bluuebunny/crossref_metadata_2025 huggingface dataset:
Multi-Institutional Randomized Phase II Trial of the Epothilone B Analog Ixabepilone (BMS-247550) With or Without Estramustine Phosphate in Patients With Progressive Castrate Metastatic Prostate Cancer
Authors: Galsky Matthew D. , Small Eric J. , Oh William K. , Chen Isan , Smith David C. , Colevas A. Dimitrios , Martone Lou , Curley Tracy , DeLaCruz Anthony , Scher Howard I. , Kelly W. Kevin
Published: February 2005

Purpose

To evaluate the antitumor activity and safety of the epothilone B analog, ixabepilone, with or without estramustine phosphate (EMP), in chemotherapy-naive patients with progressive castrate metastatic prostate cancer.

Patients and Methods

Patients were randomly assigned to receive ixabepilone (35 mg/m2) by intravenous infusion every 3 weeks with or without EMP 280 mg orally three times daily on days 1 to 5.

Results

Between December 2001 and October 2003, 92 patients were enrolled and randomly assigned to treatment with ixabepilone alone (45 patients) or in combination with EMP (47 patients). Grades 3 and 4 toxicities experienced by more than 5% of patients included neutropenia (22%), fatigue (9%), and neuropathy (13%) on the ixabepilone arm, and neutropenia (29%), febrile neutropenia (9%), fatigue (9%), neuropathy (7%), and thrombosis (6%) on the ixabepilone + EMP arm. Post-treatment declines in prostate-specific antigen of ≥ 50% were achieved in 21 of 44 patients (48%; 95% CI, 33% to 64%) on the ixabepilone arm, and 31 of 45 patients (69%; 95% CI, 55% to 82%) on the ixabepilone + EMP arm. In patients with measurable disease, partial responses were observed in eight of 25 patients (32%; 95% CI, 14% to 50%) on the ixabepilone arm, and 11 of 23 (48%; 95% CI, 27% to 68%) on the ixabepilone + EMP arm. Time to prostate-specific antigen progression was 4.4 months (95% CI, 3.1 to 6.9 months) on the ixabepilone-alone arm and 5.2 months (95% CI, 4.5 to 6.8 months) on the combination arm.

Conclusion

Ixabepilone, with or without estramustine phosphate, is well tolerated and has antitumor activity in patients with castrate metastatic prostate cancer.
A histochemical study of the hamster ovary
Authors: Guraya Sardul S. , Greenwald Gilbert S.
Published: February 2005

The hamster ovary has been studied histochemically for various lipids. The granulosa cells of normal follicles contain lipid bodies of various sizes composed mainly of phospholipids. Some lipid bodies also contain triglycerides, cholesterol and its esters. The theca cells contain lipid granules consisting of phospholipids. At the onset of atresia, the granulosa stores lipids abundantly which consist of triglycerides, cholesterol and its esters and a slight amount of phospholipids. The theca of atretic follicles, also stores lipids consisting of phospholipids first, and then in sequence phospholipids and triglycerides and finally phospholipids, triglycerides, cholesterol and its esters. The theca hypertrophies and persists to form the interstitial gland whereas the granulosa cells, with their lipid droplets, regress and disappear. The interstitial gland in the hamster ovary occurs as patches of various sizes and these are derived from the theca of atretic preantral and antral follicles. Most of the lipid droplets of the interstitial gland, are mobilized within the preovulatory ovary. The replenishment of lipid droplets begins on day 1 of the cycle (metestrus). On day 2, the interstitial gland is again filled with lipid droplets which are rich in cholesterol and its esters, triglycerides and phospholipids.

In ovaries treated with pregnant mare's serum (PMS) on each of the days of the estrous cycle, numerous large preantral follicles having 4–7 layered granulosa, are stimulated to ovulate. Normally such follicles become atretic, indicating that a lack of sufficient endogenous pituitary gonadotrophins prevents these follicles from maturing. Neutral lipids, especially cholesterol and its esters, could not be demonstrated in the normal granulosa in the PMS‐treated ovaries. The follicles, which were atretic at the time of injections, were not affected by exogenous hormones. Human chorionic gonadotrophin (HCG) did not conspicuously affect the growth of follicles. Both PMS and HCG caused mobilization of lipid droplets from the interstitial gland.
The lymphatic system of Didelphys azarae and Didelphys marsupialis
Authors: Azzali Giacomo , Didio Liberato J. A.
Published: February 2005

The lymphatic system of 45 Didelphys azarae and 15 Didelphys marsupialis, both species found in Brazil, were studied after injection of Prussian blue suspension and neoprene latex (the latter followed by partial corrosion). The data concern the lymph nodes, the lymphatic networks, vessels and principal trunks. The lymph nodal system in Didelphys is less developed (several nodes are missing) than that of the rodents of the same size. In Didelphys, the posterior cranial mediastinal lymph nodes are well developed: the right node receives the lymph from the stomach and diaphragm through vessels draining the para‐esophageal, anterior mediastinal and caudal bronchial nodes, a fact not yet observed in other mammals. Each organ or area has its own lymph nodal station. The posterior para‐aortic lymph nodes are almost always absent in the males, while in females only the right one is found. The common iliac lymph nodes are missing and it seems that they are replaced by lymphatic dilatations. Only one lymph node is found for the small intestine and two for the large intestine. The lymphatic networks are simple — 4–5 patches are found in the small intestine and one is constant in the terminal ileum. Other features are the separate drainage of each vaginal cornu and the partial duplication of the thoracic duct.
An electron microscope study of the development of the somatic muscle of the chick embryo
Authors: Dessouky D. A. , Hibbs Richard G.
Published: February 2005

Somites 16 through 18 were obtained from chick embryos from 36 hours to 15 days incubation, and prepared for both light and electron microscopy. It was found that the myoblasts in the early stages increase in size and become elongated. Myofilaments of two types are first discernible in the peripheral cytoplasm in the 32 somite stage. Those of one type are about 100 Å in diameter and are probably myosin, while the others are approximately 70 Å and are believed to be actin. These filaments are organized into bundles (myofibrils) which are from the first striated. Throughout later development recognizable myofibrils are present; alongside are found numerous myofilament bundles in all stages of development indicating continuous myofibril formation. Smooth‐surfaced vesicles and tubules become the main constituent of the sarcoplasmic reticulum. Free ribosomes numerous at first, take up positions around the developing filament bundles and decrease in number as the myofilaments are formed. At the time of appearance of the first myofilaments, glycogen granules become visible in the sarcoplasm and increase rapidly in number. The mitochondria become arranged between the developing myofibrils.
The fine structure of bat spermatozoa
Authors: Fawcett Don W. , Ito Susumu
Published: February 2005

The fine structure of epididymal spermatozoa of Myotis lucifugus and Eptesicus fuscus is described. Caudal to the acrosomal cap in both species, a thin intermediate layer is described as uniting the plasmalemma to the outer leaf of the nuclear envelope. Although this layer does not form a separate cap‐like structure, it evidently corresponds to the “post nuclear cap” of light microscopists. A redundant portion of the nuclear envelope turns away from the condensed chromatin and continues caudad into the neck region where it forms a pair of concentric membrane systems on either side of the connecting piece. Two flattened mitochondria are closely applied to the dorsal and ventral aspects of the connecting piece.

The sperm tails in the two species are generally similar except for the shape and distribution of mitochondria in the middle‐piece and the thickness of the fibrous sheath of the principal piece. A unique arrangement of the mitochondria in Myotis makes it possible to determine the orientation of the plane of the central pair of flagellar fibrils in relation to the transverse axis of the flattened head and hence to deduce the probable plane of bending movments of the tail. Cortical and medullary zones are distinguished in the outer dense fibers of the flagellum and fibers 9, 1, 5, and 6 are consistently larger than the others. A set of slender satellite fibers are closely related to the inner aspect of the nine large outer fibers. Additional structural details of the axial filament complex are described, especially the cross‐sectional configuration of the subfibrils in the doublets and their mode of termination in the end‐piece. No “secondary fibers” or “mid fiber” were found.

Since the axial filament complex of mammalian sperm tails is not continuous with a basal body, as in other flagella, it is suggested that the connecting piece is a centriolar derivative and may be the functional equivalent of a basal body for both the axial complex and the outer dense fibers.

Comparisons are made of bat sperm tails and those of other mammalian species and the ultrastructure and arrangements of tail components are discussed in relation to the current concepts of sperm locomotion.
A study of salivary glands of rats injected with actinomycin D
Authors: Jhee Heun T. , Han Seong S. , Avery James K.
Published: February 2005

A study has been made of the salivary glands of the rat following an injection of a sublethal dose of actinomycin D. Body weights and weights of the parotid and submandibular glands showed significant decreases during the first 7 to 14 days. The loss in weight was the greatest in the parotid gland.

Histological and cytological observations indicated that the changes in secretory cells occurred in the following order: (1) beginning of nuclear pyknosis with a rapid decrease in number and size of nuclei by 24 hours after the injection; (2) advanced stages of nuclear pyknosis with concomitant decrease in cytoplasmic basophilia and granules by day 3; (3) apparent vacuolization and rarification of cytoplasm by day 7; (4) beginning of nucleolar and nuclear recovery by day 10; and (5) complete cytoplasmic recovery by the end of experiment as evidenced by the return of basophilia and disappearance of vacuoles.

Paralleling the weight changes, cytological damages were greater in the parotid than in the submandibular acini. This was thought to be related to differences in nature of secretory products by the two organs. A decrease in number and pronounced irregularity in size of the granules in salivary ducts of the submandibular gland were observed but at a later time than the above mentioned changes in the acini. The significance of these changes has been discussed in light of the recently gained knowledge on the biosynthesis of nucleic acids and proteins as related to the chemical mechanism of actinomycin D in the inhibition of m‐RNA synthesis.
Secretory epithelium of the large axillary sweat glands. A cytochemical and electron microscopic study
Authors: Biempica Luis , Montes Leopoldo F.
Published: February 2005

The secretory cells of large axillary sweat glands from 12 normal adults were studied at the light and electron microscope levels, using techniques for localization of enzyme reaction product. The morphological and cytochemical characteristics of the plasma membrane and cell organelles (Golgi apparatus, lysosomes, mitochondria, endoplasmic reticulum, secretory granules) were observed. An interpretation of the secretory process was attempted. Most of the evidence spoke against the existence of an apocrine mechanism. Possibly some of the methods employed also could be used for the demonstration of hormone action on the LASG.
Connective tissue responses to altered collagen and bone implants
Authors: Irving J. T. , Migliore S. A.
Published: February 2005

The ϵ‐amino groups of reconstituted collagen were treated in a variety of ways and the collagen implanted subcutaneously in rats. After two weeks the implants were removed and examined histologically. A giant cell response was seen around the collagens treated with 1‐fluoro‐2,4‐dinitrobenzene, p‐nitrobenzoylchloride or carbobenzoxychloride, but not with the other reagents. Parallel experiments with autogenous bone, treated with the same methods, were carried out. A mild giant cell response was found in the untreated bone, but was enchanced only in bone treated with the same three reagents. It would appear that the giant cell response was greatly increased when the attached benzene ring had nitro groups in the para position, and also when there was an ester linkage in the attached radicle. It is unlikely that this reaction was immunological in character. The giant cells have many of the properties of osteoclasts. It is suggested that it is the nature of the organic matrix of bone that determines if osteoclasis shall occur.
A comparison of the incisor teeth of intact, hypophysectomized and thyropara‐thyroidectomized rats
Authors: Gavin J. B.
Published: February 2005

Three types of macroscopic incisor abnormality were observed in Wistar rats examined post mortem. Most common was an altered relationship of the incisors to one another due to either fracture, elongation, rotation, malposition, or a combination of these factors affecting one or more incisors. Enamel hypoplasia was evident as opaque whitish blotches, bands or fine transverse striations. Other incisors showed an overall uniform pallor of the enamel. These abnormalities frequently affected the same animal or the same incisor. The associations between them were significant (P< 0.01). All the incisors of the intact group were normal and the incidence of abnormalities in hypophysectomized rats was not significantly higher (P > 0.05). However, of the thyroparathyroidectomized animals 56.8% had an abnormal incisor relationship, 28.4% showed discrete enamel defects and 23% showed enamel pallor. The incidence of all types of abnormality was higher in surgically thyroparathyroidectomized rats (P< 0.05) than in other groups. No significant differences were found between completely and incompletely thyroidectomized rats or between subgroups which received different drug treatments. These findings are discussed in relation to similar reports and hypotheses are advanced to explain the abnormalities. Parathyroid deficiency rather than thyroid deficiency appears the most important etiological factor.
The fine structure of the aglomerular nephron of the toadfish, Opsanus tau
Authors: Bulger Ruth Ellen
Published: February 2005

Kidney cell fine structure in the aglomerular fish, Opsanus tau, varies profoundly with different fixation procedures. An extensive system of cisternae, tubules and irregular‐shaped elements of smooth‐surfaced membranes are seen in the basal cytoplasm after fixation with 2% OsO4 buffered with s‐collidine. Permanganate fixation demonstrates these membranes as extensions of the basal plasmalemma. Mitochondria and homogeneous bodies surrounded by a single dense membrane lie in close association with the basal membranes. The apical cytoplasm contains an abundance of smooth‐surfaced elements whose morphology varies with the fixation procedure used. The fine structure of these cells is discussed with respect to that of other ion transporting tissues and with respect to the concept that basal infoldings are related to “water reabsorption”.
Electron microscopic observations of neurosecretory granules, nerve and glial fibers, and blood vessels in the median eminence of the rabbit
Authors: Duffy P. E. , Menefee M.
Published: February 2005

The median eminence of the rabbit has been studied electron microscopically and the neurosecretory granules in the nerve terminals of the external layer were shown to be smaller and have a denser central core than the granules composing Herring bodies which are generally larger and have a paler core which is finely granular or vesicular. It was proposed that the small dense granules, which may represent neurosecretory substances destined to reach the pars distalis via portal veins, reach the nerve terminals in the external layer via certain dilated fibers described in this paper which contain identical granules. Some may also arise from the small dense granules occasionally seen in Herring bodies.

The demonstration of neurotubules within Herring bodies and the continuity of nerve fibers into Herring bodies, as well as the demonstration of myelin around some aggregates of large pale granules such as those seen in Herring bodies are further evidence that Herring bodies are dilated axons. Wide perivascular connective tissue spaces and interfibrillary spaces were generally seen in the external but not the internal layers. The absence of neurosecretory granules from the perivascular connective tissue spaces suggests that neurosecretory granules go into solution before entering the connective tissue space. Some fibers containing neurosecretory granules, however, penetrated through the basement membrane into the perivascular spaces and certain unidentified electron dense granules were seen beneath the basement membrane of blood vessels.
Antigen (ferritin) and antibody distribution in the rat lymph node after primary and secondary responses and after prolonged stimulation
Authors: Buyukozer Ilhan , Mutlu Kamile Sevki , Pepe Frank A.
Published: February 2005

With electron microscopy it was observed that ferritin antigen was taken up in pinocytotic vesicles by the reticular cells. No antigen was observed in lymphocytes, in immature or mature plasma cells after primary and secondary stimulation, or after hyperstimulation. In hyperstimulated tissue a larger number of more complex vesicles containing ferritin were visible, more ferritin was found free in the cytoplasm and a larger number of multiple‐membraned figures were present.

Hyperstimulation led to the appearance of activated fixed reticular cells which were characterized by cytoplasm containing a rich endoplasmic reticulum with dilated cisternae and ferritin both free and in vesicles. The activated fixed reticular cells therefore contain antigenic ferritin and have the characteristics of cells engaged in protein synthesis.

Using fluorescent antibody staining no antigenic material was detectable in the antibody producing plasma cell; therefore if antigen fragments not identifiable in electron microscopy are present they are in a form not available for antibody staining. Gamma‐globulin was not detectable in the activated reticular cell. It may be necessary for the intact antigen to be completely modified and for the cell to lose its fixed position before γ‐globulin synthesis can begin.
On spirality in the intestinal wall
Authors: Elsen John , Arey Leslie B.
Published: February 2005

Methods of stripping did not demonstrate a significant spiral course of fibers within longitudinal muscle coats of the jejuno‐ileum of the dog, cat, hog or man.

Similar lack of spirality also characterized the large intestine of the dog. The presence of taeniae in the hog and man, and the extremely thin layer of muscle between them, permitted only the demonstration of directly longitudinal muscle in taeniae.

Bands of muscle stripped from circular coats of the small intestine of the dog and hog came off overwhelmingly in complete rings. Stripping of the human intestine did not yield complete rings; breakage at anastomoses with the adjoining muscle sheet may indicate oblique bands that link up a fiber system, essentially circular, into a functionally spiral system.

Bands stripped from circular coats of the large intestine of the dog came off overwhelmingly as circles. The taeniae of the hog and man prevent obtaining complete strips.

Stripping of the submucosal stratum of the small intestine of the dog and man, and of the large intestine of the dog, revealed a latticed tube. Its fibers intersect in double spirals, coursing at angles of approximately 45° to the longitudinal axis of the intestine.
Reproduction in the ferret (Mustela furo) I. Uterine histology and histochemistry during pregnancy and pseudopregnancy
Authors: Buchanan G. Dale
Published: February 2005

Similar histological and histochemical changes occur in the uteri of pregnant and pseudopregnant ferrets. The pre‐implantation period is characterized by general growth of the tissue and moderate secretory activity. At the time of implantation, the luminal epithelium undergoes hypertrophy and hyperplasia and shows much secretory activity. This area of altered activity sweeps progressively toward the gland fundi and the epithelium behind it becomes greatly enlarged and forms symplasmic masses. Symplasma formation occurs in all regions of the uterus, in contrast to other carnivores where it occurs only next to trophoblast and in response to uterine trauma.

The principal uterine secretions are mucoproteins and glycoproteins. There is some evidence that pseudopregnant uteri, but not pregnant uteri, secrete acid mucopolysaccharides. Glycogen is present in moderate amounts at estrus, declines during the pre‐implantation period, and is absent during gestation. A light to moderate diffuse sudanophilia is seen during pregnancy and pseudopregnancy, becoming more pronounced toward the end of the gestation period. Occasional cholesterol crystals are seen in macrophages in the stroma of pregnant, but not pseudopregnant, uteri. Macrophages containing hemosiderin were seen in all uteri examined, being most abundant in estrous and early pre‐implantation uteri. Uterine mast cells were abundant at estrus, declined during the pre‐implantation period and decreased markedly at the time of implantation. The results are compared with data from other carnivore species.
Histochemical studies on the Pacinian corpuscle
Authors: Shanthaveerappa T. R. , Bourne G. H.
Published: February 2005

Detailed studies on the localization of various oxidative and hydrolytic enzymes were made of the Pacinian corpuscle nerve fiber, inner core and lamellae. The nerve fiber of the corpuscle was found to be rich in specific and nonspecific cholinesterases, simple esterase, lactic dehydrogenase, succinic dehydrogenase, cytochrome oxidase, alkaline phosphatase, adenosine triphosphatase, thiamine pyrophosphatase, and 5‐nucleotidase enzymes. It showed moderately positive activity for acid phosphatase, and negligible activity for monoamine oxidase. The lamellar cells and the inner core cells showed mild to moderate positive activity for all these enzymes excepting monoamine oxidase, specific and nonspecific cholinesterases, for which they were negative. The relationship between these cells and the perineural epithelium of peripheral nerves and the pia‐arachnoid mater of the central nervous system was discussed.
Oocytogenesis in rabbits. The role of neogenesis in the formation of the definitive ova and the stability of oocyte DNA measured with tritiated thymidine
Authors: Kennelly J. J. , Foote R. H.
Published: February 2005

A series of six thymidine‐methyl‐H3 (thy‐H3) injections, one every 12 hours, was administered to 35 Dutch‐belted female rabbits (does) commencing on the day of their birth. Seventeen of the does were unilaterally ovariectomized as follows: five does at 4 and 12 weeks of age, five does at 4 and 20 weeks of age, five does at 12 and 20 weeks of age and two does at 4 and 40 weeks of age. Autoradiographs of ovarian tissue were prepared, up to 600 oocytes per ovary were randomly chosen and the silver grains associated with the oocyte nuclei recorded. The mean grain counts decreased significantly (P < 0.05) from 4 to 12 weeks, 13.5 vs. 10.1, and from 4 to 20 weeks, 14.7 vs. 11.4. However, the mean grain counts did not differ significantly (P > 0.1) between 12 and 20 weeks of age, 10.5 vs. 9.6. Although the mean grain count decreased between 4 to 40 weeks of age 21.5 vs. 14.6, the number of replications was too few to detect significant differences (P > 0.1). At 40 weeks of age 91% of the oocytes were still labeled. The reduction in grain counts from 4 to 12 weeks of age was attributed to the non‐random degeneration of the older, more highly labeled oocytes located deep in the cortical zone. The lack of significant differences between grain counts at 12 and 20 weeks of age suggests that (1) during this interval the desoxyribonucleic acid (DNA) is metabolically stable and (2) significant de novo oocyte formation did not occur. Nine rabbits were superovulated at 20 weeks of age and of the 217 ova recovered 82.5% were radioactive. This was similar to the 89.8% radioactive oocytes observed in the ovaries of the same animals.

Artificial insemination of the remaining nine does at 35 and 60 weeks of age resulted in normal litters and superovulation and artificial insemination of this group at 52 weeks of age produced 73.8% radioactive ova.

Five Dutch‐belted does injected at four weeks of age with thy‐H3 at the same rate and interval as the day‐old rabbits showed a slight incorporation of the isotope into both oocyte nuclei and cytoplasm suggesting that most of the incorporation was not related to any synthesis of new chromosomal DNA. A single thy‐H3 injection into three 20‐week‐old does did not result in appreciable uptake of the isotope by oocyte nuclei, although many nuclei of parenchymal cells in the ovary were highly labeled.

The results conclusively support the view that most, if not all definitive ova are formed at birth and de novo oocytogenesis does not occur in the post‐pubertal rabbit.
An electron microscopic investigation of osteogenesis in the embryonic chick
Authors: Decker Jay Donovan
Published: February 2005

Cell‐matrix and bone‐matrix relationships have been studied by electron microscopy in the diaphysis of chick embryo tibio‐tarsus. Osteoblasts within the periosteum possess cytoplasmic machinery characteristic of cells involved in protein synthesis. They contain abundant ergastoplasm, and an extensive Golgi apparatus. Small vesicles are associated with the juxtanuclear Golgi apparatus as well as with the extensive ergastoplasm. This suggests that the mechanism of protein synthesis and its transfer to the external milieu may be similar to that of other protein secreting cells, the fibroblast, the odontoblast and the chondroblast.

A rather wide variation in collagen fibril diameter is seen in those fibrils located between the osteoblasts and the initial ossification area. The first nucleation of apatite crystals is seen as random aggregations distinct and separate from the collagen fibrils. This appearance is independent of section orientation since there appeared to be no difference between sections oriented at right angles to or parallel with the diaphysis' long axis.

The observations of this study are consistent with proposed mechanisms for the nucleation phenomenon involving the ground substance and collagen fibrils. In addition, the observations suggest a concept of cellular control over the extracellular environment effecting the initial crystal nucleation. The morphologic evidence indicates that the molecular arrangement of collagen as fibrils probably does not provide the mechanism for apatite crystal nucleation.
Differentiation of adrenal cortex‐like tissue at the hilum of the gonads in response to adrenalectomy
Authors: Seliger William G. , James Blair A. , Mossman H. W.
Published: February 2005

Following bilateral adrenalectomy, the adrenal cortex‐like cells which appear in the ovaries of the 13‐lined ground squirrel are in close relationship to the epithelial remnants of the rete ovarii and the medullary cords. Identical cells form in the bilaterally adrenalectomized male around the efferent ductules of the testes.

Histochemical tests on these periductular cells gave positive results with polarized light, Sudan Black stain, ultraviolet light, and the Schultz test — all comparable to normal adrenal cortex cells.

Electron microscopic studies of the periductular cells showed them to have ultrastructural characteristics of a steroid secreting cell.

Male and female animals adrenalectomized a year before and maintained on tap water died within four days when the gonads and adnexa were removed. Male animals adrenalectomized a year before and maintained on tap water survived actively for two weeks when the testicles were removed, provided that the efferent ductules and surrounding adrenal cortex‐like cells were left in place. These animals died within four days after the adnexa were removed.

The periductular cells were incubated with radioactively tagged progesterone which showed that these cells secrete corticosterone, the normal primary corticosteroid of this animal, and desoxycorticosterone which functions as a combination glucocorticoid and mineralocorticoid.
The changing pattern of basophilia in the mouse uterus from mating through implantation
Authors: Smith Lois Jean
Published: February 2005

Changes in RNA localization and concentration in mouse uteri taken from one‐half to seven and one‐quarter days after mating were visualized as changes in basophilia following staining by a histochemical method specific for RNA. The basophilia of the luminal epithelium falls abruptly between one‐half and two days and is still lower at two and three‐quarter days. By 2 and three‐quarter days, however, that of the stroma and especially that of the subepithelial endothelial cells is increasing. A further slight increase is found at three and three‐quarter days and by four days, a band of subepithelial stromal cells, wider in the antimesometrial than in the mesometrial portion of the uterus, is highly basophilic. At four and one‐quarter days, when a distinct decidual reaction is evident, cells in the primary decidual zone are less basophilic than at four days. During the remaining period of observation, cells in different regions of the uterus show increased and often, later, decreased basophilia. It was concluded that these results are in complete accord with those from a recent biochemical study of changes in RNA in the intact rat uterus during the interval from induction of pseudopregnancy through deciduoma formation if the difference in timing in the two species is taken into account.
Constant cell populations in normal, testosterone‐deprived and testosterone‐stimulated levator ani muscles
Authors: Venable John H.
Published: February 2005

Castration of adult male mice produces a true atrophy of their levator ani muscles until the muscle reaches a stable weight within 45 days. Subsequent treatment with testosterone produces a true hypertrophy from the stable neutered state. The weight changes in the muscle are accounted for solely by changes in the size of the muscle fibers. No mitotic activity accompainies atrophy or hypertrophy. The number of cell nuclei and the amount of DNA in the muscle is unaltered.
Correlation of types of cortical grain structure with architectural features of the human skull
Authors: Dempster Wilfrid T.
Published: February 2005

Seven grain‐form relationships, as indicated by the split‐line patterns, are recognized in the cortical bone of the adult human skull: (1) random pattern of braincase, (2) planes and (3) ridges with elongated grain, (4) troughs with transverse grain, (5) concavities with circular grain, (6) edges, and (7) spines. Concavities may show superimposed trough or ridge structure, and troughs may be marked by localized ridges and planes. That is, trough patterns are dominant over concavity patterns, and ridge patterns are dominant over both trough and concavity patterns. Finally, there are a few small cranial areas that are random distributions in some skulls and planes in others; the skull vault proper, however, except for the forehead region and internal sagittal markings, has a random pattern throughout.

The mechanical significance of the various patterns and the areas on which they are found are discussed and explained on the basis of principles of mechanics and architecture. The form‐texture relationships are discussed as architectural features of the skull, and their adequacy and limitations are analyzed in terms of their reaction to force systems and their proneness to fracture.
A study of mineral density surrounding resorption sites in teeth
Authors: Avery J. K. , Meyers R. A. , Hale L. E.
Published: February 2005

An investigation of mineral density surrounding lacunar resorption sites in cases of both internal and external root resorption, was carried out on 37 human primary and permanent teeth. In addition, equivalent areas of the roots of 14 normal appearing teeth were studied for comparison. Thirty‐two of the teeth were analyzed using microradiographic and microhardness techniques and the remainder were studied microscopically after histologic preparation. The teeth used for microradiographic analysis were embedded in plastic, bisected and half of each tooth was sectioned at 70–100 μ. Microadiographs were taken at 9.5 kv and exposed to 30 milliamperes for 25 to 40 minutes. The other halves of the teeth were used for microhardness tests using a Tukon Microhardness Tester. One series of microhardness measurements was made 10 to 40 μ from sites of active resorption in root dentin and a second series was made 250 to 500 μ from these sites. The hardness measurements of the first series were found to be significantly lower than those of the second in cases of both external and internal resorption. Hardness values of the surface of normal appearing roots were also less than areas 250 to 500 μ deeper in the dentin. Microradiographs did not reveal any definite zone of subsurface demineralization although some resorption sites were bordered by irregular areas of decreased radiodensity which may be due to superimposition of several resorption sites within the thickness of the tooth section. Histologic observations did not reveal a definite subsurface demineralization gradient. The lacunar resorption front was found to be a multilocular and completely interconnected system.
Light and electron microscopic observations on the inner plexiform layer of the rabbit retina
Authors: Raviola Giuseppina , Raviola Elio
Published: February 2005

By comparison of electron micrographs with light microscopical specimens impregnated with the Golgi technique, the large endings of the rod bipolar cells have been identified in the innermost region of the inner plexiform layer of the rabbit retina.

The rod bipolar endings contain ribbons and synaptic vesicles, do not synapse with the perikaryon of the ganglion cells, are presynaptic to ganglion cell dendrites and to nerve processes which contain synaptic vesicles but lack ribbons. In these synaptic contacts a ribbon is closely associated with the presynaptic membrane and a dense web of fuzzy material is adherent to the cytoplasmic aspect of the postsynaptic membrane. Commonly, one of these synaptic contacts involves a rod bipolar ending and two postsynaptic processes. The postsynaptic process which is provided with synaptic vesicles is often, in turn, presynaptic to the same rod bipolar ending. This synaptic contact is characterized by the presence of a cluster of vesicles closely related to the presynaptic membrane, whereas the postsynaptic membrane lacks a definite subsynaptic web.

In the intermediate and scleral regions of the inner plexiform layer endings containing ribbons and synaptic vesicles show with neighboring nerve processes a synaptic pattern similar to the rod bipolar endings. Nerve processes containing synaptic vesicles but lacking ribbons are presynaptic to the perikaryon and dendrites of the ganglion cells; the synaptic contact shows a cluster of vesicles adherent to the presynaptic membrane. Bipolar cells are proposed as the source of the ribbon containing processes while amacrine cells are proposed as the source of the processes devoid of ribbons and presynaptic to both bipolar endings and ganglion cell dendrites and perikarya.
A light and electron microscopical study of neurofibrils and neurofilaments at neuro‐neuronal junctions in the dorsal lateral geniculate nucleus of the cat
Authors: Guillery R. W.
Published: February 2005

Neurofibrillar rings and spheres one‐half to 2 μ in diameter occur throughout the dorsal lateral geniculate nucleus of the cat. Counts confirm that they occur predominantly in laminae A and A1, and only rarely in lamina B and the central interlaminar nucleus. The rings lie in zones of lightly argyrophilic tissue between perikarya and rarely contact cell bodies. The argyrophilic zones are 5–20 μ wide, forming a continuous reticulum throughout laminae A and A1.

Electron micrographs show rings and nests of neurofilaments that match the neurofibrillar structures in size and distribution. These filaments are not found in axons, but occur in spheroid dendritic appendages, which have previously been described on Golgi preparations. The appendages lie in synaptic zones which are 5–20 μ wide and encapsulated by glial lamellae. Within the zones two major types of specialized contact are recognizable. “Regular” contacts (axo‐dendritic and axo‐axonal) resemble synaptic contacts in other parts of the CNS. “Filamentous” contacts (axo‐dendritic and dendro‐dendritic) show neurofilaments in the dendritic cytoplasm and show no concentration of vesicles on the axonal side. Within the appendages filaments from adjacent filamentous contacts join to form a nest around a group of mitochondria.

Comparison with previous studies suggests that these dendritic appendages, which receive regular and filamentous contacts, form a major receptive site for the retinal afferents.
Fine structural differences in “fast” and “slow” muscle fibers of the crab
Authors: Cohen Melvin J. , Hess Arthur
Published: February 2005

The muscle fibers in the accessory flexor muscle of the crab were examined with the electron microscope. The limiting membrane of the muscle fiber invaginates at many points to form an internal extrafibrillar membranous system between the muscle fibrils. Two types of muscle fiber were found. In one, the fibrils are well separated from each other by an extensive membranous system, the sarcomere lengths are short, and the filaments in the A band are thick. This muscle fiber is the same as the fast fiber previously found physiologically. The other type of muscle fiber has large fibrils poorly separated by a relatively scant system of internal membranes. It has relatively long sarcomeres and comparatively thin filaments in the A band. This type of fiber is the same as the slow fibers described physiologically. Fibers intermediate in type are also found. Nerve terminals with typical synaptic vesicles occur and appear similar on both types of muscle fiber under the electron microscope. Membrane thickenings of nerve ending and muscle fiber also occur at the terminals on both types of muscle fiber. The nerve terminals on the fast fiber are much more easily found and hence more numerous than on the slow fiber. A comparison is made between the invertebrate and vertebrate fast and slow fibers, and some physiological implications of these findings are discussed.
Cell number as a measure of distribution and renewal of epithelial cells in the small intestine of growing and adult rats
Authors: Altmann G. G. , Enesco M.
Published: February 2005

By the use of DNA determinations and cell counts with and without previous colchicine treatment, the absolute numbers of villus epithelial cells, and of dividing and nondividing crypt epithelial cells were determined in ten successive segments of the small intestine of 17‐day (weanling), 37‐day (young) and 87‐day old (adult) male rats.

In adults, the number of villus epithelial cells per segment decreased gradually in the duodenoileal direction, while the number of dividing and nondividing crypt epithelial cells remained fairly constant. It was deduced that the turnover time of the villus epithelium gradually decreases, but that of the crypt epithelium remains constant along the small intestine.

When the entire small intestine was considered, from weanling to adult age, the relative and absolute numbers of dividing and nondividing crypt epithelial cells increased; the calculated number of epithelial cells produced daily rose from 112 million to 1796 million. Meanwhile, the rate of growth of the intestinal epithelium diminished allowing more and more of the produced cells to participate in renewal: about 25, 885 and 1796 million cells daily in weanling, young and adult rats, respectively. The mean turnover time of the intestinal epithelium decreased from about 22 days in weanling rats to about 2.1 days in adult rats, indicating a tenfold increase in renewal rate.
Observations on the fine structure of spermatozoa of the bush baby (Galago senegalensis), the African green monkey (Cercopithecus aethiops) and man
Authors: Bedford J. M.
Published: February 2005

A description is given of some fine structural features of mature spermatozoa from the bush baby (Galago senegalensis), the African green monkey (Cercopithecus aethiops) and man, with additional comments on sperm from the slow loris (Nycticebus coucang) and the crab‐eating macaque (Macaca irus). The arrangement of the sperm organelles in these primates is similar to that demonstrated in the sperm of other mammals, but notable species differences do occur. The bush baby spermatozoon, for instance, displays a complex system of membranes which envelop the neck and anterior midpiece. The human spermatozoon, unlike that of many other mammals, has no subacrosomal space or “perforatorium.” This structure is quite prominent, however, in lorisoid and macaque spermatozoa, and it is shown in the bush baby that its electron‐dense material extends posteriorly from the apex of the head in the space between the inner acrosome and nuclear membranes. In electron microscope preparations of anthropoid spermatozoa, the cell membrane which overlies the acrosome cap only occasionally displays the swollen distorted form seen commonly here in the spermatozoa of prosimiae, and previously in various other mammals.

In contrast to the uniform spermatozoa obtained from the lorisoid and macaque monkeys, a significant proportion of spermatozoa in the human samples examined showed many abnormal features including misshapen sperm nuclei, cystic formations in the rostral region of the acrosome cap, and irregular alignment of mitochondria in the neck and midpiece.
Ultrastructural and histochemical analysis of cytoplasmic laminar bodies in lateral geniculate neurons of adult cat
Authors: Doolin Paul F. , Barron Kevin D. , Kwak Sharon
Published: February 2005

The structure of highly organized, cytoplasmic laminar bodies (CLB) of cat lateral geniculate body neurons is described. CLB are derived from endoplasmic reticulum (ER). The occurrence of other cytoplasmic bodies also derived from ER and mesh‐like in composition is noted. Stacks of dense membranous elements, restricted to one pole of each type of cytoplasmic body, were encountered. Mention is made of the relative persistence of CLB in atrophic neurons that show marked changes including loss of cytoplasmic granular ER.

The tubules of CLB are normally coextensive with the granular ER. The topographic relationships of CLB with other cellular organelles such as mitochondria, Golgi complex and the nucleus are discussed.

Routine staining techniques clearly demonstrate the CLB in 2 μ paraffin sections of tissue fixed by perfusion with buffered formalin. Histochemical tests show that CLB are chemically complex structures containing protein, lipid and polysaccharide components.
A histochemical study of epithelial mucin in the chick chorioallantois
Authors: Conklin James L.
Published: February 2005

Histochemical methods demonstrate the accumulation of two types of mucous inclusion in the allantoic epithelial cells of the chick embryo.

One type of inclusion contains a sialomucin that is PAS‐reactive, unstained by Alcian blue and other anionophilic dyes and is susceptible to digestion by Vibrio cholerae neuraminidase.

The second inclusion contains an apparent sulfomucin which is Alcianophilic at pH 1.0, unstained by anionophilic dyes after a methylation‐demethylation sequence and resistant to testicular hyaluronidase. This sulfomucin exhibits PAS reactivity after desulfation procedures.

Both types of mucus occur in individual cells and are normal components of the chorioallantois. Accumulation of the inclusions is enhanced by lowering the pH of the allantoic fluid or as a result of organ transplantation.
Electron and light microscopic observations on relationships between lymphocytes and intestinal epithelium
Authors: Meader Roland D. , Landers Dennis F.
Published: February 2005

Correlated electron and light microscopic studies of the distribution, position, appearance, migration and fate of lymphocytes with relation to the intestinal epithelium of the young adult rat, mouse, hamster and man have been made. Under the conditions of this investigation, the lymphocytes which are normally present in the intestinal epithelium are intercellular in position, irrespective of their level within the epithelium. The great majority of these cells are located in the basal region of the epithelium, below the level of the epithelial cell nuclei. There was no evidence of lymphocytic degeneration. Lymphocytes migrated from the lamina propria into the epithelium and back again into the lamina propria, with no evidence of movement toward the free surface of the intestinal epithelium and extrusion into the lumen.
The ultrastructure of the enamel organ related to enamel formation
Authors: Elwood William K. , Bernstein Maurice H.
Published: February 2005

The ultrastructure of the cells of the enamel organ related to enamel formation was studied using the lower incisors of adult male rats. In the region of enamel deposition, stratum intermedium cells are stabilized by a system of intercellular bridges and intracellular fibrils. The mitochondria in these cells are positioned toward the extracellular channels through which any direct intercellular exchange between the capillaries and ameloblasts must occur. Tentatively, the mitochondrial arrangement is considered to be related to the movements of electrolytes and water across the capillary‐ameloblast interval.

In the region of transition, enamel deposition ceases and the ergastoplasm of the ameloblasts is removed, apparently by cytosegresomes, with an accompanying reduction in the height of the ameloblasts. Here, vesicles containing stippled material are infrequent compared to their occurrence in ameloblasts concerned with enamel deposition. Other vesicles, characteristically found in ameloblasts related to maturing enamel, first appear in the transition region and seem to originate from the cell membrane abutting on the enamel.

In the region of maturation, cytosomes are common in the Golgi region whereas vesicles and mitochondria predominate in the distal ends of the ameloblasts. The papillary cells contain an unusually large number of mitochondria, elaborate microvilli and vesicles, which suggests that these cells are extremely active, presumably in the movement of materials related to enamel maturation.

The changes in structure of the papillary cells, which occur concomitantly with those of the ameloblasts during enamel formation, are indicative of interrelated functional changes and strongly support the concept of ameloblasts and papillary cells acting together as a functional unit.
Dense‐core microtubules in neurons and gliocytes of the toad Bufo arenarum Hensel
Authors: Echandía E. L. Rodríguez , Piezzi R. S. , Rodríguez E. M.
Published: February 2005

Numerous microtubules of nerve cells and gliocytes in the toad are found, in electron micrographs, to contain a dense core. Such content is granular in nature, the granules being irregularly disposed in the lumen of the microtubules. Comparative observations on dense‐core microtubules in peripheral and central nerve cells indicate that they are consistent cell components in the entire nervous system of the toad. The functional significance of the granular content of the microtubles is discussed.