bluuebunny/crossref_metadata_2025_split huggingface dataset:
The ultrastructure of the nephrons of the desert rodent (Psammomys obesus) kidney I. Thin limb of henle of short‐looped nephrons
Authors: Barrett J. Michael , Kriz Wilhelm , Kaissling Brigitte , de Rouffignac Christian 
Published: February 2005

AbstractPrevious studies by Kaissling et al. ('75) showed that superficial and midcortical glomeruli of the Psammomys kidney give rise to short nephrons which do not enter the inner medulla. The thin descending limbs (TDLs) of such short nephrons descend into the inner stripe of the outer medulla only within vascular bundles. The TDLs of long nephrons are excluded from these bundles.Transmission EM was used in the present study to examine the ultrastructure of short TDLs in relation to the arterial and venous vasa recta. In the interbundle region of the uppermost outer medulla, proximal tubules of short nephrons give rise to TDLs classified as having Type II (interbundle type) epithelium. Type II is simplified to Type I (bundle type) epithelium where the short TDL enters the vascular bundle. It persists throughout the vascular bundle and continues briefly into the interbundle region until its transition to the distal tubule.Type I epithelium is extremely thin and simple. These cells are poorly inter‐digitated and have simple junctional complexes. An intimate association with the venous vasa recta is seen.Comparison of these data with other micropuncture studies shows that the 4‐fold concentration of urea in the distal nephron is probably correlated with the ultrastructural characteristics of short TDLs and their isolation within vascular bundles. This is augmented by the uptake of urinary urea from the pelvic extensions (Kaissling et al., '75).Thus, the loop of Henle of short nephrons must be regarded as an intrinsic part of the complex multiplier system of the Psammomys kidney.
The ultrastructure of the nephrons of the desert rodent (Psammomys obesus) kidney II. Thin limbs of henle of long‐looped nephrons
Authors: Barrett J. Michael , Kriz Wilhelm , Kaissling Brigitte , de Rouffignac Christian 
Published: February 2005

AbstractLong nephrons are derived from juxtamedullary glomeruli. In their descent through the outer medulla toward the inner medulla, the thin descending limbs (TDLs) of long loops of Henle are consistently excluded from the vascular bundles and occupy the interbundle region. The outer medullary segment of long TDLs (Type II epithelium) is elaborately developed with numerous cellular interdigitations. microvilli, and a cytoplasm well equipped with numerous organelles.The inner medullary segment of these long TDLs is characterized by yet another epithelium that is markedly reduced from its Type II predecessor and is designated as Type III epithelium. It is a very low, flattened epithelium with few cytoplasmic details. In a cross section of the inner medullary TDL, the Type III epithelium appears poorly interdigitated, with only two to four cell processes and their junctional complexes.Shortly before the bend of a long loop of Henle, the epithelium is again altered to one that is well‐interdigitated and better equipped with cytoplasmic organelles (Type IV epithelium). It persists through the actual bend of the loop and throughout the entire thin ascending limb (TAL), until the latter's transition to the distal tubule at the level of the inner/outer medullary border.We conclude that the Type II epithelium of the outer medullary segments of long TDLs in Psammomys is suitably constructed for involvement in energized transport of solutes. The possibility for a similar role in the Type IV epithelium of the bends and TALs is not excluded by our data. However, the Type III epithelium of the inner medullary segments of long TDLs is most suitably constructed for the concentration of its luminal fluids via water extraction. A comparison between these epithelial types and their permeabilities in various species is presented.
Localization of four polypeptide hormones in the saurian pancreas
Authors: Rhoten William B. , Smith Phillip H. 
Published: February 2005

AbstractGlucagon, insulin, somatostatin, and pancreatic polypeptide have been localized in the anolian pancreas using peroxidase‐antiperoxidase immunocytochemistry. The most abundant endocrine cell type contains glucagon. Insulin‐containing cells are the next most numerous. Somatostatin‐immunoreactive cells tend to be localized at the periphery of the islet cords. Pancreatic polypeptide‐containing cells are a minor endocrine component scattered throughout the exocrine pancreas and occasionally within the islet areas. No staining was observed after application of antigastrin serum.
The distribution and endocrine nature of the abdominal paraganglia of adult man
Authors: Hervonen Antti , Partanen Seppo , Vaalasti Annikki , Partanen Matti , Kanerva Lasse , Alho Hannu 
Published: February 2005

AbstractThe paraganglia of adult man were studied using the formaldehyde‐induced fluorescence (FIF) method for histochemical characterization of biogenic monoamines. Microspectrofluorimetry was used to record the emission spectra and fluorescence intensities of the paraganglionic cells. The study of samples from six patients showed that well vascularized paraganglia were widely distributed throughout the retroperitoneal spaces. The paraganglia exhibited strong FIF with the spectral characteristics of monoamines. Treatment with HCl caused an increase in the fluoresoence intensity of the paraganglia and a simultaneous shift of the emission maximum from 480–495 nm. This change suggests the presence of high concentrations of tryptophyl‐containing peptides and is not due to monoamines. The possibility of a dual endocrine function for the paraganglia is discussed.
Innervation of the ventral prostate of the rat
Authors: Vaalasti A. , Hervonen A. 
Published: February 2005

AbstractThe autonomic innervation of the rat ventral prostate was studied in an attempt to evaluate the role of innervation in the normal function of the gland. Specific histochemical methods for both catecholamines (the formaldehyde‐induced fluorescence method, FIF) and acetylcholinesterases (the Gomori‐Koelle thiocholine method) were used. The neuro‐effector contacts were studied by electron microscopy using both 3% glutaraldehyde and 3% potassium permanganate (KMnO4) as fixatives. It was found that the rat ventral prostate receives dual autonomic innervation. Adrenergic fibers, which formed the majority of the nerves, were often seen in close contact with the smooth muscle cells around both the prostatic alveoli and secretory ducts. The non‐adrenergic nerve fibers, which were fewer in number, did not form such intimate contacts with the muscle cells. No direct synapses with epithelial cells were detected.
Histochemistry and ultrastructure of the interstitium of the renal papilla in rats with hereditary diabetes insipidus (brattleboro strain)
Authors: McAuliffe W. Geoffrey 
Published: February 2005

AbstractThe Brattleboro strain of Long‐Evans hooded rats has hereditary hypothalamic diabetes insipidus due to the inability to produce antidiuretic hormone. Animals homozygous for this autosomal recessive trait have extreme polyuria and polydipsia, whereas heterozygotes are less severely affected. Light and electron microscopy were used to study the interstitial tissue of the renal papilla of Brattleboro rats and normal Long‐Evans rats. Staining with alcian blue or colloidal iron revealed that homozygous Brattleboro rats (DI) have greatly reduced quantities of glycosaminoglycans in the papillary interstitium. Heterozygotes showed staining similar but not identical to that of normal rats. The papillary interstitial cells of DI rats lacked the cytoplasmic processes seen in normal rats, and the normal relationship of these cells to the tubular elements of the papilla was absent. Electron microscopy revealed that the papillary interstitial cells of DI rats appeared less active than those of heterozygous or normal rats. In DI rats these cells displayed reduced numbers of lipid droplets and mitochondria, and the Golgi apparatus and rough endoplasmic reticulum were poorly developed. The altered ultrastructure of the papillary interstitial cells may be responsible for the reduction of interstitial glycosaminoglycans in DI rats. Glycosaminoglycans possess properties which may contribute to urinary concentration. It is suggested that the interstitial tissue of the renal papilla is influenced by antidiuretic hormone.
A scanning electron microscopic study of the development of the shoulder, visceral arches, and the region ventral to the cervical somites of the chick embryo
Authors: Yander Gail , Searls Robert L. 
Published: February 2005

AbstractScanning electron microscopy (SEM) was used to investigate the development of the shoulder in the chick embryo. Initially the wing grows on an axis perpendicular to the dorso‐ventral and cranial‐caudal axes of the embryo, but soon begins to grow in a ventral and partially caudal direction. The change in axis of outgrowth occurs while the shoulder forms at the cranial proximal portion of the wing. Analysis of SEM observations, together with an analysis of serially sectioned embryos and photographs of live embryos in ovo has demonstrated that the shoulder continues to grow out on an axis perpendicular to the dorso‐ventral axis of the embryo, while the caudal and distal portions of the wing grow ventrally. The change in axis of outgrowth seems to be due to (1) the formation of the viscera under the wing, (2) the closing of the membrana reuniens to form a continuous sheet covering the viscera under the wing, (3) caudal movement of the duct of Cuvier and the cranial margin of the pleural coelom, and (4) ventral movement of the lateral body fold caudal to the wing. Although the visceral arches undergo major morphogenetic changes during this period, the visceral arches do not appear to have an influence on shoulder development.
Nerve endings in the human prostate
Authors: Vaalasti Annikki , Hervonen Antti 
Published: February 2005

AbstractThe ultrastructure of nerve endings in the human prostate was studied using glutaraldehyde‐OsO4 and KMnO4 fixation. The nerve endings were classified into three categories according to the size of the vesicles and the contents of the synaptic profiles. In addition to the conventional adrenergic and cholinergic axons, a third type of axon profile containing a predominance of large granular vesicles was constantly found. Synaptic contacts were found only on smooth muscle cells. No epithelial innervation could be demonstrated. The functions and possible transmitters of the various types of axon terminals are discussed.
The origin of nuclear bodies: A study of the undifferentiated epithelial cells of the equine small intestine
Authors: Doyle Desmond G. 
Published: February 2005

AbstractDuring an electron and light microscopic study of the equine intestinal epithelium, it was observed that some secretory granules of the undifferentiated crypt epithelium were incorporated into the nucleus during mitosis. A study was made of the chemical nature of the granules, using standard histochemical techniques: PAS‐Alcian blue, Deamination‐PAS, and Ninhydrin‐Schiff reactions. The granules contained a neutral protein‐polysaccharide complex with many terminal amino groups, possibly an antibody (IgA).The intranuclear granules underwent coalescence and degeneration during differentiation. The end‐product was identical with the nuclear bodies seen in other somatic cells and described in the literature. These nuclear bodies were seen in absorptive cells, goblet cells, and Paneth cells; but were not observed in any entero‐endocrine cells.This study shows that the nucleus is capable of isolating and degrading unwanted material, foreign and internally generated, and, further, it gives an explanation for the origin of nuclear bodies, structures that have long been an enigma in cell biology.
Ultrastructural study of tension and pressure zones in a rabbit flexor tendon
Authors: Merrilees Mervyn J. , Flint Michael H. 
Published: February 2005

AbstractThe flexor digitorum profundus tendon of the rabbit hind limb is subject to tensional forces throughout most of its length but, within a localised area which is in contact with the calcaneum and talus, it is subjected to additional compressive forces. This pressure‐bearing area, in marked contrast to the tensional areas, has a fibrocartilage‐like organization and a high concentration of glycosaminoglycans (GAG).Ultrastructural features of the cells, collagen and matrix in the tension and pressure zones are also markedly different, with a full spectrum of transitional characteristics in the junctional region between the two zones. These findings support the concept that the cells in the various regions are sensitive and responsive to changes in physical load.In the tensional zone, elongated cells have extensive cytoplasmic flanges, which may contact flanges of neighbouring cells, and a scalloped cell surface that intimately conforms to the adjacent positively charged and tightly packed collagen fibrils of long periodicity (63 nm) and varying diameters. In the pressure zone, round and clustered fibrocartilage‐like cells, characterized by dense arrays of 11‐nm‐diameter microfilaments and numerous lipid droplets, are surrounded by loosely packed collagen fibrils of short periodicity (53 nm) and predominantly small diameters, and an extensive matrix rich in GAG.It is suggested that these regional morphological variations in the extracellular components result from, and are indirectly the cause of, changes in the cellular synthetic activities which are known to occur in response to changes in the physical environment.
Scanning electron microscopic study of the sacculus and lagena in several deep‐sea fishes
Authors: Popper Arthur N. 
Published: February 2005

AbstractThe ultrastructure of the sacculus and lagena, two otolithic organs involved in audition, was studied in seven species of bathypelagic and mesopelagic fishes representing a taxonomically diverse sampling of Division‐III teleost fishes. The saccular macula in each species had hair cells oriented in four directions, with cells on the rostral part of the macula oriented anteriorly and posteriorly, and those on the caudal end of the macula oriented dorsally and ventrally. The most significant variation from this pattern was in a Gadiform fish, Bregmaceros sp., which also had additional groups of horizontally oriented cells on the posterior end of the macula. The lagenar macula in each species had very similar hair cell orientation patterns, there being dorsally oriented cells on the anterior side of the macula and ventrally oriented cells on the posterior side. The only exception to this pattern was in Ectreposebastes, in which the two groups of cells were oriented towards one another.Significantly, the predominant ciliary bundles on the sensory hair cells of the saccular maculae, and to a slightly lesser degree on the lagenar maculae, were quite similar in almost all species. The bundles had a single long kinocilium and graded stereocilia, the longest of which were almost as long as the kinocilium. This pattern is far less frequently found in shallow water fishes.These data further demonstrate that the hair cells oriented in four directions on the saccular macula may be ubiquitous among all teleost fishes other than the Ostariophysi. The data also lead to the suggestion that the elongate ciliary bundle may be adaptive to certain features of life in deep water.
Mouse uterine glands during the peri‐implantation period: Fine structure
Authors: Given Randall L. , Enders Allen C. 
Published: February 2005

AbstractMouse uterine glands, obtained during the peri‐implantation period of pregnancy, were investigated using light and electron microscopy. From day 4 to day 6 of pregnancy, there was a progressive luminal dilation and an accumulation of dense homogeneous material in the gland lumina. Although numerous large electron‐lucent vesicles were present in the apical portion of the glandular cells on day 4, their number decreased by days 5 and 6 of pregnancy. Dense granules were present along the apical border of many glandular cells on day 6. In addition, there was an increase in the number and more orderly arrangement of RER cisternae by day 6 of pregnancy. Cytochemical studies on days 4, 5, and 6 of pregnancy, using the periodic acid‐thiocarbohydrazide‐silver proteinate method for the ultrastructural localization of carbohydrate material, showed specific staining of the multivesicular bodies and the saccules of the concave surface of the Golgi complex, but not the dilated saccules of the convex surface. Specific staining was also observed over both the luminal material and apical granules present on day 6 of pregnancy.The cytochemical evidence suggests that the secretory product of the uterine glands has carbohydrate components and that carbohydrate material accumulates in the Golgi complex. In addition, the morphological changes observed imply increased secretory activity of the uterine glands during the peri‐implantation period. Thus, the uterine glands must be considered an important source of uterine fluid components during the peri‐implantation period.
Ultrastructural studies on spermatogenesis in a sex‐ratio‐mutant strain of Drosophila simulans
Authors: Ramamurthy Gollu , Alfert Max , Stern Curt 
Published: February 2005

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

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

AbstractPopulations of “synaptic” ribbons (SR) in pinealocytes of the rat pineal gland at various ages from the neonatal period through early adulthood were analyzed morphometrically. Diurnal and nocturnal numbers of SR were small on day one but had increased dramatically by the end of the first week and beginning of the second week. By day 10, numbers of SR had peaked. Thereafter nocturnal numbers of SR demonstrated no significant increases or decreases. However, between days 10 and 19, diurnal numbers of SR decreased precipitously, appearing to have leveled off at the onset of puberty to levels observed in adults. SR were never scarce or absent in any age group studied.The neonatal appearance of large numbers of SR coincides developmentally with the initial sympathetic innervation of pineal parenchyma. Circadian rhythm in numbers of SR begins shortly thereafter. It is suggested (1) that circadian rhythm in numbers of SR is initiated and regulated or modified by sympathetic innervation of pinealocytes containing SR, and (2) that SR formation may be related to the intracellular flow of membrane relative to the transport and release of specific pineal products.
Observations on the hypothalamo‐hypophyseal portal vasculature in the developing human fetus
Authors: Thliveris James A. , Currie R. William 
Published: February 2005

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

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