Over-expression of SlJA2 decreased heat tolerance of transgenic tobacco plants via salicylic acid pathway.

KEY MESSAGE: Over-expression of SlJA2 decreased the accumulation of SA, which resulted in significant physiological and gene expression changes in transgenic tobacco plants, leading to the decreased heat tolerance of transgenic tobacco. NAC family, the largest transcription factors in plants, responses to different environmental stimuli. Here, we isolated a typical NAC transcription factor (SlJA2) from tomato and got transgenic tobacco with SlJA2 over-expression. Expression of SlJA2 was induced by heat stress (42 °C), chilling stress (4 °C), drought stress, osmotic stress, abscisic acid, and salicylic acid. Over-expression of SlJA2 decreased the accumulation of salicylic acid by regulating expression of salicylic acid degradation gene under heat stress. Compared to WT plants, stomatal apertures and water loss increased in transgenic plants, and the damage of photosynthetic apparatus and chlorophyll breakdown were more serious in transgenic plants under heat stress. Meanwhile, more H2O2 and O2·- were accumulated transgenic plants and proline synthesis was restricted, which resulted in more serious oxidative damage compared to WT. qRT-PCR analysis showed that over-expression of SlJA2 could down-regulate genes involved in reactive oxygen species scavenging, proline biosynthesis, and response to heat stress. All the above results indicated that SlJA2 may be a negative regulator responded to plant's heat tolerance. Thus, this study provides new insight into roles of NAC family member in plant response to abiotic stress.

[Effect of chorioamnionitis on brain injury in preterm infants].

OBJECTIVE: To explore the association between chorioamnionitis and brain injury in preterm infants. METHODS: A total of 88 preterm infants (28-34 weeks), who were born between June 2008 and June 2011, were divided into a case group (n=41) and a control group (n=47) according to whether or not they had chorioamnionitis. All the infants were examined by brain ultrasonography periodically after birth and underwent brain diffusion weighted imaging (DWI) between 3 and 7 days after birth. The two groups were compared in terms of the incidence of periventricular leukomalacia (PVL) and periventricular and intraventricular hemorrhage (PVH-IVH) by brain magnetic resonance imaging (MRI) at the corrected gestational age of 40 weeks. RESULTS: There was statistical significance in the incidence of PVL between the case and the control groups (32% vs 6%; P<0.05), but no significant difference in the incidence of PVH-IVH between the two groups (27% vs 23%; P>0.05). CONCLUSIONS: Chorioamnionitis is associated with brain injury in preterm infants, increasing the incidence of PVL but having little influence over the incidence of PVH-IVH.

[Treatment of osteosarcoma with TNF-related apoptosis-inducing ligand or in combination with doxorubicin in animal experiment].

OBJECTIVE: To examine the effect of TNF-related apoptosis-inducing ligand (TRAIL) and in combination with doxorubicin (ADM) to xenografted tumors in nude mice and to explore its potential mechanism. METHODS: MG-63 cells (5 x 10(6)/ml) were suspended in 0.2 ml RPMI-1640 and inoculated subcutaneously into the lower limb of nude mice. Treatment groups were given TRAIL of different concentration or combination of TRAIL and ADM intraperitoneally. Normal saline was administrated in the control group. Anti-tumor effects were estimated by tumor volumes. Serum alkaline phosphatase (ALP) was detected by ALP kits. Induction of apoptosis in xenografted tumors was confirmed by TUNEL (TdT-mediated dUTP nick end labeling) assay. Expression of Bax was detected by immunohistochemical assay. Expression of TRAIL receptors was detected by RT-PCR assay. RESULTS: Growth curve of tumors indicated that tumors carried by TRAIL-treated mice grew more slowly than that with normal saline and 2 microg TRAIL was more effective, Also tumors treated with combination of TRAIL and ADM grew more slowly than any other group. ALP activities of each group were moderately different but significance was not reached. TUNEL showed that there were more apoptotic cells in the combination group than any other group. Immunohistochemical assay showed that expression of Bax was up-regulated in the combination group. RT-PCR showed that expression of TRAIL-R2 mRNA was up-regulated in the combination group. CONCLUSION: TRAIL can induce an effective apoptosis of osteosarcoma cells in vivo in a dose-dependent fashion. ADM can enhance the effect of TRAIL-mediated apoptosis. And up-regulations of Bax and TRAIL-R2 may be the involved mechanism.

[Early use of recombinant human erythropoietin promotes neurobehavioral development in preterm infants].

OBJECTIVE: To evaluate the effect of the early use of recombinant human erythropoietin (rhu-EPO) on neurobehavioral development in preterm infants. METHODS: Forty-four preterm infants (30 males and 14 females) were randomly divided into two groups: Rhu-EPO treatment and untreated control (n=22 each). From postnatal day 7, the Rhu-EPO treatment group received intravenous rhu-EPO (250 IU/kg3 times weekly) for 4 weeks. A Neonatal Behavioral Neurological Assessment (NBNA) was performed at 40 weeks of corrected gestational age. A Gesell Development Schedule was used to evaluate neurological development 6 and 12 months after birth. RESULTS: The NBNA score in the rhu-EPO treatment group (36.20+/-0.75) was significantly higher than that in the control group (34.40+/-1.05) at 40 weeks of corrected gestational age (P<0.05). The developmental quotient of fine motor in the rhu-EPO treatment group was significantly higher than that in the control group 6 months after birth (P<0.05). By 12 months after birth, the developmental quotient of gross motor, fine motor and language in the rhu-EPO treatment group was significantly higher than that in the control group (P<0.05). CONCLUSIONS: Early use of Rhu-EPO can promote neurobehavioral development in preterm infants.

[Clinical observation of osteotomy and fusion for the treatment of severe rigid equinus deformity].

OBJECTIVE: To explore clinical efficacy of osteotomy and fusion in treating severe rigid equinus deformity. METHODS: From April 2010 to October 2015, 13 patients(16 feet) with severe rigid equinus deformity were treated with osteotomy and fusion by hollow screw, including 6 males and 7 females aged from 39 to 62 years old with an average of(49.6±5.3) years old;the courses of diseases ranged from 5 to 27 years with an average of (9.0±4.8) years. Six patients (9 feet) were treated with osteotomy and fusion for three joints, 4 patients(4 feet) were treated with osteotomy and fusion for four joints, and 3 patients (3 feet) were treated with osteotomy and fusion for tibiotalar and calcaneal-talar joints. All patients manifested as foot pain, heel could not touch floor and walking before operation. Postoperative complications were observed, AOFAS score were applied to evaluate clinical effect. RESULTS: Thirteen patients were followed up from 18 to 24 months with an average of 20 months. Only one patient occurred local skin necrosis after operation and healed by dressing change and anti-infective therapy. All feet obtained fracture healing, the time ranged from 12 to 16 weeks with an average of 13.2 weeks. AOFAS score were improved from 11.85±10.66 before operation to 81.38±3.69 after operation, and had significant difference(t=-25.67, P<0.05);15 feet good and 1 foot moderate. CONCLUSIONS: Tibiotalar and calcaneal-talar joint fusion, osteotomy and fusion for three and four joints could treat severe rigid equinus deformity according to patients' individual and could obtain satisfied clinical effects.

Overexpression of tomato SlGGP-LIKE gene improves tobacco tolerance to methyl viologen-mediated oxidative stress.

Ascorbate (AsA) is very important in scavenging reactive oxygen species in plants. AsA can reduce photoinhibition by xanthophyll cycle to dissipate excess excitation energy. GGP is an important enzyme in AsA biosynthesis pathway in higher plants. In this study, we cloned a gene, SlGGP-LIKE, that has the same function but different sequence compared with SlGGP. The function of SlGGP-LIKE gene in response to oxidative stress was investigated using transgenic tobacco plants overexpressed SlGGP-LIKE under methyl viologen treatment. After oxidative stress treatment, transgenic tobacco lines exhibited higher levels of reduced AsA content and APX activity than WT plants. Under oxidative stress, transgenic tobacco plants accumulated less ROS and exhibited lower degrees of REC and MDA. Consequently, relatively higher levels of Pn, Fv/Fm, de-epoxidation status of xanthophyll cycle and D1 protein were maintained in transgenic tobacco plants. Hence, overexpression of SlGGP-LIKE gene enhances AsA biosynthesis and can alleviate the photoinhibition of PSII under oxidative stress.

Chitosan/poly(vinyl alcohol) hydrogel combined with Ad-hTGF-ß1 transfected mesenchymal stem cells to repair rabbit articular cartilage defects.

The aim of this work is to explore the feasibility and therapeutic effect of repairing rabbit articular cartilage defects using thermo-sensitive chitosan/poly (vinyl alcohol) composite hydrogel engineered Ad-hTGF-ß1-transfected bone marrow mesenchymal stem cells. Rabbit's bone marrow stromal cells (BMSCs) were obtained and cultured in vitro and transfected with a well-constructed Ad-hTGF-ß1 vector, the cartilage phenotype of the transfected cells was tested by reverse transcription polymerase chain reaction (RT-PCR) and Western blot. Twenty-four New Zealand white rabbits with articular cartilage defects were randomly divided into four groups: group A was treated with CS/PVA gel and transfected BMSCs; group B received CS/PVA gel and un-transfected BMSCs; group C was treated with CS/PVA gel alone and group D was the untreated control group. Experimental animals of each group were killed at 16 weeks after operation. General observation, Masson's trichrome staining and collagen II immunohistological staining of the specimens were performed to evaluate the repair effect. The Wakitani scoring method was used to evaluate the repair effect. RT-PCR and Western blot confirmed that the hTGF-ß1 gene was expressed in BMSCs and triggered the expression of specific markers of cartilage differentiation such as aggrecan mRNA and Collagen II in BMSCs after transfection with Ad-hTGF-ß1. Sixteen weeks after operation, the defects in group A had smooth and flat surfaces, and the defects appeared to have completely healed, exhibiting almost the same color and texture as the surrounding cartilage. Masson's trichrome staining showed that the cell arrangement and density of regenerated cartilage tissue in group A was not significantly different from that of normal cartilage tissue. The immunohistochemical staining of Col II showed a strong expression in group A and weak expression in group B, but no expression in groups C and D. According to the Wakitani score, the difference between experimental group A and all of the other groups was statistically significant (P < 0.01). To conclude, as a thermosensitive and injectable scaffold material, CS/PVA gel engineered with BMSCs transfected with hTGF-ß1 can effectively repair rabbit articular cartilage defects.