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Meng X, Lv A, Tang M, Liu X, Wang X, Li Y, Chai Y, Yang Q, Kou C, Zhang L, Li M, Zhang H. Non-thyroidal disease syndrome in patients with systemic lupus erythematosus: relation to disease inflammatory activity. Clin Rheumatol 2024; 43:1551-1558. [PMID: 38578510 DOI: 10.1007/s10067-024-06947-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 03/01/2024] [Accepted: 03/22/2024] [Indexed: 04/06/2024]
Abstract
OBJECTIVE To identify risk factors for the development of non-thyroidal illness syndrome (NTIS) in patients with systemic lupus erythematosus (SLE). METHODS A retrospective analysis of 517 SLE patients and 1034 age-and sex-matched healthy population was conducted to compare the prevalence of NTIS in these two groups, and to analyze the laboratory and clinical characteristics of SLE patients with NTIS. Finally Logistic regression analysis was used to determine the risk factors for NTIS in SLE patients. RESULTS The prevalence of NTIS in the SLE patients was significantly higher than that in controls (39.7% vs. 1.0%, P < 0.001). In SLE patients, compared with euthyroidism patients, NTIS patients exhibited higher levels of neutrophils, hepatic enzymes, kidney damage markers, inflammatory markers and SLE disease activity index (SLEDAI). They also had a higher incidence of organ insufficiency and positive antibodies such as anti-ds-DNA antibodies and anti-SSA antibodies. However, NTIS patients had lower levels of hemoglobin, lymphocytes, platelets, serum albumin, and complement. Additionally, NTIS patients had a shorter duration of lupus and lower utilization of disease-modifying antirheumatic drugs (DMARDs) (P < 0.05). Logistic regression analysis showed that elevated SLEDAI (OR = 1.060, 95%CI 1.022-1.099, P = 0.002), elevated systemic immune-inflammation index (SII) (OR = 1.003, 95%CI 1.001-1.007, P = 0.026), elevated erythrocyte sedimentation rate (ESR) (OR = 1.019, 95%CI 1.010-1.028, P < 0.001), and hepatic insufficiency (OR = 1.916, 95% CI 1.173-3.131, P = 0.009) were independent risk factors for the development of NTIS in SLE. DMARDs treatment (OR = 0.495, 95% CI 0.306-0.799, P < 0.001) was an independent protective factor for NTIS. CONCLUSIONS Inflammatory activity in SLE patients is associated with the development of NTIS. Key Points • Inflammatory activity indexes such as SLEDAI, SII, and ESR are independent risk factors for NTIS in SLE patients.
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Liu X, Yuan J, Wang X, Tang M, Meng X, Zhang L, Wang S, Zhang H. Association between rheumatoid arthritis and autoimmune thyroid disease: evidence from complementary genetic methods. Endocrine 2024; 84:171-178. [PMID: 37884826 DOI: 10.1007/s12020-023-03571-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Accepted: 10/09/2023] [Indexed: 10/28/2023]
Abstract
OBJECTIVES To assess the causal association of Rheumatoid Arthritis (RA) with Autoimmune thyroid disease (AITD). METHOD Complementary genetic approaches, including genetic correlation, Mendelian randomization (MR) and colocalization analysis, were conducted to assess the potential causal association between RA and AITD using summary statistics from large-scale genome-wide association studies (GWASs). Various sensitivity analyses had been conducted to assess the robustness and the consistency of the findings. RESULTS The linkage disequilibrium score regression revealed a shared genetic structure between RA and AITD, with the significant genetic correlation between RA and autoimmune hyperthyroidism and autoimmune hypothyroidism estimated to be 0.3945 (P = 2.83 × 10-6) and 0.2771 (P = 1.04 × 10-6) respectively. The results of MR analysis showed that RA had a positive causal relationship with autoimmune hypothyroidism and autoimmune hyperthyroidism. The odds ratio (OR) were 1.29 (95% CI, 1.17-1.42; P = 1.08 × 10-7) and 1.47 (95% CI, 1.25-1.72; P = 1.85 × 10-6), respectively. In reverse MR analysis, autoimmune hypothyroidism had a positive causal relationship with RA, OR was 1.51 (95% CI, 1.37-1.66; P = 1.10 × 10-16); autoimmune hyperthyroidism had no causal relationship with RA relationship (P = 0.22). Similar results were found using different MR methods. In addition, colocalization analysis suggested that shared causal variants existed between RA and AITD. CONCLUSIONS Our study suggested a potentially causal effect of genetically predicted RA on autoimmune hyperthyroidism and a bidirectional causal relationship between RA and autoimmune hypothyroidism was also observed with complementary genetic approaches, which supports the importance and necessity of thyroid function screening and monitoring in RA patient management in clinical practice.
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Liu X, Yuan J, Liu S, Wang X, Tang M, Meng X, Li Y, Chai Y, Wang Y, Tian G, Liu X, Zhou H, Kou C, Zhang L, Yuan Z, Zhang H. The causal relationship between autoimmune thyroid disorders and telomere length: A Mendelian randomization and colocalization study. Clin Endocrinol (Oxf) 2024; 100:294-303. [PMID: 38214116 DOI: 10.1111/cen.15004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 10/20/2023] [Accepted: 12/05/2023] [Indexed: 01/13/2024]
Abstract
This study aimed to evaluate whether there is a causal relationship between autoimmune thyroid disorders (AITDs) and telomere length (TL) in the European population and whether there is reverse causality. In this study, Mendelian randomization (MR) and colocalization analysis were conducted to assess the potential causal relationship between AITDs and TL using summary statistics from large-scale genome-wide association studies, followed by analysis of the relationship between TL and thyroid stimulating hormone and free thyroxine (FT4) to help interpret the findings. The inverse variance weighted (IVW) method was used to estimate the causal estimates. The weighted median, MR-Egger and leave-one-out methods were used as sensitivity analyses. The IVW method results showed a significant causal relationship between autoimmune hyperthyroidism and TL (β = -1.93 × 10-2 ; p = 4.54 × 10-5 ). There was no causal relationship between autoimmune hypothyroidism and TL (β = -3.99 × 10-3 ; p = 0.324). The results of the reverse MR analysis showed that genetically TL had a significant causal relationship on autoimmune hyperthyroidism (IVW: odds ratio (OR) = 0.49; p = 2.83 × 10-4 ) and autoimmune hypothyroidism (IVW: OR = 0.86; p = 7.46 × 10-3 ). Both horizontal pleiotropy and heterogeneity tests indicated the validity of our bidirectional MR study. Finally, colocalization analysis suggested that there were shared causal variants between autoimmune hyperthyroidism and TL, further highlighting the robustness of the results. In conclusion, autoimmune hyperthyroidism may accelerate telomere attrition, and telomere attrition is a causal factor for AITDs.
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Cai X, Zhang J, Li L, Liu L, Tang M, Zhou X, Peng C, Li X, Chen X, Xu M, Zhang H, Wang J, Huang Y, Li T. Copy Number Alterations Predict Development of OSCC from Oral Leukoplakia. J Dent Res 2024; 103:138-146. [PMID: 38217281 DOI: 10.1177/00220345231217160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2024] Open
Abstract
Oral leukoplakia (OLK) is a common type of potentially malignant disorder. Early identification of the malignancy potential leads to a better management of OLK and prediction of development of oral squamous cell carcinoma (OSCC). However, there has been no effective biomarker to assess the risk of malignancy in OLK. Genomic copy number alteration (CNA) is a complex chromosomal structural variation in the genome and has been identified as a potential biomarker in multiple cancers. This study aimed to develop a predictive model for the malignant transformation risk of OLK by copy number analysis. A total of 431 OLK samples with long-term follow-up (median follow-up of 67 mo) from multiple academic centers were analyzed for CNAs. CNA events increased with the severity of hyperplasia, mild dysplasia, moderate dysplasia, and severe dysplasia. More CNA events were present in patients with OLK who later developed OSCC than in those with OLK who did not. By multivariate Cox regression analysis, the OLK of the CNA scorehigh group showed an increased risk of malignant transformation than the CNA scorelow group (P < 0.001). A CNA score model was developed to accurately predict the prognosis (area under the receiver operating characteristic curve [AUC] = 0.879; 95% confidence interval [CI], 0.799-0.959) and was validated using data from 2 external centers (AUC = 0.836, 95% CI, 0.683-0.989; AUC = 0.876, 95% CI, 0.682-1.000), and all of them showed better prediction performances than histopathological grade in assessing the transformation risk of OLK. Furthermore, we performed CNA models among 4 subgroups of OLK with hyperplasia, mild dysplasia, moderate dysplasia, and severe dysplasia and found that CNA score can accurately predict malignant transformation of different subgroups. CNA score may be a useful biomarker to predict malignant transformation of OLK. Subtyping of OLK by the CNA score could contribute to better management of OLK and predicting development of OSCC.
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Liu X, Yuan J, Liu S, Tang M, Meng X, Wang X, Li Y, Chai Y, Kou C, Yang Q, Li J, Zhang L, Guan Q, Zhang H. Investigating causal associations among gut microbiota, metabolites and autoimmune hypothyroidism: a univariable and multivariable Mendelian randomization study. Front Immunol 2024; 14:1213159. [PMID: 38239342 PMCID: PMC10794377 DOI: 10.3389/fimmu.2023.1213159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 12/04/2023] [Indexed: 01/22/2024] Open
Abstract
Background Accumulating evidence suggests that the gut microbiota and its metabolites may be involved in autoimmune hypothyroidism. However, the causal association between gut microbiota, metabolites and autoimmune hypothyroidism remains to be determined. Methods Instrumental variables were screened from the GWAS datasets of 211 gut microbiota taxonomic groups, gut microbiota-derived metabolites, and autoimmune hypothyroidism. Univariable Mendelian randomization (MR) and multivariable Mendelian randomization (MVMR) were used to analyse the potential causal relationship between autoimmune hypothyroidism, these metabolites, or these microbiota. During the MR analysis, we alternated multiple MR methods with different model assumptions to assess the consistency and robustness of the findings: inverse variance weighted (IVW), weighted median, MR pleiotropy residual sum and outlier (MRPRESSO) and MR-Egger methods. Reverse MR analysis was performed to assess the possibility of reverse causality. Finally, enrichment analyses were used to investigate potential biofunctions. Results The IVW results of univariable MR showed that the phyla Actinobacteria, genus DefluviitaleaceaeUCG011, genus Eggerthella, family Defluviitaleaceae, genus Subdoligranulum, genus RuminococcaceaeUCG011, and genus Intestinimonas were associated with autoimmune hypothyroidism. After FDR adjustment, the absence of a causal relationship between gut microbiota and autoimmune hypothyroidism (PFDR > 0.05) suggested a possible marginal association. The results on gut metabolites showed that N-(3-furoyl)glycine, pipecolate, phenylalanine, allantoin, indololactate and alanine were associated with autoimmune hypothyroidism. After FDR correction, only indololactate was associated with hypothyroidism (OR=1.592; 95% CI, 1.228-2.065; PFDR= 0.036). Family Defluviitaleaceae and genus DefluviitaleaceaeUCG011 were suggestively significant in the MVMR. The results of reverse MR analysis showed no reverse causality between autoimmune hypothyroidism and the identified gut microbiota. Enrichment analysis revealed that several key regulatory pathways were significantly enriched. Conclusion This study supported that there were beneficial or detrimental causal effects of gut microbiota and its metabolites on autoimmune hypothyroidism risk, which provides more theoretical support for mechanistic research on the "thyroid-gut" axis.
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Yuan J, Liu X, Wang X, Zhou H, Wang Y, Tian G, Liu X, Tang M, Meng X, Kou C, Yang Q, Li J, Zhang L, Yuan Z, Zhang H. Association Between Educational Attainment and Thyroid Function: Results From Mendelian Randomization and the NHANES Study. J Clin Endocrinol Metab 2023; 108:e1678-e1685. [PMID: 37285488 DOI: 10.1210/clinem/dgad344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 05/13/2023] [Accepted: 06/05/2023] [Indexed: 06/09/2023]
Abstract
CONTEXT Many observational studies have reported on the association between educational attainment (EA) and thyroid function, but the causal relationship remains unclear. OBJECTIVE We aimed to obtain causal effects of EA on thyroid function and to quantify the mediating effects of modifiable risk factors. METHODS Two-sample mendelian randomization (MR) was performed by using summary statistics from large genome-wide association studies (GWAS) to assess the effect of EA on thyroid function, including hypothyroidism, hyperthyroidism, thyrotropin (TSH), and free thyroxine (FT4). A multivariable analysis was conducted to assess the mediating role of smoking and help to explain the association between EA and thyroid function. Similar analysis was further performed using data from the National Health and Nutrition Examination Survey (NHANES) 1999 to 2002. RESULTS In MR analysis, EA was causally associated with TSH (β = .046; 95% CI, 0.015-0.077; P = 4.00 × 10-3), rather than hypothyroidism, hyperthyroidism, and FT4. Importantly, smoking could serve as a mediator in the association between EA and TSH, in which the mediating proportion was estimated to be 10.38%. After adjusting for smoking in the multivariable MR analysis, the β value of EA on TSH was attenuated to 0.030 (95% CI, 0.016-0.045; P = 9.32 × 10-3). Multivariable logistic regression model in NHANES suggested a dose-response relationship between TSH (quartile [Q]4 vs Q1: odds ratio = 1.33; 95% CI, 1.05-1.68; P for trend = .023) and EA. Smoking, systolic blood pressure, and body mass index partially mediated the association between EA and TSH, with the proportion of the mediation effects being 43.82%, 12.28%, and 6.81%, respectively. CONCLUSION There is a potentially causal association between EA and TSH, which could be mediated by several risk factors, such as smoking.
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Wang X, Liu X, Li Y, Tang M, Meng X, Chai Y, Zhang L, Zhang H. The causal relationship between thyroid function, autoimune thyroid dysfunction and lung cancer: a mendelian randomization study. BMC Pulm Med 2023; 23:338. [PMID: 37697335 PMCID: PMC10494366 DOI: 10.1186/s12890-023-02588-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Accepted: 07/30/2023] [Indexed: 09/13/2023] Open
Abstract
BACKGROUND The role of thyroid hormones in cancers has been discussed in observational studies; however, the causal relationship between them remains controversial. METHODS The SNPs associated with hypothyroidism and hyperthyroidism were selected from a FinnGen biobank of 342,499 (190,879 females and 151,620 males) Finnish adult subjects. Data from the Thyroidomics Consortium on 72,167 individuals were used to assess genetically determined thyroid-stimulating hormone (TSH) and free thyroxine (FT4). Lung cancer, lung adenocarcinoma and squamous cell lung cancer GWAS data from the International Lung Cancer Consortium(ILCCO). Six different Mendelian randomization (MR) Methods, including Inverse variance weighted (IVW), MR-Egger, Simple mode, MR-Pleiotropy Residual Sum and Outlier methods (MR-PRESSO), Weighted mode and Weighted median were used to Two-Sample MR analysis. IVW was used as the primary estimate. Sensitivity analyses were examined via four aspects (Cochran's Q-test, MR Egger intercept analysis, Funnel plot and Leave-one-out sensitivity test). RESULTS The OR of hypothyroidism on lung cancer was 0.918 (95% CI, 0.859-0.982; p = 0.013) in MR analysis with IVW method. No evidence for effects of hyperthyroidism, TSH and FT4 on lung cancer risk was found via six MR methods. Meanwhile, there was no evidence for effects of lung cancer on hypothyroidism through six MR methods. Lung adenocarcinoma and squamous cell lung carcinoma were further analyzed on the basis of lung cancer. The OR of hypothyroidism on lung adenocarcinoma was 0.893(95% CI, 0.813-0.981; p = 0.019), the OR of hypothyroidism on squamous cell lung cancer was 0.888(95%CI,0.797-0.990, p = 0.032) in MR analysis with IVW method. CONCLUSION In summary, hypothyroidism genetically had a protective causal association with lung cancer. Furthermore, hypothyroidism had protective effects both on lung adenocarcinoma and squamous cell lung cancer. Further work is needed to elucidate the potential mechanisms.
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Chen WT, Wang MY, Wang HY, Tang M, Zhang K, Zhang GS. Ultrasonography for confirmation of emergency department endotracheal tube placement: a meta-analysis. EUROPEAN REVIEW FOR MEDICAL AND PHARMACOLOGICAL SCIENCES 2023; 27:8384-8396. [PMID: 37782155 DOI: 10.26355/eurrev_202309_33761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 10/03/2023]
Abstract
OBJECTIVE This meta-analysis aimed to summarize the evidence on the use of ultrasonography for confirming endotracheal tube placement in emergency departments. MATERIALS AND METHODS We conducted electronic searches on PubMed, Embase, Web of Science, and Cochrane databases. All databases were searched from their inception until February 2023. We selected studies published in English that used ultrasonography to confirm endotracheal tube placement. Case reports, case series, retrospective studies, cadaveric studies, pediatric studies, animal studies, and conference abstracts were excluded. Two reviewers independently extracted and verified data. Forest plots, hierarchical summary receiver operating characteristic (HSROC) curves, and bivariate random-effects models were used to summarize the test performance characteristics. The Stata statistical software package and Meta-DiSc version 1.4 software were used for statistical analysis. RESULTS A total of 1,772 intubations were analyzed. For the detection of endotracheal tube placement, the estimated pooled sensitivity and specificity were 0.98 (95% CI: 0.97-0.99) and 0.92 (95% CI 0.85-0.95), respectively. The pooled positive and negative likelihood ratios were 11.70 (95% CI: 6.49-21.07) and 0.02 (95% CI: 0.01-0.03), respectively. The diagnostic odds ratio of ultrasonography was 221.13, and the area under the HSROC curve revealed an appropriate accuracy of 0.99. CONCLUSIONS Current evidence supports the use of ultrasonography as a worthwhile alternative for endotracheal tube identification for intubations performed in emergency departments. This method can be used in conjunction with capnography as a preliminary test before final confirmation with capnography.
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Deng J, Li MT, Yang MC, Wen ZM, Li XK, Zhu CY, Wang T, Yan T, Tang M, Pu Y, Zuo HY. Different sedation profiles with ciprofol compared to propofol represented by objective sedation level assessments by BIS and its acute hemodynamic impact in 3 escalated doses of ciprofol and propofol in healthy subjects: a single-center, open-label, randomized, 2-stage, 2-way crossover trial. EUROPEAN REVIEW FOR MEDICAL AND PHARMACOLOGICAL SCIENCES 2023; 27:7914-7923. [PMID: 37750620 DOI: 10.26355/eurrev_202309_33550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 09/27/2023]
Abstract
OBJECTIVE To compare the sedation profiles and the pharmacokinetic, pharmacodynamic and safety characteristics of ciprofol and propofol at 3 escalated dose levels in healthy Chinese male subjects. PATIENTS AND METHODS Eighteen subjects were planned to be enrolled into 3 dose groups in turn: group 1 (ciprofol-0.4 mg/kg vs. propofol-2.0 mg/kg), group 2 (ciprofol-0.6 mg/kg vs. propofol-3.0 mg/kg) and group 3 (ciprofol-0.8 mg/kg vs. propofol-4.0 mg/kg). They were randomly assigned into a ciprofol or propofol group in a ratio of 1:1, with sequences of ciprofol-propofol or propofol-ciprofol, separated with a washout period of at least 48 h. RESULTS A total of 19 subjects were enrolled and 18 completed the trial. The median time to being fully alert after induction by ciprofol was longer than for propofol. The bispectral index (BIS) recovered significantly slower with ciprofol than with propofol 5 min and 10 min after reaching its lowest points. Systolic blood pressure (group 1: p=0.041; group 2: p=0.015; group 3: p=0.004) and mean arterial pressures (group 1: p=0.026; group 2: p=0.015; group 3: p=0.004) measured by the area under the curve below the baseline during the 2 min after induction were significantly less for ciprofol compared to propofol, but a significant change in diastolic blood pressure was only observed in group 3 (p=0.002). Eighteen (100.0%) subjects experienced 47 ciprofol-related treatment emergent adverse events (TEAEs) and 17 (94.4%) subjects had 54 propofol-related TEAEs, which were mainly hypotension, involuntary movements, respiratory depression, and pain at the injection site with severity of grade 1 or 2. CONCLUSIONS Ciprofol may be well tolerated at higher doses in the clinical practice and exhibited significantly different sedation profiles to propofol.
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Tang M, Ip WCT, Yuen JKY, Shea YF. Chronic prostatitis with recurrent extended-spectrum beta-lactamase-producing Escherichia coli bacteremia treated with prolonged fosfomycin. Hong Kong Med J 2023. [PMID: 37442588 DOI: 10.12809/hkmjxxxxxxx] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/15/2023] Open
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Tang M, Ip WCT, Yuen JKY, Shea YF. Chronic prostatitis with recurrent extended-spectrum beta-lactamase-producing Escherichia coli bacteremia treated with prolonged fosfomycin. Hong Kong Med J 2023. [PMID: 37442588 DOI: 10.12809/hkmj2210313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/24/2023] Open
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Walker M, Carpino M, Lightfoot D, Rossi E, Tang M, Mann R, Saarela O, Cusimano MD. The effect of recreational cannabis legalization and commercialization on substance use, mental health, and injury: a systematic review. Public Health 2023; 221:87-96. [PMID: 37429043 DOI: 10.1016/j.puhe.2023.06.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 05/29/2023] [Accepted: 06/08/2023] [Indexed: 07/12/2023]
Abstract
OBJECTIVE To determine the effect of recreational cannabis legalization (RCL) and/or recreational cannabis commercialization (RCC) on emergency department (ED) visits, hospitalizations, and deaths due to substance use, injury, and mental health among those aged 11 years and older. METHODS A systematic review of six electronic databases up to February 1, 2023. Original, peer-reviewed articles with interrupted time series or before and after designs were included. Four independent reviewers screened articles and assessed risk of bias. Outcomes with 'critical' risk of bias were excluded. Protocol registered on PROSPERO (# CRD42021265183). RESULTS After screening and risk of bias assessment, 29 studies were included which examined ED visits or hospitalizations for cannabis use or alcohol (N = 10), opioid mortality (N = 3), motor vehicle fatalities or injury (N = 11), and intentional injury/mental health (N = 5). Rates or number of cannabis-related hospitalizations increased after RCL in Canada and the USA. Immediate increases in rates of cannabis-related ED visits were found after both RCL and RCC in Canada. Rates of traffic fatalities increased after RCL and RCC in certain jurisdictions in the USA. CONCLUSIONS RCL was associated with increased rates of cannabis-related hospitalizations. RCL and/or RCC was associated with increased rates of cannabis-related ED visits, consistently shown across sex and age groups. The effect on fatal motor vehicle incidents was mixed, with observed increases found after RCL and/or RCC. The effect of RCL or RCC on opioids, alcohol, intentional injury, and mental health is not clear. These results inform population health initiatives and international jurisdictions considering RCL implementation.
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Yang M, Zhang Q, Ge Y, Tang M, Hu C, Wang Z, Zhang X, Song M, Ruan G, Zhang X, Liu T, Xie H, Zhang H, Zhang K, Li Q, Li X, Liu X, Lin S, Shi H. Prognostic Roles Of Inflammation- And Nutrition-Based Indicators For Female Patients With Cancer. Clin Nutr ESPEN 2023. [DOI: 10.1016/j.clnesp.2022.09.076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/28/2023]
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Liu X, Yuan J, Zhou H, Wang Y, Tian G, Liu X, Wang X, Tang M, Meng X, Kou C, Yang Q, Li J, Zhang L, Ji J, Zhang H. Association Between Systemic Lupus Erythematosus and Primary Hypothyroidism: Evidence from Complementary Genetic Methods. J Clin Endocrinol Metab 2023; 108:941-949. [PMID: 36263677 DOI: 10.1210/clinem/dgac614] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 10/15/2022] [Indexed: 11/19/2022]
Abstract
INTRODUCTION Systemic lupus erythematosus (SLE) and hypothyroidism often coexist in observational studies; however, the causal relationship between them remains controversial. METHODS Complementary genetic approaches, including genetic correlation, Mendelian randomization (MR), and colocalization analysis, were conducted to assess the potential causal association between SLE and primary hypothyroidism using summary statistics from large-scale genome-wide association studies. The association between SLE and thyroid-stimulating hormone (TSH) was further analyzed to help interpret the findings. In addition, findings were verified using a validation data set, as well as through different MR methods with different model assumptions. RESULTS The linkage disequilibrium score regression revealed a shared genetic structure between SLE and primary hypothyroidism, with the significant genetic correlation estimated to be 0.2488 (P = 6.00 × 10-4). MR analysis with the inverse variance weighted method demonstrated a bidirectional causal relationship between SLE and primary hypothyroidism. The odds ratio (OR) of SLE on primary hypothyroidism was 1.037 (95% CI, 1.013-1.061; P = 2.00 × 10-3) and that of primary hypothyroidism on SLE was 1.359 (95% CI, 1.217-1.520; P < 0.001). The OR of SLE on TSH was 1.007 (95% CI, 1.001-1.013; P = 0.032). However, TSH was not causally associated with SLE (P = 0.152). Similar results were found using different MR methods. In addition, colocalization analysis suggested that shared causal variants existed between SLE and primary hypothyroidism. The results of the validation analysis indicated a bidirectional causal relationship between SLE and primary hypothyroidism, as well as shared loci. CONCLUSION In summary, a bidirectional causal relationship between SLE and primary hypothyroidism was observed with complementary genetic approaches.
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Zhang L, Zhang W, Wu X, Cui H, Yan P, Yang C, Zhao X, Xiao J, Xiao C, Tang M, Wang Y, Chen L, Liu Y, Zou Y, Zhang L, Yang Y, Yao Y, Li J, Liu Z, Yang C, Zhang B, Jiang X. A sex- and site-specific relationship between body mass index and osteoarthritis: evidence from observational and genetic analyses. Osteoarthritis Cartilage 2023; 31:819-828. [PMID: 36889626 DOI: 10.1016/j.joca.2023.02.073] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Revised: 02/18/2023] [Accepted: 02/22/2023] [Indexed: 03/10/2023]
Abstract
OBJECTIVE We primarily aimed to investigate whether there are phenotypic and genetic links underlying body mass index (BMI) and overall osteoarthritis (OA). We then intended to explore whether the relationships differ across sexes and sites. METHOD We first evaluated the phenotypic association between BMI and overall OA using data from the UK Biobank. We then investigated the genetic relationship leveraging summary statistics of the hitherto largest genome-wide association studies performed for BMI and overall OA. Finally, we repeated all analyses in a sex- (female, male) and site- (knee, hip, spine) specific manner. RESULTS Observational analysis suggested an increased hazard of diagnosed OA per 5 kg/m2 increment in BMI (hazard ratio = 1.38, 95% confidence interval (CI) = 1.37-1.39). A positive overall genetic correlation was observed for BMI and OA (rg = 0.43, P = 4.72 × 10-133), corroborated by 11 significant local signals. Cross-trait meta-analysis identified 34 pleiotropic loci shared between BMI and OA, of which seven were novel. Transcriptome-wide association study revealed 29 shared gene-tissue pairs, targeting nervous, digestive, and exo/endocrine systems. Mendelian randomization demonstrated a robust BMI-OA causal relationship (odds ratio = 1.47, 95% CI = 1.42-1.52). A similar pattern of effects was observed in sex- and site-specific analyses, with BMI affecting OA comparably in both sexes and most strongly in the knee. CONCLUSION Our work demonstrates an intrinsic relationship underlying BMI and overall OA, reflected by a pronounced phenotypic association, significant biological pleiotropy, and a putative causal link. Stratified analysis further reveals that the effects are distinct across sites and comparable across sexes.
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Zhu MM, Ma Y, Tang M, Pan L, Liu WL. Hypoxia-induced upregulation of matrix metalloproteinase 9 increases basement membrane degradation by downregulating collagen type IV alpha 1 chain. Physiol Res 2022. [DOI: 10.33549/physiolres.934930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Hypoxia can cause basement membrane (BM) degradation in tissues. Matrix metalloproteinase 9 (MMP-9) is involved in various human cancers as well as BM degradation by downregulating type IV collagen (COL4). This study investigated the role of MMP-9 in hypoxia-mediated BM degradation in rat bone marrow based on its regulation of collagen type IV alpha 1 chain (COL4A1). Eighty male rats were randomly divided into four groups based on exposure to hypoxic conditions at a simulated altitude of 7,000 m, control (normoxia) and 3, 7, and 10 days of hypoxia exposure. BM degradation in bone marrow was determined by transmission electron microscopy. MMP-9 levels were assessed by western blot and real-time PCR, and COL4A1 levels were assessed by western blot and immunohistochemistry. Microvessels BMs in bone marrow exposed to acute hypoxia were observed by electron microscopy. MMP-9 expression increased, COL4A1 protein expression decreased, and BM degradation occurred in the 10-, 7-, and 3-day hypoxia groups compared with that in the control group (all P < 0.05). Hypoxia increased MMP-9 levels, which in turn downregulated COL4A1, thereby increasing BM degradation. MMP-9 upregulation significantly promoted BM degradation and COL4A1 downregulation. Our results suggest that MMP-9 is related to acute hypoxia-induced BM degradation in bone marrow by regulating COL4A1.
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Abdelmonem M, Dussaq A, Cai W, Tang M, Nguyen A, Papakonstantino K, Cabungan M, Yoshizuka S, Hollenhorst M. Comparative Sensitivity of Solid-Phase Versus PEG Enhancement Assays for Detection and Identification of Red Blood Cell Antibodies. Am J Clin Pathol 2022. [DOI: 10.1093/ajcp/aqac126.342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Abstract
Introduction/Objective
Identifying antibodies to red blood cell (RBC) antigens is one of transfusion medicine’s most critical and challenging issues. There are 354 RBC antigens recognized by the International Society of Blood Transfusion. Accurate identification of clinically significant alloantibodies is imperative for identifying and preventing hemolytic transfusion reactions and hemolytic disease of the fetus and newborn. We compared the performance of the tube (polyethylene glycol–indirect antiglobulin test [PEG-IAT]) and solid-phase techniques for antibody identification.
Methods/Case Report
We performed a retrospective study on all antibody screens and identifications performed between 2007–2021 at Stanford Hospital. Over this period, 631,535 antibody screens were performed predominantly using an automated solid-phase technique. Subsequent antibody identification studies were performed using manual tube testing (PEG-IAT) and automated solid-phase techniques.
Results (if a Case Study enter NA)
Antibody screening resulted in 28,316 (4.5%) positive samples with at least one antibody. Antibody identification performed on both platforms identified 50 discordant [DMH1] samples. 8 anti-Jka, 2 anti-Jkb, 1 anti-S, and 1 anti-M were detected by automatic solid-phase technique but were not detected by PEG-IAT. 20 anti-E, 6 anti-K, 2 anti-Fya, 2 anti-c , 2 anti-C, 2 anti-Fyb, 1 anti-cE[DMH2] , 1 anti-e,1 anti-M, and 1 anti-S were detected by PEG-IAT but were negative by automated solid-phase technique. Anti-E had the least sensitivity (98.99%) in the automated solid-phase technique, while anti-Jkb had the least sensitivity (98.78%) in PEG-IAT.
Conclusion
This is the first robust 15-year study comparing methodologic sensitivity to detect clinically significant alloantibodies. The incidence of discordant results between the PEG-IAT and solid-phase technique was low. Among discordant samples, anti-Jka was commonly detected by solid-phase but not by PEG-IAT. In contrast, anti-E was commonly detected by PEG-IAT but not by the solid phase.
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Abdelmonem M, Cai W, Yunce M, Tang M, Shan H, Cabungan M. Racial Disparity in Antibody Against High Prevalence Antigen; Anti-U. Am J Clin Pathol 2022. [DOI: 10.1093/ajcp/aqac126.105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Abstract
Introduction/Objective
Anti-U is an IgG antibody directed against the U antigen, which usually forms after exposure to U antigen via blood transfusion and/or pregnancy. U antigen is located on glycophorin B (GYPB) as part of the MNS blood group system. Approximately 2% of the African American population lacks this antigen, making them prone to developing anti-U. Anti-U can cause hemolytic disease of fetus and newborn (HDFN) and hemolytic transfusion reactions (HTR).
Methods/Case Report
A 60-year-old African American male underwent aortic valve surgery. The patient was A Pos with a negative antibody screen. During surgery, the patient was transfused with 3 random units of packed red blood cells (PRBCs). The postoperative course was uncomplicated, and the patient was discharged home. 6 months later, the patient was admitted for another procedure and was expected to require blood products. Thus, a type and screen test was ordered, revealing pan reactivity on screening cells. This prompted further investigation. Antibody detection was performed with the solid-phase technique followed by the tube method with Polyethylene glycol (PEG) as an enhancement medium. PEG technique is the next choice of method if the solid phase requires extended antibody work up, which was the case in our patient. PEG tube method successfully identified Anti-U, and the patient's phenotype was confirmed to be U negative.
Results (if a Case Study enter NA)
N/A.
Conclusion
It is imperative to stress the importance of racial disparity while investigating antibodies against high prevalence. In our case, our suspicion was high for Anti-U, given that patient was of African American descent. Tube methods with PEG and Solid Phase techniques are usually used for antibody identification. It is recommended that patients with rare antibodies carry an Antibody ID card indicating the rare antibody they have to prevent further exposure.
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Chen WT, Wang MY, Jiang TT, Tang M, Ye QH, Wang HY, Mo EJ. Transtracheal ultrasound for confirmation of endotracheal tube placement in the intensive care unit: a systematic review and meta-analysis. EUROPEAN REVIEW FOR MEDICAL AND PHARMACOLOGICAL SCIENCES 2022; 26:8224-8233. [PMID: 36459006 DOI: 10.26355/eurrev_202211_30354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
OBJECTIVE The major objective of this review was to compare the diagnostic accuracy of ultrasound in confirming tracheal intubation to the standard methods of confirmation in the intensive care unit (ICU). MATERIALS AND METHODS This systematic review and meta-analysis of observational studies was conducted from inception to July 2022. We included studies that compared the diagnostic accuracy of ultrasound-detected tracheal intubation to that of the gold standard diagnostic technique performed in adult patients who underwent tracheal intubation as part of any procedure. We searched the following electronic databases for published studies: PubMed, EMBASE, Cochrane Central, and Web of Science. Risk of bias was assessed using a standard procedure based on the Quality Assessment of Diagnostic Accuracy Studies-2 criteria. The results were analyzed using the RevMan or Meta-Disc software to determine the adequacy and conclusiveness of the available evidence. RESULTS Five studies that included 344 patients met the inclusion criteria. Pooled sensitivity was 0.96 (95% confidence interval (CI) (0.92-0.98) and 1.00 (95% CI: 0.97-1.00), respectively. Furthermore, the diagnostic odds ratio of ultrasonography was 311.25 (95% CI: 63.77-1,519.22), which was confirmed by a summary receiver operating characteristic curve with an area under the curve of 0.98. CONCLUSIONS Ultrasonography has high sensitivity and specificity, is a valuable adjunct for confirming tracheal intubation in the ICU and should be performed when capnography is unavailable or unreliable.
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Rasalingam Moerk S, Kristensen LQ, Osterlund LG, Christensen S, Tang M, Terkelsen CJ, Eiskjaer H. Long-term neurological intact survival and quality of life after refractory out-of-hospital cardiac arrest treated with rescue mechanical circulatory support. Eur Heart J 2022. [DOI: 10.1093/eurheartj/ehac544.1512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
Background
Mechanical circulatory support (MCS) with either veno-arterial extracorporeal membrane oxygenation (V-A ECMO) or Impella has emerged as a rescue therapy for refractory out-of-hospital cardiac arrest (OHCA). However, only short-term outcome is specified and most studies do not report follow-up beyond six months. Long-term survival and quality of life in this high-risk population remains unknown.
Purpose
To determine long-term neurological intact survival and quality of life in patients with refractory OHCA treated with MCS.
Methods
This was an observational, single-centre study of OHCA-patients from January 2015 to December 2019. Patients treated with MCS for OHCA were compared with patients receiving conventional cardiopulmonary resuscitation (CPR). A follow-up of long-term survivors in the MCS group was conducted (>1 year after arrest). This included health related quality of life questionaries (Short Form-36 [SF-36]) and assessment of neurological function with Cerebral Performance Category (CPC). Good neurological outcome was defined as CPC 1 and CPC 2.
Results
A total of 1015 with OHCA were included; 101 received MCS for refractory cardiac arrest. Among these V-A ECMO was deployed in 97 patients and Impella in 4 patients. The MCS group had significantly longer low-flow times compared to the conventional group (105 [IQR, 94–123] minutes versus 18 [IQR 10–39] minutes) and were more metabolically deranged upon arrival at hospital (Table 1). In patients receiving MCS, the hospital discharge rate was 27% and good neurological outcome was seen in 93% among patients discharged. At follow-up, 15 out of 21 long-term survivors participated. Median follow-up time was 4.8±1.6 (range 2.8–6.1 years). Mean age at follow-up was 61±7.3 years, 11 (73%) were men. Neurological outcome with CPC 1 was found in 12 patients (80%), with CPC 2 in 2 patients (13%), and with CPC 3 in 1 patient (7%). Two had improved neurological status from CPC 2 to CPC 1 since discharge. Mean scores of the SF-36 revealed an overall high level of psychical and mental health in long-term survivors (Figure 1).
Conclusion
Long-term survival with good neurological outcome was high in patients with refractory OHCA treated with MCS despite prolonged resuscitation and severe metabolic derangement. These patients may expect a reasonable quality of life after discharge.
Funding Acknowledgement
Type of funding sources: Public hospital(s). Main funding source(s): Department of Cardiology, Aarhus University HospitalSnedkermester Sophus Jacobsen og hustru Astrid Jacobsens Fond
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Lin XY, Chen WT, Wang HY, Ye QH, Tang M. A new method for diagnosis of tracheoesophageal fistula. EUROPEAN REVIEW FOR MEDICAL AND PHARMACOLOGICAL SCIENCES 2022; 26:6894-6895. [PMID: 36263567 DOI: 10.26355/eurrev_202210_29868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
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Chen WT, Wang HY, Ye QH, Tang M, Wang YW. The diagnostic values of lung ultrasound for ARDS. EUROPEAN REVIEW FOR MEDICAL AND PHARMACOLOGICAL SCIENCES 2022; 26:6642-6646. [PMID: 36196714 DOI: 10.26355/eurrev_202209_29764] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
OBJECTIVE Acute respiratory distress syndrome (ARDS) is a critical disease commonly found in many clinical cases, with a mortality rate of approximately 50%. Early diagnosis and intervention are important for improving ARDS prognosis. In this study, the applications of lung ultrasound in ARDS diagnosis and assessment are reviewed to clarify its key clinical values and application prospects. MATERIALS AND METHODS According to the standard diagnosis of ARDS based on the Berlin definition, CXR or CT examination should be conducted. However, both the blurred images of the former, as well as the inconvenience and high risks of the latter, impose restrictions on their application in critically ill patients. RESULTS Lung ultrasound was shown to improve safety, effectiveness, lacked radiation, can be performed bedside, and offers dynamic functionality. CONCLUSIONS It may be a suitable approach to replace or complement traditional imaging examinations with lung ultrasound.
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Peng J, Tang M, Liu LL, Chen WT, Ye QH. Diagnostic accuracy of ultrasonography for detecting gastric tube placement: an updated meta-analysis. EUROPEAN REVIEW FOR MEDICAL AND PHARMACOLOGICAL SCIENCES 2022; 26:6328-6339. [PMID: 36111934 DOI: 10.26355/eurrev_202209_29657] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
OBJECTIVE This study aimed at reviewing the diagnostic accuracy of ultrasonography for detecting correct nasogastric tube placement compared with X-ray imaging as the reference standard. MATERIALS AND METHODS This was a systematic review and meta-analysis of observational studies published between 1961 and 2022. We included studies that compared the diagnostic accuracy of ultrasound detection for nasogastric tube placement with that of X-ray imaging in adult patients who were undergoing nasogastric tube placement for any reason. We searched for published studies in the following electronic databases: Cochrane Library, PubMed, EMBASE, and Web of Science. The risk of bias was assessed using a standard procedure according to the Quality Assessment of Diagnostic Accuracy Studies-2 criteria. The results were analyzed using RevMan or Meta-Disc software to determine the adequacy and conclusiveness of the available evidence. RESULTS Fourteen studies met our inclusion criteria. Overall, 1,812 patients were included in these studies. The results included a pooled sensitivity of 0.96 (95% confidence interval [CI] 0.94-0.97), specificity of 0.91 (95% CI 0.85-0.96), positive likelihood ratio of 5.08 (95% CI 1.49-17.39), and negative likelihood ratio of 0.08 (95% CI 0.06-0.10). This was confirmed through a summary receiver operating characteristic curve, which showed that the area under the curve was 0.96. CONCLUSIONS We found evidence about validity of ultrasound as an efficient method for verifying nasogastric tube placement, although there is insufficient evidence to suggest that it can be used as a diagnostic tool for incorrect gastric tube placement.
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Tang M, Yan X, Gao J, Li L, Zhe X, Zhang X, Jiang F, Hu J, Ma N, Ai K, Zhang X. High-Resolution MRI for Evaluation of the Possibility of Successful Recanalization in Symptomatic Chronic ICA Occlusion: A Retrospective Study. AJNR Am J Neuroradiol 2022; 43:1164-1171. [PMID: 35863780 PMCID: PMC9575431 DOI: 10.3174/ajnr.a7576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Accepted: 05/31/2022] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Accurate radiologic evaluation of the possibility of successful recanalization in symptomatic chronic ICA occlusion remains challenging. This study aimed to investigate the high-resolution MR imaging characteristics of symptomatic chronic ICA occlusion and their association with successful recanalization. MATERIALS AND METHODS Consecutive patients with symptomatic chronic ICA occlusion who underwent balloon dilation plus stent implantation were identified retrospectively and divided into 2 groups: a successful recanalization group and an unsuccessful recanalization group. Clinical and high-resolution MR imaging characteristics were compared between the groups. Univariate and multivariate analyses were used to identify the characteristics associated with successful recanalization. RESULTS A total of 114 patients were included in the study. High-resolution MR imaging characteristics independently associated with unsuccessful recanalization were longer lesion length (OR, 0.41; 95% CI, 0.36-0.55; P = .009) and larger calcification volume (OR, 0.56; 95% CI, 0.37-0.68; P = .002) for proximal occlusion and reversed distal ICA flow at the level of ophthalmic segment or above (OR, 0.14; 95% CI, 0.08-0.48; P = .001). Reversed distal ICA flow at the level of the petrous segment or below (OR, 4.07; 95% CI, 1.65-8.38; P = .001) and lumen area (OR, 1.13; 95% CI, 1.04-1.61; P = .002) for distal occlusion were risk factors of successful recanalization. CONCLUSIONS In symptomatic chronic ICA occlusion, lesion length and calcification volume (for proximal occlusion), the level of reversed distal ICA flow, and the lumen area (for distal occlusion) appear to be predictors of successful recanalization. High-resolution MR imaging can evaluate chronic ICA occlusion and help in clinical decision-making.
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Dai Y, Zhao YW, Ma L, Tang M, Qiu XP, Liu Y, Yuan Z, Zhou SM. Fourfold Anisotropic Magnetoresistance of L1_{0} FePt Due to Relaxation Time Anisotropy. PHYSICAL REVIEW LETTERS 2022; 128:247202. [PMID: 35776447 DOI: 10.1103/physrevlett.128.247202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 04/06/2022] [Accepted: 05/25/2022] [Indexed: 06/15/2023]
Abstract
Experimental measurements show that the angular dependence of the anisotropic magnetoresistance (AMR) in L1_{0} ordered FePt epitaxial films on the current orientation and magnetization direction is a superposition of the corresponding dependences of twofold and fourfold symmetries. The twofold AMR exhibits a strong dependence on the current orientation, whereas the fourfold term only depends on the magnetization direction in the crystal and is independent of the current orientation. First-principles calculations reveal that the fourfold AMR arises from the relaxation time anisotropy due to the variation of the density of states near the Fermi energy under rotation of the magnetization. This relaxation time anisotropy is a universal property in ferromagnetic metals and determines other anisotropic physical properties that are observable in experiment.
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