Structural Analysis of Intracellular Lipid Radicals by LC/MS/MS Using a BODIPY-Based Profluorescent Nitroxide Probe.

Free radical-mediated lipid peroxidation (LPO) induces the formation of numerous lipid radicals, which contribute to the development of several oxidative diseases. To understand the mechanism of LPO in biological systems and the significance of these radicals, identifying the structures of individual lipid radicals is imperative. In this study, we developed an analytical method based on liquid chromatography coupled with tandem mass spectrometry (LC/MS/MS) and a profluorescent nitroxide probe, N-(1-oxyl-2,2,6-trimethyl-6-pentylpiperidin-4-yl)-3-(5,5-difluoro-1,3-dimethyl-3H,5H-5l4-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazaborinin-7-yl)propanamide (BDP-Pen), for the detailed structural analysis of lipid radicals. The MS/MS spectra of BDP-Pen-lipid radical adducts showed product ions and thus allow the prediction of the lipid radical structures and individual detection of isomeric adducts. Using the developed technology, we separately detected the isomers of arachidonic acid (AA)-derived radicals generated in AA-treated HT1080 cells. This analytical system is a powerful tool for elucidating the mechanism of LPO in biological systems.

Prevalence and Viral Loads of Cutaneous Human Polyomaviruses in the Skin of Patients With Chronic Inflammatory Skin Diseases.

BACKGROUND: Human skin microorganisms have been associated with various skin diseases. However, most studies have focused on bacterial communities, and little is known about normally resident skin viruses such as the Polyomaviridae and their association with cutaneous disorders. METHODS: We investigated the infection levels of Merkel cell polyomavirus (MCPyV), human polyomavirus 6 (HPyV6), and human polyomavirus 7 (HPyV7), using triplet skin swabs collected from lesional and nonlesional skins of 86 Japanese patients with inflammatory skin diseases and mycosis fungoides, and from 149 healthy control individuals. RESULTS: This age-matched case-control study provides the first analyses of the loads of polyomaviruses in association with various skin diseases. The viral loads were significantly higher for HPyV6/HPyV7 and lower for MCPyV in patients with psoriasis. The viral load variation was observed not only at lesion sites, but also at clinically unaffected skin sites in most of the patients. The viral strains tested were all of the Asian/Japanese genotype. CONCLUSIONS: Our findings suggest a covariation in the infection levels of cutaneous polyomaviruses in certain inflammatory skin conditions. Worldwide prospective longitudinal studies are warranted to understand the influence of such alterations on the pathogenesis of inflammatory skin disorders.

[Ectopic pulmonary calcification after parathyroidectomy in multiple myeloma].

Ectopic soft tissue calcification (ESTC), a rare clinical condition, causes tissue and organ damage. It is associated with chronic renal failure, hyperparathyroidism, and malignant neoplasms, including multiple myeloma, and it is reportedly resistant to treatment. Here, we present the case of a 71-year-old male with multiple myeloma who had rapid ESTC in the lung. He had developed hypoparathyroidism secondary to thyroidectomy. During the course of our observation, he rapidly developed ectopic pulmonary calcification approximately 2 weeks after acquiring an infection. There was no evidence of further progression of multiple myeloma after the onset of ESTC, and treatment with ferric citrate hydrate and precipitated calcium resulted in immediate improvement of his pulmonary signs. We recommend cautious monitoring for patients with multiple myeloma and hypoparathyroidism to detect the onset of ectopic calcification. In addition, low blood phosphorus levels should be effectively treated.

Ecology of Merkel Cell Polyomavirus in Healthy Skin Among Individuals in an Asian Cohort.

BACKGROUND: Despite the oncogenic potential of Merkel cell polyomavirus (MCPyV), it has been found in the normal skin of healthy individuals; however, little is known about geographical variations in the ecology of MCPyV in this tissue. METHODS: This study included 284 Japanese participants. Sun-unexposed arm and sun-exposed forehead skin swab samples were obtained and analyzed for MCPyV infection, using quantitative polymerase chain reaction. Phylogenetic analyses were also conducted, based on the full-length genes encoding MCPyV large T antigen and viral protein 1. RESULTS: This study provides the first analyses of the age-specific prevalence and levels of MCPyV infection in normal skin. Steep increases in prevalence and viral load were observed in individuals aged >40 years. MCPyV infections with a high viral load were predominantly observed in the foreheads of subjects aged >60 years, among whom a high burden of MCPyV tended to persist. Phylogenetic analyses showed that all of the gene sequences obtained in this study clustered in a major clade, suggesting the existence of an Asian/Japanese genotype. CONCLUSIONS: This large study suggests that MCPyV infection with high viral loads is prevalent in the sun-exposed skin of elderly adults, making it necessary to follow up this cohort for possible transformation of MCPyV to a pathogenetic form.

Selective elimination of tumorigenic cells from mixed culture of normal and tumorigenic cells using hybrid liposomes aimed at realizing of cell therapy.

While induced pluripotent stem (iPS) cells are expected to be a cell source for regenerative medicine, they also have tumorigenic properties owing to their proliferative potential. During the manufacturing of regenerative medicine products, undifferentiated iPS cells and malignant transformed cells may be mixed in the cell culture population. Therefore, it is essential to eliminate tumorigenic cells selectively. In this study, a mixed culture of normal human fetal hepatocytes (Hc cells) and human hepatocellular carcinoma cells (HuH-7 cells) was used as a cell population model to be used as regenerative medicine products, and the selective elimination of HuH-7 cells by hybrid liposomes (HL) was analyzed. HL tended to fuse and accumulate more in HuH-7 cells due to larger fluidity of plasma membrane for HuH-7 cells than that for Hc cells. In a mixed culture of Hc and HuH-7 cells, HL selectively eliminated HuH-7 cells while allowing Hc cells to remain viable. In addition, HL treatment for the mixed culture of Hc and HuH-7 cells suppressed the tumorigenicity of HuH-7 cells. Therefore, HL selectively fused and accumulated in tumorigenic cells in a mixed cell culture of normal and tumorigenic cells, and eliminated tumorigenic cells while allowing normal cells to remain viable. The results of this study suggest the potential of HL in eliminating tumorigenic cells during the manufacturing of regenerative medicine products. Thus, HL could be expected to contribute to the development of safe regenerative medical products. Supplementary Information: The online version contains supplementary material available at 10.1007/s10616-023-00613-y.

Clinical Differentiation of Severe Fever with Thrombocytopenia Syndrome from Japanese Spotted Fever.

Severe fever with thrombocytopenia syndrome (SFTS) and Japanese spotted fever (JSF; a spotted fever group rickettsiosis) are tick-borne zoonoses that are becoming a significant public health threat in Japan and East Asia. Strategies for treatment and infection control differ between the two; therefore, initial differential diagnosis is important. We aimed to compare the clinical characteristics of SFTS and JSF based on symptomology, physical examination, laboratory data, and radiography findings at admission. This retrospective study included patients with SFTS and JSF treated at five hospitals in Nagasaki Prefecture, western Japan, between 2013 and 2020. Data from 23 patients with SFTS and 38 patients with JSF were examined for differentiating factors and were divided by 7:3 into a training cohort and a validation cohort. Decision tree analysis revealed leukopenia (white blood cell [WBC] < 4000/µL) and altered mental status as the best differentiating factors (AUC 1.000) with 100% sensitivity and 100% specificity. Using only physical examination factors, absence of skin rash and altered mental status resulted in the best differentiating factors with AUC 0.871, 71.4% sensitivity, and 90.0% specificity. When treating patients with suspected tick-borne infection, WBC < 4000/µL, absence of skin rash, and altered mental status are very useful to differentiate SFTS from JSF.

High load of Merkel cell polyomavirus DNA detected in the normal skin of Japanese patients with Merkel cell carcinoma.

BACKGROUND: Although Merkel cell polyomavirus (MCPyV) has the potential to cause Merkel cell carcinoma (MCC), it is also found in the normal skin of healthy individuals. However, the mechanism for transformation of MCPyV to an oncogenic form is unknown. OBJECTIVES: To investigate the levels of MCPyV infection in the normal skin patients with MCC compared with those in a control cohort. STUDY DESIGN: We studied a total of six Japanese patients with cutaneous MCC. Sun-exposed and sun-unexposed skin swabs were obtained and analyzed for MCPyV loads using quantitative real-time polymerase chain reaction. RESULTS: At first, we found a patient with MCC carrying an extremely high load of MCPyV DNA in normal skin. This unique case prompted us to further explore the levels of MCPyV as skin microbiota in patients with MCC. We showed that MCPyV DNA levels were significantly higher in swabs obtained from normal skin samples of six patients with MCC compared with those from 30 age-matched healthy individuals and 19 patients with other cutaneous cancers. Whereas MCPyV strains obtained from the normal skin of patients with MCC had gene sequences without structural alterations, sequences of the tumor-derived strains showed truncating mutations or deletions. CONCLUSIONS: Although the number of patients with MCC studied was small, our findings suggest that MCC may occur with a background of high MCPyV load in the skin, and are expected to stimulate further studies on whether such skin virome levels could be one of predictive markers for the development of MCC.

High-performance enantiomer separation of nonsteroidal anti-inflammatory drugs (NSAIDs) by 3 µm reversed-phase chiral columns and application to the optical purity testing of naproxen drug substances and its formulations.

The enantiomer separation of five nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, ketoprofen (KP) and naproxen (NX), which are included in The Japanese Pharmacopoeia 16th edition (JP16), was investigated by employing four kinds of 3 µm reversed-phase chiral columns (AD-3R, AS-3R, OD-3R and OJ-3R). Except for KP, the enantiomers of four NSAIDs were successfully separated by one of the four columns. Among five NSAIDs, only NX has been used as a single enantiomer (S-form, active form) in the clinical field (JP16); therefore, optical purity testing method of NX is required for its quality evaluation. Among four CSPs, the method was developed by using an AS-3R column, which showed good enantioselectivity for NX enantiomers. By optimizing the conditions, the resolution (Rs) of 2.55 was obtained for NX enantiomers within approximately 6 min. The minor enantiomer R-form eluted before the main active enantiomer S-form. Finally, the developed method was applied to the optical purity testing of NX active pharmaceutical ingredients (APIs), and its formulations (tablet and capsule). Other than the minor enantiomer (R-form, inactive form, 0.21 - 0.78%), normal (not chiral) impurities at levels of 0.01-0.3% were simultaneously separated and determined by the method, showing an excellent separation capability of the method for those impurities including the minor enantiomer. The content uniformity test of the NX tablet according to JP16 was also successfully performed by the method with the AS-3R column. Normal phase separation with two chiral columns (AD-H and OD-H) and capillary electrophoretic (CE) separation were also investigated for five NSAIDs enantiomers to discuss the enantioselectivity.

An orbital-selective spin liquid in a frustrated heavy fermion spinel LiV2O4.

The pronounced enhancement of the effective mass is the primary phenomenon associated with strongly correlated electrons. In the presence of local moments, the large effective mass is thought to arise from Kondo coupling, the interaction between itinerant and localized electrons. However, in d electron systems, the origin is not clear because of the competing Hund's rule coupling. Here we experimentally address the microscopic origin for the heaviest d fermion in a vanadium spinel LiV(2)O(4) having geometrical frustration. Utilizing orbital-selective (51)V NMR, we elucidate the orbital-dependent local moment that exhibits no long-range magnetic order despite persistent antiferromagnetic correlations. A frustrated spin liquid, Hund-coupled to itinerant electrons, has a crucial role in forming heavy fermions with large residual entropy. Our method is important for the microscopic observation of the orbital-selective localization in a wide range of materials including iron pnictides, cobaltates, manganites and ruthnates.