Causality between migraine and cardiovascular disease: a bidirectional Mendelian randomization study.

BACKGROUND: While growing evidence suggests a relationship between migraine and cardiovascular disease, the genetic evidence for a causal relationship between migraine and cardiovascular disease is still scarce. Investigating the causal association between migraine and cardiovascular disease is vital. METHODS: We carried out a bidirectional Mendelian randomization (MR) study including discovery samples and replication samples using publicly available genome-wide association study (GWAS) summary datasets and stringent screening instrumental variables. Four different MR techniques-Inverse variance weighted (IVW), MR ‒Egger, weighted median, and weighted mode-as well as various sensitivity analyses-Cochran's Q, IVW radial, leave-one-out (LOO), and MR-PRESSO-were utilized to investigate the causal relationship between cardiovascular disease and migraine. RESULTS: The protective causal effects of genetically predicted migraine on coronary artery disease (OR, 0.881; 95% CI 0.790-0.982; p = 0.023) and ischemic stroke (OR, 0.912; 95% CI 0.854-0.974; p = 0.006) were detected in forward MR analysis but not in any other cardiovascular disease. Consistently, we also discovered protective causal effects of coronary atherosclerosis (OR, 0.865; 95% CI 0.797-0.940; p = 0.001) and myocardial infarction (OR, 0.798; 95% CI 0.668-0.952; p = 0.012) on migraine in reverse MR analysis. CONCLUSION: We found a potential protective effect of migraine on coronary artery disease and ischemic stroke and a potential protective effect of coronary atherosclerosis and myocardial infarction on migraine. We emphasised epidemiological and genetic differences and the need for long-term safety monitoring of migraine medications and future research to improve cardiovascular outcomes in migraine patients.

Independent Risk Factors for Postoperative Recurrence of Patients with Primary Extramammary Paget's Disease: A Retrospective Analysis.

Background: Extramammary Paget's disease (EMPD) is a rare skin cancer with unclear pathogenesis, insidious progression, and high recurrence rate. The purpose of this study was to investigate the clinical features and postoperative recurrence factors of primary EMPD. Methods: We retrospectively analyzed the medical records of 40 patients with primary EMPD who underwent wide local excision surgery at a single medical center between 2009 and 2019. Risk factors for recurrence of primary EMPD were analyzed using multivariate binary logistic regression. Results: The study included 40 patients with primary EMPD, comprising 31 males (77.5%) and 9 females (22.5%), with a median age of 75.52 years (range 52-99 years). The most common lesion location was the scrotum (22 cases, 55.0%), followed by the vulva, penis, scrotum, underarm and anus. Multivariable regression analysis revealed significant differences in the presence of ill-defined tumour borders, exudation and nodules in the primary lesion affecting the relapse of primary EMPD (p<0.05). Conclusion: Our findings indicate that ill-defined tumour borders, exudation and nodules in the primary site should be considered as independent risk factors for disease recurrence, which may provide useful suggestions for the diagnosis, treatment and follow-up of primary EMPD.

Imaging features of pediatric meningiomas: emphasis on unusual locations.

PURPOSE: This article aims to analyze pediatric meningioma's imaging characteristics, especially those in unusual locations. METHODS: Pediatric patients with pathologically confirmed meningiomas at our hospital from January 2010 to January 2024 were enrolled. Meningiomas located in the cerebral convexity, parasagittal falcine region, anterior skull base, middle skull base, sphenoid ridge, cerebellopontine angle (CPA), olfactory groove, or juxtasella were considered in usual locations. Meningiomas found in other areas were considered in unusual locations. Clinical information, pathology results, and imaging features of pediatric meningiomas in usual and usual locations were analyzed and compared. RESULTS: A total of 18 patients (19 meningiomas) were enrolled, including 14 males and 4 females, with an average age of 14 years (ranging from 6 to 18 years). A total of 12 (63.2%) meningiomas were in the unusual location, including four (33.3%) were intraparenchymal, four (33.3%) were intraventricular, two (16.7%) were intraosseous, one (8.3%) case was in the paranasal sinus, and one (8.3%) was intraspinal. The meningiomas in unusual locations usually lacked the meningeal tail sign, and the misdiagnosis rate on preoperative imaging was significantly higher than that of meningiomas in usual locations. CONCLUSION: Pediatric meningiomas are prone to occur in unusual locations. When they occur in usual locations, they often lack typical radiographic features of meningiomas, leading to potential misdiagnosis before surgery. Recognition of the imaging characteristics of meningiomas in unusual locations in children may facilitate accurate preoperative imaging diagnosis.

Primary lung adenocarcinoma with breast metastasis harboring the EML4­ALK fusion: A case report.

Pulmonary adenocarcinoma with breast metastasis is rarely encountered in clinical practice. Therefore, precise clinical diagnosis of patients with this disease is crucial when selecting subsequent treatment modalities and for overall prognosis assessment. The present study reported on a case of lung cancer with breast metastasis harboring the EML4-ALK fusion. The patient was initially diagnosed with triple-negative breast cancer with lung metastasis, but comprehensive breast cancer treatment was ineffective. Reevaluation of the patient's condition via lung biopsy revealed primary lung adenocarcinoma. In addition, the results of genetic testing revealed the EML4-ALK fusion protein in both lung and breast tissues. After treatment with ALK inhibitors, the patient's symptoms improved rapidly. This case highlights the prolonged diagnostic journey from presentation with a breast mass to ultimately being diagnosed with lung cancer with breast metastasis, underscoring the critical need for heightened awareness among clinicians regarding the possibility of rare metastatic patterns. Timely identification of lung cancer with breast metastasis, facilitated by comprehensive genetic testing, not only refines treatment decisions but also emphasizes the importance of interdisciplinary collaboration in navigating complex clinical scenarios. Such insight contributes to the ongoing development of personalized cancer care that guides clinicians toward more effective and tailored therapeutic strategies for patients with similar diagnostic challenges.

Case report: Pulmonary artery sarcoma diagnosed through rare brain metastases.

We present the case of a 33-year-old male referred across several hospitals because of suspected chronic thromboembolic pulmonary hypertension (CTEPH). Initially admitted in October 2022 for a recurrent, severe cough and diagnosed with CTEPH, he received anticoagulant therapy. However, his symptoms worsened, necessitating a transfer to another facility for thrombolysis treatment. Following an episode of syncope, an MRI scan revealed a metastatic brain tumor. Subsequently, he experienced a third transfer to our hospital, emergency surgery was performed to alleviate cerebral edema and excise a lesion in the left frontal lobe. Postoperative pathology was inconclusive, but a multidisciplinary team meeting, aided by experienced radiologists, eventually confirmed a diagnosis of pulmonary artery sarcoma (PAS) with systemic metastases. This case underscores the necessity of promptly ruling out PAS in patients presenting with significant emboli in the central pulmonary arteries and suggests early referral to specialized centers for suspected cases.

Gingival diffuse large B-cell lymphoma: report of 2 cases.

Diffuse large B-cell lymphoma (DLBCL) in the oral gums is very rare and is prone to misdiagnosis and mistreatment. In this paper, 2 cases of oral gingival DLBCL were reported. Their clinicopathological features, diagnosis, and differential diagnosis were discussed based on the literature of 21 cases of gingival DLBCL reported at home and abroad from 2008 to 2023.

Effect of scanning speeds on mechanical properties of CoCrNi medium entropy alloy prepared by laser additive manufacturing.

Medium entropy alloy (MEA) is a hot spot in the field of material research in recent years. At present, the most widely used processing method of MEAs is "casting-rolling-heat treatment", and the preparation of CoCrNi MEA by laser additive manufacturing (LAM) is still in primary stage. In this study, CoCrNi MEAs were fabricated with different scanning speeds by laser additive manufacturing, and the influence of scanning speed on its mechanical properties was investigated. The results show that higher scanning speed can significantly improve the mechanical properties of CoCrNi MEA. Compared with the low-speed laser additive manufacturing (LSLAM) MEA, the tensile strength of high-speed laser additive manufacturing (HSLAM) MEA is increased by 5.6 % and the fracture strain is increased by 60 %, which is mainly due to the entanglement of 1/6<112> and 1/2<110> dislocations and the defect structure at the grain boundary. LAM is a promising technology that can promote the development and application of MEAs in industry.

Transcriptome profile analysis revealed the potential mechanism of LIPUS treatment for Adriamycin-induced chronic kidney disease rat.

Background: Developing effective therapeutic strategies to delay the progression of chronic kidney disease (CKD) remains a significant challenge. Low-intensity pulsed ultrasound (LIPUS) has demonstrated potential for treating CKD, but the underlying molecular mechanisms are still elusive. This study aimed to evaluate the therapeutic efficacy of LIPUS and to elucidate the involved genes and signaling pathways. Methods: The CKD model was established in rats using Adriamycin (ADR). The bilateral kidneys of CKD rats were continuously stimulated with LIPUS for a period of four weeks. The therapeutic efficacy was defined by renal function and histopathological evaluation. RNA sequencing was employed to profile the transcriptome of rat kidneys in each group. Cluster analysis was utilized to identify differentially expressed genes (DEGs), followed by enrichment analysis of their associated pathways using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases. Results: LIPUS treatment improved ADR-induced renal dysfunction in the CKD group. Renal fibrosis and pathological damages were also alleviated in the ADR + LIPUS group compared to the ADR group. Cluster analysis identified 844 DEGs. GO enrichment analysis revealed enrichment in inflammatory response terms, while KEGG enrichment analysis highlighted the nuclear factor kappa B (NF-κB) signaling and ferroptosis-related pathways. Conclusion: Continuous LIPUS treatment improved ADR-induced renal fibrosis and dysfunction. The therapeutic effect of LIPUS was primarily due to its ability to suppress the CKD-related inflammation, which was associated with the modulation of the NF-κB and ferroptosis signaling pathways. These findings provide a new insight into the potential molecular mechanisms of LIPUS in treating CKD. Further research is necessary to confirm these findings and to identify potential therapeutic targets within these pathways.

Case Report: Myocardial dissection caused by ruptured sinus of Valsalva aneurysm in association with a bicuspid aortic valve.

In this report, we present a case of left-right sinus fusion in a Ruptured sinus of Valsalva aneurysm (RSVA) that perforated into the myocardium, giving rise to myocardial dissection. The existence of an anomalous bicuspid aortic valve (BAV) is contemplated as a potential etiological element in this context. Employing multimodal imaging modalities, encompassing transthoracic echocardiography and computed tomography (CT), facilitated the visualization of a dissecting hematoma situated within the myocardium subsequent to the RSVA. Following this, our patient underwent an Cabrol surgical intervention, received patch repair, and underwent mitral valve annuloplasty, during which a three-year period transpired without the occurrence of any deleterious cardiac events. In summary, this report establishes the cornerstone for the surgical intervention of RSVA, shedding light on the efficacious handling of RSVA-associated myocardial dissection. It posits that the presence of a BAV may serve as a predisposing factor to RSVA rupture, potentially elevating the susceptibility to myocardial dissection. The utilization of diverse multimodal imaging methodologies played an indispensable role in the detection of a hematoma within the myocardial tissue subsequent to the RSVA rupture. The uneventful three-year postoperative follow-up of the patient underscores the efficacy of the undertaken interventions.

CRISPR-Based KCC2 Upregulation Attenuates Drug-Resistant Seizure in Mouse Models of Epilepsy.

OBJECTIVE: The precise intervention of K-Cl cotransporter isoform 2 (KCC2) as a promising target for drug-resistant epilepsy remains elusive. METHODS: Here, we used a CRISPRa system delivered by adeno-associated viruses to specifically upregulate KCC2 in the subiculum to confirm its therapeutic potential in various in vivo epilepsy models. Calcium fiber photometry was used to reveal the role of KCC2 in the restoration of impaired GABAergic inhibition. RESULTS: CRISPRa system effectively upregulated KCC2 expression both in in vitro cell culture and in vivo brain region. Delivery of CRISPRa with adeno-associated viruses resulted in upregulating the subicular KCC2 level, contributing to alleviating the severity of hippocampal seizure and facilitating the anti-seizure effect of diazepam in a hippocampal kindling model. In a kainic acid-induced epilepticus status model, KCC2 upregulation greatly increased the termination percentage of diazepam-resistant epilepticus status with the broadened therapeutic window. More importantly, KCC2 upregulation attenuated valproate-resistant spontaneous seizure in a kainic acid-induced chronic epilepsy model. Finally, calcium fiber photometry showed CRISPRa-mediated KCC2 upregulation partially restored the impaired GABAA -mediated inhibition in epilepsy. INTERPRETATION: These results showed the translational potential of adeno-associated viruses-mediated delivery of CRISPRa for treating neurological disorders by modulating abnormal gene expression that is directly associated with neuronal excitability, validating KCC2 as a promising therapeutic target for treating drug-resistant epilepsy. ANN NEUROL 2023;94:91-105.

Establishing a prognostic model of chromatin modulators and identifying potential drug candidates in renal clear cell patients.

BACKGROUND: Renal carcinoma is a common malignant tumor of the urinary system. Advanced renal carcinoma has a low 5-year survival rate and a poor prognosis. More and more studies have confirmed that chromatin regulators (CRs) can regulate the occurrence and development of cancer. This article investigates the functional and prognostic value of CRs in renal carcinoma patients. METHODS: mRNA expression and clinical information were obtained from The Cancer Genome Atlas database. Univariate Cox regression analysis and LASSO regression analysis were used to select prognostic chromatin-regulated genes and use them to construct a risk model for predicting the prognosis of renal cancer. Differences in prognosis between high-risk and low-risk groups were compared using Kaplan-Meier analysis. In addition, we analyzed the relationship between chromatin regulators and tumor immune infiltration, and explored differences in drug sensitivity between risk groups. RESULTS: We constructed a model consisting of 11 CRs to predict the prognosis of renal cancer patients. We not only successfully validated its feasibility, but also found that the 11 CR-based model was an independent prognostic factor. Functional analysis showed that CRs were mainly enriched in cancer development-related signalling pathways. We also found through the TIMER database that CR-based models were also associated with immune cell infiltration and immune checkpoints. At the same time, the genomics of drug sensitivity in cancer database was used to analyze the commonly used drugs of renal clear cell carcinoma patients. It was found that patients in the low-risk group were sensitive to medicines such as axitinib, pazopanib, sorafenib, and gemcitabine. In contrast, those in the high-risk group may be sensitive to sunitinib. CONCLUSION: The chromatin regulator-related prognostic model we constructed can be used to assess the prognostic risk of patients with clear cell renal cell carcinoma. The results of this study can bring new ideas for targeted therapy of clear cell renal carcinoma, helping doctors to take corresponding measures in advance for patients with different risks.

Sitagliptin Ameliorates Creb5/lncRNA ENSMUST00000213271-Mediated Vascular Endothelial Dysfunction in Obese Mice.

PURPOSE: Obesity is mediated by the changes in dyslipidemia, oxidative stress, and inflammation, leading to vascular endothelial dysfunction. Glucagon-like peptide-1 (GLP-1) analogues and dipeptidyl peptidase-4 inhibitors prevent the development of endothelial dysfunction. However, the underlying mechanism still remains largely unclear. Long non-coding RNAs (lncRNAs), one class of non-coding small RNAs, have been shown to exert a regulatory impact on the endothelial function in obesity. This study aimed to investigate whether the elevation of GLP-1 by a DPP-4 inhibitor sitagliptin improved vascular endothelial function by modulating lncRNAs in obese mice and to clarify the underlying molecular mechanism. METHODS: Male C57BL/6J mice were fed a high-fat diet for 4 months to induce obesity and some obese mice were treated with sitagliptin for the last 1 month. Levels of total cholesterol (TC), high-density lipoprotein (HDL), low-density lipoprotein (LDL), and glucagon-like peptide-1 (GLP-1) in plasma were detected by ELISA. LncRNA expression profile was analyzed via microarray. Aortic relaxations were examined by myograph. Protein expressions and phosphorylations were determined using western blot. The differentially expressed lncRNAs were validated using qRT-PCR. RESULTS: Obese mice exhibited increased levels of TC and LDL, decreased concentrations of HDL and GLP-1 in plasma, and impaired aortic endothelium-dependent relaxations; such effects could be reversed by sitagliptin. Moreover, the altered expression profile of lncRNAs in the obese mouse aortae could be modulated by sitagliptin. Consistent with microarray analysis, qRT-PCR also revealed that lncRNA ENSMUST00000213271 was up-regulated in obese mouse aortae and aortic endothelial cells (ECs), which could be down-regulated by sitagliptin. Creb5 silencing reduced lncRNA ENSMUST00000213271 in obese mouse ECs. Knockdown of either Creb5 or lncRNA ENSMUST00000213271 restored the activation of AMPK/eNOS in obese mouse ECs. Furthermore, sitagliptin also suppressed Creb5 and lncRNA ENSMUST00000213271 and increased the phosphorylations of AMPK and eNOS in obese mice. CONCLUSION: Creb5/lncRNA ENSMUST00000213271 mediated vascular endothelial dysfunction through inhibiting AMPK/eNOS cascade in obesity. Elevation of GLP-1 by sitagliptin possibly improved endothelial function by suppressing Creb5/lncRNA ENSMUST00000213271 and subsequently restoring AMPK/eNOS activation in obese mice. This study will provide new evidence for the benefits of GLP-1 against vasculopathy in obesity.

A case of death of patient with ovarian fibroma combined with Meigs Syndrome and literature review.

Ovarian fibroma is the most common benign pure stromal tumor. It has no specific clinical manifestation, most of which are pelvic or adnexal masses. 10-15% of cases with hydrothorax or ascites, after tumor resection, hydrothorax and ascites disappear, known as Meigs Syndrome. The elevated level of CA125 in a few patients was easily misdiagnosed as ovarian malignant tumor. A case of bilateral Ovarian fibroma associated with Meigs Syndrome is reported and the literature is reviewed in order to improve the understanding of the changes and avoid misdiagnosis.

Lateral Hypothalamus Calcium/Calmodulin-Dependent Protein Kinase II α Neurons Encode Novelty-Seeking Signals to Promote Predatory Eating.

Predatory hunting is an innate appetite-driven and evolutionarily conserved behavior essential for animal survival, integrating sequential behaviors including searching, pursuit, attack, retrieval, and ultimately consumption. Nevertheless, neural circuits underlying hunting behavior with different features remain largely unexplored. Here, we deciphered a novel function of lateral hypothalamus (LH) calcium/calmodulin-dependent protein kinase II α (CaMKIIα +) neurons in hunting behavior and uncovered upstream/downstream circuit basis. LH CaMKIIα + neurons bidirectionally modulate novelty-seeking behavior, predatory attack, and eating in hunting behavior. LH CaMKIIα + neurons integrate hunting-related novelty-seeking information from the medial preoptic area (MPOA) and project to the ventral periaqueductal gray (vPAG) to promote predatory eating. Our results demonstrate that LH CaMKIIα + neurons are the key hub that integrate MPOA-conveyed novelty-seeking signals and encode predatory eating in hunting behavior, which enriched the neuronal substrate of hunting behavior.

Significant efficacy of paclitaxel plus carboplatin (TP) as a neoadjuvant regimen for metaplastic squamous cell carcinoma of the breast: a rare case report and literature review.

Background: Metaplastic squamous cell carcinoma of the breast (MSCCB) is a rare and aggressive type of cancer. So far, no standard treatment regimen has been established due to the absence of clinical data. Case Description: We report a case of a 48-year-old female admitted to our hospital as a result of a left breast mass with skin rupture. Core needle biopsy under ultrasonic guidance confirmed MSCCB. Immunohistochemistry revealed negative staining for estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor type 2 (HER2/neu). After receiving 4 cycles of paclitaxel and carboplatin neoadjuvant chemotherapy, the patient was treated with modified radical mastectomy. Postoperative pathology revealed a Miller-Payne score of 4 and no metastasis in the axillary lymph nodes (0/13), indicating a good response to neoadjuvant chemotherapy. She recovered well post-surgery and was discharged to home after admission. No recurrence was identified during the 2 years post-surgery follow-up. Conclusions: MSCCB is a rare and aggressive type of cancer. However, the treatment of MSCCB has not been standardized due to its rarity. Given the observation that the majority of patients with MSCCB had ER, PR, HER2-negative neoplasms, we refer to the triple negative breast cancer (TNBC) treatment protocol. TP regimen was demonstrated to be an effective treatment for TNBC. The results of this case suggest that the TP regimen is effective in neoadjuvant chemotherapy of MSCCB.

The Effect of Health on the Elderly's Labor Supply in Rural China: Simultaneous Equation Models With Binary, Ordered, and Censored Variables.

In this study, we examined the effect of health on the elderly's labor supply in rural China based on the data of the Chinese Health and Nutrition Survey (CHNS) from 1997 to 2006. We used simultaneous equations to address the endogeneity problem of health and estimate the models with censored data of labor supply by the full information maximum likelihood estimation. We found that the failing health does not significantly decrease the elderly's labor supply in rural areas when using both the subjective (self-reported health status) and objective (hypertension diagnosed or not) health indicators. Our finding indicates the phenomenon of "ceaseless toil" for the elderly in rural China, i.e., the elderly almost work their whole life even if they are not physically capable. The results remain robust when using a two-stage limited information maximum likelihood estimation.

Soluble Epoxide Hydrolase Inhibitor t-AUCB Ameliorates Vascular Endothelial Dysfunction by Influencing the NF-κB/miR-155-5p/eNOS/NO/IκB Cycle in Hypertensive Rats.

Epoxyeicosatrienoic acids (EETs), angiogenic mediators degraded by soluble epoxide hydrolase (sEH), have been shown to exert beneficial effects on the cardiovascular system. The current study assessed the impact of increased EETs with an sEH inhibitor, t-AUCB, on two-kidney-one-clip (2K1C)-induced renovascular endothelial dysfunction, associated with hypertension, in rats. The hypertensive rats exhibited increased systolic blood pressure, reduced renal blood flow, impaired endothelium-dependent relaxation and eNOS phosphorylation in the renal arteries, elevated ROS production in the endothelium of the renal arteries, and decreased EET levels in plasma, the renal arteries, and endothelial cells; however, t-AUCB reversed all the deleterious effects. Moreover, we found that the stimulation of AMPK/UCP2 scavenged ROS and restored endothelial function in the renal arteries of hypertensive rats undergoing therapy with t-AUCB. In addition, we were the first to reveal the potential role of miR-155-5p in the occurrence and development of vascular endothelial dysfunction in hypertension. Importantly, t-AUCB recovered NO bioavailability by regulating the NF-κB/miR-155-5p/eNOS/NO/IκB cycle after the activation of AMPK/UCP2 and the subsequent inhibition of ROS in hypertensive rat renal artery endothelial cells. This study will provide evidence for this additional new mechanism, underlying the benefits of EETs and the related agents against hypertensive vasculopathy.

In missed abortion the decrease of IGF-1 down-regulates PI3K/AKT signaling pathway reducing the secretion of progesterone and ß-hCG.

OBJECTIVE: To explore whether the reduction of IGF-1 in missed abortion down-regulates PI3K/AKT signaling pathway, thereby causing trophoblast cell apoptosis and reducing the secretion of ß-hCG and progesterone. DESIGN: 12 pairs of serum and villous tissues were selected from missed abortion patients and normal early pregnant women who had terminated pregnancy by artificial abortion. The subjects in two groups had same age and gestational week. Wes Simple Western system and qRT-PCR were used to detect the expression of IGF-1, IGF-1R, PI3K/AKT signaling pathway and apoptosis-related factors in villous tissues. Radioimmunoassay and Enzyme-linked immunosorbent assay were used to detect ß-hCG, progesterone and IGF-1 in serum. RESULTS: The serum levels of ß-hCG, progesterone and IGF-1 were decreased in missed abortion group than those in normal early pregnant women. In addition, compared with normal early pregnant women, the genes and proteins levels of IGF-1 and PI3K/AKT signaling pathway and anti-apoptosis related factors were significantly decreased. CONCLUSIONS: Our results suggested that the reduction of IGF-1 in missed abortion patients could down-regulate the expression of PI3K/AKT signaling pathway, thereby increasing the apoptosis of trophoblast cells, leading to decreased secretion of ß-hCG and progesterone, which may be one of the important mechanisms of missed abortion.

Evaluating the Residual Stress and Its Effect on the Quasi-Static Stress in Polyethylene Pipes.

Residual stress is generated during the production process. It can significantly affect the mechanical performance of pressurized polymer pipes. In this paper, six polyethylene (PE) pipes, including three high-density PEs (HDPE) and three medium-density PEs (MDPE) provided by different suppliers, were tested using a one-slit-ring method to measure the residual stress distribution along the hoop direction. Finite element (FE) simulation and mechanical testing were also employed in an iteration process to obtain the mechanical parameters of the six PE pipes. For the same PE pipe code from different suppliers, the results show that the magnitude of the residual hoop stress can be very different, resulting in different mechanical behaviors. In addition, the results are proposed to explain the scenario that was reported previously, i.e., the different critical quasi-static stress (the time-independent stress) levels of the PE pipes with the same pipe code. Since the quasi-static stress is expected to dominate the long-term behavior of the PE pipes, it is of great importance to carefully consider the effect of the residual stress on the determination of the quasi-static stress.