bluuebunny/crossref_metadata_2025 huggingface dataset:
Endotoxemia causes central downregulation of sympathetic vasomotor tone in healthy humans
Authors: Sayk Friedhelm , Vietheer Alexander , Schaaf Bernhard , Wellhoener Peter , Weitz Gunther , Lehnert Hendrik , Dodt Christoph
Published: July 2008

Experimental endotoxemia as a model of the initial septic response affects the autonomic nervous system with profound cardiovascular sequelae. Whether the postsynaptic sympathoneural activity to the muscle vascular bed is altered in the early septic phase remains to be determined. The present study aimed to elucidate the early effects of LPS on muscle sympathetic nerve activity (MSNA) and cardiovascular regulation in healthy humans. Young, healthy volunteers randomly received either an LPS bolus (4 ng/kg body wt, n = 11) or placebo (saline; n = 7). Experimental baroreflex assessment (baseline measurements followed by infusion of vasoactive drugs nitroprusside/phenylephrine) was done prior to and 90 min following LPS or placebo challenge. MSNA, heart rate, blood pressure, and blood levels of catecholamines, TNF-α and IL-6 were measured sequentially. Endotoxin but not placebo-induced flu-like symptoms and elevated cytokine levels. In contrast to placebo, LPS significantly suppressed MSNA burst frequency 90 min after injection [mean ± SE: 12.1 ± 2.9 vs. 27.5 ± 3.3 burst/min (post- vs. pre-LPS); P < 0.005] but increased heart rate [78.4 ± 3.1 vs. 60.6 ± 2.0 beats/min (post- vs. pre-LPS); P < 0.001]. Baseline blood pressure was not altered, but baroreflex testing demonstrated a blunted MSNA response and uncoupling of heart rate modulation to blood pressure changes in the endotoxin group. We conclude that endotoxin challenge in healthy humans has rapid suppressive effects on postsynaptic sympathetic nerve activity to the muscle vascular bed and alters baroreflex function which may contribute to the untoward cardiovascular effects of sepsis.
Effect of vaginal distention on elastic fiber synthesis and matrix degradation in the vaginal wall: potential role in the pathogenesis of pelvic organ prolapse
Authors: Rahn D. D. , Acevedo J. F. , Word R. A.
Published: July 2008

Matrix metalloprotease (MMP) activity is increased in the postpartum vagina of wild-type (WT) animals. This degradative activity is also accompanied by a burst in elastic fiber synthesis and assembly. The mechanisms that precipitate these changes are unclear. The goals of this study were to determine how vaginal distention (such as in parturition) affects elastic fiber homeostasis in the vaginal wall and the potential significance of these changes in the pathogenesis of pelvic organ prolapse. Vaginal distention with a balloon simulating parturition resulted in increased MMP-2 and MMP-9 activity in the vaginal wall of nonpregnant and pregnant animals. This was accompanied by visible fragmented and disrupted elastic fibers in the vaginal wall. In nonpregnant animals, the abundant amounts of tropoelastin and fibulin-5 in the vagina were not increased further by distention. In contrast, in pregnant animals, the suppressed levels of both proteins were increased 3-fold after vaginal distention. Distention performed in fibulin-5-deficient ( Fbln5−/−) mice with defective elastic fiber synthesis and assembly induced accelerated pelvic organ prolapse, which never recovered. We conclude that, in pregnant mice, vaginal distention results in increased protease activity in the vaginal wall but also increased synthesis of proteins important for elastic fiber assembly. Distention may thereby contribute to the burst of elastic fiber synthesis in the postpartum vagina. The finding that distention results in accelerated pelvic organ prolapse in Fbln5−/−animals, but not in WT, indicates that elastic fiber synthesis is crucial for recovery of the vaginal wall from distention-induced increases in vaginal protease activity.
Modulation of bladder myofibroblast activity: implications for bladder function
Authors: Sui Gui-Ping , Wu Changhao , Roosen Alexander , Ikeda Youko , Kanai Anthony J. , Fry Christopher H.
Published: July 2008

Bladder suburothelial myofibroblasts may modulate both sensory responses from the bladder wall and spontaneous activity. This study aimed to characterize further these cells in their response to exogenous agents implicated in mediating the above activity. Detrusor strips, with or without mucosa, and isolated suburothelial myofibroblasts were prepared from guinea pig bladders. Isometric tension, intracellular Ca2+, and membrane current were recorded. Cell pairs were formed by pushing two cells together. Tension, intracellular Ca2+, and membrane potential were also recorded from bladder sheets using normal or spinal cord-transected (SCT) rats. Spontaneous contractions were greater in detrusor strips with an intact mucosa and were augmented by 10 μM UTP. ATP, UTP, or reduced extracellular pH elicited Ca2+transients and inward currents ( Erev−30 mV) in isolated cells. Capsaicin (5–30 μM) reduced membrane current (37 ± 12% of control) with minor effects on Ca2+transients: sodium nitroprusside reduced membrane currents (40 ± 21% of control). Cell pair formation, without an increase in cell capacitance, augmented ATP and pH responses (180 ± 58% of control) and reduced the threshold to ATP and acidosis. Glivec (20–50 μM) reversibly blocked the augmentation and also reduced spontaneous activity in bladder sheets from SCT, but not normal, rats. Glivec also disrupted the spread of Ca2+waves in SCT sheets, generating patterns similar to normal bladders. Suburothelial myofibroblasts respond to exogenous agents implicated in modulating bladder sensory responses; responses augmented by physical intercellular contact. The action of glivec and its selective suppression of spontaneous activity in SCT rats identifies a possible pathway to attenuate bladder overactivity.
Modulation of bladder function by prostaglandin EP3 receptors in the central nervous system
Authors: Su Xin , Leon Lisa A. , Wu Charlene W. , Morrow Dwight M. , Jaworski Jon-Paul , Hieble J. Paul , Lashinger Erin S. R. , Jin Jian , Edwards Richard M. , Laping Nicholas J.
Published: July 2008

Prostaglandin EP3 receptors in the central nervous system (CNS) may exert an excitatory effect on urinary bladder function via modulation of bladder afferent pathways. We have studied this action, using two EP3 antagonists, (2 E)-3-{1-[(2,4-dichlorophenyl)methyl]-5-fluoro-3-methyl-1 H-indol-7-yl}- N-[(4,5-dichloro-2-thienyl)sulfonyl]-2-propenamide (DG041) and (2 E)- N-{[5-bromo-2-(methyloxy)phenyl] sulfonyl}-3-[2-(2-naphthalenylmethyl)phenyl]-2-propenamide (CM9). DG041 and CM9 were proven to be selective EP3 antagonists with radioligand binding and functional fluorescent imaging plate reader (FLIPR) assays. Their effects on volume-induced rhythmic bladder contraction and the visceromotor reflex (VMR) response to urinary bladder distension (UBD) were evaluated in female rats after intrathecal or intracerebroventricular administration. Both DG041 and CM9 showed a high affinity for EP3 receptors at subnanomolar concentrations without significant selectivity for any splice variants. At the human EP3C receptor, both inhibited calcium influx produced by the nonselective agonist PGE2. After intrathecal or intracerebroventricular administration both CM9 and DG041 dose-dependently reduced the frequency, but not the amplitude, of the bladder rhythmic contraction. With intrathecal administration DG041 and CM9 produced a long-lasting and robust inhibition on the VMR response to UBD, whereas with intracerebroventricular injection both compounds elicited only a transient reduction of the VMR response to bladder distension. These data support the concept that EP3 receptors are involved in bladder micturition at supraspinal and spinal centers and in bladder nociception at the spinal cord. A centrally acting EP3 receptor antagonist may be useful in the control of detrusor overactivity and/or pain associated with bladder disorders.
Leg intravenous pressure during head-up tilt
Authors: Groothuis Jan T. , Poelkens Fleur , Wouters Constantijn W. , Kooijman Miriam , Hopman Maria T. E.
Published: July 2008

Leg vascular resistance is calculated as the arterial-venous pressure gradient divided by blood flow. During orthostatic challenges it is assumed that the hydrostatic pressure contributes equally to leg arterial, as well as to leg venous pressure. Because of venous valves, one may question whether, during orthostatic challenges, a continuous hydrostatic column is formed and if leg venous pressure is equal to the hydrostatic pressure. The purpose of this study was, therefore, to measure intravenous pressure in the great saphenous vein of 12 healthy individuals during 30° and 70° head-up tilt and compare this with the calculated hydrostatic pressure. The height difference between the heart and the right medial malleolus level represented the hydrostatic column. The results demonstrate that there were no differences between the measured intravenous pressure and the calculated hydrostatic pressure during 30° (47.2 ± 1.0 and 46.9 ± 1.5 mmHg, respectively) and 70° head-up tilt (83.9 ± 0.9 and 85.1 ± 1.2 mmHg, respectively). Steady-state levels of intravenous pressure were reached after 95 ± 12 s during 30° and 161 ± 15 s during 70° head-up tilt. In conclusion, the measured leg venous pressure is similar to the calculated hydrostatic pressure during orthostatic challenges. Therefore, the assumption that hydrostatic pressure contributes equally to leg arterial as well as to leg venous pressure during orthostatic challenges can be made.
Comparing the performance of three generations of ActiGraph accelerometers
Authors: Rothney Megan P. , Apker Gregory A. , Song Yanna , Chen Kong Y.
Published: July 2008

ActiGraph accelerometers are a useful tool for objective assessment of physical activity in clinical and epidemiological studies. Several generations of ActiGraph are being used; however, little work has been done to verify that measurements are consistent across generations. This study employed mechanical oscillations to characterize the dynamic response and intermonitor variability of three generations of ActiGraph monitors, from the oldest 7164 ( n = 13), 71256 ( n = 12), to the newest GT1M ( n = 12). The response due to independent radius (22.1–60.4 mm) and frequency (25–250 rpm) changes were measured, as well as intermonitor variability within each generation. The 7164 and 71256 have similar relationships between activity counts and radius ( P = 0.229) but were significantly different from the GT1M ( P < 0.001). The frequency responses were nonlinear in all three generations. Although the response curve shapes were similar, the differences between generations at various frequencies were significant ( P < 0.017), especially in the extremes of the measurement range. Intermonitor variability was markedly reduced in the GT1M compared with the 7164 and 71256. Other measurement differences between generations include decreased peak counts and decreased sensitivity in low-frequency detection in the GT1M. The results of this study revealed an improvement of the intermonitor variability by the GT1M monitor. However, the reduced sensitivity in low-count ranges in the GT1M may not be well suited for monitoring sedentary or light-intensity movements. Furthermore, the algorithms for energy expenditure predictions developed using older 7164 monitors may need to be modified for the GT1M.
Low-Voltage-Activated Potassium Channels Underlie the Regulation of Intrinsic Firing Properties of Rat Vestibular Ganglion Cells
Authors: Iwasaki Shinichi , Chihara Yasuhiro , Komuta Yukari , Ito Ken , Sahara Yoshinori
Published: July 2008

Individual primary vestibular afferents exhibit spontaneous activity the regularity of which can vary from regular to irregular. Different aspects of vestibular responsiveness have been associated with this dimension of regularity of resting discharge. Isolated rat vestibular ganglion cells (VGCs) showed heterogeneous intrinsic firing properties during sustained membrane depolarization: some neurons exhibited a strong adaptation generating just a single or a few spikes (phasic type), whereas other neurons showed moderate adaptation or tonic firing (tonic type). Tonic discharging VGCs were rare at postnatal days 5–7 and increased up to ∼60% of neurons during postnatal 2–3 wk. To explore the major factors responsible for the discharge regularity of primary vestibular afferents, we investigated the contribution of K+channels to the firing properties of isolated rat VGCs. Phasic firing became tonic firing in the presence of 4-aminopyridine or α-dendrotoxin, indicating that Kv1 potassium channels control the firing pattern of the phasic VGCs. Tetraethylammonium decreased the number of spikes during step current stimuli in all types. Blockade of Ca2+-activated K+channels decreased the number of spikes in tonic VGCs. Our results suggest that Kv1 channels are critical both in determining the pattern of spike discharge in rat vestibular ganglion neurons and in their proportional change during maturation.
Serotonin 1B Receptor Modulates Frequency Response Curves and Spectral Integration in the Inferior Colliculus by Reducing GABAergic Inhibition
Authors: Hurley Laura M. , Tracy Jo Anne , Bohorquez Alexander
Published: July 2008

The selectivity of sensory neurons for stimuli is often shaped by a balance between excitatory and inhibitory inputs, making this balance an effective target for regulation. In the inferior colliculus (IC), an auditory midbrain nucleus, the amplitude and selectivity of frequency response curves are altered by the neuromodulator serotonin, but the changes in excitatory-inhibitory balance that mediate this plasticity are not well understood. Previous findings suggest that the presynaptic 5-HT1B receptor may act to decrease the release of GABA onto IC neurons. Here, in vivo extracellular recording and iontophoresis of the selective 5-HT1B agonist CP93129 were used to characterize inhibition within and surrounding frequency response curves using two-tone protocols to indirectly measure inhibition as a decrease in spikes relative to an excitatory tone alone. The 5-HT1B agonist attenuated such two-tone spike reduction in a varied pattern among neurons, suggesting that the function of 5-HT1B modulation also varies. The hypothesis that the 5-HT1B receptor reduces inhibition was tested by comparing the effects of CP93129 and the GABAAantagonists bicuculline and gabazine in the same neurons. The effects of GABAAantagonists on spike count, tuning bandwidth, two-tone ratio, and temporal response characteristics mimicked those of CP93129 across the neuron population. GABAAantagonists also blocked or reduced the facilitation of evoked responses by CP93129. These results are all consistent with the reduction of GABAA-mediated inhibition by 5-HT1B receptors in the IC, resulting in an increase in the level of evoked responses in some neurons, and a decrease in spectral selectivity in others.
Application of Single and Dual Multilayer Optics for Powder X‐Ray Diffraction
Authors: Misture Scott T.
Published: July 2008

The performance of parallel beam multilayer optics, including a parabolic multilayer Osmic MaxFlux GO‐13N and a flat custom multilayer, was evaluated experimentally and compared to Bragg‐Brentano and traditional
‘‘parallel beam’’ or ‘‘thin film’’ optical geometries. A novel arrangement of a parabolic multilayer in the incident beam with a flat multilayer in the diffracted beam functioning as an analyzer crystal was proven effective for powder diffraction applications. The dual‐optic configuration improves resolution while eliminating sample displacement and transparency errors as expected for a configuration with equatorial divergence below 100 arcseconds. Fundamental parameters fitting showed that the parabolic multilayer can be accurately modeled using a constant Gaussian function, while a long parallel‐plate soller collimator requires a constant hat function. No additional convolutions are necessary for the diffracted‐beam flat multilayer because of the lower acceptance angle.
Improvement of Transmission Loss Using Active Control with Virtual Modal Mass
Authors: Lhuillier V. , Gaudiller L. , Pezerat C. , Chesne S.
Published: July 2008

This paper deals with an alternative modal active control approach to reduce sound transmission through a structure excited by an acoustic wave. Active control makes it possible to conserve lightness while improving acoustic performances. “Modal mass damping control” is proposed for light and small structures having slight modal overlap. The aim of this control is to modify the modal distribution of high radiation efficiency modes with active modal virtual mass and active modal damping. The active virtual mass effects lower eigen frequencies to less audible frequency range while reducing vibration amplitudes in a broad frequency range. An application of this concept is presented in a simple smart structure. It is harmonically excited on large bandwidth by a normal acoustic plane wave. Results obtained by active modal virtual mass and damping control are compared to other modal control approaches.
Effects of Simulated Increases in Body Weight on the Growth of Limb Bones in Hypophysectomized Rats
Authors: Simon Mark R. , Holmes Kenneth R. , Olsen Aart M.
Published: July 2008

The purpose of this study was to subject groups of hypophysectomized male and female rats each to a simulated specific 10% increase in body weight, to a maximum of a doubling of body weight, in order to study the effects of quantified, increased, intermittent, compressive forces on limb bone growth. Chronic centrifugation was employed. 21-day-old Sprague-Dawley rats were used. After 60 days of centrifugation, the rats were sacrificed. The humerus, radius, ulna, femur and tibia were removed from each animal, cleared of all soft tissues, and the bone lengths measured on Helios calipers with an accuracy of 1/20 mm. The data were corrected for differences due to individual body weight by dividing bone lengths by the cube root of the body weight of the same animal. Tukey’s studentized multiple-range test was performed to identify aggregations (sets) of force groups between which there are significant differences. The data suggest that the simulated increases in body weight, within the range used for this study, enhance bone growth in hypophysectomized female and male rats similarly – hypophysectomy being a condition known to inhibit bone growth.
Bone Mineral Content of Limb Bones of Male Weanling Rats Subjected to 30 and 60 Days of Simulated Increases in Body Weight
Authors: Simon Mark R. , Holmes Kenneth R. , Olsen Aart M.
Published: July 2008

The purpose of this study was to subject groups of male rats each to a specific 10% simulated increase in body weight, ranging from 1.1 to 2.0 g. Constant centrifugation was employed. After 30 and 60 days, rats were sacrificed and perfused with 10% BNF. The humerus, radius, ulna, femur, and tibia were removed, cleared of all soft tissues, weighed, decalcified with EDTA, and reweighed. Bone mineral content (BMC) was determined using the formula: [(Wu – Wd) ÷ Wu] × 100. Tukey’s multiple range test was used. The data suggest that male weanling rats subjected to simulated increases in body weight, within the range used in this study, undergo enhanced BMC, a bimodal curve describing the relationship between BMC and simulated increases in body weight.
Comportement morphologique du corpuscule rénal au cours de l’hibernation chez le lérot commun (Eliomys quercinus L.)
Authors: Milla Soria
Published: July 2008

We studied 20 garden dormouses (Eliomys quercinus), 10 of which had hibernated. The renal tissue was fixed in Bouin’s fluid, embedded in paraffin and sectioned at 7 μm; the sections were stained with azocarmin. These preparations were studied with an optical microscope (Leitz SM-Lux). Hibernation causes an increase in the corpuscular, glomerular and Bowman capsular areas. We thought that this statistically significant increase in the size of the corpuscular structures might be due to the glomerular blood stasis and larger flow of plasma ultrafiltrated towards the capsular space, because of an intense vasoconstriction of the efferent arteriole; this vasoconstriction is due to sympathetic stimulation and renin hypersecretion.
Further Studies on the Nature of Neural Intranuclear Inclusions (Roncoroni Bodies)
Authors: Penner Abraham , Tritt Gavin
Published: July 2008

It is generally accepted that chromosomes are not visible in interphase except in certain diptera, amphibia and rare unicellular organisms where they are represented by polytene, giant chromosomes. Such structures are exemplified by cells in which growth is evident by increase in size while the polytene structures increase in size rather than in number. These giant chromosomes are active metabolically, synthesizing mRNA and causing increasing activity in the corresponding cells. Experimental procedures leading to increased activity in neurones were accompanied by the appearance of nuclear inclusions which behaved very much like the polytene chromosomes metabolically and, as a result, an attempt was made to determine whether they had similar chemical behavior. This proved to be demonstrable and so it is concluded that the Roncoroni body represents a metabolically active interphase chromosomal segment and may be used as a sign of such activity.
Physiological Cross-Section of the Human Jaw Muscles
Authors: Weijs W.A. , Hillen B.
Published: July 2008

The cross-sectional areas of the masseter, temporalis, medial pterygoid and lateral pterygoid muscles were determined by means of computer tomography in 16 male subjects with healthy dentitions. The physiological cross-section (PCS) of these muscles was predicted from the previously determined relationship between PCS and scan cross-sections. In our subjects, mean total PCS of the jaw muscles was twice as high as in cadavers with few natural teeth. The average distribution of total PCS over the four muscles was the same in the two groups. There was considerable individual variation. Strong correlations in cross-sectional area were only found between the masseter and medial pterygoid muscles. Variation in PCS of these two muscles determines 80% of the variation in combined cross-sectional area.
The Caudal Heart of Fish: Not a Lymph Heart
Authors: Vogel W.O.P.
Published: July 2008

The caudal heart is traditionally regarded as part of the lymphatic vessel system in fish. Recently, however, a secondary blood vessel system has been demonstrated in this class of vertebrates, while the existence of lymphatics was questioned. In corrosion casts of the secondary system it is shown that the caudal heart functions as a venous pump in the secondary circulation. Contrary to current views fish do not have true lymphatic vessels. Theories on the phylogeny of lymphatics therefore should be revised accordingly.
Effects of Starvation on the Ultrastructure of the Mouse Parathyroid Gland
Authors: Isono Hideo , Shoumura Shizuko , Ishizaki Noriko , Emura Shoichi , Iwasaki Yuji , Yamahira Tomo , Kitamura Yuzo
Published: July 2008

Ultrastructural changes of the parathyroid glands of starved mice were examined. The parathyroid glands of the starved mice showed a decrease in the volume of Golgi complexes and storage granules and an increase in the volume of lipid droplets, and contained more heterogeneously dense bodies and multivesicular bodies compared with that of the control mice. In addition, the volume of mitochondria, cisternae of granular endoplasmic reticulum and secretory granules and the number of prosecretory granules appeared to be decreased compared to those of the control mice. Myelin-like structures were observed in the parathyroid glands of the starved mice. The results of our study provide support for the hypothesis that starvation exerts an inhibitory influence not only on the synthesis but also on release of parathyroid hormone.
Innervation adrénergique des cellules musculaires lisses de la queue de l’épididyme chez la souris
Authors: Nouhouayi Yolande , Négulesco Irina
Published: July 2008

The adrenergic innervation in the smooth muscle of the cauda epididymidis of the mouse was investigated by a fluorescence technique using glyoxylic acid and by electron microscopy. As in other species, this innervation is well developed in the terminal segment of the epididymis. It varies according to muscular type: the small myocytes of the proximal zone of the tail have a visceral contractile innervation, while for the typical muscle of the distal region, the pattern is a multiple-unit one. In the mouse, the nexus are more numerous than in man and in the monkey, and constitute a facilitating factor.
Descent of the Testis in the Fetal Calf
Authors: Hullinger R.L. , Wensing C.J.G.
Published: July 2008

The descent of the testis in the fetal calf is reviewed, and the role in that process of the swelling reaction of the gubernaculum testis is discussed. The testes of 30 Dutch Friesian fetuses were examined by dissection and light microscopy of sections prepared from chemically and frozen-fixed specimens. The gubernaculum remains unattached to the scrotal fasciae until descent is completed. Shortening of the intra-abdominal gubernaculum and displacement of the testis begins at fetal week 11; the swelling reaction of the gubernaculum occurs between weeks 14 and 15. The testis is at the deep inguinal ring by week 15, and by week 20 it is in the scrotal position and the gubernaculum has regressed. It is proposed that the swelling of the gubernaculum dilates the vaginal ring and enlarges the inguinal canal. The clinical importance of these anatomical relationships and changes is discussed.
Sympathetic Pathways Through the Petrosal Nerves in Monkeys
Authors: Wilson J.E.
Published: July 2008

Light and electron microscope observations of tiny nerve branchlets attached to the nerve of the pterygoid canal suggests that the source of sympathetic autonomic fibres in the greater petrosal nerve may not be solely confined to fibres ‘recurrent’ from the deep petrosal nerve, as hitherto believed.
Fibre Number and Sizes of Mouse Soleus Muscle in Early Postnatal Protein Malnutrition
Authors: Ihemelandu E.C.
Published: July 2008

The effect of early postnatal protein malnutrition on the development of soleus muscle was investigated in 26 mice (13 males, 13 females). The control group received a balanced diet containing 18% lactalbumin while the protein-malnourished group received protein deficient diet containing 0.5% lactalbumin. The body weight was determined both at 3 weeks (weaning age) and 12 weeks of age. The soleus muscle weight, total number and sizes of muscle fibres were also determined at 12 weeks of age for each mouse. There was considerable retardation of body weight and soleus muscle weight. The smaller soleus muscle mass of protein-malnourished mice resulted from loss of muscle fibres and hypotrophy of the remaining fibres. Permanent retardation of body weight after recovery from early postnatal protein malnutrition may be as a result of loss of muscle fibres during that period.
An Ultrastructural Study on Muciparous Microcysts of the Human Adenohypophysis
Authors: Cinti Saverio , Sbarbati Andrea , Balercia Giancarlo , Cigolini Massimo
Published: July 2008

The microcysts found in two adenohypophyses removed from patients with nonsecreting adenomas of this gland have been studied. In one case the cysts were completely surrounded by neoplastic tissue, whereas in the second they were located within the normal parenchyma. The cysts were surrounded by a basement membrane, and appeared to contain a finely granular weakly electron-dense substance. Their walls were lined by mostly cubic cells with microvilli, joined by junctional complexes. Intracytoplasmic microlumina could be seen in some of these cells. Cells showing cilia with a 9 + 2 fibrillar pattern and cells with mucosecretory differentiation were also present. Furthermore endocrine cells were also found in the cyst-lining epithelium. The ultrastructural aspects of the cyst cells lead to reject the hypothesis that these are derived from folliculostellate cells. Besides, intermediate aspects between cyst cells and tumor cells were never visible. Therefore it seems likely that a relationship between adenoma and cyst cells does not exist and that cyst cells originate from remnants of Rathke’s pouch with a ciliate or mucosecretory differentiation. The presence of endocrine cells in the cyst-lining epithelium deserves further study, for it seems to indicate that an endocrine differentiation may occur in the adult, too. To our knowledge this is the first ultrastructural study of these structures in adult human pituitary gland.
Arterielle Gefässversorgung der Cauda pancreatis unter besonderer Berücksichtigung der cauda-corporealen Gefässbeziehungen
Authors: Ebner Inge , Anderhuber Friedrich
Published: July 2008

The cauda pancreatis has a characteristic pattern of vascularization. Among the big arterial stems surrounding it, up to 4 arteries, ‘caudal arteries’, nourish the arterial system of the cauda. These stems originate especially in the Arteria gastroepiploica sinistra and in the lower main splenic branch of the Arteria lienalis. The vascular relations between corpus and cauda can be of different kinds. Five basic types of relations can be identified: type I: the cauda is supplied exclusively by caudal arteries; type II: at least one caudal artery anastomoses with the vessels of the corpus; type III: the cauda is supplied both by the caudal arteries and by vessels of the corpus (non-anastomosing); type IV: combined forms of blood supply by caudal arteries and corpus arteries by way of anastomoses and non-anastomosing vessels are found; type V: the cauda is supplied exclusively be vessels stemming from the corpus. In each of these five types, individual vessels supplying the cauda can assume the function of a terminal vessel.
Retrograde Degeneration within the Dorsal Motor Yagal Nucleus following Bilateral Vagotomy in Rabbits
Authors: Szereda-Przestaszewska Malgorzata
Published: July 2008

The effects of unilateral and bilateral intrathoracic vagotomy on the neuronal structure of the dorsal motor nucleus of the vagus were studied in rabbits. Degeneration affected mainly the small neurones which disintegrated and vanished from dorsal motor nucleus relative to the survival time after operation. A substantial proportion of large neurones was lost or degenerated, but some were preserved unchanged. In unilaterally vagotomized rabbits the dorsal motor nucleus of the intact side showed scattered neurones with axonal reaction which stands up for peripheral crossing of the vagi. The degree of retrograde degeneration was largely determined by the survival time. The nucleus ambiguus was bilaterally preserved unchanged.
Ultrastructure of the Epithelial Cells of the Ventral Prostate from the Hopping Mouse Notomys alexis
Authors: Wong Y.C. , Breed W.G. , Chow P.H.
Published: July 2008

The large ventral prostate of the hopping mouse has abundant secretory units whose epithelial cells vary in height and which often have nuclei in the apical region of the cell. TEM observations indicated two epithelial cell types in which some unusual features occurred. Type A cells had granular endoplasmetic reticulum (GER) whose membranes often formed intracytoplasmic confronting cisternae. Type B cells had more fragmented and vesiculated GER with sparse ribosomes and less frequently also intracytoplasmic confronting cisternae. In the latter cells, two types of granules were found, one of which was derived from the Golgi and the other possibly directly from the GER. Type A cells only had one type of granule present. A highly convoluted membrane was also found at the basal region in many of the cells. The significance of these unusual ultrastructural features has yet to be ascertained.
Photic Responses of the Retina at Different Ages: A Comparative Study Using Histochemical and Biochemical Methods
Authors: Yew David T. , Tsang David S.C. , Chan Y.W.
Published: July 2008

The alkaline phosphatase and DNA-RNA activities in the retinas of young and old albino mice were determined histochemically after photic exposure. Different patterns between the two age groups were obtained for the alkaline phosphatase reaction before and after photic exposure. In the young animals, more retinal layers showed increased activity after exposure whereas in the old animals, the converse was true. DNA-RNA reaction also revealed decreased DNA activities in the old animals 30 h after exposure. The results were also correlated with biochemical studies on 2-deoxyglucose, dopamine and leucine uptakes.
Anatomical Pathways from the White to the Red Pulp in the Human Spleen
Authors: Brozman Miroslav
Published: July 2008

In the human spleen we failed to find marginal zone bridging channels which in rats and mice are said to serve as return routes for lymphocytes from the white into the red pulp. In human spleens, using anticartilaginous antisera which distinctly visualized extracellular structures, in some parts we found the periarterial lymphocyte sheath to be closely attached to the red pulp, so that lymphocytes and other material could pass from the white pulp directly into the red pulp and vice versa. The strips of reticular fibres that seemed to bridge the marginal zone between the follicles and the red pulp proved to be components of reticular structures around the arteries, passing from the periarterial lympohcyte sheath into the follicles or from the follicles through the marginal zone into the red pulp.
Mesencephalic Root Fibers of the Trigeminal Nerve in the Cat
Authors: Ryu Keiko , Kawana Etsuro
Published: July 2008

The trigeminal nerve has three motor roots and one sensory root in the cat. One of the motor roots can be divided into two bundles: the larger and the smaller. These motor roots form the common root with the sensory root at the exit from the pons, sometimes being separated partially by the subarachnoidal space between the medial and the ventral part of the common root. The mesencephalic root fibers are observed numerously in all the motor roots. Some degenerated fibers are observed in the sensory root. The transitional zone of the trigeminal nerve root between central and peripheral nervous system is occupied by interlocking processes of the fibrous astrocyte.
Formation of Tight and Gap Junctions in the Inner Enamel Epithelium and Preameloblasts in Human Fetal Tooth Germs
Authors: Sasaki T. , Segawa K. , Takiguchi R. , Higashi S.
Published: July 2008

Human fetal primary tooth germs in the cap stage were fixed with a glutaraldehyde-formaldehyde mixture, and formative processes of tight and gap junctions of the inner enamel epithelium and preameloblasts were examined by means of freeze-fracture replication. Chains of small clusters of particles on the plasma membrane P-face of the inner enamel epithelium and preameloblasts were the initial sign of tight junction formation. After arranging themselves in discontinuous, linear arrays in association with preexisting or forming gap junctions, these particles later began revealing smooth, continuous tight junctional strands on the plasma membrane P-face and corresponding shallow grooves of a similar pattern on the E-face. Although they exhibited evident meshwork structures of various extents at both the proximal and distal ends of cell bodies, they formed no zonulae occludentes. Small assemblies of particles resembling gap junctions were noted at points of cross linkage of tight junctional strands; but large, mature gap junctions no longer continued into the tight junction meshwork structure. Gap junctions first appeared as very small particle clusters on the plasma membrane P-face of the inner enamel epithelium. Later two types of gap junctions were recognized: one consisted of quite densely aggregated particles with occasional particle-free areas, and the other consisted of relatively loosely aggregated particles with particle-free areas and aisles. Gap junction maturation seemed to consist in an increase of particle numbers. Fusion of gap junctions in the forming stage too was recognized. The results of this investigation suggest that, from an early stage in their development, human fetal ameloblasts possess highly differentiated cell-to-cell interrelations.
Scanning Electron Microscopy of Human Submandibular Gland
Authors: Espinal E.G. , Ubios A.M. , Pradier R. , Cabrini R.L.
Published: July 2008

The fracture surface of human submandibular gland analyzed by scanning electron microscopy is studied here. Acini showed spherical granules of 0.7 ± 0.28 µm diameter, their most distinctive feature. Some empty, septate cavities found contiguous to serous acini were considered to be mucous acini. Striated ducts had a circular lumen, with microvilli forming prominences. Blebs, some intact and others ruptured, were interpreted as apocrine secretion. The ‘separating zone’ of the striated cells was distinguishable from the rest of the cell because the structure of the cell was granular whereas the ‘separating zone’ was fibrillar.
A Re-Assessment of the Tricellular Region of Epithelial Cell Tight Junctions in Trachea of Guinea Pig
Authors: Walker D.C. , MacKenzie A. , Hulbert W.C. , Hogg J.C.
Published: July 2008

The tricellular region of epithelial tight junctions was previously dismissed as a possible avenue of permeability. One reason was that the two parallel vertical fibers, which penetrate the depth of the tight junction, were apparently cross-linked. Another reason was that the tricellular region of the tight junction is deeper than the adjacent bicellular regions. In the course of several freeze-fracture studies of epithelial tight junctions we have made observations which led us to re-assess the tricellular region as an avenue of permeability. We believe that information from ectoplasmic fracture faces is less subject to artifacts and, in ectoplasmic fracture faces of tricellular regions, cross-linking of the vertical furrows has not been observed. In guinea pig tracheal epithelium the tricellular junction is only about 1 μm deep. Following exposure to cigarette smoke, lanthanum ion staining has been observed in some tricellular junctions. It seems that earlier reasons for dismissing tricellular regions of the tight junction as permeability sites may be insufficient and that there is some evidence to support a role in permeability.
Neuronal Migration Independent of Glial Guidance: Light and Electron Microscopic Studies in the Cerebellar Cortex of Neonatal Rats
Authors: Zagon Ian S. , McLaughlin Patricia J. , Rogers William E.
Published: July 2008

Migrating cells from the external germinal layer of the newborn rat cerebellum were studied by light and electron microscopy. Each migrating cell possessed a single, broad, leading process oriented perpendicular to the pial surface. These cell processes were sometimes associated with profiles of other granule cells, but were not necessarily associated with the electron-lucent Bergmann fibers present at these early developmental stages. Miograting granule cells could be observed circumventing both blood vessels and the perikarya/processes of other cells present in the developing molecular layer. Thus, during the early stages of cerebellar ontogeny, when the migration pathway through the molecular layer is sparsely populated with cells and processes, the vertical process of a granule cell may seek actively a path of least resistance, utilizing ‘contacts’ with surrounding objects for avoidance, rather than as guideposts imperative for directing migration. Cellular associations observed at this stage of cerebellar development may thus be more fortuitous than requisite.
Correlation between Number of Placental Detachments and Amount of Postpartum Uterine Involution in Mice
Authors: Shimizu Kiyoshi , Takabe Satoshi , Hokano Masami
Published: July 2008

Both the uterine weight and total hydroxyproline content augumented in parallel with the number of placental scars on the day of parturition. In the uterus having any number of placental scars, the time of half loss of the organ weight and the total hydroxyproline content, respectively, was the same. These results suggested the amount of postpartum involution increases as the number of placental detachment becomes high.
A Study of the Development of Thoracic Vertebrae in the Mouse Assisted by Autoradiography
Authors: Dalgleish Arthur E.
Published: July 2008

Evidence is accumulating that the current concept of resegmentation during vertebral formation is no longer valid. In order to shed some light on this controversial issue, in the present investigation the development of the vertebral column was studied in a graded series of mouse embryos by conventionally stained serial sections and methyl thymidine 3H autoradiography. It was found that the vertebral bodies do not originate from the upper and lower halves of sclerotomes but from a continuous central tissue mass surrounding the notochord, the perichordal tube. The caudal sclerotome half gives rise to the neural arch and the transverse processes, whereas the cranial half forms the connective tissue of the interneural arch space. An intrasclerotomic cleft supposed to form the intervertebral cleft was not found to exist, in accordance with previous studies. The inferred intrasclerotomic cleft is merely the interface between the loose tissue of the cranial sclerotome half and the densely packed cells of the caudal half.
The Branches of the Celiac Trunk
Authors: Vandamme J.P.J. , Bonte J.
Published: July 2008

156 abdominal preparations were explored by arteriography, corrosion and dissection. Classification of the celiac trunk becomes easy if one considers the trunk to be composed of three main stems: the splenic, the hepatic and the left gastric artery, other vessels being less important collaterals. Usually, the celiac trunk bifurcates into the splenic and the hepatic artery; the left gastric artery is a mobile vessel whose origin may slide between the aorta, all over the celiac trunk up to a trifurcation. The direction of the celiac trunk is influenced by the topography of the pancreatic neck and by the origin of the hepatic artery: if the celiac trunk is not the origin of the hepatic artery it is not directed to the right but to the left. It is the hepatic artery that pulls the celiac trunk to the right. Variations in the origin of the splenic artery are exceptional. In contrast to adults, the diameter of the hepatic artery in young children is larger than that of the splenic artery.
Intercellular Junctions Between Human Odontoblasts
Authors: Callé Aleth
Published: July 2008

Intercellular junctions in the odontoblastic layer have been studied with a freeze-fracture technique. Children’s tooth germs were fixed, sliced and deminerahzed. Samples of the pulpodentinal border were routinely prepared for freeze-fracture. Three kinds of intercellular junctions were detected between human odontoblast cell bodies: gap junctions, desmosomes and tight junctions. Numerous gap junctions are responsible for intercellular communication at different levels of the cell bodies. Focal tight junctions, parallel to the axis of the cell, and desmosomes are sites of cell-to-cell adhesion between lateral plasma membranes. At the distal end of the cell bodies, junctional complexes consist of zonular tight junctions and gap junctions. These zonular tight junctions, never before described between odontoblasts, contribute to the pseudo-epithelial organization of the odontoblastic layer. They constitute a predentin-pulp barrier, the permeability of which must be studied to establish their role in relation to dentin formation.
Arrangement of Supramandibular and Suprahyoid Motoneurons in the Rat; A Fluorescent Tracer Study
Authors: Rokx J.T.M. , van Willigen J.D.
Published: July 2008

The arrangement of the motoneurons innervating the supramandibular and suprahyoid muscles was studied in Wistar albino rats using two fluorescent tracers: nuclear yellow and true blue. All supramandibular motoneurons were found within the trigeminal motor nucleus; they appeared to be somatotopically arranged. The suprahyoid motoneurons were located in an accessory trigeminal-facial motor complex. No overlap of the motoneuron pools of the supramandibular and suprahyoid muscle group was observed. Only motoneurons ipsilateral to the treated muscles were labeled. It was shown that a one-to-one relationship always exists between motoneuron and muscle.
Reexamination of the Origin and Early Development of the Human Larynx
Authors: Zaw-Tun H.A. , Burdi A.R.
Published: July 2008

The respiratory primordium buds off the primitive foregut and grows caudally, on a lengthening stalk; the cephalic end of the stalk develops into the glottis and infraglottis, and the rest becomes the trachea. Compression by pharyngeal mesoderm cephalic to the respiratory diverticulum obliterates the foregut lumen ventrodorsally as far cranially as the 4th pharyngeal pouches, forming an epithelial lamina with a narrow pharyngoglottic duct along its dorsal border. The mesoderm also raises an epiglottic and two arytenoid swellings in the pharyngeal floor at the level of the 4th pouches; the triangular ‘cecum’, bounded by these swellings, grows caudally along the ventral border of the epithelial lamina to just above the glottis. Beginning at stage 21, the epithelial lamina separates cephalocaudally, bringing the cecal lumen into continuity with the pharyngoglottic duct to form the laryngeal vestibule; when the separation is complete, the vestibule is continuous with the infraglottic cavity. Meanwhile, bilateral pouches arising from the caudal end of the cecum form the ventricles, the lower lips of which become the vocal folds, and the pharyngeal mesoderm surrounding the laryngeal cavity gives rise to the laryngeal cartilages and intrinsic musculature. The cricoid chondrifies bilaterally from a single center in the ventral arch of a precartilaginous template that encircles the infraglottic cavity, and on meeting forms the dorsal lamina. Each arytenoid chondrifies from a single center, and each half of the thyroid cartilage chondrifies from two. Anlagen for the intrinsic muscles appear during stage 17, sites of individual muscles are recognizable by stage 23, and myofibrils are pfesent by the 12th week.
Ultrastructural Peculiarities of the Inner Portion of the Circular Layer of the Colon. II.
Authors: Faussone Pellegrini Maria Simonetta
Published: July 2008

A layer of muscle cells consisting of 1–3 rows is present on the inner part of the circular layer of mouse colon. These muscle cells are thinner, with a denser cytoplasm and more caveolae than those of the main portion of the circular layer. A connective interstice divides the two parts of the circular layer and is occupied by a nerve plexus rich in varicosities. Groups of cells, identified as interstitial cells of Cajal, and a nerve plexus rich in varicosities are located on the border between the innermost circular layer and the tela submucosa. The interstitial cells have many cytological features in common with muscle cells (caveolae, basal lamina, thin filaments, smooth endoplasmic reticulum, glycogen particles) and touch each other and the nerve endings frequently and the muscle cells of the innermost layer rarely.
Myelination in the Chorda Tympani of the Postnatal Rat: A Quantitative Electron Microscope Study
Authors: Ferrell Fay , Tsuetaki Tracy , Chole Richard A.
Published: July 2008

We determined the course of myelination of the chorda tympani in rats aged from 4- to 30-days-old, the interval of the most rapid developmental changes in neurophysiological taste responses and behavioral discrimination among chemical stimuli. The overall number of axons in rats aged from 16- to 30-days-old and in mature 120-day-old animals were the same and averaged 1,500. By 30 days, rats had 80% of the total number of myelinated axons observed in adults, but the average thickness of the myelin sheath per neuron and the proportion of the total cross-sectional area that were only about 60% of adult values. Observed increases in myelination closely parallel decreasing response latencies of single chorda tympani fibers to tongue stimulation with salts.