The impact of rare cancer and early-line treatments on the benefit of comprehensive genome profiling-based precision oncology

BACKGROUND

Comprehensive genome profiling (CGP) serves as a guide for suitable genomically matched therapies for patients with cancer. However, little is known about the impact of the timing and types of cancer on the therapeutic benefit of CGP.

MATERIALS AND METHODS

A single hospital-based pan-cancer prospective study (TOP-GEAR; UMIN000011141) was conducted to examine the benefit of CGP with respect to the timing and types of cancer. Patients with advanced solid tumors (>30 types) who either progressed with or without standard treatments were genotyped using a single CGP test. The subjects were followed up for a median duration of 590 days to examine therapeutic response, using progression-free survival (PFS), PFS ratio, and factors associated with therapeutic response.

RESULTS

Among the 507 patients, 62 (12.2%) received matched therapies with an overall response rate (ORR) of 32.3%. The PFS ratios (≥1.3) were observed in 46.3% (19/41) of the evaluated patients. The proportion of subjects receiving such therapies in the rare cancer cohort was lower than that in the non-rare cancer cohort (9.6% and 17.4%, respectively; P = 0.010). However, ORR of the rare cancer patients was higher than that in the non-rare cancer cohort (43.8% and 20.0%, respectively; P = 0.046). Moreover, ORR of matched therapies in the first or second line after receiving the CGP test was higher than that in the third or later lines (62.5% and 21.7%, respectively; P = 0.003). Rare cancer and early-line treatment were significantly and independently associated with ORR of matched therapies in multivariable analysis (P = 0.017 and 0.004, respectively).

CONCLUSION

Patients with rare cancer preferentially benefited from tumor mutation profiling by increasing the chances of therapeutic response to matched therapies. Early-line treatments after profiling increase the therapeutic benefit, irrespective of tumor types.

Sex-specific associations of evening blood pressure burden and cardiac load with nocturia severity in the Japanese at high-risk of cardiovascular disease

Background

Earlier epidemiologic studies have reported a significant relationship between hypertension and nocturia. However, the underlying pathophysiology has not been established. We hypothesized that blood pressure (BP) burden, the classes of antihypertensive agents and cardiac load were associated with severity of nocturia, and that these associations might be moderated by gender.

Purpose

To investigate the relationships of home BP (HBP) level, the class of antihypertensive agent, brain natriuretic peptide (BNP) with nocturia severity, and to investigate these associations stratified by gender in the Japanese at high-risk of cardiovascular disease.

Methods

In the Japan Morning Surge-Home Blood Pressure Study, measurements of HBP at evening (mean 11.2 days) as well as BNP were performed in the 4310 patients with one or more cardiovascular risks (64.9 years old, male 47%). A self-administered questionnaire included items on nocturia was used.

Results

According to the number of nocturia (no void: n=2382; one void: n=847; >2 voids per night: n=1082), significant associations of systolic BP (SBP) at evening (130 vs 130 vs 132 mmHg, p<0.0001) and logBNP (1.20 vs 1.30 vs 1.42, p<0.0001) were observed with nocturia severity. In the multinomial logistic regression analysis adjustment for confounders including age, smoking, total cholesterol, fasting blood glucose, HbA1c and clinic SBP, the use of diuretics (OR: 1.26, 95% CI: 1.06–1.52, p<0.05) was significantly associated with one nocturnal void, while evening SBP (OR: 1.009, 95% CI: 1.003–1.014, p<0.01) and logBNP (1.43, 95% CI: 1.19–1.73, p<0.001) were significantly associated with multiple nocturnal voids. While no significant interaction was found between evening SBP and logBNP for multiple nocturnal voids in the total population, a significant interaction was found between evening SBP and logBNP for multiple nocturnal voids in females (p<0.05).

Conclusions

In this study, the use of diuretics was a significant indicator of single nocturnal void, while evening SBP and BNP were those of multiple nocturnal voids in the high-risk Japanese population. Specifically, in the females, treatment to reduce BP burden as well as cardiac overload might be important to improve sleep disturbance caused by nocturia.

Funding Acknowledgement

Type of funding sources: None.

Is warfarin associated with higher risk of thrombus in left atrial appendage than direct oral anticoagulants?

Funding Acknowledgements

Type of funding sources: None.

Background

Thrombus in left atrial appendage (LAA) is associated with cardiogenic ischemic stroke, and anticoagulation therapy is utilized to prevent thromboembolism.

Purpose

This study is to investigate the incidence of thrombus in left atrial appendage detected by transoesophageal echocardiography (TOE) under anticoagulation therapy with warfarin or direct oral anticoagulants (DOAC).

Methods

Between 2005 and 2016, the patients who underwent TOE under anticoagulation therapy due to atrial fibrillation more than one month were enrolled in this study. The patients were divided into 2 groups according to whether treated with warfarin or DOAC and baseline characteristics and incidence of LAA thrombus were assessed.

Results

Among the 313 study patients, 243 (78%) were treated with warfarin. The patients treated with warfarin were elder (median 73 y vs. 67 y [interquartile range 66 – 78 y vs. 58 – 72 y], P < 0.01), the body mass index was lower (23.2 vs. 24.0 [21.0 – 25.4 vs. 21.3 – 26.9], P = 0.03). The prevalence of male sex (64% vs. 71%, P = 0.26) were similar between the 2 groups. The previous history of hypertension (69% vs. 59%, P = 0.10), diabetes (24% vs. 19%, P = 0.32), vascular disease (30% vs. 26%, P = 0.52), and ischemic stroke were similar between the 2 groups (30% vs. 23%, P = 0.22). The prevalence of CHA2DS2-VASc score > 1 (84% vs. 59%, P < 0.01) and the d-dimer level (0.7 vs. 0.5 mcg/ml [0.5 – 1.8 vs. 0.5 – 0.5 mcg/ml], P < 0.01) were higher in the warfarin groups than those of the DOAC. The velocity of LAA was slower in the warfarin group than those of DOAC (35 vs. 55 cm/s [21 – 54 vs. 38 – 68 cm/s], P < 0.01). The incidence of detection of LAA thrombus was 19% in the warfarin group and 3% in the DOAC group (P < 0.01). In the warfarin group, the PT-INR were lower in the patients with LAA thrombus (1.38 vs. 1.66 [1.11 – 1.92 vs. 1.34 – 2.03], P = 0.03).

Conclusions

The higher risk of ischemic stroke and out of range PT-INR may be the cause of the higher incidence of LAA thrombus in the patients treated with warfarin than those with DOAC.

Abstract Figure.

Prognosis and cause of death in patients with left atrial appendage thrombus treated with or without anticoagulation therapy

Background

Thrombus in left atrial appendage (LAA) is associated with cardiogenic ischemic stroke; however, little is known about prognosis of patients with LAA thrombus detected by transoesophageal echocardiography (TOE).

Purpose

This study is to investigate the prognosis of patients with LAA thrombus and their cause of death.

Methods

Between 2005 and 2016, the patients who were performed TOE in our hospital were enrolled in this retrospective observational study. Five-year stroke free and survival curves were constructed by Kaplan-Meir method and cause of death were assessed.

Results

Among the 1263 study patients, LAA thrombus was detected in 146 (12%) patients. The patients with LAA thrombus were elder (74 y [66–79 y] vs. 70 y [62–76 y], P<0.001), than those without LAA thrombus, respectively. The prevalence of male sex (67% vs. 69%, P=0.63) were similar between the 2 groups. The prevalence of CHA2DS2-VASc score ≥2, d-dimer (1.7 mcg/ml [0.9–3.5 mcg/ml] vs. 0.8 mcg/ml [0.5–2.2 mcg/ml], P<0.001), and plasma brain natriuretic peptide (315 pg/ml [128–515 pg/ml] vs. 126 pg/ml [47–284 pg/ml], P<0.001) were higher in the patients with LAA thrombus than those without (89% vs. 78%, P=0.003). The LAA velocity was slower in the patients with LAA thrombus than those without (23 cm/s [15–34 cm/s] vs. 51 cm/s [35–72 cm/s], P<0.001). The prevalence of receiving anticoagulation therapy before (34% vs. 24%, P=0.01) and after (98% vs. 66%, P<0.001) TOE 1 month were higher in the patients with LAA thrombus than those without. The 5-year stroke free rate was lower in the patients with LAA thrombus than those without (82% vs. 93%, P<0.001); however, the 5-year survival were similar between the 2 groups (84% vs. 84%, P=0.93) (Figure). The cause of death as ischemic stroke was only 7% (1/14) and 3% (3/94), (P=0.43); the cardiac cause (14% vs. 43%, P=0.07) and the malignancy (35% vs. 29%, P=0.75) were the frequent cause of death in the patient with LAA thrombus and those without, respectively.

Conclusions

The patients who were detected thrombus in the LAA had higher incidence of ischemic stroke; however, the 5-y survival were similar. The ischemic stroke was not major cause of death in the patients with and without LAA thrombus. The higher rate of receiving anticoagulation therapy may be one of the causes of the discrepancy.

Figure 1

Funding Acknowledgement

Type of funding source: None

Sex-dependent association between day-by-day morning blood pressure variability and common carotid artery intima-media thickness: the J-HOP study

Background

Day-by-day home systolic blood pressure variability (BPV) was shown to be associated with increased common carotid artery (CCA) intima-media thickness (IMT) in the hypertensives. Recently, 24 hour ambulatory BPV was revealed to serve as an indicator of higher CCA-IMT only in males. However, there have been no studies that reported the sex-dependent relationship between day-by-day BPV and CCA-IMT.

Purpose

We assessed the hypothesis that day-by-day BPV was associated with higher CCA-IMT in the Japanese males at high-risk of cardiovascular disease.

Methods

Among 4310 patients with one or more cardiovascular risks recruited for the Japan Morning Surge-Home Blood Pressure Study, carotid ultrasound in CCA was performed in the 1365 patients (mean age 65.6 years old, male 52%). The home blood pressure (BP) readings during mean 11.2 days were used to calculate home mean levels and variability in morning systolic BP (SBP). Day-by-day BPV was measured as standard deviation [SD] and delta (maximum-minimum) in SBP.

Results

Average mean CCA-IMT of left and right side was 1.046±0.4mm. Mean (r=0.118, p<0.0001), SD (r=0.120, p<0.0001) and delta (r=0.149, p<0.0001) in morning SBP were significantly correlated with CCA-IMT. In the multiple regression analysis adjustment for confounders including age, gender, body mass index, total cholesterol, high density lipoprotein and mean morning SBP, SD (B: 0.008, 95% CI: 0.001–0.015, p<0.05) or delta (B: 0.004, 95% CI: 0.002–0.006, p<0.001) in morning SBP each had a significant association with CCA-IMT. According to the gender, SD (p<0.01) or delta (p<0.01) in morning SBP each was significantly associated with CCA-IMT only in the male group while neither SD (p=0.4) nor delta (p=0.4) in morning SBP was associated with CCA-IMT in the female group.

Conclusions

In addition to the conventional risk factors, day-by-day morning SBP variability was a significant indicator of increased CCA-IMT in the high-risk Japanese population. The significant relationship between day-by-day morning SBP variability and CCA-IMT was observed only in the males. Gender specific impact of day-by-day morning home systolic BPV on carotid artery atherosclerosis should be taken into account in the high-risk elderly at cardiovascular disease.

Funding Acknowledgement

Type of funding source: None

P684 Paradoxical cerebral infarction due to massive pulmonary embolism in extracorporeal cardiopulmonary resuscitation and surgical embolectomy

Introduction

Paradoxical cerebral infarction is a mechanism of acute ischemic stroke; however, definitive images to diagnose paradoxical embolism are not often obtained. We report a case of paradoxical cerebral embolism complicated with cardiac arrest due to massive pulmonary embolism.

Case report

A 40-year-old man presented due to sudden-onset chest pain, and was admitted to our hospital. He was restless and had cold sweat; we could not measure blood pressure. Electrocardiography showed wide QRS complex with right bundle branch block, and T wave inversion in leads V1 and III. Transthoracic echocardiography showed diffuse severe left ventricular hypokinesis, with slightly better inferior wall motion compared to other segments. Few minutes after arriving, he experienced cardiac arrest; chest compression was initiated. He was transported to the catheter laboratory, and veno-arterial extracorporeal membrane oxygenation was initiated subsequently. To diagnose the cause of arrest, we performed coronary angiography, which revealed no occluded coronary artery. Pulmonary angiograms showed bilateral proximal pulmonary artery occlusion with massive thrombi (panel A). Surgical embolectomy was performed after cardiac team discussion. After ICU admission post-surgery, pericardial effusion was increased, and the blood drained continuously from the chest tube; a large amount of blood transfusion was required. Reopen chest haemostasis was utilised. After the second ICU admission, anisocoria was observed; subsequent computed tomography showed low density and midline shift in almost the entire left cerebral hemisphere (Panel B). Carotid duplex ultrasound revealed a large thrombus saddled at the left carotid artery bifurcation (Panel C and D). We rechecked the transthoracic echocardiogram at arrival to reveal the cause of the cerebral infarction, which showed the thrombus to be at the ascending aorta (Panel E). We thought that the thrombi had moved from the lower limb to the right atrium. The massive pulmonary embolism increased the pulmonary artery and right atrial pressure, resulting in the lower pressure of the left atrium compared to that of the right atrium. The thrombi passed through the patent foramen ovale into the left atrium, moved into the left ventricle, and embolised the left internal carotid artery (Panel F). He expired due to severe neurologic injury from brain herniation.

Conclusion

In this case, although the pulmonary embolism was massive and led to cardiac arrest, the deteriorated haemodynamics improved by extracorporeal cardiopulmonary resuscitation and surgical embolectomy. However, we could not rescue the patient because of the severe neurological injury due to paradoxical embolism. Paradoxical cerebral infarction in pulmonary embolism is rare; however, we should pay careful attention to early detection of paradoxical cerebral infarction in pulmonary embolism and treatment for return of the patient to the former lifestyle.

Abstract P684 figure

P765 Does detection of thrombus in left atrial appendage increase risk of ischemic stroke and mortality?

Background

Left atrial appendage (LAA) thrombus is one of causes of cardiogenic stroke and detection of LAA thrombus by transoesophageal echocardiography (TOE) strongly suggest cardiogenic stroke. It was reported that cardiogenic stroke patients had higher in-hospital mortality about 19%; however, little is known about LAA thrombus and mortality after indexed detection of LAA thrombus. We investigated LAA thrombus detection and their prognosis including ischemic stroke and survival.

Methods

The patients who were performed TOE between 2005 and 2016 in our hospital were enrolled in this study. Patients were divided into 2 groups based on thrombus detection in the LAA, and baseline characteristics and outcomes including prevalence of 5-y stroke-free and survival from the indexed TOE were compared.

Results

Among the 1260 study patients, the follow-up duration was median 971 d (interquartile range 345 d – 2017 d), and 67% of the patients were performing TOE for atrial fibrillation (AF), 20% for cerebral infarction, and 14% for valvular heart disease. Non-valvular AF was seen in 64% of the study patients and rheumatic AF was in 2%. The age (74 y [66 y – 79 y] vs 70 y [62 y – 76 y], p < 0.001), the prevalence of male sex (67% vs 69%, p = 0.63), and hemoglobin level (13.9 g/dl [12.5 – 15.1 g/dl] vs 13.8 g/dl [12.4 – 14.9 g/dl], p = 0.49) were similar between the patients with LAA thrombus and those without. The CHA2DS2-VASc score (p = 0.008), the prevalence of receiving anticoagulation before TOA (34% vs 24%, p = 0.01), those of after TOA (98% vs 66%, p < 0.001), serum creatinine (0.92 mg/dl [0.80 – 1.10 mg/dl] vs 0.85 mg/dl [0.71 – 1.00 mg/dl], p < 0.001), d-dimer level (1.7 mcg/ml [0.9 – 3.5 mcg/ml] vs 0.8 mcg/ml [0.5 – 2.2 mcg/ml], p < 0.001), and plasma brain natriuretic peptide (315 pg/ml [128 – 515 pg/ml] vs 126 pg/ml [47 – 284 pg/ml], p < 0.001) were higher in the patients with LAA thrombus than those without. The 5-y ischemic stroke-free rate was lower in the patients with LAA thrombus than those without (p < 0.001) (Figure, Panel A); however, the 5-y survival was similar between the 2 groups (p = 0.93) (Panel B).

Conclusions

The patients who were detected thrombus in the LAA had higher incidence of ischemic stroke, but the survival rate were similar. The higher rate of receiving anticoagulation therapy in the patients with LAA thrombus may be the cause of this discrepancy. Further studies are necessary to clarify this issue.

Abstract P765 Figure

Reasons for discontinuation of contraception among women with a current unintended pregnancy in 36 low and middle-income countries

OBJECTIVES

To explore the reasons for discontinuation of the last contraceptive method used in women with a current unintended pregnancy.

STUDY DESIGN

We conducted a retrospective analysis using contraceptive calendar data from Demographic and Health Surveys from 36 low- and middle-income countries from 2005 through 2014. The prevalence of contraception utilization and the contribution of each reason for contraceptive discontinuation was calculated, at country level as well as for the pooled dataset, for 10,901 women aged 15-49 before the current unintended pregnancies.

RESULTS

Unintended pregnancies ranged from 5.5% of all pregnancies in the Kyrgyz Republic to 60.0% in Colombia and Peru. In Central Asian and in six African countries, over 80% of women with a current unintended pregnancy had not used any contraceptives in the previous five years. Use of long-acting modern methods remained consistently low across all countries. Among women who last used a traditional method, 83.8% discontinued due to failure. Among women who last used a long-acting modern method, 40.2% discontinued because of side effects.

CONCLUSIONS

Our findings confirm that more than 65.0% of women with an unintended pregnancy in 36 low and middle-income countries were either non-users or using traditional methods. An additional 31.2% were using short-acting modern methods. Long-acting methods would have prevented the overwhelming majority of unintended pregnancies.

IMPLICATIONS

This paper shows the need for the health system to support use of suitable methods, reduce switching failure and identify early when women are having concerns about the method they are using.

P4548Early drop in systolic blood pressure and worsening renal function in the elderly acute heart failure: how does heart rate interact?

Background

Renal dysfunction is a frequent finding in patients hospitalized for acute heart failure (AHF). Worsening renal function (WRF) during hospitalization was found to be related with a poor outcome independently of baseline renal function. Early drop in systolic blood pressure (SBP) has shown to predict WRF in AHF. However, there have been few studies that reported the impact of on-admission heart rate (HR) on the relationship between early SBP drop and WRF in the elderly AHF.

Purpose

We assessed the hypothesis that early SBP drop predict WRF in the elderly patients with AHF, and investigated that on-admission HR might have an interaction with that relationship.

Methods

SBP and HR were measured on admission and 6 times during 48 hours in the 245 elderly AHF inpatients (82.9±6.0 years old, male 49.4%). WRF was defined as a serum creatinine increase of ≥0.3 mg/dL by Day 5. Early drop in SBP was calculated as the difference between admission and the lowest value measured during the first 48 hour of hospitalization.

Results

Early SBP drop (51.3 vs 32.5mmHg, p<0.01) and on-admission HR (79.3 vs 89.6bpm, p<0.05) were significantly different between the group with WRF (n=36) and the group without WRF (n=209). In the multiple logistic regression analysis adjusted for the confounders including age, gender, hypertension, left ventricular ejection fraction, total cholesterol, BNP, baseline creatinine, beta-blockade use, intravenous loop diuretic, isosorbide dinitrate and carperitide use, early SBP drop (OR: 1.003, 95% CI: 1.003–1.03, p<0.04) and on-admission HR (OR: 0.98, 95% CI: 0.96–0.99, p<0.01) were significantly associated with WRF. The interaction term of early SBP drop by on-admission HR did not have a significant association with WRF (p=0.3).

Conclusions

In the elderly AHF patients, exaggerated early SBP drop and lower on-admission HR were shown as significant independent predictors of WRF. These two factors were additively associated with WRF. Too much reduction in SBP and that in HR might be harmful to renal circulation in AHF.

Status of the GroundBIRD Telescope

Our understanding of physics at very early Universe, as early as 10−35 s after the Big Bang, relies on the scenario known as the inflationary cosmology. Inflation predicts a particular polarization pattern in the cosmic microwave background, known as the B-mode yet the strength of such polarization pattern is extremely weak. To search for the B-mode of the polarization in the cosmic microwave background, we are constructing an off-axis rotating telescope to mitigate systematic effects as well as to maximize the sky coverage of the observation. We will discuss the present status of the GroundBIRD telescope.

Physiological exercise loading suppresses post-traumatic osteoarthritis progression via an increase in bone morphogenetic proteins expression in an experimental rat knee model

OBJECTIVE

To evaluate the dose-response relationship of exercise loading in the cartilage-subchondral bone (SB) unit in surgically-induced post-traumatic osteoarthritis (PTOA) of the knee.

DESIGN

Destabilized medial meniscus (DMM) surgery was performed on the right knee of 12-week-old male Wistar rats, and sham surgery was performed on the contralateral knee. Four weeks after the surgery, the animals were subjected to moderate (12 m/min) or intense (21 m/min) treadmill exercises for 30 min/day, 5 days/week for 4 weeks. PTOA development in articular cartilage and SB was examined using histological and immunohistochemical analyses, micro-computed tomography (micro-CT) analysis, and biomechanical testing at 8 weeks after surgery. Gremlin-1 was injected to determine the role of bone morphogenetic protein (BMP) signaling on PTOA development following moderate exercise.

RESULTS

Moderate exercise increased BMP-2, BMP-4, BMP-6, BMP receptor 2, pSmad-5, and inhibitor of DNA binding protein-1 expression in the superficial zone chondrocytes and suppressed cartilage degeneration, osteophyte growth, SB damage, and osteoclast-mediated SB resorption. However, intense exercise had little effect on BMP expression and even caused progression of these osteoarthritis (OA) changes. Gremlin-1 injection following moderate exercise caused progression of the PTOA development down to the level of the non-exercise DMM-operated knee.

CONCLUSIONS

Exercise regulated cartilage-SB PTOA development in DMM-operated knees in a dose-dependent manner. Our findings shed light on the important role of BMP expression in superficial zone chondrocytes in attenuation of PTOA development following physiological exercise loading. Further studies to support a mechanism by which BMPs would be beneficial in preventing PTOA progression are warranted.

Liver transection using indocyanine green fluorescence imaging and hepatic vein clamping

BACKGROUND

Three-dimensional (3D) imaging has facilitated liver resection with excision of hepatic veins by estimating the liver volume of portal and hepatic venous territories. However, 3D imaging cannot be used for real-time navigation to determine the liver transection line. This study assessed the value of indocyanine green (ICG) fluorescence imaging with hepatic vein clamping for navigation during liver transection.

METHODS

Consecutive patients who underwent liver resection with excision of major hepatic veins between 2012 and 2013 were evaluated using ICG fluorescence imaging after clamping veins and injecting ICG. Regional fluorescence intensity (FI) values of non-veno-occlusive regions (FI_Non ), veno-occlusive regions (FI_VO ) and ischaemic regions (FI_IS ) were calculated using luminance analysing software.

RESULTS

Of the 21 patients, ten, four and seven underwent limited resection, monosegmentectomy/sectionectomy and hemihepatectomy respectively, with excision of major hepatic veins. Median veno-occlusive liver volume was 80 (range 30-458) ml. Fluorescence imaging visualized veno-occlusive regions as territories with lower FI compared with non-veno-occlusive regions, and ischaemic regions as territories with no fluorescence after intravenous ICG injection. Median FI_IS /FI_Non was lower than median FI_VO /FI_Non (0·22 versus 0·59; P = 0·002). There were no deaths in hospital or within 30 days, and only one major complication.

CONCLUSION

ICG fluorescence imaging with hepatic vein clamping visualized non-veno-occlusive, veno-occlusive and ischaemic regions. This technique may guide liver transection by intraoperative navigation, enhancing the safety and accuracy of liver resection.

Function of Platelet-Induced Epithelial Attachment at Titanium Surfaces Inhibits Microbial Colonization

The aim of this study was to evaluate the barrier function of platelet-induced epithelial sheets on titanium surfaces. The lack of functional peri-implant epithelial sealing with basal lamina (BL) attachment at the interface of the implant and the adjacent epithelium allows for bacterial invasion, which may lead to peri-implantitis. Although various approaches have been reported to combat bacterial infection by surface modifications to titanium, none of these have been successful in a clinical application. In our previous study, surface modification with protease-activated receptor 4–activating peptide (PAR4-AP), which induced platelet activation and aggregation, was successful in demonstrating epithelial attachment via BL and epithelial sheet formation on the titanium surface. We hypothesized that the platelet-induced epithelial sheet on PAR4-AP–modified titanium surfaces would reduce bacterial attachment, penetration, and invasion. Titanium surface was modified with PAR4-AP and incubated with platelet-rich plasma (PRP). The aggregated platelets released collagen IV, a critical BL component, onto the PAR4-AP–modified titanium surface. Then, human gingival epithelial cells were seeded on the modified titanium surface and formed epithelial sheets. Green fluorescent protein (GFP)–expressing Escherichia coli was cultured onto PAR4-AP–modified titanium with and without epithelial sheet formation. While Escherichia coli accumulated densely onto the PAR4-AP titanium lacking epithelial sheet, few Escherichia coli were observed on the epithelial sheet on the PAR4-AP surface. No bacterial invasion into the interface of the epithelial sheet and the titanium surface was observed. These in vitro results indicate the efficacy of a platelet-induced epithelial barrier that functions to prevent bacterial attachment, penetration, and invasion on PAR4-AP–modified titanium.

Activation of c-Jun N-terminal kinase by Akabane virus is required for apoptosis

Akabane virus (AKAV) belongs to the Simbu serogroup of the genus Orthobunyavirus in the family Bunyaviridae. It has been shown that AKAV induces apoptosis in mammalian cells. It is necessary to understand the signaling pathways involved in AKAV-induced apoptosis to further elucidate the molecular virology of AKAV. c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK) are mediators of apoptosis; therefore, we investigated the roles of JNK and p38 MAPK cascades in AKAV-infected cells. We found that JNK and p38 MAPK as well as their downstream substrates, c-Jun and heat shock protein 27 (HSP27), were phosphorylated in response to AKAV infection. A JNK inhibitor (SP600125) inhibited AKAV-mediated apoptosis whereas a p38 MAPK inhibitor (SB203580) did not. We conclude that AKAV infection activates the JNK and p38 MAPK signaling pathways, and the JNK cascade plays a crucial role in AKAV-induced apoptosis in vitro.

•

JNK and p38 MAPK were phosphorylated in response to Akabane virus infection.

•

Downstream substrates, c-Jun and heat shock protein 27, were also phosphorylated by viral infection.

•

JNK inhibitor (SP600125) inhibited AKAV-mediated apoptosis whereas a p38 MAPK inhibitor (SB203580) did not.

Exercise intervention increases expression of bone morphogenetic proteins and prevents the progression of cartilage-subchondral bone lesions in a post-traumatic rat knee model

OBJECTIVE

This study aimed to determine whether treadmill walking (TW) prevents the progression of post-traumatic osteoarthritic changes in cartilage-subchondral bone unit, and whether the exercise timing changes the exercise efficacy in destabilized medial meniscus (DMM) rat knees.

DESIGN

Twelve-week-old male Wistar rats underwent DMM surgery on their right knees and sham surgery on their left knees and were assigned to either the sedentary (n = 10) or walking (n = 24) groups. The rats in the walking group were subjected to TW from day 2 through 4 weeks, from 4 through 8 weeks, or from day 2 through 8 weeks (n = 8 per group). Osteoarthritic changes of cartilage and subchondral bone were assessed with micro-computed tomography, histology, and immunohistochemistry 8 weeks after surgery.

RESULTS

TW prevented the progression of cartilage and subchondral bone lesions induced by the DMM, and increased bone morphogenetic protein (BMP)-2 and -6 expressions in superficial zone chondrocytes and bone-lining cells including osteoblasts. Furthermore, the TW-induced increase in BMPs varied with the exercise timing. Beginning TW 4 weeks after DMM surgery was the best option for increasing BMPs, coinciding with the most robust prevention of osteoarthritic changes.

CONCLUSIONS

TW increased the expression of BMPs and prevented the progression of cartilage-subchondral bone lesions in rat knees with a DMM. Selective exercise timing may be a key factor in the development of an exercise regimen for preventing the progression of post-traumatic osteoarthritis (PTOA). Furthermore, exercise may have favorable effects even after the PTOA has been developed.

Serum levels of the soluble haemoglobin scavenger receptor CD163 in MPO-ANCA-associated renal vasculitis

OBJECTIVES

The contribution of infections to the mortality of patients with anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is important, and early and careful infection control is necessary. We investigated the usefulness of the serum-soluble haemoglobin scavenger receptor CD163 for detecting the presence of infectious complications regardless of disease activity.

METHOD

Soluble CD163 in serum obtained from 45 Japanese patients with myeloperoxidase (MPO)-AAV was measured by an enzyme-linked immunosorbent assay (ELISA). We evaluated 36 samples from active-vasculitis patients, 36 samples from inactive-vasculitis patients without infection, and 19 samples from inactive-vasculitis patients with infectious complications. Serum-soluble CD163 was also measured in 15 infectious patients without vasculitis and in 30 normal controls.

RESULTS

The mean serum-soluble CD163 level was higher in the patients with infectious complications than in the active-vasculitis patients, inactive-vasculitis patients, and normal controls. There were significant positive correlations between serum-soluble CD163 levels and white blood cell (WBC) count, serum C-reactive protein (CRP) levels, and serum albumin levels, but only serum CRP levels were correlated with serum-soluble CD163 levels in a multiple regression analysis. On the receiver-operating characteristic (ROC) curve, serum-soluble CD163 levels had 80.6% sensitivity and 86.7% specificity for differentiating patients with infection from those without infection. Among the active-vasculitis patients, the mean serum-soluble CD163 level of the patients with alveolar haemorrhage was significantly lower than that of the patients with interstitial lung diseases and that of the patients without pulmonary lesions.

CONCLUSIONS

The serum-soluble CD163 level may be a useful marker for the detection of infectious complications in MPO-AAV patients.

Subchondral plate porosity colocalizes with the point of mechanical load during ambulation in a rat knee model of post-traumatic osteoarthritis

OBJECTIVE

This study investigated the association between spatiotemporal cartilage-subchondral bone plate alterations and mechanical load during ambulation in an experimental rat model of destabilized medial meniscus (DMM).

DESIGN

Twelve-week-old Wistar rats (n = 38) underwent DMM surgery on the right knee and sham surgery on the left knee. At 2 and 4 weeks after surgery, subchondral bone changes were evaluated via micro-computed tomography with various knee flexion angles to simulate weight-bearing during rat ambulation under a 3-dimensional motion capture apparatus. Additionally, the biomechanical properties, histology, and ultrastructure of the medial tibia and femoral condyle were evaluated.

RESULTS

Focal subchondral bone plate perforations were confirmed in the medial tibia within 2 weeks after surgery and were aggravated rapidly 2 weeks later. This subchondral plate porosity colocalized with articular cartilage lesions as confirmed by histology and scanning electron microscopy, and coincided with the likely point of contact between the posterior femoral condyle and tibial plateau during ambulation. Biomechanical properties were confirmed at the medial tibia, at which stiffness was reduced to approximately half that of the sham-operated knee at 4 weeks after surgery.

CONCLUSIONS

Cartilage-subchondral bone plate alterations localized in the region of the point of mechanical load during ambulation in DMM-operated knees, at which the mechanical integrity of cartilage was impaired. These results indicate that DMM-induced increases in mechanical load play an important role in the pathogenesis of early post-traumatic osteoarthritis (OA), and it might accelerate the development of the disease via cartilage-subchondral bone plate crosstalk through increased subchondral plate perforations.