[Design of an improved percutaneous transhepatic cholangio drainage tube based on MRCP imaging data].

Objective: Quantified MRCP imaging data was used as a reference for design and preparation of a modified percutaneous transhepatic cholangio drainage (PTCD) tube. Methods: 3.0 T upper abdominal MR and MRCP imaging data of 2 300 patients treated from July 2015 to July 2020 at the Department of Radiology of the Affiliated Cancer Hospital of Zhengzhou University were screened and a total of 381 patients diagnosed with biliary duct structures were identified. Causative etiologies among these patients included pancreatic adenocarcinoma (pancreatic head), cholangiocarcinoma, ampullary carcinoma, as well as intrahepatic and/or extrahepatic bile duct dilation. An improved PTCD tube was designed based on MRCP quantification of left and right hepatic and common hepatic duct length. Results: In the setting of biliary obstruction caused by malignancy, the distance of the left hepatic duct from its origin to the point of left and right hepatic duct confluence was 15.9±3.8 mm, while the distance of the right hepatic duct from its origin to the point of left and right hepatic duct confluence was 12.4±3.2 mm; the length of the bile duct from its origin to the point of left and right hepatic duct confluence was 34.0±8.1 mm. The improved PTCD tube design incorporated an altered length of the drainage orifice. Conclusion: MRCP imaging of the biliary tract is effective for measuring biliary tract length in the setting of pathological dilation. Based on our biliary tract measurements, a modified PTCD tube was designed to more effectively meet drainage requirements and manage biliary obstruction caused by Bismuth-Corlette type Ⅱ and Ⅲ malignancies.

Expression of duck hepatitis A virus type 1 VP3 protein mediated by avian adeno-associated virus and its immunogenicity in ducklings.

The avian adeno-associated virus (AAAV) is a replication-defective nonpathogenic virus that has been proved to be useful as a viral vector in gene delivery. In this study, the feasibility of AAAV for transgenic expression of duck hepatitis A virus (DHAV) VP3 structural protein and its ability to induce protective immunity in ducklings was assessed. The recombinant AAAV (rAAAV-VP3) expressing the VP3 protein was prepared by co-infection of Sf9 cells with recombinant baculovirus (rBac-VP3) containing VP3 gene flanked by inverted terminal repeats (ITRs) of AAAV and the other two recombinant baculovirus expressing AAAV functional and structural genes, respectively. The generation of rAAAV-VP3 was demonstrated by electron microscopy, immunofluorescence assay, and western blot analysis. One day old ducklings were inoculated with rAAAV-VP3 or commercial attenuated vaccine and then challenged with DHAV-1 strain SH two weeks post vaccination. Anti-DHAV-1 antibodies were detected in all vaccinated groups by ELISA, and the titers between the rAAAV-VP3 group and the attenuated vaccine group were not statistically significant. Real time RT-PCR analysis showed that the virus copy numbers in the livers of the PBS control group were significantly higher than that of the rAAAV-VP3 and attenuated vaccine groups. In conclusion, we demonstrated that the VP3 expression mediated by rAAAV in ducklings could induce protective immunity against DHAV challenge, and this could be a candidate vaccine for the control of duck viral hepatitis. Keywords: avian adeno-associated virus; duck hepatitis A virus; VP3 gene; immunogenicity.

Tribological and corrosion performance of the plasma-sprayed conformal ceramic coating on selective laser melted CoCrMo alloy.

Ceramic implants have superior performance due to the excellent wear resistance and biocompatibility. However, the poor machinability limits their applications. Plasma sprayed ceramic coating on the additively manufactured metal substrate not only provides a 3-dimensional conformal implant coating and but also forms a highly wear-resistant surface layer. In this paper, three types of ceramic coatings of Al2O3, ZrO2, and Al2O3-ZrO2 composite have been fabricated by atmosphere plasma spray on the CoCrMo alloy substrate prepared by selective laser melting (SLM). It has been found that the Al2O3-ZrO2 composite coating has better corrosion and wear resistance compared with the ceramic coating (Al2O3, ZrO2) and the CoCrMo substrate. The adhesion strength between the Al2O3-ZrO2 composite coating and the substrate reaches 238 MPa. In addition, the wear and corrosion resistance increase with wear progression for all the fabricated ceramic coatings. The highly dense microstructure, fewer microcracks, and the amorphous phases are deterministic factors responsible for the superior tribological and corrosion performance of the Al2O3-ZrO2 composite coating. The fabrication route has been proved very promising to manufacture high-performance implants with ceramic coating.

Protection against duck hepatitis a virus type 1 conferred by a recombinant avian adeno-associated virus.

The avian adeno-associated virus (AAAV) has been proved to be an efficient gene transfer vector for human gene therapy and vaccine research. In this experiment, an AAAV-based vaccine was evaluated for the development of a vaccine against duck hepatitis a virus type 1 (DHAV-1). The major capsid VP1 gene was amplified and subcloned into pFBGFP containing the inverted terminal repeats of AAAV, and then the recombinant baculovirus rBac-VP1 was generated. The recombinant AAAV expressing the VP1 protein (rAAAV-VP1) was produced by co-infecting Sf9 cells with rBac-VP1 and the other 2 baculoviruses containing AAAV functional genes and structural genes respectively, and confirmed by electron microscopy, Western blotting and immunofluorescence assays. Quantitative real-time PCR revealed that the titer of rAAAV-VP1 was about 9 × 1012 VG/mL. Immunogenicity was studied in ducklings. One day ducklings were injected intramuscularly once with rAAAV-VP1. Serum from rAAAV-VP1-vaccinated ducklings showed a systemic immune response evidenced by VP1-specific enzyme-linked immunosorbent assay and virus neutralization test. Furthermore, all ducklings inoculated with rAAAV-VP1 were protected against DHAV-1 challenge. The data of quantitative real-time RT-PCR from livers of challenged ducklings also showed that the level of virus copies in rAAAV-VP1 group was significantly lower than that of the PBS group. Collectively, these results demonstrate that the AAAV-based vaccine is a potential vaccine candidate for the control of duck viral hepatitis.

Study on the nanosecond transient absorption spectra of hypocrellin A.

In this paper, the nanosecond transient absorption spectra and the fluorescence spectra of Hypocrellin A(HA) are examined in solvents of varying polarity. There are three absorption bands in dilute HA solutions: Ia, IIa are defined as the triplet-triplet absorption of HA, the band IIIa is supposed to be the absorption of the solvent-separated ion pair (SSIP). In more concentrated solutions, only the absorption of SSIP was observed. The effects of solvent polarity on transient absorption spectra and fluorescence spectra of HA and the effect of oxygen on the intensities of the fluorescence of HA are discussed. Then a reasonable mechanism for the photolysis of HA is proposed.

Adipose pyruvate carboxylase: amino acid sequence and domain structure deduced from cDNA sequencing.

The complete amino acid sequence of 3T3-L1 adipocyte pyruvate carboxylase (PC) [pyruvate:carbon-dioxide ligase (ADP-forming), EC 6.4.1.1] has been deduced from sequencing overlapping cDNA clones obtained from an adipocyte cDNA library constructed in the lambda Zap vector. The encoding mRNA for PC promoter contains 4067 nt, including a 3534-nt coding sequence and noncoding regions of 100 and 433 nt at the 5' and 3' ends, respectively. The biotinylated lysine of the encoded PC promoter (1178 amino acids with a calculated M(r) of apocarboxylase = 129,784) is located 35 residues from the COOH-terminal end and, as in most other biotin enzymes, is in the consensus sequence AMKM. The adipocyte PC is closely similar (53% identity) to the yeast enzyme and contains different segments that are homologous with regions from the biotin carboxylase component of Escherichia coli acetyl-CoA carboxylase, the keto acid-binding subunits of Propionibacterium shermanii oxaloacetate transcarboxylase and Klebsiella pneumoniae oxaloacetate decarboxylase, and to the biotin carboxyl-carrier protein of the bacterial biotin enzymes. In addition to the putative mitochondrial targeting signal, functional domains are readily identifiable in the sequence and are in the following order: biotin carboxylase-carboxyltransferase-biotin carboxyl-carrier protein, as proposed for yeast PC.

Biotin holocarboxylase synthetase: purification from rat liver cytosol and some properties.

The purification of biotin holocarboxylase synthetase (EC 6.3.4.10) from rat liver cytosol to a much higher degree of purity than previously reported, is described. The specific enzymatic activity of the final preparation is increased about 7,000 fold over the starting material. The purified preparation elutes from a gel-filtration column in a volume consistent with a molecular size of 100 kDa and examination by SDS-PAGE reveals one major band of M(r) 50 kDa. This suggests that the native synthetase may exist as a dimer of similar weight subunits.

Regulation of pyruvate carboxylase in 3T3-L1 cells.

When 3T3-L1 fibroblasts differentiate to adipocytes, the specific activity of pyruvate carboxylase (PC) increases about 25-fold in parallel with its intracellular protein concentration. The increase in PC protein concentration is accompanied by a 9-10-fold increase in the relative abundance of 4.2 kb PC mRNA measured by Northern-blot analysis using a cDNA probe encoding a segment of the PC gene of 3T3-L1 adipocytes. The effects of cyclic AMP (cAMP) alone and together with insulin on levels of cellular protein, PC activity, PC protein and on the relative abundance of PC mRNA were examined in mature 3T3-L1 adipocytes. Adipocytes exposed to cAMP for 24 h exhibited a 25% decrease in cellular protein and marked decreases in enzyme activity (88%) and PC mRNA abundance (98%) compared with untreated adipocyte controls. After 48 h of exposure to cAMP, PC activity and PC mRNA diminished to levels approaching their detection limits. When exposed to medium containing cAMP plus insulin, adipocyte enzyme activity and PC mRNA declined more slowly during the first 24 h exposure (about 20% decrease) but after 48 h fell to values comparable with those of adipocytes exposed to cAMP alone. Despite these decreases in enzyme activity, the PC protein content of adipocytes treated with cAMP alone or cAMP plus insulin are nearly identical with that of control adipocytes. The inactivation of PC in cAMP-treated adipocytes does not involve loss of the prosthetic group from the holoenzyme. Cross-linking experiments suggest that the spatial arrangement of protomers in inactive PC may differ from that in the active tetrameric enzyme. Data presented suggest that, in addition to inducing inactivation, cAMP may also regulate adipocyte PC by decreasing transcription of the PC gene and/or enhancing the rate of degradation of PC mRNA.

Cold lability of lactate dehydrogenase isoenzymes and the effective preparation of reference material for clinical laboratory use.

To evaluate the storage of samples and enzyme reference materials, and to improve the commutability for inter-laboratory surveillance of activity values of lactate dehydrogenase (LD; EC 1.1.1.27) in clinical laboratory medicine and in animal veterinary medicine, we studied the electrophoretic patterns and cold lability of LD isoenzymes from tissue sources of some common vertebrate species and also from human serum sources. Among many isoenzymes from these sources, only rat LD fractions showed similar electrophoretic patterns to those of human sera, and rat LD-1 fraction was relatively cold-stable. Total LD and isoenzyme LD-1 activities in routine laboratory samples and quality-control sera were measured using eight kinds of commercially available LD assay kit, including lactate and pyruvate substrate systems. Coefficients of variation between these assay kits were markedly reduced when the activities were calculated using the partially purified rat LD-1 fraction as an enzyme reference material, compared with the activities calculated using the factor indicated in each assay kit. In the regression analysis, the intercept and slope were calculated for the regression equations obtained from 12 pairs of these assay kits. The values obtained from a small amount of human serum and control serum samples were within the 95% confidence regions of those from larger amounts of human serum samples by using the present rat LD-1 standard for measuring LD-1 activities with lactate substrate. It was evident that a cold-stable and homogeneous LD isoenzyme as an enzyme reference material might contribute to accurate measurement of activities in heterogeneous samples for inter-laboratory quality-assurance surveys in both human and animal clinical laboratory use.

Relationship between selenium and protein synthesis in cells and subcellular fractions in rat liver.

In order to determine the effect of selenium supplementation on protein synthesis in rat liver, the rate of incorporation of (3H)-leucine into protein by isolated hepatocytes, liver mitochondria and post-mitochondrial supernatant derived from four groups of rats fed diets supplemented with 0, 0.25, 0.35 and 0.40 mg/kg selenium as selenite were investigated. In addition, the alteration in nucleic acid, lipid peroxides and glutathione peroxidase in hepatocytes from the same liver were also examined. By the end of feeding, the rates of amino acid incorporation, ribonucleic acid contents and glutathione peroxidase activities were significantly higher in hepatocytes from the 0.25, 0.35 and 0.40 mg/kg Se diet groups compared with the unsupplemented group. With increasing selenium supplementation, the increments of amino acid incorporation activity, RNA content as well as glutathione peroxidase all together plateau at approximately 0.25 mg/kg Se level of selenium supplementation. The rates of amino acid incorporation into protein in liver mitochondria and post-mitochondrial supernatant and RNA/DNA ratio in liver homogenates derived from the 0.25 mg/kg Se group were increased as compared to that from the unsupplemented group; concomitantly the increment of glutathione peroxidase activities and the reduction of malondialdehyde in liver were also found in the 0.25 mg/kg Se group. The results suggested that selenium supplementation at a 0.25 mg/kg level was sufficient to stimulate amino acid incorporation into protein in hepatocytes, mitochondria and post-mitochondrial supernatant from rat liver, and the increases in incorporation were also consistent with increments of glutathione peroxidase activities and decrease of malondialdehyde.