scholarly journals Masticatory system integration in a commensal canid: interrelationships between bones, muscles and bite force in the red fox

2021 ◽  
Vol 224 (5) ◽  
Author(s):  
Colline Brassard ◽  
Marilaine Merlin ◽  
Elodie Monchâtre-Leroy ◽  
Claude Guintard ◽  
Jacques Barrat ◽  
...  
Keyword(s):  
Red Fox ◽  
Bite Force ◽  
Similar Amount ◽  
Canis Lupus Familiaris ◽  
Cross Sectional ◽  
Domestic Species ◽  
Mandible Shape ◽  
The Impact ◽  
Strong Relationships

ABSTRACT The jaw system in canids is essential for defence and prey acquisition. However, how it varies in wild species in comparison with domestic species remains poorly understood, yet is of interest in terms of understanding the impact of artificial selection. Here, we explored the variability and interrelationships between the upper and lower jaws, muscle architecture and bite force in the red fox (Vulpes vulpes). We performed dissections and used 3D geometric morphometric approaches to quantify jaw shape in 68 foxes. We used a static lever model and bite force estimates were compared with in vivo measurements of 10 silver foxes. Our results show strong relationships exist between cranial and mandible shape, and between cranial or mandible shape on the one hand and muscles or estimated bite force on the other hand, confirming the strong integration of the bony and muscular components of the jaw system. These strong relationships are strongly driven by size. The functional links between shape and estimated bite force are stronger for the mandible, which probably reflects its greater specialisation towards biting. We then compared our results with data previously obtained for dogs (Canis lupus familiaris) to investigate the effect of domestication. Foxes and dogs differ in skull shape and muscle physiological cross-sectional area (PCSA). They show a similar amount of morphological variation in muscle PCSA, but foxes show lower variation in cranial and mandible shape. Interestingly, the patterns of covariation are not stronger in foxes than in dogs, suggesting that domestication did not lead to a disruption of the functional links of the jaw system.

scholarly journals Borna Disease Virus Infection, a Human Mental-Health Risk

2003 ◽  
Vol 16 (3) ◽  
pp. 534-545 ◽  
Author(s):  
Liv Bode ◽  
Hans Ludwig
Keyword(s):  
Disease Virus ◽  
Enzyme Linked Immunosorbent Assay ◽  
Diagnostic Systems ◽  
Cross Sectional ◽  
Borna Disease Virus ◽  
Pros And Cons ◽  
The Impact ◽  
Borna Disease

SUMMARY This article focuses on human Borna disease virus (BDV) infections, most notably on the development of valid diagnostic systems, which have arisen as a major research issue in the past decade. The significance of a novel modular triple enzyme-linked immunosorbent assay that is capable of specifically measuring anti-BDV antibodies as well as major structural proteins N (p40) and P (p24) in the blood, either as free antigens in the plasma or as antibody-bound circulating immune complexes (CICs), is explained. The impact of CICs and plasma antigen, which indicate periods of antigenemia in the course of BDV infection, along with other infection markers that are still in use is discussed. The review further provides new insight into possible links of BDV to human diseases, summarizing cross-sectional and longitudinal data which correlate acute depression with the presence and amount of antigen and CICs. Moreover, BDV prevalence in healthy people is reevaluated, suggesting that this was previously underestimated. Antiviral efficacy of amantadine, in vivo and in vitro, is outlined as well, with emphasis on wild-type (human and equine) versus laboratory strains. Finally, the pros and cons of the association of BDV with human disease, as detailed in the literature, are critically discussed and related to our data and concepts. This article supports existing correlative evidence for a pathogenic role of BDV infection in particular human mental disorders, in analogy to what has been proven for a variety of animal species.

scholarly journals On the Impact of Vessel Wall Stiffness on Quantitative Flow Dynamics in a Synthetic Model of the Thoracic Aorta

2021 ◽  
Author(s):  
Judith Zimmermann ◽  
Michael Loecher ◽  
Fikunwa Kolawole ◽  
Kathrin Bäumler ◽  
Kyle Gifford ◽  
...  
Keyword(s):  
Thoracic Aorta ◽  
Temporal Resolution ◽  
Aortic Wall ◽  
Predictive Marker ◽  
Flow Dynamics ◽  
4D Flow ◽  
Cross Sectional ◽  
Wall Stiffness ◽  
The Impact

Abstract Aortic wall stiffening is a predictive marker for morbidity in hypertensive patients. Arterial pulse wave velocity (PWV) correlates with the level of stiffness and can be derived using non-invasive 4D-flow magnetic resonance imaging (MRI). The objectives of this study were twofold: to develop subject-specific thoracic aorta models embedded into an MRI-compatible flow circuit operating under controlled physiological conditions; and to evaluate how a range of aortic wall stiffness impacts 4D-flow-based quantification of hemodynamics, particularly PWV. Three aorta models were 3D-printed using a novel photopolymer material at two compliant and one nearly rigid stiffnesses and characterized via tensile testing. Luminal pressure and 4D-flow MRI data were acquired for each model and cross-sectional net flow, peak velocities, and PWV were measured. In addition, the confounding effect of temporal resolution on all metrics was evaluated. Stiffer models resulted in increased systolic pressures (112, 116, and 133 mmHg), variations in velocity patterns, and increased peak velocities, peak flow rate, and PWV (5.8 to 7.3 m/s). Lower temporal resolution (20 ms down to 62.5 ms per image frame) impacted estimates of peak velocity and PWV (7.31 down to 4.77 m/s). Using compliant aorta models is essential to produce realistic flow dynamics and conditions that recapitulated in vivo hemodynamics.

scholarly journals Bite force and its relationship to jaw shape in domestic dogs

2020 ◽  
Vol 223 (16) ◽  
pp. jeb224352 ◽  
Author(s):  
Colline Brassard ◽  
Marilaine Merlin ◽  
Claude Guintard ◽  
Elodie Monchâtre-Leroy ◽  
Jacques Barrat ◽  
...  
Keyword(s):  
Morphological Variability ◽  
Three Dimensional ◽  
Biomechanical Model ◽  
Bite Force ◽  
Domestic Dogs ◽  
Temporal Muscle ◽  
Molar Teeth ◽  
Mandible Shape ◽  
Force Variation

ABSTRACTPrevious studies based on two-dimensional methods have suggested that the great morphological variability of cranial shape in domestic dogs has impacted bite performance. Here, we used a three-dimensional biomechanical model based on dissection data to estimate the bite force of 47 dogs of various breeds at several bite points and gape angles. In vivo bite force for three Belgian shepherd dogs was used to validate our model. We then used three-dimensional geometric morphometrics to investigate the drivers of bite force variation and to describe the relationships between the overall shape of the jaws and bite force. The model output shows that bite force is rather variable in dogs and that dogs bite harder on the molar teeth and at lower gape angles. Half of the bite force is determined by the temporal muscle. Bite force also increased with size, and brachycephalic dogs showed higher bite forces for their size than mesocephalic dogs. We obtained significant covariation between the shape of the upper or lower jaw and absolute or residual bite force. Our results demonstrate that domestication has not resulted in a disruption of the functional links in the jaw system in dogs and that mandible shape is a good predictor of bite force.

scholarly journals On the impact of vessel wall stiffness on quantitative flow dynamics in a synthetic model of the thoracic aorta

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Judith Zimmermann ◽  
Michael Loecher ◽  
Fikunwa O. Kolawole ◽  
Kathrin Bäumler ◽  
Kyle Gifford ◽  
...  
Keyword(s):  
Thoracic Aorta ◽  
Temporal Resolution ◽  
Aortic Wall ◽  
Predictive Marker ◽  
Flow Dynamics ◽  
4D Flow ◽  
Cross Sectional ◽  
Wall Stiffness ◽  
The Impact

AbstractAortic wall stiffening is a predictive marker for morbidity in hypertensive patients. Arterial pulse wave velocity (PWV) correlates with the level of stiffness and can be derived using non-invasive 4D-flow magnetic resonance imaging (MRI). The objectives of this study were twofold: to develop subject-specific thoracic aorta models embedded into an MRI-compatible flow circuit operating under controlled physiological conditions; and to evaluate how a range of aortic wall stiffness impacts 4D-flow-based quantification of hemodynamics, particularly PWV. Three aorta models were 3D-printed using a novel photopolymer material at two compliant and one nearly rigid stiffnesses and characterized via tensile testing. Luminal pressure and 4D-flow MRI data were acquired for each model and cross-sectional net flow, peak velocities, and PWV were measured. In addition, the confounding effect of temporal resolution on all metrics was evaluated. Stiffer models resulted in increased systolic pressures (112, 116, and 133 mmHg), variations in velocity patterns, and increased peak velocities, peak flow rate, and PWV (5.8–7.3 m/s). Lower temporal resolution (20 ms down to 62.5 ms per image frame) impacted estimates of peak velocity and PWV (7.31 down to 4.77 m/s). Using compliant aorta models is essential to produce realistic flow dynamics and conditions that recapitulated in vivo hemodynamics.

scholarly journals Dorsoventral polarity directs cell responses to migration track geometries

2020 ◽  
Vol 6 (31) ◽  
pp. eaba6505
Author(s):  
Emily O. Wisniewski ◽  
Panagiotis Mistriotis ◽  
Kaustav Bera ◽  
Robert A. Law ◽  
Jitao Zhang ◽  
...  
Keyword(s):  
Imaging Techniques ◽  
Myosin Ii ◽  
Cross Sectional ◽  
Dorsoventral Polarity ◽  
Rhoa Activity ◽  
Cell Responses ◽  
Aspect Ratios ◽  
The Impact

How migrating cells differentially adapt and respond to extracellular track geometries remains unknown. Using intravital imaging, we demonstrate that invading cells exhibit dorsoventral (top-to-bottom) polarity in vivo. To investigate the impact of dorsoventral polarity on cell locomotion through different confining geometries, we fabricated microchannels of fixed cross-sectional area, albeit with distinct aspect ratios. Vertical confinement, exerted along the dorsoventral polarity axis, induces myosin II–dependent nuclear stiffening, which results in RhoA hyperactivation at the cell poles and slow bleb-based migration. In lateral confinement, directed perpendicularly to the dorsoventral polarity axis, the absence of perinuclear myosin II fails to increase nuclear stiffness. Hence, cells maintain basal RhoA activity and display faster mesenchymal migration. In summary, by integrating microfabrication, imaging techniques, and intravital microscopy, we demonstrate that dorsoventral polarity, observed in vivo and in vitro, directs cell responses in confinement by spatially tuning RhoA activity, which controls bleb-based versus mesenchymal migration.

scholarly journals The relationship between head shape, head musculature and bite force in caecilians (Amphibia: Gymnophiona)

2021 ◽  
Author(s):  
Aurélien Lowie ◽  
Barbara De Kegel ◽  
Mark Wilkinson ◽  
John Measey ◽  
James C. O'Reilly ◽  
...  
Keyword(s):  
Bite Force ◽  
Temporal Region ◽  
Head Shape ◽  
Skull Shape ◽  
Form And Function ◽  
Feeding Mechanics ◽  
Mandible Shape ◽  
And Function ◽  
The Relationship

Caecilians are enigmatic limbless amphibians that, with a few exceptions all have an at least partly burrowing lifestyle. Although it has been suggested that caecilian evolution resulted in sturdy and compact skulls as an adaptation to their head-first burrowing habits, no relationship between skull shape and burrowing performance has been demonstrated to date. However, the unique dual jaw-closing mechanism and the osteological variability of their temporal region suggest a potential relationship between skull shape and feeding mechanics. Here, we explored the relationships between skull shape, head musculature, and in vivo bite forces. Although there is a correlation between bite force and external head shape, no relationship between bite force and skull shape could be detected. Whereas our data suggest that muscles are the principal drivers of variation in bite force, the shape of the skull is constrained by factors other than demands for bite force generation. However, a strong covariation between the cranium and mandible exists. Moreover, both cranium and mandible shape covary with jaw muscle architecture. Caecilians show a gradient between species with a long retroarticular process associated with a large and pennate-fibered m. interhyoideus posterior and species with a short process but long and parallel-fibered jaw adductors. Our results demonstrate the complexity of the relationship between form and function of this jaw system. Further studies that focus on factors such as gape distance or jaw velocity will be needed in order to fully understand the evolution of feeding mechanics in caecilians.

scholarly journals Laquinimod dampens IL-1β signaling and Th17-polarizing capacity of monocytes in patients with MS

2020 ◽  
Vol 8 (1) ◽  
pp. e908
Author(s):  
Sinah Engel ◽  
Valérie Jolivel ◽  
Stefan H.-P. Kraus ◽  
Morad Zayoud ◽  
Karolina Rosenfeld ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
T Cells ◽  
Intracellular Cytokine Staining ◽  
Cross Sectional Study ◽  
Cross Sectional ◽  
Activation Markers ◽  
Messenger Ribonucleic Acid ◽  
The Impact

ObjectiveTo assess the impact of laquinimod treatment on monocytes and to investigate the underlying immunomodulatory mechanisms in MS.MethodsIn this cross-sectional study, we performed in vivo and in vitro analyses of cluster of differentiation (CD14+) monocytes isolated from healthy donors (n = 15), untreated (n = 13), and laquinimod-treated patients with MS (n = 14). Their frequency and the expression of surface activation markers were assessed by flow cytometry and the viability by calcein staining. Cytokine concentrations in the supernatants of lipopolysaccharide (LPS)-stimulated monocytes were determined by flow cytometry. The messenger ribonucleic acid (mRNA) expression level of genes involved in cytokine expression was measured by quantitative PCR. The LPS-mediated nuclear factor kappa-light-chain-enhancer of activated B-cell (NF-κB) activation was determined by the quantification of the phosphorylation level of the p65 subunit. Laquinimod-treated monocytes were cocultured with CD4+ T cells, and the resulting cytokine production was analyzed by flow cytometry after intracellular cytokine staining. The interleukin (IL)-17A concentration of the supernatant was assessed by ELISA.ResultsLaquinimod did not alter the frequency or viability of circulating monocytes, but led to an upregulation of CD86 expression. LPS-stimulated monocytes of laquinimod-treated patients with MS secreted less IL-1β following a downregulation of IL-1β gene expression. Phosphorylation levels of the NF-κB p65 subunit were reduced after laquinimod treatment, indicating a laquinimod-associated inhibition of the NF-κB pathway. T cells primed with laquinimod-treated monocytes differentiated significantly less into IL-17A–producing T helper (Th)-17 cells.ConclusionsOur findings suggest that inhibited NF-κB signaling and downregulation of IL-1β expression in monocytes contributes to the immunomodulatory effects of laquinimod and that the impairment of Th17 polarization might mediate its disease-modifying activity in MS.

scholarly journals A serological survey of anthrax in domestic dogs in Zimbabwe: a potential tool for anthrax surveillance

2018 ◽  
Vol 146 (12) ◽  
pp. 1526-1532 ◽  
Author(s):  
N. L. Mukarati ◽  
O. Ndumnego ◽  
H. van Heerden ◽  
D. N. Ndhlovu ◽  
G. Matope ◽  
...  
Keyword(s):  
High Risk ◽  
Strong Association ◽  
Physical Space ◽  
Low Risk ◽  
Domestic Dogs ◽  
Canis Lupus Familiaris ◽  
High Seroprevalence ◽  
Cross Sectional ◽  
Domestic Species ◽  
Risk Areas

AbstractAnthrax is an important disease caused by the bacteriumBacillus anthracisaffecting both domestic and wild animals at the wildlife/livestock interface, defined here as a physical space in which wild and domestic species overlap in range and potentially interact. In endemic regions, sporadic anthrax outbreaks occur, causing significant deaths of both wildlife and livestock and sporadically, humans. However, it may also occur as isolated outbreaks with a few animals affected. Such isolated anthrax outbreaks maybe missed. High seroprevalence among carnivores suggests either regular non-fatal exposure to the pathogen circulating in a given environment, or contact with missed cases through consumption of anthrax carcases. To investigate the relevance of this potential indicator, a cross-sectional study was conducted to determine anthrax seroprevalence in domestic dogs (Canis lupus familiaris)from selected interface and non-interface areas of Zimbabwe with known history of anthrax outbreaks. Based on past anthrax outbreaks in the respective areas, the sites were further classified as high or low risk areas for anthrax outbreaks. Sera were collected from domestic dogs (n= 186) and tested for antibodies againstB. anthracisprotective antigens (PA) using an ELISA test. The overall seroprevalence was 51.6% (96/186; 95% CI 44.2–59.0). Sites from the non-interface areas recorded a significantly (P< 0.001) higher (72.1%) anthrax seroprevalence compared with those from the wildlife –livestock interface (41.5%). The results demonstrated a strong association (χ2= 14.3; OR = 3.2, 1.6 < OR < 6.2,P< 0.001) between anthrax seropositivity and interface type. Low-risk sites (42.5%) had a significantly (P= 0.044) lower seroprevalence compared with high-risk sites (58.5%) but still demonstrated high seroprevalence for areas where anthrax was last reported more than 20 years back. Dogs from Tsholotsho South were more than 90-times (OR = 96.5, 13.5 < OR < 690.8) more likely to be seropositive compared with those from Hwange. The study demonstrated the potential to use domestic dogs as indicators of anthrax in the study areas to survey anthrax circulation in supposed low-risk areas and calls for a redefinition of both low and high risk areas for anthrax in Zimbabwe based on an improved surveillance.

Hair cell changes after cationic stimulation of corti's organ

1989 ◽  
Vol 47 ◽  
pp. 798-799
Author(s):  
Cesar D. Fermin ◽  
Hans-Peter Zenner
Keyword(s):  
Organ Of Corti ◽  
Cross Sectional ◽  
Surface Areas ◽  
High K ◽  
Anatomical Arrangement ◽  
Cell Cytosol ◽  
High Concentrations ◽  
K Concentration ◽  
Cell Changes

Contraction of outer and inner hair cells (OHC&IHC) in the Organ of Corti (OC) of the inner ear is necessary for sound transduction. Getting at HC in vivo preparations is difficult. Thus, isolated HCs have been used to study OHC properties. Even though viability has been shown in isolated (iOHC) preparations by good responses to current and cationic stimulation, the contribution of adjoining cells can not be explained with iOHC preparations. This study was undertaken to examine changes in the OHC after expossure of the OHC to high concentrations of potassium (K) and sodium (Na), by carefully immersing the OC in either artifical endolymph or perilymph. After K and Na exposure, OCs were fixed with 3% glutaraldehyde, post-fixed in osmium, separated into base, middle and apex and embedded in Araldite™. One μm thick sections were prepared for analysis with the light and E.M. Cross sectional areas were measured with Bioquant™ software.Potassium and sodium both cause isolated guinea pig OHC to contract. In vivo high K concentration may cause uncontrolled and sustained contractions that could contribute to Meniere's disease. The behavior of OHC in the vivo setting might be very different from that of iOHC. We show here changes of the cell cytosol and cisterns caused by K and Na to OHC in situs. The table below shows results from cross sectional area measurements of OHC from OC that were exposed to either K or Na. As one would expect, from the anatomical arrangement of the OC, OHC#l that are supported by rigid tissue would probably be displaced (move) less than those OHC located away from the pillar. Surprisingly, cells in the middle turn of the cochlea changed their surface areas more than those at either end of the cochlea. Moreover, changes in surface area do not seem to differ between K and Na treated OCs.

Multidisciplinary team decision is rare and decreasing in percutaneous vascular interventions despite positive impact on in-hospital outcomes

VASA ◽  
2019 ◽  
Vol 48 (3) ◽  
pp. 262-269 ◽  
Author(s):  
Christian-Alexander Behrendt ◽  
Tilo Kölbel ◽  
Thea Schwaneberg ◽  
Holger Diener ◽  
Ralf Hohnhold ◽  
...  
Keyword(s):  
Multidisciplinary Team ◽  
Positive Impact ◽  
Cross Sectional Study ◽  
Invasive Treatment ◽  
Cross Sectional ◽  
Hospital Outcomes ◽  
Vascular Intervention ◽  
Medical Specialties ◽  
Team Decision ◽  
The Impact

Abstract. Background: Worldwide prevalence of peripheral artery disease (PAD) is increasing and peripheral vascular intervention (PVI) has become the primary invasive treatment. There is evidence that multidisciplinary team decision-making (MTD) has an impact on in-hospital outcomes. This study aims to depict practice patterns and time changes regarding MTD of different medical specialties. Methods: This is a retrospective cross-sectional study design. 20,748 invasive, percutaneous PVI of PAD conducted in the metropolitan area of Hamburg (Germany) were consecutively collected between January 2004 and December 2014. Results: MTD prior to PVI was associated with lower odds of early unsuccessful termination of the procedures (Odds Ratio 0.662, p < 0.001). The proportion of MTD decreased over the study period (30.9 % until 2009 vs. 16.6 % from 2010, p < 0.001) while rates of critical limb-threatening ischemia (34.5 % vs. 42.1 %), patients´ age (70 vs. 72 years), PVI below-the-knee (BTK) (13.2 % vs. 22.4 %), and rates of severe TASC C/D lesions BTK (43.2 % vs. 54.2 %) increased (all p < 0.001). Utilization of MTD was different between medical specialties with lowest frequency in procedures performed by internists when compared to other medical specialties (7.1 % vs. 25.7 %, p < 0.001). Conclusions: MTD prior to PVI is associated with technical success of the procedure. Nonetheless, rates of MTD prior to PVI are decreasing during the study period. Future studies should address the impact of multidisciplinary vascular teams on long-term outcomes.

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