bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gross anatomy of the respiratory system of the bowhead whale,Balaena mysticetus
Authors: Henry Robert W. , Haldiman Jerrold T. , Albert Thomas F. , Henk William G. , Abdelbaki Yahya Z. , Duffield Dennis W. 
Published: February 2005

AbstractComponents of the respiratory system from seven bowhead whales have been examined. The paired and laterally curved external nares are passively closed by a valve‐like mass located in the rostral, lateral, and ventral walls of the nasal vestibules. Nasal septal cartilages are paired smooth plates rostrally changing to accordion‐like folds caudally. The epiglottic and arytenoidal protuberances of the larynx are typically cetacean, but blunt. The cricoid cartilage is not a complete ring, but an elongated, inverted, troughshaped structure. The thyroid cartilage is trough‐shaped with elongated cranial cornua curving dorsocaudally from each thyroid lamina. A conical mass of skeletal muscle serves as the floor of the short trachea and also surrounds the termination of the laryngeal sac. The trachea is dorsoventrally compressed, lacks a tracheal bronchus, and its width equals its length. The principal bronchi give rise to lobar bronchi at obtuse angles. Large segmental bronchi branch extensively from lobar bronchi near the mediastinal lung surface. The lungs are rectangular and of nearly uniform thickness throughout, without external or internal lobulation.
The anatomy of the eustachian tube in the rat: A macro‐ and microscopical study
Authors: Albiin Nils , Hellström Sten , Salén Bengt , Stenfors Lars‐Eric , Söderberg Ove 
Published: February 2005

AbstractThe rat eustachian tube (ET), from the nasopharyngeal orifice to the tympanal orifice, is about 4.5 mm long, of which the naso‐medial membranous part (the nasopharyngeal orifice) measures about 1.5 mm and the occipito‐lateral bony portion about 3 mm. The nasopharyngeal orifice is surrounded by two soft, lip‐like, mucosal swellings—one ventral and one cranial—both easily mobile. The muscles related to the tubal opening mechanisms are the salpingopharygeus, the tensor veli palatini and the levator veli palatini muscles. The salpingopharyngeus muscle originates partly from the cranial lip, whereas the palatal muscles originate partly from the ventral lip. The tympanal two thirds of the mucosal lining of the ET is cranially guided by a cartilage and incompletely framed by bony structures. The tympanal orifice is situated in the nasal part of the medial wall, well above the floor of the bulla. The tensor tympani muscle does not seem to take part in the opening and closing mechanisms of the ET. The mucosal lining of the ET consists of a respiratory epithelium with numerous glands in the lamina propria. It is suggested that the tubal muscles control the passage through the ET by moving the lip‐like folds of the nasopharyngeal orifice. The anatomy of the rat ET is comparable to that described in Homo and it can be concluded that the rat ET might be a good model for studying the function of the human ET.
Observation of cytochemical alkaline phosphatase activity on the plasma membrane of cultured rat hepatocytes by backscattered electron imaging
Authors: Watanabe Jun , Kanamura Shinsuke , Asada‐Kubota Mari , Kanai Kazuo , Oka Motoko 
Published: February 2005

AbstractDistribution of alkaline phosphatase (ALPase) activity on the plasma membrane of rat hepatocytes in primary monolayer culture was observed using the backscattered electron image (BEI) mode. Apparent reaction product was seen in hepatocytes cultured for 48 or 72 hours in a concentration of 8 × 105 cells per ml, and those cultured for 72 or 96 hours in a concentration of 6 or 4 × 105 cells per ml. The reaction product was observed as scattered fine dots, as spots, and as bands along the cell edge, with high contrast in flattened polyhedral hepatocytes forming cell trabeculae. The deposition of the reaction product was generally more abundant at the periphery of the cell trabeculae. X‐ray microanalysis revealed that the reaction product contains both lead and phosphorus as real ALPase reaction product. In transmission electron microscopy, the reaction product was exclusively localized on the external surface of the plasma membrane. However, the plasma membrane adjoining the culture substratum was devoid of the reaction product. Further, the highest biochemical ALPase activity appeared in earlier culture stages when the density of cultured cells was larger. Thus, during a few days of culture, ALPase activity increases on the plasma membrane predominantly at the periphery of the hepatocyte trabeculae. This increase in the activity might be related to the mechanism of preserving the cell shape.
Three‐dimensional reconstruction from serial sections: II. A microcomputer‐based facility for rapid data collection
Authors: Sundsten John W. , Prothero John W. 
Published: February 2005

AbstractA microcomputer‐based facility is described that permits the data required for three‐dimensional reconstructions to be collected quickly and inexpensively from serial sections. The facility consists of a microcomputer, a digitizer tablet, a graphics terminal, a printer, a plotter, and telephone coupler. Images of serial sections are superimposed on the digitizer tablet. Contours of interest on each section are digitized and the coordinates are stored on “floppy” disks. The problems of putting successive sections in correct register and of taking into account magnification factors are discussed briefly. Use of the facility for high‐resolution applications is also considered.
Morphological identification of functional capillaries in the myocardium
Authors: Sage Martin D. , Gavin John B. 
Published: February 2005

AbstractThis study used acrylic resin as an intravascular marker to demonstrate functional myocardial capillaries after fixation by perfusion. Eight rat hearts were excised and allowed to function as isolated organs perfused with oxygenated Krebs‐Henseleit buffer (37o 10 kPa) for 10 min. Four were fixed by perfusion (4 min) with 2.5% glutaraldehyde at the same temperature and pressure and then immersion fixed (24 hr). The other four hearts were perfused with 0.2% procaine HCl for 30 sec just prior to similar fixation. Polymerizing low viscosity acrylic resin was injected at 10 kPa pressure into the fixed vascular beds and allowed to cure, then transmural blocks of left ventricular myocardium were prepared for scanning electron microscopy. Total initial coronary flow of fixative after procaine treatment was significantly increased, while in untreated hearts the initial fixative flow rate was closely similar to that of oxygenated buffer. The pattern of capillary perfusion was assessed, and the percentage of capillary profiles filled by acrylic resin were calculated. Following procaine treatment, 95.2% of capillaries appeared functional, whereas without procaine arrest, only 62.0% of capillaries allowed the passage of resin. This study indicates that perfusion fixation with glutaraldehyde stabilizes myocardial structure so that the proportion of functional capillary pathways remains closely similar to that in the beating heart and so that such functional capillaries can be identified in morphological preparations by using a low viscosity intraluminal resin marker.
Glycogen autophagosomes in polymorphonuclear leukocytes induced by rickettsiae
Authors: Rikihisa Yasuko 
Published: February 2005

AbstractGuinea pig polymorphonuclear leukocytes (PMNs), rich in glycogen granules, were collected from sodium‐caseinate‐induced eritoneal exudate. When these cells were incubated with rickettsiae, many microogranisms were phagocytized within 30 minutes at 35o C and vacuoles up to 5 μm in diameter containing glycogen granules were present. Contained within these vaculoes were phagocytized extracellular material and a dense, lysosomelike substance that was acid phosphatase positive. These vacuoles, which were interpreted to be autophagosomes, were absent from PMNs that had not been stimulated with microorganisms. The number of rickettsiae in the PMN did not appear to be related to the number of autophagosomes. About 8% and 80% of thin‐sectioned profiles of PMNs contained these vacuoles after 30 minutes and 4 hours incubation, respectively. After 4 hours, the PMNs contained multiple autophagosomes. Almost all of the glycogen granules were in autophagosomes in some of the cells. In some PMNs, discontinuous membranes encirlced some glycogen. When PMNs were initally incubated with thorium dioxide and ferritin, and extensively washed prior to incubation with rickettsiae, glycogen was found surrounded by flattened secondary lysosmes containing the dense tracers. Some autophagosomes also contained the electron‐dense tracers. These results suggest that rickettisae induce the rapid formation of glycogen‐containing autophagosomes in guinea pig peritoneal PMNs in vitro.
Migration of lymphocytes through the cutaneous basal lamina in normal skin: An ultrastructural study
Authors: Warfel K. A. , Hull Meredith T. 
Published: February 2005

AbstractIncubation of skin in 2 N sodium bromide allows separation of dermal and epidermal layers leaving an intact basal lamina covering the dermal portion. Examination of the surface of the dermis by SEM shows cells migrating through the basal lamina. By scanning and transmission electron microscopy, these cells have the characteristics of lymphocytes. The migrating lymphocytes produce a sequence of basal lamina deformations including dome formation, effacement of corrugations, and central fenestrations with hole formation allowing lymphocyte passage. Following passage there is reestablishment of a relatively smooth basal lamina in the crater base, effacement of the crater rim, and finally reformation of basal lamina corrugations. This deformability of the basal lamina supports the hypothesis that basal lamina is thixotropic. This study is the first demonstration in three dimensions of lymphocyte traffic across the basal lamina, an important component of skinassociated lymphoid tissue (SALT).
Histological and histochemical studies of the secretory components of the salamander olfactory mucosa: Effects of isoproterenol and olfactory nerve section
Authors: Getchell Marilyn L. , Rafols José A. , Getchell Thomas V. 
Published: February 2005

AbstractSecretory compoenets of the salamander olfactory mucosa, sustentacular cells (SC), and Bowman's glands (BG), were examined histologically and histochemically. In the aquatic larval salamander, SC in sensory grooves contained secretory granules; the submucosa contained a single layer of homogeneous, ductless glands. In the land‐dwelling adult salamander, SC spanning a flat epithelial sheet contained vesicles. Subjacent to the epithelium in both dorsal and ventral mucosae lay BG whose ducts opened at the surface of the epithelium. In the ventral mucosa, two additional layers of olfactory glands (OG) lying below the BG were identified; ducts were not observed in association with the OG. The β‐adrenergic agonist isoproterenol caused depletion of secretory granules from BG and OG of larval, young, and adult salamanders but had no discernible effect on SC. Histochemical techniques (Alcianblue at pH 2.5 and pH 1.0, high‐iron diamine, and the periodic acid‐Schiff reaction) demonstrated that SC contained neutral, acidic, and small amounts of sulfated mucopolysaccharides (MPS). BG and OG contained only neutral MPS. In contrast, glands under adjacent respiratory epithelium contained both acidic and sulfated MPS. Unilateral olfactory nerve section (ONX) caused changes in the histochemical reactivity of acidic and sulfated MPS in SC on the ipsilateral and later on the contralateral side. Neutral MPS staining became enhanced first in the OG that lay under the BG, then in BG cells, and later in the deepest OG layer. Ipsilateral changes preceded contralateral ones. At 24 days post‐ONX, some acinar cells in the deep OG contained acidic but not sulfated MPS.
Neural crest and normal development: A new perspective
Authors: Kirby Margaret L. , Bockman Dale E. 
Published: February 2005

AbstractSeveral clinical syndromes, including the DiGeorge syndrome, are characterized by clusters of developmental defects of the heart and great vessels with structures derived from the embryonic pharyngeal apparatus including thymus and parathyroids. The connective tissue derivatives of neural crest are necessary for the normal development of these structures, and there is new experimental evidence that depletion of neural crest causes defects similar to these clinical syndromes. Therefore it is proposed that many of these syndromes are due to inappropriate development of neural crest. The implications of this hypothesis include the predictions (1) that asplenia and certain other anomalies have the same etiology, and (2) that it is possible to observe the effects of teratogenic agents upon a cellular population (neural crest) at the time when it is being altered, rather than waiting until definitive organs may be examined.
Microanatomy of the major airway mucosa of the bowhead whale, Balaena mysticetus
Authors: Haldiman Jerrold T. , Henk William G. , Henry Robert W. , Albert Thomas F. , Abdelbaki Yahya Z. , Duffield Dennis W. 
Published: February 2005

AbstractIn the bowhead whale, Balaena mysticetus, the mucosa of the major airways from the blowholes through the rostral portion of the larynx is lined with parakeratotic, pigmented, stratified squamous epithelium. Scattered enlarged connective tissue papillae of the lamina propria of the nasal vestibules and the palatopharyngeal sphincter contain encapsulated nerve endings. Abundant papillae in the mucosa covering the epiglottic and arytenoid cartilages contain similar nerve endings. The remainder of the laryngeal cavity and laryngeal sac is lined by a variably pigmented, stratified squamous epithelium, which is not keratinized. At the laryngotracheal junction the lining changes to ciliated pseudostratified columnar epithelium which continues through the trachea and principal bronchi. Scanning electron microscopy (SEM) indicates that this epithelium is typically mammalian, with approximately half of the surface cells bearing cilia and slender microvilli. The remaining cells are mucus producing and have thicker microvilli. The valvular mass regulating the external nares consists of irregular, dense white fibrous connective tissue with numerous adipose cells and is penetrated by skeletal muscle cords ranging from 2–4 mm in diameter. The septal mass between the blowholes is composed of irregular, dense white fibrous connective tissue containing large tendinous bundles, clusters of adipose cells, and several large arteries and thick‐walled veins. The lamina propria of the nasal vestibules is irregular, dense white fibrous connective tissue. That of the larynx is not as dense and contains proportionately more elastic fibers. The laryngeal sac does not contain elastic laminae, but does have a tunica muscularis of skeletal muscle bundles. Within the trachea and principal bronchi, the lamina propria possesses laminae of longitudinally oriented elastic fibers and simple, branched tubuloalveolar mucous glands. The nasal, laryngeal, tracheal, and bronchial cartilages are hyaline with vascular channels.
Palatal analysis and osteology of the hard palate of the Kenyan African skulls
Authors: Hassanali Jameela , Mwaniki David 
Published: February 2005

AbstractOne hundred twenty‐five dry skulls from Kenya that consisted of about 90% Bantu individuals were examined to obtain data on the gross anatomy of the hard palate. The palatine index showed that 43.2% of the total sample of skulls has narrow (leptostaphyline), 23.7% intermediate (mesostaphyline), and 33.1% wide (brachystaphyline) palates. The palatine height index showed that 40% skulls had low (chamestaphyline), 57% intermediate (orthostaphyline), and 3.0% deep (hypsistaphyline) palates. Mean palatal length, breadth, and height for the total sample was 4.92 cm, 4.02 cm, and 1.22 cm, respectively. The incisive foramen and canal was cone shaped in 80% where the diameter of the foramen was less than 0.4 cm, while it was cylindrical in 20% where the diameter was greater than 0.4 cm. Forty‐nine per cent of the skulls had two—five lesser palatine foramina present. The greater palatine foramen was found to lie at the level of the third molar in 76%, intermediate between second and third molars in 13.6%, and opposite the second molar in 10.4%. The greater palatine foramen opened antero‐medially in 74% and perpendicularly in 26% of the palates. Extensive longitudinal palatal grooves were found bilaterally in all the palates, 70% showed divisions of the grooves, 63.2% had crests along the border of the grooves, and 19.2% had bridges in the posterior part of the groove near the opening of the greater palatine foramen. The incidence of palatine torus was 4.8%. The incisive suture was present in 6.4% of the adult palates.
Branched myofibers in long‐term whole muscle transplants: A quantitative study
Authors: Bourke Dianna L. , Ontell Marcia 
Published: February 2005

AbstractOrthotopic transplants of whole extensor digitorum longus muscles were performed on six 4–6‐week‐old 129 ReJ mice. One hundred days posttransplantation, the animals were killed and the regenerated muscles were processed for electron microscopy. The grafts contained polygonal‐shaped myofibers with persistent central nuclei, organized into discrete muscle fascicles. No central area of fatty infiltration or fibrosis was observed. The mean number of myofibers in a regenerating transplanted muscle, as determined from an ultrathin section taken from the graft's widest girth, was 631 (SEM = ± 59), a reduction of ∼ 32% from that found in age‐matched control muscle (Ontell et al., 1983). By following the myofibers in spaced, serial ultrathin sections along their length, it was found that the branched, regenerating myofibers found in immature grafts of normal muscle (Ontell et al., 1982) persisted in stabilized, long‐term transplanted muscle. The frequency of branching was determined by following each fiber found at the widest girths of four of the grafts in spaced, serial ultrathin sections (15‐μm intervals) for ∼2% of the total length of the grafts. Over this distance, 6.6% of the fibers were involved in the branching phenomenon. The persistence of branched fibers in long‐term grafts and the frequency with which the branching phenomenon was found to occur may have physiological consequences and should be investigated.
Identification of Leydig‐like cells in the testis of the dogfish Squalus acanthias
Authors: Pudney Jeffrey , Callard Gloria V. 
Published: February 2005

AbstractThe site of hormone synthesis in the testis of elasmobranchs has been the subject of much controversy. This is primarily due to the problem of whether Leydig cells are present or absent in the testes of many species of elasmobranchs. In previous studies we have shown that key enzymes associated with the biosynthesis of androgen increase in activity during the spermatogenetic cycle of Squalus acanthias (Canick et al., 1983). To determine the site of this activity we undertook an electron microscope study of Squalus testes to identify cells that possessed the structural correlates of steroid production. This report describes cells present in the interstitial tissue that are morphologically analogous to Leydig cells occurring in the testes of higher vertebrates. Although these cells possessed an agranular reticulum, tubulovesicular mitochondria, and lipid droplets, they were mesenchymal in appearance. We have, therefore, preferred to describe these cells as Leydig‐like.
Use of the peroxidase‐antiperoxidase technique for differential staining of multiple cell types in the rat pancreatic islet
Authors: DeLeo Joyce A. , Schweisthal Michael R. 
Published: February 2005

AbstractMultiple staining of the endocrine cells of the pancreatic islet was studied in tissue obtained from adult rats. After fixation in Bouin's fluid and processing for light microscopy, the unlabeled peroxidase‐antiperoxidase (PAP) technique was performed. Successful staining procedures used variations of the PAP technique with 3,3′‐diaminobenzidine (DAB) and 4‐chloro‐1‐naphthol (CN) as chromagens. The purpose of this study was to stain as many of the four primary cell types (A‐cells, B‐cells, D‐cells, PP‐cells) as possible either simultaneously or sequentially using photomicroscopy. At optimum antibody titer, there was minimal nonspecific background staining which made it possible to differentiate cell types by intensity of the chromagen. Any two cell types can be shown by using DAB with the first antibody and CN with the second. To demonstrate three cell types simultaneously, three methods which altered dilutions and chromagens were used. The first method consisted of decreasing dilutions of primary antibody with DAB and CN as the chromagens. The second method involved repetitive DAB applications resulting in three intensities of brown. The third method used a DAB immersion after the second cell type was stained. This produced a color differential so the third cell type could be distinguished with CN. To demonstrate the three cell types sequentially, a masking technique was introduced with photomicroscopy. In order to block the preceding complex, the previous cell type (demonstrated by CN) was restained with DAB at an increased dilution. The next cell type was then stained with CN. These four methods were tried in attempts to stain four cell types in the same tissue section.
Movement of ferritin in the 2‐day‐old chick femur
Authors: Dillaman Richard M. 
Published: February 2005

AbstractThe distribution of intravascularly administered ferritin was examined in histological sections of femurs from 2‐day‐old chicks. The ferritin was seen in the mineralized portion of the bone as well as in the vessels 5 minutes after injection into the external jugular vein but was essentially absent 4 hours after injection. The concentration of ferritin in the vessels appeared to increase from the endosteal to the periosteal surface. In the mineral the ferritin appeared to move as a front roughly parallel and distal to the canals. A scheme for the movement of fluid and associated material through the mineralized portion of chick bone is presented that suggests that the driving force for the bone fluid is attributable to pressure differentials between adjacent canals. This differential is due to the geometry of the canals and increases as the angle of the canal relative to the endosteal surface decreases.
Tracheobronchial epithelium of the sheep: II. Ultrastructural and morphometric analysis of the epithelial secretory cell types
Authors: Mariassy Andrew T. , Plopper Charles G. 
Published: February 2005

AbstractIn a light microscopic study we have described the morphology and distribution of six distinct, granule‐containing cells in the tracheobronchial epithelium of sheep lung. We designed the present study to determine qualitatively and quantitatively whether these six cell types differ in ultrastructural morphology. Cell height varied from 30.6 μm for mucous cell M1 to 9.6 μm for Clara cells. Cell width varied from 21.2 μm for M1 to 9.3 μm for Clara cells. Nuclear dimensions ranged from 7.5 μm in M3 to 4.0 μm in M1 and M2. Mucous cell M1 had electron‐dense granules (1.5 μm in diameter); M2, electron‐lucent granules (1.6 μm); M3, nucleated electron‐lucent granules (0.51 μm); M4, cored granules (1.1 μm); serous (SC) and Clara cells (CC), electronopaque granules (0.58 μm and 0.37 μm). The volume fraction of the cell occupied by granules was 63% in M1 and M2, M4 39%, SC 23%, CC 5%, and M3 4.5%. Smooth endoplasmic reticulum was observed only in M3 (33.8%) and CC (49%). Granular endoplasmic reticulum (GER) was most abundant in SC (21%) and least plentiful in M4 (2.2%). We conclude that mucous cells M3 and M4 and serous and Clara cells differ from each other and from M1 and M2 cells. Mucous cells M1 and M2 differ from each other only in amount of GER and secretory granule appearance.