Evaluating the prognostic potential of the Ki67 proliferation index and tumour-infiltrating lymphocytes in olfactory neuroblastoma.

AIMS: Olfactory neuroblastomas (ONBs) are rare malignant tumours that arise in the nasal vault. To date, the Hyams grade remains the only widely used histological grading system. However, it is based only on morphological criteria, and has not been updated since 1988. The objective of this study was to explore the prognostic potential of the Ki67 proliferation index (PI) and tumour-infiltrating lymphocytes (TILs) in ONB. METHODS AND RESULTS: A retrospective study was conducted on a bicentric series of 45 cases. The Ki67 PI was determined by counting at least 1000 nuclei on whole slides. TILs were evaluated with CD20, CD4 and CD8 immunohistochemical markers on whole slides. In this series, Hyams grades I, II, III and IV accounted for 13.4%, 44.4%, 20% and 22.2% of all cases, respectively. The Ki67 PI ranged from 1 to 93; the Ki67 PI was significantly higher in Hyams grade III-IV ONBs than in Hyams grade I-II ONBs (P < 0.0001). A Ki67 PI of ≥25 was associated with poorer survival (P = 0.02). TILs were present in both stromal and intratumoral compartments, but were located predominantly in the stromal component of the tumour. The numbers of intratumoral CD8+ cells/mm2 and CD4+ cells/mm2 were greater in high-grade ONBs than in low-grade ONBs (P = 0.0015 and P = 0.043, respectively). The numbers of T cells/mm2 and B cells/mm2 were not associated with survival, but a CD4/CD8 ratio of >2 was significantly associated with shorter survival (P = 0.04). CONCLUSION: Our findings suggest that the Ki67 PI and TILs could be used as prognostic markers, as a potential alternative to the Hyams grade.

Integrated Multi-omic Analysis of Esthesioneuroblastomas Identifies Two Subgroups Linked to Cell Ontogeny.

Esthesioneuroblastoma (ENB) is a rare cancer of the olfactory mucosa, with no established molecular stratification to date. We report similarities of ENB with tumors arising in the neural crest and perform integrative analysis of these tumors. We propose a molecular-based subtype classification of ENB as basal or neural, both of which have distinct pathological, transcriptomic, proteomic, and immune features. Among the basal subtype, we uncovered an IDH2 R172 mutant-enriched subgroup (∼35%) harboring a CpG island methylator phenotype reminiscent of IDH2 mutant gliomas. Compared with the basal ENB methylome, the neural ENB methylome shows genome-wide reprogramming with loss of DNA methylation at the enhancers of axonal guidance genes. Our study reveals insights into the molecular pathogenesis of ENB and provides classification information of potential therapeutic relevance.

Otogenic Temporomandibular Arthritis in Children.

Importance: Septic arthritis of the temporomandibular joint (SATMJ) is a very rare but potentially severe complication of pediatric middle ear infections because it presents risks of TMJ ankylosis. Objective: To describe the clinical, radiological, biological, and microbiological characteristics and evolution of SATMJ complicating middle ear infections (otogenic SATMJ) in children. Design, Setting, and Participants: This multicenter retrospective study included all children younger than 18 years referred between January 1, 2005, and December 31, 2015, for otogenic SATMJ or for TMJ ankylosis that occurred a few months to a few years after an acute mastoiditis. Nine children were included in the study. Review of the children's medical charts was conducted from February 1, 2016, to April 1, 2016. Main Outcomes and Measures: Patients' demographic characteristics and symptoms; radiological, biological, and bacteriological findings, including reanalysis of initial imaging; and treatment and outcome of SATMJ. Results: Of the 9 children, 6 were boys and 3 were girls; the mean age was 2.1 years (range, 6 months to 4.7 years). In 7 cases (78%), the primary middle ear infection was acute mastoiditis. Clinically, 5 children (55%) had preauricular swelling and only 1 (11%) had trismus. Associated thrombophlebitis of the lateral sinus or intracranial collections was present in 7 cases (78%). An initial computed tomographic scan was performed for all but 1 patient, and second-line analysis detected clear signs of TMJ inflammation in all 8 children who had a computed tomographic scan. However, SATMJ was diagnosed in only 3 cases at the time of the initial middle ear infection, leading to the recommendation of TMJ physical therapy for several months. The most frequently involved bacteria was Fusobacterium necrophorum, which was found in 4 cases. Long-term ankylosis was identified in 6 cases (67%), and 5 of these children required surgical treatment. Conclusions and Relevance: Clinicians and radiologists must thoroughly look for signs of SATMJ in children with acute mastoiditis to detect this complication, which can lead to disabling and hard-to-treat TMJ ankylosis.

Transcriptome-Wide Mapping of RNA 5-Methylcytosine in Arabidopsis mRNAs and Noncoding RNAs.

Posttranscriptional methylation of RNA cytosine residues to 5-methylcytosine (m5C) is an important modification with diverse roles, such as regulating stress responses, stem cell proliferation, and RNA metabolism. Here, we used RNA bisulfite sequencing for transcriptome-wide quantitative mapping of m5C in the model plant Arabidopsis thaliana We discovered more than a thousand m5C sites in Arabidopsis mRNAs, long noncoding RNAs, and other noncoding RNAs across three tissue types (siliques, seedling shoots, and roots) and validated a number of these sites. Quantitative differences in methylated sites between these three tissues suggest tissue-specific regulation of m5C. Perturbing the RNA m5C methyltransferase TRM4B resulted in the loss of m5C sites on mRNAs and noncoding RNAs and reduced the stability of tRNAAsp(GTC) We also demonstrate the importance of m5C in plant development, as trm4b mutants have shorter primary roots than the wild type due to reduced cell division in the root apical meristem. In addition, trm4b mutants show increased sensitivity to oxidative stress. Finally, we provide insights into the targeting mechanism of TRM4B by demonstrating that a 50-nucleotide sequence flanking m5C C3349 in MAIGO5 mRNA is sufficient to confer methylation of a transgene reporter in Nicotiana benthamiana.

Deciphering the epitranscriptome: A green perspective.

The advent of high-throughput sequencing technologies coupled with new detection methods of RNA modifications has enabled investigation of a new layer of gene regulation - the epitranscriptome. With over 100 known RNA modifications, understanding the repertoire of RNA modifications is a huge undertaking. This review summarizes what is known about RNA modifications with an emphasis on discoveries in plants. RNA ribose modifications, base methylations and pseudouridylation are required for normal development in Arabidopsis, as mutations in the enzymes modifying them have diverse effects on plant development and stress responses. These modifications can regulate RNA structure, turnover and translation. Transfer RNA and ribosomal RNA modifications have been mapped extensively and their functions investigated in many organisms, including plants. Recent work exploring the locations, functions and targeting of N6 -methyladenosine (m6 A), 5-methylcytosine (m5 C), pseudouridine (Ψ), and additional modifications in mRNAs and ncRNAs are highlighted, as well as those previously known on tRNAs and rRNAs. Many questions remain as to the exact mechanisms of targeting and functions of specific modified sites and whether these modifications have distinct functions in the different classes of RNAs.

A Pilot Comparison of 18F-fluorocholine PET/CT, Ultrasonography and 123I/99mTc-sestaMIBI Dual-Phase Dual-Isotope Scintigraphy in the Preoperative Localization of Hyperfunctioning Parathyroid Glands in Primary or Secondary Hyperparathyroidism: Influence of Thyroid Anomalies.

We compared (18)F-fluorocholine hybrid positron emission tomography/X-ray computed tomography (FCH-PET/CT) with ultrasonography (US) and scintigraphy in patients with hyperparathyroidism and discordant, or equivocal results of US and (123)I/(99m)Tc-sesta-methoxyisobutylisonitrile (sestaMIBI) dual-phase parathyroid scintigraphy. FCH-PET/CT was performed in 17 patients with primary (n = 11) lithium induced (n = 1) or secondary hyperparathyroidism (1 dialyzed, 4 renal-transplanted).The reference standard was based on results of surgical exploration and histopathological examination. The results of imaging modalities were evaluated, on site and by masked reading, on per-patient and per-lesion bases.In a first approach, equivocal images/foci were considered as negative. On a per-patient level, the sensitivity was for US 38%, for scintigraphy 69% by open and 94% by masked reading, and for FCH-PET/CT 88% by open and 94% by masked reading. On a per-lesion level, sensitivity was for US 42%, for scintigraphy 58% by open and 83% by masked reading, and for FCH-PET/CT 88% by open and 96% by masked reading. One ectopic adenoma was missed by the 3 imaging modalities. Considering equivocal images/foci as positive increased the accuracy of the open reading of scintigraphy or of FCH-PET/CT, but not of US. FCH-PET/CT was significantly superior to US in all approaches, whereas it was more sensitive than scintigraphy only for open reading considering equivocal images/foci as negative (P = 0.04). FCH uptake was more intense in adenomas than in hyperplastic parathyroid glands. Thyroid lesions were suspected in 9 patients. They may induce false-positive results as in one case of oncocytic thyroid adenoma, or false-negative results as in one case of intrathyroidal parathyroid adenoma. Thyroid cancer (4 cases) can be visualized with FCH as with (99m)Tc-sestaMIBI, but the intensity of uptake was moderate, similar to that of parathyroid hyperplasia.This pilot study confirmed that FCH-PET/CT is an adequate imaging tool in patients with primary or secondary hyperparathyroidism, since both adenomas and hyperplastic parathyroid glands can be detected. The sensitivity of FCH-PET/CT was better than that of US and was not inferior to that of dual-phase dual-isotope (123)I/(99m)Tc-scintigraphy. Further studies should evaluate whether FCH could replace (99m)Tc-sestaMIBI as the functional agent for parathyroid imaging, but US would still be useful to identify thyroid lesions.

Is 18F-fluorocholine-positron emission tomography/computerized tomography a new imaging tool for detecting hyperfunctioning parathyroid glands in primary or secondary hyperparathyroidism?

CONTEXT: Preoperative ultrasonography and scintigraphy using (99m)Tc-sestamibi are commonly used to localize abnormal parathyroid glands. In cases of discrepant results between scintigraphy and ultrasonography, it is important to rely on another diagnostic imaging modality. (18)F-fluorodeoxyglucose (FDG) and (11)C-methionine positron emission tomography (PET) have been studied, but are imperfect to detect abnormal parathyroid glands. Recently, first cases of abnormal parathyroid glands taking-up radiolabelled choline were discovered incidentally in men referred to (11)C-choline or (18)F-fluorocholine (FCH)-PET/CT for prostate cancer. We checked if FCH uptake was a general feature of adenomatous or hyperplastic parathyroid glands. METHODS: FCH-PET/CT was performed in 12 patients with primary (n = 8) or secondary hyperparathyroidism (1 dialyzed, 3 grafted) and with discordant or equivocal results on preoperative ultrasonography (US) and/or (123)I/(99m)Tc-sestamibi dual-phase scintigraphy. The results of the FCH-PET/CT were evaluated, with surgical exploration and histopathologic examination as the standard of truth. RESULTS: On a per-patient level, the detection rate of FCH-PET/CT (at least one FCH focus corresponding to an abnormal parathyroid gland in a given patient) was 11/12 = 92%. FCH-PET/CT detected 18 foci interpreted as parathyroid glands and correctly localized 17 abnormal parathyroid glands (7 adenomas and 10 hyperplasias). On a per-lesion level, FCH-PET/CT results were 17 TP, 2 false negative ie, a lesion-based sensitivity of 89%, and 1 false positive. CONCLUSION: As the main result of this pilot study, we show that in patients with hyperparathyroidism and with discordant or equivocal results on scintigraphy or on ultrasonography, adenomatous or hyperplastic parathyroid glands can be localized by FCH-PET/CT with good accuracy. Furthermore, FCH-PET/CT can solve discrepant results between preoperative ultrasonography and scintigraphy and has thus a potential as a functional imaging modality in the detection of abnormal parathyroid glands. Our preliminary results are encouraging and prompt us to further evaluate FCH-PET/CT as a functional imaging agent in patients with biochemical hyperparathyroidism.