bluuebunny/crossref_metadata_2025 huggingface dataset:
Lipid‐depleted white adipose cells: An electron microscope study
Authors: Napolitano Leonard , Gagne Harriet T.
Published: February 2005

This report presents an electron microscope study of white adipose cells depleted of their lipid inclusion by prolonged low food intake. The tissue was fixed in phosphate‐buffered 1% osmium tetroxide, embedded in Vestopal W, and sections were stained with lead hydroxide. Such cells differ in shape and size from signet‐ring cells. They are ovoid, diminished in size, and the cell surface has become indented in all planes of the cell. The intercellular space is expanded with concentrations of collagen fibers in close association with the cell surface. These changes are presumed to be mechanical events associated with loss of lipid from the cell. Subcellular changes include the appearance of an extremely large number of pinocytotic vesicles and cytoplasmic vesicles similar in appearance, membrane‐bound dense bodies, five‐layered membranous structures, vesiculated bodies, and areas of flocculent material. Mitochondria and nuclei appear to be similar to their counterparts in signet‐ring cells. Observations are discussed with relation to ultrastructural changes reported in other studies in which adipose cells were depleted of fat by acute starvation or experimental deprivation of insulin. It is suggested that intracellular structural changes are probably associated with adaptive alterations in the metabolism of the cell.
Intraneuronal capillary
Authors: Cammermeyer Jan
Published: February 2005

Male rabbits, subjected to transection of the facial nerve, were narcotized and fixed by a two‐step perfusion procedure with a modified Heidenhain's Susa solution. The autopsy was delayed four hours or more. Serial sections of the rhombencephalon were stained with periodic acid‐Schiff and gallocyanin.

The course of a capillary through the perikaryon of three facial motor neurons is established beyond doubt by the study of companion sections with series of photomicrographs. The capillary is only partly in contact with the cytoplasmic membrane in its passage through the neuron.

This form for neuronal blood supply must be regarded as extremely rare. Previously, it has been unequivocally depicted in a single large pyramidal neuron of the human cerebral cortex.
Localization of thalamic projection of afferents from the tongue in the cat
Authors: Emmers Raimond
Published: February 2005

Neuroanatomical nuclear configuration corresponding to the projection regions for the chorda tympani, the IXth, and the lingual nerves was studied in the cat thalamus by a combination of electrophysiological, stereotaxic, and histological techniques. Each of the three nerves innervating the tongue was dissected for stimulation in cats deeply anesthetized with Nembutal. Maps of the extent of the thalamic projection for a particular nerve were obtained by recording evoked potentials in the thalamus during the stimulation of one of these nerves. Such maps were correlated with the anatomical structures of the cat thalamus by reconstructing the recording sites from histological sections of the cat brain. It was found that the chorda tympani and the IXth nerve projection regions correspond closely to the ventromedial nuclear complex with slight encorachment on the lingual nerve projection region in the ventrobasal complex. The most medial portions of the taste nerve projection regions do not relay any tactile afferent impulses and the most lateral portion of the lingual nerve projection is not activated by impulses in the taste nerves. Therefore, it is suggested that the thalamic relay of taste is not coextensive with other lingual modalities in the cat thalamus but it has an independent representation in the ventromedial nuclear complex.
Effect of transplacental mitotic inhibitors on the fetal hamster eye
Authors: Ferm Vergil H.
Published: February 2005

Congenital malformations of the hamster eye, consisting of microphthalmia and anophthalmia have been noted consistently in the offspring of pregnant hamsters treated with intravenous injections of colchicine, Vinacaleukoblastine (VLB) and Vincristine (VCR) on the eighth day of gestation. In an attempt to compare the mitotic‐arresting activity of these three compounds on the lens and retina of the fetal hamster eye, various concentrations of the drugs were injected into pregnant hamsters on the fourteenth day of gestation and the fetuses recovered after three hours. Mitotic counts were done on comparable sections of lens and retinas of the fetuses. Colchicine has the most marked mitosis‐inhibiting activity of these three drugs. The most effective mitosis‐inhibiting dosage of colchicine also correlates with its most effective teratogenic dose. VLB and VCR do not inhibit mitosis in the fetal hamster eye as markedly as colchicine and their most effective mitosis‐inhibiting dosages are equal to or above levels which cause a 95–100% embryonic mortality. It is possible that some common biological mechanism other than inhibition of mitosis may be responsible for the similar teratogenic activity of these compounds. The natural resistance of the golden hamster to colchicine does not appear to be manifest in the developing embryos in utero.
Studies on the perifollicular region of the rat's spleen
Authors: Snook Theodore
Published: February 2005

A marginal sinus, formed by the anastomosed terminations of white pulp capillaries, bounds the inner edge of the marginal zone. The endothelial lining on the nodular surface is complete. Pores appear along the lateral aspect thus allowing blood to pass freely into the interstices of the marginal zone. A dense aggregation of Marshall's metalophil cells occurs in the region of the marginal sinus. Such cells are lacking in the marginal zone.

Intravenous injections of particulate matter were used to determine the course of blood flow and phagocytic potential. Ten minutes after injections, particles were found to be dispersed among the cells of the marginal zone. None were found in the marginal metalophils. In four hours the particles had cleared the marginal zone and were within red pulp macrophages. In a few rats, the marginal metalophils reacted positively to tests for iron. It is concluded that marginal metalophils represent a large reserve of potential phagocytes situated at a point where blood first leaves capillaries to enter tissue interstices.
The effects of unilateral ovariectomy on follicular maturation in the guinea pig
Authors: Hermreck Arlo S. , Greenwald Gilbert S.
Published: February 2005

A control group of guinea pigs ovulated 3.43 ± 0.41 ova or 1.72 ova per ovary. Unilateral ovariectomy (semispaying) on day 1 resulted in the ovulation of 3.71 ± 0.37 ova from the remaining ovary, whereas after semispaying on days 5 and 10, 2.80 ± 0.12 eggs were ovaluated. Unilateral ovariectomy during days 12, 14 and just prior to ovulation resulted in the same number of ova being ovulated from the remaining ovary as from the initial ovary removed. Semispaying at any day during the cycle did not alter cycle length.

At day 1, all follicles from the previous cycle were atretic. At day 5 the current population of follicles were well developed with no atresia present. Ovaries removed on days 5, 10, and 12 had approximately the same distribution of large follicles with atresia appearing in all size ranges. At day 14, the number of large follicles was markedly decreased. However, after semispaying at day 5, the remaining ovary at day 14 had twice the number of Graafian follicles and twice the amount of atresia in these size ranges as the normal day 14 ovary.

It is therefore likely that the compensatory response after unilateral ovariectomy in the guinea pig is due to an increase in the rate of proliferation of smaller sized follicles into larger ones. Day 12 seems to be the critical period of the guinea pig cycle. At this time, regression of the corpora lutea occurs, and perhaps of significance, the ability of the animal to compensate for unilateral ovariectomy is also lost.
Microradiography of the pulmonary microcirculation
Authors: Quigley Mervyn B. , Leathers James E. , Reeves John T.
Published: February 2005

Conventional radiographs of lungs of calves which had been injected post mortem with barium sulphate could not be used to demonstrate vessels smaller than 50 μ in diameter. To overcome this difficulty, frozen sections 50–150 μ thick were floated on to high resolution photographic plates and contact microradiographs made using soft radiation. The resultant microradiogram was then viewed and photographed with the light microscope. It was possible to visualize the smaller arterioles and the capillary networks around the alveoli. The technique is simple and gives reproducible results.
Uptake of colloidal particles by cells of the caput epididymidis
Authors: Burgos Mario H.
Published: February 2005

Colloidal mercuric sulfide injected into the rete testis adhered to the stereocilia of the epithelial cells and subsequently moved into a highly developed canalicular system in the apical cytoplasm. The canalicular invaginations of the cell surface arising between the stereocilia lead to cytoplasmic vacuoles that concentrate the particulate matter. The limiting membrane of the stereocilia and of the canaliculi and vacuoles is covered by a layer of amorphous material. It is speculated that this may bind particles, molecules, and ions as does an ion exchange resin, and that it may, in this way, act as a carrier in the uptake and transport of substances by cells.
Mucosal enzymes in the cecum of conventional and germfree mice
Authors: Jervis Helen Roland , Biggers David C.
Published: February 2005

The morphology of the cecal mucosa and the topographic distribution of certain mucosal enzymes were compared in conventional and germfree mice to investigate the phenomenon of cecal enlargement observed in germfree animals. The cecal mucosa is predominantly non‐villous in the conventional, but has a villous structure in the germfree mice. Alkaline phosphatase, in the conventional mice, is present in the striated border of a limited number of the epithelial cells lining the cecum; in the germfree mice almost all these epithelial cells show enzymatic activity. Acid phosphatase is more abundant in the epithelial cells and macrophages of the cecal mucosa of the conventional than of the germfree animals. Both groups show similar monoamine oxidase and reduced diphosphopyridine nucleotide diaphorase activity. The reduction of the villi, and the decrease in alkaline phosphatase activity in the conventional mice point to an involution of the mucosa as an absorptive organ. Barka ('63) has suggested that acid phosphatase may have a defensive function; its increase in the conventional animal would support this interpretation. The two oxidative enzymes studied apparently are not influenced by the intestinal flora.
Changes induced by sustained pressure in the knee joint articular cartilage of adult rabbits
Authors: Crelin E. S. , Southwick W. O.
Published: February 2005

The right knees of rabbits were rigidly fixed with metal clamps midway between full flexion and full extension. After six dayas the knees of six were preserved while clamped. Twenty other rabbits were sacrificed after 16 days. Ten received colchicine on the eighth, eleventh and fifteenth day following clamp application. Their knees were preserved after clamp removal. The femoral and tibial articular cartilages subjected to pressure for six days were extremely compressed but viable. In knees clamped for 16 days the changes found were related to the amount of knee movement present at autopsy. Where it was small but easily detectable the cartilages were normal. Where there was no movement the cartilage was dead. Where it was only slight variable cartilage changes were found ranging from surface abradement, Matrix swelling, enlargement of lacunae and chondrocytes, increased number of cells per lacuna, and an occasional chondrocyte in mitosis, to an extensive matrix alteration resulting in the disappearance of lacunae, chondrocytes released from the confines of lacunae and interspersed among a meshwork of fine collagen fibers, and a few released chondrocytes in mitosis. The most extensive change was where the cartilage defect area was occupied by a mass of proliferating richly‐cellular tissue. The knee articular cartilage changes of this experiment are compared with those occurring during pregnancy in the pubic symphyseal cartilage of mice.
Experimental heart‐block in the chick embryo
Authors: Paff George H. , Boucek Robert J. , Klopfenstein Harold S.
Published: February 2005

While studying the electrocardiograms of developing hearts it was noted that an adult type ECG could not be obtained in an embryonic heart which could not be blocked with digitalis. The need to know more about heart‐block was obvious. Intact embryos of 36 to 120 hours were floated on to glass plates and treated with digoxin‐Tyrode solution. Before 36 ± hours no dissociation of beat could be produced. The heart just stopped. At 40 ± hours a conal block followed by a midventricular block appeared. At 42 ± hours conal and midventricular blocks were followed by the first appearance of AV block. It was intermittent. At 47 ± hours conal block jumped to an incisive AV block. Midventricular block was rare. At 72 hours conal and then AV block occurred. Combinations such as four atrial to two ventricular to one conal beat could be readily produced while blood circulated.

Electrocardiograms and cinephotomicrographs were taken of 72 and 96 hour hearts. Most striking was the fact that the typical Wenckebach phenomenon of adult heart‐block could be duplicated, i.e., an increase of PR interval preceding AV block followed by a shorter PR interval which again gradually increased preceding AV block. This sequence was repeated over and over. An explanation of these events is offered.
Alterations in submandibular and retrolingual glands following parasympathetic denervation in rats
Authors: Peronace Angela A. V. , Davison Tomás A. , Houssay Alberto B. , Perec Carlos J.
Published: February 2005

Alterations in size and structure of submandibular and retrolingual glands of the rat produced by unilateral sectioning of the chorda tympani, or the lingual nerve, or the glandular branch which leaves the lingual and innervates both glands, are described. The glands were studied 1, 2, 4, 8, 12 and 16 days after nerve section.

The weight of the glands increased the first day after nerve section and decreased markedly from then on, reaching 40 to 70% of the initial weight after 16 days. In the glands where the chorda tympani or the lingual nerve were sectioned the increase in weight was attributed to the accumulation of secretion in the acinous cells. After that, a progressive atrophy developed, being more severe in the acini than in the tubes. In the cases where the glandular nerve was sectioned a wide necrosis probably of vascular origin was produced, followed by parenchymatous regeneration.

In both cases 16 days after nerve section glands were small, fibrous and with little parenchyma.

The role of the parasympathetic nerves in controlling the normal structure of submandibulars and retrolinguals is discussed.
Changes in the vertical dimensions of the human male skull during the third and fourth decades of life
Authors: Thompson John L. , Kendrick George S.
Published: February 2005

A cephalometric radiographic appraisal of vertical skull growth occurring during the interim of one year was made on 71 caucasoid males at the Baylor University College of Dentistry, Dallas, Texas. The subjects were from 22 to 34 years of age. The dimensions assessed were the total skull height, the anterior cranial height, total facial height, upper facial height. and lower facial height. A significant increase was shown to occur in all the dimensions over a period of one year except in the dimension of anterior cranial height. It was concluded that skull growth does occur in male adults after the age generally accepted as that of maturity.
The extent of cardiac muscle in the great veins of the dog
Authors: Carrow Rexford , Calhoun M. Lois
Published: February 2005

The extent and arrangement of cardiac muscle in the great veins of adult dogs of both sexes was investigated. Cardiac muscle was found for varying distances in the venae cavae and pulmonary and azygos veins in all animals. The average distances which the muscle extended into these vessels in the beagles were: 1.88, 0.859, 0.525, and 0.622 cm. Similar measurements in the poodle were: 1.35, 0.705, 0.764, and 0.690 cm and in the shepherd: 3.05, 1.36, 1.22, and 0.926 cm. Both the venae cavae and pulmonary veins contained circular, spiral and longitudinal muscle bundles. The cardiac muscle was continuous from the superior venae cavae into the wall of the azygos vein and appeared to occupy the medial layer of the wall in all instances. Elastic and white fibrous connective tissue extended between the muscle bundles and appeared to invest the tapered muscle fibers in some places.
Double superior venae cavae with completely paired azygos veins
Authors: Nandy Kalidas , Blair Charles B.
Published: February 2005

A case of double superior venae cavae with bilaterally symmetrical azygos veins is recorded for a 45 year old Caucasian male cadaver with no history of cardiovascular disorder. Death was reported as resulting from carcinoma of abominal viscera with extensive metastases.

A review of the literature since 1887 indicates that this is an addition to 216 cases of double superior venae cavae and seven cases of double azygos veins previously reported in cadavers.

A typical left brachiocephalic vein was absent. The anomalous vena cava, formed by union of left internal jugular and left subclavian veins behind the sternoclavicular joint, coursed vertically through the superior mediastinum, continued through the atrioventricular sulcus and opened into the right atrium near the orifice of the inferior vena cava. It was almost completely symmetrical with the right and received a complete azygos vein.

The anomaly is explained as (a) failure of the precardinal anastomosis to form, (2) persistence of the entire left anterior and common cardinal veins and left horn of the sinus venosus, and (3) persistence of the proximal part of the left posterior cardinal which with the left supracardinal forms the left azygos vein. Morphological and clinical significances of the anomaly are discussed.
Cyclical changes in and significance of lipids and acid phosphatase activity in the seminiferous tubules of the rat testis
Authors: Niemi Mikko , Kormano Martti
Published: February 2005

The distribution of tubular lipids and acid phosphatase activity was studied in the rat testis and in the ductuli efferentes. The results were referred to the stage of the cycle of the seminiferous epithelium. The significance of the lipids and phosphatase of the ducts was tested in animals, where excretory ducts were separated from testis for 30 to 40 days.

During the acrosome phase of the old generation of spermatids the lipids first made their appearance in the cytoplasm. During the subsequent stages of the cycle (II to VIII) both the amount of lipids and the intensity of the acid phosphatase activity gradually increased, reaching a maximum in the cytoplasmic “split‐offs” of the mature sperm at stage VIII. Most of the lipids, together with phosphatase‐positive cytoplasmic granules were discarded with the spermatozoa, but a small proportion underwent phagocytosis by the Sertoli cells. During stage IX both lipid‐ and phosphatase‐positive particles moved to the periphery of the tubules as their number in the basal cytoplasm of the Sertoli cells rapidly increased. Through the stages IX to II a gradually diminishing amount of lipids and acid phosphatase activity was seen forming a peripheral ring in the tubules. A temporary rise in the Sertoli cell phosphatase activity took place at the time when the nuclei of the maturing spermatids were deep in the seminiferous epithelium (stages IV and V).

Lipid droplets associated with acid phosphatase activity were present in the epithelium of ductuli efferentes of intact rats. Ductectomy caused a complete disappearance of the epithelial lipids. Simultaneously, cysts filled with degenerating spermatozoa and abundant lipids formed on the cut surface of the testis. It is concluded that the main part of the residual cytoplasm of the spermatids forms an apocrine secretion which is presumably absorbed in the ductuli efferentes and in other parts of the excretory duct system.
Studies of the nerve growth factor in submandibular glands of female mice treated with testosterone
Authors: Goldstein Milton N. , Burdman José A.
Published: February 2005

The effect of testosterone propionate administration on the quantity and localization of a nerve growth protein was studied in the submandibular glands of adult female Swiss mice. Testosterone treatment for 14 to 24 days resulted in an increase in the quantity of a nerve growth‐promoting protein approaching those levels found in normal untreated adult male Swiss mice. The nerve growth‐promoting protein was localized by immunofluorescent techniques in the cytoplasm surrounding the zymogenic granules of the serous tubular portions of the submandibular glands in both control and treated animals. The role played by the submandibular gland in the synthesis or storage of this factor is discussed.
The Specificity of the hair papilla in the rat
Authors: Butcher Earl O.
Published: February 2005

A flap of skin on the dorsum of Long‐Evans rats under anesthesia was turned back, the panniculus was excised and hair bulbs in the growing stage with the enclosed papillae were removed with scissors from a 0.5 cm square area. The flap was returned to its original position and the cut edges were sutured. Depapillated areas were biopsied at intervals following the operation, fixed in acetone and histologically prepared to study the distribution of alkaline phosphatase, glycogen changes, growth and differentiation.

The hair recedes soon after the operation and is surrounded by the outer sheath cells, some of which remain below the receding hair as an epithelial strand. The latter begins growth and elongation 5–6 days after the operation. Differentiation follows and a fragile hair is formed, but the bulbs seldom have a papilla.

The connective tissue in the subcutaneous area apparently cannot be stimulated or does not have the potentiality to become a papilla. Since only a fragile hair is produced by the depapillated follicle, the papilla is very important for the growth of the hair. These observations indicate that the papilla is endowed with special potentialities or has a specificity.
Evolutionary change in the primate wrist and inferior radio‐ulnar joints
Authors: Lewis O. J.
Published: February 2005

The joints at the junction of the forearm and hand are described in a number of Primates, including Man. It is shown that the original lower articular extremity of the ulna recedes from its primitive articulation with the triquetral and pisiform to become the ulnar styloid process, while a neomorphic ulnar head is elaborated entering into a new synovial inferior radio‐ulnar joint. The lower capsule of this joint becomes the triangular articular disk. In the anthropoid apes a meniscus (with a laterally‐directed concave free border bounding the ulnar styloid) develops in the interval between the receding ulna and the carpus. In gibbons this meniscus presents a lunula (os Daubentonii) which is also present in the human fetus as a transient cartilaginous nodule often erroneously homologized with the os intermedium. The upper articular surface of the human wrist joint is formed by the radius, the triangular articular disk and the homologue of the ape meniscus. Between the two latter components is an aperture, similar to that of apes, leading into a pea‐sized diverticulum of the wrist joint — the pre‐styloid recess. The mechanism of the evolution of new synovial joints is discussed.
The epithelial origin of the lymphocytes in the thymus of the embryonic hamster
Authors: Ackerman G. Adolph , Knouff Ralph A.
Published: February 2005

Detailed cytological studies of serial sections have been performed on 85 golden hamster embryos ranging between 9 and 16 days (4–27 mm) of embryonic development.

Sequential cytological changes in the development of the thymus of the hamster into an active lymphocytopoietic organ indicate that lymphoblasts develop by the gradual proliferation and transformation of “undifferentiated” epithelial cells comprising the primordial thymus. The “undifferentiated” epithelial cells undergo two distinct lines of differentiation during early development of the thymus: into lymphoblasts and into stellate reticular‐epithelial cells which form the organ parenchyma. Transformation, both of lymphoblasts and reticular‐epithelial cells begins during the eleventh day of development prior to the separation of the thymus and parathyroid.

That the lymphoblastic and lymphocytic elements appearing in the embryonic thymus of the hamster are of epithelial rather than mesenchymal derivation is indicated by the following: (1) the absence of lymphocytes, lymphoblasts and hemopoietic activity in the connective tissue surrounding the embryonic thymus before and during the period of initial lymphoblastic formation; (2) the presence of a continuous basement membrane surrounding the developing thymus; (3) absence of cells passing through the basement membrane during this phase of development; (4) the absence of vascularity or vascular invasion of the thymus until after the appearance of lymphoblasts in the thymic parenchyma; (5) the demonstration of a sequential series of morphological transitions between “undifferentiated” epithelial cells and lymphoblasts and (6) the subsequent homoplastic proliferation and maturation of the lymphocytic elements from lymphoblasts in the developing thymus.
The relation between nerve fiber number and limb regenerative capacity in the lizard, Anolis
Authors: Zika Jocelyn , Singer Marcus
Published: February 2005

The present work provides some quantitative evidence for the view that the inability of the lizard's limb to regenerate is due to an insufficiency of nerve fibers. The number of fibers per unit area of the amputation surface of the lizard's forelimb is approximately one‐half that reported for the limb of the salamander, capable of regeneration. It is known that when the number of fibers in the salamander's limb is reduced to about half its normal value, regeneration does not occur in about 50% of the animals. The possibility is also discussed that the lizard's limb, in addition to being less innervated than that of the salamander, is also more refractory in its growth response to the nerve. Finally, the comparative poverty of innervation of the lizard's limb relative to that of the salamander suggests that the evolutionary trend in the vertebrate series toward elaboration of central nervous mechanisms was accompanied by a decline in richness of peripheral innervation.
An anomalous arrangement of the flexor musculature of the forearm and hand
Authors: Dahlgard Daryl L. , Kauth Gerald E.
Published: February 2005

During a routine dissection, an anomalous arrangement of the flexor musculature of the hand was discovered. This bilateral anomaly included a deficient superficialis tendon to the index finger and the little finger and an absence of the fourth lumbrical muscles. The deficiency of the sueperficialis tendons to the index fingers was compensated for, however, by an anomalous muscle in each palm.

The literature was searched both for related cases and for embryologic and phylogenetic background with which to explain the presence of this unusual combination of anomalies.
The fine structural localization and selective inhibition of nucleosidephosphatases in the rat adrenal cortex
Authors: Penney David P. , Barrnett Russell J.
Published: February 2005

Fine structural localization of enzymes hydrolyzing nucleoside phosphates in the rat adrenal cortex has been determined, and the selective inhibition of those enzymes exhibiting intracellular localization has been effected. Glutaraldehyde‐fixed adrenocortical tissue was incubated in a medium which contained a nucleoside mono‐, di‐ or triphosphate of adenosine, inosine, guanosine, or cytidine as substrate. Intracellular enzymatic activity was exhibited when one of three nucleoside phosphate substrates was employed. When IDP was used, final product of enzymatic activity was found on membranes of the endoplasmic reticulum, Golgi cisternae and intramitochondrial microvesicles. Final product was localized on the membranes of the endoplasmic reticulum and certain mitochondria when ITP was used. With GTP as substrate, activity was primarily localized on mitochondrial microvesicles and agranular endoplasmic reticulum, with no Golgi involvement noted.

The phosphatases for which intracellular localization was determined exhibited four different sites of activity: (a) agranular endoplasmic reticulum, (b) microvesicles within mitochondria, (c) nuclear membrane, and (d) subendothelial and/or intercellular spaces with occasional involvement of the plasma membrane. When nicotinamide was added to the incubation media, intracellular phosphatase activity was inhibited. Extracellular enzymatic activity was unaffected by nicotinamide. The possible mode of action of nicotinamide in enhancing steroidogenesis and inhibiting intracellular phosphatase activity is discussed.
The hemo‐chorial mouse placenta
Authors: Kirby D. R. S. , Bradbury S.
Published: February 2005

The placental barrier of the mouse was examined by light and electron microscopy and found to be of the hemo‐chorial and not of the hemo‐endothelial type, as had been previously suggested. The suspected immunological function of the trophoblast is briefly reviewed, and attention drawn to the recent reclassification of the shrew placenta.
Olfactory bulb projections of the rat
Authors: White Lowell E.
Published: February 2005

Ten rats with lesions in the olfactory bulb were used in this study. Degenerating fibers were followed by the Nauta‐Gygax silver impregnation technique and terminal changes were evaluated by the original Nauta technique. In these animals degenerating fibers can be traced into the lateral olfactory tract with projections to the olfactory tubercle, the fiberarchitectonic subareas of area 51 (with relative sparing of 51d), lateral olfactory nucleus, anterior amygdaloid area, cortical amygdaloid neucleus, medial amygdaloid nucleus and basomedial amygdaloid nucleus. Evidence for a projection to the lateral ventral entorhinal area is noted in all animals. No changes are noted in subiculum, hippocampus and stria terminalis; nor in the central, baso‐lateral or lateral amygdaloid nuclei.
The anatomy and function of the contents of the human tarsal sinus and canal
Authors: Cahill Donald R.
Published: February 2005

The ligaments of the tarsal sinus and canal, including the roots of the inferior extensor retinaculum, the cervical ligament and the ligament of the tarsal canal, have been restudied and their function has been correlated with the movements of inversion and eversion. The ligaments are extracapsular and their attachments are somewhat more complex than previously reported. A band of fibers, heretofore undescribed, has been designated as the “oblique talocalcaneal band.” It passes from the calcaneal attachment of the intermediate root of the inferior extensor retinaculum to join the talar attachment of the ligament of the tarsal canal.

The ligament of the tarsal canal averages 5.6 mm in width and 1.6 mm in thickness compared with the cervical ligament which is 11.6 mm wide and 2.8 mm thick. The axis of talocalcaneal movement passes between the articular surfaces of the talocalcaneonavicular and subtalar joints and, as a consequence, these articulations move in directions opposite to one another in inversion and eversion. Direct observation during passive movement indicates that the cervical ligament limits inversion whereas the ligament of the tarsal canal plays little or no role in limiting either inversion or eversion. The ligament of the tarsal canal appears to maintain apposition of the talus and calcaneus in all positions.
Electron microscopic observations on monoamine‐containing brain stem neurons in normal and drug‐treated rats
Authors: Lenn Nicholas J.
Published: February 2005

Brain stem nuclei whose neurons contain monoamines have been surveyed by Dahlström and Fuxe ('64), using a fluorescence histochemical method. There was a diffuse fluorescence of the perikarya in these regions, with increases in catechol amine and 5‐hydroxytryptamine fluorescence after administration of dihydroxyphenylanine and pargyline, respectively. The perikarya of the locus coeruleus, nucleus dorsalis raphes and the region lateral to the nucleus interpeduncularis where numerous monoamine‐containing neurons are located, have been examined by electronmicroscopy and found not to be distinctive, except for small numbers of granular vesicles scattered in the cytoplasm. When three normal rats were compared with three given pargyline, no significant increase in the number of granular vesicles occurred in the nucleus dorsalis raphes. Thus the small number of granular vesicles does not seem to correlate with the diffuse fluorescence of these perikarya, nor does the small change in the number of granular vesicles seem to correlate with the profound increase in fluorescence after pargyline administration. It is therefore concluded that the monoamine contained in these perikarya is not located exclusively, if at all, in vesicles either of the granular or nongranular type.
The anterior choroidal artery: An anatomical study of its area of distribution
Authors: Herman L. H. , Fernando O. U. , Gurdjian E. S.
Published: February 2005

The morphology and the structures supplied by the extraventricular segment of the anterior choroidal artery was studied in 22 human brains. The pertinent arterial sections were injected with a gelatin‐india ink mixture and the brains serially sectioned and cleared after formalin fixation. The area of distribution of the anterior choroidal artery varied widely.

There is good supply to the globus pallidus, the posterior and retrolenticular portions of the internal capsule, the cerebral peduncle, the optic tract and the lateral geniculate body. A lesser supply is furnished to the genu of the internal capsule, thalamus, hypothalamus, subthalamus, and amygdala.
Microradiography of the rabbit's hepatic microcirculation. The similarity of the hepatic portal and pulmonary arterial circulations
Authors: Reeves John T. , Leathers James E. , Boatright Carl
Published: February 2005

Examination of microradiographs of liver indicate that the hepatic arteries supply the richly anastomosing arterial plexus around the biliary ducts. This arterial plexus supplies the portal veins directly and the peripheral hepatic sinusoids. Arterial “boosters” penetrating deep within the lobule were not seen. Hepatic veins receive sinusoids at irregular angles and frequent intervals, whereas portal veins distribute flow through short right angle inlet venules spaced at greater intervals. Pulmonary arteries also distribute flow to capillaries through short right angle precapillaries and pulmonary veins receive capillary drainage at irregular angles and frequent intervals. The location of capillary beds of both liver and lung only 10 to 30 μ from inflow channels appears “ideally” suited for circulations of low vascular resistance. The analogy of liver and lung relates biliary system to airway, hepatic artery to bronchial artery, portal vein to pulmonary artery, hepatic vein to pulmonary vein and ductus venosus to ductus arteriosus. In particular, should the pulmonary artery be considered a “pulmonary portal vein”.
Periosteal appositional bone growth from age two to age seventy in man. A tetracycline evaluation
Authors: Epker Bruce N. , Frost Harold M.
Published: February 2005

Periosteal appositional bone formation in human ribs was analyzed. Tetracycline labels deposited in vivo reveal that in human ribs there can be continued apposition of periosteal bone after age 20, which decreases in amount with advancing age but is still present in the seventh decade.
The leydig cell in larval amphibian epidermis. Fine structure and function
Authors: Kelly Douglas E.
Published: February 2005

The large, presumably mucus and/or fluid secreting cells of Leydig have been studied in the epidermis of the newt, Taricha torosa, by light and electron microscopy. Mitotic activity in visibly differentiated Leydig cells results in their increasing numbers so that by mid‐larval stages they comprise the major cellular component of tailfin skin. Subsequently, the number of these cells diminishes as the epidermis thickens; their final disappearance coincides with metamorphosis and epidermal cornification. During the course of larval life, clear vesicles within Leydig cell cytoplasm accumulate granular material and, in time, assume the morphology of typical mucous aggregates. Concomitantly, the cytoplasm progressively becomes clear in appearance and nearly devoid of organelles.

The surface of larval skin is normally provided with a thin mucous coat by continual production on the part of apical epidermal cells. When this surface is exposed to air, observation over a period of time reveals that the outer mucous coat hardens rapidly. There is no indication that additional fluid or mucus is provided to the drying surface from Leydig cells. Rather, light and electron micrographs of epidermis after various degrees of desiccation suggest that Leydig cells do respond to drying, but do so by adding fluid and perhaps mucous material to subsurface, extracellular compartments of the epidermis. The concept that Leydig cells provide an internal fluid reserve is discussed in relation to epidermal development and prevailing physiological and structural evidence bearing on intercellular compartments.
Connections between the T system and sarcoplasmic reticulum
Authors: Walker Sheppard M. , Schrodt G. Randolph
Published: February 2005

Electron micrographs of rat gastrocnemius muscle fibers show membrane‐like dense structures traversing the space between the transverse system (T) and the terminal segments of sarcoplasmic reticulum (R). The periodicity of the structures, viewed in longitudinal sections of triads, varies from 150–250 Å. The distance between apposed membranes of T and R is 80–100 Å at the level of the dense structures between T and R. The distance is slightly greater than 100 Å at the level of less dense areas which alternate with the dense structures. The scalloped appearance of the R membrane, associated with differences in distance between T and R when the levels of dense structures and less dense areas are compared, leads to the suggestion that a holding force might be exerted by the dense structures. Such a holding force would support the view that the membrane‐like dense structures are indeed connections between T and R. If membrane‐like connections between T and R completely surround the less dense areas it is possible that a “physiological tight junction” conductive to electrotonic spread of current might exist between apposed membranes of T and R.
Concealed umbilical hernia: Papez's concept of so‐called paraduodenal hernia
Authors: Laslie Michael , Durden Charles , Allen Lane
Published: February 2005

Two cases are described in which enormous bloodless peritoneal sacs occupy the abdominal cavity and enclose the small intestines. Back of the sac the colic arteries and veins are in normal anatomical position. The inferior mesenteric vein has been converted into a fibrous cord with resulting reversal of venous return from the hindgut into the hypogastric vein. These cases conform to Papez's concept of the so‐called paraduodenal hernia: the peritoneal sac is derived from the embryonic umbilical peritoneal cavity. The authors suggest that most, if not all large intraperitoneal sacs, the so‐called paraduodenal hernias, are derived from the embryonic umbilical peritoneal diverticulum.
Distribution of cholinesterase within the sinus node and AV node of the human heart
Authors: James Thomas N. , Spence Caryle A.
Published: February 2005

Distribution of cholinesterase within the sinus node, AV node and His bundle of the human heart was studied utilizing acetylthiocholine as the substrate. Cholinesterase is present in large amounts in the conduction system tissue, much smaller amounts in right atrial myocardium and was not observed in ventricular myocardium. The sinus node artery was devoid of cholinesterase, as was the sarcolemma and nucleus of cells in the conduction system. Cholinergic nerve endings stained the most heavily of all tissue studied and were more numerous in the sinus node than the AV node. Stellate‐shaped cells previously suggested to be the pace‐making site in the sinus node were found to contain abundant cholinesterase. Fibers in the AV nodal bypass tract, which lies between the AV node and right atrial endocardium, also contain cholinesterase. Within individual cells of the sinus node cholinesterase could be identified within myofibrils, with periodic absence in the linear staining most likely corresponding to the Z bands. Other organelles within the cells also contained cholinesterase, but their precise definition was impossible with the present technics. Possible functional significance of these histochemical observations were discussed.
An electromyographic analysis of certain movements and exercises. I. some deep muscles of the back
Authors: Pauly John E.
Published: February 2005

Pairs of fine wire electrodes were inserted by means of hypodermic needles 1 cm apart into the semispinalis capitis, semispinalis cervicis, spinalis, longissimus, iliocostalis lumborum, main mass of the erector spinae between the ilium and the twelfth rib, the multifidus and glutenus maximus of 20 young men and women.

Each pair of electrodes was connected to an EMG integrator coupler in an 8‐channel recorder. Because the integrated electromyogram is displayed as a deviation from the baseline proportional to the strength of the muscle contraction, it was possible to appraise the relative contributions made by different muscles to any given movement or exercise. By this method simultaneous recordings were made from the muscles while the subjects flexed, extended, hyperextended, abducted and adducted the trunk from the orthograde position; walked on a treadmill, lifted weights; and performed certain exercises recommended by the President's Council on Adult Physical Fitness. Many exercises were compared, and the best ones were selected on the basis of the strength of the contractions they produced. The best exercises for strengthening the deep muscles of the back were those that involved hyperextension of the back from the prone position.

Contrary to current opinion, the erector spinae is not active during abduction or adduction of the trunk from the orthograde position if the body is maintained in the frontal plane.

The integrated electromyogram is an excellent tool for the evaluation of exercises.
The anatomy of the cervicothoracic arterial system in the bottlenose dolphin (Tursiops truncatus) with a surgical approach suitable for guided angiography
Authors: Galliano R. E. , Morgane P. J. , McFarland W. L. , Nagel E. L. , Catherman R. L.
Published: February 2005

Anatomical dissections on the cervicothoracic arterial system of the bottlenose dolphin (Tursiops truncatus) have been carried out as a necessary stage preceding certain physiological investigations in this animal. It is essential to have access to large blood vessels in these investigations, and the lack of superficial blood vessels suitable for catheterization in this species has required that a surgical approach to deeper vessels be developed. We have described a surgical technique for exposure of the A. carotis externa and V. jugularis externa and have used this method to introduce angio‐catheters into both of these vessels. By these means we have been able to carry out hemodynamic, blood chemistry, and angiographic studies with successful recovery of the animals. These investigations, anatomical dissections on normal animals, and studies of vinylite vascular casts have delineated many specialized features of the cervicothoracic vascular systems in the dolphin.
Electron microscopic observations of pericytes of small blood vessels in the lungs and hearts of normal cattle and swine
Authors: Epling Glenwood P.
Published: February 2005

In an electron microscopic study of lungs and hearts from cattle and swine, filament‐containing cells were observed to extend through the basement membrane and form contacts with endothelial cells of capillaries, arterioles, and venules. It is suggested that these may be cells of Rouget and that they may be of considerable functional significance.
The effects of ultracentrifugation on the mammalian erythrocyte
Authors: Beams H. W. , Kessel R. G.
Published: February 2005

Pieces of rat spleen were subjected in an air turbine ultracentrifuge to a force of approximately 400,000 times gravity for periods varying from one‐half to one hour. They were immediately fixed for study with both the light and electron microscopes. Stained preparations show a displacement and stratification of materials within the erythrocytes. The stratified layers are probably components of the stroma which differ in their relative specific gravities and staining reactions. The chemical nature of the different layers has not been determined, but their relative volumes are indicated by the dimensions of the layers.

Electron micrographs show some effects of the ultracentrifugation such as stretching and the concentration of more dense material in the centrifugal halves of the cells, but a clear cut demonstration of the three stratified layers observed in Mallory's triple stained preparations is not evident. Except for the plasma membrane and a finely granular interior of the erythrocyte, little other structure is revealed within it, especially concerning the nature and distribution of the stroma.
Ultrastructural studies on early elastogenesis
Authors: Fahrenbach W. H. , Sandberg L. B. , Cleary E. G.
Published: February 2005

Elastogenesis in the ligamentum nuchae of the fetal calf commences with the extracellular deposition of hollow‐appearing filaments, 130 Å in diameter, showing a banding pattern consisting of alternating segments, 50 Å and 130 Å long, respectively. Similar filaments are found in the crude extract of the ligament. Mature elastin forms within these masses of filaments and displays an internal, branching tangle of 30 Å filaments. Elastogenesis is accompanied by a high level of cellular activity involving acanthosomes, which have been interpreted as a mechanism of secretion of protein‐polysaccharide complexes.
Light and electron microscopy of intestinal ferritin absorption. Observations in sensitized and nonsensitized hamsters (Mesocricetus auratus)
Authors: Bockman Dale E. , Winborn William B.
Published: February 2005

The intestinal absorptive cells of adult hamsters which have been pretreated with intraperitoneal injections of horse ferritin or subcutaneous injections of ferritin‐adjuvant mixture show a marked absorption of this protein when it is introduced into ligated segments of the intestinal lumen for periods up to three hours.

Ferritin is concentrated in the enteric surface coating, intracytoplasmic vesicles in the supranuclear area, and the Golgi apparatus. Large aggregates are localized in macrophages, fibrocytes, and endothelial cells of the lamina propria. Individual molecules are also present in these cells, plasma cells, intercellular spaces and capillary lumens.
Observations on the pilot whale Globicephala melaena: Organweight and growth
Authors: Cowan Daniel F.
Published: February 2005

The organ weights of 55 Pilot whales (Globicephala melaena) of known age, sex and length were determined by direct measurement. These weights were compared with body length and statistical analysis demonstrated a high degree of correlation between non‐endocrine organ weight and body length, and by extension with body weight. Non‐endocrine organs are not significantly related (p>0.1). Graphs demonstrated the essentially parabolic nature of the weight and growth curves.

Statements regarding organ weights in this, and presumably in related species are meaningless unless taken in conjunction with either body length or weight.