An Experimental Feasibility Study Evaluating the Adequacy of a Sportswear-Type Wearable for Recording Exercise Intensity.

Sportswear-type wearables with integrated inertial sensors and electrocardiogram (ECG) electrodes have been commercially developed. We evaluated the feasibility of using a sportswear-type wearable with integrated inertial sensors and electrocardiogram (ECG) electrodes for evaluating exercise intensity within a controlled laboratory setting. Six male college athletes were asked to wear a sportswear-type wearable while performing a treadmill test that reached up to 20 km/h. The magnitude of the filtered tri-axial acceleration signal, recorded by the inertial sensor, was used to calculate the acceleration index. The R-R intervals of the ECG were used to determine heart rate; the external validity of the heart rate was then evaluated according to oxygen uptake, which is the gold standard for physiological exercise intensity. Single regression analysis between treadmill speed and the acceleration index in each participant showed that the slope of the regression line was significantly greater than zero with a high coefficient of determination (walking, 0.95; jogging, 0.96; running, 0.90). Another single regression analysis between heart rate and oxygen uptake showed that the slope of the regression line was significantly greater than zero, with a high coefficient of determination (0.96). Together, these results indicate that the sportswear-type wearable evaluated in this study is a feasible technology for evaluating physical and physiological exercise intensity across a wide range of physical activities and sport performances.

Characteristics of physical activity during beginner-level group tennis lessons and the effect daily activity.

Tennis is a popular leisure sport, and studies have indicated that playing tennis regularly provides many health benefits. We aimed to clarify the characteristics of physical activity during beginner-level group tennis lessons and daily physical activity of the participants. Physical activity was measured using an accelerometer sensor device for four weeks, including the 80-min duration tennis lessons held twice a week. Valid data were categorized for tennis and non-tennis days. The mean physical activity intensity during the tennis lesson was 3.37 METs. The mean ratio of short-bout rest periods to the tennis lesson time in 90 and 120 s was 7% and 4%, respectively. The mean physical activity intensity was significantly higher (p < 0.0001) and the duration of vigorous-intensity physical activity (VPA) was increased in 76% of participants on days with tennis lessons compared to without tennis lessons. Beginner-level tennis lesson has characteristics of less short-bout rest physical activity than previously reported competitive tennis match and increased the duration of VPA in daily activity compared to without tennis lessons, suggesting that beginner-level tennis lessons contribute physical activity of health benefits.

Tip Detection-Antegrade Dissection and Re-Entry With New Puncture Wire in CTO Intervention: Revolution Through 3D-Wiring.

Background: The authors devised the tip detection (TD) method and developed AnteOwl WR intravascular ultrasound to standardize intravascular ultrasound-based 3-dimensional wiring for intraplaque tracking in chronic total occlusion (CTO)-percutaneous coronary intervention (PCI). The TD method also allowed antegrade dissection and re-entry (ADR). Combining TD-ADR with Conquest Pro 12 Sharpened Tip (CP12ST) wire, a new ADR wire with the strongest penetration force developed to date, enabled re-entry anywhere except calcification sites. Objectives: This study investigated the efficacy and feasibility of TD-ADR by comparison of procedural outcomes with Stingray-ADR in CTO-PCI. Methods: Twenty-seven consecutive CTO cases treated by TD-ADR with CP12ST wire between August 2021 and April 2023 and 27 consecutive CTO cases treated by Stingray-ADR with Conquest 8-20 (CP20) wire between March 2018 and July 2021 were retrospectively enrolled as the TD-ADR by CP12ST wire group and Stingray-ADR by CP20 wire group, respectively, from 4 facilities that could share technical information on these procedures. Results: The success rate of the ADR procedure was significantly improved (27 of 27 cases [100%] vs 18 of 27 cases [67%], respectively; P = 0.002) and total procedural time was significantly reduced (median procedural time: 145.0 [Q1-Q3: 118.0-240.0] minutes vs 185.0 [Q1-Q3: 159.5-248.0] minutes, respectively; P = 0.028) in the TD-ADR by CP12ST wire group compared to the Stingray-ADR by CP20 wire group. There were few in-hospital major adverse cardiac and cerebrovascular events or no complications in either group. Conclusions: TD-ADR by CP12ST wire can standardize highly accurate ADR in CTO-PCI.

Long-term follow-up evaluation of results from clinical trial using hepatocyte growth factor gene to treat severe peripheral arterial disease.

OBJECTIVE: As angiogenic growth factors can stimulate the development of collateral arteries, a concept called therapeutic angiogenesis, we performed a phase I/IIa open-label clinical trial using intramuscular injection of naked plasmid DNA encoding hepatocyte growth factor (HGF). We reported long-term evaluation of 2 years after HGF gene therapy in 22 patients with severe peripheral arterial disease. METHODS AND RESULTS: Twenty-two patients with peripheral arterial disease or Buerger disease staged by Fontaine IIb (n=7), III (n=4), and IV (n=11) were treated with HGF plasmid, either 2 mg or 4 mg ×2. Increase in ankle-branchial pressure index >0.1 was observed in 11 of 14 patients (79 %) at 2 years after gene therapy and in 11 of the 17 patients (65%) at 2 months. Reduction in rest pain (>2 cm in visual analog scale) was observed in 9 of 9 patients (100%) at 2 years and in 8 of 13 (62%) patients at 2 months. At 2 years, 9 of 10 (90%) ischemic ulcers reduced by >25%, accompanied by a reduction in the size of ulcer. Severe complications and adverse effects caused by gene transfer were not detected in any patient throughout the period up to 2 years. CONCLUSIONS: Overall, the present study demonstrated long-term efficacy of HGF gene therapy up to 2 years. These findings may be cautiously interpreted to indicate that intramuscular injection of naked HGF plasmid is safe, feasible, and can achieve successful improvement of ischemic limbs as sole therapy.

Gaussian mixture modeling of acceleration-derived signal for monitoring external physical load of tennis player.

Introduction: With the widespread use of wearable sensors, various methods to evaluate external physical loads using acceleration signals measured by inertial sensors in sporting activities have been proposed. Acceleration-derived external physical loads have been evaluated as a simple indicator, such as the mean or cumulative values of the target interval. However, such a conventional simplified indicator may not adequately represent the features of the external physical load in sporting activities involving various movement intensities. Therefore, we propose a method to evaluate the external physical load of tennis player based on the histogram of acceleration-derived signal obtained from wearable inertial sensors. Methods: Twenty-eight matches of 14 male collegiate players and 55 matches of 55 male middle-aged players wore sportswear-type wearable sensors during official tennis matches. The norm of the three-dimensional acceleration signal measured using the wearable sensor was smoothed, and the rest period (less than 0.3 G of at least 5 s) was excluded. Because the histogram of the processed acceleration signal showed a bimodal distribution, for example, high- and low-intensity peaks, a Gaussian mixture model was fitted to the histogram, and the model parameters were obtained to characterize the bimodal distribution of the acceleration signal for each player. Results: Among the obtained Gaussian mixture model parameters, the linear discrimination analysis revealed that the mean and standard deviation of the high-intensity side acceleration value accurately classified collegiate and middle-aged players with 93% accuracy; however, the conventional method (only the overall mean) showed less accurate classification results (63%). Conclusion: The mean and standard deviation of the high-intensity side extracted by the Gaussian mixture modeling is found to be the effective parameter representing the external physical load of tennis players. The histogram-based feature extraction of the acceleration-derived signal that exhibit multimodal distribution may provide a novel insight into monitoring external physical load in other sporting activities.

Association between oral frailty and cystatin C-related indices-A questionnaire (OFI-8) study in general internal medicine practice.

BACKGROUND: Cystatin C-related indices such as the ratio of creatinine to cystatin C (Cr/CysC) and the ratio of estimated glomerular filtration rate by cystatin C (eGFRcys) to creatinine eGFRcre (eGFRcys/eGFRcre) levels have been shown to be associated with muscle mass and strength and can be markers of sarcopenia. Oral frailty is defined as an age-related gradual loss of oral functions, accompanied by a decline in cognitive and physical functions. It results in adverse health-related outcomes in older age, including mortality, physical frailty, functional disability, poor quality of life, and increased hospitalization and falls. Therefore, poor oral health among the elderly is an important health concern due to its association with the pathogenesis of systemic frailty, suggesting it to be a multidimensional geriatric syndrome. The Oral Frailty Index-8 (OFI-8) is a questionnaire that can be used for easy screening of oral frailty. This study aimed to investigate whether cystatin C- related indices are different between patients with low to moderate risk of oral frailty and those at high risk of oral frailty, using the OFI-8 in attending a general internal medicine outpatient clinic. MATERIALS AND METHODS: This is a cross-sectional study that included 251 patients with a mean age of 77.7±6.6 years and a median age of 77 years (128 men: mean age, 77.1±7.3 years; median age, 77 years and 123 women: mean age, 78.4±5.7 years; median age, 78 years) attending general internal medicine outpatient clinics. OFI-8 scores were tabulated by gender to determine whether there were differences between patients at low to moderate risk of oral frailty (OFI-8 score ≤3 points) and those at high risk (OFI-8 score ≥4 points) in Cr/CysC, eGFRcys/eGFRcre levels, height, weight, grip strength, etc. were examined. RESULTS: The OFI-8 score was higher in women than in men, suggesting that oral frailty is more common in women. Cr/CysC, eGFRcys/eGFRcre and grip strength were significantly lower in both men and women in the high-risk group for oral frailty (OFI-8 score ≥ 4). Height, hemoglobin level, red blood cell count, and serum albumin levels were significantly lower in men with an OFI-8 score ≥4. Receiver operating characteristic curve (ROC) analysis also showed that Cr/CysC and eGFRcys/eGFRcre were significantly associated with an OFI-8 score≥4 in both men and women. CONCLUSION: Cr/CysC and eGFRcys/eGFRcre were significantly lower in the high-risk group for oral frailty on the OFI-8in both men and women. A relationship exists among cystatin C-related indices, which can effectively screen systemic frailty. Similarly, the OFI-8 score can be used to effectively screen oral frailty. Thus, a collaboration that incorporates both systemic and oral frailty from medical and dental perspectives is required.

Trends in Antibody Titers after SARS-CoV-2 Vaccination-Insights from Self-Paid Tests at a General Internal Medicine Clinic.

Background: The rise in antibody titers against the novel coronavirus (SARS-CoV-2) and its duration are considered an important indicator for confirming the effect of a COVID-19 vaccine, and self-paid tests of antibody titer are conducted in many facilities nationwide. Methods: The relationship between the number of days after the second and third dose of vaccines, age, and antibody titer was determined from the medical records of general internal medicine clinics that conducted self-paid testing of the SARS-CoV-2 antibody titer using Elecsys Anti-SARS-CoV-2 S (Roche Diagnostics); the relationship between the number of days after two or more doses of vaccines and antibody titer was also determined. We also examined the antibody titers in cases of spontaneous infection with SARS-CoV-2 after two or more doses of the vaccine. Results: Log-transformed SARS-CoV-2 antibody titers measured within 1 month from the second or third dose of vaccine showed a negative correlation with age (p < 0.05). In addition, the log-transformed antibody titers also showed a negative correlation trend with the number of days after the second dose of vaccine (p = 0.055); however, there were no significant correlations between the log-transformed antibody titers and the number of days after the third dose of vaccine. The median antibody titer after the third vaccination was 18,300 U/mL, more than 10 times the median antibody titer after the second dose of vaccine, of 1185 U/mL. There were also some cases of infection after the third or fourth dose of vaccine, with antibody titers in the tens of thousands of U/ml after infection, but the patients still received further booster vaccinations after the infection. Conclusions: The antibody titers after the third vaccination did not attenuate after a short follow-up period of one month, while they tended to attenuate after the second vaccination. It is considered that many people in Japan received further booster vaccinations after spontaneous infection, even though they already had antibody titers in the tens of thousands of U/mL due to "hybrid immunity" after spontaneous infection following two or more doses of vaccine. The clinical significance of the booster vaccination in this population still needs to be thoroughly investigated and should be prioritized for those with low SARS-CoV-2 antibody titers.

Longitudinal Changes in IgG-Type SARS-CoV-2 Antibody Titers after COVID-19 Vaccination and a Prominent Increase in Antibody Titers When Infected after Vaccination.

OBJECTIVE: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody titers level and duration of elevated levels are considered important indicators for confirming the efficacy of coronavirus disease 2019 (COVID-19) vaccines. The objective of this study was to demonstrate the changes in antibody titers after the second and third doses of the COVID-19 vaccine, and to determine the antibody titers in cases of spontaneous infection with SARS-CoV-2 after vaccination. MATERIALS AND METHODS: From June 2021 to February 2023, IgG-type SARS-CoV-2 antibody titers were measured in 127 participants, including 74 outpatients and 53 members of staff, at the Osaka Dental University Hospital (64 males and 63 females, mean age 52.3 ± 19.0 years). RESULTS: Consistent with previous reports, the SARS-CoV-2 antibody titer decreased with time, not only after the second dose but also after the third dose of the vaccine if there was no spontaneous COVID-19 infection. We also confirmed that the third booster vaccination was effective in increasing the antibody titer. A total of 21 cases of natural infections were observed after administering two or more doses of the vaccine. Thirteen of these patients had post-infection antibody titers exceeding 40,000 AU/mL, and some cases continued to maintain antibody titers in the tens of thousands of AU/mL even after more than 6 months had passed since infection. CONCLUSIONS: The rise in and duration of antibody titers against SARS-CoV-2 are considered important indicators for confirming the efficacy of novel COVID-19 vaccines. A longitudinal follow-up of antibody titers after vaccination in larger studies is warranted.

Phase I/IIa clinical trial of therapeutic angiogenesis using hepatocyte growth factor gene transfer to treat critical limb ischemia.

OBJECTIVE: To evaluate the safety and feasibility of intramuscular gene transfer using naked plasmid DNA-encoding hepatocyte growth factor (HGF) and to assess its potential therapeutic benefit in patients with critical limb ischemia. METHODS AND RESULTS: Gene transfer was performed in 22 patients with critical limb ischemia by intramuscular injection of HGF plasmid, either 2 or 4 mg, 2 times. Safety, ankle-brachial index, resting pain on a 10-cm visual analog scale, wound healing, and walking distance were evaluated before treatment and at 2 months after injection. No serious adverse event caused by gene transfer was detected over a follow-up of 6 months. Of particular importance, no peripheral edema, in contrast to that seen after treatment with vascular endothelial growth factor, was observed. In addition, the systemic HGF protein level did not increase during the study. At 2 months after gene transfer, the mean ± SD ankle-brachial index increased from 0.46 ± 0.08 to 0.59 ± 0.13 (P<0.001), the mean ± SD size of the largest ischemic ulcers decreased from 3.08 ± 1.54 to 2.32 ± 1.88 cm (P=0.007), and the mean ± SD visual analog scale score decreased from 5.92 ± 1.67 to 3.04 ± 2.50 cm (P=0.001). An increase in ankle-brachial index by >0.1, a reduction in ulcer size by >25%, and a reduction in visual analog scale score by >2 cm at 2 months after gene transfer were observed in 11 (64.7%) of 17 limbs, 18 (72%) of 25 ulcers, and 8 (61.5%) of 13 limbs, respectively. CONCLUSIONS: Intramuscular injection of naked HGF plasmid is safe and feasible and can achieve successful improvement of ischemic limbs as sole therapy.

Successful Reboot of High-Performance Sporting Activities by Japanese National Women's Handball Team in Tokyo, 2020 during the COVID-19 Pandemic: An Initiative Using the Japan Sports-Cyber Physical System (JS-CPS) of the Sports Research Innovation Project (SRIP).

The COVID-19 pandemic has negatively impacted sporting activities across the world. However, practical training strategies for athletes to reduce the risk of infection during the pandemic have not been definitively studied. The purpose of this report was to provide an overview of the challenges we encountered during the reboot of high-performance sporting activities of the Japanese national handball team during the 3rd wave of the COVID-19 pandemic in Tokyo, Japan. Twenty-nine Japanese national women's handball players and 24 staff participated in the study. To initiate the reboot of their first training camp after COVID-19 stay-home social policy, we conducted: web-based health-monitoring, SARS-CoV-2 screening with polymerase chain reaction (PCR) tests, real-time automated quantitative monitoring of social distancing on court using a moving image-based artificial intelligence (AI) algorithm, physical intensity evaluation with wearable heart rate (HR) and acceleration sensors, and a self-reported online questionnaire. The training camp was conducted successfully with no COVID-19 infections. The web-based health monitoring and the frequent PCR testing with short turnaround times contributed remarkably to early detection of athletes' health problems and to risk screening. During handball, AI-based on-court social-distance monitoring revealed key time-dependent spatial metrics to define player-to-player proximity. This information facilitated appropriate on- and off-game distancing behavior for teammates. Athletes regularly achieved around 80% of maximum HR during training, indicating anticipated improvements in achieving their physical intensities. Self-reported questionnaires related to the COVID management in the training camp revealed a sense of security among the athletes that allowed them to focus singularly on their training. The challenges discussed herein provided us considerable knowledge about creating and managing a safe environment for high-performing athletes in the COVID-19 pandemic via the Japan Sports-Cyber Physical System (JS-CPS) of the Sports Research Innovation Project (SRIP, Japan Sports Agency, Tokyo, Japan). This report is envisioned to provide informed decisions to coaches, trainers, policymakers from the sports federations in creating targeted, infection-free, sporting and training environments.

Long-term retrospective observation study to evaluate effects of adiponectin on skeletal muscle in renal transplant recipients.

Although it has been reported that chronic kidney disease exacerbates sarcopenia progression, the mechanisms of the process remain unclear. Fifty-one patients who underwent renal transplantation at our hospital since 1998 (31 males and 20 females; aged 29-52 years at the time of transplantation) were retrospectively examined for the relationships among the psoas muscle index (PMI), intramuscular adipose tissue content (IMAC), serum adiponectin fractions (high-/low-molecular-weight) and new-onset diabetes after transplantation (NODAT). Before transplantation, age at kidney transplantation negatively correlated with PMI and positively correlated with IMAC (rS = - 0.427, p < 0.01; rS = 0.464, p < 0.01, respectively). Both at 1 and 5 years after transplantation, PMI was higher than before transplantation (p < 0.01). IMAC transiently decreased to - 0.39 at 1 year after kidney transplantation but subsequently increased to - 0.36 at 5 years after kidney transplantation. Multivariate analyses revealed that the mean increase in high-molecular weight adiponectin concentrations was an exacerbating factor for the mean change in PMI (p = 0.003). Moreover, the mean increases in IMAC were exacerbating factors for NODAT. In conclusion, the increase in the PMI is associated with high-molecular weight adiponectin levels after renal transplantation.

Inhibition of experimental abdominal aortic aneurysm progression by nifedipine.

Agents to inhibit the renin-angiotensin system have been reported to suppress the progression of abdominal aortic aneurysm (AAA). However, the effects of calcium channel blockers (CCBs) are still unclear in terms of the inhibition of the progression of AAA. Recently, several effects of CCBs beyond those associated with blood pressure lowering have attracted much interest. In this study, we examined the effects of nifedipine on AAA progression. AAA was induced in rats by transient aortic perfusion with elastase. Then, nifedipine (10 mg/kg/day) and saline (control) were administered to rats by osmotic mini-pump. At 2 and 4 weeks, the size of the AAA, blood pressure and heart rate were measured. Then, to further explore the mechanisms of the progression of AAA, we used human vascular smooth muscle cells (VSMCs). Especially, we focused on NF-kappaB and matrix metalloproteinase-9 (MMP-9). Treatment with nifedipine resulted in a significant inhibition of the progression of AAA such as aneurismal dilation at 14 and 28 days compared to the control (week 2: control, 2.98+/-0.71 mm; nifedipine, 2.37+/-0.64 mm; p<0.05 and week 4: control, 3.28+/-0.98 mm; nifedipine, 2.41+/-0.17 mm; p<0.05). Neither nifedipine nor saline changed blood pressure and heart rate, significantly. Nifedipine (1 microM) significantly suppressed angiotensin II-induced (10(-6) M) NF-kappaB activity in VSMCs by reporter assay (p<0.01). Furthermore, nifedipine (1 microM) inhibited MMP-9 protein expression and activity. Saline did not show such inhibitory effects. Taken together, these results indicated that nifedipine inhibits the progression of experimental AAA possibly through suppression of NF-kappaB and MMP-9 activity, leading to protective effects against AAA beyond those associated with blood pressure lowering.

Assessment of coronary stenosis by a 16-slice MDCT scanner in asymptomatic diabetic patients starting dialysis therapy.

BACKGROUND: The accuracy for the detection of coronary stenosis by multidetector row computed tomography (MDCT) has been getting more recognition. However, the usefulness of MDCT in patients with chronic kidney disease (CKD) has not been confirmed. METHODS: Weanalyzed 19 consecutive patients with asymptomatic diabetic CKD who underwent both MDCT and coronary angiography (CAG) at the initiation of dialysis. The definition of stenosis in this study was lesions with > or =50% stenosis by CAG. RESULTS: CAG revealed stenosis in 35 of 76 branches in 19 patients. Vessel diameter could not be evaluated by MDCT in 11 (14%) major vessels because of motion artifacts, pericardial effusion, pleural effusion, and severe calcification. Almost all of such lesions were located in the right coronary (4/11; 36%) or left circumflex (5/11; 45%) artery. The sensitivity, specificity, positive and negative predictive values of MDCT for a diagnosis of stenosis in the 65 evaluable major vessels were 86, 81, 78, and 88%, respectively. The severity of vessel calcification was increased in a stepwise manner with increments in the proportion of major vessels with > or =50% stenosis (p = 0.004 for trend). CONCLUSION: MDCT seemed to be an effective non-invasive method of screening patients with diabetic CKD for CAD.

Improvement of organ damage by a non-depressor dose of imidapril in diabetic spontaneously hypertensive rats.

Many clinical trials have demonstrated that angiotensin converting enzyme inhibitors have protective effects on organ damage, suggesting the importance of inhibition of the renin-angiotensin system. In this study, we investigated the effects of a non-depressor dose of imidapril on organ damage induced by diabetes and hypertension. Diabetes was induced by an intravenous injection of streptozotocin (STZ, 40 mg/kg) in 15-week-old male spontaneously hypertensive rats (SHR). Imidapril (2 mg/kg/day) or vehicle was given orally for 28 days, and then the heart weight, left ventricle mass (LVM), urinary albumin excretion (UAE) and endothelial function were examined, as well as the urinary NOx level and local hepatocyte growth factor (HGF) expression. There were no significant differences between the treated groups in systolic blood pressure and plasma parameters. On the other hand, UAE was significantly suppressed in the imidapril-treated group (450+/-44 mg/day) compared to the vehicle-treated group (963+/-182 mg/day) (p<0.01). Moreover, endothelial function assessed by dilative reaction to acetylcholine as well as cardiac hypertrophy assessed by both heart/body weight ratio and LVM were significantly improved in the imidapril-treated group (p<0.05 and p<0.01, respectively). The urinary NOx concentration and local HGF expression in vessel walls were also significantly increased in the imidapril-treated group (p<0.01). A non-depressor dose of imidapril showed protective effects against organ damage in diabetic SHR, which may be partially due to the increase of HGF and NO.

Reproducibility and clinical potential of myocardial mass at risk calculated by a novel software utilizing cardiac computed tomography information.

To select the best revascularization strategy a correct understanding of the ischemic territory and the coronary anatomy is crucial. Stress myocardial perfusion single photon emission computed tomography (SPECT) is the gold standard to assess ischemia, however, SPECT has important limitations such as lack of coronary anatomical information or false negative results due to balanced ischemia in multi-vessel disease. Angiographic scores are based on anatomical characteristics of coronary arteries but they lack information on the extent of jeopardized myocardium. Cardiac computed tomography (CCT) has the ability to evaluate the coronary anatomy and myocardium in one sequence, which is theoretically the ideal method to assess the myocardial mass at risk (MMAR) for any target lesion located at any point in the coronary tree. In this study we analyzed MMAR of the three main coronary arteries and three major side branches; diagonal (Dx), obtuse marginal (OM), and posterior descending artery (PDA) in 42 patients with normal coronary arteries using an algorithm based on the Voronoi method. The distribution of MMAR among the three main coronary arteries was 44.3 ± 5.6 % for the left anterior descending artery, 28.2 ± 7.3 % for the left circumflex artery, and 26.8 ± 8.6 % for the right coronary artery. MMAR of the three major side branches was 11.3 ± 3.9 % for the Dx, 12.6 ± 5.2 % for the OM and 10.2 ± 3.4 % for the PDA. Intra- and inter-observer analysis showed excellent correlation (r = 0.97; p < 0.0001 and r = 0.95; p < 0.0001, respectively). In conclusion, CCT-based MMAR assessment is reliable and may offer important information for selection of the optimal revascularization procedure.

Local delivery of plasmid DNA into rat carotid artery using ultrasound.

BACKGROUND: Although viral vector systems are efficient to transfect foreign genes into blood vessels, safety issues remain in relation to human gene therapy. In this study, we examined the feasibility of a novel nonviral vector system by using high-frequency, low-intensity ultrasound irradiation for transfection into blood vessels. METHODS AND RESULTS: Luciferase plasmid mixed with or without echo contrast microbubble (Optison) was transfected into cultured human vascular smooth muscle cells (VSMC) and endothelial cells (EC) with the use of ultrasound. Interestingly, luciferase activity was markedly increased in both cell types treated with Optison. We then transfected luciferase plasmid mixed with Optison by means of therapeutic ultrasound into rat artery. Two days after transfection, luciferase activity was significantly higher in carotid artery transfected with luciferase gene with Optison and ultrasound than with plasmid alone. In addition, we transfected an anti-oncogene (p53) plasmid into carotid artery after balloon injury as a model of gene therapy for restenosis. Two weeks after transfection, the intimal-to-medial area ratio in rats transfected with wild-type p53 plasmid complexed with Optison by means of ultrasound was significantly decreased as compared with control, accompanied by a significant increase in p53 protein. No apparent toxicity such as inflammation could be detected in blood vessels transfected with plasmid DNA with ultrasound and Optison. CONCLUSIONS: Overall, we demonstrated that an ultrasound transfection method with Optison enhanced transfection efficiency of naked plasmid DNA into blood vessels without any apparent toxicity. Transfection of p53 plasmid with the use of this method should be useful for safe clinical gene therapy without a viral vector system.

Impairment of collateral formation in lipoprotein(a) transgenic mice: therapeutic angiogenesis induced by human hepatocyte growth factor gene.

BACKGROUND: Although lipoprotein(a) (Lp[a]) is a risk factor for atherosclerosis, no study has documented the effects of Lp(a) on angiogenesis. In this study, we examined collateral formation in peripheral arterial disease (PAD) model in Lp(a) transgenic mice. In addition, we examined the feasibility of gene therapy by using an angiogenic growth factor, hepatocyte growth factor (HGF), to treat PAD in the presence of high Lp(a). METHODS AND RESULTS: In Lp(a) transgenic mice, the degree of natural recovery of blood flow after operation was significantly lower than that in nontransgenic mice. Of importance, there was a significant negative correlation between serum Lp(a) concentration and the degree of natural recovery of blood flow (P<0.05). In addition, Lp(a) significantly stimulated the growth of vascular smooth muscle, accompanied by the phosphorylation of ERK. These data demonstrated the association of impairment of collateral formation with serum Lp(a) concentration. Thus, we examined the feasibility of therapeutic angiogenesis by using HGF, with the goal of progression to human gene therapy. Intramuscular injection of HGF plasmid resulted in a significant increase in blood flow even in Lp(a) transgenic mice, accompanied by the detection of human HGF protein. A significant increase in capillary density also was detected in Lp(a) transgenic mice transfected with human HGF compared with control (P<0.01). CONCLUSIONS: Overall, a high serum Lp(a) concentration impaired collateral formation. Although the delay of angiogenesis in high serum Lp(a) might diminish angiogenesis, intramuscular injection of HGF plasmid induced therapeutic angiogenesis in the Lp(a) transgenic ischemic hindlimb mouse model as potential therapy for PAD.

Hepatocyte growth factor prevents endothelial cell death through inhibition of bax translocation from cytosol to mitochondrial membrane.

Injury of endothelial cells has been postulated to be an initial trigger of the progression of atherosclerosis in patients with diabetes. Previously, we demonstrated high D-glucose induced endothelial apoptosis through the bax-caspase pathway and the potential contribution of hepatocyte growth factor (HGF) to the pathogenesis of endothelial dysfunction. In this study, we analyzed the molecular mechanisms of the protective actions of HGF against endothelial cell death under high D-glucose conditions. High concentrations of D-glucose resulted in a significant increase in apoptosis and necrosis. In contrast, HGF attenuated high D-glucose-induced apoptosis and necrosis (P < 0.01). High D-glucose significantly increased bax protein, but not bcl-2, and activated caspase 3-like and 9, whereas HGF significantly increased bcl-2 expression without affecting bax level and attenuated the increase in caspase 3 and 9 activity. Interestingly, high D-glucose resulted in translocation of bax protein from cytosol to the mitochondrial membrane, whereas HGF inhibited the bax translocation. Importantly, this bax translocation was also completely blocked by overexpressed bcl-2. These findings suggest that HGF can activate bcl-2 expression and inhibit translocation of bax protein upstream of the mitochondria, thereby leading to the inhibition of caspase 3 and 9 activation. HGF may be an important factor in the maintenance of endothelial function.

Therapeutic angiogenesis using hepatocyte growth factor (HGF).

HGF is a mesenchyme-derived pleiotropic factor, which regulates cell growth, cell motility, and morphogenesis of various types of cells and is thus considered a humoral mediator of epithelial-mesenchymal interactions responsible for morphogenic tissue interactions during embryonic development and organogenesis. Although HGF was originally identified as a potent mitogen for hepatocytes, it has also been identified as a member of angiogenic growth factors. Interestingly, the presence of its specific receptor, c-met, is observed in vascular cells and cardiac myocytes. In addition, among growth factors, the mitogenic action of HGF on human endothelial cells was most potent. Recent studies have demonstrated the potential application of HGF to treat cardiovascular diseases such as peripheral vascular disease, myocardial infarction and cerebrovascular disease. In this review, we will discuss a potential therapeutic strategy using HGF in cardiovascular disease.