RIPK1 and RIPK3 Kinases Promote Cell-Death-Independent Inflammation by Toll-like Receptor 4.

Macrophages are a crucial component of the innate immune system in sensing pathogens and promoting local and systemic inflammation. RIPK1 and RIPK3 are homologous kinases, previously linked to activation of necroptotic death. In this study, we have described roles for these kinases as master regulators of pro-inflammatory gene expression induced by lipopolysaccharide, independent of their well-documented cell death functions. In primary macrophages, this regulation was elicited in the absence of caspase-8 activity, required the adaptor molecule TRIF, and proceeded in a cell autonomous manner. RIPK1 and RIPK3 kinases promoted sustained activation of Erk, cFos, and NF-κB, which were required for inflammatory changes. Utilizing genetic and pharmacologic tools, we showed that RIPK1 and RIPK3 account for acute inflammatory responses induced by lipopolysaccharide in vivo; notably, this regulation did not require exogenous manipulation of caspases. These findings identified a new pharmacologically accessible pathway that may be relevant to inflammatory pathologies.

The impact of phenotypic heterogeneity of tumour cells on treatment and relapse dynamics.

Intratumour heterogeneity is increasingly recognized as a frequent problem for cancer treatment as it allows for the evolution of resistance against treatment. While cancer genotyping becomes more and more established and allows to determine the genetic heterogeneity, less is known about the phenotypic heterogeneity among cancer cells. We investigate how phenotypic differences can impact the efficiency of therapy options that select on this diversity, compared to therapy options that are independent of the phenotype. We employ the ecological concept of trait distributions and characterize the cancer cell population as a collection of subpopulations that differ in their growth rate. We show in a deterministic model that growth rate-dependent treatment types alter the trait distribution of the cell population, resulting in a delayed relapse compared to a growth rate-independent treatment. Whether the cancer cell population goes extinct or relapse occurs is determined by stochastic dynamics, which we investigate using a stochastic model. Again, we find that relapse is delayed for the growth rate-dependent treatment type, albeit an increased relapse probability, suggesting that slowly growing subpopulations are shielded from extinction. Sequential application of growth rate-dependent and growth rate-independent treatment types can largely increase treatment efficiency and delay relapse. Interestingly, even longer intervals between decisions to change the treatment type may achieve close-to-optimal efficiencies and relapse times. Monitoring patients at regular check-ups may thus provide the temporally resolved guidance to tailor treatments to the changing cancer cell trait distribution and allow clinicians to cope with this dynamic heterogeneity.

Is SIRT2 required for necroptosis?

Sirtuins can promote deacetylation of a wide range of substrates in diverse cellular compartments and regulate many cellular processes¹,². Recently Narayan et al., reported that SIRT2 was required for necroptosis based on their findings that SIRT2 inhibition, knock-down or knock-out prevented necroptosis. We sought to confirm and explore the role of SIRT2 in necroptosis and tested four different sources of the SIRT2 inhibitor AGK2, three independent siRNAs against SIRT2, and cells from two independently generated Sirt2−/− mouse strains, however we were unable to show that inhibiting or depleting SIRT2 protected cells from necroptosis. Furthermore, Sirt2−/− mice succumbed to TNF induced Systemic Inflammatory Response Syndrome (SIRS) more rapidly than wild type mice while Ripk3−/− mice were resistant. Our results therefore question the importance of SIRT2 in the necroptosis cell death pathway.

Kinase Activities of RIPK1 and RIPK3 Can Direct IFN-ß Synthesis Induced by Lipopolysaccharide.

The innate immune response is a central element of the initial defense against bacterial and viral pathogens. Macrophages are key innate immune cells that upon encountering pathogen-associated molecular patterns respond by producing cytokines, including IFN-ß. In this study, we identify a novel role for RIPK1 and RIPK3, a pair of homologous serine/threonine kinases previously implicated in the regulation of necroptosis and pathologic tissue injury, in directing IFN-ß production in macrophages. Using genetic and pharmacologic tools, we show that catalytic activity of RIPK1 directs IFN-ß synthesis induced by LPS in mice. Additionally, we report that RIPK1 kinase-dependent IFN-ß production may be elicited in an analogous fashion using LPS in bone marrow-derived macrophages upon inhibition of caspases. Notably, this regulation requires kinase activities of both RIPK1 and RIPK3, but not the necroptosis effector protein, MLKL. Mechanistically, we provide evidence that necrosome-like RIPK1 and RIPK3 aggregates facilitate canonical TRIF-dependent IFN-ß production downstream of the LPS receptor TLR4. Intriguingly, we also show that RIPK1 and RIPK3 kinase-dependent synthesis of IFN-ß is markedly induced by avirulent strains of Gram-negative bacteria, Yersinia and Klebsiella, and less so by their wild-type counterparts. Overall, these observations identify unexpected roles for RIPK1 and RIPK3 kinases in the production of IFN-ß during the host inflammatory responses to bacterial infection and suggest that the axis in which these kinases operate may represent a target for bacterial virulence factors.

Postmortem ICD interrogation in mode of death classification.

BACKGROUND: The definition of sudden death due to arrhythmia relies on the time interval between onset of symptoms and death. However, not all sudden deaths are due to arrhythmia. In patients with an implantable cardioverter defibrillator (ICD), postmortem device interrogation may help better distinguish the mode of death compared to a time-based definition alone. OBJECTIVE: This study aims to assess the proportion of "sudden" cardiac deaths in patients with an ICD that have confirmed arrhythmia. METHODS: We conducted a literature search for studies using postmortem ICD interrogation and a time-based classification of the mode of death. A modified QUADAS-2 checklist was used to assess risk of bias in individual studies. Outcome data were pooled where sufficient data were available. RESULTS: Our search identified 22 studies undertaken between 1982 and 2015 with 23,600 participants. The pooled results (excluding studies with high risk of bias) suggest that ventricular arrhythmias are present at the time of death in 76% of "sudden" deaths (95% confidence interval [CI] 67-85; range 42-88). CONCLUSION: Postmortem ICD interrogation identifies 24% of "sudden" deaths to be nonarrhythmic. Postmortem device interrogation should be considered in all cases of unexplained sudden cardiac death.

Five historical innovations that have shaped modern urological surgery.

Throughout history, many innovations have contributed to the development of modern urological surgery, improving patient outcomes and expanding the range of treatment options available to patients. This article explores five key historical innovations that have shaped modern urological surgery: External shockwave lithotripsy, transurethral resection of prostate, cystoscope, perioperative prostate-specific antigen and robotic surgery. The selection of innovations for inclusion in this article was meticulously determined through expert consensus and an extensive literature review. We will review the development, impact and significance of each innovation, highlighting their contributions to the field of urological surgery and their ongoing relevance in contemporary and perioperative practice.

Five historical innovations that have shaped modern cardiothoracic surgery.

Throughout history, many innovations have contributed to the development of modern cardiothoracic surgery, improving patient outcomes and expanding the range of treatment options available to patients. This article explores five key historical innovations that have shaped modern cardiothoracic surgery: cardiopulmonary bypass, surgical pacemakers, video assisted thoracic surgery, robotic surgery and mechanical circulatory support. We will review the development, impact and significance of each innovation, highlighting their contributions to the field of cardiothoracic surgery and their ongoing relevance in contemporary and perioperative practice.

Five historical innovations that have shaped modern otolaryngological surgery.

Throughout history, many innovations have contributed to the development of modern otolaryngological surgery, improving patient outcomes and expanding the range of treatment options available to patients. This article explores five key historical innovations that have shaped modern otolaryngological surgery: Operative Microscope, Hopkins Rigid Endoscope, Laryngeal Nerve monitoring, Cochlear implants and Laser surgery. The selection of innovations for inclusion in this article was meticulously determined through expert consensus and an extensive literature review. We will review the development, impact and significance of each innovation, highlighting their contributions to the field of otolaryngological surgery and their ongoing relevance in contemporary and perioperative practice.

Understanding and leveraging phenotypic plasticity during metastasis formation.

Cancer metastasis is the process of detrimental systemic spread and the primary cause of cancer-related fatalities. Successful metastasis formation requires tumor cells to be proliferative and invasive; however, cells cannot be effective at both tasks simultaneously. Tumor cells compensate for this trade-off by changing their phenotype during metastasis formation through phenotypic plasticity. Given the changing selection pressures and competitive interactions that tumor cells face, it is poorly understood how plasticity shapes the process of metastasis formation. Here, we develop an ecology-inspired mathematical model with phenotypic plasticity and resource competition between phenotypes to address this knowledge gap. We find that phenotypically plastic tumor cell populations attain a stable phenotype equilibrium that maintains tumor cell heterogeneity. Considering treatment types inspired by chemo- and immunotherapy, we highlight that plasticity can protect tumors against interventions. Turning this strength into a weakness, we corroborate current clinical practices to use plasticity as a target for adjuvant therapy. We present a parsimonious view of tumor plasticity-driven metastasis that is quantitative and experimentally testable, and thus potentially improving the mechanistic understanding of metastasis at the cell population level, and its treatment consequences.

In vitro release of organophosphorus acid anhydrolase from functionalized mesoporous silica against nerve agents.

We report here that under different physiological conditions, biomolecular drugs can be stockpiled in a nanoporous support and afterward can be instantly released when needed for acute responses, and the biomolecular drug molecules can also be gradually released from the nanoporous support over a long time for a complete recovery. Organophosphorus acid anhydrolase (OPAA) was spontaneously and largely entrapped in functionalized mesoporous silica (FMS) due to the dominant electrostatic interaction. The OPAA-FMS composite exhibited a burst release in a pH 9.0 NaHCO3-Na2CO3 buffer system and a gradual release in pH 7.4 simulated body fluid. The binding of OPAA to NH2-FMS can result in less tyrosinyl and tryptophanyl exposure OPAA molecules to aqueous environment. The bound OPAA in FMS displayed lower activity than the free OPAA in solution prior to the enzyme entrapment. However, the released enzyme maintained the native conformational structure and the same high enzymatic activity as that prior to the enzyme entrapment. The in vitro results in the rabbit serum demonstrate that both OPAA-FMS and the released OPAA may be used as a medical countermeasure against the organophosphorus nerve agents.

A larger sized cup accelerates cartilage erosion of acetabulum after bipolar hemiarthroplasty in elderly with femur neck fracture.

ABSTRACT: Bipolar hemiarthroplasty (BHA) is one of the common procedures done for the treatment of femur neck fracture. One of the frequently encountered complication with this surgery is erosion of the acetabular cartilage. This study was conducted to investigate acetabular erosion after BHA according to the difference in diameter between femoral head and implanted cup at minimum 10-year follow-up.We retrospectively reviewed 117 patients (117 hips) undergoing BHA with fracture of neck of the femur. Their mean age was 77.8 years (range, 65-96 years) and male: female ratio was 32:85. Patients were divided into 3 groups; Group A - bipolar cup size > actual head size, Group B - cup size < head size, Group C - cup size = head size. The degree of both superior and medial acetabular cartilage erosion was identified and calculated on postoperative radiographs using line of acetabular margin and Kohler line.The mean superior and medial acetabular erosion were 1.62 ±â€Š1.6 mm (range, 0-4.4) and 4.15 ±â€Š2.7 mm (range, 0-8.2) in Group A, 1.30 ±â€Š1.3 mm (range, 0-3.8) and 4.11 ±â€Š2.7 mm (range, 0-7.8) in Group B, and 0.90 ±â€Š1.1 mm (range, 0-2.6) and 3.16 ±â€Š2.9 mm (range, 0-7.9) in Group C (P = .039 and P = .187, respectively). The superior acetabular erosion showed significant difference between the 3 groups. During mean follow-up period of 12.3 years, 5 patients (5/117, 4.3%) underwent conversion to total hip arthroplasty due to superior acetabular erosion. All of 3 patient underwent BHA with a larger bipolar cup than the actual femoral head.A lager sized cup accelerated superior cartilage erosion of acetabulum after BHA. An optimal cup size should be considered when undergoing BHA in elderly patients.

Phenotypic Correction of Murine Mucopolysaccharidosis Type II by Engraftment of Ex Vivo Lentiviral Vector-Transduced Hematopoietic Stem and Progenitor Cells.

Mucopolysaccharidosis type II (MPS II, Hunter syndrome) is an X-linked recessive lysosomal disease caused by deficiency of iduronate-2-sulfatase (IDS). The absence of IDS results in the accumulation of the glycosaminoglycans (GAGs) heparan sulfate and dermatan sulfate. Currently, the only approved treatment option for MPS II is enzyme replacement therapy (ERT), Elaprase. However, ERT is demanding for the patient and does not ameliorate neurological manifestations of the disease. Using an IDS-deficient mouse model that phenocopies the human disease, we evaluated hematopoietic stem and progenitor cells (HSPCs) transduced with a lentiviral vector (LVV) carrying a codon-optimized human IDS coding sequence regulated by a ubiquitous MNDU3 promoter (MNDU3-IDS). Mice treated with MNDU3-IDS LVV-transduced cells showed supraphysiological levels of IDS enzyme activity in plasma, peripheral blood mononuclear cells, and in most analyzed tissues. These enzyme levels were sufficient to normalize GAG storage in analyzed tissues. Importantly, IDS levels in the brains of MNDU3-IDS-engrafted animals were restored to 10-20% than that of wild-type mice, sufficient to normalize GAG content and prevent emergence of cognitive deficit as evaluated by neurobehavioral testing. These results demonstrate the potential effectiveness of ex vivo MNDU3-IDS LVV-transduced HSPCs for treatment of MPS II.

Improving the catalytic activity of hyperthermophilic Pyrococcus horikoshii prolidase for detoxification of organophosphorus nerve agents over a broad range of temperatures.

Prolidases hydrolyze Xaa-Pro dipeptides and can also cleave the P-F and P-O bonds found in organophosphorus (OP) compounds, including the nerve agents soman and sarin. Ph1prol (PH0974) has previously been isolated and characterized from Pyrococcus horikoshii and was shown to have higher catalytic activity over a broader pH range, higher affinity for metal, and increased thermostability compared to P. furiosus prolidase, Pfprol (PF1343). To obtain a better enzyme for OP nerve agent decontamination and to investigate the structural factors that may influence protein thermostability and thermoactivity, randomly mutated Ph1prol enzymes were prepared. Four Ph1prol mutants (A195T/G306S-, Y301C/K342N-, E127G/E252D-, and E36V-Ph1prol) were isolated which had greater thermostability and improved activity over a broader range of temperatures against Xaa-Pro dipeptides and OP nerve agents compared to wild type Pyrococcus prolidases.

Comparison of procedural times, success rates, and safety between left versus right radial arterial access in primary percutaneous coronary intervention for acute ST-segment elevation myocardial infarction.

OBJECTIVE: To evaluate if there are differences in procedural times, success rates, and safety between left and right radial approach (LRA and RRA, respectively) in primary percutaneous coronary intervention (PCI) for ST-elevation myocardial infarction (STEMI). BACKGROUND: Given conflicting reports of different procedural success with LRA vs. RRA, it is unclear if the side of radial access impacts in-room procedural times and success rates in primary PCI. At our institution the LRA has been commonly used in certain STEMI patients. Our clinical database was reviewed to see if routine use of the LRA could generate favorable technical success and reperfusion times as compared to the RRA. METHODS: We retrospectively analyzed 135 consecutive STEMI patients treated with primary PCI performed via the left and right radial approach at our institution. RESULTS: There were 50 cases in the LRA group and 85 in the RRA group. There was no difference in median procedural times including total procedure time (LRA 53.5 mins vs. RRA 52 mins, P = 0.95), room-to-cannulation (LRA 12 min vs. RRA 13 min, P = 0.40) or room-to-balloon times (LRA 30 min vs. RRA 31 min, P = 0.74). There were no significant differences in procedural success rates (LRA 100% vs. RRA 97.6%, P = 0.27), or procedure-related complications or death between the two groups. CONCLUSIONS: Left and right trans-radial approach for primary PCI have similar in room procedural times, success rates, and comparable safety. Trans-radial PCI through either arm is a feasible and safe approach in patients with STEMI.

Correlation of endoscopic findings with Doppler ultrasound in portal hypertension in children.

AIM OF THE STUDY: To determine the correlation of the endoscopic findings with portal Doppler and ultrasound (USG) in children with suspected portal hypertension (PHT). MATERIAL AND METHODS: Eighty children with extrahepatic portal vein obstruction (EHPVO) and chronic liver disease (CLD) were included in this retrospective study conducted over a period of 1 year. All patients underwent upper gastrointestinal (GI) endoscopy and Doppler. RESULTS: The etiology was EHPVO in 30 (37.5%) patients, biliary atresia in 12 (15%), Budd-Chiari syndrome in 11 (13.7%), Wilson's disease in 10 (12.5%), idiopathic CLD in 8 (10%), autoimmune hepatitis in 4 (5%), glycogen storage disease (GSD) in 3 (3.8%), non-alcoholic liver disease (NAFLD) in 1 (1.3%) and systemic lupus erythematosus (SLE) in 1 (1.3%) patient. Fifty-three (66.25%) patients had esophageal varices on endoscopy, of whom 3 (3.8%) had associated gastric varices. Portal hypertensive gastropathy (PHG) was present in 30 (37.5%) patients, of whom 10 (12.5%) had severe PHG. Forty-one (51.3%) patients had PHT on Doppler (κ correlation 0.43). Kappa correlation was 0.43 in patients with biliary atresia, 0.31 in Budd-Chiari syndrome, 0.23 in idiopathic CLD, 0.21 in CLD, and 0.05 in Wilson's disease. All (100%) EHPVO patients and 39 (78%) CLD patients had PHT on USG. Endoscopic findings of PHT were seen in 24 (80%) EHPVO patients and 29 (58%) CLD patients. All patients with EHPVO had cavernous transformation of the portal vein on Doppler. For patients with CLD, the common Doppler findings were collaterals seen in 35 patients and reversal of flow in 12 patients. CONCLUSIONS: Doppler ultrasound followed by endoscopy should be used to diagnose PHT in children. In children with biliary atresia, Doppler ultrasound may miss changes of PHT.

Safe Elective Surgical Practice During COVID-19 Pandemic - A Prospective Observational Study of 303 Elective Surgeries in the UK.

Aim During the COVID-19 pandemic, there has been worldwide cancellation of elective surgeries to protect patients from nosocomial viral transmission and peri-operative complications. With the unfolding situation, there is a definite need for an exit strategy to reinstate elective services. Therefore, more literature evidence supporting exit plans for elective surgical services is imperative to adopt a safe working principle. This study aims to provide evidence for safe elective surgical practice during the pandemic. Methodology This single centre, prospective, observational study included adult patients who were admitted and underwent elective surgical procedures in the trust's COVID-free environment at the Birmingham Treatment Centre between May 19 and July 14, 2020. Data were collected on demographic parameters, peri-operative variables, surgical specialities, COVID-19 reverse transcription polymerase chain reaction (RT-PCR) testing results, post-operative complications and mortality. The study also highlighted the protocols it followed for the elective services during the pandemic. Results A total of 303 patients were included with mean age of 49.9 years (SD 16.5) comprising of 59% (178) female and 41% (125) male. They were classified according to the American Society of Anaesthesiologist Grade, different surgical specialities and types of anaesthesia used. Ninety-six percent (96%) of patients were discharged on the same day. Hundred percent (100%) compliance with pre-operative COVID-19 RT-PCR testing was maintained. There was no 30-day mortality or major respiratory complications. Conclusion Careful patient selection, simultaneous involvement of the pre-assessment and anaesthetic team, strict adherence to peri-operative protocols and delivering vigilant post-operative care for COVID-19 infection can help provide safe elective surgical services if the community transmission is under reasonable control. However, it is particularly important to maintain COVID-free safe environment for such procedures.

Structural insights into the dual activities of the nerve agent degrading organophosphate anhydrolase/prolidase.

The organophosphate acid anhydrolase (OPAA) is a member of a class of bimetalloenzymes that hydrolyze a variety of toxic acetylcholinesterase-inhibiting organophosphorus compounds, including fluorine-containing chemical nerve agents. It also belongs to a family of prolidases, with significant activity against various Xaa-Pro dipeptides. Here we report the X-ray structure determination of the native OPAA (58 kDa mass) from Alteromonas sp. strain JD6.5 and its cocrystal with the inhibitor mipafox [N,N'-diisopropyldiamidofluorophosphate (DDFP)], a close analogue of the nerve agent organophosphate substrate diisopropyl fluorophosphate (DFP). The OPAA structure is composed of two domains, amino and carboxy domains, with the latter exhibiting a "pita bread" architecture and harboring the active site with the binuclear Mn(2+) ions. The native OPAA structure revealed unexpectedly the presence of a well-defined nonproteinaceous density in the active site whose identity could not be definitively established but is suggestive of a bound glycolate, which is isosteric with a glycine (Xaa) product. All three glycolate oxygens coordinate the two Mn(2+) atoms. DDFP or more likely its hydrolysis product, N,N'-diisopropyldiamidophosphate (DDP), is present in the cocrystal structure and bound by coordinating the binuclear metals and forming hydrogen bonds and nonpolar interactions with active site residues. An unusual common feature of the binding of the two ligands is the involvement of only one oxygen atom of the glycolate carboxylate and the product DDP tetrahedral phosphate in bridging the two Mn(2+) ions. Both structures provide new understanding of ligand recognition and the prolidase and organophosphorus hydrolase catalytic activities of OPAA.

Systematic evaluation of the efficacy of chlorine dioxide in decontamination of building interior surfaces contaminated with anthrax spores.

Efficacy of chlorine dioxide (CD) gas generated by two distinct generation systems, Sabre (wet system with gas generated in water) and ClorDiSys (dry system with gas generated in air), was evaluated for inactivation of Bacillus anthracis spores on six building interior surfaces. The six building materials included carpet, acoustic ceiling tile, unpainted cinder block, painted I-beam steel, painted wallboard, and unpainted pinewood. There was no statistically significant difference in the data due to the CD generation technology at a 95% confidence level. Note that a common method of CD gas measurement was used for both wet and dry CD generation types. Doses generated by combinations of different concentrations of CD gas (500, 1,000, 1,500, or 3,000 parts per million of volume [ppmv]) and exposure times (ranging between 0.5 and 12 h) were used to evaluate the relative role of fumigant exposure period and total dose in the decontamination of building surfaces. The results showed that the time required to achieve at least a 6-log reduction in viable spores is clearly a function of the material type on which the spores are inoculated. The wood and cinder block coupons required a longer exposure time to achieve a 6-log reduction. The only material showing a clear statistical difference in rate of decay of viable spores as a function of concentration was cinder block. For all other materials, the profile of spore kill (i.e., change in number of viable spores with exposure time) was not dependent upon fumigant concentration (500 to 3,000 ppmv). The CD dose required for complete spore kill on biological indicators (typically, 1E6 spores of Bacillus atrophaeus on stainless steel) was significantly less than that required for decontamination of most of the building materials tested.

Hepatic Portal Venous Gas: An Ill Omen or a Misleading Sign.

Hepatic portal venous gas (HPVG), a rare radiological finding, is historically considered an ominous sign with 100% mortality rates. The dictum that HPVG warrants surgical intervention is challenged in the recent literature. This is because of the identification of various causes of HVPG other than bowel gangrene. Most of these newly identified causes can be managed conservatively. However, bowel gangrene, if missed, is fatal. Hence, sound clinical judgment and accurate diagnosis based on specific clinical parameters and imaging findings are important. We present a case of a young male with tumor lysis syndrome and neutropenic sepsis. He underwent treatment for a relapse of T-cell acute lymphocytic leukemia and presented with abdominal pain and distension. Computed tomography (CT) scan showed HPVG, and the differential diagnosis was neutropenic colitis or pseudomembranous colitis, with steroid use as the probable cause. The patient was managed conservatively. The case emphasizes that the evaluation for a specific cause of HPVG is important to reduce unnecessary surgery. A succinct literature review provides the reasons for the changing mortality rates.