Systematic Study of Lattice Specific Heat of Filled Skutterudites

The lattice specific heat C lat of La-based filled skutterudites La T 4 X 12 ( T = Fe, Ru and Os; X = P, As, and Sb) has been systematically studied, and both the Debye temperature Θ D and the Einstein temperature Θ E of La T 4 X 12 were carefully estimated. We confirmed that a correlation exists between Θ D and the reciprocal of the square root of average atomic mass for La T 4 P 12 , La T 4 As 12 , and La T 4 Sb 12 . The Θ D of filled skutterudites was found to depend mainly on the nature of the species X forming the cage. The temperature dependence of C lat / T 3 for La T 4 X 12 exhibited a large broad maximum at low temperatures (10–30 K), which suggests a nearly dispersionless low-energy optical mode characterized by Einstein specific heat. Since no such broad maximum exists for the unfilled skutterudite RhP 3 , the low-energy optical modes are associated with vibration involving La ions in the X 12 cage (the so-called “guest ion modes”). The Θ E of filled skutterudites was found to roughly correspond to the energy of low-energy guest ion optical modes. Furthermore, a good correlation was shown to exist between Θ E and r R–X - r R3+ , where r R–X is the R – X distance and r R3+ is the effective ionic radius of R 3+ . As r R–X - r R3+ increased, Θ E was found to decrease

A CASE OF CORONAVIRUS DISEASE 2019 COMPLICATED BY VENTILATORASSOCIATED PNEUMONIA, LUNG ABSCESS, AND STAPHYLOCOCCUS AUREUS BACTEREMIA

Complications of healthcare-associated infections have been reported in patients with coronavirus disease 2019 (COVID-19). We encountered a case of ventilator-associated pneumonia and lung abscess, complicated with Staphylococcus aureus bacteremia and multiple abscesses, in a patient with COVID-19. Streptococci and anaerobes were cultured from the sputum, which was considered to be the causative organism of the lung abscess. In the management of severe COVID-19, care should be taken to prevent complications of healthcare-associated infections; when secondary respiratory tract infections are suspected, the presence of lung abscess and anaerobic culture should be considered

Acute Fulminant Necrotizing Amebic Colitis and Enterocolitis Associated with Perforation in a Male Breast Cancer Patient

In Japan, amebiasis is typically found in men who have sex with men and in individuals with recent travel to endemic areas. We experienced a patient with fulminant necrotizing amebic colitis and enterocolitis who presented with a severe disorder of the liver and renal function. The patient was a 71-year-old man who had lived in Yokohama City, Japan for 30 years. His stool sample showed no amebic dysentery protozoa and cultured negatively for human immunodeficiency virus. Despite being treated with meropenem, pyrexia of 39-40°C continued for 4 days. On hospital day 8, a colonic abscess and perforation of the transverse colon were detected by computed tomography（CT）. His fever did not improve, suggesting progression of infectious disease. Subsequent emergency laparotomy revealed a perforation in the middle of the transverse colon. Peritoneal lavage and right hemicolectomy were performed; however, a CT scan on hospital day 16 （postoperative day 8） showed re-perforation of the colon and an abscess around the site of anastomosis, prompting emergency intestinal and left hemicolectomy resection. Amebae observed pathologically during the second emergency operation led to a diagnosis of amebic colitis. Endotoxin adsorption therapy was performed, and metronidazole was administered. Despite prompt diagnosis and treatments, the patient’s general conditions became fulminant, and multiple organ failure developed. On hospital day 18 （postoperative day 10）, his C-reactive protein level was 20mg/dl. He was clinically diagnosed as having sepsis and multiple organ failure. The patient died on hospital day 23. Acute colitis is commonly encountered in daily practice, but it is difficult to differentiate between amebic and non-amebic colitis preoperatively and thus, the possibility of amebic colitis should be considered in such clinical presentations

A Case of Intestinal Obstruction Secondary to a Strangulated Obturator Hernia in an Elderly Woman

In this report, we present a case of intestinal obstruction secondary to a strangulated obturator hernia in an elderly woman. An 88-year-old woman was admitted to our hospital because she had been experiencing abdominal pain and vomiting for 24h. Her abdomen was distended, and bowel sounds indicating obstruction were heard on auscultation. Diffuse abdominal tenderness was present, but no palpable masses were apparent. The diagnosis of an obturator hernia was confirmed preoperatively by computed tomography. During the emergency laparotomy, the incarcerated intestine was reduced and removed. The obturator foramen was repaired using a simple suture. The patient recovered completely and was discharged seven days after the surgical procedure because no postoperative complications occurred. An early diagnosis and prompt surgical treatment are important to reduce the morbidity and mortality associated with an obturator hernia

A Case of Giant Mesenteric Cyst Originating from the Small Intestine

A 62-year-old man was admitted to Showa University Fujigaoka Hospital because of a giant mass that was discovered approximately 8 weeks after the development of obvious symptoms, namely upper abdominal pain, vomiting, and progressive distension. Ultrasonography revealed a giant cystic mass that was occupying the right upper abdomen, and contrast-enhanced computed tomography revealed a huge, relatively well-defined, and low-density cystic mass that measured 10cm in diameter. Radical resection of the tumor was performed via open laparotomy, along with segmental small intestine resection to address potential invasion into adjacent tissues. Histological findings of the resected specimen indicated mesenteric cyst. The patient\u27s postoperative recovery was uneventful and he was discharged after 11 days. At the 12-month follow-up, the patient was in good health with no signs of recurrence

BRCA1 Directs the Repair Pathway to Homologous Recombination by Promoting 53BP1 Dephosphorylation

Summary: BRCA1 promotes homologous recombination (HR) by activating DNA-end resection. By contrast, 53BP1 forms a barrier that inhibits DNA-end resection. Here, we show that BRCA1 promotes DNA-end resection by relieving the 53BP1-dependent barrier. We show that 53BP1 is phosphorylated by ATM in S/G2 phase, promoting RIF1 recruitment, which inhibits resection. 53BP1 is promptly dephosphorylated and RIF1 released, despite remaining unrepaired DNA double-strand breaks (DSBs). When resection is impaired by CtIP/MRE11 endonuclease inhibition, 53BP1 phosphorylation and RIF1 are sustained due to ongoing ATM signaling. BRCA1 depletion also sustains 53BP1 phosphorylation and RIF1 recruitment. We identify the phosphatase PP4C as having a major role in 53BP1 dephosphorylation and RIF1 release. BRCA1 or PP4C depletion impairs 53BP1 repositioning, EXO1 recruitment, and HR progression. 53BP1 or RIF1 depletion restores resection, RAD51 loading, and HR in PP4C-depleted cells. Our findings suggest that BRCA1 promotes PP4C-dependent 53BP1 dephosphorylation and RIF1 release, directing repair toward HR. : Following induction of DNA double-strand break, a pro-end-joining environment is created in G2 by transient 53BP1 phosphorylation and RIF1 recruitment. Here, Isono et al. show that, if timely repair does not ensue, BRCA1 promotes 53BP1 dephosphorylation and RIF1 release, favoring repair by homologous recombination. Keywords: ATM, DNA-end resection, BRCA1, 53BP1, RIF1, PP4C, NHEJ, H

Mutational spectrum of hepatitis C virus in patients with chronic hepatitis C determined by single molecule real-time sequencing

The emergence of hepatitis C virus (HCV) with resistance-associated substitution (RAS), produced by mutations in the HCV genome, is a major problem in direct acting antivirals (DAA) treatment. This study aimed to clarify the mutational spectrum in HCV-RNA and the substitution pattern for the emergence of RASs in patients with chronic HCV infection. HCV-RNA from two HCV replicon cell lines and the serum HCV-RNA of four non-liver transplant and four post-liver transplant patients with unsuccessful DAA treatment were analyzed using high-accuracy single-molecule real-time long-read sequencing. Transition substitutions, especially A>G and U>C, occurred prominently under DAAs in both non-transplant and post-transplant patients, with a mutational bias identical to that occurring in HCV replicon cell lines during 10-year culturing. These mutational biases were reproduced in natural courses after DAA treatment. RASs emerged via both transition and transversion substitutions. NS3-D168 and NS5A-L31 RASs resulted from transversion mutations, while NS5A-Y93 RASs was caused by transition substitutions. The fidelity of the RNA-dependent RNA polymerase, HCV-NS5B, produces mutational bias in the HCV genome, characterized by dominant transition mutations, notably A>G and U>C substitutions. However, RASs are acquired by both transition and transversion substitutions, and the RASs-positive HCV clones are selected and proliferated under DAA treatment pressure

Simultaneous Sinus Lifting and Alveolar Distraction of a Severely Atrophic Posterior Maxilla for Oral Rehabilitation with Dental Implants

We retrospectively reviewed a new preimplantation regenerative augmentation technique for a severely atrophic posterior maxilla using sinus lifting with simultaneous alveolar distraction, together with long-term oral rehabilitation with implants. We also analyzed the regenerated bone histomorphologically. This study included 25 maxillary sinus sites in 17 patients. The technique consisted of alveolar osteotomy combined with simultaneous sinus lifting. After sufficient sinus lifting, a track-type vertical alveolar distractor was placed. Following a latent period, patient self-distraction was started. After the required augmentation was achieved, the distractor was left in place to allow consolidation. The distractor was then removed, and osseointegrated implants (average of 3.2 implants per sinus site, 80 implants) were placed. Bone for histomorphometric analysis was sampled from six patients and compared with samples collected after sinus lifting alone as controls (n=4). A sufficient alveolus was regenerated, and all patients achieved stable oral rehabilitation. The implant survival rate was 96.3% (77/80) after an average postloading followup of 47.5 months. Good bone regeneration was observed in a morphological study, with no significant difference in the rate of bone formation compared with control samples. This new regenerative technique could be a useful option for a severely atrophic maxilla requiring implant rehabilitation