bluuebunny/crossref_metadata_2025 huggingface dataset:
Loss of Microvilli Caused by Glycerol Treatment of Uterine Epithelial Cells
Authors: Murphy C.R. , Swift J.G. , Mukherjee T.M. , Rogers A.W.
Published: July 2008

We have used freeze-fracture electron microscopy to examine the effects of glycerol treatment of unfixed cells of a compact tissue – the uterine luminal epithelial cell. These cells respond in a similar fashion to other cells, i.e., the intramembranous particles (IMPs) become clustered. In addition we show that glycerol reduces the number of microvilli on these cells and we discuss two mechanisms that may contribute to both clustering of IMPs and loss of microvilli.
Die Arteria falcea anterior des Erwachsenen
Authors: Müller F.
Published: July 2008

The anterior falcate artery (arteria falcea anterior) represents the continuation of the anterior ethmoidal artery. In the adult, it has been described previously only in its rostral portion, which supplies the falx cerebri. In the present study, however, it is shown that there exists a continuation which runs in the parietal dura of the superior sagittal sinus and which unites with the frontal branch of the middle meningeal artery at the border between the frontal and parietal bones. In addition, the anterior falcate artery, by means of arterioarterial connections, is associated with the nearby branches of the frontal ramus that supply the frontal dura. The anterior falcate artery, mostly paired, is furnished with cross-connections. Venae comitantes are absent from the parallel-running main branches. In occlusion of the ophthalmic artery, the anterior falcate artery, due to its connections with the middle meningeal artery, may be significant in the establishment of a collateral circulation to the orbit.
Innervation of the carotid body
Authors: Vázquez-Nin Gerardo H. , Costero Isaac , Echeverría Olga M. , Aguilar Roberto , Barroso-Moguel Rosario
Published: July 2008

The innervation of the carotid body in the cat was studied by means of light- and electron-microscopic techniques. Sinus nerve resection, glossopharyngeal resection, bilateral cervical sympathectomy, excisions of two nerves, and injection of 6-hydroxydopamine (6-OH-DA) were performed in different groups of animals. It was found that resection of the sinus nerve produces a rapid phase of degeneration of intralobular fibers and synaptic boutons, followed by a reinnervation with a progressive reappearance of these elements. This reinnervation is retarded by sympathectomy and prevented by 6-OH-DA. It is therefore concluded that reinnervation is due to collateral regeneration of nearby sympathetic fibers. Resection of the sinus nerve produces an increase in the number of argentaffin cells and dense-cored vesicles in the cytoplasm of principal cells. These findings suggest the existence of efferent synaptic contacts between this nerve and principal cells. Part of the intralobular fibers and synaptic boutons degenerate after bilateral sympathectomy demonstrating that sympathetic axons connect synaptically to the principal cells. Sympathetic fibers reach the carotid body, not only from branches of the cervical plexuses but also from fibers running in the adventitia of the common carotid artery, and via glossopharyngeal and sinus nerves. The vagus nerve contributes a few fibers to the parenchymal lobules of the carotid body.
Neuro-histochemical study of the Adrenal gland of Rattus rattus rufescens (Indian black rat) as revealed by cholinesterase technique
Authors: Purwar R.S.
Published: July 2008

The present investigation was undertaken to study the innervation and acetyl-cholinesterase (AChE) distribution in the adrenal gland of Rattus rattus rufescens (Indian black rat) by cholinesterase technique. The percentage of myelinated nerves in the cortical zone (cortex) and medulla zone was high. AChE-positive and multipolar ganglia on the outer medulla region, and the ganglia and nerve cells, arranged in chain-like fashion in the chromafnn tissue, were recorded. AChE activity was marked in the cortical zone (in the form of spots) and in the medulla zone (in the form of white and black grains).
Characterization of glycogen in selected tissues of turkey poults with spontaneous round heart disease and furazolidone-induced cardiomyopathy
Authors: Czarnecki Caroline M. , Jegers Angelika , Jankus Edward F.
Published: July 2008

Furazolidone (FZ) at 700 ppm was added to feed mixtures fed turkey poults 2–5 weeks after hatching to induce acute experimental cardiomyopathy. Poults in the control pen received the same ration but without FZ. From EKG data obtained at weekly intervals, poults were selected for sacrifice at 5 and 10 weeks of age. Poults were sacrificed by cervical dislocation and appropriate samples of tissue from the left ventricle, liver, pectoralis and tibialis cranialis muscles were removed for glycogen assays. Character of glycogen, as determined by percent of branching and number of glucose units per segment, was not significantly altered in poults with spontaneous round heart disease or FZ-induced cardiomyopathy. This suggests that the glycogen accumulation noted in these conditions most closely resembles type II glycogenosis.
Proprioceptive innervation of the external cremaster muscle of some domestic mammals
Authors: Palmieri Giovanni , Panu Rino , Asole Anna , Branca Andrea
Published: July 2008

The proprioceptive innervation of the external cremaster muscle of some domestic animals was studied. Muscle spindles and tendon organs with their well-known features were found, but this finding was uncommon and unexpected in the investigated animals. For this reason, we believe that there is no relationship between the presence of these proprioceptors and the cremasteric reflex.
Hode und Eierstock im didaktischen histologisch-terminologischen Vergleich
Authors: Preuβ F.
Published: July 2008

The so-called sex glands are not glands but germ hives. The germ cells are surrounded by nurse cells which alone build the tubulus or follicle epithelium (spermio- and oonutricytes). In the testis there is being differentiated between intra- and extratubular blood-germ cell barriers. The sperm cells should ultimately be called spermiocytes, the egg cells no longer be confused with the egg. The 4 germ cell generations and their 4 developmental phases in both organs are compared point by point. The interstitial cells are named andro- and gynocytes for considered reasons. The search for suitable names promotes knowledge and teaching.
Electron microscopy of lymphatics of the porta hepatis
Authors: Schatzki Peter F.
Published: July 2008

The ultrastructure of the lymphatics of the porta hepatitis at the junction with the liver parenchyma has.been examined. The lymphatics are composed of endothelium composed of flattened cells containing occasional mitochondria, pinocytotic vesicles and nuclei. The cells are bound by maculae adherentes, zonulae occludentes and desmosome-like structures. There are occasional fibers between endothelium and underlying collagen. Occasional pores closed by diaphragms are present. There is very little basement membrane. There is no definite communication with the spaces of Mall and Disse, but the lymphatic lumens are separated from these areas only by the junctional processes, which may be permeable. Lymphatics are present only in collagenized portal areas and not in the liver parenchyma proper.
Ein neues Konservierungs- und Aufbewahrungssystem für anatomisches Material
Authors: Platzer Werner , Putz Reinhard , Poisel Sepp
Published: July 2008

The authors introduce a new system of preservation and storage of anatomical material. The system accomplishes the following demands: (1) avoidance of fungi on section material, (2) alternative application of various preservation fluids, (3) utmost flexibility of storage capacity, (4) clearness and easy control, (5) elimination of unpleasant smell, (6) smallest possible need of staff and (7) low working expenses.
Histotopik von Glykosidasen in den akzessorischen Geschlechtsdrüsen des Ebers vor und nach Kastration
Authors: Sinowatz F. , Skolek-Winnisch R. , Lipp W. , Meierhofer B.
Published: July 2008

The histochemical distribution of six glycosidases (N-acetyl-β-glucosaminidase, β-galactosidase, β-glucuronidase, α-galactosidase, α-mannosidase and α-fucosidase) was investigated in the prostate, glandula vesicularis and glandula bulbourethralis of castrated and non-castrated adult boars. The functions of the glycosidases in the male accessory sex glands of the boar and their androgen dependence are discussed briefly.
Histochemical studies on the peroxidase localization in the rat ovary and uterus during various reproductive stages
Authors: Agrawal Prabha , Laloraya Manmohan M.
Published: July 2008

A histochemical study has been made of peroxidase changes in rat ovary and uterus during different developmental stages of the normal and pregnant rats. The peroxidase was found to be present in the corpus luteum of the ovary of both normal and pregnant rats as well as in the allantochorionic placenta, while the growing follicles in the immature and mature rat ovary showed no activity. The possible physiological significance of the peroxidase changes in relation to luteal steroidogenesis has been discussed.
Arterial segmentation in the goat (Capra hircus) spleen
Authors: Gupta S.C. , Gupta C.D. , Gupta S.B.
Published: July 2008

50 corrosion casts of the splenic artery and its tree were studied to observe the arterial segmentation in the goat spleen on the basis of the intrasplenic distribution. The following observations were made: (i) 74% showed the presence of two arterial segments, a right and a left one; (ii) 10% revealed three arterial segments, a hilar, a right and a left one, and (iii) 16% showed the absence of arterial segmentation in the goat spleen.
Vascularization of the conducting system in the human heart
Authors: Hadžiselimović H.
Published: July 2008

On 200 randomized specimens of the human heart, of either sex, from 20 to 80 years of age, we investigated the vascularization of the conducting system of the heart in relation to the type of coronary ramification, by the dissection, injection-corrosive, radiographic and coronarographic method. The symmetrical type of arterial vascularization was established in 24%, the right type in 63% and the left type in 13% of the cases investigated. The sinoatrial node is vas-cularized in 60% by the right and in 40% of the cases by the left coronary artery. The atrio-ventricular node and the stem of the atrioventricular bundle are vascularized by the right coronary artery in 85% of the cases investigated, in 13% by the left and in 2% by both arteries. The right fasciculus of the atrioventricular bundle is vascularized by the left artery, the left fasciculus by both arteries. The vascularization of the posterior strand in both ventricles is conformable to the type of arterial vascularization of the heart.
Functional implications of felid forelimb anatomy
Authors: Gonyea W.J.
Published: July 2008

The elbow and wrist anatomy of 17 felid species were studied and compared with that of other representative mammalian carnivores. Based on the shape and position of the olecranon fossa, it was determined that for felids the forelimb cannot travel in a ‘pendulumlike’ motion during locomotion, but must travel through an arch away from the parasagittal plane of the body. For the anterior limb, the degree of deviation from the parasagittal plane was correlated with habitat preference. In this regard, those felids that are exclusive forest dwellers (found exclusively in high, densely structured habitats) had the greatest angle of inclination of the olecranon fossa. In addition, these species had a large lateral olecranon tuberosity for the attachment of the lateral head of the triceps muscle. For those felids that inhabit more open terrain (low-structured habitat), the olecranon fossa was less inclined, the medial olecranon tuberosity relatively large, and the medial head of the triceps was significantly heavier than those of the forest felids. Both the wrist and elbow joints exhibited a large degree of mobility which was reflective of the claw-equipped forelimb being used as a hunting weapon.
Electron-microscopic study of the maturing rat red nucleus
Authors: Povlishock John T. , Taylor John J. , Seibel Hugo R.
Published: July 2008

The maturing large neurons of the rat red nucleus in animals ranging in age from 1 to 21 days of postnatal life were studied ultrastructurally. Days 1–6 were characterized by rapid morphologic maturation occurring concomitantly with the onset of synaptogenesis. Morphogenesis was confined to the soma, while the first synaptic contacts were also formed in relationship to the soma. Days 6–9 demonstrated continued somal morphogenesis exemplified by cytoplasmic expansion and by the conspicuous presence of perisomatic and growth cone processes. Proximal dendritic morphogenesis was initiated, and synaptogenesis became complex with synaptic sites occurring in relation to the neuronal soma, the perisomatic processes and proximal dendrites. Days 9–15 were characterized by the completion of somal and proximal dendritic morphogenesis and by a massive degree of synaptogenic activity. During this interval, the soma lost perisomatic and growth cone processes, while somatic spines appeared. By the end of this period the neuronal soma and the proximal dendrites appeared mature in terms of both morphology and synaptic input. Complete neuronal maturation was ultimately attained by day 21 of postnatal life.
Etude radio-anatomique des artères interosseuses
Authors: Valdecasas Huelin José Maria Garcia , Barreiro Francisco Javier Jorge , Barcia Encarnación Campelo
Published: July 2008

A study of the interosseus arteries has been done on 100 forearms, using anatomical and anatomical-radiological methods. Of the points studied, the following are of particular interest: the mode of origin of the trunk of the interosseus arteries, the systematization of the various types of divisions and the vascular territories of the anterior and posterior branches.
Ipsi- and contralateral anastomosis of the uterine arteries
Authors: Lindenbaum Ella , Brandes Joseph M. , Itskovitz Joseph
Published: July 2008

In vitro perfusion technique and plastic cast injection methods were utilized to study the ipsi- and contralateral anastomosis of the human uterine arteries. The perfusion method repeatedly illustrated the abundant contralateral communications around the cervical region of the uterus. Superficial contralateral anastomosis within the peritoneal coverings was observed in the fundic region of the uterus. Any other myometrial midline crossing of vessels was not reproducible probably due to the specific distortion caused by the leiomyomas of these operatively excised specimens. The plastic cast technique succeeded in mapping out the three-dimensional arterial tree of the uterus. With simultaneous injection into the right and left uterine arteries, and using differently colored plastic on each side, the two-color plastic junction points appeared in the midsagittal plane, and the interarterial anastomosis was clearly visible throughout the entire length of the uterus. This technique exhibited many arterioles traversing into the contralateral side. Furthermore, an extremely dense capillary network with contralateral anastomosis was apparent and distributed according to the multiple-layer organization of the myometrium. Postmenopausal uteri elicited a paramedial arteriole zigzagging across the midline of the posterior wall of the uterus. This type of arteriole was not observed in this study in any of the uteri of females of childbearing age.
Innervation of the rabbit cornea
Authors: Tervo Timo , Palkama Arto
Published: July 2008

The innervation of the rabbit cornea was investigated histochemically and electron-microscopically with.special reference to the autonomic nerves. Both formaldehyde- and glyoxylic-acid-induced fluorescence methods revealed adrenergic nerves in the stroma; a few fibres were also observed between the basal epithelial cells near the limbus. Acetylcholinesterase-(AChE-)positive nerves were found both in the stroma and in the epithelium, whereas nonspecific cholinesterase (NsChE) activity appeared only in the stromal nerves. Under the electron microscope, both AChE and NsChE activities were observed to be located in the axon membranes. A weak NsChE reaction also appeared in the Schwann cells. When the specimens fixed with KMn04 were examined under the electron microscope, most nerve fibres did not contain any special axoplasmic structures, although several axons contained mitochondria. Moreover, two vesicle-containing axon types were found in the stromal nerves; axons with small granular vesicles and axons containing small agranular vesicles. In the epithelium, two types of fibres were observed; one type contained only mitochondria while the other showed both agranular vesicles and mitochondria.
Gestalt und Befestigung der Bandsysteme im Sinus und Canalis tarsi des Menschen
Authors: Schmidt Hans-Martin
Published: July 2008

In addition to loose connective tissue, fat and blood vessels, the sinus and canalis tarsi also contain the .capsules for the intertarsal joints as well as several varyingly stable tracts of fibers which present themselves in varying planes and directions but are nevertheless in a discernible arrangement to one another. This arrangement of fibers was studied on the feet of 40 adults whereby five distinct and clearly definable bundles could be regularly dissected. Starting from the lateral side and going medially, these groups of fibers can be divided into a pars lateralis, pars intermedia and pars medialis of the retinaculum mm. extensorum inferius, also a lig.talo-calcaneum obliquum and a lig. canalis tarsi. Microscopically, fibrocartilage is evidenced in the ligaments and retinacula near their points of attachment to the bone. The ligaments lying lateral to the axis of movements for the talocalcaneal joint restrain the inversion while the medially lying lig. canalis tarsi prevents the eversion.
Micromorphology of the placenta of rats reared on marginal vitamin-A-deficient diet
Authors: Noback Charles R. , Takahashi Yoko I.
Published: July 2008

This study describes some effects of marginal vitamin A deficiency on the light-microscopic morphology of the placentas of rats. The placentas obtained were from rat dams reared on a basal vitamin-A-deficient diet supplemented with retinyl ester and other dams reared on the same basal diet supplemented with retinoic acid. These supplements are forms of vitamin A. The placentas at the 14th and 17th days of gestation were examined histologically. All placentas were associated with viable, apparently healthy fetuses and showed no signs of necrosis. Placentas at these ages were selected because a marked decrease in the number of viable fetuses occurs following the 14th day in the dams maintained on the retinoic-acid-supplemented diet. The placentas from these two groups were essentially similar in their histological appearance. However, differences were noted in the general proportions and topographic relations of the cells (trophospongial and glycogen cells) in the central region of the junctional zone and the inner tro-phoblast cells of the labyrinthine zone. These differences are probably related to the rate of cellular differentiation and the facilitation of the metaplastic changes of the (1) parenchymal cells to glycogen cells of the junctional zone and (2) inner trophoblast cells of the labyrinthine zone. This is consistent with the known role of vitamin A in the development and differentiation of epithelial cells. The change in the rate in the differentiation of the inner trophoblast cells is probably a crucial event and can account for the inability of the placenta of many marginal vitamin-A-deficient rat dams to carry fetuses to term.
Histocytology of the avian (Gallus domesticus) carotid body
Authors: Dreyer Maria V. , De Boom H.P.A. , De Wet P.D. , Hugo N. , Eloff F.
Published: July 2008

The histotopography of the silvery-white glistening carotid body and the branchial derivates in the cranial thoracic inlets as well as the histocytology of the particular organ were revealed by various microtechniques. Three types of randomly distributed epithelioid cells, many capillaries, and small and large sinuses are observable. Myelinated fibres are sparsely distributed. 25 clinically healthy white leghorn males were used for this investigation.
Microbodies of the pig liver
Authors: Singh Amreek , Williamson Wendy , Geissinger Dieter , Bhatnagar M.K.
Published: July 2008

The ultrastructure of hepatic microbodies of pigs was studied in liver samples fixed in phosphate-buffered 2% glutaraldehyde (pH 7.4) and postfixed in 2% osmium tetroxide. The microbodies were rounded or ovoid in shape and contained a granular matrix enclosed with a single limiting membrane. The matrix, in many of the organelles, contained an amorphous or an organized (crystalloid) area. The crystalloids were organized as fine, alternating electron-opaque and electron-lucent lines, or as groups of tubules arranged in more than one plane. Profiles of smooth endoplasmic reticulum were usually found near the microbodies. 34 micro-bodies were approximately 0.67 ± 0.02 μm (mean ± standard error) in length and were approximately 0.56 μm (± 0.02 μm) wide. The marginal plates consisted of strata which exhibited a periodicity. The average length and width of 17 plates was approximately 0.34 ± 0.03 μm and 0.002 μm, respectively. This study clearly establishes the occurrence of marginal plates in micro-bodies of porcine liver.
The influence of fetal circulation on liver cell ultrastructure
Authors: Rømert P. , Matthiessen M.E.
Published: July 2008

This study shows that autolytic changes in liver tissue from mini-pig fetuses are less extensive if, after removal of the uterus, the fetal circulation is left anatomically intact until excision and fixation. It must be concluded that, if it is not possible to remove and fix fetal material immediately, the fetus should be kept in the intact amniotic cavity with an intact umbilical cord.
Comparative histochemical study of the enzyme changes in the ovary and uterus of mammals with special references to steroidogenesis
Authors: Agrawal P. , Laloraya M.M.
Published: July 2008

A comparative study of the enzymes Δ5-3β-HSD, cytochrome oxidase and peroxidase has been made in the ovaries and uterus of mammals (mouse, guinea pig, cat and dog) during various reproductive phases. The granulosa cells of developing follicles, hypertrophied interstitial cells of thecal origin and the luteal cells show intense Δ5-3β-HSD and cytochrome oxidase activity. Peroxidases are found to be present in the corpus luteum and the epithelial cords of thecal origin. Δ5-3β-HSDand cytochrome oxidase activity is localized to the endometrium and myometrium of mature and pregnant uterus of mouse and guinea pig, while peroxidase is seen only in the decidua and endometrial glands of pregnant animals. The significance of these enzymes is discussed in relation to the cellular basis of luteinization and steroid hormone synthesis.
Number, diameter and distribution of the rat optic nerve fibers
Authors: De Juan J. , Iñiguez C. , Carreres J.
Published: July 2008

Light- and electron-microscopic methods for nerve fiber counting and diameter measuring are described. These methods were applied to the rat optic nerve. Differences between light- and electron-microscopic results are shown. Coincidences and divergences with the current literature data are discussed.
Effects of ovariectomy and estradiol injection on nuclear structures of endometrial epithelial cells
Authors: Vázquez-Nin Gerardo H. , Echeverría Olga M. , Molina Elisa , Fragoso José
Published: July 2008

The changes of the rate of RNA synthesis produced by castration and estradiol injection on the surface endometrial cells of the rat are profited to study the variations in the number and size of nuclear ribonucleoprotein structures and in the disposition of chromatin. Two-dimensional measurements on sections contrasted with preferential procedures were employed to estimate the fraction of nuclear volume occupied by each element. Young adult rats in estrus are used as controls. 3 weeks after ovariectomy, the area fraction occupied by the nucleolus is reduced almost to a third of the control value, while the number of perichromatin granules per unit area of nucleus has significantly increased. A single injection of 20 μg of estradiol produces a rapid decrease of the number of perichromatin granules to a fourth of the value of castrate animals, in 15–30 min, followed by a slow increase. Nucleolar area fraction begins to increase 2 h after estrogen administration and at 24 h it is higher than in controls. It is concluded that the changes of the nucleolar volume are due to the effects of estradiol on the synthesis of nucleolar RNA, while the variations of perichromatin granules are produced by the combination of the effect on extranucleolar RNA synthesis and on its processing and/or transporting to the cytoplasm. Both effects are independent and undergo different temporal courses.
The presence of alkaline phosphatase in the coronal suture of rat
Authors: Markens I.S. , Oudhof H.A.J.
Published: July 2008

The purpose of the present study was to determine the presence of alkaline phosphatase within the coronal suture, the dura mater and the pericranium. The histologic sections reveal that no alkaline phosphatase activity could be observed within the coronal suture as well as the dura mater, while the pericranium did contain this enzyme. These findings are brought in relation with the occurrence of synostoses, which can be induced under experimental conditions.
Development of the external muscle coats in the digestive tract of the opossum, Didelphis virginiana
Authors: Cutts J.H. , Krause W.J. , Leeson C.R.
Published: July 2008

Development of the external musculature of the gastrointestinal tract has been studied in the stomach, small intestine and colon of the postnatal opossum. The muscle support is thin and poorly developed at birth, especially in the stomach and small intestine where only the inner layer is completely formed. The outer layer is discontinuous and formed by scattered myoblasts. The muscularis externa of the colon at birth is considerably thicker and both layers are present. Subsequent development of the muscularis externa consists of an early period of proliferative activity followed by hypertrophy. A low rate of mitotic activity continues throughout development and into the adult. Elements of the myenteric plexus are present at birth.
The exocrine pancreas in triamcinolone-treated mice
Authors: Finkelbrand Sara , Coleman Raymond , Silbermann Michael
Published: July 2008

6-week-old ICR strain female mice were given between 16 and 21 daily injections of “the synthetic glucocorticoid, triamcinolone diacetate (8 mg/kg body weight). Portions of their pancreas were examined by light and electron microscopy and compared with untreated littermate controls. Despite marked variability from animal to animal and lobule to lobule, triamcinolone treatment induced increased zymogen depletion and also the development of large basal vacuoles in many acinar cells. At the ultrastructural level, acinar cells show pronounced mitochondrial swelling, which in many instances is accompanied by the development of myelin whorls. The number of cells with distended granular endoplasmic reticulum is increased as is the number of atrophying cells and cells apparently undergoing disintegration. In addition, there are indications of marked activation of interlobular perivascular macrophages which show marked vacuolation. Our observations suggest that pancreatic acinar cells show cytological changes as a result of experimental hypercorticoidism.
Correlations between tooth dimensions of man and apes
Authors: Lavelle C.L.B.
Published: July 2008

Computation of simple, multiple and canonical correlation coefficents between the mesiodistal and buccolingual crown diameters showed a high degree of association between the overall crown dimensions of man and chimpanzee. Information regarding the partitioning of genetic and environmental influences on crown form must therefore await further data regarding the degree of correlation between detailed intra-crown dimensions. Nevertheless, the data from this study suggested that dentitions should be regarded as whole biological entities rather than a series of discrete teeth.
Ultrastructural data and chronobiological patterns of the synaptic ribbons in the outer plexiform layer in the retina of albino rats
Authors: Spadaro A. , De Simone I. , Puzzolo D.
Published: July 2008

Synaptic ribbons of the outer plexiform layer in the retina of albino rats are examined, with particular regard to their ultrastructure and to their chronobiological behaviour. As to the ultrastructure, aside from the typical lamellar and granular morphology, synaptic ribbons, whose central bar is roundish and granular, delaminate or furnished with enlarged extremities, are shown. As to the chronobiological pattern, synaptic ribbons undergo to circadian changes in their absolute number, being particularly numerous during the light phase, and few during darkness. It is also considered the morphology (ratio between granular and lamellar) and the size (long, intermediate and short) during the 24-hour cycle; in both cases, diphasic curves are observed. On the basis of these results, in the junction photoreceptors-bipolar cells, synaptic ribbons are polymorphic, dynamic structures, whose number and morphology strictly depend on environmental light conditions.
Positional relationships of structures attached to long bones during growth
Authors: Grant Philip G. , Buschang Peter H. , Drolet Don W.
Published: July 2008

The various soft structures attached to bones maintain relatively constant relationships during growth. The exact nature of these relationships has, however, never been studied. As part of our ongoing research into the factors controlling muscle migration, we have determined these relationships for some structures. We studied the positions of 37 muscles from 24 New Zealand white rabbits ranging in age from birth to maturity. The muscles were selected to illustrate different kinds of attachments: fleshy and tendonous, restricted and extensive, and at both ends of a bone. The proximal and distal edges of attachments were carefully exposed and measured in a device that allowed us to measure the position relative to the ends of the bones without parallax distortion. We used the data to compute correlation coefficients and regression equations for position vs. length of bone. Results show that the correlation coefficient was above 0.9 for most cases and was significant at the 0.5 level for all but 4 cases. Slopes of the regression equations varied considerably, but in all cases they indicated that the closer to the end of a bone, the greater the distance migrated. The significance of these results is discussed.
Atypical thyroid follicles arising from an ultimobranchial-like cyst in a postnatal canine thyroid gland
Authors: Booth K.K. , Ghoshal N.G.
Published: July 2008

While investigating the intrinsic vasculature of the canine thyroid gland, atypical thyroid follicles were observed histologically, arising from a postnatal thyroid cyst of unknown origin, in stained sections of a male, 1-year-old, mesaticephalic dog. The animal was anesthetized, bled, killed by injection of Toxital directly into the heart, and perfused with 10% buffered neutral formalin solution. The thyroid tissue was fixed, embedded in paraffin, sectioned serially, and mounted on glass slides. Concordant with descriptions in the literature, this structure appeared to be a postnatal ultimobranchial-like cyst with direct connections to both ultimobranchial and mixed follicles. Seemingly, this observation has never been reported previously in the canine and would lend support to the hypothesis that ultimobranchial-like cysts may give rise to these atypical follicles. However, the authors are not totally convinced that all such thyroid cysts are solely ultimobranchial in origin. A review of the literature supporting this contention is discussed.
Association of mitochondria with the plasma membrane of the acinar cells of the mouse submaxillary glands
Authors: Sharawy M. , Schuster G. , Pashley D. , Palmer P.
Published: July 2008

Electron micrographs of resting and pilocarpine-stimulated acinar cells of mouse submaxillary glands revealed the majority of mitochondria in close association with lateral and basal portions of the acinar cell membranes. The qualitative observations were confirmed by quantitation. Speculations as to the functional significance of this observation are discussed.
Ultrastructural Aspects of the Antimesometral Implantation in the Rabbit
Authors: Segalen J. , Chambon Y.
Published: July 2008

A scanning and transmission electron microscope study of blastocysts immediately prior to ovo implantation and of antimesometrial implantation sites was conducted. External membranes of the eggs showed at 6 days post coitum the imprint of the endometrial surface, pointing to the early establishment of contact between egg and uterus. At 7 days the antimesometrial region showed flattening with continued evidence of gland openings that appear to be the elective sites of attraction of the trophoblastic knobs. Attachment of the trophoblastic knobs followed on days 8 and 9.
Genetic Factors Influencing Neurosensitivity to Early Phenobarbital Administration in Mice
Authors: Yanai Joseph , Bergman Arieh , Feigenbaum Jeffrey J.
Published: July 2008

This study was designed to assess the possible genetic determinants of neurosensitivity to early (neonatal) phenobarbital (PhB) administration and to conduct a strain comparison for the cerebellar histology of both inbred and outbred mice. HS/Ibg, C57BL/10 and DBA/1 pups were injected with 50 mg PhB/kg daily on neonatal days 2–21. On day 50, treated animals (B) of all strains had smaller brains than controls (C). Moreover, the cerebellar area was decreased in HS and C57 B mice but not in DBA mice, suggesting genotype-environment interaction. B mice from all strains had similar Purkinje cell losses. Strain comparison showed that control C57 mice had smaller brains than control HS, and DBA had smaller brains than both HS and C57. Similarly, C57 had smaller cerebellar layers than HS and DBA had smaller cerebellar layers than both HS and C57. DBA and C57 mice had fewer Purkinje cells than HS but did not differ from each other.
Some Ultrastructural Features of the Muscular Coat of Human Small Intestine
Authors: Faussone Pellegrini Maria Simonetta , Cortesini C.
Published: July 2008

The muscular coat of human small intestine is constituted by a ‘special’ layer, by the main component of the circular layer, by the region between the circular and the longitudinal layers and by the longitudinal layer. The ‘special’ layer is made up of the innermost 4–6 rows of muscle cells of the circular layer and is separated from the main component of the circular layer by a space in which an abundant connective tissue and numerous nerve fibers rich in nerve endings are located. Cells identified as interstitial cells of Cajal are located inside the ‘special’ layer, the space between it and the main component of the circular layer and in the region between the circular and the longitudinal layers. In this region small bundles of obliquely orientated muscle cells, apparently bridging the circular to the longitudinal layer, are found.
Genetic and Sex Influences on the Regional Distribution of Acetylcholinesterase Activity in the Porcine Brain and Hypophyses under Humid Tropical Climatic Conditions
Authors: Egbunike Gabriel N.
Published: July 2008

The adaptability of one indigenous and four exotic breeds of pigs to the humid tropical climatic conditions of Ibadan was comparatively evaluated with acetylcholinesterase activity (AChE) of brain and hypophyseal parts as the parameter. Significant breed differences were observed in the weight and AChE of the hypophyses and in the AChE of the brain parts. With regard to sex, only the relative adenohypophyseal weight and the AChE of the cerebellum and medulla oblongata were influenced. The results demonstrate the greater adaptability of the indigenous pigs to their native environment than the exotic breeds. A reduced sensitivity to the various stressing factors of the indigenous pigs and the females was implied. Results also suggest that the Large White breed may be more suited to the conditions prevalent in Ibadan than the other exotic breeds.
Numerical Size Variability in the Peripheral Nerve
Authors: Tomasch Joseph
Published: July 2008

Cross-sections of 17 sciatic nerves were examined by an image analyzer as to sum of fibre carrying cross-sectional areas and by light-microscopic visual area sampling as to myelinated and unmyelinated fibre densities. Intra-perineural cross-sectional areas range from 3.5 ×106 to 7.6 ×106 µm2 with a mean of 5.8 ×106 in the 12 male subjects and 3.4 ×106 to 4.0 ×106, x = 3.7 ×106 µm2 in 4 mature females. Estimates of total fibre content range from 6.1 × 104 to 1.6 × 105 in the males and 6.1 × 104 to 9.2 × 104 in these female subjects. Variations in axon number totals and in ratios of myelinated to unmyelinated fibre densities are not age correlated. Variations also occur in the diameter distributions of myelinated fibres and in ratios of small to large diameter myelinated fibres.
Intrinsic Innervation of the Oesophagus in Dogs with Special Reference to the Presence of Muscle Spindles
Authors: Asaad K. , Abd-El Rahman Sawsan , Nawar Nabil N.Y. , Mikhail Y.
Published: July 2008

The study of the intrinsic innervation of the oesophagus in dogs revealed the presence of capsulated ganglia and scattered neurons in the upper and lower thirds of the organ. The cells were either oval or pyriform with multiple dendrites and ill-defined capsules of pericellular satellites. Furthermore, muscle spindles were detected amidst the obliquely set muscle fibres of the oesophageal muscular coat. Simple motor and plates supplied the striated extrafusal muscle fibres. The submucous nerve plexus contained no ganglia. Its nerve fibres extended to form periacinar and intra-acinar axons to the oesophageal submucous glands. Subjacent to the mucosa, the subepithehal nerve plexus gave intraepithelial free terminals that penetrated the basement membrane to end within the stratified epithelium just beneath its cornified layer.
Présence de microcils sur l’extrémité apicale des cils de l’épithélium de la trompe uteriné
Authors: Foroglou-Kerameos Ch. , Manthos A. , Bontis I. , Katsaros I.
Published: July 2008

The role played by the ciliated cells of the salpinx in the transport of the ovum has been the subject of numerous studies. In this work we examined the ultrastructure of the cilia of the ampullary portion of the oviductal epithelium in a series of mammals and in man. We found the classical structure of the motile cilia. The free part of the cilia, surrounded by the cell membrane, is composed by nine peripheral doublets and by a pair of central microtubules. In the species we examined, we had the occasion to observe an ultrastructural particularity of the cilia. It is about a group of microcilia placed on their apical extremity. These formations were observed in longitudinal sections and appeared aligned on the top of the cilium. They have a length of 200–300 Å and a diameter of 100 Å. Their number varies with the species examined. The proportion of cilia which presented microcilia is also different from species to species. The functional role of the microcilia is unknown.
Observations on the Structure and Innervation of the Presumptive Carotid Sinus Area in the Giraffe (Giraffa camelopardalis)
Authors: Kirumbi Kimani James , Maina Mungai Joseph
Published: July 2008

The tunica media of the giraffe carotid artery is characterised by a predominantly muscular structure, except for a small area at the origins of the occipital and the vestigal internal carotid arteries. The latter has a preponderantly elastic structure and corresponds in extent to the parts of the carotid arterial wall innervated by a branch of the glossopharyngeal nerve. Sensory nerve terminals, characterised by an abundance of mitochondria, are found in the deeper parts of the adventitia bordering the elastic zone. It is concluded that the elastic zone at the cranial portion of the carotid arterial system in the giraffe constitutes the equivalent of a carotid sinus. It is further suggested that the preponderance of elastic tissue in this area is a morphological adaptation of the arterial wall to a baroreceptor function. Pertinent to this suggestion is the demonstration of a close structural relationship between the sensory nerve endings and the elastic fibres.
Polarizing Microscopy of Birefringent Lipids in Rabbit Fetal Lungs
Authors: Hung Kuen-Shan , Menon C.D. , Hung Shirley H.
Published: July 2008

The development of birefringent lipids in pre- and postnatal rabbit lungs was studied by polarizing microscopy (PM) and correlated with transmission electron microscopy (TEM). Birefringent lipids first appeared as small scattered particles in the developing alveolar walls at 27 days of gestation. These particles became aggregated, gradually increased in amount in older fetuses, and reached a prenatal maximum at 30 days. Numerous particles were located in the alveolar lumen, beginning in the 30-day fetuses. Further increase in the amount of birefringent lipids occurred in the 60-day-old rabbits. TEM demonstrated cytoplasmic lipid inclusion bodies in the type II pneumocytes at 25 days of gestation. Some of these inclusions were lamellated, but regular lamellated bodies were often seen in older fetuses. It appears that the development of birefringent lipids is closely correlated with the development of lamellated bodies seen with TEM, and PM is a simple, useful method in following the development and maturation of surfactant lipids. The phospholipid component of the pulmonary surfactant is secreted by the type II pneumocytes, and the development of these cells and the surfactant system has been studied in many animal species by various methods. To identify the intra- and extracellular structures related to surfactant secretion, light microscopy [Chiswick et al., 1973], transmission (TEM) and scanning electron microscopy [Kikkawa et al., 1968; Wang et al., 1973], the freeze-fracture technique [Smith et al., 1972; Williams, 1978; Kikkawa and Manabe, 1978], and immunocytochemistry [Ten Have-Opbroek, 1979; Ratal et al., 1979] have been used. The surfactant lipids were associated with lamellated bodies with regular, repeating patterns, and therfore they were detectable
Quantitative Studies on the Ultrastructural Differentiation and Growth of Mammalian Cardiac Muscle Cells
Authors: Gotoh Tadashi
Published: July 2008

Ultrastructural differentiation of cardiac muscle cells in the bilateral atria and ventricles of the cat at 1, 16, 25 and 40 days and 6 months after birth was studied by morphometry on electron micrographs. At the newborn stage, no T-tubule was found in the ventricular muscle cells, but specific granules were already noted in the atrial myocytes. The cell diameter of the ventricular myocardium was greater than that of the atrium at this stage. The T-tubule was first recognized in the ventricular muscle cells at day 16, at which stage the area occupied by the mitochondria and glycogen in the atrial muscle cells was definitely found to differ from that in the ventricular muscle cells. Thereafter, the differences in the ultrastructure between the atria and ventricles became more remarkable, particularly in the cell diameter and in the mitochondrial area. The cat cardiac muscle cells are characterized by numerous lipid droplets within the cytoplasm in contrast to those of the rat and the guinea pig.
Distribution of Osteonic and Interstitial Components in the Human Femoral Shaft with Reference to Structure, Calcification and Mechanical Properties
Authors: Portigliatti Barbos M. , Bianco P. , Ascenzi A.
Published: July 2008

This paper analyzes the distribution of osteons and interstitial bone in the femoral compacta according to their structure, degree of calcification and mechanical properties. Three cross sections, 100 μm thick, each located 1 cm from the next, were prepared by grinding from the middle third of a human femoral shaft. Starting from the premise that, in lamellar bone, lamellae whose fiber bundles and crystallites have a longitudinal course withstand loading by tension, whereas those whose fiber bundles and crystallites have a transversal course withstand loading by compression, each osteon and fragment of interstitial bone has been given a number recording the percentage of its surface consisting of lamellae with transversally oriented fiber bundles and crystallites (bright under the polarizing microscope). The degree of calcification of the same structures was determined micro-radiographically. The distribution of both osteons and interstitial bone was assessed using a tungsten grid for reference. The total surface of each bone microstructure, and the percentage of that surface consisting of bright lamellae, were all calculated using a Zeiss Video-plan. Our results confirm the view that the distribution of both osteons and interstitial bone is mainly related to their structure – and hence to their mechanical properties. In addition, bone remodeling seems to be most active in areas capable of supporting tensile stress.
A Longitudinal and Comparative Study of Some Structural and Hormonal Alterations in the Endocrine Pancreas of Spontaneously Diabetic and Streptozotocin-Induced Diabetic Mice
Authors: Stearns Susan B. , Benzo Camillo A.
Published: July 2008

A comparative study of the endocrine pancreas was carried out in genetically diabetic (db) mice and in mice with streptozotocin-induced (Sz) diabetes over a 12-week period of pronounced diabetes. Mice were examined at 9, 12 and 21 weeks of age. Plasma and pancreatic levels of immunoreactive insulin and immunoreactive glucagon were measured in both experimental animal models, and the biochemical data obtained were correlated with ultrastructural observations on the endocrine pancreas. Both pancreatic and plasma immunoreactive insulin levels were severely depressed in all Sz mice. Although pancreatic immunoreactive insulin concentrations in db mice were consistently lower than control values, these animals displayed a hyperinsulinemia which gradually dropped to control levels by 21 weeks. Pancreatic immunoreactive glucagon levels in 12- and 21-week-old db mice were markedly lower than those found in either control or in Sz mice. However, both db and Sz mice in all age groups exhibited a marked and persistent hyperglucagonemia. Pancreatic islet tissue was examined concurrently in control and experimental animals. The ultrastructural changes occurring in the endocrine cells are reported and discussed with regard to the pancreatic and plasma levels of the hormones presently monitored and in light of other recent studies on these animal models.
Site of Cellular Uncoupling in Injured Cardiac Tissue in the Dog
Authors: Núñez-Durán Harol , Peón Jorge , Bárcenas Laura , Ubaldo Ernestina
Published: July 2008

We injured false tendons of the dog heart and examined the intercalated disks (ID) to locate the site of cardiac cell uncoupling. We put the preparations at two calcium concentrations: Ca++-free solution (no healing) and [Ca++]=5.4 mM (‘healing-over’). They were studied immediately, and 1 h, after the injury. We examined the diffusion of Procion yellow from the cut end and measured the relative area of nexus. After the ‘healing-over’ we found that the ID linking damaged and undamaged cells were the barrier to the diffusion of the dye, and that these ID underwent an exponential decrease in the nexal area (time constant 1.5 h). On the other hand, the next ID (i.e. the other extremity of the same cells) kept the nexal area they had in the unhealed condition. These facts indicate that the true uncoupling site is the ID that separate damaged from undamaged cells.