Ultrasound-guided Brachytherapy for Cervix Cancer

Radiotherapy and brachytherapy are the definitive treatments for locally advanced cervix cancer. The use of soft-tissue imaging, particularly magnetic resonance imaging, has enhanced their effectiveness and improved clinical outcomes. However, the use of magnetic resonance imaging is largely restricted to well-resourced centres in both the first and developing world and remains elusive to many less advantaged centres, particularly those in areas with a high burden of cervix cancer. Ultrasound is an accessible, affordable and accurate imaging modality that can be used throughout the brachytherapy procedure. Ultrasound is primarily used to ensure safe insertion of the applicator but can also be used to guide planning. The methods used to utilise ultrasound images for planning are described. Ultrasound is particularly useful as a verification aid to confirm applicator placement after patients are moved and transferred around the radiotherapy department. It can also be used to verify the dimensions of treatment volumes over the course of brachytherapy. There is a crucial unmet need for an accessible economical soft-tissue imaging modality in cervical brachytherapy. Ultrasound has the potential to meet this need.

ICEPAC: A phase II multicenter study of avelumab combined with stereotactic ablative body radiotherapy (SABR) in metastatic castration-resistant prostate cancer (mCRPC)

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Background: Studies investigating immune checkpoint inhibitors (ICI) in mCRPC have produced modest results. Radiation therapy may be synergistic with ICIs. We hypothesised that SABR would enhance anti-tumour activity of PD-L1 inhibitor avelumab in patients (pts) with progressive mCRPC. Methods: This phase II, single arm, multicentre study enrolled mCRPC pts following progression on ≥1 novel androgen receptor-directed therapy. Up to two lines of prior taxane chemotherapy were permitted. Pts received avelumab 10mg/kg IV q2weeks for a total of 24 weeks (12 cycles). A single fraction of 20Gy SABR was administered to 1-2 disease sites within five days prior to first and second doses of avelumab. Primary endpoint was disease control rate (DCR); secondary endpoints were PSA response (PSA50), overall response rate (ORR), radiographic progression-free survival (rPFS), overall survival (OS) and safety. Radiographic disease assessment (CT and bone scintigraphy) was performed after cycles 6 and 12 of avelumab treatment. Following enrolment of 14 pts, a protocol amendment allowed avelumab beyond 12 cycles in pts with disease control at 24 weeks. Results: Thirty-one pts were enrolled, with 30 evaluable for the primary endpoint. Median follow-up was 18 months (mo). Pt characteristics: median age 71 years (IQR 64-75), bone-only disease 42%, visceral disease 16%, prior taxane chemotherapy 84%, treatment with both abiraterone and enzalutamide 13%. Seventy metastatic sites received SABR, most frequently to bone (90%) and soft tissue (29%) disease. Avelumab was given as second-line, third-line and fourth- or greater line systemic therapy in 29%, 42% and 29% of pts, respectively. Median cycles of avelumab administered was 9 (IQR 5-13). DCR (95% CI) was 50% (31-69) and 60% (32-84) in all-comers and soft tissue disease subgroup, respectively. Following protocol amendment, 7/17 pts (41%) received avelumab beyond 12 cycles. Incidence of grade 3-4 treatment-related AEs was 16% (no grade 5 events), with three pts requiring oral/IV corticosteroid therapy. Conclusions: Avelumab with SABR demonstrated durable disease control in treatment-refractory mCRPC with an acceptable toxicity profile. This combination warrants further investigation. Clinical trial information: ACTRN12618000954224. [Table: see text]

A preliminary evaluation of the circulating leptin/adiponectin ratio in dogs with pituitary-dependent hyperadrenocorticism and concurrent diabetes mellitus

Leptin and adiponectin are thought to modulate insulin sensitivity and pancreatic β-cell function, but there is limited information regarding the adipokine status of hyperglycemic dogs with hyperadrenocorticism. This study aimed to determine whether alterations in the leptin/adiponectin ratio, insulin sensitivity, and/or pancreatic β-cell function are associated with diabetes mellitus (DM) in dogs with pituitary-dependent hyperadrenocorticism (PDH). A total of 48 client-owned dogs were included in this prospective observational study: 20 dogs with PDH (10 normoglycemic and 10 with DM), 15 dogs with DM, and 13 healthy dogs. The serum concentrations of leptin, adiponectin, resistin, interleukin (IL)-1β, IL-6, IL-10, IL-18, and tumor necrosis factor (TNF)-α were measured, and homeostatic model assessment indices (HOMAs) were calculated and compared among the groups. Serum leptin was significantly higher in PDH dogs with and without DM than in healthy and DM dogs, and it was lower in DM dogs than in PDH dogs without DM. Serum adiponectin was significantly lower in PDH dogs with DM than in healthy and PDH dogs, and it was significantly lower in DM dogs than in healthy dogs. Serum IL-10 was significantly higher in PDH dogs with DM than in healthy and PDH dogs without DM. The leptin/adiponectin ratio was significantly higher in PDH dogs with DM than in normoglycemic PDH dogs. Serum IL-6 concentrations were significantly higher in DM dogs than in healthy dogs. Serum IL-1β concentration was significantly higher in DM dogs than in healthy dogs and PDH dogs with DM and without DM. Serum TNF-α and IL-18 concentrations were not different among groups. The HOMA_{β-cell function} was significantly lower in PDH dogs with DM than in normoglycemic PDH dogs, while HOMA_{insulin sensitivity} was significantly lower in PDH dogs with DM than in healthy dogs. These results suggest that adipokine dysregulation, a reduction in insulin sensitivity, and a further impairment in pancreatic β-cell function might predispose PDH dogs to DM. Further longitudinal study will be necessary to confirm this result.

Glycosylation of Serum Clusterin in Wild-Type Transthyretin-Associated (ATTRwt) Amyloidosis: A Study of Disease-Associated Compositional Features Using Mass Spectrometry Analyses

Wild-type transthyretin-associated (ATTRwt) amyloidosis is an age-related disease that causes heart failure in older adults. This disease frequently features cardiac amyloid fibril deposits that originate from dissociation of the tetrameric protein, transthyretin (TTR). Unlike hereditary TTR (ATTRm) amyloidosis, where amino acid replacements destabilize the native protein, in ATTRwt amyloidosis, amyloid-forming TTR lacks protein sequence alterations. The initiating cause of fibril formation in ATTRwt amyloidosis is unclear, and thus, it seems plausible that other factors are involved in TTR misfolding and unregulated accumulation of wild-type TTR fibrils. We believe that clusterin (CLU, UniProtKB P10909), a plasma circulating glycoprotein, plays a role in the pathobiology of ATTRwt amyloidosis. Previously, we have suggested a role for CLU in ATTRwt amyloidosis based on our studies showing that (1) CLU codeposits with non-native TTR in amyloid fibrils from ATTRwt cardiac tissue, (2) CLU interacts only with non-native (monomeric and aggregated) forms of TTR, and (3) CLU serum levels in patients with ATTRwt are significantly lower compared to healthy controls. In the present study, we provide comprehensive detail of compositional findings from mass spectrometry analyses of amino acid and glycan content of CLU purified from ATTRwt and control sera. The characterization of oligosaccharide content in serum CLU derived from patients with ATTRwt amyloidosis is novel data. Moreover, results comparing CLU oligosaccharide variations between patient and healthy controls are original and provide further evidence for the role of CLU in ATTRwt pathobiology, possibly linked to disease-specific structural features that limit the chaperoning capacity of CLU.

Measuring Site-specific Glycosylation Similarity between Influenza a Virus Variants with Statistical Certainty

Influenza A virus (IAV) mutates rapidly, resulting in antigenic drift and poor year-to-year vaccine effectiveness. One challenge in designing effective vaccines is that genetic mutations frequently cause amino acid variations in IAV envelope protein hemagglutinin (HA) that create new N-glycosylation sequons; resulting N-glycans cause antigenic shielding, allowing viral escape from adaptive immune responses. Vaccine candidate strain selection currently involves correlating antigenicity with HA protein sequence among circulating strains, but quantitative comparison of site-specific glycosylation information may likely improve the ability to design vaccines with broader effectiveness against evolving strains. However, there is poor understanding of the influence of glycosylation on immunodominance, antigenicity, and immunogenicity of HA, and there are no well-tested methods for comparing glycosylation similarity among virus samples. Here, we present a method for statistically rigorous quantification of similarity between two related virus strains that considers the presence and abundance of glycopeptide glycoforms. We demonstrate the strength of our approach by determining that there was a quantifiable difference in glycosylation at the protein level between WT IAV HA from A/Switzerland/9715293/2013 (SWZ13) and a mutant strain of SWZ13, even though no N-glycosylation sequons were changed. We determined site-specifically that WT and mutant HA have varying similarity at the glycosylation sites of the head domain, reflecting competing pressures to evade host immune response while retaining viral fitness. To our knowledge, our results are the first to quantify changes in glycosylation state that occur in related proteins of considerable glycan heterogeneity. Our results provide a method for understanding how changes in glycosylation state are correlated with variations in protein sequence, which is necessary for improving IAV vaccine strain selection. Understanding glycosylation will be especially important as we find new expression vectors for vaccine production, as glycosylation state depends greatly on the host species.

Complexity and ultrastructure of infectious extracellular vesicles from cells infected by non-enveloped virus

Enteroviruses support cell-to-cell viral transmission prior to their canonical lytic spread of virus. Poliovirus (PV), a prototype for human pathogenic positive-sense RNA enteroviruses, and picornaviruses in general, transport multiple virions en bloc via infectious extracellular vesicles, 100~1000 nm in diameter, secreted from host cells. Using biochemical and biophysical methods we identify multiple components in secreted microvesicles, including mature PV virions; positive-sense genomic and negative-sense replicative, template viral RNA; essential viral replication proteins; and cellular proteins. Using cryo-electron tomography, we visualize the near-native three-dimensional architecture of secreted infectious microvesicles containing both virions and a unique morphological component that we describe as a mat-like structure. While the composition of these mat-like structures is not yet known, based on our biochemical data they are expected to be comprised of unencapsidated RNA and proteins. In addition to infectious microvesicles, CD9-positive exosomes released from PV-infected cells are also infectious and transport virions. Thus, our data show that, prior to cell lysis, non-enveloped viruses are secreted within infectious vesicles that also transport viral unencapsidated RNAs, viral and host proteins. Understanding the structure and function of these infectious particles helps elucidate the mechanism by which extracellular vesicles contribute to the spread of non-enveloped virus infection.

Multi-task learning sparse group lasso: a method for quantifying antigenicity of influenza A(H1N1) virus using mutations and variations in glycosylation of Hemagglutinin

BACKGROUND

In addition to causing the pandemic influenza outbreaks of 1918 and 2009, subtype H1N1 influenza A viruses (IAVs) have caused seasonal epidemics since 1977. Antigenic property of influenza viruses are determined by both protein sequence and N-linked glycosylation of influenza glycoproteins, especially hemagglutinin (HA). The currently available computational methods are only considered features in protein sequence but not N-linked glycosylation.

RESULTS

A multi-task learning sparse group least absolute shrinkage and selection operator (LASSO) (MTL-SGL) regression method was developed and applied to derive two types of predominant features including protein sequence and N-linked glycosylation in hemagglutinin (HA) affecting variations in serologic data for human and swine H1N1 IAVs. Results suggested that mutations and changes in N-linked glycosylation sites are associated with the rise of antigenic variants of H1N1 IAVs. Furthermore, the implicated mutations are predominantly located at five reported antibody-binding sites, and within or close to the HA receptor binding site. All of the three N-linked glycosylation sites (i.e. sequons NCSV at HA 54, NHTV at HA 125, and NLSK at HA 160) identified by MTL-SGL to determine antigenic changes were experimentally validated in the H1N1 antigenic variants using mass spectrometry analyses. Compared with conventional sparse learning methods, MTL-SGL achieved a lower prediction error and higher accuracy, indicating that grouped features and MTL in the MTL-SGL method are not only able to handle serologic data generated from multiple reagents, supplies, and protocols, but also perform better in genetic sequence-based antigenic quantification.

CONCLUSIONS

In summary, the results of this study suggest that mutations and variations in N-glycosylation in HA caused antigenic variations in H1N1 IAVs and that the sequence-based antigenicity predictive model will be useful in understanding antigenic evolution of IAVs.

Atlantoaxial bands in small breed dogs: influence of external pressure by the endotracheal tube tie

OBJECTIVES

To determine the prevalence of dorsal cervical spinal compression in a population of dogs susceptible to caudal occipital dysplasia. To determine whether endotracheal tube ties iatrogenically alter the dorsal compression ratio in the atlantoaxial region.

MATERIALS AND METHODS

Prospective, randomised, controlled, cross-over, blinded cohort study of dogs weighing <15 kg and presenting for neurologic signs localised to the cervical region. In mid-sagittal T2-weighted MR images, dorsal cervical compression and cerebellar compression were evaluated. Dorsal cervical compression ratios were calculated and compared to determine the effect of the endotracheal tube tie on the atlantoaxial region depending on whether dogs were in extended or flexed neck position.

RESULTS

Prevalence of dorsal cervical spinal compression consistent with an atlantoaxial band was 32/44 (73%) dogs without tie pressure and 37/44 (84%) dogs with tie pressure. Significantly higher compression ratios were found with tie placement over the craniocervical region. Dorsal compression ratios of dogs with cerebellar compression were significantly greater than those without it.

CLINICAL SIGNIFICANCE

The location of the endotracheal tube tie can influence interpretation of MR images of the craniocervical region of small breed dogs. These breeds more often had greater dorsal cervical spinal compression with tie pressure, especially when they had cerebellar compression.