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Background: Mean platelet volume (MPV) is regarded as a marker for thrombosis, atherosclerosis, and inflammation in various vascular diseases including stroke. However, it is still unclear whether plasma MPV is associated with cerebral white matter hyperintensities (WMH) and cerebral microvascular pathology in the elderly. Methods: We examined whether MPV level is associated with the presence of cerebral WMH on brain magnetic resonance imaging (MRI) from 870 non-stroke outpatient subjects. The subjects were divided into three groups according to the consecutive level of MPV (low T1, middle T2, and high T3 MPV tertile groups). Demographic data and laboratory data for vascular risk factors were evaluated.Results: Univariate analysis disclosed that old age, hypertension, diabetes mellitus, and low renal function were more prevalent in subjects with higher MPV level. In addition, cerebral WMH were more prevalent in subjects with higher MPV level. After adjusting confounding factors, moderate to severe cerebral WMH were significantly associated with high MPV tertile level. This association remained significant after adjusting for other cerebral vascular pathologies such as large artery atherosclerosis of cerebral arteries, displaying that subjects with middle MPV level (odds ratio (OR): 1.49, 95% confidence interval (95%CI): 1.03-2.15) and those with high MPV level (OR: 1.51, 95%CI: 1.04-2.20) had cerebral WMH lesions more than those with low MPV level. Subjects with more severe cerebral WMH had higher plasma MPV levels than those without (p = 0.02). Conclusions: We found that high MPV level is independently associated with cerebral WMH. This result suggests that platelet activation plays a role in the development of cerebral WMH.

Wolf's isotopic response refers to the occurrence of a novel skin disease at the site of a preceding treated or untreated skin disease. Although the most common preceding skin disease was found to be herpes zoster (HZ), HZ-related dermatological phenomena are not well known in the literature. We report a case of HZ granulomatous dermatitis in a 77-year-old female with a previous history of hypertension, diabetes mellitus, chronic kidney disease, and HZ. She presented with a 3-month history of a pruritic skin lesion on her right thigh. The location of the lesion was consistent with a previous HZ site. Histopathological examination revealed lympho- histiocytic infiltration in the superficial dermis, forming a granulomatous structure. Based on clinical and histopathological findings, we made a diagnosis of granulomatous dermatitis at a previous HZ site. We assumed that the lesion arose from an isotopic response of Wolf. The patient was treated with topical steroids for 3 months and showed clearance of the lesion and symptom. We suggest that treatment should be based on the individual disease, which in our case was topical steroid.

Retinal implants electrically stimulate surviving retinal neurons to restore vision in people blinded by outer retinal degeneration. Although the healthy retina is known to transmit a vast amount of visual information to the brain, it has not been studied whether prosthetic vision contains a similar amount of information. Here, we assessed the neural information transmitted by population responses arising in brisk transient (BT) and brisk sustained (BS) subtypes of ON and OFF retinal ganglion cells (RGCs) in the rabbit retina. To correlate the response heterogeneity and the information transmission, we first quantified the cell-to-cell heterogeneity by calculating the spike time tiling coefficient (STTC) across spiking patterns of RGCs in each type. Then, we computed the neural information encoded by the RGC population in a given type. In responses to light stimulation, spiking activities were more heterogeneous in OFF than ON RGCs (STTCAVG = 0.36, 0.45, 0.77 and 0.55 for OFF BT, OFF BS, ON BT, and ON BS, respectively). Interestingly, however, in responses to electric stimulation, both BT and BS subtypes of OFF RGCs showed remarkably homogeneous spiking patterns across cells (STTCAVG = 0.93 and 0.82 for BT and BS, respectively), whereas the two subtypes of ON RGCs showed slightly increased populational heterogeneity compared to light-evoked responses (STTCAVG = 0.71 and 0.63 for BT and BS, respectively). Consequently, the neural information encoded by the electrically-evoked responses of a population of 15 RGCs was substantially lower in the OFF than the ON pathway: OFF BT and BS cells transmit only ~23% and ~53% of the neural information transmitted by their ON counterparts. Together with previously-reported natural spiking activities in ON RGCs, the higher neural information may make ON responses more recognizable, eliciting the biased percepts of bright phosphenes.

Leuconostoc citreum is a heterofermentative lactic acid bacterium frequently found in the various fermented foods. L. citreum EFEL2700 isolated from Korean kimchi has been used as a host strain for biotechnological applications. For the use as a food-grade host to over-produce food ingredients or enzymes, strong endogenous promoters guarantying high expression levels of target genes are necessary. In this study, transcriptomic analysis of L. citreum EFEL2700 was performed using RNA-Seq and three promoters of the most highly expressed genes were selected: glyceraldehyde 3-phosphate dehydrogenase (G3PD), 6-phosphogluconate dehydrogenase (6PGD), and phosphoketolase (PPK). Thereafter, they were used as promoters to express β-galactosidase gene from Lactobacillus plantarum WCFS1 in L. citreum EFEL2700 and the levels were compared with the control promoter P710 from L. mesenteroides ATCC 8293. As results, the β-galactosidase activities of the transformants were 2.73, 0.27, 37.43, and 9.25 units/mg under the P710, G3PD, 6PGD, and PPK promoters, respectively. The expression level of endogenous promoter 6PGD was superior to the heterologous P710 promoter previously used in a Leuconostoc-Escherichia coli shuttle vector. The 6PGD developed in this study can be used as the most suitable promoter for β-galactosidase expression in L. citreum EFEL2700.

Retinal prostheses use periodic repetition of electrical stimuli to form artificial vision. To enhance the reliability of evoked visual percepts, repeating stimuli need to evoke consistent spiking activity in individual retinal ganglion cells (RGCs). However, it is not well known whether outer retinal degeneration alters the consistency of RGC responses. Hence, here we systematically investigated the trial-to-trial variability in network-mediated responses as a function of the degeneration level. We patch-clamp recorded spikes in ON and OFF types of alpha RGCs from rd10 mice at four different postnatal days (P15, P19, P31, and P60), representing distinct stages of degeneration. To assess the consistency of responses, we analyzed variances in spike count and timing across repeats of the same stimulus delivered multiple times. We found the trial-to-trial variability of network-mediated responses increased considerably as the disease progressed. Compared to responses taken before degeneration onset, those of degenerate retinas showed up to ~70% higher variability (Fano Factor) in spike counts (p < 0.001) and ~95% lower correlation level in spike timing (p < 0.001). These results indicate consistency weakens significantly in electrically-evoked network-mediated responses and therefore raise concerns about the ability of microelectronic retinal implants to elicit consistent visual percepts at advanced stages of retinal degeneration.

Patients presenting with green nail syndrome often show coinfection with fungus. A delay in the accurate diagnosis of coinfection may warrant longer treatment duration. Four patients with green nail syndrome coinfected with fungus were reviewed retrospectively. Fungal culture, cultivating Candida parapsilosis and Candida albicans, was performed in two patients' samples. The mean time of the initiation of treatment for onychomycosis after the first visit was 5.75 weeks. If green nail syndrome is suspected, screening for fungal coinfections and precise management are necessary.

The production of good Meju soybean paste primarily depends on the selection of raw materials and fermenting microorganisms, which together influence its characteristic metabolites, taste, and aroma. In this study, we analyzed the relationship between properties and metabolites in Meju samples fermented by Aspergillus oryzae alone or with Bacillus velezensis. We developed fast-stable processing techniques to obtain Meju from A. oryzae and B. velezensis using the inoculation method, thereby ensuring safety in the production of soybean paste. The amino-type nitrogen content increased from an initial 180–228 mg% to a final 226–776 mg% during fermentation and was higher in Meju inoculated separately with the fungi and bacteria (C group) than in Meju co-inoculated with both the starters concurrently (D group). The levels of metabolites such as glucose, myo-inositol, glycerol, and fatty acids (palmitic, stearic, oleic, and linoleic acids) in Meju fermented by A. oryzae with B. velezensis were higher than those in Meju fermented by A. oryzae alone. Fungal growth was affected by the inoculated bacteria, which often occurs during the fermentation of co-inoculated Meju.

In this study, we examined the potentially beneficial effects of bovine colostrum-derived exosomes on UV-induced aging and damage in three major resident skin cells including keratinocytes, melanocytes, and fibroblasts. The treatment with colostrum exosomes prevented the UV-induced generation of intracellular reactive oxygen species in epidermal keratinocytes. In UV-stimulated melanocytes, colostrum exosomes could also significantly reduce the production of the protective skin-darkening pigment melanin, which may help to reduce the risk of excessive melanin formation causing skin hyperpigmentation disorders. In the human dermal fibroblasts treated with colostrum exosomes, the expression of matrix metalloproteinases was suppressed, whereas increased cell proliferation was accompanied by enhanced production of collagen, a major extracellular matrix component of skin. Taken together, our findings indicate that bovine colostrum-derived exosomes having excellent structural and functional stability offer great potential as natural therapeutic agents to repair UV-irradiated skin aging and damage.

Weissella cibaria is one of the bacteria in charge of the initial fermentation of kimchi and has beneficial effects such as immune-modulating, antagonistic, and antioxidant activities. In our study, we aimed to estimate the safety of W. cibaria JW15 for the use of probiotics according to international standards based on phenotypic (antibiotic resistance, hemolysis, and toxic metabolite production) and genotypic analysis (virulence genes including antibiotic resistance genes). The results of the safety assessment on W. cibaria JW15 were as follows; (1) antibiotic resistance genes (ARGs) (kanamycin and vancomycin etc.) were intrinsic characteristics; (2) There were no acquired virulence genes including Cytolysin (cylA), aggregation substance (asa1), Hyaluronidase (hyl), and Gelatinase (gelE); (3) this strain also lacked β-hemolysis and the production of toxic metabolites (D-lactate and bile salt deconjugation). Consequently, W. cibaria JW15 is expected to be applied as a functional food ingredient in the food market.

Weissella cibaria is one of the bacteria in charge of the initial fermentation of kimchi and has beneficial effects such as immune-modulating, antagonistic, and antioxidant activities. In our study, we aimed to estimate the safety of W. cibaria JW15 for the use of probiotics according to international standards based on phenotypic (antibiotic resistance, hemolysis, and toxic metabolite production) and genotypic analysis (virulence genes including antibiotic resistance genes). The results of the safety assessment on W. cibaria JW15 were as follows; (1) antibiotic resistance genes (ARGs) (kanamycin and vancomycin etc.) were intrinsic characteristics; (2) There were no acquired virulence genes including Cytolysin (cylA), aggregation substance (asa1), Hyaluronidase (hyl), and Gelatinase (gelE); (3) this strain also lacked β-hemolysis and the production of toxic metabolites (D-lactate and bile salt deconjugation). Consequently, W. cibaria JW15 is expected to be applied as a functional food ingredient in the food market.

Leuconostoc citreum EFEL2700 isolated from kimchi was used as a host strain for genetic and metabolic engineering in our previous studies, but the cells of EFEL2700 contained a cryptic plasmid (P-cells). Thus, we created plasmid-free cells (F-cells) using the CRISPR/Cas9 system. In this study, we compared the microbial characteristics of P- and F-cells in terms of growth rate, biochemical properties, transformation efficiency, plasmid copy number and protein expression level. When the growth rate was measured in MRS medium at 30°C, no significant difference (P > 0·01) was observed. Biochemical properties, tested using an API 50CHL kit, showed no differences. Transformation efficiency of F-cells, measured using pCB4270, was higher (1·3 × 104 CFU per μg DNA) than that of P-cells (5·0 × 103 CFU per μg DNA). Copy number after transformation of pCBBgl was 4-fold higher for F-cells than for P-cells. When β-glucosidase activity was assayed in the above experiment, F-cells showed 3·4-fold higher values than P-cells. In conclusion, this study demonstrates that plasmid curing in L. citreum EFEL2700 improves its characteristics as a gene expression host. SIGNIFICANCE AND IMPACT OF THE STUDY: Leuconostoc citreum EFEL2700 (P-cell) isolated from kimchi is a useful food-grade host for expressing heterologous genes. The presence of a cryptic plasmid is thought to limit efficient gene expression. In this study, we compared the microbial and genetic changes after plasmid curing in this strain. The plasmid-free strain showed improved levels of transformation efficiency, copy number and heterologous gene expression without alterations in phenotypes such as the growth rates and biochemical properties. The resulting strain of L. citreum EFEL2701 (F-cell) can be used as an efficient host for genetic engineering.

A 70-year-old female was referred for brown-to-gray colored papules and nodules on her lower legs. She had been diagnosed with diffuse large B-cell lymphoma (DLBCL) in her stomach, and myelodysplastic syndrome (MDS) by bone marrow biopsy. Three years after complete remission of DLBCL, she experienced DLBCL recurrence in her small bowel and was hospitalized. MDS had been stationary, but during the treatment of DLBCL, her laboratory findings suggested signs of leukemia. Bone marrow biopsy was done, and acute monoblastic leukemia (AMoL) was diagnosed. After 1 cycle of chemotherapy for AMoL, skin lesions developed, and her skin biopsy showed cutaneous T-cell lymphoma (CTCL). Terminal deoxynucleotidyl transferase staining and CD123 staining were negative, and bone marrow re-biopsy conducted after the skin lesion developed still showed monoblastic proliferation. Whether the CTCL represented with an AMoL lineage switch could not be completely proved due to the absence of molecular or clonal marker evaluations, but the possibility of coexistence of three different malignancies was higher. During treatment, a neutropenic fever developed, and the patient died due to sepsis. We herein report a rare case of CTCL accompanied by AmoL and DLBCL.

Friction melanosis (FM) is an acquired pigmented disease that is caused by recurrent mechanical stress. There is no previous report explaining the presence of tiny brown-colored particles confined to the corneal layer. We describe a case of a rare form of FM of the finger that showed a relatively transient clinical course. A 17-year-old Korean female presented with a 5-month history of an asymptomatic localized hyperpigmented patch on the tip of the right index finger. The dermoscopic examination revealed homogenous globular pattern, which favored pigmentation over hemorrhage. Histopathologically, hyperkeratosis and acanthosis with lymphohistiocytic infiltration of the superficial dermis were noted on hematoxylin and eosin staining; however, there was neither a definite increase in melanophages in the upper dermis nor melanocytic proliferation in the basal layer. Per high-power field, multiple brown-colored tiny particles were scattered in the corneal layer. The particles were not dyed by Fontana-Masson stain, iron stain, and S-100. We questioned the patient about the presence of irritation and found that she had bought new shoes at the time of the onset. She was habituated to placing her fingers in her shoes while wearing them because they were slightly tight. The lesion disappeared spontaneously a week after the cause of friction was eliminated. Altogether, we encountered a rare form of FM that occurred in a rare location with a transient clinical course. Further cases on pigmentation restricted to finger tips might reveal the origin of the particles.

Leuconostoc citreum is an important lactic acid bacterium used as a starter culture for producing kimchi, the traditional Korean fermented vegetables. An efficient host strain for plasmid transformation, L. citreum EFEL2700, was isolated from kimchi, and it has been frequently used for genetic engineering of L. citreum. In this study, we report the whole genome sequence of the strain and its genetic characteristics. Genome assembly yielded 5 contigs (1 chromosome and 4 plasmids), and the complete genome contained 1,923,830 base pairs (bp) with a G + C content of 39.0%. Average nucleotide identity analysis showed high homology (≥ 99%) to the reference strain L. citreum KM 20. The smallest plasmid (4.3 kbp) was used as an Escherichia coli shuttle vector (pCB) for heterologous gene expression, and L. citreum EFEL2700 showed the highest transformation efficiency, 6.7 × 10⁴ CFU μg−1 DNA. Genetic analysis of the genome enabled the construction of primary metabolic pathway showing a typical hetero-type lactic acid fermentation. Notably, no core genes for primary metabolism were observed in plasmid 4 and it could be eliminated to create an efficient host for gene transformation. This report will facilitate the understanding and application of L. citreum EFEL2700 as a food-grade microbial cell factory.

Leuconostoc spp. are important lactic acid bacteria for the fermentation of foods. In particular, L. citreum strains isolated from various foods have been used as host strains for genetic and metabolic engineering studies. In order to develop a food-grade genetic engineering system, L. citreum CB2567 was isolated from Kimchi. However, the isolated bacterium contained a cryptic plasmid which was difficult to eliminate. As the existence of the plasmid might hinder strain engineering, we eliminated the plasmid using an RNA-guided DNA endonuclease CRISPR/Cas9 system. We demonstrated that a plasmid-free L. citreum CB2567 host strain could be efficiently constructed through a two-step procedure: 1) transformation of the “killer” plasmid expressing Cas9 endonuclease and a guide RNA (gRNA) targeting for a specific sequence in the cryptic plasmid, and 2) serial subculture without antibiotics for curing the killer plasmid. When the crude extract of L. citreum expressing Cas9 and the guide RNA was incubated with a PCR fragment containing the specific sequence recognized by the guide RNA, the PCR fragment was cleaved. Also, the cryptic plasmid pCB42 was successfully eliminated from the host strain after transforming the plasmid harboring Cas9 and the guide RNA. The Cas9 and gRNA expression plasmid used in this study can be applied for genome engineering purposes by additionally introducing an editing DNA template to repair the double strand DNA breakage caused by Cas9 in the genome of L. citreum. This study demonstrates the feasibility of developing CRISPR/Cas9-based genetic engineering tools to develop a safe host strain and construct food-grade lactic acid bacteria without residual antibiotic markers.