A FULLY INTEGRATED NEURAL SIGNAL ACQUISITION AMPLIFIER FOR EPILEPTIC SEIZURE PREDICTION

This paper deals with the design of low power low noise neural signal amplifier for Epileptic Seizure Prediction. The advent of Micro-electro Arrays has driven the need for implantable electronic circuitry to detect those Extracellular neural signals (ENG). We proposed a preamplifier of fully differential Low Noise Amplifier (LNA) with gm boosting in order to enhance the gain as well as reduce the power consumption. Low frequency high pass function has been realized with anti-parallel Diode connected PMOS. Simulation results shows that the input referred noise is 1.24μVrms from 100Hz to 5 KHz, mid-band voltage gain of 44.6dB, and the power consumption is 18.74μw. A new signal processing circuit has been designed extract the seizure onset. The results are validated using Cadence spectre simulator with 180nm technology. Simulation results show that this implantable amplifier is suitable for Epileptic seizure prediction

Study of prescribing pattern of antihypertensive drugs in diabetic patients in a tertiary care centre, Vizianagaram, India

Background: Diabetes mellitus (DM) and Hypertension (HTN) are the two major chronic disorders frequently coexisting, with increased incidence with age. HTN is about twice as common in patients with DM. Prescribing pattern are powerful tools to ascertain the role of drugs in society. There are many variations in prescribing patterns of antihypertensive drugs in patients with HTN and DM. Since these patients requires lifelong treatment it has enormously increased the burden of patients particularly in developing countries like India. Physician needs to be more concerned while choosing drugs for the patients with HTN and DM. In a tertiary care hospital, there is a real need for drug utilization study to determine the appropriate, more safe and effective patterns of drug therapy among diabetic hypertensive patients.Methods: A Cross sectional observational study was conducted in Maharajah’s Institute of Medical Sciences from December 2016 to May 2018. A total of 360 prescriptions of the patients with hypertension and coexisting diabetes were analyzed. The prescriptions prescribed to these patients were collected, assessed and the following parameters were noted. The treatment pattern of different group of drugs for HTN with co-existing DM was evaluated. The intended work was divided into three steps: Step 1: To collect the prescriptions of hypertensive patients with DM. Step 2: To separate the prescriptions prescribing anti hypertensive Drugs. Step 3: To statistically analyze the prescriptions. Relevant information was recorded in a structured proforma & data was evaluated.Results: In this study it was found that 36% of the patients were in the age group of 51-60 years with female preponderance among diabetic hypertensive patients. 77% of patients were treated with single antihypertensive drug and 23% of patients were treated with antihypertensive drug combinations. In monotherapy, telmisartan was most commonly prescribed. In combination therapy, amlodipine and telmisartan followed by amlodipine and atenolol were used.Conclusions: In this study monotherapy was preferred compared to combination therapy and adherence to the JNC 7 guidelines was good except in case of usage of diuretics

Clinical Study Long-Term Outcomes of Cultivated Limbal Epithelial Transplantation: Evaluation and Comparison of Results in Children and Adults

. Purpose. To compare the long-term clinical outcomes of cultivated limbal epithelial transplantation (CLET) in children and adults with limbal stem cell deficiency. Design. Retrospective case series. Methods. Case records of patients with limbal stem cell deficiency (LSCD) who underwent CLET from April 2004 to December 2014 were studied. Outcome measures were compared in terms of anatomical success and visual improvement. Parameters for total anatomical success were avascular, epithelized, and clinically stable corneal surface without conjunctivalization, whereas partial anatomical success was considered when mild vascularization (sparing centre of cornea) and mild conjunctivalization were noted along with complete epithelization. Results. A total of 62 cases underwent the CLET procedure: 38 (61.3%) were children and 24 (38.7%) were adults. Patients with unilateral LSCD (33 children and 21 adults) had autografts and those with bilateral LSCD (5 children and 3 adults) had allografts. Amongst the 54 autografts partial and total anatomical success were noted in 21. 2% and 66.6% children, respectively, and 19.0% and 80.9% in adults, respectively ( value 0.23). Visual improvement of 1 line and ≥2 lines was seen in 57.5% and 21.2% children, respectively, and 38% and 38% in adults, respectively ( value 0.31). Conclusion. Cultivated limbal epithelial transplantation gives good long-term results in patients with LSCD and the outcomes are comparable in children and adults

Indications and outcome of repeat penetrating keratoplasty in India

BACKGROUND: Repeat penetrating keratoplasty is quite often required as there is high chance of failure of the primary graft particularly in the developing world. We planned a study to analyze the indications and outcome of repeat penetrating keratoplasty in a tertiary care centre in India. METHODS: A retrospective analysis of all the patients who underwent repeat penetrating keratoplasty, between January 1999 and December 2001 was performed. The parameters evaluated were indication for the primary penetrating keratoplasty, causes of failure of the previous graft, and final visual outcome and clarity of the repeat corneal grafts. RESULTS: Of fifty-three eyes of 50 patients with repeat penetrating keratoplasty (three patients underwent bilateral corneal regrafts), 37 eyes had undergone one regraft each, 14 eyes two regrafts and two eyes had three regrafts. The follow-up of the patients ranged from one to three years. The most common primary etiologic diagnosis was vascularized corneal scars (66%), of which the scars related to infection were most common (68.5%). Twenty-eight regrafts (52.8%) remained clear at a mean follow-up of 1.54 ± 0.68 years, of which 25 were single regrafts (89.3%). The commonest cause of failure of regraft was infection to the corneal graft (recurrence of herpetic infection in 9 eyes and perforated graft ulcers in 3 eyes). Three (18.6%) of the 16 eyes with multiple corneal regrafts achieved a BCVA of 6/60. Overall, only five eyes (all with single regraft) achieved a BCVA of 6/18 or better at the end of follow-up. CONCLUSION: Graft infection is the leading cause of failure of repeat keratoplasty in this part of the world. Prognosis for visual recovery and graft survival is worse in eyes undergoing multiple regrafts

Antimicrobial Peptides Derived from Ascidians and Associated Cyanobacteria

Ascidians belonging to Phylum Chordata are the most largest and diverse of the Sub-phylum Tunicata (Urochordata). Marine ascidians are one of the richest sources of bioactive peptides. These bioactive peptides from marine ascidians are confined to various types of structures such as cyclic peptides, acyclic peptides (depsipeptides), linear helical peptides with abundance of one amino acid (proline, trytophane, histidine), peptides forming hairpin like beta sheets or α-helical/β-sheet mixed structures stabilized by intra molecular disulfide bonding. Cyanobactins are fabricated through the proteolytic cleavage and cyclization of precursor peptides coupled with further posttranslational modifications such as hydroxylation, glycosylation, heterocyclization, oxidation, or prenylation of amino acids. Ascidians are known to be a rich source of bioactive alkaloids. β-carbolines form a large group of tryptophan derived antibiotics. Pyridoacridines from ascidians are tetra- or penta- cyclic aromatic alkaloids with broad range of bioactivities. Didemnidines derived from ascidian symbiotic microbes are inhibitors of phospholipase A2 and induce cell apoptosis. Meridianins are indulged in inhibiting various protein kinases such as, cyclindependent kinases, glycogen synthase kinase-3, cyclic nucleotide dependent kinases, casein kinase, and also implicate their activity of interfering with topoisomerase, altering the mitochondrial membrane potential and binding to the DNA minor groove to inhibit transcriptional activation. Most of these bioactive compounds from ascidians are already in different phases of the clinical and pre-clinical trials. They can be used for their nutraceutical values because of their antineoplastic, antihypertensive, antioxidant, antimicrobial, cytotoxic, antibacterial, antifungal, insecticidal, anti-HIV and anti-parasitic, anti-malarial, anti-trypanosomal, anti-cancer etc. This chapter mostly deals with antibacterial compounds from ascidian and their associate symbiotic cyanobacteria