Utility of transcranial color flow imaging for detecting high risk morphology of patent foramen ovale in patients with cerebral infarction

Background

Micro-bubble test by using transcranial color flow imaging (TCCFI) is important as a screening evaluation for diagnosis of paradoxical cerebral embolism which requires the proof of right to left shunt at atrial septum. In addition, high risk features of patent foramen ovale (PFO) that may allow thrombus to easily pass through the PFO itself were previously reported. However, little is known about the association between the degrees on micro-bubble test by TCCFI and the features of high risk PFO.

Purpose

Our aim is to clarify the relationship between the degree of micro-bubble test in TCCFI and the morphology of PFO from transesophageal echocardiography (TEE).

Methods

Seventy-seven patients in whom cardiogenic embolism was strongly suspected by neurologists in Showa University from April to December in 2019 were retrospectively studied. 55 patients underwent both TCCFI and TEE with sufficient Valsalva stress. TCCFI grade of micro-bubble test was classified into 3 groups (A: none, B: small, and C: massive), in which signified “none” is no sign of micro-embolic signals (MES) within 30 seconds, “small” is 1 or more MES, and “massive” is so much MES look like a curtain (Figure). Evaluated high risk characteristics of PFO for cerebral embolism as previously reported were as follows; (1) tunnel height, (2) tunnel length, (3) total excursion distance into right and left atrium, (4) existence of Eustachian valve or Chiari network, (6) angle of PFO from inferior vena cava (7) large shunt (20 or more micro-bubbles).

Results

Of all TCCFI-positive patients (n=32; Group B=19, Group C=13) with cerebral embolism, PFOs were detected in 23 patients in TEE. Therefore, the sensitivity and specificity of TCCFI to PFO were 87% and 63% (AUC=0.75, p<0.001, respectively). Interestingly, all 13 patients (Group C) had manifest PFOs. Moreover, group C include 2 patients with platypnea orthodeoxia syndrome in which hypoxia in the sitting position becomes apparent. Among PFO-positive patients, tunnel height, length, total excursion distance into right and left atrium, and large shunt in TEE were significantly larger in Group C than Group B (p<0.05).

Conclusions

Micro-bubble test by using TCCFI may have screening advantages in predicting paradoxical cerebral embolism, high-risk morphology of PFO, and platypnea orthodeoxia syndrome.

Figure 1

Funding Acknowledgement

Type of funding source: None

Comparison of the Efficacy and Renal Safety of Bisphosphonate Between Low-Dose/High-Frequency and High-Dose/Low-Frequency Regimens in a Late-Stage Chronic Kidney Disease Rat Model

The efficacy and renal safety of low-dose/high-frequency (LDHF) dosing and high-dose/low-frequency (HDLF) dosing of bisphosphonates (BPs) are comparable in patients with normal kidney function but might be different in patients with late-stage chronic kidney disease (CKD). This study aimed to compare the efficacy and renal safety of two different dosage regimens of a BP, alendronate (ALN), in stage 4 CKD using a rat model. Male, 10-week-old Sprague-Dawley rats were subjected to either 5/6 nephrectomy or sham surgery. The animals received subcutaneous administration of vehicle (daily) or ALN in LDHF dosage regimen (LDHF-ALN: 0.05 mg/kg/day) or HDLF dosage regimen (HDLF-ALN: 0.70 mg/kg/2 weeks). Medications commenced at 20 weeks of age and continued for 10 weeks. Micro-computed tomography, histological analysis, infrared spectroscopic imaging, and serum and urine assays were performed to examine the efficacy and renal safety of the ALN regimens. Both LDHF-ALN and HDLF-ALN increased bone mass, improved micro-structure, and enhanced mechanical properties, without causing further renal impairment in CKD rats. Histologically, however, HDLF-ALN more efficiently suppressed bone turnover, leading to more mineralized trabecular bone, than LDHF-ALN in CKD rats, whereas such differences between LDHF-ALN and HDLF-ALN were not observed in sham rats. Both LDHF-ALN and HDLF-ALN showed therapeutic effects on high bone turnover osteoporosis in CKD stage 4 rats without causing further renal impairment. However, as HDLF-ALN more efficiently suppressed bone turnover than LDHF-ALN in late-stage CKD, HDLF-ALN might be more appropriate than LDHF-ALN for fracture prevention in high bone turnover osteoporosis patients with late-stage CKD.

Incidence and risk of antiresorptive agent-related osteonecrosis of the jaw (ARONJ) after tooth extraction in patients with autoimmune disease

INTRODUCTION

Antiresorptive agent-related osteonecrosis of the jaw (ARONJ) is a rare but serious complication in patients receiving antiresorprtive agents (AR). However, the incidence of ARONJ after tooth extraction in patients with autoimmune disease (AID) remains unclear. The present study aimed to clarify the high-risk population of ARONJ in patients with AID.

MATERIALS AND METHODS

The study population comprised 232 patients treated with AR, AID or non-AID, who had undergone dental extraction from January 2011 to September 2017. The incidence and risk factors of ARONJ were analysed retrospectively. Additionally, the relationship between ARONJ and osteoporotic fracture (OF) and AR discontinuation during dental procedures was investigated.

RESULTS

Of 232 patients, 10 developed ARONJ within 1 year of dental extraction. The incidence of ARONJ in patients with AID was higher than that in non-AID patients (2.0/100 person-year vs 0.5/100 person-year; p = 0.03). Among the AID patients, RA patients had strikingly high incidence of ARONJ (3.6/100 person-year). The incidence of neither ARONJ nor OF significantly differed between patients who continued and discontinued AR in the perioperative period.

CONCLUSION

Patients with AID who undergo dental extraction are at high risk of ARONJ. Discontinuation of AR would not significantly contribute to reduce the incidence of ARONJ in those patients.

THU0225 INTEGRATIVE PLASMA METABOLOME AND TRANSCRIPTOME ANALYSIS REVEALED THE IMPORTANCE OF HISTIDINE HOMEOSTASIS IN SLE PATHOGENESIS WITH POTENTIAL FOR IMPROVED SLE PATIENTS STRATIFICATION

Background:

Recently, immunometabolism has gathered attention of many immunologists. It has been widely recognized that metabolic reprogramming in each immune cell brings different effects on different cells and is important for regulating their functions. Along with the progress of statistical genetics, serum metabolites were shown to be under genetic regulations1). Metabolic changes are now considered not only to be mere phenotypes of cells but also to be key factors for controlling immune cell differentiation, proliferation and function through regulating gene expressions eventually. Although genome-wide association studies have brought deep insights into SLE pathogenesis, the precise pathway from genome to metabolome has been largely unknown, and vice versa.

Objectives:

The aim of this study is to investigate metabolomic regulation in SLE in relation to gene expressions by integrating plasma metabolome data and transcriptome data.

Methods:

We collected plasma samples from patients with SLE (n=57) who met the 1997 American College of Rheumatology criteria for SLE. Gender- and age-matched healthy controls (HCs) (n=56) were recruited. Metabolic profiles focusing on 39 amino acids were analyzed with liquid chromatography (LC)-mass spectrometry. Transcriptome data of SLE patients were obtained from our RNA-sequencing data of each immune cell subset (total 19 subsets). Whole-genome sequencing was also performed.

Results:

Our previous experiment showed that about 160 peaks were detected from comprehensive LC-TOFMS and amino acids were useful for distinguishing SLE patients from HCs. Both partial least squares discriminant analysis (PLS-DA) and random forest, a machine learning algorithm, revealed the importance of histidine (His), one of the essential amino acids, to classify SLE patients from HCs, whose plasma level was lower in SLE patients. In addition, inverse correlation between His level and titer of ds-DNA as well as damage index (SDI) was detected. His level was correlated neither with PSL dosage nor with type I interferon (IFN) signature. Receiver operating characteristic (ROC) analysis showed the best predictability for SLE with the combination of specific amino acids including His. Our transcriptome analysis has revealed the significance of oxidative phosphorylation (OXPHOS) in B cells for SLE pathogenesis. Interestingly, OXPHOS signature was inversely correlated with His level in SLE B cells.

Conclusion:

His may be an important factor for SLE pathogenesis especially in B cells independently from IFN signal. SLC15A4, a transporter of His on lysosome, is one of the SLE GWAS SNPs and has been reported to play an important role in IFN production in B cells through regulation of TLR7/9 activation 2). We also identified that SLE patients with risk allele of SLC15A4 had tendency to show higher plasma His level, indicating His homeostasis could become a novel treatment target for SLE. Moreover, the inverse correlation of His level to SDI as well as OXPHOS signature suggests that His might play a key role for promoting organ damages in SLE.

References:

[1]Nat Genet.2017;49:568. 2)Immunity. 2014;41:375. 3)Semin Arthritis Rheum.2019;48:1142

Disclosure of Interests: :

Yukiko Iwasaki: None declared, Yusuke Takeshima: None declared, Masahiro Nakano: None declared, Mineto Ota: None declared, Yasuo Nagafuchi: None declared, Akari Suzuki: None declared, Yuta Kochi: None declared, Tomohisa Okamura: None declared, Takaho Endo: None declared, Ichiro Miki: None declared, Kazuhiro Sakurada: None declared, Kazuhiko Yamamoto Grant/research support from: Astellas, BMS, MitsubishiTanabe, Pfizer, Ayumi, Takeda, Chugai, Eisai, Taisho Toyama, UCB, and ImmunoFuture, Keishi Fujio Grant/research support from: Astellas, BMS, MitsubishiTanabe, Pfizer, Ayumi, Takeda, Chugai, Eisai, Taisho Toyama, Eli Lilly, Sanofi, and UCB

Siglec-15-targeting therapy protects against glucocorticoid-induced osteoporosis of growing skeleton in juvenile rats

Effective treatment of juvenile osteoporosis, which is frequently caused by glucocorticoid (GC) therapy, has not been established due to limited data regarding the efficacy and adverse effects of antiresorptive therapies on the growing skeleton. We previously demonstrated that sialic acid-binding immunoglobulin-like lectin 15 (Siglec-15) targeting therapy, which interferes with osteoclast terminal differentiation in the secondary, but not primary, spongiosa, increased bone mass without adverse effects on skeletal growth, whereas bisphosphonate, a first-line treatment for osteoporosis, increased bone mass but impaired long bone growth in healthy growing rats. In the present study, we investigated the efficacy of anti-Siglec-15 neutralizing antibody (Ab) therapy against GC-induced osteoporosis in a growing rat model. GC decreased bone mass and deteriorated mechanical properties of bone, due to a disproportionate increase in bone resorption. Both anti-Siglec-15 Ab and alendronate (ALN) showed protective effects against GC-induced bone loss by suppressing bone resorption, which was more pronounced with anti-Siglec-15 Ab treatment, possibly due to a reduced negative impact on bone formation. ALN induced histological abnormalities in the growth plate and morphological abnormalities in the long bone metaphysis but did not cause significant growth retardation. Conversely, anti-Siglec-15 Ab did not show any negative impact on the growth plate and preserved normal osteoclast and chondroclast function at the primary spongiosa. Taken together, these results suggest that anti-Siglec-15 targeting therapy could be a safe and efficacious prophylactic therapy for GC-induced osteoporosis in juvenile patients.

Moderating effect of schizotypy on the relationship between smoking and neurocognition

Purpose

Smoking rates in schizotypic individuals are shown to be elevated, as in patients with schizophrenia, although findings on the association of smoking with different symptomatology of schizotypy have been mixed. Moreover, possible moderating effects of schizotypy on the relationship between smoking and cognition have not been well documented.

Subjects and methods

The Schizotypal Personality Questionnaire (SPQ) and the full version of the Wechsler Memory Scale-Revised (WMS-R) were administered to 501 healthy adults. Subjects were divided into smokers (n = 85) and non-smokers (n = 416) based on the presence/absence of current smoking.

Results

The analysis of covariance (ANCOVA) on the three factor scores as well as the total score of the SPQ, controlling for age and gender, revealed that cognitive-perceptual factor was significantly associated with an increased rate of smoking (P = 0.048). The ANCOVA on the WMS-R indices, with smoking group as a fixed factor and age, gender and total SPQ score as covariates, revealed that the schizotypy-by-smoking interaction was significant for attention/working memory (P = 0.029).

Discussion and conclusion

Positive schizotypy may be associated with more smoking. Schizotypy and smoking could interact with each other to negatively affect attention/working memory.

Pre-treatment lost to follow-up tuberculosis patients, Chongwe, Zambia, 2017: a retrospective cohort study

Setting

Four tuberculosis (TB) diagnostic health facilities of the Chongwe District, Zambia.

Objective

To determine the frequency of bacteriologically confirmed TB patients lost to follow-up (LTFU) before treatment from January to December 2017.

Design

This is a retrospective cohort study involving the review of TB registers. Information on presumptive TB patients who tested positive either by smear microscopy or Xpert^® MTB/RIF assay was extracted from the laboratory TB registers of the TB diagnostic facilities and cross-matched with the TB treatment registers of TB treatment facilities.

Results

Two hundred and seventeen bacteriologically confirmed TB patients were found in the laboratory TB registers. Of these, 145 (67%) were males and seven (3%) were children; 177 (81%) patients were diagnosed using Xpert, while the remaining 40 (19%) were diagnosed using sputum smear microscopy. A total of 71 (33%) were not linked to treatment. Those diagnosed using smear microscopy were 2.5 times (95% CI 1.1-5.3) more likely to be LTFU before treatment than those diagnosed using Xpert.

Conclusion

About one third of TB patients who were not linked to treatment could potentially extend the duration of bacilli transmission in their communities. National TB control programmes should consider including LTFU patients before treatment in routine monitoring and evaluation.

Long-term follow-up of the randomized trial of mesorectal excision with or without lateral lymph node dissection in rectal cancer (JCOG0212)

BACKGROUND

Japan Clinical Oncology Group (JCOG) 0212 (ClinicalTrials.gov NCT00190541) was a non-inferiority phase III trial of patients with clinical stage II-III rectal cancer without lateral pelvic lymph node enlargement. The trial compared mesorectal excision (ME) with ME and lateral lymph node dissection (LLND), with a primary endpoint of recurrence-free survival (RFS). The planned primary analysis at 5 years failed to confirm the non-inferiority of ME alone compared with ME and LLND. The present study aimed to compare ME alone and ME with LLND using long-term follow-up data from JCOG0212.

METHODS

Patients with clinical stage II-III rectal cancer below the peritoneal reflection and no lateral pelvic lymph node enlargement were included in this study. After surgeons confirmed R0 resection by ME, patients were randomized to receive ME alone or ME with LLND. The primary endpoint was RFS.

RESULTS

A total of 701 patients from 33 institutions were assigned to ME with LLND (351) or ME alone (350) between June 2003 and August 2010. The 7-year RFS rate was 71.1 per cent for ME with LLND and 70·7 per cent for ME alone (hazard ratio (HR) 1·09, 95 per cent c.i. 0·84 to 1·42; non-inferiority P = 0·064). Subgroup analysis showed improved RFS among patients with clinical stage III disease who underwent ME with LLND compared with ME alone (HR 1·49, 1·02 to 2·17).

CONCLUSION

Long-term follow-up data did not support the non-inferiority of ME alone compared with ME and LLND. ME with LLND is recommended for patients with clinical stage III disease, whereas LLND could be omitted in those with clinical stage II tumours.

Ten years change in post-fracture care for hip fracture patients

INTRODUCTION

This multicenter, retrospective study aimed to clarify the changes in postoperative care provided by orthopaedic surgeons after hip fractures and clarify the incidence of secondary fractures requiring surgery.

MATERIALS AND METHODS

Subjects were patients with hip fracture treated surgically in seven hospitals during the 10-year period from January 2008 to December 2017. Data on patient demographics, comorbidities, preoperative and postoperative osteoporosis treatments, and secondary fractures were collected from the medical records.

RESULTS

In total, 4764 new hip fractures in 982 men and 3782 women (mean age: 81.3 ± 10.0 years) were identified. Approximately 10% of patients had a history of osteoporosis drug treatment and 35% of patients received postoperative drug treatment. The proportion of patients receiving postoperative drug therapy increased by approximately 10% between 2009 and 2010, 10% between 2010 and 2011, and 10% between 2011 and 2013. Although the rate of secondary fractures during the entire period and within 3 years decreased from 2011, the rate of secondary fracture within 1 year remained at around 2% every year.

CONCLUSIONS

The approval of new osteoporosis drugs and the establishment of osteoporosis liaison services have had a positive effect on the use of postoperative drug therapy in the orthopedic field. Our finding that the rate of secondary fracture within 1 year of the initial fracture remained around 2% every year, despite improvements in postoperative drug therapy, suggests that both rehabilitation for preventing falls and early postoperative drug therapy are essential to prevent secondary fractures.

Preparation and evaluation of orally disintegrating tablets containing taste masked microparticles of acetaminophen

In the present work, taste masked particles of acetaminophen (AAP), a highly soluble bitter tasting drug, were developed and ODT containing the taste masked particles were prepared. Taste masked particles of AAP were prepared using different amounts of tetraglycerol polyricinoleate (TGPR) and Eudragit ®E100. Although the drug content ratio and drug recovery decreased with increasing TGPR, drug release from AAP-CR100 particles containing a large amount of TGPR was mostly suppressed for 2 min. Hence, AAP-CR100 was incorporated into ODT as taste masked particles for AAP. Three major disintegrants were used for ODT, and it was confirmed that the tensile strength of all formulations showed applicable hardness for handling. The AAP-CR100-CP(40) formulation containing crospovidone showed the shortest disintegration time and the drug release from AAP-CR100-CP(40) into pH 6.8 test solution was suppressed compared with commercial AAP tablets. Because the drug release from AAP-CR100-CP(40) into the pH 1.2 test solution was rapid, it was suggested that drug release from AAP-CR100-CP(40) is suppressed in the oral cavity, and the drug is released promptly in the stomach. Thus AAP-CR100-CP(40) may be useful as an ODT in which the dissolution of AAP in the oral cavity is suppressed.

Trends of tuberculosis rates before and after the declaration as a public health emergency in Japan, 1992–2006

SETTING: Over the period 1992 to 2006, Japan had tuberculosis (TB) notification rates of about 40 to 20 per 100 000 population. In 1999, the Minister of Health and Welfare of Japan declared a public health emergency based on the resurgence of TB.OBJECTIVE: To compare the trends of TB notification rates before and after the declaration.DESIGN: This is an ecological study on the trends of TB notification rates. The trends per year in TB notification rates were compared before (1992–1997) and after (2001–2006) the emergency declaration.RESULTS: The trends in the notification rates for all types of TB and sputum smear-positive TB (SSP-TB) decreased from −3.3% (95% confidence interval [CI] −4.6 to −1.9) and 0.94% (95%CI −0.33 to 2.2), respectively, per year before the declaration to −5.8% (95%CI −6.3 to −5.3) and −3.3% (95%CI −2.4 to −4.2), respectively, per year after the declaration with statistical significance. Trends in notification rates for both all types of TB and SSP-TB statistically significantly decreased after the declaration in Fukuoka, Osaka and Saitama Prefectures.CONCLUSION: The declaration of TB as a public health emergency in Japan in 1999 had a positive impact on TB control in Japan and thus TB epidemiology.

DS-1205b, a novel selective inhibitor of AXL kinase, blocks resistance to EGFR-tyrosine kinase inhibitors in a non-small cell lung cancer xenograft model

The AXL receptor tyrosine kinase is involved in signal transduction in malignant cells. Recent studies have shown that the AXL upregulation underlies epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI) resistance in EGFR-mutant non-small cell lung cancer (NSCLC). In this study, we investigated the effect of DS-1205b, a novel and selective inhibitor of AXL, on tumor growth and resistance to EGFR TKIs. In AXL-overexpressing NIH3T3 cells, DS-1205b potently inhibited hGAS6 ligand-induced migration in vitro and exerted significant antitumor activity in vivo. AXL was upregulated by long-term erlotinib or osimertinib treatment in HCC827 EGFR-mutant NSCLC cells, and DS-1205b treatment in combination with osimertinib or erlotinib effectively inhibited signaling downstream of EGFR in a cell-based assay. In an HCC827 EGFR-mutant NSCLC xenograft mouse model, combination treatment with DS-1205b and erlotinib significantly delayed the onset of tumor resistance compared to erlotinib monotherapy, and DS-1205b restored the antitumor activity of erlotinib in erlotinib-resistant tumors. DS-1205b also delayed the onset of resistance when used in combination with osimertinib in the model. These findings strongly suggest that DS-1205b can prolong the therapeutic benefit of EGFR TKIs in nonclinical as well as clinical settings.

Structure-Based Design and Synthesis of an Isozyme-Selective MTHFD2 Inhibitor with a Tricyclic Coumarin Scaffold

Methylenetetrahydrofolate dehydrogenase 2 (MTHFD2) plays a key role in one-carbon (1C) metabolism in human mitochondria, and its high expression correlates with poor survival of patients with various types of cancer. An isozyme-selective MTHFD2 inhibitor is highly attractive for potential use in cancer treatment. Herein, we disclose a novel isozyme-selective MTHFD2 inhibitor DS44960156, with a tricyclic coumarin scaffold, which was initially discovered via high-throughput screening (HTS) and improved using structure-based drug design (SBDD). DS44960156 would offer a good starting point for further optimization based on the following features: (1) unprecedented selectivity (>18-fold) for MTHFD2 over MTHFD1, (2) a molecular weight of less than 400, and (3) good ligand efficiency (LE).

Optimal administration frequency and dose of teriparatide for acceleration of biomechanical healing of long-bone fracture in a mouse model

Despite preclinical studies demonstrating the effectiveness of teriparatide for skeletal repair in small animals, inconclusive data from clinical trials have raised questions regarding the optimal teriparatide dosing regimen for bone repair. To address this, we assessed the effect of teriparatide frequency and dose on long-bone healing using a mouse femur osteotomy/fracture model. Eight-week-old male ICR mice were subjected to open femur osteotomies, then randomized into following five groups (n = 8 per group): vehicle; low dose/high frequency: 3 μg/kg/dose, 3 times/day; low dose/low frequency: 9 μg/kg/dose, 1 time/day; high dose/high frequency: 9 μg/kg/dose, 3 times/day; high dose/low frequency: 27 μg/kg/dose, 1 time/day. Skeletal repair was assessed by microcomputed tomography, mechanical testing, and histology 4 weeks after surgery. High-dose and/or high-frequency teriparatide treatment increased callus bone volume but failed to have a significant impact on the biomechanical recovery of fractured femurs, possibly because of impaired cortical shell formation in fracture calluses. Meanwhile, low-dose/low-frequency teriparatide therapy enhanced callus bone formation without interfering with cortical shell formation despite a lesser increase in callus bone volume, leading to significant two and fourfold increases in ultimate load and stiffness, respectively. Our findings demonstrate that administering teriparatide at higher doses and/or higher frequencies raises fracture callus volume but does not always accelerate the biomechanical recovery of fractured bone, which points to the importance of finding the optimal teriparatide dosing regimen for accelerating skeletal repair.

Potential association with early changes in serum calcium level after starting or switching to denosumab combined with eldecalcitol

The aims of this study are to investigate changes in serum calcium (Ca) level after switching from either non-therapy, bisphosphonate, selective estrogen receptor modulators (SERM) or teriparatide treatments to a combination therapy of denosumab (DMAb), and eldecalcitol, and the association between early changes in serum calcium and changes in bone metabolic markers and bone mineral density (BMD). 129 patients with postmenopausal osteoporosis (32 non-pretreatment, 50 bisphosphonates, 18 SERM, and 29 teriparatide) were recruited and switched to DMAb plus eldecalcitol. Serum calcium levels, bone metabolism markers, and BMD measurements of the lumbar spine and femoral neck were evaluated. All groups showed an increase in BMD 6 months and 1 year after DMAb administration compared to baseline via suppression of bone metabolism markers. The TPD group showed a significant decrease in serum calcium level 1 week after the first injection of DMAb and eldecalcitol compared to baseline and the bisphosphonate group. Changes in serum calcium level from baseline to 1 week after the first injection of DMAb trended to correlate with changes in bone metabolism markers and lumbar BMD. The risks of DMAb-induced hypocalcemia are different between starting and switching from bone resorption inhibitors and bone formation promoters. Therefore, appropriate assessment before administration of DMAb, including pretreatment therapy as well as serum Ca and bone metabolic markers will help identify the risk of hypocalcemia following DMAb in combination with eldecalcitol. Our findings also showed that early change in serum Ca level after DMAb initiation could potentially predict the efficacy for therapy reaction.

Siglec-15-targeting therapy increases bone mass in rats without impairing skeletal growth

The treatment of juvenile osteoporosis has not been established due to a lack of data regarding the efficacy and adverse effects of therapeutic agents. The possible adverse effects of the long-term use of antiresorptive therapies on skeletal growth in children is of particular concern. Sialic acid-binding immunoglobulin-like lectin 15 (Siglec-15) is an immunoreceptor that regulates osteoclast development and bone resorption, and its deficiency suppresses bone remodeling in the secondary spongiosa, but not in the primary spongiosa, due to a compensatory mechanism of osteoclastogenesis. This prompted us to develop an anti-Siglec-15 therapy for juvenile osteoporosis because most anti-resorptive drugs have potential adverse effects on skeletal growth. Using growing rats, we investigated the effects of an anti-Siglec-15 neutralizing antibody (Ab) on systemic bone metabolism and skeletal growth, comparing this drug to bisphosphonate, a first-line treatment for osteoporosis. Male 6-week-old F344/Jcl rats were randomized into six groups: control (PBS twice per week), anti-Siglec-15 Ab (0.25, 1, or 4 mg/kg every 3 weeks), and alendronate (ALN) (0.028 or 0.14 mg/kg twice per week). Treatment commenced at 6 weeks of age and continued for the next 6 weeks. Changes in bone mass, bone metabolism, bone strength, and skeletal growth during treatment were analyzed. Both anti-Siglec-15 therapy and ALN increased bone mass and the mechanical strength of both the femora and lumbar spines in a dose-dependent manner. Anti-Siglec-15 therapy did not have a significant effect on skeletal growth as evidenced by micro-CT-based measurements of femoral length and histology, whereas high-dose ALN resulted in growth retardation with histological abnormalities in the growth plates of femurs. This unique property of the anti-Siglec-15 Ab can probably be attributed to compensatory signaling for Siglec-15 inhibition in the primary spongiosa, but not in the secondary spongiosa. Thus, anti-Siglec-15 therapy could be a safe and effective for juvenile osteoporosis.

Tuberculosis-related technical enquiries received by a national level institution in Japan, 2014-2016

Background: Japan had a tuberculosis (TB) notification rate of 13.9 per 100 000 population in 2016. Objectives: To characterise TB-related enquiries received by the Research Institute of Tuberculosis, Tokyo, Japan, between January 2014 and December 2016. Design: A descriptive study of the time, place and other attributes of the enquiries. Results: A total of 1864 enquiries were listed for analysis. On average, 51.8 enquiries (range 30-77) were received per month. The enquiry rates were highest for Yamanashi (5.87/100 000) and Kochi (5.77) Prefectures, and lowest in Miyazaki (0.45) and Saga (0.48) Prefectures. Enquirers belonged mostly to local governments (n = 1212, 65%) and health care facilities (n = 386, 21%), and included medical doctors (n = 412, 22%), nurses (n = 926, 50%) and the general public (n = 150, 8.0%). Most enquiries concerned TB diagnosis and treatment (n = 475, 25%), including diagnosis in general (n = 38, 2.0%), laboratory diagnosis (n = 83, 4.5%), anti-tuberculosis treatment in general (n = 62, 3.3%) and the management of comorbidities or adverse events (n = 60, 3.2%), followed by contact investigations (n = 371, 20%). Conclusions: As most enquiries concerned the diagnosis and treatment of TB, the Ministry of Health of Japan should maintain a number of specialised TB institutions with TB clinicians to provide technical assistance.