[Applications of Geostatistical Analyses and Stochastic Models to Identify Sources of Soil Heavy Metals in Wuqing District, Tianjin,China].

A survey on soil samples was conducted to study the heavy metal pollutions and their potential sources in Wuqing District, Tianjin, China. A total of 578 topsoil samples were collected and the concentrations of eight heavy metals, namely, Cd, Pb, Cu, Zn, Cr, Ni, As (metalloid) and Hg were analyzed. A summary of descriptive statistics, principal component analysis, geostatistical analysis and stochastic forest regression models were applied to study the spatial and temporal variation and identify proportional contribution from either natural or anthropogenic sources for the eight heavy metals in topsoils of the study region. The results indicated that the average concentrations of all the heavy metals except for Cr in the topsoils exceeded their corresponding natural-background values. As, Ni and Cr were mainly contributed by natural sources (i.e., soil parent materials). Cu and Zn originated from both the soil parent materials and sewage irrigation. Pb and Cd originated mainly from non-point source pollution and partially from point source. Hg originated from sewage irrigation. It was proved that combination of multi-technologies provides an effective way to delineate multiple heavy metal pollution sources.

[The effect of aloesin on melanocytes in the pigmented skin equivalent model].

OBJECTIVE: To observe the effect of aloesin, tea polyphenols, arbutin on melanocytes in the pigmented skin equivalent model. METHODS: First, we constructed the pigmented skin equivalent model in vitro. And then we detected the effect of aloesin, tea polyphenols and arbutin on the cells' shape, tyrosinase activity and formation of melanin in the constructed pigmented skin equivalent. RESULTS: Three depigmenting agents showed an inhibition effect on the tyrosinase activity of melanocytes and reduced significantly melanin content in the pigmented skin equivalent model, in which the tea polyphenols had the strongest effect, and then was the aloesin. But the tea polyphenols showed the strongest toxicity, while the aloesin and arbutin had a much lower toxicity. CONCLUSIONS: All the three depigmenting agents showed a concentration dependent suppression effect on the tyrosinase activity and formation of melanin, in which the tea polyphenols was the strongest effect( P <0.05). Aoesin has a good suppression effect on the tyrosinase activity and formation of melanin, but has a much lower toxicity, which could be used as a safe depigmenting agent.

[Construction of an in vitro equivalent of the pigmented skin].

OBJECTIVE: To construct an in vitro equivalent of the pigmented skin using tissue engineering methods. METHODS: Surgically removed foreskins was used as the source of keratinocytes and melanocytes harvested by routine tissue digestion. The fibroblasts were enriched by tissue block culture and seeded into the scaffold constructed using mouse tail collagens to construct the pigmented skin equivalent model. The general structure and the melanocyte distribution and growth status in this model were observed with HE staining and Fontana Masson staining. The ultrastructure of the constructed pigmented skin equivalent was observed by transmission electron microscope. RESULTS AND CONCLUSION: The pigmented skin equivalent model was structurally intact, and allowed optimal cell growth. Fontana Masson staining identified in the basal layer numerous melanocytes in normal growth, and the constructed model was structurally similar to normal skin tissue, suggesting successful construction of the pigmented skin equivalent model.

[The experimental study of lipo-sodium morrhuate promoting apoptosis of ECV-304 cells].

OBJECTIVE: To evaluate the effect of lipo-sodium morrhuate on ECV-304 cell line. METHODS: The effect lipo-sodium morrhuate was evaluated by toxicology trial (MTT), electron microscope, DNA electrophoresis and flow cytometer. RESULTS: The toxicology results showed, that the number of vital cells in lipo-sodium morrhuate group decreased slowly. The electron microscope exhibited apoptosis in the lipo-sodium morrhuate group. And there were typical DNA ladder in DNA electrophoresis and typical apoptosis peak in flow cytometer. The apoptosis rate was 22.23%. CONCLUSIONS: Unlike the normal preparation of sodium morrhuate, lipo-sodium morrhuate could induce apoptosis of ECV-304 cell line.

[Early operative treatment of pelvic fractures associated with urethral disruption].

OBJECTIVE: To evaluate the early operative treatment and clinical results of pelvic fractures associated with urethra disruption. METHODS: From January 1995 to January 2005, 25 patients suffered from pelvic fractures combined urethra disruption treated by operation were retrospectively analyzed. According to Tile's classification, 1 case was stable pelvic fracture, 17 rotational unstable fractures, and 7 rotational combined vertical unstable fractures. The complete urethra rupture were in 23 cases and incomplete in 2 cases. The operative methods included: (1) emergency open reduction and internal fixation of the pelvis combined primary urethra suturing in 2 cases, partial suturing after realignment in 4 cases, realignment in 2 cases, and urethrovaginal penetrating wound repairing in 1 case; (2) primary urethra realignment only and delayed (range, 7 to 21 days) pelvic internal fixation in 10 cases; (3) early cystostomy and delayed (range, 3 to 21 days) urethra realignment and pelvic internal fixation in 6 cases. RESULTS: The mean follow-up time of all patients was 34 months (range from 6 to 120 months). According to Majeed's evaluation, 17 cases of pelvic injury showed excellent results, 5 good, and 3 fare. After urinary catheter removed, the mean maximal urine flow rate of 19 (76%) patients was 18.6 ml/s and the mean scar length between both disrupted ends on the film of excretion urethrography was 0.51 cm. Five (20%) cases suffered in dysuria needed urethral dilatation or further surgery. One (4%) female could not control urination who need a second-look operation. The primary suprapubic soft tissue avulsion wound infection secondary to retropubic abscess was found in 1 case, posterior urethra-stenosis in 5 cases, sexual impotence in 3 cases, and incontinence in 1 case. CONCLUSIONS: The satisfactory reduction and effective fixation of the pelvic fractures is an anatomical basis for receiving "tension-free urethral anastomosis".

[Compare the effect of lipo- and normal prepared Sodium Morrhuate on ECV-304 cell line].

OBJECTIVE: To compare the effect of Sodium Morrhuate on ECV-304 between its lipo- and normal preparation. METHODS: The ECV-304 cell line was supplemented with Sodium Morrhuate and lipo-Sodium Morrhuate in order, and the result on morphology (microscope, Giemsa Staining and electron microscope), cell activity (MTT), and flow cytometer between the two preparation were compared. RESULTS: In normal preparation group, cell's edema occurred. Chromatin was like catkins. Tumefaction and degeneration of mitochondrion and endoplasmic reticulum appeared. In lipo-Sodium Morrhuate group, the membrane was creased and processus appeared. Chromatin aggregates to the membrane of nucleus was like crescent, and then broken. The apoptotic body was formed. MTT changes showed that the curve of the normal preparation group was steep and the change time was short relatively, which cues the vital cells decreased sharply. The curve of lipo-Sodium Morrhuate group was gentle and the change time was long relatively, which cues the vital cells decreased slowly. The flow cytometer showed that typical apoptosis peak appeared. CONCLUSION: The normal preparation group shows an acute toxic effect on ECV-304 cell line, which result in a necrosis course, while lipo-Sodium Morrhuate shows a gradual releasing process, which may indicate a apoptosis course.

[Experimental study on induction of the normal human melanocytes apoptosis in vitro by cycloheximide and TNF-alpha].

OBJECTIVE: To investigate the effects of cycloheximide and TNF-alpha on melanocyte (MC). METHODS: Melanocyte apoptosis was studied with MTT, transmitting electron microscopy and fluorescence labeling of alive cells. RESULTS: We added TNF-alpha and cycloheximide in melanocytes, and the typical apoptosis appeared 24 hours later, with chromatin condensation, nuclear pyknosis and apoptotic bodies formation. The results of cytometry showed the typical apoptotic peak. CONCLUSION: TNF-alpha and cycloheximide together could inhibit MC proliferation and induce MC apoptosis.