BACKGROUND:Preliminary data showed that the application of human platelet lysate to human umbilical cord mesenchymal stem cell culture can better maintain the characteristics of stem cells than the application of serum-free medium. However, the serum-free medium can better improve the proliferation of mesenchymal stem cells in vitro than the human platelet lysate.OBJECTIVE:To screen out a better mesenchymal stem cell cultivation system that can greatly maintain the characteristics and proliferation rate of human umbilical cord mesenchymal stem cells.METHODS:Six human umbilical cord specimens were inoculated in six culture systems, and the primary culture of umbilical cord mesenchymal stem cell was performed. These six culture systems were respectively MesenCult serum-free medium with 2% human platelet lysate (group A), StemPro serum-free medium with 2% human platelet lysate (group B), MesenCult serum-free medium (group C), StemPro serum-free medium (group D), low glucose-DMEM with 10% fetal bovine serum (group E), low glucose-DMEM with 10% human platelet lysate (group F). The cells were subcultured at 14 days after inoculation to compare the effects of different culture systems on the morphology, surface markers, differentiation and proliferation of human umbilical cord mesenchymal stem cells.RESULTS AND CONCLUSION:(1) The morphology of passage 3 cells in group D was elongated and uneven in size. The morphology of passage 3 cells was flattened in groups E and F, but the cells in the other groups were spindle-shaped and uniform. There were no significant changes in morphology and size between passage 3 and 5 cells in A and B. In group C, the morphology of passage 5 cells was more flattened and uneven in size compared with passage 3 cells. In group D, the morphology of passage 5 cells was more elongated than that of passage 3 cell. In group E, the morphology of passage 5 cells was more flattened than that of passage 3 cells. There was no significant difference in morphology between passage 3 and 5 cells in group F. (2) The expression rate of cell surface markers had no significant difference at different passages in each group. (3) The adipoinduction and osteoinduction rates were relatively higher in groups A and B compared with groups E and F, and lowest in groups C and D. (4) The cell proliferation rate for each passages in group A was significantly higher than that in group C. The cell proliferation rate for each passage in group B was significantly higher than that in group D. The cell proliferation rate for each passage in groups E and F was significantly lower than that in groups A and B. To conclude, these results suggest that the combination of serum-free medium with human platelet lysate could better maintain the characteristics and the proliferation efficiency of mesenchymal stem cells.

Objective To evaluate the extent and anatomic distribution of air trapping in lung in young asymptomatic female subjects to achieve early diagnosis of small airway diseases.Methods Fifty young females with normal pulmonary function were included retrospectively in this study.All subjects underwent both inspiratory and expiratory CT scans,the percentage of the area of air trapping(AT)and the percentage of the area of emphysema(Emph)were quantitatively analyzed.Comparison between bilateral lungs was analyzed using independent-samples t test;Comparisons among lobes were done using one-way ANOVA or Kruskal-Wallis rank sum test;Pairwise comparisons between lobes were conducted using LSD test or paired comparison;The effects of each lobe on AT were analyzed using Spearman's rank correlation coefficient,simple linear regression and multiple stepwise regression.Results There was a certain degree of air trapping in lung and a small amount of emphysema in young asymptomatic females.Air trapping was mainly located in the right middle lobe (RML)and bilateral upper lobes.The ratio of air trapping to volume was the highest in RML and the change of air trapping in the bilateral upper lobes had the greatest influence on the air trapping degree of the whole lung.Conclusion There is a certain degree of air trapping in lung in young asymptomatic females.The occurrence and development of air trapping in RML may be a sensitive biomarker for the early detection of pathophysiological changes in small airway diseases using imaging procedures.

BACKGROUNDMagnetic resonance imaging (MRI) has advantages in showing pathologic changes of disc space infection, which is important in clinical treatment. The purpose of this study was to describe the MRI findings of disc space infections in relation to chronicity.

METHODSMRI of 60 patients from January 1, 2002 to April 30, 2012 in Ottawa Hospital were retrospectively evaluated by two radiologists blindly. All patients had histological confirmation, with 55 having microbiological confirmation as well. These patients were divided into acute (n = 18), subacute (n = 21) and chronic (n = 21) based on histological findings. The following potential signs of MRI finding were assessed: marrow edema, endplate erosions, disk fluid and height change, paraspinal mass, epidural collection, facet fluid and enhancement in the marrow, disc, paraspinal mass, and epidural involvement. Statistical analysis consisted of t- or F-tests and chi-square test.

RESULTSIn the 60 patients, 83 infected discs (single disc in 45 patients, 2-4 discs in 15 patients) were found, including 22 discs in the acute group, 30 discs in the subacute group, and 31 discs in the chronic group. There was a significant difference in the extent of marrow edema between the acute, subacute and chronic groups (P < 0.05), with a gradually increasing extent from acute to chronic. The extent of endplate erosions increased with chronicity, but was not statistically significant. There were significant differences in the disc fluid, epidural collection, and disc enhancement among the acute, subacute and chronic groups, as well as the facet fluid between acute and chronic groups (P < 0.05). There were no significant differences in the present probability of disc height loss, paraspinal mass, and marrow enhancement among the three groups (P > 0.05).

CONCLUSIONSFrom acute to chronic infections, the extent of marrow edema and endplate erosions appeared to gradually increase. Epidural collections and facet fluid are most frequently found in the acute group, while disc fluid and disc enhancement are more common in the chronic patients.

Adult ; Aged ; Aged, 80 and over ; Discitis ; diagnosis ; Female ; Humans ; Magnetic Resonance Imaging ; methods ; Male ; Middle Aged ; Retrospective Studies