bluuebunny/crossref_metadata_2025 huggingface dataset:
Scanning electron microscopic study of the sacculus and lagena in several deep‐sea fishes
Authors: Popper Arthur N.
Published: February 2005

The ultrastructure of the sacculus and lagena, two otolithic organs involved in audition, was studied in seven species of bathypelagic and mesopelagic fishes representing a taxonomically diverse sampling of Division‐III teleost fishes. The saccular macula in each species had hair cells oriented in four directions, with cells on the rostral part of the macula oriented anteriorly and posteriorly, and those on the caudal end of the macula oriented dorsally and ventrally. The most significant variation from this pattern was in a Gadiform fish, Bregmaceros sp., which also had additional groups of horizontally oriented cells on the posterior end of the macula. The lagenar macula in each species had very similar hair cell orientation patterns, there being dorsally oriented cells on the anterior side of the macula and ventrally oriented cells on the posterior side. The only exception to this pattern was in Ectreposebastes, in which the two groups of cells were oriented towards one another.

Significantly, the predominant ciliary bundles on the sensory hair cells of the saccular maculae, and to a slightly lesser degree on the lagenar maculae, were quite similar in almost all species. The bundles had a single long kinocilium and graded stereocilia, the longest of which were almost as long as the kinocilium. This pattern is far less frequently found in shallow water fishes.

These data further demonstrate that the hair cells oriented in four directions on the saccular macula may be ubiquitous among all teleost fishes other than the Ostariophysi. The data also lead to the suggestion that the elongate ciliary bundle may be adaptive to certain features of life in deep water.
Mouse uterine glands during the peri‐implantation period: Fine structure
Authors: Given Randall L. , Enders Allen C.
Published: February 2005

Mouse uterine glands, obtained during the peri‐implantation period of pregnancy, were investigated using light and electron microscopy. From day 4 to day 6 of pregnancy, there was a progressive luminal dilation and an accumulation of dense homogeneous material in the gland lumina. Although numerous large electron‐lucent vesicles were present in the apical portion of the glandular cells on day 4, their number decreased by days 5 and 6 of pregnancy. Dense granules were present along the apical border of many glandular cells on day 6. In addition, there was an increase in the number and more orderly arrangement of RER cisternae by day 6 of pregnancy. Cytochemical studies on days 4, 5, and 6 of pregnancy, using the periodic acid‐thiocarbohydrazide‐silver proteinate method for the ultrastructural localization of carbohydrate material, showed specific staining of the multivesicular bodies and the saccules of the concave surface of the Golgi complex, but not the dilated saccules of the convex surface. Specific staining was also observed over both the luminal material and apical granules present on day 6 of pregnancy.

The cytochemical evidence suggests that the secretory product of the uterine glands has carbohydrate components and that carbohydrate material accumulates in the Golgi complex. In addition, the morphological changes observed imply increased secretory activity of the uterine glands during the peri‐implantation period. Thus, the uterine glands must be considered an important source of uterine fluid components during the peri‐implantation period.
Ultrastructural studies on spermatogenesis in a sex‐ratio‐mutant strain of Drosophila simulans
Authors: Ramamurthy Gollu , Alfert Max , Stern Curt
Published: February 2005

The aberrant sex‐ratio mutation in D. simulans used for this study is a temperature‐sensitive autosomal recessive. Homozygous males raised at 16°C produce about 2% in F1, but those raised at 26°C, have a normal sex ratio. Ultrastructural studies of spermatogenesis have revealed many anomalies in the germ cells of flies raised at 16°C, but the same flies raised at 26°C had few anomalies. The earliest spermatogenic stage with noticeable abnormalities was the primary spermatocyte. In later stages there were pronounced abnormalities in nucleoli, chromatin condensation, nuclear shape, Golgi complex, acrosome, and microtubules. There is asynchronous differentiation of spermatids within a bundle. Some of the abnormalities encountered are disorganization or loss of microtubules of the axoneme, degenerating nebenkern derivatives, and increased numbers of lysosomes, multilamellate bodies, and multivesicular bodies. At the lower temperature, more than half of the sperm within the same bundle were found in different stages of degeneration. Genetic analysis suggests that the sex‐ratio gene causes abnormalities and degeneration of most of the Y‐bearing sperm. However, counts of abnormal sperm at the ultrastructural level indicate that some X‐bearing sperm must also undergo degeneration. These observations show that the sex‐ratio gene is of variable penetrance at different temperatures in the primary spermatocyte and of differential penetrance in X‐ and Y‐bearing sperm.
Immunohistochemical identification of immunoglobulin A on ultrathin tissue sections
Authors: Rodning Charles B. , Erlandsen Stanley L. , Wilson I. Dodd
Published: February 2005

Antigenic determinants of the heavy chain of immunoglobulin A (IgA) were identified within immunocytes by immunohistochemical techniques applied to ultrathin sections of rat ileal mucosa embedded in epoxy resin. Successful localization of IgA depended upon the utilization of chemical fixatives containing paraformaldehyde or physical fixation employing a freeze‐drying technique. Partial removal of the epoxy resin from the ultrathin tissue section with metallic alkoxide solutions or pretreatment with H2O2 was essential prior to the sequential application of the immunological reagents. IgA was associated with the rough endoplasmic reticulum (RER) and nuclear regions of immunocytes. These results are similar to those of other investigators employing immunochemical localization before embedment.
Neonatal development of circadian rhythm in “synaptic” ribbon numbers in the rat pinealocyte
Authors: King Thomas S. , Dougherty William J.
Published: February 2005

Populations of “synaptic” ribbons (SR) in pinealocytes of the rat pineal gland at various ages from the neonatal period through early adulthood were analyzed morphometrically. Diurnal and nocturnal numbers of SR were small on day one but had increased dramatically by the end of the first week and beginning of the second week. By day 10, numbers of SR had peaked. Thereafter nocturnal numbers of SR demonstrated no significant increases or decreases. However, between days 10 and 19, diurnal numbers of SR decreased precipitously, appearing to have leveled off at the onset of puberty to levels observed in adults. SR were never scarce or absent in any age group studied.

The neonatal appearance of large numbers of SR coincides developmentally with the initial sympathetic innervation of pineal parenchyma. Circadian rhythm in numbers of SR begins shortly thereafter. It is suggested (1) that circadian rhythm in numbers of SR is initiated and regulated or modified by sympathetic innervation of pinealocytes containing SR, and (2) that SR formation may be related to the intracellular flow of membrane relative to the transport and release of specific pineal products.
Observations on the hypothalamo‐hypophyseal portal vasculature in the developing human fetus
Authors: Thliveris James A. , Currie R. William
Published: February 2005

Human fetuses, 11.5 to 16.8 weeks' gestational age, were perfused with silicone rubber compound to study the hypothalamo‐hypophyseal portal system. Impregnated vessels were observed throughout the median eminence, infundibular stalk, pars tuberalis and both lobes of the pituitary gland in all specimens. The data suggest that an intact portal system for the transport of hypothalamic releasing factors to the pituitary gland is established as early as 11.5 weeks' gestation.
Transplantation of brain tissue in the brain of rat. II. Growth characteristics of neocortical transplants in hosts of different ages
Authors: Hallas Brian H. , Das Gopal D. , Das Kunda G.
Published: February 2005

In this study the growth of neural transplants was analyzed in relation to the age of the host animals and the site of transplantation. The influence of these two host parameters on the growth of neural transplants with high growth potential (tissue from 15‐day‐old embryos) and low growth potential (tissue from 18‐day‐old embryos) was investigated. Neocortical neural tissues of constant volume, obtained from 15‐ and 18‐day‐old embryos, were tranplanted into the forebrain or cerebellum of 5‐, 10‐, 20‐, 25‐, 30‐, 35‐ and 180‐day‐old host animals and analyzed, quantitatively as well as qualitatively, 90 days after transplantation. The transplants grew larger in volume in the cerebellum than in the forebrain region of the hosts of all ages. In both sites, tissue from 15‐day‐old embryos yielded larger transplants than tissue from 18‐day‐old embryos. Transplants from 15‐day‐old embryos grew most extensively in 5‐day‐old host animals (33‐fold in the cerebellum, and 23‐fold in the forebrain region.) In older host animals it grew less extensively, and without much variation in size that could be attributed to the age of host animals. Tissue from 18‐day‐old embryos grew little, regardless of site of transplantation or age of host. Apparently the age of the host animals and the site of transplantation had greater influence on the growth of the neural transplants with high growth potential than on those with low growth potential. Histologically, the neural transplants in all cases contained normal‐looking and fully differentiated neurons and were anatomically integrated with the host brain.
Fine structure of the surfaces of the epithelium and mesenchyme of the newt limb regenerate, separated in salt solution: 14 to 25 days
Authors: Jasch Laura G.
Published: February 2005

Forelimbs of the newt Notophthalmus (Triturus) viridescens were amputated at the wrist, and at 14 to 25 days, the new limb regenerates were removed by a razor‐blade cut. After incubation of the isolated regenerates in a medium containing only inorganic salts, the epithelium was removed easily from the underlying mesenchyme. The surfaces separated in the salt solution were examined using scanning and transmission electron microscopy to evaluate the completeness of the separation and the extent of tissue damage near the plane of separation. Rarely was an epithelial cell found clinging to the mesenchymal surface, supporting previous light microscopic observations. The most apparent morphological damage was sustained by the basal epithelial cell surfaces, which exhibited blebbing; the formation of vacant vesicles within the cytoplasm near the newly exposed plasma membranes; the structural disruption of some organelles; and the tearing away of fragments of the basal epithelial cell plasma membranes, which remained adherent to the mesenchymal surface during separation procedure. Examination of the structure of the epithelialmesenchymal interface of intact regenerates showed that the plane of epithelialmesenchymal separation was, for the most part, between the basal epithelial cell membrane and its substrate, an extracellular material which remained at the mesenchymal surface after separation. This substrate was in the form of an extracellular material closely adherent to the basal epithelial cell membrane at the distal tips of the regenerates; a developing basal lamina at the periphery of regenerates undergoing blastema accumulation; or a mature basal lamina at the base of digit stage regenerates. The usefulness of these separated tissues for future experimentation and the evaluation of the nature of the epithelial substratum throughout the course of limb regeneration are discussed.
Differences in the development of jejunum and ileum as observed in fetal rat intestinal isografts. Possible implications related to the villus size gradient
Authors: Jolma Vladimira M. , Kendall Kevin , Koldovský Otakar
Published: February 2005

Previous studies have shown that villus size in the small intestine decreases from the duodenum toward the ileum. Villus‐enlarging and villus‐reducing factors have been found in the gastric, pancreatic, and duodenal secretions, and in bile (Altmann and Leblond, ′70; Altmann, ′74). We here explore the role of intrinsic factors present in the individual sections of the small intestine by following the development of villus height in fetal (21‐day old) jejunal and ileal segments implanted under the kidney capsule of syngeneic adult rats. Twenty‐eight and 45 days after implantation, the jejunal villi contained significantly more columnar epithelial cells than did the ileal villi, but the jejunoileal gradient was even greater in small intestine of corresponding ages, developing in situ. Our experiments, thus, show that the jejunoileal gradient is already programmed in rats 1 day before birth, while other factors contribute postnatally to regulation of its magnitude.
The urethral sphincter muscle in the male
Authors: Oelrich Thomas M.
Published: February 2005

The male urethral sphincter is a striated muscle in contact with the urethra from the base of the bladder to the perineal membrane. The individual muscle fibers are 25 to 30% smaller than fibers of associated muscles and are embedded in connective tissue which obscures the visibility of the whole muscle.

The muscle primordium is laid down around the urethra prior to the development of the prostate. Subsequently, the prostate develops as a diverticulum of the urethra and grows into the developing sphincter, thinning the overlying musculature. With the onset of puberty, accelerated growth of the prostate displaces the sphincter, with atrophy of the overlying muscle, resulting in what may appear to be isolated segments of the sphincter muscle distributed around the prostate. The prostate overgrows the anterior portion of the urethra and the associated sphincter muscle.

There is no distinct superior fascia of the so‐called urogenital diaphragm separating the sphincter muscle from the prostate. The fascia of the sphincter muscle is inseparable from the prostatic sheath, is oriented vertically, and passes through the urogenital hiatus to unite with the fascia of the pudendal canals at the isochiopubic rami. Thus, the sphincter muscle is a component of a bladder‐urethra‐prostate‐sphincter unit which lies within the pelvis, in the urogenital hiatus, and rests upon the perineal membrane. The concept of a urogenital diaphragm is not borne out by this study.
Morphological and cytochemical alterations of the Golgi apparatus and GERL in rat parotid acinar cells during ethionine intoxication and recovery
Authors: Oliver Constance , Auth Regina E. , Hand Arthur R.
Published: February 2005

The present electron microscopic cytochemical investigation was undertaken to characterize the alterations in the Golgi apparatus and GERL of rat parotid acinar cells during ethionine intoxication and recovery. Although the Golgi apparatus and GERL were reduced in size, and some broadening of the Golgi saccules occurred as the result of ethionine treatment, the relative localization of thiamine pyrophosphatase (TPPase) activity in the Golgi saccules, and acid phosphatase activity (AcPase) in GERL, remained unchanged. Shortly after ethionine treatment was stopped, a dramatic redistribution of enzyme activities was noted. Within the first 24 hours of recovery, the Golgi apparatus began to enlarge, and the content of secretory granules increased. By day 3 of recovery, cisternae morphologically identifiable as GERL and forming secretory granules possessed TPPase activity, while AcPase activity was virtually undetectable. After seven days of recovery, the Golgi apparatus and GERL appeared both morphologically and cytochemically normal. The enzyme modulation observed during recovery may be correlated with increased secretory granule production. Furthermore, the presence of TPPase activity in GERL and forming secretory granules lends support to the suggestion that GERL may be derived from the trans Golgi saccule.
Cytodifferentiation of the rat paneth cell: An immunocytochemical investigation in suckling and weanling animals
Authors: Lopez‐Lewellyn Jeannette , Erlandsen Stanley L.
Published: February 2005

The cytodifferentiation of the intestinal Paneth cell was investigated in 2‐ to 50‐day‐old rats by evaluating the phenotypic expression of bacteriolytic lysozyme. Samples of duodenum, jejunum, and ileum were exposed to anti‐lysozyme antiserum and treated by the periodic‐acid Schiff (PAS) technique for the demonstration of carbohydrate moieties. The distribution of the Paneth cell population was then assessed.

At days 3‐6, Paneth cells were present in ≤ 1% of intestinal crypts and exhibited (a) location in the bases of crypts, (b) apical granules positive for lysozyme, and (c) a slender truncated shape extending to the crypt lumen. By days 6‐8, Paneth cells had acquired their typical broad, truncated shape and prominent secretory apparatus. Between 1 and 7 weeks postpartum, the frequency of Paneth cellcontaining crypts in duodenum rose from 9% to 79%; in jejunum and ileum the frequency increased through the third week of life and stabilized at 77%–93% thereafter. At all ages, a rostro‐caudal gradient of crypts containing Paneth cells was observed, and greater numbers of paneth cells per crypt were seen caudally. In both suckling and weanling animals, two intermediate cell types were encountered. The first predominated at crypt bases through the fourth week of life and contained lysozyme‐positive supranuclear granules, concomitant with an apical aggregation of PAS‐positive material. The second type, identical to goblet cells in size and shape, predominated along the walls of intestinal crypts and at the bases of villi, and manifested both lysozyme‐positive granules and PAS‐positive mucigen droplets in the apical cytoplasm. This cell type appeared by day 12 and persisted through day 50.

The results of this study provide further evidence that Paneth cells differentiate from a subpopulation of multipotent stem cells residing at crypt bases. The observation of Paneth cell‐goblet cell transitional forms supports the view that these two cell types share a common lineage.
Differentiation of myoepithelial cells in the developing rat parotid gland
Authors: Redman Robert S. , Sweney Laura R. , McLaughlin Shirley T.
Published: February 2005

Parotid glands of rats were prepared for light and electron microscopy and for the histochemical demonstration of myofibrils and alkaline phosphatase (AkPase) activity. Through 18 days in utero, the epithelial cells of the developing gland remain relatively undifferentiated. At 20 days in utero, a few cells in the outer layer of the terminal buds and adjacent segments of ducts acquire a cilium, the initial indication that they are differentiating into myoepithelial cells (MEC). Up until the time of birth, the only additional characteristics of MEC that the outer cells develop are to flatten against the underlying cells, begin to send out processes, and produce a few dilated cisternae of rough endoplasmic reticulum. Myofibrils and AkPase activity are first detected at the light microscopic level at five days after birth, around both the developing acini and intercalated ducts. Progressive increases in AkPase activity and in the size and number of myofibrils continue until the acini and intercalated ducts are invested with well‐differentiated MEC at 15 days. Subsequently, as the acini undergo maturation during the weaning period (18‐25 days), the MEC cease to surround the acini and assume the adult pattern of investing only the intercalated ducts. The pattern of MEC differentiation in the parotid gland differs from those in the sublingual and submandibular glands of the rat in several important respects. They begin to differentiate last, yet mature almost as early as do the MEC of the sublingual gland; they begin to differentiate prior to, rather than simultaneously with, the secretory cells; and their distribution changes as the acinar cells become mature.
Cell turnover in the odontogenic organ of the rat incisor as visualized by graphic reconstructions following a single injection of 3H‐thymidine
Authors: Smith C. E.
Published: February 2005

Turnover of cells within the odontogenic organ was studied in three dimensions by preparing serial sections of incisors from young male rats killed at various times following a single intraperitoneal injection of 1 μCi/g body weight of 3H‐thymidine. Radioautographs showed that at 1 hour after injection labeled cells were present in all cell layers throughout the entire depth of the odontogenic organ. They were encountered frequently within the inner dental epithelium and stratum intermedium but appeared less abundant within the stellate reticulum and outer dental epithelium. With time, the frequency of labeled cells in each layer declined progressively, and more rapidly at the anterior and labial side of the odontogenic organ than toward its posterior and lingual side. Hence labeled cells were observed over the longest time interval in regions where cell layers were in closest proximity to the opening of the apical foramen, that is, near the apical and cervical loops. By 32 days after injection, numerous labeled cells could still be identified within the outer dental epithelium and stellate reticulum near the apical loop (bulbous part of the odontogenic organ) and the outer dental epithelium near the cervical loops (“U”‐shaped part of the odontogenic organ). These findings support the hypothesis that cells originate within the bulbous part of the odontogenic organ and migrate anteriorly through the “U”‐shaped and root sheath parts of the odontogenic organ during renewal of the incisor. It appears that individual stem cell compartments may be maintained for surface (outer/inner dental epithelium) and intermediate layers (stellate reticulum/stratum intermedium) in the odontogenic epithelium.
Effects of actinomycin D on dexamethasone induced hepatic glycogen accumulation: Morphological and biochemical observations
Authors: Margolis Ronald N. , Cardell Robert R.
Published: February 2005

Effects of inhibition of protein synthesis by actinomycin D (ACT) on the acute stimulation of hepatic gluconeogenesis and glucose‐6‐phosphatase (G6Pase) by the glucocorticoid, dexamethasone (DEX), in adrenalectomized (ADX) rats, were investigated using both morphological and biochemical means. Examination of ultra‐thin sections of liver in the electron microscope revealed that ACT, administered alone or with DEX, resulted in a failure of hepatic glycogen accumulation to occur. Smooth endoplasmic reticulum (SER) appeared similar to that of the ADX‐untreated animals, with occasional suggestions of increased amounts of membrane in ACT‐treated animals. G6Pase activity in homogenates was increased, as was activation of the enzyme under all experimental conditions, when compared with ADX‐untreated controls. The DEX‐induced increase in G6Pase activity in SER failed to occur to any appreciable extent in ACT‐treated animals. Plasma glucose levels increased slightly when ACT and DEX were present simultaneously.

It is suggested that ACT countered the inductive effects of DEX on hepatic glycogen synthesis, but only partially suppressed acute stimulation of gluconeogenesis. A possible superinduction of G6Pase enzyme synthesis through increased efficiency of translation of extant mRNA is discussed. It is proposed that ACT inhibited the formation of appropriate SER membranes and/or other components necessary for glycogen accumulation.
Immunocytochemistry of prolactin‐producing human pituitary adenomas
Authors: Duello T. M. , Halmi N. S.
Published: February 2005

Among 92 surgically removed pituitary adenomas immunostained for prolactin and growth hormone, 70 showed positive staining for prolactin. The majority of these (54) was associated with hyperprolactinemia leading to amenorrhea (and often galactorrhea) in women of reproductive age. Similar tumors, asymptomatic or conducive to disturbances of sexual function, were found in six hyperprolactinemic men. Among nine acromegalics, seven had immunostained lactotrophs associated with the somatotrophic adenomas cells, but only two of these had hyperprolactinemia. In all of the remaining tumors that had at least some immunoreactive lactotrophs, mild hyperprolactinemia had been present. This indicates that immunostaining of pituitary tumors for prolactin correlated well with elevated plasma prolactin levels, except in the case of mixed somatolactotrophic adenomas. The patterns of distribution of immunoreactive prolactin in adenoma cells are illustrated. Since only some of the prolactin‐producing adenomas stained with carmoisine–a dye that has been suggested as a marker for prolactin cells–immunocytochemistry is the method of choice for the identification of prolactin‐secreting adenomas.
Immunoreactive adrenocorticotropin in rat brain: A neuroanatomical study using antiserum generated against synthetic ACTH1–39
Authors: Joseph Shirley A.
Published: February 2005

In this study an antiserum generated against synthetic ACTH1–39 is used to provide a neuroanatomical map of ACTH‐immunoreactivity in rat brain. Groups of ACTH‐immunoreactive cell bodies were located in the basal hypothalamus, extending from the retrochiasmatic region to the mammillary nuclei. The fiber distribution indicates a broad innervation of structures in the hypothalamus, which include the medial preoptic region; bed nucleus of the anterior commissure and stria terminalis; perifornical region; periventricular stratum; and paraventricular, dorsomedial, arcuate, and mammillary nuclei. Fibers from the hypothalamus reach the amygdaloid nuclei directly in two separate bundles. A large dorsal ACTH‐immunoreactive bundle emerges from the anterior hypothalamic region, distributes to the periventricular thalamic nuclei, and continues more posteriorly to the midbrain periaquaductal gray. It is speculated that the cell bodies in the ventral tuberal region of the hypothalamus are responsible for the vast innervation of fibers to the forebrain, diencephalon, and brainstem.
Electromyography— dynamic gross anatomy: A review
Authors: Basmajian John V.
Published: February 2005

“Electromyography: Dynamic Gross Anatomy” is the first in a series of invited review articles by leaders in fields of current interest.

Students often ask if anything really “new” has been discovered in gross anatomy in the last fifty years. The answer is an unqualified “yes,” and electromyography probably has provided more of this new information than any other technique. Not since the pioneering work of Duchenne in 1867 has any one man contributed so much to our knowledge of the function of the musculoskeletal system as Dr. John V. Basmajian, Professor of Medicine and Associate in Anatomy at McMaster University and Director of Rehabilitation and Continuing Care Centres of Chedoke‐McMaster Hospital, Hamilton, Ontario, Canada. Since his initial publication in 1952, he has written over 200 scientific papers on electromyography. He is the author of Muscles Alive: Their Functions Revealed by Electromyography, now in its fourth edition, and the author or co‐author of numerous other books on gross anatomy, kinesiology, therapeutic exercise and clinical electro‐neurography.

In 1965, Dr. Basmajian was one of the founders of the International Society of Electromyographic Kinesiology (now the International Society of Electrophysiologic Kinesiology), and he served as its first president. In recognition of his many contributions to the discipline, ISEK dedicated its Sixth International Congress to him. Universally recognized as the undisputed leader in the field, Professor Basmajian is the ideal person to summarize the “state of the art” for the readers ofThe American Journal of Anatomy.
An electron microscopic study on the structural development of the neural lobe in the human fetus
Authors: Okado Nobuo , Yokota Norio
Published: February 2005

Structural development of the neural lobe of the hypophysis was studied by light and electron microscopy in five human fetuses ranging from 7.5 to 19 weeks of ovulation age.

Clusters of small clear vesicles were found occasionally in axon profiles in a fetus of 7.5 weeks. Granular vesicles in axon profiles first accumulated in a fetus of 8.5 weeks. Concurrently, fenestration of capillary walls and expansion of perivascular spaces were observed.

After 8.5 weeks, three type of vesicle‐containing axon profiles were found, which contained predominantly granular vesicles (GP), small clear vesicles (SP), and a mixed population of both granular and small clear vesicles (MX), respectively. Their numbers increased significantly during two periods, 7.5–8.5 weeks and 15.5–19 weeks. Ratios of GP, SP, and MX to the total number of the three types of axon were almost the same in all the fetuses studied, i.e., about 40%, 40%, and 20%, respectively.

Developmental changes in the diameter of granular vesicles were examined in GP, SP, and MX of each fetus. Apart from a few exceptions, the mean diameter of granular vesicles was larger in GP than in MX, which was in turn larger than in SP. The diameters increased with development and those in GP reached almost the same value as in the adult by 19 weeks.
Membrane‐bound glycoprotein in the alveolar cells of the caprine lung
Authors: Atwal Onkar S. , Brown Laurie M.
Published: February 2005

An ultramicroscopic analysis of caprine lung glycoproteins, designed to detect plasmalemma‐associated sulfoglycoprotein of alveolar type I and alveolar type II cells, was performed. High‐iron diamine staining demonstrated a layer containing sulfated glycoproteins at the apical plasmamembrane of alveolar type I cells and microvilli of alveolar type II cells. The cytoplasmic vesicles of the alveolar type I cell contained the reaction product on the inner leaflet of the vesicular unit membrane. The vesicles showed a variety of interactions with the apical plasma membrane. High‐iron diamine staining also demonstrated sulfogly‐coproteins in the cytoplasmic granules of the mast cells in the alveolar septum. The present study gives evidence that plasmalemma of the alveolar cells of the goat lung possesses exposed hyaluronic acid groups.
An electron microscopic study of implantation in the cow
Authors: Wathes D. Claire , Wooding F. B. P.
Published: February 2005

The paper describes the changes occuring in the uterine and chorionic epithelia of the cow between days 18 and 28 of gestation, before and during implantation. The irregular uterine epithelium of the non‐pregnant cow was simplified to a tall columnar epithelium before attachment began. Areas of attachment were first observed at day 20 in the region of the embryo. Such sites were characterized by the presence of pale uterine cells containing up to 8 nuclei (“giant cells”) which accounted for nearly 50% of the epithelial area by day 24. Fetal binucleate cells were found in contact with, and partly across, the microvillar junction at all stages examined, and the presence of granules characteristic of binucleate cells within the giant cells suggested that the fetal cells contributed to their formation. Many uterine epithelial cells underwent degenerative changes between 22 and 28 days, and residues equivalent to their pyknotic remnants were found at the microvillar junction and within the mononucleate chorion cells. By day 28 some of the giant cells appeared to be degenerating, and areas of low cuboidal epithelium were present. This epithelium resembled the type found in the mature placenta. There was evidence that binucleate cell migration continued at this time. Nevertheless, the definitive membrane in the mature bovine placenta is epitheliochorial.
Ultrastructural cytochemistry of complex carbohydrates of gastric epithelium in the guinea pig
Authors: Sato Akira , Spicer Samuel S.
Published: February 2005

Ultrastructural and complex‐carbohydrate cytochemical studies were carried out on guinea pig gastric mucosa to assess the histochemical properties of the secretions of different gastric epithelial cells and to investigate the differentiation, origin, and renewal of certain cell types. The observations disclosed heterogeneity or variability of the secretory granules within individual mucigenic cells and zymogen cells. The cytochemical methods also served in characterizing and distinguishing five cell types in the gastric glands, including the isthmus cell, a mucous cell considered comparable to the mucous neck cell, the chief cell, and forms transitional between the isthmus and mucous cells and the mucous and zymogenic cells. The several cell types differed widely in the cytochemical properties of the secretory granules and the apical plasmalemma, and each had a distinctive distribution in the gastric gland. Cytochemical staining observed here provided evidence on synthesis and intracellular metamorphosis of mucous droplets and on formation of glycocalyx.
Structural evidence for two different testicular types in teleost fishes
Authors: Grier H. J. , Linton J. R. , Leatherland J. F. , De Vlaming V. L.
Published: February 2005

Testicular structure in Salmoniformes, Perciformes, Cypriniformes, and Atheriniformes has been examined and reinterpreted on the basis of two different tubular types, distinguished from each other by the intratubular distribution of spermatogonia. In the salmoniform, perciform, and cypriniform teleosts studied, spermatogonia are distributed along the entire length of the testicular tubules. However, in the atheriniform teleosts spermatogonia are restricted to the distal end of the tubule. Sperm development in teleosts is cystic, cysts being comprised of Sertoli‐cell processes. In both testicular types described, Sertoli cells phagocytize spermatid residual bodies. Together witb the germ cells, they comprise the only intratubular cell types within the teleostean testis.

Boundary cells are located immediately outside of the tubule basement membrane. They do not form a complete layer over the tubule surface; therefore, interstitial Leydig cells and blood vessels may border directly upon the tubular basement membrane.
Serotonin and seasonal variation in the pancreatic structure of bats: Possible presence of serotonergic axons in the gland
Authors: Nunez Eladio A. , Gershon Perry , Gershon Michael D.
Published: February 2005

The serotonin concentration in the bat pancreas was determined at nine times during the year. Pancreatic ultrastructure was also examined. The pancreatic level of serotonin was uniform throughout the year except in late May, when it fell dramatically from a normal level of 3.14 ±.19 μgm/gm to 0.40 ± .05 μgm/gm. No seasonal changes in islet fine structure were found; however, the ultrastructure of exocrine cells was seen to be changed radically only in bats captured in late May. At this time, bats develop unusual cytoplasmic structures in the exocrine cells. These structures consist of membrane‐limited bodies containing long, straight, and parallel paracrystalline arrays of stacked membranes and round or pleomorphic osmiophilic granules. Depletion of serotonin with reserpine or parachlorophenylalanine, or incubation of pancreatic tissue with different concentrations of serotonin, failed to provoke the formation of these structures in exocrine cells of active bats. Administration of 3H‐5‐hydroxytryptophan to bats, or incubation of bat pancreas with 3H‐serotonin, failed to demonstrate a labeling of pancreatic exocrine cells. Incubation of the gland with 3H‐serotonin, however, led to intense labeling of a subset of pancreatic terminal axons. It is concluded that the natural fall in the concentration of serotonin in late May is not the cause of the formation of the paracrystalline structures in pancreatic exocrine cells. The specific pancreatic uptake mechanism for serotonin found by Kovary et al. ('80) is probably a property of pancreatic neurites; these neurites might be serotonergic.
Specific uptake of tritiated serotonin in the adult rat pancreas: Evidence for the presence of serotonergic fibers
Authors: Koevary Steven B. , McEvoy Robert C. , Azmitia Efrain C.
Published: February 2005

Fragments of adult rat pancreas were incubated in vitro with tritiated serotonin at concentrations from 10−8 to 10−7 M. The pancreas exhibited an uptake of serotonin which was saturable, with an uptake constant (Km) of 8.75 × 10−7 M, and a Vmax of 873 pmoles per gram. Specificity was determined by the addition of fluoxetine or norepinephrine to the reaction mixture, both at 10−5 M. Fluoxetine significantly reduced the 3H‐5HT uptake, whereas norepinephrine was without effect. Metergoline (10−6 M), a specific 5‐HT postsynaptic receptor blocker, similarly had no effect on the serotonin uptake in the pancreas. Radioautography of the fragments following uptake of tritiated serotonin (5 × 10−8 M) revealed silver‐ grain aggregates dispersed along blood vessels in the interstitial spaces of the exocrine and endocrine pancreas, areas known to be traversed by nerve fibers. There were no silver‐ grain aggregates over the exocrine or islet parenchymal cells. These data support the hypothesis that the pancreas is innervated by serotonergic fibers. Further evidence for this hypothesis was provided by a preliminary study demonstrating the presence of tryptophan hydroxylase in pancreatic homogenates. These serotonergic fibers may be involved in the regulation of pancreatic secretion.
Seasonal changes in prolactin and growth hormone cells in the hypophyses of white‐tailed deer (Odocoileus virginianus borealis) studied by light microscopic immunocytochemistry and radioimmunoassay
Authors: Schulte B. A. , Seal U. S. , Plotka E. D. , Verme L. J. , Ozoga J. J. , Parsons J. A.
Published: February 2005

Numerous investigators have shown a relationship between basal serum prolactin (PRL) levels and photoperiod in domestic ungulates, and we have shown recently that a similar seasonal baseline serum PRL profile exists in both sexes of a captive but free‐breeding population of white‐tailed deer. In order to localize and describe the distribution and possible seasonal changes of PRL and growth hormone (GH) cells in the adenohypophyses of deer, we have used antisera raised against ovine PRL and bovine GH and the unlabeled antibody enzyme technique, in conjunction with point counting morphometry. In addition, we have measured seasonal changes in pituitary PRL concentrations in this same population, using a heterologous application of a recently developed homologous radioimmunoassay (RIA) for ovine PRL. Our results show that GH and PRL cells comprise two morphologically separate and immunologically distinct populations. Growth hormone cells were distributed evenly throughout the gland, except in the zona tuberalis, and males had a slightly greater volume density of immunoreactive GH than females; however, there were no differences between sexes in the average size of these cells, and little seasonal change was observed in these cell populations. In contrast to GH cells, the volume density of PRL cells, the size of PRL cells, and the pituitary concentration of RIA‐measurable PRL all showed marked seasonal changes in deer of both sexes. These changes were well correlated with one another and with previously reported changes in basal serum levels (in these animals), in that they all reached zenith during midsummer, and nadir in midwinter. Our results demonstrate the necessity of reporting the time of year and latitude (to specify photoperiod) in studies concerning PRL cell physiology, particularly when dealing with any wild animal population.
Glomerular architectural changes after a two‐hour infusion of norepinephrine
Authors: Bulger Ruth Ellen , Cronin Robert E. , Dobyan Dennis C.
Published: February 2005

Alterations in glomerular architecture have been suggested to play a role in the pathogenesis of several models of acute renal failure. In this study, mongrel dogs were subjected to an intrarenal infusion of norepinephrine for 2 hours. Light microscopy and scanning and transmission electron microscopy were used to describe glomerular architecture 2 days after the initial norepinephrine infusion. In addition, scanning electron microscopy was used to quantitate the percentage of “abnormal areas” in glomerular capillary‐loop morphology in both norepinephrine‐infused kidneys and the contralateral control kidneys. Alterations in glomerular structure in these experiments appeared to be much less extensive than previously reported. A variable amount of glomerular pedical shape simplification was seen, which involved about 15% of the capillary loop Quantitative evaluation revealed abnormal morphology of 15.2% ± 0.6% of the glomerular capillary loop in the norepinephrine‐infused kidneys, compared to 2.9% ± 0.4 abnormal loop structure in the contralateral control kidneys (P <0.001). It is concluded that alterations in glomerular structure are not extensive in this model.
Coiled bodies in supraoptic nuclei of the rat hypothalamus during the postnatal period
Authors: Hervas J. P. , Villegas J. , Crespo D. , Lafarga M.
Published: February 2005

In electron microscopic studies of the supraoptic nuclei of the rat hypothalamus, structures identified as “coiled bodies” were found in magnocellular neurons. Although they could be seen elsewhere in mature neurosecretory cells, coiled bodies were commonly encountered in developing neurons during the postnatal period in both sexes. They appeared as distinctive nuclear inclusions consisting of round‐to‐oval networks of short electron‐dense strands embedded in a less dense, fibrillar matrix, and lacking a limiting membrane. In fine structure and stain‐affinity, they bore a resemblance to the fibrillar component of the nucleolus.

Coiled bodies were located either in close association with the nucleolus or free within the nucleoplasm, showing no specific relationships with the perinucleolar chromatin or with the nuclear envelope. Their origin and functional meaning is discussed in the light of recent ultrastructural and biochemical data on cellular differentiation and nucleolar behavior.
Osteogenesis and leukopoiesis within diffusion‐chamber implants of isolated bone marrow subpopulations
Authors: Budenz Richard W. , Bernard George W.
Published: February 2005

The developmental potential of isolated rabbit bone marrow cell populations was examined following autogeneous implantation into diffusion chambers. After 4 weeks, tbe implants were harvested and processed for light and electron microscopy. More total tissue was formed in abdominally implanted chambers than in corresponding femoral chambers. Two of the separated marrow cell populations produced significantly greater amounts of fibrous connective tissue, cartilage, and bone than did whole‐marrow controls. These two populations, which were defined by density gradients of 1.050–1.055 gm/cm3 and 1.064–1.067 gm/cm3, consistently produced a fibrous connective tissue nodule in which were found dispersed foci of hyaline cartilage and woven bone. The denser population was distinguished further by the presence of leukopoietic foci in several of the implant chambers. Cartilage foci were found predominantly towards the center of the tissue nodules, whereas bone was dominant towards the periphery. Blood vessels, osteoclasts, bone remodeling, and mature lamellar bone were found only in those chambers which had been penetrated by the host's vascular system. The results indicate that (1) normal marrow tissue contains two separate osteoprogenitor cell populations; (2) these two progenitor populations represent separate osteogenic and chondrogenic capabilities; (3) one of these populations possesses a leukopoietic as well as an osteogenic potential; and (4) a competent vascular system is essential for the remodelling of bone into mature bone organs.
Modes of protein and peptide uptake in the pineal gland of the Mongolian gerbil: An ultrastructural study
Authors: Welsh Marcia G. , Beitz Alvin J.
Published: February 2005

The possible existence of either a blood‐brain barrier or a CSF‐brain barrier was examined in the pineal gland of the Mongolian gerbil using the ultrastructural tracers, horseradish peroxidase (HRP) and microperoxidase (MP). The mechanism of protein and peptide transport within the pineal gland and its possible relationship to pineal concretions was also considered. Gerbils were injected with either MP or HRP intravenously (IV), or they received intraventricular (IVT) injections of HRP. The IV injections resulted in both MP and HRP movement through the endothelial cells of the gland by vesicular transport and by diffusion through the endothelial intercellular junctions. Following the IVT injections, the tracer was demonstrated in the subarachnoid space as well as in the glial cells associated with the periphery of the gland. In addition, after the IVT injections, rounded enlargements of the intercellular space that resembled canaliculi were filled with reaction product. In both cases (IVT and IV), the reaction product was localized to the perivascular space, to the glial cells and pinealocytes, and to the intercellular spaces. More importantly, there was specific localization of the tracers in the vacuolated pinealocytes and in the pineal concretions. The results of this study demonstrate several significant findings: (1) neither a blood‐brain barrier nor a CSF‐brain barrier exists in the pineal gland of the gerbil, (2) localization of the tracers in pineal concretions indicates a relationship between these structures and protein and peptide storage within the gland, and (3) the presence of the tracers within canaliculi after the IVT injections suggests a possible mode of secretion of pineal substances into the CSF.
Structure of the tight junctions of the human eccrine sweat gland
Authors: Briggman J. V. , Bank H. L. , Bigelow J. B. , Graves J. S. , Spicer S. S.
Published: February 2005

The human eccrine sweat gland contains two anatomically and functionally discrete segments: the secretory coil, which produces an isotonic or slightly hypertonic precursor fluid, and the coiled duct, which resorbs Na+ and Cl− to yield a hypotonic sweat. We examined the freeze‐fracture morphology of tight junctions from isolated secretory coil and coiled duct segments to assess indirectly the contribution of paracellular ion transport in secretion and resorption in the sweat gland. In the secretory coil, tight junctions of the intercellular canaliculus and main lumen consisted of approximately 9 and 6, closely spaced, parallel or anastomosing elements, respectively. Tight junctions of the coiled duct were similar in appearance to those at the main lumen of the secretory coil. In both the secretory coil and coiled duct, and average of 2 to 3, widely spaced junctional elements were usually observed basolateral to the closely spaced junctional elements in the region corresponding to the location of the zonula adherens in Epon sections. The complexity of the tight junctions of the secretory coil exceeded what we expected for an epithelium secreting an isosmotic fluid. The elaborate tight junctions of the coiled duct support other evidence for an intermediate to high transepithelial resistance.