bluuebunny/crossref_metadata_2025_split huggingface dataset:
Response of the vagina of the spayed guinea pig to low or high doses of estrogen
Authors: Hermreck Arlo S. , Greenwald Gilbert S. 
Published: February 2005

AbstractSpayed ginea pigs injected daily for 6 to 10 days with 10, 50, 150 μg of estradiol cyclopentylpropionate (ECP) developed a mucified vaginal epithelium, similar to that observed during pregnancy or following treatment of ovariectomized animals with 5 mg progesterone and 1 μg of ECP.The epithelium did not mucify in spayed guinea pigs given 0.01 to 1.0 μg ECP daily for 10 or more days. Vaginal cornification developed only in animals treated with 1 μg ECP but the reaction was transitory and the keratinized cells were soon replaced by a stratified squamous epithelium.Spayed and adrenalectomized guinea pigs injected daily with 150 μg ECP developed a stratified squamous epithelium rather than a mucified type. However, the vaginal epithelium was mucified in ovariectomized‐adrenalectomized guinea pigs receiving 150 μg ECP and corticoids or progesterone. This suggests that after treatment with large doses of estrogen the adrenal of the spayed guinea pig produces progestin‐like hormones. These progestins interacting with exogenous estrogen are responsible for vaginal mucification.On the other hand, spayed rats maintained on 1 or 150 μg of ECP showed continuous vaginal cornification, which indicates that there are species differences in the ability of large doses of estrogen to influence the adrenal.
Further observations on the cutaneous branches of the dorsal primary rami of the spinal nerves
Authors: Pearson Anthony A. , Sauter Ronald W. , Buckley Timothy F. 
Published: February 2005

AbstractRecent investigators suggest that dermatomes extend as consecutive bands from the dorsal median line and question the existence of dorsal axial lines. Our observations were made on serial sections of human embryos and fetuses prepared with neurofibrillar stains.Cervical nerves 1, 6, 7 and 8 failed to have cutaneous branches in most cases, the remainder usually had cutaneous branches.With a few exceptions in T 1, all thoracic dorsal rami had cutaneous branches. Usually T 1, 2 and 3 became cutaneous through medial branches, while T 9 through 12 did so through lateral branches. However T 4 through 8 constitute a transition zone where many of these nerves became cutaneous through both medial and lateral branches. Thoracic 4, 5 and 6 tended to have cutaneous distribution through medial branches, but T 7 and 8 through lateral branches.All lumbar dorsal rami having cutaneous distribution did so through lateral branches, but independent branches became progressively less frequent below L 1. Lumbar 4 lacked direct cutaneous branches in most cases and succeeding nerves in all cases. These nerves form the dorsal sacral plexus.The deficit in cutaneous distribution of lower lumbar rami was not as pronounced as in the lower cervical region. A deficit is significant in relation to dorsal axial lines.
Differentiation of mouse thymus cultured in diffusion chambers
Authors: Shelton Emma 
Published: February 2005

AbstractConsiderable evidence has been brought forward in recent years to show that thymus growing in intraperitoneally implanted diffusion chambers will partially restore immunological competence to mice thymectomized at birth (Osoba and Miller, '63); Levey, Trainen and Law, '63; Law, Trainen, Levey and Barth, '64; Law, Dunn, Trainen, and Levey, '64; Osoba, ('65). Since it was suggested that the thymus cells secrete a factor that mediates the restoration, it was of interest to examine the thymic cells that grew or survived in the diffusion chamber. Whole thymuses from new‐born mice were grown in thymectomized or intact, syngeneic or allogeneic hosts of various ages. Whole‐mount preparations were made of the thymus tissue after it had grown for from 9‐‐86 days. Thymic lymphocytes, granulocytes, macrophages and fibroblasts migrated rapidly from the explant, the latter forming a sheet that covered the entire chamber. Viable lymphocytes were present in chambers removed from the host after 86 days. The striking feature of the cultures was the differentiation of the epithelium into sheets, clusters, and cords of cells reminiscent of glandular epithelium. Whorls of cells resembling Hassall's bodies were occasionally seen. These epithelial cells were distinguished by the presence of large lipid‐filled vacuoles and neutral mucopolysaccharide in the cytoplasm. It is suggested that the epithelial cells were engaged in secretory activity.
Fine structure of adrenocortical cells in adult male rhesus monkeys
Authors: Brenner Robert M. 
Published: February 2005

AbstractAdrenals of ten mature male rhesus monkeys were studied by electron microscopy.Mitochondria had lamelliform cristae in the zona glomerulosa and tubular cristae in the zona fasciculata and zona reticularis. Agranular reticulum of tubular form was scarce in the zona glomerulosa but present in great abundance in the fasciculata and reticularis. The Golgi complex was prominent in the cells of the zona glomerulosa but poorly developed in the cells of the inner cortical zones.Zona fasciculata cells contained large, highly ordered “stacks” of granular endoplasmic reticulum which showed multiple connections with the random network of tubular agranular reticulum. In the reticularis, granular endoplasmic reticulum was present in more disordered, whorl‐like arrays.Lipid droplets in the inner cortical regions were enveloped by tubules of agranular endoplasmic reticulum. Occasional sections showed these tubules ending blindly at or near the surface of the lipid droplets. This association was strongly suggestive of a functional relationship.Dense bodies varied in size and complexity of structure throughout the cortex. They were smallest and simplest in form in the zona glomerulosa; those in the zona reticularis were the largest and most complex.
Placentation of the sea otter
Authors: Sinha Akhouri A. , Mossman H. W. 
Published: February 2005

AbstractDevelopment of the sea otter placenta is described from implantation to term. It is a typical carnivore placenta, labyrinthine, endotheliochorial, and zonary (sometimes incomplete mesometrially). The annulus has 4 to 8 lobes and is widest antimesometrially. Maternal capillaries of the labyrinth have very thick almost columnar endothelium, and thick diastase resistant, heavily PAS positive basement membranes. They are surrounded by syntrophoblast and a few cytotrophoblast cells. Instances of intratrophoblastic fetal capillaries increase with age; thus maternal and fetal blood are in greater proximity in late gestation. The hematome arises during the limb‐bud period at the center of the antimesometrial portion of the developing chorio‐allantoic placenta as small isolated pouches of vascular chorio‐allantoic membrane filled with maternal blood. Each pouch is lined by columnar cytotrophoblast which phagocytoses maternal erythrocytes, and no doubt also absorbs histiotrophic products of the endometrial glands at its base. These early pouches grow and coalesce to form larger ones. The definitive hematome consists of one large, often bilobed sac (diam. 5 to 7 cm) surrounded at the base of its stalk by several smaller sacs. Elaborate villous folds subdivide the sacs and stalk. The whole hematomic mass invaginates the allantoic vesicle, the endoderm of which thus becomes its outer covering. The hematome remains very large to term. The uterine glands of the placental base are highly active throughout gestation.
The production of congenital malformations using tissue antisera. IV. Evaluation of the mechanism of teratogenesis by varying the route and time of administration of anti‐rat‐kidney antiserum
Authors: Brent Robert L. 
Published: February 2005

AbstractSheep anti‐rat‐kidney serum and rabbit anti‐rat‐kidney serum were utilized in a number of biological studies in order to clarify some of the qualitative and quantitative effects of this antiserum. The teratogenic factor or factors present in these antisera can be characterized as follows: The antiserum is (1) ineffective when administered by the oral route; (2) the antiserum is teratogenic when administered by the intravenous, intraperitoneal, subcutaneous or intrauterine route; (3) more effective by the intravenous and intraperitoneal route than by the subcutaneous route and (4) no more effective when injected into the uterine lumen of a pregnant rat than when given intravenously; (5) uterine vascular clamping experiments and injection of the antiserum during the preimplantation period indicate that the teratogenic milieu persists for days following the administration of the antiserum; (6) the antiserum can be considered a classical teratogenic agent because it produces a different spectrum of malformations on different days of gestation and concomitant fetal mortality and growth retardation; although stage specificity is not as dramatic with the antiserum as with irradiation; (7) although the exact mechanism of teratogenesis is not understood, it was pointed out that fluorescent localization data and the experiments reported herein indicate a similarity between teratogenic antiserum and trypan blue; (8) the importance of yolk sac pathology during the period of differentiation is discussed as it pertains to normal embryology, teratogenesis and the utilization of animals in drug testing programs for the evaluation of teratogenic effects.
Circadian rhythms in blood glucose and the effect of different lighting schedules, hypophysectomy, adrenal medullectomy and starvation
Authors: Pauly John E. , Scheving Lawrence E. 
Published: February 2005

AbstractWith other environmental factors rigidly standardized, normal Sprague‐Dawley rats were maintained under the following lighting schedules: (1) LD 12:12, artificial light from 6:00 A.M. to 6:00 P.M. alternating with 12 hours of darkness; (2) DL 12:12, reversal of the first schedule; (3) DD, constant darkness; and (4) LL. constant illumination.During each lighting regimen, blood glucose levels were determined on separate subgroups of 11 to 18 animals at bi‐hourly intervals during a 24‐hour period. Significant circadian fluctuations or rhythms under all lighting conditions were found when the mean blood glucose values for each bi‐hourly group were plotted as a function of time. Rats maintained under LD 12:12 conditions showed approximately a 25% difference between the maximum and minimum values. When the phasing of the peaks and troughs of blood glucose rhythm in Sprague‐Dawley rats was compared with that of a separate colony of Wistar rats, it was noted that they were similar. Starvation of the LD rats for 66 hours did not abolish the characteristic rhythm, although a lower level of blood glucose resulted. The LD 12:12 blood glucose pattern was reversed by reversing the LD cycle 180 degrees. Under LL and DD the troughs and crests seen in the glucose curves were out of phase with those of LD and with each other; this suggested that under LL or DD the rhythm had become free‐running because of the absence of the light‐dark synchronizer.Hypophysectomy modified the phasing of the normal LD pattern but did not abolish its fluctuating nature; this suggested that the LD cycle of light no longer was an effective entraining agent. Adrenal medullectomy caused an overall 13% decrease in the 24‐hour mean but did not alter the phasing of the LD pattern. The significance of periodicity analysis in relation to bioassay is discussed.
Effect of hypophysectomy and gonadotropin treatment on follicular development and ovulation in the hamster
Authors: Moore Pamela J. , Greenwald Gilbert S. 
Published: February 2005

AbstractIn hamsters hypophysectomized on day 1 of the cycle (morning of ovulation) on days 1–28 post‐hypophysectomy 99% of follicular development is limited to small and medium sized follicles with no more than five layers of granulosal cells. Since the largest preantral follicles on day 1 of the cycle have 10–12 layers of granulosal cells, it is evident that follicles become dependent on gonadotropins at an early stage of their maturation.The daily injection of 200 μg ovine follicle stimulating hormone (FSH) on days 8–11 post‐hypophysectomy results in large antral follicles; when 10 μg ovine luteinizing hormone (LH) is then injected the animals ovulate 32 eggs. When 200 μg FSH on day 8 post‐hypophysectomy is followed by 50 μg FSH on days 9–11, injecting LH results in the ovulation of nine eggs — comparable to the ovulation rate of intact hamsters. These experiments indicate that superovulation depends on sustained high levels of FSH whereas the ovulation of a normal number of eggs requires an initially high level of FSH and then much lower maintenance levels.When replacement therapy with 200 μg FSH for four days is started on the day of hypophysectomy (day 1) or day 2, follicles fail to develop past the six‐seven granulosal layer stage. However, deferring the initial injection of FSH until day 3 results in antral follicles that are ovulated by LH (ovulation = 36 eggs). This suggests that functional corpora lutea inhibit the effects of FSH on follicular growth. Progesterone administered to hypophysectomized hamsters (days 8–11 post‐hypophysectomy) increases the percentage of medium follicles at the expense of smaller stages. Progesterone injected daily along with FSH also prevents follicular development past the six‐seven granulosal layer stage in 14 of 24 hypophysectomized animals.
Action of metabolic hormones on the fine structure of liver cells. II. Effects of hypophysectomy and chronic administration of somatotropin
Authors: Cardell Robert R. 
Published: February 2005

AbstractElectron microscopic studies of hepatocytes from sham‐operated, hypophysectomized, and hypophysectomized rats treated with somatotropin were undertaken in order to obtain morphological information on the mechanism of hormone action at the cellular level. Fed and fasted animals from each of the above groups were studied. Hepatocytes from fed rats of the three groups showed similar characteristics: periportal cells contained large dense masses of glycogen throughout the cytosome with relatively little smooth endoplasmic reticulum; mid‐lobular cells displayed small dense masses of glycogen with few associated elements of smooth endoplasmic reticulum; centrilobular hepatocytes showed dispersed glycogen and abundant smooth endoplasmic reticulum. Hepatocytes from hypophysectomized rats fasted fifteen hours showed significant alterations in structure when compared with liver cells from sham‐operated animals. Differences noted were: decrease in mid‐lobular cell size and amount of smooth endoplasmic reticulum; decrease in glycogen, number of ribosomes and polysomes per hepatocyte; disorganization of the rough endoplasmic reticulum; and swelling of mitochondria and increase in number per cytoplsmic volume. Periportal hepatocytes from fasted hypophysectomized rats treated with somatotropin for ten days contain numerous small masses of glycogen with elements of smooth endoplasmic reticulum at the periphery of the glycogen masses. Mid‐lobular and centrilobular hepatocytes contain masses of dispersed glycogen with an abundance of smooth endoplasmic reticulum associated with the glycogen particles.
Pineal canaliculi: Demonstration, twenty‐four‐hour rhythmicity and experimental modification
Authors: Quay W. B. 
Published: February 2005

AbstractParenchymal perfusions of rat pineal glands with India ink solutions reveal an extravascular and intercellular system of continuous microscopic channels containing ink perfusate. This system has two, apparently interconnecting, components: pericapillary sleeves or networks, and intralobular canaliculi 0.2–0.4 μ in diameter and enmeshing the pinealocytes individually.Perfusion of the canaliculi was reduced or inhibited by either partial dehydration or exposure to hypertonic solutions, and was blocked when the perfusate contained either CaCl2 or trypsin. Hyaluronidase was without effect. The extent to which the canaliculi could be perfused followed a 24‐hour‐rhythm with a peak (mean maximal canalicular perfusion distance = 95 μ) near the end of the daily environmental light phase, and a trough (mean maximal canalicular perfusion distance = 13 μ) during the dark phase. This rhythm resembles that in rat pineal content of 5‐hydroxytryptamine. Dark‐phase perfusion distances equivalent to those of the light‐phase were obtained when 5‐hydroxytryptamine (5 × 10−3 M) was present in the perfusate. In similar circumstances norepinephrine, heparin and melatonin were without effect.It is suggested that this system of canaliculi may be significant for transport activities between pinealocytes and capillaries and that its circadian and local patency may be regulated in part by release of 5‐hydroxytryptamine by the pinealocytes, and in part by calcium ions.
DNA replication in the epithelium of rat vagina and lower cervix following estrogen‐progesterone treatment
Authors: Krueger Wayne A. , Bo Walter J. , Garrison Benjamin M. 
Published: February 2005

AbstractThe purpose of this study was to ascertain the effects of different amounts of progesterone on estrogen‐induced DNA synthesis in the vaginal and lower cervical epithelia of the rat. Ovariectomized rats were injected subcutaneously with 1 μg of estradiol‐17β dipropionate or with estradiol and 1, 5, 10 or 15 mg of progesterone for three days; control rats received oil. Tritiated thymidine was injected one hour prior to necropsy; the tissues were processed for autoradiographic study and the percentages of labeled nuclei in the basal layer from the lower half of both the vagina and cervix were determined. In the group of rats given estradiol and 1 mg of progesterone the thymidine uptake in the vagina was significantly increased over that of rats given only estrogen. However, in the rats treated with estradiol and 5, 10 or 15 mg of progesterone, the extent of DNA replication in the basal epithelial nuclei was similar to the estrogen group. These responses were compared with those of the basal epithelium from the lower half of the cervix. None of the estrogen‐progesterone treatments increased the thymidine index in the cervical epithelium above that of estrogen alone; additionally, 5, 10 or 15 mg of progesterone given with estrogen suppressed DNA replication. These data indicate that stratified epithelia of these two portions of the reproductive tract respond differently to exogenous ovarian hormones.
Paracrystalline aggregates of microtubules in the anterior pituitary cells of the chinchilla (Chinchilla laniger)
Authors: Shiino Masataka , Rennels Edward G. 
Published: February 2005

AbstractParacrystalline aggregates of microtubules were observed by electron microscopy in some cells of the anterior pituitary glands from ten untreated chinchillas (Chinchilla laniger). Longitudinal section of the paracrystals revealed regular arrays of electron‐opaque lines parallel to the long axis of the microtubules and in transverse sections the paracrystals showed an unusual checkerboard pattern of closely packed microtubules. However, the inner wall of each subunit was hexagonal in shape.
Regional differences in the contractile apparatus of intrafusal muscle fibers
Authors: Yellin Herbert 
Published: February 2005

AbstractIn spindles of rat muscles, the particular class of intrafusal fiber that is unreactive over its entire striated length when incubated for alkali‐stable “myofibrillar” ATPase, exhibits pronounced regional differences in staining following incubation for acid‐stable ATPase. This variation along the contractile polar regions of the fiber can easily lead to misinterpretations of intrafusal fiber type, as well as the erroneous suggestion of two distinct populations of muscle spindles. Furthermore, such regional staining differences are strongly suggestive of variations in the contractile apparatus along certain intrafusal muscle fibers.
Adrenergic innervation of the mammalian choroid plexus
Authors: Edvinsson L. , Nielsen K. C. , Owman Ch. , West K. A. 
Published: February 2005

AbstractChoroid plexuses from the four cerebral ventricles of mice, rats, guinea‐pigs, rabbits, cats, cows, and monkeys were either sectioned after freeze‐drying or stretched on microscope slides for subsequent exposure to formaldehyde gas to demonstrate fluorescent adrenergic nerves. All plexuses received a substantial amount of noradrenaline‐containing axons which originated in the superior cervical sympathetic ganglia. The nerve terminals enclosed both arterial and venous vessels. Some of the terminals in the tufts of the choroid plexus ran between the base of the epithelial cells and the underlying vascular wall. Thus, there are structural possibilities for a sympathetic innervation of the plexus epithelium, the plexus blood vessels, or both.
The morphology of the kidney of the atlantic hagfish, Myxine glutinosa (L.)
Authors: Heath‐Eves Michael J. , McMillan Donald B. 
Published: February 2005

AbstractThe kidney of the Atlantic hagfish, Myxine glutinosa, consists of large, paired, segmentally arranged renal corpuscles connected to the archinephric ducts by short tubules. The blood supply to the kidneys is arterial in origin; there is no renal portal system. Each renal corpuscle is supplied by one afferent arteriole and drained by several efferent vessels which in turn supply the tubules and archinephric ducts. Irregularly spaced renal veins drain blood from the ducts into the posterior cardinal veins.The capillaries of the multilobed glomeruli are lined by thick endothelial cells which are rarely fenestrated. These are coated by the short pedicels of the podocytes of the visceral layer of Bowman's capsule. The mesangium is well developed between the endothelium and the glomerular basal lamina.The epithelial cells of all regions of the tubules and archinephric ducts are characterized by a brush border, a complex system of lateral interdigitations, and a paucity of basal infoldings. Pits, vesicles, large vacuoles, and single membrane‐limited inclusion bodies (lysosomes?) are abundant in the apical cytoplasm. It is suggested that these cells are specialized for the reabsorption of materials.
Intravascular macrophages in normal calf lung. An electron microscopic study
Authors: Rybicka Krystyna , Daly Benedict D. T. , Migliore Joseph J. , Norman John C. 
Published: February 2005

AbstractIntravascular macrophages were found commonly in sections of calf lung capillaries. These cells were large with many pseudopodia of various sizes. The cell membrane was covered with an electron‐opaque coat which remains between adjacent pseudopodial walls and results in structures suggesting “micropinocytosis vermiformis.” The cytoplasm of the macrophage was electron‐lucent and contained endoplasmic reticulum, numerous mitochondria, free ribosomes, Golgi zones, dense bodies and vesicles of many sizes. These macrophages showed phagocytic activity. During erythrophagocytosis, a dense layer initially appeared at the red blood cell periphery. This layer moved toward the center together with the erythrocyte membrane as phagocytosis progressed. Simultaneously, the electron opacity of the red blood cell decreased until the cell was completely dispersed within the macrophage. This erythrophagocytosis occurred relatively seldom. The possibility that intravascular macrophages are the pre‐cursors of alveolar macrophages is discussed.