BACKGROUND: Recently biodegradable hydrogel has been extensively used to delivery anticancer drug and bioactive macromolecule. However, to protect the activity of the bioactive macromolecule, we need to obtain series of hydrogel which have milder hydrogelation conditions and shorter hydroglation time.OBJECTIVE: To prepare enantiomeric poly(L-Lactic acid) (PLLA)-poly(ethylene glycol (PEG)-PLLA/ poly(D-Lactic acid) (PDLA)-PEG-PDLA stereocomplex hydrogel which has shorter hydroglation time, to physically encapsulate a model drug-lysozyme and sustained release it from the hydrogel. METHODS: Triblock copolymers of PLLA-PEG-PLLA and PDLA-PEG-PDLA were synthesized by ring-opening polymerization of L(D)-lactide using PEG as the initiator and Sn(Oct)2 as the catalyst. The triblock copolymers were characterized by 1H nuclear magnetic resonance, FT-IR and X-Ray diffractometry. A hydrogel was prepared from an aqueous mixture of PLLA20-PEG227-PLLA20 and PDLA21-PEG227-PDLA21 (10 wt% concentration) at room temperature for 12 hours. X-Ray diffractometry test was used to research the gelation mechanism. The release profile of the lysozyme as a model drug from the hydrogel was tested. The morphology of the freeze-dried hydrogel was investigated by scanning electron microscope. The cytotoxicity of the hydrogel was evaluated by 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyl tetrazolium bromide) assay.RESULTS AND CONCLUSION: Triblock copolymers of PLLA-PEG-PLLA and PDLA-PEG-PDLA were obtained. Both the PEG and PLA blocks in the copolymers could crystallize, but the crystallization of the PEG block was predominant. The stereocomplex formation between the PLLA and PDLA blocks within the hydrogel was confirmed by the X-Ray diffractometry analysis. The release profile of the lysozyme from the hydrogel exhibited a sustained-release pattern with a duration period of 7 days. The hydrogel exhibited a 3D interconnected porous structure with 50-100 μm pore size after being freeze-dried. The mouse fibroblast cell viability percentage was 99.3% after the cells contacted with the 100% extracted liquid for 72 hours.

Sef (similar expression to fgf genes) was identified as a feedback antagonist of FGF signaling in zerbrafish, mouse and human. Sefhas been reported to function in different ways, however the regulation of Sef stability remains unknown. The possible role of c-Cbl in the regulation of Sef protein degradation was investigated. Results from coimmunoprecipitation and immunostaining assays reveal that hSef colocalizes and interacts with c-Cbl. Data suggest that the interaction between hSef and c-Cbl results in the ubiquitination and subsequent degradation of the hSef protein. It was proposed that c-Cbl may serve as a modulator to regulate Sef protein stability during FGF signal transduction.

Cell Line ; Clustered Regularly Interspaced Short Palindromic Repeats ; genetics ; DNA ; metabolism ; Deoxyribonuclease I ; metabolism ; Embryonic Stem Cells ; cytology ; metabolism ; Homologous Recombination ; Humans ; Pulmonary Surfactant-Associated Protein C ; genetics

With their capability to undergo unlimited self-renewal and to differentiate into all cell types in the body, human embryonic stem cells (hESCs) hold great promise in human cell therapy. However, there are limited tools for easily identifying and isolating live hESC-derived cells. To track hESC-derived neural progenitor cells (NPCs), we applied homologous recombination to knock-in the mCherry gene into the Nestin locus of hESCs. This facilitated the genetic labeling of Nestin positive neural progenitor cells with mCherry. Our reporter system enables the visualization of neural induction from hESCs both in vitro (embryoid bodies) and in vivo (teratomas). This system also permits the identification of different neural subpopulations based on the intensity of our fluorescent reporter. In this context, a high level of mCherry expression showed enrichment for neural progenitors, while lower mCherry corresponded with more committed neural states. Combination of mCherry high expression with cell surface antigen staining enabled further enrichment of hESC-derived NPCs. These mCherry(+) NPCs could be expanded in culture and their differentiation resulted in a down-regulation of mCherry consistent with the loss of Nestin expression. Therefore, we have developed a fluorescent reporter system that can be used to trace neural differentiation events of hESCs.
Animals ; Cell Differentiation ; Cell Line ; Embryonic Stem Cells ; cytology ; metabolism ; transplantation ; Gene Knock-In Techniques ; Genes, Reporter ; Homologous Recombination ; Humans ; Luminescent Proteins ; genetics ; Mice ; Mice, SCID ; Nestin ; genetics ; Neural Stem Cells ; cytology ; metabolism ; Neurons ; cytology ; metabolism ; Teratoma ; pathology

Objective:To assess the value of radiofrequency ablation versus sclerotherapy for perforating venous reflux in the treatment of venous ulceration.Methods:This study included 56 patients with venous ulceration (C5/C6, 56 limbs) treated at Peking Union Medical College Hospital in 2018. The patients underwent radiofrequency ablation (Group A, 30 patients) or sclerotherapy (Group B, 26 patients) of perforating venous reflux.Results:The immediate success rate was 100%. During 1 to 12-month follow-up, 5 patients (1 in Group A and 4 in Group B) had recurrent venous ulcers. Recanalization of perforating veins was found in 8 patients (2 in Group A and 6 in Group B). The rates of free from venous ulcer′s recurrence in Group A and Group B were 92.6%±5.1% and 82.7%±8.0%, respectively. The rates of free from perforating vein recanalization were 88.4%±6.3 % and 61.5%±11.2% in Group A and Group B respectively. Univariate analysis of postoperative venous recanalization and ulceration recurrence revealed significant correlation between operation methods, perforating vein diameter and occurrence of adverse events. Specifically, radiofrequency ablation is associated with better outcome than sclerotherapy ( P=0.016), and perforating veins with diameter less than 3.5mm is associated with better outcome than those with diameter≥3.5mm( P=0.048). By multivariate regression analysis , operation type was the only risk factor of poor prognosis ( P=0.040). Conclusion:Radiofrequency ablation of perforating veins resulted in reduced rates of mid-term recanalization and ulceration recurrence compared with ultrasound-guided sclerotherapy.

Sef (similar expression to fgf genes) was identified as a feedback antagonist of FGF signaling in zerbrafish, mouse and human. To construct recombinant adenoviral vectors expressing hSef-L and hSef-S, the coding sequences of the two isoforms were amplified and ligated into pAdTrack-CMV, forming shuttle vectors pAdTrack-CMV/hSef-L-Myc and pAdTrack-CMV/hSef-S-Myc. After sequence confirmation, these two shuttle vector plasmids were linearized by Pme I and then co-transformed respectively with the adenoviral genome vector pAdEasy-1 into E. coli BJ5183. The successful recombinants were selected by Kanamycin and confirmed by Pac I digestion. The recombinant vectors Ad-hSef-L-Myc and Ad-hSef-S-Myc were finally digested with Pac I and transfected into HEK293 cells to pack into viral particles. The virus were amplified in 293 cells and used to infect MEF cells. Western blotting analysis was used to demonstrate the expression of hSef-L-Myc and hSef-S-Myc proteins. The inhibitory effects of the adenovirus mediated Sef expression on FGF signaling was further evaluated by Elk luciferase reporter assay. Our results indicated the constructed virus could produce effectively the proteins and then inhibit FGF signaling in MEF cells.
Adenoviridae ; genetics ; metabolism ; Cell Line ; Cloning, Molecular ; Defective Viruses ; genetics ; metabolism ; Escherichia coli ; genetics ; metabolism ; Genetic Vectors ; genetics ; Humans ; Protein Isoforms ; biosynthesis ; genetics ; Receptors, Interleukin ; biosynthesis ; genetics ; Recombinant Proteins ; biosynthesis ; genetics ; Transfection ; Virus Cultivation ; methods

OBJECTIVE: To explore the feasibility to measure the anatomy landmarks in the anatomy research, even in the operation by the MicronTracker binocular visual navigation system, and to study the anatomy of the transnasal endoscopic surgery of skull base. METHOD: We designed a new anatomy data collection system based on the MicronTracker binocular visual navigation system to measure and record the anatomy landmarks, and measured the angles and distances between the related planes and the important structures on 67 dry adult cranium specimens (32 male, 35 female). RESULT: 1) The system is reliable, the angles and the distances can be acquired in the real time. 2) The major date of the landmarks was the pitch of the Frankfurt horizontal plane according to the frontal bone plane, male: (77.7 +/- 4.7) degrees, female: (81.6 +/-4.5) degrees; the pitch of the bony nasal floor according to the frontal bone plane, male: (78.6 +/- 5.8) degrees, female: (82.0 +/- 4.5) degrees; from the same side of nasal spine to the anterior edge of foramen lacerum, pitch, male: (61.3 +/- 7.6) degrees, female: (65.6 +/-7.1) degrees, azimuth, male: (7.0 +/- 2.6) degrees, female: (7.1 +/- l.8) degrees, the distance, male: (68.9 +/- 4.1) mm, female: (66.3 +/- 3.9) mm; from the same side of the nasal spine to the aperture of the sphenoidal sinus, pitch, male: (40.5 +/- 9.3) degrees, female: (46.4 +/- 6. 8) degrees, azimuth, male: (2.1 +/- 1.8) degrees, female: (3.6 +/- 2. 6) degrees, the distance, male: (56.2 +/- 3.1) mm, female: (53.4 +/- 3.0) mm. CONCLUSION 1) The anatomy data collection system based on the MicronTracker binocular visual navigation system can be used to measure the anatomy landmarks conveniently, accurately and quickly. 2) The relationship between the landmarks of the skull base and the nasal cavity and the frontal bone plane and the sagittal plane is stable, and the planes can be used as the datum plane to look for the landmarks in the transnasal endoscopic surgery of skull base.
Adult ; Anatomy ; instrumentation ; Endoscopy ; Female ; Humans ; Male ; Nasal Bone ; anatomy & histology ; surgery ; Nasal Cavity ; anatomy & histology ; surgery ; Nose ; anatomy & histology ; surgery ; Skull Base ; anatomy & histology ; surgery

Objective:To summarize the surgical treatment of malignant carotid body tumor (MCBT).Methods:A retrospective analysis of 14 MCBT patients admitted at our hospital from Mar 2005 to Nov 2019 was made, and the imaging data, surgical records, perioperative complications and follow-up data were collected.Results:There were 8 males and 6 females, with an average age of (40.8±11.3) years. 10 patients underwent surgical resection of CBT, with one case undergoing tumor enucleation only, nine cases underwent internal carotid artery reconstruction, and all patients underwent intraoperative lymph node biopsy.Tumors were completely removed in all 10 patients. No perioperative death or cerebral infarction occurred. The intraoperative blood loss was (955±658.5) ml. Four patients had permanent nerve injury after surgery. The follow-up time ranged 1-132 months. There were no cases of cerebral infarction or death, and the reconstructed graft remained patent. Apart from the 2 patients who developed tumor metastasis after surgery, other patients recovered uneventfully with no disease progression.Conclusions:Surgery is still the main treatment for MCBT, but MCBT is large and Shamblin class is more advanced. Therefore, complete tumor removal and reconstruction of the carotid arteries are difficult. Surgery should seek to completely remove the tumor and neck lymph node biopsy should be performed to determine the lymph node metastasis.

CRISPR-Cas Systems ; Cell Survival ; Genetic Loci ; genetics ; Genome ; genetics ; HEK293 Cells ; Humans ; Luminescent Proteins ; analysis ; Optical Imaging ; methods

Objective To determine the incidence and clinical features of headache after carotid endarterectomy (CEA).Methods A retrospective analysis was made on the data of patients undergoing CEA in the Department of Vascular Surgery,Peking Union Medical College Hospital from Jan 2014 to Jan 2015.There were 119 males and 24 females,including 97 cases of symptomatic carotid stenosis and 110 cases of severe carotid stenosis.Results The incidence of newly emergent headache after surgery was 44％ (63/143).The earliest time of headache was 30 minutes after surgery and the latest was 6 days after surgery.95％ of headache occurred within 48 hours after surgery (60/63).79.4％ (50/63) of the headache lay ipsilaterally with CEA,and bilateral headache accounted for 20.6％ (13/63).Severe headache accounted for 4.8％ (3/63),all were ipsilaterally frontal and temporal headache,complicating central nervous system symptoms.Conclusions After CEA headache is a common clinical symptom.Most were mild to moderate and unilateral,which can be relieved spontaneously.Cerebral hemodynamics need to be further examined to differentiate the different pathological states of severe headache on the operative side after CEA because of the high risk of developing hyperperfusion syndrome or cerebral infarction.History of TIA or stroke is the risk factor of post-CEA headache.