Biomedical subjects
Publications and source records attributed to J Schoemaker.
Clinical and cytogenetic findings in three patients mosaic for sex chromosomes (45,X0/46,XY; 45,X0/46,XY/46,XYq-, and 45,X0/46,XY/46,XYY), each with a nonfluorescent Y, are presented. Hypotheses for the origin and effect of these chromosome constitutions are discussed.
Ovarian follicular growth was stimulated in 4 patients with clomiphene resistant polycystic ovary (PCO)-like disease, with "pure" human pituitary FSH during 10 cycles. In 8 cycles additional hCG was given to induce ovulation. Serum LH and FSH and plasma estradiol and progesterone were determined daily. From the response patterns of steroidogenesis, four functional stages of follicular development can be distinguished, each subsequent stage being characterized by an increasing spontaneous estradiol production and a decreasing capacity to produce extra estradiol in response to stimulation with additional hCG. It is concluded that the unpredictable response to gonadotropin stimulation of patients with PCO-like disease is due to the varying state of development of the follicles at the start of the stimulation. The suggestion is made, based on the different responses in 3 cycles of the same patient (EW), that the lack of positive estrogen feedback in patients with PCO-like disease may be a hyposensitivity to estrogens rather than an absolute insensitivity.
Patients with primary amenorrhea underwent stimulation with luteinizing hormone releasing hormone (LRH) before and after clomiphene administration to determine the maturational status of the hypothalamic-pituitary-gonadal axis, and to assess the development of feedback control mechanisms. Four patients with clinically recognizable conditions served as models. One patient had panhypopituitarism with undetectable baseline FSH and LH values, no response to LRH or clomiphene, and no detectable feedback control. One patient with a "specific" hypothalamic hypogonadotropism had low baseline gonadotropins with a normal response to LRH and no positive or negative feedback mechanisms reflected by no change in LRH response after clomiphene. A patient with delayed puberty due to low bodyweight had low FSH and LH baseline values and an "immature" response to clomiphene, characterized by lowered baseline gonadotropins and an increased peak LH following LRH stimulation. The fourth patient, with an adolescent polycystic ovarian syndrome, had a high baseline LH, normal FSH, hyperresponse to LRH, and a "mature feedback control" as evidenced by an increase in baseline FSH and LH, and a decrease in the LRH response while on clomiphene. The remaining patients showed inappropriate responses. They are regarded as having defects rather than dysfunctions, and the possible abnormalities are discussed in relation to the clinical findings.
A Medical Information System for the Fertility Department has been built (VERGYNIA) using the 4th generation software package AIDA to make the medical data accessible for research and teaching on the one hand and to assist the management of the department in the daily routine of patient care on the other. The system has been implemented on a PDP 11/23 computer with a 20 Mbyte hard disk, a 10 Mbyte removable disk and 128 Kbyte central memory. Three visual display terminals and a small printer are connected to the system. A dedicated line connection between this system and the computer facilities of the Department of Medical Informatics allows easy transfer of data for analysis by statistical packages and the transfer of new programs to the computer of the Fertility Department. The PDP 11/23 contains a production system, a developmental system, and a separate environment for research which can all three run simultaneously on the same computer without interfering with each other. VERGYNIA was predominantly constructed with AIDA; only parts of the output programs have been programmed in MUMPS, due to the fact that the required AIDA tools were not yet available at the time of development. The original version of VERGYNIA was already in operation in 1982 and was built with the tools that form the basis of the current AIDA release. Due to many ad hoc modifications and additions, the system needed a total redesign in order to make it compatible with the new enhancements of the current AIDA release. This redesign was carried out during 1985.
Infertility is an important issue for patients with premature ovarian failure (POF). Although oocyte donation offers an alternative method to achieve a pregnancy, many patients seek to reproduce with their own gametes. We performed a literature search to evaluate the possibility of pregnancy following diagnosis, and the additional value of treatment strategies. We found 52 case reports, eight observational studies, nine uncontrolled studies and seven controlled trials. Due to a strong variability in study design, patient selection and mode of intervention, it was not possible to combine the data of the seven studies to perform a meta-analysis. None of the studies showed a statistically significant difference between both (or more) study groups. Due to a lack of incorporation of a placebo group, preference of any treatment over no treatment could not be established. Importantly, the collected data of observational, uncontrolled and controlled studies indicate that POF patients still have a 5-10% chance to conceive following diagnosis. Approximately 80% of the reported pregnancies resulted in the birth of a healthy child. There is no evidence that any treatment can enhance this pregnancy rate.
In in-vitro fertilization programmes, gonadotrophin releasing hormone (GnRH) agonists are now routinely used in order to prevent the undesired pre-ovulatory spontaneous luteinizing hormone surge. The first publications are now appearing in which GnRH antagonists are used with the same purpose. More attention should be addressed to the safety aspects of these drugs. This review aims to summarize studies on direct ovarian effects of GnRH agonists and GnRH antagonists in non-primates and primates with respect to the functional and morphological aspects in-vitro as well as in-vivo. We conclude that there is a wide variety of functional and morphological effects of GnRH analogues on the ovary. The sometimes paradoxical effects indicate that a variety of factors may be involved in the various processes. Those factors are: (i) the type and dose of the analogue, (ii) the different regimens of administration, (iii) ovarian status at the time of exposure, (iv) ovarian cell types in in-vitro systems, (v) hormonal pre-treatment of these cultures, (vi) the type of hormonal stimulation added to the in-vitro culture, (vii) further methodological differences in the experiments and finally (viii) physiological variations in GnRH receptor abundance which depends on species and/or timing in the cycle. With the increasing number of patients using GnRH analogues in assisted reproduction treatments, there will be an increasing number of pregnancies exposed to these drugs. So far, there does not appear to be an increased risk of birth defects or pregnancy wastage in human pregnancies exposed to daily low-dose GnRH agonist therapy in the first weeks of gestation.
Corticotropin Releasing Factor (CRF) immunoreactivity was localized within the rat central nervous system with immunocytochemical methods, using a highly specific anti-serum to rat-CRF. In adult rats abundant CRF immunoreactivity (CRF-ir) was found in perikarya of the inferior olivary nucleus, in climbing fibres in the molecular layer, and mossy fibres in the granular layer of the cerebellum and in the cerebellar nuclei. CRF-ir climbing fibres were found in a longitudinal zonal pattern throughout the molecular layer. In developing cerebellum only a few CRF-positive fibres were seen on postnatal day 8. From day 8 onwards a gradual increase in CRF-ir was found in both the molecular and granular layer with formation of CRF-positive nests around Purkinje cellbodies starting at day 12. Subsequent outgrowth into the molecular layer could be followed, leading to an adult level of CRF-ir in the cerebellum at approximately day 22 postnatally. CRF-ir in mossy fibres has as adult appearance from approximately day 18. The temporal and morphological changes of CRF-ir in fibres in the cerebellum of immature rats followed closely the morphological development of climbing and mossy fibres. The present findings indicate that CRF (or related substances) are already present in both climbing and mossy fibres during their outgrowth into the cerebellum.
Contraceptive use, source of contraception, history of abortion, current pregnancy intention, and fertility rates are evaluated for a national sample of women using data from the Paraguay Contraceptive Prevalence Survey, conducted in 1977. The survey found that 15.5 percent of all women aged 15--44 and 23.6 percent of ever-married women were using effective contraceptive methods. The urban/rural difference in contraceptive use paralleled fertility differentials: over 40 percent of ever-married women were using contraception in Greater Asuncion and other urban areas compared with 15 percent in rural areas. Overall, the data indicate that high-parity rural women have the greatest need for family planning services in Paraguay.