The attempt of vitrectomy is to remove the lesion of vitreous body and relieve vitreous traction to retina.Whether the vitrectomy is successful or not depend on if exist a close adhesion between vitreous body and retina or a posterior vitreous detachment (PVD).The drug assisted vitrectomy is a new technique.These drugs can help surgeon to form PVD during surgery safely and effectively.The drug is utilized prior to vitreoretinal operation to promote the colliquate of vitreous body or dissolve of fibroplasia membrane of the vitreous body in order to release the traction between the posterior cortex of vitreous body and the inner limiting membrane of retina.The research advance in relevant drugs is reviewed in this article.

Objective To observe the effects of low frequency electromagnetic fields (LFEMFs) on the proliferation of human epidermal stem cells (hESCs) cultured in a three dimensional environment so as to provide an experimental basis for applying LFEMF in skin tissue engineering.Methods hESCs from human prepuces were isolated and purified by the method of rapid adherence to collagen type ⅣV. They were grafted into a type-I collagen sponge or chitosan scaffold in vitro, and then stimulated with different frequencies of LFEMF ( 1 Hz, 10 Hz or 50 Hz) at a magnetic field intensity of 5 mT for 30 min/d. The cells' growth and proliferation were tracked using hematoxylin and eosin (HE) and diamine pheny1 indole (DAPI) staining and observed under the scanning electron microscope at different time points ( on 2nd, 7th, 10th and 14th days of LFEMF intervention). The amounts of cell proliferation at every time point were analyzed and compared.Results LFEMFs of different frequencies showed significantly different efficacy in promoting hESC proliferation. The two scaffolds also showed significantly different effects.By the 10th day, hESCs had grown significantly better on collagen sponge scaffolds than on the chitosan ones. All LFEMF frequencies could promote proliferation of hESCs, but the differences in their effects were statistically significant.Conclusion Collagen sponge may be a preferable scaffold for hESCs cultured in vitro. Rapid proliferation of ESCs in three-dimensional settings can be promoted by LFEMF intervention. LFEMF has relatively great potential in skin tissue engineering.

BACKGROUND:Bone marrow mesenchymal stem cel transplantation is considered as a promising therapy for spinal cord injury. How to more effectively promote the survival of bone marrow mesenchymal stem cel s in the area of spinal cord injury and to accelerate the recovery of motor function after spinal cord injury is a current study focus. Previous studies have found that low-frequency electromagnetic fields can promote bone marrow mesenchymal stem cel proliferation and differentiation, but whether the low-frequency electromagnetic fields can be applied to bone marrow mesenchymal stem cel transplantation for treatment of spinal cord injury requires further studies. OBJECTIVE:To discuss the effects of low-frequency electromagnetic fields on motor function of spinal cord injury rats after transplantation of bone mesenchymal stem cel s. METHODS:Sixty-four rat models of incomplete spinal cord injury at T 10 were established by compression method and then randomized into control group, transplantation group (bone mesenchymal stem cel transplantation), electromagnetic field group and combination group (electromagnetic field+bone mesenchymal stem cel transplantation). After successful modeling, bone mesenchymal stem cel s labeled with 5-bromo-2'-deoxyuridine were injected into the original injured site in the transplantation group and combination group, which were isolated and purified with the fast adherence method;while alpha-minimum essential medium was injected into the electromagnetic field group and control group for instead. At 24 hours post-operation, the electromagnetic field group and combination group were explored to low-frequency electromagnetic fields (frequency 50 Hz, magnetic indaction intensity 5 mT) for 60 minutes per day. RESULTS AND CONCLUSION:After cel transplantation for 21 days, the Basso, Beattie, and Bresnahan scores in the combination group was higher than the other groups (P<0.05). 5-Bromo-2'-deoxyuridine positive cel s grew wel , and integrated into the normal spine;syringomyelia was reduced, and the number of spinal neural cel s was increased in the combination group. In addition, glial fibril ary acidic protein expression was decreased in the combination group, while matrix metal oproteinase 2 expression was increased. It indicates that low-frequency electromagnetic fields could promote recovery of motor function in the spinal cord injury rats transplanted with bone mesenchymal stem cel s, which could be associated that low-frequency electromagnetic fields facilitate the survival of transplanted bone mesenchymal stem cel s, up-regulate the expression of matrix metal oproteinase 2, and reduce glial scar formation in the spinal cord injured site.

Objective To observe the effects of low intensity electromagnetic fields (LIEMFs) in promoting the reconstruction of full skin loss wounds grafted with human epidermal stem cells (ESCs). Methods Fifty nude mice aged 7 to 8 weeks with full skin loss wounds were equally divided into 3 experimental subgroups ( 1 Hz, 10Hz and 50Hz) and two control groups (a cell suspension control group and a blank control group) , with ten mice each. In the 3 experimental subgroups and the cell suspension control group, ESCs separated from human foreskin and cultured in vitro were grafted to the wounds using collagen sponge scaffolds. The experimental subgroups were then stimulated with an LIEMF (magnetic field intensity 5mT) at the appropriate frequency for 30min/day for 15 days. The blank control group was put under the same conditions without the cell suspension and LIEMF. The healing rates of the wounds were observed, and tissue slices were stained and observed under a light microscope. The inner structure of the regenerating skin was observed using transmission electron microscopy. Results The ESCs were successfully grafted. A few human integrin β1 positive stained cells appeared in the regenerating skin. The average healing rates in the experimental subgroups were significantly superior to those of the control groups. Well differentiated epidermis and dermis could be seen in the regenerating skin in all of the experimental groups. The epidermis had more cell layers and was thicker than in the control groups. More desmosome, hemidesmosome and keratin filaments were seen among the epidemic cells of the experimental groups. Conclusions LIEMF promotes the healing of full skin loss wounds grafted with ESCs in nude mice, and can promote complete repair of skin defects and the regeneration of skin function.

Objective:To analyze risk factors of cancer patients with Pseudomonas aeruginosa bloodstream infections and drug resistance. Methods:Clinical data of 30 cancer patients with P. aeruginosa bloodstream infection and 90 without infection who were ad-mitted in the Tianjin Medical University Cancer Institute and Hospital between January 2010 and December 2012 were retrospectively analyzed. Whonet 5.6 and SPSS19.0 software were used for statistical analysis of the data. Results:The infection group consisted of 20 male and 10 female patients with a mean age of 60.9±11.2 years. The control group consisted of 60 males and 30 females with a mean age of 51.3 ± 15.9 years. Multivariate logistic regression analysis showed that the number of hospitalization, combined with infection of other sites, and more than two types of antibiotics were independent risk factors of cancer patients with P. aeruginosa bloodstream infec-tions. P. aeruginosa showed high sensitivity(>80%) to carbapenems, ceftazidime, cefepime, aminoglycosides, and fluoroquinolones. The mortality rate of cancer patients with P. aeruginosa bloodstream infections was 60%. Conclusion:Cancer patients with P. aerugino-sa bloodstream infections have high mortality. Therefore, comprehensive prevention and control measures must be implemented in clini-cal practice to reduce P. aeruginosa bloodstream infections.

Objective To determine the value of differential time to positivity ( DTTP ) of blood culture for the diagnosis of catheter-related bloodstream infection ( CRBSI ) in patients with solid tumors in intensive care unit ( ICU ). Methods A retrospective study was conducted. 615 pairs of peripheral vein blood cultures and instantaneous catheter tip blood culture of 615 patients admitted to ICU of Tianjin Medical University Cancer Institute and Hospital were collected from August 2011 to March 2014. The DTTP method and ( or ) semi quantitative culture of catheter tip were compared. CRBSI was diagnosed when both cultures were positive for the same microorganism and DTTP ≥2 hours ( 120 minutes ). The result of this procedure was compared with that of organism obtained using the semi quantitative culture of blood at catheter tip with≥15 cfu. Based on the clinical diagnosis, the reliability of two kinds of laboratory examination was compared for the diagnosis of CRBSI by plotting receiver operator characteristic curve ( ROC curve ). Results The result of 615 cases suspected of having CRBSI were analyzed during the study period. Of these, 440 episodes were excluded because cultures were negative for blood obtained through peripheral vein and central vein. Eight episodes were excluded because only peripheral vein blood culture was positive and 57 episodes were excluded because of only central vein blood culture was positive, 68 pairs of blood cultures were excluded due to the presence of multiple catheters and repeated blood withdrawals. Two cases of polymicrobial cultures were excluded from the final analysis due to the difficulty in determining the time of positive result for each individual microorganism. Ten cases in 42 cases of suspected cases of CRBSI were excluded from analysis because catheter was not removed, therefore culture from catheter tip could not be obtained. Using the DTTP method, 14 out of 17 CRBSI cases were diagnosed with DTTP≥120 minutes, while 3 cases were missed;the semi quantitative catheter tip culture was positive in 13 cases, and in 4 cases it was neglected. In 2 cases of CRBSI it was missed by both methods. The area under the ROC curve ( AUC ) of DTTP, catheter tip culture and the combination method was 0.912, 0.882 and 0.941 for diagnosis of CRBSI, respectively. Validity values for the diagnosis of CRBSI for DTTP were:sensitivity 82.35%, specificity 92.31%, positive predictive value 93.33%and negative predictive value 80.00%, and they were higher than those of the catheter tip culture method only ( 76.47%, 84.62%, 86.67% and 73.33%). The specificity and positive predictive CRBSI combination of the two methods in the diagnosis value were up to 100%, the sensitivity ( 88.24%) and negative predictive value ( 86.67%) was also increased, but no significant differences were found with DTTP method (χ2=0.00, P=1.00;χ2=0.00, P=0.98;χ2=0.00, P=0.98;χ2=0.00, P=0.98 ). Conclusions DTTP can be a valid method recommended for CRBSI diagnosis in critically ill patients with acceptable sensitivity, good specificity as well as positive predictive value. DTTP combined with other clinical symptoms can not only avoid unnecessary catheter withdrawal, but it also can help obtain the optimal treatment time and strategy.

BACKGROUND:The repair and management of ful-thickness skin defects resulting from burns and chronic wounds remain a significant unmet clinical chal enge. Using epidermal stem cel s and keratinocyte growth factor for ful-thickness wound repair is a promising approach. Low-frequency electromagnetic fields which are a non-invasive physical stimulation therapy have been recognized as a good method to enhance wound healing. OBJECTIVE:To develop a new strategy to accelerate wound healing by transplanting transfected epidermal stem cel s and keratinocyte growth factor and treating with low-frequency electromagnetic fields in a mouse model. METHODS:Epidermal stem cel s from Sprague-Dawley neonatal rats were isolated and cultured in vitro, then the cel s were labeled with 5-bromo-2-deoxyuridine and transfected by Ad-KGF, a recombinant adenovirus carrying the keratinocyte growth factor. Mice were given to create ful thickness skin wound on the dorsum and randomly assigned to four groups:control group, transplantation of epidermal stem cel s group, transplantation of keratinocyte growth factor gene modified epidermal stem cel s group, and transplantation of keratinocyte growth factor gene modified epidermal stem cel s plus low-frequency electromagnetic field exposure group. RESULTS AND CONCLUSION:The best healing pattern was observed in the keratinocyte growth factor gene modified epidermal stem cel s plus low-frequency electromagnetic field exposure group (P<0.05) at days 9 and 16. 5-Bromo-2-deoxyuridine labeled cel s existed in the wound in the treated groups at day 9. A significantly increased expression of endogenous keratinocyte growth factor was detected in the transplantation of Keratinocyte Growth Factor gene modified epidermal stem cel s group, and transplantation of keratinocyte growth factor gene modified epidermal stem cel s plus low-frequency electromagnetic field exposure group at day 16. A wel-advanced epithelialization was observed in transplantation of keratinocyte growth factor gene modified epidermal stem cel s plus low-frequency electromagnetic field exposure group at days 16 and 30. These results suggest that low-frequency electromagnetic fields enhanced wound healing fol owing the transplantation of keratinocyte growth factor gene modified epidermal stem cel s.

Objective:To evaluate the predictors for the mortality of patients with malignant tumor and invasive candidiasis in order to contribute to the strategies of prognosis improvement. Methods:This retrospective study includes patients with malignant tumor and invasive candidiasis who were hospitalized during 2013 to 2015. Their clinical characteristics, medication treatment, types of tumor, and mortality rate were collected and analyzed. Categorical data were analyzed by the Fisher's exact test. Factors with a P value<0.05 were included in the multivariate Logistic regression model to determine the independent risk factors. Results:A total of 125 patients with malignant tumor with invasive candidiasis were included. The major pathogen was still Candida albicans, which caused 42.4％of the infections, followed by Candida glabrate (21.6％), Candida parapsilosis (16.8％), and Candida tropicalis (10.4％). Abdominal candidia-sis (51.2％) was the most common type of infection. The crude mortality rate for invasive candidiasis was 26.4％. Azotemia, more than two indwelling catheters, delayed antifungal treatment, and combination with bacterial infections were the independent risk factors for the death of patients with malignant tumor and invasive candidiasis as compared with the survival group. Surgery within 30 days before diagnosing candidiasis was confirmed to be a protective factor for prognosis. Conclusion:Invasive candidiasis among patients with malignant tumor induced a high mortality rate. The data on the predictors for death may be valuable in developing strategies for prognosis improvement.

This study sought to construct a recombinant vector that expresses anti-GD2/anti-CD16 bispecific single-chain antibody(sc-BsAb), and to assess its biological activities. The anti-GD2 gene and the anti-CD16 gene (NM3E2) were obtained using PCR amplification technique, and then the fusion gene was constructed by overlapping PCR. The sc-BsAb gene was subcloned into the pET-22b(+) plasmid from the pMD18-T easy vector by digestion with NcoI, Hind III restriction endonucleases, whose sites exist in both the vectors. Then the combinant plasmids were transferred into E. coli BL21 (DE3). The expression product in the periplasmic was analyzed by both SDS-PAGE and Western blot technique, then was purified with Ni2+ -NTA superflow affinity chromatography. It was demonstrated that the linker in the sc-BsAb fusion protein is SerGly4Ser. and the molecular is 53 KD.
Antibodies, Bispecific ; biosynthesis ; genetics ; Antibodies, Neoplasm ; biosynthesis ; genetics ; Base Sequence ; Cell Line, Tumor ; Cloning, Molecular ; Escherichia coli ; genetics ; metabolism ; Gangliosides ; immunology ; HeLa Cells ; Humans ; Melanoma ; pathology ; Molecular Sequence Data ; Receptors, IgG ; immunology ; Recombinant Fusion Proteins ; biosynthesis ; genetics

Objective: To investigate the correlations of indexes of isokinetic muscle testing with grip, the circumference of muscle, the time up and go test(TUGT), and the distance of 6-minutes walk test(6MWT). And to identify the availability of isokinetic muscle testing in diagnosing sarcopenia in the elderly. Methods: A total of 27 elderly patients with sarcopenia admitted in rehabilitation department of our hospital from Jan.2017 to Dec.2017 were enrolled in this cross-sectional study.Patients were evaluated in many aspects, including comprehensive evaluation by the comprehensive assessment, the skeletal muscle mass detection by dual energy X-Ray absorptiometry, the power of gripping by dynamometer, the circumference of muscle of upper and lower extremities, the muscle strength by isokinetic muscle testing, the sports ability by TUGT and 6MWT. Results: Isokinetic muscle testing including the knee flexion, knee extension, elbow extension, wrist extension, TUGT, 6MWT, the power of left gripping, the circumference of left forearm muscle showed a negative correlations to the age(r=-0.54, -0.44, -0.52, -0.61, -0.53, -0.41 and-0.39, P<0.05). A positive correlation were observed between TUGT and the age(r=0.44, P<0.05). The positive correlations between every index in isokinetic muscles testing and the power of both left and right gripping were observed(r=0.66, 0.67, 0.67, 0.67, 0.56, 0.62, 0.54, 0.54, 0.64, 0.59, 0.59 and 0.56, P<0.05). The knee flexion, knee extension, elbow flexion, elbow extension and wrist extension of Isokinetic muscle testing showed a positive correlations to 6MWT(r=0.71, 0.65, 0.62, 0.60 and 0.59, P<0.05). The knee flexion, knee extension, elbow extension and wrist extension of isokinetic muscle testing showed a negative correlations to TUGT(r=-0.57, -0.52, -0.42 and-0.48, P<0.05). Every index of isokinetic muscle testing showed a positive correlations to the circumference of both forearms(r=0.45, 0.47, 0.52, 0.42, 0.41, 0.44, 0.49, 0.52、0.60, 0.54, 0.44 and 049, P<0.05). Conclusions Isokinetic muscle testing can accurately evaluate the changes of muscle strength in the elderly with sarcopenia.It can be considered as the reference index of motor function in diagnosing sarcopenia in the elderly.