Hiroshima Minami High School

In 2017, a large outbreak of Legionnaires' disease, involving 58 patients, occurred in a public bath facility in Hiroshima Prefecture, Japan. We analyzed 94 Legionella pneumophila strains isolated from patients and the public bath facility using molecular typing methods, including Pulsed-Field Gel Electrophoresis, sequence-based typing, multi-locus variable number tandem repeat analysis, and Whole-Genome Sequencing (WGS). Genotypes obtained using these molecular epidemiological typing methods were highly correlated with each other. L. pneumophila strains of various genotypes were isolated from the public bath facility, of which only ST2398 and ST2399 were isolated from patients. ST2398 and ST2399, isolated from patients, bath water, and swabs, derived from one common circulating system at the bath facility out of seven were found to be novel genotypes and a highly clonal genetic lineage by single nucleotide variant (SNV) analysis based on WGS. The result of haplotype network analysis based on SNVs showed that ST2398 and ST2399 differed only approximately 30-42 SNVs, and some environmental strains that differed by only 0-3 SNVs from patient strains were isolated. These results demonstrated that this outbreak was caused by L. pneumophila assigned to the ST2398 and ST2399 clades. We found that at least three patients were co-infected with different clusters of L. pneumophila serogroup 1. Our results show that several strains must be isolated from a single sample to consider the accumulation of mutations in water and co-infection when investigating outbreaks.

Designing and carrying out a controlled human infection (CHI) model for hepatitis C virus (HCV) is critical for vaccine development. However, key considerations for a CHI model protocol include understanding of the earliest viral-host kinetic events during the acute phase and susceptibility of the viral isolate under consideration for use in the CHI model to antiviral treatment before any infections in human volunteers can take place. Humanized mouse models lack adaptive immune responses but provide a unique opportunity to obtain quantitative understanding of early HCV kinetics and develop mathematical models to further understand viral and innate immune response dynamics during acute HCV infection. We show that the models reproduce the measured HCV kinetics in humanized mice, which are consistent with early acute HCV-host dynamics in immunocompetent chimpanzees. Our findings suggest that humanized mice are well-suited to support development of a CHI model. In-silico and in-vivo modeling estimates provide a starting point to characterize candidate viruses for testing in CHI model studies.

[This corrects the article DOI: 10.1007/s10616-024-00637-y.].

Ribonucleoside triphosphates are often incorporated into genomic DNA during DNA replication. The accumulation of unrepaired ribonucleotides is associated with genomic instability, which is mediated by DNA topoisomerase 1 (Top1) processing of embedded ribonucleotides. The cleavage initiated by Top1 at the site of a ribonucleotide leads to the formation of a Top1-DNA cleavage complex (Top1cc), occasionally resulting in a DNA double-strand break (DSB). In humans, tyrosyl-DNA phosphodiesterases (TDPs) are essential repair enzymes that resolve the trapped Top1cc followed by downstream repair factors. However, there is limited cellular evidence of the involvement of TDPs in the processing of incorporated ribonucleotides in mammals. We assessed the role of TDPs in mutagenesis induced by a single ribonucleotide embedded into DNA. A supF shuttle vector site-specifically containing a single riboguanosine (rG) was introduced into the human lymphoblastoid TK6 cell line and its TDP1-, TDP2-, and TDP1/TDP2-deficient derivatives. TDP1 and TDP2 insufficiency remarkably decreased the mutant frequency caused by an embedded rG. The ratio of large deletion mutations induced by rG was also substantially lower in TDP1/TDP2-deficient cells than wild-type cells. Furthermore, the disruption of TDPs reduced the length of rG-mediated large deletion mutations. The recovery ratio of the propagated plasmid was also increased in TDP1/TDP2-deficient cells after the transfection of the shuttle vector containing rG. The results suggest that TDPs-mediated ribonucleotide processing cascade leads to unfavorable consequences, whereas in the absence of these repair factors, a more error-free processing pathway might function to suppress the ribonucleotide-induced mutagenesis. Furthermore, base substitution mutations at sites outside the position of rG were detected in the supF gene via a TDPs-independent mechanism. Overall, we provide new insights into the mechanism of mutagenesis induced by an embedded ribonucleotide in mammalian cells, which may lead to the fatal phenotype in the ribonucleotide excision repair deficiency.

A relationship between serum magnesium (Mg) and body composition parameters has not been reported in hemodialysis (HD) patients. We aimed to clarify whether serum Mg has any association with body composition parameters, or survival in HD patients. This study included 215 consecutive maintenance HD patients. Laboratory data collection and postdialysis body composition analysis were performed at baseline. The patients were divided based on baseline serum Mg level tertiles (low, medium, and high Mg groups). Kaplan-Meier survival, logistic regression analyses and Cox proportional hazard analyses were conducted. Among all patients, the median age and dialysis vintage were 73 (65-81) years and 44 (8-96) months, respectively. The serum Mg levels were < 2.3, 2.3-2.5, and > 2.5 mg/dL for the low (n = 67), middle (n = 76), and high (n = 72) Mg groups, respectively. Compared to other groups, low Mg group showed significantly higher age and C-reactive protein levels, but lower serum albumin, normalized protein catabolic rates and frequency of on-line hemodiafiltration. The low, middle, and high Mg groups differed significantly regarding body cell mass (fat-free mass without bone mineral mass and extracellular water) index (BCMI): [5.6 (4.2-6.8), 6.0 (4.8-8.1), 6.7 (4.9-7.5) kg/m2 , respectively] and overhydration/extracellular water ratio (OH/ECW) [11.7 (4.5-21.9), 4.8 (1.0-14.1), 8.5 (-0.5-15.0) %, respectively] but not regarding body mass index, lean tissue index, fat tissue index. Hypomagnesemia was significantly associated with BCMI [odds ratio (OR) [95% confidence interval (CI)]: 0.85 [0.73-1.00] and OH/ECW (OR [95% CI]: 1.03 [1.01-1.05]), respectively. Kaplan-Meyer 3-year survival rates were 53.6%, 69.7%, and 71.7% in low, middle, and high Mg groups, respectively. However, hypomagnesemia was not significantly associated with 3-year all-cause mortality independent of age, serum albumin and C-reactive protein. Hypomagnesemia was associated with lower BCMI, more pronounced OH/ECW and poorer Kaplan-Meier 3-year cumulative survival, but was not an independent risk factor for mortality in HD patients.

Tumors affecting the liver are rare in fetal and infant life, with hemangioma being the most common1. Fetal hepatic hemangiomas on two-dimensional (2D) ultrasound are well-defined, mixed solid and cystic tumors with punctate calcifications in 50% of the mass. Hypoechoic areas represent vascular structures with low resistance on color Doppler imaging2. Here we describe our experience of HDlive Flow with HDlive silhouette mode in diagnosing fetal hepatic hemangioma in the third trimester of pregnancy. A 28-year-old Japanese woman, gravida 3 para 1, was referred to our clinic at 29 + 3 weeks of gestation because of a suspected fetal intra-abdominal tumor. Ultrasound examination (Voluson E10, GE Healthcare Japan, Tokyo, Japan) revealed on 2D imaging an intra-abdominal, well-defined, mixed solid tumor (45 × 40 × 23 mm) with cystic lesions and punctate calcification, located on the left side of the fetal stomach (Figure 1a). Imaging with HD-Flow demonstrated moderate blood flow within the mass (Figure 1b). HDlive Flow with HDlive silhouette mode at 30 + 2 weeks demonstrated a vascular pattern within the mass characterized by multiple, closely packed blood vessels with differing directions of blood flow, giving a pomegranate-like appearance (Figure 2 and Videoclip S1). The feeder artery was identified clearly originating from the celiac artery. Magnetic resonance imaging (MRI) showed a well-defined, hypervascularized tumor on the left side of the liver (Figure S1). A diagnosis of fetal hepatic hemangioma was suggested. At 37 + 2 weeks, elective Cesarean section was performed to avoid possible intrapartum rupture of the fetal mass. A female neonate was delivered, weighing 2676 g with a length of 49 cm. Apgar scores at 1 and 5 min were 8 and 9, respectively, and umbilical artery pH was 7.334. Postnatal 2D sonography 1 day after delivery confirmed the diagnosis of hepatic hemangioma. Further examination with computed tomography and MRI were declined by the parents. Follow-up 2D sonography revealed spontaneous regression of the tumor, and the mass had disappeared completely 2 months later. Hemangioma can be identified on 2D sonography and color Doppler by its characteristic mixed solid and cystic nature with abundant blood flow3. These features differentiate it from mesenchymal hamartoma, which usually has several cysts separated by thick septa with an absence of arteriovenous malformations4, and hepatoblastoma, which appears as a well-defined, lobulated, solid mass with a wheel-spoke appearance5. HDlive Flow is a new technology which can be used to reconstruct a spatial three-dimensional (3D) image of fetal and placental blood vessels6. In the present case, 2D grayscale and color Doppler (HD-Flow) showed the classic diagnostic pattern of hemangioma, including a mixed solid and cystic tumor with abundant blood flow and punctate calcification. HDlive Flow with HDlive silhouette mode provided spatial 3D images of the highly vascular pattern in the tumor, giving a pomegranate-like appearance, and the feeder artery and its origin from the celiac artery were also identified. Spatial relationships between the tumor and surrounding anatomical landmarks, such as the spine, diaphragm, descending aorta, inferior vena cava and umbilical vein were also visualized. Use of HDlive Flow with HDlive silhouette mode to visualize the characteristic vascular pattern of a fetal hepatic hemangioma has not been reported previously. However, conclusions regarding its diagnostic role should be drawn with caution given that this finding was an observation in a single case and no comparison was made with other fetal liver tumors. This unique vascular pattern might provide additional clues for the prenatal diagnosis and follow-up of hepatic hemangioma, which, in the majority of cases, regresses spontaneously after birth7. T.H. is supported by a Grant-in-Aid for scientific Research on Innovative Areas ‘Constructive Developmental Science’ (No. 24119004) from The Ministry of Education, Culture, Sports, Science and Technology, Japan. C. Tenkumo†, U. Hanaoka†, M. A. M. AboEllail†, M. Ishimura‡, M. Morine§, K. Maeda§ and T. Hata*† †Department of Perinatology and Gynecology, Kagawa University Graduate School of Medicine, 1750-1 Ikenobe, Miki, Kagawa 761-0793, Japan; ‡Department of Ultrasound, Hiroshima Branch, GE Healthcare Japan, Nishihara, Asaminami-Ku, Hiroshima, Japan; §Department of Obstetrics, General Perinatal Medical Center, Shikoku Medical Center for Children and Adults, Zentsuji City, Kagawa, Japan *Correspondence. (e-mail: [email protected]) Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Alström syndrome (AS) is a rare, autosomal recessive disorder characterized by progressive cone-rod dystrophy, childhood obesity, sensorineural hearing impairment, type 2 diabetes, hypogonadism, and additional abnormalities. Herein we report a 29-year-old man with progressive cone-rod dystrophy, hearing impairment, liver cirrhosis, bilateral cryptorchidism with hypergonadotropic hypogonadism, and type2 diabetes. He had severe insulin resistance and required high-dose insulin to treat his hyperglycemia. Genetic testingrevealed a mutation in exon 8 (c.4746C > A) of the Alström syndrome protein 1 (ALMS1) gene and this is the first report of this mutation in AS. It is difficult to lead to correct diagnosis without genetic test, and physicians should suspect AS when patients show early onset visual dysfunction, obesity, or type 2 diabetes.

Multiplex reverse transcription (RT)-polymerase chain reaction (PCR)-based assays involving fluorescent dye-labeled primers were modified to detect 10 types of gastroenteritis viruses by adding two further assays to a previously developed assay. Then, these assays were applied to clinical samples, which were collected between January 2006 and December 2013. All 10 types of viruses were effectively detected in the multiplex RT-PCR-based assays. In addition, various viral parameters, such as the detection rates and age distributions of each viral type, were examined. The frequency and types of mixed infections were also investigated. Among the 186 virus-positive samples, genogroup II noroviruses were found to be the most common type of virus (32.7%), followed by group A rotaviruses (10.6%) and parechoviruses (10.3%). Mixed infections were observed in 37 samples, and many of them were detected in patients who were less than 2 years old. These observations showed that the multiplex RT-PCR-based assays involving fluorescent dye-labeled primers were able to effectively detect the viruses circulating among pediatric acute gastroenteritis patients and contributed to the highly specific and sensitive diagnosis of gastroenteritis. J. Med. Virol. 89:791-800, 2017. © 2016 Wiley Periodicals, Inc.

Radiochromic films are important tools for assessing complex dose distributions. Gafchromic EBT‐XD films have been designed for optimal performance in the 40–4,000 cGy dose range. We investigated the dosimetric characteristics of these films, including their dose‐response, postexposure density growth, and dependence on scanner orientation, beam energy, and dose rate with applications to high‐dose volumetric‐modulated arc therapy (VMAT) verification. A 10 MV beam from a TrueBeam STx linear accelerator was used to irradiate the films with doses in the 0–4,000 cGy range. Postexposure coloration was analyzed at postirradiation times ranging from several minutes to 48 h. The films were also irradiated with 6 MV (dose rate (DR): 600 MU/min), 6 MV flattening filter‐free (FFF) (DR: 1,400 MU/ min), and 10 MV FFF (DR: 2,400 MU/min) beams to determine the energy and dose‐rate dependence. For clinical examinations, we compared the dose distribution measured with EBT‐XD films and calculated by the planning system for four VMAT cases. The red channel of the EBT‐XD film exhibited a wider dynamic range than the green and blue channels. Scanner orientation yielded a variation of ∼3% in the net optical density (OD). The difference between the film front and back scan orientations was negligible, with variation of ∼1.3% in the net OD. The net OD increased sharply within the first 6 hrs after irradiation and gradually afterwards. No significant difference was observed for the beam energy and dose rate, with a variation of ∼1.5% in the net OD. The gamma passing rates (at 3%, 3 mm) between the film‐ measured and treatment planning system (TPS)‐calculated dose distributions under a high dose VMAT plan in the absolute dose mode were more than 98.9%.PACS number(s): 87.56 Fc