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Biomedical subjects

R M Wynn

Publications and source records attributed to R M Wynn.

At least 55 records · Page 3Linked to original sources
PubMed1981

Ultrastructural changes in endometriotic tissue during danazol treatment.

Electron microscopic examinations were carried out on 29 representative endometriotic glands obtained from 16 biopsies. Patients with endometriosis diagnosed by laparoscopy and confirmed by laparoscopic biopsy prior to hormonal treatment received danazol, 800 mg daily. The tissue samples were obtained after 2, 4, and 6 months of usage of the drug to study the ultrastructural effect of this treatment. The glandular epithelium appeared to be arrested in what looked like the late proliferative stage of the normal menstrual cycle. The ciliated cells remained unchanged for the most part. The findings were correlated with possible effects of danazol on the target tissue, but caution is required in the interpretation of ultrastructural effects of steroids until detailed knowledge of the metabolic pathways is available.

Adult↗
PubMed1981

Ultrastructural studies of the mucosa of the human uterine isthmus.

Transmission electron microscopy and ultracytochemical localization of alkaline phosphatase were employed to compare the glands of the isthmic mucosa with those of the fundal endometrium. Examination of 40 biopsies during various phases of the menstrual cycle and in the postmenopause have demonstrated the features of this transitional mucosa. The cyclic morphologic changes in the isthmus are almost identical with those of the glands of the basalis of the corpus. Alkaline phosphatase was demonstrated consistently on the plasma membranes of the isthmic mucosa but not on those of the glands of the basalis; technical considerations may in part explain these differences. Secretory activity was found in every phase of the cycle. The data from postmenopausal patients suggest the concept of migration of the isthmic mucosa toward the corpus uteri above the internal anatomical os.

Adult↗
PubMed1981

Ultrastructural changes in endometriotic implants during the menstrual cycle.

This report, the first ultrastructural study of endometriotic implants, compares the ectopic endometrium in 14 patients with that found in the uterus. The ultrastructural features of most of the glands of the ectopic endometrium resemble those of the corresponding glands lining the uterus. Specific ultrastructural characteristics associated with ovulation, such as giant mitochondria and nuclear channel systems, however, could not be detected in ectopic tissue. Although no pathognomonic electron microscopic characteristics were found in the ectopic endometrium, it was generally possible to assign each sample to a particular phase of the menstrual cycle.

Cell Membrane↗
PubMed1979

Ultrastructural alterations in mammary glands of pregnant rats after ovariectomy and hysterectomy: effect of adrenal steroids and prolactin.

Pregnant rats were subjected to oophorectomy and hysterectomy (O-H) on the seventeenth day of pregnancy, a time when serum levels of prolactin, estrogen, and corticosterone are not substantially greater than the respective levels in nonpregnant rats. At 32 hours after O-H, serum prolactin and corticosterone both rose more than threefold, and lactose appeared in the mammary glands. Biopsies of mammary tissue obtained at 8 hour intervals after O-H showed a progressive secretory response over 16 hours, similar to that previously shown to occur within a period of about 4 hours on the last day of pregnancy. Suppression of serum prolactin by ergocriptine administration and adrenalectomy 24 hours before O-H each prevented the secretory response. However, some differences in the effects of deprivation of the two types of hormones were evident. After cortisol acetate administration at O-H, mammary tissue responded rapidly despite adrenalectomy 24 hours earlier. It is concluded that simple withdrawal of progesterone is not sufficient to initiate lactation in the pregnant rat; glucocorticoids must be present continuously during progesterone withdrawal, and prolactin elevation and other factors present at parturition may be required as well.

Animals↗
PubMed1978

Effects of monitoring high-risk pregnancies and intrapartum FHR monitoring on perinates.

A protocol of chronic antepartum surveillance was initiated at the University of Illinois hospitals in 1973 to assess the impact on perinatal mortality. At the same time, a policy of unselected fetal heart rate (FHR) monitoring was initiated to judge the effect on the intrapartum stillbirth rate. The impact of both programs played a significant role in the decline of perinatal mortality rates for infants weighing more than 1 500 g, from 21.1/1 000 births in 1970--1971 to 14.4/1 000 births in the monitored years 1973 and 1974 (p less than 0.02).

Amniotic Fluid↗
PubMed1976

Interaction of progesterone and adrenocorticoids in ultrastructural development of the mammary gland of the cat.

Comparative development of rough endoplasmic reticulum (RER) in mammary glands of rats was studied in relation to levels of progesterone and adrenocorticosteroids. The tranquilizer perphenazine was administered to stimulate secretion of prolactin; serum glucocorticoids also increased. When perphenazine was administered after ovulation, serum progesterone was increased 18-fold, but when treatment was begun on proestrus, ovulation was inhibited and serum progesterone increased only 4-fold. Concentrations of progesterone in the breast were approximately 10-fold greater than, but parallel to, serum concentrations. In ovulating rats the RER was poorly developed. In nonovulating rats extensive development of RER occurred. Cortisol acetate given to ovulating, perphenazine-treated rats did not alter levels of serum progesterone, but tissue progesterone was reduced by 50 per cent and development of RER approached that in nonovulating rats. The development of secretory capacity (formation of RER) in the breast appears to depend on the relation between stimulation by glucocorticoid and inhibition by progesterone.

Adrenal Cortex Hormones↗
PubMed1975

Electron microscopy of the placenta and related structures of the marmoset.

The marmoset has recently become an important animal in oncologic research, especially with respect to herpes deoxyribonucleic acid viral tumors. As a prototype of the primitive New World monkey, it is also valuable for the study of primate evolution. For these reasons this ultrastructural description of its placenta is presented, including the first electron micrographs of the basal plate and amnion. The main placental mass is pseudo-labyrinthine, or trabecular. The ultrastructural features of the cellular and syncytial trophoblast and endothelium closely resemble those of higher primates. The junctional region shows numerous clumps of moderately well-differentiated trophoblast, an acellular junctional zone, and a poorly developed decidual reaction. Trabecular connective tissue is sparser and transitional trophoblastic elements are less prominent than those in the human placenta. The amnion is ultrastructurally indistinguishable from that of the higher primates. Although the marmoset's placenta retains certain primitive gross and histologic features, such as the large persistent yolk sac and the trabecular condition, it is ultrastructurally quite similar to that of man.

Amnion↗
PubMed1975

Lactogenesis in the rat: an ultrastructural study of the initiation of the secretory process.

Three specimens were taken from mammary glands of rats killed on the 18th and 21st days of pregnancy and on the 1st day of lactation. Ultrastructural features of the tissue were compared among rats within and between the two stages of development. The similarity among specimens from the same rats made feasible a comparison of serial biopsies obtained every 4 hr, starting on the afternoon of the 21st day of pregnancy. From the 18th to the 21st days of pregnancy, a marked increase in the amount of rough endoplasmic reticulum occurred. The alveolar cells of rats killed on both days and in biopsies obtained at 17 and 13 hr before partuirtion contained abundant small lipid droplets and vacuoles containing many protein granules with little clear fluid (stasis vacuoles). Alveolar lumina were distended with secretion by 17 hr before parturition. Between 8 and 12 hr. before parturition, the accumulated protein and lipid were rapidly extruded from the alveolar cells despite evidence of continued biosynthesis. It is suggested that active transport processes are initiated independently of milk synthesis before parturition.

Animals↗