87 results on '"Gordon J. Macdonald"'
Search Results
2. A system approach to management of catastrophic risks.
- Author
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Yuri M. Ermoliev, Tatiana Ermolieva, Gordon J. MacDonald, Vladimir I. Norkin, and Aniello Amendola
- Published
- 2000
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3. Stochastic Optimization of Insurance Portfolios for Managing Exposure to Catastrophic Risks.
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Yuri M. Ermoliev, Tatiana Ermolieva, Gordon J. MacDonald, and Vladimir I. Norkin
- Published
- 2000
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4. Breed differences in clearance of porcine FSH in hypophysectomized rats
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P.M. Sluss, Gordon J. Macdonald, T H Wise, and J. Joe Ford
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Male ,endocrine system ,medicine.medical_specialty ,Metabolic Clearance Rate ,Swine ,Biology ,Rats, Sprague-Dawley ,Endocrinology ,Species Specificity ,Food Animals ,Anterior pituitary ,Pituitary Gland, Anterior ,Internal medicine ,medicine ,Animals ,Testosterone ,Receptor ,Hypophysectomy ,Tissue Extracts ,luteinizing hormone/choriogonadotropin receptor ,Radioimmunoassay ,General Medicine ,Rats ,medicine.anatomical_structure ,Animal Science and Zoology ,Follicle Stimulating Hormone ,Luteinizing hormone ,Follicle-stimulating hormone receptor ,Orchiectomy ,hormones, hormone substitutes, and hormone antagonists ,Hormone - Abstract
Extracts of anterior pituitary (AP) glands were infused i.v. into hypophysectomized male rats followed by sequential sampling of blood for 120 min. Determination of follicle-stimulating hormone (FSH) concentrations established that FSH from Chinese Meishan males decreased in the circulation of rats more slowly than FSH in extracts of AP from crossbred occidental pigs (P < 0.003). Additionally, FSH from AP extracts of castrated males disappeared somewhat more slowly (P < 0.06) than FSH from extracts of boars. Evaluation of FSH by bioassay and radioimmunoassay yielded similar concentrations in AP from Meishan and crossbred boars. Serum testosterone concentrations increased with time through 90 min after infusion of AP, but the rate of increase of testosterone was not related to amount of luteinizing hormone (LH) that was administered indicating LH receptor saturation. Unexpectedly, the rate of increase in testosterone was more rapid with AP extracts from boars than with extracts from castrated males. Observations from the current study imply structural alterations of FSH in the AP of Meishan males relative to crossbred males allowing sustained concentrations in the circulation, and this FSH possesses similar activation of the FSH receptor. The amount of LH in the AP extracts saturated the LH receptors of the hypophysectomized male rats, but some factor in extracts of boars differed from those of castrated males.
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- 2007
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5. Global Climate and Ecosystem Change
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Gordon J. MacDonald, Luigi Sertorio, Gordon J. MacDonald, and Luigi Sertorio
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- Climatic changes--Congresses, Ecology--Congresses
- Abstract
Humankind's ever-expanding activities have caused environmental changes that reach beyond localities and regions to become global in scope. Disturbances to the atmosphere, oceans, and land produce changes in the living parts of the planet, while, at the same time, alterations in the biosphere modify the atmosphere, oceans, and land. Understanding this complex web of interactions poses unprecedented intellectual challenges. The atmospheric concentrations of natural trace gases-carbon dioxide (C0), methane (CH.), nitrous oxide (N0), and lower-atmosphere ozone 2 2 (Os)-have increased since the beginning of the industrial revolution. Industrial gases such as the chlorofluorocarbons (CFCs), which are not part of the natural global ecosystem, are increasing at much greater rates than are the naturally occurring trace gases. All these gases absorb and emit infrared radiation and thus have the potential for altering global climate. The major terrestrial biomes are also changing. Although world attention has focused on deforestation, particularly in tropical areas, the development of agriculture, the diversion of water resources, and urbanization have all modified terrestrial ecosystems in both obvious and subtle ways. The terrestrial biosphere, by taking up atmospheric carbon dioxide, acts as a primary determinant of the overall carbon balance of the global ecosystem. Although the ways in which the biosphere absorbs carbon are, as yet, poorly understood, the destruction (and regrowth) of forests certainly alter this process.
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- 2013
6. Positive Association between Expression of Follicle-Stimulating Hormone β and Activin βB-Subunit Genes in Boars1
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J. Joe Ford, Gordon J. Macdonald, Thomas Wise, and Ming D. Li
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endocrine system ,medicine.medical_specialty ,Pituitary gland ,medicine.drug_class ,Cell Biology ,General Medicine ,Biology ,Follicle-stimulating hormone ,Endocrinology ,medicine.anatomical_structure ,Reproductive Medicine ,Anterior pituitary ,Internal medicine ,Gene expression ,medicine ,biology.protein ,Gonadotropin ,Receptor ,hormones, hormone substitutes, and hormone antagonists ,ATP synthase alpha/beta subunits ,Follistatin - Abstract
This study tested our hypothesis that inhibin/activin (I/A) betaB subunit and not follistatin (FS) gene expression relates positively to plasma FSH concentrations in the anterior pituitary gland of boars. Mature crossbred boars (n = 12) were selected for divergence in plasma FSH concentrations, and their anterior pituitary glands were evaluated for expression of the FSHbeta, I/A ssB, FS, calmodulin, and GnRH receptor (GnRH-R) genes by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) and/or RNase protection assays (RPAs). Expression of I/A ssB was greater (p 0.10), GnRH-R (p > 0. 08), and calmodulin (p > 0.10) genes was similar in the two groups of boars. Additionally, expression of the FSHbeta gene was correlated positively with pituitary and plasma FSH concentrations (r = 0.69 and 0.88, respectively; p < 0.05). These results support the hypothesis that activin B is partially responsible for elevated FSH concentrations in boars. Furthermore, the expression difference of the calmodulin gene observed previously between Meishan and White Composite boars represents a breed difference unrelated to FSH.
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- 1998
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7. Epitope-Specific Focusing of the Immune Response to a Minimized Human Chorionic Gonadotropin Analog
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William R. Moyle, Michael P. Bernard, Paul H. Ehrlich, Rebecca V. Myers, and Gordon J. Macdonald
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endocrine system ,Immunogen ,Protein Conformation ,Molecular Sequence Data ,Antibody Affinity ,Biophysics ,Biology ,Chorionic Gonadotropin ,Biochemistry ,Epitope ,Human chorionic gonadotropin ,Epitopes ,Mice ,Protein structure ,Antigen ,Antibody Specificity ,Animals ,Humans ,Amino Acid Sequence ,Molecular Biology ,Peptide sequence ,Cell Biology ,Molecular biology ,Protein tertiary structure ,Protein Structure, Tertiary ,Cell biology ,Antibody Formation ,biology.protein ,Immunization ,Antibody ,Dimerization - Abstract
Minimized proteins have long been used to elicit an immune response to particular regions of a protein antigen. Most efforts to derive minimized proteins have employed synthetic peptide fragments. This approach works well for linear epitopes but poorly for conformational epitopes. Here we describe a homodimeric human chorionic gonadotropin (hCG) analog that retains the conformation of related parts of hCG and elicits high affinity specific antibodies. This novel immunogen displays the tertiary structure of selected loops of the protein but lacks structures that could elicit potentially undesirable antibodies.
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- 1998
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8. Breed Differences in Expression of Inhibin/Activin Subunits in Porcine Anterior Pituitary Glands*
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M. D. Li, J. Joe Ford, and Gordon J. Macdonald
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Male ,Follistatin ,endocrine system ,medicine.medical_specialty ,Pituitary gland ,Swine ,medicine.drug_class ,Gene Expression ,Polymerase Chain Reaction ,Ribonucleases ,Endocrinology ,Species Specificity ,Anterior pituitary ,Pituitary Gland, Anterior ,Internal medicine ,Gene expression ,Follicular phase ,medicine ,Animals ,Inhibins ,Ovarian follicle ,Glycoproteins ,biology ,RNA-Directed DNA Polymerase ,Breed ,Activins ,medicine.anatomical_structure ,Follicle Stimulating Hormone, beta Subunit ,biology.protein ,Female ,Follicle Stimulating Hormone ,Gonadotropin ,hormones, hormone substitutes, and hormone antagonists - Abstract
Chinese Meishan (MS) boars have greater plasma FSH concentrations than European White Composite boars, but this difference does not occur in females of these breeds. To understand this disparity, we studied expression of the follistatin gene and of genes for the inhibin/activinα -, βA-, and βB-subunits in porcine anterior pituitary glands using quantitative reverse transcription-PCR and ribonuclease protection techniques. We found that 1) the inhibin/activin βA- and βB-subunits and follistatin were expressed in porcine pituitary; 2) the α-subunit was not detected in the porcine pituitary, but was highly expressed in porcine follicles; and 3) the βB-subunit gene is more abundantly expressed (2-fold greater) in MS boar pituitaries than in pituitaries of White Composite boars. We conclude that this is not due to a breed difference, because the expression levels of this gene were similar in pituitaries of females of these breeds. No breed differences were detected for other genes screened in this study. From these observations, we propose that activin B, a dimer ofβ B-subunits and a stimulator of FSH secretion, may be partially responsible for the elevated plasma FSH concentrations in MS boars, and intrapituitary inhibin plays no or a very minimal role.
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- 1997
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9. Apoptotic cell death in the rat adrenal gland: an in vivo and in vitro investigation
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Rocco V. Carsia, Gordon J. Macdonald, Kim I. Tilly, Jonathan L. Tilly, and Jean A. Gibney
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medicine.medical_specialty ,Histology ,Hypophysectomy ,DNA damage ,medicine.medical_treatment ,Apoptosis ,Adrenocorticotropic hormone ,Biology ,Organ culture ,Pathology and Forensic Medicine ,Rats, Sprague-Dawley ,Adrenocorticotropic Hormone ,In vivo ,Internal medicine ,medicine ,Animals ,Cells, Cultured ,Cell Biology ,Zona Reticularis ,Rats ,Endocrinology ,medicine.anatomical_structure ,Adrenal Cortex ,DNA fragmentation ,Female ,Zona reticularis ,DNA Damage - Abstract
Adrenocortical cell apoptosis was studied by using an established in vivo model, the hypophysectomized rat, and an in vitro model, viz., rat adrenal glands in short-term organ culture. In vivo, apoptosis (biochemical autoradiographic analysis of internucleosomal DNA cleavage) was weak and not apparent until 12-24 h after hypophysectomy. In situ histochemical localization of 3'-end DNA strand breaks revealed that apoptosis in vivo occurred nearly exclusively in subpopulations of zona reticularis cells. Adrenocorticotropic hormone (ACTH) maintenance completely blocked these indices of apoptosis. By contrast, apoptosis (DNA fragmentation) in cultured rat adrenal glands without ACTH was extensive and relatively rapid, being apparent after 1 h and increasing with the duration of incubation. ACTH attenuated (by 44%) but did not completely block apoptosis in vitro. Thus, ACTH appears to be the sole pituitary hormone that forestalls apoptosis of terminally differentiated adrenocortical (zona reticularis) cells. However, the discrepancy between in vitro and in vivo models in terms of the magnitude and rate of DNA fragmentation suggests that, in vivo, other factors finely regulate the magnitude of adrenocortical apoptotic cell death.
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- 1996
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10. Modulation of Cholesteryl Ester Hydrolase Messenger Ribonucleic Acid Levels, Protein Levels, and Activity in the Rat Corpus Luteum1
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Thomas R. Kolodecik, Harold R. Behrman, Gordon J. Macdonald, and Raymond F. Aten
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endocrine system ,Messenger RNA ,medicine.medical_specialty ,animal structures ,food and beverages ,Cell Biology ,General Medicine ,Luteal phase ,Biology ,APX ,Prolactin ,chemistry.chemical_compound ,medicine.anatomical_structure ,Endocrinology ,Reproductive Medicine ,chemistry ,Internal medicine ,embryonic structures ,Gene expression ,Luteolysis ,medicine ,Cholesteryl ester ,Corpus luteum - Abstract
Previous studies have shown that the induction of functional luteolysis (loss of progesterone production) with either prostaglandin F2 alpha (PGF2 alpha) treatment or hypophysectomy (APX) diminished neutral cholesteryl ester hydrolase (CEH) activity in the corpus luteum (CL) and that prolactin (PRL) replacement of APX animals prevented luteolysis and maintained CEH activity at control levels. More recent studies have shown that CEH is the same protein as hormone-sensitive lipase (HSL) and that CEH/HSL activity may be regulated by phosphorylation. However, the possibility that CEH/HSL activity may be under transcriptional and/or translation control has not been excluded. Therefore, in the present study we examined whether PGF2 alpha treatment, APX, or inhibition of PRL secretion by bromocryptine (BrC) treatment modulated CEH/HSL mRNA and/or protein levels in a coordinate fashion with CEH activity. Furthermore, we examined whether CEH/HSL mRNA and/or protein levels changed after luteinization of the ovary and after natural functional regression. PGF2 alpha treatment and APX significantly reduced CEH activity; and PGF2 alpha treatment, APX, and BrC treatment significantly reduced CEH/HSL protein and mRNA levels. PRL replacement after APX substantially blocked the reductions in CEH activity, CEH/HSL protein, and CEH/HSL mRNA levels. PRL replacement during BrC treatment significantly inhibited the reductions in CEH/HSL protein and mRNA levels. CEH/HSL mRNA levels increased twofold after luteinization. Whereas CEH/HSL mRNA levels remained elevated after natural luteal regression, CEH/HSL protein significantly decreased. In summary, the luteolytic actions of PGF2 alpha, APX, and BrC resulted in coordinate reductions in luteal CEH activity, protein levels, and mRNA levels; PRL replacement significantly reversed the luteolytic effects of APX and BrC; natural luteal regression resulted in a reduction in CEH/HSL protein without a concomitant reduction in CEH/HSL mRNA. These results suggest that ovarian CEH activity is controlled at the level of both transcription and translation, and that PRL is important for continued CEH/HSL mRNA transcription in the CL.
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- 1995
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11. Birth dates and survival after axotomy of neurochemically defined subsets of trigeminal ganglion cells
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Fletcher A. White, Robert W. Rhoades, Nicolas L. Chiaia, and Gordon J. Macdonald
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Neurofilament ,Cell Survival ,Calcitonin Gene-Related Peptide ,medicine.medical_treatment ,Population ,Immunocytochemistry ,Substance P ,Calcitonin gene-related peptide ,Biology ,Andrology ,Trigeminal ganglion ,Neurofilament Proteins ,Lectins ,medicine ,Animals ,education ,education.field_of_study ,Neuronal Plasticity ,General Neuroscience ,Neurogenesis ,Anatomy ,Immunohistochemistry ,Axons ,Rats ,Ganglion ,Phenotype ,medicine.anatomical_structure ,Animals, Newborn ,Trigeminal Ganglion ,Autoradiography ,Plant Lectins ,Axotomy ,Thymidine - Abstract
Trigeminal (V) ganglion cells with different neurochemical phenotypes or different birth dates are affected differently by neonatal axonal transection. The aim of the present study was to determine if V ganglion cell birth date and neurochemical phenotype were correlated and if these two variables could be related to responses to neonatal axonal transection. Immunocytochemistry, histochemistry, and [3H] thymidine labelling were used to determine the birth dates of V ganglion cells recognized by antibodies directed against neurofilament protein (NF), calcitonin gene-related peptide (CGRP), and substance P (SP) and those that bound the lectin Bandierea simplicifolia-I (BS-I). All V ganglion cells were born between embryonic days (E-) 9.5 and 14.5. All ganglion cells were born between E-9.5 and E-14.5. In a normalized population (percentages normalized to equal 100%), over 90% of NF-positive V ganglion cells were born between E-10.5 and E-12.5. The majority of CGRP-positive and SP-positive ganglion cells (> 90%) were generated from E-13.5 to E-14.5 and E-12.5 through E-14.5, respectively. Almost 85% of BS-I-positive ganglion cells were generated on E-12.5 through E-14.5. Previous results and additional data from this study indicated that NF- and BS-I-positive ganglion cells are proportionally more likely to be lost after neonatal axotomy and that SP-positive cells are more likely to remain. The percentage of CGRP-positive cells in the V ganglion was not significantly altered by neonatal infraorbital nerve transection. Overall, these findings do not indicate a strong relationship between cell birth date and the probability of survival after neonatal axonal damage for all V ganglion cell phenotypes. © 1995 Wiley-Liss, Inc.
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- 1995
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12. This Common Inheritance -An American View
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Gordon J. Macdonald
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Inheritance (object-oriented programming) ,Environmental Engineering ,Renewable Energy, Sustainability and the Environment ,Energy Engineering and Power Technology ,Biology ,Genealogy ,Energy (miscellaneous) - Published
- 1991
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13. The Future of Methane as an Energy Resource
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Gordon J. MacDonald
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Energy resources ,Environmental engineering ,General Earth and Planetary Sciences ,Environmental science ,Forestry ,General Environmental Science - Abstract
Analyse technico-economique des sources conventionnelles ou non (clathrates) de gaz naturel: capacite de production, reserves, localisation geographique, perspectives de production et d'utilisation dans les secteurs du transport et de la production d'electricite. Les avantages et les inconvenients de son utilisation sont discutes par rapport a la protection de l'environnement
- Published
- 1990
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14. Role of methane clathrates in past and future climates
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Gordon J. MacDonald
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Atmospheric Science ,Global and Planetary Change ,Atmospheric methane ,Clathrate hydrate ,Mineralogy ,chemistry.chemical_element ,Radiative forcing ,Permafrost ,Methane ,Carbon cycle ,chemistry.chemical_compound ,chemistry ,Carbon dioxide ,Environmental science ,Carbon - Abstract
Methane clathrates are stable at depths greater than about 200 m in permafrost regions and in ocean sediments at water depths greater than about 250 m, provided bottom waters are sufficiently cold. The thickness of the clathrate stability zone depends on surface temperature and geothermal gradient. Average stability zone thickness is about 400 m in cold regions where average surface temperatures are below freezing, 500 m in ocean sediments, and up to 1,500 m in regions of very cold surface temperature (
- Published
- 1990
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15. Development and lesion induced reorganization of the cortical representation of the rat's body surface as revealed by immunocytochemistry for serotonin
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Mark F. Jacquin, Nicolas L. Chiaia, Carol A. Bennett-Clarke, Robert W. Rhoades, John H. Haring, Gordon J. Macdonald, and Fletcher A. White
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Male ,Serotonin ,Body Surface Area ,Thalamus ,Immunocytochemistry ,Biology ,Somatosensory system ,Rats, Sprague-Dawley ,Infraorbital nerve ,Nerve Fibers ,Pregnancy ,Cortex (anatomy) ,medicine ,Animals ,Cerebral Cortex ,Neurons ,Secondary somatosensory cortex ,General Neuroscience ,Age Factors ,Somatosensory Cortex ,Anatomy ,Immunohistochemistry ,Axons ,Rats ,medicine.anatomical_structure ,Animals, Newborn ,Cerebral cortex ,Vibrissae ,Female ,Raphe nuclei - Abstract
Immunocytochemistry with an antiserum directed against serotonin (5-HT) was used to assess the development of the representation of the body surface in the rat's primary somatosensory cortex (S-I). Within 1 hour of birth (P-O), 5-HT-positive fibers were present in the marginal zone, the cortical plate, and developing layers V and VI. Immunoreactivity in the marginal zone consisted of a thin band of coarse fibers oriented parallel to the pia. Only a small number of isolated fibers were visible in the cortical plate. A denser network of both coarse and fine fibers could be seen in presumptive layers V and VI. By the first hour of P-I, 5-HT-positive axons in the deeper cortical plate were organized into a crude representation of the rat's body surface. At this age, aggregates of fibers corresponding to the head, lower jaw, trunk, and forepaw could be clearly distinguished. These regions of dense 5-HT immunoreactivity consisted primarily of fine caliber axons that had invaded the lower part of the cortical plate. Dense aggregates of fine caliber axons were also visible in developing layers V and VI. Coarse 5-HT-positive fibers were visible in all layers, but they did not appear to contribute to the pattern that corresponded to the body surface. By the first hour of P-2, the map of the body surface in S-I was more refined and a row-related organization of 5-HT-immunoreactive fibers was visible in the portion of the cortex representing the vibrissa pad. The laminar distributions of coarse and fine caliber serotoninergic axons at this age were essentially the same as on P-I. By P-2.5 (60 hours after birth), patches of 5-HT-positive fibers corresponding to individual vibrissa follicles were clearly evident. These consisted of dense aggregates of fine caliber axons that were centered in presumptive layer IV, but which also extended above and below this lamina. Over the next 3 days, the pattern continued to mature. By P-4, dense 5-HT labelling was also visible in the secondary somatosensory cortex (S-II). By the beginning of P-5, clusters of fibers corresponding to more rostral facial hairs and individual digits within the forepaw representation could also be discerned. By P-12, the differential distribution of 5-HT fibers in S-I was no longer visible. Thus, immunocytochemistry for serotonin showed a representation in S-I homeomorphic with the body surface prior to the age at which it can be discerned with other methods thought to reveal thalamocortical axons. Transection of the infraorbital nerve (ION) on the day of birth altered the organization of the vibrissal representation in the contralateral cortex from the earliest age at which it could be detected by 5-HT immunocytochemistry in normal animals. However, the departure from the normal organization was gradual. Row-related organization was clearly visible in the cortices of rats sacrificed on P-3, but not in those of rats that were killed on P-5. These results suggested that the organization of the 5-HT innervation of the cortex may be guided by thalamic afferents and further that some aspects of this guidance persist, albeit temporarily, after ION transection on P-0. The 5-HT immunoreactivity that we observed in the developing somatosensory cortex was not contained in thalamocortical axons. Unilateral electrocautery of the ventrobasal thalamus on P-4 did not reduce the density or alter the pattern of the 5-HT innervation of the cortex in rats that were examined on P-6.
- Published
- 1990
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16. Partial restoration of lutropin activity by an intersubunit disulfide bond: implications for structure/function studies
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Win Lin, Gordon J. Macdonald, William R. Moyle, and Monica Einstein
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0301 basic medicine ,endocrine system ,Stereochemistry ,General Biochemistry, Genetics and Molecular Biology ,Protein Structure, Secondary ,03 medical and health sciences ,Structure-Activity Relationship ,0302 clinical medicine ,Chlorocebus aethiops ,Animals ,Humans ,Chorionic Gonadotropin, beta Subunit, Human ,Disulfides ,Chemistry ,Cystine knot ,Structure function ,luteinizing hormone/choriogonadotropin receptor ,Disulfide bond ,Luteinizing Hormone ,030104 developmental biology ,Glycoprotein Hormones, alpha Subunit ,030220 oncology & carcinogenesis ,COS Cells ,Cystine ,Follicle Stimulating Hormone ,Follicle-stimulating hormone receptor ,Function (biology) - Abstract
Gonadal function is controlled by lutropins and follitropins, heterodimeric cystine knot proteins that have nearly identical alpha-subunits. These heterodimeric proteins are stabilized by a portion of the hormone-specific beta-subunit termed the "seatbelt" that is wrapped around alpha-subunit loop 2 (alpha 2). Here we show that replacing human chorionic gonadotropin (hCG) alpha 2 residue Lys51 with cysteine or alanine nearly abolished its lutropin activity, an observation that implies that alpha Lys51 has a key role in hormone activity. The activity of the heterodimer containing alpha K51C, but not that containing alpha K51A, was increased substantially when beta-subunit seatbelt residue beta Asp99 was converted to cysteine. As had been reported by others, heterodimers containing alpha K51C and beta D99C were crosslinked by a disulfide. The finding that an intersubunit disulfide restored some of the activity lost by replacing alpha Lys51 suggests that this residue is not crucial for receptor binding or signaling and also that hCG and related hormones may be particularly sensitive to mutations that alter interactions between their subunits. We propose the unique structures of hCG and related family members may permit some subunit movement in the heterodimer, making it difficult to deduce key residues involved in receptor contacts simply by correlating the activities of hormone analogs with their amino acid sequences.
- Published
- 2001
17. The groove between the alpha- and beta-subunits of hormones with lutropin (LH) activity appears to contact the LH receptor, and its conformation is changed during hormone binding
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William R. Moyle, Robert K. Campbell, Laurey Cosowsky, Harold Papkoff, Gordon J. Macdonald, and S.N. Venkateswara Rao
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Models, Molecular ,endocrine system ,Protein Folding ,Protein Conformation ,Recombinant Fusion Proteins ,Molecular Sequence Data ,Biology ,Biochemistry ,Chorionic Gonadotropin ,Animals ,Humans ,Amino Acid Sequence ,Receptor ,Molecular Biology ,Conserved Sequence ,DNA Primers ,Hormone response element ,Binding Sites ,Base Sequence ,luteinizing hormone/choriogonadotropin receptor ,Cell Biology ,Luteinizing Hormone ,Receptors, LH ,Thyroid hormone receptor alpha ,Hormone receptor ,Follicle Stimulating Hormone ,Luteinizing hormone ,Follicle-stimulating hormone receptor ,Epitope Mapping ,Hormone - Abstract
Gonadotropins are heterodimeric glycoprotein hormones that control vertebrate fertility through their actions on gonadal lutropin (luteinizing hormone, LH) and follitropin (follicle-stimulating hormone, FSH) receptors. The beta-subunits of these hormones control receptor binding specificity; however, the region of the beta-subunit that contacts the receptor has not been identified. By a process of elimination we show this contact to be the portions of beta-subunit loops one and three found in a hormone groove created by the juxtaposition of the alpha- and beta-subunits. Most other regions of the beta-subunit can be recognized by antibodies that bind to human chorionic hormone (hCG)-receptor complexes or replaced without disrupting hormone function. Using a series of bovine LH/hCG and human FSH/hCG beta-subunit chimeras we identified key hCG beta-subunit residues in the epitopes of two antibodies that bind to hCG-receptor complexes. These epitopes include the surfaces of beta-subunit loops one and three near residue 74 on the outside of the hormone groove and parts of the C-terminal end of the "seat belt" that holds the two subunits together. The antibody that recognized residue 74 bound to receptor complexes containing most mammalian lutropins better than to the free hormones, an indication that the outside surface of the beta-subunit groove is altered during hormone binding. This region of the beta-subunit is furthest from the alpha-subunit and is recognized equally well in the free beta-subunit and in the heterodimer. Thus, the receptor associated increase in antibody binding appears due to an interaction of this portion of the beta-subunit with the receptor and not to an effect of the receptor on the relative positions of the alpha- and beta-subunits. Unlike most previous studies designed to identify portions of the beta-subunit likely to contact the LH receptor, this indirect approach provides data that are more easily interpreted because it does not rely on the use of mutations that disrupt hormone function. The approach described here should be valuable for studying the receptor interactions of other complex ligands.
- Published
- 1995
18. Selective sparing of later-born ganglion cells after neonatal transection of the infraorbital nerve
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Patricia McCann, Robert W. Rhoades, Gordon J. Macdonald, Fletcher A. White, Howard L. Enfiejian, Carol A. Bennett-Clarke, and Nicolas L. Chiaia
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Time Factors ,Cell Survival ,medicine.medical_treatment ,Gestational Age ,Biology ,Horseradish peroxidase ,Andrology ,Infraorbital nerve ,medicine ,Animals ,Peripheral Nerves ,Horseradish Peroxidase ,Benzofurans ,Fluorescent Dyes ,Neurons ,Fetus ,General Neuroscience ,Anatomy ,Retrograde tracing ,Ganglion ,Rats ,medicine.anatomical_structure ,Animals, Newborn ,Trigeminal Ganglion ,Peripheral nervous system ,Vibrissae ,biology.protein ,Axotomy ,Sensory nerve - Abstract
A combination of [3H]thymidine labelling and retrograde tracing with either horseradish peroxidase (HRP) or true blue (TB) was used to determine whether V primary afferent neurons born on different embryonic (E) days were differentially susceptible to neonatal transection of the infraorbital nerve (ION). In one experiment, rat fetuses were exposed to [3H]thymidine on E-8.5, 9.5, 10.5, 11.5, 12.5, 13.5, 14.5, or 15.5, the left infraorbital nerve (ION) was transected on the day of birth, and both the regenerate and intact IONs were labelled with HRP when the animals reached adulthood. The percentage of HRP labelled cells that were also heavily labelled by [3H]thymidine was calculated for both the intact ganglion and that ipsilateral to the damaged nerve for each animal. A consistently higher percentage of double labelled cells on the lesioned rather than on the intact side for a given E-day was taken as an indication that cells born on the day in question had an increased probability of survival relative to the entire population of V ganglion cells that contributed axons to the ION. Cells born late in gestation on E-12.5 through 14.5 were significantly more likely than early born (E-9.5 through 11.5) cells to survive neonatal axotomy. In a second experiment, fetuses were exposed to [3H]thymidine on either E-9.5, E-10.5, or E-14.5, the vibrissa pads on both sides of the face were injected with TB within 6 hours of birth, and the ION was transected 6–8 hours later. When these rats reached at least 60 days of age, ganglia were processed for the visualization of both TB and [3H]thymidine labelled neurons. Cells labelled with both tracers would have been born on a given E-day, projected to the vibrissa pad via the ION at the time of nerve transection, and survived any naturally occurring or lesion-induced cell death. As in the HRP tracing experiment, ganglion cells born on E-14.5 were significantly more likely to survive neonatal ION transection than those born on either E-9.5 or E-10.5. © 1993 Wiley-Liss, Inc.
- Published
- 1993
19. Birthdates of trigeminal ganglion cells contributing axons to the infraorbital nerve and specific vibrissal follicles in the rat
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Nicolas L. Chiaia, Gordon J. Macdonald, Robert W. Rhoades, Howard L. Enfiejian, Michael W. Miller, Patricia McCann, and Charles M. Goddard
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Male ,Central nervous system ,Population ,Biology ,Infraorbital nerve ,Trigeminal ganglion ,Pregnancy ,medicine ,Animals ,education ,Horseradish Peroxidase ,Fluorescent Dyes ,education.field_of_study ,General Neuroscience ,Neurogenesis ,Anatomy ,Hair follicle ,Embryo, Mammalian ,Retrograde tracing ,Axons ,Ganglion ,Rats ,medicine.anatomical_structure ,Trigeminal Ganglion ,Vibrissae ,Female ,Thymidine - Abstract
Prenatal labelling with [3H]-thymidine was combined with retrograde tracing techniques in adult rats to determine the birthdates of the trigeminal (V) ganglion cells that contributed axons to the infraorbital nerve (ION) and the generation of the subsets of ION cells that innervated specific vibrissae follicles (C-1 and C-5). The V ganglion cells contributing axons to the ION are born between embryonic (E-, E-0 = the day of conception) days 9.5 and 14.5. The percentages (normalized so that they total 100%) of the total V ganglion population born on E-9.5 through E-14.5 were 5.8, 25.7, 19.8, 23.4, 21.0, and 4.4%, respectively. The distribution of birthdates for the V ganglion cells that were retrogradely labelled from the ION closely matched that for the ganglion as a whole. All of these neurons were also born on E-9.5 through E-14.5, and the percentages born on each day were 6.3, 23.6, 18.1, 24.0, 23.6, and 4.4%. Finally, a similar distribution of birthdates was obtained for the V ganglion cells that were retrogradely labelled after injection of retrograde tracers into either the C-1 or C-5 vibrissae follicles. We were unable to detect any distinctive spatial distributions for either all V ganglion or ION cells born on a specific embryonic day. Furthermore, neurons with a given birthdate and that innervated a given follicle were distributed throughout the entire region containing all of the ganglion cells supplying the follicle in question. Therefore, it appears that the V ganglion cells contributing axons to the ION are born over the entire period of ganglion neurogenesis and further that the organization of the ION's innervation of the periphery is not a function of cell birthdate.
- Published
- 1991
20. Neonatal infraorbital nerve transection in the rat: comparison of effects on substance P immunoreactive primary afferents and those recognized by the lectin Bandierea simplicifolia-I
- Author
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Robert W. Rhoades, Fletcher A. White, Gordon J. Macdonald, Carol A. Bennett-Clarke, Howard L. Enfiejian, and Nicolas L. Chiaia
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Pathology ,medicine.medical_specialty ,Cell Survival ,medicine.medical_treatment ,Immunocytochemistry ,Central nervous system ,Substance P ,Biology ,chemistry.chemical_compound ,Infraorbital nerve ,Ganglia, Spinal ,Lectins ,medicine ,Animals ,Nervous System Physiological Phenomena ,Neurons, Afferent ,Benzofurans ,Fluorescent Dyes ,Antiserum ,General Neuroscience ,Anatomy ,Retrograde tracing ,Denervation ,Immunohistochemistry ,Ganglion ,Rats ,medicine.anatomical_structure ,chemistry ,Animals, Newborn ,Trigeminal Ganglion ,Axotomy ,Plant Lectins ,Orbit ,Brain Stem - Abstract
Retrograde tracing, immunocytochemical, and histochemical methods were used to determine the manner in which different classes of trigeminal (V) ganglion cells respond to transection of their axons during infancy. Retrograde tracing with true blue (TB), histochemistry using the plant lectin Bandieraea simplicifolia-I (BS-I), and immunocytochemistry using an antiserum directed against substance P (SP) were carried out in the V ganglion and V brainstem complex of normal adult rats. In the adult V ganglion, 11.9 +/- 1.9% of the cells that sent axons into the infraorbital nerve (ION) contained SP-like immunoreactivity (SPLI) and 26.9 +/- 3.6% bound the lectin BS-I. Only 2.7 +/- 1.6% of ION cells were labelled by both the SP antiserum and BS-I. Transection of the ION on the day of birth had very different effects upon primary afferent neurons containing SPLI and those labelled by BS-I. We have previously shown that such lesions result in a significant expansion of the portion of SpC innervated by primary afferents containing SPLI and we have also provided data consistent with the proposal that ganglion cells recognized by an antiserum directed against SP are more likely than other primary afferent neurons to survive neonatal axotomy. In the present study, combination of retrograde tracing with TB and lectin binding histochemistry showed that cells recognized by BS-I were selectively lost after neonatal ION transection. Only 14.2 +/- 4.4% of the ION ganglion cells that projected into this nerve at the time of the lesion and that survived neonatal axotomy were BS-I positive when the animals reached adulthood. Neonatal ION transection also resulted in a permanent reduction in the density of BS-I binding in SpC. Bandieraea simplicifolia-I binding in the brainstem ipsilateral to the damaged nerve was almost completely gone within 1 day of the nerve transection and recovered only partially by the time the rats were 2 months of age. In alternate sections tested with the SP antiserum, there was a slight reduction in the density of SPLI in the deafferented SpC on postnatal days 4 and 5, but this change never approached that observed for BS-I binding.
- Published
- 1990
21. Overview of Global Atmospheric Change
- Author
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Gordon J. MacDonald
- Subjects
Politics ,Environmental change ,General assembly ,Political economy ,Political science ,media_common.quotation_subject ,Atmospheric change ,Atmosphere (architecture and spatial design) ,Economic stability ,Global environmental analysis ,Diplomacy ,media_common - Abstract
On November 8,1989, British Prime Minister Margaret Thatcher addressed the 44th Session of the United Nations General Assembly regarding environmental change. For the first time in the United Nations’ history, a prominent national leader discussed in detail the threats to world peace and economic stability flowing from the changes that man is imposing on the global environment. Her thesis is captured in the following quote: While the conventional political dangers—the threat of global annihilation, the fact of regional war—appear to be receding, we have all recently become aware of another insidious danger. It is as menacing in its ways as those more accustomed perils with which international diplomacy has concerned itself for centuries. It is the prospect of irretrievable damage to the atmosphere, to the oceans, to the earth itself.
- Published
- 1990
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22. Global Climate Change
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Gordon J. MacDonald
- Published
- 1990
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23. Assessing the U.S. Environment
- Author
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Gordon J. Macdonald
- Subjects
Global and Planetary Change ,Environmental Engineering ,Renewable Energy, Sustainability and the Environment ,Water Science and Technology - Published
- 1996
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24. Placental Steroid Production by the Basal and Labyrinth Zones During the Latter Third of Gestation in the Rat1
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D W Matt and Gordon J. Macdonald
- Subjects
medicine.medical_specialty ,Pregnancy ,medicine.medical_treatment ,Cell Biology ,General Medicine ,Biology ,medicine.disease ,Steroid ,Andrology ,Basal (phylogenetics) ,medicine.anatomical_structure ,Endocrinology ,Reproductive Medicine ,Placenta ,Internal medicine ,medicine ,Gestation ,Incubation ,Testosterone - Abstract
Progesterone (P) and testosterone (T) production were investigated in minced rat placental preparations on Days 16, 18, 20, and 22 of pregnancy. Whole placentae were minced or dissected into basal and labyrinth zones and minced prior to a 2-h incubation. Production of P from whole placental minces (pg X mg tissue-1 X 2 h-1) was greatest on Day 16 (P less than 0.05), dropped slightly on Day 18, and fell by nearly 50% on Days 20 and 22. Basal zone P production was greater on Days 16 and 18 (P less than 0.01) than that of the labyrinth zone, but then decreased to become equivalent to that of the labyrinth zone thereafter. Production of T from whole placental minces was greatest on Day 18 (P less than 0.05) and fell to low levels thereafter. The basal zone was almost entirely responsible for T production on all days. Incubation with the 17 alpha-hydroxylase inhibitor Su 10603 [7-chloro-3,4-dihydro-2-(3-pyridyl)-1-(2H)-napthalenone] completely blocked T production concomitant with increased P values. Placental weight increased from Days 16 to 20 because of rapid labyrinth zone growth. Estimated daily P production per placenta was not different among days, although production shifted from the basal to the labyrinth zone as term approached. Production of T per whole placenta reached maximum levels on Day 18 (P less than 0.05) and decreased thereafter. The marked (P less than 0.01) basal zone T production per placenta on Days 16 and 18 fell precipitously on Days 20 and 22.
- Published
- 1985
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25. Ovulating-Inducing Activity of FSH in the Rat1
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Michael A. Hirsch, Shao-Yao Ying, N. R. Moudgal, Harry Lipner, Gordon J. Macdonald, and Roy O. Greep
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endocrine system ,medicine.medical_specialty ,media_common.quotation_subject ,medicine.medical_treatment ,Gamma globulin ,Biology ,Effective dose (pharmacology) ,Follicle-stimulating hormone ,Endocrinology ,Induced ovulation ,Internal medicine ,medicine ,Ovulation induction ,Luteinizing hormone ,Ovulation ,hormones, hormone substitutes, and hormone antagonists ,media_common ,Hormone - Abstract
Ovine LH or FSH administered 44 hr after a priming dose of PMS induced ovulation inhypophysectomized immature rats. A well-characterized and highly specific LH antiserum (A/S) showing no cross reactivity with NIH FSH, TSH, GH or pr.olactin or with serum and tissue proteinextracts, was used to test the ability of NIH-FSH or LH-free FSH to cause ovulation. Theminimal effective dose (MEID) of LH A/S blocking ovulation induced by 10 ug LH was 3.0 ul per rat whereas that for blocking ovulation induced by FSH (100 ug) was 1.0 ul. While the MEID of the LH A/S for inhibition of ovarian weight gain was about 3 times greater than forinhibition of ovulation induced by LH, that for suppression of ovarian weight gain and inhibition of ovulation induced by FSH were the same. Incubation of FSH with variable amounts of LH A/Sfollowed by removal of the LH A/S with anti-rabbit gamma globulin resulted in preparations having no LH contamination as indicated by the double immunodiffusion test. The ovulation inducing capacity ...
- Published
- 1974
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26. Neonatal infraorbital nerve transection in rat results in peripheral trigeminal sprouting
- Author
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Eric Carlson, Nicolas L. Chiaia, Zebetta Allen, Robert W. Rhoades, and Gordon J. Macdonald
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General Neuroscience ,Rats, Inbred Strains ,Anatomy ,Biology ,Somatosensory system ,Axonal Transport ,Efferent Pathways ,Retrograde tracing ,Nerve Regeneration ,Rats ,Ganglion ,Infraorbital nerve ,chemistry.chemical_compound ,medicine.anatomical_structure ,Animals, Newborn ,chemistry ,Reference Values ,Capsaicin ,Maxillary Nerve ,medicine ,Axoplasmic transport ,Animals ,Trigeminal Nerve ,Sprouting ,Orbit (anatomy) - Abstract
Retrograde tracing techniques were employed to determine whether transection of the infraorbital (IO) nerve in either newborn or adult rats resulted in peripheral sprouting by undamaged trigeminal (V) axons. The IO nerve was sectioned just behind the vibrissa pad, either on the day of birth or when animals reached at least 60 days of age. After an additional 60 days, the same nerve was retransected in the orbit; horseradish peroxidase (HRP) or diamidino yellow (DY) was injected into the central portion of the vibrissa pad; and animals were killed 2-3 days later. In the neonatally nerve-damaged rats, this procedure invariably labelled primary afferent neurons in both the ipsilateral and contralateral V ganglia. On the ipsilateral side, these cells were located in the caudal portion of the ophthalmic-maxillary region and, less often, in the mandibular division. Their average diameter was 22.6 micron (s.d. = 5.6). On the contralateral side, most labelled ganglion cells were visible in the anteromedial part of the ophthalmic-maxillary region but a few could also be seen in the mandibular division. Their average diameter was 21.1 micron (s.d. = 5.5). No labelled ganglion cells were observed in adult rats subjected to the same series of manipulations. In a separate series of neonatally nerve-damaged animals, the above-described procedures were combined with neonatal injection of capsaicin in an effort to determine whether the observed sprouting was dependent upon the presence of large numbers of unmyelinated axons. The addition of this treatment reduced the number of labelled cells in both the ipsilateral and contralateral ganglia, but it did not alter either their distribution or average soma diameter. In a final experiment, sequential double-labelling techniques were used to determine whether the V axons that projected to the vibrissa pad via non-IO nerve branches were the result of sprouting by undamaged ganglion cells or arose from neurons that had originally projected into the IO nerve, were axotomized by our lesions, and regenerated to the vibrissa pad via another V branch. Here, the long-lived retrograde tracer true blue (TB) was injected into the vibrissa pad 6-8 hours before the neonatal nerve cut and DY was deposited into the pad after transection of the regenerate IO nerve in adulthood. Double-labelled cells in this experiment would have projected to the vibrissa pad via the IO nerve at birth and regenerated to it via another V branch in adulthood. Nearly 55% of the DY-labelled cells in this experiment also contained TB.(ABSTRACT TRUNCATED AT 400 WORDS)
- Published
- 1988
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27. Adrenal and Placental Steroid Secretion during Pregnancy in the Rat*
- Author
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Gordon J. Macdonald and Dennis W. Matt
- Subjects
medicine.medical_specialty ,Time Factors ,medicine.drug_class ,Placenta ,medicine.medical_treatment ,Diethylstilbestrol ,Ovary ,Dydrogesterone ,Biology ,Fetus ,Endocrinology ,Pregnancy ,Internal medicine ,Adrenal Glands ,medicine ,Animals ,Testosterone ,Castration ,Progesterone ,Hypophysectomy ,Adrenal cortex ,Adrenalectomy ,Rats, Inbred Strains ,Androgen ,Rats ,medicine.anatomical_structure ,Ovariectomized rat ,Pregnancy, Animal ,Female ,medicine.drug - Abstract
Studies were designed to determine the relative roles of the adrenal and ovary on androgen and progestin secretion in pregnant rats. Steroids were measured in serial plasma samples obtained from pregnant rats that had been ovariectomized, ovariectomized and adrenalectomized, or ovariectomized, adrenalectomized, and hypophysectomized and which had been treated with the steroid analogs dydrogesterone (9 beta,10 alpha-pregna-4, 6-diene-3,20-dione) and diethylstilbestrol [(E)4,4'-(1,2-diethyl-1,2- ethenediyl )bisphenol] to maintain pregnancy. Plasma levels of progesterone and 20 alpha-hydroxy-4-pregnen-3-one in pregnant rats were low on day 10, peaked on day 12 (21 +/- 3 and 8 +/- 1 ng/ml, respectively), and returned to low levels by day 16. Similar patterns of progestin levels were found in pregnant ovariectomized-adrenalectomized and ovariectomized-adrenalectomized-hypophysectomized rats maintained with steroid analogs. However, adrenalectomy caused lower levels of serum progesterone on days 10, 14, 16, and 18, demonstrating that the adrenal contributes progesterone to the pool of steroids. In a second study, plasma testosterone levels were measured from blood obtained from serially bled pregnant ovariectomized-adrenalectomized rats maintained with steroid analogs. The testosterone levels increased from day 10 (128 +/- 26 pg/ml) through day 20 (595 +/- 75 pg/ml) and fell until day 22 (411 +/- 377 pg/ml). These findings suggest that the adrenal cortex contributes to the progesterone pool during pregnancy and indicate that active in vivo feto-placental progesterone and testosterone production occurs throughout pregnancy.
- Published
- 1984
- Full Text
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28. Interactive effects of estradiol and 2,3,7,8-tetrachloro-dibenzo-p-dioxin on hepatic cytochrome P-450 and mouse uterus
- Author
-
Michael A. Gallo, Gordon J. Macdonald, Elizabeth J. Hesse, and Thomas H. Umbreit
- Subjects
endocrine system ,medicine.medical_specialty ,Polychlorinated Dibenzodioxins ,medicine.drug_class ,Uterus ,Estrogen receptor ,Weanling ,Mice, Inbred Strains ,Dioxins ,Toxicology ,Mice ,Cytochrome P-450 Enzyme System ,Estrus ,Internal medicine ,medicine ,Animals ,heterocyclic compounds ,Receptor ,Epoxide hydrolase ,reproductive and urinary physiology ,Epoxide Hydrolases ,Dose-Response Relationship, Drug ,Estradiol ,Chemistry ,Organ Size ,General Medicine ,stomatognathic diseases ,Dose–response relationship ,medicine.anatomical_structure ,Endocrinology ,Liver ,Estrogen ,Female ,Aryl Hydrocarbon Hydroxylases ,Corn oil - Abstract
Weanling C57B/6 female mice treated with 6 micrograms/kg 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) 3 times a week for one month (total dose 72 micrograms/kg) were observed to have greatly reduced relative uterine weights and histopathological changes in the uterus. Weanling CD-1 female mice were then treated with estradiol (E2) subcutaneously daily for 2 weeks. Half the mice also received 10 micrograms/kg TCDD in corn oil: acetone (9:1) by gavage 4 times during the second week. Control mice received either no E2 or no TCDD. Mice were killed on day 15 and autopsied. Relative uterine weights increased with increasing E2 doses; however, TCDD decreased this effect of E2 markedly. Liver microsomes from these animals showed that cytochrome P1-450 and P3-450 and, aryl hydrocarbon hydroxylase (AHH) induction by TCDD were independent of E2 dosage. Epoxide hydrolase was induced in TCDD treated animals. Gels showed an E2 dose dependent decrease in a protein migrating near epoxide hydrolase and 'P-450a' in animals receiving both E2 and TCDD. These results suggest that: E2 may act at the TCDD receptor; the TCDD receptor may be related to the estrogen receptor; the anti-estrogenic effects of TCDD are possibly independent of the Ah locus and AHH induction, and in TCDD-treated mice a protein migrating near epoxide hydrolase and 'P-450a' may be controlled by estrogen levels.
- Published
- 1986
- Full Text
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29. The Effects of Hypophysectomy and Administration of Pituitary Hormones on Luteal Function and Uptake of High Density Lipoproteins by Luteinized Ovaries and Adrenals of the Rat*
- Author
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Mary M. Buhr, Bruce D. Murphy, Kadaba Rajkumar, Pauline E. McKibbin, Daniel L. Grinwich, and Gordon J. Macdonald
- Subjects
medicine.medical_specialty ,Time Factors ,Hypophysectomy ,Swine ,medicine.medical_treatment ,Ovary ,Biology ,Luteal phase ,Peptide hormone ,Kidney ,Iodine Radioisotopes ,Endocrinology ,Corpus Luteum ,Internal medicine ,Adrenal Glands ,medicine ,Animals ,Pseudopregnancy ,Progesterone ,Rats, Inbred Strains ,Progesterone secretion ,Luteinizing Hormone ,Prolactin ,Rats ,Pituitary Hormones ,medicine.anatomical_structure ,Purines ,Female ,Lipoproteins, HDL ,Corpus luteum ,Lipoprotein ,Hormone - Abstract
The role of plasma lipoproteins and hypophyseal hormones in the maintenance of progesterone secretion by the rat corpus luteum was investigated. In the first experiment, rats were treated daily from days 1-6 of pregnancy with 5 mg/kg 4-aminopyrozolopyramidine (4APP), a blocker of hepatic lipoprotein secretion, or with 5 mg/kg 4APP and 1 or 2 mg ovine PRL or 0.1 ml 0.5% phosphoric acid (4APP vehicle). The administration of 4APP reduced serum cholesterol and progesterone levels on days 2-6 of pregnancy and ovarian progesterone on day 6. The reduced progesterone secretion had no effect on embryo implantation. PRL, in the doses used, was incapable of abrogating the effects of 4APP on circulating or ovarian progesterone levels. Ovaries and adrenals, but not kidneys, of pseudopregnant rats exhibited specific and saturable uptake of porcine high density lipoprotein (HDL). Time-course studies indicated that the uptake of HDL was rapid in ovaries compared to that in adrenals. Ovaries from rats not only exhibited uptake of porcine HDL, but also were capable of using it for progesterone synthesis. Immature rats were assigned to 7 groups of 16 rats each; 8 rats from each group received 4 mg/kg 4APP, and 8 received 4APP vehicle from day 1 of pseudopregnancy. Four groups underwent hypophysectomy on day 1 and received one of the following: 0.1 mg (30 IU/mg) ovine PRL, 0.1 mg ovine LH or 0.1 mg synthetic ACTH daily, or no replacement therapy. Three sham-hypophysectomized groups received 0.1 mg PRL or LH twice daily or no hormone treatment. On day 5 of pseudopregnancy, rats received intravascular HDL, as described above, and were killed 1 h later. Treatment with 4APP increased the adrenal uptake of HDL, but ovarian uptake was not different from that in the control group. Hypophysectomy reduced both adrenal and ovarian uptake of HDL. In adrenals only ACTH at the dose employed ameliorated reduction of HDL uptake induced by hypophysectomy, while in the ovaries, both PRL and LH reversed the effect of hypophysectomy. The effect of PRL on uptake was specific to [125I]HDL and did not alter [125I]albumin uptake. It is concluded that: 1) hypophysectomy reduces HDL uptake in the luteinized rat ovary; and 2) PRL and LH replacement therapy maintain ovarian uptake of HDL, suggesting a direct effect of these luteotropins on lipoprotein uptake.
- Published
- 1985
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30. Neuropeptide Y-Containing Nerves in Rat Gonads: Sex Difference and Development1
- Author
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F J Wilson, Gordon J. Macdonald, and L G Allen
- Subjects
Nervous system ,endocrine system ,Gonad ,Ovarian Cortex ,Connective tissue ,Neuropeptide ,Ovary ,Cell Biology ,General Medicine ,Anatomy ,Testicle ,Biology ,humanities ,Tunica albuginea (ovaries) ,medicine.anatomical_structure ,Reproductive Medicine ,mental disorders ,medicine - Abstract
The objectives of the present study were 1) to evaluate for a sex difference in innervation of adult rat gonads by neuropeptide Y-immunoreactive (NPY-I) nerves and 2) to examine the development of innervation of rat gonads by NPY-I nerves during the fetal and neonatal periods. With fluorescence immunocytochemistry, NPY-I nerves were profuse in adult ovarian tissues. Ovarian blood vessels were particularly well innervated by NPY-I nerves, and nerves were also detected in interstitial gland tissues. No nerves were found within the testis, and NPY-I nerves were only rarely located within the tunica albuginea. During fetal life, ovaries were devoid of NPY-I nerves; however, nerves were visualized within the connective tissue immediately peripheral to the ovary on fetal Day 22. As early as postnatal Day 2, NPY-I nerves were observed in connective tissue septa of the developing ovary. By postnatal Day 12, NPY-I nerves surrounded developing follicles and blood vessels of the ovarian cortex. In the developing testis after postnatal Day 5, NPY-I nerves were limited to the tunica albuginea and surrounding large subcapsular blood vessels. Structures within the testis lacked innervation by NPY-I nerves. These anatomical studies suggest that NPY-I nerves are absent in the gonads during fetal life and grow into the ovary and not the testis during the perinatal period and that NPY-I nerves may play a role in the functioning of the rat ovary, but may not be important in control of testicular function.
- Published
- 1989
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31. Steroid control of steroidogenesis in isolated adrenocortical cells: Molecular and species specificity
- Author
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Rocco V. Carsia, Sasha Malamed, and Gordon J. Macdonald
- Subjects
Male ,medicine.medical_specialty ,Hydrocortisone ,medicine.drug_class ,medicine.medical_treatment ,Clinical Biochemistry ,In Vitro Techniques ,Biology ,Biochemistry ,Dexamethasone ,chemistry.chemical_compound ,Endocrinology ,Adrenocorticotropic Hormone ,Species Specificity ,Corticosterone ,Internal medicine ,medicine ,Animals ,Testosterone ,ACTH receptor ,Aldosterone ,Glucocorticoids ,Molecular Biology ,Cells, Cultured ,Progesterone ,Pharmacology ,Organic Chemistry ,Rats, Inbred Strains ,Rats ,Cortisone ,Steroid hormone ,chemistry ,Mineralocorticoid ,Pregnenolone ,Adrenal Cortex ,Cattle ,Chickens ,Cyclase activity ,hormones, hormone substitutes, and hormone antagonists ,Glucocorticoid ,medicine.drug - Abstract
The molecular and species specificity of glucocorticoid suppression of corticosteroidogenesis was investigated in isolated adrenocortical cells. Trypsin-isolated cells from male rat, domestic fowl and bovine adrenal glands were incubated with or without steroidogenic agents and with or without steroids. Glucocorticoids were measured by radioimmunoassay or fluorometric assay after 1-2 h incubation. Glucocorticoids suppressed ACTH-induced steroidogenesis of isolated rat cells with the following relative potencies: corticosterone greater than cortisol = cortisone greater than dexamethasone. The mineralocorticoid, aldosterone did not affect steroidogenesis. Suppression by glucocorticoids was acute (within 1-2 h), and varied directly with the glucocorticoid concentration. Testosterone also suppressed ACTH-induced steroidogenesis. Glucocorticoid-type steroids have equivalent suppressive potencies, thus suggesting that these steroids may induce suppression at least partly by a common mechanism. Although corticosterone caused the greatest suppression, testosterone was more potent. The steroid specificity of suppression of cyclic AMP (cAMP)-induced and ACTH-induced steroidogenesis were similar, suggesting that suppression is not solely the result of interference with ACTH receptor function or the induction of adenylate cyclase activity. Exogenous glucocorticoids also suppressed ACTH-induced steroidogenesis of cells isolated from domestic fowl and beef adrenal glands, thus suggesting that this observed suppression may be a general mechanism of adrenocortical cell autoregulation.
- Published
- 1983
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32. Rat Placental Luteotropin: Initial Secretion and Luteolytic Quality
- Author
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Gordon J. Macdonald, Cassandra L. Thayer, Dennis W. Matt, and Jacqueline C. Perez
- Subjects
medicine.medical_specialty ,Time Factors ,Hypophysectomy ,medicine.medical_treatment ,Diethylstilbestrol ,Dydrogesterone ,Biology ,Progesterone analog ,General Biochemistry, Genetics and Molecular Biology ,Corpus Luteum ,Pregnancy ,Internal medicine ,Adrenal Glands ,medicine ,Animals ,Secretion ,Pseudopregnancy ,Placental lactogen ,Progesterone ,Ovary ,Estrogen analog ,Rats, Inbred Strains ,Organ Size ,Placental Lactogen ,medicine.disease ,20-alpha-Dihydroprogesterone ,Rats ,Endocrinology ,Female ,medicine.drug - Abstract
The secretion of placental lactogen begins early in pregnancy. Previous studies indicate that rat placental lactogen (rPL) is secreted from Day 8 of pregnancy and that it is luteolytic as well as luteotrophic. This study establishes the onset of both the luteotrophic and the luteolytic effects of placental lactogen in pregnant rats subject to timed hypophysectomy. Pregnancy was preserved in all groups with the administration of dydrogesterone (9 beta, 10 alpha-pregna4,6-diene-3, 20 dione), a progesterone analog, and diethylstilbestrol, an estrogen analog. Plasma progesterone and 20 alpha-hydroxypregn-4-ene-3-one (20-OHP) were measured in serial serum samples by RIA. The data indicate that rPL is secreted as early in pregnancy as the seventh day. Rats hypophysectomized on Day 6 of pregnancy or later had ovaries that contained corpora lutea that secreted increasing quantities of progesterone during pregnancy. On Day 16 serum progesterone values were lowest in animals operated on Days 4 and 5 compared to animals operated on Days 6 or 8. The 20-OHP serum values from animals operated on Days 4 and 5 declined steadily from Day 8 to Day 16. These findings indicate progestational incompetency, which was confirmed morphologically. Thus, rPL secretion begins by Day 7 and it is both luteotrophic and luteolytic.
- Published
- 1988
- Full Text
- View/download PDF
33. Effects of TCDD-estradiol interactions in three strains of mice
- Author
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Elizabeth J. Hesse, Thomas H. Umbreit, Michael A. Gallo, and Gordon J. Macdonald
- Subjects
endocrine system ,medicine.medical_specialty ,Polychlorinated Dibenzodioxins ,medicine.drug_class ,Ratón ,Uterus ,Mice, Inbred Strains ,Dioxins ,Toxicology ,Mice ,Cytochrome P-450 Enzyme System ,Internal medicine ,medicine ,Animals ,Drug Interactions ,heterocyclic compounds ,reproductive and urinary physiology ,Estradiol ,biology ,Chemistry ,Body Weight ,Age Factors ,Cytochrome P450 ,Organ Size ,General Medicine ,stomatognathic diseases ,Endocrinology ,medicine.anatomical_structure ,Mechanism of action ,Estrogen ,In utero ,Toxicity ,Microsomes, Liver ,Microsome ,biology.protein ,Female ,Aryl Hydrocarbon Hydroxylases ,medicine.symptom - Abstract
Interactions of 2,3,7,8-tetrachlorodibenzo- p -dioxin (TCDD) and estradiol were studied in three strains of mice: CD-1 and C57B/6 (TCDD sensitive) and DBA/2 (TCDD resistant at lower doses). Immature females were injected with 0–200 ng/kg/day estradiol for 2 weeks s.c. On days 7, 9, 11, and 13, mice received 10 μg TCDD/kg by gavage. Relative uterine weight increased in mice of all three strains treated with estradiol alone. Uterine imbibition was suppressed by TCDD treatment, although this effect was antagonized in a saturable manner by coadministration of estradiol. TCDD induced aryl hydrocarbon hydroxylase (AHH) in liver microsomes of treated mice independent of estradiol dose and strain of mice (the dose of TCDD used was high enough to cause AHH induction in the resistant DBA/2 mice). Treatment of CD-1 mice, but not other strains, with TCDD and estradiol resulted in a decrease in the electrophoretic band of hepatic microsomal proteins comigrating with cytochrome P -450 a and epoxide hydrase.
- Published
- 1988
- Full Text
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34. Effect of fetal infraorbital nerve transection upon trigeminal primary afferent projections in the rat
- Author
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Mark F. Jacquin, Gordon J. Macdonald, Robert W. Rhoades, and Nicolas L. Chiaia
- Subjects
Aging ,Wheat Germ Agglutinins ,medicine.medical_treatment ,Population ,Central nervous system ,Biology ,Lesion ,Infraorbital nerve ,Fetus ,Pregnancy ,Ganglia, Spinal ,medicine ,Animals ,Neurons, Afferent ,Trigeminal Nerve ,education ,Horseradish Peroxidase ,education.field_of_study ,General Neuroscience ,Anatomy ,Axons ,Nerve Regeneration ,Rats ,Ganglion ,medicine.anatomical_structure ,Animals, Newborn ,Female ,Brainstem ,Axotomy ,medicine.symptom ,Brain Stem - Abstract
Transganglionic tracing with a combination of horseradish peroxidase (HRP) and wheat germ agglutinin–conjugated HRP (WGA-HRP) was employed to compare the trigeminal (V) innervation of the brainstem in adult rats that sustained transection of the infraorbital nerve (ION) on either the day of birth or just prior to the beginning of the 17th embryonic day (E-17). The same methods were also employed to assess the effects of such lesions upon the innervation of the brainstem by the lingual, inferior alveolar, mylohyoid, and auriculotemporal V branches. Previous experiments (Chiaia et al.: Dev. Brain Res. 36:75–88, '87) showed that application of HRPand WGA-HRP to the ION in normal adult rats (N = 3) labelled 12,553 ± 1,455 (mean ± s.d.) V ganglion cells while application of these tracers to the regenerated ION after neonatal transection (N –9) labelled 5,001 ± 1,287 ganglion cells. Application of HRP and WGA-HRP to the regenerated ION in adulthood (N = 6) after fetal transection labelled 5,476 ± 3,056 ganglion cells. Thus, the numbers of ganglion cells giving rise to the regenerated ION after fetal and neonatal transection were equivalent (P >.05). The central projections of the ION after fetal transection were qualitatively different from those observed after neonatal injury. After neonatal transection, the central terminal field of regenerated ION fibers in adulthood is almost completely restricted to layers I and II of subnucleus caudalis (SpC; Jacquin and Rhoades: Brain Res. 269:137–144, '83; Chiaia et al.: Dev. Brain Res. 36:75–88, '87). After fetal transection, regenerated ION axons terminate heavily in all portions of the V brainstem complex. After neonatal ION transection, we (Jacquin and Rhoades: J. Comp. Neurol. 235:129–143, '85) have been unable to detect central sprouting of undamaged V mandibular axons by means of transganglionic tracing with HRP and WGA-HRP. Such sprouting was evident in both V subnucleus interpolaris (SpI) and SpC after fetal ION transection. We carried out one additional experiment to determine whether ION ganglion cells that survived fetal axotomy were more resistant to axonal damage than the population of neurons that normally contribute to this nerve on theday of birth. Rats (N = 9) sustained transection of the ION on E-17 and again on the day of birth. The regenerated ION was then labelled with HRP and WGA-HRP when the animals reached adulthood. Anaverage of 1,798 ± 1,050 ganglion cells were labelled in these rats and the transganglionic labelling was restricted to layers I and II of SpC. Thus, V ganglion cells that sustain axotomy on E-17 respond to damage on the day of birth in the same manneras primary afferent neurons that have not been subjected to previous injury.
- Published
- 1989
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35. THE MANY ORIGINS OF NATURAL GAS
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Gordon J. MacDonald
- Subjects
Carbon dioxide in Earth's atmosphere ,Atmospheric methane ,Earth science ,Geochemistry ,Energy Engineering and Power Technology ,chemistry.chemical_element ,Geology ,Methane chimney ,Permafrost ,Methane ,Abiogenic petroleum origin ,chemistry.chemical_compound ,Fuel Technology ,chemistry ,Carbon dioxide ,Earth and Planetary Sciences (miscellaneous) ,Carbon - Abstract
Thermodynamic calculations for the C-O-S-H system indicate that at a fixed oxygen fugacity methane is in a stable phase relative to carbon dioxide at high pressures and low temperatures. At a constant temperature and pressure, methane is favored at low oxygen fugacities. Volcanic gases and near-surface igneous rocks exhibit high values of oxygen fugacity. However, direct measurement of the oxygen fugacity of spinels from peridotites of deep origin indicate that the oxygen fugacity of these rocks is low, corresponding to an iron - wustite buffer. The relative abundance of the carbon isotopes C12 and C13 varies widely in natural gases. Methane formed by bacterial fermentation is highly enriched in the lighter isotope, while methane from deep deposits is much less so as is the methane flowing from hydrothermal vents on the East Pacific Rise. Except In extreme cases, the carbon isotope ratio cannot be used alone to assess whether methane is biogenic or abiogenic. The carbon isotope ratio in coexisting methane and carbon dioxide can be used to estimate the temperature at which the two gases came into isotopic equilibrium. This ratio indicates a high temperature of equilibration for a number of gas deposits. The carbon and helium isotope ratios together with their geologic settings are strongly suggestive that the large quantities of methane in Lake Kivu and the gases venting along the East Pacific Rise are abiogenic. Methane associated with the Red Sea brines and various geothermal areas may also be in part abiogenic. The high abundance of carbon in the Sun, the atmosphere of the outer planets, carbonaceous chondrites and comets, suggests that carbon may be more abundant in the Earth than it is in near-surface igneous rocks. Such a high abundance could lead to a progressive outgassing of methane at depth, which then is oxidized near the surface or in the atmosphere. Methane hydrates are stable at low temperatures and high pressures. Today, methane hydrates are found in areas of permafrost and in ocean sediments. Methane hydrates in ocean sediments were first formed about 20 mya (million years ago) when the Antarctic ice sheet reached sea level. Terrestrial methane hydrates formed more recently during the glaciations beginning 1.6 mya. Methane hydrates and trapped gas are probably abundant under the Antarctic ice sheet. The formation of methane hydrates may be related to the low values of carbon dioxide in the atmosphere some 20,000 years ago.
- Published
- 1983
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36. Progesterone and testosterone production by dispersed rat placental cells
- Author
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Sasha Malamed, Gordon J. Macdonald, Jean A. Gibney, and Dennis W. Matt
- Subjects
medicine.medical_specialty ,Cell type ,medicine.drug_class ,Placenta ,Trophic hormone ,Cell ,8-Bromo Cyclic Adenosine Monophosphate ,Cell Separation ,In Vitro Techniques ,Biology ,Chorionic Gonadotropin ,Human chorionic gonadotropin ,Pregnancy ,Internal medicine ,medicine ,Animals ,Testosterone ,Progesterone ,Cytotrophoblast ,Cell Biology ,General Medicine ,Androgen ,Rats ,medicine.anatomical_structure ,Endocrinology ,Reproductive Medicine ,embryonic structures ,Female ,Percoll - Abstract
Isopycnic separation and unit gravity sedimentation were employed to identify the rat placental cell types capable of producing progesterone and testosterone. Subdivision of Day 12-dispersed placental cells in Percoll gradients revealed that fractions (less than 1.048 g/ml) containing giant cytotrophoblast cells produced greater quantities of progesterone (p less than 0.01) than did fractions (greater than 1.048 g/ml) with equal numbers of placental cells but void of giant cytotrophoblasts. Unit gravity sedimentation of Day 16-dispersed placental cells revealed that when incubated, isolated giant cytotrophoblast cells were capable of producing both progesterone and testosterone. Both of the separation studies strongly suggested that other cell types also produce steroids. However, the biosynthetic capacity of the giant cytotrophoblast cell appeared to be 1000-fold greater than that of the other cell types. Incubation of Day 12-dispersed placental cells with human chorionic gonadotropin or 3',5'-cyclic adenosine monophosphate did not further increase progesterone production as compared to untreated control incubates, suggesting rat placental steroidogenesis is not under trophic hormone control. Electron microscopic observations of giant cytotrophoblast cells revealed a complex ultrastructure suggesting a variety of physiological functions.
- Published
- 1986
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37. The impact of carbon dioxide on climate
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Gordon J. MacDonald
- Subjects
chemistry.chemical_classification ,business.industry ,Fossil fuel ,Atmospheric carbon cycle ,Air pollution ,General Physics and Astronomy ,Atmospheric sciences ,medicine.disease_cause ,Education ,Carbon cycle ,Atmosphere ,chemistry.chemical_compound ,chemistry ,Carbon dioxide ,medicine ,Environmental science ,Compounds of carbon ,sense organs ,business ,Energy source - Abstract
Statistics concerning the amount of CO2 released into the atmosphere by fossil fuel burning are presented and discussed. Despite unknown factors in the carbon cycle, changes in climate are seen as very likely to occur. (AIP)
- Published
- 1979
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38. Maintenance of Pregnancy in Ovariectomized Rats With Steriod Analogs and the Reproductive Ability of the Progeny1
- Author
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Gordon J. Macdonald
- Subjects
Estrous cycle ,Fetus ,medicine.medical_specialty ,Pregnancy ,medicine.drug_class ,Cell Biology ,General Medicine ,Dydrogesterone ,Biology ,medicine.disease ,medicine.anatomical_structure ,Endocrinology ,Reproductive Medicine ,Estrogen ,Internal medicine ,medicine ,Ovariectomized rat ,Blastocyst ,reproductive and urinary physiology ,Testosterone ,medicine.drug - Abstract
The quantity of and the temporal requirements for natural steroids and steroid analogs were studied over the course of pregnancy after ovariectomy. A series of experiments determined that progesterone (3 mg/day) maintains the free blastocyst and when subsequently combined with estradiol supports implantation, and pregnancy through Day 20. The amount of estradiol (100 ng/day) that adequately induces blastocyst implantation and supports pregnancy through Day 13 had to be continued throughout pregnancy to prevent fetal resorption. Fetal survival was benefited if the estradiol dose was doubled from Day 13 to termination. During this study a within strain difference appeared which reduced the number of blastocysts that implanted. This problem was resolved by ovariectomizing the pregnant rats on Day 4 before 1000 h rather than on Day 3. Substitution of dydrogesterone (9a, lOa-pregna-4,6-diene-3,20-dione) for progesterone on an equal weight basis and diethyistilbestrol (DES) for estradiol (2 for 1) proved adequate to maintain pregnancy to term. The pups were delivered by cesarean section and raised by surrogate mothers. As the females matured they experienced normal first estrus and subsequent estrous cycles. When bred they had litters of normal numbers. The males were fecund and sired litters of normal numbers. The cross-reactivity of dydrogesterone in estrogen, testosterone, corticosterone, progesterone and 20a-hydroxy-pregn-4-ene-3-one radioimmunoassays was nil. Thus, steroid analogs can adequately support the entire course of pregnancy after fertilization in ovariectomized rats. BIOLOGY OF REPRODUCTION 27, 261-267 (1982)
- Published
- 1982
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39. Estrogen and Progesterone Secretion in Monkeys (Macaca Fascicularis) Following Melatonin or Altschule’s Pineal Extract
- Author
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Llewellyn B. Bigelow, Mark D. Altschule, Virginia Mayo Fiske, and Gordon J. Macdonald
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endocrine system ,medicine.medical_specialty ,medicine.drug_class ,Injections, Subcutaneous ,Period (gene) ,media_common.quotation_subject ,Radioimmunoassay ,Pineal Gland ,Melatonin ,Corpus Luteum ,Internal medicine ,Animals ,Medicine ,Progesterone ,Menstrual cycle ,media_common ,Tissue Extracts ,business.industry ,Obstetrics and Gynecology ,Estrogens ,Progesterone secretion ,Menstruation ,Macaca fascicularis ,Endocrinology ,Reproductive Medicine ,Estrogen ,Female ,business ,hormones, hormone substitutes, and hormone antagonists ,medicine.drug - Abstract
Large doses (30MG) of melatonin given weekly to crab-eating monkeys throughout five menstrual cycles did not change the pattern of estrogen and progesterone secretion during the period of injection or in the two succeeding cycles. Altschule's pineal extract, unlike melatonin, had no effect on estrogen or progesterone secretion during the period of injection or in the two succeeding cycles, when it was given daily between days 7 and 17 of the menstrual cycle.
- Published
- 1975
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40. Topographic organization of peripheral trigeminal ganglionic projections in newborn rats
- Author
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Bradley G. Klein, Ann Marie Sczepanik, Robert W. Rhoades, and Gordon J. Macdonald
- Subjects
Trigeminal nerve ,Spinal trigeminal nucleus ,Anatomy ,Biology ,Rats ,Peripheral ,Ganglion ,Trigeminal ganglion ,medicine.anatomical_structure ,Animals, Newborn ,Trigeminal Ganglion ,Developmental Neuroscience ,Vibrissae ,Axoplasmic transport ,medicine ,Animals ,Fluorescent tracer ,Trigeminal Nerve ,Diamidino yellow ,Developmental Biology - Abstract
Retrograde transport of fluorescent tracers (true blue and diamidino yellow) was employed to delineate the topography of the peripheral projections of trigeminal ganglion cells in newborn (less than 12 h of age) rats. Identical injections were made in adult animals for comparison. In neonates, both inter- and intradivisional topography of ganglionic projections were adult-like. Neurons which innervated mandibular fields were located posterolaterally while cells with ophthalmic or maxillary projections were restricted to the anteromedial and central parts of the ganglion, respectively. An adult-like topographic representation of the mystacial vibrissae follicles was also evident in the neonates.
- Published
- 1986
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41. Estrogen Secretion and Its Relation to Corpus Luteum Formation in Monkeys (Macaca Fascicularis) Given Melatonin
- Author
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Gordon J. Macdonald and Virginia Mayo Fiske
- Subjects
Ovulation ,medicine.medical_specialty ,medicine.drug_class ,Injections, Subcutaneous ,media_common.quotation_subject ,Hypothalamus ,Radioimmunoassay ,Biology ,Melatonin ,Estrus ,Corpus Luteum ,Pregnancy ,Internal medicine ,medicine ,Animals ,Secretion ,Progesterone ,Menstrual cycle ,media_common ,Estrogen secretion ,Obstetrics and Gynecology ,Estrogens ,Melatonin treatment ,Menstruation ,Macaca fascicularis ,medicine.anatomical_structure ,Endocrinology ,Reproductive Medicine ,Estrogen ,Female ,Secretory Rate ,Corpus luteum ,hormones, hormone substitutes, and hormone antagonists ,medicine.drug - Abstract
Daily injection of 10 mg of melatonin from the 7th through the 17th day of the menstrual cycle in the crab-eating monkey delays the appearance of increased secretion of progesterone or prevents it altogether. In the cycles following melatonin treatment, the time in the cycle when the preovulatory estrogen rise occurs is more variable and the frequency of a second estrogen peak increases.
- Published
- 1975
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42. Factors Involved in Maintenance of Pregnancy in the Rat. The Temporal Need for Estrogen, Pituitary Prolactin and the Ovary1
- Author
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Gordon J. Macdonald
- Subjects
medicine.medical_specialty ,medicine.drug_class ,Fetal Resorption ,Diethylstilbestrol ,Ovary ,Cell Biology ,General Medicine ,Progesterone secretion ,Biology ,Prolactin ,chemistry.chemical_compound ,Endocrinology ,medicine.anatomical_structure ,Reproductive Medicine ,chemistry ,Anterior pituitary ,Estrogen ,Internal medicine ,medicine ,Estradiol benzoate ,medicine.drug - Abstract
The roles of the anterior pituitary, ovary and placenta were examined in pregnant rats. All experiments were timed from Day 1 when sperm were observed in the vaginal lavage. Animals were hypophysectomized (APX) with or without subsequent autograft (APtr) or homograft of the pituitary to the kidney capsule. Estradiol benzoate (EB), Estradiol-17j3 (E-17(3) or diethylstilbestrol (DES) in sesame oil were injected s.c. When APX was done on Days 8, 9 or 10 and EB was given in doses of 0.25 or 0.5 #g/day from the day before APX through Day 12, most sites had resorbed by Day 12. Rats receiving anterior pituitary homografts on Days 4, 5 or 6 were subsequently APX on Day 8 and given E-17(3 (0,1 �zg/day) on Days 8-12. Ten of 11 rats resorbed theirimplantationsites. Only 1 of6 rats APtr on Day 8 and givenE-1713(0.1ug/day)on Days 8-12 retainedsitesbeyond Day 12.RatsAPtr on Day 2 and given E-17p (0.1 ug/day) Days 8-12 (equivalent to Days 4-8 of normalpregnancy because of the 4 day delay of implantation inherent in the model) exhibited fetal resorption on Day 16 (equivalent to Day 12). However, if the E-17(3 treatment was extended to Day 14 or 16, live fetuses were observed on Day 20 or beyond; Diethylstilbestrol (0.2 Mg/day) can replace E-1713 (0.1 Mg/day). Ovariectomy on Days 12, 16 or 18 (equivalent to Days 8, 12 or 14), in rats APtr on Day 2 and given E-1 7(3 from Day 8-16, resulted in fetal resorption. Removal of the pituitary autograft by nephrectomy on Day 10 (equivalent to Day 6) resulted in total fetal resorption by Day 16 (equivalent to Day 12).Similarly, ratsoperated on Days 12-16 (equivalent to Days 8-12) retained viable fetuses. The results suggest that during normal rat pregnancy: 1) an estrogenic source is required for implantation and must be present through Day 10-12; 2) the ovary is required for progesterone secretion beyond Day 14 and 3) pituitary prolactin is not required beyond Day 8.
- Published
- 1978
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43. Maintenance of Progesterone Secretion By Ovine Prolactin or Pituitary Autografts in the Absence of Endogenous LH
- Author
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N. R. Moudgal, H. G. M. Raj, Roy O. Greep, and Gordon J. Macdonald
- Subjects
medicine.medical_specialty ,Pituitary gland ,Hypophysectomy ,Swine ,Injections, Subcutaneous ,medicine.medical_treatment ,Radioimmunoassay ,Biology ,Transplantation, Autologous ,General Biochemistry, Genetics and Molecular Biology ,Prolactin cell ,Estrus ,Corpus Luteum ,Pregnancy ,Internal medicine ,medicine ,Animals ,Progesterone ,Estrous cycle ,Analysis of Variance ,Immune Sera ,Progesterone secretion ,Luteinizing Hormone ,Prolactin ,Rats ,medicine.anatomical_structure ,Endocrinology ,Pituitary Gland ,Female ,Chromatography, Thin Layer ,Rabbits ,Luteinizing hormone ,Corpus luteum - Published
- 1973
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44. Influence of Exogenous Gonadotropins, Antibody Formation, and Hysterectomy on the Duration of Luteal Function in Hypophysectomized Rats1
- Author
-
Armen H. Tashjian, Gordon J. Macdonald, and Roy O. Greep
- Subjects
medicine.medical_specialty ,Hysterectomy ,business.industry ,medicine.medical_treatment ,Cell Biology ,General Medicine ,Biology ,Luteal phase ,Text mining ,Endocrinology ,Reproductive Medicine ,Duration (music) ,Internal medicine ,medicine ,business ,Antibody formation ,Function (biology) - Published
- 1970
- Full Text
- View/download PDF
45. International Institutions for Environmental Management
- Author
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Gordon J. MacDonald
- Subjects
Organizational Behavior and Human Resource Management ,Sociology and Political Science ,business.industry ,media_common.quotation_subject ,Environmental resource management ,Institutional economics ,Environmental adult education ,Environmental studies ,Environmental law ,Environmental Sustainability Index ,Political Science and International Relations ,Environmental impact assessment ,Business ,Environmental consulting ,Law ,Welfare ,media_common - Abstract
The degradation of the human environment is a worldwide problem which has increasingly led to worldwide concern. All countries, whether rich or poor, young or old, irrespective of political and economic institutions, are finding that they must understand and improve the relationships between man's activities and the total environmental system. The recognition that the planet's resources and its capacities to absorb waste are definitely limited raises important questions as to how to approach solutions in a way that not only safeguards legitimate national interests but in the long run protects and enhances those resources essential to the future welfare of all states.
- Published
- 1972
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46. Involvement of Luteinizing Hormone as a Luteotropin in the Golden Hamster
- Author
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Roy O. Greep, Gordon J. Macdonald, and H. G. M. Raj
- Subjects
endocrine system ,medicine.medical_specialty ,Hypophysectomy ,medicine.medical_treatment ,Hamster ,Luteal phase ,General Biochemistry, Genetics and Molecular Biology ,Follicle-stimulating hormone ,Corpus Luteum ,Pregnancy ,Cricetinae ,Internal medicine ,Follicular phase ,medicine ,Animals ,Fetal Death ,business.industry ,Luteinizing Hormone ,Prolactin ,Endocrinology ,Pituitary Gland ,Female ,Uterine Hemorrhage ,Follicle Stimulating Hormone ,business ,Luteinizing hormone ,Golden hamster - Abstract
SummaryHypophysectomy (PX) or anti-LH treatment resulted in vaginal bleeding followed by absortion as well as luteal and follicular degeneration in 8-day pregnant hamsters. The effects were successfully reversed by daily injections of 50 μg LH in sesame oil–beeswax (82 vs 94% in controls) or 25 μg LH plus 2 mg prolactin (78%). Partial reversal was observed with 100 μg LH (50%) or 200 μg FSH plus 2 mg prolactin (31%). Lower doses of LH with or without prolactin, were ineffective. Hypophysectomy on Day 12 caused expulsion of fetuses by Day 14 or 15 in 3 out of 9 animals. These results support a luteotropic and progestational role for LH in the pregnant hamster.
- Published
- 1974
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47. Reproductive Patterns of Three Species of Macaques
- Author
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Gordon J. Macdonald
- Subjects
Menstruation ,Reproductive Medicine ,Sexual behavior ,media_common.quotation_subject ,MEDLINE ,Obstetrics and Gynecology ,Gestational age ,Fertility ,Biology ,Reproduction ,Demography ,media_common - Published
- 1971
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48. The effects of local progesterone on stilbestrol-associated vaginal adenosis
- Author
-
Robert E. Scully, Gordon J. Macdonald, Stanley J. Robboy, and Arthur L. Herbst
- Subjects
Adult ,Cytoplasm ,medicine.medical_specialty ,Vaginal Neoplasms ,Adolescent ,Vaginal Diseases ,Vaginal adenosis ,Population ,Diethylstilbestrol ,Physiology ,Luteal phase ,Epithelium ,Pregnancy ,Biopsy ,Humans ,Medicine ,education ,Cervix ,Progesterone ,Gynecology ,Metaplasia ,Vaginal cancer ,education.field_of_study ,Staining and Labeling ,medicine.diagnostic_test ,business.industry ,Suppositories ,Obstetrics and Gynecology ,Epithelial Cells ,Radioimmunoassay ,General Medicine ,medicine.disease ,Menstruation ,Abortion, Spontaneous ,medicine.anatomical_structure ,Vagina ,Stilbestrol ,Female ,business ,Precancerous Conditions ,Glycogen ,medicine.drug - Abstract
Because stilbestrol (DES)-associated vaginal adenosis appears shortly after onset of puberty, this study was undertaken to assess the effectiveness of local treatment with progesterone as an inhibitor of ovarian estrogens, the possible etiological agents of vaginal adenosis. 5 teen-age women were studied; the mother of each had received varying amounts of DES during the patient's time in utero. The biopsy-proven adenosis cases were marked by redness, squamous pegs, and chronic inflammation before treatment with 20-mg progesterone suppositories, inserted vaginally, 2 times/day. (9 figures depict the cytological appearance of the subjects' vaginas before and after therapy.) Regression of the adenosis occurred in all 5 subjects; regression was marked clinically by gradual elimination of redness of the vaginal mucosa as well as reduction of inflammation, as observed microscopically. In 3 of the 5 patients, no evidence of vaginal adenosis was found on biopsy post-therapy. In the other 2 patients, residual adenosis was confined to the cervical area. Serum progesterone concentrations were measured throughout the study by radioimmunoassay and were found to be low in the 1st half of the cycle (.75-2.3 ng/ml), but the levels increased to high luteal-phase values by the 2nd half of the cycle (8.7-24.5 ng/ml). No alterations in menstrual patterns were seen. Local progesterone application may have great value in treatment of vaginal adenosis, particularly that associated with DES exposure in utero. Therapy with progesterone resulted in regression of disease without interfering with ovulatory patterns.
- Published
- 1974
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49. Hormonal control of endometrial glycogen metabolism in theMacaca arctoides
- Author
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Laurence M. Demers, Gordon J. Macdonald, and Roy O. Greep
- Subjects
medicine.medical_specialty ,Time Factors ,Phosphorylases ,media_common.quotation_subject ,Luteal phase ,Biology ,Endometrium ,chemistry.chemical_compound ,Glycogen phosphorylase ,Estrus ,Pregnancy ,Internal medicine ,Follicular phase ,medicine ,Animals ,Glycogen synthase ,Progesterone ,Menstrual cycle ,media_common ,Glycogen ,Haplorhini ,Metabolism ,Glycogen Synthase ,Endocrinology ,chemistry ,Anthropology ,biology.protein ,Macaca ,Female ,Anatomy ,Hormone - Abstract
Endometrial biopsies obtained throughout the menstrual cycle of the Macaca arctoides show the glycogen content paralleling the serum progesterone fluctuations which occur during the menstrual cycle. Secretory phase samples contained a three-fold higher concentration of glycogen when compared to follicular phase tissue. Changes in the activity levels of the glycogen metabolizing enzymes, glycogen phosphorylase and glycogen synthetase, during various stages of the menstrual cycle are in accord with the concept that the post-ovulatory increase in endometrial metabolism is a function of progesterone influence on this tissue. Endometrial glycogen synthetase activity remains low during the early proliferative phase of the cycle and becomes significantly elevated (two-to three-fold) during the early secretory phase of the cycle. Glycogen phosphorylase shows a similar cyclicity later in the luteal phase, reaching maximal activity between the seventeenth to nineteenth day of the cycle and remaining elevated through the twenty-sixth day of the cycle. The coincident nature of the rise in peripheral progesterone to increases in uterine glycogen metabolism suggest that progesterone may be the prime modulator of uterine endometrial metabolism during the post-ovulatory phase.
- Published
- 1973
- Full Text
- View/download PDF
50. Role of Endogenous Primate LH in Maintaining Corpus Luteum Function of the Monkey
- Author
-
Roy O. Greep, Gordon J. Macdonald, and N. R. Moudgal
- Subjects
Ovulation ,Immunodiffusion ,medicine.medical_specialty ,Pituitary gland ,Endocrinology, Diabetes and Metabolism ,media_common.quotation_subject ,Clinical Biochemistry ,Radioimmunoassay ,Antigen-Antibody Complex ,Cross Reactions ,Biology ,Chorionic Gonadotropin ,Biochemistry ,Human chorionic gonadotropin ,Endocrinology ,Corpus Luteum ,Iodine Isotopes ,Internal medicine ,medicine ,Animals ,Progesterone ,media_common ,Antiserum ,Binding Sites ,Goats ,Immune Sera ,Biochemistry (medical) ,Haplorhini ,Luteinizing Hormone ,Ouchterlony double immunodiffusion ,medicine.anatomical_structure ,Freund's adjuvant ,Macaca ,Female ,Rabbits ,Corpus luteum ,Protein Binding - Abstract
Antiserum to human chorionic gonadotropin (Ayerst) was prepared by administering it in Freund's complete adjuvant to rabbits. Contaminating non-specific antibodies were absorbed with dilute normal human serum and a kaolin-acetone extract prepared from urine of children. Cross-reactivity of this material with human LH or monkey pituitary extract was established using the Ouchterlony double diffusion and competitive binding test. Biological testing involved the capacity of this material to neutralize the ovulation inducing activity of human LH and monkey pituitary extract. It was also able to compete with these two preparations in a modified radioimmunoassay using 125I-labeled human LH. This LH specific antibody (CG A/S) was then injected (2 ml/day) on days 15 through 18 or 15 and 16 into normally cycling Macaca jascicularis. Blood samples were drawn on alternate days beginning on day 9 during the experiment and the serum assayed for progesterone. Progesterone values increased due to ovulation and ...
- Published
- 1972
- Full Text
- View/download PDF
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