bluuebunny/crossref_metadata_2025 huggingface dataset:
Cyclic changes in the squamo‐columnar junction of the mouse cervix uteri
Authors: Graham Charles E.
Published: February 2005

The histological structure of the squamo‐columnar junction of the cervix uteri of mice was studied during the estrous cycle, pregnancy, lactation, and in ovariectomized and estrogen‐stimulated animals. In the absence of endogenous or exogenous estrogen, there was no clear demarcation between the squamous and the columnar epithelium; the epithelium in the zone of transition resembled types previously described in the human cervix that have been regarded as evidence of a metaplasia of columnar to stratified epithelium. However, in the mouse, estrogen stimulation caused the disappearance of the transitional zone so that an abrupt junction resulted. It was concluded that the type of junction is controlled by estrogen, and that the stratified epithelium of the transitional zone may differentiate to produce either keratinized cells or cells of uterine type at its surface.
Internal hernia of embryological origin
Authors: Roberts Walter H. , Dalgleish Arthur E.
Published: February 2005

An anatomical specimen is described in which a considerable part of the small bowel had, apparently, in its return to the abdomen during fetal development invaginated the descending mesocolon and that of the left half of the transverse colon, thus producing a large internal hernia. The ascending branch of the left colic artery and the inferior mesenteric vein were in the neck of the sac, anterior to the loops of bowel entering and emerging from the sac. These relationships were obscured by the fact that there was a broad adhesive band extending from the mesentery of the free loops of small intestine to the descending colon, thus bridging over the vessels. The relationships referred to and as shown in the drawings, which include a cross‐sectional view, would indicate that the mechanism of production of the hernia was as suggested and that there were in fact four layers of peritoneum in the anterior wall of the sac.
Structure and Distribution of muscle spindles in the forepaw lumbricals of the phalanger, Trichosurus vdpecula
Authors: Jones Edward G.
Published: February 2005

Non‐nervous aspects of muscle spindle morphology were examined in 15 forepaw lumbricals of a marsupial, Trichosurus vulpecula, using serial transverse and longitudinal sections. The structure of the spindle was similar to that in other mammals with a few minor differences. One to three nuclear bag type and 2 to 16 nuclear chain type intrafusal fibers were present in all spindles. The fibers were largely distinguishable by differences in length, in diameter at all levels along the length of the spindle, and in the arrangement of their equatorial nuclear aggregations. There was, however, some overlap in that many nuclear chain fibers extended for considerable distances beyond one or both poles of the spindle capsule, and several fibers, otherwise classified as nuclear bag fibers, contained single chains of equatorial nuclei rather than nuclear bags. These findings, together with the observation that all intrafusal fibers were heterogeneous in their distribution of myofibrils, and the evidence of other studies on the innervation and histochemistry of mammalian muscle spindles, suggest that a specific functional separation of intrafusal fibers on strictly morphological grounds may not be entirely valid.

The receptor population in each of nine muscles bore no consistent relation to the total number of extrafusal fibers; this appears to confirm the concept that it is the functional attributes of a muscle, rather than its bulk that determine its spindle content.
Responses of tissues from larval newts to implantation into adult hosts
Authors: Dent James Norman , Benson Don G.
Published: February 2005

Trunk and tail parts from larvae of Triturus virdescens were implanted into pockets made in the trunk epaxial musculature of adult animals of the same species. Histological observations were made on these grafts at intervals up to 60 days and at eight months following implantation. During the first few days after implantation the small, fragile grafts were distorted and compressed by the mechanical restrictions of host tissues, but they began to increase in size and rigidity by 20 days and eventually some reached sizes that exceeded considerably those of equivalent trunk and tail parts in intact control larvae. Differential responses to the host environment were seen among the various tissues of the grafts. As growth proceeded, the proportion of cartilage and bone relative to the other tissues increased. Gut, gut derivatives, nerve cord, and kidney showed initial growth but usually underwent later degenerative changes and declined in relative mass. Muscle and connective tissue did not show degenerative changes but did not increase significantly in mass. Limb‐like protuberances and (in a single graft) a mass of well differentiated testicular tissue were seen. No metastases or infiltrating growths occurred.
The anatomy and histology of XO human embryos and fetuses
Authors: Singh Roderick P. , Carr David H.
Published: February 2005

Thirteen abortuses with a known chromosomal complement of 45 (XO) were collected. Of these, eight contained an embryo or fetus ranging in age from five weeks to four months. Various gross anatomical abnormalities were evident in the four larger specimens and these included horseshoe kidney, unicornate uterus, single umbilical artery and cystic hygroma. One specimen had bilateral cystic hygromata. In all specimens, the gross anatomical appearance of the gonad was normal and, when examined histologically, the presence of primordial germ cells could be demonstrated.

Histological sections of the XO gonads were compared with sections of gonads from known XX specimens of similar ages. There was no significant difference between the XO and XX gonads up to the third intrauterine month. In the older fetuses there was a relative increase in the connective tissue of the XO gonad.

The finding of germ cells in the gonads of the XO fetuses is in contrast to the findings in XO adults who usually do not have germ cells in the gonads.
The effect of phytohemagglutinin on rat thymus cells in vitro
Authors: Schwarz M. Roy , Rieke William O.
Published: February 2005

Cells obtained from the thymus glands of five strains of rats, ranging in age from five hours to five months, were cultured in the presence of phytohemagglutinin according to the method of Rieke and Schwarz ('64). In these cultures, the large and medium lymphocytes in the inoculum gave rise by mitosis to small lymphocytes. Under the influence of PHA, small lymphocytes were transformed into enlarged cells which in turn acted as precursors of small lymphocytes. However, not all small cells in the cultures nor thymic lymphocytes from newborn rats responded to this mitogenic drug. A progressive increase in responsiveness was detected as donors increased from five hours to 32 days of age.
Diagnosis of pregnancy in the squirrel monkey
Authors: Nathan Tikva S. , Rosenblum Leonard A. , Limson Genara , Nelson James H.
Published: February 2005

Diagnostic pregnancy assessments have been carried out in 18 squirrel monkey females using Delfs' method for chorionic gonadotropin bioassay palpatory, x‐ray and other auxiliary techniques. Out of the 24 bioassay tests performed, 11 were positive (one of them weakly positive) and 13 negative. These results were confirmed by the other parallel measures, except in two cases of possible false positive reactions. No false negative results were noted. The implications of the results are discussed in terms of the sensitivity and reliability of the bioassay in the early diagnosis of pregnancy in the squirrel monkey.
Hearts and blood vessels of mice receiving cortisone and estrogens
Authors: Ashburn Allen D. , Williams W. Lane
Published: February 2005

Mice received cortisone alone or concurrently with injections of estrone or diethylstilbestrol.

Cortisone alone produced a high incidence of myocardial necrosis and abscesses in hearts, livers, lungs and kidneys. Staining and culture methods showed bacteria in these abscesses. The same technics failed to show infections in the mice receiving estrogen. Unrelated to other lesions the ventricular myocardium and walls of coronary arteries often contained accumulations of fat. Following concurrent injections of cortisone and an estrogen (estrone or diethylstilbestrol) the incidence of medial hyalinization of coronary arteries was 90%–98%. Edema, hemorrhage and hyalinization were observed in the aorta. In the cortisone plus estrogen groups such mural lesions of vessels developed in the absence of bacterial infection as studied by the above methods. The same was true when such infections were prevented by penicillin. The incidence of inflammatory lesions was less in mice receiving both cortisone and estrogen than in the cortisone (alone) group. Frequency of cortisone‐induced myocardial necrosis and accumulation of myocardial fat were not altered by the estrogens.
Response of articular cartilage of dwarf mice to insulin: Electronmicroscopic studies
Authors: Silberberg Ruth , Hasler Mary , Silberberg Martin
Published: February 2005

The effect of insulin on the ultrastructure of articular chondrocytes was studied in young dwarf mice (dwdw) which lack pituitary eosinophiles and fail to produce STH. Within less than 24 hours, injections of insulin together with dextrose enhanced development of the endoplasmic reticulum and of the Golgi structures, stimulated the mitochondria, and accelerated and intensified glycogen formation. Dextrose alone had a similar, although less marked effect. The findings suggest a slightly promoting influence of insulin on protein synthesis and a conspicuous stimulation of carbohydrate synthesis by articular chondrocytes of hypopituitary dwarf mice thus treated. The results were compared with those obtained previously after treatment with somatotrophin, and the relationship between these two hormones was discussed.
Fine structure of the neurons of the posterior horn in the rat spinal cord
Authors: Nathaniel Edward J. H. , Nathaniel Doris R.
Published: February 2005

The region of the posterior horn of the spinal cord in the lumbosacral region of the rat was studied with the electron microscope. This zone contained neurons, astrocytes, oligodendrocytes and blood vessels. The neurons possessed irregular nuclei which occupied a large portion of the cell. The cytoplasm contained elaborate smooth surfaced membrane systems. The rough surfaced endoplasmic reticulum was small in amount and did not possess an orderly arrangement. Electron dense bodies were invariably found within the neurons. The morphological features, such as an extremely irregular nucleus and elaborate cisterns of smooth surfaced reticulum, indicate a well developed nucleocytoplasmic transport mechanism in the neuron. The vascularity of the area was evidenced by the presence of numerous blood vessels which generally had a perineuronal position. Pericytes were invariably found in close relationship to the endothelial cells of the blood vessels. The nucleus of the pericyte was remarkably dense. The cytoplasm of these cells was extremely attenuated and almost encircled the blood vessels.
The effect of retinol and retinoic acid on the morphology of the rat uterus
Authors: Bo Walter J. , Smith Mavis S.
Published: February 2005

At 20 days of age, 72 Holtzman rats were divided into six groups (10–14 rats/group) and were placed on a vitamin A‐deficient diet. The animals in groups I and II were kept intact, while the animals in the remaining groups were ovariectomized at 20–22 days of age. The rats in groups I, III and V received a dietary supplement of retinoic acid (50 μg) while the diet of the animals in groups II, IV and VI was supplemented with retinol (25 μg). In addition to the dietary supplements the animals of groups V and VI were treated with estradiol dipropionate (1 μg). The dietary supplements and hormone were given three times per week. The rats were autopsied after 15 weeks on the experiment.

In the intact rats of group I metaplastic changes were observed in the luminal and glandular epithelia. With the exception of two uterine sections showing small areas of squamous metaplasia in the glands, morphological alterations of the uterine epithelia were not observed in the rats of group II. Uterine metaplasia was not seen in the rats of groups III and IV. Extensive metaplastic changes were observed in the animals of group V. The endometria of the rats in group VI were lined primarily by high columnar cells, but a few uterine sections contained small foci of stratified squamous metaplasia.

The results indicate that retinol is effective in preventing the morphological changes in the rat uterus due to vitamin A deficiency.
Angiocardiographic studies of the Anuran double circulation
Authors: Angell Charles S. , Hipona Florencio A. , Novick Alvin
Published: February 2005

Angiocardiography was used to investigate cardiovascular flow patterns in the heart and great vessels of the bullfrog and the marine toad. In the frog, these studies revealed a completely selective distribution of right atrial blood to the pulmocutaneous arches. The selective distribution is affected, in part, by the ventricular trabeculae which maintain in the ventricle a separation of right and left atrial blood, by the sequential movement from the ventricle of first right and then left atrial blood, and by a sphincter‐action at the point of division of the truncus arteriosus which effectively shunts right atrial blood into the pulmocutaneous circuit. Left atrial blood in the frog is initially distributed selectively to the systemic arches; late in ventricular systole, some left atrial blood enters the pulmonary circuit. In the toad, both left‐to‐right and right‐to‐left mixing appear to occur, but only after significant periods of selective distribution.
Morphological and histochemical changes in the intrahepatic bile drainage system of the mouse following postnatal cholecystectomy
Authors: Yamada Kazuyori
Published: February 2005

Effects of cholecystectomy at weaning upon the histological, histometrical and histochemical features of the intrahepatic bile drainage system were studied in young adult BUB mice of both sexes. The operation has, in 30 to 40 days, at least three different effects on various portions of the biliary system; (1) proliferative changes of interlobular bile ducts including very small ones, the cholangioles, (2) stimulation of activity of mucin secretion in the lining epithelium of large bile ducts and (3) increased alkaline phosphatase activity of bile canaliculi. In the light of known functions of the gall bladder, the proliferative changes of the interlobular bile ducts and the stimulated mucin secretion of the epithelium of large bile ducts are conceived to be developmental compensations for functions of the gall bladder. However, the increased bile canalicular phosphatase activity seems to indicate that such compensatory mechanism of the intrahepatic biliary system is only partially established at the time of observation.
The fine structure of elastic fibers in the fibrous periosteum of the rat femur
Authors: Taylor John J. , Yeager Vernon L.
Published: February 2005

The fine structure of the elastic fibers found in the fibrous periosteum of the albino rat femur has been described. Tissues were fixed in 3% glutaraldehyde and/or phosphate buffered osmic acid, embedded in Epon, stained with lead citrate and examined in an RCA EMU 3F microscope. The elastic fiber in the layer of fibrous periosteum is found to be composed of an array of longitudinally arranged elastofibrils embedded in a matrix of electron dense amorphous material. On cross section some of these elastofibrils appear to be tubular, presenting a dense cortex and a less dense central or core area. Reasons for these elastofibrils not being clearly and conclusively visualized in previous studies are discussed.
Development and distribution of elastic fibers in the mandibular joint of the mouse. A comparison of fetal, suckling, juvenile and adult stages
Authors: Frommer Jack , Monroe Clyde W.
Published: February 2005

Development and distribution of elastic fibers were studied in mandibular joints of white Swiss mice which ranged from 15 days insemination age to three months postnatal. Paraffin sections were stained with Weigert's resorcin‐fuchsin and Verhoeff's elastic tissue stain.

Elastogenesis does not begin until the major elements of the mandibular joint are present. The first distinct elastic elements appear as granules at the nineteenth to twentieth day insemination age. Early sites of elastogenesis occur in the peripheral portions of the articular disk, at the transition and continuation of fibrous disk tissue with the periarticular tissues, and with the periosteum around the neck of the mandible.

The concentration, length and caliber of fibers is increased markedly during the suckling stage, especially in the walls of the medial and lateral recesses of the synovial cavities, and in the posterior continuation of the disk to form a fibroelastic band of attachment to the squamosal bone. Prominent bands of long elastic fibers appear in the epimysium of the lateral pterygoid and masseter muscles in the young adult.

The central portion of the disk and the articular surfaces of the mandibular condyle and fossa contain no elastic fibers, confirming the contention that these surfaces are not particularly stress‐bearing. Stretch and shearing stresses are created, however, which require extensive elastic fiber development in other joint tissues.
The identification of acidophilic cells in the human Pars distalis
Authors: Conklin James L.
Published: February 2005

Sections of human hypophyses were fixed in either formalin or Bouin's fluid and stained by a variety of acid stains. The stains were employed singly, in combination with each other and in conjunction with various mucoid staining procedures. After these procedures the chromophils of the pars distalis were classified as either acidophilic, mucoid, acidophilic‐mucoid, modified or degranulated. The remaining cells which lacked specific chromophilic granules were classified as chromophobes.

The acidophils after the terminology of Ezrin were designated as cell types I, II and VIII which correspond to the alpha, eta and epsilon cells of Romeis.

Numerous, carminophilic type I cells were present in glands of all ages. Although usually pyramidal or oval in shape they also exhibited a variety of morphologic forms. The type I cells were further subdivided into small, light and dark cells on the basis of size and nuclear characteristics. The type II cell although present in all glands was most frequently observed in fetal and post‐menopausal pituitaries. It was tinctorially identified by the prominent staining of its cytoplasmic granules with erythrosin.

The type VIII cell exhibited staining properties intermediate between cell types I and II. On the basis of tinctorial and morphologic properties it was tentatively identified as a modified type I or type II cell.
A comparative study of the autonomic innervation of the eye in monkey, cat, and rabbit
Authors: Laties Alan M. , Jacobowitz David
Published: February 2005

The autonomic innervation to the eye of monkey, cat and rabbit was studied using a sensitive histofluorometric method for adrenergic nerves and the acetylcholinesterase technique for cholinergic nerves.

In the monkey cornea adrenergic nerves are absent while they are numerous in both the cat and rabbit. There is marked species variation in the amount of autonomic innervation to the filtration area. The iris sphincter and the ciliary muscle have a dual innervation but the relative amount of the adrenergic component to these structures varies widely. The ciliary process in every case has a plentiful adrenergic nerve supply. In the choroid a heavy adrenergic innervation apparatus approaches the choriocapillaris. A layer of fluorescent terminals is found in the retina at the junction of the inner nuclear and inner plexiform layers in all three species. In the adjoining part of the inner nuclear layer lie scattered catecholamine‐containing amacrine cells.
Follicle stimulation as an intrinsic property of human chorionic gonadotropin
Authors: Cole H. H. , Bigelow Mary
Published: February 2005

Antiserum to human chorionic gonadotropin (anti‐HCG) with measured capacity to inhibit its antigen was used in conjunction with HCG in intact immature and in hypophysectomized female rats to determine if this hormone has intrinsic follicle stimulating properties. In intact rats, 100, 200, 500, 1000, 1500, 2000 and 2500 I.U. of HCG were given alone and in conjunction with anti‐HCG. In hypophysectomized rats, 400, 800, 1600, 3200, and 6400 I.U. of HCG were given alone and with anti‐HCG. Anti‐HCG inhibited both the second rise in ovarian weight in intact females and follicular development in hypophysectomized females in a manner anticipated on the basis that these responses depended upon the HCG molecule. In hypophysectomized females inhibitition of follicular growth preceded inhibition of interstitial cell development. This result is also in accord with the view that both of these responses depend upon the HCG molecule.

The anti‐HCG serum did not inhibit synergism between HCG and NIH‐FSH‐S1, an ovine pituitary FSH, with doses of 100 and 200 I.U. of HCG combined with 240 m̈g of FSH. An amount of antiserum which would inhibit 500 I.U. of HCG augmented rather than inhibited the response to 1000 μg of NIH‐FSH‐S1 (43 mg ovarian weight as compared to 29 mg).

We conclude from these data that the HCG molecule has intrinsic follicle stimulating properties.
Organ culture studies of hormone secretion in endocrine glands of fetal guinea pigs III. The relation of testicular hormone to sex differentiation of the reproductive ducts
Authors: Price Dorothy , Ortiz Evelina , Zaaijer Johanna J. P.
Published: February 2005

A study of sex differentiation of the Wolffian and Müllerian ducts of fetal guinea pigs was made by an organ culture method, and the morphogenetic changes of the ducts in vitro were compared with those in vivo. A total of 19 reproductive tracts were explanted from fetuses 29‐30 days old. The explants were cultured for nine days, with or without gonads. The Wolffian ducts degenerated in male tracts cultured without testes and in female tracts with or without ovaries, but they were maintained in male and female tracts cultured with one or two testes. The Müllerian ducts degenerated in all male tracts; in female tracts with or without ovaries they enlarged and coiled extensively and they were not inhibited when testes were cultured with the female tracts. It is concluded that in the guinea pig fetus at 29‐30 days of age, the Wolffian ducts of both sexes have become androgen‐dependent and that they are normally maintained in the male by testicular androgen. The Müllerian ducts of males were conditioned to degenerate before the time of explantation. The Müllerian ducts of females were not dependent upon ovarian hormone for their maintenance and development.
Androgen‐induced masculinization in the ovariectomized and hysterectomized guinea pig
Authors: Diamond Milton
Published: February 2005

Previously it had been demonstrated that daily injections of testosterone propionate (T.P.) will not induce male‐like mounting nor clitoral hypertrophy in pregnant guinea pigs to the extent it will in non‐pregnant females. In addition, administered progesterone had been shown effective producing a similar behavioral, but not somatic, “protection.” In an attempt to clarify the relationships of endogenous progesterone producing organs and this antiandrogen protective phenomenon the behavioral and somatic responses of females ovariectomized while pregnant and females hysterectomized (made pseudopregnant) while non‐pregnant were studied.

Guinea pigs were hysterectomized on the sixth day of their ovarian cycle and ovariectomized 60 days later. Additional groups of females were mated and then ovariectomized on the thirty‐sixth or forty‐sixth day of gestation. Groups of normal pregnant females, aborted females, and sham operated controls were also studied.

All groups received daily injections of T.P. starting on the eighteenth day of pregnancy and continuing for the duration of the experiment (116 days). With these androgen treatments masculinization or protection from maculinization was evaluated on the basis of periodic sex behavior tests and on the basis of daily inspection of the external genitalia.

The results indicate that protection from testosterone propionate‐induced virilization is offered by exogenously administered progesterone as well as by an endogenous progestagen‐producing structure such as the corpora lutea of the ovary in a hysterectomized female or the placenta in a pregnant animal. Some factor other than progesterone production is involved and the neural and somatic tissues exhibit different response thresholds.
Control of fertility in mammals by hormonal steroids
Authors: Pincus Gregory
Published: February 2005

A review is presented of the effects of steroids having hormone‐like activity upon the following reproductive processes in mammals: (a) spermatogenesis, (b) ovulation, (c) fertilization, (d) oviducal and uterine travel of the free ovum, and (e) blastocyst growth and implantation. Description is given of a number of natural and synthetic steroids which inhibit spermatogenesis and ovulation. By and large, estrogens are especially effective in the former and progestins in the latter, but aparently some species differences in response to potent substances do exist. Progestins have been shown to inhibit fertilization in experimental animals either through an effect on sperm travel or on sperm capacitation. The rapid expulsion of eggs from the fallopian tubes is accomplished by a variety of synthetic and natural estrogens upon administration in significant dosage in test animals. Decidualization and other processes related to implantation are also steroid labile.
Postnatal development of sensitivity to estrogen and androgen in male, female and psuedohermaphroditic guinea pigs
Authors: Goy Robert W. , Phoenix Charles H. , Meidinger Richard
Published: February 2005

Lordosis responses on the day of birth were measured in female pseudohermaphrodites, their male siblings, and control females and males. All subjects displayed lordosis. Differences in average duration of the response were not significant.

Relationships between exogenous estrogen and display of lordosis at later ages were studied in gonadectomized subjects. At seven days, estrogen did not induce lordosis in any subject. All normal females displayed lordosis at 21, 35, 60, and 90 days, and estrogen‐sensitivity increased steadily. Pseudohermaphrodites failed to respond to hormones until 35 days, and responses were infrequent and abbreviated. Age at time of ovariectomy did not influence performance of pseudohermaphrodites. Males showed lowest responsiveness to estrogen over all ages.

Pseudohermaphrodites resembled the male in postnatal responsiveness to androgen. Although postnatal testosterone induced mounting behavior in normal females, pseudohermaphrodites, like males, displayed more mounting and mounted at earlier ages.

Results suggest that prenatal androgen has not impaired the neural mechanism for lordosis at birth. Rather it acts to alter, during the fetal stage, the mechanism which normally directs the development of estrogen‐sensitivity of the neural mechanism in the genetic female. Additionally, prenatal androgen lowers the hormonal threshold for mounting behavior.
Analysis of histophysiologic responses of the rat hypophysis to androgen treatment
Authors: Bogdanove E. M.
Published: February 2005

The concentrations of LH and FSH were measured in the blood and adenohypophyses of castrated male rats exposed to high levels of testosterone propionate for 1 to 18 weeks. In intact male and female rats, similarly treated for 1 to 5 weeks, blood levels could not be measured but pituitary hormone levels were. Histological study of the pituitary gonadotrophic cells of all groups revealed a striking correlation between their regression, in response to androgen treatment, and the decline in pituitary LH stores. No light‐microscopic correlate of the marked, progressive increase in pituitary FSH concentration was detected. Thus, when the pituitary FSH:LH ratio had increased 90 fold, all gonadotrophs appeared inactive.

Although these studies failed to reveal the specific cellular source(s) of FSH and LH, they did clarify several aspects of the dynamics of the pituitary secretory responses to orchidectomy and androgen treatment. In the light of this information, the suggestion is made that the greatest dichotomy between pituitary FSH and LH stores is not coincident with — and probably occurs later than — that between LH and FSH secretion. Such asynchrony between the various phases of the FSH and LH secretory responses to these treatments (castration and/or androgen administration), may explain several seeming discrepancies among earlier reports on this subject.
Effect of a single dose of anti‐LH‐serum at proestrus on the rat estrous cycle
Authors: Schwartz Neena B. , Gold Jay J.
Published: February 2005

Previous studies have shown that pentobarbital administration at 2 p.m. of proestrus in the rat blocks ovulation and the drop in pituitary LH content normally seen at estrus; these data were interpreted as indicating that the drug acted by blocking LH release. Signs of prolongation of estrogen secretion were seen in these rats and, in the absence of further treatment, ovulation occurred 24 hours later. In the present study a single dose of anti‐ovine‐LH‐serum administered at 1 p.m. of proestrus also blocked ovulation, but did not prevent the drop in pituitary content on the moring of “estrus.” Therefore, one may conclude that this blockade was the result of preventing the peripheral effects of LH on the ovary. The antiserum blockade did not produce prolongation of estrogen secretion and no rat ovulated within the next four days. During this time pituitary LH content was normal, as were ovarian and uterine weight, although large follicles, rather than recent corpora lutea, were seen in the ovary. Six rats were followed until the next vaginal cornification (by 6 days); only three of the six had ovulated by day seven. The contrast between the sequelae of pentobarbital and antiserum blockade is interpreted in the light of a new theory of regulation of reproductive cyclicity in the rat.
Effects of beef insulin upon the granulation of beta cells in cultures of pancreases of fetal rats from diabetic mothers
Authors: Erlandsen Stanley L. , Wells Lemen J. , Lazarow Arnold
Published: February 2005

Portions of pancreases were removed from nineteen and one‐half day fetuses from diabetic and nondiabetic rats. These explants were grown for four days in organ culture by the watch glass method.

Four types of culture media were used: standard medium containing 165 mg of glucose per 100 ml; similar standard medium supplemented with 0.70 to 2.20 mU per ml of insulin (beef); high glucose medium containing 1050 mg of glucose per 100 ml; similar high glucose medium supplemented with 0.65 to 2.00 mU per ml of insulin (beef).

In cultures of pancreases grown on standard media both with and without added insulin, there were large increases in the number of granulated beta cells.

In cultures of pancreases of fetuses from diabetic rats, which were grown on high glucose medium, the high level of glucose maintained the cultures in a simulated diabetic environment in which few granulated beta cells appeared. Conversely, when the cultures of fetuses from diabetic rats were grown on high glucose medium with added insulin, there was an increase in the number of granulated beta cells.

These observations suggest that the insulin level in the culture medium influences the granulation of the beta cell.
The effects of ovarian hormones on uterine phosphatases of the rhesus monkey (Macaca Mulatta)
Authors: Manning John P. , Hisaw Frederick L. , Steinetz Bernard G. , Kroc Robert L.
Published: February 2005

Endometrial acid and alkaline phosphatases were studied histochemically in rhesus monkeys treated with various combinations of estrogen (E, 17β‐estradiol and/or estriol), progesterone (P) and relaxin (R) or a low potent relaxin control preparation (NRF). In the cells of the uterine glands of the E‐treated animal, the apical cytoplasm showed intense activity of both phosphatases. This estrogenic response was depressed in the stratum functionale by P and in the stratum basale by PR. With E, acid phosphatase‐staining granules appeared in scattered stromal cells with eccentric nuclei. Addition of P or PR increased the number of acid phosphatase positive stromal cells, especially in the stratum functionale. With the exception of the sinus‐like channels and superficial vessels of the stratum functionale of monkeys treated with ER and EPR, all endothelium of capillary and precapillary vessels was rich in alkaline phosphatase activity. Thus, acid alkaline phosphatases appear to be metabolically important components of the endometrium which undergo cyclic variation and reflect specific influences of the ovarian hormones; estrogens, progesterone and relaxin. The implications to human menstrual physiology are discussed.
The recurrent branch of the anterior cerebral artery
Authors: Ahmed D. S. , Ahmed R. H.
Published: February 2005

The recurrent branch of the anterior cerebral artery is of considerable applied importance. The extracerebral course of the vessel has been studied in dissection of 12 brains. Numerous variations in the course of the vessel were found and these have been presented.
Reconstruction of the human atrioventricular node
Authors: Truex Raymond Carl , Smythe Martha Q.
Published: February 2005

The right atrioventricular junction and A‐V node area in each of five human hearts was studied histologically in serial sections. The A‐V node of a 54‐year old female was reconstructed in four colors to provide a three‐dimensional model of cardiac relationships, blood supply, and nodal configuration. The nodal fibers demonstrated two laminations. A superficial layer was composed of longitudinally oriented fibers, whereas a deeper layer was composed of oblique and transversely directed fibers. The atrioventricular bundle fibers were always continuous with nodal fibers of the deeper portion of the A‐V node. Atrionodal fiber junctions occur along the superior, endocardial and inferior borders of the A‐V node and impart to these surfaces a spiked appearance. The potential significance of A‐V node structure to atrial cardiac conduction is presented.
Asymmetrical distribution of aortic nerve fibers in the pig
Authors: Prakash Prem , Safanie A. H.
Published: February 2005

The innervation of the aortic arch and associated arterial trunks was investigated in the pig by gross dissection, by microscopic examination of normal arterial walls, and by observation of degenerative changes following selective surgical interruption of right and left cervical vagi. It is concluded that the aortic depressor fibers of the pig are organized unilaterally, being distributed by the left vagus to arterial walls, and by observation of degenerative changes following selective surgical with the absence of a dissectable right aortic nerve, there was no histological evidence of sensory innervation in the walls of the brachiocephalic, right subclavian, bicarotid or right common carotid artery. The majority of depressor endings were located in the ventral wall of the aortic arch in a band extending between the origin of the left subclavian artery and the aortic attachment of the ligamentum arteriosum. A few were present in the dorsal wall of the aortic arch and the ventral walls of the pulmonary trunk and ligamentum arteriosum. The depressor fibers were thick, heavily myelinated, varicose, extensively branched and associated with numerous terminal and intercalated neurofibrillar corpuscles. The only epithelioid body observed was a poorly innervated, rudimentary paraganglion in the interval between the aortic arch, the pulmonary artery and the ligamentum arteriosum.
Modification of the endoplasmic reticulum in some mammalian oocytes
Authors: Szollosi Daniel
Published: February 2005

Oocytes of the hamster, rat, Mongolian gerbil and squirrel monkey demonstrate an unusual “twin” or multilaminated arrangement of the rough endoplasmic reticulum. Two or more cisternae appose laterally apparently after the ribosomes vanish from the adjacent surfaces. A central electron dense leaflet, composed of filamentous components can be discerned between the apposed surfaces. Between two cisternae of the membrane complex found in hamster oocytes, narrow connecting pillars or walls also develop. The nuclear envelope frequently represents one cisternal element in the membrane complex, at which place nuclear pores are lacking. In rat oocytes the endoplasmic reticulum cisternae take on either a concentric form, apparently by end‐to‐end fusion of “twin” cisternal membranes, or form a spiral by several turns of the same cisternum. No functional role could be suggested for the observed specilization of the endoplasmic reticulum.
A method for preparing brain casts
Authors: Welker W. I.
Published: February 2005

Permanent molds and casts of properly perfused formalin‐fixed whole brain specimens can be prepared in a manner that faithfully reproduces their shape, size, and surface morphological features. The method involves several steps: (a) removal of surface vessels or arachnoid tissue from fissural margins; (b) preparation of a plaster casing with a cavity of a size and shape which will accommodate both the elastic impression material and the portion of the brain to be cast; (c) pouring a silicone rubber‐catalyst mixture into this cavity in two stages, to produce first a lining, and then a rubber pool into which the brain is immersed; (d) removing the brain from the mold; (e) pouring an acrylic‐catalyst mixture into the hardened rubber mold and allowing it to polymerize to form a brain cast. Both mold and cast are durable, and repeated casting from a given mold can be carried out. Such brain casts provide a permanent record of three dimensional characteristics, as well as certain external morphological features which are otherwise irretrievably lost in a brain specimen that is to undergo histological processing, sectioning, staining, and mounting. The educational value of a comparative collection of such brain casts is inestimable.
A method for intracardial injections on rats
Authors: Rönning Olli , Isotupa Kauko
Published: February 2005

A method for applicating liquid material into the circulation of rats via the heart is described and the applicability is exemplified in some illustrations.
The ascending branch of Mauthner's axon in xenopus: Its possible role in startle reflexes
Authors: Hibbard Emerson
Published: February 2005

A major branch of Mauthner's (M‐) axon has been found in larvae of Xenopus laevis (Daudin). After giving off an inhibitory collateral toward the contralateral M‐cell, the branch continues forward to the preoptic nucleus of the forebrain. Following stimulation of the M‐cell, the function of the ascending branch of its axon may be to elicit startle responses corresponding to the defensive hypothalamic responses of higher vertebrates.
Effect of steroid hormones on biochemical characteristics of blastocysts in ovariectomized rabbits
Authors: Sugawara S. , Hafez E. S. E.
Published: February 2005

Groups of nulliparous pregnant rabbits were bilaterally ovariectomized on the third, fifth, sixth or seventh days of gestation; some groups were then treated daily with 40 mg of progesterone alone or with 4 mg progesterone alone or in combination with estradiol at a ratio of 1:400 or 1:4000. Animals ovariectomized 3 days post coitum (p.c.) were autopsied four days later; those ovariectomized five, six, or seven days p.c. were autopsied 24 hours later. The number of viable blastocysts per doe was greatly decreased following ovariectomy; however, the number was increased by treatment with progesterone alone or in combination with estradiol (1:400 or 1:4000). The weight of blastocyst and embryonic matter (trophoblast and embryonic disc), and the volume of blastocoelic fluid in the blastocyst at six or seven days p.c. were neither affected by ovariectomy nor by injection of 4 mg of progesterone. The weight of the blastocysts was significantly reduced when ovariectomy was performed seven days p.c. The concentration of the biochemical compounds in the blastocoelic fluid was not altered by ovariectomy at five or seven days p.c. In contrast, the concentration of glucose, lactic acid, protein N and nonprotein in the blastocyst was greatly lowered by ovariectomy at six days p.c., being partly alleviated by daily injections of progesterone, alone or in combination with estradiol. Ovariectomy at three days p.c. was no more detrimental than later ovariectomy if steroids were administrated.
Distribution of sperm in male rabbits after various ejaculation frequencies
Authors: Kirton K. T. , Desjardins C. , Hafs H. D.
Published: February 2005

Twenty‐five mature rabbits were assigned in groups of five to be ejaculated at one of the following frequencies for a period of six weeks: Sexual rest (SR), one ejaculation on Friday (1 × F), four ejaculations on Friday (4 × F), one ejaculation daily Monday through Saturday (1 × M–S), and two ejaculations Monday, Wednesday, and Friday (2 × MWF). Upon slaughter after SR, the average distributions of sperm in the capita‐corpora epididymides, caudae epididymides, and ductus deferentia were 184, 1,028, and 86 × 106, respectively.

Ejaculation at each frequency significantly reduced the numbers of sperm found in the caudae epididymides, but neither weights of nor sperm numbers in the capitacorpora epididymides were affected by ejaculation frequency. While 79 ± 3% of extragonadal sperm were found in the caudae epididymides after SR, only 27 ± 5% were found there after 4 × F. This depletion of sperm represents 64% of those considered available for ejaculation. The data indicate that the ductus deferentia and ampullae of rabbits contain insufficient sperm to account for those normally found in a single ejaculum, and that the caudae epididymides are the immediate sources of most ejaculated sperm. The average calculated daily sperm production (82 × 106) was not affected by ejaculation frequency (P > 0.10).
Hyperostosis at the mandibular notch: Report of a case
Authors: Vidić Branislav
Published: February 2005

A case of hyperostosis at the mandibular notch, on the right side, is recorded in a male cadaver, about 65 years of age. The shape of this exostosis and its relationship to the surrounding bones were studied in fixed and in various positions of movement of the mandible, as well as the degree of opening and closing of the mouth. The angle of the mandible, the coronoid and condylar processes, and the ramus were measured on both sides. Particular attention was given to the measurement of the exostosis. The morphological and clinical significance of the anomaly are discussed. A review of the literature indicates that this is an extremely rare type of exostosis of the mandible.
Histochemical study of ribonucleoproteins and mucopolysaccharides in developing bone of normal and tetracycline‐treated chick embryos
Authors: Rolle Gloria K.
Published: February 2005

The histochemical localization of ribonucleoprotein and mucopolysaccharide components in the developing femurs of normal and tetracycline‐treated chick embryos has been described. Tetracycline administration did not appear to affect the formation or character of the fibrous components involved in bone formation, or RNA production. Osteoid was laid down normally but calcification was markedly delayed. The depolymerization of the osteoid, as indicated by metachromasia and PAS staining, which is normally associated with the onset of calcification, was correspondingly delayed. The mucopolysaccharide content of the cartilage model was unchanged by the drug except in the hypertrophic zone. Here an abnormal depolymerization of the matrix occurred gradually, beginning in small areas and progressing to include all the matrix between small groups of cells. Calcification of these regions then took place.
Alpharadiographic and histological observations on the skeletal effects of hypervitaminoses A and D in the rat
Authors: Bélanger Leonard F. , Clark Irwin
Published: February 2005

Male Holtzman rats were fed large doses of vitamin A, D or A and D for 43 days. Sections of the tibia demineralized in EDTA were submitted to alpharadiography or stained by a variety of procedures, including mucopolysaccharide histochemistry. The results were as follows:

In hypervitaminosis D, slightly increased periosteal apposition of normal bone; greatly increased maturation of osteocytes with lacunar enlargement and confluence, interstitial metachromasia and loss of density (osteocytic osteolysis).

In hypervitaminosis A, large growth of abnormally stained cancellous bone at periosteum and stimulation of osteolysis in new and old bone.

In combined A and D hypervitaminoses, the peripheral apposition rate exceeded that induced by vitamin A or vitamin D alone. The new bone appeared fragile and this combined with increased osteolysis was responsible for a number of spontaneous fractures.
Fine structure of the posterior subclavian ganglion of the newt Triturus
Authors: Lentz Thomas L.
Published: February 2005

The posterior subclavian ganglion of the newt Triturus viridescens consists of a central zone of adrenal or interrenal cells and an outer cortex of chromaffin cells and sympathetic ganglion cells. Interrenal cells contain abundant large clear vacuoles in the cytoplasm and mitochondria with tubular cristae. Two types of chromaffin cells were observed: cells containing opaque granules, 1500 Å in diameter (norepinephrine), and cells containing moderately dense granules, 2600 Å in diameter (epinephrine). Both types of granules are present in a few cells. Sympathetic ganglion cells and their efferent nerves contain vesicles, 750 Å in diameter, with dense cores. Small unmyelinated nerves are located between chromaffin cells or between ganglion cells and their satellite sheaths. In synaptic regions, spherical or oval clear vesicles are abundant. Large bundles of a few myelinated nerves and many small unmyelinated nerves occur between the cellular elements. Axons are enveloped by Schwann cells and the large nerve bundles are loosely enclosed by a connective tissue sheath (endoneurium). Melanophores or pigment cells and connective tissue elements occur in the cortex of the gland.
The aorticopulmonary artery of the cat — its location and postnatal closure
Authors: Hughes Trevor
Published: February 2005

This paper describes the position and time of postnatal closure of a vessel from the pulmonary artery to the aorticopulmonary glomus (carotid body‐like) tissue. Nine prenatal and eight postnatal kittens (killed at 12 hours, and 8, 12, 16, 30, 42, 60 and 90 days) and 50 adult cats were examined. The vessel arose from the root of the right pulmonary artery and had ascending and descending branches. The latter supplied the aorticopulmonary glomus tissue and mingled with vessels arising from the root of the coronary arteries — usually the left. In two prenatal cats an actual anastomosis was demonstrated. There was no change in the intramural part of the branch of the pulmonary artery in kittens less than 16 days old. The vessel was partly closed by cellular proliferation by the sixteenth day and was almost certainly occluded by the forty‐second day. It was not patent in any animal more than 42 days of age. In the adult cat, the aorticopulmonary glomus tissue was less cellular than in the fetus. It is suggested that the communication between the branch from the right pulmonary artery and the coronary arteries through chemoreceptor tissue may have functional significance.