Local electronic structure of histidine in aqueous solution

X-Ray spectroscopy coupled with DFT calculations reveals the pH dependent electronic structure of an amino acid in an aqueous environment.

Properties of ^{187}Ta Revealed through Isomeric Decay

Mass-separated ^{187}Ta_{114} in a high-spin isomeric state has been produced for the first time by multinucleon transfer reactions, employing an argon gas-stopping cell and laser ionization. Internal γ rays revealed a T_{1/2}=7.3±0.9  s isomer at 1778±1  keV, which decays through a rotational band with perturbations associated with the approach to a prolate-oblate shape transition. Model calculations show less influence from triaxiality compared to heavier elements in the same mass region. The isomer-decay reduced E2 hindrance factor f_{ν}=27±1 supports the interpretation that axial symmetry is approximately conserved.

Navigating the Diagnostics of COVID-19

Introduction/Objective

The recent outbreak of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) began in Hubei province, China in December 2019 and has spread worldwide at an alarming rate. With millions of individuals infected and over two hundred thousand deaths, the necessity to develop fast and efficient diagnostic methods is of high importance. Diagnostic modalities rely on a combination of epidemiology, clinical presentation, laboratory examination, and appropriate imaging to diagnose and distinguish SARS-CoV-2 from other pulmonary infections. The purpose of this paper is to report on currently available diagnostic screening methods for patients infected with SARS-CoV-2 to guide frontline healthcare workers involved with COVID-19 patient care.

Methods

An electronic literature search was performed for peer-reviewed articles published from January 1, 2020, until April 26, 2020. Articles were then reviewed and included based on the applicability to the topic.

Results

The preferred diagnostic approach is reverse transcription of the virus’ RNA followed by PCR amplification (RT-PCR). This method recognizes the gene-specific primers to target various viral protein genes, such as the envelope protein gene or the nucleocapsid protein gene, which enables this test to be both sensitive and specific toward SARS-CoV-2. However, this method has been proven to be time-consuming taking hours-to-days for the results. In order to improve the speed and efficiency of diagnostics, newer rapid diagnostic serological tests are being developed for testing SARS-CoV-2, each with its own unique advantages and disadvantages. They could potentially be used as triage tests to rapidly identify patients who are very likely to have COVID-19 in combination with other accurate diagnostic methods.

Conclusion

Therefore, a combination of diagnostic testing used in a timely manner may be beneficial for the rapid and accurate detection of SARS-CoV-2. This was evident in cases where despite initial negative RT-PCR tests for various patients, who later demonstrate chest CT scans with various degrees of consolidation and ground-glass opacity. Thus establishing the need for radiology diagnosis to be complementary to RT-PCR for COVID-19 patients. Hopefully, the continuous development and use of rapid diagnostic tests and the implementation of public health measures will help control the spread of the disease.

Prognosis of non-operative management of non-metastatic colorectal cancer in octa- and nonagenarians

INTRODUCTION

The aim of the study was to establish the natural history of elderly patients with non-metastatic colorectal cancer who underwent non-operative management in comparison with those who underwent operative management.

MATERIALS AND METHODS

A retrospective analysis of patients aged 80 years and above diagnosed with colorectal cancer between 2007 and 2015 in a tertiary care hospital in the Southwest of England was done. Patients were divided into non-operatively managed and operatively managed groups. Clinical demographics, Charlson Comorbidity Index, location of the tumour and overall survival between the two groups were compared.

RESULTS

A total of 407 patients were studied; 132 were treated non-operatively and 275 operatively. The non-operative group included fewer right-sided colon cancers (28.7% vs 54.9%), but significantly more rectal cancers were managed non-operatively (43.9 vs 23.6%, respectively). The two and five year overall survival was 38.9% and 11.3% respectively in the non-operative group, significantly lower than patients in the operative group where the two and five year survival was 78.9% and 59.6% respectively (p = .0001). The median Charlson Comorbidity Index was 7.99 for the non-operative group and 7.49 in the operative group (p = 0.109). Patients treated non-operatively were deemed unfit without objective frailty assessment and only 43/132(32.6%) had formal anaesthetic assessment before being deemed unfit for surgery.

CONCLUSION

The survival of octa- and nonagenarians with non-metastatic colorectal cancer managed conservatively is significantly less than counterparts managed operatively. Our present strategy of deciding and denying treatment of the elderly patient with colorectal cancer is arbitrary, highlighting the need for robust geriatric and frailty assessment.

The Role of Endobronchial Ultrasound in Early-Stage Non-Small Cell Lung Cancer

Aim The aim of this study is to assess the impact of EBUS on the concordance of clinical and pathological NSCLC staging in our center. Methods Data was collected retrospectively from the hospital database regarding patients who underwent surgical resection for early stage NSCLC between 2012 and 2017. Results A total of 251 patients were included. The mean age was 67 (±9), 55% (n=137) were male and 83% (n=209) were current/former smokers. In group A (n=154, 61%) clinical nodal stage (cN) was established from a combination of CT, PET CT and mediastinoscopy. Group B underwent additional EBUS (n=97, 39%). cN and pathological nodal staging (pN) were concordant in 78% (n=120) in group A versus 62% (n=60) in group B (p=0.009). Conclusion This study demonstrated higher rates of nodal discordance in patients who underwent EBUS which contrasts existing data that demonstrates improved concordance with EBUS. We describe these findings and potential explanations further in this study.

A Comparative Study Between 20% Mannitol and 3% Hypertonic Saline for Brain Oedema Reduction during Elective Brain Tumour Surgery

Cerebral oedema is an important manifestation of brain tumour. The significant reduction of cerebral oedema can show rapid improvement of the patients. Hypertonic saline solution and mannitol both are commonly used for this action. It is now time to choose the better one. This was a prospective randomized comparative study designed to evaluate the efficacy of 3% hypertonic saline (NaCl) in reduction of brain oedema during brain tumour surgery and compare it with that of 20% Mannitol. The study was conducted in the department of Anaesthesiology, Combined Military Hospital, Dhaka, Bangladesh from July 2016 to December 2016. A total number of 47 patients for brain tumour surgery were selected. After screening 40 patients were finalized. Then the patients were divided into 2 equal groups 20 patients in each. Patients of Group A received 3% hypertonic saline and Group B 20% mannitol. Uniform anaesthetic technique applied for all patients, fixed surgeon/group of surgeons carried out the surgery. Heart rate and noninvasive blood pressure were monitored and kept with in ±20% baseline values different means. ETCO2 were kept in between 28-32mm of Hg by adjusting ventilator setting. Reduction of brain oedema was monitored by subjective assessment of surgeons using a 3 point scale of brain relaxation. The data were recorded in preformed data sheet. The results were tested by chi-square test to see their level of significance i.e. p value <0.05 was considered as significant. At the opening of dura, the number of brain conditions classified as soft, adequate and tight were statistically non-significant between groups. After 0.5 hour and 1.0 hour 10% patient's brain was tight in Group A whereas it was 35% and 40% in Group B respectively. Reduction of brain oedema or brain relaxation was significantly better in Group A compared to Group B (p<0.05). Urine output was higher with mannitol than hypertonic saline (p<0.05). Duration of ICU and hospital stay in both Group A and Group B were statistically similar (p>0.05). Compared to mannitol, hypertonic saline caused an increase in serum sodium concentration over time (p<0.05). From the available data, use of 20% mannitol and 3% hypertonic saline for brain oedema reduction, it is suggested that hypertonic saline significantly reduces the risk of tight brain and produce the brain more soft than mannitol during brain tumour surgery.

Beyond the speed of SOUND

Much anticipation awaits the results of the SOUND trial, (Gentilini and Veronesi in Breast 21:678-681, 2012) which may prove the futility of performing sentinel node biopsy (SNB) in low-risk breast cancer patients. However, do we really not know the answer to the questions that the SOUND trial poses already? Consideration must be taken of the very much overlooked trials predating the sentinel node era, which risk stratified patients according to the absence of palpable lymphadenopathy and without dependence upon ultrasound imaging (clinically negative axilla). This automatically selects a low-risk group of patients for axillary disease (low axillary burden) and the relevance of these critical trials is discussed.

Computer-guided contouring of craniofacial fibrous dysplasia involving the zygoma using a patient-specific surgical depth guide

The aim of this study was to introduce a new computer-guided technique for contouring and shaving of craniofacial fibrous dysplasia involving the zygoma. Computer-guided contouring was performed for five patients with unilateral craniofacial fibrous dysplasia involving the zygoma, using a patient-specific surgical depth guide. This patient-specific guide with depth holes was virtually designed for each patient based on mirroring of the unaffected side. The guide was printed using rapid prototyping. In the surgical theatre, the guide was seated in place and implant drills were inserted through the guide holes, creating depth holes according to the preoperative planning. Bone removal was then continued using surgical burs and/or bone chisels, connecting the guiding depth holes. Satisfaction with facial aesthetics was evaluated by the patients using a Likert scale, and by the surgeons using the Whitaker rating scale. All patients were satisfied with the postoperative facial aesthetics. Four patients were rated category I on the Whitaker rating scale, and one patient as category II. In conclusion, this patient-specific surgical depth guide appears to offer a solution for the unpredictability of conventional bone removal in unilateral craniofacial fibrous dysplasia, especially in three-dimensional multiplanar areas such as the zygoma. Further investigations are required.

Multimodiale Therapie von Hirnmetastasen

Das Langzeitüberleben hat sich für Patienten mit metastasiertem Melanom durch die Etablierung der zielgerichteten Therapien sowie Immuntherapien mit 5-Jahres-Überlebensraten von ca. 50 % deutlich verbessert. Hirnmetastasen stellen jedoch weiterhin eine therapeutische Herausforderung dar. In der Vergangenheit lag das mediane Überleben für Patienten mit neu diagnostizierten Hirnmetastasen bei 2 – 6 Monaten 1. Retrospektive Analysen sprechen für einen Überlebensbenefit unter multimodaler Therapie mit einer 5-Jahres-Überlebensrate von über 20 % 1.

Wir berichten über einen 50-jährigen Patienten mit multiplen symptomatischen Hirnmetastasen bei Erstdiagnose. Nach Exstirpation einer symptomatischen Metastase wurde bei BRAF-V600E-Mutation eine Systemtherapie mit dem BRAF-Inhibitor Dabrafenib in Kombination mit dem MEK-Inhibitor Trametinib eingeleitet. Hierunter zeigte sich ein rascher deutlicher Regress der zerebralen und extrazerebralen Metastasen. Nach 8 Wochen wurde die Systemtherapie auf eine Immuntherapie mit Nivolumab plus Ipilimumab umgesetzt. Kurz nach Therapieeinleitung trat ein epileptischer Anfall auf und die Hirnmetastasen zeigten sich wieder progredient. Zwei symptomatische Hirnmetastasen wurden reseziert, eine Ganzhirnradiatio mit Hippocampusschonung wurde eingeleitet und die Immuntherapie fortgesetzt. Aktuell erfolgt eine zielgerichtete Therapie mit Encorafenib und Binimetinib. 17 Monate nach Erstdiagnose befindet sich der Patient in gutem Allgemeinzustand ohne neurologische Defizite. Dieser Fallbericht bestätigt den retrospektiv beobachteten Überlebensbenefit für Patienten mit Hirnmetastasen unter multimodaler Therapie.

National Clinical Guidance for the Management of Cardiovascular Intervention in the COVID-19 Pandemic: From Bangladesh Society of Cardiovascular Interventions (BSCI)

Since the first recorded case of SARS-CoV-2 in Bangladesh on 8th March 2020, COVID-19 has spread widely through different regions of the country, resulting in a necessity to re-evaluate the delivery of cardiovascular services, particularly procedures pertaining to interventional cardiology in resource-limited settings. Given its robust capacity for human-to-human transmission and potential of being a nosocomial source of infection, the disease has specific implications on healthcare systems and health care professionals faced with performing essential cardiac procedures in patients with a suspected or confirmed diagnosis of COVID-19. The limited resources in terms of cardiac catheterization laboratories that can be designated to treat only COVID positive patients are further compounded by the additional challenges of unavailability of widespread rapid testing on-site at tertiary cardiac hospitals in Bangladesh. This document prepared for our nation by the Bangladesh Society of Cardiovascular Interventions (BSCI) is intended to serve as a clinical practice guideline for cardiovascular health care professionals, with a focus on modifying standard practice of care during the COVID-19 pandemic, in order to ensure continuation of adequate and timely treatment of cardiovascular emergencies avoiding hospital-based transmission of SARS-COV-2 among healthcare professionals and the patients. This is an evolving document based on currently available global data and is tailored to healthcare systems in Bangladesh with particular focus on, but not limited to, invasive cardiology facilities (cardiac catheterization, electrophysiology & pacing labs). This guideline is limited to the provision of cardiovascular care, and it is expected that specific targeted pharmaco-therapeutics against SARS-CoV-2 be prescribed as stipulated by the National Guidelines on Clinical Management of Corona virus Disease 2019 (COVID-19) published by the Director General of Health Services, Ministry of Health and Family Welfare of Bangladesh.

P806 Cavitation phenomenon in mechanical valves: not only microbubbles

Introduction

It is well described the presence of microbubbles (MBs) which are high-velocity, small, bright echoes presences that occur with the closing/opening of the mechanical double disk valve, more frequently in mitral position but less frequent growth of the cavitation bubbles are described.

We considered the echo studies of patients with growth of cavitation bubbles and we evaluate the possible impact of the hemodynamic parameters of their formation and then misdiagnosis with endocarditis.

Methods

We analyzed retrospectively the echocardiographic studies of 49 patients with growth of cavitation bubbles and we went back to all studies until the date of surgery if available, to see in how many of those echos, this phenomenon was present.

Patient"s blood pressure (BP) and heart rate (HR) measurement were available for each echo study. For the present analysis the last echo study with or without growth of cavitation bubbles were considered. The last echo study without growth of cavitation bubbles was considered as control group.

Results

Fourty nine patients (M26/F23) with mean age of 46.5 ± 13.6 years were identify as having growth of the cavitation bubbles and a total of 325 echo studies were reviewed. All patients had mitral valve replacement but 4, that had only aortic mechanical valve. 43% had mitral-aortic valve replacement and 5 had 3 or 4 valves replaced. The follow-up period was of 3697 ± 2481 days, 52%±31% of the echo studies reviewed had growth of the cavitation bubbles.

At the time of the study systolic BP was 124 ± 12.5 vs 121.1 ± 16.4 mmHg, p = 0.1 (echo study with versus without growth cavitation respectively), diastolic 72.7 ± 10.1 vs 69.4 ± 14.9 mmHg, p= 0.2; HR 81.3 ± 19.4 vs 73.7 ± 14.1 bpm, p = 0.05. No statistical differences in trans mitral gradients were found between the two groups (peak 11.8 ± 3.9 vs 11.7 ± 4.3 mmHg, p = 0.7; mean 4.6 ± 1.9 vs 4.2 ± 1 mmHg.6p = 0.1). 33 TEE were performed and in 50% of cases because of suspecion of endocarditis. Only 2 TEE were positive for endocarditis and one positive for pannus and high gradients across the valve in addition to cavitation.

Conclusion

Cavitation phenomenon in mechanical valves, in particular mitral bi-leaflet valve is well known but growth of cavitation bubbles is seldom described. We found that this fenomenon is frequently present although not constant, is related with increased HR and can be responsible of misdiagnosis with endocarditis.

Abstract P806 Figure.