bluuebunny/crossref_metadata_2025_split huggingface dataset:
Primary epithelial cell cultures derived from canine prostate: Isolation, culture, and characterization
Authors: Terracio Louis , Douglas William H. J. , Pennachio Dominic , Vena Richard L. , Ofner Peter 
Published: February 2005

AbstractEpithelial‐cell‐enriched primary cultures were established from canine prostate. Minced tissue was dissociated with 750 units/ml of collagenase in F12K tissue culture medium containing 1% fetal bovine serum. This treatment resulted in the gradual removal of stromal elements from the base of the epithelial cells. After 30 minutes of digestion, aggregates of epithelial cells free of stroma were dislodged from the minced pieces of prostate. These aggregates were washed and plated at high density in F12K plus 10% fetal bovine serum. After 12–16 hours in vitro the unattached cellular aggregates were removed from the culture dishes, washed, and reinoculated into new culture vessels containing fresh medium. After 48 hours in vitro, the aggregates had attached to the culture vessels and spread out to yield discrete patches of epithelial cells. By 120 hours in vitro the patches of cells had grown and coalesced to form a confluent monolayer of epithelial cells. Ultrastructural examination of these cultures indicated that adjacent cells were joined by desmosomes and tight junctions and had tonofilaments and microvilli, giving the cells an epithelial appearance. The cells contained rough endoplasmic reticulum, Golgi apparatus, and secretory granules similar to those of the epithelial cells in the intact organ. In addition, intracellular “blebs” containing acid phosphatase were observed in the monolayers and were found to increase in size and number with time in vitro. Differentiated function of the cultures was demonstrated by the presence of ornithine decarboxylase and acid phosphatase and the ability of the cultures to metabolize testosterone to primarily 5α‐reduced metabolites.
Permeability of the neonatal rat choriocapillaris to hemeproteins and ferritin
Authors: Pino Richard M. , Essner Edward , Pino Linda C. 
Published: February 2005

AbstractThe permeability of the endothelium of the capillaries of the rat choriocapillaris to circulating macromolecules was examined during the first postnatal week of development using hemeproteins of different molecular dimensions and ferritin. At this stage of development capillaries and photoreceptor cells in the neural retina are not fully formed, but the choriocapillaris has an adult‐like morphology. Thus, through these differences in neural and vascular architectures the possible functional relationships between the retina and choriocapillaris can be explored. High levels of horseradish peroxidase [Einstein‐Stokes radius (ESR) 3 nm] activity were localized in Bruch's membrane within 2 minutes after intravenous tracer injection. In contrast, scant levels of hemoglobin (ESR, 3.2 nm) and no catalase (ESR, 5.2 nm) activity were observed here at 75 and 90 minutes, respectively. Only a few ferritin particles (ESR, 6.1 nm) crossed the choriocapillary endothelium after a 90‐minute circulation. The results demonstrate that in the neonatal rat the choriocapillaris has the same restrictive properties as have been described for the adult eye (Pino and Essner, 1980, 1981), even in the absence of retinal capillaries and functional photoreceptor cells.
Testosterone action on the ventral prostate lobe of the castrated rat as assessed with a stereologic morphometric method
Authors: Huttunen Eero , Romppanen Timo , Helminen Heikki J. 
Published: February 2005

AbstractThe effects of testosterone (1 mg testosterone propionate/100 g body weight for 30 days) on the ventral prostates of rats castrated 30 days prior to the onset of hormone treatment was investigated with a stereologic morphometric method. Testosterone induced rapid growth of the prostate, which was reflected by a 29‐fold increase in acinar parenchyma but only a 2.6‐fold increase in interacinar tissue. There was a 23‐fold increase in the total amount of glandular epithelium and a 36‐fold increase in total luminal amount. Various volumetric fractions, total surface area, total tubule length, height of the epithelium, mean diameter of the tubules, and mean distance between the tubules and between the glandular centers were calculated. Growth of the acinar parenchyma, especially of the glandular lumen, was the dominant pattern. We could not demonstrate any remarkable responses in the interacinar tissue during any phase of testosterone treatment.
Monoamines in the early chick embryo: Demonstration of serotonin synthesis and the regional distribution of serotonin‐concentrating cells during morphogenesis
Authors: Wallace James A. 
Published: February 2005

AbstractMonoamine compounds, such as serotonin (5‐HT), have been previously suggested to regulate the early development of the chick embryo. Possible roles for 5‐HT in chick morphogenesis were investigated further by examining the distribution of sites that concentrate 5‐HT as well as the ability of embryos to synthesize 5‐HT during this period. Following the in vitro incubation of chick embryos with 5‐HT, cells accumulating 5‐HT were localized by the formaldehyde‐induced fluorescence (FIF) technique; these sites of 5‐HT concentration were mapped and studied with respect to changes in their developmental patterns during morphogenesis. Locations of 5‐HT FIF included two regions of the brain within the floor plate of the mesencephalon and caudal myelencephalon, and within scleratome cells of somites advanced in differentiation. Additionally, two separate zones of 5‐HT FIF appeared in the neural tube caudal to the somites in conjunction with a small band of intense FIF in the caudal end of the notochord. Once established, the capabilities for 5‐HT concentration in the brain and somites persisted at the same locations during development, whereas these capabilities in caudal portions of the embryo were transient and appeared to move down the embryo as the embryo lengthened. These changes in the patterns of 5‐HT FIF in caudal segments of the neural tube and notochord correlated spatio‐temporally with the progression of caudal neuropore closure. Additional experiments, involving the use of anti‐5‐HT immunocytochemistry, were undertaken to examine the characteristics of 5‐HT concentration. The mechanism(s) of 5‐HT concentration at all locations appeared to have a high affinity and specificity for 5‐HT; however, in contrast to the transient mechanism situated more caudally in the embryos, the uptake mechanism at rostral locations required energy and was blocked by a 5‐HT uptake inhibitor (fluoxetine). The ability of embryos to synthesize 5‐HT was demonstrated by the generation of 5‐HT (localized by FIF and immunocytochemistry) in embryos treated with the 5‐HT precursors, 5‐hydroxytryptophan or L‐tryptophan. Confirming evidence of 5‐HT synthesis was provided by a marked reduction in immunostaining obtained with either precursor in the presence of 5‐HT synthesis inhibitors (R04–4602 or para‐chlorophenylalanine). Although the sites of synthesis remain uncertain, endogenous 5‐HT was detected (after monoamine oxidase inhibition) at all sites of 5‐HT concentration. These results provide further support for the suggestion that 5‐HT may be involved in various aspects of morphogenesis at specific sites within the chick embryo.
The effect of zinc deficiency on the ultrastructure of rat adrenal cortex
Authors: Dupree Alphonse E. Leure , Rothman Richard J. , Fosmire Gary J. 
Published: February 2005

AbstractThe adrenal cortex of male Sprague‐Dawley weanling rats maintained on a zinc‐deficient diet was studied by electron microscopy. There was a gradual increase in lipid droplets in the zona fasciculata which was quite marked at 7 weeks, but increased lipid was not observed in the zona glomerulosa or reticularis of zinc‐deficient rats. The adrenal cortex of the control animals did not show altered lipid content. A possible explanation for the effect of zinc deficiency on the adrenal cortex is offered.
Ultrastructural changes associated with the mineralization of deer antler cartilage
Authors: Newbrey J. W. , Banks W. J. 
Published: February 2005

AbstractThe maturation and mineralization of deer antler cartilage were investigated ultrastructurally by using enzymatic digestions and subsequent staining with ruthenium red (RR) or phosphotungstic acid (PTA).RR staining of matrix granules was observed in the immature prechondroblastic matrix and became more intense as the cartilage matured into a mineralized tissue. The granules got larger and more numerically dense in the mature matrix. There were matrix granules that coalesced around matrix vesicles or remnants of such in the mineralized zone. These granules were observed after demineralization, and they were RR and acidic PTA‐positive (they were not susceptible to hyaluronidase nor trypsin digestion, however). It appears that the granules were modified such that the matrix vesicle formed a centralized nidus for mineralization. The growth of hydroxyapatite crystals along matrix granules (which in this zone may or may not represent proteoglycan monomers) may have caused the coalescence.Microfibrils associated with matrix granules probably represented the hyaluronic acid core of the large proteoglycan complexes because of their susceptibility to hyaluronidase digestion.
Structure and growth activities of the mandibular condyle in monkeys (Macaca fascicularis): I. Intracondylar variations
Authors: Luder H. U. 
Published: February 2005

AbstractEight condyles of four growing monkeys (Macaca fascicularis) of estimated ages between 1.6 and 3.6 years (minimum and maximum) were analyzed using radioautographic, histometric, and stereologic techniques. The aim of the study was to examine the relationship between intracondylar variations in structure and growth activities. The animals received 3H‐proline (1 mCi/kg body weight) and 3H‐thymidine (0.5 mCi/kg body weight) 24 and 3 hours, respectively, prior to sacrifice. The perichondral and chondral layers of the condylar articular covering as well as the subchondral zone of erosion were examined at different sampling sites distributed systematically in the anteroposterior and lateromedial dimension of the articulating surface. Intracondylar variations observed with respect to morphometric and radioautographic parameters suggest the following biologic mechanisms contributing to mandibular growth in a superior‐posterior direction. Greater mitotic activity at the central and posterior sites of the condylar perichondrium generates a population of progenitor cells that is larger in these than in other regions. On the other hand, the rate of differentiation of these progenitor cells into chondroblasts and chondrocytes, i.e., the “migration” into and through the chondral layers of the articulating covering, seems to be enhanced in the same superior and posterior areas. Additionally, while “migrating” faster, these cartilage cells become larger and produce greater amounts of extracellular matrix than those in the anterior parts of the condyle. Finally, enhanced resorptive activities in the superior and posterior regions of the subchondral zone of erosion provide an increased “loss” of degenerated chondrocytes, thereby establishing the basis for a cartilaginous drift in the superior‐posterior direction.
Follicular growth and intraovarian and extraovarian oocyte release after daily injections of melatonin and 6‐chloromelatonin in the Syrian hamster
Authors: Spanel‐Borowski Katharina , Richardson Bruce A. , King Thomas S. , Petterborg Larry J. , Reiter Russel J. 
Published: February 2005

AbstractGroups of adult female Syrian hamsters (Mesocricetus auratus) were injected daily at 17:00 hr with 2.5, 15, or 25 μg of melatonin (Mel) or 6‐chloro‐melatonin (Cl‐Mel) for 12 weeks. An ovary from each animal was completely serially sectioned for light microscopic investigation. Judging from the presence of corpora lutea, there were some animals in each group that continued to cycle, although the postestrous, white mucous discharge had disappeared. Noncycling animals were most often found in the 25‐μg group of Cl‐Mel. Only uterine weights of noncycling animals treated with either 25 or 15 μg of Mel or Cl‐Mel were statistically significantly depressed versus controls. Cl‐Mel (25 μg) significantly suppressed the total number and size of antral follicles (P> 0.05). Follicular ruptures with incomplete or complete release of the oocyte out of the follicular compartment were observed. The oocyte release occurred either into the ovary (“intraovarian oocyte release: IOR”) or outside of the ovary (“extraovarian oocyte release: EOR”). Compared with controls, the total number of IOR was increased in all experimental groups with the exception of the 2.5‐μg group of Cl‐Mel. IOR appeared in both preantral and antral follicles, and often IOR was complete. In controls, only preantral follicles were involved in IOR; these were primarily incomplete ones. IOR was seen in cycling and noncycling animals. By contrast, EOR was exclusively observed in noncycling hamsters. It is concluded that the cessation of postestrous, white mucous discharge is not necessarily an index for a halt in cyclic ovarian function. Injections of 25 μg of Cl‐Mel are more effective than 25 μg of Mel in suppressing ovarian function. Both Mel and Cl‐Mel increase the frequency of IOR. Finally, noncycling hamsters show EOR that is regarded as an abnormal ovulation.
[3H]thymidine uptake in cells of rat condylar cartilage
Authors: Heeley J. D. , Dobeck J. M. , Derice R. A. 
Published: February 2005

AbstractWeanling rats were injected intraperitoneally with [3H]thymidine and sacrificed from 5 min to 20 days later. Their mandibular condylar cartilages were examined histologically, by thin‐layer autoradiography, and by using liquid scintillation and microscopic counting methods.Labeled DNA appeared in some of the chondrocytes of the resting zone as early as 10 min postinjection, and reached the proliferative zone by 24 hr and the hypertrophic zone by 4 days. The labeling pattern in the last zone was more disperse, being oriented toward the periphery of the cells as they became hypertrophic.The maximum number of labeled chondrocytes was reached by 2 hr postinjection. These amounted to approximately 11% of the total chondrocyte population, the majority of which were located in the resting zone (73%). It is concluded that, over this period, the mitotic index for these cells is 50–60 per thousand resulting in approximately 100 labeled chondrocytes.In addition, some of the chondroclasts at the erosion front contained labeled DNA as early as 5 min after [3H]thymidine administration. By 10 min, 65% of these cells exhibited one or more labeled nuclei, and the ratio of labeled cells remained high through 20 days. Chondroclasts were seen to contain a diffuse label within their cytoplasm after 5 days. This label was similar to that seen in hypertrophic chondrocytes that had reached the erosion front by that time.Clearly, chondroclasts exhibit nuclear division and do not form from fusion of hypertrophic chondrocytes, although which specific mononuclear cells may act as chondroclast progenitors is not clear. In addition, these multinucleate resorbing cells are capable of ingesting or phagocytizing nuclear remnants from hypertrophic chondrocytes at the eroding face of cartilage.
Three‐dimensional characteristics of the endoplasmic reticulum in the columnar cells of the rat small interstine: An electron microscopy study in thick sections
Authors: Thiéry G. , Gaffiero P. , Bergeron M. 
Published: February 2005

AbstractThe endoplasmic reticulum (ER) of the columnar cells of the rat jejunum was studied with a specific block‐staining technique and standard transmission electron microscopy. A new three‐dimensional model, based on the analysis of stereo pair photographs, is proposed; this model suggests that the endoplasmic reticulum may constitute a transcellular route.Thick sections (0.5–1 μm) of columnar cells were made after a 5‐day impregnation with osmium tetroxide and were examined by standard transmission electron microscopy at 80–100 kV. The evolution of the ER during the cellular ascent of cells from the crypt to the top of the villus is toward a greater complexity. At the base of the crypt of Lieberkühn, no definite organization is noted, and most often only the nuclear envelope and canalicular elements are stained. The endoplasmic reticulum of the mature columnar cells forms a continuous network of canaliculi and fenestrated saccules; it extends from the apex, below the microvilli, to the lateral and basal plasma membranes, and sends many projections to the nuclear envelope. In the basal part of the cell, below the nucleus, the ER consists mainly of tubular canaliculi, whereas mostly saccules, are observed in the supranuclear part. The canaliculi have a diameter, of 40–60 nm. Fenestrated saccules appear to form a continuous tubular structure surrounding mitochondria; the saccules have a thickness of 25–40 nm and possess irregular perforations of 35–60 nm. Finally, in some cells, the endoplasmic reticulum seems to show functional differences as reflected by the absence of reaction in cells adjacent to well‐stained cells in the same part of the villus; thus the osmium impregnation technique appears to be a valid tool for studying the ER organization.
Quantitative ultrastructural characteristics relating to transport between luteal cell cytoplasm and blood in the corpus luteum of the pregnant rat
Authors: Dharmarajan A. M. , Bruce N. W. , Meyer G. T. 
Published: February 2005

AbstractThe synthesis and secretion of progesterone by the corpus luteum (CL) may be limited or controlled by transport mechanisms operating between circulating blood and luteal cell cytoplasm. To examine this possibility, the structural features involved in transport, including membrane surface areas and diffusion distances, were quantitated in the CL of 16‐day pregnant rats. One ovary from each of eight rats was fixed by perfusion via a cannula inserted into the parametrial artery, and two CL from each ovary were processed for electron microscopy and examined with standard morphometric techniques. For comparison, one CL from each of a further eight ovaries was diced into small cubes, fixed by immersion, and analyzed similarly. In perfusion‐fixed CL, there was a substantial volume of vascular space (20% of the total) and interstitial space (5%) and an extensive surface area of capillaries (441 mm2 per CL). The luteal‐cell membrane had numerous projections which increased its surface area by a factor of 3.08. Almost 60% of the luteal‐cell surface directly faced a capillary, and a further 37% faced interstitial space which probably extended to a capillary surface. Only 3% was in direct contact with a neighboring luteal cell. Despite the extensive interstitial space the harmonic mean thickness, an estimate of likely effective diffusion distance between luteal cell cytoplasm and blood, was only 0.42 μm. This was less than half of the calculated arithmetic mean thickness owing to the presence of surface projections and an uneven capillary endothelium. Results from immersion‐fixed CL were qualitatively similar; but the proportion of interstitial space was only 59% of that in perfusion‐fixed CL, and the contribution of surface projections to the total area of luteal‐cell membranes was significantly reduced. Collectively, these results suggest that membranes and spaces between blood and luteal‐cell cytoplasm are structured so as to minimize transport distances.
Characterstics of motor innervation of muscle spindles in the monkey
Authors: Kucera Jan 
Published: February 2005

AbstractThe motor nerve supplies of four whole muscle spindles and 16 half spindles (equator and one pole) from lumbrical muscles of the monkey were reconstructed by light microscopy of serial, 1‐μm‐thick transverse sections. The 24 poles of spindle were innervated by 37 fusimotor (γ) axons and 18 skeletofusimotor (β) axons. Sixty‐seven percent of spindle poles received γ axons only, 25% were supplied by both γ and β axons or β axons only, and 8% were not innervated by motor axons. All β axons except one and 35% of the γ axons innervated one type of intrafusal fiber only. The other 65% of γ axons coinnervated two or three different types of intrafusal fiber. Gamma axons innervated the (dynamic) bag1 intrafusal fiber together with the (static) bag2 and/or chain fibers in 65% of the poles of spindle in which the bag1 fiber received motor supply. The bag2 fiber shared γ‐innervation with either the bag1 or chain fibers in nearly every spindle pole. The chain fibers were usually coinnervated with the bag2 fiber by γ axons. Compared to spindles in the cat tenuissimus muscle, the monkey spindle received fewer γ axons and had a higher incidence of shared γ‐innervation between the dynamic and static intrafusal fibers. Unlike cat tenuissimus spindles, the monkey spindles lacked γ axons selective to the bag2 fiber. However, the β motor system within the monkey lumbrical muscle was organized in a manner similar to the cat tenuissimus muscle. The significance of these observations is discussed relative to the general motor organization and function of spindles in different muscles and species of mammals.
Perivascular cells in cartilage canals of the developing mouse epiphysis
Authors: Cole Ada A. , Wezeman Frederick H. 
Published: February 2005

AbstractMorphological variability among perivascular cells adjacent to cartilage matrix during the elongation of canals through both uncalcified and calcified matrix has not been reported. Cartilage canals were located in distal femoral epiphyses of 5‐ to 7‐day‐old mice and identified as vascular channels arising from perichondrial surfaces along the condyles and intercondylar fossae. Three stages of canal development were identified based on the length of canals and on characteristics of chondrocytes and matrix surrounding the canals. Superficial canals terminated in uncalcified matrix of resting cartilage; intermediate canals terminated in matrix containing hypertrophic chondrocytes; deep canals terminated in calcified matrix. The ultrastructural morphology of perivascular cells in contact with the matrix varied in the three stages. Cells resembling fibroblasts and vacuolated macrophages were present adjacent to the uncalcified matrix in superficial canals. At the tips of intermediate canals, cells resembling fibroblasts were larger, contained numerous lysosomes and phagolysosomes, and were in intimate contact with the matrix. At the tips of deep canals, chondroclasts with ruffled borders and clear zones contacted the calcified matrix. The results indicate that (1) mouse epiphyses provide a suitable model for studying cartilage‐canal perivascular cells, (2) calcification of cartilage matrix occurs along the course of the canal, and (3) the morphology of perivascular cells in contact with the matrix may be determined, in part, by matrix calcification.