40 research outputs found
Usefulness of Microcatheters Inserted Overnight for Additional Injection of Sclerosant after Initial Balloon-Occluded Retrograde Transvenous Obliteration of Gastric Varices
In patients with large gastric varices, dose limitation of the sclerosant can cause difficulties in achieving complete thrombosis of varices during a single balloon-occluded retrograde transvenous obliteration (BRTO) procedure. For patients with incomplete variceal thrombosis after the first BRTO, additional sclerosant must be injected in a second BRTO. We report a successful case of BRTO for large gastric varices in whom additional sclerosant was injected through a microcatheter that remained inserted overnight. To achieve complete variceal thrombosis in a patient with incomplete thrombosis of large gastric varices after a first BRTO, a retained microcatheter can be used to inject additional sclerosant in a second BRTO the next day
Use of an Atrial Lead with Very Short Tip-To-Ring Spacing Avoids Oversensing of Far-Field R-Wave
The AVOID-FFS (Avoidance of Far-Field R-wave Sensing) study aimed to investigate whether an atrial lead with a very short tip-to-ring spacing without optimization of pacemaker settings shows equally low incidence of far-field R-wave sensing (FFS) when compared to a conventional atrial lead in combination with optimization of the programming.Patients receiving a dual chamber pacemaker were randomly assigned to receive an atrial lead with a tip-to-ring spacing of 1.1 mm or a lead with a conventional tip-to-ring spacing of 10 mm. Postventricular atrial blanking (PVAB) was programmed to the shortest possible value of 60 ms in the study group, and to an individually determined optimized value in the control group. Atrial sensing threshold was programmed to 0.3 mV in both groups. False positive mode switch caused by FFS was evaluated at one and three months post implantation.A total of 204 patients (121 male; age 73±10 years) were included in the study. False positive mode switch caused by FFS was detected in one (1%) patient of the study group and two (2%) patients of the control group (p = 0.62).The use of an atrial electrode with a very short tip-to-ring spacing avoids inappropriate mode switch caused by FFS without the need for individual PVAB optimization.ClinicalTrials.gov NCT00512915
Membrane-Bound IL-21 Promotes Sustained Ex Vivo Proliferation of Human Natural Killer Cells
NK cells have therapeutic potential for a wide variety of human malignancies. However, because NK cells expand poorly in vitro, have limited life spans in vivo, and represent a small fraction of peripheral white blood cells, obtaining sufficient cell numbers is the major obstacle for NK-cell immunotherapy. Genetically-engineered artificial antigen-presenting cells (aAPCs) expressing membrane-bound IL-15 (mbIL15) have been used to propagate clinical-grade NK cells for human trials of adoptive immunotherapy, but ex vivo proliferation has been limited by telomere shortening. We developed K562-based aAPCs with membrane-bound IL-21 (mbIL21) and assessed their ability to support human NK-cell proliferation. In contrast to mbIL15, mbIL21-expressing aAPCs promoted log-phase NK cell expansion without evidence of senescence for up to 6 weeks of culture. By day 21, parallel expansion of NK cells from 22 donors demonstrated a mean 47,967-fold expansion (median 31,747) when co-cultured with aAPCs expressing mbIL21 compared to 825-fold expansion (median 325) with mbIL15. Despite the significant increase in proliferation, mbIL21-expanded NK cells also showed a significant increase in telomere length compared to freshly obtained NK cells, suggesting a possible mechanism for their sustained proliferation. NK cells expanded with mbIL21 were similar in phenotype and cytotoxicity to those expanded with mbIL15, with retained donor KIR repertoires and high expression of NCRs, CD16, and NKG2D, but had superior cytokine secretion. The mbIL21-expanded NK cells showed increased transcription of the activating receptor CD160, but otherwise had remarkably similar mRNA expression profiles of the 96 genes assessed. mbIL21-expanded NK cells had significant cytotoxicity against all tumor cell lines tested, retained responsiveness to inhibitory KIR ligands, and demonstrated enhanced killing via antibody-dependent cell cytotoxicity. Thus, aAPCs expressing mbIL21 promote improved proliferation of human NK cells with longer telomeres and less senescence, supporting their clinical use in propagating NK cells for adoptive immunotherapy
Thiolutin is a zinc chelator that inhibits the Rpn11 and other JAMM metalloproteases
Thiolutin is a disulfide-containing antibiotic and anti-angiogenic compound produced by Streptomyces. Its biological targets are not known. We show that reduced thiolutin is a zinc chelator that inhibits the JAB1/MPN/Mov34 (JAMM) domain–containing metalloprotease Rpn11, a deubiquitinating enzyme of the 19S proteasome. Thiolutin also inhibits the JAMM metalloproteases Csn5, the deneddylase of the COP9 signalosome; AMSH, which regulates ubiquitin-dependent sorting of cell-surface receptors; and BRCC36, a K63-specific deubiquitinase of the BRCC36-containing isopeptidase complex and the BRCA1–BRCA2-containing complex. We provide evidence that other dithiolopyrrolones also function as inhibitors of JAMM metalloproteases
Accumulation of somatic mutations in TP53 in gastric epithelium with Helicobacter pylori infection.
BACKGROUND & AIMS: Helicobacter pylori infection is a risk factor for gastric cancer. To explore the genetic basis of gastric cancer that develops in inflamed gastric mucosa, we investigated genetic aberrations that latently accumulate in nontumorous gastric epithelium with H pylori infection. METHODS: We performed whole-exome sequencing of gastric tumors, noncancerous tissues with gastritis, and peripheral lymphocytes from 5 patients. We performed additional deep-sequencing analyses of selected tumor-related genes using 34 gastritis mucosal samples from patients with or without gastric cancer. We also performed deep sequencing analyses of gastric mucosal tissues from mice that express transgenic human TP53 and constitutively express activation-induced cytidine deaminase (AICDA or AID) (human TP53 knock-in/AID-transgenic mice). RESULTS: Whole-exome sequencing revealed that somatic mutations accumulated in various genes in inflamed gastric tissues. Additional deep-sequencing analyses of tissues from regions of gastritis confirmed nonsynonymous low-abundance mutations in TP53 in 15 cases (44.1%) and ARID1A in 5 cases (14.7%). The mutations that accumulated in gastric mucosal tissues with H pylori-induced gastritis, as well as gastric tumors, were predominantly C:G>T:A transitions in GpCpX motifs-a marker of cytidine deamination induced by AID. Constitutive expression of AID in the gastric mucosa of mice led to mutations in the human TP53, at amino acid coding positions identical to those detected in human gastric cancers. CONCLUSIONS: Studies of gastric tumors and tissues from humans and mice indicate that somatic mutations accumulate in various genes in gastric mucosal tissues with H pylori infection. Increased cytidine deaminase activity in these tissues appears to promote the accumulation of these mutations and might promote gastric carcinogenesis in patients with H pylori infection
Prevention of long-lasting atrial fibrillation through antitachycardia pacing in DDDR pacemakers
Objective: The MINERVA trial showed that in pacemaker patients with atrial fibrillation (AF) history, DDDRP pacing combining three algorithms – (a) atrial antitachycardia pacing with Reactive ATP enabled, (b) atrial preventive pacing and (c) managed ventricular pacing (MVP)—may effectively delay progression to persistent/permanent AF compared with standard DDDR pacing. We performed a comparative non-randomised evaluation to evaluate if Reactive ATP can be the main driver of persistent/permanent AF reduction independently on preventive pacing. Methods: Thirty-one centres included consecutive dual-chamber pacemaker patients with AF history. Reactive ATP was programmed in all patients while preventive atrial pacing was not enabled. These patients were compared with the three groups of MINERVA randomised trial (Control DDDR, MVP, and DDDRP). The main endpoint was the incidence of AF longer than 7 consecutive days. Results: A total of 146 patients (73 years old, 54% male) were included and followed for a median observation period of 31 months. The 2-year incidence of AF > 7 days was 12% in the Reactive ATP group, very similar to that found in the DDDRP arm of the MINERVA trial (13.8%, P =.732) and significantly lower than AF incidence found in the MINERVA Control DDDR arm (25.8%, P =.012) and in the MINERVA MVP arm (25.9%, P =.025). Conclusions: In a real-world population of dual-chamber pacemaker patients with AF history, the use of Reactive ATP is associated with a low incidence of persistent AF, highlighting that the positive results of the MINERVA trial were related to the effectiveness of Reactive ATP rather than to preventive pacing
PRESENT STATUS OF PHOTO-CATHODE RF GUN SYSTEM AND ITS APPLICATIONS AT WASEDA UNIVERSITY*
High quality electron beam generation using photocathode rf gun system and its application experiments have been developed at Waseda University since 2002 fiscal year. Our system is a table-top size within 2 × 2 m 2 including the rf gun system and can generate about 4 MeV low emittance electron beam. This is applied for soft X-ray generation using laser Compton scattering and pulse radiolysis experiments based on the pump-probe technique. In case of the soft X-ray generation, the laser Compton scattering experiment between about 4.2 MeV electron beam and Nd:YLF laser light (1047 nm) is performed at 20 degrees interaction angle, so that about 300 eV soft X-ray is generated. In case of the pulse radiolysis experiment, the electron beam is used for the pump beam. The probe light is generated as white light by concentrating Nd:YLF laser light (1047 nm) on the water cell. The measurement with about 30 ps (FWHM) time resolution of this system is demonstrated for the absorption of hydrated electrons
Dithiolopyrrolone Antibiotic Formation Induced by Adding Valeric Acid to the Culture Broth of Saccharothrix algeriensis
Three new antibiotics were isolated from the fermentation broth of Saccharothrix algeriensis NRRL B-24137 and characterized as the dithiolopyrrolone derivatives valerylpyrrothine (1), isovalerylpyrrothine (2), and formylpyrrothine (3) as well as the known antibiotic aureothricin. The production of the dithiolopyrrolone derivatives was induced by adding valeric acid to the culture medium. The compounds exhibited moderate antimicrobial activity in vitro