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Abstract Background Fechtner syndrome, also referred to as nonmuscle myosin heavy chain 9-related disease (MYH9-RD), is an autosomal-dominant genetic disorder. It is caused by abnormalities in the MYH9 gene, which encodes the nonmuscle conventional (class II) myosin heavy chain A (NMMHC-IIA). Its clinical manifestations include mild macrothrombocytopenia with leukocyte inclusions, hearing loss, cataracts, and renal failure. Case presentation We present the case of a 34-year-old female patient with Fechtner syndrome in whom end-stage renal disease (ESRD) developed. During childhood, she presented with the typical symptoms of MYH9-RD, including thrombocytopenia, leukocyte inclusion bodies, onset of nephropathy, sensorineural hearing loss, and cataracts, wherein a clinical diagnosis of Fechtner syndrome was established. Her renal function deteriorated during adolescence. Furthermore, the patient underwent renal biopsy at the age of 18 years, which revealed focal segmental glomerulosclerosis. She was started on hemodialysis at the age of 33 years, followed by a living-donor renal transplantation after 5 months. She achieved a target platelet count of 50 × 109/L for arteriovenous fistula creation and 100 × 109/L for renal transplantation via platelet transfusions. Heparin use was avoided as an anticoagulant during hemodialysis. Since the patient expressed a desire for childbearing, genetic testing was performed, revealing an in-frame deletion of 21 nucleotides at 3195–3215 in exon 25 (A1065_A1072 del) of NMMHC-IIA, which has been reported to correlate with mild renal dysfunction. Our patient’s condition progressed into ESRD. Although genetic testing techniques have made great strides in recent years, our case clearly presents the difficulty in assuming an association between genetic abnormalities and clinical manifestations. Conclusions Our case may provide further understanding of the management of ESRD in patients with MYH9-RD-related thrombocytopenia based on the results of genetic testing.

This research aims to elucidate the physiological mechanisms behind the accidental acquisition of high-concentration cesium ions (Cs+) tolerance of Escherichia coli and apply this understanding to develop bioremediation technologies. Bacterial Cs+ resistance has attracted attention, but its physiological mechanism remains largely unknown and poorly understood. In a prior study, we identified the Cs+/H+ antiporter TS_CshA in Microbacterium sp. TS-1, resistant to high Cs+ concentrations, exhibits a low Cs+ affinity with a Km value of 370 mM at pH 8.5. To enhance bioremediation efficacy, we conducted random mutagenesis of TS_cshA using Error-Prone PCR, aiming for higher-affinity mutants. The mutations were inserted downstream of the PBAD promoter in the pBAD24 vector, creating a mutant library. This was then transformed into E. coli-competent cells. As a result, we obtained a Cs+-resistant strain, ZX-1, capable of thriving in 400 mM CsCl—a concentration too high for ordinary E. coli. Unlike the parent strain Mach1™, which struggled in 300 mM CsCl, ZX-1 showed robust growth even in 700 mM CsCl. After 700 mM CsCl treatment, the 70S ribosome of Mach1™ collapsed, whereas ZX-1 and its derivative ΔZX-1/pBR322ΔAp remained stable. This means that the ribosomes of ZX-1 are more stable to high Cs+. The inverted membrane vesicles from strain ZX-1 showed an apparent Km value of 28.7 mM (pH 8.5) for Cs+/H+ antiport activity, indicating an approximately 12.9-fold increase in Cs+ affinity. Remarkably, the entire plasmid isolated from ZX-1, including the TS_cshA region, was mutation-free. Subsequent whole-genome analysis of ZX-1 identified multiple SNPs on the chromosome that differed from those in the parent strain. No mutations in transporter-related genes were identified in ZX-1. However, three mutations emerged as significant: genes encoding the ribosomal bS6 modification enzyme RimK, the phage lysis regulatory protein LysB, and the flagellar base component protein FlgG. These mutations are hypothesized to affect post-translational modifications, influencing the Km value of TS_CshA and accessory protein expression. This study unveils a novel Cs+ resistance mechanism in ZX-1, enhancing our understanding of Cs+ resistance and paving the way for developing technology to recover radioactive Cs+ from water using TS_CshA-expressing inverted membrane vesicles.

AbstractA decreased body mass index (BMI) over time is associated with a poor prognosis for patients on hemodialysis. We aimed to examine whether this association also applies to patients with peritoneal dialysis (PD). BMI change was defined as the percentage change in the BMI between the time of PD catheter insertion and six months after its insertion. The association between the BMI change and all-cause mortality or PD discontinuation from six months after PD catheter insertion until October 2021 was investigated. This retrospective cohort study included 122 patients (aged 61.1 ± 12.1 years; 90 males) who underwent PD catheter insertion between January 2008 and March 2020. The median follow-up period was 43.1 (21.2–78.8) months. The median six-month percentage change in the BMI was −2.14 (−5.56–1.84)%, and patients were categorized into tertiles based on their BMI changes. The fully-adjusted Cox regression analysis revealed a significantly higher rate of PD discontinuation or all-cause mortality (hazard ratio (HR): 2.48; 95%; confidence interval (CI): 1.41–4.37) in patients with the lowest tertile (T1, BMI change: 0.67%) than those in the T2 group (HR: 1.18; 95% CI: 0.66–2.11). A decreased BMI over time is independently associated with HD transfer or all-cause mortality among patients initiating PD, which highlights the importance of the 6-month BMI change as a novel prognostic marker.

Idiopathic multicentric Castleman disease (iMCD) is a systemic and polyclonal lymphoproliferative disease involving multiple organs, including the kidneys, due to the overproduction of interleukin-6 (IL-6). Recently, several reports have suggested that excessive IL-6 actions in iMCD could have a causal relationship with the development of diverse histopathological renal manifestations that cause nephrotic syndrome. However, the treatment for such cases remains unclear. We report a series of three cases of nephrotic syndrome due to iMCD that helps to delineate the importance of early and continuous therapy with the anti-interleukin-6 receptor antibody tocilizumab. First, treatment was suspended for infectious control, and the patient presented with nephrotic syndrome due to diffuse mesangial and endocapillary hypercellularity without immune deposits complicating acute kidney injury. Second, iMCD was treated with prednisolone alone. The patient suddenly developed nephrotic syndrome due to immune-complex glomerulonephritis, not otherwise specified, complicated with acute kidney injury. In the third case, nephrotic syndrome secondary to membranous glomerulonephritis was diagnosed, with a skin rash and IgE antibodies to tocilizumab, and was therefore treated with prednisolone alone. In contrast to the first two cases, the third progressed to end-stage renal disease on hemodialysis. Taken together, this series suggests that clinicians should maintain clinical vigilance for iMCD as a possible underlying component of nephrotic syndrome, since iMCD presents with a variety of renal pathologies. Prompt initiation and continuous administration of tocilizumab are likely key determinants of renal outcomes in such cases. In particular, when tocilizumab is suspended due to infection or in the perioperative period, consideration of its expeditious resumption should be made, taking into account both the withdrawal period and systemic conditions.

Since the coronavirus disease 2019 (COVID-19) pandemic continues and a new variant of the virus has emerged, the COVID-19 vaccination campaign has progressed. Rare but severe adverse outcomes of COVID-19 vaccination such as anaphylaxis and myocarditis have begun to be noticed. Of note, several cases of new-onset antineutrophil cytoplasmic antibody-associated vasculitis (AAV) after COVID-19 mRNA vaccination have been reported. However, relapse of AAV in remission has not been recognized enough as an adverse outcome of COVID-19 vaccination. We report, to our knowledge, a first case of renal-limited AAV in remission using every 6-month rituximab administration that relapsed with pulmonary hemorrhage, but not glomerulonephritis, following the first dose of the Pfizer-BioNTech COVID-19 vaccine. The patient received the COVID-19 vaccine more than 6 months after the last dose of rituximab according to the recommendations. However, his CD19+ B cell counts were found to be increased after admission, indicating that our case might have been prone to relapse after COVID-19 vaccination. Although our case cannot establish causality between AAV relapse and COVID-19 mRNA vaccination, a high level of clinical vigilance for relapse of AAV especially in patients undergoing rituximab maintenance therapy following COVID-19 vaccination should be maintained. Furthermore, elapsed time between rituximab administration and COVID-19 mRNA vaccination should be carefully adjusted based on AAV disease-activity.

This research aims to elucidate the physiological mechanisms behind the accidental acquisition of high-concentration cesium ions (Cs+) tolerance of Escherichia coli and apply this understanding to develop bioremediation technologies. Bacterial Cs+ resistance has attracted attention, but its physiological mechanism remains largely unknown and poorly understood. In a prior study, we identified the Cs+/H+ antiporter TS_CshA in Microbacterium sp. TS-1, resistant to high Cs+ concentrations, exhibits a low Cs+ affinity with a Km value of 370  mM at pH 8.5. To enhance bioremediation efficacy, we conducted random mutagenesis of TS_cshA using Error-Prone PCR, aiming for higheraffinity mutants. The mutations were inserted downstream of the PBAD promoter in the pBAD24 vector, creating a mutant library. This was then transformed into E. coli-competent cells. As a result, we obtained a Cs+-resistant strain, ZX-1, capable of thriving in 400  mM CsCl—a concentration too high for ordinary E. coli. Unlike the parent strain Mach1™, which struggled in 300  mM CsCl, ZX-1 showed robust growth even in 700  mM CsCl. After 700  mM CsCl treatment, the 70S ribosome of Mach1™ collapsed, whereas ZX-1 and its derivative ΔZX1/pBR322ΔAp remained stable. This means that the ribosomes of ZX-1 are more stable to high Cs+. The inverted membrane vesicles from strain ZX-1 showed an apparent Km value of 28.7  mM (pH 8.5) for Cs+/H+ antiport activity, indicating an approximately 12.9-fold increase in Cs+ affinity. Remarkably, the entire plasmid isolated from ZX-1, including the TS_cshA region, was mutationfree. Subsequent whole-genome analysis of ZX-1 identified multiple SNPs on the chromosome that differed from those in the parent strain. No mutations in transporter-related genes were identified in ZX-1. However, three mutations emerged as significant: genes encoding the ribosomal bS6 modification enzyme RimK, the phage lysis regulatory protein LysB, and the flagellar base component protein FlgG. These mutations are hypothesized to affect posttranslational modifications, influencing the Km value of TS_CshA and accessory protein expression. This study unveils a novel Cs+ resistance mechanism in ZX-1, enhancing our understanding of Cs+ resistance and paving the way for developing technology to recover radioactive Cs+ from water using TS_CshAexpressing inverted membrane vesicles. [ABSTRACT FROM AUTHOR]

Objective: This study aims to evaluate the safety of a short hydration (SH) protocol during concurrent chemoradiotherapy (CCRT) with cisplatin for cervical cancer. While massive hydration is a standard for cisplatin chemotherapy to prevent renal toxicity, the safety of SH in the context of CCRT remains underexplored. Methods: We retrospectively reviewed cervical cancer patients undergoing cisplatin-based CCRT at two hospitals from January 2019 to August 2023, excluding those with poor performance status and pre-existing renal impairment. SH involved infusing up to 2 L of fluid within 5 hours on cisplatin days, while prolonged hydration (LH) exceeded this volume or this time. We compared serum creatinine levels (sCr, mg/dL) at baseline, after each cisplatin dose, and 3-6 months post-CCRT (long term) between the 2 groups. Results: Among 86 patients, 25 received SH, and 61 received LH. The SH group had a higher mean age than the LH group (49 vs. 56, p=0.047). There were no significant differences in body weight, stage, surgery ratio, and total cisplatin dose per body surface area between the 2 groups. None of the SH patients required cisplatin dose reduction or discontinuation due to nephrotoxicity, while one and 2 patients in the LH group, respectively. Mean sCr levels at baseline, the last cisplatin dose, and the long term were 0.62, 0.56, and 0.61 in SH, and 0.61, 0.66, and 0.67 in LH (p=0.72, p=0.04, and p=0.15, respectively). Conclusion: SH during CCRT for cervical cancer demonstrates no inferiority in safety compared to LH, with no significant increase in nephrotoxicity. [ABSTRACT FROM AUTHOR]