Effects of different crosslinking treatments on the properties of decellularized small intestinal submucosa porous scaffolds / 北京大学学报(医学版)

OBJECTIVE@#To compare the effects of three different crosslinkers on the biocompatibility, physical and chemical properties of decellularized small intestinal submucosa (SIS) porous scaffolds.@*METHODS@#The SIS porous scaffolds were prepared by freeze-drying method and randomly divided into three groups, then crosslinked by glutaraldehyde (GA), 1-ethyl-3-(3-dimethylaminopropyl) carbodi-imide (EDC) and procyanidine (PA) respectively. To evaluate the physicochemical property of each sample in different groups, the following experiments were conducted. Macroscopic morphologies were observed and recorded. Microscopic morphologies of the scaffolds were observed using field emission scanning electron microscope (FESEM) and representative images were selected. Computer software (ImageJ) was used to calculate the pore size and porosity. The degree of crosslinking was determined by ninhydrin experiment. Collagenase degradation experiment was performed to assess the resistance of SIS scaffolds to enzyme degradation. To evaluate the mechanical properties, universal mechanical testing machine was used to determine the stress-strain curve and compression strength was calculated. Human bone marrow mesenchymal cells (hBMSCs) were cultured on the scaffolds after which cytotoxicity and cell proliferation were assessed.@*RESULTS@#All the scaffolds remained intact after different crosslinking treatments. The FESEM images showed uniformed interconnected micro structures of scaffolds in different groups. The pore size of EDC group[(161.90±13.44) μm] was significantly higher than GA group [(149.50±14.65) μm] and PA group[(140.10±12.06) μm] (P < 0.05). The porosity of PA group (79.62%±1.14%) was significantly lower than EDC group (85.11%±1.71%) and GA group (84.83%±1.89%) (P < 0.05). PA group showed the highest degree of crosslinking whereas the lowest swelling ratio. There was a significant difference in the swelling ratio of the three groups (P < 0.05). Regarding to the collagenase degradation experiment, the scaffolds in PA group showed a significantly lower weight loss rate than the other groups after 7 days degradation. The weight loss rates of GA group were significantly higher than those of the other groups on day 15, whereas the PA group had the lowest rate after 10 days and 15 days degradation. PA group showed better mechanical properties than the other two groups. More living cells could be seen in PA and EDC groups after live/dead cell staining. Additionally, the proliferation rate of hBMCSs was faster in PA and EDC groups than in GA group.@*CONCLUSION@#The scaffolds gained satisfying degree of crosslinking after three different crosslinking treatments. The samples after PA and EDC treatment had better physicochemical properties and biocompatibility compared with GA treatment. Crosslinking can be used as a promising and applicable method in the modification of SIS scaffolds.

Effect of glucose metabolism disorders on the short-term prognosis in neonates with asphyxia: a multicenter study in Hubei Province, China / 中国当代儿科杂志

OBJECTIVES@#To study the effect of glucose metabolism disorders on the short-term prognosis in neonates with asphyxia.@*METHODS@#A retrospective analysis was performed on the medical data of the neonates with asphyxia who were admitted to 52 hospitals in Hubei Province of China from January to December, 2018 and had blood glucose data within 12 hours after birth. Their blood glucose data at 1, 2, 6, and 12 hours after birth (with an allowable time error of 0.5 hour) were recorded. According to the presence or absence of brain injury and/or death during hospitalization, the neonates were divided into a poor prognosis group with 693 neonates and a good prognosis group with 779 neonates. The two groups were compared in the incidence of glucose metabolism disorders within 12 hours after birth and short-term prognosis.@*RESULTS@#Compared with the good prognosis group, the poor prognosis group had a significantly higher proportion of neonates from secondary hospitals (48.5% vs 42.6%, @*CONCLUSIONS@#Recurrent hyperglycemia in neonates with asphyxia may suggest poor short-term prognosis, and it is necessary to strengthen the early monitoring and management of the nervous system in such neonates.

Research progress of the role of IGF-1 in metabolic diseases and the effect of exercise intervention / 生理学报

Insulin-like growth factor-1 (IGF-1) is a peptide with a similar molecular structure to insulin. IGF-1 plays a key role in tissue growth and development, as well as cell metabolism, proliferation, differentiation and apoptosis. Liver is the main source of IGF-1, with the production of IGF-1 up to 75% of the total in the whole body, while the remaining 25% are secreted by skeletal muscles, heart, kidney, spleen and other organs. Target organs of IGF-1 include heart, blood vessels, liver, bone and skeletal muscles. It has been well documented that IGF-1 plays an important role in the prevention and treatment of metabolic diseases. Different types of exercise have different effects on IGF-1 expression with organ differences. In this article, we reviewed the preventive and therapeutic effects of IGF-1 on metabolic diseases and IGF-1-mediated exercise-induced benefits.

Advances in research on risk factors of meibomian gland dysfunction / 国际眼科杂志(Guoji Yanke Zazhi)

@#Meibomian gland dysfunction(MGD)is mainly characterized by terminal duct obstruction and/or qualitative/quantitative changes in the glandular secretion, resulting in the alteration of tear film and ocular surface diseases. It covers several meibomian gland diseases ranging from congenital to acquire. With the progress of clinical research, recent studies indicate there are many risk factors related to MGD, including ophthalmic diseases, systemic diseases, therapeutic approaches(topical/systemic medication, surgery)and even environmental factors. Thus, a proper understanding of the various risk factors acting on MGD will be helpful to the clinical diagnosis and treatment of MGD.

Preparation and osteogenic effect study of small intestinal submucosa sponge / 北京大学学报(医学版)

OBJECTIVE@#To prepare and evaluate the basic properties in vitro of a novel small intestinal submucosa (SIS) sponge, and to describe the bone formation ability of the SIS sponge in vivo.@*METHODS@#The SIS sponge was prepared by freeze-drying method. To evaluate the physicochemical properties of the sponge, electron microscope observation, porosity test, water absorption ability and mechanical property were conducted in vitro. The cytotoxicity of the SIS sponge was performed by cell counting kit-8 method. In vivo experiments, eighteen extraction sockets of premolar of three Beagle dogs were randomly divided into three groups: SIS sponge group (SIS sponge), positive control group (Bio-Oss granules and Bio-Gide membrane) and control group(no treatment). The animals were sacrificed 4 weeks and 12 weeks after operation, and micro computed tomography (Micro-CT) was applied to measure the bone volume fraction (BV/TV) and bone mineralized density (BMD). The data were analyzed with one-way ANOVA.@*RESULTS@#The average pore diameter of the SIS sponge was (194.90±30.39) μm, the porosity was 92.31%±0.24%, the water absorption rate was 771.50%±40.90%, and the compressive elastic modulus was (2.20±0.19) kPa. There was no significant difference in cell proliferation ability between SIS sponge and control group (P>0.05). Micro-CT quantitative results showed that BV/TV of SIS sponge group (52.81%±3.21%) and positive control group (58.30%±9.36%) were significantly higher than that of control group (38.65%±4.80%) 4 weeks after operation (P < 0.05). The BMD of SIS sponge group [(887.09±61.02) mg/cm3], positive control group [(952.05±132.78) mg/cm3] and control group [(879.29±74.27) mg/cm3] showed no statistical difference 4 weeks after operation (P>0.05). The BV/TV of positive control group (60.57%± 6.56%) was significantly higher than that of SIS sponge group (47.89%±3.59%) and control group (42.99%±2.54%) 12 weeks after operation (P < 0.05). BMD of SIS sponge group [(1047±89.95) mg/cm3] and positive control group [(1101.37±98.85) mg/cm3] were significantly higher than that of control group [(890.36±79.79) mg/cm3] 12 weeks after operation (P < 0.05).@*CONCLUSION@#The SIS sponge has satisfying physicochemical properties and biocompatibility. The SIS sponge significantly increased bone volume fraction in the early stage of bone formation (4 weeks) and bone mineralized density in the late stage of bone formation (12 weeks).

Biodegradation properties of multi-laminated small intestinal submucosa / 北京大学学报(医学版)

OBJECTIVE@#To study the biodegradation properties of multi-laminated small intestinal submucosa (mSIS) through in vitro and in vivo experiments, comparing with Bio-Gide, the most widely used collagen membrane in guided bone regeneration (GBR) technique, for the purpose of providing basis to investigate whether mSIS meets the requirements of GBR in dental clinics.@*METHODS@#The degradation properties were evaluated in vitro and in vivo. In vitro degradation was performed using prepared collagenase solution. Morphology of mSIS and Bio-Gide in degradation solution were observed and the degradation rate was calculated at different time points. In in vivo experiments, nine New Zealand rabbits were used for subcutaneous implantation and were divided into three groups according to observation intervals. Six unconnected subcutaneous pouches were made on the back of each animal and were embedded with mSIS and Bio-Gide respectively. At the end of weeks 4, 8, and 12 after operation, gross observation and HE staining were used to evaluate the degree of degradation and histocompatibility.@*RESULTS@#In vitro degradation experiments showed that mSIS membrane was completely degraded at the end of 12 days, while Bio-Gide was degraded at the end of 7 days. Besides, mSIS maintained its shape for longer time in the degradation solution than Bio-Gide, indicating that mSIS possessed longer degradation time, and had better ability to maintain space than Bio-Gide. In vivo biodegradation indicated that after 4 weeks of implantation, mSIS remained intact. Microscopic observation showed that collagen fibers were continuous with a few inflammatory cells that infiltrated around the membrane. Bio-Gide was basically intact and partially adhered with the surrounding tissues. HE staining showed that collagen fibers were partly fused with surrounding tissues with a small amount of inflammatory cells that infiltrated as well. Eight weeks after operation, mSIS was still intact, and was partly integrated with connective tissues, whereas Bio-Gide membrane was mostly broken and only a few residual fibers could be found under microscope. Only a small amount of mSIS debris could be observed 12 weeks after surgery, and Bio-Gide could hardly be found by naked eye and microscopic observation at the same time.@*CONCLUSION@#In vitro degradation time of mSIS is longer than that of Bio-Gide, and the space-maintenance ability of mSIS is better. The in vivo biodegradation time of subcutaneous implantation of mSIS is about 12 weeks and Bio-Gide is about 8 weeks, both of which possess good biocompatibility.

Advances in research on risk factors of meibomian gland dysfunction / 国际眼科杂志(Guoji Yanke Zazhi)

@#Meibomian gland dysfunction(MGD)is mainly characterized by terminal duct obstruction and/or qualitative/quantitative changes in the glandular secretion, resulting in the alteration of tear film and ocular surface diseases. It covers several meibomian gland diseases ranging from congenital to acquire. With the progress of clinical research, recent studies indicate there are many risk factors related to MGD, including ophthalmic diseases, systemic diseases, therapeutic approaches(topical/systemic medication, surgery)and even environmental factors. Thus, a proper understanding of the various risk factors acting on MGD will be helpful to the clinical diagnosis and treatment of MGD.

Barrier effect of improved porcine small intestinal submucosa absorbable membrane on early healing of mandibular defects in rabbits / 北京大学学报(医学版)

OBJECTIVE@#To evaluate the barrier effect of an absorbable barrier membrane made by small intestinal submucosa (SIS) compared with Bio-Gide collagen membrane.@*METHODS@#12 healthy New Zealand male white rabbits were randomly assigned. A or B round bone defects with a depth of 2 mm and a diameter of 5 mm or 8 mm was made in each rabbit's mandibular. The following treatments were given respectively: covered with SIS membrane (S), covered with Bio-Gide membrane (G) and blank control (O). Then we got six groups: AS, AG, AO, BS, BG, and BO (n=4). After 4 weeks, the rabbits were sacrificed. The specimens were examined by naked-eye observation, new bone percentage (BV/TV) and bone mineralized density (BMD), which were measured and analyzed by Micro-CT. The data were analyzed with one-way ANOVA.@*RESULTS@#After 4 weeks, Bio-Gide membranes were fused with the surrounding tissue while SIS membranes held the form with no significant degradation. In the AS, BS and AG groups, the absorbable membranes smoothly covered on the new bone. While in the BG group, Bio-Gide membranes collapsed to the center of the bone defects. The 3D reconstruction of Micro-CT showed that a large number of newly formed trabeculae were found in the four groups of AS, BS, AG, and BG. In the central subsidence area of the BG group, the newly formed trabeculae were sparse. However only a small amount of new bone trabecula appeared at the bottom of the defects in groups AO and BO. Micro-CT quantitative results showed that BV/TV (39.10%±0.79%) and BMD [(517.73±11.22) mg/cm3] of AS group were significantly higher than those of AO group [26.67%±1.12%, (319.81±8.00) mg/cm3] (P<0.05), and there was no significant difference between AS group and AG group [38.15%±0.91%, (518.65±7.48) mg/cm3] (P>0.05). BV/TV (34.90%±1.35%) and BMD [(409.09±8.14) mg/cm3] of BS group were significantly higher than those of BO group [23.63%±2.07%, (171.00±16.24) mg/cm3] (P < 0.05). Meanwhile, there was no significant difference between BS and BG groups [33.40%±1.06%, (412.70±8.6) mg/cm3] (P>0.05). HE staining analysis revealed that significant bone formation was achieved in the AS, AG, BS and BG groups, and trabecular bone of AS and AG groups were thicker and denser. In AO and BO group, there were scattered new bone tissues in edges of host bone, and no coarse trabecular bone formed.@*CONCLUSION@#In the early healing of two sizes bone defects in rabbit mandibular, SIS membrane and Bio-Gide membrane have a similar barrier effect in guided bone regeneration. And SIS membrane's ability to maintain space for bone regeneration seems to be better.

Voltage-gated sodium channels are involved in regulating the biological functions of microglial cells / 生理学报

Microglial cells are widely distributed in the brain and spinal cord, and usually act as resident immune cells which could provide continuous monitoring roles within the central nervous system. When the cells in the central nervous system are injured, microglial cells are activated and induce a series of biological effects. Recently, several voltage-gated sodium channel subtypes were found to be expressed on the surface of the microglial cells which are able to participate in the regulation of the activation, phagocytosis, secretion of multiple cytokines/chemokines, migration, invasion of microglial cells, and etc. In the present study, the latest progresses on the regulation of voltage-gated sodium channel isoforms on microglial cells were summarized and analyzed. In addition, the mechanism and future research of the relationship between voltage-gated sodium channels and microglial cells were also discussed.

Application of free flap pedicled with supracarpal cutaneous branch of ulnar artery in repairing of finger replantation / 中国骨伤

<p><b>OBJECTIVE</b>To evaluate clinical application and clinical outcomes of free flap pedicled with supracarpal cutaneous branch of ulnar artery in repairing of finger replantation with skin defect.</p><p><b>METHODS</b>From April 2007 to March 2013,25 patients affected by finger amputation with skin defect were replanted and repaired by free flap pedicled with supracarpal cutaneous branch of ulnar artery. Among them, 18 patients were male and 7 were female,with an average age of 31.5 years old (ranged 16 to 58). The time of trauma to admission ranged from 45 to 210 min (averaged 105). Fifteen patients were complete separted, and 10 patients were non-complete separated. The area of flaps ranged from 3.5 cm x 2.0 cm to 4.5 cm x 3.0 cm, and the vessels were anastomosed through end-to-end. The functional evaluation standard of finger replantation was used to evaluate the postoperative function.</p><p><b>RESULTS</b>Twenty-four cases were finally survived. Two flaps occurred vascular crisisin within 48 h after operation, one of which was survived after anti-vasospasm treatment and changing dressing,another was replanted finger for failed to survive. One had infection and healed after changing dressing. Twenty-four cases were followed up from 3 to 38 months with an average of 16.5 months. The appearance and texture of flaps were satisfactory, and the superficial senses of pain and touch were recovered,and two-point discrimination was 5.5 to 11 mm (averaged 7.4 mm). According to functional evaluation standard finger replantationissued by Hand Surgery Association of Chinese Medical Association, 8 cases got excellent results, 14 good and 2 poor.</p><p><b>CONCLUSION</b>The free flap pedicled with supracarpal cutaneous branch of ulnar artery can be used in complex finger replantation with skin and vessels defect, which can extend operation indications, recover function and appearance for maximum.</p>

One-hour after-school exercise ameliorates central adiposity and lipids in overweight Chinese adolescents: a randomized controlled trial / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The prevalence of overweight and obesity in Chinese children and adolescents was increasing during the past few decades. The goal of this study was to investigate the effects of after-school exercise with or without diet restriction on total and central obesity, fitness level, and metabolic profile in overweight Chinese adolescents.</p><p><b>METHODS</b>A ten-week weight loss trial was performed using a 2 × 2 block design (exercise × diet). Ninety-three overweight adolescents (average age: (13.6 ± 0.7) years; body mass index (BMI): 22.4 - 34.1 kg/m(2)) were randomly assigned to four groups: 1) diet (D); 2) exercise (EX); 3) diet plus exercise (DEX); and 4) overweight control (C). Caloric intake recipes were enacted based on individual age and corresponding ideal body weight. One-hour after-school exercise was performed once per day, four days per week for ten weeks. Changes of anthropometry, body composition, aerobic fitness, and metabolic biomarkers were determined.</p><p><b>RESULTS</b>Groups D, EX and DEX had a significant decrease in BMI (P < 0.01) after the intervention. The percentage of body and truncal fat, and waist circumference were independently reduced by exercise (P < 0.05 and P < 0.01), but not diet. The decrease in body fat percentage was positively related with the exercise compliance (r = 0.34, P = 0.01). Exercise decreased truncal fat percentage and waist circumference, suggesting a reduction of central adiposity, but did not significantly affect body weight and BMI. Exercise significantly reduced serum low-density lipoprotein cholesterol (P = 0.037), which was positively correlated with decreases of truncal fat percentage (r = 0.222, P = 0.048). No significant effects of interventions on insulin sensitivity, early insulin release index, and aerobic fitness were observed.</p><p><b>CONCLUSION</b>At least twice a week of one-hour after-school exercise significantly attenuated central adiposity and had a significant impact on lipid profiles in overweight Chinese adolescents.</p>

Analysis on epidemiologic characteristics of viral diarrhea among infants in Taiyuan, Shanxi province, 2007-2008 / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To study the epidemiologic characteristics of virus-induced acute diarrhea in children under 5 years old in Taiyuan, Shanxi province.</p><p><b>METHODS</b>Stool specimens and clinical data were collected from 346 inpatients with acute diarrhea from children less than 5 years old. Rotavirus-positive specimens were identified by ELASA kit. Calicivirus and astrovirus were detected by reverse transcription-polymerase chain reaction (RT-PCR). Adenovirus was done by polymerase chain reaction (PCR).</p><p><b>RESULTS</b>Of the 346 specimens, the percentage of samples with Rotavirus, Calicivirus, Astrovirus, and Adenovirus was 40.8%, 7.5%, 6.4% and 3.2%. Among 141 rotavirus positive samples, serotype G1 (42.6%) was the predominant strain. More than 95% of viral diarrhea patients under hospitalization occurred among children younger than 2 years.</p><p><b>CONCLUSION</b>Rotavirus is the major pathogen contributing to the acute diarrhea. The disease generally peaks at autumn/winter. The predominant rotavirus strain circulated was G1P[8].</p>

Detection of Aichi virus in stool samples from children in Lanzhou / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To identification and analysis Aichi virus from diarrhea and normal children in Lanzhou, and discuss the relationship between Aichi virus and Infant Diarrhea.</p><p><b>METHODS</b>According to the literature published data, Using RT-PCR method to amplified Aichi virus 3CD fragment and the positive products were sequenced and determined, and made the alignment analysis between the nucleotide sequences of the amplified fragment with the known sequence of this virus.</p><p><b>RESULTS</b>There was 1 case detection of Aichi virus in the 46 hospitalized children with diarrhea and 299 children with diarrhea out-patients specifically, Overall detection rate was 0.06%, and there was no Aichi virus was detected in normal control children. 2 viral 3CD gene and the known reference strains of nucleotide sequences were 97%, while phylogenetic analysis showed that genotype of 2 viral belongs to the B.</p><p><b>CONCLUSIONS</b>There existed B Genotype of Aichi virus in China, and more research is needed to clarified the etiology and epidemiology of Aichi virus characteristics.</p>

Detection of bovine rotavirus G10P11 in a diary farm in Daqing, China / 病毒学报

Group A rotavirus are the most frequently detected viral agent associated with the acute diarrhea in calves. In order to investigate the situation of rotavirus strains circulating in diary farms, a total of 117 fecal specimens were collected from diarrhea calves under 4 weeks-age on Yinluo diary farm in Daqing region in China from 2008 to 2009. Ten specimens were detected to be positive by a Rotavirus Group A Diagnostic Kit, which confirmed that the rotavirus was important viral agent associated with diarrhea in this diary farm. Based on the new classification system, G10P[11] genotype was determined in rotavirus positive samples. Sequence and Phylogenetic analysis indicated DQ-75 strain was introduced into our country with imported bovine.