Convolutional spiking neural networks for intent detection based on anticipatory brain potentials using electroencephalogram

Spiking neural networks (SNNs) are receiving increased attention because they mimic synaptic connections in biological systems and produce spike trains, which can be approximated by binary values for computational efficiency. Recently, the addition of convolutional layers to combine the feature extraction power of convolutional networks with the computational efficiency of SNNs has been introduced. This paper studies the feasibility of using a convolutional spiking neural network (CSNN) to detect anticipatory slow cortical potentials (SCPs) related to braking intention in human participants using an electroencephalogram (EEG). Data was collected during an experiment wherein participants operated a remote-controlled vehicle on a testbed designed to simulate an urban environment. Participants were alerted to an incoming braking event via an audio countdown to elicit anticipatory potentials that were measured using an EEG. The CSNN's performance was compared to a standard CNN, EEGNet and three graph neural networks via 10-fold cross-validation. The CSNN outperformed all the other neural networks, and had a predictive accuracy of 99.06% with a true positive rate of 98.50%, a true negative rate of 99.20% and an F1-score of 0.98. Performance of the CSNN was comparable to the CNN in an ablation study using a subset of EEG channels that localized SCPs. Classification performance of the CSNN degraded only slightly when the floating-point EEG data were converted into spike trains via delta modulation to mimic synaptic connections.

Self-reported side effects of COVID-19 vaccines among health professions students in India

Studies focusing on the safety and common side effects of vaccines play a crucial role in enhancing public acceptance of vaccination. Research is scarce regarding the usage of COVID-19 vaccines and the side effects experienced by health professions students in India and other countries. This study aimed to document self-reported side effects associated with COVID-19 vaccination among medical and dental students of six medical and dental colleges and teaching hospitals in four states (Tamil Nadu, Madhya Pradesh, Gujarat, and West Bengal) of India. A cross-sectional survey using purposive sampling of medical and dental students was conducted from 26 April to 26 May 2021. Data was collected using a Google Forms questionnaire capturing information regarding receiving COVID-19 vaccines, side effects and symptoms, onset and duration of symptoms, use of treatment to alleviate symptoms, awareness of haematologic risks associated with vaccination, and side effects from previous (non-COVID-19) vaccinations. The majority (94.5%) of participants received both doses of the Covishield/AstraZeneca COVID-19 vaccine. Among participants (n = 492), 45.3% (n = 223) reported one or more side effects. The most frequently reported side effects were soreness of the injected arm (80.3%), tiredness (78.5%), fever (71.3%), headache (64.1%), and hypersomnia (58.7%). The two most common severe symptoms were fever (14.8%) and headache (13%). Most side effects appeared on the day of vaccination: soreness of the injection site (57%), fever (43.1%), and tiredness (42.6%). Most reported symptoms persisted for one to three days-soreness of the injection site (53%), fever (47.1%), and headache (42.6%). Logistic regression showed that women were almost 85% less likely to report side effects. The study's findings corroborate the safety of the Covishield/AstraZeneca vaccine's first dose, evidenced by the relatively minor and transient nature of the side effects. However, the study underscores the necessity for ongoing research to assess the long-term impacts of COVID-19 vaccines, especially in the context of booster doses, thereby contributing to the global understanding of vaccine safety and efficacy.

The nuclear import receptor Kapβ2 modifies neurotoxicity mediated by poly(GR) in C9orf72-linked ALS/FTD

Expanded intronic G4C2 repeats in the C9ORF72 gene cause amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). These intronic repeats are translated through a non-AUG-dependent mechanism into five different dipeptide repeat proteins (DPRs), including poly-glycine-arginine (GR), which is aggregation-prone and neurotoxic. Here, we report that Kapβ2 and GR interact, co-aggregating, in cultured neurons in-vitro and CNS tissue in-vivo. Importantly, this interaction significantly decreased the risk of death of cultured GR-expressing neurons. Downregulation of Kapβ2 is detrimental to their survival, whereas increased Kapβ2 levels mitigated GR-mediated neurotoxicity. As expected, GR-expressing neurons displayed TDP-43 nuclear loss. Raising Kapβ2 levels did not restore TDP-43 into the nucleus, nor did alter the dynamic properties of GR aggregates. Overall, our findings support the design of therapeutic strategies aimed at up-regulating Kapβ2 expression levels as a potential new avenue for contrasting neurodegeneration in C9orf72-ALS/FTD.

Knowledge, Attitudes, and Practices of Hand Hygiene, Mask Use, and Social Distancing among Public Hospital and Polyclinic Nurses in Barbados during the Coronavirus 2019 Pandemic

BACKGROUND

Nurses are essential members of the healthcare workforce and were among the first-line carers for patients in community and hospital settings during the COVID-19 pandemic. As a result, they were at a heightened risk of infection, resulting in several reported deaths among nursing staff. Several preventive measures were adopted to contain the spread of the COVID-19 virus. This study aims to explore the knowledge, attitudes, and practices (KAP) of nurses regarding hand hygiene, mask wearing, and social distancing measures in healthcare settings in Barbados during the COVID-19 pandemic.

METHOD

An online survey of nurses working in public hospitals and polyclinics (public primary care clinics) in Barbados from March 2021 to December 2021 was conducted. A nonsystematic convenience sampling method was employed to recruit nurses who were readily available and willing to participate. A questionnaire captured the sociodemographic information and knowledge and practices related to hand hygiene, the use of face masks, and social distancing. Each correct response received one mark. Overall knowledge scores were categorized as poor (<60%), average (60-80%), or good (>80-100%).

RESULTS

Of the 192 participants, the majority were female (82.8%) and had >5 years of experience (82%). The findings revealed that 45.8% had poor knowledge of hand hygiene, and that the knowledge of 43.8% of respondents was average. Multivariable logistic regression showed that, after adjustment for age and gender, registered nurses had 2.1 times increased odds (95% confidence interval 1.0, 4.2) of having good knowledge compared to other nursing categories. Regarding mask wearing, 53.6% of nurses had average knowledge, and 27.1% had good knowledge. Multivariable logistic regression showed that, after adjustment for age and gender, registered nurses had 3.3 times increased odds (95% confidence interval 1.5, 7.4) of having good knowledge compared to nursing assistants. A total of 68.6% of respondents followed the correct steps of handwashing every time, and 98.3% wore a mask in public places. More than half of the nurses (51.2%) kept a safe distance from others to avoid spreading SARS-CoV-2; one-third were in a crowded place(s) in the past three months, and 55.8% usually followed guidelines for social isolation as recommended by the WHO.

CONCLUSIONS

The study identified knowledge deficiencies related to hand hygiene and wearing masks among nurses. It is imperative to provide additional training on infection control measures.

C9orf72 poly(PR) mediated neurodegeneration is associated with nucleolar stress

The ALS/FTD-linked intronic hexanucleotide repeat expansion in the C9orf72 gene is aberrantly translated in the sense and antisense directions into dipeptide repeat proteins, among which poly proline-arginine (PR) displays the most aggressive neurotoxicity in-vitro and in-vivo. PR partitions to the nucleus when heterologously expressed in neurons and other cell types. We show that by lessening the nuclear accumulation of PR, we can drastically reduce its neurotoxicity. PR strongly accumulates in the nucleolus, a nuclear structure critical in regulating the cell stress response. We determined that, in neurons, PR caused nucleolar stress and increased levels of the transcription factor p53. Downregulating p53 levels also prevented PR-mediated neurotoxicity both in in-vitro and in-vivo models. We investigated if PR could induce the senescence phenotype in neurons. However, we did not observe any indications of such an effect. Instead, we found evidence for the induction of programmed cell death via caspase-3 activation.

C9orf72 poly(PR) mediated neurodegeneration is associated with nucleolar stress

The ALS/FTD-linked intronic hexanucleotide repeat expansion in the C9orf72 gene is translated into dipeptide repeat proteins, among which poly-proline-arginine (PR) displays the most aggressive neurotoxicity in-vitro and in-vivo . PR partitions to the nucleus when expressed in neurons and other cell types. Using drosophila and primary rat cortical neurons as model systems, we show that by lessening the nuclear accumulation of PR, we can drastically reduce its neurotoxicity. PR accumulates in the nucleolus, a site of ribosome biogenesis that regulates the cell stress response. We examined the effect of nucleolar PR accumulation and its impact on nucleolar function and determined that PR caused nucleolar stress and increased levels of the transcription factor p53. Downregulating p53 levels, either genetically or by increasing its degradation, also prevented PR-mediated neurotoxic phenotypes both in in-vitro and in-vivo models. We also investigated whether PR could cause the senescence phenotype in neurons but observed none. Instead, we found induction of apoptosis via caspase-3 activation. In summary, we uncovered the central role of nucleolar dysfunction upon PR expression in the context of C9-ALS/FTD.

Evaluation of Short-Term Side Effects Following the First Dose of COVID-19 Vaccines Among Physicians and Dentists: A Cross-Sectional Study from India

Background

Efficacy and safety are fundamental for the development of successful COVID-19 vaccines. Vaccine-associated side effects influence vaccine hesitancy. This study investigated the prevalence, severity, and onset of side effects following the first dose of COVID-19 vaccines among physicians and dentists working in various healthcare settings across India.

Methods

A cross-sectional survey collected self-report data from April to June 2021 on side effects following the first dose of the vaccine. An online validated questionnaire using the Google Docs^® platform was circulated via email and social media platforms.

Results

More than 40% of participants experienced at least one side effect after the first dose of vaccination; the most common were mild and resolved within three days after vaccination. More than 91% of respondents received the Covishield (AstraZeneca) vaccine; the most prevalent adverse effects were soreness of the injected arm (78.9%), tiredness (71.1%), and fever (54.9%). Logistic regression showed that women were almost 60% less likely to report side effects.

Conclusion

Findings supported the safety of the first dose of the COVID-19 vaccine based on relatively few self-limiting side effects, mainly soreness of the injected arm and tiredness. Further research is needed to determine the long-term safety of COVID-19 vaccines, especially after booster doses.

Personal protective equipment (PPE) related adverse skin reactions among healthcare workers at the main COVID-19 isolation center in Barbados

Background

The use of personal protective equipment (PPE) reduces the risk of transmission of infectious agents significantly among healthcare workers (HCWs). The study aimed to investigate the prevalence and characteristics of PPE-related adverse skin reactions among HCWs working at the main COVID-19 isolation center in Barbados.

Methods

A cross-sectional web-based online survey was conducted during April to June 2021 which recorded demographic information, details of PPE use and adverse skin reactions including severity and duration of onset of symptoms.

Results

Most of the respondents used PPE for consecutive days (77.9%), 1-6 h/day (59.2%), and more than a year (62.5%). Fewer than half of the participants (45.6%) experienced adverse skin reactions from the use of PPE. The reactions were mostly observed in the cheeks (40.4%) and nose bridges (35.6%). Females had more reactions than their male counterparts (p = 0.003). The use of N95 masks and a combination of surgical and N95 masks produced adverse effects predominantly in the ears (60%) and cheeks (56.4%). Binary logistic regression showed that female HCWs (OR = 5.720 95% CI: 1.631, 20.063), doctors (OR = 5.215 95% CI: 0.877, 31.002), and longer duration of PPE use (>1 year) (OR = 2.902 95% CI: 0.958, 8.787) caused a significantly higher prevalence of adverse skin reactions.

Conclusion

The PPE-related skin reactions were common among HCWs which mainly occurred due to prolonged use. Preventive measures inclusive of appropriate training of HCWs on the use of PPE are recommended to minimize these adverse events.

Benefits of gamification in medical education

Medical education is changing at a fast pace. Students attend medical school with a high degree of technological literacy and a desire for a diverse educational experience. As a result, a growing number of medical schools are incorporating technology-enhanced active learning and multimedia education tools into their curriculum. Gamified training platforms include educational games, mobile medical apps, and virtual patient scenarios. We provide a systematic review of what is meant by gamification in this era. Specific educational games, mobile apps, and virtual simulations that may be used for preclinical and clinical training have been discovered and classified. The available data were presented in terms of the recognized platforms for medical education's possible benefits. Virtual patient simulations have been shown to enhance learning results in general. Gamification could improve learning, engagement, and cooperation by allowing for real-world application. They may also help with promoting risk-free healthcare decision-making, remote learning, learning analytics, and quick feedback. We account for Preclinical training which included 5 electronic games and 4 mobile apps, while clinical training included 5 electronic games, 10 mobile applications, and 12 virtual patient simulation tools. There were additionally nine more gamified virtual environment training products that were not commercially accessible. Many of these studies have shown that utilizing gamified media in medical education may confer advantages. This collection of hyperlinked resources may be utilized by medical students, practitioners, and instructors at all levels.

Threshold of Inotropic Score and Vasoactive-Inotropic Score for Predicting Mortality in Pediatric Septic Shock

OBJECTIVE

To determine the threshold of the inotropic score (IS) and vasoactive-inotropic score (VIS) for predicting mortality in pediatric septic shock.

METHOD

This retrospective cohort study included children aged 1 mo to 13 y with septic shock, requiring vasoactive medication. The area under curve receiver operating characteristic (AUROC) was calculated using mean IS and mean VIS to predict PICU mortality, and Youden index cut points were generated. Sensitivity, specificity, and binary regression analysis were performed.

RESULTS

A total of 176 patients were enrolled (survivor, n = 72, 41% and nonsurvivor, n = 104, 59%). For predicting the PICU mortality, AUROC (95% CI) of IS was 0.80 (0.74-0.86) [sensitivity of 88.5 (80.7-94) and specificity of 58.3 (46.1-69.8)] and AUROC of VIS was 0.88 (0.82-0.92) [sensitivity of 83.7 (75.1-90.2) and specificity of 80.6 (69.5-89)]. The respective cutoff scores of IS and VIS were 28 and 42.5. On regression analysis (adjusted odds ratio, 95% CI), illness severity (PRISM-III) (1.12, 1.05-1.12), worst lactate value (1.31, 1.08-1.58), IS (> 28) (3.98, 1.24-12.80), and VIS (> 42.5) (4.66, 1.57-13.87) independently predicted the PICU mortality (r² = 0.625).

CONCLUSION

Threshold of inotropic score (> 28) and vasoactive-inotropic score (> 42.5) were independently associated with PICU mortality. In addition to IS and VIS, severity and worst lactate value independently predicted septic shock mortality in PICU.

Prospective Cohort Study on Cumulative Fluid Balance and Outcome in Critically Ill Children Using a Restrictive Fluid Protocol

OBJECTIVE

To study the association of cumulative fluid balance and clinical outcomes in a pediatric intensive care unit (PICU) practicing restrictive fluid protocol.

METHODS

In this prospective cohort study, children aged less than 13 y admitted for more than 48 h were screened. Children with unstable hemodynamics throughout the stay were excluded. Fluid balance was calculated by percentage fluid overload (%FO) for the first 7 d. Patients were divided into positive fluid and negative fluid balance groups. The primary outcome was all-cause 28-d mortality.

RESULTS

A total of 888 patients (positive fluid balance group = 531, negative fluid balance group = 357) were analyzed. Mean (SD) cumulative %FO was 1.52 (0.67) vs. -1.18 (0.71), p = < 0.001, and minimum and maximum cumulative %FO were -3.0% and 3.1%, respectively. There was no significant difference in all-cause 28-d mortality between the two groups (n = 104/531, 19.6% vs. n = 60/357, 16.8%, RR = 1.17, 95% CI 0.87 to 1.55; p = 0.29). There was no difference in organ dysfunction [mean (SD) sequential organ failure assessment (SOFA) score 3.3 (0.7) vs. 3.3 (0.6)], acute kidney injury (65% vs. 63.6%), need for renal replacement therapy (14% vs. 13%), and duration of ventilation (median, IQR 4, 2-6 vs. 4, 2-6 d). Longer stay in PICU (5, 3-9 vs. 4, 3-7 d; p = 0.014) and in hospital (8, 5-11 vs. 7, 4-10 d; p = 0.007) were noted in the positive fluid balance group.

CONCLUSION

Cumulative fluid balance within 3% using restrictive fluid protocol was not associated with a significant difference in PICU mortality and morbidity.

Multimodal Ensemble Deep Learning to Predict Disruptive Behavior Disorders in Children

Oppositional defiant disorder and conduct disorder, collectively referred to as disruptive behavior disorders (DBDs), are prevalent psychiatric disorders in children. Early diagnosis of DBDs is crucial because they can increase the risks of other mental health and substance use disorders without appropriate psychosocial interventions and treatment. However, diagnosing DBDs is challenging as they are often comorbid with other disorders, such as attention-deficit/hyperactivity disorder, anxiety, and depression. In this study, a multimodal ensemble three-dimensional convolutional neural network (3D CNN) deep learning model was used to classify children with DBDs and typically developing children. The study participants included 419 females and 681 males, aged 108–131 months who were enrolled in the Adolescent Brain Cognitive Development Study. Children were grouped based on the presence of DBDs (n = 550) and typically developing (n = 550); assessments were based on the scores from the Child Behavior Checklist and on the Schedule for Affective Disorders and Schizophrenia for School-age Children-Present and Lifetime version for DSM-5. The diffusion, structural, and resting-state functional magnetic resonance imaging (rs-fMRI) data were used as input data to the 3D CNN. The model achieved 72% accuracy in classifying children with DBDs with 70% sensitivity, 72% specificity, and an F1-score of 70. In addition, the discriminative power of the classifier was investigated by identifying the cortical and subcortical regions primarily involved in the prediction of DBDs using a gradient-weighted class activation mapping method. The classification results were compared with those obtained using the three neuroimaging modalities individually, and a connectome-based graph CNN and a multi-scale recurrent neural network using only the rs-fMRI data.

COVID-19 Vaccine Intent Among Health Care Professionals of Queen Elizabeth Hospital, Barbados

INTRODUCTION

Due to increased exposure risk and the potential impact of COVID-19 infection, health care professionals (HCP) are a target group for COVID-19 vaccination. This study aimed to examine the acceptability of COVID-19 vaccines among HCP at the Queen Elizabeth Hospital, Barbados.

DESIGN AND METHODS

A cross-sectional survey of HCP was conducted between February 14 and 27, 2021 using an online questionnaire. The questionnaire included demographic information, knowledge of novel coronavirus, intention to accept the COVID-19 vaccination, vaccine literacy (VL), and perceptions and attitudes regarding COVID-19 vaccines. Mean VL scores were calculated. The relationship between socio-demographic variables and vaccine intent was assessed using a multivariable logistic regression model.

RESULTS

Of 343 HCPs, 55.1% indicated they would accept the COVID-19 vaccine if it were available; 44.9% expressed hesitancy towards the COVID-19 vaccine. We assessed the impact of socio-demographic factors and previous vaccine behavior on vaccine intent; after adjustment of the multivariable logistic regression model, non-Barbadian nationality and previous flu vaccine uptake were statistically significant predictors of reported intent to take the COVID-19 vaccine. Persons who indicated that they would take the vaccine had a higher mean vaccine literacy score [3.46 95% CI (3.40, 3.52)] than those who were not ready to take the vaccine immediately [3.23 95% CI (3.15, 3.30)]. VL scores were higher among the 29.5% of HCPs who believed vaccines should be mandatory.

CONCLUSION

This study highlighted vaccine hesitancy among HCPs in the sole public tertiary hospital of Barbados. As HCP perceptions may help or hinder the campaign to promote vaccine uptake in Barbados, vaccine promotion programs targeting HCPs are needed to ensure the success of the country's COVID-19 vaccination drive.

Genetics of intervertebral disc disease: A review

Intervertebral disc disease (IVDD) is a common musculoskeletal disease affecting about 5% of all individuals. It is characterized by lumbar disc herniation, which causes nerve root irritation, either mechanically or via inflammatory mediators, and results in radiating pain, known as sciatica. Numerous studies have been conducted to identify the causes and risk factors for IVDD. Lifting heavy loads, torsional stress, and motor vehicle driving are among the best-identified environmental risk factors. However, it has become evident recently from family and twin studies that genetic factors may also be important in IVDD. This hypothesis was strengthened by the identification of two collagen IX alleles associated with sciatica and lumbar disc herniation. In addition, disc degeneration has been shown to be related to an aggrecan gene polymorphism, a Vitamin D receptor and matrix metalloproteinase-3 gene alleles. This review highlights the genetic role and occupational aspects of IVDD.

High COVID-19 Vaccine Hesitancy Among Healthcare Workers: Should Such a Trend Require Closer Attention by Policymakers?

Background The newly developed coronavirus disease 2019 (COVID-19) vaccines are considered to be a powerful tool to contain the devastating pandemic. Healthcare workers (HCWs) are at the highest risk of exposure to COVID-19 and, therefore, they are the priority group for vaccination. Objectives The study aimed to examine the perceptions, attitudes, and acceptability of the COVID-19 vaccination among HCWs in India. Study design A cross-sectional pilot survey was conducted using an online questionnaire between 13 and 25 January 2021. Results Among 264 respondents, 40.2% of HCWs would receive the vaccine against COVID-19 if available and 32.2% were willing to take the vaccine after observing adverse effects in others. Infected members in the immediate social network (OR:2.15; 95%CI:0.426-10.844), COVID-19 knowledge (OR:5.113; 95%CI:0.974-26.853), the safety of vaccines (OR:7.608; 95%CI:2.618-22.11), and those who did not receive a flu vaccine last year (OR:2.612; 95%CI:1.120-6.091) were found to have a statistically significant association with vaccine acceptance. The main reasons to delay/refuse vaccination included: 'quick vaccine development and compromised quality' (43.7%) and 'lack of trusted information regarding COVID-19' (41.3%). Conclusions The finding showed a high rate of vaccine hesitancy among HCWs. Policymakers should take steps to increase public awareness and secure timely and affordable vaccines for the HCWs and general population with effective vaccine promotion campaigns.

Novel Corona Virus Pandemic and Neonatal Care: It's Too Early to Speculate on Impact!

The entire world is reeling under the effects of the novel corona virus pandemic. As it is a new infection, our knowledge is evolving constantly. There is limited information about impact of corona virus on neonatal care in relation to newborns with confirmed or suspected COVID-19. In this article, we summarize the current approach to this infection in relation to newborn babies. We discuss the basic aspects of the infection, the approach of care to novel corona virus disease 2019 (COVID-19) in positive pregnant women, the likely presentation in newborns (as per current knowledge), and the approach to the management of neonates with infection or at risk of the infection. Children are less susceptible to COVID-19 infection and generally have a mild course. There is a lower risk of severe disease among pregnant women and neonates. It was recommended to follow the current protocols for management of symptomatic newborn with isolation precautions, antibiotics, and respiratory support.

Proposal of Research Model for the Detection of COVID-19 among Asymptomatic Carriers

Coronavirus disease 2019 (COVID-19) is a pandemic and rapidly progressing infectious disease that represents a global health care emergency due to severe acute respiratory syndrome. Rapid tests detect antigen or antibody presence, which is useful for patient care and for assisting in disease surveillance and epidemiological research. The complicating aspect of the COVID-19 spread may be due to asymptomatic individuals. Unfortunately, asymptomatic individuals are not detected in the early stages of infection, which could help to prevent community spread. The present paper shares an opinion through the proposal of a research model for detecting COVID-19 among asymptomatic carriers.

A Study of Brain Neuronal and Functional Complexities Estimated Using Multiscale Entropy in Healthy Young Adults

Brain complexity estimated using sample entropy and multiscale entropy (MSE) has recently gained much attention to compare brain function between diseased or neurologically impaired groups and healthy control groups. Using resting-state functional magnetic resonance imaging (rfMRI) blood oxygen-level dependent (BOLD) signals in a large cohort (n = 967) of healthy young adults, the present study maps neuronal and functional complexities estimated by using MSE of BOLD signals and BOLD phase coherence connectivity, respectively, at various levels of the brain’s organization. The functional complexity explores patterns in a higher dimension than neuronal complexity and may better discern changes in brain functioning. The leave-one-subject-out cross-validation method is used to predict fluid intelligence using neuronal and functional complexity MSE values as features. While a wide range of scales was selected with neuronal complexity, only the first three scales were selected with functional complexity. Fewer scales are advantageous as they preclude the need for long BOLD signals to calculate good estimates of MSE. The presented results corroborate with previous findings and provide a baseline for other studies exploring the use of MSE to examine changes in brain function related to aging, diseases, and clinical disorders.

Comparative analysis of margin status in breast conservation surgery and its correlation with subsequent re-excision findings

Purpose

Breast-conservation surgery (BCS) has become a standard treatment option for invasive breast carcinoma (IBC) and ductal carcinoma in situ (DCIS). The strongest predictor of local recurrence remains the surgical margin status. We evaluated the margin positivity by quantifying the tumor on positive margins and analyzing the histologic factors including type and extent in determining the likelihood of residual disease upon re-excision.

Method

Retrospective analysis of 210 BCS performed at Mount Sinai Medical Center from the period of January 2011 - December 2017 revealed that 58 had IBC, DCIS, or both, with positive margins that were followed by re-excision.

Result

The margins had IBC in 18 (31%), DCIS in 32 (55.2%) and both in 8 (13%) cases. Thirty-eight cases (65.5%) were free of carcinoma on re-excision. Of 40 cases with margins positive for DCIS, 16 (40%) had residual DCIS. Of 26 cases with IBC at the margins, and 5 had residual disease (19%). This difference was statistically significant (p = 0.002). Of 21 cases with extensive DCIS, 12 had residual disease (p = 0.02) as compared to only 4 out of 19 without extensive DCIS. None of the cases with clinging/micro-papillary DCIS had residual disease, while 51% of the other types (solid, cribriform, come-do) had residual disease (p = 0.02). The area of DCIS as measured on the involved margin correlated with the amount of residual disease on re-excision (p = 0.03).

Conclusion

Margins positive for DCIS are more likely to have residual disease on re-excision in comparison to margins positive for only IBC. The type and extent of DCIS appears to influence the likelihood of residual disease.

An evaluative study of objective structured clinical examination (OSCE): students and examiners perspectives

Background: The objective structured clinical examination (OSCE) is the gold standard and universal format to assess the clinical competence of medical students in a comprehensive, reliable and valid manner. The clinical competence is assessed by a team of many examiners on various stations of the examination. Therefore, it is found to be a more complex, resource- and time-intensive assessment exercise compared to the traditional examinations. Purpose: The objective of this study was to determine the final year MBBS students' and OSCE examiners' perception on the attributes, quality, validity, reliability and organization of the Medicine and Therapeutics exit OSCE held at the University of the West Indies (Cave Hill) in June 2017. Methods: At the end of the OSCE, students and examiners were provided with a questionnaire to obtain their views and comments about the OSCE. Due to the ordinal level of data produced by the Likert scale survey, statistical analysis was performed using the median, IQR and chi-square. Results: A total of 52 students and 22 examiners completed the questionnaire. The majority of the students provided positive views regarding the attributes (eg, fairness, administration, structure, sequence, and coverage of knowledge/clinical skills), quality (eg, awareness, instructions, tasks, and sequence of stations), validity and reliability (eg, true measure of essential clinical skills, standardized, practical and useful experiences), and organization (eg, orientation, timetable, announcements and quality of examination rooms) of the OSCE. Similarly, majority of the examiners expressed their satisfaction with organization, administration and process of OSCE. However, students expressed certain concerns such as stressful environment and difficulty level of OSCE. Conclusion: Overall, the OSCE was perceived very positively and welcomed by both the students and examiners. The concerns and challenges regarding OSCE can be overcome through better orientation of the faculty and preparation of the students for the OSCE.

A Comparison of Static and Dynamic Functional Connectivities for Identifying Subjects and Biological Sex Using Intrinsic Individual Brain Connectivity

Functional magnetic resonance imaging has revealed correlated activities in brain regions even in the absence of a task. Initial studies assumed this resting-state functional connectivity (FC) to be stationary in nature, but recent studies have modeled these activities as a dynamic network. Dynamic spatiotemporal models better model the brain activities, but are computationally more involved. A comparison of static and dynamic FCs was made to quantitatively study their efficacies in identifying intrinsic individual connectivity patterns using data from the Human Connectome Project. Results show that the intrinsic individual brain connectivity pattern can be used as a 'fingerprint' to distinguish among and identify subjects and is more accurately captured with partial correlation and assuming static FC. It was also seen that the intrinsic individual brain connectivity patterns were invariant over a few months. Additionally, biological sex identification was successfully performed using the intrinsic individual connectivity patterns, and group averages of male and female FC matrices. Edge consistency, edge variability and differential power measures were used to identify the major resting-state networks involved in identifying subjects and their sex.

Evaluation of Metabolic Syndrome and Vitamin D Receptor Gene Polymorphism in Male Factor Infertility

Male factor infertility (MFI) is a growing health issue in society. The vitamin D receptor gene (VDR) is expressed in many tissues and modulates expression of several other genes. The purpose of this study was to investigate the association between MetSyn, VDR gene (FokI, rs-2228570; C > T) polymorphisms and MFI in Indian adults. Fifty cases and fifty-four controls, fulfilling inclusion and exclusion criteria, were included with their informed consent. Fasting plasma glucose, triglyceride, HDL-C were estimated by clinical chemistry analyzer (Beckmam Coulter DXC 800, USA). Serum insulin was measured by electrochemiluminescence immunoassay and VDR gene polymorphism by RFLP-PCR. Statistical analysis was done using SPSS 20.0. MetSyn was more frequent in MFI cases than controls. There was significant difference between waist circumference, fasting plasma glucose, triglycerides in MFI cases and controls. There was significant difference in HOMA-IR between MFI cases and controls (p value < 0.05) and serum insulin was significantly raised in MFI cases (p value < 0.05). VDR gene polymorphism was found to be associated with MFI cases as compared to controls and the serum level of vitamin D was also decreased in MFI cases than in controls (p value < 0.05). This study provides evidence that insulin resistance is more in MFI cases than in controls and occurrence of MetSyn and its components is higher in MFI cases than in controls. Our findings provide evidence that VDR gene (FokI, rs-2228570; C > T) polymorphism increases the risk of male factor infertility.

Exploring the Role of the Public and Private Funded Primary Health Care Facilities for Children in a Pluralistic Health Care Setting of Barbados: One of the English Caribbean Countries

Background:

The major objectives of this study were to evaluate the existing primary health care service provisions in the public and private sector and utilization of the services, and to assess the existing manpower and material resources.

Methods:

Data were collected through interviews with the primary health care providers. Data were also collected from the records maintained at the polyclinics and the Ministry of Health Statistics. An analysis and discussion of all the available data was conducted to develop a comprehensive primary health care service utilization and resources inventory at the polyclinics. Similar data were collected from the primary care providers in the private sector.

Results:

In the public sector, there are 8 polyclinics that provide primary health care to the children. All the polyclinics have immunization services and curative acute care. Some of the polyclinics have a range of services, including dental care, eye care, and rehabilitative care services that common to both adults and children. In the private sector, primary health care is delivered through the 76 private office and of the individual physicians and 11 grouped private practices. All of the private offices and group practices have curative acute care for children and some of the offices have immunization services. Over all 87.5% of all the immunizations were done at the polyclinics. Over all 60.1% of acute care visits were to the private sector and 39.9% to the public sector. In the public sector, 59.5% were under 5 years children while 40.5% were 5 years or older. The corresponding figures in the private care settings were 80.9% and 11.9%.

Conclusions:

The findings demonstrate the complimentary role of the public and the private sector in the primary health care of children in this country. While the private sector has a major role in the curative acute care of children, the public sector plays a pivotal role in the immunization services.

The clinical characteristics and outcome of children hospitalized with dengue in Barbados, an English Caribbean country

INTRODUCTION

Although dengue is endemic in all English-speaking Caribbean countries, there are no published studies on the clinical presentations and outcomes of children hospitalized with dengue from this region. This study aims to assess the clinical charcteristics and the outcome in children hospitalized with dengue.

METHODS

This was a population-based prospective study of all the children hospitalized with confirmed dengue in 2009 in Barbados. All children suspected to have dengue were routinely screened for dengue infection and underwent routine blood tests. Relevant data was extracted from their case files at the time of their discharge from the hospital.

RESULTS

Of the 199 children who were hospitalized with suspected dengue, 115 (58%) were confirmed. The overall incidence rate of  dengue among children that required hospitalization was 2.1/1,000 children. Besides the typical clinical features of dengue, 64 children hospitalized with confirmed dengue also presented with gastrointestinal manifestations (56%), 39 with respiratory manifestations (51%), 11 with hepatic manifestations (10%), 8 with neurologic manifestations (7%), and 7 with cardiovascular manifestations (6%). Twenty (17.4%) children hospitalized with confirmed dengue met the criteria for the diagnosis of severe dengue. The other 82.6% had uncomplicated or non-severe (53.9% had dengue and 28.7% had dengue with warning signs) forms of dengue. The case fatality rate in this series was 1.7%.

CONCLUSIONS

Less than a third of all the children with confirmed dengue required hospitalization. Atypical clinical manifestations were common, and only a minority of these children had severe dengue. Overall, the case fatality rate for dengue in this select population of children hospitalized with dengue was low.

Selected enteropathogens and clinical course in children hospitalized with severe acute gastroenteritis in Barbados

OBJECTIVES

The primary aim of this study was to determine the prevalence of selected bacterial and viral enteropathogens in children hospitalized with acute gastroenteritis and the secondary aim was to characterize the clinical course and the outcome.

METHODOLOGY

A retrospective audit of children (<15 years) admitted with acute gastroenteritis during January 2008 to October 2010. Stool samples were analyzed for bacterial pathogens and for the Rotavirus. Demographics, clinical presentations, hospital course and outcome were extracted from the admission records.

RESULTS

There were 571 children hospitalized with acute gastroenteritis, which accounted for 11% of all medical hospitalization in children. Overall, 42.9% of these children were ≤12 months in age. Stool test result was documented in 46.6% of children hospitalized with gastroenteritis and an enteropathogen was isolated in 36.8% of cases with documented stool test result. Non-typhoidal Salmonella species was the most commonly isolated enteropathogen accounting for 21.1% of all the documented cases. Rotavirus was identified as an etiological agent in 9.0%. Of the 56 children who had non-typhoidal salmonella gastroenteritis, 54(96.4%) were younger than 5 years. The median duration of hospitalization was 2 days (Range 1 day to 9 days). There were no deaths.

CONCLUSION

Non-typhoidal salmonella was the most common enteropathogen isolated and this was followed by the Rotavirus.

Boerhaave's syndrome: a differential diagnosis of acute chest pain following a vomiting illness

Spontaneous oesophageal rupture (Boerhaave's syndrome) is extremely rare in children. Presentation is usually in middle aged men as a result of vomiting following heavy food or alcohol consumption. We describe an unusual case of a 12-year old boy without significant past medical history presenting with acute chest pain following gastroenteritis.

Deciphering the key molecular and cellular events in neutrophil transmigration during acute inflammation

Recruitment of leukocytes circulating in our blood to the sites of infection or tissue damage is the key phenomenon in the acute inflammatory response(s). Among the leukocytes, neutrophils are primarily recruited into the areas of acute inflammation. When neutrophils interact with activated endothelium of the blood vessels, they become migratory and cross the endothelial layer of the blood vessel wall in a process called as leukocyte extravasation. Identifying and understanding the gene regulation of this extravasation phenomenon is one of the key objective of biomedical research aimed at ameliorating or alleviating the symptoms of various diseases, such as rheumatoid arthritis, asthma, anaphylaxis, atherosclerosis, ulcerative colitis etc., that are exacerbated by inappropriate inflammatory stimuli. Here, we decipher and discuss the key genes implicated in the leukocyte transmigration using the acute inflammation model called as the Dextran Sulphate Sodium (DSS) induced Colitis in mice as a classic paradigm.

Validation of Pediatric Index of Mortality-2 scoring system in a pediatric intensive care unit, Barbados

This study evaluated the outcome of patients in a pediatric intensive care unit (ICU) of a developing country applying Pediatric Index of Mortality (PIM) version-2 scoring system. A total of 163 consecutive patients were prospectively studied. Data included demographics, diagnoses at admission, PIM-2 score, the duration of ICU stay and hospital outcome. Predicted mortality and standardized mortality ratio (SMR) were calculated. Respiratory and neurological illnesses were the main admission diagnoses. The mean length of stay was 5.4 [95% Confidence Intervals (CI): 4-6.9] days. The mean predicted mortality was 6.2% (95% CI: 4.3-8.1); the observed mortality rate was 5.5%, the SMR being 0.89. Hosmer-Lemeshow analysis calibrated PIM-2 for the case mix [χ(2) = 5.64 (df = 7), p = 0.58]. The area under the ROC curve was 0.82 (95% CI: 0.72-0.92) showing a good discriminant function. Performance of the pediatric ICU in Barbados is comparable to that of developed world by risk-adjusted outcome evaluation.

Formulation and initial experience on patient specific quality assurance for clinical implementation of dynamic IMRT

Intensity modulated radiotherapy (IMRT) is an advanced form of 3D conformal radiotherapy combining several intensity modulated beams to deliver the prescribed dose to the target with precision, sparing the adjacent normal tissue structures. The complex nature of IMRT delivery needs a precise patient specific quality assurance (QA), proper verification of dosimetry and treatment. QA procedures are important measures to ensure that the treatment can be delivered according to the treatment plan. In this report, we are presenting a formulation of a proposed protocol and results of patient specific QA carried on two IMRT plans. The QA consists of an absolute dosimetry, film dosimetry and dynalog files verification of treatment plans. The absolute doses, planar and fluence doses calculated by the TPS are compared with the measured values. The dynalog files recorded during the treatment delivery of two plans were analysed. The measured error in absolute dose is <3% in both the plans. An average of >98% of counts are having <0.1 cm errors in dMLC positions. The average RMS value of leaf motions is <0.05 cm in both the cases. The errors in film dosimetry are <3%. All the results obtained are comparable to the standard values and well within the acceptable limits. The paper outlines the minimum procedures required for the patient specific QA measurements for the clinical implementation of IMRT. The measurements help to understand and confirm the accuracy of IMRT delivery system.

Extrapolation chamber mounted on perspex for calibration of high energy photon and electron beams from a clinical linear accelerator

The objective of the present study is to establish radiation standards for absorbed doses, for clinical high energy linear accelerator beams. In the nonavailability of a cobalt-60 beam for arriving at Nd, water values for thimble chambers, we investigated the efficacy of perspex mounted extrapolation chamber (EC) used earlier for low energy x-rays and beta dosimetry. Extrapolation chamber with facility for achieving variable electrode separations 10.5mm to 0.5mm using micrometer screw was used for calibrations. Photon beams 6 MV and 15 MV and electron beams 6 MeV and 15 MeV from Varian Clinac linacs were calibrated. Absorbed Dose estimates to Perspex were converted into dose to solid water for comparison with FC 65 ionisation chamber measurements in water. Measurements made during the period December 2006 to June 2008 are considered for evaluation. Uncorrected ionization readings of EC for all the radiation beams over the entire period were within 2% showing the consistency of measurements. Absorbed doses estimated by EC were in good agreement with in-water calibrations within 2% for photons and electron beams. The present results suggest that extrapolation chambers can be considered as an independent measuring system for absorbed dose in addition to Farmer type ion chambers. In the absence of standard beam quality (Co-60 radiations as reference Quality for Nd,water) the possibility of keeping EC as Primary Standards for absorbed dose calibrations in high energy radiation beams from linacs should be explored. As there are neither Standard Laboratories nor SSDL available in our country, we look forward to keep EC as Local Standard for hospital chamber calibrations. We are also participating in the IAEA mailed TLD intercomparison programme for quality audit of existing status of radiation dosimetry in high energy linac beams. The performance of EC has to be confirmed with cobalt-60 beams by a separate study, as linacs are susceptible for minor variations in dose output on different days.

Effects of pulsed UV-light on peanut allergens in extracts and liquid peanut butter

Pulsed ultraviolet (PUV) light, a nonthermal technology, was used to treat both the peanut extracts and liquid peanut butter. The objective was to determine if such treatment would lead to a reduction in the allergenic properties of the peanut extract and butter. Peanut samples were PUV treated using a Xenon RS-3000C under the following conditions: 3 pulses/s, 14.6 cm from the central axis of the lamp, 4 min (extract) or 3 min (liquid peanut butter). After the treatment, the peanut samples were centrifuged and the supernatants analyzed by SDS-PAGE and competitive inhibition enzyme-linked immunosorbent assay (ciELISA). For comparison, boiling treatments were also performed. SDS-PAGE showed that while boiling treatment had little effect on the peanut allergens, PUV-light-treated samples displayed a reduced solubility or level of peanut allergens (63 kDa). Solubility of another allergen (18 to 20 kDa) was unaffected. Insoluble aggregates formed were responsible for the reduced level of allergens in PUV-light-treated samples. ciELISA showed that untreated samples exhibited an IgE binding 7-fold higher than the PUV-treated samples. It was concluded that PUV light was effective in reducing IgE binding of peanut extracts and liquid peanut butter. The current study provides an approach to the development of a possibly less allergenic peanut product. However, the reduction in actual allergenicity needs to be confirmed by clinical studies.

A method for estimation of accuracy of dose delivery with dynamic slit windows in medical linear accelerators

Intensity-modulated radiotherapy (IMRT) clinical dose delivery is based on computer-controlled multileaf movements at different velocities. To test the accuracy of modulation of the beam periodically, quality assurance (QA) methods are necessary. Using a cylindrical phantom, dose delivery was checked at a constant geometry for sweeping fields. Repeated measurements with an in-house designed methodology over a period of 1 year indicate that the method is very sensitive to check the proper functioning of such dose delivery in medical linacs. A cylindrical perspex phantom with facility to accurately position a 0.6-cc (FC 65) ion chamber at constant depth at isocenter, (SA 24 constancy check tool phantom for MU check, Scanditronix Wellhofer) was used. Dosimeter readings were integrated for 4-mm, 10-mm, 20-mm sweeping fields and for 3 angular positions of the gantry periodically. Consistency of standard sweeping field output (10-mm slit width) and the ratios of outputs against other slit widths over a long period were reported. A 10-mm sweeping field output was found reproducible within an accuracy of 0.03% (n = 25) over 1 year. Four-millimeter, 20-mm outputs expressed as ratio with respect to 10-mm sweep output remained within a mean deviation of 0.2% and 0.03% respectively. Outputs at 3 gantry angles remained within 0.5%, showing that the effect of dynamic movements of multileaf collimator (MLC) on the output is minimal for angular positions of gantry. This method of QA is very simple and is recommended in addition to individual patient QA measurements, which reflect the accuracy of dose planning system. In addition to standard output and energy checks of linacs, the above measurements can be complemented so as to check proper functioning of multileaf collimator for dynamic field dose delivery.

Clinical implementation of dynamic intensity-modulated radiotherapy: Dosimetric aspects and initial experience

This paper describes the initial experience of quality assurance (QA) tests performed on the millennium multi-leaf collimator (mMLC) for clinical implementation of intensity-modulated radiotherapy (IMRT) using sliding window technique. The various QA tests verified the mechanical and dosimetric stability of the mMLC of linear accelerator when operated in dynamic mode (dMLC). The mechanical QA tests also verified the positional accuracy and kinetic properties of the dMLC. The stability of dMLC was analyzed qualitatively and quantitatively using radiographic film and Omnipro IMRT software. The output stability, variation in output for different sweeping gap widths, and dosimetric leaf separation were measured. Dose delivery with IMRT was verified against the dose computed by the treatment planning system (TPS). Monitor units (MUs) calculated by the planning system for the IMRT were cross-checked with independent commercial dose management software. Visual inspection and qualitative analysis showed that the leaf positioning accuracy was well within the acceptable limits. Dosimetric QA tests confirmed the dosimetric stability of the mMLC in dynamic mode. The verification of MUs using commercial software confirmed the reliability of the IMRT planning system for dose computation. The dosimetric measurements validated the fractional dose delivery.

Inactivation of Staphylococcus aureus in milk using flow-through pulsed UV-light treatment system

This study investigated the efficacy of pulsed UV-light for continuous-flow milk treatment for the inactivation of Staphylococcus aureus, a pathogenic microorganism frequently associated with milk safety concerns. Pulsed UV light is an emerging technology, which can be used for the inactivation of this pathogen in milk in a relatively short time. Pulsed UV light damages the DNA of the bacteria by forming thymine dimers that lead to bacterial death. The effect of sample distance from the quartz window of the UV-light source, number of passes, and flow rate was investigated. A response surface methodology was used for the design and analysis of experiments. Milk was treated at 5-, 8-, or 11-cm distance from a UV-light strobe at 20, 30, or 40 mL/min flow rate and treated up to 3 times by recirculation of milk to assess the effect of the number of passes on inactivation efficiency. Log10 reductions varied from 0.55- to 7.26-log10 CFU/mL. Complete inactivation was obtained in 2 cases and no growth was observed following an enrichment protocol. Predicted results were in agreement with the experimental data. Overall, this work demonstrates that pulsed UV-light has a potential for inactivation of milk pathogens.