bluuebunny/crossref_metadata_2025 huggingface dataset:
Descending inputs to caudal cochlear nucleus in cats: A horseradish peroxidase (HRP) study
Authors: Kane Eileen S.
Published: February 2005

After HRP injections into the octopus cell area of the cat cochlear nucleus, only periolivary neurons of the superior olivary complex (SOC) reacted. Elongate neurons in the lateral periolivary nuclei (ipsilateral to the injection) and multipolar neurons in ventromedial periolivary regions (contralateral to the injection) contained granules. No neurons in the main SOC nuclei or higher auditory nuclei reacted, despite a wide range of HRP concentrations. Thus, neurons from the SOC to the octopus cell area of the cochlear nucleus seem to be entirely periolivary and not entirely equivalent to neurons providing collaterals to the olivocochlear bundle.
Tannic acid as an electron‐dense probe in the testis
Authors: Aoki Agustin , Einstein Jill , Fawcett Don W.
Published: February 2005

The use of tannic acid to preserve and promote the staining of protein constitutents of the extracellular fluid is described. Its usefulness for delineating the extracellular compartment and detecting changes in capillary permeability is illustrated in experiments on the testis.
Myelinated nerve cell bodies in the dorsal horn of the monkey (Saimiri sciureus)
Authors: Beal John A. , Cooper Margaret H.
Published: February 2005

While observing electronmicroscopic preparations of laminae I–III of Rexed (1952), taken from the lumbosacral region of squirrel monkey spinal cord, several small neuronal cell bodies were found which were partially or completely encircled by compact myelin sheaths of varying thickness. Though found in all three laminae, the occurrence of these perikaryal sheaths was less frequent in the “inner zone” of lamina II where there were few myelinated fibers. Perikaryal profiles which were completely surrounded by myelin exhibited neither internal mesaxons nor external tongue processes and the origin of their myelin is obscure. In cases of partially enveloped cells the myelin was often clearly derived from extensions of myelin sheaths surrounding small‐diameter axons. These overgrowths of myelin extended away from their axons at a pole near their internal mesaxon and spread out across the surface of neighboring nerve cells. In some cases the extensions were derived from the entire axonal sheath while in others only the external lamellae were included. The external tongue process, when observed, was located at the distal end of the axonal myelin extension. Overgrowths of axonal myelin which were unrelated to neuronal cell bodies were also found but these formations were less extensive.
Electron microscopic immunohistochemical localization of vasopressin and neurophysin in the median eminence of normal and adrenalectomized rats
Authors: Dube Donald , Leclerc Rachel , Pelletier Georges
Published: February 2005

Using an immunoperoxidase technique at the ultrastructural level, vasopressin (VP) and neurophysin (NP) were localized in the axons of the median eminence of normal and adrenalectomized rats. Whereas VP and NP were generally found in 150‐nm granules in the internal zone of the normal rat median eminence, in the adrenalectomized rat, many granules of about 80 to 100 nm in diameter were found to contain NP and VP in the external zone of the median eminence.
Formation of packaging units in cricket late spermatid nuclei as visualized by spreading techniques
Authors: Tres Laura L. , Kierszenbaum A. L.
Published: February 2005

The nuclear organization of a particular step of cricket late spermiogenesis was examined by an electron microscope study of spermatids dispersed by air‐liquid surface tension. Cell spreading techniques facilitate a display of condensing spermatid nuclei sufficient to allow interpretation of chromatin packaging processes. Results indicate that nuclei of late developing cricket spermatids are integrated by multiple packaging units as the result of an orderly aggregation of individual chromatin fibers. Each packaging unit consists of a thick fascicle, formed by the alignment of smooth chromatin fibers, which frays out into tassels of looped fibers.
The systemic arterial pattern of the guinea pig: The pelvis and pelvic limb
Authors: Stump John E. , Shively Michael J.
Published: February 2005

The systemic arterial pattern of 59 guinea pigs was examined by dissection, angiography, or corrosion casting. The blood supply to the pelvis and the pelvic limbs arises as two terminal branches of the aorta, the right and left common iliac arteries, and each of these divides into external and internal iliac arteries. Their pattern of distribution resembles a typical mammalian pattern. The external iliac artery passes through the body wall to supply the pelvic limb and the internal iliac artery is distributed primarily to the pelvic region and its viscera.
Melatonin induction of testicular recrudescence in hamsters and its subsequent inhibitory action on the antigonadotrophic influence of darkness on the pituitary‐gonadal axis
Authors: Reiter Russel J. , Vaughan Mary K. , Rudeen P. Kevin , Philo Ronald C.
Published: February 2005

Exposure of adult male hamsters to light‐dark (LD) cycles of 0:24 (in hours) for 12 weeks induced atrophy of the testes and accessory sex organs and a drop in immunoreactive pituitary and plasma prolactin levels. The subsequent exposure of these hamsters to LD 14:10 cycles caused regeneration of the sexual organs and an increase in pituitary LH and prolactin levels. Likewise, the weekly treatment of dark‐exposed hamsters with subcutaneous melatonin‐beeswax pellets led to regeneration of the peripheral reproductive organs and an increase in pituitary LH and prolactin levels. After gonadal regeneration, complete darkness failed to induce atrophy of the reproductive system indicating that either long photoperiods or melatonin treatment cause the pituitary‐gonadal axis to be refractory to the inhibitory influence of darkness.
The fine structure of the digital corpuscle of the mouse toe pad, with special reference to nerve fibers
Authors: Idé Chizuka
Published: February 2005

Digital corpuscles in the dermal papillae of the mouse toe pad have been studied using light and electron microscopy of serial thick and thin sections, and silver impregnations of frozen sections. These corpuscles are ellipsoid in shape and approximately 10–30 μm in diameter. They consist of one to three lamellar cells, nerve fibers and a capsule. These digital corpuscles are regarded as small Meissner corpuscles. The capsule is perineural epithelium. One or two myelinated nerve fibers and occasionally an unmyelinated nerve fiber enter the corpuscle. The axon terminals contain many mitochondria and a variable population of vesicular profiles. These terminals are ellipsoid or discoid in shape with the long axis parallel to the skin surface. The cytoplasmic plates (or lamellae) of the lamellar cells are arranged parallel to the skin surface, as is the cleft between the bilaterally symmetrical stacks of lamellae. Small processes extend from the expanded terminal of the neurite into the cleft between the lamellae. The relationship of the neurite terminal and associated lamellar cells resembles in some respects the organization of the inner core of Pacinian corpuscles. Intraepidermal fibers derived from myelinated neurites of the corpuscle may extend to the superficial epidermis. Intraepidermal fibers derived from unmyelinated neurites usually terminate in the basal regions of the epidermis.
Effects of Rous Sarcoma Virus on the synthetic programs of chondroblasts and retinal melanoblasts
Authors: Roby K. , Boettiger D. , Pacifici M. , Holtzer H.
Published: February 2005

Chondroblasts and retinal melanoblasts have been transformed with a temperature‐sensitive Rous Sacroma Virus. At permissive temperature the transformed cells do not display their unique phenotypic properties. When such transformed cells are shifted to non‐permissive temperature they do display their unique phenotypic properties.
Identification of challenged subarachnoid free cells
Authors: Merchant Randall E. , Low Frank N.
Published: February 2005

Three distinct types of free cell contours are recognizable in scanning electron microscopy (SEM) on the leptomeningeal sheaths of dogs twelve days after an intrathecal injection of bacillus Calmette‐Guerin (BCG). Macrophages possess abundant plasmalemmal blebs which are shown in transmission electron microscopy (TEM) to be composed of large membrane‐bound vacuoles. Smooth surfaced lymphoblasts exhibit many basal microvilli that rest upon and often indent the plasmalemma of an underlying pial cell. Neutrophils display many microvilli over their rounded, chrysanthemum‐like surfaces. The consistency with which these external features are expressed suggests that each cell type possesses characteristic surface topography, at least under these conditions of challenge.
The effect of HCG on pinocytosis within the canine inter‐sertoli cell tight junction. A preliminary report
Authors: Connell Carolyn J.
Published: February 2005

The role of tight junctions in permeability barriers is now well established. Other roles for this junction have been postulated, but have not been demonstrated. In both adult and prepubertal dogs, stimulation with human chorionic gonadotropin (hCG) results in an increased number of pinocytotic vesicles on the membrane faces enclosed by tight junctions within the inter‐Sertoli cell junctions of the testis. It is suggested that these membranous regions, protected from the normal flow of intercellular fluids, may act as regions of selective intercellular exchange.
A retropharyngeal approach to the avian brain stem
Authors: Vielvoye G. J. , Freedman S. L. , Voogd J.
Published: February 2005

The surgical steps used to expose the ventral surface of the chicken's rhombencephalon are detailed. Both acute and chronic experimental preparations can be obtained with this technique. Text material and illustrations provide information on the morphological relationships of the brain stem, skull and other significant structures encountered during the operative procedure.
The assessment of prenatal age from the crown‐rump length determined ultrasonically
Authors: Drumm J. E. , O'Rahilly R.
Published: February 2005

Crown‐rump lengths determined ultrasonically in vivo and in utero in cases of known postovulatory age (33–86 days) agree well with those in length/age tables in current embryological usage. Within the embryonic period proper, however, for a given age, the ultrasonic lengths are usually 1 to 5 mm longer than those of fixed specimens. The probable reasons for this are discussed.
A histochemical study of aldehyde fuchsin‐positive material and “high‐esterase cells” in the pineal gland of the Mongolian gerbil
Authors: Japha Joan L. , Eder Thomas J. , Goldsmith Eli D.
Published: February 2005

The pineal gland of the Mongolian gerbil consists of a superficial gland, stalk and deep pineal. The deep pineal differentiates postnatally.

Histochemical studies of the superficial pineal gland indicate that it may be involved in the secretion of protein. Presumptive secretory material visualized by aldehyde fuchsin (AF) and chrome hematoxylin was observed along the course of blood vessels and among the pinealocytes. The distribution and texture of the AF‐positive material was distinctive. It did not correspond to the pattern and texture of material stained with PAS, Sudan Black or acid orcein. Staining with AF was markedly reduced after incubation with trypsin, indicating that the AF‐positive material is at least partially protein. The amount of stainable material increased with age.

The AF‐positive material was observed in what appeared to be interstitial or glial cells and processes, and in the processes of perivascular cells.

Cells and fibrous processes with high non‐specific esterase activity (“highesterase cells”) were observed among the pinealocytes and along the course of blood vessels. The distribution of the “high‐esterase cells” and the morphology and texture of their esterase‐containing processes were remarkably similar to the morphology and distribution of the material that stained with AF. It may be that the “high‐esterase cells” contain AF‐positive material. The “high‐esterase cells” hydrolyzed both alpha‐naphthyl acetate and alpha‐naphthyl butyrate. The pinealocytes hydrolyzed only alpha‐naphthyl acetate. The “high‐esterase cells” appear to form a distinct class of cells within the superficial pineal gland. They are tentatively identified as a type of glial cell.
Light and electron microscopic observations on noradrenergic nerves and striated muscle cells of the guinea pig urethra
Authors: Dixon J. S. , Gosling J. A.
Published: February 2005

Neurohistochemical and electron microscopic techniques have been used to determine the arragement and distribution of noradrenergic nerves and striated muscle in the wall of the guinea pig urethra Fluorescent, catecholamine ‐ containing nerves were observed among striated muscle cells only in the junctional zone between an inner layer of smooth muscle and an outer layer of striated cells. In this region considerable intermixing of the two types of muscle cell occurred Electron microscopy has shown that noradrenergic terminal regions containing characteristic small dense‐cored vesicles were invariable associated with smooth muscle cells; such nerves were never observed forming neuroeffector relationships with striated cells. These findings indicate that noradrenergic ‘sympathetic’ fibers are not directly involved in the functional control of urethral striated muscle.
Observations on the morphological heterogeneity of WI‐38 cells
Authors: Wolosewick John J. , Porter Keith R.
Published: February 2005

WI‐38 cells of intermediate and late‐passage cultures were examined by light microscopy, scanning, conventional transmission and high voltage electron microscopy for evidence of heterogeneity among the cells within a single culture. Two morphologically distinct cell sizes and shapes were noted in all passages, (1) a typical fibroblastic type, and (2) a much larger, non‐fusiform type. The larger cells generally had a nucleus that was positioned to one side of the bulk of the cytoplasm. The smaller was consistently fusiform with a centrally placed nucleus. The surfaces of intermediate‐passage cells were uniform in showing small microvilli and cortical pits but were otherwise smooth and without distinctive features. The late‐passage cells, on the other hand, were consistent in showing numerous blebs and marginal ruffling. The internal structure of these cells in all passages studied was complicated by many age‐related changes. The observations indicate that there is in WI‐38 cells a high degree of intraculture heterogeneity. An awareness of this is important in studies which characterize the biochemical properties of this cell strain.
Age‐related variations in hepatic regeneration and erythropoietin production in the rat
Authors: Naughton Brian A. , Piliero Joseph A. , Kruger Richard E. , Birnbach David J. , Roy Martin , Piliero Sam J. , Gordon Albert S.
Published: February 2005

Erythropoietin (Ep) is produced mainly by the liver and spleen during fetal and neonatal periods and by the kidney during adolescent and adult life. The liver is also an important extrarenal producer of Ep in the hypoxic, anephric adult animal. Subtotal hepatectomy results in a substantial elevation in serum Ep levels at 30‐72 hours after hepatectomy in rats subsequently nephrectomized and rendered hypoxic. Ep production is related to the mass of regenerating liver with peak Ep production occurring during times of greatest tissue proliferation. Regenerative and erythropoietic responses to hepatectomy decline with advancing age. Rats undergoing repeated hepatectomies do not recover full liver mass but the initial rate of regeneration increases following each successive hepatectomy. Ep levels decline in anephric hypoxic rats undergoing multiple hepatectomies when compared to sham‐operated controls.
Specializations of the ependyma in the third ventricle of the developing hamster
Authors: Hannah R. S. , Geber W.
Published: February 2005

Ependymal cells in the region of the hypothalamic sulcus, hypothalamus, infundibular recess and supraoptic recess exhibit large apical protrusions between day 12 and day 14 post coitus. The ependyma was examined using light microscopy and transmission and scanning electron microscopy. The protrusions contain ribosomes and cytoplasmic matrix. Occasionally other cytoplasmic organelles were found within the protrusions. The protrusions range in shape from a rounded elevation of the apical surface of the ependymal cell to spherical bodies attached to cell surface by a slender stalk. The unique transitory specialization of the ependyma may represent either a neurosecretory or mechanical folding mechanism.
Correlative fluorescence‐immunocytochemical technique for the localization of monoamines and neurophysin (NP)
Authors: McNeill Thomas H. , Hoffman Donald L. , Kozlowski Gerald P.
Published: February 2005

A correlative fluorescence‐immnucytochemical technique for the localization of monoamines and neurophysin on sections of freezedried tissues is described. An extensive network of monoamine‐containing perikarya and terminals was found throughout the hypothalamus and median eminence. Immunocytochemical localization of antisera for neurophysin was found in the supraoptic and paraventricular nuclei of the hypothalamus and in both the zona interna and zona externa of the median eminence. This correlative demonstration of both catecholamines and neuropeptides within the same tissue provides a new approach to the study of neurotransmitters and neurohormones and their role in the regulation of the peripheral endocrine system.
Adult monkey coronoid process after resection of trigeminal nerve motor root
Authors: Sarnat Bernard G. , Feigenbaum Joel A. , Krogman Wilton M.
Published: February 2005

A smaller or absent coronoid process has been reported, by some investigators but not by others, in growing animals following resection of the temporalis muscle. The trauma of resection, altered function, hemorrhage, scar tissue, and changes in vascularity may have influenced the results. The purpose of this experiment was to observe in adult Macaca mulatta the fully grown coronoid process after decreasing or eliminating neurofunctional activity of the temporalis muscle unilaterally without the trauma of local resection. In two males and three females the motor root of the trigeminal nerve which innervates the temporalis muscle was resected intracranially. In three control animals of both sexes the same surgical procedure was performed except for resection of the nerve. At postmortem, one year later, the temporalis muscle mass was atrophic on the resected side. There were no significant morphological differences, however, between the right and left sides of the mandible, including the coronoid process, regardless of which motor root of the fifth nerve had been resected, which side had been sham‐operated, or sex. An extensive deposit of calculus on the buccal surfaces of the teeth on the operated nerve side was a consistent, conspicuous finding.
A morphometric examination of type II alveolar epithelial cells in normal and isolated‐perfused dog lungs
Authors: DeFouw David O. , Berendsen Peter B.
Published: February 2005

The volume densities of type II alveolar cell cytoplasmic organelles and alveolar surface densities were estimated by established stereologic procedures. The morphometric measurements were obtained from normal dog lungs (in situ) and isolated dog lungs perfused for 30‐minute, 1‐hour, and 2‐hour periods. The type II cell lamellar body volume densities and the alveolar surface densities progressively decreased as the times of perfusion were increased. The volume densities of the granular and agranular endoplasmic reticulum progressively increased during the periods of perfusion. These morphometric parameters from lungs in situ and isolated lungs suggest that changes occur in pulmonary surfactant synthesis and activity during perfusion. It is further postulated that progressive increases in the rates of surfactant removal and/or inactivation during perfusion may contribute to spontaneous edema in lungs isolated for periods exceeding two hours. The morphologic and physiologic integrity of isolated perfused lung preparations, widely used as models of lungs in vivo, in situ requires further evaluation.
Age related differences in binding of Concanavalin a to plasma membranes of isolated neurons
Authors: Bennett Kimberly D. , Bondareff William
Published: February 2005

Neurons isolated from the lateral vestibular nucleus of young adult and senescent Fischer‐344 rats were incubated with fluorescamine‐labelled Concanavalin A (fl‐Con A) alone, or following incubation in trypsin or Vibrio cholerae neuraminidase. They were then observed and photographed. Microdensitometric analysis of fluorescence micrographs showed that senescent rat neurons were significantly more fluorescent than those from young adult rats. Additionally, either patches or caps of fl‐Con A were seen on the surface of neurons from senescent rats, while most young adult rat neurons bound fl‐Con A uniformly.

Pretreatment with trypsin or neuraminidase had no effect on the amount of fluorescence on the surface of senescent rat neurons, and only a slight effect on the surface distribution. Trypsin and neuraminidase treatments caused a significant increase in fluorescence on the neuronal plasma membranes of young adult rats and a rearrangement of the binding pattern in the majority of neurons observed.
A study by light and scanning electron microscopy of the lining epithelium of the guinea pig bladder following artificial ulceration
Authors: Wong Y. C. , Martin B. F.
Published: February 2005

Following artificial ulceration of the guinea pig bladder epithelium, study by light microscopy showed that mitotic activity occurs within 24 hours in the basal layer of the remaining epithelium, which leads to thickening, disorganization and cell shedding. At the ulcer margin, the epithelium forms a rolled edge, from the extremity of which a two‐layered sheet of flat cells grows over the edematous ulcer bed, and the ulcer site is protected during dilation of the bladder by localized muscle spasm. Healing is effected within about one week, as the mitotic activity declines. Organization of the new epithelium commences at the periphery and the cells acquire glycogen and alkaline phosphatase. Study by SEM, which included normal bladders, confirmed that new epithelium spreads from a rolled epithelial edge, and also showed that cells undergoing rejection have globular profiles with surface microvilli. The immature epithelial cells are markedly distorted from mutual pressure during migration and their surfaces show only short microvilli. Ulcers heal after four to seven days, depending on size, and the new cells rapidly assume the pentagonal and hexagonal outlines and the reticular pattern of surface ridges, characteristic of mature surface cells. The ridges apparently develop by fusion of rows of microvilli. By the tenth day it is difficult to identify the original ulcer site.
Ultrastructural characterization of the manchette microtubules in the seminiferous epithelium of the mouse
Authors: Wolosewick John J. , Bryan John H. D.
Published: February 2005

In the mouse seminiferous epithelium four sites of formed microtubules (MTS) are axonemes and manchettes of spermatids, Sertoli‐cell cytoplasm, and spindles of dividing cells. Various experimental treatments indicate that the manchette MTS are different from other formed MTS. Fixation in 1% osmium tetroxide yields good preservation of axonemal MTS, varying degrees of preservation of manchette MTS, but no preservation of spindle or Sertoli‐cell MTS. Cell‐suspension, and intact‐tubule cultures subjected to 0–4°C or 50°C exhibit a breakdown of spindle and Sertoli‐cell MTS while manchette and axonemal MTS remain intact. Cell suspensions exposed to Colcemid or colchicine show no MTS in Sertoli and dividing cells; axonemal MTS are unaffected while in the manchette there is an increase in cross‐bridging between MTS. Cell suspensions treated for 120 minutes with vinblastine sulfate do not show MTS in the Sertoli cells, but crystals presumed to be microtubule protein are present after 15 minutes of exposure. Spindle MTS are dismantled but vinblastine‐induced crystals are not present even after 120 minutes of exposure. The manchette MTS are dismantled by vinblastine in a proximal direction from their distal limits. This is accompanied by the formation of crystals of microtubule protein in the spermatid cytoplasm, while axonemal MTS are unaffected. Vinblastine and Colcemid used in combination cause the disruption of Sertoli‐cell MTS after 15 minutes, spindle MTS after 30 minutes and formation of crystals after 60 minutes of exposure. The manchette MTS are disassembled, the pattern is disrupted and increased numbers of cross‐bridges are seen. These findings indicate that the manchette MTS might be intermediate‐type microtubules since they exhibit the reactions of both cytoplasmic and flagellar‐type MTS.
Variations in intrafusal fiber size within histochemically identified types of intrafusal fibers in the pigeon
Authors: Maier Alfred
Published: February 2005

The myofibrillar adenosine triphosphatase reaction with acid preincubation allowed the identification of three types of intrafusal fibers in pigeon flexor carpi ulnaris muscle spindles. Measurements of cross‐sectional areas at the polar region showed much overlap in fiber size among populations of each type.
Electron microscopy of the connective tissues between longitudinal and circular muscle of small intestine of cat
Authors: Taylor A. B. , Kreulen David , Prosser C. L.
Published: February 2005

Electrotonic spread of applied potentials was observed between longitudinal and circular muscle layers of the small intestine with no rectification. Nexal junctions were demonstrated between muscle fibers of each layer. Connective tissue cells bridged between the two muscle layers. These showed structural characteristics of fibrocytes and of interstitial cells. Some nexuses were seen between connective tissue cells and between these cells and muscle fibers of each layer but in most junctions the membranes were 10–18 nm apart. Since connective tissue can serve for electrical conduction between cultured heart cells and since electrical properties of intestinal muscle permit transmission with low degrees of coupling, it is suggested that interstitial cells and fibrocytes may electrically couple longitudinal and circular muscle layers of cat intestine.
Relative volume of sertoli cells in monkey seminiferous epithelium: A stereological analysis
Authors: Cavicchia Juan Carlos , Dym Martin
Published: February 2005

Techniques of quantitative stereology have been utilized to determine the relative volume occupied by the Sertoli cells and germ cells in two particular stages (I and VII) of the cycle of the seminiferous epithelium. Sertoli cell volume ranged from 24% in stage I of the cycle to 32% in stage VII. Early germ cells occupied 3.4% in stage I (spermatogonia) and 8.7% in stage VII (spermatogonia and preleptotene spermatocytes). Pachytene spermatocytes occupied 15% (stage I) and 24% (stage VII) of the total volume of the seminiferous epithelium. In stage I the two generations of spermatids comprised 58% of the total epithelium by volume, whereas in stage VII, after spermiation, the acrosome phase spermatids occupied 35% of the total seminiferous epithelial volume.
A light and scanning electron microscopic study of the basilar papilla in the salamander, Ambystoma tigrinum
Authors: White James S.
Published: February 2005

The basilar papilla and basilar recess of Ambystoma tigrinum have been investigated by light and scanning electron microscopy. The recess is an evagination of the lagena, and is invested externally by dense periotic connective tissue, except over a thin area of one wall abutting against a periotic diverticulum communicating with the periotic sac. The surface and histological features of the non‐sensory lining epithelium are described. The basilar papilla occupies both slopes of an elevation adjacent to the thin wall of the recess, and consists of 40 to 80 sensory cells interposed between sustentacular cells. The sensory cells are innervated by 30 to 40 nerve fibers exhibiting two ranges of diameter, and they are capped by typical ciliary bundles that are taller at the center of the receptor than at its periphery. Bundles in the proximal and distal halves of the papilla are polarized, respectively, toward the saccule and toward the thin wall in contact with the periotic diverticulum; this divergent pattern of polarization has not been reported previously in the basilar papilla of other vertebrates. A tectorial body overlies only the bundles in the distal half of the receptor, and is attached to both the neuroepithelium and the opposite wall of the recess. Functional considerations are discussed, and comparisons are made with conditions reported in frogs and toads. The findings suggest that the basilar papilla and recess in caudate and anuran amphibians arose from common precursors and probably function in a similar manner.
Effect of vitamin A and methylprednisolone on canine prostate in organ culture
Authors: Fischer Theodore V. , Kahn Raymond H. , Burkel William E. , Vinter David W. , Herwig Karl R.
Published: February 2005

Organ explants from the canine prostate with and without methylprednisolone pretreatment were cultivated for ten days in Trowell's T‐8 medium or medium supplemented with testosterone and/or vitamin A. Upon termination of the experiments, explants were fixed and examined histologically. All glands from the most central section of each explant were graded according to epithelial type, and from these grades the proportion of acini with maintained columnar cells was calculated for each explant. Stromal cellular maintenance was also estimated. While a small proportion of explants from the vitamin‐treated and methylprednisolone‐pretreated groups showed epithelial maintenance, a combination of these treatments significantly increased such maintenance. Stromal maintenance was enhanced with methylprednisolone pretreatment but not by vitamin A. These results are in accord with the hypothesis that methylprednisolone acts to stabilize the lysosomal membrane, thus protecting tissue against the effects of ischemic shock. In protected explants vitamin A is able to maintain a columnar glandular epithelium. In a subsequent experiment a series of linoleic acid dosages was tested in the presence or absence of vitamin A. In neither case was this fatty acid of value in improving epithelial or stromal maintenance.
Synthesis and migration of glycoproteins in cells of the rat thymus, as shown by radioautography after 3H‐fucose injection
Authors: Bennett Gary
Published: February 2005

Young male rats received a single intravenous injection of 3H‐fucose and were killed after various time‐intervals. Light‐ and electron‐microscopic radioautographic studies of the thymus in animals killed shortly after injection showed that all of the different cell types present incorporated 3H‐fucose label. The heaviest uptake occurred in macrophages and in hypertrophic epithelial cells located near the cortico‐medullary border. Somewhat lighter incorporation was observed in medullary and cortical stellate epithelial cells and in cells designated as special cells, while the lightest reaction appeared over lymphocytes.

In all cells the label was localized initially to the Golgi apparatus, where, presumably, it was incorporated into glycoproteins. With time, some of the labeled putative glycoproteins in all cell types migrated to the plasma membrane. In macrophages, much of the label migrated to lysosomal bodies, while in the special cells the label migrated to dense bodies which may also be of lysosomal nature. In stellate and hypertrophic epithelial cells much of the label migrated to characteristic vacuoles. The possible relationship between the observed glycoprotein synthesis in these cells and hormone production is discussed.
The distribution and mobility of anionic sites on the brush border of intestinal absorptive cells
Authors: Jersild Ralph A. , Crawford R. W.
Published: February 2005

The distribution and behavior of anionic sites on the micro‐villous surface of rat jejunal absorptive cells were studied using the multivalent ligand polycationic ferritin (PCF) as a visual probe. Segments were incubated in PCF either before or after glutaraldehyde fixation. The results indicated that the anionic sites can be divided into three groups based on their interaction with PCF: (1) Some sites along the length of the microvilli are accessible for binding PCF in living, unfixed cells. These sites are capable of translational mobility at the membrane surface and can be induced to cluster into discrete patches by PCF. Under appropriate conditions, they may be taken into the cell by endocytosis. Their redistribution is prevented by prefixation, and slowed by incubation at temperatures of 0°C or below. (2) Some sites along the length of the microvilli are inaccessible to PCF without prior fixation. These sites may provide uniform coverage or may be preferentially localized to the distal microvillus. (3) Some sites restricted to the microvillous tips are accessible to PCF without fixation, but are apparently immobile. Their high density on some tips forms a distinctive cap of ferritin particles. More anionic sites were found on the microvilli of the more mature cells of the upper villus. In addition, independent variation was observed in the number of sites in each of the three groups among neighboring cells, irrespective of villous position, suggestive of variations in the turnover of these sites.
Effects of steroids and gonadotropins on follicular development in the hypophysectomized hamster
Authors: Chiras Daniel D. , Greenwald Gilbert S.
Published: February 2005

To determine the rate of follicular development in long‐term hypophysectomized (H) hamsters, single IP injections of 3H‐thymidine were given six days after H and autoradiographs were prepared from animals killed on days 6–15. Only follicles in stages 1 (2–3 layers of granulosa cells), 2 (4–5 layers) and 3 (6–7 layers) were present and there were fewer follicles than in intact, cyclic hamsters. The entire population of follicles in stages 1 and 2 was replaced every five to six days in hypophysectomized hamsters, whereas in cyclic hamsters, complete turnover takes eight days (Chiras and Greenwald, '77).

Other groups of H hamsters were treated on days 4–6 with either estradiol benzoate (EB — 10 μg), progesterone (P — 1 mg) or EB and P and then given 3H‐thymidine at 0900 hours of day 6 and killed one hour later. Steroid treatment affected early stages of follicular development: EB stimulated growth of these follicles; P alone had little effect; given with EB, P acted as an antagonist.

Other H hamsters were treated with FSH (100 μg), LH (10 μg), FSH + LH, PMS (30 IU) or saline vehicle at 0900 hours six days post‐hypophysectomy. They were injected with 3H‐thymidine at 2100 hours on day 6 and killed one hour later. LH‐ and saline‐treated animals had approximately the same number of follicles; however, there were no stage‐3 follicles in the LH‐treated group and the percentage of labelled follicles in stages 1 and 2 was significantly lower after LH treatment. FSH enhanced follicular development and thymidine uptake. Twice as many stage‐3 follicles were seen in FSH‐treated animals as controls; stage‐4 follicles (>8 layers of granulosa cells) were also encountered after FSH treatment. Labelling Index (LI) and Intensity (L. Int.) for the FSH‐treated group were the highest of all treatments. LH antagonized some of the effects of FSH. PMS resulted in follicular growth similar to that achieved by FSH; however, PMS markedly depressed LI and L. Int., which was probably due to the LH‐like component of PMS. These results demonstrate that the gonadotropins affect the development of small follicles. FSH stimulates growth; LH depresses follicular growth when administered alone and antagonizes some of the effects of FSH.

Hamsters pretreated with EB or P on days 4–6 and then given a single, subcutaneous (SC) injection of FSH at 0900 hours on day 6, were treated with 3H‐thymidine at 2100 hours on day 6 to assess the interaction of steroids and FSH. EB pretreatment caused the development of stage‐5 follicles (early antral follicles) but did not increase thymidine uptake (measured by LI and L. Int.) in the small follicles above that attained by FSH alone. P pretreatment diminished thymidine uptake in small follicles, but did not reduce their number.

These results demonstrate that in the hamster the population of small follicles, i.e., the often misnamed “pituitary‐independent” follicles, can be influenced quantitatively and qualitatively by steroids and gonadotropins.
Dendritic atrophy in the dentate gyrus of the senescent rat
Authors: Geinisman Yuri , Bondareff William , Dodge John T.
Published: February 2005

Quantitative electron microscopic analysis of the supragranular zone of the dentate gyrus molecular layer has shown that the number, volume fraction and surface area of dendritic shaft profiles are significantly decreased in senescent rats, relative to young adults. These modifications of dendritic morphology, which are not associated with age‐related changes in dimensions of the molecular layer or in numbers of granule cells, may result from a decrease in the number and/or length of dendrites. In either case, the decreases in the number, volume fraction and surface area of dendritic shaft profiles found in the dentate gyrus of senescent rats signify an age‐related atrophy of dendrites. Comparison of changes in the number and volume fraction of dendritic shaft profiles has demonstrated that age‐related dendritic atrophy involves predominantly smaller dendritic branches.
Synthesis and secretion of glycoprotein in rat bulbo‐urethral (Cowper's) glands. II. Modes of mucus secretion after stimulation by copulation
Authors: Geuze J. J. , Slot J. W.
Published: February 2005

Copulation forced the mucous cells of rat bulbo‐urethral (Cowper's) glands to accelerate their secretion. Determination of macromolecularly‐bound hexose as a measure for the mucous contents of the glands and light and electron microscopic observations showed that the glands lost their mucus within four hours after the start of copulation. Secretion of the mucous granules occurred in an exocytotic fashion. This led to the formation of extensive secretory canaliculi extending to the cell bases. Successive mutual coalescing of the mucous granules formed intracellular secretion channels running from the secretory cell surfaces deeply into the cells.

The vast reduction of cellular volume by loss of the numerous secretory granules and the sudden addition of large amounts of granule membrane to the cell membrane caused a considerable enlargement of the cell surface. The superfluous cell membrane was stored temporarily in tufts of long microvilli. The appearance of endocytotic structures and lysosomes was interpreted as indicative of internalization and breakdown of cell membrane. Between four and six hours after copulation cytoplasmic volume and size of RER and Golgi complex increased considerably, concurrently with increasing glycoprotein synthesis (Geuze and Slot, '76). During repopulation of the cells with mucous granules, luminal vesicles appeared close to the cell membrane between exocytotic pits. We suggest that the luminal vesicles originate by pinching off from microvilli and apical rims of cytoplasm overlying the mucous granules. Refilling of the glands was slow and took more than one week.
Dispersion of cisternae of rough endoplasmic reticulum in aging CNS neurons: A strictly linear trend
Authors: Hinds James W. , McNelly Nancy A.
Published: February 2005

Dispersion of cisternae of rough endoplasmic reticulum (RER) in aging rats has been determined quantitatively for mitral cells of the olfactory bulb and Purkinje cells of the cerebellum using a recently published morphometric technique (Cruz Orive, '76). In both cell types dispersion of cisternae occurred throughout the period studied and in a linear fashion. The observed RER dispersion cannot be attributed to a decrease in the total amount of RER, since the total amount of RER was constant in Purkinje cells and increased in mitral cells during the ages studied.
Structural differences of pale and strongly stained motor end‐plates of the rat diaphragm
Authors: Wong Y. C. , Ip M. C.
Published: February 2005

According to the staining intensities for AChE, the motor end‐plates of the rat diaphragm can be classified into strong (S) and pale (P) types. About 34% of the total end‐plates of the rat diaphragm are of S type and 50% of P type. The P end‐plates differ from S end‐plates in two aspects. First, the secondary subneural clefts of the S end‐plates are well developed. They are numerous, long, closely packed and often branched. On the other hand, the secondary subneural clefts of the P end‐plates are short, sparse and usually unbranched. Secondly, there seems to be a variation in AChE activity in the P end‐plates. Focal negative AChE areas are found in the subneural apparatus of some P end‐plates. It is concluded that the less well developed secondary subneural clefts and focal areas of negative AChE activity contribute to the paler staining of the P end‐plates.
Non‐random spatial distribution of mitoses in proliferating rat uterine epithelium
Authors: Purnell Dallas M.
Published: February 2005

A non‐random spatial distribution of mitoses in proliferating rat endometrium was found by means of a quantitative microscopic technique. Nulliparous Lewis/Mai rats, 60–90 days of age, were given an intraperitoneal injection of colchicine (1 mg/kg) five hours prior to death, to arrest mitosis at metaphase. The middle one‐third of the right uterine horn was removed and fixed in Bouin's fixative for 24 hours. Several 5‐μm microtome sections were cut from dehydrated, paraffin‐embedded uterine tissue from each rat and stained with hematoxylin and eosin. Microtome sections of uterine horn which showed high endometrial mitotic activity, i.e., those obtained from rats killed in the metestrus phase of the estrous cycle, were selected for microscopic analysis. Using a binocular microscope equipped with an eye‐piece graticle, maps of uterine horn cross‐sections (3 non‐adjacent microtome sections/rat) showing the spatial distribution of mitoses along the surface of the uterine lumen were prepared. Data collected from the mitotic maps were: (a) the frequency of graticle squares containing mitoses and bounded on either side by graticle squares without mitoses; (b) the frequency of sequences of two or more adjacent graticle squares with mitoses; and (c) the frequency distribution of mitotically‐inactive intervals (number of graticle squares) between graticle squares enclosing mitoses. The observed frequency distribution of adjacent graticle squares with mitoses and the observed frequency distribution of spacing intervals between graticle squares with mitoses were examined for non‐randomness by generating from these data the Poisson frequency distributions expected assuming a random distribution. Goodness of fit between observed and expected distributions was tested using Chi‐square analysis.

These analyses revealed, in each case, a significant deviation from randomness. Our data support a non‐random spatial distribution of mitoses in uterine epithelium and indicate that mitotic activity in rat endometrium occurs in localized spatial regions separated by relatively long regions of mitotically inactive endometrium.

Possible mechanisms of production of a non‐random tissue distribution of mitoses are discussed.
Cyclic changes in ciliation of the oviductal epithelium in the pig‐tailed macaque (Macaca nemestrina)
Authors: Rumery R. E. , Gaddum‐Rosse P. , Blandau R. J. , Odor D. L.
Published: February 2005

Many of the cilia in the oviducts of rhesus monkeys are formed in the follicular phase of the menstrual cycle, and lost in the subsequent luteal phase (Brenner, 1969a). This striking phenomenon has rarely been observed in other species, and its occurrence in human oviducts is a point of dispute. This study was designed to determine whether cyclic shedding and renewal of oviductal cilia occur in a primate species other than the rhesus monkey and to reveal the surface characteristics of the oviductal mucosa in a subhuman primate. Oviducts were removed from Macaca nemestrina females at three specific times during the menstrual cycle and examined by scanning electron microscopy. The fimbriae appeared to be extensively ciliated at midcycle but only sparsely ciliated in the early follicular and late luteal phases. Early in the cycle, large numbers of cells were seen in the process of ciliogenesis, but in the late luteal phase there were signs of ciliary degeneration and shedding. The ampullar epithelium showed similar though less dramatic changes, and the isthmus little change. Long‐term ovariectomy caused almost complete deciliation of the fimbrial and ampullar epithelium, but treatment of ovariectomized animals with estrogen for only a few days restored the epithelium to normal. Despite the high degree of variability in the mucosa, it was clear that the oviducts of M. nemestrina, like those of the rhesus monkey, undergo cyclic ciliogenesis and deciliation. The surface features of the oviductal lining in M. nemestrina are described here for the first time.
Non‐primary afferents to the principal cells of the rostral anteroventral cochlear nucleus of the guinea pig
Authors: Schwartz A. M. , Gulley R. L.
Published: February 2005

The non‐primary input to the soma of the principal cells of the rostral anteroventral cochlear nucleus (AVCN) of the guinea pig was defined by correlating data from freeze‐fractured and thin‐sectioned specimens. The principal cells receive three types of non‐primary terminals in addition to a single end bulb from the ascending branch of the auditory nerve. The first, the O‐boutons are irregularly shaped, medium‐sized boutons, containing oval synaptic vesicles. These cover about 13% of the soma and each makes from one to three crescent‐shaped axosomatic junctions. Paramembranous dense material is distributed symmetrically between the pre‐ and postsynaptic junctional membranes. The second, the F‐bouton, is a small, ovate bouton which occurs either singly or in small clusters and covers about 5% of the soma. This bouton, containing flattened synaptic vesicles, has a single, oval synaptic junction lined by thin, paramembranous densities distributed symmetrically between the pre‐and postsynaptic membranes. The third, the SR‐bouton, is a medium‐sized bouton containing small, round synaptic vesicles. These boutons cover about 4% of the soma, but more frequently contact dendrites in the neuropil. The junctional region of the bouton is poorly defined. Small tufts of dense material symmetrically line the cytoplasmic surfaces of the pre‐ and postsynaptic membranes along scattered, narrow undulations of the apposition. In freeze‐fracture replicas, several narrow troughs on the cytoplasmic leaflet frequently have a higher density of large intramembranous particles than adjacent membrane and may represent a diffusely organized active zone. No specializations are found on either leaflet of the postsynaptic plasmalemma opposite the non‐primary boutons. Correlation of the measurements from thin‐sectioned and freeze‐fractured material suggests that the oval, flattened, and small round vesiclecontaining boutons occur on the somata of the principal cells in a ratio of 6:3:1.