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Bruno Lunenfeld

Publications and source records attributed to Bruno Lunenfeld.

10 recordsLinked to original sources
PubMed2004

Historical perspectives in gonadotrophin therapy.

The 20th century witnessed the steady development of knowledge about the reproductive process in animals and humans. These advances led to the identification of higher centres governing the dynamics of ovarian function and to the discovery of gonadotrophic hormones. As the mechanisms of action of these hormones became increasingly understood, they began to be used in the management of infertility during the early 1930s. Hormone extracts were originally prepared from animal pituitaries and pregnant mare serum, as well as from human pituitaries, placenta and urine, with pregnancies reported following their use in the late 1930s. This review traces the constant quest to reduce risks and improve safety and efficacy of hormone preparations for patients. It describes the complex path and perils leading to the pure hormone preparations that are available today, concluding with an optimistic glimpse towards the future. Small molecules that are orally active and specific are currently being investigated, some with the capacity to bypass many parts of the receptor conformation. Here lies the immediate future of this field, utilizing low-cost, small, defined molecules to stimulate follicle growth, ovulation and corpus luteum formation. Perhaps one day the classical gonadotrophins will no longer be required in clinical treatment.

Animals↗
PubMed2004

Towards less confusing terminology in reproductive medicine: a proposal.

The use of the term 'infertility' and related terms in reproductive medicine is reviewed. Current terminology is found to be ambiguous, confusing, and misleading. We recommend that the fertility investigation report of a couple should consist of statements concerning description, diagnosis, and prognosis. The description concerns the duration of nonpregnancy before consulting the clinician. A system for prognostic grading is proposed. The fertility investigation report forms the basis for further action, including the possibility of waiting with treatment in case of almost normal or only slightly reduced fertility. The use of the terms 'infertility', 'subfertility', and 'fecundity' is not necessary, and it is recommended to avoid them.

Humans↗
PubMed2003

Androgen therapy in the aging male.

The world population is expanding rapidly; at the same time, life expectancy is increasing, and fertility rates are decreasing. Due to these facts, it is expected that the biggest increases of population growth will occur in the aging population. In the aging male, endocrine changes and a decline in endocrine function involve tissue responsiveness as well as reduced secretory output from peripheral glands and alterations in the central mechanism controlling the temporal organization of hormonal release. The latter are likely to be responsible for the dampened circadian hormonal and non-hormonal rhythms. These are in part responsible for the age-dependent decrease of the peripheral levels of testosterone, dehydroepiandrosterone (DHEA), the thyroid hormones, growth hormone (GH), IGF1 and melatonin. These hormonal changes, which develop in most men at about the age of 50, are in part responsible for endocrine deficiencies of some older men. One of the best-studied endocrine deficiencies is late-onset hypogonadism. This is a syndrome characterized by adverse effects on multiple organ systems and decreased quality of life, associated with advancing age and characterized by signs and symptoms of hypogonadism and a deficiency in serum androgen levels with or without a decreased genomic sensitivity to androgens. In cases of endocrine deficiencies, traditional endocrinology aims to replace the missing hormone or hormones with substitutes. It has been demonstrated that interventions such as hormone therapies may favorably influence some of the pathological conditions in aging men by preventing the preventable and delaying the inevitable. A comprehensive medical, psycho-social and life-style history, a physical examination and laboratory testing are essential for the diagnosis and management of late-onset hypogonadism. Acute, chronic or inter-current diseases must be taken into consideration prior to initiating any hormonal substitution therapy. In the era of evidence-based medicine, we have to acknowledge that data on testosterone therapy (HT) in the aging male is mostly circumstantial, based on experience in the treatment of transitional or chronic hypogonadism in young men resulting from disease or experiments of nature. However, over the past several years prospective studies on testosterone therapy in the aging male were performed and shown to be beneficial for certain older men in preventing or delaying some aspects of aging. Recommendations for algorithms for the diagnosis of late-onset hypogonadism and monitoring therapy for safety and efficacy are the subject of this paper.

Age Factors↗
PubMed2002

The ageing male: demographics and challenges.

In the year 2000, there were more than 400 million people aged 65 and over in the world--projected to increase to almost 1.5 billion by the year 2050--a close to fourfold increase compared to the 50% increase for the global population as a whole. More than 25% of these 1.5 billion elderly people are projected to be "oldest-old" (aged 80 and over). Global ageing is a triumph and a challenge. As we enter the 21st century, it will put increased economic and social demands in all countries. But if more and more individuals reach older age in good health--and remain healthy for longer--the benefits will be shared by all. Therefore, the promotion of healthy ageing and the prevention of disability in all older people must assume a central role in medical care and research as well as in the formulation of national health and social policies. Effective programs promoting healthy ageing will ensure a more efficient use of health and social services and improve the quality of life in older persons by enabling them to remain independent and productive. With prolonged life expectancy, men and women can expect to live one-third of their lives with some form of hormone deficiency. Life expectancy differences between men and women exist in various regions of the world with a mean of 4.2 years, and is projected to increase to 4.8 years by the year 2050. The ageing male, in particular, has the risk of developing gender-specific urological diseases, such as prostate cancer, benign prostate hyperplasia continence disorders (generally ignored by men) and erectile dysfunction. Hormonal changes in the ageing male are associated with changes in the body mass index, osteoporosis, and sleep and mood disorders. A significant relationship between body fat mass and both cardiovascular and overall mortality in men has been demonstrated. In some populations, at least, men may run a higher risk for cardiovascular complications than women. It is our sincere hope that the next few years will enrich us with facts and clarify the state of our present knowledge, permit us to recognize some of the missing links, give us the tools and methodology to design and plan ways to understand ageing in men, allow us to help to improve the quality of life, prevent the preventable, and postpone and decrease the pain and suffering of the inevitable.

Aging↗
PubMed2002

Cancer incidence in a cohort of infertile women who underwent in vitro fertilization.

OBJECTIVE: To assess whether ovarian hyperstimulation and IVF increase the risk for cancer. DESIGN: Historical cohort analysis. SETTING; IVF units of two medical centers in Israel. PATIENT(S): Five thousand twenty-six women who underwent IVF between 1981 and 1992. INTERVENTION(S); Cancer incidence rates were determined through linkage to the National Cancer Registry and were compared with expected rates with respect to age, sex, and place of birth. MAIN OUTCOME MEASURE(S): Development of cancer. RESULT(S): Twenty-seven cases of cancer were observed, and 35.6 were expected (standardized incidence ratio, 0.76 [95% CI, 0.50-1.10]). Eleven cases of breast cancer were observed, whereas 15.86 were expected (standardized incidence ratio, 0.69 [95% CI, 0.46-1.66]). One case of ovarian cancer and 1 case of cervical cancer were observed, compared with 1.74 and 1.73 cases expected, respectively. The type of infertility, number of IVF cycles, and treatment outcome did not significantly affect risk for cancer. CONCLUSION(S): In a cohort of women treated with IVF, no excess risk for cancer was noted.

Adult↗
PubMed2002

Ovarian stimulation: from basic science to clinical application.

Treatment for infertility, including ovarian stimulation, was first introduced almost 100 years ago. At this time, radiation therapy became an established treatment, and it was only some decades later that the problem of radiation-induced cancer emerged. Non-human gonadotrophins, such as pregnant mare serum gonadotrophin (PMSG), and human pituitary gonadotrophins (HPG), were commonly used for hormonal stimulation procedures. However, use of PMSG led to antibody formation, and it was therefore only useful for the first treatment cycle. HPG produced good results, but its use came to an end in the late 1980s when it was linked to the development of Creutzfeldt-Jakob disease. The first hormonal product from human menopausal urine to be used was human menopausal gonadotrophin (HMG), followed later by purified preparations of this product. All of these preparations contained a high percentage of unknown urinary proteins, which interfered with batch-to-batch consistency. This changed with the introduction of recombinant gonadotrophins, produced from an immortalized/standardized mammalian cell line (CHO). More recent developments include the introduction of long-acting gonadotrophin formulations. The development of gonadotrophin-releasing hormone (GnRH) analogues and more recently the use of GnRH antagonists has helped to improve ovarian stimulation protocols by optimizing their efficacy, and making them easier to administer.

Animals↗
PubMed2002

Development of gonadotrophins for clinical use.

The 20th century witnessed the steady development of knowledge about reproductive physiology and endocrinology in animals and humans. These advances led to the identification of higher centres governing the ovary and its follicles. Effects of X-rays on the head and other agents, or excision of the pituitary gland, led to anomalies in oestrous and menstrual cycles in animals and women, respectively. Studies on pituitary and placental extracts revealed the presence of hormones regulating the ovarian follicles and the corpus luteum for the implanting embryo. These were identified as follicle stimulating hormone (FSH), luteinizing hormone (LH) and human chorionic gonadotrophin (HCG). Increasing understanding of the mechanisms of action of these hormones led to treatments of animals and amenorrhoeic women with FSH- and LH-containing preparations in order to induce the growth of follicles and ovulation. Human FSH-rich preparations were obtained by extracting urinary gonadotrophins from the urine of post-menopausal women, and thousands of amenorrhoeic and/or anovulatory patients were treated with human menopausal gonadotrophin (HMG) and HCG to induce multifolliculation and ovulation. The introduction of IVF greatly increased the numbers of women treated in this fashion, now including cyclic women. By the mid-1980s, following the appearance of Creutzfeld-Jakob disease in women treated with gonadotrophins extracted from human pituitaries, and other safety considerations, attempts were being made to purify urinary gonadotrophin preparations, using antibodies. Increasing interest in recombinant preparations, which were pure, highly specific and highly active preparations, characterized the last years of the 20th century and the new millennium. These preparations included recombinant FSH (rFSH), recombinant LH (rLH) and recombinant HCG (rHCG). Yet, in one sense, the recombinant preparations could change the procedures of ovarian stimulation, because they focused attention on the membranal receptor in the follicle, and how best to stimulate it. Small molecules are currently being investigated, with some proving to be very active and specific, and even capable of bypassing many parts of the receptor conformation. Here lies the immediate future of this field, utilizing small, defined molecules at low cost to stimulate follicle growth, ovulation and luteinization, and perhaps one day to remove the need for gonadotrophins in clinical work.

Chorionic Gonadotropin↗
PubMed2002

The Aging Male.

Explore the source record for details and available documents.

Aging↗