46 research outputs found
Histological Characterization of Inter Ictal Epileptiform Discharges Generating Brain Regions using a Preclinical Model of Focal Cortical Dysplasia
Current clinical practice of resective surgery in focal epilepsy involves electroencephalogram (EEG) brain source imaging to localize irritative brain areas from where Inter-ictal epileptiform discharges (IEDs) emerge, useful to localize the seizures-onset zones. Unfortunately, there are no previous systematic studies to characterize the pathophysiological mechanisms and abnormal cellular substrates in these irritative areas since histological data are available only from the final resective zones. To address this issue we applied a combination of EEG brain imaging described by Bae et al. (2015) using cutting-edge technology for high-density scalp EEG in rodents and histological analysis on a chronic rat model of focal cortical dysplasia. Post-mortem brain sections were stained for anatomical, functional and inflammatory biomarkers. Abnormal anatomical structures and increased expression of inflammatory biomarkers were found in the irritative regions. We conclude that IED-based brain source imaging can help to localize abnormal tissues highly prospective for epileptogenesis
Brain Source Imaging in Preclinical Rat Models of Focal Epilepsy using High-Resolution EEG Recordings
Electroencephalogram (EEG) has been traditionally used to determine which brain regions are the most likely candidates for resection in patients with focal epilepsy. This methodology relies on the assumption that seizures originate from the same regions of the brain from which interictal epileptiform discharges (IEDs) emerge. Preclinical models are very useful to find correlates between IED locations and the actual regions underlying seizure initiation in focal epilepsy. Rats have been commonly used in preclinical studies of epilepsy1; hence, there exist a large variety of models for focal epilepsy in this particular species. However, it is challenging to record multichannel EEG and to perform brain source imaging in such a small animal. To overcome this issue, we combine a patented-technology to obtain 32-channel EEG recordings from rodents2 and an MRI probabilistic atlas for brain anatomical structures in Wistar rats to perform brain source imaging. In this video, we introduce the procedures to acquire multichannel EEG from Wistar rats with focal cortical dysplasia, and describe the steps both to define the volume conductor model from the MRI atlas and to uniquely determine the IEDs. Finally, we validate the whole methodology by obtaining brain source images of IEDs and compare them with those obtained at different time frames during the seizure onset
Herpes Zoster Ophthalmicus in Healthy 13-month Infant: An Unforeseen Scenario
Herpes zoster (HZ) as well as varicella are caused by varicella-zoster virus. It is uncommon in children. Cases have been reported in literature among all ages from neonate to old age. We report this case of HZ ophthalmicus in a healthy child born to healthy mother with a history of varicella infection in the third trimester (7th month of gestation). Early diagnosis and treatment reduce complications. Preconceptional varicella-zoster vaccine is also a matter of concern
Evaluation of anti-viral activity of Jatropha curcas leaf extracts against potentially drug-resistant HIV isolates
Perception and attitudes of medical students toward communication, chronic disease and death
Background: Medical students of today’s world found difficulty in communication when they faced with dying patients, how they would feel, what are their perception about caring of patients with chronic disease. These are often unspoken and neglected issues.Methods: It was a cross-sectional comparative questionnaire based survey of the 2nd year medical students and interns. Students were evaluated using a questionnaire consisting of 15 Likert type statements.Results: Completed questionnaire received from 89 out of 100 students. All students strongly agreed upon the commutation with patients. Interns (37.03%) were strongly disagreed (p=0.001) on not curing the patient is a failure of doctors. Interns (32.58%) were significantly more likely to be less worried (p<0.01) about death of the patient and to indicate cancer is a non-curable disease (p<0.001) when compared to 2nd MBBS. Students from both the groups distressed, while communicating with dying patients and relatives of dying patients.Conclusion: Perception of students regarding caring of chronically ill-patients and death related issues needs improvement. We believe that integrating different teaching strategies and training programs regarding this issue should begin at early stages of undergraduate medical curriculum
Intense blue-emitting Ca5Al8O14 : Eu phosphor for mercury free lamp
The calcium aluminates doped with Eu ions, Ca5Al8O14 : Eu, phosphors are prepared by the
combustion method. The formation of crystalline aluminates was confirmed by X-ray diffraction pattern. The
prepared phosphors were characterized by SEM, TGA, DTA, particle size analyzer and Photoluminescence (PL)
techniques. From the UV-excited luminescence spectra it was found that the Eu ions acts as a luminescent
centre with luminescence at the blue (λmax = 470 nm) region due to 4f 65d1 → 4f 7 transition. The excitation
spectra show the broad band at 355 nm wavelength (λem = 470 nm). The excitation 355 nm is a mercury free
excitation and therefore Ca5Al8O14 : Eu may be useful for the solid state lighting phosphor in lamp industry.Intense blue-emitting Ca5Al8O14 : Eu phosphor for mercury free lamp
Abhay D Deshmukh1*, S J Dhoble1, S V Godbole2, M K Bhide2 and D R Peshwe3
1Kamla Nehru College, Sakkardara Square, Nagpur-440 009, Maharashtra, India
2Spectroscopy Section, Radiochemistry Division, Bhabha Atomic Research Centre,
Mumbai-400 085, India
3Department of Metallurgical and Materials Engineering, VNIT, Nagpur-440 011,
Maharashtra, India
E-mail : [email protected] Nehru College, Sakkardara Square, Nagpur-440 009, Maharashtra, India
2Spectroscopy Section, Radiochemistry Division, Bhabha Atomic Research Centre,
Mumbai-400 085, India
3Department of Metallurgical and Materials Engineering, VNIT, Nagpur-440 011,
Maharashtra, Indi
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Dysfunction of neurovascular/metabolic coupling in chronic focal epilepsy
In this study, we aim to evaluate the mechanisms underlying the neuro-vascular/metabolic coupling in the epileptogenic cortices of rats with chronic focal epilepsy. To that end, we first analyzed intracranial recordings (electrophysiology, laser Doppler flowmetry and optical imaging) obtained from the seizure onset zones during ictal periods and then used these data to fit a metabolically-coupled balloon model. This biophysical model is an extension of the standard balloon model with modulatory effects of changes in tissue oxygenation, capillary dynamics and variable O2 extraction fraction. As previously reported using acute seizure models, we found that there is a significant higher contribution from high local field potential frequency bands to the cerebral blood flow (CBF) responses in the epileptogenic cortices during ictal neuronal activities. The hemodynamic responses associated with ictal activities were distance-dependent with regard to the seizure focus, though varied in profiles from those obtained from acute seizure models. Parameters linking the CBF and relative concentration of deoxy-hemoglobin to neuronal activity in the biophysical model were significantly different between epileptic and normal rats. In particular, we found that the coefficient associated with the strength of the functional hyperemic response was significantly larger in the epileptogenic cortices, although changes in hemoglobin concentration associated with ictal activity reflected the existence of a significantly higher baseline for oxygen metabolism in the epileptogenic cortices
Luminomagnetic bifunctionality of Mn2+-bonded graphene oxide/reduced graphene oxide two dimensional nanosheets
Herein, we report the luminomagnetic bifunctional properties of two-dimensional (2D) Mn2+ bonded graphene oxide (GO)/reduced graphene oxide (RGO) nanosheets synthesized using a facile route of oxidation followed by a solvothermal reduction method. Photoluminescence (PL) studies (excited by different wavelengths) revealed that the resonant energy transfer between Mn2+ and sp(3)/sp(2) clusters of GO/RGO is responsible for the enhancement of emissions. Moreover, pH-sensitive PL behaviors have also been investigated in detail. The ferromagnetic behavior is believed to arise due to defects in Mn2+ bonded GO composites. Thus, present reduction method provides a direct route to tune and enhance the optical properties of GO and RGO nanosheets bonded with Mn2+ ions, which creates an opportunity for various technological applications