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Biomedical subjects

S Alvarez

Publications and source records attributed to S Alvarez.

At least 91 records · Page 5Linked to original sources
PubMed1993

Granulosa cells improve human embryo development in vitro.

A total of 17 couples with repetitive implantation failure after transfer of fresh or frozen-thawed embryos had half of their zygotes cultured in standard conditions and frozen at day 2 after insemination, and the other half cocultured with autologous granulosa cells and transferred at the morula or blastocyst stage at day 5 or 6 after oocyte retrieval. At the end of the culture period, supernatants of cocultures were recovered for steroid assays. Monolayers were stained for granulosa cell growth and morphological assessment. We observed that granulosa cells improve embryo development in vitro since 32 out of 60 (53%) reached the morula stage and 18 (30%) the blastocyst stage, leading to a total of 83% embryos available for transfer (compared with 3% without coculture). The ongoing pregnancy rate of these patients who were selected because they had at least three previous implantation failures, is only 5.9%, however, which is similar to the control group without coculture (6.3%). To conclude, granulosa cells improve embryo development but not the pregnancy rate after transfer of cocultured embryos in patients with multiple previous implantation failures.

Adult↗
PubMed1993

[Hyperstimulation for in vitro fertilization with the "step-down" technique. Preliminary results from a prospective randomized study with and without LHRH agonists].

Twenty six normo-ovulatory patients < 38 years with tubal or idiopathic infertility and normal sperm were treated for IVF by FSH +/- hMG and randomized into four groups: with and without LHRH agonist, "step-up" or "step-down" stimulation. In the step down protocol, after 4 days with 4 amps plasmatic FSH reached its top level, then decreased. Despite reduction to only two amps, estradiol continued to increase in all the 5 women without agonist, whereas 3/7 with the long protocol were considered as low responders and stopped. The fertilization/cleavage rate was 69.2% in step-down and 45.7% in step-up (p < 0.04) with the short protocol, and respectively 65.6% and 41.9% (p < 0.03) with the long one. The pregnancy rate was equivalent in all groups.

Adult↗
PubMed1993

[3 beta-hydroxysteroid dehydrogenase defect: frequency of presentation in a sample of Chilean hirsute women].

The defect of 3 beta hydroxysteroid dehydrogenase (3 beta HSD) is frequent among hirsute women and clearly dependent on the ethnic composition of the studied population. Our aim was to study the frequency of 3 beta HSD deficit in a group of Chilean hirsute women. Basal and post ACTH concentrations of cortisol, 17 hydroxyprogesterone and 17 hydroxypregnenolone were measured by RIA in 40 hirsute post puberal women and in 15 normal age matched female volunteers. Criteria for considering a 3 beta HDS deficit were 17 hydroxypregnenolone values and 17 hydroxypregnenolone/17 hydroxyprogesterone and 17 hydroxypregnenolone/cortisol ratios after ACTH stimulation over the 95% confidence intervals of normal women. Basal dehydroepiandrosterone sulphate and testosterone levels were also measured in hirsute women. All samples were obtained during the follicular phase of the menstrual cycle. ACTH stimulated hormone values and ratios were diagnostic for 3 beta HDS deficit in 7.5% of hirsute women. Basal testosterone was over 80 ng/dl in 47.5% and dehydroepiandrosterone sulphate over 3.9 micrograms/ml in 52.5% of these women. There was no correlation between dehydroepiandrosterone or testosterone values and ACTH stimulated hormone values. It is concluded that 3 beta HSD is frequent in hirsute women and that its diagnosis requires the determination of ACTH stimulated 17 hydroxypregnenolone values and 17 hydroxypregnenolone/17 hydroxyprogesterone ratio.

17-alpha-Hydroxypregnenolone↗
PubMed1992

Hormonal secretions in singleton pregnancies arising from the implantation of fresh or frozen embryos after oocyte donation in women with ovarian failure.

OBJECTIVE: To determine whether levels of human chorionic gonadotropin (hCG), 17 beta-estradiol (E2), and progesterone (P) are different in the peri-implantation phase of fresh versus frozen embryos. DESIGN: Hormonal secretions were measured on days 9 and 11 after implantation and at 4, 5, and 6 weeks gestation. PATIENTS: Thirty-one pregnancies were achieved in 65 patients with ovarian failure. Seventeen singleton pregnancies developed after implantation of 4 frozen and 13 fresh embryos. RESULTS: Human chorionic gonadotropin and E2, contrary to P, were higher in cases of fresh embryos from the 9th day after transfer to the 5th week at which time they become statistically significant (respectively, for hCG and E2, 5,800.3 +/- 332.3 versus 2,027.3 +/- 916.3 [mean +/- SD] mIU/mL for hCG and 562.3 +/- 215 versus 291 +/- 152 pg/mL for E2). CONCLUSIONS: This difference might be explained by either the higher number of fresh embryo replaced or by the fact that the number of blastomeres and also their metabolic activity could be reduced after freezing and thawing.

Adult↗
PubMed1992

Infections in the compromised host.

The normal defense mechanisms against infection include (1) normal skin and mucous membranes, (2) humoral immunity, (3) phagocytic system, and (4) cellular immunity. The compromised (immunocompromised) host is an individual who has one or more deficiencies in these defense mechanisms. This article reviews potential infections in the compromised host as well as an approach to evaluation of these patients.

Antibody Formation↗
PubMed1992

Is there an indication for embryo reduction?

The selective reduction of embryos in multiple pregnancies poses numerous medical, technical, ethical and psycho-social problems. In a retrospective study, we analysed nine hundred and twenty-two pregnancies obtained using medically assisted procreation between May 1982 and May 1990. Among 922 successful pregnancies, 372 were singleton, 102 were twin and 13 were triplet. Data from this analysis and from a French multicentre study of 262 embryo reduction procedures demonstrated the value of an embryo quality score for minimizing the risk of multiple pregnancy and the existence of extremely infrequent, ethically acceptable indications for embryo reduction. These indications included ultrasound-proven malformations of one fetus, multiple pregnancies in patients with extensive uterine scarring, and multiple pregnancy despite the appropriate use of preventative measures which can be expected to make this technique unnecessary in the future.

Abortion, Therapeutic↗
PubMed1992

[Prognostic value of preovulatory elevations of plasma progesterone during in vitro fertilization using LHRH agonists in a long protocol].

We retrospectively analyzed the prevalence and prognostic significance of plasma progesterone rises during in vitro fertilization (IVF) protocols including pituitary down-regulation by LHRH agonists in a long protocol and stimulation by hMG (n = 1,116: Group A) or pure FSH (n = 178: Group B). On the day of hCG injection, plasma progesterone level was in the 0.60-0.99 ng/ml range in 7.1% of group A patients and 6.2% of group B patients (NS) and above 1 ng/ml in respectively 4.0% and 3.4% of the cases (NS). On the same day, plasma progesterone was strongly correlated with plasma estradiol (r = 0.26 - p < 0.001 in group A; r = 0.21 - p < 0.01 in group B). However, increased progesterone levels were not associated with changes in plasma LH levels, falls in plasma estradiol levels after hCG injection, or significant modifications in biological and clinical results of IVF. The cause of this pattern of progesterone rise remains to be elucidated.

Buserelin↗
PubMed1992

Atraumatic severe streptococcal axillary cellulitis.

Axillary streptococcal cellulitis is rare but has been known to clinicians for years. Usually associated with trauma, it may, however, occur in previously healthy individuals who for unknown reasons can be slowly responsive to appropriate antibiotics.

Adult↗
PubMed1991

Immunoadjuvant activity of oral Lactobacillus casei: influence of dose on the secretory immune response and protective capacity in intestinal infections.

Lactobacilli, often used as effectors of host functions, could play an important role in maintaining human health by controlling other intestinal microorganisms capable of producing harmful effects. Using an experimental model, we studied the effect of different oral doses of Lactobacillus casei on the secretory IgA response and the protective capacity of the microorganism in preventing intestinal infections. The optimization of the protective dose of Lb. casei by previous feeding and the use of the lactobacillus as an immunological way to control enteric infections were investigated. We found that conventional mice were protected against infection with Salmonella typhimurium and Escherichia coli by previous feeding for 2 consecutive days with a daily Lb. casei dose of 1.2 x 10(9) cfu/mouse. Previous feeding for 7 d proved less effective, and feeding for 5 d afforded no protection at all. We were also able to demonstrate that the protective effect of Lb. casei against Sal. typhimurium and Esch. coli was connected mainly with the high level of IgA antipathogen antibodies present in intestinal secretions. beta-Glucuronidase (EC 3.2.1.31) and beta-galactosidase (EC 3.2.1.23) activities, measured both in the intestinal fluid and histological samples, showed a marked increase in intestinal inflammatory response on day 5 of feeding. These results show that Lb. casei plays an important role in the prevention of enteric infections, a low dose being enough for protection against intestinal infections by increasing IgA secretion into the intestinal lumen, thus providing adequate defences for the mucosal surface. A previously administered dose of this magnitude could therefore be used as an oral adjuvant in preventing enteric infections.

Adjuvants, Immunologic↗
PubMed1991

Comparison of plasma and follicular fluid hormone profiles following stimulation with HMG, with or without LHRH agonists, for in-vitro fertilization.

Plasma and follicular fluid (FF) hormone assays for follicle stimulating hormone (FSH), luteinizing hormone (LH), prolactin (PRL), oestradiol (E2), progesterone (P), delta-4-androstenedione (A4) and testosterone (T) were performed on the day of oocyte retrieval in two groups of normo-ovulatory women enrolled in an in-vitro fertilization (IVF) programme: 24 were treated using the decapeptyl agonists DTRP6, of luteinizing hormone-releasing hormone (LHRH) in the long protocol associated with human menopausal gonadotrophin (HMG) (49 FF) and 14 were stimulated with HMG alone (33 FF). In both FF and plasma the mean concentration of P was greater, and the E2/P ratios as well as the LH levels were lower in the agonist-treated group. In this group the follicular concentration of P was greater and the E2/P ratio lower when pregnancy occurred following IVF. The hormonal modifications may be due to greater functional maturity of the granulosa cells.

Estradiol↗
PubMed1990

Prevention of gastrointestinal infection using immunobiological methods with milk fermented with Lactobacillus casei and Lactobacillus acidophilus.

The protective effect of feeding milk fermented with a mixture of Lactobacillus casei sp. and Lb. acidophilus sp. against Salmonella typhimurium infection in mice was compared with that obtained feeding milks fermented with these microorganisms individually. The survival rate obtained after oral infection with Sal. typhimurium was 100% in mice pretreated by feeding during 8 d with the mixture of Lb. casei and Lb. acidophilus fermented milks. Similar treatments with the individual milks were ineffective. Moreover, mice became more susceptible to infection with Sal. typhimurium after such treatment. The colonization of liver and spleen with the pathogen was markedly inhibited by the pretreatment with the mixture of fermented milk, while such inhibition was not observed using the Lb. casei and Lb. acidophilus milks. The highest levels of anti-salmonellae antibodies in serum and in intestinal fluid were found in the group of mice fed with the mixture and with Lb. casei fermented milk respectively. However, this latter milk was not effective in protecting against Sal. typhimurium. When the mice were first infected with Sal. typhimurium and then fed with the mixture of fermented milks, pathogen colonization was not prevented. The results suggest that the augmentation of resistance to salmonellae caused by the treatment with Lb. casei- + Lb. acidophilus-fermented milk was due to the anti-salmonellae protective immunity mainly mediated by the mucosal tissue. Milk fermented with this mixture could be used as an immunobiological method to prevent gastrointestinal infection.

Animals↗
PubMed1990

Treatment of hyperstimulation during in-vitro fertilization.

In 33 patients treated with a combination of an LHRH agonist (LHRH-A) and gonadotrophin in a long protocol, a biological hyperstimulation occurred (E2 greater than 2500 pg/ml on the day of HCG administration and 4722 +/- 1190 pg/ml the day after, with greater than 10 follicles greater than 12 mm on each ovary). The replacement of fresh embryos were deferred and LHRH-A was continued, and an endometrial biopsy was performed on the theoretical day of replacement (2 days after oocyte recovery). With this technique, we obtained a mean number of 17.9 +/- 7 oocytes, a fertilization rate of 49% and a replacement rate of 87% in a deferred cycles. The overall pregnancy rate of frozen-thawed embryos was 27% in the seven spontaneous cycles, 12 induced cycles and 10 artificial cycles. Only one severe hyperstimulation occurred and this case emphasizes that caution remains necessary even with this technique.

Embryo Transfer↗
PubMed1990

Pregnancies following ovum donation in gonadal dysgenesis.

Between February 1987 and February 1989, 13 women with primary ovarian failure due to gonadal dysgenesis were treated with embryo transfer following ovum donation in 22 cycles. Eight pregnancies were obtained (36.7% per transfer); four births of normal children, two spontaneous abortions and two other pregnancies currently ongoing (between 5 and 8 months). An association of percutaneous oestradiol, oestradiol valenate and intravaginal progesterone was used as hormone substitution and embryo transfer was only performed following assessment of the endometrium during a previous cycle. Apart from the day of embryo transfer, which was the same for all patients (the 2nd day after initiation of progesterone) various prognostic factors were analysed. These were the type of gonadal dysgenesis (45 XO, 46 XX or 46 XY), the number of embryos replaced, whether they had been frozen, whether the egg donor was anonymous and finally the influence of the hormone substitution protocol. Only the number of embryos replaced and the substitution protocol seemed to influence the implantation rate. The other parameters, and in particular the type of gonadal dysgenesis, seemed to have no effect on the results. The pregnancy rate per transfer was 30% for 45 XO (10 transfers), 25% for 46 XX (eight transfers) and 75% for 46 XY (four transfers).

Adult↗
PubMed1990

Ovarian stimulation using human menopausal gonadotrophins with or without LHRH analogues in a long protocol for in-vitro fertilization: a prospective randomized comparison.

In order to evaluate the exact role of GnRH agonists, we have undertaken a randomized prospective study comparing two groups of 90 normo-ovulatory patients, aged less than 38 years and with tubal infertility with no male factor. Luteinizing hormone releasing hormone analogue (DTRP6 administered in a long protocol, for at least 15 days) was associated with human menopausal gonadotrophin (HMG) induction in group I. In group II, stimulation was performed using HMG alone (three ampoules per day in general, from days 2 to 7 of the cycle). Apart from the well known results demonstrated in the literature of a reduced incidence of inadequate responses, an absence of premature luteinization and a greater number of oocytes per retrieval (8.8 +/- 4.9 versus 6.8 +/- 3.2, P less than 0.01 in group II), this study confirms the higher pregnancy rate (21.1 versus 12.2% per cycle and 24.7 versus 17.1% per oocyte retrieval, not significant) and underlines the higher plasma progesterone levels and lower E2/P ratio in group I from D - 1 to D + 5, which could explain a better maturation of the oocytes and the endometrium.

Adult↗
PubMed1990

Delayed life-threatening pneumonitis secondary to procarbazine.

A patient with advanced Hodgkin's disease being treated with MOPP chemotherapy presented with delayed life-threatening pulmonary toxicity secondary to procarbazine. The pulmonary toxicity began 1 week after procarbazine had been discontinued and once recognized was successfully treated with intravenous steroids.

Adult↗