Perinatal exposure to low doses of bisphenol A affects body weight, patterns of estrous cyclicity, and plasma LH levels.

The nonsteroidal estrogenic compound bisphenol A (BPA) is a monomer used in the manufacture of polycarbonate plastics and resins. BPA may be ingested by humans as it reportedly leaches from the lining of tin cans into foods, from dental sealants into saliva, and from polycarbonate bottles into their contents. Because BPA is weakly estrogenic--approximately 10,000-fold less potent than 17beta-estradiol--current environmental exposure levels have been considered orders of magnitude below the dose required for adverse effects on health. Herein we demonstrate measurable effects on the offspring of Sprague-Dawley female rats that were exposed, via their drinking water, to approximately 0.1 mg BPA/kg body weight (bw)/day (low dose) or 1.2 mg BPA/kg bw/day (high dose) from day 6 of pregnancy through the period of lactation. Offspring exposed to BPA exhibited an increase in body weight that was apparent soon after birth and continued into adulthood. In addition, female offspring exposed perinatally to the high dose of BPA exhibited altered patterns of estrous cyclicity and decreased levels of plasma luteinizing hormone (LH) in adulthood. Administration of neither the doses of BPA that caused effects during perinatal exposure nor a 10-fold higher dose was able to evoke a uterotropic response in ovariectomized postpubertal females. These data indicate an increased sensitivity to BPA during the perinatal period and suggest the need for careful evaluation of the current levels of exposure to this compound.

Morphological features of epithelial cells in the sheep isthmus oviduct during early pregnancy.

BACKGROUND: The objective of the present study was to define the morphological changes that occur in the epithelium of the isthmus oviduct of the sheep during the first few weeks of pregnancy. MATERIALS: Isthmus oviducts were obtained from ovariectomized, estrous (day O) and pregnant (day 2, 3, 4, 6, and 16) ewes and analyzed using light and electron microscopy. RESULTS: The epithelium was low cuboidal in the isthmus from ovariectomized sheep, significantly increased in height at estrus, underwent an additional increase at day 3, and was significantly reduced by day 4 of pregnancy. Ciliated and nonciliated epithelial cells were present at all reproductive stages. Ciliated cells were always the predominant cell type. The percentage of ciliated and nonciliated cells did not significantly change at any stage examined. In addition, a third cell type, located adjacent to the basement membrane, was present. These "basal" cells were rounded in appearance and more frequently observed in the epithelial lining of ovariectomized ewes and after day 3 of pregnancy. The secretory organelles of nonciliated epithelial cells obtained from ovariectomized ewes were poorly developed. In estrous ewes, the Golgi apparatus in nonciliated cells consisted of stacked cisternae that atrophied later in pregnancy. The most striking alterations in the secretory apparatus occurred in ciliated cells. Two populations of ciliated cells were observed at estrus-one with abundant, membrane bound supranuclear granules and one without granules. The granules in ciliated cells were rare after day 3 of pregnancy and no evidence of secretion was ever observed. Large lipid droplets were present in the cytoplasm of ciliated cells at estrus. Lysosomes were abundant in nonciliated cells by day 16 of pregnancy. Regularly arranged microvilli were present in nonciliated cells obtained from ovariectomized, estrous, and pregnant ewes. No appreciable change in nuclear shape or chromatin content was observed at any reproductive stage examined. The ultrastructural characteristics and relative abundance of other cytoplasmic organelles such as the RER, SER, mitochondria, and glycogen varied slightly during pregnancy in ciliated and nonciliated cells. CONCLUSIONS: These data show that the epithelial lining of the isthmus oviduct in the sheep undergoes subtle, yet distinctive, structural changes during the first few weeks of pregnancy.

Novel bifunctional anthracycline and nitrosourea chemotherapy for human bladder cancer: analysis in a preclinical survival model.

A hybrid drug [N-2-chloroethylnitrosoureidodaunorubicin (AD312)] that combines structural and functional features of both anthracyclines and nitrosoureas was evaluated in a preclinical survival model of human bladder cancer. To measure the therapeutic activity of AD312, UCRU-BL13 transitional cell carcinoma cells were grown as xenografts in nude mice, and tumor growth rates were compared after i.v. administration of the drug at three dose levels. AD312 treatment at 45 and 60 mg/kg achieved 7-10-fold inhibition of tumor growth and increased host survival by 156 and 249%, respectively. Doses of 60 mg/kg showed optimal therapeutic efficacy, with sustained tumor growth inhibition, an over 2-fold increase in life span, and 40% of mice tumor free ("cured") at 120 days. Tumors were unresponsive to maximum tolerated doses of doxorubicin, a standard anthracycline used as a single agent and in combination therapies for bladder cancer. 1,3-Bis-[2-chloroethyl]-1-nitrosourea was used as a control for the apparently enhanced response of human tumors in murine hosts to nitrosoureas. 1, 3-Bis-[2-chloroethyl]-1-nitrosourea administered in three injections of 20 mg/kg did not cure mice but temporarily inhibited tumor growth by 70% and prolonged survival by 55%; its activity in this model suggests that it may be included in the repertoire of alkylating agents currently used for treatment of bladder cancers. AD312 showed increased antitumor activity with less toxicity than doxorubicin, and its bifunctional properties provide the opportunity for simultaneous treatment of individual cancer cells with two cytotoxic modalities as well as treatment of heterogeneous populations typical of bladder cancers. This novel cytotoxic drug cured doxorubicin-refractory disease and should be investigated for the clinical management of bladder cancer.

Changes in secretory status, cell height and percentage ciliation of epithelial lining of sheep fimbria oviduct during early pregnancy.

Studies have shown that the biosynthetic activity of the fimbria oviduct in the sheep changes during the first few weeks of pregnancy. The objective of the present study was to determine whether the secretory epithelial lining of the fimbria undergoes pregnancy-associated morphological alterations in a concordant manner. Oviducts obtained from ovariectomized, oestrous (day 0) and pregnant (day 1.5, 2, 3, 4, 6 and 16) ewes were analysed quantitatively and qualitatively using light and electron microscopy. The epithelium was low cuboidal in fimbria from ovariectomized sheep, significantly increased in height at day 1.5 of pregnancy, immediately decreased at day 2, and underwent an additional slight reduction at day 6 and day 16 of pregnancy. Ciliated and nonciliated cells were present in the epithelium at all reproductive stages. The proportions of ciliated and nonciliated cells varied during pregnancy and ciliated cells were always the major cell type. Consistent with previous data, the secretory organelles of nonciliated epithelial cells obtained from ovariectomized ewes were poorly developed. Maturation of secretory organelles in nonciliated cells occurred at oestrus and was maintained until days 2-3 of pregnancy; regressive changes were then observed, characterized by atrophy of the Golgi apparatus and rough endoplasmic reticulum, and increases in heterochromatin and pronounced nuclear folds. Large, electron-dense lipid droplets were present throughout the cytoplasm of ciliated and nonciliated epithelial cells, beginning at day 1.5 of pregnancy and increasing at later stages of pregnancy. Apical protrusions and microvilli were observed at the luminal domains of nonciliated cells and were reduced in extent after day 3 of pregnancy. Cells were extruded from the epithelial lining at day 16 of pregnancy. These data show that the epithelial lining of the fimbria oviduct in the sheep undergoes distinct changes in cell height, percentage ciliation and secretory organelle development during the first few weeks of pregnancy.

An estrogen-dependent sheep oviductal glycoprotein has glycan linkages typical of sialomucins and does not contain chitinase activity.

The deduced amino acid sequence of an estrogen-dependent sheep oviductal glycoprotein (M(r) 90,000-116,000) revealed the presence of several potential sites for glycan substitution on a protein backbone of M(r) approximately 66,500, and identity with chitinases. In order to further define the nature of the secreted glycoprotein, the objectives of the present study were 1) to devise a method to significantly enrich for the glycoprotein from oviductal secretions, 2) to biochemically characterize the glycoprotein by use of lectin blotting and enzymatic and chemical digestion, and 3) to determine whether unfractionated and enriched fractions containing the glycoprotein have chitinase activity. Oviducts were obtained from ovariectomized ewes treated with estradiol for 6 days and explant-cultured for 24 h. The oviductal glycoprotein was enriched approximately 80-85% from explant culture media by Maackia amurensis agglutinin (MAA) lectin affinity chromatography. Enriched fractions containing the oviductal protein were separated on SDS gels, transferred to polyvinyl difluoride, and probed with digoxigenin-labeled lectins. Lectin blotting revealed that the glycoprotein contained the carbohydrate moieties N-acetylgalactosamine, N-acetylglucosamine, galactose, fucose, and sialic acid both in alpha(2,3) and alpha(2,6) linkages, typical of sialomucins. Enzymatic digestion with neuraminidase and N-glycanase indicated that approximately 20% and approximately 6% of the molecular weight of the oviductal glycoprotein can be accounted for by sialic acid and N-linked glycans, respectively. The oviductal glycoprotein was resistant to digestion with O-glycanase alone and chondroitinase ABC, with the latter indicating that it was not a proteoglycan. Treatment with trifluoromethanesulfonic acid resulted in a deglycosylated product of M(r) approximately 66,000 immunoreactive with antibodies to the oviductal glycoprotein. No chitinase activity could be detected for unfractionated culture medium proteins or enriched fractions containing the M(r) 90,000-116,000 oviductal glycoprotein when the substrate methylumbelliferyl chitotriose was used. These data show that 1) MAA lectin chromatography can significantly enrich for the M(r) 90,000-116,000 glycoprotein from oviductal secretions, 2) the secreted glycoprotein contains saccharide residues typical of sialomucins, and 3) despite primary amino acid sequence identity, the oviductal glycoprotein does not share an enzymatic relationship with chitinases.

Messenger RNA encoding an estrogen-dependent oviduct secretory protein in the sheep is localized in the apical tips and basal compartments of fimbria and ampulla epithelial cells implying translation at unique cytoplasmic foci.

Data from our laboratory have shown that an estrogen (E2)-dependent M(r) 90,000-92,000 protein and its mRNA are synthesized and expressed in abundant amounts at estrus from the fimbria and ampulla, not isthmus, oviduct of the sheep. Immunocytochemical studies have shown that the M(r) 90,000-92,000 protein is contained in apical secretory granules of oviduct epithelial cells. The objective of this study was to determine whether the mRNA for the E2-dependent oviduct protein was localized and compartmentalized in similar manner. Fimbria, ampulla, and isthmus oviducts obtained from estrous ewes were flash frozen in liquid nitrogen, cryosectioned, fixed in 4% paraformaldehyde, hybridized with digoxigenin (DIG)-labeled oviduct-specific riboprobes, incubated in anti-DIG antibodies conjugated with alkaline phosphatase, and developed in color substrate. Oviduct protein-specific transcripts were localized to basal perinuclear compartments and, surprisingly, at sites distant from the nucleus in the apical cytoplasm of epithelial cells in the fimbria and ampulla. No specific reaction product was observed in the underlying mucosa or smooth muscle layers. Oviduct protein mRNA was contained predominantly in the apical cytoplasm of epithelial cells at the free margins of mucosal folds and in the basal regions of cells located at the crypts of longitudinal folds. No reaction product was present when sections of the fimbria and ampulla oviduct of estrous ewes were incubated in sense riboprobe to the oviduct protein. In addition, when sections of the isthmus oviduct obtained from estrous ewes or fimbira and ampulla oviducts from long-term ovariectomized ewes were hybridized with antisense riboprobes no specific reaction product was detected. Electron microscopy of oviduct protein mRNA containing areas revealed the presence of secretory granules, rough endoplasmic reticulum (RER) and Golgi in the apical cytoplasm, and RER in the basal regions of epithelial cells. These data show that the mRNA encoding an E2-dependent oviduct-specific protein is distributed in epithelial cells at perinuclear foci and at sites distant from the nucleus, which are also the sites of protein localization and protein synthesizing organelles, implying translation at unique cytoplasmic foci.

Epithelial lining of the sheep ampulla oviduct undergoes pregnancy-associated morphological changes in secretory status and cell height.

The biosynthetic activity of the sheep ampulla oviduct changes during the first few days of pregnancy. An estrogen (E2)-dependent glycoprotein (M(r) 90,000-92,000) is expressed, synthesized, and released when fertilization and embryo development occur in the oviduct. The objective of the present study was to determine whether the secretory epithelial lining of the ampulla, the cellular source of the E2-dependent protein, undergoes morphological alterations during early pregnancy is a contemporaneous manner. Ampulla oviducts obtained from ovariectomized (ovx), estrous (Day 0), and pregnant (Days 1.5, 2, 3, 4, 6, and 16) ewes were analyzed with light and electron microscopy. The mean cell height of epithelial cells from estrus and from Days 1.5, 2, and 3 of pregnancy was significantly (p < 0.05) higher than in ovx animals. A significant reduction in cell height was observed at Day 4 of pregnancy, and this value remained unchanged at Day 6 and Day 16. Ciliated and nonciliated cells were present in the ampulla at all stages examined, with ciliated cells constituting the major cell type. Consistent with previous results, the nonciliated cells obtained from ovx ewes were synthetically inactive and at estrus were characterized by well-developed secretory organelles, including abundant amounts of secretory granules containing the E2-dependent glycoprotein. Extensive microvilli and cytoplasmic blebs protruding into the oviduct lumen distinguished the apical surface of secretory epithelial cells until Day 3. At Day 1.5 the secretory cells contained dilated cisternae of rough endoplasmic reticulum and enlarged Golgi, which were progressively diminished with increasing stages of pregnancy. Exocytosis, fusion of secretory granules, and a reduction in their electron density were seen until Days 3-4. By Day 4 and Day 6, fewer granules were observed in the ampulla cytoplasm and few, if any, were present by Day 16. Increases in the amount of heterochromatin were seen in nuclei at Day 6 and Day 16. Extrusion of epithelial cells into the oviduct-lumen was evident at Day 16 of pregnancy. These data show that 1) the secretory epithelium of the sheep ampulla oviduct undergoes morphological alterations in protein-synthesizing organelles and apical specializations that vary with the stage of pregnancy, 2) the secretory product contained in lamellar granules is released by the process of exocytosis until Days 3-4, and 3) cell death appears to occur at Day 16 by shedding of epithelial cells into the oviduct lumen.

Oviduct during early pregnancy: hormonal regulation and interactions with the fertilized ovum.

The cyclic fluctuations in circulating levels of 17 beta-estradiol and progesterone that occur during the menstrual or estrous cycle are responsible for dramatic, cyclic changes in the epithelial lining and secretory status of the mammalian oviduct. The timely transition in the synthesis and release of oviduct proteins, due to the ovarian steroids, and their interactions with oocytes, sperm, and the fertilized ovum underscore key biological events during gamete interactions and early embryonic cleavage. The regulation of these secretory alterations during the first few days of pregnancy is discussed with respect to the influence of the ovarian steroids, their interactions with the embryo microenvironment, and the possible ways in which they may mediate the critical reproductive events of fertilization and embryo development.

An estrogen-dependent secretory protein, which shares identity with chitinases, is expressed in a temporally and regionally specific manner in the sheep oviduct at the time of fertilization and embryo development.

An estrogen (E2)-dependent 90,000-92,000 M(r) protein is synthesized and released by the sheep oviduct in a temporally and regionally specific manner during the first few days of pregnancy, where it associates with the embryo. The present study was undertaken to further define the nature of this protein and its regulation at a time when fertilization and early embryonic cleavage occur in the oviduct. The complete complementary DNA (cDNA) sequence for the 90,000-92,000 M(r) protein was determined, and steady state messenger RNA (mRNA) levels were measured during early pregnancy (estrus and days 1, 2, 3, 4, 6, and 16). The composite cDNA possessed an open reading frame of 1633 bases with a single potential N-glycosylation site. The inferred amino acid (aa) sequence predicted a prepolypeptide of 539 aa (69,151 M(r)) and a mature polypeptide of 518 aa (66,477 M(r)). Nucleotide and deduced aa sequence shared identity with translated E2-dependent cow, human, and partially sequenced baboon oviduct protein cDNAs; a human articular cartilage protein, gp 39; and chitinases. Northern blot hybridization revealed a single RNA species (2.2 kilobases) in the fimbria and ampulla, which was not detected in the isthmus or other reproductive and nonreproductive tract tissue RNAs. Steady state levels of mRNA encoding the 90,000-92,000 M(r) were highest in the fimbria and ampulla at estrus and on day 1 of pregnancy, when gamete transport and fertilization occur in the E2-dominated fallopian tube. Oviduct protein mRNA levels declined significantly (P < 0.05) on day 2 and underwent a further significant reduction on day 3 of pregnancy coincident with transport of the embryo from the oviduct to the uterus, a reproductive stage associated with rising progesterone levels. By day 16 of pregnancy, the mRNA encoding the E2-dependent oviduct protein was virtually undetectable. The temporally and regionally specific regulation of gene expression for the 90,000-92,000 M(r) E2-dependent protein correlates with protein synthesis data and emphasizes the precise regulation of its synthesis at a time when fertilization and embryonic cleavage are taking place in the oviduct. Identity with a growing class of steroid-regulated oviduct secretory proteins and chitinase enzymes suggests a possible structural and/or functional relationship, which may be important in mediating these latter reproductive events.

Ovulated oocytes collected from PMSG/hCG-treated and cycling Djungarian or Siberian hamsters (Phodopus sungorus) are structurally similar with no evidence of polar body formation, indicating arrest in meiosis I.

This study was undertaken (1) to devise a method of inducing multiple follicular development and subsequent ovulation in the Djungarian or Siberian hamster (Phodopus sungorus) and (2) to assess the quality of ovulated oocytes collected from PMSG/hCG treated animals in comparison to naturally ovulating animals. Hamsters (4-5 weeks; n = 70) received 5 IU PMSG followed 50-52 hr later by 10 IU hCG. Ovulated oocytes were collected 14-20 hr after hCG injection. Ovulated oocytes were flushed from oviducts of cycling animals (7-12 weeks; n = 30) exhibiting two consecutive estrous cycles. Oocytes were fixed and subjected to triple fluorescence immunostaining using anti-tubulin antibodies, fluorescein phalloidin, and Hoechst 33258. The mean number of ovulated oocytes collected from cycling animals was 4.8 +/- 0.4 (range 1-7). Ovulation occurred in 73% of the PMSG/hCG-stimulated animals. The mean number of oocytes ovulated from stimulated animals was 9.2 +/- 0.8 (range 0-22). The ovaries of animals that did not ovulate or that ovulated few oocytes did respond to PMSG, as indicated by the presence of multiple follicular development and pre-ovulatory stigmata. There was no evidence of a polar body in ovulated oocytes collected from PMSG/hCG-treated or cycling animals, indicating that oocytes were arrested in meiosis I. In the majority (80%) of ovulated oocytes from PMSG/hCG-treated and cycling animals, cortically placed chromosomes were aligned on a metaphase plate equidistant from a bipolar spindle. Sparse f-actin staining was observed in the region of the ooplasm surrounding the chromosomes.(ABSTRACT TRUNCATED AT 250 WORDS)

An estrogen-dependent glycoprotein is synthesized and released from the oviduct in a temporal- and region-specific manner during early pregnancy in the ewe.

Administration of estradiol-17 beta (E) to ovariectomized (ovx) sheep results in the synthesis and release of an M(r) 90,000-92,000 glycoprotein into the oviductal lumen and into culture medium of ampullar explants (Biol Reprod 1992; 47:889-902). The objective of this study was to determine when and from what region of the oviduct the M(r) 90,000-92,000 glycoprotein is synthesized and released during early pregnancy. Estrous ewes were bred to intact rams of known fertility, and oviducts were obtained at estrus (Day 0) and at Days 1.5, 2, 3, 4, 6, and 16 of pregnancy. Pregnancy was verified by the presence of a fertilized egg or developing conceptus and a functional corpus luteum. Oviductal secretions were collected by flushing oviducts with saline and by explant culture. The oviductal fimbria, ampulla, and isthmus were individually cultured (24 h) in the presence of 3H-leucine (3H-leu) or 3H-glucosamine (3H-glcN). The presence of the M(r) 90,000-92,000 glycoprotein in oviductal flushings and culture medium was determined by fluorography and Western blotting. The M(r) 90,000-92,000 protein was present in SDS gels and blots of oviductal flushings from animals through Days 4-6 of pregnancy, but not in flushings from Day 16 pregnant animals or from ovx, untreated animals. This protein was present in 3H-leu- and 3H-glcN-labeled culture medium of the oviductal ampulla (Days 0, 1.5, 2, 3, 4, 6, and 16) and fimbria (Days 0, 1.5, 2, 3, and 4) during early pregnancy.(ABSTRACT TRUNCATED AT 250 WORDS)

Estrogen- and progesterone-dependent secretory changes in the uterus of the sheep.

This study was undertaken to determine the effects of 17 beta-estradiol (E) and progesterone (P) on polypeptide synthesis and release from the uterus of the sheep. Uterine flushings (UF) and endometrium were obtained from ovariectomized untreated animals, ovariectomized animals treated with E (approximately 5-10 pg/ml) for 6 days (6E) and ovariectomized animals primed with E for 6 days then treated with P (approximately 1.5-3 ng/ml), in the continued presence of E, for an additional 6 days (6EP). Endometrium was cultured (24 h) in the presence of 3H-leucine (3H-leu) or 3H-glucosamine (3H-glcN), and newly synthesized and released proteins were detected in culture media by fluorography of 10% SDS gels. The quantity of proteins in UF and radiolabeled proteins in explant culture media did not change between treatment groups (p < 0.05). Qualitative changes in the synthesis and release of proteins were observed depending on the steroid treatment. An M(r) 57,000 protein was present in UF and 3H-leu-labeled culture media obtained from animals treated only with E and an M(r) > 200,000 was present in 3H-leu-labeled culture media of endometrium obtained from 6E and 6EP animals. An M(r) 44,000 protein was present only in UF from 6EP animals but could not be detected in endometrial culture media from animals undergoing this steroid treatment. These data show that the endometrium of the ovariectomized sheep undergoes alterations in secretory protein patterns which depend on the presence of E and P.

Biosynthesis and immunocytochemical localization of an estrogen-dependent glycoprotein and associated morphological alterations in the sheep ampulla oviduct.

Published reports have shown that an M(r) 90,000-92,000 protein is released into the oviductal lumen of the sheep, during estrus at a time corresponding to ovulation and fertilization, where it associates with the embryo. The objectives of this study were (a) to determine whether estradiol-17 beta (E) alone or in combination with progesterone (P) induces the synthesis of the M(r) 90,000-92,000 protein from the ampulla and/or isthmus oviduct; (b) to monitor structural alterations in oviductal epithelial cells associated with the synthesis of this protein; and (c) to generate a polyclonal antiserum to the protein and use the antiserum to verify its cellular location and tissue specificity. Oviductal flushings and explant culture media were obtained from ovariectomized animals treated with E alone or with E plus P. The M(r) 90,000-92,000 protein was present in 3H-leucine- and 3H-glucosamine-labeled culture media of the ampulla (not isthmus) oviduct in animals treated with E alone or with E plus P. The glycoprotein was detected in gels of oviductal flushings obtained from animals treated only with E. A specific polyclonal antiserum to the protein was made and cross-reacted on Western blots of oviductal flushings from E-treated animals and ampulla (not isthmus) oviduct culture media from animals treated with E alone or with E plus P. The secretory apparatus of the epithelial cells of the ampulla oviduct matured and differentiated in response to E. Light and electron microscopic immunocytochemistry localized the M(r) 90,000-92,000 glycoprotein to secretory granules in the nonciliated cells of the ampulla oviduct. Immunoperoxidase reaction product was absent in tissue sections and Western blots of other reproductive and nonreproductive tract tissues obtained from steroid-treated animals. Therefore, the secretory cells of the ampulla oviduct of the sheep synthesize and release an E-induced, oviduct-derived M(r) 90,000-92,000 glycoprotein.

The effect of estrogen and progesterone on structural changes in the uterine glandular epithelium of the ovariectomized sheep.

The development of epithelial cells of the uterine glands of ovariectomized sheep in response to estradiol-17 beta (E) and progesterone (P) was studied using light and electron microscopy. Animals that had been ovariectomized for six weeks were placed in one of three experimental treatment groups. Group I animals (untreated controls) received no steroid treatment. Group II animals (E alone) received one 4-cm E implant (E approximately 5-10 pg/ml) and their uteri were removed after 2, 4, or 6 days. Group III animals (E-primed, P-treated) received an E implant (E approximately 5-10 pg/ml) for 6 days and then were treated with six 13-cm P implants (P approximately 1.5-3 ng/ml), in the continued presence of E, for 2, 4 or 6 days. Six weeks after ovariectomy the epithelial cells of the uterine glands were low cuboidal and morphologically appeared to be synthetically inactive. Following 2 days of E treatment the epithelial cells had significantly increased in cell height, and protein-synthesizing organelles were well developed. Maturation of the secretory apparatus continued throughout E treatment. The Golgi complex and rough endoplasmic reticulum (RER) were abundant. Lysosomal-like granules and granules of varying electron density were present in the cytoplasm. The chronic administration of P to E-primed animals did not result in any further increase in cell height. Elongated mitochondria, a cup-shaped Golgi apparatus, extensive apical microvilli, and irregularly shaped membranous profiles in the supranuclear cytoplasm characterized these uterine epithelial cells. Lysosomal-like granules, small vesicles, and scattered patches of glycogen were seen in the cytoplasm. These data show that the uterine epithelial cells of the ovariectomized sheep undergo morphological alterations in protein-synthesizing organelles and apical specializations that depend on the presence of E and P.

Effects of mentoring on job satisfaction, leadership behaviors, and job retention of new graduate nurses.

Findings from a study on the effects of using mentors to help new graduate nurses adjust to professional nursing revealed improved job satisfaction and increased leadership behaviors. The use of mentors over longer periods to help new nurses make the transition from school to nursing practice is a successful orientation strategy receiving increased attention by nursing staff educators.

Structural relationship, biosynthesis, and immunocytochemical localization of uteroferrin-associated basic glycoproteins.

Uteroferrin, a progesterone-induced secretory protein of the pig uterus, can noncovalently associate with additional progesterone-induced glycoproteins (uteroferrin-associated glycoproteins or UfAP) to form a heterodimer. The UfAP were dissociated from uteroferrin by passage through an immunoaffinity column. The flow through material consisted of two immunologically related variants of different size (Mr = 47,000-50,000 and Mr = 39,000-40,000) forms. By using an antiserum to all molecular weight components of the UfAP, it was shown that these glycoproteins were localized in the glandular epithelium of the uterus. Amino acid sequence analysis of the higher molecular weight (Mr = 47,000-50,000) form indicated it had a common amino-terminal sequence which was distinct from that of the lower molecular weight (Mr = 39,000-40,000) form. Endoglycosidase F treatment converted the Mr = 47,000-50,000 form to a common product with Mr = 43,000. Tryptic peptide analysis showed that the Mr = 39,000-40,000 form was closely related in primary sequence to the larger species. When endometrial RNA was translated in vitro, a single major product (Mr = 45,000) was immunoprecipitated by using the UfAP antiserum. These results suggest that the different forms of the UfAP originate from a single precursor by differential glycosylation and peptide cleavage. Endometrial explant cultures released all forms of the glycoproteins. When [32P]orthophosphate was provided, label was incorporated into the 6-position of D-mannosyl residues on the oligosaccharide chains of the UfAP. Therefore the associated glycoproteins have a structural feature normally associated with lysosomal enzymes.

Estrogen-dependent synthesis and release of a protein (CUPED) by cultured uterine explants from the domestic cat.

Media from cultured cat endometrial explants were analyzed for the presence of a previously characterized high molecular weight estrogen-dependent secretory protein (CUPED) by polyacrylamide gel electrophoresis and radioimmunoassay (RIA). Both L-[(3)H]-leucine and D-[(3)H]-glucosamine were incorporated into newly synthesized CUPED during the culture of endometrial explants obtained from estradiol-treated ovariectomized cats, but not during the culture of tissue obtained from untreated ovariectomized animals or estradiol-primed ovariectomized animals treated with progesterone. The addition of tunicamycin to the culture medium inhibited the synthesis and release of the glycosylated form of CUPED from endometrial explants obtained from estradiol-treated cats. These data demonstrate that CUPED is synthesized and released in vitro from endometrial explants obtained from estradiol-treated cats as a glycoprotein possessing N-linked oligosaccharide chains.