Granular Accumulations Research Articles

Transformation of calcite (CaCO3) into earlandite [Ca3(C6H5O7)2·4H2O] by the fungus Trichoderma asperellum BDH65

Biotransformation of amorphous calcium carbonate into calcite and other inorganic calcium minerals is a worldwide phenomenon in the bacterial kingdom. In this study, it showed that calcite (CaCO3) could be transformed into an organic mineral earlandite [Ca3(C6H5O7)2·4H2O], through the dissolution of calcite and subsequent crystallization by the fungus Trichoderma asperellum BDH65. Observations by light microscopy showed that the fungal induced crystal particles were deposited as irregularly granular accumulations of micro globular particles. Scanning and transmission electron microscopy revealed that each micro globular particle consists of numerous needle-like crystals with domed end assembling radially with their ends pointing outside from its centers. This is clearly different from the shapes of microsheets formed by the chemical method. The mineral phase of the fungal catalyzed crystals is identified as earlandite, which is chemically identical to calcium citrate tetrahydrate. Structure and properties of the fungal formed crystals are further characterized by Fourier transform infrared spectroscopy and thermogravimetry, showing a similar pattern with those observed for chemically synthesized calcium citrate tetrahydrate. The current result may useful for understanding bioweathering of minerals and rocks, and insight into the calcium cycling driven by fungi.

A study on the motion and accumulation process of non-cohesive particles

In order to further understand the mechanism of landslide-debris flow and predict the entire movement process and accumulation range of landslide hazards, the movement process of non-cohesive particles and the distribution of accumulation at the bottom of the slope were studied. Firstly, physical laboratory-scale tests on the sliding accumulation process of non-cohesive granular accumulations under self-weight were carried out, and the effects of different volumes and gradations on the sliding accumulation were analyzed. Then, the discrete element software PFC3D was used to perform three-dimensional numerical back analysis of the tests to refine the key parameters required for the numerical simulation, and to understand better the movement and accumulation state of the granular body. The results showed that the spherical particles exhibit obvious lateral expansion during the acceleration stage, and the front-end particles had a clear "shuttle" distribution, which became even more obvious with the increase in the content of large particles. The reverse-order phenomenon of spherical particles after sliding was that the proportion of small particles in the proximal end was far higher than their original proportion in the accumulation body. With the increase in the volume of the accumulation body, the phenomenon became more obvious, and stopping of large particles above the small particles was observed. The research results can provide reference for further studies of the movement process and the distribution patterns of the slip instability failures of non-cohesive accumulation bodies.

Plants work out which way is up

Plant Science Gravity-sensing cells in plants contain tiny grains of starch called statoliths. The orientation of the statoliths changes with the plant's orientation. The gravity-sensing cells respond to even the slightest tilt off of the established plane. Plant statoliths seem to evade the rules of physics that govern other granular materials. In live-cell imaging of young wheat shoots, Berut et al. observed that statolith piles behave more like slowly creeping liquids than like granular accumulations. The reason is that the individual statoliths are always jiggling around, perhaps because of interactions with the plant cytoskeleton. Proc. Natl. Acad. Sci. U.S.A. 10.1073/pnas.1801895115 (2018).

Atypical and Classical Forms of the Disease-Associated State of the Prion Protein Exhibit Distinct Neuronal Tropism, Deposition Patterns, and Lesion Profiles

A number of disease-associated PrP forms characterized by abnormally short proteinase K-resistant fragments (atypical PrPres) were recently described in prion diseases. The relationship between atypical PrPres and PrP(Sc), and their role in etiology of prion diseases, remains unknown. We examined the relationship between PrP(Sc) and atypical PrPres, a form characterized by short C-terminal proteinase K-resistant fragments, in a prion strain of synthetic origin. We found that the two forms exhibit distinct neuronal tropism, deposition patterns, and degree of pathological lesions. Immunostaining of brain regions demonstrated a partial overlap in anatomic involvement of the two forms and revealed the sites of their selective deposition. The experiments on amplification in vitro suggested that distinct neuronal tropism is attributed to differences in replication requirements, such as preferences for different cellular cofactors and PrP(C) glycoforms. Remarkably, deposition of atypical PrPres alone was not associated with notable pathological lesions, suggesting that it was not neurotoxic, but yet transmissible. Unlike PrP(Sc), atypical PrPres did not show significant perineuronal, vascular, or perivascular immunoreactivity. However, both forms showed substantial synaptic immunoreactivity. Considering that atypical PrPres is not associated with substantial lesions, this result suggests that not all synaptic disease-related PrP states are neurotoxic. The current work provides important new insight into our understanding of the structure-pathogenicity relationships of transmissible PrP states.

Properties of L-Type Bovine Spongiform Encephalopathy in Intraspecies Passages

The origin and transmission routes of atypical bovine spongiform encephalopathy (BSE) remain unclear. To assess whether the biological and biochemical characteristics of atypical L-type BSE detected in Japanese cattle (BSE/JP24) are conserved during serial passages within a single host, 3 calves were inoculated intracerebrally with a brain homogenate prepared from first-passaged BSE/JP24-affected cattle. Detailed immunohistochemical and neuropathologic analysis of the brains of second-passaged animals, which had developed the disease and survived for an average of 16 months after inoculation, revealed distribution of spongiform changes and disease-associated prion protein (PrP(Sc)) throughout the brain. Although immunolabeled PrP(Sc) obtained from brain tissue was characterized by the presence of PrP plaques and diffuse synaptic granular accumulations, no stellate-type deposits were detected. Western blot analysis suggested no obvious differences in PrP(Sc) molecular mass or glycoform pattern in the brains of first- and second-passaged cattle. These findings suggest failures to identify differences in mean incubation period and biochemical and neuropathologic properties of the BSE/JP24 prion between the first and second passages in cattle.

Enterospora canceri n. gen., n. sp., intranuclear within the hepatopancreatocytes of the European edible crab Cancer pagurus

Only 1 genus (Nucleospora) within 1 family (Enterocytozoonidae) of the Microsporidia contains species that are parasitic within the nuclei of their host cells; to date, all described intranuclear Nucleospora spp. parasitise fish. This study describes the first intranuclear microsporidian parasite of an invertebrate, the European edible crab Cancer pagurus L. (Decapoda: Cancridae). Infected crabs displayed no obvious external signs, and maximum apparent prevalence of infection within a monthly sample was 3.45%. Infected hepatopancreatic tubules were characterised by varying numbers of hypertrophic and eosinophilic nuclei within epithelial cells. Parasite stages appeared as eosinophilic granular accumulations causing margination of host chromatin. In advanced cases, the tubule epithelia degenerated, with parasites and sloughed epithelial cells appearing in tubule lumens. All life stages of the parasite were observed within host nuclei. Uninucleate meronts were not detected, although binucleate stages were observed. Multinucleate plasmodia (sporogonal plasmodia) contained up to 22 nuclei in section, and late-stage plasmodia contained multiple copies of apparatus resembling the polar filament and anchoring disk, apparently associated with individual plasmodial nuclei. As such, aggregation and early assembly of sporoblast components took place within the intact sporogonial plasmodium, a feature unique to the Enterocytozoonidae. Liberation of sporoblasts from plasmodia or the presence of liberated sporoblasts was not observed in this study. However, large numbers of maturing and mature spores (measuring 1.3 +/- 0.02 x 0.7 +/- 0.01 microm) were frequently observed in direct contact with the host nucleoplasm. Considering the shared features of this parasite with microsporidians of the family Enterocytozoonidae, and the unique presence of this parasite within the nucleoplasm of decapod crustacean hepatopancreatocytes, this parasite (Enterospora canceri) is proposed as the type species of a new genus (Enterospora) of microsporidian. Molecular taxonomic work is now required, comparing Enterospora to Enterocytozoon and Nucleospora, the 2 other genera within the Enterocytozoonidae.

The effect of in ovo ethanol exposure on retina and optic nerve in a chick embryo model system

Ocular anomalies seen in children with fetal alcohol syndrome (FAS) suggest that ocular structures are sensitive to alcohol exposure during their development. This study was designed to investigate the effect of in ovo ethanol (EtOH) exposure on retinal development and myelinization of optic nerve fibers at an ultra structural level in a chick embryo model system. Prior to incubation, fertilized chicken eggs were injected once with 100 μl of either 0.9% NaCl (vehicle control), or EtOH solutions at different doses (10, 30, or 50%, v:v in 0.9% NaCl) into their air sacs and incubated at 37.5 °C and saturation humidity. On day 20 embryos were analyzed in terms of their viability and growth and the optic cups including the optic nerves were dissected out. Specimens were processed for electron microscopy (EM). Results showed that, EtOH significantly decreased the viability of chick embryos ( P < 0.045), and caused significant prenatal growth retardation ( P < 0.004) in a dose-dependant manner. Light microscopy of semi thin sections revealed that prenatal exposure to EtOH resulted in both retinal degeneration and optic nerve hypoplasia ( P < 0.001) in a dose-dependant manner. EM revealed that a dose-dependant decrease in the number of myelinated nerve fibers was profound in groups exposed to EtOH ( P < 0.001). Furthermore, the myelin coats observed were thinner than those seen in control embryos. In groups exposed to EtOH myelin sheets were unorganized and contained vacuolar structures in between them. The tissue in between the cells and optic nerve fibers, on the other hand, lost its intact appearance with vacuolar and vesicular structures in between them. In addition, the optic nerve fibers contained granular accumulations in EtOH exposed groups. A dose dependent degeneration was also observed in retinas of EtOH exposed groups. The effect of EtOH was profound in pigment epithelium (PE), inner plexiform layer (IPL), and ganglion cell layer (GC). Mitochondrial deficiencies, and alterations in melanin granule number and distribution dominated the defects seen in PE. On the other hand, EM findings of all the affected layers were suggestive of induced cell death in EtOH exposed groups. Thus, this study suggests retinal development with the emphasis on melanin pigmentation in PE and optic nerve myelinization as potential targets of prenatal EtOH exposure and discusses potential mechanisms of EtOH action on these tissues.

Widespread spinal cord involvement in corticobasal degeneration

We examined spinal cord lesions in eight patients with a pathological diagnosis of corticobasal degeneration (CBD). Using Gallyas-Braak (G-B) staining or AT-8 tau immunostaining, a few neuropil threads were identified in the white matter of the CBD spinal cords, mainly in the anterior funiculus, whereas the posterior funiculus was well preserved without threads. In the gray matter of the CBD spinal cords, particularly in the intermediate gray matter, there were widespread neuropil threads and neuronal inclusions. Large motor neurons in the anterior horn, neurons in the intermediolateral column, and Clarke's column were relatively well preserved from neuronal loss and gliosis. Neuronal inclusions were of the globose type, suggestive of neurofibrillary tangles (NFTs), or showed diffuse granular accumulations of cytoplasmic tau, suggestive of pretangles. No typical NFTs, recognized by Bodian silver staining, were identified. The distribution of neuropil threads and G-B- or AT-8 tau-positive small neurons resembled that of interneurons. No astrocytic plaques were present in any of the CBD spinal cords, and only a few coiled bodies were seen. Neuropil threads in the white and gray matter and neuronal inclusions in the gray matter were prominent in cervical segments, and their density decreased caudally. We suggest that the presence of neuropil threads, particularly in the cervical intermediate gray matter, and the presence of neuronal inclusions, particularly in cervical interneurons, is an essential pathological feature of CBD.

Pituitary tumorigenesis in prolactin gene-disrupted mice.

Targeted disruption [knockout (KO)] of the mouse prolactin (PRL) gene created an animal model of primary isolated PRL deficiency in which there is no detectable PRL bioactivity. Pituitary glands of young adult female PRLKO mice were hyperplastic, and many cells had expanded cytoplasms with granular accumulations of an N-terminal peptide encoded by the disrupted PRL gene (KO/10 peptide). Confocal imaging showed that the pituitaries in PRL(+/+) and PRL(+/-) females contained dense accumulations of apparently Golgi-associated immunoreactive PRL. PRLKO female mice (15-18 months old) developed hyperemic pituitary adenomas. The pituitary tumors in PRLKO mice synthesized the KO/10 peptide, which implies that the tumors arise from the lactotroph lineage. Anchorage-independent growth was observed among pituitary cells from PRLKO mice, aged 8 months or older, but not in cells from 3-month-old PRLKO mice. GH cells appeared to be normal in PRLKO pituitaries, but were displaced by the hyperplastic and hypertrophic growth of KO/10-positive cells. Bromocriptine suppressed mean pituitary weight in 8-month-old PRLKO mice compared with vehicle-treated PRLKO animals (20 +/- 0.01 and 60 +/- 10 mg; P < 0.01). We infer that pituitary lactotrophs of PRLKO mice suffer from a dual pathology that includes hypertrophy resulting from endoplasmic reticulum expansion and hyperplasia, with adenomatous transformation, in part as a consequence of disrupted dopaminergic feedback regulation.

Electron Microscopic Detection of Copper in the Liver of Two Patients with Morbus Wilson by EELS and EDX

A 20-year-old male patient with morbus Wilson was liver transplanted because of terminal failure of liver function. The explanted liver showed a strong macronodular cirrhosis as typically seen in Wilson disease. There were visible granular accumulations in the hepatocytes after the rubeanic acid or rhodanine method for histochemical detection of copper. The electron microscopic studies on ultrathin sections revealed numerous electron-dense lysosomes and residual bodies. The elemental analysis in transmission electron microscope (TEM) with electron energy loss spectroscopy (EELS) and in scanning electron microscope (SEM) with energy dispersive x-ray analysis (EDX) showed copper-specific signals of electron-dense accumulations inside these dark lysosomes and residual bodies. In a second case, Wilson disease was diagnosed after autopsy of a 31-year-old patient by liver electron microscopy and EELS; strong electron-dense lysosomes and residual bodies with positive copper signals were found inside hepatocytes. For negative control, hepatocytes with iron accumulation after idiopathic hemochromatosis and liver cirrhosis were also analyzed by EELS in TEM, which showed strong iron, but only a few or no copper signals. Atomic absorption spectroscopy (AAS) in 16 liver samples of healthy and cirrhotic liver revealed only in both cases of Wilson disease a strong increased copper concentration higher than 100 µg Cu/g. The electron microscopic detection of copper-containing hepatocytic lysosomes is helpful for the diagnosis of early stages of Wilson disease in addition to the quantification of hepatic copper by AAS.

Expression of platelet-derived growth factor-beta receptors on human fibroblasts. Regulation by recombinant platelet-derived growth factor-BB, IL-1, and tumor necrosis factor-alpha.

Stimulation of human fibroblasts by platelet-derived growth factor (PDGF)-BB leads to a down-regulation of PDGF beta-receptors and a concomitant appearance of intracellular granular accumulations of receptors, as determined by stainings with the mAb PDGFR-B2. The granules contained both the ligand and PDGF beta-receptors, as revealed by double-immunofluorescence staining, and were formed in response to PDGF-BB but not in response to other cytokines tested. The formation of intracellular PDGF beta-receptor granules was dependent on PDGF-BB concentration and time of stimulation. The granular PDGF beta-receptor staining on cells treated with PDGF-BB for 1 h at 37 degrees C was used to investigate the effects of macrophage-derived cytokines on PDGF beta-receptor expression. The number of PDGF beta-receptor granules was found to be reduced in fibroblasts grown for 48 h in the presence of PDGF-BB, TNF-alpha, or IL-1; PDGF-AA under the same conditions had no effect. The reduction observed was paralleled by a decrease in cell surface expression of PDGF beta-receptors, measured as binding of 125I-PDGF-BB and of the PDGFR-B2 antibody. Furthermore, both TNF-alpha and IL-1 decreased the detergent-extractable pool of PDGF-beta receptors in the fibroblasts, as revealed by immunoblotting of detergent cell extracts. Finally, the decrease in PDGF beta-receptors after culturing of the cells in the presence of TNF-alpha and IL-1 was accompanied by a decreased incorporation of [3H]thymidine in response to PDGF-BB stimulation. In conclusion, our data suggest that certain macrophage-derived cytokines can modulate the expression of PDGF beta-receptors by cultured fibroblasts, which may contribute in part to their reduced responsiveness to PDGF.

Histochemical features of ragged-red fibres in diseased skeletal muscles

In the present communication, the activity of 24 oxidoreductases, transferases, isomerases and hydrolases was examined histochemically in ragged-red fibres of human skeletal muscle specimens. The biopsy material was obtained from patients with neuromuscular diseases caused by an abnormally metabolic functioning of the muscle mitochondria. The granular accumulations of the ragged-red fibres were characterized by an impressive activity of all mitochondrial and most non-mitochondrial enzymes examined, whether participating in the aerobic or in the anaerobic pathways. With the exception of mitochondrial Mg2(+)-stimulated ATPase, acid phosphatase and AMP-aminohydrolase, there was no activity of the other hydrolytic enzymes studied in these regions. The strong activity of mitochondrial ATPase points to the presence of loosely coupled and/or uncoupled mitochondria. Ragged-red fibres that exhibited a diffuse and corpuscular activity of acid phosphatase, were always undergoing necrotic changes. Adsorption studies with diluted enzyme solutions demonstrated that the granular accumulations display a specific, moderate affinity for glycolytic enzymes.

A new model of epidermal differentiation: Induction by mechanical stimulation

In vivo, epidermal cells are committed to terminal differentiation in which they undergo a series of morphological and biochemical changes. In vitro, keratinocytes are able to undergo some steps of this differentiation process only. In view of the fact that in vivo skin is continuously subjected to mechanical stress, we investigated the stimulation of differentiation of transformed keratinocytes by mechanical stimulation. The cells, grown in plastic culture dishes, were periodically treated with weights exerting a pressure of 0.015 Ncm-2. This stimulation lasted from 1 to 4 days. Then keratinocytes were examined using indirect immunofluorescence, 3H-thymidine and 14C-amino acid incorporation, SDS polyacrylamide gel electrophoresis, and Western blotting. Following pressure treatment, the previously monolayered keratinocytes locally grew up to several layers, the number of horny scales increased and, after 4 days, the pattern of cytokeratin was modified. The total amount of keratin increased, forming granular accumulations, while the proliferation rate of the cells decreased. Both the 67 kDa and 49.5 kDa keratin subunits increased in stimulated cells. Moreover, a weak keratin band of 44 kDa appeared that was not present in controls. The results demonstrate that cyclic pressure promotes differentiation of cultivated epidermal cells.

Development of the tegument of Echinococcus granulosus (Cestoda) protoscoleces during cystic differentiation in vivo.

During the first 4 days following infection, early tegumentary changes are confined to the protoscolex soma of Echinococcus granulosus, the thick glycocalyx being lost and the blunt elevations, flattened. The Golgi complexes within the tegumentary cytons produce T2 vesicles that increase in number in the tegument from days 4 to 12, whereas T1 vesicles decline. Spineless, truncated microtriches develop at the somal surface, and the laminated layer starts to form around the developing cyst from days 20-40 onwards. T2 vesicles do not appear to be involved in its formation and decline in number. Two additional vesicle types participate in the production of the laminated layer: T4 vesicles contribute to the carbohydrate matrix, and 'G' vesicles form granular accumulations. Cystic differentiation is completed after 2-3 months, when the spined microtriches and rostellar hooks of the scolex are shed into the laminated layer and replaced by truncated microtriches. These ultrastructural changes are discussed with respect to parasite survival.

Histochemical investigations on the localization of the purple acid phosphatase in the bovine spleen.

The localization of the purple tartrate-resistant, iron-containing acid phosphatase in the bovine spleen was studied by enzyme histochemistry at the light and electron microscopic levels as well as by immunohistochemistry. The purple phosphatase was localized only in lysosome-like-organelles of cells belonging to the reticulo-phagocytic system. The same cells were identified as containing large iron(III)-deposits as ferritin in homogeneously granular accumulations and freely in the cytoplasm, or as hemosiderin in siderosomes. The phagocytosing cells containing purple phosphatase and ferritin often had close contact with clusters of aged and deformed erythrocytes. A possible catabolic role of the purple enzyme as a phosphatase degrading phosphoproteins of the erythrocyte membrane and the cytoskeleton was assumed.

Physiological and ultrastructural changes in the chloroplasts of snap bean plants under LPS lamps during chlorosis and regreening

Abstract Iron chlorosis‐like symptoms developed in the terminal leaves of susceptible bean (Phaseolus vulgaris L. ‘Astro') plants when grown in growth chambers containing low pressure sodium (LPS) lamps that are deficient in UV and blue wavelengths. Plants grown under broad‐band radiation, provided by cool white fluorescent lamps, did not develop chlorosis. Ultrastructural and metabolic investigations examined the progress of chlorosis in leaves of plants exposed to nutrient end radiation stress under LPS lamps. Addition of full‐strength Hoagland's #1 nutrient solution or Peter's* 20–20–20 fertilizer to plants grown under LPS lamps resulted in the degradation of maturing chloroplasts in the terminal leaves. After the starch reserves were depleted, the internal membrane system degenerated. Well‐formed grana, characteristic of normal chloroplasts, were degraded, giving rise to spherical membrane structures. Chlorophyll and protein were lost and granular accumulations formed in the chloroplasts. This paper d...

Traumatic presacral hemorrhage: angiographic diagnosis and therapy.

Presacral hemorrhage commonly accompanies fractures of the posterior pelvic ring. The source of this bleeding is the fractured cancellous bone and supporting ligamentous structures of the sacrum and sacroiliac joint. The radiologic appearance is of granular and punctate contrast accumulations due to extravasation from the iliolumbar and lateral sacral branches of the hypogastric artery. This bleeding can be controlled by small particle embolotherapy provided care is taken not to bypass the posterior division of the hypogastric artery.

Cytoskeletal function of cortical microtubules in the ciliateColpoda

The cytoskeletal function of cortical microtubular structures is explored by high-pressure treatment of the ciliated protozoonColpoda cucullus. This ciliate has two regions of form asymmetry which are apparently maintained by microtubules, namely the somatic groove and the right oral lip. Pressure induced changes in cellular morphology and motility were found to be a function of the magnitude of pressure and duration of compression. Cells exposed to 5,000 psi for 25 minutes, 7,500 psi for 12 minutes, and 10,000 psi for 3 minutes are quiescent and acquire a rounded shape. Observation by electron microscopy of cells exposed to 5,000 psi for 25 minutes indicates that the disappearance of the somatic groove and eversion of the oral apparatus are coincident with the disassembly of the microtubular rootlets in the groove and the supraepiplasmic microtubules in the right oral lip. Other changes accompanying the pressure-induced disassemblies include the reduction in numbers of overlapping microtubular ribbons in the cortical ridges and the appearance of cortical granular accumulations. The essential role in form-maintenance played by microtubular components is discussed.

Cutaneous immunofluorescence in dermatomyositis.

Seven patients with dermatomyositis who displayed severe skin and muscle disease, and in whom coexistent systemic lupus erythematosus (LE) was excluded, were evaluated by direct immunofluorescent biopsies of skin lesions. Specimens from six showed deposits of immunoglobulins and complement in small to moderate amounts at the dermal-epidermal junction zone. These deposits were usually in the form of focal granular accumulations which lacked continuity and were not well developed as are those seen in LE, or fluorescent subepidermal hyaline bodies. One patient, however, had a more well developed band of immunoglobulins at the dermal-epidermal junction. All normal skin specimens in these patients were negative by immunofluorescence. These findings were helpful in clarifying differences in cutaneous immunofluorescence between dermatomyositis and LE, indicating that dermatomyositis specimens can usually be differentiated from those of LE patients, but demonstrating the possibility that confusion might rarely occur in interpreting a lesional immunofluorescent biopsy in dermatomyositis.

Renal biopsies in long-term survivors of renal transplantation: immunofluorescent studies.

Renal biopsies of 4 patients surviving from 1 to 3 1/2 years following renal transplantation were studied with immunofluorescent techniques. Three of the 4 patients have normal renal function; the fourth patient (longest survivor in this series) has had a gradual decrease in creatinine clearance but has maintained normal blood urea nitrogen and serum creatinine levels. The patients are maintained on azathioprine and prednisone. Histologic sections were stained with specific rabbit antisera to human IgC, IgM, and C'3, and with a fluoresceinated goat anti-rabbit γ-globulin. Routine histologic preparations revealed mononuclear cell infiltration and endarteritis with endothelial proliferation of varying severity in each patient. Fluorescent anti-globulin studies demonstrated plasma cells in the interstitium and small flecks of globulin in perivascular areas and within the piled-up endothelium. Granular accumulations of gamma globulin were seen along glomerular capillary loops of the longest survivor. Small accumulations of complement were detected in similar perivascular and endothelial locations. It is suggested that antigen-antibody-complement complexes in the vessel walls may serve as an irritative stimulus to endothelial proliferation.