ABSTRACT
BACKGROUND: Dermal fibroblasts are widely used and demanded, and there are various isolation methods, but no comparative studies on enzyme digestion methods are reported. OBJECTIVE: To compare the cell count, morphology, migration and proliferation of human dermal fibroblasts isolated by two enzyme digestion methods. METHODS: Human dermal fibroblasts were isolated using either dispase-collagenase or trypsin, and their cell yield and viability were assessed by morphology, cell count and proliferation curve by cell counting-kit 8 assay. The ability of migration was observed by cell scratch test. RESULTS AND CONCLUSION: The fibroblasts digested with dispase-collagenase were fused at 6-7 days after inoculation, and the cells isolated by trypsin digestion were fused at 8-9 days after inoculation. Fibroblasts could be obtained by both two digestion methods. The production in the dispase-collagenase group was significantly higher than that in the trypsin group. The migration rate in the dispase-collagenase group was significantly faster than that in the trypsin group. The growth cures of the human dermal fibroblasts in the two groups revealed that the cell count was positively correlated with time, and the absorbance values of the dermal fibroblasts in the dispase-collagenase group were significantly higher than those in the trypsin group at 3, 4 and 5 days after incubation. To conclude, the cell yields, migration and proliferation of dermal fibroblasts digested with dispase-collagenase are significantly higher than those of the cells digested by trypsin, indicating that dispase-collagenase digestion results in better isolation and viability of dermal fibroblasts from the dermis.
ABSTRACT
<p><b>OBJECTIVE</b>Poor growth is a common problem in premature neonates. No sufficient attention has been paid to the nutrition deficit and extrauterine growth retardation in premature neonates in China. The present study aimed to assess the incidences of intrauterine growth retardation (IUGR) and extrauterine growth retardation (EUGR) in premature neonates in Shanghai area and their correlated factors.</p><p><b>METHODS</b>Data of the neonates discharged between January 1, 2003 and December 31, 2004 from 5 hospitals (Xinhua Hospital, Shanghai Children's Medical Center, Shanghai Children's Hospital, Pediatric Hospital Affiliated to Fudan University, and Shanghai International Peace Maternity and Child Health Hospital) were reviewed. The criteria of exclusion were cases who died or had a malformed appearance, the mother had endocrine or metabolic diseases. The criteria for enrollment were (1) gestational age < 37 weeks, (2) admitted less than 24 hours after birth and discharged from the same hospital, (3) duration of hospitalization was > or = 7 days. The growth values on discharge of each patient were compared to the expected values based on the intrauterine growth data and postmenstrual day on discharge. Growth retardation was defined as measured growth values (weight, head circumference) < or = 10th percentile of the values (growth expectation based on estimated postmenstrual age). In each specific group, the number of neonates with < or = 10(th) percentile for each growth parameter was counted and the percentages of patients who had values < or = 10(th) percentile on birth and discharge were calculated. The growth curves used for assessing birth weight and head circumference for different gestational age neonates were those published in 1986. All the data were analyzed using the SPSS statistical software package. The risk factors for extrauterine growth retardation on weight and head circumference were estimated with logistic regression model.</p><p><b>RESULTS</b>The subjects included 1196 premature neonates in the five hospitals (734 boys and 462 girls). The incidence of IUGR was 22.7% and 19.2% assessed by weight and head circumference, respectively. The incidence of EUGR was 49.7% and 23.1% assessed by weight and head circumference, respectively. Assessment of IUGR in accordance with the birth weight and head circumference in the five hospitals showed no significant correlation between IUGR and non-IUGR by birth weight (chi(2) = 4.944) and head circumference (chi(2) = 0.017) respectively. Whereas the assessment of EUGR in accordance with weight and head circumference showed a significant correlation between EUGR and non-EUGR by weight on discharge (chi(2) = 28.109), but no significant correlation was found between EUGR and non-EUGR by head circumference on discharge (chi(2) = 0.275). In specific birth weight groups, the lower the weight, the higher the incidence of IUGR and EUGR by the weight and head circumference. The incidence of EUGR in VLBWI was 78.9% and 50.0% assessed by weight and head circumference, respectively. Assessed by weight, significant correlation was observed between EUGR and non-EUGR in birth weight (t = 18.674), hospitalization duration (Z = -8.790) and the median number of day for total using EN (Z = -4.650); but by the head circumference, significant correlation was observed in head circumference at birth (t = 9.555), hospitalization duration (Z = -3.930) and the median number of day for total using EN (Z = -3.004). The relationship between EUGR and some risk factors was analyzed with Logistic regression model. Assessed by the weight, the following 4 factors were related to EUGR: sex (chi(2) = 10.351), gestation age at birth (chi(2) = 56.275), birth weight (chi(2) = 102.126) and different hospital (chi(2) = 4.773). Assessed by the head circumference, the following 2 factors were correlated: gestation age at birth (chi(2) = 10.322) and head circumference (chi(2) = 10.620).</p><p><b>CONCLUSIONS</b>This study showed that the incidence of EUGR in premature neonates was significantly higher than the data reported in other countries. The incidence of EUGR increased with the decreased birth weight. Different nutritional support had influence on EUGR.</p>