Biomedical subjects

Zhe Cai

Publications and source records attributed to Zhe Cai.

4 recordsLinked to original sources

PubMed2004

[Covert infection of severe acute respiratory syndrome in health-care professionals and its relation to the workload and the type of work].

OBJECTIVE: To study severe acute respiratory syndrome (SARS) covert infection in health-care professionals and its relation to work intensity and type of work. METHODS: Specific antibodies to SARS virus in 1 127 serum specimens from health-care professionals who had a close contact history with patients of SARS and 92 healthy persons were assayed with ELISA. RESULTS: The health-care professionals consisted of 287 men and 840 women, aged 21 - 55 years (mean 34 +/- 9 years). The overall positive rate of specific IgG and IgM was 2.57% (29/1 127); the positive rates in nurses, doctors and laboratory workers, and supervisors were 3.46%, 1.41%, 2.86%, respectively. 34.5% of the infected worked in the ICU, and 65.5% in the general wards. None of them presented clinical SARS. Medical examination was also carried out for 313 people who had close contact with the 29 antibody positive health care professionals, but no clinical SARS was found. CONCLUSIONS: Covert infection can be found in the health-care professionals and it showed no contagiousness. The positive rate of specific antibodies was higher in ICU where the work intensity was higher. The positive rate in nurses was higher than in doctors.

Adult↗

PubMed2004

[The study of producing allogenic-tissue engineering cartilage].

OBJECTIVE: To explore the feasibility of producing neocartilage tissue by using allogenic chondrocytes as seeding cells, artificial absorbable scaffold-polylactic acid (PLA) as matrices. METHOD: The cartilage tissue was obtained from the four limbs of neoborn New Zealand rabbits (born 3-5 days), digested by II collagenase, proliferated in vitro, then seeded the chondrocytes on PLA scaffolds. The chondrocyte-PLA complex were cultured 7-10 days in vitro, then implanted in dorsal subcutaneous of adult New Zealand rabbits. Specimens harvested 3 weeks, 5 weeks and 7 weeks after implantation respectively and subjected to histologic analysis. RESULT: Chondrocyte-PLA complex implanted in adult new Zealand rabbits for 7 weeks, produced neo-cartilage as proved by histologic analysis, along with time extending, chondrocyte matrice secretion increased, invading inflammatory cell decreased. CONCLUSION: Using allogenic chondrocytes as seeding cells and PLA scaffold, it is successful to generate allogenic tissue-engineering cartilage in animals that have inherent immunity.

Animals↗

PubMed2002

High-throughput mass-directed parallel purification incorporating a multiplexed single quadrupole mass spectrometer.

We report on the development of a parallel HPLC/MS purification system incorporating an indexed (i.e., multiplexed) ion source. In the method described, each of the flow streams from a parallel array of HPLC columns is directed toward the multiplexed (MUX) ion source and sampled in a time-dependent, parallel manner. A visual basic application has been developed and monitors in real-time the extracted ion current from each sprayer channel. Mass-directed fraction collection is initiated into a parallel array of fraction collectors specific for each of the spray channels. In the first embodiment of this technique, we report on a four-column semipreparative parallel LC/MS system incorporating MUX detection. In this parallel LC/MS application (in which sample loads between 1 and 10 mg on-column are typically made), no cross talk was observed. Ion signals from each of the channels were found reproducible over 192 injections, with interchannel signal variations between 11 and 17%. The visual basic fraction collection application permits preset individual start collection and end collection thresholds for each channel, thereby compensating for the slight variation in signal between sprayers. By incorporating postfraction collector UV detection, we have been able to optimize the valve-triggering delay time with precut transfer tubing between the mass spectrometer and fraction collectors and achieve recoveries greater than 80%. Examples of the MUX-guided, mass-directed fraction purification of both standards and real library reaction mixtures are presented within.

Chromatography, High Pressure Liquid↗

PubMed2002

[Experimental study on microvascular architecture of human and rabbit flaps with two methods].

OBJECTIVE: To study effective method of showing the microvascular architecture of human and rabbit skin flaps. METHODS: According to endogenous alkaline phosphatase activity, Gomori-Takamatsu method and NBT/BCIP method were used to observe the microvascular architecture. RESULTS: Both methods had capability to demonstrate the microvascular architecture of the human skin flap, whereas the examining results of rabbits were negative. CONCLUSIONS: Great difference of endogeneous alkaline phosphatase activity exists in different animals. Gomori-Takamatsu method and NBT/BCIP method are useful in study of microvascular architecture of human skin flaps.

Alkaline Phosphatase↗