Performance characterization of bacterial cellulose reinforced polyvinyl alcohol/ polyacrylamide composite hydrogels / 中国组织工程研究

BACKGROUND: With the extension of the application of polymer hydrogel materials, to develop polymer hydrogel materials with better performance has become a hotspot. OBJECTIVE: To compare the mechanical properties of polyvinyl alcohol/polyacrylamide (PVA/PAM) composite hydrogel before and after modification by bacterial cellulose (BC), thereby providing a theoretic basis for its application in wound dressing.METHODS: BC-reinforced PVA/PAM hydrogels with different PVA/PAM contents were prepared using repeated freezing-thaw method. The BC/PVA/PAM hydrogels were characterized by infrared spectrum (IR) analysis, mechanical property test and scanning electron microscopy (SEM) observation, and thermogravimetric analysis. RESULTS AND CONCLUSION: SEM and IR results showed the PVA and PAM were combined and attached onto the surface of BC, indicating a success in the preparation of BC/PVA/PAM hydrogels. Results from the thermogravimetric analysis showed that the thermal-stability of the BC/PVA/PAM hydrogels improved significantly. The mechanical test results demonstrated that the tensile strength of the PVA/PAM hydrogels was strongly enhanced, and the elongation at break was significantly lowered after being reinforced with BC. Furthermore, the content of PVA and PAM had an obvious effect on the mechanical properties of the composites. When the PAM content was 1.0%, the tensile strength and elongation at break of BC/PVA/PAM composites were at the highest level, which were 331.79 kPa and 105.33%, respectively; when the PVA content was 3.5%, the elongation at break of the BC/PVA/PAM composites was increased to the maximum (46.25%). Moreover, the results of this work reveal that the BC/PVA/PAM hydrogels exhibit some promising characteristics as artificial biomaterials. In general, the introduction of bacterial cellulose significantly improves the mechanical properties of the PVA/PAM hydrogels, and enhances the stability of the BC/PVA/PAM.

Performance characterization of bacterial cellulose reinforced polyvinyl alcohol/ polyacrylamide composite hydrogels / 中国组织工程研究

BACKGROUND: With the extension of the application of polymer hydrogel materials, to develop polymer hydrogel materials with better performance has become a hotspot. OBJECTIVE: To compare the mechanical properties of polyvinyl alcohol/polyacrylamide (PVA/PAM) composite hydrogel before and after modification by bacterial cellulose (BC), thereby providing a theoretic basis for its application in wound dressing.METHODS: BC-reinforced PVA/PAM hydrogels with different PVA/PAM contents were prepared using repeated freezing-thaw method. The BC/PVA/PAM hydrogels were characterized by infrared spectrum (IR) analysis, mechanical property test and scanning electron microscopy (SEM) observation, and thermogravimetric analysis. RESULTS AND CONCLUSION: SEM and IR results showed the PVA and PAM were combined and attached onto the surface of BC, indicating a success in the preparation of BC/PVA/PAM hydrogels. Results from the thermogravimetric analysis showed that the thermal-stability of the BC/PVA/PAM hydrogels improved significantly. The mechanical test results demonstrated that the tensile strength of the PVA/PAM hydrogels was strongly enhanced, and the elongation at break was significantly lowered after being reinforced with BC. Furthermore, the content of PVA and PAM had an obvious effect on the mechanical properties of the composites. When the PAM content was 1.0%, the tensile strength and elongation at break of BC/PVA/PAM composites were at the highest level, which were 331.79 kPa and 105.33%, respectively; when the PVA content was 3.5%, the elongation at break of the BC/PVA/PAM composites was increased to the maximum (46.25%). Moreover, the results of this work reveal that the BC/PVA/PAM hydrogels exhibit some promising characteristics as artificial biomaterials. In general, the introduction of bacterial cellulose significantly improves the mechanical properties of the PVA/PAM hydrogels, and enhances the stability of the BC/PVA/PAM.

Parkin promotes proteasomal degradation of p62: implication of selective vulnerability of neuronal cells in the pathogenesis of Parkinson's disease

Mutations or inactivation of parkin, an E3 ubiquitin ligase, are associated with familial form or sporadic Parkinson's disease (PD), respectively, which manifested with the selective vulnerability of neuronal cells in substantia nigra (SN) and striatum (STR) regions. However, the underlying molecular mechanism linking parkin with the etiology of PD remains elusive. Here we report that p62, a critical regulator for protein quality control, inclusion body formation, selective autophagy and diverse signaling pathways, is a new substrate of parkin. P62 levels were increased in the SN and STR regions, but not in other brain regions in parkin knockout mice. Parkin directly interacts with and ubiquitinates p62 at the K13 to promote proteasomal degradation of p62 even in the absence of ATG5. Pathogenic mutations, knockdown of parkin or mutation of p62 at K13 prevented the degradation of p62. We further showed that parkin deficiency mice have pronounced loss of tyrosine hydroxylase positive neurons and have worse performance in motor test when treated with 6-hydroxydopamine hydrochloride in aged mice. These results suggest that, in addition to their critical role in regulating autophagy, p62 are subjected to parkin mediated proteasomal degradation and implicate that the dysregulation of parkin/p62 axis may involve in the selective vulnerability of neuronal cells during the onset of PD pathogenesis.

Serum levels of carcino-embryonic antigen and CA15-3 in patients with early stage breast cancer ;before surgery and their correlation with pathological features / 肿瘤研究与临床

Objective To detect and analyze the levels of preoperative serum carcino-embryonic antigen (CEA) and CA15-3 in early invasive breast cancer patients and their correlation with pathological parameters. Methods Electrochemical luminescence immunoassay (ECLI) technology was used to detect serum levels of CEA and CA15-3 in 223 cases of early invasive breast cancer patients, 109 patients with benign lesions, and 30 cases of heath control. Immunohistochemical (IHC) and fluorescence in situ hybridization (FISH) were used to detect the estrogen receptors (ER), progesterone recepter (PR), and its HER-2 pathological indicators.Besides, the correlation of serum CA15-3, CEA levels and pathological parameters was analyzed. Results The serum CA15-3 and CEA levels of Breast cancer patients [(22.27±15.11) U/ml, (5.03± 0.49) μg/L] were significantly higher than that of patients in benign lesion group [(14.13±3.04) U/ml, (2.72± 0.11) μg/L] (P0.05). CEA positive rate of breast cancer group was significantly higher than that of benign lesions(13.5%vs. 3.7%, 26.5%vs. 1.8%, P<0.05). 30 cases of normal control group had no positive one. The joint monitoring sensitivity of CEA and CA15-3 breast cancer group was 9.4 %, the sensitivity was 0 in benign lesion group. There was significant difference (P < 0.05). Conclusion The changes of Serum CA15-3 and CEA levels in breast cancer patients can be considered as the judgment standard for early diagnosis, pathological staging, prognosis and clinical effect monitoring.

Effects of electroacupuncture on the expression of related protein mRNA in the striatum in rats with Parkinson's disease / 中国针灸

<p><b>OBJECTIVE</b>To explore action mechanism of electroacupuncture (EA) on treatment of Parkinson's disease (PD).</p><p><b>METHODS</b>A total of 40 healthy male SD rats were randomly divided into a normal group, a sham operation group, a model group and an EA group, 10 rats in each group. PD rat model was duplicated by micro injection of 6-hydroxyl dopamine into right striatum of rats, and the rats in the sham operation group were treated with micro injection of 0. 9% NaCl. Rats in the normal group, model group and the sham operation group received no treatment; rats in the EA group were treated by EA at "Fengfu" (GV 16) and "Taichong" (LR 3) with continuous wave, 2 Hz in frequency, 1 mA in intensity for 30 min. The treatment was given once a day for total 2 weeks. Behavioral test was used to evaluate rotational behavior changes of PD rats. RT-PCR method was applied to detect the expression of GFAP (glial fiber acidic protein) mRNA and Cx43 (connexin 43) mRNA in the striatum.</p><p><b>RESULTS</b>The difference of rotational behavior was not significant before and after treatment in the model group (P>0. 05), while that in the EA group was significant (P<0. 01). The expression of GFAP mRNA and Cx43 mRNA in the model group was significantly higher than that in the normal group and sham operation group (all P<0. 01); after EA treatment, the expression of GFAP mRNA and Cx43 mRNA in the EA group was lower significantly than that in the model group (both P<0. 01).</p><p><b>CONCLUSION</b>The action mechanism of EA for prevention and treatment of Parkinson' s disease may be associated with inhibiting the activation of astrocytes.</p>

Influence of Electroacupuncture on Glu Concentration, GS and PAG Protein Levels in Striatum of Parkinson’s Disease Rats / 世界科学技术-中医药现代化

This study was aimed to explore the mechanism of electroacupuncture (EA) on improvement of Parkinson’s disease (PD). A total of 40 SD male rats were randomly divided into 4 groups, which were the normal group, sham-operation group, model group, and EA group (n=10). The 6-hydroxydopamine (6-OHDA) was used to prepare PD rat rotational model. The 0.2% Vitamin C of physiological saline was injected in the sham-operation group. EA on GV16-Fengfuand LR3-Taichongwas given for 30 min in the EA group after the model was successfully established, once a day, 7 days a treatment course. The treatment was given for 2 courses. Behavioral test was used to detect PD rat rotational behavior changes. Glu concentration in the striatum was detected by HPLC assay. The expression levels of GS and PAG were detected with western blot. The results showed that there were significant differences in the rotational behavior before and after treatment in the EA group (P < 0.01). Compared with the normal group and sham-operation group, Glu concentration significantly increased, GS expression obviously decreased, and PAG expression significantly increased in the model group (P < 0.01). Compared with the model group, Glu concentration obviously decreased (P < 0.05), GS expression significantly increased, and PAG significantly decreased in the EA group (P < 0.01). It was concluded that the protective effect of EA in PD may be associated with EA improving the expression of GS, reducing the expression of PAG, and relieving the cytotoxicity induced by Glu in the brain.

Clinical and molecular genetic studies of a Chinese family with oculopharyngeal muscular dystrophy / 中国神经精神疾病杂志

Objective To investigate the clinical and molecular genetic changes in a Chinese family with oculopha?ryngeal muscular dystrophy(OPMD). Methods We collected the clinical data of the familial members and blood sam?ples from all available 16 familial members, including the proband. The samples were analyzed using modified poly?merase chain reaction amplification and direct sequence analysis. Results Male OPMD patients initially presented with ptosis, followed by pronunciation difficulty, dysphagia and limb weakness whereas female OPMD patients initially pre?sented with swallowing difficulty. Genetic test revealed the abnormal expansions of the GCG trinucleotide repeat from GCG6 to GCG10 in PABPN1 gene in 10 familial members. Conclusions The genetic test and prenatal diagnosis is the key for the prevention treatment of oculopharyngeal muscular dystrophy. The ptosis of eyelid may be the initial symptom for the male patients of oculopharyngeal muscular dystrophy with (GCG)10 mutation.

Clinical research on diagnosis of traumatic rib fractures by multislice CT VRT and DR plain film / 中国医学装备

Objective:To research the value of diagnosis of traumatic rib fractures by multislice CT VRT and DR plain film. Methods: Seventy-two cases of traumatic rib fracture patients were diagnosed by DR film and multislice CT VRT. Results:Multiple rib fractures than single, most of them occurred in the 4-10 ribs and axillary segment, 97.2%of 16-slice spiral CT three-dimensional reconstruction of patients with rib fracture diagnosis rate significantly higher than DR plain film diagnosis rate 80.3%(x2=19.15, P<0.01), DR plain film missed rib fractures are mainly located in the costal cartilage (58.1%), 16-slice spiral CT reconstruction is still found 19 other fractures and lung complications 16cases. Conclusion:16-slice CT the thin layer VRT diagnosis of rib fractures greatly improves the diagnostic accuracy.

Isolation and in vitro propagation of aldehyde dehydrogenases positive breast cancer stem cells and investigation on biological property of these cells / 肿瘤研究与临床

Objective To identify a aldehyde dehydrogenases positive (ALDH+) cancer stem cell subpopulation in MCF-7 cells and to investigate the proliferation and differentiation characteristics of these cells in vitro.Methods ALDH+ breast cancer stem cells were isolated from MCF-7 cells by flow cytometry and the biological property of ALDH+ breast cancer stem cells were examined by scarification test,MTT,growth curvature and Transwell migration assay.Results The ratio of CD-/low24 CD+44 cells was about 1.4 ％ in MCF-7 cells.The ratio of ALDH+ CD-/low24CD+44 cells was about 1.2 ％.The growth curvature of ALDH+ breast cancer stem cells was almost the same with that of CD-/low24 CD+44 cells.The distance between cells was obviously shorter in both CD-/low24 CD+44 cells scarification zone and ALDH+ CD-/low24 CD+44 cells scarification zone.The migration ability of CD-/low24CD+44 cells and ALDH+ CD-/low24CD+44 cells was stronger than control group cells.There were migration ability differences between CD-/low24CD+44 cells and ALDH+ CD-/low24CD+44 cells.The results of Transwell experiments were in coincidence with above results.Lots of CD-/low24CD+44 cells and ALDH+ CD-/low24CD+44 cells were through the membrane.In MTT assay,absorbance values were 1.05±0.098,1.56±0.075 and 1.67±0.032.Conclusion CD--/low24CD+44 and ALDH+ CD-/low24CD+44 breast cancer stem cell subpopulation exist in MCF-7 cells.ALDH could potentially be used as a molecular marker to identify breast cancer stem cell subpopulation.

Advance in immunology and immune evasion of PRRSV / 病毒学报

Porcine reproductive and respiratory syndrome virus (PRRSV) continues to be a threat, causing economically significant impacts on the swine industry worldwide. Unfortunately, the traditional control strategies and conventional vaccines fail to provide sustainable disease control, in particular against genetically diverse strains, as they suffer from both antigenic heterogeneity and various immune evasion strategies of PRRSV. In this paper, latest research progress in immunology and immune evasion of PRRSVis summarized to provide a referenc for PRSSV prevention and control as well as the design of new vaccines.

Clinical study of the axillary conservative surgery by sentinel lymph node biopsy using preoperative lymphoscintigraph technique with 99mTc-SC and methylene blue in breast cancer surgical therapy / 中国医师进修杂志

Objective To evaluate the clinical significance of the axillary conservative surgery by sentinel lymph node biopsy (SLNB) using preoperative lymphoscintigraph technique with 99mTc-SC and methylene blue in early-stage breast cancer patients. Methods The sentinel lymph node (SLN) of 187 patients were located with preoperative lymphoscintigraph technique with 99mTc-SC and labeled with methylene blue during the operations. The metastasis of SLN was detected using frozen section technique. There were 51 patients whose SLN were positive having been carried with modified radical mastectomy of breast cancer and axillary lymph node dissection (ALND), 136 patients' SLN were negative,58 patients of those were carried with mammectomy or partial mastcctomy and ALND (group A),while 78 patients were carried out with mammectomy or partial mastectomy only (group B). The sentinel lymph nodes were detected with HE stain after surgery. All the patients were treated with chemotherapy,and the patients with partial mastcctomy must be treated with radiotherapy. There were 2 patients with micrometastasis in group B being treated with mammectomy or partial mastcctomy only,and carried out with ALND again. Results The number of cases with upper limb numbness, edema, dysfunction in group A were 36,8 and 45 cases, in group B were 2,0,0 case respectively. Group A compared with group B was increased significantly (P 0.05). Conclusion It is simple and accurate to carry out SLNB using preoperative lymphoscintigraph technique with 99mTc-SC combined with methylene blue,and the effect is reliable.

Long-term and acute toxicity of kallikrein from the venom of Agkistrodon hlays Pallas / 南方医科大学学报

A novel serine protease with high purity was extracted from the venom of Agkistrodon hlays Pallas using monoclonal antibody affinity chromatography. This protease releases bradykinin and has arginine esterase activity without being activated. After purification, its hydrolytic activity exceeded 800 U/mg, far higher than its counterparts from mammalian sources. The purity of the kininogenase could exceed 95%. The acute toxicity and the long-term toxicity of this kallikrein was studied for its potential clinical application. The maximum tolerance dose in adult was 150,000 times greater than the maximum applied dose, and long-term administration at the dose 50 times of allowed clinical dose did not obviously after the animals' body weight, survival condition, liver function, renal function, or blood routines, suggesting the extremely low toxicity of the kallidrein.

Oophorectomy combined with exemestane treating advanced refractory breast cancer / 中国癌症杂志

Background and purpose:Tamoxifen is the main endocrine therapy of premenopausal breast cancer with positive hormone receptors but numerous patients have developed advanced refractory breast cancer due to drug resistance.Our study investigated the role of combining oophorectomy and exemestane in the treatment of advanced refractory breast cancer.Methods:Oophorectomy was carried out in all patients.Exemestane was administered orally (25 mg/d) one week after the operation.The median time of progression (TTP),the median survival time as well as the survival rate were calculated using the Kaplan-Meier methods.Results:Seventeen patients ranging between the ages of 26 and 44 years (median:36 years) were treated resulting in an overall response rate of 64.70%,TTP was 8 months and the median survival time was 31 months.The survival rates for 1 year,3 years and 5 years were 88.24%,64.71%,29.41%,respectively.No grade Ⅲ and Ⅳ side effects appeared.Conclusion:Oophorectomy when combined with exemestane showed antitumor activity for advanced refractory premenopausal breast cancer through positive hormone receptor and it is also well-tolerated.