An ingenious deep learning approach for pressure injury depth evaluation with limited data.

BACKGROUND: The development of models using deep learning (DL) to assess pressure injuries from wound images has recently gained attention. Creating enough supervised data is important for improving performance but is time-consuming. Therefore, the development of models that can achieve high performance with limited supervised data is desirable. MATERIALS AND METHODS: This retrospective observational study utilized DL and included patients who received medical examinations for sacral pressure injuries between February 2017 and December 2021. Images were labeled according to the DESIGN-R® classification. Three artificial intelligence (AI) models for assessing pressure injury depth were created with a convolutional neural network (Categorical, Binary, and Combined classification models) and performance was compared among the models. RESULTS: A set of 414 pressure injury images in five depth stages (d0 to D4) were analyzed. The Combined classification model showed superior performance (F1-score, 0.868). The Categorical classification model frequently misclassified d1 and d2 as d0 (d0 Precision, 0.503), but showed high performance for D3 and D4 (F1-score, 0.986 and 0.966, respectively). The Binary classification model showed high performance in differentiating between d0 and d1-D4 (F1-score, 0.895); however, performance decreased with increasing number of evaluation steps. CONCLUSION: The Combined classification model displayed superior performance without increasing the supervised data, which can be attributed to use of the high-performance Binary classification model for initial d0 evaluation and subsequent use of the Categorical classification model with fewer evaluation steps. Understanding the unique characteristics of classification methods and deploying them appropriately can enhance AI model performance.

NNC 55-0396, a T-type calcium channel blocker, protects against the brain injury induced by middle cerebral artery occlusion and reperfusion in mice.

We tested whether NNC 55-0396 (NNC), a T-type calcium channel (T-channel) blocker, reduces the brain injury caused by middle cerebral artery occlusion and reperfusion (MCAO/R) in mice. NNC, administered i.c.v. before the occlusion, greatly reduced the MCAO/R-induced brain infarct and neurological dysfunctions, although it, given toward the end of occlusion, was less effective. Systemic administration of NNC before the occlusion also attenuated the infarct and neurological dysfunctions. Our data imply that blood-brain-barrier-permeable T-channel blockers such as NNC are capable of reducing MCAO/R-induced brain damage, and that T-channels are involved in neuronal damage induced by ischemia rather than reperfusion.

Design and synthesis of novel anti-hyperalgesic agents based on 6-prenylnaringenin as the T-type calcium channel blockers.

Since 6-prenylnaringenin (6-PNG) was recently identified as a novel T-type calcium channel blocker with the IC50 value around 1 µM, a series of flavanone derivatives were designed, synthesized and subsequently evaluated for T-channel-blocking activity in HEK293 cells transfected with Cav3.2 T-type channels using a patch-clamp technique. As a result, several new flavanones blocked Cav3.2-dependent T-currents more potently than 6-PNG. In the synthesized compounds, 6-(3-ethylpent-2-enyl)-5,7-dihydroxy-2-(2-hydroxyphenyl)chroman-4-one 8j, 6-(3-ethylpent-2-enyl)-5,7-dihydroxy-2-(4-hydroxyphenyl)chroman-4-one 11b, 6-(2-cyclopentylideneethyl)-5,7-dihydroxy-2-(4-hydroxyphenyl)chroman-4-one 11d, and 6-(2-Cyclopentylethyl)-5,7-dihydroxy-2-(4-hydroxyphenyl)chroman-4-one 12c were more potent blocker than 6-PNG with the IC50 value of 0.39, 0.26, 0.46, and 0.50 µM, respectively. Among the above four derivatives, the compound 8j provided the best result in the in vivo experiments; i.e. systemic administration of 8j at the minimum dose completely restored neuropathic pain induced by partial sciatic nerve ligation in mice.

Prostanoid-dependent bladder pain caused by proteinase-activated receptor-2 activation in mice: Involvement of TRPV1 and T-type Ca2+ channels.

We studied the pronociceptive role of proteinase-activated receptor-2 (PAR2) in mouse bladder. In female mice, intravesical infusion of the PAR2-activating peptide, SLIGRL-amide (SL), caused delayed mechanical hypersensitivity in the lower abdomen, namely 'referred hyperalgesia', 6-24 h after the administration. The PAR2-triggered referred hyperalgesia was prevented by indomethacin or a selective TRPV1 blocker, and restored by a T-type Ca2+ channel blocker. In human urothelial T24 cells, SL caused delayed prostaglandin E2 production and COX-2 upregulation. Our data suggest that luminal PAR2 stimulation in the bladder causes prostanoid-dependent referred hyperalgesia in mice, which involves the activation of TRPV1 and T-type Ca2+ channels.

A Multi-Redox Responsive Cyanometalate-Based Metallogel.

A TTF-based (TTF=tetrathiafulvalene) tridentate ligand (α-(4'-methyl-4,5-di-n-dodecylthylthiotetrathiafulvalene-5'-ylthio)- α'-[2,2,2-tris(1-pyrazolyl)ethoxy]-p-xylene) (L) with long-chain alkyl moieties was prepared in order to obtain a new multi-redox active gelator based on a mixed-metal octanuclear complex [FeIII4 NiII4 (CN)12 (tp)4 (L)4 ](BF4 )4 (1). The magnetism, electrochemistry, and gelation behavior of 1 were studied and 1,2-dichlorobenzene solutions of 1 are shown to display thermoreversible gelation behavior at room temperature. Furthermore, the gel phase of 1 was shown to undergo room-temperature gel-to-sol transformations induced by both the oxidation and reduction of the gelator complex by F4 TCNQ or [FeII (Cp*)2 ], respectively.

Ubiquitin acetylation inhibits polyubiquitin chain elongation.

Ubiquitylation is a versatile post-translational modification (PTM). The diversity of ubiquitylation topologies, which encompasses different chain lengths and linkages, underlies its widespread cellular roles. Here, we show that endogenous ubiquitin is acetylated at lysine (K)-6 (AcK6) or K48. Acetylated ubiquitin does not affect substrate monoubiquitylation, but inhibits K11-, K48-, and K63-linked polyubiquitin chain elongation by several E2 enzymes in vitro. In cells, AcK6-mimetic ubiquitin stabilizes the monoubiquitylation of histone H2B-which we identify as an endogenous substrate of acetylated ubiquitin-and of artificial ubiquitin fusion degradation substrates. These results characterize a mechanism whereby ubiquitin, itself a PTM, is subject to another PTM to modulate mono- and polyubiquitylation, thus adding a new regulatory layer to ubiquitin biology.

Peripheral HMGB1-induced hyperalgesia in mice: Redox state-dependent distinct roles of RAGE and TLR4.

Nuclear HMGB1 that contains 3 cysteine residues is acetylated and secreted to the extracellular space, promoting inflammation via multiple molecules such as RAGE and TLR4. We thus evaluated and characterized the redox state-dependent effects of peripheral HMGB1 on nociception. Intraplantar (i.pl.) administration of bovine thymus-derived HMGB1 (bt-HMGB1), all-thiol HMGB1 (at-HMGB1) or disulfide HMGB1 (ds-HMGB1) caused long-lasting mechanical hyperalgesia in mice. The hyperalgesia following i.pl. bt-HMGB1 or at-HMGB1 was attenuated by RAGE inhibitors, while the ds-HMGB1-induced hyperalgesia was abolished by a TLR4 antagonist. Thus, nociceptive processing by peripheral HMGB1 is considered dependent on its redox states.

Mechanisms for proteinase-activated receptor 1-triggered prostaglandin E2 generation in mouse osteoblastic MC3T3-E1 cells.

We analyzed signaling mechanisms for prostaglandin E2 (PGE2) production following activation of proteinase-activated receptor-1 (PAR1), a thrombin receptor, in preosteoblastic MC3T3-E1 cells. PAR1 stimulation caused PGE2 release, an effect suppressed by inhibitors of COX-1, COX-2, iPLA2, cPLA2, MAP kinases (MAPKs), Src, EGF receptor (EGFR) tyrosine kinase (EGFR-TK) and matrix metalloproteinase (MMP), but not by an intracellular Ca2+ chelator or inhibitors of PI3 kinase, protein kinase C (PKC) and NF-κB. PAR1 activation induced phosphorylation of MAPKs and upregulation of COX-2. The phosphorylation of p38 MAPK was suppressed by inhibitors of Src and EGFR-TK. The COX-2 upregulation was dependent on ERK, p38, EGFR-TK, Src, and COX-2 itself. PAR1 activation also induced MEK-dependent phosphorylation of cAMP response element binding protein (CREB). All inhibitors of EP1, EP2, EP3 and EP4 receptors suppressed the PAR1-triggered PGE2 release. Exogenously applied PGE2 facilitated PAR1-triggered COX-2 upregulation, but it alone had no effect. Together, the PAR1-mediated PGE2 production in MC3T3-E1 cells appears to involve iPLA2 and cPLA2 for arachidonic acid release, and the MEK/ERK/CREB and Src/MMP/EGFR/p38 pathways for COX-2 upregulation, which is facilitated by endogenous PGE2 formed by COX-2. These signaling mechanisms might underlie the role of the thrombin/PAR1/PGE2 system in the early stage of the bone healing.

Intravenous Administration of Cilostazol Nanoparticles Ameliorates Acute Ischemic Stroke in a Cerebral Ischemia/Reperfusion-Induced Injury Model.

It was reported that cilostazol (CLZ) suppressed disruption of the microvasculature in ischemic areas. In this study, we have designed novel injection formulations containing CLZ nanoparticles using 0.5% methylcellulose, 0.2% docusate sodium salt, and mill methods (CLZnano dispersion; particle size 81 ± 59 nm, mean ± S.D.), and investigated their toxicity and usefulness in a cerebral ischemia/reperfusion-induced injury model (MCAO/reperfusion mice). The pharmacokinetics of injections of CLZnano dispersions is similar to that of CLZ solutions prepared with 2-hydroxypropyl-ß-cyclodextrin, and no changes in the rate of hemolysis of rabbit red blood cells, a model of cell injury, were observed with CLZnano dispersions. In addition, the intravenous injection of 0.6 mg/kg CLZnano dispersions does not affect the blood pressure and blood flow, and the 0.6 mg/kg CLZnano dispersions ameliorate neurological deficits and ischemic stroke in MCAO/reperfusion mice. It is possible that the CLZnano dispersions will provide effective therapy for ischemic stroke patients, and that injection preparations of lipophilic drugs containing drug nanoparticles expand their therapeutic usage.

Discovery of N-substituted 7-azaindoline derivatives as potent, orally available M1 and M4 muscarinic acetylcholine receptors selective agonists.

We designed and synthesized novel N-substituted 7-azaindoline derivatives as selective M1 and M4 muscarinic acetylcholine receptors (mAChRs) agonists. Hybridization of compound 2 with the HTS hit compound 5 followed by optimization of the N-substituents of 7-azaindoline led to identification of compound 1, which showed highly selective M1 and M4 mAChRs agonistic activity, weak human ether-a-go-go related gene inhibition, and good bioavailability in multiple animal species.

Lability-controlled syntheses of heterometallic clusters.

A bulky bidentate ligand was used to stabilize a macrocyclic [Fe(III)8Co(II)6] cluster. Tuning the basicity of the ligand by derivatization with one or two methoxy groups led to the isolation of a homologous [Fe(III)8Co(II)6] species and a [Fe(III)6Fe(II)2Co(III)2Co(II)2] complex, respectively. Lowering the reaction temperatures allowed isolation of [Fe(III)6Fe(II)2Co(III)2Co(II)2] clusters with all three ligands. Temperature-dependent absorption data and corresponding experiments with iron/nickel systems indicated that the iron/cobalt self-assembly process was directed by the occurrence of solution-state electron-transfer-coupled spin transition (ETCST) and its influence on reaction intermediate lability.

Glottis Recognition Software Development Using Artificial Intelligence.

The use of video laryngoscopes has enhanced the visualization of the vocal cords, thereby improving the accessibility of tracheal intubation. Employing artificial intelligence (AI) to recognize images obtained through video laryngoscopy, particularly when marking the epiglottis and vocal cords, may elucidate anatomical structures and enhance anatomical comprehension of anatomy. This study investigates the ability of an AI model to accurately identify the glottis in video laryngoscope images captured from a manikin. Tracheal intubation was conducted on a manikin using a bronchoscope with recording capabilities, and image data of the glottis was gathered for creating an AI model. Data preprocessing and annotation of the vocal cords, epiglottis, and glottis were performed, and human annotation of the vocal cords, epiglottis, and glottis was carried out. Based on the AI's determinations, anatomical structures were color-coded for identification. The recognition accuracy of the epiglottis and vocal cords recognized by the AI model was 0.9516, which was over 95%. The AI successfully marked the glottis, epiglottis, and vocal cords during the tracheal intubation process. These markings significantly aided in the visual identification of the respective structures with an accuracy of more than 95%. The AI demonstrated the ability to recognize the epiglottis, vocal cords, and glottis using an image recognition model of a manikin.

Aggregation-induced enhanced fluorescence emission of chiral Zn(II) complexes coordinated by Schiff-base type binaphthyl ligands.

A pair of novel chiral Zn(II) complexes coordinated by Schiff-base type ligands derived from BINOL (1,1'-bi-2-naphthol), R-/S-Zn, were synthesized. X-ray crystallography revealed the presence of two crystallographically independent complexes; one has a distorted trigonal-bipyramidal structure coordinated by two binaphthyl ligands and one disordered methanol molecule (molecule A), while the other has a distorted tetrahedral structure coordinated by two binaphthyl ligands (molecule B). Numerous CH⋯π and CH⋯O interactions were identified, contributing to the formation of a 3-dimensional rigid network structure. Both R-/S-Zn exhibited fluorescence in both CH2Cl2 solutions and powder samples, with the photoluminescence quantum yields (PLQYs) of powder samples being twice as large as those in solutions, indicating aggregation-induced enhanced emission (AIEE). The AIEE properties were attributed to the restraint of the molecular motion arising from the 3-dimensional intermolecular interactions. CD and CPL spectra were observed for R-/S-Zn in both solutions and powders. The dissymmetry factors, gabs and gCPL values, were within the order of 10-3 to 10-4 magnitudes, comparable to those reported for chiral Zn(II) complexes in previous studies.

Identification of N-substituted 8-azatetrahydroquinolone derivatives as selective and orally active M(1) and M(4) muscarinic acetylcholine receptors agonists.

We designed and synthesized N-substituted 8-azatetrahydroquinolone derivatives as selective M1 and M4 muscarinic acetylcholine receptors agonists. Optimization of selected derivatives led to the discovery of compound 7 as a highly potent M1 and M4 agonist with weak hERG inhibition. Oral administration of compound 7 improved psychosis-like behavior in rats.

Design, synthesis and structure-activity relationship of novel tricyclic benzimidazolone derivatives as potent 18 kDa translocator protein (TSPO) ligands.

The 18 kDa translocator protein (TSPO) was identified as a discrete receptor for diazepam (1). Since TSPO in the central nervous system (CNS) is believed to regulate neurosteroids biosynthesis, selective TSPO ligands are expected to be useful in the treatment of psychiatric disorders. We synthesized three novel tricyclic benzimidazolone derivatives, and selected the dihydroimidazoquinolinone derivative 27 as a lead TSPO ligand. Study of the structure-activity relationship (SAR) of dihydroimidazoquinolinone derivatives revealed compounds with potent affinity for TSPO (subnanomolar K(i) values), but poor metabolic stability. The optimization of these compounds led to compound 48 with potent affinity for TSPO and good in vitro PK profile.

Contribution of TRPA1 as a downstream signal of proteinase-activated receptor-2 to pancreatic pain.

We examined if TRPA1, like TRPV1, contributes to pancreatic nociceptor excitation following proteinase-activated receptor-2 (PAR2) stimulation and to pancreatitis-related pain in mice. A PAR2-activating peptide, infused into the pancreatic duct, caused spinal Fos expression, which was prevented by AP18, a TRPA1 inhibitor. Repeated administration of cerulein caused referred hyperalgesia accompanying pancreatitis, which was reversed by SB366791, a TRPV1 inhibitor, but not AP18. AP18, administered in combination with a subeffective dose of SB366791, significantly suppressed the referred hyperalgesia. Our findings suggest that TRPA1, like TRPV1, mediates PAR2-triggered pancreatic nociception and that TRPA1 in collaboration with TRPV1 latently contributes to pancreatitis-related pain.

Antihyperalgesic effect of buprenorphine involves nociceptin/orphanin FQ peptide-receptor activation in rats with spinal nerve injury-induced neuropathy.

We evaluated the effect of buprenorphine, a mixed agonist for µ-opioid receptors and nociceptin/orphanin FQ peptide (NOP) receptors, in neuropathic rats, using the paw pressure test. Buprenorphine, administered i.p. at 50, but not 20, µg/kg, exhibited naloxone-reversible analgesic activity in naïve rats. In contrast, buprenorphine at 0.5 - 20 µg/kg produced a naloxonesensitive antihyperalgesic effect in the L5 spinal nerve-injured neuropathic rats. Intrathecal injection of [N-Phe(1)]nociceptin(1-13)NH2, a NOP-receptor antagonist, reversed the effect of buprenorphine in neuropathic rats, but not in naïve rats. Together, buprenorphine suppresses neuropathic hyperalgesia by activating NOP and opioid receptors, suggesting its therapeutic usefulness in treatment of neuropathic pain.

Inhibition by hydrogen sulfide of rabbit platelet aggregation and calcium mobilization.

Hydrogen sulfide (H2S), a gasotransmitter, plays a variety of roles in the mammalian body including the cardiovascular system. Given evidence that H2S donors including NaHS inhibit human platelet aggregation, we examined and characterized the effects of NaHS on rabbit platelet aggregation and cytosolic Ca(2+) mobilization. Rabbit platelet aggregation was determined in platelet-rich plasma (PRP) and washed platelets. Intracellular Ca(2+) levels were monitored in Fura2-loaded washed platelets. NaHS prevented rabbit platelet aggregation induced by collagen or ADP, and the effective concentration range of NaHS was 0.1-0.3 mM in PRP and 1-3 mM in washed platelets. In washed platelets, NaHS attenuated cytosolic Ca(2+) mobilization induced by collagen or ADP and also reduced platelet aggregation induced by ionomycin, a Ca(2+) ionophore. The anti-platelet effect of NaHS was blocked by an adenylyl cyclase inhibitor and enhanced by a phosphodiesterase inhibitor. H2S thus suppresses rabbit platelet aggregation by interfering with both upstream and downstream signals of cytosolic Ca(2+) mobilization in a cAMP-dependent manner.

5-HT depletion, but not 5-HT1A antagonist, prevents the anxiolytic-like effect of citalopram in rat contextual conditioned fear stress model.

OBJECTIVE: Selective serotonin reuptake inhibitors (SSRIs) have been widely used in the treatment of most anxiety disorders. In this study, to clarify the mechanism of the anxiolytic effect, we investigated the mechanism underlying the effect of the SSRI citalopram on rat contextual conditioned fear stress (CFS), an animal model of anxiety. METHODS: Rats individually received footshocks in a shock chamber. More than 1 day later, they were given citalopram and/or dl-p-chlorophenylalanine (PCPA), various subtype-selective serotonin (5-HT) receptor antagonists: the 5-HT1A receptor antagonist WAY 100635, the 5-HT2A receptor antagonist MDL 100907, the 5-HT2C receptor antagonist SB 242084, the 5-HT3 receptor antagonist tropisetron, the 5-HT4 receptor antagonist GR 125487, the 5-HT6 receptor antagonist SB 258585 or the 5-HT7 receptor antagonist SB 269970. After drug administration, freezing behaviour, which was used as an index of anxiety, was analysed in the same shock chamber without shocks. RESULTS: Citalopram dose dependently reduced conditioned freezing behaviour. The anxiolytic-like effect of citalopram was prevented completely by pretreatment with the 5-HT-depleting agent PCPA, but not by the 5-HT1A receptor antagonist WAY 100635. Furthermore, none of the subtype-selective 5-HT receptor antagonists significantly affected conditioned freezing or affected the anxiolytic-like effect of citalopram. CONCLUSION: The anxiolytic-like effect of citalopram in contextual CFS model depends on 5-HT availability. In addition, contextual CFS model is suggested to be completely different from conventional anxiety models in neural mechanism or manners of serotonergic involvement. However, further studies are needed to identify the pharmacological mechanisms responsible for the anxiolytic-like effect of citalopram.

Aggregation-induced circularly polarized phosphorescence of Pt(II) complexes with an axially chiral BINOL ligand.

A pair of chiral Pt(II) complexes coordinated by simple BINOL and bipyridine ligands displaying aggregation-induced phosphorescence and circularly polarized luminescence were characterized by X-ray crystallography and absorption and emission spectroscopies. The emission of the powder sample was reddish whereas the thin film dispersed in PMMA (fPf = 1 wt%) exhibited a white emission.