bluuebunny/crossref_metadata_2025_split huggingface dataset:
Primary structure of the long and short splice variants of mouse collagen XII and their tissue‐specific expression during embryonic development
Authors: Böhme Kathrin , Li Yefu , Oh Paul S. , Olsen Bjorn R. 
Published: February 2005

AbstractType XII collagen, a member of the FACIT group of extracellular matrix proteins, consists of molecules that are trimers of α1(XII) chains. The three chains in each molecule form a cross‐shaped structure with a central globule from which a triple‐helical tail and three finger‐like regions (containing von Willebrand factor A‐like domains and fibronectin type III repeats) extend. cDNA cloning/sequencing of chicken α1(XII) collagen and protein studies with mouse, bovine, and human material suggest that the α1(XII) collagen gene gives rise to two molecular variants, differing in the length of the finger‐like regions, by alternative splicing of the primary transcript. To provide a basis for studies of the function of the two variants in an organism that can be genetically manipulated, we have isolated and sequenced mouse cDNAs encoding both splice variants. The sequence provides the first complete nucleotide and amino acid sequence of mammalian type XII collagen. From these cDNAs we have generated digoxigenin‐labeled RNA probes for in situ hybridization of developing mouse embryos to find out whether the splicing mechanism responsible for generation of the two forms is developmentally regulated. The results, combined with Northern blot and RT‐PCR analysis of RNA from embryos at various developmental stages, demonstrate that the long form of collagen XII, XIIA, is the predominant form at early stages (ED7 and 11); at later stages of development (ED15 and 17) the short form, XIIB, becomes the major form. As the short form becomes the major product, the long splice variant continues to be expressed in several tissues, even after birth. An exception is dermis, which is positive for the long form up to embryonic day 15, but negative at day 18, when only the short form RNA can be detected. © 1995 wiley‐Liss, Inc.
Differential effects of retinoic acid and a retinoid antagonist on the spatial distribution of the homeoprotein Hoxb‐7 in vertebrate embryos
Authors: López Silvia L. , Dono Rosanna , Zeller Rolf , Carrasco Andrés E. 
Published: February 2005

AbstractAn antibody raised against the recombinant Xenopus laevis Hoxb‐7 protein (López and Carrasco [1992] Mech. Dev. 36:153–164) recognizes the 30 kDa translation product of the Hoxb‐7 gene in X. laevis and the cognate nuclear protein in chicken embryos. The X. laevis Hoxb‐7 protein was expressed maternally and zygotically. Treatment of X. laevis and chicken embryos with either all‐trans retinoic acid (RA) or the retinoid antagonist Ro 41–5253 (Ro; Apfel et al. [1992] Proc. Natl. Acad. Sci. U.S.A. 89:7129–7133) during early development induced malformations of the neural tube and complementary changes in the expression domain of the homeoprotein Hoxb‐7. Treatment of X. laevis embryos with retinoic acid during gastrulation induced an anterior shift of the Hoxb‐7 expression domain and was correlated with an enlargement of rhombomere r7. In addition to a reduction in rhombomere numbers and of forebrain size, various malformations involving all three germ layers were observed. Treatment of X. laevis embryos with the antagonist Ro before or during gastrulation caused a progressive reduction of the Hoxb‐7 domain and also dose‐dependant malformations of all three germ layers. RA or Ro treatment of chicken embryos from the beginning of gastrulation caused changes of the Hoxb‐7 expression domain very similar to those observed in X. laevis. In particular, either a dose‐dependant loss of the Hoxb‐7 protein in the neural tube or an ectopic expressionin the forebrain region was observed. The results of this study indicate that endogenous retinoids regulate the spatial expression of homeobox‐containing genes in vertebrates. © 1995 wiley‐Liss, Inc.
The density of organic and volatile and non‐volatile inorganic components of bone
Authors: Gong J. K. , Arnold J. S. , Cohn S. H. 
Published: February 2005

AbstractDensities of the various bone fractions i.e., water, organic, volatile inorganic and ash fractions, as well as fat in the various animals have been studied. However. values reported by various workers failed to show consistency and uniformity, especially with respect to the volatile inorganic (often called “CO2 fraction”) and the ash fractions. These densities are prerequisite to the study of the volumetric composition of bone and bone marrow.In our study, the fat and organic densities found were similar to those previously reported. The volatile and non‐volatile inorganic (ash) fractions, had density values of 1.684 and 3.180, respectively. The ash density was much higher than values previously reported but it verifies a theoretical value deduced by the authors from published work.Our higher ash density was due to a smaller measured volume of this fraction obtained by applying a negative pressure to remove the small entrapped air bubbles from the ash sample prior to the water displacement measurement. Because a smaller portion of the total inorganic volume was used for the ash calculation, giving it a higher density, a larger balance of the total inorganic volume was left for the volatile inorganic density calculation. This accounted for ash and volatile inorganic densities which were higher and lower, respectively, than such values previously reported.Prior to the determination of the density of the non‐volatile inorganic fraction, the ashing time and temperature were studied. Curves plotted from the results of such studies were described and explained.
Composition of trabecular and cortical bone
Authors: Gong J. K. , Arnold J. S. , Cohn S. H. 
Published: February 2005

AbstractA technique was devised for obtaining marrow‐free trabecular bone so that the trabecular and cortical bone composition of dog, steer, monkey and man could be studied. Vertebral body was cut in the frontal plane into slices 2 mm thick with an electric band saw. The cortical bone encrircling each slice was trimmed off with a cleaver, leaving intact a lacy slice of trabecular bone. The marrow substance was washed away by fine and powerful jets of tap water obtained from an adjustable nozzle. Marrow washing was discontinued when no trace of red color was visible on holding the slice in front of a strong light source.The quantities of water, volatile inorganic, organic and ash fractions in cortical bone was alike for all species. Likewise, the trabecular bone fractions of each was quantitatively similar. In general, density and amount of ash in cortical bone was higher than that in trabecular bone. The water and ash:organic ratio were higher in trabecular than in cortical bones.Ratios of trabecular to cortical ash for the bones in an entire dog skeleton were also determined. Based on this, volume or mass of the various bone fraction may be estimated when the weight of the ash for any particular bone is known.
Histochemical studies of the human fetal thyroid during the first half of fetal life
Authors: Shepard Thomas H. , Andersen Helge , Andersen Henning J. 
Published: February 2005

AbstractA number of histologic and histochemical techniques have been used to study 42 human fetal thyroids from fresh specimens ranging in crown‐rump length from 22 to 201 mm. Three periods of differentiation (colloid production) were defined. The first or precolloid stage was found in fetuses of 22 to 65 mm and consisted of strands of compact epithelial cells separated by loose connective tissue which contained only a few vessels. The early colloid production period from 65 to 80 mm was characterized by the appearance of small accumulations of colloid in the center of the follicles. The blood vessels between follicles increased during this period. In the last period during maturation of the colloid cavities, the spaces between the epithelium were more reduced and almost completely filled with blood vessels. No change in the average cell height was found during differentiation.With differentiation, the nuclei of epithelium became less compact and RNAase‐removable cytoplasmic material increased. Also of interest was the marked decrease in glycogen at the time of colloid production.The staining characteristics of the early colloid showed little change during the period studied. The colloid was stained by the following reagents: periodic‐acid Schiff, mercury organge, toluidine, ninhydrin‐Schiff, Millon's and Sakaguchi's. The larger colloid spaces took slightly more toluidine stain than the smaller ones.The enzyme reaction for alkaline phosphatase was found only in the vascular system, and acid phosphatase was found in the cytoplasm of epithelium and, especially in the differentiated specimens, it was concentrated at the apex of the cell. Lactic and succinic dehydrogenase activity did not seem to change with maturation and was located in the cytoplasm around the nucleus and toward the apex of the cell.Thin rays of colloid‐like material were observed to radiate out between cells from early colloid cavities. Based on unpublished electron microscopic data, organ cultures of human thyroid and observations from the developing chick, these spaces probably represent intercellular dilatations which have been filled with colloid from the central cavity. These spaces may be a secondary or safety mechanism which allows the circumference of the follicle to increase in size.
Electron microscopy after rapid freezing on a metal surface and substitution fixation
Authors: van Harreveld A. , Crowell Jane 
Published: February 2005

AbstractA method for rapid freezing is described in which use is made of the good heat conducting properties of silver. The freezing was accomplished by bringing the tissue in contact with a polished silver surface at the temperature of liquid nitrogen either at atmospheric or reduced pressure. Helium gas flowing over this surface prevented the condensation of water or air on the silver. After freezing the tissue was placed in a substituting solvent. The best results were obtained with 2% osmium tetroxide in acetone at −85°C. The ultrastructure of the tissue was well preserved in a narrow surface layer only.
The proliferative activity of the adrenal cortex using a radioautographic technic with thymidine‐H3
Authors: Hunt Thomas E. , Hunt Eleanor A. 
Published: February 2005

AbstractProliferative activity of the adrenal cortex was studied following injections of thymidine‐H3. Normal male Long‐Evans rats had less activity than comparable animals of the Sprague‐Dawley strain. Of the Long‐Evans rats killed at different hours of the day, those injected with thymidine‐H3 at 6 P.M. and killed six hours later had the greatest activity. Normal male rats 35 to 73 days of age had almost all activity in the glomerulosa and outer fasciculata of the cortex. This activity was greatly increased two or three days after injecting colchicine, compound 48/80, or carbon tetrachloride. Such stressing agents did not cause any increase in activity during the first 24 hours. Three days after carbon tetrachloride a considerable increase in proliferative activity occurred in the inner zona fasciculata and reticularis of the adrenal of female rats during diestrus. Male rats killed 28 to 40 days after injecting thymidine‐H3 showed no evidence of centripetal migration of cells into the reticularis during that time. The absence of centripetal migration and the marked responsiveness of the inner fasciculata and reticularis of female animals after stressing agents supports the zonal theory of function in the adrenal cortex.
Thymus gland fractionation and thymocyte lysis
Authors: Schneider Rose Mary 
Published: February 2005

AbstractMethods are described for the isolation of two separate fractions from guinea pig thymus gland; i.e., Hassall's corpuscles and stromal segments. Hassall's corpuscles are relatively dense epithelial aggregates sedimentable at low centrifugal acceleration, while the lighter stromal segments remain in the supernatant fluid. Solubilization of the thymocytes, effected by high‐speed homogenization in hypertonic glycerol, is unaccompanied by visible gelation or nuclear residue. Glycerol‐sensitivity resembles radiation‐sensitivity in many respects.
Epiphyseal ossification and shaft elongation in human metatarsal bones
Authors: Roche Alexander F. 
Published: February 2005

AbstractMeasurements of the lengths of the shafts of the third, fourth and fifth metatarsals have been made on serial standarized radiographs of white Australian children. A statistical analysis showed that, in the boys, there were no real differences between the rates of elongation of the shafts during periods when the corresponding epiphyses became radio‐opaque and those that occurred during earlier or later periods. There was a statistically significant tendency in the girls for rate of elongation of metatarsals to be more rapid before radio‐opaque changes in epiphyses were noted than after.
On the innervation of the blood vessels in the human foot
Authors: Mustalish Anthony C. , Pick Joseph 
Published: February 2005

AbstractWith the aid of a Zeiss operation microscope, a dissection was made of the nerves to the blood vessels of the dorsum and sides in the two feet of the cadaver of an adult man. No obvious vascular nerve issued from the saphenous nerve. The terminations of the dorsal metatarsal and interdigital arteries and veins over the two medial thirds of the dorsum of the foot were supplied by extremely thin nervelets which originated chiefly from the medial branch of the superficial peroneal nerve. The sural nerve issued conspicuous filaments to the lateral interdigital and metatarsal blood vessels, to the lateral calcaneal arteries and to the talo‐calcaneal region. These findings provided a firmer anatomical basis for the interruption of the vascular nerves of the dorsum and sides of the foot by blocking with analgesic agents or by crushing the superficial peroneal, sural and saphenous nerves above the ankle.
Glomerular localization of intravenous Alcian blue
Authors: Parsons Donald A. , McManus J. F. A. 
Published: February 2005

AbstractThe anatomical and histological picture following intravenous injections of several concentrations of aqueous solutions of Alcian Blue has been described. Alcian Blue granules can be found in all cases within the reticulo‐endothelial cells of the body in lungs, spleen, liver and bone marrow and in the kidney.The greatest concentration of the dye is found within the renal glomeruli. It is in such concentration as to enable one to see individual glomeruli with the 10 × magnification of the dissecting microscope. On high power (950 ×) the dye can be seen as granules within the endothelial cells and podocytes of the glomerulus, as well as in the cells of the glomerular stalk. No Alcian Blue has been identified within the macula densa.Certain difficulties due to the solubility of the dye in sections are mentioned. Present means of meeting them are covered. Also discussed are follow‐up studies being undertaken and possible implications of the procedure.
The ultrastructure of human embryonic myocardium
Authors: Leak L. V. , Burke J. F. 
Published: February 2005

AbstractHuman embryonic myocardial tissues ranging from eight to eighteen weeks of development were prefixed and dissected in buffered formaldehyde, postfixed in buffered OsO4 and processes for Epon embedding. At these stages of development the myocardial cells contain an abundance of sarcoplasm with a sparse random distribution of myofibrils that frequently appear branched. The A, I and Z bands exhibited in the adult myocardial cells are also observed in these stages of development. However, the M line is only slightly apparent, while no H band was observed. The mitochondria are not arranged in parallel arrays as found in the adult, but appear to be randomly distributed throughout the interfibrillar sarcoplasm. An array of tubules, cisternae and vesicles that comprise the sarcoplasmic reticulum is also distributed throughout the interfibrillar sarcoplasm. In some areas this tubular system appears as vesicles with small dense granules along its outer surface, while in other areas it appears smooth. The distribution and orientation of the sarcoplasmic reticulum is far less pronounced in the embryonic stages examined in this study than that reported for the adult myocardium. Dense granules (150 to 350 Å) appear as clusters or aggregates of granules in the sarcoplasm and are similar to the glycogen granules described by other investigators. The intercalated disc is observed at the junction of two opposing cells and occurs with less frequency than the intercalated disc in the adult myocardium.
Myocardial fiber size and capillary‐fiber ratio in the right and left ventricles of the rat
Authors: Angelakos E. T. , Bernardini P. , Barrett W. C. 
Published: February 2005

AbstractHistological techniques were used to obtain fiber counts, capillary counts, fiber diameters, and capillary‐fiber ratios in the adult rat heart. Based on measurements of 3,600 fibers in six rats, the means and standard deviations of the fiber diameters for the left and right ventricles were 11.8 ± 4.8 and 11.5 ± 4.3 μ respectively. The corresponding capillary‐fiber ratios were 0.92 ± 0.23 and 0.90 ± 0.33. The differences between the right and left ventricles were not statistically significant. Statistical analysis was used to evaluate the reproducibility of the results. The frequency distribution of the fiber diameters was found to be unimodal in both right and left ventricles suggesting that only one group of fiber sizes is involved. It was found that fiber counts could be used as an indication of fiber size under ordinary conditions provided that the total number of fibers counted is over 200.
The histochemical distribution of β‐galactosidase activity in the ovary and female genital tract
Authors: Bulmer D. 
Published: February 2005

AbstractIn the female genital system of the rat the only organ to give a strong histochemical reaction for β‐galactosidase with the post‐coupling technique is the ovary, where strong staining occurs in the corpora lutea, the interstitial cells and some of the macrophages. In the uterus and vagina the relatively weak reaction is restricted to the epithelia, and is reduced by ovariectomy. During pregnancy the decidua shows marked activity, but in the portions of the uterus which are not involved in placentation the reaction is still restricted to the epithelium. The mucified vaginal epithelium of late pregnancy is moderately reactive. In the rabbit ovary the activity is strong, with intense staining in interstitial cells; in the ovaries of the guinea pig and monkey it is much weaker.Though β‐galactosidase is considered to be mainly lysosomal, its ovarian distribution differs in some respects from the distribution of acid phosphatase. The relative intensities of the ovarian and uterine reactions in the rat, as shown histochemically, do not appear to correspond with biochemical findings.
The pelvic and perineal fasciae and their neural and vascular relationships
Authors: Roberts W. H. , Habenicht James , Krishingner Gene 
Published: February 2005

AbstractThis study was based upon a dissection of the pelvic fasciae and associated structures of one hundred and three adult pelves as well as those of three full term fetuses. The perineal fasciae and their neural and vascular relationships were studied in an additional 55 specimens.The uterovaginal fascia, as stated by others, is a well‐defined structure. One is usually able, on the basis of a fascial cleft, to distinguish readily between the fascial sheath of rectum proper and the deeper layer of subperitoneal fascia, called by some the presacral fascia. The latter is described, including the relationship of the pelvic autonomics thereto. The relationship of the vesical branches of the pelvic plexus and of the venous plexuses to the terminal ureter are also described.We were able to confirm the presence of a superficial and a deep perineal fascia; the latter forms the inferior boundary of the superficial perineal space proper, as described by others. The relationship of particular nerves (and vessels) to the fascial planes of the perineum follows a definite pattern even when variation from the normal is present.
Action of the pterygoideus muscle during feeding in the lizard Uromastix aegyptius (Agamidae)
Authors: Throckmorton Gaylord S. 
Published: February 2005

AbstractThe actions of the deep and superficial portions of the ptery‐goideus muscle and the depressor mandibulae were studied in the agamid lizard, Uromastix aegyptius, using fine wire electrodes. The EMG signals were recorded, while simultaneously recording the jaw positions during feeding on movie film at 32 fps. Muscle activity varies with different types of food. The deep and superficial portions of the pterygoideus performed different functions. The deep ptery‐goideus functioned during opening of the jaws, presumably to protract the jaw. The superficial pterygoideus was strictly a jaw elevator. The depressor mandibu‐lae is not the initiator of jaw opening. When biting on tough food items, the deep pterygoideus and depressor mandibular were active.
Extracellular coat in developing human palatal processes: Electron microscopy and ruthenium red binding
Authors: Meller Samuel M. , Barton Lorraine H. 
Published: February 2005

AbstractThe prefusion epithelium of human palatal processes was examined for evidence of specialization which might facilitate epithelial adherence with the opposing palatal process. A surface coat stained with ruthenium red (RR) was found on all apical aspects of the palatal epithelium. In the prefusion regions, RR staining was also observed in the spaces between the superficial cells of the epithelium and in necrotic cells. Adjacent oral and nasal epithelium excluded the RR below the level of the apical junctional complex. In the absence of RR, a dense material was observed in the most superficial intercellular spaces of the prefusion region. Many superficial cells in the area were in various stages of necrosis. The combination of degenerating surface cells and an accumulation of a poly‐anionic substance such as glycoprotein may facilitate epithelial adherence between opposing human palatal processes.
Experimental studies on the acetylcholinesterase‐positive nerves in the ovary of the rat
Authors: Burden Hubert W. , Lawrence Irvin E. 
Published: February 2005

AbstractAdrenergic and acetylcholinesterase (AChE)‐positive nerves were studied in the rat ovary four days after various experimental denervation procedures. Ablation of pelvic parasympathetic nerves (pelvic neurectomy [PN]) or abdominal vagotomy (AV) had no obvious affect on the adrenergic or AChE‐positive nerves in the ovary. Section of the mesovarium resulted in the loss of all histochemically demonstrable adrenergic and AChE‐positive nerves. Chemical sympathectomy with 6‐hydroxydopamine (6‐HD) resulted in the loss of all histo‐chemically demonstrable adrenergic nerves. A few AChE‐positive nerves remained in the hilar and medullary regions following chemical sympathectomy. When the presumptive parasympathectomy procedures (AV and PN) were combined with chemical sympathectomy, again no adrenergic nerves remained, however a few hilar and medullary AChE‐positive fibers persisted after sympathec‐tomy plus PN, but no AChE‐positive fibers were demonstrable in the AV plus 6‐HD group.These findings show that most of the AChE in ovarian nerves is localized in adrenergic nerves. It is suggested that the few AChE‐positive fibers remaining in the ovarian hilar area after 6‐HD treatment or 6‐HD plus PN are derived from the vagus. These few AChE‐positive nerves may be postganglionic vagal parasympathetic or they may be sensory fibers.