bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effects of unilateral ovariectomy on follicular maturation in the guinea pig
Authors: Hermreck Arlo S. , Greenwald Gilbert S. 
Published: February 2005

AbstractA control group of guinea pigs ovulated 3.43 ± 0.41 ova or 1.72 ova per ovary. Unilateral ovariectomy (semispaying) on day 1 resulted in the ovulation of 3.71 ± 0.37 ova from the remaining ovary, whereas after semispaying on days 5 and 10, 2.80 ± 0.12 eggs were ovaluated. Unilateral ovariectomy during days 12, 14 and just prior to ovulation resulted in the same number of ova being ovulated from the remaining ovary as from the initial ovary removed. Semispaying at any day during the cycle did not alter cycle length.At day 1, all follicles from the previous cycle were atretic. At day 5 the current population of follicles were well developed with no atresia present. Ovaries removed on days 5, 10, and 12 had approximately the same distribution of large follicles with atresia appearing in all size ranges. At day 14, the number of large follicles was markedly decreased. However, after semispaying at day 5, the remaining ovary at day 14 had twice the number of Graafian follicles and twice the amount of atresia in these size ranges as the normal day 14 ovary.It is therefore likely that the compensatory response after unilateral ovariectomy in the guinea pig is due to an increase in the rate of proliferation of smaller sized follicles into larger ones. Day 12 seems to be the critical period of the guinea pig cycle. At this time, regression of the corpora lutea occurs, and perhaps of significance, the ability of the animal to compensate for unilateral ovariectomy is also lost.
Microradiography of the pulmonary microcirculation
Authors: Quigley Mervyn B. , Leathers James E. , Reeves John T. 
Published: February 2005

AbstractConventional radiographs of lungs of calves which had been injected post mortem with barium sulphate could not be used to demonstrate vessels smaller than 50 μ in diameter. To overcome this difficulty, frozen sections 50–150 μ thick were floated on to high resolution photographic plates and contact microradiographs made using soft radiation. The resultant microradiogram was then viewed and photographed with the light microscope. It was possible to visualize the smaller arterioles and the capillary networks around the alveoli. The technique is simple and gives reproducible results.
Uptake of colloidal particles by cells of the caput epididymidis
Authors: Burgos Mario H. 
Published: February 2005

AbstractColloidal mercuric sulfide injected into the rete testis adhered to the stereocilia of the epithelial cells and subsequently moved into a highly developed canalicular system in the apical cytoplasm. The canalicular invaginations of the cell surface arising between the stereocilia lead to cytoplasmic vacuoles that concentrate the particulate matter. The limiting membrane of the stereocilia and of the canaliculi and vacuoles is covered by a layer of amorphous material. It is speculated that this may bind particles, molecules, and ions as does an ion exchange resin, and that it may, in this way, act as a carrier in the uptake and transport of substances by cells.
Mucosal enzymes in the cecum of conventional and germfree mice
Authors: Jervis Helen Roland , Biggers David C. 
Published: February 2005

AbstractThe morphology of the cecal mucosa and the topographic distribution of certain mucosal enzymes were compared in conventional and germfree mice to investigate the phenomenon of cecal enlargement observed in germfree animals. The cecal mucosa is predominantly non‐villous in the conventional, but has a villous structure in the germfree mice. Alkaline phosphatase, in the conventional mice, is present in the striated border of a limited number of the epithelial cells lining the cecum; in the germfree mice almost all these epithelial cells show enzymatic activity. Acid phosphatase is more abundant in the epithelial cells and macrophages of the cecal mucosa of the conventional than of the germfree animals. Both groups show similar monoamine oxidase and reduced diphosphopyridine nucleotide diaphorase activity. The reduction of the villi, and the decrease in alkaline phosphatase activity in the conventional mice point to an involution of the mucosa as an absorptive organ. Barka ('63) has suggested that acid phosphatase may have a defensive function; its increase in the conventional animal would support this interpretation. The two oxidative enzymes studied apparently are not influenced by the intestinal flora.
Changes induced by sustained pressure in the knee joint articular cartilage of adult rabbits
Authors: Crelin E. S. , Southwick W. O. 
Published: February 2005

AbstractThe right knees of rabbits were rigidly fixed with metal clamps midway between full flexion and full extension. After six dayas the knees of six were preserved while clamped. Twenty other rabbits were sacrificed after 16 days. Ten received colchicine on the eighth, eleventh and fifteenth day following clamp application. Their knees were preserved after clamp removal. The femoral and tibial articular cartilages subjected to pressure for six days were extremely compressed but viable. In knees clamped for 16 days the changes found were related to the amount of knee movement present at autopsy. Where it was small but easily detectable the cartilages were normal. Where there was no movement the cartilage was dead. Where it was only slight variable cartilage changes were found ranging from surface abradement, Matrix swelling, enlargement of lacunae and chondrocytes, increased number of cells per lacuna, and an occasional chondrocyte in mitosis, to an extensive matrix alteration resulting in the disappearance of lacunae, chondrocytes released from the confines of lacunae and interspersed among a meshwork of fine collagen fibers, and a few released chondrocytes in mitosis. The most extensive change was where the cartilage defect area was occupied by a mass of proliferating richly‐cellular tissue. The knee articular cartilage changes of this experiment are compared with those occurring during pregnancy in the pubic symphyseal cartilage of mice.
Experimental heart‐block in the chick embryo
Authors: Paff George H. , Boucek Robert J. , Klopfenstein Harold S. 
Published: February 2005

AbstractWhile studying the electrocardiograms of developing hearts it was noted that an adult type ECG could not be obtained in an embryonic heart which could not be blocked with digitalis. The need to know more about heart‐block was obvious. Intact embryos of 36 to 120 hours were floated on to glass plates and treated with digoxin‐Tyrode solution. Before 36 ± hours no dissociation of beat could be produced. The heart just stopped. At 40 ± hours a conal block followed by a midventricular block appeared. At 42 ± hours conal and midventricular blocks were followed by the first appearance of AV block. It was intermittent. At 47 ± hours conal block jumped to an incisive AV block. Midventricular block was rare. At 72 hours conal and then AV block occurred. Combinations such as four atrial to two ventricular to one conal beat could be readily produced while blood circulated.Electrocardiograms and cinephotomicrographs were taken of 72 and 96 hour hearts. Most striking was the fact that the typical Wenckebach phenomenon of adult heart‐block could be duplicated, i.e., an increase of PR interval preceding AV block followed by a shorter PR interval which again gradually increased preceding AV block. This sequence was repeated over and over. An explanation of these events is offered.
Alterations in submandibular and retrolingual glands following parasympathetic denervation in rats
Authors: Peronace Angela A. V. , Davison Tomás A. , Houssay Alberto B. , Perec Carlos J. 
Published: February 2005

AbstractAlterations in size and structure of submandibular and retrolingual glands of the rat produced by unilateral sectioning of the chorda tympani, or the lingual nerve, or the glandular branch which leaves the lingual and innervates both glands, are described. The glands were studied 1, 2, 4, 8, 12 and 16 days after nerve section.The weight of the glands increased the first day after nerve section and decreased markedly from then on, reaching 40 to 70% of the initial weight after 16 days. In the glands where the chorda tympani or the lingual nerve were sectioned the increase in weight was attributed to the accumulation of secretion in the acinous cells. After that, a progressive atrophy developed, being more severe in the acini than in the tubes. In the cases where the glandular nerve was sectioned a wide necrosis probably of vascular origin was produced, followed by parenchymatous regeneration.In both cases 16 days after nerve section glands were small, fibrous and with little parenchyma.The role of the parasympathetic nerves in controlling the normal structure of submandibulars and retrolinguals is discussed.
Changes in the vertical dimensions of the human male skull during the third and fourth decades of life
Authors: Thompson John L. , Kendrick George S. 
Published: February 2005

AbstractA cephalometric radiographic appraisal of vertical skull growth occurring during the interim of one year was made on 71 caucasoid males at the Baylor University College of Dentistry, Dallas, Texas. The subjects were from 22 to 34 years of age. The dimensions assessed were the total skull height, the anterior cranial height, total facial height, upper facial height. and lower facial height. A significant increase was shown to occur in all the dimensions over a period of one year except in the dimension of anterior cranial height. It was concluded that skull growth does occur in male adults after the age generally accepted as that of maturity.
The extent of cardiac muscle in the great veins of the dog
Authors: Carrow Rexford , Calhoun M. Lois 
Published: February 2005

AbstractThe extent and arrangement of cardiac muscle in the great veins of adult dogs of both sexes was investigated. Cardiac muscle was found for varying distances in the venae cavae and pulmonary and azygos veins in all animals. The average distances which the muscle extended into these vessels in the beagles were: 1.88, 0.859, 0.525, and 0.622 cm. Similar measurements in the poodle were: 1.35, 0.705, 0.764, and 0.690 cm and in the shepherd: 3.05, 1.36, 1.22, and 0.926 cm. Both the venae cavae and pulmonary veins contained circular, spiral and longitudinal muscle bundles. The cardiac muscle was continuous from the superior venae cavae into the wall of the azygos vein and appeared to occupy the medial layer of the wall in all instances. Elastic and white fibrous connective tissue extended between the muscle bundles and appeared to invest the tapered muscle fibers in some places.
Double superior venae cavae with completely paired azygos veins
Authors: Nandy Kalidas , Blair Charles B. 
Published: February 2005

AbstractA case of double superior venae cavae with bilaterally symmetrical azygos veins is recorded for a 45 year old Caucasian male cadaver with no history of cardiovascular disorder. Death was reported as resulting from carcinoma of abominal viscera with extensive metastases.A review of the literature since 1887 indicates that this is an addition to 216 cases of double superior venae cavae and seven cases of double azygos veins previously reported in cadavers.A typical left brachiocephalic vein was absent. The anomalous vena cava, formed by union of left internal jugular and left subclavian veins behind the sternoclavicular joint, coursed vertically through the superior mediastinum, continued through the atrioventricular sulcus and opened into the right atrium near the orifice of the inferior vena cava. It was almost completely symmetrical with the right and received a complete azygos vein.The anomaly is explained as (a) failure of the precardinal anastomosis to form, (2) persistence of the entire left anterior and common cardinal veins and left horn of the sinus venosus, and (3) persistence of the proximal part of the left posterior cardinal which with the left supracardinal forms the left azygos vein. Morphological and clinical significances of the anomaly are discussed.
Cyclical changes in and significance of lipids and acid phosphatase activity in the seminiferous tubules of the rat testis
Authors: Niemi Mikko , Kormano Martti 
Published: February 2005

AbstractThe distribution of tubular lipids and acid phosphatase activity was studied in the rat testis and in the ductuli efferentes. The results were referred to the stage of the cycle of the seminiferous epithelium. The significance of the lipids and phosphatase of the ducts was tested in animals, where excretory ducts were separated from testis for 30 to 40 days.During the acrosome phase of the old generation of spermatids the lipids first made their appearance in the cytoplasm. During the subsequent stages of the cycle (II to VIII) both the amount of lipids and the intensity of the acid phosphatase activity gradually increased, reaching a maximum in the cytoplasmic “split‐offs” of the mature sperm at stage VIII. Most of the lipids, together with phosphatase‐positive cytoplasmic granules were discarded with the spermatozoa, but a small proportion underwent phagocytosis by the Sertoli cells. During stage IX both lipid‐ and phosphatase‐positive particles moved to the periphery of the tubules as their number in the basal cytoplasm of the Sertoli cells rapidly increased. Through the stages IX to II a gradually diminishing amount of lipids and acid phosphatase activity was seen forming a peripheral ring in the tubules. A temporary rise in the Sertoli cell phosphatase activity took place at the time when the nuclei of the maturing spermatids were deep in the seminiferous epithelium (stages IV and V).Lipid droplets associated with acid phosphatase activity were present in the epithelium of ductuli efferentes of intact rats. Ductectomy caused a complete disappearance of the epithelial lipids. Simultaneously, cysts filled with degenerating spermatozoa and abundant lipids formed on the cut surface of the testis. It is concluded that the main part of the residual cytoplasm of the spermatids forms an apocrine secretion which is presumably absorbed in the ductuli efferentes and in other parts of the excretory duct system.
Studies of the nerve growth factor in submandibular glands of female mice treated with testosterone
Authors: Goldstein Milton N. , Burdman José A. 
Published: February 2005

AbstractThe effect of testosterone propionate administration on the quantity and localization of a nerve growth protein was studied in the submandibular glands of adult female Swiss mice. Testosterone treatment for 14 to 24 days resulted in an increase in the quantity of a nerve growth‐promoting protein approaching those levels found in normal untreated adult male Swiss mice. The nerve growth‐promoting protein was localized by immunofluorescent techniques in the cytoplasm surrounding the zymogenic granules of the serous tubular portions of the submandibular glands in both control and treated animals. The role played by the submandibular gland in the synthesis or storage of this factor is discussed.
The Specificity of the hair papilla in the rat
Authors: Butcher Earl O. 
Published: February 2005

AbstractA flap of skin on the dorsum of Long‐Evans rats under anesthesia was turned back, the panniculus was excised and hair bulbs in the growing stage with the enclosed papillae were removed with scissors from a 0.5 cm square area. The flap was returned to its original position and the cut edges were sutured. Depapillated areas were biopsied at intervals following the operation, fixed in acetone and histologically prepared to study the distribution of alkaline phosphatase, glycogen changes, growth and differentiation.The hair recedes soon after the operation and is surrounded by the outer sheath cells, some of which remain below the receding hair as an epithelial strand. The latter begins growth and elongation 5–6 days after the operation. Differentiation follows and a fragile hair is formed, but the bulbs seldom have a papilla.The connective tissue in the subcutaneous area apparently cannot be stimulated or does not have the potentiality to become a papilla. Since only a fragile hair is produced by the depapillated follicle, the papilla is very important for the growth of the hair. These observations indicate that the papilla is endowed with special potentialities or has a specificity.
Evolutionary change in the primate wrist and inferior radio‐ulnar joints
Authors: Lewis O. J. 
Published: February 2005

AbstractThe joints at the junction of the forearm and hand are described in a number of Primates, including Man. It is shown that the original lower articular extremity of the ulna recedes from its primitive articulation with the triquetral and pisiform to become the ulnar styloid process, while a neomorphic ulnar head is elaborated entering into a new synovial inferior radio‐ulnar joint. The lower capsule of this joint becomes the triangular articular disk. In the anthropoid apes a meniscus (with a laterally‐directed concave free border bounding the ulnar styloid) develops in the interval between the receding ulna and the carpus. In gibbons this meniscus presents a lunula (os Daubentonii) which is also present in the human fetus as a transient cartilaginous nodule often erroneously homologized with the os intermedium. The upper articular surface of the human wrist joint is formed by the radius, the triangular articular disk and the homologue of the ape meniscus. Between the two latter components is an aperture, similar to that of apes, leading into a pea‐sized diverticulum of the wrist joint — the pre‐styloid recess. The mechanism of the evolution of new synovial joints is discussed.
The epithelial origin of the lymphocytes in the thymus of the embryonic hamster
Authors: Ackerman G. Adolph , Knouff Ralph A. 
Published: February 2005

AbstractDetailed cytological studies of serial sections have been performed on 85 golden hamster embryos ranging between 9 and 16 days (4–27 mm) of embryonic development.Sequential cytological changes in the development of the thymus of the hamster into an active lymphocytopoietic organ indicate that lymphoblasts develop by the gradual proliferation and transformation of “undifferentiated” epithelial cells comprising the primordial thymus. The “undifferentiated” epithelial cells undergo two distinct lines of differentiation during early development of the thymus: into lymphoblasts and into stellate reticular‐epithelial cells which form the organ parenchyma. Transformation, both of lymphoblasts and reticular‐epithelial cells begins during the eleventh day of development prior to the separation of the thymus and parathyroid.That the lymphoblastic and lymphocytic elements appearing in the embryonic thymus of the hamster are of epithelial rather than mesenchymal derivation is indicated by the following: (1) the absence of lymphocytes, lymphoblasts and hemopoietic activity in the connective tissue surrounding the embryonic thymus before and during the period of initial lymphoblastic formation; (2) the presence of a continuous basement membrane surrounding the developing thymus; (3) absence of cells passing through the basement membrane during this phase of development; (4) the absence of vascularity or vascular invasion of the thymus until after the appearance of lymphoblasts in the thymic parenchyma; (5) the demonstration of a sequential series of morphological transitions between “undifferentiated” epithelial cells and lymphoblasts and (6) the subsequent homoplastic proliferation and maturation of the lymphocytic elements from lymphoblasts in the developing thymus.
The relation between nerve fiber number and limb regenerative capacity in the lizard, Anolis
Authors: Zika Jocelyn , Singer Marcus 
Published: February 2005

AbstractThe present work provides some quantitative evidence for the view that the inability of the lizard's limb to regenerate is due to an insufficiency of nerve fibers. The number of fibers per unit area of the amputation surface of the lizard's forelimb is approximately one‐half that reported for the limb of the salamander, capable of regeneration. It is known that when the number of fibers in the salamander's limb is reduced to about half its normal value, regeneration does not occur in about 50% of the animals. The possibility is also discussed that the lizard's limb, in addition to being less innervated than that of the salamander, is also more refractory in its growth response to the nerve. Finally, the comparative poverty of innervation of the lizard's limb relative to that of the salamander suggests that the evolutionary trend in the vertebrate series toward elaboration of central nervous mechanisms was accompanied by a decline in richness of peripheral innervation.
An anomalous arrangement of the flexor musculature of the forearm and hand
Authors: Dahlgard Daryl L. , Kauth Gerald E. 
Published: February 2005

AbstractDuring a routine dissection, an anomalous arrangement of the flexor musculature of the hand was discovered. This bilateral anomaly included a deficient superficialis tendon to the index finger and the little finger and an absence of the fourth lumbrical muscles. The deficiency of the sueperficialis tendons to the index fingers was compensated for, however, by an anomalous muscle in each palm.The literature was searched both for related cases and for embryologic and phylogenetic background with which to explain the presence of this unusual combination of anomalies.
The fine structural localization and selective inhibition of nucleosidephosphatases in the rat adrenal cortex
Authors: Penney David P. , Barrnett Russell J. 
Published: February 2005

AbstractFine structural localization of enzymes hydrolyzing nucleoside phosphates in the rat adrenal cortex has been determined, and the selective inhibition of those enzymes exhibiting intracellular localization has been effected. Glutaraldehyde‐fixed adrenocortical tissue was incubated in a medium which contained a nucleoside mono‐, di‐ or triphosphate of adenosine, inosine, guanosine, or cytidine as substrate. Intracellular enzymatic activity was exhibited when one of three nucleoside phosphate substrates was employed. When IDP was used, final product of enzymatic activity was found on membranes of the endoplasmic reticulum, Golgi cisternae and intramitochondrial microvesicles. Final product was localized on the membranes of the endoplasmic reticulum and certain mitochondria when ITP was used. With GTP as substrate, activity was primarily localized on mitochondrial microvesicles and agranular endoplasmic reticulum, with no Golgi involvement noted.The phosphatases for which intracellular localization was determined exhibited four different sites of activity: (a) agranular endoplasmic reticulum, (b) microvesicles within mitochondria, (c) nuclear membrane, and (d) subendothelial and/or intercellular spaces with occasional involvement of the plasma membrane. When nicotinamide was added to the incubation media, intracellular phosphatase activity was inhibited. Extracellular enzymatic activity was unaffected by nicotinamide. The possible mode of action of nicotinamide in enhancing steroidogenesis and inhibiting intracellular phosphatase activity is discussed.
The hemo‐chorial mouse placenta
Authors: Kirby D. R. S. , Bradbury S. 
Published: February 2005

AbstractThe placental barrier of the mouse was examined by light and electron microscopy and found to be of the hemo‐chorial and not of the hemo‐endothelial type, as had been previously suggested. The suspected immunological function of the trophoblast is briefly reviewed, and attention drawn to the recent reclassification of the shrew placenta.