Hyperbaric oxygen therapy suppresses hypoxia and reoxygenation injury to retinal pigment epithelial cells through activating peroxisome proliferator activator receptor-alpha signalling.

Retinal ischemia followed by reperfusion (IR) is a common cause of many ocular disorders, such as age-related macular degeneration (AMD), which leads to blindness in the elderly population, and proper therapies remain unavailable. Retinal pigment epithelial (RPE) cell death is a hallmark of AMD. Hyperbaric oxygen (HBO) therapy can improve IR tissue survival by inducing ischemic preconditioning responses. We conducted an in vitro study to examine the effects of HBO preconditioning on oxygen-glucose deprivation (OGD)-induced IR-injured RPE cells. RPE cells were treated with HBO (100% O2 at 3 atmospheres absolute for 90 min) once a day for three consecutive days before retinal IR onset. Compared with normal cells, the IR-injured RPE cells had lower cell viability, lower peroxisome proliferator activator receptor-alpha (PPAR-α) expression, more severe oxidation status, higher blood-retinal barrier disruption and more elevated apoptosis and autophagy rates. HBO preconditioning increased PPAR-α expression, improved cell viability, decreased oxidative stress, blood-retinal barrier disruption and cellular apoptosis and autophagy. A specific PPAR-α antagonist, GW6471, antagonized all the protective effects of HBO preconditioning in IR-injured RPE cells. Combining these observations, HBO therapy can reverse OGD-induced RPE cell injury by activating PPAR-α signalling.

Exercise Rehabilitation and/or Astragaloside Attenuate Amyloid-beta Pathology by Reversing BDNF/TrkB Signaling Deficits and Mitochondrial Dysfunction.

We aim to investigate the mechanisms underlying the beneficial effects of exercise rehabilitation (ER) and/or astragaloside (AST) in counteracting amyloid-beta (Aß) pathology. Aß oligomers were microinjected into the bilateral ventricles to induce Aß neuropathology in rats. Neurobehavioral functions were evaluated. Cortical and hippocampal expressions of both BDNF/TrkB and cathepsin D were determined by the western blotting method. The rat primary cultured cortical neurons were incubated with BDNF and/or AST and ANA12 followed by exposure to aggregated Aß for 24 h. In vivo results showed that ER and/or AST reversed neurobehavioral disorders, downregulation of cortical and hippocampal expression of both BDNF/TrkB and cathepsin D, neural pathology, Aß accumulation, and altered microglial polarization caused by Aß. In vitro studies also confirmed that topical application of BDNF and/or AST reversed the Aß-induced cytotoxicity, apoptosis, mitochondrial distress, and synaptotoxicity and decreased expression of p-TrkB, p-Akt, p-GSK3ß, and ß-catenin in rat cortical neurons. The beneficial effects of combined ER (or BDNF) and AST therapy in vivo and in vitro were superior to ER (or BDNF) or AST alone. Furthermore, we observed that any gains from ER (or BDNF) and/or AST could be significantly eliminated by ANA-12, a potent BDNF/TrkB antagonist. These results indicate that whereas ER (or BDNF) and/or AST attenuate Aß pathology by reversing BDNF/TrkB signaling deficits and mitochondrial dysfunction, combining these two potentiates each other's therapeutic effects. In particular, AST can be an alternative therapy to replace ER.

Mesenchymal stem cell-conditioned medium attenuates the retinal pathology in amyloid-ß-induced rat model of Alzheimer's disease: Underlying mechanisms.

Amyloid-beta (Aß) oligomer is known to contribute to the pathophysiology of age-related macular degeneration. Herein, we aimed to elucidate the in vivo and in vitro effects of Aß1-42 application on retinal morphology in rats. Our in vivo studies revealed that intracerebroventricular administration of Aß1-42 oligomer caused dysmorphological changes in both retinal ganglion cells and retinal pigment epithelium. In addition, in vitro studies revealed that ARPE-19 cells following Aß1-42 oligomer application had decreased viability along with apoptosis and decreased expression of the tight junction proteins, increased expression of both phosphor-AKT and phosphor-GSK3ß and decreased expression of both SIRT1 and ß-catenin. Application of conditioned medium (CM) obtained from mesenchymal stem cells (MSC) protected against Aß1-42 oligomer-induced retinal pathology in both rats and ARPE-19 cells. In order to explore the potential role of peptides secreted from the MSCs, we applied mass spectrometry to compare the peptidomics profiles of the MSC-CM. Gene ontology enrichment analysis and String analysis were performed to explore the differentially expressed peptides by predicting the functions of their precursor proteins. Bioinformatics analysis showed that 3-8 out of 155-163 proteins in the MSC-CM maybe associated with SIRT1/pAKT/pGSK3ß/ß-catenin, tight junction proteins, and apoptosis pathway. In particular, the secretomes information on the MSC-CM may be helpful for the prevention and treatment of retinal pathology in age-related macular degeneration.

Calycosin Preserves BDNF/TrkB Signaling and Reduces Post-Stroke Neurological Injury after Cerebral Ischemia by Reducing Accumulation of Hypertrophic and TNF-α-Containing Microglia in Rats.

Both brain-derived neurotrophic factor (BDNF) and microglia activation are involved in the pathogenesis of ischemic stroke. Herein, we attempt to ascertain whether Calycosin, an isoflavonoid, protects against ischemic stroke by modulating the endogenous production of BDNF and/or the microglia activation. This study was a prospective, randomized, blinded and placebo-controlled preclinical experiment. Sprague-Dawley adult rats, subjected to transient focal cerebral ischemia by middle cerebral artery occlusion (MCAO), were treated randomly with 0 (corn oil and/or saline as placebo), 30 mg/kg of Calycosin and/or 1 mg/kg of a tropomyosin-related kinase B (TrkB) receptor antagonist (ANA12) at 1 h after reperfusion and once daily for a total of 7 consecutive days. BDNF and its functional receptor, full-length TrkB (TrkB-FL) levels, the percentage of hypertrophic microglia, tumor necrosis factor-α (TNF-α)-containing microglia, and degenerative and apoptotic neurons in ischemic brain regions were determined 7 days after cerebral ischemia. A battery of functional sensorimotor test was performed over 7 days. Post-stroke Calycosin therapy increased the cerebral expression of BDNF/TrkB, ameliorated the neurological injury and switched the microglia from the activated amoeboid state to the resting ramified state in ischemic stroke rats. However, the beneficial effects of BDNF/ TrkB-mediated Calycosin could be reversed by ANA12. Our data indicate that BDNF/TrkB-mediated Calycosin ameliorates rat ischemic stroke injury by switching the microglia from the activated amoeboid state to the resting ramified state. Graphical abstract.

A high-loading drug delivery system based on magnetic nanomaterials modified by hyperbranched phenylboronic acid for tumor-targeting treatment with pH response.

To overcome the limited drug loading capacity of magnetic nanopharmaceuticals arising from the relatively large mass of the metal core, a high-loading drug delivery system based on amino-functionalized Fe3O4 magnetic nanospheres modified by hyperbranched phenylboronic acid (HPBA-Fe3O4) were prepared for the first time. The obtained nanomaterials were characterized by transmission electron microscopy, Fourier transform infrared, zeta potential, elemental analysis, vibrating sample magnetometry and X-ray diffraction analysis, and the results showed that hyperbranched phenylboronic acid (HPBA) were successfully grafted onto the surface of the magnetic nanospheres. The polymerization conditions, adsorption and desorption performance, and tumor-targeting ability of HPBA-Fe3O4 was investigated in detail through chemical and biological experiments. The drug loading amount and capacity of HPBA-Fe3O4 are 271.3 mg/g and 27.13%, respectively, which are 2.26 and 3.27 times greater than those of PBA-Fe3O4 and PEI-Fe3O4, and the thermodynamic fitting results further demonstrate the high drug loading ability of HPBA-Fe3O4. In vitro studies performed in U-87 MG malignant glioma cells and astrocytes via light and fluorescence microscopy analyses, cell counting kit-8 assays, and HPLC tests confirm the pH-sensitive release and tumor-targeted drug delivery capabilities of HPBA-Fe3O4. The facile fabrication of hyperbranched magnetic nanomaterials could be an alternative solution for designing high-loading, tumor cell-targeting and pH-responsive DDSs with high-mass cores.

Surgical management of retroperitoneal schwannoma complicated with severe hydronephrosis: A case report.

RATIONALE: Schwannomas are usually benign tumors arising from well-differentiated schwann cells, which rarely occur in the retroperitoneal space. The lack of specific signs and radiologic imaging characteristics makes preoperative diagnosis rather difficult. Most retroperitoneal schwannomas are benign and the primary treatment choice for retroperitoneal schwannomas is surgical excision, however, the involvement of the urinary system is scarcely reported. PATIENT CONCERNS: A 34-year-old woman presented with progressive left abdominal pain and rebound abdominal mass at the left lower quadrant for 1 month. Radiological imaging suggested capsulated solid mass with cystic and necrotic areas in the retroperitoneum accompanied by severe left kidney hydronephrosis and preoperative biopsy result was inconclusive. DIAGNOSES: We believe this is a rare case of retroperitoneal schwannoma complicated with severe hydronephrosis. INTERVENTIONS: After preparation, the patient underwent laparoscopy exploration and converted to open surgical exploration. The patient accepted complete surgical excision of the retroperitoneal tumor and left kidney. Postoperative pathology diagnosis of the mass was proven to be benign retroperitoneal schwannoma. OUTCOMES: Postoperative course of the patient was uneventful and the left abdominal pain was greatly improved. After 12-month follow up, no evidence of recurrence or any other complication including renal failure was observed. LESSONS: Preoperative imaging and preoperative ultrasound-guided biopsy are helpful to make accurate diagnosis. The final diagnosis is based on postoperative histological and immunohistochemical findings. The primary treatment option is complete surgical resection of the retroperitoneal schwannoma and the involved upper urinary system when severe hydronephrosis occured. Local recurrence and overall survival are closely correlated with negative resection margins and pathology types.

Exercise Rehabilitation Attenuates Cognitive Deficits in Rats with Traumatic Brain Injury by Stimulating the Cerebral HSP20/BDNF/TrkB Signalling Axis.

Physical exercise (PE) is an effective method for improving cognitive function among patients with traumatic brain injury (TBI). We previously demonstrated that PE with an infrared-sensing running wheel (ISRW) system provides strong neuroprotection in an experimental animal model of stroke. In this study, we used fluid percussion injury in rats to simulate mild TBI. For rats, we used both passive avoidance learning and the Y-maze tests to evaluate cognitive function. We investigated whether PE rehabilitation attenuated cognitive deficits in rats with TBI and determined the contribution of hippocampal and cortical expression of heat shock protein 20 (HSP20) to PE-mediated cognitive recovery. In addition to increasing hippocampal and cortical expression of HSP20, brain-derived neurotrophic factor (BDNF), and the tropomyosin receptor kinase B (TrkB) ratio, PE rehabilitation significantly attenuated brain contusion and improved cognitive deficits in the rat model. Furthermore, reducing hippocampal and cortical expression of HSP20 with an intracerebral injection of pSUPER hsp20 small interfering RNA significantly diminished the PE-induced overexpression of hippocampal and cortical BDNF and the TrkB ratio and also reversed the beneficial effect of PE in reducing neurotrauma and the cognitive deficits. A positive Pearson correlation was found between HSP20 and BDNF, as well as between HSP20 and TrkB, in the hippocampal and cortical tissues. We thus conclude that post-ischaemic ISRW exercise rehabilitation attenuates cognitive deficits, as well as brain contusions, in TBI rats by stimulating the cerebral HSP20/BDNF/TrkB signalling axis.

Beneficial Effect of Astragaloside on Alzheimer's Disease Condition Using Cultured Primary Cortical Cells Under ß-amyloid Exposure.

ß-amyloid (Aß)-mediated neuronal apoptosis contributes to the pathogenesis of Alzheimer's disease (AD). This study aimed to investigate whether astragalosides (AST) could inhibit Aß-induced apoptosis in vivo and in vitro and to explore the underlying mechanisms. Amyloid ß-protein fragment 25-35 (Aß25-35) was administered to cerebral lateral ventricle of rats to make the AD models in vivo. AST was able to attenuate both cortical cell degeneration and memory deficits in the AD rats. AST also inhibited Aß25-35-induced cytotoxicity (e.g., decreased cell viability); apoptosis (e.g., increased caspase-3 expression, increased DNA fragmentation, and Tau hyperphosphorylation); synaptotoxicity (e.g., increased loss of both a dendritic marker, microtubule-associated protein 2 (MAP-2) and synaptic proteins, synaptophysins); and mitochondrial dysfunction (e.g., increased mitochondrial membrane potential) in cultured primary rat cortical cells. The beneficial effect of AST in reducing Aß-induced cytotoxicity, apoptosis, and mitochondrial dysfunction in cortical cells were blocked by inhibition of phosphoinositide 3-kinase (PI3K)-dependent protein kinase B (PKB, as known as AKT) activation with LY294002. In addition, inhibition of extracellular protein kinase (ERK) with U0126 shared with the AST the same beneficial effects in reducing Aß-induced apoptosis. Our data suggest that the cortical PI3K/AKT and MAPK (or ERK) pathways as appealing therapeutic targets in treating AD, and AST may have a positive impact on AD treatment via modulation of both PI3K/AKT and ERK pathways.

Beneficial effect of astragalosides on stroke condition using PC12 cells under oxygen glucose deprivation and reperfusion.

Astragalosides (AST) are reported to be neuroprotective in focal cerebral ischemic models in vivo. In this study, the direct effect of AST against oxygen and glucose deprivation (OGD) including neuronal injury and the underlying mechanisms in vitro were investigated. 5 h OGD followed by 24 h of reperfusion [adding back oxygen and glucose (OGD-R)] was used to induce in vitro ischemia reperfusion injury in differentiated rat pheochromocytoma PC12 cells. AST (1, 100, and 200 µg/mL) were added to the culture after 5 h of the OGD ischemic insult and was present during the reoxygenation phases. A key finding was that OGD-R decreased cell viability, increased lactate dehydrogenase, increased reactive oxygen species, apoptosis, autophagy, functional impairment of mitochondria, and endoplasmic reticulum stress in PC12 cells, all of which AST treatment significantly reduced. In addition, AST attenuated OGD-R-induced cell loss through P38 MAPK activation a neuroprotective effect blunted by SB203580, a specific inhibitor of P38 MAPK. Our data suggest that both apoptosis and autophagy are important characteristics of OGD-R-induced PC12 death and that treating PC12 cells with AST blocked OGD-R-induced apoptosis and autophagy by suppressing intracellular oxidative stress, functional impairment of mitochondria, and endoplasmic reticulum stress. Our data provide identification of AST that can concomitantly inhibit multiple cells death pathways following OGD injuries in neural cells.

Diurnal temperature range and emergency room admissions for chronic obstructive pulmonary disease in Taiwan.

The objective of this study was to assess the relationship between diurnal temperature range (DTR) and emergency room (ER) admissions for chronic obstructive pulmonary disease (COPD) in an ER in Taichung City, Taiwan. The design was a longitudinal study in which DTR was related to COPD admissions to the ER of the city's largest hospital. Daily ER admissions for COPD and ambient temperature were collected from 1 January 2001 to 31 December 2002. There was a significant negative association between the average daily temperature and ER admissions for COPD (r=-0.95). However, a significant positive association between DTR and COPD admissions was found (r=0.90). Using the Poisson regression model after adjusting for the effects of air pollutants and the day of the week, COPD admissions to the ER increased by 14% when DTR was over 9.6 degrees C. COPD patients must be made aware of the increased risk posed by large DTR. Hospitals and ERs should take into account the increased demand of specific facilities during periods of large temperature variations.

Both mild hypothermia and dopamine D(2) agonist are neuroprotective against hyperthermia-induced injury in PC12 cells.

We exposed rat pheochromocytoma PC12 cells to hyperthermia or high dosage of dopamine and examined the direct effects of mild hypothermia or dopamine D(2) receptor agonist. At a hyperthermia of 42-43 degrees C for 120 min there was approximately 50% loss of cell viability accompanied by dopamine overproduction. The model of cell death due to hyperthermia in PC12 cells belonged to the necrotic and late apoptotic population. At each temperature examined below 37 degrees C, significant decrease in cytotoxicity, the percentage of necrotic and late apoptotic cells, and dopamine overproduction were observed. Cytotoxicity could also be induced by high dosages of dopamine. Both hyperthermia and dopamine induced cytotoxicity in PC12 cells could also be reduced by dopamine D(2) agonists. These results indicate the dopamine is important in hyperthermic situations. The results also indicate that mild hypothermia and dopamine D(2) receptor agonists are neuroprotective against hyperthermia-induced brain injury.

Ambient temperature and emergency room admissions for acute coronary syndrome in Taiwan.

Acute coronary syndrome (ACS) is an important public health problem around the world. Since there is a considerable seasonal fluctuation in the incidence of ACS, climatic temperature may have an impact on the onset of this disease. The objective of this study was to assess the relationship between the average daily temperature, diurnal temperature range and emergency room (ER) admissions for ACS in an ER in Taichung City, Taiwan. A longitudinal study was conducted which assessed the correlation of the average daily temperature and the diurnal temperature range to ACS admissions to the ER of the city's largest hospital. Daily ER admissions for ACS and ambient temperature were collected from 1 January 2000 to 31 March 2003. The Poisson regression model was used in the analysis after adjusting for the effects of holiday, season, and air pollutant concentrations. The results showed that there was a negative significant association between the average daily temperature and ER admissions for ACS. ACS admissions to the ER increased 30% to 70% when the average daily temperature was lower than 26.2 degrees C. A positive association between the diurnal temperature range and ACS admissions was also noted. ACS admissions increased 15% when the diurnal temperature range was over 8.3 degrees C. The data indicate that patients suffering from cardiovascular disease must be made aware of the increased risk posed by lower temperatures and larger changes in temperature. Hospitals and ERs should take into account the increased demand of specific facilities during colder weather and wider temperature variations.

Carotid artery injury with cerebral infarction following head and neck blunt trauma: report of a case.

Blunt injury to the carotid artery is rare but may produce a devastating outcome with longterm morbidity. Initial recognition by clinicians is often difficult because of the diverse clinical manifestations, the delay in presentation of symptoms, and the associated multi-organ system injuries that accompany carotid injury. Early diagnosis and successful management of traumatic carotid artery injury require a high index of clinical suspicion. We report herein a 20-year-old male victim of internal carotid artery injury induced by a motorcycle accident, who initially presented with a clear consciousness and had normal computed tomogram (CT) of brain. Two days after injury, the patient suffered from left hemiplegia and coma. The follow-up brain CT showed acute infarction of right cerebrum and severe cerebral edema. Emergency craniotomy for brain decompression and anticoagulation therapy was carried out. After a three-month treatment, he was discharged and underwent regular follow-up in the outpatient department. Six months later, the patient had intact awareness but remained in a left-sided hemiparetic state.

Acute thoracic aortic dissection presenting as sore throat: report of a case.

Acute dissection of the aorta can be one of the most dramatic of cardiovascular emergencies. Its symptoms can occur abruptly and progress rapidly. Prompt recognition and appropriate intervention is crucial. However, not all aortic dissections present with classic symptoms of abrupt chest, back, or abdominal pain, and the diagnosis may be missed. Aortic dissection presenting as a sore throat is quite unusual. A 53-year-old man presented with sore throat as the early symptom of an acute thoracic aortic dissection. Unfortunately, the diagnosis was delayed, and the patient died. Given the high morbidity and mortality after delayed recognition or misdiagnosis, aortic dissection should be considered in the differential diagnosis of a patient presenting with sore throat and normal findings of neck and throat, even when there is no classic symptoms.

Aortic dissection presenting as acute lower extremity ischemia: report of a case.

Although not common, acute leg ischemia is an important element in the clinical presentation of a patient with aortic dissection. This report describes a case of aortic dissection in which the main feature at presentation was acute right leg ischemia. The angiography showed right common iliac artery and external iliac artery occlusion. Diagnosis was made by clinical evaluation and angiography. Embolectomy was then attempted immediately but failed. Aortic dissection was highly suspected and confirmed by emergency computed tomography. Fortunately, the patient had good recovery. Aortic dissection is potentially lethal if misdiagnosed or if recognition is delayed. As such, aortic dissection should be considered in the differential diagnosis.