Bisphenol A exposure induces neurobehavioral deficits and neurodegeneration through induction of oxidative stress and activated caspase-3 expression in zebrafish brain.

Bisphenol A (BPA) is noted for its adversative effects by inducing oxidative stress, carcinogenicity, neurotoxicity, inflammation, etc. However, the likely act of BPA in inducing neurodegenerative phenotypes remains elusive in the available literature. Hence, the present study was conducted to decipher the neurodegenerative potential of BPA in inducing Parkinson's disease like phenotypes in zebrafish. Zebrafish were subjected to chronic waterborne exposure to BPA for 56 days. Locomotor activities and neurobehavioral response were assessed by the NTDT (novel tank diving test), OFT (open field test), and LDPT (light-dark preference test). The oxidative stress markers and histopathological observation for pyknosis and chromatin condensation were carried out. Immunohistochemistry for activated caspase-3 and targeted proteins expression study was performed. The basic findings reveal that chronic BPA exposure significantly induces locomotor dysfunction through a significant decline in mean velocity and total distance traveled. As a measure of pyknosis and chromatin condensation, pyknotic and Hoechst positive neurons in telencephalon and diencephalon significantly increased by BPA exposure. A higher concentration of BPA adversely affects the neurobehavioral response, antioxidant status, and neuromorphology in zebrafish. Parkinson-relevant targeted protein expression viz. alpha-synuclein and LRRK2, were significantly upregulated, whereas tyrosine hydroxylase, NeuN, and Nurr1 were significantly downregulated in the zebrafish brain. As an indicator of cell death by apoptosis, the expression of activated caspase-3 was significantly increased in the BPA-exposed zebrafish brain. These basic results of the current study indicate that chronic waterborne exposure to BPA induces neuropathological manifestation leading to the development of motor dysfunction and Parkinsonism-like neurodegenerative phenotypes in zebrafish.

Microcirculatory changes in venous leg ulcers using intermittent electrostimulation of common peroneal nerve.

OBJECTIVE: Activation of the venous muscle pumps of the leg by intermittent transdermal neuromuscular stimulation of the common peroneal nerve has been previously shown to augment venous and arterial flow in patients with leg ulcers. This study aims to establish if microcirculation in the wound bed and periwound area are augmented by the activation of a neuromuscular electrostimulation device (NMES) (Geko, Firstkind Ltd., UK). METHOD: In this self-controlled, observational study, laser speckle contrast imaging was used to map and quantify microcirculatory flow in the wound bed and periwound area of patients with venous leg ulcers (VLU). Values of flow and pulsatility in these locations were compared with the NMES device, both active and inactive. RESULTS: A total of 16 patients took part in the study. Microvascular flux increased by 27% (p=0.014) in the wound bed, and by 34% (p=0.004) in the periwound area, when the NMES device was activated. Pulsatility increased by 170% (p<0.001) in the wound bed and 173% (p<0.001) in the periwound area when the device was activated. CONCLUSION: Intermittent electrostimulation of the common peroneal nerve substantially increased both microcirculatory flux and pulsatility in the wound bed and in the periwound area of the VLUs of patients in this study. This provides a plausible mechanistic explanation for its reported efficacy in healing VLUs.

Neuromuscular stimulation of the common peroneal nerve increases arterial and venous velocity in patients with venous leg ulcers.

Activation of the venous muscle pumps by neuromuscular stimulation of the common peroneal nerve has been previously shown to increase venous and arterial flow in the legs of healthy subjects. The aim of this study is to determine whether a similar effect is observed in patients with chronic venous leg ulcers. 1 Hz intermittent electrostimulation of the common peroneal nerve was applied to 14 patients with ulcers between 1 and 10 cm in diameter, eliciting a small, painless, regular, muscular twitch of the leg. Flow was measured using Duplex ultrasound in the popliteal vein and the popliteal artery. Peak arterial velocity increased from 57 to 78 cm/s (P = .001) in sitting position, and from 79 to 98 cm/s in recumbent position (P = .001). Peak venous velocity increased from 10 to 33 cm/s (P = .001) sitting, and from 14 to 47 cm/s (P = .001) recumbent. Significant increases were observed in both venous and arterial blood flow in the lower limb. This suggestsed that activation of the venous muscle pump and improvement of arterial flow assisted oxygen delivery at the wound site. Moreover this may be a worthwhile intervention to assist in the healing of venous leg ulcers, and may provide a mechanistic explanation for the increased healing rates previously reported with neuromuscular stimulation of the common peroneal nerve.

RNA-Binding RING E3-Ligase DZIP3/hRUL138 Stabilizes Cyclin D1 to Drive Cell-Cycle and Cancer Progression.

DZIP3/hRUL138 is a poorly characterized RNA-binding RING E3-ubiquitin ligase with functions in embryonic development. Here we demonstrate that DZIP3 is a crucial driver of cancer cell growth, migration, and invasion. In mice and zebrafish cancer models, DZIP3 promoted tumor growth and metastasis. In line with these results, DZIP3 was frequently overexpressed in several cancer types. Depletion of DZIP3 from cells resulted in reduced expression of Cyclin D1 and a subsequent G1 arrest and defect in cell growth. Mechanistically, DZIP3 utilized its two different domains to interact and stabilize Cyclin D1 both at mRNA and protein levels. Using an RNA-binding lysine-rich region, DZIP3 interacted with the AU-rich region in 3' untranslated region of Cyclin D1 mRNA and stabilized it. Using a RING E3-ligase domain, DZIP3 interacted and increased K63-linked ubiquitination of Cyclin D1 protein to stabilize it. Remarkably, DZIP3 interacted with, ubiquitinated, and stabilized Cyclin D1 predominantly in the G1 phase of the cell cycle, where it is needed for cell-cycle progression. In agreement with this, a strong positive correlation of mRNA expression between DZIP3 and Cyclin D1 in different cancer types was observed. Additionally, DZIP3 regulated several cell cycle proteins by modulating the Cyclin D1-E2F axes. Taken together, this study demonstrates for the first time that DZIP3 uses a unique two-pronged mechanism in its stabilization of Cyclin D1 to drive cell-cycle and cancer progression. SIGNIFICANCE: These findings show that DZIP3 is a novel driver of cell-cycle and cancer progression via its control of Cyclin D1 mRNA and protein stability in a cell-cycle phase-dependent manner. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/81/2/315/F1.large.jpg.

Differential responses of autonomic function in sea level residents, acclimatized lowlanders at >3500 m and Himalayan high altitude natives at >3500 m: A cross-sectional study.

We studied the differential responses of autonomic function in sea level residents (SLR), acclimatized lowlanders (ALH) in high altitude (HA) and HA natives (HAN) at >3500 m. Out of 771 male volunteers included in this cross-sectional study, SLR, ALH and HAN groups were comprised of 351, 307 and 113 volunteers, respectively. Our results showed persistent sympathetic dominance with significantly reduced (p < 0.05) parasympathetic response in ALH as compared to SLR and HAN populations. This may be attributed to significantly increased (p < 0.05) concentration of coronary risk factors and plasma catecholamines in ALH as compared to SLR and HAN. The ALH also showed significantly increased (p < 0.05) level of serum homocysteine as compared to SLR. The HAN exhibited no changes in autonomic function despite significantly elevated (p < 0.05) homocysteine level as compared to SLR. Our findings may have clinical relevance for assessment of susceptibility to cardiovascular risks in HA dwellers, native highlanders and patients with hypoxemia.

Insulin receptor A and Sirtuin 1 synergistically improve learning and spatial memory following chronic salidroside treatment during hypoxia.

Hypoxia has been reported to cause hippocampal neurodegeneration resulting in learning and memory deficits. In the present study, we investigated the potential of salidroside, a glucoside derivative of tyrosol, in ameliorating hypoxia-induced neurodegeneration and memory impairment. Morris water maze test showed improvement in learning and spatial memory of salidroside-treated hypoxic rats correlating with increased dendritic intersections and arborization. Salidroside administration increased phosphorylation of insulin receptor subunit A (IRA) at Y972, Y1162/63, and Y1146 sites and subsequent activation of AMP-activated protein kinase (AMPK) α subunit isoforms pAMPKα1 and pAMPKα2 resulting in mitochondrial biogenesis. Contrarily, silencing of IRA in salidroside-supplemented hypoxic hippocampal cells could not improve cell viability or alter pAMPKα1 and pAMPKα2 expression. Rats administered with salidroside showed elevated expression of phosphorylated cAMP response element-binding protein in the hippocampus. Salidroside administration also resulted in increased sirtuin 1 (SIRT1) activity through a cytochrome P4502E1 (CYP2E1)-regulated mechanism that was independent of pIRA. Taken together, these findings suggest a synergistic role of pIRA and SIRT1 in salidroside-mediated neuroprotection, mitochondrial biogenesis, and cognitive improvement during hypoxia. We propose a novel mechanism for salidroside-mediated neuroprotection in hypoxia.

Domain specific changes in cognition at high altitude and its correlation with hyperhomocysteinemia.

Though acute exposure to hypobaric hypoxia is reported to impair cognitive performance, the effects of prolonged exposure on different cognitive domains have been less studied. The present study aimed at investigating the time dependent changes in cognitive performance on prolonged stay at high altitude and its correlation with electroencephalogram (EEG) and plasma homocysteine. The study was conducted on 761 male volunteers of 25-35 years age who had never been to high altitude and baseline data pertaining to domain specific cognitive performance, EEG and homocysteine was acquired at altitude ≤240 m mean sea level (MSL). The volunteers were inducted to an altitude of 4200-4600 m MSL and longitudinal follow-ups were conducted at durations of 03, 12 and 18 months. Neuropsychological assessment was performed for mild cognitive impairment (MCI), attention, information processing rate, visuo-spatial cognition and executive functioning. Total homocysteine (tHcy), vitamin B12 and folic acid were estimated. Mini Mental State Examination (MMSE) showed temporal increase in the percentage prevalence of MCI from 8.17% on 03 months of stay at high altitude to 18.54% on 18 months of stay. Impairment in visuo-spatial executive, attention, delayed recall and procedural memory related cognitive domains were detected following prolonged stay in high altitude. Increase in alpha wave amplitude in the T3, T4 and C3 regions was observed during the follow-ups which was inversely correlated (r = -0.68) to MMSE scores. The tHcy increased proportionately with duration of stay at high altitude and was correlated with MCI. No change in vitamin B12 and folic acid was observed. Our findings suggest that cognitive impairment is progressively associated with duration of stay at high altitude and is correlated with elevated tHcy in the plasma. Moreover, progressive MCI at high altitude occurs despite acclimatization and is independent of vitamin B12 and folic acid.

Autonomic cardiovascular responses in acclimatized lowlanders on prolonged stay at high altitude: a longitudinal follow up study.

Acute exposure to hypobaric hypoxia at high altitude is reported to cause sympathetic dominance that may contribute to the pathophysiology of high altitude illnesses. The effect of prolonged stay at high altitude on autonomic functions, however, remains to be explored. Thus, the present study aimed at investigating the effect of high altitude on autonomic neural control of cardiovascular responses by monitoring heart rate variability (HRV) during chronic hypobaric hypoxia. Baseline electrocardiography (ECG) data was acquired from the volunteers at mean sea level (MSL) (<250 m) in Rajasthan. Following induction of the study population to high altitude (4500-4800 m) in Ladakh region, ECG data was acquired from the volunteers after 6 months (ALL 6) and 18 months of induction (ALL 18). Out of 159 volunteers who underwent complete investigation during acquisition of baseline data, we have only included the data of 104 volunteers who constantly stayed at high altitude for 18 months to complete the final follow up after 18 months. HRV parameters, physiological indices and biochemical changes in serum were investigated. Our results show sympathetic hyperactivation along with compromise in parasympathetic activity in ALL 6 and ALL 18 when compared to baseline data. Reduction of sympathetic activity and increased parasympathetic response was however observed in ALL 18 when compared to ALL 6. Our findings suggest that autonomic response is regulated by two distinct mechanisms in the ALL 6 and ALL 18. While the autonomic alterations in the ALL 6 group could be attributed to increased sympathetic activity resulting from increased plasma catecholamine concentration, the sympathetic activity in ALL 18 group is associated with increased concentration of serum coronary risk factors and elevated homocysteine. These findings have important clinical implications in assessment of susceptibility to cardio-vascular risks in acclimatized lowlanders staying for prolonged duration at high altitude.

Preoperative blood tests in elective general surgery: cost and clinical implications.

A retrospective observational study was performed in our trust in October 2010 that examined compliance, and the financial and clinical implications of performing inappropriate preoperative blood tests on adult patients prior to elective surgery, against the 2003 NICE guidelines. An unacceptable proportion of inappropriate tests (31.3%) were being performed. None were associated with adverse outcome or changes in management. Based on our results, we estimate that an extrapolated cost of pound 11.2 million is being spent on inappropriate blood tests in NHS England and Wales.

Study of the collateral capacity of the circle of Willis of patients with severe carotid artery stenosis by 3D computational modeling.

This numerical study aims to investigate the capacity of the circle of Wills (CoW) to provide collateral blood supply for patients with unilateral carotid arterial stenosis. The basic 3D geometry of the CoW was reconstructed based on a magnetic resonance angiogram of a normal human subject. A total of 52 computational fluid dynamics simulations were performed for four geometry configurations of the CoW with an artificially inserted axisymmetric stenosis of different luminal area reductions in an internal carotid artery (ICA) under a variety of boundary conditions. The CoW geometric configurations included (a) a normal CoW with all communicating arteries; (b) as model (a) but with enlarged communicating arterial diameters; (c) as (a) but with the ipsilateral posterior communicating artery missing, and (d) as (c) but with enlarged communicating arteries. It is found that the blood perfusion pressure drop between the ipsilateral ICA and the middle cerebral artery (MCA) only becomes significant when the degree of stenosis is greater than 86%. The cerebral autoregulation range varied significantly between the different CoW configurations for the severe stenosis cases. Without causing the flow rates to decrease at the efferent arterial ends, the mean perfusion pressure in the ipsilateral ICA can drop from 100 to 73, 67, 92 and 84 mmHg for the CoW models (a)-(d) with 96% luminal area reduction stenosis, respectively. The additional pathways are able to raise the ipsilateral MCA pressure significantly without reducing the total flow perfusion. Cerebral autoregulation effects were not directly included in the study. Therefore, the findings in the study should be interpreted with cautions when comes to the biological and clinical significance.

Geriatric surgery is about disease, not age.

Maintaining life span and quality of life remains a valid aim of surgery in elderly people. Surgery can be an effective way of restoring both length and quality of life to older people. Minimally invasive techniques and surgery under local anaesthesia make fewer demands on geriatric physiology; given that co-morbidity is a stronger predictor of outcome from surgery than age, this is a significant consideration.

The impact of short term supervised and home-based walking programmes on heart rate variability in patients with peripheral arterial disease.

The aims of the study were to determine whether heart rate variability (HRV) measured at rest and during exercise could be altered by an exercise training programme designed to increase walking performance in patients with peripheral arterial disease. Forty-four volunteers were randomised into 12 weeks of either: supervised walking training twice weekly for 30 min at 75% VO2peak (SU), home-based walking training sessions: twice weekly, 30 min per week (HB) or no exercise (CT). HRV measures were calculated from a 5-min resting ECG. Each patient then underwent maximal, graded exercise treadmill testing. All measures were repeated after 12 weeks. The SU group showed significantly (p < 0.001) increased maximal walking time (MWT) but no change in VO2peak. There were no statistically significant changes in any of the measures of HRV in any group. Effect sizes for change in HRV measures were all very small and in some cases negative. Improved walking performance was not accompanied by central cardiorespiratory or neuroregulatory adaptations in the present study. The lack of any change in HRV was possibly due to either the low intensity or discontinuous nature of exercise undertaken. Key pointsIt is known that exercise can positively influence heart rate variability in some cardiac patients.It is known that exercise can increase walking performance in peripheral vascular disease patients.Exercise training improved walking performance in peripheral vascular disease patients but HRV was unaltered.This may be due to low overall physiological demands on the cardiovascular system or the intermittent nature of the exercise.

Rapid identification and quantification of chlorpheniramine maleate or pheniramine maleate in pharmaceutical preparations by thin-layer chromatography-densitometry.

Thin-layer chromatography (TLC)-densitometry was used to separate, identify, and quantitate chlorpheniramine maleate (CPM) and pheniramine maleate (PM) when present in combination with other drugs in pharmaceutical preparations of tablets, syrups, eye and ear drops, etc. CPM or PM was extracted (tablets, capsules, etc.) or diluted (liquid preparations, if needed) with 80% ethanol and isolated from other ingredients by TLC on silica gel G using cyclohexane-chloroform-methanol-diethylamine (4.5 + 4.0 + 0.5 + 1.0, v/v) as the mobile phase. Separated CPM and PM were detected under shortwave ultraviolet light and quantitated by scanning densitometry at 260 nm. Recoveries of CPM and PM were 100.09+/-0.77% and 100.09+/-0.87%, respectively.