Correlations between blood volatile hydrocarbon concentrations in different types of fire-related deaths.

Analysis of volatile hydrocarbons in blood from fire-related deaths provides useful information such as whether the victim inhaled smoke from the fire before death or whether an accelerant was used in the fire. In this study, we used headspace gas chromatography-mass spectrometry to quantify volatile hydrocarbons in post-mortem heart blood from 121 fire victims. The cases were classified into the following four groups according to the detected volatile hydrocarbons: construction fires without accelerants, kerosene fires, gasoline fires, and a group with no fire-related hydrocarbons detected (other fires).

Late-onset non-obstructive mesenteric ischemia (NOMI) resulting from delayed absorption of overdosed antihypertensive drugs: An autopsy case report.

Non-obstructive mesenteric ischemia (NOMI) is caused by reduced blood flow to the intestines without physical occlusion in the mesenteric artery. Previous reports show that drug overdose occasionally induces late-onset NOMI; however, in most cases, the reason for the delayed onset is unclear. Here, we present an autopsy case of late-onset NOMI that was induced by a drug overdose.

Biofunctional supramolecular hydrogels fabricated from a short self-assembling peptide modified with bioactive sequences for the 3D culture of breast cancer MCF-7 cells.

Self-assembling peptides are a type of molecule with promise as scaffold materials for cancer cell engineering. We have reported a short self-assembling peptide, (FFiK), that had a symmetric structure connected via a urea bond. In this study, we functionalized (FFiK) by conjugation with various bioactive sequences for the 3D culture of cancer cells.

Intracellular artificial supramolecules based on de novo designed Y15 peptides.

De novo designed self-assembling peptides (SAPs) are promising building blocks of supramolecular biomaterials, which can fulfill a wide range of applications, such as scaffolds for tissue culture, three-dimensional cell culture, and vaccine adjuvants. Nevertheless, the use of SAPs in intracellular spaces has mostly been unexplored. Here, we report a self-assembling peptide, Y15 (YEYKYEYKYEYKYEY), which readily forms β-sheet structures to facilitate bottom-up synthesis of functional protein assemblies in living cells.

Selection of fluorescent biosensors against galectin-3 from an NBD-modified phage library displaying designed α-helical peptides.

Fluorescent biosensors are indispensable tools for molecular imaging, detection, and drug screening. Conventionally, fluorescent biosensors were constructed by incorporating fluorophores into ligands. Here, to develop ligand-independent biosensors, we demonstrated biosensor selection from a fluorophore-modified peptide phage library.

High blood mirtazapine concentration in a newborn - A case of suspected postpartum infanticide.

We report a sudden death of an infant due to mirtazapine poisoning. A 15-day-old newborn boy was found dead when he was sleeping beside his mother who had suffered from panic disorder for approximately 1 year. After giving birth, she complained of palpitations and shaky hands, and was prescribed mirtazapine.

hDM2 protein-binding peptides screened from stapled α-helical peptide phage display libraries with different types of staple linkers.

Chemically modified peptide ligands were identified from α-helix peptide phage libraries with different types of staple linkers. The hDM2-protein was used as a representative target of protein-protein interactions to screen ligands for p53 binding sites in hDM2. Two types of staple linkers were used for the chemical modification of the peptide phage display libraries before affinity selection.

Construction of a Stapled α-Helix Peptide Library Displayed on Phage for the Screening of Galectin-3-Binding Peptide Ligands.

A stapled α-helix peptide library was designed and constructed using a chemically modified phage display system for screening stapled-peptide ligands against target proteins. The α-helix peptide library, with two cysteine residues on the opposite side of the randomized face, was modified with a rigid hydrocarbon staple linker on a phage. The stapled α-helix peptide phage library was screened against galectin-3 (Gal-3), a cancer-related galactose-binding protein.

Effects of arterial hemorrhage speed on the blood coagulation/fibrinolysis system and hemodynamics in rats.

: The effects of rapid hemorrhage on coagulopathy have been reported. However, the effects of different hemorrhage speeds on the blood coagulation/fibrinolysis system have not been investigated. This study aimed to compare different hemorrhage speeds for clarifying their effects on the coagulation/fibrinolysis system and circulation disorders in rats.

Cerebrospinal fluid neurotransmitter levels and central nervous system depression in a rat drug overdose model.

A neuropsychiatric drug overdose impairs physiological function central nervous system (CNS) depression. In drug-related deaths, only the drug concentration can currently provide information regarding CNS depression in victims. In this study, using a drug overdose model, we investigated the ability of neurotransmitters in the cerebrospinal fluid (CSF) to serve as biomarkers for CNS depression.

Development of a fluvoxamine detection system using a Quenchbody, a novel fluorescent biosensor.

The misuse of psychotropic drugs intended for medical treatment represents a recent worldwide public health concern. Quenchbody (Q-body) is a novel fluoroimmunosensor that can detect an antigen immediately without additional reagents or washing steps. Here, we describe creating Q-bodies for the detection of the antidepressant fluvoxamine (FLV) and determining optimal conditions to achieve the highest fluorescence intensity (FI).

Osteoblastic differentiation on hydrogels fabricated from Ca-responsive self-assembling peptides functionalized with bioactive peptides.

We recently developed an amphiphilic peptide, E1Y9 (Ac-E-YEYKYEYKY-NH), that self-assembles into nanofibers and forms a hydrogel in the presence of Ca ion. Four E1Y9-derivatives (E1Y9-ALK, E1Y9-DGR, E1Y9-PRG and E1Y9-RGD) were designed as conjugates of E1Y9 with bioactive peptide sequences named as ALK (ALKRQGRTLYGF), DGR (DGRDSVAYG), PRG (PRGDSGYRGDS) and RGD (RGDS), respectively, and stimulated osteoblast cells growth as well as differentiation. In this study, E1Y9/E1Y9-derivative mixed hydrogels were constructed to serve as scaffolds for osteoblastic differentiation of MC3T3-E1 cells.

Liquid chromatography-tandem mass spectrometry detection of benzalkonium chloride (BZK) in a forensic autopsy case with survival for 18 days post BZK ingestion.

We report a forensic autopsy case of an elderly man who ingested unknown amount of germicidal disinfectant containing 50% benzalkonium chloride (BZK). He survived for 18 days after BZK ingestion and then died because of pneumonia. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was used to detect three BZK compounds (C-BZK, C-BZK and C-BZK) in the blood.

Gold Nanoparticles Conjugated with Glycopeptides for Lectin Detection and Imaging on Cell Surface.

Background: Lectins are carbohydrate binding proteins and related to various biological events and diseases including virus infection and cancer metastasis. In particular, galactose-binding lectins have attracted attention as targets for drug delivery and cancer markers. We, previously, demonstrated that sugar-modified peptides (glycopeptides) were useful ligands for the detection and characterization of lectins compared to the sugar unit alone.

Screening for concanavalin A binders from a mannose-modified α-helix peptide phage library.

Mannose-modified lectin-binding peptides were obtained from an α-helical-designed peptide phage library. Concanavalin A (ConA) was used as a representative target protein for the lectin family. The identified glycopeptides could selectively bind to ConA with micromolar affinity.

Cell differentiation on disk- and string-shaped hydrogels fabricated from Ca(2+) -responsive self-assembling peptides.

We recently developed a self-assembling peptide, E1Y9, that self-assembles into nanofibers and forms a hydrogel in the presence of Ca(2+) . E1Y9 derivatives conjugated with functional peptide sequences derived from extracellular matrices (ECMs) reportedly self-assemble into peptide nanofibers that enhance cell adhesion and differentiation. In this study, E1Y9/E1Y9-IKVAV-mixed hydrogels were constructed to serve as artificial ECMs that promote cell differentiation.

Dihydrofolate reductase inhibitory peptides screened from a structured designed β-loop peptide library displayed on phage.

Enzyme inhibitory peptides with a loop structure stabilized using an antiparallel β-sheet scaffold (β-loop peptide) were obtained from a designed peptide phage library. Human dihydrofolate reductase (hDHFR) was used as the target enzyme. The obtained β-loop peptides were competitive inhibitors of hDHFR with micromolar inhibition constants and dissociation constants.

Interaction of amphiphilic α-helical cell-penetrating peptides with heparan sulfate.

Cell-penetrating peptides (CPPs) are able to be taken up by cells and can deliver macromolecular cargos. However, the mechanism of this internalization is not yet fully understood. Recent theories suggest that the binding of cationic CPPs to negatively charged extracellular glycosaminoglycans, such as heparan sulfate (HS), is a possible mechanism of cellular uptake (CU).

Cell-selective intracellular drug delivery using doxorubicin and α-helical peptides conjugated to gold nanoparticles.

Cell penetrating peptides (CPPs), which can enter a cell through the cell membrane, have potential research applications in the fields of drug delivery, gene therapy, and cancer therapy. However, CPPs are associated with problems such as low cell selectivity, low cell penetrating activity, and cell toxicity. To overcome the disadvantages of CPPs, we constructed a drug delivery system by developing 25 nm gold nanospheres (GNSs) conjugated to four α-helical CPPs from our peptide library.

Anti-HIV-1 peptide derivatives based on the HIV-1 Co-receptor CXCR4.

The human immunodeficiency virus type 1 (HIV-1) uses CD4 and the co-receptor CCR5 or CXCR4 in the process of cell entry. The negatively charged extracellular domains of CXCR4 (CXCR4-ED) interact with positive charges on the V3 loop of gp120, facilitating binding via electrostatic interactions. The presence of highly conserved positively charged residues in the V3 loop suggests that CXCR4-ED-derived inhibitors might be broadly effective inhibitors.

Self-assembling peptide nanofibers promoting cell adhesion and differentiation.

There is an increasing need for the development of functional artificial extracellular matrices (ECMs) for tissue engineering. Recently, we have successfully designed a self-assembling peptide, named E1Y9, to construct functional ECMs. We describe here an enhancement of abilities of E1Y9 materials to promote cell adhesion and differentiation, using functional peptide sequences derived from natural extracellular matrix proteins.

A monosaccharide-modified peptide phage library for screening of ligands to carbohydrate-binding proteins.

A monosaccharide-modified β-loop peptide library displayed on phage has been constructed and used for the screening of glycopeptide ligands against a carbohydrate-binding protein. The β-loop peptide library was designed and modified with a mannose derivative on phage. The glycopeptide ligands to concanavalin A (ConA), a mannose-binding protein, were obtained from the mannose-modified peptide phage library.

Selective binding of antimicrobial porphyrins to the heme-receptor IsdH-NEAT3 of Staphylococcus aureus.

The Isd (iron-regulated surface determinant) system of the human pathogen Staphylococcus aureus is responsible for the acquisition of heme from the host organism. We recently reported that the extracellular heme receptor IsdH-NEAT3 captures and transfers noniron antimicrobial porphyrins containing metals in oxidation state (III). However, it is unclear if geometric factors such as the size of the metal (ionic radius) affect binding and transfer of metalloporphyrins.

Cell penetration and cell-selective drug delivery using α-helix peptides conjugated with gold nanoparticles.

Cell penetrating peptides (CPPs) have been developed as vectors for molecular delivery into various cells for use in drug delivery, gene therapy and cancer treatment by their property transporting various molecules into cytoplasm. CPPs with high internalization, cell specificity, and low cytotoxicity have been considered to increase the applicability for cell engineering. Gold nanospheres (GNSs) are a useful tool for molecular imaging, because they are non-cytotoxic and have high solubility, ease of synthesis and excellent light scattering property.

Soft materials based on designed self-assembling peptides: from design to application.

Self-assembling peptides (SAPs) are one of the useful tools to fabricate various nanostructures and resulting higher macrostructures from them based on supramolecular chemistry. Recent continuous studies on SAPs give us much important knowledge, from the design of SAPs to their application as nanomaterials and biomaterials. The process from design to application of SAPs includes steps of optimization in self-assembling properties and functionalization.