Autologous bone-marrow mononuclear cell implantation reduces long-term major amputation risk in patients with critical limb ischemia: a comparison of atherosclerotic peripheral arterial disease and Buerger disease

BACKGROUND

Bone-marrow mononuclear cell (BM-MNC) implantation improves ischemic symptoms in patients with critical limb ischemia (CLI). The purpose of this study was to evaluate long-term clinical outcomes after autologous BM-MNC implantation in patients with CLI.

METHODS AND RESULTS

We assessed long-term clinical outcomes after BM-MNC implantation in 51 patients with CLI, including 25 patients with peripheral arterial disease (PAD) and 26 patients with Buerger disease. Forty-six CLI patients who had no BM-MNC implantation served as control subjects. Median follow-up period was 4.8 years. The 4-year amputation-free rates after BM-MNC implantation were 48% in PAD patients and 95% in Buerger disease, and they were 0% in control PAD patients and 6% in control Buerger disease. The 4-year overall survival rates after BM-MNC implantation were 76% in PAD patients and 100% in Buerger disease, and they were 67% in control PAD patients and 100% in control Buerger disease. Multivariable Cox proportional hazards analysis revealed that BM-MNC implantation correlated with prevention of major amputation and that hemodialysis and diabetes mellitus correlated with major amputation. In Buerger disease, ankle brachial pressure index and transcutaneous oxygen pressure were significantly increased after 1 month and remained high during 3-year follow-up. However, in patients with PAD, ankle brachial pressure index and transcutaneous oxygen pressure significantly increased after 1 month and gradually decreased during 3-year follow-up and returned to baseline levels.

CONCLUSIONS

These findings suggest that BM-MNC implantation is safe and effective in patients with CLI, especially in patients with Buerger disease. Clinical Trial Registration- URL: http://home.hiroshima-u.ac.jp/angio/. Unique identifier: 001769.

Therapeutic approaches targeting tumor vasculature in gastrointestinal cancers

Antiangiogenic therapy, especially anti-vascular endothelial growth factor (VEGF) antibody therapy, has become an important treatment option for the management of a number of human malignancies including some gastrointestinal tumors. However, there have been many cases of resistance observed against anti-VEGF antibody treatment. As to the first reason, some types of advanced colon cancers do not upregulate VEGF. As to the second reason, not a few malignancies will acquire phenotypic resistance to VEGF or its receptors after anti-VEGF antibody therapy. The molecular and cellular mechanisms associated with the resistance to VEGF-targeted agents are not fully understood. Better understanding of the mechanisms and improvement of antiangiogenic regimens to overcome drug resistance would help in the selection of those patients who are more likely to benefit from VEGF-targeted therapy. Other possible applications of anti-VEGF antibody include chemoprevention of cancer progression. It is well known that angiogenic switch and upregulation of angiogenic cascades are essential for cancer development. Therefore, prophylatic application of anti-VEGF antibody before angiogenic switch may inhibit aggressive growth of these malignancies at an initial phase.

Vascular Function and Circulating Progenitor Cells in Thromboangitis Obliterans (Buerger's Disease) and Atherosclerosis Obliterans

Thromboangitis obliterans (TAO; Buerger's disease) and atherosclerosis obliterans (ASO) are associated with endothelial dysfunction. The purpose of this study was to evaluate the role of circulating progenitor cells (CPCs) in endothelial function in patients with TAO and ASO. We measured flow-mediated vasodilation (FMD), nitroglycerine-induced vasodilation, and circulating CPCs in 30 patients with TAO and 30 age- and sex-matched healthy subjects and in 40 patients with ASO. FMD was smaller in both the TAO group and ASO group than in the control group (6.6±2.7%, 5.7±3.3% versus 9.5±3.1%, P <0.0001, respectively). There was no significant difference in FMD between the TAO group and ASO group. Nitroglycerine-induced vasodilation was similar in the 3 groups. The number of and migration of circulating CPCs were similar in the TAO group and control group, whereas the number of and migration of circulating CPCs were significantly lower in the ASO group than in other groups (ASO 553±297/mL versus TAO 963±543/mL; control 1063±426/mL and ASO 36±18/hpf versus TAO 62±23/hpf; control 68±18/hpf, P <0.0001, respectively). There was a significant relationship between the number of and migration of CPCs and FMD ( r =0.43 and r =0.40, P <0.0001, respectively). FMD was impaired in patients with TAO as well as in patients with ASO compared to that in normal control subjects, and the number of and function of circulating CPCs were not decreased in patients with TAO. These findings may partially explain why there are differences in cardiovascular morbidity and mortality rates between patients with TAO and patients with ASO.

A pitfall of fractional flow reserve associated with the presence of collateral circulation

An 82-year-old man had a severe stenosis in the proximal left anterior descending artery (LAD) and an intermediate stenosis in the distal right coronary artery (RCA). The territory of mid to distal LAD was perfused via an angiographically well-developed collateral circulation from the distal RCA. Fractional flow reserve (FFR) in the distal RCA was 0.84. After successful coronary intervention for the proximal LAD, repeat FFR in the distal RCA was 0.96. In this case, the severity of the stenosis in the donor artery was overestimated by using FFR due to the presence of well-developed collateral circulation.

Impaired coronary microvascular endothelial function in men with metabolic syndrome

AIM

To assess coronary endothelial function of conduit and resistance vessels in patients with metabolic syndrome (MS).

METHODS

Seventy-eight men (mean age, 57 years) with chest pain and angiographically normal coronary arteries were included in the study. Patients with coronary spastic angina were excluded. Changes in coronary artery diameter and coronary blood flow (CBF) in response to acetylcholine (ACh) were determined using quantitative coronary angiography and Doppler velocity measurements. Coronary flow reserve was calculated as the ratio of coronary blood velocity after adenosine triphosphate infusion relative to baseline values. Patients were divided into two groups based on the presence or absence of MS.

RESULTS

There were 24 patients in the MS group (31%). The increase in CBF in response to ACh infusion was impaired in the MS group (P < 0.0001) compared to the non-MS group, whereas changes in coronary artery diameter in response to ACh infusion did not differ between the two groups. Multivariate regression analysis revealed that MS was a significant factor associated with the lesser change in CBF induced by ACh infusion at 30 μg/min (P < 0.0001, r(2) = 0.46).

CONCLUSION

Coronary endothelial dysfunction was present at the level of resistance vessels but not conduit vessels in the MS patients included in our study.

Selegiline, an MAO-B inhibitor, attenuates airway smooth muscle contraction in the rat trachea

Selegiline is widely used for Parkinson's disease and sometimes for Alzheimer's disease. It is reported to affect intracellular Ca2+ concentration. Since intracellular Ca2+ is partly regulated by phosphatidylinositol (PI) response and is important for smooth muscle contraction, selegiline may affect airway smooth muscle tension. We examined the effects of selegiline on acetylcholine (ACh)- and KCl-induced contractile and PI responses in rat trachea. The trachea was cut into 3-mm-wide ring segments or 1-mm-wide slices. ACh (3 μM, 50% effective dose) or KCl (40mM) was added, and ring relaxation was induced by the addition of selegiline. Tracheal slices were incubated with [3H]myo-inositol and 3 μM ACh in the presence of selegiline, and [3H]inositol monophosphate (IP1) was measured. Selegiline dose-dependently attenuated ACh- and KCl-induced tracheal ring contractions. Fifty-percent inhibitory doses (ID50) of selegiline against ACh- and KCl-induced contraction were 120±30 μM and 80±20 μM, respectively. Basal and ACh-induced IP1 accumulation were 2.20±0.20 Bq and 7.88±0.23 Bq, respectively, and selegiline at a dose of 1000 μM attenuated ACh-induced IP1 accumulation (5.44±0.30 Bq). These results suggest that selegiline inhibits contractile responses through the inhibition of voltage-operated Ca2+ channels and the PI response.

Unmet needs of patients with Parkinson's disease: interview survey of patients and caregivers

We performed a 20-item questionnaire-based interview of 132 patients with Parkinson's disease (PD): 81 patients with Hoehn & Yahr (H&Y) stage I - III PD, and 51 caregivers of patients with H&Y stage IV - V PD, to evaluate patient and caregiver satisfaction with PD treatment. The survey revealed that PD patients often experience non-motor symptoms, which are not adequately alleviated by antiparkinsonian agents. Furthermore, PD patients want their physicians to listen to them and take their concerns seriously, to explain their disease comprehensively, and to provide the latest information on PD and its treatment. Both patients and caregivers agreed on anxiety toward the future, communication difficulties, and their different movement pace; however, there were differences in their relative perceptions of various aspects of daily care. The evaluation revealed that PD patients have unmet needs in their treatment and standards of care. Areas for future improvement as highlighted in this study include: the development of better treatment for motor symptoms, the development of new treatments for non-motor symptoms and improved two-way communication between patient and physician.

Long-term prognosis of late spontaneous reperfusion after failed thrombolysis for acute myocardial infarction

BACKGROUND

Early reperfusion improves left ventricular (LV) function and survival after acute myocardial infarction (MI). Thrombolytic therapy achieves early patency of the infarct artery in about two-thirds of patients. In nearly half of the remaining patients, in whom early reperfusion was not achieved with thrombolytic therapy, the infarct artery might reopen by the time of predischarge angiography. However, the impact of such late spontaneous reperfusion after failed thrombolytic therapy on LV function and long-term survival remained unclear.

HYPOTHESIS

This study was undertaken to assess implication of late spontaneous reperfusion after failed thrombolytic therapy on LV function and long-term survival after acute MI.

METHODS

The study consisted of 198 patients with anterior acute MI who underwent thrombolytic therapy and predischarge angiography: 160 patients with infarct artery patent early and late after therapy (persistent patency), 17 patients with infarct artery occluded early after therapy but patent at predischarge angiography (late spontaneous reperfusion), and 21 patients with infarct artery occluded early and late after therapy (persistent occlusion).

RESULTS

Persistent patency was associated with enhanced improvement in LV ejection fraction (7.7 +/- 11.8%) compared with late spontaneous reperfusion (0.0 +/- 9.6%, p = 0.03) and persistent occlusion (-1.4 +/- 9.7%, p = 0.003). Persistent patency was associated with better long-term survival than with late spontaneous reperfusion (p < 0.001) and persistent occlusion (p < 0.001). Multivariate analysis comparing persistent patency and late spontaneous reperfusion showed that early reperfusion was an independent predictor of long-term survival.

CONCLUSION

Late spontaneous reperfusion after failed thrombolytic therapy was associated with poor LV function and long-term survival, emphasizing the importance of early reperfusion.

Relationship between augmentation index and flow-mediated vasodilation in the brachial artery

Recent studies have shown that the augmentation index (AI) is a predictor of cardiovascular complications. Endothelial dysfunction is the initial step in the pathogenesis of atherosclerosis, which in turn can lead to cardiovascular complications. Endothelial function assessed by flow-mediated dilation (FMD) can serve as an independent predictor of cardiovascular events. However, there is little information on the relationship between AI and FMD in the human vasculature, and we therefore investigated this relationship in the present study. A total of 100 subjects (71 males and 29 females; age range, 22-88 years; mean age, 59 +/- 17 years), including 83 patients with cardiovascular diseases (e.g., atherosclerosis, hypertension, coronary heart disease, stroke and peripheral arterial disease) and 17 healthy subjects were enrolled. High-resolution ultrasonography (automated vessel-diameter measurements; eTRACKING system), a linear array transducer (13 MHz) and an arm holding device were used to measure the arterial diameter response to reactive hyperemia and sublingual nitroglycerine (NTG, 75 micrograms) in all subjects. AI measured using an automated device was significantly correlated with FMD (r = -0.38, p < 0.0001). There was no significant correlation between AI and vascular response to NTG. Multiple regression analysis showed that FMD was a significant independent predictor of AI (p < 0.05). These findings suggest that increase in arterial stiffness may be associated with grade of endothelial dysfunction and that AI may be an index of not only arterial stiffness but also endothelial function.

Development and characteristics of pannus-like soft tissue in osteoarthritic articular surface in rat osteoarthritis model

OBJECTIVES

Pannus is invasive granulation tissue found on the articular cartilage having rheumatoid arthritis (RA). However, pannus-like tissue has also been found in osteoarthritis (OA). Our previous study showed that pannus-like tissue in OA (OA pannus) was frequently found in human OA samples. The purpose of the study is to investigate the development and the characteristics of OA pannus in a rat OA model.

DESIGN

Ligaments of the knee joint were transected in Wister rats to induce OA. The knee joints were removed at weeks 1, 2, 4 and 6, and subjected to histological study. Samples were stained with hematoxylin and eosin (HE), Safranin-O and immuno-stained for vimentin, CD34, type II collagen and MMP-3. The whole knee joint of OA rats was implanted in SCID mice and kept for a further 3 weeks. Then the histological findings were evaluated in HE sections.

RESULT

OA pannus appeared at week 2 and extend over the articular surface. OA pannus cells were positive for vimentin and/or CD34. At week 6, a part of articular surface was restored with matrix. OA pannus cells expressed MMP-3 as well as type II collagen. Histological study of rat OA knees implanted in SCID mice showed that OA pannus cells filled the joint space and invaded articular cartilage.

CONCLUSIONS

The presence of OA pannus was found in a rat OA model and its features were similar to those in human OA. OA pannus had both catabolic and reparative features, and the latter feature were speculated to be dominant in the later phase of the disease under a certain environmental condition.

Pycnogenol, French maritime pine bark extract, augments endothelium-dependent vasodilation in humans

Pycnogenol, an extract of bark from the French maritime pine, Pinus pinaster Ait., consists of a concentrate of water-soluble polyphenols. Pycnogenol contains the bioflavonoids catechin and taxifolin as well as phenolcarbonic acids. Antioxidants, such as bioflavonoids, enhance endothelial nitric oxide (NO) synthase expression and subsequent NO release from endothelial cells. The purpose of this study was to determine Pycnogenol's effects on endothelium-dependent vasodilation in humans. This was a double-blind, randomized, placebo and active drug study. We evaluated forearm blood flow (FBF) responses to acetylcholine (ACh), an endothelium-dependent vasodilator, and to sodium nitroprusside (SNP), an endothelium-independent vasodilator, in healthy young men before and after 2 weeks of daily oral administration of Pycnogenol (180 mg/day) (n=8) or placebo (n=8). FBF was measured by using strain-gauge plethysmography. Neither the placebo nor Pycnogenol altered forearm or systemic hemodynamics. Pycnogenol, but not placebo, augmented FBF response to ACh, from 13.1 +/- 7.0 to 18.5 +/- 4.0 mL/min per 100 mL tissue (p<0.05). SNP-stimulated vasodilation was similar before and after 2 weeks of treatment in the control and Pycnogenol groups. The administration of N(G)-monomethyl-L-arginine, an NO synthase inhibitor, completely abolished Pycnogenol-induced augmentation of the FBF response to ACh. These findings suggest that Pycnogenol augments endothelium-dependent vasodilation by increasing in NO production. Pycnogenol would be useful for treating various diseases whose pathogeneses involve endothelial dysfunction.

Periodontal infection is associated with endothelial dysfunction in healthy subjects and hypertensive patients

The purpose of this study was to evaluate endothelial function in patients with periodontitis. We evaluated forearm blood flow responses to acetylcholine and sodium nitroprusside in patients with periodontitis who had no other cardiovascular risk factors (32 men; 25+/-3 years of age), in a normal control group (20 men; 26+/-3 years of age), and in hypertensive patients with periodontitis (28 men and 10 women; 56+/-12 years of age) and without periodontitis (control group; 18 men and 6 women; 54+/-13 years of age). Forearm blood flow was measured using strain-gauge plethysmography. Circulating levels of C-reactive protein and interleukin-6 were significantly higher in the periodontitis group than in the control group. Both in healthy and hypertensive subjects, forearm blood flow responses to acetylcholine were significantly smaller in the periodontitis group than in the control group. Sodium nitroprusside-stimulated vasodilation was similar in the 2 groups. Periodontal therapy reduced serum concentrations of C-reactive protein and interleukin-6 and augmented acetylcholine-induced vasodilation in periodontitis patients with and without hypertension. After administration of N(G)-monomethyl-L-arginine, an NO synthase inhibitor, forearm blood flow response to acetylcholine was similar before and after treatment. These findings suggest that periodontitis is associated with endothelial dysfunction in subjects without cardiovascular risk factors, as well as hypertensive patients, through a decrease in NO bioavailability and that systemic inflammation may be, at least in part, a cause of endothelial dysfunction, leading to cardiovascular diseases.

Tryptase enhances release of vascular endothelial growth factor from human osteoarthritic chondrocytes

OBJECTIVE

A contribution of mast cells and its mediators in the pathogenesis of arthritis has been postulated. We aimed to clarify the role of mast cell-derived serine protease tryptase and proteinase activated receptor (PAR)-2-mediated signaling in chondrocytes.

METHODS

Human articular cartilage specimens were obtained from patients with osteoarthritis (OA), rheumatoid arthritis (RA) and with traumatic fracture without arthritis (PT; as controls) who underwent joint surgery. Isolated chondrocytes were cultured in vitro by monolayer, and confluent cells were incubated with recombinant human lung Beta tryptase or with a PAR-2 agonist peptide. The secreted level of vascular endothelial growth factor (VEGF) in culture supernatant was measured using commercially available ELISA kits, and expression of VEGF mRNA was analyzed using real-time PCR.

RESULTS

The tryptase-stimulated chondrocytes from OA or RA, but not from PT patients, produced significantly higher amount of VEGF in their supernatants. The response was blocked by a G-protein receptor inhibitor pertussis toxin, however, was not reproduced by incubation of cells with the PAR-2 agonist, suggesting a presence of non-PAR-2 dependent signals for the VEGF induction. In addition, actinomycin D and cycloheximide did not exert significant inhibition, indicating a regulation of VEGF release by tryptase.

CONCLUSION

The inflammatory mediator, mast cell-derived protease tryptase may modulate chondrocyte metabolism through induction of VEGF release.

Acute moderate-intensity exercise induces vasodilation through an increase in nitric oxide bioavailiability in humans

BACKGROUND

Long-term moderate-intensity exercise augments endothelium-dependent vasodilation through an increase in nitric oxide (NO) production. The purpose of this study was to determine the effects of different intensities of acute exercise on hemodynamics in humans.

METHODS

We evaluated forearm blood flow (FBF) responses to different intensities of exercise (mild, 25% maximum oxygen consumption [VO2max]; moderate, 50% VO2max; and high, 75% VO2max; bicycle ergometer, for 30 min) in eight healthy young men. The FBF was measured by using a strain-gauge plethysmography.

RESULTS

After exercise began, moderate-intensity exercise, but not mild-intensity exercise, promptly increased FBF from 2.8+/-1.1 mL/min/100 mL to a plateau at 5.4+/-1.6 mL/min/100 mL at 5 min (P<.01) and increased mean arterial pressure from 84.7+/-11.8 mm Hg to a plateau at 125.7+/-14.3 mm Hg at 5 min (P<.01). Moderate-intensity exercise decreased forearm vascular resistance (FVR) from 29.2+/-5.4 to 16.8+/-3.2 mm Hg/mL/min/100 mL tissue (P<.01). The administration of NG-monomethyl-L-arginine, an NO synthase inhibitor, abolished moderate exercise-induced augmentation of vasodilation. Although we were not able to measure FBF during high-intensity exercise because of large body motion, high-intensity exercise markedly increased mean arterial pressure from 82.6+/-12.2 to 146.8+/-19.8 mm Hg. High-intensity exercise, but not mild-intensity or moderate-intensity exercise, increased plasma concentration of 8-isoprostane, an index of oxidative stress, from 24.1+/-10.8 to 40.2+/-16.7 pg/mL (P<.05) at 10 min after the end of exercise.

CONCLUSIONS

These findings suggest that acute moderate-intensity exercise induces vasodilation through an increase in NO bioavailability in humans and that high-intensity exercise increases oxidative stress.