Transgenesis by means of blastocyst-derived embryonic stem cell lines.

This study demonstrates that blastocyst-derived embryonic stem cells (ES cells) can be used as a vehicle for transgenesis. The method is nearly as efficient as other methods, and the introduced neomycin phosphotransferase (neo) gene is stably transmitted through several generations with no apparent loss in G418 resistance. An important factor contributing to the efficiency of this process is the rigorous selection, before blastocyst injection, of genetically transformed cells for in vitro developmental pluripotency. One of the advantages of the ES cell route to transgenesis is that it provides investigators with the opportunity to screen for the desired genetic alterations before reintroducing the ES cells into the animal.     

Treatment of a clinically relevant plant-pathogenic fungus with an agricultural azole causes cross-resistance to medical azoles and potentiates caspofungin efficacy

Azoles are extensively applied in agriculture and medicine, and a relationship between the development of azole resistance in agriculture and the development of azole resistance in clinical practice may exist. The maize pathogen Colletotrichum graminicola, causing cutaneous mycosis and keratitis, has been used to investigate the acquisition of resistance to an agricultural azole and the resulting cross-resistance to various medical antifungal agents. Azole-adapted strains were less sensitive to all azoles tested but showed increased sensitivity to caspofungin, amphotericin B, and nystatin. Viability staining and infection assays with excised human skin confirmed these data.     

NFATc2 and NFATc3 transcription factors play a crucial role in suppression of CD4+ T lymphocytes by CD4+ CD25+ regulatory T cells

The phenotype of NFATc2(-/-) c3(-/-) (double knockout [DKO]) mice implies a disturbed regulation of T cell responses, evidenced by massive lymphadenopathy, splenomegaly, and autoaggressive phenomena. The population of CD4(+) CD25(+) T cells from DKO mice lacks regulatory capacity, except a small subpopulation that highly expresses glucocorticoid-induced tumor necrosis factor receptor family-related gene (GITR) and CD25. However, neither wild-type nor DKO CD4(+) CD25(+) regulatory T cells (T reg cells) are able to suppress proliferation of DKO CD4(+) CD25(-) T helper cells. Therefore, combined NFATc2/c3 deficiency is compatible with the development of CD4(+) CD25(+) T reg cells but renders conventional CD4(+) T cells unresponsive to suppression, underlining the importance of NFAT proteins for sustaining T cell homeostasis.     

Search for Kaposi's sarcoma-associated virus DNA in hemangioproliferative disorders and cutaneous malignant lymphoma

Recently, a Kaposi's sarcoma-associated herpesvirus (KSHV) was discovered. We evaluated by PCR 14 paraffin-embedded specimens with the histological diagnosis of endemic, classic and HFV-associated Kaposi's sarcoma (KS) for the presence of the KSHV DNA sequence. In addition, biopsies of adjacent, histologically unaffected skin, peripheral-blood mononuclear cells (PBMCs) of HIV-infected KS patients, PBMCs of one classic KS patient, and specimens of patients with hemangioproliferative disorders other than KS as well as samples of cutaneous T-and B-cell lymphoma were analyzed for KSHV. In all cases of KS, independent of the KS subtype, KSHV was detected in lesional skin. No KSHV was found in biopsies of the adjacent unaffected skin or PBMCs of HFV-infected KS patients. We found KSHV in the PBMCs of a patient with classical KS. All specimens of cutaneous T-and B-cell lymphomas or lymphomatoid papulosis were negative for KSHV. In addition, the samples with hemangioproliferative disorders other than KS were negative for KSHV. There was one borderline case of KS or acroangiodermatitis that was positive for KSHV. Additional histological sections and clinical evaluation confirmed the diagnosis of classic KS. In summary, the data indicate that PCR for KSHV should be a useful diagnostic tool in cases of hemangioproliferative disorders.