Unusual presentation of cutaneous anthrax with acute kidney injury: A case report

BACKGROUNDː Distant metastases (DM) occur rarely and are associated with poor outcomes in patients with differentiated thyroid carcinoma (DTC). The aim of this study was to explore potential risk factors of DM in DTC and build a decision-tree model. METHODSː The medical records of 15,591 patients who were diagnosed with DTC after initial surgery in three medical centers (2000 to 2018) were reviewed and 37 patients (test group) and 14 patients (validation group) with DM and detailed clinicopathologic characteristics were identified. Patients with no evidence of disease (NED) postoperatively were randomly sampled to create a control group in a 4:1 ratio. RESULTSː Multiple factors, including median age, extrathyroidal extension (ETE), AJCC stage, position, histological type, and diameter differed significantly between the DM and NED groups (P˂0.001) in univariate and multivariate analysis. AJCC stage and diameter of the primary tumor made the greatest contributions to prognosis according to decision-tree analysis and a random forest algorithm. The predictive model constructed from these data achieved 100% accuracy of classification. External validation confirmed that this model has 100% accuracy of classification. In addition, histology and ETE were found to be independent predictors of survival in patients with metachronous metastases. CONCLUSIONSː This study optimized the weight of risk factors, including AJCC stage and diameter of primary tumor, in predicting DM in patients with DTC. Our predictive model provides a strong tool for prediction that may potentially affect clinical decision-making.

This paper introduces a new non-isolated double-input triple-output (DITO) high voltage gain DC-DC converter with a wide range of applications, including hybrid voltage source systems, solar home appliances, dc bus power distribution systems, and electrical vehicles (EV). The proposed DITO converter interfaces two hybrid voltage sources to supply three different output loads with varying voltage and power levels. Compared to conventional converters of the same type, the proposed DITO converter offers several advantages, including operation for all duty cycles, integration of hybrid energy sources to transfer power to multiple loads, high voltage conversion ratio for all three output ports, a higher ratio of total voltage gain to total components number, common grounded input and output DC ports, simultaneous DC voltage regulation of three output ports by tuning separate controlling parameters of duty cycles, an additional turn ratio of coupled inductors to increase the voltage gain of output ports, and medium voltage stress on switches. The proposed DITO converter utilizes a new single-switch single-coupled-inductor DC-DC structure, which is analyzed and verified through a prototype implementation for 25V and 30V input voltages and 210V, 330V, and 400V output voltages with a total power of 480W. The experimental results confirm the simulation results and theoretical analysis.

SARS-CoV-2 and Crimean-Congo hemorrhagic fever virus coinfection: A case report and review of the diagnostic challengesZeinab Mohseni Afshar1, Mohammad Barary2, Arefeh Babazadeh3, Soheil Ebrahimpour3, *Clinical Research Development Center, Imam Reza Hospital, Kermanshah University of Medical Sciences, Kermanshah, IranStudent Research Committee, Virtual School of Medical Education and Management, Shahid Beheshti University of Medical Sciences, Tehran, IranInfectious Diseases and Tropical Medicine Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, IranCorrespondence: Soheil Ebrahimpour, Infectious Diseases and Tropical Medicine Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran. Email: [email protected]

Pseudotumor cerebri due to brucellosis: A rare case reportEhsan Alimohammad1, Arefeh Babazadeh2, Soheil Ebrahimpour2, Ali Alizadeh Khatir3 Mohammad Barary4, Zeinab Mohseni Afshar5, *Department of Neurosurgery, Kermanshah University of Medical Science, Kermanshah, IranInfectious Diseases and Tropical Medicine Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, I.R. IranMobility Impairment Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, IranStudent Research Committee, Virtual School of Medical Education and Management, Shahid Beheshti University of Medical Sciences, Tehran, IranClinical Research Development Center, Imam Reza Hospital, Kermanshah University of Medical Sciences, Kermanshah, IranCorrespondence: Zeinab Mohseni Afshar, Clinical Research Development Center, Imam Reza Hospital, Kermanshah University of Medical Sciences, Kermanshah, Iran. Email: [email protected]

This paper aims to develop a robust decomposed system control (RDSC) strategy under input constraints for an electro-mechanical linear actuator (EMLA) with model uncertainty and external disturbances. At first, a state-space model of a complex multi-stage gearbox EMLA system, driven by a permanent magnet synchronous motor (PMSM), is developed, and the non-ideal characteristics of the ball screw are presented through the model. This results in a six-order nonlinear strict-feedback form (NSFF) system that is decomposed into three subsystems. As the paper’s main result, a novel RDSC strategy with uniform exponential stability for controlling subsystem states is presented. This developed controller avoids the “explosion of complexity” problem associated with backstepping by treating the time derivative of the virtual control input as an uncertain system term. The proposed method, while assuming load disturbances and input constraints with arbitrary bounds, offers a straightforward control approach for a broader range of applications. The controller’s performance is evaluated through the simulation of two distinct duty cycles, each representing different levels of demand on the actuator facing load disturbances near the rated motor performance.

Abstract Background: Persons with diabetes may have an elevated risk of Parkinson’s disease. Statin use could also modify the progression of Parkinson’s disease. Objective: The aim was to study whether there is an association between statin exposure and risk of Parkinson’s disease in persons with diabetes Methods: A nationwide nested case-control study of 2,017 Parkinson’s disease cases and their 7,934 matched controls with diabetes was performed using data from the Finnish Parkinson’s disease study (FINPARK). Persons with Parkinson’s disease were diagnosed between 1999–2015 and statin use (1995–2015) was determined from Prescription Register. In the main analysis exposure at least three years before outcome was considered. Cumulative exposure was categorized into tertiles, and associations were analyzed with conditional logistic regression. Results: Prevalence of statin use was similar in Parkinson’s disease cases and controls, with 54.2% of cases and 54.4% controls exposed before the lag time (adjusted odds ratio (aOR) = 1.02; 95% CI: 0.91–1.15). Those in the highest cumulative statin exposure tertile had higher risk of Parkinson’s disease than statin nonusers (aOR = 1.21; 95% CI: 1.04–1.42), or those in the lowest cumulative statin exposure tertile (aOR = 1.29; 95% CI: 1.07–1.57). Conclusions: Our nationwide study that controlled for diabetes duration and reverse causality does not provide support for the hypothesis that statin use decreases the risk of Parkinson’s disease.

The human brain is postulated to function as a prediction machine, constantly comparing incoming sensory input to predictions based on past experiences. When an event contradicts these predictions, it results in a prediction error (PE), which has been shown to enhance subsequent memory. However, the neural mechanisms underlying the influence of PE on subsequent memory remain unclear. This study investigated the electrophysiological correlates during encoding and retrieval of events eliciting PE. We employed a statistical learning task in which participants were presented with pairs of objects in sequence. Subsequently, while recording electroencephalography (EEG), we introduced PE by replacing the second object of each pair with new objects and we then tested the participants’ memory. Behaviorally, PE did not enhance memory. During retrieval, we observed higher amplitudes of the posterior recollection component for violation items that were remembered compared to those that were forgotten. In contrast, no evidence for the presence of the frontal negative familiarity component was found. These results suggest that recollection, but not familiarity, plays a crucial role in the interplay between PE and memory. Contrary to our hypothesis, we did not observe a relationship between PE and the P3 component during encoding. In conclusion, our study contributes to the growing body of knowledge concerning the intricate relationship between PE and episodic memory. It sheds light on the underlying neural mechanisms involved and emphasizes the importance of recollection in this context.

MALDI mass spectrometry imaging (MALDI imaging) is uniquely suited to advance cancer research by measuring spatial distribution of endogenous and exogenous molecules directly from thin tissue sections. These molecular maps provide valuable insights into various aspects of basic and translational cancer research, including spatial tumor and tumor microenvironment biology, pharmacological interventions, and patient stratification. However, despite these advantages, the utilization of MALDI imaging in studying rare cancers, which comprise approximately 20% of all cancers, remains limited. Rare cancers pose unique challenges in medical research, resulting in understudied entities with suboptimal management and outcomes. In this review, we explore the value of MALDI imaging in sarcoma, as an example of a highly heterogeneous and challenging rare cancer. We summarize existing MALDI imaging studies in sarcoma and outline potential future applications. In addition, we address the specific challenges encountered when employing MALDI imaging to rare cancers, and propose solutions, including the utilization of formalin-fixed paraffin-embedded tissues, multi-site studies, implementation of multiplexed experiments, and considerations for data sharing practices. Through this review, we aim to inspire collaboration between MALDI imaging researchers and clinical colleagues, to deploy the unique capabilities of MALDI imaging in rare cancer research, particularly in the context of sarcoma.

Thermal energy storage systems (TES) have emerged as a vital solution for addressing the gap between energy supply and demand. While research on solar energy storage has primarily focused on flat-plate collectors, limited work has been done to explore the potential of Scheffler solar concentrators. This study proposes an innovative approach to thermal energy storage using a Scheffler solar concentrator and phase change material (PCM) to address the energy needs of rural areas with limited access to electricity. Real-time design and testing were conducted using paraffin wax as the PCM, and CFD analysis was performed using the ANSYS Fluent software to determine the optimal charging and discharging times. The results indicated that the required charging time was 17 min according to the CFD analysis, while the experimental results yielded a charging time of 18 min. The results demonstrated that the proposed approach is a feasible and effective solution for meeting the energy demands of rural communities. The charging time was optimized using the response surface method, yielding an optimal charging time of 20.5 min and an optimal discharging time of 26.2 min. Overall, these findings highlight the potential of utilizing Scheffler solar concentrators and PCMs for sustainable and reliable thermal energy storage.

A document by Arjun Basnet. Click on the document to view its contents.

INTRODUCTIONThe PIEZO1 gene is located on chromosome 16 (16q24.3) and encodes the largest known human transmembrane protein, PIEZO1. The PIEZO1 protein has low tissue specificity, showing expression in at least 27 different tissue types.1 This mechanoreceptor is activated by mechanical force and controls potassium and calcium flow in multiple cell types, most prominently lung, bladder, skin, and red blood cells.1,2 Studies have shown that in fetal tissue the highest expression of this protein is in the liver, spleen, and lymphatic vessels.1,2 PIEZO1 channels are crucial during development of lymphatic vasculature, acting as baroreceptors in the lymphatic and vascular systems, and sensing frictional force to determine vascular structure.3 Pathogenic variants inPIEZO1 have therefore been phenotypically associated with lymphatic malformation, perinatal edema, and non-immune fetal hydrops, as well as hemolytic anemia and pseudohyperkalemia.2,4PIEZO1 -related disorders include autosomal recessive lymphatic malformation 6 (LMPHM6, OMIM 616843) due to biallelic loss-of-function variants and autosomal dominant dehydrated hereditary stomatocytosis (OMIM 194380) due to heterozygous gain-of-function variants.5 Despite significant phenotypic heterogeneity, both disorders may present with perinatal edema and non-immune hydrops fetalis.5Congenital lymphatic dysplasia is the hallmark feature of LMPHM6, resulting in severe impairment of vascular development, and commonly causing in utero demise. The associated primary lymphedema affects all body segments, causing pleural effusions, pulmonary and intestinal lymphangiectasia, facial and neck swelling, chylothoraces, and pericardial effusion. In some cases, hydrops fetalis has resolved postnatally with concomitant recurrence of peripheral edema during childhood, typically in the lower limbs. Most reported cases of LMPHM6 have resultant pleural effusions that become chylous with the introduction of enteral feeds.5More recently, PIEZO1 has been implicated as a potential mechanotransducer in osteoblastic bone formation. Osteoblasts respond to mechanical loading and bone growth and maintenance is known to be impaired in microgravity environments and non-weight bearing patients. However, the mechanism by which this occurs has previously been uncertain.6 Recent research found that knockout mice with PIEZO1-deficient osteoblasts sustain spontaneous fractures in the setting of impaired bone density and strength. Patients with osteoporosis have been found to have reduced expression of the PIEZO1 protein.6 Likewise, simulated microgravity environments result in decreased osteoblastic function via suppression of PIEZO1 activity.7 Here, we present a patient with LMPH6 due to likely pathogenic homozygous loss-of-function PIEZO1variants who has unexplained bone disease, the first reported case of significant bone disease in this phenotype.

Microbial cells must continually adapt their physiology in the face of changing environmental conditions. Archaea living in extreme conditions, such as saturated salinity, represent important examples of such resilience. The model salt-loving organism Haloferax volcanii exhibits remarkable plasticity in its morphology, biofilm formation, and motility in response to variations in nutrients and cell density. However, the mechanisms regulating these lifestyle transitions remain unclear. In prior research, we showed that the transcriptional regulator, TrmB, maintains the rod shape in the related species Halobacterium salinarum by activating the expression of enzyme-coding genes in the gluconeogenesis metabolic pathway. In Hbt. salinarum, TrmB-dependent production of glucose moieties is required for cell surface glycoprotein biogenesis. Here we use a combination of genetics, quantitative phenotyping, and gene expression assays to demonstrate that TrmB is essential for growth under gluconeogenic conditions in Hfx. volcanii. The ∆ trmB strain rapidly accumulated suppressor mutations in a gene encoding a novel transcriptional regulator, which we name Trm B su ppressor, or TbsP. TbsP is required for adhesion to abiotic surfaces (i.e. biofilm formation), and maintains wild type cell morphology, and motility. TrmB and TbsP jointly regulate the glucose-dependent transcription of gapII, which encodes an important gluconeogenic enzyme. We conclude that TrmB and TbsP co-regulate gluconeogenesis, with downstream impacts on lifestyle transitions in response to nutrients in Hfx. volcanii.

Introduction: Mitral annular disjunction (MAD) is a structural abnormality characterized by the systolic detachment of the posterior mitral annulus and the ventricular myocardium. It is usually observed coexistent with mitral valve prolapse(MVP) and associated with a mechanical dysfunction despite preserved electrical isolation function of the mitral annulus. Diagnosis depends on the detection of disjunction by imaging modalities as transthoracic echocardiography or cardiac magnetic resonance imaging (CMRI). This study aimed to evaluate left ventricular (LV) function using speckle tracking echocardiography in MVP patients with MAD. Methods: This study was designed as a prospective, single-center study including 103 patients with MVP and 40 age- and sex-matched control subjects. Transthoracic echocardiography and cardiac magnetic resonance imaging were performed to assess LV function and MAD presence. Results: MAD (+) MVP (n=34), MAD (-) MVP (n=69), and control (n=40) groups were enrolled in the study. Among the MVP patients, 34 (33%) had MAD. T negativity in the inferior leads on electrocardiography was more frequent in the MAD (+) group than in the MAD (-) patients (4.3% vs 20.6%, p=0.014). Mitral regurgitation degree, Pickelhaube sign (17.6% vs. 1.4%, p=0.005), and late gadolinium enhancement frequency (35.3% vs. 10.6%, p=0.002) were significantly higher in MAD (+) patients. MAD (+) patients had significantly impaired global longitudinal strain (GLS) -23.1±2.1 vs. -23.5±2.3, P<0.001), basal longitudinal strain (BLS) (-19.6±1.5 vs -20.5±1.9, P < 0.001), and Mid-Ventricular Longitudinal Strain(MVLS) (-22.2±1.7 vs -23.2±2.2, P<0.001) when compared to MAD (-) MVP patients, despite similar LV ejection fraction. All these values of MVP patients were also significantly lower than the control group. The mean MAD distance was 7.8 ± 3.2 mm in MAD (+) patients. Patients with 2 or more symptoms were higher in the MAD (+) group than in the MAD (-) group (4.3% vs 44.1%, P<0.001). Conclusion: This study demonstrated a significant decrease in longitudinal strain in MVP patients with MAD, indicating myocardial dysfunction. These findings suggest that MAD may contribute to LV dysfunction and highlight the importance of early detection in younger patients. Further research is needed to explore the functional implications and long-term outcomes of MAD.

Multi-sensor fusion-based localization technology has achieved high accuracy in autonomous systems. How to improve the robustness is the main challenge at present. The most commonly used LiDAR and camera are weather-sensitive, while the FMCW Radar has strong adaptability but suffers from noise and ghost effects. In this paper, we propose a heterogeneous localization method called Radar on LiDAR Map (RoLM), which aims to enhance localization accuracy without relying on loop closures by mitigating the accumulated error in Radar odometry in real time. Our approach involves embedding the data from both Radar and LiDAR sensors into a density map. We calculate the spatial vector similarity with an offset to determine the corresponding place index within the candidate map and estimate the rotation and translation. To refine the alignment, we utilize the Iterative Closest Point (ICP) algorithm to achieve optimal matching on the LiDAR submap. We conducted extensive experiments on the Mulran Radar Dataset, Oxford Radar RobotCar Dataset, and our dataset to demonstrate the feasibility and effectiveness of our proposed approach.

Solving quadratic equations with radicals on a computer with floating-point arithmetic requires great care to handle correctly all possible parameters. Literature on the subject glosses over the details, often considered as important but tedious to present. As a consequence, most implementations are flawed in one way or another. After having reviewed both the literature and the actual implementations in several programming languages and applications, we present an algorithm inspired from an exposition by Pat Sterbenz from 1974, adapted to take advantage of more recent researches in the field, which leads to a robust quadratic equation solver.

Understanding the evolutionary processes that influence fitness is critical to predicting species' responses to selection. Interactions among evolutionary processes including gene flow, drift and the strength of selection can lead to either local adaptation or maladaptation especially in heterogeneous landscapes. Populations experiencing novel environments or resources are ideal for understanding the mechanisms underlying adaptation or maladaptation, specifically in locally co-evolved interactions. We used the interaction between a native herbivore that oviposits on a patchily distributed introduced plant that in turn causes significant mortality to the larvae to test for signatures of local adaptation in areas where the two co-occurred. We used whole genome sequencing to explore population structure, patterns of gene flow and signatures of local adaptation. We found signatures of local adaptation in response to the introduced plant in the absence of strong population structure with no genetic differentiation and low genetic variation. Additionally, we found localized allele frequency differences within a single population between habitats with and without the lethal plant, highlighting the effects of strong selection. Our work highlights the potential for adaptation to occur in a fine-grained landscape in the presence of gene flow and low genetic variation.

Imminent rupture of infected aortic aneurysm presenting as lower back pain in an older patient: A case report Satoshi Takashima, Tadatsugu Morimoto, Takaomi Kobayashi, Hirohito Hirata, Tomohito Yoshihara, Masatsugu Tsukamoto, Masaaki Mawatari1 Department of Orthopedic Surgery, Faculty of Medicine, Saga University.Corresponding author: Tadatsugu MorimotoMailing address: Department of Orthopedic Surgery, Faculty of Medicine, Saga University, 5-1- 1 Nabeshima, Saga, JapanTel: +81-95-234-2343Fax: +81-95-234-2059E-mail:[email protected] of Interest: The authors declare that they have no competing interests to declare.【Cover letter】Editor-in-ChiefClinical case reportsDear Editor:I wish to submit a case report for publication in Clinical Case Reports, titled “Imminent rupture of infected aortic aneurysm presenting as lower back pain in an older patient: A case report.” This paper was co-authored by Tadatsugu Morimoto, Hirohito Hirata, Masatsugu Tsukamoto, Takaomi Kobayashi, Tomohito Yoshihara, and Masaaki Mawatari.This paper presents the clinical case of an elderly male patient who presented to our hospital with complaints of lower back pain and an infected aortic aneurysm at the time of his initial visit. The patient had poorly controlled type II diabetes mellitus. He presented to our hospital with back pain and numbness in the left lower extremity, which had increased gradually. Further examination revealed an infectious aortic aneurysm, and the patient was referred to the cardiovascular surgery department. We believe that this case makes a significant contribution to the literature because infective aortic aneurysms are rare and are expected to increase in the future due to an increase in the number of compromised hosts.Furthermore, we believe that there are lessons to be learned from the clinical course of our patient and that this paper will be of interest to the readers of your journal. We hope that the takeaway message will serve as a reminder to physicians regarding consideration of diagnosis of infectious aneurysms when patients present with lower back pain. A delayed diagnosis can have serious consequences and may lead to unsatisfactory clinical outcomes. We hope that the information provided in this report will aid in early detection and treatment of this disease.This manuscript has not been published or presented elsewhere in part or in entirety, and is not under consideration by another journal. We have read and understood your journal’s policies and believe that neither the manuscript nor the study violates any of these policies. The authors declare no conflicts of interest.Thank you for your consideration. I look forward to hearing from you.Sincerely,Satoshi TakashimaDepartment of Orthopedic Surgery, Faculty of Medicine, Saga University, 5-1-1 Nabeshima, Saga, JapanTel: +81-95-234-2343Fax: +81-95-234-2059E-mail: [email protected]【Manuscript】Keywords: Infected abdominal aortic aneurysm, lower back pain, misdiagnosis●Introduction:Infected abdominal aortic aneurysm (IAAA) is a rare but potentially fatal sequela of infectious inflammatory disease of the aortic wall. However, it is rather an under-recognized disease. The incidence of IAAA has increased in the recent years due to the aging population and increasing number of immunocompromised hosts1. Early diagnosis and management of IAAA can improve the prognosis and survival. However, the diagnosis of IAAA is sometimes challenging in the early stages due to its varied clinical presentation, such as lower back pain2.Herein, we report the case of an older patient in whom a differential diagnosis of spinal degenerative disease was considered due to symptoms such as lower back pain, lower extremity pain, and numbness. However, the patient was ultimately diagnosed with IAAA.Case history and examination:A 63-year-old male patient presented to the orthopedic outpatient clinic with complaints of back pain and left leg numbness, which had gradually increased over the past month. The patient had a history of diabetes mellitus (DM), hypertension, and dyslipidemia, but had self-interrupted his medications. No other significant medical history was elicited by the patient.Physical examination revealed lower back pain and the patient was able to walk without experiencing any neurological deficits. He experienced swelling and local heat in the left lower limb without any erythematous changes or cold sensations in the right leg. The left dorsalis pedis artery was palpable; however, the right dorsal foot artery was poorly palpable.Investigations were performed to localize the source. His laboratory data showed marked elevation of white blood cells (26.9 × 103/L) and C-reactive protein (17.96 mg/dL; normal range < 0.3 mg/dL), along with increased glycosylated hemoglobin (HbA1c) value (9.4%; normal range < 6.0%), Aspartate Aminotransferase (155 U/L; normal range <30 U/L), alanine transaminase (ALT) (93 U/L; normal range < 42 U/L), and gamma-glutamyltransferase (437 U/L; normal range < 64 U/L) levels were also markedly elevated indicating severe infection, DM and liver dysfunction. Fever, back pain, and elevated C-reactive protein levels were suggestive of pyogenic spondylitis. Therefore, lumbar spine radiography and Magnetic Resonance Imaging (MRI) examination were performed. However, lumbar spine radiography and MRI revealed no findings suggestive of pyogenic spondylitis (Figure 1). Based on these results, hepatobiliary system disease was suspected and a medicine specialist was consulted. The patient was admitted due to the suspicion of liver abscess, and underwent detailed examination and treatment.Differential diagnosis, investigation, and treatmentContrast-enhanced abdominal computed tomography (CT) revealed a pseudoaneurysm in the descending aorta. The surrounding soft tissues showed a small amount of gas in the L3/4 intervertebral space and above and below them, suggesting a left psoas abscess and L3/4 vertebral spondylodiscitis (Figure 2). On reviewing the radiograph and MRI, we realized that we had missed the imminent rupture of an infected abdominal aortic aneurysm (IAAA) (Figure 1). Blood cultures were positive for Gram-negative rods, and the microorganism was identified as Escherichia coli. Based on these findings, the patient was ultimately diagnosed with a left psoas abscess and septic shock secondary to IAAA. Ceftriaxone (CTRX) (2.0 g) was administered every 12 h. Pazufloxacin (PZFX) (1.0 g) was added every 12 h to allow tissue penetration. After the initiation of antibiotic therapy, no worsening tendency was observed. Antimicrobial susceptibility testing revealed that the isolate was susceptible to cefazolin (CEZ) at the minimal inhibitory concentrationvalue. Therefore, 2.0 g of CTRX being administered every 12 h was replaced with 1.0 g of CEZ every 6 h.●Outcome and follow-upFour days later, fever and back pain worsened again. Subsequent antibiotic treatment was continued, and the fever stabilized. Laboratory data showed an improvement in white blood cell count (14.5 × 103/L) and C-reactive protein levels (3.56 mg/dL; normal range < 0.3 mg/dL). However, CT revealed a ruptured IAAA despite the patient being fully alert. An emergency surgery was performed (Figure 3). The patient underwent aorto-right external iliac bypass, femoro-femoral bypass, enterectomy, and colostomy. He was managed in the Intensive Care Unit post-surgery, but was in a state of circulatory failure since the end of the surgery. The patient was confirmed dead on the fourth postoperative day.●Discussion:IAAA was first described by Osler in 1885 as an aneurysm caused by a bacterial embolus from infective endocarditis3. The concept has since been broadened to include all aneurysms caused by infections along with those caused by the addition of infection to an existing aneurysm4. IAAA is rare, accounting for 0.7%-3% of all aortic aneurysms, and is difficult to treat. The hospital mortality rate of patients with infected aortic aneurysms is high, ranging between 5-44%5,6. In the past, bacteremia from infective endocarditis and infective emboli were the main sources of infection. However, with the increasing prevalence of atherosclerosis and medically induced arterial injury (catheters and surgery) associated with aging and an increasing number of easily infected hosts such as those with diabetes, malignancy, and collagen disease, the incidence of IAAA has been reported to increase7.Correct and early medical examination and treatment are essential because IAAA is characterized by a faster rate of enlargement8 and a higher frequency of rupture due to its multifocal nature9, in comparison to abdominal aortic aneurysm (AAA). However, while AAA is often accompanied by severe symptoms, such as abdominal pain, impaired consciousness, and abnormal blood pressure, most cases of IAAA rupture are confined to the retroperitoneum, and rupture into the abdominal cavity is extremely rare10. Back pain is often the main symptom in IAAA rather than abdominal pain11. There have been a few cases of IAAA wherein physicians and spine surgeons engaged in lower back pain treatment, and a correct diagnosis was not reached. Therefore, physicians and spine surgeons should be aware of the possibility of IAAA when the patient complains of persistent back pain even after the administration of treatment for symptomatic relief. According to reports by various authors, rupture or impending rupture of an AAA should be suspected when (1) the patient is a middle-aged or older male with a history of an abdominal mass; (2) the pain is severe, with a definite onset time and a component of lateral abdominal pain; (3) there is no tenderness in the lumbar spine or surrounding soft tissues and no neurological symptoms; (4) the iliopsoas muscle shadow is abnormal on radiography; and (5) a beating mass is detected in the abdomen9. Palpation of the abdominal mass is recommended in patients with atypical lower back pain9.The present case involved an older male patient who did not present with lumbar spinal tenderness or neurological symptoms. Remarkably, an abdominal examination was not conducted; therefore, the presence of an abdominal mass was not initially established. Regrettably, the possibility of IAAA, which could have been a potential diagnosis, was not initially considered. In addition, as in the present case, missed imaging findings can also be problematic. IAAA is difficult to diagnose because the main symptom is fever, and the patient presents with a variety of symptoms, including thoracoabdominal pain and back pain, depending on the location of the aneurysm12. IAAAs are easily overlooked when fever is not the primary symptom. Blood investigations showing signs of infection, such as increased white blood cell counts and elevated C-reactive protein levels, along with positive blood cultures and the presence of soft tissue infiltration around the aorta, as shown on CT or magnetic resonance angiography (MRA), may lead to a diagnosis of IAAA. IAAA does not present with serious symptoms in the early stages, and back pain is the main complaint in 44% cases; therefore, orthopedicians are likely to be involved. However, in cases of lower back pain without the primary complaint of fever, abdominal examinations and blood investigations are rarely performed, and orthopedic surgeons tend to focus only on their area of expertise in diagnostic imaging13,14. Focusing on the spine and spinal cord, without paying attention to the soft tissues that appear in the imaging, can lead to overlooking serious diseases such as IAAA. In the present case, the diagnosis was made on the same day as the patient was suspected of a serious disease and internal medicine and radiology department was consulted, although it had been missed at the time of the initial visit. It should be noted that physicians treating lower back pain tend to look at the ABC (Alignment, Bone, Cartilage) but miss the soft tissues15. It is necessary to review images from the edges to ensure that entities such as aortic disease, neoplastic lesions of the spine, and hip disease are not missed during this process.●Consent:Written informed consent for the publication of this case report (including photographs, case progress, and data) was obtained from the patient’s relatives.【Author Contributions】ST and TM designed and outlined the main conceptual ideas. TY and TK collected the data. MT, MT, and HH. aided in the interpretation of the results and worked on the manuscript. MM supervised this study. ST wrote the manuscript with the support of MT, M.T, and HH. All the authors discussed the results and commented on the manuscript.【Funding Information】No funds, grants, or other support was received.【COI statement】The authors declare that they have no conflicts of interest.【Data availability statement】Data sharing is not applicable to this article as no datasets were generated or analyzed in the current study.【ORCID】Satoshi Takashima: 0009-0009-5013-5812.【References】1. Huang J., Cano, et al. Infected aneurysm of the native aorta due to coccidioides posadasii. Infectiou Disease Society of America 2021; 8(6)2. Ng J.H., Heng K.W.J. Infected native aortic aneurysm with spondylodiscitis in an elderly septic man with back pain. BMJ Case Rep 2021; 14(2)3.　　Lucas R.B.,Lucia R.,Aida R.,Manuel M. Mycotic Aortic Aneurysms. Aortic Aneurysm and Aortic Dissection 20184.　　Cheng-Hsin Lin., Ron-Bin Hsu. Primary Infected Aortic Aneurysm. Acta Cardiol Sin 2014; 30(6): 514-5215. Corvera J.S., Blitzer D., Copeland H., Murphy D., Hess P.J., Jr., Pillai S.T., Fehrenbacher, J.W. Repair of thoracic and thoracoabdominal mycotic aneurysms and infected aortic grafts using allograft. Ann Thorac Surg. 2018;106:1129–1135.6. Sharma A., Pawar P., Raju R., Ayappan M.K., Mathur K. Neo aortoiliac system repair of Burkholderia cepacia infected mycotic aneurysm with impending rupture. Indian J Vasc Endovasc Surg. 2018;5:129.7.　 Okada K, Yamanaka K, Sakamoto T, et al. In situ total aortic arch replacement for infected distal aortic arch aneurysms with penetrating atherosclerotic ulcer. J Thorac Cardiovasc Surg 2014; 148: 2096-100.8.　　Shao CC, McFarland GE, Beck AW. Emergent repair of infected aortic aneurysm with contained rupture using a femoral vein neoaortoiliac system. J Vasc Surg Cases Innov Tech 2021; 7(3): 502-5059.　 Padmanabhan C, Poddar A. Infections of the aorta: Indian J Thorac Cardiovasc Surg 2022; 38: 101-114.10.　 Tang T, Boyle J.R., et al. Inflammatory Abdominal Aortic Aneurysms 2005; 29(4): 353-36211. 　 Patelis N, Nana P, Spanos K, et al. The association of spondylitis and aortic aneurysm: Ann Vasc Surg 2021; 76: 555-56412.　 Garrity BM, Sugarman E, Pulley S. Abdominal aortic aneurysm rupture presenting with focal weakness and altered mental status: Int J Emerg Med 2022; 15(1): 2813. 　Waindim F, Crim J. MRI of difficult discs: Clin Radiol 2023; 78(3): 201-20814.　Onder O, Yarasir Y, Azizova A, Durhan G, Onur MR, Ariyurek OM. Errors discrepancies and underlying bias in radiology with case examples: a pictorial review. Insights imaging 2021; 12(1): 5115.　Goes PCK, Pathria MN. Radiographic/MR imaging correlation of the shoulder. Magn Reson Imaging Clin N Am 2019; 27(4): 575-585【Figure/Table】Figure 1Radiographic and Magnetic resonance imaging (MRI) of the lumbar spine before treatment.Lumbar spine radiograph and (B) MRI showing no findings suggestive of discitis or vertebral body destructive lesions at the time of the initial examination. We observed the presence of an imminent rupture of the infected abdominal aortic aneurysm (white arrow) on reexamination.