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Pseudo-first-order rate constants (kobsd) have been measured spectrophotometrically for the nucleophilic substitution reaction of Y-substituted-phenyl picolinates (7a-f) with potassium ethoxide (EtOK) in anhydrous ethanol at 25.0 ± 0.1°C. The plot of kobsd vs. [EtOK] curves upward while the plot of kobsd/[EtO-]eq vs. [EtO-]eq is linear with a positive intercept in all cases. Dissection of kobsd into kEtO- and kEtOK (i.e., the second-order rate constants for the reactions with the dissociated EtO- ion and ion-paired EtOK, respectively) has revealed that the ion-paired EtOK is more reactive than the dissociated EtO-. The σo constants result in a much better Hammett correlation than σ- constants, indicating that the reaction proceeds through a stepwise mechanism in which departure of the leaving group occurs after the rate-determining step (RDS). K+ ion catalyzes the reaction by increasing the electrophilicity of the reaction center through formation of a cyclic transition state (TS). The catalytic effect decreases as the substituent Y becomes a stronger electron-withdrawing group (EWG). Development of a positive charge on the N atom of the picolinyl moiety through resonance interactions is responsible for the decreasing K+ ion catalysis. [ABSTRACT FROM AUTHOR]

CXXC5 is a member of a small subset of proteins containing CXXC-type zinc-finger domain. Here, we show that CXXC5 is a transcription factor activating Flk-1, a receptor for vascular endothelial growth factor. CXXC5 and Flk-1 were accmulated in nucli and membrane of mouse embryonic stem cells (mESCs), respectively, during their endothelial differentiation. CXXC5 overexpression induced Flk-1 transcription in both endothelium-differentiated mESCs and human umbilical vein endothelial cells (HUVECs). In vitro DNA binding assay showed direct interaction of CXXC5 on the Flk-1 promoter region, and mutation on its DNA-binding motif abolished transcriptional activity. We showed that bone morphorgeneic protein 4 (BMP4) induced CXXC5 transcription in the cells, and inhibitors of BMP signaling suppressed the CXXC5 induction and the consequent Flk-I induction by BMP4 treatment. CXXC5 knockdown resulted in suppression of BMP4-induced stress fiber formation (56.8±1.3% decrease, P<0.05) and migration (54.6±1.9% decrease, P<0.05) in HUVECs. The in vivo roles of CXXC5 in BMP-signaling-specific vascular development and an-giogenesis were shown by specific defect of caudal vein plex vessel formation (57.9±11.8% decrease, P<0.05) in cxxc5 morpholino-injected zebrafish embryos and by supression of BMP4-induced angigogensis in subcuta-neously injected Matrigel plugs in CXXC5-/- mice. Overall, CXXC5 is a transcriptional activator for Flk-1, mediating BMP signalimediating BMP signaling for differentiation and migration of endothelial cell and vessel formation. [ABSTRACT FROM AUTHOR]

Lymphoid tissue inducer (LTi) cells have a well established role in secondary lymphoid tissue development. Here, we report on the heterogeneity of LTi cells based on their CD4 and chemokine receptor expression. The CD4− LTi-cell population has a similar phenotype to the CD4+ population, with similar chemokine-receptor-expressing subsets. In both embryonic and adult spleen the CD4− LTi-cell population is comparable as a proportion of total splenocytes to its CD4+ counterpart. In contrast, different proportions of CD4+ and CD4− LTi cells are found in different lymph nodes. Both CD4+ and CD4− LTi cells share the anatomical location and are associated with vascular cell adhesion molecule-1-positive stromal cells in spleen and lymph nodes. The numbers of both CD4+ and CD4− LTi cells in adult spleen are augmented in the presence of B cells. With the exception of CD4, there is a strong correlation coefficient (0·89) for gene expression between the two populations. Polymerase chain reaction analysis of individual CD4+ and CD4− LTi cells shows that a similar proportion in embryonic and adult spleen co-expressed both CXCR5 and CCR7 or CXCR5 alone: 84·6% for adult CD4+ and 87·6% for adult CD4−; 95·3% for embryonic CD4+ and 91·5% for embryonic CD4−. Consistently fewer CCR7 single-positive cells were found in the CD4+ and CD4− fractions in the embryo. [ABSTRACT FROM AUTHOR]

Subcutaneous panniculitis-like T-cell lymphoma is a rare cytotoxic T-cell lymphoma of the skin that preferentially infiltrates the subcutaneous tissue. We report here this lymphoma occurring in a 26-month-old Korean girl. She presented with multiple erythematous subcutaneous nodules on both extremities and her back along with systemic symptoms. She had a protracted course of multiple erythematous subcutaneous nodules for 1 month and a spiking fever was often noted. The histopathologic findings for the subcutaneous nodules were lobular panniculitis-like material that was composed of atypical lymphocytes and histiocytes. The atypical lymphocytes characteristically rimmed individual fat cells in a lace-like pattern and some of the histiocytes showed phagocytosed white blood cells occasionally. Immunophenotypic studies showed CD3+, CD45RO+, CD20−, CD4−, CD8+, and CD56−. She is currently being treated with combination chemotherapy of cyclophosphamide, doxorubicin, vincristine, and prednisolone. [ABSTRACT FROM AUTHOR]

The article presents a letter to the editor about prurigo pigmentosa.

A letter to the editor about lobular capillary hemangioma is presented.

A letter to the editor is presented article concerning atypical varicella exanthem associated with the use of infliximab.

The article focuses on the case of a male that had developed asymptomatic, well-defined depigmentation on his cheek and neck without the occurrence of itching and other symptoms. Moreover, he was diagnosed with chemical depigmentation that resulted from nasal cannula. It also mentions that PVC should be added to the list of chemicals that can induce depigmentation.

Presents a case report on the development of skin lesions in a woman after disinfection with pigosept, an antiseptic swab for blood taking. Disease history of the woman; Composition of the swab used on the woman for blood taking; Constituents of tego, an antiseptic detergent that causes contact dermatitis.