Alterations of Neuromuscular Function after the World's Most Challenging Mountain Ultra-Marathon

We investigated the physiological consequences of the most challenging mountain ultra-marathon (MUM) in the world: a 330-km trail run with 24000 m of positive and negative elevation change. Neuromuscular fatigue (NMF) was assessed before (Pre-), during (Mid-) and after (Post-) the MUM in experienced ultra-marathon runners (n = 15; finish time  = 122.43 hours ±17.21 hours) and in Pre- and Post- in a control group with a similar level of sleep deprivation (n = 8). Blood markers of muscle inflammation and damage were analyzed at Pre- and Post-. Mean ± SD maximal voluntary contraction force declined significantly at Mid- (−13±17% and −10±16%, P<0.05 for knee extensor, KE, and plantar flexor muscles, PF, respectively), and further decreased at Post- (−24±13% and −26±19%, P<0.01) with alteration of the central activation ratio (−24±24% and −28±34% between Pre- and Post-, P<0.05) in runners whereas these parameters did not change in the control group. Peripheral NMF markers such as 100 Hz doublet (KE: −18±18% and PF: −20±15%, P<0.01) and peak twitch (KE: −33±12%, P<0.001 and PF: −19±14%, P<0.01) were also altered in runners but not in controls. Post-MUM blood concentrations of creatine kinase (3719±3045 Ul·¹), lactate dehydrogenase (1145±511 UI·L⁻¹), C-Reactive Protein (13.1±7.5 mg·L⁻¹) and myoglobin (449.3±338.2 µg·L⁻¹) were higher (P<0.001) than at Pre- in runners but not in controls. Our findings revealed less neuromuscular fatigue, muscle damage and inflammation than in shorter MUMs. In conclusion, paradoxically, such extreme exercise seems to induce a relative muscle preservation process due likely to a protective anticipatory pacing strategy during the first half of MUM and sleep deprivation in the second half.     

Acute electromyostimulation Decreases Muscle Sympathetic Nerve Activity in Patients with Advanced Chronic Heart Failure (EMSICA Study)

Background

Muscle passive contraction of lower limb by neuromuscular electrostimulation (NMES) is frequently used in chronic heart failure (CHF) patients but no data are available concerning its action on sympathetic activity. However, Transcutaneous Electrical Nerve Stimulation (TENS) is able to improve baroreflex in CHF. The primary aim of the present study was to investigate the acute effect of TENS and NMES compared to Sham stimulation on sympathetic overactivity as assessed by Muscle Sympathetic Nerve Activity (MSNA).

Methods

We performed a serie of two parallel, randomized, double blinded and sham controlled protocols in twenty-two CHF patients in New York Heart Association (NYHA) Class III. Half of them performed stimulation by TENS, and the others tested NMES.

Results

Compare to Sham stimulation, both TENS and NMES are able to reduce MSNA (63.5 ± 3.5 vs 69.7 ± 3.1 bursts / min, p < 0.01 after TENS and 51.6 ± 3.3 vs 56.7 ± 3.3 bursts / min, p < 0, 01 after NMES). No variation of blood pressure, heart rate or respiratory parameters was observed after stimulation.

Conclusion

The results suggest that sensory stimulation of lower limbs by electrical device, either TENS or NMES, could inhibit sympathetic outflow directed to legs in CHF patients. These properties could benefits CHF patients and pave the way for a new non-pharmacological approach of CHF.     

SDF1-A Facilitates Lin?/Sca1+ Cell Homing following Murine Experimental Cerebral Ischemia

Background

Hematopoietic stem cells mobilize to the peripheral circulation in response to stroke. However, the mechanism by which the brain initiates this mobilization is uncharacterized.

Methods

Animals underwent a murine intraluminal filament model of focal cerebral ischemia and the SDF1-A pathway was evaluated in a blinded manner via serum and brain SDF1-A level assessment, Lin−/Sca1+ cell mobilization quantification, and exogenous cell migration confirmation; all with or without SDF1-A blockade.

Results

Bone marrow demonstrated a significant increase in Lin−/Sca1+ cell counts at 24 hrs (272±60%; P<0.05 vs sham). Mobilization of Lin−/Sca1+ cells to blood was significantly elevated at 24 hrs (607±159%; P<0.05). Serum SDF1-A levels were significant at 24 hrs (Sham (103±14), 4 hrs (94±20%, p = NS) and 24 hrs (130±17; p<0.05)). Brain SDF1-A levels were significantly elevated at both 4 hrs and 24 hrs (113±7 pg/ml and 112±10 pg/ml, respectively; p<0.05 versus sham 76±11 pg/ml). Following administration of an SDF1-A antibody, Lin−/Sca1+ cells failed to mobilize to peripheral blood following stroke, despite continued up regulation in bone marrow (stroke bone marrow cell count: 536±65, blood cell count: 127±24; p<0.05 versus placebo). Exogenously administered Lin−/Sca1+ cells resulted in a significant reduction in infarct volume: 42±5% (stroke alone), versus 21±15% (Stroke+Lin−/Sca1+ cells), and administration of an SDF1-A antibody concomitant to exogenous administration of the Lin−/Sca1+ cells prevented this reduction. Following stroke, exogenously administered Lin−/Sca1+ FISH positive cells were significantly reduced when administered concomitant to an SDF1-A antibody as compared to without SDF1-A antibody (10±4 vs 0.7±1, p<0.05).

Conclusions

SDF1-A appears to play a critical role in modulating Lin−/Sca1+ cell migration to ischemic brain.     

Antenatal Dexamethasone after Asphyxia Increases Neural Injury in Preterm Fetal Sheep

Background and Purpose

Maternal glucocorticoid treatment for threatened premature delivery dramatically improves neonatal survival and short-term morbidity; however, its effects on neurodevelopmental outcome are variable. We investigated the effect of maternal glucocorticoid exposure after acute asphyxia on injury in the preterm brain.

Methods

Chronically instrumented singleton fetal sheep at 0.7 of gestation received asphyxia induced by complete umbilical cord occlusion for 25 minutes. 15 minutes after release of occlusion, ewes received a 3 ml i.m. injection of either dexamethasone (12 mg, n = 10) or saline (n = 10). Sheep were killed after 7 days recovery; survival of neurons in the hippocampus and basal ganglia, and oligodendrocytes in periventricular white matter were assessed using an unbiased stereological approach.

Results

Maternal dexamethasone after asphyxia was associated with more severe loss of neurons in the hippocampus (CA3 regions, 290±76 vs 484±98 neurons/mm², mean±SEM, P<0.05) and basal ganglia (putamen, 538±112 vs 814±34 neurons/mm², P<0.05) compared to asphyxia-saline, and with greater loss of both total (913±77 vs 1201±75/mm², P<0.05) and immature/mature myelinating oligodendrocytes in periventricular white matter (66±8 vs 114±12/mm², P<0.05, vs sham controls 165±10/mm², P<0.001). This was associated with transient hyperglycemia (peak 3.5±0.2 vs. 1.4±0.2 mmol/L at 6 h, P<0.05) and reduced suppression of EEG power in the first 24 h after occlusion (maximum −1.5±1.2 dB vs. −5.0±1.4 dB in saline controls, P<0.01), but later onset and fewer overt seizures.

Conclusions

In preterm fetal sheep, exposure to maternal dexamethasone during recovery from asphyxia exacerbated brain damage.     

Soluble Tumor Necrosis Factor Related Apoptosis Inducing Ligand Level as a Predictor of Severity of Sepsis and the Risk of Mortality in Septic Patients

Background

Tumor necrosis factor related apoptosis inducing ligand (TRAIL) as a member of the TNF gene superfamily induces apoptosis primarily in tumor cells. TRAIL also plays an important role in the modulation of inflammatory responses, especially in the process of immune paralysis. The aim of the present study was to examine soluble TRAIL (sTRAIL) levels in septic patients in an attempt to explore the association between sTRAIL level and the risk of mortality.

Methods

Plasma sTRAIL levels were detected by ELISA in 50 septic patients and 20 healthy volunteers. HLA-DR expression in monocytes was detected by flow cytometry. Selective biochemical parameters were recorded, and patients were monitored in a 28-day period for mortality.

Results

The mean plasma sTRAIL level in septic patients was significantly lower than that in healthy controls (16.9±8.3 vs. 68.3±8.6 pg/ml, P<0.01), and was significantly higher in 28-day survivors than those in non-survivors (19.4±9.8 vs. 13.9±4.7 pg/ml, P<0.05). Univariate analysis indicated that plasma sTRAIL level was positively correlated with monocyte and lymphocyte counts and HLA-DR expression level (r = 0.5, P<0.01; r = 0.3, P<0.05; r = 0.43, P<0.01, respectively). STRAIL level was negatively correlated with APACHE II score, BUN and age (r = −0.48, P<0.01; r = −0.29, P<0.05; r = −0.45, P<0.01, respectively). Multiple linear regression analysis indicated that the predictor of plasma soluble TRAIL level was HLA-DR expression (P<0.01).

Conclusion

Low plasma sTRAIL levels were associated with immune paralysis and a high risk of mortality in patients with septic shock. sTRAIL may prove to be a potential biomarker of immune function and predict the survival of septic patients.     

Impact of Untreated Obstructive Sleep Apnea on Left and Right Ventricular Myocardial Function and Effects of CPAP Therapy

Background

Obstructive sleep apnea (OSA) has deteriorating effect on LV function, whereas its impact on RV function is controversial. We aimed to determine the effect of OSA and continuous positive airway pressure (CPAP) treatment on left and right ventricular (LV, RV) function using transthoracic echocardiography (TTE) and 2 dimensional speckle tracking (2D ST) analysis of RV deformation capability.

Methods and Results

82 patients with OSA and need for CPAP therapy were prospectively enrolled and underwent TTE at study inclusion and after 6 months of follow up (FU). Multivariate regression analysis revealed an independent association between baseline apical right ventricular longitudinal strain (RV-Sl), BMI and the severity of OSA (apical RV-Sl: P = 0.0002, BMI: P = 0.02). After CPAP therapy, LV functional parameters (LVEF: P<0.0001, LV performance index: P = 0.03, stroke volume: P = 0.042), and apical RV-Sl (P = 0.001) improved significantly. The effect of CPAP therapy was related to severity of OSA (LVEF: AHI 5–14, 66.4±8.8%, 68.5±10.6% [P = ns]; AHI 15–30∶59.8±7.7%, 68.6±9.3% [P = 0.002]; AHI>30∶54.1±12.4%, 68.2±13.6%[P<0.0001]; apical RV-Sl: AHI 5–14: −17.3±8.7%, −16.0±10.8% [P = ns], AHI 15–30: −9.8±6.0%, −15.4±10.9% [P = 0.028], AHI>30: −6.3±5.7%, −17.9±11.2% [P<0.0001]).

Conclusions

OSA seems to have deteriorating effect on LV and RV function. We found a beneficial effect of CPAP on LV and RV functional parameters predominately in patients with severe OSA. 2D speckle tracking might be of value to determine early changes in global and regional right ventricular function.     

Metabolomics Reveals Metabolic Targets and Biphasic Responses in Breast Cancer Cells Treated by Curcumin Alone and in Association with Docetaxel

Background

Curcumin (CUR) has deserved extensive research due to its anti-inflammatory properties, of interest in human diseases including cancer. However, pleiotropic even paradoxical responses of tumor cells have been reported, and the mechanisms of action of CUR remain uncompletely elucidated.

Methodology/Principal Findings

¹H-NMR spectroscopy-based metabolomics was applied to get novel insight into responses of MCF7 and MDA-MB-231 breast cancer cells to CUR alone, and MCF7 cells to CUR in cotreatment with docetaxel (DTX). In both cell types, a major target of CUR was glutathione metabolism. Total glutathione (GSx) increased at low dose CUR (≤ 10 mg.l⁻¹–28 µM-) (up to +121% in MCF7 cells, P<0.01, and +138% in MDA-MB-231 cells, P<0.01), but decreased at high dose (≥ 25 mg.l⁻¹ −70 µM-) (−49%, in MCF7 cells, P<0.02, and −56% in MDA-MB-231 cells, P<0.025). At high dose, in both cell types, GSx-related metabolites decreased, including homocystein, creatine and taurine (−60 to −80%, all, P<0.05). Together with glutathione-S-transferase actvity, data established that GSx biosynthesis was upregulated at low dose, and GSx consumption activated at high dose. Another major target, in both cell types, was lipid metabolism involving, at high doses, accumulation of polyunsaturated and total free fatty acids (between ×4.5 and ×11, P<0.025), and decrease of glycerophospho-ethanolamine and -choline (about −60%, P<0.025). Multivariate statistical analyses showed a metabolic transition, even a biphasic behavior of some metabolites including GSx, between low and high doses. In addition, CUR at 10 mg.l⁻¹ in cotreatment with DTX induced modifications in glutathione metabolism, lipid metabolism, and glucose utilization. Some of these changes were biphasic depending on the duration of exposure to CUR.

Conclusions/Significance

Metabolomics reveals major metabolic targets of CUR in breast cancer cells, and biphasic responses that challenge the widely accepted beneficial effects of the phytochemical.     

Leukocytosis and Enhanced Susceptibility to Endotoxemia but Not Atherosclerosis in Adrenalectomized APOE Knockout Mice

Hyperlipidemic apolipoprotein E (APOE) knockout mice show an enhanced level of adrenal-derived anti-inflammatory glucocorticoids. Here we determined in APOE knockout mice the impact of total removal of adrenal function through adrenalectomy (ADX) on two inflammation-associated pathologies, endotoxemia and atherosclerosis. ADX mice exhibited 91% decreased corticosterone levels (P<0.001), leukocytosis (WBC count: 10.0 ± 0.4 x 10E9/L vs 6.5 ± 0.5 x 10E9/L; P<0.001) and an increased spleen weight (P<0.01). FACS analysis on blood leukocytes revealed increased B-lymphocyte numbers (55 ± 2% vs 46 ± 1%; P<0.01). T-cell populations in blood appeared to be more immature (CD62L+: 26 ± 2% vs 19 ± 1% for CD4+ T-cells, P<0.001 and 58 ± 7% vs 47 ± 4% for CD8+ T-cells, P<0.05), which coincided with immature CD4/CD8 double positive thymocyte enrichment. Exposure to lipopolysaccharide failed to increase corticosterone levels in ADX mice and was associated with a 3-fold higher (P<0.05) TNF-alpha response. In contrast, the development of initial fatty streak lesions and progression to advanced collagen-containing atherosclerotic lesions was unaffected. Plasma cholesterol levels were decreased by 35% (P<0.001) in ADX mice. This could be attributed to a decrease in pro-atherogenic very-low-density lipoproteins (VLDL) as a result of a diminished hepatic VLDL secretion rate (-24%; P<0.05). In conclusion, our studies show that adrenalectomy induces leukocytosis and enhances the susceptibility for endotoxemia in APOE knockout mice. The adrenalectomy-associated rise in white blood cells, however, does not alter atherosclerotic lesion development probably due to the parallel decrease in plasma levels of pro-atherogenic lipoproteins.     

Short-Term Intensified Cycle Training Alters Acute and Chronic Responses of PGC1α and Cytochrome C Oxidase IV to Exercise in Human Skeletal Muscle

Reduced activation of exercise responsive signalling pathways have been reported in response to acute exercise after training; however little is known about the adaptive responses of the mitochondria. Accordingly, we investigated changes in mitochondrial gene expression and protein abundance in response to the same acute exercise before and after 10-d of intensive cycle training. Nine untrained, healthy participants (mean±SD; VO_2peak 44.1±17.6 ml/kg/min) performed a 60 min bout of cycling exercise at 164±18 W (72% of pre-training VO_2peak). Muscle biopsies were obtained from the vastus lateralis muscle at rest, immediately and 3 h after exercise. The participants then underwent 10-d of cycle training which included four high-intensity interval training sessions (6×5 min; 90–100% VO_2peak) and six prolonged moderate-intensity sessions (45–90 min; 75% VO_2peak). Participants repeated the pre-training exercise trial at the same absolute work load (64% of pre-training VO_2peak). Muscle PGC1-α mRNA expression was attenuated as it increased by 11- and 4- fold (P<0.001) after exercise pre- and post-training, respectively. PGC1-α protein expression increased 1.5 fold (P<0.05) in response to exercise pre-training with no further increases after the post-training exercise bout. RIP140 protein abundance was responsive to acute exercise only (P<0.01). COXIV mRNA (1.6 fold; P<0.01) and COXIV protein expression (1.5 fold; P<0.05) were increased by training but COXIV protein expression was decreased (20%; P<0.01) by acute exercise pre- and post-training. These findings demonstrate that short-term intensified training promotes increased mitochondrial gene expression and protein abundance. Furthermore, acute indicators of exercise-induced mitochondrial adaptation appear to be blunted in response to exercise at the same absolute intensity following short-term training.     

The anti-inflammatory effects of exercise training promote atherosclerotic plaque stabilization in apolipoprotein E knockout mice with diabetic atherosclerosis

Physical exercise is the cornerstone of cardiovascular disease treatment. The present study investigated whether exercise training affects atherosclerotic plaque composition through the modification of inflammatoryrelated pathways in apolipoprotein E knockout (apoE^−/−) mice with diabetic atherosclerosis. Forty-five male apoE^−/− mice were randomized into three equivalent (n=15) groups: control (CO), sedentary (SED), and exercise (EX). Diabetes was induced by streptozotocin administration. High-fat diet was administered to all groups for 12 weeks. Afterwards, CO mice were euthanatized, while the sedentary and exercise groups continued high-fat diet for 6 additional weeks. Exercising mice followed an exercise program on motorizedtreadmill (5 times/week, 60 min/session). Then, blood samples and atherosclerotic plaques in the aortic root were examined. A considerable (P<0.001) regression of the atherosclerotic lesions was observed in the exercise group (180.339±75.613×10³µm²) compared to the control (325.485±72.302×10³ µm²) and sedentary (340.188±159.108×10³µm²) groups. We found decreased macrophages, matrix metalloproteinase-2 (MMP-2), MMP-3, MMP-8 and interleukin-6 (IL-6) concentrations (P<0.05) in the atherosclerotic plaques of the exercise group. Compared to both control and sedentary groups, exercise training significantly increased collagen (P<0.05), elastin (P<0.001), and tissue inhibitor of matrix metalloproteinase-2 (TIMP-2) (P<0.001) content in the atherosclerotic plaques. Those effects paralleled with increased fibrous cap thickness and less internal elastic lamina ruptures after exercise training (P<0.05), while body-weight and lipid parameters did not significantly change. Plasma MMP-2 and MMP-3 concentrations in atherosclerotic tissues followed a similar trend. From our study we can conclude that exercise training reduces and stabilizes atherosclerotic lesions in apoE^−/− mice with diabetic atherosclerosis. A favorable modification of the inflammatory regulators seems to explain those beneficial effects.Key words: diabetes, atherosclerosis, exercise, matrix metalloproteinases, plaque stability.     

Protective role of scutellarin on LPS induced – Acute lung injury and regulation of apoptosis,oxidative stress and reduction of mitochondrial dysfunction

Lung fluid accumulation was determined using wet/dry lung mass ratio. Rats subjected to LPS-induced acute lung injury (2.8 ± 0.33, P < 0.05) presented with a significantly higher wet to dry lung weight ration ratio than sham rats (1.6 ± 0.23, P < 0.05). These results demonstrate that acutely inured rats'' lungs were oedematous. On the other hand, treatment with scutellarin alone and in combination with a JNK inhibitor, SP600125, both significantly attenuated pulmonary edema as shown via reduced wet/dry lung mass ratios (1.7 ± 0.09 and 1.8 ± 0.23; P < 0.05, respectively). These results showed that the interventions were effective against LPS-induced edema of the lungs. However, the difference between treatment groups'' weight ratios was not statistically significant (P > 0.05). In the sham control rats, the levels of ROS and SOD production were maintained at a low and at a high concentration, respectively (P < 0.05). However, following LPS infusion, the ROS levels skyrocketed while that of SOD decreased significantly relative to the control rats (P < 0.05). Furthermore, we noted that pre-treatment with scutellarin reduced the ROS levels in LPS-injured rats while the SOD was increased to near control levels (P < 0.05). Moreover, the combined effect of scutellarin and JNK inhibitor SP600125 on the levels of ROS and the SOD activity followed a similar trend to that of scutellarin alone albeit with a lower magnitude of change. Our results also showed that the combinatorial treatment was not significantly different from scutellarin alone in terms of influence on the levels of ROS production and SOD activity (P > 0.05). The effect of Scutellarin on broncho-alveolar lavage fluid (BALF) cytokine secretion The expression of interleukins-1β, −18 and −6 in the broncho-alveolar lavage fluid were significantly upregulated by LPS infusion (P < 0.05). The rise was, however, attenuated via pre-treatment with scutellarin only or in conjunction with SP600125, a JNK inhibitor (all P < 0.05). On the contrary, we observed that LPS injection caused a reduction of interlekins −4 and −10 secreted in the BALF. Pre-treatment with scutellarin alone (P < 0.05) and not in combination with SP600125 or SP600125 was able to significantly reverse this noted down-regulation (all P > 0.05).     

Caffeine Impairs Myocardial Blood Flow Response to Physical Exercise in Patients with Coronary Artery Disease as well as in Age-Matched Controls

Background

Caffeine is one of the most widely consumed pharmacologically active substances. Its acute effect on myocardial blood flow is widely unknown. Our aim was to assess the acute effect of caffeine in a dose corresponding to two cups of coffee on myocardial blood flow (MBF) in coronary artery disease (CAD).

Methodology/Principal Findings

MBF was measured with ¹⁵O-labelled H2O and Positron Emission Tomography (PET) at rest and after supine bicycle exercise in controls (n = 15, mean age 58±13 years) and in CAD patients (n = 15, mean age 61±9 years). In the latter, regional MBF was assessed in segments subtended by stenotic and remote coronary arteries. All measurements were repeated fifty minutes after oral caffeine ingestion (200 mg). Myocardial perfusion reserve (MPR) was calculated as ratio of MBF during bicycle stress divided by MBF at rest. Resting MBF was not affected by caffeine in both groups. Exercise-induced MBF response decreased significantly after caffeine in controls (2.26±0.56 vs. 2.02±0.56, P<0.005), remote (2.40±0.70 vs. 1.78±0.46, P<0.001) and in stenotic segments (1.90±0.41 vs. 1.38±0.30, P<0.001). Caffeine decreased MPR significantly by 14% in controls (P<0.05 vs. baseline). In CAD patients MPR decreased by 18% (P<0.05 vs. baseline) in remote and by 25% in stenotic segments (P<0.01 vs. baseline).

Conclusions

We conclude that caffeine impairs exercise-induced hyperaemic MBF response in patients with CAD to a greater degree than age-matched controls.     

Focus: Allergic Diseases and Type II Immunity: Study of the Correlation between HRCT Semi-quantitative Scoring, Concentration of Alveolar Nitric Oxide,and Clinical-functional Parameters of Systemic Sclerosis-induced Interstitial Lung Disease

Introduction: The correlation between alveolar nitric oxide (CANO) and the severity of interstitial lung disease (ILD) evaluated by high resolution computed tomography (HRCT) has not been well demonstrated. Methods: It was a perspective and observational study, including patients with diagnosed systemic sclerosis (SSc). They performed lung function testing (LFT), exhaled nitric oxide (NO) measurements, exercise testing, chest X-ray, and HRCT. Study patients were divided into SSc with ILD (SSc-ILD+) or without ILD (SSc-ILD-). SSC-ILD+ patients were revisited after 6 months and 12 months to complete the study. Results: Thirty-one control subjects and 74 patients with SSc (33 SSc-ILD- and 41 SSc-ILD+) were included. Forty-one SSc-ILD+ patients were followed-up at 6 months and 12 months. Lung functional parameters of patients with SSc-ILD+ were lower than that of SSc-ILD- patients. The level of CANO was significantly higher in SSc-ILD+ than SSc-ILD- patients (8.6 ± 2.5 vs 4.2 ± 1.3 ppb and P<0.01). Warrick and Goldin scores of patients with SSc-ILD+ were respectively 16.5 ± 5.2 and 12.7 ± 4.3. Warrick scores were reduced after 6 and 12 months of follow-up vs at inclusion (12.4 ± 4.3 and 9.1 ± 3.2 vs 16.5 ± 5.2; P<0.05, P<0.01, and P<0.05; respectively). ΔWarrick and ΔGoldin scores were significantly and inversely correlated with ΔFVC, ΔTLC, ΔTLCO, ΔVO₂ max; that was also correlated with ΔCANO (R= 0.783, P<0.01 and R= 0.719 and P<0.05). Conclusion: CANO is a relevant biomarker for the diagnosis of ILD in patients with SSc, especially in combination with HRCT.     

Intraocular Pressure and Estimated Cerebrospinal Fluid Pressure. The Beijing Eye Study 2011

Purpose

To examine a potential association between intraocular pressure (IOP) and cerebrospinal fluid pressure (CSFP) in a population-based setting.

Methods

The population-based Beijing Eye Study 2011 included 3468 individuals with a mean age of 64.6±9.8 years (range: 50–93 years). A detailed ophthalmic examination was performed. Based on a previous study with lumbar cerebrospinal fluid pressure (CSFP) measurements, CSFP was calculated as CSFP [mm Hg] = 0.44×Body Mass Index [kg/m²]+0.16×Diastolic Blood Pressure [mm Hg]–0.18×Age [Years].

Results

In multivariate analysis, IOP was associated with higher estimated CSFP (P<0.001; standardized correlation coefficient beta: 0.27; regression coefficient B: 0.20; 95% confidence interval (CI): 0.16, 0.24), after adjusting for thinner central corneal thickness (P<0.001; beta: 0.45; B: 0.04;95%CI: 0.04,0.04), smaller corneal curvature radius (P<0.001; beta:−0.11; B:−1.13;95%CI:−1.61,−0.64), shallower anterior chamber depth (P = 0.01; beta:−0.05; B:−0.33;95%CI:−0.59,−0.08) and longer axial length (P = 0.002; beta: 0.08; B: 0.20;95%CI: 0.08,0.32)), and after adjusting for the systemic parameters of higher pulse rate (P<0.001; beta: 0.08; B: 0.02;95%CI: 0.01,0.03), higher prevalence of arterial hypertension (P = 0.002; beta: 0.06; B: 0.32;95%CI: 0.12,0.53)), frequency of drinking alcohol (P = 0.02; beta: 0.04; B: 0.09;95%CI: 0.01,0.17), higher blood concentration of triglycerides (P = 0.001; beta: 0.06; B: 0.06;95%CI: 0.02,0.10) and cholesterol (P = 0.049; beta: 0.04; B: 0.08;95%CI: 0.00,0.17), and body mass index (P<0.001; beta:−0.13; B:−0.09;95%CI:−0.13,−0.06). In a parallel manner, estimated CSFP (mean: 10.8±3.7 mm Hg) was significantly associated with higher IOP (P<0.001; beta: 0.13; B: 0.18;95%CI: 0.13,0.23) after adjusting for rural region of habitation (P<0.001; beta:−0.37; B:−2.78;95%CI:−3.07,−2.48), higher systolic blood pressure (P<0.001; beta: 0.34; B: 0.06;95%CI: 0.05,0.07), higher pulse rate (P = 0.003; beta: 0.05; B: 0.02;95%CI: 0.01,0.03), taller body height (P<0.001; beta: 0.11; B: 0.05;95%CI: 0.03,0.07), higher blood concentration of cholesterol (P = 0.003; beta: 0.05; B: 0.17;95%CI: 0.06,0.28) and higher level of education (P = 0.003; beta: 0.09; B: 0.30;95%CI: 0.16,0.45).

Conclusions

IOP was positively associated with estimated CSFP after adjusting for other ocular and systemic parameters. As a corollary, higher estimated CSFP was significantly associated with higher IOP in multivariate analysis. It fits with the notion that the arterial blood pressure, estimated CSFP and IOP are physiologically correlated with each other.     

Acquired defects in CFTR-dependent β-adrenergic sweat secretion in chronic obstructive pulmonary disease

Rationale

Smoking-induced chronic obstructive pulmonary disease (COPD) is associated with acquired systemic cystic fibrosis transmembrane conductance regulator (CFTR) dysfunction. Recently, sweat evaporimetry has been shown to efficiently measure β-adrenergic sweat rate and specifically quantify CFTR function in the secretory coil of the sweat gland.

Objectives

To evaluate the presence and severity of systemic CFTR dysfunction in smoking-related lung disease using sweat evaporimetry to determine CFTR-dependent sweat rate.

Methods

We recruited a cohort of patients consisting of healthy never smokers (N = 18), healthy smokers (12), COPD smokers (25), and COPD former smokers (12) and measured β-adrenergic sweat secretion rate with evaporative water loss, sweat chloride, and clinical data (spirometry and symptom questionnaires).

Measurements and main results

β-adrenergic sweat rate was reduced in COPD smokers (41.9 ± 3.4, P < 0.05, ± SEM) and COPD former smokers (39.0 ± 5.4, P < 0.05) compared to healthy controls (53.6 ± 3.4). Similarly, sweat chloride was significantly greater in COPD smokers (32.8 ± 3.3, P < 0.01) and COPD former smokers (37.8 ± 6.0, P < 0.01) vs. healthy controls (19.1 ± 2.5). Univariate analysis revealed a significant association between β-adrenergic sweat rate and female gender (β = 0.26), age (−0.28), FEV₁% (0.35), dyspnea (−0.3), and history of smoking (−0.27; each P < 0.05). Stepwise multivariate regression included gender (0.39) and COPD (−0.43) in the final model (R² = 0.266, P < 0.0001).

Conclusions

β-adrenergic sweat rate was significantly reduced in COPD patients, regardless of smoking status, reflecting acquired CFTR dysfunction and abnormal gland secretion in the skin that can persist despite smoking cessation. β-adrenergic sweat rate and sweat chloride are associated with COPD severity and clinical symptoms, supporting the hypothesis that CFTR decrements have a causative role in COPD pathogenesis.     

Loss of PINK1 Increases the Heart's Vulnerability to Ischemia-Reperfusion Injury

Objectives

Mutations in PTEN inducible kinase-1 (PINK1) induce mitochondrial dysfunction in dopaminergic neurons resulting in an inherited form of Parkinson’s disease. Although PINK1 is present in the heart its exact role there is unclear. We hypothesized that PINK1 protects the heart against acute ischemia reperfusion injury (IRI) by preventing mitochondrial dysfunction.

Methods and Results

Over-expressing PINK1 in HL-1 cardiac cells reduced cell death following simulated IRI (29.2±5.2% PINK1 versus 49.0±2.4% control; N = 320 cells/group P<0.05), and delayed the onset of mitochondrial permeability transition pore (MPTP) opening (by 1.3 fold; P<0.05). Hearts excised from PINK1+/+, PINK1+/− and PINK1−/− mice were subjected to 35 minutes regional ischemia followed by 30 minutes reperfusion. Interestingly, myocardial infarct size was increased in PINK1−/− hearts compared to PINK1+/+ hearts with an intermediate infarct size in PINK1+/− hearts (25.1±2.0% PINK1+/+, 38.9±3.4% PINK1+/− versus 51.5±4.3% PINK1−/− hearts; N>5 animals/group; P<0.05). Cardiomyocytes isolated from PINK1−/− hearts had a lower resting mitochondrial membrane potential, had inhibited mitochondrial respiration, generated more oxidative stress during simulated IRI, and underwent rigor contracture more rapidly in response to an uncoupler when compared to PINK1+/+ cells suggesting mitochondrial dysfunction in hearts deficient in PINK1.

Conclusions

We show that the loss of PINK1 increases the heart''s vulnerability to ischemia-reperfusion injury. This may be due, in part, to increased mitochondrial dysfunction. These findings implicate PINK1 as a novel target for cardioprotection.     

Novel Cell-Free Strategy for Therapeutic Angiogenesis: In Vitro Generated Conditioned Medium Can Replace Progenitor Cell Transplantation

Background

Current evidence suggests that endothelial progenitor cells (EPC) contribute to ischemic tissue repair by both secretion of paracrine factors and incorporation into developing vessels. We tested the hypothesis that cell-free administration of paracrine factors secreted by cultured EPC may achieve an angiogenic effect equivalent to cell therapy.

Methodology/Principal Findings

EPC-derived conditioned medium (EPC-CM) was obtained from culture expanded EPC subjected to 72 hours of hypoxia. In vitro, EPC-CM significantly inhibited apoptosis of mature endothelial cells and promoted angiogenesis in a rat aortic ring assay. The therapeutic potential of EPC-CM as compared to EPC transplantation was evaluated in a rat model of chronic hindlimb ischemia. Serial intramuscular injections of EPC-CM and EPC both significantly increased hindlimb blood flow assessed by laser Doppler (81.2±2.9% and 83.7±3.0% vs. 53.5±2.4% of normal, P<0.01) and improved muscle performance. A significantly increased capillary density (1.62±0.03 and 1.68±0.05/muscle fiber, P<0.05), enhanced vascular maturation (8.6±0.3 and 8.1±0.4/HPF, P<0.05) and muscle viability corroborated the findings of improved hindlimb perfusion and muscle function. Furthermore, EPC-CM transplantation stimulated the mobilization of bone marrow (BM)-derived EPC compared to control (678.7±44.1 vs. 340.0±29.1 CD34⁺/CD45⁻ cells/1×10⁵ mononuclear cells, P<0.05) and their recruitment to the ischemic muscles (5.9±0.7 vs. 2.6±0.4 CD34⁺ cells/HPF, P<0.001) 3 days after the last injection.

Conclusions/Significance

Intramuscular injection of EPC-CM is as effective as cell transplantation for promoting tissue revascularization and functional recovery. Owing to the technical and practical limitations of cell therapy, cell free conditioned media may represent a potent alternative for therapeutic angiogenesis in ischemic cardiovascular diseases.     

The Inter-Arm Diastolic Blood Pressure Difference Induced by One Arm Ischemia: A New Approach to Assess Vascular Endothelia Function

Objectives

To evaluate whether inter-arm diastolic blood pressure difference (DBPl-r) induced by one arm ischemia correlates with flow-mediated dilatation (FMD).

Methods

Bilateral arm BPs were simultaneously measured with two automatic devices and right brachial artery diameter (D) was measured by ultrasound technique in 108 subjects (56 hypertensives and 52 normotensives). Following baseline diameter (D0) and BP measurement, right brachial artery was occluded for 5 minutes. The diameter was measured at 1, 1.5 and 2 min, and bilateral BPs measured at 3, 4 and 5 min after occlusion release. Their averages were recorded as post-D and post-BP, respectively. The difference between post-D and D0 (ΔD) was calculated as the percentage increase of artery diameter (ΔD/D0). The BP difference between left and right arms was calculated as BPl-r, and the difference of post- BPl-r and baseline BPl-r was recorded as the net change of BPl-r (ΔBPl-r).

Results

At baseline, bilateral SBPs and DBPs were similar. Right arm ischemia induced significant DBP decline only in the right arm (68.8±12.7 vs 72.6±12.0 mmHg, P<0.05), which led to an increase of ΔDBPl-r (4.00±3.75 vs 0.78±4.47 mmHg, P<0.05). A positive correlation was seen between ΔD/D0 and ΔDBPl-r (r = 0.744, p<0.001). Furthermore, the correlation between age and ΔDBPl-r (r = −0.358, P<0.01) was similar to that between age and D/D0 (r = −0.398, P<0.01). Meanwhile, both ΔDBPl-r and ΔD/D0 were significantly lower in hypertensive patients than in normotensive patients.

Conclusion

The inter-arm DBP difference induced by one arm ischemia may be a potential index for clinical evaluation of vascular endothelial function.     

Periaortic Brown Adipose Tissue as a Major Determinant of [18F]-Fluorodeoxyglucose Vascular Uptake in Atherosclerosis-Prone,ApoE?/? Mice

Background

[¹⁸F]-fluorodeoxyglucose (FDG) has been suggested for the clinical and experimental imaging of inflammatory atherosclerotic lesions. Significant FDG uptake in brown adipose tissue (BAT) has been observed both in humans and mice. The objective of the present study was to investigate the influence of periaortic BAT on apolipoprotein E-deficient (apoE^−/−) mouse atherosclerotic lesion imaging with FDG.

Methods

ApoE^−/− mice (36±2 weeks-old) were injected with FDG (12±2 MBq). Control animals (Group A, n = 7) were injected conscious and kept awake at room temperature (24°C) throughout the accumulation period. In order to minimize tracer activity in periaortic BAT, Group B (n = 7) and C (n = 6) animals were injected under anaesthesia at 37°C and Group C animals were additionally pre-treated with propranolol. PET/CT acquisitions were performed prior to animal euthanasia and ex vivo analysis of FDG biodistribution.

Results

Autoradiographic imaging indicated higher FDG uptake in atherosclerotic lesions than in the normal aortic wall (all groups, P<0.05) and the blood (all groups, P<0.01) which correlated with macrophage infiltration (R = 0.47; P<0.001). However, periaortic BAT uptake was either significantly higher (Group A, P<0.05) or similar (Group B and C, P = NS) to that observed in atherosclerotic lesions and was shown to correlate with in vivo quantified aortic FDG activity.

Conclusion

Periaortic BAT FDG uptake was identified as a confounding factor while using FDG for the non-invasive imaging of mouse atherosclerotic lesions.