The utility of diffusion-weighted imaging and ADC values in the characterization of mumps orchitis and seminoma.

BACKGROUND: Diffusion-weighted imaging (DWI) can quantitatively reflect the diffusion characteristics of tissues, providing a theoretical basis for qualitative diagnosis and quantitative analysis of a disease. PURPOSE: To characterize testicular lesions that present as a hypointense signal on magnetic resonance imaging (MRI) T2-weighted images using DWI. MATERIAL AND METHODS: Study participants were divided into three groups. Group A were healthy controls (n = 35), group B included patients with mumps orchitis (n = 20), and group C included patients with seminoma (n = 15). DWI sequences used b-values of 0, 1000, and 2000 s/mm2. Apparent diffusion coefficient (ADC) values between 1000 and 2000 s/mm2 were calculated by MRI postprocessing software. The Kruskal-Wallis test and receiver operating characteristic analysis were performed to evaluate how well ADC values distinguished between mumps orchitis and seminoma. RESULTS: Normal testicular tissue showed a hyperintense signal on DWI and hypointensity on the ADC map: mean ADC value was 0.77 (0.69-0.85) ± 0.08 ×10-3 mm2/s. Mumps orchitis and seminoma showed slight hyperintensity on DWI: mean ADC values were 0.85 (0.71-0.99) ± 0.15 ×10-3 mm2/s and 0.43 (0.39-0.47) ± 0.04 × 10-3 mm2/s, respectively. There were statistically significant differences in mean ADC values between normal testicular tissue and seminoma and between mumps orchitis and seminoma. The cutoff ADC value for differentiating seminoma from mumps orchitis was 0.54 × 10-3 mm2/s. The sensitivity, specificity, and Youden Index for diagnosing seminoma were 99%, 31%, and 30%, respectively. CONCLUSION: High b-value DWI has potential utility for differentiating mumps orchitis from seminoma in the clinical setting.

Concise solid-phase synthesis enables derivatisation of YEATS domain cyclopeptide inhibitors for improved cellular uptake.

YEATS domains, which are newly identified epigenetic readers of histone lysine acetylation and crotonylation, have emerged as promising anti-cancer drug targets. We recently developed AF9 YEATS domain-selective cyclopeptide inhibitors. However, the cumbersome and time-consuming synthesis of the cyclopeptides limited further structural derivatisation and applications. Here, we reported a concise method for the solid-phase synthesis of the cyclopeptides, which substantially reduced the amount of time required for the preparation of the cyclopeptides and led to a higher overall yield. Moreover, this new synthetic route also allowed further derivatisation of the cyclopeptides with various functional modules, including fluorescent dye and cell-penetrating peptide. We demonstrated that the conjugation of the cyclopeptide with cell-penetrating peptide TAT led to a significantly increased cellular uptake.

Apparent diffusion coefficient values of cryptorchid testes and malignant transformation of cryptorchidism (MTC) (seminoma) in postpubertal patients.

OBJECTIVES: Diffusion-weighted imaging signal contrast can be quantified by apparent diffusion coefficient (ADC) maps, which reflect the diffusion properties of the examined tissue and are helpful for identifying pathology. To determine ADC values of cryptorchid testes in post-pubertal patients and assess performance for characterizing cryptorchid testes. METHODS: The medical records from 35 patients with unilateral scrotal vacuity were retrospectively reviewed. Data were analyzed in three groups: Group A, normal testes (i.e. the contralateral testes of the patients with cryptorchidism or MTC); Group B, cryptorchid testes; and Group C, malignant transformation of cryptorchidism (MTC) (seminoma). DWI used b-values of 0 and 800 s/mm2. Mean ADC values were compared using the independent samples t-test. The ability of ADC values was assessed using receiver operating characteristic curve analysis. The sensitivity, specificity, and accuracy were calculated. RESULTS: Mean ADC values for normal testes, cryptorchid testes, and MTC were 1.18 ± 0.18×10-3 mm2/s, 1.82 ± 0.40×10-3 mm2/s, and 0.80 ± 0.06×10-3 mm2/s, respectively. There were statistically significant differences in mean ADC values between normal testes and cryptorchid testes or MTC (p < 0.001). The cut-off ADC value for differentiating normal testes from cryptorchid testes was 1.47 × 10-3 mm2/s. The sensitivity, specificity, and accuracy were 88%, 91%, and 90%, respectively. The cut-off ADC value for differentiating normal testes from MTC was 1.22 × 10-3 mm2/s. The sensitivity, specificity, and accuracy were 100%, 31%, and 43%, respectively. CONCLUSION: ADC values of cryptorchid testes may be used to inform clinical decision-making and also monitor testicular function in patients who retain undescended testicles or post-operatively. ADVANCES IN KNOWLEDGE: Mean ADC values of cryptorchidism and MTC (seminoma) were used to reflect their pathological features.

Selective Targeting of AF9 YEATS Domain by Cyclopeptide Inhibitors with Preorganized Conformation.

YEATS domains are newly identified epigenetic "readers" of histone lysine acetylation (Kac) and crotonylation (Kcr). The malfunction of YEATS-Kac/Kcr interactions has been found to be involved in the pathogenesis of human diseases, such as cancer. These discoveries suggest that the YEATS domains are promising novel drug targets. We and others recently reported the development of YEATS domain inhibitors. Although these inhibitors have a general preference toward the AF9 and ENL YEATS domains, selective inhibitors targeting either YEATS domain are challenging to develop as these two proteins share a high structural similarity. In this study, we identified a proximal site outside the acyllysine-binding pocket that can differentiate AF9 YEATS from ENL YEATS. Combinatorial targeting of both the acyllysine pocket and this additional site by conformationally preorganized cyclopeptides enabled the selective inhibition of the AF9 YEATS domain. The most selective inhibitor, JYX-3, showed a 38-fold higher binding affinity toward AF9 YEATS over ENL YEATS. Further investigations indicated that JYX-3 could engage with AF9 in living cells, disrupt the YEATS-dependent chromatin recruitment of AF9, and suppress the transcription of AF9 target genes.

IFN-γ regulates the transformation of microglia into dendritic-like cells via the ERK/c-myc signaling pathway during cerebral ischemia/reperfusion in mice.

Cerebral ischemia-reperfusion injury induces a secondary immune inflammatory reaction that exacerbates brain injury and clinical prognosis. Dendritic cells (DCs) and microglia are both important regulators of neuroinflammation. Studies have confirmed that a large number of cells express the DC surface marker CD11c in the ischemic area, and some of these cells also express microglial markers. However, the specific mechanism of transformation between microglia and DCs and their roles in the process of cerebral ischemia-reperfusion injury are still not clear. In this study, we established a mouse model and flow cytometry was used to detect the expression of mature DC surface molecules in activated microglia. IFN-γ knockout mice were used to determine the regulatory effect of IFN-γ on microglial transformation. We found that CD11c+ cells were derived from microglia after ischemia-reperfusion injury, and this group of cells highly expressed MHC-II molecules and other costimulatory molecules, such as CD80 and CD86, which were regulated by IFN-γ and its downstream signaling molecules ERK/c-myc. In summary, our results showed in cerebral ischemia-reperfusion injury, IFN-γ regulates the transformation of microglia to DC-like cells. Microglial-derived DC-like cells possess the ability to present antigens and activate naïve T cells which is regulated by the ERK/c-myc signaling pathway.

Excess salt intake promotes M1 microglia polarization via a p38/MAPK/AR-dependent pathway after cerebral ischemia in mice.

A high salt diet (HSD) is among the most important risk factors for many diseases. One mechanism by which HSD aggravates cerebral ischemic injury is independent of blood pressure changes. The direct role of HSD in inflammation after cerebral ischemia is unclear. In this research, after twenty-one days of being fed a high salt diet, permanent focal ischemia was induced in mice via operation. At 12 h and 1, 3 and 5 days postischemia, the effects of HSD on the lesion volume, microglia polarization, aldose reductase (AR) expression, and inflammatory processes were analyzed. We report that in mice, surplus dietary salt promotes inflammation and increases the activation of classical lipopolysaccharide (LPS)-induced microglia/macrophages (M1). This effect depends on the expression of the AR protein in activated microglia after permanent middle cerebral artery ligation (pMCAL) in HSD mice. The administration of either the AR inhibitor Epalrestat or a p38-neutralizing antibody blocked the polarization of microglia and alleviated stroke injury. In conclusion, HSD promotes polarization in pro-inflammatory M1 microglia by upregulating the expression of the AR protein via p38/MAPK, thereby exacerbating the development of ischemia stroke.

MRI findings of an atypical testicular epidermoid cyst: A case report.

INTRODUCTION: Typical testicular epidermoid cysts (TECs) manifestate as a target sign or onion skin sign on ultrasonography and magnetic resonance (MR) imaging. Clinicians are increasingly aware of the imaging characteristics of typical TECs, which allow accurate diagnosis and successful treatment while preserving the testicle, but atypical TECs are likely to be misdiagnosed as a malignant intratesticular neoplasm, leading to complete testicular resection. PATIENT CONCERNS: A 26 year-old male patient complained of a painless enlargement of the left testicle that had been present for 1 month. The patient had no recent medical history of scrotal trauma or systemic infection. DIAGNOSIS: A round 48 mm × 45 mm × 43 mm mass was seen inside the left testicle. T2-weighted images of the lesion showed a thin hypointense capsule. T1-weighted images of the lesion showed a hyperintense nodule on the cyst wall, which appeared hypointense on T2-weighted and SPAIR images. After Gd-DTPA injection, the lesion was not enhanced; however, the nodule was enhanced on THRIVE images. These manifestations were consistent with a benign intratesticular lesion, and MR imaging diagnosed atypical TEC, which was confirmed by pathology after surgery. INTERVENTIONS: The patient was treated with organ-sparing surgery with testicular enucleation. OUTCOMES: The patient was re-examined with ultrasonography 3 months after surgery. The left residual testicular tissue appeared normal, and reproductive function was preserved. CONCLUSION: Urologists must be aware of the clinical and MR imaging characteristics of atypical TECs and the utility of preoperative MR imaging for the diagnosis of testicular lesions to ensure that organ-sparing surgery is performed rather than unnecessary orchiectomy.

Targeting the Amyloid-ß Fibril Surface with a Constrained Helical Peptide Inhibitor.

Amyloid-ß (Aß) oligomers are well-known toxic molecular species associated with Alzheimer's disease. Recent discoveries of the ability of amyloid fibril surfaces to convert soluble proteins into toxic oligomers suggested that these surfaces could serve as therapeutic targets for intervention. We have shown previously that a short helical peptide could be a key structural motif that can specifically recognize the K16-E22 region of the Aß40 fibril surface with an affinity at the level of several micromolar. Here, we demonstrate that in-tether chiral center-induced helical stabilized peptides could also recognize the fibril surfaces, effectively inhibiting the surface-mediated oligomerization of Aß40. Moreover, through extensive computational sampling, we observed two distinct ways in which the peptide inhibitors recognize the fibril surface. Apart from a binding mode that, in accord with the original design, involves hydrophobic side chains at the binding interface, we observed much more frequently another binding mode in which the hydrophobic staple interacts directly with the fibril surface. The affinity of the peptides for the fibril surface could be adjusted by tuning the hydrophobicity of the staple. The best candidate investigated here exhibits a submicromolar affinity (∼0.75 µM). Collectively, this work opens an avenue for the rational design of candidate drugs with stapled peptides for amyloid-related disease.

Differentiation of testicular seminoma and nonseminomatous germ cell tumor on magnetic resonance imaging.

Magnetic resonance imaging (MRI) has excellent soft tissue resolution, as well as multidirectional and multisequence scanning technology, making it an important supplementary method in the diagnosis of testicular tumor.To explore the utility of preoperative MRI for the differential diagnosis of testicular seminoma and nonseminomatous germ cell tumors (NSGCTs).The medical records from 39 patients with testicular tumors that were examined preoperatively with MRI and treated with urologic surgery at our institution between January 2015 and March 2019 were retrospectively reviewed. Testicular tumors were confirmed by pathology and classified as seminoma (n = 20) or NSGCT (n = 19). Two radiologists analyzed the testicular tumors on preoperative MRI for morphology: multiple nodules or a single mass; presence/absence of a capsule; signal compared to the normal contralateral testicle (isointense, hypointense, hyperintense, or mixed); enhancement; septa; and hemorrhagic or cystic degeneration. Characteristics of seminomas and NSGCT were compared using the Chi-square or Fischer exact test.MRI showed that the majority (95%; 19/20) of seminomas were nodular. There were significant differences in the presence/absence of a capsule (P = .001), T1-weighted imaging (T1WI) signal intensity (P = .047), T2-weighted imaging (T2WI) signal intensity (P < .001), septa (P < .001), and hemorrhagic or cystic degeneration (P < .001) between seminomas and NSGCT.Seminomas were more likely to have no capsule, isointensity on T1WI, hypointensity on T2WI, and had narrow obviously enhanced fibrovascular septa without hemorrhagic or cystic degeneration; NSGCT was more likely to have a capsule, a mainly mixed signal on T1WI and T2WI, most of them had no fibrovascular septa, and hemorrhagic or cystic degeneration was common in malignant NSGCT.This study suggests that preoperative MRI can distinguish seminoma from NSGCT. We propose that preoperative MRI of the scrotum is an effective technique that should be widely adopted for the management of scrotal disease.

A sulfonium tethered peptide ligand rapidly and selectively modifies protein cysteine in vicinity.

Significant efforts have been invested to develop site-specific protein modification methodologies in the past two decades. In most cases, a reactive moiety was installed onto ligands with the sole purpose of reacting with specific residues in proteins. Herein, we report a unique peptide macrocyclization method via the bis-alkylation between methionine and cysteine to generate cyclic peptides with significantly enhanced stability and cellular uptake. Notably, when the cyclized peptide ligand selectively recognizes its protein target with a proximate cysteine, a rapid nucleophilic substitution could occur between the protein Cys and the sulfonium center on the peptide to form a conjugate. The conjugation reaction is rapid, facile and selective, triggered solely by proximity. The high target specificity is further proved in cell lysate and hints at its further application in activity based protein profiling. This method enhances the peptide's biophysical properties and generates a selective ligand-directed reactive site for protein modification and fulfills multiple purposes by one modification. This proof-of-concept study reveals its potential for further broad biological applications.

Chemical Proteomic Profiling of Bromodomains Enables the Wide-Spectrum Evaluation of Bromodomain Inhibitors in Living Cells.

Bromodomains, epigenetic "readers" of lysine acetylation marks, exist in different nuclear proteins with diverse biological functions in chromatin biology. Malfunctions of bromodomains are associated with the pathogenesis of human diseases, such as cancer. Bromodomains have therefore emerged as therapeutic targets for drug discovery. Given the high structural similarity of bromodomains, a critical step in the development of bromodomain inhibitors is the evaluation of their selectivity to avoid off-target effects. While numerous bromodomain inhibitors have been identified, new methods to evaluate the inhibitor selectivity toward endogenous bromodomains in living cells remain needed. Here we report the development of a photoaffinity probe, photo-bromosporine (photo-BS), that enables the wide-spectrum profiling of bromodomain inhibitors in living cells. Photo-BS allowed light-induced cross-linking of recombinant bromodomains and endogenous bromodomain-containing proteins (BCPs) both in vitro and in living cells. The photo-BS-induced labeling of the bromodomains was selectively competed by the corresponding bromodomain inhibitors. Proteomics analysis revealed that photo-BS captured 28 out of the 42 known BCPs from the living cells. Assessment of the two bromodomain inhibitors, bromosporine and GSK6853, resulted in the identification of known as well as previously uncharacterized bromodomain targets. Collectively, we established a chemical proteomics platform to comprehensively evaluate bromodomain inhibitors in terms of their selectivity against endogenous BCPs in living cells.

Conformation Dependence of Diphenylalanine Self-Assembly Structures and Dynamics: Insights from Hybrid-Resolution Simulations.

The molecular design of peptide-assembled nanostructures relies on extensive knowledge pertaining to the relationship between conformational features of peptide constituents and their behavior regarding self-assembly, and characterizing the conformational details of peptides during their self-assembly is experimentally challenging. Here, we demonstrate that a hybrid-resolution modeling method can be employed to investigate the role that conformation plays during the assembly of terminally capped diphenylalanines (FF) through microsecond simulations of hundreds or thousands of peptides. Our simulations discovered tubular or vesicular nanostructures that were consistent with experimental observation while reproducing critical self-assembly concentration and secondary structure contents in the assemblies that were measured in our experiments. The atomic details provided by our method allowed us to uncover diverse FF conformations and conformation dependence of assembled nanostructures. We found that the assembled morphologies and the molecular packing of FFs in the observed assemblies are linked closely with side-chain angle and peptide bond orientation, respectively. Of various conformations accessible to soluble FFs, only a select few are compatible with the assembled morphologies in water. A conformation resembling a FF crystal, in particular, became predominant due to its ability to permit highly ordered and energetically favorable FF packing in aqueous assemblies. Strikingly, several conformations incompatible with the assemblies arose transiently as intermediates, facilitating key steps of the assembly process. The molecular rationale behind the role of these intermediate conformations were further explained. Collectively, the structural details reported here advance the understanding of the FF self-assembly mechanism, and our method shows promise for studying peptide-assembled nanostructures and their rational design.

Clinical determination of serum nardilysin levels in predicting 30-day mortality among adults with malignant cerebral infarction.

BACKGROUND: Nardilysin, a kind of metalloendopeptidase, plays an important role in numerous inflammatory diseases. Malignant cerebral infarction (Glasgow coma scale score of <9) is associated with a high mortality risk. Here, we intended to investigate the relationship between serum nardilysin levels and prognosis of patients with malignant cerebral infarction. METHODS: Serum nardilysin concentrations were quantified at malignant cerebral infarction diagnosis moment in 105 patients and at study entrance in 105 healthy controls. Association of nardilysin concentrations with 30-day mortality and overall survival was estimated using multivariate analyses. RESULTS: The patients exhibited substantially increased serum nardilysin concentrations, as compared to the controls. Nardilysin concentrations were in pronounced correlation with Glasgow coma scale scores and serum C-reactive protein concentrations. Serum nardilysin was independently predictive of 30-day mortality and overall survival. Under receiver operating characteristic curve, its high discriminatory ability was found. CONCLUSIONS: Rising serum nardilysin concentrations following malignant cerebral infarction are strongly related to stroke severity, inflammatory extent and a higher risk of mortality, substantializing serum nardilysin as a potential prognostic biomarker for malignant cerebral infarction.

Structure-guided development of YEATS domain inhibitors by targeting π-π-π stacking.

Chemical probes of epigenetic 'readers' of histone post-translational modifications (PTMs) have become powerful tools for mechanistic and functional studies of their target proteins in normal physiology and disease pathogenesis. Here we report the development of the first class of chemical probes of YEATS domains, newly identified 'readers' of histone lysine acetylation (Kac) and crotonylation (Kcr). Guided by the structural analysis of a YEATS-Kcr complex, we developed a series of peptide-based inhibitors of YEATS domains by targeting a unique π-π-π stacking interaction at the proteins' Kcr recognition site. Further structure optimization resulted in the selective inhibitors preferentially binding to individual YEATS-containing proteins including AF9 and ENL with submicromolar affinities. We demonstrate that one of the ENL YEATS-selective inhibitors, XL-13m, engages with endogenous ENL, perturbs the recruitment of ENL onto chromatin, and synergizes the BET and DOT1L inhibition-induced downregulation of oncogenes in MLL-rearranged acute leukemia.

Tuning peptide self-assembly by an in-tether chiral center.

The self-assembly of peptides into ordered nanostructures is important for understanding both peptide molecular interactions and nanotechnological applications. However, because of the complexity and various self-assembling pathways of peptide molecules, design of self-assembling helical peptides with high controllability and tunability is challenging. We report a new self-assembling mode that uses in-tether chiral center-induced helical peptides as a platform for tunable peptide self-assembly with good controllability. It was found that self-assembling behavior was governed by in-tether substitutional groups, where chirality determined the formation of helical structures and aromaticity provided the driving force for self-assembly. Both factors were essential for peptide self-assembly to occur. Experiments and theoretical calculations indicate long-range crystal-like packing in the self-assembly, which was stabilized by a synergy of interpeptide π-π and π-sulfur interactions and hydrogen bond networks. In addition, the self-assembled peptide nanomaterials were demonstrated to be promising candidate materials for applications in biocompatible electrochemical supercapacitors.

Asymmetric cinnamylation of N-tert-butanesulfinyl imines with cinnamyl acetates: total syntheses of (+)-lycoricidine and (+)-7-deoxypancratistatin.

Highly diastereoselective palladium catalyzed cinnamylation of N-tert-butanesulfinyl imines with cinnamyl acetates has been established to provide enantioenriched ß-aryl homoallylic amines. The synthetic application of this stragety has been successfully demonstrated in the concise total syntheses of antitumor natural products (+)-lycoricidine and (+)-7-deoxypancratistatin.

Switching substitution groups on the in-tether chiral centre influences backbone peptides' permeability and target binding affinity.

Different substitution groups on the in-tether chiral centre of chirality-induced helical peptides (CIH peptides) showed distinguishable effects on the peptides' cellular uptakes and binding affinities with the estrogen receptor α(ER-α). This study proves that in-tether chiral centres are a valuable modification site for constructing peptide ligands with preferable biophysical properties.

The 12 Gastrointestinal Pathogens Spectrum of Acute Infectious Diarrhea in a Sentinel Hospital, Shenzhen, China.

Acute infectious gastroenteritis is one of the most common diseases among all ages, particularly in developing countries. The pathogen spectrum may differ among different regions and seasons. To investigate the etiology of acute diarrhea in Shenzhen, a prospective study was conducted from August 2014 to September 2015. Stools from 412 patients with diarrhea (286 of whom were adults) including the general epidemiological information of the patients were collected. The 19 pathogens were detected by conventional culture method or multiplex PCR assay, which included five viruses (rotavirus, adenovirus, sapovirus, norovirus, and astrovirus), 11 bacterial pathogens (Salmonella, Campylobacter jejuni, Shigella, Listeria monocytogenes, Vibrio parahaemolyticus, Vibrio cholera, Enterohemorrhagic (EHEC), enteropathogenic (EPEC), enteroinvasive (EIEC), enterotoxigenic (ETEC); and enteroaggregative Escherichia coli (EAEC)) and three parasites (Entamoeba histolytica, Giardia lamblia, and Cryptosporidium parvum). A potential pathogen and coinfection was found in 41.5 and 7.0% of cases, respectively. The bacterial infection was the dominant cause of diarrhea (32.3%), and the three most frequently identified organisms were Salmonella (12.1%), ETEC (8.0%), and Campylobacter jejuni (4.9%). Salmonella enteritidis was the leading serotype of Salmonella sp. Norovirus (8.3%) and sapovirus (2.2%) were the most common viral pathogens, followed by adenovirus (1.5%) and rotavirus (1.2%). No EHEC, L. monocytogenes, V. cholera, Shigella, and parasites were found. The single most important causes of diarrhea were Salmonella spp. and Campylobacter jejuni, which points toward the need for testing and surveillance for these pathogens in this region.

Simultaneous detection of five enteric viruses associated with gastroenteritis by use of a PCR assay: a single real-time multiplex reaction and its clinical application.

We developed a highly sensitive reverse transcription and multiplex real-time PCR (rtPCR) assay that can identify five viruses, including six genogroups, in a single reaction: norovirus genogroups I and II; sapovirus genogroups I, II, IV, and V; human rotavirus A; adenovirus serotypes 40 and 41; and human astrovirus. In comparison to monoplex rtPCR assays, the sensitivities and specificities of the multiplex rtPCR ranged from 75% to 100% and from 99% to 100%, respectively, evaluated on 812 clinical stool specimens.