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.

Semi-mechanistic autoinduction model of midazolam in critically ill patients: population pharmacokinetic analysis

WHAT IS KNOWN AND OBJECTIVE

Midazolam (MDZ) is commonly used for sedating critically ill patients. The daily dose required for adequate sedation increases in increments over 100 h after administration. The objectives of this study were to characterize the MDZ pharmacokinetics in critically ill patients and to describe the phenomenon of increasing daily dose by means of population pharmacokinetic analysis.

METHODS

Data were obtained from 30 patients treated in an intensive care unit. The patients received MDZ intravenously as a combination of bolus and continuous infusion. Serum MDZ concentration was assayed by high-performance liquid chromatography. Population pharmacokinetic analysis was performed using the NONMEM software package. The alteration of clearance unexplained by demographic factors and clinical laboratory data was described as an autoinduction of MDZ clearance using a semi-mechanistic pharmacokinetic-enzyme turnover model.

RESULTS AND DISCUSSION

The final population pharmacokinetic model was a one-compartment model estimated by incorporating a semi-mechanistic pharmacokinetic-enzyme turnover model for clearance, taking autoinduction into account. A significant covariate for MDZ clearance was total bilirubin. An increase in total bilirubin indicated a reduction in MDZ clearance. From simulation using the population pharmacokinetic parameters obtained in this study, MDZ clearance increased 2·3 times compared with pre-induced clearance 100 h after the start of 12·5 mg/h continuous infusion.

WHAT IS NEW AND CONCLUSION

Autoinduction and total bilirubin were significant predictors of the clearance of MDZ in this population. Step-by-step dosage adjustment using this population pharmacokinetic model may be useful for establishing a MDZ dosage regimen in critically ill patients.

Nutritional Supplementation during Resistance Training Improved Skeletal Muscle Mass in Community-Dwelling Frail Older Adults

OBJECTIVE

Sarcopenia, the age-related loss of skeletal muscle mass, is highly prevalent in older adults. The aim of this study was to investigate the effects of the combination of resistance training and multinutrients supplementation (including vitamin D and protein) on muscle mass and physical performance in frail older adults.

METHODS

This trial was conducted in Japanese frail older adults (n=77), which underwent a standardized protocol of a 3-month physical exercise intervention. The sample population was divided into two groups, according to the adoption (S/Ex: n = 38) or not (Ex: n = 39) of the additional multinutrient supplementation. The outcome measures of interest for the present analyses were the skeletal muscle mass index (SMI) and several physical performance tests.

RESULTS

Participants in S/Ex group had significant improvements for the outcome measures, including SMI and maximum walking time (P<0.05), compared to those in Ex group. The prevalence of sarcopenia decreased from 65.7% to 42.9% in S/Ex group, while that in Ex group remained unchanged (68.6% to 68.6%) (relative risk = 1.60, 95% CI: 1.03-2.49).

CONCLUSION

The results of this study suggest that the combination of resistance training and multinutritional supplementation may be more effective at improving muscle mass and walking speed than an intervention only based on resistance training.

Pedometer-Based Behavioral Change Program Can Improve Dependency in Sedentary Older Adults: A Randomized Controlled Trial

BACKGROUND

Recent studies suggested that pedometer-based walking programs are applicable to older adults.

OBJECTIVES

The purpose of this study was to evaluate the use of pedometer in sedentary older adults to improve physical activity, fear of falling, physical performance, and leg muscle mass.

DESIGN

This was a pilot randomized controlled trial (RCT).

SETTING AND PARTICIPANTS

Eighty-seven community dwelling sedentary older adults living in Japan.

INTERVENTION

The intervention group (n=43) received a pedometer-based behavioural change program for 6 months, while the control group (n=44) did not. The participants in the intervention group were instructed to increase their mean daily steps by 10% each month. Thus, at the end of 6 months, participants in the intervention group were expected to have 77 % more daily steps than their baseline step counts. Written activity logs were monthly averaged to determine whether the participants were achieving their goal.

MEASUREMENTS

Outcome measures were physical activity, fear of falling, physical performances, and leg muscle mass.

RESULTS

In this 6-month trial 40 older adults (93%) completed the pedometer protocol with good adherence. In the intervention group, average daily steps were increased by 83.4% (from 20311323 to 3726 1607) during the study period, but not in the control group (from 20471698 to 22671837). The pedometer-based behavioral change program was more effective to improve their physical activity, fear of falling, locomotive function, and leg muscle mass than control (P<0.05).

CONCLUSION

These results suggested that the pedometer-based behavioral change program can effectively improve the physical activity, fear of falling, physical performance, and leg muscle mass in sedentary older adults.

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.

The relationship between the daily step counts and low back pain during pregnancy

PURPOSE

To investigate the relationship between the change of daily step counts and low back pain (LBP) during pregnancy. Materials and

METHODS

Pregnant women at less than eight weeks of gestation (WG) were recruited. Daily step counts were measured with a pedometer. To assess LBP, the Oswestry disability index (ODI) score was recorded. Thirty-six individuals were divided into the LBP and non-LBP groups. The effect of step counts on LBP between the two groups was analyzed.

RESULTS

At 16-19 WG, step counts were not considerably changed in the non-LBP group but were significantly increased in the LBP group. At 24-27 and 32-35 WG, step counts were increased in the non-LBP group but were significantly decreased in the LBP group.

CONCLUSIONS

Acute increase of daily step counts in early pregnancy is a risk for LBP, and gradual increases of step counts after mid-pregnancy is recommended for women.

Self-assessment of Rheumatoid Arthritis Disease Activity Using a Smartphone Application. Development and 3-month Feasibility Study

INTRODUCTION

This article is part of the Focus Theme of Methods of Information in Medicine on "Methodologies, Models and Algorithms for Patients Rehabilitation".

BACKGROUND

Rheumatoid arthritis (RA) is a progressive inflammatory disease that causes damage to multiple joints, decline in functional status, and premature mortality. Thus, effective and frequent objective assessments are necessary. Then, we developed a self-assessment system for RA patients based on a smartphone application.

OBJECTIVE

The purpose of this study was to investigate the feasibility of a self-assessment system for RA patients using a smartphone application.

METHODS

We measured daily disease activity in nine RA patients who used the smartphone application for a period of three months. A disease activity score (DAS28) predictive model was used and feedback comments relating to disease activity were shown to patients via the smartphone application each day. To assess participants' RA disease activity, the DAS28 based on the C-reactive protein level was measured by a rheumatologist during monthly clinical visits.

RESULTS

The disease activity measured by the application correlated well with the patients' actual disease activity during the 3-month period, as assessed by clinical examination. Furthermore, most participants gave favourable responses to a questionnaire administered at the end of the 3-month period containing questions relating to the ease of use and usefulness of the system.

CONCLUSIONS

The results of this feasibility study indicated that the DAS28 predictive model can longitudinally predict DAS28 and may be an acceptable and useful tool for assessment of RA disease activity for both patients and healthcare providers.

Effects of short-term gentle treadmill walking on subchondral bone in a rat model of instability-induced osteoarthritis

OBJECTIVE

Subchondral bone cyst (SBC) growth, caused by osteoclast activity during early knee osteoarthritis (OA) pathogenesis, should be treated to prevent further progressions of OA. In the present study, we evaluated the effects of gentle treadmill walking on subchondral bone and cartilage changes in an experimental rat model of destabilized medial meniscus (DMM).

METHOD

Twelve-week-old Wistar rats underwent DMM surgery in their right knee and sham surgery in their left knee and were assigned to either the sedentary group or walking group (n = 42/group). Animals in the walking group were subjected to treadmill exercise 2 days after surgery, which included walking for 12 m/min, 30 min/day, 5 days/week for 1, 2, and 4 week(s). Subchondral bone and cartilage changes were evaluated by micro-CT analysis, histological analysis, and biomechanical analysis.

RESULTS

Treadmill walking had a tendency to suppress SBC growth, which was confirmed by micro-CT (P = 0.06) and positive staining for tartrate-resistant acid phosphatase (TRAP) activity for the osteoclast number per bone surface (P = 0.09) 4 weeks after surgery. These changes coincide with the prevention of cartilage degeneration as evaluated by the Osteoarthritis Research Society International (OARSI) score (P < 0.05) and biomechanically softening (P < 0.05). Furthermore, treadmill walking could suppressed increasing osteocyte deaths (P < 0.01), which was positively correlated with the OARSI score (r = 0.77; P < 0.01).

CONCLUSION

These results indicate biomechanical and biological links exist between cartilage and subchondral bone; preventive effects of treadmill walking on subchondral bone deterioration might be partly explained by the chondroprotective effects.

Risk factors for elbow pain in Little League baseball players: a cross-sectional study focusing on developmental factors

AIM

The incidence of Little League elbow is increasing. However, the risk factors for Little League elbow, especially those related to development have not previously been investigated. The purpose of this study was to investigate the risk factors for elbow pain in Little League baseball players while focusing on the developmental factors.

METHODS

A total of 654 baseball players aged 6-12 years, all male, participated in this study. Participants completed an original questionnaire that included items assessing demographic data, developmental factors (increase in height and increase in weight over the preceding 12 months), and baseball-related factors. Multiple regression analysis was used to identify the risk factors for elbow pain during the 12 months prior to the study.

RESULTS

The data collected for 392 players without omissions or blank answers were submitted to statistical analysis. We found that 19.1% of Little League baseball players had experienced elbow pain in the 12 months leading up to the study. The analysis revealed that height (Odds Ratio [OR], 1.10; 95% confidence interval [95%CI], 1.03-1.17) and increase in height (OR, 1.16; 95%CI, 1.00-1.34) were risk factors that increased the risk of elbow pain after adjustment for demographic data, developmental data, and baseball-related factors.

CONCLUSION

Our results suggested that an increase over height in the last 12 months may predispose young baseball players to elbow pain.

Analysis of factors affecting time in therapeutic range control after warfarin administration

The protective efficacy of warfarin for cardiogenic cerebral embolism has been established. However, warfarin is generally administered to only approximately 35% of the atrial fibrillation patients who required warfarin therapy. It has been reported that international normalized ratio (INR) control was carried out appropriately in < 50% of such patients. Therefore, from the viewpoint of prevention of the onset and recurrence of embolism, the maintenance of a stable anticoagulant level is necessary. In warfarin therapy, in addition to INR control, time in therapeutic range (TTR) also markedly affects the efficacy of warfarin therapy. Therefore, we classified patients into two groups on the basis of the cutoff TTR ≥ 65% at which the inhibitory effect of warfarin on stroke has been observed. We aimed to examine the association between INR and TTR with the correction of the therapeutic efficacy of warfarin by analyzing the factors leading to poor TTR control. The most valuable finding of this study is that marked fluctuations of brain natriuretic peptide levels in patients with complication of heart failure was a risk factor for poor TTR control. Identification of the factors leading to the poor TTR control is useful for making the decision to switch to other anticoagulants, such as dabigatran or apixaban, or to continue warfarin by correcting risk factors in atrial fibrillation patients receiving long-term warfarin therapy.

A New Statistical Model Identified Two-thirds of Clinical T1 Gastric Cancers as Possible Candidates for Endoscopic Treatment

BACKGROUND

Clinical T1 gastric cancer has low metastatic potential to lymph nodes and is generally curable by local treatment. Endoscopic resection can preserve the whole stomach and does not impair the patient's quality of life; however, its indication is strictly limited to the subset of patients without nodal metastasis. The study was designed to predict reliably the patients without nodal metastasis based only on the clinical information.

METHODS

We examined patients with clinical T1 disease who were treated with surgery. The clinically available information was evaluated for its ability to predict nodal metastasis by logistic regression model. Then, the predictive ability of the logistic regression model using the risk factors for nodal metastasis was evaluated by a receiver operating characteristic curve.

RESULTS

A total of 511 patients were entered into this study. The clinical depth (cT1a or cT1b), maximal tumor diameter, and pathological type were confirmed to be significantly different between patients with and without nodal metastasis. The cutoff value of the tumor diameter differed depending on the histology and clinical depth: 79 mm for differentiated type and 48 mm for undifferentiated type in cT1a tumors, and 43 mm for differentiated type and 11 mm for undifferentiated type in cT1b tumors. According to these criteria, 348 of the 511 patients (68.1 %) were classified to have predictive N0 status. The negative predictive value was 95.7 % (95 % confidence interval 94.0-97.5 %).

CONCLUSIONS

The predictive criteria based on the multivariate logistic model identified that almost two-thirds of the patients with clinical T1 gastric cancer were possible candidates for endoscopic treatment.

Ambipolar organic field-effect transistors based on solution-processed single crystal microwires of a quinoidal oligothiophene derivative

A simple and versatile solution-processing method based on molecular self-assembly is used to fabricate organic single crystal microwires of a low bandgap quinoidal oligothiophene derivative. Individual single crystal microwire transistors present well-balanced ambipolar behaviour with hole and electron mobilities as high as 0.4 and 0.5 cm(2) V(-1) s(-1), respectively.

Development of age-specific Japanese head phantoms for dose evaluation in paediatric head CT examinations

In this study, the authors developed age-specific physical head phantoms simulating the physique of Japanese children for dose evaluation in paediatric head computed tomography (CT) examinations. Anatomical structures at 99 places in 0-, 0.5-, 1- and 3-y-old Japanese patients were measured using DICOM viewer software from CT images, and the head phantom of each age was designed. For trial manufacture, a 3-y-old head phantom consisting of acrylic resin and gypsum was produced by machine processing. Radiation doses for the head phantom were measured with radiophotoluminescence glass dosemeters and Si-pin photodiode dosemeters. To investigate whether the phantom shape was suitable for dose evaluation, organ doses in the same scan protocol were compared between the 3-y-old head and commercially available anthropomorphic phantoms having approximately the same head size. The doses of organs in both phantoms were equivalent. The authors' designed paediatric head phantom will be useful for dose evaluation in paediatric head CT examinations.

High-temperature-required protein A2 as a predictive marker for response to chemotherapy and prognosis in patients with high-grade serous ovarian cancers

Background:

High-temperature-required protein A2 (HtrA2), a protein relating with apoptosis in a caspases-dependent and non-dependent manner, has been reported to be associated with chemosensitivity in several human cancers.

Methods:

Tissue microarrays made from 142 patients with high-grade serous ovarian adenocarcinoma were evaluated to assess whether HtrA2 expression was related with several clinical parameters.

Results:

Negative HtrA2 expression was observed in 36 cases (25%) of the patients, and related with significantly lower response rates of primary chemotherapy than those with positive HtrA2 expression (56% vs 83%, P<0.01). In addition, negative HtrA2 expression was identified as an independent worse prognostic factor for progression-free survival and overall survival by multivariate analyses. Furthermore, HtrA2 downregulation modulated sensitivity to platinum in serous ovarian cancer cells in vitro.

Conclusions:

HtrA2 expression was a predictor for sensitivity to chemotherapy, and could be a candidate of molecular target in the treatment of high-grade serous ovarian cancers.

Recurrent severe acute hepatitis caused by hypereosinophilic syndrome associated with elevated serum immunoglobulin G4 levels

A 46-year-old male was admitted to our hospital with severe acute hepatitis, hypereosinophilia, and serum immunoglobulin G4 (IgG4) elevation. Plasma exchange was performed, and he was treated by prednisolone; however, his hepatitis recurred twice over the following twelve months. Transjuglar liver biopsy was performed at the third onset, which demonstrated extensive hepatocyte necrosis, congestion, and severe eosinophil infiltration. We diagnosed hypereosinophilic syndrome (HES)-related hepatitis. Although no cholangitis was detected by imaging and pathological diagnosis, IgG4-positive cells were detected in the liver and bone marrow. Furthermore, the elevation of serum IgG4 levels was associated with the eosinophil count and his clinical condition. After the addition of azathioprine to his treatment regimen, no reoccurrence was observed. IgG4-positive cells may have contributed to the severity and refractoriness of this recurrent acute HES-related hepatitis.

Three-dimensional reconstruction of rat knee joint using episcopic fluorescence image capture

OBJECTIVE

Development of the knee joint was morphologically investigated, and the process of cavitation was analyzed by using episcopic fluorescence image capture (EFIC) to create spatial and temporal three-dimensional (3D) reconstructions.

METHODS

Knee joints of Wister rat embryos between embryonic day (E)14 and E20 were investigated. Samples were sectioned and visualized using an EFIC. Then, two-dimensional image stacks were reconstructed using OsiriX software, and 3D reconstructions were generated using Amira software.

RESULTS

Cavitations of the knee joint were constructed from five divided portions. Cavity formation initiated at multiple sites at E17; among them, the femoropatellar cavity (FPC) was the first. Cavitations of the medial side preceded those of the lateral side. Each cavity connected at E20 when cavitations around the anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) were completed.

CONCLUSION

Cavity formation initiated from six portions. In each portion, development proceeded asymmetrically. These results concerning anatomical development of the knee joint using EFIC contribute to a better understanding of the structural feature of the knee joint.