Influence of short-term chronic oral cannabidiol application on muscle recovery and performance after an intensive training protocol - a randomized double-blind crossover study

BACKGROUND

Rapid regeneration after intense exercise is essential for competitive athletes. Based on this assumption, supplementation strategies, focusing on food supplements, are increasing to improve the recovery processes. One such supplement is cannabidiol (CBD) which is gaining more attention in competitive sports. However, the evidence is still lacking and there are no data available about the effect of a short-term chronic application.

METHODS

A three-arm double-blind cross-over study was conducted to determine the effects of two different CBD products on performance, muscle damage and inflammatory processes in well-trained athletes. In total 17 subjects took successfully part in this study. Each subject underwent the six-day, high-intensity training protocol three times. After each training session, each subject took either a placebo or a CBD product (60 mg of oil or solubilisate). Between the intervention phases, at least four weeks of washout period was conducted. Before and after the training protocols the performance capacity in countermovement jump (CMJ), back squat (BS), bench press (BP) and 1-mile run were measured and biomarkers for muscle damage (creatine kinase, myoglobin), inflammatory processes (interleukin 6 and 10) and immune cell activity (ratios of neutrophil granulocytes, lymphocytes and, platelets) were analyzed. For statistical analyses, the current version of R and a linear mixed model was used.

RESULTS

It could identify different effects of the training protocol depending on performance level (advanced or highly advanced athletes) (p < .05). Regardless of the performance level, muscle damage and a reduction in performance could be induced by the training protocol. Only CBD oil was associated with a reduction in myoglobin concentration (p < .05) in advanced athletes. Concerning immune activity, a significant decrease in platelets lymphocyte ratios was observed in advanced athletes after placebo treatment (p < .05). CBD oil application showed a slight inhibitory effect (p < .10). Moreover, the reduction in performance differs between the performance levels. A significant decrease in CMJ was observed in advanced athletes and a decreasing trend in BS was observed in highly advanced athletes after placebo treatment (p < 0.10). Both CBD products do not affect performance parameters. For inflammatory parameters, no effects were observed.

CONCLUSION

It was found that the performance level of the subjects was a decisive factor and that they responded differently to the training protocol and the CBD application. However, no clear effects of either CBD product were found and further research is needed to identify the long-term effects of CBD application.

Characterization of a novel aspartic protease from Trichoderma asperellum for the preparation of duck blood peptides

A novel aspartic protease gene (TaproA1) from Trichoderma asperellum was successfully expressed in Komagataella phaffii (Pichia pastoris). TaproA1 showed 52.8% amino acid sequence identity with the aspartic protease PEP3 from Coccidioides posadasii C735. TaproA1 was efficiently produced in a 5 L fermenter with a protease activity of 4092 U/mL. It exhibited optimal reaction conditions at pH 3.0 and 50 °C and was stable within pH 3.0-6.0 and at temperatures up to 45 °C. The protease exhibited broad substrate specificity with high hydrolysis activity towards myoglobin and hemoglobin. Furthermore, duck blood proteins (hemoglobin and plasma protein) were hydrolyzed by TaproA1 to prepare bioactive peptides with high ACE inhibitory activity. The IC50 values of hemoglobin and plasma protein hydrolysates from duck blood proteins were 0.105 mg/mL and 0.091 mg/mL, respectively. Thus, the high yield and excellent biochemical characterization of TaproA1 presented here make it a potential candidate for the preparation of duck blood peptides. KEY POINTS: • An aspartic protease (TaproA1) from Trichoderma asperellum was expressed in Komagataella phaffii. • TaproA1 exhibited broad substrate specificity and the highest activity towards myoglobin and hemoglobin. • TaproA1 has great potential for the preparation of bioactive peptides from duck blood proteins.

Rapid diagnosis of acute myocardial infarction through integrated microfluidic chips for detection of characteristic targets

Myoglobin (Myo), creatine kinase-MB (CKMB), and cardiac troponin I (cTnI) are crucial biomarkers for diagnosing acute myocardial infarction (AMI) The accurate and rapid detection of these three targets can greatly improve the prognosis of AMI patients. Herein, this study developed a microfluidic immunofluorescence method that can detect all three targets in 10-15 min. Ultrasonic atomization and spray technology are used to modify the surface of the injection-molded microfluidic chip (MFC), which effectively solves the problem of biological cross-linking and antibody immobilization on the MFC surface. In addition, it improves the hydrophilicity of the chip surface, thus enhancing fluid self-driving effect. The linear response towards Myo, CKMB and cTnI range from 5 ng/mL to 500 ng/mL, 1 ng/mL to 70 ng/mL, and 0.05 ng/mL to 30 ng/mL, respectively. The intra-batch precision is ≤ 10%, and the inter-batch precision is ≤ 15%. Furthermore, this method shows good consistency compared with the BECKMAN ACCESS2 chemiluminescent immunoanalyzer. The present work provides an AMI diagnostic method with high sensitivity, good repeatability, high accuracy and simple operation, which can satisfy the needs of clinical diagnosis, and shows promising application prospects.

Absolute protein quantification based on calibrated particle counting using electrospray-differential mobility analysis

The traceability of in vitro diagnostics or drug products is based on the accurate quantification of proteins. In this study, we developed an absolute quantification approach for proteins. This method is based on calibrated particle counting using electrospray-differential mobility analysis (ES-DMA) coupled with a condensation particle counter (CPC). The absolute concentration of proteins was quantified with the observed protein particle number measured with ES-DMA-CPC, and the detection efficiency was determined by calibrators. The measurement performance and quantitative level were verified using two certificated reference materials, BSA and NIMCmAb. The linear regression fit for the detection efficiency values of three reference materials and one highly purified protein (myoglobin, BSA, NIMCmAb and fibrinogen) indicated that the detection efficiency and the particle size distribution of these proteins exhibited a linear relationship. Moreover, to explore the suitability of the detection efficiency-particle size curve for protein quantification, the concentrations of three typical proteinaceous particles, including two high molecular weight proteins (NIST reference material 8671 and D-dimer) and one protein complex (glutathione S-transferase dimer), were determined. This work suggests that this calibrated particle counting method is an efficient approach for nondestructive, rapid and accurate quantification of proteins, especially for measuring proteinaceous particles with tremendous size and without reference standards.

Sandwich-type electrochemical aptasensor for sensitive detection of myoglobin based on Pt@CuCo-oxide nanoparticles as a signal marker

When an acute myocardial infarction (AMI) occurs, myoglobin (Mb) is the biomarker whose concentration firstly increases, and the high sensitive detection of Mb is critical for early diagnosis of AMI. Herein, a sandwich-type electrochemical aptasensor for the sensitive detection of Mb was constructed by using Pt@Cu1.33OCo0.83O as the signal marker. On one hand, nano-flower-like Cu1.33OCo0.83O was synthesized by hydrothermal method and Pt nanoparticles (Pt NPs) were loaded on its surface. Pt@Cu1.33OCo0.83O could immobilize aptamer 2 (Apt2) successfully by the Pt-S bond. And because of the synergistic effect between Pt and bimetallic oxide, Pt@Cu1.33OCo0.83O had an excellent catalytic effect on the signal source of hydrogen peroxide (H2O2) to amplify the current signal, which enhance the sensitivity of the aptasensor. On the other hand, the screen-printed gold electrode (SPGE) was used as the sensing base, which had good conductivity and ensured the immobilization of aptamer 1 (Apt1). The quantitative detection of Mb was achieved by specific recognition between Mb and Apt1, Apt2. As a result, the constructed electrochemical aptasensor had a good linear range (1-1500 ng/mL) with a low detection limit (LOD) of 0.128 ng/mL (S/N = 3), and a high sensitivity of 29.47 μA dec-1. The aptasensor also realized the detection of Mb in human serum samples with good accuracy, and the results were consistent with the hospital's biochemical indicators, which demonstrated the potential application of the prepared sensor in the clinical detection of Mb.

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

PURPOSE

This study examined the magnitude of physiological strain imposed by repeated maximal static and dynamic apneas through assessing a panel of stress-related biomarkers.

METHODS

Eleven 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.

RESULTS

IMA 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).

CONCLUSIONS

Five repeated maximal DYN led to a greater muscle injury compared with STA but neither elicited myocardial injury or neuronal-parenchymal damage.

Radiolysis of myoglobin concentrated gels by protons: specific changes in secondary structure and production of carbon monoxide

While particle therapy has been used for decades for cancer treatment, there is still a lack of information on the molecular mechanisms of biomolecules radiolysis by accelerated ions. Here, we examine the effects of accelerated protons on highly concentrated native myoglobin, by means of Fourier transform infrared and UV-Visible spectroscopies. Upon irradiation, the secondary structure of the protein is drastically modified, from mostly alpha helices conformation to mostly beta elements at highest fluence. These changes are accompanied by significant production of carbon monoxide, which was shown to come from heme degradation under irradiation. The radiolytic yields of formation of denatured protein, carbon monoxide, and of heme degradation were determined, and found very close to each other: G+denatured Mb ≈ G+CO ≈ G-heme = 1.6 × 10-8 ± 0.1 × 10-8 mol/J = 0.16 ± 0.01 species/100 eV. The denaturation of the protein to a beta structure and the production of carbon monoxide under ion irradiation are phenomena that may play an important role in the biological effects of ionizing radiation.

Advances in research on biomarkers associated with acute myocardial infarction: A review

Acute myocardial infarction (AMI), the most severe cardiovascular event in clinical settings, imposes a significant burden with its annual increase in morbidity and mortality rates. However, it is noteworthy that mortality due to AMI in developed countries has experienced a decline, largely attributable to the advancements in medical interventions such as percutaneous coronary intervention. This trend highlights the importance of accurate diagnosis and effective treatment to preserve the myocardium at risk and improve patient outcomes. Conventional biomarkers such as myoglobin, creatine kinase isoenzymes, and troponin have been instrumental in the diagnosis of AMI. However, recent years have witnessed the emergence of new biomarkers demonstrating the potential to further enhance the accuracy of AMI diagnosis. This literature review focuses on the recent advancements in biomarker research in the context of AMI diagnosis.

Myoglobin improves doxycycline sensitivity in pancreatic cancer through promoting heme oxygenase-1-mediated ferroptosis

Ferroptosis is expected to be a therapeutic target for cancers including pancreatic cancer. We aimed to screen genes that regulate ferroptosis and doxycycline resistance in pancreatic cancer and to explore the underlying mechanisms. Bioinformatics analysis was performed to identify genes that respond to ferroptosis in two human pancreatic cancer cells with GOT1 knocked down or not. 325 and 842 genes were upregulated in MiaPaCa and Tu8902 cells in response to GOT1 knockdown, with 43 genes shared. Among the 43 genes, 14 genes were identified to interact with ferroptosis key genes. MB and HMOX1 were the genes most sensitive to Erastin and doxycycline. Moreover, MB and HMOX1 expression was higher in human normal pancreatic duct epithelial cells than in pancreatic cancer cells. MB and HMOX1 proteins physically bound and promoted each other's expression. By interacting with HMOX1, MB suppressed pancreatic cancer cell proliferation, colony formation and invasion, and promoted cell ferroptosis and sensitivity to erastin and doxycycline. Silencing HMOX1 reversed the promoting effect of MB on cell ferroptosis and sensitivity to doxycycline. A pancreatic cancer xenograft model was established by subcutaneous injection of Panc-1 cells transfected with or without Ad-MB, and doxycycline was administered intraperitoneally. Overexpression of MB enhanced the inhibitory effect of doxycycline on xenograft growth. In conclusion, MB facilitated doxycycline sensitivity in pancreatic cancer cells through promoting HMOX1-mediated ferroptosis.

Synthesis of carbon nanotubes-chitosan nanocomposite and immunosensor fabrication for myoglobin detection: An acute myocardial infarction biomarker

The use of single-walled carbon nanotubes (SWCNTs) in biomedical applications is limited due to their inability to disperse in aqueous solutions. In this study, dispersed -COOH functionalized CNTs with N-succinylated chitosan (CS), greatly increasing the water solubility of CNTs and forming a uniformly dispersed nanocomposite solution of CNTs@CS. Coupling reagent EDC/NHS was used as a linker with the -COOH groups present on the N-succinylated chitosan which significantly improved the affinity of the CNTs for biomolecules. Myoglobin (Mb) is a promising biomarker for the precise assessment of cardiovascular risk, type 2 diabetes, metabolic syndrome, hypertension and several types of cancer. A high level of Mb can be used to diagnose the mentioned pathogenic diseases. The CNTs@CS-FET demonstrates superior sensing performance for Mb antigen fortified in buffer, with a wide linear range of 1 to 4000 ng/mL. The detection limit of the developed Mb immunosensor was estimated to be 4.2 ng/mL. The novel CNTs@CS-FET immunosensor demonstrates remarkable capability in detecting Mb without being affected by interferences from nonspecific antigens. Mb spiked serum showed a recovery rate of 100.262 to 118.55 % indicating great promise for Mb detection in clinical samples. The experimental results confirmed that the CNTs@CS-FET immunosensor had excellent selectivity, reproducibility and storage stability.

[Multicenter retrospect analysis of early clinical features and analysis of risk factors on prognosis of elderly patients with severe burns]

Objective: To investigate the early clinical characteristics of elderly patients with severe burns and the risk factors on prognosis. Methods: This study was a retrospective case series study. Clinical data of 124 elderly patients with severe burns who met the inclusion criteria and were admitted to the 12 hospitals from January 2015 to December 2020 were collected, including 4 patients from the Fourth People's Hospital of Dalian, 5 patients from Fujian Medical University Union Hospital, 22 patients from Guangzhou Red Cross Hospital of Jinan University, 5 patients from Heilongjiang Provincial Hospital, 27 patients from the First Affiliated Hospital of Naval Medical University, 9 patients from the First Affiliated Hospital of Nanchang University, 10 patients from Affiliated Hospital of Nantong University, 9 patients from Tongren Hospital of Wuhan University & Wuhan Third Hospital, 12 patients from the 924th Hospital of PLA, 6 patients from Zhangjiagang First People's Hospital, 4 patients from Taizhou Hospital of Zhejiang Province, and 11 patients from Zhengzhou First People's Hospital. The patients' overall clinical characteristics, such as gender, age, body mass index, total burn area, full-thickness burn area, inhalation injury, causative factors, whether combined with underlying medical diseases, and admission time after injury were recorded. According to the survival outcome within 28 days after injury, the patients were divided into survival group (89 cases) and death group (35 cases). The following data of patients were compared between the two groups, including the basic data and injuries (the same as the overall clinical characteristics ahead); the coagulation indexes within the first 24 hours of injury such as prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time, D-dimer, fibrinogen degradation product (FDP), international normalized ratio (INR), and fibrinogen; the blood routine indexes within the first 24 hours of injury such as white blood cell count, platelet count, neutrophil-to-lymphocyte ratio, monocyte count, red blood cell count, hemoglobin, and hematocrit; the organ function indexes within the first 24 hours of injury such as direct bilirubin, total bilirubin, urea, serum creatinine, aspartate aminotransferase, alanine aminotransferase, total protein, albumin, globulin, blood glucose, triglyceride, total cholesterol, alkaline phosphatase, creatine kinase, electrolyte indexes (potassium, sodium, chlorine, calcium, magnesium, and phosphorus in blood), uric acid, myoglobin, and brain natriuretic peptide; the infection and blood gas indexes within the first 24 hours of injury such as procalcitonin, C-reactive protein, pH value, oxygenation index, base excess, and lactate; treatment such as whether conducted with mechanical ventilation, whether conducted with continuous renal replacement therapy, whether conducted with anticoagulation therapy, whether applied with vasoactive drugs, and fluid resuscitation. The analysis was conducted to screen the independent risk factors for the mortality within 28 days after injury in elderly patients with severe burns. Results: Among 124 patients, there were 82 males and 42 females, aged 60-97 years, with body mass index of 23.44 (21.09, 25.95) kg/m2, total burn area of 54.00% (42.00%, 75.00%) total body surface area (TBSA), and full-thickness burn area of 25.00% (10.00%, 40.00%) TBSA. The patients were mainly combined with moderate to severe inhalation injury and caused by flame burns. There were 43 cases with underlying medical diseases. The majority of patients were admitted to the hospital within 8 hours after injury. There were statistically significant differences between patients in the 2 groups in terms of age, total burn area, full-thickness burn area, and inhalation injury, and PT, APTT, D-dimer, FDP, INR, white blood cell count, platelet count, urea, serum creatinine, blood glucose, blood sodium, uric acid, myoglobin, and urine volume within the first 24 hours of injury (with Z values of 2.37, 5.49, 5.26, 5.97, 2.18, 1.95, 2.68, 2.68, 2.51, 2.82, 2.14, 3.40, 5.31, 3.41, 2.35, 3.81, 2.16, and -3.82, respectively, P<0.05); there were statistically significant differences between two groups of patients in whether conducted with mechanical ventilation and whether applied with vasoactive drugs (with χ2 values of 9.44 and 28.50, respectively, P<0.05). Age, total burn area, full-thickness burn area, serum creatinine within the first 24 hours of injury, and APTT within the first 24 hours of injury were the independent risk factors for the mortality within 28 days after injury in elderly patients with severe burns (with odds ratios of 1.17, 1.10, 1.10, 1.09, and 1.27, 95% confidence intervals of 1.03-1.40, 1.04-1.21, 1.05-1.19, 1.05-1.17, and 1.07-1.69, respectively, P<0.05). Conclusions: The elderly patients with severe burns had the injuries mainly from flame burns, often accompanied by moderate to severe inhalation injury and enhanced inflammatory response, elevated blood glucose levels, activated fibrinolysis, and impaired organ function in the early stage, which are associated with their prognosis. Age, total burn area, full-thickness burn area, and serum creatinine and APTT within the first 24 hours of injury are the independent risk factors for death within 28 days after injury in this population.

Blood oxygen transport and depletion in diving emperor penguins

Oxygen store management underlies dive performance and is dependent on the slow heart rate and peripheral vasoconstriction of the dive response to control tissue blood flow and oxygen uptake. Prior research has revealed two major patterns of muscle myoglobin saturation profiles during dives of emperor penguins. In Type A profiles, myoglobin desaturated rapidly, consistent with minimal muscle blood flow and low tissue oxygen uptake. Type B profiles, with fluctuating and slower declines in myoglobin saturation, were consistent with variable tissue blood flow patterns and tissue oxygen uptake during dives. We examined arterial and venous blood oxygen profiles to evaluate blood oxygen extraction and found two primary patterns of venous hemoglobin desaturation that complemented corresponding myoglobin saturation profiles. Type A venous profiles had a hemoglobin saturation that (a) increased/plateaued for most of a dive's duration, (b) only declined during the latter stages of ascent, and (c) often became arterialized [arterio-venous (a-v) shunting]. In Type B venous profiles, variable but progressive hemoglobin desaturation profiles were interrupted by inflections in the profile that were consistent with fluctuating tissue blood flow and oxygen uptake. End-of-dive saturation of arterial and Type A venous hemoglobin saturation profiles were not significantly different, but did differ from those of Type B venous profiles. These findings provide further support that the dive response of emperor penguins is a spectrum of cardiac and vascular components (including a-v shunting) that are dependent on the nature and demands of a given dive and even of a given segment of a dive.

Characteristics and molecular properties of crude hemeproteins extracted from Asian seabass gills using an ultrasound-assisted process

BACKGROUND

The development of a safe and effective iron supplement is important for the treatment of iron-deficient anemia. Therefore, the crude hemeprotein extract (CHPE) from Asian seabass gills was extracted without (CON) and with ultrasound (US)-assisted process, followed by freeze-drying. The resulting freeze-dried crude hemeprotein extract (FDCHPE) powders were determined for trace mineral content, color, secondary structure, protein pattern, size distribution, volatile compounds, and amino acid composition.

RESULTS

The extraction yields of CON-FDCHPE and US-FDCHPE were 6.76% and 13.65%, respectively. Highest heme iron (0.485 mg/mL) and non-heme iron (0.023 mg/mL) contents were found when US at 70% amplitude for 10 min (US 70/10) was applied. Both CON-FDCHPE and US-FDCHPE had no heavy metals, but higher iron content (432.8 mg/kg) was found in US-FDCHPE (P < 0.05). Typical red color was observed in CON-FDCHPE and US-FDCHPE with a*-values of 9.72 and 10.60, respectively. Ultrasonication affected protein structure, in which β-sheet upsurged, whereas random coil, α-helix, and β-turn were reduced. Protein pattern confirmed that both samples had myoglobin as the major protein. US-FDCHPE also showed a higher abundance of volatile compounds, especially propanal, hexanal, heptanal, and so forth, compared to CON-FDCHPE. Amino acid composition of US-FDCHPE was comparable to Food and Agriculture Organization of the United Nations (FAO) values.

CONCLUSION

Overall, FDCHPE extracted using ultrasonication could be safe and effective for fortification in food products as an iron supplement to alleviate iron-deficient anemia. Additionally, gills as leftovers could be better exploited rather than being disposed. © 2023 Society of Chemical Industry.

Kidney replacement and conservative therapies in rhabdomyolysis: a retrospective analysis

BACKGROUND

Toxic renal effects of myoglobin following rhabdomyolysis can cause acute kidney injury (AKI) with the necessity of kidney replacement therapy (KRT). Fast elimination of myoglobin seems notable to save kidney function and intensify kidney repair. Clinical data regarding efficacy of KRT in critical care patients with rhabdomyolysis and AKI are limited. This retrospective analysis aimed to identify differences between conservative therapy and different modalities of KRT regarding myoglobin elimination and clinical outcome.

METHODS

This systematic, retrospective, single-center study analyzed 328 critical care patients with rhabdomyolysis (myoglobin > 1000 µg/l). Median reduction rate of myoglobin after starting KRT was calculated and compared for different modalities. Multivariate logistic regression models were established to identify potential confounder on hospital mortality. Filter lifetime of the various extracorporeal circuits was analyzed by Kaplan-Meier curves.

RESULTS

From 328 included patients 171 required KRT. Health condition at admission of this group was more critical compared to patient with conservative therapy. Myoglobin reduction rate did not differ between the groups (KRT 49% [30.8%; 72.2%] vs. conservative treatment (CT) 61% [38.5%; 73.5%]; p = 0.082). Comparison between various extracorporeal procedures concerning mortality showed no significant differences. Hospital mortality was 55.6% among patients with KRT and 18.5% with CT (p < 0.001). Multivariate logistic regression model identified requirement for KRT (OR: 2.163; CI: 1.061-4.407); p = 0.034) and the SOFA Score (OR: 1.111; CI: 1.004-1.228; p = 0.041) as independent predictive factors for hospital mortality. When comparing specific KRT using multivariate regression, no benefit was demonstrated for any treatment modality. Life span of the extracorporeal circuit was shorter with CVVH compared to that of others (log-Rank p = 0.017).

CONCLUSIONS

This study emphasizes that AKI requiring KRT following rhabdomyolysis is accompanied by high mortality rate. Differences in myoglobin reduction rate between various KRTs could not be confirmed, but CVVH was associated with reduced filter lifetime compared to other KRTs, which enable myoglobin elimination, too.

Elevated plasma myoglobin level is closely associated with type 2 diabetic kidney disease

BACKGROUND

Diabetic kidney disease (DKD) is the most frequent complication in patients with type 2 diabetes mellitus (T2DM). It causes a chronic and progressive decline in kidney function, and ultimately patients require renal replacement therapy. To date, an increasing number of clinical studies have been conducted to explore the potential and novel biomarkers, which can advance the diagnosis, estimate the prognosis, and optimize the therapeutic strategies at the early stage of DKD. In the current study, we sought to investigate the association of plasma myoglobin with DKD.

METHODS

A total of 355 T2DM patients with DKD and 710 T2DM patients without DKD were enrolled in this study. Laboratory parameters including blood cell count, hemoglobin A1c, biochemical parameters, and plasma myoglobin were recorded. Patients were classified on admission according to the tertile of myoglobin and clinical parameters were compared between the groups. Pearson correlation analysis, linear regression, logistic regression, receiver operating characteristics (ROC) analysis, and spline regression were performed.

RESULTS

Plasma myoglobin significantly increased in patients with DKD and was associated with renal function and inflammatory parameters. Plasma myoglobin was an independent risk factor for the development of DKD. The area under ROC curve of myoglobin was 0.831. Spline regression showed that there was a significant linear association between DKD incidence and a high level of plasma myoglobin when it exceeded 36.4 mg/mL.

CONCLUSIONS

This study shows that elevated plasma myoglobin level is closely associated with the development of kidney injury in patients with T2DM.

Rhabdomyolysis caused by Botrychium ternatum intoxication: Case report and literature review

RATIONALE

Botrychium ternatum ((Thunb.) Sw.), a traditional Chinese medicine, is known for its therapeutic properties in clearing heat, detoxifying, cough suppression, and phlegm elimination. It has been extensively used in clinics for the treatment of many inflammation-related diseases. Currently, there are no documented cases of rhabdomyolysis resulting from Botrychium ternatum intoxication.

PATIENT CONCERNS

A 57-year-old male presented with a complaint of low back discomfort accompanied by tea-colored urine lasting for 4 days. The patient also exhibited markedly increased creatine phosphate kinase and myoglobin levels. Prior to the onset of symptoms, the patient consumed 50 g of Botrychium ternatum to alleviate pharyngodynia.

DIAGNOSES

The patient was diagnosed with rhabdomyolysis due to Botrychium ternatum intoxication.

INTERVENTIONS

The patient underwent a substantial volume of fluid resuscitation, diuresis, and alkalization of urine, as well as correction of the acid-base balance and electrolyte disruption.

OUTCOMES

Following a 10-day treatment plan involving massive fluid resuscitation, diuresis, and alkalization of urine, the patient showed notable improvement in his lower back pain and reported the absence of any discomfort. Following reexamination, the levels of creatine phosphate kinase and myoglobin were restored to within the normal ranges. Additionally, no abnormalities were detected in liver or renal function. As a result, the patient was considered eligible for discharge and was monitored.

CONCLUSIONS

Botrychium ternatum intoxication was associated with the development of rhabdomyolysis. To manage this condition, it is recommended that patients provide massive fluid resuscitation, diuresis, alkalization of urine, and other appropriate therapeutic interventions.

LESSON

Currently, there are no known cases of rhabdomyolysis resulting from Botrychium ternatum intoxication. However, it is important to consider the potential occurrence of rhabdomyolysis resulting from Botrychium ternatum intoxication when there is a correlation between the administration of Botrychium ternatum and the presence of muscular discomfort in the waist or throughout the body, along with tea-colored urine. Considering the levels of creatine phosphate kinase and myoglobin, the diagnosis or exclusion of rhabdomyolysis caused by Botrychium ternatum intoxication should be made, and suitable treatment should be administered accordingly.

Matrix Selection Strategies for MALDI-TOF MS/MS Characterization of Cyclic Tetrapyrroles in Blood and Food Samples

Cyclic tetrapyrrole derivatives such as porphyrins, chlorins, corrins (compounds with a corrin core), and phthalocyanines are a family of molecules containing four pyrrole rings usually coordinating a metal ion (Mg, Cu, Fe, Zn, etc.). Here, we report the characterization of some representative cyclic tetrapyrrole derivatives by MALDI-ToF/ToF MS analyses, including heme b and c, phthalocyanines, and protoporphyrins after proper matrix selection. Both neutral and acidic matrices were evaluated to assess potential demetallation, adduct formation, and fragmentation. While chlorophylls exhibited magnesium demetallation in acidic matrices, cyclic tetrapyrroles with Fe, Zn, Co, Cu, or Ni remained steadfast against demetallation across all conditions. Phthalocyanines and protoporphyrins were also detectable without a matrix using laser desorption ionization (LDI); however, the incorporation of matrices achieved the highest ionization yield, enhanced sensitivity, and negligible fragmentation. Three standard proteins, i.e., myoglobin, hemoglobin, and cytochrome c, were analyzed either intact or enzymatically digested, yielding heme b and heme c ions along with accompanying peptides. Furthermore, we successfully detected and characterized heme b in real samples, including blood, bovine and cod liver, and mussel. As a result, MALDI MS/MS emerged as a powerful tool for straightforward cyclic tetrapyrrole identification, even in highly complex samples. Our work paves the way for a more comprehensive understanding of cyclic tetrapyrroles in biological and industrial settings, including the geochemical field, as these compounds are a source of significant geological and geochemical information in sediments and crude oils.

Stabilization of myoglobin from different species (produced by cellular agriculture) using food-grade natural and synthetic antioxidants

Cellular agriculture products, like myoglobin, are increasingly used by the food industry to provide desirable sensory properties to plant-based meat substitutes. This study elucidated the physicochemical properties and redox stability of myoglobin from both natural (equine) and cellular agriculture (bovine, sperm whale, and leopard) sources. The electrical characteristics and water-solubility of the different myoglobin samples were measured from pH 2.5 to 8.5. The isoelectric point of the myoglobin samples depended on the species, being pH 5.5 for equine, pH 4.5 for leopard and bovine, and pH 6.5 for sperm whale. All myoglobin samples had a solubility greater than 80% across the entire pH range studied. All myoglobin solutions appeared red and had two peaks in their UV-visible absorbance spectra after one day, which is consistent with oxymyoglobin formation. Equine myoglobin at pH 8 was selected to study its redox and color stability over time, where the oxymyoglobin oxidative status closely paralleled with the redness of the solutions. The effects of antioxidants (ascorbic acid, caffeic acid, catechin, gallic acid, quercetin, taxifolin, Trolox, and 4-methylcatechol) on the redox and color stability (redness) of the equine myoglobin (pH 8.0) was also studied. Antioxidants with low reduction potential values (ascorbic acid and quercetin) were particularly effective at enhancing the color stability of oxymyoglobin. The computational modeling study showed that amino acids on the myoglobin interacted with antioxidants through hydrogen bonds. The insights obtained may have important implications for the use of cellular agriculture to produce myoglobin for food applications.

Redox differences between rat neonatal and adult cardiomyocytes under hypoxia

It is generally accepted that oxidative stress plays a key role in the development of ischemia-reperfusion injury in ischemic heart disease. However, the mechanisms how reactive oxygen species trigger cellular damage are not fully understood. Our study investigates redox state and highly reactive substances within neonatal and adult cardiomyocytes under hypoxia conditions. We have found that hypoxia induced an increase in H2O2 production in adult cardiomyocytes, while neonatal cardiomyocytes experienced a decrease in H2O2 levels. This finding correlates with our observation of the difference between the electron transport chain (ETC) properties and mitochondria amount in adult and neonatal cells. We demonstrated that in adult cardiomyocytes hypoxia caused the significant increase in the ETC loading with electrons compared to normoxia. On the contrary, in neonatal cardiomyocytes ETC loading with electrons was similar under both normoxic and hypoxic conditions that could be due to ETC non-functional state and the absence of the electrons transfer to O2 under normoxia. In addition to the variations in H2O2 production, we also noted consistent pH dynamics under hypoxic conditions. Notably, the pH levels exhibited a similar decrease in both cell types, thus, acidosis is a more universal cellular response to hypoxia. We also demonstrated that the amount of mitochondria and the levels of cardiac isoforms of troponin I, troponin T, myoglobin and GAPDH were significantly higher in adult cardiomyocytes compared to neonatal ones. Remarkably, we found out that under hypoxia, the levels of cardiac isoforms of troponin T, myoglobin, and GAPDH were elevated in adult cardiomyocytes, while their level in neonatal cells remained unchanged. Obtained data contribute to the understanding of the mechanisms of neonatal cardiomyocytes' resistance to hypoxia and the ability to maintain the metabolic homeostasis in contrast to adult ones.

Absolute Quantification of Human Serum Albumin Isoforms by Internal Calibration Based on a Top-Down LC-MS Approach

Well-characterized biomarkers using reliable quantitative methods are essential for the management of various pathologies such as diabetes, kidney, and liver diseases. Human serum albumin (HSA) isoforms are gaining interest as biomarkers of advanced liver pathologies. In view of the structural alterations observed for HSA, insights into its isoforms are required to establish them as reliable biomarkers. Therefore, a robust absolute quantification method seems necessary. In this study, we developed and validated a far more advanced top-down liquid chromatography-mass spectrometry (LC-MS) method for the absolute quantification of HSA isoforms, using myoglobin (Mb) as an internal standard for quantification and for mass recalibration. Two different quantification approaches were investigated based on peak integration from the deconvoluted spectrum and extracted ion chromatogram (XIC). The protein mixture human serum albumin/myoglobin eluted in well-shaped separated peaks. Mb allowed a systematic mass recalibration for every sample, resulting in extremely low mass deviations compared to conventional deconvolution-based methods. In total, eight HSA isoforms of interest were quantified. Specific-isoform calibration curves showing good linearity were obtained by using the deconvoluted peaks. Noticeably, the HSA ionization behavior appeared to be isoform-dependent, suggesting that the use of an enriched isoform solution as a calibration standard for absolute quantification studies of HSA isoforms is necessary. Good repeatability, reproducibility, and accuracy were observed, with better sensitivity for samples with low albumin concentrations compared to routine biochemical assays. With a relatively simple workflow, the application of this method for absolute quantification shows great potential, especially for HSA isoform studies in a clinical context, where a high-throughput method and sensitivity are needed.

Predicting Acute Kidney Injury in Trauma Patients: Biomarkers as Early Indicators

BACKGROUND Acute kidney injury (AKI) is a common cause of organ failure in patients after major trauma and is associated with increased morbidity and mortality. Early identification of patients at risk enables the implementation of a bundle of supportive care, which reduces the incidence of AKI. The primary objective of our study was to investigate whether the levels of biomarkers on admission predicted the onset of early AKI in patients with serious injuries. MATERIAL AND METHODS This prospective observational study included 98 adult patients of both sexes with a serious injury (injury severity score >16). At admission, blood samples were taken, and creatinine, neutrophil gelatinase-associated lipocalin (NGAL), high mobility group box 1 (HMGB-1), and markers of rhabdomyolysis (creatine kinase, myoglobin) were evaluated. The patients were provided with standard resuscitation care, and the occurrence of AKI was monitored during the first 7 days after admission to the Intensive Care Unit, according to the Kidney Disease Improving Global Outcomes diagnostic criteria. RESULTS AKI occurred in 25 (25.5%) patients, in whom the admission levels of HMGB-1, NGAL, creatinine, and myoglobin were significantly higher than in non-AKI patients (48.3±98.4 vs 113.0±209.4 µg/L, P=0.006; 150.2±349.9 vs 181.4±152.2 µg/L, P=0.004; 83.1±20.8 vs 118.8±32.2 µmol/L, P<0.005; 2734.4±2214.5 vs 4182.3±2477.1 µg/L, P=0.008, respectively). Creatine kinase was 14.5±9.2 µkat/L in non-AKI patients and 13.7±7.9 µkat/L in AKI patients (P=0.916). CONCLUSIONS Admission levels of HMGB-1, NGAL, creatinine, and myoglobin predicted the risk of AKI in severely injured patients.

Smartphone-Aided Fluorescence Detection of Cardiac Biomarker Myoglobin by a Ratiometric Fluorescent AuNCs-QDs Nanohybrids Probe with High Sensitivity

Simple and sensitive detection of cardiac biomarkers is of great significance for early diagnosis and prevention of acute myocardial infarction (AMI). Here, a ratiometric fluorescent nanohybrids probe (AuNCs-QDs) was synthesized through the coupling of bovine serum albumin-functionalized gold nanoclusters (AuNCs) with CdSe/ZnS quantum dots (QDs) to realize simple and sensitive detection of cardiac biomarker myoglobin (Mb). The AuNCs-QDs probe shows pink fluorescence under UV light, with two emission peaks at 468 nm and 630 nm belonging to QDs and AuNCs, respectively. Importantly, the presence of Mb caused fluorescence quenching of the blue-emitting QDs, thereby inhibiting the fluorescence resonance energy transfer (FRET) process between QDs and AuNCs, and reducing the fluorescence intensity ratio (F468/F630) of AuNCs-QDs probe effectively. As the concentration of Mb increases, the ratiometric fluorescent probe also exhibits a visible fluorescence color change. The detection limit was as low as 4.99 μg/mL, and the response of the probe to Mb showed a good linear relationship up to 0.52 mg/mL. Moreover, the probe has excellent specificity for Mb. Besides, the AuNCs-QDs has been applied to detect Mb of urine samples. More importantly, we also developed an AuNCs-QDs probe modified smartphone-aided paper-based strip for on-site monitoring of Mb. As far as we know, this is the first report of a smartphone-aided paper-based strip for on-site quick monitoring of Mb, which provides a useful approach for AMI biomarker monitoring and may can be extended to other medical diagnostics.

Case Report: An Imported Case of Typhoid Fever Combined with Rhabdomyolysis and Multiple Organ Lesions in China

Here, we report a case of blood culture-confirmed typhoid fever, rhabdomyolysis, and multiple organ damage that arrived in our country from overseas. A 23-year-old male patient presented at our hospital with fever and muscle pain; the condition progressed rapidly. Six days after the onset of symptoms, the patient developed rhabdomyolysis and liver/kidney damage; levels of creatine kinase (CK; maximum peak: 729,869 U/L) and myoglobin (> 3,000 ng/mL) were extremely high, although the extent of renal damage was relatively mild. Blood culture showed Salmonella typhi. The patient received a combination of meropenem and levofloxacin anti-infective therapy, as well as fluid and nutritional metabolic support. He gradually recovered and was discharged after two negative blood cultures. This case highlights the fact that typhoid-induced rhabdomyolysis is a serious, life-threatening disease and that the levels of CK and myoglobin are useful indicators for evaluating typhoid-induced rhabdomyolysis. Clinicians should remain vigilant regarding travel-related illnesses associated with enteric fever.

Ferroptosis in acute kidney injury following crush syndrome: A novel target for treatment

BACKGROUND

Crush syndrome (CS) is a kind of traumatic and ischemic injury that seriously threatens life after prolonged compression. It is characterized by systemic inflammatory reaction, myoglobinuria, hyperkalemia and acute kidney injury (AKI). Especially AKI, it is the leading cause of death from CS. There are various cell death forms in AKI, among which ferroptosis is a typical form of cell death. However, the role of ferroptosis has not been fully revealed in CS-AKI.

AIM OF REVIEW

This review aimed to summarize the evidence of ferroptosis in CS-AKI and its related molecular mechanism, discuss the therapeutic significance of ferroptosis in CS-AKI, and open up new ideas for the treatment of CS-AKI.

KEY SCIENTIFIC CONCEPTS OF REVIEW

One of the main pathological manifestations of CS-AKI is renal tubular epithelial cell dysfunction and cell death, which has been attributed to massive deposition of myoglobin. Large amounts of myoglobin released from damaged muscle deposited in the renal tubules, impeding the normal renal tubules function and directly damaging the tubules with oxidative stress and elevated iron levels. Lipid peroxidation damage and iron overload are the distinguishing features of ferroptosis. Moreover, high levels of pro-inflammatory cytokines and damage-associated molecule pattern molecules (HMGB1, double-strand DNA, and macrophage extracellular trap) in renal tissue have been shown to promote ferroptosis. However, how ferroptosis occurs in CS-AKI and whether it can be a therapeutic target remains unclear. In our current work, we systematically reviewed the occurrence and underlying mechanism of ferroptosis in CS-AKI.

Assessment of selected muscle damage markers and zonulin concentration after maximum-intensity exercise in men with type 1 diabetes treated with a personal insulin pump

AIM

Exercise-induced muscle damage depends on exercise intensity and duration and on individual susceptibility. Mechanical and metabolic stress may disturb the intestinal microflora. The study evaluated selected muscle damage markers and zonulin concentration after maximum-intensity exercise in type 1 diabetes (T1D) men compared with healthy controls.

METHODS

The study involved 16 T1D participants and 28 controls matched by age (22.7 [21.3-25.1] vs. 22.6 [20.9-26.3] years), body mass index (24.2 ± 1.6 vs. 24.2 ± 1.9 kg/m2), and body fat percentage (16.1 ± 5.2 vs. 14.9 ± 4.6%). The T1D group had 11.3 ± 5.1 years of diabetes duration and a suboptimal mean glycated haemoglobin level of 7.2 ± 1.1%. The subjects underwent a graded running treadmill test until exhaustion. Lactate concentration was assessed in arterialized blood at baseline and 3 and 20 min after the test. Cortisol, testosterone, tumour necrosis factor α, myoglobin, lactate dehydrogenase, zonulin, and vitamin D levels were evaluated in cubital fossa vein blood before and 60 min after the test.

RESULTS

T1D patients presented higher baseline zonulin, myoglobin concentration, testosterone/cortisol ratio, and lower maximal oxygen uptake. On adjusting for the baseline values, the groups differed in zonulin, lactate dehydrogenase, and myoglobin levels, testosterone/cortisol ratio, and lactate concentration determined 20 min after exercise (P < 0.05).

CONCLUSION

Maximum-intensity exercise increased muscle and intestinal damage in T1D participants. In patients with lower physical activity, very-high-intensity exercise should be recommended with caution. Observing the anabolic-catabolic index may help individualize effort intensity in T1D individuals.

Steric Blockade of Oxy-Myoglobin Oxidation by Thiosemicarbazones: Structure-Activity Relationships of the Novel PPP4pT Series

The di-2-pyridylketone thiosemicarbazones demonstrated marked anticancer efficacy, prompting progression of DpC to clinical trials. However, DpC induced deleterious oxy-myoglobin oxidation, stifling development. To address this, novel substituted phenyl thiosemicarbazone (PPP4pT) analogues and their Fe(III), Cu(II), and Zn(II) complexes were prepared. The PPP4pT analogues demonstrated potent antiproliferative activity (IC50: 0.009-0.066 μM), with the 1:1 Cu:L complexes showing the greatest efficacy. Substitutions leading to decreased redox potential of the PPP4pT:Cu(II) complexes were associated with higher antiproliferative activity, while increasing potential correlated with increased redox activity. Surprisingly, there was no correlation between redox activity and antiproliferative efficacy. The PPP4pT:Fe(III) complexes attenuated oxy-myoglobin oxidation significantly more than the clinically trialed thiosemicarbazones, Triapine, COTI-2, and DpC, or earlier thiosemicarbazone series. Incorporation of phenyl- and styryl-substituents led to steric blockade, preventing approach of the PPP4pT:Fe(III) complexes to the heme plane and its oxidation. The 1:1 Cu(II):PPP4pT complexes were inert to transmetalation and did not induce oxy-myoglobin oxidation.

Rapid and Effective Elimination of Myoglobin with CytoSorb® Hemoadsorber in Patients with Severe Rhabdomyolysis

INTRODUCTION

Rhabdomyolysis is characterized by destruction of muscle fibers by various causes and is diagnosed by increased creatine kinase concentrations in the blood. Myoglobin released into the blood may cause acute kidney injury. In this randomized controlled study, we hypothesized that myoglobin elimination would be faster when a hemoadsorber was added to a continuous veno-venous hemodialysis (CVVHD).

METHODS

Four patients in the control group received CVVHD with a high cut-off hemofilter using high blood and dialysate flows for 48 h. Four patients in the CytoSorb group received the same treatment, but in addition, the hemoadsorber CytoSorb® was inserted in front of the hemofilter and replaced once after 24 h. Blood samples were drawn simultaneously before (pre) and after (post) the hemofilter or else the hemoadsorber, after 5 and 30 min, as well as after 2, 4, 8, and 24 h. All measurements were repeated the next day after the hemoadsorber had been renewed in the CytoSorb group. Primary outcome was the area under the curve (AUC) of the relative myoglobin concentrations as percent of baseline. To evaluate the efficacy of myoglobin removal, relative reductions in myoglobin concentrations during one passage through each device at each time point were calculated.

RESULTS

Patients in the CytoSorb group had a significantly lower AUC during the first 24 h (42 ± 10% vs. 63 ± 6%, p = 0.029) as well as during the observation period of 48 h (26 ± 7% vs. 51 ± 12%, p = 0.029). The relative reductions for myoglobin were considerably higher in the CytoSorb group compared to the control group during the first 8 h.

CONCLUSION

Myoglobin concentrations declined considerably faster when CytoSorb was added to a CVVHD. When compared to a high-cut-off hemofilter, efficacy of CytoSorb in myoglobin elimination was much better. Because of saturation after 8-12 h an exchange may be necessary.

Investigating preoperative myoglobin level as predictive factor for acute kidney injury following cardiac surgery with cardiopulmonary bypass: a retrospective observational study

BACKGROUND

Early identification of patients at risk of AKI after cardiac surgery is of critical importance for optimizing perioperative management and improving outcomes. This study aimed to identify the association between preoperative myoglobin levels and postoperative acute kidney injury (AKI) in patients undergoing valve surgery or coronary artery bypass graft surgery (CABG) with cardiopulmonary bypass.

METHODS

This retrospective study included 293 patients aged over 17 years who underwent valve surgery or CABG with cardiopulmonary bypass. We excluded 87 patients as they met the exclusion criteria. Therefore, 206 patients were included in the final analysis. The patients... demographics as well as intraoperative and postoperative data were collected from electronic medical records. AKI was defined according to the Acute Kidney Injury Network classification system.

RESULTS

Of the 206 patients included in this study, 77 developed AKI. The patients who developed AKI were older, had a history of hypertension, underwent valve surgery with concomitant CABG, had lower preoperative hemoglobin levels, and experienced prolonged extracorporeal circulation (ECC) times. Multivariate logistic regression analysis revealed that preoperative myoglobin levels and ECC time were correlated with the development of AKI. A higher preoperative myoglobin level was an independent risk factor for the development of cardiac surgery-associated AKI.

CONCLUSIONS

Higher preoperative myoglobin levels may enable physicians to identify patients at risk of developing AKI and optimize management accordingly.

Study on the Expression Significance of Mb, BChE and cTnI in Myocardial Infarction and Their Relationship with Prognosis

Objective

Circulating biomarkers can be used as effective prediction tools for AMI diagnosis and prognosis, but their prediction efficiency is limited and still needs to be explored. The study aimed to investigate the changes of myocardial troponin I (cTn I), myoglobin (Mb), and butyryl cholinesterase (BChE) levels in patients with acute myocardial infarction (AMI) and its clinical predictive efficacy.

Methods

In this prospective cohort study, fifty patients with AMI who received PCI (AMI group) and 50 healthy subjects who underwent physical examination (reference group) during the same period were included. According to the occurrence of short-term major adverse cardiovascular events (MACE) during 6-month follow-up, they were divided into MACE group and non-MACE group . The difference of Mb, BChE, and cTnI levels was compared, and the ROC curve was drawn to analyze the prediction efficiency.

Results

Compared with the reference group or non-MACE group, Mb and cTnI significantly increased and BChE significantly decreased inAMI group and MACE group, respectively (P < .05). The AUC of Mb, cTnI and BChE in diagnosing AMI occurrence and prognosis were all > 0.75, and the sensitivity and specificity were all > 85.00%. cTnI, Mb and BChE have good diagnostic efficacy in disease occurrence and prognosis evaluation of AMI patients.

Conclusions

High expression of Mb and cTnI and low expression of BChE can increase the risk of AMI incidence and MACE occurrence and have high diagnostic efficacy, which can be used as sensitive factors in clinical AMI diagnosis and evaluation. Thess provided a theoretical foundation for AMI diagnosis and MACE preventing in AMI patients.

Myoglobin-loaded gadolinium nanotexaphyrins for oxygen synergy and imaging-guided radiosensitization therapy

Gadolinium (Gd3+)-coordinated texaphyrin (Gd-Tex) is a promising radiosensitizer that entered clinical trials, but temporarily fails largely due to insufficient radiosensitization efficacy. Little attention has been given to using nanovesicles to improve its efficacy. Herein, Gd-Tex is transformed into building blocks "Gd-Tex-lipids" to self-assemble nanovesicles called Gd-nanotexaphyrins (Gd-NTs), realizing high density packing of Gd-Tex in a single nanovesicle and achieving high Gd-Tex accumulation in tumors. To elucidate the impact of O2 concentration on Gd-Tex radiosensitization, myoglobin (Mb) is loaded into Gd-NTs (Mb@Gd-NTs), resulting in efficient relief of tumor hypoxia and significant enhancement of Gd-Tex radiosensitization, eventually inducing the obvious long-term antitumor immune memory to inhibit tumor recurrence. In addition to Gd3+, the versatile Mb@Gd-NTs can also chelate 177Lu3+ (Mb@177Lu/Gd-NTs), enabling SPECT/MRI dual-modality imaging for accurately monitoring drug delivery in real-time. This "one-for-all" nanoplatform with the capability of chelating various trivalent metal ions exhibits broad clinical application prospects in imaging-guided radiosensitization therapy.

Efficacy of On-line Hemodiafiltration for Rhabdomyolysis Presenting with Acute Kidney Injury Due to Unexpected Drug Abuse

Myoglobin is a well-known cause of acute kidney injury (AKI) due to rhabdomyolysis. However, whether or not removing serum myoglobin by on-line hemodiafiltration (OHDF) improves the kidney function remains unclear. We herein report a patient with a history of methamphetamine abuse who developed AKI due to rhabdomyolysis. A urinalysis and blood collection results obtained before and after OHDF demonstrated that OHDF improved the kidney function by removing a large amount of serum myoglobin rather than via urinary excretion. In conclusion, OHDF may prevent AKI progression effectively when the urine volume is insufficient.

Tissue Perfusion and Diffusion and Cellular Respiration: Transport and Utilization of Oxygen

This article provides an overview of the journey of inspired oxygen after its uptake across the alveolar-capillary interface, and the interplay among tissue perfusion, diffusion, and cellular respiration in the transport and utilization of oxygen. The critical interactions between oxygen and its facilitative carriers (hemoglobin in red blood cells and myoglobin in muscle cells), and with other respiratory and vasoactive molecules (carbon dioxide, nitric oxide, and carbon monoxide), are emphasized to illustrate how this versatile system dynamically optimizes regional convective transport and diffusive gas exchange. The rates of reciprocal gas exchange in the lung and the periphery must be well-matched and sufficient for meeting the range of energy demands from rest to maximal stress but not excessive as to become toxic. The mobile red blood cells play a vital role in matching tissue perfusion and gas exchange by dynamically regulating the controlled uptake of oxygen and communicating regional metabolic signals across different organs. Intracellular oxygen diffusion and facilitation via myoglobin into the mitochondria, and utilization via electron transport chain and oxidative phosphorylation, are summarized. Physiological and pathophysiological adaptations are briefly described. Dysfunction of any component across this integrated system affects all other components and elicits corresponding structural and functional adaptation aimed at matching the capacities across the entire system and restoring equilibrium under normal and pathological conditions.

Low-frequency alternating magnetic field thawing of frozen pork meat: Effects of intensity on quality properties and microstructure of meat and structure of myofibrillar proteins

The purpose of the study was to evaluate the changes in quality properties and microstructure of pork meat as well as structural variation in myofibrillar proteins (MPs) after low-frequency alternating magnetic field thawing (LF-MFT) with different intensities (1-5 mT). LF-MFT at 3-5 mT shortened the thawing time. LF-MFT treatment significantly influenced the quality properties of meat and notably improved the structure of MPs (P < 0.05), compared to atmosphere thawing (AT). Especially, among the thawing treatments, LF-MFT-4 (LF-MFT at 4 mT) had the lowest values of thawing loss and drip loss, and the least changes in the color and myoglobin content. Regarding the results of rheological properties and micrographs, an optimal gel structure and a more compact muscle fiber arrangement formed during LF-MFT-4. Moreover, LF-MFT-4 was beneficial for improving the conformation of MPs. Therefore, LF-MFT-4 reduced the deterioration of porcine quality by protecting MPs structure, indicating a potential use in the meat thawing industry.

A Lethal Combination: Legionnaires' Disease Complicated by Rhabdomyolysis, Acute Kidney Injury, and Non-Occlusive Mesenteric Ischemia

BACKGROUND Legionnaires' disease is one of the most common types of community-acquired pneumonia. It can cause acute kidney injury and also occasionally become severe enough to require continuous renal replacement therapy (CRRT). Non-occlusive mesenteric ischemia (NOMI) is a condition characterized by ischemia and necrosis of the intestinal tract without organic obstruction of the mesenteric vessels and is known to have a high mortality rate. CASE REPORT A 72-year-old man with fatigue and dyspnea was diagnosed with Legionnaires' disease after a positive result in the Legionella urinary antigen test pneumonia confirmed by chest radiography and computed tomography. He developed acute kidney injury, with anuria, rhabdomyolysis, septic shock, respiratory failure, and metabolic acidosis. We initiated treatment with antibiotics, catecholamines, mechanical ventilation, CRRT, steroid therapy, and endotoxin absorption therapy in the Intensive Care Unit. Despite ongoing CRRT, metabolic acidosis did not improve. The patient was unresponsive to treatment and died 5 days after admission. The autopsy revealed myoglobin nephropathy, multiple organ failure, and NOMI. CONCLUSIONS We report a fatal case of Legionnaires' disease complicated by rhabdomyolysis, acute kidney injury, myoglobin cast nephropathy, and NOMI. Legionella pneumonia complicated by acute kidney injury is associated with a high mortality rate. In the present case, this may have been further exacerbated by the complication of NOMI. In our clinical practice, CRRT is a treatment option for septic shock complicated by acute kidney injury. Thus, it is crucial to suspect the presence of NOMI when persistent metabolic acidosis is observed, despite continuous CRRT treatment.

The effect of cytosorb® application on kidney recovery in critically ill patients with severe rhabdomyolysis: a propensity score matching analysis

Severe rhabdomyolysis frequently results in acute kidney injury (AKI) due to myoglobin accumulation with the need of kidney replacement therapy (KRT). The present study investigated whether the application of Cytosorb® (CS) led to an increased rate of kidney recovery in patients with KRT due to severe rhabdomyolysis. Adult patients with a myoglobin-concentration >10,000 ng/ml and KRT were included from 2014 to 2021. Exclusion criteria were chronic kidney disease and CS-treatment before study inclusion. Groups 1 and 2 were defined as KRT with and without CS, respectively. The primary outcome parameter was independence from KRT after 30 days. Propensity score (PS) matching was performed (predictors: myoglobin, SAPS-II, and age), and the chi2-test was used. 35 pairings could be matched (mean age: 57 vs. 56 years; mean myoglobin: 27,218 vs. 26,872 ng/ml; mean SAPS-II: 77 vs. 76). The probability of kidney recovery was significantly (p = .04) higher in group 1 (31.4 vs. 11.4%, mean difference: 20.0%, odds ratio (OR): 3.6). Considering patients who survived 30 days, kidney recovery was also significantly (p = .03) higher in patients treated with CS (61.1 vs. 23.5%, mean difference: 37.6%, OR: 5.1). In conclusion, the use of CS might positively affect renal recovery in patients with severe rhabdomyolysis. A prospective randomized controlled trial is needed to confirm this hypothesis.

Clinical analysis of 908 patients with aortic dissection under different Stanford types: A cross-sectional study

This study aims to investigate the difference of clinical characteristics and risk factors in aortic dissection (AD) of patients with 2 Stanford subtypes. A retrospective analysis was conducted on 908 patients admitted to Tongji Hospital from July 2019 to January 2021, and the aortic computed tomography angiography was used to clearly diagnose the artery dissection. Patient basic information as well as blood test indicators containing leukocytes, neutrophils, lymphocytes, hemoglobin, myoglobin, hypersensitive cardiac troponin, γ-glutamyl transferase, total cholesterol, triglyceride, high density lipoprotein, low density lipoprotein, ultrasensitive C-reactive protein, glucose were recorded and analyzed. There was no significant difference in gender, heart rate, smoking history, hypertension history and diabetes history between the 2 groups (P > .05), however, compared with type A patients, type B patients were older, and had a significantly higher frequency of alcohol consumption (P < .05); On laboratory tests, type A patients had significantly higher mean leukocytes and neutrophils (P < .05), and significantly lower frequency of reduced hemoglobin than type B patients (P < .05), although there was no statistical difference in lymphocyte, γ-glutamyl transferase, total cholesterol, triglyceride, high density lipoprotein, low density lipoprotein and glucose counts between the 2 groups. Additionally, type A patients had a significantly higher number of abnormal myoglobin, hypersensitive cardiac troponin and ultrasensitive C-reactive protein test results than type B patients (P < .05). The receiver operating characteristic curve analysis showed that the area under the curve for each parameter was 0.605 (0.538-0.673) for hemoglobin, 0.610 (0.543-0.677) for leukocytes and 0.627 (0.561-0.693) for neutrophils. Understanding the relevant clinical indicators and risk factors of patients with different types of AD can provide a new perspective to assist the classification and diagnosis of AD and a basis for effective and rational treatment.

Myoglobin in Brown Adipose Tissue: A Multifaceted Player in Thermogenesis

Brown adipose tissue (BAT) plays an important role in energy homeostasis by generating heat from chemical energy via uncoupled oxidative phosphorylation. Besides its high mitochondrial content and its exclusive expression of the uncoupling protein 1, another key feature of BAT is the high expression of myoglobin (MB), a heme-containing protein that typically binds oxygen, thereby facilitating the diffusion of the gas from cell membranes to mitochondria of muscle cells. In addition, MB also modulates nitric oxide (NO•) pools and can bind C16 and C18 fatty acids, which indicates a role in lipid metabolism. Recent studies in humans and mice implicated MB present in BAT in the regulation of lipid droplet morphology and fatty acid shuttling and composition, as well as mitochondrial oxidative metabolism. These functions suggest that MB plays an essential role in BAT energy metabolism and thermogenesis. In this review, we will discuss in detail the possible physiological roles played by MB in BAT thermogenesis along with the potential underlying molecular mechanisms and focus on the question of how BAT-MB expression is regulated and, in turn, how this globin regulates mitochondrial, lipid, and NO• metabolism. Finally, we present potential MB-mediated approaches to augment energy metabolism, which ultimately could help tackle different metabolic disorders.

A primary multiple pleomorphic rhabdomyosarcoma of the heart in an adult dog

BACKGROUND

Heart tumors are rare in dogs. They can be benign or malignant. Clinical signs depend primarily on the location of the tumor and its effect on blood flow.

CASE PRESENTATION

An eleven-year-old crossbreed male dog lethargic and anorectic for previous 3 days was presented to the veterinary clinic. The focused ultrasound assessment with sonograms in trauma (FAST) revealed multiple tumors in the heart which were then confirmed in echocardiographic examination performed by a veterinary cardiologist. Due to the poor general condition and grave prognosis, the dog was humanely euthanized. The autopsy revealed numerous intracardiac tumors in all four heart chambers. No proliferative changes were found in other organs either in thoracic or abdominal cavity. Immunohistochemical examination was performed using formalin-fixed, paraffin-embedded tissue from heart masses. The antibodies against myoglobin, desmin, smooth muscle actin, vimentin, CD34, S100, and pan-cytokeratin (AE1/AE3) were used. Microscopically, the tumor was composed of fascicles of spindle-shaped cells with pale eosinophilic cytoplasm with round, oval, and focally elongated nuclei and one or two prominent nucleoli. The tumor cells showed strong diffuse cytoplasmic immunopositivity for myoglobin and vimentin and focal staining for desmin. Immunostainings for smooth muscle actin-SMA, CD34, pan-cytokeratin, S-100 protein were negative. The immunohistochemical staining pattern confirmed rhabdomyosarcoma.

CONCLUSIONS

This is the first description of the primary multiple heart rhabdomyosarcoma in a dog.

[Establishment and validation of a risk prediction model for disseminated intravascular coagulation patients with electrical burns]

Objective: To establish and validate a risk prediction model of disseminated intravascular coagulation (DIC) by the screening independent risk factors for the occurrence of DIC in patients with electrical burns. Methods: The retrospective case series study was conducted. The clinical data of 218 electrical burn patients admitted to Baogang Hospital of Inner Mongolia from January 2015 to January 2023 who met the inclusion criteria were collected, including 198 males and 20 females, with the age of (38±14) years. The patients were divided into DIC group and non DIC group based on whether they were diagnosed with DIC during the treatment period. The following data of patients of two groups were collected and compared, including age, gender, total burn area, full-thickness burn area, injury voltage, whether osteofascial compartment syndrome occurred within 1 day after injury, duration of stay in burn intensive care unit, total length of hospital stay, whether combined with inhalation injury and multiple injuries, whether shock occurred upon admission, the abbreviated burn severity index score, and the acute physiology and chronic health evaluation Ⅱ score. The laboratory examination data of the patients within 24 hours after admission were also collected, including blood routine indexes: white blood cell count (WBC), hemoglobin level, platelet count (PLT), and neutrophil count; coagulation indexes: activated partial thromboplastin time (APTT), prothrombin time, thrombin time, and levels of D-dimer and fibrinogen (FIB); blood biochemistry indexes: aspartic transaminase, alanine transaminase, direct bilirubin, total bilirubin, total protein, albumin, blood glucose, creatinine, and urea nitrogen; blood gas analysis indexes: blood pH value, arterial partial pressure of oxygen, arterial partial pressure of carbon dioxide, bicarbonate, and base excess; and cardiac zymogram indexes: levels of myoglobin, troponin, lactate dehydrogenase, creatine kinase (CK), and α-hydroxybutyrate dehydrogenase. Data were statistically analyzed with chi-square test, Fisher's exact probability test, independent sample t test, and Mann-Whitney U test. For the variables with statistically significant differences in single factor analysis, the least absolute value selection and shrinkage operator (LASSO) regression was used to reduce the dimension, and the predictive factors for DIC in 218 patients with electrical burns were screened. The above-mentioned predictors were included in multivariate logistic regression analysis to find out the independent risk factors for DIC in 218 patients with electrical burns, and to draw the prediction model nomograms. The performance of the prediction model was evaluated by the receiver operating characteristic (ROC) curve and the area under the ROC curve, and the prediction model was validated by the calibration curve and clinical decision curve analysis (DCA). Results: Compared with those in non DIC group, the total burn area, full-thickness burn area, total length of hospital stay, and the proportions of high voltage caused injury, occurrence of osteofascial compartment syndrome within 1 day after injury, combination of inhalation injury, and occurrence of shock upon admission of patients in DIC group were significantly increased/prolonged (with Z values of -2.53, -4.65, and -2.10, respectively, with χ2 values of 11.46, 16.00, 7.98, and 18.93, respectively, P<0.05). Compared with those in non DIC group, the APTT, level of D-dimer, myoglobin, WBC, PLT, and levels of FIB, total bilirubin, and CK of patients within 24 hours after admission in DIC group were significantly prolonged/increased (with Z values of -2.02, -4.51, and -3.82, respectively, with t values of -3.84, -2.34, -2.77, -2.70, and -2.61, respectively), and the level of total protein and blood pH value were significantly reduced (t=-2.85, Z=-2.03), P<0.05. LASSO regression analysis was carried out for the above 17 indicators with statistically significant differences. The results showed that injury voltage, the occurrence of shock upon admission, the occurrence of osteofascial compartment syndrome within 1 day after injury, and levels of D-dimer and total protein within 24 hours after admission were predictive factors for the occurrence of DIC in 218 patients with electrical burns (with regression coefficients of 0.24, 0.52, 0.35, 0.13, and -0.001, respectively). Multivariate logistic regression analysis showed that injury voltage, the occurrence of shock upon admission, the occurrence of osteofascial compartment syndrome within 1 day after injury, and D-dimer level within 24 hours after admission were independent risk factors for DIC in 218 patients with electrical burns (with odds ratios of 3.33, 4.24, 2.68, and 1.38, respectively, with 95% confidence intervals of 1.43-7.79, 1.78-10.07, 1.17-6.13, and 1.19-1.61, respectively, P<0.05). Based on the aforementioned four independent risk factors, the nomogram of prediction model for evaluating the probability of DIC in patients was drawn. The area under the ROC curve of prediction model was 0.88, and the 95% confidence interval was 0.82-0.95, indicating that the model had good predictive ability; the curve of prediction model tended to be near the ideal curve, indicating that the model had a high calibration degree; the clinical DCA of prediction model showed that the threshold probability of patients ranged from 4% to 97%, indicating that the model had good predictive ability. Conclusions: The injury voltage, the occurrence of shock upon admission, the occurrence of osteofascial compartment syndrome within 1 day after injury, and D-dimer level within 24 hours after admission are independent risk factors for the occurrence of DIC in patients with electrical burns. The prediction model established based on the above indicators can provide early warning for the occurrence of DIC in these patients.

Temporal patterns of cytokine and injury biomarkers in hospitalized COVID-19 patients treated with methylprednisolone

Background

The novel coronavirus disease 2019 (COVID-19) presents with complex pathophysiological effects in various organ systems. Following the COVID-19, there are shifts in biomarker and cytokine equilibrium associated with altered physiological processes arising from viral damage or aggressive immunological response. We hypothesized that high daily dose methylprednisolone improved the injury biomarkers and serum cytokine profiles in COVID-19 patients.

Methods

Injury biomarker and cytokine analysis was performed on 50 SARS-Cov-2 negative controls and 101 hospitalized severe COVID-19 patients: 49 methylprednisolone-treated (MP group) and 52 placebo-treated serum samples. Samples from the treated groups collected on days D1 (pre-treatment) all the groups, D7 (2 days after ending therapy) and D14 were analyzed. Luminex assay quantified the biomarkers HMGB1, FABP3, myoglobin, troponin I and NTproBNP. Immune mediators (CXCL8, CCL2, CXCL9, CXCL10, TNF, IFN-γ, IL-17A, IL-12p70, IL-10, IL-6, IL-4, IL-2, and IL-1β) were quantified using cytometric bead array.

Results

At pretreatment, the two treatment groups were comparable demographically. At pre-treatment (D1), injury biomarkers (HMGB1, TnI, myoglobin and FABP3) were distinctly elevated. At D7, HMGB1 was significantly higher in the MP group (p=0.0448) compared to the placebo group, while HMGB1 in the placebo group diminished significantly by D14 (p=0.0115). Compared to healthy control samples, several immune mediators (IL-17A, IL-6, IL-10, MIG, MCP-1, and IP-10) were considerably elevated at baseline (all p≤0.05). At D7, MIG and IP-10 of the MP-group were significantly lower than in the placebo-group (p=0.0431, p=0.0069, respectively). Longitudinally, IL-2 (MP-group) and IL-17A (placebo-group) had increased significantly by D14. In placebo group, IL-2 and IL-17A continuously increased, as IL-12p70, IL-10 and IP-10 steadily decreased during follow-up. The MP treated group had IL-2, IFN-γ, IL-17A and IL-12p70 progressively increase while IL-1β and IL-10 gradually decreased towards D14. Moderate to strong positive correlations between chemokines and cytokines were observed on D7 and D14.

Conclusion

These findings suggest MP treatment could ameliorate levels of myoglobin and FABP3, but appeared to have no impact on HMGB1, TnI and NTproBNP. In addition, methylprednisolone relieves the COVID-19 induced inflammatory response by diminishing MIG and IP-10 levels. Overall, corticosteroid (methylprednisolone) use in COVID-19 management influences the immunological molecule and injury biomarker profile in COVID-19 patients.

Application of portable Vis-NIR spectroscopy for rapid detection of myoglobin in frozen pork

Myoglobin content is considered as a crucial index to evaluate the quality of frozen pork. In this study, a portable visible and near-infrared (Vis-NIR) spectrometer combined with chemometrics was used to detect myoglobin content in frozen pork. Metmyoglobin, deoxymyoglobin, oxymyoglobin, and total myoglobin were assessed spectrophotometrically. The raw Vis-NIR spectra of frozen pork samples were pre-processed using 1^st derivatives (FD). Afterward, Synergy Interval Partial Least Square (Si-PLS) coupled Competitive Adaptive Reweighted Sampling algorithm (Si-CARS-PLS) was applied to select characteristic variables. The Si-CARS-PLS models revealed the probability of estimating myoglobin content in frozen pork, with predictive correlation coefficients (R_p) for metmyoglobin, deoxymyoglobin, oxymyoglobin, and total myoglobin as 0.9095, 0.9004, 0.8578, and 0.9133, respectively. The findings of this study showed that Vis-NIR spectroscopy coupled with Si-CARS-PLS is a promising method and offered a way forward for determining the myoglobin content in frozen pork.

A Phase 1 study for safety and pharmacokinetics of BIO101 (20-hydroxyecdysone) in healthy young and older adults

BACKGROUND

Sarcopenia is an age-related skeletal muscle disorder characterized by loss of muscle mass and strength leading to mobility disability. 20-Hydroxyecdysone (20E) is a polyhydroxylated plant steroid that demonstrates pharmacological effects in many disease animal models including ageing/sarcopenia. BIO101 is a 20E purified investigational drug (≥97%) that previously demonstrated good toxicology profiles in rat and dog. BIO101 is evaluated in healthy young and older adults in a Phase 1 study.

METHODS

This study is a Single Ascending Dose (SAD) followed by a 14-day Multiple Ascending Dose (MAD). In SAD, BIO101 was administered orally to 16 young adults at doses from 100 to 1400 mg and to 8 older adults (age ≥65 years) at 1400 mg. In MAD, doses of 350 mg once daily (qd), 350 mg twice daily (bid) and 450 mg bid were administered to 10 older adults. The primary objective was to evaluate safety and pharmacokinetics (PK), including dosing of circulating metabolites. Pharmacodynamic effects were investigated with regard to myostatin, procollagen-III-amino-terminal propeptide (PIIINP), myoglobin, creatine-kinase Muscle Brain (CKMB), renin and aldosterone plasma/serum levels.

RESULTS

BIO101 showed a good safety profile with only mild to moderate adverse events and a satisfactory pharmacokinetic profile. In SAD, at 100 mg to 1400 mg, mean Cmax and areas under the curve increased less than dose-proportionally. Mean half-life was short (2.4-4.9 h), and mean renal clearance was comparable in all doses (4.05-5.05 L/h). Mean plasma exposure was slightly lower in older adults (22% lower for Cmax and 13%-15% lower for AUCs) compared with young subjects. In MAD, 350 and 450 mg bid led to a slight accumulation over 14 days (mean ratio of accumulation [Rac] of 1.31 in both cohorts). Reduction of biomarkers (myoglobin, CK-MB) mean serum levels (vs. baseline) was observed at 450 mg bid. Two major metabolites of 20E (14-deoxy-20-hydroxyecdysone and 14-deoxypoststerone) were identified and quantified.

CONCLUSIONS

BIO101 shows a good safety and pharmacokinetic profile that led to the selection of doses for the subsequent interventional clinical trials of Phase 2 in age-related sarcopenia (SARA-INT) and Phase 3 in Covid-19 (COVA).

Engineering an Oxygen-Binding Protein for Photocatalytic CO2 Reductions in Water

While native CO2 -reducing enzymes display remarkable catalytic efficiency and product selectivity, few artificial biocatalysts have been engineered to allow understanding how the native enzymes work. To address this issue, we report cobalt porphyrin substituted myoglobin (CoMb) as a homogeneous catalyst for photo-driven CO2 to CO conversion in water. The activity and product selectivity were optimized by varying pH and concentrations of the enzyme and the photosensitizer. Up to 2000 TON(CO) was attained at low enzyme concentrations with low product selectivity (15 %), while a product selectivity of 74 % was reached by increasing the enzyme loading but with a compromised TON(CO). The efficiency of CO generation and overall TON(CO) were further improved by introducing positively charged residues (Lys or Arg) near the active stie of CoMb, which demonstrates the value of tuning the enzyme secondary coordination sphere to enhance the CO2 -reducing performance of a protein-based photocatalytic system.

Myoglobinemia, Peripheral Arterial Disease, and Patient Mortality

BACKGROUND

Peripheral arterial disease (PAD) causes leg muscle damage due to inadequate perfusion and increases cardiovascular events and mortality 2- to 3-fold. It is unclear if PAD is a biomarker for high-risk cardiovascular disease or if skeletal muscle injury harms arterial health. The objective of this work is to test if serum myoglobin levels (myoglobinemia) are a marker of PAD, and if so, whether myoglobin impairs vascular health.

STUDY DESIGN

Patient blood samples were collected from PAD and control (no PAD) patients and interrogated for myoglobin concentrations and nitric oxide bioavailability. Patient mortality over time was captured from the medical record. Myoglobin activity was tested on endothelial cells and arterial function.

RESULTS

Myoglobin is a biomarker for symptomatic PAD and was inversely related to nitric oxide bioavailability; 200 ng/mL myoglobin in vitro increased endothelial cell permeability in vitro and decreased nitrate bioavailability. Ex vivo, 100 ng/mL myoglobin increased vascular tone in naive murine aortas approximately 1.5 times, impairing absolute vessel relaxation. In vivo, we demonstrated that myoglobinemia caused impaired flow-mediated dilation in a porcine model. Patients presenting with myoglobin levels of 100 ng/mL or greater had significantly more deaths than those with myoglobin levels of less than 100 ng/mL.

CONCLUSIONS

Using a combination of patient data, in vitro, ex vivo, and in vivo testing, we found that myoglobin is a biomarker for symptomatic PAD and a potent regulator of arterial health that can increase vascular tone, increase vascular permeability, and cause endothelial dysfunction, all of which may contribute to the vulnerability of PAD patients to cardiovascular events and death.

Characteristics of cardiac involvement in immune-mediated necrotizing myopathy

Objective

To investigate the characteristics of cardiac involvement due to Immune-mediated Necrotizing Myopathy (IMNM).

Methods

Patients diagnosed with Immune-mediated Necrotizing Myopathy (IMNM) who attended the Department of Neurology and the Department of Rheumatology and Immunology at the First Medical Center of the PLA General Hospital between February 2011 and June 2022 were collected. Clinicopathological diagnosis of IMNM was performed according to the criteria established by the European Neuromuscular Center (ENMC). All patients underwent muscle biopsy and Myositis-specific antibodies (MSAs) testing. Information included age, gender, disease duration, intramuscular and extramuscular manifestations, laboratory findings (including creatine kinase, lactate dehydrogenase levels, troponin T, myoglobin and atrial natriuretic peptide), electromyography, skeletal muscle pathology and immunohistochemical staining.

Results

A total of 57 patients were included in this study. Of the serological tests, 56.1% (32/57) were positive for SRP, 21.1% (12/57) were positive for HMGCR and 22.8% (13/57) were seronegative. Thirty patients (52.6%, 30/57) presented with varying degrees of cardiac involvement. We performed ECG in 23 patients and found 6 patients with arrhythmia (26.1%), 12 patients with myocardial ischemia (52.2%), and 7 patients with acute coronary syndrome (ST elevation and non-ST elevation myocardial infarction) (30.4%), and 4 patients with left axis deviation or left ventricular high voltage, suggesting left ventricular hypertrophy (17.4%). Cardiac ultrasound was performed in 14 patients and 3 showed pericardial effusion (21.4%); Decreased left ventricular ejection fraction and atrial enlargement were 2 each; 8 showed a decrease in left ventricular diastolic function (57.1%). In addition, one patient had myocardial edema.

Conclusion

Cardiac involvement is not uncommon in IMNM. However, besides clearly statistically significant differences in the disease course, and in the values of troponin T and myoglobin, our data did not show any statistically significant difference in other features of cardiac involvement between patients with different subtypes of IMNM.

Acute Responses to High-Intensity Back Squats with Bilateral Blood Flow Restriction

This study examined the acute effects of high-intensity resistance exercise with blood flow restriction (BFR) on performance and fatigue, metabolic stress, and markers of inflammation (interleukin-6 (IL-6)), muscle damage (myoglobin), angiogenesis (vascular endothelial growth factor (VEGF)). Thirteen resistance-trained participants (four female, 24.8 ± 4.7 years) performed four sets of barbell back-squats (75% 1RM) to failure under two conditions: blood flow restriction (BFR, bilateral 80% occlusion pressure) and control (CTRL). Completed repetitions and pre-post-exercise changes in maximal voluntary isometric contractions, countermovement jump, barbell mean propulsive velocity, and surface electromyography were recorded. Pre-post blood lactate (BLa) and venous blood samples for analysis of IL-6, myoglobin, and VEGF were collected. Ratings of perceived exertion (RPE) and pain were recorded for each set. Fewer repetitions were performed during BFR (25.5 ± 9.6 reps) compared to CTRL (43.4 ± 14.2 reps, p < 0.001), with greater repetitions performed during sets 1, 2, and 4 (p < 0.05) in CTRL. Although RPE between conditions was similar across all sets (p > 0.05), pain was greater in BFR across all sets (p < 0.05). Post-exercise fatigue was comparable between conditions. BLa was significantly greater in CTRL compared to BFR at two minutes (p = 0.001) but not four minutes post-exercise (p = 0.063). IL-6 was significantly elevated following BFR (p = 0.011). Comparable increases in myoglobin (p > 0.05) and no changes in VEGF were observed (p > 0.05). BFR increases the rate of muscular fatigue during high-intensity resistance exercise and acutely enhances IL-6 response, with significantly less total work performed, but increases pain perception, limiting implementation.

Comparison of Top-Down Protein Fragmentation Induced by 213 and 193 nm UVPD

The growing interest in advancing tandem mass spectrometry strategies for top-down proteomics has motivated efforts to optimize ion activation strategies for intact proteins, including the comparison of 193 and 213 nm wavelengths for ultraviolet photodissociation (UVPD). The present study focuses on the performance and outcomes of UVPD for five proteins, ubiquitin, cytochrome C, frataxin, myoglobin, and carbonic anhydrase, with an emphasis on evaluating the similarities and differences in fragmentation promoted by UVPD using 193 nm versus 213 nm photons. Mass spectra were collected as a function of the number of laser pulses, and precursor depletion levels were monitored and controlled to provide consistent energy deposition between 213 and 193 nm UVPD. Fragment ions were confirmed on the basis of their isotopic distributions in m/z space to preserve both charge state and abundance information and were classified on the basis of ion type and frequency. A large portion of the total fragment ion abundance was attributable to preferential cleavages, particularly ones adjacent to proline residues. These cleavages were examined on the basis of the backbone site and abundances, revealing that a and y-2 ions N-terminal to proline residues appeared at disproportionately high abundances in 213 nm UVPD spectra as compared to 193 nm UVPD spectra, highlighting one notable difference in the top-down spectra. We theorize that these fragments are formed more efficiently in 213 nm UVPD than in 193 nm UVPD due to increased absorption of 213 nm photons at the proline amide bond.

Myoglobin cast nephropathy following multiple bee stings

Bee stings usually result in mild allergic reactions; however, mass envenomation can cause severe complications such as rhabdomyolysis, hemolysis, shock, or multi-organ damage. Rhabdomyolysis can result in acute renal failure either by tubular obstruction by myoglobin casts or by direct cytotoxic injury. We present a case of a 12-year-old female child who presented with sudden onset anuria and hypertension following mass envenomation by bees. A renal biopsy was performed, the microscopic evaluation of which revealed tubular injury, with associated intratubular pigmented casts. The casts stained positive for myoglobin immunohistochemical stain, thus confirming a diagnosis of myoglobin cast nephropathy. The patient was given IV steroids and underwent seven sessions of hemodialysis, following which there was complete recovery of renal function.

Application of simultaneous ultrasonic curing on pork (Longissimus dorsi): Mass transport of NaCl, physical characteristics, and microstructure

This study aimed to investigate the effect of ultrasound curing with various working modes and frequency combinations, including mono-, dual- and tri-frequency, on the content of NaCl and tenderness of pork loins (Longissimus dorsi). The physical qualities, myoglobin, moisture migration, distribution, and microstructure of pork were also evaluated. The results displayed that the NaCl content of samples cured by simultaneous ultrasound (100 W/L) working mode with a frequency combination of 20, 40, and 60 kHz was higher than that of other ultrasound working modes. The effect of ultrasonic brining was significantly better than the static curing when the saline solution was >35 mL. In addition, the samples cured by simultaneous ultrasound had better physical qualities, including more pickling absorptivity, less cooking loss, and lower hardness, tenderness, and chewiness value. The intensity of lightness was reduced, although redness and yellowness remained unaltered compared to static curing. The myoglobin content decreased drastically without changing the oxygenation level, and the relaxation time of T_2b and T₂₁ was delayed. The microstructure indicated that the ultrasonic treatment could promote changes in meat texture. Overall, the simultaneous ultrasound at various frequencies could efficiently accelerate NaCl penetration and improve pork quality.

Acute kidney injury due to myoglobin cast nephropathy in the setting of coronavirus disease 2019-mediated rhabdomyolysis: a case report

BACKGROUND

We present this case of coronavirus disease 2019-associated acute kidney injury with rhabdomyolysis-with noteworthy renal biopsy findings demonstrating myoglobin cast nephropathy-to add to the limited literature on coronavirus disease 2019-related acute kidney injury and rhabdomyolysis.

CASE PRESENTATION

A 67-year-old Caucasian man presented to our hospital with 3 weeks of malaise and decreased oral intake and several days of abnormal taste, poor appetite, decrease urine output, gastrointestinal symptoms, and myalgias, and was ultimately diagnosed with coronavirus disease 2019. His hospital course was complicated by acute kidney injury and, upon workup of his renal failure, was diagnosed with myoglobin cast nephropathy due to coronavirus disease 2019-mediated rhabdomyolysis. Ultimately, his renal function improved following hydration back to his baseline 6 weeks after his initial diagnosis of coronavirus disease 2019.

CONCLUSIONS

Given our limited knowledge of manifestations of coronavirus disease 2019, it is important to have a more in-depth understanding of the spectrum of disease of coronavirus disease 2019, which can affect various organ systems, including the kidney, and the manifestations of end-organ damage associated with it. We present this case to highlight a rarely reported finding of myoglobin cast nephropathy due to coronavirus disease 2019-mediated rhabdomyolysis.