[Evaluation and Early Diagnosis of Gastrointestinal Failure in Acute Pancreatitis].

Objective To investigate the application of Acute Gastrointestinal Injury(AGI) grading in evaluating gastrointestinal failure in patients with acute pancreatitis(AP). Methods In this retrospective observational study,patients presented with moderate severe AP and severe AP in our hospital from October 2013 to October 2016 were consecutively enrolled.Logistic regression analysis and receiver operating characteristic curve were used to explore and evaluate potential predictors of gastrointestinal failure. Results A total of 202 patients were included in this study,with 90 cases(44.6%) identified as gastrointestinal failure.Survival curve showed significantly increased risk of death in patients with gastrointestinal failure(P < 0.05).Logistic regression analysis showed age(OR=1.06,95%CI:1.03-1.09,P<0.001),complaint of stopping flatus and defecation(OR=7.02,95%CI:2.08-23.66,P=0.002),increased counts of white blood cells in peripheral blood(OR=1.09,95%CI:1.02-1.17,P=0.015),decreased level of serum albumin(OR=0.93,95%CI:0.86-1.00,P=0.048),and increased level of serum creatinine at admission(OR=1.02,95%CI:1.01-1.04,P=0.001) were the independent risk factors of gastrointestinal failure.The area under curves of Acute Physiology and Chronic Health Evaluation Ⅱ (APACHE Ⅱ) and Beside Index for Severity in Acute Pancreatitis (BISAP) scores in diagnosing gastrointestinal failure were 0.999 and 0.782,respectively. Conclusions Gastrointestinal failure can remarkably increase the risk of death in patients with AP.Both APACHE Ⅱ and BISAP scores at admission are useful in diagnosing gastrointestinal failure in patients with AP.

Yap overexpression attenuates septic cardiomyopathy by inhibiting DRP1-related mitochondrial fission and activating the ERK signaling pathway.

Context: Yes-associated protein (Yap) has been linked to several cardiovascular disorders, but the role of this protein in septic cardiomyocytes is not fully understood. Objective: The aim of our study was to explore the influence of Yap in septic cardiomyopathy in vivo and in vitro. Materials and methods: In the current study, Yap transgenic mice and Yap adenovirus-mediated gain-of-function assays were used in an LPS-established septic cardiomyopathy model. Mitochondrial function and mitochondrial fission were determined through western blotting, immunofluorescence analysis and ELISA. Results: Our results demonstrated that Yap expression was downregulated by LPS, whereas Yap overexpression sustained cardiac function and attenuated cardiomyocyte death. The functional exploration revealed that LPS treatment induced cardiomyocyte mitochondrial stress, as manifested by mitochondrial superoxide overproduction, cardiomyocyte ATP deprivation, and caspase-9 apoptosis activation. Furthermore, we demonstrated that LPS-mediated mitochondrial damage was controlled by mitochondrial fission. However, Yap overexpression reduced mitochondrial fission and therefore improved mitochondrial function. A molecular investigation revealed that Yap overexpression inhibited mitochondrial fission by reversing ERK activity, and the inhibition of the ERK pathway promoted DRP1 upregulation and thereby mediated mitochondrial fission activation in the presence of Yap overexpression. Conclusions: Overall, our results suggest that the cause of septic cardiomyopathy appears to be connected with Yap downregulation. The overexpression of Yap can attenuate myocardial inflammation injury through the reduction of DRP1-related mitochondrial fission in an ERK pathway activation-dependent manner.

Dissecting Molecular Mechanisms Underlying Pulmonary Vascular Smooth Muscle Cell Dedifferentiation in Pulmonary Hypertension: Role of Mutated Caveolin-1 (Cav1F92A)-Bone Marrow Mesenchymal Stem Cells.

BACKGROUND: Pulmonary arterial hypertension (PAH) is characterised by remodelling in vascular smooth muscles, and switching from contractile (differentiated) to synthetic (dedifferentiated) phenotype. This study aimed to investigate the effect of a mutated caveolin-1 (Cav1F92A) gene from bone marrow mesenchymal stem cells (rBMSCs) on phenotypic switching in the smooth muscle cells during PAH. METHODS: Human pulmonary smooth muscle cells (HPASMCs) were treated with monocrotaline (MCT,1µM), and co-cultured with Cav1F92A gene modified rBMSCs (rBMSCs/Cav1F92A). The nitric oxide (NO) production, cell adhesion, cell viability and inflammatory cytokines expression in rBMSCs was measured to evaluate the survival rate of rBMSCs and the changes of inflammatory cytokines. The concentration of NO/cGMP (nitric oxide/Guanosine-3',5'-cyclic monophosphate), the tumour necrosis factor-alpha (TNF-α), transforming growth factor-beta1 (TGF-ß1) mRNA, the expression of contractile smooth muscle cells (SMCs) phenotype markers (thrombospondin-1 and Matrix Gla protein, MGP), the synthetic SMCs phenotype markers (H-caldesmon and smooth muscle gene SM22 alpha, SM22α), cell migration and the morphological changes in rBMSCs/Cav1F92A co-cultured HPASMCs were investigated. RESULTS: Cav1F92A increased NO concentration, cell adhesion, cell viability, anti-inflammatory cytokines interleukin-4 (IL-4), and interleukin-10 (IL-10), but decreased the inflammatory cytokines interleukin-1α (IL-1α), interferon-γ (INF-γ) and TNF-α expression in rBMSCs. rBMSCs/Cav1F92A activated the NO/cGMP, down-regulated TNF-α, TGF-ß1, thrombospondin-1 and MGP expression, up-regulated SM22α and H-caldesmon expression, restored cell morphology, and inhibited cell migration in MCT treated HPASMCs. CONCLUSIONS: rBMSCs/Cav1F92A inhibits switching from contractile to synthetic phenotype in HPASMCs. It also inhibits migration and promotes morphological restoration of these cells. rBMSCs/Cav1F92A may be used as a therapeutic modality for PAH.

[Effects of Vitamin D Receptor on Mucosal Barrier Proteins in Colon Cells under Hypoxic Environment].

To investigate the expressions of mucosal barrier proteins in colon cell line DLD-1 under hypoxic environment in vitro and its mechanism. Methods After DLD-1 cells were treated separately with hypoxia(l% O2),vitamin D(100 nmol/L),or vitamin D plus hypoxia for 48 hours,the expressions of vitamin D receptor(VDR),tight junction proteins zonula occludens-1(ZO-1),occludin,Claudin-1,and adherent junction protein(E-cadherin)were determined by Western blot.Stable VDR knock-down(Sh-VDR)DLD-1 cell line and control DLD-1 cell line were established by lentivirus package technology and the protein expressions after hypoxia treatment were detected. Results Compared with control group,the expressions of occludin,Claudin-1,and VDR increased significantly after hypoxia treatment(all P<0.001).In addition to the protein expressions of occludin,Claudin-1 and VDR,the expressions of ZO-1 and E-cadherin were also obviously higher in vitamin D plus hypoxia group than in single vitamin D treatment group(all P<0.001).After hypoxia treatment,Sh-VDR cell line showed significantly decreased expressions of ZO-1(P<0.001),occludin(P<0.05),Claudin-1(P<0.01)and E-cadherin(P<0.001)when compared with untreated Sh-VDR cell line. Conclusion VDR acts as a regulator for the expressions of intestinal mucosal barrier proteins under hypoxia environment in DLD-1 colon cell line,indicating that VDR pathway may be another important protective mechanism for gut barrier in low-oxygen environment.

The Relationship Between MMP-2 -1306C>T and MMP-9 -1562C>T Polymorphisms and the Risk and Prognosis of T-Cell Acute Lymphoblastic Leukemia in a Chinese Population: A Case-Control Study.

BACKGROUND: T-cell acute lymphoblastic leukemia (T-ALL) is a malignant hematological disease and is often accompanied by a variety of genetic abnormalities. Hence, our study aims to investigate the relationship between MMP-2 -1306C>T and MMP-9 -1562C>T polymorphisms and the risk and prognosis of T-ALL. METHODS: From April 2009 to February 2011, a total of 376 T-ALL patients were chosen as the case group. Meanwhile, 352 healthy people who passed routine health examinations were selected as the control group. A polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay was used to detect the frequency of MMP-2 -1306C>T (rs243865) and MMP-9 -1562C>T (rs3918242) polymorphisms in the study subjects. The serum levels of MMP-2 and MMP-9 were detected using enzyme-linked immunosorbent assay (ELISA). A Kaplan-Meier analysis was employed to analyze the event-free survival (EFS) rates of the T-All patients with different MMP-2 and MMP-9 genotypes. A multivariate COX model was applied to analyze the relationship between MMP-2 and MMP-9 polymorphisms and the prognosis of T-ALL patients. A C-statistic and net reclassification index (NRI) was carried out to evaluate the predictive value of MMP-2 and MMP-9 gene polymorphisms using the Cox model. RESULTS: Compared to the control group, the genotypic frequency of MMP-2 -1306C>T (CT + TT) and MMP-9 -1562C>T (CT + TT) in the case group was significantly higher. The serum level of MMP-9 was markedly elevated in T-ALL patients with the CT + TT genotype compared to patients with the CC genotype. The results of the Kaplan-Meier analysis showed that the median EFS was lower in T-ALL patients with the CT + TT genotype of MMP-9 -1562C>T compared to patients with the CC genotype. The results of a multivariate analysis using the Cox proportional hazard model indicated that the MMP-9 -1562C>T polymorphism was associated with the prognosis of T-ALL patients. CONCLUSION: These results indicated that MMP-2 -1306C/T and MMP-9 -1562C/T polymorphisms might be associated with an increased risk of T-ALL. The MMP-9 -1562C>T polymorphism may also be related to the prognosis of T-ALL patients.

Effects of Blood Purification on Serum Levels of Inflammatory Cytokines and Cardiac Function in a Rat Model of Sepsis.

OBJECTIVE: The study aimed to explore the effects of blood purification (BP) on serum levels of inflammatory cytokines and cardiac function in a rat model of sepsis. METHODS: A rat model of sepsis was established by cecal ligation and puncture. All rats were divided into the normal control, sham operation, model, sham treatment, and BP treatment groups. Cardiac functions, inflammatory cytokines, myocardial enzymes, pathological score of cardiac muscle tissue, and myocardial apoptosis of rats in each group were compared. RESULTS: Sepsis rats had higher serum levels of inflammatory cytokines and lower cardiac function than those in the normal control and sham operation groups. Compared with the model and sham treatment groups, improved cardiac functions, decreased inflammatory cytokines, myocardial enzymes, pathological score, and myocardial apoptosis and mortality were observed in the BP treatment group. CONCLUSION: BP may reduce serum levels of inflammatory cytokines and improve cardiac function of sepsis rats.

Dexmedetomidine reduces Catheter-Related Bladder Discomfort: A Prospective, Randomized, Placebo- Controlled, Double-Blind Study.

OBJECTIVE: To evaluate the efficacy of dexmedetomidine in preventing catheterrelated bladder discomfort (CRBD) in a postanesthesia care unit (PACU). METHODS: A total of 138 consecutive adult male patients, classified by the American Society of Anesthesiologists (ASA) as ASA class I and ASA class II, were scheduled for elective open upper-middle abdominal surgery. They were randomized into 2 groups, C and D, comprising 69 patients each. Group C was given a saline solution as placebo, and group D received dexmedetomidine. Either placebo or drug was administered intravenously at 0.5 µg/kg as each patient's abdomen was being closed. After induction of anesthesia, each patient was catheterized with a 16F Foley catheter and the balloon inflated with 10 mL of distilled water. In the PACU, the incidence and severity (mild, moderate, or severe) of CRBD were assessed 0, 1, 2, and 6 hours after extubation. Postoperative pain (numeric rating scale) and sedation level (Ramsay score) were also assessed at the same time points. The incidence of adverse clinical events after the injection of dexmedetomidine or placebo was monitored. RESULTS: Measured at 0, 1, 2, and 6 hours after extubation, the incidence and severity of CRBD in postoperative group D were significantly reduced compared with those of group C (p<0.01). Dexmedetomidine also helped to relieve postoperative pain and induce deeper sedation 0 and 1 hour after extubation (p<0.05). No significant differences in adverse events other than bradycardia and hypotension were observed in group D (p<0.05). CONCLUSION: Dexmedetomidine (0.5 µg/kg IV) administration during surgery reduced the incidence and severity of CRBD in the PACU without causing significant side effects.

Intensive Care Unit Nurses' Attitudes Toward Truth-Telling, Life-Sustaining Treatment, and Decision-Making Intention for End-of-Life Patients: A Cross-sectional Survey.

Truth-telling and life-sustaining treatment decisions are important elements of the quality of patients' care at the end of life. As the primary caregivers of patients at the end of life in intensive care units (ICUs), ICU nurses play an important role in patient decision making and hospice care. This study aimed to investigate and analyze ICU nurses' attitudes toward truth-telling, attitudes toward end-of-life life-sustaining treatment, and end-of-life decision-making behavioral intentions. One hundred twenty-two ICU nurses participated in this cross-sectional survey. Data were collected using a validated questionnaire. The results showed that ICU nurses' attitudes toward telling patients the truth and end-of-life life-sustaining treatment were both positive, but further improvement is needed. Nurses have a higher willingness to make palliative care decisions for patients at the end of life and to help patients achieve a good death. The truth-telling attitude, the life-sustaining treatment attitude, and whether they knew that cardiopulmonary resuscitation could be legally forgone at the end of life were factors influencing ICU nurses' behavioral intention toward decision making for patients at the end of life (all P s < .05). We conclude that nurses' participation in truth-telling and end-of-life decision making should be promoted, and timely hospice care should be provided to patients to help them achieve a good death.

Human health risk assessment of volatile organic compounds in oil-based drill cuttings of shale gas.

Waste oil-based drill cuttings contain dioxins and volatile organic compounds (VOCs), which have the potential to cause serious health effects in humans. Therefore, this paper took oil-based drill cuttings (OBDCs) as the research object and carried out the testing of VOCs and dioxins content by using GC-MS and HRGCS-HRMS and comprehensively evaluated the content, composition and distribution pattern of VOCs and dioxins and the risk to human health posed by the two pollutants in OBDCs. The results showed that the VOCs did not exceed the emission limits in ESPPI (GB 31571-2015), but it is vital to recognise that 1,2-dichloropropane has the potential to cause cancer risk, with soil and groundwater risk control values of 662.95 mg·kg-1 and 0.066 mg·kg-1, respectively. Benzene, 1,2-dichloropropane and 8 other VOCs pose a non-carcinogenic risk to humans. The levels of polychlorinated dibenzofurans (PCDFs) exceeded those of polychlorinated dibenzo-p-dioxins (PCDDs), which accounted for 95.76 percent of the total PCDD/Fs, 2,3,4,7,8-P5CDF (56.00%), 2,3,7,8-T4CDF (9.20%), 1,2,3,6,7,8-H6CDF (8.80%) and 1,2,3,7,8-P5CDF (8.00%) were the main contributing monomers. The findings of the assessment on exposure risk indicate that there is a respiratory risk to oil-based drill cuttings dioxins for adults and children exceeded the World Health Organisation (WHO) acceptable daily intake (ADI) (1-4 pgTEQ/kg/d). Finally, three aspects of solid waste pre-treatment prior to incineration, the incineration process and post incineration were used to reduce the environmental and human health risks from dioxins.

Temporary bilateral uterine artery occlusion combined with vasopressin in control of hemorrhage during laparoscopic management of cesarean scar pregnancies.

STUDY OBJECTIVE: To describe temporary bilateral uterine artery occlusion with titanium clips in combination with vasopressin as an effective surgical intervention to control hemorrhage during laparoscopic management of cesarean scar pregnancies (CSPs). DESIGN: Retrospective study (Canadian Task Force classification III). SETTING: University hospital in an obstetrics and gynecology department. INTERVENTIONS: Five patients with CSPs underwent removal of gestational ectopic masses via laparoscopy. At the beginning of the procedure, all 5 women had temporary bilateral uterine artery occlusion with titanium clips, and vasopressin 6 U was injected into the myometrium. MEASUREMENTS AND MAIN RESULTS: Clinical data, serum ß-human chorionic gonadotropin levels, operative times, and operative blood loss levels were recorded. The mean gestational age at the time of CSP diagnosis was 9.2 ± 1.9 weeks. The mean serum ß-hCG level on the day of surgery was 14262 ± 12870 IU/L. The mean operative time was 86 ± 21.6 minutes, the mean uterine artery occlusion time was 58 ± 13.8 minutes, and the mean blood loss was 144 ± 79.6 mL. No cases were converted to laparotomy, no blood transfusions were required, and there were no complications. CONCLUSIONS: Laparoscopy combined with titanium clip occlusion of the uterine arteries bilaterally with vasopressin injection is an effective, minimally invasive procedure to preserve the uterus in patients with a CSP.

Management of caesarean scar pregnancies using an intrauterine or abdominal approach based on the myometrial thickness between the gestational mass and the bladder wall.

AIM: To describe our experience with various interventions for caesarean scar pregnancies (CSPs) based on the myometrial thickness between the gestational mass and the bladder. METHODS: All patients were initially administered methotrexate. Then, the appropriate therapies hysteroscopy alone or combined with uterine artery embolization (group A) and direct laparoscopy alone or combined with laparoscopic uterine artery occlusion (group B) was selected based on the myometrial thickness between the gestational mass and the bladder. RESULTS: The uteri of all 53 patients with CSPs were conserved; no conversion to laparotomy or blood transfusion was required. Uterine rupture occurred in one case during surgery in group A. The operative time in group B was longer than group A (42 ± 18 vs. 80 ± 33 min; p = 0.022). The two groups were also similar with respect to other characteristics (p > 0.05). CONCLUSION: Myometrial thickness should be considered during the management of CSPs. Surgical approaches in the treatment of CSPs using 2-mm boundaries may yield an optimal clinical outcome.

Three-dimensional oxygen concentration monitoring in hydrogels using low-cost phosphorescence lifetime imaging for tissue engineering.

Oxygen concentration measurement in 3D hydrogels is vital in 3D cell culture and tissue engineering. However, standard 3D imaging systems capable of measuring oxygen concentration with adequate precision are based on advanced microscopy platforms, which are not accessible in many laboratories due to the system's complexity and the high price. In this work, we present a fast and low-cost phosphorescence lifetime imaging design for measuring the lifetime of oxygen-quenched phosphorescence emission with 0.25 µs temporal precision and sub-millimeter spatial resolution in 3D. By combining light-sheet illumination and the frequency-domain lifetime measurement using a commercial rolling-shutter CMOS camera in the structure of a conventional optical microscope, this design is highly customizable to accommodate application-specific research needs while also being low-cost as compared to advanced instruments. As a demonstration, we made a fluidic device with a gas-permeable film to create an artificial oxygen gradient in the hydrogel sample. Dye-embedded beads were distributed in the hydrogel to conduct continuous emission lifetime monitoring when nitrogen was pumped through the fluidic channel and changed oxygen distribution in the sample. The dynamics of the changes in lifetime co-related with their location in the gel of size 0.5 mm×1.5 mm×700 µm demonstrate the ability of this design to measure the oxygen concentration stably and precisely in 3D samples.

Constructing and evaluating the effect of micron-scale structures on von Willebrand factor damage.

The incidence of clinical complication gastrointestinal bleeding has been proved as consequence of von Willebrand factor (VWF) damage after mechanical circulatory support in clinic. Many studies have been conducted to evaluate VWF damage, of which the most studied influencing factors are mechanical factors such as shear stress. However, in addition to mechanical factors, VWF damage may also be affected by interface factors. To address this issue, a roller pump circulation platform was established to investigate the effect of material surface micron-scale structures distribution on VWF damage in flow state. A composite micro-structure combining microngrating and micronpost was designed and constructed on the surface of Si wafer by lithography and reactive ion etching, and detailed characterization of material surfaces was also performed. Then the changes of VWF antigen, VWF ristocetin cofactor activity, and the degradation of high molecular weight VWF on these surfaces were investigated and compared. The results showed that, with the encryption of surface micro-structures arrangement, the material surface tends to be more hydrophobic, which is beneficial to reduce VWF damage. Therefore, in the design of material surface inside the mechanical circulatory support devices, it can be considered to add some surface micro-structures with a certain distribution density to change the hydrophilicity and hydrophobicity, so as to minimize the VWF damage. These results can provide important references for the evaluation of VWF damage caused by interface factors, and aid in designing material surface inside the mechanical circulatory support devices.

In vitro comparative study of red blood cell and VWF damage on 3D printing biomaterials under different blood-contacting conditions.

Mechanical circulatory support devices (MCSDs) are often associated with hemocompatible complications such as hemolysis and gastrointestinal bleeding when treating patients with end-stage heart failure. Shear stress and exposure time have been identified as the two most important mechanical factors causing blood damage. However, the materials of MCSDs may also induce blood damage when contacting with blood. In this study, the red blood cell and von Willebrand Factor (VWF) damage caused by four 3D printing biomaterials were investigated, including acrylic, PCISO, Somos EvoLVe 128, and stainless steel. A roller pump circulation experimental platform and a rotor blood-shearing experimental platform were constructed to mimic static and dynamic blood-contacting conditions of materials in MCSDs, respectively. Free hemoglobin assay and VWF molecular weight analysis were performed on the experimental blood samples. It indicated that different 3D printing materials and technology could induce different levels of damage to red blood cells and VWF, with acrylic causing the least damage under both static and dynamic conditions. In addition, it was found that blood damage measured for the same material differed on the two platforms. Therefore, a combination of static and dynamic experiments should be used to comprehensively investigate the effects of blood damage caused by the material. It can provide a reference for the design and evaluation of materials in different components of MCSDs.

Revision and Validation of the Chinese Version of the McGill Quality of Life Questionnaire for ICU End-of-Life Patients.

BACKGROUND: Hospice care for end-of-life patients in the ICU should focus on quality of life. Currently, there are no specific quality-of-life measures for ICU end-of-life patients in China. OBJECTIVE: The aim of this study was to revise and culturally adapt the Taiwanese version of the McGill Quality of Life Questionnaire (MQOL-Taiwan) and to test its reliability and validity to provide an effective instrument for assessing the quality of life of ICU patients at the end of life. METHODS: The revision and cultural adaptation of the MQOL-Taiwan were performed to develop a Chinese version of the McGill Quality of Life Questionnaire for ICU end-of-life patients (MQOL-ICU). A total of 156 ICU doctors, 286 ICU nurses and 120 ICU family members of end-of-life patients were surveyed with the revised scale to evaluate the quality of life of ICU patients at the end of life. The content validity, construct validity, and internal consistency of the scale were measured after the revision. RESULTS: The Chinese version of the MQOL-ICU scale was formed based on the MQOL-Taiwan scale, which includes 8 items. For the Chinese version of the MQOL-ICU, the item-content validity index (I-CVI) ranged from 0.789 to 0.905, and the average scale-level content validity index (S-CVI/Ave) was 0.845. After exploratory factor analysis, the Kaiser-Meyer-Olkin (KMO) value was 0.700, and 3 dominant factors were extracted: physical and psychological symptoms, existential well-being, and support. In addition, 70.385% of the total variance was explained. The internal consistency (Cronbach's α) coefficient of the whole MQOL-ICU was 0.804, and the coefficients for the 3 domains ranged from 0.779 to 0.833. CONCLUSION: The Chinese version of the MQOL-ICU showed good reliability and validity, and it can be used to assess the quality of life of ICU patients at the end of life.

A comprehensive comparison of the in vitro hemocompatibility of extracorporeal centrifugal blood pumps.

Purpose: Blood damage has been associated with patients under temporary continuous-flow mechanical circulatory support. To evaluate the side effects caused by transit blood pumping, in vitro hemocompatibility testing for blood damage in pumps is considered a necessary reference before clinical trials. Methods: The hemocompatibility of five extracorporeal centrifugal blood pumps was investigated comprehensively, including four commercial pumps (the Abbott CentriMag, the Terumo Capiox, the Medos DP3, and the Medtronic BPX-80) and a pump in development (the magAssist MoyoAssist®). In vitro, hemolysis was tested with heparinized porcine blood at nominal operating conditions (5 L/min, 160 mmHg) and extreme operating conditions (1 L/min, 290 mmHg) using a circulation flow loop. Hematology analyses concerning the blood cell counts and the degradation of high-molecular-weight von Willebrand factor (VWF) during 6-h circulation were also evaluated. Results: Comparing the in vitro hemocompatibility of blood pumps at different operations, the blood damage was significantly more severe at extreme operating conditions than that at nominal operating conditions. The performance of the five blood pumps was arranged in different orders at these two operating conditions. The results also demonstrated superior hemocompatibility of CentriMag and MoyoAssist® at two operating conditions, with overall low blood damage at hemolysis level, blood cell counts, and degradation of high-molecular-weight VWF. It suggested that magnetic bearings have an advantage in hemocompatibility compared to the mechanical bearing of blood pumps. Conclusion: Involving multiple operating conditions of blood pumps in in vitro hemocompatibility evaluation will be helpful for clinical application. In addition, the magnetically levitated centrifugal blood pump MoyoAssist® shows great potential in the future as it demonstrated good in vitro hemocompatibility.

[Effect of Nucleolin on Lymphoma Proliferation by Regulating Thymidine Kinase 1].

OBJECTIVE: To investigate the mechanism of nucleolin (NCL) involved in lymphoma proliferation by regulating thymidine kinase 1 (TK1). METHODS: Twenty-three patients with diffuse large B-cell lymphoma (DLBCL) were selected and divided into initial treatment group (14 cases) and relapsed/refractory group (9 cases). Serum TK1 and C23 protein in peripheral blood mononuclear cells were detected. Cell models of CA46-NCL-KD (CA46-NCL-knockdown) and CA46-NCL-KNC (CA46-NCL-knockdown negative control) were established by lentivirus vector mediated transfection in Burkitt lymphoma cell line CA46. The half maximal inhibitory concentration (IC50) of CA46-NCL-KD, CA46-NCL-KNC, and CA46 to adriamycin were detected by cell proliferation assay (MTS). The expression of NCL mRNA and protein in CA46-NCL-KD and CA46-NCL-KNC cells were dectected by Q-PCR and Western blot, respectively. The cell cycle of CA46-NCL-KD, CA46-NCL-KNC, and CA46 cells were detected by flow cytometry. The expression of TK1 protein in CA46-NCL-KD and CA46-NCL-KNC cells was detected by an enhanced chemiluminescence (ECL) dot blot assay. RESULTS: The level of serum TK1 in the initial treatment group was 0.43(0-30-1.01) pmol/L, which was lower than 10.56(2.19-14.99) pmol/L in the relapsed/refractory group (P<0-01), and the relative expression level of NCL protein in peripheral blood was also significantly lower. The IC50 of CA46-C23-KD cells to adriamycin was (0.147±0.02) µg/ml, which was significantly lower than (0.301±0.04) µg/ml of CA46-C23-KNC cells and (0.338±0.05) µg/ml of CA46 cells (P<0.05). Compared with CA46-NCL-KNC cells, the expression of NCL mRNA and protein, TK1 protein decreased in CA46-NCL-KD cells, and the proportion of S phase and G2/M phase also decreased, while G0/G1 phase increased in cell cycle. CONCLUSION: The increased expression of NCL in DLBCL and CA46 cells indicates low sensitivity to drug. NCL may participate in regulation of lymphoma proliferation by affecting TK1 expression, thereby affecting the drug sensitivity.

The impact of two different thaw protocols on outcomes of vitrified cleavage-stage embryos transfer.

The objective of this study was to evaluate the gestational results obtained with vitrified-thawed human cleavage-stage embryo by two different thaw protocols. Embryo development was observed to cleavage-stage and embryos were cryopreserved by vitrification on day 3 after oocyte retrieval. 51 cycles were thawed using vitrification warming kit with decreasing concentrations of sucrose in 3 dilutions ( 1.0, 0.5 and 0 mol per L respectively) as group 1, 56 cycles were thawed with decreasing concentrations of sucrose in 5 dilutions ( 0.8, 0.6, 0.33, 0.2 and 0 mol per L respectively) as group 2. Embryo survival (> 50 percent intact blastomeres), complete embryo survival (100 percent intact blastomeres), pregnancy and implantation rates were compared, and development rates the day after thawing were also compared. Multivariate analysis showed a significant difference in embryo immediate morphological survival rate, complete survival and clinical pregnancies rate between the two groups respectively (87.0 vs. 98.6 percent, p=0.000; 71.0 vs 82.0 percent embryo subsequent development rates, mean number of transferred embryos was similar between the two groups. (61.4 vs. 61.3 percent, p=0.502; 2.2 +/ 0.5 vs. 2.4 +/- 0.6, p=0.113). In addition, no differences in implantation rate were observed between two groups (17.7 vs. 25.6 percent, P=0.138). No difference in the multiple pregnancy rates was found among the two groups also.

In vitro study of red blood cell and VWF damage in mechanical circulatory support devices based on blood-shearing platform.

Blood damage induced by mechanical circulatory support devices (MCSDs) remains a significant challenge to optimal clinical care. Although researchers have been conducting in vitro studies, the major determinant of blood damage is still unclear. An optimized capillary tube blood-shearing platform with custom designed parts was constructed to investigate the influence of two flow-dependent parameters (shear stress and exposure time) on the shear-induced damage of red blood cells and von Willebrand factor (VWF). Blood samples under different high shear stress and instantaneous exposure time were obtained by changing the flow rate and the length of capillary tube. Plasma free hemoglobin assay and immunoblotting of VWF were then performed on the sheared blood samples. The quantitative correlation between the hemolysis index and the two flow-dependent parameters was found following the power law mathematical model under the flow condition with high shear stress and instantaneous exposure time. The degradation of high molecular weight VWF was not obvious under high shear stress factor. However, the degradation of high molecular weight VWF was found as the result of the accumulation over exposure time under non-physiological shear stress, which was consistent with the different mechanism of VWF damage comparing to red blood cell damage. Compared to peak shear stress, exposure time has a greater effect on both red blood cell and VWF damage. To improve the hemocompatibility of MCSDs, it is more important to avoid regions of slow blood flow with non-physiological shear stress under laminar flow conditions.

Mathematical models for shear-induced blood damage based on vortex platform.

Non-physiological shear stress in Ventricular Assist Device (VAD) is considered to be an important trigger of blood damage, which has become the biggest shackle for clinical application. The researches on blood damage in literature were limited to qualitative but did not make much quantitative analysis. The purpose of this study was to investigate the quantitative influence of two flow-dependent parameters: shear stress (rotational speed) and exposure time on the shear-induced damage of red blood cells and von Willebrand Factor (vWF). A vortex blood-shearing platform was constructed to conduct in vitro experiments. Free hemoglobin assay and vWF molecular weight analysis were then performed on the sheared blood samples. MATLAB was used for regression fitting of original experimental data. The quantitative correlations between the hemolysis index, the degradation of high molecular weight vWF and the two flow-dependent parameters were found both following the power law model. The mathematic models indicated that the sensitivity of blood damage on red blood cells and vWF to exposure time was both greater than that of shear stress. Besides, the damage of vWF was more serious than that of red blood cells at the same flow condition. The models could be used to predict blood damage in blood-contacting medical devices, especially for the slow even stagnant blood flow regions in VAD, thus may provide useful guidance for VAD development and improvement. It also indicated that the vortex platform can be used to study the law of blood damage for the simple structure and easy operation.