bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ultrastructural quantitative analysis of the innervation of axillary lymph nodes in juvenile and old rats
Authors: Novotny G. E. K. , Schöttelndreier A. , Heuer T. 
Published: February 2005

AbstractBackground: Earlier studies have shown that the innervation of axillary lymph nodes is increased in old animals, compared to juvenile rats. The question thus arose, whether changes are also observable at an ultrastructural level for varicosities which form the actual transmission units.Methods: Ensheathed (axons) and unensheathed axonal profiles (open areas), were quantified with their spatial relationships to cells at the ultrastructural level in the axillary lymph nodes of juvenile ( < 6 weeks) and old ( > 2 years) Wistar rats.Results: In both groups of animals the majority of open areas, irrespective of their content of vesicles, lie at distances of more than 1,000 nm from cells in the plane of the section. Almost all open areas, located within 1,000 nm of a cell, are related to reticular cells, a small minority to plasma cells, and even fewer to lymphocytes. In the old animals there is a highly significant increase in the total number of sections of open areas with and without vesicles per unit area of medulla. The number of open areas related to cells does not change significantly in the old animals, as also the percentage of profiles containing vesicles. Only the percentages of open areas with and without vesicles related to plasma cells increase significantly in the old animals. This change is paralleled by a highly significant increase in the percentage volume of plasma cells in the old animals. On average, the profiles related to cells are closer to the cells in the older animals.Conclusions: The observed changes indicate that the innervation of lymph nodes of the rat is absolutely increased in the old animals, but that the relations between the various categories of profiles and their relations to cells tend to remain constant. © 1995 Wiley‐Liss, Inc.
Ontogeny of sensory nerves in the developing skeleton
Authors: Sisask G. , Bjurholm A. , Ahmed M. , Kreicbergs A. 
Published: February 2005

AbstractBackground: Previous studies have shown that the neuropeptide calcitonin gene‐related peptide (CGRP) have an influence on osteoclastic bone resorption and that CGRP and substance P (SP), both wellknown markers for sensory neurons, behave as growth factors.Materials and Methods: The ontogeny of the sensory nerves in the hindlimb skeleton of the rat was studied from gestational day (GD) 15 to neonatal day (ND) 24 by immunohistochemistry. Neurofilaments and nerve terminals were labelled with protein gene‐product 9.5 (PGP 9.5) and synaptophycin (SYN) respectively.Results: PGP 9.5 appeared at GD 15 and SYN at GD 19, both in the perichondrial tissue of the long bones. One week later, at ND 4 nerve fibre, immunoreactive to PGP 9.5 and SYN were observed within the bone organ. Sensory nerves, indicated by CGRP and SP, were first discerned at GD 18–19 in the periosteal tissue of the diaphyseal and metaphseal regions and in the bone organ at ND 4. Approximately at ND 6, vascular as well as non‐vascular nerves extended into the metaphyses and at ND 8 into the epiphyses, concomitant with the first signs of mineralization.Conclusions: The study shows that a functional sensory nerve supply of the developing bone organ occurs immediatly prior to partus, apparently parallel with an increasing mineralization. The combined findings may indicate a sensory influence on developmental processes in the skeleton. © 1995 Wiley‐Liss, Inc.
Thyroid gland development in the brushtail possum, Trichosurus vulpecula
Authors: Buaboocha W. , Gemmell R. T. 
Published: February 2005

AbstractBackground: The onset of thyriod function occurs at different times with respect to birth in different mammals. In most marsupials studied thus far, thyroid function begins during the latter half of pouch life. However, in marsupials, thyroxine can be transported from the mother to the young via milk. In this study the plasma concentration of the thyroid hormones, thyroxine (T4) and triiodothyronine (T3), in the young was correlated with the ultrastructural appearance of the thyroid of the young.Methods: Thyroid glands at 40, 65, 70, 96, 113, 115, and 129 days postpartum and from an adult were examined with the light and electron microscope. Plasma concentrations of both T4 and T3 in young possums were determined by radioimmunoassay.Results: Plasma concentrations of T4 in the young were less than 10 ng/ml prior to day 60 and 12 ng/ml on day 60; they rose to a peak of 45 ng/ml on day 120 postpartum and then diminished to below 10 ng/ml by day 160 postpartum. Plasma T3 concentrations were similar in profile, the peak concentration being 0.25 ng/ml on day 120 postpartum, and, as with T4, T3 concentrations decreased in the latter part of the lactation period. The morphology of the follicular cells of the thyroid gland would suggest that the developing brushtail possum is capable of producing thyroxine at about day 65 postpartum. Densely staining bodies, presumably lysosomes that are required for the conversion of thyroglobulin to thyroxine, were first seen on day 65, and greater quantities were noted in day 96, 113, 115, and 129 thyroid tissue.Conclusions: The plasma concentrations of T4 and T3 of the young are greater than that of the adult by day 60 postpartum, with peak concentrations of thyroid hormones on day 120 postpartum. Ultrastructural examination would suggest that the possum thyroid gland is capable of producing thyroid hormones at about day 65 postpartum. The activation of the thyroid gland precedes the reported increase in growth rate of the young possum on day 96 (Gemmell and Hendrikz, 1993. Aust. J. Zool., 41:141 – 149 ). © 1995 Wiley‐Liss, Inc.
Venous structures associated with thermoregulation of phocid seal reproductive organs
Authors: Rommel Sentiel A. , Early Greg A. , Matassa Keith A. , Pabst D. Ann , McLellan William A. 
Published: February 2005

AbstractBackgound: Seal reproductive systems are surrounded by thermogenic muscle and insulating blubber, suggesting elevated temperatures at the gonads and uterus. In the limbs of terrestrial mammals, cooled blood returning from superficial veins is mixed proximally with warm blood returning from deep veins. Thus, mixed cool‐superficial and warmdeep venous blood from the hind limbs is returned to the central circulation.Methods: We describe structures observed in salvaged carcasses of harbor (Phoca vitulina), gray (Haliochoerus gryphus), harp (Phoca groendlandica), hooded (Cystophora cristata), and ringed (Phoca hispida) seals. Vessels were identified by dissection of injected and uninjected material.Results: In contrast to terrestrial mammals, phocid seals have anastomoses between the veins of the distal hind limb and the pelvis which allow large volumes of cool blood returning from the skin surface of the flipper to enter the gluteal, pelvic, or pudendo‐epigastric veins. This provides a cool‐superficial venous return that remains separate from the warm‐deep venous return of the femoral veins. The cooled venous blood from the hind flippers supplies venous plexuses lining the inguinal region and the abdominal and pelvic cavities.Conclusions: Cooled blood may prevent hyperthermic insult to seal reproductive systems. © 1995 Wiley‐Liss, Inc.
Tissue differentiation and correlated changes in enzymatic activities during primary antler development in fallow deer (Dama dama)
Authors: Szuwart Thomas , Kierdorf Horst , Kierdorf Uwe , Althoff Jörg , Clemen Günter 
Published: February 2005

AbstractBackground: Deer antlers are useful models for studying bone growth and biomineralization in mammals. To achieve a better understanding of the mechanisms underlying the formation of primary cranial appendages in deer, the present study relates the histogenesis of primary antlers to changes in enzymatic (phosphatase) activities in the different tissue zones of this organ.Methods: The growing tips of the primary antlers (4.3 to 5 cm in length) were removed from five fallow bucks, aged about 10 months. Part of the material was processed for light microscopy. The other part was cryofixed, and the different histologically defined regions were analyzed for the activities of alkaline phosphatase (ALP) and tartrate‐resistant acid phosphatase (TRAP) as well as for the concentrations of inorganic and organic phosphate.Results and Conclusions: Histologically, the primary antler could in distoproximal direction be divided into eight different zones (dermis; perichondrium; zones of cartilage formation, hypertrophy, mineralization, and degeneration; primary spongiosa; secondary spongiosa). The histological results demonstrate that the elongation of the primary antler proceeded through a modified form of endochondral ossification, resembling that seen during formation of pedicles and secondary antlers. The concentrations of the extractable activities of ALP and TRAP progressively increased from the perichondrium to the zone of cartilage mineralization. Thus, highest activity of TRAP during primary antler formation occurred at an earlier stage of tissue differentiation than in somatic endochondral ossification, where the enzyme is a biochemical marker of osteoclastic activity during bone remodeling. The present results might reflect the presence of osteoclastic precursor cells in the zone of cartilage mineralization as an adaptation to the rapidity of antler growth. Our findings of the contents of extractable ALP, inorganic and organic phosphate in the different tissue zones of the developing primary antler are in good agreement with previous studies analyzing epiphyseal growth plates and point to the fact that ALP causes a rise in inorganic phosphate and the removal of inhibitors for mineralization, like pyrophosphate. © 1995 Wiley‐Liss, Inc.
Cellular distribution patterns of lanthanum and morphometry of rat hearts exposed to different degrees of ischemic stress
Authors: Schmiedl A. , Bach F. , Fehrenbach H. , Schnabel Ph. A. , Richter J. 
Published: February 2005

AbstractBackground: The element lanthanum (La) can be used as a tracer for verification of membrane permeability. The aim of this study was to establish whether (1) distribution of La in the myocardium of rat hearts depends on the degree of ischemic stress and (2) morphometrically determined cell and mitochondrial swelling correlates with the La distribution.Materials and Methods: Isolated beating rat hearts were arrested by coronary perfusion with the cardioplegic solution Custodiol® (controls) or by aortic cross clamping followed by exposur to different degrees of ischemic stress. The solutions for perfusion‐and postfixation as well as for rinsing contained 1.1% La(NO3)3. Cellular and mitochondrial swelling were determined morphometrically and myocytes exhibiting intracellular La were quantified and stated as percentage of test fields.Results: Immediately after cardiac arrest La was present as precipitates only in a few myocytes adjacent to the outer mitochondrial membrane as seen by cTEM and ESI. In such cells La was also detected by EELS in mitochondrial matrix and myofibrils. Advanced ischemic stress led to an increase of the percentage of myocytes containing detectable intracellular La. After 45 min ischemia at 30°C, myocytes and mitochondria showed a remarkable edema and different intracellular distribution patterns of La. After 90 min of ischemia at 20°C interruptions of sarcolemma could only be detected in a few of the swollen myocytes. Roundish La granules were seen in the myofibrils. The percentage of myocytes containing intracellular La and the extent of cellular and mitochondrial swelling showed a significant correlation.Conclusions: Patterns of intracellular La distribution depend on the degree of ischemic stress and correspond to the degree of cellular as well as mitochondrial edema. These results point at a direct relation between alterations of membrane permeability and development of edema. © 1995 Wiley‐Liss, Inc.
Ultrastructure and cytochemical staining characteristics of canine natural killer cells
Authors: Knapp Deborah W. , Turek John J. , Denicola Dennis B. , Chan Thomas C. K. , Carter Wayne O. , Snyder Paul W. , Robinson J. Paul 
Published: February 2005

AbstractBackground: The purpose of this work was to describe the ultrastructure and cytochemical staining characteristics of canine peripheral blood lymphocytes with natural killer (NK) cell activity, with comparison made to non‐NK lymphocytes.Methods: Canine lymphocyte populations evaluated for ultrastructure, cytochemical staining, and NK function (by 51 chromium release assay) included: peripheral blood lymphocytes; lymphocytes from band 1 (NK‐enriched), band 2, and the pellet of a 45/50% percoll gradient; lymphocytes from the supernatant fluid (non‐conjugated lymphocytes) and pellet (lymphocytes conjugated to tumor cell targets) of a 17% percoll gradient; and null (CD4−CD8−) and CD4−CD8+ lymphocytes.Results: NK activity was concentrated in band 1 lymphocytes of the 45/50% percoll gradient with further enhancement of activity occurring in sorted null cells. Canine NK cells were 5.5 to 6.5 μm in diameter with a reniform (kidney bean shape) nucleus, and electron‐dense cytoplasmic granules. NK cells (percoll band 1 cells and null cells) had larger cell and nuclear area, and less round nuclei when compared to non‐NK lymphocytes. The overall cytochemical staining (chloracetate esterase, peroxidase, sudan black B, naphthyl acetate esterase, naphthyl butyrate esterase periodic acid‐Schiff stain, and acid phosphatase with and without tartrate) pattern was similar in all the lymphocyte populations evaluated.Conclusions: This work confirms the usefulness of a 45/50% percoll gradient in obtaining a NK‐enriched fraction of canine lymphocytes, and shows further enhancement of NK activity in sorted CD4−CD8− cells. The ultrastructure of canine NK cells is similar to that reported for human NK cells, but is different from that of other canine peripheral blood lymphocytes. Standard cytochemical staining does not discriminate canine NK cells from other lymphocytes. © 1995 Wiley‐Liss, Inc.
Fibrous architecture of the dorsal aponeurosis of the thumb
Authors: Bade Holger , Krolak Christoph , Koebke Jürgen 
Published: February 2005

AbstractBackground: The extensor apparatus of the thumb displays obvious structural variations in its proximo‐distal expanse. Its associated tissue comes in close relation to the dorsal aponeurosis that have varying topographical relationships to the extensor apparatus of the thumb. This region is especially important as the location of pathological and repair processes.Methods: In this anatomical study using a modified embedding technique a histological description of the fibrous architecture of the dorsal aponeurosis and the peritendinous connective tissue body of the thumb is presented.Results: The dorsal connective tissue of the thumb forms different layers of collagen lamellae as a peritendinous system around the tendons of the long and short extensor tendons of the thumb. This peritendinous laminar system as the main part of the dorsal aponeurosis is connected with both the capsular and the retinacular ligaments of the thumb.Conclusions: It will be shown that the structural variations of the dorsal aponeurosis and peritendinous connective tissue are an expression of different topographical zones of stress along the lines of a balanced musculofibrous stabilization of the interphalangeal joint of the thumb. The expansions in the peritendinous intercellular space act as defined gliding spaces or clefts of the extensor apparatus. © 1995 Wiley‐Liss, Inc.
Physiological response of central metabolism inEscherichia colito deletion of pyruvate oxidase and introduction of heterologous pyruvate carboxylase
Authors: Vemuri G.N. , Minning T.A. , Altman E. , Eiteman M.A. 
Published: February 2005

AbstractWe studied the physiological response ofEscherichia colicentral metabolism to the expression of heterologous pyruvate carboxylase (PYC) in the presence and absence of pyruvate oxidase (POX). These studies were complemented with expression analysis of central and intermediary metabolic genes and conventional in vitro enzyme assays to evaluate glucose metabolism at steady‐state growth conditions (chemostats). The absence of POX activity reduced nongrowth‐related energy metabolism (maintenance coefficient) and increased the maximum specific rate of oxygen consumption. The presence of PYC activity (i.e., with POX activity) increased the biomass yield coefficient and reduced the maximum specific oxygen consumption rate compared to the wildtype. The presence of PYC in apoxBmutant resulted in a 42% lower maintenance coefficient and a 42% greater biomass yield compared to the wildtype. ProvidingE. coliwith PYC or removing POX increased the threshold specific growth rate at which acetate accumulation began, with an 80% reduction in acetate accumulation observed at a specific growth rate of 0.4 h−1in thepoxB‐pyc+strain. Gene expression analysis suggests utilization of energetically less favorable glucose metabolism via glucokinase and the Entner‐Doudoroff pathway in the absence of functional POX, while the upregulation of the phosphotransferase glucose uptake system and several amino acid biosynthetic pathways occurs in the presence of PYC. The physiological and expression changes resulting from these genetic perturbations demonstrate the importance of the pyruvate node in respiration and its impact on acetate overflow during aerobic growth. © 2005 Wiley Periodicals, Inc.
Electrical response and function of a bitter substance receptor associated with the maxillary sensilla of the larva of the silkworm, Bombyx mori L.
Authors: Ishikawa Shigeo 
Published: February 2005

AbstractThis receptor was strongly stimulated by “bitter” substances such as strychnine nitrate, salicin, brucine, nicotine, etc. as well as by the aqueous extracts which were obtained from many normally unacceptable plant leaves for the larvae. Such bitter substances for human sense as phenylthiourea, betaine, and MgSO4 were inert.This maxillary hair associates a water receptor (W) and two salt receptors (N2 and N2′) as well as the R receptor.When a solution contained both bitter substance and NaCl, the respective substance had a synergistic effect on N2 + N2′ or R receptor activities in a certain concentration range of each compound. Responsiveness of the R or N2 + N2′ receptors seemed to depend on the the mixing ratio of the two compounds. CaCl2 had inhibitory effects on the activity of the R and W receptors, but not on those of the N2 and N2′ receptors. Sugars had no effect on R receptor activity.The inhibitory effect on the feeding was observed when the substance stimulating the R receptor was present in either filter paper or fresh leaves. The inhibitory effect was considerably lessened by inactivation of the R receptor neuron.Accordingly, it is supposed that the exclusion of botanical species from the food plant range of the silkworm larvae might be determined in some parts by a high frequency of occurrence of the specific stimuli for the R receptor in their leaves.
Sialic Acid of Mammalian Cell Lines
Authors: Kraemer Paul M. 
Published: February 2005

AbstractApproximately two‐thirds of the total sialic acid (S.A.) per cell of a number of cell lines (L‐929, L5178Y, HeLa, C13, P183, and CHO) was located at the cell surface but was inaccessible to the action of trypsin, pronase, lysozyme, β‐glucuronidase, or hyaluronidase. The mean surface density of S.A. ranged from 5.4 × 105 molecules/μ2 surface area for the L5178Y cell to 16.1 × 105 molecules/μ2 for the P183 cell. The P183 cell line, which is a polyoma virus‐transformed derivative of Stoker's C13 line, consistently contained more S.A. per cell than the latter under a variety of growth conditions, although the two lines did not differ in mean cell volume. When mean cell volume of C13, P183, or CHO cells was experimentally manipulated by thymidine or colcemide blockade, S.A. content per cell followed size changes closely. No evidence could be found for a shift in total S.A. per unit cell volume accompanying the period of maximum mitotic activity of partially synchronized CHO suspension cultures. Comparisons between cells grown on glass and the same cells grown in suspension, or between cells grown to different densities on glass, indicated no differences in the characteristic S.A. content per cell.
Binding of cations by microsomes from rabbit skeletal muscle
Authors: Carvalho Arselio P. 
Published: February 2005

AbstractFragmented sarcoplasmic reticulum and transverse tubular system, as isolated in the microsomal fraction from rabbit skeletal muscle, bind H+, Na+, K+, Ca++, Mg++, and Zn++. The binding depends on a cation exchange type of interaction between these cations and the chemical components of the membranous systems of the muscle cell. The monovalent and divalent cations exchange quantitatively for each other at the binding sites on an equivalent basis. Scatchard plots of the H+ binding data indicate that the binding groups can be resolved into two major components in terms of their pK values. Component 1 has a pK value of 6.6 and a capacity for H+ binding of 2.2 meq/g N. The second component has a much higher H+ binding capacity (7–8 meq/g N), but its pK value, 3.4, is non‐physiological. The binding of cations other than H+ at a neutral pH occurs at the binding sites making up component 1. The order of affinity of the cations for the microsome binding sites is H+ » Zn++ > Ca++ > Mg++ » Na+ = K+ as reflected by the apparent respective pKM values: 6.6, 5.2, 4.7, 4.2, 1.3, 1.3. Caffeine, which causes contracture and potentiates the twitch of skeletal muscle, does not interfere with the binding of Ca++ by the microsomes at neutral pH.
The release of amino acids from nerve during stimulation
Authors: Wheeler Darrell D. , Boyarsky L. L. , Brooks W. H. 
Published: February 2005

AbstractFrog sciatic nerves were incubated for 24 hours in either glycine, aspartic acid, glutamic acid, lysine, leucine, γ‐aminobutyric acid, glutamine, or pentanedioic acid (all labeled with C14), and the rates of release of these compounds were monitored under resting conditions and during stimulation. Upon stimulation, the rate or release of glutamic acid increased an average of 200% above the resting rate. This extra release is highly specific with regard to molecular size and structure, since of the compounds tested only glutamic acid gave significant increases in rates of release during stimulation. Ouabain (0.1 mM) had no effect on the rate of release; however, sodium azide (0.2 mM or 1.0 mM) completely eliminated the extra release during excitation, indicating that the increased permeability to glutamic acid is energy‐dependent. Competition experiments show that the extra release of glutamic acid can be eliminated with 10 mM concentrations of non‐isotopic choline. The hypothesis is advanced that glutamic acid is actively extruded by a highly specific carrier mechanism.