Biological effects of stored platelet-rich plasma eye-drops in corneal wound healing

BACKGROUND/AIMS

This study aimed to assess the efficacy and sterility of stored platelet-rich plasma (PRP) eye-drops for corneal epithelial wound healing compared with those of autologous serum (AS) eye-drops.

METHODS

At our single institution, PRP and AS eye-drops were prepared using peripheral blood obtained from six healthy volunteers and stored at 4°C. Platelet and leucocyte counts and transforming growth factor (TGF)-β1, epidermal growth factor (EGF), and fibronectin levels were assessed during storage for up to 4 weeks. Sterility was assessed by culturing 4-week poststorage samples. PRP, AS, and phosphate-buffered saline (PBS) eye-drop efficacies were compared using corneal epithelial wound healing assays in vitro and in vivo and monitoring wound areas under a microscope every 3 hours.

RESULTS

Higher platelet and lower leucocyte counts were seen in PRP than in whole blood on the day of preparation. After storage, TGF-β1, EGF, and fibronectin levels were significantly higher in PRP than in AS eye-drops. In vitro and in vivo, PRP eye-drops used on the day of preparation significantly promoted corneal epithelial wound healing compared with PBS. Moreover, PRP eye-drops stored for 4 weeks significantly promoted corneal wound healing compared with PBS and AS eye-drops.

CONCLUSION

PRP eye-drops stored at 4°C for 4 weeks promoted corneal epithelial wound healing with higher levels of growth factors than those observed in AS eye-drops, while maintaining sterility, suggesting that this preparation satisfies the unmet medical needs in the treatment of refractory keratoconjunctival epithelial disorders.

The Accuracy of Ankle Eccentric Torque Control Explains Dynamic Postural Control During the Y-Balance Test

Background

The Y-Balance Test (YBT), especially the posteromedial (PM) reach direction (PM-YBT), is able to identify dynamic postural control deficits in those who have ankle instability. However, there still exists a need to understand how sensorimotor function at the ankle explains the performance during the PM-YBT.

Hypothesis/Purpose

The purpose of this study was to determine whether the ability to accurately control eccentric ankle torque explained PM-YBT performance. It was hypothesized that eccentric dorsiflexion/plantarflexion torque control would be positively related to the maximum reach distance (MRD) of PM-YBT.

Study Design

Cross-sectional study.

Methods

Twelve healthy subjects performed the PM-YBT, maximum voluntary isometric contractions (MVIC) for both dorsiflexion and plantarflexion muscle strength, and then the torque control testing of the ankle. The torque control testing provided a target torque level on a screen in front of the subject and passive rotations of the ankle joint in the sagittal plane at 10 deg/sec between plantarflexion to dorsiflexion. Subjects were then instructed to eccentrically contract the dorsiflexors and plantar flexors to generate torque while the ankle joint rotated. The accuracy of torque control during eccentric dorsiflexion and plantarflexion by calculating absolute errors, the area between the target torque and the produced torque were evaluated. Tibialis anterior and soleus muscle activities were simultaneously recorded during testing. A step-wise linear regression model was used to determine the best model predicted the MRD of the PM-YBT (PM-MRD).

Results

A step-wise linear regression developed a model explaining only eccentric dorsiflexion torque control predicted higher PM-MRD score (R2 = 44%, F1,10 = 7.94, β = -0.67, p = 0.02).

Conclusion

The accuracy of torque control during eccentric dorsiflexion predicts better performance in the PM-YBT.

Level of Evidence

3b.

Cross-cultural adaptation, validity, reliability and responsiveness of the Japanese version of the Victorian Institute of sports assessment for patellar tendinopathy (VISA-P-J)

BACKGROUND

This study aimed to translate, adapt, and test the psychometric properties of the Japanese version of the Victorian Institute of sports assessment for patellar tendinopathy (VISA-P-J).

METHODS

This prospective cohort study registered 43 participants ≥ 18 years old with a history of painful symptoms in the inferior pole of the patella to the proximal patellar tendon lasting ≥ 1 month for patellar tendinopathy. Pain in daily life and during sports activities, symptom classification, and patient global impression of change were assessed at the baseline, 1 week, and 12 weeks. The psychometric properties, test-retest reliability, standard error of measurement, internal consistency criterion validity, construct validity, responsiveness, and interpretability, of the VISA-P-J were calculated according to the COSMIN.

RESULTS

The two-way random-effects, absolute agreement intraclass correlation coefficient for test-retest reliability of VISA-P-J was 0.87 (95% confidence interval: 0.78, 0.93), and the standard error of measurement of VISA-P-J was 0.89. The Cronbach's alpha for internal consistency of VISA-P-J was 0.81. A correlation between VISA-P-J and Roel's classification, Visual Analog Scale for pain (VAS)-Active Daily Living, and VAS-Sports (r = - 0.52, r = - 0.66, r = - 0.86, p < 0.01, respectively) was observed for criterion validity. All hypotheses of the hypothesis-testing method to evaluate construct validity and responsiveness of VISA-P-J were substantiated. The minimal clinically important difference of VISA-P-J was 7 points.

CONCLUSION

We demonstrated that the VISA-P-J was a reliable, valid, and responsive assessment method for individuals with chronic pain in the patellar tendon.

Intra-Articular Injections of the Adipose-Derived Mesenchymal Stem Cells Suppress Progression of a Mouse Traumatic Knee Osteoarthritis Model

OBJECTIVE

This study aimed to determine whether the intra-articular injection of human adipose-derived mesenchymal stem cells (ADSCs) protects against the progression of murine post-traumatic osteoarthritis.

DESIGN

ADSCs were isolated from human abdomen or buttock adipose tissues. In in vitro study, ADSCs conditioned medium was added to human chondrocytes pre-treated with interleukin-1β (IL-1β), and resultant gene expression of target inflammatory genes was measured by real-time quantitative polymerase chain reaction. A mouse model of knee osteoarthritis was generated by unilaterally transecting the medial meniscus in the right hind limb of 20 female C57BL/6 mice. Mice were randomly assigned to 2 treatment groups that received 6 µl intra-articular injections of either phosphate-buffered saline (control) or 2 × 10⁴ cells/μl of ADSCs 14, 28, and 42 days post-surgery. Mice were euthanized 84 days post-surgery and histological and micro-computed tomography evaluation of knee joints were analyzed. Hind limb weight-bearing distribution was measured pre-surgery and 28 and 84 days post-surgery.

RESULTS

Conditioned medium from cultured human adipose-derived mesenchymal stem cells suppressed the expression of target inflammatory genes in chondrocytes pre-treated with IL-1β, suggesting anti-inflammatory properties (P < 0.01). Histological analyses indicated that the progression of destabilization of medial meniscus-induced knee osteoarthritis was suppressed by the administration of ADSCs compared with control group at medial femorotibial joint in vivo. This protective effect was related to a reduction in articular cartilage loss.

CONCLUSION

The intra-articular injection of ADSCs suppressed articular cartilage loss in a mouse model of knee osteoarthritis, possible through anti-inflammatory mechanisms.

Study protocol for a randomised placebo controlled trial of platelet-rich plasma injection to prevent post-traumatic knee osteoarthritis after anterior cruciate ligament reconstruction

INTRODUCTION

The elevated cytokine levels in patients suffering from anterior cruciate ligament (ACL) rupture may lead to acute post-traumatic arthritis (APTA) and post-traumatic osteoarthritis (PTOA). Due to its chondrogenerative and anti-inflammatory effect, platelet-rich plasma (PRP) therapy is expected to show a positive outcome in APTA and PTOA. The proposed trial aims to quantitatively measure the efficacy of PRP injection in arresting post-traumatic cartilage degeneration among patients after ACL reconstruction.

METHODS AND ANALYSIS

This will be a single-blind, randomised, prospective, controlled clinical trial designed following the Consolidated Standards of Reporting Trials guidelines. After ACL reconstruction, 80 patients will be randomised to receive either leucocyte-poor PRP injection after joint aspiration or a placebo control group receiving only joint aspiration. Participants (age 20-49 years) will be those who have undergone ACL reconstruction within the past 2 weeks with a body mass index<35 and Kellgren Lawrence osteoarthritis grade<2. The primary outcome will include MRI-T2 values of knee cartilage at 6 months. The secondary outcomes will include pain assessment by Visual Analogue Scale, Knee injury and Osteoarthritis Outcome Score, blood and urine test, physical findings, measurements for muscle strength and joint stability.

ETHICS AND DISSEMINATION

The study was approved by The Independent Ethics Committee for Clinical Trials of the Japanese Association for the Promotion of State-of-the-Art Medicine. Results of the trial and each of the outcomes will be shared via conferences and publication in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

jRCTb030200391.

Effect of low-intensity exercise with blood flow restriction during rest intervals on muscle function and perception

PURPOSE

We assessed the effects of low-intensity exercise with blood flow restriction (BFR) during rest intervals on recovery of muscle function and pain during exercise and rest intervals.

METHODS

Participants were 10 males, and study arms of the participants were randomly assigned into three conditions; low-intensity exercise with BFR during rest intervals (rBFR), low-intensity exercise with BFR during exercise (eBFR) and low-intensity exercise only (EO). The exercise task was elbow flexion until repetition failure at 30% of 1 RM, and cuff pressure was 120 mmHg. The maximum voluntary isometric contraction (MVIC) and the muscle endurance (ME) were measured pre, post, 1 h, 24 h and 48 h after the exercise. Pain during exercise and rest intervals were evaluated using Numerical Rating Scale.

RESULTS

MVIC and ME significantly decreased after exercise in all conditions. Pain during exercise was lower in rBFR (4.2 ± 2.9) (p = 0.007) and EO (4.4 ± 2.7) (p = 0.014) conditions compared to eBFR condition (6.7 ± 1.7), but the pain during rest intervals was more intense in rBFR condition (5.2 ± 1.6) compared to eBFR (1.5 ± 1.4) and EO (1.7 ± 1.2) conditions (all: p < 0.001).

CONCLUSION

We discovered that recovery of muscle function was the same as BFR during rest intervals and BFR during exercise. Also, our results suggested that BFR itself may cause the perception of pain. Future studies are thus required to investigate the optimal dosage focusing on the pressure volume and intensity used in BFR during intervals. This article is protected by copyright. All rights reserved.

Predictors of Effectiveness of Platelet-Rich Plasma Therapy for Knee Osteoarthritis: A Retrospective Cohort Study

There has recently been growing interest worldwide in biological therapies such as platelet-rich plasma injection for the treatment of knee osteoarthritis. However, predicting the effectiveness of platelet-rich plasma therapy remains uncertain. Therefore, this retrospective cohort study was performed to assess a range of predictors for the effectiveness of platelet-rich plasma therapy in treating knee osteoarthritis. The study included 517 consecutive patients who underwent three injections of leucocyte-poor platelet-rich plasma therapy from 2016 to 2019 at a single institution. The treatment outcomes, including patient-oriented outcomes (visual analogue scale score and Knee Injury and Osteoarthritis Outcome Score), were analyzed and compared according to the severity of knee osteoarthritis based on Kellgren–Lawrence (KL) grading using standing plain radiographs. Fisher’s exact test, univariate regression, and multivariate regression were used for data analysis. Patient-oriented outcomes were significantly improved 6 and 12 months after platelet-rich plasma therapy. The overall responder rate in patients who met the Outcome Measures in Rheumatology (OMERACT)–Osteoarthritis Research Society International (OARSI) responder criteria was 62.1%. The responder rate was significantly lower in patients with severe knee osteoarthritis (KL4, 50.9%) than in those with mild (KL2, 75.2%) and moderate (KL3, 66.5%) knee osteoarthritis. The multivariate logistic regression analysis revealed that deterioration of the knee osteoarthritis grade (increased KL grade) was a significant predictor of a worse clinical outcome (odds ratio, 0.58; 95% confidence interval, 0.45–0.75; p < 0.001). The relative risk for non-responders in severe (KL4) KOA was 2.1 (95% CI, 1.5–3.0) at 6 months and 2.3 (1.6–3.2) at 12 months compared with mild-to-moderate (KL2-3) KOA. The efficacy of platelet-rich plasma therapy was not affected by age, sex, body weight, or platelet count. This study revealed that the effectiveness of platelet-rich plasma therapy for the treatment of knee osteoarthritis is approximately 60% and that the effectiveness depends on the severity of knee osteoarthritis. This observation is useful not only for physicians but also for patients with knee osteoarthritis.

The immature platelet fraction affects the efficacy of platelet rich plasma therapy for knee osteoarthritis

Introduction

Platelet-rich plasma (PRP) therapy is used to treat pathological conditions such as degenerative inflammatory diseases including osteoarthritis (OA) by enhancing tissue repair and promoting anti-inflammatory effects. Although PRP therapy for patients with knee OA improved pain and functional scores, the association of clinical outcomes and quality of PRP including cell composition and concentration is unclear.

Methods

Therefore, this study analyzed blood cell counts, including the immature platelet fraction (IPF), in peripheral blood and PRP of 144 patients with knee OA who underwent PRP therapy. The mean leukocyte and platelet concentrations in whole blood and PRP were analyzed using an XN-1000 automated hematology analyzer. Visual analogue scale (VAS) scores and knee injury and osteoarthritis outcome scores (KOOS) before and 1 month after a single PRP injection were also determined.

Results

Higher platelet and lower leukocyte concentration rates were observed in PRP compared with whole blood. The platelet concentration in whole blood was negatively correlated with VAS improvement. The percentage of IPF (IPF%) in whole blood was positively correlated with VAS improvement and KOOS (pain) improvement, whereas the IPF% in PRP tended to correlate with VAS improvement. Furthermore, multivariate logistic regression demonstrated the high IPF% in whole blood was significantly associated with VAS improvement. The low percentage of neutrophil (neutrophil%) in PRP was significantly associated with the VAS improvement and KOOS (ADL) improvement.

Conclusions

Therefore, PRP efficacy for OA might depend on the patient's biological status.

•

High percentage of IPF (IPF%) in whole blood was significantly associated with VAS improvement.

•

Low neutrophil% in PRP was significantly associated with VAS improvement and KOOS (ADL) improvement.

•

The PRP efficacy for knee OA might depend on the patient's biological status.

Comparison of stress distribution in partially and completely edentulous mandibles around splinted and non-splinted implant prostheses: A finite element study

BACKGROUND

In some treatments using multiple dental implants, the implants are inserted in the bone with splinted or non-splinted implant prostheses. There are some reports about the influence of the splinted and non-splinted implants on stress distribution in the bone using the finite element method (FEM), and there is a controversy in the literature regarding whether the splinted or non-splinted implants prostheses reduce the stress generated on the implant-surrounding bone more efficiently. Additionally, the simple shape of the jaw bones with limited bone area was used for FEM analysis in many studies at the expense of accurate analysis.

OBJECTIVE

The aim of this study was to evaluate the difference in stress distribution in the bone between the splinted and non-splinted implants, and between completely and partially edentulous mandibles.

METHODS

The implants were inserted in the first premolar, second premolar, and first molar regions of the partial and complete mandibles, and the splinted and non-splinted crowns were attached to the implants. Vertical load (100 N) or oblique load (70 N, 30° from its long axis towards the lingual) was applied on the first premolar.

RESULTS

When vertical load was applied to the partially edentulous mandible model, the stress was concentrated intensively on the cortical bone around the first premolar regardless of whether splinted or non-splinted implants were used. On the other hand, the vertical load applied to the completely edentulous mandible model caused the stress to be concentrated intensively on the cortical bone around the first premolar with non-splinted implants. With respect to the oblique load, the stress was concentrated intensively on the cortical bone around the first premolar only with the non-splinted implants, in both the partial and complete mandibles.

CONCLUSION

This study shows the different stress distributions of the cortical bone around the implants between the partial and complete mandible. This indicates that the complete mandible should be used for the analysis of bone stress distribution around the implants using FEM.

Remnant preservation provides good clinical outcomes after anterior cruciate ligament reconstruction

PURPOSE

To evaluate the association of remnant preservation (RP) and non-RP (NRP) with patient-reported outcome measures and subsequent graft rupture at a minimum 2-year follow-up after anterior cruciate ligament (ACL) reconstruction.

METHODS

Patients in this retrospective study underwent primary isolated ACL reconstruction by the RP or NRP technique with a four- to five-strand hamstring tendon graft. Multivariate linear or logistic regression and Cox regression analyses were performed to compare the physical and psychological outcomes by the International Knee Documentation Committee subjective knee form (IKDC-SKF) and the Japanese Anterior Cruciate Ligament questionnaire 25 (JACL-25), respectively; satisfaction rate; and prognosticators of graft rupture.

RESULTS

In total, 120 patients (mean age, 30.6 ± 12.7 years; 54 RP, 66 NRP) with a mean follow-up of 3.2 ± 1.6 years were enrolled in this study. At the latest postoperative follow-up, the RP group showed a mean IKDC-SKF score of 92.3 ± 8.5 and mean JACL-25 score of 13.2 ± 11.2, while these scores in the NRP group were 86.4 ± 12.2 and 24.4 ± 19.5, respectively (P = 0.016 and 0.007, respectively). No significant differences were found in the return-to-sports rate (RP vs. NRP, 79.5% vs. 67.5%) or satisfaction rate (RP vs. NRP, 89.2% vs. 74.4%) (n.s.); however, a significant difference was found in the rate of return to the preinjury sports level (RP vs. NRP, 64.1% vs. 37.5%; P = 0.014). The graft rupture rate was significantly higher in the NRP than RP group (9/66 vs. 1/54; hazard ratio 9.29; 95% confidence interval 1.04-82.81). Younger age (≤ 18 years) was the other important risk factor for graft rupture (hazard ratio 8.67; 95% confidence interval 2.02-37.13).

CONCLUSION

Patients who underwent ACL reconstruction with the RP technique obtained somewhat better physical and psychological results than those who underwent ACL reconstruction with the NRP technique. With respect to clinical relevance, patients treated with the RP technique may obtain better outcomes in terms of graft rupture and return to the preinjury sports level than those treated with the NRP technique, but with no differences in overall return to sports or satisfaction.

LEVEL OF EVIDENCE

IV.

Reliability assessment of the functional movement screen for predicting injury risk in Japanese college soccer players

[Purpose] This study aimed to assess the reliability of the Functional Movement Screen and explore whether this evaluation tool can predict the risks of personal injuries in Japanese soccer players. [Participants and Methods] Seventy-five Japanese college soccer players who participated in our 1 year prospective cohort study underwent a Functional Movement Screen assessment. Demographic data, athletic characteristics, and types and frequency of injuries sustained, were analyzed with the assessment results. [Results] There was no significant difference in the mean Functional Movement Screen composite scores between genders. Although the Functional Movement Screen showed excellent inter-rater reliability (0.92), low overall internal consistency (0.35) was observed. A maximum score of 3 in straight leg raise occurred in 94% of the females and was considered a ceiling effect. None of the cut-off point scores of the Functional Movement Screen were associated with the number of overall injuries, lower limb injuries, and traumatic injuries, or time to return to play. The Functional Movement Screen composite score of ≤15 represented the maximum sensitivity of 76.92% and specificity of 34.78% with 0.56 in the area under the curve. [Conclusion] Functional Movement Screen composite scores do not have sufficient sensitivity and specificity for predicting injuries in Japanese college soccer players.

Quality comparison between two different types of platelet-rich plasma for knee osteoarthritis

Introduction: Knee osteoarthritis (KOA), the most common form of osteoarthritis (OA) is a considerable health concern worldwide. Platelet-rich plasma (PRP) is a common therapeutic option for KOA. Different types of PRPs have varying efficacies. However, a comparative analysis of the qualities of these PRPs is lacking. Methods: Two types of PRPs, including autologous protein solution (APS), and leukocyte-poor PRP (LP-PRP) along with whole blood (WB) and platelet-poor plasma (PPP) were characterized for platelet content, leukocyte content, and composition in 10 healthy volunteers (HV) (the controlled laboratory study) and 16 KOA patients (a retrospective observational study). Additionally, the levels of the platelet-derived growth factor (PDGF)-BB, and different cytokines were estimated in HV. Results: In HV, the concentrations of platelets and leukocytes, levels of different cytokines, including interleukin 1 receptor antagonist (IL-1Ra), soluble TNF receptor type II (sTNF-RII), and IL-1β, and the ratio of IL-1Ra/IL-1β were significantly higher in APS, whereas the PDGF-BB was higher in LP-PRP than APS. In KOA patients, a higher concentration of platelets was observed in LP-PRP, and a higher concentration of leukocytes was observed in APS than LP-PRP. Following the PAW classification system, LP-PRP was classified as P2-B type in HV (51.3 × 10⁴/μl) and KOA (53.4 × 10⁴/μl), whereas APS was classified as P3-A type in HV (110.1 × 10⁴/μl) and P2-A type in KOA (29.0 × 10⁴/μl). In a retrospective observational study, the KOA patients who underwent APS injection had a higher incidence of arthralgia, and this arthralgia lasted for a longer time than LP-PRP injection in the same individual. Discussion: The quality of the two PRPs differed distinctively depending on their preparation methods, which might affect their clinical efficacies and adverse events. Therefore, the characterization of these parameters should be prioritized while choosing PRP.

Platelet-rich plasma (PRP) accelerates murine patellar tendon healing through enhancement of angiogenesis and collagen synthesis

PURPOSE

Although platelet-rich plasma (PRP) therapy has become an increasingly popular treatment for sports-related injuries, the molecular mechanisms of PRP on tissue healing process remain poorly understood. The aim of the present study was to develop an experimental method quantifying the efficacy of PRP with murine patellar tendon injury model, leading to future elucidation of the mechanisms of PRP on healing processes.

METHODS

Full-thickness defects were created in the central third of the murine patellar tendon. The prepared allogenic PRP gel was applied on the defect of the patellar tendon (PRP group), while the remaining mice served as the untreated control group. Mice were sacrificed at 2, 4, 6, 8, and 10 weeks after the operation, with histological sections obtained in each time point (n = 4 / time point / group). Semi-quantitative histological evaluation was performed in accordance with the Bonar score. The variables included in this scoring system were cell morphology, ground substance, collagen arrangement, and vascularity, with higher grades indicating worse tendon structures. In addition, the ratio of the collagen fibers to the entire tendon tissue (FT ratio) was measured using KS400 software as a quantitative histological evaluation.

RESULTS

The total Bonar score in the PRP group was significantly lower than in control group. With regard to the variables in the Bonar score, the vascularity score was significantly higher in the PRP group at 2 and 4 weeks, while the collagen arrangement score was significantly lower in the PRP group at 8 weeks. Based on a quantitative evaluation, the recovery speed of the patellar tendon determined by FT ratio was significantly faster in the PRP group than in the control group at 6 and 8 weeks.

CONCLUSIONS

We have developed an experimental method for histological and quantitative evaluation of the effects of PRP on tissue healing using murine patellar tendon injury model. The results of this study suggest that the local application of PRP could enhance the tissue-healing process both directly through action on localized cells and indirectly through the recruitment of reparative cells through the blood flow. Further investigations will be needed to confirm the mechanisms of PRP in tissue-healing processes with the development of this experimental model.

Intra-articular Injection of Pure Platelet-Rich Plasma Is the Most Effective Treatment for Joint Pain by Modulating Synovial Inflammation and Calcitonin Gene-Related Peptide Expression in a Rat Arthritis Model

BACKGROUND

Platelet-rich plasma (PRP) has emerged as a treatment for osteoarthritis (OA). However, the effect that leukocyte concentrations in PRP have on OA remains unclear.

PURPOSE

To clarify the optimal PRP formulation for OA treatment by comparing pure PRP, leukocyte-poor PRP (LP-PRP), and leukocyte-rich PRP (LR-PRP) in a rat arthritis model.

STUDY DESIGN

Controlled laboratory study.

METHODS

Knee arthritis was induced bilaterally in male Wistar rats with intra-articular injections of monosodium iodoacetate (MIA) on day 0. Rats were randomly assigned to 1 of 3 treatment groups (pure PRP, LP-PRP, and LR-PRP). On day 1, allogenic PRP was injected into the right knee of rats and phosphate-buffered saline was injected into the left knee as a control. Weight distribution on the hindlimbs was measured for 14 days to assess pain behavior. Rats were euthanized at day 5 or 14 for histological assessment of synovial tissue and cartilage. Immunohistochemical staining of calcitonin gene-related peptide (CGRP) and α-smooth muscle actin was performed to determine the mechanism of pain relief induced by the PRP preparations.

RESULTS

In all groups, PRP increased the load-sharing ratio on PRP-injected knees, with pure PRP eliciting the largest effect among the 3 kinds of PRP (P < .05). Structural changes in the synovial tissue were significantly inhibited in the pure-PRP group compared with the control group after both 5 and 14 days (P < .001 and P = .025, respectively), whereas no significant difference was found between the control, LP-PRP, and LR-PRP groups. An inhibitory effect on cartilage degeneration was observed only in the pure-PRP group on day 14. Pure PRP also significantly inhibited expression of CGRP-positive nerve fibers in the infrapatellar fat pad compared with the other groups (P < .05).

CONCLUSION

In an MIA-induced arthritis model, pure PRP injection was the most effective treatment for reduction of pain-related behavior and inhibition of synovial inflammation and pain sensitization.

CLINICAL RELEVANCE

PRP formulations should be optimized for each specific disease. This study shows the superiority of pure PRP for treatment of arthritis and joint pain.

Platelet-rich plasma promotes recruitment of macrophages in the process of tendon healing

INTRODUCTION

Researchers have investigated the use of platelet-rich plasma (PRP) therapy. However, the mechanisms through which PRP affects tissue repair remain unclear. We hypothesize that PRP promotes tissue repair through not only via direct manner on the local cells but also via indirect manner that encourage the recruitment of reparative cells such as macrophages (MPs), and it depends on the quality of PRP including the concentration of leukocytes. The aim of this study is to elucidate the actions of the MPs in the mechanisms of PRP on tissue repair processes.

METHODS

Leukocyte-rich (LR) PRP and leukocyte-poor (LP) PRP were prepared from 12-week-old C57BL6 mice. Full-thickness defects were created in central third of patellar tendons of 12-week-old C57BL/6 mice for histologic analysis (n = 36) and 12-week-old B6.129P-Cx3cr1tm1Litt/J mice for flow cytometry analysis (n = 108). B6.129P-Cx3cr1tm1Litt/J mouse is GFP-positive only in the MP-linage cells thus MPs recruited to the repair tissue can be distinguished whether it had originated from administrated PRP or recruited from host mouse. Mice were treated either with LR-PRP, LP-PRP, or without PRP (control group). Histological analyses were performed to evaluate the tendon healing using Bonar score as semi-quantitative histological scoring system. Flow cytometric analyses were performed to count the number of GFP-positive cells around repaired patellar tendon. In addition, the ratio of pro-inflammatory MPs (M1)/anti-inflammatory MPs (M2) were analyzed in those GFP-positive cells. The statistical analysis was performed using GraphPad Prism ver6. P values < 0.05 were considered statistically significant.

RESULTS

In LR-PRP and LP-PRP groups, all variables in Bonar score such as cell morphology, cellularity, vascularity, and collagen arrangement were significantly improved in comparison with control group, indicating that both PRPs promote tendon hearing. LP-PRP promoted the tendon healing significantly faster than that of LR-PRP on postoperative day 28 (P < 0.001). LR-PRP enhanced angiogenesis (vascularity: P < 0.001), while LP-PRP improved the collagen arrangement on postoperative day 28 (collagen arrangement: P < 0.01). In other variables such as cell morphology and cellularity score, there were no significant differences between LR-PRP and LP-PRP groups in any time points. Flow cytometric findings showed that recruitment of GFP-positive MPs in the LR and LP-PRP groups were significantly increased from postoperative day 4 compared with control group without PRP treatment (P < 0.001). The majority of GFP-positive MPs were M1 at the initiation of tendon healing phase, and M2 were gradually increased from postoperative day 4. The number of M1 was significantly high both in the LP- and LR-PRP groups (day 4 and 7, p < 0.001), but the number of M2 was high only in the LP-PRP group (day 7 and 14, P < 0.05) when it compared with control group. The M1/M2 ratio on postoperative day 7 was significantly lower in the LP-PRP group than those in the control group (P < 0.05).

CONCLUSIONS

This study demonstrated that PRP enhanced the tendon healing and promoted the recruitment of MPs to the injured tissue. The subtypes of MPs were different depends on the types of PRPs, suggesting that leukocytes in PRP influence the effect of PRP therapy.

Reproducibility, responsiveness and validation of the Tampa Scale for Kinesiophobia in patients with ACL injuries

Background and purpose

Psychological factors including fear of pain, re-injury during movement (kinesiophbia) affect return-to-sport rates after anterior cruciate ligament (ACL) reconstructive surgery. Clinicians often encounter in the daily practice that athletes explain lack of self-confidence or psychological readiness during the sports activity. The Tampa Scale for Kinesiophobia (TSK) has been used to evaluate psychological outcomes in patients with ACL injuries in many countries and translated into Japanese version in 2013. However, no researchers validated its reliability, validity, and responsiveness of TSK for patients with ACL injury up to now. The purpose of this study was to evaluate the measurement properties of the Japanese version of the TSK (TSK-J) in patients with ACL injuries.

Study design

Cohort study (Diagnostic); Level of evidence, 2.

Methods

This prospective study was performed in the department of orthopaedic surgery at the university hospital of Juntendo from Sep 2016 and Apr 2017. Patients who diagnosed with ACL injury with or without reconstruction surgery completed several patient-reported outcome measures (PROMs) were included in this study. The COnsensus-based Standards for the selection of health status Measurement INstruments (COSMIN) guidelines were used to evaluate reliability, validity, responsiveness, and interpretability of the TSK-J.

Results

222 patients were included in this study. The TSK-J for ACL injured patients showed good internal consistency (Cronbach’s alpha = 0.79) and excellent test-retest reliability (intra-class correlation coefficient, ICC_2,1 = 0.90, 95% CI = 0.81 to 0.95). In addtion, the TSK-J was significantly but moderately correlated with the IKDC-SKF (r = − 0.49, P <0.001), VAS-Sports (r = − 0.48, P <0.001), and JACL-25 (r = 0.48, P <0.001). The effect size (ES) was small with the Cohen’s d = − 0.2. The minimal important difference (MID) was − 1.3 points. No significant TSK-J score change was observed over 1-year after ACL reconstruction (r = − 0.12, P <0.001). There were no floor or ceiling effects.

Conclusions

Our study demonstrated that the Japanese version of TSK has good reliability. However, its low validity and responsiveness indicate that it may not the best way to assess psychological factors for patients with ACL injury.

Appropriate management of high-flow priapism based on color Doppler ultrasonography findings in pediatric patients: four case reports and a review of the literature

INTRODUCTION

High-flow priapism in children is a very rare condition, and there is no clear consensus on its management. High-flow priapism is associated with increased cavernosal blood flow and broadly divided into two groups based on the presence or absence of arteriocavernous fistula in the corpora cavernosa.

OBJECTIVE

This study aimed to determine the appropriate management of high-flow priapism based on the existence of arteriocavernous fistula using penile color Doppler ultrasonography (CDU) findings in the pediatric population.

STUDY DESIGN

The cases of four boys aged between 6 and 11 years with high-flow priapism treated between 2009 and 2017 are reported. Two boys had prior perineal trauma, one boy had blunt penile glans trauma, and one had no obvious cause for the condition. All boys initially underwent penile CDU and were treated conservatively or via selective arterial embolization depending upon the presence or absence of an arteriocavernous fistula.

RESULTS

Penile CDU revealed an arteriocavernous fistula inside the corpus cavernosum penis in two of four boys and increased blood flow inside the corpus spongiosum in the remaining boys. The former two boys underwent selective arterial embolization and one boy underwent repeated embolization because of remaining arteriocavernous fistula feeding from the contralateral cavernosal artery, whereas the boys with no arteriocavernous fistula on CDU were managed conservatively. All boys were successfully treated within 1 month, and they had normal morning erection and no evidence of recurrent priapism at the follow-up.

DISCUSSION

Unlike low-flow priapism, high-flow priapism is not a medical emergency. Therefore, conservative therapy is an appropriate initial treatment, although selective arterial embolization can be effective for high-flow priapism with arteriocavernous fistula, with a success rate of 97% and no reported complications to date. Penile CDU is an imaging technique that can detect focal areas of turbulent flow with sensitivity close to 100%. This study has several limitations including a small number of cases, limited follow-up duration, and possibility of spontaneous arteriocavernous fistula closure in cases treated by arterial embolization.

CONCLUSION

Penile CDU could be a reliable tool to diagnose high-flow priapism and detect the presence or absence of arteriocavernous fistula. Although conservative therapy remains the first choice, selective arterial embolization may be an early treatment option when CDU reveals an arteriocavernous fistula.

Calcineurin inhibitors exacerbate coronary arteritis via the MyD88 signalling pathway in a murine model of Kawasaki disease

Calcineurin inhibitors (CNIs) have been used off-label for the treatment of refractory Kawasaki disease (KD). However, it remains unknown whether CNIs show protective effects against the development of coronary artery lesions in KD patients. To investigate the effects of CNIs on coronary arteries and the mechanisms of their actions on coronary arteritis in a mouse model of KD, we performed experiments with FK565, a ligand of nucleotide-binding oligomerization domain-containing protein 1 (NOD1) in wild-type, severe combined immunodeficiency (SCID), caspase-associated recruitment domain 9 (CARD9)^-/- and myeloid differentiation primary response gene 88 (MyD88)^-/- mice. We also performed in-vitro studies with vascular and monocytic cells and vascular tissues. A histopathological analysis showed that both cyclosporin A and tacrolimus exacerbated the NOD1-mediated coronary arteritis in a dose-dependent manner. Cyclosporin A induced the exacerbation of coronary arteritis in mice only in high doses, while tacrolimus exacerbated it within the therapeutic range in humans. Similar effects were obtained in SCID and CARD9^-/- mice but not in MyD88^-/- mice. CNIs enhanced the expression of adhesion molecules by endothelial cells and the cytokine secretion by monocytic cells in our KD model. These data indicated that both vascular and monocytic cells were involved in the exacerbation of coronary arteritis. Activation of MyD88-dependent inflammatory signals in both vascular cells and macrophages appears to contribute to their adverse effects. Particular attention should be paid to the development of coronary artery lesions when using CNIs to treat refractory KD.

Mid-trimester residual cervical length and the risk of preterm birth in pregnancies after abdominal radical trachelectomy: a retrospective analysis

OBJECTIVE

To investigate the association between mid-trimester residual cervical length (CL) and the risk of preterm birth in pregnancies after abdominal radical trachelectomy (RT).

DESIGN

Retrospective cohort study.

SETTING

University hospital.

POPULATION

A total of 33 deliveries after 22 weeks' gestation in 30 women who underwent abdominal RT including prophylactic cervical cerclage and perinatal care between January 2002 and May 2016.

METHODS

The association between mid-trimester residual CL (the distance between the cerclage and the external cervical os) and gestational age at delivery was investigated. Receiver-operating characteristics (ROC) curve analysis was performed to estimate the optimal cut-off values of the mid-trimester residual CL for the prediction of preterm birth.

MAIN OUTCOME MEASURES

Preterm birth before 34 weeks' gestation.

RESULTS

Mid-trimester residual CL showed a significant correlation with gestational age at delivery (r = 0.36, P < 0.05). There was a significant difference in residual CL between women who did and those who did not give birth before 34 weeks (P < 0.05). Mid-trimester residual CL < 13 mm was a good predictor of birth before 34 weeks, with a sensitivity of 67%, specificity of 75%, positive predictive value of 55% and negative predictive value of 86% (area under ROC curve, 0.75).

CONCLUSIONS

Mid-trimester residual CL is significantly correlated with gestational age at delivery. Residual CL assessment could be used to reassure physicians and women that there is only a small chance of preterm birth in pregnancies after abdominal RT.

TWEETABLE ABSTRACT

Mid-trimester residual cervical length is a good predictor of preterm birth after radical trachelectomy.

Kawasaki disease: a matter of innate immunity

Kawasaki disease (KD) is an acute systemic vasculitis of childhood that does not have a known cause or aetiology. The epidemiological features (existence of epidemics, community outbreaks and seasonality), unique age distribution and clinical symptoms and signs of KD suggest that the disease is caused by one or more infectious environmental triggers. However, KD is not transmitted person-to-person and does not occur in clusters within households, schools or nurseries. KD is a self-limited illness that is not associated with the production of autoantibodies or the deposition of immune complexes, and it rarely recurs. Regarding the underlying pathophysiology of KD, innate immune activity (the inflammasome) is believed to play a role in the development of KD vasculitis, based on the results of studies with animal models and the clinical and laboratory findings of KD patients. Animal studies have demonstrated that innate immune pathogen-associated molecular patterns (PAMPs) can cause vasculitis independently of acquired immunity and have provided valuable insights regarding the underlying mechanisms of this phenomenon. To validate this concept, we recently searched for KD-specific PAMPs and identified such molecules with high specificity and sensitivity. These molecules have structures similar to those of microbe-associated molecular patterns (MAMPs), as shown by liquid chromatography-tandem mass spectrometry. We propose herein that KD is an innate immune disorder resulting from the exposure of a genetically predisposed individual to microbe-derived innate immune stimulants and that it is not a typical infectious disease.

Leukocyte concentration and composition in platelet-rich plasma (PRP) influences the growth factor and protease concentrations

BACKGROUND

Platelet-rich plasma (PRP) therapy has become an increasingly popular treatment for orthopaedics and sports-related injuries, and various clinically available PRP preparation methods exist. However, the differences in PRP quality among numerous preparation methods remain unclear. Specifically, the benefit of including leukocytes in the PRP product remains controversial, and few studies have been conducted to evaluate the effects of the interaction between platelets and leukocytes on the growth factor concentrations. The aim of the present study was to compare the biological characteristics of PRPs focusing on the leukocyte concentration and composition.

METHODS

Leucocyte rich (LR)-PRP, leucocyte poor (LP)-PRP, and pure-PRP were prepared from the peripheral blood of 6 healthy male volunteers (mean age: 31.3 years). The concentrations of platelets, leukocytes, erythrocytes, growth factors (transforming growth factor-beta 1: TGF-β1; fibroblast growth factor-basic: FGF-b; platelet-derived growth factor-BB: PDGF-BB; vascular endothelial growth factor: VEGF) and matrix metalloproteinase-9 (MMP-9) from each of the PRP samples were measured. Considering the interaction between platelets and leukocytes, correlations between platelets/leukocytes and growth factors/MMP-9 were analyzed using partial correlation coefficients.

RESULTS

The platelet concentration did not differ among the three PRP preparation methods. Conversely, the leukocyte concentration was dramatically different: 14.9 ± 4.5 (10(3)/μl) in LR-PRP, 2.4 ± 1.3 (10(3)/μl) in LP-PRP, 0.2 ± 0.2 (10(3)/μl) in pure-PRP. The platelet concentration positively correlated with all growth factors. On the other hand, the leukocyte concentration positively correlated with PDGF-BB and the VEGF concentration, while it negatively correlated with FGF-b. Regarding catabolic factors, the MMP-9 concentration strongly correlated with the leukocyte concentration, while there was no correlation between the platelet and MMP-9 concentrations.

CONCLUSIONS

These findings demonstrate that leukocytes strongly influence the quality of PRPs. Therefore, modifying the PRP preparation method according to the pathology is essential to achieve better clinical results with PRP therapy.

Allele-specific PCR for a cost-effective & time-efficient diagnostic screening of spinal muscular atrophy

Background & objectives:

Genetic diagnosis of spinal muscular atrophy (SMA) is complicated by the presence of SMN2 gene as majority of SMA patients show absence or deletion of SMN1 gene. PCR may amplify both the genes non selectively in presence of high amount of DNA. We evaluated whether allele-specific PCR for diagnostic screening of SMA is reliable in the presence of high amount of genomic DNA, which is commonly used when performing diagnostic screening using restriction enzymes.

Methods:

A total of 126 blood DNA samples were tested in amounts ranging 80-200 ng, referred for the genetic diagnosis of SMA using both conventional PCR-RFLP and allele-specific PCR.

Results:

The results from both methods showed agreement. Further, allele-specific PCR was found to be a time-efficient and cost-effective method.

Interpretation & conclusions:

Our study demonstrated the accuracy of our allele-specific PCR and the results were comparable compatible with that of PCR-RFLP, indicating its practical application in SMA diagnostic screening.

Infectivity of HBV DNA positive donations identified in look-back studies in Hyogo-Prefecture, Japan

AIMS/OBJECTIVES

To clarify transfusion incidence of hepatitis B virus (HBV) infected blood negative for mini pool-nucleic acid amplification testing (MP-NAT).

BACKGROUND

Japanese Red Cross (JRC) blood centres screen donated blood to avoid contamination with HBV. However, a low copy number of HBV may be overlooked.

METHODS/MATERIALS

In Hyogo-Prefecture, JRC blood centres screened 787 695 donations for HBV from April 2005 to March 2009. Of these, 685 844 were donations from the repeat donors. To detect the donors with HBV, serological tests, MP-NAT and/or individual donation (ID)-NAT were performed. To detect the recipients with transfusion-transmitted HBV infection (TTHBI), serological analysis and/or ID-NAT were performed.

RESULTS

In this study, 265 of the 685 844 repeat donations were serologically and/or MP-NAT positive for HBV. Their repository samples from the previous donation were examined in a look-back study; 13 of the 265 repository samples proved ID-NAT positive. Twelve recipients were transfused with HBV-infected blood components derived from 10 of the 13 HBV-infected donors. Only 1 of the 12 recipients was identified as TTHBI case. Seven of the 12 recipients escaped from our follow-up study and 4 recipients were negative for HBV during the observation period.

CONCLUSION

On the basis of the look-back study among the repeat donors in Hyogo-Prefecture, Japan, donations with HBV-infected blood negative for MP-NAT occurred with a frequency of 13 in 685 844 donations (∼1/53 000 donations). However, more than half of the recipients transfused with HBV-infected blood negative for MP-NAT could not be followed up. It is necessary to establish a more cautious follow-up system.

Percutaneous transhepatic biliary drainage catheter tract recurrence in cholangiocarcinoma

BACKGROUND

The aim of the study was to clarify the incidence, risk factors and treatment of percutaneous transhepatic biliary drainage (PTBD) catheter tract recurrence in patients with resected cholangiocarcinoma.

METHODS

The medical records of 445 patients with perihilar and distal cholangiocarcinoma who underwent resection following PTBD were reviewed retrospectively.

RESULTS

PTBD catheter tract recurrence was detected in 23 patients (5.2 per cent). The mean(s.d.) interval between surgery and onset of the recurrence was 14.4(13.8) months. On multivariable analysis, duration of PTBD (60 days or more), multiple PTBD catheters and macroscopic papillary tumour type were identified as independent risk factors. In four patients with synchronous metastasis, the PTBD sinus tract was resected simultaneously, at the time of initial surgery. Of 19 patients with metachronous metastasis, 15 underwent surgical resection of the metastasis. Survival of the 23 patients with PTBD catheter tract recurrence was poorer than that of the 422 patients without recurrence (median 22.8 versus 27.3 months; P = 0.095). Even after surgical resection of PTBD catheter tract recurrence, survival was poor.

CONCLUSION

PTBD catheter tract recurrence is not unusual. The prognosis for these patients is generally poor, even after resection. To prevent this troublesome complication, endoscopic biliary drainage is first recommended when drainage is indicated.

Value of indocyanine green clearance of the future liver remnant in predicting outcome after resection for biliary cancer

BACKGROUND

It is difficult to predict hepatic functional reserve accurately before major hepatectomy. The aim of this study was to analyse the usefulness of the future liver remnant plasma clearance rate of indocyanine green (ICGK-F, calculated as plasma clearance rate of indocyanine green (ICGK) x proportion of the future liver remnant) in predicting death after major hepatectomy.

METHODS

Data on ICGK and ICGK-F were collected prospectively and analysed retrospectively for 274 patients who underwent right hepatectomy, right trisectionectomy or left trisectionectomy for biliary cancer between 1991 and 2008. The mortality rate and incidence of postoperative complications were analysed. Patients were separated into two groups according to year of operation (85 patients operated on between 1991 and 2000; 189 from 2001 to 2008).

RESULTS

In multiple logistic regression analyses, an ICGK-F less than 0.05 had the strongest impact on the incidence of postoperative mortality (odds ratio 8.06; P < 0.001). The postoperative mortality rate was significantly lower in the later period (P < 0.001). In patients with an ICGK-F value between 0.040 and 0.049, the mortality rate in the early period was 30 per cent, whereas it was only 8 per cent in the later period.

CONCLUSION

An ICGK-F of 0.05 is a useful cut-off value for predicting mortality and morbidity. With careful perioperative patient management in an experienced institution, this cut-off value can be lowered further.

Prevention by lansoprazole, a proton pump inhibitor, of indomethacin -induced small intestinal ulceration in rats through induction of heme oxygenase-1

The effect of lansoprazole, a proton pump inhibitor (PPI), on indomethacin-induced small intestinal ulceration was examined in rats, particularly in relation to heme oxygenase (HO)-1. The animals were administered indomethacin (10 mg/kg, p.o.) and killed 24 h later. Lansoprazole (30-100 mg/kg, p.o.) and omeprazole (30-100 mg/kg, p.o.) were given 30 min before the administration of indomethacin, while tin-protoporphyrin IX (SnPP: 30 mg/kg, i.v.), an inhibitor of HO-1, was injected 10 min before indomethacin or lansoprazole. Indomethacin produced hemorrhagic lesions in the small intestine, accompanied with an increase of mucosal invasion of enterobacteria, inducible nitric oxide synthase (iNOS) expression, and myeloperoxidase (MPO) activity in the mucosa. Pretreatment with lansoprazole dose- dependently reduced the severity of the indomethacin-induced intestinal lesions, with suppression of the increased MPO activity, while omeprazole had no effect. Pretreatment with SnPP significantly exacerbated these intestinal lesions and almost totally abolished the protective effect of lansoprazole. The up-regulation of iNOS mRNA expression following indomethacin was suppressed by lansoprazole in a SnPP-inhibitable manner, although the enhanced enterobacterial invasion remained unaffected. The amount of HO-1 protein in the intestinal mucosa was significantly increased by lansoprazole but not by omeprazole. Prior administration of carbon monoxide (CO)-releasing molecule-2 (CORM-2; 10 mg/kg, i.p.) significantly reduced the severity of these lesions and the enhancement of mucosal iNOS mRNA expression induced in the small intestine by indomethacin. These results suggest that lansoprazole prevents indomethacin-induced small intestinal ulceration, and this effect is associated with inhibition of iNOS expression, through up-regulation of HO-1/CO production in the mucosa.

The concept of perihilar cholangiocarcinoma is valid

BACKGROUND

The term perihilar cholangiocarcinoma has been used for all tumours involving or requiring resection of the hepatic confluence. However, it does not distinguish between intrahepatic and extrahepatic hilar tumours, and has no clinicopathological basis. This retrospective study examined whether the concept of perihilar cholangiocarcinoma is valid clinically.

METHODS

Some 250 patients with perihilar cholangiocarcinoma were divided into extrahepatic (EHC, 167 patients) and intrahepatic (IHC, 83) groups based on tumour location. Clinicopathological data were compared between these groups.

RESULTS

Liver, portal vein, venous and lymphatic invasion, and nodal metastasis were more common in IHCs than EHCs, whereas histological grade and incidence of perineural invasion were similar. IHCs were more advanced at the time of surgery; stage III or IV disease was found in 37.7 per cent of EHCs and 59 per cent of IHCs. Survival was marginally better for patients with EHCs than for those with IHCs (29.3 versus 20 per cent at 5 years; P = 0.057), but survival rates were similar for each tumour stage in the American Joint Committee on Cancer classification.

CONCLUSION

Combining EHC and IHC under the term perihilar cholangiocarcinoma is valid, as these tumours have comparable biological behaviour, with similar clinical management depending on stage and invasion.

Roles of nitric oxide (NO) and NO synthases in healing of dextran sulfate sodium-induced rat colitis

We examined the effects of various NO inhibitors on the healing of DSS-induced rat colitis. Experimental colitis was induced by feeding rats for 6 days with 2.5% DSS in drinking water. After DSS treatment, the animals were fed normally and killed various days up to 7 days later. L-NAME (a nonselective NOS inhibitor) or aminoguanidine (a selective iNOS inhibitor) was given p.o. twice daily for 6 days starting from the termination of DSS treatment. The area of lesions, colon length and MPO activity were measured on day 7 after DSS treatment. DSS treatment caused severe lesions in the colon, accompanied by an increase in MPO activity and a decrease in colon length. The lesions healed gradually after discontinuation of DSS treatment, with a histological restoration and subsidence of inflammation. The healing of DSS-induced colonic lesions was significantly impaired by daily administration of L-NAME or aminoguanidine, the effects being all but equivalent between these drugs, and the effect of L-NAME was significantly reverted by the co-administration of L-arginine. The expression of nNOS protein was observed in the colonic mucosa with or without DSS treatment, while those of iNOS and eNOS were markedly upregulated after DSS treatment. Likewise, the expression of VEGF was also up-regulated in the colon following DSS treatment, and this response was suppressed by both L-NAME and aminoguanidine. These results suggest that endogenous NO produced by mainly iNOS and partly eNOS contributes to the healing of DSS-induced colonic lesions, through the upregulation of VEGF expression and enhancement of angiogenesis.

Hypomutability at the polyadenine tract in SMN intron 3 shows the invariability of the a-SMN protein structure

Recently, the axonal-SMN (a-SMN) protein, which is generated by the gene responsible for spinal muscular atrophy (SMA), SMN, has been reported. Surprisingly, the a-SMN transcript includes the entire sequence of SMN intron 3. We had expected a high frequency of insertion/deletion mutations at a polyadenine tract in this intron, since simple repetitive sequence motifs are prone to mutations. Such mutations could change the C-terminal structure of the a-SMN protein. However, our study showed that almost all individuals, including healthy individuals, SMA patients and SMA-like patients, carried only alleles with a normal polyadenine tract. Hypomutability of the polyadenine tract in SMN intron 3 suggests the existence of transcriptional mechanisms preventing alterations to the open reading frame of axonal SMN and not allowing variability in the protein structure of a-SMN.

Non-steroidal anti-inflammatory drug-induced small intestinal damage is Toll-like receptor 4 dependent

BACKGROUND

Enterobacteria and cytokines both play roles in the pathophysiology of NSAID-induced enteropathy. Toll-like receptor (TLR) 4 recognises lipopolysaccharide (LPS), resulting in activation of an inflammatory cascade via the accessory protein MyD88.

AIMS

To investigate role of TLR4 in inflammatory responses in indomethacin-induced enteropathy.

METHODS

Indomethacin was administered p.o. to non-fasting rats and mice to induce small intestinal damage. The extent of such damage was evaluated by measuring the injured area stained dark blue with Evans blue. Rats were given antibiotics (ampicillin, aztreonam or vancomycin) p.o., or intraperitoneal LPS (a TLR4 ligand) or neutralising antibodies against neutrophils, tumour necrosis factor (TNF)-alpha, or monocyte chemotactic protein (MCP)-1. Furthermore, the intestinal ulcerogenicity of indomethacin was examined in TLR4-mutant, TLR4(-/-), and MyD88(-/-) mice.

RESULTS

Indomethacin induced small intestinal damage with an increase in expression of TNF-alpha and MCP-1 in both rats and mice. Antibodies against neutrophils, TNF-alpha and MCP-1 inhibited the damage by 83%, 67% and 63%, respectively, in rats. Ampicillin and aztreonam also inhibited this damage, and decreased the number of Gram-negative bacteria in the small intestinal contents of the rat. However, vancomycin, which exhibited no activity against Gram-negative bacteria, had no preventive effect against this damage. Administration of LPS 1 h after indomethacin aggravated the damage, whereas LPS pretreatment inhibited it with reduction of expression of TLR4 and cytokines. In TLR4-mutant mice, the damage and cytokine expression were markedly inhibited. TLR4(-/-) and MyD88(-/-) mice were also resistant to the damage.

CONCLUSIONS

Indomethacin may injure the small intestine through a TLR4/MyD88-dependent pathway.

Surgery for hilar cholangiocarcinoma: the Leeds experience

AIM

To review the experience with hilar cholangiocarcinoma and to determine the results of a radical surgical approach in a UK centre.

METHODS

A 10-year review of all patients treated surgically for proximal bile duct carcinoma at a single surgical unit was conducted. Patient demographics, disease details and histopathology reports were reviewed. From January 1993 through December 2003, 106 patients were admitted with the diagnosis of hilar cholangiocarcinoma and 61 patients received surgical exploration.

RESULTS

Tumours were staged as follows (UICC 6th edition): stage IB, n=10 IIA, n=9; IIB, n=20; III, n=8; IV, n=14. Out of 61 patients, 44 had a resection (3 bile duct resection alone, 41 liver resection with bile duct resection), 5 were considered unresectable and 12 underwent liver transplantation (LT). The caudate lobe was excised in 34 of the patients and regional lymphadenectomy was systematically carried out. Para-aortic lymphadenectomy was performed in 17 cases. Portal vein resection was needed in 17 and hepatic artery resection was performed in 4 cases. Negative histologic margins (R0) were achieved in 20 patients and microscopic margin involvement (R1) was seen in 16. In the remaining 8 resected patients, localised metastasis were found (peritoneal deposits in 2, liver metastasis in 4 and positive para-aortic lymph nodes in 2); nevertheless the resection was performed and it was considered R2. Overall survival at 3 and 5 years for patients who underwent a resection was 43% and 28% including postoperative deaths. The 1-, 3- and 5-year actuarial survival rates for patients who underwent R0 resection were 78%, 64% and 45% respectively, including the postoperative deaths (n=3). The median survival time was 41.1 months. The 1-, 3- and 5-year actuarial survival rates for R1 resection and R2 were 60%, 26%, 26% and 25% and 0% respectively, while the median survival time for these groups was 15.4 and 6.8 months respectively. The actuarial survival rate at 1, 3 and 5 years for well-differentiated tumours (G1) was 73%, 54% and 40% (median 39.7 months). The figures for G2 were 60%, 48% and 0%. The figures for G3 (poorly differentiated) were 16% and 0% at three years (p=0.03).The overall survival at 3 and 5 years for those patients who had a liver transplant was 41% and 20% including early postoperative mortality. The tumour grading (presence of poorly differentiated tumour) was found to be the only independent factor affecting the survival time producing a hazard ratio of 4.3 (p=0.0034, 95% confidence interval 0.1007-6.342).

CONCLUSIONS

Radical surgical resection is the best treatment for hilar cholangiocarcinoma. R0 resection provides acceptable 5-year survival, but R1 resection may also provide acceptable palliation. In our experience TNM stage and tumour grade were the main determinants of long-term survival.

Surgery for hilar cholangiocarcinoma: the Leeds experience

AIM

To review the experience with hilar cholangiocarcinoma and to determine the results of a radical surgical approach in a UK centre.

METHODS

A 10-year review of all patients treated surgically for proximal bile duct carcinoma at a single surgical unit was conducted. Patient demographics, disease details and histopathology reports were reviewed. From January 1993 through December 2003, 106 patients were admitted with the diagnosis of hilar cholangiocarcinoma and 61 patients received surgical exploration.

RESULTS

Tumours were staged as follows (UICC 6th edition): stage IB, n=10 IIA, n=9; IIB, n=20; III, n=8; IV, n=14. Out of 61 patients, 44 had a resection (3 bile duct resection alone, 41 liver resection with bile duct resection), 5 were considered unresectable and 12 underwent liver transplantation (LT). The caudate lobe was excised in 34 of the patients and regional lymphadenectomy was systematically carried out. Para-aortic lymphadenectomy was performed in 17 cases. Portal vein resection was needed in 17 and hepatic artery resection was performed in 4 cases. Negative histologic margins (R0) were achieved in 20 patients and microscopic margin involvement (R1) was seen in 16. In the remaining 8 resected patients, localised metastasis were found (peritoneal deposits in 2, liver metastasis in 4 and positive para-aortic lymph nodes in 2); nevertheless the resection was performed and it was considered R2. Overall survival at 3 and 5 years for patients who underwent a resection was 43% and 28% including postoperative deaths. The 1-, 3- and 5-year actuarial survival rates for patients who underwent R0 resection were 78%, 64% and 45% respectively, including the postoperative deaths (n=3). The median survival time was 41.1 months. The 1-, 3- and 5-year actuarial survival rates for R1 resection and R2 were 60%, 26%, 26% and 25% and 0% respectively, while the median survival time for these groups was 15.4 and 6.8 months respectively. The actuarial survival rate at 1, 3 and 5 years for well-differentiated tumours (G1) was 73%, 54% and 40% (median 39.7 months). The figures for G2 were 60%, 48% and 0%. The figures for G3 (poorly differentiated) were 16% and 0% at three years (p=0.03).The overall survival at 3 and 5 years for those patients who had a liver transplant was 41% and 20% including early postoperative mortality. The tumour grading (presence of poorly differentiated tumour) was found to be the only independent factor affecting the survival time producing a hazard ratio of 4.3 (p=0.0034, 95% confidence interval 0.1007-6.342).

CONCLUSIONS

Radical surgical resection is the best treatment for hilar cholangiocarcinoma. R0 resection provides acceptable 5-year survival, but R1 resection may also provide acceptable palliation. In our experience TNM stage and tumour grade were the main determinants of long-term survival.

Involvement of prostaglandin E receptor EP3 subtype and prostacyclin IP receptor in decreased acid response in damaged stomach

We investigated the roles of cyclooxygenase (COX) isozymes and prostaglandin E (PGE) receptor EP1 and EP3 subtypes or prostacyclin IP receptors in the decrease in acid secretion in the damaged mouse stomach. Male C57/BL6 mice, both wild type and animals lacking EP1, EP3, or IP receptors, were used after 18 h of fasting. Under urethane anesthesia, the stomach was mounted on an ex-vivo chamber and perfused with saline, and acid secretion as well as transmucosal potential difference (PD) was measured before and after exposure to 20 mM taurocholate Na (TC) for 20 min. Indomethacin, SC-560 or rofecoxib was given i.d. 30 min before TC. Mucosal exposure to TC in wild-type mice caused a reduction in PD, followed by decrease in acid secretion. Indomethacin attenuated the decrease in acid secretion after exposure to TC in wild-type mice, an effect mimicked by SC-560 but not rofecoxib, yet none of these drugs affected the decrease in PD. An altered acid response after exposure to TC was similarly observed in EP1 (-/-) mice but mitigated in mice lacking either EP3 or IP receptors, although a decrease in PD was observed in all groups. Furthermore, the decreased acid response was also attenuated by prior administration of the EP3- but not EP1- antagonist. Mucosal levels of PGE(2) and 6-keto PGF(1a) increased after exposure to TC in all groups of mice. In conclusion, the decrease in acid secretion in the damaged stomach is mediated by endogenous PGs derived from COX-1, through PGE(2)/EP3 receptors and prostacyclin/IP receptors.

Outcome following repeat liver resection for colorectal liver metastases

AIM

Our aim was to determine independent predictors of survival after second liver resection and to confirm whether the type of first resection influences survival after repeat resection.

METHODS

Fifty-four patients who underwent a second liver resection for colorectal liver metastases were analyzed. To find independent predictors of survival, possible prognostic factors regarding the primary tumor, and the first and second resections were used in the Cox regression analysis.

RESULTS

There were three postoperative deaths within 90 days of surgery. The 3- and 5-year overall survival rates were 53% and 46%, respectively. The size of the tumor (>50mm) (p=0.005), serum carcinoembryonic antigen level (>30microg/L) (p=0.002), and the presence of a positive surgical margin at the second resection (p=0.006) were independent predictors of poor survival following the second resection. The type of first resection was not associated with survival but was associated with the ability to achieve a histological negative surgical margin at the second liver resection (p=0.01).

CONCLUSION

Three independent predictors of survival were identified. Major initial liver resection was associated with a reduced ability to achieve surgical clearance at the second resection. For colorectal liver metastases, major resection should only be performed if a negative margin cannot be achieved by minor resection.

Intrahepatic cholangiojejunostomy following hepatobiliary resection

Background

Although intrahepatic cholangiojejunostomy is technically difficult, with recent improvements in surgery it should be possible to perform the anastomosis safely. The aim of this study was to evaluate the incidence of anastomotic leak after intrahepatic cholangiojejunostomy and to identify risk factors for such leakage.

Methods

Intrahepatic cholangiojejunostomy was performed in 423 patients undergoing hepatobiliary resection between January 1991 and December 2005. Anastomotic leak was proven radiographically by leakage from the anastomosis of contrast medium introduced via a biliary drainage tube placed during surgery.

Results

Anastomotic leak occurred in 27 patients (6·4 per cent), and was not related to the number of bile ducts reconstructed. The leak rate decreased significantly from 9·5 per cent (19 of 199) in the first 10 years to 3·6 per cent (eight of 224) in the last 5 years. Anastomotic leak was often followed by infections such as wound infection, intra-abdominal abscess and bacteraemia. Multivariable analysis identified age and intraoperative blood loss as independent risk factors for anastomotic leak. All leaks were treated by maintaining a prophylactically placed drain near the cholangiojejunostomy; neither repeat laparotomy nor percutaneous transhepatic biliary drainage was required.

Conclusion

Although demanding, intrahepatic cholangiojejunostomy can be performed successfully with a relatively low failure rate. Routine use of prophylactic drains and anastomotic stenting allows safe management of anastomotic leak with conservative therapy.

Isolation and characterization of mammalian D-aspartyl endopeptidase

The accumulation of D-isomers of aspartic acid (D-Asp) in proteins during aging has been implicated in the pathogenesis of Alzheimer's disease (AD), cataracts and arteriosclerosis. Here, we identified a specific lactacystin-sensitive endopeptidase that cleaves the D-Asp-containing protein and named it D-aspartyl endopeptidase (DAEP). DAEP has a multi-complex structure (MW: 600 kDa) and is localized in the inner mitochondrial membrane. However, DAEP activity was not detected in E. coli, S. cerevisiae, and C. elegans. A specific inhibitor for DAEP, i-DAEP: (benzoyl-L-Arg-L-His-[D-Asp]-CH(2)Cl; MW: 563.01), was newly synthesized and inhibited DAEP activity (IC(50), 3 microM), a factor of ten greater than lactacystin on DAEP. On the other hand, i-DAEP did not inhibit either the 20S or 26S proteasome. And we identified succinate dehydrogenase and glutamate dehydrogenase 1 as components of DAEP by affinity label using biotinylated i-DAEP. In the long life span of mammals, DAEP may serve as a scavenger against accumulation of racemized proteins in aging. Insights into DAEP will provide the foundation for developing treatments of diseases, such as AD, in which accumulation of D-Asp-containing proteins are implicated.

Effects of perinatal stress on the anxiety‐related behavior of the adolescence mouse

We evaluated the effects of sound noise or forced swim stress applied to pregnant mice or to neonatal mice on the anxiety-related behavior using the elevated plus-maze test performed during the age of 5 weeks. The forced swim stress applied at the late gestation period, days 10-18 of pregnancy, caused a significant reduction of the body weight gain of the dams. However, the anxiety-related behavior of the male and female offspring were not affected by the antenatal stress treatment. When the forced swim stress was applied to the neonatal mice during the late lactation period, 14-18 days after birth, the male mice showed an elevated level of anxiolytic behavior accompanying the reduction of the emotion-related motor activity. The anxiety-related behavior of the female mice was not affected by the stress treatment. Furthermore, we applied the sound noise or forced swim stress to the neonatal mice immediately after the weaning, 21-25 days after birth. The stress applied after the weaning period had no effect on the anxiety-related behavior. These results suggested that the stress applied during the lactation period, but not that during the antenatal period, nor after the weaning period, might have gender-dependently reduced the anxiety level of the male mouse. It was shown that the effects of perinatal stress on the anxiety-related behavior of the adolescent mouse varied according to the period of application and gender. The hypothesis that gender-dependent abnormalities in neurodevelopment might be caused by the excess stress applied to the breast-fed infant is of importance in elucidating the relationship between the psychoneurotic disorder in childhood and the environment stress of the breast-fed infant.