Biomedical subjects
Publications and source records attributed to Y Tadir.
The first case of limb-body wall complex (a combination of a body wall defect, neural tube defect, and limb abnormalities) after IVF is described. This is the third reported patient with this complex anomaly associated with complete absence of external genitalia. The possible pathogenic mechanisms are discussed.
OBJECTIVE: Assessment of possible effects of ovarian stimulation during in vitro fertilization (IVF) treatment cycles on circulating levels of antiphospholipid and antinuclear autoantibodies. DESIGN: The study was performed prospectively. Sera were obtained at three time points along IVF treatment cycle. Levels of autoantibodies directed against nuclear components, mitochondrial antigens, and phospholipids were determined using enzyme-linked immunosorbent assay. PATIENTS: Thirty-five patients, who underwent at least one previous IVF attempt, and 36 age- and sex-matched controls were analyzed. All participants were randomly selected. RESULTS: The mean levels of antiphospholipid (but not antinuclear) autoantibodies in sera from IVF-treated patients were found to be significantly higher than the corresponding values of the control group (for immunoglobulin [Ig]M isotype: anticardiolipin, antiphosphatidyl L-serine; for IgG isotype: anticardiolipin, antiphosphatidyl L-serine, and antiphosphatidylcholine; P less than 0.0001, assessed by Mann-Whitney test). The autoantibody levels remained more or less constant at different time points along the treatment cycle. No correlation with age and number of previous IVF cycles was demonstrated. CONCLUSIONS: Serum levels of antiphospholipid (but not antinuclear) autoantibodies increase after IVF treatment. Based on these preliminary data, it is not yet possible to estimate if the observed changes in autoantibody levels might have any future clinical influence on infertile patients undergoing IVF treatment.
Various microsurgical procedures at the cellular and subcellular levels using laser non-touch techniques are presented and reviewed. In these procedures, the beams of light, varying in their wavelength (range: 14 ns to continuous wave), were directed via microscopes towards the target area. Micromanipulation of human spermatozoa with a laser-generated optical trap enabled the assessment of possible effects on sperm motility and measurements of the relative force generated by each single spermatozoon. Furthermore, the optical trap also provides a new approach to the measurements of intracellular forces without physically touching the cell or its organelles, and inducing chromosome movement during cell division is also possible. Laser beams in a specific configuration are able to induce minimal superficial damage to the zona pellucida of oocytes from various species. This manipulation is aimed at increasing the fertilization rate following insemination with low-quality spermatozoa. Another intracellular application of the laser beams is the destruction of extra pronuclei in polyspermic fertilized human oocytes. These procedures require special equipment which is not commonly available. However, simpler devices may be developed if the advantages of this novel technology are demonstrated.
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Endometrial laser ablation is one of the alternatives to hysterectomy in cases of intractable uterine bleeding. It is currently performed using the Nd:YAG laser at 1.06 microns. The aim of this study was to compare the tissue effect of three types of laser irradiation (Nd:YAG laser at 1.06 and 1.32 microns and holmium laser at 2.12 microns) on the rabbit endometrium. Crater formation, coagulation necrosis, and muscle necrosis were evaluated at the time of ablation, as well as at 1 week and 4 weeks postablation. The results were assessed by determining the depth and width of the affected portion in the uterine wall (lumen to serosa). It was shown that Nd:YAG laser at 1.32 microns caused more generalized and extended effects as compared with the other laser types examined. Endometrial regeneration was faster after ablation by the Nd:YAG laser at 1.06 microns and the holmium laser than by the Nd:YAG laser at 1.32 microns. The widest range of "ablation energy" (defined as that causing ablation without muscle damage) was achieved by applying the holmium laser. Further evaluation of the holmium laser for this indication is recommended.
The relationship between sperm parameters and fertilizing capacity in vitro was examined retrospectively, with the aim of finding predictive criteria for successful in vitro fertilization. Three hundred thirty semen samples were used to inseminate 1462 oocytes. Conventional parameters of sperm concentration and percentage motility in the ejaculate as well as swim-up migration were analyzed in relation to fertilization rate. It was shown that the probability of fertilizing human oocytes in vitro decreases significantly when (a) the sperm concentration is below 20 x 10(6) spermatozoa/ml ejaculate (P = 0.006), (b) motility is lower than 80% (P = 0.002), or (c) less than 4 x 10(6) motile spermatozoa/ml are concentrated in the swim-up fraction (P less than 0.0001). It was also demonstrated that nonfertilizing sperm could not be distinguished from fertilizing sperm by the conventional criteria but rather by the average concentration of motile spermatozoa in the swim-up fraction [12.5 +/- 1.5 and 22.3 +/- 2.3 x 10(6)/ml for the 0 and the 100% fertilization groups, respectively (mean +/- SE; P less than 0.01)]. Thus, the swim-up migration technique can serve as a predictive test for the in vitro fertilizing capacity of sperm.
Despite the limited data that are available concerning FF physicochemical properties, the following conclusions can be drawn. (1) FF temperature is lower than ovarian stroma and body temperatures. The physiological significance of this gradient is unknown. (2) Follicular size increases exponentially prior to ovulation. The relationship between FF volume and successful IVF outcome is well established. (3) A highly significant association exists between fertilization (but not embryo cleavage) and FF spectrophotometric absorbance at delta optic density of 455 nm. (4) FF behaves as a non-Newtonian fluid--its viscosity changes at different shear rates. Neither FF viscosity nor its refractive index was found to correlate with the presence of oocytes, their maturation grade, or their fertilizing capacity. (5) FF osmolarity is similar to that of the plasma. There is no information linking variations in FF osmolarity to IVF outcome. (6) FF pH is acidic, probably due to acid mucopolysaccharides. It appears that the intact follicle is capable of buffering any carbon dioxide which diffuses through its wall at the time of intraperitoneal insufflation. The transvaginal aspiration technique eliminates any possible effect of exogenous gas on FF pH. (7) Regarding the intact follicle, it was shown that (a) there is a small potential difference across the follicle wall, and (b) intrafollicular pressure remains steady prior to ovulation. This information may shed some light on mechanisms underlying FF formation and ovulation. No experiments relating these properties to IVF outcome have been performed.
The development of the single beam gradient force optical trap has made it possible to manipulate cells solely by laser light. A continuous wave Nd:YAG (1.06 microns) laser beam was directed into a conventional microscope and focused onto the viewing plane by the objective lens. The laser beam power at which human sperm were released from the trap was measured and correlated to the sperm's linear velocity before trapping. The mean trapping power readings for slow, medium, and fast motile sperm were 57, 73, and 84 mW, respectively. The analysis of measurements over the total population demonstrated that zig-zag motile sperm had significantly higher mean power readings when compared with straight motile sperm with similar mean linear velocities. In two cases, specimens required significantly less trapping power when the measurements were repeated 24 hours later.
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In an effort to improve the success rate of the previously described thoracoscopic electrocautery ablation technique of spontaneous pneumothorax, the carbon dioxide laser was evaluated in 12 patients. The recurrent (5 patients) or persistent (7 patients) spontaneous pneumothoraces were caused by rupture of (1) blebs in 6 patients, (2) intrapulmonary apical type II bullae in 3 patients, and (3) diffuse bullous emphysema, type III, in 3. The air leaks were successfully sealed in all but 1 patient with ruptured type II bulla. Surgical specimen from this single failure suggested that the entire inner lining of the bullae must be thermocoagulated. This technical modification led to successful outcome in 2 subsequent cases. With the use of carbon dioxide laser, it was possible to treat not only small blebs but all types of bullae causing spontaneous pneumothorax. Laser thoracoscopy is effective and safe in treating spontaneous pneumothorax.
During the past few years in vitro fertilization (IVF) has become one of the standard infertility treatments. In Israel the unique combination of high motivation for childbirth, an active public health service and a large number of IVF units, has created new attitudes among potential patients. The attitudes of 87 couples applying for IVF treatment; their perception of their chances for success of the treatment and of the factors affecting its success; their conception of this treatment as a factor in solving their problems; their emotional responses; and their attitudes to the alternatives, such as adoption, are reviewed. For most couples the choice of place of treatment was not based on reliable medical considerations. The level of anxiety was higher among the women than among the men. It was correlated with their perception of the chances of success of the treatment, as well as with their comprehension of this success as related to future problems.
The effects of CO2 laser beam delivered through a new laparoscopic probe on rabbit uteri is presented. This device has an outer diameter of 4.9 mm and can be delivered through most of the standard operative laparoscopic accessories. Two probes with miniature zinc selenide lenses of 6.5 mm and 17 mm back focal length attached at the distal end were tested. Through each probe, constant 0.5-second pulses and power levels of 5, 10, and 15 W were applied in three different lens-to-target distances. Measurements of beam spot diameters and microscopic crater characteristics revealed significant differences as a result of minor shifting of lens-target distance. From 7 to 9 mm beyond the focal plane and at power levels of 5 to 10 W, negligible tissue effects could be detected. This was defined as an "optical back-stop" effect. A new application mode using an easily maneuverable probe for cutting and coagulating [focusing/defocusing] effects increases the options available for operative laparoscopy.
A correlation between oocyte maturity, duration of preinsemination interval (PII) and fertilization rate in vitro has been suggested. Therefore, delayed insemination is being widely practised in many IVF centres. The purpose of this study was to investigate prospectively the effect of PII upon the fertilization rate in vitro. A total of 1474 oocytes were inseminated following incubation for between 30 and 540 min. The duration of the PII was determined randomly. It was found that neither fertilization rate (on average 46.9%) nor pregnancy rate (20.4%, calculated per embryo transfer) were affected by PII for any given degree of oocyte-cumulus maturity. The ability to inseminate oocytes at any time (within 9 h following egg collection) to the convenience of the biologist further simplifies the technology of IVF.
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The force generated by the radiation pressure of a low power laser beam induces an optical trap which may be used to manipulate sperm. We studied the effect of the optical trap on sperm motility. A Nd:YAG laser beam was coupled to a conventional microscope and focused into the viewing plane by the objective lens. Sperm were caught in the trap and manipulated by a joy stick controlled motorized stage. After different exposure periods, the velocity and patterns were analysed by a computerized image processor. There were minor changes in sperm velocity when exposed to the trap for 30 seconds or less. A gradual decrease in the mean linear velocity was observed after 45 seconds of exposure. This optical micromanipulator may also be useful for studying the force generated by a single spermatozoa and evaluating the influence of drugs on motility.
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A case of Enterobius (Oxyuris) vermicularis granulomatous disease of the pelvic peritoneum causing pelvic adhesions and infertility is presented and discussed. Since parasitic diseases are common in the developing countries, the infertility team has to bear in mind that a parasitic disease might be the main cause of infertility.