bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of the rat palate
Authors: Coleman R. D. 
Published: February 2005

AbstractNormal fetuses 13‐to‐21 days of age were obtained from female Long Evans Rats maintained on a stock diet known to produce normal offspring. Cleft palate fetuses were produced from mothers fed the same diet supplemented with 100 mg of pyrimethamine per kg of diet for four days beginning on the tenth day of gestation. The heads were studied with the low‐power microscope and serial histologic sections.In normal fetuses the lateral palatine processe appeared to form the roof of the mouth by two distinct mechanisms. Palatal closure was achieved rostrally by rotation of the lateral palatine processes from a ventromedial to a horizontal position while caudally, it resulted from the fusion of outgrowths from the medial surfaces. The original free ventral edges of the lateral palatine processes in the caudal region largely underwent regression by the seventeenth day. Closure commenced in the anterior third of the palate and proceeded rostrally and caudally.In the fetuses with cleft palate induced by pyrimethamine, the lateral palatine processes were observed in various stages of rotation or transformation depending on the region of the palate examined. The narrow width of these processes suggested that the antimetabolite had suppressed their growth at a critical stage in development. The results suggested certain similarities in the mechanisms of palatal closure in rat and man.
Cerebral intervascular strands of connective tissue as routes of transportation
Authors: Cammermeyer Jan 
Published: February 2005

AbstractIn the facial nucleus of the rabbit, fixed by a procedure of perfusion with delayed autopsy, intervascular strands of connective tissue contain on rare occasions either minute red PAS‐stained granules or clear vacuoles. With increasing age, the strands are transformed into homogeneous connective tissue bands.On the basis of these microscopic observations, it is inferred that, in younger animals, soluble and insoluble products can be channeled via the intervascular strands to adjacent blood vessels.
The Innervation of the joints of the wrist and hand
Authors: Gray D. J. , Gardner Ernest 
Published: February 2005

AbstractThe nerve supply of the joints of the wrist and hand was studied in dissections and in serial sections of fetal hands stained with silver.The radiocarpal joint was supplied mainly by branches of the anterior and posterior interosseous nerves.The inter‐carpal and mid‐carpal joints were supplied anteriorly by the anterior interosseous, median, and ulnar nerves, and by the deep branch of the ulnar nerve. Most of these joints were supplied posteriorly by the posterior interosseous nerve.Anteriorly the carpometacarpal joints were supplied by the ulnar nerve and its deep branch. Posteriorly they received fibers from the nerves running distally on the back of the hand. The deep branch of the ulnar nerve supplied all inter‐metacarpal joints.The metacarpophalangeal and interphalangeal joints were supplied mainly by the palmar digital nerves. The metacarpophalangeal joints also received fibers from the dorsal digital nerves and from the deep branch of the ulnar nerve. The interphalangeal joint of the thumb, the proximal interphalangeal joint of the index finger, and both interphalangeal joints of the little finger received fibers from the dorsal digital nerves.The articular branch of the superficial branch of the radial nerve, first described by Winckler, was distributed to some of the inter‐carpal and carpometacarpal joints on the lateral side of the wrist.
Electron microscopy of serial sections of the murine glomerular mesangium
Authors: Shimamura T. , Sorenson George D. 
Published: February 2005

AbstractAn electron microscopic study of serial and/or closely spaced step sections of the murine glomerular mesangium is reported. Photomicrographs were obtained from sections which extended through mesangial cells from one side to the other. These cells are separated from the capillary by matrix as well as overlying endothelial cells and from the epithelium by matrix and basement membrane.The observations clearly demonstrate the presence of a “third” type of cell within the murine mesangium which is separate and distinct from endothelium and epithelium.
Persistence of the axis artery of the lower limb
Authors: Blair Charles B. , Nandy Kalidas 
Published: February 2005

AbstractThree negro cadavers examined during routine dissection showed remnants of the axis artery acting as important adult arterial routes through the lower extremity. In two of the three cases, the anomalous condition involved persistent ischiatic portions of the axis artery continued into the genicular region as the popliteal artery. In these cases, the function of the much reduced femoral artery was assumed by an over‐developed profunda femoris artery which, with its perforating branches, then entered the persistent ischiatic artery to give rise to the popliteal.In one of these cases, the infragenicular circulatory pattern was completely typical.In two of the three cases, one of which is included above, the anomalous condition of the axis artery involved the infragenicular circulatory pattern. In these, two anomalous conditions were obvious: (1) the peroneal artery rather than the anterior tibial, which was incomplete distally, carried the blood supply to the dorsalis pedis artery, and (2) the peroneal artery, by virtue of its position relative to the tibialis posterior muscle, represented the old interosseous part of the axis artery distal to the ramus communicans medius rather than the more recently developed superficial peroneal artery.The sequence of embryonic development of the arterial supply of the lower extremity is presented along with comments as to the cause and time of origin of the anomalous conditions presented herein.
The skin of the mole (Scapanus townsendii)
Authors: Giacometti L. , Machida H. 
Published: February 2005

AbstractThe skin of the mole (Scapanus townsendii) has the following characteristic features. (1) The epidermis is thin over the general body surface and very thick on the palms and muzzle. On the snout the epidermis has the specialized end‐organs of Eimer. (2) The dermis has no papillary body, and few elastic fibers, except in the eyelids where elastic fibers are more numerous. The arterioles in the deep dermis are surrounded by nerve filaments which are positive for alkaline phosphatase. (3) In the hairy skin, the apocrine sweat glands are large and numerous, the ducts opening upon the surface and not inside the pilary canals. The secretory epithelium of the glands contains alkaline phosphatase, but no cholinesterase. (4) There are approximately 3,000 hairs per cm2, and each hair follicle is surrounded by an end‐organ which contains alkaline phosphatase. (5) The small and spherical sebaceous glands are similar to those of the rodents.
The preparation of injected and cleared “whole‐mounts” for the study of topographical anatomy
Authors: Hughes Trevor 
Published: February 2005

AbstractA simple method is described for the preparation of cleared and injected “whole‐mounts” of large masses of tissue (for example the mediastinal contents). This technique allows the use of high magnifications during examination and microphotography and the use of histological controls. It provides a novel method for detailed topographical studies because each tissue has its own distinctive vascular pattern which delineates it clearly.A direct three‐dimensional inspection has many advantages over the usual methods of dissection, or reconstruction from serial sections. This is particularly true of microcirculations, fine autonomic nerve patterns and the distribution of aberrant tissues (thyroid, parathyroid, etc.). Other distinctive features of tissues, such as positive chromaffin staining or the uptake of injected substance by the reticulo‐endothelial system, can also be demonstrated.The results obtained are demonstrated by photographs of “whole‐mounts” from dogs and adult and fetal cats. The advantages and disadvantages of the method are discussed.
Microanatomy and intramural physical forces within the coronary arteries (man)
Authors: Boucek Robert J. , Takeshita Ruth , Brady Al H. 
Published: February 2005

AbstractThe osita of the left and right coronary arteries differ as to location, the distribution of surrounding muscle bundles, and in the extension of aortic elements into the proximal segments of the vessels. The muscle of the media of the right coronary artery is composed of thick bundles describing a helical contour and arranged in repetitive segments. Multiple muscle bundles make up the media of the anterier descending and circumflex arteries, and each bundle arises separately from different quadrants of the adventitia. Contraction of the muscle bundles may generate intramural physical forces. Ostial regions, sites of nearly continual deformation from the pulse wave, develop focal physical forces. Accentuation of these physical forces may occur in certain regions and result in the alteration of the histology of the artery by depositing connective tissue elements.
Histological and ablation studies on the relation of the subcommissural organ and rostral midbrain to sodium and water metabolism
Authors: Brown Donald D. , Afifi Adel K. 
Published: February 2005

AbstractFourteen mature male rats were fed a sodium‐deficient diet for six weeks. After three weeks on the diet, electrical ablations were made in the region of the subcommissural organ. During the six‐week period measurements were made of water intake, urine output, and urinary sodium output. A second group of five one‐month‐old male rats was given the sodium‐deficient diet and seven litter‐mates a control diet. Five months later, the adrenals and subcommissural organs were studied histologically. The results obtained indicate that: (1) subcommissural organ ablation does not change urinary sodium excretion; (2) sodium deprivation, although producing significant changes in the width of the adrenal zona glomerulosa, does not affect the periodic acid‐Schiff reactive material in the subcommissural organ; (3) complete subcommissural organ ablation is associated with decreased urine output and water intake; (4) partial subcommissural organ ablation combined with destruction of structures in and around the rostral periaqueductal gray matter and adjacent diencephalon is associated with increased urine output and water intake; (5) lesions which failed to involve significantly the aforementioned areas are associated with no change in urine output or water intake.
Correlation of retinal cytoarchitecture and ultrastructure in Golgi preparations
Authors: Stell William K. 
Published: February 2005

AbstractA simple procedure is described for obtaining both cytoarchitectural and ultrastructural information about nervous tissue. Freshly excised fish retinas were impregnated by a modification of Cajal's rapid Golgi procedure, embedded in Epon, sectioned at 80 μ, and scanned by light microscopy. Isolated well‐impregnated cells were selected for further study and remounted for ultrathin sectioning. The appearance of 80‐μ, 1‐μ, and ultrathin sections was correlated.The material responsible for Golgi impregnation is a water‐soluble, electron‐dense precipitate which usually fills the cytoplasmic ground substance but does not penetrate the plasma membrane or membrane‐bound organelles. Preservation of ultrastructure of spared organelles permits identification of cells. Since the precipitate does not encrust the outer surface but is contained within the plasma membrane, it does not obscure fine‐structural relationships between cells. The method has demonstrated the complex relations of horizontal and bipolar cell processes to the receptor synaptic terminals.While less comprehensive than three‐dimensional reconstruction from serial ultrathin sections, this method is much simpler, and is useful for surveying larger amounts of tissue. It may be particularly advantageous for investigating ultrastructural relationships of cell processes which are so long as to prohibit such reconstruction.
Livers of choline‐deficient pregnant and fetal rats
Authors: Meader Roland D. 
Published: February 2005

AbstractA group of 30 pregnant rats was subdivided into three experimental groups of ten animals each. The first and second received choline‐deficient and choline‐supplemented diets respectively during the usual 21 days of gestation. The third was fed a choline‐deficient diet an additional 30 days prior to insemination, and subsequently during the usual period of gestation.Groups of ten non‐pregnant animals received the choline‐deficient and choline‐supplemented diets respectively for 21 days, a period comparable to that of gestation.Choline supplementation of the basal (choline‐deficient) diet resulted in a complete absence of stainable lipid in the livers of pregnant and fetal rats.The stress effects of pregnancy on increased susceptibility to choline deficiency were assessed by comparing the amount of stainable fat (in frozen sections) in the livers of pregnant rats maintained on the choline‐deficient diets during the period of gestation with that in livers of non‐pregnant rats fed the deficient diet for the same length of time.Under the conditions of this experiment, the stress effects of pregnancy increased susceptibility to choline deficiency, as evidenced by the increased accumulation of fat in both maternal and fetal livers.
Histological comparison of the thymus of germfree (axenic) and conventional CFW mice
Authors: Bealmear M. , Wilson R. 
Published: February 2005

AbstractThe histology of the thymus of both germfree and conventional mice at days 0, 14, 50, and 168 supports the interpretation of the growth pattern of the thymus as a reflection of the lymphocyte population of the cortex and medulla. In general the conventional thymus has more small lymphocytes in the cortex and more lymphocytes migrating into the medulla than in its germfree counterpart. Hence it would seem that antigenic challenge stimulates lymphocyte production in the thymus cortex and initiates a chain of events that may eventually result in thymus lymphocytes populating the other lymphoid tissues of the body, or that may result in lymphocyte degeneration in the thymus and the subsequent releas of a humoral factor that may stimulate the other lymphoid tissue to lymphocytopoiesis.
Development of the human renal glomerulus I. Differentiation of the filtering membrane
Authors: Aoki Agustin 
Published: February 2005

AbstractThe development of the human renal glomerulus, in particular its filtering membrane, has been studied by light microscopy with a high resolution technique as a necessary and complementary step for electron microscopical studies.The glomerular filtering membrane is a triple layered structure composed of the visceral epithelium, the capillary endothelium and a basement membrane interposed between them. These three layers have different and definite origins in the metanephrogenic blastema, but close interdependency during the developmental process exists. Mesenchymal cells were demonstrated migrating from the renal interstitium into the invaginating wall of the renal vesicle and transforming into the endothelial and mesangial cells. The visceral epithelium originates from the invaginated wall of the primitive renal vesicle and is transformed from a mass of cells into a special membrane concomitant with the differentiation of the capillary loops. The basement membrane is produced later by the close association of the other two cellular layers.
The cranial attachment of the sphenomandibular (tympanomandibular)ligament
Authors: Burch James G. 
Published: February 2005

AbstractThe sphenomandibular (tympanomandibular) ligament develops from Meckel's cartilage between the future petrotympanic fissure and the mandibular lingula. The superior attachment of this ligament has been described to attach to the sphenoidal spine.Fifty‐one cadaver half heads were dissected to study the superior attachment of this ligament. Forty‐five of the 51 ligaments were found to be attached in the area of the petrotympanic fissure, not directly to the sphenoidal spine. Six of the specimens had a thin fibrous slip which fanned out medially to the sphenoidal spine.Twelve additional cadaver specimens were decalcified and cut in various planes through the temporomandibular joint. All specimens showed a fibrous continuation of the ligament through the petrotympanic and/or squamotympanic fissures with an attachment to the malleus in the middle ear. When tension was applied to the ligament the malleus was seen to move.A 115 mm human fetus head was dissected. A ligamentous structure was seen to run from the medial side of the mandibular ramus to the future squamotympanic fissure area. When observed microscopically the ligament was continuous through the fissure and attached to the malleus.
An intercellular substance in rat cerebral cortex: Submicroscopic distribution of ruthenium red
Authors: Bondareff William 
Published: February 2005

AbstractSpecimens of rat cerebral cortex were fixed in solutions containing ruthenium red and prepared for electron microscopy by a method described by Luft ('65a). In specimens taken from a narrow zone 5–10 m̈ thick and about 5 m̈ beneath the pial surface the ruthenium red reaction was found to be uniform and reproducible. In this zone a particulate reaction product was distributed extracellularly. The reaction product accumulated in intercellular gaps, filling them with closely‐packed, dense particulates which adhered closely to the outer leaflets of apposed plasma membranes and filled also the intercellular spaces with additional particulates.The selective, extracellular distribution of the ruthenium red reaction product suggested the presence of an intercellular acid mucopolysaccharide, which may be different in capillary basal laminae, intercellular gaps and synaptic clefts, as suggested by the variable reactivity of these extracellular sites.The presence of an intercellular acid mucopolysaccharide in the cerebral cortex would controvert neither ion transport by glial cytoplasm nor intercellular channels. It is suggested that such an intercellular substance might facilitate ion transport and the histophysiological significance of this is discussed.
The fine structure of the ductuli efferentes of the opossum
Authors: Ladman Aaron J. 
Published: February 2005

AbstractThe fine structure of the straight portions of the ductuli efferentes of the opossum were studied by light and electron microscopy. Two cell types, a ciliated and non‐ciliated cell, characterize the simple columnar epithelium that lines the ductuli. The non‐ciliated cell possesses an extraneous coating of the luminal plasma‐lemma, aggregations of apical canaliculi, and vacuoles of varying density distributed in the supranuclear cytoplasm. Such morphological criteria have been regarded as suggestive evidence for absorptive function. The epithelium rests upon a thick basement membrane beneath which are variable amounts of smooth muscle and connective tissue elements.Observations of the structure of the simple squamous epithelium lining the processus vaginalis are reported.Myelinated and unmyelinated nerves are found in the adnexa of the ductuli. These are enclosed in a thin, cellular investment, the innermost layer of which is usually incomplete. This cellular wrapper is considered a “perineural epithelium” but its characteristics are at variance with those found in the recent literature.
Cell architecture in the papillary layer of rat incisor enamel organ at the stage of enamel maturation
Authors: Kallenbach Ernst 
Published: February 2005

AbstractShape and arrangement of cells and extent of intercellular spaces were studied in sections of enamel organ cut in three planes: at right angles to the axis of the incisor tooth, at right angles to the axis of the ameloblasts, and parallel to the axes of the incisor and ameloblasts.The cells in contact with the base of the ameloblasts make up the proximal part of the papillary layer. They have a polygonal cross section close to the ameloblasts and point several sheet‐like cell processes towards the blood vessels which invaginate in the papillary layer. Intercellular spaces of constant width pervade the proximal part and provide a direct and straight communication between blood vessels and ameloblasts.The cells of the ridges make up the distal part of the papillary layer, and are flattened in the direction of the ridges. Intercellular spaces in the ridges are narrower than in the proximal part and visible with the light microscope only during a fraction of the enamel maturation period.No distinct cell layers are visible within the papillary layer during enamel maturation. All cells in the papillary layer may be in contact with the basement membrane investing the enamel organ. The structure of the papillary layer changes with the different phases of enamel maturation. Functional aspects of the papillary layer are briefly discussed.
Congenital malformations in nonhuman primates: Spontaneous and experimentally induced
Authors: Wilson James G. , Gavan James A. 
Published: February 2005

AbstractAn attempt to survey spontaneous teratogeny among nonhuman primates bred under laboratory conditions revealed interesting but nonconclusive results. Data on controlled breeding in 2950 animals representing 12 species yielded an estimated incidence of 0.44% malformations. No indication was found that other primates display more malformations than man, and the limited information available suggests that there may be fewer spontaneous defects in nonhuman forms.Macaques and baboons appear to respond in a similar manner and to the same types of extrinsic agents as does man. Thalidomide, Rubella virus and androgenic hormones produce similar defects in comparable dosage at equivalent stages in development in both groups. Several other agents thought not to be teratogenic in man have been realistically tested in primates and also found to be non‐teratogenic.Using thalidomide an attempt was made to determine the degree of sensitivity and delimit the susceptible period of Macaca mulatta to this drug. Typical limb malformations were obtained with a single dose of as little as 16 mg/kg between the twenty‐fifth and thirtieth days of gestation. Comparable doses at earlier and later ages were without effect, thus defining the susceptible period. In addition, evidence of a positive dose‐response relation and of a cephalocaudal gradient in teratogenesis was obtained.
The premaxilla: Embryological evidence that it does not exist in man
Authors: Wood Norman K. , Wragg Laurence E. , Stuteville Orion H. 
Published: February 2005

AbstractMany accounts of the human premaxilla describe its ossification centers and time of fusion with the maxilla, but that such a bone even exists in the human has long been questioned. Very few specimens undergoing initial phases of ossification have been reported and no convincing photographs of separate centers have been published.This report is based on 90 serially sectioned human embryos whose ages (Streeter's Horizons XVIII to XXIII) were closely grouped around the age when ossification of the upper jaw begins. There is but one ossification center bilaterally which, although it appears first in the cuspid region, rapidly involves an area extending from the molar to the central incisor region.Not one of the specimens showed an independent center for the “premaxilla” nor an “incisive suture” in the area of ossification. The premaxilla does not exist as an independent bone in man.