In vivo study on the repair of rat Achilles tendon injury treated with non-thermal atmospheric-pressure helium microplasma jet

Non-thermal atmospheric-pressure plasma (NTAPP) has been widely studied for clinical applications, e.g., disinfection, wound healing, cancer therapy, hemostasis, and bone regeneration. It is being revealed that the physical and chemical actions of plasma have enabled these clinical applications. Based on our previous report regarding plasma-stimulated bone regeneration, this study focused on Achilles tendon repair by NTAPP. This is the first study to reveal that exposure to NTAPP can accelerate Achilles tendon repair using a well-established Achilles tendon injury rat model. Histological evaluation using the Stoll's and histological scores showed a significant improvement at 2 and 4 weeks, with type I collagen content being substantial at the early time point of 2 weeks post-surgery. Notably, the replacement of type III collagen with type I collagen occurred more frequently in the plasma-treated groups at the early stage of repair. Tensile strength test results showed that the maximum breaking strength in the plasma-treated group at two weeks was significantly higher than that in the untreated group. Overall, our results indicate that a single event of NTAPP treatment during the surgery can contribute to an early recovery of an injured tendon.

Deep learning-based screening tool for rotator cuff tears on shoulder radiography

BACKGROUND

Early diagnosis of rotator cuff tears is essential for appropriate and timely treatment. Although radiography is the most used technique in clinical practice, it is difficult to accurately rule out rotator cuff tears as an initial imaging diagnostic modality. Deep learning-based artificial intelligence has recently been applied in medicine, especially diagnostic imaging. This study aimed to develop a deep learning algorithm as a screening tool for rotator cuff tears based on radiography.

METHODS

We used 2803 shoulder radiographs of the true anteroposterior view to develop the deep learning algorithm. Radiographs were labeled 0 and 1 as intact or low-grade partial-thickness rotator cuff tears and high-grade partial or full-thickness rotator cuff tears, respectively. The diagnosis of rotator cuff tears was determined based on arthroscopic findings. The diagnostic performance of the deep learning algorithm was assessed by calculating the area under the curve (AUC), sensitivity, negative predictive value (NPV), and negative likelihood ratio (LR-) of test datasets with a cutoff value of expected high sensitivity determination based on validation datasets. Furthermore, the diagnostic performance for each rotator cuff tear size was evaluated.

RESULTS

The AUC, sensitivity, NPV, and LR- with expected high sensitivity determination were 0.82, 84/92 (91.3%), 102/110 (92.7%), and 0.16, respectively. The sensitivity, NPV, and LR- for full-thickness rotator cuff tears were 69/73 (94.5%), 102/106 (96.2%), and 0.10, respectively, while the diagnostic performance for partial-thickness rotator cuff tears was low at 15/19 (78.9%), NPV of 102/106 (96.2%) and LR- of 0.39.

CONCLUSIONS

Our algorithm had a high diagnostic performance for full-thickness rotator cuff tears. The deep learning algorithm based on shoulder radiography helps screen rotator cuff tears by setting an appropriate cutoff value.

LEVEL OF EVIDENCE

Level III: Diagnostic Study.

Comparison of cost, surgical time, and clinical results between arthroscopic transosseous rotator cuff repair with lateral cortical augmentation and arthroscopic transosseous equivalent suture bridge: A propensity score-matched analysis

BACKGROUND

To reduce the healthcare burden, the clinical results of arthroscopic rotator cuff repair and the cost of the implants used have recently been focused upon. This study compared implant cost, surgical time, short-term clinical results, and cuff repair integrity 2 years postoperatively between arthroscopic transosseous rotator cuff repair using lateral cortical augmentation (TOA) and arthroscopic transosseous-equivalent suture bridge (TOE).

METHODS

This study included 220 patients with rotator cuff repairs performed by a single surgeon between December 2013 and December 2018. Overall, 70 TOA and 68 TOE cases met the inclusion criteria. The same surgeon performed the procedures at two different hospitals, and the techniques differed between the facilities. A total of 42 TOA patients were matched with 42 TOE patients. The patients were matched using a propensity score analysis by gender, age, and cuff tear size. The minimum follow-up period was 2 years. Implant cost and surgical time were compared between the two methods. The range of motion, clinical outcomes, and visual analog scale were evaluated. Magnetic resonance imaging was performed to examine cuff repair integrity 2 years postoperatively.

RESULTS

The follow-up rate was 81% (112/138 patients). Implant cost was significantly lower with TOA ($1,396 vs. $2,165; p < 0.001) than with TOE. The average surgical time in the TOA method was significantly shorter than that in the TOE method (82 vs. 109 min; p = 0.001). At a minimum 2-year follow-up, the mean active elevation, abduction, and clinical outcomes improved with both methods, although no improvements in external and internal rotations were observed with either method. There were no significant differences in the postoperative variables and retear rate (TOA, 12%; TOE, 19%; p = 0.548) between the two methods.

CONCLUSIONS

TOA and TOE achieved comparable clinical results; however, TOA was more cost-effective and had a shorter surgical time than TOE.

LEVEL OF EVIDENCE

Level Ⅲ, retrospective matched control study.

Comparison of short-term clinical outcomes and radiographic changes in Grammont reverse shoulder arthroplasty between the French and Japanese populations: A propensity score-matched analysis

BACKGROUND

Although Grammont-style reverse total shoulder arthroplasty (RSA) showed excellent clinical results in Europe, its utility for Asian populations remains unclear. This study aimed to compare the French and Japanese populations in terms of range of motion (ROM), functional outcomes, and scapular notching rates in patients who underwent standard Grammont-style RSA. We hypothesized that RSA for the Japanese population may not provide as good ROM and functional results at the final follow-up as that for the French population.

METHODS

A total of 25 Japanese patients undergoing RSA were propensity score matched to 25 French patients undergoing RSA. The patients were matched for four different covariates using a propensity score analysis. The minimum follow-up period was 2 years. We investigated differences between the populations with respect to body size and shoulder joint ROM and Constant score (CS) measured preoperatively and at the final follow-up. Scapular notching was examined using radiographs at the final follow-up.

RESULTS

The average height and weight of the French and Japanese patients were 164 cm and 70 kg and 152 cm and 56 kg, respectively. Anterior elevation (AE), external rotation (ER) at the side, internal rotation (IR), and CS total changed from 101° to 145°, 17° to 15°, 4.5 points to 5.5 points, and 36 points to 72 points, respectively, in the French population and from 63° to 119°, 8.5° to 13°, 4.6 points to 4 points, and 28 points to 58 points, respectively, in the Japanese population. AE improved in both the groups; ER and IR remained unchanged before and after surgery. The frequency of scapular notching (>grade 1) was higher in the Japanese population (56%) than in the French population (20%) (p = 0.019).

CONCLUSIONS

Grammont-style RSA improved AE and CS in both the populations, but AE and CS were significantly higher in the French population than in the Japanese population at the final follow-up. Scapular notching frequently occurs in the Japanese population.

Effects of empagliflozin on progression of chronic kidney disease: a prespecified secondary analysis from the empa-kidney trial

BACKGROUND

Sodium-glucose co-transporter-2 (SGLT2) inhibitors reduce progression of chronic kidney disease and the risk of cardiovascular morbidity and mortality in a wide range of patients. However, their effects on kidney disease progression in some patients with chronic kidney disease are unclear because few clinical kidney outcomes occurred among such patients in the completed trials. In particular, some guidelines stratify their level of recommendation about who should be treated with SGLT2 inhibitors based on diabetes status and albuminuria. We aimed to assess the effects of empagliflozin on progression of chronic kidney disease both overall and among specific types of participants in the EMPA-KIDNEY trial.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA), and included individuals aged 18 years or older with an estimated glomerular filtration rate (eGFR) of 20 to less than 45 mL/min per 1·73 m2, or with an eGFR of 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher. We explored the effects of 10 mg oral empagliflozin once daily versus placebo on the annualised rate of change in estimated glomerular filtration rate (eGFR slope), a tertiary outcome. We studied the acute slope (from randomisation to 2 months) and chronic slope (from 2 months onwards) separately, using shared parameter models to estimate the latter. Analyses were done in all randomly assigned participants by intention to treat. EMPA-KIDNEY is registered at ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and then followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroups of eGFR included 2282 (34·5%) participants with an eGFR of less than 30 mL/min per 1·73 m2, 2928 (44·3%) with an eGFR of 30 to less than 45 mL/min per 1·73 m2, and 1399 (21·2%) with an eGFR 45 mL/min per 1·73 m2 or higher. Prespecified subgroups of uACR included 1328 (20·1%) with a uACR of less than 30 mg/g, 1864 (28·2%) with a uACR of 30 to 300 mg/g, and 3417 (51·7%) with a uACR of more than 300 mg/g. Overall, allocation to empagliflozin caused an acute 2·12 mL/min per 1·73 m2 (95% CI 1·83-2·41) reduction in eGFR, equivalent to a 6% (5-6) dip in the first 2 months. After this, it halved the chronic slope from -2·75 to -1·37 mL/min per 1·73 m2 per year (relative difference 50%, 95% CI 42-58). The absolute and relative benefits of empagliflozin on the magnitude of the chronic slope varied significantly depending on diabetes status and baseline levels of eGFR and uACR. In particular, the absolute difference in chronic slopes was lower in patients with lower baseline uACR, but because this group progressed more slowly than those with higher uACR, this translated to a larger relative difference in chronic slopes in this group (86% [36-136] reduction in the chronic slope among those with baseline uACR <30 mg/g compared with a 29% [19-38] reduction for those with baseline uACR ≥2000 mg/g; ptrend<0·0001).

INTERPRETATION

Empagliflozin slowed the rate of progression of chronic kidney disease among all types of participant in the EMPA-KIDNEY trial, including those with little albuminuria. Albuminuria alone should not be used to determine whether to treat with an SGLT2 inhibitor.

FUNDING

Boehringer Ingelheim and Eli Lilly.

Impact of constrained humeral liner on impingement-free range of motion and impingement type in reverse shoulder arthroplasty using a computer simulation

BACKGROUND

Dislocation is a major complication of reverse total shoulder arthroplasty (RSA). The humeral liner may be changed to a constrained type when stability does not improve by increasing glenosphere size or lateralization with implants, and patients, particularly women with obesity, have risks of periprosthetic instability that may be secondary to hinge adduction on the thorax, but there are few reports on its impact on the range of motion (ROM). This study aimed to determine the influence of humeral liner constraint on impingement-free ROM and impingement type using an RSA computer simulation model.

METHODS

A virtual simulation model was created using 3D measurement software for conducting a simulation study. This study included 25 patients with rotator cuff tears and rotator cuff tear arthropathy. Impingement-free ROM and impingement patterns were measured during flexion, extension, abduction, adduction, external rotation, and internal rotation. Twenty-five cases with a total of 4 patterns of 2 multiplied by 2, making a total of 100 simulations: glenosphere (38 mm normal type vs. lateralized type) and humeral liner constraint (normal type vs. constrained type). There were 4 combinations: normal glenosphere and normal humeral liner, normal glenosphere and constrained humeral liner, lateralized glenosphere and normal humeral liner, and lateralized glenosphere and constrained humeral liner.

RESULTS

Significant differences were found in all impingement-free ROM in 1-way analysis of variance (abduction: P = .01, adduction: P < .01, flexion: P = .01, extension: P = .02, external rotation: P < .01, and internal rotation: P < .01). Tukey's post hoc tests showed that the impingement-free ROM was reduced during abduction, external rotation, and internal rotation with the combination of the normal glenosphere and constrained humeral liner compared with the other combinations, and improved by glenoid lateralization compared with the combination of the lateralized glenosphere and constrained humeral liner. In the impingement pattern, the Pearson χ2 test showed significantly greater proportion of impingement of the humeral liner into the superior part of the glenoid neck in abduction occurring in the combination of the normal glenosphere and constrained humeral liner group compared with the other groups (P < .01). Bonferroni post hoc tests revealed that the combination of the normal glenosphere and constrained humeral liner was significantly different from that of the lateralized glenosphere and constrained humeral liner (P < .01). Using constrained liners resulted in early impingement on the superior part of the glenoid neck in the normal glenosphere, whereas glenoid lateralization increased impingement-free ROM.

CONCLUSION

This RSA computer simulation model demonstrated that constrained humeral liners led to decreased impingement-free ROM. However, using the lateralized glenosphere improved abduction ROM.

Bone mineral density around cementless short stems after reverse shoulder arthroplasty: changes over time and its relationship to stem positioning

Background

There are numerous reports of bone adaptation observed on plain radiography studies after the use of cementless short stems in reverse shoulder arthroplasty. However, reports on changes in bone mineral density (BMD) around the stem using dual-energy X-ray absorptiometry (DEXA) are prominently absent. In the present study, we measured BMD around the stem using DEXA and investigated changes over time from postoperative year 1 to year 2. Additionally, the relationship between BMD changes, filling ratio, and stem alignment was examined.

Methods

Forty-seven patients with short cementless stems who could be assessed via DEXA at 1-2 years postoperatively were included. After dividing the zones around the stem into 5, the BMD in each zone was measured, in addition to BMD changes and amount of change from postoperative year 1 to year 2. The relationship between filling ratio and stem alignment on postoperative plain radiography was assessed.

Results

A significant decrease in BMD in zone 3 was observed between postoperative year 1 and year 2 (P = .02). Regarding filling ratio and stem alignment, a negative correlation between valgus stem alignment and BMD change observed in zone 1 (r = -0.470, P < .01). In addition, stem valgus greater than 6° correlated with a significant decrease in BMD in zone 1. (P = .01). No significant differences were found in the other zones. Furthermore, there was no correlation between filling ratio and BMD change.

Conclusion

In reverse shoulder arthroplasty cementless short stems, changes that that occurred between postoperative year 1 to year 2 demonstrated a decrease in BMD in zone 3. In addition, a decrease in BMD in zone 1 was observed with a stem alignment of valgus 6° or higher, suggesting that stem alignment within valgus 6° is required to prevent a decrease in BMD.

Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

BACKGROUND

The EMPA-KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62-0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16-1·59), representing a 50% (42-58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1).

INTERPRETATION

In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease.

FUNDING

Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council.

Reliability and validity of a new deltoid muscle area measurement method after reverse shoulder arthroplasty

Background

Accurate deltoid muscle assessment after reverse shoulder arthroplasty (RSA) is difficult using magnetic resonance imaging due to metal artifacts. We hypothesized that measuring the deltoid muscle area (DA) in the middle part of the deltoid's total length postoperatively would reduce metal artifacts and allow for an accurate assessment. This study aimed to assess the reliability and reproducibility of magnetic resonance imaging and evaluate its impact on postoperative outcomes.

Methods

The DA in the middle part of the muscle's total length was measured twice by four examiners using pre and postoperative magnetic resonance imaging in 60 patients who underwent RSA (22 men, 38 women; mean age: 77.4 years). The DA at the greater tuberosity was measured preoperatively, and its correlation with the middle part of the deltoid's total length was evaluated. The Constant-Murley Score was measured at 2 years postoperatively, and its correlation with the DA in the middle part of the deltoid's total length pre- and postoperatively was assessed.

Results

Intraclass correlation coefficients for intraobserver measurements of preoperative and postoperative DA in the middle part of the deltoid's total length were almost perfect, with mean values of 0.98 and 0.97, respectively. The intraclass correlation coefficients for interobserver reliability regarding the first and second DA measurements in the middle part of the deltoid's total length were 0.95 and 0.95 (preoperatively) and 0.89 and 0.90 (postoperatively). The Constant-Murley Score was assessed at 2 years postoperatively in 51 patients. Muscle strength was weakly and moderately correlated with preoperative DA (r = 0.33, P = .02) and postoperative DA (r = 0.49, P < .01), respectively.

Conclusion

DA measurement in the middle part of the deltoid's total length after RSA was not affected by metal artifacts and had excellent reproducibility. This measurement method positively correlated with postoperative muscle strength, suggesting its usefulness for predicting postoperative muscle strength.

Parathyroid Hormone Inhibits Fatty Infiltration and Muscle Atrophy After Rotator Cuff Tear by Browning of Fibroadipogenic Progenitors in a Rodent Model

BACKGROUND

Progressive fatty infiltration and muscle atrophy after rotator cuff tears lead to tendon repair failure and poor outcomes. Fibro-adipogenic progenitors (FAPs) are involved in fatty infiltration and muscle homeostasis of skeletal muscle. Inducing FAP differentiation into brown adipocyte-like "beige adipocytes" suppresses fatty infiltration and muscle atrophy.

HYPOTHESIS

Parathyroid hormone (PTH) suppresses fatty infiltration and muscle atrophy after rotator cuff tears in a rat model by browning of FAPs.

STUDY DESIGN

Controlled laboratory study.

METHODS

PTH was administered subcutaneously for 4 or 8 weeks to a rotator cuff tear model in rats. After treatment, fatty infiltration of supraspinatus muscles was assessed using Oil Red O staining and muscle atrophy using wet muscle weight and muscle fiber cross-sectional area. Costaining of platelet-derived growth factor receptor α (FAP marker) and uncoupling protein 1 (browning marker) was performed to confirm FAP browning by PTH. Mouse-isolated FAPs were cultured with PTH and evaluated for browning-related gene expression and adipogenic differentiation using BODIPY staining. Myogenic differentiation of C2C12 myoblasts was evaluated using coculture of PTH-treated browning FAPs with C2C12.

RESULTS

PTH inhibited fatty infiltration after rotator cuff tear at 8 weeks. Rotator cuff wet muscle loss of PTH-treated rats was inhibited at 4 and 8 weeks. Furthermore, PTH-treated rats demonstrated larger myofiber cross-sectional area than did untreated rats at 4 and 8 weeks. Costaining indicated colocalization of platelet-derived growth factor receptor α and uncoupling protein 1 and promoted PTH-induced FAP browning. PTH increased the expression of browning-related genes in FAPs and suppressed fat droplet accumulation in vitro. Coculture with PTH-treated FAPs promoted C2C12 cell differentiation into myotubes.

CONCLUSION

PTH induced FAP-derived beige adipocytes by upregulating browning-related gene expression, and the browning effect of PTH on FAPs inhibited fatty infiltration and muscle atrophy in the rat rotator cuff tear model. PTH might have potential as a therapeutic drug for fatty infiltration and muscle atrophy after rotator cuff tears.

CLINICAL RELEVANCE

PTH may expand treatment options for rotator cuff tears by reducing fatty infiltration and muscle atrophy after rotator cuff tears by browning of FAPs.

Assessment of Prevalence and Risk Factors for Central Sensitization Related to Shoulder Osteoarthritis and Rotator Cuff Tears Using the Central Sensitization Inventory: A Cross-Sectional Study in Shoulder Surgery Patients

Shoulder disorders occasionally cause intractable pain. Central sensitization (CS) may be involved in such pain. Identifying risk factors associated with CS is crucial for effective pain control. This study aimed to determine the effects of shoulder osteoarthritis and rotator cuff tears (RCT) on CS and associated factors. This study included patients evaluated for CS using the Central Sensitization Inventory (CSI) before surgery for shoulder osteoarthritis, RCT, or cuff tear arthropathy. Patients with a CSI score of 40 or higher were defined as having CS. The relationships between glenohumeral osteoarthritis (GHOA), RCT size, and CS were statistically analyzed. Multiple regression analysis was performed to examine the factors affecting CSI scores. Subjects included 167 patients: 131 patients had RCT without GHOA, 23 had GHOA with RCT, and 13 had GHOA without RCT. The GHOA group had a significantly higher CSI score (27.5 [10.8-40.5] vs. 18.0 [10.0-27.5]) and CS prevalence (27.8% vs. 8.4%) than the RCT without GHOA group. There was no significant correlation between RCT size and CSI scores. Multiple regression analysis showed that female sex, severe pain, and long pain duration were associated with higher CSI scores. Considering the risk factors for CS might be helpful in shoulder treatment.

Use of Cannulated Screws for Primary Latarjet Procedures

Background

Rapid consolidation of the bone block is paramount for the success of the Latarjet procedure. Noncannulated screws have shown satisfactory long-term bone block fusion, while cannulated screws are challenged with inferior mechanical properties and fusion rates.

Purpose

To report outcomes of the Latarjet procedure using cannulated screws, notably bone block fusion and complication rates at 3 months, as well as clinical scores and return to sports at minimum 2 years postoperatively.

Study Design

Case series; Level of evidence, 4.

Methods

We reviewed the records of 124 consecutive patients (124 shoulders) who underwent primary Latarjet procedures using cannulated screws between 2015 and 2018. All patients underwent clinical examination at 3 months postoperatively, including range of motion and radiographs to assess graft fusion. The Walch-Duplay score, Rowe score, Subjective Shoulder Value, and visual analog scale for pain were collected at a minimum follow-up of 2 years.

Results

Overall, 9 patients (7%) required reoperation: 7 (6%) had screw removal for unexplained residual pain, 1 (0.8%) had lavage for deep infection, and 1 (0.8%) had evacuation to treat a hematoma. Furthermore, 3 patients (2.4%) had recurrent instability, none of whom underwent reoperation. At 3-month follow-up, all 124 shoulders showed complete radiographic graft fusion, and at 40 ± 11 months (mean ± SD; range, 24-64 months), 88% of patients had returned to sport (109/124), the Walch-Duplay score was 86 ± 14, Rowe was 84 ± 15, Subjective Shoulder Value was 88 ± 11, and visual analog scale for pain was 1 ± 1.

Conclusion

The clinical relevance of these findings is that 4.5-mm cannulated screws are safe and effective for primary Latarjet procedures and grant adequate graft healing, with low recurrence of instability and a high rate of return to sports.

In vivo study on the healing of bone defect treated with non-thermal atmospheric pressure gas discharge plasma

Medical treatment using non-thermal atmospheric pressure plasma (NTAPP) is rapidly gaining recognition. NTAPP is thought to be a new therapeutic method because it could generate highly reactive species in an ambient atmosphere which could be exposed to biological targets (e.g., cells and tissues). If plasma-generated reactive species could stimulate bone regeneration, NTAPP can provide a new treatment opportunity in regenerative medicine. Here, we investigated the impact of NTAPP on bone regeneration using a large bone defect in New Zealand White rabbits and a simple atmospheric pressure plasma (helium microplasma jet). We observed the recovery progress of the large bone defects by X-ray imaging over eight weeks after surgery. The X-ray results showed a clear difference in the occupancy of the new bone of the large bone defect among groups with different plasma treatment times, whereas the new bone occupancy was not substantial in the untreated control group. According to the results of micro-computed tomography analysis at eight weeks, the most successful bone regeneration was achieved using a plasma treatment time of 10 min, wherein the new bone volume was 1.51 times larger than that in the plasma untreated control group. Using H&E and Masson trichrome stains, nucleated cells were uniformly observed, and no inclusion was confirmed, respectively, in the groups of plasma treatment. We concluded the critical large bone defect were filled with new bone. Overall, these results suggest that NTAPP is promising for fracture treatment.

Poor results after pyrocarbon interpositional shoulder arthroplasty

BACKGROUND

This study aimed to describe the clinical outcomes and complications of 10 cases of pyrocarbon interposition shoulder arthroplasty (PISA).

METHODS

The clinical and radiographic records of 10 patients who underwent PISA using the InSpyre shoulder prosthesis (Tornier-Wright) between July 2012 and March 2017 were reviewed. The mean age at surgery was 55 years. Surgical indications included patients aged <60 years with Walch type B glenoid glenohumeral osteoarthritis (n = 7), avascular necrosis (AVN) of the humeral head (n = 1), or secondary severe glenohumeral osteoarthritis with axillary nerve dysfunction (n = 2). Outcomes of interest were postoperative complications and need for revision surgery, preoperative and postoperative patient-reported outcomes (Constant score [CS] and Subjective Shoulder Value [SSV]), and range of motion. The radiographic characteristics of the implants were evaluated.

RESULTS

Among the 10 patients, 5 underwent revision to reverse shoulder arthroplasty during the study period owing to poor clinical outcomes based on the CS and SSV. All 5 revised patients had Walch type B glenoid morphology at the time of the index procedure. The mean time to revision surgery in this subset of patients was 60 months. The remaining 5 patients who did not undergo any revision procedure had significant improvement in mean CS and SSV from 30-65 points and 32%-87%, respectively, but at a shorter duration of follow-up of 35 months.

CONCLUSION

High clinical failure rate and poor results at mean 5-year follow-up were found in younger PISA patients with baseline Walch B glenohumeral osteoarthritis. We would caution against use of PISA in this challenging patient population. PISA yielded more favorable short-term outcomes in patients with humeral-sided deformity or severe secondary glenohumeral osteoarthritis with axillary nerve dysfunction; however, longevity of the implant in this population remains unclear.

The accelerated effect of recombinant human bone morphogenetic protein 2 delivered by β-tricalcium phosphate on tendon-to-bone repair process in rabbit models

BACKGROUND

Bone morphogenetic protein 2 (BMP-2) plays an important role in the tendon-to-bone repair process. However, there is no previous literature on acceleration of the tendon-to-bone repair process by BMP-2 delivered by β-tricalcium phosphate (β-TCP). The aim of this study was to investigate the accelerated effect of recombinant human BMP-2 (rhBMP-2) delivered by β-TCP on the tendon-to-bone repair process.

METHODS

The infraspinatus tendon of elderly female Japanese white rabbits was detached from its insertion site on the humerus. A bone tunnel (4.2 mm) was created at the original insertion site of the tendon, which was repaired using the McLaughlin procedure after filling in β-TCP (porosity 75%) without BMP-2 (control group) or with 10 µg rhBMP-2 (BMP group). The rabbits were sacrificed at the second, fourth, and eighth weeks after surgery for histologic analysis and biomechanical testing. We also evaluated the maturity of the tendon-to-bone junction using the tendon-to-bone maturity score.

RESULTS

Histologic analysis revealed no significant difference between the groups at 2 and 8 weeks but a more abundant organized fibrocartilage at the tendon-to-bone junction in the BMP group at 4 weeks. The tendon-to-bone maturity score improved sequentially. The interface of the BMP group at 4 weeks had significantly improved biomechanical properties than that of the control group.

CONCLUSION

The tendon-to-bone repair process was facilitated by the use of rhBMP-2 delivered by β-TCP at 4 weeks.

Long-term weight-change slope, weight fluctuation and risk of type 2 diabetes mellitus in middle-aged Japanese men and women: findings of Aichi Workers' Cohort Study

OBJECTIVE

This study aims to investigate the association of long-term weight-change slopes, weight fluctuation and the risk of type 2 diabetes mellitus (T2DM) in middle-aged Japanese men and women.

METHODS

A total of 4234 participants of Aichi Workers' Cohort Study who were aged 35-66 years and free of diabetes in 2002 were followed through 2014. Past body weights at the ages of 20, 25, 30, 40 years, and 5 years before baseline as well as measured body weight at baseline were regressed on the ages. Slope and root-mean-square-error of the regression line were obtained and used to represent the weight changes and the weight fluctuation, respectively. The associations of the weight-change slopes and the weight fluctuation with incident T2DM were estimated by Cox proportional hazards models.

RESULTS

During the median follow-up of 12.2 years, 400 incident cases of T2DM were documented. After adjustment for baseline overweight and other lifestyle covariates, the weight-change slopes were significantly associated with higher incidence of T2DM (hazard ratio (HR): 1.80, 95% confident interval (CI): 1.17-2.77 for men; and HR: 2.78, 95% CI: 1.07-7.23 for women), while the weight fluctuation was not (HR: 1.08, 95% CI: 1.00-1.18 for men and HR: 1.02, 95% CI: 0.84-1.25 for women).

CONCLUSIONS

Regardless of the presence of overweight, the long-term weight-change slopes were significantly associated with the increased risk of T2DM; however, the weight fluctuation was not associated with the risk of T2DM in middle-aged Japanese men and women.

Depression but not anxiety predicts recurrent cerebrovascular events

OBJECTIVES

Depression and anxiety after stroke occur frequently and have been suggested to have negative influence on functional outcomes. However, the effect of emotional symptoms on stroke recurrence is uncertain. The aim of this study was to define the effect of emotional symptoms on recurrent cerebrovascular events in patients with ischemic stroke.

MATERIALS AND METHODS

This was a hospital-based cohort study including patients with ischemic stroke who participated in a Community Stroke Care Program that provided secondary stroke prevention strategies during 6 months transition period after discharge. We examined the association between depression and anxiety and the risk of recurrent cerebrovascular events using logistic regression model. Depression and anxiety were defined as a score of 7 or more in Hospital Anxiety and Depression Scale at 2 weeks after discharge. Recurrent cerebrovascular events comprised any recurrent stroke and transient ischemic attack (TIA) occurring during 6 months after discharge.

RESULTS

Among 182 patients, 29 (15.9%) were depressed and 41 (22.5%) had anxiety symptoms. During the follow-up period, 9 patients experienced recurrent cerebrovascular events (5 of stroke and 4 of TIA). Depression was associated with recurrent cerebrovascular events at 6 months after adjustment for age, sex, and stroke severity (OR 5.22, 95% CI 1.08-25.12; P = 0.04), whereas anxiety was not (OR 0.98, 95% CI 0.2-4.92; P = 0.982).

CONCLUSIONS

Depression occurring early after stroke was associated with the increased risk of recurrent cerebrovascular events in ischemic stroke survivors. Care plan to detect and manage depression should be implemented to prevent recurrent stroke.

Prediction of 10-year vascular risk in patients with diabetes: the AD-ON risk score

AIMS

To formulate a combined cardiovascular risk score in diabetes that could be useful both to physicians and healthcare funders.

METHODS

Data were derived from the Action in Diabetes and Vascular Disease: Preterax and Diamicron Modified Release Controlled Evaluation Observational (ADVANCE-ON) study, a randomized controlled trial (mean duration 5 years) with a post-randomization follow-up (mean 4.9 years), that included 11 140 high-risk patients with diabetes. The outcome analysed was the occurrence of either fatal or non-fatal macrovascular or renal disease. A Cox regression model was used to determine weightings in the risk score. The resultant score was recalibrated to each of three major global regions, as covered by the ADVANCE-ON study.

RESULTS

Over a median of 9.9 years, 1145 patients experienced at least one component of the combined outcome event. The resultant score, the AD-ON risk score, incorporated 13 demographic or clinical variables. Its discrimination was modest [c-statistic = 0.668 (95% confidence interval 0.651, 0.685)] but its calibration was excellent (predicted and observed risks coincided well, within disparate global regions). In terms of the integrated discrimination improvement index, its performance was marginally superior, over a 10-year risk horizon, to existing risk scores in clinical use, from a restricted version of the same data, for macrovascular and renal disease separately.

CONCLUSIONS

The AD-ON risk score has advantages over the existing vascular risk scores in diabetes that used data from the original ADVANCE trial, which treat macrovascular and renal diseases separately. These advantages include its simplicity of use and global application.

Magnesium intake decreases Type 2 diabetes risk through the improvement of insulin resistance and inflammation: the Hisayama Study

AIMS

Early studies have shown that magnesium intake decreases the risk of Type 2 diabetes, but the results are still inconsistent. We prospectively examined the association between magnesium intake and incidence of Type 2 diabetes in a general Japanese population.

METHODS

A total of 1999 subjects without diabetes aged 40-79 years who underwent a 75-g oral glucose tolerance test were followed up prospectively for a mean of 15.6 years.

RESULTS

During the follow-up, 417 subjects developed Type 2 diabetes. The age- and sex-adjusted incidence of Type 2 diabetes significantly decreased with increasing magnesium intake quartile levels (≤ 148.5, 148.6-171.5, 171.6-195.5 and ≥ 195.6 mg/day, P for trend = 0.01). In multivariate analyses, after adjusting for comprehensive risk factors and other dietary factors, the hazard ratio of Type 2 diabetes was 0.67 (95% CI 0.49-0.92; P = 0.01) in the third quartile and 0.63 (95% CI 0.44-0.90; P = 0.01) in the highest quartile compared with the first quartile. In addition, the risk of Type 2 diabetes was 14% lower (P = 0.04) for a 1-sd increment of log-transformed magnesium intake in the multivariate-adjusted model. In stratified analysis, there were statistically significant interactions between magnesium intake and levels of homeostasis model assessment of insulin resistance, high-sensitivity C-reactive protein or alcohol intake on the risk of Type 2 diabetes (all P < 0.05).

CONCLUSIONS

Our findings suggest that increased magnesium intake was a significant protective factor for the incidence of Type 2 diabetes in the general Japanese population, especially among subjects with insulin resistance, low-grade inflammation and a drinking habit.

Impact of eating rate on obesity and cardiovascular risk factors according to glucose tolerance status: the Fukuoka Diabetes Registry and the Hisayama Study

AIMS/HYPOTHESIS

Medical nutrition therapy plays a critical role in the prevention and treatment of type 2 diabetes. However, appropriate measures of eating behaviours, such as eating rate, have not yet been clearly established. The aim of the present study was to examine the associations among eating rate, obesity and cardiovascular risk factors.

METHODS

A total of 7,275 Japanese individuals aged ≥40 years who had normal fasting glucose levels, impaired fasting glucose or diabetes were divided into four groups according to self-reported eating rate: slow, medium, relatively fast and very fast. The associations between eating rate and various cardiovascular risk factors were investigated cross-sectionally.

RESULTS

The proportions of participants who were obese or who had elevated waist circumference levels increased progressively with increases in eating rate (p for trend <0.001), regardless of glucose tolerance status. These associations remained significant after adjustment for potential confounders, namely, age, sex, total energy intake, dietary fibre intake, current smoking, current drinking and regular exercise (p for trend <0.001). Blood pressure and lipid levels also tended to increase in association with eating rate. HbA(1c) rose significantly as eating rate increased, even after multivariate adjustment, including BMI, in diabetic patients on insulin therapy (p = 0.02), whereas fasting plasma glucose did not increase significantly.

CONCLUSIONS/INTERPRETATION

Our findings suggest that eating rate is associated with obesity and other cardiovascular risk factors and therefore may be a modifiable risk factor in the management of cardiovascular risk factors and diabetes.

Two risk score models for predicting incident Type 2 diabetes in Japan

AIMS

Risk scoring methods are effective for identifying persons at high risk of Type 2 diabetes mellitus, but such approaches have not yet been established in Japan.

METHODS

A total of 1935 subjects of a derivation cohort were followed up for 14 years from 1988 and 1147 subjects of a validation cohort independent of the derivation cohort were followed up for 5 years from 2002. Risk scores were estimated based on the coefficients (β) of Cox proportional hazards model in the derivation cohort and were verified in the validation cohort.

RESULTS

In the derivation cohort, the non-invasive risk model was established using significant risk factors; namely, age, sex, family history of diabetes, abdominal circumference, body mass index, hypertension, regular exercise and current smoking. We also created another scoring risk model by adding fasting plasma glucose levels to the non-invasive model (plus-fasting plasma glucose model). The area under the curve of the non-invasive model was 0.700 and it increased significantly to 0.772 (P < 0.001) in the plus-fasting plasma glucose model. The ability of the non-invasive model to predict Type 2 diabetes was comparable with that of impaired glucose tolerance, and the plus-fasting plasma glucose model was superior to it. The cumulative incidence of Type 2 diabetes was significantly increased with elevating quintiles of the sum scores of both models in the validation cohort (P for trend < 0.001).

CONCLUSIONS

We developed two practical risk score models for easily identifying individuals at high risk of incident Type 2 diabetes without an oral glucose tolerance test in the Japanese population.

Cut-off values of fasting and post-load plasma glucose and HbA1c for predicting Type 2 diabetes in community-dwelling Japanese subjects: the Hisayama Study

AIMS

We examined the optimal cut-off values of fasting plasma glucose, 2-h post-load glucose and HbA(1c) for predicting Type 2 diabetes in community-dwelling Japanese subjects.

METHODS

A total of 1982 subjects without diabetes aged 40-79 years who underwent a 75-g oral glucose tolerance test were followed prospectively for 14 years by annual health examination.

RESULTS

During the follow-up, 295 subjects developed Type 2 diabetes. Compared with the first decile, the crude hazard ratio for incident Type 2 diabetes was significantly higher in the fifth fasting plasma glucose decile [5.4-5.4 mmol/l (97-98 mg/dl)] or higher, in the seventh 2-h post-load glucose decile [6.9-7.2 mmol/l (124-131 mg/dl)] or higher, and in the fifth HbA(1c) decile [34-36 mmol/mol (5.3-5.4%)] or higher. These associations remained substantially unchanged even after adjustment for confounding factors. The receiver operating characteristic curve analysis showed that the optimal cut-off values for predicting Type 2 diabetes were 5.6 mmol/l (101 mg/dl) for fasting plasma glucose, 6.9 mmol/l (124 mg/dl) for 2-h post-load glucose and 37 mmol/mol (5.5%) for HbA(1c). In a stratified analysis, the cut-off values were approximately 5.6 mmol/l (101 mg/dl) for fasting plasma glucose and 37 mmol/mol (5.5%) for HbA(1c), and these values were unchanged over BMI quartile levels, whereas the 2-h post-load glucose cut-off values declined with decreasing BMI levels.

CONCLUSIONS

Our findings suggest that the cut-off value for predicting Type 2 diabetes in the Japanese population is 5.6 mmol/l (101 mg/dl) for fasting plasma glucose and 37 mmol/mol (5.5%) for HbA(1c), while the 2-h post-load glucose cut-off value is lower than the diagnostic criterion for impaired glucose tolerance.

Glucose tolerance status and risk of dementia in the community: the Hisayama study

OBJECTIVE

We investigated the association between glucose tolerance status defined by a 75-g oral glucose tolerance test (OGTT) and the development of dementia.

METHODS

A total of 1,017 community-dwelling dementia-free subjects aged ≥60 years who underwent the OGTT were followed up for 15 years. Outcome measure was clinically diagnosed dementia.

RESULTS

The age- and sex-adjusted incidence of all-cause dementia, Alzheimer disease (AD), and vascular dementia (VaD) were significantly higher in subjects with diabetes than in those with normal glucose tolerance. These associations remained robust even after adjustment for confounding factors for all-cause dementia and AD, but not for VaD (all-cause dementia: adjusted hazard ratio [HR] = 1.74, 95% confidence interval [CI] = 1.19 to 2.53, p = 0.004; AD: adjusted HR = 2.05, 95% CI = 1.18 to 3.57, p = 0.01; VaD: adjusted HR = 1.82, 95% CI = 0.89 to 3.71, p = 0.09). Moreover, the risks of developing all-cause dementia, AD, and VaD significantly increased with elevated 2-hour postload glucose (PG) levels even after adjustment for covariates, but no such associations were observed for fasting plasma glucose (FPG) levels: compared with those with 2-hour PG levels of <6.7 mmol/L, the multivariable-adjusted HRs of all-cause dementia and AD significantly increased in subjects with 2-hour PG levels of 7.8 to 11.0 mmol/L or over, and the risk of VaD was significantly higher in subjects with levels of ≥11.1 mmol/L.

CONCLUSIONS

Our findings suggest that diabetes is a significant risk factor for all-cause dementia, AD, and probably VaD. Moreover, 2-hour PG levels, but not FPG levels, are closely associated with increased risk of all-cause dementia, AD, and VaD.

Association of Alzheimer disease pathology with abnormal lipid metabolism: the Hisayama Study

OBJECTIVE

The relationship between lipid profiles and Alzheimer disease (AD) pathology at the population level is unclear. We searched for evidence of AD-related pathologic risk of abnormal lipid metabolism.

METHODS

This study included brain specimens from a series of 147 autopsies performed between 1998 and 2003 of residents in Hisayama town, Japan (76 men and 71 women), who underwent clinical examinations in 1988. Lipid profiles, such as total cholesterol (TC), triglycerides, and high-density lipoprotein cholesterol (HDLC), were measured in 1988. Low-density lipoprotein cholesterol (LDLC) was calculated using the Friedewald formula. Neuritic plaques (NPs) were assessed according to the Consortium to Establish a Registry for Alzheimer's Disease guidelines (CERAD) and neurofibrillary tangles (NFTs) were assessed according to Braak stage. Associations between each lipid profile and AD pathology were examined by analysis of covariance and logistic regression analyses.

RESULTS

Adjusted means of TC, LDLC, TC/HDLC, LDLC/HDLC, and non-HDLC (defined as TC-HDLC) were significantly higher in subjects with NPs, even in sparse to moderate stages (CERAD = 1 or 2), compared to subjects without NPs in multivariate models including APOE ε4 carrier and other confounding factors. The subjects in the highest quartiles of these lipid profiles had significantly higher risks of NPs compared to subjects in the lower respective quartiles, which may suggest a threshold effect. Conversely, there was no relationship between any lipid profile and NFTs.

CONCLUSION

The results of this study suggest that dyslipidemia increases the risk of plaque-type pathology.

Delayed adverse reactions to iodinated radiographic contrast media after coronary angiography: a search for possible risk factors

OBJECTIVE

The incidence of and risk factors for delayed adverse events (DAEs) that appear from 1 h to 7 days after injection of radiographic contrast media were investigated in patients who had undergone coronary angiography (CAG).

METHODS

DAEs were monitored by questionnaire in 155 patients who received iomeprol. Isosorbide dinitrate was injected in every case. Risk factors for DAEs were analysed by a logistic regression model.

RESULTS

Of 118 patients who returned questionnaires, 54 complained of DAEs, although no severe or fatal reactions occurred. Erythema, rash and nausea were frequent events. Female gender, total dose of isosorbide dinitrate <2 mg, and execution of acetylcholine provocation test were found to be the major risk factors, and the incidence of DAEs increased as the number of risk factors increased.

CONCLUSION

Care should be taken when CAG is performed on female patients who undergo acetylcholine provocation tests and receive low-dose nitric oxide donor injections.

Efficacy of immunoliposomes on cancer models in a cell-surface-antigen-density-dependent manner

We have recently established a cancer-reactive human monoclonal antibody, GAH, with a positive ratio of over 90% against stomach cancer. GAH was formulated as polyethyleneglycol (PEG)-modified immunoliposomal doxorubicin (DXR) (ILD) and its efficacy was examined against gastrointestinal human cancers. In in vitro studies, a comparison of ILD with PEG-modified liposomal DXR (LD) demonstrated that ILD had dose-dependent cytotoxicity for GAH-reactive B37 cancer cells, but not LD. In concordance with this result, microscopic observations showed that ILD was bound to and GAH-dependently internalised by B37 cells. In in vivo studies, ILD exhibited significantly greater antitumour activity on cancer xenograft models than LD or free DXR. The relation between efficacy and antigen density was examined on 10 xenograft models bearing cancer cells with varying GAH reactivity. Immunoliposomal doxorubicin therapeutic activity correlated with the antigen density, with a minimum number being required. Also, ILD revealed strong antitumour activity on cancers with low sensitivity to DXR or LD, suggesting that ILD overcame the DXR resistance of antigen-positive cancer cells. Thus, these results show that GAH endows liposomes with targeting activity, resulting in strong efficacy against gastrointestinal cancers.

An extended cavity femtosecond Cr:LiSAF laser pumped by low cost diode lasers

We describe an extended cavity femtosecond Cr:LiSAF laser pumped by inexpensive single spatial mode diodes. Using a multi-pass cavity (MPC) to lower the repetition rate and a saturable Bragg reflector (SBR) for mode-locking, pulse energies of 0.75 nJ at a repetition rate of 8.6 MHz are achieved with durations of 39 fs and bandwidths of 20 nm in a prismless configuration. Pulse energies of 0.66 nJ at a repetition rate of 8.4 MHz with durations of 43 fs and bandwidths of 18.5 nm are generated using prisms for dispersion compensation. This laser offers performance approaching that of standard Ti:sapphire lasers at a fraction of the cost.

A novel spermatogenesis-related factor-1 gene expressed in maturing rat testis

A rat gene with testis-specific expression coinciding with spermatogenesis was cloned by differential display. This spermatogenesis-related factor-1 (SRF-1) gene was not expressed in other organs. Testicular expression was detected from 5 weeks of age and increased up to 15 weeks; this level of expression was maintained for 63 weeks. The 750-bp cloned gene was coded for an open reading frame of 202 amino acids. According to in situ hybridization at 7 weeks, this gene was expressed mainly in spermatocyte. The gene product may function as a molecular motor in meiosis, as the deduced amino acid sequence showed partial homology with kinesin-related proteins. The action of this gene and its product with respect to division of reproductive cells requires further investigation.

[Lipid-lowering drugs]

Accumulating evidences in recent major clinical studies have shown the importance of anti-hyperlipidemic treatment in preventing atherosclerotic cardiovascular diseases. Lipid-lowering drugs can be divided into HMG-CoA reductase inhibitors (statins), bile-acid sequestrants (resins), nicotinic acid, fibrates and probucol. Among them, statins had revolutionary impact on the treatment of hyperlipidemia since pravastatin, which was developed in Japan, was launched in 1989. Several lipid-lowering drugs are now under development in Japan, including pitavastatin, rosuvastatin, F-1394 (ACAT inhibitor), CS-505 (ACAT inhibitor) and NO-1886 (LPL activator). In this review, characteristics of these new lipid-lowering drugs will be discussed.

Generation of highly repetitive optical pulses based on intracavity four-wave Raman mixing

An extremely long train of highly repetitive pulse (17 THz) is obtained by the rotational four-wave Raman mixing of molecular hydrogen in a resonator using a computer simulation. This highly repetitive pulse can be obtained only when the laser wavelength and the resonator are adjusted to specified values. This pulse train has potential for use in ultrafast data communication because of the accurately determined repetition rate or even as a frequency standard, since the frequencies of the emission lines can be stabilized and locked to the above values.

Characterization of phosphor materials for use in plasma display panel by time-resolved vacuum-ultraviolet laser spectrometry

Phosphor materials that were manufactured for use in a plasma display panel (PDP) were investigated by employing a newly designed time-resolved vacuum-ultraviolet (VUV) spectrometer, which consists of a pulsed VUV laser and a fast photodetector. The VUV spectrometer was used to collect quantum efficiency data as well as the rise and decay times for the PDP phosphor luminescence. Both the rise and decay times increased with decreasing excitation wavelength in the VUV region. This result can be explained by a change in the mechanisms of photoexcitation and luminescence, that is, from charge-transfer excitation to host-lattice excitation below 200 nm. The present instrument was also used for an evaluation of the phosphor materials (Ba(1 - x)MgAl10O17:Eu2+(x)) by changing the Eu2+ concentration. The obtained data suggest that the impurities and defects are located inside the host crystal. Thus, the VUV spectrometer constructed in this study has considerable potential for use in investigating the nature of PDP phosphor materials.

Development of tunable picosecond dye laser for multiphoton ionization of dioxin precursors in supersonic jet/time-of-flight mass spectrometry

A distributed-feedback dye laser has been developed for achieving the efficient multiphoton ionization of chlorobenzene and dichlorobenzene, that is, precursor molecules of dioxins. This tunable picosecond laser with a narrow spectral line width, that is, a nearly transform-limited pulse, provides a more efficient ionization than the nanosecond laser, which is currently in use in supersonic jet spectrometry. The advantage of picosecond over nanosecond and femtosecond lasers is also discussed on the basis of the theoretical model reported in a previous paper.

A leucine(7)-to-proline(7) polymorphism in the signal peptide of neuropeptide Y was not identified in the Japanese population

OBJECTIVE

A Leu(7)-to-Pro(7) polymorphism exists in the signal peptide part of prepro-neuropeptide Y (NPY) and this polymorphism is associated with high serum cholesterol and LDL cholesterol levels in both Finnish and Dutch people. There was a significant difference in the allelic frequencies among populations with different genetic backgrounds. Therefore, the present study was designed to test whether Japanese people had the Leu(7)-to-Pro(7) polymorphism in the NPY signal peptide.

METHODS

A total of 102 healthy Japanese volunteers supplied blood samples, from which leucocyte DNA was isolated. Primer pairs for the polymerase chain reaction (PCR) were made according to Karvonen et al. Direct sequencing of the PCR product was carried out by the dye terminator method using a capillary electrophoresis sequencer.

RESULTS

All 102 young healthy Japanese subjects showed Leu(7)/Leu(7) but not Leu(7)/Pro(7) or Pro(7)/Pro(7) in the NPY signal peptide.

CONCLUSION

The incidence of the Leu(7)-to-Pro(7) polymorphism in the signal peptide of NPY was extremely low in Japanese people, suggesting that the polymorphism producing Pro(7) is not one of the genetic determinant factors affecting serum cholesterol levels in Japanese people.

[Anti-atherosclerotic effect of Ca channel antagonist]

Although anti-atherosclerotic effects of Ca channel antagonists have been shown in animal studies, clinical trials have failed to show such effects in humans. In those clinical studies, Ca channel antagonists did not retard progression or induce regression of atherosclerosis, however, they seemed to inhibit development of new atherosclerotic lesions. In this review, current knowledge of anti-atherosclerotic effects of Ca channel antagonists will be discussed with a special reference to the results of recent clinical trials.

Properties of a native cation channel activated by Ca2+ store depletion in vascular smooth muscle cells

Depletion of intracellular Ca(2+) stores activates capacitative Ca(2+) influx in smooth muscle cells, but the native store-operated channels that mediate such influx remain unidentified. Recently we demonstrated that calcium influx factor produced by yeast and human platelets with depleted Ca(2+) stores activates small conductance cation channels in excised membrane patches from vascular smooth muscle cells (SMC). Here we characterize these channels in intact cells and present evidence that they belong to the class of store-operated channels, which are activated upon passive depletion of Ca(2+) stores. Application of thapsigargin (TG), an inhibitor of sarco-endoplasmic reticulum Ca(2+) ATPase, to individual SMC activated single 3-pS cation channels in cell-attached membrane patches. Channels remained active when inside-out membrane patches were excised from the cells. Excision of membrane patches from resting SMC did not by itself activate the channels. Loading SMC with BAPTA (1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid), which slowly depletes Ca(2+) stores without a rise in intracellular Ca(2+), activated the same 3-pS channels in cell-attached membrane patches as well as whole cell nonselective cation currents in SMC. TG- and BAPTA-activated 3-pS channels were cation-selective but poorly discriminated among Ca(2+), Sr(2+), Ba(2+), Na(+), K(+), and Cs(+). Open channel probability did not change at negative membrane potentials but increased significantly at high positive potentials. Activation of 3-pS channels did not depend on intracellular Ca(2+) concentration. Neither TG nor a variety of second messengers (including Ca(2+), InsP3, InsP4, GTPgammaS, cyclic AMP, cyclic GMP, ATP, and ADP) activated 3-pS channels in inside-out membrane patches. Thus, 3-pS nonselective cation channels are present and activated by TG or BAPTA-induced depletion of intracellular Ca(2+) stores in intact SMC. These native store-operated cation channels can account for capacitative Ca(2+) influx in SMC and can play an important role in regulation of vascular tone.

Hydrogen peroxide is an endothelium-derived hyperpolarizing factor in mice

The endothelium plays an important role in maintaining vascular homeostasis by synthesizing and releasing several endothelium-derived relaxing factors, such as prostacyclin, nitric oxide (NO), and the previously unidentified endothelium-derived hyperpolarizing factor (EDHF). In this study, we examined our hypothesis that hydrogen peroxide (H(2)O(2)) derived from endothelial NO synthase (eNOS) is an EDHF. EDHF-mediated relaxation and hyperpolarization in response to acetylcholine (ACh) were markedly attenuated in small mesenteric arteries from eNOS knockout (eNOS-KO) mice. In the eNOS-KO mice, vasodilating and hyperpolarizing responses of vascular smooth muscle per se were fairly well preserved, as was the increase in intracellular calcium in endothelial cells in response to ACh. Antihypertensive treatment with hydralazine failed to improve the EDHF-mediated relaxation. Catalase, which dismutates H(2)O(2) to form water and oxygen, inhibited EDHF-mediated relaxation and hyperpolarization, but it did not affect endothelium-independent relaxation following treatment with the K(+) channel opener levcromakalim. Exogenous H(2)O(2) elicited similar relaxation and hyperpolarization in endothelium-stripped arteries. Finally, laser confocal microscopic examination with peroxide-sensitive fluorescence dye demonstrated that the endothelium produced H(2)O(2) upon stimulation by ACh and that the H(2)O(2) production was markedly reduced in eNOS-KO mice. These results indicate that H(2)O(2) is an EDHF in mouse small mesenteric arteries and that eNOS is a major source of the reactive oxygen species.