Application of DynaCT angiographic reconstruction in balloon pulmonary angioplasty.

OBJECTIVES: To investigate the feasibility and accuracy of balloon pulmonary angioplasty (BPA) using DynaCT angiographic reconstruction guidance. METHODS: Thirty-four BPAs (23 CTEPH patients) targeting 175 pulmonary arteries were included. Eleven BPAs (2D group) were guided by DSA two-dimensional angiography. Another twenty-three BPAs (3D group) were guided using DynaCT angiographic reconstruction. The volume rendering (VR) method was used to obtain a three-dimensional image of the blood vessels. This image was used as a reference to continue BPA treatment under the guidance of vascular three-dimensional reconstruction technology. Procedure durations and radiation exposure data were compared between the two groups using Mann-Whitney U test. RESULTS: Using the DynaCT angiographic reconstruction technique, more target vessels were treated in a single BPA procedure (5.83 ± 2.33 vs 3.73 ± 1.10 vessels per BPA, p = 0.008) in a shorter operation time (3.58 ± 0.61 vs 4.49 ± 0.91 h, p = 0.002). Overall, the dose area product (DAP) was significantly higher for the 2D group than for the 3D group (13,901.82 ± 5549.69 vs 4682.82 ± 1950.64, p < 0.001). The use of the DynaCT angiographic reconstruction technique to guide BPA required a lower dose of contrast agent (225.22 ± 48.70 vs 292.73 ± 76.82 mL, p = 0.013) and less radiation exposure. CONCLUSIONS: The use of DynaCT angiographic reconstruction guidance in patients undergoing BPA is feasible and accurate. Images of DynaCT angiographic reconstruction may be beneficial for optimizing the operative process in BPA with reduced radiation exposure. KEY POINTS: • BPA guidance by DynaCT angiographic reconstruction is feasible and accurate. • DynaCT angiographic reconstruction may be beneficial for optimizing the operative process. • DynaCT angiographic reconstruction can reduce patient radiation dose due to multi-times of BPA sessions.

Antiviral Immunotoxin Against Bovine herpesvirus-1: Targeted Inhibition of Viral Replication and Apoptosis of Infected Cell.

Bovine herpesvirus 1 (BoHV-1) is a highly contagious viral pathogen which causes infectious bovine rhinotracheitis in cattle worldwide. Currently, there is no antiviral prophylactic treatment available capable of mitigating the disease impact and facilitating recovery from latent infection. In this study, we have engineered a novel recombinant anti-BoHV-1 immunotoxin construct termed "BoScFv-PE38" that consists of a single-chain monoclonal antibody fragment (scFv) fused with an active domain of Pseudomonas exotoxin A as a toxic effector (PE38). The recombinant BoScFv-PE38 immunotoxin expressed in a prokaryotic expression system has specific binding affinity for BoHV-1 glycoprotein D (gD) with a dissociation constant (Kd) of 12.81 nM and for BoHV-1 virus particles with a Kd value of 97.63 nM. We demonstrate that the recombinant BoScFv-PE38 is internalized into MDBK cell compartments that inhibit BoHV-1 replication with a half-maximal inhibitory concentration (IC50) of 4.95 ± 0.33 nM and a selective index (SI) of 456 ± 31. Furthermore, the BoScFv-PE38 exerted a cytotoxic effect through the induction of ATP and ammonia, leading to apoptosis of BoHV-1-infected cells and the inhibition of BoHV-1 replication in MDBK cells. Collectively, we show that BoScFv-PE38 can potentially be employed as a therapeutic agent for the treatment of BoHV-1 infection.

Bovine single chain Fv antibody inhibits bovine herpesvirus-1 infectivity by targeting viral glycoprotein D.

Glycoprotein D (gD) of bovine herpesvirus-1 (BoHV-1) is essential for attachment and penetration of cells during infection and is a major target for neutralizing antibodies during an adaptive immune response. Currently there are no recombinant antibodies capable of binding gD epitopes for use in treating BoHV-1 infection. In this study, a bovine scFv gene derived from a hybridoma secreting monoclonal antibodies (McAbs) against the amino acid motif MEESKGYEPP of gD was expressed in E. coli. Molecular modeling, western blot and ELISA analysis showed that this scFv had a high affinity for BoHV-1 gD, with a Kd of 161.2 ± 37.58 nM and for whole BoHV-1 virus, with a Kd of 67.44 ± 16.99 nM. In addition, this scFv displayed a high affinity for BoHV-1 antigen in an ELISA and competed with BoHV-1 anti-serum in a competitive ELISA. Immunofluorescence assay (IFA) and laser confocal microscopy showed that this scFv could efficiently bind to and be internalized by BoHV-1 infected Madin-Darby bovine kidney (MDBK) cells. Importantly, this scFv was shown to inhibit BoHV-1 infectivity and to reduce the number of viral plaques by blocking viral attachment to MDBK cells. Our study suggests that this bovine single-chain antibody could be developed for use as a diagnostic and therapeutic agent against BoHV-1 infection in cattle.

A DNA aptamer efficiently inhibits the infectivity of Bovine herpesvirus 1 by blocking viral entry.

Bovine herpesvirus 1 (BoHV-1) is an important pathogen of domestic and wild cattle responsible for major economic losses in dairy and beef industries throughout the world. Inhibition of viral entry plays a crucial role in the control of BoHV-1 infection and aptamers have been reported to inhibit viral replication. In this study, nine DNA aptamers that target BoHV-1 were generated using systemic evolution of ligands by exponential enrichment. Of the nine candidates, aptamer IBRV-A4 exhibited the highest affinity and specificity for BoHV-1, which bound to BoHV-1 with a Kd value of 3.519 nM and demonstrated the greatest virus binding as shown by fluorescence imaging. The neutralizing ability of aptamer IBRV-A4 was determined using neutralization assays and real time PCR in BoHV-1 infected Madin-darby bovine kidney cells. Virus titration, immunofluorescence and confocal laser scanning microscopy showed virus replication significantly decreased when aptamer IBRV-A4 was added to BoHV-1 infected MDBK cells at 0 and 0.5 hours post-infection, whereas no change was seen when IBRV-A4 was added 2 hours post-infection. This concludes that aptamer IBRV-A4 efficiently inhibits viral entry of BoHV-1 in MDBK cells and is therefore a novel tool for diagnosis and treatment of BoHV-1 infection in cattle.

Construction of Recombinant HVT Expressing PmpD, and Immunological Evaluation against Chlamydia psittaci and Marek's Disease Virus.

Chlamydia psittaci (C. psittaci) is an obligate intracellular zoonotic pathogen that can be transmitted to humans from birds. No efficacious commercial vaccine is available for clearing chlamydial infection due to lack of potential vaccine candidates and effective delivery vehicles. Herpesvirus of turkeys (HVT) is an efficacious commercially available vaccine against Marek's Disease virus (MDV). In this study, a recombinant HVT-delivered vaccine against C. psittaci and Marek's disease was developed and examined. The 5'-terminus of pmpD gene (pmpD-N) encoding the N-terminal fragment of polymorphic membrane protein D of C. psittaci was inserted into a nonessential region of HVT genome using reverse genetics based on an infectious bacterial artificial chromosome (BAC) clone of HVT. The recombinant virus (rHVT-pmpD-N) was recovered from primary chicken embryo fibroblast (CEF) cells by transfection of modified HVT BAC DNA containing the pmpD-N gene. The rHVT-pmpD-N construct was confirmed to express PmpD-N by immunoblot and immunofluorescence. The rHVT-pmpD-N was stable during 20 passages in vitro. The growth kinetics of rHVT-pmpD-N was comparable to that of parental HVT in vitro and in vivo. One-day-old SPF chickens inoculated subcutaneously with rHVT-pmpD-N displayed increased PmpD-specific antibody levels and a vigorous PmpD-specific lymphocyte proliferation response using HVT vector or CEF cells as control. Furthermore, the percentage of CD4+ cells was significantly elevated in rHVT-pmpD-N-immunized birds as compared to the parental HVT. All chickens vaccinated with rHVT-pmpD-N or parental HVT were protected completely against challenge with a very virulent strain of Marek's Disease virus (MDV) RB-1B. Post challenge with C. psittaci CB7 strain, a significant decrease in respiratory distress, lesions and Chlamydia load was found in the rHVT-pmpD-N-vaccinated group compared to the parental HVT. In conclusion, our study suggests that the rHVT-pmpD-N live vaccine may be viable as a candidate dual vaccine that provides protection against both very virulent MDV and C. psittaci.

Dynamics of intestinal flora after oral vaccination with inactivated whole-cell/recombinant B subunit O139 cholera vaccine.

OBJECTIVE: To investigate the change of intestinal flora in subjects receiving oral vaccination with inactivated whole-cell/recombinant B subunit (WC/rBS) O139 cholera vaccine made in China. METHODS: The fecal smears of 5 groups of subjects receiving the vaccine were collected before and 2 and 3 months after the vaccination to examine the distribution of the intestinal flora. RESULTS: In the 458 specimens examined, the total amount of bacteria and percentages of G+b, G+c and G-c were decreased whereas the amount of G-b significantly increased after vaccination. Compared with the placebo control group, the vaccinated groups exhibited significant changes in G+b and G-c, which also varied significantly between the group receiving 3 doses of WC/rBS vaccine and the other vaccinated groups. The vaccination produced distinct changes in the percentage of the intestinal flora at different time points, showing the most obvious effect on G-b. Oral vaccination was shown to affect the percentage of the intestinal flora very likely through its effect on the amount of G-b. The percentages of G+b, G-b and G-c varied significantly between male and female subjects after vaccination. CONCLUSION: Oral vaccination with WC/rBS affects the intestinal flora in human, and the mechanism as well as the implications needs to be further explored.