bluuebunny/crossref_metadata_2025 huggingface dataset:
Coronary artery distribution in bonnet monkeys (Macaca radiata)
Authors: Buss Daryl D. , Hyde Dallas M. , Poulos Paul W.
Published: February 2005

Full use of nonhuman primates as a model for coronary vascular disease has been hampered by several factors, including the limited availability of detailed coronary anatomic data. This study was undertaken to identify the gross coronary arterial anatomy of the Bonnet monkey (Macaca radiata). The hearts of sixteen adult male Bonnet monkeys were subjected to postmortem coronary angiography and gross morphological examination. The main left coronary artery divided into the left anterior descending coronary artery (LAD) and the left circumflex coronary artery (LCA). The posterior descending coronary artery (PDCA) arose from the LCA in 31% of the cases and from the right coronary artery (RCA) in 56% of the hearts. Hearts from two animals (13%) had paired arteries, arising from the LCA and RCA, located in the posterior interventricular groove. The arterial supply to the sinoatrial node originated from the LCA in 69% of the animals and from the RCA in the remainder. The atrioventricular node was supplied by a branch of the RCA in 69% of the animals and from the LCA in the remainder. The coronary anatomy of the bonnet monkey resembles that of man more closely than does the dog in terms of origin of the PDCA, supply of the sinoatrial and atrioventricular nodes, and perfusion of the interventricular septum. The Bonnet monkey may therefore be a useful model for certain specific pathophysiological studies on the coronary circulation.
Cellular distribution within the rat adenohypophysis: A morphometric study
Authors: Poole Max C. , Kornegay W. Daniel
Published: February 2005

A morphometric analysis of the cell types within the adenohypophysis of the female rat was conducted with an emphasis on regional variations. Type I and type II gonadotropes and corticotropes had the largest volumes, mammotropes and somatotropes were of medium size, and thyrotropes and chromophobes were the smallest cells. There was no regional variation in the volumes of the respective cell types.

Somatotropes and mammotropes were most numerous, followed by the gonadotropes, chromophobes, corticotropes, and thyrotropes. There was no significant regional localization of the somatotropes, mammotropes, corticotropes, and thyrotropes. Gonadotropes were best defined as two populations with type I cells being localized in the central regions and type II cells being distributed throughout the gland. Chromophobes were the only cells with a significant distribution in the anterior regions and were most numerous in the anterior peripheral regions. These fine‐structural morphometric findings are discussed in relation to other studies of the adenohypophysis that utilize immunocytochemistry.
Immunohistochemical study of C cell follicles in dog thyroid glands
Authors: Kameda Yoko
Published: February 2005

In dog thyroid glands there are C cell follicles which are lined solely by C cells and which accumulate a colloidlike substance in the luminal cavities. In order to clarify the properties of the colloidlike substance secreted by C cells, the C cell follicles were stained with PAS reaction and immunoperoxidase method using anticalcitonin, anti‐C‐thyroglobulin, and anti‐19S‐thyroglobulin antisera, respectively. The colloidlike substance was PAS positive and revealed the strong immunoreaction for C‐thyroglobulin but a faint reaction for calcitonin. It was nonreactive with anti‐19‐thyroglobulin antiserum. These results confirm that C cells synthesize the glycoprotein immunoreactive to anti‐C‐thyroglobulin antiserum in addition to calcitonin and can store it in the follicular lumens.
Anionic sites on the surface of frog ependymal astrocytes and mouse ependymal cells
Authors: Korte Gary E. , Rosenbluth Jack
Published: February 2005

The binding of colloidal iron hydroxide (CI) and ruthenium red (RR) to the plasma membrane of frog ependymal astrocytes was examined by electron microscopy. Positively charged CI and RR bind to the external surface of the plasma membrane of all parts of the ependymal astrocyte. Prior treatment with neuraminidase markedly reduces the number of bound CI particles, suggesting that the sialic acid of carbohydrates associated with the cell surface is responsible for much of the CI binding. Comparable observations were made on mouse ependymal cells. These findings indicate that an anionic, carbohydrate‐rich cell coat occurs on the plasma membrane of amphibian ependymal astrocytes and mammalian ependymal cells. This cell coat may be related to transport, barrier, or receptive functions of ependymal cells.
Histochemical localization of prostaglandin synthetase in human exocrine glands
Authors: Sirigu Paola , Cossu Margherita , Perra Maria Teresa
Published: February 2005

Prostaglandin synthetase activity is histochemically detected in the epithelial cells of the human prostate, seminal vesicle, and deferential ampulla. The addition of the specific inhibitor indomethacin to the incubating medium strongly reduces the staining reaction. The presence of exogenous substrate in the medium is not required for the reaction, since identical results are observed following incubation with and without arachidonic acid. The presence of the enzyme appears to be related to the secretion of prostaglandins into the seminal fluid, but there is a possibility that some prostaglandins influence the metabolism of the secreting cells themselves. The localization of prostaglandin synthetase in the ductal epithelia of human salivary glands is related to a possible regulatory role of the prostaglandins upon the reabsorptive activity of the ductal cells.
Histomorphometry and autoradiography of cultured fetal rat long bones
Authors: Nefussi Jean‐Raphael , Vignery Agnes , Puzas J. Edward , Baron Roland
Published: February 2005

The behavior of fetal rat long bones cultured in vitro according to Raisz's technique (1969) was studied by histomorphometry and autoradiography for a period of four days. The changes were recorded daily both on the trabecular and cortical bone by measuring the bone volume, the number of osteoclasts, and the number of nuclei per osteoclast. Radioactive calcium release was measured and compared to the changes in bone volume and in the number of osteoclasts. An autoradiographic study, using 3H‐proline and 3H‐thymidine in flash labeling in the medium and 3H‐thymidine in follow‐up labeling after one injection in vivo was performed to evaluate the bone formation, the cellular proliferation rate and cell differentiation. After four days in culture, an increase in total calcified bone volume was observed which correlatd with changes in the trabecular bone. No significant changes were recorded in the cortical bone. The results showed a good maintenance of the resorption and formation phenomena through an active process of cellular multiplication and differentiation. Undifferentiated cells were labeled in flash label and osteoblast, osteocyte and some osteoclast nuclei were labeled in follow‐up studies.
Intralitter variation of neonatal rat lung morphology following prenatal maternal hypervitaminosis A
Authors: Newman L. M. , Johnson E. M. , Cadogan A. S. A.
Published: February 2005

Prenatal exposure to excess vitamin A (160,000 USP units/day) from days 15 through 19 of gestation results in altered lung morphology, characterized by thickened septal walls and/or large areas of atelectasis and an associated high neonatal mortality. Marked variability in both morphological and physiological expression from this prenatal insult is commonly seen between litters and littermates, making analyses difficult. The present study documents morphological intralitter variation observed in vitamin A‐exposed 2‐day‐old rats as compared to controls. Representative midhilar coronal histological sections of each lung were examined by two methods and the results compared. The first method, although less sensitive, demonstrated that five out of eight experimental rat lungs had a significantly greater percentage of tissue to airway space as compared with undisturbed controls (>43%). The second method, using several morphological criteria and a grid system to score parenchyma into classifications based on the degree of morphological variation and projected functional capability, clearly found significantly increased percentages of poor or nonfunctional lung tissue (P < 0.01) in seven out of eight pups exposed to excess vitamin A. This method of ranking the severity of adverse effects on tissue morphology allowed identification of drug‐affected newborn and provided a means to quantify the alterations. Such a means for identifying affected individuals from littermates is essential to research methodologies for detecting substances which, when administered during fetal life, produce decrements of postnatal function but no gross structural abnormalities.
Somatostatin immunoreactive C cells in thyroid glands from various mammalia species
Authors: Kameda Yoko , Oyama Hideki , Endoh Masahiko , Horino Masaharu
Published: February 2005

The relative distribution of somatostatin‐ and calcitonin‐containing cells in thyroid glands from various mammalian species was investigated by immunoperoxidase staining, and the concentration of immunoreactive somatostatin by radioimmunoassay. In the thyroid glands of guinea pigs and rabbits, most of the calcitonin cells were also immunoreactive to the somatostatin antiserum, and high concentration of immunoreactive somatostatin was obtained. On the other hand, in the thyroids of other animal species—rats, dogs, pigs, cows, goats, cats, monkeys, mice, and hamsters—only a few C cells revealed the immunoreaction for somatostatin, and the concentration of somatostatin was low. In all animal species studied, the somatostatin was present in the same cells that contain calcitonin, though in guinea pigs and rats there were some C cells containing a large number of reaction products for somatostatin but very few for calcitonin. Thus, it was concluded that there was a considerable variation in somatostatin immunoreactivity of thyroid C cells from species to species.
A description of the times of appearance and regression of marginal lingual papillae in human fetuses and newborns
Authors: Yamasaki Fusao , Takahashi Kyozo
Published: February 2005

Papillae, located along the anterolateral margin of the human tongue, were observed in fetal and newborn stages. The papillae appeared in the prenatal period and attained maximum development in the newborn. They had almost disappeared by the time of weaning. Although morphologically, the papillae may be considered to be a form of the filiform papillae, they differed from the filiform papillae in that they were temporary, localized at the anterolateral margin of the tongue, and larger in size. These papillae are homologous with those in certain land mammals and toothed whales, and may assist in sucking. Our findings on the times of appearance and regression of marginal papillae support this notion.
Carbonic anhydrase histochemistry in rabbit and mouse kidneys
Authors: Dobyan Dennis C. , Magill Linda S. , Friedman Peter A. , Hebert Steven C. , Bulger Ruth Ellen
Published: February 2005

The presence of carbonic anhydrase activity in rabbit and mouse kidneys was examined using a histochemical procedure with plastic embedded sections stained by the modified version of the cobalt‐phosphate method (Hansson, 1967, 1968; Ridderstrale, 1976). Proximal convoluted tubules (S1 and S2 segments) in both species were strongly positive for carbonic anhydrase activity on the membranes of the luminal, lateral, and basal surfaces. The apical cytoplasm beneath the brush border and the nuclei also stained positively for carbonic anhydrase. The S3 segment (pars recta) of the proximal tubule in the rabbit was positive on the luminal membrane, with somewhat less intensity seen on the lateral and basal surfaces. This segment in the mouse was completely negative. The first part of the thin limbs of long‐looped nephrons exhibited strong staining in the mouse. Faint luminal staining was present on descending thin limbs of short‐looped nephrons in the mouse. In the rabbit, both the medullary and cortical ascending thick segments of the limb of Henle were completely negative. In contrast, the medullary and cortical ascending thick limbs in the mouse kidney showed staining on all plasma membranes. The intercalated cells in the cortical and medullary portion of the collecting tubules stained positively for carbonic anhydrase in both species. The principal cells of the collecting duct in the cortex were negative in the rabbit and faintly positive in the mouse. The principal cells in the upper medullary collecting tubules in both species stained intensely along the luminal, lateral, and basal cell membranes. The papillary collecting ducts were largely negative in both the rabbit and the mouse. Some interstitial cells in the rabbit in the region of the papillary tip were strongly positive. We conclude that there is a marked difference in carbonic anhydrase activity within and between the renal tubular segments of the rabbit and the mouse. In addition, these distinct differences that exist between the two species correlated with known physiological roles in ion transport.
Ultrastructure of the human intervertebral disc: II. Cells of the nucleus pulposus
Authors: Trout Jerome J. , Buckwalter Joseph A. , Moore Kenneth C.
Published: February 2005

The cells of the intervertebral disc exist in a unique environment; not only are discs subject to large mechanical loads, they are the largest avascular structures in the body. To describe the ultrastructure and age changes in cells from human nucleus pulposus, we studied these cells in individuals ranging in age from the 26th week of fetal life to 91 years. Viable chondrocyte‐like cells existed in specimens from all ages. The presence of Golgi cisternae and well‐developed endoplasmic reticulum in these cells suggests that they are capable of producing and maintaining the extracellular matrix. Necrotic cells were also present in all samples, and many cells which appeared viable when examined by light microscopy proved to be necrotic when examined by electron microscopy. The percentage of necrotic cells increased with age from 2% or less in fetal specimens to over 50% in adults. In addition, with age, a distinct pericellular matrix or “nest,” consisting of collagen fibrils, fine filaments, dense particles, and banded structures, formed around most cells with no apparent preference for viable or necrotic cells. Nest formation and increasing density of the cell nests may reflect accumulation of cell products.
Ultrastructural features of the cell surfaces of uterine and trophoblastic epithelia during embryo attachment in the cow
Authors: Guillomot Michel , Guay Patrick
Published: February 2005

Ultrastructural features of the bovine uterine and trophoblastic epithelial cell surfaces were studied by scanning electron microscopy (SEM) at the time of attachment. Apical cytoplasmic protrusions were observed on the uterine cell surface from cyclic animals on days 12–16 during the luteal phase and disappeared thereafter. However, in pregnant animals, these cytoplasmic protrusions were observed until day 21 (attachment stage). These structures suggest that the uterine cells possess secretory and/or endocytotic properties.

Before the attachment stage the trophoblastic cell surface was uniformly covered by slender microvilli. At the beginning of conceptus attachment the microvilli disappeared and the trophoblastic cell surface became smooth. On areas of the conceptus facing uterine gland openings, papillae developed and filled the glandular lumen. These were interpreted to be a system by which the conceptus is immobilized on the uterine epithelium and/or a histotrophic mechanism for absorbing glandular secretory products.
Early pectoral fin development and morphogenesis of the apical ectodermal ridge in the killifish, Aphyosemion scheeli
Authors: Wood Andrew
Published: February 2005

Using scanning electron microscopy it has been found that in the killifish the distal epithelium of the pectoral fin bud forms a morphologically distinct apical ectodermal ridge along its entire distal margin. This ridge is a relatively more prominent feature than its counterpart in various tetrapod systems. At a later stage the ridge becomes folded internally and leongates distally marking the transformation of the ridge into a fin fold. By continued distal growth the fin fold develops into a semicircular swimming‐paddle. Collagenous rays or actinotrichia differentiate in a highly ordered arrangement close to the epithelial basement membrane within the space enclosed by this elongating fin fold and apparently support the early swimming‐paddle. During the ridge‐to‐fold transition the fin bud displays a dorsal deflection of approximately 45° and a caudalward rotation about the axis of the fin itself. This change in orientation results in close apposition of the developing fin structure to the flank.
Morphometric studies of the alveolar epithelium in dog lungs in vivo after increased rates of outward filtration
Authors: Defouw David O. , Chinard Francis P.
Published: February 2005

Increased pulmonary artery pressures and decreased albumin concentrations were established in dogs, in vivo, by circulatory overload and by plasmapheresis. Each change, occurring singly, would be expected to produce an increase in outward filtration rate. The ultrastructure of the alveolar epithelium after the production of this presumed increase in filtration was evaluated by established morphometric techniques. The extent of extravascular fluid accumulation was assessed by multiple indicator‐dilution studies and by light microscopic analysis. Previous studies from this laboratory (DeFouw and Berendsen, 1979; DeFouw, 1980) define increased alveolar surface densities, increased type I cell vesiculation, and depleted type II cell lamellar body contents after increased filtration had induced septal edema and alveolar flooding in isolated perfused dog lungs. In the present study septal edema and alveolar flooding were not detected. Nor were changes observed in either alveolar epithelial cells or in alveolar configurations. However, there was significant accumulation of extravascular fluid in cuffs around extraalveolar vessels. These results are consistent with the interpretation that the initial stage of cardiodynamic edema formation, namely, peri‐vascular cuffing, is not associated with structural aberrations of the alveoli or their lining epithelial cells, in vivo. Since such changes were detected previously in isolated lungs after development of the final stages of edema, namely, septal fluid accumulation and alveolar flooding, additional studies of septal edema and alveolar flooding in intact animals are necessary to establish functional correlates to ultrastructural aberrations in severely edematous lungs.
Scanning electron microscopy of mouse muscle microvasculature
Authors: Holley John A. , Fahim Mohamed A.
Published: February 2005

The surface morphology of the microvasculature from mouse skeletal muscle was studied by scanning electron microscopy. Cell surfaces were exposed by digesting away extracellular collagen and other matrix by a simple HCl treatment. Four distinct subdivisions of the microvasculature (arterioles, precapillary arterioles, capillaries, and venules) were identified based on marked differences in surface features. Arterioles of 20–10 μm diameter had a discontinuous, single layer of smooth muscle cells encircling the vessel. These smooth muscle cells had an uneven surface with shallow grooves and depressions that were often oriented parallel to the longitudinal cell body axis. The underlying arteriolar endothelial surface was also rough with long ridges separating shallow furrows that were oriented parallel to the vessel length. As the arteriolar size decreased, the perivascular cell were found further apart, they became smooth surfaced, and were oriented preferentially parallel to the vessel. The endothelium of the precapillary arterioles, as well as, capillaries and venules had smooth surfaces. Venules had a discontinuous layer of flat, smooth surfaced pericytes. Morphologically distinct groups of smooth muscle cells (i.e., precapillary sphincters) were not found. Although pericytes normally associated with capillaries and other vessels were often removed during tissue processing, most cells and their surface feature were generally well preserved.
Epidermal growth factor, renin, and protease in hormonally responsive duct cells of the mouse sublingual gland
Authors: Gresik Edward W. , Barka Tibor
Published: February 2005

In the striated ducts of the sublingual glands of normal adult male, but not female, Swiss‐Webster mice a few scattered cells have apical secretion granules. These sublingual duct cells resemble the granular convoluted tubule (GCT) cells of the submandibular glands of adult female mice, in that they are smaller than submandibular GCT cells of adult males, and contain fewer apical granules, and prominent basal striations. These cells stain immunocytochemically for epidermal growth factor (EGF), renin, and protease A. Such granular striated duct cells could be induced in the sublingual glands of adult female mice by treatment with either testosterone propionate or thyroxine; the two hormones give simultaneously acted synergistically in this induction.
An electron microscopic analysis of the left phrenic nerve in the rat
Authors: Langford Lauren A. , Schmidt Robert F.
Published: February 2005

In this electron microscopic study, the axonal categories in the left phrenic nerve at its entrance to the diaphragm have been determined. At a level 3 mm rostral to the diaphragm, the left phrenic nerve contains approximately 700 axons: 57% are myelinated and 43% are unmyelinated. The dorsal root ganglion cells give rise to 31% of the myelinated axons and the ventral root contributes 69%. Of the unmyelinated axons, the dorsal root ganglion cell contributes 59%, the cervical sympathetic chain 24%, and 17% course through the ventral roots. These ventral root unmyelinated axons are presumably preganglionic efferents since the proximal stump of the ventral root showed no decrease in unmyelinated axons after ventral rhizotomy.
A simple method of lung perfusion fixation
Authors: Coalson Jacqueline J.
Published: February 2005

A simple perfusion apparatus modified from procedures used and published in renal studies is presented and discussed. The buffer and fixative solutions to be perfused are placed in closed reservoirs under 20 mm of Hg pressure which is provided by a constant inflow of air from an air inflow valve present in any routine laboratory. The pressure is monitored by a sphygmomanometer gauge and adjusted with an air control valve. The perfusate solutions are kept at 37°C. The oncotic‐osmotic characteristics of routine buffer and fixative perfusates are presented and discussed. The perfusion technique utilized in a cat model is detailed. The technique does not require sophisticated equipment and yet perfusion conditions can be carefully monitored and controlled.
Structural and cytochemical changes in astrocytes from the brain periventricular zone of the copper‐deficient blotchy mouse
Authors: Terr L. I. , Weiner L. P.
Published: February 2005

Porphyrin‐ and endogenous peroxidase‐containing accumulations of cytoplasmic inclusions in astrocytes of the hypothalamic periventricular and arcuate nuclei and periventricular areas of the lateral ventricles except for ependymal astrocytes were observed by fluorescent microscopy and histochemical techniques in the wild type, C57BL/6J, and tabby mice. These cells can be also visualized with phase contrast and dark‐field techniques or by staining sections embedded in polymerized resin with toluidine blue. The brains of heterozygous females and hemizygous males for the blotchy allele (mottled locus on the X‐chromosome) failed to show this specific class astrocytes. The findings described are possibly due to defective copper metabolism in mottled mutants which may include a number of other related abnormalities, including reduced activity of copper‐dependent enzymes such as porphyrin‐containing peroxidases. Sexual differnce in the number of the accumulations in the anatomically and physiologically normal tabby mouse was clearly expressed.
The blood–testis barrier in the toad (Bufo arenarum hensel): A freeze‐fracture and lanthanum tracer study
Authors: Cavicchia Juan C. , Moviglia Gustavo A.
Published: February 2005

Intercellular junctions between Sertoli cells in the toad testis were studied by freeze‐fracture and electron‐opaque intercellular markers. These junctional specializations are characterized in thin sections by a series of focal fusions on the outer leaflets of both adjacent cell plasmalemmas, associated with bundles of fine filaments in the subjacent Sertoli cell cytoplasms. However, the wide subsurface cisterna of the endoplasmic reticulum, a component constantly associated with Sertoli cell junctions in mammals, is absent in the toad. The intravascularly injected lanthanum hydroxide, used as a tracer compound, gains access to the seminiferous tubules and surrounds spermatogonia and leptotene spermatocytes, but is persistently excluded from germ cells in later stages of development. This indicates that, as is the case in the mammalian testis, a permeability barrier to lanthanum is established which isolates all germ cells beyond leptotene spermatocytes.

Freeze‐fracture reveals the characteristic occluding junctions between Sertoli cells, but a variation in their geometric patterns was clearly observed in different regions of the toad seminiferous epithelium. The membrane‐fractured faces of Sertoli cells embracing differentiating spermatids exhibit a deep junctional complex: up to 50 rows of particles between adjacent Sertoli cells separate these late germ cells from the periphery of the seminiferous tubules. Sertoli cells surrounding early germ cells generally exhibit, instead, a discontinuous, poorly developed network of interconnected rows of particles with few widely spaced strands. This seems to permit the percolation of the intercellular marker in areas of the seminiferous epithelium containing spermatogonia and leptotene spermatocytes.
Effects of prior culture or isoproterenol injections on the regeneration of rat submandibular gland autografts
Authors: O'Dell Norris L. , Sharawy Mohamed , Pennington Catherine B.
Published: February 2005

This study compares the acinar cell regnerative response in submandibular gland (SMG) autografts that were cultured before grafting to the rat tongue with the acinar cell regenerative response in direct SMG autografts to the tongue. In addition, the effects of isoproterenol on direct SMG autografts were studied. A portion of the left SMG was excised from each rat and cut into fragments which were autografted either immediately into the middle one‐third of the rat's tongue; or were cultured for 1, 4, or 7 days and then autografted to the donor's tongue. After 8 weeks the rats were killed and the tongues were removed and processed for light microscopic study. The histologic preparations showed evidence of cytodifferentiation into acinar cells in four of the previously cultured SMG autografts. Some of the direct SMG autografts did not contain acinar cells, whereas other direct. SMG autografts contained numerous acinar cells and even straited ducts. In the SMG autografts that were cultured for 1 day before autografting and in the direct SMG autografts, that contained ductlike structures that were apparently connected to the epithelial surface of the tongue. Lastly, isoproterenol appeared to accelerate the regenerative responses in some of the direct SMG autografts, and the drug caused acinar cell hypertrophy in two of the direct SMG autografts.
Afferent and efferent axons in the medial and posterior articular nerves of the cat
Authors: Langford Lauren A. , Schmidt Robert F.
Published: February 2005

The goal of this study is to determine the average numbers of afferent axons and postganglionic autonomic (sympathetic) efferent axons supplying the cat knee joint through the medial and posterior articular nerves. Interestingly, both nerves are composed primarily of unmyelinated axons. Only 20% of the axons in the medial articular nerve are myelinated, with the overwhelming majority, 80%, being unmyelinated. The posterior articular nerve has 78% unmyelinated and 22% myelinated axons. Neither nerve contains ventral root efferent axons. The sympathetic chain, in both nerves, contributes no myelinated and only 50% of the unmyelinated axons. The medial and posterior articular nerves are therefore predominantly afferent, since all myelinated and the remaining 50% of the unmyelinated axons arise from the dorsal root ganglion cell. The ratio of afferent unmyelinated to myelinated axons is 2:1. The roles of these afferent unmyelinated axons must now be considered in regard to joint kinesthetics and pain.
Morphological relations between the receptor neurons, sustentacular cells and Schwann cells in the olfactory mucosa of the salamander
Authors: Rafols José A. , Getchell Thomas V.
Published: February 2005

The morphological characteristics of olfactory receptor neurons and their relations to the sustentacular cells and to the sheath cells of Schwann in the olfactory mucosa of the salamander (Ambystoma maculatum et tigrinum) were studied using a modification of the rapid Golgi technique. The bipolar receptor neurons had a fusiform‐shaped cell body whose apical pole gave rise to a surface‐reachig dendrite and a basal pole which gave rise to an axon. The length and width of the dendrite, although variable, were positively correlated with the relative depth at which the cell body was located in the sensory epithelium. Beyond the initial segment, the axon had a sinuos course prior to its entrance into the lamina propria. Within the lamina propria, the axons were associated with the sheath cells of Schwann to for the olfactory nerve fascicles. The processes of adjacent sheath cells formed an elaborate network of continous cavities through which the axons coursed.

Two morphologically distinct varieties of sustentacular cells, designated types I and II, were found in the sensory epithelium. Both types had a columnar profile cnsisting of an elongated cell body, a central stalk, and a basilar expansion of the stalk found at the junction of the epithelium with the lamina propria. The central stalk of type I sustentacular cells was unbranched, whereas that of type II cells gave rise to riblike processes from which cytoplasmic veils extended to envelop the cell bodies of receptor neurons. The basilar expansions were found in close apposition to the wall of capillaries or to acinar cells of Bowman's glands located in the most superficial region of the lamina propria. The morphological relationships and possible interdependencies among receptor neurons, the types of sustentacular cells, and the sheath cells are discussed.
A numerical identification syterm for airways in the lung
Authors: Mortensen J. D. , Young Johanne D. , Stout Lisa , Stout Alison , Bagley Barry , Schaap Robert N.
Published: February 2005

A numerical sytem for identifying airways at any level in the tracheobronchial tree has been develop which appears to be simple, logical, and accurate. The system has successfully used in the author' laboratory to expedite morphometric studyes of the conduciting airways in the tracheobronchial tree.

Three simpe and direct criteria or rules have been fomulated for assignment of an airway identification number (AIN) to any specific pulmonary airway, according to this identification system.

Some specific applications of this AIN system have been enumerated and several limitations that the authors have recoginzed have been described.

Workers in the fields of bronchial morphometry and anatomy are invited to consider the possible theoretic and practical utility of this airway identification system.
Development of a method for quantitative stress analysis in bones by three‐dimensional photoelasticity
Authors: Bianchi Rossella , Clerici Paolo , Vizzotto Laura , Miani Alberto
Published: February 2005

Comparative critical examination of methods suitable for studying stress in bones have shown that the three‐dimensional photoelastic method is one of the most reliable. Described herein is the method for obtaining, by fusion, full‐scale models in epoxy resin, that are exactly equivalent to external shape of the prototypes.

This technique offers the advantages of being applicable without variation to any bone segment and of enabling a large number of additional resin castings to be made from the same mould. Hence it is possible to produce a very large number of copies of the same bone segment that will be suitable for comparative studies of different load situations.

As an example, quantitative data expressing both surface and internal tension trends in the proximal third of a normal human femur are given.
Blood vessels of the Peyer's patch in the mouse: II. In vivo observations
Authors: Yamaguchi K. , Schoefl G. I.
Published: February 2005

A technique was developed that allowed the in vivo observation of Peyer's patches in the mouse for several hours. Untreated animals and animals depleted of lymphocytes were used. In this species, blood vessels associated with the lymphoid nodules are readily visible through the thin serosal muscle coat. High‐endothelium venules are recognized by the large number of refractile cells that adhere to the luminal surface. A colloidal carbon suspension injected intravenously labeled high‐endothelium venules and was only rarely seen in arterial and capillary segments or in venules of the gut parenchyma. When fluorescein isothiocyanate‐labeled (FITC‐labeled) syngeneic spleen cells were injected, they appeared in vessels of the Peyer's patch within a few seconds and began to adhere to the luminal surface of high‐endothelium venules. In untreated animals, peak numbers of fluorescent cells were reached after about 20 min. Many adhered but some were swept away. In lymphocyte‐depleted animals, however, peak numbers were reached after only a few minutes and most cells remained attached.
Blood vessels of the Peyer's patch in the mouse: III. High‐endothelium venules
Authors: Yamaguchi K. , Schoefl G. I.
Published: February 2005

High‐endothelium venules of mouse Peyer's patches were examined by scanning electron microscopy, and a quantitative assessment was made of the location of lymphocytes in relation to endothelial cells. Untreated mice and mice with markedly depressed levels of circulating lymphocytes were used. Lymphocytes were divided into adhering and migrating cells and as to association either with the body of the endothelial cell or with its cell border. Over 90% of all adhering cells and the great majority of migrating lymphocytes were located at the cell border. The exception was one animal in which most migrating lymphocytes appeared to penetrate the endothelial cells. Our data lend strong support to the currently held view that most migrating lymphocytes traverse the endothelium by following an intercellular path but that, under certain conditions, lymphocytes may penetrate the cytoplasm of endothelial cells.
The soleal line
Authors: Mysorekar Viswanath Ramrao , Nandedkar Asha Narayan
Published: February 2005

The soleal line in 167 left and 163 right tibiae has been studied. The line often does not follow the textbook description. It commences well below the fibular facet and ends well down nearer the middle of the bone on the medial border. It generally shows mixed characters of a line, a wide line, a ridge, ora groove. The line is frequently absent in the upper third. In the middle third, it is seen as a wide line or as a ridge varying from 1 to 2 mm in height. In the lower third the line presents itself as a ridge. In the middle and lower thirds, the line is often seen as a depression varying from 1 to 2 mm in depth. The line shows a left‐sided dominance.
Response of epididymal duct to the temporary depletion of spermatozoa induced by testicular irradiation in mice
Authors: Abe Kazuhiro , Takano Hiroko , Ito Takashi
Published: February 2005

The mouse epididymal duct can be histologically divided into five segments (I‐V), and the principal cells in segment II appear to secrete periodic acid‐Schiff (PAS)‐positive material into the lumen. In this study, male dd‐mice received one, two, or four 800‐R doses of radiation beginning at age 50 days. Mice receiving multiple doses were irradiated at 1‐week intervals.

After irradiation, marked depletion of spermatozoa, or aspermia, occurred in the epididymal duct for 2 to 16 weeks after a latency period of 3 to 4 weeks according to the times of irradiations. During oligospermia or aspermia, PAS‐positive inclusions apeared in the principal cells in segment IV. The inclusions occupied a supranuclear position and appeared as round granules and globules measuring 2–15 μm in diameter, and increased in number, size, and staining intensity with time. They disappeared after reappearance of spermatozoa. The findings suggest that PAS‐positive material may bind to spermatozoa and, if not bound, is reabsorbed by the principal cells in segment IV and deposited as intracellular inclusions, and the prinicipal cells in segment IV and capable of digesting the accumulated PAS‐positive mateial.
Actin filaments in the ameloblast of the rat incisor
Authors: Nishikawa Sumio , Kitamura Hironori
Published: February 2005

The distribution of actin filaments in the inner enamel‐secretory ameloblast of the rat incisor was examined by labelling with heavy meromyosin. Actin filaments were mainly located in the long axis of the cell beneath the cell membrane. They tended to be more numerous in Tomes' process than in the cell body. Some filaments were associated with microtubules, with other actin filaments, and coated vesicles. Possible relation of the actin filaments to cell motility, stabilization of some, and movement of other cellular components is discussed.
Ultrastructural evidence for a reabsorptive role by intrarenal veins
Authors: Jones Warren R. , O'Morchoe Charles C. C.
Published: February 2005

Intrarenal veins, although known to have thin walls, are considered to be simple conducting vessels. Using light‐ and electron microscopy, the distribution and structure of named intrarenal veins was examined qualitatively and quantitatively in rat kidneys fixed by retrograde arterial perfusion. Although the venous system follows the pattern of arterial branching in general, a class of intracortical veins similar in appearance to interlobular veins but without a companion artery was found in the present study. It is suggested that these vesels be designated intralobular veins. Structurally, we have found intrarenal veins to be surprisingly similar to peritubular capillaries both in respect to their spatial relations to renal tubules as well as ultrastructurally. Like peritubular capillaries, the majority of the wall of intrarenal veins is intimately apposed to renal tubules. This fraction decreases centrally, values of 0.83 being obtained in intralobular veins, 0.69 in interlobular veins, and 0.56 in arcuate veins. The walls of intrarenal veins are comprised of little more than an endothelium, which, like peritubular capillaries, is remarkable for its thinness, high density of fenestrae, and lack of extraintimal elements. Endothelial thickness was not significantly greater in either interlobular or arcuate veins than in peritubular capillaries; the fenestrae were, however, about twice as frequent in peritubular capillaries as in interlobular or arcuate veins and 35 times more frequent than in interlobar veins. The size and numerical and volume densities of uncoated endocytotic vesicles did not differ significantly between peritubular capillaries and any of the intrarenal veins. Based on their marked qualitative and quantitative similarities to peritubular capillaries, we conclude that, like the latter, intrarenal veins are capable of sustaining passive transport between plasma and interstitium.
Morphometric analysis of the remodeling of the rat pulmonary epithelium during early postnatal development
Authors: Vidić Branislav , Burri Peter H.
Published: February 2005

In the rat lung the alveoli are formed in the early postnatal period. Within 3 weeks the alveolar surface area increases more than five‐fold and the saccular lung reaches its mature structure. In order to analyse the changes in the compartments of the parenchymal tissue, the lungs of three animals per group aged 4, 13, and 21 days, respectively, were investigated by means of electron microscopic morphometry.

Whereas the capillarisation of the interalveolar septa almost doubled in the period investigated, the endothelium and alveolar epithelium increased their share of the septal tissue at the expense of the interstitial compartment. The cellularity of the interstitium decreased markedly with age, the ratio of cells to interstitial spaces falling from 5.1 to 1.7. Within the epithelium, the type II cell population increased its mass almost six times, representing 58% of the alveolar epithelial volume at 3 weeks. Accordingly, the portion of alveolar surface area covered by type II cells was highest on day 21, with 9% versus 5.6% on day 4, and around 3% in a normal adult lung.

The observed quantitative structural changes are discussed in the light of the functional demands of the organ: the need for an expanding alveolar surface area to be covered by a thin epithelial lining layer, the maintenance of a thin air‐blood barrier, and a quantitatively adapted secretion of alveolar surfactant.
The chorda center in Hensen's node of the chick embryo
Authors: Rosenquist Glenn C.
Published: February 2005

To learn the origin and early migration of notochordal cells in the chick embryo, tritiated thymidine‐labeled grafts were implanted into homologous positions in Hensen's node of recipient embryos at homologous stages of development. The host embryos were reincubated to Hamburger‐Hamilton stages 5–9, fixed, embedded in paraffin, and serially sectioned. Sections were coated with photographic emulsion and exposed for 7–30 days. Labeled cells were found in the notochord or chordamesoderm in 31 of the 35 embryos.

Transplants to the dorsal portion of the node always formed notochord. Transplants to the ventral node formed notochord only when implanted during or after the definitive streak stage (H‐H stage 4+), indicating that the chorda center is located in the dorsal layer. Moreover, the results suggest that the node depletes itself in producing the notochord: labeled cells migrated into notochord or chordamesoderm anterior to the primitive pit, rather than remaining in the node or primitive pit. Because transplants to the anterolateral portion of the node contributed only to trunk notochord and several transplants to the posteromedial portion contributed only to head notochord, Hensen's node may be equivalent to the median lip of a blastopore, over which prenotochordal material in the dorsal (epiblast) layer passes during gastrulation.
A simple technique for the visualization of whole mount cytoskeletons with transmission electron microscopy
Authors: Marek Louis F. , Kelley Robert O.
Published: February 2005

Examination of whole mount cells in the transmission electron microscope has been useful in studies of cellular architecture. The common technique is to grow cells directly on formvar‐coated, gold grids for direct observation through a cell. We report a technique for obtaining whole mount preparations which requires neither fragile formvar films nor expensive, gold grids. Cells are grown on palladium‐coated coverslips and processed for electron microscopy. The cells and the palladium substrate are separated from the coverslip. The cell‐palladium complex is then picked up on copper grids as in thin section processing. We compare images of the cytoskeleton using our technique with images using previously described techniques and present preliminary observations of contracting cell models. Such contractions would tear formvar films if attempted on cells grown in the conventional manner for whole mount examination. Our technique allows cells to contract without tearing the underlying substrate.
Cell production in mouse intestinal epithelium measured by stathmokinetic flow cytometry and coulter particle counting
Authors: Cheng Hazel , Bjerknes Matthew
Published: February 2005

The rate of cell production in the crypt population of the intestinal epithelium has been determined previously. However, the complex geometry of the tissue makes determination of the rate of cell production in the epithelium as a whole, by traditional methods, extremely difficult if not impossible. In this report, stathmokinetic flow cytometry was used for the direct determination of the rate of cell production in the mouse intestinal epithelium. Mice were given an intraperitoneal injection of colcemid (2.5 mg/ kg) and killed 25, 45, 65 and 90 min after injection. The percentage of cells with 4N DNA (G2 and M phase cells) in the epithelium at each time interval was determined with flow cytometry. The results were fitted by linear regression and the rate of cell production derived from the slope of the regression line. Thus, the rate of cell production was found to be 1.86% ± 0.44 (x ± SE) per hour in the jejunal epithelium and 1.66% ± 0.48 per hour in the colonic epithelium. The turnover time of the epithelium as a whole was determined from the inverse of the rate of cell production, and was found to be 53.8 h ± 12.6 in jejunum and 60.2 h ± 17.3 in colon. Coulter particle counting was used to measure the number of cells in the intestinal epithelium. The number of epithelial cells was found to be 1.90 × 107 ± 3.11 × 105 cells per cm2 in the jejunum and 8.98 × 106 ± 8.05 × 105 cells per cm2 in the colon. A number of other kinetic parameters, which were not available, were derived from the values determined in this study. For example, it was estimated that 3.53 × 105 ± 8.33 × 104 cells were produced per cm2 per hour in the jejunal epithelium, and 1.49 × 105 ± 4.45 × 104 cells per cm2 per hour in the colonic epithelium. The rate of cell production at the level of the crypt was found to be 25.1 ± 6.44 cells per crypt per hour in the jejunum, while in the colon 16.4 ± 5.20 cells were produced per crypt per hour. In the jejunum, it was concluded that on the average, about 241.0 ± 65.8 cells were lost each hour from a villus. The kinetic profle of the crypt was also derived. There were on the average about 609.0 ± 50.5 cells per crypt in the jejunum and 985.0 ± 77.98 cells per crypt‐surface epithelium unit in the colon. Of these, about 310 cells constitute the cycling population in a jejunal crypt while about 305 cells constitute the cycling population in a colonic crypt‐surface epithelium unit. The cycling population in a jejunal crypt was distributed approximately as follows: 91 cells in the G1 phase, 171 cells in the S phase, 48 cells in the G2 + M phases. The cycling population in a colonic crypt‐surface epithelium unit was distributed approximately as follows: 140 cells in the G1 phase, 124 cells in the S phase, and 41 cells in the G2 + M phases.