Cloning, Sequencing, and Functional Analysis of the Biosynthetic Gene Cluster of Macrolactam Antibiotic Vicenistatin in Streptomyces halstedii

AbstractVicenistatin, an antitumor antibiotic isolated from Streptomyces halstedii, is a unique 20-membered macrocyclic lactam with a novel aminosugar vicenisamine. The vicenistatin biosynthetic gene cluster (vin) spanning ∼64 kbp was cloned and sequenced. The cluster contains putative genes for the aglycon biosynthesis including four modular polyketide synthases (PKSs), glutamate mutase, acyl CoA-ligase, and AMP-ligase. Also found in the cluster are genes of NDP-hexose 4,6-dehydratase and aminotransferase for vicenisamine biosynthesis. For the functional confirmation of the cluster, a putative glycosyltransferase gene product, VinC, was heterologously expressed, and the vicenisamine transfer reaction to the aglycon was chemically proved. A unique feature of the vicenistatin PKS is that the loading module contains only an acyl carrier protein domain, in contrast to other known PKS-loading modules containing certain activation domains. Activation of the starter acyl group by separate polypeptides is postulated as well

The Value of Intracoronary Imaging and Coronary Physiology When Treating Calcified Lesions

Heavily calcified coronary artery lesions hinder the delivery of devices and limit stent expansion, resulting in low procedural success and poor clinical outcomes driven by an increase in restenosis and stent thrombosis. Intracoronary imaging provides a more precise assessment of lesions and is a critical step when deciding whether the lesion needs to be prepared with atherectomy devices. Physiological assessment of lesion significance is an important consideration to avoid unnecessary stenting. This article summarises the current data on the value of intracoronary imaging and functional assessment for coronary calcified lesions and suggests a treatment strategy based on the findings of intracoronary imaging findings

Towards a better understanding of the posttreatment hemodynamic behaviors in femoropopliteal arteries through personalized computational models based on OCT images.

The hemodynamic behavior following endovascular treatment of patients with peripheral arterial disease plays a significant role on the occurrence of restenosis in femoro-popliteal (FP) arteries. The atheroprone flow conditions that are generally accepted to promote restenosis can be calculated by computational fluid dynamics (CFD) analyses, and these results can be used to assess individualized treatment outcomes. However, the impact of endovascular therapy on the flow behaviors of FP arteries are still poorly understood, as the imaging modalities used in existing numerical works (X-ray angiography, computed tomography angiography) are unable to accurately represent the post-treatment arterial geometry due to their low resolutions. Therefore, this study proposes a new algorithm that combines intra-arterial lumen geometry obtained from high-resolution optical coherence tomography (OCT) images with centerlines generated from X-ray images to reconstruct the FP artery with an in-plane resolution of 10 µm. This superior accuracy allows modeling characteristic geometrical structures, such as angioplasty-induced arterial dissections, that are too small to be reconstructed with other imaging modalities. The framework is applied on the clinical data of patients treated either with only-percutaneous transluminal angioplasty (PTA) (n = 4) or PTA followed by stenting (n = 4). Based on the generated models, PTA was found to cause numerous arterial dissections, covering approximately 10% of the total surface area of the lumen, whereas no dissections were identified in the stented arteries. CFD simulations were performed to investigate the hemodynamic conditions before and after treatment. Regardless of the treatment method, the areas affected by low time-averaged wall shear stress (< 0.5 Pa) were significantly higher (p < 0.05) following endovascular therapy (pre-PTA: 0.95 ± 0.59 cm2; post-PTA: 2.10 ± 1.09cm2; post-stent: 3.10 ± 0.98 cm2). There were no statistical differences between the PTA and the stent groups. However, within the PTA group, adverse hemodynamics were mainly concentrated at regions created by arterial dissections, which may negatively impact the outcomes of a leave-nothing-behind strategy. These observations show that OCT-based numerical models have great potential to guide clinicians regarding the optimal treatment approach

Smoking cessation is associated with increased plasma adiponectin levels in men

SummaryObjectivesLow levels of adiponectin, an adipocytokine with anti-diabetic and anti-atherogenic properties, are associated with increased risk of future myocardial infarction in men. Previous studies have demonstrated that cigarette smoking is involved in the development of insulin resistance, and current smokers have been shown to have reduced plasma adiponectin levels. However, the influence of smoking cessation on adiponectin levels remains unknown. We sought to assess whether smoking cessation is associated with increased plasma adiponectin levels in men.MethodsThe study includes 72 men (47 non-smokers and 25 current smokers at baseline) with stable angina pectoris who underwent percutaneous coronary intervention and follow-up coronary angiography 6 months later. During the 6-month follow-up period, all 47 non-smokers remained non-smokers, while 15 men of the 25 baseline current smokers successfully quit smoking. We evaluated plasma adiponectin levels at coronary intervention and 6 months later.ResultsPlasma adiponectin levels at coronary intervention were comparable to those after 6 months in non-smokers (4.22 [3.15–6.43] vs. 4.58 [3.03–6.26]μg/mL, P=0.124) and in persistent smokers (4.77 [4.25–10.53] vs. 5.16 [4.11–8.10]μg/mL, P=0.721). Meanwhile, an increase in adiponectin level was observed in patients who quit smoking for 6 months (4.24 [3.30–5.70] vs. 5.50 [4.03–8.00]μg/mL, P=0.002). Univariate analysis revealed that the percent increase in adiponectin levels correlated positively with smoking cessation (P=0.003) and negatively with additional use of β-blockers (P=0.049). In addition, increases in adiponectin levels were closely associated with increase in high-density lipoprotein cholesterol (P=0.148), decrease in triglycerides (P=0.140), and additional use of renin–angiotensin system inhibitors (P=0.069). Multivariate analysis demonstrated that smoking cessation was an independent determinant of the increase in adiponectin (P=0.036).ConclusionsSmoking cessation is associated with increased plasma adiponectin levels in men with stable angina, suggesting that the significance of smoking cessation may be partly explained by the increase in adiponectin level

Comparison of Two Electrosurgical Modes for Endoscopic Submucosal Dissection of Superficial Colorectal Neoplasms: A Prospective Randomized Study

Endoscopic submucosal dissection (ESD) is reportedly one of the standard treatment strategies for large superficial colorectal neoplasms in Japan because of its high en bloc resection rate. A few technical issues regarding ESD should be considered, one of which is the selection of the Endo-cut I mode versus the Swift-coagulation mode as the electrosurgical unit mode setting during submucosal dissection. We seek to determine which of these two modes is more suitable for submucosal dissections of colorectal tumors with regard to procedure time and safety

Self-reported non-adherence to P2Y12 inhibitors in patients undergoing percutaneous coronary intervention: Application of the medication non-adherence academic research consortium classification.

AIMS The Non-adherence Academic Research Consortium (NARC) has recently developed a consensus-based standardized classification for medication non-adherence in cardiovascular clinical trials. We aimed to assess the prevalence of NARC-defined self-reported non-adherence to P2Y12 inhibitors and its impact on clinical outcomes in patients undergoing percutaneous coronary intervention (PCI). METHODS AND RESULTS Using a standardized questionnaire administered at 1 year after PCI, we assessed the 4 NARC-defined non-adherence levels including type, decision-maker, reasons, and timing within the Bern PCI registry. The primary endpoint was the patient-oriented composite endpoint (POCE) defined as a composite of death, myocardial infarction, stroke, and any revascularization at 1 year. The recommended P2Y12 inhibitor duration was 12 months. Among 3,896 patients, P2Y12 inhibitor non-adherence was observed in 647 (17%) patients. Discontinuation was permanent in the majority of patients (84%). The decision was mainly driven by a physician (94%), and rarely by patients (6%). The most frequent reason was risk profile change (43%), followed by unlisted reasons (25%), surgery (17%), and adverse events (14%). Non-adherence occurred early (180 days) in 33%. The majority of POCE events (n = 421/502, 84%) occurred during adherence to the prescribed P2Y12 inhibitor. Permanent discontinuation, doctor-driven non-adherence, and risk profile change emerged as independent predictors for POCE. CONCLUSIONS In real-world PCI population treated with 1-year DAPT, non-adherence was observed in nearly one-fifth of patients. Non-adherence to P2Y12 inhibitors was associated with worse clinical outcomes, while the risk was related to underlying contexts. CLINICALTRIALS.GOV IDENTIFIER NCT02241291

Impact of intracoronary optical coherence tomography in routine clinical practice: A contemporary cohort study.

BACKGROUND/PURPOSE Guidelines recommend intracoronary optical coherence tomography (OCT) to assess stent failure and guide percutaneous coronary intervention (PCI) but OCT may be useful for other indications in routine clinical practice. METHODS/MATERIALS We conducted an international registry of OCT cases at two large tertiary care centers to assess clinical indications and the potential impact on decision making of OCT in clinical routine. Clinical indications, OCT findings, and their impact on interventional or medical treatment strategy were retrospectively assessed. RESULTS OCT was performed in 810 coronary angiography cases (1928 OCT-pullbacks). OCT was used for diagnostic purposes in 67% (N = 542) and OCT-guided percutaneous coronary intervention in 50% (N = 404, 136 cases with prior diagnostic indication). Most frequent indications for diagnostic OCT were culprit lesion identification in suspected ACS (29%) and stent failure assessment (28%). OCT findings in the diagnostic setting influenced patient management in 74%. OCT-guided PCIs concerned ACS patients in 45%. Among the 55% with chronic coronary syndrome, long lesions >28 mm (19%), left main PCI (16%), and bifurcation PCI with side-branch-stenting (5%) were the leading indications for PCI-guidance. Post-procedural OCT findings led to corrective measures in 52% (26% malapposition, 14% underexpansion, 6% edge dissection, 3% intrastent mass, 3% geographic plaque miss). CONCLUSIONS OCT was most frequently performed to identify culprit lesions in suspected ACS, for stent failure assessment, and PCI-guidance. OCT may impact subsequent treatment strategies in two out of three patients

Observer agreement for the diagnosis of intestinal acute graft‑vs.‑host disease based on the presence of villous atrophy in the terminal ileum

Intestinal graft‑vs.‑host disease (GVHD) is a serious complication of allo‑hematopoietic stem cell transplantation (allo‑HSCT). Villous atrophy in the terminal ileum is considered a useful diagnostic indicator for GVHD. However, the inter‑ and intra‑observer agreement regarding the ileocolonoscopic findings indicative of acute intestinal GVHD, i.e., villous atrophy in the terminal ileum, are currently insufficient in multiple institutions. Thus, the present study aimed to investigate the incidence of villous atrophy in the terminal ileum to diagnose acute intestinal GVHD and determine the inter‑ and intra‑observer agreement regarding this result for experienced endoscopists from multiple institutions. Consecutive patients who underwent allo‑HSCT were referred to our institution between May 2008 and September 2015. A total of 54 patients underwent total ileocolonoscopy after allo‑HSCT due to suspected intestinal acute GVHD. Subsequently, three observers from different institutions evaluated the cases for the presence of villous atrophy in the terminal ileum. In this study, the pathology results were a gold standard to evaluate the predictive value of ileocolonoscopy detection. Definitive pathological and non‑pathological GVHD was diagnosed in 22 and 32 cases, respectively. The results of examining whether villous atrophy could predict GVHD were as follows. For three observers (A, B and C), the sensitivity of villous atrophy in the terminal ileum was 86.4, 77.3 and 79.2%, respectively, whereas the specificity was 62.5, 62.5 and 86.7%, respectively. The positive predictive value (PPV) and negative predictive value (NPV) of villous atrophy for GVHD were as follows: The PPV of appearance was 61.3, 58.6 and 82.6%, respectively, whereas the NPV was 87.0, 80.0 and 83.9%, respectively. Kappa coefficients for the inter‑observer reliability were 0.85, 0.63 and 0.63 for observers A and B, A and C, and B and C, respectively. The intra‑observer kappa coefficient was 0.88 for observer A, 0.73 for observer B and 0.75 for observer C. A substantial observer agreement was achieved for the analysis of villous atrophy in the terminal ileum and the agreement for the predictive histological diagnosis was also excellent. Based on the results of the present study, identification of villous atrophy in the terminal ileum was a clinically effective diagnostic parameter, even if different endoscopists were involved in the diagnosis at multiple institutions. The present study was registered as a trial with the University Hospital Medical Information Network (UMIN; registration no. UMIN000025390)

Combined Analysis of Myocardial Deformation and Oxygenation Detects Inducible Ischemia Unmasked by Breathing Maneuvers in Chronic Coronary Syndrome.

Introduction In patients with chronic coronary syndromes, hyperventilation followed by apnea has been shown to unmask myocardium susceptible to inducible deoxygenation. The aim of this study was to assess whether such a provoked response is co-localized with myocardial dysfunction. Methods A group of twenty-six CAD patients with a defined stenosis (quantitative coronary angiography > 50%) underwent a cardiovascular magnetic resonance (CMR) exam prior to revascularization. Healthy volunteers older than 50 years served as controls (n = 12). Participants hyperventilated for 60s followed by brief apnea. Oxygenation-sensitive images were analyzed for changes in myocardial oxygenation and strain. Results In healthy subjects, hyperventilation resulted in global myocardial deoxygenation (-10.2 ± 8.2%, p 0.05), yet this was significant for both myocardial oxygenation [area under the curve (AUC): 0.88, p > 0.001] and peak strain (AUC: 0.73, p = 0.023) measured with apnea. A combined analysis of myocardial oxygenation and peak strain resulted in an incrementally higher AUC of 0.91, p < 0.001 than strain alone. Conclusion In myocardium of patients with chronic coronary syndromes and primarily intermediate coronary stenoses, cine oxygenation-sensitive CMR can identify an impaired vascular and functional response to a vasoactive breathing maneuver stimulus indicative of inducible ischemia

The Selective Arterial Calcium Injection Test is a Valid Diagnostic Method for Invisible Gastrinoma with Duodenal Ulcer Stenosis : A Case Report

The localization and diagnosis of microgastrinomas in a patient with multiple endocrine neoplasia type 1 is difficult preoperatively. The selective arterial calcium injection (SACI) test is a valid diagnostic method for the preoperative diagnosis of these invisible microgastrinomas. We report a rare case of multiple invisible duodenal microgastrinomas with severe duodenal stenosis diagnosed preoperatively by using the SACI test. A 50-year-old man was admitted to our hospital with recurrent duodenal ulcers. His serum gastrin level was elevated to 730 pg/ml. It was impossible for gastrointestinal endoscopy to pass through to visualize the inferior part of the duodenum, because recurrent duodenal ulcers had resulted in severe duodenal stenosis. The duodenal stenosis also prevented additional endoscopic examinations such as endoscopic ultrasonography. Computed tomography did not show any tumors in the duodenum and pancreas. The SACI test provided the evidence for a gastrinoma in the vascular territory of the inferior pancreatic-duodenal artery. We diagnosed a gastrinoma in the peri- ampullary lesion, so we performed Subtotal Stomach-Preserving Pancreatico- duodenectomy with regional lymphadenectomy. Histopathological findings showed multiple duodenal gastrinomas with lymph node metastasis and nonfunctioning pancreatic neuroendocrine tumors. Twenty months after surgery, the patient is alive with no evidence of recurrence and a normal gastrin level. In conclusion, the SACI test can enhance the accuracy of preoperative localization and diagnosis of invisible microgastrinomas, especially in the setting of severe duodenal stenosis