Electrostatic wipes as simple and reliable methods for influenza virus airborne detection

The performance of an in-house protocol for virus detection on commercialized electrostatic wipes (EWs) was assessed experimentally by impregnating them with suspensions of cytomegalovirus, adenovirus, and influenza virus, and by determining the recovery efficiency, repeatability, and detection limit of the protocol. The protocol was sensitive enough to detect 4 log₁₀ gene copies of virus. At room temperature, influenza RNA was stable on EWs for at least four days. When EWs were placed high in 32 influenza-infected patients' rooms, influenza RNA was detectable in 75% (N = 24) of EWs, suggesting that EWs are simple and reliable methods for influenza virus airborne detection.

The management of emergency spinal surgery during the COVID-19 pandemic in Italy

AIMS

The current pandemic caused by COVID-19 is the biggest challenge for national health systems for a century. While most medical resources are allocated to treat COVID-19 patients, several non-COVID-19 medical emergencies still need to be treated, including vertebral fractures and spinal cord compression. The aim of this paper is to report the early experience and an organizational protocol for emergency spinal surgery currently being used in a large metropolitan area by an integrated team of orthopaedic surgeons and neurosurgeons.

METHODS

An organizational model is presented based on case centralization in hub hospitals and early management of surgical cases to reduce hospital stay. Data from all the patients admitted for emergency spinal surgery from the beginning of the outbreak were prospectively collected and compared to data from patients admitted for the same reason in the same time span in the previous year, and treated by the same integrated team.

RESULTS

A total of 19 patients (11 males and eight females, with a mean age of 49.9 years (14 to 83)) were admitted either for vertebral fracture or spinal cord compression in a 19-day period, compared to the ten admitted in the previous year. No COVID-19 patients were treated. The mean time between admission and surgery was 1.7 days, significantly lower than 6.8 days the previous year (p < 0.001).

CONCLUSION

The structural organization and the management protocol we describe allowed us to reduce the time to surgery and ultimately hospital stay, thereby maximizing the already stretched medical resources available. We hope that our early experience can be of value to the medical communities that will soon be in the same emergency situation. Cite this article: Bone Joint J 2020;102-B(6):671-676.

Dynamic Competing Histone H4 K5K8 Acetylation and Butyrylation Are Hallmarks of Highly Active Gene Promoters

Recently discovered histone lysine acylation marks increase the functional diversity of nucleosomes well beyond acetylation. Here, we focus on histone butyrylation in the context of sperm cell differentiation. Specifically, we investigate the butyrylation of histone H4 lysine 5 and 8 at gene promoters where acetylation guides the binding of Brdt, a bromodomain-containing protein, thereby mediating stage-specific gene expression programs and post-meiotic chromatin reorganization. Genome-wide mapping data show that highly active Brdt-bound gene promoters systematically harbor competing histone acetylation and butyrylation marks at H4 K5 and H4 K8. Despite acting as a direct stimulator of transcription, histone butyrylation competes with acetylation, especially at H4 K5, to prevent Brdt binding. Additionally, H4 K5K8 butyrylation also marks retarded histone removal during late spermatogenesis. Hence, alternating H4 acetylation and butyrylation, while sustaining direct gene activation and dynamic bromodomain binding, could impact the final male epigenome features.

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Active gene TSSs are marked by competing H4 K5K8 acetylation and butyrylation

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Histone butyrylation directly stimulates transcription

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H4K5 butyrylation prevents binding of the testis specific gene expression-driver Brdt

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H4K5K8 butyrylation is associated with delayed histone removal in spermatogenic cells

Atad2 is a generalist facilitator of chromatin dynamics in embryonic stem cells

Although the conserved AAA ATPase and bromodomain factor, ATAD2, has been described as a transcriptional co-activator upregulated in many cancers, its function remains poorly understood. Here, using a combination of ChIP-seq, ChIP-proteomics, and RNA-seq experiments in embryonic stem cells where Atad2 is normally highly expressed, we found that Atad2 is an abundant nucleosome-bound protein present on active genes, associated with chromatin remodelling, DNA replication, and DNA repair factors. A structural analysis of its bromodomain and subsequent investigations demonstrate that histone acetylation guides ATAD2 to chromatin, resulting in an overall increase of chromatin accessibility and histone dynamics, which is required for the proper activity of the highly expressed gene fraction of the genome. While in exponentially growing cells Atad2 appears dispensable for cell growth, in differentiating ES cells Atad2 becomes critical in sustaining specific gene expression programmes, controlling proliferation and differentiation. Altogether, this work defines Atad2 as a facilitator of general chromatin-templated activities such as transcription.

Receptor-Independent Ectopic Activity of Prolactin Predicts Aggressive Lung Tumors and Indicates HDACi-Based Therapeutic Strategies

AIMS

Ectopic activation of tissue-specific genes accompanies malignant transformation in many cancers. Prolactin (PRL) aberrant activation in lung cancer was investigated here to highlight its value as a biomarker.

RESULTS

PRL is ectopically activated in a subset of very aggressive lung tumors, associated with a rapid fatal outcome, in our cohort of 293 lung tumor patients and in an external independent series of patients. Surprisingly PRL receptor expression was not detected in the vast majority of PRL-expressing lung tumors. Additionally, the analysis of the PRL transcripts in lung tumors and cell lines revealed systematic truncations of their 5' regions, including the signal peptide-encoding portions. PRL expression was found to sustain cancer-specific gene expression circuits encompassing genes that are normally responsive to hypoxia. Interestingly, this analysis also indicated that histone deacetylase (HDAC) inhibitors could counteract the PRL-associated transcriptional activity.

INNOVATION AND CONCLUSION

Altogether, this work not only unravels a yet unknown oncogenic mechanism but also indicates that the specific category of PRL-expressing aggressive lung cancers could be particularly responsive to an HDAC inhibitor-based treatment.

Acute traumatic fractures to the craniovertebral junction: preliminary experience with the "MILD" score scale

PURPOSE

Traumatic fractures to the craniovertebral junction (CVJ) are rare events requiring complex clinical management. Several classification systems are currently in use; however, recent improvements of junctional knowledge has focused attention on the role of ligaments and membranes in vertebral biomechanical stability. The aim of this study was to present our preliminary experience with the "MILD" score scale, which should allow fast and effective classification of all CVJ traumatic fractures based on vertebral instability in the acute setting.

METHODS

A prospective study was conducted on 38 consecutive patients with 43 traumatic junctional fractures identified by computed tomography (CT) scan in the acute trauma phase. The MILD scale was applied to all fractures, and a score was obtained for each patient. All cases underwent magnetic resonance imaging (MRI) to assess the anatomical integrity of ligaments and membranes.

RESULTS

Twenty-seven patients (71 %) were classified as MILD type 1 (0-1 points), showed a negative MRI, and healed with conservative treatment. Eight patients (21 %) were classified as MILD type 2 (2 points) and showed modest indirect signs of ligamentous injuries. Four of these patients healed with conservative treatment, while three patients underwent surgery due to wide bone fracture fragment displacement. Three patients (8 %) were classified as MILD type 3 (3 points), all of whom showed extensive ligamentous damage and underwent surgery.

CONCLUSIONS

The close association between the MILD scale and spinal instability is promising, although further studies are warranted in order to confirm our preliminary data.

Lysine 2-hydroxyisobutyrylation is a widely distributed active histone mark

We report the identification of a new type of histone mark, lysine 2-hydroxyisobutyrylation (Khib), and identify the mark at 63 human and mouse histone Khib sites, including 27 unique lysine sites that are not known to be modified by lysine acetylation (Kac) and lysine crotonylation (Kcr). This histone mark was initially identified by MS and then validated by chemical and biochemical methods. Histone Khib shows distinct genomic distributions from histone Kac or histone Kcr during male germ cell differentiation. Using chromatin immunoprecipitation sequencing, gene expression analysis and immunodetection, we show that in male germ cells, H4K8hib is associated with active gene transcription in meiotic and post-meiotic cells. In addition, H4K8ac-associated genes are included in and constitute only a subfraction of H4K8hib-labeled genes. The histone Khib mark is conserved and widely distributed, has high stoichiometry and induces a large structural change. These findings suggest its critical role on the regulation of chromatin functions.

A specific CBP/p300-dependent gene expression programme drives the metabolic remodelling in late stages of spermatogenesis

Histone hyperacetylation is thought to drive the replacement of histones by transition proteins that occur in elongating spermatids (ElS) after a general shut down of transcription. The molecular machineries underlying this histone hyperacetylation remain still undefined. Here, we focused our attention on the role of Cbp and p300 in histone hyperacetylation and in the preceding late-gene transcriptional activity in ElS. A strategy was designed to partially deplete Cbp and p300 in ElS. These cells progressed normally through spermiogenesis and showed normal histone hyperacetylation and removal. However, a genome-wide transcriptomic analysis, performed in the round spermatids (RS) and ElS, revealed the existence of a gene regulatory circuit encompassing genes presenting high expression levels in pre-meiotic cells, undergoing a repressed state in spermatocytes and early post-meiotic cells, but becoming reactivated in ElS, just prior to the global shutdown of transcription. Interestingly, this group of genes was over-represented within the genes affected by Cbp/p300 knock down and were all involved in metabolic remodelling. This study revealed the occurrence of a tightly regulated Cbp/p300-dependent gene expression programme that drives a specific metabolic state both in progenitor spermatogenic cells and in late transcriptionally active spermatids and confirmed a special link between Cpb/p300 and cell metabolism programming previously shown in somatic cells.

Ectopic activation of germline and placental genes identifies aggressive metastasis-prone lung cancers

Activation of normally silent tissue-specific genes and the resulting cell "identity crisis" are the unexplored consequences of malignant epigenetic reprogramming. We designed a strategy for investigating this reprogramming, which consisted of identifying a large number of tissue-restricted genes that are epigenetically silenced in normal somatic cells and then detecting their expression in cancer. This approach led to the demonstration that large-scale "off-context" gene activations systematically occur in a variety of cancer types. In our series of 293 lung tumors, we identified an ectopic gene expression signature associated with a subset of highly aggressive tumors, which predicted poor prognosis independently of the TNM (tumor size, node positivity, and metastasis) stage or histological subtype. The ability to isolate these tumors allowed us to reveal their common molecular features characterized by the acquisition of embryonic stem cell/germ cell gene expression profiles and the down-regulation of immune response genes. The methodical recognition of ectopic gene activations in cancer cells could serve as a basis for gene signature-guided tumor stratification, as well as for the discovery of oncogenic mechanisms, and expand the understanding of the biology of very aggressive tumors.

Identification of a novel BET bromodomain inhibitor-sensitive, gene regulatory circuit that controls Rituximab response and tumour growth in aggressive lymphoid cancers

Immuno-chemotherapy elicit high response rates in B-cell non-Hodgkin lymphoma but heterogeneity in response duration is observed, with some patients achieving cure and others showing refractory disease or relapse. Using a transcriptome-powered targeted proteomics screen, we discovered a gene regulatory circuit involving the nuclear factor CYCLON which characterizes aggressive disease and resistance to the anti-CD20 monoclonal antibody, Rituximab, in high-risk B-cell lymphoma. CYCLON knockdown was found to inhibit the aggressivity of MYC-overexpressing tumours in mice and to modulate gene expression programs of biological relevance to lymphoma. Furthermore, CYCLON knockdown increased the sensitivity of human lymphoma B cells to Rituximab in vitro and in vivo. Strikingly, this effect could be mimicked by in vitro treatment of lymphoma B cells with a small molecule inhibitor for BET bromodomain proteins (JQ1). In summary, this work has identified CYCLON as a new MYC cooperating factor that autonomously drives aggressive tumour growth and Rituximab resistance in lymphoma. This resistance mechanism is amenable to next-generation epigenetic therapy by BET bromodomain inhibition, thereby providing a new combination therapy rationale for high-risk lymphoma.

The nuclear factor CYCLON is a new MYC cooperating factor that drives tumor growth and Rituximab resistance in lymphoma. This resistance mechanism can be targeted by next-generation epigenetic therapy by BET bromodomain inhibition downstream of MYC.

Electronic properties of pristine and Se doped [001] silicon nanowires: an ab initio study

We report the results of first-principles density functional theory calculations of the properties of pristine and Se doped hydrogen passivated silicon nanowires oriented along the [001] direction. We show that the effect of confinement in the orthogonal directions is to increase the bandgap as the diameter of the nanowire is progressively reduced, as expected from the simple quantum confinement model. Moreover, we observe that the introduction of surface reconstruction before H passivation can lead to an indirect bandgap due to a shift of the valence band maximum away from the convergence point. We also study the formation energy and hyperfine parameters of Se located in different positions in a nanowire with diameter of 0.8 nm. Our results confirms a tendency to surface segregation for Se atoms, probably driven by deformations close to the nanowire surface. These deformations cause also a steep decrease in the hyperfine contact term of Se in surface positions compared to the situation when Se is placed near the axis of the nanowire. The latter values of the hyperfine contact term are instead much greater than the corresponding bulk values.

1q12 chromosome translocations form aberrant heterochromatic foci associated with changes in nuclear architecture and gene expression in B cell lymphoma

Epigenetic perturbations are increasingly described in cancer cells where they are thought to contribute to deregulated gene expression and genome instability. Here, we report the first evidence that a distinct category of chromosomal translocations observed in human tumours—those targeting 1q12 satellite DNA—can directly mediate such perturbations by promoting the formation of aberrant heterochromatic foci (aHCF). By detailed investigations of a 1q12 translocation to chromosome 2p, in a case of human B cell lymphoma, aberrant aHCF were shown to be localized to the nuclear periphery and to arise as a consequence of long range ‘pairing’ between the translocated 1q12 and chromosome 2 centromeric regions. Remarkably, adjacent 2p sequences showed increased levels of repressive histone modifications, including H4K20me3 and H3K9me3, and were bound by HP1. aHCF were associated to aberrant spatial localization and deregulated expression of a novel 2p gene (GMCL1) that was found to have prognostic impact in diffuse large B cell lymphoma. Thus constitutive heterochromatin rearrangements can contribute to tumourigenesis by perturbing gene expression via long range epigenetic mechanisms.

Functional characterization of ATAD2 as a new cancer/testis factor and a predictor of poor prognosis in breast and lung cancers

Cancer cells frequently express genes normally active in male germ cells. ATAD2 is one of them encoding a conserved factor harbouring an AAA type ATPase domain and a bromodomain. We show here that ATAD2 is highly expressed in testis as well as in many cancers of different origins and that its high expression is a strong predictor of rapid mortality in lung and breast cancers. These observations suggest that ATAD2 acts on upstream and basic cellular processes to enhance oncogenesis in a variety of unrelated cell types. Accordingly, our functional studies show that ATAD2 controls chromatin dynamics, genome transcriptional activities and apoptotic cell response. We could also highlight some of the important intrinsic properties of its two regulatory domains, including a functional cross-talk between the AAA ATPase domain and the bromodomain. Altogether, these data indicate that ATAD2 overexpression in somatic cells, by acting on basic properties of chromatin, may contribute to malignant transformation.

Size dependence of the Mössbauer recoilless fraction in β-Sn nanocrystals

We study the size dependence of the Mössbauer recoilless fraction in β-Sn nanocrystals by performing conversion electron Mössbauer spectroscopy at different temperatures. The Mössbauer recoilless fraction is intimately related to dynamical processes involving the nuclei during the γ-ray emission. The β-Sn nanocrystals are embedded in a SiO(2) matrix, and they have a mean diameter ranging from 7 to 17 nm. A lowering of the recoilless fraction with decreasing cluster size is observed. The smallest nanocrystals reveal a 60% reduction of the recoilless fraction compared to the bulk value, while for the largest clusters we observe the same Mössbauer recoilless fraction as in the bulk. This suggests that the dynamical properties of the β-Sn nanocrystals in SiO(2) approach those of the bulk for a critical mean diameter above 16 nm. The experimental results are compared with theoretical values obtained by a continuum model in which the relevant parameters are determined ab initio.

Focal extra-axial hemorrahagic mass with subdural hemorrhage secondare to extramedullary hematopoiesis in idiopathic myelodysplastic sindrome

Idiopathic myelodysplastic syndrome is a disease characterized by a clonal stem cell disorder in which megacaryocitic and granulocytic lineages are mainly involved; extramedullary myeloid metaplasia is due to abnormal location of myeloid tissue in other organs than bone marrow. Rarely the central nervous system is involved. When it happens, it is typical to find masses around the brain and pachymeningeal thickening, but it is very rare to find it associated with subdural haemorrhage, as in the case we describe in the present article. Considering our case and the literature we can suggest that radiological images associated with the clinical history of the patient suggestive for extramedullary hematopoiesis can be sufficient for a correct diagnosis and for a radiotherapy treatment, demanding surgery in the case of diagnostic doubts, massive hemorrahages or neurological decifits caused by the focal lesions.

Oligodendroglial gliomatosis cerebri. Case report

Gliomatosis cerebri of oligodendroglial origin is very unusual. In the present article we illustrate a case of this pathology, outlining his severity and suggesting it seems to be more aggressive than the astroglial type. We give a short focus about the diagnosis and the therapy of this neoplastic disease.

Intradural spinal metastasis of renal clear cell carcinoma causing cauda equina syndrome

Metastasis of renal clear cell carcinoma to the spinal cord are quite rare. Intradural localization causing a cauda equina syndrome has been previously reported only in two cases. The present report details the clinical, surgical and neuroradiological findings of a third case requiring emergency surgery, and presents data available from a brief review of cases reported in the literature. From the data available in the literature, we suggest that cerebral and spinal MRI and PET imaging should be widely performed in the staging of patients treated for renal clear cell carcinoma, in order to early detect CNS involvement.

Arnold's neuralgia caused by solitary fibrous tumor. Case report

Solitary fibrous tumor (SFT) is a mesenchymal tumor which has been identified in a wide variety of localizations, including soft tissues, peritoneum, retroperitoneum, mediastinum, upper respiratory tract, nasopharyngeal sinuses, periosteum and extremities, orbit, major body cavities, intraspinal and intracranial localizations. The authors describe a case of SFT found in the neck of a young patient suffering from Arnold's neuralgia. After surgery, diagnosis of SFT was based on characteristic histopathological findings, especially on immunohistochemical positive staining for CD34 antigen. It has been described also the characteristic patterns making this diagnose sure, focusing the point that cure is possible with complete excision of the lesion.

Meningeal melanocytoma of the temporal lobe. An uncommon tumor in an unusual location. Case report

Meningeal melanocytomas are rare pigmented tumors of the central nervous system. These tumors are benign melanotic lesions that derive from the melanocytes of the leptomeninges. They may occur anywhere in the cranial and spinal meninges; however, they are found prevalently in the posterior fossa and in the spinal cord. Their epidemiological features, natural history and response to treatment remain poorly understood, even if, in the last 2 years, some reviews have been published about it. We report a new case of intracranial supratentorial meningeal melanocytoma, in the temporal lobe, occurring in a 27-year-old man, admitted to our Institute with a long-time history of seizures. We report histological and radiological characteristics of our case, and briefly review the therapeutical options reported in literature. Preoperative neuroradiological finding is unclear; the preoperative diagnosis is usually meningioma, because of the long duration of symptomatology and the radiological appearance of the lesion as an extra-axial mass. Diagnosis of these lesions, as in our case, is made intraoperatively by the gross, jet-black appearance of the tumor and by histological examination. In spite of the benign biologic behaviour, the prognosis remains uncertain, because of the possible local recurrences. According to the results of some works of the last years, it seems appropriate to use postoperative radiotherapy for those patients with symptomatic residual, progressive or recurrent tumors not amenable to further resection.

Anomalous LO phonon lifetime in AlAs

The temperature dependence of the frequencies and linewidths of the Raman-active longitudinal optical (LO) phonons in GaAs and AlAs have been measured. The low-temperature lifetime of the LO phonon in AlAs is found to be 9.7 ps, very close to the corresponding GaAs value of 9.5 ps. This contradicts early theoretical predictions. The agreement between theory and experiment can be restored when the accidental degeneracy between the AlAs LO phonon frequency and a feature in the two-phonon density of states is taken into account.