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Biomedical subjects

Z Zhai

Publications and source records attributed to Z Zhai.

32 records · Page 2Linked to original sources
PubMed1997

[Morphogenesis of AcMNPV nucleocapsid].

In this paper we reported that the nucleocapsid morphogenetic process of AcMNPV in which polyhedrin gene was deleted in the nuclei of sf9 cells. First, the capsid proteins entered the nuclei and assembled many 34nm diameter long fascicularly arranged hollow-tube structures. Then viral DNA entered these tubes that turned into solid structure with high electronic density. The solid structure separated at a certain distance to form 34 x 26 nm fascicular bacilliform structure known as nucleocapsid. Finally, fascicular nucleocapsids were wrapped by envelope and became complete multicapsid morphotype viron.

Animals↗
PubMed1996

Effect of 764-3 on aggregation and calcium movements in aequorin-loaded human platelets.

Washed human platelets were loaded with the Ca(2+)-sensitive photoprotein, aequorin, using hypoosmotic shock treatment-technique. Then aggregation and cytoplasmic ionized calcium concentration ([Ca2+]i) changes in response to collagen or thrombin were measured simultaneously in the aequorin-loaded human platelets with a Platelet Ionized Calcium Aggregometer. 764-3, an active component isolated from the Chinese medicinal herb Salvia Miltiorrhiza Bge, inhibited platelet [Ca2+]i rise as well as aggregation evoked by collagen or thrombin in the presence of extracellular Ca2+. After the extracellular Ca2+ was removed by addition of EGTA, collagen or thrombin, causing no aggregation, still elicited platelet [Ca2+]i rise which reflected Ca2+ mobilization from intraplatelet stores. Under this condition, 764-3 could also suppress platelet [Ca2+]i rise. Analysis shows that 764-3 inhibits platelet Ca2+ influx and Ca2+ mobilization with similar potency, which accounts for its suppression of platelet [Ca2+]i rise, and must contribute to its inhibition of platelet aggregation.

Biological Transport, Active↗
PubMed1995

[The distribution of SbV nonstructural protein 2 (nsP2) in host cell].

The distribution of SbV nsP2 has been observed by means of immunolabelling electron microscopy. The results showed that SbV nsP2 existed both in the cytoplasm and in the nucleus of host cell. When the cDNA of SbV nsP2 was transfected in host cell, the nsP2 also accumulates in the nucleus.

Cell Nucleus↗
PubMed1995

Biological activity assays of cell-free reassembled nuclei--injecting cell-free reassembled nuclei into unfertilized eggs can induce the eggs to cleave and reconstitute asters, and the injected nuclei undergo cell cycle changes.

Nucleus may reassemble spontaneously in cell-free mixture of HeLa metaphase chromosomes, Xenopus egg extracts and ATP-regenerating system, and the nucleus shows some biological activities. It is found that, after being injected into unfertilized mature eggs, the cell-free reassembled nuclei can cause the eggs to cleave and reconstitute asters in their cytoplasm, and the injected nuclei undergo changes in response to cell cycle regulators stored in the eggs, and that reinjecting cytostatic factors (CSF) into the eggs can stabilize the eggs in mitotic phase, cause the nuclei disassembly and chromatin condensation to chromosomes.

Animals↗
PubMed1993

[The multiplication of Sindbis virus in BHK-21 cell].

One step growth curve of Sindbis virus (SbV) in BHK-21 cells showed that a lot of progeny viruses could be observed at 2 hr. after infection. The titer of virus reached the highest about 10(9)TCID50/ml at 6hr. post infection. The viral morphological characters and morphogenetic process in BHK-21 cells were examined by electron microscopic techniques. The dynamics of viral proteins synthesis and the effect on host cell were studied and discussed in this paper.

Animals↗
PubMed1992

Localization of adenovirus DNA by in situ hybridization electron microscopy.

Biotinylated deoxyadenosine triphosphate (dATP) (Bio-7-dATP) and 3H deoxythymidine triphosphate (dTTP) labeled adenovirus DNA were hybridized in situ to thin sections of Lowicryl K4M-embedded and whole-mount extracted HeLa cells infected with adenovirus. The biotinylated probe was detected by exposing the extracted cells or sections to antibodies against biotin followed by colloidal gold-conjugated secondary antibodies and then critical-point dried while 3H-dTTP labeled probe by electron microscopic autoradiography. On Lowicryl K4M sections, gold particles and silver grains were mainly restricted in the nucleus. Furthermore, whole-mount results suggested that replicating adenovirus DNA is localized on the nuclear matrix of its host cell. In this paper, the described non-radioactive procedures for hybrid detection offered several advantages: a) rapid signal detection; b) superior morphological preservation and spatial resolution; c) precise localization; and d) on Lowicryl K4M sections, signal to noise equivalent to radiolabeling.

Acrylic Resins↗
PubMed1990

[The relationship of Sindbis virus assembly and the viral protein 6K with intermediate filaments].

The relationship of Sindbis virus (Sbv) assembly with intermediate filaments was studied by means of whole-mount and DGD embedment-free technique of EM together with the procedure of gentle extraction. In the early stage of Sbv infection, the "virus assembly center" was suspended in the intermediate filament network. In the late stage, the assembling and assembled virus nucleocapsids were associated with intermediate filaments. It is presumable that the virus nucleocapsids may move from the "virus assembly center" to cytoplasmic membrane along the intermediate filaments. Further study using immunolabelling technique indicated that the nonstructural protein 6K of Sbv was probably associated with intermediate filaments as well.

Cell Line↗
PubMed1982

Cytoplasmic origin of an intranuclear DNA virus (duck plague virus).

Electron microscopic and autoradiographic studies have revealed that the assembly and maturation of duck plague virus (DPV, an intranuclear DNA virus) occur both in the nucleus and in the cytoplasm. A dense cytoplasmic matrix (tentatively called viroplast) is the basic organelle in which the assembly of nucleocapsids occurs. At the early stage of virion maturation, dense particles, approximately 40 nm in size, appear and become assembled nucleocapsid structures later on. As capsids become mature, they obtain a diameter of 95-105 nm. The viroplast matrix gradually decreases in size, and a loose structure appears inside as the nucleocapsids increase in number. When viroplast has almost disappeared, nucleocapsids become abundant, regularly arranged around the cytoplasmic vacuoles. They bud into these vacuoles, thereby acquiring their envelopes. These nucleocapsids differ from those found in the nucleus both in morphology and in distribution. Electron microscopic autoradiography has shown that there is a huge amount of DNA in viroplast. DNA for the assembly of the nucleocapsids in the cytoplasm is derived from the very viroplast.

Animals↗