ARGONAUTE1-binding Tudor domain proteins function in small interfering RNA production for RNA-directed DNA methylation

Transposable elements (TEs) contribute to plant evolution, development, and adaptation to environmental changes, but the regulatory mechanisms are largely unknown. RNA-directed DNA methylation (RdDM) is one TE regulatory mechanism in plants. Here, we identified that novel ARGONAUTE 1 (AGO1)-binding Tudor domain proteins Precocious dissociation of sisters C/E (PDS5C/E) are involved in 24-nt siRNA production to establish RdDM on TEs in Arabidopsis thaliana PDS5 family proteins are subunits of the eukaryote-conserved cohesin complex. However, the double mutant lacking angiosperm-specific subfamily PDS5C and PDS5E (pds5c/e) exhibited different developmental phenotypes and transcriptome compared with those of the double mutant lacking eukaryote-conserved subfamily PDS5A and PDS5B (pds5a/b), suggesting that the angiosperm-specific PDS5C/E subfamily has a unique function in angiosperm plants. Proteome and imaging analyses revealed that PDS5C/E interact with AGO1. The pds5c/e double mutant had defects in 24-nt siRNA accumulation and CHH DNA methylation on TEs. In addition, some lncRNAs that accumulated in the pds5c/e mutant were targeted by AGO1-loading 21-nt miRNAs and 21-nt siRNAs. These results indicate that PDS5C/E and AGO1 participate in 24-nt siRNA production for RdDM in the cytoplasm. These findings indicate that angiosperm plants evolved a new regulator, the PDS5C/E subfamily, to control the increase in TEs during angiosperm evolution.

Patients with keratinization disorders due to ABCA12 variants showing pityriasis rubra pilaris phenotypes

Pathogenic variants in ABCA12 are important causative genetic defects for autosomal recessive congenital ichthyoses (ARCI), which include congenital ichthyosiform erythroderma (CIE), harlequin ichthyosis, and lamellar ichthyosis. In addition, pathogenic variants in ABCA12 are known to cause a localized nevoid form of CIE due to recessive mosaicism. We previously reported siblings who carried an ABCA12 variant but did not show a "congenital" phenotype. They were considered to have pityriasis rubra pilaris (PRP). Here, we present a further patient with ABCA12 variants whose phenotype was not congenital ichthyosis, in an independent family. Notably, these three patients had geographic unaffected areas. Such areas are not usually found in patients with ARCI who have ABCA12 variants, suggesting mild phenotypes for these patients. Interestingly, the histological features of the ichthyotic lesions in these patients resembled those of PRP. All three patients had homozygous pathogenic missense variants in ABCA12. Our findings expand the phenotypic spectrum of patients with ABCA12 variants.

Mosaicism for ATP2A2 Mutation and Mutant Allelic Fractions Detected by Droplet Digital PCR in Simple Segmental Darier Disease

Abstract is missing (Short communication)

Gluteal Compartment Syndrome After Femoral Nail Extraction: A Case Report

Gluteal compartment syndrome is a rare disorder and no definitive treatment has yet been established. Fasciotomy is often the treatment of choice for gluteal compartment syndrome, but there have been only a few cases that have improved with conservative therapy. A 26-year-old male with a body mass index of 40.5 who underwent femoral nail extraction surgery had severe pain in the right buttock and numbness in the right lower extremity. Initially, we suspected transient pain due to prolonged exposure to the same posture, but muscle weakness in the lower extremities and worsening of renal function appeared over time. Orthopedic evaluation revealed physical examination findings and MRI imaging findings consistent with gluteal compartment syndrome. Conservative treatment with temporary dialysis was chosen instead of fasciotomy because of the time required for diagnosis. Dialysis was started on postoperative day 3, renal function and muscle weakness recovered over time, and the patient was discharged home on postoperative day 37. At six months post-op, the patient was walking without pain and he had no changes in his peripheral neurologic examination compared to his preoperative baseline. Orthopedic surgeons should always be aware of the possibility of gluteal compartment syndrome when especially obese patients with prolonged operation times appeal to acute buttock pain. Diagnosis should be made as early as possible to get a good prognosis.

Co-existence of Lumbar Disc Herniation and Posterior Ring Apophyseal Fracture: It Is Not Rare and Computed Tomography Is Useful

Introduction Posterior ring apophyseal fracture (PRAF) is characterized by the separation of bone fragments and sometimes coexists with lumbar disc herniation (LDH). However, how often these conditions coexist and the details of the clinical course remain unclear. Methods We analyzed 200 patients who underwent surgical treatment for LDH at our hospital from January 2016 to December 2020. Among these, we reviewed 21 patients who underwent microendoscopic surgery to treat PRAF. They consisted of 11 male and 10 female patients, ranging in age from 15 to 63 years. The average age was 32.8 months, and the average follow-up period was 39.8 years. We performed simple roentgenography and magnetic resonance imaging for all patients and computed tomography for about 80% of the patients. We evaluated the type of PRAF fragment (Takata classification), disease level, Japanese Orthopedic Association (JOA) score, Roland-Morris Disability Questionnaire (RDQ) score, operating time, intraoperative blood loss, and perioperative complications. Results A total of 10.5% of patients with LDH also had PRAF. The mean JOA score significantly improved from 10.6 ± 5.7 points before surgery to 21.4 ± 5.1 points at the final observation (p < 0.05). The mean RDQ score significantly improved from 17.1 ± 4.5 preoperatively to 5.5 ± 0.5 at the final observation (p < 0.05). The average operation time was 88.6 minutes. There were no complications requiring early surgery that were due to postoperative infection or epidural hematoma, but one patient required reoperation. Conclusion This study showed that PRAF coexisted with LDH in about 10% of cases, and the outcomes of surgical treatment were generally good. Computed tomography is recommended to improve the diagnostic rate and assist with surgical planning and intraoperative decision-making.

Anti-desmoglein 1 antibody-positive mother and antibody-negative child with Darier's disease

We report a mother and an adult son with Darier's disease. The mother, 76 years old and Japanese, had positivity for anti-desmoglein (Dsg)1 antibodies. She had erythema with hyperkeratosis and seborrheic and interstitial blistering. A high level of anti-Dsg1 antibodies was detected in the serum. Histopathological examination showed acantholysis and direct immunofluorescence testing revealed intercellular IgG and C3 deposition of the epidermis. Although she was diagnosed as having pemphigus foliaceus, the skin lesions slightly improved with immunosuppressive therapy. Her son, 47 years old, had similar skin lesions on the seborrheic and interstitial parts, but the anti-Dsg1 antibodies were negative in his serum. Histopathological examination showed acantholysis and dyskeratotic cells. Although Hailey-Hailey disease was first suspected, no mutation in the ATP2C1 was detected in either patient. Trio-exome analysis including the father showed a heterozygous c.2027C>A transition on exon 14 of ATP2A2, causing a replacement at amino acid 676 (p.Ala676Asp) in the mother and son only. The two patients were then diagnosed as having Darier's disease. Exome analysis further showed that a novel heterozygous missense mutation of DSG1 was identified only in the affected mother. Anti-Dsg1 antibody-positive Darier's disease is reported here for the first time. Very rare coexistence of Darier's disease and anti-Dsg1 antibody-positivity might be associated with this novel heterozygous DSG1 mutation. Experimental evidence is required to validate this hypothesis.

Bisphosphonates Prescription for Patients With Hip Fractures Based on Evaluation by a Dentist

Background The purpose of this study is to clarify the current status of the prescription of postoperative bisphosphonates for patients with hip fractures and to explore the factors that prevent the postoperative prescription of bisphosphonates. Methods Of 180 patients with hip fractures treated surgically at our hospital between August 2019 and April 2020, 149 patients (46 men and 103 women; mean age: 83.9 ± 9.0 years), excluding 31 patients already prescribed bisphosphonates or denosumab, were included in the study. All patients were treated based on our clinical pathway, and their risk of jaw osteonecrosis was evaluated prior to the initiation of bisphosphonates by a dentist in our hospital. We collected data from the medical records on osteoporosis treatment interventions at admission and discharge, the reasons why postoperative bisphosphonates could not be prescribed at discharge, the proportion of patients who had follow-ups at our hospital, and patients' osteoporosis treatment status. Results Eighteen (12.8%) and 95 (63.8%) patients were prescribed anti-osteoporosis drugs at admission and discharge, respectively. One hundred and twenty-one patients (86.8%) could not be prescribed postoperative bisphosphonates at discharge - 71 (58.7%) because of oral hygiene problems, 34 (28.1%) because they did not have regular dental consultations, seven (5.8%) because of renal dysfunction, eight (6.6%) because of poor cognitive and swallowing function, and one (0.8%) because of medication side effects. Forty-nine patients (32.9%) went to our hospital for follow-up and 11 were introduced to bisphosphonates or denosumab at follow-up. Conclusions The number of patients with hip fractures who were prescribed postoperative bisphosphonates was low in our study. The oral hygiene problems identified by dentists accounted for responsible for the low prescription rate of postoperative bisphosphonates. Therefore, coordination with dentists may be important to increase the postoperative bisphosphonate prescription.

Efficacy of Corticosteroid Addition to a Periarticular Cocktail Injection to Counteract Nausea and Vomiting After Total Knee Arthroplasty

BACKGROUND

Intraoperative periarticular injection of a "cocktail" of drugs is undertaken commonly in total knee arthroplasty (TKA). The addition of a corticosteroid to the periarticular injection is believed to offer greater pain relief because of its local anti-inflammatory effects, but the prevalence of postoperative nausea and vomiting (PONV) is not known. This retrospective observational study aimed to elucidate the relationship between corticosteroid addition to a periarticular cocktail injection (PCI) and PONV.

MATERIALS AND METHODS

Fifty-nine patients who underwent unilateral TKA for primary osteoarthritis were divided into two groups: corticosteroid and non-corticosteroid. The former had triamcinolone acetonide (40 mg) added to the same PCI. The primary outcome was the prevalence of nausea and vomiting within 48 hours following TKA.

RESULTS

There was no significant difference between the two groups in terms of patient demographics. The overall prevalence of PONV was 16.9%. Fewer patients in the corticosteroid group complained of PONV than in the non-corticosteroid group (6.4% vs. 58.3%; p = 0.012).

CONCLUSIONS

The addition of a corticosteroid to a PCI suppressed PONV. Our results suggested that cocktail injections may have local and systemic effects.

Fission yeast Dis1 is an unconventional TOG/XMAP215 that induces microtubule catastrophe to drive chromosome pulling

The shortening of microtubules attached to kinetochores is the driving force of chromosome movement during cell division. Specific kinesins are believed to shorten microtubules but are dispensable for viability in yeast, implying the existence of additional factors responsible for microtubule shortening. Here, we demonstrate that Dis1, a TOG/XMAP215 ortholog in fission yeast, promotes microtubule shortening to carry chromosomes. Although TOG/XMAP215 orthologs are generally accepted as microtubule polymerases, Dis1 promoted microtubule catastrophe in vitro and in vivo. Notably, microtubule catastrophe was promoted when the tip was attached to kinetochores, as they steadily anchored Dis1 at the kinetochore-microtubule interface. Engineered Dis1 oligomers artificially tethered at a chromosome arm region induced the shortening of microtubules in contact, frequently pulling the chromosome arm towards spindle poles. This effect was not brought by oligomerised Alp14. Thus, unlike Alp14 and other TOG/XMAP215 orthologs, Dis1 plays an unconventional role in promoting microtubule catastrophe, thereby driving chromosome movement.

Prophylactic Intrawound Vancomycin Powder in Minimally Invasive Spine Stabilization May Cause an Acute Inflammatory Response

Introduction

Surgical site infections (SSIs) with methicillin-resistant Staphylococcus aureus are serious complications of spinal instrumentation surgery. Many spine surgeons are concerned that using prophylactic vancomycin powder will lead to certain risks: the development of multidrug-resistant pathogens, anaphylactic reactions, and organ toxicity. Minimally invasive spine stabilization (MISt) is associated with shorter operation times and less blood loss and may therefore require the use of less vancomycin powder, which may reduce these risks. This retrospective comparative study of patients who underwent MISt at a single institution aimed to evaluate the complications (such as allergy, SSIs, and organ toxicity) and the local and serum levels associated with using prophylactic intrawound vancomycin powder compared with IV cefazolin alone.

Methods

Thirty-four patients received intrawound vancomycin powder (1 g) applied during wound closure in minimally invasive posterior lumbar interbody fusion (MIS-PLIF). This group was compared with 133 control patients who did not receive vancomycin. White blood cell counts and C-reactive protein (CRP) levels were measured for both groups on postoperative days (PODs) 1, 3, and 7 and were statistically analyzed. In the vancomycin group, serum vancomycin levels were measured on PODs 1, 3, 7, and 14; drain vancomycin levels and postoperative blood loss were determined on PODs 1 and 2.

Results

The CRP levels on PODs 1 and 3 were significantly higher in the vancomycin group than in the control group (P<0.001, P=0.024). In the vancomycin group, mean drain levels trended downward from 313 μg/mL (POD 1) to 155 μg/mL (POD 2). These levels correlated negatively with drain drainage volume on both days (POD 1: r=-0.48, P=0.015; POD 2: r=-0.47, P=0.019). Mean serum vancomycin levels also trended downward from 2.3 μg/mL (POD 1) to 1.7 μg/mL (POD 14).

Conclusions

Our results unexpectedly demonstrated that the local application of vancomycin powder causes an acute inflammatory response and the long-term detection of low serum vancomycin levels. Less than 1 g of intrawound vancomycin powder may be useful only at high risk of SSI.

Factors Affecting Postoperative Spinal Epidural Hematoma and the Optimal Order of Vertebral Body Decompression in Multivertebral Microendoscopic Laminectomy

Purpose

Symptomatic postoperative spinal epidural hematoma (POSEH) is a complication of spine surgery that occurs infrequently but may cause ongoing serious neurological damage. Due to the narrow entry portal, the risk of hematoma is increased after microendoscopic laminectomy (MEL) compared with conventional open surgery, and the risk might be even higher for multivertebral MEL (m-MEL). The purpose of this study was to clarify the factors affecting the development of POSEH after m-MEL and identify the optimal order for the decompression of vertebral bodies.

Methods

A total of 313 patients who underwent m-MEL from 2016 to 2020 were retrospectively assessed. The cohort comprised 238 patients who underwent two-level MEL, 67 who underwent three-level MEL, and eight who underwent four-level MEL. Symptomatic POSEH was defined as the presence of an epidural hematoma at the surgical site on MRI with symptoms such as lower extremity pain or muscle weakness. We elucidated the incidence of POSEH at each vertebral level and investigated the relationship between POSEH and possible risk factors such as clinical and operative variables.

Results

There were 41 patients in the POSEH group and 272 patients in the non-POSEH group. Seven patients in the POSEH group underwent reoperation. The occurrence of POSEH was related to the number of decompressed vertebral bodies. Patients who underwent L2/3 and L3/4 decompression at the end of the procedure also showed a higher incidence of POSEH at the surgical level.

Conclusion

In patients undergoing m-MEL, treatment of the upper lumbar vertebrae at the end of decompression surgery might be a risk factor for symptomatic POSEH. The incidence of POSEH was particularly increased at L2/3, suggesting that L2/3 decompression should not be performed at last and that careful hemostasis should be applied.

Efficacy of Nerve Root Block for the Treatment of Lumbar Spinal Canal Stenosis in Adults Older Than 80 Years of Age

Background: Patients with advanced lumbar spinal canal stenosis (LCS) often prefer non-operative treatment owing to decreased physiological function and comorbidities. Although the therapeutic value of selective nerve root block (SNRB) for LCS is confirmed, there are few reports of its effectiveness in the elderly. We investigated the efficacy of SNRB for LCS in patients over 80 years of age.

Methods: The subjects were 112 patients aged over 80 years (mean age: 84 years; 45 men and 67 women ) with medication-resistant LCS without cauda equina syndrome who underwent SNRB. Cases with acute-onset lumbar disc herniation were excluded. We retrospectively investigated and compared the presence or absence of surgery, effect of SNRB, number of procedures, duration of disease, and magnetic resonance imaging findings. Patients who could avoid the surgery by SNRB were defined as the effective group. Patients whose symptoms were not relieved by SNRB and who underwent surgery and those whose symptoms were not relieved but who continued conservative treatment were defined as the ineffective group. A total of one to seven SNRBs were performed in both groups, and the same spine surgeon performed the entire procedure from SNRB to surgery.

Results: There were 86 nonoperative patients (69 effective cases) and 26 operative patients; the overall rate of effectiveness was 61% (69/112 patients). The area of the spinal canal at the responsible level was 108.63 mm² in the effective group compared with 77.06 mm² in the ineffective group. This was significantly narrower in the ineffective group (p=0.0094). There was no significant difference in the duration of illness, number of blocks, or hernia complication rate between the groups. No patient experienced severe neuralgia that may have been caused by neuropathy during SNRB.

Discussion: Our outcome showed that more than 60% of older patients with LCS showed symptomatic improvement with SNRB. SNRB can be performed relatively safely in the elderly and appears to be a favorable treatment option for older patients with various risks, such as poor general condition.

Conclusions: Multiple sessions of SNRB may provide older patients with symptomatic improvement and may be an option for treatment.

Dermoscopic furrow ink test of the palmar lesion in loricrin keratoderma

Palmoplantar keratodermas (PPK) comprise a heterogeneous group of keratinization disorders that gradually progress during childhood, resulting in difficulties to establish a diagnosis and to identify a candidate gene for sequencing. Dermoscopic examination with staining of palmoplantar skin using a whiteboard marker, so-called "furrow ink test", could be a useful tool for differentiation between furrow and ridge in understanding the morphological characteristics of PPK. One of the striking features in autosomal dominant loricrin keratoderma (LK) is diffuse PPK with honeycomb pattern. In this study, we performed dermoscopic furrow ink test in a Japanese family of LK with the most frequent mutation c.684dup, p.Ser229Valfs*107 in the loricrin gene. The severe lesion revealed that irregular circular hyperkeratoses were aggregated and normal structures of furrows and ridges were disrupted. To accurately describe the nature of this dermoscopic patterned skin surface, we suggest that the condition could be termed as "irregular cobblestone appearance" rather than "honeycomb pattern". Regular cobblestone appearance to maintain parallel furrow structure was observed in early or mild hyperkeratotic lesions. Eccrine sweat glands that open on the surface of ridges nearly disappeared, resulting in hypohidrosis.

Comparison of Microendoscopic Laminotomy (MEL) Versus Spinous Process-Splitting Laminotomy (SPSL) for Multi Segmental Lumbar Spinal Stenosis

Aims 

This study was aimed to compare the perioperative and postoperative outcomes of patients who underwent posterior decompression for multi-segmental lumbar spinal stenosis by microendoscopic laminotomy (MEL) versus spinous process-splitting laminotomy (SPSL) retrospectively.

Methods

We retrospectively reviewed 73 consecutive patients who underwent two or three levels MEL (n=51) or SPSL (n=22) for lumbar spinal stenosis between 2012 and 2018. The perioperative outcomes were operative time, intraoperative blood loss, length of postoperative hospital stay, complications, and reoperation rate. The postoperative outcomes were evaluated using a visual analog scale (VAS) and the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ) scores at one year postoperatively.

Results

The mean follow-up time was 26.6 months in MEL and 35.6 months in SPSL. The mean operative time was significantly longer in MEL than SPSL (two levels, 183.6 ± 43.2 versus 134.8 ± 26.7 min, respectively; three levels: 241.6 ± 47.8 versus 179.9 ± 28.8 min, respectively). MEL's mean postoperative hospital stay was significantly shorter than SPSL (12.3 ± 5.9 versus 15.5 ± 7.2 days, respectively). There was no significant difference in the mean intraoperative blood loss, complication rate, reoperation rate, and postoperative outcomes between the two groups.

Conclusions

This study suggests that both techniques are effective in treating multi-segmental lumbar spinal stenosis. There was no significant difference between the two procedures in intraoperative blood loss (IBL), complications rate, reoperation rate, or improvement in VAS and Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ) scores. MEL had an advantage in the postoperative hospital stay.

Risk Factors for Incidence of Postoperative Spinal Epidural Hematoma Following Multilevel Microendoscopic Laminectomy

Introduction

Due to the narrow portal of entry, microendoscopic laminectomy (MEL) is associated with a risk of postoperative spinal epidural hematoma (POSEH). This risk might be higher when performing multiple-level (m-) MEL. The purpose of this study is to clarify the incidence rate of POSEH following single-level (s-) and m-MEL by each interlaminar level and identify the risk factors for POSEH following m-MEL.

Methods

A total of 379 patients underwent MEL of the lumbar spine (s-MEL, n=141; m-MEL, n=238). We determined the incidence of POSEH following s-MEL and m-MEL by each interlaminar level. For m-MEL, we clarified the correlation between POSEH and possible risk factors, such as operative findings, the sequence of operated interlaminar levels, and the preoperative cross-sectional dural area (CSA) on magnetic resonance imaging.

Results

The incidence rate at L2/3 was significantly higher than that at L3/4 and L4/5. Patients who underwent L2/3 decompression at the end of the procedure showed a higher incidence of POSEH at the L2/3 level. Preoperative spinal stenosis was associated with POSEH at the L2/3 level, and CSA of 56 mm² was a predictive factor for POSEH. Logistic regression analysis revealed that both were significant risk factors.

Conclusions

In patients undergoing m-MEL, the incidence of POSEH is highest at the L2/3 level, and treatment of the L2/3 level at the end of the procedure and the presence of spinal stenosis are risk factors for POSEH.

Life-long Skin Eruptions along Blaschko's Lines in a 27-year-old Woman: A Quiz

Abstract is missing (Quiz)

Risk factors for excessive postoperative sliding of femoral trochanteric fracture in elderly patients: A retrospective multicenter study

INTRODUCTION

The application of a load on the internal fixation of a trochanteric fracture exerts a moment along the lag screw, causing the proximal bone fragment to slide along the lag screw, allowing contact between the proximal and distal bone fragments, which promotes healing. However, excessive sliding is related to poor postoperative outcomes. We aimed to identify the risk factors for excessive sliding.

MATERIALS AND METHODS

We conducted a multicenter retrospective study including 115 trochanteric fractures sustained through low-energy trauma in 19 male and 96 female patients aged 60 years or older (mean age: 82.9 years) between September 2013 and December 2014. We measured the postoperative sliding distance after osteosynthesis using a sliding hip screw or intramedullary nailing, and classified participants with ≥8 mm of sliding into the excessive sliding group (ESG) and with <8 mm into non-ESG. Finally, we investigated the risk factors of excessive postoperative sliding.

RESULTS

Fifty participants were classified into the ESG and 65 participants into the non-ESG. Female sex (p = 0.0264), an A3 fracture type (p = 0.0003), greater tip-apex distance (p = 0.0250), and poor reduction in either the anteroposterior or lateral radiographic views (p = 0.0156) were identified as risk factors for excessive sliding by multivariate regression analysis.

CONCLUSIONS

Female sex, an unstable fracture type, a greater tip-apex distance, and a poor reduction, in either the anteroposterior or lateral views, are associated with excessive postoperative sliding. Therefore, surgery should aim to achieve good reduction and stabilization from both radiographic views.

Massive Lumbar Disc Herniation Causing Cauda Equina Syndrome That Presents As Bladder and Bowel Dysfunction in the Absence of Lower Extremity Weakness

The purpose of this report is to examine the features of cauda equina syndrome (CES) presenting as bladder and bowel dysfunction in the absence of lower extremity weakness. Between July 2015 and July 2016, we experienced four cases of massive LDH causing CES that presented as bladder and bowel dysfunction in the absence of lower extremity weakness. Herein, we describe the clinical features of these four patients (two males and two females) who were followed for a minimum of two years postoperatively. The mean age at the time of surgery was 46.8 years (range, 37-71 years). The disc herniation lesion was at the L4/5 level in one patient, and the L5/S1 level in three. The mean interval between the onset of CES and complete surgical decompression was 10.5 days (range, 1-18 days). Postoperative outcomes were better than poor in three of four cases, while one case had residual sphincter dysfunction. LDH causing CES is considered an indication for immediate surgical decompression; however, diagnosis of CES is likely to be delayed in atypical cases of CES that present as bladder and bowel dysfunction in the absence of lower extremity weakness. Diagnosis of CES tended to be delayed in cases without lower extremity weakness. Clinicians should recognize even sensory impairment alone of the dominant area supplied by S2-4 is an important diagnostic sign of CES in the early stage.

Changes in a Single Institution's Orthopedic Hospitalization Service in Japan Owing to COVID-19 in 2020

Introduction

The coronavirus disease 2019 (COVID-19) pandemic has had immense impact on people and institutions, including the number of admissions to hospitals for surgery. Our aim in this study was to determine the impact of the pandemic on surgeries in a single institution located in Fukuoka, Japan, between 2019 and 2020.

Methods

We quantified the numbers of surgeries in both years according to three sites of injury (indoor, outdoor, and unknown), 14 disease categories, and 9 primary diseases using patients’ medical records. We also compared the hospital cost per day in each month from March to November in both 2019 and 2020 and compared the change in these costs between the two years.

Results

The number of admissions in 2020 was 1,187 cases vs 1,282 cases in 2019. The average patients’ age was higher in 2020 vs 2019 (69.7 ± 0.5 vs 67.5 ± 0.5 years, respectively; p = 0.004), with no gender differences (2020: 705 women and 482 men; 2019: 716 women and 566 men). We found no significant differences in the number of admissions by month between 2019 and 2020. The percentages of outdoor injuries were significantly lower in 2020 vs 2019 (29.8% vs 37.9%, respectively; p = 0.004), and we found significantly different rates when comparing 2020 and 2019 for degenerative disease (42.6% vs 37.4%; p = 0.007), trauma related to falls (34.4% vs 30.2%; p = 0.02), chronic disease (1.9% vs 3.7%; p = 0.005), and sports injuries (0.8% vs 3.7%; p < 0.0001). The rate of sports-related injury was significantly lower in 2020 (1.6%) than in 2019 (7.7%) (p < 0.0001). The daily hospital charge was $10,517.09 (US dollars) in 2020 vs $11,225.32 in 2019, and the charges in the months of April and June were significantly higher in 2020 vs 2019 (p = 0.003 and p = 0.001, for April and June, respectively). Both the number and rate of upper limb fractures were higher in 2020.

Conclusions

The COVID-19 pandemic is affecting some hospitals’ revenue. Although the charges per day were sufficient in our institution in 2020, compared with 2019, some hospital beds were unused during this phase of the pandemic. Hospitals may increase the revenue by mixing both short-term and long-term patients’ hospital stays effectively.

In vivo and in vitro evidence for the inhibition of homogentisate solanesyltransferase by cyclopyrimorate

BACKGROUND

Cyclopyrimorate is a highly effective bleaching herbicide discovered by Mitsui Chemicals Agro, Inc. The target site was recently reported to be homogentisate solanesyltransferase (HST) in the plastoquinone (PQ) biosynthesis pathway on the basis of the number of intermediates in cyclopyrimorate-treated plants and in vitro HST assays. Here, the target site of cyclopyrimorate was further explored using both in vivo and in vitro experiments.

RESULTS

The cyclopyrimorate-dependent bleaching effect on Arabidopsis thaliana was reversed by decyl PQ, suggesting that this symptom is attributable to the inhibition of PQ biosynthesis. Furthermore, homogentisate (HGA), a substrate of HST, weakly reversed the bleaching effect of cyclopyrimorate in a dose-dependent manner. We expected that the weak reversal by HGA was due to competitive inhibition by cyclopyrimorate or des-morpholinocarbonyl cyclopyrimorate (DMC), a metabolite of cyclopyrimorate in plants that exhibit higher HST-inhibitory activity as compared to cyclopyrimorate. Kinetic analysis was therefore conducted using DMC. DMC inhibited HST competitively with respect to HGA, and was a mixed non-competitive inhibitor with respect to the other substrate, farnesyl diphosphate. Moreover, neither cyclopyrimorate nor DMC inhibited 2-methyl-6-phytyl-1,4-benzoquinone/2-methyl-6-solanesyl-1,4-benzoquinone methyltransferase, which is located downstream of HST in the PQ biosynthesis pathway.

CONCLUSIONS

The target site of cyclopyrimorate and DMC is HST, which is a novel target site for commercial herbicides. © 2019 Society of Chemical Industry.

A Novel Microduplication Spanning Exons 8-16 of ATP2C1 That Was Undetectable by Standard Sanger Sequencing in a Japanese Patient With Hailey-Hailey Disease

Hailey-Hailey disease (HHD) is genetic skin disorder characterized by repeated and exacerbated skin lesions in friction regions. ATP2C1, encoding SPCA1, was demonstrated to be the responsible gene for HHD pathogenesis. However, for some cases, no ATP2C1 mutation could be determined by standard Sanger sequencing, thereby obscuring the cause and diagnosis of HHD. In this study, we investigated the possibility that HHD is caused by complex ATP2C1 defects using multiplex ligation-dependent probe amplification (MLPA) analysis for 10 of 50 cases in our institute without ATP2C1 mutations. In one female Japanese patient and her father, who also show HHD, MLPA followed by polymerase chain reaction (PCR) analyses revealed a novel duplication of exons 8-16 of ATP2C1. The duplication was predicted to add 20,615 base pairs, 882 nt, and 294-amino-acid residues to the genome, mRNA and SPCA1 protein, respectively. By reverse transcriptase-PCR using patient skin RNA, we could confirm that a larger transcript was produced and we found that the abundance of the normal transcript was clearly reduced in the patient. Putative structures of wild-type and duplicated proteins revealed differences in arrangement of SPCA1 domains that may have functional consequences. Strikingly, the phosphorylation and the nucleotide-binding domains were interrupted by insertion of a partial actuator, transmembrane, and phosphorylation domains. The additional 294 amino acids appear to disrupt SPCA1 structure and function, causing HHD. Our study expands the spectrum of genetic defects in HHD and showed that disruption of SPCA1 structure and function by the microduplication caused HHD in the patient and her father.

Refracture of pediatric both-bone diaphyseal forearm fracture following intramedullary fixation with Kirschner wires is likely to occur in the presence of immature radiographic healing

PURPOSE

Refracture of pediatric both-bone diaphyseal forearm fractures (PBDFFs) may occur, even if the fractures are treated with intramedullary nailing. The purpose of this study was to investigate the risk of refracture of PBDFFs treated with intramedullary Kirschner wires (K-wires), which are commonly used in our clinic.

METHODS

The present multicenter retrospective study included 60 consecutive patients with 60 PBDFFs who were treated with intramedullary K-wires at 5 hospitals between 2007 and 2016. The age of the patients at the time of the primary fracture ranged from 2 to 15 years. The characteristics of the primary fractures and treatment course were evaluated.

RESULTS

Refracture occurred in 6 patients (10.0%). Three of the patients were young girls; the other 3 were adolescent boys. Refractures were caused by falling or during sports activity. The duration from primary fracture to refracture ranged from 46 to 277 days, and in 5 of the 6 patients refractures occurred within 6 months. Although we were unable to identify factors significantly contributing to refracture (e.g. fracture type or treatment procedures), radiographs at the latest visit before refracture demonstrated findings of immature healing in five of six patients. Both K-wires and external immobilization had been removed before complete fracture healing in a large proportion of patients with refracture (80.0%).

CONCLUSIONS

Refracture of PBDFF may occur several months after treatment with intramedullary K-wires if the primary fracture shows immature healing. Physicians should pay special attention when judging radiographic fracture healing, even when the fracture is deemed to have clinically healed.

P3536Prevalence and clinical impact of social frailty in elderly patients hospitalized for acute decompensated heart failure: a multicenter prospective cohort study

Purpose

The aim of this study was to investigate clinical characteristics of socially frail patients and an association with social frailty and short-term rehospitalization for worsening heart failure.

Methods

We analyzed 169 elderly patients (≥65 years old) hospitalized for acute decompensated heart failure (ADHF) between June 2017 and August 2018 in our prospective HF registry in Japan. The patients with activities of daily living dependence and without data of social frailty and outcome were excluded. Social frailty was determined based on their responses to the 5 questions (living alone, eating alone, going out less frequently, rarely visiting friends, not helpful to friends or family). Patients with none of these components were considered social non-frailty; those with one component were considered social prefrailty; those with two or more components were considered social frailty. The outcome was rehospitalization for worsening HF within 6 months after discharge.

Results

The mean age was 79±8 years old. Social frailty in 86 patients (50.8%), social prefrailty in 41 patients (24.3%), and social non-frailty in 42 patients (24.9%) were observed. Age, body mass index, geriatrics nutritional risk index, Hasegawa dementia rating scale-revised score, gait speed, and handgrip strength values were significantly different among the these three groups (all Ps for trend <0.01). Left ventricular ejection fraction, brain natriuretic peptide values, and the proportion of the patients with the symptom of New York Heart Association class III/IV did not vary significantly between the groups. Kaplan-Meier analysis revealed that higher prevalence of rehospitalization for worsening HF within 6 months in the social frailty group compared to that in the social non-frailty group (Log-rank p<0.05). In a Cox proportional hazard model after adjusting covariates, patients with social frailty (hazard ratio 4.77; 95% CI 1.61–14.12, p<0.005) and social prefrailty (hazard ratio 3.73; 95% CI 1.12–12.41, p<0.05) had an increased risk of rehospitalization for worsening HF within 6 months compared with those with social non-frailty.

Conclusion

This study revealed that social frailty was common in elderly patients hospitalized for ADHF, and social frailty was an independent predictor of rehospitalization for worsening HF within 6 months after discharge.

Anatomical Evaluation of Lumbar Arteries for Lateral Lumbar Interbody Fusion with Magnetic Resonance Imaging

Introduction

Lateral lumbar interbody fusion (LLIF) is becoming a more common surgical treatment option for adult degenerative lumbar conditions. LLIF is a mini-open access technique with wound retractors, and postoperative hematoma due to segmental vessels injury is reported. Thus, it is considered that there is a need to conduct detailed preoperative examinations to identify where the lumbar vessels are. As far as we know, there are only a few studies investigating the location of the lumbar arteries. This study evaluates the anatomical position of lumbar arteries using magnetic resonance imaging (MRI).

Methods

We studied 101 MRIs of patients with lumbar disease. The length from the upper and lower end plates of the vertebra to the lumbar arteries was measured. The measurement was conducted with coronal MRI images of every quarter slice of L1 to L4 vertebrae. We also investigated sagittal MRI images to determine whether the lumbar vessels are located on intervertebral disc in each level from L1/2 to L5/S1.

Results

The lumbar vessels are not always located at the center of the vertebrae. Some lumbar vessels are located within 8 mm from the end plates. Especially in L4, the lumbar vessels tended to go down from the anterior cranial side to the posterior caudal side (P < 0.01). 8, 24, and 54 lumbar vessels are located at the anterior quarter, the center, and the posterior quarter slice of the vertebrae, respectively, in L4. There were seven lumbar vessels in total located on the vertebral disc level.

Conclusions

It is necessary to investigate where the lumbar arteries are located to prevent its injury in LLIF, because the lumbar artery is not always located at the center of a vertebra. MRIs may provide a valuable information to avoid vascular injury during LLIF.

An Early Arising Role of the MicroRNA156/529-SPL Module in Reproductive Development Revealed by the Liverwort Marchantia polymorpha

In angiosperms, the phase transition from vegetative to reproductive growth involves the de-repression of the squamosa promoter-binding-protein-like (SPL) class of transcription factors, which is negatively regulated by the specific microRNAs (miRNAs/miRs) miR156/529 [1]. Non-vascular land plants also undergo growth-phase transition to the reproductive state, but knowledge regarding the controlling mechanisms is limited. Here, we investigate the reproductive transition in the liverwort Marchantia polymorpha, focusing on the roles of miR529c [2-4] and MpSPL2. First, we established mir529c-null mutants using CRISPR/Cas9. Even in the absence of far-red light-supplemented long-day condition, which is usually needed to induce reproductive development [5, 6], the mutant thalli developed sexual reproductive organs (gametangia) and produced gametes. Transgenic plants expressing a miR529-resistant MpSPL2 transgene also showed a similar phenotype of reproductive transition in the absence of inductive far-red light signals. In these mutants and transgenic plants, the MpSPL2 mRNA abundance was elevated. Mpspl2^ko mutant plants showed successful gamete development and fertilization, which suggests that MpSPL2 is involved in, but not essential for, sexual reproduction in M. polymorpha. Furthermore, analysis of Mpspl2^ko mutant and its complemented lines suggests that MpSPL2 may have a role in promotion of reproductive transition. These findings support the notion that the transition to reproductive development in liverworts is controlled by a system similar to that in angiosperms, and the miR156/529-SPL module has common significance in the control of the vegetative-to-reproductive transition during development in many land plants, including liverworts.

Development of a novel fungicide, tolprocarb

Tolprocarb developed by Mitsui Chemicals Agro, Inc. (Tokyo, Japan) was discovered as a new oomycete fungicide. However, its antifungal spectrum and action mechanisms against fungi are completely different from those of the original compound, iprovalicarb. Tolprocarb has a potent and highly controlled effect on a rice blast fungus Magnaporthe grisea, and its mode of action was revealed to be the inhibition of polyketide synthase in the melanin biosynthesis pathway. In addition, tolprocarb induced systemic acquired resistance in Arabidopsis thaliana and rice (Oryza sativa L.). Owing to these double modes of action, tolprocarb can effectively control not only rice blast but also bacterial diseases, and has a low risk of developing fungicide-resistant isolates. Tolprocarb also provides long-term residual activity. A meta-analysis was performed in order to demonstrate tolprocarb's superior control against panicle blast in paddy fields. In addition, tolprocarb did not show cross-resistance against the fungi that are resistant to dehydratase inhibitor in melanin biosynthesis (Melanin Biosynthesis Inhibitor-Dehydratase; MBI-D) or respiratory complex III: cytochrome bc ₁ at Quinone outside site inhibitor (Quinone outside Inhibitor; QoI). Owing to its stable effects, tolprocarb appears to be a suitable choice for practical use against fungi in the rice production field.

Subjective Evaluation of Denture Adhesives: A Multicenter Randomized Controlled Trial

INTRODUCTION

Many reports show that denture adhesives improve the retention and stability of dentures. However, few randomized controlled trials have examined the effects of denture adhesives.

OBJECTIVE

This 10-center randomized controlled trial with parallel groups involving 200 edentulous patients wearing complete dentures aimed to evaluate the effects of short-term use of cream and powder denture adhesives.

METHODS

Patients were allocated into 2 cream- and powder-type adhesive groups and 1 control group. Intervention groups were treated with the 2 adhesives (1 each), and the control group received saline solution. Adhesive or control was applied to the denture-mucosal surface for 4 d, and data at baseline and after day 4 of intervention (i.e., 8 meals) were obtained. Patient satisfaction was evaluated with a 100-mm visual analog scale. Oral health-related quality of life was measured with the Japanese version of the Oral Health Impact Profile for Edentulous Patients. Perceived chewing ability was evaluated by a questionnaire regarding ease of chewing and swallowing food. Between-group comparisons were performed with Kruskal-Wallis tests with the Mann-Whitney U test adjusted by Bonferroni correction. Within-group comparisons of pre- and postintervention measurements were performed with the Wilcoxon signed-rank test. Intention-to-treat analysis was also performed.

RESULTS

Between-group comparisons showed no significant differences for general satisfaction or Oral Health Impact Profile for Edentulous Patients. However, significant differences in satisfaction with various denture functions with cream- and powder-type adhesives were seen in pre- and postintervention comparisons (P < 0.05). Significant differences were also observed for perceived chewing ability of hard foods (P < 0.05).

CONCLUSION

These results suggest that although denture adhesives do not invariably improve denture function, they do affect subjective evaluations and possibly chewing of hard foods. Therefore, the effects of denture adhesive use are insufficient to resolve any fundamental dissatisfaction with dentures ( ClinicalTrials.gov NCT01712802 ).

KNOWLEDGE TRANSFER STATEMENT

The results of this study suggest that denture adhesives should be applied under certain conditions; however, an appropriate diagnosis is important before application. These practice-based data provide information to establish evidence-based guidelines for applying denture adhesives.

Action mechanism of bleaching herbicide cyclopyrimorate, a novel homogentisate solanesyltransferase inhibitor

The action mechanism of cyclopyrimorate, a novel herbicide for weed control in rice fields, was investigated. Cyclopyrimorate caused bleaching symptoms in Arabidopsis thaliana similar to those caused by existing carotenoid biosynthesis inhibitors, mesotrione and norflurazon. However, cyclopyrimorate treatment resulted in significant accumulation of homogentisate and a reduction in the level of plastoquinone. A metabolite of cyclopyrimorate, des-morpholinocarbonyl cyclopyrimorate (DMC), was detected in plants. These data suggested that cyclopyrimorate and/or DMC inhibit homogentisate solanesyltransferase (HST), a downstream enzyme of 4-hydroxyphenylpyruvate dioxygenase in the plastoquinone biosynthesis pathway. In vitro assays showed that A. thaliana HST was strongly inhibited by DMC and weakly by cyclopyrimorate, whereas other commercial bleaching herbicides did not inhibit HST. DMC derivatives showed a positive correlation between HST inhibition and in vivo bleaching activities. These results indicate that the target site of cyclopyrimorate and DMC is HST, a novel target site of commercial herbicides.

Stress granule formation is induced by a threshold temperature rather than a temperature difference in Arabidopsis

Stress granules, a type of cytoplasmic RNA granule in eukaryotic cells, are induced in response to various environmental stresses, including high temperature. However, how high temperatures induce the formation of these stress granules in plant cells is largely unknown. Here, we characterized the process of stress granule formation in Arabidopsis thaliana by combining live imaging and electron microscopy analysis. In seedlings grown at 22°C, stress granule formation was induced at temperatures above a critical threshold level of 34°C in the absence of transpiration. The threshold temperature was the same, regardless of whether the seedlings were grown at 22°C or 4°C. High-resolution live imaging microscopy revealed that stress granule formation is not correlated with the sizes of pre-existing RNA processing bodies (P-bodies) but that the two structures often associated rapidly. Immunoelectron microscopy revealed a previously unidentified characteristic of the fine structures of Arabidopsis stress granules and P-bodies: the lack of ribosomes and the presence of characteristic electron-dense globular and filamentous structures. These results provide new insights into the universal nature of stress granules in eukaryotic cells.

Enhancement of Osteogenesis by Concanavalin a in Human Bone Marrow Mesenchymal Stem Cell Cultures

This study investigates concanavalin A (ConA) as a novel factor that may enhance osteogenesis of mesenchymal stem cells (MSCs) in vitro. Various factors, such as cytokine bone morphogenetic protein-2 (BMP-2), have been studied for their possible promotion of MSC osteogenesis in vivo and in vitro. However, the factor that might be safer, more effective, and less expensive than these has not been determined. We therefore cultured human MSCs in osteogenic medium in the presence or absence of ConA, and used calcium assays to compare the effects of ConA and BMP-2 on MSC calcification. We also used enzyme-linked immunosorbent assay (ELISA) and quantitative polymerase chain reaction (PCR) to evaluate the expression levels of bone-specific markers. ConA and BMP-2 enhanced calcification with comparable effectiveness. The combination of ConA and BMP-2 further enhanced calcification slightly but significantly. ConA also increased osteocalcin and BMP-2 protein levels in MSC culture medium. Furthermore, ConA increased osteocalcin, RUNX2, BMP-2, BMP-4, and BMP-6 mRNA expression levels. However, the gene expression pattern of ConA-stimulated MSCs was different from that of MSCs stimulated by BMP-2. Together, these results suggest that ConA and BMP-2 enhance MSC osteogenesis via different pathways. ConA-induced bone formation in MSC cultures may be useful in regenerative medicine or tissue engineering in clinical studies, as well as in basic research on bone formation.

The GYF domain protein PSIG1 dampens the induction of cell death during plant-pathogen interactions

The induction of rapid cell death is an effective strategy for plants to restrict biotrophic and hemi-biotrophic pathogens at the infection site. However, activation of cell death comes at a high cost, as dead cells will no longer be available for defense responses nor general metabolic processes. In addition, necrotrophic pathogens that thrive on dead tissue, take advantage of cell death-triggering mechanisms. Mechanisms by which plants solve this conundrum remain described. Here, we identify PLANT SMY2-TYPE ILE-GYF DOMAIN-CONTAINING PROTEIN 1 (PSIG1) and show that PSIG1 helps to restrict cell death induction during pathogen infection. Inactivation of PSIG1 does not result in spontaneous lesions, and enhanced cell death in psig1 mutants is independent of salicylic acid (SA) biosynthesis or reactive oxygen species (ROS) production. Moreover, PSIG1 interacts with SMG7, which plays a role in nonsense-mediated RNA decay (NMD), and the smg7-4 mutant allele mimics the cell death phenotype of the psig1 mutants. Intriguingly, the psig1 mutants display enhanced susceptibility to the hemi-biotrophic bacterial pathogen. These findings point to the existence and importance of the SA- and ROS-independent cell death constraining mechanism as a part of the plant immune system.

Programmed cell death (PCD) has crucial roles in development and immunity in multicellular organisms. In plants, rapid PCD induction, so-called hypersensitive response (HR) cell death, can be triggered as a part of immune system, and plays an important role in restricting pathogen growth. Despite its importance, cell death induction can backfire on plants because of the diversified infection strategies of plant pathogens. It is therefore assumed that plants have mechanisms by which they are able to minimize PCD induction during plant-pathogen interactions. However, their existence and biological significance are not clear yet. Here, we demonstrate that PSIG1, which has the GYF domain that is highly conserved among diverse eukaryotic species, restricts cell death induction during pathogen invasions. Importantly, psig1 mutants do not display autoimmune phenotypes, and are more susceptible to the virulent bacterial pathogen. Our findings suggest that the restriction of cell death can have benefits for plants to defend themselves against hemi-biotrophic bacterial pathogen infections. We further provide evidence suggesting a mechanism by which PSIG1 may contain cell death by regulating the RNA metabolism machinery.

Insights into Land Plant Evolution Garnered from the Marchantia polymorpha Genome

The evolution of land flora transformed the terrestrial environment. Land plants evolved from an ancestral charophycean alga from which they inherited developmental, biochemical, and cell biological attributes. Additional biochemical and physiological adaptations to land, and a life cycle with an alternation between multicellular haploid and diploid generations that facilitated efficient dispersal of desiccation tolerant spores, evolved in the ancestral land plant. We analyzed the genome of the liverwort Marchantia polymorpha, a member of a basal land plant lineage. Relative to charophycean algae, land plant genomes are characterized by genes encoding novel biochemical pathways, new phytohormone signaling pathways (notably auxin), expanded repertoires of signaling pathways, and increased diversity in some transcription factor families. Compared with other sequenced land plants, M. polymorpha exhibits low genetic redundancy in most regulatory pathways, with this portion of its genome resembling that predicted for the ancestral land plant. PAPERCLIP.

An unusual clinical presentation of lupus erythematosus tumidus localized on the thigh

A 44-year-old woman with seronegative polyarthritis presented with a 2-year history of a solitary, bluish-red, oedematous, nonscaly, annular and partially reticulated macule on her right thigh. Histopathological findings revealed perivascular and periadnexal lymphocytic infiltrate in the dermis. Alcian blue and colloidal iron stains highlighted mucinous deposit in the upper and mid dermis. Direct immunofluorescence showed a linear deposit of IgG and C3 along the basement membrane zone. Antinuclear antibody was positive at a titre of 1 : 80, with homogenous and speckled patterns. Except for its unusual localization and lack of photosensitivity, our case had the clinical and histopathological features of lupus erythematosus tumidus. These characteristics were also reminiscent of reticular erythematous mucinosis and erythema annulare centrifugum, both of which are considered to be associated with cutaneous lupus erythematosus (CLE). Hydroxychloroquine 200 mg daily led to improvement of the skin lesion. The unusual clinical presentation of our case emphasizes the heterogeneity of clinical manifestations of CLE.

The Biomarker Salivary SP-D May Indicate Small Airway Inflammation and Asthma Exacerbation

BACKGROUND

Noninvasive and child-friendly biomarkers are important tools for understanding the various phenotypes of childhood asthma. Objective: The aim of this study was to examine the usefulness of salivary surfactant protein (SP) D in assessing the pathophysiology of childhood asthma.

METHODS

We measured salivary concentrations of SP-D and forced oscillation technique (FOT) indexes in 19 healthy controls and 21 asthmatic children. Regression equations for the predictive values of FOT indexes were generated from healthy controls. We analyzed the correlations between salivary SP-D concentration and percentages of the predictive values of FOT indexes, as well as the severity of exacerbation.

RESULTS

We found that salivary SP-D levels were higher in asthmatic children than in healthy controls. In the asthmatic children, salivary SP-D levels correlated with the percentages of predicted differences in resistance between 5 Hz and 20 Hz (%R5-R20), which represented the resistance of peripheral airways, and with the severity of asthma exacerbation.

CONCLUSIONS

Salivary SP-D may reflect asthmatic inflammation in peripheral small airways and may be a useful marker for monitoring the degree of exacerbation in childhood asthma.

Synthesis and activities of tolprocarb derivatives against Pyricularia oryzae: relationships among the activities for polyketide synthase, melanin biosynthesis, and rice blast

The target site of tolprocarb has been reported to be polyketide synthase (PKS). Here, we evaluated the activities for Pyricularia oryzae PKS and melanin biosynthesis as well as the control efficacy of rice blast using a series of tolprocarb derivatives. A comparison of the inhibitory activities of PKS and melanin biosynthesis revealed a linear relationship (r 2=0.90), confirming PKS as the target site of tolprocarb. A compound beyond this relationship was metabolized by P. oryzae to an inactive compound. The control efficacy of rice blast was explained using the melting point and either the inhibitory activity of PKS or melanin biosynthesis. Structure-activity analysis revealed that both end parts of tolprocarb preferred hydrophobic groups, and the chirality of the substituent in the middle part significantly influenced the activities. These relationships will provide useful information for the development of novel PKS inhibitors.

Dynamic Viscoelasticity of Soft Liners and Masticatory Function

Soft denture liners are used for edentulous patients to cushion functional forces. We hypothesized that the application of soft liners having viscoelastic properties would lead to the most marked improvement in masticatory function. The shear storage modulus ( G′), shear loss modulus ( G′′), and loss tangent (tan δ) were determined for 6 materials by means of a dynamic viscoelastometer. Masticatory function of ten subjects was evaluated by measurements of maximum bite forces and chewing times and frequencies for 2 food samples, and by the use of visual analogue scales. The acrylic materials exhibited viscoelastic behavior, while the silicones exhibited elastic behavior. The improvement in masticatory function compared with hard resin was found to be in the order: acrylic permanent materials > silicone > acrylic temporary materials. The results suggest that the use of materials with higher tan δ and G′ provides the most optimum masticatory function for patients requiring the provision of soft liners on their dentures.