203 research outputs found
Miocene Diatom Biostratigraphy of Onshore Sequences on the Pacific Side of Northeast Japan, with Reference to DSDP Hole 438A (Part 2)
The biostratigraphic distribution of Miocene diatoms in onshore sequences on the Pacific side of Northeast Japan has been investigated with reference to Hole 438A of the Deep Sea Drilling Project. Determination of stratigraphic ranges of diagnostic diatom species enables the establishment of datum levels that are most reliable for a long-distance correlation. Eleven diatom datums are proposed on the basis of the stratigraphic distribution pattern of several species belonging to the genus Denticulopsis. By employing these datums, a composite sequence of Miocene strata is divided biostratigraphically into eleven zones in upward sequence, as follows : The Actinocyclus ingens Zone, Denticulopsis lauta Interval-zone, D. hyalina Interval-zone, D. hustedtii Interval-zone. D. nicobarica Interval-zone. D. praedimorpha Range-zone, Coscinodiscus yabei Interval-zone, D. dimorpha Range-zone, D. katayamae Interval-zone, Thalassionema schraderi Interval-zone, and D. kamtschatica Zone. Onshore sequences have precisely been correlated with DSDP Hole 438A by means of these datum levels and zones proposed herein. Detailed correlation of the proposed zones with those of previous authors leads to a systematic explanation of the diatom biostratigraphy in the northwestern Pacific
Miocene Diatom Biostratigraphy of Onshore Sequences on the Pacific Side of Northeast Japan, with Reference to DSDP Hole 438A (Part 1)
Taxonomic investigations of the genus Denticulopsis are attempted through observations aided by both optical and scanning electron microscopes. Species belonging to the genus Denticulopsis are classified into six groups on the basis of structure of the valve face and the presence or absence of secondary pseudosepta. A new taxonomic formulation is proposed in order to describe a diatom frustule and its components by taking representative Denticulopsis species. A comparative study of morphology of D. praedimorpha and D. dimorpha indicates that a structural difference of the connecting band provides the most easily recognizable character to differentiate these two species. Three trends in the morphological development of this genus are discussed. A new diatom species Denticulopsis katayamae is described and this species has been found to be useful for biostratigraphic studies of Miocene sequences of Northeast Japan
Immunoliposomes bearing polyethyleneglycol-coupled Fab′ fragment show prolonged circulation time and high extravasation into targeted solid tumors in vivo
AbstractWe have developed a new type of long-circulating immunoliposome (Fab′–PEG immunoliposomes) which is efficiently extravasated into the targeted solid tumor in vivo. Small unilamellar liposomes (100–130 nm in diameter) were prepared from distearoylphosphatidylcholine (DSPC), cholesterol (CHOL) and a dipalmitoylphosphatidylethanolamine derivative of PEG with a terminal maleimidyl group (DPPE-PEG-Mal), and conjugated Fab′ fragment of antibody. Inclusion of DPPE-PEG-Mal and linkage of the Fab′ fragment instead of intact antibody to PEG terminals allowed the liposomes to evade RES uptake and remain in the circulation for a long time, resulting in enhanced accumulation of the liposomes in the solid tumor. Because of the ability of such Fab′–PEG immunoliposomes to target solid tumors, they appear highly attractive as carriers of not only chemotherapeutic agents, but also of macromolecular drugs
MALIGNANT ONCOCYTOMA OF THE PARANASAL SINUS
A case of malignant oncocytoma developing in the paranasal sinus of a 37-year-old Japanese man with a habit of heavy smoking is described. The primary tumor was found in the right maxillary sinus with local invasion to the nose and right ethmoidal sinus ; it was composed of nests of large oncocytic cells, with finely granular and eosinophilic cytoplasm, nuclear pleomorphism
and prominent nucleoli, surrounded by proliferation of spindle-shaped cells in some areas. Electron microscopically, the cytoplasm of oncocytic tumor cells was characterized by abundant mitochondria, and immunohistochemical investigation revealed positive binding for antibodies to S-100 protein and α₁-antitrypsin, but a negative reaction for both cytokeratin and vimentin. At autopsy, metastatic nodules of tumor in the lungs, liver and pancreas independently exhibited both oncocytic cell- and sarcomatous cell compartments. This phenomenon is rare, and to the authors' knowledge, this would be histologically an ususual report of malignant oncocytoma with sarcomatous metastatic nodules arising from the paranasal sinus to be described in the literature
Complete replication of hepatitis C virus in cell culture.
Many aspects of the hepatitis C virus (HCV) life cycle have not been reproduced in cell culture, which has slowed research progress on this important human pathogen. Here, we describe a full-length HCV genome that replicates and produces virus particles that are infectious in cell culture (HCVcc). Replication of HCVcc was robust, producing nearly 10(5) infectious units per milliliter within 48 hours. Virus particles were filterable and neutralized with a monoclonal antibody against the viral glycoprotein E2. Viral entry was dependent on cellular expression of a putative HCV receptor, CD81. HCVcc replication was inhibited by interferon-alpha and by several HCV-specific antiviral compounds, suggesting that this in vitro system will aid in the search for improved antivirals
Detection of Antibodies against the Four Subtypes of Ebola Virus in Sera from Any Species Using a Novel Antibody-Phage Indicator Assay
AbstractThe natural host for Ebola virus, presumed to be an animal, has not yet been identified despite an extensive search following several major outbreaks in Africa. A straightforward approach used to determine animal contact with Ebola virus is by assessing the presence of specific antibodies in serum. This approach however has been made very difficult by the absence of specific reagents required for the detection of antibodies from the majority of wild animal species. In this study, we isolated a human monoclonal antibody Fab fragment, KZ51, that reacts with an immunodominant epitope on Ebola virus nucleoprotein (NP) that is conserved on all four Ebola virus subtypes. The antibody KZ51 represents a major specificity as sera from all convalescent patients tested (10/10) and sera from guinea pigs infected with each of the four Ebola virus subtypes competed strongly with KZ51 for binding to radiation-inactivated Ebola virus. These features allowed us to develop a novel assay for the detection of seroconversion irrespective of Ebola virus subtype or animal species. In this assay, the binding of KZ51 Fab-phage particles is used as an indicator assay and the presence of specific antibodies against Ebola virus in sera is indicated by binding competition. A prominent feature of the assay is that the Fab-phage particles may be prestained with a dye so that detection of binding can be directly determined by visual inspection. The assay is designed to be both simple and economical to enable its use in the field
Co-morbidity of progressive supranuclear palsy and amyotrophic lateral sclerosis : a clinical-pathological case report
Background: The coexistence of distinct neurodegenerative diseases in single cases has recently attracted greater attention. The phenotypic co-occurrence of progressive supranuclear palsy (PSP) and amyotrophic lateral sclerosis (ALS) has been documented in several cases. That said, the clinicopathological comorbidity of these two diseases has not been demonstrated.
Case presentation: A 77-year-old man presented with gait disturbance for 2 years, consistent with PSP with progressive gait freezing. At 79 years old, he developed muscle weakness compatible with ALS. The disease duration was 5 years after the onset of PSP and 5months after the onset of ALS. Neuropathological findings demonstrated the coexistence of PSP and ALS. Immunohistochemical examination confirmed 4-repeat tauopathy, including globose-type neurofibrillary tangles, tufted astrocytes, and oligodendroglial coiled bodies as well as TAR DNA-binding protein 43 kDa pathology in association with upper and lower motor neuron degeneration. Immunoblotting showed hyperphosphorylated full-length 4-repeat tau bands (64 and 68 kDa) and C-terminal fragments (33 kDa), supporting the diagnosis of PSP and excluding other parkinsonian disorders, such as corticobasal degeneration. Genetic studies showed no abnormalities in genes currently known to be related to ALS or PSP.
Conclusions: Our case demonstrates the clinicopathological comorbidity of PSP and ALS in a sporadic patient. The possibility of multiple proteinopathies should be considered when distinct symptoms develop during the disease course
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