Myoglobin Release Research Articles

Experimental and Numerical Integrated Strategy for the Optimization of Microfluidic Parameters for Eudragit L100 Nanoparticles and Microparticles.

Oral immunization offers a minimally invasive administration, inducing local and systemic immune responses and facilitating mass immunization without needle-related risks. However, the gastrointestinal environment poses challenges, compromising vaccine effectiveness through enzymatic degradation and poor absorption by Peyer's patches. Advances in nanoparticle and microparticle (NP/MP) technology protect vaccines from degradation and enhance targeted release. The aim of this study was to develop pH-controlled polymeric carriers for the oral delivery of protein vaccines in order to target the antigen-presenting cells and M cells in the region of Peyer's patches. Here, myoglobin was chosen as a model protein vaccine. This study focuses on Eudragit L100, a pH-responsive polymer stable in acidic conditions and dissolving at higher pH, to develop carriers for controlled myoglobin release in the intestinal tract. A microfluidic-based manufacturing process for Eudragit L100 NPs and MPs is optimized using a comprehensive experimental and computational approach to obtain NPs and MPs through the same setup. Integrating in silico and experimental methods highlights the potential of numerical simulations to streamline final product development. This approach improves the efficiency and cost-effectiveness of NP/MP production, demonstrating how the combination of design of experiment and numerical simulations can optimize production parameters and refine manufacturing processes for advanced drug delivery systems.

Hemoadsorption therapy for myoglobin removal in rhabdomyolysis: consensus of the hemoadsorption in rhabdomyolysis task force

BackgroundRhabdomyolysis describes a syndrome characterized by muscle necrosis and the subsequent release of creatine kinase and myoglobin into the circulation. Myoglobin elimination with extracorporeal hemoadsorption has been shown to effectively remove myoglobin from the circulation. Our aim was to provide best practice consensus statements developed by the Hemoadsorption in Rhabdomyolysis Task Force (HRTF) regarding the use of hemadsorption for myoglobin elimination.MethodsA systematic literature search was performed until 11th of January 2023, after which the Rhabdomyolysis RTF was assembled comprising international experts from 6 European countries. Online conferences were held between 18th April − 4th September 2023, during which 37 consensus questions were formulated and using the Delphi process, HRTF members voted online on an anonymised platform. In cases of 75 to 90% agreement a second round of voting was performed.ResultsUsing the Delphi process on the 37 questions, strong consensus (> 90% agreement) was achieved in 12, consensus (75 to 90% agreement) in 10, majority (50 to 74%) agreement in 13 and no consensus (< 50% agreement) in 2 cases. The HRTF formulated the following recommendations: (1) Myoglobin contributes to the development of acute kidney injury; (2) Patients with myoglobin levels of > 10,000 ng/ml should be considered for extracorporeal myoglobin removal by hemoadsorption; (3) Hemoadsorption should ideally be started within 24 h of admission; (4) If myoglobin cannot be measured then hemoadsorption may be indicated based on clinical picture and creatinine kinase levels; (5) Cartridges should be replaced every 8–12 h until myoglobin levels < 10,000 ng/ml; (6) In patients with acute kidney injury, hemoadsorption can be discontinued before dialysis is terminated and should be maintained until the myoglobin concentration values are consistently < 5000 ng/ml.ConclusionsThe current consensus of the HRTF support that adjuvant hemoadsorption therapy in severe rhabdomyolysis is both feasible and safe and may be an effective method to reduce elevated circulating levels of myoglobin.

Forensic characteristics of injuries from thermo-baric explosive device

Since the beginning of the Russian Federation's invasion of Ukraine in 2022, explosive trauma has become an extremely urgent problem, as the main source of bodily injury among both the military in the combat zone and the civilian population in cities has been the impact of explosive devices. The aim of the study is the examination of the forensic characteristics of damage to biological objects that were formed from thermal exposure and shock wave as a result of the explosion of a cumulative munition and in the conditions of an experimental explosion model. The objects of the study were the materials of two examinations on the death of Ukrainian soldiers who died in the war zone (archival "Conclusions of the medical examination" of the Kyiv City Clinical Bureau of Forensic Medical Examination in 2023). Under the conditions of the experiment, studies of pathomorphological changes in the liver and small intestine of 30 white outbred rats from the action of an artificially created air shock wave with an overpressure of 31.62±4.84 kPa were carried out. The injuries were examined macroscopically and using standard laboratory histological techniques. Microscopy of histological sections was performed using an Axio Imager 2 microscope (Zeiss, Germany) at magnifications of ×200 and ×400. Statistical processing of the obtained quantitative results was carried out using the STATISTICA 6.1 software product. Under the condition of the explosion of the ammunition with the cumulative effect of the rocket-propelled infantry flamethrower "Bumblebee" on sectional incisions of the skin and muscles of the thigh in the projection of areas of redness, a picture of a gelatinous consistency of bright red color was macroscopically determined due to abundant blood impregnation of muscles and subcutaneous fat and partial loss of muscle structure with the release of myoglobin. The bright red color of the skin of the thigh and pelvis without burning the hair may indicate the superficial thermal effect of the explosive device and the protection of the skin by clothing. Diffusely located numerous both paired and single abrasions and shallow wounds, small rounded, oblong, circular in shape, which are the result of fragments of a rocket-propelled grenade equipped with a fire mixture, were also determined. The effect of an air shock wave with an overpressure of 31.62±4.84 kPa on the liver parenchyma of rats was determined by focal hemorrhages with rupture of the terminal central vein of the hepatic lobule, edema of the parasinusoidal spaces, and sludges in the sinusoids. In the wall of the small intestine, acute hemodynamic disorders occurred in the form of vasodilation of arterial vessels, venular and capillary stasis. There was layering and swelling of the small intestine wall, rupture of veins, focal hemorrhage. Thus, the revealed characteristic pathomorphological signs of the destructive effect of overpressure as a result of a blast wave (barotrauma) are typical and common both in the areas of the human thigh and pelvis, and in biological objects of experimental animals. The obtained results are consistent with the pathomorphological manifestations of barotrauma in areas of the human body as a result of the action of an explosive device with a cumulative effect.

Boron nitride nanotube-based creatinine biosensors for athlete physical condition monitoring

Monitoring creatinine levels is critical for evaluating renal function and muscular health in athletes. Creatinine is a waste product of creatine metabolism in skeletal muscle, and is filtered by the kidneys at a relatively constant rate. Elevated serum creatinine can indicate impaired kidney function, rhabdomyolysis, or skeletal muscle trauma. In athletes, creatinine levels increase after intense exertion due to muscle breakdown and myoglobin release. Abnormal creatinine signifies poor training adaptation, overtraining, or trauma. Therefore, close monitoring of creatinine in athletes provides insight into their physical condition. Current laboratory methods for measuring creatinine like Jaffe reaction and high-performance liquid chromatography are accurate but time-consuming, requiring blood sampling. Biosensors offer rapid, painless creatinine detection from small volumes, but current versions suffer from instability, use of mediators, and lack portability. Boron nitride nanotubes (BNNTs) are promising materials for electrochemical biosensing due to their structure, surface chemistry, and biocompatibility. Here, we report BNNT-based electrochemical biosensors for detecting creatinine in blood samples from athletes. BNNTs synthesized by induction thermal plasma technique were used to immobilize creatinine metabolizing enzymes. Creatinine levels were measured by chronoamperometry and compared to isotope dilution mass spectrometry. We demonstrate high sensitivity and selectivity of the BNNT biosensor with facile fabrication method and portable platform, promising for rapid creatinine monitoring in athletes. This can provide insight into muscular damage and renal function during training and competition.

Stress biomarker changes following a series of repeated static and dynamic apneas in non-divers

PurposeThis study examined the magnitude of physiological strain imposed by repeated maximal static and dynamic apneas through assessing a panel of stress-related biomarkers. MethodsEleven healthy men performed on three separate occasions (≥72-h apart): a series of five repeated maximal (i) static (STA) or (ii) dynamic apneas (DYN) or (iii) a static eupneic protocol (CTL). Venous blood samples were drawn at 30, 90, and 180-min after each protocol to determine ischaemia modified albumin (IMA), neuron-specific enolase (NSE), myoglobin, and high sensitivity cardiac troponin T (hscTnT) concentrations. ResultsIMA was elevated after the apnoeic interventions (STA,+86%;DYN,+332%,p ≤ 0.047) but not CTL (p = 0.385). Myoglobin was higher than baseline (23.6 ± 3.9 ng/mL) 30-min post DYN (+70%,38.8 ± 13.3 ng/mL,p = 0.030). A greater myoglobin release was recorded in DYN compared with STA and CTL (p ≤ 0.035). No changes were observed in NSE (p = 0.207) or hscTnT (p = 0.274). ConclusionsFive repeated maximal DYN led to a greater muscle injury compared with STA but neither elicited myocardial injury or neuronal-parenchymal damage.

Renoprotective effect of thymoquinone against rhabdomyolysis-induced acute kidney injury in the rat model.

Rhabdomyolysis leads to the release of myoglobin, sarcoplasmic proteins, and electrolytes into the blood circulation causing acute kidney injury (AKI). Thymoquinone, a natural compound found in Nigella sativa seeds, has antioxidant and anti-inflammatory effects. This investigation assessed the renoprotective effect of thymoquinone on rhabdomyolysis-induced AKI in rats. Male Wistar rats were categorized into six groups (n = 6): 1. Control: (normal saline), 2. Glycerol (50 ml/kg, single dose, IM), 3-5: Glycerol + thymoquinone (1, 2.5 and 5 mg/kg, 4 days, IP), 6. Thymoquinone (5 mg/kg). On day 5, serum and kidney tissue were isolated and the amounts of serum creatinine and blood urea nitrogen (BUN), renal malondialdehyde (MDA), glutathione (GSH.), tumor necrosis factor-alpha (TNF-α), neutrophil gelatinase-associated lipocalin (NGAL), and pathological changes were evaluated. Glycerol increased creatinine, BUN, MDA, TNF-α, and NGAL levels. It decreased GSH amounts and caused renal tubular necrosis, glomerular atrophy, and myoglobin cast in kidney tissue. Co-administration of glycerol and thymoquinone reduced creatinine, BUN, histopathological alterations, and MDA levels, and enhanced GSH amounts. Administration of glycerol and thymoquinone (5 mg/kg) had no significant effect on TNF-α amount but decreased NGAL protein levels. The administration of thymoquinone (5 mg/kg) alone did not display a significant difference from the control group. Rhabdomyolysis from glycerol injection in rats can cause kidney damage. Thymoquinone may attenuate renal dysfunction and oxidative stress. However, the TNF-α level was not significantly affected. Further studies are needed to explore the potential therapeutic effects of thymoquinone in managing AKI.

Myoglobin Cast Nephropathy, A Series of Five Cases

Acute kidney injury is a potential complication of severe rhabdomyolysis, which occur mostly due to excessive release of myoglobin from necrosed muscle cells. The major causes of rhabdomyolysis in Indian subcontinent include wasp sting, snake envenomation, strenuous exercise and seizures, etc. The main pathophysiology of AKI due to tubular obstruction, renal vasoconstriction and tubular damage due to myoglobin casts in the tubular lumen. With raised serum creatinine level these patients also show remarkably high serum creatine phosphokinase (CPK). On light microscopy myoglobin casts present as granular eosinophilic pigment casts, sometimes may mimic haemoglobin casts or bile casts. To differentiate the myoglobin casts from other, immunohistochemistry for myoglobin is used in most of the centers worldwide now days. A good number of patients need haemodialysis and most of them recover well, however early diagnosis and timely intervention is warranted. Here we report five cases of myoglobin cast nephropathy in a year at department of histopathology, Armed Forces Institute of Pathology (AFIP), Dhaka, following different non traumatic causes, diagnosed by immunohistochemistry for myoglobin.

Post-injury Inhibition of Endothelin-1 Dependent Renal Vasoregulation Mitigates Rhabdomyolysis-Induced Acute Kidney Injury.

In patients with rhabdomyolysis, the overwhelming release of myoglobin into the circulation is the primary cause of kidney injury. Myoglobin causes direct kidney injury as well as severe renal vasoconstriction. An increase in renal vascular resistance (RVR) results in renal blood flow (RBF) and glomerular filtration rate (GFR) reduction, tubular injury, and acute kidney injury (AKI). The mechanisms that underlie rhabdomyolysis-induced AKI are not fully understood but may involve the local production of vasoactive mediators in the kidney. Studies have shown that myoglobin stimulates endothelin-1 (ET-1) production in glomerular mesangial cells. Circulating ET-1 is also increased in rats subjected to glycerol-induced rhabdomyolysis. However, the upstream mechanisms of ET-1 production and downstream effectors of ET-1 actions in rhabdomyolysis-induced AKI remain unclear. Vasoactive ET-1 is generated by ET converting enzyme 1 (ECE-1)-induced proteolytic processing of inactive big ET to biologically active peptides. The downstream ion channel effectors of ET-1-induced vasoregulation include the transient receptor potential cation channel, subfamily C member 3 (TRPC3). This study demonstrates that glycerol-induced rhabdomyolysis in Wistar rats promotes ECE-1-dependent ET-1 production, RVR increase, GFR decrease, and AKI. Rhabdomyolysis-induced increases in RVR and AKI in the rats were attenuated by post-injury pharmacological inhibition of ECE-1, ET receptors, and TRPC3 channels. CRISPR/Cas9-mediated knockout of TRPC3 channels attenuated ET-1-induced renal vascular reactivity and rhabdomyolysis-induced AKI. These findings suggest that ECE-1-driven ET-1 production and downstream activation of TRPC3-dependent renal vasoconstriction contribute to rhabdomyolysis-induced AKI. Hence, post-injury inhibition of ET-1-mediated renal vasoregulation may provide therapeutic targets for rhabdomyolysis-induced AKI.

A randomized placebo-controlled trial of nicotinamide riboside and pterostilbene supplementation in experimental muscle injury in elderly individuals.

BACKGROUNDDuring aging, there is a functional decline in the pool of muscle stem cells (MuSCs) that influences the functional and regenerative capacity of skeletal muscle. Preclinical evidence has suggested that nicotinamide riboside (NR) and pterostilbene (PT) can improve muscle regeneration, e.g., by increasing MuSC function. The objective of this study was to investigate if supplementation with NR and PT (NRPT) promotes skeletal muscle regeneration after muscle injury in elderly individuals by improved recruitment of MuSCs.METHODSThirty-two elderly individuals (55-80 years of age) were randomized to daily supplementation with either NRPT (1,000 mg NR and 200 mg PT) or matched placebo. Two weeks after initiation of supplementation, skeletal muscle injury was induced by electrically induced eccentric muscle work. Skeletal muscle biopsies were obtained before, 2 hours after, and 2, 8, and 30 days after injury.RESULTSA substantial skeletal muscle injury was induced by the protocol and associated with release of myoglobin and creatine kinase, muscle soreness, tissue edema, and a decrease in muscle strength. MuSC content, proliferation, and cell size revealed a large demand for recruitment after injury, but this was not affected by NRPT. Furthermore, histological analyses of muscle fiber area, central nuclei, and embryonic myosin heavy chain showed no NRPT supplementation effect.CONCLUSIONDaily supplementation with 1,000 mg NR and 200 mg PT is safe but does not improve recruitment of the MuSC pool or other measures of muscle recovery in response to injury or subsequent regeneration in elderly individuals.TRIAL REGISTRATIONClinicalTrials.gov NCT03754842.FUNDINGNovo Nordisk Foundation (NNF17OC0027242) and Novo Nordisk Foundation CBMR.

Ramipril mitigates Glycerol‐induced Acute Kidney Injury in Rats via its Anti‐oxidant, Anti‐renin and Anti‐apoptosis Effects

A sudden decrease in the functionality of the kidney with concomitant structural damage and functional loss is known as acute kidney injury (AKI), with some of the potential causes having to do with a focal mismatch between oxygen and nutrient delivery to the nephrons. Increased energy demands on account of cellular stress is another cause [Kellum et al 2021]. AKI occurs when renal function is acutely decreased, so waste products accumulate within the body, making the body unable to maintain electrolyte, acid‐base, and water balance [Bhatraju et al 2020]. As a result of the decrease in the kidney’s ability to carry out its perfusion activity, the epithelial cells lost the ability to maintain sufficient intracellular ATP for essential processes. This ATP depletion leads to cell injury. Depending on the severity of ATP depletion, cell death by necrosis or apoptosis could occur [Biswas et al 2018]. Studies have actually demonstrated that the pathogenesis of glycerol‐induced AKI involves myoglobin toxicity, reactive oxygen species, inflammation, and redox‐active iron [Al Asmari et al 2017; Wu et al 2017]. Currently, animal models of glycerol‐induced AKI are widely used [Mousleh et al 2018]. Glycerol injection into the muscle causes the release of myoglobin and other muscle contents into the circulation, ultimately resulting in AKI.Twenty animals divided into four groups of five animals per group were used. Group I served as control while group II received glycerol on day 8 only. Groups III and IV were administered with pioglitazone and ramipril for 7 days respectively and on day 8 received glycerol. On day 9 blood samples were collected for serum biochemical analysis of markers of oxidative stress, enzymatic and non‐enzymatic antioxidants, creatinine and blood urea nitrogen. Animals were sacrificed thereafter; and kidney tissues were harvested for histopathology and immunohistochemistry. Expression of caspase 3, renin receptor, NF‐κB, and KIM‐1 were carried out.Results from this study showed that ramipril and pioglitazone significantly inhibited markers of oxidative stress while also significantly increased the levels of enzymatic and non‐enzymatic anti‐oxidant markers. These drugs caused decreased levels of creatinine and BUN. While massive leucocytes infiltration and congestion of the kidney occurred in the toxicant group, it was mild in the ramipril treated group and the two drugs significantly inhibited the expressions of the four proteins, which were highly expressed in the toxicant group.Thus ramipril and pioglitazone have nephroprotective effect and mitigated acute kidney injury through their anti‐inflammatory, anti‐apoptosis, anti‐renin and anti‐oxidant properties.Some ReferencesAl Asmari AK, Al Sadoon KT, Obaid AA, Yesunayagam D, Tariq M. Protective effect of quinacrine against glycerol‐induced acute kidney injury in rats. BMC Nephrol. 2017; 18:41.Kellum JA, Romagnani P, Ashuntantang G, Ronco C, Zarbock A, Hans‐ Joachim A. Acute kidney injury. Disease Primers 2021; 7: 52

Myoglobin knockout mice experience less damage and more immune infiltration in muscle pressure injury

IntroductionMuscle pressure ulcers are slow to heal and classified as “chronic” wounds, but the reasons for slow healing are not well understood. Elevated levels of extracellular hemoglobin have been implicated in the pathogenesis and impaired healing of sickle cell and vascular ulcers. We question whether extracellular release of myoglobin after muscle pressure injury might contribute to a hostile wound environment, analogous to hemoglobin. We hypothesise that knockout of myoglobin will decrease tissue damage and improve the microenvironment of muscle pressure ulcers.MethodsWe developed germline Myoglobin knockout (Mb–/–) mice via CRISPR deletion. Similar to previous studies, our adult Mb–/– mice show no phenotypic differences to Mb‐wildtype (Mb+/+) mice. Pressure injuries were created in mice by applying a pair of 12 mm magnets to the dorsal skinfold and panniculus carnosus muscle, in two intervals of 12 hours. We compared pressure ulcers in elderly 20‐month‐old mice carrying Mb–/– or Mb+/+. Ex vivo wound tissues were analysed at day 3 after injury.ResultsMb‐wildtype mice had high levels of ferric iron in the wound localized to the extracellular space and infiltrating cells (presumably macrophages). In knockout mice, iron was undetectable. The knockout mice had smaller pressure ulcers post‐injury and 50% less tissue damage at the wound centre (p &lt; 0.01), compared to control Mb+/+ mice. In addition, the wounds of Mb–/– mice show a marked decrease in protein nitration (2.7‐fold decrease in nitrotyrosine levels; p &lt; 0.0001) compared to Mb+/+ mice. Furthermore, Mb‐knockout wounds exhibited an almost 21‐fold decrease in DNA oxidation, measured by oxidised guanine (8‐oxoguanine; p &lt; 0.0001) compared to Myoglobin+/+. We found 3.5‐fold greater infiltration of immune cells (p &lt; 0.01) and higher CCL7 chemokine expression (p &lt; 0.01) in Mb‐knockout tissues than Mb‐wildtype. Furthermore, Mb–/– wounds displayed a four‐fold decrease in citrullinated histone 3 (p &lt; 0.0001), a marker of extracellular traps, compared to Mb+/+.ConclusionIn the absence of myoglobin, pressure‐injured tissues displayed less oxidative and nitrosative damage. Interestingly, they also showed higher immune infiltration and decreased extracellular traps, meaning that increased immune infiltration co‐occurred with decreased oxidative stress. We conclude that extracellular myoglobin contributes to oxidative stress and immune dysfunction in muscle pressure ulcers, and its removal causes less tissue death. This has important implications for the use of iron chelation therapy in the treatment of muscle pressure ulcers.

Postinjury Inhibition of Endothelin‐1 Dependent Renal Vasoregulation Mitigates Rhabdomyolysis‐Induced Acute Kidney Injury

Rhabdomyolysis is a life‐threatening condition resulting from the breakdown of skeletal muscle fibers leading to the release of myoglobin into the blood. Increased circulating myoglobin can cause kidney damage, and acute kidney injury (AKI) occurs in 33‐50% of patients with myoglobinuria. Persistent constriction of the renal microvessels, which reduces renal blood flow (RBF) and glomerular filtration rate (GFR), contributes to rhabdomyolysis‐induced AKI. Since activation of G‐protein‐coupled receptors (GPCR) and ion channels regulate renal vascular resistance (RVR), rhabdomyolysis may likely modulate RVR via GPCR and vascular ion channel mechanisms. Pretreatment of rats with an endothelin receptor antagonist has been shown to alleviate rhabdomyolysis‐induced AKI. However, the downstream and upstream links between rhabdomyolysis and increased ET‐1 synthesis are unknown. The downstream effectors of ET‐1‐induced vasoconstriction are smooth muscle cell (SMC) Ca2+‐permeable ion channels. Yet, the ion channel mechanisms that trigger renal vasoconstriction in rhabdomyolysis‐induced AKI remain unknown. Also, most cases of rhabdomyolysis‐induced AKI cannot be predicted. Whether post‐injury inhibition of the vascular mechanisms of ET‐1 ameliorates, rhabdomyolysis‐induced AKI is unknown. This study investigates post‐injury renal production and vascular regulation of the ET system in rhabdomyolysis‐induced AKI. Six h of rhabdomyolysis increased peptidase endothelin converting enzyme (ECE‐1)‐dependent biosynthesis of ET‐1 in the kidneys. Rhabdomyolysis‐induced AKI was not sex‐dependent. At 24 h, rhabdomyolysis also increased renal reactive oxygen species (ROS), ECE‐1, and ET‐1 levels. Furthermore, ET‐1 activated rat renal vascular smooth muscle cell TRPC3 leading to a reduction in RBF and increased RVR. Protein expression levels of the ET receptors (ETA and ETB) and TRPC3 channels in renal microvessels were unaltered. However, postinjury inhibition of ECE1, ET Receptors, and TRPC3 mitigated rhabdomyolysis‐induced GFR impairment, renal hypoperfusion, AKI biomarker elevation, and morphological kidney damage. To further explore the role of TRPC3 ion channels in rhabdomyolysis‐induced AKI, we subjected TRPC3 knock‐out (KO) rats to rhabdomyolysis. Compared to their wild‐type counterparts, KO rats show protection against rhabdomyolysis‐induced AKI. Our findings suggest that ECE‐driven proteolytic ET‐1 production contributes to rhabdomyolysis‐induced AKI. Downstream, ET‐derived DAG activates renal vascular smooth muscle cell TRPC3 channels leading to extracellular calcium entry, vasoconstriction, increased RVR, and reduced GFR.

Clostridioides difficile Induced Rhabdomyolysis Associated With Decompensated Cirrhosis.

Rhabdomyolysis (RBD) occurs secondary to tissue injury, resulting in (muscle) cell lysis and release of intracellular electrolytes and proteins into circulation. An elevation in the muscle enzyme, creatine kinase (CK), is a diagnostic marker and indicates muscle breakdown. Symptoms include dark urine caused by release of myoglobin, myalgias, and acute kidney injury (AKI). RBD is categorized as (1) traumatic, (2) nontraumatic exertional (ie, metabolic myopathies), or (3) non-exertional and non-traumatic. Clostridioides difficile (CD) has been previously reported to cause RBD, but the risk factors, pathogenesis, and recommended treatment regimen remain unclear.

Spread of alimentary-toxic paroxysmal myoglobinuria-haff disease (literature review)

In 1924, Haff disease was first detected in East Prussia. Till now, cases of Haff disease have been recorded in Sweden, Russia, the United States, China, Brazil, Japan, and China among people and animals. During the last 40 years, there has been a significant expansion in the geographical range of Haff disease. From 1924 to 2019, 31 outbreaks were recorded in various parts of the world. The total number of victims was about 3,000 people. In Russia, the last cases of human disease were registered in 2019-2020. In fact, the source of the toxin is fish (crucian carp, carp, pike, burbot, walleye, perch, ruff, ide, yellowtail, black sea bass, eel, silver dollar, brown paku, red paku, cowfish, etc.) or crayfish. Today, the problem of the disease etiology has not been solved; the toxin with the corresponding features has not been isolated, and as a result, causal and pathogenetic treatment of alimentary-toxic paroxysmal myoglobinuria has not been developed. Over this period, several hypotheses were made that are leading in the study of the etiology of the occurrence of Haff disease (thiaminase theory, tannic, arachidonic). This disease-causing substance is known to be heat-resistant and break down the metabolism of skeletal muscles, resulting in the release of myoglobin, which disorders kidney function. It has also been found that toxic substances themselves gradually resolve from the fish, according to its diet (depending on what prevails - plankton, zooplankton or larvae, mollusks, crustaceans). For finding out the origin of the disease, it is essential to conduct comprehensive research by biologists, hydrologists, doctors, and veterinarians.

Rhabdomyolysis with myoglobin-induced acute kidney injury: A case series of four cases

Rhabdomyolysis is a potentially life-threatening clinical syndrome characterized by the breakdown of skeletal muscle cells and release of creatine kinase (CK), lactate dehydrogenase (LDH), and myoglobin into the plasma and interstitial space. Rhabdomyolysis can occur due to a variety of causes and acute kidney injury (AKI) is one of its most dreaded complications occurring in 33%-50% patients. The main pathophysiology of renal injury is due to vasoconstriction, intraluminal casts, tubular obstruction, and direct myoglobin toxicity. As the symptoms are nonspecific, a high level of suspicion is required in the mind of the treating physician. Early diagnosis and prompt management with fluid resuscitation, initiation of renal replacement therapy (RRT), and elimination of causative agents can help prevent complications. We hereby report four interesting cases of this clinical syndrome with emphasis on the causative agents.

P0541KLOTHO IS INVOLVED IN EARLY AND LONG-TERM PROTECTION AGAINST RHABDOMYOLYSIS ASSOCIATED AKI

Abstract Background and Aims Rhabdomyolysis is characterized by the breakdown of the skeletal muscle and the subsequent myoglobin (Mb) release into the bloodstream. A common complication of this syndrome is acute renal injury (AKI). Once filtered by the kidney, Mb causes oxidative stress, inflammation and tubular cell death. There is no specific treatment for rhabdomyolysis-AKI, so it is crucial a better understanding of this syndrome to identify new therapeutic targets. Klotho is an anti-aging protein mostly expressed by the kidney. In addition to its functions in the regulation of mineral metabolism, Klotho protects from AKI-harmful effects. However, no previous studies analyzed the role of Klotho in rhabdomyolysis. Method We performed a pre-clinical model of rhabdomyolysis in C57BL/6J mice (male, 12 weeks old, n=30) by intramuscular injection of 10 ml/kg of 50% glycerol (≥99.5% m/v). Mice were sacrificed 3 and 6 hours or 1, 3, 7 and 30 days after glycerol administration. To evaluate to beneficial effect of Klotho in rhabdomyolysis, C57BL/6J mice were injected intraperitoneally with 0.1 mg/kg recombinant mouse Klotho (1819-KL, R&amp;D Systems), or vehicle (PBS) 30 minutes before and 1, 3 and 5 days after glycerol injection. Blood, urine and renal samples were collected to analyze renal function, Klotho/FGF23 levels, oxidative stress, inflammation, fibrosis and cell death, all of them pathological processes affecting Klotho expression. In addition, we carried out studies in murine tubular cells (MCTs) to study the molecular mechanisms involved in Klotho regulation. Results Our results indicate that rhabdomyolysis induces an early decrease in Klotho renal mRNA and protein expression as well as Klotho serum levels. Klotho levels decreased in line with augmentation of creatinine concentration, kidney inflammation (CCL2 and IL-6 mRNA expression) and tubular injury marker NGAL. Moreover, patients with rhabdomyolysis-AKI also showed lower plasma Klotho levels and increased FGF23 plasma concentration than age-matched healthy individuals. Renal klotho protein expression remained reduced one month after rhabdomyolysis-induction, in line with long term renal fibrosis and pro-inflammatory macrophage accumulation (F4/80+ cells). Exogenous recombinant Klotho administration ameliorated renal function and reduced rhabdomyolysis-mediated tubular cell death oxidative stress (4-HNE staining) and tubular injury 24h after glycerol injection. In the same line, Klotho administration during AKI development reduced long term renal fibrosis and macrophage infiltration one month later. Antioxidant therapies with N-acetylcysteine (NAC) and sulforaphane, a potent Nuclear factor erythroid-2-related factor 2 (Nrf2) inducer, reduced Mb-mediated Klotho decrease in cultured tubular cells. Inhibition of TNF-α and IL-6 with infliximab and tocilizumab, respectively, also reverted Mb-mediated Klotho decrease. Inhibition of the inflammatory NFkB and p38 pathways also prevented Mb-mediated Klotho reduction. Conclusion Our findings are the first to demonstrate decreased renal and soluble Klotho levels not only in the early phases of rhabdomyolysis-induced AKI, but also when renal function was recovered, indicating that long-term consequences of AKI, such as inflammation and fibrosis, are also involved in Klotho downregulation. In addition, our results also indicate that Klotho administration may be a potential strategy to decrease rhabdomyolysis- long term negative effects.

Contrast-Induced Rhabdomyolysis Occurring after ERCP in a Patient with Pancreatic Cancer: A Case Report.

ObjectiveWe present a patient with pancreatic cancer who developed weakness, acute renal failure and significantly raised creatine kinase levels post-ERCP and who was assessed as having contrast-induced rhabdomyolysis.ResultsThe patient underwent haemofiltration and ultimately succumbed to his condition.ConclusionRhabdomyolysis is a potentially life-threatening condition which occurs because of damage to skeletal muscle, with release of myoglobin and electrolytes into the circulation. The mortality rate is 59% in severe cases, despite appropriate treatment.LEARNING POINTSIodine-based contrast can cause rhabdomyolysis by reducing blood flow to the muscle.Renal replacement therapy does not improve the mortality rate of rhabdomyolysis.<10% of patients present with the classic triad of myalgia, muscle weakness and tea-coloured urine; creatine kinase levels greater than 5 times the upper limit of normal are the gold standard for diagnosing rhabdomyolysis that is not related to statin use.

A "crush" course on rhabdomyolysis: risk stratification and clinical management update for the perioperative clinician.

Rhabdomyolysis, the release of myoglobin and other cellular breakdown products from necrotic muscle tissue, is seen in patients with crush injuries, drug overdose, malignant hyperthermia, muscular dystrophy, and with increasing frequency in obese patients undergoing routine procedures. For the perioperative clinician, managing the resultant shock, hyperkalemia, acidosis, and myoglobinuric acute kidney injury can present a significant challenge. Prompt recognition, hydration, and correction of metabolic disturbances may reduce or eliminate the need for long-term renal replacement therapy. This article reviews the pathophysiology and discusses key issues in the perioperative diagnosis, risk stratification, and management of rhabdomyolysis.

Ramipril Blunt Glycerol‐induced Acute Renal Failure in Rats Through its Anti‐apoptosis, Anti‐inflammatory, Anti‐oxidant, and Renin‐inhibiting Properties

Acute Kidney Injury (AKI) is a sudden episode of kidney failure or kidney damage that happens within a few hours or a few days and causes a buildup of waste products in the blood making it hard for the kidney to keep the right balance of fluid in the body. It affects other organs such as the heart, brain and lungs (Schrier et al., 2004). Renal tubular damage is a pathological characteristic of AKI. Currently, animal models of glycerol‐induced AKI are widely used [Mousleh et al 2018]. Glycerol injection into the muscle causes the release of myoglobin and other muscle contents into the circulation, ultimately resulting in AKI. Studies have demonstrated that the pathogenesis of glycerol‐induced AKI involves myoglobin toxicity [Gburek et al 2003; Reeder and Wilson 2005], reactive oxygen species (ROS) [Wu et al 2017], inflammation [ Al Asmari et al 2017], apoptosis [Wang et al 2011] and redox‐active iron [Wu et al 2017].In this study ramipril and pioglitazone (reference drug) were evaluated for their potential therapy in glycerol‐induced AKI in rats. Twenty animals divided into four groups of five animals per group were used. Group I served as control while group II received glycerol on day 8 only. Groups III and IV were administered with pioglitazone and ramipril for 7 days respectively and on day 8 received glycerol. On day 9 blood samples were collected for serum biochemical analysis of markers of oxidative stress, enzymatic and non‐enzymatic antioxidants, creatinine and blood urea nitrogen. Animals were sacrificed thereafter; and kidney tissues were harvested for histopathology and immunohistochemistry. Expression of caspase 3, renin receptor, NK‐KB, and KIM‐1 were carried out.Results from this study show that ramipril and pioglitazone significantly inhibited markers of oxidative stress while also significantly increased the levels of enzymatic and non‐enzymatic anti‐oxidant markers. These drugs caused decreased levels of creatinine and BUN. Histopathologically, there were massive infiltration of leucocytes and congestion of the kidney in toxicant group, but the ramipril treated group showed a milder condition. In immunohistochemistry, the two drugs significantly inhibited the expressions of the four proteins, which were highly expressed in the toxicant group.This study thus showed that ramipril and pioglitazone have nephroprotective effect and thus has ability to blunt acute kidney injury through their anti‐inflammatory, anti‐apoptosis, anti‐renin and anti‐oxidant properties.Support or Funding InformationThis study was supported with a grant (TETFUND/DESS/NRF/UI IBADAN/STI/VOL. 1/B2.20.11) received from the National Research Foundation of the Tertiary Education Trust Fund (TETFUND), Abuja, Nigeria.

Cardiac protection of Bauhinia championii against reperfusion injury.

This study aims to investigate the protective effects of the Bauhinia championii (BC) against ischemia/reperfusion (I/R)-induced injury in an isolated heart model. Langendorff-perfused C57BL/6JNarl mice hearts were performed with 30 minutes ischemia and 60 minutes reperfusion by left anterior descending artery ligation. Before reperfusion, boiling water extracts of BC (10 mg/L) was pretreated for 15 minutes. During reperfusion, BC significantly decreased the occurrence of ventricular arrhythmias by lead II electrocardiogram (ECG). Electrophysiological effect of BC was further determined in isolated ventricular myocytes by whole-cell patch clamp technique. The underlying mechanism may result from its Na+ channel blocking activity characterized with reduced rise slope of action potential and Na+ current density. Moreover, BC dramatically reduced I/R-caused infarct size, which was accessed by 2,3,5-triphenyltetrazolium chloride (TTC) assay. Since BC decreased I/R-induced myoglobin release and oxidation of Ca2+ -calmodulin-dependent protein kinase, inhibition of myocardial necroptosis may account for the protective effects of BC on myocytes lose. This study indicated that BC may prevent I/R induced ventricular arrhythmias and myocyte death by blocking Na+ channels and decreasing necroptosis, respectively. Since most of the available antiarrhythmic remedies have unwanted adverse actions, BC could be a novel candidate for the treatment of myocardial infarction and ventricular arrhythmia.