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Biomedical subjects

D Ayalon

Publications and source records attributed to D Ayalon.

At least 37 records · Page 2Linked to original sources
PubMed1993

Another look at co-treatment with growth hormone and human menopausal gonadotrophins in poor ovarian responders.

The objective of this study was to evaluate whether a combined human growth hormone (HGH) and human menopausal gonadotrophin (HMG) treatment can improve ovulation induction in poor ovarian responders. Ten patients aged 28-43 years and requiring > 25 ampoules of HMG for ovulation were admitted to the study. Pituitary growth hormone reserve was evaluated by clonidine stimulation and insulin tolerance tests before commencement of treatment. The patients underwent one treatment cycle with D-tryptophan-6-luteinizing hormone-releasing hormone (D-Trp6-LHRH) and HMG and another cycle with D-Trp6-LHRH, HMG and HGH. Serum HGH, insulin-like growth factor (IGF)-I and oestradiol were measured throughout the two treatment cycles and follicular maturation was assessed by ultrasonographic studies. All patients tested showed no elevation of their serum HGH concentration during a clonidine test, but showed an adequate response during insulin tolerance tests. No significant difference was found in the number of HMG ampoules, duration of treatment, number of leading follicles, and serum oestradiol concentration between the two treatment cycles. Co-treatment with HGH and HMG did not improve ovarian performance in poor ovarian responders. No correlation was found between the results of HGH pituitary function tests and the ovarian response to gonadotrophins.

Adult↗
PubMed1993

Inhibitory effect of a highly potent antagonist of LH releasing hormone (SB-75) on the pituitary gonadal axis in the intact and castrated rat.

The biological potency of the new, highly potent antagonist [AC-D-Nal (2)1, D-Phe(4Cl)2, D-Pal(3)3, D-Cit6, D-Ala10] LH-RH (SB-75) on the pituitary-gonadal system of female castrated and intact ovulating rats was tested. Administration of a single dose (50-100 micrograms/kg BW) of the antagonist SB-75 inhibited effectively the elevated gonadotrophin levels for 48 h. Pituitary LH and FSH content was not affected by SB-75 treatment. When administered in the early afternoon of the proestrus to intact cycling rats, SB-75 blocked the preovulatory LH surge as well as the primary and secondary FSH surges. However, the secondary FSH surge was not affected by SB-75 treatment when administered on the evening of proestrus suggesting its independence from the LH-RH mechanism. A group of ovariectomized rats was chronically treated with D-Trp6-LH-RH after having been pretreated by administration of a single dose of the antagonist. The initial stimulatory release of LH and FSH initiated by injection of the LH-RH agonist was significantly reduced by pretreatment with the LH-RH antagonist. We conclude that the LH-RH antagonist SB-75 may be used effectively in the field of reproductive dysfunction and endocrinological oncology and may become an invaluable physiological probe in studying the hormonal dynamics of the reproductive endocrine axis.

Animals↗
PubMed1993

The effect of the hypoestrogenic state, induced by gonadotropin-releasing hormone agonist, on Doppler-derived parameters of aortic flow.

The effect of the hypoestrogenic state, induced by a GnRH agonist (GnRH-a), on cardiac function in healthy young women, was evaluated by Doppler echocardiography performed before treatment and when serum 17 beta-estradiol levels were suppressed by GnRH-a to 36.7 pmol/L. The following parameters of aortic flow were measured: peak flow velocity, ejection time, and acceleration time. Additional parameters calculated were flow velocity integral, cardiac index, and mean acceleration. The study group included 15 menstruating women, aged 25-42 yr (mean, 33 yr), with symptomatic fibroids, endometriosis, or scheduled for in vitro fertilization, who were treated with a GnRH-a. There were significant decreases in peak flow velocity (99 +/- 11 vs. 86 +/- 11 cm/s; P = 0.0004) and cardiac index (3.0 +/- 0.7 vs. 2.5 +/- 0.5 L/min.m2; P = 0.002). A decrease that did not reach statistical significance was noted in flow velocity integral (18.9 +/- 2.7 vs. 16.5 +/- 3.4 cm; P = 0.07). Mean acceleration was decreased significantly (12.6 +/- 2.6 vs. 10.8 +/- 1.8 m/s.s; P = 0.01), but no significant changes in acceleration time (81 +/- 16 vs. 83 +/- 10 ms; P = 0.7) or ejection time (296 +/- 25 vs. 295 +/- 27 ms; P = 0.8) were observed. These results indicate that estrogen deprivation is associated with smaller stroke volume and flow acceleration and might suggest that hypoestrogenism has a direct effect on cardiovascular performance.

Adult↗
PubMed1992

Calcium homeostasis, bone metabolism and safety aspects during long-term treatment with a GnRH agonist.

Thirty-five women with symptomatic fibroids were treated with monthly injections of 3.2 mg microcapsulated D-Trp-6-LHRH for 6 months. During treatment serum 17 beta-oestradiol levels decreased, falling to castration levels associated with a reduction in the volume of the fibroids. In 16 patients a complete calcium homeostasis and bone metabolism work-up was carried out during treatment and subsequently for a 6-month follow-up period. Bone mineral content (BMC) and Compton bone densitometry readings remained unchanged. There were significant increases in serum calcium phosphate and alkaline phosphatase concentrations. A slight although not significant increase was observed in osteocalcin and parathyroid hormone (PTH) serum levels. Serum 1,25(OH)2D3 values decreased significantly after 3 months of treatment. Urinary hydroxyproline/creatinine and calcium/creatinine ratios as well as 24-h urinary calcium values increased significantly during the treatment period but decreased rapidly to pretreatment values after 3 months in the follow-up period. The endocrine changes induced by the GnRH-agonist treatment were associated with reversible biochemical signs of increased bone turnover and no significant changes in bone mass, suggesting that the treatment can be administered safely for a period of 6 months in patients with oestrogen-dependent diseases.

Adult↗
PubMed1992

Digital road mapping image--a novel fluoroscopic real-time guide for selective transcervical catheterization in the treatment of proximal tubal obstruction.

Ten infertile women 20 to 40 years of age, with a standard HSG diagnosis of unilateral proximal tubal obstruction, underwent a transvaginal catheterization and recanalization of the fallopian tubes. To set a fluoroscopic real-time guidance technique for improving the results of transvaginal catheterization and recanalization of the fallopian tubes and to increase its marginal safety, catheterization was performed under digital road mapping guidance. Transcervical catheterization resulted in an immediate patency of the obstructed tube in all 10 women. Three women conceived 2 to 3 months after the procedure. The improved catheterization technique enables good results in the diagnosis and treatment of proximal tubal obstructions.

Adult↗
PubMed1992

Menopause-related changes in left ventricular function in healthy women.

Using technetium scans, this study was aimed at examining possible changes in left ventricular function related to the natural process of cessation of ovarian estrogen production. Fourteen healthy postmenopausal women, divided into two groups according to the time-lapse from menopause (A > 3 years; B < 5 years), underwent a technetium heart scan. The two groups did not differ in heart rate, blood pressure, double product, systemic vascular resistance and cardiac index. The mean end-systolic volume in group A was 14.9 and 25.7 ml/m2 in group B (p = 0.003). The mean pressure/volume ratio was significantly higher in group A than in group B (8.6 vs. 4.7 mm Hg/ml/m2, p = 0.02). Peak ejection rate and peak filling rate were also significantly greater in group A compared to group B (3.3 vs. 2.8 end-diastolic volumes/s, p = 0.02; 2.8 vs. 2.1 end-diastolic volumes/s, p = 0.001, respectively). Our findings suggest that women at an early phase of menopause have a higher degree of myocardial contractility than women of a similar age whose menopause is of longer duration.

Female↗
PubMed1992

Long-term effects of hormone replacement therapy on Doppler-derived parameters of aortic flow in postmenopausal women.

Eighteen postmenopausal women were examined by Doppler echocardiography before initiation of HRT (T1), then after ten weeks (T2) and one year (T3). This study group was compared with another in which HRT was not used. Flow velocity integral, which correlates with SV, and MA, an indicator of cardiac contractility, were calculated. In the study group, PFV was 107 +/- 18 cm/s at T1 and increased significantly at T2 and T3. Ejection time, which was prolonged at T2 compared to T1, returned to its basal value at T3. Flow velocity integral increased at T2, but this change was only partially sustained at T3. Mean acceleration maintained its increase throughout T2 to T3. None of the Doppler parameters showed a significant change in the controls from T1 to T3. Our results suggest that the peripheral hemodynamic effects of HRT, such as vasodilatation, are transient, whereas the central effects (increased inotropism) are long-lasting.

Aorta↗
PubMed1991

Is idiopathic atrial fibrillation caused by occult thyrotoxicosis? A study of one hundred consecutive patients with atrial fibrillation.

In this study we evaluated the possible relationship between idiopathic atrial fibrillation and occult thyrotoxicosis, diagnosed by lack of response of thyroid stimulating hormone to administration of thyrotropin releasing hormone. Three groups were compared: 25 patients with idiopathic atrial fibrillation; 52 with cardiovascular atrial fibrillation; and 27 with sinus rhythm. Patients were excluded with any clinical evidence of thyrotoxicosis or with elevated serum FT4 level, as well as those with diseases or on medications known to be associated with a diminished response to administration of the releasing hormone. A flat test (lack of response) was found in only 4% of the patients. There was no significant difference among the 3 groups. Based on these data we believe that there is no relationship between idiopathic atrial fibrillation or any other type of atrial fibrillation and occult thyrotoxicosis.

Adult↗
PubMed1989

Changes in prostate-specific markers under chronic gonadotrophin-releasing hormone analogue treatment of state D prostatic cancer.

Nineteen patients with newly diagnosed advanced prostatic carcinoma were treated with daily inhalations of a gonadotrophin-releasing hormone (GnRH) analogue (buserelin acetate, Hoechst 766, Frankfurt, FRG), for up to 3 years. Successful long-term suppression of luteinizing hormone (LH) and testosterone was observed without any escape of testosterone. Ten patients were considered nonresponders, whereas nine were defined as responders (had either stabilized or regressed). Serum prostate-specific markers, prostatic acid phosphatase (PAP) and prostate-specific antigen (PSA), were monitored at fixed time intervals throughout treatment in these patients. Simultaneous determinations of both markers was made under treatment in 147 samples. The results suggest a high correlation between the disease state and the level of the markers (P less than 0.0001), as well as a very high correlation between serum concentrations of the markers themselves (correlation coefficient = 0.6). Thus, the authors could not point clearly towards a superiority of any marker when monitoring response to GnRH analogue treatment. Contrary to current belief, the pretreatment values of both markers were of no prognostic value with regard to response or survival.

Acid Phosphatase↗
PubMed1989

Effect of guanine nucleotides on phospholipase C activity in permeabilized pituitary cells: possible involvement of an inhibitory GTP-binding protein.

Cultured pituitary cells prelabeled with myo-[2-3H] inositol were permeabilized by ATP4-, exposed to guanine nucleotides and resealed by Mg2+. Addition of guanosine 5'-0-(3-thio triphosphate) (GTP gamma S) to permeabilized cells, or gonadotropin releasing hormone (GnRH) to resealed cells, resulted in enhanced phospholipase C activity as determined by [3H] inositol phosphate (Ins-P) production. The effect was not additive, but the combined effect was partially inhibited by guanosine 5'-0-(2-thiodiphosphate) (GDP beta S) or by neomycin. Surprisingly, addition of GDP beta S (100-600 microM) on its own resulted in a dose-related increase in [3H]Ins-P accumulation. Several nucleoside triphosphates stimulated phospholipase C activity in permeabilized pituitary cells with the following order: UTP greater than GTP gamma S greater than ATP greater than CTP. The stimulatory effect of UTP, ATP and CTP, but not GTP gamma S or GDP beta S, could also be demonstrated in normal pituitary cells suggesting a receptor-activated mechanism. GTP and GTP gamma S decreased the affinity of GnRH binding to pituitary membranes and stimulated LH secretion in permeabilized cells. These results suggest the existence of at least two G-proteins (stimulatory and inhibitory) which are involved in phospholipase C activation and GnRH action in pituitary cells.

Animals↗
PubMed1989

IVF-ET in women with refractory polycystic ovarian disease.

Polycystic ovarian disease may be a cause of hormonal infertility. This condition is often refractory to therapy. Three groups of randomly chosen women with refractory polycystic ovarian disease (PCOD) were treated by induction of ovulation with pFSH/hCG, pFSH/hMG/hCG or after down-regulation of the ovaries with a GnRH analogue (Decapeptyl). Out of 18 patients six conceived in the first in vitro fertilization-embryo transfer (IVF-ET) cycle, and two further women conceived in a later cycle. It is suggested that patients with refractory PCOD should be referred for IVF-ET therapy, possibly after treatment with a GnRH analogue.

Adult↗
PubMed1989

Suppressive activity of alveolar macrophages and blood monocytes from interstitial lung diseases: role of released soluble factors.

Two groups of patients suffering from interstitial lung diseases (ILD) namely sarcoidosis (SA) and idiopathic pulmonary fibrosis (IPF) were investigated for alveolar macrophages (AM), secretion of prostaglandin E2 (PGE2) and interleukin 1 (IL-1), together with superoxide anion (O2-) production. Peripheral blood monocytes (PBMO) of the same patients were examined concomitantly for suppressive activity. Consistent with previous results, AM obtained by bronchoalveolar lavage (BAL) from ILD patients markedly suppressed the effects of PHA stimulation of autologous peripheral blood lymphocytes (APL): 61.8 +/- 9.7% suppressive activity compared to 15.5 +/- 15.4% in the control group (CO) P less than 0.001. The AM suppressive activity was correlated with an increase in PGE2 secretion: 3.861 +/- 2.194 ng/10(5) cells/ml in the IPF group, but not in the sarcoid group: 0.217 +/- 0.116 ng/10(5) cells/ml (P less than 0.001 between them). On the other hand, IL-1 secretion by AM was greatly increased in sarcoid patients (308 +/- 196 U/ml) but was within the normal limits in IPF (27.3 +/- 28.8 U/ml, P less than 0.01 between them). Therefore, an inverse correlation was found between degree of PGE2 secretion and IL-1 release by AM in ILD. O2-production by AM was markedly increased in all ILD patients but this mechanism is apparently not involved in suppressive activity. PBMO originating from ILD patients were less suppressive than the corresponding AM.

Adult↗
PubMed1989

Pregnancy outcome in luteinizing hormone-releasing hormone induced cycles: a multicentre study.

In a retrospective international study 223 pregnancies induced with pulsatile hormone-releasing hormone (LH-RH) were evaluated. In patients with hypothalamic amenorrhea (HA) and polycystic ovarian disease (PCOD) the abortion rate was similar (10% vs 8.7%). The premature delivery rate was significantly higher, however, in the patients with HA, but this could be explained by the higher incidence of multiple pregnancies in this group. Thirty multiple pregnancies were observed in the HA group (n = 174) compared with none in the PCOD group (n = 24; p less than 0.05). The incidence of multiple pregnancies in the HA group correlated to the pulse dose (p less than 0.05). The 1st treatment cycle resulted in more multiple pregnancies than did subsequent cycles (p less than 0.05). Difference in pulse interval did not affect the incidence of multiple pregnancies, nor did the route of administration (intravenous or subcutaneous). The incidence of congenital anomalies was comparable to that with spontaneously achieved pregnancies.

Adult↗