[Prospective randomized controlled study on clinical effects of autologous skin paste in repairing medium-thickness skin donor site wounds].

Objective: To explore the clinical effects of autologous skin paste in repairing medium-thickness skin donor site wounds. Methods: The prospective randomized controlled research method was applied. From October 2018 to December 2019, 18 patients with flame burn or hydrothermal scald, conforming to the inclusion criteria were admitted to Jinhua Hospital Affiliated to Zhejiang University School of Medicine, including 15 males and 3 females, aged (45±6) years. The wounds were repaired with medium-thickness skin grafts from thigh, and the wound area was (121±33) cm2 after medium-thickness skin grafting. The medium-thickness skin donor site wound in each patient was divided into 2 wounds in equal area and allocated into autologous skin paste group and conventional treatment group by flipping a coin, with 18 wounds in each group. The wounds in autologous skin paste group were repaired with skin paste prepared with remaining skin fragments after autologous medium-thickness skin grafting, and the wounds in conventional treatment group were covered with petroleum jelly gauze and fixed with sterile gauze. On 3, 7, 14, and 21 d after operation, the wound healing in 2 groups was observed, and the wound healing rate was calculated. The wound healing time in 2 groups was recorded. Occurrences of wound subcutaneous effusion and infection on 3, 7, 14, and 21 d after operation and wound ulceration in 3 months after operation were observed. In 6 months after operation, the Vancouver Scar Scale (VSS) was used to evaluate the scar formation of wounds in 2 groups. Data were statistically analyzed with analysis of variance for repeated measurement, chi-square test, and group t test. Results: The wounds in 2 groups did not heal on 3 and 7 d after operation. The wound healing rate in autologous skin paste group was (29.8±2.5)% and (95.6±4.7)% on 14 and 21 d after operation, which were significantly higher than (25.8±2.9)% and (82.6±8.9)% in conventional treatment group (t=4.3, 5.6, P<0.01). The wound healing time in autologous skin paste group was (21.8±1.6) d, which was significantly shorter than (25.6±2.0) d in conventional treatment group (t=6.24, P<0.01). On 3, 7, 14, and 21 d after operation, there were no complications such as subcutaneous effusion or infection in wounds of 2 groups. In 3 months after operation, ulceration occurred in wounds of 2 patients in autologous skin paste group, which was significantly less than 12 patients in conventional treatment group (χ2=11.688, P<0.01). The ulcerated wounds healed after dressing changes. In 6 months after operation, the VSS score of wounds in autologous skin paste group was (9.1±1.1) points, which was significantly lower than (11.3±1.2) points in conventional treatment group (t=-5.75, P<0.01). Conclusions: The remaining skin fragments after autologous medium-thickness skin grafting prepared into skin paste to repair medium-thickness skin donor site wounds can shorten wound healing time, improve wound healing quality, and reduce degree of scar hyperplasia, with a good clinical effect.

[Effect of autologous skin paste on repairing wound of donor site of medium-thickness skin graft].

Objective: To explore the effect of autologous skin paste on repairing wound of medium-thickness skin donor site. Methods: The prospective randomized controlled research method was applied. From October 2018 to December 2019, 18 patients with flame burn or hydrothermal scald, met the inclusion criteria were admitted to Jinhua Hospital Affiliated to Zhejiang University School of Medicine, including 15 males and 3 females, aged (45±6) years, and the wounds were repaired with medium-thickness skin grafts. The wound area after medium-thickness skin grafting was (121±33) cm2. The wound of donor site of medium-thickness skin graft in each patient was divided into 2 wounds in equal area and included into autologous skin paste group and conventional treatment group with random number table, with 18 wounds in each group.The wounds in autologous skin paste group were repaired with skin paste prepared with remaining skin fragments after autologous medium-thickness skin grafting, and the wounds in conventional treatment group were repaired with petroleum jelly gauze and sterile gauze. On 3, 7, 14, 21 d after operation, the wound healing in 2 groups was observed, and the wound healing rate was calculated. The wound healing time in 2 groups was recorded. Occurrences of subcutaneous effusion and infection on 3, 7, 14, 21 d after operation and wound rupture in 3 months after operation were observed. In 6 months after operation, the Vancouver scar scale (VSS) was used to evaluate the scar formation of wounds in 2 groups. Data were statistically analyzed with analysis of variance for repeated measurement, chi-square test, and group t test. Results: The wounds in 2 groups did not heal on 3 and 7 d after operation. The wound healing rate in autologous skin paste group was (29.8±2.5)% and (95.6±4.7)% on 14 and 21 d after operation, which were significantly higher than (25.8±2.9)% and (82.6±8.9)% in conventional treatment group (t=4.3, 5.6, P<0.01). The wound healing time in autologous skin paste group was (21.8±1.4) d, which was significantly shorter than (25.6±2.0) d in conventional treatment group (t=6.24, P<0.01). On 3, 7, 14, 21 d after operation, there were no complications such as subcutaneous effusion and infection in wounds of 2 groups. In 3 months after operation, ulceration occurred in wounds of 2 patients in autologous skin paste group, which was significantly less than 12 patients in conventional treatment group (χ2=11.688, P＜0.01). The wounds with ulceration healed after dressing change. In 6 months after operation, the VSS score of wounds in autologous skin paste group was (9.1±1.1) points, which was significantly lower than (11.3±1.2) points in conventional treatment group (t=-5.75, P＜0.01). Conclusion: The remaining fragments after autologous medium-thickness skin grafting are prepared into skin paste to repair wound of donor site of medium-thickness skin graft can shorten wound healing time, improve wound healing quality, reduce degree of scar hyperplasia, which has a good clinical effect.

[Integration of spatial epidemiology and molecular epidemiology used for study on tuberculosis].

Spatial epidemiology and molecular epidemiology have been widely used in the studies of tuberculosis (TB), but each with limitations. Integration of the two methods provides new ideas and methods in TB research. All referenced articles are from CNKI, Wan Fang database, PubMed database and Web of Science database. Method of combining spatial epidemiology and molecular epidemiology has been widely used in determining the local epidemic strains of TB genotype, the transmission mechanism, risk factors of TB, drug-resistant TB, as well as evaluating the effectiveness of TB prevention and control measures. Application of the combined methods is of important significance in the studies of TB, thus worthy to be further introduced to researchers and disease prevention and control workers in this country.

Multi-GeV electron beams from capillary-discharge-guided subpetawatt laser pulses in the self-trapping regime.

Multi-GeV electron beams with energy up to 4.2 GeV, 6% rms energy spread, 6 pC charge, and 0.3 mrad rms divergence have been produced from a 9-cm-long capillary discharge waveguide with a plasma density of ≈7×10¹7 cm⁻³, powered by laser pulses with peak power up to 0.3 PW. Preformed plasma waveguides allow the use of lower laser power compared to unguided plasma structures to achieve the same electron beam energy. A detailed comparison between experiment and simulation indicates the sensitivity in this regime of the guiding and acceleration in the plasma structure to input intensity, density, and near-field laser mode profile.

Detection of a single base substitution in a single cell using the LightCycler.

For known mutations, real time polymerase chain reaction followed by melting curve analysis, using hybridization probes, is highly sensitive, rapid and an efficient approach to mutation detection. We have used this approach on the LightCycler for the detection of single base mutations in a single cell, without nested PCR. Hybridization probes were designed for two sequences in the BRCA1 gene containing a single base substitution and deletion, respectively. Polymerase chain reactions of small fragments (100-200 bp) containing the probe sequences were optimized using SYBR Green1, before using hybridization probes. The 5'-probes were 3'-labeled with FITC, whereas the 3'-probes, covering the mutation, were 5'-labeled with LC-Red640 (wild type probes) or LC-Red705 (mutant probes). Dual color detection of wild type and mutant sequences in a single tube was tested on single cells. The reaction mix was prepared in reaction capillaries and a single cell, picked by micromanipulation, was added to this mix. The DNA from the cell is released during the 5-min preheating step of the PCR, using the FastStart hybridization kit (Roche). Reproducible results were obtained, without the need of nested PCR. The technique is useful for microdissected tumors and, with other genes, has great potential for pre-implantation diagnosis in IVF and analysis of residual disease in cancer.

Interaction of misonidazole, hyperthermia, and irradiation in a C3H mammary carcinoma and its surrounding skin in vivo.

The interaction of irradiation, Misonidazole (MISO), and hyperthermia was studied in a C3H mouse mammary carcinoma and its surrounding skin in vivo. MISO (0.5-1.0 mg/g) was injected 30 min before irradiation. Hyperthermia (41.5 degrees-43.5 degrees C for 60 min) was given either simultaneously, 0.5 hr, or 4 hr after X rays. The results were evaluated as the radiation dose to achieve tumor control (TCD50) or moist desquamation of the skin (DD50) in half of the treated animals. A therapeutic gain was found when the enhancement in tumors were greater than that found in skin. The combination of simultaneous heat and irradiation caused great enhancement in radiation response, but with no therapeutic gain. A slightly lower enhancement of the damage in both tissues was found with a 30 min interval between irradiation and hyperthermia, whereas heat 4 hr after X rays gave a small, but significant therapeutic gain. MISO significantly enhanced the response in tumors but not in skin. Combined trimodality treatment with MISO, irradiation, and hyperthermia resulted in enhancement ratios up to 15, dependent on temperature, radiation-heat interval, and to a lesser extent the MISO dose. The enhancement was for all schedules most pronounced in the tumors, resulting in an improved therapeutic effect. The combination of MISO and hyperthermia may be a valuable addition to radiotherapy, especially if heat and irradiation can be applied with close interval and with one of the modalities given selectively to the tumor.

The in vivo response of a C3H mammary carcinoma to treatment with misonidazole, cyclophosphamide and radiation.

The potential chemosensitizing effect of the nitroaromatic radiosensitizer misonidazole (MISO) on the alkylating agent cyclophosphamide (CTX), and the interactions of these agents with radiation, have been investigated in a C3H mammary carcinoma in CDF1 mice. MISO at 1,000 mg/kg caused a small increase in tumour growth time (TGT; time to reach 3 times treatment volume) from 3.6 days to 4.5 days. CTX (100 mg/kg) increased the TGT to 15.7 days. The combined treatment of MISO and CTX given with intervals of either 15 min or 4 h increased the TGT to 23.3 and 23.8 days respectively. The radiation enhancement ratio (ER) was found to be 2.13 and 1.10 for MISO administered before or after x-rays respectively. The corresponding ERs for CTX were 1.16 and 1.22. The two drugs given in combination resulted in significant radiation ERs of 2.68 (both drugs given within 30 min before x-rays), 3.00 (MISO 30 min before and CTX 3 1/2 h after x-rays) and 1.40 (both drugs given after x-rays). In contrast to what has previously been reported, and in contrast to the tumour regrowth delay data, the results of the tumour control experiments were found to reflect no more than an additive action of the two drugs when used together with radiation in vivo.