Cytotoxicity of Silver Nanoparticle and Chitin-Nanofiber Sheet Composites Caused by Oxidative Stress

Size-controlled spherical silver nanoparticles (<10 nm) and chitin-nanofiber sheet composites (Ag NPs/CNFS) have previously been reported to have strong antimicrobial activity in vitro. Although Ag NPs/CNFS have strong antimicrobial activity, their cytotoxicity has not been investigated. This study was performed to evaluate the effects of Ag NPs/CNFS on cytotoxicity for fibroblasts in vitro and healing delay of wound repair in vivo, focused on oxidative stress. Cytotoxic activities of Ag NPs/CNFS were investigated using a fibroblast cell proliferation assay, nitric oxide/nitrogen dioxide (NO/NO2) measurement of the cell lysates in vitro, inhibitory effects of Ag NPs/CNFS on healing-impaired wound repair using diabetic mice in vivo, 8-hydroxy-2′-deoxyguanosine (8-OHdG) immunohistochemical staining of the skin sections, and generation of carbonyl protein in the wound was performed to evaluate cytotoxicity with oxidative stress. Ag NPs/CNFS exhibited cytotoxicity for fibroblasts and a significant increase of total NO/NO2 levels in the cell lysates in vitro and increased levels of 8-OHdG and carbonyl proteins in vivo. Although wound repair in the continuously Ag NPs/CNFS-treated group was delayed, it could be mitigated by washing the covered wound with saline. Thus, Ag NPs/CNFS may become accepted as an anti-infectious wound dressing

Fertility-sparing radical resection of juvenile clear cell adenocarcinoma of the cervix by pneumovaginal endoscopic surgery

Vaginoscopy has been mainly used diagnostically due to the lack of adequate equipment for performing complicated surgeries (Johary et al., 2015). However, herein, we report therapeutic vaginal endoscopic surgery (pneumovaginoscopy) for secondary malignant vaginal tumors using the vNOTES technique and devices (Kita et al., 2021; Yokoe et al., 2022).To our knowledge, this report and surgical video demonstrate the first case of successful fertility-sparing R0 tumor resection of a rare primary cervical clear cell adenocarcinoma using pneumovaginoscopy.A 12-year-old girl was referred to our outpatient clinic with a chief complaint of a genital tumor and possible clear cell carcinoma on biopsy. There was no history of diethylstilbestrol exposure. MRI and CT images suggested a polypoid cervical tumor without metastatic lesions. Therefore, we performed therapeutic pneumovaginoscopic surgery with diagnostic laparoscopy and hysteroscopy.The cervical tumor was resected completely, and hysteroscopy and laparoscopy revealed no abnormalities. The total surgical time was 123 min, and the blood loss volume was minimal. R0 resection was achieved microscopically.Postoperatively, we performed a partial cervical resection around the first surgical scar to confirm no residual tumor.There were no postoperative complications, and a 2-year follow-up revealed no recurrence.The standard treatment for early-stage cervical cancer (IA2-IB1) remains radical hysterectomy with pelvic lymphadenectomy. However, fertility-sparing minimally invasive surgery has recently been introduced for clear cell adenocarcinoma of the cervix (Su et al., 2020). Our report supports the possibility of this minimally invasive surgery under exceptional conditions. This study was approved by the ethics committee of Kansai Medical University. Written and signed informed consent was obtained from the patient’s legal guardian

Bioshell Calcium Oxide-Containing Liquids as a Sanitizer for the Reduction of Histamine Production in Raw Japanese Pilchard, Japanese Horse Mackerel, and Chub Mackerel

Recently, there has been an increase in the number of food poisoning cases associated with histamine in food, mainly in relation to histamine in fish. Here, we investigated methods to decrease histamine levels in Japanese pilchard, Japanese horse mackerel, and chub Mackerel, stored at 10 °C using various concentrations of heated scallop bioshell calcium oxide (BiSCaO) suspension, dispersion (BiSCaO + Na2HPO4), colloidal dispersion (BiSCaO + NapolyPO4), scallop shell powder (SSP) Ca(OH)2 in pure water (PW) or saline, and BiSCaO water. BiSCaO in a high alkaline pH solution chemically decomposes histamine poorly, but the partial flocculation/precipitation of histamine was observed with 1 and 0.2 wt.% BiSCaO dispersion and BiSCaO colloidal dispersion, respectively. Cleaning fish samples with BiSCaO suspension, dispersion, colloidal dispersion, or BiSCaO water remarkably reduced histamine levels and normal bacterial flora (coliform bacteria (CF) and total viable bacterial cells (TC)) after storage for four days at 10 °C, while much higher histamine levels were observed after cleaning with saline. These results suggest that cleaning fish with BiSCaO dispersion, colloidal dispersion, or BiSCaO water can significantly reduce histamine levels through their bactericidal activity against histamine-producing bacteria

Safety of Concentrated Bioshell Calcium Oxide Water Application for Surface and Skin Disinfections against Pathogenic Microbes

Immediately post-production, commercially available bioshell calcium oxide (BiSCaO) water is colorless, transparent, and strongly alkaline (pH 12.8), and is known to possess deodorizing properties and broad microbicidal activity. However, BiSCaO Water may represent a serious safety risk to the living body, given the strong alkalinity. This study aimed to investigate the safety of BiSCaO Water for use as an antiseptic/disinfectant despite concerns regarding its high alkalinity. The change over time in pH of BiSCaO Water was measured during air contact (stirring BiSCaO Water in ambient air). When sprayed on metal, plastic, wood piece, paper, and skin surfaces, the pH of BiSCaO Water decreased rapidly, providing a white powder coating upon drying. Scanning electron microscopy images, energy dispersive X-ray elemental mapping, and X-ray diffractograms showed that the dried powder residues of BiSCaO Water were composed primarily of calcium carbonate. These results suggested that BiSCaO Water is a potent reagent that may overcome the obstacles of being strongly alkaline, making this material appropriate for use in disinfection against pathogenic microbes

Application of Colloidal Dispersions of Bioshell Calcium Oxide (BiSCaO) for Disinfection

Bioshell calcium oxide (BiSCaO) is a scallop-shell powder heated at a high temperature. BiSCaO is composed mainly of calcium oxide and exhibits broad microbicidal properties. The aim of this study is to evaluate the disinfection and decontamination abilities of BiSCaO colloidal dispersions with that of commercially available bioshell calcium hydroxide (BiSCa(OH)2) following the formation of flocculants/precipitates under strongly alkaline conditions (pH 11.5–12.2). Various concentrations of BiSCaO and BiSCa(OH)2 colloidal dispersions were prepared by mixing with Na-polyPO4 (PP) and Na-triPO4 (TP) as flocculating agents. The microbicidal activities, and the degree of flocculation/precipitation of trypan blue, albumin, chondroitin sulfate, heparin, non-anticoagulant heparin carrying polystyrene (NAC-HCPS), and low-molecular-weight heparin/protamine nanoparticles (LMWH/P NPs) were dependent on the pH, the average particle diameter, and the concentration of BiSCaO or BiSCa(OH)2 and of the phosphate compound. BiSCaO (average particle diameter: 6 μm) colloidal dispersions (0.2 wt.%) containing 0.15 wt.% PP or TP exhibited substantially stronger microbicidal activity and flocculation/precipitation under strongly alkaline conditions. These results suggest that BiSCaO colloidal dispersions together with phosphate compounds have practical applicability for disinfection