Acute onset of constrictive pericarditis due to acute myelomonocytic leukemia: A case and literature review.

We herein present a fatal case of constrictive pericarditis (CP) due to acute myelomonocytic leukemia (AMML) in a patient who initially complained of an acute onset of chest pain two days after COVID-19 vaccination. An autopsy revealed pericardial infiltration of leukemic cells. CP is rarely associated with leukemia and only 14 cases have been reported in the literature. The etiology of CP in previous reports included leukemic infiltration, graft-versus-host disease, drug-induced, post-radiation, autoimmune, and otherwise unidentified. This case indicates that leukemic infiltration can cause CP and that clinicians should include leukemia in the differential diagnosis of CP.

A case of breast angiosarcoma clearly delineated by contrast-enhanced ultrasonography.

We present a case of breast angiosarcoma. Although B-mode ultrasonography did not indicate a tumor, contrast-enhanced ultrasonography (CEUS) was successfully delineated it. CEUS helped identify the tumor and its extent.

Development of Visible-Light-Responsive RNA Scissors Based on a 10-23 DNAzyme.

The 10-23 DNAzyme is an artificially developed functional oligonucleotide that can cleave RNA in a sequence-specific manner. In this study, we designed a new photo-driven DNAzyme incorporating a photoresponsive DNA overhang complementary to the catalytic core region. The photoresponsive overhang region of the DNAzyme included either azobenzene components (Azos) or 2,6-dimethyl-4-(methylthio)azobenzene units (SDM-Azos) each attached to a d-threoninol linker. When the Azos or SDM-Azos were in the trans form, the photoresponsive DNA overhang hybridized with the DNAzyme, and the RNA cleavage activity was suppressed. cis Isomerization of Azos or SDM-Azos, induced by 365 or 400 nm light, respectively, destabilized the duplex between the photoresponsive overhang and the catalytic core, and the DNAzyme recovered RNA cleavage activity. Reversible photoswitching of the DNAzyme activity was achieved by use of specific light irradiation. Further, light-dependent photoswitching of protein expression in the presence of the DNAzyme was demonstrated. Thus, this photo-driven DNAzyme has potential for application as a photocontrolled gene silencing system and a photoactivatable gene expression system.

Photoswitch nucleic acid catalytic activity by regulating topological structure with a universal supraphotoswitch.

We demonstrated the generality of a strategy for photoswitching the activity of functional oligonucleotides by modulating their topological structure. Our strategy was proved to be versatile because it can be used to photoregulate functional oligonucleotides, e.g., ribozymes and DNAzymes, which have two binding arms and a catalytic loop. Repeated reversible photoregulation of RNA cleavage by a ribozyme or a DNAzyme was achieved by attaching two photoresponsive strands, artificial oligomers involving azobenzene moieties and nucleobases capable of forming a duplex as the supraphotoswitch. Individual strands were attached to the 3' and 5' ends of a RNA-cleavage oligonucleotide. Thus, the topological structure of the ribozyme or DNAzyme was constrained, and RNA cleavage was greatly suppressed when the supraphotoswitch duplex formed (OFF state). In contrast, RNA cleavage resumed when the supraphotoswitch duplex dissociated (ON state). Light irradiation was used to repeatedly switch the supraphotoswitch between the ON and OFF states so that RNA cleavage activity could be efficiently photoregulated. Analysis of the regulatory mechanism showed that topological constraints suppressed the RNA cleavage by causing both structural changes at the catalytic site and lower binding affinity between the RNA substrates and the functional oligonucleotides.

[Intractable duodenocutaneous fistula after nephrectomy for stone pyonephrosis: report of a case].

A 56-year-old woman was admitted to our hospital for treatment of right stone pyonephrosis with a perirenal abscess. After right nephrectomy for the pyonephrosis, the patient suffered from post-operative bleeding, which was stopped by closing off the drain tube with a clamp. However, a right retroperitoneal abscess with gas formation developed nine days after the operation, necessitating an operative procedure for drainage. Pus culture revealed Staphylococcus epidermidis and Candida albicans. Discharge from the drain tube became dark green days after the drainage procedure. Upper gastrointestinal series revealed a duodenal fistula, which could not be closed using a retroperitoneal approach, so the operative wound was left open. Because of the volume of discharge (800-1,400 ml/day), somatostatin analogue, 100 micrograms, was injected subcutaneously twice a day. Discharge decreased by one-half within 2 weeks of the administration of somatostatin analogue. However, the duodenocutaneous fistula had not resolved over a period of 8 months. Since the patient developed acute cholecystitis, both cholecystectomy and closure of the duodenocutaneous fistula were performed transperitoneally. The duodenocutaneous fistula, which was closed with Endo GIA (35 mm), had protruded from a descending portion of the duodenum like the diverticulum. The postoperative course was uneventful. We speculated that the fistula occurred as a result of the inflammation with the abscess formation.