An optimal promoter regulating cytokine transgene expression is crucial for safe and effective oncolytic virus immunotherapy.

In general, ensuring safety is the top priority of a new modality. Although oncolytic virus armed with an immune stimulatory transgene (OVI) showed some promise, the strategic concept of simultaneously achieving maximum effectiveness and minimizing side effects has not been fully explored. We generated a variety of survivin-responsive "conditionally replicating adenoviruses that can target and treat cancer cells with multiple factors (m-CRAs)" (Surv.m-CRAs) armed with the granulocyte-macrophage colony-stimulating factor (GM-CSF) transgene downstream of various promoters using our m-CRA platform technology. We carefully analyzed both therapeutic and adverse effects of them in the in vivo syngeneic Syrian hamster cancer models. Surprisingly, an intratumor injection of a conventional OVI, which expresses the GM-CSF gene under the constitutively and strongly active "cytomegalovirus enhancer and ß-actin promoter", provoked systemic and lethal GM-CSF circulation and shortened overall survival (OS). In contrast, a new conceptual type of OVI, which expressed GM-CSF under the cancer-predominant and mildly active E2F promoter or the moderately active "Rous sarcoma virus long terminal repeat", not only abolished lethal adverse events but also prolonged OS and systemic anti-cancer immunity. Our study revealed a novel concept that optimal expression levels of an immune stimulatory transgene regulated by a suitable upstream promoter is crucial for achieving high safety and maximal therapeutic effects simultaneously in OVI therapy. These results pave the way for successful development of the next-generation OVI and alert researchers about possible problems with ongoing clinical trials.

Deep Learning Reconstruction for DWIs by EPI and FASE Sequences for Head and Neck Tumors.

BACKGROUND: Diffusion-weighted images (DWI) obtained by echo-planar imaging (EPI) are frequently degraded by susceptibility artifacts. It has been suggested that DWI obtained by fast advanced spin-echo (FASE) or reconstructed with deep learning reconstruction (DLR) could be useful for image quality improvements. The purpose of this investigation using in vitro and in vivo studies was to determine the influence of sequence difference and of DLR for DWI on image quality, apparent diffusion coefficient (ADC) evaluation, and differentiation of malignant from benign head and neck tumors. METHODS: For the in vitro study, a DWI phantom was scanned by FASE and EPI sequences and reconstructed with and without DLR. Each ADC within the phantom for each DWI was then assessed and correlated for each measured ADC and standard value by Spearman's rank correlation analysis. For the in vivo study, DWIs obtained by EPI and FASE sequences were also obtained for head and neck tumor patients. Signal-to-noise ratio (SNR) and ADC were then determined based on ROI measurements, while SNR of tumors and ADC were compared between all DWI data sets by means of Tukey's Honest Significant Difference test. RESULTS: For the in vitro study, all correlations between measured ADC and standard reference were significant and excellent (0.92 ≤ ρ ≤ 0.99, p < 0.0001). For the in vivo study, the SNR of FASE with DLR was significantly higher than that of FASE without DLR (p = 0.02), while ADC values for benign and malignant tumors showed significant differences between each sequence with and without DLR (p < 0.05). CONCLUSION: In comparison with EPI sequence, FASE sequence and DLR can improve image quality and distortion of DWIs without significantly influencing ADC measurements or differentiation capability of malignant from benign head and neck tumors.

Genomic and phylogenetic characterization of Elizabethkingia anophelis strains: The first two cases of life-threatening infection in Japan.

OBJECTIVE: Elizabethkingia anophelis causes meningitis, bloodstream infections, and respiratory infections in immunocompromised individuals. We examined two E. anophelis strains isolated from the first life-threatening cases caused by this species in Japan to determine the phylogenetic origin and genomic features of them. METHODS: We performed whole genome-based analysis to clarify the genetic relationship for the two strains (EK0004 and EK0079) and Elizabethkingia sp. strains isolated from worldwide and to characterize the genomic features such as the prevalence of virulence- and antimicrobial resistance (AMR)-related genes. PATIENTS: A 29-year-old man with hepatosplenic T-cell lymphoma and a 52-year-old man with systemic lupus erythematosus developed fatal bacteremia and meningitis due to E. anophelis, respectively. RESULTS: Two strains, EK0004 and EK0079, were genetically different but most closely related to the strains isolated from the largest outbreak in Wisconsin, USA from 2015 to 2016, and the strain isolated from cerebrospinal fluid of a patient in Florida, USA in 1982, respectively. The two strains contained AMR-related genes such as those encoding for an extended-spectrum ß-lactamase and multiple metallo-ß-lactamases and several virulence-related genes such as capsular polysaccharide synthesis gene clusters. CONCLUSIONS: Although further functional analyses are required to understand the virulence of these clones, these finding suggests that enough caution of E. anophelis infection in immunocompromised patients is required since the number of infections by this species is increasing outside Japan.

Computed DWI MRI Results in Superior Capability for N-Stage Assessment of Non-Small Cell Lung Cancer Than That of Actual DWI, STIR Imaging, and FDG-PET/CT.

BACKGROUND: Computed diffusion-weighted imaging (cDWI) is a mathematical computation technique that generates DWIs for any b-value by using actual DWI (aDWI) data with at least two different b-values and may improve differentiation of metastatic from nonmetastatic lymph nodes. PURPOSE: To determine the appropriate b-value for cDWI to achieve a better diagnostic capability for lymph node staging (N-staging) in non-small cell lung cancer (NSCLC) patients compared to aDWI, short inversion time (TI) inversion recovery (STIR) imaging, or positron emission tomography with 2-[fluorine-18] fluoro-2-deoxy-d-glucose combined with computed tomography (FDG-PET/CT). STUDY TYPE: Prospective. SUBJECTS: A total of 245 (127 males and 118 females; mean age 72 years) consecutive histopathologically confirmed NSCLC patients. FIELD STRENGTH/SEQUENCE: A 3 T, half-Fourier single-shot turbo spin-echo sequence, electrocardiogram (ECG)-triggered STIR fast advanced spin-echo (FASE) sequence with black blood and STIR acquisition and DWI obtained by FASE with b-values of 0 and 1000 sec/mm2 . ASSESSMENT: From aDWIs with b-values of 0 and 1000 (aDWI1000 ) sec/mm2 , cDWI using 400 (cDWI400 ), 600 (cDWI600 ), 800 (cDWI800 ), and 2000 (cDWI2000 ) sec/mm2 were generated. Then, 114 metastatic and 114 nonmetastatic nodes (mediastinal and hilar lymph nodes) were selected and evaluated with a contrast ratio (CR) for each cDWI and aDWI, apparent diffusion coefficient (ADC), lymph node-to-muscle ratio (LMR) on STIR, and maximum standard uptake value (SUVmax ). STATISTICAL TESTS: Receiver operating characteristic curve (ROC) analysis, Youden index, and McNemar's test. RESULTS: Area under the curve (AUC) of CR600 was significantly larger than the CR400 , CR800 , CR2000 , aCR1000 , and SUVmax . Comparison of N-staging accuracy showed that CR600 was significantly higher than CR400 , CR2000 , ADC, aCR1000 , and SUVmax , although there were no significant differences with CR800 (P = 0.99) and LMR (P = 0.99). DATA CONCLUSION: cDWI with b-value at 600 sec/mm2 may have potential to improve N-staging accuracy as compared with aDWI, STIR, and PET/CT. EVIDENCE LEVEL: 2 TECHNICAL EFFICACY: Stage 2.

Deep Learning Reconstruction of Diffusion-weighted MRI Improves Image Quality for Prostatic Imaging.

Background Deep learning reconstruction (DLR) may improve image quality. However, its impact on diffusion-weighted imaging (DWI) of the prostate has yet to be assessed. Purpose To determine whether DLR can improve image quality of diffusion-weighted MRI at b values ranging from 1000 sec/mm2 to 5000 sec/mm2 in patients with prostate cancer. Materials and Methods In this retrospective study, images of the prostate obtained at DWI with a b value of 0 sec/mm2, DWI with a b value of 1000 sec/mm2 (DWI1000), DWI with a b value of 3000 sec/mm2 (DWI3000), and DWI with a b value of 5000 sec/mm2 (DWI5000) from consecutive patients with biopsy-proven cancer from January to June 2020 were reconstructed with and without DLR. Image quality was assessed using signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) from region-of-interest analysis and qualitatively assessed using a five-point visual scoring system (1 [very poor] to 5 [excellent]) for each high-b-value DWI sequence with and without DLR. The SNR, CNR, and visual score for DWI with and without DLR were compared with the paired t test and the Wilcoxon signed rank test with Bonferroni correction, respectively. Apparent diffusion coefficients (ADCs) from DWI with and without DLR were also compared with the paired t test with Bonferroni correction. Results A total of 60 patients (mean age, 67 years; age range, 49-79 years) were analyzed. DWI with DLR showed significantly higher SNRs and CNRs than DWI without DLR (P < .001); for example, with DWI1000 the mean SNR was 38.7 ± 0.6 versus 17.8 ± 0.6, respectively (P < .001), and the mean CNR was 18.4 ± 5.6 versus 7.4 ± 5.6, respectively (P < .001). DWI with DLR also demonstrated higher qualitative image quality than DWI without DLR (mean score: 4.8 ± 0.4 vs 4.0 ± 0.7, respectively, with DWI1000 [P = .001], 3.8 ± 0.7 vs 3.0 ± 0.8 with DWI3000 [P = .002], and 3.1 ± 0.8 vs 2.0 ± 0.9 with DWI5000 [P < .001]). ADCs derived with and without DLR did not differ substantially (P > .99). Conclusion Deep learning reconstruction improves the image quality of diffusion-weighted MRI scans of prostate cancer with no impact on apparent diffusion coefficient quantitation with a 3.0-T MRI system. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Turkbey in this issue.

State-of-the-art MR Imaging for Thoracic Diseases.

Since thoracic MR imaging was first used in a clinical setting, it has been suggested that MR imaging has limited clinical utility for thoracic diseases, especially lung diseases, in comparison with x-ray CT and positron emission tomography (PET)/CT. However, in many countries and states and for specific indications, MR imaging has recently become practicable. In addition, recently developed pulmonary MR imaging with ultra-short TE (UTE) and zero TE (ZTE) has enhanced the utility of MR imaging for thoracic diseases in routine clinical practice. Furthermore, MR imaging has been introduced as being capable of assessing pulmonary function. It should be borne in mind, however, that these applications have so far been academically and clinically used only for healthy volunteers, but not for patients with various pulmonary diseases in Japan or other countries. In 2020, the Fleischner Society published a new report, which provides consensus expert opinions regarding appropriate clinical indications of pulmonary MR imaging for not only oncologic but also pulmonary diseases. This review article presents a brief history of MR imaging for thoracic diseases regarding its technical aspects and major clinical indications in Japan 1) in terms of what is currently available, 2) promising but requiring further validation or evaluation, and 3) developments warranting research investigations in preclinical or patient studies. State-of-the-art MR imaging can non-invasively visualize lung structural and functional abnormalities without ionizing radiation and thus provide an alternative to CT. MR imaging is considered as a tool for providing unique information. Moreover, prospective, randomized, and multi-center trials should be conducted to directly compare MR imaging with conventional methods to determine whether the former has equal or superior clinical relevance. The results of these trials together with continued improvements are expected to update or modify recommendations for the use of MRI in near future.

Safe and low-dose but therapeutically effective adenovirus-mediated hepatocyte growth factor gene therapy for type 1 diabetes in mice.

AIMS: Hepatocyte growth factor (HGF) is a multifunctional cytokine that plays important roles in pancreatic physiology. Approvals of gene therapy drugs have highlighted gene therapy as an innovative new drug modality, but the very recent reports of deaths in clinical trials have provided a warning that high-dose gene therapy can cause dangerous liver toxicity. The present study aimed to develop a safe and low-dose but therapeutically effective adenovirus-mediated HGF gene therapy for streptozotocin (STZ)-induced type 1 diabetes (T1D) in mice. MAIN METHODS: A single intravenous injection of a low dose (3 × 108 plaque forming units) of adenoviral vector expressing the HGF gene under the transcriptional control of a strong promoter, i.e., the cytomegalovirus immediate-early enhancer and a modified chicken ß-actin promoter (Ad.CA-HGF), was given to T1D mice. KEY FINDINGS: Low-dose HGF gene therapy significantly attenuated the elevation of blood glucose concentrations at the acute phase of T1D, and this effect persisted for several weeks. Temporal upregulation of plasma insulin at the acute phase was maintained at a normal level in Ad.CA-HGF-treated mice, suggesting that the therapeutic mechanism may involve protection of the remaining ß-cells by HGF. Liver enzymes in plasma were not elevated in any of the mice, including the Ad.CA-HGF-treated animals, all of which looked healthy, suggesting the absence of lethal adverse effects observed in patients receiving high intravenous doses of viral vectors. SIGNIFICANCE: A low dose of intravenous Ad-mediated HGF gene therapy is clinically feasible and safe, and thus represents a new therapeutic strategy for treating T1D.

Clinical Significance of Discrepancy between Arterial Spin Labeling Images and Contrast-enhanced Images in the Diagnosis of Brain Tumors.

PURPOSE: In the imaging of intra-axial brain tumors, we sometimes found areas of high signal intensity around the enhanced tumor lesions on arterial spin labeling (ASL) magnetic resonance (MR) imaging. We undertook this study to investigate the relationship between high signal intensity on ASL imaging outside the area of contrast enhancement (CE) and histological diagnosis of intra-axial brain tumors. METHODS: We examined images from 28 consecutive patients with intra-axial brain tumors who underwent ASL and CE MR imaging-three with low grade glioma (LGG), 13 with high grade glioma (HGG), six with metastasis, and six with primary central nervous system lymphoma (PCNSL)-and divided imaging findings into an "ASL dominant" group when hyperintensity on ASL was found outside the CE area and a "CE dominant" group when hyperintensity on ASL was not found outside the area of enhancement. We then analyzed the relationship between imaging findings and the histological diagnosis of the tumors. RESULTS: Four cases were excluded because of poor quality of ASL images, 7 cases were classified as ASL dominant, and 17 cases were classified as CE dominant. The histological diagnoses of ASL dominant cases were LGG in 3 cases, HGG in 3 cases, and PCNSL in one case. Those of CE dominant cases were HGG in 10 cases, metastasis in 5 cases, and PCNSL in 2 cases. All cases with brain metastasis were classified as CE dominant. CONCLUSION: The high signal intensity outside the area of contrast enhancement is probably caused by increased perfusion or vascular proliferation, which indicates the presence of glioma or PCNSL and not metastasis. This finding indicates a new utility for ASL images in the diagnosis of brain tumors as a supplement to the conventional measurement of perfusion obtained from ASL images.

Diagnosis of brain tumors using dynamic contrast-enhanced perfusion imaging with a short acquisition time.

This study sought to determine the diagnostic utility of perfusion parameters derived from dynamic contrast-enhanced (DCE) perfusion MRI with a short acquisition time (approximately 3.5 min) in patients with glioma, brain metastasis, and primary CNS lymphoma (PCNSL). Twenty-six patients with 29 lesions (4 low-grade glioma, 13 high-grade glioma, 7 metastasis, and 5 PCNSL) underwent DCE-MRI in a 3 T scanner. A ROI was placed on the hotspot of each tumor in maps for volume transfer contrast K (trans) , extravascular extracellular volume V e , and fractional plasma volume V p . We analyzed differences in parameters between tumors using the Mann-Whitney U test. We calculated sensitivity and specificity using receiver operating characteristics analysis. Mean K (trans) values of LGG, HGG, metastasis and PCNSL were 0.034, 0.31, 0.38, 0.44, respectively. Mean Ve values of each tumors was 0.036, 0.57, 0.47, 0.96, and mean Vp value of each tumors was 0.070, 0.086, 0.26, 0.17, respectively. Compared with other tumor types, low-grade glioma showed lower K (trans) (P < 0.01, sensitivity = 88%, specificity = 100%) and lower V e (P < 0.01, sensitivity = 96%, specificity = 100%). PCNSL showed higher V e (P < 0.01, sensitivity = 100%, specificity = 88%), but the other perfusion parameters overlapped with those of different histology. Kinetic parameters derived from DCE-MRI with short acquisition time provide useful information for the differential diagnosis of brain tumors.