bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sperm maturation in the male reproductive tract: Development of motility
Authors: Gaddum Penelope 
Published: February 2005

AbstractRabbit spermatozoa were removed from various levels of the male reproductive tract. They were examined in Hanks' solution at room temperature with a phase contrast microscope and their motility characteristics were recorded cinematographically.Spermatozoa from the seminiferous tubules and ductuli efferentes show weak, vibratory movements with no forward progress. Little change in motility occurs until the sperm reach the flexure of the caput epididymidis where some are capable of moving more vigorously in a circular fashion. Samples from the distal caput epididymidis show a sudden increase in sperm activity and a consistent pattern of tight, circular movement. As the sperm traverse the corpus epididymidis, increasing numbers show progressive, forward movement with longitudinal rotation. The proportion of such sperm becomes significant only in samples from the upper cauda epididymidis and more distal regions. Sperm from the ductus deferens rarely retain the circular movement.It is concluded that rabbit spermatozoa undergo a distinct sequence of changes in their swimming movements as they mature in the epididymis. A similar change was noted in epididymal spermatozoa from the rat and guinea pig suggesting that this process is fundamental to sperm maturation in several species.
The jejunal absorptive cell of the newborn pig: An electron microscopic study
Authors: Staley Theodore E. , Jones E. Wynn , Marshall Arvle E. 
Published: February 2005

AbstractThe morphology of the intestinal absorptive cell in the newborn pig is strikingly different from that of the three‐week‐old pig. The former's unusual characteristics are: a poorly developed hirsute layer over the microvilli, an abundance of pinocytotic vacuoles and apical tubules, and a subnuclear location of the Golgi apparatus. In unfed newborn pigs the morphology does not change appreciably by 42 hours. Spinous processes line the apical tubules which may be associated with protein absorption. The retention of the tubular system in the absence of feeding (for 42 hours) and its disappearance with feeding, lends support to the concept that this system is important in the absorption of protein macromolecules in the newborn pig. The position of the Golgi may be instrumental in regulating the ability of the cell to absorb large molecular weight proteins.
Bony trabecular changes in the human mandibular ramus from prenatal period to adulthood
Authors: Herzberg Fred , Dovitch Victor 
Published: February 2005

AbstractThe rami of eight human mandibles ranging in age from six months prenatal to adulthood were studied radiographically and by matte acetate tracings. The characteristic trabecular pattern seen in the adult ramus was not found until the fifth year of life. A disorganization of the pattern occurred at nine years of age, but was re‐established by the twelfth year. The changes in pattern observed appear to be related to the eruption times of the teeth, which probably modify the muscular stresses exerted on the bone in the process of mastication.
Occurrence of fluorescent granules in the Purkinje cells of the cerebellum
Authors: Sarnat Harvey B. 
Published: February 2005

AbstractWhen examined in the fluorescence microscope, cells of the central nervous system exhibit intense, yellow, naturally fluorescent granules throughout their cytoplasm. In the mouse, cat and man, the granules are absent at birth and present in adults. A study of the development of these granules in the Purkinje cells of the cerebellum was made in the mouse and cat. There is a rapid increase in the number of fluorescent granules in postnatal life. The granules probably represent lysosomes.
The use of oxone to facilitate specific tissue stainability following osmium fixation
Authors: Sevier A. C. , Munger B. L. 
Published: February 2005

AbstractThe specific stainability of 1–3 μ thick sections of tissue prepared for electron microscopy after glutaraldehyde and osmium fixation and araldite embedding is greatly enhanced after oxidation with Oxone. This monopersulfate has been found to leave tissue section in a suitable condition for applying a trichrome stain as well as a specific silver impregnation. These methods are described in detail. The mode of action of Oxone is poorly understood.
Ultrastructural and histochemical studies on the innervation of the mucous membrane of the mouse colon
Authors: Silva Douglas G. , Farrell K. E. , Smith G. C. 
Published: February 2005

AbstractUltrastructural and histochemical studies have revealed that the mouse colonic mucous membrane receives an extensive autonomic innervation. Nerve fibers enter the mucous membrane through the muscularis mucosae and ramify in the lamina propria where they were often seen in close proximity to smooth muscle cells. Other axons were seen accompanying blood vessels or passing along the basal aspect of the epithelium subjacent to the basement membrane; none were seen either entering the epithelium or within it.Several methods of fixation were employed in order to study their effects on intraaxonal vesicles. It was found that in tissue fixed in either glutaraldehyde in phosphate buffer, or in osmium tetroxide in phosphate buffer, the granular vesicles were better preserved than in tissue fixed in a chrome‐osmium tetroxide mixture. The nerve fibers contained mainly agranular vesicles and large granular vesicles (600–1700 Å). Small granular vesicles (300–600 Å) usually associated with adrenergic nerves and specific green fluorescence indicative of catecholamines were only occasionally seen in the mucous membrane. Reserpine depleted the small granular vesicles and also abolished specific fluorescence.Ultrastructural studies showed that the large majority of nerve fibers were acetylcholinesterase positive.These findings indicate that the innervation of the colonic mucous membrane is predominantly cholinergic and that the adrenergic innervation is sparse.
Fertilization and early development in the Chinese hamster, Cricetulus griseus
Authors: Pickworth Stella , Yerganian G. , Chang M. C. 
Published: February 2005

AbstractEggs from 79 Chinese hamsters, Cricetulus griseus, were examined at various times from before ovulation on the day of mating (Day 0) to implantation (Days 5–6). The animals were kept under reversed lighting (dark period 8 AM to 8 PM). Ovulation occurred between approximately 4 and 6 PM; mean number of eggs recovered per female was 7.6 ± 0.2. Sperm penetration was almost complete by midnight on Day 0. Of 131 eggs collected on Days 1–4, 102 (78%) were fertilized; (females without fertilized eggs excluded). The midpiece and tail of the fertilizing sperm were found in the cytoplasm of only 9% of pronuclear or cleaved eggs, and remained in the perivitelline space of 74%; in the other 17% eggs the sperm tail and most of the midpiece were outside the zona pellucida or were missing at recovery. No polyspermic eggs were found.The first three cleavages took place at 20–26 hour intervals after ovulation. Eggs reached the blastocyst stage in the oviduct and entered the uterus more than 96 hours post‐ovulation. Implantation occurred between Days 5 and 6.
Histological, histochemical, and cytological observations on the adrenal gland of the wild white‐footed mouse, Peromyscus leucopus
Authors: Costa Jonathan L. 
Published: February 2005

AbstractSeveral cytological features of the adrenal gland of the wild whitefooted mouse, Peromyscus leucopus, are described. Nuclei of cortical cells vary widely in size. Medullary cells may be divided into two populations: one with cytoplasm staining intensely with basic dyes and the other with faintly‐staining cytoplasm. Photometric measurements of the DNA content of Feulgen‐stained cortical nuclei show many nuclei containing 4C and 8C amounts of DNA. The distribution of the polyploid nuclei varies in different adrenal zones. Nuclei in the zona glomerulosa are almost all 2C. A majority of those in the zona fasciculata are 4C and 8C. Those in the zona reticularis fall predominantly into a 2C class, with some 4C and 8C nuclei. Groups of formalin‐fixed medullary cells staining intensely with hematoxylin, toluidine blue O, and azure B correspond in location, arrangement, and morphology to those indicating the presence of epinephrine by several histochemical techniques. The substances responsible for the basophilia may be acidic proteins rich in carboxyl groups, since (1) RNase treatment does not appreciably diminish the basophilia; (2) all medullary cells are only faintly PAS‐positive; and (3) the staining behavior of the more basophilic cells, when exposed to azure B solutions buffered to acid pH's, follows that to be expected when this dye is bound by tissue carboxyl groups.
The effects of phytohemagglutinin on the growth and histochemical properties of mammalian cells in tissue culture
Authors: Caso Louis V. 
Published: February 2005

AbstractPhytohemagglutinin‐P (PHA‐P) exhibited inhibitory action on the growth of two human epithelioid cell lines, HeLa and L‐132, and on the L‐929 strain of mouse fibroblasts. Growth of stationary cultures was measured spectrophotometrically by DNA production after 96 hours incubation. The mitotic indices of the three cell lines were reduced significantly by PHA‐P after 72 hours incubation.Histochemical studies demonstrate depressed production of cytoplasmic RNA in 72‐hour HeLa cultures after treatment with PHA‐P, with the appearance of prominent, PAS‐positive, diastase‐fast granules in the cytoplasm. Bound lipid aggregates increased in amount in the cytoplasm of HeLa cells after PHA‐P treatment. The PAS‐positive, diastase‐fast granules were also found in the cytoplasm of the L‐132 and L‐929 cell lines after treatment, but cytoplasmic RNA remained unchanged qualitatively. Alkaline phosphatase was slight in amount in HeLa cells and was reduced to trace amounts after PHA‐P treatment. L‐132 cells showed moderate to heavy concentration of alkaline phosphatase, which remained unchanged qualitatively after PHA‐P treatment. The enzyme could not be demonstrated in the L‐929 fibroblasts.
Fenestrated cisternae in the Golgi apparatus of the epididymis
Authors: Flickinger Charles J. 
Published: February 2005

AbstractAttention is directed toward the occurrence of fenestrations or pores in Golgi cisternae of rat and mouse epididymis. There is a gradation in the degree of cisternal fenestration within a Golgi complex. Cisternae at the convex pole are highly flattened and contain few pores, but those near the concave side are distended and exhibit a large number of roughly circular fenestrations 300–600 Å in diameter. Cisternae in the middle of a stack often have an unperforated central portion that is surrounded by a fenestrated and expanded peripheral region. The structure of these Golgi complexes is compared with previous descriptions of Golgi cisternae, particularly the fenestrated cisternae reported in plant cells.
The presence of fenestrated capillaries in the papillary layer of the enamel organ
Authors: Garant Philias R. , Gillespie Roberta 
Published: February 2005

AbstractThe capillary network of the papillary layer of the enamel organ was studied with the electron microscope. Mandibular incisor teeth of ten‐day old Swiss albino mice were fixed in formaldehyde‐glutaraldehyde, postfixed in osmium tetroxide and prestained with 0.5% uranyl acetate prior to being embedded in Epon. Examination of ultrathin sections revealed the presence of fenestrations approximately 500 Å to 700 Å in diameter within the most attenuated regions of the capillary walls. In most instances the fenestrations appeared to be closed by diaphragms usually consisting of a thin membrane with a thicker centrally located button of electron opaque material.The presence of fenestrated capillaries within the papillary region of the enamel organ lends further support to the concept that papillary cells are engaged in transport functions during the maturation of enamel.
Early development of thymic lymphocytes in mice, studied by light and electron microscopy
Authors: Hoshino Takeshi , Takeda Masako , Abe Kazuhiro , Ito Takashi 
Published: February 2005

AbstractThymic rudiments from mouse embryos varying in gestational from 10–13 days were examined by light and electron microscopy in an effort to learn the origin of thymic lymphocytes. Lymphocytes were recognized and distinguished from mesenchymal cells and thymic epithelial cells by their round shape, larger nucleoli, and high concentration of cytoplasmic ribosomes and dearth of endoplasmic reticulum. No lymphocytes could be found at the earliest stage of development of the third pharyngeal pouch — at approximately ten days' gestational age. They first appeared in the mesenchyme surrounding the third pouch at a later stage, (approximately 11 days' gestation), but in most cases did not appear in the thymic epithelium until the parathyroid and thymus began to differentiate at approximately 12 days' gestation. No cells were seen that appeared to be transitional between lymphocytes and epithelial or mesenchymal cells and it was concluded that these observations support the hypothesis that lymphocytes first reach the thymic parenchyma by immigration from the surrounding mesenchyme. Most of the lymphoctyes found in the region of the thymus at these stages of development were large lymphocytes. The origin of these early lymphocytes remains unknown.
The significance of intramedullary cancellous bone formation in the repair of bone marrow tissue
Authors: Amsel S. , Maniatis A. , Tavassoli M. , Crosby W. H. 
Published: February 2005

AbstractThe repair of hemopoietic bone marrow following evacuation of the tibial or femoral cavity of the rat was sequentially studied with the light microscope. A stereotyped train of histologic events occurred. These were capillary invasion of the cavity, appearance of primitive mesenchymal cells, osteoblastic proliferation, cancellous bone formation, development of sinusoids, reappearance of hemopoietic tissue and resorption of cancellous bone. The studies suggest that restoration of marrow sinusoids takes place only in the interstices of cancellous bone. Mechanical disruption of the sinusoidal system is one method of triggering cancellous bone formation. The cancellous bone which appeared after injury was thought to be produced by endosteal osteoblasts and osteoblasts derived from cells residing in normal hemopoietic tissue. Localized radiation of the tibia followed by mechanical disruption of hemopoietic tissue demonstrated that cancellous bone production and the repair process were unimpaired by 1,000 r but were completely blocked by 4,000 r. This would imply that the cell which can differentiate into an osteoblast is resistant to 1,000 r.
The trigemincd nerve root with special reference to the central‐peripheral transition zone: An electron microscopic study in the macaque
Authors: Maxwell David S. , Kruger Lawrence , Pineda Anselmo 
Published: February 2005

AbstractThe entry zone of trigeminal sensory root fibers displays a “glial dome” covered by a basal lamina. This zone constitutes the “fibrous cone” of gross descriptions of the root and demarcates a sharp transition from peripheral to central nervous system. The dome consists of closely interwoven astrocyte processes, and appears to be identical to the subpial astrocyte meshwork elsewhere in the central nervous system. In the peripheral portion of the root, axons are surrounded by Schwann cells; those associated with myelin sheaths display distinctive laminar inclusions and pinocytotic vesicles lacking in Schwann cells which surround unmyelinated axons. In the peripheral region, separate and distinct endoneurial and perineurial layers of collagen could not always be identified. In the central part of the root, Schwann cells, fibroblasts, and collagen are absent and from the point of transition, the axons are principally surrounded by astrocytes. Oligodendrocytes are relatively rare in the transitional zone. The axonal transition from central to peripheral, occurs at nodes of Ranvier where the basal lamina of the dome is continuous with the basal lamina of the Schwann cell of the last peripheral internode. Some “islands” of glial tissue are interspersed in the root and ganglion but it was not established if these are completely discontinuous with the central “glial dome.” No ganglion cells have been found in such “islands,” nor in the glial dome.
Spontaneous calcification in hearts of DBA mice
Authors: Nabors Charles E. , Ball Carroll R. 
Published: February 2005

AbstractOnset, frequency and characteristics of the spontaneous calcification which occurs in hearts of mice of the DBA strain have been studied. Calcified myocardial lesions developed as early as 25 days of age. A limited inflammatory response was associated with the fine mineral granules of early lesions. With age, sites of calcium deposition became larger and agranular. There was no evidence of inflammation at such loci and adjacent connective tissue did not increase significantly. In the oldest animals (older than 90 days), fibrous encapsulation of calcified sites was typical. Calcareous epicarditis appeared by 30 days; was minimal (8%) through 90 days, and then rose sharply in incidence (50%) in older animals. Epicardial calcification was restricted to the right ventricle. In general the calcified lesions increased with age and were not related to sex. Incidence of all lesions was 17% by 30 days of age, 80% within 90 days, and 94% in mice older than 90 days.
The pelvis of the free‐tailed bat: Sexual dimorphism and pregnancy changes
Authors: Crelin E. S. , Newton E. V. 
Published: February 2005

AbstractThere are constant morphological differences between the bony pelves of adult males and females that constitute a sexual dimorphism. A convexity along the caudal border of the ischiopubic ramus and a bony projection bordering the pubic joint are present only in the male. The pubic joint in the male is a typical symphysis, whereas in the female it consists of an interpubic ligament interconnecting the coxal bones. The ligament contains an abundance of elastic fibers interspersed among collagenous fibers. The disparity between the size of the pelvic birth canal of the pregnant bat and the single full‐term fetus is so great that during parturition the interpubic ligament stretches to more than 15 times its original length.
Insertions of intrafusal fibers in muscle spindles of the cat and other mammals
Authors: Bridgman Charles F. , Shumpert Edmond E. , Eldred Earl 
Published: February 2005

AbstractThe manner of insertion of intrafusal (IF) fibers of muscle spindles has been studied in serial histological sections of spindles from hindlimb muscle of the cat, opossum, mouse, rat, bat and gibbon. Four basic types of IF terminations in relation to the capsule were recognized: (A) direct insertion into the capsule; (B) strong lateral attachments to the capsule, though the fiber may continue beyond the capsule; (C) termination in the connective tissue beyond the limits of the capsule; (D) free extension of the fiber beyond the capsule. Bag fibers in all species generally extended beyond the capsule. The pattern of chain fiber insertion, however, varied with the species. Most rat spindles, for example, followed the D pattern, those in the cat pattern A, and the gibbon chiefly A and B. The bearing of these findings upon a postulated mechanism by which spindles may detect intramuscular pressures, as changes in length, is discussed.
Fine structure of the dermal luminescent organs, photophores, in the fish, Porichthys notatus
Authors: Strum Judy May 
Published: February 2005

AbstractPhotophores in Porichthys notatus consist of a cellular lens, an underlying area of photogenic tissue and a deep ensheathing reflector. Lens cells exhibit a dense compacted filamentous cytoplasm. Their processes interdigitate and desmosomes exist along their borders. The photogenic tissue, richly supplied by blood vessels, consists of two main cell types: (1) a presumed “photogenic” cell; and (2) a supportive cell. Photogenic cells are characterized by a highly vesiculated cytoplasm and peripheral microvilli. Frequently, they exhibit lamellar membranous whorls. Some whorls display cytoplasmic cores with vesicles. Many of these vesicles communicate via pores with an extracellular channel that envelops the cells. Supportive cells contain cytoplasmic filaments and extend processes around the photogenic cells. Except for isolated desmosomal contact points, a wide extracellular channel intervenes between supportive and photogenic cells. A prominent basal lamina separates supportive cells from the surrounding connective tissue. The strongly birefringent reflector is composed primarily of cells containing guanine crystals. The crystals lie stacked in groups, each membrane‐bounded crystal being separated from its neighbor by an intervening layer of cytoplasm. Such an arrangement produces constructive interference and accounts for the high reflectivity of this multilayered structure. Possible relationships of the above structural features and the production of light are discussed.
Ultrastructure of the placenta and fetal membranes of the dog I. The placental labyrinth
Authors: Anderson John Walberg 
Published: February 2005

AbstractThe ultrastucture of the canine placental labyrinth has been studied at 40 to 60 days of gestation. Cytotrophoblasts persist in an undifferentiated state throughout gestation, with numerous polyribosomes and little rough endoplasmic reticulum, with expanded cisterns containing flocculent precipitate. Fetal capillaries progressively invade the syncytium, without, however, penetrating the basal lamina. Maternal decidual cells are reported here for the first time in this species. The maternal endothelium is considerably hypertrophied, with many profiles of membranous organelles; but there is consideriable thinning of this endothelium between 50 and 60 days. The interstitial membrane intervenes between trophoblast and maternal endothelium, often forming the thickest part of te barrier at 60 days. the definitive endotheliochorial condition is confirmed; and the thinnest barrier is about 1 μ.
A study of the cardiac innervation in domestic animals: Cattle
Authors: McKibben John Scott , Getty Robert 
Published: February 2005

AbstractThe cardiac innervation of cattle was morphologically dissected and described. Descriptions of the ganglia of origin as well as the course and distribution are presented. Sympathetic nerves arose from the thoracic and cervicothoracic ganglia, but unlike those of the horse, dog and cat did not arise from the more cranial situated cervical ganglia. Most left thoracic and some cervicothoracic cardiac nerves passed through a cardiac ganglion of the left intervascular triangle before being distributed to the heart. Parasympathetic cardiac innervation arose from the vagi, both cranial and caudal to the origin of the recurrent laryngeal nerve, and from the recurrent laryngeal nerves themselves. Left heart nerves primarily supplied the area along the coronary groove caudally and on the right side. This included the area of the coronary sinus and atrioventricular node. Left cardiac nerves also extended along the right coronary artery. Both left and right cardiac nerves passed to the cardiac plexus and also along the descending and circumflex branches of the left coronary artery on the left side. Right cardiac nerves extended primarily between the venae cavae or between the caudal vena cava and left atrium to the area of the sinoatrial node but also into the area of the coronary sinus and atrioventricular node.