bluuebunny/crossref_metadata_2025 huggingface dataset:
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

The 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

Distribution 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

A 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

This 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

Guinea 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

Incubation 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

Secretory 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

Several 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

In 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

One 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

Orthotopic 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

The 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

Multiple 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

The 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

In 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.
Epithelial fusion during early semicircular canal formation in the embryonic zebrafish, Brachydanio rerio
Authors: Waterman Robert Earle , Bell Danny H.
Published: February 2005

The developing inner ear of the teleost, Brachydanio rerio, provides an opportunity for observing an epithelial fusion between the apical surfaces of apposed epithelia in a vertebrate embryo in vivo. The developing otocyst was filmed for periods up to 4 days in unanesthetized embryos, and specimens were fixed at intervals and processed for light microscopy, TEM and SEM. The semicircular canals are formed as a consequence of the union between the tips of three cylindrical projections from the wall of the otocyst, which grow toward corresponding bulges of a projection from the lateral wall. The epithelial cells covering the projections contain extensive rough endopasmic reticulum, exhibit apical junctional complexes, and are not underlain by a basal lamina. The core of each projection contains large amounts of flocculent and fibrillar extracellular material. After a period of growth and elongation, the tip of each projection contacts, and adheres to, the appropriate bulge to create a circular, flattened, bilayered, epithelial plate. Small, focal junctions form between the apposed apical cell surfaces within the plate during this period, but they are not numerous. Junctional complexes do develop, however, between apposed cells at the periphery of the plate. After 1–2 hours, the basal surfaces of the plate exhibit considerable alteration in contour. Adjacent cells within the plate then separate to allow continuity of the connective tissue components of the two structures. The observations of this study indicate that following an initial period of contact and adhesion, cellular reorientation and changes in junctional contacts between adjacent cells within the epithelial plate, rather than cell degeneration, are responsible for perforation of the plate.
A comparison of rat and hamster preovulatory follicles: An examination of differences in morphology and enzyme activity using qualitative and quantitative analyses
Authors: Zoller Lawrence C.
Published: February 2005

The structure and enzymatic content of rat and hamster preovulatory follicles were examined using morphologic, qualitative, and quantitative cytochemical techniques. Interfollicular structure in both types was similar but lipid droplet distribution differed. The rat theca contained many more droplets than the hamster, while the hamster membrana granulosa contained more droplets than the rat. δ5‐3β‐hydroxysteroid dehydrogenase (3βOHD) activity and glucose‐6‐phosphate dehydrogenase (G‐6‐PD) Types IH and IIH generation were measured using quantitative cytochemistry. Rat theca and granulosa contained more 3βOHD activity than found in comparable regions in hamster. G‐6‐PD Type IH and Type IIH generation were the same in comparable regions of rat and hamster, but in rat there was more Type IIH than IH, while the converse existed in hamster. These differences and their relationship to follicular steroid production are discussed.
Diameter and length changes in cerebral collaterals after middle cerebral artery occlusion in the young rat
Authors: Coyle Peter
Published: February 2005

Rapid occlusion of the middle cerebral artery (MCA) in the 36‐day‐old normal Wistar rat results in change of the dorsal collaterals joining branches of the anterior and middle cerebral arteries. As compared to similarly positioned vessels on the opposite hemisphere and arterioles in unoperated rats of 56 days, of age, there were significantly (P < 0.001) more large (60–120 μm)diameter collaterals on the occluded side 20 days after MCA occlusion. There were fewer small (0‐59μm) diameter collaterals on the occluded side as compared to unoperated rats. The data suggest small diameter arterioles existing at occlusion became large diameter collaterals. The mean number of collaterals per hemisphere was not significantly different (P > 0.05) between occluded and unoperated rats. There was no evidence that new vessels were added during the 20‐day ligation period. The mean collateral tortuosity value was significantly (P < 0.01) greater for large diameter vessels on the right occluded side as compared to vessels on the left hemisphere or vessels in unoperated age‐matched control rats. The greater tortuosity values of vessels on the occluded side were evidence that collateral vessel length was increased by 24–29% after MCA occlusion. Speculation was made about possible mechanisms responsible for these vascular changes.
The radioscapholunate ligament: A gross and histologic description
Authors: Berger Richard A. , Blair William F.
Published: February 2005

The anatomic relationships of the carpal radioscapholunate ligament to its contiguous structures were analyzed by studying (1) 12 grossly dissected fresh adult wrists, and (2) multiple histologic sections from six adult wrists. Observations indicate that the radioscapholunate ligament originates from the prominence between the scaphoid and lunate articular facets on the distal articular surface of the radius, and from the palmar margin of the distal radius, deep and medial to the origin of the radiotriquetral and radiocapitate ligaments. The primary insertion of the radioscapholunate ligament is the medial margin of the proximal pole of the scaphoid. The ligament secondarily inserts into the lateral margin of the lunate and significantly contributes to the proximal portion of the scapholunate interosseous ligament. The radioscapholunate ligament is distinguished morphologically from the other palmar radiocarpal ligaments by its loosely organized collagen fibers and relatively high degree of vascularity. The radiotriquetral and radiocapitate ligaments are composed of densely fasciculated collagen fibers surrounded by perpendicularly oriented perifascicular and epiligamentous fibers. A fibrous capsular layer covers the most superficial aspect of each carpal ligament. On the deep surfaces of these ligaments, a condensation of epiligamentous fibers forms a synovial capsular layer. The palmar radiocarpal ligaments are truly intracapsular structures, as they are interposed between the fibrous and synovial capsular layers. No histologic evidence of elastin is present within the substance of these ligaments.
The mononuclear phagocyte system of the mouse defined by immunohistochemical localisation of antigen F4/80: Macrophages associated with epithelia
Authors: Hume David A. , Perry V. Hugh , Gordon Siamon
Published: February 2005

The tissue distribution of the murine macrophage‐specific antigen F4/80 has been analysed using an immunohistochemical technique. The antigen is observed on all known macrophage populations (including Kupffer cells and bronchoalveolar macrophages) and is absent from any cell types that are definitely not mononuclear phagocytes. Microglial cells from brain express F4/80. F4/80+ macrophages observed associated with epithelia can be divided into two categories, intraepithelial and periepithelial. The former includes epidermal Langerhans cells and cells with similar morphology in other stratified squamous epithelia (cervix, oesophagus), pseudostratified epithelium (trachea), transitional epithelium of urinary bladder, and simple epithelia lining various ducts (salivary gland, common bile duct, tracheobronchial gland). Periepithelial F4/80+ cells, apparently spread immediately below the basal lamina, are associated with simple epithelia throughout the gastrointestinal, respiratory, and male and female reproductive tract as well as the brain ependyma. A major class of periepithelial F4/80+ cells is associated with capillaries throughout the microcirulation. The role of these macrophage populations in control of epithelial function is discussed.
The effects of pelvic neurectomy on collagen in the cervix of the pseudopregnant rat
Authors: Burden Hubert W. , Leonard Marilyn , Smith Carlton P. , Louis Thomas M. , Lawrence Irvin E.
Published: February 2005

Bilateral section of the pelvic parasympathetic nerves (pelvicneurectomy) on day 5 of pseudopregnancy had no effect on the wet weight of ovaries, uteri, and/or cervices, but at day 9 serum progesterone was reduced to approximately half that of sham‐operated animals. Collagen in the cervix was visualized with picrosirius red staining under polarization microscopy. Pelvic neurectomy decreased the birefringence of Type 1 collagen in the cervix to less than half that of sham operated animals. The decreased birefringence, an index of the organization of collagen fibers, is believed to be attributable to reduced progesterone levels. Alternatively, the pelvic nerve may directly influence mucopolysaccharides or collagenolytic enzymes in the cervix.
Immunohistological demonstration of S‐100 protein in the cutaneous nervous system
Authors: Hachisuka Hiroshi , Mori Osamu , Sakamoto Fumino , Sasai Yoichiro , Nomura Hirofumi
Published: February 2005

S‐100 protein, isolated from mammalian brain, has widely been used for immunohistochemical marker of the glia cells and the cells derived from the neural crest. In the present study, we made anti S‐100 protein antibody and studied the immunoreactive distribution of S‐100 protein in the cutaneous nervous system. Albino rabbits were immunized with S‐100 protein and complete Freund adjuvant, and antiserum was purified by ion‐exchange chromatography. Formalin‐fixed normal human skin and sciatic nerve of rat were examined by the PAP method. S‐100 protein was detected in Schwann cells of sciatic nerve of rat and cutaneous nerve bundles of human skin specimens. Meissner corpuscles and inner core cells of Pacinian corpuscles of human skin were S‐100 protein positive. These findings suggest that the staining of S‐100 protein with PAP method is a simple and reliable method to demonstrate the cutaneous nervous system. Also, lamellar cells of Meissner corpuscles and inner core cells of Pacinian corpuscles are indicated to be Schwann cell origin.
Intranuclear inclusions in rat piriform cortex: Increase with age and preferential location within superficial layer II
Authors: Curcio Christine A. , McNelly Nancy A. , Hinds James W.
Published: February 2005

Intranuclear inclusions have been observed in layer II neurons of rat piriform cortex. These inclusions have the form of a filamentous lattice and resemble those described by others previously. The frequency of lattice‐containing nuclei shows a significant fourfold increase over a period of 3–33 months of age, with the largest increase occurring after 18 months. The incidence of these inclusions is highest in the superficial third of layer II and is significantly greater than what would be expected from the distribution of all neuronal nuclei in layer II. The presence of intranuclear lattices may be related to the high level of electrical activity in piriform cortex, and their increase with age may reflect a long‐term cumulative effect of this activity.
The effect of adriamycin on rat incisor one day after administration
Authors: Karim A. C.
Published: February 2005

The effect of adriamycin on rat incisor was investigated 1 day after administration. Rats were injected intravenously with adriamycin at a dose of 5 mg/kg body weight and sacrificed by perfusion with a 2.5% phosphate buffered glutaraldehyde solution. The principal effect of the drug on the incisor was the production of cell degeneration. This was extensive in the apical region, being present along the entire periphery of the dental papilla. In sections examined more incisally, cell degeneration gradually disappeared from the labial portion of the incisor but was present in the lingual portion. This degeneration of cells was not present at the site where mature odontoblasts had differentiated on the lingual surface of the pulp chamber. It appears that the affected cells were early preodontoblasts and the precursors of preodontoblasts. However, as these cells became more differentiated they apparently became more resistant to the drug's effect.
A practical method for staging metamorphosis in the tiger salamander Ambystoma tigrinum
Authors: Norman Mark F.
Published: February 2005

The aim of this study was to develop a set of practical metamorphic stages for the tiger salamander Ambystoma tigrinum that would (1) provide an early and quantifiable marker of the onset of metamorphosis and (2) not be dependent on knowledge of maximal values of gill length or tail height. Twenty morphological parameters were obtained from Ambystoma tigrinum larvae as they progressed through laboratory‐induced metamorphosis (21°C, continuous light). These parameters included measures of body weight, gill length, and tail height. Initiation or duration of metamorphosis could not be predicted when parameters were expressed relative to the number of days larvae were held in laboratory conditions.

Early phases of metamorphosis were characterized by regression of the lower tail fin. Selected morphological parameters were expressed relative to the day on which each subject exhibited complete regression of the lower fin. This technique made it possible to order these parameters into a progressive series of metamorphic phases. Seven stages of metamorphosis were derived from this series, ranging from larvae (stage I) to complete regression of the gills (stage VII). Application of these stages does not require prior knowledge of maximal (initial) values of gill length or tail height.
The cellular distribution of calcium in freeze‐dried rabbit vas deferens using em autoradiography
Authors: McGuffee Linda J. , Wheeler‐Clark Ellyn S. , Skipper Betty J. , Little Sally A.
Published: February 2005

The role of calcium in initiating smooth muscle contraction is widely accepted. The sources of this calcium are thought to be located both intracellularly and extracellularly. We have recently developed a method by which the cellular localization of calcium in smooth muscle can be determined. This method involves exposing the tissue to 45Ca, rapidly freezing and vacuum dehydrating the tissue, and preparing the tissue for electron microscopic autoradiography (EM ARG). In the present study the distribution of calcium in control and potassium‐contracted tissue of the rabbit vas deferens was compared. No significant differences in distribution were observed in the two treatments. This finding provides morphological support for the hypothesis that the calcium used in potassium‐induced contraction is primarily of extracellular origin. In addition, significant sequestration by intracellular organelles does not occur during a potassium contraction. In other experiments, the effect of rinsing tissue in cold calcium prior to freezing was investigated. From these data is appears that calcium is removed from the cytoplasmic matrix, plasma membrane, and organelles in a nonuniform manner. Further investigation into these findings should enable us to characterize more precisely the intracellular redistribution of calcium that occurs as a result of a variety of physiological manipulations.
Scanning electron microscopic observations of casts of human dentinal tubules along the interface between primary and secondary dentine
Authors: Wang Yien Nan , Ashrafi Shahid H. , Weber Dennis F.
Published: February 2005

A scanning electron microscope cast technique was used to examine the interface between primary and secondary dentine in young and old human teeth. In addition, more traditional methods were used to examine this interface with light microscopy, identical regions being viewed before and after demineralization. No continuity was seen between the tubules in primary dentine and those in irregular secondary dentine in the scanning electron microscope preparations. These preparations did show the tubules to be continuous between primary dentine and regular secondary dentine in young and old teeth. Both the scanning electron microscopic and light microscopic observations suggested that regular secondary dentine becomes highly sclerosed in old teeth.
Pit cells in extrahepatic organs of the rat
Authors: Kaneda Kenji , Wake Kenjiro
Published: February 2005

Electron microscopic examination of the extrahepatic distribution of pit cells, a cell type found in the liver, revealed their existence in several other organs of the rat. They were (1) relatively frequent in lungs, spleen (red pulp), small intestine, epididymis, trachea, and peripheral blood; (2) much fewer in bone marrow and thymus (medulla); and (3) nonexistent in lymph nodes, spleen (white pulp), and thymus (cortex). The pit cells in these organs, as well as in the liver, contained characteristic dense granules and rod‐cored vesicles in the cytoplasm. Our observations suggest that pit cells circulating in the peripheral blood adhere to the endothelium of capillaries in the various organs and migrate into the tissue, where they have some special immunological function.
Matrix compartments in the growth plate of the proximal tibia of rats
Authors: Eggli Peter S. , Herrmann Wolfgang , Hunziker Ernst B. , Schenk Robert K.
Published: February 2005

The cartilaginous matrix in the growth plate of the proximal tibia of rats is subdivided into various compartments according to criteria established by electron microscopic examination. In conventionally fixed specimens, the arrangement of collagen fibrils was analyzed by transmission and scanning electron microscopy. Distribution of proteoglycans and relations between matrix and cells were studied after fixation in media containing cationic dyes. Matrix compartments are best characterized by the density and arrangement of their collagen fibrils. On the other hand, proteoglycans are distributed almost homogenously all over the matrix. Each chondrocyte is surrounded by a thin envelope of proteoglycans, the pericellular matrix. Adjacent to this is a layer dominated by the content and order of its collagen fibrils, the territorial matrix. Its inner part covers the pericellular matrix with a thin net of intersecting fibrils. The outer part unites the cells of each column by a sheath of tightly packed longitudinal fibrils. This distinction is only possible in the longitudinal parts of the territorial matrix, whereas in the transverse septa both layers fuse into a common network. The interterritorial matrix is interposed between the columnar units and thus represents the central part of the longitudinal septa. Mineralization is restricted to the interterritorial matrix and matrix vesicles are coincidentally found in the same compartment. During growth, this structural organization undergoes a permanent and relatively fast remodeling, a process that is discussed in view of possible cell matrix interactions.
Progenitor cell populations in the periodontal ligament of mice
Authors: McCulloch C. A. G.
Published: February 2005

Stem cells in a variety of renewal tissues exhibit a slow rate of cell proliferation (Potten et al., 1979). The periodontal ligament of mouse molars was examined for the presence of slowly cycling progenitor cells to provide evidence for the existence of stem cells in this tissue. A pulse injection of 3H‐thymidine was administered and mice were sacrificed between 1 hour and 14 days after injection. Analysis of radioautographs using percentage of labeled cells and grain counts demonstrated that a population of label‐retaining cells within 10 μm of blood vessels traversed the cell cycle more slowly than proliferating cells located greater than 10 μm from blood vessels. These data suggest that there is a slowly dividing population of progenitor cells in paravascular sites in mouse molar periodontal ligament which may be stem cells.
Constant position of the superficial cerebral veins of the rat: A quantitative analysis
Authors: Bardosi Attila , Ambach Georg
Published: February 2005

The normal anatomical position of the point of junction of the superficial cerebral veins with the superior sagittal and transverse sinuses of the rat was studied with an analytical mathematical method. There were eight fixed veins, each characterized by a constant point of juncture having minimal variance. The findings indicate that the points of juncture between large veins and sinuses are developmentally fixed and that there is a definite order in the number and the territories of the large veins.
Fiber type composition of monkey forearm muscle
Authors: McIntosh Joan S. , Ringqvist Margareta , Schmidt Edward M.
Published: February 2005

Histochemical staining methods were applied to selected superficial forearm muscles of Macaca mulatta monkeys. The muscles were analyzed with regard to relative percentage distribution of different fiber types. In extensor carpi radialis brevis, extensor carpi radialis longus, and palmaris longus there was an even dispersion of each fiber type from the superficial to the deep part of the muscle. Extensor digiti communis showed a slightly higher percentage of type I fibers and correspondingly lower percentage of type II fibers in its central as compared to its superficial area. Three muscles, bracioradialis, extensor carpi ulnaris, and flexor carpi radialis, displayed marked differences between their superficial and deep areas. All of them contained a higher proportion of type I fibers (and correspondingly lower percentage of type II fibers) in their deep parts than in their superficial areas.

Flexor carpi ulnaris (FCU) differed from the other muscles studied in that it showed distinctly different fiber proportions on either side of a central tendon. While the ulnar head of FCU was dominated by type II fibers (71% compared to 27% type I fibers), the humeral head contained a larger proportion of type I fibers (58% vs. 40% type II fibers). This difference in fiber type distribution suggests different functional demands for the two heads of FCU, with the possibility of more sustained activity in the humeral head.
Diabetes‐associated alterations in uterine structure in the C57BL/KsJ Mouse: Relationship to changes in estradiol accumulation, circulating ovarian steroid levels, and age
Authors: Garris David R.
Published: February 2005

The effects of the diabetes (D) mutation on utero‐ovarian structure and function were examined in match‐paired D and control (C) C57BL/KsJ mice between 2 and 16 weeks of age. Between 4 and 8 weeks of age, the uterine epithelium of D mice exhibited a remarkable increase in the amount of cytoplasmic lipid stores as compared with that of C animals. Associated with progressive hyperglycemia between 8 and 16 weeks of age, uterine atrophy and continued lipid accumulation occurred. Both serum progesterone and estradiol levels were lower in D than C mice between 8 and 16 weeks of age. In addition, the uteri of D mice failed to accumulate as much 3H‐estradiol as C uteri at 16 weeks of age. These data demonstrate that changes in uterine structure that are attributable to depressed ovarian activity in diabetics underlie the reproductive failure in these animals. The temporal association between the onset of reproductive tract involution and the expressed hyperglycemic condition suggests a causal association between these events in the genetically diabetic C57BL/KsJ mouse.
Whole population cell kinetics and postnatal development of the mouse intestinal epithelium
Authors: Cheng Hazel , Bjerknes Matthew
Published: February 2005

Measurements of whole population cell kinetics of mouse intestinal epithelium during postnatal development are reported. Swiss albino mice aged 1, 2, 3, 4, 6, 8, 10, 12, 16, 19, 24, and 28 weeks were studied. Isolated epithelial preparations of jejunum and colon were used. Most kinetic parameters studied either increased or decreased with age to reach a steady level sometime after weaning. For example, before weaning about 30% of crypts were observed to be branching, while after weaning, the population of crypts that were branching decreased to adult levels of 5–10% in jejunum and 1–2% in colon. Thus, there was very active crypt formation before weaning, which likely continued into adult life but at a lower level. Villus formation appeared to be occurring in animals before weaning (i.e., 1–3 weeks), while it stopped with weaning, and thus the mean villus height increased to a plateau, which was constant with age after 4 weeks. In contrast, the mean villus width increased steadily with age. As the width of villi increased with age, the number of crypts assoiated with a villus also increased (presumably as a result of net crypt production in the adult). These measurements and many others (proportion of cells in S phase, number of cells/cm2, number of cells/villus, number of cells/crypt, etc.) are described.