According to the principle of immunomagnetic separation, a novel high-efficient immunomagnetic isolator termed as CMSI 100 for the purification of human CD34 + hematopoietic cells was designed and successfully developed. To do this , neodymium iron boron having magnetic properties superior to any other permanent magnet materials was selected as the key parts of CMSI 100 isolator. The core of the magnet assembly was constructed by sandwiching mild steel bars between 4 pieces of magnet bars of neodymium iron boron. Each piece of magnet bars must be limited to the specifications of 3.5cm?2.0cm?0.3cm so that 2 700 gauss magnetic attractive force could be exerted at the magnet surface. Otherwise magnetic field above the surface of the magnet assembly is either very stronger or weaker, both of which are not beneficial to the enrichment of CD34 + hematopoietic cells. With CMSI 100 immunomagnetic isolator, more than 90% purity and over 95% viability of CD34 + hematopoietic cells could be obtained. These data indicate that CMSI 100 immunomagnetic isolator is as good as the internationally used Isolex TM 50 made by Baxter Company in USA.

Objective:To explore the value of HDlive Flow in prenatal diagnosis of the velamentous placenta.Methods:A total of 2 723 pregnant women underwent prenatal ultrasonography in the second trimester and delivered at Zhejiang Provincial People's Hospital from January 2019 to January 2020, and 48 of them were diagnosed as having velamentous placenta confirmed by postpartum clinical and pathological examination and were included in this retrospective analysis. Two-dimensional echocardiography-color Doppler flow imaging (2D-CDFI) and HDlive Flow were both performed during the prenatal ultrasound examination. The sonographic features of velamentous placenta by HDlive Flow were summarized and the prenatal detection rate between two methods were compared using Chi-square test. Results:The incidence of velamentous placenta was 1.8% (48/2 723) in our hospital. Out of the 48 enrolled cases, 45 were diagnosed by HDlive Flow with a detection rate of 93.8% (45/48), three of them were complicated by vasa previa; the other three cases were misdiagnosed as battledore placenta. There were 38 cases diagnosed by 2D-CDFI with a detection rate of 79.2% (38/48), which was lower than HDlive Flow ( χ2=4.360, P=0.037); the other ten cases were misdiagnosed as battledore placenta. The sonographic features by HDlive Flow were as follow: (1) Umbilical cord attached to fetal membranes outside the placenta in 41 cases with the umbilical vessels distributing along the fetal membrane in a mesh pattern; (2) In three cases, the umbilical cord insertion was located on fetal membranes at the edge of placenta; (3) One case was shown that umbilical cord and the branches of umbilical vessels were inserted into the placenta in a "λ" shape. Conclusions:The anatomy of the umbilical cord, umbilical blood vessels and placenta can be directly shown under HDlive Flow, which can improve the prenatal detection rate of the velamentous placenta.

Objective To study the change of expression of c-fos and c-jun when using IN-1 alone or combination with NT-3 after spinal cord injury. Methods 120 adult health Sprague-Dawley (SD) rats were random divided into three groups, including control group, IN-1 group, and IN-1 combination with NT-3 group. All rats were killed at the scheduled time and its myeloid tissues were taken out. In each group, the expression of c-fos and c-jun gene was detected by using reverse transcription- polymerase chain reaction technique ( RT-PCR ). Result The transcriptional levels of c-fos decreased and c-jun increased when using IN-1 alone, and the levels changed more when using IN-1 combination with NT-3. The peak of c-fos reached to 0. 974 ±0. 126 in control group, 0. 834 ±0. 047 in IN-1 group, and 0. 698 ±0. 052 in IN-1 combination with NT-3 group, and the peak of c-jun reached 0. 642 ±0. 048, 0. 712 ±0. 050, and 0. 814 ±0. 041, respectively. Conclusion One of the mechanisms of IN-1 and NT-3 to protect the spinal cord might be through inhibiting the expression of c-fos and enhancing the expression of c-jun.

Objective To observe the changes of calcitonin gene-related peptide(CGRP) -immunoreactive positive nerve fibers innervation in bone tissue of femoral heads during the pathological process of early steroid-induced avascular necrosis of the femoral head (SANFH), and explore its significance.Methpathological group of SANFH was induced.Immunohistochemical technique was used and the changes of CGRP-immunoreactive positive nerve fibers innervation in weight bearing area of the femoral heads during the pathological process of early SANFH were observed.Result The number of CGRP-immunoreactive nerves increased first and then decreased ( Peaked at 6 weeks, 10.28 ± 0.66 ), but it was more than that ofnormal control group.There was significant difference between two groups ( P ＜ 0.01 ).Conclusion There were changes in the distribution of CGRP-immunoreactive positive nerves fiber during the process of bone repair after SANFH.CGRP-immunoreactive positive nerves fiber might take part in the process of bone repair in SANFH.

Objective:To evaluate the clinical application value of gastrointestinal contrast-enhanced ultrasound combined gas injection method in verifying the location of nasointestinal tube in critically ill patients.Methods:Data of 60 critically ill patients who had the indications of indwelling nasointestinal tube were collected from September 1,2015 to September 1,2016 in the Intensive Care Unit of Zhejiang Provincial People(s) Hospital.The position of nasointestinal tube in patients who underwent bedside blind insertion would be confirmed routinely through gas injection auscultation method.After tube was inserted,its route was scanned by ultrasound with gas perfusion assistance.Afterwards,rapid gas perfusion was used until suspicious tube end position was determined.Furthermore,oral ultrasound contrast agent was injected into the tube if instantaneous strong echo of gas was observed in localized lumen,and contrast agent filling meant the placement being successful.Two methods of position confirmation of nasointestinal tube in critically ill patients included gastrointestinal contrast enhanced ultrasound combined gas injection and gas injection auscultation only,and the effect of the two methods was compared and confirmed by chest and abdominal X ray examinations to verify the location of nasointestinal tube below pylorus.Results:A total of 60 patients were included in this study,58 patients(96.7％)in gastrointestinal contrast enhanced ultrasound combined gas injection group were successfully positioned.Among them,the placements of tube in 56 cases were below pylorus,while 2 cases were above pylorus.The sensitivity,specificity,positive predictive value,negative predictive value and accuracy of location of gastrointestinal contrast enhanced ultrasound combined gas injection method were 96.6％,100％,100％,50％,96.7％ and of gas injection auscultation method were 74.1％,50％,97.7％,6.3％ and 73.3％.The differences of the sensitivity,specificity,negative predictive value and accuracy between the two methods were statistically significant (P ＜ 0.05).Conclusion:Gastrointestinal contrastenhanced ultrasound combined gas injection method is a safe,simple and convenient method with high sen-sitivity,specificity,negative predictive value and accuracy in confirming the location of the nasointestinal tube.

Objective:To investigate the classification of main pancreatic duct and treatment strategy after linear stapler closure of pancreatic neck in laparoscopic pancreaticoduodenectomy (LPD).Methods:The records of 51 consecutive patients with LPD who were treated by linear staple closure technique of pancreatic neck from February to December 2022 from Binzhou Second People′s Hospital, Shijingshan Campus, Beijing Chaoyang Hospital, Capital Medical University, Rizhao Hepatobiliary-Pancreatic-Splenic Surgery Research Institute, Chaoyang Central Hospital, Shandong Juxian People′s Hospital, Weihai Municipal Hospital, Binzhou Central Hospital, and Affiliated Hospital of Chifeng University were retrospectively reviewed. According to the visibility, position and diameter of the main pancreatic duct at the stump of the pancreas, the type of main pancreatic duct was divided into type I, type Ⅱ, type Ⅲa and type Ⅲb. The number of cases in each main pancreatic duct classification and the corresponding treatment strategies were examined.Results:A total of 51 cases of LPD were successfully completed. Of these patients, the males comprised 56.9%(29/51), and females comprised 43.1%(22/51), with age ranging from 31 to 88 years old. The type of the main pancreatic duct at the stump of the pancreas included 7 cases (13.7%) of type Ⅰ, 39 cases (76.5%) of type Ⅱ, 2 cases (3.9%) of type Ⅲa, and 3 cases (5.9%) of type Ⅲb. Corresponding treatment strategies were adopted according to different main pancreatic duct types, the main pancreatic duct was successfully found, and a support drainage tube was inserted.Conclusion:After linear stapler closure of pancreatic neck, corresponding treatment strategies should be adopted according to the classification of the main pancreatic duct, which would help to improve the success rate of finding the main pancreatic duct and placing a support drainage tube.

Objective: To detect the expression level of miR-27a during the osteogenic differentiation of beagle maxillary sinus membrane stem cells (MSMSCs) and explore the role of miR-27a in the osteogenic differentiation of MSMSCs. Methods: Beagle MSMSCs were cultured in vitro. The expression level of miR-27a was detected via RT-PCR after an osteogenic inductive culture was prepared. The mRNA expression levels of Runx2 and OPN were examined via RT-PCR, and the protein expression levels of Runx2 and OPN were examined via Western blot after the cells were transfected with pre-miR-27a or anti-miR-27a. Finally, osteoprogenitor cells transfected with pre-miR-27a were composited with Bio-Oss particles and subcutaneously implanted into nude mice to form ectopic bone formation models, and then the inhibition of bone formation from miR-27a was observed in vivo. Results: The expression level of miR-27a in the beagle MSMSCs decreased after osteogenic inductive culturing. The relative miR-27a levels were significantly decreased at day 1 (t=3.795, P=0.023), day 3 (t=4.493, P=0.011), day 7 (t=11.591, P < 0.001), day 14 (t=12.542, P < 0.001), and day 21 (t=5.621, P=0.008) compared with day 0. In addition, the expression levels of Runx2 mRNA (t=4.923, P=0.007) and protein (t=4.425, P=0.008) were reduced after the cells were transfected with pre-miR-27a. The expression levels OPN mRNA (t=5.253, P=0.006) and protein (t=5.132, P=0.006) were also reduced. In contrast, the mRNA expression levels of Runx2 (t=3.925, P=0.013) and OPN (t=3.712, P=0.019) were increased after the cells were transfected with anti-miR-27a, and bone formation was observed after the subcutaneous implantation of beagle MSMSCs composited with Bio-Oss in nude mice. Nevertheless, ectopic bone formation was inhibited by pre-miR-27a-transfected beagle MSMSCs composited with Bio-Oss (t=7.219, P=0.0020). Conclusion MiR-27a negatively regulates the osteogenic differentiation of MSMSCs.

Objective: To investigate the osteogenic properties of maxillary sinus membrane stem cells (MSMSCs). Methods : Beagle maxillary sinus mucosa was collected, immunomagnetic bead method was applied for isolation of CD146+ cells, and MSMSCs were harvested and cultured from the canine maxillary sinus floor mucosa. The levels of the cell surface antigens CD44, CD146, and CD34 were determined at passage one by flow cytometry. Cells at passage one were cultured in basal medium and osteogenic inductive medium. Real-time PCR, immunohistochemical staining, alkaline phosphatase activity, alizarin red staining and Von Kossa staining were used to investigate the osteogenic properties in vitro. Results: The canine MSMSCs were cultured successfully. The results of flow cytometry were positive for CD146 and CD44 expression but negative for CD34 expression. The relative mRNA expression of runt-related transcription factor 2 (RUNX2) (t = 14.44,P < 0.001), osteopontin (OPN) (t = 7.85,P = 0.001) and alkaline phosphatase alkaline phosphatase (t = 14.27,P < 0.001) was apparently higher in the osteoinductive medium group than in the basal medium group, the differences in relative mRNA expression between the groups were significant. The protein levels of RUNX2 and OPN increased in the osteoinductive medium group. The alkaline phosphatase activity of the MSMSCs increased when the cells were cultured in osteoinductive medium; the activity increased to a level that was significantly higher than that in basal medium, particularly at days 3 (t = 8.79, P < 0.001), 7 (t = 9.75,P < 0.001), 14 (t = 12.14,P < 0.001), 21 (t = 19.62,P < 0.001) and 28 (t = 17.53,P < 0.001). Obvious mineralized nodules were observed by alizarin red staining or Von Kossa staining. Conclusion Maxillary sinus membrane stem cells exhibit osteogenic ability.