Hypoxia and hyperoxia differentially control proliferation of rat neural crest stem cells via distinct regulatory pathways of the HIF1α-CXCR4 and TP53-TPM1 proteins.

BACKGROUND: Neural crest stem cells (NCSCs) are a population of adult multipotent stem cells. We are interested in studying whether oxygen tensions affect the capability of NCSCs to self-renew and repair damaged tissues. NCSCs extracted from the hair follicle bulge region of the rat whisker pad were cultured in vitro under different oxygen tensions. RESULTS: We found significantly increased and decreased rates of cell proliferation in rat NCSCs (rNCSCs) cultured, respectively, at 0.5% and 80% oxygen levels. At 0.5% oxygen, the expression of both hypoxia-inducible factor (HIF) 1α and CXCR4 was greatly enhanced in the rNCSC nuclei and was suppressed by incubation with the CXCR4-specific antagonist AMD3100. In addition, the rate of cell apoptosis in the rNCSCs cultured at 80% oxygen was dramatically increased, associated with increased nuclear expression of TP53, decreased cytoplasmic expression of TPM1 (tropomyosin-1), and increased nuclear-to-cytoplasmic translocation of S100A2. Incubation of rNCSCs with the antioxidant N-acetylcysteine (NAC) overcame the inhibitory effect of 80% oxygen on proliferation and survival of rNCSCs. CONCLUSIONS: Our results show for the first time that extreme oxygen tensions directly control NCSC proliferation differentially via distinct regulatory pathways of proteins, with hypoxia via the HIF1α-CXCR4 pathway and hyperoxia via the TP53-TPM1 pathway. Developmental Dynamics 246:162-185, 2017. © 2016 Wiley Periodicals, Inc.

Ultrasound-guided pulsed radiofrequency stimulation of the suprascapular nerve for adhesive capsulitis: a prospective, randomized, controlled trial.

BACKGROUND: The treatment of adhesive capsulitis (AC) is a well-known, complicated, and long process. Recent studies have shown that pulsed radiofrequency (PRF) lesioning of the suprascapular nerve (SSN) using a fluoroscopy- or computed tomography-guided technique can alleviate shoulder pain. However, there are no studies of PRF lesioning of the SSN in patients with AC using ultrasound-guided (UG) techniques, except for 2 case reports. In this study, we compared the effect of physical therapy alone with physical therapy and PRF lesioning of the SSN using a UG technique. METHODS: Sixty patients with AC were included in the study. Patients were randomized into the following 2 groups: the intervention group containing patients who received 12 weeks of physical therapy after 1 treatment of PRF lesioning of the SSN, and the control group containing patients who received 12 weeks of physical therapy alone. All outcome measurements including visual analog scale (VAS), shoulder pain and disability index, and passive range of motion (PROM) were performed at 1, 4, 8, and 12 weeks after treatment. RESULTS: Forty-two patients (21 patients in each group) completed the study. The intervention group had a notably shorter time to onset of significant pain relief (6.1 ± 3.4 vs 28.1 ± 9.2 days; P < 0.001) and noticeable reduction of VAS score at week 1 (40% vs 4.7%) than the control group (P < 0.001). All measured variables in the intervention group and most variables in the control group showed significant improvement from the baseline (P < 0.05). A comparison of the 2 groups indicated significantly greater improvement in the intervention group at all times in VAS and shoulder pain and disability index scores (all P < 0.05), and for most gain of PROM (P < 0.05). There were no serious adverse effects or complications in either group. CONCLUSIONS: This study indicates that the application of PRF lesioning of the SSN using a UG technique combined with physical therapy provided better and faster relief from pain, reduced disability, and improved PROM when compared with physical therapy alone in patients with AC, an effect that persisted for at least 12 weeks.

Heart status following high G exposure in rats and the effect of brief preconditioning.

INTRODUCTION: Acceleration on the +Gz axis increases pressure in the cardiac chambers. Our research was designed to study whether: 1) such acceleration would impair cardiac function; and 2) a "preconditioning" exposure to +Gz would protect the heart from any such effects. METHODS: There were 45 male Sprague-Dawley rats that were randomly divided into 3 groups of 15: 1) control without acceleration (CTRL); 2) exposure to 5 min of +15 Gz (EXP); and 3) pretreatment whereby the 5-min exposure was preceded by two exposures of 30 s at +15 Gz (PRE). Within each group of 15, subsets of 7 animals were used to study: 1) echocardiographic heart function or 2) myocardial injury [lactic dehydrogenase (LDH) and malondialdehyde (MDA)], and 1 animal was used to examine the histology of cardiac tissue. RESULTS: Acceleration (EXP) was found to have a significant effect on cardiac function; specifically the early diastolic myocardial velocity (Em) and systolic myocardial velocity (Sm) in both ventricles decreased in EXP compared to CTRL, while PRE significantly reduced this elect. The systolic mitral annular velocity in the left ventricular lateral wall was significantly less affected in PRE than in EXP (1.99 +/- 0.65 vs. 1.2 +/- 0.39 cm x s(-1), P = 0.017). Enzyme levels showed only minor changes. In histology, no neutrophil infiltration was found in three groups. CONCLUSIONS: These results suggest that short bouts of acceleration might offer cardiac protection. Confirmation using larger animal models may allow application of the concept to pilots preparing to undertake sustained high G maneuvers and may explain some aspects of the "G layoff" effect.

Impact of hypoxic and mesopic environments on visual acuity, contrast sensitivity and accommodation in subjects with LASIK surgery and aircrew candidate.

BACKGROUND: The safety of Laser-assisted in situ keratomileusis (LASIK) in aircrew was unclear, in addition, LASIK was not yet approved for aircrew of Taiwan Air Force. This study was aimed to evaluate visual performance in LASIK eyes in hypoxic and twilight environment. METHODS: 48 myopic eyes of 24 subjects enrolled in this study were divided into LASIK group and control group. Subjects were exposed in hypoxic (15% O2) and mesopic (3 cd/m2) environment. Visual performance was evaluated using the Early Treatment of Diabetic Retinopathy Study (ETDRS) visual chart, and Functional Acuity Contrast Test (FACT) before and after the expirement. Physiological parameters of all subjects were measured and recorded throughout the experiment. RESULTS: There was no significant difference of the two groups regarding their age, height, weight, and BMI. There is significant difference of preoperative spherical refractive error between the two groups. The results of physiological parameters were similar between two groups. Under normoxic conditions, there were no significant difference regarding distant vision in photopic and mesopic environments, so as for near vision. As a whole, the contrast sensitivity of the LASIK group were lowered than that of the control group about 35%, under whether normoxic or hypoxic conditions; photopic or mesopic circumstances. Under normoxic conditions, the measured accommodation of the LASIK group were 21% lowered than that of the control group and 31% lowered under hypoxic circumstances. CONCLUSION: There was no significant difference of visual acuity between the two groups regarding hypoxic and mesopic environment, but reduced contrast sensitivity was significant in LASIK group as compared to those of the control group. Accommodation was significantly lowered in LASIK group, compared with control group, in hypoxic environment. Whether postoperative visual performance after LASIK in aircrew during flying duty is safe might need further investigation.

Simulated Microgravity Disrupts Cytoskeleton Organization and Increases Apoptosis of Rat Neural Crest Stem Cells Via Upregulating CXCR4 Expression and RhoA-ROCK1-p38 MAPK-p53 Signaling.

Neural crest stem cells (NCSCs) are a population of multipotent stem cells that are distributed broadly in many tissues and organs and are capable of differentiating into a variety of cell types that are dispersed throughout three germ layers. We are interested in studying the effects of simulated microgravity on the survival and self-renewal of NCSCs. NCSCs extracted from the hair follicle bulge region of the rat whisker pad were cultured in vitro, respectively, in a 2D adherent environment and a 3D suspension environment using the rotatory cell culture system (RCCS) to simulate microgravity. We found that rat NCSCs (rNCSCs) cultured in the RCCS for 24 h showed disrupted organization of filamentous actin, increased globular actin level, formation of plasma membrane blebbing and neurite-like artifact, as well as decreased levels of cortactin and vimentin. Interestingly, ∼70% of RCCS-cultured rNCSCs co-expressed cleaved (active) caspase-3 and neuronal markers microtubule-associated protein 2 (MAP2) and Tuj1 instead of NCSC markers, suggesting stress-induced formation of neurite-like artifact in rNCSCs. In addition, rNCSCs showed increased C-X-C chemokine receptor 4 (CXCR4) expression, RhoA GTPase activation, Rho-associated kinase 1 (ROCK1) and p38 mitogen-activated protein kinase (MAPK) phosphorylation, and p53 expression in the nucleus. Incubation of rNCSCs with the Gα protein inhibitor pertussis toxin or CXCR4 siRNA during RCCS-culturing prevented cytoskeleton disorganization and plasma membrane blebbing, and it suppressed apoptosis of rNCSCs. Taken together, we demonstrate for the first time that simulated microgravity disrupts cytoskeleton organization and increases apoptosis of rNCSCs via upregulating CXCR4 expression and the RhoA-ROCK1-p38 MAPK-p53 signaling pathway.

Ultrasound-Guided Pulsed Radiofrequency for Carpal Tunnel Syndrome: A Single-Blinded Randomized Controlled Study.

OBJECTIVE: We assessed the therapeutic efficiency of ultrasound-guided pulsed radiofrequency (PRF) treatment of the median nerve in patients with carpal tunnel syndrome (CTS). METHODS: We conducted a prospective, randomized, controlled, single-blinded study. Forty-four patients with CTS were randomized into intervention or control groups. Patients in the intervention group were treated with PRF and night splint, and the control group was prescribed night splint alone. Primary outcome was the onset time of significant pain relief assessed using the visual analog scale (VAS), and secondary outcomes included evaluation of the Boston Carpal Tunnel Syndrome Questionnaire (BCTQ) results, cross-sectional area (CSA) of the median nerve, sensory nerve conduction velocity (SNCV) of the median nerve, and finger pinch strength. All outcome measurements were performed at 1, 4, 8, and 12 weeks after treatment. RESULTS: Thirty-six patients completed the study. The onset time of pain relief in the intervention group was significantly shorter (median onset time of 2 days vs. 14 days; hazard ratio = 7.37; 95% CI, 3.04-17.87) compared to the control group (p < 0.001). Significant improvement in VAS and BCTQ scores (p < 0.05) was detected in the intervention group at all follow-up periods compared to the controls (except for the severity subscale of BCTQ at week 1). Ultrasound-guided PRF treatment resulted in a lower VAS score and stronger finger pinch compared to the control group over the entire study. CONCLUSIONS: Our study shows that ultrasound-guided PRF serves as a better approach for pain relief in patients with CTS. TRIAL REGISTRATION: ClinicalTrials.gov NCT02217293.

Rhodiola crenulata Extract Alleviates Hypoxic Pulmonary Edema in Rats.

Sudden exposure of nonacclimatized individuals to high altitude can easily lead to high altitude illnesses. High altitude pulmonary edema (HAPE) is the most lethal form of high altitude illness. The present study was designed to investigate the ability of Rhodiola crenulata extract (RCE), an herbal medicine traditionally used as an antiacute mountain sickness remedy, to attenuate hypoxia-induced pulmonary injury. Exposure of animals to hypobaric hypoxia led to a significant increase in pathological indicators for pulmonary edema, including the lung water content, disruption of the alveolar-capillary barrier, and protein-rich fluid in the lungs. In addition, hypobaric hypoxia also increased oxidative stress markers, including (ROS) production, (MDA) level, and (MPO) activity. Furthermore, overexpression of plasma (ET-1), (VEGF) in (BALF), and (HIF-1 α ) in lung tissue was also found. However, pretreatment with RCE relieved the HAPE findings by curtailing all of the hypoxia-induced lung injury parameters. These findings suggest that RCE confers effective protection for maintaining the integrity of the alveolar-capillary barrier by alleviating the elevated ET-1 and VEGF levels; it does so by reducing hypoxia-induced oxidative stress. Our results offer substantial evidence to support arguments in favor of traditional applications of Rhodiola crenulata for antihigh altitude illness.

Rhodiola crenulata and Its Bioactive Components, Salidroside and Tyrosol, Reverse the Hypoxia-Induced Reduction of Plasma-Membrane-Associated Na,K-ATPase Expression via Inhibition of ROS-AMPK-PKC ξ Pathway.

Exposure to hypoxia leads to impaired pulmonary sodium transport, which is associated with Na,K-ATPase dysfunction in the alveolar epithelium. The present study is designed to examine the effect and mechanism of Rhodiola crenulata extract (RCE) and its bioactive components on hypoxia-mediated Na,K-ATPase endocytosis. A549 cells were exposed to hypoxia in the presence or absence of RCE, salidroside, or tyrosol. The generation of intracellular ROS was measured by using the fluorescent probe DCFH-DA, and the endocytosis was determined by measuring the expression level of Na,K-ATPase in the PM fraction. Rats exposed to a hypobaric hypoxia chamber were used to investigate the efficacy and underlying mechanism of RCE in vivo. Our results showed that RCE and its bioactive compounds significantly prevented the hypoxia-mediated endocytosis of Na,K-ATPase via the inhibition of the ROS-AMPK-PKC ζ pathway in A549 cells. Furthermore, RCE also showed a comparable preventive effect on the reduction of Na,K-ATPase endocytosis and inhibition of AMPK-PKC ξ pathway in the rodent model. Our study is the first to offer substantial evidence to support the efficacy of Rhodiola products against hypoxia-associated Na,K-ATPase endocytosis and clarify the ethnopharmacological relevance of Rhodiola crenulata as a popular folk medicine for high-altitude illness.

Brown-Sèquard syndrome caused by type III odontoid fracture: a case report and review of the literature.

STUDY DESIGN: Case report. OBJECTIVE: To present the second case of Brown-Sèquard syndrome (BSS) produced by type III odontoid fracture managed by conservative treatment. SUMMARY OF BACKGROUND DATA: The occurrence of BSS due to odontoid fracture is scarce. So far 6 cases have been reported, and only 1 is produced by type III odontoid fracture. The possible pathophysiology, clinical course and treatment outcome have been rarely discussed. METHODS: A 39-year-old man presented with weakness of his left arm and leg, mild neck pain, and impaired proprioceptive and light touch sensations below the left C2 dermatome. There were decreased pain and temperature sensations below the right C4 dermatome too. Computerized tomography showed odontoid type III fracture with posterior displacement at that level. Magnetic resonance imaging presented focal hyperintensity around the C2 vertebral level. High dose of prednisolone, close reduction with Gardner-Wells tong skull traction, following external stabilization by Halo-Vest and rehabilitation therapy were applied. RESULTS: Complete resolution of neck pain and significant improvement of motor and sensory functions, i.e., light touch and proprioception, were shown 2 months after spinal injury. Impaired temperature discrimination persisted, however. CONCLUSION: BSS is rarely caused by type III odontoid fracture and this is the second report. Conservative intervention is advantageous for both type III odontoid fracture and BSS which is consistent with previous results.

Concurrent measurement of isokinetic muscle strength of the trunk, knees, and ankles in patients with lumbar disc herniation with sciatica.

STUDY DESIGN: A cross-sectional study comparing normal subjects and patients with lumbar disc herniation (LDH) with sciatica. OBJECTIVE: To simultaneously measure the isokinetic muscle strength of the trunk, knees, and ankles in both groups. SUMMARY OF BACKGROUND DATA: Coordination between the trunk and lower extremity muscles is important for normal physical activity. Reduced trunk and knee muscle strength have been reported in patients with lower level LDH; however, ankle performance in these patients is still unknown. METHODS: We recruited 43 normal subjects as controls and 33 patients with lower level LDH with sciatica. The isokinetic strength of the trunk, knees, and ankles was measured at 2 velocities in random order: 60°/s and 120°/s, and 60°/s and 180°/s for trunk and ankle strength and for knee strength, respectively. RESULTS: The isokinetic trunk strength was significantly lower in the LDH group irrespective of test modes or velocity. Despite unilateral sciatica or test modes and velocity, the unilateral knee strength was significantly lower in the LDH group than that in the control group. Knee extension torque was also found to be significantly lower in the limbs with sciatica than in those without sciatica at the testing velocity of 180°/s (80.25 ± 24.88 vs. 95.42 ± 26.29 Nm, P < 0.05). Irrespective of unilateral sciatica or test velocity, ankle plantar flexion torque revealed to be significantly lower in the LDH group than the control group; however, dorsiflexion torque was not different. Significant correlations were demonstrated among the total muscle strength of the trunk, knees, and ankles in both groups. CONCLUSION: Besides the lower trunk strength, concurrent lower unilateral knee and ankle plantar flexion but not dorsiflexion strength was demonstrated in the LDH subjects with unilateral sciatica, regardless of its location. As compared to the limbs without sciatica, an additional 14% reduction of knee extension torque at 180°/s was found in the limbs with sciatica in the LDH patients.

Isokinetic muscle strength of the trunk and bilateral knees in young subjects with lumbar disc herniation.

STUDY DESIGN: Cross-sectional study comparing normal subjects and patients with lumbar disc herniation. OBJECTIVE: To evaluate trunk and knee muscle strength in patients with L4-L5 and/or L5-S1 disc herniation. SUMMARY OF BACKGROUND DATA: Numerous studies have shown that patients with low back pain have weaker trunk muscles. The strength of trunk and knee muscles has not been investigated simultaneously in patients with lumbar disc herniation. METHODS: Forty-one controls and 2 patients were included. Isokinetic strength of the trunk and bilateral knees was tested on a calibrated isokinetic testing machine (Biodex System 3 Pro) regardless of the laterality of the radiculopathy. The testing was carrying out at two different velocities: 60 degrees and 120 degrees per second. RESULTS: Total trunk strength and knee strength were significantly lower in these patients (4.34 +/- 1.06 and 4.06 +/- 1.16 vs. 6.21 +/- 1.05 and 5.83 +/- 1.09 Nm/kg at 60 degrees and 120 degrees per second, respectively, P < 0.001). In patients with unilateral sciatica, there was no significant difference (P > 0.05) in unilateral knee strength between sciatica-involved and -uninvolved limbs (1.89 +/- 0.5, 1.08 +/- 0.45, 1.48 +/- 0.58, 0.93 +/- 0.41 vs. 1.68 +/- 0.45, 0.91 +/- 0.38, 1.41 +/- 0.48, 0.79 +/- 0.39 Nm/kg in sciatica-uninvolved vs. sciatica-involved limbs during extension and flexion at 60 degrees and 120 degrees per second, respectively). Total trunk strength was significantly correlated with total knee strength in both groups. CONCLUSIONS: In the patients with lumbar disc herniation, muscle strength of the trunk and knees was decreased to a similar extent. Weaker knee strength was found on either side of the lower extremity in the patients with unilateral sciatica, regardless of its location.