Citations

ABSTRACTThe study of the interactions of subgroup A avian sarcoma and leucosis viruses [ASLV(A)] with the TVA receptor required to infect cells offers a powerful experimental model of retroviral entry. Several regions and specific residues in the TVA receptor have previously been identified to be critical determinants of the binding affinity with ASLV(A) envelope glycoproteins and to mediate efficient infection. Two homologs of the TVA receptor have been cloned: the original quail TVA receptor, which has been the basis for most of the initial characterization of the ASLV(A) TVA, and the chicken TVA receptor, which is 65% identical to the quail receptor overall but identical in the region thought to be critical for infection. Our previous work characterized three mutant ASLV(A) isolates that could efficiently bind and infect cells using the chicken TVA receptor homolog but not using the quail TVA receptor homolog, with the infectivity of one mutant virus being >500-fold less with the quail TVA receptor. The mutant viruses contained mutations in the hr1 region of the surface glycoprotein. Using chimeras of the quail and chicken TVA receptors, we have identified new residues of TVA critical for the binding affinity and entry of ASLV(A) using the mutant glycoproteins and viruses to probe the function of those residues. The quail TVA receptor required changes at residues 10, 14, and 31 of the corresponding chicken TVA residues to bind wild-type and mutant ASLV(A) glycoproteins with a high affinity and recover the ability to mediate efficient infection of cells. A model of the TVA determinants critical for interacting with ASLV(A) glycoproteins is proposed.IMPORTANCEA detailed understanding of how retroviruses enter cells, evolve to use new receptors, and maintain efficient entry is crucial for identifying new targets for combating retrovirus infection and pathogenesis, as well as for developing new approaches for targeted gene delivery. Since all retroviruses share an envelope glycoprotein organization, they likely share a mechanism of receptor triggering to begin the entry process. Multiple, noncontiguous interaction determinants located in the receptor and the surface (SU) glycoprotein hypervariable domains are required for binding affinity and to restrict or broaden receptor usage. In this study, further mechanistic details of the entry process were elucidated by characterizing the ASLV(A) glycoprotein interactions with the TVA receptor required for entry. The ASLV(A) envelope glycoproteins are organized into functional domains that allow changes in receptor choice to occur by mutation and/or recombination while maintaining a critical level of receptor binding affinity and an ability to trigger glycoprotein conformational changes.

Objectives/HypothesisFibrous dysplasia is a condition of nonmalignant osseous change and may occur in a monostotic or polyostotic pattern, the latter potentially being associated with McCune‐Albright syndrome. Symptoms are highly variable and dependent upon lesion location and size.Study DesignRetrospective review.MethodsConsecutive subjects with fibrous dysplasia of the temporal bone were evaluated between 2000 and 2013 at two tertiary academic referral centers. Main outcome measures included disease presentation, diagnostic evaluation, management strategy, and outcome.ResultsSixty‐six patients with fibrous dysplasia of the skull were found to have involvement of the temporal bone. The mean age at diagnosis was 25 years, 39 (59%) were female, and the mean duration of follow‐up was 48 months. Six (11%) patients had monostotic disease, with the remaining 60 (89%) patients having the polyostotic form; 16 (24%) patients had McCune‐Albright syndrome. The most common presenting complaint was headache (59%), followed by hearing loss (29%). The most common exam finding was cosmetic deformity (50%). Cholesteatoma (3%) and spontaneous cerebrospinal fluid fistula (1.5%) were found in a small percentage. No patients had evidence of motor cranial neuropathy by history or physical examination.ConclusionsThe clinical presentation of fibrous dysplasia involving the temporal bone is variable. A growing number of patients are diagnosed incidentally through imaging, and since most patients experience a benign course, the majority can be followed clinically without need for intervention.Level of Evidence4. Laryngoscope, 125:1438–1443, 2015

Abstract Myeloproliferative neoplasms, including polycythemia vera (PV), essential thrombocythemia, and myelofibrosis (MF) (both primary and secondary), are recognized for their burdensome symptom profiles, life-threatening complications, and risk of progression to acute leukemia. Recent advancements in our ability to diagnose and prognosticate these clonal malignancies have paralleled the development of MPN-targeted therapies that have had a significant impact on disease burden and quality of life. Ruxolitinib has shown success in alleviating the symptomatic burden, reducing splenomegaly and improving quality of life in patients with MF. The role and clinical expectations of JAK2 inhibition continues to expand to a variety of investigational arenas. Clinical trials for patients with MF focus on new JAK inhibitors with potentially less myelosuppression (pacritinib) or even activity for anemia (momelotinib). Further efforts focus on combination trials (including a JAK inhibitor base) or targeting new pathways (ie, telomerase). Similarly, therapy for PV continues to evolve with phase 3 trials investigating optimal frontline therapy (hydroxyurea or IFN) and second-line therapy for hydroxyurea-refractory or intolerant PV with JAK inhibitors. In this chapter, we review the evolving data and role of JAK inhibition (alone or in combination) in the management of patients with MPNs.

KLF10 has recently elicited significant attention as a transcriptional regulator of transforming growth factor-β1 (TGF-β1) signaling in CD4+ T cells. In the current study, we demonstrate a novel role for KLF10 in the regulation of TGF-β receptor II (TGF-βRII) expression with functional relevance in antiviral immune response. Specifically, we show that KLF10-deficient mice have an increased number of effector/memory CD8+ T cells, display higher levels of the T helper type 1 cell-associated transcription factor T-bet, and produce more IFN-γ following in vitro stimulation. In addition, KLF10−/− CD8+ T cells show enhanced proliferation in vitro and homeostatic proliferation in vivo. Freshly isolated CD8+ T cells from the spleen of adult mice express lower levels of surface TGF-βRII (TβRII). Congruently, in vitro activation of KLF10-deficient CD8+ T cells upregulate TGF-βRII to a lesser extent compared with wild-type (WT) CD8+ T cells, which results in attenuated Smad2 phosphorylation following TGF-β1 stimulation compared with WT CD8+ T cells. Moreover, we demonstrate that KLF10 directly binds to the TGF-βRII promoter in T cells, leading to enhanced gene expression. In vivo viral infection with Daniel's strain Theiler's murine encephalomyelitis virus (TMEV) also led to lower expression of TGF-βRII among viral-specific KLF10−/− CD8+ T cells and a higher percentage of IFN-γ-producing CD8+ T cells in the spleen. Collectively, our data reveal a critical role for KLF10 in the transcriptional activation of TGF-βRII in CD8+ T cells. Thus, KLF10 regulation of TGF-βRII in this cell subset may likely play a critical role in viral and tumor immune responses for which the integrity of the TGF-β1/TGF-βRII signaling pathway is crucial.

Decoding stem cell metabolism has implicated a tight linkage between energy metabolism and cell fate regulation, a dynamic interplay vital in the execution of developmental and differentiation programs. The inherent plasticity in energy metabolism enables prioritisation of metabolic pathways in support of stage-specific demands. Beyond traditional support of energetic needs, intermediate metabolism may also dictate cell fate choices through regulation of cellular signalling and epigenetic regulation of gene expression. The notion of a ‘metabolism-centric’ control of stem cell differentiation has been informed by developmental embryogenesis based upon an on-demand paradigm paramount in defining diverse developmental behaviours, from a post-fertilisation nascent zygote to complex organogenesis leading to adequate tissue formation and maturation. Monitored through natural or bioengineered stem cell surrogates, nutrient-responsive metabolites are identified as mediators of cross-talk between metabolic flux, cell signalling and epigenetic regulation charting, collectively, whether a cell will self-renew to maintain progenitor pools, lineage specify to ensure tissue (re)generation or remain quiescent to curb stress damage. Thus, bioenergetics are increasingly recognised as integral in governing stemness and associated organogenic decisions, paving the way for metabolism-defined targets in control of embryology, stem cell biology and tissue regeneration.

AbstractBackgroundHuman factors research has suggested benefits of consistent teams yet no surgical team consistency measures have been established for teamwork improvement initiatives.MethodsRetrospective analysis was conducted of teams performing consecutive elective procedures of unilateral primary total knee and hip replacement between June 2008 and May 2010 at a large tertiary medical center. Surgeons who performed fewer than 50 cases of the procedures during the study period were excluded. A team was defined as consistent when its nurse and surgical technologist members were both among the three most frequent working with the surgeon during the study period. Odds ratios for prolonged operative time (in the longest quartile), prolonged hospital stay (longer than median), and 30‐day all‐cause readmissions were adjusted for patient characteristics (sex, age, comorbidity, American Society of Anesthesiology status), surgery characteristics (procedures, time of day), and surgeons.ResultsInconsistent teams performed 61 % of the 1,923 cases with eight surgeons, each of which worked with a median of 43.5 (range, 28–58) nurses and 29 (range, 13–47) technologists. Inconsistent teams were associated with higher likelihood of prolonged operative time [odds ratio 1.52, 95 % confidence interval (CI) 1.20–1.91], higher likelihood of prolonged hospital stay (odds ratio 1.51, 95 % CI 1.23–1.86), and more readmissions (adjusted odds ratio 1.42, 95 % CI 1.07–1.89).ConclusionsTeam consistency was an independent predictor of prolonged operative time, prolonged hospital stay, and 30‐day hospital readmission in elective, primary, unilateral total knee, and hip replacement procedures, after adjusting for patient and surgery characteristics and surgeons.

Background:Bronchial brush (BB) cytology carries low sensitivity for detecting neuroendocrine carcinomas (NECs), including typical carcinoid (TC) tumors of the lung. We aimed to investigate the detection of neuroendocrine tumors including TC through BB routine cytology cell block (CB), immunohistochemistry (IHC), and fluorescencein situhybridization (FISH).Materials and Methods:A SNOMED search showed 187 lung biopsy or resection specimens from 2008 through 2011 containing neuroendocrine or carcinoid in the diagnosis. Residual BB specimens retained in PreservCyt were used to prepare a ThinPrep slide for FISH analysis. CBs were stained with H and E and IHC for chromogranin and synaptophysin.Results:Of the 187 cases, 16 had residual BB material available within 1 year of diagnosis and were used in CB preparation for IHC and FISH slides. Cytologic evaluation determined 1 case positive for malignancy (small cell lung carcinoma [SCLC]), 1 suspicious for adenocarcinoma, and 14 negative for malignancy. On the basis of histologic diagnosis, FISH was performed. SCLC showed polysomy (86% abnormal cells); 2 TC tumors showed a gain of 7p12 (15% abnormal cells) and a gain of 5q15 (72% abnormal cells), respectively. Two cases had CBs with positive immunoreactivity for chromogranin and synaptophysin. The sensitivity for detection of NEC was 18.8%, 15.4%, and 25% for cytologic evaluation, CB, and FISH, respectively.Conclusion:Neuroendocrine tumors, including TC are difficult to detect with BB cytologic evaluation, most likely because tumor cells lack in the specimen. Assessment of further studies is needed to explore the role of cytology and ancillary methods for detection of these tumors.