisted hatching.

A mouse model for studying anomalies of human embryonic hatching following micromanipulation is proposed. Initiation and completion of mouse blastocyst hatching was severely impaired (34/292; 12% and 28/292; 10%, respectively) with protein deprivation, resembling the situation in human in vitro fertilization. Hatching ability was restored when an artificial gap was introduced in the zona pellucida by micromanipulation at the cleaved embryo stage. This enabled 77% (285/371) and 36% (134/371) of the embryos to initiate and complete hatching in protein-free medium. No differences were found in overall cell counts between the two groups of embryos. Transfer of micromanipulated blastocysts to pseudopregnant females resulted in development of healthy fetuses.

Animals↗
PubMed1995

Spot size reduction in coupling of laser to micromanipulator in laser microsurgery by fiberoptic link.

BACKGROUND AND OBJECTIVE: In coupling laser with micromanipulator through fiberoptics, the resulting diameter of the spot is limited by the laws of geometrical optics, because of the high numerical aperture (N.A.) of fiberoptic radiation. A new method for the reduction of spot size diameter is suggested. STUDY DESIGN/MATERIALS AND METHODS: The output of a 2 mW He-Ne laser was couped via fiberoptic link, the fiberoptic output light collected by a single lens collimator and directed to the input of the micromanipulator. RESULTS: The spot size can be considerably reduced by the introduction of an aperture which reduces the numerical aperture (N.A.) of the fiberoptic. The resulting reduction in total power has little effect on the power density. CONCLUSION: This approach to the collimator design permits reduction in spot size without any significant changes in power density, thus avoiding damage to the tissue and obtaining optimum performance from the micromanipulator.

Algorithms↗
PubMed1996

Development of a microchamber which spontaneously selects high-quality sperm for use in in vitro fertilization or micromanipulation.

BACKGROUND: A microchamber has been developed which allows motile sperm to swim from a central loading site to peripheral sidewells. The sidewells are designed such that oocytes may be placed within them for in vitro fertilization (IVF) or sperm may be harvested from them for use in standard IVF or micromanipulation. Because only motile sperm can reach the sidewells, the microchamber can select relatively high-quality sperm from a crude preparation. Moreover the steep walls of the sidewells create the potential to trap sperm. OBJECTIVE: The present study was under taken to compare sperm in the sidewells to those found in randomly sampled regions of microchamber after various periods of incubation. RESULTS: We find that the sidewells concentrate motile sperm and that a higher percentage of sperm removed from sidewells is acrosome reacted. Motile sperm from oligospermic patients can be harvested from microchamber sidewells for use in micromanipulation after loading the microchamber with unprocessed specimens. Results suggest that this microchamber could be used to enhance sperm:egg interaction in IVF or to harvest sperm for micromanipulation.

Acrosome↗
PubMed1999

Clinical application of a new assisted hatching method using a piezo-micromanipulator for morphologically low-quality embryos in poor-prognosis infertile patients.

OBJECTIVE: To assess the effect of a assisted hatching technique using a piezo-micromanipulator on pregnancy rates in poor-prognosis infertile patients. DESIGN: A prospective randomized study. SETTING: The Infertility and IVF unit of the Kyoto University Hospital. PATIENT(S): Infertile patients who had been treated for >4 years and failed in previous IVF trials at least twice. INTERVENTION(S): Two hundred forty-eight IVF cycles from 173 patients were divided into two groups: cycles with the transfer of embryos treated by assisted hatching and cycles with the transfer of nontreated embryos. Each group was subdivided into two groups according to embryo morphology: cycles in which three or two morphologically good-quality embryos were transferred and cycles in which one or no morphologically good-quality embryos were transferred. Assisted hatching was performed by a piezo-micromanipulator. MAIN OUTCOME MEASURE(S): The clinical pregnancy rates and implantation rates. RESULT(S): The clinical pregnancy and implantation rates were significantly higher in the assisted hatching group of patients with three or two good-quality embryos than in the other three groups. CONCLUSION(S): The assisted hatching using a piezo-micromanipulator improved the pregnancy and implantation rates in poor-prognosis infertile patients with good-quality embryo transfer but had no effect in patients with low-quality embryo transfer.

Adult↗
PubMed2003

Micromanipulation of the Chlamydia pneumoniae inclusion: implications for cloning and host-pathogen interactions.

The Chlamydia trachomatis inclusion is fragile, rendering it incompatible to micromanipulation. We show that the Chlamydia pneumoniae inclusion differs, being resistant to micromanipulation as shown by direct microinjection of the infected host cytosol or the inclusion itself. We have used micromanipulation to clone C. pneumoniae and to free it from mycoplasma contamination.

Cell Membrane↗
PubMed1994

Rescue of human embryos by micromanipulation.

This chapter evaluates clinical micromanipulation techniques aimed at rescuing abnormally developing zygotes and cleaved embryos. First, the possibility of reversing dispermic zygotes to a normal biparental diploid state was evaluated by extracting the distal pronucleus (that furthest from the polar body). The ratio of X:Y was determined in both groups of embryos by assessing a minimum of two blastomeres using duplex PCR or multiple colour FISH. The ratio of embryos containing only an X chromosome and those with X as well as Y chromosomes in the intact dispermic zygotes was 1.0:2.6, which is similar to the theoretical ratio of 1:3. This ratio was 1.0:1.5 in dispermic zygotes from which the distal pronuclei were removed. Although the ratio of X:Y was altered following removal of distal pronuclei, suggesting frequent targeting of male pronuclei, accidental removal of the female pronucleus could not be excluded. In a second set of mouse experiments, it was shown that the hatching process of embryos that develop with excessive amounts of degenerate material is adversely affected. It was shown that removal of such extracellular material by micromanipulation potentially reverted the hatching process. It was also indicated that immediate removal of the degenerate tissue was more beneficial than that following prolonged co-culture. Assisted hatching is probably the most frequently applied clinical embryo micromanipulation procedure. The outcome of assisted hatching is dependent largely on the mode by which the zona pellucida is breached, the size of the artificial gap and the thickness of the zona pellucida. Embryos with zonae thicker than 17 microns rarely implant. Zona drilling could be detrimental in embryos with thin zonae (< 12 microns). Superficial zona thinning has not enhanced implantation. These observations led to a routine procedure called selective assisted hatching, which involves measuring the zonae before zona drilling and replacement on day 3 of development. This appears to be most successful in older women and those with elevated basal FSH levels. Selective assisted hatching is routinely applied in consenting patients whose embryos have thick zonae, slow development or excessive fragmentation (> 20%). Zona drilling of all embryos, regardless of zona thickness, is being performed in patients aged over 40 years and in those with repeated failures or elevated basal FSH levels. Results in the first group of more than 900 patients indicate that nearly one-quarter of human embryos have the ability to implant.

Animals↗
PubMed1994

[In vitro fertilization in male subfertility--micromanipulation and special techniques for semen preparation].

Poor semen quality is increasingly the reason for human infertility. For couples who cannot be helped by conventional in vitro fertilization (IVF) treatment, micromanipulation methods and special sperm preparation techniques in in vitro fertilization hold considerable promise to enhance fertilization of the egg. "Partial zona dissection" (PZD n = 59) or "subzonal insemination" (SUZI n = 36) were performed in 88 IVF cycles obtaining a fertilization rate between 12.2% and 34.8% depending on the micromanipulation technique applied and a pregnancy rate of 19.2% per embryo transfer. So far ten ongoing pregnancies have occurred and five healthy children have been born. In certain cases of male factor infertility micromanipulation and special sperm preparation techniques therefore represent the only possibility of conceiving.

Adult↗
PubMed2002

NeuRobot: telecontrolled micromanipulator system for minimally invasive microneurosurgery-preliminary results.

OBJECTIVE: Microneurosurgery can be performed less invasively with the recent advances in neuronavigation and neuroendoscopy. For even less invasive microneurosurgery, we have developed a telecontrolled micromanipulator system. METHODS: The NeuRobot telecontrolled micromanipulator system was developed. With the use of this system, surgical simulations were performed with a human cadaveric head. RESULTS: The system consists of four main parts, i.e., a micromanipulator (slave manipulator), a manipulator-supporting device, an operation-input device (master manipulator), and a three-dimensional display monitor. Three 1-mm forceps and a three-dimensional endoscope, which could be remotely controlled with three degrees of freedom (rotation, neck swinging, and forward/backward motion), were installed in the slave manipulator. All surgical procedures were accurately performed with this system. CONCLUSION: The use of telecontrolled manipulator systems in neurosurgery is very promising, and we are convinced that this system will facilitate more accurate, less invasive microneurosurgery. The details of the NeuRobot system and preliminary results are presented.

Cadaver↗
PubMed1991

A compact and stable hydraulic micromanipulator patterned after a Huxley-style approach.

I describe a remote-controlled micromanipulator platform that is stable, durable, precise, and easy to construct. Small metallic bellows are used for hydraulic control, where all fluid connections are made by standard 1/16-in. high-performance liquid chromatography fittings. Inspired by the parallelogram suspension utilized in the larger Huxley-style micromanipulator (A. F. Huxley. J. Physiol. Lond. 157: 6-5P, 1961), the device is a compact cradle suspension of folded lever arms that creates vertical motions which have minimal cross-coupled horizontal error. A simple arrangement for securing the bellows in the remote controller counteracts the vertical cross-coupling error that arises in the parallelogram suspension so that the position of the microtool more faithfully corresponds to the micrometer settings. Being compact, the micromanipulator can be mounted on a microscope stage to eliminate the microscope's resonance as a source of vibration. This feature also reduces the cantilevering of the microtool that 1) is a source of parasitic vibrations and 2) limits the load bearing in larger devices which can only be placed alongside the microscope. The device has a good dynamic response, and one design suits both right- and left-handed use.

Chromatography, High Pressure Liquid↗
PubMed2001

[Correction of polypronuclear zygotes in 31 cases by micromanipulation].

OBJECTIVE: To study the development of polypronuclear zygotes corrected by micromanipulation. METHODS: Thirty one cases of polypronuclear zygotes were corrected during September to December of 1999 through micromanipulation to remove supernumerary pronucleus from polypronuclear zygotes at 37 degrees C and observing their development 24 and 48 hours later to compare with the normal pre-embryos. RESULTS: 17 in 31 (55%) cases of corrected polypronuclear zygotes developed to 2 to 4-cell pre-embryoes 24 hours later. There was significant difference while compare with the normal zygotes. However 48 hours later the cleavage rate of the two group of preembryos was the similar. CONCLUSION: The correction of polypronuclear zygotes by micromanipulation may in some way cause damage to the cleavage ability in part of the zegotes, but the remaining can develope normally.

Cell Division↗
PubMed1992

Advances in clinical micromanipulation of gametes and embryos. Assisted fertilization and hatching.

Several methods for micromanipulation of human gametes have been proposed to enhance fertilization in cases of male infertility. Of these methods, two have been successful in producing pregnancies and live births worldwide; these include partial zona dissection and subzonal sperm insertion. During the period between October 1989 and July 1991, 251 patients with male infertility due to impaired sperm function were treated with in vitro fertilization in conjunction with gamete micromanipulation at our center. Sixty pregnancies (24% per cycle, 42% per replacement) resulted in 144 patients. The details of these treatments are discussed. In another study, in an attempt to increase the incidence of implantation, we have conducted three clinical trials of assisted hatching and selected assisted hatching. The combined results of the trials indicate a clinical pregnancy rate of 51% in the control group and 60% in the micromanipulated group (P less than .05). Moreover, while 20% of the embryos replaced in the control group implanted the implantation rate was increased to 28% in the experimental group (P less than .05). Methodologies and possible implications of these treatments are discussed.

Embryo Implantation↗
PubMed1996

[A micromanipulator for the microscope photometer].

A micromanipulator is described to be designed for micro-operations on cells and for various cytological investigations using microelectrodes especially when cell scanning with inserted microinstrument is required. The baseplate of positioners is a light plate located on the microscope stage immediately. Thus, it is possible to do the following operations: to move the object in the field of vision of the microscope simultaneously with the inserted instrument; to insert several microinstruments into one cell; to make photometry of the cell with the inserted instrument by the scanning method. The positioners bear mechanical micromanipulator which ensures the moving of the instrument in three coordinates (8 mm lengthwise, 3 mm crosswise, and 4 mm in upright position). The micromanipulator can be employed with any type of biological microscopes and makes it possible to use objectives of high magnification (up to 100x). A little weight of the instrument (1 kg) makes it convenient to be used in the expedition.

Animals↗
PubMed1995

Failed fertilization in vitro: second day micromanipulation of oocytes versus reinsemination.

OBJECTIVE: To compare routine reinsemination with 2nd day micromanipulation in patients with poor day 1 fertilization. DESIGN: A retrospective review of patient records. SETTING: The Mount Sinai Medical Center Assisted Reproductive Technologies Program. PARTICIPANTS: Patients undergoing IVF-ET who had poor fertilization (< 35%) with standard insemination and underwent second day reinsemination of oocytes (group I, n = 84) compared with patients who underwent 2nd day micromanipulation with subzonal insemination (group II, n = 12). MAIN OUTCOME MEASURES: Fertilization rate, cleavage rate, number of embryo transfers, and pregnancy rate. RESULTS: Fertilization rate and cleavage rate were significantly higher in group II patients. Pregnancies per transfer were similar between groups I (3/21, 14.3%) and II (0/9, 0%). Second day fertilization was possible in 9 of 12 group II patients, and fertilization rate was higher than day 1 in all nine, however, only 50% achieved cleavage, and none achieved pregnancy. CONCLUSIONS: Although micromanipulating oocytes that fail to fertilize may identify occult male factor infertility, may help the clinician plan future cycles, and may result in fertilization and even transfer of embryos in some cycles, there were no pregnancies in our series, and, for now, the clinical efficacy of this procedure remains in question.

Cleavage Stage, Ovum↗
PubMed1992

Micromanipulation of adhesion of a Jurkat cell to a planar bilayer membrane containing lymphocyte function-associated antigen 3 molecules.

Cell adhesion plays a fundamental role in the organization of cells in differentiated organs, cell motility, and immune response. A novel micromanipulation method is employed to quantify the direct contribution of surface adhesion receptors to the physical strength of cell adhesion. In this technique, a cell is brought into contact with a glass-supported planar membrane reconstituted with a known concentration of a given type of adhesion molecules. After a period of incubation (5-10 min), the cell is detached from the planar bilayer by pulling away the pipette holding the cell in the direction perpendicular to the glass-supported planar bilayer. In particular, we investigated the adhesion between a Jurkat cell expressing CD2 and a glass-supported planar bilayer containing either the glycosyl-phosphatidylinositol (GPI) or the transmembrane (TM) isoform of the counter-receptor lymphocyte function-associated antigen 3 (LFA-3) at a concentration of 1,000 molecules/microns 2. In response to the pipette force the Jurkat cells that adhered to the planar bilayer containing the GPI isoform of LFA-3 underwent extensive elongation. When the contact radius was reduced by approximately 50%, the cell then detached quickly from its substrate. The aspiration pressure required to detach a Jurkat cell from its substrate was comparable to that required to detach a cytotoxic T cell from its target cell. Jurkat cells that had been separated from the substrate again adhered strongly to the planar bilayer when brought to proximity by micromanipulation. In experiments using the planar bilayer containing the TM isoform of LFA-3, Jurkat cells detached with little resistance to micromanipulation and without changing their round shape.

Antigens, CD↗
PubMed1987

Production of identical twin rabbits by micromanipulation of embryos.

The research was conducted to improve micromanipulation procedures with rabbit embryos, including the production of genetically identical progeny. In the first experiment, embryos in different stages of development were used for micromanipulation by removing half of the blastomeres with a beveled aspirating pipette. Embryos 74-78 h postovulatory, in the late compacted morula or early blastocyst stage, were demonstrated to be best for micromanipulation. When embryos at this stage were halved, 77% (64/83) developed into blastocysts compared to 78% (65/83) for the intact control. In the second experiment, the survival of demi-embryos in original versus foreign zonae was tested. Young born from the demi-embryos transferred within original zonae (33%) were not significantly different (p greater than 0.05) from those transferred in foreign zonae (24%). Significantly more offspring, however, were obtained from intact control embryos (58%, p less than 0.01). In the third experiment, identical monozygotic twins were produced from Day 3 embryos, after modification of the aspirating pipette by further sharpening it to a fine point with a microforge. Thirty-four percent young (11) were obtained after microsurgery compared to 36% for intact control embryos transferred. Among the demi-embryos, a pair of albino and a pair of Dutch-belted young were identical twins.

Animals↗
PubMed1998

[Percutaneous sperm retrieval for ICSI procedures in men with obstructive azoospermia: ICSI-PESA and ICSI-TESE micromanipulation: our experience].

OBJECTIVES: The sperm retrieval for ICSI procedures is possibly using following procedures: ejaculate sperm, epididymal sperm obtained by microsurgical aspiration or percutaneous puncture and testicular sperm that are obtained by surgical excision or percutaneous biopsy. Percutaneous techniques seem to be rather simple and effective procedures. DESIGN: The authors present their own experiences with percutaneous sperm retrieval for micromanipulation ICSI from the epididymis (ICSI-PESA) and from the testicular tissue (ICSI-TESE) in men with obstructive azoospermia and with reactive impotence. First time in Poland ICSI-PESA was done on April 11, 1996 in Private Infertility Center "Novum", Warsaw. MATERIAL AND METHODS: From April 1996 to the end of January 1998, 10 ICSI-PESA procedures (in 9 couples) and 8 ICSI-TESE (in 6 couples) were performed. In one case ICSI-PESA was performed in man with psychological inability of masturbation during his wife's IVF protocol. All procedures were performed as the day case urology, under general anesthesia. The fine needles No 6 in PESA or biopsy needle from Hepafix Set B. Braun in TESE were used. The therapy of antibiotic and common analgesic drug was used routinely after puncture. RESULTS: The effectiveness of obtaining sperm for micromanipulation were 100% ICSI-PESA and 75% ICSI-TESE. The pregnancy rate in PESA was 50% and 5 healthy children were born. In TESE only 1 woman (17%) was pregnant, but early spontaneous miscarriage was reported. No surgical and anesthesiological complications were noticed. CONCLUSIONS: Obtaining sperm for micromanipulation ICSI using percutaneous epididymal puncture or testicular tissue needle biopsy seems to be effective and safe for patients with obstructive azoospermia or reactive impotence.

Arterial Occlusive Diseases↗
PubMed1998

Contributions of blastocyst micromanipulation to the study of mammalian development.

This is a personal account of why the author chose to focus on devising techniques for micromanipulating the blastocyst stage conceptus as a way of investigating early development in mammals. Its aim is to provide insight into what such technical innovations entailed and how they have contributed to present understanding of both embryology and the analysis of gene function in mammals. The ability to dissect and reconstitute mouse blastocysts, and to inject cells or tissue into them, enabled genes to be harnessed as markers for elucidating the lineage of cells and interactions between tissues from the stage when differentiation is first evident. Most importantly, it made it possible to apply clonal analysis to the study of cell fate in mammals. The scope of blastocyst micromanipulation was further enhanced when embryonal carcinoma (EC) cells and, particularly, embryonic stem (ES) cells were found to be able to participate in normal development and contribute to the germ line following injection into the blastocyst.

Animals↗