The MYCN oncoprotein is an RNA-binding accessory factor of the nuclear exosome targeting complex.

The MYCN oncoprotein binds active promoters in a heterodimer with its partner protein MAX. MYCN also interacts with the nuclear exosome, a 3'-5' exoribonuclease complex, suggesting a function in RNA metabolism. Here, we show that MYCN forms stable high-molecular-weight complexes with the exosome and multiple RNA-binding proteins. MYCN binds RNA in vitro and in cells via a conserved sequence termed MYCBoxI. In cells, MYCN associates with thousands of intronic transcripts together with the ZCCHC8 subunit of the nuclear exosome targeting complex and enhances their processing. Perturbing exosome function results in global re-localization of MYCN from promoters to intronic RNAs. On chromatin, MYCN is then replaced by the MNT(MXD6) repressor protein, inhibiting MYCN-dependent transcription. RNA-binding-deficient alleles show that RNA-binding limits MYCN's ability to activate cell growth-related genes but is required for MYCN's ability to promote progression through S phase and enhance the stress resilience of neuroblastoma cells.

MYCN recruits the nuclear exosome complex to RNA polymerase II to prevent transcription-replication conflicts.

The MYCN oncoprotein drives the development of numerous neuroendocrine and pediatric tumors. Here we show that MYCN interacts with the nuclear RNA exosome, a 3'-5' exoribonuclease complex, and recruits the exosome to its target genes. In the absence of the exosome, MYCN-directed elongation by RNA polymerase II (RNAPII) is slow and non-productive on a large group of cell-cycle-regulated genes. During the S phase of MYCN-driven tumor cells, the exosome is required to prevent the accumulation of stalled replication forks and of double-strand breaks close to the transcription start sites. Upon depletion of the exosome, activation of ATM causes recruitment of BRCA1, which stabilizes nuclear mRNA decapping complexes, leading to MYCN-dependent transcription termination. Disruption of mRNA decapping in turn activates ATR, indicating transcription-replication conflicts. We propose that exosome recruitment by MYCN maintains productive transcription elongation during S phase and prevents transcription-replication conflicts to maintain the rapid proliferation of neuroendocrine tumor cells.

MYC multimers shield stalled replication forks from RNA polymerase.

Oncoproteins of the MYC family drive the development of numerous human tumours1. In unperturbed cells, MYC proteins bind to nearly all active promoters and control transcription by RNA polymerase II2,3. MYC proteins can also coordinate transcription with DNA replication4,5 and promote the repair of transcription-associated DNA damage6, but how they exert these mechanistically diverse functions is unknown. Here we show that MYC dissociates from many of its binding sites in active promoters and forms multimeric, often sphere-like structures in response to perturbation of transcription elongation, mRNA splicing or inhibition of the proteasome. Multimerization is accompanied by a global change in the MYC interactome towards proteins involved in transcription termination and RNA processing. MYC multimers accumulate on chromatin immediately adjacent to stalled replication forks and surround FANCD2, ATR and BRCA1 proteins, which are located at stalled forks7,8. MYC multimerization is triggered in a HUWE16 and ubiquitylation-dependent manner. At active promoters, MYC multimers block antisense transcription and stabilize FANCD2 association with chromatin. This limits DNA double strand break formation during S-phase, suggesting that the multimerization of MYC enables tumour cells to proliferate under stressful conditions.

Identification of a localized nonsense-mediated decay pathway at the endoplasmic reticulum.

Nonsense-mediated decay (NMD) is a translation-dependent RNA quality control mechanism that occurs in the cytoplasm. However, it is unknown how NMD regulates the stability of RNAs translated at the endoplasmic reticulum (ER). Here, we identify a localized NMD pathway dedicated to ER-translated mRNAs. We previously identified NBAS, a component of the Syntaxin 18 complex involved in Golgi-to-ER trafficking, as a novel NMD factor. Furthermore, we show that NBAS fulfills an independent function in NMD. This ER-NMD pathway requires the interaction of NBAS with the core NMD factor UPF1, which is partially localized at the ER in the proximity of the translocon. NBAS and UPF1 coregulate the stability of ER-associated transcripts, in particular those associated with the cellular stress response. We propose a model where NBAS recruits UPF1 to the membrane of the ER and activates an ER-dedicated NMD pathway, thus providing an ER-protective function by ensuring quality control of ER-translated mRNAs.

Multiple similarity drug-target interaction prediction with random walks and matrix factorization.

The discovery of drug-target interactions (DTIs) is a very promising area of research with great potential. The accurate identification of reliable interactions among drugs and proteins via computational methods, which typically leverage heterogeneous information retrieved from diverse data sources, can boost the development of effective pharmaceuticals. Although random walk and matrix factorization techniques are widely used in DTI prediction, they have several limitations. Random walk-based embedding generation is usually conducted in an unsupervised manner, while the linear similarity combination in matrix factorization distorts individual insights offered by different views. To tackle these issues, we take a multi-layered network approach to handle diverse drug and target similarities, and propose a novel optimization framework, called Multiple similarity DeepWalk-based Matrix Factorization (MDMF), for DTI prediction. The framework unifies embedding generation and interaction prediction, learning vector representations of drugs and targets that not only retain higher order proximity across all hyper-layers and layer-specific local invariance, but also approximate the interactions with their inner product. Furthermore, we develop an ensemble method (MDMF2A) that integrates two instantiations of the MDMF model, optimizing the area under the precision-recall curve (AUPR) and the area under the receiver operating characteristic curve (AUC), respectively. The empirical study on real-world DTI datasets shows that our method achieves statistically significant improvement over current state-of-the-art approaches in four different settings. Moreover, the validation of highly ranked non-interacting pairs also demonstrates the potential of MDMF2A to discover novel DTIs.

Molecular characterization of Lernathropus kroyeri from intensive aquaculture and pathophysiology of infested sea bass.

The copepod Lernathropus kroyeri constitutes one of the major parasites for the Mediterranean aquaculture, infesting the sea bass Dicentrarchus labrax causing thus disruptions of growth performance and occasionally mortalities. Despite the large spread and the high frequency of this parasite in mariculture farms of Eastern Mediterranean, L. kroyeri genetic profile from aquaculture as well as the pathophysiological response of D. labrax have not been studied so far. Keeping this in mind, in the present study we investigated the L. kroyeri infestation on D. labrax from two farms in Greece, examining both healthy and heavy parasitized individuals. Assays included histopathology, phylogenetic reconstruction of the parasite and physiological response of the fish by the means of antioxidant, inflammatory metabolic and stress related gene expression analysis at both mRNA and protein levels. Genetic analysis indicated that L. kroyeri composes a monophyletic group, highly phylogenetically distant from other congeneric groups. Heavy infested D. labrax witnessed a significantly increased immune response that further led to oxidative stress and metabolic alterations. Overall, our results demonstrate the, seasonally independent, high infestation of this parasitic copepods, which continue to affect Mediterranean intensive aquaculture systems.

3D-printed glenoid implant reconstruction, after partial scapulectomy for malignant tumors: a case series.

PURPOSE: Glenoid tumors are extremely rare, and reconstruction remains very challenging. The aim of this study is to present the clinical and functional outcomes, of a new glenoid reconstruction method using 3-dimensional-printed implant. METHODS: Four patients with primary glenoid tumors underwent reconstruction using 3-dimensional-printed glenoid implant linked with reverse shoulder arthroplasty. We retrospectively reviewed the clinical and functional outcome, using MSTS and DASH score, as well as complications' rate. RESULTS: Wide excision was achieved in all patients. No local recurrence or distant metastasis was diagnosed at the follow-up period. The mean MSTS score was 80.5%, and DASH score was 15.2%. According to Hendersons' classification, there were no postoperative complications. CONCLUSION: The use of 3-dimensional-printed implants, can be a very reliable solution with satisfying clinical and functional outcomes for reconstruction, in patients with musculoskeletal malignancies of the glenoid. Level of evidence IV Treatment Study.

Rotational Thromboelastometry Predicts Transfusion Requirements in Total Joint Arthroplasties.

The frequency of red blood cell (RBC) transfusions is high in total joint arthroplasties, and the hemorrhagic risk is associated with both surgery- and patient-related factors. This study aims to assess the ability of rotational thromboelastometry (ROTEM) to identify patients at high risk for transfusion and excessive bleeding. A prospective observational study was conducted including 206 patients who underwent total knee or hip arthroplasties. Assessment of the coagulation status was performed preoperatively and immediately postoperatively using ROTEM analysis and conventional coagulation tests. The number of RBC transfusions and the postoperative hemoglobin drop were recorded. ROTEM findings were compared between transfused and nontransfused patients, and also between patients with and without excessive bleeding. Higher values of postoperative FIBTEM maximum clot firmness (MCF) were associated with lower risks of transfusion (odds ration [OR]: 0.66, 95% confidence interval [CI]: 0.57-0.78, p<0.001) and excessive bleeding (OR: 0.58, 95% CI: 0.36-0.94, p=0.028). A postoperative FIBTEM MCF value ≤10mm had 80.1% (95% CI: 73.1-85.9%) sensitivity with 75.5% (95% CI: 60.4-87.1%) specificity to predict transfusion requirements, and 70.5% (95% CI: 63.6-76.8%) sensitivity with 88.8% (95% CI: 51.7-99.7%) specificity to predict excessive bleeding. The estimated average probability of transfusion in patients with FIBTEM MCF values of 0 to 4mm is 86.3%. ROTEM assay demonstrated high predictive ability for transfusion and excessive bleeding. Identification of patients at risk for transfusion could allow blood banks to ensure adequate blood supply, while also more intense blood-salvaging strategies could be implemented in these patients.

Association between neonatal phototherapy and future cancer: an updated systematic review and meta-analysis.

Phototherapy is the main treatment of neonatal hyperbilirubinemia to prevent encephalopathy. It is generally believed to be safe; however, some studies have shown it might be associated with cancer development. In this systematic review and meta-analysis, we aimed to assess the effect of neonatal phototherapy on future cancer risk. A systematic search in 13 databases was conducted in December 2018 and updated in August 2022 to identify studies that report cancer development after exposure to phototherapy. Throughout the study period, regular manual searches were also conducted to include new studies. A meta-analysis using R programming language was done in which the odds ratios (ORs) with 95% confidence intervals (CIs) were estimated and pooled using the reported adjusted and unadjusted data. Fifteen studies were included. A statistically significant association was detected between neonatal phototherapy and any type of cancer (OR 1.24; 95% CI 1.1, 1.4), any hematopoietic cancer (OR 1.49; 95% CI 1.17, 1.91), any leukemia (OR 1.35; 95% CI 1.08, 1.67), and myeloid leukemia (OR 2.86; 95% CI 1.4, 5.84). The other investigated cancers (lymphoid leukemia, Hodgkin's lymphoma, kidney cancer, nervous system cancer, and skin cancer) were not associated with phototherapy.  Conclusions: Phototherapy may carry a possible risk of future cancers. Future research is needed to quantify the magnitude of the cancer risk. These future studies should consider predictors of preterm birth or exclude premature babies from their analysis. What is Known • There were various reports about the possible association between phototherapy in neonates and the increased risk of cancer in the future. What is New • A statistically significant association between phototherapy and various hematopoietic cancers (especially myeloid leukemia) was recorded. • The effect of the duration of phototherapy on the increased risk of hematopoietic cancers is yet unclear.

Fibrinolysis shutdown and elevated D-dimer levels have high prognostic capacity for postoperative thromboembolic complications in patients with bone tumors.

Surgical resection of malignant bone tumors is associated with a high risk of venous thromboembolism (VTE). The purpose of this study was to evaluate the association between rotational thromboelastometry (ROTEM) parameters and VTE following oncologic resections, and to evaluate their prognostic capacity for this complication. A prospective observational study was conducted including 113 patients who underwent surgical resection of malignant bone tumors. ROTEM analysis and conventional coagulation studies were performed preoperatively and on the 2nd postoperative day, while patients were followed for the development of VTE. Logistic regression was used to assess the association between ROTEM parameters and occurrence of VTE. The area under the receiver operating characteristic curve (AUC), sensitivity and specificity were calculated as measures of discrimination and predictive accuracy. Fourteen patients (12.4%) developed symptomatic VTE. Development of VTE was associated with shortened INTEM CFT (Odds Ratio [OR] 0.90, 95% Confidence Interval [CI] 0.84 - 0.96, p = 0.004), higher INTEM A10 (OR 1.21, 95% CI 1.07 - 1.36, p = 0.002), higher INTEM MCF (OR 1.22, 95% CI 1.08 - 1.37, p = 0.001) and higher INTEM LI60 (OR 2.10, 95% CI 1.38 - 3.21, p = 0.001). An INTEM LI60 value indicative of fibrinolysis shutdown (≥ 98%) had the best predictive accuracy for VTE (AUC = 0.887, 95% CI 0.824 - 0.951, sensitivity = 100%, specificity = 67.0%), higher than that of D-dimer levels (p = 0.028). ROTEM parameters were promising predictors of symptomatic VTE. Fibrinolysis shutdown as reflected by ROTEM LI60 and high D-dimer levels can aid the identification of high-risk patients. Future studies should evaluate whether the addition of ROTEM findings to an expanded risk-assessing model can improve the predictive capacity and provide better guidance in thromboprophylaxis.

The impact of ascidian biofouling on the farmed Mediterranean mussel Mytilus galloprovincialis physiology and welfare, revealed by stress biomarkers.

In biofouling communities, ascidians are among the most damaging species, presenting severe threats, such as depressed growth rates and decreased chances of lower survival, to shellfish aquaculture. However, little is known concerning the fouled shellfish physiology. In an effort to obtain information for the magnitude of stress caused by ascidians to farmed Mytilus galloprovincialis, five seasonal samplings took place in a mussel aquaculture farm suffering from ascidian biofoulants, in Vistonicos Bay, Greece. The dominant ascidian species were recorded and several stress biomarkers, including Hsp gene expression at both mRNA and protein levels, as well as MAPKs levels, and enzymatic activities of intermediate metabolism were examined. Almost all investigated biomarkers revealed elevated stress levels in fouled mussels compared to non-fouled. This enhanced physiological stress seems to be season-independent and can be attributed to the oxidative stress and/or feed deprivation caused by ascidian biofouling, thus illuminating the biological impact of this phenomenon.

Serum lactate dehydrogenase and its isoenzymes as predictors of clinical outcomes in acute exacerbation of chronic obstructive pulmonary disease: a retrospective analysis of a hospitalized cohort.

We aimed to test the association between serum lactate dehydrogenase (LDH) and its isoenzymes and treatment outcomes during hospitalization for acute exacerbation of chronic obstructive pulmonary disease (AECOPD). Thirty-eight AECOPD patients were recruited from a tertiary hospital from December 2017 to June 2018. Serum LDH and LDH isoenzymes were measured on venous blood collected at admission. Treatment outcomes included duration of hospital stay, initiation of non-invasive (NIV) or mechanical ventilation, initiation of antipseudomonal antibiotics, change in empirical antibiotic treatment, need for intravenous corticosteroids or methylxanthines, and percentage of change in C-reactive protein from admission to the third day. Multivariate linear and binary logistic regression analyses were used to test the study's objectives. We found that, after adjusting for age, gender, comorbidities, COPD severity, level of hypoxemia, and inflammation markers, each 10 U/L increase in serum LDH was associated with prolongation of the hospital stay by 0.25 (0.03, 0.46) days, 42% higher odds (odds ratio [OR] 1.42 [1.00, 2.03]) for need of NIV, and 25% higher odds (OR 1.25 [1.04, 1.49]) for initiation of antipseudomonal treatment. LDH1 and LDH2 were the LDH isoenzymes that mainly drove these relationships. LDH release in the context of an AECOPD could originate from lung, muscle, or heart tissue damage due to airway inflammation, respiratory muscle recruitment, and myocardial stress. Myocardial injury and aerobic adaptation in respiratory muscles may explain the predominance of LDH1 and LDH2 isoenzymes in these associations.

A Scoping Review of the Recent Clinical Practice Regarding the Evaluation of Bone Mineral Density in Children and Adolescents with Neuromuscular Diseases.

Introduction: Neuromuscular Diseases (NMD) are associated with decreased bone strength due to altered muscle-bone interaction. However, the evaluation of bone quality remains a certain challenge in these patients. The purpose of this scoping review is to investigate the recent literature regarding the assessment of Bone Mineral Density (BMD) in this population. Methods: An electronic search of the PubMed and Scopus database was performed considering studies published in the English literature after 2007 that evaluated BMD in pediatric and adolescent patients with NMD. We excluded studies that evaluated patients > 20 years, studies not involving humans, and studies investigating bone mineral density in various pediatric conditions, but without specific data on NMD. Results: Overall, 19 studies were included that evaluated BMD in 1983 patients with NMD. Duchenne Muscular Dystrophy was the most widely studied disease (n = 11 studies). Dual energy X-ray absorptiometry (DEXA) was the most common diagnostic modality for BMD evaluation, while the most frequent site for BMD measurement was the lumbar spine (89.4%, n = 17 studies), followed by total body BMD (68.4%, n = 13 studies). Low BMD in children with NMD was demonstrated in all studies, especially after loss of ambulation. Moreover, a positive correlation between lower BMD and older age was shown. Conclusions: BMD evaluation in NMD remains a clinical challenge, as indicated by the high heterogeneity regarding the optimal site and technique for the evaluation of bone quality in these patients. Although DXA is currently the diagnostic modality of choice, a consensus regarding the optimal site for BMD measurement, and the adjustment method for its obtained measurements for parameters such as age and height is needed.

The impact of glenoid parameters and implant overstuffing on functional outcomes of shoulder hemiarthroplasty in patients with glenohumeral joint arthritis.

PURPOSE: The outcomes of shoulder hemiarthroplasty are highly dependent on the baseline glenoid morphology and the rotator cuff integrity. The objective of this study was to assess whether certain glenoid parameters and implant overstuffing are associated with worse clinical outcomes following shoulder hemiarthroplasty. METHODS: We retrospectively reviewed 25 patients who underwent shoulder hemiarthroplasty for shoulder arthritis, with a mean follow-up of 5.3 years. The baseline glenoid morphology, the glenoid wear rate, the proximal humeral head migration and implant overstuffing were evaluated radiologically in all patients. The radiological parameters were correlated with the functional outcomes. RESULTS: The Constant-Murley score, the ASES score, and the OSS score were significantly better for patients with a concentric baseline glenoid compared to those with an eccentric glenoid. The Constant-Murley score and the ASES score were also improved in patients without implant overstuffing compared to patients with implant overstuffing (p < 0.05). However, glenoid wear was not associated with worse functional outcomes (p = 0.23 for Constant-Murley score, p = 0.15 for ASES score and p = 0.27 for OSS score). Last, a worse Constant-Murley score was strongly correlated with proximal humeral head migration (p < 0.001), while worse ASES and OSS scores were moderately correlated with proximal humeral head migration (p < 0.001). CONCLUSION: Our findings indicate that the results of hemiarthroplasty can be improved through careful selection of patients upon the baseline glenoid type morphology and proper implant sizing to avoid implant overstuffing. Moreover, glenoid wear is not associated with worse clinical outcomes, therefore shoulder hemiarthroplasty should be reconsidered as an alternative in younger patients with shoulder arthritis.

Control of Hox transcription factor concentration and cell-to-cell variability by an auto-regulatory switch.

The variability in transcription factor concentration among cells is an important developmental determinant, yet how variability is controlled remains poorly understood. Studies of variability have focused predominantly on monitoring mRNA production noise. Little information exists about transcription factor protein variability, as this requires the use of quantitative methods with single-molecule sensitivity. Using Fluorescence Correlation Spectroscopy (FCS), we have characterized the concentration and variability of 14 endogenously tagged TFs in live Drosophila imaginal discs. For the Hox TF Antennapedia, we investigated whether protein variability results from random stochastic events or is developmentally regulated. We found that Antennapedia transitioned from low concentration/high variability early, to high concentration/low variability later, in development. FCS and temporally resolved genetic studies uncovered that Antennapedia itself is necessary and sufficient to drive a developmental regulatory switch from auto-activation to auto-repression, thereby reducing variability. This switch is controlled by progressive changes in relative concentrations of preferentially activating and repressing Antennapedia isoforms, which bind chromatin with different affinities. Mathematical modeling demonstrated that the experimentally supported auto-regulatory circuit can explain the increase of Antennapedia concentration and suppression of variability over time.

Interleukin-1 (IL-1) and the inflammasome in cancer.

Numerous preclinical and clinical studies have demonstrated the significant contribution of inflammation to the development and progression of various types of cancer. Inflammation in the tumor microenvironment mediates complex interactions between innate immunity, adaptive immunity, microbiomes and stroma, and ultimately alters the overall fitness of tumor cells at multiple stages of carcinogenesis. Malignancies are known to arise in areas of chronic inflammation and inflammation in the tumor microenvironment (often called tumor-promoting inflammation) is believed to allow cancer cells to evade immunosurveillance while promoting genetic instability, survival and progression. Among the strongest data suggesting a causal role for inflammation in cancer come from the recent CANTOS trial which demonstrated that interleukin-1ß (IL-1ß) inhibition with canakinumab leads to a significant, dose-dependent decrease in incident lung cancer. This observation has launched a series of additional clinical studies to understand the role of IL-1ß and the inflammasome in cancer, and the clinical utility of IL-1ß inhibition in different stages of lung cancer. In this article we will review recent data implicating IL-1ß signaling and its upstream regulator NLRP3 in both solid tumor and hematologic malignancies. We will discuss the key preclinical observations and the current clinical landscape, and describe the pharmacologic tools which will be used to evaluate the effects of blocking tumor-promoting inflammation clinically.

Drug tolerability: How much ambiguity can be tolerated? A systematic review of the assessment of tolerability in clinical studies.

AIMS: Drug tolerability refers to the degree to which drugs' overt adverse effects can be tolerated by patients. The tolerability profile is of comparative importance to its efficacy and safety, as it largely determines adherence to treatment and ultimately treatment success or failure. However, the term is frequently used imprecisely, and it is unclear if tolerability is limited to subjective patient-reported symptoms or also covers certain objective signs and findings. The aim of this systematic review was to assess how clinical studies define, evaluate and present drug tolerability. METHODS: The study consisted of a systematic review of clinical studies in PubMed® reporting the term "tolerability". RESULTS: Eighty clinical studies were screened and 56 studies reporting drug tolerability were retained. None of the retained studies defined events encompassed by the term tolerability by making a distinction between safety and tolerability. Twenty-five studies claimed to evaluate tolerability, but none of them described how to evaluate tolerability from the patient perspective. Most studies (54 out of 56) concluded that the treatment was well tolerated, apparently implying favourable safety. However, none of them actually presented tolerability in terms of a contrast between safety and tolerability. CONCLUSIONS: Tolerability is used frequently, albeit incorrectly, to refer to a drug's favourable safety profile. Focused evaluation of drug tolerability (i.e., the patient perspective of adverse drug reactions) should become routine. Presentation in regulatory documents, such as risk management plan summaries, product information and patient leaflets should be a continuation of the process of patient-centred healthcare.

Aspergillus spp. osteoarticular infections: an updated systematic review on the diagnosis, treatment and outcomes of 186 confirmed cases.

Aspergillus spp. osteoarticular infections are destructive opportunistic infections, while there is no clear consensus on their management. The purpose of this review is to investigate the current literature regarding Aspergillus spp. osteoarticular infections. An electronic search of the PubMed and Scopus databases was conducted considering studies that assessed osteoarticular infections from Aspergillus spp. We included only studies with biopsy proven documentation of positive cultures or histological findings for Aspergillus spp., and those with essential information for each case such as the anatomical location of the infection, the type of treatment (conservative, surgical, combination), the antifungal therapy, and the outcome. Overall, 148 studies from 1965 to 2021 including 186 patients were included in the review. One hundred and seven (57.5%) patients underwent surgical debridement in addition to antifungal therapy, while 79 (42.7%) patients were treated only conservatively. Complete infection resolution was reported in 107 (57.5%) patients, while partial resolution in 29 (15.5%) patients. Surgical debridement resulted in higher complete infection resolution rate compared to only antifungal therapy (70.0% vs. 40.5%, P < 0.001), while complete resolution rate was similar for antifungal monotherapy and combination/sequential therapy (58.3% vs. 54.5%; P = 0.76). Last, complete resolution rate was also similar for monotherapy with amphotericin B (58.1%) and voriconazole (58.6%; P = 0.95). The results of this study indicate that antifungal monotherapy has similar efficacy with combination/sequential therapy, while voriconazole has similar efficacy with amphotericin B. Moreover, surgical debridement of the infected focus results in better outcomes in terms of infection eradication compared to conservative treatment. LAY SUMMARY: Antifungal monotherapy has similar efficacy with combination/sequential therapy, and voriconazole has similar efficacy with amphotericin B for the treatment of Aspergillus spp. osteoarticular infections, while surgical debridement of the infected focus improves the infection eradication rate.

Brucella spp. distribution, hosting ruminants from Greece, applying various molecular identification techniques.

BACKGROUND: Brucellosis still remains an endemic disease for both livestock and human in Greece, influencing the primary sector and national economy in general. Although farm animals and particularly ruminants constitute the natural hosts of the disease, transmission to humans is not uncommon, thus representing a serious occupational disease as well. Under this prism, knowledge concerning Brucella species distribution in ruminants is considered a high priority. There are various molecular methodologies for Brucella detection with however differential discriminant capacity. Hence, the aim of this survey was to achieve nationally Brucella epidemiology baseline genotyping data at species and subtype level, as well as to evaluate the pros and cons of different molecular techniques utilized for detection of Brucella species. Thirty-nine tissue samples from 30 domestic ruminants, which were found positive applying a screening PCR, were tested by four different molecular techniques i.e. sequencing of the 16S rRNA, the BP26 and the OMP31 regions, and the MLVA typing panel 1 assay of minisatellite markers. RESULTS: Only one haplotype was revealed from the 16S rRNA sequencing analysis, indicating that molecular identification of Brucella bacteria based on this marker might be feasible solely up to genus level. BP26 sequencing analysis and MLVA were in complete agreement detecting both B. melitensis and B. abortus. An interesting exception was observed in 11 samples, of lower quality extracted DNA, in which not all expected MLVA amplicons were produced and identification was based on the remaining ones as well as on BP26. On the contrary OMP31 failed to provide a clear band in any of the examined samples. CONCLUSIONS: The present study reveals the constant circulation of Brucella bacteria in ruminants throughout Greece. Further, according to our results, BP26 gene represents a very good alternative to MLVA minisatellite assay, particularly in lower quality DNA samples.

The apical protein Apnoia interacts with Crumbs to regulate tracheal growth and inflation.

Most organs of multicellular organisms are built from epithelial tubes. To exert their functions, tubes rely on apico-basal polarity, on junctions, which form a barrier to separate the inside from the outside, and on a proper lumen, required for gas or liquid transport. Here we identify apnoia (apn), a novel Drosophila gene required for tracheal tube elongation and lumen stability at larval stages. Larvae lacking Apn show abnormal tracheal inflation and twisted airway tubes, but no obvious defects in early steps of tracheal maturation. apn encodes a transmembrane protein, primarily expressed in the tracheae, which exerts its function by controlling the localization of Crumbs (Crb), an evolutionarily conserved apical determinant. Apn physically interacts with Crb to control its localization and maintenance at the apical membrane of developing airways. In apn mutant tracheal cells, Crb fails to localize apically and is trapped in retromer-positive vesicles. Consistent with the role of Crb in apical membrane growth, RNAi-mediated knockdown of Crb results in decreased apical surface growth of tracheal cells and impaired axial elongation of the dorsal trunk. We conclude that Apn is a novel regulator of tracheal tube expansion in larval tracheae, the function of which is mediated by Crb.