Frailty in Older Patients Undergoing Emergency Laparotomy: Results From the UK Observational Emergency Laparotomy and Frailty (ELF) Study.

OBJECTIVE: This study aimed to document the prevalence of frailty in older adults undergoing emergency laparotomy and to explore relationships between frailty and postoperative morbidity and mortality. SUMMARY BACKGROUND DATA: The majority of adults undergoing emergency laparotomy are older adults (≥65 y) that carry the highest mortality. Improved understanding is urgently needed to allow development of targeted interventions. METHODS: An observational multicenter (n=49) UK study was performed (March-June 2017). All older adults undergoing emergency laparotomy were included. Preoperative frailty score was calculated using the progressive Clinical Frailty Score (CFS): 1 (very fit) to 7 (severely frail). Primary outcome measures were the prevalence of frailty (CFS 5-7) and its association to mortality at 90 days postoperative. Secondary outcomes included 30-day mortality and morbidity, length of critical care, and overall hospital stay. RESULTS: A total of 937 older adults underwent emergency laparotomy: frailty was present in 20%. Ninety-day mortality was 19.5%. After age and sex adjustment, the risk of 90-day mortality was directly associated with frailty: CFS 5 adjusted odds ratio (aOR) 3.18 [95% confidence interval (CI), 1.24-8.14] and CFS 6/7 aOR 6·10 (95% CI, 2.26-16.45) compared with CFS 1. Similar associations were found for 30-day mortality. Increasing frailty was also associated with increased risk of complications, length of Intensive Care Unit, and overall hospital stay. CONCLUSIONS: A fifth of older adults undergoing emergency laparotomy are frail. The presence of frailty is associated with greater risks of postoperative mortality and morbidity and is independent of age. Frailty scoring should be integrated into acute surgical assessment practice to aid decision-making and development of novel postoperative strategies.

Is there a standardised consent process within the surgical specialties?

INTRODUCTION: The consent process is central to surgical practice. Subsequent to landmark cases such as Montgomery and Thefaut there is increasing consensus that consent should be a staged process. The aim of our survey was to identify if there was any homogeneity in the practice of surgeons with regards to the consent process in comparison to national guidelines. METHODS: Our survey was distributed to a broad range of surgical specialties via an anonymous Google Forms questionnaire available online. Consultant Surgeons and Specialist registrars across the United Kingdom were then contacted via their relevant surgical societies and professional. Data collection was based on the Montgomery principles: consent location; face to face meetings; information leaflets (including their source); distribution of copies of letters and consent forms; use of percentage risks; use of pre-printed consent forms. RESULTS: The total number of replies was 325. The majority of consent was taken on the day of surgery (166/319; 50.8%). Scheduled meeting for the consent process occurred routinely in only 87 cases (87/319; 27.3%). 103 (103/319; 32.9%) responders indicated the use of pre-printed consent forms. Of which 93 (93/103; 90.3%) were produced locally. Risk percentages were routinely used by 103 responders (103/319; 32.9%) Nearly two-thirds never write specific risk percentages routinely (205/319; 64.3%). Copies of consent forms were routinely given out by 210 responders (210/319; 65.8%). Supporting information was routinely given to patients in 248 cases (248/319; 77.7%). CONCLUSION: Our survey documents significant variation in the practice of consent despite clear guidance on best practice. We believe that most surgeons welcome a more thorough and robust consent process, but hey need the time and infrastructure to be able to do it Introduction.

In vivo single-RNA tracking shows that most tRNA diffuses freely in live bacteria.

Transfer RNA (tRNA) links messenger RNA nucleotide sequence with amino acid sequence during protein synthesis. Despite the importance of tRNA for translation, its subcellular distribution and diffusion properties in live cells are poorly understood. Here, we provide the first direct report on tRNA diffusion localization in live bacteria. We internalized tRNA labeled with organic fluorophores into live bacteria, applied single-molecule fluorescence imaging with single-particle tracking and localized and tracked single tRNA molecules over seconds. We observed two diffusive species: fast (with a diffusion coefficient of ∼8 µm2/s, consistent with free tRNA) and slow (consistent with tRNA bound to larger complexes). Our data indicate that a large fraction of internalized fluorescent tRNA (>70%) appears to diffuse freely in the bacterial cell. We also obtained the subcellular distribution of fast and slow diffusing tRNA molecules in multiple cells by normalizing for cell morphology. While fast diffusing tRNA is not excluded from the bacterial nucleoid, slow diffusing tRNA is localized to the cell periphery (showing a 30% enrichment versus a uniform distribution), similar to non-uniform localizations previously observed for mRNA and ribosomes.

Elongation factor G initiates translocation through a power stroke.

During the translocation step of prokaryotic protein synthesis, elongation factor G (EF-G), a guanosine triphosphatase (GTPase), binds to the ribosomal PRE-translocation (PRE) complex and facilitates movement of transfer RNAs (tRNAs) and messenger RNA (mRNA) by one codon. Energy liberated by EF-G's GTPase activity is necessary for EF-G to catalyze rapid and precise translocation. Whether this energy is used mainly to drive movements of the tRNAs and mRNA or to foster EF-G dissociation from the ribosome after translocation has been a long-lasting debate. Free EF-G, not bound to the ribosome, adopts quite different structures in its GTP and GDP forms. Structures of EF-G on the ribosome have been visualized at various intermediate steps along the translocation pathway, using antibiotics and nonhydolyzable GTP analogs to block translocation and to prolong the dwell time of EF-G on the ribosome. However, the structural dynamics of EF-G bound to the ribosome have not yet been described during normal, uninhibited translocation. Here, we report the rotational motions of EF-G domains during normal translocation detected by single-molecule polarized total internal reflection fluorescence (polTIRF) microscopy. Our study shows that EF-G has a small (∼10°) global rotational motion relative to the ribosome after GTP hydrolysis that exerts a force to unlock the ribosome. This is followed by a larger rotation within domain III of EF-G before its dissociation from the ribosome.

The Fallacy of Choice: the Destructive Effect of School Vouchers on Children With Disabilities.

This Article addresses the impact of school voucher programs on students with disabilities. We show that for children with disabilities, the price of admission into so-called "school choice" programs is so high that it is effectively no real choice at all. School voucher programs require students with disabilities to sign away their robust federal rights and protections in the public school system. Under the Individuals with Disabilities Education Act (IDEA)--the preeminent legislative safeguard for students with disabilities--these rights include the right to a "free and appropriate public education" delivered through an "individualized education plan." By giving up these protections, children with disabilities are left at the mercy of private schools that have no legal obligation to provide them with an appropriate education, and, in the vast majority of cases, are not legally prohibited from discriminating against them on the basis of their disability. We argue that school voucher programs--including a proposed federal voucher program--put the education of students with disabilities back decades, and likely constitute a violation of the Equal Protection Clause of the U.S. Constitution.

Electrophoretic Deformation of Individual Transfer RNA Molecules Reveals Their Identity.

It has been hypothesized that the ribosome gains additional fidelity during protein translation by probing structural differences in tRNA species. We measure the translocation kinetics of different tRNA species through ∼3 nm diameter synthetic nanopores. Each tRNA species varies in the time scale with which it is deformed from equilibrium, as in the translocation step of protein translation. Using machine-learning algorithms, we can differentiate among five tRNA species, analyze the ratios of tRNA binary mixtures, and distinguish tRNA isoacceptors.

Dicodon monitoring of protein synthesis (DiCoMPS) reveals levels of synthesis of a viral protein in single cells.

The current report represents a further advancement of our previously reported technology termed Fluorescent transfer RNA (tRNA) for Translation Monitoring (FtTM), for monitoring of active global protein synthesis sites in single live cells. FtTM measures Förster resonance energy transfer (FRET) signals, generated when fluorescent tRNAs (fl-tRNAs), separately labeled as a FRET pair, occupy adjacent sites on the ribosome. The current technology, termed DiCodon Monitoring of Protein Synthesis (DiCoMPS), was developed for monitoring active synthesis of a specific protein. In DiCoMPS, specific fl-tRNA pair combinations are selected for transfection, based on the degree of enrichment of a dicodon sequence to which they bind in the mRNA of interest, relative to the background transcriptome of the cell in which the assay is performed. In this study, we used cells infected with the Epizootic Hemorrhagic Disease Virus 2-Ibaraki and measured, through DiCoMPS, the synthesis of the viral non-structural protein 3 (NS3), which is enriched in the AUA:AUA dicodon. fl-tRNA(Ile)UAU-generated FRET signals were specifically enhanced in infected cells, increased in the course of infection and were diminished on siRNA-mediated knockdown of NS3. Our results establish an experimental approach for the single-cell measurement of the levels of synthesis of a specific viral protein.

Monitoring collagen synthesis in fibroblasts using fluorescently labeled tRNA pairs.

There is a critical need for techniques that directly monitor protein synthesis within cells isolated from normal and diseased tissue. Fibrotic disease, for which there is no drug treatment, is characterized by the overexpression of collagens. Here, we use a bioinformatics approach to identify a pair of glycine and proline isoacceptor tRNAs as being specific for the decoding of collagen mRNAs, leading to development of a FRET-based approach, dicodon monitoring of protein synthesis (DiCoMPS), that directly monitors the synthesis of collagen. DiCoMPS aimed at detecting collagen synthesis will be helpful in identifying novel anti-fibrotic compounds in cells derived from patients with fibrosis of any etiology, and, suitably adapted, should be widely applicable in monitoring the synthesis of other proteins in cells.

Influence of frailty in older patients undergoing emergency laparotomy: a UK-based observational study.

INTRODUCTION: The National Emergency Laparotomy Audit (NELA) has reported that older patients (≥65 years) form a large percentage of emergency high-risk cases with increased postoperative morbidity and mortality. With the population continuing to age rapidly, it is clear that a greater understanding of the factors affecting surgical outcomes in older patients is required. Frailty is a relatively new concept taking into account a variety of factors that increase an individual's vulnerability to increased dependency and death. Research has suggested that high frailty scores increase postoperative complications, length of stay and mortality but the majority of these studies have been carried out on elective patients. Knowledge of how frailty affects patients in an emergency setting would aid clinicians' and patients' decision-making process. METHODS AND ANALYSIS: This multicentre study will include consecutive adult patients aged 65 years and over undergoing emergency laparotomies over a 3-month period at 52 National Health Service hospitals across the UK. The primary outcome will be 90-day mortality. Secondary outcomes will include length of hospital stay, 30-day complications, change in level of independence and 30-day readmission. This study has been powered to detect a 10% change in mortality associated with frailty (n=500 patients). ETHICS AND DISSEMINATION: This study has been approved by the National Health Service Research Ethics Committee. It has been registered centrally with HRA for English sites, NRSPCC for Scottish sites and Health and Care Research Permissions Service for sites in Wales.Dissemination will be via international and national surgical and geriatric conferences. In addition, manuscripts will be prepared following the close of the project. TRIAL REGISTRATION NUMBER: This study is also registered online at www.clinicaltrials.gov (registration number NCT02952430).

A simple case of gallstone ileus?

A 68-year-old gentleman presented with abdominal distension and faeculent vomiting. He had a background of cerebral palsy with learning difficulties making history taking problematic. A CT scan suggested small bowel obstruction secondary to gallstone ileus. The most likely differential diagnosis was an inguinal hernia which was noted adjacent to the transition point. Laparotomy revealed grossly dilated small bowel with a 3-cm intraluminal gallstone. The gallstone was freely mobile within the lumen on the ileum and thus could not be causing obstruction. A caecal mass was also found, which was determined to be the cause of the obstruction. Limited ileocaecectomy was performed, which revealed a Duke's A adenocarcinoma. Gallstone ileus and caecal tumour can commonly be confused prior to surgery. There are however no previous reports of concurrent gallstone ileus and caecal tumour. Communication issues with the patient are likely to have contributed to the difficulty in diagnosis.

Dynamics of translation by single ribosomes through mRNA secondary structures.

During protein synthesis, the ribosome translates nucleotide triplets in single-stranded mRNA into polypeptide sequences. Strong downstream mRNA secondary structures, which must be unfolded for translation, can slow or even halt protein synthesis. Here we used single-molecule fluorescence resonance energy transfer to determine reaction rates for specific steps within the elongation cycle as the Escherichia coli ribosome encounters stem-loop or pseudoknot mRNA secondary structures. Downstream stem-loops containing 100% GC base pairs decrease the rates of both tRNA translocation within the ribosome and deacylated tRNA dissociation from the ribosomal exit site (E site). Downstream stem-loops or pseudoknots containing both GC and AU pairs also decrease the rate of tRNA dissociation, but they have little effect on tRNA translocation rate. Thus, somewhat unexpectedly, unfolding of mRNA secondary structures is more closely coupled to E-site tRNA dissociation than to tRNA translocation.

FRET-based identification of mRNAs undergoing translation.

We present proof-of-concept in vitro results demonstrating the feasibility of using single molecule fluorescence resonance energy transfer (smFRET) measurements to distinguish, in real time, between individual ribosomes programmed with several different, short mRNAs. For these measurements we use either the FRET signal generated between two tRNAs labeled with different fluorophores bound simultaneously in adjacent sites to the ribosome (tRNA-tRNA FRET) or the FRET signal generated between a labeled tRNA bound to the ribosome and a fluorescent derivative of ribosomal protein L1 (L1-tRNA FRET). With either technique, criteria were developed to identify the mRNAs, taking into account the relative activity of the mRNAs. These criteria enabled identification of the mRNA being translated by a given ribosome to within 95% confidence intervals based on the number of identified FRET traces. To upgrade the approach for natural mRNAs or more complex mixtures, the stoichiometry of labeling should be enhanced and photobleaching reduced. The potential for porting these methods into living cells is discussed.

The involvement of metal-to-CO charge transfer and ligand-field excited states in the spectroscopy and photochemistry of mixed-ligand metal carbonyls. A theoretical and spectroscopic study of [W(CO)(4)(1,2-ethylenediamine)] and [W(CO)(4)(N,N'-bis-alkyl-1,4-diazabutadiene)].

A new interpretation of the electronic spectroscopy, photochemistry, and photophysics of group 6 metal cis-tetracarbonyls [M(CO)(4)L(2)] is proposed, that is based on an interplay between M --> L and M --> CO MLCT excited states. TD-DFT and resonance Raman spectroscopy show that the lowest allowed electronic transition of [W(CO)(4)(en)] (en = 1,2-ethylenediamine) has a W(CO(eq))(2) --> CO(ax) charge-transfer character, whereby the electron density is transferred from the equatorial W(CO(eq))(2) moiety to pi orbitals of the axial CO ligands, with a net decrease of electron density on the W atom. The lowest, emissive excited state of [W(CO)(4)(en)] was identified as a spin-triplet W(CO(eq))(2) --> CO(ax) CT excited state both computationally and by picosecond time-resolved IR spectroscopy. This state undergoes 1.5 ps vibrational relaxation/solvation and decays to the ground state with a approximately 160 ps lifetime. The nu(CO) wavenumbers and IR intensity pattern calculated by DFT for the triplet W(CO(eq))(2) --> CO(ax) CT excited state match well the experimental time-resolved spectrum. For [W(CO)(4)(R-DAB)] (R-DAB = N,N'-bis-alkyl-1,4-diazabutadiene), the W(CO(eq))(2) --> CO(ax) CT transition follows in energy the W --> DAB MLCT transition, and the emissive W(CO(eq))(2) --> CO(ax) CT triplet state occurs just above the manifold of triplet W --> DAB MLCT states. No LF electronic transitions were calculated to occur in a relevant energetic range for either complex. Molecular orbitals of both complexes are highly delocalized. The 5d(W) character is distributed over many molecular orbitals, while neither of them contains a predominant metal-ligand sigma 5d(W) component, contrary to predictions of the traditional ligand-field approach. The important spectroscopic, photochemical, and photophysical roles of M(CO(eq))(2) --> CO(ax) CT excited states and the limited validity of ligand field arguments can be generalized to other mixed-ligand carbonyl complexes.

Direct observation of competitive ultrafast CO dissociation and relaxation of an MLCT excited state: picosecond time-resolved infrared spectroscopic study of [Cr(CO)(4)(2,2'-bipyridine)].

Early excited-state dynamics of [Cr(CO)(4)(bpy)] were studied in a CH(2)Cl(2) solution by picosecond time-resolved IR spectroscopy, which made it possible to characterize structurally the individual species involved and to follow separately the temporal evolution of the IR bands due to the bleached ground-state absorption, the fac-[Cr(CO)(3)(Sol)(bpy)] photoproduct, and two (3)MLCT states. It was found that the fac-[Cr(CO)(3)(Sol)(bpy)] photoproduct is formed alongside population of two (3)MLCT states during the first picosecond after excitation at 400 or 500 nm by a branched evolution of the optically populated excited state. Vibrationally relaxed (3)MLCT excited states are unreactive, decaying directly to the ground state on a picosecond time scale. The photoproduct is long-lived, persistent into the nanosecond time domain. Changing the excitation wavelength from 400 to 500 nm strongly increases the extent of the bleach recovery and decreases the yield of the photoproduct formation relative to the initial yield of the population of the unreactive (3)MLCT states. The photochemical quantum yield of CO dissociation also decreases with increasing excitation wavelength (Víchová, J.; Hartl, F.; Vlcek, A., Jr. J. Am. Chem. Soc. 1992, 114, 10903). These observations demonstrate the relationship between the early dynamics of optically populated excited states and the overall outcome of a photochemical reaction and identify the limiting role of the branching of the initial excited-state evolution between reactive and relaxation pathways as a more general principle of organometallic photochemistry.