PubMed Health⌕ Search

Biomedical subjects

M Mahadevan

Publications and source records attributed to M Mahadevan.

33 records · Page 2Linked to original sources
PubMed1987

Evidence for an absence of deleterious effects of ultrasound on human oocytes.

Animal and human data would suggest that ultrasound causes deleterious effects to oocytes during meiosis. We directly compared the fertilization rate and embryonic development following in vitro fertilization and embryo transfer of those oocytes exposed to ultrasound and those not exposed in the same patient. In 39 unscreened patients a combination of laparoscopy and ultrasound was used for oocyte recovery. Laparoscopy was performed first on the most accessible ovary (usually the right) and at least one oocyte was obtained. Ultrasound-guided oocyte recovery was successful in the other inaccessible ovary. To assess how oocytes obtained by ultrasound or laparoscopy related to the pregnancy rate, two groups of patients were evaluated in whom the embryos transferred either had been exposed to ultrasound or had not been. The fertilization and the embryo cleavage rates were not significantly different between the ultrasound-exposed and the unexposed groups. The pregnancy rate was also not significantly different [9 of 49 (18.4%) for ultrasound exposed versus 14 of 74 (18.9%) for unexposed]. There was one early spontaneous abortion in each group. Further analysis of a group of 40 patients, in whom the oocytes were exposed to ultrasound in situ, after the endogenous luteinizing hormone (LH) surge had begun 1-27 hr earlier, revealed that 6 became pregnant (15%). This preliminary study suggests that exposure of human oocytes to ultrasonic waves, either during the different phases of meiosis or after the completion of meiosis, did not significantly influence the developmental potential of the in vitro fertilized embryos.

Chorionic Gonadotropin↗
PubMed1987

Follicular factors, serum estradiol, and outcome of pregnancy following in vitro fertilization and embryo transfer.

Success rate of in vitro fertilization and embryo transfer (IVF-ET) depends upon clinical and laboratory variables. This study compared follicular measurements and serum estradiol (E2) between 23 delivered and 23 nonpregnant controls following IVF-ET. E2, number of large follicles (no.), E2/no. ratio, total diameter of large follicle (TD), and the E2/TD ratio were compared between the two groups and between 23 women who delivered and 10 who aborted. E2 (P = 0.03), E2/no. (P = 0.006), and E2/TD (P = 0.005) were found to differ significantly between delivered and controls and between delivered and those who aborted.

Embryo Transfer↗
PubMed1986

"Ultrasound rescue": a successful alternative form of oocyte recovery in patients with periovarian adhesions.

Oocyte recoveries for in vitro fertilization/embryo transfer were performed in 82 cycles in 73 women. The status of the ovaries was unknown. Laparoscopy was performed and oocytes from accessible follicles aspirated. The remaining follicles were aspirated ultrasonographically. The recovery rates for laparoscopy of accessible follicles and for ultrasonographic recovery from laparoscopically inaccessible follicles were identical. In 26 patients laparoscopy only was performed. One or more oocytes was obtained in 92% of patients. In 56 cycles when laparoscopy was followed by ultrasound, one or more oocytes were recovered in 95% of patients; in 12 of these patients, three of whom achieved pregnancy, the only oocytes were recovered by the ultrasonographic means after laparoscopy had failed. This method provided an alternative to screening laparoscopy and indicated that cycles of controlled hyperstimulation could be performed with a satisfactory expectation of oocyte recovery in women in whom the state of the pelvis was unknown.

Clomiphene↗
PubMed1984

Unexplained infertility and the possibilities of management with in vitro fertilization and embryo transfer.

The aetiology of idiopathic infertility largely appears to lie within the female genital tract. The causes may be related to psychological, hormonal or biological factors that could influence sexual behaviour or function of the cervix, uterus, tubes or ovaries. Carefully controlled prospective studies are needed to evaluate diagnoses and therapy. Management of cases of long-standing idiopathic infertility in an IVF programme is indicated if the pregnancy rates of the programme are greater than 10%, as it will aid in both diagnosing the underlying cause as well as offering a significantly higher chance of pregnancy than either expectancy or other treatments.

Embryo Transfer↗
PubMed1981

Human seminal lectin. II. Properties of a lectin like factor in the human seminal plasma.

A lectin like haemagglutinin (Human Seminal Lectin - HSL) is present in human seminal plasma. Partial purification and characterization of HSL has been achieved. HSL was shown to be almost completely inactivated at 100 degree C within 15 min. HSL was stable within a pH range of 5 to 10 for one hour, was resistant to trypsin, mercaptoethanol and dithiothreitol and has a molecular weight of about 57 000 daltons and an iso-electric point of about 6.8. HSL activity did not depend on either the incubation temperature or on the availability of free divalent cations such as Ca++,Mg++,or Mn++.

Chromatography, Gel↗
PubMed1980

Human seminal lectin. I. Demonstration and association with male infertility.

A lectin-like hemagglutinin, human seminal lectin (HSL), has been demonstrated in human seminal plasma. It appears to be naturally secreted by all parts of the male reproductive system. High HSL activity was associated with infertility. HSL agglutinated erythrocytes from all of the species tested and agglutination was enhanced by trypsinization of erythrocytes. HSL activity was specifically but weakly inhibited by sugars containing a galactose moiety and was sedimentable by ultracentrifugation. As HSL had properties similar to decapacitation factors, it may play a role in fertilization and could be one of the causes of male infertility.

ABO Blood-Group System↗
PubMedDate not supplied

Effect of cryoprotective media and dilution methods on the preservation of human spermatozoa.

Human Sperm Preservation Medium (HSPM) containing 15% glycerol, 0.05 M sucrose and 1% glycine had an equal or better capacity to preserve sperm motility and vitality than egg yolk-citrate medium (ECM) containing 15% glycerol. Insemination of patients with semen frozen in HSPM resulted in a higher pregnancy rate than semen frozen in ECM. Glycerol was superior to dimethyl sulphoxide (DMSO) or ethylene glycol (EG) as a cryoprotectant, although the cryoprotective ability of 7.5% glycerol and 7.5% EG did not differ significantly. Neither the addition temperature nor the method of addition of the media containing glycerol, DMSO or EG had any influence on the sperm cryosurvival. Raffinose (0.025 to 0.05 M) or sucrose (0.05 to 0.1 M) improved cryosurvival of spermatozoa. The pH of HSPM had no significant influence on the cryosurvival of spermatozoa but the optimal pH was 6.5 to 7. Ratios of 1:1, 1:2, 1:3, and 1:4 of diluent to semen did not affect sperm cryosurvival.

Dimethyl Sulfoxide↗
PubMedDate not supplied

Effect of cooling, freezing and thawing rates and storage conditions on preservation of human spermatozoa.

Human spermatozoa was relatively resistant to cooling shock. However, when diluted semen was cooled faster than 10 degrees C per minute from room temperature (RT) to 5 degrees C and rewarmed to RT, percentage motility and percentage alive of spermatozoa decreased when compared to the slower cooling rates (less than 5 degrees C/min). The optimum cooling rate from RT to 5 degrees C resulting in maximum survival of human spermatozoa was found to be 0.5 to 1 degree per minute when cooled from RT to 5 degrees C and subsequently frozen-thawed in liquid nitrogen (LN2). The optimal freezing rate of 10 degrees C per minute, from 5 degrees to -80 degrees C, resulted in higher survival of human spermatozoa than slower (1.1 degrees C/min) or faster (87.1 degrees C/min) freezing rates. Slow thawing in 20 or 35 degrees C air, on a dry bench, resulted in better survival than the other slower or faster thawing methods used. The temperature at which human semen samples were transferred to LN2 significantly influenced spermatozoa survival. Survival was higher when transferred at -30 degrees C or lower when compared with samples transferred at -15 degrees C or higher. However, maximal spermatozoa survival was obtained when the samples were transferred at -80 degrees C or lower. Transfer of human semen from LN2 to -25 to -30 degrees C and storage for 24 hours significantly reduced spermatozoa viability when compared with storage at 196 degrees C or -80 to -85 degrees C. No significant differences were found between storage temperatures of -80 to -85 degrees C and -196 degrees C in the maintenance of spermatozoa viability for up to 90 days.

Cell Survival↗
PubMedDate not supplied

The diagnostic value of in vitro fertilization and embryo transfer.

Besides the well known indications for the use of IVF as a new therapeutic treatment, this technique may also be used as a diagnostic test for infertile couples in whom pregnancy was not achieved by previous treatments. IVF diagnostic test appears to be very reliable in the majority of cases. If the failure of fertilization occurs in the first attempt the test is not reliable; failure of fertilization after three or more attempts allows the patients to consider other options such as adoption or AID.

Adult↗