Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “PROTOPLASM”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,207 records · Page 67Linked to original sources
PubMed1987

[Cutaneous mucinosis].

Clinically, the skin changes observed in a 34-year-old woman were suggestive of the reticular erythematosis mucinosis (REM) syndrome. On palpation, however, the changes suggested the plaque-type REM syndrome. Histologically, broad, well-delineated cell-rich bundles were found with abundant alcian-blue-positive material, together with a lymphocytic infiltrate. In such areas showing close contact with the lymphocytic infiltrate, stellate cells with delicate blue processes and protoplasmic granula predominated. Areas preferentially affected with deposits of mucopolysaccharides in the REM syndrome and its variants were not affected in the case presented. The histogenesis of this hitherto undescribed cutaneous mucinosis is discussed.

Adult↗
PubMed1987

Replica-immunogold technique applied to studies on measles virus morphogenesis.

The replica technique was applied to studies on the dynamic process of measles virus budding on infected HeLa cells. Virus structures were identified by labeling with anti-measles antibodies and protein A-gold. The combination of these two methods enabled us to characterize the sequence of virus budding at the plasma membrane, to localize virus structures on cytoskeletons of infected cells, and to study the influence of Ca2+ ions on virus structures at the plasma membrane. Studies on platinum carbon surface replicas suggest that the process of virus budding is similar to the genesis of cellular microvilli. Replicas prepared from cytoskeletons of infected cells reveal a close association of budding virus with actin filaments composing the outer parts of the networks. Replicas of apical plasma membranes isolated from infected cells show the attachment of viral nucleocapsids to the protoplasmic membrane face of infected cells. These nucleocapsids are not present on membranes prepared from cells treated with calcium and the ionophore A23187. In addition viral cell surface antigens become randomly distributed on these cells. The data suggest that measles virus morphogenesis at the plasma membrane of cultured cells is dependent on the function of the cytoskeleton and may be influenced by Ca2+ ions.

Calcimycin↗
PubMed1988

[Immunohistochemical detection of fibrous astrocytes using an antiserum to glial fibrillary acidic protein in the cerebral cortex in Alzheimer's disease].

Immunohistochemical method was utilized to study the changes of the brain cortical fibrous astrocytes in Alzheimer disease with anti-glial fibrillary acidic protein (GFAP) antibodies. The increased number of fibrous astrocytes was found in the molecular cortical layer and in the deeper ones. Hypertrophied forms of the fibrous astrocytes were found to surround the senile plaques and blood vessels. The increase in the number of fibrous astrocytes in Alzheimer disease is thought to be accounted for by the glial filament accumulation in the protoplasmic astrocytes.

Aged↗
PubMed1985

Membrane assembly in retinal photoreceptors. II. Immunocytochemical analysis of freeze-fractured rod photoreceptor membranes using anti-opsin antibodies.

We have used a cytochemical technique for labeling freeze-fractured tissues (Pinto da Silva, P., C. Parkison, and N. Dwyer (1981) Proc. Natl. Acad. Sci. U.S.A. 78: 343-347) to examine the distribution of immunoreactive opsin in rod photoreceptor membranes. Aldehyde-fixed retinas of African clawed frogs (Xenopus laevis) embedded in a cross-linked protein matrix were frozen and fractured at -196 degrees C, then thawed and labeled with biotinylated sheep anti-cow opsin IgG followed by avidin-ferritin. In thin sections of plastic-embedded retinas, rod outer segment (ROS) disc membranes exposed by fracturing bound specific antibody intensely and relatively uniformly. However, they differed from membranes of the inner segment as well as those of erythrocytes in that protoplasmic face leaflets did not assume an interrupted bilayer appearance and disc exoplasmic face leaflets were apparently lost during thawing. The disposition of opsin immunoreactivity in the cell membrane was highly asymmetric. Although ROS plasma membranes from which discs are elaborated labeled heavily with anti-opsin after cleavage, fractures passing along inner segment plasma membranes bound very little antibody. In cross-fractures exposing inner segment cytoplasm, we found specific labeling of Golgi complex elements, as well as both perimitochondrial and periciliary vesicles. The latter are presumed to be the vehicle shuttling newly synthesized membrane to the ROS for disc assembly. These results suggest that opsin-containing membrane is sorted out within the cell, being transported from synthetic sites to the immediate periciliary zone where localized insertion into the cell membrane takes place. Furthermore, the close correspondence of the present immunocytochemical analysis with the distribution of opsin deduced from prior quantitative freeze-fracture analysis (Besharse, J. C., and K. H. Pfenninger (1980) J. Cell Biol. 87: 451-463) offers the possibility that fracture-label may be generally useful for study of patterned membrane topography in neuronal cells.

Animals↗
PubMed1985

Membrane assembly in retinal photoreceptors. III. Distinct membrane domains of the connecting cilium of developing rods.

To investigate the putative role of the photoreceptor connecting cilium in the delivery of opsin to forming discs and in the maintenance of membrane domains (Besharse, J. C., and K. H. Pfenninger (1980) J. Cell Biol. 87: 451-463), we have studied developing photoreceptors of neonatal rats during the period of initial disc formation using conventional freeze-fracture, immunocytochemistry, and lectin cytochemistry. Specific anti-opsin-binding sites were localized in the distal cilium, the developing outer segment plasma membrane, and at focal sites on the inner segment plasma membrane at all developmental stages examined, including the period prior to the onset of disc morphogenesis. The proximal ciliary shaft generally lacked anti-opsin-binding sites or exhibited them in extremely low density. The distribution of anti-opsin-binding sites corresponded in a general way to the distribution of large intramembranous particles (IMPs) in freeze-fracture replicas like those seen in the rod outer segment (ROS). The proximal zone corresponded in freeze-fracture images to a zone of consecutive horizontal rows of intramembrane particles (ciliary necklaces) and axoneme-membrane cross-linkers. Although protoplasmic face leaflet IMPs similar to those of the distal cilium and outer segment were less abundant in the inner segment and proximal cilium than in the distal cilium and ROS, they were detected in these zones at low frequency. Cytochemistry with concanavalin A and wheatgerm agglutinin revealed the presence of a well developed glycocalyx in the proximal zone. Although opsin binds both lectins, the results suggest heterogeneity among the glycoconjugates of the three membrane domains. Our data define distinct membrane domains of the developing photoreceptor cilium that have important implications for the mechanisms for delivering and sequestering opsin in the outer segment. They also establish that the mechanism of opsin delivery to the distal zone occurs well in advance of the period of disc morphogenesis.

Animals↗
PubMed1988

Effects of age and season on the type and occurrence of sperm abnormalities in Nubian bucks.

Effects of age and season on type and occurrence of sperm abnormalities were examined in semen samples collected from 3 groups of Nubian bucks at ages of 4 to 9 months, 10 to 21 months, and 39 to 50 months. The average total percentage of sperm abnormalities at the onset of puberty (141 +/- 4 days) was 64.6 +/- 14.8% (head, 19.5 +/- 13.6%; middle piece, 17.2 +/- 9.3%; and proximal protoplasmic droplets, 14.6 +/- 10.5%), but this improved rapidly and was reduced to 12.5 +/- 7.5% by 8 months of age (head, 1.9 +/- 4.5%; middle piece, 4.6 +/- 2.8%). Further increase in age, at least up to 4 years, did not reveal a significant effect (P less than 0.05) on the type or percentage of total abnormalities. Similar to age, a comparison of data among seasons did not reveal a significant effect on the type or occurrence of sperm abnormalities in 10- to 21-month-old or 39- to 50-month-old bucks. Seemingly, Nubian bucks started producing good quality semen at 8 months of age, and season did not influence sperm abnormalities.

Aging↗
PubMed1977

Lipid A as the biologically active moiety in bacterial endotoxin (LPS)-initiated generation of procoagulant activity by peripheral blood leukocytes.

Preparations of rabbit or human leukocytes, when incubated with bacterial endotoxins (lipopolysaccharides, LPS) are stimulated to generate a procoagulant-tissue factor activity (TFa). As LPS has been shown to consist of specific repeating oligosaccharide side chains (O-antigen) linked to a central polysaccharide core region that is, in turn, linked to the lipid region of the molecule (lipid A), we have examined the biochemical requirement of the LPS necessary for generation of TFa. Using preparations of LPS from mutant strains of bacteria, which contain varying amounts of polysaccharide in relation to lipid A, we have demonstrated that activity is associated with the lipid A region of the LPS molecule. These observations have been confirmed using isolated lipid A, which is a potent stimulator of TFa, as well as a native protoplasmic polysaccharide that is both devoid of lipid A and without detectable TFa stimulatory activity. Modification of LPS by treatment with mild alkali abrogated its capacity to stimulate TFa generation. In addition, such altered preparations of LPS partially inhibit the stimulatory effect of native LPS. Similarly, treatment of LPS (or lipid A) with the antibiotic polymyxin B substantially inhibited the stimulatory effect of LPS.

Animals↗
PubMed1987

[Cultivation and demonstration of the classic swine fever virus].

Experiments were carried out for the cultivation and indication of the swine pestivirus in several continuous and in primary cell lines, using lapinized and field strains of the virus. It was demonstrated that in the various cell cultures the strains used showed varying rates of growth. In PK-15 and pig embryonic kidney cell lines, the field strains and the virulent Vratsa strain replicated with no preliminary adaptation, forming numerous large fluorescent plaques at the 16th to 18th hour. In the same cultures the lapinized strains K and Hudson had more delayed growth, forming double plaques not until the 36th hour. In rabbit kidney primary cultures the virulent K strain only exhibited growth, and up to the 4th hour at that. All results obtained were in agreement with the results from biologic experiments with pigs and rabbits. Experiments were also carried out for the indication of the swine pestivirus in infected lamellae of the cell cultures used, which were subject to additional treatment for 5 min following primary handling with the specific marked serum with the 1:40,000 solution of Evans blue. The infected cells treated by this method showed light green fluorescence of the protoplasm, with a dark nucleus, while the intact cells had tile-red cytoplasm.

Animals↗
PubMedDate not supplied

Cerebellar astrocytomas. Part I. Macroscopic and microscopic features.

Some of the pathological features of 112 cerebellar astrocytomas seen at The Radcliffe Infirmary between 1938 and 1984 have been described. These include the following: Macroscopic appearance: Cerebellar astrocytomas, when compared to other gliomas, have an unusual tendency to become cystic. Thus, if all ages are considered only 22% are total solid tumors while the others have either a large solitary cyst or many smaller ones. Although patients with cystic tumors remain free of recurrence far longer than those with totally solid astrocytomas, the proportion of cystic and solid elements does not significantly influence the overall survival period. Moreover, the degree of tumor demarcation is not an absolute indicator of the degree of malignancy. Extent of disease: Approximately 8% of cerebellar astrocytomas infiltrate the brainstem and these cases are associated with the poorest prognosis. Supratentorial invasion is very rare and CSF dissemination is very uncommon. Only one example of the latter was recorded in the present study. It is important to note that subarachnoid spread may also occur from histologically benign tumors as well as malignant cerebellar astrocytomas. Classification by growth pattern: The classification of cerebellar astrocytomas by "growth pattern" is clearly of limited use. This is due to the presence of substantial transitional forms in both the "juvenile" and "diffuse" as well as in the "fibrillary" and "protoplasmic" classifications. Confusion also arises because of the disregard for the quantity and distribution of certain features which, in turn, limits the usefulness of the "A" and "B" type classification system. Failure to define rigorously the cell type which predominates in the "cerebral" and "diffuse" forms also creates substantial difficulties in using Ringertz' nomenclature. Further problems are caused by Zülich's "polar spongioblastomas" since cerebellar astrocytomas are not composed of primitive spongioblasts, the "polar spongioblastomas" merely representing one subtype of cerebellar astrocytoma, namely the piloid or pilocytic variety. Attempts to classify cerebellar astrocytomas in a manner which does not rely upon any specific cell type but which depends instead upon the degree of homogeneity or heterogeneity of cell growth is of limited value. Grading schemes: Although the tumors studied in the present report were not graded, previous authors have shown that "grading schemes" are of little predictive value in assessing the behavior of cerebellar astrocytomas.(ABSTRACT TRUNCATED AT 400 WORDS)

Astrocytoma↗
PubMed1988

An ultrastructural analysis of plasma membrane in the U18666A cataract.

Because the cholesterol concentration of lens fiber cell membrane in general and lens intercellular junctions in particular is comparatively high, it is likely that it plays a major role in maintaining these structures. In addition, the high concentration of cholesterol in fiber cell membrane is also likely to influence membrane fluidity. Subcutaneous injections of U18666A (3 beta-(2-diethylaminoethoxy) androst-5-en-17-one HCl) into rats effects: (1) a blockade of sterolgenesis in the lens; (2) a depletion of lens fiber cell membrane cholesterol; and (3) the development of irreversible nuclear cataracts. In the present study we have analyzed the ultrastructure of lens fiber cell membrane in adult rats, these by the freeze-etch technique. Whereas it has been previously demonstrated that intercellular junctions comprise approximately one-third of the intermediate cortical fiber cell membrane in adult rats, these junctions were completely absent between comparable fiber cells taken from opaque regions of the U18666A cataractous lenses. There was also a concomitant increase in the extracellular space between the opaque fiber cells and a substantial redistribution of intramembrane proteins in the exoplasmic and protoplasmic faces of these cells. These findings support a "hypothesis" that inhibition of endogenous lens cholesterol production leads to damage and/or degeneration of lens fiber cell membrane in general and in intercellular junctions in particular, resulting in the production of an irreversible nuclear cataract.

Androstenes↗
PubMed1988

Restriction of tumor growth in mice by sodium-deficient diet.

Generalized malnutrition results in inhibition of tumorigenesis and tumor growth in experimental animal models. Neither the specific nutrient deficiency nor the mechanism has been definitely elucidated. We have shown previously that dietary sodium deprivation in rapidly growing rats retards protoplasmic growth. This effect was correlated to the extracellular fluid (ECF) volume expansion which is dependent on sodium accumulation. Since solid tumors are composed of a large quantity of ECF (which includes plasma volume) it was postulated that preventing the accumulation of new ECF by means of sodium restriction would influence tumor growth. The present study was designed to determine the effects of salt restriction on tumor growth and to relate these effects to ECF volume. Approximately 10(6) viable B16 melanoma cells were injected into C57BL/6 x DBA/2 F1 and C57 mice. A salt restricted diet (sodium less than 3 microeq/g) was provided ad libitum. The drinking solution was distilled water for the experimental group and 0.45% saline solution for the controls. There was a significant decrease in tumor growth rates during sodium restriction. The total body ECF volume increased when dietary sodium was supplied but did not change during salt restriction. Therefore, the only source for the ECF in the tumor mass was from nontumorous tissue. We conclude that during dietary sodium restriction solid tumor growth is retarded and can proceed only to the extent that ECF is released from cachectic body tissues.

Animals↗
PubMedDate not supplied

Update of the Wiskott-Aldrich syndrome. From a new case report.

After presenting the case of a male patient who was diagnosed as suffering from the Wiskott-Aldrich syndrome at the age of 4 months, we review the main clinical (infections, bleeding and eczema), immunological (deficiency of IgM, normal IgG, elevated IgA and IgE, deficiency of total T lymphocytes, normal T4 levels, decreased levels of T8, diminished response to phytohemagglutinin and partial depletion of the lymphocyte population in biopsies of lymph nodes and spleen) and haematological (thrombocytopenia, dysmegakaryocytosis, decreased half-life and decreased granulation in the protoplasm of megakaryocytes) manifestations of this syndrome. In general, our aim is to carry out an up-to-date review of the syndrome, and to include comments on the diagnostic and therapeutic aspects.

Antibody Formation↗
PubMed1987

[Decreased G-actin content in cells at injury].

The content of G-actin was measured in aqueous extracts of rat macrophages and human lymphocytes at hyperthermia and hypoxia. The G-actin content in altered cells decreases the greater the stronger the injury. This decrease correlates well with the data on visual estimation of cell light diffusing. A possible contribution of actin polymerization and its interaction with proteins in the colloidal reactions of altered protoplasm is discussed.

Actins↗
PubMedDate not supplied

Neocerebellar hypoplasia with systemic combined olivo-ponto-dentatal degeneration in a 9-day-old baby: contribution to the problem of relations between malformation and systemic degeneration in early life.

Three different cerebral alterations, apparently formed consecutively, were observed in a 9-day-old baby. Marked cortico-neocerebellar hypoplasia was seen in a relatively well-developed paleocortex. Its teratological stage was apparently the 3rd fetal month. Almost total nerve cell loss and marked proliferation of protoplasmic and fibrous astrocytes were found in the nuclei pontis and inferior olive. Perihypoglossal and pararaphal nuclei, which are related to the cerebellum, were also affected. This degenerative process must have resulted from neuronal deprivation or inactivity, as the pertinent cortico-cerebellar area was hypoplastic, and therefore any neuronal imput was impossible (olivo-ponto-dentatal degeneration due to cortico-cerebellar hypoplasia). Massive symmetrical necrosis in the cerebral white and grey matter, basal ganglia, midbrain and bulbus, is interpreted as hypoxic damage due to perinatal convulsive attacks and cessation of respiration.

Brain↗
PubMed1978

Ultrastructural localization of anaplasmal antigens (Pawhuska isolate) with ferritin-conjugated antibody.

Antibodies from a cow with an experimentally induced infection of the Pawhuska isolate of bovine anaplasmosis were conjugated with ferritin and used to label antigenic sites in preparations of parasitized erythrocytes. Intact erythrocytes did not label on the extracellular surface. Ferritin-conjugated antibody did not pass through the intact erythrocyte to label the parasite, probably due to the large molecular size of the antibody. Damage to erythrocytic plasmalemma and inclusion body in the hemolyzed erythrocytes and complement-fixation antigen allowed labeling of anaplasmal inclusion structures. The positively labeled structures were outer surface of the pellicle, chromatin of the initial body, and inclusion appendage. Unlabeled structures included inner organismic membrane of the initial body, inclusion membrane, fibrillar protoplasmic network of the initial body, and small electron-dense bodies derived from the initial body.

Anaplasma↗
PubMedDate not supplied

Tuberous sclerosis: a neuropathological and immunohistochemical (PAP) study.

Clinical, neuropathological, and immunohistochemical (PAP) findings are reported in a 7 month-old girl with Tuberous sclerosis (TS). Polycystic kidneys and massive cardiomegaly constituted the prominent pathological features. The neuropathology of the syndrome was characterized by Megalencephaly, Subependymal giant cell astrocytoma, Very large protoplasmic astrocytes in Golgi-rapid method preparations of cortical tubers and Glial fibrillary acidic protein (GFAP)-negative giant cells in the subependymal nodules as well as in the cortical tubers. The identity of these giant cells is discussed.

Astrocytoma↗
PubMed1978

[Freud and neurology].

The author describes sequentially the neurological work of Sigmund Freud, emphasizing this little known phase of "the researcher of laboratory and microscope". It seems that Freud's writings on psychoanalysis left behind other very important scientific research, such as descriptions about protoplasmic movements of carb's neurons, giving the bases for Waldeyer's neural theory. He described cocaine's influence of the psyche, its possible use in the treatment of melancholy and as a substitute for morphine. Freud studies polyneuritis, the brain effects of scurvy and syringomyelia. His description of aphasias follow Hughlings Jackson. He became interested in the study of cerebral palsy in children and assumed that the convulsive crises were manifestations and not its etiology; he classified them, emphasizing that Friedreich's syndrome has to do with heredity and asphyxia of the newborn is acquired. In 1895 he wrote his classic: "A project for a scientific psychology for neurologists" where he writes about the cathexis concept, related to local neuronal charges and graded excitability of the CNS, upon which modern neurophysiology concentrates great attention. After this time, he went on to work on psychopatology.

Austria↗