Nonbrain metastases seen on magnetic resonance imaging during metastatic brain tumor screening.

Although metastases found during head magnetic resonance imaging (MRI) are not limited to metastatic brain tumors, the MRI is a very common method for "brain metastasis screening," a modality that is being increasingly performed. In this review, we describe MRI findings of nonbrain metastases and discuss ways to avoid missing these lesions. Metastatic cranial bone tumors are among the most common nonbrain metastatic lesions found on head MRI, followed by leptomeningeal carcinomatosis. The other less-frequent metastatic lesions include those in the ventricle/choroid plexus, the pituitary gland and stalk, and the pineal gland. Metastases in the head and neck area, as well as cranial and intracranial lesions, should be carefully evaluated. Furthermore, direct geographical invasion, perineural spread, and double cancers should also be considered. While it is important to recognize these metastatic lesions on MRI, because they may necessitate a change in treatment strategy that could lead to an improvement in prognosis due to early introduction of therapy, nonbrain lesions should also be given greater attention, given the increasing survival of patients with cancer and advances in MRI technology, such as contrast-enhanced-3D T1-weighted imaging.

Deep learning algorithm for detection of aortic dissection on non-contrast-enhanced CT.

OBJECTIVES: To develop a deep learning-based algorithm to detect aortic dissection (AD) and evaluate the diagnostic ability of the algorithm compared with those of radiologists. METHODS: Included in the study were 170 patients (85 with AD and 85 without AD). An AD detection algorithm was developed using a convolutional neural network with Xception architecture. Of the patient data, 80% were used for training and validation and 20% were used for testing. Fivefold cross-validation was performed to evaluate the method. An average of 6688 non-contrast-enhanced CT images (slice thickness, 5 mm) were used for training. A radiologist reviewed both contrast-enhanced and non-contrast-enhanced images and identified the slices of AD. The identified slices were used as ground truth. Receiver operating characteristic curve and area under the curve (AUC) analysis was performed. Five radiologists independently evaluated the images. The accuracy, sensitivity, and specificity of the algorithm and those of the radiologists were compared. RESULTS: The AUC of the developed algorithm was 0.940, and a cutoff value of 0.400 provided accuracy of 90.0%, sensitivity of 91.8%, and specificity of 88.2%. For the radiologists, median (range) accuracy, sensitivity, and specificity were 88.8 (83.5-94.1)%, 90.6 (83.5-94.1)%, and 94.1 (72.9-97.6)%, respectively. There was no significant difference in performance in terms of accuracy, sensitivity, or specificity between the algorithm and the average performance of the radiologists (p > 0.05). CONCLUSIONS: The developed algorithm showed comparable diagnostic performance to radiologists for detecting AD, which suggests the potential of the proposed method to support clinical practice by reducing missed ADs. KEY POINTS: • A deep learning-based algorithm for detecting aortic dissection was developed using the non-contrast-enhanced CT images of 170 patients. • The algorithm had an AUC of 0.940 for detecting aortic dissection. • The accuracy, sensitivity, and specificity of the algorithm were comparable to those of radiologists.

Pyrazolo[4,3-d]pyrimidine Derivatives as a Novel Hypoxia-Inducible Factor Prolyl Hydroxylase Domain Inhibitor for the Treatment of Anemia.

Inhibition of hypoxia-inducible factor prolyl hydroxylase domain (HIF-PHD) promotes erythropoietin (EPO) production by stabilizing the HIFα subunit. Thieno[2,3-d]pyrimidine 8 identified based on X-ray crystal structure analysis was optimized to lead to the discovery of pyrazolo[4,3-d]pyrimidine 13 as the lead compound of orally bioavailable HIF-PHD inhibitors. Conversion of the benzyl moiety in 13 gave pyrazolopyrimidine 19 with high solubility and bioavailability, which increased hemoglobin levels in anemic model rats after repeated oral administration. It was shown that pyrazolo[4,3-d]pyrimidine derivatives are promising therapeutic agents for renal anemia through the inhibition of HIF-PHD.

Five-year follow-up two-dimensional speckle tracking echocardiography in a juvenile with a double-chambered left ventricle.

Double-chambered left ventricle (DCLV) is a particularly rare congenital entity characterized by the presence of two ventricular cavities separated by an abnormal muscle band. An asymptomatic 15-year-old boy was referred to our hospital because of electrocardiographic (ECG) abnormalities. His initial transthoracic echocardiography (TTE) demonstrated a DCLV with mild left ventricular systolic dysfunction. During a 5-year follow-up period, he remained symptom free with no changes in ECG and conventional TTE findings. However, two-dimensional speckle tracking echocardiography revealed a subtle progressive deterioration of left ventricular systolic function during the 5-year follow-up.

Intravenous nicorandil for treatment of the urgent phase acute heart failure syndromes: A randomized, controlled trial.

BACKGROUND: Vasodilators, such as nitroglycerin, have long been first-line treatments for acute heart failure syndromes (AHFS). Nicorandil is a vasodilator with dual potassium channel opening and nitrate properties. However, there are no randomized controlled studies of intravenous nicorandil safety and efficacy in the urgent phase AHFS. We examined the symptomatic, hemodynamic, and echocardiographic effects and safety, and 60-day clinical outcomes of intravenous nicorandil, in addition to standard therapy, in patients with AHFS in the urgent phase. METHODS: In this prospective, randomized controlled trial, 106 AHFS patients were randomized within one hour of arrival to receive either standard therapy (control group, n=56) or standard therapy plus simultaneous intravenous nicorandil (0.2 mg/kg bolus followed by 0.2 mg/kg/h for 24 h; nicorandil group, n=50). Outcomes were assessed at 60 days. RESULTS: Patients in the nicorandil group exhibited greater improvement of dyspnea as measured by change in a five-point Likert scale compared to those in the control group (after 1 h infusion: p=0.006, 6 h; p<0.001). The nicorandil group also showed significantly improved E/e', an estimate of left ventricular filling pressure, at 1 and 24 h ( p=0.001 and p=0.004, respectively). In addition, intravenous nicorandil therapy was safe and did not cause side effects such as excessive hypotension or reflex tachycardia. However, it did not reduce all-cause mortality and readmission rates at 60 days. CONCLUSIONS: Addition of intravenous nicorandil to standard therapy for urgent phase AHFS improved dyspnea and left ventricular diastolic function but not 60-day outcome.

Beneficial effects of intracoronary nicorandil on microvascular dysfunction after primary percutaneous coronary intervention: demonstration of its superiority to nitroglycerin in a cross-over study.

PURPOSE: In patients undergoing primary percutaneous coronary intervention (PCI) for the treatment of ST-segment elevation myocardial infarction (STEMI), coronary microvascular dysfunction is associated with poor prognosis. Coronary microvascular resistance is predominantly regulated by ATP-sensitive potassium (KATP) channels. The aim of this study was to clarify whether nicorandil, a hybrid KATP channel opener and nitric oxide donor, may be a good candidate for improving microvascular dysfunction even when administered after primary PCI. METHODS: We compared the beneficial effects of nicorandil and nitroglycerin on microvascular function in 60 consecutive patients with STEMI. After primary PCI, all patients received single intracoronary administrations of nitroglycerin (250 µg) and nicorandil (2 mg) in a randomized order; 30 received nicorandil first, while the other 30 received nitroglycerin first. Microvascular dysfunction was evaluated with the index of microcirculatory resistance (IMR), defined as the distal coronary pressure multiplied by the hyperemic mean transit time. RESULTS: As a first administration, nicorandil decreased IMR significantly more than did nitroglycerin (median [interquartile ranges]: 10.8[5.2-20.7] U vs. 2.1[1.0-6.0] U, p=0.0002).As a second administration, nicorandil further decreased IMR, while nitroglycerin did not (median [interquartile ranges]: 6.0[1.3-12.7] U vs. -1.4[-2.6 to 1.3] U, p<0.0001). The IMR after the second administration was significantly associated with myocardial blush grade, angiographic TIMI frame count after the procedure, and peak creatine kinase level. CONCLUSION: Intracoronary nicorandil reduced microvascular dysfunction after primary PCI more effectively than did nitroglycerin in patients with STEMI, probably via its KATP channel-opening effect.

Indium-catalyzed synthesis of keto esters from cyclic 1,3-diketones and alcohols and application to the synthesis of seratrodast.

Esterification reactions from cyclic 1,3-diketones and alcohols are carried out in the presence of several Lewis acids. In particular, indium(III) triflate, In(OTf)(3), iron(III) triflate, Fe(OTf)(3), copper(II) triflate, Cu(OTf)(2), and silver(I) triflate, AgOTf, show high catalytic activities. These reactions proceed through the carbon-carbon bond cleavage by a retro-aldol reaction and were found to be highly regioselective even in the presence of other functional groups. This type of reaction can also be applied to the preparation of the keto esters during the synthesis of seratrodast, which is an antiasthmatic and eicosanoid antagonist.

Rhenium- and manganese-catalyzed synthesis of aromatic compounds from 1,3-dicarbonyl compounds and alkynes.

We have succeeded in the development of three approaches to the synthesis of aromatic compounds from 1,3-dicarbonyl compounds and alkynes. The first approach is a manganese-catalyzed [2+2+2] cycloaddition between 1,3-dicarbonyl compounds, which have no substituents at the active methylene moiety, and terminal alkynes. This reaction proceeds with high regioselectivity when aryl acetylenes are employed as the alkyne component. The second approach is a rhenium- or manganese-catalyzed formal [2+1+2+1] cycloaddition between beta-keto esters and two kinds of alkynes. In this reaction, the aromatic compounds are obtained by the following reaction sequence: (1) insertion of the first alkyne into a carbon-carbon single bond of a beta-keto ester, (2) formation of 2-pyranones via intramolecular cyclization with the elimination of ethanol, and (3) Diels-Alder reaction between the formed 2-pyranone and the second alkyne. This reaction provides multisubstituted aromatic compounds in a regioselective manner. The third approach is a rhenium-catalyzed formal [2+2+1+1] cycloaddition reaction from two 1,3-diketones and one alkyne. In this reaction, the aromatic skeleton is constructed from three carbons of the first 1,3-diketone, two carbons of the alkyne, and one carbon of the second 1,3-diketone.

Rhenium- and manganese-catalyzed insertion of alkynes into a carbon-carbon single bond of cyclic and acyclic 1,3-dicarbonyl compounds.

Treatment of alkynes with cyclic and acyclic 1,3-dicarbonyl compounds in the presence of a catalytic amount of a rhenium or manganese complex gives ring-expanded and carbon-chain extension products, respectively. In these reactions, alkynes insert into a non-strained carbon-carbon single bond of 1,3-dicarbonyl compounds. The ring-expansion reaction is also promoted by the addition of 4-A molecular sieves instead of a catalytic amount of an isocyanide.

Rhenium-catalyzed formation of bicyclo[3.3.1]nonene frameworks by a reaction of cyclic beta-keto esters with terminal alkynes.

Treatment of cyclic beta-keto esters with terminal alkynes in the presence of a catalytic amount of a rhenium complex, [ReBr(CO)(3)(thf)](2), gave bicyclo[3.3.1]nonene derivatives. The reaction conditions and yields of the bicyclo[3.3.1]nonenes were improved by the sequential use of tetrabutylammonium fluoride (TBAF) after the rhenium-catalyzed reactions.

Rhenium- and manganese-catalyzed insertion of acetylenes into beta-keto esters: synthesis of 2-pyranones.

Rhenium- and manganese-catalyzed reactions between beta-keto esters and acetylenes, followed by treatment with tetrabutylammonium fluoride, gave 2-pyranone derivatives regioselectively.

Rhenium-catalyzed synthesis of multisubstituted aromatic compounds via C-C single-bond cleavage.

A reaction between a beta-keto ester and an acetylene in the presence of a rhenium complex, [ReBr(CO)3(thf)]2, as a catalyst, provided a 2-pyranone derivative in excellent yield via retro-aldol reaction (C-C single bond cleavage). By adding an acetylene-bearing ester group(s) after the formation of 2-pyranones, an aromatization reaction proceeded and multisubstituted aromatic compounds were obtained in good to excellent yields.

Rearrangement of indene skeletons under mild conditions.

Isomerization between two isomers of 1,2-disubstituted 3-aminoindenes occurs via the rearrangement of indene frameworks. In contrast to previous rearrangements of indene derivatives, which occur under high-temperature conditions or the irradiation of light, this rearrangement proceeds at room temperature without UV light irradiation. An amino group at the 3-position plays an important role to accelerate the rearrangement under mild conditions.

Efficient catalytic insertion of acetylenes into a carbon-carbon single bond of nonstrained cyclic compounds under mild conditions.

A rhenium complex, [ReBr(CO)3(thf)]2, catalyzes the reaction of a 1,3-dicarbonyl cyclic compound with an acetylene to give a medium-sized cyclic compound in excellent yield. By using isocyanide as an additive, the catalytic activity of the rhenium complex changes dramatically, and the insertion of acetylenes into a carbon-carbon single bond occurs under mild conditions. A plausible mechanism is that the reaction proceeds via the formation of a rhenacyclopentene intermediate, ring opening by a retro-aldol reaction, isomerization, and reductive elimination.

Insertion of polar and nonpolar unsaturated molecules into carbon-rhenium bonds generated by C-H bond activation: synthesis of phthalimidine and indene derivatives.

A rhenium complex, [ReBr(CO)(3)(thf)](2), catalyzes the reaction of an aromatic aldimine with an isocyanate and an acetylene to give a phthalimidine and an indene derivative in a quantitative yield, respectively. The reactions proceed via C-H bond activation, insertion of the isocyanate or the acetylene, intramolecular nucleophilic cyclization to the aldimine of the generated amido- or alkenyl-rhenium species, and reductive elimination. In contrast to ruthenium and rhodium catalysts, which are usually employed in this type of reaction, the rhenium catalyst promotes the insertion of a polar unsaturated molecule. This occurs more easily than the insertion of a nonpolar unsaturated molecule.

Rhenium-catalyzed insertion of terminal acetylenes into a C-H bond of active methylene compounds.

[reaction: see text] A rhenium complex, [ReBr(CO)(3)(thf)](2), catalyzed the intermolecular reactions of 1,3-dicarbonyl compounds with terminal acetylenes and gave the corresponding alkenyl derivatives in excellent yields. These reactions could apply to an intramolecular version and gave the corresponding cyclic compounds quantitatively.

Rhenium-catalyzed formation of indene frameworks via C-H bond activation: [3+2] annulation of aromatic aldimines and acetylenes.

A rhenium complex, [ReBr(CO)3(thf)]2, catalyzes the reaction of an aromatic aldimine with an acetylene to give an indene derivative in a quantitative yield. The reaction proceeds via C-H bond activation, insertion of the acetylene, intramolecular nucleophilic cyclization, and reductive elimination. In contrast to ruthenium and rhodium catalysts, which are usually employed in this type of reaction, the rhenium catalyst promotes the intramolecular nucleophilic cyclization of the alkenylmetal species generated by insertion of the acetylene.