bluuebunny/crossref_metadata_2025 huggingface dataset:
Holocrine secretory cells of the rat epididymis
Authors: Martan Jan , Risley Paul L.
Published: February 2005

Epithelial cells of the rat epididymis are of two major types, principal and holocrine. So called basal, apical, and clear cells represent different stages of the holocrine cell cycle in which it accumulates secretion products, dies, and is replaced. The twocell types differ not only in their secretory behavior, but also in mitotic characteristics and staining properties. Condensed mitoses of holocrine cells occur in the basal epithelium, but larger mitotic figures of principal cells occur in their own apical regions. Holocrine cells are acid phosphatase positive only in their activated basal forms, but are strongly PAS and silver positive in all stages except when disintegrating. In principal cells, only the Golgi area is acid phosphatase and silver positive, and small scattered PAS granules also appear in this region. While secretory functions of both cell types are under testicular hormone control, frequent mating releases holocrine cellsfrom the epithelium into the lumen where they disintegrate. A shortened cycle in mated males occurs within 24 hours. Holocrine cells are also present in the rat vas deferens. Cells with similar staining reactions occur in ductuli efferentes and seminal vesicles of the rat, and in epididymides of hamsters and guinea pigs. Similar fixation methods and staining reactions applied to purified glycerylphosphorylcholine indicate that holocrine cells may accumulate and secrete this constituent of epididymal fluids.
Improved fluids for anatomical embalming and storage
Authors: Richins Calvin A. , Roberts Eugene C. , Zeilmann Joseph A.
Published: February 2005

An improved embalming fluid has been developed for anatomical use. Potassium pyrophosphate and magnesium chloride are used to decrease the rigidity associated with formalin fixation. Substitution of sodium pentachlorophenate for phenol improves color relationships and eliminates most of the unpleasant cadaver odor. It gives as much, or more, protection against bacteria and fungi. Sorbitol replaces glycerine as a humectant with less browning of tissues, and a wetting agent is incorporated to facilitate distributionand penetration of the fluid.

Wet storage of cadavers is recommended, and a vat fluid is described for use with the new embalming formula.
Intersexuality with associated mammary gland stimulation in the rat
Authors: Maibenco Helen Craig , Krehbiel Robert H. , Nelson Dorothy
Published: February 2005

Spontaneous intersexuality in an adult rat, thought to be genetically male, has beendescribed. Both male and female primordia developed concurrently and most components ofeach were retained with normal adult characteristics. Gonadal and hypophyseal hormones in this specimen stimulated ductal and lobulo‐alveolar proliferation simulating that of the mammary gland during lactation.
Number of rat ova implanting after sub‐sterilizing X‐irradiation of one or both ovaries
Authors: Krehbiel Robert H. , Plagge James C.
Published: February 2005

Irradiation with 800 r of x‐ray was applied to the exteriorized left ovary, to both ovaries or to the left ovary after unilateral (right) castration of 60day old rats. Treated females were placed with the male at 60, 70, 80 or 90 days of age. Females were explored at eight or nine days after sperm were found in the morning smears to determine the number of implanations.

The number of matings was reduced during the period of normal vaginal cycles. Matings did occur after the unset of continuous vaginal cornification.

Animals with an irradiated left and a normal right ovary maintained an average number of implantations through pregnancies one to seven. The normal ovary compensated for the loss of production by the irradiated ovary. Bilateral irradiation caused a decrease in implantations in the second and third pregnancies. In individual cases, however, thenormal complement for a single ovary occurred as late as 201 days after irradiation. The irradiated ovary in the absence of the other ovary compensated by producing more implantations; its period of production was limited to 31 days following irradiation.
Some limitations of the theoretical approach to problems in morphology
Authors: Turner R. S.
Published: February 2005

The concept of optimal mechanical efficiency as a valuable adaptation in organic evolution leads logically to the measurement of anatomical structures with a view to ascertaining their degree of correspondence to a theoretically optimal design. This idea is here considered as it applies to samples of specimens from human cardiovascular and respiratory systems. It is shown that theoretical criteria of efficiency will indeed predict the mean measurements of the samples with a very high degree of accuracy. In individual cases, however, the correlation between theoretically predicted and actual observedvalues is very poor. The diffeculties inherent in isolating a small part of a total biological system and treating it as a controlled physical system are discussed, as are some of the biological variables which must limit many of the theoretical formulations. It is concluded that until further biological and statistical refinements are possible the present theoretical methods may have only limited practical application.
Studies of an injury‐induced growth in the frog lens
Authors: Rafferty Nancy S.
Published: February 2005

A tumor‐like growth in the lens of Rana pipiens occurs following mechanical injury to the lens. The frequency of occurrence and size of the growth are roughly dependent on the extent of the injury inflicted. The growth first appears four days after wounding, grows actively for three weeks and usually begins to regress after a month. The cells of the growth appear to originate by proliferation of the lens epithelialcells surrounding the wound which grow into and actively invade the lens fibers. The lens growth was not transplantable either homologously into the anterior eye chamber after dissociation, nor isologously in a subcutaneous site. Protein, LDH, MDH, and G‐6‐PD patterns obtained after electrophoretic separation in starch gels were similar for normal and the abnormal lenses. Whether a true tumor or hyperplasia, the froglens exhibits an unique reaction to the injury stimulus which is not found in mammals (man, rabbit, mouse). The controversial tumor immunity of the mammalian lens appears to the related to an innate resistance of the epithelium to proliferation which is illustrated in part by the species difference in the reactivity of the mammalian lensand the amphibian lens to injury.
Permanent gross demonstration of the conduction tissue in the dog heart with palladium iodide
Authors: Baerg Richard D. , Bassett David L.
Published: February 2005

A permanent gross demonstration of dog cardiac conduction tissue was attempted unsuccessfully using standard glycogen and fat stains, experimentally induced lipogenesis, iodine, and the iodides of fluorescein, silver, and lead. Staining with insoluble sulfides was also unsuccessful. Permanent gross differentiation of the tissue can be accomplished with palladium iodide. The best fixative for minimum tissue distortion which stillpermits good differentiation is neutralized formol‐saline. The opened and fixed heart is dipped in alcohol for 15 minutes prior to staining, then placed in an iodine‐potassium iodide solution for two to five minutes. It is then rinsed in running water for one minute and transferred to a solution containing PdCl2 and HCl and left for ten minutes. Following the staining reaction, a differentiation lasting several hours is necessary. By this method, the entire sub‐endocardial ramificationof the specialized tissue can be permanently demonstrated. Alternatively, the above process may be replaced by painting the endocardium with the various solutions, the results being equivalent but more localized.
The fine structure of regenerating adrenocortical autotransplants in the rat
Authors: Penney David P. , Patt Donald I. , Dixon Wallace C.
Published: February 2005

The fine structural changes accompanying the regeneration of adrenocortical transplants in the rat were studied with the electron microscope. One‐half gland autotransplants were made to the dorsal musculature of male Wistar rats, weighing approximately 120 gm. Transplants were recovered after 2, 4, 7, 14, 21 and 60 days of regeneration. During the first week of regeneration there was an increase in the granular endoplasmicreticulum at the expense of the agranular form. The internal structure of the numerous mitochondria was transformed from the normal tubular and vesicular forms of the zonae glomerulosa and fasciculata, respectively, to a lamellar type. The quantities of free ribonucleoprotein particles also were reduced. During this period the viable cortical cells are considered to be more deeply involved in protein synthesis and growth rather than hormone biosynthesis. Following 14 days of regeneration and thereafter, the characteristics of the mal intact adrenal cortex became established. Highly osmiophilic “dark cells,” present in the inner zones of the normal intact adrenal cortex, firstappeared after 14 days of regeneration, and were widely scattered throughout the cortexafter three weeks. After two months of regeneration, the “dark cells” were again concentrated in the inner cortical zones. During this latter period, hormone biosynthesis appears to be the major cell function. Possible structural‐functional relationships are discussed.
The preferential removal of bone and tooth collagen
Authors: Quigley Mervyn B. , Zwarych Phyllis D.
Published: February 2005

This investigation was undertaken to remove collagen from bone and tooth sections following fixation, decalcification and sectioning so that the noncollagenous tissues could be better demonstrated. Half heads of white mice were fixed in one of the following:Susa, neutral buffered formalin, ethyl or methyl alcohols. Decalcification was carried out with formic acid‐sodium citrate solution, hydrochloricformic acid mixtures, formic acid alone, or the tetrasodium salt of ethylenediamine tetra‐acetic acid. Paraffin sections were cut at 8 μ. After deparaffinization and hydrations the sections were immersed in one of two solutions, distilled water alone or 0.1% solutionof collagenase in distilled water. The experimental sections were incubated at 37°Cfor periods ranging from two to four days. Sections were then stained with picro naphthol blue black, hematoxylin and eosin, Van Gieson's stain or Masson's stain. The distilled water sections showed no change. The collagenase treated sections showed that the collagen had been removed from the matrix of bone and dentin leaving behind theosteocytes and odontoblast processes.
A report of a 7‐toed foot
Authors: Nelson Edward M.
Published: February 2005

The right foot of a 65‐year old female specimen from the gross anatomy laboratory had seven toes. A study by x‐ray films and dissection showed that two extra toes were inserted within the normal limits of the foot between the hallux and axial digits.

The phalangeal complement of the seven toes was complete but the two extra toes were borne on the bicapitate distal end of a single extra metatarsal. The medial (first) cuneiform tarsal was tripartite.

The flexor musculature was for all practical purposes complete but the extensor musculature absent.
Development of the pancreas of the rat embryo in vitro: Islets and acini
Authors: Schweisthal Michael R. , Céas Maria P. , Wells Lemen J.
Published: February 2005

Developing pancreases from embryos of thirteen and one‐half to seventeen and one‐half days were placed on rayon grids and cultivated on a liquid medium of cock serum and chick embryo extract for periods of two to ten days. The cultures were incubated at 37°C in air supplemented by controlled oxygen and carbon dioxide.

Pancreatic islets develop well in organ culture. This process usually involves increases in the size of islets and in the number of cells per islet, and sometimes involves an increase in the number of islets. The rate of morphogenesis of islets is variable: slower than that in normal controls during equal time in days (most cases) or equal to it (several cases) or faster than it (few cases). The development of islets includes the formation of granulated beta cells (many cases). The beta cells may reach stages as advanced as those in normal pancreases of postnatal day 3 (few cases). The existence of granulated beta cells in cultures from explants too young to have them constitutes convincing morphologic evidence of the production of insulin or pre‐insulin during the periods of culture.

The development of acini in organ culture includes the formation of them from pancreatic primordia with no acini and the appearance of zymogen granules in the acinar cytoplasm. The morphogenesis may reach stages as advanced as those in normal pancreases of prenatal day nineteen and one‐half (several cases).
Observations on the adrenal glands of the mongoose
Authors: McKeever Sturgis , Tomich P. Quentin
Published: February 2005

Adrenal glands from mongooses, classified according to sex, age and reproductive condition, were examined histologically. The capsule, cortical zones and medulla were described and differences exhibited by the various classes were noted. Percentage width of the three cortical zones was computed for the different classes. Similarity in relative weights of glands from animals classified according to age and reproductive condition, as reported in the literature, was reflected in similarity of the histological appearance of glands from animals so classified. Sexual dimorphism in relative weight of adrenals from adult animals was found to be attributable to development of a distinct inner zona fasciculata in adult females. Glands of adults of both sexes were characterized by presence of much connective tissue at the reticularismedulla border. High adrenal weight/body weight ratio in fetuses was attributable to a high degree of vascularization and to presence of many large vacuoles in the cytoplasm of fascicular cells.
Prerequisites for a photoreceptor structure in the crayfish tail ganglion
Authors: Hermann Howard , Stark Lawrence
Published: February 2005

On grounds of electron microscopic appearance (Hama, '60), the side of abdominal photoreceptor organ in crayfish (Orconectes virilis [Hagen]) has been questioned. Illumination of any part of ventral nerve cord (exclusive of A6 ganglion), e.g., A2, A3, A4, A5, and afferent roots of A6, shows no physiological response. A6 alone shows phototransduction process pulses. Sectioning of cord restricts locus to A6. Spurious effects from cephalic eye response were seen.

Physiological investigation has restricted the crayfish‐tail photoreceptor–organ to include photosensitive elements lying only within the sixth abdominal ganglion, and two to four B‐fibers carrying nerve impulse responses through the ventral nerve cord. It is therefore possible to exclude the “Hama‐structures,” associated with the giant fiber system, and located diffusely in the nerve cord, from any role in the phototransduction process. Attention of anatomists is called to this primitive and interesting photoreceptor organ.
The chromosomes of the ovary of the human fetus
Authors: Kindred James E.
Published: February 2005

The chief purpose of this paper is to show that the human fetal ovary is a rich source of large actively dividing cells. The material consisted of the ovaries from five stillborn, morphologically normal human fetuses; 150 mm negro; two, 160 mm white; an 800 gram white; and a term white. The ovaries of the first three fetuses were removed within several hours after birth; those from the last two were removed at autopsy, wrapped in cellophane, placed in an insulated container and mailed to me. These were prepared for study about 36 hours after autopsy. Smears and squashes were made according to modern methods, but no colchicine was used. The nuclei of the ova were very tough and did not respond well to the usual hypotonic technics. Best results were obtained from fragments of the ovary suspended in blood, smeared, dried in the air and stained with Wright's blood stain. Qualitative studies were made of the chromosomes, their shapes during prophase and metaphase of meiosis; and quantitative studies were made by planimetry of the areas of the squashed chromosomes as they occurred in enlarged photographs. The planimeter measurements of areas of squashed haploid chromosomes showed remarkable agreement in percentages of the total chromosome area included within each of the accepted seven classes of chromosomes from nucleus to nucleus. Sample karyotypes were made from nuclei of the five fetuses, but no unequivocal absolute numbers could be counted, because of the twisted condition of the chromosomes and the difficulty in identifying the smallest ones.
The embryonic heart subjected to radar
Authors: Paff George H. , Boucek Robert J. , Nieman Richard E. , Deichmann William B.
Published: February 2005

It is known that microwaves can damage tissue but the cause is poorly understood, e.g., can tissue be damaged in the absence of undesirable heat levels? To answer this question 106 isolated 72 hour embryonic chick hearts were subjected to radar waves at a frequency of 24,000 megacycles, a wave length of 1.25 cm and exposures of 478, 297, 167 and 74 mw/cm2 for lengths of time varying between a few seconds and three minutes. Electrocardiograms were taken as a continuous run before, during and after radar treatment. The hearts were planted in blood plasma on the surface of saran sheet and microwaves were directed through the sheet at the heart. Where necessary a stream of cold air was used to offset undesirable elevation of heat. At exposures of 478 and 297 mw/cm2 damage was swift and devastating. No conclusion seemed justified. However, at an exposure of 167 mw/cm2 it was possible to prevent elevation of temperatures above 38°C. Significantly the hearts showed damage in the ECG, i.e., shortening of the QT interval, increased height and breadth of the T wave and the appearance of a large U wave. Finally at 74 mw/cm2 it was possible to control heat merely by maintaining an ambient temperature below 25°C. Of twenty‐five hearts so exposed, all showed ECG changes mentioned in the previous paragraph. The conclusion seems justified, that radar waves can damage tissue at exposures which do not raise the temperature to a harmful level.
Investigations on the lateral nasal gland of the rat
Authors: Warshawsky Hershey
Published: February 2005

A gland lying in the lateral wall of the nasal cavity of the rat has been described and identified as the “lateral nasal gland.” The gland cups the outer aspect of the alveolar bone of the upper incisor root, and lies between it anteriorly, and the alveolar bone of the root of the first molar posteriorly. It is bounded by the hard palate ventrally, the infraorbital fissure laterally and the nasal mucosa, medially and dorsally. The gland consists of serous acini, the secretion granules of which are rich in PA‐Schiff positive material. These acini are clearly distinguished from the mucous‐secreting nasal mucosal glands which lie in the mucosa and border the acini of the lateral nasal gland. The acini of the lateral nasal gland are drained by intercalated ducts into striated ducts which anastomose to form the principal excretory duct. The latter pursues a long tortuous course beneath the mucosa of the lateral nasal wall to open into the nasal vestibule near the external nares.
Derivatives of cortical cords in adult freemartin gonads of bovine quintuplets
Authors: Rajakoski E. , Hafez E. S. E.
Published: February 2005

The anatomy of reproductive organs including histology and cytology of the gonads of one‐year‐old bovine quintuplets were investigated. The experimental animals were four freemartins and one fertile bull with normal sexual libido. In all four freemartins the cervix was absent but the vestibule and the uterine horns were present. The highest degree of transformation of an ovary toward the male pattern was characterized by absence of germinal epithelium, secondary tunica albuginea, ovarian cortex, and follicles; and by presence of mesothelium, primary tunica, tunica vasculosa, interstitial cells, primary sex cords, centrally located rete, epididymis and ductus deferens.

Least transformation was characterized by partial presence of ovarian cortex with germinal epithelium, secondary tunica and primordial, growing and Graafian follicles with oocytes and nuclei in prophase of heterotypic division and more peripherally located rete. Histological transformation of gonads was parallel to anatomical transformation of reproductive organs. One male embryo was able to masculinize four of the female quintuplets at a lesser degree than that generally reported in the literature for twins and triplets. The histological differences of the right and left gonad of the same freemartin may be due to differences in the stage of embryonic development or, the sensitivity of the gonadal tissues at the time threshold amounts of circulating substances of male origin were available. The presence of oocytes in the luteal structures may indicate that the lutein cells of such structures originate from luteinized unruptured follicles rather than from the interstitial cells.
The vascularization of adrenal transplants in the rat and the effect of X‐irradiation
Authors: Wyman Leland C. , Macchi I. A. , Patt Donald I. , Shaw Brenda
Published: February 2005

Vascularization of subcutaneous (ear) and mesenteric adrenal autografts, homografts, and x‐irradiated autografts was studied microscopically through visualization of small blood vessels by intravascular precipitation of lead chromate. Vascularization of autografts in both sites begins on the third day after transplantation with a surface network of small vessels. Vascular buds penetrate the graft on the fourth day. On the seventh vascularization is complete. Vessels penetrate along regenerated adrenocortical fasciculi. Later, large vessels supplying the network around the graft are prominent and venous sinuses exist near the surface. Vascularization of subcutaneous homotransplants follows the same qualitative course but is chronologically irregular, delayed one or more days in most cases. On the second day an inflammatory vascular reaction occurs around the wound in the ear. Generally, vessels are finer, less well injected than in autografts. Mesenteric homografts, however, are vascularized like mesenteric autografts. X‐irradiation of adrenals in vitro with 2,000 r prior to autografting also produces chronological irregularity and retardation of vascularization, up to 28 days after subcutaneous transplantation, but only during the first 12 days in mesenteric transplants. Except for reduction in size, from the thirteenth day on, x‐irradiated mesenteric transplants are like non‐irradiated controls.
Electron microscopic studies on the red pulp of the rabbit spleen
Authors: Roberts Daniel K. , Latta John S.
Published: February 2005

Electron microscopic studies reveal that the red pulp of the rabbit spleen is composed of reticular cells, reticulum and elements of the blood circulating through it. The three types of reticular cells described follow no definite pattern as to types of spaces they line and are not always adjacent to a basement membrane. Similar or dissimilar cells may line a basement membrane on the same or opposing sides. The entire red pulp area is intercommunicating through pores and junctions of the several spaces and in that area in which no basement membrane exists, the cytoplasmic projections of the reticular cells form a meshwork of spaces. Terminal arterioles are seen to end in collapsed type channels with a change from endothelium to Type I reticular cells. These rapidly join dilated areas. The reticular network of the spleen appears as four types: homogeneous, fibrillar, a combination of these, and reticular cells only. Isolated cilia are found in the reticular cell cytoplasm and are shown to be associated with a basal body and a centriole. The investigation supported the hypothesis that the red pulp of the spleen in the adult rabbit is a functionally dynamic area constantly changing its histological structure, both regarding cells and state of the vascular channels.
Multiple anomalies in a human fetus associated with absence of one umbilical artery
Authors: Bridges J. B. , Morton W. R. M.
Published: February 2005

A malformed human fetus with multiple congenital anomalies including absence of an umbilical artery is described. These anomalies include malpositioning of the apex of the heart; a “mirror image” position of the liver; mal‐rotation of the gut with absence of external demarcation into small and large intestine; failure of development of the cloacal region with imperforate anus and absence of a urethra; undescended testes and bilaterally mal‐placed scrotal sacs, but the presence of a median phallus in spite of the failure of the ventral abdominal wall to develop fully.

Factors known to influence the production of fetal anomalies in man and animals are discussed and a brief review of the literature on single umbilical arteries, which are known to be associated frequently with congenital anomalies, is given.
The human fetal thyroid I. Its weight in relation to body weight, crown‐rump length, foot length and estimated gestation age
Authors: Shepard Thomas H. , Andersen Henning J. , Andersen Helge
Published: February 2005

The weights of 75 human fetal thyroids were analyzed in relation to crown‐rump length, foot length, weight, and estimated gestation age. The ratio of thyroid weight to body weight was lower in the smaller fetuses and gradually increased until the fetus was 70–90 mm in crown‐rump length when the ratio attained a value close to that found in the newborn and adult. This period of development when the relative weight of the thyroid becomes constant coincides with the time of appearance of colloid and the onset of ability to concentrate iodine.

A comparison of estimated age of fetuses in the Danish material and the formalin‐fixed fetuses from the Carnegie Collection shows the Danish fetuses under 40 mm in crown‐rump length to be four to six days older than the average given by Streeter. Streeter may have made his average too low and probably the relative ages of the two groups are comparable.
Transuterine migration and spacing of bovine embryos during gonadotropin‐induced multiple pregnancy
Authors: Hafez E. S. E.
Published: February 2005

Unilaterally ovariectomized and intact cattle were injected with 1,500 i.u. gonadotropins to induce superovulation, inseminated at estrus and autopsied 30 to 60 days post ovulation. The allantochorion was dissected in situ and the viability and position of embryos in utero measured. There was no difference between the intact and unilaterally ovariectomized animals in the number of corpora lutea. One to ten embryos were recovered per cow; intact animals had more embryos than the ovariectomized ones. One to two embryos migrated per uterine horn; the percentage of transuterine migration was lower in the intact animals than in the ovariectomized ones. In unilaterally ovariectomized and intact animals, a single uterine horn could sustain only one or two embryos. When the uterine horn contained one embryo, the embryo occupied the middle or upper two‐thirds of the horn. With the increase of the number of embryos the sites of embryos were unevenly spaced and overcrowded. This phenomenon led to a high rate of fetal mortality especially when the uterine horn contained more than two fetuses and transuterine migration failed to occur. The results are discussed in relation to endocrine mechanisms and species differences as they affect uterine contractions.
The effect of endocrine gland extirpations on the size of nucleoli in rat hypothalamic neurons
Authors: Ifft John D.
Published: February 2005

With the object of investigating the so‐called “feed‐back” mechanism whereby hormones from the various endocrine glands presumably influence the hypothalamus in its regulation of the hypophyseal tropic hormones, the effect of hypophysectomy, ovariectomy, thyroidectomy, adrenalectomy and adrenal medullectomy on the nucleolar size of neurons in 16 hypothalamic nuclei was studied. A total of forty‐five female albino rats was used. The nucleoli were measured under oil by means of a Cooke AEI image splitting eyepiece. For every rat 50 nucleoli in each of the 16 hypothalamic nuclei was measured, a total of 36,000 measurements. Hypophysectomy was found to affect all of the nuclei either after a short period (5 days) or after 60 days. Ovariectomy (20 days) caused nucleolar size changes in six nuclei, thyroidectomy (30 days) in eight, adrenalectomy (14 days) in all of the nuclei and adrenal medullectomy (30 days) in all of the nuclei. The results indicate that the absence of the various hormones does affect the activity of hypothalamic neurons as determined by nucleolar size changes. The use of the present methods also appears to “localize” centers for specific activities in the hypothalamus in some instances (e.g. ovariectomy) but not in others (e.g. adrenalectomy).
The gross morphology of the arterial supply to the trachea, primary bronchi, and esophagus of the rabbit
Authors: Blanding James D. , Ogilvie Robert W. , Hoffman Carolyn L. , Knisely William H.
Published: February 2005

The gross arterial blood supply to the trachea, primary bronchi, and esophagus of six normal domestic rabbits has been studied by the use of injection techniques followed by careful in situ dissections. Several patterns are described with more variation being apparent on the left side.
Saimiri sciureus as an experimental animal
Authors: Beischer D. E. , Furry D. E.
Published: February 2005

Recent Primate research projejcts utilizing the squirrel monkey (Saimiri sciureus) established the need for basic biological data concerning this animal. Included in this present report are discussions of laboratory maintenance, dietary requirements, and antihelminthic thearpy. Original data on birth weight (90–100 gm) and the gestation period (167 ± 2 days) are recorded. The weight distribution of a colony of adult animals maintained in captivity for a period of three years is included. Fresh organ weights from ten animals obtained at necropsy were recorded for brain, pituitary, heart, lungs, spleen, liver, pancreas, kidney, adrenals, and gonads. Body weight, body length, and the length of the esophagus, stomach, duodenum, small intestine, cecum, and colon were recorded. Determination of hematologic values included erythrocyte and leukocyte counts, hemoglobin and hematocrit determination and differential count of white blood cells. Various blood chemistry values are included. Data on heart rate, respiratory rate and body temperature of animals restrained for a 24 hour period are tabulated. Environmental stress and neuroanatomical studies using the squirrel monkey are reviewed.
Observations on the early events of cadmium necrosis of the testis
Authors: Chiquoine A. Duncan
Published: February 2005

A light and electron microscopic study of the early changes which occur in cadmium necrosis of the testis of the mouse was made in an effort to identify the site of action of cadmium. Mice were given a single, intraperitoneal injection of 1% CdCl2 at a dosage of 0.1 ml/10 g body weight and then the testes were fixed for light and electron microscopy at various hourly intervals. The earliest changes which were appreciated by light microscopy consisted of an edema of the intertubular spaces, congestion of blood vessels, and an increased amount of granular precipitate in the connective tissue spaces. By electron microscopy the earlies changes were observed in the endothelium of the testicular vascular bed and consisted of a striking and rapid increase in the prevalence of pinocytotic vesticles suggesting an increased interchanges of fluid between the blood and extravascular spaces. All of these changes preceded any appreciable alteration in the cells of the seminal epithelium. The fact that the earliest alterations are observed in blood vessels suggests that the site of action of cadmium in the production of testicular necrosis is upon the endothelium of the vascular bed.

A comparative series of animals (frog, pigeon, rooster, armadillo, opossum) was also investigated as to their susceptibility to the toxic effects of cadmium. the results from these species, and other species reported by previous investigators, suggest the generality that cadmium necrosis is a phenomenon common to species possessing scrotal testes and absent from those possessing abdominal testes. The opossum is an exception to this generality. These findings are discussed in relation to the blood supply of the testis.
Cadmium‐induced injury of the rat testis
Authors: Mason Karl E. , Brown James A. , Young James O. , Nesbit Robert R.
Published: February 2005

It is well known that cadmium chloride administered as single, subcutaneous, sub‐toxic doses selectively damages the rat testis, producing irreversible injury of the germinal epithelium and temporary damage to the interstitial tissue.

Studies reported here demonstrate that: (1) this injury represents an ischemic necrosis secondary to rapid production of intertubular edema (4 to 6 hours), increased intratesticular pressure, with or without associated hemorrhage, and ultimate interference with testicular blood supply and drainage – not unlike injury following testicular artery ligation; (2) as dosage is progressively reduced to approximately one‐sixth that employed by most investigators, interstitial tissue is unaffected and ischemic necrosis is supplanted by a non‐necrotic degeneration of the germinal epithelium closely resembling, in its histopathology and irreparability, that occurring after vitamin E deficiency; (3) oral administration of vitamin E has no protective effect, and testes of rats critically depleted of E show no increased susceptiblity to cadmium.

Observations on the nature and distribution of tubular injury, and on the vasculature of the testis and epididymis, suggest that the unusual sensitivity of the testis to cadmium is related to unique features of its vasculature; namely, the pulseless, semistagnant flow of blood in the intratesticular course of the testicular artery, which permits cadmium to alter capillary endothelium permeability, causing edema and pressure effects leading to acute anoxia at higher levels of dosage, and diminishing degrees of anoxia with decreasing dosage levels. Comparable morphological features of the proximal segment of the caput epididymis make it likewise susceptible to cadmium injury.
The influence of temperature on skeletal maturation of hypothyroid rats
Authors: Hamburgh Max , Lynn Edward
Published: February 2005

The rate of skeletal maturation as indicated by ossification of bony elements of the central and appendicular skeleton was compared in two groups of hypothyroid young rats, raised at 20°C and 30°C constant environment respectively.

Hypothyroidism was induced by feeding 0.2% propylthiouracil mixed with the food in powdered form to pregnant rats starting on the fifteenth day of gestation and continuing this treatment to the suckling mother until their litters had reached weaning age.

The appearance of epiphyseal centers, of carpal and tarsal centers, middle phalanges and femoral and tibial processes and caudal vertebrae 7–27 is delayed in hypothyroid newborn rats over that of normal controls. Hypothyroid rats raised at 20°C lag more severely behind the controls with respect to skeletal maturation, than do hypothyroid rats raised at 30°C. The latter are intermediate or in some instances their rate of skeletal maturation resembles that of the control group.

The possible significance of the demonstration of diminished requirements for thyroid hormone by the developing rat for studies attempting to identify mechanisms of hormone action in development is briefly discussed.
Cholinesterase distributions in the rat epididymis and vas deferens after castration and sex hormone treatments
Authors: Risley Paul L. , Skrepetos Chris N.
Published: February 2005

Cholinesterase (ChE) distributions in the epithelial and smooth muscle cells and in the peripheral nervous plexus of the reproductive ducts of the male rat are dependent on male sex hormones. Castration results in establishment of a low maintenance level of apical enzyme activity in the epithelial cells; smooth muscles and the nerve plexus of the vas deferens and cauda epididymidis also show reduced enzyme reactions. Testosterone treatment restores the normal enzyme relations in the epithelium and smooth muscles. Estradiol is partially effective, but reaction intensities do not attain normal distrbutions and proportions. Reductions in relative numbers of ChE positive nerve plexus fibers and their enzyme reactivity, and recession to outer muscle layers occur in castrates, but better recoveries follow after testosterone than after estradiol treatments. The results are interpreted to be in agreement with other data relating to smooth muscle behavior and its neural and hormonal regulation. Epithelial cell differentiation is complete in testosterone treated castrates, but is incomplete in estradiol treated cases, although ChE synthesis and duct growth occurs in the latter.
Histochemical studies on developing mast cells
Authors: Burton Alexis L.
Published: February 2005

By means of a new staining procedure (using a mixture of Astra blue and safranin O), studies on the polysaccharides of the mast cell granules were made in adult and embryonic connective tissues of the rat. According to their staining reactivity toward these dyes, it was found that, in the adult tissues, mast cells can be classified into three groups: (1) Astra blue positive mast cells, or “blue” cells; (2) safranin positive mast cells, or “red” cells, which are the most numerous cells; (3) intermediate forms, which exhibit affinity for both dyes, or “mixed” cells. In the embryo, mast cells appear first on the fifteenth‐sixteenth day of development as small round cells, the cytoplasm of which contains flakes of Astra blue positive material; rapidly, this material becomes granular, and on the twenty‐first day (just before birth), a large mast cell population exists in the subcutaneous connective tissue of the embryo, containing only cells of the “blue” type. Eight to 15 days after birth, “red” and “mixed” cells are visible. Progressively, the mast cell population becomes of the adult type. It is thought that these variations in the staining reactivity correspond to the evolution of the cell: the “blue” forms are the younger cells and the “red” forms are the adult mast cells. This is probably related to a progressive increase of the number of strong acidic groups which are present in the polysaccharidic molecule.
Weight responses of tissue slices and albumin‐gelatin gels during formaldehyde fixation with observations upon the effects of pH
Authors: Bernard George R. , Wynn Gail G.
Published: February 2005

Thin slices of rat liver, kidney, and M. rectus femoris and thin, flat pieces of albumin‐gelatin gels (which approximated the tissue slices in mass, dimensions and protein content) were immersed in formalin solutions at various concentrations, in some cases with variable amounts of NaCl (0.11‐0.25M) added, and in some cases buffered at pH values ranging from 3.5–7.0. The slices were weighed at frequent intervals for the first 20 hours of immersion. Weight changes occurred rapidly. With the exception of the neutral buffered formalin curves, three families of response curves were obtained for the three tissues. With both formalin and formalinsaline solutions weight gain was inversely proportional to the solute concentration, but the formaldehyde particles apparently are not involved osmotically. The total osmotic concentration of formalin solutions, therefore, is not a factor in the swelling or shrinking of tissue slices. The presence of contaminants could be responsible for the effective osmotic concentration observed with these solutions. The weight response of slices is influenced by the pH of the formalin. Although the response of the gel system to any particular solution was quantitatively greater, it was qualitatively the same as the tissue slice response.
Histochemical contribution to the study of lysosomes in the rat spinal cord
Authors: Sharma Dharmvir R. , Matzke Howard A.
Published: February 2005

Various histochemical tests were performed to study the nonenzymatic components of lysosomes in the neurons of rat spinal cord. The lysosomal granules are periodic acid Schiff positive and this reaction can be blocked by acetylation, but not by bromination. They are performic and peracetic acid Schiff positive also. Both these reactions can be blocked by bromination. It is concluded that 1:2 glycol as well as ethylene groups are present. Lysosomes stain metachromatically after sulfation and are sudanophilic. They are chemical complexes containing protein, neutral polysaccharide, phospholipids and possibly glycolipids and are present in dendrites as well as axons. A topographical relationshiop exists between lysosomes and Golgi apparatus which was stained with nucleoside diphosphatase method. Lysosomes share Schmorl reaction with lipofuscin pigment. In some preparations there is a tendency for them to be localized along the cell membrane.
Neurosecretion in the hibernating bat. The morphology of the hypothalamo‐hypophyseal system
Authors: Troyer J. Robert
Published: February 2005

The morphology of the hypothalamo‐hypophyseal tract of 35 hibernating bats (Myotis lucifugus lucifugus) was studied in chrome‐alum‐hematoxylin‐phloxine‐stained serial coronal and sagittal sections. Vinyl acetate and wax‐plate reconstructions also aided in describing the two neurosecretory hypothalamic nuclei of this system. The most prominently defined nucleus, the supraoptic, consisted of a smaller portion rostral to the optic tract that was tenuously connected to a larger caudal portion. The probability that some of the posteriorly located cells of the caudal portion represent other hypothalamic nuclei is discussed. The shape and location of the paraventricular nucleus was more difficult to determine. Although the neurosecretory cells of this nucleus were similar in their irregular or eliptical shape to those of the supraoptic nucleus, the majority of the paraventricular cells were smaller and had less of an affinity for the chrome‐alum‐hematoxylin stain.

The majority of CHP‐positive axons originating in the supraoptic nucleus converged toward the median eminence and terminated in the pars nervosa. Most of the axons from the paraventricular nucleus coursed laterally toward the supraoptic nucleus where they followed the pathway described from this nucleus. The localization of CHP‐positive material in the neurohypophysis is presented. Comparisons were made between the morphology of this system in the hibernating bat and that of other species of mammals reported in the literature.
Histopathology of dystrophic and normal mice after timed periods of parabiosis
Authors: Pope Richard S. , Murphy Edwin D. , West William T.
Published: February 2005

Two‐hundred and eight mice were paired as parabionts, or as single controls, with normal mice on the day of weaning. Pairs were sacrificed at 4, 8, 12 and 16 weeks after pairing. Autopsies were performed, organs were weighed and microscopic examination of tissues was performed. The results show a decreased liver weight in parabiosed dystrophics with a concomitant increased liver weight in parabiosed normals. The severity of muscle lesions of parabiosed dystrophics was less than that of counterpart single dystrophics. There was no observed clinical improvement.
The silver staining of reticular fibers by electrophoresis
Authors: Monroe Clyde W. , Harris R. G.
Published: February 2005

In this technique reticulin is stained black with silver by the electrophoretic method. Use Zenker or formalin (10%) fixed tissue, but mordant the latter in Zenker stock for one hour or longer‥ Carry paraffin sections to water; mordant, if necessary; wash well in tap water; transfer to distilled water; place slide in tray containing the ammoniacal silver solution; turn voltage regulator to a potential of 70 v; manipulate the electrodes by passing the negative one back and forth over the section and about 5 mm above it, one minute or less; both electrodes are of 20 gauge copper wire; dip in distilled water; reduce in 5% formalin, three minutes or more; rinse in tap water; to AuCl3, 1–5 minute rinse in tap water; into 5% Na2S2O3. 5 H2O, two minutes; dehydrate, clear, and mount in synthetic resin. This method was used on tissues obtained from human autopsies (liver, lung, scrotum, ovary, esophagus and suprarenal).
Fibrillar elements forming dentin and mineral seeding or crystal nucleation
Authors: Kiguel Enrique
Published: February 2005

There are two different types of fibrils contributing to the formation of the dentinal matrix; (1) a coarse type, (Korff's fibers), are the chief component of the first dentin formed next to the dentino‐enamel junction (mantle dentin), and (2) finer fibrils, which are the main component of subsequent layers of dentin next to the pulp tissue (circumpulpal dentin). It is known that Korff's fibers in developing teeth present both the morphological characteristics of collagen, that is, the 640 Aº banding, and argyrophilic staining properties which are typical of reticular fibers. Upon their transformation into fibers that exhibit both the morphological and staining properties of collagen, mineralization of dentin takes place. Since the Korff's fibers exhibit the 640 Aº banding from the very beginning of their formation and, therefore, prior to mineralization, it is notable that the 640 Aº banding is not critical for initial mineral seeding or crystal nucleation. The factors actually initiating mineralization seem to be chemical changes in predentin just prior to mineralization. The fibers lose their argyrophilic properties, alkaline phosphatase decreases, and a change occurs in the mucopolysaccharides associated with dental fibers.
Etiology of antenatal hydrocephalus induced by folic acid deficiency in the albino rat
Authors: Stempak Jerome G.
Published: February 2005

Wistar strain albino rats were fed a folic acid free diet with added folic acid antagonists (x‐methyl folic acid and 9‐methyl pteroylglutamic acid) for a 48‐hour period beginning on day 8 and ending on day 10 of gestation. The period of deficiency was terminated by an injection of 500 μg of folic acid in water. If the injection was not made, most animals resorbed their litters. Fetuses were excised from days 16 through 20, processed routinely, decalcified, if necessary, embedded in paraffin, serially sectioned, and stained. Newborns were treated similarly. Hydrocephalus was the only defect observed in the treated animals. The serial sections demonstrated an occluded or extremely stenotic aqueduct of Sylvius in every hydrocephalic animal examined. The stenosis was seen to be present as early as the sixteenth day of gestation, and occlusion was observed in 17‐day‐old animals. It is concluded that the defect predisposing to hydrocephalus induced by folic acid deficiency in this strain of rats is extreme stenosis or complete occlusion of the aqueduct of Sylvius.
Studies on the effect of trypan blue in the pregnant armadillo, dasypus novemcinctus
Authors: Ferm Vergil H. , Beaudoin Allan R.
Published: February 2005

Evidence is presented that the hemochorial placenta of the ninebanded armadillo, Dasypus novemcinctus, is permeable to trypan blue when this dye is injected subcutaneously into the mother during the postimplantation period. This permeability appears to be related to a time‐dependent active process or is associated with the maturation of the fetal reticulo‐endothelial system. Spectrophotometric analysis of serum proteins revealed alterations in the dye‐injected mothers as well as in thalidomide‐treated animals as compared to untreated controls. While it is difficult at present to estimate the stage of pregnancy under teratogenic study, it is felt that this unusual experimental animal warrants further study with other teratogenic agents.