Discovery and functional investigation of BMP4 as a new causative gene for human congenital heart disease.

OBJECTIVE: Aggregating evidence highlights the strong genetic basis underpinning congenital heart disease (CHD). Here BMP4 was chosen as a prime candidate gene causative of human CHD predominantly because BMP4 was amply expressed in the embryonic hearts and knockout of Bmp4 in mice led to embryonic demise mainly from multiple cardiovascular developmental malformations. The aim of this retrospective investigation was to discover a novel BMP4 mutation underlying human CHD and explore its functional impact. METHODS: A sequencing examination of BMP4 was implemented in 212 index patients suffering from CHD and 236 unrelated non-CHD individuals as well as the family members available from the proband carrying a discovered BMP4 mutation. The impacts of the discovered CHD-causing mutation on the expression of NKX2-5 and TBX20 induced by BMP4 were measured by employing a dual-luciferase analysis system. RESULTS: A new heterozygous BMP4 mutation, NM_001202.6:c.318T>G;p.(Tyr106*), was found in a female proband affected with familial CHD. Genetic research of the mutation carrier's relatives unveiled that the truncating mutation was in co-segregation with CHD in the pedigree. The nonsense mutation was absent from 236 unrelated non-CHD control persons. Quantitative biologic measurement revealed that Tyr106*-mutant BMP4 failed to induce the expression of NKX2-5 and TBX20, two genes whose expression is lost in CHD. CONCLUSION: The current findings indicate BMP4 as a new gene predisposing to human CHD, allowing for improved prenatal genetic counseling along with personalized treatment of CHD patients.

[Characteristics and clinical value of intestinal metabolites in children aged 4-6 years with obstructive sleep apnea-hypopnea syndrome]. / 4~6å²é˜»å¡žæ€§ç¡çœ å‘¼å¸æš‚åœä½Žé€šæ°”ç»¼åˆå¾æ‚£å„¿è‚ é“ä»£è°¢äº§ç‰©ç‰¹å¾åŠä¸´åºŠä»·å€¼åˆ†æž.

OBJECTIVES: To study the characteristics and clinical value of intestinal metabolites in children aged 4-6 years with obstructive sleep apnea-hypopnea syndrome (OSAHS). METHODS: A total of 31 children aged 4-6 years with OSAHS were prospectively enrolled as the test group, and 24 healthy children aged 4-6 years were included as the control group. Relevant clinical indicators were recorded. Fecal samples were collected, and non-targeted metabolomics analysis using liquid chromatography-mass spectrometry was performed to detect all metabolites. RESULTS: A total of 206 metabolites were detected, mainly amino acids and their derivatives. There was a significant difference in the overall composition of intestinal metabolites between the test and control groups (P<0.05). Eighteen different metabolites were selected, among which six (N-acetylmethionine, L-methionine, L-lysine, DL-phenylalanine, L-tyrosine, and L-isoleucine) had receiver operating characteristic curve areas greater than 0.7 for diagnosing OSAHS. Among them, N-acetylmethionine had the largest area under the curve, which was 0.807, with a sensitivity of 70.83% and a specificity of 80.65%. Correlation analysis between different metabolites and clinical indicators showed that there were positive correlations between the degree of tonsil enlargement and enterolactone, between uric acid and phenylacetaldehyde, between blood glucose and acetylmethionine, and between cholesterol and 9-bromodiphenyl and procaine (P<0.05). There were negative correlations between the degree of tonsil enlargement and N-methyltyramine, aspartate aminotransferase and indolepropionic acid and L-isoleucine, between alanine aminotransferase and DL-phenylalanine, between indolepropionic acid and L-isoleucine, between uric acid and hydroxyquinoline, and between urea nitrogen and N,N-dicyclohexylurea (P<0.05). The metabolic functional pathways affected by differential metabolites mainly included riboflavin metabolism, arginine and proline metabolism, pantothenic acid and coenzyme A biosynthesis, cysteine and methionine metabolism, lysine degradation and glutathione metabolism. CONCLUSIONS: Intestinal metabolites and metabolic functions are altered in children aged 4-6 years with OSAHS, primarily involving amino acid metabolism disorders. The screened differential intestinal metabolites have potential screening and diagnostic value as biomarkers for OSAHS.

Early-onset diabetes involving three consecutive generations had different clinical features from age-matched type 2 diabetes without a family history in China.

PURPOSE: Early-onset, multigenerational diabetes is a heterogeneous disease, which is often simplistically classified as type 1 diabetes (T1D) or type 2 diabetes(T2D). However, its clinical and genetic characteristics have not been clearly elucidated. The aim of our study is to investigate the clinical features of early-onset diabetes involving three consecutive generations (eDia3) in a Chinese diabetes cohort. METHODS: Of 6470 type 2 diabetic patients, 105 were identified as eDia3 (1.6%). After a case-control match on age, we compared the clinical characteristics of 89 eDia3 patients with 89 early-onset T2D patients without a family history of diabetes (eDia0). WES was carried out in 89 patients with eDia3. We primarily focused on 14 known maturity-onset diabetes of the young (MODY) genes. Variants were predicted by ten tools (SIFT, PolyPhen2_HDIV, PolyPhen2_HVAR, LRT, Mutation Assessor, Mutation Taster, FATHMM, GERP++, PhyloP, and PhastCons). All suspected variants were then validated by Sanger sequencing and further investigated in the proband families. RESULTS: Compared to age-matched eDia0, eDia3 patients had a younger age at diagnosis (26.5 ± 5.8 vs. 29.4 ± 5.3 years, P = 0.001), lower body mass index (25.5 ± 3.9 vs. 27.4 ± 4.6 kg/m2, P = 0.003), lower systolic blood pressure (120 ± 15 vs. 128 ± 18 mmHg, P = 0.003), and better metabolic profiles (including glucose and lipids). Of the 89 eDia3 patients, 10 (11.2%) carried likely pathogenic variants in genes (KLF11, GCK, ABCC8, PAX4, BLK and HNF1A) of MODY. CONCLUSIONS: eDia3 patients had unique clinical features. Known MODY genes were not common causes in these patients.

SMAD1 Loss-of-Function Variant Responsible for Congenital Heart Disease.

As the most common form of developmental malformation affecting the heart and endothoracic great vessels, congenital heart disease (CHD) confers substantial morbidity and mortality as well as socioeconomic burden on humans globally. Aggregating convincing evidence highlights the genetic origin of CHD, and damaging variations in over 100 genes have been implicated with CHD. Nevertheless, the genetic basis underpinning CHD remains largely elusive. In this study, via whole-exosome sequencing analysis of a four-generation family inflicted with autosomal-dominant CHD, a heterozygous SMAD1 variation, NM_005900.3: c.264C > A; p.(Tyr88∗), was detected and validated by Sanger sequencing analysis to be in cosegregation with CHD in the whole family. The truncating variation was not observed in 362 unrelated healthy volunteers employed as control persons. Dual-luciferase reporter gene assay in cultured COS7 cells demonstrated that Tyr88∗-mutant SMAD1 failed to transactivate the genes TBX20 and NKX2.5, two already well-established CHD-causative genes. Additionally, the variation nullified the synergistic transcriptional activation between SMAD1 and MYOCD, another recognized CHD-causative gene. These data indicate SMAD1 as a new gene responsible for CHD, which provides new insight into the genetic mechanism underlying CHD, suggesting certain significance for genetic risk assessment and precise antenatal prevention of the family members inflicted with CHD.

Adsorption properties of ß-cyclodextrin modified hydrogel for methylene blue.

With the development of dye and printing, production wastewater has become one of the most primary pollution sources of water and soil pollution. Most of the dyes are toxic substances, which have the "three-way" effect of carcinogenic, teratogenic and mutagenic. Therefore, it is a very difficult but significant issue to deal with the dye in the wastewater. Here, we report a study on low-cost, high-capacity hydrogels that remove water-soluble dyes. The hydrogel is prepared by crosslinking the ß-cyclodextrin and functional monomer: acrylamido and 2-acrylamide-2-methylpropane sulfonic acid by aqueous solution polymerization, meanwhile, alkaline hydrolysis is also an important step for adsorption performance. After alkaline hydrolysis, the amide and sulfonic groups in the hydrogel were converted into carboxylate and sulfonate, which was beneficial to the adsorption of cationic dyes. This polymer could remove 96.58% methylene blue (400 mg/L) and only requires 0.02 wt%. Its maximum adsorption capacity for methylene blue could reach 2638.22 mg/g under equilibrium condition. It is the most powerful adsorbent used to treat dye wastewater, according to the report. It also provides some references for hydrogel treatment of dye wastewater.

Clinical performance of cantilevered resin-bonded fixed partial dentures for single tooth replacement in elderly patients.

OBJECTIVE: To evaluate the clinical performance of cantilevered resin-bonded fixed partial dentures (CRBFPDs) in single tooth replacement in elderly patients at Qingdao Stomatological Hospital. METHODS: In total, 186 CRBFPDs in 153 patients were made from cobalt-chrome alloy. Panavia F 2.0 was used as a luting agent after air-abrasion. Restoration were evaluated at 3-month intervals with regard to function, esthetics, and possible complications. RESULTS: CRBFPDs were evaluated after intervals of 12 to 40 months. The average clinical service time (i.e., length of time in situ at examination, including re-cementation after debonding) was 26.2 ± 13.6 months. Among these CRBFPDs, 87 (46.8%) were bridges in the maxilla, while 99 (53.2%) were bridges in the mandible. Most CRBFPDs (184, 98.9%) survived throughout the study period, while two (1.1%) were regarded as failed. The majority of debonded bridges had been used to replace the maxillary central incisor (60%). CONCLUSION: Our findings confirm the successful clinical performance of CRBFPDs with tooth preparation designs involving mesial and distal vertical grooves in elderly patients.

COVID-19 in Children: Clinical Characteristics and Follow-Up Study.

Since December 2019, the coronavirus disease 2019 (COVID-19) has spread globally. But the clinical symptoms and detailed follow-up of children with COVID-19 infection are lacking. Here, we conducted a retrospective study including children with confirmed COVID-19. We recorded patients' epidemiological, clinical features, and follow-up data after discharging in order to improve the awareness and treatment of children with COVID-19.

[Construction of ADAM28 shRNA interference vector and its inhibitory effect on human periodontal ligament stem cells].

PURPOSE: To investigate the inhibition of ADAM28 shRNA interfering vector on ADAM28 gene expression in human periodontal ligament stem cells(HPDLSC), and provide experimental evidence for gene therapy against congenital hypoplasia of tooth root(CHTR) disease. METHODS: Four pairs of shRNA specific interfering fragments were designed, synthesized, and connected with pGPU6/GFP/Neo vector. ADAM28 shRNA interfering vector was constructed and identified, and transfected into HPDLSC for 48 h, and then the inhibition efficiency was detected by real-time fluorescence quantitative RT-PCR（qRT-PCR）and Western blot. Statistical significance was assessed by SPSS 21.0 software package. RESULTS: Enzyme digestion and sequencing identification demonstrated that the double strands shRNA was correctly inserted into the expression vector pGPU6/GFP/Neo, and the recombinant interfering vector was successfully constructed and highly transfected into HPDLSC. QRT-PCR and Western blot showed that pGPU6/GFP/Neo-ADAM28-shRNA1-4 had significant inhibition efficiency, and shRNA1 had the highest inhibition efficiency. There were significant differences between ADAM28-shRNA1-4 group and non-transfection group, negative control group, respectively(P<0.05). CONCLUSIONS: ADAM28 shRNA interference vector can effectively inhibit ADAM28 gene expression in HPDLSC.

From Hyper- to Hypoinsulinemia and Diabetes: Effect of KCNH6 on Insulin Secretion.

Glucose-stimulated insulin secretion from islet ß cells is mediated by KATP channels. However, the role of non-KATP K+ channels in insulin secretion is largely unknown. Here, we show that a non-KATP K+ channel, KCNH6, plays a key role in insulin secretion and glucose hemostasis in humans and mice. KCNH6 p.P235L heterozygous mutation co-separated with diabetes in a four-generation pedigree. Kcnh6 knockout (KO) or Kcnh6 p.P235L knockin (KI) mice had a phenotype characterized by changing from hypoglycemia with hyperinsulinemia to hyperglycemia with insulin deficiency. Islets from the young KO mice had increased intracellular calcium concentration and increased insulin secretion. However, islets from the adult KO mice not only had increased intracellular calcium levels but also had remarkable ER stress and apoptosis, associated with loss of ß cell mass and decreased insulin secretion. Therefore, dysfunction of KCNH6 causes overstimulation of insulin secretion in the short term and ß cell failure in the long term.

Association between ambient air pollutants and preterm birth in Ningbo, China: a time-series study.

BACKGROUND: Exposure to air pollutants has been related to preterm birth, but little evidence can be available for PM2.5, O3 and CO in China. This study aimed to investigate the short-term effect of exposure to air pollutants on risk preterm birth during 2014-2016 in Ningbo, China. METHODS: We conducted a time-series study to evaluate the associations between daily preterm birth and major air pollutants (including PM2.5, PM10, SO2, NO2, O3 and CO) in Ningbo during 2014-2016. A General Additive Model extend Poisson regression was used to evaluate the relationship between preterm birth and air pollution with adjustment for time-trend, meteorological factors and day of the week (DOW). We also conducted a subgroup analysis by season and age. RESULTS: In this study, a total of 37,389 birth occurred between 2014 and 2016 from the Electronic Medical Records System of Ningbo Women and Children's Hospital, of which 5428 were verified as preterm birth. The single pollutant model suggested that lag effect of PM2.5, PM10, NO2 reached a peak at day 3 before delivery and day 6 for SO2, and no relationships were observed for O3 and preterm birth. Excess risks (95% confidence intervals) for an increase of IQR of air pollutant concentrations were 4.84 (95% CI: 1.77, 8.00) for PM2.5, 3.56 (95% CI: 0.07, 7.17) for PM10, 3.65 (95% CI: 0.86, 6.51) for SO2, 6.49 (95% CI: 1.86, 11.34) for NO2, - 0.90 (95% CI: -4.76, 3.11) for O3, and 3.36 (95% CI: 0.50, 6.30) for CO. Sensitivity analyses by exclusion of maternal age < 18 or > 35 years did not materially alter our results. CONCLUSIONS: This study indicates that short-term exposure to air pollutants (including PM2.5, PM10, SO2, NO2) are positively associated with risk of preterm birth in Ningbo, China.

Neuroprotective effect of tanshinone IIA against neuropathic pain in diabetic rats through the Nrf2/ARE and NF-κB signaling pathways.

The study aims to investigate whether tanshinone (TSN) IIA affects diabetic neuropathic pain (DNP) via the Nrf2/AR and NF-κB signaling pathways. Rats were randomly assigned into DNP group, TSN group (injected with TSN IIA), TSN + DRB group (injected with TSN IIA and 15 mg/kg Nrf2/ARE inhibitors), TSN + PDTC group (injected with TSN IIA and 60 mg/kg NF-κB inhibitors) or control group. The first four groups were successfully established as DNP models after injection of streptozotocin. The blood glucose level, mechanical withdrawal threshold (MWT), thermal withdrawal latency (TWL), nerve conduction velocity (NCV) and antioxidase level were detected. Transmission electron microscopy and toluidine blue staining were utilized to observe the sciatic nerve. RT-qPCR and western blot were used to measure expression levels of Nrf2/ARE and NF-κB signaling pathway-related genes. Blood glucose, malondialdehyde (MDA) and erythrocyte glutathione peroxidase (GSH-Px) levels as well as expression of Keap1 and NF-κB were increased in the TSN, TSN + DRB and TSN + PDTC groups compared to control group. Furthermore, the MWT, TWL, NVC, and superoxide dismutase (SOD) levels and expression of Nrf2, heme oxygenase 1 (HO-1) and inhibitory kappa B (IκB) decreased in the treatment groups. The TSN + DRB and TSN + PDTC groups showed similar trend when compared with the TSN group, while the opposite trend was observed in the TSN group when compared with the DNP group. Our study demonstrates that TSN IIA alleviates neuropathic pain by activating the Nrf2/ARE signaling pathway and inhibiting the NF-κB signaling pathway in diabetic rats.

Effects of Artesunate on chondrocyte proliferation, apoptosis and autophagy through the PI3K/AKT/mTOR signaling pathway in rat models with rheumatoid arthritis.

BACKGROUND: Rheumatoid arthritis (RA) is a long-term autoimmune disorder that primarily results in warm, swollen, and painful joints. In this study, we investigate the potentially therapeutic role of artesunate (Art) on chondrocyte proliferation, apoptosis and autophagy in rheumatoid arthritis (RA) via the PI3K/AKT/mTOR signaling pathway. METHODS: Rat model of RA was successfully established through subcutaneous injection of emulsion. Positive protein expression rates of PI3K, AKT and mTOR were determined by immunohistochemistry. RA chondrocytes were initially randomized into five different groups. The mRNA expressions of PI3K, AKT, mTOR, Bcl-2, Bcl-xl, LC3-I, LC3-II and Becline-1 were measured by RT-qPCR. Protein expressions of p-PI3K, p-AKT, p-mTOR, Bcl-2, Bcl-xl, Bax, LC3-I, LC3-II and Becline-1 were determined using western blotting. The chondrocytes of rats with RA and normal rats were isolated and cultured in vitro. Chondrocyte proliferation, apoptosis, cell cycle and autophagy were all determined by CCK-8 assay, flow cytometry and transmission electron microscope (TEM). RESULTS: Artesunate alleviated the inflammation and did not produce any form of hepatotoxicity in rats with RA. In addition, Artesunate decreased expressions of PI3K, AKT, mTOR, p-PI3K, p-AKT, p-mTOR Bcl-2 and Bcl-xl and increased Bax, LC3II/LC3I and Becline-1 protein expression. Artesunate also inhibited chondrocyte proliferation and accelerates cell apoptosis and autophagy via suppression of the PI3K/AKT/mTOR signaling pathway. CONCLUSION: Our study demonstrates that Art inhibits chondrocyte proliferation and accelerates apoptosis and autophagy in RA rats through the PI3K/AKT/mTOR signaling pathway.

Long Noncoding RNA LINC01133 Functions as an miR-422a Sponge to Aggravate the Tumorigenesis of Human Osteosarcoma.

Long noncoding RNAs (lncRNAs) have been verified to participate in various types of malignant tumors, including osteosarcoma (OS), which is the most common primary bone tumor with outstanding morbidity. Although an increasing number of lncRNAs have been reported to mediate the occurrence of OS, the potential mechanisms are still unclear. This study intends to uncover the mechanism by which lncRNA LINC01133 functions as an miRNA sponge to mediate OS tumorigenicity. In this study, we found that the expression level of LINC01133 was statistically upregulated in OS tumor tissue and cell lines compared to noncancerous tissues and a normal human osteoplastic cell line. LINC01133 silencing could also observably suppress the proliferation, migration, and invasion of OS cells (HOS and U2-OS). Bioinformatics analysis predicted that LINC01133 specifically targeted miR-422a, which was validated by dual-luciferase reporter assay. Furthermore, functional experiments revealed that miR-422a played a tumor-suppressive role in OS progression and could effectively reverse the function of LINC01133. In summary, our study discovered that lncRNA LINC01133 aggravates the proliferation, migration, and invasion of OS by sponging miR-422a, which provides a novel insight in the tumorigenesis of OS.

Effect of 2.8mm clear corneal incisions in phacoemulsification on surgically induced corneal higher-order aberrations / 国际眼科杂志(Guoji Yanke Zazhi)

AIM:To compare the changes of surgically induced corneal higher order aberrations after phacoemulsification with 2.8mm clear corneal incisions at different sites.METHODS:The clinical data of 100 cases (100 eyes) of patients with cataract treated by phacoemulsification with 2.8mm clear corneal incision in our hospital from March 2015 to April 2016 were analyzed retrospectively.According to the site of incision,they were divided into Group A (temporal clear corneal incision,n =55) and Group B (upper clear corneal incision,n=45).Changes of the best corrected visual acuity (BCVA),surgically induced astigmatism (SIA) and corneal topography were compared between the two groups before surgery,at 1d,1wk,1 and 3mo after surgery.The corneal wavefront aberrations were measured by wavefront aberration analyzer,and the changes of higher-order aberrations in corneal 6mm range were recorded.RESULTS:The BCVA of two groups decreased at 1d,1wk,1 and 3mo after surgery (P＜0.05),and the BCVA of Group A at 1d,1wk,and 1mo after surgery was lower than that of Group B (P＜0.05).SIA of the two groups decreased at 1wk,1 and 3mo after surgery (P＜0.05),and the SIA of Group A at different time points after surgery were lower than those of Group B (P＜0.05).The surface asymmetry index (SAI) and the surface rule index (SRI) of the two groups increased at 1 d after surgery,and were gradually decreased at 1wk,1 and 3mo after surgery.The SRI and SAI in Group A were lower than those in Group B at 1d and 1wk after surgery (P＜ 0.05).The total corneal higher-order aberrations (tHOAs) and four-order spherical aberration (SA)showed significant differences between the two groups at 3mo after surgery (P＜0.05).CONCLUSION:The application of 2.8mm temporal clear corneal incision in phacoemulsification can promote the recovery of visual acuity,reduce the effect of surgery on corneal shape,and reduce corneal higher-order aberrations.

A three-step programmed method for the identification of causative gene mutations of maturity onset diabetes of the young (MODY).

To establish a three-step programmed method to find gene mutations related to maturity onset diabetes of the young (MODY). Target region capture and next-generation sequencing (NGS) were performed using customized oligonucleotide probes designed to capture suspected genes for MODY in 11 probands with clinically diagnosed MODY. The suspected associations of certain genes with MODY were then confirmed by Sanger sequencing in the probands and their family members. Finally, to validate variants of one of the genes of interest (glucokinase, GCK) as pathogenic mutations, protein function editing by the variant genes was assessed. In the target region capture and NGS phase, a total of nine variants of seven genes (GCK, WFS1, SLC19A2, SH2B1, SERPINB4, RFX6, and GATA6) were identified in eight probands. Two heterozygous GCK mutations located on the same allele (p.Leu77Arg and p.Val101Met) were identified in a MODY family. Sanger sequencing was used to confirm the variants identified by NGS to be present in probands and their diabetic family members, but not in non-diabetic family members. Finally, enzyme kinetic and thermal stability analyses revealed that the p.Leu77Arg mutation or the p.Leu77Arg mutation in combination with the p.Val101Met mutation inactivates GCK function and stability, while mutation of p.Val101Met alone does not. The p.Leu77Arg but not p.Val101Met GCK mutation is therefore considered a pathogenic mutation associated with MODY. Genetic screening coupled with gene-editing protein function testing is an effective and reliable method by which causative gene mutations of MODY can be identified.

HERG Protein Plays a Role in Moxifloxacin-Induced Hypoglycemia.

The purpose of this study was to investigate the effect of moxifloxacin on HERG channel protein and glucose metabolism. HERG expression was investigated using immunohistochemistry. The whole-cell patch clamp method was used to examine the effect of moxifloxacin on HERG channel currents. A glucose tolerance test was used to analyze the effects of moxifloxacin on blood glucose and insulin concentrations in mice. Results show that HERG protein was expressed in human pancreatic ß-cells. Moxifloxacin inhibited HERG time-dependent and tail currents in HEK293 cells in a concentration-dependent manner. The IC50 of moxifloxacin inhibition was 36.65 µmol/L. Moxifloxacin (200 mg/kg) reduced blood glucose levels and increased insulin secretion in wild-type mice at 60 min after the start of the glucose tolerance test. In contrast, moxifloxacin did not significantly alter blood glucose and insulin levels in HERG knockout mice. Serum glucose levels increased and insulin concentrations decreased in HERG knockout mice when compared to wild-type mice. The moxifloxacin-induced decrease in blood glucose and increase in insulin secretion occurred via the HERG protein; thus, HERG protein plays a role in insulin secretion.

Application of vacuum assisted venous drainage in heart surgeries for newborns.

OBJECTIVE: To explore the role of cardiopulmonary bypass (CPB) with vacuum assisted venous drainage(VAVD)in the management of newborns with congenital heart diseases. METHODS: Total 15 newborns with congenital heart diseases (11 males and 4 females)underwent heart operations. Their age ranged from 2 days to 28 days [mean:(15.67 ± 2.22)days], and their body weight from 2.3 kg to 4.8 kg [mean: (3.75 ± 0.19)kg]. Sternal median incision was made to establish CPB,during which VAVD was applied for all the newborns. RESULTS: In these 15 newborns,the mean CPB time was from 50 minutes to 343 minutes [mean:(170.3 ± 26.6)minutes], and the mean aortic clamping time ranged from 20 minutes to 172 minutes [mean:(85.8 ± 14.6)minutes]. No macroscopic hematuria, inadequate drainage, or cannulation vena cava difficulty was observed during the procedures. All the newborns were successfully weaned from the machine. No neurological complication due to micro air embolus caused by negative pressure was noted. No vena cava infarction, thrombosis, or other complication was reported after the surgery, although one patient died after the surgery and another patient was discharged upon its family's own decision. CONCLUSIONS: VAVD is a safe, simple, and cost-effective technique. Appropriate negative pressure can the resistance during thinner venous intubation and thus speed up blood drainage,provide adequate perfusion flow,and reduce the pre-filling volume.