bluuebunny/crossref_metadata_2025_split huggingface dataset:
Early morphological alterations of pressure‐overloaded cat right ventricular myocardium
Authors: Marino Thomas A. , Houser Steven R. , Cooper George 
Published: February 2005

AbstractPressure overload of the right ventricle results in an increase in ventricular mass. It also results in abnormal in vitro contractile function in advance of the onset of congestive heart failure as determined in papillary muscles removed from these ventricles. To correlate these functional abnormalities with any early underlying morphological changes, a band was placed around the proximal pulmonary artery of cats. This band restricted the lumen to 20% of normal and was left in place for 2 weeks. At that time, hemodynamic variables were measured to insure that right ventricular pressure overload had been produced. The hearts were then perfusion fixed, and papillary muscles from the right ventricle were prepared for light and transmission electron microscopy. Quantitative morphological data were obtained for the volume density both of several tissue components and of several organelles. It was found that there are significant increases in myocyte cross‐sectional area and diameter in hypertrophied tissue with a concurrent increase in the volume density of interstitial tissue. There are no alterations in the volume density of organelles in the hypertrophied myocytes. We suggest that the substantial increase in the proportion of connective tissue and the decrease in the surface area to volume ratio that accompany pressure overload cardiac hypertrophy may be early underlying structural changes that relate directly to the abnormal contractile function found in this type of hypertrophy.
Ultrastructural distribution of sulfated complex carbohydrates in elastic cartilage of the young rabbit
Authors: Takagi Minoru , Parmley Richard T. , Denys Francis R. , Kageyama Masato , Yagasaki Hiroshi 
Published: February 2005

AbstractSulfated glycosaminoglycans are an integral component of elastic cartilage. We have investigated the ultrastructural distribution of sulfated complex carbohydrates (CC)in the mature cartilage and the perichondrium of young rabbit auricles using the high iron diamine‐thiocarbohydrazide‐silver proteinate (HID‐TCH‐SP) and the tannic acid‐ferric chloride (TA‐Fe) methods. In the mature cartilage, HID‐TCH‐SP stained intracellular Golgi saccules of the mature face, secretory granules, and the extracellular matrix granules, but staining was not discernible in collagen fibrils and osmiophilic elastic fibers consisting of only amorphous elastin. The HID and TA‐Fe staining were similarly observed in matrix granules, whereas the elastic fibers and collagen fibrils lacked the staining. The pericellular matrix granules had a diameter of 34 ± 5 nm (mean ± SD; n = 30). Thiéry's periodate‐TCH‐SP (PA‐TCH‐SP) method stained vicinal glycol‐containing CC in collagen fibrils but failed to stain matrix granules and elastic fibers. In the perichondrium, HID‐TCH‐SP staining of the organelles was less intense in the flattened chondrocytes when compared with those in large mature chondrocytes. The extracellular HID and HID‐TCH‐SP staining were observed in the matrix granules. The diameter of pericellular matrix granules (19 ± 4 nm, mean ± SD; n = 30) was significantly smaller when compared to those in the mature cartilage (P < 0.001). The HID‐TCH‐SP staining was closely associated with collagen fibrils. However, the staining was not seen in collagen fibrils and osmiophilic elastic fibers consisting of elastin and microfibrils. The PA‐TCH‐SP method stained collagen fibrils and microfibrils but did not stain the amorphous elastin. Thus these studies demonstrate that sulfated CC are packaged in chondrocyte secretory granules and are released into the extracellular matrix to form matrix granules, but are not incorporated into collagen fibrils and elastic fibers.
The effect of alloxan, and alloxan‐induced diabetes on the kidney
Authors: Evan Andrew P. , Mong Stephen A. , Connors Bret A. , Aronoff George R. , Luft Friedrich C. 
Published: February 2005

AbstractAlloxan is known to induce diabetic renal changes as well as causing nephrotoxic alterations. However, no ultrastructural study has been performed to differentiate diabetic verses toxic affects of alloxan to the tubule and/or glomerulus. Therefore the present study used the “protected” kidney model to prevent one kidney from being exposed to the alloxan while allowing the other to receive the drug immediately. In all experimental animals the right renal hilum was gently occluded for 5 minutes and then released. This was performed prior to the injection of alloxan. Subsequently, the left renal hilum was occluded at the time of, and for 5 minutes after, alloxan administration (40 mg/kg i.v.). The experimental rats were divided into three groups: untreated diabetics, diabetics treated with protamine‐zinc‐insulin, and alloxantreated rats that failed to become diabetic. Three groups of controls were included: one group received an equal volume of saline diluent as the experimental rats but no clamping of either renal hilum; another group received the saline and had the left renal hilum occluded for 5 minutes; and a third group had both the right and left renal hila occluded. All animals were followed and sacrificed after 9 weeks. Endogenous creatinine clearance did not change among groups. Alloxan‐treated nondiabetic rats displayed marked interstitial nephritis in unprotected kidneys, while protected kidneys were normal. The diabetic state resulted in mesangial proliferation and focal glomerular basement membrane thickening as well as glomerular capilary endothelial abnormalities and visceral epithelial foot‐process fusion. The endothelial changes consisted of focal areas showing a reduction in the size of endothelial fenestrae. All glomerular changes were ameliorated by insulin treatment. We conclude: (1) alloxan per se is distinctly nephrotoxic; and (2) the glomerular endothelium and epithelium are involved early in the course of experimental diabetes.
Evidence of sequential remodeling in rat trabecular bone: Morphology, dynamic histomorphometry, and changes during skeletal maturation
Authors: Baron Roland , Tross Robert , Vignery Agnes 
Published: February 2005

AbstractThe occurrence of a sequential bone remodeling activity, similar to what is observed in human bone, is demonstrated in rat trabecular bone at the level of the secondary spongiosa. A complete dynamic histomorphometric analysis of the remodeling activity, using undecalcified sections and double fluorescent labels, has consequently been performed in young adults (220 g, 8 weeks old) and in more mature animals (320 g, 12 weeks old). The results showed that, despite a similar trabecular bone volume, younger animals had a five times higher bone formation rate and five times more osteoclasts than more mature animals. The higher bone formation rate was due in part to a threefold higher extent of double‐labeled trabecular bone surface and in part to a 1.5‐fold faster mineralization rate. These results therefore demonstrate a marked slowing down of bone turnover during skeletal maturation in the rat. The values obtained in this study have been compared with measurements made in other parts of the skeleton in the same species (Vignery and Baron 1978, 1980b; Tran Van et al., 1982a) or in humans. This comparison indicated that 12‐week‐old rats had a turnover rate very similar to values observed in iliac crest trabecular bone in adult humans. The rat is therefore a good experimental animal for the study of trabecular bone remodeling but since large variations occur during skeletal maturation, care should be taken in the selection of an age group relevant to the type of questions being asked.
Ultrastructural cytochemistry of proteoglycans associated with calcification of shark cartilage
Authors: Takagi Minoru , Parmley Richard T. , Denys Francis R. , Yagasaki Hiroshi , Toda Yoshihisa 
Published: February 2005

AbstractProteoglycans (PGs) as well as sulfated glycosaminoglycans (GAGs) are closely associated with cartilage calcification. An inner zone of endoskeletal tesserae of sharks is composed of a unique calcified hyaline cartilage. Initial calcification can be seen in the cartilage close to the inner zone. We have ultrastructurally examined shark, Triakis scyllia, noncalcifying, calcifying, and calcified cartilage using the tannic acid‐ferric chloride (TA‐Fe), the high iron diamine (HID), and the HID‐thiocarbohydrazide‐silver proteinate (HID‐TCH‐SP) methods for localization of sulfated complex carbohydrates. In noncalcifying cartilage, TA‐Fe and HID strongly stained matrix granules which were round, ovoid, elongated, or irregularly shaped and presumably represented PG monomers. The size and staining intensity of the reactive matrix granules progressively decreased in calcifying cartilage toward the calcification front of the calcified cartilage. Similarly, a progressive decrease in the size of the HID‐TCH‐SP stain deposits in the matrix granules was observed in the calcifying cartilage close to the calcification front and was interpreted as a decrease in length of sulfate containing GAG chains. In the calcified cartilage, the highly calcified areas were often localized in the calcification front and contained few or no small HID‐TCH‐SP stain deposits, whereas the weakly calcified regions contained more stain deposits. These results indicate that partial and complete degradation of sulfated GAGs and/or PGs may be a requisite for calcification of shark cartilage.
Quantitative changes in the morphology of the aging canine prostate
Authors: Zirkin Barry R. , Strandberg John D. 
Published: February 2005

AbstractSterological methods at the light and electron microscopic levels were used to examine the morphological changes in the beagle prostate associated with inceasing age and with the occurrence of spontaneous benign hyperplasia. Analyses of semithin sections of tissue embedded in plastic revealed that proliferation of prostatic glandular and stromal components, increase in epithelial cell numbers, and increase in epithelial cell size all contributed to the dramatic increase in prostate weight seen in aging dogs. Analyses at the electron microscopic level revealed that the volume densities of rough endoplasmic reticulum and secretion granules were significantly lower in epithelial cells of the immature prostate than in the prostate of mature dogs (greater than 1.5 years of age). In contrast, no significant difference were seen in the volume densities of rough endoplasmic reticulum, free ribosomes, secretion granules, smooth endoplsmic reticulum, or mitochondria in randomly selected prostatic epithelial cells of dogs 1.5 to 9 years of age, whether or not the prostates were hyperplastic.
Morphological and ultrastructural aspects of the activation of avian medullary bone osteoclasts by parathyroid hormone
Authors: Miller Scott C. , Bowman Beth M. , Myers Ralph L. 
Published: February 2005

AbstractThe activation of physiologically inactive medullary bone osteococlasts by paratathyroid hormone (PTH) was examined using light and electron microscopy and histomorphometric methods. Medullary bone osteoclasts are functionally inactive during the avian egg‐laying cycle when an egg shell is not being calcified in the shell gland. Japanese quail hens were given 0.5 IU/g PTH and the medullary bone osteoclasts were examined up to 90 min later. Administration of PTH results in rapid changes in osteoclast morphology and ultrastructure. Within 10 min ectoplasmic regions containing condensed‐appearing material are evident in areas of the cell adjacent to bone surfaces. In tannic acid‐fixed specimens, these ectoplasmic regions contain bundles of filaments extending perpendicularly from the osteoclast plasma membrane into the cytoplasm. It is in these areas that ruffled border development is initiated. Even at 10 min after PTH administration, mineral crystals are seen between the developing cell surface invaginations and folds. By 15 min after PTH administration, ruffled borders have appeared next to bone surfaces. The rapid development of ruffled borders on medullary bone osteoclasts after PTH is confirmed by electron microscope histormorphometry. By 30 min after PTH administation, ruffled borders are well developed and large endocytic vaculoles are beginning to appear in the osteoclast cytoplasm. Light microscope histomorphometric measurements indicate that osteoclasts are also increasing in size and speeading along bone surfaces with time after PTH administration. This study provides a morphologic and ultrastructural desciption of osteoclast activation by PTH. The results indicate that osteoclasts may effect rapid changes in bone resorption and mineral metabolism due to exogenous PTH in hens.
The anionic barrier system on the mesonephric renal glomerulus of the brown hagfish, Paramyxine atami Dean (cylostomi)
Authors: Tsujii Tadashi , Naito Ichiro , Ukita Satoko , Ono Toshiro , Seno Satimaru 
Published: February 2005

AbstractThe distribution of anionic groups of acid mucopolysaccharides on the surface of glomerular constituents of a brwon hagfish, Paramyxine atami Dean, has been studied morphologically. The ionized anionic groups of acid mucopolysaccharides were labeled on fixed tissues by stainig with cationic cacodylate iron colloid (Fe‐Cac) at pH 4.0. The glomerular permeability to cationic and anionic macromolecules was observed morphologically in the kidney of the animal injected native anionic ferritin (NF) or cationized ferritin (CF) into the dorsal aorta.Histochemical staining of tissues with Fe‐Cac (pH 4.0) revealed the ionized anionic groups of acid mucopolysaccharides on both luminal and abluminal surfaces of endothelial cells, within the glomerular basement membrane (GBM), and on the visceral epithelial cell surface facing the urinary space. The CF molecules introduced into the dorsal aorta easily passed through the fenestrae of the capillary endothelial cell layer and the thick fibrillar GBM, reaching the urinary space to be adsorbed to the visceral epithelial cell surface or taken up by these visceral epithelial cell. On the other hand, NF hardly passed through the capillary wall. These results show that the nonosmoregulating mesonephric glomerulus of the brown hagfish has a working anionic barrier system. The function of its glomerulus is compared to that of the mammalian metanephric glomerulus.
An immunohistochemical study of nuclear proteins in differentiating epidermal cells
Authors: Fukuyama Kimie , Meceira Juan , Tuffanelli Denny L. , Epstein William L. 
Published: February 2005

AbstractBoth DNA and RNA disappear from the nucleus during differentiation of granular cells into cornified cells but the fate of nuclear proteins remains unknown. We investigated localization of nuclear proteins in rat epidermis by light and electron microscopic immunoperoxidase techniques. As a probe, three sera that reacted, respectively, with the nucleoplasm, nucleolus, and nuclear envelope of basal cells of rat epidermis were used. In granular cells both the antinucleoplasm serum and antinucleolus serum increased intensity of the nuclear staining, but they reacted also with ribosomes, filaments, and periphery of keratohyalin granules in the cytoplasm. The staining appeared diffusely in cornified cells and identification of nuclear components became impossible. In contrast, the antinuclear envelope serum stained only the nuclear outline in granular cells and continued to stain the nuclear contour in cornified cells of the fourth and fifth proximal cell layers. The antigenic components surrounded amorphous but not filamentous materials in cornified cells. These findings suggest that some nuclear proteins become immunologically indistinguishable from cytoplasmic protein. However, the nuclear envelope protien maintains its localization even after nucleic acids are lost and the nuclear space is detectable in cornified cells by use of autoantibody directed to this protein(s).
The effect of age, pairing, copulation, and 2‐Br‐α‐ergocryptine in the male Mongolian gerbil on the prolactin cells in the anterior pituitary identified by immunocytochemical and Herlant's tetrachrome methods
Authors: Ortman Robert , Perez Frank 
Published: February 2005

AbstractNear‐adjacent, midsagital sections of pituitaries of infantile and adult male Mongolian gerbils in several experimental groups (bachelor, paired, tartaric acid‐injected, postcopulatory gerbil, and postcopulatory animal injected with 2‐bromo‐α‐ergocryptine [CB‐154]), were stained by a modification of Herlant's tetrachrome and by the peroxidase‐labeled antibody method for prolactin. Cell counts of erythrosinophils and cells immunoreactive for prolactin were made. Sequential staining procedures and thin adjacent sections were used to correlate the staining results.Erythrosinophils were very rare in the infant pituitaries; they increased (P < .01) in numbers in bachelaor pituitaries, remained at the same level (P > .05) in paired animals, increased (P < .01) in the postcopulatory gerbils that were injected with tartaric acid, and increased much less (P < .05) in postcopulatory males that were injected with CB‐154.Prolactin cells were present in modest numbers in infant pituitaries; they increased (P < .01); in bachelors and reached their highest number in paired animals (P < .001); they remained unchanged (P > .05) in tartaric acid‐injected postcopulatory animals but declined (P < .001) in CB‐154‐injected, postcopulatory animals. The number of prolactin cells was always significantly greater (P < .001) than the number of erythrosinophils.Correlative studies revealed the erythrosinophils, some of the light blue cells, and some of the chromophobes gave positive immunocytochemical reactions for prolactin.Apparently, CB‐154 inhibited the erythrosinophils and the immunoreactive prolactin cells in the postcopulatory male gerbil, as indicated by a reduction in the number, size, and staining intensity of the cells.
Lymphocyte proliferation in neonatally thymectomized rats
Authors: Granata Anna Luisa , Vecchi C. , Budassi R. , Corsi A. 
Published: February 2005

AbstractAutoradiography has been used to evaluate lymphocyte proliferation in the neonatally thymectomized rat in comparison with the normal animal. The data obained show that the proliferative activity of lymphocytes is greatly increased in the thymus‐dependent areas 4–6 weeks after thymectomy, whereas it is normal or slightly increased 3 months laters. It seems plausible to assume that a thymus factor or chalones in situ produced by specific cells normally regulate the proliferation of thymus‐derived cells. The increase of the proliferative activity accounts for the repopulation of the thymus‐dependent areas, which are completely replenished in the older animals. Recirculation of the thymus cells is not confined to the thymus‐dependent areas.
The development of capillaries in the telencephalon of Beagle puppies
Authors: Leuschen M. Patricia , Shuman Robert M. , Nelson Robert M. 
Published: February 2005

AbstractThe microvessels of the telencephalons of Beagle puppies between newborn and 72 hours of age were investigated ultrastructurally at 24‐hour intervals. The morphometry of the microvasculature from the germinal matrix was compared with that of the microvasculature from the borderzone cerebral cortex. The endothelial cell walls of the microvessels from these two sites were similar during the study period, but the lumina of the matrical microvessels were significantly larger than the lumina of the control cortical microvessels. The proportion of matrical microvessels with large lumina undergoes progressive attrition with time. The values (areas) for the lumina of the matrical microvessels, and their distribution, come to resemble those of the cortex. The morphometry of the cortical microvasculature is comparatively static. The data suggest that there is an active modification in the microvasculature of the germinal matrix of the Beagle puppy in the immediate postnatal period.
The effect of beta‐aminoproprionitrile on the periodontal ligament: II. Radioautographic study of collagen secretion from fibroblasts
Authors: Cho Moon‐Il , Garant Philias R. 
Published: February 2005

AbstractFibroblasts are distributed evenly throughout the periodontal ligament (PDL) of normal mice. In mice fed beta‐aminoproprionitrile (β‐APN) the fibroblasts undergo aggregation to form palisades of closely juxtaposed cells abutting pools of acellular collagenous matrix. Individual fibroblasts within these aggregates retain their polarized cytoplasmic organization and continue to synthesize and secrete collagen. However, unlike normal PDL fibroblasts, the β‐APN‐treated cells appear immobilized by well‐developed cell‐to‐cell adherens‐type junctions along their lateral surfaces. We studied collagen secretion from β‐APN‐treated fibroblasts by light and electron microscopic radioautography after injection of 3H‐proline. Newly synthesized collagen was secreted from the distal ends of the β‐APN‐aggregated fibroblasts as a distinct band of labeled material, resembling the pattern of matrix deposition seen in osteogenesis and dentinogenesis. The radioactive band of collagenous matrix was displaced further away from the fibroblasts at 2 and 4 days after 3H‐proline injection as more collagen was secreted.This pattern of radiolabeled collagen secretion confirmed previous observations that PDL fibroblasts are highly polarized and that collagen secretory granules are extruded from the distal or secretory pole of the cell. In normal PDL the even distribution of fibroblasts and the complex interrelationship of their distal cell processes leads to a diffuse pattern of silver grain deposition, masking the oriented flow of new collagen from the distal ends of individual fibroblasts.Analysis of electron microscopic radioautographs revealed that newly synthesized collagen was packaged and secreted from β‐APN‐treated fibroblasts via the normal cytoplasmic pathways but at a slower rate.
Immunocytochemistry of albumin in hepatocytes after overnight starvation and during a diurnal cycle in young rats
Authors: LeBouton A. V. 
Published: February 2005

AbstractThe indirect immunoperoxidase method was used to identify albumin in hepatocytes of young rats before and after periods of starvation and during a normal diurnal cycle. All liver cells in fed rats contained an abundance of albumin, whereas hepatocytes from overnight fasted animals showed minimal amounts of the protein. Hepatocytes in rats on the diurnal cycle generally contained more albumin during the light phase than in darkness. At the beginning of the dark phase, certain hepatocytes were low in albumin and they were located primarily around portal canals. Halfway through the dark period, these cells had increased in number and were located closer to terminal hepatic venules. Overnight starvation of young rats profoundly lowers hepatocyte albumin and the time of highest liver cell albumin content in the diurnal cycle of fed, young rats is during the first half of the light period.