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Biomedical subjects

Y Tadir

Publications and source records attributed to Y Tadir.

At least 73 records · Page 4Linked to original sources
PubMed1993

Opening of the mouse zona pellucida by laser without a micromanipulator.

A contact-free laser system is described for ablation of the embryonic mouse zona pellucida using a pulsed excimer 308 nm laser. Effects on further embryonic development were evaluated. Zonae of 8- to 16-cell mouse embryos were either lased (n = 189), zona-drilled with acidified Tyrode's solution (n = 183) or left zona-intact (n = 188). Blastocyst formation (99-100%) was similar in the three groups. Hatching occurred earlier in lased embryos compared to those of the control group. These blastocysts hatched through the laser ablated area. Significantly more embryos were hatching on day 4 in the conventionally drilled group when compared to the laser treated group (50% versus 24% respectively). On day 7 of development, significantly (P < 0.05) more embryos conventionally zona-drilled (37%) were intact than those which were previously laser treated (10%). Abnormal development was also noted in a small group of embryos which were lased just on the outside of the zona in comparison to 1/3 of an embryonic width away from the zona. The current results suggest that apparently precise zona laser ablation with an excimer laser at 308 nm may have potential adverse effects which may only be manifested after a prolonged period of culture past the cavitation stage. However, implantation rates of morphologically normal laser abalated embryos were not impaired when compared to control embryos.

Animals↗
PubMed1993

Exposure of human spermatozoa to the cumulus oophorus results in increased relative force as measured by a 760 nm laser optical trap.

Spermatozoa change their movement characteristics in response to different environmental conditions. To investigate the relative force of spermatozoa exhibiting different motility patterns, a laser optical trap was used. A laser beam at 760 nm was directed through a microscope objective and focused above the spermatozoa to create a three-dimensional optical trap. Spermatozoa were trapped at 300 mW, and laser power was reduced until spermatozoa could escape. The force generated by the flagellar movement was proportional to the laser power at which the spermatozoa escaped from the trap. Three motility patterns were studied: linear, hyperactivated, and cumulus-related. Mean escape power for spermatozoa displaying linear motility was 59.5 +/- 43 mW, for hyperactivated motility 122.3 +/- 67 mW (P < 0.0001) and for cumulus-related motility 200.6 +/- 44.2 mW (P < 0.0001). In this study, we showed that human spermatozoa generated more relative force upon exposure to the cumulus mass. The combination of small-amplitude lateral head displacement and higher relative force may produce a 'drilling' effect which is synergistic with the enzymatic digestion of the cumulus matrix during the fertilization process.

Female↗
PubMed1993

Electrical cutting device for laparoscopic removal of tissue from the abdominal cavity.

The extraction of large tissue masses from the abdominal cavity during laparoscopic surgery is a time-consuming, complicated process. A new prototype instrument is introduced that allows quick laparoscopic removal of fibromas, ovaries, or other tissues from the abdomen. A cylinder with a coning knife at its intra-abdominal end is placed inside the trocar sleeve and is rotated by an electrical micro-engine attached to the trocar. Cylindrical tissue blocks are cut step by step out of the main specimen and removed from the peritoneal cavity through the sleeve with a grasping forceps. Tissue removed is suitable for histologic examination. The principal application is morcellation of fibromas, whereas use in ovarian disease is limited. This new device provides a safe and effective approach inside the abdominal cavity.

Electrosurgery↗
PubMed1992

Cutaneous graft-versus-host-like reaction after paternal lymphocyte immunization for prevention of recurrent abortion.

We have presented an immunocompetent patient who, after paternal lymphocyte immunization, developed a GVH-like skin reaction; she recovered spontaneously. This complication is rarely seen. This was the only case observed in our series of over 70 patients immunized. A similar phenomenon was not reported in a larger series by Carp and colleagues (1). However, the case deserves special attention because this reaction can be life-threatening. Therefore, we suggest that paternal lymphocyte immunization should be recommended only for those patients who have undergone a thorough work-up and in whom all causes, other than immunological, for recurrent abortion have been excluded. Even then, this treatment should be given with utmost caution. In view of the above described complication, we believe that more data are still required to justify offering such a treatment modality on a routine basis.

Abortion, Habitual↗
PubMed1992

The relationship between sperm ultrastructural features and fertilizing capacity in vitro.

OBJECTIVE: To evaluate the relationship between ultramorphological features of the human sperm and its fertilizing capacity in vitro. DESIGN: The study was performed retrospectively. Ultrastructural features were assessed using scanning and transmission electron microscopes in sperm samples of individuals who underwent an in vitro fertilization (IVF) treatment cycle no more than 6 months before the study. SETTING: Institutional clinical care. PATIENTS: Fifty-six infertile couples in whom mechanical infertility was diagnosed in the female partner. Patients were categorized as fertilizing when fertilization of at least 30% of the oocytes occurred (n = 27) and nonfertilizing when none of the oocytes fertilized in at least two consecutive IVF treatment cycles (n = 29). RESULTS: The two groups differed significantly only in ultramorphological parameters of the sperm head and acrosome (head, F(8,36) = 2.8, P less than 0.02; acrosome, F(4,40) = 2.8, P less than 0.04), and especially in the following malformation patterns: hyperelongated head, acrosome deficiency, and acrosome damage. The suggested score based on these findings was able to predict 90% and 76% of the cases with and without fertilizing potential, respectively. CONCLUSION: The ultrastructural morphology of the sperm head components is a key parameter for assessing the sperm fertilizing capacity in vitro.

Adult↗
PubMed1992

Acute decline in renal function as a consequence of ovarian hyperstimulation syndrome.

Two cases of severe ovarian hyperstimulation syndrome following ovulation induction are described, one of them following in vitro fertilization and embryo transfer, and the other after conventional ovarian stimulation. This condition was associated with an acute reversible decline in renal function. The treatment and the possible pathophysiological mechanisms are discussed.

Adult↗
PubMed1991

Thoracoscopic carbon dioxide laser treatment of bullous emphysema.

A new technique of thoracoscopic laser ablation of pulmonary bullae suitable for patients with multiple bullae and diffuse emphysema was developed and assessed in 22 patients. 20 of 22 patients survived. Pre-operative and postoperative functional evaluation is available for the 11 patients followed up for more than a month; at 1 to 3 months postoperatively there were increases in FVC (mean 2.0 litres pre-operatively to 2.7 litres postoperatively, p less than 0.001), in FEV1 (0.74 to 1.06 litres, p = 0.01), and in maximum exercise treadmill times (5.4 min to 8.0 min, p less than 0.01). Postoperative air leaks lasted a mean of 13 days and usually resolved spontaneously. Other complications were bleeding (1 patient) and unilateral acute lung injury (1 patient). These results suggest that selected patients with diffuse emphysema and pulmonary bullae may benefit from thoracoscopic carbon dioxide laser ablation.

Cysts↗
PubMed1991

Thiol status in human sperm.

The passage of spermatozoa along the epididymis is characterized by a gradual stabilization of intracellular organelles mainly through the oxidation of thiol groups. In this study, we examined the relationship between the thiol-disulfide status of human spermatozoa (using a specific fluorescent probe, monobromobimane) and routine semen analysis parameters. Fluorescence intensity was measured by spectrofluorimeter and its frequency distribution within samples, using a fluorescence-activated cell sorter. The mean proportion of reactive thiols SH/(SS + SH) in 29 semen samples was 29.8% +/- 2.5%. When comparing thiol labeling patterns, oligozoospermic samples differed from normozoospermic ones (P less than 0.05). However, within the normozoospermic group, no correlation was found between thiol-labeling patterns and routine sperm parameters or fertilizing capacity in vitro. No difference in thiol labeling patterns was found between "swim-up" and "whole semen" preparations.

Bridged Bicyclo Compounds↗