bluuebunny/crossref_metadata_2025_split huggingface dataset:
Complex patterns of expression suggest extensive roles for the α2β1 integrin in murine development
Authors: Wu Justina E. , Santoro Samuel A. 
Published: February 2005

AbstractThe extracellular matrix plays important roles in embryogenesis. The integrin family of adhesion receptors may mediate critical cellular interactions with the extracellular matrix during development. In this study, we elucidated the developmental spatial and temporal expression pattern of the α2β1 integrin heterodimer, a cell surface receptor for collagens and laminin. We generated reagents for studying the α2β1 integrin and examined the developmental expression of the integrin in postimplantation mice. A partial length murine α2 cDNA was isolated and the protein encoding region was found to be 82% homologous to that of the human α2 cDNA. A synthetic peptide corresponding to the carboxy‐terminus of murine α2 was used to generate α2‐specific antiserum. The antiserum and riboprobes derived from both the α2 cDNA and the previously characterized murine β1 subunit cDNA were used to determine the spatiotemporal expression of the α2 subunit by immunocytochemistry and of the α2 and β1 mRNAs by in situ hybridization. Both approaches gave concordant results. Expression of the α2 integrin subunit was observed in both the maternal and embryonic components of the placenta, namely the perivascular and basal zone decidual cells and decidual cells and spongiotrophoblasts at the maternal/embryonic junction. Expression was also observed in cells actively producing and remodeling the extracellular matrix in the maternal uterus and in the developing gut, lens, cartilage, bone, and tooth of the embryo. Generally, expression of the α2 integrin subunit was found in cells entering their later stages of differentiation such as in chondrocytes as they became hypertrophic, ameloblasts and odontoblasts as they became columnar and began to secrete the matrix of the tooth, endothelial cells after they formed tubules, in the lens just prior to and during lens fiber production, and in the collecting ducts of the kidney only after full gestation. Throughout embryogenesis, β1 mRNA was widely distributed and present in cell types expressing α2 mRNA and protein. The developmental expression pattern of the α2β1 integrin suggests roles for the integrin in placental development and matrix assembly and remodeling. © 1994 Wiley‐Liss, Inc.
Localized epiphyseal dysplasia in offspring of manganese‐deficient rats
Authors: Hurley Lucille S. , Asling C. Willet 
Published: February 2005

AbstractDevelopment of a characteristic localized dysplasia of the proximal tibial epiphysis, occurring in high incidence in offspring of manganese‐deficient rats, was studied. Young of female rats, maintained from weaning on a diet deficient in manganese, were compared with those of females receiving the same diet with manganese supplementation. Epiphyses were studied histologically and in alizarin‐stained specimens. In offspring of deficient females, the proximal tibial epiphyseal ossification center appeared at the normal time (10–12 days). Soon thereafter, abnormalities were observed; in particular, spicules of osseous and marrow tissue connecting the epiphysis to the metaphysis through the epiphyseal plate were seen. By 21 to 48 days of age, all of 19 deficient offspring showed marked abnormalities. In over 30%, the epiphysis seemed absent when viewed from the external aspect; when examined at the internal (split) surface, a tiny epiphysis was found recessed into a pocket‐like depression in the metaphysis and partially fused with it. Even when “pocketing” was incomplete, the epiphysis was small, misshapen, poorly vascularized, fragmented, and showed rarefaction. Bony spicules frequently perforated the narrowed plate. Abnormalities of the cartilage were often seen. Offspring of deficient mothers transferred to the manganese‐supplemented diet late in gestation also showed some defects of this epiphysis. Possible mechanisms related to the pathogenesis of this disorder are discussed, and a hypothesis is proposed.
The calcified zone (basal layer) of articular cartilage of rabbits
Authors: Mankin Henry J. 
Published: February 2005

AbstractIn the mammalian embryo, the articular end of a long bone consists of a mass of fetal cartilage which undergoes transformation into two types of tissue as the animal ages: The hyaline cartilage surface of the adjacent joint; and the bone of the ossific nucleus of the epiphysis. The junction of these two areas, the calcified zone (or basal layer) of the articular cartilage, was studied in the distal femur of 110 albino rabbits of various ages by: tritiated thymidine autoradiography; routine histologic staining and mitotic counts; special stain for glycogen; and special stain for calcium (murexide).In the immature rabbit (under two months) the cartilage cells are arranged in columns and there is evidence of active proliferation. In its most basal portion adjacent to the vascular tufts of the epiphyseal nucleus, the cells are hypertrophic and contain glycogen. The intervening matrix bars are calcified. It is apparent that, at this age, endochondral ossification, indistinguishable from that at the epiphyseal plate, is occurring.In the older rabbit (age four months) proliferation, columniation, and glycogen content are minimal, and the basal layer of cartilage is diffusely calcified. Proliferation is intense in and about the capillary loops and a thin layer of bone surrounds the capillary.In the adult (over six months) rabbit, calcification and ossification predominate. No proliferative activity is noted. Apparently growth has ceased completely or is so slow as to be unmeasurable by available techniques.
Genetic influences on induced cleft palate in different strains of mice
Authors: Loevy Hannelore 
Published: February 2005

AbstractThis paper reports some of the genetic aspects of induced cleft palate susceptibility in the Strong a mouse compared with another less susceptible strain (C3H) and with their intercrosses.Pregnant females were injected with 1.25 mg of cortisone (Cortone acetate Merck) daily on the eleventh, twelfth, thirteenth and fourteenth day of pregnancy and killed on the seventeenth and eighteenth day of pregnancy. The control animals were not treated.In treated animals, cleft palate was induced in 100% of the Strong a offspring and 36.3% in the C3H offspring. In cross matings between these two strains the same dose of cortisone induced 11.7% of cleft palate if the mother was of the Strong a strain and 43.7% if of the C3H strain. The same dose produced cleft palate in 29.7% of the offspring of the F1 generation when mated among themselves and in 42.5% of the white offspring of the F2 generation when mated among themselves.The incidence of induced cleft palate was independent of albinism in the offspring of the F1 and F2 generation. There was no significant correlation between the occurrence of cleft palate and the position in utero, the weight of the affected fetuses or the litter size; however, the more crowded the uterine horn, the more affected fetuses it contained.There was no significant correlation between weight of the mother and number of affected fetuses among her offspring when the effect of litter size was eliminated.
Development of parabiosis intoxication in rat parabionts
Authors: Binhammer R. T. , Epstein S. , Whitehouse A. 
Published: February 2005

AbstractThe development of parabiosis intoxication, primary symptoms of which are anemia of one animal and concomitant hyperemia of the other, was sequentially followed in Holtzman (Sprague‐Dawley) — Charles River (Sprague‐Dawley) parabionts. Hemoglobin and hematocrit determinations, RBC, reticulocyte and WBC counts were done on blood removed from pairs by cardiac puncture. In addition bone marrow total nucleated cell counts were done, systolic blood pressure measurements were taken and cross circulation rates were studied with Cr51 tagged erythrocytes. Intoxication developed rapidly in these distantly related pairs about 10 days after union and terminated in death or breakdown of the union by 21 days. The anemia, which was not limited to one or the other partner, was accompanied by reticulocytosis and normal nucleated bone marrow cell counts indicating no suppression of marrow function. The anemic partner also showed total white cell counts elevated over those in the hyperemic partner at 13 days after union. The partner destined to become hyperemic showed elevated systolic blood pressure concomitant to the change in erythrocyte values suggesting that no causal relation exists between blood pressure and the development of intoxication. Cross circulation rates tested with Cr51 tagged erythrocytes showed slowing of circulation evident as early as nine days after parabiosis. Some pairs maintained circulation rates similar to controls for as long as 15 days, but in the majority cross circulation had virtually ceased by this time.
Adrenergic synaptic vesicles in the anterior hypothalamus of the rat
Authors: De Iraldi A. Pellegrino , Duggan H. Farini , De Robertis E. 
Published: February 2005

AbstractAfter formaldehyde perfusion a small area of the anterior hypothalamus was extirpated, identified neuroanatomically and studied under the electron microscope.The preparative technique consisted in refixation of the piece in 1% osmium tetroxide for two hours, immersion in 2% uranyl acetate and embedding in Epon 812. Sections were stained with lead acetate.The main areas comprised in the tissue were the nucleus hypothalamicus anterior, nucleus periventricularis inferior and anterior hypothalami area.In the neuropiles of these regions varicose axons containing neurotubules and granular vesicles are observed. There are also numerous nerve endings containing typical synaptic vesicles in addition to some having a dense granule of reduced osmium. Measurements demonstrate that there are two different populations of vesicles with means of 510 Å and 1,300 Å respectively.The possible significance of the granular vesicles is discussed and related to the high content of catecholamines in this region of the CNS. The possibility that these nerve endings may synthesize and store more than one transmitter substance is also discussed. The wide variety of vesicles found in axons and synaptic endings of the anterior hypothalamus is also considered as supporting a unified theory of neurosecretion postulated by one of the authors.
An electron microscopic study of the effects of reserpine on adreno‐medullary cells of the syrian hamster
Authors: Yates Robert Doyle 
Published: February 2005

AbstractAdult Syrian hamsters were given daily subcutaneous injections of reserpine (1 mg/kg) for one or three days in order to study the fine structural changes in adreno‐medullary cells. Initial alterations of fine structure in animals given one injection and sacrificed 15 hours later. Hamsters treated for three days were adrenalectomized on the left side 24 hours after the last reserpine injection. Following adrenalectomy, animals were allowed to recover for 48 or 96 hours after which the cells of the right adrenal medulla were compared with those of the left.Medullary cell changes 15 hours following one injection of reserpine included partial loss of electron opaque granules and an increase in the number of cytoplasmic vesicles and vacuoles. Medullary cells from the left adrenal glands removed following three subcutaneous injections of reserpine were characterized by a marked loss of electron opaque granules and by the presence of many vesicles and vacuoles distributed throughout the cytoplasm.Forty‐eight hours following unilateral adrenalectomy medullary cells from the remaining right glands exhibited slightly electron opaque granules within the cytoplasm, each of which was surrounded by a smooth surfaced membrane. Cytoplasmic vesicles and vacuoles had decreased in number. Ninety‐six hours following unilateral adrenalectomy medullary cells from the right glands showed further decreases in numbers of vesicles and vacuoles, and granules which possessed an electron opaqueness comparable to control medullary cells had reappeared within the cytoplasm.
A method for demonstrating subserous lymphatics with hydrogen peroxide
Authors: Parke Wesley W. , Michels Nicholas A. 
Published: February 2005

AbstractThe visualization of the subserous lymphatics of various organs is rapidly accomplished by the topical application of hydrogen peroxide. As the peroxide reacts with a natural inclusion of the lymph, presumably catalase, the vessels are spontaneously inflatedwith free oxygen. This method is much easier to use than injection techniques as fresh material, catheterization of the vessels, or tissue puncture are not required.
Morphological characteristics of the anterior mesenteric artery of fowl
Authors: Ball R. A. , Sautter J. H. , Katter M. S. 
Published: February 2005

AbstractThe anterior mesenteric artery of two species of fowl, the turkey and chicken, is found to differ structurally from the basic pattern observed in other avian arteries and in mammalian arteries in general. This difference in structure lies in the fact that the avian anterior mesenteric artery contains two well‐developed muscular components: an inner circular, and an outer longitudinal, analogous to the arrangement of the muscularis externa of the intestinal wall. However, the evidence presented indicates that the outer longitudinal layer is part of the adventitia. The possible functional significance of this feature is discussed.
The postnatal development and differentiation of the boundary tissue of the seminiferous tubule of the rat
Authors: Leeson C. Roland , Leeson Thomas S. 
Published: February 2005

AbstractThe morphology of the boundary tissue of the seminiferous tubule of the rat has been investigated in testes from animals aged from birth to four months. In the adult, the boundary tissue consists of four layers: (1) an inner non‐cellular layer comprising a network of collagen fibrils sandwiched between two basement membranes (2) an inner cellular layer of flattened cells showing many of the characteristics of smooth muscle, including intracytoplasmic filaments and micropinocytotic vesicles, (3) an outer non‐cellular layer containing scattered colagen fibrils and associated usually with a single basement membrane and (4) an outer cellular layer, component cells of which contain no fine filaments. At birth, the seminiferous tubule rests upon a basement membrane which separates it from a layer of low cuboidal cells. External to this, there is a narrow intercellular zone containing scattered fibrillar material and a region consisting of numerous processes of mesenchyme cells. By ten days postnatal, four definite layers are established due to the differentiation of an outer cellular layer of flattened cells from the mesenchyme, and intracytoplasmic filaments have made their appearance within the inner cellular layer. In subsequent stages there is progressive thinning and specialization of the cellular layers and increased fibril content within the non‐cellular layers. By 22 days postnatal the boundary tissue appears virtually adult in morphology.
Electron microscopy of post‐mortem changes in the rat myocardium
Authors: Hibbs Richard G. , Black William C. 
Published: February 2005

AbstractAn electron microscopic study was made on specimens of rat myocardium taken at various intervals after death, in order to determine the extent and character of autolytic change occurring during the first ten hours. Specimens were taken immediately after death and at 15 minutes, one hour, three hours, five hours and ten hours after death, fixed in 1% phosphate‐buffered osmium tetroxide and examined with the electron microscope.The first noticeable change was a rapid depletion of glycogen. The specimens taken one hour or more after death show a longer sarcomere length indicating a more relaxed state. This is believed to reflect the inability of these fibers to contract upon stimulation by the initial contact with the fixative. Nuclei, when encountered, showed more chromatin clumping than in fresh tissue, but the nuclear membranes were intact.Very little change was noted in the mitochondria, sarcoplasmic reticulum, or other cellular components.
Lipid‐depleted white adipose cells: An electron microscope study
Authors: Napolitano Leonard , Gagne Harriet T. 
Published: February 2005

AbstractThis report presents an electron microscope study of white adipose cells depleted of their lipid inclusion by prolonged low food intake. The tissue was fixed in phosphate‐buffered 1% osmium tetroxide, embedded in Vestopal W, and sections were stained with lead hydroxide. Such cells differ in shape and size from signet‐ring cells. They are ovoid, diminished in size, and the cell surface has become indented in all planes of the cell. The intercellular space is expanded with concentrations of collagen fibers in close association with the cell surface. These changes are presumed to be mechanical events associated with loss of lipid from the cell. Subcellular changes include the appearance of an extremely large number of pinocytotic vesicles and cytoplasmic vesicles similar in appearance, membrane‐bound dense bodies, five‐layered membranous structures, vesiculated bodies, and areas of flocculent material. Mitochondria and nuclei appear to be similar to their counterparts in signet‐ring cells. Observations are discussed with relation to ultrastructural changes reported in other studies in which adipose cells were depleted of fat by acute starvation or experimental deprivation of insulin. It is suggested that intracellular structural changes are probably associated with adaptive alterations in the metabolism of the cell.
Intraneuronal capillary
Authors: Cammermeyer Jan 
Published: February 2005

AbstractMale rabbits, subjected to transection of the facial nerve, were narcotized and fixed by a two‐step perfusion procedure with a modified Heidenhain's Susa solution. The autopsy was delayed four hours or more. Serial sections of the rhombencephalon were stained with periodic acid‐Schiff and gallocyanin.The course of a capillary through the perikaryon of three facial motor neurons is established beyond doubt by the study of companion sections with series of photomicrographs. The capillary is only partly in contact with the cytoplasmic membrane in its passage through the neuron.This form for neuronal blood supply must be regarded as extremely rare. Previously, it has been unequivocally depicted in a single large pyramidal neuron of the human cerebral cortex.
Localization of thalamic projection of afferents from the tongue in the cat
Authors: Emmers Raimond 
Published: February 2005

AbstractNeuroanatomical nuclear configuration corresponding to the projection regions for the chorda tympani, the IXth, and the lingual nerves was studied in the cat thalamus by a combination of electrophysiological, stereotaxic, and histological techniques. Each of the three nerves innervating the tongue was dissected for stimulation in cats deeply anesthetized with Nembutal. Maps of the extent of the thalamic projection for a particular nerve were obtained by recording evoked potentials in the thalamus during the stimulation of one of these nerves. Such maps were correlated with the anatomical structures of the cat thalamus by reconstructing the recording sites from histological sections of the cat brain. It was found that the chorda tympani and the IXth nerve projection regions correspond closely to the ventromedial nuclear complex with slight encorachment on the lingual nerve projection region in the ventrobasal complex. The most medial portions of the taste nerve projection regions do not relay any tactile afferent impulses and the most lateral portion of the lingual nerve projection is not activated by impulses in the taste nerves. Therefore, it is suggested that the thalamic relay of taste is not coextensive with other lingual modalities in the cat thalamus but it has an independent representation in the ventromedial nuclear complex.
Effect of transplacental mitotic inhibitors on the fetal hamster eye
Authors: Ferm Vergil H. 
Published: February 2005

AbstractCongenital malformations of the hamster eye, consisting of microphthalmia and anophthalmia have been noted consistently in the offspring of pregnant hamsters treated with intravenous injections of colchicine, Vinacaleukoblastine (VLB) and Vincristine (VCR) on the eighth day of gestation. In an attempt to compare the mitotic‐arresting activity of these three compounds on the lens and retina of the fetal hamster eye, various concentrations of the drugs were injected into pregnant hamsters on the fourteenth day of gestation and the fetuses recovered after three hours. Mitotic counts were done on comparable sections of lens and retinas of the fetuses. Colchicine has the most marked mitosis‐inhibiting activity of these three drugs. The most effective mitosis‐inhibiting dosage of colchicine also correlates with its most effective teratogenic dose. VLB and VCR do not inhibit mitosis in the fetal hamster eye as markedly as colchicine and their most effective mitosis‐inhibiting dosages are equal to or above levels which cause a 95–100% embryonic mortality. It is possible that some common biological mechanism other than inhibition of mitosis may be responsible for the similar teratogenic activity of these compounds. The natural resistance of the golden hamster to colchicine does not appear to be manifest in the developing embryos in utero.
Studies on the perifollicular region of the rat's spleen
Authors: Snook Theodore 
Published: February 2005

AbstractA marginal sinus, formed by the anastomosed terminations of white pulp capillaries, bounds the inner edge of the marginal zone. The endothelial lining on the nodular surface is complete. Pores appear along the lateral aspect thus allowing blood to pass freely into the interstices of the marginal zone. A dense aggregation of Marshall's metalophil cells occurs in the region of the marginal sinus. Such cells are lacking in the marginal zone.Intravenous injections of particulate matter were used to determine the course of blood flow and phagocytic potential. Ten minutes after injections, particles were found to be dispersed among the cells of the marginal zone. None were found in the marginal metalophils. In four hours the particles had cleared the marginal zone and were within red pulp macrophages. In a few rats, the marginal metalophils reacted positively to tests for iron. It is concluded that marginal metalophils represent a large reserve of potential phagocytes situated at a point where blood first leaves capillaries to enter tissue interstices.