A Study Comparing Three Different Doses of Neostigmine (50μgm/kg, 25μgm/kg, 12.5μgm/kg) as Reversal Agent for Facilitation of Recovery from Residual Neuromuscular Blockade with Atracurium

INTRODUCTION: Anti-cholinestrase drugs like neostigmine are given at the end of surgical procedures to accelerate recovery from residual neuromuscular blockade produced by non-depolarising neuromuscular blocking drugs. When atracurium is used as muscle relaxant which has a novel mechanism of excretion which does not depend either on renal or hepatic function. The atracurium induced muscle relaxation can recover spontaneously but slowly. Anti- cholinesterase is needed just to speed up recovery from residual blockade. Since the reversal agent like neostigmine has its own drawbacks of muscarinic side effects of bradycardia , hypotension, increased glandular secretions. The dose of neostigmine reduction might help in reducing these side-effects without affecting its purpose of reversing the residual neuromuscular blockade. In addition use of neuromuscular monitor , helps us to objectively judge the recovery of the neuromuscular junction , from residual non – depolarizing blockade when used in addition to the clinical signs of recovery of muscle power. AIM OF THE STUDY: To study and compare three different doses of neostigmine as reversal agent to residual neuromuscular blockade of atracurium. 1. On recovery of residual neuromuscular blockade produced by atracurium (intubating dose of 0.5 mg/kg, top-up dose of 0.15 mg/kg). 2. On the haemo- dynamic changes. 3. On the adverse side effects. MATERIALS AND METHODS: This study was conducted at Government Stanley Hospital, Chennai in the patients undergoing adeno-tonsillectomy, and tonsillectomy. After institutional approval and informed consent, 90 patients were enrolled in the study. INCLUSION CRITERIA: All ASA physical status (1 & 2) patients aged between 5 – 15 years scheduled for tonsillectomies and adeno - tonsillectomies under general anaesthesia. EXCLUSION CRITERIA: 1. Neuromuscular disease. 2. Patients receiving any medication known to interact with neuromuscular blocking agents 3. Known allergy to any medication. 4. Anticipated difficult intubation. 5. Morbidly obese. 6. ASA physical status 3, 4, & and 5. 7. Age below 5 years and more than 15 years. STATISTICAL ANALYSIS: The data was computed and all values expressed as mean +/- S.D. The data was analyzed using student independent t test , anova F test and Chi-square test as appropriate. SUMMARY: 1. The lower doses of neostigmine (25 μgm/kg, 12.5 μgm/kg) provided equally effective reversal of atracurium induced neuromuscular blockade as the higher dose (50μgm/kg). 2. The mean time required for recovery of adequate muscle power after neostigmine in all three groups were approximately equal and difference among them were statistically insignificant (5.97+/-1.7515, 6.2+/-1.95. 6.93+/-2.49). 3. The mean time required for extubation in all the three groups approximately equal (7.93+/-1.837, 8.27+/-2.196, 8.93+/-2.572 respectively). 4. The mean time for the recovery of the two responses to DBS without any fade in response was also approximately equal in all the three groups (4.83+/-1.821, 5.63+/-1.866, 6.03+/-2.236). 5. The heart rate showed a significantly lower mean value in group A (neostigmine 50μgm/kg) 90.63+/-8.37 compared with basal value 109.76+/-10.9. 6. The group A had 2 patients with significant bradycardia who received the higher dose (50μgm/kg) of neostigmine. 7. No patient in any of the three groups had side effects like nausea, vomiting, or hypotension. CONCLUSION: 1. Satisfactory facilitation of recovery from residual neuromuscular blockade produced by atracurium (given in intubating dose 0.5mg/kg and incremental dose of 0.15 mg/kg) are achieved with reduced doses of neostigmine (25μgm/kg and 12.5 μgm/kg). 2. Lower doses of neostigmine avoid the significant decrease in heart rate

Early assessment of lung function in coronavirus patients using invariant markers from chest X-rays images

The primary goal of this manuscript is to develop a computer assisted diagnostic (CAD) system to assess pulmonary function and risk of mortality in patients with coronavirus disease 2019 (COVID-19). The CAD system processes chest X-ray data and provides accurate, objective imaging markers to assist in the determination of patients with a higher risk of death and thus are more likely to require mechanical ventilation and/or more intensive clinical care.To obtain an accurate stochastic model that has the ability to detect the severity of lung infection, we develop a second-order Markov-Gibbs random field (MGRF) invariant under rigid transformation (translation or rotation of the image) as well as scale (i.e., pixel size). The parameters of the MGRF model are learned automatically, given a training set of X-ray images with affected lung regions labeled. An X-ray input to the system undergoes pre-processing to correct for non-uniformity of illumination and to delimit the boundary of the lung, using either a fully-automated segmentation routine or manual delineation provided by the radiologist, prior to the diagnosis. The steps of the proposed methodology are: (i) estimate the Gibbs energy at several different radii to describe the inhomogeneity in lung infection; (ii) compute the cumulative distribution function (CDF) as a new representation to describe the local inhomogeneity in the infected region of lung; and (iii) input the CDFs to a new neural network-based fusion system to determine whether the severity of lung infection is low or high. This approach is tested on 200 clinical X-rays from 200 COVID-19 positive patients, 100 of whom died and 100 who recovered using multiple training/testing processes including leave-one-subject-out (LOSO), tenfold, fourfold, and twofold cross-validation tests. The Gibbs energy for lung pathology was estimated at three concentric rings of increasing radii. The accuracy and Dice similarity coefficient (DSC) of the system steadily improved as the radius increased. The overall CAD system combined the estimated Gibbs energy information from all radii and achieved a sensitivity, specificity, accuracy, and DSC of 100%, 97% ± 3%, 98% ± 2%, and 98% ± 2%, respectively, by twofold cross validation. Alternative classification algorithms, including support vector machine, random forest, naive Bayes classifier, K-nearest neighbors, and decision trees all produced inferior results compared to the proposed neural network used in this CAD system. The experiments demonstrate the feasibility of the proposed system as a novel tool to objectively assess disease severity and predict mortality in COVID-19 patients. The proposed tool can assist physicians to determine which patients might require more intensive clinical care, such a mechanical respiratory support

Challenges in conducting trials for pediatric tuberculous meningitis: lessons from the field

SETTING: TBM-KIDS is a phase I/II trial enrolling children with tuberculous meningitis (TBM) in three tertiary referral centers in India and Malawi. OBJECTIVE: To describe the challenges encountered in conducting the first randomized clinical trial of antimicrobial agents in pediatric TBM. DESIGN: The sources of the data were primarily monthly trial reports, non-enrollment case report forms, study diaries and registers maintained for recruitment, experiences shared by key team members during regular study calls and comments from site review visits. We reviewed, broadly categorized, and describe in detail the challenges encountered by study teams in trial implementation. RESULTS: Over 17 months, 3371 children with clinical presentations consistent with meningoencephalitis or undergoing lumbar puncture were assessed for eligibility; 21 (<1%) met enrollment criteria. We encountered challenges related to diagnosis, management of sick children, large catchment areas, adverse event attribution, concomitant medications, infrastructure requirements, expensive pediatric formulations with short expiry, and detection of treatment response in a highly variable disease across the age continuum. Training and adaptation of tools for neurocognitive and neurologic function assessment were necessary. Special care was undertaken to explain study participation to distraught caregivers and manage children longitudinally. CONCLUSION: Interventional trials in pediatric TBM are challenging but are critically important for improving the treatment of a disease that disables children physically, cognitively and emotionally. Sharing these challenges may help to address them more effectively as a TB research community and to advance treatments for this at-risk population

Histidine Hydrogen-Deuterium Exchange Mass Spectrometry for Probing the Microenvironment of Histidine Residues in Dihydrofolate Reductase

Histidine Hydrogen-Deuterium Exchange Mass Spectrometry (His-HDX-MS) determines the HDX rates at the imidazole C(2)-hydrogen of histidine residues. This method provides not only the HDX rates but also the pK(a) values of histidine imidazole rings. His-HDX-MS was used to probe the microenvironment of histidine residues of E. coli dihydrofolate reductase (DHFR), an enzyme proposed to undergo multiple conformational changes during catalysis.Using His-HDX-MS, the pK(a) values and the half-lives (t(1/2)) of HDX reactions of five histidine residues of apo-DHFR, DHFR in complex with methotrexate (DHFR-MTX), DHFR in complex with MTX and NADPH (DHFR-MTX-NADPH), and DHFR in complex with folate and NADP+ (DHFR-folate-NADP+) were determined. The results showed that the two parameters (pK(a) and t(1/2)) are sensitive to the changes of the microenvironment around the histidine residues. Although four of the five histidine residues are located far from the active site, ligand binding affected their pK(a), t(1/2) or both. This is consistent with previous observations of ligand binding-induced distal conformational changes on DHFR. Most of the observed pK(a) and t(1/2) changes could be rationalized using the X-ray structures of apo-DHFR, DHFR-MTX-NADPH, and DHFR-folate-NADP+. The availability of the neutron diffraction structure of DHFR-MTX enabled us to compare the protonation states of histidine imidazole rings.Our results demonstrate the usefulness of His-HDX-MS in probing the microenvironments of histidine residues within proteins

Novel substituted methylenedioxy lignan suppresses proliferation of cancer cells by inhibiting telomerase and activation of c-myc and caspases leading to apoptosis

Conventional solvent fractionation and bioactivity based target assays were used to identify a new anti-cancer molecule from Phyllanthus urinaria, a herbal medicinal plant used in South India. At each step of the purification process the different fractions that were isolated were tested for specific anti-proliferative activity by assays measuring the inhibition of [3H]thymidine incorporation, and trypan blue drug exclusion. The ethyl acetate fraction that contained the bioactivity was further purified and resolved by HPLC on a preparative column. The purity of each of the fractions and their bioactivity were checked. Fraction 3 demonstrated a single spot on TLC and showed maximum anti-proliferative activity. This fraction was further purified and the structure was defined as 7′-hydroxy-3′,4′,5,9,9′-pentamethoxy-3,4-methylene dioxy lignan using NMR and mass spectrometry analysis. The pure compound and the crude ethyl acetate fraction which showed anti-proliferative activities were examined for ability to target specific markers of apoptosis like bcl2, c-myc and caspases and for effects on telomerase. Four specific cancer cell lines HEp2, EL-1 monocytes, HeLa and MCP7 were used in this study. The results indicate that 7′-hydroxy-3′,4′,5,9,9′-pentamethoxy-3,4-methylene dioxy lignan was capable of inhibiting telomerase activity and also could inhibit bcl2 and activate caspase 3 and caspase 8 whose significance in the induction of apoptosis is well known. We believe that this compound could serve as a valuable chemotherapeutic drug after further evaluations

Human umbilical cord mesenchymal stem cell-derived extracellular vesicles ameliorate airway inflammation in a rat model of Chronic Obstructive Pulmonary Disease (COPD)

Background Chronic obstructive pulmonary disease (COPD) is an incurable and debilitating chronic disease characterized by progressive airflow limitation associated with abnormal levels of tissue inflammation. Therefore, stem cell-based approaches to tackle the condition are currently a focus of regenerative therapies for COPD. Extracellular vesicles (EVs) released by all cell types are crucially involved in paracrine, extracellular communication. Recent advances in the field suggest that stem cell-derived EVs possess a therapeutic potential which is comparable to the cells of their origin. Methods In this study, we assessed the potential anti-inflammatory effects of human umbilical cord mesenchymal stem cell (hUC-MSC)-derived EVs in a rat model of COPD. EVs were isolated from hUC-MSCs and characterized by the transmission electron microscope, western blotting, and nanoparticle tracking analysis. As a model of COPD, male Sprague-Dawley rats were exposed to cigarette smoke for up to 12 weeks, followed by transplantation of hUC-MSCs or application of hUC-MSC-derived EVs. Lung tissue was subjected to histological analysis using haematoxylin and eosin staining, Alcian blue-periodic acid-Schiff (AB-PAS) staining, and immunofluorescence staining. Gene expression in the lung tissue was assessed using microarray analysis. Statistical analyses were performed using GraphPad Prism 7 version 7.0 (GraphPad Software, USA). Student’s t test was used to compare between 2 groups. Comparison among more than 2 groups was done using one-way analysis of variance (ANOVA). Data presented as median ± standard deviation (SD). Results Both transplantation of hUC-MSCs and application of EVs resulted in a reduction of peribronchial and perivascular inflammation, alveolar septal thickening associated with mononuclear inflammation, and a decreased number of goblet cells. Moreover, hUC-MSCs and EVs ameliorated the loss of alveolar septa in the emphysematous lung of COPD rats and reduced the levels of NF-κB subunit p65 in the tissue. Subsequent microarray analysis revealed that both hUC-MSCs and EVs significantly regulate multiple pathways known to be associated with COPD. Conclusions In conclusion, we show that hUC-MSC-derived EVs effectively ameliorate by COPD-induced inflammation. Thus, EVs could serve as a new cell-free-based therapy for the treatment of COPD

Microfluidics: reframing biological enquiry

The underlying physical properties of microfluidic tools have led to new biological insights through the development of microsystems that can manipulate, mimic and measure biology at a resolution that has not been possible with macroscale tools. Microsystems readily handle sub-microlitre volumes, precisely route predictable laminar fluid flows and match both perturbations and measurements to the length scales and timescales of biological systems. The advent of fabrication techniques that do not require highly specialized engineering facilities is fuelling the broad dissemination of microfluidic systems and their adaptation to specific biological questions. We describe how our understanding of molecular and cell biology is being and will continue to be advanced by precision microfluidic approaches and posit that microfluidic tools - in conjunction with advanced imaging, bioinformatics and molecular biology approaches - will transform biology into a precision science