High-Efficiency Single-Cell Containment Microdevices Based on Fluid Control.

In this study, we developed a comb-shaped microfluidic device that can efficiently trap and culture a single cell (bacterium). Conventional culture devices have difficulty in trapping a single bacterium and often use a centrifuge to push the bacterium into the channel. The device developed in this study can store bacteria in almost all growth channels using the flowing fluid. In addition, chemical replacement can be performed in a few seconds, making this device suitable for culture experiments with resistant bacteria. The storage efficiency of microbeads that mimic bacteria was significantly improved from 0.2% to 84%. We used simulations to investigate the pressure loss in the growth channel. The pressure in the growth channel of the conventional device was more than 1400 PaG, whereas that of the new device was less than 400 PaG. Our microfluidic device was easily fabricated by a soft microelectromechanical systems method. The device was highly versatile and can be applied to various bacteria, such as Salmonella enterica serovar Typhimurium and Staphylococcus aureus.

Primary Cutaneous Gamma-Delta T-Cell Lymphoma Initially Diagnosed as Subcutaneous Panniculitis-like T-Cell Lymphoma with Dermatomyositis.

Primary cutaneous gamma-delta T-cell lymphoma (CGD-TCL) is a rare cutaneous lymphoma. Panniculitis-like T-cell lymphoma (SPTCL) has a better prognosis than CGD-TCL. SPTCL is sometimes associated with autoimmune disease. A 64-year-old Japanese female with a history of dermatomyositis presented with subcutaneous nodules on the upper extremities and exacerbated dermatomyositis. A skin biopsy showed lobular panniculitis, a vacuolar interface change, and a dermal mucin deposit. Fat cells rimmed by neoplastic cells, fat necrosis, and karyorrhexis were observed. The atypical lymphoid cells showed CD3+, CD4-, CD8+, granzyme B+, CD20-, and CD56-. Polymerase chain reaction analysis demonstrated a T-cell receptor rearrangement. The patient was initially diagnosed with SPTCL, so the dose of prednisone was raised from 7.5 to 50 mg daily (1 mg/kg). After one month, erythematous nodules regressed, and muscle symptoms improved. Subsequently, prednisone was tapered, and cyclosporin A was added. After one year, the patient remained symptom-free and continued taking 7.5 mg prednisone and 100 mg cyclosporin A daily. Afterward, we immunostained skin samples with antibodies against TCR-ß and δ and found positive TCR-δ and negative TCR-ß. Therefore, we corrected the diagnosis to CGD-TCL, although the clinical course and the presence of dermatomyositis were reminiscent of SPTCL.

Extracutaneous neutrophilic infiltration of the spleen and lung associated with pyoderma gangrenosum of the skin.

We describe a patient with extracutaneous pyoderma gangrenosum (PG), who presented with chest pain. Histological examination showed extracutaneous neutrophilic infiltration of the spleen and lung, with later findings of PG.

PRC2 Components Maintain DNA Hypermethylation of the Upstream Promoter and Regulate Robo4 Expression in Endothelial Cells.

Roundabout4 (Robo4) is an endothelial cell-specific protein that stabilizes the vasculature in pathological angiogenesis and inflammation. We previously determined a 3-kb Robo4 promoter and demonstrated the importance of the upstream region for nuclear factor-kappaB (NF-κB)-mediated promoter activation induced by tumor necrosis factor α (TNFα). This region contains unique genomic features, including promoter region-specific DNA hypermethylation and chromatin condensation; however, the function of the region remains poorly understood. In this study, we analyzed the DNA sequences of the region and identified a motif for polycomb repressive complex 2 (PRC2). Chromatin immunoprecipitation assay indicates the binding of the PRC2 component, SUZ12, to the motif. A mutation in the motif decreased DNA methylation in embryonic stem cells and increased Robo4 promoter activity in endothelial cells. An inhibitor for the PRC2 component, EZH2, induced the promoter activity and expression of Robo4 in endothelial cells treated with or without TNFα. Taken together, these results indicate that the PRC2 components maintain DNA hypermethylation and suppress Robo4 expression via the PRC2 binding motif in the upstream promoter.

ETV2-TET1/TET2 Complexes Induce Endothelial Cell-Specific Robo4 Expression via Promoter Demethylation.

Although transcription factors regulating endothelial cell (EC)-specific gene expression have been identified, it is not known how those factors induce EC-specificity. We previously reported that DNA hypomethylation of the proximal promoter elicits EC-specific expression of Roundabout4 (Robo4). However, the mechanisms establishing EC-specific hypomethylation of the Robo4 promoter remain unknown. In this study, we demonstrated that the hypermethylated Robo4 proximal promoter is demethylated as human iPS cells differentiate into endothelial cells. Reporter assays demonstrated that ETV2, an ETS family transcription factor, bound to ETS motifs in the proximal promoter and activated Robo4 expression. Immunoprecipitation demonstrated direct interaction between ETV2 and methylcytosine-converting enzymes TET1 and TET2. Adenoviral expression of ETV2-TET1/TET2 complexes demethylated the Robo4 promoter and induced Robo4 expression in non-ECs. In summary, we propose a novel regulatory model of EC-specific gene expression via promoter demethylation induced by ETV2-TET1/TET2 complexes during endothelial differentiation.

Tumor Necrosis Factor α Induces the Expression of the Endothelial Cell-Specific Receptor Roundabout4 through the Nuclear Factor-κB Pathway.

Roundabout4 (Robo4) is an endothelial cell-specific receptor that regulates vascular stability. Recently, Robo4 has been shown to regulate vascular permeability in inflammation. However, the mechanisms regulating the Robo4 gene in the context of inflammation are poorly understood. In this study, we found that intravenous injection of tumor necrosis factor (TNF) α increased Robo4 expression in mouse organs. In vitro analyses showed that TNFα increased Robo4 expression in human primary endothelial cells, but not in cells pretreated with a nuclear factor (NF)-κB inhibitor. Reporter assays using wild-type and mutant Robo4 promoters indicated that TNFα activated the Robo4 promoter and that both the -2753 and -2220 NF-κB motifs were essential for this activation. Electrophoretic mobility shift assays demonstrated that the NF-κB p65-p50 heterodimer bound to these motifs. These findings were further supported by chromatin immunoprecipitation assays in endothelial cells. Taken together, these results indicated that TNFα induced Robo4 expression by facilitating NF-κB p65-p50 heterodimer binding to the -2753 and -2220 motifs in the Robo4 promoter in endothelial cells in the context of inflammation.

Bacteriological study of epidermal cysts.

The aim of this study was to determine whether bacterial infection plays a significant role in the inflammatory process of epidermal cysts. Samples from 152 patients (115 cases of inflamed and 37 of uninflamed epidermal cysts) were subjected to aerobic and anaerobic bacterial culture and the isolates were investigated. The rate of bacterial growth and the recovered anaerobes were significantly greater in the inflamed than the uninflamed epidermal cysts. However, it is difficult to determine whether recovered isolates from epidermal cysts represent "infection" or "colonization". In conclusion, this study revealed the predominance of anaerobes in inflamed cysts, strongly suggesting that anaerobes play a role in the inflammatory process.

Topical antibiotic treatment of impetigo with tetracycline.

Forty-nine children aged 0.2-13 years with bullous and eroded lesions, from which Staphylococcus aureus was isolated, were diagnosed with impetigo and entered into a randomized, open-labeled trial of topical oxytetracycline hydrochloride (tetracycline) compared with a combination of topical tetracycline and oral antibiotics. After one week of topical tetracycline treatment, 22 of the 28 patients were clinically cured, and the remaining six patients had improved. In the other treatment group, 14 patients of 21 were clinically cured and 7 patients improved by the combination of topical tetracycline and oral antibiotics. There were no significant differences between the two groups. Therefore, the present study suggests that topical tetracycline treatment is effective for the treatment of impetigo.