Boron Clusters Alter the Membrane Permeability of Dicationic Fluorescent DNA-Staining Dyes.

Membrane-permeable fluorescent dyes that stain DNA are useful reagents for microscopic imaging, as they can be introduced into living cells to label DNA. However, the number of these dyes, such as Hoechst 33342, is limited. Here, we show that the icosahedral dodecaborate B12Br122-, a superchaotropic carrier that delivers different types of molecules into cells, functions as an excellent carrier for membrane-impermeable fluorescent dyes. Propidium iodide (PI) and 4',6-diamidino-2-phenylindole (DAPI), dicationic membrane-impermeable fluorescent dyes that stain DNA, can permeate cell membranes in the presence of boron clusters. Methyl green (MG), a dicationic dye used in the histological and fluorescent staining of DNA, permeated cell membranes in the presence of boron clusters. In contrast, monocationic membrane-permeable fluorescent dyes, such as acridine orange and pyronin Y, exhibited reduced fluorescence in cells in the presence of boron clusters. Boron clusters do not quench dicationic fluorescent dyes in water in vitro but have quenching effects on monocationic fluorescent dyes. We have demonstrated that the addition of B12Br122- to impermeable dicationic fluorescent DNA-staining dyes, such as DAPI, PI, and MG, which have been widely used for numerous years, imparts membrane permeability to introduce these dyes into living cells.

Intracellular dynamics of actin affects Borna disease virus replication in the nucleus.

Borna disease virus (BoDV) is a nonsegmented, negative-strand RNA virus that uniquely replicates and establishes persistent infection in cell nucleus. Recent studies have demonstrated the presence of actin in the nucleus and its role in intranuclear phenomena such as transcription and DNA repair. Although nuclear actin is involved in the life cycle of some intranuclear DNA viruses, the interaction between BoDV and nuclear actin has not been reported. In this study, we show that the inhibition of the nucleocytoplasmic transport of actin affects the replication of BoDV in the nucleus. The knockdown of a nuclear export factor of actin, exportin 6, results in the induction of structural aberration in intranuclear viral factories of BoDV. Furthermore, the inhibition of the nuclear export of actin promotes accumulation of viral matrix protein in the cytoplasm and periphery of the infected cells. These results suggest that the dynamics of actin affect the replication of BoDV by disturbing the structure of viral factories in the nucleus.

Atypical lipomatous tumor in the ligamentum teres of liver: A case report and review of the literature.

A 61-year-old male was referred to our hospital with a three-month history of persistent epigastralgia and right hypochondralgia. Initial examination revealed a fist-size mass at the epigastric fossa. Ultrasonography showed a hemangioma and a mosaic echoic lesion in the ventromedian with poor blood-flow signal and linear hyperechoic part inside, and a clear border to the surroundings. Dynamic computed tomography revealed a highly enhanced effect from the portal-venous phase continuing to the equilibrium phase. T1-weighted gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid-enhanced image revealed a high intensity effect at the early phase that continued to the next phase. On the other hand, it contained a low intensity area by a fat suppression of that image. In addition, a T2-weighted image did not show a high intensity effect. Laparotomy was performed on the second day of hospitalization. The tumor had arisen from the ligamentum teres of the liver, and no metastasis or invasion of other organs was noted. It consisted of a lipid component of mature adipocytes and a fibrous component of deep dyeing pleomorphic or multinuclear atypical stromal cells. Immunohistochemical study of the atypical stromal cells demonstrated that they were positive for MDM2 and CDK4. A pathological diagnosis of atypical lipomatous tumor (ALT) was made, and the patient was discharged on the eighth day following the procedure. At the 6-mo follow-up dynamic CT, the patient was free of recurrence or metastasis. We experienced a patient with ALT in the ligamentum teres of the liver. This case suggests the need for a careful and detailed examination when encountering patients presenting with a mass; when neoplastic lesion is confirmed by image inspection, we should thoroughly investigate, including further image investigations and pathologic examination. The latter is the most important.

Findings of the margin around lesions by magnifying endoscopy with narrow-band imaging in early gastric carcinoma and intestinal metaplasia.

OBJECTIVE: Many endoscopists have reported their own classifications of early gastric carcinoma (EGC) using magnifying narrow-band imaging (M-NBI). However, few reports on classifying the margin around lesions by M-NBI have been published. The aim of this study was to advocate the usefulness of the demarcation area classification for the diagnosis of EGC. METHODS: Altogether 197 lesions that could be investigated by M-NBI were included in this study, consisting of 115 EGC and 82 intestinal metaplasias (IM). We hypothesized that the changes in white zone (fusion and erasure signs) and blood vessel (extend and draw sign) were the indications of EGC and we retrospectively investigated this hypothesis. RESULTS: For the investigation of the white zone in the demarcation area, both fusion (P < 0.0001) and erasure signs (P < 0.0001) were observed more often in EGC than in IM, with an accuracy of 80.7%. For the investigation of blood vessel in the demarcation area, both the extend (P < 0.001) and the draw sign (P < 0.0001) were observed more often in EGC than in IM, with an accuracy of 59.9%. CONCLUSION: Estimations of the white zone and blood vessels in the demarcation area are useful for the diagnosis of EGC.

Primary Duodenal Adenocarcinoma without Stenosis: A Case Report with a Brief Literature Review.

This article focuses on the symptomatic and diagnostic problems of primary duodenal adenocarcinoma (PDA) by way of two case reports and a literature review. An 85-year-old woman with an adenocarcinoma in the 1st duodenal portion was offered palliative care. A 90-year-old woman with an adenocarcinoma in the 3rd duodenal portion was also offered palliative care. A unique finding in the two cases reported herein is that PDA did not cause stenosis and occlusion of the lumen. As no reports of PDA without stenosis have been published so far, these cases may add to our knowledge of PDA. The diagnosis of PDA is often delayed because its symptoms may be absent until the tumor has progressed, thus leading to a delay of several months. Patients typically present with a long history of variable and vague symptoms, and many are diagnosed with advanced disease. As regards clinical manifestations, abdominal pain is the most frequent symptom. The majority of these tumors are found to have infiltrated the duodenal wall at presentation, with many being unresectable due to local and distal invasion. Esophagogastroduodenoscopy and gastrointestinal barium radiography are the main diagnostic tests for PDA, detecting 88.6 and 83.3% of tumors, respectively. In some cases, ultrasonography or computed tomography are useful for detecting PDA and determining vascular invasion.

Evolutionary dynamics of spliceosomal intron revealed by in silico analyses of the P-Type ATPase superfamily genes.

It has been long debated whether spliceosomal introns originated in the common ancestor of eukaryotes and prokaryotes. In this study, we tested the possibility that extant introns were inherited from the common ancestor of eukaryotes and prokaryotes using in silico simulation. We first identified 21 intron positions that are shared among different families of the P-Type ATPase superfamily, some of which are known to have diverged before the separation of prokaryotes and eukaryotes. Theoretical estimates of the expected number of intron positions shared by different genes suggest that the introns at those 21 positions were inserted independently. There seems to be no intron that arose from before the diversification of the P-Type ATPase superfamily. Namely, the present introns were inserted after the separation of eukaryotes and prokaryotes.

The sigH gene sequence can subspeciate staphylococci.

In an evolutionarily conserved gene organization (syntenic region), the sigH gene shares exceptionally low homology among staphylococcal species. We analyzed the "positionally cloned" sigH sequences of 39 staphylococcal species. The topology of the SigH phylogenetic tree was consistent with that of 16S rRNA. Certain clinical isolates were successfully differentiated at the species level with the sigH sequence data set. We propose that the sigH gene is a promising molecular target in genotypic identification because it is highly discriminative in differentiating closely related staphylococcal species.

A new staphylococcal sigma factor in the conserved gene cassette: functional significance and implication for the evolutionary processes.

BACKGROUND: Staphylococcus aureus is a major human pathogen and causes a serious hospital infection due to the acquired multidrug resistance. Unlike the well-studied bacteria such as Escherichia coli and Bacillus subtilis, which have seven and 18 sigma factors, respectively, only two sigma factors have been known for S. aureus. We searched for possible sigma factor genes by examining the S. aureus genome with a special attention to the gene arrangement around the sigma factor genes of a close relative, B. subtilis. RESULTS: A new sigma factor gene was identified in Staphylococcus. The gene constituted a conserved gene cluster with other genes including translation- and transcription-related genes. Phylogenetic analysis and comparison of the gene sequences among species indicated that the staphylococcal sigma factor originated from a common ancestor of B. subtilis SigH. An over-expression of this sigma factor in S. aureus resulted in a drastic induction of the expression of the com operons that encode proteins required for the natural genetic competence. CONCLUSIONS: We demonstrated that the newly identified staphylococcal sigma factor participated in a regulatory network of transcription that controlled the genetic competence genes. In our phylogenetic tree, the factor was classified as a single group with a common function.

P-type ATPase superfamily: evidence for critical roles for kingdom evolution.

The P-type ATPase has become a protein superfamily. On the basis of sequence similarities, the phylogenetic analyses, and substrate specificities, this superfamily can be classified into 5 families and 11 subfamilies. A comparative phylogenetic analysis demonstrates the relationship between the molecular evolution of these subfamilies and the establishment of the kingdoms of living things.