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Verhaar N, Grages AM, Bienert-Zeit A, Schwieder A, Reineking W, Hewicker-Trautwein M, Kästner S, Geburek F. Flowmetry and spectrophotometry for the assessment of intestinal viability in horses with naturally occurring strangulating small intestinal lesions. Equine Vet J 2024; 56:1138-1148. [PMID: 38888520 DOI: 10.1111/evj.14118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Accepted: 05/16/2024] [Indexed: 06/20/2024]
Abstract
BACKGROUND Ancillary diagnostic methods to enhance the accuracy of viability assessment have not been established for use in clinical practice. OBJECTIVES To assess intestinal microperfusion measured by Laser Doppler Flowmetry and Spectrophotometry (LDFS) in naturally occurring small intestinal strangulations of different origins and to compare this between viable and non-viable segments. STUDY DESIGN Prospective clinical trial. METHODS Forty horses undergoing colic surgery for naturally occurring small intestinal strangulations were included. Tissue oxygen saturation (tSO2), haemoglobin (tHB) and blood flow (tBF) were determined by LDFS before and after release of the strangulation. Intestinal biopsies were taken in cases that underwent intestinal resection or intraoperative euthanasia and assessed using a semi-quantitative mucosal injury score (MIS). The LDFS measurements were compared between the different categories of strangulation causes and histopathological injury using parametric and non-parametric tests (p < 0.05). RESULTS Strangulations by pedunculated lipomas had lower tBF (13.9 ± 18 arbitrary units [AU]) than epiploic foramen entrapments (65.2 ± 61 AU; CI -1.697 to -0.2498; p = 0.005). Segments with MIS > 5 showed lower tBF during strangulation than segments with MIS < 4 (mean difference 61.1 AU; CI -1.119 to -0.07361; p = 0.03). This did not differ significantly following release of strangulation. Furthermore, there was a positive correlation between the inflammatory cell count and tBF during strangulation (r 0.34; CI 0.01 to 0.60; p = 0.04). The tSO2 and tHB did not differ between the different categories of lesions or injury. MAIN LIMITATIONS No biopsies could be taken from the intestinal segments that did not undergo resection. The duration of strangulation could not reliably be ascertained. CONCLUSIONS Blood flow measurements in naturally occurring strangulating lesions show a varying degree of ischaemia in different causes of strangulation. Intestinal blood flow measurements prior to release of the strangulation could potentially contribute to the identification of mucosal injury, yet a high individual variability and other contributing factors need to be considered.
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Affiliation(s)
- Nicole Verhaar
- Clinic for Horses, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Anna Marei Grages
- Clinic for Horses, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Astrid Bienert-Zeit
- Clinic for Horses, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Alexander Schwieder
- Clinic for Horses, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Wencke Reineking
- Department of Pathology, University of Veterinary Medicine Hannover, Hannover, Germany
| | | | - Sabine Kästner
- Clinic for Horses, University of Veterinary Medicine Hannover, Hannover, Germany
- Clinic for Small Animals, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Florian Geburek
- Clinic for Horses, University of Veterinary Medicine Hannover, Hannover, Germany
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Guo Q, Wang J, Ni C, Pan J, Zou J, Shi Y, Sun J, Zhang X, Wang D, Luan F. Research progress on the natural products in the intervention of myocardial infarction. Front Pharmacol 2024; 15:1445349. [PMID: 39239656 PMCID: PMC11374734 DOI: 10.3389/fphar.2024.1445349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2024] [Accepted: 08/05/2024] [Indexed: 09/07/2024] Open
Abstract
Coronary heart disease is a prevalent cardiovascular ailment globally, with myocardial infarction (MI) being one of its most severe manifestations. The morbidity and mortality of MI are escalating, showing an increasing trend among younger, highly educated individuals, thereby posing a serious threat to public health. Currently, thrombolysis, percutaneous coronary intervention, and coronary artery bypass grafting are the primary clinical treatments for MI. Although these methods significantly reduce patient mortality, complications often result in poor prognoses. Due to limitations in chemical synthetic drug research, the focus has shifted towards developing herbs based on natural substances. Natural medicines represent a novel approach for safer and more effective MI management and treatment. They can control multiple pathogenic variables by targeting various pathways and systems. This paper investigates the molecular mechanisms of MI and evaluates the application of natural products and medicinal plants in MI treatment over the past 5 years, demonstrating their specific good therapeutic potential and superior tolerance. These natural therapies have been shown to mitigate myocardial cell damage caused by MI through mechanisms such as oxidative stress, inflammation, apoptosis, angiogenesis, myocardial fibrosis, autophagy, endoplasmic reticulum stress, mitophagy, and pyroptosis. This review offers the latest insights into the application of natural products and medicinal plants in MI treatment, elucidating their mechanisms of action and serving as an important reference for MI prevention.
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Affiliation(s)
- Qiuting Guo
- College of Pharmacy, Xianyang Polytechnic Institute, Xianyang, China
| | - Jinhui Wang
- Shaanxi Key Laboratory of Chinese Medicine Fundamentals and New Drugs Research, School of Pharmacy, Shaanxi University of Chinese Medicine, Xi'an, Shaanxi, China
| | - Caixia Ni
- Key Laboratory of Medicinal and Edible Plants Resources Development of Sichuan Education Department, Sichuan Industrial Institute of Antibiotics, School of Pharmacy, Chengdu University, Chengdu, Sichuan, China
| | - Jiaojiao Pan
- Shaanxi Key Laboratory of Chinese Medicine Fundamentals and New Drugs Research, School of Pharmacy, Shaanxi University of Chinese Medicine, Xi'an, Shaanxi, China
| | - Junbo Zou
- Shaanxi Key Laboratory of Chinese Medicine Fundamentals and New Drugs Research, School of Pharmacy, Shaanxi University of Chinese Medicine, Xi'an, Shaanxi, China
| | - Yajun Shi
- Shaanxi Key Laboratory of Chinese Medicine Fundamentals and New Drugs Research, School of Pharmacy, Shaanxi University of Chinese Medicine, Xi'an, Shaanxi, China
| | - Jing Sun
- Shaanxi Key Laboratory of Chinese Medicine Fundamentals and New Drugs Research, School of Pharmacy, Shaanxi University of Chinese Medicine, Xi'an, Shaanxi, China
| | - Xiaofei Zhang
- Shaanxi Key Laboratory of Chinese Medicine Fundamentals and New Drugs Research, School of Pharmacy, Shaanxi University of Chinese Medicine, Xi'an, Shaanxi, China
| | - Deng Wang
- Department of Pharmacy, Xi'an No. 3 Hospital, The Affiliated Hospital of Northwest University, Xi'an, Shaanxi, China
| | - Fei Luan
- Shaanxi Key Laboratory of Chinese Medicine Fundamentals and New Drugs Research, School of Pharmacy, Shaanxi University of Chinese Medicine, Xi'an, Shaanxi, China
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Verhaar N, de Buhr N, von Köckritz-Blickwede M, Dümmer K, Hewicker-Trautwein M, Pfarrer C, Dengler F, Kästner S. Hypoxia signaling in the equine small intestine: Expression and distribution of hypoxia inducible factors during experimental ischemia. Front Vet Sci 2023; 10:1110019. [PMID: 36908508 PMCID: PMC9998946 DOI: 10.3389/fvets.2023.1110019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Accepted: 02/08/2023] [Indexed: 03/14/2023] Open
Abstract
Introduction Hypoxia inducible factors (HIF) are widely researched in human medicine for their role in different disease processes. The aim of this study was to investigate the expression and distribution of HIF in experimental small intestinal ischemia in the horse. Methods In 14 horses under general anesthesia, segmental jejunal ischemia with 90% reduction in blood flow was induced. The horses were randomly divided into two groups of seven horses, one subjected to ischemic postconditioning (IPoC) by delayed reperfusion, and a control group (group C) undergoing undelayed reperfusion. Intestinal samples were taken pre-ischemia, after ischemia and after reperfusion. Following immunohistochemical staining for HIF1α and -2α, the immunoreactivity pattern in the small intestine was evaluated by light microscopy, and the mucosal enterocyte and muscularis staining were semi-quantitatively scored. Additionally, mucosal HIF1α protein levels were determined by an Enzyme Linked Immunosorbent Assay (ELISA), and mRNA levels of HIF1α and its target genes by a two-step real-time Reverse Transcriptase Polymerase Chain Reaction. Statistical comparison was performed between the groups and time points using parametric and non-parametric tests (p < 0.05). Results All cell types exhibited cytoplasmic and nuclear immunoreactivity for HIF1α. After reperfusion, the cytoplasmic staining of the crypt and villus enterocytes as well as the villus nuclear staining significantly increased, whereas the perinuclear granules in the crypts decreased. The protein levels showed a significant decrease in group C at reperfusion, with lower HIF1α levels in group C compared to group IPoC during ischemia and reperfusion. No other group differences could be detected. In the HIF2α stained slides, mild to moderate cytoplasmic staining yet no nuclear immunoreactivity of the enterocytes was observed, and no significant changes over time were noted. Discussion the changes in HIF1α immunoreactivity pattern and expression over time suggest that this transcription factor plays a role in the intestinal response to ischemia in horses. However, the current study could not identify an effect of IPoC on HIF distribution or expression.
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Affiliation(s)
- Nicole Verhaar
- Clinic for Horses, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Nicole de Buhr
- Department of Biochemistry, University of Veterinary Medicine Hannover, Hannover, Germany.,Research Center for Emerging Infections and Zoonoses, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Maren von Köckritz-Blickwede
- Department of Biochemistry, University of Veterinary Medicine Hannover, Hannover, Germany.,Research Center for Emerging Infections and Zoonoses, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Katrin Dümmer
- Department of Biochemistry, University of Veterinary Medicine Hannover, Hannover, Germany.,Research Center for Emerging Infections and Zoonoses, University of Veterinary Medicine Hannover, Hannover, Germany
| | | | - Christiane Pfarrer
- Institute for Anatomy, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Franziska Dengler
- Institute of Physiology, Pathophysiology and Biophysics, Department of Biomedical Sciences, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Sabine Kästner
- Clinic for Horses, University of Veterinary Medicine Hannover, Hannover, Germany.,Small Animal Clinic, University of Veterinary Medicine Hannover, Hannover, Germany
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Dengler F, Sternberg F, Grages M, Kästner SBR, Verhaar N. Adaptive mechanisms in no flow vs. low flow ischemia in equine jejunum epithelium: Different paths to the same destination. Front Vet Sci 2022; 9:947482. [PMID: 36157182 PMCID: PMC9493374 DOI: 10.3389/fvets.2022.947482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Accepted: 08/17/2022] [Indexed: 01/18/2023] Open
Abstract
Intestinal ischemia reperfusion injury (IRI) is a frequent complication of equine colic. Several mechanisms may be involved in adaptation of the intestinal epithelium to IRI and might infer therapeutic potential, including hypoxia-inducible factor (HIF) 1α, AMP-activated protein kinase (AMPK), nuclear factor-erythroid 2-related factor 2 (NRF2), and induction of autophagy. However, the mechanisms supporting adaptation and thus cellular survival are not completely understood yet. We investigated the activation of specific adaptation mechanisms in both no and low flow ischemia and reperfusion simulated in equine jejunum epithelium in vivo. We found an activation of HIF1α in no and low flow ischemia as indicated by increased levels of HIF1α target genes and phosphorylation of AMPKα tended to increase during ischemia. Furthermore, the protein expression of the autophagy marker LC3B in combination with decreased expression of nuclear-encoded mitochondrial genes indicates an increased rate of mitophagy in equine intestinal IRI, possibly preventing damage by mitochondria-derived reactive oxygen species (ROS). Interestingly, ROS levels were increased only shortly after the onset of low flow ischemia, which may be explained by an increased antioxidative defense, although NFR2 was not activated in this setup. In conclusion, we could demonstrate that a variety of adaptation mechanisms manipulating different aspects of cellular homeostasis are activated in IRI irrespective of the ischemia model, and that mitophagy might be an important factor for epithelial survival following small intestinal ischemia in horses that should be investigated further.
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Affiliation(s)
- Franziska Dengler
- Department of Biochemical Sciences, Institute of Physiology, Pathophysiology and Biophysics, University of Veterinary Medicine, Vienna, Austria
- *Correspondence: Franziska Dengler
| | - Felix Sternberg
- Department of Biochemical Sciences, Institute of Physiology, Pathophysiology and Biophysics, University of Veterinary Medicine, Vienna, Austria
| | - Marei Grages
- Clinic for Horses, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Sabine BR Kästner
- Clinic for Horses, University of Veterinary Medicine Hannover, Hannover, Germany
- Small Animal Clinic, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Nicole Verhaar
- Clinic for Horses, University of Veterinary Medicine Hannover, Hannover, Germany
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Low Flow versus No Flow: Ischaemia Reperfusion Injury Following Different Experimental Models in the Equine Small Intestine. Animals (Basel) 2022; 12:ani12162158. [PMID: 36009747 PMCID: PMC9405230 DOI: 10.3390/ani12162158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2022] [Revised: 08/17/2022] [Accepted: 08/19/2022] [Indexed: 11/17/2022] Open
Abstract
Simple Summary One of the main causes of colic in horses is the occlusion of the intestinal blood vessels after displacement or entrapment of the small intestine. In search of new therapies to treat this lethal disease, experimental models have been used to simulate the clinical situation. Both low flow (LF) models with partial blood flow occlusion as well as no flow (NF) models with complete occlusion have been implemented in different studies. This has led to conflicting results and comparative studies are lacking. The objective of this study was to characterize the development of intestinal injury over time in two different experimental models implementing either partial or complete vessel occlusion. Under general anaesthesia, local intestinal blood flow was reduced by 80% in seven horses (LF), and by 100% in another seven horses (NF). The LF group exhibited more bleeding in the intestinal wall and a relatively high variability in intestinal oxygen levels and tissue damage. The NF group showed lower oxygen levels and decreased barrier function of the intestinal wall. These results aid in the selection of the suitable experimental model for future studies. The high variability following LF suggests that an NF model may produce more consistent intestinal damage. Abstract In experimental studies investigating strangulating intestinal lesions in horses, different ischaemia models have been used with diverging results. Therefore, the aim was to comparatively describe ischaemia reperfusion injury (IRI) in a low flow (LF) and no flow (NF) model. Under general anaesthesia, 120 min of jejunal ischaemia followed by 120 min of reperfusion was induced in 14 warmbloods. During ischaemia, blood flow was reduced by 80% (LF, n = 7) or by 100% (NF, n = 7). Intestinal blood flow and oxygen saturation were measured by Laser Doppler fluxmetry and spectrophotometry. Clinical, histological, immunohistochemical and Ussing chamber analyses were performed on intestinal samples collected hourly. Tissue oxygen saturation was significantly lower in NF ischaemia. The LF group exhibited high variability in oxygen saturation and mucosal damage. Histologically, more haemorrhage was found in the LF group at all time points. Cleaved-caspase-3 and calprotectin-stained cells increased during reperfusion in both groups. After NF ischaemia, the tissue conductance was significantly higher during reperfusion. These results aid in the selection of suitable experimental models for future studies. Although the LF model has been suggested to be more representative for clinical strangulating small intestinal disease, the NF model produced more consistent IRI.
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Sengul I, Sengul D. Clinical Insights on Pre- and Novel Postconditioning in Equine Jejunal Ischemia. Med Arch 2021; 75:237-238. [PMID: 34483457 PMCID: PMC8385745 DOI: 10.5455/medarh.2021.75.237-238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2021] [Accepted: 06/30/2021] [Indexed: 11/25/2022] Open
Affiliation(s)
- Ilker Sengul
- Division of Endocrine Surgery, Giresun University Faculty of Medicine, Giresun, Turkey.,Department of General Surgery, Giresun University Faculty of Medicine, Giresun, Turkey
| | - Demet Sengul
- Department of Pathology, Giresun University, Faculty of Medicine, Giresun, Turkey
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Verhaar N, de Buhr N, von Köckritz-Blickwede M, Hewicker-Trautwein M, Pfarrer C, Mazzuoli-Weber G, Schulte H, Kästner S. Ischaemic postconditioning reduces apoptosis in experimental jejunal ischaemia in horses. BMC Vet Res 2021; 17:175. [PMID: 33902575 PMCID: PMC8077964 DOI: 10.1186/s12917-021-02877-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 04/12/2021] [Indexed: 03/06/2023] Open
Abstract
BACKGROUND Ischaemic postconditioning (IPoC) refers to brief periods of reocclusion of blood supply following an ischaemic event. This has been shown to ameliorate ischaemia reperfusion injury in different tissues, and it may represent a feasible therapeutic strategy for ischaemia reperfusion injury following strangulating small intestinal lesions in horses. The objective of this study was to assess the degree cell death, inflammation, oxidative stress, and heat shock response in an equine experimental jejunal ischaemia model with and without IPoC. METHODS In this randomized, controlled, experimental in vivo study, 14 horses were evenly assigned to a control group and a group subjected to IPoC. Under general anaesthesia, segmental ischaemia with arterial and venous occlusion was induced in 1.5 m jejunum. Following ischaemia, the mesenteric vessels were repeatedly re-occluded in group IPoC only. Full thickness intestinal samples and blood samples were taken at the end of the pre-ischaemia period, after ischaemia, and after 120 min of reperfusion. Immunohistochemical staining or enzymatic assays were performed to determine the selected variables. RESULTS The mucosal cleaved-caspase-3 and TUNEL cell counts were significantly increased after reperfusion in the control group only. The cleaved-caspase-3 cell count was significantly lower in group IPoC after reperfusion compared to the control group. After reperfusion, the tissue myeloperoxidase activity and the calprotectin positive cell counts in the mucosa were increased in both groups, and only group IPoC showed a significant increase in the serosa. Tissue malondialdehyde and superoxide dismutase as well as blood lactate levels showed significant progression during ischaemia or reperfusion. The nuclear immunoreactivity of Heat shock protein-70 increased significantly during reperfusion. None of these variables differed between the groups. The neuronal cell counts in the myenteric plexus ganglia were not affected by the ischaemia model. CONCLUSIONS A reduced apoptotic cell count was found in the group subjected to IPoC. None of the other tested variables were significantly affected by IPoC. Therefore, the clinical relevance and possible protective mechanism of IPoC in equine intestinal ischaemia remains unclear. Further research on the mechanism of action and its effect in clinical cases of strangulating colic is needed.
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Affiliation(s)
- Nicole Verhaar
- Clinic for Horses, University of Veterinary Medicine Hannover, Hannover, Germany.
| | - Nicole de Buhr
- Department of Biochemistry, University of Veterinary Medicine Hannover, Hannover, Germany
- Research Center for Emerging Infections and Zoonoses, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Maren von Köckritz-Blickwede
- Department of Biochemistry, University of Veterinary Medicine Hannover, Hannover, Germany
- Research Center for Emerging Infections and Zoonoses, University of Veterinary Medicine Hannover, Hannover, Germany
| | | | - Christiane Pfarrer
- Institute for Anatomy, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Gemma Mazzuoli-Weber
- Institute for Physiology and Cell Biology, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Henri Schulte
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
| | - Sabine Kästner
- Clinic for Horses, University of Veterinary Medicine Hannover, Hannover, Germany
- Small Animal Clinic, University of Veterinary Medicine Hannover, Hannover, Germany
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