Abstract P1-15-11: Predicting pathological complete response (pCR) to neoadjuvant chemotherapy (NACT) based on pre- and post-NACT digital mammography and digital breast tomosynthesis findings

Background: In invasive breast cancer patients being treated with neoadjuvant chemotherapy (NACT), achieving pathological complete response (pCR) is a useful goal of treatment. Monitoring response to NACT and predicting pCR is helpful in planning further therapy and providing robust prognostic information. Digital mammography (DM) and additional digital breast tomosynthesis (DBT) features are important tell-tales of tumor characteristics and behaviour. Following NACT, the mammographic features- both DM and DBT- of responding tumors can vary considerably. In this prospective study, we correlated the DM and DBT features of pre-NACT and post-NACT mammograms to investigate if these can reliably predict pCR to NACT.

Methods: Following approval by institutional ethics committee, starting January 2016, 200 consecutive invasive breast carcinoma patients (mean age 51.2 years, all palpable breast masses) undergoing diagnostic breast imaging had their DM and DBT reviewed by two radiologists independently, who were blinded of the cyto/histology and the original DM and DBT reporting. Of these, 47 patients who were treated with NACT and had pre- and post-NACT DM and DBT were recruited. After a core-biopsy, radio-opaque marker(s) were placed in tumor core/margin. The pre- and post-NACT DM and DBT findings were compared and correlated with the extent of response of the primary breast tumor to NACT. DM and DBT characteristics predictive of (in-breast) pCR of index breast lesion were identified.

Results: Of the 47 patients who underwent NACT, 44 received both anthracycline and taxane, and 3 received only an anthracycline based combination chemotherapy. Twelve patients underwent breast conservative surgery and the remaining underwent mastectomy. pCR was seen in 17 (36.2%) patients based on the surgical specimen histology. On clinical examination, 19 (40.4%) patients had clinical complete response (cCR) of the breast tumor, 11 (64.7%) of whom had pCR as well. Five patients had radiological complete response (rCR, no breast lesion visualised on post-NACT imaging)- 2 patients on DM alone, 2 patients on DBT alone, and one patient on both DM and DBT. Radio-opaque clips had some obscuring effects in 3 of these 5 patients, especially on DBT, in form of reduced visibility of breast lesion on DBT, c.w. corresponding DM images. All 5 patients with rCR had pCR (sensitivity=29.4%, specificity=100%), in contrast to only 11 (57.9%) patients with cCR having pCR. Patients with pCR had benign appearing (forced Bi-RADS 2 and 3) lesions on mammography more commonly on DM (p<0.001) than on DBT (p=0.042) (41.2% vs 23.5%). Post NACT lesion morphology varied significantly between patients with and without pCR on DM (p=0.038) but not on DBT (p=0.182). Pre-NACT forced Bi-RADS score, lesion morphology or margin characteristics on DM and DBT did not vary significantly amongst patients with and without pCR.

Conclusions: Post-NACT DM and DBT features can predict pCR with high specificity but with low sensitivity. Pre-NACT DM and DBT features did not reliably predict response to NACT, and pCR in this study. DM may be better than DBT for assessing response to NACT in the presence of radio-opaque markers/clips.

Citation Format: Agarwal G, Sonthineni C, Mohindra N, Jain N, Neyaz Z, Agrawal V, Krishnani N, Maylivahnan S, Mishra A, Lal P. Predicting pathological complete response (pCR) to neoadjuvant chemotherapy (NACT) based on pre- and post-NACT digital mammography and digital breast tomosynthesis findings [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-15-11.

Core-clad phosphate glass fibers for biosensing

Recently, a phosphate glass with composition 20 CaO-20 SrO-10 Na₂O-50 P₂O₅ (mol%) was found to have good potential as a biomaterial and to possess thermal properties suitable for fiber drawing. This study opened the path towards the development of fully bioresorbable fibers promising for biosensing. In the past, this phosphate glass with CeO₂ was found to increase the refractive index and the glass stability. Therefore, a new SrO-containing glass was prepared with 1 mol% of CeO₂ and core fibers were drawn from it. A core-clad fiber was also processed, where the core was a Ce-doped glass and the clad undoped, to allow for total internal reflection. The mechanical properties of the core and core-clad fibers are discussed as a function of immersion time in TRIS-buffer solution. Finally, a sensing region was created, in the core-clad fiber, by etching the cladding using phosphoric acid. Then, the change in light transmission, upon immersion in TRIS-buffer solution, was quantified to assess the potential use of the novel core-clad fiber as a biosensor. Upon immersion in TRIS, the core-clad fiber was found to guide light effectively and to maintain a tensile strength of ~150-200 MPa up to 6 weeks in TRIS, clearly showing that this fiber has potential as a biosensing device.

Critical care usage after major gastrointestinal and liver surgery: a prospective, multicentre observational study

BACKGROUND

Patient selection for critical care admission must balance patient safety with optimal resource allocation. This study aimed to determine the relationship between critical care admission, and postoperative mortality after abdominal surgery.

METHODS

This prespecified secondary analysis of a multicentre, prospective, observational study included consecutive patients enrolled in the DISCOVER study from UK and Republic of Ireland undergoing major gastrointestinal and liver surgery between October and December 2014. The primary outcome was 30-day mortality. Multivariate logistic regression was used to explore associations between critical care admission (planned and unplanned) and mortality, and inter-centre variation in critical care admission after emergency laparotomy.

RESULTS

Of 4529 patients included, 37.8% (n=1713) underwent planned critical care admissions from theatre. Some 3.1% (n=86/2816) admitted to ward-level care subsequently underwent unplanned critical care admission. Overall 30-day mortality was 2.9% (n=133/4519), and the risk-adjusted association between 30-day mortality and critical care admission was higher in unplanned [odds ratio (OR): 8.65, 95% confidence interval (CI): 3.51-19.97) than planned admissions (OR: 2.32, 95% CI: 1.43-3.85). Some 26.7% of patients (n=1210/4529) underwent emergency laparotomies. After adjustment, 49.3% (95% CI: 46.8-51.9%, P<0.001) were predicted to have planned critical care admissions, with 7% (n=10/145) of centres outside the 95% CI.

CONCLUSIONS

After risk adjustment, no 30-day survival benefit was identified for either planned or unplanned postoperative admissions to critical care within this cohort. This likely represents appropriate admission of the highest-risk patients. Planned admissions in selected, intermediate-risk patients may present a strategy to mitigate the risk of unplanned admission. Substantial inter-centre variation exists in planned critical care admissions after emergency laparotomies.

Antibacterial properties of human beta defensin-3 derivative: CHRG01

Antibiotic resistance in bacteria is a major health concern. Antimicrobial peptides (AMPs) are a class of peptides that are efficient in killing most microbes yet development of resistance to AMPs is rare. However, complex secondary and tertiary structures and difficulties in isolating AMPs have limited their use as antibiotics. It has been demonstrated earlier that small peptides derived from human β defensin-3 (HBD-3) also show antibacterial activity. Here, we perform a detailed characterization of the antibacterial activity of one such derivative: CHRG01. While HBD-3 has 45 amino acids with three disulphide bonds and a β-sheet folded structure, CHRG01 has only 14 amino acids with the cysteine residues replaced by serine. The antibacterial nature of CHRG01 was studied using scanning electron microscopy (SEM), confocal microscopy, circular dichroism (CD) and small-angle X-ray scattering (SAXS). CD data show that CHRG01 is random coiled in solution. SEM and confocal studies show that the mode of action of CHRG01 is pore forming. SAXS studies show that CHRG01 induces a negative Gaussian curvature, the type of curvature needed for pore formation. The above results show that CHRG01, a small peptide without any complex structure, is capable of killing bacteria by permeabilizing their outer membranes.

Evaluation of antiviral activity of Ocimum sanctum and Acacia arabica leaves extracts against H9N2 virus using embryonated chicken egg model

BACKGROUND

In the view of endemic avian influenza H9N2 infection in poultry, its zoonotic potential and emergence of antiviral resistance, two herbal plants, Ocimum sanctum and Acacia arabica, which are easily available throughout various geographical locations in India were taken up to study their antiviral activity against H9N2 virus. We evaluated antiviral efficacy of three different extracts each from leaves of O. sanctum (crude extract, terpenoid and polyphenol) and A. arabica (crude extract, flavonoid and polyphenol) against H9N2 virus using in ovo model.

METHODS

The antiviral efficacy of different leaves extracts was systematically studied in three experimental protocols viz. virucidal (dose-dependent), therapeutic (time-dependent) and prophylactic (dose-dependent) activity employing in ovo model. The maximum non-toxic concentration of each herbal extracts of O. sanctum and A. arabica in the specific pathogen free embryonated chicken eggs was estimated and their antiviral efficacy was determined in terms of reduction in viral titres, measured by Haemagglutination (HA) and real time quantitative reverse transcription polymerase chain reaction (RT-qPCR) assays.

RESULTS

All the extracts of O. sanctum (crude extract, terpenoid and polyphenol) and A. arabica (crude extract, flavonoid and polyphenol) showed significant virucidal activity, however, crude extract _ocimum and terpenoid _ocimum showed highly significant to significant (p < 0.001-0.01) decrease in virus genome copy numbers with lowest dose tested. Similarly, therapeutic effect was observed in all three extracts of O. sanctum in comparison to the virus control, nevertheless, crude extract _ocimum and terpenoid _ocimum maintained this effect for longer period of time (up to 72 h post-incubation). None of the leaves extracts of A. arabica had therapeutic effect at 24 and 48 h post-incubation, however, only the crude extract _acacia and polyphenol _acacia showed delayed therapeutic effect (72 h post-inoculation). Prophylactic potential was observed in polyphenol _acacia with highly significant antiviral activity compared to virus control (p < 0.001).

CONCLUSIONS

The crude extract and terpenoid isolated from the leaves of O. sanctum and polyphenol from A. arabica has shown promising antiviral properties against H9N2 virus. Future investigations are necessary to formulate combinations of these compounds for the broader antiviral activity against H9N2 viruses and evaluate them in chickens.

Evaluation of two internal fixation techniques for mandibular parasymphyseal fractures comparing conventional titanium miniplates with customised titanium CRB omega miniplates: a prospective study

Our aim was to compare the efficacy and outcome of customised, titanium, CRB (Chandrashekhar Rushiji Bande), omega miniplates with those of conventional titanium miniplates in the management of parasymphyseal fractures of the mandible, with or without involvement of the mental nerve, after clinical and radiographic evaluation. A total of 252 parasymphyseal fractures in 200 patients were selected for the study over the period of seven years (January 2010-January2017) and divided randomly into two groups. The first group included 126 fractures treated with two conventional titanium miniplates (conventional group) and the second 126 fractures treated with one customised, titanium, CRB, omega miniplate (customised group). All operations were done by the same surgeon. Duration of operation (from placement of incision to closure of the defect) was recorded. Postoperative paraesthesia, infection, and acceptability of the plate to patients were also recorded. Postoperative healing was evaluated radiologically at one week and six months postoperatively. Operations were significantly shorter, and significantly fewer patients developed paraesthesia or infection, in the customised group. These patients were also happier with their miniplates, and had good radiological bony healing. In conclusion, a single customised, titanium, CRB, omega miniplate is an effective and economical alternative to two conventional titanium miniplates in the management of parasymphysis fractures of the mandible.

Author Correction: Susceptible genes and disease mechanisms identified in frontotemporal dementia and frontotemporal dementia with Amyotrophic Lateral Sclerosis by DNA-methylation and GWAS

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.

Comparative evaluation of MCP gene in worldwide strains of Megalocytivirus (Iridoviridae family) for early diagnostic marker

Members of the Iridoviridae family have been considered as aetiological agents of iridovirus diseases, causing fish mortalities and economic losses all over the world. Virus identification based on candidate gene sequencing is faster, more accurate and more reliable than other traditional phenotype methodologies. Iridoviridae viruses are covered by a protein shell (capsid) encoded by the important candidate gene, major capsid protein (MCP). In this study, we investigated the potential of the MCP gene for use in the diagnosis and identification of infections caused Megalocytivirus of the Iridoviridae family. We selected data of 66 Iridoviridae family isolates (53 strains of Megalocytivirus, eight strains of iridoviruses and five strains of Ranavirus) infecting various species of fish distributed all over the world. A total of 53 strains of Megalocytivirus were used for designing the complete primer sets for identifying the most hypervariable region of the MCP gene. Further, our in silico analysis of 102 sequences of related and unrelated viruses reconfirms that primer sets could identify strains more specifically and offers a useful and fast alternative for routine clinical laboratory testing. Our findings suggest that phenotype observation along with diagnosis using universal primer sets can help detect infection or carriers at an early stage.

Recent advancements and new perspectives in animal models for Neurocysticercosis immunopathogenesis

Neurocysticercosis (NCC), one of the most common parasitic diseases of the central nervous system, is caused by Taenia solium. This parasite involves two hosts, intermediate hosts (pig and human) and a definitive host (human) and has various stages in its complex life cycle (eggs, oncosphere, cysticerci and adult tapeworm). Hence, developing an animal model for T. solium that mimics its natural course of infection is quite challenging. We have reviewed here the animal models frequently used to study immunopathogenesis of cysticercosis and also discussed their usefulness for NCC studies. We found that researchers have used mice, rats, guinea pigs, dogs, cats and pigs as models for this disease with varying degrees of success. Mice and rats models have been utilized extensively for immunopathogenesis studies due to their relative ease of handling and abundance of commercially available reagents to study these small animal models. These models have provided some very exciting results for in-depth understanding of the disease. Of late, the experimentally/naturally infected swine model is turning out to be the best animal model as the disease progression closely resembles human infection in pigs. However, handling large experimental animals has its own challenges and limitations.

Role of extracytoplasmic function sigma factor PG1660 (RpoE) in the oxidative stress resistance regulatory network of Porphyromonas gingivalis

In Porphyromonas gingivalis, the protein PG1660, composed of 174 amino acids, is annotated as an extracytoplasmic function (ECF) sigma factor (RpoE homologue-σ24). Because PG1660 can modulate several virulence factors and responds to environmental signals in P. gingivalis, its genetic properties were evaluated. PG1660 is co-transcribed with its downstream gene PG1659, and the transcription start site was identified as adenine residue 54-nucleotides upstream of the ATG translation start codon. In addition to binding its own promoter, using the purified rPG1660 and RNAP core enzyme from Escherichia coli with the PG1660 promoter DNA as template, the function of PG1660 as a sigma factor was demonstrated in an in vitro transcription assay. Transcriptome analyses of a P. gingivalis PG1660-defective isogenic mutant revealed that under oxidative stress conditions 176 genes including genes involved in secondary metabolism were downregulated more than two-fold compared with the parental strain. The rPG1660 protein also showed the ability to bind to the promoters of the highly downregulated genes in the PG1660-deficient mutant. As the ECF sigma factor PG0162 has a 29% identity with PG1660 and can modulate its expression, the cross-talk between their regulatory networks was explored. The expression profile of the PG0162PG1660-deficient mutant (P. gingivalis FLL356) revealed that the type IX secretion system genes and several virulence genes were downregulated under hydrogen peroxide stress conditions. Taken together, we have confirmed that PG1660 can function as a sigma factor, and plays an important regulatory role in the oxidative stress and virulence regulatory network of P. gingivalis.