Automatic segmentation of skeletal muscles from MR images using modified U-Net and a novel data augmentation approach

Rapid and accurate muscle segmentation is essential for the diagnosis and monitoring of many musculoskeletal diseases. As gold standard, manual annotation suffers from intensive labor and high inter-operator reproducibility errors. In this study, deep learning (DL) based automatic muscle segmentation from MR scans is investigated for post-menopausal women, who normally experience a decline in muscle volume. The performance of four Deep Learning (DL) models was evaluated: U-Net and UNet++ and two modified U-Net networks, which combined feature fusion and attention mechanisms (Feature-Fusion-UNet, FFU, and Attention-Feature-Fusion-UNet, AFFU). The models were tested for automatic segmentation of 16-lower limb muscles from MRI scans of two cohorts of post-menopausal women (11 subjects in PMW-1, 8 subjects in PMW-2; from two different studies so considered independent datasets) and 10 obese post-menopausal women (PMW-OB). Furthermore, a novel data augmentation approach is proposed to enlarge the training dataset. The results were assessed and compared by using the Dice similarity coefficient (DSC), relative volume error (RVE), and Hausdorff distance (HD). The best performance among all four DL models was achieved by AFFU (PMW-1: DSC 0.828 ± 0.079, 1-RVE 0.859 ± 0.122, HD 29.9 mm ± 26.5 mm; PMW-2: DSC 0.833 ± 0.065, 1-RVE 0.873 ± 0.105, HD 25.9 mm ± 27.9 mm; PMW-OB: DSC 0.862 ± 0.048, 1-RVE 0.919 ± 0.076, HD 34.8 mm ± 46.8 mm). Furthermore, the augmentation of data significantly improved the DSC scores of U-Net and AFFU for all 16 tested muscles (between 0.23% and 2.17% (DSC), 1.6%-1.93% (1-RVE), and 9.6%-19.8% (HD) improvement). These findings highlight the feasibility of utilizing DL models for automatic segmentation of muscles in post-menopausal women and indicate that the proposed augmentation method can enhance the performance of models trained on small datasets.

Nutrition interventions for body composition, physical function, cognition in hospitalized older adults: A systematic review of individuals 75 years and older

BACKGROUND

Globally, the oldest old population is expected to triple by 2050. Hospitalization and malnutrition can result in progressive functional decline in older adults. Minimizing the impact of hospitalization on functional status in older adults has the potential to maintain independence, reduce health and social care costs, and maximize years in a healthy state. This study aimed to systematically review the literature to identify nutritional interventions that target physical function, body composition, and cognition in the older population (≥ 75 years).

METHODS

A systematic review was conducted to evaluate the efficacy of nutritional interventions on physical function, body composition, and cognition in adults aged ≥ 75 years or mean age ≥80 years. Searches of PubMed (National Institutes of Health, National Library of Medicine), Scopus (Elsevier), EMBASE (Elsevier), Cumulative Index to Nursing and Allied Health Literature (CINAHL) with Full Text (EBSCOhost), and PsycInfo (EBSCOhost) were conducted. Screening, data extraction, and quality assessment were performed in duplicate and independently (CRD42022355984; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=355984).

RESULTS

Of 8311 citations identified, 2939 duplicates were excluded. From 5372 citations, 189 articles underwent full-text review leaving a total of 12 studies for inclusion. Interventions were food-based, protein-based, carbohydrate-based, personalized, or used parenteral nutrition. Ten studies monitored anthropometric or body composition changes with three showing maintenance or improvements in lean mass, body mass index, triceps skinfold, and mid-upper arm circumference compared with the control group. Six studies monitored physical function but only the largest study found a beneficial effect on activities of daily living. Two of three studies showed the beneficial effects of nutritional intervention on cognition.

CONCLUSION

There are few, high-quality, nutrition-based interventions in older adults ≥75 years. Despite heterogeneity, our findings suggest that large, longer-term (>2 weeks) nutritional interventions have the potential to maintain body composition, physical function, and cognition in adults aged 75 years and older during hospitalization.

Reduced muscle strength (dynapenia) in women with obesity confers a greater risk of falls and fractures in the UK Biobank

OBJECTIVE

This study aimed to determine the independent effects of obesity and dynapenia on falls risk, areal bone mineral density, and fracture risk (lower extremity or all other fractures).

METHODS

A total of 16,147 women (aged 60-82 years) from the UK Biobank were categorized by handgrip strength (HGS; dynapenia status: HGS ≤ 21 kg) and body weight (BMI: normal weight, overweight, or obesity). Multiple logistic regression models examined the association among dynapenia and obesity and self-reported falls (previous 12 months), lower extremity fractures, and all other fractures (previous 5 years).

RESULTS

A total of 3793/16,147 women fell, and 1413/15,570 (9.1%) eligible women experienced fall-related fractures. Obesity (odds ratio [OR] 1.25; 95% CI: 1.12-1.38) and dynapenia (OR 0.87; 95% CI: 0.77-0.98) were both independently associated with greater lower extremity fracture risk, independently of areal bone mineral density. However, considering all other fracture sites, obesity conferred protection (OR 0.77; 95% CI: 0.61-0.96), except in those with low HGS, who had an equivalent fracture risk to those with normal weight (OR 1.06; 95% CI: 0.82-1.38).

CONCLUSIONS

Dynapenia further increases the increased risk of leg and ankle fractures in obesity and counteracts the protective effects of obesity on fracture risk at all other sites (wrist, arm, hip, spine, other bones).

Dynapenic Abdominal Obesity as a Risk Factor for Falls

BACKGROUND

Obesity and low muscle strength (dynapenia) are independently associated with greater falls risk. It remains unclear whether dynapenia and obesity have an additive effect on falls risk, greater than either phenotype alone.

OBJECTIVES

To determine whether a combination of abdominal obesity with dynapenia, dynapenic abdominal obesity (DAO), confers a greater risk of falls than either obesity or dynapenia alone in both men and women.

DESIGN

An observational cohort study was conducted.

SETTING AND PARTICIPANTS

Data from English adults (n=4239, 60-87 years) who took part in the English Longitudinal Study of Ageing were included.

MEASUREMENTS

Dynapenia, was defined as hand-grip strength <20kg (female), <30kg (male). Abdominal obesity was defined as waist circumference >88cm (female), >102cm (male). Data on falls and fall-related injuries over a 2-year follow-up were collected. Multiple logistic regression analyses were performed adjusting for age and sex, with results expressed as odds ratios (OR) and areas under the receiver operating characteristic curve (AUC).

RESULTS

Falls occurred in 1049 participants, with 284 reporting a related injury during follow-up. DAO was associated with greater OR of falls in men (OR 2.1, 95% Confidence Intervals (CI) 1.3-3.2). Dynapenia rather than obesity was associated with falls in women, with greatest OR observed in those with low hand-grip strength (OR 1.4, 95% CI 1.1-1.7). Individual discrimination was low for measures of obesity or dynapenia either alone or in combination (AUC 0.51-0.58). There was no relationship between fall-related injuries and obesity or dynapenia.

CONCLUSION

Our findings suggest a synergistic effect of obesity with dynapenia on falls risk in men but not women.

MicroRNAs in obesity, sarcopenia, and commonalities for sarcopenic obesity: a systematic review

Sarcopenic obesity is a distinct condition of sarcopenia in the context of obesity, with the cumulative health risks of both phenotypes. Differential expression of microRNAs (miRNAs) has been reported separately in people with obesity and sarcopenia and may play a role in the pathogenesis of sarcopenic obesity. However, this has not been explored to date. This study aimed to identify differentially expressed miRNAs reported in serum, plasma, and skeletal muscle of people with obesity and sarcopenia and whether there are any commonalities between these conditions. We performed a systematic review on Embase and MEDLINE (PROSPERO, CRD42020224486) for differentially expressed miRNAs (fold change >1.5 or P-value <0.05) in (i) sarcopenia or frailty and (ii) obesity or metabolic syndrome. The functions and targets of miRNAs commonly changed in both conditions, in the same direction, were searched using PubMed. Following deduplication, 247 obesity and 42 sarcopenia studies were identified for full-text screening. Screening identified 36 obesity and 6 sarcopenia studies for final inclusion. A total of 351 miRNAs were identified in obesity and 157 in sarcopenia. Fifty-five miRNAs were identified in both obesity and sarcopenia-by sample type, 48 were found in plasma and one each in serum and skeletal muscle. Twenty-four miRNAs were identified from 10 of the included studies as commonly changed in the same direction (22 in plasma and one each in serum and skeletal muscle) in obesity and sarcopenia. The majority of miRNA-validated targets identified in the literature search were members of the phosphoinositide 3-kinase/protein kinase B and transforming growth factor-β signalling pathways. The most common targets identified were insulin-like growth factor 1 (miR-424-5p, miR-483-3p, and miR-18b-5p) and members of the SMAD family (miR-483-3p, miR-92a-3p, and miR-424-5p). The majority of commonly changed miRNAs were involved in protein homeostasis, mitochondrial dynamics, determination of muscle fibre type, insulin resistance, and adipogenesis. Twenty-four miRNAs were identified as commonly dysregulated in obesity and sarcopenia with functions and targets implicated in the pathogenesis of sarcopenic obesity. Given the adverse health outcomes associated with sarcopenic obesity, understanding the pathogenesis underlying this phenotype has the potential to lead to effective screening, monitoring, or treatment strategies. Further research is now required to confirm whether these miRNAs are differentially expressed in older adults with sarcopenic obesity.

Do-it-yourself closed-loop systems for people living with type 1 diabetes

Growing numbers of people with type 1 diabetes are using do-it-yourself closed-loop systems. While these technologies are not approved by regulatory bodies and are not commercially available, users of the technology report improvements in HbA_1c and time in range, and reduced burden of diabetes. Healthcare professionals have expressed their concern that legal or regulatory body actions could ensue if they support people who choose to use do-it-yourself closed-loop systems. Diabetes UK's position statements make recommendations that aim to provide guidance for both people with diabetes and healthcare professionals, based on the current professional and legal situation. They respect an individual's right to make their own informed decisions about their diabetes management, and recommend that they should have access to the technology they need for optimal diabetes management. People who wish to use do-it-yourself closed-loop systems should continue to receive support and care from their diabetes team. Healthcare professionals should engage in conversations around do-it-yourself closed-loop systems, if the issue is raised, to allow a balanced discussion of risks and benefits. However, healthcare professionals cannot recommend the use of do-it-yourself closed-loop systems because of a lack of regulatory body approval and robust, published research to support safety or effectiveness. People using this technology should be aware that they do so at their own risk. This position statement recognizes that the development of diabetes technology is a rapidly changing environment, and guidance around do-it-yourself systems is required from professional and regulatory bodies.

Parents' perspectives on the value of assistance dogs for children with autism spectrum disorder: a cross-sectional study

OBJECTIVE

While there is an emerging literature on the usefulness of assistance dogs for children with autism spectrum disorder (ASD), there is a dearth of quantitative data on the value of assistance dog interventions for the family unit and family functioning. Using previously validated scales and scales developed specifically for this study, we measured parents'/guardians' perceptions of how having an assistance dog affects: (1) child safety from environmental dangers, (2) public reception of ASD and (3) levels of caregiver strain and sense of competence. We also obtained open-ended response data from parents/guardians on benefits and constraints of having an assistance dog.

SETTING

This study was based in the primary care setting, within the context of a specific accredited assistance dog centre in Ireland.

PARTICIPANTS

A total of 134 parents/guardians with an assistance dog, and 87 parents of children on the waiting list were surveyed.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome measures were scores on environmental hazards and public reception scales. The secondary outcome measures were scores on caregiver strain and competence scales.

RESULTS

Parents/guardians of children who have ASD and an assistance dog rate their child as significantly safer from environmental dangers (p<0.001), perceive that the public act more respectfully and responsibly towards their child (p<0.001) and feel more competent about managing their child (p=0.023) compared with parents on the waiting list. There was a concentration of positive feeling towards assistance dog interventions with particular focus on safety and comfort for children, and a sense of freedom from family restrictions associated with ASD. The amount of dedication and commitment required to care for a dog were viewed as the primary constraints.

CONCLUSIONS

Our findings indicate that parents perceive that assistance dog interventions can be a valuable intervention for families with children who have ASD.

A novel method for controlling multicolored Asian lady beetle (Coleoptera: Coccinellidae) in vineyards

The introduced biological control agent Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae) has attained pest status in North America as its presence in vineyards during harvest may compromise the quality of the resulting wine. Control of H. axyridis in vineyards is difficult as their populations may fluctuate daily, and there are few products registered to control this pest. Sulfur dioxide, in the form of potassium metabisulfite (KMS), is commonly used in wine as both an antimicrobial and an antioxidant. In this study, the effectiveness of KMS as a repellent against H. axyridis was measured. In a Y-tube olfactometer, H. axyridis spent significantly less time in the treatment arm (KMS 2.5, 5, and 10 g/liter) than in the control arm during a 10-min period. When sprayed in a vineyard, KMS significantly reduced the number of H. axyridis on grape vines. KMS is an effective repellent against H. axyridis and may be suitable for use in vineyards to control this pest. KMS (5 g/liter) applied to Riesling grapes at 2 wk, 1 wk, 3 d, or 1 d before harvest did not affect free sulfur dioxide in either freshly processed or settled juice. This study lays the foundation for the development of a pest management strategy incorporating repellents for H. axyridis in vineyards.

An evaluation of the Nashville REACH 2010 community health screening strategy

Community-based screening is 1 of 4 strategies selected by the Nashville REACH 2010 project for reducing disparities in heart disease and diabetes among African Americans in North Nashville, Tenn. We evaluated our screening efforts by asking 4 questions: (1) Are the screening participants representative of the target population? (2) How often were screening participants with possible undiagnosed hypertension, high cholesterol, and diabetes identified? (3) How often were screening participants with an elevated risk for developing hypertension, high cholesterol, and diabetes identified? and (4) How often did we identify screening participants with known hypertension, high cholesterol, and diabetes whose disease management was suboptimal? Results from 1757 persons screened were compared to telephone surveys from 16,199 Nashville residents. Those screened were younger and healthier than the target population. Rates of potentially undiagnosed cases among African Americans were 0.8% for diabetes, 17.4% for hypertension, and 32.7% for high cholesterol. High-risk individuals were identified 13.1% of the time for diabetes, 45.3% of the time for hypertension, and 21.3% of the time for total cholesterol. Rates of poorly controlled known disease were 23.5% for diabetes, 39.0% for hypertension, and 58.2% for total cholesterol. Although we reached a younger and healthier group than the community population, community-based screenings identified many people with potential health risks. We present a model of how to organize and implement successful community-based screening.

Leukocystatin, a new Class II cystatin expressed selectively by hematopoietic cells

We describe a new cystatin in both mice and humans, which we termed leukocystatin. This protein has all the features of a Class II secreted inhibitory cystatin but contains lysine residues in the normally hydrophobic binding regions. As determined by cDNA library Southern blots, this cystatin is expressed selectively in hematopoietic cells, although fine details of the distribution among these cell types differ between the human and mouse mRNAs. In addition, we have determined the genomic organization of mouse leukocystatin, and we found that in contrast to most cystatins, the leukocystatin gene contains three introns. The recombinant proteins corresponding to these cystatins were expressed in Escherichia coli as N-terminal glutathione S-transferase or FLAGTM fusions, and studies showed that they inhibited papain and cathepsin L but with affinities lower than other cystatins. The unique features of leukocystatin suggests that this cystatin plays a role in immune regulation through inhibition of a unique target in the hematopoietic system.

Assessment of body fat and lean in the elderly by measuring body carbon and oxygen: validation against hydrodensitometry

Based on the observation that the carbon-to-oxygen ratio (C/O) in tissue is a measure of fat content, we developed a model which correlates C/O to percent body fat. Carbon and oxygen mass and their ratio are measured in vivo by fast neutron inelastic scattering, using a miniature D-T neutron generator, at a radiation exposure of less than 0.06 mSv. We tested the validity of this model against hydrodensitometry with 19 healthy adult volunteers. The method was found to be accurate and insensitive to assumptions about the composition of lean tissue and, therefore, appropriate for studying the elderly and patients with catabolic conditions.

Age-related changes in a spontaneously reassociating fraction of mouse DNA

Rapidly reassociating fractions have been isolated from mouse brain and liver nuclear DNA by hydroxyapatite fractionation of sonicated and denatured preparations incubated at a Cot of 1. When prepared by thermal denaturation, a subfraction of this DNA, representing approximately 0.6% of liver and brain DNA, has been shown to spontaneously reassociate at Cot 10(-5). This fraction increases 3-fold in DNA from old animals. When prepared by alkaline denaturation or treated with pronase, no age-related increase is observed, suggesting the presence of an alkali-labile stabilizing protein component in DNA from old cells. A portion of this fraction is observed by electron microscopy under denaturing conditions to consists of looped hairpin structures in DNA from old, but not from yound or mature animals. These structures are not seen after pronase treatment.