Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P50583 (asymmetrical)
 12,197 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A case control study was designed to determine the risk factors for the reinfection of Swiss specific pathogen-free (SPF) pig herds with enzootic pneumonia. Detailed housing, management and environmental data were collected from 42 case farms and 50 control farms by means of a questionnaire. Factors with a significantly asymmetrical frequency distribution among the two groups were considered to be possibly associated with reinfection; they included the distance to the nearest non-SPF pig herd, the size of that herd, the density of the pig population in the area, the distance to the next road regularly carrying pig transporters and differences in topography. The results tended to support the hypothesis of the airborne transmission of enzootic pneumonia. Using a formula considering the main risk factors, it was possible to classify farms as high or low risk with an 84 per cent specificity and 74 per cent sensitivity.
Vet Rec 1992 Dec 05
PMID:Risk factors for the reinfection of specific pathogen-free pig breeding herds with enzootic pneumonia. 147 97

Several radiographic techniques for estimating bone cross-sectional geometric properties of mandibular corpora are compared. A hollow asymmetrical model significantly improves estimates compared to solid or hollow symmetrical models that have been used in previous studies. Using this model, biplanar radiographs can give sufficiently accurate information of the amount and distribution of cortical bone in a section given relatively regular subperiosteal and endosteal perimeters.
Anat Rec 1992 Jan
PMID:Use of biplanar radiographs for estimating cross-sectional geometric properties of mandibles. 153 62

Substance P (SP) is a non-opioid peptide that generates a potent analgesia when injected into the periaqueductal gray matter (PAG). The aim of this study was to investigate the fine neuronal structures and synaptic circuits involved in SP action in rats by means of electron microscopy, using immunocytochemical (ICC) pre-embedding methods. A conventional ultrastructural study, carried out to interpret the ICC data correctly, shows small sized nerve cell bodies with a high nucleus-cytoplasmic ratio; absence of an extensive granular endoplasmic reticulum; and few axo-somatic contacts having symmetrical and asymmetrical junctions in equal proportions. The large neuropil is characterized by numerous thin unmyelinated axons and axo-dendritic synapses mainly showing pleomorphic vesicles and asymmetrical junctions. The ICC analysis showed moderately labeled nerve cell bodies with the same structural, synaptic, and dimensional features as the negative cells. In the neuropil SP immunoreactivity is shown by dendrites, synapses, and thin elements which are unidentifiable structurally. No SP terminals synapsing on SP nerve cell bodies were found and only occasional SP light labeled terminals synapsing on negative perikarya were seen. The SP boutons generally have pleomorphic vesicles and asymmetrical junctions. On the basis of these data a possible excitatory activity of PAG SP synapses could be hypothesized. This activity would take place on postsynaptic neurons generally at a dendritic level. Our ultrastructural findings give support to an excitatory role carried out by SP neurons of the PAG, as suggested by the role of PAG circuitry on spinal nociception.
Anat Rec 1990 Nov
PMID:Ultrastructure of substance P immunoreactive elements in the periaqueductal gray matter of the rat. 170 83

The chicken ultimobranchial glands are richly supplied with nerve fibers originating from both the main trunk of the vagus nerve and its branch--the recurrent laryngeal nerve. C cells immunoreactive for calcitonin were invariably found in the large nerve bundles distributed throughout the ultimobranchial glands. In addition, these cells were often present within the distal vagal ganglia and the recurrent laryngeal nerves. The frequency of occurrence and the pattern of distribution of the C cells in the distal vagal ganglia and the recurrent laryngeal nerves were determined in chickens of various ages by means of an immunoperoxidase method with anticalcitonin and antineurofilament antisera. The left and right sides of the ultimobranchial region were asymmetrical. The left ultimobranchial gland was in close contact with the vagus nerve trunk, especially with the distal vagal ganglion, but it was separated from the recurrent laryngeal nerve. The right gland contacted the recurrent laryngeal nerves, its medial edge being frequently penetrated by the nerve, but the gland was separated from the distal vagal ganglion. On the left side, C cells were found in 25 out of 39 distal vagal ganglia but they were not distributed in the recurrent laryngeal nerve. On the right side, the cells were present in 28 out of 43 recurrent laryngeal nerves but absent in the distal vagal ganglia. The results indicate that the C cells secreting a hormone calcitonin can enter into nerves, but their occurrence is restricted to the nerves in close proximity to the ultimobranchial glands. Electron microscopic studies revealed that C cells in the nerves received numerous axon clusters enveloped with Schwann cell cytoplasm. Naked axons regarded as axon terminals were found in direct contact with the surface of C cells. They were mainly composed of efferent-type nerve endings showing the accumulation of numerous small clear vesicles and a few large dense-cored vesicles. In addition, C cells were partly covered with the long cytoplasmic processes of Schwann cells and were also in contact with the Schwann cell perikarya. The C cells in nerves appear to be controlled by neural stimulation.
Anat Rec 1989 May
PMID:Occurrence of calcitonin-positive C cells within the distal vagal ganglion and the recurrent laryngeal nerve of the chicken. 272 15

Recent biochemical and morphologic evidence supports the concept that hypertrophic chondrocytes of growth plate cartilage are fully viable cells that play a major functional role in controlling endochondral ossification. However, events associated with chondrocyte death remain unknown. In this study we assess the viability of terminal hypertrophic chondrocytes in situ in an organ culture system viewed simultaneously with rectified Nomarski interference contrast optics and with vital staining under fluorescence optics. Second, we use two methods of optimal chemical fixation at the ultrastructural level to define morphologically distinct stages of the terminal hypertrophic chondrocyte, which we interpret as the stages preceding chondrocyte death. An analysis of serial sections at the light microscope level showed that terminal chondrocytes were found, with different probabilities, in three morphologically distinguishable stages. Seventy-five percent of all profiles were fully hydrated cells with an intact plasma membrane making direct contact with the pericellular matrix, a morphology identical to that of living terminal chondrocytes viewed in Nomarski optics. Approximately 1% of terminal chondrocytes, while still in a fully hydrated state, consistently made a direct asymmetrical contact of the plasma membrane with the last transverse septum. In 24% of the profiles, terminal chondrocytes were found as condensed cells that retained their attachment to the last transverse septum. The stages were not characteristic of chondrocytes positioned more proximally in the growth plate. We hypothesize that a condensed morphology eventually characterizes each hypertrophic chondrocyte, and we relate these observations to current hypotheses concerning the mechanism of death of hypertrophic chondrocytes.
Anat Rec 1987 Nov
PMID:Morphologic stages of the terminal hypertrophic chondrocyte of growth plate cartilage. 342 41

Axoglial contacts were observed in an ultrastructural study of the area postrema of the cat. According to the disposition of the electron-dense projections attached to the adjoining membranes these contacts were classified as symmetrical or asymmetrical. The axon profiles contained aggregations of clear vesicles randomly distributed or grouped in cluster adjacent to the electron-dense projections. Dense core vesicles were occasionally seen. The neuroglial profiles were either astrocytic or ependymoglial in nature. The astrocytes showed a clear cytoplasm, polymorphous vesicles, mitochondria, glycogen granules, and bundles of filaments. The ependymal cells, in contrast, had a more electron-dense and granular appearance, tubular structures, irregular vesicular formations, profiles of smooth reticuloendoplasm, and filaments grouped in bundles or isolated in the cytoplasm. The possibility that these contacts might play a role in the chemical transfer from neurons to glial cells is discussed on the basis of existing biochemical data.
Anat Rec 1986 Aug
PMID:Axoglial contacts in the area postrema of the cat: an ultrastructural study. 374 Apr 76

Asymmetry of the human skull in the frontal and basal views has been described previously as a normal feature in adults. However, no investigation has been performed during the fetal period to see when asymmetry first develops. Previous quantitative methods for measuring asymmetry have relied upon defining anatomical points and using geometrical constructions. In the present study image outlines and their centroids (centers of area) were related to each other via a rectangular coordinate reference grid using the technique of morphanalysis. The centroids were shifted to the left relative to the coordinate reference grid indicating a left side expansion. Also the signed area under the cyclical curve, which is zero for a perfectly symmetrical shape, showed a negative shift indicating asymmetry. The cranium was found to be the major site of asymmetry caused by unequal development of the cerebral hemispheres. The asymmetrical development of the temporal lobes caused a greater displacement of the nasomaxillary segment on the left leading to a rotation of the face on the cranium.
Anat Rec 1985 Feb
PMID:Asymmetry of the human skull during fetal growth. 397 88

The ultrastructure of the oral (buccopharyngeal) membrane was examined by transmission and electron microscopy in the anuran, Rana japonica, embryo. The stomodeum is recognizable on the ventral surface anterior to the neural folds as the neural folds are beginning to close (neural tube stage). The stomodeum is gradually enlarged and deepened as development proceeds. At the neural tube stage, the oral membrane is 5-7 cell layers thick and the stomodeal ectodermal cells are cuboidal and the foregut endodermal cells are cuboidal or columnar. Desmosomes and basal lamina could not be found between the ectodermal and endodermal epithelia. The oral membrane gradually thins between the neural tube and hatching stages. At the hatching stage, the oral membrane becomes two or three cell layers thick and each cell is flattened. Many perforations of the oral membrane after hatching and the oral membrane appears "net-like." Necrotic cells occur in the oral membrane and these cells contain many autophagic vacuoles. ACPase-positive lysosomes, Golgi regions, and autophagic vacuoles were present in the oral membrane. At the asymmetrical trunk stage, a large part of the oral membrane disappears and only remnants are left.
Anat Rec 1984 Nov
PMID:The ultrastructure of oral (buccopharyngeal) membrane formation and rupture in the anuran embryo. 652 93

Flatfish are a group of uniquely asymmetrical vertebrates, lying always on one side. This postural control depends on the vestibular receptors of the inner ear. From the most primitive living flatfish, orientations of sensory hair cells in the inner ear were mapped by scanning electron microscopy. The maps of the three otolith organs, the three semicircular cristae, and the macula neglecta (newly discovered here for flatfish) show patterns that are very similar to those in many upright teleosts, particularly perches. Thus, peripheral sensory structure does not require modification for the unusual postural control of flatfish.
Anat Rec 1983 Nov
PMID:Retention of generalized hair cell patterns in the inner ear of the primitive flatfish Psettodes. 665 Aug 79

The freeze-fracture technique was used to study the maturation of the postsynaptic membrane of spherical cells of the anteroventral cochlear nucleus (AVCN) of the developing rat brain. Observations were made at 2-day intervals from birth to 16 days of age. At all ages, the external leaflet (E-face) of the spherical cell membrane has aggregates of particles opposite presynaptic active zones. From birth to 6 days of age, these particle aggregates were found only on dendritic processes, not on the cell body. At 8 days of age, the aggregates were found on small somatic appendages and on the cell body adjacent to somatic appendages. In animals from 10 to 12 days of age, particle aggregates became increasingly common on the cell body. Morphometric analysis demonstrated a decrease in size but not packing density of the particles in the aggregates. These changes in the location and size of the aggregates correspond to the location of asymmetrical synapses seen in thin section material at these same time intervals (Neises et al., 1982). At 14 days the fracture plane no longer followed the postsynaptic membrane at the active zone; instead it shifted to the presynaptic membrane and the postsynaptic specializations were rarely seen. This fracture pattern is typical of adult animals.
Anat Rec 1982 Nov
PMID:A freeze-fracture study of the maturation of synapses in the anteroventral cochlear nucleus of the developing rat. 715 32


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