Postoperative mortality and complications in patients with and without pre-operative SARS-CoV-2 infection: a service evaluation of 24 million linked records using OpenSAFELY.

Surgical decision-making after SARS-CoV-2 infection is influenced by the presence of comorbidity, infection severity and whether the surgical problem is time-sensitive. Contemporary surgical policy to delay surgery is informed by highly heterogeneous country-specific guidance. We evaluated surgical provision in England during the COVID-19 pandemic to assess real-world practice and whether deferral remains necessary. Using the OpenSAFELY platform, we adapted the COVIDSurg protocol for a service evaluation of surgical procedures that took place within the English NHS from 17 March 2018 to 17 March 2022. We assessed whether hospitals adhered to guidance not to operate on patients within 7 weeks of an indication of SARS-CoV-2 infection. Additional outcomes were postoperative all-cause mortality (30 days, 6 months) and complications (pulmonary, cardiac, cerebrovascular). The exposure was the interval between the most recent indication of SARS-CoV-2 infection and subsequent surgery. In any 6-month window, < 3% of surgical procedures were conducted within 7 weeks of an indication of SARS-CoV-2 infection. Mortality for surgery conducted within 2 weeks of a positive test in the era since widespread SARS-CoV-2 vaccine availability was 1.1%, declining to 0.3% by 4 weeks. Compared with the COVIDSurg study cohort, outcomes for patients in the English NHS cohort were better during the COVIDSurg data collection period and the pandemic era before vaccines became available. Clinicians within the English NHS followed national guidance by operating on very few patients within 7 weeks of a positive indication of SARS-CoV-2 infection. In England, surgical patients' overall risk following an indication of SARS-CoV-2 infection is lower than previously thought.

"Hyperglycemia aversiveness": Investigating an overlooked problem among adults with type 1 diabetes.

AIMS: To investigate the problem of adults with type 1 diabetes (T1D) who purposefully keep their glucose levels low, and to explore contributors to, and possible impact of, this potentially dangerous phenomenon. METHODS: We developed three self-report items as a means to identify individuals who endorse a consistent preference for hypoglycemia over hyperglycemia ("Hyperglycemia Aversives"). In a large T1D survey (n = 219), validated measures of well-being, emotional distress and hypoglycemic awareness, and glycemic metrics derived from the past 14-day period, were used to examine whether Hyperglycemia Aversives could be characterized as a distinct group. RESULTS: Hyperglycemia Aversives comprised 16.4% of the sample. This unique group demonstrated significantly higher mean %TIR (71.6% vs. 63.6%) and %TBR (5.1% vs. 2.2%), lower mean %TAR > 250 mg/dL (6.0% vs. 10.1%), and higher rates of impaired hypoglycemic awareness and recurrent severe hypoglycemia episodes than the remaining study sample ("Non-Aversives") (all ps < 0.01). The two groups did not demonstrate significant differences on psychosocial outcomes. CONCLUSIONS: We identified a group of T1D adults reporting a consistent preference for hypoglycemia over hyperglycemia. These individuals achieve significantly greater %TIR and less %TAR, but at the cost of greater %TBR and more frequent severe hypoglycemia episodes.

Topoisomerase Inhibitors Addressing Fluoroquinolone Resistance in Gram-Negative Bacteria.

Since their discovery over 5 decades ago, quinolone antibiotics have found enormous success as broad spectrum agents that exert their activity through dual inhibition of bacterial DNA gyrase and topoisomerase IV. Increasing rates of resistance, driven largely by target-based mutations in the GyrA/ParC quinolone resistance determining region, have eroded the utility and threaten the future use of this vital class of antibiotics. Herein we describe the discovery and optimization of a series of 4-(aminomethyl)quinolin-2(1H)-ones, exemplified by 34, that inhibit bacterial DNA gyrase and topoisomerase IV and display potent activity against ciprofloxacin-resistant Gram-negative pathogens. X-ray crystallography reveals that 34 occupies the classical quinolone binding site in the topoisomerase IV-DNA cleavage complex but does not form significant contacts with residues in the quinolone resistance determining region.

Trapping of the transport-segment DNA by the ATPase domains of a type II topoisomerase.

Type II topoisomerases alter DNA topology to control DNA supercoiling and chromosome segregation and are targets of clinically important anti-infective and anticancer therapeutics. They act as ATP-operated clamps to trap a DNA helix and transport it through a transient break in a second DNA. Here, we present the first X-ray crystal structure solved at 2.83 Å of a closed clamp complete with trapped T-segment DNA obtained by co-crystallizing the ATPase domain of S. pneumoniae topoisomerase IV with a nonhydrolyzable ATP analogue and 14-mer duplex DNA. The ATPase dimer forms a 22 Å protein hole occupied by the kinked DNA bound asymmetrically through positively charged residues lining the hole, and whose mutagenesis impacts the DNA decatenation, DNA relaxation and DNA-dependent ATPase activities of topo IV. These results and a side-bound DNA-ParE structure help explain how the T-segment DNA is captured and transported by a type II topoisomerase, and reveal a new enzyme-DNA interface for drug discovery.

von Frey anesthesiometry to assess sensory impairment after acute spinal cord injury caused by thoracolumbar intervertebral disc extrusion in dogs.

Sensory threshold (ST) was measured using an electric von Frey anesthesiometer (VFA) in all limbs of 20 normal dogs and 29 dogs with acute thoracolumbar spinal cord injury (SCI) caused by spontaneous intervertebral disc extrusion. ST values were measured at three separate time points in normal dogs and on days 3, 10 and 30 following decompressive surgery in dogs with SCI. ST values were compared between groups and correlated with locomotor recovery in SCI-affected dogs. ST values were significantly higher (consistent with hypoalgesia) in the pelvic limbs of SCI-affected dogs at day 3, day 10 and day 30 when compared to normal dogs (P <0.05), while no significant difference in thoracic limb ST values was observed between groups. A progressive decrease in pelvic limb ST values occurred in SCI-affected dogs over time, consistent with improvement toward normal sensation or development of allodynia. This finding correlated inversely with locomotor score at 3 and 10 days after surgery. A significant decline in ST values across testing sessions was observed for all limbs of normal and SCI-affected dogs and may be related to patient acclimation, operator training effect, or effect of analgesic medications. This study supports the feasibility of VFA to assess differences in ST between normal and SCI-affected dogs. However, future studies must focus on techniques to minimize or compensate for clinical, environmental and behavioral factors which may impact ST values in the clinical setting.

A simplified method of walking track analysis to assess short-term locomotor recovery after acute spinal cord injury caused by thoracolumbar intervertebral disc extrusion in dogs.

The purpose of this study was to evaluate a simplified method of walking track analysis to assess treatment outcome in canine spinal cord injury. Measurements of stride length (SL) and base of support (BS) were made using a 'finger painting' technique for footprint analysis in all limbs of 20 normal dogs and 27 dogs with 28 episodes of acute thoracolumbar spinal cord injury (SCI) caused by spontaneous intervertebral disc extrusion. Measurements were determined at three separate time points in normal dogs and on days 3, 10 and 30 following decompressive surgery in dogs with SCI. Values for SL, BS and coefficient of variance (COV) for each parameter were compared between groups at each time point. Mean SL was significantly shorter in all four limbs of SCI-affected dogs at days 3, 10, and 30 compared to normal dogs. SL gradually increased toward normal in the 30 days following surgery. As measured by this technique, the COV-SL was significantly higher in SCI-affected dogs than normal dogs in both thoracic limbs (TL) and pelvic limbs (PL) only at day 3 after surgery. BS-TL was significantly wider in SCI-affected dogs at days 3, 10 and 30 following surgery compared to normal dogs. These findings support the use of footprint parameters to compare locomotor differences between normal and SCI-affected dogs, and to assess recovery from SCI. Additionally, our results underscore important changes in TL locomotion in thoracolumbar SCI-affected dogs.

Peripheral T-cell lymphoma mimicking 5-aminosalicylate hypersensitivity in ulcerative colitis.

5-aminosalicylates (5-ASA) remain an important strategy in the induction and maintenance of remission of inflammatory bowel diseases especially in ulcerative colitis. The prototypical drug of this class, sulfasalazine is generally well tolerated with severe hypersensitivity reactions and hepatotoxicity also described within the literature. When approaching a patient with an adverse reaction to 5-ASA, it can be difficult to differentiate clinically between a sulfa allergy versus a 5-ASA allergy versus a malignancy. We report on a case with initial signs and symptoms suggestive of a sulfa/5-ASA allergy that was subsequently found to be malignant in nature.

Structure of an 'open' clamp type II topoisomerase-DNA complex provides a mechanism for DNA capture and transport.

Type II topoisomerases regulate DNA supercoiling and chromosome segregation. They act as ATP-operated clamps that capture a DNA duplex and pass it through a transient DNA break in a second DNA segment via the sequential opening and closure of ATPase-, G-DNA- and C-gates. Here, we present the first 'open clamp' structures of a 3-gate topoisomerase II-DNA complex, the seminal complex engaged in DNA recognition and capture. A high-resolution structure was solved for a (full-length ParE-ParC55)2 dimer of Streptococcus pneumoniae topoisomerase IV bound to two DNA molecules: a closed DNA gate in a B-A-B form double-helical conformation and a second B-form duplex associated with closed C-gate helices at a novel site neighbouring the catalytically important ß-pinwheel DNA-binding domain. The protein N gate is present in an 'arms-wide-open' state with the undimerized N-terminal ParE ATPase domains connected to TOPRIM domains via a flexible joint and folded back allowing ready access both for gate and transported DNA segments and cleavage-stabilizing antibacterial drugs. The structure shows the molecular conformations of all three gates at 3.7 Å, the highest resolution achieved for the full complex to date, and illuminates the mechanism of DNA capture and transport by a type II topoisomerase.

Structural basis of gate-DNA breakage and resealing by type II topoisomerases.

Type II DNA topoisomerases are ubiquitous enzymes with essential functions in DNA replication, recombination and transcription. They change DNA topology by forming a transient covalent cleavage complex with a gate-DNA duplex that allows transport of a second duplex though the gate. Despite its biological importance and targeting by anticancer and antibacterial drugs, cleavage complex formation and reversal is not understood for any type II enzyme. To address the mechanism, we have used X-ray crystallography to study sequential states in the formation and reversal of a DNA cleavage complex by topoisomerase IV from Streptococcus pneumoniae, the bacterial type II enzyme involved in chromosome segregation. A high resolution structure of the complex captured by a novel antibacterial dione reveals two drug molecules intercalated at a cleaved B-form DNA gate and anchored by drug-specific protein contacts. Dione release generated drug-free cleaved and resealed DNA complexes in which the DNA gate instead adopts an unusual A/B-form helical conformation with a Mg(2+) ion repositioned to coordinate each scissile phosphodiester group and promote reversible cleavage by active-site tyrosines. These structures, the first for putative reaction intermediates of a type II topoisomerase, suggest how a type II enzyme reseals DNA during its normal reaction cycle and illuminate aspects of drug arrest important for the development of new topoisomerase-targeting therapeutics.

Structural insight into the quinolone-DNA cleavage complex of type IIA topoisomerases.

Type II topoisomerases alter DNA topology by forming a covalent DNA-cleavage complex that allows DNA transport through a double-stranded DNA break. We present the structures of cleavage complexes formed by the Streptococcus pneumoniae ParC breakage-reunion and ParE TOPRIM domains of topoisomerase IV stabilized by moxifloxacin and clinafloxacin, two antipneumococcal fluoroquinolones. These structures reveal two drug molecules intercalated at the highly bent DNA gate and help explain antibacterial quinolone action and resistance.

A cluster randomized controlled trial of cognitive behaviour therapy for common mental disorders in patients with advanced cancer.

BACKGROUND: Cognitive behaviour therapy (CBT) has been shown to reduce psychological morbidity in people with cancer, but no randomized controlled trial (RCT) exists in palliative care. We aimed to determine whether home care nurses could be taught to deliver basic cognitive behavioural techniques and so reduce symptoms of anxiety and depression. METHOD: Clinical nurse specialists (CNSs) at St Christopher's Hospice were randomly allocated to receive training in CBT or continue their usual practice. At the end of the trial, nurses were rated on the Cognitive Therapy First Aid Rating Scale (CTFARS) for CBT competence. Home care patients who scored as possible cases on the Hospital Anxiety and Depression Scale (HADS) entered the trial. Participants received home care nursing visits. Assessments were carried out at baseline, 6, 10 and 16 weeks. RESULTS: Eight nurses received CBT training and seven continued practice as usual. The mean CTFARS scores were 35.9 for the CBT nurses and 19.0 for the controls (p=0.02). A total of 328 patients (54%) were possible cases and 80 entered the trial; most of those excluded were too ill to participate. There was an interaction between group and time: individuals receiving CBT had lower anxiety scores over time [coefficient -0.20, 95% confidence interval (CI) -0.35 to -0.05, p=0.01]. No effect of the training was found for depression. CONCLUSIONS: It is possible to conduct a randomized trial of psychological interventions in palliative care but there is considerable attrition from physical morbidity and mortality. Nurses can learn to integrate basic CBT methods into their clinical practice. This training may be associated with better outcomes for symptoms of anxiety.

Overlapping DSPP mutations cause dentin dysplasia and dentinogenesis imperfecta.

Dentinogenesis imperfecta (DGI) and dentin dysplasia (DD) are allelic disorders due to mutations in DSPP. Typically, the phenotype breeds true within a family. Recently, two reports showed that 3 different net -1 bp frameshift mutations early in DSPP's repeat domain caused DD, whereas 6 more 3' frameshift mutations were associated with DGI. Here we identify a DD kindred with a novel -1 bp frameshift (c.3141delC) that falls within the portion of the DSPP repeat domain previously associated solely with the DGI phenotype. This new frameshift mutation shows that overlapping DSPP mutations can give rise to either DGI or DD phenotypes. Furthermore, the consistent kindred presentation of the DD or DGI phenotype appears to be dependent on an as-yet-undescribed genetic modifier closely linked to DSPP.

The difficult case of crystallization and structure solution for the ParC55 breakage-reunion domain of topoisomerase IV from Streptococcus pneumoniae.

BACKGROUND: Streptococcus pneumoniae is the major cause of community-acquired pneumonia and is also associated with bronchitis, meningitis, otitis and sinusitis. The emergence and increasing prevalence of resistance to penicillin and other antibiotics has led to interest in other anti-pneumonococcal drugs such as quinolones that target the enzymes DNA gyrase and topoisomerase IV. During crystallization and in the avenues to finding a method to determine phases for the structure of the ParC55 breakage-reunion domain of topoisomerase IV from Streptococcus pneumoniae, obstacles were faced at each stage of the process. These problems included: majority of the crystals being twinned, either non-diffracting or exhibiting a high mosaic spread. The crystals, which were grown under conditions that favoured diffraction, were difficult to flash-freeze without loosing diffraction. The initial structure solution by molecular replacement failed and the approach proved to be unviable due to the complexity of the problem. In the end the successful structure solution required an in-depth data analysis and a very detailed molecular replacement search. METHODOLOGY/PRINCIPAL FINDINGS: Crystal anti-twinning agents have been tested and two different methods of flash freezing have been compared. The fragility of the crystals did not allow the usual method of transferring the crystals into the heavy atom solution. Consequently, it was necessary to co-crystallize in the presence of the heavy atom compound. The multiple isomorphous replacement approach was unsuccessful because the 7 cysteine mutants which were engineered could not be successfully derivatized. Ultimately, molecular replacement was used to solve the structure by sorting through a large number of solutions in space group P1 using CNS. CONCLUSIONS/SIGNIFICANCE: The main objective of this paper is to describe the obstacles which were faced and overcome in order to acquire data sets on such difficult crystals and determine phases for successful structure solution.

Clerocidin selectively modifies the gyrase-DNA gate to induce irreversible and reversible DNA damage.

Clerocidin (CL), a microbial diterpenoid, reacts with DNA via its epoxide group and stimulates DNA cleavage by type II DNA topoisomerases. The molecular basis of CL action is poorly understood. We establish by genetic means that CL targets DNA gyrase in the gram-positive bacterium Streptococcus pneumoniae, and promotes gyrase-dependent single- and double-stranded DNA cleavage in vitro. CL-stimulated DNA breakage exhibited a strong preference for guanine preceding the scission site (-1 position). Mutagenesis of -1 guanines to A, C or T abrogated CL cleavage at a strong pBR322 site. Surprisingly, for double-strand breaks, scission on one strand consistently involved a modified (piperidine-labile) guanine and was not reversed by heat, salt or EDTA, whereas complementary strand scission occurred at a piperidine-stable -1 nt and was reversed by EDTA. CL did not induce cleavage by a mutant gyrase (GyrA G79A) identified here in CL-resistant pneumococci. Indeed, mutations at G79 and at the neighbouring S81 residue in the GyrA breakage-reunion domain discriminated poisoning by CL from that of antibacterial quinolones. The results suggest a novel mechanism of enzyme inhibition in which the -1 nt at the gyrase-DNA gate exhibit different CL reactivities to produce both irreversible and reversible DNA damage.

Perioperative acute upper gastrointestinal haemorrhage in older patients with hip fracture: incidence, risk factors and prevention.

BACKGROUND: No specific preventive strategy exists for acute gastrointestinal haemorrhage in hip fracture patients. AIMS: To determine the effectiveness of prophylactic use of proton pump inhibitors in patients with risk factors for acute gastrointestinal haemorrhage. METHODS: Prospective two-stage study of 822 consecutive older (> or =60 years) hip fracture patients. RESULTS: Acute gastrointestinal haemorrhage occurred in 16 (3.9%) of 407 patients and was associated with increased length of hospital stay (28.7 vs. 15.9; P = 0.0027) and mortality (18.8% vs. 4.3%; P = 0.043). Multiple analysis identified five independent risk factors for acute gastrointestinal haemorrhage: pre-existing peptic ulcer (OR 4.3; P = 0.043), current smoking (OR 3.1; P = 0.023), post-operative use of an antiplatelet agent (OR 6.5; P = 0.046), post-operative use of non-steroidal anti-inflammatory drug/cyclo-oxygenase-2 inhibitor (OR 4.9; P = 0.06) and blood group O (OR 1.7; P = 0.046). These risk factors were highly sensitive and had a negative predictive value of 99.8%. Prophylactic use of proton pump inhibitors in patients with risk factor for acute gastrointestinal haemorrhage significantly reduced the incidence of this complication (0.72% in treated patients vs. 13.4% in untreated; P < 0.001); the number needed to treat was 7.9. Conclusions In older hip fracture patients perioperative acute gastrointestinal haemorrhage occurs in 3.9% and is associated with poor outcome. Preventive proton pump inhibitor therapy in patients at risk of acute gastrointestinal haemorrhage is effective and safe.

Clerocidin interacts with the cleavage complex of Streptococcus pneumoniae topoisomerase IV to induce selective irreversible DNA damage.

Clerocidin (CL), a diterpenoid natural product, alkylates DNA through its epoxide moiety and exhibits both anticancer and antibacterial activities. We have examined CL action in the presence of topoisomerase IV from Streptococcus pneumoniae. CL promoted irreversible enzyme-mediated DNA cleavage leading to single- and double-stranded DNA breaks at specific sites. Reaction required the diterpenoid function: no cleavage was seen using a naphthalene-substituted analogue. Moreover, drug-induced DNA breakage was not observed using a mutant topoisomerase IV (ParC Y118F) unable to form a cleavage complex with DNA. Sequence analysis of 102 single-stranded DNA breaks and 79 double-stranded breaks revealed an overwhelming preference for G at the -1 position, i.e. immediately 5' of the enzyme DNA scission site. This specificity contrasts with that of topoisomerase IV cleavage with antibacterial quinolones. Indeed, CL stimulated DNA breakage by a quinolone-resistant topoisomerase IV (ParC S79F). Overall, the results indicate that topoisomerase IV facilitates selective irreversible CL attack at guanine and that its cleavage complex differs markedly from that of mammalian topoisomerase II which promotes both irreversible and reversible CL attack at guanine and cytosine, respectively. The unique ability to form exclusively irreversible DNA breaks suggests topoisomerase IV may be a key intracellular target of CL in bacteria.

Pilot study of early corticosteroid elimination after pancreas transplantation.

UNLABELLED: Early corticosteroid withdrawal has recently been shown to be possible in recipients of simultaneous pancreas kidney transplants; however, its feasibility in solitary pancreas recipients has not been documented. In the present study, we provide evidence that early withdrawal can be achieved in pancreas as well as pancreas-kidney recipients. METHODS: Twenty type I diabetics underwent 13 pancreas-kidney transplants and 7 pancreas-only transplants with early withdrawal (methylprednisone 6-day taper). Additional immunosuppression consisted of tacrolimus, mycophenolate mofetil, and thymoglobulin induction (five doses). RESULTS: Transplants included 13 pancreas-kidney, 6 pancreas after kidney transplant, and 1 pancreas after islet transplant. Overall mean follow-up was 7.3 months. One episode of pancreas transplant rejection after pancreas-only transplant was detected on protocol biopsy without biochemical abnormalities. One renal allograft rejection occurred 65 days posttransplant in a pancreas-kidney recipient and was graded as a Banff IA rejection. A single pancreas graft loss occurred due to thrombosis 6 days after pancreas-kidney transplantation. CONCLUSIONS: These results indicate that relatively short thymoglobulin induction (five doses) with tacrolimus and mycophenolate mofetil can allow early withdrawal in both pancreas-kidney and pancreas-only transplant recipients.

Cellular delivery of a double-stranded oligonucleotide NFkappaB decoy by hybridization to complementary PNA linked to a cell-penetrating peptide.

The activation of nuclear factor kappaB (NFkappaB) is a key event in immune and inflammatory responses. In this study, a cell-penetrating transport peptide, transportan (TP) or its shorter analogue TP 10, was used to facilitate the cellular uptake of an NFkappaB decoy. Peptide nucleic acid (PNA) hexamer or nonamer was linked to the transport peptide by a disulfide bond. NFkappaB decoy oligonucleotide consisted of a double-stranded consensus sequence corresponding to the kappaB site localized in the IL-6 gene promoter, 5'-GGGACTTTCCC-3', with a single-stranded protruding 3'-terminal sequence complementary to the PNA sequence was hybridized to the transport peptide-PNA construct. The ability of the transport peptide-PNA-NFkappaB decoy complex to block the effect of interleukin (IL)-1beta-induced NFkappaB activation and IL-6 gene expression was analyzed by electrophoretic mobility shift assay and reverse transcriptase-polymerase chain reaction in rat Rinm5F insulinoma cells. Preincubation with transport peptide-PNA-NFkappaB decoy (1 microM, 1 h) blocked IL-1beta-induced NFkappaB-binding activity and significantly reduced the IL-6 mRNA expression. The same concentration of NFkappaB decoy in the absence of transport peptide-PNA had no effect even after longer incubations. Our results showed that binding of the oligonucleotide NFkappaB decoy to the nonamer PNA sequence resulted in a stable complex that was efficiently translocated across the plasma membrane.

Serum levels of matrix extracellular phosphoglycoprotein (MEPE) in normal humans correlate with serum phosphorus, parathyroid hormone and bone mineral density.

Matrix extracellular phosphoglycoprotein (MEPE), a member of the Small Integrin Binding Ligand N-linked Glycoprotein (SIBLING) family, is primarily expressed in normal bone and has been proposed as a phosphaturic factor because of high expression and secretion in oncogenic hypophosphatemic osteomalacia tumors. In order to begin to address the role of MEPE in normal human physiology, we developed a competitive ELISA to measure serum levels of MEPE. The ELISA was used to characterize the distribution pattern in a population consisting of 114 normal adult subjects. The mean value of MEPE was 476 +/- 247 ng/ml and levels decreased significantly with increasing age. MEPE levels were also significantly correlated with serum phosphorus and parathyroid hormone (PTH). In addition, MEPE levels correlated significantly with measures of bone mineral density in the femoral neck and total hip in a subset of 50 elderly subjects. The results are consistent with MEPE being involved in phosphate and bone metabolism in a normal population.