bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of advancing age on the central response of rat facial neurons to axotomy: Light microscope morphometry
Authors: Vaughan Deborah W. 
Published: February 2005

AbstractFollowing axotomy, the regrowth of peripheral axons takes longer in older individuals than in young ones. The present study compares central responses of facial motor neurons to a crush injury of the facial nerve in 3‐month‐old and 15‐month‐old male rats sampled through 28 days post‐crush (dpc). Neuronal somata, nuclei, and nucleoli were measured in 30 μm brain stem sections within subdivisions of the facial nucleus that contain the cell bodies responsible for the movement of the vibrissae. The temporal patterns of change in the size of the three structures were interpreted with reference to the re‐establishment of functional connections, i.e., the return of voluntary vibrissae activity, which is delayed by 4 days in the older animals relative to the younger ones. There was no age‐related difference in the pattern of somal swelling and recovery, nor was there an age‐related difference in the response of nuclei and nucleoli to axotomy through 4 dpc. Both nuclei and nucleoli increased in size in animals of both age groups, but after 4 dpc in the older animals nuclear enlargement was prolonged and the nucleolar increases were less robust compared to the younger animals. The greatest age difference appeared with the re‐establishment of functional connections. In the 3‐month‐old animals, the resumption of whisker activity coincided with vigorous transient increases in the sizes of nuclei and nucleoli; in the 15‐month‐old animals, there was little nuclear response to functional recovery and a comparatively small increase in nuclear sizes. Given that signals from the periphery initiate central metabolic changes when the target is reached, this study suggests that the deteriorative effects of advancing may not simply reside in the neuron's decreased resiliency, but may reside in deficiencies in the signals derived from peripheral supporting cells, the target muscle, or in the reception of those signals.
Structural and immunohistochemical aspects of the postovulatory follicle in Japanese quail
Authors: Van Nassauw Luc , Callebaut Marc 
Published: February 2005

AbstractIn the present study, we searched for the presence of granulosa lipid spheres, of lacunae, and of the smooth‐muscle markers desmin and α‐smooth‐muscle actin, in the wall of the POF1 of the quail ovary. Lacunae, using the labelled yolk technique, were visible as large cavities in the POF1 wall. The immunohistochemical localization of desmin was similar to that observed in preovulatory follicles. A similar distribution was observed using an anti‐α‐smooth‐muscle actin antiserum, but the cells of the theca externa were also positively stained. The general conclusion was that the studied structures were similarly localized in the follicle wall, before and during the day after ovulation, but that they are more obvious in the POF, due to its general contracted state.
Functional and structural changes of rat plantaris motoneurons following compensatory hypertrophy of the muscle
Authors: Finkelstein David I. , Lang John G. , Luff Anthony R. 
Published: February 2005

AbstractThe conduction velocity and histological structure of motoneurons innervating normal and hypertrophied rat plantaris muscles were investigated. Hypertrophy was produced by ablation of synergist muscles. Single motor units were obtained by ventral root dissection and conduction velocities measured. The structure of neurons was investigated following retrograde labeling with horseradish peroxidase. A combined silver, gold and cholinesterase staining method was developed to study the motor endplate. In addition, the peripheral nerve was fixed, embedded in Araldite, and sectioned for determination of axonal size and myelin thickness. Conduction velocity of motor axons decreased following hypertrophy of the skeletal muscle (control CV = 75.8 ± 8.9 m s−1, n = 94, hypertrophy CV = 69.0 ± 12.3 m s−1, n = 84). However, no alteration in the size of motor axons or myelin thickness could account for this alteration in conduction velocity. Mean motoneuronal soma size decreased following muscle hypertrophy (soma diameter: control 36.1 ± 4.6 μ, n = 283, hypertrophy 32.9 ± 4.5 μ, n = 294). The complexity of the motor endplate increased following hypertrophy with an increased occurrence of nodal sprouts. In addition, the area of cholinesterase staining increased following hypertrophy (control 588.1 ± 297.2 μm2, n = 269, hypertrophy 857.7 ± 357.0 μm2, n = 269). This study found that both the morphological and physiological parameters of motoneurons innervating a hypertrophied muscle were shifted toward those of normal rat slow motor units.
Topography and morphology of retinal ganglion cells in Falconiforms: A study on predatory and carrion‐eating birds
Authors: Inzunza Oscar , Bravo Hermes , Smith Ricardo L. , Angel Manuel 
Published: February 2005

AbstractThe topographic distribution of retinal ganglion cells and their cell body size have been studied in five Falconiform species, including predatory (chilean eagle Buteo fuscenses australis, and sparrow hawk Falco sparverius) and carrion‐eating (chimango caracara Milvago chimango; condor Vultur gryphus, and black vulture Coragyps atratus) birds. All these species had a well defined nasal fovea and a horizontal streak. Instead of a temporal fovea as in eagles and hawks, an afoveate temporal area is present in chimango, condor, and vulture. The highest ganglion cell density was found in the nasal fovea of Falco and Buteo with 65,000 and 62,000 cells/mm2, respectively.A negative correlation between ganglion cell density and cell body size was found in all the species studied. The specializations of the temporal retina showed a rather homogeneous population of medium sized neurons, while the nasal foveas showed a homogeneous population of smaller ganglion cells. Finally, the peripheral retina showed a heterogeneous population of large, medium, and small ganglion cells. Predatory behavior appears to be closely related to foveal specializations, and is best exemplified in the eagle and hawk and to a lesser extent in the chimango.
Relationship between the tendon of the long head of biceps brachii and the glenoidal labrum in humans
Authors: Pal G. P. , Bhatt R. H. , Patel V. S. 
Published: February 2005

AbstractThe relationship between the tendon of the long head of the biceps brachii muscle and the glenoidal labrum was investigated in a large number of dissected human shoulder joints. In about 70% of the specimens examined, the labrum was deficient at the posterosuperior margin of the glenoid because the tendon of the biceps coursed over this margin to blend with the labrum. Because of this, a small crescentic accessory facet was observed at the posterosuperior margin of the glenoid. In the majority of cases, the tendon of the biceps blended with the glenoidal labrum, and only a small part of the tendon attached to the supraglenoid tubercle. However, in 25% of the specimens, the major portion of the tendon was attached to the supraglenoid tubercle.
Effects of aging on the neuroglial cells and pericytes within area 17 of the rhesus monkey cerebral cortex
Authors: Peters Alan , Josephson Karen , Vincent Stephen L. 
Published: February 2005

AbstractAn electron microscopic analysis has been carried out to compare the neuroglial cells and pericytes within the primary visual cortex, area 17, of young (5–6 years) and old (25–35 years) rhesus monkeys. All of the neuroglial cell types accumulate inclusions within their cytoplasm as they age, and the inclusions within the astrocytes and oligodendrocytes are essentially characteristic of those cell types. The astrocytes probably acquire their inclusions by phagocytosis, and it is suggested that the inclusions in the oligodendrocytes are caused by an agerelated degeneration of the myelin sheaths they produce. The inclusions within the microglia are very heterogeneous. They are more massive than in the other neuroglial cells, so that their inclusions may almost fill the microglia. Pericytes also accumulate inclusions with age and there is evidence to suggest that they empty the contents of their inclusion vacuoles directly into the capillaries. On the basis of counts of the numbers of profiles of neuroglial cells displaying nuclei in thin sections, the only cells to increase in number with age are the microglia. They show an increase of about 44% when the cortices of young and old monkeys are compared.
Localization of smooth‐muscle markers in the ovaries of some ectothermic vertebrates
Authors: Van Nassauw Luc , Harrisson Fernand , Callebaut Marc 
Published: February 2005

AbstractIn the present study, we have localized desmin and α‐smooth‐muscle actin in the ovaries of the zebrafish, the axolotl, and the red‐eared turtle, using the unlabelled antibody peroxidase‐antiperoxidase technique. In the axolotl ovary both smooth‐muscle markers were demonstrated in cord‐like structures, extended along ovarian blood vessels, and in some inner ovarian epithelium cells. In the ovaries of the teleost, smooth‐muscle‐like cells are detected in a suspensory apparatus formed by venous cords, the tunica albuginea, and the coat around the ovarian artery. Also, in the turtle ovary, smooth‐muscle‐like cells were found in a suspensory apparatus formed by chordae, the tunica albuginea, and the theca externa of the ovarian follicles. At the present time, the prevailing hypothesis is that, in addition to a role in the mechanical support, the smooth‐muscle‐like cells in the ovaries of these vertebrates seem to be important with respect to ovarian contractile processes.
Equine myenteric plexus with special reference to the pelvic flexure pacemaker
Authors: Burns G. A. , Cummings J. F. 
Published: February 2005

AbstractSellers et al. (1979, Am. J. Phys., 237: E457–E464) proposed a pelvic flexure pacemaker mechanism to account for the bidirectional contraction waves needed to both retain ingesta within the right ventral colon for cellulose digestion and terminal fermentation and to transport the digesta distad once the process has been completed. To corroborate the presence of a pelvic flexure pacemaker, we prepared whole mount samples of the tunica muscularis from 23 horses at ten sites along the large colon, cecum and jejunum. Following smooth muscle enzymatic digestion, somata of the myenteric plexus were stained with an RNA‐specific agent, Cuprolinic blue. These somata were quantified at each site to establish any regional variations in neuronal density. Results indicated an increased neuronal density at the level of the pelvic flexure, especially in the region of the left dorsal colon. The increased neuronal density at the left dorsal colon compared to the other sampling sites was statistically significant (Wilcoxon signed rank test, P<.01 at each sampling site). There was remarkable size variation (from 10–60 μ) among neurons at the individual sampling sites. However, no statistically significant size discrepancy existed between sampling sites (Friedman's rank test, P=.10). The 23 horses ranged from 6 months to 15 years of age. No age‐related differences in neuronal density was discovered (Kruskal‐Wallis ANOVA test, P>.05). Neuronal densities did not vary on the basis of sex (Wilcoxon signed pairs test, P>.05). These neuronal counts serve both as corroborative evidence for the pelvic flexure pacemaker hypothesis and as standard values for neuronal density at each of our sampling sites. These standards will provide an important foundation for future studies in gastrointestinal motility and enteric pathology.
Tenascin localization in skin wounds of the adult newt Notophthalmus viridescens
Authors: Donaldson Donald J. , Mahan James T. , Yang Hui , Crossin Kathryn L. 
Published: February 2005

AbstractEarlier studies have shown that the extracellular matrix (ECM) protein tenascin (TN) is present between uninjured epidermal cells of urodele appendages, but is absent from most of the mesenchymally derived ECM. Following appendage amputation, this distribution is reversed. TN is lost from the epidermis and appears in the ECM of the stump and the regeneration blastema. In the present study, monoclonal and polyclonal antibodies to TN were used to localize this protein immunohistochemically in limbs of the adult urodele Notophthalmus viridescens at various stages following skin removal with or without damage to underlying muscle to determine (1) if the loss of TN by the epidermis and its gain by mesenchymal tissues occurs in wounds that do not require regulation by epigenetic mechanisms, and (2) if TN is present in the provisional wound matrix beneath migrating epidermal cells. In addition, skin explants were cultured on TN‐coated dishes to learn if TN possesses active sites that can support epidermal cell migration. The results indicate that simple wounding leads to the same TN patterns as occurs following limb amputation. Tenascin loss from the epidermis could be seen as early as 6 hr after wounding, a time during which migrating epidermal cells are moving over the wound bed. During this period, there was no evidence of TN in the provisional wound matrix. In contrast to collagen, which supports considerable epidermal cell migration from skin explants, TN allowed no more migration than did the inactive protein, myoglobin.
Anionic site and immunogold quantitation of heparan sulfate proteoglycans in glomerular basement membranes of puromycin aminonucleoside nephrotic rats
Authors: Rada Jody A. , Carlson Edward C. 
Published: February 2005

AbstractRenal glomerular basement membranes (GBMs) exhibit a charge‐selective barrier, consisting of heparan sulfate proteoglycan (HSPG) that restricts the passage of anionic molecules into the urine. Previous efforts to localize the HSPG core protein within various layers of the GBM have been contradictory. Furthermore, attempts to correlate proteinuria in several disease states with a decrease in anionic sites of HSPG core protein have yielded conflicting results.When antibodies to HSPG from the EHS tumor matrix [anti‐(EHS) HSPG] and GBMs [anti‐(GBM) HSPG] were used together with immunogold to label renal tissues from puromycin aminonucleoside nephrotic (PAN) rats, immunolabeling results indicated that a portion of the protein core recognized by anti‐(EHS) HSPG was significantly reduced, while immunolabeling with anti‐(GBM) HSPG was only slightly reduced in early PAN. Anionic sites (stained with the cationic probe, polyethyleneimine) within the lamina rara externa of the GBM remained unaltered throughout the course of PAN.
Distribution of actin isoforms within cells of the seminiferous epithelium of the rat testis: Evidence for a muscle form of actin in spermatids
Authors: Oko Richard , Hermo Louis , Hecht Norman B. 
Published: February 2005

AbstractRecently, a cDNA that coded for an enteric smooth muscle γ‐actin (SMGA) that was expressed in post‐meiotic mouse testicular cells was identified. To determine the cellular location(s) of the protein encoded by this cDNA, this SMGA was probed for by immunocytochemistry in the cells of the seminiferous epithelium with two different monoclonal antibodies (Mabs), B4 and HUC 1–1, known to be muscle actin selective. As a control, we also examined the immunoreactivity of a third Mab, C4, that reacts with all non‐muscle and muscle vertebrate isoactins. Using light and electron microscopy, a progressive increase in immunolabeling was observed with the muscle selective HUC 1–1 Mab over a loose actin filamentous network distributed throughout the cytoplasm of steps 4–16 spermatids. Thereafter, the labeling decreased such that at step 17 spermatids, only cytoplasmic labeling in the tail of the spermatids was observed. No labeling of this network was noted with the C4 or B4 Mabs. However, myoid cells enveloping seminiferous tubules and smooth muscle cells of interstitial blood vessels demonstrated comparable intense labeling with each of the three Mabs. The C4 Mab intensely labeled actin filaments of the Sertoli‐Sertoli and Sertoli‐spermatid ectoplasmic specializations. Also well labeled were numerous actin filaments found in the apical Sertoli cell processes encapsulating the heads of late step 19 spermatids at stage VII of the cycle of the seminiferous epithelium. In addition, actin filamentous bundles enveloping tubulobulbar complexes of the late spermatids within the Sertoli cell apical processes were intensely labeled. The actin filaments in the Sertoli apical processes and surrounding the tubulobulbar complexes were also strongly immunolabeled with the HUC 1–1 Mab. The C4 Mab but not the B4 or HUC 1–1 Mabs, recognized actin in the subacrosomal space of steps 4–18 spermatids. This study suggests that there are muscle isoforms of actin within the cytoplasm of developing spermatids and within apical processes of Sertoli cells.
Intercellular communication within the rat anterior pituitary gland. III. Postnatal development and periodic changes of cell‐to‐cell communications in female rats
Authors: Soji Tsuyoshi , Nishizono Hisanori , Yashiro Takashi , Herbert Damon C. 
Published: February 2005

AbstractCell‐to‐cell communication by gap junctions was investigated in the female rat anterior pituitary gland from 10 through 45 days of postnatal development and in 60‐day‐old animals. Gap junctions initially appeared between adjacent folliculo‐stellate cells on day 25. Their appearance in female rats was 5 days later than that observed in males (Soji et al., 1990). Gap junction number increased until the animals became 40 days of age, when they reached a level that resembled that found in adults. In addition, a correlation was evident between the frequency of gap junctions and stages of the estrous cycle, where they were most numerous during either proestrus or estrus. These results along with those previously published suggest that gap junction formation within the female rat hypophysis is in part modulated by both gonadal steroid hormones as well as prolactin.
Estimated intracortical bone turnover in the femur of growing macaques: Implications for their use as models in skeletal pathology
Authors: Burr David B. 
Published: February 2005

AbstractAlthough macaques have been used widely to study the dynamics of bone remodeling, there have been few comparisons to skeletal tissue turnover in humans. This study analyzes variation in bone microstructure with respect to gender, age, and body weight in growing macaques to determine whether the pattern of osteonal remodeling in macaques is like that in analogous bones of humans. Histomorphometric measurements were made on femoral midshaft cross‐sections of 54 macaques from the Cayo Santiago skeletal collection. These data show that variation in bone microstructure occurs independent of gender, age, and body weight in macaques. Moreover, intracortical bone turnover in the macaque femur is much slower than in humans, making them poor models to study the effects of weightlessness, but good models to study low turnover skeletal dysplasias.
Human odontoblasts contain S‐100 protein‐like immunoreactivity
Authors: Lombardi Tommaso , di Felice Roberto , Samson Jacky 
Published: February 2005

AbstractS‐100 protein is a group of three closely related isoforms (S‐100ao, S‐100a, and S‐100b). This protein was first described as unique to the nervous system but it has also been identified subsequently in a variety of cell types of neuroectodermal (i. e., melanocytes, glial cells) and non‐neuroectodermal origin (i. e., Langerhans cells, adipocytes, chondrocytes). In the present investigation the presence of S‐100 protein was studied in human odontoblasts using a specific polyclonal antibody directed against S‐100 protein in immunoperoxidase labelling experiments. The S‐100 protein was detected in the cytoplasm of odontoblasts. This result suggests that S‐100 protein can play a role in odontoblast functions.
Changes in the distribution of filipin‐sterol complexes in the boar sperm head plasma membrane during epididymal maturation and in the uterus
Authors: Seki Naohiko , Toyama Yoshiro , Nagano Toshio 
Published: February 2005

AbstractThe distribution of filipin‐sterol complexes (FSCs) and intramembranous particles (IMPs) in the plasma membrane of the late spermatid of the boar and of the sperm obtained from the epididymides, ejaculates, and uterus 2 hours after mating was examined by a freeze‐fracture replica technique. In the late spermatid, the FSC density was found to be very low. A majority of the FSCs in the acrosomal plasma membrane (APM) appeared as protuberances on the E face in the epididymal, ejaculate, and uterine sperm. The density of the FSCs in the principal segment (PS) of the APM was 291 ± 44 FSC/μm2 (mean ± standard deviation, S. D. ), 322 ± 41 FSC/μm2 and 355 ± 31 FSC/μm2 in the caput, corpus, and cauda epididymidis, respectively. In comparison with the cauda epididymal sperm, the FSC density gradually decreased in the PS of the ejaculated (277 ± 39 FSC/μm2) and uterine sperm (243 ± 50 FSC/μm2). The reduction was especially remarkable in the equatorial segment (ES), where the density of FSCs in ejaculated and uterine sperm decreased to about half and less than half of that in the cauda epididymal sperm, respectively.Large (13 nm) and small (8 nm) IMPs were distributed evenly and densely in the P face of the APM in the late spermatid, epididymal, and ejaculated sperm. In the uterine sperm, IMP‐free areas were observed in the P face of the plasma membrane, a feature thought to represent one of the capacitation changes of the boar sperm.
Axon terminals on betz cell somata of area 4 in rhesus monkey throughout adulthood
Authors: Tigges Johannes , Herndon James G. , Peters Alan 
Published: February 2005

AbstractPrevious work in our laboratory demonstrated an age‐related decline in the size of Betz cell somata in cortical area 4 of the adult rhesus monkey brain. The present study was conducted to determine whether changes might also occur in the axon terminals upon these cortical cells. Tissue from area 4 was collected from seven rhesus monkeys and prepared for electron microscopy. The ages of the monkeys ranged from 5 to 35 years, covering the entire adult life span of this species. A total of 140 Betz cell profiles (20 per monkey) were examined. Measurements of these profiles confirmed our earlier finding of a decline in the perimeters of Betz cell somata with advancing age. The 1,540 axon terminals upon these cells, however, remained unchanged in size and length of membrane apposition, as well as in their number of mitochondria throughout the adult life (≥5 years) of the rhesus monkey. In addition, the total number of axon terminals on Betz cells did not change with age.Because the axosomatic terminals showed no age‐associated changes, the material was used to calculate parametric characteristics of Betz cells and associated terminals. Betz cell somata of the rhesus monkey were estimated to have a mean membrane surface area of 5,700 μm2. Axosomatic terminals on Betz cell somata had a mean appositional area of about 3.33 μm2 and covered about 15% of the somal surface. Thus, on average, each Betz cell appeared to receive approximately 260 axosomatic terminals.There were also some conspicuous age‐associated changes in the motor cortex that were not quantified. These included an accumulation of lipofuscin and the presence of a novel inclusion body in the somata of Betz cells. Age‐related occurrences in the neuropil included the degeneration of axons and their myelin, membrane‐bound holes, and neuritic (senile) plaques.