Performance Evaluation of the uMI Panorama PET/CT System in Accordance with the National Electrical Manufacturers Association NU 2-2018 Standard.

The uMI Panorama is a novel PET/CT system using silicon photomultiplier and application-specific integrated circuit technologies and providing exceptional spatial and time-of-flight (TOF) resolutions. The objective of this study was to assess the physical performance of the uMI Panorama in accordance with the National Electrical Manufacturers Association (NEMA) NU 2-2018 standard. Methods: Spatial resolution, sensitivity, count rate performance, accuracy, image quality, and TOF resolution were evaluated in accordance with the guidelines outlined in the NEMA NU 2-2018 standard. Energy resolution was determined using the same dataset acquired for the count rate performance evaluation. Images from a Hoffman brain phantom, a mini-Derenzo phantom, and 3 patient studies were evaluated to demonstrate system performance. Results: The transaxial spatial resolution at full width at half maximum was measured as 2.88 mm with a 1-cm offset from the center axial field of view. The sensitivity at the center axial field of view was 20.1 kcps/MBq. At an activity concentration of 73.0 kBq/mL, the peak noise-equivalent count rate (NECR) reached 576 kcps with a scatter fraction of approximately 33.2%. For activity concentrations at or below the peak NECR, the maximum relative count rate error among all slices remained consistently below 3%. When assessed using the NEMA image quality phantom, overall image contrast recovery ranged from 63.2% to 88.4%, whereas background variability ranged from 4.2% to 1.1%. TOF resolution was 189 ps at 5.3 kBq/mL and was consistently lower than 200 ps for activity concentrations at or below the peak NECR. The patient studies demonstrated that scans at 2 min/bed produced images characterized by low noise and high contrast. Clear delineation of nuclei, spinal cords, and other substructures of the brain was observed in the brain PET images. Conclusion: uMI Panorama, the world's first commercial PET system with sub-200-ps TOF resolution, demonstrated fine spatial and fast TOF resolutions, robust count rate performance, and high quantification accuracy across a wide range of activity levels. This advanced technology offers enhanced diagnostic capability for detecting small and low-contrast lesions while showing promising potential under high-count-rate imaging scenarios.

DZIP1 expressed in fibroblasts and tumor cells may affect immunosuppression and metastatic potential in gastric cancer.

The tumor microenvironment (TME) contains complex components, of which the most well-known one is the tumor-associated fibroblast (CAF) that participates in the development and progression of tumors. A high abundance of CAFs implies that tumor stroma is also abundant and often predicts a poor prognosis, especially in terms of immunotherapeutic resistance. In this study, DAZ interacting zinc finger protein 1 (DZIP1) was identified to be upregulated in CAFs and malignant epithelial cells based on single-cell sequencing. Furthermore, results from The Cancer Genome Atlas database showed that this gene was highly positively associated with the mesenchymal phenotype in gastric cancer (GC). In addition, molecular experiments verified that DZIP1 directly promoted the proliferation of CAFs and enhanced the epithelial-mesenchymal transition (EMT) of GC cells to drive angiogenesis. Also, the upregulated DZIP1 in GC cells was found to directly promote invasion and metastasis. Finally, multiplex immunofluorescence and immunohistochemistry showed that DZIP1 was correlated with the immunosuppressive microenvironment of GC and resulted in a poor response to immunotherapy. Overall, our findings suggest that DZIP1 is expressed in both tumor parenchyma and mesenchyme and that it is involved in shaping the immunosuppressive microenvironment and inducing EMT by participating in tumor-stromal signaling crosstalk.

Neuroprotective Effect of Abelmoschus manihot Flower Extracts against the H2O2-Induced Cytotoxicity, Oxidative Stress and Inflammation in PC12 Cells.

The progression of neurodegenerative diseases is associated with oxidative stress and inflammatory responses. Abelmoschus manihot L. flower (AMf) has been shown to possess excellent antioxidant and anti-inflammatory activities. This study investigated the protective effect of ethanolic extract (AME), water extract (AMW) and supercritical extract (AMS) of AMf on PC12 neuronal cells under hydrogen peroxide (H2O2) stimulation. This study also explored the molecular mechanism underlying the protective effect of AME, which was the best among the three extracts. The experimental results showed that even at a concentration of 500 µg/mL, neither AME nor AMW showed toxic effects on PC12 cells, while AMS caused about 10% cell death. AME has the most protective effect on apoptosis of PC12 cells stimulated with 0.5 mM H2O2. This is evident by the finding when PC12 cells were treated with 500 µg/mL AME; the viability was restored from 58.7% to 80.6% in the Treatment mode (p < 0.001) and from 59.1% to 98.1% in the Prevention mode (p < 0.001). Under the stimulation of H2O2, AME significantly up-regulated the expression of antioxidant enzymes, such as catalase, glutathione peroxidase and superoxide dismutase; promoted the production of the intracellular antioxidant; reduced glutathione; and reduced ROS generation in PC12 cells. When the acute inflammation was induced under the H2O2 stimulation, AME significantly down-regulated the pro-inflammatory cytokines and mediators (e.g., TNF-α, IL-1ß, IL-6, COX-2 and iNOS). AME pretreatment could also greatly promote the production of nucleotide excision repair (NER)-related proteins, which were down-regulated by H2O2. This finding indicates that AME could repair DNA damage caused by oxidative stress. Results from this study demonstrate that AME has the potential to delay the onset and progression of oxidative stress-induced neurodegenerative diseases.

Effects of Abelmoschus manihot Flower Extract on Enhancing Sexual Arousal and Reproductive Performance in Zebrafish.

The flower of Abelmoschus manihot L. is mainly used for the treatment of chronic kidney diseases, and has been reported to have bioactivities such as antioxidant, anti-inflammatory, antiviral, and antidepressant activities. This study used wild-type adult zebrafish as an animal model to elucidate the potential bioactivity of A. manihot flower ethanol extract (AME) in enhancing their sexual and reproductive functions. Zebrafish were fed AME twice a day at doses of 0.2%, 1%, and 10% for 28 days, and were then given the normal feed for an additional 14 days. The hormone 17-ß estradiol was used as the positive control. Sexual behavioral parameters such as the number of times males chased female fish, the production of fertilized eggs, and the hatching rate of the fertilized eggs were recorded at days 0.33, 7, 14, 21, 28, and 42. The expression levels of sex-related genes­including lhcgr, ar, cyp19a1a, and cyp19a1b­were also examined. The results showed that the chasing number, fertilized egg production, and hatching rate were all increased with the increase in the AME treatment dose and treatment time. After feeding with 1% and 10% AME for 28 days, the chasing number in the treated group as compared to the control group increased by 1.52 times and 1.64 times, respectively; the yield of fertilized eggs increased by 1.59 times and 2.31 times, respectively; and the hatching rate increased by 1.26 times and 1.69 times, respectively. All three parameters exhibited strong linear correlations with one another (p < 0.001). The expression of all four genes was also upregulated with increasing AME dose and treatment duration. When feeding with 0.2%, 1%, and 10% AME for 28 days, the four sex-related genes were upregulated at ranges of 1.79−2.08-fold, 2.74−3.73-fold, and 3.30−4.66-fold, respectively. Furthermore, the effect of AME was persistent, as the promotion effect continued after the treatment was stopped for at least two weeks. The present findings suggest that AME can enhance the endocrine system and may improve libido and reproductive performance in zebrafish.

Fabrication of bacterial cellulose with TiO2-ZnO nanocomposites as a multifunctional membrane for water remediation.

Superhydrophilic/underwater superoleophobic (SUS) membrane technology has attracted extensive attention for water purification. However, the fabrication of multifunctional membranes to satisfy the complex wastewater treatment is still a big challenge. In this work, bacterial cellulose (BC) based multifunctional SUS membranes were designed for water purification. Membranes were prepared by blending BC nanofibers with TiO2 nanoparticles (NPs), and further modified by the in situ growth of ZnO-NPs. The composite membranes showed oil/water (o/w) separation under a small driving pressure (0.2-0.3 bar) with a flux rate of 8232.81 ± 212 L m-2h-1 and with a high separation efficiency (>99.9%). Membranes could also separate oil-in-water emulsion with a separation flux of 1498 ± 74 L m-2h-1 and with high efficiency (99.25%). Moreover, the composite membrane exhibited photocatalytic activity under visible light with a high efficiency (>92%). The composite membranes were also investigated for antibacterial activity against Gram-positive and Gram-negative bacterial strains. This work may inspire the fabrication of next-generation multifunctional membranes for wastewater treatment, particularly oily wastewater, dyes and microbial contaminated water.

Bacterial cellulose and its potential for biomedical applications.

Bacterial cellulose (BC) is an important polysaccharide synthesized by some bacterial species under specific culture conditions, which presents several remarkable features such as microporosity, high water holding capacity, good mechanical properties and good biocompatibility, making it a potential biomaterial for medical applications. Since its discovery, BC has been used for wound dressing, drug delivery, artificial blood vessels, bone tissue engineering, and so forth. Additionally, BC can be simply manipulated to form its derivatives or composites with enhanced physicochemical and functional properties. Several polymers, carbon-based nanomaterials, and metal nanoparticles (NPs) have been introduced into BC by ex situ and in situ methods to design hybrid materials with enhanced functional properties. This review provides comprehensive knowledge and highlights recent advances in BC production strategies, its structural features, various in situ and ex situ modification techniques, and its potential for biomedical applications.

Cellulose-based special wetting materials for oil/water separation: A review.

Oil spill accidents and oily wastewater discharged by petrochemical industries have severely wasted water resources and damaged the environment. The use of special wetting materials to separate oil and water is efficient and environment-friendly. Cellulose is the most abundant renewable resource and has natural advantages in removing pollutants from oily wastewater. The application and modification of cellulose as special wetting materials have attracted considerable research attention. Therefore, we summarized cellulose-based superlipophilic/superhydrophobic and superhydrophilic/superoleophobic materials exhibiting special wetting properties for oil/water separation. The treatment mechanism, preparation technology, treatment effect, and representative projects of oil-bearing wastewater are discussed. Moreover, cellulose-based intelligent-responsive materials for application to oil/water separation and the removal of other pollutants from oily wastewater have also been summarized. The prospects and potential challenges of all the materials have been highlighted.

Adlay Testa (Coix lachryma-jobi L. var. Ma-yuen Stapf.) Ethanolic Extract and Its Active Components Exert Anti-Proliferative Effects on Endometrial Cancer Cells via Cell Cycle Arrest.

Endometrial cancer is the most common malignant tumors of gynecologic neoplasms in Western society. In recent years, the incidence of endometrial cancer has increased, and it has become the third most common female gynecological cancer (after ovarian and cervical cancer) in Taiwan. Adlay (Coix lachryma-jobi L. var. Ma-yuen Stapf.) has been demonstrated to have bioactive polyphenols, flavonoids, phytosterols, and essential nutrients for health benefits, including anticancer effects in humans. However, little is known about the effect of adlay seeds on endometrial cancer. Our study aimed to investigate the potential growth inhibitory effects of several adlay seed fractions, including ethyl acetate (ATE-EA) and its bioactive constituents, separately on endometrial cancer cells-HEC-1A (phosphatase and tensin homolog-positive) and RL95-2 (phosphatase and tensin homolog-negative)-and identify related active ingredients. In addition, the potential active fractions and the phytochemical compounds were elucidated. The results demonstrate superior activity of ATE-EA with significant in vitro cell proliferation inhibitory capacity, particularly its C.D.E.F-subfraction. Moreover, HPLC- and GC/FID-based quantification of ATE-EA subfractions showed that phenolic compounds (caffeic acid, protocatechuic acid, and p-hydroxybenzaldehyde), flavonoids, steroids, and fatty acid compounds exert anti-proliferative effects in the cell model. Finally, it was shown that cell growth and cell cycle arrest most significantly occurred in the in G1 or G2/M phase under ATE-EA treatment. Collectively, our results demonstrate an antiproliferative effect of ATE-EA on endometrial cancer cells that suggest a positive health outcome for women from consumption of these compounds.

Akt is a critical node of acute myocardial insulin resistance and cardiac dysfunction after cardiopulmonary bypass.

AIMS: Acute myocardial insulin resistance is an independent risk factor for patients who undergo cardiac surgery with cardiopulmonary bypass (CPB). However, the underlying mechanism of insulin resistance during CPB has not been fully investigated. MATERIALS AND METHODS: To explore the role of myocardial insulin resistance on the cardiac function and its underlying mechanism, CPB operation and pharmacological intervention were applied in mini pigs, and myocardial insulin signaling, glucose uptake, ATP production and cardiac function were examined. KEY FINDINGS: Our data showed that CPB elicited not only hyperglycemia and hyperinsulinemia, but also inactivated Akt, and impaired the transposition of membrane glucose transporter-4 (GLUT-4), reduced glucose uptake and ATP production in the myocardium as well, which in turn was accompanied with cardiac dysfunction. Meanwhile, linear correlations were established among reduced myocardial glucose uptake, ATP production, and depressed cardiac systolic or diastolic function. Reactivation of Akt by SC79, an Akt agonist, partially alleviated myocardial insulin resistance and restored post CPB cardiac function via augmenting myocardial glucose uptake and ATP production. SIGNIFICANCE: These findings revealed that acute myocardial insulin resistance due to inactivation of Akt played a key role in cardiac dysfunction post CPB via suppressing glucose metabolism related energy supply.

Activation of AMPK alleviates cardiopulmonary bypass-induced cardiac injury via ameliorating acute cardiac glucose metabolic disorder.

Recent years, studies have demonstrated that hyperglycemia is one of the main manifestations after cardiac surgeries, which contributes to myocardial injuries and increases the chance of subsequent complications and mortality in such patients. However, strategies targeting at glucose metabolic disorder after cardiac surgeries to attenuate myocardial injuries are inadequately studied. In this study, a rat model of cardiopulmonary bypass (CPB) was applied to investigate the role of Adenosine 5'-monophosphate-activated protein kinase (AMPK) in modulating myocardial glucose metabolic-induced cardiac injuries after cardiac surgery. The results revealed that CPB elicited significant cardiac dysfunction, and pronouncedly elevated the markers of myocardial injuries including serum creatine kinase MB and cardiac troponin I. Additionally, blunted myocardial glucose uptake after CPB was associated with decreased membrane glucose transporter 4 (GLUT4) content. However, pretreatment of AMPK agonist 5-aminoimidazole-4-carboxamide1-ß-D-ribofuranoside (AICAR) at the beginning of CPB activated AMPK, enhanced phosphorylation of Akt substrate 160 (AS160), and increased myocardial membrane content of GLUT4. Meanwhile, improved myocardial glucose uptake and more importantly alleviated cardiac injury were also observed after CPB pretreated with AICAR. Moreover, the application of a mutant form of AS160 (AS160-4P) abolished the beneficial effect of AICAR, as evidenced by impaired cardiac glucose uptake, reduced myocardial membrane GLUT-4 translocation, increased cardiac injury markers, and deterioration of cardiac function after CPB. In conclusion, it was suggested in this study that preactivation of AMPK by AICAR improved myocardial glucose uptake by promoting AS160 dependent myocardial membrane GLUT-4 translocation, which ultimately provided a potent cardioprotective effect.

Induction of angiogenesis by controlled delivery of vascular endothelial growth factor using nanoparticles.

AIMS: The study reports the feasibility and efficiency of vascular endothelial growth factor (VEGF) delivery using nanoparticles synthesized from glycidyl methacrylated dextran (Dex-GMA) and gelatin for therapeutic angiogenesis. METHODS: The nanoparticles were prepared using phase separation method, and the drug release profile was determined by ELISA study. The bioactivity of VEGF-incorporated nanoparticles (VEGF-NPs) were determined using tube formation assay. A rabbit hind limb ischemia model was employed to evaluate the in vivo therapeutic effect. Blood perfusion was measured by single-photon emission computed tomography (SPECT). Vessel formation was evaluated by contrast angiography and immunohistochemistry. RESULTS: The nanoparticles synthesized were spherical in shape with evenly distributed size of about 130 ± 3.5 nm. The VEGF encapsulated was released in a biphase manner, with the majority of 69% released over 1-12 days. Tube formation assays showed increased tubular structures by VEGF-NP compared with empty nanoparticles and no treatment. Both free VEGF and VEGF-NP significantly increased blood perfusion compared with empty nanoparticles (both P < 0.001), but it was much higher in VEGF-NP-treated limbs (P < 0.001). Contrast angiography and immunohistological analysis also revealed more significant collateral artery formation and higher capillary density in VEGF-NP-treated limbs. CONCLUSIONS: Dex-GMA and gelatin-based nanoparticles could provide sustained release of VEGF and may serve as a new way for angiogenesis.

Impacts of intensive insulin therapy in patients undergoing heart valve replacement.

BACKGROUND AND AIMS: Cardiac surgery with cardioplegic cardiac arrest and cardiopulmonary bypass (CPB) is associated with severe stress response, systemic inflammatory response, and injury. This study was designed to investigate the effects of intensive insulin therapy on patients undergoing valve replacement with CPB. METHODS: One hundred nondiabetic inpatients undergoing valve replacement were randomly assigned to a control group or an intensive insulin therapy (IT) group. Plasma cytokine and cardiac troponin I (cTnI) levels were monitored perioperatively. RESULTS: Compared with the control group, the IT group had smaller increases in plasma concentrations of tumor necrosis factor α, interleukin 1ß (IL-1ß), IL-6, and cTnI, and had a more pronounced increase in IL-10 levels after the initiation of CPB. After surgery, the required inotropes were reduced in the IT group. In the IT group, the time of artificial ventilation and the postoperative length of stay in the hospital were markedly shortened; however, there were no significant differences between the IT and control groups in mortality and the rate of nosocomial infections of deep sternal wounds. CONCLUSIONS: IT can significantly attenuate the systemic inflammatory response and improve a damaged cardiac function, but it does not reduce the in-hospital mortality rate.

Surgical treatment of giant coronary artery aneurysm secondary to Kawasaki disease.

AIM: To investigate the clinical features and surgical management of giant coronary artery aneurysm during end-stage Kawasaki disease. METHODS: From May 2006 to October 2007, 5 patients, 2 to 57 years old, presented with giant coronary artery aneurysm and underwent surgical correction. The coronary aneurysm diameters were 1.5 to 2.5 cm. The coronary aneurysm lesion sites included the right main coronary artery in 1 case, the left main coronary artery in 2 cases, and both the left and right coronary arteries in 2 cases. Preoperative electrocardiogram revealed altered S-T segments in 5 cases and reduced ejection fraction values in 3 cases, resulting in 1 emergency admission for congestive heart failure. Surgical treatments included thromboendarterectomy, thrombectomy, and aneurysmal reconstruction under the orthophoria of extracorporeal circulation. RESULTS: There were no operative deaths. All patients recovered and received dopamine 2 to 4 microg/min per kg and nitroglycerine 0.3 to 0.5 microg/min per kg. Time spent by patients in intensive care was uneventful. Following surgery, 4 patients showed ischemic improvement of the S-T segment on electrocardiograms, and 4 patients presented with increased ejection fraction, according to cardiac ultrasound inspection. The improvement of ejection fraction value was not significant in only 1 case. CONCLUSION: Surgery is necessary for stage-3 Kawasaki disease patients that have giant coronary artery aneurysm complications. Surgical treatment includes thromboendarterectomy, thrombus clearing, aneurysmal reconstruction, and coronary artery bypass grafting, followed by postoperative anticoagulation and immunotherapy. Myocardial ischemia and cardiac function can be greatly improved through surgery.

Age-dependent mobilization of circulating endothelial progenitor cells in infants and young children undergoing cardiac surgery with cardiopulmonary bypass.

This study was designed to find the effects of age on circulating endothelial progenitor cells (EPCs) and their mobilization in infants and young children following surgical correction of congenital heart defects. In 60 consecutive infants and young children (1month to 3years old) undergoing repair of atrial/ventricular septal defect, the numbers of EPCs and plasma levels of IL-6, -8, -10, TNF-alpha, VEGF and G-CSF were determined preoperatively, at the end of cardiopulmonary bypass (CPB), as well as 6, 12, 24, 48, 72 and 96h following surgery. Preoperative EPCs were reduced with increased age, similar to changes in plasma VEGF and G-CSF levels. Rapid mobilizations of EPCs and plasma VEGF, G-CSF were induced by cardiac surgery with CPB in all infants and young children, and the increased volumes of EPCs, VEGF and G-CSF decreased with age decreasing. The increased volumes of IL-6, -8, -10 and TNF-alpha were similar in different age groups. However, mobilization of EPCs, plasma VEGF and G-CSF were limited in infants <6months old, which did not correlate with change in inflammatory IL activation. Preoperative EPCs and plasma levels of VEGF and G-CSF were reduced with increasing age in infants and young children. Although a significant increase in EPCs and release of cytochemokines were observed in infants undergoing CPB, the mobilization of EPCs of the infants <6months old are limited.

[Construction of an acellular porcine aortic valve].

OBJECTIVE: To prepare a porcine aortic valve (PAV) free of the cellular components. METHODS: The cellular components of porcine PAV were completely removed using trypsin and Triton X-100, and the acellular PAV was examined microscopically with HE staining with its physical and chemical properties assessed. Transmission electron microscopy was used to observe the integrity of the collagen and elastin and the DNA contents in the PAV was detected to confirm the total removal of the cellular components. With the fresh PAV as the control, small pieces of the acellular PAV were implanted into the subcutaneous tissues of 4 rabbits, and 4 weeks after the implantation, the implants were harvested for microscopic observation. RESULTS: The cellular components were effectively removed from the cusps and roots of the PAV by trypsin and TritonX-100, with marked soluble protein loss [(0.24-/+0.04)% vs (0.48-/+0.12)%] and significantly increased water content [(92.2-/+1.5)% vs (89.2-/+1.6)%]. The acellular PAV still maintained good fibrous scaffold structure and the shrinkage temperature and tension at fracture underwent no significantly changes [(67.9-/+1.0) degrees celsius; vs (68.8-/+0.8) degrees celsius; and (489.3-/+19.0) g/mm2 vs (540.7-/+19.5) g/mm2, respectively]. The PAVs implanted in rabbits showed only mild tissue reaction with a few infiltrating neutrophils, lymphocytes and plasmocytes observed 4 weeks later. The accelular PAV caused obviously milder inflammatory reactions than fresh PAV. CONCLUSIONS: The acellular PAV prepared by treatment with trypsin and Triton X-100 retains good fibrous scaffold structure and mechanical strength with low antigenicity.

Effects of insulin therapy on inflammatory mediators in infants undergoing cardiac surgery with cardiopulmonary bypass.

To determine whether insulin administration modulates the systemic inflammatory response in infants undergoing cardiac surgery with cardiopulmonary bypass, 60 infants undergoing cardiopulmonary bypass were randomly assigned into a routine therapy group or to an intensive insulin therapy group with 30 infants in each group. Plasma IL-1beta, IL-6, IL-10, and TNF-alpha levels were determined before anesthesia, at the initiation of cardiopulmonary bypass, and at 0, 6, 12, 24, and 48 h after cardiopulmonary bypass. Nuclear factor-kappaBp65 expression and IkappaB expression in peripheral blood mononuclear cells were also measured by Western blot analysis. TNF-alpha, IL-1beta, IL-6, and IL-10 levels were all elevated after the initiation of cardiopulmonary bypass. However, TNF-alpha, IL-1beta, and IL-6 levels were significantly attenuated in the intensive insulin therapy group compared to those in the routine therapy group after initiation of cardiopulmonary bypass (p<0.05 or <0.01). Meanwhile, plasma IL-10 levels were significantly higher in the intensive insulin therapy group than in the routine therapy group after initiation of cardiopulmonary bypass (p<0.05 or <0.01). Accordingly, Nuclear factor-kappaBp65 expression and IkappaB expression were significantly increased after initiation of cardiopulmonary bypass in both groups (p<0.05 or <0.01). The expression of Nuclear factor-kappaBp65, which induces the transcription of pro-inflammatory cytokines was significantly attenuated in the intensive insulin therapy group (p<0.05 or <0.01). Meanwhile, the expression of IkappaB, an inhibitor of NF-kappaB, was significantly higher in the intensive insulin therapy group (p<0.05 or <0.01). These results suggested that intensive insulin therapy may attenuate the systemic inflammatory response in infants undergoing cardiopulmonary bypass.

No infection with porcine endogenous retrovirus in recipients of acellular porcine aortic valves: a two-year study.

BACKGROUND: Engineered tissue heart valves may become a promising therapeutics for heart valve disease. Compared with synthetic materials, acellular porcine scaffolds are considered as suitable matrices for tissue-engineered heart valves for the mechanical and structural properties of native tissue. Whether acellular porcine scaffolds can cause infection in recipients with porcine endogenous retrovirus (PERV) is critical for evaluating the safety of transplantation of tissue-engineered heart valves based on acellular porcine scaffolds. This study was completed to evaluate the risk of PERV transmission for application of acellular porcine aortic valves (PAVs). METHODS: Native aortic valves obtained from Chinese pigs of different species were acellularized by our modified detergent-enzymatic acellularization procedure. Polymerase chain reaction and reverse transcriptase polymerase chain reaction for pol sequences were used to detect PERV infection. In vitro, ovine endothelial cells (ECs) were inoculated and cocultured with supernatants of porcine aortic endothelial cells (PAECs) and acellualr PAVs, respectively. On 7th day, DNA and RNA of ovine ECs were isolated and tested for PERV. In vivo, acellular PAVs were implanted in the descending thoracic aorta in 40 sheep. Blood samples from the sheep and implanted acellular PAVs were collected 24 months after operation and tested for PERV. RESULTS: All cells were removed from the PAVs. Acellularized PAVs were repopulated by autologous cells of the host 24 months after implantation. PERV was detected in all native PAVs, porcine blood samples, acellularized PAVs and ovine ECs inoculated with supernatants of PAECs; no PERV was detected in ovine ECs cocultured with acellularized PAVs, ovine blood samples, and implanted acellular PAVs. CONCLUSIONS: Acellularized PAVs processed by modified detergent-enzymatic acellularization procedure can be used for cardiovascular tissue-engineered grafts as matrix scaffolds without risk of PERV transmission.

[Effects of modified acellularization process on porcine endogenous retroviruses in porcine aorta valves].

OBJECTIVE: to study the effect of modified acellularization process on porcine endogenous retrovirus (PERV) in porcine aorta valves (PAVs). METHODS: Twenty aortic valves of pig were put into 0.1% trypsin solution, hypotonic and hypertonic TritonX-100, DNAse solution, RNAse solution, and Hanks solution in succession so as to remove the cells. The specimens of PAV were to undergo gross observation and microscopy before and after the acellularization procedure. Fracture test was made. Primers specific for the conservative gag gene of PERV were designed PCR and RT-PCR were used to detect the expression of gag. In addition, 20 samples of native PAV were collected. Peripheral mononuclear cells (PBMCs). Were isolated from 20 samples of porcine peripheral blood. Ten dogs underwent acellularized PAV replacement; 3 months later, samples of the dogs' peripheral blood were collected. Porcine kidney cells of the line PK15 were used as positive controls. RESULTS: Microscopy showed that all the cells were removed from the acellularized PAVs. Histological analysis showed that the major structural components were maintained. There was no significant difference in fracture strength between the native and acellularized PAVs (P > 0.05). PCR and RT-PCR showed a PERV 219 bp DNA fragment, 90%-95% homologous with the published PERV gene, in the genomic DNA of all native PAVs, pig PBMCs, and PK15 cells, but not in the acellularized PAVs and dog PBMCs. CONCLUSION: PERV exists in all native PAVs. The modified acellularization process succeeds in removing all the cell component and PERV in the PAVs, thus preventing cross-species transmission of PERV.