[Clinical effects of in situ perforation of preserved split scar matrix in combination with scalp transplantation and vacuum sealing drainage in the treatment of hypertrophic scar in non-functional sites after burns]

Objective: To investigate the clinical effects of in situ perforation of preserved split scar matrix in combination with scalp transplantation and vacuum sealing drainage in the treatment of hypertrophic scar in non-functional sites after burns. Methods: A retrospective observational study was used. From June 2017 to June 2019, 33 patients (24 males and 9 females, aged 8-50 years) who met the inclusion criteria with hypertrophic scars in non-functional sites outside the face after burns were treated in General Hospital of TISCO (the Sixth Hospital of Shanxi Medical University). All patients underwent scalp transplantation after perforation of retained split scar matrix in situ (with scar thinning area of 90-500 cm2), and then the vacuum sealing drainage was performed. The hematoma and infection of wounds were observed on the 7th day after operation. At the same time, the survival rate of skin grafting was observed and calculated. The flatness and thickness of the scar in the operative area were observed in 12 months after operation, and the itching and pain of the patients were recorded. Vancouver Scar Scale was used to score the scar of patients before operation and at 3, 6 and 12 months after operation. The healing time and hair growth of donor site were observed. Data were statistically analyzed with repeated analysis of variance, paired sample t test and bonferroni correction. Results: On the 7th day after operation, local subcutaneous hematoma appeared in the wound of 2 patients, which healed after dressing change; no infection occurred. On the 7th day after operation, the survival rate of skin grafting of patients was 94.6%-99.0%(96.8±1.2)%. Scar flatness was well, the thickness of scar was not significantly higher than that of normal skin in 12 months after operation, and the symptoms of itching pain of patients disappeared or significantly relieved. Vancouver Scar Scale scores of patients before operation and at 3, 6, and 12 months after operation were 12.1±2.8, 8.5±1.5, 7.6±1.6, 6.7±1.3, respectively, and the scores of 3, 6, and 12 months after operation were all significantly lower than that before operation (with t values of 4.48, 4.06, and 3.97, respectively, P<0.01). All the donor sites of the head healed well in 4-7 days after operation. By 3-6 months after operation, all patients had good hair growth in the donor site and achieved no scar healing. Conclusions: The treatment of hypertrophic scar in non-functional sites outside the face after burns by in situ perforation of preserved split scar matrix in combination with scalp transplantation and vacuum sealing drainage can effectively improve the appearance of hypertrophic scar in non-functional areas after burn and reduce its degree of hyperplasia, with scar-free donor site healing.

[Interventional effects of BAY11-7082 on lung inflammatory response at the early stage and acute lung injury of rats with severe burns]

Objective: To investigate the interventional effects of BAY11-7082 on lung inflammatory response at the early stage and acute lung injury of rats with severe burns. Methods: (1) Experiment 1. Twelve Sprague-Dawley (SD) rats were divided into control (C) group and burn (B) group according to the random number table, with 3 rats in group C and 9 rats in group B. Rats in group C did not receive any special treatment. Rats in group B were inflicted with 30% total body surface area full-thickness burn on the back. Immediately after injury, rats in group B were intraperitoneally injected with normal saline in the dosage of 50 mL/kg. Abdominal aorta blood and lung tissue samples were collected from three rats in group B at post injury hour (PIH) 12, 24, and 48, respectively. The interleukin-1β (IL-1β) and the IL-18 content of serum were determined with enzyme-linked immunosorbent assay. The mRNA expressions of IL-1β and IL-18 in lung tissue were determined with real-time fluorescent quantitative reverse transcription polymerase chain reaction (RT-PCR). Sample collection and determination in rats of group C were performed as above. (2) Experiment 2. Eighteen SD rats were divided into control (C) group, simple burn (SB) group, and BAY11-7082 intervention (BI) group according to the random number table, with 6 rats in each group. Rats in group C did not receive any special treatment. Rats in groups SB and BI were inflicted with injury as in experiment 1. Immediately after injury, rats in group SB were intraperitoneally injected with normal saline in the dosage of 50 mL/kg, and those in group BI with 8 mg/mL (final mass concentration) BAY11-7082 solution in the dosage of 50 mL/kg. Lung tissue and bronchoalveolar lavage fluid (BALF) of rats with burns were collected at the optimal observation time point concluded from experiment 1. The morphology of lung tissue was observed with hematoxylin-eosin staining, and the pathological damage of lung tissue was graded. The myeloperoxidase (MPO) content of lung tissue and the total protein content of BALF were detected by microplate reader. The protein expressions of nucleotide-binding oligomerization domain-like receptor-3 (NLRP3) and cysteine-aspartic proteases 1 (caspase-1) in lung tissue were determined with Western-blotting. The mRNA expressions of IL-1β, IL-18, NLRP3, and caspase-1 in lung tissue were determined with real-time fluorescence quantitative RT-PCR. Sample collection and determination in rats of group C were performed as above. Data were processed with one-way analysis of variance and LSD-t test. Results: (1) The IL-1β and IL-18 content of serum in rats of group B at PIH 12, 24, and 48 were significantly higher than those of group C (t=10.55, 22.05, 12.47, 10.60, 15.22, 11.94, P<0.01). The mRNA expressions of IL-1β and IL-18 in rats of group B at PIH 12, 24, and 48 were significantly higher than those of group C (t=3.62, 7.19, 5.28, 3.20, 12.62, 7.31, P<0.05 or P<0.01). PIH 24 was the optimal observation time point for the following experiment. (2) At PIH 24, compared with those in group SB, the inflammatory cell infiltration and erythrocyte exudates of alveolar in group BI were obviously reduced, and the pulmonary interstitial edema obviously subsided. The pathological damage score of lung tissue in rats of group SB was (9.00±1.00) points, significantly higher than (1.10±0.26) points of group C (t=13.23, P<0.01). The pathological damage score of lung tissue in rats of group BI was (4.93±0.70) points, which was significantly lower than that of group SB (t=5.76, P<0.01) but still significantly higher than that of group C (t=8.84, P<0.01). At PIH 24, the MPO content of lung tissue and the total protein content of BALF in rats of group SB were (1.83±0.15) U/mg and (1.39±0.20) mg/mL, respectively, significantly higher than (0.51±0.10) U/mg and (0.44±0.05) mg/mL of group C (t=12.50, 7.86, P<0.01). The MPO content of lung tissue and the total protein content of BALF in rats of group BI were (0.91±0.12) U/mg and (0.60±0.10) mg/mL, respectively, significantly lower than those of group SB (t=8.36, 6.06, P<0.01). At PIH 24, the protein expressions of NLRP3 and caspase-1 in lung tissue of rats of group SB were 3.10±0.09 and 2.99±0.30, respectively, significantly higher than 1.00 and 1.00 of group C (t=9.06, 11.28, P<0.01). The protein expressions of NLRP3 and caspase-1 in lung tissue of rats of group BI were 1.13±0.08 and 1.81±0.11, respectively, significantly lower than those of group SB (t=7.24, 3.91, P<0.05 or P<0.01). At PIH 24, the mRNA expressions of IL-1β, IL-18, NLRP3, and caspase-1 in lung tissue of rats in group SB were 5.0±0.4, 3.32±0.21, 3.54±0.42, and 6.3±1.0, respectively, significantly higher than 1.0, 1.00, 1.00, and 1.0 of group C (t=13.97, 14.14, 11.78, 7.13, P<0.01). The mRNA expressions of IL-1β, IL-18, NLRP3, and caspase-1 in lung tissue of rats in group BI were 2.6±0.5, 2.00±0.28, 1.39±0.21, and 2.5±0.5, respectively, significantly lower than those of group SB (t=7.11, 5.80, 9.99, 4.65, P<0.05 or P<0.01). Conclusions: Applying BAY11-7082 at the early stage of acute lung injury of rats with severe burn can reduce the expression of caspase-1, decrease the levels of IL-1β and IL-18, and decrease the MPO content of lung tissue and the total protein content of BALF through inhibiting NLRP3, thus alleviating the lung inflammatory response and lung injury.

First Report of Fusarium equiseti Causing a Sheath Rot of Corn in China

Corn is the most important cereal crop in China. Over 34.94 million ha of corn is cultivated in the country annually. However, fungal diseases are a major limiting factor in corn production. In August 2008, 50 ha in several corn fields in Liaoning, Jilin, and Heilongjiang provinces were observed to be severely affected by a disease causing a yield loss of 30%. Results from field surveys suggested an epidemic during late corn growth stages that affected corn sheaths, causing irregularly circular spots with grayish brown to dark brown lesions. Lesions ranged from 2.5 to 3 × 3 to 5 cm. To isolate the causal agent, tissue was removed from the border of lesions and surface sterilized in 75% ethanol for 30 sec and 0.1% HgCl₂ for 1 min. The sample was then triple rinsed in sterile distilled water. The isolate was purified and subcultured on potato dextrose agar (PDA) at 25 ± 2°C. The initial color of the mycelium was white, turning brown after being cultured for 7 days. A pale brown to dark brown pigment developed in the agar beneath the colony. Chlamydospores, solitary but also in short chains, measuring 7.2 to 15.3 μm, were produced on carnation leaf agar (CLA) after 10 days and became verrucose 20 days later. Macroconidia were produced on CLA in orange sporodochia from monophialides on branched conidiophores, usually 5- to 7-septate, and apical cells were tapered and elongate. Basal cells were prominent, foot-shaped, and elongated in appearance. Microconidia were not observed (1). These morphological characteristics matched the description of Fusarium equiseti reported by Leslie and Summerell (1). A pathogenicity test was conducted with an isolate from each of the 36 corn plants by spraying 2 ml of spore suspension (10⁶ conidia/ml) on 45-day-old corn sheaths (cv. Huang Zao). For the control treatment, 36 corn plants were sprayed with an equal volume of sterilized water. Inoculated plants were placed in a greenhouse at 32 to 34°C and 95% relative humidity. Typical irregularly circular lesions were observed 7 days after inoculation, except in the control samples. Each treatment was replicated three times. The suspected pathogen was consistently re-isolated from diseased tissue according to Koch's postulates, and was found to be morphologically similar to F. equiseti. Preliminary morphological identification of the fungus was confirmed by a PCR assay using genomic DNA extracted from the mycelia of a 7-day-old culture on PDA at 25 ± 2°C. A 750-bp amplified region of the transcription elongation factor (TEF) of rDNA was generated using TEF1 (5'-ATGGGTAAGGAGGACAAGAC-3') and TEF2 (5'-GGAAGTACCAGTGATCATGTT-3') primers. The TEF region (GenBank Accession No. KF754798) was sequenced by Sangon Biotech Co., Ltd. (Shanghai, China) and displayed 99% nucleotide similarity with the rDNA-TEF of F. equiseti (JN127347.1) separately after a BLASTn search in GenBank. Based on the symptoms, fungal morphology, TEF sequence, and pathogenicity testing, this fungus was identified as F. equiseti. To our knowledge, this is the first report of F. equiseti on corn sheaths in China. This report will establish a foundation for further study of F. equiseti to address the disease effectively and to determine the severity of damage caused by F. equiseti. Reference: (1) J. F. Leslie and B. A. Summerell. The Fusarium Laboratory Manual. Blackwell, Ames, IA, 2006.

First Report of Elm Yellows Subgroup 16SrV-B Phytoplasma as the Cause of Rose Balsam Phyllody in China

Rose balsam (Impatiens balsamina L.) is an ornamental species frequently cultivated in China and the red flower is often used as nail polish in rural regions. The phytoplasmas previously reported with rose balsam phyllody in China have been classified as aster yellows group (16SrI) (1). In August 2012, some rose balsams were observed with typical phytoplasma symptoms in Handan City, Hebei Province, China, with an incidence of about 70% in the fields. The flowers turned green and petals fascicled. The new leaves wrinkled and deformed and internodes shortened. Infected plants were stunted, matured prematurely, and failed to produce seeds. To confirm phytoplasma infection, 100 mg of plant tissue (leaves, petals) was collected from five symptomatic and four asymptomatic plants and total DNA was extracted using a modified cetyltrimethylammonium bromide (CTAB) method (2). The 16S rDNA gene was amplified by nested PCR using primer pair P1/P7 followed by R16F2n/R16R2 (3). No amplicons were generated with DNA from asymptomatic samples, but amplicons of approximately 1.2 kb were obtained with DNA from five symptomatic samples. The amplified products were purified with aTIANgel midi purification kit (Tiangen, Beijing) and sequenced at the Sangon Biotech facility (Shanghai, China). The sequences of the amplicons were 100% identical and deposited in NCBI GenBank (Accession No. KC993832). The 16S rDNA gene sequence from this phytoplasma was 99% similar to Jujube witches broom phytoplasma (JQ675716), Puna chicory flat stem phytoplasma (JN582266), Plum yellows phytoplasma (FJ459914), and other elm yellows group phytoplasmas by BLAST search of the NCBI database. Restriction fragment length polymorphism (RFLP) analyses were carried out by digesting the 1.2-kb R16F2n/R16R2 nested PCR product with restriction enzymes AluI, RsaI, HhaI, HpaI, Eco RI, TaqI, HaeIII, HinfI, and KpnI (Takara, Dalian). The 16S rDNA RFLP patterns matched that of Jujube witches broom phytoplasma (JWB, subgroup 16SrV-B) (4). Nucleotide sequences of rose balsam phyllody were analyzed by iPhyClassifier software, which revealed that it had maximum similarity to the reference pattern of 16Sr group V, subgroup B (AB052876). All samples were detected with transmission electron microscopy. The results showed phytoplasma-like cells in phloem sieve element of symptomatic plants, while no phytoplasma-like cells were observed in healthy phloem tissues. The phytoplasma cells ranged from 230 to 470 nm in diameter and were ellipsoidal or orbicular with visible membranes. Combining the RFLP pattern and sequence analysis by iPhyClassifier, we classified the phytoplasma causing rose balsam phyllody into subgroup 16SrV-B. To our knowledge, this is the first report of 16SrV-B group phytoplasmas infecting rose balsam in China. References: (1) Z. N. Li et al. J. Phytopathol. 159:799, 2011. (2) M. A. Saghai-Maroof et al. Proc. Natl. Acad. Sci. 81:8014, 1984. (3) I. M. Lee et al. Phytopathology 83:834, 1993. (4) I. M. Lee et al. Int. J. Syst. Bacteriol. 48:1153, 1998.

Cytomegalovirus immediate-early promoter efficiently drives heterogeneous gene expression in Spodoptera frugiperda (Sf9) insect cells

Recently, wide attention has been given to the potential of recombinant baculovirus as a gene transfer vehicle for mammalian gene therapy. In this study, we packaged the recombinant baculoviruses with cytomegalovirus immediate-early (CMV-IE) promoter in Spodoptera frugiperda (Sf9) insect cells, and found that the CMV-IE promoter could efficiently drive the exogenic gene expression in the cells 12 h post-infection (h.p.i.). The expression level at 72 h.p.i. was only around half of that driven by polyhedrin promoter (Ppolh). However, the biological activity of the reporter proteins at 72 h.p.i. were similar with that driven by Ppolh. In addition, the Sf9 cells transfected with CMV-IE-containing plasmids also expressed foreign genes, suggesting that the CMV-IE-directed heterogeneous gene expression in the Sf9 cells was baculovirus-independent. These results demonstrate that the CMV-IE promoter might be used as a regular promoter in Sf9 cells.

First Report of Bipolaris papendorfii Causing Corn Leaf Spot in China

Corn is the most important cereal crop in China, with over 34.94 million ha being cultivated in the country annually. However, fungal diseases are a major limiting factor in corn production. In August 2012, 20 ha of corn fields in Anhui Province were found to be heavily infected by fungi. The margin of the lesion was achlorotic, and the middle was yellowish white or off-white, which was similar to the corn Curvalaria leaf spot. The oval lesions were approximately 5 to 7 mm. Lesion tissue was removed from the border between symptomatic and healthy tissue. The surface was sterilized in 75% ethanol for 30 s and 0.1% HgCl₂ for 1 min, after which the sample was washed three times in sterile distilled water. The isolate was purified and subcultured on potato dextrose agar (PDA) at 25 ± 2°C. The initial color of the colony was light brown, turning dark brown after being cultured for 7 days. The conidia were boat-shaped or inverted pear-shaped and were clearly bent to one side. The cells of both ends were slightly lighter and respectively ranged from 34.5 to 44.0 μm and 12.0 to 21.0 μm away from the base, with the second cell as the widest. The majority conidia had three or four false septates; isolates produced light brown to medium brown conidiophore, scattered or clustered, often branching, and exhibited bending. These morphological characteristics matched with the description of Bipolaris papendorfii reported by Zhang (3). A pathogenicity test was conducted with the two isolates on each of the 36 corns by spraying 2 ml spore suspension (10⁶ conidia/ml). For the control treatment, 36 corns were inoculated with an equal volume of sterilized water. Inoculated plants were placed in a greenhouse from 29 to 33°C and 95% relative humidity. The typical 5 to 7 mm oval lesions were observed 7 days after inoculation, except on the control samples. Three replications of 36 corns were used for each treatment. The isolate was consistently 100% reisolated from the diseased tissue according to Koch's postulate. The isolate was found to be morphologically similar to B. papendorfii. Preliminary morphological identification of the fungus was confirmed by PCR assay using genomic DNA extracted from the mycelium of a 7-day-old culture on PDA at 25 ± 2°C. A 550-bp amplified region of the internal transcribed spacer (ITS) of rDNA was generated using ITS1 (5'-TCCGTAGGTGAACCTGCGG-3') and ITS4 (5'-TCCTCCGCTTATTGATATGC-3') universal primers (1). The ITS region (GenBank Accession No. KC592365) was then sequenced by Sangon Biotech (Shanghai, China), and displayed 99% nucleotide similarity with the rDNA-ITS of B. papendorfii (JQ753972.1) separately after BLASTn research in GenBank. Based on the symptoms, fungal morphology, ITS sequence, and pathogenicity testing, this fungus was identified as B. papendorfii. The pathogen could reportedly infect tobacco and cotton (2). To our knowledge, this is the first study to report that B. papendorfii can infect corn in China. This report will establish a foundation for the further study of B. papendorfii to address the disease effectively. Further studies will be conducted to determine the incidence of the disease and the severity of damage caused by B. papendorfii as well as determine a possible mode for controlling the spread of the disease. References: (1) Y. J. Cao et al. Chin. J. Trop. Crops 31:1098, 2010. (2) H. Deng et al. Mycosystema 21:327, 2002. (3) T. Y. Zhang. Chin. Fungi Chi. 30:21, 2010.

First Report of Elm Yellows Subgroup 16SrV-B Phytoplasma Infecting Chinese Tulip Tree in China

Chinese tulip tree (Liriodendron chinensis) is native to China and is planted all around the country as an ornamental tree. In July of 2011, some Chinese tulip trees with typical phytoplasma symptoms were found in Baoding City, Hebei Province, China. Symptoms included yellowing of leaves, slow decline, little leaves, and death of entire plants. To confirm phytoplasma infection of these plants, total DNA was extracted from 100 mg of fresh leaf midribs collected from leaves of nine symptomatic and eight asymptomatic plants with a plant DNA extract kit (Tiangen, Beijing, China) according to the manufacturer's protocols. Using 16S rRNA phytoplasma universal primer pairs P1/P7 followed by R16F2n/R16R2, a nest PCR was carried out (1,2). The results showed that the phytoplasma was only detected in symptomatic samples by nested PCR, while the asymptomatic were negative. An approximate 1.2-kb specific fragment was obtained from the DNA of nine symptomatic plants, but no product was amplified from the leaves of eight healthy ones. The amplified products were cloned and sequenced. The sequence was deposited in GenBank Data Libraries under Accession No. JQ585925 and shared the highest homology of 99% with Puna chicory flat stem phytoplasma (GenBank Accession No. JN582266), Apricot leaf roll phytoplasma (GenBank Accession No. FJ572660), Jujube witches'-broom phytoplasma (GenBank Accession No. AY197661), and other elm yellows group phytoplasmas by BLAST analysis with that of other phytoplasmas from GenBank. Meanwhile, the sequence data was analyzed by iPhyClassifier software and the result showed that the 16S rDNA F2nR2 fragment was identical (similarity coefficient 1.00) to the reference patterns of 16Sr group V, subgroup B (GenBank Accession No.AB052876) (3). Combining the BLAST analysis in GenBank and the analysis of iPhyClassifier, we classified the phytoplasma causing Chinese tulip tree yellow leaves disease into subgroup 16SrV-B. To our knowledge, this is the first report of the 16SrVB group phytoplasmas infecting Chinese tulip tree in China. References: (1) I. M. Lee et al. Int. J. Syst. Bacteriol. 48:1153, 1998. (2) I. M. Lee et al. Int. J. Syst. Evol. Microbiol. 54:337, 2004. (3) Y. Zhao et al. Int. J. Syst. Evol. Microbiol. 59:2582, 2009.

Dominant negative effect of a germ-line mutant p53: a step fostering tumorigenesis

Lysates derived from the fibroblasts of individuals who are homozygous for normal p53 or heterozygous for the germ-line p53 mutation characteristic of certain Li-Fraumeni cancer-prone families were assessed for p53 function utilizing the binding of p53 protein to a p53-specific consensus oligonucleotide sequence. As expected, control nuclear lysates containing only mutant p53 or no p53 displayed little or no such binding. However, the nuclear lysates from heterozygous fibroblasts containing similar amounts of normal p53 and 245D mutant p53 displayed binding that was significantly below 50% of that seen with homozygous wild-type p53 in normal cell lysates. The nuclear lysates of these heterozygous or homozygous fibroblasts exhibited similar levels of DNA binding to a consensus oligonucleotide specific for the transcription factor, AP-1. These results indicate that mutant p53 has a transdominant effect on the binding of DNA by normal p53. These findings also suggest that p53 complexes formed in vivo that contain mutant p53 are functionally impaired even if normal p53 is also present in the complex. The implications of a trans-dominant effect of mutant p53 on the cancer-prone phenotype of individuals heterozygous for mutated p53 in Li-Fraumeni families is discussed.