bluuebunny/crossref_metadata_2025 huggingface dataset:
The effects of grafting during various stages of the hair growth cycle
Authors: Sanford Barbara H. , Chase Herman B. , Carroll Sarah B. , Arsenault Claudette T.
Published: February 2005

Gross and microscopic observations of graft and surrounding area were made after grafting during various stages of the hair growth cycle.

All grafts were successful although temporary disturbance was observed when grafting was done during late anagen.

Biopsies showed epidermal breakdown, even in telogen grafts, with repair being accomplished primarily by diversion of hair follicles to epidermal production. The later in anagen a graft was done, the less likely the follicles were to return to hair production later.

Permanent loss of pigment was seen in some grafts, particularly those done in late anagen. Loss of pigment cells or their attachments from scraping the graft undersurface is a possible explanation, as is loss or damage to melanocytes while the follicles are producing epidermis.

Delays and irregularities in hair growth cycles were also observed in host skin surrounding grafts. An explanation involving loss of inhibitor during grafting is proposed.

The authors feel that hair growth activity in either donor or host is not an adequate explanation for graft rejection. It is also emphasized that hair growth is a poor criterion for graft survival.
Postnatal development of beta cells and ILA secretion in the pancreatic islets of the golden hamster
Authors: Sak Matthew F. , Macchi I. A. , Beaser Samuel B.
Published: February 2005

Fetal and neonatal endocrine pancreas of the golden hamster (Mesocricetus auratus) was evaluated cytochemically with regard to maturation of beta cell granulation (aldehyde fuchsin technique) and the structural findings were related to the release of insulin‐like activity (ILA) in vitro (rat epididymal fat pad bioassay).

In the fetal pancreas 12 hours before birth, beta cells could not be distinguished histochemically although considerable ILA was released. In the absence of distinct islands of Langerhans at birth, a few cells showed AF+ granulation which was accompanied by a slight increase in the ILA. Maximal release of ILA occurred approximately on the second postnatal day when the AF+ granulation was denser and more abundant than at earlier periods. Beyond the second day, the rate of in vitro ILA secretion decreased although islets and beta cells showed progressive structural maturation. There was also a relative increase in the amount of exocrine tissue in the portions of pancreas used for bioassay. Advancing proteolytic inactivation may have accounted for the decrease in effective ILA when the latter was expressed per unit weight of tissue.

The data indicate that in the golden hamster, beta cells are biochemically competent before they demonstrate cytochemical maturity.
The skin of primates XIX. The relationship between melanocytes and alkaline phosphatase‐positive cells in the potto (Perodicticus potto)
Authors: Kechijian Paul
Published: February 2005

The epidermis of the potto, which normally contains no DOPA‐reactive melanotic melanocytes, supports a population of large dendritic cells which are specifically reactive for alkaline phosphatase. After irradiation of the skin with ultraviolet light, these same dendritic cells become DOPA positive and produce visible melanin. These results give further evidence that the alkaline phosphatase‐reactive dendritic cells are part of a unique system of epidermal melanocytes.
Innervation and regeneration in orbitally transplanted limbs of Amblystoma larvae
Authors: Pietsch Paul , Webber Richard H.
Published: February 2005

There is a widespread belief that innervation is an indispensible requirement for regeneration in salamander limbs. Several independent investigations have indicated that this view is too rigid. In this laboratory it was observed that regeneration proceeds in orbitally transplanted limbs, but the signs of innervation are few when the tissues are stained with ordinary histological procedures. The present study was conducted to find out if orbitally transplanted limbs do, in fact, possess nerve fibers and if their presence is, indeed, required for regeneration to proceed.

Forelimbs of Amblystoma larvae were transplanted to the orbit. In one series, transplants were amputated two weeks after transplantation. Amputated segments were stained with protargol and revealed very few signs of innervation. Nevertheless, regeneration proceeded and reached a typical outcome within the usual time required for completion of the process normally. Full‐term transplant regenerates exhibited innervation at levels of about one‐third of normal values.

In another series of experiments, limbs were subjected to distal amputation either before or shortly after transplantation. Regeneration proceeded normally in these experiments providing that the transplant was rapidly vascularized. When vascularization was delayed or failed, regeneration was retarded or did not occur at all.

These findings, taken in light of those of other works, suggest that the function of nerves under ordinary conditions may be assumed by other tissues under circumstances produced by transplantation. This in turn suggests that nerves influence regeneration in a generalized manner and that the specificity ordinarily associated with them may be quantitative rather than qualitative in nature.
A study of the inguinal region of the abdominal wall in female mice
Authors: Leppi T. John
Published: February 2005

Bilateral inguinal sacs or outpouchings of the abdominal wall normally occur in Brown‐belt stock female mice. The length of each sac was determined to be from the caudal border of the pubic symphysis or interpubic ligament to the caudalmost extension of the sac. Sacs of control animals usually exceeded 1.0 mm in length and were longer in intact and ovariectomized mice treated with implanted testosterone pellets. There were no viscera observed in any of the inguinal sacs of the mice in this study. The bilateral inguinal sacs appear to be homologues of the scrota of males. The alterations in sac length produced by testosterone treatment are believed to be the result of changes in the connective tissue components of the sac.
General sensory innervation of the human tongue
Authors: Marlow Clyde D. , Winkelmann R. K. , Gibilisco Joseph A.
Published: February 2005

Specimens (obtained during oral and pharyngeal operations) from various regions of 33 normal human tongues were studied by silver staining and cholinesterase technics. The tongue was found to be innervated by three types of endings: nonmyelinated free endings, semiorganized coiled endings, and organized endings. All organized endings are mucocutaneous end organs in various sizes and shapes and are nonspecific‐cholinesterase positive.

Correlation of new information with pertinent clinical and pathologic observations indicates that biopsy by refined histochemical methods might be useful in diagnosis in cases of tongue neuropathy such as glossodynia and glossopyrosis.
Dissection of the orbit
Authors: Laurenson R. D.
Published: February 2005

This paper reports that extensive removal of bone from the superior and lateral aspects of the orbit is easy with the aid of an autopsy saw. When this is done and the lateral rectus muscle cut an excellent exposure of the orbital contents is gained.
Demineralization with EDTA by constant replacement
Authors: Bélanger Leonard F. , Copp D. Harold , Morton Margaret A.
Published: February 2005

An apparatus for demineralization of hard tissues by constant replacement of a saturated solution of EDTA is described. This method allows for more rapid demineralization through better Ca chelation. EDTA demineralization preserves cells and matrix constituents particularly the mucopolysaccharides as demonstrated by staining, Alpharadiography, phase contrast microscopy and microincineration. Cold acetone fixation followed by cold EDTA demineralization retains several enzymic activities.
The distribution of the autofluorescent cells and of the yellow autofluorescent granules in the rat tissues
Authors: Sainte‐Marie Guy
Published: February 2005

We previously described in the rat lymphocytic tissues peculiar cells referred to as autofluorescent cells. They are filled with cytoplasmic granules most of which emit a yellow autofluorescence under the fluorescence microscope. In this work, in an attempt to clarify the function of these cells, their distribution was investigated in the various tissues of the rat. Cells comparable to the autofluorescent cells were found in the stroma of the trachea, gut, ovaries, uterus and bone marrow. These areas are sites of antigenic challenges and have a high mitotic activity. Hence, their distribution can support our previous suggestions that these cells are involved in immunity or growth. The tissues were examined furthermore to see if their parenchymal cells would contain yellow autofluorescent granules. The cells of most tissues were found to have some granules. It is suggested that these granules represent organelles, or lipids associated with organelles involved in cellular work.
Sex chromatin and idiograms from rats exhibiting anomalies of the reproductive organs
Authors: Allison John E. , Stanley Allan J. , Gumbreck Laurence G.
Published: February 2005

Certain anomalous conditions associated with the reproductive organs have arisen in a line of King‐Holtzmann hybrid rats maintained in our laboratory. These are sterile pseudohermaphroditic males in which the entire reproductive tract except the testes is missing; apparent males demonstrating an ectopic inguinal ring and testis on one or both sides; and sterile males with descended scrotal testes. The procedure developed by Moore ('55) for staining sex chromatin was applied to cells from liver, spinal cord, testis, and parotid gland of rats. A sex difference is clearly shown, however, only with the liver cells. Ford and Woollam's ('64) sequence for demonstrating mammalian chromosomes renders positive results on bone marrow cells. This method applied to liver and testis yields unsatisfactory results.

Examination of idiograms and sex chromatin bodies from animals exhibiting the conditions outlined above leads to the following conclusions: (1) all abnormal animals studied are genetic males; and (2) the pseudohermaphrodites, though genetically male, exhibit a pattern of differentiation of chromosomes during the metaphase plate stage resembling that in the female.

Similarities between certain anatomic and physiologic factors exhibited in pseudohermaphroditic rats and those present in “testicular feminization” in man are discussed. Male rats exhibiting an ectopic inguinal ring and testis and sterile males with descended scrotal testes also may have their counterpart in man.
The right ovary of the chick embryo after early sinistral castration
Authors: Groenendijk‐Huijbers Margot M.
Published: February 2005

After sinistral ovariectomy of young chicks the right ovary develops into a testicular structure. This well known fact induced the author to study the development of the right ovary of chick embryos after early sinistral castration. In four‐day‐old embryos of various breeds and strains the left gonadal primordium was destroyed by local electro‐diathermic coagulation. The remaining right ovaries, developing until autopsy at 12‐ to 19‐days of incubation, as a rule showed a compensatory growth as well as a marked lacunarization of the medullary layer adjacent to the surface epithelium. The enlargement, verified by means of volumetric, planimetric and ocular micrometer measurements, was statistically significant from the fourteenth day onwards. The compensatory growth particularly concerned the ordinary medullary cord cells and the fat laden cells. The latter cells kept their lipid globules and their characteristics remained unchanged. No indications of masculinization were seen apart from a significant reduction of the incidence of cortical rudiments. As a whole the right ovary preserved its characteristic structure. Arguments are brought forward to substantiate the concept that hyperfunction of the pituitary gland of the hemicastrate is responsible for the modifications observed.
The lymphatic system of Bradypus tridactylus
Authors: Azzali Giacomo , Didio Liberato J. A.
Published: February 2005

The lymphatic system of the sloth (Bradypus tridactylus) was described after the study of five specimens captured in Brazil. The lymphatic system was injected with Prussian blue suspension and neoprene latex (the latter followed by partial corrosion). The description includes lymph nodes, lymphatic networks, vessels and trunks. The distribution of these structures follows the general pattern of other Xenarthra, namely, Dasypus, Euphractus and Tamandua. However, the following peculiarities were noted: the submandibular, popliteal and posterior mediastinal ll.nn., the abdominothoracic subcutaneous lymphatic collecting vessels, the true principal lymphatic trunks, the cisterna chyli, and the thoracic duct were missing in Bradypus tridactylus. The mesenteric ll.nn. do not fuse and their efferent vessels intermingle with those originating from the cecocolic ll.nn. forming a mesenteric lymphatic plexus. The lymphatic vessels arising from the submucous network of the descending and sigmoid colon are arranged as parallel lamellae similar to those in Dasypus. The efferent collecting vessels from several abdominal organs ultimately empty directly in the inferior vena cava and its trunks of origin and those coming from the bronchial ll.nn. lead to the azygos vein. This feature reminds one of the conditions described in some monkeys. The mesenteric postlymphonodal plexus is well developed and because of the absence of intercalated lymph nodes in the labrinthine circulation it resembles that of amphibia and birds.
Lack of effect of relaxin or steroids on the histology of the mouse parathyroid gland
Authors: Manning J. P. , Steinetz B. G. , Priester Sara F. , Butler Margaret C.
Published: February 2005

Normal parathyroid glands exhibited two distinct cellular types: one type of cell had a large round nucleus containing fine chromatin granules and a nucleolus; the other type had a round or spindle‐shaped nucleus with densely‐packed chromatin. The following hormonal preparations were tested and failed to alter parathyroid histology: relaxin extract (R), estradiol cyclopentylpropionate (ECP), combined ECP and R, or various combinations of these hormones with progesterone or cortisone acetate. The pubic joints of the mice underwent the anticipated hormonally‐induced changes. Our results are at variance with those of Chase and Shanmugasundaram ('64) who (a) described only one cell type in the mouse parathyroid and (b) reported that relaxin alone or a combination of estrogen and relaxin induced cellular changes suggestive of increased glandular function. The two studies are apparently irreconcilable; however, we did note in about 30% of our mice variable lymphatic aggregates in the thyro‐parathyroid complex. Although not actually related to hormonal treatments, it is conceivable that in a small series of animals and without serial sectioning, such lymphatic tissue might be mistaken for altered parathyroid gland.
Cellular changes, protein and glycogen content in developing rabbit corpora lutea
Authors: Rennie P. , Davenport G. R. , Welborn W.
Published: February 2005

The glycogen, protein and absolute cell numbers of the developing rabbit corpus luteum were measured from 24 hours to 192 hours after mating. There was no significant alteration in the protein content, which was approximately 9%. The glycogen content increased significantly from 0.14% at 24 hours to 0.26% at 120 hours and subsequently remained constant. The cell numbers were determined by homogenizing the tissue and the nuclei were counted in a Neubauer hemocytometer. The total cell numbers increased from 10 × 104, of which 65% (6.3 × 104) were luteal cells, to 67 × 104 where 21% (9.8 × 104) were luteal cells. It was not determined whether the increase in luteal cells was due to mitotic division or transformation of the other cell types into luteal cells.
A histochemical and biochemical study of phosphorylase and glycogen synthetase in smooth muscle
Authors: Bo Walter J. , Smith Mavis S.
Published: February 2005

Phosphorylase and UDPG‐glycogen synthetase were studied in the smooth muscle of the urinary bladder, large intestine, skeletal muscle (adductors of thigh), and esophagus of the adult male and female rat. The two enzymes were investigated by histochemical and biochemical procedures.

In the skeletal muscle of the thigh and esophagus, UDPG‐glycogen synthetase was not as strong as phosphorylase. The latter enzyme was strong in the smooth muscle cells of the urinary bladder and large intestine. The response was better in the inner circular than in the outer longitudinal layer of the large intestine. Only phosphorylase was detected in the muscularis mucosa of the esophagus and large intestine. UPDG‐glycogen synthetase activity varied from a good response to a very weak one in the smooth muscle cells of the urinary bladder and large intestine. In the latter organ the response was stronger in the inner circular than in the outer longitudinal layer. From the biochemical studies phosphorylase and UDPG‐glycogen synthetase were determined to be present in significant amounts in the urinary bladder, large intestine, and skeletal muscle of the thigh.

Since significant amounts of the enzymes are present in smooth muscle, glycogen may be synthesized from UPDG by the action of UDPG‐glycogen synthetase, while phosphorylase is concerned with the breakdown of glycogen to G‐1‐P. However, more information on the relationship of the enzyme to glycogen concentration in smooth muscle is needed.
The blood supply of the rat mandible
Authors: Huelke Donald F. , Castelli Walter A.
Published: February 2005

The blood supply of the rat mandible was studied in 12 adult animals using four techniques. Eight animals were injected with a cinnabar, mercury, zinc oxide mixture (Teichmann's paste) for dissection and for cleared specimens, two with radiopaque material, and two others with India ink. Findings indicate that the coronoid, condylar, and angular processes of the mandible are supplied by vessels which are primarily concerned with the nutrition of the muscles that attach to these areas, and not from the inferior alveolar artery. The inferior alveolar artery supplies the body of the mandible, teeth and adjacent structures. After entering the mandibular foramen this artery bifurcates beneath the third molar tooth. The larger inferior stem passes downward and backward to supply multiple branches to the pulp of incisor tooth and branches to the periodontium about this tooth. The superior stem passes forward beneath the apices of the molar teeth to supply them and the adjacent tissue. The venous drainage of the bone varies – the coronoid and condylar processes drain downward into a confluence of venous channels about the apex of the incisor tooth. Veins of the molar teeth and supporting structures pass through the bone into gingival veins. Concentrations of venous channels primarily draining the angle and condyle are found along the inferior border of the angle and above, where the angular process joins the body proper.
Number and distribution of thyrotropic cells in the mouse pituitary gland
Authors: Messier B.
Published: February 2005

The pituitary gland of a normal LAF1 mouse was reconstructed from serial coronal sections. Alcian blue positive cells (thyrotropes) were found in greater abundance in the mid portion of the gland. Pooled cell counts from every tenth section yielded an overall frequency of 0.43% alcian blue positive cells.

The average frequency of these cells was also assessed in a group of eight normal mice. Cell counts in random coronal sections from the mid portion of each pituitary revealed a mean percentage of 0.87 alcian blue positive cells.
Daily leukocyte rhythms in normal and hypophysectomized rats exposed to different environmental light‐dark schedules
Authors: Pauly John Edward , Scheving Lawrence Einar
Published: February 2005

With environmental factors rigidly standardized, Sprague‐Dawley rats were maintained under the following lighting schedules: (1) artificial light 0600 to 1800 alternating with 12 hours of darkness‐LD, (2) reversal of the above‐DL, (3) constant darkness‐DD, and (4) constant illumination‐LL.

During each regimen, both total and differential white blood counts of tail blood were done in a hemocytometer and then were compared to differential counts done by the smear technique on groups of 16 animals at bi‐hourly intervals over a 24‐hour period. Rhythms in lymphocytes, eosinophils and neutrophils were found under all lighting conditions by plotting the bi‐hourly mean values of the absolute counts along the 24‐hour time scale; rhythms were not found when the means of the differential counts were plotted. The DL rhythms always were the reverse of the ones seen in LD.

In LD, DL, and DD, but not in LL, the rhythms of the three cell types were synchronized, that is, their peaks and troughs occur at about the same time each day.

Some evidence, based on desynchronization from LD rhythms, suggests that all three cells types in DD and the lymphoctyes in LL were or had been at one time free‐running.

Expressed as an overall increase in magnitude, the greatest response in the three cell types to abnormal lighting conditions (DL, DD, and LL) was seen in the neutrophils.

Similar determinations made on a second colony of hypophysectomized animals maintained under LD conditions demonstrated that hypophysectomy did not abolish the rhythm characteristic of lymphocytes, since the timing was identical to the rhythm seen in normal LD animals. There was, however, a lymphocytosis in the hypophysectomized group. Hypophysectomy greatly modified, but did not abolish the eosinophil and neutrophil rhythms.

The significance of periodicity analysis in relation to bioassay is discussed.
A method of constructing plastic display jars
Authors: Audette L. G.
Published: February 2005

A simple and inexpensive method of fabricating transparent plastic, large capacity, rectangular display jars for preserved wet specimens is described. Simple tools are used, including a holder for a tape‐type heating element and a bending jig which are easily fashioned from available material. The jars are permanent, moisture tight, and provide quality and uniformity at low cost.
Change in the distribution of succinic dehydrogenase within the rat hepatic lobule after ligation of the common bile duct
Authors: Cohen P. J.
Published: February 2005

The distribution of hepatic succinic dehydrogenase has been compared in common bile duct‐ligated and control rats. In control cases, a gradient of succinic dehydrogenase activity is found within each liver lobule; periportal regions exhibit the highest level of enzyme activity, and the activity gradually decreases in a central direction. Centrilobular regions exhibit only slight activity.

However, after complete ligation of the common bile duct, this gradient gradually disappears from the lobule due to a gradual increase in succinic dehydrogenase activity in middle and central regions. By 18–19 days after ligation, a relatively high and uniform level of succinic dehydrogenase activity is displayed by all surviving parenchymal cells, regardless of position occupied within the lobule. The possible functional implications of this finding are discussed.
Correlation of localization of alkaline and acid phosphatases with morphological development of the rat kidney
Authors: Desalu A. B. O.
Published: February 2005

The Gomori (metal‐salt) and azo‐dye techniques were used for the localization of alkaline and acid phosphatases in the metanephric kidneys from 13‐ to 22‐day‐old fetal rats. Alkaline phosphatase activity was localized first in the luminal (brush) border of the differentiated proximal tubule in the kidneys of 19‐day‐old fetuses. Acid phosphatase activity was first localized in the cytoplasm of all the morphologically differentiated cells of the nephron in the kidneys of 20‐day‐old fetuses as cytoplasmic “droplets.” The relationships of the localization of these to the morphological differentiation of the nephron is discussed.
Rotational movements in the foot of Galago senegalensis
Authors: Hall‐Craggs E. C. B.
Published: February 2005

The wide range of rotational movement found in the elongated foot of Galago senegalensis cannot be accounted for by movement at the subtalar joint. A gross and microscopic study of the intertarsal joints of this animal have revealed a discrete calcaneonavicular articulation between the shafts of these bones together with a pivot joint at the calcaneocuboid articulation. It is suggested that little movement occurs at the subtalar joint and that most of the rotation found is produced by a movement of the navicular and distal tarsal bones about an axis which passes through the attachment of the plantar calcaneonavicular ligament to the calcaneus, the calcaneal portion of the calcaneonavicular joint and the pivot of the calcaneocuboid joint. A comparison is made with the foot of Tarsius and with the rotational movements of the forearm.
The peritoneum ofTrichosurus vulpecula
Authors: Perrott J. W.
Published: February 2005

This investigation of the peritoneal reflections of the brush‐tailed possum was carried out on eight adult specimens. The greater omentum is relatively short, whereas the lesser omentum is arranged much the same as in man. Only the mesoduodenum and the distal mesocolon are totally reflected from off the dorsal peritoneum. The remaining peritoneal folds are either free or have a weak scanty attachment to the dorsal wall thus ensuring the general mobility of the gut in an animal whose posture is both orthograde and pronograde. These reflections are discussed from a phylogenetic aspect.
Pathological changes in adipose tissue of obese mice
Authors: Hausberger Franz X.
Published: February 2005

Gonadal and perirenal fat pads from markedly obese mice show pathological changes associated with the appearance of many large macrophages, small mononuclear cells resembling lymphocytes, and polymorphonuclear cells. The first recognizable changes are always associated with necrosis of the fat cell membrane. Advanced stages also show reduction of the number of fat cells, formation of large fat vacuoles and cysts, and predominance of innumerable pathological cells. The extent of tissue changes varies considerably even within one fat pad but is dependent on the degree and duration of obesity. Animals weighing less than 45 gm are only occasionally, heavier mice almost regularly, affected. The nitrogen content of normally healthy adipose tissue decreases as the animals grow older and fatter, while fat pads exhibiting tissue pathology show the expected increase in the protein and water content, and a reduction of the lipid content. The pathological changes were observed in obese‐hyperglycemic mice, in several strains of mice made obese by the administration of goldthioglucose, and in four old and very fat controls. These four controls were the only ones in several hundred normal mice examined which showed changes. Few and only minor pathological changes were noted in subcutaneous fatty tissue of mice which showed marked pathology of the abdominal fat pads.
The mitotic pattern in the neural tube of Ambystoma maculatum
Authors: McKeehan Morris S.
Published: February 2005

In stages H18–H22 the neural tube was composed of a partially stratified epithelium, reflecting its origin from epidermal and sensory layers of ectoderm. Mitotic figures were distributed over the whole neural wall. Fifty‐four to 91% were peripheral to the luminal zone. There was no evidence of nuclear migration attending mitosis. After integration of epidermal and sensory cells into a single epithelium by stage H24, mitotic figures were mostly near the lumen and for some time prophase stages were distributed peripherally. During this period nuclear migration to and from the lumen accompanied mitosis as in higher vertebrates. By stage H46 nuclei of the neural epithelium were restricted to a narrow zone near the lumen. Most mitotic figures and all other phases of mitosis were in this zone. There was a consequent lack of appreciable nuclear migration. A few peripheral mitotic figures remained in neural cells through stage H46. Some were in epithelial cells whose nuclei did not migrate to the lumen. Others were in the mantle zone, perhaps in neuroblasts. These observations support the view that the neural epithelium, whatever its extent, is germinal. Neither a “germinal zone” nor a special strain of “germinal cells” could be distinguished at any stage.
Aging on mast cells and plasmacytes in the brain of hamsters
Authors: Kelsall Margaret A.
Published: February 2005

Mast cells occurred along the internal cerebral veins in the brain of 55 female and 75 male Syrian hamsters, 35 to 844 days old. Observations on serial parasagittal sections stained with toluidin blue indicated that the largest aggregation of mast cells was in the arachnoid layer between the velum interpositum near the origin of the internal cerebral veins. Mast cells were aligned along short segments of thalamic veins usually near their entrances into the internal cerebral vein or along capillaries in the thalamus of 28 of 45 hamsters, 500 to 844 days old, but were absent in the thalamus of the 17 less than 200 days old. Mast cells and plasmacytes were present in the choroid plexuses of the lateral and third ventricles in 29 of 41, 521 to 844 days old, but were not found in the choroid plexuses of 42 hamsters, 35 to 381 days old, Plasmacytes but no mast cells occurred in the subfornical organ of 18 of 26, 500 to 775 days old and in only 1 of 13 less than a year old. Hibernation, binding of biogenic amines, and vasodilation are topics of discussion on the significance of heparin and histamine in mast cells.
Maturation and water composition of murine cerebrum, cerebellum, brain stem and spinal cord
Authors: Blinderman Elliott , Brown W. Jann
Published: February 2005

Percentage change in water content and total solids was determined for the developing murine brain for both males and females from birth to 120 days.

The central nervous system was divided into four components: (1) cerebrum (2) cerebellum (3) brain stem (4) spinal cord. The percentage of water was determined by dessication for groups of five animals at each day from birth to 20 days and then at five‐day increments to day 60 and at day 90 and day 120.

Plots of the per cent solids (water content) against body weight showed a linear relationship for all parts except the cerebellum. No sex differences were noted. The cerebellum showed an early rapid water loss with a changing rate to a linear curve as the animal matured.

Growth data were submitted to asymptotic regression using a computer to fit a curve y = α+βρx when y is the per cent solid at time × (in days) and α, β, ρ the constants to be determined. All of the central nervous system components gave constants of the same order of magnitude.
An enzymatic procedure for dechorionating the fish embryo, Oryzias latipes
Authors: Smithberg Morris
Published: February 2005

The tough, fibrous resilient, acellular capsule (chorion) of fish embryos has been characterized as protein‐keratin‐like in composition. It has resisted digestion by common proteinases, such as trypsin, chymotrypsin, pepsin, and papain. We have been able to remove the chorion with pronase, a commercially available (Calbiochem) proteolytic enzyme of bacterial origin with broad substrate specificity.

The enzyme at concentrations of between 0.5 and 0.00625% was tested at room temperatures in several Ca++ and Mg++‐free solutions including a weak salt solution (0.1% NaCl), Yamamoto solution (0.7% NaCl), and distilled water with either phosphate or Tris buffer at pH 6.0–11.5. The embryos were in their first day of development at the start of the treatment.

It was found that the enzyme was most effective in Tris‐buffered water, less so in weak salt solution and least effective in Yamamoto solution. Phosphate buffer caused some precipitation of the enzyme. The chorion was thinned over a wide range of pH (7.0–11.0) and in concentrations of enzyme between 0.5–0.0125% within 21–36 hours. Although the embryos frequently escaped from the thinned chorion by rhythmical movements, many of the embryos could be removed easily with the aid of common forceps. Once removed from the chorion the embryos were placed in phosphate buffered weak salt solution (Rugh), where, with few exceptions, they developed normally.

Considering least mortality and highest yield of embryos with maximally thinned chorions, Tris‐buffered distilled water at pH 9.5 or 10.0 in an enzyme concentration of 0.025% was found to be optimal. Under these conditions 78% of the total number of embryos treated had completely thinned chorions within 24 hours.
The distribution of vitamin C in the human fetus. Histochemical observations
Authors: Hörnblad Yngve , Swinyard Chester A.
Published: February 2005

The distribution of ascorbic acid in 17 tissues and organs of 20 human fetuses (10–23 weeks of age), was studied histochemically by means of the silver nitrate technic. The metallic silver precipitates which were formed by silver nitrate reduction by ascorbic acid could only be uniformly seen in tissues where quantitative biochemical studies indicated the concentration to be greater than 10 mg/100 gm of tissue. The human fetus derives its supply of ascorbic acid from maternal sources and there were no significant differences between the youngest (10 weeks) and oldest fetuses (23 weeks) studied. The concentration and uniformity of distribution of ascorbic acid throughout the organ was most conspicuous in the adrenal and thyroid gland, liver and the proximal convoluted tubules of the kidneys. In the pancreas no ascorbic acid was found in Islet cells but occasional alveolar cells were filled with precipitates. Fine granulation was observed in germ cells of the gonads and heavier accumulation in the follicular supporting cells and interstitial cells of Leydig. Muscle fibers did not reveal granulation but perivascular connective tissue cells in muscle and glands were occasionally heavily granulated.
Observations on the yolk sac and reichert's membrane of ectopic mouse embryos
Authors: Porter David G.
Published: February 2005

Embryos developing from mouse blastocysts transplanted to the kidneys and testes of recipient mice were studied by light and electron microscopy. The yolk sac and Reichert's membrane of ectopic embryos were morphologically normal and had normal staining and histochemical properties. In electron micrographs Reichert's membrane was of low electron density and had a fine fibrillar structure. The cells of the parietal material within their ergastoplasm that closely resembled the membrane both in texture and electron density. The probability that the parietal yolk sac cells are responsible for the elaboration of Reichert's membrane in the mouse is discussed in relation to other work on the subject.

The occurrence of discrete eosinophilic bodies in transplants in which the development of the inner cell mass was abortive is reported. The light microscopic appearance and fine structure of these bodies revealed close similarities to the parietal yolk sac and to Reichert's membrane. It is concluded that they represent yolk sac cells embedded in an abnormal Reichert's membrane.
A fluorescence and electron microscopic study on central monoamine nerve cells
Authors: Fuxe Kjell , Hökfelt Tomas , Nilsson Ove , Reinius Staffan
Published: February 2005

By combining the histochemical fluorescence method for catecholamines (CA) and 5‐hydroxytryptamine (5‐HT) with electron microscopy it has been possible to study the ultrastructure of the central CA and 5‐HT nerve cells of the locus coeruleus and the nuc. raphe dorsalis. The CA and the 5‐HT nerve cells have the same ultrastructural characteristics: a well‐developed granular reticulum and a peri‐nuclearly situated, prominent Golgi apparatus which almost completely surrounds the nucleus. Agranular vesicles (300–500 Å in diameter) are found mainly in a perinuclear area in association with the Golgi apparatus. They are similar to the small agranular vesicles present in large numbers in the presynaptic bags. A few complex vesicles and granular vesicles (600–1200 Å in diameter) are noticed throughout the cytoplasm. No certain changes are observed in the different types of vesicles after treatment with reserpine or MAO inhibitors.

It is suggested that the agranular vesicles contain CA, since these vesicles are most numerous in a perinuclear area where the concentration of the amines are highest. In spite of the low number of agranular vesicles present as compared to the high number found in nerve terminals they might store at least a considerable part of the amines, since the amine concentrations are much lower (100–1000 X) in the nerve cells than in the terminals.
Regulation of pigment cell colonization of PET mouse leg muscles
Authors: Reams Willie M.
Published: February 2005

The results of autoplastic and homoplastic transplants of PET mouse tissues indicate that the state of differentiation of the developing muscles limits the extent of invasion by pigment cells of the muscles of the leg in PET mice. Additionally, intracoelomic grafts into host chick embryos of PET mouse leg tissues has given evidence which suggests that the pigment cell behavior is affected also by a restriction of pigment cell proliferation and concurrent migration by the initiation of pigment cell morphogenesis. Thus it appears that the colonization of the leg muscles by pigment cells in the PET mouse is governed both by the structural limitations and morphogenetic influence imposed upon the melanoblasts by the tissue substrate.
Ultrastructure of the thymic reticulum in guinea pig cytological aspects of the problem of the thymic secretion
Authors: Izard Jacques
Published: February 2005

Thymic reticular cells of the guinea pig were studied at different stages of its development and involution: the fetus of the last third of pregnancy, the newborn, the puberal adult and the adult implanted with estradiol.

Most of the reticular cells were epithelial with desmosomes and tonofilaments originating from the endodermic primordium. In the medulla, some of these epithelial cells appeared to be transformed into elements of Hassall's corpuscles with an increase of tonofilaments in close association with keratohyalin granules.

Moreover, phagocytic reticular cells were occasionally seen. Their origin remains unknown (epithelial or menschymal ?).

The problem of the thymic secretion is discussed. There was no convincing evidence of a secretion of protein or polypeptid inside these reticular cells whatever the age of the animal. However, it is not possible to exclude the presence of another form of endocrin secretion, especially a colloid or a steroid secretion, at least in the fetus and newborn thymus.
The effect of a muscle relaxant on the growth and differentiation of skeletal muscles in the chick embryo
Authors: Ahmed Yehia Y.
Published: February 2005

The present work is concerned with the extreme controversy of views over the problem of the dependency of embryonic muscular development on neural factors.

A chemopharmacological method was adopted to selectively block the motor nerve endings. One hundred and seventy‐seven chick embryos, 6–7 days old, were injected in ovo with marginal doses of oily tubocurarine. The control embryos were injected with arachis oil. Eleven days after injection, the majority of the embryos injected with curare were macroscopically stunted, especially the limbs. Specimens from experimental and control embryos were fixed simultaneously in isotonic 10% formalin made in Howard's solution. Sections were stained with hematoxylin and eosin, Mallory's phosphotungstic acid hematoxylin and Van Gieson. Dawson's technique was used to demonstrate the whole of the embryo skeletons. Microscopic examination of the limb musculature revealed inhibition of development and differentiation. The muscle fibers were reduced in size and number, poorly striated and contained many centrally situated nuclei.

In the chick, it is suggested that at a critical time of development the final differentiation and maturation of skeletal muscles begin to become dependent on the anatomical and physiological intactness of the motor nerves. This time is found to be approximately between the sixth and seventh days of incubation. The significance of these observations is discussed.
The effect of pregnancy on the submandibular glands of mice
Authors: Travill Anthony
Published: February 2005

Structural changes occurring in the submandibular glands of mice during pregnancy were studied. The submandibular glands of 12 mice were examined immediately post‐partum, and those of a further 12 six weeks post‐partum. They were compared with glands of virgin female and young adult male mice. The mean weight of the glands immediately after pregnancy was 75% greater than that of the glands of virgin female mice of the same age.

In both hematoxylin and eosin, and Mallory‐Heidenhain stained sections there was evidence of masculinization of the submandibular glands during pregnancy. The percentage of convoluted granular tubules in the glands increased; as did also the diameter of the tubules. The characteristic appearance of the constituent cells of the tubules in the gland of the virgin female, with basal striations and centrally located nuclei was converted to that seen typically in the young adult male, where the cells have basally located nuclei, and an abundance of apical granules but no basal striations.

Regression in both the weight and microscopical appearance of the glands to the non‐pregnant condition occurred within the six weeks following pregnancy.

The apparent masculinization of the submandibular glands during pregnancy is thought to be an expression of the complementary endocrine factors acting at that time.
Fine structure of the seminiferous tubule of the swiss mouse. The spermatid
Authors: Gardner Paul J.
Published: February 2005

Electron micrographs from this study demonstrate several stages in the formation of the nuclear cap and acrosome by the Golgi system. Formation of small vesicles from Golgi membranes, coalescence of these vesicles into the nuclear cap with concomitant fusion of contained granules to form the acrosome, is confirmed. Mitchondria, which at low magnifications appear to be “empty,” are shown by high magnification to contain dilated intracristal spaces. In many cases cristae are arranged parallel to the mitochondrial surface.

In later spermiogenesis, appearance of the caudal sheath or manchette, proximal centriole, and terminal annulus (“ring centriole”) precede formation of the middlepiece and flagellum. The presence of a series of parallel “annulated” membranes has been described. The exact nature of these membranes, which appear to connect with the cisternae of the endoplasmic reticulum, remains to be investigated.
The gross morphology of the coronary arteries of the common squirrel monkey
Authors: Colborn Gene L.
Published: February 2005

The coronary arteries of 16 squirrel monkeys were pre‐perfused with acetone and subsequently filled with vinyl acetate. Thirteen of the hearts were then bleached, dehydrated and cleared in cedar oil; three were subjected to corrosion in concentrated hydrochloric acid.

The right coronary artery arises from the right coronary sinus of Valsalva. In 50% of specimens, the “artery of the conus” arises independently from the same sinus by a separate ostium; in the other 50% being a branch of the proximal portion of the right coronary artery. The right coronary distributes vessels supplying the lateral three‐fourths of the anterior right ventricle, all of the posterior right ventricle, the posterior one‐third of the interventricular septum, the right atrium, the posterior papillary muscles of the right ventricle, the atrioventricular node, the sinus node (in 9 specimens), and the medial one‐third of the posterior left ventricle. The left coronary artery, supplying the remainder of the heart, arises in all cases from the left coronary sinus and bifurcates to form the ventrally terminating anterior interventricular coronary artery and the left coronary circumflex. In one specimen, the left coronary artery supplied the atrioventricular node.
A new cytoplasmic component in the trophoblast cells of the rat and mouse
Authors: Toro Imre , Rohlich Paul
Published: February 2005

Tissue blocks removed from placentas of rats and mice at different gestational age were fixed in either OsO4 or glutaraldehyde or both, embedded into Araldite, and thin sections were examined with the electron microscope. A hitherto undescribed cytoplasmic component consisting of convoluted thread‐like elements embedded in a clear ground substance has been regularly found in the trophoblast II cells of rats and mice. The ovoid‐shaped cytoplasmic component, termed by us glomerular body, is about 1 to 1.5 μ in its greatest diameter and is composed of electrondense 400 to 500 Å thick threads which appear to have a fine filamentous and granular structure. The threads were often observed in close topographical relationship with free ribosomes. The thread‐like elements of the glomerular body were occasionally found dispersed or lined up under the cell membrane of the foetal side of the trophoblast II cell. In some instances similar structures were observed in the nucleus. The nature and significance of the glomerular body is unknown.
Growth of hair in the ventral glands of castrate gerbils following testosterone administration
Authors: Mitchell Ormond G. , Butcher Earl O.
Published: February 2005

A study was made of the growth of hair in the ventral gland of the adult male gerbil, Meriones unguiculatus. The gland is composed of pilosebaceous complexes in which the hair follicles exhibit a very long anagen and a short telogen. Castration causes an almost immediate cessation of growth of the gland follicles. Daily treatment with 320 μg testosterone proprionate results in re‐establishment of hair growth within 72 hours. Growth continues and at three weeks the ventral gland resembles that of normal animals. No influence was observed of the physiological hair cycle of the general skin on the follicles of the ventral gland or of testosterone on the hair cycle of the general skin. The pilosebaceous complexes of the mid‐ventral skin of the male gerbil are androgen sensitive and differ both morphologically and physiologically from those of the general skin.
Blood and lymph vessels in the jejunal villi of the white rat
Authors: Mohiuddin A.
Published: February 2005

The typical jejunal villus is tongue‐ or chisel‐shaped, in which the lacteal is axial, the artery paraxial and the vein lies near one of the lateral borders. The artery forms a T‐junction with the specially wide marginal capillary at the tip which distributes blood to the greater part of the subepithelial capillary plexus. This plexus is so dense that no epithelial cell is more than 30 μ away from the blood stream. The higher density of the plexus in the tip reflects the higher functional capacity of the epithelium there and the plexus in the base of the villus is less dense in keeping with the lower functional capacity of the basal epithelium. The veinbegins in a manner which does not suggest the presence of an arterio‐venous anastomosis.