Dextran sedimentation for study of neutrophil polarization / 南方医科大学学报

<p><b>OBJECTIVE</b>To determine the optimal method for separating neutrophils for studying neutrophil polarization.</p><p><b>METHODS</b>Human neutrophil was separated from healthy human peripheral blood by Percoll density gradient centrifugation and Dextran sedimentation. The cell polarization, purity and activity of the neutrophils were determined, and F-actin polymerization and [Ca2+]i were analyzed.</p><p><b>RESULTS</b>No significant difference was found in cell polarization, purity and activity of the human neutrophils separated by Dextran sedimentation and Percoll density gradient centrifugation (P>0.05), but F-actin polymerization was inhibited in PMNs separated by Dextran sedimentation, and the peak value of [Ca2+]i was decreased by 25% in PMNs separated by Dextran sedimentation compared to the cells separated by Percoll density gradient centrifugation.</p><p><b>CONCLUSIONS</b>Both Percoll density gradient centrifugation and Dextran sedimentation can be used for isolating human neutrophils to study cell polarization, but the former method allows better isolation. Dextran sedimentation can be considered when a large number of neutrophils need to be separated.</p>

Establishment and assessment of Caco-2 cell in vitro absorption model / 南方医科大学学报

<p><b>OBJECTIVE</b>To establish and assess the Caco-2 cell in vitro absorption model.</p><p><b>METHODS</b>Caco-2 cells were cultured on the millipore filters fixed in Snapwell transport chamber. The cell morphology, transepithelial electrical resistance, mannitol efflux rate and alkaline phosphatase activities were monitored during culture.</p><p><b>RESULTS</b>After 21 days of in vitro culture, formation of tight junction was observed between the cells. The transepithelial electrical resistance reach a relatively stable value of 620-/+47 Omega.cm(2), the mannitol efflux rate was lower than 0.3%.h(-1).cm(-2), and the alkaline phosphatase activity in the apical side was significantly higher than that in the basolateral side.</p><p><b>CONCLUSION</b>The established Caco-2 cell model shows similar morphology to intestinal epithelial cells with formation of polarity, and can be used as an in vitro model for absorption studies.</p>

A field trial for evaluating the safety of recombinant human interferon alpha-2b for nasal spray / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To evaluate the safety of recombinant human interferon alpha-2b for nasal spray for the prevention of SARS and other upper respiratory viral infections.</p><p><b>METHODS</b>Field epidemiologic evaluation was conducted, the design was randomized and had a synchronously parallel control group. In the study, the drugs were given for five days and all subjects were followed up for ten days.</p><p><b>RESULTS</b>During the period of using interferon, body temperature of the experimental group was normal compared to the control group. Experimental group had more influenza-like symptoms than the control group (P < 0.05), such as headache (4.83%-7.09%), dizziness (7.17%-11.63%), lassitude (8.55%-15.06%), muscular soreness (4.43%-7.09%), pharynx dryness (12.10%-17.85%), angina (6.25%-8.72%), abdominal pain (2.30%-5.50%) and diarrhea (2.45%-5.66%). Most of side effects reached their peak with in the first 3 days. Except for pharynx dryness, the incidences of all other side effects declined after completion of the use of the trial drug, and incidences of some symptoms in experimental group were lower than those of the control group. There were no significant differences in the symptoms of cough and expectoration between the experimental group and the control group. The incidence of exanthem in the control group was significantly higher than that in the experimental group. The side effect of bloody nasal mucus was not observed in experimental group, which had been reported by other authors in several volunteer studies.</p><p><b>CONCLUSION</b>Using recombinant human interferon alpha-2b for nasal spray could lead to some influenza-like symptoms, however, all those symptoms were mild , reversible, and relieved after completion of the use of the trial drug. No serious side effects were found during the period of following up. The authors conclude that the drug is safe.</p>

A field trial of recombinant human interferon alpha-2b for nasal spray to prevent SARS and other respiratory viral infections / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To study the preventive effect of recombinant human interferon alpha-2b for nasal spray against SARS and other common respiratory viral infections by serum-epidemiological method.</p><p><b>METHODS</b>A randomized, placebo-controlled, double-blind field trial study in populations with 14,391 persons from SARS prevalent cities or provinces in China during May-Jun, 2003 and Dec-Apr, 2004. Interferon alpha-2b was given twice per day, once 9 x 10(5) IU by nasal spray for 5 days. Serum samples were taken at 15 days after last administration. Serological tests included SARS IgG antibody and IgM antibodies against influenza B, parainfluenza virus types 1-3, adenovirus type 3, 7 and respiratory syncytial virus by using commercial ELISA kits.</p><p><b>RESULTS</b>No statistically significant difference in serum SARS IgG antibody positive rate was found between the interferon and control groups among 2,757 serum samples. On the other hand, after using interferon, all four respiratory viruses (parainfluenza virus types 1-3 influenza B, adenovirus types 3, 7 and respiratory syncytial virus) in interferon group had lower IgM antibody positive rates than those in control group. Among them there were statistically significant differences between the interferon and control groups for parainfluenza virus, influenza B and adenovirus. The preventive efficacy of interferon against four respiratory viruses was different, from high to low, the rank was Flu B (66.76%), parainfluenza types 1-3 (66.75%), RSV (39.61%) and adenovirus (32.86%). The average preventive efficacy was 50.27%.</p><p><b>CONCLUSION</b>The recombinant human interferon alpha-2b for nasal spray could decrease the rates of common respiratory viruses infection in the selected population.</p>

Study on serum p53 protein in cops in Guangzhou city / 中华流行病学杂志

<p><b>OBJECTIVE</b>Serum p53 protein overexpression was detected in population exposed to traffic exhaust gas to study the relation between traffic exhaust gas and the increased risk in p53 gene mutation.</p><p><b>METHODS</b>Serum p53 protein expression was measured by enzyme-linked immunosorbent assay. Relationship between different types of job and serum p53 protein overexpression were studied by pearson Chi-square tests.</p><p><b>RESULTS</b>Results on serum p53 protein overexpression on jobs outside of office (5.74%) were not significantly higher than jobs inside the office. However, it suggested that traffic police men (12.12%) working outside of office, with whose length of service longer than 30 years had a significant overexpression of serum p53 protein than the others (5.36%) whose length of service was less than 30 years (P < 0.05, OR = 2.43, 95% CI: 1.11 - 5.33). Overexpression rate of p53 protein appeared to be 6.89% in the group whose average weekly exposure hours were more than 40 hours, which was significant higher than the group whose exposed hours were less than 40 hours (P < 0.05, OR = 1.71, 95% CI: 1.03 - 2.81).</p><p><b>CONCLUSION</b>The result suggested that traffic exhaust gas was likely to cause mutation of p53 gene and increasing the incidence of lung cancer.</p>