Ribosomal protein control of hematopoietic stem cell transformation through direct, non-canonical regulation of metabolism.

We report here that expression of the ribosomal protein, RPL22, is frequently reduced in human myelodysplastic syndrome (MDS) and acute myelogenous leukemia (AML); reduced RPL22 expression is associated with worse outcomes. Mice null for Rpl22 display characteristics of an MDS-like syndrome and develop leukemia at an accelerated rate. Rpl22-deficient mice also display enhanced hematopoietic stem cell (HSC) self-renewal and obstructed differentiation potential, which arises not from reduced protein synthesis but from increased expression of the Rpl22 target, ALOX12, an upstream regulator of fatty acid oxidation (FAO). The increased FAO mediated by Rpl22-deficiency also persists in leukemia cells and promotes their survival. Altogether, these findings reveal that Rpl22 insufficiency enhances the leukemia potential of HSC via non-canonical de-repression of its target, ALOX12, which enhances FAO, a process that may serve as a therapeutic vulnerability of Rpl22 low MDS and AML leukemia cells. Highlights: RPL22 insufficiency is observed in MDS/AML and is associated with reduced survivalRpl22-deficiency produces an MDS-like syndrome and facilitates leukemogenesisRpl22-deficiency does not impair global protein synthesis by HSCRpl22 controls leukemia cell survival by non-canonical regulation of lipid oxidation eTOC: Rpl22 controls the function and transformation potential of hematopoietic stem cells through effects on ALOX12 expression, a regulator of fatty acid oxidation.

Loss of Ribosomal Protein Paralog Rpl22-like1 Blocks Lymphoid Development without Affecting Protein Synthesis.

Ribosomal proteins are thought to primarily facilitate biogenesis of the ribosome and its ability to synthesize protein. However, in this study, we show that Rpl22-like1 (Rpl22l1) regulates hematopoiesis without affecting ribosome biogenesis or bulk protein synthesis. Conditional loss of murine Rpl22l1 using stage or lineage-restricted Cre drivers impairs development of several hematopoietic lineages. Specifically, Tie2-Cre-mediated ablation of Rpl22l1 in hemogenic endothelium impairs the emergence of embryonic hematopoietic stem cells. Ablation of Rpl22l1 in late fetal liver progenitors impairs the development of B lineage progenitors at the pre-B stage and development of T cells at the CD44-CD25+ double-negative stage. In vivo labeling with O-propargyl-puromycin revealed that protein synthesis at the stages of arrest was not altered, indicating that the ribosome biogenesis and function were not generally compromised. The developmental arrest was associated with p53 activation, suggesting that the arrest may be p53-dependent. Indeed, development of both B and T lymphocytes was rescued by p53 deficiency. p53 induction was not accompanied by DNA damage as indicated by phospho-γH2AX induction or endoplasmic reticulum stress, as measured by phosphorylation of EIF2α, thereby excluding the known likely p53 inducers as causal. Finally, the developmental arrest of T cells was not rescued by elimination of the Rpl22l1 paralog, Rpl22, as we had previously found for the emergence of hematopoietic stem cells. This indicates that Rpl22 and Rpl22l1 play distinct and essential roles in supporting B and T cell development.

RPL22L1 induction in colorectal cancer is associated with poor prognosis and 5-FU resistance.

We have previously demonstrated that loss of the tumor suppressive activity of ribosomal protein (RP) RPL22 predisposes to development of leukemia in mouse models and aggressive disease in human patients; however, the role of RPL22 in solid tumors, specifically colorectal cancer (CRC), had not been explored. We report here that RPL22 is either deleted or mutated in 36% of CRC and provide new insights into its mechanism of action. Indeed, Rpl22 inactivation causes the induction of its highly homologous paralog, RPL22L1, which serves as a driver of cell proliferation and anchorage-independent growth in CRC cells. Moreover, RPL22L1 protein is highly expressed in patient CRC samples and correlates with poor survival. Interestingly, the association of high RPL22L1 expression with poor prognosis appears to be linked to resistance to 5-Fluorouracil, which is a core component of most CRC therapeutic regimens. Indeed, in an avatar trial, we found that human CRC samples that were unresponsive to 5-Fluorouracil in patient-derived xenografts exhibited elevated expression levels of RPL22L1. This link between RPL22L1 induction and 5-Fluorouracil resistance appears to be causal, because ectopic expression or knockdown of RPL22L1 in cell lines increases and decreases 5-Fluorouracil resistance, respectively, and this is associated with changes in expression of the DNA-repair genes, MGMT and MLH1. In summary, our data suggest that RPL22L1 might be a prognostic marker in CRC and predict 5-FU responsiveness.

Reducing Inappropriate Testing for the Evaluation of Diarrhea Among Hospitalized Patients.

BACKGROUND: Diarrhea is one of the most common illnesses in the United States. Evaluation frequently does not follow established guidelines. The objective of this study was to evaluate the effectiveness of a computerized physician order entry-based test guidance algorithm with regard to the clinical, financial, and operational impacts. METHODS: Our population was patients with diarrheal illness at a tertiary academic medical center. The intervention was a computerized physician order entry-based test guidance algorithm that restricted the use of stool cultures and ova and parasites testing of diarrhea in the adult inpatient location vs nonintervention sites, which were the emergency department, pediatric inpatient and adult and pediatric outpatient locations. We measured stool culture, ova and parasites, and Clostridium difficile testing rates from July 1, 2012 to January 31, 2016. Additionally, we calculated advisor usage, consults generated, accuracy of information, and cost savings. RESULTS: There was a significant decrease in stool culture and ova and parasites testing rates at the adult inpatient (P = .001 for both), pediatric (P < .001 for both), and adult emergency department (P < .001; P = .009) locations. The decrease at the intervention site was immediate, whereas the other locations showed a delayed but sustained decrease that suggests a collateral impact. A significant increase in the rate of stool culture and ova and parasites testing was observed in the outpatient setting (P = .02 and P = .001). We estimate that $21,931 was saved annually. CONCLUSIONS: A point-of-order test restriction algorithm for hospitalized adults with diarrhea reduced stool testing. Similar programs should be considered at other institutions and for the evaluation of other conditions.

Creation of a 3-dimensional virtual dental patient for computer-guided surgery and CAD-CAM interim complete removable and fixed dental prostheses: A clinical report.

This clinical report proposes a digital workflow using 2-dimensional (2D) digital photographs, a 3D extraoral facial scan, and cone beam computed tomography (CBCT) volumetric data to create a 3D virtual patient with craniofacial hard tissue, remaining dentition (including surrounding intraoral soft tissue), and the realistic appearance of facial soft tissue at an exaggerated smile under static conditions. The 3D virtual patient was used to assist the virtual diagnostic tooth arrangement process, providing patient with a pleasing preoperative virtual smile design that harmonized with facial features. The 3D virtual patient was also used to gain patient's pretreatment approval (as a communication tool), design a prosthetically driven surgical plan for computer-guided implant surgery, and fabricate the computer-aided design and computer-aided manufacturing (CAD-CAM) interim prostheses.

Cone beam computed tomography imaging as a primary diagnostic tool for computer-guided surgery and CAD-CAM interim removable and fixed dental prostheses.

This article describes a digital workflow using cone beam computed tomography imaging as the primary diagnostic tool in the virtual planning of the computer-guided surgery and fabrication of a maxillary interim complete removable dental prosthesis and mandibular interim implant-supported complete fixed dental prosthesis with computer-aided design and computer-aided manufacturing technology. Diagnostic impressions (conventional or digital) and casts are unnecessary in this proposed digital workflow, providing clinicians with an alternative treatment in the indicated clinical scenario.

Digital approach to planning computer-guided surgery and immediate provisionalization in a partially edentulous patient.

This report describes a digital approach for computer-guided surgery and immediate provisionalization in a partially edentulous patient. With diagnostic data obtained from cone-beam computed tomography and intraoral digital diagnostic scans, a digital pathway of virtual diagnostic waxing, a virtual prosthetically driven surgical plan, a computer-aided design and computer-aided manufacturing (CAD/CAM) surgical template, and implant-supported screw-retained interim restorations were realized with various open-architecture CAD/CAM systems. The optional CAD/CAM diagnostic casts with planned implant placement were also additively manufactured to facilitate preoperative inspection of the surgical template and customization of the CAD/CAM-fabricated interim restorations.

Maxillary and mandibular immediately loaded implant-supported interim complete fixed dental prostheses on immediately placed dental implants with a digital approach: A clinical report.

This clinical report describes the treatment of maxillary and mandibular immediate implant placement and immediately loaded implant-supported interim complete fixed dental prostheses with a contemporary digital approach. The virtual diagnostic tooth arrangement eliminated the need for a customized radiographic template, and the diagnostic data collection required for computer-guided surgery (digital diagnostic impressions, digital photographs, and a cone beam-computed tomography [CBCT] scan) was completed in a single visit with improved workflow efficiency. Computer-aided design and computer-aided manufacturing (CAD/CAM)-fabricated surgical templates and interim prosthesis templates were made in a dental laboratory to facilitate computer-guided surgery and the immediate loading process.

Rpl22 Loss Impairs the Development of B Lymphocytes by Activating a p53-Dependent Checkpoint.

Although ribosomal proteins facilitate the ribosome's core function of translation, emerging evidence suggests that some ribosomal proteins are also capable of performing tissue-restricted functions either from within specialized ribosomes or from outside of the ribosome. In particular, we have previously demonstrated that germline ablation of the gene encoding ribosomal protein Rpl22 causes a selective and p53-dependent arrest of ab T cell progenitors at the b-selection checkpoint. We have now identified a crucial role for Rpl22 during early B cell development. Germline ablation of Rpl22 results in a reduction in the absolute number of B-lineage progenitors in the bone marrow beginning at the pro­B cell stage. Although Rpl22-deficient pro­B cells are hyporesponsive to IL-7, a key cytokine required for early B cell development, the arrest of B cell development does not result from disrupted IL-7 signaling. Instead, p53 induction appears to be responsible for the developmental defects, as Rpl22 deficiency causes increased expression of p53 and activation of downstream p53 target genes, and p53 deficiency rescues the defect in B cell development in Rpl22-deficient mice. Interestingly, the requirement for Rpl22 in the B cell lineage appears to be developmentally restricted, because Rpl22-deficient splenic B cells proliferate normally in response to Ag receptor and Toll receptor stimuli and undergo normal class-switch recombination. These results indicate that Rpl22 performs a critical, developmentally restricted role in supporting early B cell development by preventing p53 induction.

Application of digital diagnostic impression, virtual planning, and computer-guided implant surgery for a CAD/CAM-fabricated, implant-supported fixed dental prosthesis: a clinical report.

This clinical report demonstrated the use of an implant-supported fixed dental prosthesis fabricated with a contemporary digital approach. The digital diagnostic data acquisition was completed with a digital diagnostic impression with an intraoral scanner and cone-beam computed tomography with a prefabricated universal radiographic template to design a virtual prosthetically driven implant surgical plan. A surgical template fabricated with computer-aided design and computer-aided manufacturing (CAD/CAM) was used to perform computer-guided implant surgery. The definitive digital data were then used to design the definitive CAD/CAM-fabricated fixed dental prosthesis.

Treatment of a maxillary central incisor with class III invasive cervical resorption and compromised ferrule: a clinical report.

This clinical report presents the treatment of a maxillary central incisor with class III invasive cervical resorption and a compromised ferrule. Nonsurgical endodontic therapy combined with periodontal surgery was provided for debridement. Direct light-polymerizing resin-modified glass ionomer cement and a zirconia crown were used to repair the defect. Symptomatic endodontic complication was diagnosed with localized cone beam computed tomography at 6-month follow-up, and periapical microsurgery was rendered. The patient was followed-up for 30 months after treatment and had no further complications.

Comparison of restoratively projected and surgically acceptable virtual implant position for mandibular overdentures.

PURPOSE: To compare differences between restoratively projected and surgically acceptable virtual implant positions at sites identified by cylindric radiopaque markers on diagnostic templates for implant-retained mandibular overdentures using cone beam computed tomography (CBCT). MATERIALS AND METHODS: A retrospective chart audit of a CBCT database identified 77 subjects who had been imaged to assess the residual alveolar ridge in the completely edentulous mandible prior to implant placement for mandibular overdentures. Individuals had been scanned with a diagnostic template using cylindric markers to identify the restoratively derived locations and trajectories for implants. Qualitative and quantitative differences between restoratively projected and surgically acceptable positions on transaxial CBCT images were recorded using implant planning software based on a standard implant. RESULTS: Only 6.4% of restoratively projected positions were within the criteria for surgically acceptable implant placement. However, most implant placement plans (77.9%) could be modified to fulfill surgically acceptable criteria. Of the projected implant positions, 15.7% were deemed inadvisable because of potential anatomical complications. Restoratively projected implant position was more likely to deviate buccally than lingually to the available residual alveolar ridge, as determined by CBCT. The mean angular deviation of the clinical prediction from ideal was 14.0 ± 5.5 degrees, the mean platform translation was 2.1 ± 1.3 mm, and the mean apex translation was 2.3 ± 1.5 mm. The average residual alveolar ridge reduction required in the posterior segment was 3.9 ± 2.5 mm. CONCLUSION: The restoratively projected trajectory for implant placement determined by visual inspection, diagnostic casts, and panoramic radiography deviated from the surgically acceptable location determined using CBCT data sets.

Cardiac medications are not associated with clinically important preoperative electrolyte disturbances in children presenting for cardiac surgery.

BACKGROUND: Preoperative laboratory examination of patients undergoing elective surgical procedures has been routinely performed for decades. Although there is a large body of literature concerning the appropriate preoperative assessment of adult patients, corresponding literature for the pediatric population is not as well defined. Children and young adults with cardiac disease are a particularly vulnerable subset of patients who often undergo an extensive battery of preoperative laboratory testing. We examined the serum chemistry profiles for children with cardiac disease presenting for outpatient surgery. The investigation aims to define the effectiveness of preoperative electrolyte determination in this population of children and young adults. METHODS: A retrospective chart review of all children presenting as outpatients to a tertiary care, freestanding children's hospital for elective cardiac surgery between January 1, 2000 and January 31, 2003 was performed. All patient charts in which the admission date matched the cardiac surgical date were examined. Patients were excluded if the preoperative laboratory evaluation was performed outside of our facility, preoperative laboratory investigation was not performed, or the patient was transported by medical transport to our hospital. Patients were grouped according to three methods: the number of cardiac medications (none to four), and cardiac medications, noncardiac medications, and no medications. The presence of electrolyte abnormalities was also examined in the context of cardiac medications with various pharmacologic effects. The primary outcome measure was the incidence of abnormal laboratory values for children taking various cardiac medications. RESULTS: Of the 933 initial entries found, 774 met the investigational criteria and were included in the analysis. Although statistically significant differences in preoperative electrolytes were associated with the use of cardiac and noncardiac medication, there was no clinical value to this correlation. The data demonstrate a very low incidence of hypokalemia and hypomagnesemia in the entire study population. CONCLUSION: Preoperative electrolyte disturbances in children and young adults presenting for cardiac surgery are uncommon. The concern of hypokalemia or hypomagnesemia important in the adult population taking cardiac medications was not identified in the pediatric population. These data do not support the need for routine preoperative electrolyte evaluation in children taking cardiac medications.