Publications by authors named "Shiro Jimi"

Background and Objectives: Wound healing is commonly associated with critical bacterial colonization or bacterial infection, which induces prolonged inflammation, resulting in delayed re-epithelialization. An appropriate wound dressing requires a humid environment, which also functions as a barrier against bacterial contamination and will accelerate a regenerative response of the wound. Silver sulfadiazine (SSD) is used to prevent wound infection.

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We investigated the drug-resistant mechanisms of intracellular survival of methicillin-resistant (MRSA). Our established MRSA clinical strain, OJ-1, with high biofilm-forming ability, and a macrophage cell line, J774A, were used. After ingestion of OJ-1 by J774A, the cells were incubated for ten days with vancomycin at doses 30 times higher than the minimum inhibitory concentration.

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Hypertrophic scars found on the human body rarely develop in experimental animals, possibly due to their looser skin structure. This makes it difficult to understand the genesis of scar lesions. Therefore, appropriate animal models are urgently needed.

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Collagens act as cellular scaffolds in extracellular matrixes, and their breakdown products may also have important biological functions. We hypothesize that collagen dipeptide Pro-Hyp induces favorable healing activities and examined the effects of Pro-Hyp administered via different routes on wound healing using our novel murine model, in which an advanced fibrosis-prone scar lesion was developed in the abdominal muscle wall under the skin. After excising a part of the abdominal wall, a free-drinking experiment was performed using solutions with casein (CS), high molecular weight collagen peptides (HP), and low molecular weight collagen peptides including Pro-Hyp and Hyp-Gly (LP), in addition to water (HO).

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Skin wounds greatly affect the global healthcare system, creating a substantial burden on the economy and society. Moreover, the situation is exacerbated by low healing rates, which in fact are overestimated in reports. Cutaneous wounds are generally classified into acute and chronic.

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Many cells and soluble factors are involved in the wound healing process, which can be divided into inflammatory, proliferative, and remodeling phases. Fibroblasts play a crucial role in wound healing, especially during the proliferative phase, and show heterogeneity depending on lineage, tissue distribution, and extent of differentiation. Fibroblasts from tissue stem cells rather than from healthy tissues infiltrate wounds and proliferate.

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Negative pressure wound therapy (NPWT) has been commonly used over the years for a wide range of chronic/refractory lesions. Alternatively, autologous micrografting technology is recently becoming a powerful modality for initiating wound healing. The case presented is of a patient with a lower leg ulcer that had responded poorly to NPWT alone for three weeks.

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Methicillin-resistant (MRSA), the most commonly detected drug-resistant microbe in hospitals, adheres to substrates and forms biofilms that are resistant to immunological responses and antimicrobial drugs. Currently, there is a need to develop alternative approaches for treating infections caused by biofilms to prevent delays in wound healing. Silver has long been used as a disinfectant, which is non-specific and has relatively low cytotoxicity.

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Bioengineered materials are widely utilized due to their biocompatibility and degradability, as well as their moisturizing and antibacterial properties. One field of their application in medicine is to treat wounds by promoting tissue regeneration and improving wound healing. In addition to creating a physical and chemical barrier against primary infection, the mechanical stability of the porous structure of biomaterials provides an extracellular matrix (ECM)-like niche for cells.

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: Skin grafting is a method usually used in reconstructive surgery to accelerate skin regeneration. This method results frequently in unexpected scar formations. We previously showed that cutaneous wound-healing in normal mice is accelerated by a micrograft (MG) technique.

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Growth factors and cytokines that are secreted by cells play a crucial role in the complex physiological reaction to tissue injury. The ability to spatially and temporally control their actions to maximize regenerative benefits and minimize side effects will help accelerate wound healing and improve tissue regeneration. In this study, the sequential targeted delivery of growth factor/cytokine combinations with regulatory functions on inflammation and tissue regeneration was examined using an internal splint wound healing model.

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Background: Inappropriate dosing of direct oral anticoagulants (DOACs) has been associated with clinical safety and efficacy; however, little is known about clinical data associated with an inappropriate DOAC dosing in Japan. In addition, there is no report in which the appropriateness of DOAC dosing between prescription for inpatients and for outpatients was examined. In this study, we aimed to investigate the prevalence and factors associated in the inappropriate dosing of DOACs in patients with atrial fibrillation (AF).

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Background: This study aimed to investigate the trends and antimicrobial resistance profile of extended-spectrum β-lactamase-producing (ESBL-EC) clinical isolates.

Methods: A total of 1,303 isolates from January 2012 to December 2017 at Fukuoka University Chikushi Hospital, Japan, were analyzed. The rate of resistance to cefmetazole (CMZ), flomoxef (FMOX), imipenem (IPM), meropenem (MEPM), amikacin (AMK), gentamicin (GM), minocycline (MINO), ciprofloxacin (CPFX), and levofloxacin (LVFX) was compared between non-ESBL-producing (non-ESBL-EC) and ESBL-EC.

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FF-10501 is a novel inhibitor of inosine monophosphate dehydrogenase (IMPDH). Clinical trials of FF-10501 for myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML) are currently being conducted in the United States. Although it has been shown that FF-10501 induces apoptosis in hematological malignant cells, the intracellular mechanisms of this effect have not been characterized.

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Methicillin-resistant Staphylococcus aureus (MRSA) forms biofilms on necrotic tissues and medical devices, and causes persistent infections. Surfactants act on biofilms, but their mode of action is still unknown. If used in the clinic, cytotoxicity in tissues should be minimized.

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A micrograft technique, which minces tissue into micro-fragments >50 μm, has been recently developed. However, its pathophysiological mechanisms in wound healing are unclear yet. We thus performed a wound healing study using normal mice.

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Purpose: Meticillin-resistant Staphylococcus aureus (MRSA) biofilm formation in humans is of serious clinical concern. Previous in vitro studies have been performed with biofilms grown only on inorganic substrates; therefore, we investigated the vancomycin (VCM) resistance of MRSA biofilms grown on skin tissue.

Methodology: We established a novel tissue substrate model, namely MRSA grown on segments of mouse skin tissue (dermal chips, DCs), and compared its resistance capacity against VCM with that of MRSA biofilms grown on plastic chips (PCs).

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Staphylococcus spp. is a major cause of device-related infections. However, the mechanisms of deep-tissue infection by staphylococci from the skin surface remain unclear.

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The mouse excisional dorsal full-thickness wound model with a silicon splint fixed on the skin has been widely used to mimic human wound healing. However, the method cannot accurately quantify dermal remodeling, since the initial point of epithelialization on the wound surface is unclear. To overcome this limitation, we have developed a novel mouse excisional wound model to assess the degree of epithelial extension and regeneration, using a plastic ring-shaped splint fixed beneath the surrounding epidermal tissue.

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Although Staphylococcus aureus is part of the normal body flora, heavy usage of antibiotics has resulted in the emergence of methicillin-resistant strains (MRSA). MRSA can form biofilms and cause indwelling foreign body infections, bacteremia, soft tissue infections, endocarditis, and osteomyelitis. Using an in vitro assay, we screened 173 clinical blood isolates of MRSA and selected 20 high-biofilm formers (H-BF) and low-biofilm formers (L-BF).

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Background/objective: HDL has various atheroprotective functions and improves endothelial function. Apolipoprotein A-I (apoA-I) is a major protein of HDL and plays a crucial role in HDL functions. We developed a novel apoA-I mimetic peptide, FAMP (Fukuoka University ApoA-I Mimetic Peptide).

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Despite the recent development of anti-myeloma drugs, the prognosis of high-risk multiple myeloma remains poor. Therefore, new effective treatment strategies for this disease are needed. It has been reported that high intensity of 18-fluorodeoxyglucose positron emission tomography is high-risk factor in myeloma, suggesting that glucose uptake can be therapeutic target in high-risk myeloma.

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Linezolid is an antimicrobial agent for the treatment of multiresistant Gram-positive infections. A practical high-performance liquid chromatography method was developed for the determination of linezolid in human plasma and saliva. Linezolid and an internal standard (o-ethoxybenzamide) were extracted from plasma and saliva with ethyl acetate and analyzed on a Capcell Pak C18 MG column with UV detection at 254 nm.

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Indwelling foreign-body infections are a critical medical problem, especially in immunocompromised patients. To examine the pathogenicity of biofilm-forming bacteria settling on foreign materials, mice implanted with plastic discs were infected with Staphylococcus aureus. After opening a wide subcutaneous pocket on the dorsal side of mice with or without temporal leukocytopenia, a plastic sheet was placed in the left subcutaneous space; subsequently, bacteria in a planktonic state were dispersed over the subcutaneous space.

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