bluuebunny/crossref_metadata_2025 huggingface dataset:
Site‐specific regulation of osteogenesis: Maintenance of discrete levels of phenotypic expression in vitro
Authors: McCulloch Christopher A. G. , Tenenbaum Howard C. , Fair Catherine A. , Birek Catalena
Published: February 2005

Intrinsic differences in bone formation rate, cell numbers, and the percentages of cells expressing alkaline phosphatase activity were studied in explants of chick calvaria periosteum cultured for 4 days and 6 days. Proliferation, differentiation, and bone production were examined in radioautographs of plastic sections and by using whole‐culture biochemical assays of protein and alkaline phosphatase. Ectocranial explants at both 4 days and 6 days exhibited more alkaline phosphatase‐positive cells and significantly more bone formation than endocranial cultures. There were no detectable differences in cell numbers or 3H‐thymidine labeling indices. The volume of bone synthesized per osteoblast was significantly higher in the ectocranial group. Examination of bone stripped of periostea and then cultured for 4 days revealed that large areas of bone were covered by osteoblasts, indicating that the periosteal explant cultures were composed almost exclusively of osteoprogenitor cells and fibroblasts. The data suggest that the level of expression of predetermined osteogenic phenotypes can be maintained in vitro for 6 days following explantation and that variations in the rate of osteogenesis are programmed into progenitor cells prior to their differentiation into osteoblasts.
Immunogold distribution of actin during spermiogenesis in the rat, hamster, monkey, and human
Authors: Fouquet Jean‐Pierre , Kann Marie‐Louise , Dadoune Jean‐Pierre
Published: February 2005

The localization of actin during spermiogenesis in the rat, hamster, monkey, and human was examined at the ultrastructural level using postembedding immunogold methods. Results revealed a similar pattern of actin distribution in these four species, although the staining intensity was higher in rodent spermatids than in those obtained from primates. Gold particles were first detected in the nascent subacrosomal space of round spermatids. This subacrosomal labeling extended as the acrosome spread over the nucleus during the elongation phase, remained unchanged during the first steps of the maturation phase, and disappeared completely before spermiation. Thus, using antiactin probes (present results) and other specific probes, actin appears to be a consistent component of the subacrosomal layer of spermatids during the greater part of spermiogenesis in many mammals.
Cytoplasmic stress fibers in the developing heart
Authors: Sumida Hiroshi , Ashcraft Robert A. , Thompson Robert P.
Published: February 2005

Rhodamine‐conjugated phalloidin staining was used to study the distribution of filamentous actin in the developing heart of embryonic chicks and rats during the morphogenetic period of cardiac septation. In the chick, intense fluorescence indicative of abundant filamentous actin was observed along the myocardium and in the mesenchymal condensations that formed within the aorticopulmonary septum at day 5. Such cellular condensations and concentration of filamentous actin were not seen in the atrioventricular cushions nor in the preseptation outflow tract. Similar results were found in the 14‐day rat embryo. In electron micrographs, microfilament bundles with irregular dense bodies were seen in elongated mesenchymal cells between the valve sites of both species. Cell‐cell contacts were observed between such elongated cells and myocyte processes protruding from the nearby myocardial sheath. These histochemical and ultrastructural observations suggest that such mesenchymal condensations serve a specialized mechanical tensile role during embryonic septation of cardiac outflow channels.
Distribution of 35S‐Sulfate within the transseptal ligment of the mouse
Authors: Johnson Roger B.
Published: February 2005

The distribution of 35S‐sulfate‐labeled macromolecules was examined within three regions of the transseptal ligament: the (1) mesial, (2) middle and (3) distal thirds. Swiss mice, 6 weeks of age, were injected with 35S‐sulfate and killed after 1, 6, and 12 hours and 1,2,3,4,5, and 7 days. Silver grains and cell nuclei were counted on autoradiographs which had been counterstained by the Van Gieson method, and mean counts were analyzed statistically. Analysis of variance revealed no significant differences in mean number of cell nuclei between regions throughout the course of the experiment. 35S‐sulfate was rapidly incorporated into the transseptal ligament macromolecules. Grain counts were highest 6 hours after injections: counts were higest over the middle and lowest over the mesial thirds of the ligament. The rate of grain removal was significantly higher in the middle third compared to the mesial or distal thirds (P<0.001) and was significantly lower in the mesial third compared to the middle or distal thirds (P<0.001). The half‐life of labeled macromolecules was significantly greater in the mesial and distal thirds than in the middle third (P<0.005). The data demonstrates significantly higher rates of turnover of 35S‐sulfate‐labeled micromolecules in the middle region of the transseptal ligament. Since cellular density was similar throughout the transseptal ligament, higher turnover rates of 35S‐sulfate‐labeled macromolecules peobable indicate higher rates of cellular activity in this region, possibly a result of tissue remodeling coincident to stresses generated by occlusal forces and physiologic drift of the adjacent teeth.
Granule formation and polarity of the Golgi apparatus in neutrophil granulocytes of the rat
Authors: Tang R. Xue Ming , Clermont Yves
Published: February 2005

The formation of granules in neutrophil (heterophil) progenitor cells was examined with the electron microscope in sections of rat bone marrow fixed in 2% glutaraldehyde and postfixed with reduced osmium (Karnovsky:Proceedings of the 11th Meeting, American Society of Cell Biologists, Abstr. 284, p. 146, 1971). The cells were also osmicated in 2% osmium tetroxide for 36 hours at 37%C to outline the osmiophilic element usually observed on the cis‐face of the stacks of saccules of the Golgi apparatus of various cell types. In myeloblasts, which do not produce granules, the cis‐osmiophilic element (CE) was found on the concave face of the C‐shaped Golgi stacks, while the primary (azurophilic) granules fromed in relation to elements on the concave aspects of the stacks. In myleocytes, the situation was reversed: the CE was found on the concave face of the Golgi stacks, while the secondary (specific) granules were seen forming in relation to elements on the convex aspect of the stacks. Finally, in metamyelocytes and mature neutrophils in which no granule formation took place, the appearance on Golgi stacks varied: they were either flat or C‐shaped. The CE was indiscriminately found on one face or the other of the flat Golgi stacks of metamyetocytes and on the convex or concave faces of the C‐shaped Golgi stacks of mature neutrophis.

Using the cis‐osmiophilic‐element as a marker of the cis‐face of the stackedGolgi elements, it thus appeared that despite marked changes in the configuration and orientation of the stacks the cis‐trans polarity of the stacked elements was maintained throughtout granulopoiesis. In addition the primary and secondary granules that appeared sequentially in promyelocytes and myelocytes were both seen to form in relation to trans‐elements of the Golgi apparatus.
Ultrastructural cytochemistry of aortic microfibrils in the arctic lamprey, Lampetra japonica
Authors: Isokawa Keitaro , Takagi Minoru , Toda Yoshihisa
Published: February 2005

In the ventral aorta of lamprey, microfibrils are major components of the extracellilar matrix. With special refeence to these microfibrils, we have cytochemically exmined the ventral aorta, utilizaing the tannic acid (pH 7.0)‐uranyl acetate (TA‐UA) method, elastase en bloc digestion, Thiéry's periodis acid‐thiocarbohydrazide‐silver proteinate (PA‐TCH‐SP) method, and ferritin‐ or horseradish peroxidase‐labeledd concanacalin A (Con A) methods. The lamprey microfirils were strongly stained with PA‐TCH‐SP and both Con A methods, but did not show TA‐UA staining nor elastase sensitivity. These cytochemical properties of lamprey microfibrils are identical with those of mammalian elastin‐associated microfibrils. On the other hand, in spite of extensive examination, TA‐UA positive and elastase‐sensitive extracellular components were not found, so that lamprey ventral aorta does not appear to contain elasin. These results indicate that lamprey lamprey aortic connective tissue contains microfibrils as elastic components, but deposition of amorphous elastin dose not occur.
Effect of selected denervations on glycoconjugate composition and tissue morphology during the initiation phase of limb regeneration in adult Ambystoma
Authors: Young Henry E. , Dalley Bernell K. , Markwald Roger R.
Published: February 2005

This study was undertaken to assess the effects of various quantities of neural tissue on the temporal relationship of matrix glycoconjugates to the regeneration morphology. 1) Denervation before amputation revealed that a threshold level of nervous tissue was necessary to activate a regeneration response from the tissue, i.e., appearance of regeneration‐specific morphologies and glycoconjugates. 2) Denervation after amputation demonstrated that the level of neural tissue necessary to maintain these responses was below the level necessary to activate the regeneration response. If neural tissue was completely removed there was a concomitant loss of regenerate morphologies and glycoconjugates. 3) Bilateral amputation of a neurogenically intact limb and its completely denervated contralateral limb revealed that the regeneration response was a localized phenomenon during the first 30 days after amputation. After 30 days the regeneration response appeared within the previously degenerated denervating limb. The results suggest that the factors controlling the regenerative response in adult Ambystoma are large diffusible substances that can be transported by the circulation and can affect the regenerative response in remote, previously activated, tissues.
Effects of aging on the neurons within area 17 of rhesus monkey cerebral cortex
Authors: Vincent Stephen L. , Peters Alan , Tigges Johannes
Published: February 2005

A light and electron microscopic examination of area 17 of the visual cortex in well‐fixed young (5‐6 years) and old (25–35 years) rhesus monkeys was carried out to determine the effects of age on neurons. The analyses were made in a portion of area 17 on the lateral surface of the hemisphere just caudal to the lunate sulcus. Light microscopic measurements of the mean cortical depth in vertically oriented 1‐μ‐thick sections reveal no obvious thinning with age, and the mean diameters of neuronal nuclei do not change with age. On the basis of counts of neuronal profiles containing nuclei in 250‐μ‐wide strips of 1‐μ‐thick sections passing through the entire depth of the cortex, no significant neuronal loss could be detected. These findings are consistent with our electron microscopic observations on this area of the cortex, for in the old monkeys the neurons show little cytological evidence of advanced age beyond the presence of a few lipofuscin granules, although the neuropil contains some profiles of degenerating small‐caliber dendrites, myelinated axons, and a few axon terminals. Large vacuoles, some 10 μm or more in diameter, are present in the neuropil of the old animals. Some of these vacuoles appear to represent a late stage in the degeneration of myelinated axons, for they are bounded by a thin, laminated sheath. Other large vacuoles, of unknown origin, often contain membranous debris and have an attenuated limiting membrane. It is concluded that the cell bodies of neurons in area 17 of old rhesus monkeys do not show singificant structural changes due to age, although some of the neuronal processes in the neuropil are affected.
Foveal regions of bird retinas correlate with the aster of the inner nuclear layer
Authors: Inzunza Oscar , Bravo Hermes , Smith Ricardo L.
Published: February 2005

A radiate specialization, the aster, has been found in whole‐mount retinas of birds and is associated to each one of the temporal and nasal fovea, with the one related to the convexiclivate nasal fovea more evident. This radial arrangement extends uniformly in all directions from the foveal pit. Transverse sections of the retina show that this structure is formed by bands of cells and bundles of fibers from the inner nuclear layer.
Acridine orange‐RNA fluorescence of maturing neurons in the perinatal rat brain
Authors: Topaloglu Haluk , Sarnat Harvey B.
Published: February 2005

Cytoplasmic RNA was demonstrated in neurons of the developing rat brain using acridine orange (AO) as a histochemical marker. Fetuses of 18 days and postnatal rats of 1, 7, 14, and 21 days as well as adults several months old were studied. Neuroblasts of the germinal matrix exhibited minimal or no orange‐red AO‐RNA fluorescence, but immature nerve cells in migration within the cerebral hemispheres of the rat showed a weak but definite orange colour. This finding contrasts with the absence of AO‐RNA fluorescence in migrating human neuroblasts. Neurons of the neocortical plate showed uniformly strong fluorescence. In the hippocampus, the most pronounced increase in AO‐demonstrated RNA was in pyramidal and granule cells during the first postnatal week. The cerebellum showed a paradoxically stronger fluorescence of granule cells in the 18‐day fetus than at birth, and almost no AO‐RNA fluorescence of granule cells at 21 days of age or in adults. Motor neurons showed the strongest fluorescence of all neurons. It is likely that the increase in cytoplasmic RNA in neurons corresponds to the onset of neurotransmitter biosythesis, but transitory fetal neuropeptides may explain stronger fluorescence of some neurons in young individuals. The reliable and simple AO method provides a supplementary means of studying one aspect of neuronal maturation.
Biophysical aspects of lipid interaction with mineral: Liposome model studies
Authors: Eanes Edward David
Published: February 2005

The present paper reviews the use of liposomes as synthetic models for studying various biophysical aspects of matrix vesical calcification, especially the involvement of acidic phospholipids in the nucleation and growth processes which occur during the initial stages of mineral formation in and around these membrane‐bound structures. Recent results showed that acidic phospholipids incorporated into phosphatidylcholine‐rich anionic liposome membranes were ineffective in initiating extraliposomal calcium phosphate precipitation from metastable solutions at physiological pH. On the contrary, certain acidic phospholipids such as phosphatidic acid and phosphatidylserine retarded the development of such precipitation when the latter was endogenously induced. The extent of inhibition correlated with the strength of the electrostatic interaction between the polar head group of the acidic phospholipid and the surface of the mineral phase. The results suggest that acidic phospholipids may play an important role in controlling the rate of early mineral development in matrix vesicle calcification.
Multinucleated cells formed on calcified dentine from mouse bone marrow cells treated with 1α,25‐dihydroxyvitamin D3 have ruffled borders and resorb dentine
Authors: Sasaki Takahisa , Takahashi Naoyuki , Higashi Shohei , Suda Tatsuo
Published: February 2005

Osteoclast‐like multinucleated cells were formed from mouse bone marrow mononuclear cells, and their morphology on coverslips and on calcified dentine slices was compared by means of transmission electron microscopy. Addition of 1α,25‐dihydroxyvitamin D3 [1α,25(OH)2D3] to bone marrow cells cultured on coverslips greatly stimulated the formation of multinucleated cells within 8 days. These multinucleated cells had the cytological features of osteoclasts (abundant pleomorphic mitochondria, a large number of vacuoles and lysosomes, many stacks of Golgi membranes, and an extensive canalicular system), but they developed neither ruffled borders nor clear zones. The multinucleated cells appeared to result from direct fusion of mononuclear progenitor cells, whose structural features were similar to those of multinucleated cells. Like isolated osteoclasts, both multinucleated cells and their precursors exhibited an intense reaction for tartrate‐resistant acid phosphatase (TRACP) in the cisterns of endoplasmic reticulum and lysosomes. Multinucleated cells formed from alveolar macrophages in the presence of 1α,25(OH)2D3 were totally negative for TRACP reaction. When marrow cells were cultured on dentine slices in the presence of 1α,25(OH)2D3, some of the multinucleated cells were located in the shallow resorption lacunae of dentine surfaces, and they developed the characteristic ruffled borders and clear zones. The narrow extracellular spaces of the ruffled borders, the adjacent pale endocytotic vacuoles, and the dark lysosomes located in the perinuclear cytoplasm of the multinucleated cells contained numerous apatite crystals delete in resorption lacunae. These results indicate that (1) the multinucleated cells formed on coverslips from mouse marrow cells treated with 1α,25(OH)2D3 exhibit non‐functional basic features of osteoclast morphology, and (2) differentiation of the multinucleated cells into functional osteoclasts requires some components of calcified dentine.
Vasoconstriction in Telencephalic Microvessels: A Response to One Model for Intraventricular Hemorrhage in Beagle Pups
Authors: Leuschen M. Patricia , Nelson Robert M.
Published: February 2005

Telencephalic microvessels were morphologically and morphometrically evaluated in beagle pups at 24, 48, and 72 hours of age following an experimental insult consisting of exposure to acute hypovolemic hypotension followed by rapid corrective blood reinfusion. Animals were anesthetized throughout the procedure and maintained for 75 minutes prior to sacrifice. Microvessels from the germinal matrix, where intraventricular hemorrahge (IVH) most commonly occurs, were compared to those of the adjacent cerebral cortex and choroid plexus. Perfusion, fixation and processing of the tissue followed our previously published protocol (Leuschen et al.: Anatomical Record 208:435–443, 1984). Both germinal matrix and cortical microvessels had collapsed lumens and normal endothelial cell morphology; mitochondria contained distinct cristae, junctional complexes were present and a basement lamina completely surrounded most vessels. Morphometric data on matrical and cortical microvessels supported vasoconstriction. Microvessels from choroid plexus were not vasoconstricted; tight junctions were infrequently seen and microvesicular elements were present. An increased cerebral blood flow to the germinal matrix and the adjacent cerebral cortex has been reported during and immediately following hypovolemic hypotensive insult. Insult. By 75 minutes following insult, our ultrastructural studies support a rebound phenomena including vasoconstriction of microvessels. The resulting vasocontriction and associated cerebral ischemia may play an important role in subsequent tissue damage to the matrical area and ultimately to the etiology of IVH.
The morphology of release of vitamin A‐containing lipid droplets by hepatocytes in rat liver
Authors: Kudo Shigeharu
Published: February 2005

Vitamin A‐containing lipid droplets in the hepatocytes of rat liver were found to be exocytotically released from the cells in the form of a “lipid droplet—retinol‐binding protein (RBP)—immunoreactive complex” following intraportal injection of retinol (17, 33, 67, or 100 μg). Evidence that the lipid droplets contain vitamin A was obtained by fluorescence microscopy of vitamin A. Intraportal injection of retinol produced varied numbers and sizes of vacuoles in the hepatocytes. The substance within the vacuoles exhibited a meshwork‐like configuration in sections from slices incubated in a medium for revealing acid phosphatase activity or the corresponding control medium and was RBP‐immunoreactive and proteinaceous in nature. The occurrence and number of the vacuoles depended on the dosage of injected retinol, being greatest at a dosage of 100 μg of retinol and becoming progressively less at dosages of 67, 33, and 17 μg. The vacuoles were formed by vacuolization of cisternae of the rough endoplasmic reticulum. The formation of vacuoles reached a maximum 30 min after intraportal injection of 100 μg retinol, and the vacuoles and lipid droplets had almost disappeared from the hepatocytes after 90 min. Little or no esterase activity was found in lipid droplets in the hepatocytes before intraportal injection of retinol, but after the injection, lipid droplets that had fused with the vacuoles become strongly positive for this enzyme activity. This suggests that hydrolysis of retinyl esters may occur in the process of complex formation in rat hepatocytes.
In vitro reconstruction of a cartilage matrix granule network
Authors: Phillips Frank M. , Pottenger Lawrence A.
Published: February 2005

The cartilage extracellular matrix contains electron‐dense granules and fine filaments when studied electron microscopically after staining with ruthenium red. The matrix granules contain proteoglycans, while the filaments are thought to represent hyaluronic acid. In the present study partial extraction of proteoglycans from the cartilage prior to staining reduced the density of matrix components to allow visualization of a well‐developed network involving the matrix granules and hyaluronic acid filaments. The matrix granules frequently had multiple filamentous attachments and the network appeared to be formed by intersecting filaments with the matrix granules at points of intersection. A similar network was created in Sepharose CL‐2B beads when proteoglycans, link proteins, and hyaluronic acid were concentrated in the beads. Elimination of any one of these components resulted in failure to form a complete network. Purified proteoglycan monomers alone were sufficient to create matrix granules in the beads. Filaments were seen only when hyaluronic acid was added to the beads. The nature of the network suggests that some type of association between separate aggregates is occurring both within cartilage and within the Sepharose CL‐2B beads.
Effects of hypofunction on the distribution of 3H‐proline in the transseptal fibers of the periodontium of the rat
Authors: Johnson Roger B.
Published: February 2005

There is little information concerning the effect of altered occlusal forces on the turnover of collagenous proteins of transseptal fibers of the periodontium. In the present study, hypofunction was induced in rats by extraction of the maxillary teeth, allowing the mandibular teeth to supererupt (hypofunctional side, herein). The contralateral side served as an internal control, although it was likely experiencing occlusal hyperfunction (hyperfunctional side, herein). Untreated animals were also studied (external controls, herein). Animals were injected with 3H‐proline and silver grains were counted on radioautographic preparations. The study demonstrated significant differences in the synthesis and degradation of collagenous proteins coincident to altered occlusal function; 3H‐proline was most heavily incorporated into the transseptal fibers of hyperfunctional and least rapidly into the external control tissues (P<.001). Significant differences in grain counts were evident during the first 3 weeks after injections. Collagenous proteins were degraded most rapidly in transseptal fibers of the hyperfunctional and least rapidly in hypofunctional tissues (P<.001). The study also demonstrated regional variability in the turnover of labeled collagenous proteins, that is, proteins were synthesized and degraded most rapidly in the middle third and least rapidly in the mesial third of the ligament (P<.001). “Whole” counts (mean of counts over middle, mesial, and distal thirds) were not similar to those of any specific region and could provide erroneous information concerning remodeling of collagenous proteins of transseptal fibers. Transseptal fibers, labeled by the 3H‐proline pulse, migrated occlusally with the teeth; new transseptal fibers and bone were formed at the crest of the interdental septum.
Cell distribution in tracheal surface epithelium and the effects of long‐term pilocarpine and atropine administration
Authors: Gatto Louis A.
Published: February 2005

Cell distribution and the effects of 12 daily injections of 80 mg/kg pilocarpine or 5 mg/kg atropine were studied in rat tracheal epithelium. Ciliated, periodic‐acid‐Schiff‐positive (PAS+), Alcian blue‐positive (AB+), nonstaining, and basal cells were counted and their order of occurrence was recorded. Pilocarpine caused a decrease in ciliated and an increase in PAS+, basal, and nonstaining cell numbers. Atropine caused similar changes, although to a much lesser extent. AB+ cells were rare. Cell occurrence was randomized by computer, and comparisons with nonrandomized counts were made to discern between 1) differences in cell arrangement owed to variations in cell numbers, and 2) actual biases in cell distribution. In general, ciliated areas amounted to a few cells and were separated by nonciliated patches of comparable size. The grouping characteristics of cells supported the notion that basal cells were surrounded by their progeny and that daughter cells were displaced by siblings. It was concluded that the cells were not randomly distributed. Basal cells were dispersed, and probably immediately related to PAS+ cells but not to ciliated cells. A bias toward grouping implied concurrent differentiation of clusters of sibling cells. With drug treatment, a substantial increase in PAS+ cells without increase in cell concentration suggested a decrease in ciliated cell differentiation. Larger groups of secretory cells with treatment suggested cell division without differentiation through the basal cell pathway. Cholinergic agents were not the predominant modulators of this epithelium, and their effect was probably secondary to influence over mucociliary function.
Technique for estimating fetal mouse thoracic volumes through image analysis of histological sections
Authors: Bradford Hepworth W. , Carter Melvin W. , Seegmiller Robert E.
Published: February 2005

In a previous study we estimated fetal mouse thoracic volume by use of paraffin casts. While this procedure provided useful information, it did not allow histologic examination of thoracic viscera. In the present study the thoracic volumes of day 14–18 fetal mice were determined through serial histological sections. The thoracic cavity was traced from the sections and the area of each tracing was determined by computer image analysis. These areas were summed and then multiplied by the thickness of each section to derive the thoracic volume. This procedure thus permitted both volumetric determinations and histological inspection of the thoracic viscera. In addition, two randomized sampling methods designed to increase the utility of such volumetric estimates were compared for reliability. The method best suited for this study was a random stratified sampling method because it reproduced estimates with minimal standard deviation.
Circaseptan (about 7‐day) modulation of circadian rhythm in corneal mitoses of holtzman rats
Authors: Tsai T. H. , Scheving L. E. , Sánchez De La Peña S. , Marques N. , Halberg F.
Published: February 2005

An infradian modulation with a 168 h or circaseptan period characterizes epithelial corneal mitoses in adult female and male Holtzman rats, standardized at 24 ± 1°C and ∽50% relative humidity on six different sequences of light (L) alternating every 12 h with darkness (D). To approximate sampling over a 24 h LD span by convenient sampling within a single hour, the LD 12:12 regimen was staggered by 4 h in the six environments. Bedding was changed 3 days before each day of killing. During each of eight or 12 consecutive days, male and female rats, respectively, were killed and the eyeballs were removed. Mitotic indices in the cornea were determined separately for each eye and the data were analyzed by linear and nonlinear least‐squares rhythmometry. For a prominent circadian component of mitotic activity, the 95% confidence interval (CI) of the period extends from 23.6 to 24.3 h for the data from males and from 23.7 to 24.2 h for those from female rats. The circadian amplitude is larger in males as compared to females. The peaks in the 24 h cosine functions best approximating the data, the circadian acrophases, are at −64° or −48°, i.e., 4 h 16 min or 3 h 12 min from lights‐on in male and female rats, respectively. In the data from the two genders, the 24 h synchronized circadian acrophases are thus only 16°, i.e., 1 h and 4 min apart. A test for an anticipated circaseptan (7‐day) period shows that this particular infradian periodicity is superimposed upon the circadian one in data from both genders. A circasemiseptan, about‐half‐weekly (84 h), period is also found in data from the rats of both genders. In the spectral region examined, the circadian component predominates in amplitude over infradians. As a whole, the circadian‐infradian modulation of corneal mitosis need no longer remain a large, unassessed source of variation. Instead, it is a newly resolved multifrequency time dimension of the organism, apparent in health in the basic process of cell division. The underlying multiple rhythmic intermodulations at several frequencies among neuroendocrine coordinators of physiologic function, the feedsideward mechanisms, can now be studied in Holtzman as well as Lewis rats in the light of the temporal mitotic reference standards described herein.
Demonstration by lectin‐gold cytochemistry of transfer of glycoconjugates of oviductal origin to the zona pellucida of oocytes after ovulation in hamsters
Authors: Kan Frederick W. K. , Roux Emmanuelle , St.‐Jacquesz Sylvie , Bleau Gilles
Published: February 2005

We have previously localized an antigen of oviductal origin to the zona pellucida of superovulated hamster oocytes (Kan et al.: Journal of Histochemistry and Cytochemistry 36:1441—1447, 1988) and described the intracellular distribution of this antigen in the oviductal epithelium (Kan et al.: Biology of Reproduction 40:585—598, 1989). These results led to our hypothesis that the oviduct is a bona fide site of origin of certain components of the zona pellucida. In this report, using the high resolution lectin‐gold approach with Helix pomatia lectin (HPL)‐colloidal gold complex, we present cytochemical evidence to show that glycoconjugates containing terminal N‐acetyl‐D‐galactosamine residues are absent from the zona pellucida of ovarian oocytes but are synthesized and secreted by the nonciliated secretory cells of the oviduct and later become associated with well‐defined structural elements of the zona matrix of oocytes during passage through the oviduct. The nature of the HPL‐binding glycoconjugates was determined by biochemical analyses. Electrophoretic and immunological experiments demonstrated that the glycoconjugates correspond to the high molecular weight polydispersed glycoprotein that we have previously described. We have designated this glycoprotein “hamster oviductin 1” (IIm OV‐1). Our results further substantiate the belief that the oviduct is a source of origin of zona pellucida constituents.
Distribution of cell surface glycoconjugates during secondary neurulation in the chick embryo
Authors: Griffith C. M. , Wiley M. J.
Published: February 2005

Lectin histochemistry was used to examine the expression of cell surface glycoconjugates during secondary neurulation in chick embryos. Fourteen lectins were applied to serial sections of the caudal region of embryos at the various stages of tail bud development. The lectins Bandeiraea simplicifolia, Dolichos biflorus agglutinin, Phaseolus vulgaris leukoagglutinin, soybean agglutinin, Sophora japonica agglutinin, Ulex europaeus agglutinin and succinylated wheat germ agglutinin (sWGA) showed very light or no binding to the developing medullary cord of the tail bud. With the other lectins, staining occurred throughout the early tail bud and solid medullary cord. During cavitation, however, differential expression of cell surface glycoconjugates by different cell populations was observed. The lectins concanavalin A, Lens culinaris agglutinin, Pisum sativum agglutinin, Phaseolus vulgaris erythroagglutinin, Ricinus communis agglutinin and WGA showed basic similarities in the distribution of lectin binding. Of these, the binding pattern of WGA was the most striking. As the medullary cord cells were separating into central mesenchymal and peripheral epithelial populations, WGA bound preferentially to the epithelial cells and the notochord. The lectin PNA, however, became preferentially bound to the mesenchymal cells. Heavy staining by WGA (specific for N‐acetylglucosamine and sialic acid) where sWGA staining (specific for N‐acetylglucosamine only) was faint suggested that WGA binding was due to the presence of sialic acid containing glycoconjugates.
Retrograde trafficking of tracer protein by the internal ovarian epithelium in gravid goodeid teleosts
Authors: Schindler Joachim F.
Published: February 2005

Gravid goodeid females harbor embryos in a preformed ovarian cavity for prolonged periods of gestation. Various nutrients for embryonic growth are provided by the internal ovarian epithelium (IOE). Its cells flatten during late stages of gestation and form an attenuated layer of cytoplasm covering a dense network of protruding capillaries, with the nuclear domains mostly recessing between the vascular meshes. The IOE in both Xenotoca eiseni and Girardinichthys viviparus exhibit morphological features associated with vesicular transport of macromolecules. The amounts of rough endoplasmic reticulum in the IOE cells seem insufficient to effectively synthesise proteinaceous secretions. Apparently, it rather serves as a transit route for serum‐derived products.

Cationized ferritin (CF) was injected into the ovarian cavity of gravid females. The electrostatic ligand spotwise attached to the luminal surface of the IOE and gained access by adsorptive micropinocytosis. Many tracer molecules were sequestered into lysosome‐like vacuoles that became increasingly swollen after prolonged incubation intervals. In addition, CF traversed the IOE within small vesicles. At the basal pole of the cells the contents of transcytotic vesicles were evacuated, and localization of small CF‐clusters was regularly in the basement lamina, in the underlying connective tissue, in vacuoles within migrant cells, in vesicular compartments of the capillary endothelia, in capillary lumina, and in intravascular leucocytes. Tracer molecules were never observed to enter stacked Golgi cisternae. Since the cationic marker probably follows retrograde pathways of the protein secretion, the experimental data support the morphologically derived conclusions that postulate a major role for the IOE in transepithelial transport.
Harderian gland and the lacrimal gland of the lizard Podarcis s. sicula: Histology, histochemistry, and ultrastructure
Authors: Baccari Gabriella Chieffi , Minucci Sergio , Matteo Loredana Di , Chieffi Giovanni
Published: February 2005

Histology, histochemistry, and ultrastructure of the Harderian gland and lacrimal gland of the lizard Podarcis s. sicula were investigated. The Harderian gland, located at the medial corner of the orbit, can be divided into three zones showing different tinctorial features either with Mallory or hematoxylineosin stains. The glandular cells of the acinar medial zone secrete predominantly acidic sulphated mucosubstances. The acinar cells of the intermediate zone contain secretory granules that show a weak reaction to the histochemical tests for mucosubstances. The lateral zone has a tubulo‐acinar type of structure and tests strongly for proteins, whereas Alcian‐PAS staining is very weak. The lacrimal gland is smaller than the Harderian gland and lies in the region of the posterior commissure of the eyelids. It shows the same histological and histochemical characteristics of the medial zone of the Harderian gland, i.e., it is mucous secreting. At the ultrastructural level the zonation is well defined, especially when the secretory granules are examined. Granules of the mucoid type are found in the lacrimal gland and the medial zone of the Harderian gland. The secretory granules of the lateral part of the Harderian gland show a composite structure never described before. Therefore, they have been called “special secretory granules”. Each of these granules is composed of three sharply separated components. It is not known whether the three components correspond to different secretions. Histochemical tests suggest that they are of the serous type. Both mucous and serous granules are secreted by the same glandular cells of the intermediate zone of the Harderian gland. The two types of granules usually occupy different cell compartments. The mechanism of secretion appears either merocrine or apocrine in both the Harderian gland and the lacrimal gland.
Remission of the polycystic ovarian condition (PCO) in the rat following hemiovariectomy
Authors: Convery Margaret , McCarthy Gerald F. , Brawer James R.
Published: February 2005

The estradiol valerate‐induced polycystic ovarian condition in the rat represents a normal ovarian response to aberrant endocrine stimuli. Although we have shown that removal of one polycystic ovary (hemiovariectomy) results in restoration of cyclicity and normal morphology in the remaining ovary by 1 week, nothing is known about the process of recovery or about the role of the hypothalamopituitary unit in initiating recovery. We have therefore examined ovaries at 3, 12, 24, 48, and 120 hours following removal of the contralateral polycystic ovaries. The ovarian content and size distribution of healthy and atretic follicles was determined, as well as the occurrence of follicular cysts, type III large follicular structures, and corpora lutea. The plasma LH pattern was also examined at a short postoperative interval. At 3 hours, there was a significant increase in mean ovarian weight that coincided with the emergence of healthy large secondary follicles. By 12 hours, there was a significant sustained diminution in the number of atretic follicles of all sizes, but the total number of healthy follicles did not increase significantly until 120 hours. The cystic follicles had all but disappeared by 120 hours because of mechanical compression by newly developing ovarian tissue. Ovarian recovery is, therefore, biphasic, consisting of a very early diminution in atresia coincident with, and perhaps caused by, a major alteration in the plasma LH pattern. The second phase is characterized by a wave of follicular recruitment and development.
Morphometric analysis of thoracic muscles in wildtype and in bithorax Drosophila
Authors: Egger M. David , Harris Suzan , Peng Bonnie , Schneiderman Anne M. , Wyman Robert J.
Published: February 2005

The tergotrochanteral (TTM) “jump” muscles in the second (T2) and third (T3) thoracic segments of the fruit fly, Drosophila melanogaster, were analyzed morphologically and morphometrically in wildtype (Canton‐S) and bithorax mutants (abx bx3 pbx / Df(3R)P2). In the transformed T3 segments of mutant flies, the TTMs were greatly increased in fiber number (330% of wildtype), length (141%), and volume (460%), thus manifesting both hyperplasia and hypertrophy. In contrast, TTMs in the “untransformed” T2 segments of mutant flies were both hypoplastic and hypotrophic, in that significant decreases in fiber number (93% of wildtype), length (90%), and volume (80%) were observed.

Two relationships emerged from analysis of the morphometric data: (1) Although the fiber numbers and volumes of the transformed T3 TTMs in bithorax flies were greatly increased, the total combined volumes of the TTMs in T2 + T3 remained approximately the same in bithorax compared to wildtype flies. (2) The changes in TTM volumes in bithorax flies compared to those in wildtype were proportional to the relative changes in fiber numbers times the relative changes in muscle lengths. These observations suggest that the genes of the bithorax complex influence the number and the length of tubular muscles fibers of the TTMs, but do not significantly affect the mean cross‐sectional areas of these fibers.

Fibrillar muscle fibers, which are not found at all in T3 segments in wildtype flies, were observed in the transformed T3 segments of bithorax mutants in 11 of 18 cases (61%), but typically as wisps, not in complete muscles. We suggest that, in the T3 segment of the bithorax flies, the relative differences between the massive transformation of tubular TTMs vs. the minimal appearance of fibrillar muscles may be related, in part, to the relative availability of muscle precursors.
X‐chromosome monosomy in the myelin‐deficient rat mutant
Authors: Rosenbluth J. , Perle M. A. , Shirasaki N. , Hasegawa M. , Wolf M. E.
Published: February 2005

We have identified three examples of female Wistar rats exhibiting the tremor and seizures characteristic of the X‐linked myelin deficiency (md) mutation, which is ordinarily seen only in males. Cytogenetic study of two of these animals has shown them to have 41 chromosomes instead of the normal 42. The missing chromosome was identified as an X chromosome by G‐banding analysis. These animals thus have an XO genotype comparable to that in Turner's syndrome. Anatomically, one of the animals, which was studied in detail, showed no abnormality of the uterus, and the ovaries, although somewhat smaller than normal, were histologically indistinguishable from those in a normal female rat. No evidence of endocardial fibroelastosis was detected, nor was there any anomaly of the aorta. The myelin deficiency in the central nervous system was comparable to that in hemizygous mutant male rats. XO monosomy in the Wistar rat thus has little effect on phenotype and is more comparable to that in mice than to Turner's syndrome in man. The myelin‐deficient rat is useful for studies of X‐chromosome monosomy since XO females can readily be identified by the neurological syndrome characteristic of the md mutation.
Distribution of laminin in the murine pituitary
Authors: Nunez Eladio A. , Pomeranz Howard D. , Gershon Michael D. , Payette Robert F.
Published: February 2005

The distribution and cellular localization of the glycoprotein laminin were investigated by light and electron microscopic immunocytochemistry in the adult murine pituitary gland. Immunoblots confirmed that laminin was the only protein in the pituitary gland of the adult male mouse to react with antilaminin serum. Laminin immunoreactivity was demonstrated at the light microscopic level simultaneously with that of β‐follicle stimulating hormone (β‐FSH) and β‐luteinizing hormone (β‐LH). In addition to its distribution is basal laminae, laminin immunoreactivity was coincidently expressed in gonadotrophs with the immunoreactivities of β‐FSH and β‐LH. Electron microscopic immunocytochemistry was employed on aldehyde‐fixed sections embedded in L.R. White. Sites of binding of primary antisera to laminin were identified with affinity‐purified secondary antisera directly coupled to 20 nm particles of colloidal gold. Three antisera recognizing laminin were compared and found to result in an identical pattern of immunoreactivity. Laminin was found extracellulary only in formed basal laminae in all three lobes of the pituitary and was not found in extracellular matrices of connective tissue. Laminin immunoreactivity was also found intracellularly in gonadotrophs but in none of the other endocrine or non‐endocrine cells of the anterior lobe. Within gonadotrophs, only secretory granules were labeled. The majority, but not all, secretory granules were labeled in each of the gonadotrophs examined, and the proportion of granules labeled with laminin could not be increased by doubling the concentration of anti‐laminin serum. Laminin immunocreactivity segregated with the subset of secretory granules containing β‐FSH. In contrast, laminin immunoreactivity was absent in the smaller subset of secretory granules that contain serotonin. No secretory granules were labeled within the endocrine cells of the intermediate lobe, nor within secretory granules of neural elements in the posterior lobe.
Golgi tendon organs in the proximal tendon of sheep extraocular muscles
Authors: Ruskell G. L.
Published: February 2005

Sheep extraocular muscles were prepared for light and electron microscopy and their proximal tendons searched for Golgi tendon organs (GTO). An extensive aponeurotic lamina on the orbital surfaces contained numerous GTO 250–1350 μm in length with characteristic terminal form and relationship with collagen. They differed from usual GTO structure in containing large fluid‐filled spaces dividing collagen into several well separated compartments and a muscle fiber entered and terminated in about one third of the receptors. The fibers, Felderstruktur in type, often penetrated deep within tendon organs, and in a few instances two or more fibers entered. This feature is shared by the rare GTO of monkey extraocular muscles.

That the presence of GTO in the proximal tendons of extraocular muscles is previously unrecorded may be attributed to the practice of restricting attention to the long distal tendons. The possibility that receptors may be so placed in other species warrants further work especially in those purported to lack any receptor.
Immunochemical localization of Clara cell protein by light and electron microscopy in conducting airways of fetal and neonatal hamster lung
Authors: Strum Judy M. , Singh Gurmukh , Katyal Sikandar L. , McDowell Elizabeth M.
Published: February 2005

An antibody to a protein produced by Clara cells in adult Syrian golden hamsters has been used to monitor the development and functional differentiation of secretory cells in the conducting airway epithelium of this species. Lungs from fetal and neonatal hamsters at gestational day 11 and at intervals up to and including 3.5 weeks of age (as well as adults) were studied. The earliest time this Clara cell protein could be identified by immunoperoxidase labeling in the fetal conducting airways was at gestational day 15. On this day, labeling was observed in a few secretory cells lining the trachea, in many lining the lobar bronchi, and in virtually all secretory cells lining the bronchioles. Ciliated cells and endocrine cells were not labeled. Granules first appeared within the apical cytoplasm of the secretory cells on gestational day 15 at all airway levels. To identify the exact subcellular location of this protein, an ultrastructural labeling procedure using protein A gold was employed. The gold particles labeled only electron‐dense granules within the secretory cells, indicating that they represent the specific site of this protein. Since secretory cells in the most distal conducting airways began to produce this protein on the same day in development as cells in the larger airways, including the trachea, this expression of functional maturation occurs simultaneously throughout the conducting respiratory tree rather than proceeding sequentially in a cranial to caudal direction. Consequently, secretory cells lining the smaller conducting airways mature more rapidly than those lining the larger airways.