194 research outputs found
Ubiquitin-dependent regulation of MEKK2/3-MEK5-ERK5 signaling module by XIAP and cIAP1
Mitogen-activated protein kinases (MAPKs) are highly conserved protein kinase modules, and they control fundamental cellular processes. While the activation of MAPKs has been well studied, little is known on the mechanisms driving their inactivation. Here we uncover a role for ubiquitination in the inactivation of a MAPK module. Extracellular-signal-regulated kinase 5 (ERK5) is a unique, conserved member of the MAPK family and is activated in response to various stimuli through a three-tier cascade constituting MEK5 and MEKK2/3. We reveal an unexpected role for Inhibitors of Apoptosis Proteins (IAPs) in the inactivation of ERK5 pathway in a bimodal manner involving direct interaction and ubiquitination. XIAP directly interacts with MEKK2/3 and competes with PB1 domain-mediated binding to MEK5. XIAP and cIAP1 conjugate predominantly K63-linked ubiquitin chains to MEKK2 and MEKK3 which directly impede MEK5-ERK5 interaction in a trimeric complex leading to ERK5 inactivation. Consistently, loss of XIAP or cIAP1 by various strategies leads to hyperactivation of ERK5 in normal and tumorigenic cells. Loss of XIAP promotes differentiation of human primary skeletal myoblasts to myocytes in a MEKK2/3-ERK5-dependent manner. Our results reveal a novel, obligatory role for IAPs and ubiquitination in the physical and functional disassembly of ERK5-MAPK module and human muscle cell differentiation
Comparison of Estimated Glomerular Filtration Rate Using Five Equations to Predict Acute Kidney Injury Following Hip Fracture Surgery
Introduction: Hip fractures are a common injury and a source of disability and mortality in the aging population. Acute kidney injury (AKI) is a common and potentially serious complication following hip fracture surgery. Estimated glomerular filtration rate (eGFR) is used as an indicator of renal function. Several equations are commonly used to calculate eGFR. The purpose of this study was 1) to evaluate the agreement between five equations in calculating eGFR, and 2) to confirm which equation can best predict AKI in patients undergoing hip fracture surgery.
Methods: 146,702 cases of surgical stabilization of hip fracture were queried from the National Surgical Quality Improvement Program (NSQIP) from 2012 to 2019. Preoperative eGFR was calculated using the Cockcroft-Gault, Modification of Diet in Renal Disease (MDRD) II, re-expressed MDRD II, Chronic Kidney Disease Epidemiology Collaboration, and Mayo quadratic (Mayo) equations. The primary outcome measure was AKI. Cases were stratified into two cohorts based on the development of postoperative AKI. These cohorts were compared based on demographic and preoperative factors. Multivariate regression analysis was used to evaluate independent associations between preoperative eGFR and postoperative renal outcomes.
Results: Six hundred ninety-nine (0.73%) patients acquired AKI after hip fracture surgery. The Mayo equation yielded the highest mean eGFR (83.8 ± 23.6), while the Re-expressed MDRD II equation yielded the lowest mean eGFR (68.3 ± 35.6). Multivariate regression analysis showed that a decrease in preoperative eGFR was independently associated with an increased risk of postoperative AKI in all five equations. The Akaike information criterion (AIC) was the lowest in the Mayo equation (5116).
Conclusions: Preoperative decrease in eGFR in all five equations was independently associated with increased risk of postoperative AKI. The Mayo equation had the highest predictive ability of acquiring postoperative AKI following hip fracture surgery
Blood Transfusions in Revision Surgery for Prosthetic Hip and Knee Infection
Background: Surgery for prosthetic joint infection (PJI) can often have significant blood loss necessitating allogeneic blood transfusion (ABT). ABT is associated with higher rates of morbidity and death in revision TJA, particularly in the treatment of PJI. It is important to understand how the rates of ABT differ among the various surgical treatments of PJI. We compared ABT rates by procedure type among patients treated for PJI a multimodal blood conservation protocol.
Methods: We retrospectively reviewed 143 operative cases of revision arthroplasty for hip and knee PJI involving 102 patients at a single institution between 2016 and 2018. Procedures were categorized as 1. irrigation and debridement (I&D) with modular component exchange (“modular component exchange”), 2. explantation with I&D and placement of antibiotic spacer (“explantation”), 3. I&D with antibiotic spacer exchange (“spacer exchange”), or 4. antibiotic spacer removal and prosthetic reimplantation (“reimplantation”). ABT rates and number of units transfused were assessed for the four procedures. Factors associated with ABT were assessed with a multilevel mixed-effects regression model.
Results: Seventy-seven cases (54%) received ABT. The highest rates of ABT occurred during explantations (74%) and spacer exchanges (72%), followed by reimplantations (36%) and modular component exchanges (33%). After adjusting for perioperative variables, lower preoperative hemoglobin level was associated with higher odds of ABT (odds ratio [OR], 1.9 [per 1-g/dL decrease]; 95% confidence interval [CI]: 1.5–2.5). Explantation (OR, 14; 95% CI: 4.0–50), reimplantation (OR, 4.3; 95% CI: 1.1–16), and spacer exchanges (OR, 5.6; 95% CI: 1.1–28) were associated with greater odds of ABT. Antibiotic spacer exchanges (OR, 26; 95% CI: 2.1-315) and explantations (OR, 11; 95% CI: 2.1-61) were associated with greater odds of multiple unit transfusions.
Discussion: Despite a restrictive transfusion protocol, ABT rates remain high in the surgical treatment of PJI. Antibiotic spacer exchange and explantation procedures had high rates of multiple unit transfusions, and additional units of blood should be made available. Preoperative anemia should be treated when possible, and further refinement of blood management protocols in prosthetic joint infection is necessary
The 72-Hour WEBT Microvariability Observation of Blazar S5 0716+714 in 2009
Context. The international whole earth blazar telescope (WEBT) consortium
planned and carried out three days of intensive micro-variability observations
of S5 0716+714 from February 22, 2009 to February 25, 2009. This object was
chosen due to its bright apparent magnitude range, its high declination, and
its very large duty cycle for micro-variations. Aims. We report here on the
long continuous optical micro-variability light curve of 0716+714 obtained
during the multi-site observing campaign during which the Blazar showed almost
constant variability over a 0.5 magnitude range. The resulting light curve is
presented here for the first time. Observations from participating
observatories were corrected for instrumental differences and combined to
construct the overall smoothed light curve. Methods. Thirty-six observatories
in sixteen countries participated in this continuous monitoring program and
twenty of them submitted data for compilation into a continuous light curve.
The light curve was analyzed using several techniques including Fourier
transform, Wavelet and noise analysis techniques. Those results led us to model
the light curve by attributing the variations to a series of synchrotron
pulses. Results. We have interpreted the observed microvariations in this
extended light curve in terms of a new model consisting of individual
stochastic pulses due to cells in a turbulent jet which are energized by a
passing shock and cool by means of synchrotron emission. We obtained an
excellent fit to the 72-hour light curve with the synchrotron pulse model
Predictors of Hospice Discharge Following Surgical Fixation of Hip Fracture
Introduction: Each year, over 300,000 people over the age of 65 are hospitalized for hip fractures, and even with co-management of patients perioperatively with a geriatric team, hip fractures in the elderly are associated with significant morbidity and mortality. Given the extreme morbidity and mortality faced by elderly patients in the post-injury period, recommendations have been put forth for the integration of palliative and even hospice care, to help improve patients’ quality of life. Our objectives were to 1) determine the proportion of patients discharged to hospice following hip fracture surgery and their 30-day mortality rates of these patients, and 2) identify the independent predictors of discharge to hospice.
Methods: We retrospectively queried the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) for all hip fractures surgeries between the years of 2016 and 2018. Included cases were stratified into two cohorts: cases involving a discharge to hospice and non-hospice discharge. Variables assessed included patient demographics, comorbidities, perioperative characteristics, and postoperative outcomes. Differences between hospice and non-hospice patients were compared using chi-squared analysis or Fisher\u27s exact test for categorical variables and Student’s t-tests for continuous variables. A binary logistic regression model was used to assess independent predictors of hospice discharge with 30-day mortality.
Results: Overall, 31,531 operatively treated hip fractures were identified, of which 281 (0.9%) involved a discharge to hospice. Patients discharged to hospice had a 67% 30-day mortality rate in comparison to 5.6% of patients not discharged to hospice (p \u3c 0.001). Disseminated cancer, dependent functional status, \u3e10% weight loss over six months preoperatively, and preoperative cognitive deficit were the strongest predictors of hospice discharge with 30-day mortality following hip fracture surgery.
Conclusions: Current hospice utilization in hip fracture patients remains low, but 30-day mortality in these patients is high. An awareness of the associations between patient characteristics and discharge to hospice with 30-day mortality is important for surgeons to consider when discussing postoperative expectations and outcomes with these patients
A Simple Method for DNA Extraction from Mature Date Palm Leaves: Impact of Sand Grinding and Composition of Lysis Buffer
Molecular marker techniques have been widely used for cultivar identification of inbred date palms (Phoenix dactylifera L.; Arecaceae) and biodiversity conservation. Isolation of highly pure DNA is the prerequisite for PCR amplification and subsequent use such as DNA fingerprinting and sequencing of genes that have recently been developed for barcoding. To avoid problems related to the preservation and use of liquid nitrogen, we examined sterile sand for grinding the date palm leaves. Individual and combined effects of sodium chloride (NaCl), polyvinylpyrrolidone (PVP) and lithium chloride (LiCl) with the cetyltrimethylammonium bromide (CTAB) method for a DNA yield of sufficient purity and PCR amplification were evaluated in this study. Presence of LiCl and PVP alone or together in the lysis buffer did not significantly improve the DNA yield and purity compared with the addition of NaCl. Our study suggested that grinding of date palm leaf with sterile sand and inclusion of NaCl (1.4 M) in the lysis buffer without the costly use of liquid nitrogen, PVP and LiCl, provides a DNA yield of sufficient purity, suitable for PCR amplification
Endophytic Bacteria from Ocimum sanctum and Their Yield Enhancing Capabilities
Abstract Endophytes are beneficial microbes that reside intercellularly inside the plants. Interaction of endophytes with the host plants and their function within their host are important to address ecological relevance of endophyte. Four endophytic bacteria OS-9, OS-10, OS-11, and OS-12 were isolated from healthy leaves of Ocimum sanctum
Qualitative analysis of essential oil of Rosmarinus officinalis L. cultivated in Uttaranchal Hills, India
Gas chromatography and gas chromatography and mass spectroscopy analysis of essentialoil hydrodistilled from fresh aerial part of rosemary (Rosmarinus officinalis) cultivated inUttaranchal, India, resolved into 33 compounds representing 96.29% of the essential oilaccording to their chromatographic retention indices and mass spectra. The major compoundsof the oil were, camphor (26.40%), 1, 8-cineole (23.40%), α-pinene (9.94%), camphene (5.83%),myrcene (4.86%), bornyl acetate (3.97%), verbenone (3.32%), limonene (3.08%), borneol(2.05%) and α-terpineol (2.68%).
 
Caracterização citogenĂ©tica para identificação dos nĂveis de ploidia em cinco espĂ©cies do gĂŞnero Mentha L.
An Analysis of the Role of the Indigenous Microbiota in Cholesterol Gallstone Pathogenesis
Background and Aims:
Cholesterol gallstone disease is a complex process involving both genetic and environmental variables. No information exists regarding what role if any the indigenous gastrointestinal microbiota may play in cholesterol gallstone pathogenesis and whether variations in the microbiota can alter cholesterol gallstone prevalence rates.
Methods:
Genetically related substrains (BALB/cJ and BALB/cJBomTac) and (BALB/AnNTac and BALB/cByJ) of mice obtained from different vendors were compared for cholesterol gallstone prevalence after being fed a lithogenic diet for 8 weeks. The indigenous microbiome was altered in these substrains by oral gavage of fecal slurries as adults, by cross-fostering to mice with divergent flora at <1day of age or by rederiving into a germ-free state.
Results:
Alterations in the indigenous microbiome altered significantly the accumulation of mucin gel and normalized gallbladder weight but did not alter cholesterol gallstone susceptibility in conventionally housed SPF mice. Germ-free rederivation rendered mice more susceptible to cholesterol gallstone formation. This susceptibility appeared to be largely due to alterations in gallbladder size and gallbladder wall inflammation. Colonization of germ-free mice with members of altered Schaedler flora normalized the gallstone phenotype to a level similar to conventionally housed mice.
Conclusions:
These data demonstrate that alterations in the gastrointestinal microbiome may alter aspects of cholesterol gallstone pathogenesis and that in the appropriate circumstances these changes may impact cholesterol cholelithogenesis.National Institutes of Health (U.S.) (Grant T32OD010978)National Institutes of Health (U.S.) (Grant P30ES002109)National Institutes of Health (U.S.) (Grant R01AT004326
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