Quantitative analysis of the roles of IRM cell adhesion molecules in column formation in the fly brain

The Drosophila visual center shows columnar structures, basic structural and functional units of the brain, that are shared with the mammalian cerebral cortex. Visual information received in the ommatidia in the compound eye is transmitted to the columns in the brain. However, the developmental mechanisms of column formation are largely unknown. The Irre Cell Recognition Module (IRM) proteins are a family of immunoglobulin cell adhesion molecules. The four Drosophila IRM proteins are localized to the developing columns, the structure of which is affected in IRM mutants, suggesting that IRM proteins are essential for column formation. Since IRM proteins are cell adhesion molecules, they may regulate cell adhesion between columnar neurons. To test this possibility, we specifically knocked down IRM genes in columnar neurons and examined the defects in column formation. We developed a system that automatically extracts the individual column images and quantifies the column shape. Using this system, we demonstrated that IRM genes play critical roles in regulating column shape in a core columnar neuron, Mi1. We also show that their expression in the other columnar neurons, Mi4 and T4/5, is essential, suggesting that the interactions between IRM proteins and multiple neurons shape the columns in the fly brain.

Early distribution of18 F-labeled AAV9 vectors in the cerebrospinal fluid after intracerebroventricular or intracisternal magna infusion in non-human primates

BACKGROUND

The delivery of adeno-associated virus (AAV) vectors via the cerebrospinal fluid (CSF) has emerged as a valuable method for widespread transduction in the central nervous system. Although infusion into the cerebral ventricles is a common protocol in preclinical studies of small animals, the cisterna magna has been recognized as an alternative target for clinical studies because it can be reached in a less invasive manner using an intrathecal catheter via the subarachnoid space from a lumbar puncture.

METHODS

We evaluated the early distribution of fluorine-18-labeled AAV9 vectors infused into the lateral ventricle or cisterna magna of four non-human primates using positron emission tomography. The expression of the green fluorescent protein was immunohistochemically determined.

RESULTS

In both approaches, the labeled vectors diffused into the broad arachnoid space around the brain stem and cervical spinal cord within 30 min. Both infusion routes efficiently transduced neurons in the cervical spinal cord.

CONCLUSIONS

For gene therapy that primarily targets the cervical spinal cord and brainstem, such as amyotrophic lateral sclerosis, cisterna magna infusion would be a feasible and effective administration method.

Novel quantitative software for automatically excluding red bone marrow on whole‐body magnetic resonance imaging in patients with metastatic prostate cancer: A pilot study

OBJECTIVES

To establish a novel quantitative method that automatically excludes the red bone marrow and accurately quantifies the tumor volume on whole-body magnetic resonance imaging using updated imaging software. To also evaluate the association between the quantified tumor volume and the prognosis of patients with metastatic prostate cancer.

METHODS

This prospective analysis included patients diagnosed with metastatic hormone-sensitive or metastatic castration-resistant prostate cancer between 2017 and 2022. We developed an imaging software (Attractive BD_Score) that analyzed whole-body diffusion-weighted and in-phase and opposed-phase T1-weighted images to automatically exclude the red bone marrow. The quantified tumor volume was compared with that quantified by traditional whole-body diffusion-weighted imaging without red bone marrow exclusion. Prostate-specific antigen progression-free survival, time-to-pain progression, and overall survival were evaluated to assess the prognostic value of the quantified tumor volume.

RESULTS

The quantified tumor volume was significantly smaller than that quantified by the traditional method in metastatic hormone-sensitive (median: 81.0 ml vs. 149.4 ml) and metastatic castration-resistant (median: 29.4 ml vs. 63.5 ml) prostate cancer. A highly quantified tumor volume was associated with prostate-specific antigen progression-free survival (p = 0.030), time-to-pain progression (p = 0.003), and overall survival (p = 0.005) in patients with metastatic hormone-sensitive prostate cancer and with poor prostate-specific antigen progression-free survival (p = 0.001) and time-to-pain progression (p = 0.005) in patients with metastatic castration-resistant prostate cancer.

CONCLUSIONS

Our imaging method could accurately quantify the tumor volume in patients with metastatic prostate cancer. The quantified tumor volume can be clinically applied as a new prognostic biomarker for metastatic prostate cancer.

Cell migration is impaired in XPA-deficient cells

Xeroderma pigmentosum (XP) is a hereditary disorder characterized by photosensitivity, predisposition to skin cancers, and neurological abnormalities including microcephaly and progressive neurodegeneration. A lack of nucleotide excision repair (NER) in patients with XP can cause hypersensitivity to the sun, leading to skin cancer, whereas the etiology of the neuronal symptoms of XP remains ambiguous. There are various neurological disorders that perturb neuronal migration, causing mislocalization and disorganization of the cortical lamination. Here, we investigated the role of the XP group-A (Xpa) gene in directed cell migration. First, we adopted an in utero electroporation method to transduce shRNA vectors into the murine embryonic cerebral cortex for the in vivo knockdown of Xpa. Xpa-knockdown neurons in the embryonic cerebral cortex showed abnormal cell migration, cell cycle exit, and differentiation. The genotype-phenotype relationship between the lack of XPA and cell migration abnormalities was confirmed using both a scratch assay and time-lapse microscopy in XP-A patient-derived fibroblasts. Unlike healthy cells, these cells showed impairment in overall mobility and the direction of motility. Therefore, abnormal cell migration may explain neural tissue abnormalities in patients with XP-A.

Inhibition of sodium-glucose cotransporter 2 suppresses renal stone formation

BACKGROUND AND AIMS

Nephrolithiasis is a common renal disease with no effective medication. Sodium-glucose cotransporter-2 (SGLT2) inhibitors, an anti-diabetic agent, have diuretic and anti-inflammatory properties and could prevent nephrolithiasis. Here, we investigated the potential of SGLT2 inhibition against nephrolithiasis using large-scale epidemiological data, animal models, and cell culture experiments.

METHODS

This study included the data of diabetic patients (n = 1,538,198) available in the Japanese administrative database and divided them according to SGLT2 inhibitor prescription status. For animal experiments, renal calcium oxalate stones were induced by ethylene glycol in Sprague-Dawley rats, and phlorizin, an SGLT1/2 inhibitor, was used for the treatment. The effects of SGLT2-specific inhibition for renal stone formation were assessed in SGLT2-deficient mice and a human proximal tubular cell line, HK-2.

RESULTS

Nephrolithiasis prevalence in diabetic men was significantly lower in the SGLT2 inhibitor prescription group than in the non-SGLT2 inhibitor prescription group. Phlorizin attenuated renal stone formation and downregulated the kidney injury molecule 1 (Kim1) and osteopontin (Opn) expression in rats, with unchanged water intake and urine volume. It suppressed inflammation and macrophage marker expression, suggesting the role of the SGLT2 inhibitor in reducing inflammation. SGLT2-deficient mice were resistant to glyoxylic acid-induced calcium oxalate stone formation with reduced Opn expression and renal damages. High glucose-induced upregulation of OPN and CD44 and cell surface adhesion of calcium oxalate reduced upon SGLT2-silencing in HK-2 cells.

CONCLUSION

Overall, our findings identified that SGLT2 inhibition prevents renal stone formation and may be a promising therapeutic approach against nephrolithiasis.

Cutting edge technologies expose the temporal regulation of neurogenesis in the Drosophila nervous system

During the development of the central nervous system (CNS), extremely large numbers of neurons are produced in a regular fashion to form precise neural circuits. During this process, neural progenitor cells produce different neurons over time due to their intrinsic gene regulatory mechanisms as well as extrinsic mechanisms. The Drosophila CNS has played an important role in elucidating the temporal mechanisms that control neurogenesis over time. It has been shown that a series of temporal transcription factors are sequentially expressed in neural progenitor cells and regulate the temporal specification of neurons in the embryonic CNS. Additionally, similar mechanisms are found in the developing optic lobe and central brain in the larval CNS. However, it is difficult to elucidate the function of numerous molecules in many different cell types solely by molecular genetic approaches. Recently, omics analysis using single-cell RNA-seq and other methods has been used to study the Drosophila nervous system on a large scale and is making a significant contribution to the understanding of the temporal mechanisms of neurogenesis. In this article, recent findings on the temporal patterning of neurogenesis and the contributions of cutting-edge technologies will be reviewed.

Pazopanib-Induced Liver Injury in Patients With Metastatic Renal Cell Carcinoma: A Report of Two Cases

We report two cases of pazopanib (PAZ)-induced liver injury in patients with metastatic renal cell carcinoma. The first patient was a 70-year-old female who was diagnosed with right renal cell carcinoma and showed tumor embolism in the inferior vena cava. PAZ was started but discontinued after about one month due to a grade four liver injury. The second patient was a 60-year-old male who was diagnosed with left renal cell carcinoma and suspected multiple lung metastases. PAZ was started following a laparoscopic left radical nephrectomy but was stopped after about a month due to a grade three liver injury. We analyzed the plasma PAZ concentrations for treatment evaluation. High plasma PAZ concentrations were observed in both patients after PAZ treatment began. Severe liver injury after PAZ administration may be associated with high plasma PAZ concentrations; hence, we should reduce PAZ dosage early. We also recommend monitoring plasma PAZ concentrations, if possible, so that physicians can either reduce the dosage or discontinue treatment to avoid further liver damage.

Experimental Study on the Application of Cementless Material with Industrial By-Products to Steam-Cured Precast Concrete Products

The purpose of this study was to apply a cementless binder using industrial by-products (fly ash, ground-granulated blast furnace slag, and silica fume) to precast concrete products. In this binder, calcium hydroxide was included as an alkali stimulant but Portland cement was not included. Experiments on the compressive strength and durability of this type of material were conducted and its applicability to precast concrete products was investigated using full-scale specimens. The experiments proved that high-temperature steam curing is effective at obtaining strength development and that compressive strength can be expressed as a linear function of the binder-water ratio. Experimental results of chloride ion diffusion coefficient and sulfuric acid resistance suggested that the proposed material has higher resistances than conventional cement concrete against these deterioration factors. It was also demonstrated that full-scale specimens of a box culvert and a centrifugally compacted pipe using this type of material have almost the same load-bearing capacity and deformation performance as those using conventional cement concrete. It is believed that the proposed material could be used as a construction material instead of cement concrete, contribute to reducing CO₂ emission, and increase the reuse of industrial by-products.

Fezf2-positive fork cell-like neurons in the mouse insular cortex

The fork cell and von Economo neuron, which are found in the insular cortex and/or the anterior cingulate cortex, are defined by their unique morphologies. Their shapes are not pyramidal; the fork cell has two primary apical dendrites and the von Economo neurons are spindle-shaped (bipolar). Presence of such neurons are reported only in the higher animals, especially in human and great ape, indicating that they are specific for most evolved species. Although it is likely that these neurons are involved in higher brain function, lack of results with experimental animals makes further investigation difficult. We here ask whether equivalent neurons exist in the mouse insular cortex. In human, Fezf2 has been reported to be highly expressed in these morphologically distinctive neurons and thus, we examined the detailed morphology of Fezf2-positive neurons in the mouse brain. Although von Economo-like neurons were not identified, Fezf2-positive fork cell-like neurons with two characteristic apical dendrites, were discovered. Examination with electron microscope indicated that these neurons did not embrace capillaries, rather they held another cell. We here term such neurons as holding neurons. We further observed several molecules, including neuromedin B (NMB) and gastrin releasing peptide (GRP) that are known to be localized in the fork cells and/or von Economo cells in human, were localized in the mouse insular cortex. Based on these observations, it is likely that an equivalent of the fork cell is present in the mouse.

Soluble receptor for advanced glycation end products (sRAGE) correlates with obesity-related parameters, and it is not easy to be modified by moderate caloric restriction in obese humans

Deficiency of a soluble form of the advanced glycation end products receptor (sRAGE) is implicated in obesity-induced complications. Serum sRAGE is inclined to be modified by changes in body weight. We analysed serum sRAGE concentrations in patients with obesity undergoing moderate calorie restriction, which mimics the real-life situation and is not harmful to obese humans. Serum sRAGE was measured by immunoassay in 50 patients with obesity who underwent calorie restriction by 300-500 kcal/day for 8 weeks. In effect calorie restriction resulted in an expected decrease in body weight (by 2.1 kg for an 8-week intervention, p<0.0001), as well as reduced systolic blood pressure, modified dyslipidemia (cholesterol, triglycerides), reduced obesity-related inflammation (tumor necrosis factor-alfa, interleukin-6, C-reactive protein), improved insulin sensitivity. However, it was not accompanied by any significant change in sRAGE concentration. There was a strong negative correlation between BMI and the sRAGE level. Accordingly, the levels of sRAGE were the highest in lean control. In conclusion: a modest weight reduction is unlikely to improve decreased sRAGE levels.

Cytoneme-like protrusion formation induced by LAR is promoted by receptor dimerization

Actin-based protrusions called cytonemes are reported to function in cell communication by supporting events such as morphogen gradient establishment and pattern formation. Despite the crucial roles of cytonemes in cell signaling, the molecular mechanism for cytoneme establishment remains elusive. In this study, we showed that the leukocyte common antigen-related (LAR) receptor protein tyrosine phosphatase plays an important role in cytoneme-like protrusion formation. Overexpression of LAR in HEK293T cells induced the formation of actin-based protrusions, some of which exceeded 200 µm in length and displayed a complex morphology with branches. Upon focusing on the regulation of LAR dimerization or clustering and the resulting regulatory effects on LAR phosphatase activity, we found that longer and more branched protrusions were formed when LAR dimerization was artificially induced and when heparan sulfate was applied. Interestingly, although the truncated form of LAR lacking phosphatase-related domains promoted protrusion formation, the phosphatase-inactive forms did not show clear changes, suggesting that LAR dimerization triggers the formation of cytoneme-like protrusions in a phosphatase-independent manner. Our results thus emphasize the importance of LAR and its dimerization in cell signaling.

This article has an associated First Person interview with the first author of the paper.

Summary: We showed that the formation of cytoneme-like protrusions, which function in cell signaling, is induced by LAR and clarified that it is LAR dimerization which promotes protrusion formation.

Updated soil to fruit concentration ratios for radiocaesium compiled under the IAEA MODARIA II Programme

Under the International Atomic Energy Agency (IAEA) Modelling and Data for Radiological Impact Assessments (MODARIA II) Programme, Working Group 4 activities included collating radionuclide transfer data from Japan following the Fukushima Daiichi Nuclear Power Plant accident and separately collating concentration ratio (CR) data for root uptake of radionuclides by crops grown in tropical and arid climates. In this paper, the newly compiled radiocaesium CR data for fruit from Japan, tropical and arid climates have been combined with the data originally compiled for the IAEA Technical Reports Series No. 472 (TRS 472) and additional data identified from the literature to produce an enhanced MODARIA II dataset of fruit radiocaesium CR values. Statistical analysis of the MODARIA II dataset by climate class (based on the Köppen-Geiger climate classification) indicated that the CR values for tropical climates were significantly higher (p< 0.05) than those for arid, temperate and cold climates. Statistical analysis of the MODARIA II dataset by soil group (based on soil texture) indicated that the CR values for coral sand soil (tropical climates only) and organic soil (temperate climates only) were significantly higher (p< 0.05) than those for the clay, loam and sand soil groups. Statistical analysis of the MODARIA II dataset by plant group (based on plant morphology) indicated that the CR values for non-woody trees (tropical climate bias) were significantly higher (p< 0.05) than those for herbaceous plants, shrubs and woody trees. Comparison of the MODARIA II dataset with original TRS 472 values showed only small changes in the fruit radiocaesium CR values for herbaceous plants and shrubs in temperate climates. There was a decrease in the CR values for woody trees in temperate climate across all soil groups. There was also a decrease in the CR values for tropical climates for all comparable soil groups.

Survey of Areas Underserved by Plastic Surgery in Japan

Background  In Japan, there is a large regional disparity in plastic surgery availability. In order for plastic surgery to be widely available for all citizens, it is essential for at least one plastic surgery facility to be located in each secondary medical zone.

Methods  Using the Japan Society of Plastic and Reconstructive Surgery homepage and some databases, we extracted data on secondary medical zones that do not have a plastic surgery facility. The national and regional coverage rates were calculated. The coverage rate for each group divided by the degree of population concentration was also calculated.

Results  We found that 147 of 344 secondary medical zones did not have a plastic surgery facility, and the area coverage rate was found to be 57.27% nationwide. The coverage rate in terms of population was 87.07% (correlation coefficient of area and population coverage = 0.983). The area coverage rates in Hokkaido-Tohoku, Kanto, Chubu, Kansai, Chugoku-Shikoku, and Kyushu-Okinawa districts were 47.46, 72.15, 76.47, 62.79, 52.08, and 32.81%, respectively. The corresponding population coverage rates were 79.92, 91.62, 94.27, 90.59, 80.68, and 69.54%, respectively. The area coverage rates in metropolitan areas, provincial cities, and rural areas were 98.08, 75.90, and 15.87%, respectively. In contrast, the area coverage rate of dermatology was 62.79% and that of orthopaedics was 97.09%.

Conclusion  Unfortunately, it is estimated that more than 40% of secondary medical zones are underserved by plastic surgery, and 13% of the population is not able to fully benefit from this specialty in Japan.

Tiling mechanisms of the Drosophila compound eye through geometrical tessellation

Tiling patterns are observed in many biological structures. The compound eye is an interesting example of tiling and is often constructed by hexagonal arrays of ommatidia, the optical unit of the compound eye. Hexagonal tiling may be common due to mechanical restrictions such as structural robustness, minimal boundary length, and space-filling efficiency. However, some insects exhibit tetragonal facets.^1-4 Some aquatic crustaceans, such as shrimp and lobsters, have evolved with tetragonal facets.^5-8 Mantis shrimp is an insightful example as its compound eye has a tetragonal midband region sandwiched between hexagonal hemispheres.^9,10 This casts doubt on the naive explanation that hexagonal tiles recur in nature because of their mechanical stability. Similarly, tetragonal tiling patterns are also observed in some Drosophila small-eye mutants, whereas the wild-type eyes are hexagonal, suggesting that the ommatidial tiling is not simply explained by such mechanical restrictions. If so, how are the hexagonal and tetragonal patterns controlled during development? Here, we demonstrate that geometrical tessellation determines the ommatidial tiling patterns. In small-eye mutants, the hexagonal pattern is transformed into a tetragonal pattern as the relative positions of neighboring ommatidia are stretched along the dorsal-ventral axis. We propose that the regular distribution of ommatidia and their uniform growth collectively play an essential role in the establishment of tetragonal and hexagonal tiling patterns in compound eyes.

Measurements of Strong-Interaction Effects in Kaonic-Helium Isotopes at Sub-eV Precision with X-Ray Microcalorimeters

We have measured the 3d→2p transition x rays of kaonic ^{3}He and ^{4}He atoms using superconducting transition-edge-sensor microcalorimeters with an energy resolution better than 6 eV (FWHM). We determined the energies to be 6224.5±0.4(stat)±0.2(syst)  eV and 6463.7±0.3(stat)±0.1(syst)  eV, and widths to be 2.5±1.0(stat)±0.4(syst)  eV and 1.0±0.6(stat)±0.3(stat)  eV, for kaonic ^{3}He and ^{4}He, respectively. These values are nearly 10 times more precise than in previous measurements. Our results exclude the large strong-interaction shifts and widths that are suggested by a coupled-channel approach and agree with calculations based on optical-potential models.

Experimental investigation of supertransmission for an intrinsic localized mode in a cyclic nonlinear transmission line

In this experimental study of the nonlinear loss mechanism between traveling localized excitation and the underlying extended normal mode spectrum for a 1D lattice, three types of cyclic, electric, nonlinear transmission lines (NLTLs) are used. They are nonlinear capacitive, inductive, and capacitive+inductive NLTLs. To maintain a robust, steady-state traveling intrinsic localized mode (ILM), a traveling wave driver is used. The ILM loses energy because of a resonance between it and the extended NLTL modes. A wake field excitation is detected directly from ILM velocity experiments by the decrease in ILM speed and by the observation of the wake. Its properties are quantified via a two-dimensional Fourier map in the frequency-wavenumber domain, determined from the measured spatial-time voltage pattern. Simulations support and extend these experimental findings. We find for the capacitive+inductive NLTL configuration, when the two nonlinear terms are theoretically balanced, the wake excitation is calculated to become very small, giving rise to supertransmission over an extended driving frequency range.

Importance of considering interest in sex when evaluating satisfaction after robot-assisted radical prostatectomy

OBJECTIVES

To assess the impact of patients' interest in sex on the satisfaction after robot-assisted radical prostatectomy, longitudinal changes of urinary and sexual functions and bothers were evaluated.

METHODS

A total of 101 patients underwent robot-assisted radical prostatectomy in our institution. Based on sexual interest, they were divided into the high-interest and low-interest groups. Overall satisfaction, urinary function, urinary bother, sexual function, and sexual bother were evaluated using the expanded prostate cancer index composite questionnaire preoperatively and at 1, 3, 6, and 12 months after robot-assisted radical prostatectomy. We investigated the associations between the overall satisfaction and urinary function/urinary bother/sexual function/sexual bother scores (with higher score indicating better function and less impairment).

RESULTS

In the high-interest group (n = 45), satisfaction correlated with high urinary function and urinary bother scores early after robot-assisted radical prostatectomy (urinary function: 1 and 3 months, urinary bother: 3 months postoperatively; P < 0.05) and then with high sexual bother score thereafter (sexual bother at 6 and 12 months after surgery; P < 0.05). Sexual function score did not correlate with satisfaction. In the low-interest group (n = 56), satisfaction correlated with high urinary function and urinary bother scores over time (urinary function: 3 and 6 months, urinary bother: at 3, 6 and 12 months postoperatively; P < 0.05). Neither sexual function nor sexual bother correlated with satisfaction postoperatively in the low-interest group.

CONCLUSIONS

The impact of urinary and sexual functions and bothers on patients' overall satisfaction differed between patients with high- and low-interest in sex. The patient's interest in sex should be considered when assessing satisfaction after robot-assisted radical prostatectomy.

Utility of the Berlin Initiative Study-1 equation for the prediction of serum vancomycin concentration in elderly patients aged 75 years and older

Accurate assessment of renal function is essential for determining serum vancomycin (VCM) concentration. Creatinine clearance (Ccr)-calculated using the Cockcroft and Gault (CG) equation-can be used to evaluate renal function for determining VCM dosage. However, Ccr-based evaluation may not be an accurate representation of the renal function in the elderly. Herein, we examine the effectiveness of estimated glomerular filtration rate (eGFR) calculated using the Berlin Initiative Study-1 (BIS1) equation, for predicting the serum VCM concentration. Herein, we retrospectively analyzed patients (aged ≥ 75 years) who had received VCM. Serum VCM concentration was predicted based on Ccr and eGFR. eGFR was calculated using the Japanese equation for eGFR (eGFR_JAP), Modification of Diet in Renal Disease (MDRD) equation (eGFR_MDRD), chronic kidney disease epidemiology collaboration (CKD-EPI) equation (eGFR_CKD-EPI), and BIS1 equation (eGFR_BIS1). The predicted serum VCM concentration was compared with the measured values. Prediction bias, accuracy, and precision were evaluated by calculating the mean prediction error (ME), mean absolute prediction error (MAE), and root mean squared prediction error (RMSE). Our results showed that the ME between the measured and the predicted values calculated using Ccr and each eGFR was the largest and smallest when calculated based on Ccr and eGFR_MDRD, respectively. MAE and RMSE were the largest and smallest when calculated based on Ccr and eGFR_BIS1, respectively. A significant difference was observed in the MAE associated with eGFR_JAP, eGFR_MDRD, and eGFR_CKD-EPI compared to that associated with eGFR_BIS1. In conclusion, our results suggest that the BIS1 equation might be useful for determining the VCM dosage in the elderly.

Preclinical safety profile of a liver-localized mitochondrial uncoupler: OPC-163493

Mitochondrial uncouplers (mUncouplers) are known to exhibit a variety of toxic effects in animals. Here we report a safety profile of an mUncoupler, OPC-163493, recently synthesized at Otsuka Pharmaceutical Co, Ltd, and its development as a therapeutic agent for treating diabetes. To understand the acute and subchronic toxicity of OPC-163493, single and repeated oral dose studies in rats, dogs, and monkeys were performed. In the rat studies, rigor mortis and increased body temperatures were observed in the high dose group. Focal necrosis, fatty change, and granular eosinophilic cytoplasm of the hepatocytes were also observed in the high dose group. In the dog studies, gastrointestinal manifestations were observed with decreased body weight and decreased food consumption in the high dose group. Necrotizing arteritis was observed in multiple organs as well as meningitis with hemorrhage in the brain. In the monkey studies, vomiting, decreased food consumption, and decreased locomotor activity were observed in the high dose group. Degeneration of the proximal convoluted tubules and the straight tubular epithelium, regeneration of the proximal tubular epithelium, and degeneration of the collecting tubular epithelium were observed. The target organs of OPC-163493 were liver, blood vessels, and kidney in rats, dogs, and monkeys, respectively. In rats, dogs, and monkeys, safety ratios were 100:1, 13:1, and 20:1, respectively, in terms of total exposure (AUC_24h). These safety ratios showed clear separation between exposure to OPC-163493 in animals at NOAEL and the exposure at the effective dose in ZDF rats. This information should contribute to the drug development of new and effective mUncoupler candidates.

Efficacy of one-surgeon basketing technique for stone extraction during flexible ureteroscopy for urolithiasis

Objective: To evaluate the safety and efficacy of using one-surgeon basketing technique by a solo surgeon for stone extraction during flexible ureteroscopy (f-URS) for urolithiasis.

Patients and methods: This retrospective study enrolled patients with urinary calculus who underwent f-URS at two institutions in Japan between September 2014 and March 2020. A total of 100 patients were operated by one experienced surgeon using the one-surgeon basketing technique. With this approach, the f-URS apparatus was manipulated with the non-dominant hand and the basket catheter was manipulated with the dominant hand. We retrospectively examined the perioperative results, complications, and stone-free rate [with ‘stone free’ defined as ≤2 mm with kidney–ureter–bladder (KUB) at 1 month after f-URS] to estimate the safety and efficacy for comparison with the results of conventional retrieval basketing technique.

Results: Among our study population, the median stone size was 14 mm and median operative time was 74 min. A stone-free status was achieved in 91 patients (91%). The median stone fragmentation time was 15 min and stone retrieval time was 30 min. All included patients were treated using the one-surgeon basketing technique. Complications related to stone retrieval were identified in two patients (2%); the degree of ureteral injury was classified as Clavien–Dindo Grade IIIa.

Conclusion: The one-surgeon basketing technique is safe and effective for the extraction of stone fragments during f-URS for urolithiasis. This technique does not require assistance for basketing; therefore, f-URS with active retrieval basketing can be completed by a solo surgeon.

Abbreviations: BMI: body mass index; KUB: kidney–ureter–bladder; SFR: stone-free rate; UAS: ureteral access sheath; f-URS: flexible ureteroscopy