Multiple sclerosis (MS) is a chronic inflammatory demyelinating and neurodegenerative disease of the central nervous system. Despite a variety of anti-inflammatory or immunomodulation drugs including interferon-β are effective to reduce relapse risk, most patients have progressive neurological deterioration due to axonal degeneration. Accumulation of activated microglia is a pathological hallmark of active MS lesion. Microglia can act as not only antigen-presenting cells but also effector cells to damage other cells in the central nervous system. Especially, glutamate released by activated microglia induces excito-neurotoxicity and may contribute to neurodegeneration in MS. Gap junction is a major cell-to-cell channel and is composed of paired hemichannels on coupled cells. Recent studies showed that cells release various small molecules (including ions, ATP, and amino acids) from unpaired hemichannel of gap junction that is openly exposed to the extracellular space. We have previously revealed that activated microglia produce glutamate via glutaminase and release it through hemichannels of gap junctions. Thus, in this study, we examined whether the glutaminase inhibitor and the gap junction blocker relieved experimental autoimmune encephalomyelitis (EAE) that is an animal model of MS. Here we show that the gap junction blocker carbenoxolone (CBX) and the glutaminase inhibitor 6-diazo-5-oxo-L-norleucine (DON) decreased glutamate release from activated microglia and rescued neuronal death in a dose-dependent manner in vitro. In EAE mice, treatment with CBX or DON also attenuated EAE clinical symptoms. Thus, blockade of glutamate release from activated microglia with CBX or DON may be an effective therapeutic strategy against neurodegeneration in MS.
The biodiversity of medicinal plants in South Africa makes them rich sources of leading compounds for the development of novel drugs. Peltophorum africanum (Fabaceae) is a deciduous tree widespread in South Africa. The stem bark has been traditionally employed to treat diarrhoea, dysentery, sore throat, wounds, human immunodeficiency virus/ acquired immune deficiency syndrome (HIV/AIDS), venereal diseases and infertility. To evaluate these ethnobotanical clues and isolate lead compounds, butanol and ethyl acetate extracts of the stem bark were screened for their inhibitory activities against HIV-1 using MAGI CCR5+ cells, which are derived from HeLa cervical cancer cells and express HIV receptor CD4, a chemokine receptor CCR5 and HIV-LTR-β- galactosidase. Bioassay-guided fractionation using silica gel chromatography was also conducted. The ethyl acetate and butanol extracts of the stem bark of Peltophorum africanum showed inhibitory activity against HIV-1, CXCR4 (X4) and CCR5 (R5) tropic viruses. The ethyl acetate and butanol extracts yielded previously reported anti-HIV compounds, (+)-catechin, a flavonoid, and bergenin, a C-galloylglycoside, respectively. Furthermore, we identified betulinic acid from the ethyl acetate fraction for the first time. The fractions, which contained betulinic acid, showed the highest selective index. We therefore describe the presence of betulinic acid, a not well-known anti-HIV compound, in an African medicinal herb, which has been used for therapy, and claim that betulinic acid is the predominant anti-HIV-1 constituent of Peltophorum africanum. These data suggest that betulinic acid and its analogues could be used as potential therapeutics for HIV-1 infection.
Lung cancer commonly occurs in individuals who are 60 years of age or older. Lung cancer in patients younger than 40 years of age is rare and is often advanced when discovered. However, the biological features of lung cancer in young adults have not yet been fully elucidated. This study was conducted to determine the role of p53 expression and neoangiogenesis in lung adenocarcinomas of young patients. Lung adenocarcinomas, which were surgically resected from 20 patients younger than 40 years of age between 1977 and 1996, were compared with lung adenocarcinomas selected with random sampling from 45 patients older than 60 years of age. The expression of p53, vascular endothelial growth factor (VEGF), CD34, a marker for vascular endothelial cells, and proliferating cell nuclear antigen (PCNA) were studied immunohistochemically in both young and elderly patient groups. Lung adenocarcinomas with p53-positive staining showed higher expression of VEGF protein than p53-negative tumors in both the young and the elderly groups. However, the intratumoral microvessel count was significantly higher in the p53-positive young group than in the elderly group. The percentage of VEGF-positive cells correlated significantly with intratumoral microvessel counts in the young group. The survival rate tended to be poorer in patients with a high VEGF labeling index and p53-positive staining than in other young patients. Lung adenocarcinoma occurring in young patients tends to have a poorer prognosis, and angiogenesis of lung adenocarcinoma in young patients is more closely correlated with p53 expression than in elderly patients.
Surgical patients often show physiological and metabolic distress, muscle weakness, and long hospital stays. Physical conditioning might help recovery. We attempted to identify the most responsive measure of aerobic fitness from a four-week pre-surgical aerobic exercise program (prehabilitation) in patients undergoing major bowel resection. Twenty-one subjects randomized two to one (exercise: control) scheduled for colorectal surgery. Fourteen subjects [Body Mass Index (BMI) = 27 ± 6 kg/m2; maximal oxygen uptake (VO2max) = 22 ± 10 ml/kg/min] underwent 3.8 ± 1.2 weeks (27 ± 8 sessions) of progressive, structured pre-surgical aerobic exercise training at 40 to 65% of heart rate reserve (%HRR). Peak power output was the only maximal measure that was responsive to training [26 ± 27%, Effects Size (ES) = 0.24; Standardized Response Mean (SRM) = 1.05; p < 0.05]. For the submaximal measures, heart rate and oxygen uptake during submaximal exercise was most responsive to training (decrease by 13% ± 15%, ES = −0.24; SRM = −0.57; and 7% ± 6%, ES = −0.40; SRM −0.97; p < 0.05) at an exercise intensity of 76 ± 47 W. There was no change to maximal or submaximal measures in the control group. The distance walked over six minutes improved in both groups (by ∼30 m), but the effect size and t-statistic were higher in the exercise group. Heart rate and oxygen uptake during submaximal exercise, and peak power output are the most responsive measures to four weeks of prehabilitation in subjects with low initial fitness.
(1-3)-β-D-glucan (BDG) is a cell-wall polysaccharide component found in most fungi. The measurement of BDG is a useful diagnostic marker for invasive fungal infections. However, it is well known that interfering substances can result in false positive reactions. We encountered a patient who underwent lung transplantation and presented with highly elevated BDG values, despite having no evidence of invasive fungal infection. We therefore hypothesized that elevated BDG values were originated from the gauze products used during surgery. While it is known that gauze products contain BDG, there have been no previous reports to quantitatively correlate amount of gauze usage and BDG levels. In this study, we extracted BDG from various gauze products and measured BDG to better understand the degree of which gauze contributes to elevated BDG values. Six types of commonly used surgical gauze products were selected for our study. Each of the surgical gauze was immersed in sterile, purified water for up to 120 minutes. At set intervals, BDG values in the water extracts were measured. Purified water samples without gauze were used as negative controls (< 4 pg/ml). After 120-minute extraction, BDG levels varied greatly depending on gauze products, ranging from 11.7 pg/ml to 6612 pg/ml. The gauze made of lyocell, which is a fiber produced from wood pulp cellulose, yielded the lowest levels of BDG, and probably would not cause false positive for fungal infections. There is a need for the development of a gauze product that does not contribute to elevated BDG values.
Angiotensin II (ANG II), the biologically active peptide of the renin-angiotensin system (RAS), is generated by angiotensin-converting enzyme (ACE) and is a regulator of cardiovascular homeostasis. Recently, there has been increasing evidence that ANG II is involved in the regulation of cell proliferation and migration, as well as angiogenesis via the ANG II-type 1 receptor (AT1R). These findings suggest that the ACE-ANG II-AT1R pathway is related to cancer biology. Previous reports have shown that ACE is preferentially expressed in pancreatic ductal adenocarcinoma (PDAC) tissues. Recently a homologue of ACE, angiotensin-converting enzyme 2 (ACE2), was reported to counterbalance the function of ACE, but the expression and role of ACE2 in PDAC are still unclear. In the present study, we analyzed the expression of ACE2 in invasive human PDAC and surrounding non-malignant tissues by Western blot analysis and immunohistochemistry. The ANG II concentration in homogenates of pancreatic tissues was measured with ELISA, and ACE2 protein was detected by Western blot analysis in BxPC3 and SW1990 human pancreatic ductal cancer cells. We have shown for the first time that the expression of ACE2 is decreased in PDAC tissues, in which ANG II was accumulated. Treatment of BxPC3 and SW1990 cells with ANG II decreased the expression of ACE2. Therefore, ANG II may contribute to the down-regulation of ACE2. Moreover, reduction of ACE2 expression by RNA interference promoted the proliferation of cultured pancreatic cancer cells. These findings suggest that ACE2 may have clinical potential as a novel molecular target for the treatment of PDAC.
Pure bronchioloalveolar carcinomas have no stromal, vascular or pleural invasion, and they are candidates for curative wedge resection, although standard operative procedure for lung cancer is a pulmonary lobectomy. Most lung cancers with ground glass opacity (GGO), namely faint homogeneous shadows with sharp margin, are pure bronchioloalveolar carcinomas. This report presents the results of a pilot study on wedge resection with candidate selection by high-resolution computed tomography and positron emission tomography with 18F-fluorodeoxyglucose (FDG). The criteria for wedge resection were; 1) clinically no nodal or distant metastasis, 2) the location of the tumor was peripheral enough to undergo wedge resection, 3) the diameter of the shadow was 8-20 mm, 4) GGO% (diameter of GGO area/diameter of whole tumor) was 80% or over, 5) FDG uptake of the tumor was less than that of the mediastinum, 6) the intraoperative pathological diagnosis was non-invasive bronchioloalveolar carcinoma, and 7) informed consent was obtained. Nine tumors from 8 patients were selected in the study. The maximum diameter of the tumors was 9-18 mm and GGO% was 82-100%. All of nine tumors were treated with a wedge resection under video-assisted thoracic surgery. The postoperative courses were uneventful and no recurrence has been detected after 19-50-month follow-up. The changes in pulmonary function before and after the surgery were minimal. In conclusion, wedge resections were safely performed without any recurrence, and the postoperative pulmonary function was well preserved, suggesting the advantage of wedge resections for non-invasive bronchioloalveolar carcinomas.
It has been reported that left ventricular (LV) diastolic functional parameters assessed by conventional Doppler echocardiography, which measures blood flow velocities in cardiac cavity, correlate with arterial stiffness assessed by the cardio-ankle vascular index (CAVI) and are markers for increased risk of cardiovascular events. Recently, tissue Doppler echocardiography, which measures velocities of regional cardiac wall, has been widely used for assessment of LV diastolic function because of more accuracy than conventional Doppler echocardiography. However, there are no data regarding the ability of tissue Doppler echocardiography for predicting increased arterial stiffness. We investigated the correlation of LV diastolic functional parameters from tissue Doppler echocardiography to CAVI in order to clarify the ability of tissue Doppler echocardiography for predicting increased arterial stiffness in patients with cardiovascular risk factors. Enrolled in the study were 70 patients (69 ± 8 years) who had no overt heart disease, but had at least one of hypertension, diabetes, and dyslipidemia. The peak early diastolic mitral annular velocity (E') was measured as an index of LV diastolic function using tissue Doppler echocardiography. The E' was correlated with CAVI (r = −0.518, p < 0.001). The optimal cut-off point for the detection of abnormal CAVI (≥ 8.81) was 5.6 cm/s for E' (sensitivity 71%, specificity 71%). The decrease in E' correlated with both LV diastolic dysfunction and increased arterial stiffness. Therefore, the LV diastolic dysfunction assessed by tissue Doppler echocardiography may be useful for predicting increased arterial stiffness and cardiovascular events in the patients with risk factors.
Functional neuroimaging studies have shown that cognitive processes increase regional cerebral blood flow in relation with enhanced neuronal activity. However, cognition induces elevation of blood pressure, heart rate and respiratory rate, each of which also affects cerebral circulation. For proper interpretation of functional neuroimaging data, it is necessary to dissociate the effects of systemic and local metabolic reactions on regional cerebral circulation. To elucidate this interaction, we examined the changes in cerebral blood flow velocity, which were caused by voluntary hyperventilation-induced hypocapnia without cognitive effort and hypocapnia evolving during mental arithmetic task. The cerebral blood flow velocity was recorded in the middle cerebral arteries, using transcranial Doppler sonography. Respiratory rate, end-tidal partial pressure of CO2, heart rate and arterial blood pressure were simultaneously monitored. Data were statistically evaluated. Hypocapnia induced by voluntary hyperventilation without cognition decreased the cerebral blood flow velocity. During mental arithmetic, the cerebral blood flow velocity first increased, but the hypocapnia, which was induced by involuntary hyperventilation related to cognitive effort, reduced it. This implies temporary vasoconstriction of cerebral microvessels, and the increase in cerebral vascular resistance index supports this finding. These results suggest that hypocapnia, which develops during cognition, may decrease blood flow velocity in the middle cerebral arteries, which interferes with the neuronal activity-driven regulation of cerebral circulation. In conclusion, when interpreting the results of functional neuroimaging studies on cognitive mechanisms, the tight coupling of the effects of mental processes and autonomic/metabolic reactions should be considered.
Hypothermic preservation of the organ for transplantation causes vascular damage; therefore, the preservation of vascular function is important for the organs to function correctly after transplantation. The aim of the present study is to evaluate the influence of prolonged cold storage (72 hours) on vascular responses to 5-hydroxytryptamine (5-HT) and potassium chloride (KCl), each of which causes receptor-dependent and receptor-independent contractions, respectively. We also examined the protective roles of superoxide dismutase (SOD), L-arginine, the precursor of nitric oxide, iloprost, a synthetic analogue of prostaglandin I2 with vasodilator functions, or endothelium removal for vascular responses. Endothelium-intact rings were prepared from the rat thoracic aorta, and stored at 4°C for up to 72 hours in Krebs solution alone or Krebs solution that contains SOD, L-arginine or iloprost. The vascular responses were investigated daily. The Analysis of Variance (ANOVA) followed by Dunn test was used for statistical analysis. Being kept in cold in Krebs solution diminished the vascular responses to 5-HT and KCl. The presence of SOD in Krebs solution successfully prevented the decline in these responses, while iloprost or L-arginine partially restored them. In the endothelium-denuded rings, the 5-HT-induced contraction remained protected after 72 hours, whereas the KCl-induced contraction was partially restored. These results indicate that cold preservation declines the 5-HT and KCl-induced vascular responses, which can be partially prevented by iloprost or L-arginine, and can be restored by endothelium removal or SOD. Therefore, superoxide anion and endothelium-derived factors contribute to the decline in the contracting function of the aorta during prolonged cold storage.