bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of x‐irradiation on lens regeneration in adult Triturus viridescens
Authors: Donaldson Donald J.
Published: February 2005

Lens regeneration was inhibited in adult Triturus v. with 1500 r of x‐irradiation. Implants of irradiated or unirradiated segments of dorsal iris were then implanted into either irradiated or unirradiated eyes. When irradiated eyes received irradiated implants, only minor degrees of lens regeneration were seen from host and implant. Unirradiated eyes receiving unirradiated implants often formed two normal lenses, one from the host and one from the implant. Irradiated eyes receiving unirradiated implants usually formed one normal regenerate arising from the implant. Unirradiated eyes receiving irradiated implants usually formed only one normal regenerate, originating from the host. The results indicate that inhibition of lens regeneration by x‐irradiation is due to effects solely on the iris, and that unirradiated neural retina, under the experimental conditions used, does not stimulate recovery of the regenerative ability of an irradiated iris. These results are discussed in relation to the question of neural‐tissue‐mediated recovery of regeneration systems from x‐irradiation.
Quantitative studies of the deep petrosal nerve of the mouse with the electron microscope
Authors: Shimozawa Atsumi
Published: February 2005

Quantitative counts of the deep petrosal nerve of the mouse with the electron microscope have shown that, on an average, 3,208 fibers of the total nerve fibers (3,209) are unmyelinated and only one fiber is myelinated. The unmyelinated fibers in the deep petrosal nerves ranged from 0.1 to 1.7 μ in minor diameters, 0.3‐0.4 μ being most frequent (about 30% ), while their major diameters varied from 0.1 to 2.4 μ the majority being 0.4‐0.7 μ (about 60% ).
The development of sexual dimorphism in the bony pelvis of the squirrel monkey
Authors: Gingerich Philip D.
Published: February 2005

Bony pelves of mature squirrel monkeys are sexually dimorphic. They can be sexed confidently using the ratio of pubis length divided by ischium length, together with a measure of the relative width of the superior pubic ramus. Pelves of immature squirrel monkeys are not sexually dimorphic. Pelves of immature monkeys of both sexes resemble pelves of mature males morphologically. Sexual dimorphism in the pelves of squirrel monkeys is the result of female pelves acquiring morphological features at puberty which differentiate them from mature male pelves and from immature pelves of both sexes, and is not the result of male pelves being altered from immature pelves of the female type as reported for mice and rats.
Filamentous and matrix components of skeletal muscle Z‐disks
Authors: Kelly Douglas E. , Cahill Mary Ann
Published: February 2005

The fine structural appearance of Z‐disk lattices in vertebrate skeletal “fast” muscle varies depending upon whether osmium or glutaraldehyde has been employed as the primary fixative. Prior investigators have attributed the differences to change in the extent of actin filament overlap within the Z‐disk and/or to rearrangement of Z‐disk filaments.

Adult frog and young newt “fast” muscle has been studied under various degrees of stretch, with several different aldehyde and osmium fixation procedures, and after plastic section digestion techniques utilizing Pronase or pepsin. Serial cross sections of Z‐disks were correlated with oriented cross and longitudinal sections. Fixation with collidine‐buffered osmium and veronal acetate‐buffered glutaraldehyde seems to provide the greatest and most distinctly contrasting differences. A consistently arranged phase, the filamentous lattice, can be discerned after either fixation. However, a second phase, termed “Z‐disk matrix,” appears variable, perhaps due to extraction during primary osmium fixation procedures. Glutaraldehyde‐fixed frog muscle Z‐disks display a copious matrix, one which is seldom totally depleted by osmium fixation. In young newt muscle Z‐disks, little matrix is present after glutaraldehyde fixation and none of it remains after primary osmium. In Z‐disks fixed by either method, matrix that is retained appears to be deposited in lattice‐like patterns. It is suggested that these matrix patterns, or their loss, are the basis for the varying images of Z‐disks observed under diferent fixation conditions and that the filamentous lattice is relatively stable. The Z‐disk is more rapidly obliterated by Pronase or pepsin digestion than is any other muscle component, including actin (which appears notably unreactive). The rapid digestion effect is limited to the region postulated to include the matrix phase. Models for the structural interrelationship of filamentous and matrix phases are discussed and compared to prior Z‐disk models.
Ultrastructural changes in the ependymal lining of the median eminence following the intraventricular administration of catecholamine
Authors: Schechter Joel , Weiner Richard
Published: February 2005

Changes in the ependymal surfaces of the floor of the third ventricle and lateral recess have been studied in male rats by electron microscopy after the intraventricular administration of epinephrine or dopamine. In control rats the floor of the third ventricle has essentially a smooth contour interrupted only by occasional bleb‐like protrusions or microvilli. In the floor of the lateral recess this surface gradually becomes more irregular due to the appearance of increased surface modifications. A further increase in the number of complexly‐folded microvilli, pinocytotic vacuoles and coated vesicles occurs on the epen‐dymal surface of the roof of the lateral recess and adjacent ependyma. These morphological findings are consistent with the concept that the ependymal cells of the lateral recess may serve as important sites for the absorption of materials from the CSF.

Increased numbers of bleb‐like protrusions were observed on the ependymal surface of the floor of the third ventricle five minutes after the intraventricular administration of either epinephrine or dopamine. The ependymal surface of the roof of the lateral recess also showed bleb‐like protrusions and a complexly‐folded microvillus border. Fifteen minutes after either the epinephrine or dopa‐mine administration all of the ependymal surfaces studied appeared as in control rats. The increase in bleb‐like protrusions noted in the floor of the third ventricle after the injection of epinephrine or dopamine are suggestive of a secretory process rather than a manifestation of an absorptive function in this region.
Endothelial detachment sites in glomerular capillaries of vinblastine‐treated rats
Authors: Tyson Greta E. , Bulger Ruth Ellen
Published: February 2005

In Wistar‐Fürth rats given vinblastine sulfate intravenously, an abnormality of the glomerular capillary wall was observed. Electron micrographs of renal corpuscles of treated animals revealed sites where the glomerular endo‐thelium had separated from the glomerular basement membrane. The resultant subendothelial space contained a flocculent material similar in appearance to the blood plasma present within the capillary lumen. Endothelial detachment sites were observed near the mesangial region, as well as in parts of the capillary loops distant from the mesangium.

Vinblastine treatment also resulted in a disappearance of microtubules from the cytoplasm of endothelial cells and in an appearance of paracrystalline inclusions which were similar in fine structure to those reported in previous studies using Vincaalkaloids. Although these intracytoplasmic paracrystals were common in the glomerular endothelium of treated animals, they were rarely seen at sites of endothelial detachment. The way in which vinblastine treatment elicits endothelial detachment is not known.
Histologic and histochemical evidence concerning the presence of morphologically distinct cellular zones within the rabbit atrioventricular node
Authors: Anderson Robert H.
Published: February 2005

The rabbit atrioventricular nodal region has been studied using a method of tissue preparation allowing direct comparison of adjacent sections processed by histological and histochemical techniques. By this means, specialized cardiac tissue is found to occupy the region defined electrophysiologically as the atrioventricular node. This region is more extensive than that previously defined by light microscopy. Within this region three types of cell are distinguishable; transitional cells, and upper and lower nodal cells. The last are continuous with and identical to the cells of the atrioventricular bundle. The cell types also exhibit differences in their pattern of innervation. The significance of these cellular zones and their associated nerves is discussed with reference to previous electrophysiological findings and the mechanism of nodal delay.
Response of hamster thyroid light cells to plasma calcium
Authors: Biddulph David M. , Maibenco Helen Craig
Published: February 2005

Light cells in the hamster thyroid gland were examined by electron microscopy and histochemical methods in control, hypercalcemic and hypocalcemic animals. Elevation of plasma calcium levels stimulated a marked depletion of light cell granules as detected by electron microscopy and silver impregnation. In the hypercalcemic state the size and number of light cells did not differ from that of control animals. Hypocalcemic hamsters showed a significant increase in light cell numbers with marked hypertrophy and hyperplasia of this cell type. These observations support the view that the light cell in the hamster thyroid is associated with thyrocalcitonin secretion.
Abnormal sex cord formation and an intratesticular adrenal cortical nodule in a human fetus
Authors: Roosen‐Runge Edward C. , Lund Joanna
Published: February 2005

A combination of two developmental abnormalities never described before, a nodule of adrenal cortical tissue and some severely stunted sex cords, in the right testis of a four‐month‐old human fetus are described in detail. In the left testis a few abnormal cords were found but no adrenal tissue was seen. The possible origin of the abnormalities is discussed. It is suggested on circumstantial evidence that the ectopic adrenal cortex migrated into the testis near the end of the period during which the pattern of sex cords becomes established (around day 40 ?) and began exerting an inhibiting influence on the development of the sex cords as soon as endocrine function began, probably somewhat before the end of the third month. This influence probably did not last long.
On the expulsion of the erythroid nucleus and its phagocytosis
Authors: Skutelsky Ehud , Danon David
Published: February 2005

Electron microscopical examination of thin sections of guinea pig and rabbit bone marrow indicates that nuclei of their normoblasts undergo constriction during their expulsion.

Late erythroblasts in bone marrow of adult rabbits and guinea pigs were often seen surrounded by cytoplasmic protrusions of macrophages. No such contact was observed between macrophages and erythroblasts that were expelling their nuclei in the lumen of blood sinuses of rabbit bone marrow. It is concluded that macrophages are not necessary for nuclear expulsion.
Electromyography of sartorius muscle
Authors: Johnson C. Emory , Basmajian John V. , Dasher William
Published: February 2005

The sartorius muscle of ten normal subjects was studied by elec‐tromyography. It is most active during flexion of the hip and only slightly active during lateral rotation and abduction of the hip. The muscle is usually more active during knee flexion than during extension, but this is not universal. Apparently in some persons it plays a role in knee extension in addition to its knee flexion action, depending on knee position and variations in insertion. Sartorius appears to be a regulator in hip flexion and lateral rotation during the swing phase of gait.
Effect of injected human immunoglobulins on fetal rat development. Spinal, neural and osseous changes
Authors: Kamrin Benjamin B.
Published: February 2005

Rabbit anti‐rat‐brain serum immunoglobulins injected into pregnant rats on the ninth, tenth, eleventh or twelfth day of gestation resulted in a fetal resorption rate 15 to 30 times higher than that found in normal untreated pregnant rats. Human serum immunoglobulins obtained from normal postpartum mothers produced a similar percentage of fetal resorption when injected by the same routes into pregnant rats of the same gestational age. In neither of the above experiments were malformations detected among the delivered 20‐day fetuses. Injection of human serum immunoglobulins obtained from mothers of children with spina bifida manifesta into pregnant rats along similar routes and periods gave comparable fetal resorption rates. Injection of the above immuno‐globulin into the lumen of the uterus adjacent to implantation sites gave a low fetal resorption rate and produced varying degrees of skeletal and soft tissue malformations among the viable survivors.

The only difference which could be discerned between normal postpartum immunoglobulins and those obtained from mothers of spina bifida manifesta children was characterized in the latter by a two‐fold increase in the IgG levels and the immunoelectrophoretic reactivity of its immunoglobulins with human spinal cord antigens. The developmental defects observed were: 1. Cranial‐thinning and bleb formation of skull bones; widening of the foramen magnum; descent of the obex closer to the foramen magnum. 2. Skeletal‐delayed or inhibited calcification of the bodies and spinous processes of the thoracic and lumbar vertebrae; widening of the vertebral canal and central canal of the spinal cord.
The cytoarchitecture of normal mouse lens epithelium
Authors: Rafferty Nancy S.
Published: February 2005

The lens epithelium of 30 gm male albino CF1 mice was characterized by determining the area dimensions and the mitotic rate of the total and of the several different regions of whole‐mount preparations. A ring of nonpigmented iris cells is found to adhere to the outer surface of the lens cuticle, which serves to delineate an inner central zone from an outer peripheral zone of the epithelium. A high number of dividing cells in the peripheral area, especially immediately adjacent to the meridional rows, but including the area overlain by the iridial fringe of cells, identifies this wide region as the proliferative zone. The mitotic rate, furthermore, undergoes marked diurnal variation, rising in the late evening through the early morning hours and diminishing during the late morning and afternoon hours.
DNA replication and cell division in the hamster uterus
Authors: Krueger Wayne A. , Maibenco Helen Craig
Published: February 2005

Cell renewal in specific uterine tissues was studied by autoradiography in thymidine treated and thymidine, colchicine treated hamsters. All cell types were found to replicate DNA and to divide during the estrous cycle. However, tissue types differed in the extent of cell renewal and in the time during the cycle when maximal turnover occurred. Peak DNA replication by uterine epithelium, the most active tissue, occurred during the afternoon of the second day of diestrus. Connective tissue was the second most active cell type in DNA renewal; while connective tissue cells of the myometrium incorporated thymidine at a rather constant level throughout the cycle, those of the endometrium (stroma) fluctuated during the estrous cycle with peak labeling activity being found during the morning of the second day of diestrus. A few smooth muscle cells replicated DNA during proestrus but no labeled muscle cells were observed during the other stages of the cycle.

The extent of renewal of the different cell types in the hamster uterus during the estrous cycle is greater than that which has been reported in the rat. This difference may be due to timing of necropsy rather than to a species variation.
Causes of the zonal distribution of glycogen in the liver acinus after a fat‐rich diet. I. Glycogen deposition in the acini of rat livers during ‘normal’ ‘reversed’ perfusion
Authors: Otter W. Den , Tuit G.
Published: February 2005

Different acinar glycogen patterns are observed in rat liver after different diets. Experiments were carried out to determine if these patterns depend on the concentration of blood glucose in the various zones of the acinus or on the direction of the blood flow. It is possible to investigate this problem by reversal of blood flow in a perfusion apparatus. Livers were perfused with Krebs‐Henseleit solution, the same volume of bovine erythrocytes, and 379 mg% glucose, 2.5% albumin and different quantities of heparin. Perfusion in the normal direction is possible through the vena porta and in the reversed direction by perfusing through the vena cava. The reported results show that glycogen localization depends on the acinar enzyme pattern for glycogen synthesis rather than the direction of blood flow.
Crystal growth in rat incisor enamel
Authors: Selvag Knut A. , Halse Agnar
Published: February 2005

The width and thickness of hydroxyapatite crystals and the crystal density at various stages of rat incisor amelogenesis were studied using electron microscopy. The cross‐sectional profile of the crystals increased from 259 × 12.7 Å at the surface of the ameloblast to 454 × 249 Å in the completely mineralized enamel. In agreement with previous observations, many crystals had a regular, flattened hexagonal profile during the matrix formation stage. During enamel maturation, the crystals assumed more irregular surface contours, the crystals tending to adapt themselves to the available space. In completely mineralized enamel, the crystals were as irregular in shape as the crystals in human enamel, and they occupied around 85% of the volume. While the crystals at the onset of mineralization were separated by a distance of 120–150 Å, the crystals eventually became relatively closely packed, separated by a fine space only 10–25 Å in width. A lower number of crystals per unit cross‐sectional area of the enamel prisms was observed in fully mineralized enamel as compared with the early stages of amelogenesis. Since evidence of fusion of crystals is lacking, the decrease in crystal density appears to result from swelling of the enamel prisms.
Localization of cholesterol in peripheral nerve: USE of [3H] digitonin for electron microscopic autoradiography
Authors: Napolitano Leonard M. , Saland L. , Lopez J. , Sterzing P. V. , Kelley R. O.
Published: February 2005

Tritiated digitonin of high specific activity has been incorporated into fixation of adult rat sciatic nerve. Electron microscope autoradiograms developed four to thirteen days after coating indicate highest concentration of label over or near myelin sheaths. Label is observed over areas of reasonable myelin preservation as well as in areas of artifact and membrane disruption. The technique is suggested for use as a means of fairly specific localization of free cholesterol in tissues. In addition, the activity of the isotope used permits visualization of autoradiograms after short exposure times.
Surface patterns in the reproductive tracts of the rabbit observed by scanning electron microscopy
Authors: Kanagawa H. , Hafez E. S. E. , Pitchford W. C. , Baechler C. A. , Barnhart Marion I.
Published: February 2005

The ultrastructure of cell surface and tissue organization of reproductive tracts of female rabbits were observed by scanning electron microscopy. In the vagina, straight and shallow longitudinal folds were observed. Complex, very deep, narrow folds with small crypts were observed in the cervix uteri. Two types of cells were recognized: ciliated cells and secretory non‐ciliated cells. The internal os area contained more ciliated cells than the external os area. In the uterus, two different patterns of fold formations were observed: shallow fold formation in a random direction or mosaic pattern in the lower part of the uterus, and wave‐like folds in the middle or upper part of the uterus. The lower part of the uterus contained more ciliated cells than the mid and upper part of the uterus. At the uterotubal junction, four large folds and four small folds from the isthmus are projected into the uterine lumen forming a rosette‐like structure. In the oviduct, longitudinal fold formations were observed through the isthmus to ampullae. The number of ciliated cells gradually increased from the isthmus to the ampullae. The fimbriae, made of several mucosal folds arranged like flower petals, were composed of a high percentage of ciliated cells.
The persistence of a circadian rhythm in histamine response in guinea pigs maintained under continuous illumination
Authors: Scheving Lawrence E. , Sohal G. S. , Enna Carl D. , Pauly John E.
Published: February 2005

Adult guinea pigs were carefully standardized for at least seven days prior to each experiment; this included an artificial light‐dark cycle with light extending from 0600 to 1800. On three experimental days, eight animals were injected subcutaneously with 300 μg of histamine at six‐hour intervals over a 24‐hour period; each animal received four injections during one day. The size of the erythema produced each time was measured. In all three experiments a prominent group rhythm was demonstrated with maximum response occurring during the dark phase; minimum response always occurred during the latter part of the light phase. Such results indicate a strong synchronization among the animals of the group.

Two additional, similar studies were performed on animals standardized in one case for 21 days and in the second for 35 days under continuous illumination. The group rhythms of histamine response under these conditions, when compared to the light‐dark adapted group rhythm, were greatly modified in phasing and profile. The circadian rhythm in response to histamine persisted in each individual animal. The change in the phasing and profile of the group rhythm was due to a partial desynchronization among the individual animals subjected to continuous illumination.
Immunohistochemical and histochemical studies of pituitary β‐lipotrophs
Authors: Moon Henry D. , Li Choh Hao , Jennings Barbara M.
Published: February 2005

The presence of β‐lipotrophin or an immunologically similar substance was demonstrated in the intermediate lobe cells and some basophils of the anterior lobe by both fluorescent and peroxidase‐conjugated antibody methods. These basophils were found to be corticotrophs, i.e., reactive with anti‐ACTH. ACTH, when added to anti‐β‐LPH, decreased the fluorescence and peroxidase reactions of intermediate lobe cells and the anterior lobe corticotrophs. The addition of MSH to anti‐β‐LPH produced a slight decrease in the reaction between the intermediate lobe cells and anti‐β‐LPH. The intermediate lobe cells also reacted with anti‐ACTH. Both Somatotrophs and lactotrophs reacted with anti‐β‐LPH to give positive fluorescence or peroxidase reactions. However, the addition of STH to anti‐β‐LPH abolished the reaction between anti‐β‐LPH and somatotrophs. Similarly, LTH, when added to anti‐β‐LPH, abolished the positive reaction of lactotrophs to anti‐β‐LPH. When STH, LTH and ACTH were added to anti‐β‐LPH, the fluorescence of the somatotrophs and lactotrophs was abolished, whereas the corticotrophs maintained their fluorescence at a reduced intensity. These results indicate that the somatotrophs and lactotrophs do not contain β‐LPH and that corticotrophs contain β‐LPH.
An electron microscopic analysis of the nerve of the pterygoid canal in the mouse
Authors: Shimozawa Atsumi
Published: February 2005

Electron microscopic analyses of the greater petrosal nerve, the deep petrosal nerve and the nerve of the pterygoid canal near the point of their union in the mouse were made to clarify the courses of their fibers. Most of the nerve fibers of the greater and deep petrosal nerves passed through into the pterygoid canal nerve, but in some specimens a few nerve fibers (less than 100) coursed from the deep petrosal nerve to the greater petrosal nerve or conversely. Therefore, except for these, the source of the unmyelinated fibers of the greater petrosal nerve from the deep petrosal nerve may be eliminated; these fibers may be derived from the facial nerve proximal to the greater petrosal nerve.
Embryology of the sheep. III. The respiratory system, mesenteries and celom in the fourteen to thirty‐four day embryo
Authors: Bryden M. M. , Evans Howard , Binns Wayne
Published: February 2005

The day‐by‐day developmental changes which occur in the respiratory system, mesenteries and celom of the sheep embryo from 14 to 34 days coital age are documented chronologically and described. This work provides standards of normal development which can be used as a basis for future work on abnormal development of these structures.

The respiratory diverticulum which first appears on the seventeenth day is seen as a primitive lung bud on the nineteenth day and becomes bilobed on day 20. By the twenty‐first day a laryngotracheal tube is present and the larynx develops in the next ten days.

The dorsal mesogastrium forms on the eighteenth day and the omental bursa is seen as an invagination by the twenty‐first day. A splenic primordium associated with the omentum is present by the twenty‐seventh day.

The dorsal mesentery appears on the eighteenth day and undergoes torsion, herniation and coiling on the twentieth, twenty‐second and twenty‐seventh days. The ventral mesentery is present on the seventeenth day but disappears centrally between the eighteenth and twenty‐first days.

An extraembryonic celom is seen on the fourteenth day and the formation of the intraembryonic celom occurs on day 15. Development of the pleuroperitoneal membranes commences on the twenty‐first day. Complete separation of pericardial and pleural cavities is completed by the twenty‐eighth day.
Accumulation of lipid. Droplets in ventricular cardiac muscle of the bat following administration of parachlorophenylalanine: The influence of hibernation
Authors: Hagopian Martin , Gershon Michael D. , Nunez Eladio A.
Published: February 2005

The effect of the administration of p‐chlorophenylalanine on the fine structure of the ventricular cardiac muscle of active and hibernating bats was studied. The concentration of norepinephrine in the bat heart was also measured. In the active animal, p‐chlorophenylalanine induced a striking increase in the size and number of lipid droplets. Moreover, the lipid droplets exhibited an intimate association with mitochondria. The mitochondria in such associations showed extreme variations in form but exhibited normal arrangement of cristae. p‐Chlorophenylalanine also induced a slight increase in the number of glycogen granules but no other effects were apparent. During hibernation, the administration of p‐chlorophenylalanine failed to produce a change in either the size or number of lipid droplets. The concentration of norepinephrine in the heart of active and hibernating bats was not altered by the injection of the drug. The present findings indicate that lipid accumulation in ventricular myocardium following injection of drugs is not necessarily the result of depletion of cardiac stores of norepinephrine.
Electron microscopic and histochemical studies on the synaptic vesicles in mouse vas deferens and atrium after 5‐hydroxydopamine administration
Authors: Chiba Tanemichi
Published: February 2005

After administration of 5‐hydroxydopamine, one of the “false” adrenergic transmitters, core materials within both large and small vesicles of the adrenergic nerves increase in density, while clear vesicles in the cholinergic nerves do not change. In the vas deferens of the mouse, initial sign of the uptake is seen as early as one minute after intravenous administration. Eighty to ninety percent of vesicles in the adrenergic nerve varicosities are filled with dense cores by more than 100 mg/kg of 5‐OH‐DA administration. 5‐OH‐DA stored in the vesicles remains for seven to ten days and gradually disappears thereafter. After administration of 5‐OH‐DA, acetylcholinesterase (AChE) activity is examined in the nerve varicosities in the atrium. AChE activity in the adrenergic nerve fibers is discussed in the light of these findings.
Thyroxine and the development of the tibia in the embryonic chick
Authors: Hall B. K.
Published: February 2005

Embryonic chicks were treated with exogenous L‐thyroxine or with thiourea at eight days of incubation and the subsequent development of the tibia studied.

The weight of the tibia was 62% lower than that from normal embryos, and the length of the tibia 24% below normal in the embryos treated with thiourea. This reduced rate of growth was shown to be due to a reduction in the rate of maturation of chondroblasts into chondrocytes, reduced chondrocyte hypertrophy and defective deposition of acid mucopolysaccharide into the cartilage matrix. Osteogenesis per se was unaffected. It was concluded that thyroxine plays a role in the control of chondrocyte maturation and in cartilage matrix production during normal development.

The epiphyses of the tibiae from the embryos treated with thiourea were extensively eroded, invaded by marrow and more fragile than those from untreated embryos, indicating that thyroxine is essential for the maintenance of the integrity of the articular cartilage. An abnormal core of bone developed within the proximal epiphysis of these embryos.

Exogenous thyroxine at concentrations as low as 100 pg/embryo also reduced the growth of the tibia below that seen in untreated embryos. Evidently the cells of the skeleton are sensitive to both lowered and increased levels of circulating thyroxine.
Topology of the lateral nasal cartilages: The anatomical relationship of the lateral nasal to the greater alar cartilage, lateral crus
Authors: Drumheller Glenn W.
Published: February 2005

This investigation was undertaken to help fulfill the practical need of the rhinologic surgeon for a more accurate anatomical knowledge of the cartilages of the nasal tip.

Four adult caucasian noses aged 62–88 years were embedded en bloc and serially sectioned. The nasal cartilages of one were reconstructed in wax. Anatomical relationships of the lateral nasal cartilage to the lateral crus of the greater alar cartilage were compared. The findings were compared with descriptions found in the literature.

The lateral nasal cartilage curls to varying degrees laterally and upward on its inferior margin where it underrides the lateral crus of the greater alar cartilage. The curl is greater anteriorly and diminishes postero‐laterally to the point where the cartilage lies flat. The lateral crus of the greater alar cartilage also may curl medially and downwards on its superior margin where it overrides the lateral nasal cartilage. Sesamoid cartilages are present in all specimens.

These findings, although known to many rhinologic surgeons, are not clearly established in the literature.
Anatomical relationships of the cerebral and dural venous systems in the parasagittal area
Authors: Browder Jefferson , Browder Ann , Kaplan Harry A.
Published: February 2005

The cerebral and dural venous systems are derived from separate layers of the vascular plexus that cover the brain in early embryonic life. The cerebral veins arise from the inner layer of the plexus which invests the neural tube and join the dural systems in the superior midline concomitant with the development of the sinuses. The dural veins, the lateral lacunae and the dural sinuses arise from the outer embryonic plexus. In the fully developed human these two systems are separate except for an occasional communication between a lateral lacuna and a superior cerebral vein just before the vein joins the superior sagittal sinus. The lateral lacunae are a distinct anatomical entity and their venous meshwork is to be regarded as a part of the dural venous system.
Radiation induced abnormalities in early in vitro mouse embryos
Authors: Kirkpatrick Jay F.
Published: February 2005

Female mice were superovulated and mated, and the two‐cell embryos were collected and cultured in vitro. The embryos were exposed to x‐irradiation (0–491 rads) during the two‐cell stage, before the appearance of the next cleavage plate, placed in new unirradiated culture medium and observed during subsequent development. Morphological abnormalities which occurred as a result of irradiation included fragmentation, disintegration, granulation, incomplete cleavage, cleavage cessation, nuclear degeneration and pycnosis and cytoplasmic vacuolization. There was no damage to the zona pellucida.

The types of abnormalities indicated an agreement with the results of previous in vivo studies. A distinct correlation existed between morphological abnormalities and embryo death. The greatest number of abnormalities resulted within five hours following irradiation, but increased through 20 hours post‐exposure. At doses above 300 rads, the magnitude of damage was greater in the in vitro embryos than that shown in previous in vivo studies.
The organization of the contractile apparatus of vertebrate smooth muscle
Authors: Bois Richard M.
Published: February 2005

Smooth muscle of the small intestine of the rat was fixed by vascular perfusion employing aldehydes in a balanced salt solution, followed by immersion fixation in aldehydes and post‐osmication. In such tissue preparations thick filaments approximating 140 Å in diameter are observed in virtually all the smooth muscle cells. The thick filaments are rather uniformly distributed among the more numerous thin filaments. The nearest neighbor distances between the thick filaments range from 400 to 700 Å. The thick to thin filaments ratio is found to apporximate 1:12. Only thin filaments are observed in the most distal segment of terminal processes of muscle cells and the tips of these processes appear to be lined by attachment plaques. A clear segregation of the thick filaments from both dense bodies and attachment plaques is seen. Distally along the tapering extremities of muscle cells progressively more of the plasma membrane is found lined by attachment plaques. These observations are interpreted as strong evidence that the contractile apparatus of the vertebrate smooth muscle cell consists of interdigitating arrays of thick and thin filaments collated into contractile units by the anchoring of the thin filaments in dense bodies and attachment plaques.
Localization and correlation of catecholamine‐containing cells with adenyl cyclase and phosphodiesterase activities in the human fetal heart
Authors: Dail William G. , Palmer Gene C.
Published: February 2005

The present investigation attempts to correlate the appearance of catecholamines to receptor‐induced metabolic events (adenyl cyclase‐phospho‐diesterase) in the developing human heart. Adrenergic innervation, examined with the Falck‐Hillarp fluorescence technique as well as by electron microscopy, reveals the presence of catecholamine‐containing cells in or near the fetal heart at all ages studied (8–18 weeks). In most instances these cells occur either in association with extrinsic nerves along the aorta and pulmonary trunk or in the interatrial septum. Ultrastructural features of these cells include dense core vesicles. Acetylcholinesterase positive cardiac nerves and ganglion cells are observed. Highest basal activities of adenyl cyclase are found at the sixth fetal week. The enzyme is activated by fluoride ion from the eighth through the seventeenth fetal week, but not by catecholamines. Glucagon stimulates this enzyme at the seventeenth fetal week. Phosphodiesterase activity is progressively increased from the eighth to the seventeenth weeks and is inhibited by aminophylline from the tenth through the fifteenth week. Although catecholamine cells are present in the fetal heart, adrenergic fibers are absent at all ages studied. Failure to observe adrenergic fibers may correlate with the lack of hormonal activation of receptor mechanisms.
The sympathetic innervation of the cervical lymphatic duct of the dog
Authors: Todd Gordon L. , Bernard George R.
Published: February 2005

The sympathetic innervation of these ducts was studied by means of the Falck fluorescence histochemical technique and electron microscopy. A loose network of sympathetic fibers was observed on the surface of the lymphatic duct, yet there were large areas of the duct wall void of any fibers. The majority of the fibers branched from the plexuses of sympathetic fibers surrounding the vasa vasorum of the ducts. Sympathectomy experiments demonstrated the fibers do not travel up the vagosympathetic trunk or the carotid artery to reach the ducts, but apparently are carried along the plexuses of sympathetic fibers surrounding the smaller blood vessels outside the carotid sheath. The individual branches not accompanying any blood vessels would travel along the duct for distances up to several hundred microns, with occasional branches, to terminate without any specializations. The nerve fibers were encased in a Schwann cell sheath which in some cases only partially surrounded the fibers. Several of the axon profiles contained synaptic vesicles including small granular (or dense‐cored) and agranular vesicles and a few large synaptic vesicles. In all cases observed, the axons and their Schwann cell sheath were located in the adventitia outside the smooth muscle cells.
The development of the tibia in hypophysectomized chick embryos
Authors: Hall B. K. , Girouard R. J.
Published: February 2005

Chick embryos were hypophysectomized by partial decapitation at 33 hours of incubation and the subsequent morphogenesis and growth of the whole embryo and the growth, histology and histochemistry of the tibia studied.

Twenty‐five percent of the increase in body weight which normally occurs between 12 and 18 days of incubation and 60% of the normal growth of the tibia over the same period failed to occur in the hypophysectomized embryos. Histological studies indicated that the diminished skeletal growth resulted from reduced proliferation of chondroblasts within the epiphyseal growth zone and from reduced deposition of acid mucopolysaccharides into the cartilaginous matrix. The differentiation and hypertrophy of the chondrocytes produced in the hypophysectomized embryos was not affected. Therefore, the pituitary gland exerts considerable control over the development of the cartilaginous skeleton in the embryonic chick.

Osteogenesis was reduced as a consequence of the reduced chondrogenesis in the long bones from the hypophysectomized embryos.
The increase in skeletal muscle mass in male and female mice
Authors: Griffin G. E. , Goldspink G.
Published: February 2005

The total mass of skeletal muscle in male and female mice of strain 129/Re was found by removing the muscle from the bones using papain. The total muscle mass of male and female mice of under three weeks of age was not significantly different. After this time the muscle mass of male mice increased more rapidly and plateaued at a higher value than that of females. However, if the total muscle mass was plotted as a function of body weight then there was no significant difference between males and females. The percentage of body weight taken up by skeletal muscle was the same for males and females at all stages of development.
Changes in fat cell morphology during lactation in the mouse
Authors: Elias Joel J. , Pitelka Dorothy R. , Armstrong Rosa C.
Published: February 2005

A comparison was made of changes in the morphology of fat cells in the intact mammary gland, de‐epithelialized mammary fat pad, and the parametrial fat pad of female C3H mice during lactation. Mammary fat pad not in contact with actively secretory epithelium shows partial loss of fat during lactation (systemic effect) while in the presence of such epithelium there is much greater loss of fat (systemic plus local effect). In the same animal the parametrial fat pad shows greater depletion during lactation than the de‐epithelialized mammary fat pad. The extent of fat depletion is dependent on the number of nursing young and the duration of lactation. In the intact mammary gland and parametrial fat pad, marked change in fat cell structure is not seen in pregnancy except possibly at the very end; after weaning, replenishment of lactation‐depleted fat cells is conspicuous by 48 hours. The basic ultrastructure of mammary fat cells and the kinds of changes they undergo during depletion do not differ from those described for other mammalian adipose tissues.
The arterial supply to the lumbo‐sacral spinal cord in the monkey: A comparison with man
Authors: Fried Larry C. , Doppman John
Published: February 2005

This report compares the arterial supply of the lumbo‐sacral spinal cord in the monkey with that of man. The arterial supply to the lumbo‐sacral cord of 100 monkeys (82 Rhesus and 18 Mangabey) was demonstrated by perfusion techniques. We tabulated the level and side of origin of the great anterior medullary artery. Previous authors have shown that in man the peak incidence of the great anterior medullary artery is at T‐10. The peak incidence in the monkey is at L‐1. There are other features of the arterial supply to the lumbo‐sacral cord of the monkey that are different from man.
Conditions affecting the extracellular space in the frog's forebrain
Authors: Van Harreveld A. , Trubatch Janett
Published: February 2005

The forebrain of the isolated central nervous system of frogs was fixed by freeze substitution and studied with the electron microscope. The extracellular space (ECS) of brains kept for 15–20 min in a physiological salt solution at room temperature varied from an appreciable to a negligible one. In electron micrographs exhibiting a large ECS the tissue elements had a uniform electron density. The EMs with little space featured in some instances a moderate swelling of presynaptic terminals and other tissue elements. Brains kept in a cooled medium or a salt solution with MgCl2 added exhibited invariably an abundant ECS. Treating the brain with a 100 mM KCl solution 5–90 sec before freezing yielded EMs with a contracted ECS and swollen tissue elements, many of which could be identified as dendritic spines. This effect of KCl was in many experiments prevented by bathing the brain in a salt solution containing 10 mM MgCl2 or in a Ca‐free solution.
Growth and distribution of human fetal brown fat
Authors: Merklin Robert J.
Published: February 2005

Macroscopic and microscopic examination of adipose tissue was carried out in a series of 20 human fetuses, ranging in weight from 380–3032 gm, in an attempt to identify all areas of brown (multilocular) fat development and growth. Brown fat distribution in the human fetus takes the form of a highcollared vest affording coverage to the cervical, thoracic and abdominal viscera. Much of this fat lies deep within the body immediately outside the pleural and peritoneal membranes. the remainder overlies or borders muscles of the shoulder girdle and neck as distinct brown fat deposits deep to the subcutaneous layer of white (unilocular) fat. All brown fat bodies contain unilocular cells but they occur in very small numbers in the brown fat bodies of the posterior cervical triangle, anterior mediastinum and perirenal and suprailiac regions. Brown fat bodies usually develop along the course of large blood vessels and several of them develop direct vascular connections with the liver and kidneys. The total weight of fetal brown fat increases at a rate directly proportional to that of the liver and kidneys up to 2134 gm body weight and to that of the liver beyond this weight.
The popliteal node assay for graft‐versus‐host interaction in mice. I. Location and proliferation of donor and host cells within the popliteal node
Authors: Monié Herbert J. , Everett N. B.
Published: February 2005

A parental (CBAT6T6) lymph node cell suspension was injected into the hind footpad of F1 (CBA × C57BLKs) recipients. The resulting increase in the recipient's popliteal lymph node weight was linearly related on double log plots to the number of parental lymph node cells injected. The node weight response was biphasic including an initial rise, a maximum weight gain at seven to nine days and a gradual decline to normal weight. When the long‐lived small lymphocyte population of the donor was labeled with 3H‐thymidine, the location, morphology and mitotic activity of labeled cells was followed by radioautography. These cells were most frequently observed in the mid‐ and deep cortex and the medullary cords of the host node. Very few labeled blast cells were observed in sections or smears and radioautographs of chromosome spreads confirmed the infrequency of donor long‐lived small lymphocyte transformation and proliferation. Of the proliferating cells in the host node at the peak of the response, 60–85% were of host origin. These observations and others are discussed, and it is proposed that the host short‐lived small lymphocyte accounts for the majority of mitotic cells in the node at the peak of the response.
Distribution of 125I‐labeled human growth hormone in immature, hypophysectomized rats pretreated with ACTH or unlabeled human growth hormone
Authors: Mayberry H. E. , Waddell William J.
Published: February 2005

Whole‐body autoradiograms were prepared from intact and hypophysectomized (Hypox) rats after receiving 125I‐HGH iv. In addition, some hypox rats received unlabeled HGH or ACTH six minutes before receiving the 125I‐HGH. Hypox rats had greater concentrations of radioactive material in the renal cortex, adrenal cortex, liver and submandibular gland than was present in blood. Pretreatment with ACTH increased the radioactive material in the inner zones of the adrenal cortex; liver and renal cortex contained more radioactive material than blood; and the submandibular gland contained an amount equal to that in blood. Pretreatment with unlabeled HGH greatly suppressed uptake of radioactivity in liver and adrenal cortex and slightly increased the uptake in the renal cortex. Radioactivity could not be detected in the renal medulla or urine of any of the rats. No concentration of radioactive material greater than that seen in blood was present in any other organ or tissue in any of the groups. In the intact rats, the kidney and the adrenal cortex had the greatest concentrations of radioactivity, while the concentration in the liver was equal to that in blood. Autoradiograms were also prepared from sections from untreated hypox rats that were dipped in 125I‐HGH solutions. These confirmed the presence of binding sites in the adrenal cortex and liver for 125I‐HGH. No binding of radioactive material was seen in the kidney.
Subsurface cisterns in mouse hepatocytes
Authors: Tandler Bernard , Hoppel Charles L.
Published: February 2005

Extensive subsurface cisterns were commonly found beneath the apposed plasmalemmas of adjoining hepatocytes in young and adult mice. The cisterns were of two types: (1) flat cisterns, often with ribosomes on their deep surface, and (2) flattened, highly fenestrated smooth surfaced saccules, some of which were in continuity with smooth endoplasmic reticulum. Despite their frequent occurrence, the subsurface cisterns were always absent from the regions of gap or tight junctions, as well as from the periphery of bile canaliculi and cell surfaces bordering the space of Disse. The function of these cisterns remains undetermined.
Morphological plasticity in the wall of the third ventricle during the estrous cycle in the rat: A scanning electron microscopic study
Authors: Brawer James R. , Lin Peck Sun , Sonnenschein Carlos
Published: February 2005

The ependymal tanycytes lining the ventral basal region of the third ventricle were studied in female rats during different stages of the estrous cycle. At mid‐diestrus, the apical membranes of tanycytes were shown to be devoid of microvilli and of other surface irregularities. During proestrus, a multitude of microvilli and small bulbous protrusions characterize this region of the ventricular wall. These surface disruptions persist through estrus and disappear during diestrus. In addition, so‐called supraependymal cells were observed and counted. Their numbers also vary with respect to the estrous cycle. The significance of these changes is discussed with respect to a possible mechanism for transporting substances from the cerebrospinal fluid (CSF) to the parenchyma of the hypothalamus and to the circulation.