Laparoscopic cholecystectomy using the subserosal layer dissection technique in dogs: 34 cases (2015‐2021)

OBJECTIVES

To describe a standardised subserosal layer dissection technique and evaluate its outcomes in canine laparoscopic cholecystectomy.

MATERIALS AND METHODS

Medical records of dogs undergoing laparoscopic cholecystectomy using the standardised subserosal layer dissection technique for the treatment of cholecystolithiasis, cholecystitis, and gall bladder mucocele at a single veterinary hospital from January 2015 to September 2021 were extracted. Operative time, subserosal layer dissection achievement rate, open conversion rate, and complication rate were evaluated.

RESULTS

Thirty-four dogs were included. The most common preoperative diagnosis was cholecystolithiasis (n=29). Operative time was 190 minutes (range: 110 to 330 minutes). Subserosal layer dissection of more than 90% of the gall bladder bed was achieved in 27 (79%) dogs. Conversion to open surgery was required in three (8.8%) dogs. There were no cases of intraoperative bleeding, bile duct injury, or reoperation.

CLINICAL SIGNIFICANCE

This study showed that laparoscopic cholecystectomy using the standardised subserosal layer dissection technique could be performed successfully in dogs. Future prospective clinical studies are needed to determine safety and effectiveness of this technique compared to standard techniques.

WO3 Photocatalyst Containing Copper Inactivates SARS-CoV-2 Pango Lineage A and Omicron BA.2 Variant in Visible Light and in Darkness

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of coronavirus disease 2019, which has been a global pandemic. Since SARS-CoV-2 is transmitted through contaminated surfaces and aerosols, environmental disinfection is important to block the spread of the virus. Photocatalysts are attractive tools for virus inactivation and are widely used as air purifiers and coating materials. However, photocatalysts are inactive in the dark, and some of them need to be excited with light of a specific wavelength. Therefore, photocatalysts that can effectively inactivate SARS-CoV-2 in indoor environments are needed. Here, we show that a WO3 photocatalyst containing copper inactivated the SARS-CoV-2 WK-521 strain (Pango lineage A) upon irradiation with white light in a time- and concentration-dependent manner. Additionally, this photocatalyst also inactivated SARS-CoV-2 in dark conditions due to the antiviral effect of copper. Furthermore, this photocatalyst inactivated not only the WK-521 strain but also the Omicron variant BA.2. These results indicate that the WO3 photocatalyst containing copper can inactivate indoor SARS-CoV-2 regardless of the variant, in visible light or darkness, making it an effective tool for controlling the spread of SARS-CoV-2.

The uncoating of EV71 in mature late endosomes requires CD-M6PR

Enterovirus 71 (EV71) is one of the causative agents of hand-foot-and-mouth disease, which in some circumstances could lead to severe neurological diseases. Despite of its importance for human health, little is known about the early stages of EV71 infection. EV71 starts uncoating with its receptor, human scavenger receptor B2 (hSCARB2), at low pH. We show that EV71 was not targeted to lysosomes in human rhabdomyosarcoma cells overexpressing hSCARB2 and that the autophagic pathway is not essential for EV71 productive uncoating. Instead, EV71 was efficiently uncoated 30 minutes after infection in late endosomes (LEs) containing hSCARB2, mannose-6-phosphate receptor (M6PR), RAB9, bis(monoacylglycero)phosphate and lysosomal associated membrane protein 2 (LAMP2). Furthering the notion that mature LEs are crucial for EV71 uncoating, cation-dependent (CD)-M6PR knockdown impairs EV71 infection. Since hSCARB2 interacts with cation-independent (CI)-M6PR through M6P-binding sites and CD-M6PR also harbor a M6P-binding site, CD-M6PR is likely to play important roles in EV71 uncoating in LEs.

Changes in immune system and intestinal bacteria of cows during the transition period

•

Transitional high-energy diets reduce peripheral blood lymphocytes in dairy cows.

•

High-energy diets upregulate IL-1β and IL-2 and downregulate IL-10 expression.

•

Functional lactobacillus plantarum LP1 restores normal levels of lymphocytes subset.

•

Lactobacillus plantarum LP1-added diets reduce inflammatory cytokine expression.

•

LP1 mitigates immune response imbalances caused by transitional high energy diets.

High-yield dairy cows need high energy feed during periods of increased milk production. The transitional feeding to high energy feed increases the risk of developing a variety of metabolic disorders. Here, five Holstein cows were fed a four-stage feeding protocol (3 weeks for each stage) ranging from 54.9 to 73.7% total digestive nutrients (TDN). The purpose of the study was to investigate the effect of lactic acid bacteria on high-energy-fed cows associated with transitional feeding, and to evaluate the effects of probiotics on intestinal bacterial changes and inflammatory responses. Three feed transition periods were established for five cows, and Lactobacillus plantarum RGU-LP1 (LP1) was fed as a probiotic during the high-energy feeding period. The number of lymphocyte subsets such as CD3-, CD4-, and CD8 positive cells decreased in response to the high energy feed. Lipopolysaccharide (LPS)-induced cytokine (IL-1β and IL-2) gene expression in peripheral blood mononuclear cells (PBMCs) was shown to increase in those animals receiving the high energy feed. However, supplementation with LP1 resulted in an increase in the number of lymphocyte subsets and the expression of IL-1β and IL-2 were returned to the level at low energy diet. These results suggest that high energy diets induce inflammatory cytokine responses following LPS stimulation, and that the addition of LP1 mitigates these results by regulating the LPS-induced inflammatory reaction. Therefore, the functional lactic acid bacteria LP1 is expected to regulate inflammation resulting from high energy feeding, and this probiotic could be applied to support inflammatory regulation in high-yield dairy cows.

Development of a Non-IgG PD-1/PD-L1 Inhibitor by in Silico Mutagenesis and an In-Cell Protein-Protein Interaction Assay

Inhibiting the programmed death-1 (PD-1)/programmed death ligand 1 (PD-L1) axis by monoclonal antibodies (mAbs) is a successful cancer immunotherapy. However, mAb-based drugs have various disadvantages including high production costs and large molecular sizes, which motivated us to develop a smaller alternative drug. Since PD-L1 binds PD-1 with moderate affinity, a higher affinity PD-1 variant should serve as a competitive inhibitor of the wild-type PD-1/PD-L1 interaction. In this report, we conducted in silico point mutagenesis of PD-1 to identify potent PD-1 variants with a higher affinity toward PD-L1 and refined the in silico results using a luciferase-based in-cell protein-protein interaction (PPI) assay. As a result, a PD-1 variant was developed that had two mutated amino acids (T76Y, A132V), termed 2-PD-1. 2-PD-1 could bind with PD-L1 at a dissociation constant of 12.74 nM. Moreover, 2-PD-1 successfully inhibited the PD-1/PD-L1 interaction with a half maximal inhibitory concentration of 19.15 nM and reactivated the T cell with a half maximal effective concentration of 136.1 nM. These results show that in silico mutagenesis combined with an in-cell PPI assay verification strategy successfully prepared a non-IgG inhibitor of the PD-1/PD-L1 interaction.

Cepharanthine induces the proliferation of human dermal papilla cells and stimulates vascular endothelial growth factor expression through increased intracellular calcium mobilization and hypoxia-inducible factor activation

BACKGROUND

Cepharanthine (CEP), a compound extracted from the vine Stephania cephalantha, is commonly prescribed to treat alopecia areata; however, the scientific evidence for its efficacy is limited.

AIM

To investigate the effect of CEP and its structural analogues on human hair growth in vitro.

METHODS

The effects of CEP and three of its structural analogues on the proliferation of human dermal papilla cells (hDPCs) and human outer root sheath cells (hORSCs) were investigated. Their effects on vascular endothelial growth factor (VEGF) expression were also assessed by real-time PCR. Activation of pathways leading to VEGF expression, such as intracellular Ca²⁺ mobilization and hypoxia-inducible factor (HIF) expression, was also characterized.

RESULTS

CEP and two of its structural analogues significantly stimulated the growth of hDPCs but not hORSCs. Moreover, CEP and all three structural analogues significantly induced the expression of VEGF in hDPCs. CEP increased the intracellular Ca²⁺ concentration in hDPCs. CEP also increased the expression of HIF-1α and HIF-2α and induced the expression of HIF-responsive genes in hDPCs, even under normoxia.

CONCLUSIONS

These results suggest that CEP and its structural analogues have the potential to restore hair growth by promoting the proliferation of hDPCs and increasing their expression of VEGF.

P1032Efficacy and safety of radiofrequency catheter ablation for atrial fibrillation in patients undergoing hemodaialysis

Introduction

Although radiofrequency catheter ablation (RFCA) for atrial fibrillation (AF) has become a standard therapy, the ablation outcomes in patients undergoing hemodialysis (HD) has not been fully elucidated. The present study aimed to evaluate the clinical outcomes of RFCA for AF in patients undergoing HD.

Methods

Twenty-three patients undergoing HD (17 men, age 65±8 years, 19 paroxysmal AF) who underwent RFCA for drug-refractory AF in two institutes were enrolled in the study and defined as HD group. The clinical parameters, recurrence free rate and frequency of periprocedural complications were compared to 46 randomly selected age, gender and left atrial diameter matched controls not requiring HD defined as non-HD group (34men, age 67±7 years, 38 paroxysmal AF).

Results

The patients in HD group had a significantly lower body mass index (21±3 vs. 25±3 P<0.01), higher prevalence of coronary artery disease (30% vs. 10% P=0.04), and higher prevalence of congestive heart failure (52% vs. 10% P<0.01) compared to patients in non-HD group. Echocardiography indicated lower left ventricular ejection fraction (57±17% vs. 65±9% P=0.02), higher E/e' (20±8 vs. 12±4 P<0.01), higher tricuspid regurgitation pressure gradient (30mmHg vs. 24mmHg P<0.01) and more impaired left ventricular diastolic function in HD group. All the subjects underwent bilateral pulmonary vein isolation plus additional linear lesion. The number of ablation procedure was similar between the two groups (1.43±0.5 vs. 1.46±0.6 P=0.88). During the follow-up period of 37±25 months after the last procedure, the arrhythmia free rate was similar between the two groups (86% vs. 84% log-rank P=0.82). Vascular access complication occurred in two patients in HD group, and pericardial effusion occurred in one patient in non-HD group, while no life-threatening complications were observed in either group. Cardiogenic cerebral infarction occurred in one patient in non-HD group. Discontinuation of oral anticoagulation after the ablation was more often seen in the HD group compared to non-HD group (91% vs. 60% P<0.01).

Conclusions

Although patients undergoing HD had more impaired left ventricular systolic and diastolic function, RFCA for AF in patients with HD was shown to be as effective and safe as in non-HD patients. RFCA may be an efficient approach to manage AF in patients undergoing HD.

Enhancement of synergistic gene silencing by RNA interference using branched “3-in-1” trimer siRNA

Nanostructured RNA carrying three different siRNAs was assembled to silence three target genes (Axin, APC, and GSK-3β) in the Wnt/β-catenin signaling pathway. This nanostructured ‘3-in-1’ siRNA showed high activity at a low concentration due to the long-term resistance, and enhancing the effect of RNA interference.

A novel sphingomyelin/cholesterol domain-specific probe reveals the dynamics of the membrane domains during virus release and in Niemann-Pick type C

We identified a novel, nontoxic mushroom protein that specifically binds to a complex of sphingomyelin (SM), a major sphingolipid in mammalian cells, and cholesterol (Chol). The purified protein, termed nakanori, labeled cell surface domains in an SM- and Chol-dependent manner and decorated specific lipid domains that colocalized with inner leaflet small GTPase H-Ras, but not K-Ras. The use of nakanori as a lipid-domain-specific probe revealed altered distribution and dynamics of SM/Chol on the cell surface of Niemann-Pick type C fibroblasts, possibly explaining some of the disease phenotype. In addition, that nakanori treatment of epithelial cells after influenza virus infection potently inhibited virus release demonstrates the therapeutic value of targeting specific lipid domains for anti-viral treatment.-Makino, A., Abe, M., Ishitsuka, R., Murate, M., Kishimoto, T., Sakai, S., Hullin-Matsuda, F., Shimada, Y., Inaba, T., Miyatake, H., Tanaka, H., Kurahashi, A., Pack, C.-G., Kasai, R. S., Kubo, S., Schieber, N. L., Dohmae, N., Tochio, N., Hagiwara, K., Sasaki, Y., Aida, Y., Fujimori, F., Kigawa, T., Nishibori, K., Parton, R. G., Kusumi, A., Sako, Y., Anderluh, G., Yamashita, M., Kobayashi, T., Greimel, P., Kobayashi, T. A novel sphingomyelin/cholesterol domain-specific probe reveals the dynamics of the membrane domains during virus release and in Niemann-Pick type C.

High Density of Aligned Nanowire Treated with Polydopamine for Efficient Gene Silencing by siRNA According to Cell Membrane Perturbation

High aspect ratio nanomaterials, such as vertically aligned silicon nanowire (SiNW) substrates, are three-dimensional topological features for cell manipulations. A high density of SiNWs significantly affects not only cell adhesion and proliferation but also the delivery of biomolecules to cells. Here, we used polydopamine (PD) that simply formed a thin coating on various material surfaces by the action of dopamine as a bioinspired approach. The PD coating not only enhanced cell adhesion, spreading, and growth but also anchored more siRNA by adsorption and provided more surface concentration for substrate-mediated delivery. By comparing plain and SiNW surfaces with the same amount of loaded siRNA, we quantitatively found that PD coating efficiently anchored siRNA on the surface, which knocked down the expression of a specific gene by RNA interference. It was also found that the interaction of SiNWs with the cell membrane perturbed the lateral diffusion of lipids in the membrane by fluorescence recovery after photobleaching. The perturbation was considered to induce the effective delivery of siRNA into cells and allow the cells to carry out their biological functions. These results suggest promising applications of PD-coated, high-density SiNWs as simple, fast, and versatile platforms for transmembrane delivery of biomolecules.

Molecular Mechanism of HIV-1 Vpr for Binding to Importin-α

Viral protein R (Vpr) is an accessory gene product of human immunodeficiency virus type 1 (HIV-1) that plays multiple important roles associated with viral replication. Structural studies using NMR have revealed that Vpr consists of three α-helices and contains flexible N- and C-termini. However, the molecular mechanisms associated with Vpr function have not been elucidated. To investigate Vpr multifunctionality, we performed an X-ray crystallographic study of Vpr complexes containing importin-α, a known Vpr binding partner present in host cells. Elucidation of the crystal structure revealed that the flexible C-terminus changes its conformation to a twisted β-turn via an induced-fit mechanism, enabling binding to a minor nuclear localization signal (NLS) site of importin-α. The Vpr C-terminus can also bind with major NLS sites of importin-α in an extended conformation in different ways. These results, which represent the first reported crystallographic analysis of Vpr, demonstrate the multifunctional aspects that enable Vpr interaction with a variety of cellular proteins.

Synthesis of a Vpr-Binding Derivative for Use as a Novel HIV-1 Inhibitor

The emergence of multidrug-resistant viruses compromises the efficacy of anti-human immunodeficiency virus type 1 (HIV-1) therapy and limits treatment options. Therefore, new targets that can be used to develop novel antiviral agents need to be identified. We previously identified a potential parent compound, hematoxylin, which suppresses the nuclear import of HIV-1 via the Vpr-importin α interaction and inhibits HIV-1 replication in a Vpr-dependent manner by blocking nuclear import of the pre-integration complex. However, it was unstable. Here, we synthesized a stable derivative of hematoxylin that bound specifically and stably to Vpr and inhibited HIV-1 replication in macrophages. Furthermore, like hematoxylin, the derivative inhibited nuclear import of Vpr in an in vitro nuclear import assay, but had no effect on Vpr-induced G2/M phase cell cycle arrest or caspase activity. Interestingly, this derivative bound strongly to amino acid residues 54–74 within the C-terminal α-helical domain (αH3) of Vpr. These residues are highly conserved among different HIV strains, indicating that this region is a potential target for drug-resistant HIV-1 infection. Thus, we succeeded in developing a stable hematoxylin derivative that bound directly to Vpr, suggesting that specific inhibitors of the interaction between cells and viral accessory proteins may provide a new strategy for the treatment of HIV-1 infection.

Low-Molecular-Weight Polyethyleneimine Grafted Polythiophene for Efficient siRNA Delivery

Owing to its hydrophilicity, negative charge, small size, and labile degradation by endogenous nucleases, small interfering RNA (siRNA) delivery must be achieved by a carrier system. In this study, cationic copolymers composed of low-molecular-weight polyethylenimine and polythiophenes were synthesized and evaluated as novel self-tracking siRNA delivery vectors. The concept underlying the design of these copolymers is that hydrophobicity and rigidity of polythiophenes should enhance the transport of siRNA across the cell membrane and endosomal membrane. A gel retardation assay showed that the nanosized complexes formed between the copolymers and siRNA were stable even at a molar ratio of 1 : 2. The high cellular uptake (>80%) and localization of the copolymer vectors inside the cells were easily analyzed by tracking the fluorescence of polythiophene using fluorescent microscopy and cytometry. An in vitro luciferase knockdown (KD) assay in A549-luc cells demonstrated that the siRNA complexes with more hydrophobic copolymers achieved a higher KD efficiency of 52.8% without notable cytotoxicity, indicating protein-specific KD activity rather than solely the cytotoxicity of the materials. Our polythiophene copolymers should serve as novel, efficient, low cell toxicity, and label-free siRNA delivery systems.

Superior cell penetration by a rigid and anisotropic synthetic protein

Molecules with structural anisotropy and rigidity, such as asbestos, demonstrate high cell-penetrating activity but also high toxicity. Here we synthesize a biodegradable, rigid, and fibrous artificial protein, CCPC 140, as a potential vehicle for cellular delivery. CCPC 140 penetrated 100% of cells tested in vitro, even at a concentration of 3.1 nM-superior to previously reported cell-penetrating peptides. The effects of cell-strain-dependency and aspect ratio on the cell-penetrating activity of CCPC 140 were also investigated.

Amphiphilic gold nanoparticles displaying flexible bifurcated ligands as a carrier for siRNA delivery into the cell cytosol

The nanoparticle-based delivery of siRNA with a noncationic outermost surface at a low particle concentration is greatly desired. We newly synthesized a bifurcated ligand (BL) possessing hydrophobic and hydrophilic arms as a surface ligand for gold nanoparticles (AuNPs) to allow siRNA delivery. The concept underlying the design of this ligand is that amphiphilic property should allow AuNPs to permeate the cell cytosol thorough the endosomal membrane. BLs and quaternary cationic ligands were codisplayed on 40 nm AuNPs, which were subsequently coated with siRNA via electrostatic interaction. The number of siRNAs immobilized on a single nanoparticle was 26, and the conjugate showed a negative zeta potential due to siRNAs on the outermost surface of the AuNPs. Apparent gene silencing of luciferase expression in HeLa cells was achieved at an AuNP concentration as low as 60 pM. Almost no gene silencing was observed for AuNPs not displaying BLs. To reveal the effect of the BL, we compared the number of AuNPs internalized into HeLa cells and the localization in the cytosol between AuNPs displaying and those not displaying BLs. These analyses indicated that the role of BLs is not only the simple promotion of cellular uptake but also involves the enhancement of AuNPs permeation into the cytosol from the endosomes, leading to effective gene silencing.

Enhanced cellular uptake of amphiphilic gold nanoparticles with ester functionality

Gold nanoparticles (AuNPs) coated with ester-headed or ether-headed PEG ligands were synthesized.

Importin α3/Qip1 is involved in multiplication of mutant influenza virus with alanine mutation at amino acid 9 independently of nuclear transport function

The nucleoprotein (NP) of influenza A virus is transported into the nucleus via the classical importin α/β pathway, and proceeds via nuclear localization signals (NLSs) recognized by importin α molecules. Although NP binds to importin α isoforms Rch1, Qip1 and NPI-1, the role of each individual isoform during the nuclear transport of NP and replication of the influenza virus remains unknown. In this study, we examined the contribution of importin α isoforms for nuclear localization of NP and viral growth using a panel of NP mutants containing serial alanine replacements within an unconventional NLS of NP. Alanine mutation at amino acid 8 (R8A) caused a significant reduction in the nuclear localization and binding to the three importin isoforms. The R8A NP mutant virus did not generate by reverse-genetics approach. This indicates that position 8 is the main site that mediates nuclear localization via interactions with Rch1, Qip1 and NPI-1, and subsequent viral production. This was confirmed by the finding that the conservation of amino acid 8 in human- and avian-origin influenza virus NP was necessary for virus propagation. By contrast, another mutant, S9A NP, which localized in the nucleus, caused a reduction in viral growth and vRNA transcription, suggesting that the unconventional NLS within NP may be associated with nuclear transport, vRNA transcription and viral replication through independent pathways. Interestingly, the N-terminal 110-amino acid region, which contained the unconventional NLS with S9A mutation, mainly bound to Qip1. Furthermore, activities of vRNA transcription and replication of S9A NP mutants were decreased by silencing Qip1 in without changing nuclear localization, indicating that Qip1 involves in multiplication of S9A mutant virus independently of nuclear transport function. Collectively, our results demonstrate the unconventional NLS within NP might have the additional ability to regulate the viral replication that is independent of nuclear localization activity via interactions with Qip1.

An evaluation study of EGFR mutation tests utilized for non-small-cell lung cancer in the diagnostic setting

BACKGROUND

Epidermal growth factor receptor (EGFR) mutation is predictive for the efficacy of EGFR tyrosine kinase inhibitors in advanced non-small-cell lung cancer (NSCLC) treatment. We evaluated the performance, sensitivity, and concordance between five EGFR tests.

MATERIALS AND METHODS

DNA admixtures (n = 34; 1%-50% mutant plasmid DNA) and samples from NSCLC patients [116 formalin-fixed paraffin-embedded (FFPE) tissue, 29 matched bronchofiberscopic brushing (BB) cytology, and 20 additional pleural effusion (PE) cytology samples] were analyzed. EGFR mutation tests were PCR-Invader, peptide nucleic acid-locked nucleic acid PCR clamp, direct sequencing, Cycleave, and Scorpion Amplification Refractory Mutation System (ARMS). Analysis success, mutation status, and concordance rates were assessed.

RESULTS

All tests except direct sequencing detected four mutation types at ≥1% mutant DNA. Analysis success rates were 91.4%-100% (FFPE) and 100% (BB and PE cytology), respectively. Inter-assay concordance rates of successfully analyzed samples were 94.3%-100% (FFPE; kappa coefficients: 0.88-1.00), 93.1%-100% (BB cytology; 0.86-1.00), and 85.0%-100% (PE cytology; 0.70-1.00), and 93.1%-96.6% (0.86-0.93) between BB cytology and matched FFPE.

CONCLUSIONS

All EGFR assays carried out comparably in the analysis of FFPE and cytology samples. Cytology-derived DNA is a viable alternative to FFPE samples for analyzing EGFR mutations.