Lactide一glycolide copolymerization with stannous octanoate as an initiator and dedecanolas regulator was carried out.The effect of reaction condition such as reaction time,temperature, initiatorconcentration, regulator and monomer ratbonpolymerization conversion,molecular weight and its distrbu-tion were investigated.The obtained results show that the finest reaction condition are initiator 0. 075%,ternperature 170℃ and reaction time 6hr.At this reaction condition,both molecular weight and polymer-ization conversion obtained are vecy high.

OBJECTIVETo evaluate the effect of human hair keratin (HHK) in peripheral nerve repair and explore the mechanism of sciatic nerve regeneration.

METHODSRat models of sciatic nerve damage was established by creating a 10-mm gap in the sciatic nerve, which was bridged with a HHK implant. Histological examinations of the nerve tissues were performed at different time points after the surgery.

RESULTSDuring the period from 2 days to 2 weeks following HHK implantation, Schwann cells were found to undergo dedifferentiation and proliferate along the HHK implant. Three weeks after HHK implantation, numerous macrophages and megakaryocytes occurred around the HHK, and a large quantity of regenerated Schwann cells aligned in orderly fashion was seen between the fine filaments of partially degraded HHK, where axons and capillaries were also observed. Six weeks later, massive nerve fibers and capillaries developed around the HHK, and at 9 weeks, the HHK implant was substantially degraded and numerous regenerated nerve fibers occurred characterized by obvious epineurium and perineurium. Till 12 weeks after HHK implantation, HHK was almost completely degraded and replaced by the newly regenerated nerve fibers that had grown across the nerve defect.

CONCLUSIONSHHK is an ideal material for nerve injury repair. Apocytosis plays a key role in the differentiation process of highly differentiated Schwann cells into immature Schwann cells following nerve injury. As a protective mechanism, the axons undergo enclosure and dissociation following injuries, and the intact axons give rise to growth cones that extend fibers of growing buds to competitively bind the one or more Schwann cells, but only one such but finally develops into a complete axon. The nerve fiber barrier membrane is derived from the capillary menchymal stem cells and the outmost vascular barrier membrane. The regeneration of the Schwann cells, axons and the nerve membrane is the result of self-organization through a well synchronized and coordinated mechanism.

Animals ; Female ; Hair ; chemistry ; Humans ; Keratins ; administration & dosage ; pharmacology ; Male ; Nerve Regeneration ; drug effects ; physiology ; Prostheses and Implants ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Sciatic Nerve ; injuries ; physiopathology

To investigate the crucial role of particle size in the biological effects of nanoparticles, a series of mesoporous silica nanoparticles (MSNs) were prepared with particle size gradients (50, 100, 150, 200 nm) with the traditional Stober method and adjusting the type and ratio of the silica source. The correlation between toxicity and size-caused biological effects were then further examined both in vitro and in vivo. The results indicated that the prepared MSNs had a uniform size, good dispersal, and ordered mesoporous structure. Hemolytic toxicity was found to be independent of particle size. At the cellular level, MSNs with smaller particle sizes were more readily internalized by cells, which initiated to more intense oxidative stress, therefor inducing higher cytotoxicity, and apoptosis rate. In vivo studies demonstrated that MSNs primarily accumulated in the liver and kidneys of mice. Pharmacokinetic analysis revealed that larger MSNs were eliminated more efficiently by the urinary system than smaller MSNs. The mice's body weight monitoring, blood tests, and pathological sections of major organs indicated good biocompatibility for MSNs of different sizes. Animal welfare and the animal experimental protocols were strictly consistent with related ethics regulations of Zhejiang Chinese Medical University. Overall, this study prepared MSNs with a particle size gradient to investigate the correlation between toxicity and particle size using macrophages and endothelial cells. The study also examined the biosafety of MSNs with different particle sizes in vivo and in vitro, which could help to improve the safety design strategy of MSNs for drug delivery systems.

OBJECTIVETo achieve secretory and extracellular production of recombinant dengue virus serotypes I-IV envelope glycoprotein domain III (DENV-1-4 EDIII) in Pichia pastoris.

METHODSEDIII genes of DENVI-IV were amplified and cloned into vector pPIC9K, respectively. These recombinant plasmids were then linearized and transferred into Pichia pastoris strain GS115. Clones highly produced in 4.0 mg/ml G418 were amplified and induced by methanol to achieve the secreted recombinant proteins. Ni-NTA agarose beads were used for purification, while SDS-PAGE and Western blotting were used for identification.

RESULTSThe recombinant plasmids pPIC9K-DENV-1-4 EDIII were constructed and successfully transferred into Pichia pastoris strain GS115. The recombinant EDIII proteins were expressed in a secretory way with the molecular weight about 12 × 10(3) and specifically identified by anti-His monoclonal antibody and anti-DENVI-IV mice sera.

CONCLUSIONDENVI-IV EDIII proteins are successfully achieved from Pichia pastoris expression system and could be used for development of dengue vaccines, diagnostic reagents and study of biological function of the E protein.

Dengue Virus ; genetics ; Genetic Vectors ; Pichia ; metabolism ; Recombinant Proteins ; genetics ; Viral Envelope Proteins ; secretion

Objective To investigate the clinical effect of apical microsurgery combined with guided bone regeneration(GBR)on refractory apical periodontitis and masticatory function.Methods A total of 82 patients with refractory apical periodontitis admitted to our hospital from June 2019 to September 2021 were selected as the study subjects,and they were divided into the control group and the com-bined group according to the random number table,with 41 cases in each group.The control group was treated with apical microsurgery,and the combined group was treated with apical microsurgery combined with GBR.The clinical efficacy,masticatory function and the levels of bone absorption markers[Wnt3a,osteoprotegerin(OPG),receptor activator of nuclear factor-κB ligand(RANKL)]of patients in the two groups were compared.Results The total effective rate of the combined group(100%)was higher than that of the control group(85.37%),the difference was statistically significant(P<0.05).The masticatory efficiency and bite force of patients in both groups increased gradually 3,6 and 12 months after operation(P<0.05),which were higher in the combined group compared with the control group(P<0.05).The tooth mobility of patients in both groups decreased gradually 3,6 and 12 months after operation,and the tooth mobility of patients 3 and 6 months after operation in the combined group were lower than those in the control group(P<0.05).The levels of Wnt3a and OPG of patients 1 week after operation in both groups increased,which were higher in the combined group compared with the control group(P<0.05).The RANKL level of gingival crevicular fluid of patients 1 week after operation in both groups decreased,and which was lower in the combined group compared with the control group(P<0.05).Conclusion The microapical surgery combined with GBR is effective for refractory apical periodontitis,which can effectively inhibit bone resorption,and improve masticatory function.

OBJECTIVETo measure the energy expenditure of reading and watching TV for young women.

METHODSAll 30 girls in the college were selected according to questionnaire, medical examination, blood test, liver function and thyroid gland level. Energy expenditure of reading and watching TV was measured respectively by the Cosmid K4b2 portable gas analysis system from Italy. Basic metabolic rate (BMR) and resting metabolic rate (RMR) were measured as to analyzing results conveniently.

RESULTSThe energy expenditure in reading was (226.35 +/- 56.07) kJ/h and the heart rate was (69 +/- 5) bmp. For watching TV it was (220.79 +/- 65.69) kJ/h and the heart rate was (68 +/- 5) bmp. BMR was (178.53 +/- 53.51) kJ/h and the heart rate was (62 +/- 6) bmp. RMR was (214.76 +/- 44.56) kJ/h and the heart rate was (65 +/- 6) bpm.

CONCLUSIONSThe energy expenditure in reading should be higher than that of watching TV, however, the difference was not obvious. The expenditure rates might get closer to those of RMR. It might be regarded as an expenditure of very light physical active in Chinese.

Adolescent ; Adult ; Basal Metabolism ; Female ; Humans ; Reading ; Rest ; physiology ; Television

OBJECTIVETo determine the validity of bioelectrical impedance analysis (BIA) in measuring body composition and to compare with the reference stable isotope dilution method.

METHODSAccording to the data from 150 students of Bethune Military Medical College, 16 female young adults with normal BMI were selected as the participants. The experimental period was 14 days. During the experimental period, the subjects were centralized on management. At the first day of the period, double labeled water was given to the subjects orally. The urine collection time-points were 2h, 4h, 6h, 8h and the 2nd to 14th day after the administration of isotope dose. All isotope measurements were made by using an isotope ratio mass spectrometer. From the isotope curing curve, the indexes of body composition were gained. At the same time, the body compositions were also measured by using BIA method every day (3 hours after dinner). The paired t test and Pearson correlations were used to measure the significance and the degree of correlation between the measurements determined by using the two methods.

RESULTSThere were no significant differences between the measurements determined by using the two methods. TBW, FFM, BF and BF% measured with the BIA method were significantly correlated with those measured by using the isotope method (r = 0.556, 0.556, 0.817 and 0.606 respectively).

CONCLUSIONBIA might provide an accurate and reliable assessment in body composition of the healthy Chinese adults.

Adipose Tissue ; anatomy & histology ; Adult ; Anthropometry ; methods ; Body Composition ; Body Mass Index ; Body Water ; Electric Impedance ; Humans ; Male

: Rehabilitation medicine is a medical branch which focused on functional recovery. Function Evaluation is very important in assessing the function of patients, the effect of treatment and the efficiency of rehabilitation. Comprehensive Function Evaluation includes evaluation of physical, psychological, speech and society. Vocal, mental and social evaluation have deep cultural and national background. Therefore every country must have its own Function Evaluation Method. Now we present our design for Comprehensive Evaluation. Based on the cooperation of Department of Rehabilitation, Department of Neurology, Department of Spinal Cord Injury, Department of Speech Therapy and Department of Psychology. The advantages of this method are as follows: 1. The style of ADL, speech and thinking are suitable for the condition of our country. 2. The evaluation result adopts hundred work system, it is easy for medical staff, patients and their family to understand and communicate the result. 3. We make it more accurate, comprehensive and reliable by some simple tests on speech pathology and psychology. 4. We overcome some disadvantages of evaluation indexes because it is not correct and is difficult to be understood before. Now every evaluation index has quantity standard. 5. It is simple and practical. Each subtest takes 20 minutes or more. 6. It has been tested by normal people. The norm and severity grade had been developed. 7. The reliability is tested and is proved to be dependable.

康复医学是以恢复患者功能为中心的医学分支。因此，功能评定无论是在客观地评定患者的功能方面，还是在最终评定治疗结果和康复效率方面都是极为重要的。全面的功能评定包括躯体、精神、言语和社会四个方面。其中，言语、社会功能和认知功能中的思维方式，都具有强烈的民族文化色彩。因此，每个国家都应该有切合自己国情的功能评定方法。但由于我国康复医学发展较晚，至今尚无一套既切合国情，又全面、实用和可靠的功能评定方法。有鉴于此，我们在“中心”顾问室、神经康复科、脊髓损伤康复科、言语治疗科、心理科和老年病科的通力合作下，经过近2年的研究，在吸收国际先进经验的基础上，密切结合国情，设计了本文所述的综合功能评定法。其优点有：1．在饮食、起居等生活方式方面以及在言语、社会、思维等方面，均切合我国国情。2．评定结果采用群众熟悉的100分制，使医务人员、患者和患者家属均易于理解，便于交流和沟通。3．在言语、认知等功能的评定方面，直接由言语和心理学家选择一些简易的言语和心理学测试项目，提高了量表的准确性、全面性和可靠性。4．各项评定指标的量化程度高，在言语、认知和社会方面尤其如此，克服了一些量表中对此类项目的评定指标不够具体和不易掌握的不足。5.简便实用，一次检查对正常人仅需20分钟左右，对患者则无负担。6.本法已在128名正常人中应用，并求出了正常值，据此拟定了功能障碍严重程度的等级，可供参考和应用。7.信度经过检验，证明可靠。 综合功能评定法的正常值、功能障碍严重程度分级及信度研究结果，将陆续报道。

OBJECTIVETo provide basic information for epidemiological research of gastrointestinal (GI) malignant tumors.

METHODSData of GI cancer diagnosed in 15 hospitals of Heilongjiang province between January 1998 and December 2007 were analyzed retrospectively. The data mainly involved the age of onset, initial symptoms, pathological types, clinical staging and types of surgical procedure.

RESULTSGastric cancer was the most common type (45.8%) among the 33,540 GI cancer cases, then were rectal cancer (27.3%) and colon cancer (26.8%). Right colon cancer cases were more common than the left ones (1.3:1.0), particularly in people over 80 (2.1:1.0). Only 1.3% of colorectal cancer could be found in age under 30 years old. In patients aged 50 to 70, advanced gastric cancer accounted for 70.6%, advanced colon cancer 73.4% and advanced rectal cancer 72.4%. Well-moderately differentiated adenocarcinoma in early gastric cancer was 49.7%, early colon cancer 77.3% and rectal cancer 83.2%. Patients undergone radical excision in early gastric cancer accounted for 69.1%, advanced gastric cancer 79.9%, left colon cancer 91.9%, right colon cancer 83.9% and in rectal cancer for 88.3%.

CONCLUSIONSPeople aged 50 to 70 tend to get GI cancer in Heilongjiang province. Gastric cancer is the most common GI cancer. Radical excision is the main choice of therapy.

Adult ; Age Distribution ; Aged ; Aged, 80 and over ; China ; epidemiology ; Colonic Neoplasms ; epidemiology ; pathology ; Colorectal Neoplasms ; epidemiology ; pathology ; Female ; Gastrointestinal Neoplasms ; epidemiology ; pathology ; Humans ; Incidence ; Male ; Middle Aged ; Rectal Neoplasms ; epidemiology ; pathology ; Retrospective Studies ; Sex Distribution ; Stomach Neoplasms ; epidemiology ; pathology