FMRP deficiency leads to multifactorial dysregulation of splicing and mislocalization of MBNL1 to the cytoplasm.

Fragile X syndrome (FXS) is a neurodevelopmental disorder that is often modeled in Fmr1 knockout mice where the RNA-binding protein FMRP is absent. Here, we show that in Fmr1-deficient mice, RNA mis-splicing occurs in several brain regions and peripheral tissues. To assess molecular mechanisms of splicing mis-regulation, we employed N2A cells depleted of Fmr1. In the absence of FMRP, RNA-specific exon skipping events are linked to the splicing factors hnRNPF, PTBP1, and MBNL1. FMRP regulates the translation of Mbnl1 mRNA as well as Mbnl1 RNA auto-splicing. Elevated Mbnl1 auto-splicing in FMRP-deficient cells results in the loss of a nuclear localization signal (NLS)-containing exon. This in turn alters the nucleus-to-cytoplasm ratio of MBNL1. This redistribution of MBNL1 isoforms in Fmr1-deficient cells could result in downstream splicing changes in other RNAs. Indeed, further investigation revealed that splicing disruptions resulting from Fmr1 depletion could be rescued by overexpression of nuclear MBNL1. Altered Mbnl1 auto-splicing also occurs in human FXS postmortem brain. These data suggest that FMRP-controlled translation and RNA processing may cascade into a general dys-regulation of splicing in Fmr1-deficient cells.

Antisense oligonucleotide rescue of CGG expansion-dependent FMR1 mis-splicing in fragile X syndrome restores FMRP.

Aberrant alternative splicing of mRNAs results in dysregulated gene expression in multiple neurological disorders. Here, we show that hundreds of mRNAs are incorrectly expressed and spliced in white blood cells and brain tissues of individuals with fragile X syndrome (FXS). Surprisingly, the FMR1 (Fragile X Messenger Ribonucleoprotein 1) gene is transcribed in >70% of the FXS tissues. In all FMR1-expressing FXS tissues, FMR1 RNA itself is mis-spliced in a CGG expansion-dependent manner to generate the little-known FMR1-217 RNA isoform, which is comprised of FMR1 exon 1 and a pseudo-exon in intron 1. FMR1-217 is also expressed in FXS premutation carrier-derived skin fibroblasts and brain tissues. We show that in cells aberrantly expressing mis-spliced FMR1, antisense oligonucleotide (ASO) treatment reduces FMR1-217, rescues full-length FMR1 RNA, and restores FMRP (Fragile X Messenger RibonucleoProtein) to normal levels. Notably, FMR1 gene reactivation in transcriptionally silent FXS cells using 5-aza-2'-deoxycytidine (5-AzadC), which prevents DNA methylation, increases FMR1-217 RNA levels but not FMRP. ASO treatment of cells prior to 5-AzadC application rescues full-length FMR1 expression and restores FMRP. These findings indicate that misregulated RNA-processing events in blood could serve as potent biomarkers for FXS and that in those individuals expressing FMR1-217, ASO treatment may offer a therapeutic approach to mitigate the disorder.

Human Immunodeficiency Virus Associated Plasmablastic Lymphoma Involving Bones and Peritoneum in a 4-Year-old Child.

In children with underlying Human Immunodeficiency virus infection and AIDS, hematolymphoid cancers, especially non-hodgkin lymphomas are common. Plasmablastic lymphoma is one such non-hodgkin lymphomas arising from the head and neck region (especially sinonasal) but extremely rare. We describe the clinical course in a 4-year-old boy who presented with a solitary bony swelling of the right knee joint, which on diagnostic work-up turned out to be plasmablastic lymphoma. With combination chemotherapy, intrathecal chemotherapy, and early institution ofHighly active anti-retroviral therapy, the child continues to be in remission.

Can 18 F-FDG-Positron Emission Tomography be a Prognostic Tool in Children With Rhabdomyosarcoma Treated With Definitive Radiotherapy?

BACKGROUND: Persisting residual masses at treatment completion are known in rhabdomyosarcoma (RMS) treated with definitive radiotherapy (RT) to the primary site, but their prognostic significance is uncertain. Tumor response as assessed by anatomic imaging is not prognostic and studies based on 18 F-FDG-PET response are limited. We report the prognostic significance of persistent FDG-avidity in residual masses, assessed 3-month postdefinitive RT, in pediatric RMS. MATERIALS AND METHODS: Children 15 years old or below with Group III/IV RMS who received only definitive radiotherapy for local control from June 2013 to December 2018, and had 18 F-FDG-PET CT at 3 months post-RT were retrospectively analyzed for outcomes and other prognostic factors. RESULTS: Sixty-three children were eligible (Group III-55, Group IV-8). 18 F-FDG-PET CT scan done 3 months postradiotherapy showed FDG-avid residual masses in 10 patients (15.9%), anatomic residual in 24 (38.1%), and no anatomic/FDG-avid residual in 29(46.0%). At a median follow-up of 38 months (interquartile range, 24 to 55 mo), 3-year EFS of patients with FDG-avid residual masses was 40.0% (95% CI: 18.7% to 85.5%) versus the rest of the cohort, which was 71.9% (95% CI: 59.8% to 86.5%) ( P =0.008). Three-year OS of patients with FDG-avid residual masses was 50.8% (95% CI: 25.7% to 100.0%) versus the rest of the cohort, which was 77.0% (95% CI: 65.1% to 91.0%) ( P =0.037). Presence of FDG-avid residual disease persisting post-RT affected both EFS [HR-3.34 (95% CI: 1.29 to 8.68) ( P =0.013)] and OS [HR-3.20 (95% CI: 1.01 to 10.12) ( P =0.048)] on univariate analysis and this significance was retained for EFS in multivariate analysis [HR-3.52 (95% CI: 1.33 to 9.30) ( P =0.011)]. CONCLUSIONS: Persistent metabolic activity in residual disease post-chemoradiotherapy in RMS may portend a poorer prognosis with an increased risk of relapse. This subset of high-risk patients needs to be identified, and further trials are warranted to develop strategies to improve their outcomes.

Post-intubation analgesia and sedation following succinylcholine vs. rocuronium in the emergency department.

BACKGROUND: Succinylcholine and rocuronium are the most commonly utilized neuromuscular blocker agents (NMBAs) for rapid sequence intubation (RSI) in the emergency department (ED). The duration of action of rocuronium is significantly longer (∼30 min) compared to succinylcholine (∼10 min) and previous studies have shown that patients receiving rocuronium are more likely to have longer time to sedation initiation following RSI. Furthermore, patients receiving rocuronium may be more likely to experience awareness with paralysis than those receiving succinylcholine. The primary goal for this study was to evaluate the association between NMBA use during RSI and post-intubation sedation and analgesia practices in the ED. METHODS: This was a retrospective, multicenter cohort study including patients 18 years and older that received succinylcholine or rocuronium during RSI in the ED between September 1, 2020 and August 31, 2021. Patients were excluded if they were intubated prior to ED arrival, experienced an out-of-hospital or in ED cardiac arrest, or received sugammadex within 60 min of rocuronium administration. Patients were screened in reverse chronological order until the targeted sample size was achieved and all data was abstracted from the electronic health record. The primary outcome was the time to initiation of analgesia or sedation. Secondary outcomes included dose of sedatives or analgesia administered at 30- and 60 min, and medications administered for post-intubation sedation or analgesia. FINDINGS: A total of 200 ED patients were included of which 100 received succinylcholine and 100 received rocuronium. There was no difference in the median time to initiation of analgesia or sedation between the succinylcholine and rocuronium groups (10 vs 8.5 min, p = 0.82) or in Kaplan-Meier cumulative probabilities (p = 0.17). At 60 min post-RSI, those receiving succinylcholine received significantly higher median doses of propofol (20 µg/kg/min vs. 10 µg/kg/min; p = 0.02) and fentanyl [100 µg vs. 84.2 µg; p = 0.02]. CONCLUSION: While no differences were observed in the time to initiation of post-intubation sedation or analgesia in ED patients receiving succinylcholine compared to rocuronium, differences in the intensity of post-intubation regimens was observed. Further investigation is needed to evaluate the adequacy of sedation following RSI in the ED.

Liposomal Bupivacaine Versus Immediate-Release Bupivacaine for Postoperative Pain Control.

BACKGROUND: Liposomal bupivacaine (LB) is increasingly being used for postoperative pain control, but there are conflicting efficacy data when compared with immediate-release bupivacaine (IRB). OBJECTIVE: To evaluate the comparative efficacies of LB and IRB for postoperative pain control in order to assess the formulary status of LB at our institution. METHODS: A single-center, retrospective, institutional review board-approved, noninferiority matched cohort study at a tertiary care academic medical center. Adult surgical patients admitted for >24 hours who received LB or IRB were included. The primary outcome was total opioid consumption within 24 hours postoperatively. Secondary outcomes included total opioid consumption within 72 hours postoperatively, nonopioid analgesic use within 24 and 72 hours postoperatively, time to rescue analgesic use, and postoperative length of stay (LOS). RESULTS: A total of 326 patients were included in the matched cohort. Median 24-hour opioid consumption was significantly lower in the IRB group compared with the LB group (81 mg [30, 153] vs 103 mg [46, 241]; P = 0.01). Patients receiving IRB compared with LB also had a decrease in total opioid consumption 72 hours postoperatively (110 mg [45, 258] vs 165 mg [68, 402]; P = 0.005) and shorter postoperative LOS (2.8 days [1.7, 4] vs 3.3 days [2, 5.1]; P < 0.001). There was no difference in time to rescue analgesic use. CONCLUSION AND RELEVANCE: Across a variety of surgical procedures, administration of IRB compared with LB was associated with a reduction in total opioid consumption within 24 and 72 hours postoperatively and shorter LOS in adult surgical patients.

Solitary Bone Plasmacytoma of Humerus Presenting as a Nonhealing Fracture in a Child: A Rare Entity.

Solitary bone plasmacytoma is an extremely rare entity and is characterized by localized proliferation of monoclonal plasma cells. Plasmacytomas are extremely rare in the pediatric population. The median age at diagnosis is usually the fifth or sixth decade, with axial skeleton being more commonly involved than appendicular. We hereby, report the case of a 13-year-old boy with solitary bone plasmacytoma of the right humerus. Though extremely rare in the pediatric age group, plasmacytomas may be considered as one of the remote differentials in children presenting with solitary bone tumors.

Clinicopathologic Profile and Treatment Outcomes of Children With Diffuse Large B-cell Lymphomas: Experience From a Tertiary Cancer Center in India.

Clinicopathologic profile and outcome of 15 children (15 years or above) with diffuse large B-cell lymphoma treated with MCP-842 protocol are reported. Eleven of 15 presented with advanced (stage-III/IV) disease. Post-2 cycles of chemotherapy, complete metabolic and morphologic response was documented in 10 (66%) and rest 5 (33%) with partial response achieved complete metabolic remission by end of treatment. At a median follow-up of 44 months (range: 16 to 79 mo), the 3-year event-free survival and overall-survival were 77.1%±11.7% and 85.7%±9.4%, respectively. Though majority of our patients had advanced disease, outcome on MCP-842 protocol was satisfactory.

Clinical outcomes and prognostic factors in children with B-cell lymphoblastic lymphoma (LBL) treated according to on modified BFM-90 protocol: Experience from a Tertiary cancer care center in India.

Pediatric B-cell lymphoblastic lymphoma (LBL) is a rare entity, and appropriate treatment for pediatric B-cell LBL is not well defined. While intensive ALL type regimens achieve long term survival of 90% across Western co-operative group trials, published data from Asian studies on long term outcomes are scarce. We retrospectively analyzed the data of pediatric B-cell LBL patients treated between January 2010 and December 2017 on a uniform protocol (modified BFM 90). Kaplan-Meier method was used to estimate the survival and Cox regression models to identify prognostic factors. Of 21 patients who received treatment on the modified BFM-90 protocol, 17(81%) were alive in remission, 3(14%) had relapse, and 1(4%) had treatment-related mortality (TRM) while in remission. Two of 3 relapsed patients subsequently expired. With a median follow-up of 66 months (range 6-114), 5-year event free survival (EFS) and overall survival (OS) were 80% (95% CI:71-89%) and 91% (95% CI:85-97%), respectively. While delayed presentation from symptom onset (p=0.030), and partial response at early (D35) interim assessment (p=0.025) had inferior EFS, patients with elevated baseline LDH had a worse OS (p=0.037). Outcomes of pediatric B-cell LBL patients treated on a modified BFM-90 protocol at a single center in India were excellent. In our study, higher disease burden manifested by elevated baseline LDH and delayed presentation (≥3months) and partial interim response portend poorer survival.Supplemental data for this article is available online at https://doi.org/10.1080/08880018.2021.2005725.

lncRNA recruits RNAi and the exosome to dynamically regulate pho1 expression in response to phosphate levels in fission yeast.

Numerous noncoding transcripts of unknown function have recently been identified. In this study, we report a novel mechanism that relies on transcription of noncoding RNA prt (pho1-repressing transcript) regulating expression of the pho1 gene. A product of this gene, Pho1, is a major secreted phosphatase needed for uptake of extracellular phosphate in fission yeast. prt is produced from the promoter located upstream of the pho1 gene in response to phosphate, and its transcription leads to deposition of RNAi-dependent H3K9me2 across the pho1 locus. In contrast, phosphate starvation leads to loss of H3K9me2 and pho1 induction. Strikingly, deletion of Clr4, a H3K9 methyltransferase, results in faster pho1 induction in response to phosphate starvation. We propose a new role for noncoding transcription in establishing transient heterochromatin to mediate an effective transcriptional response to environmental stimuli. RNAi recruitment to prt depends on the RNA-binding protein Mmi1. Importantly, we found that the exosome complex and Mmi1 are required for transcription termination and the subsequent degradation of prt but not pho1 mRNA. Moreover, in mitotic cells, transcription termination of meiotic RNAs also relies on this mechanism. We propose that exosome-dependent termination constitutes a specialized system that primes transcripts for degradation to ensure their efficient elimination.

Spliceosome-mediated decay (SMD) regulates expression of nonintronic genes in budding yeast.

We uncovered a novel role for the spliceosome in regulating mRNA expression levels that involves splicing coupled to RNA decay, which we refer to as spliceosome-mediated decay (SMD). Our transcriptome-wide studies identified numerous transcripts that are not known to have introns but are spliced by the spliceosome at canonical splice sites in Saccharomyces cerevisiae. Products of SMD are primarily degraded by the nuclear RNA surveillance machinery. We demonstrate that SMD can significantly down-regulate mRNA levels; splicing at canonical splice sites in the bromodomain factor 2 (BDF2) transcript reduced transcript levels roughly threefold by generating unstable products that are rapidly degraded by the nuclear surveillance machinery. Regulation of BDF2 mRNA levels by SMD requires Bdf1, a functionally redundant Bdf2 paralog that plays a role in recruiting the spliceosome to the BDF2 mRNA. Interestingly, mutating BDF2 5' splice site and branch point consensus sequences partially suppresses the bdf1Δ temperature-sensitive phenotype, suggesting that maintaining proper levels of Bdf2 via SMD is biologically important. We propose that the spliceosome can also repress protein-coding gene expression by promoting nuclear turnover of spliced RNA products and provide an insight for coordinated regulation of Bdf1 and Bdf2 levels in the cell.

Assessment of the impact of 2015 American Thyroid Association guidelines in management of differentiated thyroid cancer patients.

The 2015 American Thyroid Association (ATA) guideline have suggested modifications in the risk stratification (RS) for differentiated thyroid cancer (DTC) patients, introduced the concept of dynamic risk stratification (DRS) and redefined the role of radioactive iodine (RAI) in treatment algorithm. The aim of this retrospective audit was to assess the practical implications of these modifications in management of DTC. METHODS: A total of 138 DTC patients were stratified according to ATA 2009 and 2015 guidelines into low (LR), intermediate (IR) and high (HR) risk groups. Change in RS and in intention of RAI use was calculated. Deviation in administered RAI dosage from the guidelines was assessed. 1-year follow-up data was audited to assess how the DRS modified the initial risk estimate. RESULTS: A total of 11.6% of patients changed their RS categories in 2015 guidelines. A total of 10.1% got upstaged to HR, and 1.4% got downstaged to LR. In 2.17% of patients' intention of RAI use changed to remnant ablation from adjuvant therapy and 65% of the LR patients won't require any RAI therapy. A total of 26.7% of patients had received significantly more RAI dosage according to ATA 2015. At 1-year follow-up according to DRS 84% of LR, 75% of IR and 44% of HR patients showed excellent response (ER). CONCLUSION: More patients changed RS to HR than to LR. Intention of RAI use changed in only a small number of patients. Significantly higher dosage of RAI is being administered to patients in current practice. The effect of DRS in modifying the initial RS was most prominent in IR, with most showing ER to initial therapy.

Clinical profile and outcome of classical Hodgkin lymphoma treated with a risk-adapted approach in a tertiary cancer center in India.

BACKGROUND: Classical Hodgkin lymphoma (cHL) has excellent survival rates, but late effects are an issue and dictate modern approaches. We analyzed the clinical profile and outcome of cHL treated on a risk-adapted approach aimed at reducing late effects while improving historical outcomes at our center. PROCEDURE: Children (≤15 years) consecutively treated for cHL from January 2013 through December 2016 were retrospectively analyzed. 18 FDG-PET-CT-based staging and response assessment was done after two cycles for early response (ERA) and end of chemotherapy (late-response assessment [LRA]) if not in complete response (CR; Deauville < 4) at ERA. Stages IA/IB/IIA were low risk (LR) and received two cycles of ABVD (adriamycin/bleomycin/vinblastine/dacarbazine). Stages IAX/IBX/IIAX/IIB/IIIA were intermediate risk (IR), and stages IIBE/IIBX/IIIAE/IIIAX/IIIB/IVA/IVB were high risk (HR). Both received two cycles of OEPA (oncocristine/etoposide/prednisolone/adriamycin). Those in ERA-CR received two cycles of ABVD if LR, and two and four cycles of COPDac (cyclophosphamide/oncocristine/prednisolone/dacarbazine), respectively, for IR and HR. Involved-field radiotherapy (IFRT) was given to bulky sites and ERA < CR. Those at LRA < CR (Deauville < 3) or progression at any stage received salvage regimens. RESULTS: In the study period, 126 patients were identified who received the above protocol. There were 12 LR, and 114 advanced staged Hodgkin lymphoma (AHL) (18, IR; 96, HR) of which 91 (79.8%) had bulky sites. Eight (66.6%) LR and 93 (83%) AHL patients achieved ERA-CRs. IFRT was given to 4 (33.3%) LR patients with ERA < CR, and 92 (80.7%) of AHL (91 bulky sites; 1 ERA < CR). At a median follow-up of 31 months (range, 17-62), three-year event-free survival (EFS) and overall survival (OS) were both 100% for LR, and 94.4% (95% CI, 66.0%-99.2%) for IR, whereas for HR it was 90.3% (95% CI, 82.2%-94.8%) and 92.6% (95% CI, 85.2%-96.4%), respectively. CONCLUSIONS: Children with HL have favorable outcomes with manageable toxicities when treated on a risk-stratified and adapted approach. A high proportion of AHL have bulky disease necessitating IFRT, a concern that will have to be factored in future strategies.

Outcomes with nondose-dense chemotherapy for Ewing sarcoma: A practical approach for the developing world.

BACKGROUND: The current multidisciplinary approach in the treatment of Ewing sarcoma has improved cure rates, with contemporary dose-dense chemotherapy attaining 5-year event-free survival (EFS) of 73% in localized cases. Dose-intense and dose-dense chemotherapy is difficult in the majority of resource-limited settings with limited access to optimal supportive care. We report on patients with Ewing sarcoma treated on EFT-2001, a nondose-dense chemotherapy protocol. PROCEDURE: A retrospective analysis was conducted of patients (<15 years) with Ewing sarcoma treated with curative intent during January 2013-June 2017 with an institutional ethics committee-approved nondose-dense protocol (EFT-2001). Local therapy was planned after 9-12 weeks of chemotherapy with metastatic sites addressed with radiotherapy. The study assessed outcomes and prognostic factors. RESULTS: We analysed 200 patients with M:F ratio of 1.27:1 and metastases in 41 patients (20.5%). At a median follow up of 41.5 months (range 4.5-81.8 months), respective 3-year EFS and overall survival (OS) of the whole cohort is 65.3% (95% confidence interval [CI]: 58.1-71.7%) and 79.3% (95% CI: 72.8-84.5%); for localized and metastatic cohort, 70.9% (95% CI: 62.9-77.5%) and 82.8% (95% CI: 75.7-89.0%); and for metastatic cohort, 42.8% (95% CI: 28.0-58.6%) and 65.3% (95% CI: 47.7-78.3%). Presence of residual disease (morphologic/metabolic) on positron emission tomography-computed tomography scan done 3 months post definitive radiotherapy (hazard ratio [HR] 7.92 [95% CI: 3.46-18.14]) and delay in any form of local control >4 months (HR 3.42 [95% CI: 1.32-8.89]) affected outcomes. Nonrelapse mortality during treatment was 6.5%, mainly due to cardiomyopathy (3.0%) and bacterial sepsis (1.5%). Cardiotoxicity was seen in 11.5% of patients. CONCLUSIONS: Nondose-dense chemotherapy provides good outcomes with manageable toxicities in a multidisciplinary treatment approach, while reducing cumulative drug exposures in the developing world where dose-intense or dose-dense chemotherapy could potentially increase toxicity, and hence seems a feasible approach in resource-limited settings. Presence of any residual disease post definitive radiotherapy or delay in local control portends poor outcome.

Increased toxicities in children with Burkitt lymphoma treated with rituximab: Experience from a tertiary cancer center in India.

BACKGROUND: Even though rituximab has emerged as standard of care for the management of high-risk pediatric Burkitt lymphoma (BL), its safety in children from the low-middle-income countries (LMICs) remains to be proven. We herein report our experience of using rituximab in children with BL. METHODS: All patients diagnosed with BL between January 2015 and December 2017 were treated in a risk-stratified manner with either the modified MCP-842 or modified LMB protocol. Patients with poor response to MCP-842 were switched to the LMB-salvage regimen. In addition, rituximab was given to selected high-risk patients. RESULT: Forty-two (49.4%) of 85 patients with BL received rituximab. The incidence of febrile neutropenia (90.5% vs 67.4%; P = 0.02), pneumonia (38.1% vs 11.6%; P = 0.005), intensive care unit admissions (54.5% vs 17.6%; P = 0.002), and toxic deaths (26.2% vs 9.3%; P = 0.04) was higher among BL patients who received rituximab. Pneumonia was fatal in 11 of 16 (69%) patients who received rituximab. On multivariate analysis, rituximab continued to be significantly associated with toxic deaths ( OR: 11.45 [95% CI: 1.87-70.07; P = 0.008]). The addition of rituximab to intensive chemotherapy resulted in an inferior one-year event-free survival (49.4% ± 8.1% vs 79.3% ± 6.5%; P = 0.025) and one-year overall survival (63.1% ± 8.5% vs 91.8% ± 4.5%; P = 0.007) with no improvement in one-year relapse-free survival (78.3% ± 7.3% vs 83.9% ± 6.0%; P = 0.817). CONCLUSION: Rituximab was associated with increased toxicities and toxic deaths in our patients. The potential immunomodulatory effect of rituximab and increased susceptibility to infections in patients from LMICs have to be carefully considered while choosing this drug in the treatment of BL in resource-constrained settings.

Implementation of a Pharmacist-Driven Detailed Penicillin Allergy Interview.

Background: Self-reported penicillin allergies may be outdated or inaccurate, leading to the use of alternative antimicrobials that may be less effective, more toxic, and/or more expensive. Although penicillin skin tests can provide accurate assessments of penicillin allergies, these procedures are not feasible at all institutions. Another solution is to conduct a detailed penicillin allergy interview (DPAI), which can potentially lead to optimization of antimicrobial therapy. Objective: The purpose of this study was to assess the impact of a pharmacist-driven DPAI protocol. The primary objective was to measure the number of patients requiring a change to their allergy profile following DPAI. Secondary objectives included characterizing allergy profile updates and measuring the number of recommendations to switch to a ß-lactam agent, provider acceptance rate, and patient tolerance. Methods: Standardized pharmacist-driven DPAIs were conducted prospectively on adult patients admitted with a documented penicillin allergy. The allergy profile within the electronic health record (EHR) was updated and a recommendation to switch to noncarbapenem ß-lactam therapy was made when indicated by a decision algorithm. Results: A total of 175 (37.5%) patients received a DPAI. Of these, 133 (76.0%) required a change to their allergy profile. Additionally, 135 (77.1%) patients interviewed were on antimicrobial therapy, with 42 (31.1%) meeting criteria to switch to noncarbapenem ß-lactam therapy; of which 31 (73.8%) patients were successfully transitioned, with no signs or symptoms of intolerance. Conclusions and Relevance: Implementation of pharmacist-driven DPAIs can provide updated and corrected allergy information within the EHR, allowing for de-escalation and/or optimization of antimicrobial therapy.

The 2.5 Å structure of CD1c in complex with a mycobacterial lipid reveals an open groove ideally suited for diverse antigen presentation.

CD1 molecules function to present lipid-based antigens to T cells. Here we present the crystal structure of CD1c at 2.5 Å resolution, in complex with the pathogenic Mycobacterium tuberculosis antigen mannosyl-ß1-phosphomycoketide (MPM). CD1c accommodated MPM's methylated alkyl chain exclusively in the A' pocket, aided by a unique exit portal underneath the α1 helix. Most striking was an open F' pocket architecture lacking the closed cavity structure of other CD1 molecules, reminiscent of peptide binding grooves of classical major histocompatibility complex molecules. This feature, combined with tryptophan-fluorescence quenching during loading of a dodecameric lipopeptide antigen, provides a compelling model by which both the lipid and peptide moieties of the lipopeptide are involved in CD1c presentation of lipopeptides.

Customized approach for upfront or delayed resection using radiological criteria in unilateral, nonmetastatic pediatric renal tumors: A prospective study.

BACKGROUND: The availability of robust, equivalent data regarding outcomes for upfront or delayed surgery for renal tumors in children leads to a dilemma in selecting the initial treatment. Imaging criteria associated with the probability of rupture or incomplete resection may provide a more objective assessment for customization for the timing of surgery. PROCEDURE: Eighty-three children with unilateral, nonmetastatic renal tumors were enrolled between January 2012 and April 2018. Upfront nephrectomy was performed in the absence or delayed surgery (after a biopsy and chemotherapy) in the presence of one or more imaging-based high-risk features, including perinephric spread or adjacent organ infiltration, tumors crossing the midline, intravascular thrombus, and extensive adenopathy. Post hoc analysis for interobserver concordance for high-risk imaging features was also performed. RESULTS: The upfront surgery group (19) had predominantly stage I or II diseases (89%) and the histological types were Wilms (13), non-Wilms (5) renal tumor, and an inflammatory lesion. The delayed surgery group had 60% with stage I or II diseases and the histological types were Wilms (60) and non-Wilms (4) tumor. In addition, high-risk pathology was identified in nine patients. Overall, 27 patients with Wilms tumors required radiotherapy and anthracycline because of stage III disease, including one in the immediate surgery group. The event-free and overall survival (OS) at a median follow-up of 39 months for Wilms tumor are 88% (95% confidence interval [CI]: 78.5-94.9%) and 89% (95% CI: 81.4-96.6%), 85.1% (95% CI: 73.8-93.4%) and 86.5% (95% CI: 77.4-95.8%) for the delayed, and 100% event-free survival as well as OS (P = .1) in the upfront surgery group. CONCLUSION: A customized approach pivoted on image-based high-risk features facilitates identification of patients with early-stage renal tumor when the timing of surgery is tailored. Moreover, non-Wilms tumor and high-risk pathology are also identified.

NMR line shape analysis of a multi-state ligand binding mechanism in chitosanase.

Chitosan interaction with chitosanase was examined through analysis of spectral line shapes in the NMR HSQC titration experiments. We established that the substrate, chitosan hexamer, binds to the enzyme through the three-state induced-fit mechanism with fast formation of the encounter complex followed by slow isomerization of the bound-state into the final conformation. Mapping of the chemical shift perturbations in two sequential steps of the mechanism highlighted involvement of the substrate-binding subsites and the hinge region in the binding reaction. Equilibrium parameters of the three-state model agreed with the overall thermodynamic dissociation constant determined by ITC. This study presented the first kinetic evidence of the induced-fit mechanism in the glycoside hydrolases.