OBJECTIVES:The usefulness of non-magnifying endoscopy with narrow-band imaging (NBI; NM-NBI) in the screening of early esophageal squamous cell carcinoma (SCC) and high-grade intraepithelial neoplasia (HGIN) remains unclear. Here, we aimed to compare NM-NBI and chromoendoscopy with iodine staining (CE-Iodine) in terms of the diagnostic performance, and to evaluate the usefulness of NM-NBI in detecting early esophageal SCC.METHODS:We prospectively enrolled 202 consecutive patients (male/female=180/22; median age, 67 years) with high-risk factors for esophageal SCC. All patients received endoscopic examination with NM-NBI and CE-Iodine to screen for early esophageal SCC or HGIN. We conducted the examinations sequentially, and calculated the accuracy, sensitivity, and specificity through a per-lesion-based analysis. A propensity score matching analysis was performed to reduce the effects of selection bias, and we compared the respective outcomes according to NM-NBI and CE-Iodine after matching.RESULTS:The accuracy, sensitivity, and specificity of NM-NBI were 77.0, 88.3, and 75.2%, respectively, and those for unstained areas by CE-Iodine were 68.0, 94.2, and 64.0, respectively. The accuracy and specificity of NM-NBI were superior to those of CE-Iodine (P=0.03 and P=0.01, respectively). However, the sensitivity did not significantly differ between NM-NBI and CE-Iodine (P=0.67). The accuracy and specificity of NM-NBI before matching were superior to those of CE-Iodine after matching (P=0.04 and P=0.03).CONCLUSIONS:NM-NBI was useful and reliable for the diagnosis of esophageal SCC and can be a promising screening strategy for early esophageal SCC.
A gene encoding DNA ligase (lig Tk ) from a hyperthermophilic archaeon, Thermococcus kodakaraensis KOD1, has been cloned and sequenced, and its protein product has been characterized. ؉ . This is the first biochemical study of a DNA ligase from a hyperthermophilic archaeon.DNA ligases (EC 6.5.1.1 and EC 6.5.1.2) catalyze the phosphodiester bond formation between adjacent 3Ј-hydroxyl and 5Ј-phosphoryl groups at a single-strand break in doublestranded DNA (22). They are essential enzymes for maintaining the integrity of the genome during DNA replication (24), DNA excision repair (48), and DNA recombination (16). DNA strand breaks are commonly generated as reaction intermediates in these events, and the sealing of these breaks solely depends on the proper function of DNA ligase. Therefore, DNA ligases are indispensable enzymes in all organisms.DNA ligases fall into two groups on the basis of the required cofactor for activity: the group requiring ATP (8) and the group requiring NAD ϩ (43). There is high similarity among the ligases within the ATP-dependent group (19) or NAD ϩ -dependent group (42). ATP-dependent DNA ligase I from humans and Saccharomyces cerevisiae are 42% identical, and NAD ϩ -dependent enzymes from Escherichia coli and Thermus thermophilus are 46% identical. However, enzymes between the two groups show no similarity, with the exception of the KXDG motif, which includes the active-site lysine (19). Furthermore, biochemical investigations have indicated that there is strict specificity towards the respective cofactors. This suggests that the two groups have evolved through completely different pathways.It is now accepted that both ATP-dependent and NAD ϩ -dependent DNA ligases catalyze their reactions through a common mechanism (7). The ligation reaction proceeds through three steps: (i) activation of the enzyme through the covalent addition of AMP to the conserved active-site lysine of the protein, accompanied by the release of PP i or nicotinamide mononucleotide from the cofactor (ATP or NAD ϩ ), (ii) transfer of AMP from the protein to the 5Ј-phosphoryl group of the nick on the DNA, and (iii) phosphodiester bond formation with concomitant release of free AMP from the adenylated DNA intermediate.Biochemical and genetic studies have been performed for DNA ligases from various organisms. It has been shown that eukaryotes (17, 33, 46), viruses (29, 30), and bacteriophages (7,20) harbor ATP-dependent enzymes. Although only a single type of DNA ligase has been reported for viruses and bacteriophages, eukaryotic organisms have multiple enzymes. Five distinct DNA ligases have been reported from mammalian cells (17,33,45,46). ATP-dependent enzymes show a wide range in molecular mass, from 41 kDa (bacteriophage T7) (7) to 102 kDa (human DNA ligase I) (2). This considerable difference in size is mainly due to the diversity of the N-terminal region of each DNA ligase. DNA ligase I from humans includes a regulatory domain of 216 amino acid residues in its N-terminal region, which is dispensable for DNA ligas...
The Lixelle column is an adsorbent column used to eliminate beta2-microglobulin (beta2M) selectively from circulating blood of dialysis related amyloidosis (DRA) patients, which is used in combination with a dialyzer in series. The column has such a high capacity for adsorbing beta2M that the most intensive removal of beta2M has been possible. In clinical trials of the column, the obvious improvement of subjective symptoms such as decreases in the frequency of nocturnal awakening, the joint pain severity index, and the joint mobility index were observed. Hypotension has been the most frequent adverse event observed during treatment since the column was put on the market. It is very important to clarify the causes of both the efficacy and the side effects. A controlled prospective study is now in progress to clarify the efficacy more scientifically. The results will be published soon elsewhere.
Dialysis-related amyloidosis (DRA) is characterized by the presence of beta 2-microglobulin (beta 2-m) in the plasma. In order to eliminate beta 2-m from the circulating blood, the beta 2-m selective adsorbent for direct hemoperfusion (DHP) was developed. A DHP column (BM-01), containing 350 ml of the adsorbent, was subjected to clinical trials. The column was connected with a PAN (AN69) membrane dialyzer in series and used 3 times a week for 1 week (11 patients), 4 weeks (5 patients), 6 months (1 patient) and 12 months (2 patients). The percent reduction (%) of beta 2-m was for 16 patients (for 1 or 4 weeks), more than 65, and for 3 patients (for more than 6 months), 76.5 +/- 4.9, 73.5 +/- 5.7, 72.2 +/- 6.2. At the end of each session, beta 2-m plasma levels were found to be below 10 mg/L, with 3.4 mg/L being the lowest. The total amounts of beta 2-m removed were 172.5 +/- 22.3, 257.0 +/- 75.6, 157.6 +/- 32.2 and 429.8 mg/session at max. Two out of these three patients had a favorable effect on joint symptoms and ocular fundus. It can be concluded that this selective adsorption therapy may delay the progression of DRA, and is worth considering for wide application.
Objective Gastrointestinal stromal tumors (GISTs) are the most frequently occurring mesenchymal tumors of the GI tract. Double-balloon enteroscopy (DBE) and capsule endoscopy (CE) promise the detection and accurate diagnosis of small bowel diseases in patients with obscure GI bleeding (OGIB). The aim of the present study was to analyze the clinical characteristics of small bowel GISTs and the usefulness of DBE, CE and computed tomography (CT). Methods Among 705 cases with OGIB examined between December 2003 and January 2011, 12 (1.7%) cases of small bowel GIST were identified. We analyzed endoscopic appearance, tumor-size and location, detection rate by DBE, CE and CT and clinical course in each of these cases. Results Of the 12 patients with GIST, eight were men. The mean patient age was 53.6 years. The presenting symptoms in most patients included tarry stools and/or anemia. Six patients required blood transfusions. The detection rates of DBE, CE and CT were 92%, 60% and 67%, respectively. All cases, except for one incomplete study, were identified using DBE; however, one case was not diagnosed as a tumor because of the presence of extramural growth. A pathological diagnosis of GIST was obtained using biopsies during DBE in three (45%) of seven cases. Lower detection rates were found in cases with intramural and extramural growth, larger tumors (! 35 mm) detected by CE and intraluminal growth and smaller tumors (<35 mm) detected by CT. Conclusion DBE or a combination of CE and CT are thus considered to be useful for detecting small bowel GISTs.
We have previously identi®ed a DNA ligase (Lig Tk ) from a hyperthermophilic archaeon, Thermococcus kodakaraensis KOD1. The enzyme is the only characterized ATP-dependent DNA ligase from a hyperthermophile, and allows the analysis of enzymatic DNA ligation reactions at temperatures above the melting point of the substrates. Here . Using various 3¢ hydroxyl group donors (L-DNA) and 5¢ phosphate group donors (R-DNA), we could detect ligation products as short as 16 nucleotides, the products of 7 + 9 nucleotide or 8 + 8 nucleotide combinations at 40°C. An elevation in temperature led to a decrease in reaction eciency when short oligonucleotides were used, suggesting that the formation of a nicked, double-stranded DNA substrate preceded enzymesubstrate recognition. Lig Tk was not inhibited by the addition of excess duplex DNA, implying that the enzyme did not bind strongly to the double-stranded ligation product after nick-sealing. In terms of reaction ®delity, Lig Tk was found to ligate various substrates with mismatched basepairing at the 5¢ end of the nick, but did not show activity towards the 3¢ mismatched substrates. Lig Tk could not seal substrates with a 1-nucleotide or 2-nucleotide gap. Small amounts of ligation products were detected with DNA substrates containing a single nucleotide insertion, relatively more with the 5¢ insertions. The results revealed the importance of proper base-pairing at the 3¢ hydroxyl side of the nick for the ligation reaction by Lig Tk .Keywords: archaea; DNA ligase; hyperthermophile; Thermococcus.DNA ligases (EC 6.5.1.1 and EC 6.5.1.2) are universally found in bacteria, eukaryotes and archaea. In addition, they are also found in viruses and bacteriophages [1±5]. DNA ligases catalyse the phosphodiester bond formation between adjacent 3¢ hydroxyl and 5¢ phosphate groups at a singlestrand break in double-stranded DNA [5,6]. They are essential enzymes for maintaining the integrity of the genome during DNA replication [7], DNA excision repair [8] and DNA recombination [9]. DNA strand breaks are commonly generated as reaction intermediates in these events, and the sealing of these breaks depends solely on the proper function of DNA ligase [2]. Therefore DNA ligases are indispensable enzymes in all organisms.DNA ligases fall into two groups, ATP-dependent DNA ligases and NAD + -dependent DNA ligases, on the basis of the required cofactor for ligase±adenylate formation [2,5,6].ATP-dependent enzymes have been found in viruses, bacteriophages, eukaryotes, archaea and, recently, in bacteria, whereas NAD + -dependent enzymes have been found exclusively in bacteria [2,3,5]. There is high similarity among the ligases within the ATP-dependent groups [10] or NAD + -dependent groups [11,12]. However, enzymes between the two groups show no similarity, with the exception of the AMP-binding site [10]. It is now accepted that both ATP-dependent and NAD + -dependent DNA ligases catalyse their reactions through a common mechanism [13]. The ligation reaction proceeds through three steps. In the ®rst ...
We describe results from a feasibility study of a newly developed low‐density lipoprotein (LDL) adsorbent designed for use in whole‐blood infusion LDL‐hemoperfusion. The adsorbent has almost the same chemical structure as the Liposorber adsorbent (dextran sulfate cellulose beads) but has a larger particle size. In whole‐blood perfusion tests, the adsorbent adsorbed atherogenic LDL cholesterol directly from whole blood but left concentrations of high‐density lipoprotein cholesterol largely unchanged. In whole‐blood perfusion tests using fresh human donor blood or bovine blood anticoagulated with acid citrate dextrose solution or sodium citrate, the adsorbent showed minimal side effects in terms of blood cell activation, complement activation, and blood cell loss, suggesting that it has excellent blood compatibility. In addition, the adsorbent showed mechanical stability and absence of hemolysis. In conclusion, the new adsorbent showed the appropriate characteristics for an LDL adsorbent column for use in whole‐blood infusion LDL‐hemoperfusion.
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