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Biomedical subjects

Z B Wu

Publications and source records attributed to Z B Wu.

At least 19 recordsLinked to original sources
PubMed2001

Studies on the energy release of rice mitochondria under different conditions by means of microcalorimetry.

The thermodynamic and kinetic behaviors of energy release of mitochondria isolated from rice (Oryza sative L.) were studied by using a LKB 2277 Bioactivity Monitor under different conditions. The thermogenesis curves of energy release of the rice mitochondria (which had been kept at 0-3 degrees C for 15 h and 40 day before the determination) were determined respectively at 25 and 30 degrees C, and the difference in shape of the thermogenesis curves and thermodynamic and kinetic characteristics were compared. The thermodynamic and kinetic parameters of energy release of the mitochondria in the thermogenesis increasing stage have been calculated, and the experimental thermokinetic equations of the thermogenesis have been established. The results indicated that the lower the temperature, the slower the energy release of the rice mitochondria. Both the thermogenesis and the energy release rate of the rice mitochondria increased after the mitochondria was kept at lower temperature for 40 days. One can use the methods to characterize the ability of the rice mitochondria to release energy under different conditions.

Calorimetry↗
PubMed2000

Metric representation of DNA sequences.

A metric representation of DNA sequences is borrowed from symbolic dynamics. In view of this method, the pattern seen in the chaos game representation of DNA sequences is explained as the suppression of certain nucleotide strings in the DNA sequences. Frequencies of short nucleotide strings and suppression of the shortest ones in the DNA sequences can be determined by using the metric representation.

Globins↗
PubMed1999

[Enzymehistochemical and immunohistological changes of skeletal muscle motor end-plates and muscle fibers and their relation to the time of death].

In order to investigate the relationship between the retrograde changes of the skeletal muscle and the time of death in various postmortem intervals (PMI), a systemic study of the enzymehistochemical activity of AChE, SDH, LDH, Ca(2+)-ATPase and the immunohistochemical reaction of SYN in motor end-plates and muscle fibers was conducted in rats under different temperatures and at various PMI. The results were analyzed and compared by an image processing system. It was found that these changes were related to the PMI, especially AChE changes. The AChE could be used as a sign-enzyme of skeletal muscle to date death.

Acetylcholinesterase↗
PubMed1994

Study on the role of mast cells in the development of liver fibrosis during diethylnitrosamine (DEN) -induced hepatocarcinogenesis in rats.

The mast cells (MC) and their roles in the development of liver fibrosis during experimental hepatocarcinogenesis in rats have been studied immunohistochemically and electron microscopically. Pronounced MC hyperplasia occurred after beginning of the treatment of DEN. The vast majority of mast cells in fibrotic livers was present in thickened fibrous septa. Intracellular or pericytial collagen type IV and laminin staining were found in mast cells, collagen types I, III and fibronectin were negative. Mast cells mainly distributed in proximity to basement membrane and the electron microscopical observation revealed a close topographic relationship between mast cells and fibroblasts. The fibroblasts phagocytized the granules released by mast cells and thus were activated, showing enhanced formation of collagenous fibrils. The mast cells may be derived from blood circulation or replicated in situ. Those findings indicated that mast cells take part in the process of fibrosis at least by two ways: (1) It directly synthesizes the basement membrane components; (2) It stimulates the fibroblasts or other types of cells which have the potential functions in fibrogenesis by releasing granule mediators or cytokines acting upon the fibrosis process.

Animals↗
PubMed1994

[The expression of PCNA and EGF gamma in tumor cells of experimental hepatocellular carcinoma of liver and squamous cell carcinoma of stomach in rats].

The expression of PCNA and EGF gamma in chemically induced hepatocellular carcinoma and squamous cell carcinoma cells from rats were observed with immunohistochemical techniques. The results showed that the carcinoma cells of both tumors revealed a positive immunoreaction to both factors. According to the amount of MC surrounding the tumor cell nests, the specimens could be divided into two groups: the group with abundant MC infiltration and the group with little or no MC infiltration. The PCNA positive cells in carcinoma cell nests of both groups were calculated respectively. It revealed that the amount of PCNA positive cells in the group with little or no MC was significantly more than that in the other group. The ratio between the 2 groups in liver carcinoma was approximately 3:1 and in stomach cancer it was 2:1. An overexpression of EGF gamma was observed in tumor tissues of both groups, but the amount of EGF gamma positive cells in the group with little or no MC was much higher than that of the group with abundant MC.

Animals↗
PubMed1993

[Study on the relationship between most cells and tumor growth speed during hepatocarcinogenesis in the rats].

The nucleolar organizer regions (NORs) of normal rat hepatocytes and hepatocytes in the precancerous hyperplastic nodules as well as the cells of hepatocellular carcinoma induced by Nitrosomorpholine in rats were observed with aid of AgNOR-staining and electron microscopy. The observation revealed that the number of Ag-granules in the NORs of carcinoma cells was significantly more than that in the hyperplastic and normal hepatocytes. The ultrastructural observation of the nucleoli of interphase nuclei showed just the same result as the AgNOR-staining. The alcian blue-PAS-ABC combined staining revealed a very marked infiltration of mast cells (MC) within the carcinoma tissue and in its surroundings in 4 animals, while other 5 animals showed only a slight or no MC infiltration in the surroundings of carcinoma tissue. The observation of the phenotype of MC revealed that only one of the animals with carcinoma showed a relatively marked infiltration of both mucosa mast cells (MMC) and connective tissue mast cells (CTMC), while all other rats showed mainly an infiltration of CTMC. The Ag-granules in the NORs of carcinoma cells of the carcinomas with more MC infiltration were less than that of carcinomas with only slight or without MC infiltration. The difference was statistically significant. The significance of above mentioned results was discussed and a relationship between MC and prognosis of liver carcinoma was suggested.

Animals↗
PubMed1992

[Role of mast cells in the development of liver fibrosis during experimental hepatocarcinogenesis in rats].

The role of mast cells (MC) in the development of liver fibrosis during experimental hepatocarcinogenesis in rats has been studied light microscopically, histochemically and electron microscopically. An increase in the number of MC in the proliferated connective tissue was found. The histochemical examination showed that the increased MC almost exclusively were connective tissue mast cells (CTMC), whilst mucosa mast cells (MMC) were only rarely seen. The electron microscopical observation revealed a close topographical relationship between MC and fibroblasts sending out pseudopodia, which encircled granula released from MC and phagocytized them. The fibroblasts with phagocytized MC granules were markedly activated showing enhanced formation of collagenous fibrils. Finally, the role of MC in the development of liver fibrosis is discussed.

Animals↗
PubMed1991

A consecutive ultrastructural study of action of homoharringtonine on fibroblasts in vitro.

The authors studied the effect of homoharringtonine (Hh), a semisynthetic Chinese herb, on the ultrastructure of in vitro cultured human conjunctival fibroblasts (HFb) and its mechanism of action. Preliminary results showed that the main characteristics of HFb damage caused by Hh were invagination of the nuclear membrane, aggregation and margination of chromatin, and massive vacuolization of the cytoplasm. In addition, Hh can inhibit the secretion of collagen fibers and the synthesis of microfilaments. Therefore, Hh might be an effective agent in the prevention and treatment of proliferative eye disorders.

Actin Cytoskeleton↗
PubMed1990

A highly efficient method for staining ultrathin sections.

A simple and efficient staining method to handle simultaneously thirty (or even more) electron microscope grids with ultrathin sections is described. The device applied is easily constructed from inexpensive and readily available materials but can bring easily high quality staining results, and the amount of stain and washing water required is very small.

Microscopy, Electron↗
PubMed1990

[Morphometric studies on the growth of bile canaliculi during liver regeneration in rats].

Morphometric analysis of the liver during regeneration after partial hepatectomy showed that the mean area and number of bile canaliculi increased, while the volume density of microvilli related to the lumina of the canaliculi decreased. These changes were observed 12 hours after the operation, which gradually returned to normal on the third day after operation. It indicated that the decrease of volume density of microvilli was the result of enlargement of bile canaliculi, which was different from the decrease of microvilli due to passive widening of the canaliculi such as in cholestasis from loss of microvilli. All these phenomena suggest that enlargement of the area of bile canaliculi during liver regeneration may be due to the increase of membranous protein synthesis. Moreover, the increase of the number of bile canaliculi suggests that the proliferation of hepatocytes is associated with formation of new branches of bile canaliculi.

Animals↗
PubMed1990

[The effect and mechanism of estrogen on hepatocyte regeneration in rats].

Liver regeneration model following partial hepatectomy was used to study the effect and mechanism of estrogen on hepatocyte regeneration of rats. Each animal in the experimental groups received a single injection of diethylstilbestrol (DES) subcutaneously. Results showed that estrogen had a remarkable promoting effect on hepatocyte regeneration. Both 3H-TdR labelling and mitosis indices of hepatocytes in the experimental groups increased markedly. In DES-treated rats, synthesis of estrogen receptor of hepatocyte increased gradually and the translocation of ER from cytoplasm to nucleus was also enhanced at the same time, indicating that the mechanism of DES on hepatocyte regeneration consisted promoting of the interaction of ER and nucleus. There was no statistically significant difference (P greater than 0.05) found in the number of Kupffer cells between all the experimental and their corresponding control groups. But in ultrastructure, Kupffer cells of animals in the experimental groups presented increase of cell size with abundant cytoplasm; longer and more pseudopodia as well as phagolysosomes, suggesting that DES could activate Kupffer cell and promote its function. The relationship between Kupffer cells and liver regeneration is discussed.

Animals↗
PubMed1989

Light and electron microscopic detection of lectin binding sites in normal and disordered human gastric tissues.

Lectins are now widely used as histochemical markers and probes for carbohydrate structures in glycoproteins. In the present study, a method is described for the light and electron microscopic detection of Ulex europaeus agglutinin I binding sites in the normal and neoplastic tissues. The results showed that the gastric mucus-producing cells and some vascular endothelial cells could be strongly stained with labelled lectin in normal mucous membrane. The positive staining reactivity was reduced greatly in neoplastic tissue either in paraffin sections or in thin sections. This suggested that the secretions of gastric carcinoma are different from those of normal gastric mucosa and represent differentiation of neoplastic cells to some degree.

Adenocarcinoma↗
PubMed1989

Immunohistochemical localization of vascular endothelial cell factor VIII/von Willebrand factor antigen in human normal and disordered gastric tissues.

Vascular endothelial cell factor VIII/von Willebrand factor antigen (FVIII/vWF Ag) of normal and disordered gastric tissues was studied with staphylococcus protein A-gold (PAG) labelling followed by photochemical silver reaction. FVIII/vWF Ag was localized clearly in the tissue fixed with various common fixatives and embedded in paraffin without enzyme treatment. The most satisfactory staining and the least nonspecific background were observed in the tissues fixed with Zamboni's and Bouin's solutions. The staining reaction could be enhanced, if the sections were pretreated with trypsin and subtilisin. Under the electron microscope, the gold particles were found over the Weibel-Palade bodies of vascular endothelial cells in the tissues fixed either in Zamboni's solution or in Zamboni's solution-osmium tetroxide, and embedded either with Lowicryl K4M or with Epon 812. It has been proved to be a better technique in investigation of FVIII/vWF Ag in vascular endothelial cells.

Adenocarcinoma↗