scholarly journals Fowl Adenovirus (FAdV) Recombination with Intertypic Crossovers in Genomes of FAdV-D and FAdV-E, Displaying Hybrid Serological Phenotypes

Viruses ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1094 ◽  
Author(s):  
Anna Schachner ◽  
Gabriel Gonzalez ◽  
Lukas Endler ◽  
Kimihito Ito ◽  
Michael Hess
Keyword(s):  
In Vivo Studies ◽  
Parental Origin ◽  
Fowl Adenovirus ◽  
Inclusion Body Hepatitis ◽  
New Type ◽  
Cross Neutralization ◽  
Species Specific ◽  
The Right ◽  
Important Disease

After analyzing 27 new genomes from fowl adenovirus (FAdV) field isolates and so-far unsequenced prototypes, we report the first evidence for recombination in FAdVs. Recombination was confined to species FAdV-D and FAdV-E, accommodating the largest number of, and the intraspecies-wise most differentiated, types. The majority of detected events occurred in FAdV-E, involving segments with parental origin of all constitutive types. Together with the diversity of breakpoints, this suggests widespread recombination in this species. With possible constraints through species-specific genes and diversification patterns, the recombinogenic potential of FAdVs attains particular interest for inclusion body hepatitis (IBH), an important disease in chickens, caused by types from the recombination-prone species. Autonomously evolving, recombinant segments were associated with major sites under positive selection, among them the capsid protein hexon and fiber genes, the right-terminal ORFs 19, 25, and the ORF20/20A family. The observed mosaicism in genes indicated as targets of adaptive pressures points toward an immune evasion strategy. Intertypic hexon/fiber-recombinants demonstrated hybrid neutralization profiles, retrospectively explaining reported controversies on reference strains B3-A, T8-A, and X11-A. Furthermore, cross-neutralization supported sequence-based evidence for interdomain recombination in fiber and contributed to a tentatively new type. Overall, our findings challenge the purported uniformity of types responsible for IBH, urging more complete identification strategies for FAdVs. Finally, important consequences arise for in vivo studies investigating cross-protection against IBH.

scholarly journals Pan-American Lancehead Pit-Vipers: Coagulotoxic Venom Effects and Antivenom Neutralisation of Bothrops asper and B. atrox Geographical Variants

Toxins ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 78
Author(s):  
Lachlan A. Bourke ◽  
Christina N. Zdenek ◽  
Edgar Neri-Castro ◽  
Melisa Bénard-Valle ◽  
Alejandro Alagón ◽  
...  
Keyword(s):  
Evolutionary Biology ◽  
Current Knowledge ◽  
Clinical Manifestations ◽  
In Vivo Studies ◽  
Factor X ◽  
Clotting Factors ◽  
Bothrops Asper ◽  
Species Specific

The toxin composition of snake venoms and, thus, their functional activity, can vary between and within species. Intraspecific venom variation across a species’ geographic range is a major concern for antivenom treatment of envenomations, particularly for countries like French Guiana that lack a locally produced antivenom. Bothrops asper and Bothrops atrox are the most medically significant species of snakes in Latin America, both producing a variety of clinical manifestations, including systemic bleeding. These pathophysiological actions are due to the activation by the venom of the blood clotting factors Factor X and prothrombin, thereby causing severe consumptive coagulopathy. Both species are extremely wide-ranging, and previous studies have shown their venoms to exhibit regional venom variation. In this study, we investigate the differential coagulotoxic effects on human plasma of six venoms (four B. asper and two B. atrox samples) from different geographic locations, spanning from Mexico to Peru. We assessed how the venom variation of these venom samples affects neutralisation by five regionally available antivenoms: Antivipmyn, Antivipmyn-Tri, PoliVal-ICP, Bothrofav, and Soro Antibotrópico (SAB). The results revealed both inter- and intraspecific variations in the clotting activity of the venoms. These variations in turn resulted in significant variation in antivenom efficacy against the coagulotoxic effects of these venoms. Due to variations in the venoms used in the antivenom production process, antivenoms differed in their species-specific or geographical neutralisation capacity. Some antivenoms (PoliVal-ICP, Bothrofav, and SAB) showed species-specific patterns of neutralisation, while another antivenom (Antivipmyn) showed geographic-specific patterns of neutralisation. This study adds to current knowledge of Bothrops venoms and also illustrates the importance of considering evolutionary biology when developing antivenoms. Therefore, these results have tangible, real-world implications by aiding evidence-based design of antivenoms for treatment of the envenomed patient. We stress that these in vitro studies must be backed by future in vivo studies and clinical trials before therapeutic guidelines are issued regarding specific antivenom use in a clinical setting.

scholarly journals SSB facilitates fork substrate discrimination by PriA

2020 ◽  
Author(s):  
Hui Yin Tan ◽  
Piero R. Bianco
Keyword(s):  
Catalytic Efficiency ◽  
Maximum Effect ◽  
Replication Forks ◽  
Replication Process ◽  
Replication Restart ◽  
Species Specific ◽  
The Right ◽  
Gene 32

AbstractPriA is a member of the SuperFamily 2 helicase family. Its role in vivo is to reload the primosome onto stalled replication forks resulting in the restart of the previously stalled DNA replication process. SSB is known to play key roles in mediating activities at replication forks and it is known to bind to PriA. To gain mechanistic insight into the PriA-SSB interaction, a coupled spectrophotometric assay was utilized to characterize the ATPase activity of PriA in vitro in the presence of fork substrates. The results demonstrate that SSB enhances the ability of PriA to discriminate between fork substrates 140-fold. This is due to a significant increase in the catalytic efficiency of the helicase induced by DNA-bound SSB. This interaction is species-specific as bacteriophage gene 32 protein cannot substitute for the E.coli protein. SSB, while enhancing the activity of PriA on its preferred fork, both decreases the affinity of the helicase for other forks and decreases catalytic efficiency. Central to the stimulation afforded by SSB is the unique ability of PriA to bind with high affinity to the 3’-OH placed at the end of the nascent leading strand at the fork. When both the 3’-OH and SSB are present, the maximum effect is observed. This ensures that PriA will only load onto the correct fork, in the right orientation, thereby ensuring that replication restart is directed to only the template lagging strand.

Development of a Full Flexion 3D Musculoskeletal Model of the Knee Considering Intersegmental Contact During High Knee Flexion Movements

2020 ◽  
Vol 36 (6) ◽  
pp. 444-456
Author(s):  
David C. Kingston ◽  
Stacey M. Acker
Keyword(s):  
Body Weight ◽  
Knee Flexion ◽  
Knee Extensor ◽  
Musculoskeletal Model ◽  
Contact Forces ◽  
Model Verification ◽  
In Vivo Studies ◽  
Muscle Groups ◽  
The Right

A musculoskeletal model of the right lower limb was developed to estimate 3D tibial contact forces in high knee flexion postures. This model determined the effect of intersegmental contact between thigh–calf and heel–gluteal structures on tibial contact forces. This model includes direct tracking and 3D orientation of intersegmental contact force, femoral translations from in vivo studies, wrapping of knee extensor musculature, and a novel optimization constraint for multielement muscle groups. Model verification consisted of calculating the error between estimated tibial compressive forces and direct measurements from the Grand Knee Challenge during movements to ∼120° of knee flexion as no high knee flexion data are available. Tibial compression estimates strongly fit implant data during walking (R2 = .83) and squatting (R2 = .93) with a root mean squared difference of .47 and .16 body weight, respectively. Incorporating intersegmental contact significantly reduced model estimates of peak tibial anterior–posterior shear and increased peak medial–lateral shear during the static phase of high knee flexion movements by an average of .33 and .07 body weight, respectively. This model supports prior work in that intersegmental contact is a critical parameter when estimating tibial contact forces in high knee flexion movements across a range of culturally and occupationally relevant postures.

scholarly journals User-Friendly Reverse Genetics System for Modification of the Right End of Fowl Adenovirus 4 Genome

Viruses ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 301
Author(s):  
Bingyu Yan ◽  
Xiaohui Zou ◽  
Xinglong Liu ◽  
Jiaming Zhao ◽  
Wenfeng Zhang ◽  
...  
Keyword(s):  
Reverse Genetics ◽  
Economic Losses ◽  
Virus Growth ◽  
Recombinant Viruses ◽  
Fowl Adenovirus ◽  
Viral Genes ◽  
Lmh Cells ◽  
Species Specific ◽  
The Right ◽  
User Friendly

A novel fowl adenovirus 4 (FAdV-4) has caused significant economic losses to the poultry industry in China since 2015. We established an easy-to-use reverse genetics system for modification of the whole right and partial left ends of the novel FAdV-4 genome, which worked through cell-free reactions of restriction digestion and Gibson assembly. Three recombinant viruses were constructed to test the assumption that species-specific viral genes of ORF4 and ORF19A might be responsible for the enhanced virulence: viral genes of ORF1, ORF1b and ORF2 were replaced with GFP to generate FAdV4-GFP, ORF4 was replaced with mCherry in FAdV4-GFP to generate FAdV4-GX4C, and ORF19A was deleted in FAdV4-GFP to generate FAdV4-CX19A. Deletion of ORF4 made FAdV4-GX4C form smaller plaques while ORF19A deletion made FAdV4-CX19A form larger ones on chicken LMH cells. Coding sequence (CDS) replacement with reporter mCherry demonstrated that ORF4 had a weak promoter. Survival analysis showed that FAdV4-CX19A-infected chicken embryos survived one more day than FAdV4-GFP- or FAdV4-GX4C-infected ones. The results illustrated that ORF4 and ORF19A were non-essential genes for FAdV-4 replication although deletion of either gene influenced virus growth. This work would help function study of genes on the right end of FAdV-4 genome and facilitate development of attenuated vaccines.

Pituitary gland: one site of ultrashort-feedback regulation for control of thyrotropin

1986 ◽  
Vol 250 (2) ◽  
pp. E121-E124
Author(s):  
T. Kakita ◽  
W. D. Odell
Keyword(s):  
Feedback Regulation ◽  
In Vivo Studies ◽  
Pituitary Cells ◽  
Site Of Action ◽  
Loop Feedback ◽  
Species Specific ◽  
A Site ◽  
Hypothalamic Level

Studies from our laboratory have previously demonstrated sensitive and specific autoregulatory control systems for thyrotropin (TSH), luteinizing hormone (LH), and follicle-stimulating hormone (FSH) in the rabbit. Because our studies of LH autoregulation showed the feedback regulation acted directly at a pituitary level, the current studies were designed to investigate whether the TSH control system also acted at the pituitary level. Two species-specific TSH assays were employed; a rabbit TSH radioimmunoassay which showed little or no reaction to human TSH, and a human TSH radioimmunoassay which showed little or no reaction to rabbit TSH. Both in vivo and in vitro studies were performed. TRH (thyrotropin-releasing hormone) in doses of 2, 10, and 50 micrograms was injected as an intravenous bolus into thyroidectomized hypothyroid rabbits during continuous perfusion with highly purified human TSH (hTSH) or with saline. In these in vivo studies, TRH-stimulated rabbit TSH (rTSH) secretion was suppressed by hTSH perfusion compared with control saline perfusion. The effect of hTSH was studied in vitro by employing short-term cultured rabbit pituitary cells. When hTSH was added to the incubation medium, TRH-stimulated rTSH secretion was inhibited. From these studies, we conclude that one site of the autoregulatory control for TSH in the rabbit is at the pituitary level. These studies do not exclude a possible additional short-loop feedback control at an hypothalamic level, but such a site of action is not required to explain the autoregulatory phenomenon.

scholarly journals Exfoliative toxin E, a new Staphylococcus aureus virulence factor with host-specific activity

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Ichiro Imanishi ◽  
Aurélie Nicolas ◽  
Ana-Carolina Barbosa Caetano ◽  
Thiago Luiz de Paula Castro ◽  
Natayme Rocha Tartaglia ◽  
...  
Keyword(s):  
Virulence Factor ◽  
Serine Proteases ◽  
Specific Activity ◽  
Bacterial Colonization ◽  
Exfoliative Toxin ◽  
New Type ◽  
Genetic Level ◽  
Staphylococcal Skin Infections ◽  
Species Specific

Abstract Exfoliative toxins (ETs) are secreted virulence factors produced by staphylococci. These serine proteases specifically cleave desmoglein 1 (Dsg1) in mammals and are key elements in staphylococcal skin infections. We recently identified a new et gene in S. aureus O46, a strain isolated from ovine mastitis. In the present study, we characterized the new et gene at a genetic level and the enzymatic activity of the deduced protein. The S. aureus O46 genome was re-assembled, annotated and compared with other publicly available S. aureus genomes. The deduced amino acid sequence of the new et gene shared 40%, 53% and 59% sequence identity to those of ETA, ETB and ETD, respectively. The new et gene shared the same genetic vicinity and was similar in other S. aureus strains bearing this gene. The recombinant enzyme of the new et gene caused skin exfoliation in vivo in neonatal mice. The new et-gene was thus named ete, encoding a new type (type E) of exfoliative toxin. We showed that ETE degraded the extracellular segments of Dsg1 in murine, ovine and caprine epidermis, as well as in ovine teat canal epithelia, but not that in bovine epidermis. We further showed that it directly hydrolyzed human and swine Dsg1 as well as murine Dsg1α and Dsg1β, but not canine Dsg1 or murine Dsg1γ. Molecular modeling revealed a correlation between the preferred orientation of ETE docking on its Dsg1 cleavage site and species-specific cleavage activity, suggesting that the docking step preceding cleavage accounts for the ETE species-specificity. This new virulence factor may contribute to the bacterial colonization on the stratified epithelia in certain ruminants with mastitis.

Off-Pump Tricuspid Annuloplasty through a Direct Transatrial Approach: Early Results

2019 ◽  
Vol 68 (06) ◽  
pp. 503-506
Author(s):  
Martin Andreas ◽  
Paul Werner ◽  
Guenther Laufer ◽  
Jude Sauer
Keyword(s):  
Clinical Investigation ◽  
In Vivo Studies ◽  
Severe Tricuspid Regurgitation ◽  
Off Pump ◽  
Tricuspid Annuloplasty ◽  
Early Results ◽  
Increased Risk ◽  
The Right ◽  
Further Development

AbstractSevere tricuspid regurgitation constitutes a growing disease burden. Conventional surgery for tricuspid valve disease has an increased risk while several interventional procedures are currently under clinical investigation, yet do not offer comprehensive solutions. We investigated a novel surgical approach for off-pump beating-heart tricuspid annuloplasty in circulating blood through a single port in the right atrium. Early feasibility results in preclinical porcine in vivo studies encourage further development of this approach, combining the proven concept of surgical annuloplasty with the benefits of minimally invasive off-pump procedures in a hybrid setting.

Chronotropic actions of bPTH-(1–34) in the right atrium of the rat

1983 ◽  
Vol 61 (10) ◽  
pp. 1162-1167 ◽  
Author(s):  
Thomas E. Tenner Jr. ◽  
Sasanka Ramanadham ◽  
May C. M. Yang ◽  
Peter K. T. Pang
Keyword(s):  
In Vivo Studies ◽  
Hypotensive Activity ◽  
Reflex Tachycardia ◽  
Chronotropic Action ◽  
Chronotropic Effects ◽  
The Right ◽  
Dose Dependent ◽  
Right Atria

Bovine parathyroid hormone and its N-terminal (1–34) peptide fragment (bPTH-(1–34)) are known to possess direct hypotensive activity in the rat. The purpose of the present study was to determine if bPTH-(1–34) possessed a direct chronotropic action as well. In vivo studies revealed that bPTH-(1–34) did produce a chronotropic effect in the rat comprising both a direct component as well as a reflex tachycardia related to its hypotensive actions. In vitro studies of isolated right atria indicated that while bPTH-(1–34) had no positive inotropic effect, it did produce significant chronotropic effects which were direct and dose-dependent. The potency of bPTH-(1–34) was found to be similar to that of isoproterenol, however, it was only one-third as effective as isoproterenol in maximally increasing atrial rate. A slight but significant increase in atrial cyclic AMP was generated prior to the chronotropic actions of bPTH-(1–34).

scholarly journals Heterozygous Disruption of the TATA-Binding Protein Gene in DT40 Cells Causes Reduced cdc25B Phosphatase Expression and Delayed Mitosis

2001 ◽  
Vol 21 (7) ◽  
pp. 2435-2448 ◽  
Author(s):  
Moonkyoung Um ◽  
Jun Yamauchi ◽  
Shigeaki Kato ◽  
James L. Manley
Keyword(s):  
Binding Protein ◽  
Tata Binding Protein ◽  
In Vivo Studies ◽  
Mutant Form ◽  
Lower Growth ◽  
Protein Levels ◽  
Species Specific ◽  
Dt40 Cells

ABSTRACT TATA-binding protein (TBP) is a key general transcription factor required for transcription by all three nuclear RNA polymerases. Although it has been intensively analyzed in vitro and inSaccharomyces cerevisiae, in vivo studies of vertebrate TBP have been limited. We applied gene-targeting techniques using chicken DT40 cells to generate heterozygous cells with one copy of theTBP gene disrupted. Such TBP-heterozygous (TBP-Het) cells showed unexpected phenotypic abnormalities, resembling those of cells with delayed mitosis: a significantly lower growth rate, larger size, more G2/-M- than G1-phase cells, and a high proportion of sub-G1, presumably apoptotic, cells. Further evidence for delayed mitosis in TBP-Het cells was provided by the differential effects of several cell cycle-arresting drugs. To determine the cause of these defects, we first examined the status of cdc2 kinase, which regulates the G2/M transition, and unexpectedly observed more hyperphosphorylated, inactive cdc2 in TBP-Het cells. Providing an explanation for this, mRNA and protein levels of cdc25B, the trigger cdc2 phosphatase, were significantly and specifically reduced. These properties were all due to decreased TBP levels, as they could be rescued by expression of exogeneous TBP, including, in most but not all cases, a mutant form lacking the species-specific N-terminal domain. Our results indicate that small changes in TBP concentration can have profound effects on cell growth in vertebrate cells.

scholarly journals A Robust Bioassay of the Human Bradykinin B2 Receptor that Extends Molecular and Cellular Studies: The Isolated Umbilical Vein

2021 ◽  
Vol 14 (3) ◽  
pp. 177
Author(s):  
François Marceau ◽  
Hélène Bachelard
Keyword(s):  
Partial Agonist ◽  
Umbilical Vein ◽  
In Vivo Studies ◽  
Molecular Pharmacology ◽  
Smooth Muscle Contractility ◽  
Competitive Antagonist ◽  
Pharmacological Agents ◽  
Species Specific ◽  
G Protein Coupled

Bradykinin (BK) has various physiological and pathological roles. Medicinal chemistry efforts targeted toward the widely expressed BK B2 receptor (B2R), a G-protein-coupled receptor, were primarily aimed at developing antagonists. The only B2R antagonist in clinical use is the peptide icatibant, approved to abort attacks of hereditary angioedema. However, the anti-inflammatory applications of B2R antagonists are potentially wider. Furthermore, the B2R antagonists notoriously exhibit species-specific pharmacological profiles. Classical smooth muscle contractility assays are exploited over a time scale of several hours and support determining potency, competitiveness, residual agonist activity, specificity, and reversibility of pharmacological agents. The contractility assay based on the isolated human umbilical vein, expressing B2R at physiological density, was introduced when investigating the first non-peptide B2R antagonist (WIN 64338). Small ligand molecules characterized using the assay include the exquisitely potent competitive antagonist, Pharvaris Compound 3 or the partial agonist Fujisawa Compound 47a. The umbilical vein assay is also useful to verify pharmacologic properties of special peptide B2R ligands, such as the carboxypeptidase-activated latent agonists and fluorescent probes. Furthermore, the proposed agonist effect of tissue kallikrein on the B2R has been disproved using the vein. This assay stands in between cellular and molecular pharmacology and in vivo studies.

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