Zheng Congyi

Microcalorimetric study of the metabolism of U-937 cells undergoing apoptosis induced by the combined treatment of hyperthermia and chemotherapy

Hyperthermia is a useful adjunct in cancer therapy, as it can increase the effectiveness and decrease the toxicity of currently available cancer treatments such as chemotherapy and radiation. In this study we determined the power-time curves of U-937 cell line treated by the combination of hyperthermia and Carmofur by using an LKB 2277 Bioactivity Monitor. The maximal thermal power and the heat production were used to evaluate the antitumor effect. Our results show that the combined treatment of hyperthermia and Carmofur had a synergistic antitumor effect, which is consistent with the apoptosis ratio obtained by TUNEL assay. The results also indicate that the metabolic activity of apoptotic cells is lower than that of normal cells. Thus microcalorimetry is a powerful tool in fields of hyperthermia.

Experimental studies on ultralow frequency pulsed gradient magnetic field inducing apoptosis of cancer cell and inhibiting growth of cancer cell.

The morphology characteristics of cell apoptosis of the malignant tumour cells in magnetic field-treated mouse was observed for the first time. The apoptotic cancer cell contracted, became rounder and divorced from adjacent cells; the heterochromatin condensed and coagulated together along the inner side of the nuclear membrane; the endoplasmic reticulums (ER) expanded and fused with the cellular membrane; many apoptotic bodies which were packed by the cellular membrane appeared and were devoured by some lymphocytes and plasma. Apoptosis of cancer cells was detected by terminal deoxynucleotidyl transferase mediatedin situ nick end labeling (TUNEL). It was found that the number of apoptosis cancer cells of the sample treated by the magnetic field is more than that of the control sample. The growth of malignant tumour in mice was inhibited and the ability of immune cell to dissolve cancer cells was improved by ultralow frequency (ULF) pulsed gradient magnetic field; the nuclei DNA contents decreased, indicating that magnetic field can block DNA replication and inhibit mitosis of cancer cells. It was suggested that magnetic field could inhibit the metabolism of cancer cell, lower its malignancy, and restrain its rapid and heteromorphic growth. Since ULF pulsed gradient magnetic field can induce apoptosis of cancer cells and inhibit the growth of malignant tumour, it could be used as a new method to treat cancer.

Genomic Sequence Determination of Classical Swine Fever Virus Persistent Infection Strain

Full genomic sequence of a newly isolated persistent infection strain of classical swine fever virus was firstly determined. It was demonstrated by sequence analyses that nucleotides homologies of this strain compared with virulent Shimen and vaccine HCLV were 89.7% and 87.7%, and homologies of amino acids were 94.8% and 93.3%, respectively. The sequencing results primarily suggest a tighter relationship between this persistent infection strain and virulent Shimen strain than vaccine HCLV strain.

A Personalized Microbe Biodiversity Dataspace Information System

It can not provide dynamic view mechanism in previous dataspace information system. In this paper, the dynamic extendable view mechanism provided by object deputy model is proposed for personalized dataspace information system which can provide rich semantics and enough flexibility. The flexible inheritance avoids a lot of data redundancy. The cross class query mechanism allows users to find more related data based on complex relationships. The personalized dataspace service provides less storage space consumption and shorter query response time. The experiment result shows that our approach is more feasible and efficient than the traditional one.

The difference of energy metabolism between persistent and cytocidal virus infections

Abstract In this study, microcalorimetric measurements were carried out on PK-15 cell line persistently infected by cholera swine fever virus (CSFV) and BHK-21 cell line infected by foot and mouth disease virus (FMDV). The aim of this investigation was to investigate the difference of energy metabolism between the different kinds of virus infections—persistent infection and cytocidal infection. The thermogenesis curves determined by using a LKB 2277 Bioactivity Monitor were significantly different. From these thermogenic curves, the maximum heat production rate P m and total heat output Q are obtained. The results show that energy metabolism is different between persistent infection and cytocidal infection.

Action of selenium compounds on the cellular metabolism by microcalorimetry

A new method is introduced to study the action between biomaterials and organism. By using an LKB-2277 bioactivity monitor and ampoule method, the fundamental thermogenesis curves of the metabolic process of pk-15 and the toxic effect of three kinds of selenomorpholine compounds on it were studied at 37°C. From the thermogenesis curves, the heat released by pk-15 metabolism was calculated. The results show that the selenium compounds all have toxic action on the metabolism process of pk-15 at the range of experimental concentrations. The sequence of the toxic action of selenium compounds is: Na2SeO3>β-(N-selenomorpholine)-ethyl phenylketone hydrochloride>selenomorpholine.

Study on the purification of OPV produced on vero cells with Q-Sepharose F. F.

Q-Sepharose Fast Flow (Q-Sepharose F. F.) was adopted to purify the suspensions of type I, II, III oral poliovaccine (OPV), which is prepared from Vero cells. After clarification and concentration by ultrafiltration, the recovery of virus infected titre may attain above 85%. Using column chromatography on Q-Sepharose F. F. to purify the concentrated virus suspensions, the purified viruses attain 100% recovery of virus infectivity. Dot membrane hybrization was used to detect DNA with the probe of Vero cell genome DNA which was labeled with α-P32 dATP, the contents of residual substrate DNA was less than 100 Pg/dose. The process of downstream had no significant influence on some biological characters of purified viruses, such as virus morphology, tumorigenicity, rct/40 character and capsid protein. This downstream reseach indicates that Q-Sepharose F. F. is an ideal chromatography material for purifying OPV prepared from Vero cells.

Cryopreservation of pollen by vitrification inBrassica

The key factors affecting pollen cryopreservation by vitrification inBrassica campestris var.purpurea were investigated. The factors involved the pollen maturity, the pollen resistance to dehydration, the components of vitrification solution (PVS), and the concentration of diluent. Thus, a suitable procedure was established for pollen vitrification, the maximum relative survival rates of mature (at the day of anthesis) and nearly mature (3 days before anthesis) pollen were about 80%, 63% respectively. This procedure has been also successfully applied to two other species (Brassica napus, Brassica chinensis). The advantage of cryopreservation of pollen by vitrification was discussed.