The Royal College of Surgeons (RCS) rat is the first known animal with inherited retinal degeneration. Despite the fact that the genetic defect is not known, the RCS rat is widely used for research in hereditary retinal dystrophies. This review tries to summarize observations which have been made in the RCS rat and to make an attempt to formulate candidate genes which may the cause for the retinal degeneration in this rat strain. The genetic defect in RCS rats causes the inability of the retinal pigment epithelium (RPE) to phagocytose shed photoreceptor outer segments. In normal rats or humans, this circadian process is regulated by both the cyclic adenosine monophosphate (cAMP) and the calcium/ inositol phosphate systems. The calcium/inositol phosphate system seems to be linked to the phagocytosis receptors which recognize photoreceptor outer membranes to initialize phagocytosis. The cAMP system appeared as modulator of the regulation of phagocytosis. An increase in the intracellular cAMP concentration is an 'off' signal for phagocytosis. In RPE cells from RCS rats many observations have been made which indicate a changed second messenger metabolism concerning both the cAMP and the calcium/inositol phosphate systems. The genetic defect seems to concern a protein which is involved in the initialization of a second messenger pathway. We conclude that the genes coding for the phagocytosis receptor or for proteins which are linked to receptors (for example G proteins) are good candidates for defective genes in RCS rats.
The differentiating cavernous body (CB) of postnatal rabbit penises was examined with a special reference to immunolocalizations for fibronectin (FN) and endothelin-1 (ET-1). At postnatal day 1, the CBs were embedded by an abundance of mesenchymal cells (MCs), and some of them were closely associated with endothelial cells of preexisting capillaries. Our electron micrographs indicated that such MCs are successively incorporated into the capillary endothelium as vasoformative cells. At this period, vascular sprouts of the helicine artery (HA), which were associated with the MCs, arose from the deep penile artery, and the transformation of such cells to endothelial and medial muscle ones was also indicated, and some MCs appeared to differentiate to epithelioid cells in the media. Immunoreactions for FN were preferentially localized in the rough endoplasmic reticulum (rER) and along the plasma membrane of such vasoformative MCs, and on the extracellular matrix components which connect these MCs with sprouts of both growing capillaries and HA. These findings suggest that FN, which is produced in the rER of the MCs, plays a crucial role in the mechanical linkage during the incorporation of vasoformative MCs into these penile vessels. Immunoreactions for ET-1 were preferentially localized on Weibel-Palade bodies in endothelial cells of the HA, implying the involvement of this peptide in the regulation of the local blood flow in this vessel.
In Royal College of Surgeons (RCS) rats with hereditary retinal degeneration loss of retinal pigmented epithelium (RPE) and choriocapillaris is most pronounced in the upper-temporal quadrant. To investigate whether changes in choroidal vasodilative innervation might be involved in the RPE degeneration, we analyzed whole mount preparations of the retina and choroid stained for nitric oxide synthase and for NADPH-diaphorase (d) of 19 dystrophic RCS rats and 24 age-matched congenic controls of different age groups. Density of NADPH-d-positive nerve fibers was quantitatively evaluated in the upper-temporal and lower-nasal quadrant. Our results revealed that even in control animals there were much less positively stained nerve fibers in the upper-temporal than in the lower-nasal quadrant. Nerve fiber density in both quadrants increased for up to 3 months and remained nearly constant throughout life. In the dystrophic animals up to 3 months of age nerve fiber density was similar to that seen in the controls. In dystrophic animals older than 3 months nerve fiber density in the upper-temporal quadrant decreased significantly, whereas density in the lower-nasal quadrant revealed nearly the same values as in the age-matched controls. Decrease of NADPH-d stained nerve fibers in this quadrant occurred prior to the vascular changes in the choriocapillaris. In the retina of RCS dystrophic rats an increase of NADPH-d-positive amacrine cells was found only in 3-month-old animals. Most of these cells were located in the vicinity of irregularly arranged branches of the central retinal artery. In animals 5 months of age and older the number of cells decreased to the same values found in controls, so that we assume that increase of NADPH-d-positive amacrine cells is involved in capillary degeneration or sprouting.
Background: The innervation of skeletal tissues by sensory nerves is poorly understood – especially of nerve fibres which reach into the bony and cartilaginous tissue. Methods: Samples of rat cartilaginous tissues from different locations (knee joint, vertebral column, temporomandibular joint) were fixed by perfusion and decalcified. The distribution of protein gene product (PGP) 9.5-, calcitonin gene-related peptide (CGRP)- and tachykinin (TK)-immunoreactive axons was analysed using fluorescence immunohistochemistry. Results: Nerve fibres were detected in the outer regions of the hyaline cartilage of the knee joint, in the hyaline cartilage of the vertebral body, in the fibrocartilage of the intervertebral disc and menisci, and in the articular disc of the temporomandibular joint. Predominantly, they were found to be CGRP-immunoreactive. Conclusion: The neuropeptidergic innervation of the hyaline cartilage in different locations and the presence of nerve fibres in the fibrocartilage might indicate that in addition to the classical neuronal afferent and efferent pathway these fibres may also mediate trophic actions like tissue adaptation and repair.
The architectonical differentiation in the basolateral nuclei of the human fetal amygdala - with special reference to transient structures - was studied using series of relatively thick Nissl-stained sections. These architectonic features were correlated with the process of migration. Radial glial fibers providing the scaffold of migratory routes can reliably be marked with the aid of antivimentin. In the 5th gestational month a transient feature is conspicuous in the inferior portions of the basolateral nuclei bordering upon the ganglionic eminence (proliferative zone): columnar cell clusters, separated by cell-sparse septa, extend from the poliferative zone to the nuclei. The width of the cell columns vary considerably between the different nuclei. In vimentin immunopreparations fibers are found inside these cell columns. So they most probably reflect clustered migratory streams. Two months later, instead of this merging area between the ganglionic eminence and the amygdaloid nuclei a cell-free capsule envelopes the nuclei and clearly separates them from the ganglionic eminence. Changes in cytoarchitectonics are accompanied by a distinct rearrangement of radial glial fibers. A basket-like arrangement of the vimentin-immunoreactive fibers around the cell columns inside the cell sparse septa is found. Towards the end of pregnancy radial glial fibers gradually vanish. A comparison of Nissl and vimentin preparations reveals that transient architectonic characteristics as visible in relatively thick Nissl sections may be correlated with migrational routes.
The palatal mucosa plays an important role for patients using full dentures. The posterior ridge of the denture is designed to fit on the border between the hard and soft palates; accordingly, this boundary area is of importance when the outline of the denture is designed. In the present study, a rich supply of nerve fibers was found in the mucosa of the boundary area of the hard and soft palates of the rat. An immunocytochemical examination revealed nerve fibers containing protein gene product 9.5 (PGP 9.5), calcitonin gene-related peptide (CGRP), substance P (SP), pituitary adenylate cyclase-activating peptide, vasoactive intestinal polypeptide (VIP), C-terminal flanking peptide of neuropeptide Y (c-PON), or nitric oxide synthase (NOS). Thin nerve fibers with PGP 9.5, CGRP, or SP penetrated into the epithelium, reaching beneath the cornified layer and terminated as free nerve endings. VIP-, c-PON- and NOS-containing nerve fibers were distributed in the connective tissue. Many of the VIP- and c-PON-containing nerve fibers were associated with blood vessels. In addition, nerve fibers containing PGP 9.5, CGRP, SP and c-PON were observed around, and penetrating into, the taste buds in the boundary area.
A number of retinal proteins are phosphorylated by a variety of kinases, resulting in well-known regulatory effects. The identity and role of corresponding phosphatases is less clear. We simultaneously measured the activity of serine/ threonine protein phosphatases type 1, 2A and 2C in bovine retinae. The enzymes were classified according to substrate specificity, divalent cation requirement and the effect of phosphatase subtype-specific inhibitors. The total- and specific activity of phosphatase type 2A was prevalent. Type 2C was 10-fold less abundant. 80% of type 1 and 50% of type 2A and type 2C, respectively, were soluble. An economic purification scheme was developed. We demonstrated the presence of phosphatase isozymes 2Cα and 2Cβ in bovine rod outer segments by enzymatic analysis as well as immunological techniques. The results suggest a yet unknown role of phosphatase type 2C in phototransduction. On the other hand, the immense amount of protein phosphatases found to be soluble – therefore not associated with rod outer segment membranes – points towards participation of these enzymes in the process of visual transduction not considered thus far.
The retroarticular canal has been implicated in compression of the vertebral artery, where it passes over the posterior arch of the atlas vertebra, during extreme rotational movements of the head and neck. The incidence of this retroarticular canal is not known in the South African population. The aim of the present study was to record the incidence and the dimensions of the retroarticular canal in South African white and black adults, aged 20–80 years. In a total of 1,354 atlas vertebrae, 9.8% of sides (264 left and/or right sides) were classified as having complete retroarticular canals, of which 11.7% (31 sides) were right-only, 24.6% (65 sides) left-only and 31.8% (84 left plus right sides) bilateral canals. This incidence did not increase with age and was lower in whites than blacks, with white males having the lowest and white and black females alike having the highest incidence of the canal. Measurements of the retroarticular canal showed that there was no difference between left and right sides. However, the superoinferior diameter was significantly less than the anteroposterior diameter, in all but the right canals in the white female subgroup. This difference in the dimensions of the retroarticular canal will decrease the cross-sectional area of the space available for the vertebral artery passing through it and may compromise blood flow in the vessel.
The anatomy of the iliolumbar ligament (ILL) and the spatial orientation of the transverse process of the L5 vertebra were studied in 62 young black (n = 29) and white (n = 33) men and women during routine autopsy. The aim of the study was to determine possible racial differences in the structure and attachments of the iliolumbar ligament. The present study also investigated the spatial orientation of the transverse process of the L5 vertebra since the ILL has been reported to attach to the transverse process. The measurements of the iliolumbar ligament were carried out with a digital vernier caliper while the transverse process angles were measured with an adjustable protractor. The ligament in black people was made up of a single, markedly longer band compared to white people, where the ligament was made up of two shorter bands. The ILL measured 61.8 ± 1.3 mm in black and 33.2 ± 1.5 mm white men, and in black women 61.3 ± 0.9 mm versus 32.2 ± 1.2 mm in white women (p <0.01). Further, the ILL was markedly wider in black than white subjects (p <0.01). The horizontal and vertical angle also varied greatly between black and white subjects (p <0.01). These are previously unrecognized observations. Albeit unsubstantiated, these findings may have implications for understanding the etiology of various low back stress problems.
The present article opens with a brief summary of the current knowledge of glycoproteins and their medical applications, as compared to the almost complete ignorance of these substances during the first half of the century. The author then relates how he became interested in carbohydrates in the 1950s, and subsequently in glycoproteins. He focuses on the identification of soybean agglutinin as the first known plant protein of this class, to which a widely occurring N-linked oligomannoside is attached, and continues with an account of his work on the coral tree lectin that contains plant-specific N-glycans. Moving at the same time deep into lectin research, he describes the discovery of the crucial role of bacterial surface lectins in the initiation of infectious diseases, thus providing the rationale for the current attempts to use carbohydrates for antiadhesion therapy of such diseases. The article ends with a survey of the author's contribution to spreading wide the knowledge of glycoproteins and of their great importance in biology and medicine.
The angle between the base of the sacrum and its pelvic surface (SA), and the lumbosacral curve (LSC) defined as the anteroposterior distance between the L-1 vertebra and the sacrum were studied in 105 fresh cadavers aged 15-32 years at death. The sample is comprised of 27 black males, 20 black females, 37 white males and 21 white females. Measurements of the SA were made with an adjustable protractor with an accuracy of +/-1 degrees. A new method using a specially designed instrument was developed for taking LSC measurements. A sliding scale that could be moved in the cranialcaudal direction was fitted with a measurement stick which measured the depth of the lumbar and sacral vertebral bodies (ventral to dorsal). The measuring device was placed on the autopsy table above the supine cadaver to measure these depths from the ventral side, The LSC was calculated as the mean difference between lumbar and sacral depths. The SA is smaller in black than in white men (43.6 +/- 3.4 vs. 61.7 +/- 2.1 degrees, p < 0.001). Similarly, black women have a smaller SA than white women (36.0 +/- 2.2 vs. 50.2 +/- 1.9 degrees, p < 0.001). The LSC is also larger in black than white men (9.4 +/- 1.1 vs. 5.1 +/- 0.3 cm, p < 0.001), and black women also have significantly larger LSC compared to white women (13.2 +/- 0.5 vs. 9.2 +/- 0.6 cm, p < 0.001). These data are so far the largest empirical evidence of differences in the SA and the LSC in young black and white cadaver specimens.
Interaction between gametes during fertilization is at least in part regulated by carbohydrate moieties of the zona pellucida (ZP) and carbohydrate binding proteins of the sperm surface. This review focuses on the protein-carbohydrate interactions during the primary binding of the sperm to the ZP in different species. Synthesis, structure and composition of the ZP are summarized. The functional significance of carbohydrate residues of the ZP as sperm receptor is discussed. Sperm surface proteins known to have specific ZP and carbohydrate-binding sites including the mouse β1,4-galactosyltransferase and sp56, the rabbit protein Sp17, a human mannose-binding protein and several members of the spermadhesin family are presented.
When the adult mouse cerebellum is perfusion-fixed with 70% ethanol, paraffin-embedded, sectioned, and the sections are rehydrated, the granular layer wrinkles into an elaborate array of blebs. In the posterior lobe vermis these blebs are seen in both transverse and sagittal sections, are symmetrical about the midline, reproducible between neighboring sections and between individuals, and bear a constant relationship to the Purkinje cell bands as revealed by zebrin II immunocytochemistry. The data suggest that blebs represent individual cytoarchitectonic units and thus that the mouse cerebellum is subdivided into several thousand modules, each comprising >10(2) Purkinje cells and their associated interneurons and glial cells.
During an investigation performed on cadaver forearms in the anatomy department, an unusual insertion of the abductor pollicis longus (APL) muscle together with the extensor pollicis brevis (EPB) muscle was encountered unilaterally in a 40-year-old male cadaver forearm. APL originated from the posterior ulnar surface distal to the anconeus, the adjoining interosseous membrane and middle third of the posterior radial surface. It lay distal to the supinator muscle and close to the EPB, while the EPB arose from the posterior radial surface and from the adjacent interosseous membrane. These muscles were inserted to the palmar side of the base of the first metacarpal bone together. To our knowledge, this variation has not been cited in recent medical literature.
Most behaviours involve complex morphological systems and vice versa morphological systems are used by the organism in many different ways. During evolution and ontogeny changes in kinematics and function of skeletal and muscular systems must be coordinated with changes in their neural control. Neuromotor patterns are sometimes believed to be conserved in evolution, leading to diversification at the level of musculoskeletal design. Vertebrate motor patterns used in feeding are reviewed to examine this hypothesis. Stereotyped behaviour is not necessarily the result of phylogenetic constraints but may also result from the functional demands imposed by the mechanics of the jaw apparatus and the nature of the task performed. Sensory feedback and descending control not only contribute to 'online' control of movement but also shape the development of motor patterns and learning behaviour and indicate a potentially large flexibility. The neural and sensory apparatus that produces this flexibility will be subject to evolutionary modification. In the absence of a demand for flexibility motor patterns may become stereotyped in some species, while they are very flexible in others. To the extent that morphological systems perform independent movements during different behaviours, separate basic motor patterns may be required, which may be coordinated in different ways.
The intercellular adhesion molecule-1 (ICAM-1) is a ligand for the β2 integrin. It is present on the vascular endothelium and plays an important role in cell to cell interaction in lymphocyte recirculation. ICAM-1 is expressed not only on the endothelium but also on other cells, especially lymphocytes adhering to the endothelium, B cells and mitogen-stimulated T cells. To define the functional role of ICAM-1 in lymphocytes, the three-dimensional distribution of ICAM-1 on the surface of lymphocytes in the rat mesenteric lymph node HEV was investigated by immunoscanning electron microscopy. ICAM-1 expression was closely associated with variations in surface structures of lymphocytes, which showed a cap-like structure, membrane ruffles and slender microvilli. ICAM-1 was preferentially localized on the cell surface including membrane ruffles (about 90% of all counted gold particles), but rarely on the microvilli (10%). The results suggest that activated lymphocytes with variations in surface structures demonstrate moderate expression and preferential localization of ICAM-1. This seems to enable a three-dimensional interaction of the microvilli of one lymphocyte with the surface membrane of another cell and might be a prerequisite for cluster formation between them, as seen in antigen presentation.
The retina of the Royal College of Surgeons (RCS) strain of rat, which is being used as an animal model for human retinal degenerations, has been employed in the study of the function of second order neurons. By about the 33rd postnatal day the dendritic branching of isolated bipolar cells is more sparse than in bipolar cells of the normal rat retina, but their GABA channels are as in the normal rat retina. The normally occurring light-induced distal potassium increase has been used as the indicator of the functional competence of second order neurons in the isolated RCS rat retina. These are dependent upon the integrity of ionotropic and metabotropic synapses. At about the 22nd postnatal day MgCl2 enlarges the light-induced distal potassium increase in the young RCS rat retina as in the normal rat retina. It seems that MgCl2 does not block the metabotropic synapses of on-bipolar cells. At about postnatal day 33, at which time the photoreceptors of the RCS rat retina had become severely damaged, the size of this light-induced distal potassium increase was not changed, but it was abolished by MgCl2. This indicates that bipolar cells are still active but that the synaptic function of on-bipolar cells has become vulnerable to MgCl2. The conclusion is that at a time when photoreceptor degeneration is already severe bipolar cells are still active, but that on-bipolars, mainly rod bipolar cells, have some functional deficit.
In the present work, high-field magnetic resonance imaging (HF-MRI) was applied to study the developing human brain paying particular attention to the structures of interest in pathology of malformation. The aim of the work was to evaluate the possible application of HF-MRI to the analysis of brain development in the absence of some limits of conventional histological technique. Seven formalin-fixed human fetuses of 50, 65, 70, 85, 110, 116 and 125 mm crown/ rump length (corresponding to a gestational age ranging from 10 to 16 weeks) were examined in an imager-spectrometer equipped with a 4. 7-tesla horizontal magnet with a 33-cm bore. In the brain of all the fetuses the telencephalic, mesencephalic and rhombencephalic vesicles were recognizable and an easy quantitative evaluation of the brain curvatures in the absence of distortion due to dissection was possible. Comparing fetuses at different gestational ages, the spatial modification of the different vesicles was evident. In fetuses at 16 weeks of gestational age, stratified compartments of the telencephalic wall were evident. The germinal zone and the cortical plate were visible: the germinal layer was identifiable as a hypointensity in the periventricular area. The subplate zone and the intermediate zone emitted a strong intensity signal. Our study demonstrates that HF-MRI can contribute to the study of the complex developmental events in the human brain from the 10th to 16th week of gestational age in a submillimetric scale of resolution. This technique can provide information about the morphology of the encephalic vesicles and their relations with the bone cavity that cannot be obtained with conventional methods and may be a useful adjunct to histological techniques.
The biological importance of oligosaccharide sequences in many different settings is undeniable. Glycan histochemistry has brought together the histological and biochemical approaches and provided insight into the mutual importance of both approaches. The aim of the authors is to take a look at a number of ways in which modern glycohistochemistry contributes to acquiring knowledge about the key role played by carbohydrates in the physiology of vertebrate tissues and human disease. The versatility of lectin and neoglycoconjugate histochemical procedures is emphasized.
Epithelial rests of Malassez and cementoblasts were examined in the rat molars during the early stages of root formation using an antilaminin antibody and/or peanut agglutinin (PNA), and an antiosteocalcin (OC) antibody, respectively. The roots of the first molars were used for study. The antilaminin antibody stained the basement membrane surrounding the epithelial root sheath and epithelial rests. The basement membrane of the epithelial root sheath was continuous, but that of the epithelial rests was discontinuous. The cells of epithelial rests and epithelial root sheath were positive for PNA. The structural characteristics of the epithelial rests were seen in the sections stained doubly with PNA and the antilaminin antibody. The cells of epithelial rests were fibroblast-like and formed a fine mesh in 2-week-old rats. In 3-week-old rats, the epithelial rests were also present at the coronal half of root surface, showing typical cell cords, but were not present at the apical part of the root surface where the cellular cementum covered the root dentin. At the root apex of 3-week-old rats, the cells of epithelial rests forming fine meshes were seen near the epithelial root sheath. The anti-OC antibody stained cementoblasts lining acellular and cellular cementum. The sections doubly stained with the anti-OC and the antilaminin antibodies or PNA further revealed the close relation between epithelial rests and cementoblasts. The OC-positive cells lining acellular cementum or dentin were localized very close to the epithelial rests. In contrast, the OC-positive cells lining cellular cementum did not show close association with the epithelial cells, except the cells located most apically where the basement membrane of the epithelial root sheath is disrupted and the initial cellular cementum begins to be formed. The present results suggest that the epithelial rests and/or the discontinuous basement membrane of them may have a role for the acellular cementum formation at least in the early stage of root formation.
