Antimicrobial and Antiproliferative Coatings for Stents in Veterinary Medicine-State of the Art and Perspectives

Microbial colonization in veterinary stents poses a significant and concerning issue in veterinary medicine. Over time, these pathogens, particularly bacteria, can colonize the stent surfaces, leading to various complications. Two weeks following the stent insertion procedure, the colonization becomes observable, with the aggressiveness of bacterial growth directly correlating with the duration of stent placement. Such microbial colonization can result in infections and inflammations, compromising the stent's efficacy and, subsequently, the animal patient's overall well-being. Managing and mitigating the impact of these pathogens on veterinary stents is a crucial challenge that veterinarians and researchers are actively addressing to ensure the successful treatment and recovery of their animal patients. In addition, irritation of the tissue in the form of an inserted stent can lead to overgrowth of granulation tissue, leading to the closure of the stent lumen, as is most often the case in the trachea. Such serious complications after stent placement require improvements in the procedures used to date. In this review, antibacterial or antibiofilm strategies for several stents used in veterinary medicine have been discussed based on the current literature and the perspectives have been drawn. Various coating strategies such as coating with hydrogel, antibiotic, or other antimicrobial agents have been reviewed.

Effect of low-dose hydrocortisone and inhaled nitric oxide on inflammatory mediators and local pulmonary metalloproteinases activity in LPS-induced sepsis in piglets

Hospital mortality in sepsis varies between 30-45%. It has been shown that administration of inhaled nitric oxide (iNO) and intravenous corticosteroid in a porcine endotoxemia model attenuated the systemic inflammatory response. We explored the anti-inflammatory effect of a double-treatment strategy (iNO + low-dose steroid) on the lungs in a long-term porcine endotoxic shock model. As metalloproteinases (MMPs) are involved in the initiation of multiple organ dysfunction in septic shock, we evaluated the influence of this combination therapy on MMP2 and MMP9 activity and proIL-1β maturation. A shock-like condition was established in 23 animals by continuous infusion of E. coli lipopolysaccharide (LPS) for 10 h. Then the animals were observed for 10 h. Twelve pigs received iNO and hydrocortisone (iNO treatment started 3 h after the initial LPS infusion and continued until the end of the experiment). Eleven pigs were controls. Pigs treated with iNO and hydrocortisone displayed less inflammatory infiltrates in the lungs than the controls and a lower level of IL-1β. The proMMP2 was significantly decreased in the iNO and hydrocortisone group. The amount of an active MMP9 (~ 60 kDa) was decreased in the iNO and hydrocortisone group. Total gelatinolytic activity was lower in the iNO and hydrocortisone group. Reduced MMP activity was accompanied by a 2.5-fold decrease of the active IL-1β form (17 kDa) in the pulmonary tissue of iNO combined with hydrocortisone exposed pigs. We demonstrated that in a porcine endotoxemia model the NO inhalation combined with intravenous hydrocortisone led to the attenuation of the inflammatory cascade induced by bacterial LPS. The decrease in pulmonary MMPs activities was accompanied by reduced proIL-1β processing.

Stents in Veterinary Medicine

Stenting in veterinary medicine has been a rapidly growing method of interventional surgery for several years. This procedure is usually performed in the respiratory and urinary tracts, but there are cases of stenting of blood vessels or gastrointestinal structures. It is based on maintaining the permeability of a given tubular structure, thus allowing the passage of gas or liquid. This procedure is often performed as a first-line treatment in situations where pharmacological agents do not work and as an alternative method, often cheaper than the classically performed ones. There are also cases where stenting is used as a palliative treatment, e.g., to enable defecation in colonic obstruction due to tumour infiltration of the colon wall. Stenting is often a life-saving or comfort-improving procedure for animals, but one should also be aware of possible postoperative complications and be prepared for any adversity. For this reason, this review provides an insight into the current knowledge in veterinary medicine about stenting and the consequences associated with this procedure.

Evaluation of the diagnostic value of the renal resistive index as a marker of the subclinical development of cardiorenal syndrome in MMVD dogs

Introduction:

Myxomatous mitral valve disease (MMVD) in dogs inevitably causes renal dysfunction. These interactions are known as the cardiorenal syndrome (CRS). The main aims of the study were to evaluate whether renal resistive index (RRI) may be useful as a non-invasive marker in subclinical stage of kidney injury in dogs with MMVD and to compare RRI with SDMA and Cyst C.

Methods:

Forty-four dogs were divided into two groups: control—15 healthy dogs and the heart group—29 dogs with MMVD (ACVIM class Cc). Study protocol included: anamnesis, clinical examination, electrocardiography, echocardiography, chest radiography, abdominal ultrasonography with measurements of the renal resistive index (RRI), urine, and blood analysis.

Results:

The RRI in the heart group was significantly higher 0.725 ± 0.035 versus control group 0.665 ± 0.028 (p < 0.00085). The RRI cut-off point in dogs with stable chronic heart failure (CHF) under 8 years is 0.775, in older 0.64. RRI was similar in MMVD dogs treated with ACE-I + furosemide and dogs treated ACE-I + torasemide + pimobendan + spironolactone. There was no correlation between RRI and SDMA or Cyst C.

Conclusion:

RRI is more sensitive than creatinine, SDMA and Cyst C to reveal kidney injury in MMVD dogs class Cc younger than 8 years.

The Influence of Diet on Oxidative Stress and Inflammation Induced by Bacterial Biofilms in the Human Oral Cavity

The article is a concise compendium of knowledge on the etiology of pathogenic microorganisms of all complexes causing oral diseases. The influence of particular components of the diet and the role of oxidative stress in periodontal diseases were described. The study investigated the bacteriostatic effect of the diet of adults in in vivo and in vitro tests on the formation of bacterial biofilms living in the subgingival plaque, causing diseases called periodontitis. If left untreated, periodontitis can damage the gums and alveolar bones. Anaerobic bacteria, called periopathogens or periodontopathogens, play a key role in the etiopathogenesis of periodontitis. The most important periopathogens of the oral microbiota are bacteria of all complexes, including the red complex. The obtained results suggest the possibility of using a specific diet in the prevention and treatment of periodontal diseases-already treated as a disease of civilization. The quoted article is an innovative compilation of knowledge on this subject and it can be a valuable source of knowledge for professional hygienists, dentists, peridontologists, dentistry students and anyone who cares about proper oral hygiene. The obtained results suggest the possibility of using this type of diet in the prophylaxis of the oral cavity in order to avoid periodontitis.

Effects of Long-Term High-Fat Diet and Its Reversal on Lipids and Lipoproteins Composition in Thoracic Duct Lymph in Pigs

Background

This study was carried out to evaluate the effects of a long-term high-fat diet on lipids and lipoproteins composition in thoracic duct lymph in pigs.

Material/Methods

We examined lymph taken from the thoracic duct from 24 female white sharp-ear pigs, divided into 3 experimental groups fed different diets for 12 months: (a) the control group, fed the standard balanced diet; (b) the HFD group, fed an unbalanced, high-fat diet, and (c) the reversal diet group (RD), fed an unbalanced, high-fat diet for 9 months and then a standard balanced diet for 3 months.

Results

Lymph analysis after 12 months of fixed diets revealed significantly higher concentration of proteins in the HFD group in comparison to the control and RD groups. Examination of lymph lipoproteins fractions showed that the high-fat diet in the HFD group in comparison to control group caused an increase in cholesterol, phospholipids, and proteins content within HDL and chylomicrons. There were also more proteins within HDL in the HFD group in comparison to the RD group and more triglycerides within chylomicrons in the HFD group in comparison to the control group.

Conclusion

A long-term high-fat diet resulted in changed structure of HDL and chylomicrons in the thoracic duct lymph. Alterations in HDL composition suggest that a high-fat diet enhances reverses cholesterol transport. Changes in chylomicrons structure show the adaptation to more intense transport of dietary fat from the intestine to the liver under the influence of a high-fat diet. Reversal to a standard balanced diet had the opposite effects.

Evaluation of Tryptic Podocin Peptide in Urine Sediment Using LC-MS-MRM Method as a Potential Biomarker of Glomerular Injury in Dogs with Clinical Signs of Renal and Cardiac Disorders

The early asymptomatic stage of glomerular injury is a diagnostic challenge in the course of renal and extra-renal disease, e.g., heart insufficiency. It was found that podocin, a podocyte-specific protein present in the urine, may serve as a biomarker in the diagnosis of glomerular disease in humans and animals including glomerulonephritis, glomerulosclerosis, amyloidosis, or nephropathy. Therefore, there is a need of development of the sensitive and straightforward method of urinary podocin identification. In this work, we report our extended research under the glomerular injury investigation in dogs by application of clinical examination and LC-MS-MRM method in the identification of canine podocin in urine samples. The LC-MS-MRM method is based on the identification of podocin tryptic peptide with the ²¹⁸H-AAEILAATPAAVQLR-OH²³² sequence. The model peptide was characterized by the highest ionization efficiency of all the proposed model podocin tryptic peptides in a canine urine sediment according to the LC-MS/MS analysis. The obtained results revealed the presence of the model peptide in 40.9% of dogs with MMVD (active glomerular injury secondary to heart disease = cardiorenal syndrome-CRS) and 33.3% dogs with chronic kidney disease. The potential applicability of the developed methodology in the analysis of podocin in canine urine sediments was confirmed.

Transcriptomic Alterations of the Aortic Intima and Media in Long-term High-fat Diet Fed Pigs and Its Reversal (P15-010-19)

Objectives

We have previously shown that 12 months (mo.) high-fat diet (HFD) in pigs led to pathophysiological alterations, incl. fattening and increased femoral artery intima-media-thickness, which were partly reversed after 3 mo. return to control diet (Zabek et al., PLoS One 2017). The aim of this study was to decipher underlying mechanism of action of these dietary interventions on the arteries by nutrigenomics analyses of intima and media of aorta.

Methods

32 female pigs were divided into 3 groups: Control diet (CD) for 12 mo; HFD for 12 mo; 3) Reversal diet group (RD): HFD for 9 mo followed by CD for 3 mo After 12 mo animals were killed and abdominal aorta collected. RNA was isolated from aorta intima and media for whole genome microarray analyses followed by bioinformatics analyses.

Results

HFD compared to CD group significantly affected gene expression profile in intima with genes belonging to the chemotaxis, inflammation or endothelial permeability. RD induced gene expression profile was distinct from the CD group. This suggests that 3 mo of reversal to CD is not sufficient to correct gene expression changes induced by HFD. Comparison of RD profile with that of HFD group revealed a group of genes with opposite expression, e.g., genes regulating inflammation, toll-like cell signaling pathway or cytoskeleton organization involved in the regulation of cell permeability. This suggests that return to the RD only partly restored gene expression alterations due to the HFD. Significant changes in expression of genes in media following HFD were also observed, such as genes involved in cytoskeleton organization and migration MAPK signaling. As for intima, the expression profile of media of pigs on RD was different on that of these on CD diet. Compared to HFD, a group of genes involved in PI3K or MAPK pathways presented opposite expression suggesting that RD can partly correct the changes in genomic effect induced by HFD.

Conclusions

This study revealed genomic modifications induced by long-term HFD consumption on arterial intima and media. The return to normal diet for 3 mo was not sufficient to counteract the genomic effect of long-term HFD consumption.

Funding Sources

WROVASC Integrated Cardiovascular Centre, co-financed by the European Regional Development Fund.

Normal Values for Heart Electrophysiology Parameters of Healthy Swine Determined on Electrophysiology Study

BACKGROUND

Swine are a well-recognized animal model for human cardiovascular diseases. Despite the widespread use of porcine model in experimental electrophysiology, still no reference values for intracardiac electrical activity and conduction parameters determined during an invasive electrophysiology study (EPS) have been developed in this species thus far.

OBJECTIVES

The aim of the study was to develop a set of normal values for intracardiac electrical activity and conduction parameters determined during an invasive EPS of swine.

MATERIAL AND METHODS

The study included 36 healthy domestic swine (24-40 kg body weight). EPS was performed under a general anesthesia with midazolam, propofol and isoflurane. The reference values for intracardiac electrical activity and conduction parameters were calculated as arithmetic means ± 2 standard deviations.

RESULTS

The reference values were determined for AH, HV and PA intervals, interatrial conduction time at its own and imposed rhythm, sinus node recovery time (SNRT), corrected sinus node recovery time (CSNRT), anterograde and retrograde Wenckebach points, atrial, atrioventricular node and ventricular refractory periods. No significant correlations were found between body weight and heart rate of the examined pigs and their electrophysiological parameters.

CONCLUSIONS

The hereby presented reference values can be helpful in comparing the results of various studies, as well as in more accurately estimating the values of electrophysiological parameters that can be expected in a given experiment.

Ventricular Effective Refraction Period and Ventricular Repolarization Analysis in Experimental Tachycardiomyopathy in Swine

BACKGROUND

Swine are recognized animal models of human cardiovascular diseases. However, little is known on the CHF-associated changes in the electrophysiological ventricular parameters of humans and animals.

OBJECTIVES

The aim of this study was to analyze changes in the durations of ventricular effective refraction period (VERP), QT and QTc intervals of pigs with chronic tachycardia-induced tachycardiomyopathy (TIC).

MATERIAL AND METHODS

The study was comprised of 28 adult pigs (8 females and 20 males) of the Polish Large White breed. A one-chamber pacemaker was implanted in each of the 28 pigs. Electrocardiographic, echocardiographic and electrophysiological studies were carried out prior to the pacemaker implantation and at subsequent 4-week intervals. All electrocardiographic, echocardiographic and short electrophysiological study measurements in all swine were done under general anesthesia (propofol) after premedication with midazolam, medetomidine, and ketamine.

RESULTS

No significant changes in the duration of QT interval and corrected QT interval (QTc) were observed during consecutive weeks of the experiment. The duration of the QTc interval of female pigs was shown to be significantly longer than that of the males throughout the whole study period. Beginning from the 12th week of rapid ventricular pacing, a significant increase in duration of VERP was observed in both male and female pigs. Males and females did not differ significantly in terms of VERP duration determined throughout the whole study period. Ventricular pacing, stimulation with 2 and 3 premature impulses at progressively shorter coupling intervals and an imposed rhythm of 130 bpm or 150 bpm induced transient ventricular tachycardia in one female pig and four male pigs. One episode of permanent ventricular tachycardia was observed.

CONCLUSIONS

The number of induced arrhythmias increased proportionally to the severity of heart failure and duration of the experiment. However, relatively aggressive protocols of stimulation were required in order to induce arrhythmia in the studied pigs.

Sex differences in porcine left ventricular myocardial remodeling due to right ventricular pacing

Background

Although sex differences in heart failure (HF) prevalence and severity have been recognized, its molecular mechanisms are poorly understood. We used a tachycardia-induced cardiomyopathy model to determine the sex specific remodeling pattern in male and female adult pigs.

Methods

We compared the echocardiographic and molecular measures of myocardial remodeling in 19 male and 12 female pigs with chronic symptomatic systolic HF due to right ventricle (RV) pacing (170 bpm) and 6 male and 5 female sham-operated controls. Males achieved subsequent HF stages earlier than females.

Results

The progression of symptomatic HF was associated with the reduction of the left ventricle (LV) ejection fraction in both sexes (all p < 0.05). A significant LV dilatation occurred only in males (p < 0.001). The HF development was accompanied by an increased pro-hypertrophic factor GATA4 and TGF-β1 messenger RNA (mRNA) expression in the LV only in male pigs (all p < 0.01). The total gelatinolytic activity in LV was higher in males than females (irrespective of HF, p < 0.05), and the HF progression was associated with a reduced total gelatinolytic activity (p < 0.05) in the LV only in males. No differences in LV myocardial collagen content were found between HF groups and sexes. Cardiomyocyte cross-sectional diameter was significantly smaller in male hearts as compared to female (p < 0.05).

Conclusions

Male and female porcine hearts respond differently to RV pacing. Males, most likely due to a higher extracellular matrix turnover, demonstrated a significant LV dilatation, followed by a strong induction of pro-hypertrophic program, and an earlier development of symptomatic HF.

Electronic supplementary material

The online version of this article (doi:10.1186/s13293-015-0048-4) contains supplementary material, which is available to authorized users.

The use of a plastic guide improves the safety and reduces the duration of endotracheal intubation in the pig

The successful endotracheal intubation of pigs using the standard orotracheal method is challenging and technically difficult, because of the pig's oral anatomy and the presence of excess tissue in the oropharyngeal region. Hence, the operator, who is usually an anesthetist, requires extensive training in order to successfully perform the procedure in pigs. In this report, we describe a safe and quick method of successful endotracheal intubation in the pig using an 80-cm blunt-tipped plastic vascular catheter, when the pig is placed in ventral recumbency. Specifically, the use of this plastic guide wire shortened the duration of the procedure and reduced the risks of the procedure. Since the use of the guide wire also improves the ease of the procedure, its use will also enable inexperienced operators to perform successful first-time endotracheal intubation of pigs without causing injury.