bluuebunny/crossref_metadata_2025 huggingface dataset:
Chronic infusion of opiate peptides to rat cerebrospinal fluid with osmotic minipumps
Authors: Saland L. C. , Ortiz E. , Samora A.
Published: February 2005

Beta‐endorphin‐related opiate peptides or the opiate antagonist naloxone were chronically infused for periods of 24 to 48 hours to the lateral cerebral ventricle of adult male rats using Alza osmotic minipumps. Previous studies have suggested a “chemotactic”‐like effect of opiate peptides for supraependymal macrophages in the region of the third ventricle of the brain. The present study demonstrates a stimulatory effect of beta‐endorphin infusion on the appearance of lymphocyte and neutrophil‐like cells, in addition to macrophages, in the region of the third ventricle, suggestive of an intracerebral inflammatory response. None of the other molecules, including alphaendorphin, methionine‐enkephalin, naloxone, or sterile saline produced similar cellular responses after infusion, although some of the latter substances may have induced the appearance of supraependymal neuron‐like cells in the area. Observations suggest that the chronic presence of beta‐endorphin, a biologically active opiate peptide, will interact with cells of the immune system, which have the ability to gain access to the cerebrospinal fluid.
Structural development of the feline mental nerve
Authors: Fried K.
Published: February 2005

The qualitative and quantitative structural development of the feline mental nerve (MN), a branch of the inferior alveolar nerve (IAN), was studied by electron microscopy from 40 days postconception (dpc) (about 2 weeks before birth) to 11 years after birth. Myelination was initiated at 40–45 dpc. At 2 months after birth de novo myelination was completed, and the larger myelinated axons had achieved a fully differentiated nodal‐paranodal morphology. Size growth of myelinated axons continued until 6 months, when a bimodal size distribution between 1 and 12 months was established. When compared to the IAN, the MN contained a higher proportion of unmyelinated axons. Age‐related signs of axon degeneration, which previously were recorded in the IAN, were lacking in the MN. This suggests that senescent IAN axon degeneration is related to dental rather than to cutaneous MN branches.
An autoradiographic study of the mouse olfactory epithelium: Evidence for long‐lived receptors
Authors: Hinds James W. , Hinds Patricia L. , McNelly Nancy A.
Published: February 2005

In order to try to determine whether differentiated olfactory receptors turn over (die and are replaced by newly differentiated cells) during adult life, mice were injected with a single dose of 3H‐thymidine at either 2 or 4 months of age and allowed to survive for up to 12 months; they were caged in a laminar flow unit to prevent rhinitis. Counts of labeled receptor cells detected autoradiographically after injection at 2 months of age revealed that, following an initial decrease from 1 to 3 months of survival, numbers of labeled cells remained approximately constant, at least up to 12 months of survival. Cells still labeled at 12 months of survival were confirmed as receptor cells by electron microscopic examination of reembedded sections. The hypothesis is suggested that in the absence of disease‐related destruction of the olfactory epithelium, most or all receptor cell turnover represents newly formed cells that fail to establish synapses with the olfactory bulb; fully differentiated receptor cells may be quite long‐lived.
Ultrastructural localization of glycosaminoglycans in human term placenta
Authors: Parmley R. T. , Takagi M. , Denys F. R.
Published: February 2005

Sulfated glycoconjugates were stained in normal human term placentas using Spicer's high‐iron diamine (HID) method with thiocarbohydrazide and silver proteinate (TCH‐SP) enhancement. Specific identification of glycosaminoglycans (GAG) was accomplished by digestion of the stained material with chondroitinase ABC or AC for removal of chondroitin sulfates and nitrous acid for removal of N‐sulfated GAGs. The syncytiotrophoblast apical surface demonstrated moderate to intense staining with HID‐TCH‐SP, which was removed by prior digestion with the chondroitinases, but not by nitrous acid. The syncytiotrophoblast basal surface and endothelial cell surfaces lacked sulfate staining. A few cytoplasmic granules in syncytiotrophoblast cells demonstrated staining similar to the apical surface. Three layers of the basal lamina were identified in these preparations. The lamina lucida immediately beneath the syncytiotrophoblast and the majority of the lamina densa stained weakly or not at all, whereas the underlying lamina diffusa and stroma demonstrated moderate to intense staining. The majority of lamina diffusa staining was removed by chondroitinase ABC or AC; the remaining material was removed by nitrous acid digestion. Thus the syncytiotrophoblast surface contains a chondroitin sulfate and the basal lamina contains a mixture of intensely stained chondroitin sulfate and a weakly stained N‐sulfated GAG.
The value of graphic reconstructions—comparison with scanning electron microscopy
Authors: Wenink Arnold C. G. , Chon Yong
Published: February 2005

Because knowledge of spatial morphology of the human embryonic heart mainly derives from serial microscopic sections and from reconstructions based on such series, it might be questioned whether the results obtained are comparable with animal studies in which scanning electron microscopy is used. Therefore, pig embryo hearts of the same developmental stage were processed for routine histological sectioning as well as for scanning electron microscopy. A graphic reconstruction was made of a right ventricular view, to be compared with a similar scanning micrograph. The two images, produced by much different techniques, were strikingly similar. In addition, the graphic reconstruction technique is complementary to scanning electron microscopy, because histological details can be introduced.
Redistribution of gastric K+‐NPPase in vertebrate oxyntic cells in relation to hydrochloric acid secretion: A cytochemical study
Authors: Koenig Cecilia S.
Published: February 2005

Gastric K+‐NPPase represents a partial reaction of the (K+‐H+)ATPase system, which is considered to be the proton pump in mammalian parietal cells. In the present paper, K+‐NPPase activity was cytochemically studied by the method of Mayahara et al. (1980) in gastric glands of birds, amphibia, and mammals, either in the resting state induced by cimetidine or after stimulation of HC1 secretion by histamine.

The gastric K+‐NPPase cytochemical reaction was localized only in oxyntic cells of the gastric mucosa in the three species tested.

The subcellular distribution of the K+‐NPPase reaction product drastically changes with the secretory state of HC1. In resting cells, the K+‐NPPase staining is associated with the membranes of the endocellular tubular system while in HC1‐secreting cells, it is associated with the plasma membrane of the elaborate secretory surface characteristic of this functional state. The above results demonstrate that the same enzymatic activity, which is associated with the gastric proton pump, is present in both membranous systems of the oxyntic cell secretory pole. This fact supports the proposal that the tubular system represents a membrane reserve that inserts the proton pump into the luminal plasma membrane in vertebrate oxyntic cells under the action of HC1 secretagogues.
The development of the osmiophilic inclusion bodies within the granular pneumocyte of chicken lung
Authors: López J. , Sesma P. , Vázquez J. J.
Published: February 2005

The origin and development of osmiophilic inclusion bodies (OIB) type A of granular pneumocytes were morphologically studied in chicken lungs. The OIB type A were formed by a process of twisting and progressive spiralling of profiles of the rough endoplasmic reticulum (RER). No evidence has been found in favor of a mitochondrial or Golgi‐related origin of OIB.
Ultrastructural characterization of glial cells in the rat pineal gland with special reference to the pineal stalk
Authors: Luo Z. R. , Schultz R. L. , Whitter E. F. , Vollrath L.
Published: February 2005

In the present study the “interstitial” cells of the superficial pineal gland and the nonparenchymal cells of the pineal stalk in Sprague‐Dawley rats were examined ultrastructurally with the aim of defining the cells more closely. The “interstitial” cells of the superficial pineal gland do not represent a homogeneous cell population. The most abundant cell type is the mononuclear phagocyte, most easily recognized by its dark appearance and its content of primary and conspicuous secondary lysosomes. Astrocytes can be distinguished by the typical appearance of their nuclei (i.e., a thin continuous rim of heterochromatin adjacent to the nuclear membrane), identical to that of astrocytes in the CNS. Depending on the absence or presence of glial filaments and their amount, a spectrum of astrocytic cells is present. Mature astrocytes with filaments throughout their cytoplasm are rare. Immature glial cells with few or no filaments predominate. In the vicinity of blood vessels pericytes are present. In view of the fact that the “interstitial” cells could generally be identified it is suggested to abandon the term interstitial for the cells in question. In the pineal stalk mature astrocytes predominate; they have some features in common with pinealocytes, i.e., the presence of intergrade endoplasmic reticulum and grumose bodies (lysosomes). Other unusual features are a relative abundance of coated pits and vesicles. Oligodendrocytes are restricted to the proximal part of the stalk, near the deep pineal, where myelinated axons are abundant. More distally a few Schwann cells were seen.
Alterations of lmmunoreactive somatostatin in thyroid C cells after induced hypercalcemia, hypocalcemia, and antithyroid drug treatment
Authors: Kameda Yoko , Ito Miyoshi , Ogawa Koichi , Tagawa Takasuke
Published: February 2005

In order to elucidate the functional significance of somatostatin in thyroid C cells, the alterations of immunoreactive somatostatin in the cells were investigated under various experimental conditions, i.e., hypercalcemia, hypocalcemia, and antithyroid drug treatment. Guinea pigs and rabbits, in which almost all C cells reveal the intense immunoreaction for somatostatin in addition to calcitonin, were used as experimental animals. After chronically induced hypercalcemia, somatostatin immunoreactivity conspicuously diminished coinciding with the decrease of calcitonin; somatostatin as well as calcitonin was responsive to induced hypercalcemia. After hypocalcemic tetany induced by injection of Escherichia coli Lasparaginase, C cells exhibited very intense immunoreactions for both calcitonin and somatostatin. After chronic treatment of ethylenethiourea, immunoreaction of somatostatin in C cells was the same as that of calcitonin. That is, when immunoreactivity for calcitonin remained unchanged, immunoreactivity for somatostatin was also intensive. However, when immunoreaction of calcitonin became very weak, the reaction of somatostatin was also weak. Thus, in all experimental conditions examined the alterations of immunoreactive somatostatin in C cells completely coincided with those of calcitonin. It seems likely that somatostatin in thyroid C cells exerts the synergistic effect on calcitonin action.
Autoradiographic localization of 3H‐digoxin binding by neural cells in the medulla
Authors: Traurig H. H. , Bhagat A. , Bass N. H.
Published: February 2005

The purpose of this investigation was to localize binding sites for the cardiac glycoside digoxin in the medulla of the rat in vivo. Adult male Sprague‐Dawley rats were injected (IV) with 3H‐digoxin and killed 30 minutes later. Autoradiographs of medullas showed evidence of 3H‐digoxin binding to small‐ and medium‐sized neural cells in the regions of the nucleus solitarius, dorsal motor nucleus of the vagus, area postrema, and in the zone between the area postrema and the underlying neuropil. However, the parasympathetic preganglionic neurons of the dorsal motor nucleus were not labeled. The 3H‐digoxin‐labeled cells in the medulla were located mainly in the commissural and medial portions of nucleus solitarius at the level of the area postrema. Animals injected with unlabeled digoxin followed by 3H‐digoxin showed reduced binding of radioactivity.

The small‐ and medium‐sized neurons of the caudal portions of the nucleus solitarius are internuncial in position with respect to cardiovascular afferents of the glossopharyngeal and vagus nerves and sympathetic and parasympathetic cardiovascular efferent neurons of the medulla. The results of this study suggest that these 3H‐digoxin‐labeled cells, presumably neurons of nucleus solitarius, may possess high affinity binding sites for digoxin. Further, the area postrema, which lacks a blood‐brain barrier, may provide a portal of entry for 3H‐digoxin into regions of the medulla known to contain neurons that play a role in the regulation of cardiac rhythm.
Transport of horseradish peroxidase across monkey trophoblastic epithelium in coated and uncoated vesicles
Authors: Wilson Jean M. , King Barry F.
Published: February 2005

This study used membranous chorion of the macaque monkey placenta to examine uptake and processing of exogenous proteins. Tissue was incubated with either cationic or anionic horseradish peroxidase. Incubation time was varied between 5–25 min to follow the endocytic pathways. In spite of some differences in binding, uptake and processing of the isozymes was similar. In the presence of tracers at 37°C both horseradish peroxidases were taken up in large (150–175) nm diameter coated vesicles. In addition, coated tubules 300–400 nm in length and 50–100 nm in diameter were seen in the apical cytoplasm. Often, the tubules bud off small (85–105 nm diameter) protein‐filled coated vesicles which traversed the cytoplasm and fused with the basal‐lateral plasma membrane. In other cases, the tubules or vesicles lost their clathrin coats and fused to form larger endocytic vesicles which later fused with phagolysosomes. After longer incubation, larger uncoated vesicles (endosomes) were seen releasing their contents at the basal‐lateral membrane. These results suggest that multiple transport pathways exist in this epithelium. The first, involving only coated structures, may function to sort and concentrate specific ligands important for embryonic development. The second, involving the formation and translocation of large uncoated vesicles to the basal‐lateral membrane, may also provide nutrients to the embryo. A third pathway directs the protein to phagolysosomes where it is presumably degraded. Degradation products could be used by the cells of the membranous chorion or may provide nutrients to the embryo.
The relation of nucleolus diameter to cell body diameter in mammalian dorsal root ganglion cells
Authors: Coggeshall Richard E. , Chung Kyungsoon , Bee David E.
Published: February 2005

The present study correlates cell body and nucleolar sizes for dorsal root ganglion cells in the rat. To do this, we measured cell body areas and calculated their diameters and measured nucleolar diameters for 719 cells. These data indicate that there is a correlation in that increasing cell size is associated with increasing nucleolar size. However, there is considerable variability of cell body size for each nucleolar diameter and vice versa. Nevertheless, when nucleolar diameters are grouped, the function In D = 1.687 + 0.334 dr, where D is the diameter of the cell body and dr the rounded diameter of the nucleolus, produced an almost straight line. Thus this formula provides a good estimate of the relation of nucleolar and cell body sizes for dorsal root ganglion cells of the rat. In addition, estimates of the variances of cell body size at each nucleolar diameter are provided.
Assemblies of linear arrays of particles in the apical plasma membrane of mitochondria‐rich cells in the gill epithelium of the atlantic hagfish (Myxine glutinosa)
Authors: Bartels Helmut
Published: February 2005

In the gill epithelium of the Atlantic hagfish Myxine glutinosa a mitochondria‐rich cell type is described which ultrastructurally resembles the chloride cells in other fish species. Freeze‐fracture replicas reveal different supramolecular structures in the luminal plasma membrane and in the intracellular amplification (tubular system) of the basolateral plasma membrane of these mitochondria‐rich cells. In the luminal plasma membrane ordered assemblies of particles and fibril‐like elements are regularly found. On the P face, the assemblies are composed of up to 20 linear arrays of particles which are preferentially located in the microvillar membrane on which they show a helicoidal orientation. The arrays are formed by globular (diameter 8–9 nm) and rod‐shaped (length 16–20 nm) particles, which occasionally are so tightly end‐to‐end attached that they generate fibril‐like structures. The distances between adjacent arrays within an assembly measure 10–15 nm. On the E face complementary patterns of linear grooves are present. These assemblies have not previously been demonstrated in the freeze‐fractured plasma membrane of branchial chloride cells. In the membrane of the tubular system, emerging from the basolateral plasma membrane of the mitochondria‐rich cells, infrequently repeating rows of 7–8 nm particles are present in addition to randomly distributed globular particles (diameter 7–8 nm). Complementary patterns of grooves are present on the E face. These intramembranous structures resemble the repetitive elements which have been previously described in the tubular system of branchial chloride cells in euryhaline teleosts and the subunits of which are considered to be the sites of ion pumps.
Network and lamellar structures in the tail muscle fibers of the metamorphosing anuran tadpole
Authors: Sasaki Fumie , Horiguchi Tsuyoshi , Takahama Hideki , Watanabe Kyozo
Published: February 2005

Networks of regularly arranged tubular units and lamellar structures were observed in the degenerating tail muscle fibers of spontaneously metamorphosing anuran tadpoles. These networks appeared to be similar to those previously found in the skeletal muscle of other animals under abnormal conditions. They stained clearly with ruthenium red (RR) and a continuity with the transverse tubular system (T tubules) of triads was clearly observed. The diameter of the tubular unit, 20–25 nm, was almost equal to that of the T tubules of the intact tail muscle fibers, indicating the network structures were probably formed by T tubules connecting together. In the early stages of metamorphosis, networks in the tetragonal configuration were observed within the end region of the muscle fibers. At the climax of metamorphosis, well‐developed networks in which the tubular units were arranged in a hexagonal pattern were seen in various regions of the fibers. Other observed lamellar structures may originate from lateral elements of the triads. The formation of the network structure is discussed.
Fine structure of the forelimb regenerate of the african clawed toad, xenopus laevis
Authors: Furlong Stephen T. , Heidemann Merle K. , Bromley Stephen C.
Published: February 2005

Forelimb regenerates from postmetamorphic Xenopus froglets were examined at various stages postamputation by light microscopy and scanning and transmission electron microscopy. The outside surface of the wound epithelium was found to exhibit progressive changes following amputation with a distinct difference in appearance between stump epidermis and wound epithelium at all stages examined. The internal structure of the wound epithelium is characterized by loosely arranged cells with numerous cell junctions and abundant intracellular filaments. The wound epithelium is separated at an early stage from the underlying cells by a thick band of extracellular matrix. Cells accumulating beneath the wound epithelium were morphologically similar to blastemal cells from completely regenerating limbs in other species but no evidence of myogenesis or abortive myogenesis was seen. Blastemal cells from the central portion of the regenerate were observed at varius stages of chrondrogenesis with those immediately beneath the wound epithelium least advanced in this respect. Those located more laterally appear not to be directly involved in chondrogenesis. Although the usual explanation for lack of complete regeneration in this species is inadequate innervation of the regenerate, the fine structure of the regenerating spikes noted here is markedly different than that of denervated, amputated newt limbs.
Immunohistochemical localization of neurotensin in hamster adrenal medulla
Authors: Pelto‐Huikko Markku , Salminen Tapio , Partanen Matti , Toivanen Matti , Hervonen Antti
Published: February 2005

Neurotensin‐like immunoreactivity was localized in nerve fibers and terminals of hamster adrenal medulla at light and electron microscopy using the peroxidase‐antiperoxidase method. Numerous varicose neurotensin‐immunoreactive nerves and terminals were found among nonlabeled cell groups situated peripherally in the adrenal medulla. Combined formaldehyde‐glutaraldehyde (Faglu) fluorescence and immunohistochemistry of the same vibratome section showed that only norepinephrine cells were innervated by neurotensin‐immunoreactive nerves. All norepinephrine cells seemed to be innervated by neurotensin‐immunoreactive nerves. Neurotensin‐immunoreactive nerves disappeared after extrinsic denervation of the adrenal gland. By electron microscopy numerous neurotensin‐immunoreactive terminals were seen to make synaptic contacts with norepinephrine cells and with autonomic ganglion cells present in small numbers among norepinephrine cells. In the terminals neurotensin‐like immunoreactivity was localized mainly in large dense‐cored vesicles, but some precipitates were also associated with small vesicles, diffusely scattered in the axoplasm. The present findings suggest that in the hamster adrenal medulla part of the nerve terminals arising from splanchnic nerves contain neurotensin‐like peptide. The functional significance of these nerves in the hamster adrenal medulla remains to be elucidated.
Morphological studies on the distribution of enamel matrix proteins using routine electron microscopy and freeze‐fracture replicas in the rat incisor
Authors: Bai P. , Warshawsky H.
Published: February 2005

Enamel contains two categories of biochemically characterized proteins. Amelogenins are dissociated from enamel without physical disruption of the tissue whereas enamelins are obtained only when the crystallites are dissolved. Ultrastructural visualization of these proteins was attempted using routine electron microscopy and freeze‐fracture replicas. Fresh, fixed, and 4.0 M guanidine‐HCl‐extracted samples of enamel from the secretory (young) and maturation (maturing) stages were compared. Decalcified and stained thin sections of fixed enamel revealed intercrystallite particulate material and “crystallite ghosts” which were identical to the crystallites themselves in young enamel and which corresponded to the periphery of the crystallites in maturing enamel. In contrast, 4.0 M guanidineextracted enamel contained no intercrystallite particulate material but only “crystallite ghosts.” Globular particles observed in freeze‐fracture replicas of fresh and fixed enamel samples were also removed by 4.0 M guanidine extraction. Incubation of guanidine‐extracted enamel with albumin and ovalbumin solutions restored the globular particles. It was concluded that amelogenins are the nonstructural, heterodispersed particulate material in the intercrystallite space. Enamelins constitute the integral template protein which initially provides for elongation of enamel crystallites. They then regulate the continuous growth in width and thickness during maturation and are progressively displaced to the periphery. The illusion that these “protein ghosts” are contained within the crystallite profile can be explained by the parallelepiped shape of the crystallite segment in thin sections.
Structure of the avian kidney
Authors: Morild I. , Bohle A. , Christensen J. A.
Published: February 2005

The kidneys from 6 domestic fowl were fixed in situ by perfusion from the left ventricle. In the bird there are two types of nephrons. One reptiliantype without Henle's loop and medullary tissue, and one mammalian‐type with Henle's loop lying in medullary tissue. Serial sections from kidney tissue embedded in plexiglass or in paraffin were used to study the architecture of eight reconstructed reptilian‐type nephrons from different cortical levels. All reconstructed nephrons had four major bends, but particularly in the subcapsular nephrons additional bends parallel to the kidney surface were found. There was no loop of Henle, but before entering the collecting duct the distal tubule usually had a very thin‐walled segment. No proximal convoluted part was found in the reptilian‐type nephrons. The length of the tubules varied between 3,000 μm and 6,000 μm. In the distal tubule a macula densa segment was found in all nephrons of the reptilian and mammalian type. The capillary network between the inter‐ and intralobular veins was composed of increasingly larger capillaries towards the intralobular vein. Segments of the distal tubule were indented into these capillaries and completely surrounded by them. In the nephrons of the mammalian type the proximal tubule was found to be convoluted as is usual for mammalian species.
Distribution and characterization of anionic sites in trophoblast and capillary basal laminas of human placental villi
Authors: King Barry F.
Published: February 2005

The distribution of anionic sites was studied in the trophoblastic and fetal capillary basal laminas of developing human placental villi with the cationic stain ruthenium red. At 7–12 weeks of gestation the trophoblastic basal lamina (TBL) contained ruthenium red‐positive granules in a quasi‐regular array throughout the lamina densa or sometimes concentrated at the interstitial surface of the lamina densa. The capillary basal lamina (CBL) (and anionic sites) were not present at this age. Anionic sites were also associated with collagen or reticular fibrils. At term, the TBL was largely devoid of anionic sites except for some distributed along its interstitial surface. The CBL was present in later gestation and sometimes had arrays of anionic sites. In order to characterize the anionic sites, minced pieces of villi were incubated in the presence or absence of either chondroitinase ABC, heparitinase, neuraminidase, or Streptomyces hyaluronidase in appropriate buffer systems. Incubation of early villi with heparitinase resulted in the disappearance of the TBL‐associated sites. Chondroitinase ABC appeared to reduce staining of collagen‐associated sites. In term villi, heparitinase removed those few sites still associated with the TBL but did not affect sites associated with the CBL or collagen. Chondroitinase ABC resulted in the disappearance of all anionic sites. In later gestation, a number of developmentally important macromolecules are transported across the trophoblast and enter the fetal capillaries. We conclude that the absence of an array of polyanionic sites from the term placenta TBL and the reduction in the amount of extracellular matrix intervening between the trophoblast and capillaries are adaptations to enhance the exchange of macromolecules across the placenta.
A possible mechanism of partial twinning in a calf
Authors: Easton Thomas W.
Published: February 2005

A two‐headed calf had doubled heads and necks, externally normal forelimbs and thorax, incompletely doubled hearts and lungs, and a persistent sinus venosus, with abnormal pulmonary and systemic circulation. Study of the specimen indicated that partial twinning involved the development of the notochord as an anteriorly branched structure, with retention of the single condition posteriorly. It is proposed that anteroposterior compression of the embryonic disk could have induced the formation of double notochords. The way in which compression was produced is suggested.
Age does not affect numbers of taste buds and papillae in adult rhesus monkeys
Authors: Bradley Robert M. , Stedman Hazel M. , Mistretta Charlotte M.
Published: February 2005

Taste buds and papillae in tongues of rhesus monkeys were examined and counted to determine if there are age‐related differences in general morphology or numbers of receptor organs. Tongues from 15 monkeys in five groups aged 4–31 years were studied with light microscopy. Fungiform, circumvallate, and foliate papillae were examined and taste buds in each papilla type were counted. Numbers of papillae did not differ with age through 31 years; however, at 24 years and older, fungiform papillae were reduced in number in some animals that had lost tongue tips due to trauma. There were no age‐related differences in numbers of taste buds in any of the three gustatory papilla types, nor did taste bud diameter alter with age. From data on each papilla type, estimates were made of total numbers of lingual taste buds. Totals ranged from about 8,000 to 10,000 and there were no agerelated differences. These results support other recent reports that taste buds are not decreased in number in old rats or humans. Since taste bud numbers and general morphology are maintained even in old age, any age‐related differences in taste behavior cannot be attributed to gross degenerative changes in lingual taste buds.
Changes in the nuclear uptake and retention of 3H‐estrogen in gonadotrophs and lactotrophs as a function of age
Authors: Nogami H. , Yoshimura F. , Herbert D. C. , Aufdemorte T. B. , Gates G. A. , Holt G. R. , Sheridan P. J.
Published: February 2005

A quantitative autoradiographic immunocytochemical study was performed in which the nuclear uptake and retention of 3H‐estradiol (3H‐E2) by luteinizing hormone (LH) and prolactin (PRL) cells was examined in 19–21‐year‐old baboons. 3H‐E2 concentrating cells were found in all of the three lobes of the pituitary in varying percentages (38.7%, pars distalis; 17.1%, pars intermedia; 6.3%, pars nervosa). Approximately 80% of PRL cells and nearly 100% of LH cells were labeled. A count of the number of silver grains over nuclei revealed a marked variation of the accumulation of 3H‐E2 by LH cells and to a lesser extent in PRL cells. These results suggest functional heterogeneity among LH and PRL cells. The present results are discussed in relation to the physiological state of old animals.
An ultrastructural morphometric analysis of the adenohypophysis of lactating rats
Authors: Cinti Saverio , Sbarbati Andrea , Marelli Mariella , Osculati Francesco
Published: February 2005

A morphometric analysis of the adenohypophysis (pars distalis) of lactating rats was carried out by a semi‐automated method at the ultrastructural level. The cellular elements were identified by their ultrastructural morphology. The following values were considered for the morphometric study: numerical density of cells/mm3 of tissue and the percentage of parenchymal volume occupied by every cell type. Mammotropes (PRL cells) numbered 624 × 103/mm3 and occupied 59.9% of the parenchymal volume (p.v.). Somatotropes (GH cells) numbered 206 × 103/mm3 and occupied 15.0% of the p.v. Folliculo‐stellate cells (FS cells) numbered 128 × 103/ mm3 and occupied 8.1% of the p.v. Gonadotropes (GN cells) numbered 47 × 103/mm3 and occupied 6.0% of the p.v. Adrenocorticotropes (ACTH cells) numbered 45 × 103/Vmm3 and occupied 3.8% of the p.v. Thyrotropes (TSH cells) numbered 36 × 103mm3 and occupied 3.4% of the p.v. PRL cells were characterized by aspects compatible with intense hormone production. GH cells did not show differences with those of nonlactating animals. Folliculo‐stellate elements appeared hypertrophic with abundant cytoplasm, enlarged Golgi complex, and dilation of the follicular lumina. GN cells had abundant cytoplasm with a well‐developed and dilated ergastoplasm, particularly in type II GN cells. ACTH cells did not show differences with those of nonlactating animals. TSH cells showed moderate nucleocytoplasmic activation. These fine structural morphometric findings are discussed in relation to other studies regarding nonlactating adenohypophysis and hormone changes during lactation.
A three‐dimensional reconstruction of high endothelial venules in the mouse lymph node:An enzyme‐histochemical study
Authors: Müller Edith , Stempfel Sonia
Published: February 2005

A three‐dimensional reconstruction of high endothelial venules (HE‐venules) of an entire mouse lymph node is presented. The reconstruction has been made by means of the histochemical technique for α‐naphthylacetate esterase. The course of the HE‐venules is shown in coherence with lymphocytic aggregates (follicles and unit), which were concomitantly reconstructed.

Carbonic anhydrase, glutamate‐, and α‐glycerophosphate dehydrogenase were found in the high endothelia, while calcium‐stimulated NA+ K+ ATP‐ase and the acetylcholinesterase were localized to the endothelia and/or to the perivascular sheath of the HE‐venules and submarginal capillaries.
Whether blood is contained in the arteries of the living animal by Galen of Pergamon: A translation
Authors: Goss Charles Mayo , Chodkowski Elizabeth Goss
Published: February 2005

Dr. Charles Mayo Goss was professor and chairman of the Department of Anatomy at the University of Alabama (1938–1947) and at Louisiana State University Medical School (1947–1965) and continued to teach after he retired at George Washington (1966–1975) and South Alabama (1975–1981). He edited the 25th, 26th, 27th, 28th, and 29th American editions of Gray's Anatomy. He also was editor of The Amatomical Record for 20 years (1948–1968). His research was on the heart in very early mammalian embryos.

He became very interested in the works of Galen and translated five of them. The sixth was published after his death and co‐authored by his daughter Elizabeth Goss Chodkowski. He was anxious to show that many “errors” attributed to Galen are mistakes of translation, interpretation, or understanding.
Multicellular tumor spheroid interactions with bone cells and bone
Authors: Wezeman Frederick H. , Guzzino Katheryn M. , Waxler Beverly
Published: February 2005

In vitro coculture techniques were used to study HSDM1C1 murine fibrosarcoma multicellular tumor spheroid (HSDM1C1‐MTS) interactions with mouse calvarial bone cells having osteoblastic characteristics and mouse bone explants. HSDM1C1‐MTS attached to confluent bone cell monolayers and their attachment rate was quantified. HSDM1C1‐MTS interaction with bone cells was further demonstrated by the release of 3H‐deoxyuridine from prelabeled bone cells during coculture with multicellular tumor spheroids. HSDM1C1‐MTS‐induced cytotoxicity was mimicked by the addition of 10−5 M prostaglandin E2 (PGE2) to 3H‐deoxyuridine‐labeled bone cells. The effects of low (10−9 M) and high (10−5 M) concentrations of PGE2 on bone cell proliferation were also studied. Higher concentrations of PGE2 inhibited bone cell proliferation. HSDM1C1‐MTS resorbed living explants in the presence of indomethacin, suggesting that other tumor cell products may also participate in bone resorption. HSDM1C1‐MTS caused direct bone resorption as measured by the significantly elevated release of 45Ca from prelabeled, devitalized calvaria. However, the growth of a confluent bone cell layer on devitalized, 45Ca‐prelabeled calvaria resulted in a significant reduction in the amount of 45Ca released subsequent to the seeding of HSDM1C1‐MTS onto the explants. Bone cells at the bone surface may act as a barrier against invasion and tumor cell‐mediated bone resorption. Violation of this cellular barrier is achieved, in part, by tumor cell products.
Scanning electron microscopy of basolateral surfaces of rat renal tubules isolated by sequential digestion
Authors: Jones David B.
Published: February 2005

Renal tubular cells and segments isolated by a trypsin, pepsin, pronase E digestion procedure were studied with scanning electron microscopy. The basal and lateral surfaces of S1, S2, S3 proximal tubular (PT) segments, descending and ascending thin limbs of Henle (TL), distal ascending thick limb of Henle, or distal straight tubule (DST) and distal convoluted tubule (DCT) segments, connecting tubules (CNT), and collecting ducts (CD) were identified and characterized. The basal processes of the S1 and S2 PT cells were fan shaped, were oriented in a circumferential direction, and terminated in microvilli at the basement membrane. S3 PT cells had microvillous basal processes mainly on the lateral edges of the cells. The basal processes of DST and DCT were similar to PT in orientation but terminated on the basement membrane with flattened, thin attachments. The long‐loop descending TL and the ascending TL exhibited distinctive interdigitating cell processes. TL segments with simple contours were present in smaller numbers and were characteristic of short‐loop descending limbs. CNT showed some cells with basal surfaces resembling DCT cells and others resembling CD cells. Both cortical and medullary CD segments exhibited intercalated cells with round basal contours and a sparse pattern of basal infolding clefts. The cortical CD principal cells revealed a much more elaborate mosaic of plicae, clefts, and microvilli than those of the medullary CD. These observations extend the previous knowledge gained from transmission electron microscopy and assist in the interpretation of that knowledge.
Topographical studies of lymphocyte localization using an intracellular fluorochrome
Authors: Brenan M. , Parish C. R. , Schoefl G. I.
Published: February 2005

A procedure for analysing the topographical localization in tissue sections or whole‐organ mounts of lymphocytes labelled with an intracellular DNA‐binding fluorochrome, Hoechst dye No. 33342, is described. The localization, of intravenously injected lymphocytes in spleen, popliteal lymph nodes, and Peyer's patches was followed up to 7 days. In the case of spleen, both B and T lymphocytes initially localised in the marginal zone. Subsequently, B cells appeared to exit via the red pulp, while T cells aggregated around vessels in the white pulp. In Peyer's patches, B and T lymphocytes localized to different lymphoid areas. The advantages and potential applications of this technique are discussed.
Renal microvasculature of the rainbow trout, Salmo gairdneri: Scanning electron microscopy of corrosion casts of glomeruli
Authors: Brown J. Anne
Published: February 2005

Scanning electron microscopy of corrosion casts of blood vessels permits detailed and accurate study of the microcirculation. The present study examined the renal microvasculature of the rainbow trout, Salmo gairdneri. The conventional picture of a glomerulus with one afferent arteriole was common, but glomeruli were often supplied by two afferent arterioles. In the majority of these, the intrarenal artery gave rise to a single afferent arteriole that branched to form two smaller vessels before reaching the glomerulus. Glomeruli with two afferent arterioles that arose independently from the intrarenal artery also occurred. The majority of glomeruli had a single efferent arteriole, but a proportion of glomeruli had two efferent arterioles. Efferent arterioles were smaller in diameter than the afferent arterioles. The glomerular capillaries were arranged in lobules, with few anastomoses between lobules, so that, for glomeruli with two afferent or two efferent arterioles, vascular perfusion and thus filtration within discrete lobules is probable.
Glycoconjugate distribution and mobility on apical membranes of absorptive cells of suckling rat ileum in vivo
Authors: Gonnella Patricia A. , Neutra Marian R.
Published: February 2005

The luminal membrane of ileal absorptive cells in suckling rats includes two domains: microvillar membranes and deep invaginations between microvilli. We examined the fates of foreign macromolecules that bind to anionic or saccharide sites on these domains after infusion into ligated loops in vivo. Cationized ferritin (CF) and ferritin‐RCAI (β‐galactosyl) binding sites were distributed over the entire apical membrane. Ligands bound to apical invaginations were rapidly endo cytosed, but ligands on microvilli were not. After CF binding, anionic sites on microvilli were mobile in the plane of the membrane and formed CF clusters at the tip and base of each microvillus. RCAI binding sites did not cluster. Wheat germ agglutinin (WGA, sialic acid) labeling was restricted to microvillus tips of mature cells but was dispersed over the microvillar surfaces of lower villus cells. Ferritin conjugates of Concanavalia ensiformis (Con A), Ulex europaeus agglutinin (UEA), and Dolichos biflorus agglutinin (DBA) did not bind to cell surfaces in vivo. Aldehyde fixation dramatically altered lectin binding patterns, resulting in unmasking and labeling of Con A, WGA, and DBA binding sites that were unavailable in vivo.
Anatomical relationships between type II pneumonocytes and alveolar septal gaps in the human lung
Authors: Takaro Timothy , Parra Saundra C. , Peduzzi Peter N.
Published: February 2005

This report describes a relationship between type II pneumonocytes and breaks in continuity in the alveolar septum of the human lung. Breaks in continuity of the septum are defined as gaps in the connective tissue matrix of the alveolar septum, with or without discontinuity of the accompanying alveolar epithelium. Septal connective tissue gaps accompanied by epithelial discontinuity are recognized as interalveolar pores of Kohn. When the discontinuity is confined to the connective tissue matrix, epithelial continuity may be maintained by either a single or a double layer of type I epithelium, by a type II cell, or by both type I and type II epithelial cells.

Alveolar septal gaps were studied by electron microscopy on random sections in 26 adult human lung specimens and by serially sectioning and montaging the entire circumference of one alveolus to a depth of 103 μm (approximately one‐half a normal alveolus) from one of the specimens. Fixation was by way of the airways in most specimens, but by vascular perfusion in the serially sectioned specimen and in seven others.

In lungs studied by random sections, we found that the incidence of septal connective tissue gaps with epithelial continuity per specimen correlated with the incidence of pores (r = .468, P < .016), and also with the incidence of type II cells (r = .422, P < .025) in the specimen. Five precent of all type II cells observed in the random sections in the 26 specimens (103/1,955) occupied septal gaps, and 2.5% (49/1,955) were located at the rim of a pore. In contrast, in the single serially sectioned montaged alveolus, 69% of all type II cells occupied some type of septal gap, with 24% of all type II cells forming part of the rim of a pore. Over half of all pores in this alveolus were associated with a type II cell.

We concluded that a relationship between the incidence of type II cells and gaps in the alveolar septum could be demonstrated on random sections in normal human lungs, which was much more obvious in a single serially sectioned hemialveolus. Serial section techniques of whole alveoli may be necessary to establish relationships that may not be apparent on random sections and that require the study of whole cells in continuity with their environment in order to be identified.

The findings may be significant in suggesting a possible role of the type II cell in alveolar septal repair.
Transient ultrastructural variations of pulmonary lymphatic capillaries during the respiratory cycle of the rat lung
Authors: Roberge Sylvie , Boucher Yves , Roy Paul‐Emile
Published: February 2005

The effect of respiratory movements on the endothelial wall of lung lymphatic capillaries was investigated by a morphometric study of their ultrastructure using a rodent model. The juxta‐alveolar lymphatic capillaries from lungs were fixed in the inflated phase by vascular perfusion with aldehydes and compared to those from lungs fixed in a deflated phase. Important quantitative differences in lymphatic endothelial wall architecture were observed between the two states. The most salient finding was a marked reduction of the mean endothelium thickness from 320 ± 55 nm in deflated lungs to 210 ± 36 nm (P<.01) in inflated lungs. The endothelial attenuation observed with inflated lungs was accompanied by a reduced frequency of interdigitation, the intricate pattern of intercellular contact (P<.02), and a decreased number of lumenal and ablumenal endothelial projections (P<.05). Despite these important variations in the dilated lymphatic capillaries, no typical open junctions (>30 nm) were found among 105 intercellular contacts. The vesicular system varied slightly after lung inflation. Dilated capillaries showed a significant reduction in cytoplasmic vesicles during inspiration (P<.01); however, the observed increases in lumenal and ablumenal vesicles were not found to be significant. As for numerical density and vesicular diameter, the fraction of cytoplasm occupied by the vesicles remains unchanged. Contrary to previous assumptions, these results suggest that intercellular clefts are not widened to the extent of open junctions (>30 nm) by the mechanical movement of inspiration in normal lungs. Moreover, transient changes to the endothelial architecture seem to preclude any excessive widening of the intercellular cleft.
A comparison of morphological stages and sulfated glycosaminoglycan production during otic capsule formation: In vivo and in vitro
Authors: McPhee Joseph R. , Van De Water Thomas R.
Published: February 2005

The sequence of events leading to otic capsule formation in the normal mouse embryo is described for both in vivo and in vitro development. Specimens were taken from embryos at 9–16 days of gestation. The in vivo results permitted the categorization of the developmental events of capsule formation into five distinct stages: prechondrogenic, aggregation, metachromatic, early chondrogenesis, and late chondrogenesis. Synthesis of sulfated glycosaminoglycans (S‐GAG) by early otic tissue complexes in vivo showed a sharp increase in the rate of S‐GAG production at 14.5 days of gestation (late chondrogenesis stage). The synthesis of S‐GAG in explants excised from embryos 12 days old (metachromatic stage) or older followed this same pattern of a sudden increase in S‐GAG synthesis at the in vitro equivalent of 14.5 days of gestation. These otic explants underwent all five stages of capsule formation up to the morphological equivalent of 16 days gestation. Therefore, otic explants can serve as a valid model in the study of those factors (i.e., tissue interactions and extracellular matrix) which influence and direct otic capsule formation.
Morphogenesis of human cardiac outflow
Authors: Thompson Robert P. , Sumida Hiroshi , Abercrombie Vant , Satow Yukio , Fitzharris Timothy P. , Okamoto Naomasa
Published: February 2005

The developmental anatomy of human cardiac outflow was studied in a series of 16 normal embryos (gestational days 29–39, crown‐rump length 6–20 mm, stages 14–19). Structural features and kinetics during truncal septation (TS) were described from external photographs, serial histological sections, and computer graphic reconstructions of selected tissues.

Early in the period studied, the tubular myocardium ensheathed the single cardiac lumen and spiralling conotruncal ridges, which were filled with mesenchymal cells during days 31–33. As TS began (late stage 16), the aorticopulmonary (AP) septum appeared across the dorsal wall of the aortic sac between arches IV and VI. Mesenchymal condensations formed within the AP septum, crossing the lumen bifurcation to extend along the truncal ridges to the myocardium. During days 35–37, the cephalic margin of the myocardium grew or folded in toward these mesenchymal condensations between the developing valves and within the nearby conal ridges, which appeared to fuse to separate the subvalvular outflow channels by day 39.

These observations are consistent with studies in chicks and rats which suggest that mesenchymal condensations or cell death foci interact with the distal myocardial rim during TS to form a structural septation complex dividing the two arterial streams.