Synthetic Pyrethroid effect on blood plasma biomarker enzymes and histological changes in Catla catla

Alpha‐cypermethrin is an isoform of cypermethrin; it is an active pyrethroid used extensively to control a wide range of pests in agriculture and animal breeding. In this study four groups of six fish were examined. The first group served as a control in fresh water alone, with no pyrethroid. The second, third and fourth groups were exposed to alpha‐cypermethrin for 4, 8 and 96 h respectively. At the end of the each exposure period, the fish were sacrificed, and the required muscle tissues were collected for histological examination. The blood was drawn with heparinized needles and processed for serum enzymatic studies. Serum enzymes such as aspartate transaminase (AST), alanine transaminase (ALT), amylase, acid phosphatase (ACP) and gamma‐glutamyl transpeptidase (GGT) were measured at 4, 8 and 96 h. AST enzyme activity was significantly increased at 4 h, whereas ALT and amylase enzyme activities were significantly reduced at all the time points. ACP enzyme activity was significantly reduced at 4 and 8 h, whereas GGT enzyme activity was significantly increased at all the time points. Hepatocyte cytoplasmic vacuolisation and degeneration, rupture of blood vessels, and necrosis was found at all time points. Congestion of blood vessels, bulging, distortion of filaments, erosion and disintegration of blood corpuscles and hyperplasia of epithelium were found in treated gills at 4, 8 and 96 h. Breakdown of muscle fibres, vacuolation and accumulation of lipids and melanin in white muscle were observed in treated fish muscle at 4, 8 and 96 h.     

Dynamic imaging of coherent sources

Electric source imaging allows localization of sources in the brain underlying frequency-associated EEG patterns detected on the scalp EEG. New algorithms have substantially improved the localization power of the EEG. Dynamic imaging of coherent sources (DICS) is one of these solutions. This algorithm uses a spatial filter to map power and coherence estimates of oscillatory brain activity. In this focus article, we explain the DICS method and summarize studies representing the ability of DICS to detect cortical and subcortical electric sources and neuronal networks associated with absence seizures, photoparoxysmal responses and hypsarrhythmia. By applying renormalized partial directed coherence (RPDC), the information flow between 2 sources can be described, which contributes to a better understanding of networks underlying different forms of epilepsy.     

Subcortical substrates of TMS induced modulation of the cortico-cortical connectivity

BackgroundTranscranial magnetic stimulation (TMS) can modulate transiently the physiological brain oscillations, e.g. the alpha rhythm. It has been hypothesized that this effect is not limited to the stimulated region but involves subcortical and distant cortical areas.MethodsWe applied single pulse TMS to the primary motor cortex (M1) of healthy subjects to interfere the cortical oscillatory activity recorded by simultaneous EEG and calculated the cortico-cortical coherence and power in the alpha and beta band. To study the structural substrate of the functional connectivity we performed diffusion tensor imaging and fractional anisotropy analysis (FA). To capture the pathways involved we applied probabilistic tractography to reconstruct the entire network.ResultsSuprathreshold TMS of M1 induced a consistent enhancement of interhemispheric cortico-cortical alpha band coherence that lasted ca. 175 ms. after the pulse has been applied. The changes were confined to the interhemispheric central EEG electrodes (i.e. C3-C4). There were no consistent changes in the beta band. Power analysis revealed a longer lasting increase in the beta band after TMS pulses. A cluster in the contralateral thalamus showed a linear relationship between regional FA and TMS induced change in alpha band coherence. Probabilistic tractography presents the transcallosal and the contralateral thalamocortical pathways as essential for the observed oscillatory synchronisation.ConclusionTMS induces an enhancement of oscillatory interaction between corresponding central regions of both hemispheres in the alpha band. The contralateral thalamus, transcallosal fibres and the contralateral thalamocortical pathways may constitute critical brain structures mediating the TMS induced change in oscillatory coupling.     

Neuroprotective effect of gadolinium: a stretch-activated calcium channel blocker in mouse model of ischemia–reperfusion injury

The present study was designed to investigate the potential of gadolinium, a stretch-activated calcium channel blocker in ischemic reperfusion (I/R)-induced brain injury in mice. Bilateral carotid artery occlusion of 12 min followed by reperfusion for 24 h was given to induce cerebral injury in male Swiss mice. Cerebral infarct size was measured using triphenyltetrazolium chloride staining. Memory was assessed using Morris water maze test and motor incoordination was evaluated using rota-rod, lateral push, and inclined beam walking tests. In addition, total calcium, thiobarbituric acid reactive substance (TBARS), reduced glutathione (GSH), and acetylcholinesterase (AChE) activity were also estimated in brain tissue. I/R injury produced a significant increase in cerebral infarct size. A significant loss of memory along with impairment of motor performance was also noted. Furthermore, I/R injury also produced a significant increase in levels of TBARS, total calcium, AChE activity, and a decrease in GSH levels. Pretreatment of gadolinium significantly attenuated I/R-induced infarct size, behavioral and biochemical changes. On the basis of the present findings, we can suggest that opening of stretch-activated calcium channel may play a critical role in ischemic reperfusion-induced brain injury and that gadolinium has neuroprotective potential in I/R-induced injury.     

Cortical correlates of the basic and first harmonic frequency of Parkinsonian tremor

ObjectiveIt has been hypothesized that the basic and first harmonic frequency of Parkinsonian tremor are somewhat independent oscillations the biological basis of which remains unclear.MethodsWe recorded 64-channel EEG in parallel with EMG of the forearm muscles most affected by rest tremor in 21 PD patients. EMG power spectrum, corticomuscular coherence spectra and EEG power spectra for each EEG electrode were calculated. The dynamics of the coherence and relative EMG and EEG power at the basic (tremor) frequency were calculated by a sliding, overlapping window analysis. Corticomuscular delays and direction of interaction were analysed by the maximizing coherence method for narrow band signals.ResultsThe contralateral EEG electrodes with maximal coherence were different for the basic and first harmonic frequency. The dynamical coherence curves showed non-parallel time courses for the two frequencies. The mean EEG-EMG and EMG-EEG delays were all around 15–20 ms but significantly longer for the first harmonic than for the basic frequency.ConclusionsOur data indicate different cortical representations and corticomuscular interaction of the basic and first harmonic frequencies of Parkinsonian tremor.SignificanceSeparate central generators seem to contribute to the tremor via different pathways. Further studies on this complex tremor network are warranted.     

Changes in brain functional connectivity patterns are driven by an individual lesion in MS: a resting-state fMRI study

Diffuse inflammation in multiple sclerosis (MS) extends beyond focal lesion sites, affecting interconnected regions; however, little is known about the impact of an individual lesion affecting major white matter (WM) pathways on brain functional connectivity (FC). Here, we longitudinally assessed the effects of acute and chronic lesions on FC in relapsing-remitting MS (RRMS) patients using resting-state fMRI. 45 MRI data sets from 9 RRMS patients were recorded using 3T MR scanner over 5 time points at 8 week intervals. Patients were divided into two groups based on the presence (n?=?5; MS+) and absence (n?=?4; MS-) of a lesion at a predilection site for MS. While FC levels were found not to fluctuate significantly in the overall patient group, the MS+ patient group showed increased FC in the contralateral cuneus and precuneus and in the ipsilateral precuneus (p?<?0.01, corrected). This can be interpreted as the recruitment of intact cortical regions to compensate for tissue damage. During the study, one patient developed an acute WM lesion in the left posterior periventricular space. A marked increase in FC in the right pre-, post-central gyrus, right superior frontal gyrus, the left cuneus, the vermis and the posterior and anterior lobes of the cerebellum was noted following the clinical relapse, which gradually decreased in subsequent follow-ups, suggesting short-term functional reorganization during the acute phase. This strongly suggests that the lesion-related network changes observed in patients with chronic lesions occur as a result of reorganization processes following the initial appearance of an acute lesion.     

Transventricular mitral commissurotomy in critical mitral stenosis during pregnancy

The management of a pregnant patient with mitral stenosis is a subject of debate with regards to the optimal type of treatment and the time of intervention. We performed trans-ventricular mitral commissurotomy (TVMC) either as an isolated procedure in the second trimester, or in combination with Cesarian section at term. We retrospectively analyzed our experience with TVMC during pregnancy and formulated a protocol for its management. Between January 1987 and April 2002, fifty one patients underwent TVMC for critical mitral stenosis during pregnancy. In 38 patients, elective TVMC was performed during the second trimester, while in 12, it was performed as an initial procedure along with Cesarian section at term. One patient had an emergency TVMC in the second trimester when she presented with intractable acute pulmonary edema. There were no maternal mortalities. Three patients who developed post-operative mitral regurgitation were managed conservatively. Another two patients who developed cerebral embolism with hemiplegia recovered completely without any neurological deficit. There was only one fetal death in a patient where TVMC was performed as an emergency procedure for acute pulmonary edema. We conclude that TVMC in pregnancy is a safe, cost effective alternative in critical mitral stenosis complicating pregnancy.     

Effect of cypermethrin, carbendazim and their combination on male albino rat serum

Alpha-cypermethrin and carbendazim are synthetic; α-cypermethrin belongs to a class of synthetic pyrethroids and carbendazim belongs to the class of carbamate fungicides. The current study was carried out to evaluate the low-dose exposure of individual and mixed forms of cypermethrin and carbendazim. α-cypermethrin was used at 0.06, 0.12, 0.30 and 0.60 mg/kg body weight (bw), carbendazim was at 0.48, 0.96, 2.4 and 4.8 mg/kg bw and combined doses (cypermethrin: 0.06, 0.12, 0.30 and 0.60 mg/kg.bwt + carbendazim: 0.48, 0.96, 2.4 and 4.8 mg/kg.bwt) for 12 h and 24 h. The biochemical parameters and serum markey enzymes were analysed. The biochemical parameters include serum total protein, glucose, cholesterol, urea, uric acid, calcium, phosphorous, albumin and creatinine and serum marker enzymes such as alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP), γ-glutamyl transpeptidase (GGT) and amylase were ascertained. Results indicated simultaneous changes in serum marker enzyme activity (ALT, AST, ALP, GGT and amylase) and biochemical markers (*P < 0.05, **P < 0.01 and ***P < 0.001). The experimental results indicate that even low-dose use of the synthetic pyrethroid carbamate and their combined form results in consequential negative effects on cell function.     

Mitochondrial Dependent Apoptosis: Ameliorative Effect of Flunarizine on Ischemia–Reperfusion of Celiac Artery-Induced Gastric Lesions in the Rat

Objectives  

Ischemia–reperfusion is a major event for induction of cellular apoptosis. Apoptosis is due to the activation of death receptor and/or mitochondrial pathways. Mitochondrial permeability transition pore opening is the cause of apoptosis. In our present study, we tried to evaluate the role of flunarizine in ischemia and reperfusion of celiac artery-induced gastric lesion in the rat.