bluuebunny/crossref_metadata_2025_split huggingface dataset:
The fine structure of regenerating adrenocortical autotransplants in the rat
Authors: Penney David P. , Patt Donald I. , Dixon Wallace C. 
Published: February 2005

AbstractThe fine structural changes accompanying the regeneration of adrenocortical transplants in the rat were studied with the electron microscope. One‐half gland autotransplants were made to the dorsal musculature of male Wistar rats, weighing approximately 120 gm. Transplants were recovered after 2, 4, 7, 14, 21 and 60 days of regeneration. During the first week of regeneration there was an increase in the granular endoplasmicreticulum at the expense of the agranular form. The internal structure of the numerous mitochondria was transformed from the normal tubular and vesicular forms of the zonae glomerulosa and fasciculata, respectively, to a lamellar type. The quantities of free ribonucleoprotein particles also were reduced. During this period the viable cortical cells are considered to be more deeply involved in protein synthesis and growth rather than hormone biosynthesis. Following 14 days of regeneration and thereafter, the characteristics of the mal intact adrenal cortex became established. Highly osmiophilic “dark cells,” present in the inner zones of the normal intact adrenal cortex, firstappeared after 14 days of regeneration, and were widely scattered throughout the cortexafter three weeks. After two months of regeneration, the “dark cells” were again concentrated in the inner cortical zones. During this latter period, hormone biosynthesis appears to be the major cell function. Possible structural‐functional relationships are discussed.
The preferential removal of bone and tooth collagen
Authors: Quigley Mervyn B. , Zwarych Phyllis D. 
Published: February 2005

AbstractThis investigation was undertaken to remove collagen from bone and tooth sections following fixation, decalcification and sectioning so that the noncollagenous tissues could be better demonstrated. Half heads of white mice were fixed in one of the following:Susa, neutral buffered formalin, ethyl or methyl alcohols. Decalcification was carried out with formic acid‐sodium citrate solution, hydrochloricformic acid mixtures, formic acid alone, or the tetrasodium salt of ethylenediamine tetra‐acetic acid. Paraffin sections were cut at 8 μ. After deparaffinization and hydrations the sections were immersed in one of two solutions, distilled water alone or 0.1% solutionof collagenase in distilled water. The experimental sections were incubated at 37°Cfor periods ranging from two to four days. Sections were then stained with picro naphthol blue black, hematoxylin and eosin, Van Gieson's stain or Masson's stain. The distilled water sections showed no change. The collagenase treated sections showed that the collagen had been removed from the matrix of bone and dentin leaving behind theosteocytes and odontoblast processes.
A report of a 7‐toed foot
Authors: Nelson Edward M. 
Published: February 2005

AbstractThe right foot of a 65‐year old female specimen from the gross anatomy laboratory had seven toes. A study by x‐ray films and dissection showed that two extra toes were inserted within the normal limits of the foot between the hallux and axial digits.The phalangeal complement of the seven toes was complete but the two extra toes were borne on the bicapitate distal end of a single extra metatarsal. The medial (first) cuneiform tarsal was tripartite.The flexor musculature was for all practical purposes complete but the extensor musculature absent.
Development of the pancreas of the rat embryo in vitro: Islets and acini
Authors: Schweisthal Michael R. , Céas Maria P. , Wells Lemen J. 
Published: February 2005

AbstractDeveloping pancreases from embryos of thirteen and one‐half to seventeen and one‐half days were placed on rayon grids and cultivated on a liquid medium of cock serum and chick embryo extract for periods of two to ten days. The cultures were incubated at 37°C in air supplemented by controlled oxygen and carbon dioxide.Pancreatic islets develop well in organ culture. This process usually involves increases in the size of islets and in the number of cells per islet, and sometimes involves an increase in the number of islets. The rate of morphogenesis of islets is variable: slower than that in normal controls during equal time in days (most cases) or equal to it (several cases) or faster than it (few cases). The development of islets includes the formation of granulated beta cells (many cases). The beta cells may reach stages as advanced as those in normal pancreases of postnatal day 3 (few cases). The existence of granulated beta cells in cultures from explants too young to have them constitutes convincing morphologic evidence of the production of insulin or pre‐insulin during the periods of culture.The development of acini in organ culture includes the formation of them from pancreatic primordia with no acini and the appearance of zymogen granules in the acinar cytoplasm. The morphogenesis may reach stages as advanced as those in normal pancreases of prenatal day nineteen and one‐half (several cases).
Observations on the adrenal glands of the mongoose
Authors: McKeever Sturgis , Tomich P. Quentin 
Published: February 2005

AbstractAdrenal glands from mongooses, classified according to sex, age and reproductive condition, were examined histologically. The capsule, cortical zones and medulla were described and differences exhibited by the various classes were noted. Percentage width of the three cortical zones was computed for the different classes. Similarity in relative weights of glands from animals classified according to age and reproductive condition, as reported in the literature, was reflected in similarity of the histological appearance of glands from animals so classified. Sexual dimorphism in relative weight of adrenals from adult animals was found to be attributable to development of a distinct inner zona fasciculata in adult females. Glands of adults of both sexes were characterized by presence of much connective tissue at the reticularismedulla border. High adrenal weight/body weight ratio in fetuses was attributable to a high degree of vascularization and to presence of many large vacuoles in the cytoplasm of fascicular cells.
Prerequisites for a photoreceptor structure in the crayfish tail ganglion
Authors: Hermann Howard , Stark Lawrence 
Published: February 2005

AbstractOn grounds of electron microscopic appearance (Hama, '60), the side of abdominal photoreceptor organ in crayfish (Orconectes virilis [Hagen]) has been questioned. Illumination of any part of ventral nerve cord (exclusive of A6 ganglion), e.g., A2, A3, A4, A5, and afferent roots of A6, shows no physiological response. A6 alone shows phototransduction process pulses. Sectioning of cord restricts locus to A6. Spurious effects from cephalic eye response were seen.Physiological investigation has restricted the crayfish‐tail photoreceptor–organ to include photosensitive elements lying only within the sixth abdominal ganglion, and two to four B‐fibers carrying nerve impulse responses through the ventral nerve cord. It is therefore possible to exclude the “Hama‐structures,” associated with the giant fiber system, and located diffusely in the nerve cord, from any role in the phototransduction process. Attention of anatomists is called to this primitive and interesting photoreceptor organ.
The chromosomes of the ovary of the human fetus
Authors: Kindred James E. 
Published: February 2005

AbstractThe chief purpose of this paper is to show that the human fetal ovary is a rich source of large actively dividing cells. The material consisted of the ovaries from five stillborn, morphologically normal human fetuses; 150 mm negro; two, 160 mm white; an 800 gram white; and a term white. The ovaries of the first three fetuses were removed within several hours after birth; those from the last two were removed at autopsy, wrapped in cellophane, placed in an insulated container and mailed to me. These were prepared for study about 36 hours after autopsy. Smears and squashes were made according to modern methods, but no colchicine was used. The nuclei of the ova were very tough and did not respond well to the usual hypotonic technics. Best results were obtained from fragments of the ovary suspended in blood, smeared, dried in the air and stained with Wright's blood stain. Qualitative studies were made of the chromosomes, their shapes during prophase and metaphase of meiosis; and quantitative studies were made by planimetry of the areas of the squashed chromosomes as they occurred in enlarged photographs. The planimeter measurements of areas of squashed haploid chromosomes showed remarkable agreement in percentages of the total chromosome area included within each of the accepted seven classes of chromosomes from nucleus to nucleus. Sample karyotypes were made from nuclei of the five fetuses, but no unequivocal absolute numbers could be counted, because of the twisted condition of the chromosomes and the difficulty in identifying the smallest ones.
The embryonic heart subjected to radar
Authors: Paff George H. , Boucek Robert J. , Nieman Richard E. , Deichmann William B. 
Published: February 2005

AbstractIt is known that microwaves can damage tissue but the cause is poorly understood, e.g., can tissue be damaged in the absence of undesirable heat levels? To answer this question 106 isolated 72 hour embryonic chick hearts were subjected to radar waves at a frequency of 24,000 megacycles, a wave length of 1.25 cm and exposures of 478, 297, 167 and 74 mw/cm2 for lengths of time varying between a few seconds and three minutes. Electrocardiograms were taken as a continuous run before, during and after radar treatment. The hearts were planted in blood plasma on the surface of saran sheet and microwaves were directed through the sheet at the heart. Where necessary a stream of cold air was used to offset undesirable elevation of heat. At exposures of 478 and 297 mw/cm2 damage was swift and devastating. No conclusion seemed justified. However, at an exposure of 167 mw/cm2 it was possible to prevent elevation of temperatures above 38°C. Significantly the hearts showed damage in the ECG, i.e., shortening of the QT interval, increased height and breadth of the T wave and the appearance of a large U wave. Finally at 74 mw/cm2 it was possible to control heat merely by maintaining an ambient temperature below 25°C. Of twenty‐five hearts so exposed, all showed ECG changes mentioned in the previous paragraph. The conclusion seems justified, that radar waves can damage tissue at exposures which do not raise the temperature to a harmful level.
Investigations on the lateral nasal gland of the rat
Authors: Warshawsky Hershey 
Published: February 2005

AbstractA gland lying in the lateral wall of the nasal cavity of the rat has been described and identified as the “lateral nasal gland.” The gland cups the outer aspect of the alveolar bone of the upper incisor root, and lies between it anteriorly, and the alveolar bone of the root of the first molar posteriorly. It is bounded by the hard palate ventrally, the infraorbital fissure laterally and the nasal mucosa, medially and dorsally. The gland consists of serous acini, the secretion granules of which are rich in PA‐Schiff positive material. These acini are clearly distinguished from the mucous‐secreting nasal mucosal glands which lie in the mucosa and border the acini of the lateral nasal gland. The acini of the lateral nasal gland are drained by intercalated ducts into striated ducts which anastomose to form the principal excretory duct. The latter pursues a long tortuous course beneath the mucosa of the lateral nasal wall to open into the nasal vestibule near the external nares.
Derivatives of cortical cords in adult freemartin gonads of bovine quintuplets
Authors: Rajakoski E. , Hafez E. S. E. 
Published: February 2005

AbstractThe anatomy of reproductive organs including histology and cytology of the gonads of one‐year‐old bovine quintuplets were investigated. The experimental animals were four freemartins and one fertile bull with normal sexual libido. In all four freemartins the cervix was absent but the vestibule and the uterine horns were present. The highest degree of transformation of an ovary toward the male pattern was characterized by absence of germinal epithelium, secondary tunica albuginea, ovarian cortex, and follicles; and by presence of mesothelium, primary tunica, tunica vasculosa, interstitial cells, primary sex cords, centrally located rete, epididymis and ductus deferens.Least transformation was characterized by partial presence of ovarian cortex with germinal epithelium, secondary tunica and primordial, growing and Graafian follicles with oocytes and nuclei in prophase of heterotypic division and more peripherally located rete. Histological transformation of gonads was parallel to anatomical transformation of reproductive organs. One male embryo was able to masculinize four of the female quintuplets at a lesser degree than that generally reported in the literature for twins and triplets. The histological differences of the right and left gonad of the same freemartin may be due to differences in the stage of embryonic development or, the sensitivity of the gonadal tissues at the time threshold amounts of circulating substances of male origin were available. The presence of oocytes in the luteal structures may indicate that the lutein cells of such structures originate from luteinized unruptured follicles rather than from the interstitial cells.
The vascularization of adrenal transplants in the rat and the effect of X‐irradiation
Authors: Wyman Leland C. , Macchi I. A. , Patt Donald I. , Shaw Brenda 
Published: February 2005

AbstractVascularization of subcutaneous (ear) and mesenteric adrenal autografts, homografts, and x‐irradiated autografts was studied microscopically through visualization of small blood vessels by intravascular precipitation of lead chromate. Vascularization of autografts in both sites begins on the third day after transplantation with a surface network of small vessels. Vascular buds penetrate the graft on the fourth day. On the seventh vascularization is complete. Vessels penetrate along regenerated adrenocortical fasciculi. Later, large vessels supplying the network around the graft are prominent and venous sinuses exist near the surface. Vascularization of subcutaneous homotransplants follows the same qualitative course but is chronologically irregular, delayed one or more days in most cases. On the second day an inflammatory vascular reaction occurs around the wound in the ear. Generally, vessels are finer, less well injected than in autografts. Mesenteric homografts, however, are vascularized like mesenteric autografts. X‐irradiation of adrenals in vitro with 2,000 r prior to autografting also produces chronological irregularity and retardation of vascularization, up to 28 days after subcutaneous transplantation, but only during the first 12 days in mesenteric transplants. Except for reduction in size, from the thirteenth day on, x‐irradiated mesenteric transplants are like non‐irradiated controls.
Electron microscopic studies on the red pulp of the rabbit spleen
Authors: Roberts Daniel K. , Latta John S. 
Published: February 2005

AbstractElectron microscopic studies reveal that the red pulp of the rabbit spleen is composed of reticular cells, reticulum and elements of the blood circulating through it. The three types of reticular cells described follow no definite pattern as to types of spaces they line and are not always adjacent to a basement membrane. Similar or dissimilar cells may line a basement membrane on the same or opposing sides. The entire red pulp area is intercommunicating through pores and junctions of the several spaces and in that area in which no basement membrane exists, the cytoplasmic projections of the reticular cells form a meshwork of spaces. Terminal arterioles are seen to end in collapsed type channels with a change from endothelium to Type I reticular cells. These rapidly join dilated areas. The reticular network of the spleen appears as four types: homogeneous, fibrillar, a combination of these, and reticular cells only. Isolated cilia are found in the reticular cell cytoplasm and are shown to be associated with a basal body and a centriole. The investigation supported the hypothesis that the red pulp of the spleen in the adult rabbit is a functionally dynamic area constantly changing its histological structure, both regarding cells and state of the vascular channels.
Multiple anomalies in a human fetus associated with absence of one umbilical artery
Authors: Bridges J. B. , Morton W. R. M. 
Published: February 2005

AbstractA malformed human fetus with multiple congenital anomalies including absence of an umbilical artery is described. These anomalies include malpositioning of the apex of the heart; a “mirror image” position of the liver; mal‐rotation of the gut with absence of external demarcation into small and large intestine; failure of development of the cloacal region with imperforate anus and absence of a urethra; undescended testes and bilaterally mal‐placed scrotal sacs, but the presence of a median phallus in spite of the failure of the ventral abdominal wall to develop fully.Factors known to influence the production of fetal anomalies in man and animals are discussed and a brief review of the literature on single umbilical arteries, which are known to be associated frequently with congenital anomalies, is given.
The human fetal thyroid I. Its weight in relation to body weight, crown‐rump length, foot length and estimated gestation age
Authors: Shepard Thomas H. , Andersen Henning J. , Andersen Helge 
Published: February 2005

AbstractThe weights of 75 human fetal thyroids were analyzed in relation to crown‐rump length, foot length, weight, and estimated gestation age. The ratio of thyroid weight to body weight was lower in the smaller fetuses and gradually increased until the fetus was 70–90 mm in crown‐rump length when the ratio attained a value close to that found in the newborn and adult. This period of development when the relative weight of the thyroid becomes constant coincides with the time of appearance of colloid and the onset of ability to concentrate iodine.A comparison of estimated age of fetuses in the Danish material and the formalin‐fixed fetuses from the Carnegie Collection shows the Danish fetuses under 40 mm in crown‐rump length to be four to six days older than the average given by Streeter. Streeter may have made his average too low and probably the relative ages of the two groups are comparable.
Transuterine migration and spacing of bovine embryos during gonadotropin‐induced multiple pregnancy
Authors: Hafez E. S. E. 
Published: February 2005

AbstractUnilaterally ovariectomized and intact cattle were injected with 1,500 i.u. gonadotropins to induce superovulation, inseminated at estrus and autopsied 30 to 60 days post ovulation. The allantochorion was dissected in situ and the viability and position of embryos in utero measured. There was no difference between the intact and unilaterally ovariectomized animals in the number of corpora lutea. One to ten embryos were recovered per cow; intact animals had more embryos than the ovariectomized ones. One to two embryos migrated per uterine horn; the percentage of transuterine migration was lower in the intact animals than in the ovariectomized ones. In unilaterally ovariectomized and intact animals, a single uterine horn could sustain only one or two embryos. When the uterine horn contained one embryo, the embryo occupied the middle or upper two‐thirds of the horn. With the increase of the number of embryos the sites of embryos were unevenly spaced and overcrowded. This phenomenon led to a high rate of fetal mortality especially when the uterine horn contained more than two fetuses and transuterine migration failed to occur. The results are discussed in relation to endocrine mechanisms and species differences as they affect uterine contractions.
The effect of endocrine gland extirpations on the size of nucleoli in rat hypothalamic neurons
Authors: Ifft John D. 
Published: February 2005

AbstractWith the object of investigating the so‐called “feed‐back” mechanism whereby hormones from the various endocrine glands presumably influence the hypothalamus in its regulation of the hypophyseal tropic hormones, the effect of hypophysectomy, ovariectomy, thyroidectomy, adrenalectomy and adrenal medullectomy on the nucleolar size of neurons in 16 hypothalamic nuclei was studied. A total of forty‐five female albino rats was used. The nucleoli were measured under oil by means of a Cooke AEI image splitting eyepiece. For every rat 50 nucleoli in each of the 16 hypothalamic nuclei was measured, a total of 36,000 measurements. Hypophysectomy was found to affect all of the nuclei either after a short period (5 days) or after 60 days. Ovariectomy (20 days) caused nucleolar size changes in six nuclei, thyroidectomy (30 days) in eight, adrenalectomy (14 days) in all of the nuclei and adrenal medullectomy (30 days) in all of the nuclei. The results indicate that the absence of the various hormones does affect the activity of hypothalamic neurons as determined by nucleolar size changes. The use of the present methods also appears to “localize” centers for specific activities in the hypothalamus in some instances (e.g. ovariectomy) but not in others (e.g. adrenalectomy).
The gross morphology of the arterial supply to the trachea, primary bronchi, and esophagus of the rabbit
Authors: Blanding James D. , Ogilvie Robert W. , Hoffman Carolyn L. , Knisely William H. 
Published: February 2005

AbstractThe gross arterial blood supply to the trachea, primary bronchi, and esophagus of six normal domestic rabbits has been studied by the use of injection techniques followed by careful in situ dissections. Several patterns are described with more variation being apparent on the left side.
Saimiri sciureus as an experimental animal
Authors: Beischer D. E. , Furry D. E. 
Published: February 2005

AbstractRecent Primate research projejcts utilizing the squirrel monkey (Saimiri sciureus) established the need for basic biological data concerning this animal. Included in this present report are discussions of laboratory maintenance, dietary requirements, and antihelminthic thearpy. Original data on birth weight (90–100 gm) and the gestation period (167 ± 2 days) are recorded. The weight distribution of a colony of adult animals maintained in captivity for a period of three years is included. Fresh organ weights from ten animals obtained at necropsy were recorded for brain, pituitary, heart, lungs, spleen, liver, pancreas, kidney, adrenals, and gonads. Body weight, body length, and the length of the esophagus, stomach, duodenum, small intestine, cecum, and colon were recorded. Determination of hematologic values included erythrocyte and leukocyte counts, hemoglobin and hematocrit determination and differential count of white blood cells. Various blood chemistry values are included. Data on heart rate, respiratory rate and body temperature of animals restrained for a 24 hour period are tabulated. Environmental stress and neuroanatomical studies using the squirrel monkey are reviewed.