Clinicopathological significance of microsatellite instability and immune escape mechanism in patients with gastric solid-type poorly differentiated adenocarcinoma.

BACKGROUND: In gastric solid-type poorly differentiated adenocarcinoma (PDA), the role of microsatellite instability and immune escape mechanism remains unclear. The current study aimed to elucidate the clinical significance of mismatch repair (MMR) status, genome profile, C-X-C motif chemokine receptor 2 (CXCR2) expression, and myeloid-derived suppressor cell (MDSC) infiltration in solid-type PDA. METHODS: In total, 102 primary solid-type PDA cases were retrieved, and classified into 46 deficient-MMR (dMMR) and 56 proficient-MMR (pMMR) cases based on immunohistochemistry (IHC) and polymerase chain reaction-based molecular testing results. The mRNA expression profiles (NanoString nCounter Assay) of stage-matched dMMR (n = 6) and pMMR (n = 6) cases were examined. The CXCR2 expression and MDSC infiltration (CD11b- and CD33-positive cells) were investigated via IHC in all solid-type PDA cases. RESULTS: mRNA analysis revealed several differentially expressed genes and differences in biological behavior between the dMMR (n = 46) and pMMR (n = 56) groups. In the multivariate analysis, the dMMR status was significantly associated with a longer disease-free survival (hazard ratio = 5.152, p = 0.002) and overall survival (OS) (hazard ratio = 5.050, p = 0.005). CXCR2-high expression was significantly correlated with a shorter OS in the dMMR group (p = 0.018). A high infiltration of CD11b- and CD33-positive cells was significantly correlated with a shorter OS in the pMMR group (p = 0.022, 0.016, respectively). CONCLUSIONS: dMMR status can be a useful prognostic predictor, and CXCR2 and MDSCs can be novel therapeutic targets in patients with solid-type PDA.

Importance of preoperative total colonoscopy and endoscopic resection after self-expandable metallic stent placement for obstructive colorectal cancer as a bridge-to-surgery.

BACKGROUND AND AIM: Colonic self-expandable metallic stent (SEMS) placement enables preoperative total colonoscopy (TCS) in patients with obstructive colorectal cancer. Following SEMS placement, it is possible to assess the presence or absence of synchronous proximal colon cancers and perform preoperative endoscopic resection (ER) for neoplastic lesions proximal to the primary lesion. The objective of this study was to determine the usefulness and safety of preoperative TCS and ER after SEMS placement in patients with obstructive colorectal cancer. METHODS: From April 2016 to March 2022, we enrolled 100 patients with obstructive colorectal cancer who underwent SEMS placement, including 86 patients who underwent preoperative TCS after SEMS placement. Complications associated with preoperative TCS and ER after SEMS placement and the characteristics of the neoplastic lesions were assessed. RESULTS: The success rate of SEMS placement as bridge-to-surgery was 98.0%; six patients had associated complications. Preoperative TCS was performed 8 (range: 1-30) days after SEMS placement. Four patients had synchronous advanced cancers. Nine non-advanced synchronous cancers, 116 adenomas, and 18 sessile-serrated lesions were treated by preoperative TCS and ER after SEMS placement. No procedure-related complications, namely stent migration, bleeding, and perforation were observed. Forty-five patients underwent follow-up TCS 1 year after surgery. Only one patient with submucosal invasive cancer required a second surgery. CONCLUSIONS: Preoperative TCS and ER after SEMS placement was performed with no complications. This approach allows preoperative evaluation of the entire colon and the treatment of precancerous lesions. (240 words).

Epitaxy and transport properties of alkali-earth palladate thin films.

Topological insulators and semimetals are an interesting class of materials for new electronic and optical applications owing to their characteristic electromagnetic responses originating from the spin-orbit coupled band structures. However, topological electronic structures are rare in oxide materials despite their chemical stability being preferable for applications. In this study, given the theoretical prediction of Dirac bands in CaPd3O4, we investigate the fabrication and transport properties of SrPd3O4 and CaPd3O4 thin films as candidates of oxide Dirac semimetals. We have found that these materials are epitaxially grown on MgO (100) substrate under limited growth conditions by pulsed laser deposition. The transport properties show a weak temperature dependence, suggestive of narrow-gap properties, although unintentionally doped holes hinder us from revealing the presence of the Dirac band. Our study establishes the basic thermodynamics of thin-film fabrication of these materials and will lead to interesting properties characteristic of topological band structure by modulating the electronic structure by, for example, chemical substitutions or pressure.

Soft-Magnetic Skyrmions Induced by Surface-State Coupling in an Intrinsic Ferromagnetic Topological Insulator Sandwich Structure.

A magnetic skyrmion induced on a ferromagnetic topological insulator (TI) is a real-space manifestation of the chiral spin texture in the momentum space and can be a carrier for information processing by manipulating it in tailored structures. Here, a sandwich structure containing two layers of a self-assembled ferromagnetic septuple-layer TI, Mn(Bi1-xSbx)2Te4 (MnBST), separated by quintuple layers of TI, (Bi1-xSbx)2Te3 (BST), is fabricated and skyrmions are observed through the topological Hall effect in an intrinsic magnetic topological insulator for the first time. The thickness of BST spacer layer is crucial in controlling the coupling between the gapped topological surface states in the two MnBST layers to stabilize the skyrmion formation. The homogeneous, highly ordered arrangement of the Mn atoms in the septuple-layer MnBST leads to a strong exchange interaction therein, which makes the skyrmions "soft magnetic". This would open an avenue toward a topologically robust rewritable magnetic memory.

Most frequently asked questions about the coercivity of Nd-Fe-B permanent magnets.

Physically, the coercivity of permanent magnets should scale with the anisotropy field of ferromagnetic compounds, H A; however, the typical coercivity values of commercial polycrystalline sintered magnets are only ~0.2 H A, which is known as Brown's paradox. Recent advances in multi-scale microstructure characterizations using focused ion beam scanning electron microscope (FIB/SEM), aberration corrected scanning transmission electron microscopy (Cs-corrected STEM), and atom probe tomography (APT) revealed detailed microstructural features of commercial and experimental Nd-Fe-B magnets. These investigations suggest the magnetism of a thin layer formed along grain boundaries (intergranular phase) is a critical factor that influences the coercivity of polycrystalline magnets. To determine the magnetism of the thin intergranular phase, soft X-ray magnetic circular dichroism and electron holography play critical roles. Large-scale micromagnetic simulations using the models that are close to real microstructure incorporating the recent microstructure characterization results gave insights on how the coercivity and its thermal stability is influenced by the microstructures. Based on these new findings, coercivity of Nd-Fe-B magnets is being improved to its limit. This review replies to the most frequently asked questions about the coercivity of Nd-Fe-B permanent magnets based on our recent studies.

Predictive Materials Design of Magnetic Random-Access Memory Based on Nanoscale Atomic Structure and Element Distribution.

Magnetic tunnel junctions (MTJs) capable of electrical read and write operations have emerged as a canonical building block for nonvolatile memory and logic. However, the cause of the widespread device properties found experimentally in various MTJ stacks, including tunneling magnetoresistance (TMR), perpendicular magnetic anisotropy (PMA), and voltage-controlled magnetic anisotropy (VCMA), remains elusive. Here, using high-resolution transmission electron microscopy and energy-dispersive X-ray spectroscopy, we found that the MTJ crystallization quality, boron diffusion out of the CoFeB fixed layer, and minimal oxidation of the fixed layer correlate with the TMR. As with the CoFeB free layer, seed layer diffusion into the free layer/MgO interface is negatively correlated with the interfacial PMA, whereas the metal-oxides concentrations in the free layer correlate with the VCMA. Combined with formation enthalpy and thermal diffusion analysis that can explain the evolution of element distribution from MTJ stack designs and annealing temperatures, we further established a predictive materials design framework to guide the complex design space explorations for high-performance MTJs. On the basis of this framework, we demonstrate experimentally high PMA and VCMA values of 1.74 mJ/m2 and 115 fJ/V·m-1 with annealing stability above 400 °C.

The Altered Mucosal Barrier Function in the Duodenum Plays a Role in the Pathogenesis of Functional Dyspepsia.

BACKGROUND: An altered gastrointestinal barrier function is reportedly associated with the pathogenesis of functional dyspepsia (FD); however, the pathogenesis of FD has not yet been fully elucidated. AIMS: The objective of the present study was to determine whether the mucosal barrier function is impaired in patients with FD and to investigate the mechanisms underlying FD. METHODS: The present study included patients with FD (FD group, n = 24), non-FD patients with abdominal symptoms (symptomatic control group, n = 14), and patients with no abdominal symptoms (asymptomatic control group, n = 20). The groups were compared regarding the mucosal electrical impedance (MI) values of the stomach and duodenum, which were measured using a tissue conductance meter during esophagogastroduodenoscopy. RESULTS: There were no significant differences between the three groups in the MI of the stomach. In contrast, the duodenal MI of the FD group (17.8 ± 4.3 Ω) was significantly lower than those of the symptomatic control group (27.2 ± 6.4 Ω, p < 0.0001) and asymptomatic control group (23.0 ± 7.4 Ω, p = 0.016). The expression of zonula occludens-1 (ZO-1) was significantly lower in the FD group than in the symptomatic control group (p = 0.011), where ZO-1 was positively correlated with the duodenal MI (ß = 0.513, p = 0.017). The interleukin (IL)-1ß expression was significantly higher in the FD group than in the symptomatic control group (p = 0.041), where IL-1ß was inversely correlated with the duodenal MI (ß = - 0.600, p = 0.004). CONCLUSIONS: The mucosal barrier function of the duodenum was altered in patients with FD. Both a decreased ZO-1 and increased IL-1ß may play a role in the pathogenesis of FD.

Direct-Contact Seebeck-Driven Transverse Magneto-Thermoelectric Generation in Magnetic/Thermoelectric Bilayers.

Transverse thermoelectric generation converts temperature gradient in one direction into an electric field perpendicular to that direction and is expected to be a promising alternative in creating simple-structured thermoelectric modules that can avoid the challenging problems facing traditional Seebeck-effect-based modules. Recently, large transverse thermopower has been observed in closed circuits consisting of magnetic and thermoelectric materials, called the Seebeck-driven transverse magneto-thermoelectric generation (STTG). However, the closed-circuit structure complicates its broad applications. Here, STTG is realized in the simplest way to combine magnetic and thermoelectric materials, namely, by stacking a magnetic layer and a thermoelectric layer together to form a bilayer. The transverse thermopower is predicted to vary with changing layer thicknesses and peaks at a much larger value under an optimal thickness ratio. This behavior is verified in the experiment, through a series of samples prepared by depositing Fe-Ga alloy thin films of various thicknesses onto n-type Si substrates. The measured transverse thermopower reaches 15.2 ± 0.4 µV K-1, which is a fivefold increase from that of Fe-Ga alloy and much larger than the current room temperature record observed in Weyl semimetal Co2MnGa. The findings highlight the potential of combining magnetic and thermoelectric materials for transverse thermoelectric applications.

Combined effect of interstitial-substitutional elements on dislocation dynamics in nitrogen-added austenitic stainless steels.

Combined addition of interstitial-substitutional elements has been acknowledged to contribute to the increase in the strengths of steels. For further improvements in mechanical properties, their atomic-scale interaction mechanisms with dislocations are required to be examined. In this study, both high-resolution transmission electron microscopy and atom-probe tomography were used to correlate interstitial-substitutional elements with dislocation characteristics in austenitic stainless steels. Three types of dislocation core structures are identified and associated with their strain fields as well as N and Cr atoms in the N-added steels. It is revealed that N atoms interact elastically with the dislocations, followed by the segregation of Cr atoms via the chemical interaction between N and Cr atoms. This insight significantly improves the understanding of the multiple alloying mechanism in metallic materials such as interstitial alloys and high-entropy alloys.

Noise reduction of electron holography observations for a thin-foiled Nd-Fe-B specimen using the wavelet hidden Markov model.

In this study, we investigate the effectiveness of noise reduction in electron holography, based on the wavelet hidden Markov model (WHMM), which allows the reasonable separation of weak signals from noise. Electron holography observations from a Nd2Fe14B thin foil showed that the noise reduction method suppressed artificial phase discontinuities generated by phase retrieval. From the peak signal-to-noise ratio, it was seen that the impact of denoising was significant for observations with a narrow spacing of interference fringes, which is a key parameter for the spatial resolution of electron holography. These results provide essential information for improving the precision of electron holography studies.

The interplay between alterations in esophageal microbiota associated with Th17 immune response and impaired LC20 phosphorylation in achalasia.

BACKGROUND: Achalasia is an esophageal motility disorder with an unknown etiology. We aimed to determine the pathogenesis of achalasia by studying alterations in esophageal smooth muscle contraction and the associated inflammatory response, and evaluate the role of esophageal microbiota in achalasia development. METHODS: We analyzed esophageal mucosa and lower esophageal sphincter (LES) samples, obtained from patients with type II achalasia who underwent peroral endoscopic myotomy. Esophageal conditioned media obtained from patients were transferred into the mouse esophagus to determine whether the esophageal intraluminal environment is associated with achalasia. RESULTS: Approximately 30% of 20-kDa myosin light chains (LC20) was phosphorylated in LES from the control group under resting and stimulated conditions, whereas less than 10% of LC20 phosphorylation was detected in achalasia under all conditions. The hypophosphorylation of LC20 in achalasia was associated with the downregulation of the myosin phosphatase-inhibitor protein CPI-17. Th17-related cytokines, including IL-17A, IL-17F, IL-22, and IL-23A, were significantly upregulated in achalasia. α-Diversity index of esophageal microbiota and the proportion of several microbes, including Actinomyces and Dialister, increased in achalasia. Actinomyces levels positively correlated with IL-23A levels, whereas Dialister levels were positively associated with IL-17A, IL-17F, and IL-22 levels. Esophageal IL-17F levels increased in mice after oral administration of the conditioned media. CONCLUSIONS: In LES of patients with achalasia, hypophosphorylation of LC20, a possible cause of impaired contractility, was associated with CPI-17 downregulation and an increased Th17-related immune response. The esophageal intraluminal environment, represented by the esophageal microbiota, could be associated with the development and exacerbation of achalasia.

Lung squamous cell carcinoma arising in a patient with adult-onset recurrent respiratory papillomatosis.

A 75-year-old male was admitted to our hospital in December 2011 with a mass in the right upper pulmonary lobe. He was incidentally diagnosed as having tracheal papillomas 10 years ago. Bronchoscopy revealed multiple polypoid papillomas in the dorsal lesion of the trachea. Polymerase chain reaction amplification detected human papillomavirus type 11 DNA in the papilloma tissues. A computed tomography scan demonstrated the occlusion of the right superior segment bronchus with distal consolidation. Furthermore, F-18 fluoro-2-deoxy-D-glucose positron emission tomography and computed tomography showed intense tracer uptake in the right superior segment of the lung. He underwent a right upper lobectomy. The tumor was seen as a rounded nodule, ≈ 2 cm in diameter. Histological examination of the tumor revealed squamous papilloma with papillary and solid architecture surrounded by accumulation of acute inflammatory cells. Furthermore, in a part of the tumor, squamous cell carcinoma was also present. The lymph nodes were free of tumor. After the surgery, he continued to undergo endoscopic microwave resection. Recurrent respiratory papillomatosis is a rare disease that can cause life-threatening airway compromise and malignant transformation. The present case indicates that F-18 fluoro-2-deoxy-D-glucose positron emission tomography and computed tomography is indispensable for early detection of lung cancer arising in a patient with recurrent respiratory papillomatosis.

Extraction of phase information approximating the demagnetization field within a thin-foiled magnet using electron holography observation.

This paper proposes a method that provides a phase image related to the demagnetization field (Hd) within a thin-foil permanent magnet using electron holography. The observation of Hd remains a significant challenge because electron holography in principle allows only imaging of the magnetic flux density (B), which is a mixture of the contributions from magnetization (M), stray magnetic field (Hs) outside of the specimen and Hd inside of the specimen. The phase map approximating Hd, which was determined by processing of the electron holography observation from a Nd2Fe14B single-crystalline specimen, showed a good agreement with the prediction by micromagnetic theory. With respect to permanent magnets, this method can be applied to examinations about the coercivity mechanism, which is sensitive to the demagnetization field. Graphical Abstract.

Tumor progression by epithelial-mesenchymal transition in ARID1A- and SMARCA4-aberrant solid-type poorly differentiated gastric adenocarcinoma.

Solid-type poorly differentiated adenocarcinoma (PDA) of the stomach is frequently associated with microsatellite instability (MSI) and aberrations of the SWI/SNF chromatin remodeling complex. Previous studies showed that aberrant ARID1A and SMARCA4 expression induces mesenchymal transition. We analyzed 51 primary-site cases and 209 metastatic lymph nodes among solid-type PDA for the expression of SWI/SNF complex subunits (ARID1A, SMARCA4, SMARCB1, SMARCC2) and epithelial-mesenchymal transition (EMT) markers (E-cadherin, ß-catenin, Snail). We also analyzed 40 cases of non-solid-type PDA as a stage-matched control group. Aberrant expression of ARID1A (39%) and SMARCA4 (49%) was more common in solid-type PDA than in non-solid-type PDA (ARID1A, P = 0.0049; SMARCA4, P < 0.0001). The group of solid-type PDA with aberrant ARID1A showed significantly longer overall and progression-free survival than the corresponding ARID1A-retained group (P = 0.0405 and P = 0.0296, respectively). Aberrant expression of EMT factors inducing mesenchymal transition in the groups with solid-type PDA at the primary site or metastatic lymph nodes with aberrant ARID1A was less common than in the corresponding groups with retained ARID1A (E-cadherin, primary site P = 0.0341, lymph node P < 0.0001; ß-catenin, primary site P = 0.0293, lymph node P = 0.0010; Snail, primary site P = 0.0169, lymph node P = 0.0828). Furthermore, N3 of the TNM classification was more frequently observed in the group with solid-type PDA with retained ARID1A than in the corresponding ARID1A-aberrant group (P = 0.0288). Mesenchymal transition was not induced in the ARID1A-aberrant group, in which patients had favorable prognosis, and preserved epithelial characteristics in EMT may play an important role in low tumor aggressiveness of solid-type PDA.

Solid-type poorly differentiated adenocarcinoma of the stomach: A characteristic morphology reveals a distinctive immunoregulatory tumor microenvironment.

Solid-type poorly differentiated adenocarcinoma (solid-type-PDA) of the stomach is a unique histological subtype of "tubular adenocarcinoma", but little is known about its clinicopathological features, molecular pathological characteristics and immunoregulatory tumor microenvironment. Herein, we examined the immunohistochemical expressions of mismatch repair (MMR) proteins (MLH1, PMS2, MSH2, MSH6) in 57 cases of solid-type-PDA and classified them as either MMR-deficient or -proficient (dMMR, N = 23; pMMR, N = 34), and additionally identified 18 dMMR-well-differentiated adenocarcinoma (WDA) and 34 pMMR-WDA as control groups. We analyzed and compared solid-type-PDA with WDA by evaluating the immunoexpressions of key immune pathway proteins (programmed death ligand 1 (PD-L1) and indoleamine 2,3-dioxygenase 1 (IDO1)) and tumor-infiltrating lymphocytes (TILs) (CD8, Foxp3 and PD-1). The results reveled IDO1 was significantly more frequent in dMMR-solid-type-PDA than in dMMR-WDA (P = 0.0046). Moreover, dMMR-solid-type-PDA tended to have higher mean CD8+ and Foxp3+ TILs compared with dMMR-WDA [P = 0.0006 (CD8+) and P = 0.1061 (Foxp3+)], and IDO1-positive tended to be associated with a large number of CD8+, Foxp3+ or PD-1+ TILs in almost all tumor subtypes. PD-L1 was significantly observed in 44 % (15/34) of pMMR-solid-type-PDA compared with 18 % (6/34) of pMMR-WDA (P = 0.0344). Although they are molecularly and morphologically classified as the same chromosomal instability subtype, overall survival (OS) and disease-free-survival (DFS) in pMMR-solid-type-PDA were significantly worse than those in pMMR-WDA [P = 0.0216 (OS) and P = 0.0160 (DFS)]. Our study demonstrates that immunoexpressions of several immunoregulatory proteins and TILs are more prevalent in dMMR-solid-type-PDA, potentially a useful discovery for designing tumor treatments with immune checkpoint inhibitors or combination therapies with a PD-1/PD-L1-inhibitor and IDO1-inhibitor.

Rectal Phenotype of Perianal Paget Disease: Rare Concomitant Phenomena.

Aim: Classically, 'Paget disease' refers to a distinct histological pattern in breast carcinoma. Here, we review the clinicopathological features of anorectal adenocarcinoma with 'pagetoid' spread. Materials and Methods: Histological and immunohistochemical records for 11 cases of anorectal adenocarcinoma with pagetoid spread among 958 Japanese patients with primary rectal/anal carcinoma were reviewed. Results: Grossly, nine of 11 cases had areas of invasive carcinoma: Tubular adenocarcinoma in eight and neuroendocrine carcinoma in one. Pagetoid components were positive for cytokeratin 7 in eight cases, cytokeratin 20 and caudal type homeobox 2 in all 11 cases, and p63 in one case, but were negative for estrogen receptor, progesterone receptor, human epidermal growth factor receptor 2 (HER2), gross cystic disease fluid protein-15, and GATA binding protein 3. Conclusion: The prevalence of perianal Paget disease in this series was 1.1%, with two cases of genuine perianal Paget disease with a rectal phenotype without invasive carcinoma. The rectal phenotype of perianal Paget disease may not be associated with HER2 overexpression.

Hierarchical microstructure strengthening in a single crystal high entropy superalloy.

A hierarchical microstructure strengthened high entropy superalloy (HESA) with superior cost specific yield strength from room temperature up to 1,023 K is presented. By phase transformation pathway through metastability, HESA possesses a hierarchical microstructure containing a dispersion of nano size disordered FCC particles inside ordered L12 precipitates that are within the FCC matrix. The average tensile yield strength of HESA from room temperature to 1,023 K could be 120 MPa higher than that of advanced single crystal superalloy, while HESA could still exhibit an elongation greater than 20%. Furthermore, the cost specific yield strength of HESA can be 8 times that of some superalloys. A template for lighter, stronger, cheaper, and more ductile high temperature alloy is proposed.

Change of Deformation Mechanisms Leading to High Strength and Large Ductility in Mg-Zn-Zr-Ca Alloy with Fully Recrystallized Ultrafine Grained Microstructures.

Recently, we have found that fully recrystallized ultrafine-grained (UFG) microstructures could be realized in a commercial precipitation-hardened Magnesium (Mg) alloy. The UFG specimens exhibited high strength and large ductility under tensile test, but underlying mechanisms for good mechanical properties remained unclear. In this study, we have carried out systematic observations of deformation microstructures for revealing the influence of grain size on the change of dominant deformation modes. We found that plastic deformation of conventionally coarse-grained specimen was predominated by {0001} <11-20> slip and {10-12} <10-11> twinning, and the quick decrease of work-hardening rate was mainly due to the early saturation of deformation twins. For the UFG specimens, {10-12} <10-11> twinning was dramatically suppressed, while non-basal slip systems containing component of Burgers vector were activated, which contributed significantly to the enhanced work-hardening rate leading to high strength and large ductility. It was clarified by this study that limited ductility of hexagonal Mg alloys could be overcome by activating unusual slip systems ( dislocations) in fully recrystallized UFG microstructures.

MRI evaluation of growth plate closure rate and pattern in the normal knee joint.

The records of 320 patients (145 boys and 175 girls) who underwent magnetic resonance imaging (MRI) for the diagnosis of meniscal injury were reviewed. Growth plates of the distal femur and proximal tibia were examined, and the closure rate of the growth plates in each age group was evaluated. Imaging of the growth plates was low-signal intensity on T1-weighted MRI, high-signal intensity on T2-weighted MRI, and high-signal intensity on T2-gradient-recalled echo MRI. The disappearance rates of high-signal band on T2-gradient-recalled echo MRI in each age group were: 0% at < or = 11 years, 5% at 12 years, 34% at 13 years, 53% at 14 years, 94% at 15 years, and 100% at > or = 16 years. In the tibial growth plate on coronal MRI, the central portion had a tendency to close earlier than the peripheral portion. The results of this study suggest T2-gradient-recalled echo MRI should be used for diagnosis and follow-up of the growth plate. Furthermore, the fact that growth plate closure starts centrally suggests the possibility of using a tibial tunnel for anterior cruciate ligament reconstruction in young patients.

Increased signal intensity in the normal glenoid labrum in MR imaging: diagnostic pitfalls caused by the magic-angle effect.

PURPOSE: To determine the effect of the magic-angle effect on the MR signal in the posterosuperior portion of the glenoid labrum. METHODS: MR imaging of 15 arthroscopically evaluated shoulders, five with posterosuperior labrum injury and ten intact, was retrospectively reviewed. In the first part of the study, the signal intensity of the posterosuperior labrum on gradient-recalled echo (GRE) T2*-weighted axial images was correlated with the arthroscopy findings. The second part of the study was designed to illustrate the orientation-dependent signal that occurs in the posterosuperior labrum of three asymptomatic volunteers when imaged in the conventional supine position and in a position similar to Trendelenburg's. Another three volunteers were examined with GRE T2*-weighted axial images to assess the echo-time (TE)-dependent signal in the labrum. RESULTS: The signal increase in the posterosuperior labrum was identified not only in the injured labra but also in nine of 10 intact labra. In the volunteers' studies, the signal in the posterosuperior labrum changed according to the examinees' positions (conventional supine or similar to Trendelenburg's) and according to TE. CONCLUSIONS: Increased signal intensity due to the magic-angle effect may be misdiagnosed as a labrum injury. Awareness of this pitfall is particularly important in MR imaging of throwing athletes whose posterosuperior labra are frequently injured by posterosuperior glenoid impingement.