Prevention of Tracheo-Innominate Artery Fistula Formation as a Complication of Tracheostomy: Two Case Reports.

Tracheo-innominate artery fistula (TIF) is a rare complication of tracheostomy and refers to the formation of a fistula between the trachea and innominate artery. Because TIF is fatal, prevention rather than treatment is very important. Here we report the cases of two high-risk patients who underwent tracheostomy, and in whose cases attempts were made to lower the risk of TIF. In the first patient who developed a chest deformity with Duchenne muscular dystrophy, a tracheostomy was performed with a high-level (cricothyroid level) approach compared with the standard tracheostomy. In the second patient, the thoracic cage was relatively small due to a giant omphalocele, and the risk of a fistula forming was decreased by wrapping the innominate artery with an opened polytetrafluoroethylene vascular graft after resolving crowding of the intrathoracic cavity by total thymectomy. There was no TIF occurrence at the outpatient follow-up in either case. We expect that our approaches may be effective intervention measures for preventing TIF.

Rapid detection of virulence stx2 gene of Enterohemorrhagic Escherichia coli using two-step ultra-rapid real-time PCR.

A rapid detection method for Enterohemorrhagic Escherichia coli (EHEC), which has the virulent stx2 gene, was developed using a two-step, ultra-rapid real-time (URRT) PCR. URRT PCR was designed to detect the stx2 gene using a microchip-based, real-time PCR system, GenSpector TMC-1000, which only has a 6 microl total reaction volume with an extremely short denaturation step and combined annealing/extension step (1 and 3 s, respectively) for each cycle. Specific primers for the stx2 gene were designed to amplify a 100 bp region known for genetic stability among the various EHEC strains. Using the URRT PCR method, stx2 gene could be detected in 7 min 8 s including melting point (Tm) analysis. The detection limit for the stx2 gene for URRT-PCR was estimated to be 3 c.f.u./PCR with the amplification product having a consistent Tm of 85.2 +/- 0.4 degrees C. This method was tested for the various applications relevant to the different EHEC strains and was useful for the rapid detection of stx2-carrying EHEC strains.

Apoptosis Induction by Menadione in Human Promyelocytic Leukemia HL-60 Cells.

Cell death induced by menadione (vitamin K-3,2-methyl-1,4-naphthoquinone) has been investigated in human promyelocytic leukemia HL-60 cells. Menadione was found to induce both apoptosis and necrosis in HL-60 cells. Low concentration (1~50 µM) of menadione induced apoptotic cell death, which was demonstrated by typical DNA ladder patterns on agarose gel electrophoresis and flow cytometry analysis. In contrast, a high concentration of menadione (100 µM) induced necrotic cell death, which was demonstrated by DNA smear pattern in agarose gel electrophoresis. Necrotic cell death was accompanied with a great reduction of cell viability. Menadione activated caspase-3, as evidenced by both increased protease activity and proteolytic cleavage of 116 kDa poly(ADP-ribose) polymerase (PARP) into 85 kDa cleavage product. Caspase-3 activity was maximum at 50 µM of menadione, and very low at 100 µM of menadione. Taken together, our results showed that menadi-one induced mixed types of cell death, apoptosis at low concentrations and necrosis at high concentrations in HL-60 cells.

Activity of protein kinase C modulates the apoptosis induced by polychlorinated biphenyls in human leukemic HL-60 cells.

Polychlorinated biphenyls (PCBs) induce apoptotic cell death of HL-60 cells. In the present study, we examined the possible involvement of protein kinase C (PKC) in PCB-induced apoptosis of HL-60 cells. Treatment of cells with phorbol 12-myristate 13-acetate (PMA), an activator of PKC, suppressed DNA fragmentation induced by PCBs in HL-60 cells. Treatment with another active phorbol ester, phorbol-12,13-dibutyrate (PDBu), also suppressed PCB-induced DNA fragmentation, whereas 4alpha-phorbol-12,13-didecanoate (4alphaPDD), an inactive phorbol ester, did not affect PCB-induced apoptosis of HL-60 cell. Moreover, 1-oleoyl-2-acetyl-sn-glycerol (OAG), an activator of PKC that is not a phorbol ester, also suppressed PCB-induced DNA fragmentation. However, 1-(5-isoquinolinylsulfonyl)-2-methylpiperazine (H-7), an inhibitor of PKC, increased DNA fragmentation induced by PCBs. These results demonstrate that the activation of PKC is responsible for the suppression of PCB-induced apoptosis of HL-60 cells. Furthermore, inhibition of PKC promotes DNA fragmentation of HL-60 cells treated with PCBs, thereby suggesting the involvement of PKC activity in PCB-induced apoptosis of HL-60 cells.