The upper tracing is EEG, and the lower is a 10 Hz timing signal. Swartz in Electroencephalography and Clinical Neurophysiology. InPolish physiologist Adolf Beck published an investigation of spontaneous electrical activity of the brain of rabbits and dogs that included rhythmic oscillations altered by light.
This chapter uses the term luteal phase deficiency LPD. Although it successfully can be argued that LPD is the most common abnormality of the menstrual cycle, its significance as a disease entity is shrouded in controversy over its incidence, means of diagnosis, and legitimacy of treatment.
Since the first formal description of LPD in as a possible cause of infertility and recurrent miscarriage by Jones, 1 innumerable investigations have been undertaken in an effort to verify its existence or to characterize its pathophysiology, diagnosis, and treatment.
The consensus of the literature is that LPD does exist and that its cause is multifactorial e. These possible causes are not mutually exclusive in individual patients with LPD, which adds more fuel to the controversy. Obscuring the issue further are related syndromes, such as hyperprolactinemia and hypothyroidism, that are associated with LPD and may induce luteal phase abnormalities secondarily in the presence of otherwise normal ovarian and endometrial function.
The most problematic aspect of a review of LPD is the persistent lack of universal standards for definition and diagnosis.
Jones 1 claimed that the most accurate means of diagnosis was performing daily assays of serum progesterone throughout the luteal phase but noted that this is impractical except in a research setting. Divergent opinions persist regarding the clinical gold standard for measurement of LPD; this has led to tremendous variability in the estimated prevalence and cure rates in infertile populations.
This chapter reviews seminal points regarding LPD that have been reported in a wide variety of investigations. LPD is relevant in the clinical setting only if it is present in most menstrual cycles in a patient.
The requirement for two consecutive menstrual cycles, as currently applied to the diagnosis of LPD, is arbitrary. In the case of LPD, in which the diagnosis has been based variably on single or multiple serum progesterone measurements, urinary progesterone metabolites, salivary progesterone levels, and endometrial histology, the true prevalence is in dispute.
Estimating the incidence of LPD in a normal, fertile population is extremely difficult because of the apparently sporadic nature of the disorder. Much of the difficulty centers around the circular pattern of verification of one test by comparison with another unproven test with inherent and immeasurable bias.
Also, there is a lack of uniformity of the standards for specific tests used for diagnosis e. Despite these obstacles, several reports in the medical literature have attempted to provide estimates of prevalence. Using similar methods, Balasch and Vanrell 4 found that The latter authors noted that these results were supported by findings of other studies, 56 despite failing to account for differences in the definition of an out-of-phase biopsy specimen.
Investigation into the exact incidence of LPD in the general population has proved to be equally elusive. A study of otherwise normal, ovulatory women undergoing tubal anastomosis or donor insemination revealed no cases of retarded endometrium on biopsy, however.
The incidence of LPD also may be influenced by the presence of mitigating factors, such as dieting, 13 recent childbirth, 14 lactation, 15 extremes of reproductive age, 161718 exercise, 19 endometriosis, 720 unexplained infertility, 7 and hyperprolactinemia Fig.
Luteal phase deficiency LPD has been noted to occur more frequently in association with certain normal life events. Menstrual cycles in early postmenarche or late premenopause reproductive age more frequently exhibit LPD. This lack of a consensus was addressed by a symposium of international experts, with the following two generalized conclusions regarding the incidence of LPD: Second, although normal women sporadically have deficient luteal production of progesterone, infertile women with LPD experience it in most of their spontaneous menstrual cycles.
By cycle day 7, usually a single dominant follicle emerges as the major source of circulating estradiol Fig. The microstructure of this dominant follicle comprises an inner layer of granulosa cells, whose aromatase activity converts ovarian androgens to estrogens.
The androgens that originate in the outer thecal layer of cells diffuse into the inner granulosa layer. With the estradiol peak and the LH surge at mid cycle, angiogenic factors, such as vascular endothelial growth factor, cause extension of blood vessels past the defunct basement membrane into the previously protected granulosa layer, providing cholesterol substrate attached to low-density lipoproteins LDLs for progesterone production Fig.
By this point in the cycle, granulosa cells that previously produced only low levels of progesterone have acquired LH receptors under the influence of FSH. In the luteal phase, under the stimulatory influence of pulsatile LH in nonconceptive cycles or human chorionic gonadotropin hCG from the early embryo and trophoblast in conceptive cycles, the corpus luteum continues to produce and secrete progesterone and other hormones e.
The process by which a single follicle is recognized becomes dominant and achieves ovulation occurs over the 14 days from onset of menses to the ovulatory event. The initial phase is recruitment, in which many follicles are stimulated by FSH.
By about day 5 to 7, a single follicle has been selected as the one that proceeds to ovulation.Chiropractic is a form of alternative medicine mostly concerned with the diagnosis and treatment of mechanical disorders of the musculoskeletal system, especially the spine.
Proponents claim that such disorders affect general health via the nervous system, through vertebral subluxation, claims which are demonstrably srmvision.com main chiropractic treatment technique involves manual therapy.
Additionally, one of the most troubling aspects of assisted suicide is the physician’s subjective interpretation of the facts. In all proposed legislation to legalize assisted suicide, a physician must determine that a terminally ill patient is competent. Get the latest news and analysis in the stock market today, including national and world stock market news, business news, financial news and more.
As a follow-up to Tuesday’s post about the majority-minority public schools in Oslo, the following brief account reports the latest statistics on the cultural enrichment of schools in Austria. Vienna is the most fully enriched location, and seems to be in roughly the same situation as Oslo.
Many thanks to Hermes for the translation from srmvision.com Physician Assisted Suicide: A Controversial Topic Words Feb 2nd, 6 Pages It was originally thought to be entirely cruel and immoral, but, as time has passed and medical ethics have been considered, it has slowly gained acceptance.
CME, MOC and Meetings. Earn your CME from the convenience of your home or office by accessing ACG's web-based educational programs, or attend one of ACG's regional or national meetings and Annual Postgraduate Course, that provide an opportunity to connect with colleagues and discuss the challenges you face in practice and ways to overcome them.