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Biomedical subjects

A Lass

Publications and source records attributed to A Lass.

At least 37 records · Page 2Linked to original sources
PubMed1999

The effect of endometrial polyps on outcomes of in vitro fertilization (IVF) cycles.

PURPOSE: Our purpose was to investigate the effect of endometrial polyps on pregnancy outcome in an in vitro fertilization (IVF) program. METHODS: Endometrial polyps less than 2 cm in diameter were suspected by transvaginal ultrasound before oocyte recovery in 83 patients. Forty-nine women (Group I) had standard IVF-embryo transfer, while in 34 women (Group II) hysteroscopy and polypectomy were performed immediately following oocyte retrieval, the suitable embryos were all frozen, and the replacement cycle took place a few months later. RESULTS: Of the 32 hysteroscopies, a polyp was diagnosed in 24 cases (75%) and polypoid endometrium in another 5 patients (15.6%). An endometrial polyp was confirmed by histopathological examination in 14 women (58.3%). The pregnancy rate in group I was similar to the general pregnancy rate of our unit over the same period (22.4 vs 23.4%) but the miscarriage rate was higher (27.3 vs 10.7%, P = 0.08). In Group II, the pregnancy and miscarriage rates were similar to those of the frozen embryo cycles at Bourn Hall (30.4 and 14.3 vs 22.3 and 12.1%, respectively). CONCLUSIONS: Small endometrial polyps, less than 2 cm, do not decrease the pregnancy rate, but there is a trend toward increased pregnancy loss. A policy of oocyte retrieval, polypectomy, freezing the embryos, and replacing them in the future might increase the "take-home baby" rate.

Adult↗
PubMed1998

Electron transport-linked ubiquinone-dependent recycling of alpha-tocopherol inhibits autooxidation of mitochondrial membranes.

The objective of this study was to elucidate the anti-oxidative roles of coenzyme Q (CoQ) and alpha-tocopherol in mitochondrial membranes by determining whether CoQ directly scavenges peroxyl- and alkoxyl-radicals or indirectly regenerates alpha-tocopherol during autooxidation of mitochondrial membranes. A comparison of the interaction between alpha-tocopherol and CoQ during autooxidation was made between bovine and rat heart mitochondria, which differ approximately 15-fold in their alpha-tocopherol content. Autooxidation of both bovine and rat heart mitochondria resulted in the formation of thiobarbituric-acid-reactive substances and protein carbonyls; however, the differences in the autooxidizability of mitochondria between rat and bovine heart mitochondrial membranes were relatively minor. Supplementation of rat heart mitochondria with succinate caused reduction of CoQ to ubiquinol while alpha-tocopherol concentration remained unaffected during autooxidation. In contrast, in the absence of succinate, CoQ was present in the oxidized form (ubiquinone) and the mitochondrial membranes were depleted of alpha-tocopherol. CoQ concentrations remained unchanged over time irrespective of the presence or absence of succinate. In the absence of succinate, autooxidation of bovine SMPs, supplemented with different amounts of alpha-tocopherol, was inversely related to the amount of alpha-tocopherol, whereas in the presence of succinate autooxidation was greatly reduced. Results of this study indicate that during autooxidation of mitochondria, alpha-tocopherol acts as the direct radical scavenger, whereas ubiquinol regenerates alpha-tocopherol.

Animals↗
PubMed1998

One thousand initiated cycles of in vitro fertilization in women > or = 40 years of age.

OBJECTIVE: To evaluate the results of IVF in women > or = 40 years of age using their own oocytes. DESIGN: Retrospective study. SETTING: Wolfson and Royal Masonic in vitro fertilization units, London, United Kingdom. PATIENT(S): A total of 1,087 IVF cycles were started in women > or = 40 years of age. INTERVENTION(S): Medical records of patient outcomes were reviewed. MAIN OUTCOME MEASURE(S): Clinical pregnancy, miscarriage, and delivery rates. RESULT(S): Of the 1,087 cycles started in 471 women > or = 40 years of age, 842 reached oocyte retrieval (77.5%) and 702 had embryos transferred (64.6%). The pregnancy rate (PR) was significantly lower in women > or = 40 years of age than in a control group of women <40 years of age (11.3% versus 28.2%). It decreased sharply in women >42 years of age, and no women >45 years of age had a child. Women > or = 40 years of age were more likely to miscarry (27% versus 12.7%). When only one embryo was available for transfer, the PR was 3.3%. When >2 embryos were available for transfer, the PR was similar whether 2 or 3 embryos were replaced. No triplet pregnancy occurred. Women > or = 40 years of age achieved a cumulative PR of 30% after three cycles with a cumulative "take home baby" rate of 21%. CONCLUSION(S): In vitro fertilization is a reasonable treatment for women <45 years of age using their own gametes. Those with a "good response" in their first attempt may be encouraged to complete three cycles with an acceptable chance of conception.

Adult↗
PubMed1998

Effect of salpingectomy on ovarian response to superovulation in an in vitro fertilization-embryo transfer program.

OBJECTIVE: To investigate the effect of salpingectomy on the response of each ovary in patients undergoing an IVF-ET treatment cycle and to compare the results with those of patients who had not had surgery and were undergoing IVF-ET during the same period. DESIGN: A prospective study. SETTING: Tertiary referral academic IVF unit. PATIENT(S): Twenty-nine ET cycles were evaluated in 29 patients who previously had undergone unilateral salpingectomy because of ectopic pregnancy (study group). Seventy-three patients with unexplained or male factor infertility served as controls. INTERVENTION(S): Ovulation induction and IVF-ET. MAIN OUTCOME MEASURE(S): In the study group, mean ovarian volume, number of follicles, and number of oocytes recovered from each ovary were assessed and compared. The overall results, cycle characteristics, and pregnancy rates of the two groups were compared. RESULT(S): Among the patients who had undergone salpingectomy, significantly fewer follicles developed and consequently fewer oocytes were retrieved from the ovary on the operated side (4.4 versus 8.2 follicles and 3.8 versus 6.0 oocytes). There were no differences in the total numbers of follicles and oocytes recovered from both ovaries, the cycle characteristics, or the pregnancy rates between study and control groups. CONCLUSION(S): Salpingectomy has no detrimental effect on the total ovarian performance during IVF-ET treatment or on the outcome of IVF-ET. However, the ipsilateral ovary could be adversely affected. This could be detrimental in selected patients undergoing IVF-ET, in whom the second ovary already is compromised or missing.

Adult↗
PubMed1998

Caloric restriction prevents age-associated accrual of oxidative damage to mouse skeletal muscle mitochondria.

The purpose of this study was to understand the nature of the causes underlying the senescence-related decline in skeletal muscle mass and performance. Protein and lipid oxidative damage to upper hindlimb skeletal muscle mitochondria was compared between mice fed ad libitum and those restricted to 40% fewer calories--a regimen that increases life span by approximately 30-40% and attenuates the senescence-associated decrement in skeletal muscle mass and function. Oxidative damage to mitochondrial proteins, measured as amounts of protein carbonyls and loss of protein sulfhydryl content, and to mitochondrial lipids, determined as concentration of thiobarbituric acid reactive substances, significantly increased with age in the ad libitum-fed (AL) C57BL/6 mice. The rate of superoxide anion radical generation by submitochondrial particles increased whereas the activities of antioxidative enzymes superoxide dismutase, catalase, and glutathione peroxidase in muscle homogenates remained unaltered with age in the AL group. In calorically-restricted (CR) mice there was no age-associated increase in mitochondrial protein or lipid oxidative damage, or in superoxide anion radical generation. Crossover studies, involving the transfer of 18- to 22-month-old mice fed on the AL regimen to the CR regimen, and vice versa, indicated that the mitochondrial oxidative damage could not be reversed by CR or induced by AL feeding within a time frame of 6 weeks. Results of this study indicate that mitochondria in skeletal muscles accumulate significant amounts of oxidative damage during aging. Although such damage is largely irreversible, it can be prevented by restriction of caloric intake.

Age Factors↗
PubMed1998

Histological evaluation of endometrium on the day of oocyte retrieval after gonadotrophin-releasing hormone agonist-follicle stimulating hormone ovulation induction for in-vitro fertilization.

The objective of this study was to evaluate the histopathological characteristics of endometrial biopsies taken on the day of oocyte recovery in in-vitro fertilization (IVF) cycles with a satisfactory response to ovulation induction. A group of 33 patients who went through ovulation induction for IVF, and in whom an endometrial polyp was suspected on transvaginal ultrasonography during the monitoring phase, were studied. Following oocyte recovery, hysteroscopy, polypectomy and endometrial curettage were performed. Dating of endometrial glands and stroma was carried out in the tissue not containing the polyps. The total dose of follicle stimulating hormone (FSH), duration of ovulation induction, peak oestradiol and luteinizing hormone (LH) concentrations, thickness of endometrium and number of oocytes were recorded and compared to the endometrial dating of the specimens. In 15 cycles (45.5%), the endometrium was classified as 'in phase' (group I), 'advanced' by 2-4 days in a further 15 (45.5%, group II), and in the remaining three cycles (9%) it was delayed in maturation (group III). Younger age was correlated with advanced staging of the endometrium (r = -0.42; P = 0.015). Women with 'in phase' and 'advanced' maturation were similar in their response to ovulation induction; however, there was a strong correlation between advanced dating of endometrium and number of oocytes retrieved (r = 0.49; P = 0.04). Endometrial staging on the day of oocyte retrieval varied widely in patients treated by the same gonadotrophin-releasing hormone agonist (GnRHa)/FSH protocol for ovulation induction. This difference was not predictable by parameters monitored through the cycles.

Adult↗
PubMed1998

A programme of semen cryopreservation for patients with malignant disease in a tertiary infertility centre: lessons from 8 years' experience.

The improved survival in recent years of young males suffering from cancer, and an understanding of the gonadotoxic effects of chemotherapy treatment, have motivated patients and clinicians to preserve fertility potential before embarking on adjuvant therapy. Among 231 men (mean age 28.0; range 15-56 years) diagnosed with malignant disease and referred to our unit for semen cryopreservation, 112 patients (49.8%) had reduced sperm quality of <10 x 10(6) motile spermatozoa per ejaculate; however, most had sufficient suitable spermatozoa for freezing. In 40 patients (17.3 %) the semen samples were not frozen because of complete azoospermia (n = 32) or only immotile sperm in the ejaculate (n = 2), while six men were unable to produce a single sample. Some 79 men had testicular tumours (group I), 121 suffered from haematological malignancy (leukaemia or lymphoma; group II), and 27 had cancer of different causes (group III). Men in group I had significantly lower (P < 0.001) sperm quality compared with groups II and III. There was no difference between patients with seminoma and non-seminoma tumours. In the haematological malignancy group there was no difference in sperm parameters between leukaemia (n = 12) and lymphoma (n = 77) patients, but patients with Hodgkin's lymphoma had significantly lower sperm quality compared with non-Hodgkin's lymphoma. Following chemotherapy, six couples attended the clinic for assisted conception treatment using the frozen semen. Two had successful intrauterine insemination cycles which each resulted in delivery of a healthy girl; one couple had conceived in their first in-vitro fertilization (IVF) attempt, followed by delivery of healthy twins. Two women conceived after intracytoplasmic sperm injection treatment and the sixth woman achieved only biochemical pregnancy after numerous IVF and frozen embryo replacement cycles. We recommend that a properly designed programme for semen cryopreservation for cancer patients should be developed in leading tertiary assisted conception centres, which have adequate facilities and experience for cryopreservation and can offer the whole range of appropriate assisted reproductive treatment and counselling.

Adolescent↗
PubMed1998

Predictive value of the results of a first in-vitro fertilization cycle on the outcome of subsequent cycles.

This study examines the relationship between the first cycle of in-vitro fertilization (IVF) and subsequent cycles. The results of all IVF cycles conducted at The Hammersmith Hospital or The Royal Masonic Hospital between 1988 and 1995 were studied including those cycles where egg recovery was abandoned due to poor ovarian response. All patients underwent a standardized treatment protocol. Of those women who achieved a clinical pregnancy during their first IVF attempt, 33% achieved a pregnancy during their second cycle, statistically significantly different from the 24% of patients conceiving during a second cycle who had failed to conceive during their first. 36% of those who achieved a biochemical pregnancy in their first cycle became pregnant in their second. Age was an important factor in the success of IVF treatment, with pregnancy rates of 48% in the 20-25 year age group falling to 8% in those aged > or =41 years. Cumulative pregnancy rates were 26% after one cycle, increasing to 43% after two cycles and reached 80% after seven cycles. A previous pregnancy significantly improved a couple's probability of conception in a later IVF cycle. Overall pregnancy rates per cycle were constant for the first three attempts. Cumulative pregnancy rates continued to rise to 72% after six cycles. Thus the more cycles a couple undergo (up to six) the greater their chance of a pregnancy.

Adult↗
PubMed1997

Mitochondrial ubiquinone homologues, superoxide radical generation, and longevity in different mammalian species.

Rates of mitochondrial superoxide anion radical (O-2) generation are known to be inversely correlated with the maximum life span potential of different mammalian species. The objective of this study was to understand the possible mechanism(s) underlying such variations in the rate of O-2 generation. The hypothesis that the relative amounts of the ubiquinones or coenzyme Q (CoQ) homologues, CoQ9 and CoQ10, are related with the rate of O-2 generation was tested. A comparison of nine different mammalian species, namely mouse, rat, guinea pig, rabbit, pig, goat, sheep, cow, and horse, which vary from 3.5 to 46 years in their maximum longevity, indicated that the rate of O-2 generation in cardiac submitochondrial particles (SMPs) was directly related to the relative amount of CoQ9 and inversely related to the amount of CoQ10, extractable from their cardiac mitochondria. To directly test the relationship between CoQ homologues and the rate of O-2 generation, rat heart SMPs, naturally containing mainly CoQ9 and cow heart SMPs, with high natural CoQ10 content, were chosen for depletion/reconstitution experiments. Repeated extractions of rat heart SMPs with pentane exponentially depleted both CoQ homologues while the corresponding rates of O-2 generation and oxygen consumption were lowered linearly. Reconstitution of both rat and cow heart SMPs with different amounts of CoQ9 or CoQ10 caused an initial increase in the rates of O-2 generation, followed by a plateau at high concentrations. Within the physiological range of CoQ concentrations, there were no differences in the rates of O-2 generation between SMPs reconstituted with CoQ9 or CoQ10. Only at concentrations that were considerably higher than the physiological level, the SMPs reconstituted with CoQ9 exhibited higher rates of O-2 generation than those obtained with CoQ10. These in vitro findings do not support the hypothesis that differences in the distribution of CoQ homologues are responsible for the variations in the rates of mitochondrial O-2 generation in different mammalian species.

Animals↗
PubMed1997

Measurement of ovarian volume by transvaginal sonography before ovulation induction with human menopausal gonadotrophin for in-vitro fertilization can predict poor response.

The study tests the hypothesis that small ovaries measured on transvaginal sonography (TVS) are associated with a poor response to ovulation induction by human menopausal gonadotrophin (HMG) for in-vitro fertilization (IVF). A total of 140 infertile patients with morphologically normal ovaries undergoing IVF was studied. The mean ovarian volume of each patient was measured on TVS before starting HMG. Subsequent routine IVF management was conducted without knowledge of the results of TVS. The mean ovarian volume was 6.3 cm3 (range 0.5-18.9, SD= 3.1). Patients (n = 17; group A) with small ovaries of < 3 cm3 (i.e. overall mean volume - 1 SD) were compared to patients (n = 123; group B) with ovaries > or = 3 cm3. Both groups were of similar age (mean 35.8 versus 34.4 years). Early basal FSH concentrations were increased in group A (9.5 versus 7.0 mIU/ml, P = 0.025). The cycle was abandoned before planned oocyte recovery in nine patients (52.8%) from group A and in 11 patients (8.9%) from group B because of poor response to ovulation induction (P < 0.001). Increased age and ovarian volume were associated independently with cancellation of the cycles. The remaining eight patients from group A who had oocytes retrieved required higher doses of HMG (87.5 versus 53.8 ampoules, P < 0.01), yielded fewer follicles (10.3 versus 14.5, P < 0.05) and fewer oocytes were recovered from them (6.8 versus 11.0, P < 0.05) compared with group B. There was no difference in the fertilization or pregnancy rates or the number of embryos available for transfer in either group. Our results indicate a strong association between ovarian volume and ovarian reserve. Small ovaries are associated with poor response to HMG and a very high cancellation rate during IVF. Assessment of ovarian size should be an integral part of infertility evaluation.

Adult↗
PubMed1997

Women with one ovary have decreased response to GnRHa/HMG ovulation protocol in IVF but the same pregnancy rate as women with two ovaries.

The study compares the response after gonadotrophin-releasing hormone agonist (GnRHa) and human menopausal gonadotrophin (HMG) stimulation for in-vitro fertilization (IVF) in patients with either one or two ovaries. The study group (group A) included 73 cycles in women who had unilateral oophorectomy before their IVF treatment and the control group (group B) included 988 cycles in women with two ovaries. Tubal disease was the sole cause for infertility in all cases. The two groups were similar in age and parity. The patients with one ovary required more ampoules of HMG (62.9 versus 48.9, P < 0.001), a longer induction period (13.5 versus 12.7, P < 0.01) and had significantly lower oestradiol concentrations on the day of human chorionic gonadotrophin (HCG) administration (5840 versus 6473 pmol/l, P = 0.035). They yielded fewer follicles (11.2 versus 13.1, P = 0.005), fewer oocytes (7.3 versus 9.1, P = 0.006) and produced fewer embryos (4.4 versus 5.1, P < 0.05). There was no difference in fertilization rate (60 compared with 58%), or pregnancy rate (25.8 compared with 27.1% per oocyte retrieval). Women with only one ovary responded less well to GnRH agonist/HMG stimulation than women who had both ovaries but pregnancy outcome was the same in both groups.

Adult↗
PubMed1997

Follicular density in ovarian biopsy of infertile women: a novel method to assess ovarian reserve.

The ageing ovary appears to be characterized by depletion of primordial follicles. The relationship between infertility and the number of follicles in the ovarian cortex is not known. Moreover, there are no accurate markers or clinical methods to predict the decline in ovarian reserve. This study investigates the correlation between early follicular follicle stimulating hormone, ovarian size and follicular density in 60 infertile women aged 19-45 years (mean = 34.4 +/- 5.5). An ovarian biopsy was taken from each patient while performing diagnostic laparoscopy (n = 28) or laparotomy for tubal surgery or myomectomy (n = 32). The median number of follicles was similar in tubal and unexplained infertility patients (9.5 versus 5.5). Increasing age showed a significant negative correlation with follicular density and ovarian volume (r = -0.46, P = 0.0003;. r = -0.43, P = 0.0016, respectively). In women > or = 35 years of age the ovarian volume showed a strong correlation with follicular density (r = 0.71, P < 0.0001). Our results indicate that infertile women in their late thirties and over have a decreased ovarian reserve which could possibly be predicted by ovarian volume measurement. Ovarian biopsy may have a place as part of infertility evaluation in older women.

Adult↗
PubMed1997

Right or left ovary--which one is better?

This study tests the hypothesis that there is a different response after gonadotrophin-releasing hormone and human menopausal gonadotrophins (GnRH/HMG) stimulation for in-vitro fertilization (IVF) in patients with either a right or left ovary. A total of 56 cycles in 44 women after left oophorectomy (group A) was compared with 42 cycles in 29 women following right oophorectomy (group B). Tubal disease was the sole cause of infertility in all cases. The two groups were similar in age. There was no difference in total amount or days of HMG required for ovulation induction, peak oestradiol concentrations, number of oocytes retrieved and fertilization rate. The pregnancy rate was identical in the two groups (20.0 and 20.9% respectively). Our results indicate that with GnRH/HMG ovulation induction protocol for IVF there is no predilection of one ovary over the other.

Adult↗