Relationships between type of hoof lesion and behavioral signs of lameness in Holstein cows housed in Canadian tiestall facilities

Although foot pain can affect gait, the presence of a hoof lesion may or may not cause the cow to show visible changes in their gait. This can be dependent on the type and severity of the lesion; for example, the presence of a sole ulcer (SU) has been associated with increased gait scores, whereas digital dermatitis (DD) and sole hemorrhage (SH) have not. In tiestall facilities, gait scoring can be difficult to perform. An alternative method, known as stall lameness scoring (SLS), allows observers to assess cattle for lameness while they remain in their stall. Lameness is determined based on behavioral changes in weight bearing and foot positioning, which include: shifting weight, resting a foot, standing on the edge of the stall, and uneven weight bearing when stepping side to side. The aim of this study was to examine relationships between hoof lesions and these behavioral indicators. A total of 557 observations of SLS and corresponding hoof trimming records, collected during routine trimming events on 7 tiestall herds, were obtained. Trimming was performed by 2 trained hoof trimmers with good agreement on lesion identification, based on quizzes taken at the beginning and mid-way through the study. To ensure trimming had no effect on the behavioral indicators observed, SLS was always performed by a trained observer before trimming. Behavioral indicators focused on the hind limbs only; therefore, the analysis was confined to hind limb lesions using logistic regression to detect the presence of hoof lesion based on observations made during SLS. Seventy-five percent of observed cows had no SLS behavioral indicators, whereas, 11, 12, and 1% had 1, 2, and 3 behavioral indicators, respectively. At least one hind limb lesion was noted during trimming in 19% of cows, with the most common lesions being DD (7%), SU (6%), and SH (4%). A cow that was observed resting one foot and bearing weight unevenly when moving side to side had higher odds of having a hind limb hoof lesion than a cow not displaying these behaviors. When looking at specific hoof lesions, a cow observed resting one limb and bearing weight unevenly had higher odds of having a SU compared with those not displaying these behaviors. A cow observed shifting their weight from one foot to another had higher odds of having SH, and a cow observed bearing weight unevenly had higher odds of DD. Behavioral indicators in weight bearing and foot positioning can help identify cows in tiestalls with hind limb hoof lesions. Producers could routinely observe their cattle for these indicators to assist in the identification of cows that may require treatment. This could help reduce the duration of clinical lameness through earlier intervention.

Is primary graft failure still a challenge in time of venoarterial extracorporeal membrane oxygenation?

Introduction

Primary graft failure (PGF) is the leading cause of early mortality after heart transplantation (HT). Its increasing incidence during the last decade may be triggered by the disbalance between receptors and donors that forces the acceptance of suboptimal organs.

Purpose

The aim of our work was to analyse the mechanical circulatory support (MCS) with VA-ECMO in refractory to inotropes PGF and determinate its impact in terms of graft function recovery and survival.

Methods

A retrospective study, analyzing our database of circulatory assist devices between 2009 and 2019. During this period, 252 devices have been implanted (154 ECMOs and 98 ventricular assist devices) and 201 patients have received a HT. We describe the characteristics and evolution of all PGF cases managed with VA-ECMO.

Results

Thirty nine patients (19.4%) developed PGF, defined as significant left, right or biventricular systolic dysfunction in the first 24 hours after HT, associated with hemodynamic instability and requiring high dose of inotropes, intra-aortic balloon pump (IABP) or VA-ECMO. Twenty two cases (56.4%) underwent a VA-ECMO implantation by peripheral cannulation as a bridge to recovery.

The median age was 50.8 (44.3–57.3) years and 77% were male. Biventricular dysfunction was observed in 50% and isolated right ventricular dysfunction in the remaining 50%. At the time of implantation, 59% had IABP and the median of inotropic score was 24 (8–40). Two complications occurred during implantation (one because of a complex vascular access and one due to a malposition of the venous cannula). Anticoagulation was started after a median of 19 hours (10–28; 59% sodic heparin and 36% bivalirudin).

The median support duration was 6.2 days (3–9.2). Graft function was recovered in 90%, making it possible to withdraw the device successfully in 82% of patients. The remaining 18% deceased during the support (2 because of multiorgan failure and 2 due to absence of function recovery).The median hospital length of stay was 63 days (33–93) and hospital and 1-year survival was 68.1%.

Conclusion

The support with VA-ECMO allowed graft function recovery in 90% of severe PGF cases, with a similar survival rate to other centres with MCS. In a scenario with a mortality rate superior to 50%, the MCS programs have managed to increase survival, avoid retransplantation in times of donor shortage and handle the use of suboptimal donors with better chances of success.

Funding Acknowledgement

Type of funding source: None

Trajectories of functioning in bipolar disorders: A longitudinal study in the FondaMental Advanced Centers of Expertise in Bipolar Disorders cohort

OBJECTIVE

We aimed at identifying distinct trajectories of functioning and at describing their respective clinical characteristics in a cohort of individuals with bipolar disorders.

METHODS

We included a sample of 2351 individuals with bipolar disorders who have been followed-up to 3 years as part as the FondaMental Advanced Centers of Expertise in Bipolar Disorders cohort. Global functioning was measured using the Functioning Assessment Short Test. We used latent class mixed models to identify distinct longitudinal trajectories of functioning over 3 years. Multivariable logistic regression models were used to identify the baseline factors that were associated with the membership to each trajectory of functioning.

RESULTS

Three distinct trajectories of functioning were identified: (1) a majority of individuals (72%) had a stable trajectory of mild functional impairment, (2) 20% of individuals had a stable trajectory of severe functional impairment and (3) 8% of individuals had a trajectory of moderate functional impairment that improved over time. The membership to a trajectory of stable severe versus stable mild functional impairment was associated with unemployment, a higher number of previous hospitalizations, childhood maltreatment, a higher level of residual depressive symptoms, higher sleep disturbances, a higher body mass index and a higher number of psychotropic medications being prescribed at baseline. The model that included these seven factors led to an area under the curve of 0.85.

CONCLUSION

This study enabled to stratify individuals with bipolar disorders according to three distinct trajectories of functioning. The results regarding the potential determinants of the trajectory of severe functional impairment needs to be replicated in independent samples. Nevertheless, these potential determinants may represent possible therapeutic targets to improve the prognosis of those patients at risk of persistent poor functioning.

Social Network Organization, Structure, and Patterns of Influence Within a Community of Transgender Women in Lima, Peru: Implications for Biomedical HIV Prevention

Understanding social network structures can contribute to the introduction of new HIV prevention strategies with socially marginalized populations like transgender women (TW). We conducted 20 semi-structured interviews and four focus groups (n = 32) with TW from selected social networks in Lima, Peru between May and July, 2015. Participants described layers of social influence from diverse actors in their social networks. The majority identified a close relative as their primary social support, with whom they confided secrets but avoided issues of transgender identity, sexuality, and sex work. Participants described close circles of TW friends with whom they shared information about gender identity, body modification, and sexual partners, but avoided issues like HIV. Community leadership included political leaders (who advocated for transgender rights) as well as social leaders (who introduced TW to hormone therapy, body modification, and commercial sex). Detailed analysis of TW social networks can contribute to implementation and acceptability of new HIV prevention technologies.

Molecular detection of Bartonella in fleas (Hexapoda, Siphonaptera) collected from wild rodents (Cricetidae, Sigmodontinae) from Argentina

Bartonella are facultative intracellular Gram-negative bacteria, transmitted mainly by hematophagous arthropods, and the rodents act as a natural reservoir. Different species of Bartonella associated with rodents have been implicated as causing human disease. Studies from Argentina are scarce and no Bartonella from fleas have been reported previously. The present study investigated the presence of Bartonella spp. in fleas associated with sigmodontine rodents in four localities of the Santa Cruz Province, Argentina. In total, 51 fleas (four species) were analysed of which 41.2% were found to be positive for the gltA gene fragment via a nested polymerase chain reaction. All positive fleas were of the species Neotyphloceras crackensis from three different localities. Eight of the 21 amplified samples were sequenced, and the presence of three different genotypes was detected with an identity of 95.5-98.8% amongst themselves. Bartonella genotypes from American rodents and rodent fleas were recovered in a monophyletic group. Similarly, most of the Peruvian and all Argentinean variants constitute a natural group sister of the American remainder. The importance of the Bartonella spp. with respect to public health is unknown, although future studies could provide evidence of the possible involvement of N. crackensis in the Bartonella transmission cycles.

P3509Leukocyte derived tumour necrosis factor modulates cardiac function in health and disease

Purpose

Tumour necrosis factor alpha (TNFα) regulates both normal and pathophysiological cardiac function. The regulatory role of TNFα derived from different sources (leukocyte versus cardiac cells) in cardiac physiology is unclear. Deficiency of iRhom2 protein prevents circulating immune cells from shedding TNFα (and CD62L, an adhesion molecule essential for effective immune function). Here we investigated the role of leukocyte derived TNFα in constitutive cardiac function and after cardiac injury.

Methods

Adult iRhom2-deficient mice (KO) and wildtype (Wt) littermates, of both genders, underwent echocardiography to assess cardiac physiologic function at least 1 week before receiving a single dose of isoproterenol (300mg/kg IP) to induce cellular death in 10% of the cardiomyoctes [1]. Cardiac echocardiography was repeated 36 hours after isoproterenol. Peripheral and cardiac-resident leukocytes were phenotyped by flow cytometry and molecular markers of cardiac stress (atrial and brain natriuretic protein, ANP, BNP) and inflammation (NFkB) were quantified using RT-PCR.

Results

Peripheral leukocytes from iRhom2 KO mice failed to shed CD62L in response to isoproterenol induced cardiac injury (e.g. neutrophils CD62L Mean Fluorescence Intensity KO: 9149±4616, Wt: 972±558, p<0.0001, n=9). iRhom2-deficient mice had higher cardiac output at baseline (KO 23±2 mL/min, n=11) compared to their wildtype littermates (Wt 18±3 mL/min, n=9). Wild type mice increased contractility after isoproterenol (Wt ejection fraction: baseline 60±6%, isoproterenol 68±6%, n=8) whilst iRhom2-deficient mice were unable to (KO ejection fraction: baseline 66±9%, isoproterenol 61±5%, n=8). ANP and BNP mRNA were elevated in ventricular tissue of iRhom2-knockout mice after isoproterenol, when compared to naïve tissue (ANP 2ΔCT: 3x increase, BNP 2ΔCT: 1.6x increase) whereas only ANP was elevated in wildtypes (ANP 2ΔCT: 2.7x increase, BNP 2ΔCT: 0.9x increase). No difference in immune cell infiltration of ventricular cardiac tissue was observed (number of CD45+ cells KO: 3014±3482, Wt: 2555±1411, p=0.7, n=9) NFkB mRNA was upregulated at baseline (2ΔCT KO: 0.2±0.08, Wt: 0.1±0.09) suggesting constitutive cardiac inflammation in iRhom2-deficient mice.

Conclusions

Inability to shed CD62L and TNFα is associated with constitutive and acquired cardiac dysfunction in iRhom2-deficient mice. These data support the hypothesis that leukocyte-derived TNFα is required for maintaining cardiac function in health and disease.

Acknowledgement/Funding

National Institute of Academic Anaesthesia/Royal College of Anaesthetists/British Journal of Anaesthesia; National Institute for Health Research

P4684Differential right ventricular adaptation patterns to chronic pressure overload

Background

Right ventricular (RV) dysfunction is the most important prognostic factor in chronic pulmonary hypertension (PH), but its underlying mechanisms are unknown. Clinical observation and prior experimental work suggest that RV pressure overload is not the only cause since the degree of RV adaptation varies with similar RV end-systolic pressures.

Purpose

Our aim was to characterize serial RV adaptation by cardiac magnetic resonance (CMR) in 3 different experimental large-animal models of increased afterload: a model of chronic postcapillary PH, a model of PH secondary to systemic-to-pulmonary shunt and a model of mechanical RV pressure overload (generated by pulmonary artery [PA] banding).

Methods

Four-week old piglets underwent pulmonary vein banding surgery to generate the chronic postcapillary PH model (n=20), aorto-pulmonary shunt (n=6), PA banding (n=7) or sham operation (n=7). They were followed up monthly with CMR and right heart catheterization (RHC). All procedures followed the “Principles of laboratory animal care”. Comparison of continuous variables among groups was performed with Mann-Whitney U test.

Results

Animals with either postcapillary PH or PH secondary to aorto-pulmonary shunt presented significant RV dilatation, hypertrophy and dysfunction that was maintained during follow-up (median RV end-systolic volume [RVESV]=32.6 ml/m2 for postcapillary PH and 32.6 ml/m2 for shunt vs. 16.1 ml/m2 in sham controls; median RV ejection fraction [RVEF]=61.5% for postcapillary PH and 60.5% for shunt vs. 69.6% in sham controls at the end of follow-up). Animals with PA banding also presented with significant RV dilatation and hypertrophy at the first month follow-up, but unlike all other groups, they developed reverse RV remodeling from the second month onwards and maintained normal RV volumes and RVEF values until the end of follow-up despite having severe RV hypertrophy (RV mass 22.6 g/m2 in PA banding vs. 16.1 g/m2 in controls at the 4th month follow-up; Figure).

CMR parameters (median values).

Conclusion

In PH there is a maladaptive RV hypertrophy that is not present in a model of progressive RV pressure overload without alterations of the pulmonary circulation. Increased RV pressure overload alone does not fully explain PH-associated RV dysfunction. Further research is needed to clarify the underlying mechanisms of adaptive and maladaptive hypertrophy in PH.

Acknowledgement/Funding

The CNIC is supported by the Ministerio de Ciencia, Innovaciόn y Universidades and the Pro CNIC Foundation, and is a Severo Ochoa Center of Excellence