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Biomedical subjects

M Camus

Publications and source records attributed to M Camus.

At least 145 records · Page 8Linked to original sources

Perurethral ultrasound-guided ovum pickup.

Either a percutaneous-transvesical, a transvaginal, or a perurethral-transvesical approach can be used for oocyte recovery under ultrasound guidance in an in vitro fertilization and embryo transfer program. After having experienced these three different approaches in our program, we preferentially used the perurethral-transvesical approach as our routine technique for oocyte recovery under ultrasound guidance. We feel that this method is easier to perform and also carries less risk for contamination. From January to December 1986, 186 oocyte retrievals under ultrasound guidance were performed. In 7 cases no oocytes were found despite normal ovarian stimulation. A total of 767 oocytes was collected; the fertilization rate was 71.8%. Forty pregnancies were achieved (21.5% per attempt or 27.7% per embryo replacement). Except for transient hematuria, no complications were observed.

Chorionic Gonadotropin↗

Inhibition of gonadotropic and ovarian function by intranasal administration of D-Ser (TBU)6-EA10-LHRH in normo-ovulatory women and patients with polycystic ovary disease.

We investigated the effectiveness of D-Ser (TBU)6-EA10-LHRH (Buserelin) intranasally 600 micrograms/day given 6 times daily in desensitizing normal ovulatory women and patients with polycystic ovarian disease (PCOD) before initiation of ovarian stimulation for in vitro fertilization. We found that this regimen was sufficient to suppress the gonadotrophs in the normal women and in 8 out of 10 PCOD patients. In PCOD ovarian hormones became normal after Buserelin administration. Adrenal steroidogenesis was not affected by the GnRH agonist. We suggested that the frequency of administration of Buserelin was important to achieve a constant receptor binding and consequently a rapid desensitization. The choice of a monoclonal immunoradiometric assay for luteinizing hormone (LH) and follicle stimulating hormone (FSH) in association with the estradiol-benzoate provocation test were essential in evaluating desensitization.

Administration, Intranasal↗

Success rate in gamete intrafallopian transfer using low and high concentrations of washed spermatozoa.

The effect of a reduced number of spermatozoa on pregnancies and miscarriages was studied retrospectively in 307 consecutive gamete intrafallopian transfer (GIFT) cycles. The number of spermatozoa introduced per GIFT in each group was as follows: 100,000 (group I), 50,000 (group II), 10,000 (group III), 5,000 (group IV), and 2,500 (group V), which gave a pregnancy rate of 20%, 38%, 37%, 30%, and 24%, respectively (differences were not significant). With respect to the pregnancies, no correlation was found between the number of spermatozoa transferred and the cause of infertility. In the male factor group also no significant difference was observed in the pregnancy rate when the sperms were reduced from 100,000 to 2,500. Lowering the number of sperms in GIFT did not reduce the abortion rate, which remained around 33%. It was the patients with unexplained infertility who benefited most from the GIFT procedure. Their pregnancy rate was significantly higher than the pregnancy rate of those who had endometriosis, or andrologic or immunologic disorders.

Adult↗

Occupational and residential 60-Hz electromagnetic fields and high-frequency electric transients: exposure assessment using a new dosimeter.

One problem that has limited past epidemiologic studies of cancer and exposure to extremely low-frequency (0-100 Hz) electric and magnetic fields has been the lack of adequate methods for assessing personal exposure to these fields. A new 60-Hz electromagnetic field dosimeter was tested to assess occupational and residential exposures of a group of electrical utility workers and a comparison background group over a 7-day period. Comparing work periods only, utility workers' exposures were significantly higher than background levels by a factor of about 10 for electric (E) and magnetic (B) fields and by a factor of 171 for high-frequency transient electric (HFTE) fields. When overall weekly time-weighted averages combining work and nonwork exposures were compared, ratios of the exposed to background groups were lower. B and HFTE exposure ratios remained statistically significant, with values of 3.5 and 58, respectively, whereas the electric field exposure ratio was no longer significant, with a value of 1.7. E-field exposures of the background group were the highest during the nonwork period, probably reflecting the use of electrical appliances at home. Residential E- and B-field exposures were in the same range as published results from other surveys, whereas occupational E-field exposures tended to be lower than exposures reported in other studies. The high variability associated with occupational exposures probably accounts for the latter discrepancy. Worker acceptance of wearing the dosimeter was good: 95% of participants found it to be of little or no inconvenience while at work. At home, 37% found the device to be inconvenient in its present form but would not object to wearing a slightly smaller and lighter dosimeter.

Electricity↗

Hormonal monitoring for in-vitro fertilization and related procedures.

Details of the endocrine monitoring of patients during in-vitro fertilization are analysed. Hormones usually measured are 17 beta-oestradiol, FSH, LH, progesterone and HCG. The assays must be rapid, robust, and have satisfactory precision and reproducibility. Radioimmunoassays have become standardized but immunoradiometric assays are being introduced, where the antibodies can be more easily labelled than antigens, but need care with very high concentrations of antigen. Enzyme immunoassays also have advantages: they are less hazardous than radioimmunoassays and the labelled materials have longer shelf-lives. Chemiluminescence has also been introduced, together with time-resolved fluoroimmunoassays, representing simpler, perhaps cheaper and improved methods. Immunoassays by latex particle counting offer the advantage of being completely automated. Practical examples of these methods are given with details of the treatment of individual patients.

Chorionic Gonadotropin↗

Addition of Buserelin to human menopausal gonadotrophins in patients with failed stimulations for IVF or GIFT.

The combined therapy of a gonadotrophin-releasing hormone agonist (GnRHa) D-Ser(TBU)6-EA10-LHRH (Buserelin) and human menopausal gonadotrophins (HMG) for ovarian stimulation for in-vitro fertilization and gamete intra-Fallopian transfer was evaluated during 84 cycles. All women selected for this therapy had previously failed stimulations with clomiphene citrate/HMG. The GnRHa prevented spontaneous luteinizing hormone surges and premature luteinization in all patients. After addition of the agonist to HMG, the cancellation rate dropped from 17 to 7% and improved the results in 72.6% of the cycles. Twenty-six per cent of the started cycles resulted in a pregnancy. Eighteen healthy children were born at term.

Buserelin↗

Hyperstimulation: the need for cryopreservation of embryos.

Successful application of in-vitro fertilization (IVF), zygote intra-Fallopian transfer (ZIFT) and gamete intra-Fallopian transfer (GIFT) requires ovarian hyperstimulation for the maturation of multiple follicles. To control the risk of multiple pregnancies, the number of gametes (GIFT) or embryos (IVF, ZIFT) replaced is limited to three. For the supernumerary embryos resulting from IVF, ZIFT or GIFT, the strategy is cryopreservation for a later transfer. Cryopreservation was performed using either dimethylsulphoxide or 1,2-propanediol as a cryoprotective agent. Embryos were frozen either in the pronucleate stage with 1,2-propanediol or in the multicellular stage with dimethylsulphoxide or 1,2-propanediol. Survival after thawing was scored for both cryoprotective agents as a function of the developmental stage of the embryo and the embryonic quality. Evaluation of survival after thawing was performed on the basis of morphological intactness of the 1-cell pronucleate embryo or of the blastomeres of multicellular embryos. For pronucleate stage embryos, the use of 1,2-propanediol resulted in a 60% survival after thawing. For 2-cell stage embryos the survival was similar for dimethylsulphoxide and 1,2-propanediol. Later stage embryos survived better when dimethylsulphoxide was the cryoprotectant. For all stages, embryo quality before freezing was a crucial factor in survival after thawing. The pregnancy rate (12.2%) was similar for the two cryopreservation protocols. In conclusion, the choice of an appropriate cryoprotective agent can increase the survival after thawing when embryos are of good quality before freezing.

Cryoprotective Agents↗

Embryo donation in patients with primary ovarian failure.

Thirty-six infertile patients with primary ovarian failure, who were referred for oocyte (embryo) donation are reported. After substitution therapy with oestradiol valerate (per os) and progesterone (i.m. or per os), endometrial tissue was made receptive for embryonic implantation, although the endometrial biopsies on day 21 demonstrated a certain delay in development (of 1.6-2.4 days). Six patients became pregnant, three of them delivered four healthy babies, one pregnancy is progressing normally and two ended in an early clinical abortion.

Chromosome Aberrations↗

In-vitro fertilization with husband and donor sperm in patients with previous fertilization failures using husband sperm.

When previous attempts at in-vitro fertilization using semen from the husband failed, a subsequent IVF attempt was performed using husband and donor sperm in order to compare fertilization and embryo formation after insemination with husband and donor sperm of the same oocyte population. Significantly more eggs were fertilized in patients suffering from andrological and idiopathic infertility when donor sperm were used. No differences were seen in patients with tubal infertility. In the andrological group, the embryos fertilized by the husband showed significantly more fragmentation. No pregnancies were established when husband-fertilized oocytes (embryos) were replaced in the andrological and idiopathic infertility group. This study suggested that an IVF trial using husband and donor sperm might be indicated in couples suffering from andrological or idiopathic infertility in whom no fertilization occurred in a previous cycle using sperm from the husband.

Adult↗

The luteal phase after in-vitro fertilization and related procedures.

To evaluate any beneficial effect of progesterone supplementation during the luteal phase of GIFT or IVF cycles stimulated by clomiphene citrate and HMG, two random prospective studies were performed. In the first study, a group of patients received a luteal phase supplement of 50 mg natural progesterone i.m. daily from the day of oocyte retrieval onwards. Initial results on 168 patients indicated that the pregnancy rate was similar in patients with or without progesterone supplements. No differences were found between the two groups in an analysis of pregnant and failed cycles. In a second study two different protocols of luteal phase supplementation after Buserelin-HMG stimulation were compared: natural progesterone in combination with oestradiol valerate (50 patients) or HCG supplements (41 patients). A 32% pregnancy rate per cycle was encountered in both groups. Endometrial biopsies, taken during the luteal phase from patients who did not undergo embryo replacement, revealed retarded endometrial development in most of the biopsies.

Buserelin↗

The luteal phase and early pregnancy after combined GnRH-agonist/HMG treatment for superovulation in IVF or GIFT.

Endometrial biopsies showing inadequate development were observed after ovarian stimulation with the GnRH agonist Buserelin and HMG for IVF or GIFT when luteal supplementation was omitted. Ninety-one patients were randomly allocated to two luteal supplementation regimens: in 41 women HCG and in 50 women progesterone and oestradiol valerate. The pregnancy patients treated with a combination of the GnRH agonist and HMG a delay of implantation of 1.3 days was observed compared to pregnancies after clomiphene citrate-HMG stimulation. This delay was not due to slower preimplantation embryo development after GnRH agonist-HMG treatment. Temporarily defective function of the corpus luteum was evidenced by measuring serum progesterone, 17 beta-oestradiol and 17-hydroxyprogesterone in the patients receiving progesterone and oestradiol valerate. This inadequate corpus luteum function could be related to the prolonged blockage of pituitary gonadotrophic function after arrest of the GnRH agonist.

Buserelin↗

Oocyte donation in patients without ovarian function.

The clinical, hormonal and cytogenetic findings in 36 women with primary ovarian failure, referred for oocyte or embryo donations are reported. Fifteen women were suffering from ovarian dysgenesis and 11 from premature menopause. Six of these 26 patients showed X-chromosome abnormalities. One patient had a Noonan syndrome. The remaining 10 had surgical menopause. The mean duration of their infertility was 6.5 +/- 3.2 years (+/- SD). All patients had elevated serum gonadotrophins within the menopausal range. Hypothalamic, pituitary and thyroid function were found to be intact. In one of the 15 ovarian biopsies on the patients with chromosomal competent ovarian failure, primordial follicles were found. Hysterosalpingograms revealed a normal uterine cavity in all patients. In view of oocyte donation, careful evaluation of the obstetric risk was mandatory in the six patients with X-chromosome aberrations and in the patient with the Noonan syndrome, because of their short stature and possible concomitant cardiovascular and renal disease. After substitution therapy with oestradiol valerate and natural progesterone, 13 pregnancies were established, seven patients delivered (one set of twins), eight healthy children were born, three pregnancies aborted and three pregnancies are progressing normally.

Adult↗

Evaluation of different biopsy methods of blastomeres from 2-cell mouse embryos.

As an outgrowth of in-vitro fertilization and embryo transfer, detection of genetic and metabolic defects prior to implantation might be possible in the future. The objective for preimplantation diagnosis would be to sample a minimum of cell material of the conceptus for diagnosis prior to transfer. Different protocols for isolating individual blastomeres out of 2-cell mouse embryos were evaluated. 2-cell mouse embryos (from F1 hybrids C57B1 females x CBA males) were collected and the zona pellucida was removed by enzyme treatment (pronase), by exposure to Ca2+-Mg2+-free acid Tyrode (pH = 2.5) or by mechanical force. Individual blastomeres were obtained by exposure to an enzyme (pronase), to a chelating agent (EDTA-glycine mixture), to Ca2+-Mg2+-free PBS or after isolation by mechanical force. The biopsied blastomeres were then cultured in vitro as such or first replaced into a host zona pellucida. Evaluation was performed by culture in vitro up to the blastocyst stage and by transfer of embryos appearing morphologically normal into pseudopregnant foster mothers. A chromosomal study of the second mitotic division of the isolated blastomere was also performed. All isolation procedures had a negative impact on the in-vitro and in-vivo growth patterns of the isolated blastomeres. After culture in vitro to the blastocyst stage, different abnormalities could be observed: embryos lacking compaction, embryos with double blastocoelic cavities and embryos with no inner cell mass (trophoblastic vesicle). After replacement of the isolated blastomeres into a host zona pellucida, similar observations could be made. Chromosomal analysis did not reveal a clear influence of the different biopsy methods on the mitosis of the isolated blastomeres.

Animals↗

[Genital condylomas in women. Treatment using a CO2 laser: analysis of 141 cases].

141 patients who had lesions caused by human papilloma virus (HPV) in the vulva and vagina (63 cases) or in the cervix (78 cases) were routinely treated solely by using CO2 laser. The lesions were vaporized when they were localised to the perineum and in certain selected cases in the cervix after they had been examined colposcopically and had biopsies taken. We resorted to conisation when lesions were not completely visible or when they were associated with CIN III (severe dysplasia and carcinoma in situ). Vulvo-vaginal condylomata present with certain characteristics: the infected population is young (a mean age of 27), most (81%) have diffuse forms of the condition, of the partners examined 68% were contaminated. Association with flat cervical lesions with or without dysplasia is not rare (18% of cases). Finally, treatment using only CO2 laser seems to us to be disappointing: only 55% were cured after one treatment and 84% after repeated treatments. When the condylomatous lesions on the cervix were flat we found an associated intra-epithelial neoplasia (CIN) in 66% of cases. In these cases the mean age of the patients was 28 years when these were pure viral lesions and 33 years of age when there was an associated dysplasia. Here the results after laser treatment can be considered as satisfactory because they were respectively 97 and 94% of cures whether the lesions had or did not have dysplasia. On the other hand, in our series the junction between pavement and cylindrical cells was always visible after treatment with the laser, and that made it easy to follow up these patients.

Adolescent↗

[Coloscopy].

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Colonoscopes↗

[In vitro fertilization. Analysis of results after the first 2 years' activity].

413 menstrual cycles were monitored in the first two years of the work of the In-Vitro Fertilization Unit in La Pitié-Salpêtrière. On-going pregnancies were achieved from the very first months of activity, with a level which stayed relatively constant in the first year. Technical changes were introduced and in particular a higher recovery rate of oocytes when ultrasound was used and above all when LH-RH analogues were used in the process of stimulation. It is this last point that seems to be the most interesting. In fact, when the results are examined there is a definite rise in the number of on-going pregnancies of which the level went up by 2.3 times as compared with using a classical protocol of Clomithene citrate and HMG. In the 153 cycles when D-Trp6 LH-RH was used, the percentage of on-going pregnancies was 13.7% for each cycle and 20% for embryo implants. Furthermore, it became possible to work out the dates for the patients and this appears to us essential as the numbers of couples attending increase.

Age Factors↗