Identification of a negative regulatory DNA element for neuronal BC1 RNA expression by RNA polymerase III.

BC1 RNA is a neuronal cell-specific RNA polymerase III (Pol III) transcript. The BC1 RNA gene has plural types of Pol III promoters, in addition to which an E-box sequence (E2 site) acts as a transcriptional activator, which is recognized by a brain-specific protein(s). Using an in vitro transcription system, we found that the upstream region of the BC1 RNA gene contained a sequence that interfered with the activity of the E-box element in a distance-independent manner. A tandem repeat within this sequence, which was weakly homologous with the neuron-restrictive silencer element (NRSE) found in the Pol II system, was recognized by a brain nuclear protein. Consistently, the transcriptional activity increased by deleting the tandem repeat sequence. We called this BC1 RNA-repressing element BCRE. The DNA-binding specificities of BCRE-binding protein differed from that of NRSE-binding protein (NRSF). A similar protein with an ability to bind to BCRE was also found in liver and kidney. Furthermore, the glutamate analog kainic acid increased the DNA-binding of both E2 site-binding protein and BCRE-binding protein, and then the levels of BC1 RNA also increased transiently. Our results suggested that both positive and negative regulatory elements contribute to neuronal BC1 RNA expression.

The F(ab')2 fragment of an anti-ICAM-1 monoclonal antibody attenuates liver injury after orthotopic liver transplantation.

Long-term storage of liver grafts results in increased adhesion of leukocytes onto the sinusoidal walls. This eventually leads to posttransplant graft damage through disturbances of hepatic microcirculation. Intracellular adhesion molecule-1 (ICAM-1) is known to be involved in attachment of leukocytes. This study was designed to examine whether ICAM-1 participated in the pathogenesis of posttransplant liver injury. Inbred Lewis rats were used as both donors and recipients to avoid immunoreactivity. Donor livers were stored for either 1 or 6 hr in ice-cold Euro-Collins solution and subsequently implanted. Expression of ICAM-1 was examined immunohistochemically. In some rats that received livers stored for 6 hr, the intact IgG (1.0 mg/kg) or the F(ab')2 fragment (0.5 mg/kg) of an anti-ICAM-1 mAb (1A29) was administered via the tail vein immediately after reperfusion of portal blood. In the group receiving livers stored for 6 hr, ICAM-1 began to be expressed on the sinusoidal endothelial cells as early as 15 min after reperfusion of the portal blood. Strong ICAM-1 expression was observed from 2 hr up to 24 hr after reperfusion. In contrast, expression of ICAM-1 was not evident at any time point after surgery in the 1-hr storage group as well as in untransplanted, normal livers. Serum alanine aminotransferase (ALT) levels were significantly higher in the 6-hr storage group compared with those of the 1-hr storage group (1-hr: 171 +/- 9 IU/L; 6-hr: 825 +/- 109 IU/L, P < 0.05; mean +/- SEM) 24 hr after transplantation. Serum ALT levels were markedly reduced by treatment with the F(ab')2 fragment of 1A29 (247 +/- 34 IU/L, P < 0.05 vs. 6-hr storage group). This was associated with reduced accumulation of leukocytes in the liver. In marked contrast, treatment with the intact IgG of 1A29 increased serum ALT levels dramatically (5297 +/- 634 IU/L, P < 0.05 vs. 6-hr storage group) and reduced serum complement. Histological examination revealed focal hepatocellular necrosis 24 hr after surgery in the 6-hr storage group. Treatment with the F(ab')2 fragment decreased the liver damage; in marked contrast, treatment with the intact IgG strikingly aggravated the injury, as characterized by massive necrosis throughout the liver. Liver damage caused by the intact IgG might be related to activation of the complement system by the Fc portion of the antibody. Taken together, these results indicate that ICAM-1 is involved in the mechanism of postoperative liver injury following liver transplantation.

Endoscopic appearances of hemorrhagic peptic ulcers and efficacy of H2-receptor antagonists.

BACKGROUND/AIMS: In this retrospective study, we compared the effects of histamine H2-receptor antagonists to those of antacids and anticholinergics in patients with hemorrhagic ulcers with various endoscopic appearances of bleeding. PATIENTS AND METHODS: Patients with hemorrhagic ulcers (n = 376) were examined by emergency endoscopy and were treated with 1) antacids and anticholinergic drugs or 2) H2-receptor antagonists. RESULTS: In ulcer patients with oozing or fresh red coagulation, H2-receptor antagonists ceased further hemorrhage more effectively (65.9% of the cases) than antacids and anticholinergic drugs (46.7%). In patients with projectile bleeding, both of the treatments failed to stop hemorrhage. There were no significant differences in favorable outcome in the patients only with old black coagulation between antacid and anticholinergic drugs-treated group and H2-receptor antagonists-treated group (94.4% and 93.8%, respectively). CONCLUSIONS: The results suggest that H2-receptor antagonists are more effective than antacids and anticholinergic drugs in patents with peptic ulcer with fresh coagulation or oozing, but not with projectile bleeding or old black coagulation. The results also indicate that endoscopic appearances of peptic ulcer bleeding are good predictors for the effects of medication.

BC1 RNA protein particles in mouse brain contain two y-,h-element-binding proteins, translin and a 37 kDa protein.

Neural BC1 RNA is distributed in dendrites in the form of ribonucleoprotein particles (RNP). Recently, Han et al. reported that testis-brain RNA-binding protein (the mouse homologue of Translin), known to be a translational repressor, links a subset of mRNAs to microtubules (MTs) through binding to their y-,h-sequence elements. We found that similar elements are also present in BC1 RNA. Therefore, it is possible that they also act as cis-elements, together with their transacting proteins, and control the transport of BC1 RNA along dendritic MTs. In this study, we demonstrated that two y-,h-element-binding proteins copurified with BC1 RNP. One was identified as mouse Translin and the other was a 37 kDa protein. This macromolecular assembly may constitute a transport particle for BC1 RNA. It is also possible that BC1 RNP or Translin itself may play a regulatory role(s) in the translation of mRNAs within dendrites.

Endoscope disinfection using acidic electrolytic water.

BACKGROUND AND STUDY AIMS: The aim of the present study was to evaluate a new endoscope disinfector (WM-1) that uses acidic electrolytic water (AEW). MATERIALS AND METHODS: AEW was produced by electrolysis of a 0.05% NaCl-water mixture, with a redox potential greater than 1000 mV and a pH lower than 2.7. In the first study, an endoscope artificially contaminated with 15 species of bacteria and four strains of viruses was treated using the WM-1. In the second study, endoscopic contamination after clinical use was examined by culture for Helicobacter pylori and other bacteria, and by polymerase chain reaction for the H. pylori urease gene and hepatitis C virus. The extent of contamination was then examined after exposing the WM-1 to AEW. The safety of AEW was examined using both in vivo and in vitro studies. RESULTS: All of the bacteria and viruses were destroyed or inactivated after the instrument had been exposed to AEW. Clinical contamination was detected from the instrument in 19 of 30 endoscopic procedures, whereas no bacteria or viruses were detected after five minutes' exposure to AEW. AEW was found to be nonirritant, nontoxic to cells, and nonmutagenic. CONCLUSION: The WM-1 successfully and safely disinfected the endoscopes. With running costs of yen 24 per day ($0.21 per day), the WM-1 provides an effective and inexpensive alternative to conventional disinfection equipment.