Energy dissipation of a sphere rolling up a granular slope: Slip and deformation of the granular surface

We experimentally investigate the dynamics of a sphere rolling up a granular slope. During the rolling-up motion, the sphere experiences slipping and penetration (groove formation) on the surface of the granular layer. The former relates to the stuck motion of the rolling sphere, and the latter causes energy dissipation due to the deformation of the granular surface. To characterize these phenomena, we measured the motion of a sphere rolling up a granular slope of angle α. The initial velocity v_{0}, initial angular velocity ω_{0}, angle of slope α, and density of the sphere ρ_{s} were varied. As a result, the penetration depth can be scaled solely by the density ratio between the sphere and granular layer. By considering the rotational equation of motion, we estimate the friction due to the slips. Besides, by considering energy conservation, we define and estimate the friction due to groove formation. Moreover, the translational friction is proportional to the penetration depth. Using these results, we can quantitatively predict the sphere's motion including stuck behavior.

Primordial Germ Cell Cryopreservation and Revival of Drosophila Strains

Drosophila strains must be maintained by the frequent transfer of adult flies to new vials. This carries a danger of mutational deterioration and phenotypic changes. Development of an alternative method for long-term preservation without such changes is therefore imperative. Despite previous successful attempts, cryopreservation of Drosophila embryos is still not of practical use because of low reproducibility. Here, we describe a protocol for primordial germ cell (PGC) cryopreservation and strain revival via transplantation of cryopreserved PGCs into agametic Drosophila melanogaster (D. melanogaster) host embryos. PGCs are highly permeable to cryoprotective agents (CPAs), and developmental and morphological variation among strains is less problematic than in embryo cryopreservation. In this method, PGCs are collected from approximately 30 donor embryos, loaded into a needle after CPA treatment, and then cryopreserved in liquid nitrogen. To produce donor-derived gametes, the cryopreserved PGCs in a needle are thawed and then deposited into approximately 15 agametic host embryos. A frequency of at least 15% fertile flies was achieved with this protocol, and the number of progeny per fertile couple was always more than enough to revive the original strain (the average progeny number being 77.2 ± 7.1), indicating the ability of cryopreserved PGCs to become germline stem cells. The average number of fertile flies per needle was 1.1 ± 0.2, and 9 out of 26 needles produced two or more fertile progeny. It was found that 11 needles are enough to produce 6 or more progeny, in which at least one female and one male are likely included. The agametic host makes it possible to revive the strain quickly by simply crossing newly emerged female and male flies. In addition, PGCs have the potential to be used in genetic engineering applications, such as genome editing.

Breaking away from an endemic state of multidrug-resistant Pseudomonas aeruginosa by daily sink disinfection

The detection rate of multidrug-resistant Pseudomonas aeruginosa in patients admitted to 2 wards and the intensive care unit decreased from 20.3% (129 of 636 isolates) to 4.2% (37 of 889 isolates) after the start of disinfection of hand washing sinks using alkyl diaminoethylglycine hydrochloride.

Factors associated with household transmission of SARS-CoV-2 omicron variant to health care workers: A retrospective cohort study

AIM

The aim of this study was to determine the risk factors for household transmission of the omicron variant of SARS-CoV-2.

BACKGROUND

The household infection rate has been reported to be higher for the omicron variant than for non-omicron variants of SARS-CoV-2. Determination of the risk factors for household transmission of the omicron variant is therefore important.

DESIGN

A Retrospective Cohort Study was conducted.

METHODS

When family members of health care workers (HCWs) were found to be infected with SARS-CoV-2, the HCWs had to receive two nucleic acid amplification tests for SARS-CoV-2: immediately after and 5 to 10 days after the onset of COVID-19 in the family members. Risk factors of household transmission were analysed by comparing cases (HCWs infected with SARS-CoV-2) and controls (HCWs not infected with SARS-CoV-2) using multivariable analysis.

RESULTS

Unvaccinated status (OR: 3.97), age of index cases (≤6 years) (OR: 1.94) and staying at home with index cases (OR: 10.18) were risk factors for household transmission.

CONCLUSION

If there is a strong desire to avoid household infection, family members infected with SARS-CoV-2 should live separately during the period of viral shedding.

Segmental Zoster Paresis Accompanied by Horner's Syndrome

We herein report a 90-year-old immunocompromised woman who developed right upper limb weakness and right ptosis with a miotic pupil 1 week after oral therapy for zoster on the right T2 dermatome. The right pupil was dilated with instillation of 1% apraclonidine, indicating Horner's syndrome. The patient was treated with intravenous acyclovir and methylprednisolone. Focal weakness related to zoster, generally known as segmental zoster paresis, improved over five months, but Horner's syndrome remained. We suggest that aggressive intravenous treatment should be considered for rare cases of zoster that occur with a combination of these two neurological conditions.

Correlation between antibiotic use and resistance of gram-negative bacteria at a university hospital in Japan from 2013 to 2021: a study using the Japan Surveillance for Infection Prevention and Healthcare Epidemiology system

OBJECTIVES

The Japan Surveillance for Infection Prevention and Healthcare Epidemiology (J-SIPHE) system aggregates information related to antimicrobial resistance (AMR) measures. We aimed to investigate the correlation between antibiotic use and AMR at a university hospital from 2013 to 2021 in a time series analysis using the J-SIPHE system. We also studied this correlation in each ward (inter-ward analysis).

METHODS

Data on antibiotic use and resistance rates were collected from the J-SIPHE system, except for the resistance rate in each ward, which was calculated from the source data prepared for this system.

RESULTS

Piperacillin/tazobactam use was positively correlated with piperacillin/tazobactam resistance in Escherichia coli and Klebsiella pneumoniae in the inter-ward analysis, and in Pseudomonas aeruginosa in both analyses. Carbapenem use was positively correlated with meropenem resistance in Enterobacter cloacae in the time series analysis and in P. aeruginosa in both analyses, and imipenem/cilastatin resistance in P. aeruginosa in inter-ward analysis. Quinolone use was positively correlated with levofloxacin resistance in E. coli in both analyses, and in K. pneumoniae in inter-ward analysis.

CONCLUSIONS

This is the first study to investigate the correlation between antibiotic use and AMR at a single hospital in time series and inter-ward analyses using the J-SIPHE system and data prepared for this system, suggesting that this system may be useful for promoting AMR measures.

Correlation between antibiotic use and antibiotic resistance: A multicenter study using the Japan Surveillance for Infection Prevention and Healthcare Epidemiology (J-SIPHE) system in Hokkaido, Japan

BACKGROUND

The Japan Surveillance for Infection Prevention and Healthcare Epidemiology (J-SIPHE) system aggregates information related to antimicrobial resistance (AMR) measures in participating medical institutions nationwide and is intended to be used for promotion of AMR measures in participating facilities and their communities. This multicenter study aimed to determine the usefulness of the J-SIPHE system for evaluating the correlation between antibiotic use and antibiotic resistance in Hokkaido, Japan.

METHODS

Data on antibiotic use and detection rate of major resistant Gram-negative bacteria at 19 hospitals in 2020 were collected from the J-SIPHE system, and data correlations were analyzed using JMP Pro.

RESULTS

The detection rate of carbapenem-resistant Pseudomonas aeruginosa was significantly positively correlated with carbapenem use (Spearman's ρ = 0.551; P = .015). There were significant positive correlations between the detection rate of fluoroquinolone-resistant Escherichia coli and the use of piperacillin/tazobactam, carbapenems, and quinolones [ρ = 0.518 (P = .023), ρ = 0.76 (P < .001), and ρ = 0.502 (P = .029), respectively].

CONCLUSIONS

This is the first multicenter study to investigate the correlation between antibiotic use and antibiotic resistance using the J-SIPHE system. The results suggest that using this system may be beneficial for promoting AMR measures.

Clinical outcomes of intervention for carbapenems and anti-methicillin-resistant Staphylococcus aureus antibiotics by an antimicrobial stewardship team

BACKGROUND

There are no reports on the effects of interventions, such as discontinuation and change and/or de-escalation of carbapenems and anti-methicillin-resistant Staphylococcus aureus (MRSA) antibiotics by an antimicrobial stewardship team focusing on detailed patient outcomes. This study aimed to evaluate these effects.

METHODS

This retrospective cohort study was conducted at a tertiary care hospital from December 2018 to November 2019.

RESULTS

Favorable clinical responses were obtained in 165 of 184 cases (89.7%) in the intervention-accepted group, higher than those in the not accepted group (14/19 cases, 73.7%; P = .056). All-cause 30 day mortality was lower in the accepted group than in the not accepted group (1.1% and 10.5%, respectively; P = .045). The microbiological outcomes were similar between the two groups. Duration of carbapenem and anti-MRSA antibiotic use in the accepted group was significantly lower than that in the not accepted group (median [interquartile range]: 8 days [5-13] versus 14 days [8-15], respectively, P = .026 for carbapenem; 10 days [5.3-15] vs 15.5 days [13.8-45.3], respectively, P = .014 for anti-MRSA antibiotic).

CONCLUSIONS

This is the first study to investigate the effects of interventions such as discontinuation and change and/ or de-escalation of antibiotics on detailed outcomes. Our intervention could reduce the duration of carbapenem and anti-MRSA antibiotic use without worsening clinical and microbiological outcomes.

Offspring production from cryopreserved primordial germ cells in Drosophila

There is an urgent need to cryopreserve Drosophila stocks that have been maintained as living cultures for a long time. Long-term culture increases the risk of accidental loss and of unwanted genetic alteration. Here, we report that cryopreserved primordial germ cells (PGCs) can produce F1 progeny when transplanted into hosts. The cryopreserved donor PGCs could form germline stem cells in host gonads and contributed to continuous offspring production. Furthermore, the ability to produce offspring did not appear to vary with either differences between donor strains or cryopreservation duration. Therefore, we propose that our cryopreservation method is feasible for long-term storage of various Drosophila strains. These results underscore the potential usefulness of our cryopreservation method for backing up living stocks to avoid either accidental loss or genetic alteration.

Asaoka, Sakamaki, Fukumoto et al. present a more viable method of long-term storage of Drosophila fly strains by cryopreservation of primordial germ cells (PGCs) without any drop in viability. The authors show that PGCs from stage 5 embryos can be transplanted into embryos and properly developed into germline stem cells to produce offspring of both sexes after being revived from storage in liquid nitrogen.

"Burnt-out" progressive multifocal leukoencephalopathy in idiopathic CD4+ lymphocytopenia

Progressive multifocal leukoencephalopathy (PML) is a fatal disease caused by John Cunningham virus (JCV) infection; however, a growing number of PML patients now survive longer and achieve remission, largely due to the advent of combination antiretroviral therapy. Several reports have suggested that the pathology in such patients presents only chronic demyelination without characteristic cellular changes, being referred to as "burnt-out" PML. On the other hand, our knowledge of "burnt-out" PML is still substantially limited, especially in patients with non-human immunodeficiency virus infection. Here, we report a case of PML associated with idiopathic CD4⁺ lymphocytopenia (ICL) who presented with spontaneous remission and survived for 11 years after onset. Notably, postmortem examination revealed surprisingly broad "burnt-out" lesions lacking the classic histopathological findings. However, pathogenic JCV-specific DNA sequences was still present in the autopsied brain tissue. This case suggests that complete remission can be achieved with a persistent presence of JCV-specific pathogenic sequences, even after a catastrophic infection. Considering that there have been a few reported cases of PML with ICL with long survival, the long-term survival of our case may share a favorable immunological response that is unique to a subgroup of ICL.

A novel COL4A1 variant associated with recurrent epistaxis and glioblastoma

COL4A1-related disorders are characterized by a higher incidence of cerebral hemorrhage than other hereditary cerebral small vessel diseases. Accumulating data have shown broad phenotypic variations, and extracerebral hemorrhages have been linked to these disorders. Moreover, the coexistence of neural tumors has been described. Here, we report a Japanese family with a novel COL4A1 variant, including a patient with recurrent epistaxis and glioblastoma.

Utility of phrenic nerve ultrasound in amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder affecting the upper and lower motor neurons causing progressive weakness. It eventually involves the diaphragm which leads to respiratory paralysis and subsequently death. Phrenic nerve (PN) conduction studies and diaphragm ultrasound has been studied and correlated with pulmonary function tests in ALS patients. However, PN ultrasonography has not been employed in ALS. This study aims to sonographically evaluate the morphologic appearance of the PN of ALS patients. Thirty-eight ALS patients and 28 normal controls referred to the neurophysiology laboratory of two institutions were retrospectively included in the study. Baseline demographic and clinical variables such as disease duration, ALS Functional Rating Scale-Revised score, and ALS region of onset were collected. Ultrasound was used to evaluate the PN cross-sectional area (CSA) of ALS and control subjects. The mean PN CSA of ALS patients were 1.08 ± 0.39 mm on the right and 1.02 ± 0.34 mm on the left. The PN CSA of ALS patients were significantly decreased compared to controls (p value < 0.00001). The PN CSA of ALS patients was not correlated to any of the demographic and clinical parameters tested. This study demonstrates that ALS patients have a smaller PN size compared to controls using ultrasonography.

Efficacy and safety of colistin for the treatment of infections caused by multidrug-resistant gram-negative bacilli

BACKGROUND

The efficacy and safety of colistin for the treatment of infections caused by multidrug-resistant gram-negative bacilli have been poorly investigated in Japanese patients. This study was performed to investigate the efficacy and safety of colistin in Japanese patients by analyzing a considerable number of cases. Furthermore, we evaluated the relationship between the plasma concentration and efficacy and safety of colistin in some cases.

METHODS

A retrospective cohort study was conducted at Hokkaido University Hospital, analyzing patients treated with colistin (colistimethate sodium) during the period from January 2007 to December 2019.

RESULTS

Overall, 42 cases were enrolled. Favorable clinical response was observed in 25 cases (59.5%), with an all-cause 30-day mortality of 33.3% (14/42 cases). Microbiological eradication was achieved in 18 cases (42.9%). Nephrotoxicity was observed in 20 cases (47.6%) and was mild and reversible in all cases. Plasma trough concentrations of colistin determined in nine patients correlated with changes in serum creatinine concentration (⊿) and creatinine clearance (%). The cutoff value of colistin trough concentration for nephrotoxicity was 2.02 μg/mL.

CONCLUSION

Our results showed approximately 60% clinical efficacy of colistin therapy against infections caused by multidrug-resistant gram-negative bacilli in the patients. Further studies with larger populations are needed to elucidate the efficacy and safety of colistin in Japanese patients.

Coexistence of osteoporosis and atherosclerosis in pheochromocytoma: new insights into its long-term management

Osteoporosis and atherosclerosis frequently coexist in patients with pheochromocytoma. The presence of osteoporosis may predict that of atherosclerosis and vice versa in patients with PHEO. These findings have implications for the long-term management of the pheochromocytoma and its potential chronic complications.

INTRODUCTION

Pheochromocytoma (PHEO), a catecholamine-producing tumor, is often found incidentally, and it may be present for years before it is diagnosed. However, long-term exposure to catecholamines excess may induce chronic complications, such as osteoporosis and atherosclerosis. We aimed to evaluate concomitant osteoporosis and atherosclerosis in patients with PHEO.

METHODS

Fifty-one patients with PHEO and 51 patients with a non-functional adrenal tumor were compared radiographically for the prevalence of vertebral fracture (VF), a typical osteoporotic fracture, and abdominal aortic calcification (AAC).

RESULTS

In patients with PHEO, the prevalence of AAC was higher in those with VF (58%) than in those without (6%, p < 0.001). AAC was associated with VF after adjusting for age and sex (odds ratio, 1.53; 95% confidence interval, 1.07-2.46; p = 0.003) in patients with PHEO. The degree of catecholamine excess correlated with the presence of VF and AAC (p = 0.007). The prevalence of VF was higher in patients with PHEO (37%) than those with non-functional AT (12%, p = 0.005), but the prevalence of AAC was comparable between the two groups (25% and 19%, p = 0.636). VF and AAC more frequently coexisted in patients with PHEO (22%) than in those with non-functional AT (2%, p = 0.003).

CONCLUSION

This study represents the first demonstration that osteoporosis and atherosclerosis frequently coexist in patients with PHEO. The presence of osteoporosis may predict that of atherosclerosis and vice versa in patients with PHEO. These findings have implications for the long-term management of the PHEO and its potential chronic complications.

SARS-CoV-2 detection by fluorescence loop-mediated isothermal amplification with and without RNA extraction

Rapid and simple point-of-care detection of SARS-CoV-2 is an urgent need to prevent pandemic. Reverse transcription loop-mediated isothermal amplification (RT-LAMP) can detect SARS-CoV-2 more rapidly than RT-PCR. Saliva is non-invasive specimen suitable for mass-screening, but data comparing utility of nasopharyngeal swab (NPS) and saliva in RT-LAMP test are lacking and it remains unclear whether SARS-CoV-2 could be detected by direct processing of samples without the need for prior RNA extraction saliva. In this study, we compared utility of saliva and NPS samples for the detection of SARS-CoV-2 by a novel RT-fluorescence LAMP (RT-fLAMP). The sensitivity and specificity of the RT-fLAMP with RNA extraction were 97% and 100%, respectively, with equivalent utility of NPS and saliva. However, sensitivity was decreased to 71% and 47% in NPS and saliva samples without RNA extraction, respectively, suggesting that RNA extraction process may be critical for the virus detection by RT-fLAMP.

Pathogenic Effect of Prevotella intermedia on a Mouse Pneumonia Model Due to Methicillin-Resistant Staphylococcus aureus With Up-Regulated α-Hemolysin Expression

Background: Methicillin-resistant Staphylococcus aureus (MRSA) is a common causative agent of pneumonia; however, the detailed mechanism underlying severe MRSA pneumonia, including association with oral hygiene or periodontitis, remains poorly characterized. In this study, we examined the pathogenic effect of Prevotella intermedia, a major periodontopathic pathogen, on MRSA pneumonia.

Methods: The pathogenic effect of the supernatant of P. intermedia (Pi Sup) was investigated in a murine MRSA pneumonia model, using several clinical strains; whereas the bactericidal activity of polymorphonuclear leukocytes (PMNs) was investigated in vitro. The effect of Pi Sup on messenger RNA (mRNA) expression of the toxin/quorum sensing system (rnaIII) was investigated by quantitative reverse transcription PCR both in vitro and in vivo.

Results: Mice infected by hospital-acquired MRSA (HA-MRSA) with Pi Sup exhibited a significantly lower survival rate, higher bacterial loads in the lungs, and higher α-hemolysin (hla) expression in the lungs, than those without Pi Sup. A similar effect of Pi Sup was not observed with MRSA strains producing Panton-Valentine leucocidin (PVL) or toxic shock syndrome toxin (TSST). In vitro, Pi Sup suppressed bactericidal activity of PMNs against the HA-MRSA strain. HA-MRSA was the clinical strain with the highest ability to proliferate in the lungs and was accompanied by time-dependent up-regulation of rnaIII and hla.

Conclusions: Our results provide novel evidence that the product of P. intermedia exerts a pathogenic effect on MRSA pneumonia, in particular with a strain exhibiting strong proliferation in the lower airway tract. Moreover, our results indicate that P. intermedia affects MRSA toxin expression via quorum sensing in a strain-dependent fashion, which might be important for understanding the pathogenesis of severe MRSA pneumonia.

Cerebral Venous Thrombosis: An Unexpected Complication with Cerebrospinal Fluid Leaks after a Fall in a Patient with Spinocerebellar Ataxia Type 6

A 65-year-old woman with spinocerebellar ataxia presented with generalized seizures due to subcortical hemorrhaging. Magnetic resonance imaging (MRI) revealed obstruction of the superior sagittal sinus. Despite treatment, she became comatose. MRI newly revealed subdural fluid collection and descent of the brainstem. Her history indicated a recent fall, prompting additional studies, which revealed lumbar fracture and cerebrospinal fluid (CSF) leaks. We performed an epidural blood patch, and her consciousness was fully restored in one month. This is the first report of cerebral venous thrombosis with CSF leaks in the lumbar region due to a fall injury.