bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparative anatomical and neurohistological observations on the tongue of slow loris (Nycticebus coucang)
Authors: Kubota Kinziro , Iwamoto Mitsuo
Published: February 2005

On the dorsum of the slow loris tongue there are three vallate papillae, arranged in an inverted V‐shape. They contain abundant plexiform nerves and isolated nerve cells but have many taste buds only in its sides, closely associated with the subgemmal nerve plexus. Some ducts of serous glands locating deeply in this region directly open on the upper surface passing through the papilla. No foliate papillae are observed in the posterolateral region of the tongue, but instead of them is found a papilla of fungiform type, which wholly contains abundant plexiform nerves and has a furrow without serous gland ducts and taste buds. Furthermore, its summit is at the same level as the surface and same as its base in diameter, and has embryonic taste buds. From these neurohistologic characteristics this papilla should be regarded as an interformed papilla between the foliate and the ordinary fungiform papillae. Tongue lyssa consisting of hyalin cartilage and striated muscles innervated with motor end plate and simple sensory nerves seems to play a role as receptive organ of the tongue. Underneath the tongue is found well‐developed sublingua, which consists of hyalin cartilaginous skeleton and mucosa but has no taste buds. From segmental arrangement of neurovascular spaces in the skeleton it may be an ancestral structure of the tongue.
Radioautographic studies of DNA synthesis in the developing extraembryonic membranes of the mouse
Authors: Saccoman Frank M. , Morgan Charles F. , Wells Lemen J.
Published: February 2005

Tritiated thymidine was injected into pregnant BALB/c mice intravenously at 8, 10, 12, 14 and 16 days of pregnancy. Radioautographs were prepared in order to determine the extent of synthesis of DNA in the extraembryonic membranes at the above stages of gestation. The extent of synthesis of DNA was expressed as a radioactive index. The index is the per cent of labeled nuclei in a population of 1000 observed nuclei. Radioactive indices were determined for the nuclei of the endodermal cells of the visceral yolk sac and of the parietal yolk sac, for the nuclei of the trophoblastic cells of the junctional zone and of the labyrinth and for the nuclei of the trophoblastic giant cells. The observations show that in all of the examined types of cells the synthesis of DNA is extensive at days 10 and 12 of gestation and that it is nearly completed by day 14.
Differences in thyroid activity in several inbred strains of mice
Authors: Mendoza Lorenzo A. , Hamburgh Max , Fuld Howard
Published: February 2005

The rate of daily secretion of thyroid hormone was compared in male mice of five inbred strains, the DBA/2, the C57B1/6, the St/6J, the CBA/J and the Swiss Albino strain.

The method employed to measure thyroid secretion rates is based on a procedure which involves the production of goiters by daily propylthiouracil (PTU) administration in the drinking water and determining subsequently the effective dose of the exogenous thyroxin required to inhibit goiter development and maintain normal control weights of thyroid glands.

Statistically significant differences were observed in output of thyroid hormone between the different genetic strains tested. The levels of thyroid activity were lowest in the temperamentally most active strains (DBA/2 and CBA/J) while the more placid strains exhibited higher levels of thyroid secretion (Swiss Albino and ST/6J).

This unexpected finding is interpreted to indicate that, if there exists any correlation between thyroid hormone and behavior, the more active strains differ from the more placid ones in tissue sensitivity to thyroid hormone rather than in concentration of levels of circulating hormone.
Fine structure of the interstitial cells of leydig in the boar
Authors: Belt W. D. , Cavazos L. F.
Published: February 2005

The interstitial cells of the testis of the boar have been characterized by electron microscopy. The bulk of the cytoplasm, to one side of an eccentrically placed nucleus, consisted predominately of a tightly packed agranular endoplasmic reticulum in a system of anastomosing tubules. Free ribosomes and a few short strands of granular endoplasmic reticulum were present only in a perinuclear or subplasmalemmal location. Mitochondria were abundant as a cluster in the center of the cytosome. Surrounding them were dense bodies, most of which were bounded by a single limiting membrane. The internum of the dense bodies exhibited a variety of appearances. Filaments of 70 Å were common but they were absent near the plasmalemma. Between contiguous cells, irregularly disposed microvilli protruded into an intercellular space of variable dimensions. Some sites of membrane fusion, resulting in maculae occludentes, were observed between adjacent cells, while small desmosomes were observed but rarely. Coated vesicles were frequent near to and continuous with the plasmalemma as well as deeper within the cell, especially in association with elements of the Golgi apparatus.
Delayed incubation: A cause of variability in the embryogenesis of the Japanese quail, Coturnix coturnix japonica
Authors: Manner Harold W. , Granik Barbara H.
Published: February 2005

Eggs of the Japanese quail, Coturnix coturnix japonica were collected over a five‐day period and incubated simultaneously, in accordance with currently accepted commercial practice. After 33 hours of functional incubation, the embryos were fixed and the somites counted to determine the age of the embryo. A great range of variation was encountered, supporting earlier published work. This variability, however, was not random, but inversely related to the length of time the eggs were “held” before incubation. This study suggests that the practice of “holding” eggs be discontinued in all work where uniformity of developmental stages is essential.
DNA synthesis by cultured myocardial cells
Authors: Rumery Ruth E. , Rieke William O.
Published: February 2005

Myocardial cells cultured from ventricles of 4‐day embryonic chick hearts were labeled with H3‐thymidine for the radioautographic study of DNA synthesis and nuclear cycling. After the myoblasts had been in culture for 48 hours and had begun to grow out and contract, the cultures were exposed to H3‐thymidine, 1 μc/ml of Hank's balanced salt solution, for one hour. Pairs of cultures were fixed in methyl alcohol for analysis every two hours over a subsequent period of 60 hours. The total percentage of labeled cells, together with labeled mitotic figures which developed after labeling, determined the average values for generation time and nuclear cycle phases as follows: generation time, 45 hours; DNA synthesis, nine hours; G2 interval, 2–6 hours; G1 interval, 27–33 1/2 hours; and mitosis, one‐half to one hour. Autonomous control of DNA synthesis was observed occasionally in a binucleate cell having only one labeled nucleus, although both nuclei were in a similar phase of mitosis. It is evident from these data that cultured myocardial cells synthesize DNA similarly to other cells.
Chemotaxis of mature and immature blood cells in tissue cultures
Authors: Kass Lawrence , De Bruyn Peter P. H.
Published: February 2005

The chemotactic behavior of the cells of bone marrow, lymph node, and buffy coat has been studied in tissue culture. Heat‐attenuated S. aureus was found to be a consistent and convenient chemotactic agent. Mature granulocytes showed chemotaxis to this agent, whereas bone marrow stem cells did not show chemotaxis. In this respect they behaved like lymphocytes of peripheral blood or of lymphatic tissue, which also do not exhibit chemotactic behavior. The chemotactic, locomotory and morphologic similarities between the lymphocyte and the stem cell of the bone marrow are discussed in relation to the developmental potencies of these cells. Chemotactic behavior of the granulocytes appears to develop between the myelocyte and the metamyelocyte stages. It is possible that the granulocytes have differences in chemotactic ability in vivo also, which could be a factor in the selective migration of the mature granulocytes from their extravascular sites of formation into the peripheral blood. Cells of the erythrocyte series did not show chemotaxis.
Pseudoepiphyses or notches in the non‐epiphyseal end of metacarpal bones in healthy children
Authors: Lee Marjorie M. C. , Garn Stanley M.
Published: February 2005

Longitudinal series of hand x‐rays from healthy white children (116 boys, 118 girls) of Fels growth studies were investigated. Notchings of the nonepiphyseal end of the first, second and fifth metacarpal bones were found in every child. Beginning from infancy or early childhood, the notchings follow a sequence of developmental stages (obtuse‐angle; acute‐angle; cleft: underlying, edge‐to‐edge, overjutting; and fusion) until they disappear one to one and one‐half years before onset of puberty. The notching intensity in the second and the fifth metacarpal bones was rated. A moderate degree of association in notching intensity was demonstrated between brothers and sisters.
Time of transuterine migration and distribution of embryos in the pig
Authors: Dhindsa D. S. , Dziuk P. J. , Norton H. W.
Published: February 2005

The time of intrauterine migration and spacing of embryos was determined in 36 gilts with one oviduct occluded, and in 48 gilts with one ovary. Embryos could enter the uterus from one oviduct only. Uteri of seven pregnant gilts were examined on each of days 6, 7, 8, 9, 10, 11, 12, 13, and 15 of gestation. Migration of embryos from one horn to the other usually occurred first on day 8 or 9. The uterus was occupied completely by day 15. Rate of migration and distribution of embryos was not affected by number of embryos, number of corpora lutea, or by uterine length. Uterine length did not change between days 6 and 15. Bilateral ovariectomy after breeding was associated with arrested growth of embryos, a decreased rate of embryo migration and a reduction in uterine length.
Ultrastructure of neurons in the arcuate nucleus of the rat
Authors: Etcheverry Guillermo Jaim , De Iraldi Amanda Pellegrino
Published: February 2005

In the arcuate nucleus of the normal rat there are two types of neurons. One of them is characterized by a dense cytoplasmic matrix, dilated endoplasmic reticulum cisternae and well developed Golgi complexes; the other cell type by a paler overall appearance. In both of them granulated vesicles of about 1000 Å in diameter with a core of variable density are present. The frequent association between these vesicles and the Golgi complex suggests that they are formed in relation to this organoid. The presence of lysosomes and multivesicular bodies and their close relationship with granulated vesicles is analyzed.

The neuropil of the nucleus is constituted by axons, dendrites and glial processes. The majority of the axon profiles and nerve endings contain a mixed population of clear and granulated vesicles, the latter having a diameter ranging between 600 to 1300 Å.

The finding of granulated vesicles in arcuate neurons is discussed in relation with the known monoamine content of them and the dopaminergic nature of the fibers that form the tuberoinfundibular tract. It is suggested that these granulated vesicles contain primary monoamines.
Regeneration research in the Soviet Union
Authors: Carlson Bruce M.
Published: February 2005

Over the past 20 years Soviet research in regeneration has undergone a shift in emphasis from work on amphibians to mammals. In that period several distinct schools of thought have arisen, and often there has been considerable controversy as to the nature of certain regenerative processes. At present most mammalian tissues and organs are being studied with respect to natural regenerative capacity and means of stimulating further regeneration. The most striking results have been obtained in the areas of muscle and bone regeneration. Progress in other areas has been less spectacular. Considerable effort has been put into devising means of regenerating functional tissue from pathologically changed or irradiated organs. The field of regeneration research in the Soviet Union is quite highly organized and includes a relatively large number of workers. Progress has, to some extent, been impeded by shortages of equipment and biochemical preparations.
The survival and differentiation of fetal membranes grafted into the peritoneal cavity in mice
Authors: Avery Gordon B. , Hunt Carl V.
Published: February 2005

Fetal membranes grafted to the omentum in mice do not degenerate at a time corresponding to the normal termination of the donor pregnancy, as would be expected if a “biological clock” were matching their lifespan with that of the embryo and placenta. Neither, in our experience, did such grafted membranes form a variety of highly differentiated secondary tissues, as some authors have suggested. Rather, the fate of the various components of the membrane seemed different for each cell type. In allogeneic hosts a brisk cellular reaction occurred and the membranes were destroyed. In isogeneic hosts, the grafts was vascularized and healthy membrane‐derived structures were still present after 33 days of grafting (48 days conceptual age). Mesothelial cells remained applied to well‐preserved basement membrane, whereas visceral endoderm cells appeared to degenerate or else detach themselves and become free rounded cells with foamy cytoplasm, sometimes multinucleated. Mesodermal cells accompanying the blood vessels of the membrane probably accounted for the connective tissue stroma seen in these grafts. The normal failure of the fetal membranes to persist in situ after the termination of pregnancy may result from the resistance of the uterine lumen to grafts not having highly invasive properties, together with the general sloughing of the uterine lining which takes place after delivery.
Dynamic microscopic anatomy of the fetal liver III. Erythropoiesis
Authors: McCuskey Robert S.
Published: February 2005

Erythropoiesis was studied in the living fetal and neonatal rabbit liver in situ by in vivo microscopic and routine histologic methods. The results demonstrated in life: (1) that fetal hepatic erythropoiesis occurs extravascularly; (2) that individual erythroid cells late in their development pass by diapedesis from the extravascular compartment into the sinusoids; (3) that diapedesis occurs through the sinusoid wall in all parts of the hepatic lobule and possibly may be through the cytoplasm of the endothelial cells; and (4) that the sinusoid sphincters, the flow of blood through the sinusoids, and the intravascular adhesion of maturing erythroid cells to the endothelium affect the length of time that the erythroid cells remain in the sinusoids prior to their release into the peripheral circulating blood.
A study of some histochemical and phagocytic reactions of the sinus lining cells of the rabbit's spleen
Authors: Snodgrass Michael J.
Published: February 2005

A correlative study using several techniques known to demonstrate reticuloendothelial (RE) cells was undertaken to determine whether the splenic sinus lining cells of the white rabbit should be classified with that group of cells. Like RE cells throughout the animal body, these cells can be demonstrated by silver precipitation techniques, that is, they are metalophilic. They show strong non‐specific esterase enzyme activity but only very slight acid phosphatase enzyme activity and sparingly phagocytize intravenous India ink (carbon), chlorazole black E, and saccharated oxide of iron. These results indicate these cells are reticuloendothelial in nature but are quite inactive when compared to RE cells of the red pulp cords.
The nictitating membranes of primates
Authors: Arao Tatsuyoshi , Perkins Edwin
Published: February 2005

Of 22 species of subhuman primates examined, 21 have a well developed nictitating membrane; it is vestigial only in Pan satyrus/troglodytes. The sizes of membranes range from those that cover only one‐tenth of the eye (Gorilla gorilla) to those that extend over the entire eye (Perodicticus potto and Arctocebus calabarensis). Nictitans, best developed in the lower primates, have a free border that is generally heavily pigmented. With the exception of Galago crassicaudatus, all prosimians studied have a membrane that contains a cartilaginous band; cartilage is also present in Cacajao rubicundus, Cebus albifrons, and Saimiri sciureus. The outer surface of the nictitans of all species of anthropoids has mucous glands; that of the prosimians has few of them. Serous glands are present only in the Lorisoidea; in anthropoids serous glands are confined to the adjacent conjunctiva. Mast cells occur with great frequency in prosimians. Elastic fibers are better developed in anthropoids. Muscle fibers are present only in the nictitating membranes of Lemur monoz and Callithrix aurita. Vellus hairs grow on the outer surface of the nictitans in many of the species studied.
The allantoic placenta of the vampire bat (Desmodus rotundus murinus): A reinterpretation of its structure based on electron microscopic observations
Authors: Björkman Nils H. , Wimsatt William A.
Published: February 2005

The chorioallantoic placental barrier of the vampire bat Desmodus rotundus murinus has been studied by electron microscopy. The following elements of the placental labyrinth separate the maternal and fetal circulations: (1) An initially continuous but later discontinuous maternal endothelium, (2) a discontinuous amorphous interstitial membrane, (3) syncytial trophoblast, (4) cytotrophoblast intermingled with a few light cells, (5) a thick basement membrane, (6) mesenchyme, and (7) fetal endothelium. The mesenchyme as a constituent of the barrier is partly bypassed by fetal capillaries. The maternal endothelial cells diminish in number as gestation proceeds, but the interstitial membrane persists. Cytoplasm from the syncytium penetrates defects in the membrane, replaces the lost maternal endothelium, and forms membrane bounded compartments above the former interstitial membrane, which becomes now mainly an intrasyncytial structure. The endotheliochorial relationship originally existing is gradually converted into a hemodichorial condition, if the continuing presence of the amorphous membrane of initially maternal origin is disregarded. The definitive structure of the allantoic placental barrier thus differes somewhat from the organization earlier proposed by one of us on the basis of light microscopic observations. The persistence of an intrasyncytial lamina derived at least initially from maternal tissue is a novel if not a unique feature of the placenta in higher Chiroptera.
Preimplantation stages of baboon embryos (Papio sp.)
Authors: Hendrickx Andrew G. , Kraemer Duane C.
Published: February 2005

Thirteen baboon embryos were collected at various times before implantation and classified into three stages of development, based on a correlation of morphological development and estimated fertilization age. The fertilization age was estimated by designating the day of mating and/or expected ovulation as day zero. Females were mated with males of proven fertility three days before the estimated onset of perineal deturgescence based on previous cycles. All stages were collected by using an in situ flushing procedure or by flushing the excised oviduct and/or uterus.

The two zygotes comprising stage I were recovered from the oviducts on the first day after fertilization. Stage II contains six embryos ranging in development from four to aproximately 32 cells. They were recovered from the oviducts and uteri on the second to the sixth days after fertilization. Stage III consists of five embryos in the free blastocyst stage which were recovered from uterine washings on the fifth to the eighth day after fertilization. One free blastocyst was recovered with the zona pellucida intact, another was in the process of shedding the zona pellucida, and two blastocysts were recovered after the zona pellucida had been shed. The fifth blastocyst was lost before it could be studied in detail.
Responses of livers of mice to type of dietary fat
Authors: Wicks Mark S. , Ball Carroll R.
Published: February 2005

Nine edible oils or fats (hydrogenated coconut, cod liver, Wesson, linseed, olive, butter, lard, corn and cocoa‐butter) were fed to Swiss albino mice for 90 days to study the effects of saturation, chain length, and essential fatty acid content on the liver. The specific oil or fat (selected for ranges in above variables) was used as the diet fat in a high‐fat (28%), low‐protein (8%), hypolipotropic diet. Half the animals received choline chloride (2 gm/100 gm) as a lipotropic supplement.

Within the supplemented groups, ceroid pigment was limited to livers of mice fed cod liver oil. Among the unsupplemented groups, production of ceroid varied with the iodine value (IV) of the diet fat. Fats with low IV produced no pigment; intermediate IV showed ceroid distended Kupffer cells distributed throughout the hepatic lobule, while large, acellular, vacuolated masses of ceroid resulted from fats with highest IV.

Hepatic liposis was minimal in supplemented groups; maximal in unsupplemented groups. Hepatic stroma was within normal limits in all groups. Production of ceroid pigment appeared to be unrelated to degree of liposis or fibrosis.
Plasma cells in human gingiva: An electron microscope study
Authors: Weinstock Alfred
Published: February 2005

The fine structure of plasma cells in clinically healthy human gingiva has been investigated. The cytoplasm was occupied by a profuse rough endoplasmic reticulum, consisting of parallel and circular arrays of cisternae, which contained a moderately dense, flocculant material. Attached to the cisternal membranes were ribosomal configurations in spirals or coils. Round and elongated mitochondria were distributed in a perinuclear fashion and possessed cristae with sharp angulations along their membranes. A well developed Golgi complex was situated in the cytocentrum adjacent to the nucleus and consisted of three major elements: smoothmembraned saccules with characteristic terminal expansions, vacuoles, and dispersed vesicles. These elements frequently contained material of considerable electron‐opacity. Transitional elements (see text) were observed on the endoplasmic reticulum immediately adjacent to the Golgi complex, and evaginations or “blebs” occurred at variable points along their membranes. Cytoplasmic dense bodies in various stages of development were intimately associated with the Golgi. Small forms were membrane‐bound and contained a fine, dense, granular material. Large bodies were also limited by a unit membrane and demonstrated a crystalline internal structure with a major and minor periodicity of about 100 Å. Russell bodies, as described by previous investigators, were not encountered. It is suggested that the dense bodies are formed by the Golgi complex, and may represent lysosomes or non‐hydrolytic enzyme storage units.
Some anatomic factors having to do with urinary continence
Authors: Roberts Walter Herbert B. , Hunt Guy Marion , Henken Herbert William
Published: February 2005

The levator ani acts synergistically with the sphincter urethrae in the voluntary control of micturition by stretching the urethra and thus narrowing its lumen. Further, because of the high origin of its anterior fibers it pulls the trigonal area of the bladder forward and angulates the urethra. The urogenital diaphragm also is pulled upward and made more horizontal. The concept that the levator compresses the urethra against the symphysis is not valid.

The fibers of the urethral sphincter decussate around the urethra but few if any completely encircle it, even in the male. When it contracts it elevates the perineum slightly but its principal function is to convert the urethral configuration into a horizontal slit. In the male the sphincter conforms somewhat to the apex of the prostate so that it is concave as seen from above and is not the strictly horizontal structure so often portrayed. An internal urethral sphincter is present and may be well defined.

The visceral pelvic fascia, in particular the anterior component of the uterovaginal fascia, which is the pubocervical fascia of the gynecologist, has much smooth muscle in it. This muscle, acting in line with the pelvic axis, would not elevate the trigonal area or the urethrovesical junction but would exert traction on the urethra, narrowing its lumen. It would thus help maintain involuntary control.

The nerve supply of the above structures is considered briefly.
A study on the radial supply of the human brachialis muscle
Authors: Ip M. C. , Chang K. S. F.
Published: February 2005

The fate of the radial nerve in the human brachialis muscle, a subject of dispute regarding its frequency of occurrence and nature of innervation, was studied in eight pairs of this muscle. A constant occurrence of radial supply to the brachialis muscle was found. With the exception of two cases which were discarded on account of defects, all brachialis of the sample definitely showed motor as well as sensory innervations by the radial nerve in addition to the major supply by the musculocutaneous nerve. The number and regional distribution of spindle capsules were also determined in all cases. A complete analysis in one of them showed that 7% of the spindle population in the entire muscle were supplied by the radial nerve and that their distribution was confined to the deep lateral quadrant for an extent about half of the muscle length. The probable dorsal origin of this muscle was discussed.
Lymphomyeloid organs of amphibia. III. Antibody synthesis and lymph glands in larval bullfrogs
Authors: Cooper Edwin L.
Published: February 2005

Bullfrog larvae with lymph glands removed failed to synthesize antibodies to BSA but they rejected skin allografts normally. Tadpoles with unilaterally removed lymph glands had antisera with detectable titers equivalent to unoperated animals. Lymph glands are composed of macrophages which line sinusoids interposed between cords of lymphoid cells.
Direct adrenergic innervation of a teleost melanophore
Authors: Jacobowitz David M. , Laties Alan M.
Published: February 2005

The possibility of sympathetic innervation to melanophores in fish was investigated using a catecholamine histochemical fluorescence method. Catecholamine‐containing fibers were observed to be in close anatomic proximity to the conjunctival and dermal melanophores of the cunner (Tautogolabrus adspersus). It is suggested that the catecholamines released from these adrenergic fibers are capable of causing aggregation of pigment with blanching of skin color.
Observations on the fine structure of peripheral nerve myelin
Authors: Napolitano Leonard M. , Scallen Terence J.
Published: February 2005

The incorporation of digitonin 0.2% w/v in cacodylate buffered glutaraldehyde reduces the amount of cholesterol extracted in the dehydrating (lipid extracting) solutions. The fixative enhances membrane structure and results in the preservation of a double minor period in peripheral myelin. The periodicity obtained is in agreement with those derived from x‐ray diffraction studies.
Light and electron microscopic studies on cellular alterations in the normal bovine placentome
Authors: Björkman Nils H.
Published: February 2005

Placentomes from 12 cows ranging from about 45 days of gestation to full term were studied with light and electron microscopy. The cryptal epithelium and the trophoblast both comprised uninucleate, binucleate and multinucleate cells. The uninucleate cryptal cells were provided with small mitochondria and essentially rough‐surfaced endoplasmic reticulum of varying appearance. The uninucleate trophoblastic cells were characterized by an abundance of mitochondria and by morphological evidence of absorption (pinocytosis and phagocytosis). Mitotic figures and sites with cellular degeneration were frequent on the cryptal side but less so on the trophoblastic side. It is concluded that cell turnover is rapid, being confined mainly to the cryptal cells. This is a process in the continuous growth and remodelling of the placentome. There is morphological evidence that the degenerated cells are absorbed by the trophoblast.
Ultrastructure of uterine smooth muscle following progesterone or progesterone–estrogen treatment
Authors: Bo Walter J. , Odor D. Louise , Rothrock Martha L.
Published: February 2005

The ultrastructural effect of progesterone, alone and in combination with estrogen, on smooth muscle cells of the rat uterus was studied. Adult, bilaterally ovariectomized rats were untreated (controls) or treated with either progesterone (1 mg), estrogen (1 μg) or both on three consecutive days.

Uterine muscle cells appeared larger and myofilaments more abundant in the progesterone‐treated rats than in the other groups of animals. Many micropinocytotic vesicles and several dense bodies were present in muscle cells of control, progesterone and estrogen‐progesterone‐treated rats. In the progestrone‐treated group, smooth muscle cells contained little granular endoplasmic reticulum and few ribosomes and glycogen particles, similar to the controls. Mitochondria were more numerous than in the control animals but similar to those seen in the estrogen or estrogen‐progesterone‐treated rats. Although an accumulation of granular endoplasmic reticulum, free ribosomes, glycogen particles and extensive Golgi complexes occurred in both estrogen and estrogen‐progesterone‐treated rats, they were more extensive in the former group.

The observations indicate that progesterone alters the ultrastructure of the smooth muscle cells but not to the degree observed following estrogen stimulation. It does not markedly inhibit the effect of estrogen on the fine structure of the uterine smooth muscle cells. These observations support previous biochemical studies on glycogen concentration, RNA and protein synthesis in the rat uterus.
Luteotropic complex of the mouse
Authors: Choudary Jasti B. , Greenwald Gilbert S.
Published: February 2005

Pregnant mice were hypophysectomized on day 6 and injected subcutaneously with various hormones from days 6 to 9 to establish the minimal requirements for the maintenance of functional corpora lutea. Luteal activity was assessed by the maintenance of pregnancy, weight of embryonic swellings, mean diameter and morphology of corpora lutea, and vaginal histology.

Treatment with 2 mg progesterone maintained pregnancy but not corpora lutea in three of five animals. However, the embryonic swellings were significantly (P < 0.0005) smaller than those of pregnant control animals. Pregnancy was maintained in all animals when progesterone was combined with 1 μg of estrone. The weights of embryonic swellings and the degree of vaginal mucification in the combined steroid group were similar to those of intact control animals.

Treatment with either ovine prolactin, bovine LH, ovine FSH or estrone failed to maintain corpora lutea or pregnancy. Combined injection of prolactin with LH or estrone did not maintain pregnancy or corpora lutea. On the other hand, treatment with 500 μg of prolactin and 200 μg of FSH maintained pregnancy in 12 of 14 animals. All of the aforementioned parameters of luteal activity were comparable to values in intact, control animals.

The data indicate that luteal function in the mouse during the early post‐implantation period requires a luteotropic complex rather than a single hormone. Prolactin and FSH constitute the minimal luteotropic complex in the pregnant mouse. The luteotropic activity of FSH was not due to its contamination with LH and the effect of FSH was apparently not mediated through estrogen secretion, since pregnancy was not maintained by prolactin and estrone.
Inhibition of limb regeneration in the axolotl after treatment of the skin with actinomycin D
Authors: Carlson Bruce M.
Published: February 2005

In this experiment actinomycin D was used to explore the action of the wound epidermis on underlying tissues during limb regeneration. In axolotl forelimbs the skin was removed from the elbow to the shoulder. Skin from the right limbs was soaked for three hours in actinomycin D (5.0 or 10.0 μg/ml 0.6% NaCl). For controls, skin from left limbs was soaked in 0.6% NaCl for the same period of time. Each piece of skin was orthotopically replanted, and both limbs were amputated through the treated skin, proximal to the elbow. After an initial healing period, the control limbs regenerated normally. Except for a slightly paler color, limbs bearing actinomycin‐treated skin were indistinguishable from the controls, both grossly and histologically, during the first week following amputation. While the control limbs formed early blastemas, no grossly visible evidence of regeneration was apparent in the experimental limbs, but histologically some dedifferentiation was occurring. Normally three to four digits were seen in the control regenerates before blastemas appeared on the experimental limbs. By 35–40 days blastemas had appeared on most experimental limbs. These developed very rapidly, and within a short time many of them had attained levels of development close to the controls. Actinomycin D temporarily suppresses formation of the apical epidermal cap and the subsequent aggregation of dedifferentiated cells into a blastema. When the effect wears off, an apical cap forms and the dedifferentiated cells quickly organize into a blastema and begin to differentiate.
Inclusion bodies of type II alveolar cells: Species differences and morphogenesis
Authors: Kikkawa Yutaka , Spitzer Richard
Published: February 2005

In order to evaluate pathological alterations of the inclusion bodies of Type II cells in the mammalian lung, normal morphology of inclusions has been studied in rabbit, sheep, rat, mouse, dog, hamster and guinea pig. In rabbit, and sheep the fetal development of the inclusions has also been investigated.

After a standard method of fixation, three different types of inclusions have been found in the species studied. The first type of inclusion is seen in the fetal rabbit, fetal sheep, dog, rat and mouse. In these species the inclusions contain heavily osmiophilic, coarsely lamellar material. In all of these species, the inclusions seem to form from an interaction between tubulo‐vesicular bodies, located near the Golgi apparatus, and multivesicular bodies. These are certain variations in the appearance of the inclusions among these species.

The second type of inclusion is seen in the hamster and guinea pig, in which lightly osmiophilic material accumulates during the maturation of the inclusions. In these species, a granular dense body seems to occupy an important role in the formation of the inclusion bodies.

In the third group, the postnatal rabbit and sheep, the inclusions appear vacuolated.

It is postulated that the seemingly inconsistent results of the acid phosphatase activity of inclusions in several species may indeed be a reflection of species differences in the mode of formation of inclusion bodies.
The influence of pituitary hormones and norepinephrine on the size of adipose cells in organ culture
Authors: Slavin Bernard G. , Elias Joel J.
Published: February 2005

The technique of organ culture was used to test the effects of various pituitary hormones and norepinephrine on the size of brown and white adipose cells of mice. The hormonal effects were measured by means of histologic analysis and cell width measurements. A concentration of 10 μg/ml of somatotropin (STH), adrenocorticotropin (ACTH) or lipotropin (LPH) was sufficient to reduce the size and content of intracellular lipid in white fat cells while a concentration of 100 μg/ml was required for similar effects on brown fat cells. Norepinephrine, at concentrations of 0.1 μg/ml or 1.0 μg/ml, was sufficient to reduce markedly the size and lipid content of both types of adipose cells. On a molar basis, these hormones acted in a similar range of concentration. The reduction in size and amount of intracellular lipid in brown and white adipose cells by STH, ACTH, and LPH were prevented when combined with 10 μg/ml of insulin. Insulin prevented the lipid depletion effect of norepinephrine in brown but not white adipose cells.
Cytoplasmic fine structure during hormonally controlled differentiation in vaginal epithelium
Authors: Eddy Edward M. , Walker Bruce E.
Published: February 2005

Cells of the vaginal epithelium of ovariectomized mice undergo differentiation in response to estrogen or progesterone injection. Estrogen causes an increase in number of cytoplasmic filaments in the basal and newly formed spinous layer and mucification of surface cells already present. The cells derived from the basal layer under estrogen influence later form a keratinized epithelium. Progesterone causes heightening and mucification of surface cells and invasion of leucocytes into the epithelium without mucification or keratinization of other cells. When estrogen is followed two days later by progesterone, spinous and more superficial cells are lost and replaced my mucous cells derived from the basal layer. Although the fine structure of basal and spinous cell cytoplasm looks identical, the spinous cells do not form mucous cells under progesterone influence. The reverse sequence of progesterone followed by estrogen produces a low epithelium which is then replaced by a keratinized epithelium. The surface mucous cells present during progesterone influence do not keratinize, however. Thus, fine structural features of basal cells typical for the influence of a given hormone do not limit or characterize the potential of daughter cells derived from that layer. Conversely, when hormones are used in sequence, cells which leave the basal layer under the influence of one hormone do not acquire the fine structural features characteristically produced by the second hormone used, even though basal cells are readily altered.
Nerve endings in skin of the australian black snake
Authors: Proske Uwe
Published: February 2005

Histological preparations from skin of the Australian black snake, Pseudechis Porthyriacus have revealed myelinated nerve fibers terminating in several structures. The commonest of these, the simple “End Button,” was seen in the epidermis from all regions of the body. An end organ, the “touch corpuscle” occurred in the epidermis of the upper and lower lip, while in the dermis of the upper and lower jaw an encapsulated structure, the “club corpuscle” was frequently encountered. These more complex structures could not be revealed in skin of the trunk where only “end buttons” were seen.
Light and electron microscopy of the adrenal medulla of macaca mulata monkey
Authors: Al‐Lami Fadhil
Published: February 2005

The fine structure of the adrenal medulla of Macaca mulata monkey was studied after double fixation with paraformaldehyde and OsO4; other fixations were employed for comparison. Only one cell type was seen. The cytoplasm contained an uneven distribution of chromaffin vesicles which were either spherical or elongated and 0.1–0.3 μ in diameter. There were two principle vesicle categories: dark and compact forms which comprised the majority (about 80%) and lighter, mostly larger, vesicles with a finely granulated appearance. The Golgi apparatus was often seen in relatively clear areas where few other organelles were present. Vesicles, 0.1–0.2 μ in diameter, which stained heterogeneously were also observed. They were few in number and always associated with the Golgi apparatus. The chromaffin cells lay in close proximity, but in no specific relationship, to thin‐walled blood vessels. Nerve endings which were partially embraced by Schwann cells were in synaptic relation to the chromaffin cells.

These findings are compared with previous observations in other mammals and the nature of the dark and light vesicles is discussed.
Spermatogenesis in the rabbit following ligation of the epididymidis at different levels
Authors: Paufler S. K. , Foote R. H.
Published: February 2005

Ligatures were placed unilaterally on the ductus deferens (experiment 1), on the ductus deferens and the middle of the corpus epididymidis (experiment 2) and on the ductus deferens, corpus epididymidis and ductuli efferentes (experiment 3) in 39 rabbits. The untreated contralateral side served as a control. Vasectomy alone appeared to have no effect upon the testes, or upon spermatozoa accumulated during a period of 12 weeks proximal to the ligature. In experiment 2 severe disruption of spermatogenesis occurred. Diameter of the seminiferous tubules decreased, testes atrophied, and the stages of the seminiferous epithelium were abnormal and often not classifiable. Some regeneration was observed after 12 weeks.

In experiment 3 there was only a moderate and more transient disturbance of spermatogenesis. This occurred in spite of an accumulation of fluid in the testis due to the ligature on the ductuli efferentes, which prevented testicular effluent from reaching the caput epididymidis. These results suggest that when testicular effluent is allowed to reach the caput, but nonresorbed residues are prevented from further transport (experiment 2), a feedback to the testis occurs which is more harmful than that produced by preventing tubular contents from leaving the testes.
The ultrastructure of granulosa cells in the newborn rabbit ovary
Authors: Gondos Bernard
Published: February 2005

In the first two weeks of life the pregranulosa cells located in the sex cords of the rabbit ovary become increasingly flattened and elongated to isolate and encircle individual oocytes. During this period there is a marked increase in the amount of intracytoplasmic lipid in the pregranulosa cells. The lipid is associated in clusters with adjacent mitochondria. The accumulation of lipid deposits within the pregranulosa cells suggests that the newborn rabbit ovary may be capable of steroid synthesis.
A quantitative study of the nucleus of the mesencephalic tract of the trigeminal nerve of the cat
Authors: Dault Stephen H. , Dale Smith R.
Published: February 2005

The number of cells in the mesencephalic nuclei of 38 cats averaged 2015 and ranged from 1237 to 2946. The individual right and left nuclei averaged 980 cells and ranged from 581 to 1489. About 3% of the cells were chromatolytic in the control animals.

Various nerves were sectioned and the animals were sacrificed 14 days later. After unilateral section of the nerve to the masseter muscle 18% of the cells in the ipsi‐ and 9.7% of the cells in the contralateral nuclei were chromatolytic. After simultaneous unilateral section of the nerves to both the masseter and temporalis muscles 3% of the ipsi‐ and 23% of the cells of the contralateral nuclei were chromatolytic. After unilateral section of the inferior alveolar nerves 13% of the cells of the ipsi‐ and 9% of the cells of the contralateral nuclei were chromatolytic. After unilateral section of the lingual nerves 9% of the cells of the ipsi‐ and 7% of the cells of the contralateral nuclei were chromatolytic. After unilateral section of the hypoglossal nerves 12% of the ipsi‐ and 10% of the cells of the contralateral nuclei were chromatolytic.

These results provide anatomical evidence that the axons of the cells of the mesencephalic nuclei are distributed to both the ipsi‐ and contralateral peripheral nerves. These findings also confirm the presence of such axons in the lingual and inferior alveolar nerves and demonstrate their heretofore unsuspected presence in the hypoglossal nerve.
H3‐leucine incorporation in antigenically stimulated rat popliteal lymph node cells
Authors: Slonecker Charles E.
Published: February 2005

The effect of antigenic stimulation with pertussis and sheep red blood cell antigens was studied in the rat popliteal lymph nodes. H3‐leucine was used to assess protein metabolism in the various cell types of the reactive lymph nodes following both primary and secondary stimulation with these antigens. Radioautographs of tissue smears were used to make quantitative and qualitative assessments of the extent of intracellular protein synthesis. In addition, changes in the cellular populations of various lymphoid cell lines were determined utilizing differential cell counts and total cells present in the reacting nodes. These data were used principally to assess the role of the lymphocytic cells in the ontogeny of the immune response.

Large and medium lymphocytes responded to antigenic stimuli by increasing intracellular protein synthesis. This newly synthesized protein most likely reflected the requirements of large and medium lymphocytes for growth, division and the production of immunoglobulins. The small lymphocytes, as a group, showed only minimal changes in intracellular protein synthesis following antigenic stimulation.

The responses by large and medium lymphocytes and plasma cells were qualitatively similar following primary and secondary stimuli. The differences in these responses appeared to be reflected by the number of cells involved and by the temporal sequence in which the cells appeared.
The placenta of the four‐eyed opossum (philander opossum)Philander opossum)
Authors: Enders Allen C. , Enders Robert K.
Published: February 2005

The placental membranes of the four‐eyed opossum were studied by light and electron microscopy. The individual fetuses in each uterus were surrounded by amnion, had allantoic sacs of approximately the same size as each fetus, and were situated in a common yolk sac cavity. The extent of the choriovitelline placenta was marked by a prominent sinus terminalis, and at this margin there was a region where the trophoblast cells penetrated folds of the endometrium. Elsewhere the choriovitelline placenta was closely applied to the uterine epithelium along most of its surface, but the microvilli of the two epithelia did not interdigitate. Numerous inclusion bodies were seen in the trophoblast of both the choriovitelline and bilaminar omphalopleure portions of the placenta, but the aggregates were larger in the latter. The endoderm cells of the choriovitelline placenta had extensive endoplasmic reticulum and numerous mitochondria, but did not have conspicuous absorption canaliculi.

Placentation in the four‐eyed opossum appears to represent a progressive advance over that of the Virginia opossum both in confluence of the yolk sacs of the fetuses and in having a region of penetration of the maternal endometrium by trophoblast.
Studies on the innervation of the medial meniscus in the human knee joint
Authors: Wilson A. S. , Legg P. G. , McNeur J. C.
Published: February 2005

Histological and ultrastructural studies on the medial meniscus in the human knee joint show that nerve fibres, both myelinated and unmyelinated, extend from the periarticular plexus into the meniscus as far as the intermediate third. These neural elements are not exclusively paravascular in position and it is reasonable to postulate a function other than vasomotor or vasosensory for them.
Alterations in fine structure of the opossum adrenal cortex following sodium deprivation
Authors: Long John A. , Jones Albert L.
Published: February 2005

The fine structure of adrenal cortices of opossums maintained on a sodium deficient diet for 21 days has been examined. After this treatment, the thickness of the zona glomerulosa is increased due to hypertrophy and hyperplasia of the parenchymal cells. After 21 days on the low sodium diet, the glomerulosa cells are characterized by large accumulations of smooth surfaced endoplasmic reticulum. This appearance is in marked contrast to the sparse representation of smooth surfaced reticulum in control animals. The rough surfaced endoplasmic reticulum becomes organized into long flattened cisternal profiles in parallel array and appears to be increased in quantity. The Golgi complex is also hypertrophied but marked changes in other organelles were not observed. Cells of the zona fasciculata appear to be unaffected by sodium depletion. Large lipid droplets accumulate in the zona reticularis of experimental animals but this zone is otherwise comparable to control animals. The bearing of these results on hypotheses of physiological control of secretion of the zona glomerulosa are discussed.