Role of mammalian target of rapamycin in the formation and progression of retinopathy of prematurity-like vascular abnormalities in neonatal rats.

Retinopathy of prematurity (ROP), a retinal disease that can occur in premature infants, can lead to severe visual impairment. In this study, we examined the preventive and therapeutic effects of mammalian target of rapamycin complex 1 (mTORC1) inhibition on abnormal retinal blood vessels in a rat model of ROP. To induce ROP-like vascular abnormalities, rats were subcutaneously treated with KRN633, an inhibitor of vascular endothelial growth factor (VEGF) receptor tyrosine kinase, on postnatal day 7 (P7) and P8. KRN633-treated (ROP) rats were treated subcutaneously with the mTORC1 inhibitor rapamycin according to preventive and therapeutic protocols, i.e., from P11 to P13 (P11-P13) and from P14 to P20 (P14-P20), respectively. To compare with the effects of VEGF inhibition, KRN633 was administered according to similar protocols. Changes in retinal vasculature, phosphorylated ribosomal protein S6 (pS6), a downstream indicator of mTORC1 activity, and the proliferative status of vascular cells were evaluated at P14 and P21 using immunohistochemistry. Rapamycin treatment from P11 to P13 prevented increases in arteriolar tortuosity, capillary density, and the number of proliferating vascular cells, and eliminated pS6 immunoreactivity in ROP rats. KRN633 treatment at P11 and P12 (P11/P12) also prevented the appearance of ROP-like retinal blood vessels. Rapamycin treatment from P14 to P20 failed to attenuate arteriolar tortuosity but prevented increases in capillary density and proliferating vascular cell number at the vascular front, but not at the central zone. KRN633 treatment from P14 to P20 significantly reduced abnormalities in the retinal vasculature; however, the effects were inferior to those of KRN633 treatment on P11/P12. These results suggest that activation of the mTORC1 pathway in proliferating endothelial cells contributes to the appearance and progression of ROP-like retinal blood vessels. Therefore, inhibition of mTORC1 may be a promising approach for selectively targeting abnormal retinal blood vessels in ROP.

Multicenter Retrospective Analysis of Original versus Modified FOLFIRINOX in Metastatic Pancreatic Cancer: Results of the NAPOLEON Study.

INTRODUCTION: Original FOLFIRINOX (oFFX) is more toxic than other regimens for patients with metastatic pancreatic cancer (mPC); therefore, a modified FFX (mFFX) regimen with a reduced dosage has been used in Japanese clinical practice. However, very few studies have compared these two regimens. METHODS: This study was conducted as part of a multicenter retrospective study of 318 patients with mPC across 14 centers in Japan (NAPOLEON study). To control for potential bias and confounders, we conducted a propensity score-adjusted analysis of patient characteristics and clinical outcomes. RESULTS: oFFX and mFFX were administered to 48 and 54 patients. More patients with younger age and poorer performance status were included in the oFFX group. The overall survival (OS; median, 11.6 vs. 11.3 months; hazard ratio [HR], 0.91; 95% confidence interval [CI], 0.60-1.40; p = 0.67), progression-free survival (PFS) (median, 6.3 vs. 5.7 months; HR, 0.85; 95% CI, 0.56-1.28; p = 0.44), and overall response rate (29 vs. 26%, p = 0.71) were not significantly different for the oFFX and mFFX groups. Thrombopenia and liver dysfunction were significantly more frequent with oFFX than with mFFX. The median received dose intensity of CPT-11 was higher with oFFX than with mFFX (299 vs. 270 mg/m2/week, p < 0.01). The propensity score-adjusted analysis revealed no statistically significant differences in OS and PFS between the two groups. CONCLUSION: In our data, there was no significant difference in efficacy between mFFX and oFFX, and mFFX has fewer adverse events.

Effects of Sprayable, Highly Adhesive Hydrophobized Gelatin Microparticles on Endoscopic Submucosal Dissection: A Swine Model.

INTRODUCTION: Sprayable wound dressings containing hydrophobized microparticles (hMPs) are characterized by strong adhesiveness. We examined the effect of hMPs derived from Alaska pollock gelatin on endoscopic submucosal dissection (ESD) ulcers. METHODS: (1) In an in vivo model of miniature swine gastric ESD, gastric ulcers were created by ESD and then sprayed with hMPs or untreated followed by microscopic examination. (2) In an ex vivo ESD model of resected stomach, a pinhole-shaped perforation was created on the ESD ulcer of resected stomach; hMPs were then sprayed on the perforation; and air leakage and intragastric pressure were measured. (3) In an in vivo duodenal ESD model of miniature swine, duodenal artificial ESD ulcers with pinhole-shaped perforation were examined; ulcers were classified into hMPs-sprayed and nonsprayed groups, and inflammation in the intrinsic muscle layer and serosa were compared between the groups. RESULTS: (1) Histological observation of submucosal tissues showed a decreased number of invading inflammatory cells in hMP-sprayed tissues compared with the control in miniature swine gastric ESD (p < 0.05). In addition, the rates of anti-alpha smooth muscle actin and type I collagen positivity were significantly lower in the hMPs group than in the control group (p < 0.05). (2) Intragastric pressure could not be measured in the nonsprayed group, whereas no air leakage was observed in the sprayed group when pressurized up to 26 mm Hg in the resected stomach model. (3) The sprayed group showed suppressed inflammation of the intrinsic muscular layer and serosa in both cases compared with the nonsprayed group in miniature swine duodenal ESD (p < 0.05). CONCLUSIONS: Sprayable, tissue-adhesive hMPs are a promising medical material for intraoperative and postoperative treatment of ESD-induced wound via anti-inflammation and strong adhesiveness.

Scoring model with serum albumin and CA19-9 for metastatic pancreatic cancer in second-line treatment: results from the NAPOLEON study.

BACKGROUND: Patients with metastatic pancreatic cancer refractory to first-line chemotherapy (CTx) have few treatment options. It is unclear what kind of patients could be brought about survival benefit by 2nd-line CTx after refractory to gemcitabine + nab-PTX (GnP) or FOLFIRINOX. METHODS: This analysis was conducted as part of a multicenter retrospective study of GnP or FOLFIRINOX in patients with metastatic pancreatic cancer. Excluding censored cases, 156 and 77 patients, respectively, received second-line chemotherapy (CTx) and best supportive care (BSC). Using prognostic factors for post-discontinuation survivals (PDSs) at the first-line determination in multivariate analysis, we developed a scoring system to demonstrate the benefit of second-line CTx. RESULTS: The second-line CTx group had a median PDS of 5.2 months, whereas the BSC group had a median PDS of 2.7 months (hazard ratio 0.42; 95% confidence interval [CI] 0.31-0.57; p < 0.01). According to the Cox regression model, serum albumin levels below 3.5 g/dL, and CA19-9 levels above 1000 U/mL were independent prognostic factors (p < 0.01). Serum albumin (≥ and < 3.5 g/dL allotted to scores 0 and 1) and CA19-9 (< and ≥ 1000 U/mL allotted to scores 0 and 1) at first-line determination were used to develop the scoring system. The PDSs of patients with scores of 0 and 1 were significantly better than those of the BSC group; however, there was no significant difference between the PDSs of patients with score 2 and the BSC group. CONCLUSION: The survival advantage of second-line CTx, was observed in patients with scores of 0 and 1 but not in those with score 2.

Usefulness of the aldehyde breath test for predicting metachronous recurrence in patients with esophageal squamous cell carcinoma and hypopharyngeal squamous cell carcinoma.

BACKGROUND: The rate of metachronous recurrence after endoscopic submucosal dissection for early-stage esophageal squamous cell carcinoma and hypopharynx squamous cell carcinoma is as high (10-15%). The acetaldehyde breath test may detect acetaldehyde dehydrogenase 2 gene polymorphisms. Therefore, we evaluated its usefulness in assessing metachronous recurrence in patients with esophageal squamous cell carcinoma and hypopharynx squamous cell carcinoma. METHODS: A total of 76 patients underwent endoscopic submucosal dissection for esophageal squamous cell carcinoma and hypopharynx squamous cell carcinoma and were followed up for at least 3 years (non-recurrence group: 52 patients; recurrence group: 24 patients). The risk factors for carcinogenesis were compared between the recurrence and non-recurrence groups, and the acetaldehyde-to-ethanol ratio was assessed. The cutoff acetaldehyde-to-ethanol ratio that correlated with recurrence was established, and the cumulative recurrence rate was evaluated. RESULTS: The recurrence group had a higher acetaldehyde-to-ethanol ratio, daily alcohol consumption, and Lugol-voiding lesion grade than the non-recurrence group in the univariate analysis. The cutoff acetaldehyde-to-ethanol ratio for recurrence was 28.1 based on the receiver operating characteristic curve. The multivariate analysis revealed an acetaldehyde-to-ethanol ratio of > 28.1 and a Lugol-voiding lesion grade associated with carcinogenesis. Patients with an acetaldehyde-to-ethanol ratio of ≥ 28.1 had a significantly high recurrence rate using the Kaplan-Meier method. CONCLUSIONS: The acetaldehyde-to-ethanol ratio detected using the acetaldehyde breath test could be a novel biomarker of metachronous recurrence after endoscopic submucosal dissection in patients with esophageal squamous cell carcinoma and hypopharynx squamous cell carcinoma. TRIAL REGISTRATION NUMBER: UMIN000040615.

Comparing the Efficacy and Safety of Gemcitabine plus Nab-Paclitaxel versus Gemcitabine Alone in Older Adults with Unresectable Pancreatic Cancer.

BACKGROUND: Gemcitabine plus nab-paclitaxel (GnP) has been a standard treatment for unresectable pancreatic cancer (uPC); however, the current treatment status and usefulness in older adults with uPC remain unclear. Therefore, we aimed to investigate the patient background and compare the efficacy and safety of GnP versus other treatments in older adults with uPC. PATIENTS AND METHODS: In this prospective observational study, we enrolled 233 eligible patients aged ≥76 years with pathologically proven, clinically uPC, and no history of chemotherapy from 55 Japanese centers during September 2018-September 2019. The main endpoints were overall survival (OS), progression-free survival (PFS), and safety. Geriatric assessments were performed upon registration and after 3 months. To adjust for confounders, we conducted propensity score-matched analyses. RESULTS: GnP, gemcitabine alone (Gem), best supportive care, and other therapies were administered to 116, 72, 16, and 29 patients, respectively. In the propensity score-matched analysis, 42 patients each were selected from the GnP and Gem groups. The median OS was longer in the GnP group than in the Gem group (12.2 vs. 9.4 months; hazard ratio [HR], 0.65; 95% CI, 0.37-1.13). The median PFS was significantly longer in the GnP group than in the Gem group (9.2 vs. 3.7 months; HR, 0.38; 95% CI, 0.23-0.64). The incidence of severe adverse events was higher with GnP than with Gem; however, the difference was not significant. CONCLUSION: GnP is more efficacious than Gem in patients aged ≥76 years with uPC despite demonstrating a higher incidence of severe adverse events.

Prognostic nomogram for patients with unresectable pancreatic cancer treated with gemcitabine plus nab-paclitaxel or FOLFIRINOX: A post-hoc analysis of a multicenter retrospective study in Japan (NAPOLEON study).

BACKGROUND: No reliable nomogram has been developed until date for predicting the survival in patients with unresectable pancreatic cancer undergoing treatment with gemcitabine plus nab-paclitaxel (GnP) or FOLFIRINOX. METHODS: This analysis was conducted using clinical data of Japanese patients with unresectable pancreatic cancer undergoing GnP or FOLFIRINOX treatment obtained from a multicenter study (NAPOLEON study). A Cox proportional hazards model was used to identify the independent prognostic factors. A nomogram to predict 6-, 12-, and 18-month survival probabilities was generated, validated by using the concordance index (C-index), and calibrated by the bootstrapping method. And then, we attempted risk stratification for survival by classifying the patients according to the sum of the scores on the nomogram (total nomogram points). RESULTS: A total of 318 patients were enrolled. A prognostic nomogram was generated using data on the Eastern Cooperative Oncology Group performance status, liver metastasis, serum LDH, serum CRP, and serum CA19-9. The C-indexes of the nomogram were 0.77, 0.72 and 0.70 for 6-, 12-, and 18-month survival, respectively. The calibration plot showed optimal agreement at all points. Risk stratification based on tertiles of the total nomogram points yielded clear separations of the survival curves. The median survival times in the low-, moderate-, and high-risk groups were 15.8, 12.8 and 7.8 months (P<0.05), respectively. CONCLUSIONS: Our nomogram might be a convenient and inexpensive tool to accurately predict survival in Japanese patients with unresectable pancreatic cancer undergoing treatment with GnP or FOLFIRINOX, and will help clinicians in selecting appropriate therapeutic strategies for individualized management.

Synthesis and Evaluation of Habiterpenol Analogs.

Habiterpenol is a G2 checkpoint inhibitor isolated from the culture broth of Phytohabitans sp. 3787_5. Here, we report the synthesis of new habiterpenol analogs through the total synthesis process of habiterpenol and evaluating the analogs for G2 checkpoint inhibitory activity. We investigated two different synthetic approaches for total synthesis, with intramolecular conjugate addition and Ti(III)-mediated radical cyclization as key reactions. Although the former was unsuccessful, the latter reaction facilitated stereoselective total synthesis and determination of the absolute configuration of habiterpenol. The extension of these chemistries to a structure-activity relationship (SAR) study gave new habiterpenol analogs, which could not be derived from natural habiterpenol and only be synthesized by applying the total synthesis. Therefore, this study provides important insights into SAR studies of habiterpenol.

Pharmacological depletion of retinal neurons prevents vertical angiogenic sprouting without affecting the superficial vascular plexus.

BACKGROUND: In mice, a tri-layered (superficial, intermediate, and deep) vascular structure is formed in the retina during the third postnatal week. Short-term treatment of newborn mice with vascular endothelial growth factor (VEGF) receptor inhibitors delays the formation of superficial vascular plexus and this allows us to investigate the developmental process of superficial and deep vascular plexuses at the same time. Using this model, we examined the effect of pharmacological depletion of retinal neurons on the formation of superficial and deep vascular plexuses. RESULTS: Neuronal cell loss induced by an intravitreal injection of N-methyl-d-aspartic acid on postnatal day (P) 8 delayed vascular development in the deep layer but not in the superficial layer in mice treated with KRN633, a VEGF receptor inhibitor, on P0 and P1. In KRN633-treated mice, neuronal cell loss decreased the number of vertical sprouts originating from the superficial plexus without affecting the number of angiogenic sprouts growing in front. Neuronal cell loss did not impair networks of fibronectin and astrocytes in the superficial layer. CONCLUSIONS: Our results suggest that inner retinal neurons play a crucial role in forming the deep vascular plexus by directing the sprouts from the superficial blood vessels to the deep layer.

Prognostic significance of extracellular volume fraction with equilibrium contrast-enhanced computed tomography for pancreatic neuroendocrine neoplasms.

BACKGROUND: /Objectives: Identifying reliable pretreatment imaging biomarkers for pancreatic neuroendocrine neoplasm (PanNEN) is a key imperative. Extracellular volume (ECV) fraction quantified with equilibrium contrast-enhanced CT can be easily integrated into routine examinations. This study aimed to determine whether ECV fraction with equilibrium contrast-enhanced computed tomography (CECT) could predict long-term outcomes in patients with PanNEN. METHODS: This study was a retrospective observational study of 80 patients pathologically diagnosed with PanNEN at a single institution. ECV fraction of the primary lesion was calculated using region-of-interest measurement within PanNEN and the aorta on unenhanced and equilibrium CECT. The impact of clinical factors and tumor ECV fraction on progression-free survival (PFS) and overall survival (OS) was assessed with univariate and multivariate analyses using Cox proportional hazards models. The correlation between WHO classification and tumor ECV fraction was evaluated using Kendall rank correlation coefficients. RESULTS: PFS and OS rates were estimated as 93.4% and 94.6%, 78.7% and 86.2%, 78.7% and 77.0%, and 78.7% and 66.6% at 1, 3, 5, and 10 years, respectively. Multivariate analysis revealed that Union for International Cancer Control (UICC) stage (hazard ratio [HR] = 3.95, P = 0.003), WHO classification (HR = 12.27, P = 0.003), and tumor ECV fraction (HR = 11.93, P = 0.039) were independent predictors of PFS. Patient age (HR = 1.11, P < 0.001), UICC stage (HR = 3.14, P = 0.001), and tumor ECV fraction (HR = 5.27, P = 0.024) were independent significant variables for predicting OS. Tumor ECV fraction had a weak inverse relationship with WHO classification (P = 0.045, τ = -0.178). CONCLUSIONS: ECV fraction determined by equilibrium CECT and UICC stage may predict survival in patients with PanNEN.

Impairment of endothelium-dependent vasodilator function of retinal blood vessels in adult rats with a history of retinopathy of prematurity.

Retinopathy of prematurity (ROP) is a proliferative retinal vascular disease, initiated by delayed retinal vascular growth after premature birth. In the majority of cases, ROP resolves spontaneously; however, a history of ROP may increase the risk of long-term visual problems. In this study, we evaluated the endothelial function of retinal blood vessels in adult rats with a history of ROP. ROP was induced in rats by subcutaneous injection of a vascular endothelial growth factor receptor tyrosine kinase inhibitor (KRN633) on postnatal day (P) 7 and P8. On P56, vasodilator responses to acetylcholine, GSK1016790A (an activator of transient receptor potential vanilloid 4 channels), NOR3 (a nitric oxide [NO] donor), and salbutamol (a ß2-adrenoceptor agonist) were assessed. Compared to age-matched controls, retinal vasodilator responses to acetylcholine and GSK1016790A were attenuated in P56 rats with a history of ROP. No attenuation of acetylcholine-induced retinal vasodilator response was observed under inhibition of NO synthase. Retinal vasodilator responses to NOR3 and salbutamol were unaffected. These results suggest that the production of and/or release of NO is impaired in retinal blood vessels in adult rats with a history of ROP. A history of ROP might increase the risk of impaired retinal circulation in adulthood.

Covering Post-Endoscopic Submucosal Dissection Ulcers in Miniature Swine with Hexanoyl (Hx:C6) Group-Modified Alkaline-Treated Gelatin Porous Film (HAG) Induces Proper Healing by Decreasing Inflammation and Fibrosis.

BACKGROUND AND AIMS: Hexanoyl (Hx:C6) group-modified alkaline-treated gelatin porous film (HAG) is a newly developed degradable hydrogel characterized by strong adhesiveness and high affinity for vascular endothelial growth factor (VEGF). The aim of this study was to clarify the effect of HAG sheets on the healing process of post-endoscopic submucosal dissection (ESD) porcine gastric artificial ulcers. METHODS: (1) To evaluate the adhesiveness of HAG sheets over time, we performed ESD to create 1 artificial ulcer and covered the lesion with 1 HAG sheet using 1 miniature swine. We observed 2 ulcers by endoscopic and microscopic examinations. (2) To examine the effect of HAG sheets on post-ESD ulcer healing, we performed ESD using 5 miniature swine. The artificial ulcers were covered with HAG sheets, or left uncovered after ESD (day 0), followed by macroscopic and microscopic examinations. On days 7 and 14, we observed 2 ulcers by endoscopic examinations. On day 14, the animals were sacrificed, and histological examination was performed on the 3 stomachs that could be extirpated. RESULTS: (1) On day 7, adhesion of HAG sheets was observed. (2) Gastric ulcer area on day 7 was significantly larger in the covered ulcers than in the non-covered ulcers (p = 0.046). On day 14, although there was no significant difference in ulcer area irrespective of covering (p = 0.357), the covered ulcers tended to repair less fold convergence than non-covered ulcers. The covered ulcer sheets significantly decreased inflammatory cell infiltration (p = 0.011), but significantly increased the abundance of macrophages (p = 0.033), in submucosal layers. Also, the abundance of alpha-smooth muscle actin-positive cells in submucosal layers of the covered ulcers was significantly reduced (p = 0.044), leading to a decrease in collagen accumulation. In addition, fibrosis and atrophy of the muscularis propria were significantly lower for covered ulcers than for non-covered ulcers. Furthermore, microvessels and VEGF-positive cells were significantly more abundant in the submucosal layers of the covered ulcers (p < 0.001 and p = 0.024, respectively). CONCLUSIONS: HAG sheets induced post-ESD ulcer healing with less submucosal inflammation and muscularis propria injury and have the potential to decrease excess scarring.

A multicenter propensity score analysis of FOLFIRINOX vs gemcitabine plus nab-paclitaxel administered to patients with metastatic pancreatic cancer: results from the NAPOLEON study.

PURPOSE: Fluorouracil, leucovorin, irinotecan, and oxaliplatin (FOLFIRINOX, FFX) and gemcitabine plus nab-paclitaxel (GnP) are considered standard treatments for patients with metastatic pancreatic cancer. Direct comparisons are not available that establish which is optimal. METHODS: We conducted a propensity score-adjusted analysis of patients with metastatic pancreatic cancer to identify the therapeutic advantages of these standard therapies. We used clinical data as part of a multicenter retrospective study of patients with unresectable or recurrent pancreatic cancer treated with FFX or GnP (NAPOLEON study). RESULTS: FFX and GnP were initially administered to 102 and 153 patients, respectively. The GnP group comprised more patients of advanced age, worse performance status, lower body mass index, recurrence, and lower albumin concentrations. Median overall survival (OS) and progression-free survival (PFS) were 11.5 months and 5.8 months in the FFX group and 11.1 months and 5.9 months in the GnP group, respectively. Propensity score-adjusted analysis indicated that the administration of FFX or GnP was not independently associated with OS (adjusted hazard ratio [HR] 1.06; 95% confidence interval [CI] 0.76-1.47; P = 0.73). Similarly, the difference in PFS was not significant between groups (adjusted HR 0.93; 95% CI 0.68-1.26; P = 0.62). Gastrointestinal disorders were more common in the FFX group, whereas the frequencies of hematological, nervous system, and skin disorders were higher in the GnP group. CONCLUSION: The efficacies of FFX and GnP were comparable, although safety profiles differed and should be considered in selecting treatment.

The process of revascularization in the neonatal mouse retina following short-term blockade of vascular endothelial growth factor receptors.

Misdirected vascular growth frequently occurs in the neovascular diseases in the retina. However, the mechanisms are still not fully understood. In the present study, we created capillary-free zones in the central and peripheral retinas in neonatal mice by pharmacological blockade of vascular endothelial growth factor (VEGF) signaling. Using this model, we investigated the process and mechanisms of revascularization in the central and peripheral avascular areas. After the completion of a 2-day treatment with the VEGF receptor tyrosine kinase inhibitor KRN633 on postnatal day (P) 4 and P5, revascularization started on P8 in the central avascular area where capillaries had been dropped out. The expression levels of VEGF were higher in the peripheral than in the central avascular area. However, the expansion of the vasculature in the peripheral avascular retina remained suppressed until revascularization had been completed in the central avascular area. Additionally, we found disorganized endothelial cell division, misdirected blood vessels with irregular diameters, and abnormal fibronectin networks at the border of the vascular front and the avascular retina. In the central avascular area, a slight amount of fibronectin as non-vascular component re-formed to provide a scaffold for revascularization. Mechanistic analysis revealed that higher levels of VEGF attenuated the migratory response of endothelial cells without decreasing the proliferative activity. These results suggest that the presence of concentration range of VEGF, which enhances both migration and proliferation of the endothelial cells, and the structurally normal fibronectin network contribute to determine the proper direction of angiogenesis.

Changes in components of the neurovascular unit in the retina in a rat model of retinopathy of prematurity.

An impairment of cellular interactions between the elements of the neurovascular unit contributes to the onset and/or progression of retinal diseases. The present study aims to examine how elements of the neurovascular unit are altered in a rat model of retinopathy of prematurity (ROP). Neonatal rats were treated subcutaneously with the vascular endothelial growth factor (VEGF) receptor tyrosine kinase inhibitor KRN633 (10 mg/kg) on postnatal day (P) 7 and P8 to induce ROP. Morphological assessments were performed of blood vessels, astrocytes and neuronal cells in the retina. Aggressive angiogenesis, tortuous arteries and enlarged veins were observed in the retinal vasculature of KRN633-treated (ROP) rats from P14 to P28, compared to age-matched control (vehicle-treated) animals. Morphological abnormalities in the retinal vasculature showed a tendency toward spontaneous recovery from P28 to P35 in ROP rats. Immunofluorescence staining for glial fibrillary acidic protein and Pax2 (astrocyte markers) revealed that morphological changes to and a reduction in the number of astrocytes occurred in ROP rats. The developmental cell death was slightly accelerated in ROP rats; however, no visible changes in the morphology of retinal layers were observed on P35. The abnormalities in astrocytes might contribute, at least in part, to the formation of abnormal retinal blood vessels and the pathogenesis of ROP.

Visual enhancement pattern during the delayed phase of enhanced CT as an independent prognostic factor in stage IV pancreatic ductal adenocarcinoma.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) has substantial heterogeneity in biophysical features and in outcomes of patients. Identifying reliable pretreatment imaging biomarkers for PDAC with distant metastases (stage IV) is a key imperative. Our objective was to determine whether visual tumor enhancement pattern on enhanced computed tomography (CT) can be used as a prognostic factor in stage IV PDAC treated with chemotherapy. METHODS: This is a retrospective cohort study of 133 patients with stage IV PDAC who underwent multiphasic enhanced CT before systemic chemotherapy. The enhancement pattern of PDAC was qualitatively categorized as hypoattenuation, isoattenuation, or hyperattenuation on each of the pancreatic, portal venous, and delayed phases. The effects of clinical prognostic factors and the visual tumor enhancement pattern on progression-free survival (PFS) and overall survival (OS) were assessed in univariate and multivariate analyses using Cox proportional hazards models. RESULTS: On univariate analysis, the number of metastatic organs and the visual tumor enhancement pattern during the delayed phase were significantly associated with PFS (p = 0.003 and < 0.001, respectively) and OS (p = 0.005 and < 0.001, respectively). Multivariate analysis identified the number of metastatic organs (PFS, p = 0.021; OS, p = 0.041) and visual tumor enhancement pattern during the delayed phase (PFS, p < 0.001; OS, p < 0.001) as independent predictors of PFS and OS. CONCLUSION: Visual enhancement pattern of PDAC on delayed phase enhanced CT appears to be associated with outcomes and could be a useful prognostic factor in stage IV PDAC, despite the need to add the delayed phase to CT protocol for pancreatic disease.

Extracellular volume fraction determined by equilibrium contrast-enhanced dual-energy CT as a prognostic factor in patients with stage IV pancreatic ductal adenocarcinoma.

OBJECTIVES: To evaluate the feasibility of equilibrium contrast-enhanced dual-energy CT (DECT), as compared with single-energy CT (SECT) and to calculate extracellular volume (ECV) fraction to predict the survival outcomes of pancreatic ductal adenocarcinoma (PDAC) patients with distant metastases (stage IV) treated with chemotherapy. METHODS: The study cohort included a total of 66 patients with stage IV PDAC who underwent DECT before systemic chemotherapy between July 2014 and March 2017. Unenhanced and 120-kVp equivalent images during the equilibrium phase were used to calculate tumor SECT-derived ECV fractions, and iodine density images were obtained from equilibrium-phase DECT for DECT-derived ECV fractions. Correlations between SECT- and DECT-derived ECV fractions were identified using the Pearson correlation coefficient and Bland-Altman analysis. The effects of clinical prognostic factors and tumor SECT- and DECT-derived ECV fractions on progression-free survival (PFS) and overall survival (OS) were assessed by univariate and multivariate analyses using Cox proportional hazards models. RESULTS: The correlation between SECT- and DECT-derived ECV fractions was strong (r = 0.965; p < 0.001). The Bland-Altman plot between SECT- and DECT-derived ECV fractions showed a small bias (- 3.4%). Increasing tumor SECT- and DECT-derived ECV fractions were associated with a positive effect on PFS (SECT, p = 0.002; DECT, p = 0.007) and OS (DECT, p = 0.014; DECT, p = 0.015). Only tumor DECT-derived ECV fraction was an independent predictor of PFS (p = 0.018) and OS (p = 0.022) in patients with stage IV PDAC treated with chemotherapy on multivariate analysis. CONCLUSIONS: The ECV fraction determined by equilibrium contrast-enhanced DECT can potentially predict the survival of patients with stage IV PDAC treated with chemotherapy. KEY POINTS: • Extracellular volume fraction of stage IV pancreatic ductal adenocarcinoma determined by dual-energy CT was strongly correlated to that with single-energy CT (r = 0.965, p < 0.001). • Tumor extracellular volume fraction was an independent predictor of progression-free survival (p = 0.018) and overall survival (p = 0.022). • Extracellular volume fraction determined by dual-energy CT could be a useful imaging biomarker to predict the survival of patients with stage IV pancreatic ductal adenocarcinoma treated with chemotherapy.

Abnormal Vascular Phenotypes Associated with the Timing of Interruption of Retinal Vascular Development in Rats.

Pathological angiogenesis is a leading cause of blindness in several retinal diseases. The key driving factor inducing pathological angiogenesis is the pronounced hypoxia leading to a marked, increased production of vascular endothelial growth factor (VEGF). The aim of this study was to determine whether the abnormal vascular growth occurs in a manner dependent on the degree of the vascular defects. Vascular defects of two different degrees were created in the retina by subcutaneously treating neonatal rats with the VEGF receptor (VEGFR) tyrosine kinase inhibitor KRN633 on postnatal day (P) 4 and P5 (P4/5) or P7 and P8 (P7/8). The structure of the retinal vasculature changes was examined immunohistochemically. Prevention of vascular growth and regression of some preformed capillaries were observed on the next day, after completion of each treatment (i.e., P6 and P9). The vascular regrowth occurred as a result of eliminating the inhibitory effect on the VEGFR signaling pathway. KRN633 (P4/5)-treated rats exhibited a retinal vasculature with aggressive intravitreal neovascularization on P21. On the other hand, the appearance of tortuous arteries is a representative vascular pathological feature in retinas of KRN633 (P7/8)-treated groups. These results suggest that an interruption of the retinal vascular development at different time points induces different vascular pathological features in the retina. Pharmacological agents targeting the VEGF signaling pathway are useful for creating an abnormal retinal vasculature with various pathological features in order to evaluate the efficacy of anti-angiogenic compounds.

An Unusual Extender Unit Is Incorporated into the Modular Polyketide Synthase of Scopranones Biosynthesis.

Scopranones, produced by Streptomyces sp. BYK-11038, are the novel bone morphogenetic protein inhibitors characterized by atypical two scoop-like moieties and a 3-furanone moiety. Two scoop-like moieties connected to a 3-furanone have not previously been reported in natural products, and their biosynthesis must occur via a unique pathway. Feeding experiments using 13C-labeled precursors indicated that scopranones were synthesized from three acetates and three butyrates in polyketide-type biosynthesis. Genome mining of Streptomyces sp. BYK-11038 revealed that the candidate biosynthetic gene cluster contains 21 open reading frames (ORFs), including three modular polyketide synthases (PKSs; SprA, SprB, and SprC), which were composed of 4 modules with one loading module and 18 additional ORFs (SprD to SprU) spanning a distance of 55 kbp. The characterization of in-frame deletion mutants and feeding experiments with the predicted extender units indicated that two genes, sprP and sprR, encoding discrete 3-oxoacyl-ACP synthases, and a gene, sprO, encoding crotonyl-CoA reductase, were involved in assembling an unusual C8 branched extender unit, 2-(2-ethylbutyl)malonyl-CoA. Additionally, three ORFs, sprM, sprN, and sprT, encoding cytochrome P450s and a monooxygenase, are important tailoring enzymes in post-PKS modification. SprT is an essential enzyme for decarboxylative ring contraction via oxidation, which converts the 2-pyranone to a 3-furanone.

Hepatocyte Growth Factor Facilitates Esophageal Mucosal Repair and Inhibits the Submucosal Fibrosis in a Rat Model of Esophageal Ulcer.

BACKGROUND/AIMS: Esophageal mucosal damage often causes scar tissue, leading to refractory stricture. The aim of this study was to clarify the effect of hepatocyte growth factor (HGF) on esophageal mucosal repair and fibrosis leading to stricture in a rat model of esophageal ulcer. METHODS: Esophageal ulcers were induced in rats by topical exposure of the lower esophageal serosa to acetic acid, followed by intraperitoneal administration of HGF (200 µg/day) using an osmotic pump for 7 days. The effect of HGF on esophageal mucosal injury was investigated macroscopically and microscopically. The effect of HGF on epithelial cell proliferation and the expression of genes closely associated with the development of fibrosis were also examined. RESULTS: The administration of HGF for 7 days led to a significant reduction in the ulcerative area and enhanced the proliferation of esophageal epithelial cells. HGF treatment significantly decreased the fibrosis, and subsequently attenuated not only the foreshortening but also the narrowing of the esophagus. The expression levels of tissue inhibitor of metalloproteinase (TIMP)-1, -2, and matrix metalloproteinase (MMP)-2, -9 were significantly decreased among rats treated with HGF. CONCLUSION: HGF facilitates the repair of esophageal mucosal injury and may also ameliorate the esophageal fibrosis, possibly through enhanced re-epithelization.