[Best evidence summary for awake prone positioning in treating hypoxemic due to COVID-19 infection].

Objective: To retrieve, evaluate, and summarize the best evidence for the treatment of hypoxemia in patients with COVID-19 infection using the awake prone positioning, with the aim of guiding healthcare professionals in the standardized implementation of this therapy. Methods: A systematic search was conducted in databases including UpToDate, BMJ Best Practice, JBI Evidence-Based Healthcare Center, American Association of Critical-Care Nurses, Intensive Care Society, European Respiratory Society, World Health Organization website, Cochrane Library, PubMed, China National Knowledge Infrastructure (CNKI), and Wanfang. The retrieved literature was subjected to quality assessment and evidence extraction. Results: A total of ten publications were included, consisting of one thematic evidence summary, one guideline, two systematic reviews, three randomized controlled trials, and three expert consensus statements. This summary synthesizes thirty key pieces of evidence in five categories: organizational management and training, risk assessment, preparatory operations, implementation key points, and risk control. Conclusions: Awake prone positioning is beneficial for improving hypoxemia in patients with COVID-19 and is easy to implement. Medical institutions should develop nursing management systems, operational standards, and best practices for awake prone positioning based on evidence-based evidence in order to improve the quality of care management for such patients.

[Epidemiological and etiological analysis of two infantile cases of serogroup B epidemic cerebrospinal meningitis epidemics in Shandong Province, 2021].

Two cases of epidemic situation of serogroup B meningitis in infants in Shandong Province in 2021 were investigated. Samples of cases and their close contacts were collected for isolation, culture and identification of Neisseria meningitides (Nm). The isolates were subjected to multi-locus sequence typing, outer membrane protein porA and fetA genotyping and drug sensitivity test. Two laboratory-confirmed outbreaks of serogroup B meningitis were reported from Yantai city and Linyi city. The indicated cases were infants aged 5 months and 2 months old respectively. They were not vaccinated with meningitis vaccine. Their epidemiological characteristics and clinical manifestations were similar and the prognosis was good. The same sequence type (ST) of serogroup B Nm strains as the indicated cases was detected in the samples of close family contacts, but without subsequent cases. Among them, Yantai strain was were identified as the type ST-8920, belonging to CC4821 clonal complex, and the genotypes of porA and fetA were p1.21-2, 23 and F3-1. Linyi strain was a new type, belonging to CC4821 clonal complex and the genotypes of porA and fetA were p1.20, 23 and F1-91. The above strains were resistant to penicillin, ciprofloxacin, levofloxacin and Chemitrim, and their sensitivity to cephalosporin decreased. Two cases of infant serogroup B epidemic were relatively rare in China, which were different from the epidemiological and pathogenic characteristics of other Nm serogroups in the past.

Monitoring of optical emissions in laser cladding of 316L stainless steel.

Laser cladding is so complex that small disturbances may cause defects. Developing on-line monitoring technology for laser cladding is thus a priority task. Compared with expensive spectrometers and high-speed cameras, an economical optical sensing system based on two different photodiodes was established to optimize laser parameters and help monitor abnormal working conditions. In order to find optimal parameters, a series of experiments was carried out under different operating parameters such as laser power, scanning speed, and powder feeding rate. A practical rule is summarized to optimize process parameters by analyzing the time domain characteristics of the optical signal. Several experiments under different working conditions were performed to detect abnormal working conditions. Not only can an abnormal situation be recognized, but its type can also be distinguished by analyzing optical signals in the time and frequency domains. The optical sensing system provides a better understanding and accurate evaluation of laser cladding.

[Effects of free mini-flap on tibial side of third toe on repairing skin and soft tissue defect of finger pulp at the end of finger].

Objective: To investigate the effects of free mini-flap on tibial side of third toe on repairing skin and soft tissue defect of finger pulp at the end of finger. Methods: From August 2013 to May 2017, 18 patients with skin and soft tissue defect of finger pulp at the end of finger were admitted to our unit, with 12 men and 6 women aged 16 to 54 years. As the skin and soft tissue defect sites, there were 3 cases of thumb, 8 cases of index finger, 4 cases of middle finger, and 3 cases of ring finger. The area of defects ranged from 2.0 cm×1.4 cm to 3.5 cm×2.4 cm. Free mini-flaps on tibial side of third toes were designed according to area and shape of defects, and the length and width of flaps were 0.1 to 0.2 cm longer than the length and width of the defects, respectively. The area of flaps ranged from 2.1 cm×1.5 cm to 3.7 cm×2.6 cm. The end-to-end anastomosis of subcutaneous veins of flaps and superficial veins of the finger-palm side or superficial dorsal digital vein, the end-to-end tension-free anastomosis of the base metatarsal arteries on tibial side of third toe and proper digital arteries of recipient finger were performed. Besides, anastomosis of base metatarsal nerve on tibial side of third toe and proper digital nerve of recipient finger was performed. The donor sites on feet were sutured directly or repaired with full-thickness skin grafts on medial upper leg of the same side. The survival of flaps after operation and the follow-up of patients were observed. Results: All flaps survived well, with good blood supply. Among the 18 patients, 2 patients lost to follow-up, and 16 patients were followed up for 4 to 36 months. The shape and texture of flaps were good. After reconstruction, finger pulps at the end of finger were plump, with fingerprint. Function of the finger restored well, and the two-point discriminatory distances of flaps were 5 to 10 mm. The donor sites on feet of 14 patients healed after the operation, the other 2 patients had necrosis on edge and central area of skin grafts, and the necrotic area healed after dressing change. The skin graft areas on feet were wear-resistant, with slight damage to donor sites and did not influence shoes wearing and walking. Besides, patients did not feel uncomfortable. Conclusions: Skin and soft tissue defects of finger pulp at the end of finger repaired by free mini-flaps on tibial side of third toe are with good shape and slight damage to donor sites, and the operation is simple. It is worthy of popularization and application in clinic.

[Clinical effects of heel lateral flap in repair of skin and soft tissue defects at posterior heel region].

Objective: To explore the clinical effects of heel lateral flap in repair of skin and soft tissue defects at posterior heel region. Methods: From September 2007 to April 2016, 24 patients (17 males and 7 females, aged 16-70 years) with skin and soft tissue defects at posterior heel region were admitted to our department. The size of skin and soft tissue defects after debridement ranged from 3.0 cm×2.0 cm to 5.0 cm×4.0 cm. The defects were repaired with heel lateral flaps, with size ranging from 3.5 cm×2.5 cm to 6.0 cm×5.0 cm. The flaps were transferred to the donor sites through the loose subcutaneous tunnel. The donor site was repaired by full-thickness skin graft collected from inguinal region. The survival of flaps and the follow-up of patients were observed. Results: All flaps of 24 patients survived successfully. The recipient sites and donor sites were all healed. The patients all had follow-up of 6 to 24 months. At the last follow-up, the flaps were in good shape, with nearly normal color and soft texture. There were 6 cases of grade S3 sensation and 16 cases of grade S3(+) sensation. The distance of two-point discrimination of flaps ranged from 6 to 11 mm. The lateral foot skin grafts healed well, and the skin of the lateral foot was numb in the range of 4.0 cm×2.0 cm to 9.0 cm×3.0 cm. Conclusions: Heel lateral flap can not only repair the skin and soft tissue defects in the posterior region, but also reconstruct the sensory function of the posterior region. It is an ideal method to repair the skin and soft tissue defects in the posterior region.

[Effects of combined transplantation of rat Schwann cells and fibroblasts on nerve regeneration of denervated perforator flaps in rats and the mechanism].

Objective: To explore the effects of combined transplantation of the rat Schwann cells and fibroblasts (Fbs) on the nerve regeneration of denervated perforator flaps in rats and the mechanism. Methods: (1) Fbs were isolated from the trunk of 2 Sprague-Dawley (SD) rats embryos of 14-16 days' pregnancy and cultured, and the morphology of the cells was observed. The third passage of cells were used for subsequent experiments. The protein expressions of fibronectin and Ephrin-B2 were observed by immunohistochemical method. The mRNA expression of Ephrin-B2 was detected by real-time fluorescent quantitative reverse transcription polymerase chain reaction (n=3). (2) Schwann cells were isolated from the bilateral sciatic nerves and brachial plexus nerves of 45 SD rats born for 1-3 days and cultured, and the morphology of the cells was observed. The third passage of cells were used for subsequent experiments. The rate of S100 positive cells was detected by immunofluorescence method and flow cytometer, with sample numbers of 9 and 3 respectively. (3) In Dulbecco's modified Eagle medium (DMEM) high glucose medium, 1 mL Fbs and 1 mL Schwann cells both in the concentration of 1×10(5) cells/mL were co-cultured as Schwann cells+ Fbs co-culture group, and 2 mL Schwann cells in the concentration of 1×10(5) cells/mL were cultured alone as Schwann cells alone culture group, with 5 wells in each group. The clusters of Schwann cells in the two groups were observed and counted under inverted phase contrast microscope at post culture hour (PCH) 6 and 24 respectively. The clusters of Schwann cells in Schwann cells+ Fbs co-culture group were observed by immunofluorescence method at PCH 24 too. The protein expressions of EphB2, Sox2, and N-cadherin in Schwann cells of two groups at PCH 24 were detected by Western blotting (n=20). (4) Totally 100 8-week-old male SD rats were selected, and an in situ replanted peritoneal denervated perforator flap was made in each rat. According to the random number table, the rats were divided into simple flap group, Fbs alone transplantation group, Schwann cells alone transplantation group, Schwann cells+ Fbs co-transplantation group, with 25 rats in each group. Flaps of rats in Fbs alone transplantation group and Schwann cells alone transplantation group were injected with 0.4 mL Fb and 0.4 mL Schwann cells respectively (2×10(6) cells each). Flaps of rats in Schwann cells+ Fbs co-transplantation group were injected with 0.4 mL Fbs and Schwann cells mixed cells (totally 2×10(6) cells, cell number ratio: 1∶1), and flaps of rats of simple flap group were injected with the same volume of DMEM high glucose medium. On post injection day (PID) 2, 5, 7, 9, and 14, 5 rats in each group were selected respectively according to the random number table. The flap tissue was collected, and the number, diameter, and arrangement of regenerated nerves were observed by immunofluorescence method. Data were processed with completely random designed t test, analysis of variance for repeated measurement, t test, and Bonferroni correction. Results: (1) The third passage of cells isolated and cultured from the rat embryo trunks were uniform in size and shape, long spindle-shaped, with a large proportion of nuclei. Strong positive expressions of fibronectin and Ephrin-B2 protein in cells were observed, and the mRNA expression of Ephrin-B2 was 0.004 1±0.000 8. The cells were identified as Fbs. (2) After 5 days of culture, the primary cells isolated from the sciatic nerves and brachial plexus nerves of neonatal rats were elongated in cell bodies and grew in nest, fence, or vortex-like shape. The third passage of cells were detected by immunofluorescence method and flow cytometer, and the corresponding S100 positive cell rates were (95.9±1.0)% and (95.8±1.1)% respectively. The cells were identified as Schwann cells. (3) At PCH 6 and 24, the cluster numbers of Schwann cells in Schwann cells+ Fbs co-culture group were significantly higher than those of Schwann cells alone culture group (t=6.500, 10.614, P<0.01). At PCH 24, the Schwann cells in Schwann cells+ Fbs co-culture group aggregated into clusters, Fbs dispersed around the Schwann cell clusters, and the protein expressions of EphB2, N-cadherin, and Sox2 in Schwann cells were significantly higher than those in Schwann cells alone culture group (t=2.975, 19.717, 11.159, P<0.05 or P<0.01). (4) On PID 2, a small number of scattered, disordered, short, and thin nerve fibers were observed in the flap tissue of rats in the four groups. From PID 5 to 14, the number of nerve fibers in the flap tissue of rats of Schwann cells+ Fbs co-transplantation group increased gradually, and the nerve fibers were with long diameter and arranged orderly. The number of nerve fibers in the flap tissue of rats of Schwann cells alone transplantation group increased, but the nerve fibers were with short diameter and arranged disorderly, and the number was smaller than that of Schwann cells+ Fbs co-transplantation group. In simple flap group and Fbs alone transplantation group, the nerve fibers in the flap tissue of rats gradually degenerated with gradually decreased number or even disappeared. Conclusions: The combined transplantation of Fbs and Schwann cells in rats can regulate Schwann cells migration and clustering by activating Ephrin/Eph-Sox2-N-cadherin signaling pathway, thus promoting the orderly nerve regeneration of denervated perforator flaps in rats.

[Effects of local transplantation of autologous adipose-derived mesenchymal stem cells on the formation of hyperplastic scar on rabbit ears].

Objective: To investigate the effects of local transplantation of autologous adipose-derived mesenchymal stem cells (ADSCs) on the formation of hyperplastic scar on rabbit ears. Methods: ADSCs were isolated from inguinal fat of six New Zealand rabbits and then sub-cultured. ADSCs of the third passage of each rabbit were used in the following experiments. Six full-thickness skin defect wounds with diameter of 6 mm on the ventral surface of every rabbit ear were made. Wound healing and local-tissue proliferation were observed, and complete epithelization time of wounds and formation time of hyperplastic scar were recorded. The wounds on left ears were selected as group ADSCs, and the wounds on right ears were selected as control group, with 36 wounds in each group. After the complete epithelization of wounds (post injury day 25), 0.2 mL bromodeoxyuridine (BrdU) labeled autologous ADSCs with the concentration of 5×106 per milliliter were injected into each wound of the rabbit of group ADSCs, while the same amount of phosphate buffer solution was injected into each wound of the rabbit of control group. The frequency of injection was once every 5 days, totally for 3 times, and the latter 2 times were injected into scars generated from healed wound. Hyperplastic scars of rabbits of two groups were harvested on the fifth day after the third injection, then the morphology was observed by HE staining, and the arrangement of collagen in hyperplastic scar was observed by VG staining. The distribution of BrdU-labeled ADSCs in the hyperplastic scar was observed with fluorescence microscope. The protein content of type Ⅰ collagen, type Ⅲ collagen, transforming growth factor ß1 (TGF-ß1), and decorin in hyperplastic scar were detected by enzyme-linked immunosorbent assay, and the mRNA expression of decorin and TGF-ß1 in hyperplastic scar were tested by real-time fluorescent quantitative reverse transcription-polymerase chain reaction. Data were processed with paired t test. Results: (1) The complete epithelization time of wounds of rabbits' ears was (20.0±2.0) d post injury, and hyperplastic scars were formed on post injury day 35.0±2.2. On post injury day 40, hyperplastic scars of rabbits of control group were still obvious, while those of group ADSCs became smaller, flat, soft, and light colored. (2) Compared with those in control group, epithelial cell layers and the number of nucleated cells in corium layer of hyperplastic scars of rabbits of group ADSCs were increased, and epithelium foot like and dermal papilla like structures were observed. The collagen density of hyperplastic scars of rabbits of control group was tight and arranged disorderly, while that of group ADSCs were decreased significantly and arranged regularly as compared with that of control group. (3) On post injury day 40, BrdU-labeled ADSCs were still observed in the hyperplastic scars of rabbits of group ADSCs. (4) The protein content of type Ⅰ collagen, type Ⅲ collagen, TGF-ß1, and decorin in hyperplastic scars of rabbits of group ADSCs were respectively (1.40±0.04) and (8.18±0.23) µg/L, (25.1±0.7) ng/L, and (4.872±0.101) ng/mL, and those in hyperplastic scars of rabbits of control group were respectively (2.29±0.05) and (12.20±0.38) µg/L, (37.2±1.1) ng/L, and (4.143±0.024) ng/mL. Compared with those in control group, the protein content of type Ⅰ collagen, type Ⅲ collagen, and TGF-ß1 in hyperplastic scars of rabbit of group ADSCs were significantly decreased (with t values from -33.66 to -22.84, P values below 0.001), while the protein content of decorin were significantly increased (t=10.41, P<0.001). (5) Compared with those in control group, the mRNA expression of TGF-ß1 in hyperplastic scars of rabbits of group ADSCs was significantly decreased (t=4.45, P<0.01), while the mRNA expression of decorin was significantly increased (t=5.61, P<0.01). Conclusions: Autologous transplantation of ADSCs into scar of rabbit at the early stage can inhibit the formation of hyperplastic scar, promote the quality of wound healing, and the mechanism may relate to the down-regulation of TGF-ß1, type Ⅰ collagen, and type Ⅲ collagen and the up-regulation of decorin induced by ADSCs.

[Effects of Huanglian ointment on wound healing of mice with full-thickness skin defect and the related mechanism].

Objective: To observe the effects of Huanglian ointment on wound healing of mice with full-thickness skin defect, and to explore the related mechanism. Methods: Thirty male C57BL/6J mice were divided into Huanglian ointment group and vehicle group according to the random number table after round wounds of full-thickness skin defect with diameter of 7.5 mm were inflicted on the back of each mouse, with 15 mice in each group. Wounds of mice in Huanglian ointment group and vehicle group were treated with Huanglian ointment and vehicle respectively from post injury day (PID) 1 on, 2 times each day. Five mice from each group were selected to observe wound changes on PID 0, 3, 7, 10, and 14, and wound healing rates were calculated. Five mice out of the 10 mice that hadn't been used for general observation in each group were sacrificed on PID 3 and 7 respectively, and 5 mice after being used for general observation in each group were sacrificed on PID 14. Wound and skin tissue within 2 mm from the edge of wound was collected. Histologic scoring was conducted based on the histomorphological observation with HE staining. The expression of double positive cells of alpha smooth muscle actin (α-SMA) and Ki-67 (myofibroblast) in tissue of wounds of mice was observed by immunofluorescence staining. Protein expressions of transforming growth factor beta (TGF-ß) and collagen in tissue of wounds of mice were determined by enzyme-linked immunosorbent assay. Data were processed with analysis of variance for repeated measurement, analysis of variance of factorial design, t test of two independent samples, one-way analysis of variance, and Bonferronni test or correction. Results: (1) Wounds of mice in two groups were red and swollen on PID 0, while they were neither red nor swollen with scabs on PID 3 and 7. On PID 10, woundsof mice in Huanglian ointment group contracted obviously, while the contracted wounds of mice in vehicle group were smaller than those in Huanglian ointment group. On PID 14, wounds of most mice in Huanglian ointment group were healed, while wounds of some mice in vehicle group failed to heal. Wound healing rates of mice in two groups were close on PID 3 and 7 (with t values respectively 0.64 and 1.90, P values above 0.05). Wound healing rates of mice in Huanglian ointment group on PID 10 and 14 were (76±7)% and (93±5)% respectively, significantly higher than those of vehicle group [(48±9)% and (68±11)%, with t values respectively 7.44 and 3.89, P values below 0.01]. Wound healing rates of mice in two groups on PID 7, 10, and 14 were significantly higher than those on the previous time points of the same group (with P values below 0.01). (2) Histologic scores of wounds of mice in two groups were close on PID 3 (t=-0.76, P>0.05). Histologic scores of wounds of mice in Huanglian ointment group on PID 7 and 14 were (7.0±1.6) and (11.6±2.1) points respectively, significantly higher than those of vehicle group [(4.2±1.3) and (7.2±1.3) points, with t values respectively 1.96 and 2.50, P<0.05 or P<0.01]. Histologic scores of wounds of mice in two groups on PID 7 and 14 were significantly higher than those on the previous time points of the same group (with P values below 0.01). (3) Percentages of double positive cells of α-SMA and Ki-67 in tissue of wounds of mice in Huanglian ointment group on PID 3 and 7 were (35±12)% and (62±10)% respectively, significantly higher than those of vehicle group [(17±12)% and (34±6)%, with t values respectively -2.48 and -5.25, P<0.05 or P<0.01]. The percentage of double positive cells of α-SMA and Ki-67 in tissue of wounds of mice in Huanglian ointment group on PID 14 was (25±5)%, significantly lower than that of vehicle group [(44±17)%, t=2.50, P<0.05]. The percentage of double positive cells of α-SMA and Ki-67 in tissue of wounds of mice on PID 7 was significantly higher than that on PID 3 or 14 in Huanglian ointment group (with P values below 0.01). Percentages of double positive cells of α-SMA and Ki-67 in tissue of wounds of mice on PID 7 and 14 were significantly higher than those on the previous time points in vehicle group (with P values below 0.05). (4) Protein expressions of TGF-ß in tissue of wounds of mice in Huanglian ointment group on PID 3 and 7 were (396±45) and (722±96) pg/mL respectively, significantly higher than those of vehicle group [(290±42) and (382±62) pg/mL, with t values respectively -8.17 and -6.65, P values below 0.01]. Protein expressions of TGF-ß in tissue of wounds of mice in two groups were close on PID 14 (t=1.60, P>0.05). The protein expression of TGF-ß in tissue of wounds of mice in Huanglian ointment group on PID 7 was significantly higher than that on PID 3 or 14 (with P values below 0.01). Protein expressions of TGF-ß in tissue of wounds of mice in vehicle group on PID 7 and 14 were significantly higher than those on the previous time points (with P values below 0.05). Protein expressions of collagen in tissue of wounds of mice in two groups were close on PID 3 (t=1.99, P>0.05). Protein expressions of collagen in tissue of wounds of mice in Huanglian ointment on PID 7 and 14 were (47±10) and (70±14) ng/mL respectively, significantly higher than those of vehicle group [(34±10) and (42±12) ng/mL, with t values respectively 3.15 and 3.52, P<0.05 or P<0.01]. Protein expressions of collagen in tissue of wounds of mice in two groups on PID 7 and 14 were significantly higher than those on the previous time points of the same group (P<0.05 or P<0.01). Conclusions: Huanglian ointment can promote wound healing of full-thickness skin defect of mice through increasing production of myofibroblasts and protein expressions of TGF-ß and collagen.

Effect of high-intensity exercise on interleukin-15 expression in rabbit synovia.

The objective of this study was to examine the effect of high-intensity exercise on interleukin-15 (IL-15) expression in rabbit synovia. We utilized 24 New Zealand white rabbits, which were randomly divided equally into high-intensity exercise and control groups. The former were forced to run for 60 min/day over 4 weeks at the speed of 30 m/min. The histological changes of cartilage and knee joint synovia were investigated with hematoxylin and eosin staining. Immunohistochemistry and enzyme-linked immunosorbent assays were performed to measure IL-15 expression. From these analyses, we identified knee articular cartilage damage and synovitis in the high-intensity exercise group. This group also exhibited higher IL-15 expression in their synovial fluid and tissues than was observed in the control group (P < 0.05). These results suggested that high-intensity exercise might lead to synovitis and articular cartilage damage, and that IL-15 overexpression in synovia might be associated with post-traumatic osteoarthritis.

Effects of high intensity exhaustive exercise on SOD, MDA, and NO levels in rats with knee osteoarthritis.

The aim of this study was to investigate the impact of high intensity exhaustive exercise on nitric oxide (NO), malondialdehyde (MDA), and superoxide dismutase (SOD) expression in rats with knee osteoarthritis. Sprague Dawley rats were randomly divided into control (N = 5) and model (N = 35) groups; the model group was further divided into quiet (N = 5), low- (N = 15) and high- (N = 15) intensity exhaustive exercise groups. The low- and high-intensity groups were randomly divided into pre-exercise (N = 5), immediate post-exercise (N = 5), and 24-h post-exercise (N = 5) groups according to different time points for detection. NO, MDA, and SOD levels were compared between each group. The SOD levels in the quiet, low-, and high-intensity exhaustive exercise groups were lower than that in the control group, whereas the NO and MDA levels were higher in the former groups than in the controls (P < 0.05). The SOD level in the 24-h post-low intensity exhaustive exercise group was higher than that in the 24-h post-high intensity exhaustive exercise group, whereas the NO and MDA levels were lower in the 24-h post-low intensity than in the post-high intensity exercise group (P < 0.05). Overall, the results demonstrated that with the increase of exercise intensity, the SOD activity in the rats with knee osteoarthritis decreased gradually, whereas the MDA and NO levels gradually increased. Thus, the greater the exercise intensity, the more serious the impact on knee osteoarthritis.

Protective effect and mechanism of probucol in the treatment of spinal cord injury.

To investigate the effects of probucol on the treatment of spinal cord injury in rat, 80 rats were randomly divided into two groups of 40: a group treated with probucol and a control group. Allen's method was used to establish a rat model of spinal cord injury. After establishment, probucol (500 mg·kg(-1)·day(-1)) was intraperitoneally injected into the treatment group rats for 1 week, while the same amount of saline was used to treat the control group. On days 1, 7, 14, 21, and 28 after treatment, the function of rats' spinal cord was evaluated according to the Bresnahan locomotor rating scale. Serum protein and mRNA levels of the cytokines [interferon (IFN)-γ, tumor necrosis factor (TNF)-α, and interleukin (IL)-17] were measured using enzyme-linked immunosorbent assay and quantitative polymerase chain reaction, respectively. Protein levels of IFN-γ, TNF-α, IL-17, and the downstream markers signal transducer and activator of transcription (STAT)-1 and STAT-3 were measured using western blot. In addition, the oxidative stress-related parameters, superoxide dismutase (SOD) and malondialdehyde (MDA), were also measured. It was found that compared to control group, rats from the treatment group had significantly lower levels of IFN-γ, TNF-α, and IL-17 (P < 0.05) on days 1 and 7, as well as lower MDA levels and higher SOD activity on days 7, 21, and 28 (P < 0.05). In summary, probucol improved the recovery of locomotion function after spinal cord injury in rats through downregulation of inflammation and upregulation of anti-oxidative activity.

Effects of tumour necrosis factor-alpha on activity and nitric oxide synthase of endothelial progenitor cells from peripheral blood.

The aim of this investigation was to determine whether tumour necrosis factor-alpha (TNF-α) has any effect on endothelial progenitor cells (EPCs). Total mononuclear cells were isolated from peripheral blood by Ficoll density gradient centrifugation, and then the cells were plated on fibronectin-coated culture dishes. After 7 days culture, attached cells were stimulated with tumour necrosis factor-α (final concentrations: 0, 10, 20, 50 and 100 mg/l) for 0, 6, 12, 24 and 48 h. EPCs were characterized as adherent cells double positive for DiLDL-uptake and lectin binding, by direct fluorescence staining. EPC proliferation and migration were assayed using the MTT assay and modified Boyden chamber assay, respectively. EPC adhesion assay was performed by re-plating those cells on fibronectin-coated dishes, and adherent cells were counted. Tube formation activity was assayed using a tube formation kit. Levels of apoptosis were revealed using an annexin V apoptosis detection kit. Vascular endothelial growth factor Receptor-1 (VEGF-R1) and stromal derived factor-1 (SDF-1) mRNA, assessed by real-time RT-PCR inducible nitric oxide synthase (iNOS) and endothelial nitric oxide synthase (eNOS) were assayed by western blot analysis. Incubation of EPCs with tumour necrosis factor-α reduced EPC proliferation, migration, adhesion, tube formation capacity, iNOS and eNOS in concentration- and time-dependent manners. Tumour necrosis factor-α reduced proliferation, migration, adhesion and tube formation capacity of EPCs. TNF-α increased EPC apoptosis level, reduced VEGF-R1 and SDF-1 mRNA expression; tumour necrosis factor-α also reduced iNOS and eNOS in the EPCs.

Electron standing waves on the GaN(0001)-pseudo (1 × 1) surface: a FT-STM study at room temperature.

We report the direct imaging of standing waves on a GaN(0001)-pseudo (1 × 1) metallic surface, which consists of two atomic Ga layers with the top layer incommensurate. Two types of periodic oscillation are observed by scanning tunneling microscopy at room temperature. The longer wavelength standing waves are due to electron scattering by dislocation-induced steps and two-dimensional InN islands. The localized shorter wavelength waves are attributed to a structural transition of the incommensurate Ga bilayer to a tetrahedral Ga bilayer after the growth of the InN islands.

Epitaxial graphene on SiC(0001): more than just honeycombs.

Using scanning tunneling microscopy with Fe-coated W tips and first-principles calculations, we show that the interface of epitaxial graphene/SiC(0001) is a warped graphene layer with hexagon-pentagon-heptagon (H(5,6,7)) defects that break the honeycomb symmetry, thereby inducing a gap and states below E(F near the K point. Although the next graphene layer assumes the perfect honeycomb lattice, its interaction with the warped layer modifies )the dispersion about the Dirac point. These results explain recent angle-resolved photoemission and carbon core-level shift data and solve the long-standing problem of the interfacial structure of epitaxial graphene on SiC(0001).

Atomic-scale imaging and manipulation of ridges on epitaxial graphene on 6H-SiC(0001).

Ridges are observed on epitaxial graphene on 6H-SiC(0001) by scanning tunneling microscopy (STM). Atomic resolution imaging reveals that they are in fact bulged regions of the graphene layer, occurring as a result of bending and buckling to relieve the compressive strain. Furthermore, their length, direction, and distribution can be manipulated, and new ones can even be created by the tip-surface interactions during STM imaging. The lower limit of terrace size for ridge formation is estimated to be approximately 80 nm, and nearly ridge-free graphene film can be obtained on vicinal 3.5 degrees miscut substrates.

Serum antioxidant vitamins and risk of lung and stomach cancers in Shenyang, China.

In a hospital-based case control study, we measured serum concentrations of vitamin A, beta-carotene and vitamin E for subjects with cancer (58 cases of lung cancer and 22 cases of stomach cancer) and 63 matched controls in Shenyang, China. Lung cancer patients had significantly (P < 0.01) lower mean serum levels of vitamin A, beta-carotene and vitamin E than controls, while the mean serum level of vitamin E did not differ between stomach cancer patients and the controls. Lower serum levels of vitamin A, vitamin E and beta-carotene were associated with an increased risk of lung cancer. Lower serum levels of vitamin A and beta-carotene were associated with a higher risk of stomach cancer, although the number of cases was small. An increased risk of lung cancer associated with lower serum levels of vitamin A and vitamin E was more evident among heavy smokers than among non-heavy smokers.

The correlation of Ureaplasma urealyticum infection with infertility.

A prevalence study of Ureaplasma urealyticum (UU) infection of the male genital tract was carried out in Shanghai between March 1992 and June 1995. Significantly higher frequency of UU infection was found among infertile males (549/1416) as compared to fertile controls (34/375). Examination of 8 specimens each from infertile men and fertile subjects by electron microscopy, immunogold and immunofluorescence techniques, demonstrated adhesion of Ureaplasma urealyticum to the membrane of spermatozoa and exfoliated germ cells. In addition, gold particles on Ureaplasma urealyticum were found to be adhered to the sperm surface in 4 of the 8 samples. Strong specific anti-UU fluorescence was detected in 6 of 8 samples, mainly on the midpieces and post-acrosomal regions of the spermatozoa. To further study the effects of Ureaplasma urealyticum on fertility, 47 male Sprague-Dawley (SD) rats were infected artificially with Ureaplasma urealyticum serotype 8 (T960). Morphological changes in the seminiferous tubules were observed 3-5 weeks after inoculation in the sacrificed animals. Dramatic impairment of spermatogenesis of both testes was found in 11 rats. Mating experiment confirmed infertility in 12 of 40 rats. Offsprings of the infected rats were significantly smaller than those of controls in terms of prenatal weights and birthweights.

Gene deficiency of glutathione S-transferase mu isoform associated with susceptibility to lung cancer in a Chinese population.

Increased lung cancer risk associated with genetic polymorphism of glutathione S-transferase (GST, EC 2.5.1.18) isozyme mu was examined in a Chinese population. A significantly higher proportion in lung cancer patients showed GST mu deficiency compared with control group (71.0% vs. 51.1%, P < 0.005). Although the susceptibility to lung cancer showing gene deletion for GST mu isoform in non-smoking group is not significantly different from that in smoking group, a great number of individuals with gene deletion was found among cancer patients who are less than 50 years old. The pathology of lung tumors related to that lack of class mu isoform which occurred most frequently in patients with small cell carcinomas. Thus, present data further support that sensitivity to chemical toxins and pulmonary carcinogens may be affected by GST mu isoform polymorphism.

Mercury dynamics in hair of rats exposed to methylmercury by synchrotron radiation X-ray fluorescence imaging.

Two-dimensional distribution of mercury (Hg) in hair samples of rats exposed to methylmercury (MeHg) was analyzed by synchrotron radiation X-ray fluorescence (SR-XRF) imaging. Experiments with endogenous- and exogenous-model for MeHg exposure revealed that the metal level was obviously higher in the hair cortex after the former exposure whereas a dominant site that Hg distributed after the latter exposure was the cuticle. The method also provided us the Hg profile along the hair length with a single hair obtained by the endogenous model. Thus application of SR-XRF analysis to hair sample would facilitate biological monitoring to not only distinct Hg exposure but also determine its dynamics with only the specimen.