Category: Nevin Manimala

World Neurosurg. 2022 Mar 5:S1878-8750(22)00273-X. doi: 10.1016/j.wneu.2022.02.126. Online ahead of print.

ABSTRACT

OBJECTIVE: To evaluate the accuracy of using patient-specific drill guides to place bilateral laminar screws in C1 and C2.

METHODS: Nine cervical specimens (8 male; mean age: 66.6 (56-73)) with the occiput attached (C0-C3) were used in this study. Pre-operative CT scans were used to create digital anatomic models for templating and guide creation. A total of 36 screws were placed with the aid of 3D printed patient-specific guides (2 screws at C1 and C2). Post-operative CT scans were performed following screw insertion. The planned and actual trajectories were compared using pre- and post-operative imaging based on the angular and entry point deviation. After screw placement and post-operative imaging, each specimen was dissected and performed a visual inspection for breaches.

RESULTS: No breaches or violations were observed on post-procedure CT and visual inspection. The average variation of the entry point in the X, Y, and Z-axis was 0.3±0.28, 0.41±0.38, and 0.29±0.24, respectively. No statistically significant difference (p>0.05) was observed between the planned and obtained entry points. There was no significant difference (p>0.05) in the deviation analysis between the planned and obtained angles in the axial and coronal planes.

CONCLUSION: The study demonstrates that patient-specific drill guides allow for accurate C1 and C2 bilateral laminar screw placement, with a low risk of cortical breach.

PMID:35259502 | DOI:10.1016/j.wneu.2022.02.126

Clin Cancer Res. 2022 Mar 8:clincanres.4462.2021. doi: 10.1158/1078-0432.CCR-21-4462. Online ahead of print.

ABSTRACT

On August 25, 2021, the FDA approved ivosidenib for the treatment of adult patients with unresectable locally advanced or metastatic hepatocellular isocitrate-dehydrogenase-1 (IDH1) mutated cholangiocarcinoma (CCA) as detected by an FDA-approved test with disease progression after 1-2 prior lines of systemic therapy for advanced disease. The approval was based on data from Study AG120-C-005 (ClarIDHy), a double-blind placebo-controlled trial which randomly allocated (2:1) patients to receive either ivosidenib or placebo. Independently-assessed progression free survival (PFS) was the primary endpoint. With a median follow up of 6.9 months, the hazard ratio for PFS was 0.37 (95% confidence interval 0.25, 0.54, p< 0.0001). Overall survival (OS) was the key secondary endpoint. At the final analysis of OS, with 70.5% patients in the placebo arm receiving ivosidenib post disease progression, a non-statistically significant improvement in the ivosidenib arm with a HR = 0.79 (95% CI: 0.56, 1.12) and median OS of 10.3 months (95% CI 7.8, 12.4) and 7.5 months (95% CI 4.8, 11.1) in the ivosidenib and placebo arms respectively were reported. Adverse reactions occurring in >20% of patients receiving ivosidenib were fatigue/asthenia, nausea, diarrhea, abdominal pain, ascites, vomiting, cough, and decreased appetite. Adverse reactions occurring in >20% of patients receiving placebo were fatigue/asthenia, nausea, abdominal pain, and vomiting. This is the first approval for the subset of patients with CCA harboring an IDH1 mutation.

PMID:35259259 | DOI:10.1158/1078-0432.CCR-21-4462

PLoS One. 2022 Mar 8;17(3):e0265034. doi: 10.1371/journal.pone.0265034. eCollection 2022.

ABSTRACT

We analyzed data from a cohort of Black and Latino men who have sex with men (MSM) in order to identify correlates of prevalent and incident incarceration, including potential predictors related to their status as sexual and gender minorities (SGMs). Baseline and follow-up self-administered survey data were examined from Los Angeles County participants’ ages 18-45 years at enrollment who were either HIV negative or living with HIV, but recruited to over represent men who used drugs and men with unsuppressed HIV infection. Multivariable logistic regression models were developed to identify predictors of baseline incarceration history and of incident incarceration over study follow-up among 440 and 338 participants, respectively. Older age, Black race, low socioeconomic status, homelessness, stimulant use, and depression symptoms were associated with baseline incarceration history. The only SGM-related factor associated with baseline incarceration history was having experienced violence based on sexual orientation identity. Just one statistically significant, independent positive predictor of incident incarceration was identified: prior incarceration, whereas having four or more friends that could lend money was a statistically significant protective factor against incident incarceration. Fundamental Cause Theory provides a useful framework to explain identified predictors of incarceration. Addressing poverty, housing instability, inadequate access to health care, and their root causes is critical to reducing incarceration rates in this population, as is expanded access to both diversion and anti-recidivism programs and to evidence-based treatment for stimulant use disorders.

PMID:35259198 | DOI:10.1371/journal.pone.0265034

PLoS One. 2022 Mar 8;17(3):e0264993. doi: 10.1371/journal.pone.0264993. eCollection 2022.

ABSTRACT

CONTEXT: The prevalence of overweight and obesity in Saudi Arabia has been rising. Although the health burden of excess weight is well established, little is known about the economic burden.

AIMS: To assess the economic burden-both direct medical costs and the value of absenteeism and presenteeism-resulting from overweight and obesity in Saudi Arabia.

SETTINGS AND DESIGN: The cost of overweight and obesity in Saudi Arabia was estimated from a societal perspective using an epidemiologic approach.

METHODS AND MATERIALS: Data were obtained from previously published studies and secondary databases.

STATISTICAL ANALYSIS USED: Overweight/obesity-attributable costs were calculated for six major noncommunicable diseases; sensitivity analyses were conducted for key model parameters.

RESULTS: The impact of overweight and obesity for these diseases is found to directly cost a total of $3.8 billion, equal to 4.3 percent of total health expenditures in Saudi Arabia in 2019. Estimated overweight and obesity-attributable absenteeism and presenteeism costs a total of $15.5 billion, equal to 0.9 percent of GDP in 2019.

CONCLUSIONS: Even when limited to six diseases and a subset of total indirect costs, results indicate that overweight and obesity are a significant economic burden in Saudi Arabia. Future studies should identify strategies to reduce the health and economic burden resulting from excess weight in Saudi Arabia.

PMID:35259190 | DOI:10.1371/journal.pone.0264993

PLoS One. 2022 Mar 8;17(3):e0264944. doi: 10.1371/journal.pone.0264944. eCollection 2022.

ABSTRACT

Catatonia is a psychomotor abnormality caused by neurological, medical or severe psychiatric disorders and substances. Its prevalence ranges from less than 10% to just above 60%. Diagnosis may be influenced by the screening tools used. Screening of new admissions to a mental health unit for catatonia was undertaken using three instruments to determine prevalence of catatonia. Participants ranged from age 16 years and over. Recruitment took place from September 2020 to August 2021. The setting was a mental health unit within a general hospital in Nelson Mandela Metro, South Africa. Five assessors were trained by the principal investigator to apply the Bush Francis Screening Instrument (BFCSI), the Bush Francis Catatonia Rating Scale (BFCRS), and the Diagnostic and Statistical Manual 5 (DSM-5), to assess participants. Clinical and demographic data were collected using a specially designed datasheet. Data analysis was performed to identify significant associations between presence or absence of catatonia and clinical and demographic data. Up to 241 participants were screened and 44 (18.3%) had catatonia. All 44 cases were identified through the BFCSI while the DSM-5 identified only 16 (6.6%%) of the 44 cases even though the remaining 28 (63.6%) participants still required treatment for catatonic symptoms. The DSM-5 diagnostic criteria excluded staring, which was the commonest sign of catatonia identified through the BFCSI [n = 33 (75%)]. Close to half (21; 47.7%) of those with catatonia on the BFCSI had schizophrenia. The rest had bipolar disorder (12; 27.3%), substance-induced psychotic disorder (7; 15.9%) and no specified diagnosis in one (1; 2.6%). The BFCSI was very effective at identifying catatonia while the DSM-5 was inadequate, missing close to 64% (28 of 44) of cases. Predictors of catatonia in this sample were a younger age and being male. A prevalence of 18.3%, indicates that assessment for catatonia should be routinely conducted in this and similar settings.

PMID:35259194 | DOI:10.1371/journal.pone.0264944

PLoS One. 2022 Mar 8;17(3):e0264803. doi: 10.1371/journal.pone.0264803. eCollection 2022.

ABSTRACT

Traffic is one of the major contributors to PM2.5 in cities worldwide. Quantifying the role of traffic is an important step towards understanding the impact of transport policies on the possibilities to achieve cleaner air and accompanying health benefits. With the aim of estimating potential health benefits of eliminating traffic emissions, we carried out a meta-analysis using the World Health Organisation (WHO) database of source apportionment studies of PM2.5 concentrations. Specifically, we used a Bayesian meta-regression approach, modelling both overall and traffic-related (tailpipe and non-tailpipe) concentrations simultaneously. We obtained the distributions of expected PM2.5 concentrations (posterior densities) of different types for 117 cities worldwide. Using the non-linear Integrated Exposure Response (IER) function of PM2.5, we estimated percent reduction in different disease endpoints for a scenario with complete removal of traffic emissions. We found that eliminating traffic emissions results in achieving the WHO-recommended concentration of PM2.5 only for a handful of cities that already have low concentrations of pollution. The percentage reduction in premature mortality due to cardiovascular and respiratory diseases increases up to a point (30-40 ug/m3), and above this concentration, it flattens off. For diabetes-related mortality, the percentage reduction in mortality decreases with increasing concentrations-a trend that is opposite to other outcomes. For cities with high concentrations of pollution, the results highlight the need for multi-sectoral strategies to reduce pollution. The IER functions of PM2.5 result in diminishing returns of health benefits at high concentrations, and in case of diabetes, there are even negative returns. The results show the significant effect of the shape of IER functions on health benefits. Overall, despite the diminishing results, a significant burden of deaths can be prevented by policies that aim to reduce traffic emissions even at high concentrations of pollution.

PMID:35259180 | DOI:10.1371/journal.pone.0264803

PLoS One. 2022 Mar 8;17(3):e0264957. doi: 10.1371/journal.pone.0264957. eCollection 2022.

ABSTRACT

Physician stress is associated with near misses and adverse medical events. However, little is known about physiological mechanisms linking stress to such events. We explored the utility of machine learning to determine whether the catabolic stress hormone cortisol and the anabolic, anti-stress hormone dehydroepiandrosterone sulfate (DHEA-S), as well as the cortisol to DHEA-S ratio relate to near misses in emergency medicine residents during active duty in a trauma 1 emergency department. Compared to statistical models better suited for inference, machine learning models allow for prediction in situations that have not yet occurred, and thus better suited for clinical applications. This exploratory study used multiple machine learning models to determine possible relationships between biomarkers and near misses. Of the various models tested, support vector machine with radial bias function kernels and support vector machine with linear kernels performed the best, with training accuracies of 85% and 79% respectively. When evaluated on a test dataset, both models had prediction accuracies of around 80%. The pre-shift cortisol to DHEA-S ratio was shown to be the most important predictor in interpretable models tested. Results suggest that interventions that help emergency room physicians relax before they begin their shift could reduce risk of errors and improve patient and physician outcomes. This pilot demonstrates promising results regarding using machine learning to better understand the stress biology of near misses. Future studies should use larger groups and relate these variables to information in electronic medical records, such as objective and patient-reported quality measures.

PMID:35259166 | DOI:10.1371/journal.pone.0264957

PLoS One. 2022 Mar 8;17(3):e0263618. doi: 10.1371/journal.pone.0263618. eCollection 2022.

ABSTRACT

The observation and assessment of animal biodiversity using acoustic technology has developed considerably in recent years. Current eco-acoustic research focuses on automatic audio recorder arrays and acoustic indices, which may be used to study the spatial and temporal dynamics of local animal communities in high resolution. While such soundscapes have often been studied above ground, their applicability in soils has rarely been tested. For the first time, we applied acoustic and statistical methods to explore the spatial, diurnal, and seasonal dynamics of the soundscape in soils. We studied the dynamics of acoustic complexity in forest soils in the alpine Pfynwald forest in the Swiss canton of Valais and related them to meteorological and microclimatic data. To increase microclimatic variability, we used a long-term irrigation experiment. We also took soil samples close to the sensors on 6 days in different seasons. Daily and seasonal patterns of acoustic complexity were predicted to be associated with abiotic parameters-that is, meteorological and microclimatic conditions-and mediated by the dynamics of the diversity and activity of the soil fauna. Seasonal patterns in acoustic complexity showed the highest acoustic complexity values in spring and summer, decreasing in fall and winter. Diurnal acoustic complexity values were highest in the afternoon and lowest during the night. The measurement of acoustic diversity at the sampling site was significantly associated with soil communities, with relationships between taxa richness or community composition and acoustic complexity being strongest shortly before taking the soil samples. Our results suggest that the temporal and spatial dynamics of the diversity and community composition of soil organisms can be predicted by the acoustic complexity of soil soundscapes. This opens up the possibility of using soil soundscape analysis as a noninvasive and easy-to-use method for soil biodiversity monitoring programs.

PMID:35259175 | DOI:10.1371/journal.pone.0263618

PLoS Comput Biol. 2022 Mar 8;18(3):e1009557. doi: 10.1371/journal.pcbi.1009557. Online ahead of print.

ABSTRACT

Perception is often characterized computationally as an inference process in which uncertain or ambiguous sensory inputs are combined with prior expectations. Although behavioral studies have shown that observers can change their prior expectations in the context of a task, robust neural signatures of task-specific priors have been elusive. Here, we analytically derive such signatures under the general assumption that the responses of sensory neurons encode posterior beliefs that combine sensory inputs with task-specific expectations. Specifically, we derive predictions for the task-dependence of correlated neural variability and decision-related signals in sensory neurons. The qualitative aspects of our results are parameter-free and specific to the statistics of each task. The predictions for correlated variability also differ from predictions of classic feedforward models of sensory processing and are therefore a strong test of theories of hierarchical Bayesian inference in the brain. Importantly, we find that Bayesian learning predicts an increase in so-called “differential correlations” as the observer’s internal model learns the stimulus distribution, and the observer’s behavioral performance improves. This stands in contrast to classic feedforward encoding/decoding models of sensory processing, since such correlations are fundamentally information-limiting. We find support for our predictions in data from existing neurophysiological studies across a variety of tasks and brain areas. Finally, we show in simulation how measurements of sensory neural responses can reveal information about a subject’s internal beliefs about the task. Taken together, our results reinterpret task-dependent sources of neural covariability as signatures of Bayesian inference and provide new insights into their cause and their function.

PMID:35259152 | DOI:10.1371/journal.pcbi.1009557

PLoS Comput Biol. 2022 Mar 8;18(3):e1009925. doi: 10.1371/journal.pcbi.1009925. Online ahead of print.

ABSTRACT

A central goal in sensory neuroscience is to understand the neuronal signal processing involved in the encoding of natural stimuli. A critical step towards this goal is the development of successful computational encoding models. For ganglion cells in the vertebrate retina, the development of satisfactory models for responses to natural visual scenes is an ongoing challenge. Standard models typically apply linear integration of visual stimuli over space, yet many ganglion cells are known to show nonlinear spatial integration, in particular when stimulated with contrast-reversing gratings. We here study the influence of spatial nonlinearities in the encoding of natural images by ganglion cells, using multielectrode-array recordings from isolated salamander and mouse retinas. We assess how responses to natural images depend on first- and second-order statistics of spatial patterns inside the receptive field. This leads us to a simple extension of current standard ganglion cell models. We show that taking not only the weighted average of light intensity inside the receptive field into account but also its variance over space can partly account for nonlinear integration and substantially improve response predictions of responses to novel images. For salamander ganglion cells, we find that response predictions for cell classes with large receptive fields profit most from including spatial contrast information. Finally, we demonstrate how this model framework can be used to assess the spatial scale of nonlinear integration. Our results underscore that nonlinear spatial stimulus integration translates to stimulation with natural images. Furthermore, the introduced model framework provides a simple, yet powerful extension of standard models and may serve as a benchmark for the development of more detailed models of the nonlinear structure of receptive fields.

PMID:35259159 | DOI:10.1371/journal.pcbi.1009925