Tag: pubmed

Bull Math Biol. 2022 May 22;84(7):69. doi: 10.1007/s11538-022-01022-6.

ABSTRACT

Model discovery methods offer a promising way to understand biology from data. We propose a method to learn biological dynamics from spatio-temporal data by Gaussian processes. This approach is essentially “equation free” and hence avoids model derivation, which is often difficult due to high complexity of biological processes. By exploiting the local nature of biological processes, dynamics can be learned with data sparse in time. When the length scales (hyperparameters) of the squared exponential covariance function are tuned, they reveal key insights of the underlying process. The squared exponential covariance function also simplifies propagation of uncertainty in multi-step forecasting. After evaluating the performance of the method on synthetic data, we demonstrate a case study on real image data of E. coli colony.

PMID:35598223 | DOI:10.1007/s11538-022-01022-6

Bull Math Biol. 2022 May 22;84(7):68. doi: 10.1007/s11538-022-01023-5.

ABSTRACT

Host diversification methods such as within-field mixtures (or field mosaics, depending on the spatial scale considered) are promising methods for agroecological plant disease control. We explore disease spread in host mixtures (or field mosaics) composed of two host genotypes (susceptible and resistant). The pathogen population is composed of two genotypes (wild-type and resistance-breaking). We show that for intermediate fractions of resistant hosts, the spatial spread of the disease may be split into two successive fronts. The first front is led by the wild-type pathogen and the disease spreads faster, but at a lower prevalence, than in a resistant pure stand (or landscape). The second front is led by the resistance-breaking type, which spreads slower than in a pure resistant stand (or landscape). The wild-type and the resistance-breaking genotypes coexist behind the invasion fronts, resulting in the same prevalence as in a resistant pure stand. This study shows that host diversification methods may have a twofold effect on pathogen spread compared to a resistant pure stand (or landscape): on the one hand, they accelerate disease spread, and on the other hand they slow down the spread of the resistance-breaking genotype. This work contributes to a better understanding of the multiple effects underlying the performance of host diversification methods in agroecology.

PMID:35598221 | DOI:10.1007/s11538-022-01023-5

Asian Pac J Allergy Immunol. 2022 May 22. doi: 10.12932/AP-071121-1267. Online ahead of print.

ABSTRACT

BACKGROUND: Nasal irrigation is an effective component of sino-nasal disease management. Nonetheless, bacterial contamination is worrisome.

OBJECTIVE: To study bacterial colonization incidence using squeeze-bottle nasal irrigation devices, after disinfection with soap or soap-plus-microwave technique, in pediatric acute rhinosinusitis.

METHODS: A randomized, prospective, controlled study was conducted on acute rhinosinusitis children, aged 2-15 years. Each participant was randomized into a soap-cleaning or soap-plus- microwave group. For a two-week period, participants irrigated their nostrils with NSS twice daily and cleaned the bottle after each use. In the end, bottles were sent to a microbiological laboratory for bacterial identification.

RESULTS: The mean 5S Score and satisfaction score gradually improved in both groups with no significant differences between groups. Bacterial identification frequency in the soap group was slightly higher than in the soap-plus-microwave one, without statistical significance. For safety and tolerability, all participants reported 100% adherence to nasal irrigation. The soap-plus-microwave group reported more minor adverse outcomes than the soap-cleaning one. No thermal deformation of irrigation bottles was observed.

CONCLUSIONS: Regular cleaning of nasal irrigation devices is needed to minimize bacterial contamination. Only soap or soap plus microwave disinfection appeared simple and safe for disinfection. Both techniques can equally minimize the rate of bacterial contamination. Although no gross thermal deformation at optimal power and duration, chemical irritants after high power or long microwave durations may be a concern.

PMID:35598187 | DOI:10.12932/AP-071121-1267

J Assoc Physicians India. 2022 May;70(5):11-12.

ABSTRACT

OBJECTIVES: To determine the association of eNOS (T786C and 27bp VNTR) gene polymorphism with the risk of type II diabetes mellitus and diabetic nephropathy in North India.

METHODS: The prospective case control study was conducted over a period of 18 months. A total of 100 patients of Type 2 Diabetes Mellitus (A1: 50 cases without Diabetic nephropathy-DN and 50 cases with DN) aged 18-75 years and 50 healthy adults as control (Group B) were included. The endothelial nitric oxide gene variant (T786C and 27bp VNTR) genotypes and alleles were studied. Odds ratio with 95% CI was calculated for genotype and alleles for the occurrence of diabetes and DN. p value of less than 0.05 was considered as significant.

RESULTS: With Bb as reference(27bp VNTR), the odds ratio for Ab in the three groups (A1,A2,B) was 2.243, 1.545 and 0.746 respectively; and for Aa was 3.043, 3.058 and 1.878 respectively; with TT as reference (T786C), it was 1.573, 1.55 and 1.055 respectively for TC; and for CC it was 2.121, 2.063 and 2.348 respectively. The OR was comparable among the study groups and control for all genotypes and alleles (p>0.05).

CONCLUSION: In conclusion, there was a trend towards higher predilection of DN with aa genotype and a allele in 27 VNTR, CC genotype and C allele of -786T>C polymorphism however it was not found to be statistically significant. Future large sample studies are required to account for the ethnic variation for a clearer association of the genes and their associated risk with Diabetes and its complications.

PMID:35598133

J Assoc Physicians India. 2022 May;70(5):11-12.

ABSTRACT

PURPOSE: It is rationale to predict fluid responsiveness for optimum hemodynamic management. Passive Leg Raising (PLR) causes reversible increase in cardiac output (CO) and changes in end-tidal CO2& pressure (ETCO2 ) can be considered surrogate for CO variations. We aimed to assess the variations in EtCO2 with PLR and fluid challenge (FC) and also compared it with systolic arterial pressure (SAP), mean arterial pressure (MAP), heart rate (HR) and central venous pressure (CVP).

METHODOLOGY: This Prospective study was conducted in the ICU of a tertiary care teaching public hospital. PLR was performed before FC in patients of circulatory failure on mechanical ventilation. ETCO2 and hemodynamics were monitored and compared and correlated after PLR and FC. ROC curve of parameters, based on their Area under the Curve (AUC) was compared. MS Excel, PSPP version 1.0.1 was used for analysis.

RESULTS: Among hundred patients studied, 74 showed ETCO2 change≥ 2 mmHg (&gt;5%) and were fluid responders. Increase in Etco2 after PLR at 1minute and FC at 30 minutes was statistically significant (p=2.73×10-73) so is SAP(p=4.02×10-75) and MAP(p=1.75×10-75). AUC of predictive performance of parameters showed change in ETCO2 (AUC ROC 0.985 [0.938 to 0.999]) had significantly outperformed CVP (AUCROC 0.822 [0.733-0.892]), SAP (AUCROC 0.793 [0.701-0.868]), MAP (AUCROC 0.810 [0.719-0.881]), HR (AUCROC 0.574 [0.471-0.673]). <p>Conclusion: Variations in ETCO2 &gt;5% induced by PLR can predict fluid responsiveness and is a reliable, non-invasive, easy, quick, and reversible method. ETCO2 is better predictor than SAP, MAP, CVP, and HR during PLR and FC. We may recommend PLR-induced changes in ETCO2 to predict fluid responsiveness in mechanically ventilated patients.

PMID:35598132

J Assoc Physicians India. 2022 May;70(5):11-12.

ABSTRACT

BACKGROUND: Many studies found that only hypomagnesemia, but not hypermagnesemia is linked with increased mortality. However, reports of mortality due to magnesium dysregulation in the critical care setting are controversial.

OBJECTIVES: To study serum magnesium levels in critically ill patients on admission in intensive care unit (ICU) and its correlation with patient’s need and duration for ventilator support, duration of ICU stay, incidence of cardiac arrhythmias and mortality Methods: Two hundred forty six critically ill patients admitted in ICU with Acute Physiology and Chronic Health Evaluation (APACHE) II scores&gt;10, were included for this prospective observational study. Serum total magnesium level was measured at the time of admission to ICU. Primary outcome measure was ICU mortality whereas, secondary outcome measures were patient’s need and duration for ventilator support, duration of ICU stay, and incidence of cardiac arrhythmias. Categorical and continuous variables were tested using Chi-square/Fisher’s exact test and analysis of variance respectively. Multivariate logistic regression analysis was carried out to determine association of serum magnesium levels with ICU mortality.

RESULTS: Incidence of ICU mortality was significantly higher in group of patients with hypomagnesemia compared to those with normal magnesium levels. Hypomagnesemia was associated with need and longer duration of ventilator support, longer duration of ICU stay, higher APACHE II score, QTc prolongation, higher incidence of cardiac arrhythmias compared to patients with normal magnesium levels. Hypomagnesemia was an independent and statistically significant determinant of ICU mortality.

CONCLUSIONS: Hypomagnesemia was associated with higher mortality rate, longer duration of ventilator support and ICU stay, and higher APACHE II score in critically ill patients.

PMID:35598126

J Assoc Physicians India. 2022 May;70(5):11-12.

ABSTRACT

AIMS AND OBJECTIVES: Patients with pulmonary thromboembolism (PTE) are commonly admitted to hospital and generally have a prolonged hospital stay in this part of the world. We aimed to determine different clinical and laboratory parameters that are associated with prolonged hospital stay in our set-up and to analyse effectiveness of Pulmonary Embolism Severity Index (PESI) score as a predictor of prolonged hospital stay in patients with PTE.

MATERIALS AND METHODS: It was a hospital based observational prospective study. Confirmed cases of PTE defined as patients with evidence of thrombus on CT pulmonary angiogram (CTPA) were included in this study. Depending on the length of hospital stay, patients were divided into two cohorts: Shorter Hospital stay (less than mean i.e., &lt; 10 Days) and Prolonged Hospital stay (longer than mean i.e., ≥ 10 Days). Logistic regression analysis was done to identify predictors of prolonged hospital stay.

RESULTS: 150 patients were included in the study with 67 patients (44.67%) having shorter hospital stay (&lt;10 days) and 83 patients (55.33%) having prolonged hospital stay (≥10 days). On multivariate regression analysis, parameters that were found to be statistically significant were hypotension at presentation, decreased level of consciousness, pco2 &lt; 30 mmHg, presence of S1Q3T3 pattern on electrocardiogram (ECG) and high risk PESI (class III-V).

CONCLUSION: PESI class can be effectively used to predict prolonged hospital stay in patients with pulmonary embolism. Patients with hypotension at presentation, decreased level of consciousness, pco2 less than 30 mmHg, and S1Q3T3 on ECG are more likely to have prolonged hospital stay in our healthcare setup.

PMID:35598131

Clin Transplant. 2022 May 21:e14716. doi: 10.1111/ctr.14716. Online ahead of print.

ABSTRACT

The Scientific Registry of Transplant Recipients (SRTR) held a consensus conference in 2012 that examined methods used by SRTR for constructing performance metrics and made recommendations on how to improve program-specific reports. That consensus conference provided 25 recommendations categorized as follows: statistical methods, risk adjustment, and outcomes and data. During the subsequent decade, SRTR has implemented most of these recommendations; these are described in this article along with plans for another consensus conference in 2022. With the present article, SRTR aims to create transparency in the field of transplant metrics and guide discussion in the planning of the next consensus conference in 2022. The new conference will revisit the previous topics and have a broader focus to improve the metrics and information that SRTR provides. Readers can provide feedback on topics to be discussed at the next consensus conference as early as possible, by emailing srtr@srtr.org with the subject line “Task 5 Public Comment.” This article is protected by copyright. All rights reserved.

PMID:35598080 | DOI:10.1111/ctr.14716

Med Phys. 2022 May 21. doi: 10.1002/mp.15765. Online ahead of print.

ABSTRACT

BACKGROUND: Fast and accurate multi-organs segmentation from CT scans is essential for radiation treatment planning. Self-attention based deep learning methodologies provide higher accuracies than standard methods but require memory and computationally intensive calculations, which restricts their use to relatively shallow networks.

PURPOSE: Our goal was to develop and test a new computationally fast and memory efficient bi-directional self-attention method called nested block self attention (NBSA), which is applicable to shallow and deep multi-organ segmentation networks.

METHODS: A new multi-organ segmentation method combining a deep multiple resolution residual network with computationally efficient self attention called nested block self attention (MRRN-NBSA) was developed and evaluated to segment 18 different organs from head and neck (HN) and abdomen organs. MRRN-NBSA combines features from multiple image resolutions and feature levels with self-attention to extract organ specific contextual features. Computationally efficiency is achieved by using memory blocks of fixed spatial extent for self-attention calculation combined with bi-directional attention flow. Separate models were trained for HN (n = 238) and abdomen (n = 30) and tested on set aside open-source grand challenge datasets for HN (n = 10) using public domain database of computational anatomy and blinded testing on 20 cases from Beyond the Cranial Vault dataset with overall accuracy provided by the grand challenge website for abdominal organs. Robustness to two-rater segmentations was also evaluated for HN cases using the open-source dataset. Statistical comparison of MRRN-NBSA against Unet, convolutional network based self attention using criss-cross attention (CCA), dual self-attention, and transformer-based (UNETR) methods was done by measuring the differences in the average Dice similarity coefficient (DSC) accuracy for all HN organs using the Kruskall-Wallis test, followed by individual method comparisons using paired, two-sided Wilcoxon-signed rank tests at 95% confidence level with Bonferroni correction used for multiple comparsions.

RESULTS: MRRN-NBSA produced an average high DSC of 0.88 for HN and 0.86 for the abdomen that exceeded current methods. MRRN-NBSA was more accurate than the computationally most efficient CCA (average DSC of 0.845 for HN, 0.727 for abdomen). Kruskal-Wallis test showed significant difference between evaluated methods (p=0.00025). Pair-wise comparisons showed significant differences between MRRN-NBSA than Unet (p=0.0003), CCA (p=0.030), dual (p=0.038), and UNETR methods (p=0.012) after Bonferroni correction. MRRN-NBSA produced less variable segmentations for submandibular glands (0.82 ± 0.06) compared to two raters (0.75 ± 0.31).

CONCLUSIONS: MRRN-NBSA produced more accurate multi-organ segmentations than current methods on two different public datasets. Testing on larger institutional cohorts is required to establish feasibility for clinical use. This article is protected by copyright. All rights reserved.

PMID:35598077 | DOI:10.1002/mp.15765

Ann Neurol. 2022 May 21. doi: 10.1002/ana.26417. Online ahead of print.

ABSTRACT

OBJECTIVE: Evidence on associations of lifestyle factors with Alzheimer’s pathology and cognition are ambiguous, potentially because they rarely addressed interrelationships of factors and sex effects. While considering these aspects, we examined the relationships of lifestyle factors with brain amyloid burden and cognition.

METHODS: We studied 178 cognitively normal individuals (women, 49%; 65.0 [7.6] years) and 54 individuals with mild cognitive impairment (women, 35%; 71.3 [8.3] years) enrolled in a prospective study of volunteers who completed ¹⁸ F-Flutemetamol amyloid positron emission tomography. Using structural equation modeling, we examined associations between latent constructs representing metabolic/vascular risk, physical activity, and cognitive activity with global amyloid burden and cognitive performance. Furthermore, we investigated the influence of sex in this model.

RESULTS: Overall, higher cognitive activity was associated with better cognitive performance and higher physical activity was associated with lower amyloid burden. The latter association was weakened to a non-significant level after excluding multivariate outliers. Examination of the moderating effect of sex in the model revealed an inverse association of metabolic/vascular risk with cognition in men whereas in women metabolic/vascular risk trended towards increased amyloid burden. Furthermore, a significant inverse association between physical activity and amyloid burden was found only in men. Inheritance of an APOE4 allele was associated with higher amyloid burden only in women.

INTERPRETATION: Sex modifies effects of certain lifestyle-related factors on amyloid burden and cognition. Notably, our results suggest that the negative impact of metabolic/vascular risk influences the risk of cognitive decline and Alzheimer’s disease through distinct paths in women and men. This article is protected by copyright. All rights reserved.

PMID:35598071 | DOI:10.1002/ana.26417