Comparison of antiemetic activity of palonosetron with granisetron in postoperative nausea and vomiting after laparoscopic gynaecological surgeries

Background: Granisetron is currently one of the commonly used drugs for prevention of postoperative nausea and vomiting (PONV) which is one of the most common distressing complications of laparoscopic surgeries and anesthesia. Palonosetron has emerged as alternative for PONV in adults. Thus, the study was aimed to conduct a comparison of the efficacy and adverse effects of granisetron with palonosetron to prevent PONV in patients undergoing general anaesthesia for elective laparoscopic gynaecological surgeries.Methods: This was a prospective, randomized, double blinded and a comparative study and was performed in Lokmanya Municipal Medical College and general Hospital, Sion, Mumbai, India on 60 patients undergoing elective laparoscopic gynaecologic surgeries, requiring general anaesthesia with endotracheal intubation.Results: Both granisetron 2.5 mg and palonosetron 75 µg are comparable in all respects. They have almost similar incidences in nausea, retching, vomiting and administration of rescue antiemetic at 0-2 hrs, 3 hrs, 12 hrs and 24 hrs postoperatively. The values were not significantly different. The adverse effects seen with both the drugs were not statistically significant.Conclusions: From the study this can be concluded that both the drugs are effective as prophylactic antiemetic in preventing PONV in laparoscopic gynaecological surgeries which are supposed to be highly emetogenic surgery

The C-terminal tail of the yeast mitochondrial transcription factor Mtf1 coordinates template strand alignment, DNA scrunching and timely transition into elongation

Mitochondrial RNA polymerases depend on initiation factors, such as TFB2M in humans and Mtf1 in yeast Saccharomyces cerevisiae, for promoterspecific transcription. These factors drive the melting of promoter DNA, but how they support RNA priming and growth was not understood. We show that the flexible C-terminal tails of Mtf1 and TFB2M play a crucial role in RNA priming by aiding template strand alignment in the active site for high-affinity binding of the initiating nucleotides. Using single-molecule fluorescence approaches, we show that the Mtf1 C-tail promotes RNA growth during initiation by stabilizing the scrunched DNA conformation. Additionally, due to its location in the path of the nascent RNA, the C-tail of Mtf1 serves as a sensor of the RNA- DNA hybrid length. Initially, steric clashes of the Mtf1 C-tail with short RNA-DNA hybrids cause abortive synthesis but clashes with longer RNA-DNA trigger conformational changes for the timely release of the promoter DNA to commence the transition into elongation. The remarkable similarities in the functions of the C-tail and sigma 3.2 finger of the bacterial factor suggest mechanistic convergence of a flexible element in the transcription initiation factor that engages the DNA template for RNA priming and growth and disengages when needed to generate the elongation complex

Kinetics of transcription initiation at lacP1: multiple roles of cyclic amp receptor protein

The cyclic AMP receptor protein (CRP) acts as a transcription activator at many promoters of Escherichia coli. We have examined the kinetics of open complex formation at the lacP1 promoter using tryptophan fluorescence of RNA polymerase and DNA fragments with 2-aminopurine substituted at specific positions. Apart from the closed complex formation and promoter clearance, we were able to detect three steps. The first step after the closed complex formation leads to a rapid increase of 2-aminopurine fluorescence. This was followed by another rapid step in which quenching of tryptophan fluorescence of RNA polymerase was observed. The slowest step detected by 2-aminopurine fluorescence increase is assigned to the final open complex formation. We have found that CRP not only enhances RNA polymerase binding at the promoter, but also enhances the slowest isomerization step by about 2-fold. Furthermore, potassium permanganate probing shows that the conformation of the open complex in the presence of CRP appears qualitatively and quantitatively different from that in the absence of CRP, suggesting that contact with RNA polymerase is maintained throughout the transcription initiation

Highly efficient 5\u27 capping of mitochondrial RNA with NAD+ and NADH by yeast and human mitochondrial RNA polymerase

Bacterial and eukaryotic nuclear RNA polymerases (RNAPs) cap RNA with the oxidized and reduced forms of the metabolic effector nicotinamide adenine dinucleotide, NAD+ and NADH, using NAD+ and NADH as non-canonical initiating nucleotides for transcription initiation. Here, we show that mitochondrial RNAPs (mtRNAPs) cap RNA with NAD+ and NADH, and do so more efficiently than nuclear RNAPs. Direct quantitation of NAD+- and NADH-capped RNA demonstrates remarkably high levels of capping in vivo: up to ~60% NAD+ and NADH capping of yeast mitochondrial transcripts, and up to ~15% NAD+ capping of human mitochondrial transcripts. The capping efficiency is determined by promoter sequence at, and upstream of, the transcription start site and, in yeast and human cells, by intracellular NAD+ and NADH levels. Our findings indicate mtRNAPs serve as both sensors and actuators in coupling cellular metabolism to mitochondrial transcriptional outputs, sensing NAD+ and NADH levels and adjusting transcriptional outputs accordingly. © 2018, Bird et al

The dynamic landscape of transcription initiation in yeast mitochondria

Controlling efficiency and fidelity in the early stage of mitochondrial DNA transcription is crucial for regulating cellular energy metabolism. Conformational transitions of the transcription initiation complex must be central for such control, but how the conformational dynamics progress throughout transcription initiation remains unknown. Here, we use single-molecule fluorescence resonance energy transfer techniques to examine the conformational dynamics of the transcriptional system of yeast mitochondria with single-base resolution. We show that the yeast mitochondrial transcriptional complex dynamically transitions among closed, open, and scrunched states throughout the initiation stage. Then abruptly at position +8, the dynamic states of initiation make a sharp irreversible transition to an unbent conformation with associated promoter release. Remarkably, stalled initiation complexes remain in dynamic scrunching and unscrunching states without dissociating the RNA transcript, implying the existence of backtracking transitions with possible regulatory roles. The dynamic landscape of transcription initiation suggests a kinetically driven regulation of mitochondrial transcription. Conformational dynamics during the early stage of transcription is crucial to understanding the regulation of transcription efficiency and fidelity. Here the authors, by single-molecule fluorescence resonance energy transfer approaches, examine the conformational dynamics of the two-component transcription system of yeast mitochondria with single-base resolution

British Lung Foundation/United Kingdom primary immunodeficiency network consensus statement on the definition, diagnosis, and management of granulomatous-lymphocytic interstitial lung disease in common variable immunodeficiency disorders

A proportion of people living with common variable immunodeficiency disorders develop granulomatous-lymphocytic interstitial lung disease (GLILD). We aimed to develop a consensus statement on the definition, diagnosis, and management of GLILD. All UK specialist centers were contacted and relevant physicians were invited to take part in a 3-round online Delphi process. Responses were graded as Strongly Agree, Tend to Agree, Neither Agree nor Disagree, Tend to Disagree, and Strongly Disagree, scored +1, +0.5, 0, −0.5, and −1, respectively. Agreement was defined as greater than or equal to 80% consensus. Scores are reported as mean ± SD. There was 100% agreement (score, 0.92 ± 0.19) for the following definition: “GLILD is a distinct clinico-radio-pathological ILD occurring in patients with [common variable immunodeficiency disorders], associated with a lymphocytic infiltrate and/or granuloma in the lung, and in whom other conditions have been considered and where possible excluded.” There was consensus that the workup of suspected GLILD requires chest computed tomography (CT) (0.98 ± 0.01), lung function tests (eg, gas transfer, 0.94 ± 0.17), bronchoscopy to exclude infection (0.63 ± 0.50), and lung biopsy (0.58 ± 0.40). There was no consensus on whether expectant management following optimization of immunoglobulin therapy was acceptable: 67% agreed, 25% disagreed, score 0.38 ± 0.59; 90% agreed that when treatment was required, first-line treatment should be with corticosteroids alone (score, 0.55 ± 0.51)

Kinetic Pathway of Pyrophosphorolysis by a Retrotransposon Reverse Transcriptase

DNA and RNA polymerases use a common phosphoryl transfer mechanism for base addition that requires two or three acidic amino acid residues at their active sites. We previously showed, for the reverse transcriptase (RT) encoded by the yeast retrotransposon Ty1, that one of the three conserved active site aspartates (D211) can be substituted by asparagine and still retain in vitro polymerase activity, although in vivo transposition is lost. Transposition is partially restored by second site suppressor mutations in the RNAse H domain. The novel properties of this amino acid substitution led us to express the WT and D211N mutant enzymes, and study their pre-steady state kinetic parameters. We found that the kpol was reduced by a factor of 223 in the mutant, although the Kd for nucleotide binding was unaltered. Further, the mutant enzyme had a marked preference for Mn2+ over Mg2+. To better understand the functions of this residue within the Ty1 RT active site, we have now examined the in vitro properties of WT and D211N mutant Ty1 RTs in carrying out pyrophosphorolysis, the reverse reaction to polymerization, where pyrophosphate is the substrate and dNTPs are the product. We find that pyrophosphorolysis is efficient only when the base-paired primer template region is >14 bases, and that activity increases when the primer end is blunt-ended or recessed by only a few bases. Using pre-steady state kinetic analysis, we find that the rate of pyrophosphorolysis (kpyro) in the D211N mutant is nearly 320 fold lower than the WT enzyme, and that the mutant enzyme has an ∼170 fold lower apparent Kd for pyrophosphate. These findings indicate that subtle substrate differences can strongly affect the enzyme's ability to properly position the primer-end to carry out pyrophosphorolysis. Further the kinetic data suggests that the D211 residue has a role in pyrophosphate binding and release, which could affect polymerase translocation, and help explain the D211N mutant's transposition defect

Opening-closing dynamics of the mitochondrial transcription pre-initiation complex

Promoter recognition and local melting of DNA are key steps of transcription initiation catalyzed by RNA polymerase and initiation factors. From single molecule fluorescence resonance energy transfer studies of the yeast (Saccharomyces cerevisiae) mitochondrial RNA polymerase Rpo41 and its transcription factor Mtf1, we show that the pre-initiation complex is highly dynamic and undergoes repetitive opening-closing transitions that are modulated by Mtf1 and ATP. We found that Rpo41 alone has the intrinsic ability to bend the promoter but only very briefly. Mtf1 enhances bending/opening transition and suppresses closing transition, indicating its dual roles of nucleating promoter opening and stabilizing the open state. The cognate initiating ATP prolongs the lifetime of the open state, plausibly explaining the 'ATP sensing mechanism' suggested for the system. We discovered short-lived opening trials upon initial binding of Rpo41-Mtf1 before the establishment of the opening/closing equilibrium, which may aid in promoter selection before the formation of stable pre-initiation complex. The dynamics of open complex formation provides unique insights into the interplay between RNA polymerase and transcription factors in regulating initiation.open4

Collaborative community based care for people and their families living with schizophrenia in India: protocol for a randomised controlled trial

BACKGROUND: There is a large treatment gap with few community services for people with schizophrenia in low income countries largely due to the shortage of specialist mental healthcare human resources. Community based rehabilitation (CBR), involving lay health workers, has been shown to be feasible, acceptable and more effective than routine care for people with schizophrenia in observational studies. The aim of this study is to evaluate whether a lay health worker led, Collaborative Community Based Care (CCBC) intervention, combined with usual Facility Based Care (FBC), is superior to FBC alone in improving outcomes for people with schizophrenia and their caregivers in India. METHODS/DESIGN: This trial is a multi-site, parallel group randomised controlled trial design in India.The trial will be conducted concurrently at three sites in India where persons with schizophrenia will be screened for eligibility and recruited after providing informed consent. Trial participants will be randomly allocated in a 2:1 ratio to the CCBC+FBC and FBC arms respectively using an allocation sequence pre-prepared through the use of permuted blocks, stratified within site. The structured CCBC intervention will be delivered by trained lay community health workers (CHWs) working together with the treating Psychiatrist. We aim to recruit 282 persons with schizophrenia. The primary outcomes are reduction in severity of symptoms of schizophrenia and disability at 12 months. The study will be conducted according to good ethical practice, data analysis and reporting guidelines. DISCUSSION: If the additional CCBC intervention delivered by front line CHWs is demonstrated to be effective and cost-effective in comparison to usually available care, this intervention can be scaled up to expand coverage and improve outcomes for persons with schizophrenia and their caregivers in low income countries. TRIAL REGISTRATION: The trial is registered with the International Society for the Registration of Clinical Trials and the allocated unique ID number is ISRCTN 56877013

Alzheimer's “Prevention” vs. “Risk Reduction”: Transcending Semantics for Clinical Practice

The terms “prevention” and “risk reduction” are often used interchangeably in medicine. There is considerable debate, however, over the use of these terms in describing interventions that aim to preserve cognitive health and/or delay disease progression of Alzheimer's disease (AD) for patients seeking clinical care. Furthermore, it is important to distinguish between Alzheimer's disease prevention and Alzheimer's dementia prevention when using these terms. While prior studies have codified research-based criteria for the progressive stages of AD, there are no clear clinical consensus criteria to guide the use of these terms for physicians in practice. A clear understanding of the implications of each term will help guide clinical practice and clinical research. The authors explore the semantics and appropriate use of the terms “prevention” and “risk reduction” as they relate to AD in clinical practice