Mapping and characterization of G-quadruplexes in monkeypox genomes.

Monkeypox virus (MPXV) is a double-stranded DNA virus from the family Poxviridae, which is endemic in West and Central Africa. Various human outbreaks occurred in the 1980s, resulting from a cessation of smallpox vaccination. Recently, MPXV cases have reemerged in non-endemic nations, and the 2022 outbreak has been declared a public health emergency. Treatment optionsare limited, and many countries lack the infrastructure to provide symptomatic treatments. The development of cost-effective antivirals could ease severe health outcomes. G-quadruplexes have been a target of interest in treating viral infections with different chemicals. In the present work, a genomic-scale mapping of different MPXV isolates highlighted two conserved putative quadruplex-forming sequences MPXV-exclusive in 590 isolates. Subsequently, we assessed the G-quadruplex formation using circular dichroism spectroscopy and solution small-angle X-ray scattering. Furthermore, biochemical assays indicated the ability of MPXV quadruplexes to be recognized by two specific G4-binding partners-Thioflavin T and DHX36. Additionally, our work also suggests that a quadruplex binding small-molecule with previously reported antiviral activity, TMPyP4, interacts with MPXV G-quadruplexes with nanomolar affinity in the presence and absence of DHX36. Finally, cell biology experiments suggests that TMPyP4 treatment substantially reduced gene expression of MPXV proteins. In summary, our work provides insights into the G-quadruplexes from the MPXV genome that can be further exploited to develop therapeutics.

Clinical management of high-output stoma: a systematic literature review and meta-analysis.

PURPOSE: High output is a common complication after stoma formation. Although the management of high output is described in the literature, there is a lack of consensus on definitions and treatment. Our aim was to review and summarise the current best evidence. METHODS: MEDLINE, Cochrane Library, BNI, CINAHL, EMBASE, EMCARE, and ClinicalTrials.gov were searched from 1 Jan 2000 to 31 Dec 2021 for relevant articles on adult patients with a high-output stoma. Patients with enteroatmospheric fistulas and case series/reports were excluded. Risk of bias was assessed using RoB2 and MINORS. The review was registered in PROSPERO (CRD42021226621). RESULTS: The search strategy identified 1095 articles, of which 32 studies with 768 patients met the inclusion criteria. These studies comprised 15 randomised controlled trials, 13 non-randomised prospective trials, and 4 retrospective cohort studies. Eighteen different interventions were assessed. In the meta-analysis, there was no difference in stoma output between controls and somatostatin analogues (g - 1.72, 95% CI - 4.09 to 0.65, p = 0.11, I2 = 88%, t2 = 3.09), loperamide (g - 0.34, 95% CI - 0.69 to 0.01, p = 0.05, I2 = 0%, t2 = 0) and omeprazole (g - 0.31, 95% CI  - 2.46 to 1.84, p = 0.32, I2 = 0%, t2 = 0). Thirteen randomised trials showed high concern of bias, one some concern, and one low concern. The non-randomised/retrospective trials had a median MINORS score of 12 out of 24 (range 7-17). CONCLUSION: There is limited high-quality evidence favouring any specific widely used drug over the others in the management of high-output stoma. Evidence, however, is weak due to inconsistent definitions, risk of bias and poor methodology in the existing studies. We recommend the development of validated core descriptor and outcomes sets, as well as patient-reported outcome measures.

Allelopathy: an alternative tool for sustainable agriculture.

Population increase, poverty, environmental degradation, and the use of synthetic herbicides are interdependent and closely linked and hence influence global food safety and stability of world agriculture. On the one hand, varied weeds, insects, and other pests have caused a tremendous loss in agricultural crop productivity annually. On the other hand, the use of synthetic insecticides, herbicides, fungicides, and other pesticides significantly disturbed the ecology of biotic communities in agricultural and natural ecosystems. Eventually, it destroyed the ecological balance in food chains. Interestingly, natural products released by the plants (allelochemicals) are secondary metabolites involved in ecological interactions and could be an important source of alternative agrochemicals. Mainly released by the plants as an outcome of acquaintances with other plants in their vicinity, these allelochemicals can also be used as eco-friendly substitutes for synthetic herbicides and other pesticides. Despite these facts, agrochemicals are either preferred over allelochemicals or the latter are not known in the direction of their use in achieving sustainability in agriculture. Given this, considering recent reports, this paper aims to: (1) emphasize allelochemicals; (2) overview the major biochemistry of allelochemicals; (3) critically discuss the role of allelopathy (and underlying major mechanisms) in the management of noxious weeds, insect pests, and major plant pathogens; and (4) enlighten the significant aspects so far not or least explored in the current context.

Prostate cancer grade downgrading at time of prostatectomy provides risk-stratification insight into future tumor behavior after prostatectomy.

BACKGROUND: Prostate biopsy (Bx) sampling-based diagnosis of prostate cancer (PCa) has well-described inaccuracy when compared against whole gland analysis upon prostatectomy. Although upgrading of PCa Grade Group (GG) is often described, the occurrence and prognostic implications of downgrading PCa GG at the time of radical prostatectomy (RP) is less understood. Our objective was to evaluate whether downgrading PCa GG at the time of RP was associated with future tumor behavior. METHODS: The SEER database was searched from 2010 to 2017 and patients were included if they were assigned pathological grades on both Bx and RP specimen. Patients were stratified into Bx GG > RP GG and Bx GG ≤ RP GG groups, and tumor behavior after treatment was examined. Cox regression was used for the survival analysis. RESULTS: Here, 99,835 patients were included in this study. A total of 18,516 (18.5%) patients encountered downgrading from Bx GG to RP GG. A downgrading of 1 grade occurred in 13,969 (75.4%) of these patients and of 2 or more grades occurred in 4547 (24.6%) patients. A history of higher Bx GG compared with RP GG increased the risk of cancer-specific mortality (CSM) for each given RP GG controlling for age, race, preop prostate-specific antigen level, percentage of positive biopsy cores, and pathologic TNM stages. Specifically, a history of high Bx GG conferred a 45% increased risk of CSM for any given RP GG (hazard ratio = 1.45 95% confidence interval = 1.16-1.82, p < 0.001). CONCLUSION: A history of higher Bx GG, and hence downgrading at the time of RP, demonstrates some value as a risk-stratification tool for future cancer outcomes after prostatectomy.

Genomic biomarkers to guide precision radiotherapy in prostate cancer.

Our ability to prognosticate the clinical course of patients with cancer has historically been limited to clinical, histopathological, and radiographic features. It has long been clear however, that these data alone do not adequately capture the heterogeneity and breadth of disease trajectories experienced by patients. The advent of efficient genomic sequencing has led to a revolution in cancer care as we try to understand and personalize treatment specific to patient clinico-genomic phenotypes. Within prostate cancer, emerging evidence suggests that tumor genomics (e.g., DNA, RNA, and epigenetics) can be utilized to inform clinical decision making. In addition to providing discriminatory information about prognosis, it is likely tumor genomics also hold a key in predicting response to oncologic therapies which could be used to further tailor treatment recommendations. Herein we review select literature surrounding the use of tumor genomics within the management of prostate cancer, specifically leaning toward analytically validated and clinically tested genomic biomarkers utilized in radiotherapy and/or adjunctive therapies given with radiotherapy.

Active surveillance in favorable intermediate risk prostate cancer: outstanding questions and controversies.

PURPOSE OF REVIEW: Active surveillance has become the preferred management strategy for patients with low risk prostate cancer, but it is unclear if active surveillance can be safely extended to favorable intermediate risk (FIR) prostate cancer patients. Furthermore, defining a favorable intermediate risk prostate cancer population safe for active surveillance remains elusive due to paucity of high-level data in this population. This article serves to review relevant data, particularly the safety of active surveillance in grade group 2 patients, and what tools are available to aid in selecting a favorable subset of intermediate risk patients. RECENT FINDINGS: Active surveillance studies with long-term data appear to report worsened survival outcomes in intermediate risk patients when compared to those undergoing definitive treatment, but there exists a subset of intermediate risk patients with nearly equivalent outcomes to low risk patients on active surveillance. Tools such as percentage and total length of Gleason pattern 4, tumor volume, prostate specific antigen density, magnetic resonance imaging, and genomic modifiers may help to select a favorable subset of intermediate risk prostate cancer appropriate for active surveillance. SUMMARY: Active surveillance is a viable strategy in select patients with low volume group grade 2 (GG2) prostate cancer. Prospective and retrospective data in the FIR population appear to be mostly favorable in regards to survival outcomes, but there exists some heterogeneity with respect to long-term outcomes in this patient population.

A comprehensive review of methods to study lncRNA-protein interactions in solution.

The long non-coding RNAs (lncRNAs) other than rRNA and tRNA were earlier assumed to be 'junk genomic material'. However, recent advancements in genomics methods have highlighted their roles not only in housekeeping but also in the progression of diseases like cancer as well as viral infections. lncRNAs owing to their length, have both short-range and long-range interactions resulting in complex folded structures that recruit various biomolecules enabling lncRNAs to undertake their various biological functions. Using cell lysate pull-down assays increasing number of lnRNAs-interacting proteins are being identified. These interactions can be further exploited to develop targeted novel therapeutic strategies to inhibit lncRNA-protein interactions. This review attempts to succinctly techniques that can identify and characterize the lnRNAs-protein interactions (i.e. affinity, stoichiometry, and thermodynamics). Furthermore, using other sophisticated biophysical techniques, one can also perform size estimations, and determine low-resolution structures. Since these methods study the biomolecules in solution, large-scale structural observations can be performed in real-time. This review attempts to briefly introduce the readers to biochemical and biophysical techniques, such that they can utilize these methods to obtain a holistic characterization of the biomolecules of interest. Additionally, it should be noted that the use of these methods is not limited to the characterization of the interacting molecules but can also be used to determine the efficacy of the therapeutic molecules to disrupt these interactions.

Cytopathic effect of Vero cells adapted Bangladeshi strain of peste des petits ruminants (PPR) virus in cell culture.

The present study described the cytopathic effect of PPR virus presently being used in serial passages at the level of 60th in Vero cells and infected tissue culture fluid was used in this study as viral inoculum. Vero cells were grown on cover slip & were infected with tissue culture fluid at a fixed multiplicity of infection (MOI) 0.01. The infected cover slip along with control were stained with H&E stain at periodic intervals and cytopathic effect was studied with microscope. The cytopathic effect (CPE) was visible at first from 24 hpi and the Vero cells showed initial cell rounding, aggregation, and syncytial development. Development of inclusion bodies and cell degradation was noticed by 72 hpi. Complete detachment of the cell monolayer was observed by 84 hpi. It is concluded that, development of numerous inclusion bodies are the indication of well adaptation & extensive multiplication of PPRV in Vero cells.

Meta-analysis and systematic review: Prevalence, graft failure, mortality, and post-operative thrombosis in liver transplant recipients with pre-operative portal vein thrombosis.

AIMS: This study seeks to evaluate the association between pre-transplant portal vein thrombosis (PVT) and overall survival, graft failure, waitlist mortality, and post-operative PVT after liver transplantation. METHODS: A conventional pairwise meta-analysis between patients with and without pre-transplant PVT was conducted using hazard ratios or odds ratios where appropriate. RESULTS: Prevalence of preoperative PVT was 11.6% (CI 9.70-13.7%). Pre-operative PVT was associated with increased overall mortality (HR 1.45, 95% CI 1.27-1.65) and graft loss (HR 1.58, 95% CI 1.34-1.85). In particular, grade 3 (HR 1.59, 95% CI 1.00-2.51) and 4 (HR 2.24, 95% CI 1.45-3.45) PVT significantly increased mortality, but not grade 1 or 2 PVT. Patients with PVT receiving living donor (HR 1.54, 95% CI 1.24-1.91) and deceased donor (HR 1.52, 95% CI 1.21-1.92) liver transplantation had increased mortality, with no significant difference between transplant types (P = .13). Furthermore, pre-transplant PVT was associated with higher occurrence of post-transplant PVT (OR 5.06, 95% CI 3.89-6.57). Waitlist mortality was not significantly increased in patients with pre-transplant PVT. CONCLUSION: Graft failure, mortality, and post-operative PVT are more common in pre-transplant PVT patients, especially in grade 3 or 4 PVT. Prophylactic anticoagulation can be considered to reduce re-thrombosis and improve survival.

Protective effect of a first SARS-CoV-2 infection from reinfection: a matched retrospective cohort study using PCR testing data in England.

The duration of immunity after first severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and the extent to which prior immunity prevents reinfection is uncertain and remains an important question within the context of new variants. This is a retrospective population-based matched observational study where we identified the first polymerase chain reaction (PCR) positive of primary SARS-CoV-2 infection case tests between 1 March 2020 and 30 September 2020. Each case was matched by age, sex, upper tier local authority of residence and testing route to one individual testing negative in the same week (controls) by PCR. After a 90-day pre-follow-up period for cases and controls, any subsequent positive tests up to 31 December 2020 and deaths within 28 days of testing positive were identified, this encompassed an essentially vaccine-free period. We used a conditional logistic regression to analyse the results. There were 517 870 individuals in the matched cohort with 2815 reinfection cases and 12 098 first infections. The protective effect of a prior SARS-CoV-2 PCR-positive episode was 78% (odds ratio (OR) 0.22, 0.21-0.23). Protection rose to 82% (OR 0.18, 0.17-0.19) after a sensitivity analysis excluded 933 individuals with a first test between March and May and a subsequent positive test between June and September 2020. Amongst individuals testing positive by PCR during follow-up, reinfection cases had 77% lower odds of symptoms at the second episode (adjusted OR 0.23, 0.20-0.26) and 45% lower odds of dying in the 28 days after reinfection (adjusted OR 0.55, 0.42-0.71). Prior SARS-CoV-2 infection offered protection against reinfection in this population. There was some evidence that reinfections increased with the alpha variant compared to the wild-type SARS-CoV-2 variant highlighting the importance of continued monitoring as new variants emerge.

Imaging Cerebral Energy Metabolism in Healthy Infants.

Broadband near-infrared spectroscopy (bNIRS) has the potential to provide non-invasive measures of cerebral haemodynamic changes alongside changes in cellular oxygen utilisation through the measurement of mitochondrial enzyme cytochrome-c-oxidase (oxCCO). It therefore provides the opportunity to explore brain function and specialisation, which remains largely unexplored in infancy. We used bNIRS to measure changes in haemodynamics and changes in oxCCO in 4-to-7-month-old infants over the occipital and right temporal and parietal cortices in response to social and non-social visual and auditory stimuli. Changes in concentration of oxygenated-haemoglobin (Δ[HbO2]), deoxygenated haemoglobin (Δ[HHb]) and change in the oxidation state of oxCCO (Δ[oxCCO]) were calculated using changes in attenuation of light at 120 wavelengths between 780 and900 nm, using the UCLn algorithm. For 4 infants, the attenuation changes in a subset of wavelengths were used to perform image reconstruction, in an age-matched infant model, for channels over the right parietal and temporal cortices, using a multispectral approach which allows direct reconstruction of concentration change data. The volumetric reconstructed images were mapped onto the cortical surface to visualise the reconstructed changes in concentration of HbO2 and HHb and changes in metabolism for both social and non-social stimuli. Spatially localised activation was observed for Δ[oxCCO] and Δ[HbO2] over the temporo-parietal region, in response to the social stimulus. This study provides the first reconstructed images of changes in metabolism in healthy, awake infants.

Safety of simultaneous bilateral intravitreal versus unilateral anti-vasculo-endothelial growth factors injection in an operating room setting.

Objectives: Chorioretinal diseases requiring the use of anti-vascular endothelial growth (anti-VEGF) injections often occur in both eyes simultaneously. This can necessitate injecting both eyes together rather than one eye at a time. The purpose of the study was to determine whether simultaneous bilateral intravitreal injections of anti-VEGF agents are safe when administered in an operation theatre setting. Methods: Retrospective review of data was conducted. Single center study conducted in a tertiary care hospital in Karachi Pakistan. Approximately 30,000 eyes that received anti-VEGF injection during a 10-year study period were included (March 2008-February 2018). Patients who were lost to follow up prior to completion of treatment were excluded. Consecutive sampling technique was employed. The patients who received bilateral anti-VEGF injections were analysed separately from the ones who received unilateral injections. All injections were administered in operating theatre setting. The rate of endophthalmitis was measured in each group. Results: A total of 30,258 injections were administered of which 15,338 were bilateral injections. Four cases (4/30,258, 0.013%) of endophthalmitis occurred during the study period. Only one case (1/15,338, 0.0065%) of endophthalmitis occurred after the administration of simultaneous bilateral anti-VEGF injections. Conclusions: Administration of simultaneous bilateral anti-VEGF injections was safe in our population.

Guar gum based hydrogel as controlled micronutrient delivery system: Mechanism and kinetics of boron release for agricultural applications.

A boron loaded super-absorbent hydrogel (BLSAH) was developed through in situ incorporation of boron (B) in a guar gum-based hydrogel and characterized with FTIR, thermo-gravimetric analysis (TGA), scanning electron microscopy (SEM), and swelling studies, showing maximum absorption up to 356 g/g. The release pattern of B from the BLSAH and its kinetics was studied in water as well as soil. The B release pattern of the BLSAH was also compared with the commercial B fertilizer, boronated single super phosphate (bSSP). The BLSAH, following the Fickian mechanism, released 38% B, as compared with 51% of the bSSP, during the incubation period of 30 days in soil. The half-life period for the BLSAH (96.25 days) in soil was almost triple that of the bSSP's half-life (33.32 days), which is indicative of the slow and controlled release of B from the BLSAH. Thus, owing to its sustained nutrient release ability, the synthesized BLSAH exhibited wide potential for applications in agriculture sector.

Role of multiparametric prostate MRI in the management of prostate cancer.

INTRODUCTION: Prostate cancer has traditionally been diagnosed by an elevation in PSA or abnormal exam leading to a systematic transrectal ultrasound (TRUS)-guided biopsy. This diagnostic pathway underdiagnoses clinically significant disease while over diagnosing clinically insignificant disease. In this review, we aim to provide an overview of the recent literature regarding the role of multiparametric MRI (mpMRI) in the management of prostate cancer. MATERIALS AND METHODS: A thorough literature review was performed using PubMed to identify articles discussing use of mpMRI of the prostate in management of prostate cancer. CONCLUSION: The incorporation of mpMRI of the prostate addresses the shortcomings of the prostate biopsy while providing several other advantages. mpMRI allows some men to avoid an immediate biopsy and permits visualization of areas likely to harbor clinically significant cancer prior to biopsy to facilitate use of MR-targeted prostate biopsies. This allows for reduction in diagnosis of clinically insignificant disease as well as improved detection and better characterization of higher risk cancers, as well as the improved selection of patients for active surveillance. In addition, mpMRI can be used for selection and monitoring of patients for active surveillance and treatment planning during surgery and focal therapy.

Predicting development of ipilimumab-induced hypophysitis: utility of T4 and TSH index but not TSH.

PURPOSE: Ipilimumab, a monoclonal antibody inhibiting CLTA-4, is an established treatment in metastatic melanoma, either alone or in combination with nivolumab, and results in immune mediated adverse events, including endocrinopathy. Hypophysitis is one of the most common endocrine abnormalities. An early recognition of hypophysitis may prevent life threatening consequences of hypopituitarism; therefore, biomarkers to predict which patients will develop hypophysitis would have clinical utility. Recent studies suggested that a decline in TSH may serve as an early marker of IH. This study was aimed at assessing the utility of thyroid function tests in predicting development of hypophysitis. METHODS: A retrospective cohort study was performed for all patients (n = 308) treated with ipilimumab either as a monotherapy or in combination with nivolumab for advanced melanoma at the Royal Marsden Hospital from 2010 to 2016. Thyroid function tests, other pituitary function tests and Pituitary MRIs were used to identify those with hypophysitis. RESULTS AND CONCLUSIONS: Ipilimumab-induced hypophysitis (IH) was diagnosed in 25 patients (8.15%). A decline in TSH was observed in hypophysitis cohort during the first three cycles but it did not reach statistical significance (P = 0.053). A significant fall in FT4 (P < 0.001), TSH index (P < 0.001) and standardised TSH index (P < 0.001) prior to cycles 3 and 4 in hypophysitis cohort was observed. TSH is not useful in predicting development of IH. FT4, TSH index and standardised TSH index may be valuable but a high index of clinical suspicion remains paramount in early detection of hypophysitis.

Clinical manifestations and outcomes of COVID-19 in the paediatric population: a systematic review.

OBJECTIVE: Coronavirus disease 2019 (COVID-19), the respiratory illness caused by severe acute respiratory syndrome coronavirus 2, has affected hundreds of thousands of people. We aim to report the distribution of cases, prevalence, and clinical, radiological, and laboratory signs and outcomes of COVID-19 in paediatric patients. Moreover, we intend to evaluate neonatal clinical outcomes. Hence, our age range of interest is 0 to 19 years. METHODS: A systematic literature review was conducted using the Medline database to identify papers published between 1 December 2019 and 9 April 2020 on COVID-19. RESULTS: The search identified 27 relevant scientific papers and letters. The review showed that the prevalence of COVID-19 in the paediatric population accounts for a small percentage of patients, whose clinical signs and symptoms are often milder than those of adults. Despite better prognosis and low mortality in children, the disease can progress to severe pneumonia in some cases, especially in the presence of co-morbidities. Children are likely to become a hidden source of infection because of their atypical presentation, and they may play a role in community transmission, leading to unfavourable outcomes. There is little evidence about intrauterine vertical transmission. As no vaccine or specific antiviral is currently available, management plans include supportive treatment. CONCLUSION: As compared with that in adults, the presentation of COVID-19 in children is mild and has a better prognosis. Sufficient evidence regarding the probability of intrauterine vertical transmission could not be found, and further studies need to be conducted to establish this relationship.

Incidence, patterns, risk factors, and histopathological findings of liver injury in coronavirus disease 2019 (COVID-19): a scoping review.

BACKGROUND: Coronavirus disease 2019 (COVID-19) exhibits many extrapulmonary manifestations, including liver injury. This scoping review aimed to provide insight into the incidence, patterns, risk factors, histopathological findings, and relationship with disease severity of COVID-19-associated liver injury. Furthermore, we identified existing gaps in the research on the hepatic manifestations of COVID-19 and highlighted areas for future investigations. METHODS: A scoping review was conducted following the methodological framework suggested by Arksey and O'Mallay. Five online databases, along with grey literature, were searched for articles published until 22 May 2020, and we included 62 articles in the review. The research domains, methodological characteristics, and key conclusions were included in the analysis. RESULTS: Retrospective observational studies comprised more than one third (41.9%) of the included publications, and 77.8% were conducted on living patients. The incidence of liver injury varied widely across the studies (4.8%-78%), and liver injury was frequently associated with severe COVID-19. We identified the following risk factors for liver injury: male sex, lymphopoenia, gastrointestinal involvement, old age, increased neutrophil count, and the use of hepatotoxic drugs. Histopathological findings indicate that COVID-19 has direct cytopathic effects and causes liver function test derangements secondary to inflammation, hypoxia, and vascular insult. CONCLUSIONS: Liver injury following COVID-19 infection is common and primarily hepatocellular, with a greater elevation of aspartate aminotransferase tahn of alanine aminotransferase. However, the evidence regarding hepatic failure secondary to COVID-19 is insufficient. Standardised criteria to diagnose liver injury need to be devised. Current use of hepatotoxic drugs necessitates close monitoring of liver function.

Bioinformatic Analysis of Structure and Function of LIM Domains of Human Zyxin Family Proteins.

Members of the human Zyxin family are LIM domain-containing proteins that perform critical cellular functions and are indispensable for cellular integrity. Despite their importance, not much is known about their structure, functions, interactions and dynamics. To provide insights into these, we used a set of in-silico tools and databases and analyzed their amino acid sequence, phylogeny, post-translational modifications, structure-dynamics, molecular interactions, and functions. Our analysis revealed that zyxin members are ohnologs. Presence of a conserved nuclear export signal composed of LxxLxL/LxxxLxL consensus sequence, as well as a possible nuclear localization signal, suggesting that Zyxin family members may have nuclear and cytoplasmic roles. The molecular modeling and structural analysis indicated that Zyxin family LIM domains share similarities with transcriptional regulators and have positively charged electrostatic patches, which may indicate that they have previously unanticipated nucleic acid binding properties. Intrinsic dynamics analysis of Lim domains suggest that only Lim1 has similar internal dynamics properties, unlike Lim2/3. Furthermore, we analyzed protein expression and mutational frequency in various malignancies, as well as mapped protein-protein interaction networks they are involved in. Overall, our comprehensive bioinformatic analysis suggests that these proteins may play important roles in mediating protein-protein and protein-nucleic acid interactions.

Aminoglycoside-mediated promotion of translation readthrough occurs through a non-stochastic mechanism that competes with translation termination.

Attempts have been made to treat nonsense-associated genetic disorders by chemical agents and hence an improved mechanistic insight into the decoding of readthrough signals is essential for the identification and characterisation of factors for the treatment of these disorders. To identify either novel compounds or genes that modulate translation readthrough, we have employed dual reporter-based high-throughput screens that use enzymatic and fluorescence activities and screened bioactive National Institute of Neurological Disease Syndrome (NINDS) compounds (n = 1000) and siRNA (n = 288) libraries. Whilst siRNAs targeting kinases such as CSNK1G3 and NME3 negatively regulate readthrough, neither the bioactive NINDS compounds nor PTC124 promote readthrough. Of note, PTC124 has previously been shown to promote readthrough. Furthermore, the impacts of G418 on the components of eukaryotic selenocysteine incorporation machinery have also been investigated. The selenocysteine machinery decodes the stop codon UGA specifying selenocysteine in natural selenoprotein genes. We have found that the eukaryotic SelC gene promotes the selenocysteine insertion sequence (SECIS)-mediated readthrough but inhibits the readthrough activity induced by G418. We have previously reported that SECIS-mediated readthrough at UGA codons follows a non-processive mechanism. Here, we show that G418-mediated promotion of readthrough also occurs through a non-processive mechanism which competes with translation termination. Based on our observations, we suggest that proteins generated through a non-processive mechanism may be therapeutically beneficial for the resolution of nonsense-associated genetic disorders.

Randomized prospective trial of fractionated stereotactic radiosurgery with chemotherapy versus chemotherapy alone for bevacizumab-resistant high-grade glioma.

PURPOSE: Outcomes for patients with recurrent high-grade glioma (HGG) progressing on bevacizumab (BEV) are dismal. Fractionated stereotactic radiosurgery (FSRS) has been shown to be feasible and safe when delivered in this setting, but prospective evidence is lacking. This single-institution randomized trial compared FSRS plus BEV-based chemotherapy versus BEV-based chemotherapy alone for BEV-resistant recurrent malignant glioma. MATERIALS AND METHODS: HGG patients on BEV with tumor progression after 2 previous treatments were randomized to 1) FSRS plus BEV-based chemotherapy or 2) BEV-based chemotherapy with irinotecan, etoposide, temozolomide, or carboplatin. FSRS was delivered as 32 Gy (8 Gy × 4 fractions within 2 weeks) to the gross target volume and 24 Gy (6 Gy × 4 fractions) to the clinical target volume (fluid-attenuated inversion recovery abnormality). The primary endpoints were local control (LC) at 2 months and progression-free survival (PFS). RESULTS: Of the 35 patients enrolled, 29 had glioblastoma (WHO IV) and 6 had anaplastic glioma (WHO III). The median number of prior recurrences was 3. Patients treated with FSRS had significantly improved PFS (5.1 vs 1.8 months, P < .001) and improved LC at 2 months (82% [14/17] vs 27% [4/15], P = .002). The overall median survival was 6.6 months (7.2 months with FSRS vs 4.8 months with chemotherapy alone, P = .11). CONCLUSIONS: FSRS combined with BEV-based chemotherapy in recurrent HGG patients progressing on BEV is feasible and improves LC and PFS when compared to treatment with BEV-based chemotherapy alone.