A tetranuclear nickel(II) complex, [Ni4(L)4](ClO4)4·C2H3N·2H2O, with an asymmetric Ni4O4 open-cubane-like core

A tetra­nuclear complex with an open-cubane like structure was synthesized from 2-meth­oxy-6-(pyridin-2-yl-hydrazonometh­yl)-phenol and characterized using micro-analytical and spectroscopic techniques, and single-crystal X-ray diffraction analysis.

A tetra­nuclear complex with an open-cubane-like core structure was synthesized from 2-meth­oxy-6-(pyridin-2-yl-hydrazonometh­yl)phenol (HL), namely, cyclo-tetra­kis­(μ-2-meth­oxy-6-{[2-(pyridin-2-yl)hydrazin-1-yl­idene]meth­yl}pheno­lato)tetra­nickel(II) tetra­kis­(perchlorate) aceto­nitrile monosolvate dihydrate, [Ni₄(C₁₃H₁₂N₃O₂)₄](ClO₄)₄·C₂H₃N·2H₂O, and characterized using micro-analytical and spectroscopic techniques. The crystal-structure determination reveals the formation of a distorted Ni₄O₄ cubane-like core architecture encapsulated by four hydrazone Schiff base (HL) mol­ecules. A open-cube tetra­nuclear architecture is created in which nickel(II) ions of the NiN₂O₃ unit are connected by μ₂-O anions of the phenolate moiety of HL. In this complex, each Ni centre has a slightly distorted square-pyramidal coordination environment. The supra­molecular architectures are stabilized via the presence of various inter­molecular hydrogen bonds and (ar­yl–aryl, ar­yl–chelate and chelate–chelate) stacking inter­actions.

In vitro functional analysis of gRNA sites regulating assembly of hepatitis B virus

The roles of RNA sequence/structure motifs, Packaging Signals (PSs), for regulating assembly of an HBV genome transcript have been investigated in an efficient in vitro assay containing only core protein (Cp) and RNA. Variants of three conserved PSs, within the genome of a strain not used previously, preventing correct presentation of a Cp-recognition loop motif are differentially deleterious for assembly of nucleocapsid-like particles (NCPs). Cryo-electron microscopy reconstruction of the T = 4 NCPs formed with the wild-type gRNA transcript, reveal that the interior of the Cp shell is in contact with lower resolution density, potentially encompassing the arginine-rich protein domains and gRNA. Symmetry relaxation followed by asymmetric reconstruction reveal that such contacts are made at every symmetry axis. We infer from their regulation of assembly that some of these contacts would involve gRNA PSs, and confirmed this by X-ray RNA footprinting. Mutation of the ε stem-loop in the gRNA, where polymerase binds in vivo, produces a poor RNA assembly substrate with Cp alone, largely due to alterations in its conformation. The results show that RNA PSs regulate assembly of HBV genomic transcripts in vitro, and therefore may play similar roles in vivo, in concert with other molecular factors.

Development, evaluation and validation of machine learning algorithms to detect atypical and asymptomatic presentations of Covid-19 in hospital practice

BACKGROUND

Diagnostic methods for Covid-19 have improved, both in speed and availability. Because of atypical and asymptomatic carriage of the virus and nosocomial spread within institutions, timely diagnosis remains a challenge. Machine learning models trained on blood test results have shown promise in identifying cases of Covid-19.

AIMS

To train and validate a machine learning model capable of differentiating Covid-19 positive from negative patients using routine blood tests and assess the model's accuracy against atypical and asymptomatic presentations.

DESIGN AND METHODS

We conducted a retrospective analysis of medical admissions to our institution during March and April 2020. Participants were categorized into Covid-19 positive or negative groups based on clinical, radiological features or nasopharyngeal swab. A machine learning model was trained on laboratory parameters and validated for accuracy, sensitivity and specificity and externally validated at an unconnected establishment.

RESULTS

An Ensemble Bagged Tree model was trained on data collected from 405 patients (212 Covid-19 positive) producing an accuracy of 81.79% (95% confidence interval (CI) 77.53-85.55%), the sensitivity of 85.85% (CI 80.42-90.24%) and specificity of 76.65% (CI 69.49-82.84%). Accuracy was preserved for atypical and asymptomatic subgroups. Using an external data set for 226 patients (141 Covid-19 positive) accuracy of 76.82% (CI 70.87-82.08%), sensitivity of 78.38% (CI 70.87-84.72%) and specificity of 74.12% (CI 63.48-83.01%) was achieved.

CONCLUSION

A machine learning model using routine laboratory parameters can detect atypical and asymptomatic presentations of Covid-19 and might be an adjunct to existing screening measures.

Effect of thrombocytopenia in patients with infective endocarditis: an insight from the National Inpatient Sample database

Introduction

Infective endocarditis (IE) is one of the feared diseases in septic patients, and incidences are rising due to the intravenous drug abuse epidemic. Sepsis causes an escalation of the platelet destructions leading to thrombocytopenia (1). Few independent hospital-based studies have proposed increase mortality with thrombocytopenia in patients with IE (2–5). We aim to evaluate the significance of thrombocytopenia in IE subjects from the national inpatient sample (NIS) database.

Method

We analyzed the NIS database from Jan-2016 to Dec-2018 using Stata 16.0. NIS is the largest publicly available all-payer inpatient care database in the United States, containing data on more than seven million hospital stays per year. We identified patients with IE with or without thrombocytopenia using ICD-10 codes. The primary outcome of interest was in-hospital mortality comparison. We adjusted potential confounders (age, sex, diabetes, hypertension, etc.) with multivariate logistic regression analysis. Further analysis was done after balancing the population co-morbidity using a Greedy propensity match for accuracy.

Results

A total of 174,495 subjects were included in this study with a diagnosis of IE. Among these individuals, 33,285 patients had a concurrent diagnosis of thrombocytopenia. The mean ages were 53±19.5 years for the thrombocytopenia group and 55±19.8 years for others. Females were equally represented in both cohorts. There were 4,945 (14.86%) vs 2,835 (2.01%) mortalities reported in with and without thrombocytopenia group respectively. After propensity matching, there was a pronounced increase in mortality [Odds ratio (OR): 1.93 (1.72 – 2.15), p-value: <0.001] in the group with thrombocytopenia comparing to others. Complications such as Major bleeding requiring blood transfusion [OR: 1.45 (1.35–1.57)], acute myocardial infarction [OR: 1.56 (1.35–1.70)], complete heart block [OR: 1.44 (1.16–1.53)], cardiac arrest [OR: 1.44 (1.25–1.72)], acute respiratory failure [OR: 1.51 (1.39–1.73)] and pressor support requirement [(OR: 1.73 (1.57–2.01)] were notably higher in the cohort of thrombocytopenia with statistically significant p-value (<0.001). The difference in length of stay between both cohorts after propensity match wasn't statistically significant.

Conclusion

In conclusion, IE patients with thrombocytopenia have higher incidences of in-patient mortality and poor outcomes than cohort without thrombocytopenia. Some of the adverse consequences could be temporally explained by complications related to underlying thrombocytopenia. Further investigations are needed to delineate the outcome in this group of subjects.

Funding Acknowledgement

Type of funding sources: None.

Impact of atrial fibrillation in patients with colorectal cancer: a national inpatient sample database analysis

Background

Atrial fibrillation (AF) is the most common cardiac arrhythmia affecting approximately 1–2% overall population (1). Its causal relationship with colorectal cancer (CRC) is much for debate. According to one hypothesis, the presence of autoantibodies directed against ionic channels or acetylcholine receptors can predispose to the development of atrial fibrillation (2–3). Thus, AF may be regarded as an inflammatory complication in patients with colon cancer. Our study objective was to determine if AF impacts the outcome of patients with CRC.

Method

We analyzed the National Inpatient Sample (NIS) database from Oct-2015 to Dec 2018 using Stata 16.0. The NIS databases are released under the Healthcare Cost and Utilization Project, which includes inpatient admissions from the United States' participating hospitals. Total population with CRC were identified using their respective ICD-10 diagnostic codes then divided based on AF. To determine atrial fibrillation association with mortality and complications, we used multivariate logistic regression analysis using weights to generate nationally representative results. Later, a propensity-matched population analysis was done for the accuracy of the results.

Result

We found 245,305 patients admitted with CRC between Oct 2015 to Dec-2018 in the USA, out of which 28,170 (11.5%) were having AF. The mean age for the patients with AF was 77±10 compare to 65±14 years in those without AF. Patients with AF were associated with higher comorbidities and had a high population percentage with Carlson category three or above. There were 1,456 (5.2%) mortalities in the AF group compared to 5,689 (2.6%) in the other. The higher odds of mortality in patients with AF was present in multivariate logistic regression analysis in both non-propensity matched [1.71 (1.45–2.02), P-value: <0.000] and propensity-matched [1.44 (1.18–1.75), P-value: <0.001] cohorts. Patients with AF were hospitalized longer (9.20±7.8 vs. 6.85±7.0 days), leading to a high admission costs (US$ 25,875±22,875 vs. 20,087±19,314). Odds of complications such as need for blood transfusions [1.61 (1.05–1.29), P-value: 0.005], hemorrhage requiring blood transfusion [1.17 (1.05–1.29), P-value: 0.003], lower-GI bleed [1.31 (1.21–1.43), P-value: <0.001], sepsis [1.45 (1.30–1.62), P-value: <0.001], respiratory failure [1.39 (1.15–1.67), P-value: 0.001] etc. were also higher in group of patients with CRC and AF.

Conclusion

In our retrospective, propensity-matched national inpatient sample analyses of patients admitted with colorectal cancer, atrial fibrillation is associated with higher morbidity and mortality. AF was associated with a high burden of complications with prolonged hospital stay leading to increased health care expenditures.

Funding Acknowledgement

Type of funding sources: None.

The role of premorbid transthoracic echocardiogram in identifying adverse clinical outcomes in patients admitted with COVID-19

Background/Introduction

The novel coronavirus disease (COVID-19) inpatient mortality rate is approximately 20% in the United States. Reports have described a wide pattern of abnormalities in echocardiograms performed in patients admitted with COVID-19. The role of premorbid transthoracic echocardiogram (TTE) in the prediction of COVID-19 severity and mortality is yet to be fully assessed.

Purpose

To assess whether a pre-COVID TTE can identify patients at high risk of adverse outcomes who are admitted with COVID-19.

Methods

All patients who underwent a TTE from one year to one month prior to an index inpatient admission for COVID-19 were retrospectively enrolled across five clinical sites. Demographic information, medical history, and laboratory data were included for analysis. Echocardiograms were analyzed by an observer blinded to clinical data. Linear and logistic regressions were performed to detect the association of variables with death, invasive mechanical ventilation, initiation of dialysis, and a composite of these endpoints during the COVID-19 admission. Outcomes were then adjusted for a risk score using inverse propensity weighting incorporating age, sex, diabetes, hypertension, obstructive sleep apnea, history of atherosclerotic cardiovascular disease, atrial fibrillation, diuretic use, and angiotensin-converting enzyme inhibitor or angiotensin receptor blocker use.

Results

There were 104 patients (68±15 years old, 49% male, BMI 31.4±9.1kg/m2) who met inclusion criteria (baseline characteristics in Table 1). Mean time from TTE to positive SARS-CoV-2 PCR test was 139±91 days. Twenty-nine (28%) participants died during the index COVID-19 admission. There was no association of pre-COVID echocardiographic measures of systolic ventricular function with any endpoint. Diastolic function, as assessed by LV e', was associated with mortality (Table 2). There were 25 patients (24%) with a normal lateral e' (≥10cm/s); none died. There were 35 (34%) patients with LV e' lateral velocity <8 cm/s, of whom 15 (43%) died. LV e' lateral velocity <8 cm/s was associated with an unadjusted odds ratio of 7.69 (95% confidence interval [CI] 2.26–26.19) for death and 3.25 (95% CI 1.11–9.54) for the composite outcome. The odds ratio for death was 4.76 (95% CI 1.10–20.61) and 3.78 (95% CI 0.98–14.6) for the composite outcome after adjustment for clinical risk factors (Table 2).

Conclusion

In patients with an echocardiogram prior to COVID-19, impaired diastolic function as represented by an abnormal LV e' lateral velocity was associated with both inpatient COVID-19 mortality and a composite outcome of death, mechanical ventilation, and initiation of dialysis, even after adjustment for multiple co-morbidities and medication use. Knowledge of the pre-COVID TTE results may help clinicians identify patients at higher risk of adverse outcomes during an admission for COVID-19.

Funding Acknowledgement

Type of funding sources: None.

Racial disparities in the use of mechanical circulatory support devices in cardiogenic shock

Background

Racial bias has always been a concern for healthcare. Lack of guideline directed utilization of mechanical circulatory support (MCS) devices in cardiogenic shock (CS) may lead to implicit and racial bias.

Purpose

To identify the racial differences in the use of mechanical circulatory support in cardiogenic shock and its association with outcomes.

Methods

National Inpatient Database from 2015–2018 using ICD 10 codes was used. Patients >18 years of age admitted for cariogenic shock were included.

Results

Among 1,021,274 patients hospitalized for cardiogenic shock, overall MCS was utilized in 11.4% (N=116,539). Use of MCS for patients stratified by race was 12.2% white (N=85543), 8% Blacks (N=14688), 11.3% Hispanics (N=11067), 13.8% Asian (N=4417), 12.3% Native American (N=825). IABP was the most commonly used MCS device, followed by Impella, ECMO and LVAD. Overall odds of MCS insertion was significantly higher in white population [1.18 (1.13–1.23) <0.001] and significantly lower in Blacks [0.65 (0.61–0.69) <0.001] and Hispanics [0.89 (0.83–0.97) 0.004]. Among black patients with CS requiring MCS, odds of LVAD insertion were similar compared to other races [1.03 (0.89–1.19) 0.714], while odds of all other types of MCS devices including ECMO [0.83 (0.72–0.95) 0.009], IABP [0.63 (0.59–0.68) <0.001] and Impella [0.61 (0.54–0.70) <0.001] were significantly lower compared to other races. This trend also holds true for patients with CS associated with acute myocardial infarction. Among all patients with CS, the odds of mortality were significantly lower among white patients [0.92 (0.90–0.95) <0.001], on the contrary, odds of mortality were significantly higher in Blacks [1.06 (1.02–1.10) 0.001] and Asians [1.11 (1.02–1.20) 0.012]. Interestingly, when only comparing patients who underwent MCS utilization for CS, odds of mortality were similar in black population compared to other races. [1.03 (0.91–1.17) 0.636].

Conclusion(s)

There still exist significant racial differences in the use of mechanical circulatory devices for cardiogenic shock potentially leading to significantly higher mortality in black population compared to whites. This difference in mortality is mitigated with equal use of MCS devices in cardiogenic shock among all races.

Funding Acknowledgement

Type of funding sources: None.

Cryoablation versus anti-arrhythmic therapy for initial treatment of atrial fibrillation: a systematic review and meta-analysis

Introduction

Atrial fibrillation is a common cardiac arrhythmia that affects approximately 2% of the overall population. Guidelines suggest the use of anti-arrhythmic agents as initial therapy in patients with symptomatic atrial fibrillation, however using cryoablation as a first line therapy might have increased efficacy. The safety and efficacy of cryoablation as initial therapy has not yet been established.

Purpose

We performed a systematic review and meta-analysis of randomized controlled trials to investigate the use of cryoballoon catheter ablation compared to anti-arrhythmic therapy as an initial intervention to prevent recurrence of atrial tachyarrhythmias in patients with atrial fibrillation. We also wanted to determine if using this initial ablative approach did not present increased adverse events.

Methods

A comprehensive search of multiple databases was performed to find randomized control trials that directly compared cryoablation therapy versus anti-arrhythmic therapy as initial treatment for patients with atrial fibrillation. A total of three RCTs met the inclusion criteria (724 patients) and were used in the meta-analysis. The primary outcome of our meta-analysis was recurrence of atrial tachyarrhythmias. The secondary outcome evaluated serious adverse events of each therapy.

Results

The results showed a statistically significant reduction of recurrence of atrial tachyarrhythmic events in patients receiving cryoablation compared to anti-arrhythmic therapy [Risk Ratio (RR): 0.60, 95% CI (0.49, 0.72), P<0.ehab724.03521, I2=0%]. There was no significant difference in serious adverse events between patients receiving cryoablation compared to patients receiving anti-arrhythmic therapy. [Risk Ratio (RR): 1.19, 95% CI (0.71, 2.00), P=0.52, I2=0%].

Conclusion

Our meta-analysis showed that cryoablation therapy as an initial therapy is more efficacious than anti-arrhythmic therapy in patients with atrial fibrillation without an increased risk of serious adverse events.

Funding Acknowledgement

Type of funding sources: None.

Gender based outcome of IABP implantation in patients with acute coronary syndrome and cardiogenic shock: a national inpatient sample database analysis

Background

Intra-Aortic Balloon counter-pulsation is frequently used as a circulatory support device in patients requiring hemodynamic support - in cardiogenic shock and in patients at risk of hemodynamic decompensation during a high-risk coronary intervention. Impact of IABP in this patient population has been variable. Certain studies have shown a beneficial effect of IABP on selected populations having acute coronary syndrome with cardiogenic shock (1–3). Our objective was to compare the outcomes based on gender in the ACS population with cardiogenic shock and IABP placement.

Methods

We analyzed the National Inpatient Sample database from Oct-2015 to Dec-2017 released under Healthcare Cost utilization Project in the USA using Stata 16.0. The population was identified using respective ICD-10 codes. We excluded the population with sudden cardiac arrest, pulmonary embolism, and patients with anatomical post-MI complications. Multivariate logistic regression analysis was done to determine the difference in outcomes based on gender using clinically relevant variables. Later, propensity-matched cohort analysis was performed based on the regression variables.

Results

Of 36, 990 patients who met our inclusion criteria 25,670 (69%) were male and 11,320 (31%) were female. The average age for male and female populations was 66±11 and 69±12 years. Femnales were more likely to have higher Charlson co-morbidity index three or above. We found higher mortality in the female population [3,146 (27.79%)] compared to male [5,884 (22.92%)] in univariate analyses. Propensity-matched multivariate regression analysis showed no difference [OR: 1.06 (0.91–1.22) with P-value: 0.482] in mortality after adjusting for clinically relevant variables. Subgroup analysis in STEMI and NSTEMI populations did not show a difference. The average hospital stay was similar in both cohorts, with the male having a higher cost per stay. We found no difference in most of the complications included in our study except for higher coronary artery dissection [OR: 2.98 (1.73–5.13), P-value: <0.001] and lower rates of AKI [OR: 0.72 (0.63–0.83), P-value: <0.001], AKI requiring hemodialysis [OR: 0.74 (0.56–0.97), P-value:0.031] and ventricular tachycardia [OR: 0.73 (0.64–0.84), P-value: <0.001] in the female population.

Conclusion

The inpatient population of ACS with Cardiogenic shock and IABP insertion showed no significant difference in mortality between males and females which was valid for subgroup analysis of NSTEMI and STEMI groups. Complications such as coronary artery dissection were higher, whereas AKI, AKI requiring hemodialysis, and ventricular tachycardias, were lower in females than males.

Funding Acknowledgement

Type of funding sources: None.

Comparing loading strategies of P2Y12 inhibitors in patients undergoing elective PCI: a network meta-analysis

Introduction

Effective platelet inhibition prior to elective percutaneous coronary intervention (PCI) reduces the risk of ischemic complications. Newer P2Y12 inhibitors are preferred agents over clopidogrel for patients presenting with acute coronary syndrome. However, the comparative efficacy and safety of them over clopidogrel in elective PCI is unclear. Our objective was to perform a network meta-analysis and assess that from randomized controlled trials (RCT).

Methods

We conducted a systematic review of RCTs up to and including November 2020. The endpoints of interest were overall mortality, rates of myocardial infarction (MI), stroke, revascularization and major bleeding. Random effects model using frequentist approach was used to perform a network meta-analysis using R software.

Results

5 trials with total of 5,194 patients were included in our analysis. For ischemic outcomes including MI, Stroke and revascularization, prasugrel had the most favorable trend. However, clopidogrel had the highest probability of being most effective for major bleeding and all-cause mortality. None of these trends were statistically significant due to lack of power for each individual outcome (Figure 1).

Conclusion

Prasugrel and ticagrelor seem to show better efficacy in preventing MI and stroke. However, their effects are marginal and do not translate into improved overall mortality and bleeding. Therefore, in this lower risk population presenting for elective PCI, clopidogrel remains a reasonable P2Y12 inhibitor choice in lower risk population.

Funding Acknowledgement

Type of funding sources: None. Results

Sex-based differences in clinical outcomes and resource utilization of type 2 myocardial infarction

Background

Sex-based differences in clinical outcomes have been previously well described in type 1 myocardial infarction (MI). However, type 2 MI is common in contemporary practice with scarce data regarding sex-based differences of clinical outcomes and resource utilization.

Purpose

To examine the association of sex category with clinical outcomes and resource utilization in hospitalizations with type 2 MI.

Methods

The Nationwide Readmission Database 2018 was queried for hospitalizations within the United States with type 2 MI using The International Classification of Diseases, Tenth Revision (ICD-10) diagnosis code I21.A1. Comorbidities and outcomes were identified using the corresponding ICD-10 codes. Complex samples multivariable logistic and linear regression models were used to determine the association between type 2 MI and outcomes (in-hospital mortality, index length of stay [LOS], hospital costs, discharge to nursing facility, and 30-day all-cause readmissions) in females compared to males with type 2 MI.

Results

A total of 252,641 hospitalizations [119,783 (47.4%) females and 132,858 (52.6%) males] were included in this analysis. Females with type 2 MI were more likely to be older (72.8 years vs. 69.7 years; P<0.001), admitted on the weekend (26.5% vs. 25.9%; P=0.02), and have a higher prevalence of chronic pulmonary disease (35.6% vs. 32.0%; P<0.001), obesity (17.9% vs. 15.7%; P<0.001), neurological disorders (22.9% vs. 22.3%; P=0.02), deficiency anemias (7.5% vs. 6.6%; P<0.001), and hypothyroidism (22.1% vs. 10.1%; P<0.001) compared to males with type 2 MI. Female with type 2 MI was associated with lower in-hospital mortality, shorter LOS, less hospital costs, and increased nursing home discharge compared to males with type 2 MI. Females and males with type 2 MI had similar rates of 30-day all-cause readmission [Table 1].

Conclusion

Among type 2 MI hospitalizations, females have lower in-hospital mortality, less hospitalization cost, shorter LOS, but increased rates of nursing home discharge compared to males. Thirty-day all-cause readmission was similar between males and females with type 2 MI.

Funding Acknowledgement

Type of funding sources: None.

280 The Use of Telemedicine in Plastics Surgery During COVID-19: A Single-Centre Correlation Study with Patient Reported Outcome Measures

Aim

With enforcement of social distancing measures during the COVID-19 pandemic, face-to-face patient contact was shifted to telemedicine consultations. There is limited evidence evaluating patient experience of follow-ups and expectations into quality metrics. Our aim was to perform a service evaluation by prospectively evaluating the management and outcomes of plastic surgery patients.

Method

Patients were consecutively assessed over the COVID-19 lockdown period, from March to May 2020. They ranged from urgent cancer cases to burns and trauma. We used a questionnaire to evaluate initial treatment, wound care, complications, and overall service. A validated health-related quality of life (HRQL) survey was used to assess the impact of injury or wound on lifestyle and we also assessed patient enablement. Correlation analysis determined relationships between outcomes, service evaluations and HRQL variables.

Results

77 patients were consecutively treated in our unit, of which 46 completed the questionnaire. 42.2% used multimedia as mode of follow-up, including smart phones for messages and videocalls, and trust e-mails. There was a 3-fold increase in number of infections for non-face-to-face consultations, with a correlation significance of 0.043. We found no correlation between age and wound complication rates. 72.7% of patients found overall service very good or excellent. Although overall service satisfaction was similar for multimedia use and face-to-face consultations (p = 0.02), less patients were confident looking after their wound without face-to-face follow-ups.

Conclusions

COVID-19 has brought upon an unprecedented change in practice in our department. Implementing multimedia use and educating patients on wound care can significantly improve efficiency and service provision.

1168 Radiotherapy Dose for HPV Driven Oropharyngeal Cancer: What Is Enough?

Aim

Squamous cell carcinoma of the oropharynx is associated with high-risk Human Papilloma Virus (HPV) infection. HPV positive oropharyngeal cancer is often more radiosensitive and first line treatment includes either radiotherapy or surgical resection. Trials are ongoing to establish situations in which radiation doses can be reduced with the aim of reducing late tissue toxicity (“de-escalation trials”) . We report a case in which a patient failed to complete his prescribed radiotherapy treatment, describe his clinical outcomes and the potential questions this situation raises.

Method

In 2009 a male patient presented with a right T2N0MO P16 positive tonsillar squamous cell carcinoma. He was scheduled to complete a course of chemoradiotherapy. However, he was only able to complete a third of the radiotherapy course. Due to unresolved symptoms, he underwent a right transoral laser extended tonsillectomy, however this showed only fibrous tissue.

Results

Despite not completing the radiotherapy course he has not experienced local recurrence of the tonsillar OPSCC 11 years post initial treatment.

Conclusions

This case illustrates that some patients with HPV driven oropharyngeal cancer can have a clinically significant tumour response to markedly lower doses of radiotherapy than is currently recommended. Further randomized controlled trials are required to establish the optimum dose in the management of HPV driven oropharyngeal squamous cell cancer.

Phase I/II trial of palbociclib, pembrolizumab and letrozole in patients with hormone receptor-positive metastatic breast cancer

BACKGROUND

CDK4/6 inhibitors modulate immune response in breast cancer. This phase I/II trial was designed to test the safety and efficacy of palbociclib, pembrolizumab and letrozole in women with hormone receptor positive (HR⁺) human epidermal growth factor receptor 2 negative (HER2^-) metastatic breast cancer (MBC).

PATIENTS AND METHODS

Women with stage IV HR⁺ HER2^- MBC were enrolled and treated with palbociclib, pembrolizumab and letrozole. Primary end-points were safety, tolerability and efficacy.

RESULTS

Between November 2016 and July 2020, 23 patients were enrolled with 20 evaluable for response, including 4 patients in cohort 1 and 16 patients in cohort 2. Cohort 1 median age was 48 years (33-70) and cohort 2 median age was 55 (37-75). Cohort 1 closed early due to limited accrual. Grade III-IV adverse events were neutropenia (83%), leucopaenia (65%), thrombocytopenia (17%) and elevated liver enzymes (17%). In cohort 1, 50% achieved a partial response (PR) and 50% had stable disease (SD). In cohort 2, 31% achieved complete response (CR), 25% had PR and 31% had SD by Response Evaluation Criteria in Solid Tumours version 1.1. Median progression-free survival was 25.2 months (95% confidence interval [CI] 5.3, not reached) and median overall survival was 36.9 months (95% CI 36.9, not reached) in cohort 2 with a median follow-up of 24.8 months (95% CI 17.1, not reached). A correlative immune biomarker analysis was published separately.

CONCLUSION

The combination of palbociclib, pembrolizumab and letrozole is well tolerated, and a complete response rate of 31% was identified in HR⁺ MBC patients who received this combination as front-line therapy. Confirmatory trials are required to better understand the immune-priming effects of CDK4/6 inhibitors.

Neonatal surgical outcomes: a prospective observational study at a Tertiary Academic Hospital in Johannesburg, South Africa

PURPOSE

The neonatal period is the most vulnerable period for a child. There is a paucity of data on the burden of neonatal surgical disease in our setting. The aim of this study was to describe the frequency with which index neonatal surgical conditions are seen within our setting and to document the 30-day outcome of these patients.

METHODS

This was a single-centre prospective observational study in which all neonates with paediatric surgical pathology referred to the paediatric surgical unit with a corrected gestational age of 28 days were included.

RESULTS

Necrotising enterocolitis was the most frequent reason for referral to the paediatric surgical unit (n = 68, 34.34%). Gastroschisis was the most frequent congenital anomaly referred (n = 20, 10.10%). The overall morbidity was 57.58%. Surgical complications contributed to 18.51% of morbidities. The development of gram negative nosocomial sepsis was the most frequent cause of morbidity (n = 98, 50.78%). Mortality at 30 days was 21.74% (n = 40). Sepsis contributed to mortality in 35 patients (87.5%), 16 of which had gram negative sepsis.

CONCLUSION

Gram-negative sepsis was a major contributing factor in the development of morbidity and mortality in our cohort. Prevention and improvement in infection control are imperative if we are to improve outcomes in our surgical neonates.

Evolution of a virus-like architecture and packaging mechanism in a repurposed bacterial protein

Viruses are ubiquitous pathogens of global impact. Prompted by the hypothesis that their earliest progenitors recruited host proteins for virion formation, we have used stringent laboratory evolution to convert a bacterial enzyme that lacks affinity for nucleic acids into an artificial nucleocapsid that efficiently packages and protects multiple copies of its own encoding messenger RNA. Revealing remarkable convergence on the molecular hallmarks of natural viruses, the accompanying changes reorganized the protein building blocks into an interlaced 240-subunit icosahedral capsid that is impermeable to nucleases, and emergence of a robust RNA stem-loop packaging cassette ensured high encapsidation yields and specificity. In addition to evincing a plausible evolutionary pathway for primordial viruses, these findings highlight practical strategies for developing nonviral carriers for diverse vaccine and delivery applications.

Dupilumab reduces systemic corticosteroid use and sinonasal surgery rate in CRSwNP

BACKGROUND

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a type 2 inflammatory disease with a high symptom burden and poor quality of life. Treatment options include recurrent surgeries and/or frequent systemic corticosteroids (SCS). Dupilumab, a fully human monoclonal antibody, blocks the shared receptor component for interleukin-4 and interleukin-13, key drivers of type 2-mediated inflammation. We report results of pooled analyses from 2 randomised, double-blind, placebo-controlled phase 3 studies (SINUS 24 [NCT02912468]; SINUS-52 [NCT02898454]) to evaluate dupilumab effect versus placebo in adults with CRSwNP with/without SCS use and sinonasal surgery.

METHODOLOGY

SINUS-24 patients were randomised 1:1 to subcutaneous dupilumab 300 mg (n=143) or placebo (n=133) every 2 weeks (q2w) for 24 weeks. SINUS-52 patients were randomised 1:1:1 to 52 weeks of subcutaneous dupilumab 300 mg q2w (n=150), 24 weeks q2w followed by 28 weeks of dupilumab 300 mg every 4 weeks (n=145) or 52 weeks of placebo q2w (n=153).

RESULTS

Dupilumab reduced the number of patients undergoing sinonasal surgery (82.6%), the need for in-study SCS use (73.9%), and SCS courses (75.3%). Significant improvements were observed with dupilumab vs placebo regardless of prior sinonasal surgery or SCS use in nasal polyp, nasal congestion, Lund-MacKay, and Sinonasal Outcome Test (22-items) scores, and the University of Pennsylvania Smell Identification Test.

CONCLUSIONS

Dupilumab demonstrated significant improvements in disease signs and symptoms and reduced the need for sino-nasal surgery and SCS use versus placebo in patients with severe CRSwNP, regardless of SCS use in the previous 2 years, or prior sinonasal surgery.