Recent advances in predicting and modeling protein-protein interactions.

Protein-protein interactions (PPIs) drive biological processes, and disruption of PPIs can cause disease. With recent breakthroughs in structure prediction and a deluge of genomic sequence data, computational methods to predict PPIs and model spatial structures of protein complexes are now approaching the accuracy of experimental approaches for permanent interactions and show promise for elucidating transient interactions. As we describe here, the key to this success is rich evolutionary information deciphered from thousands of homologous sequences that coevolve in interacting partners. This covariation signal, revealed by sophisticated statistical and machine learning (ML) algorithms, predicts physiological interactions. Accurate artificial intelligence (AI)-based modeling of protein structures promises to provide accurate 3D models of PPIs at a proteome-wide scale.

Sobetirome rescues α-synuclein-mediated demyelination in an in vitro model of multiple system atrophy.

Multiple system atrophy (MSA) is a rare and rapidly progressive atypical parkinsonian disorder characterized by oligodendroglial cytoplasmic inclusions containing α-synuclein (α-syn), demyelination, inflammation and neuronal loss. To date, no disease-modifying therapy is available. Targeting α-syn-driven oligodendroglial dysfunction and demyelination presents a potential therapeutic approach for restricting axonal dysfunction, neuronal loss and disease progression. The present study investigated the promyelinogenic potential of sobetirome, a blood-brain barrier permeable and central nervous system selective thyromimetic in the context of an in vitro MSA model. Oligodendrocyte precursor cells (OPCs) were obtained from transgenic mice overexpressing human α-syn specifically in oligodendrocytes (MBP29 mouse line), a well-described MSA model, and non-transgenic littermates. mRNA and protein expression analyses revealed a substantial rescue effect of sobetirome on myelin-specific proteins in control and α-syn overexpressing oligodendrocytes. Furthermore, myelination analysis using nanofibres confirmed that sobetirome increases both the length and number of myelinated segments per oligodendrocyte in primary murine α-syn overexpressing oligodendrocytes and their respective control. These results suggest that sobetirome may be a promising thyromimetic compound targeting an important neuropathological hallmark of MSA.

In vivo cerebral metabolic and dopaminergic characteristics in multiple system atrophy with orthostatic hypotension.

PURPOSE: Multiple system atrophy (MSA) is a rare neurodegenerative disease, often presented with orthostatic hypotension (OH), which is a disabling symptom but has not been very explored. Here, we investigated MSA patients with OH by using positron emission tomography (PET) with 18F-fluorodeoxyglucose (18F-FDG) and 11C-N-2-carbomethoxy-3-(4-fluorophenyl)-tropane (11C-CFT) for in vivo evaluation of the glucose metabolism and dopaminergic function of the brain. METHODS: Totally, 51 patients with MSA and 20 healthy controls (HC) who underwent 18F-FDG PET/CT were retrospectively enrolled, among which 24 patients also underwent 11C-CFT PET/CT. All patients were divided into MSA-OH(+) and MSA-OH(-) groups. Then, statistical parametric mapping (SPM) method was used to reveal the regional metabolic and dopaminergic characteristics of MSA-OH(+) compared with MSA-OH(-). Moreover, the metabolic networks of MSA-OH(+), MSA-OH(-) and HC groups were also constructed and analyzed based on graph theory to find possible network-level changes in MSA patients with OH. RESULTS: The SPM results showed significant hypometabolism in the pons and right cerebellar tonsil, as well as hypermetabolism in the left parahippocampal gyrus and left superior temporal gyrus in MSA-OH(+) compared with MSA-OH(-). A reduced 11C-CFT uptake in the left caudate was also shown in MSA-OH(+) compared with MSA-OH(-). In the network analysis, significantly reduced local efficiency and clustering coefficient were shown in MSA-OH(+) compared with HC, and decreased nodal centrality in the frontal gyrus was found in MSA-OH(+) compared with MSA-OH(-). CONCLUSION: In this study, the changes in glucose metabolism in the pons, right cerebellar tonsil, left parahippocampal gyrus and left superior temporal gyrus were found closely related to OH in MSA patients. And the decreased presynaptic dopaminergic function in the left caudate may contribute to OH in MSA. Taken together, this study provided in vivo pathophysiologic information on MSA with OH from neuroimaging approach, which is essential for a better understanding of MSA with OH.

Development of Company-Specific Emission Factors with Confidence Intervals for Natural Gas Customer Meters in Southern California.

Methane is both a significant and short-lived greenhouse gas compared to CO2, and reducing methane emissions from natural gas distribution systems may offer cost-effective reduction opportunities. We report substantial new direct leak rate measurements from customer meter set assemblies (MSAs) in Southern California. In a novel way, emission factors are defined in terms of aboveground Hazardous and Nonhazardous leak categories, which take direct advantage of readily available industry leak data. We also studied leaks that were not detected as part of normal leak survey procedures. As a result, this yields company-specific emission factors that can be used to track progress in reducing methane emissions. This approach also has the advantage of explicitly accounting for the skewed or fat-tail distribution of leak rates by treating high flow rate MSA leaks separately from low flow rate MSA leaks. The Southern California Gas (SoCalGas) methane emission factors, based on 485 leak rate measurements by direct enclosure, were 4.55 (95% confidence interval: 2.32 to 7.14) kg/day for Hazardous leaks, 0.149 (0.119 to 0.183) kg/day for Nonhazardous leaks, and 0.0039 (0.0003 to 0.0198) kg/day for Non-Detected leaks. The percentage of surveyed meters with nondetected leaks was 29.1% (24.3 to 34.6%). Based on a robust Monte Carlo analysis, total leak emissions from MSAs for the SoCalGas system were reduced by 35% based on data from 2015 to 2022. These reductions were attributed to surveying a larger number of MSAs and accelerated leak repair rates. In traditional population-based emission inventories, an individual emission factor for a given asset category is multiplied by the total population of MSAs within the category. This approach simply cannot capture the reduction in leak numbers and methane emissions resulting from leak mitigation and prevention programs.

Short term safety of magnetic sphincter augmentation vs minimally invasive fundoplication: an ACS-NSQIP analysis.

PURPOSE: Magnetic Sphincter Augmentation (MSA) is an FDA-approved anti-reflux procedure with comparable outcomes to fundoplication. However, most data regarding its use are limited to single or small multicenter studies which may limit the generalizability of its efficacy. The purpose of this study is to evaluate the outcomes of patients undergoing MSA vs fundoplication in a national database. MATERIALS AND METHODS: The 2017-2020 American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) Registry was utilized to evaluate patients undergoing MSA or fundoplication. Patients requiring Collis gastroplasty, paraesophageal hernia repair, and emergency cases, were excluded. Patient outcomes included overall complication rates, readmissions, reoperations, and mortality. RESULTS: A total of 7,882 patients underwent MSA (n = 597) or fundoplication (n = 7285). MSA patients were younger (51 vs 57, p < 0.001), and more often male (49.6 vs 34.3%, p < 0.001). While patients undergoing MSA experienced similar rates of reoperation (1.0 vs 2.0%, p = 0.095), they experienced fewer readmissions (2.2 vs 4.7%, p = 0.005), complications (0.6 vs 4.0%, p < 0.001), shorter mean (SD) hospital length of stay(days) (0.4 ± 4.3 vs 1.8 ± 4.6, p < 0.001) and operative time(min) (80.8 ± 36.1 vs 118.7 ± 63.7, p < 0.001). Mortality was similar between groups (0 vs 0.3%, p = 0.175). On multivariable analysis, MSA was independently associated with reduced postoperative complications (OR 0.23, CI 0.08 to 0.61, p = 0.002), readmissions (OR 0.53, CI 0.30 to 0.94, p = 0.02), operative time (RC - 36.56, CI - 41.62 to - 31.49. p < 0.001) and length of stay (RC - 1.22, CI - 1.61 to - 0.84 p < 0.001). CONCLUSION: In this national database study, compared to fundoplication MSA was associated with reduced postoperative complications, fewer readmissions, and shorter operative time and hospital length of stay. While randomized trials are lacking between MSA and fundoplication, both institutional and national database studies continue to support the use of MSA as a safe anti-reflux operation.

Rapidly progressive multiple system atrophy in a patient carrying LRRK2 G2019S mutation.

BACKGROUND: Multiple system atrophy (MSA) is considered a primarily sporadic neurodegenerative disease, but the role of genetic is poorly understood. CASE: We present a female patient of Moroccan origin who developed a rapidly progressive non-levodopa responsive parkinsonism, gait and balance problems, and dysautonomia including severe bulbar symptoms. She was diagnosed with MSA Parkinsonian-type (MSA-P) and suddenly died at night at 58 years of age. Reduced striatal DAT-SPECT, putaminal hyperintensity on T2-MRI, and hypometabolism with FDG-PET were present. Genetic testing documented a G2019S mutation in the LRRK2 gene. A skin biopsy was obtained and used to perform alpha-synuclein RT-QuIC, which was negative, and immunohistochemical analysis, which demonstrated abnormal alpha-synuclein deposits in cutaneous nerves. Elevated blood neurofilament light chain levels were also documented. CONCLUSIONS: LRRK2 mutations are the most common cause of monogenic Parkinson's disease (PD) and G2019S is the most frequent variant. Our patient presented with biological, clinical, and radiological features of MSA, but genetic testing revealed a G2019S LRRK2 mutation, which has been previously reported only in one other case of pathologically proven MSA but with mild progression. In our patient, post-mortem confirmation could not be performed, but RT-QuIC and immunohistochemical findings on skin biopsy support the diagnosis of MSA. G2019S LRRK2 may be linked to an increased risk of MSA. Cases of atypical parkinsonism with rapid disease course should be screened for PD-related genes especially in populations with a high prevalence of mutations in known genes.

A novel Skin lesion prediction and classification technique: ViT-GradCAM.

BACKGROUND: Skin cancer is one of the highly occurring diseases in human life. Early detection and treatment are the prime and necessary points to reduce the malignancy of infections. Deep learning techniques are supplementary tools to assist clinical experts in detecting and localizing skin lesions. Vision transformers (ViT) based on image segmentation classification using multiple classes provide fairly accurate detection and are gaining more popularity due to legitimate multiclass prediction capabilities. MATERIALS AND METHODS: In this research, we propose a new ViT Gradient-Weighted Class Activation Mapping (GradCAM) based architecture named ViT-GradCAM for detecting and classifying skin lesions by spreading ratio on the lesion's surface area. The proposed system is trained and validated using a HAM 10000 dataset by studying seven skin lesions. The database comprises 10 015 dermatoscopic images of varied sizes. The data preprocessing and data augmentation techniques are applied to overcome the class imbalance issues and improve the model's performance. RESULT: The proposed algorithm is based on ViT models that classify the dermatoscopic images into seven classes with an accuracy of 97.28%, precision of 98.51, recall of 95.2%, and an F1 score of 94.6, respectively. The proposed ViT-GradCAM obtains better and more accurate detection and classification than other state-of-the-art deep learning-based skin lesion detection models. The architecture of ViT-GradCAM is extensively visualized to highlight the actual pixels in essential regions associated with skin-specific pathologies. CONCLUSION: This research proposes an alternate solution to overcome the challenges of detecting and classifying skin lesions using ViTs and GradCAM, which play a significant role in detecting and classifying skin lesions accurately rather than relying solely on deep learning models.

Immune cell profiles of idiopathic inflammatory myopathy patients expressed anti-aminoacyl tRNA synthetase or anti-melanoma differentiation-associated gene 5 autoantibodies.

BACKGROUND: Patients with idiopathic inflammatory myopathy (IIM) often express a different type of myositis-specific autoantibodies (MSAs), each associated with different clinical symptoms. Understanding the immunopathogenesis of various IIM subgroups can help improve the diagnosis and prognosis of IIM patients with different MSAs. However, the immune cell profiles of these IIM patients with anti-aminoacyl tRNA synthetase (ARS) or anti-melanoma differentiation-associated gene 5 (MDA5) autoantibodies remain unclear. We focused on the immune cell profiles of IIM patients with anti-ARS or anti-MDA5 autoantibodies. RESULTS: The peripheral blood from IIM patients with anti-MDA5 autoantibody (MDA5 + group, n = 24) or one of the anti-ARS autoantibodies (ARS + group, n = 40) autoantibodies, and healthy controls (HC group, n = 60) were collected and examined. We found that IIM patients had a lower CD3 T cell population compared to the HC group. IIM patients showed a significantly lower TN cell population and a higher TEMRA cell population. Higher Th17 and Treg cell populations were found in these IIM patients than in the HC group. In these IIM patients, the MDA5 + group exhibited the higher percentages of Th17 and Treg cells than the ARS + group. It is noteworthy that the percentage of Th1 cells in the survival subgroup was higher than in the death subgroup in IIM patients with ARS + or MDA5 + . Furthermore, in the MDA5 + group, the percentage of Treg cells was higher in the survival subgroup compared to the death subgroup. CONCLUSIONS: Our study demonstrated that elevated Th1 may be a good prognostic indicator in IIM patients with ARS + or MDA5 + . Elevated Treg may also help predict a good prognosis in MDA5 + IIM patients. However, more large-scale studies and clinical samples are needed to verify the significance of Th1 and Treg cell subsets in clinical outcomes for these IIM patients with ARS + or MDA5 + . These data may help design a therapeutic approach that specifically targets the pathogenic immune molecular responsible for autoimmune attacks in IIM.

Low-dose rituximab is efficacious in refractory idiopathic inflammatory myopathies.

OBJECTIVES: Rituximab (RTX) use early in the course of refractory idiopathic inflammatory myopathy (IIM) is not well studied. This study sought to determine the short-term efficacy of RTX in a registry-based cohort of refractory IIM. METHODS: Registry-based observational data about IIM patients receiving RTX between 2018 and 2021 were included. Total improvement score was calculated from the core set measures as per International Myositis Assessment and Clinical Studies group (IMACS) at baseline, 6 months and 12 months of follow-up. RESULTS: Forty-two patients (F:M, 29:13), with a mean (s.d.) age of 39.5 (11.5) years were studied. Majority of patients received RTX for refractory myositis, after a median (interquartile range) duration of 8 (4,18) months. Twenty-eight received RTX at a dosage of 1 g × two doses, while 14 received 500 mg × two doses with an interval of 15 days. At 6 months and 12 months post-RTX, the improvement was recorded in manual muscle testing (MMT-8) scores, physician global assessment (PGA), patient global assessment (PtGA) and median steroid dosage as compared with the baseline (P < 0.01 for all). A mean (s.d.) improvement of 44.5 (16) and 48.7 (19.2) in total improvement score was recorded at 6 and 12 months, respectively. The change in MMT-8, PGA and PtGA scores from baseline between the two dosage regimens of RTX were comparable at 6 and 12 months. Severe lower respiratory tract infections requiring hospitalization occurred in three patients of the cohort. CONCLUSION: RTX improved IMACS core set measures and had steroid sparing efficacy at 6 and 12 months in patients with IIM in this registry-based study. Rituximab as an induction regimen of two doses of 500 mg can be as efficacious as 1 g at 6 months and 12 months of follow-up.

Ataxia in a Movement Disorders Outpatient Clinic: a Single-Center Experience in Turkey.

The etiology may not be determined in patients with ataxia despite detailed evaluations. The aim of this study was to investigate the clinical and laboratory characteristics of a large cohort of patients with adult-onset ataxia of different etiologies, particularly, undetermined etiologies despite extensive clinical, genetic, laboratory, electrophysiological, and imaging investigations. The medical records of all patients diagnosed with ataxia of subacute-chronic onset between January 2011 and March 2021 were reviewed retrospectively. The records of patients with symptom onset after 16 years of age were included in the study. In all patients, clinical and demographic findings were noted. Etiologies were classified as acquired, hereditary, degenerative (multiple system atrophy-cerebellar, MSA-C), functional, and undetermined. During the study period, we determined 74 patients with ataxia and 59 (35 males) patients met the study criteria. The age range was 22-87 years. The etiologies were hereditary (n = 19), acquired (n = 14), MSA-C (n = 9), functional (n = 2), and undetermined (n = 15). The patients with hereditary etiologies and undetermined causes were significantly younger at admission and at symptom onset (p = 0.001 and p = 0.000). There was a significant delay until diagnosis in patients with hereditary etiologies compared to other etiologies. In acquired etiologies, axial findings (71.4%) were more prominent whereas extremity and axial findings were more common in patients with hereditary etiologies (83.3%, p = 0.030). There were systemic and radiological indicators such as hearing loss, juvenile cataract, or dentate hyperintensity in certain disorders. Hereditary etiologies are as common as acquired or degenerative etiologies in adults. However, they have an earlier onset and delayed diagnosis. Therefore, we should recognize the extracerebellar neurological, systemic, and neuroimaging findings.

Toward More Accessible Fully Automated 3D Volumetric MRI Decision Trees for the Differential Diagnosis of Multiple System Atrophy, Related Disorders, and Age-Matched Healthy Subjects.

Differentiating multiple system atrophy (MSA) from related neurodegenerative movement disorders (NMD) is challenging. MRI is widely available and automated decision-tree analysis is simple, transparent, and resistant to overfitting. Using a retrospective cohort of heterogeneous clinical MRIs broadly sourced from a tertiary hospital system, we aimed to develop readily translatable and fully automated volumetric diagnostic decision-trees to facilitate early and accurate differential diagnosis of NMDs. 3DT1 MRI from 171 NMD patients (72 MSA, 49 PSP, 50 PD) and 171 matched healthy subjects were automatically segmented using Freesurfer6.0 with brainstem module. Decision trees employing substructure volumes and a novel volumetric pons-to-midbrain ratio (3D-PMR) were produced and tenfold cross-validation performed. The optimal tree separating NMD from healthy subjects selected cerebellar white matter, thalamus, putamen, striatum, and midbrain volumes as nodes. Its sensitivity was 84%, specificity 94%, accuracy 84%, and kappa 0.69 in cross-validation. The optimal tree restricted to NMD patients selected 3D-PMR, thalamus, superior cerebellar peduncle (SCP), midbrain, pons, and putamen as nodes. It yielded sensitivities/specificities of 94/84% for MSA, 72/96% for PSP, and 73/92% PD, with 79% accuracy and 0.62 kappa. There was correct classification of 16/17 MSA, 5/8 PSP, 6/8 PD autopsy-confirmed patients, and 6/8 MRIs that preceded motor symptom onset. Fully automated decision trees utilizing volumetric MRI data distinguished NMD patients from healthy subjects and MSA from other NMDs with promising accuracy, including autopsy-confirmed and pre-symptomatic subsets. Our open-source methodology is well-suited for widespread clinical translation. Assessment in even more heterogeneous retrospective and prospective cohorts is indicated.

Significance of clinical symptoms and red flags in early differential diagnosis of Parkinson's disease and atypical Parkinsonian syndromes.

The clinical presentation of Parkinson's disease and atypical Parkinsonian syndromes is often heterogeneous. Additional diagnostic procedures including brain imaging and biomarker analyses can help to appreciate the various syndromes, but a precise clinical evaluation and differentiation is always necessary. To better assess the relevance of distinct clinical symptoms that arose within 1 year of disease manifestation and evaluate their indicative potential for an atypical Parkinsonian syndrome, we conducted a modified Delphi panel with seven movement disorder specialists. Five different topics with several clinical symptom items were discussed and consensus criteria were tested. This resulted in distinct symptom patterns for each atypical Parkinsonian syndrome showing the multitude of clinical involvement in each neurodegenerative disease. Strongly discriminating clinical signs were few and levels of indication were variable. A prospective validation of the assessments made is needed. This demonstrates that both clinical evaluation and elaborate additional diagnostic procedures are needed to achieve a high diagnostic standard.

Phenotypic and molecular genetics study of Geotrichum candidumLink (1809) and Geotrichum silvicola Pimenta (2005) cultivated on mitis salivarius agar.

BACKGROUND: Geotrichum is a genus of fungi found in different habitats throughout the world. Although Geotrichum and its related species have been extensively reclassified and taxonomically revised, it is still the target for many researches. METHODS AND RESULTS: In this study, phenotypic and molecular genetics comparisons were performed between Geotrichum candidum and Geotrichum silvicola. Mitis Salivarius Agar was used as the growing medium for the phenotypic comparison study, which was carried out at two temperatures (20-25 and 37 °C). For genotypic comparison, we compared the 18 S, ITS, and 28 S sequences of universal DNA barcode regions of both species. Important findings on the new culture media for fungal isolation were revealed by the results. The phenotypic variation between the two species' colonies, including their shapes, sizes, textures and growth rates, were strikingly different. DNA sequences of both species showed that pairwise identities of the species were 99.9% for 18 S, 100% for ITS and 99.6% for 28 S regions. CONCLUSIONS: Contrary to what is commonly seen, the results showed that 18 S, ITS and 28 S failed to discriminate the species. The first investigation into the performance of Mitis Salivarius Agar as a fungus culture medium is reported in this work, and proved its efficiency. Additionally, this is the first study to compare G. candidum with G. silvicola by means of both phenotypic and genotypic analysis.

Neurofilament light levels predict clinical progression and death in multiple system atrophy.

Disease-modifying treatments are currently being trialled in multiple system atrophy. Approaches based solely on clinical measures are challenged by heterogeneity of phenotype and pathogenic complexity. Neurofilament light chain protein has been explored as a reliable biomarker in several neurodegenerative disorders but data on multiple system atrophy have been limited. Therefore, neurofilament light chain is not yet routinely used as an outcome measure in multiple system atrophy. We aimed to comprehensively investigate the role and dynamics of neurofilament light chain in multiple system atrophy combined with cross-sectional and longitudinal clinical and imaging scales and for subject trial selection. In this cohort study, we recruited cross-sectional and longitudinal cases in a multicentre European set-up. Plasma and CSF neurofilament light chain concentrations were measured at baseline from 212 multiple system atrophy cases, annually for a mean period of 2 years in 44 multiple system atrophy patients in conjunction with clinical, neuropsychological and MRI brain assessments. Baseline neurofilament light chain characteristics were compared between groups. Cox regression was used to assess survival; receiver operating characteristic analysis to assess the ability of neurofilament light chain to distinguish between multiple system atrophy patients and healthy controls. Multivariate linear mixed-effects models were used to analyse longitudinal neurofilament light chain changes and correlated with clinical and imaging parameters. Polynomial models were used to determine the differential trajectories of neurofilament light chain in multiple system atrophy. We estimated sample sizes for trials aiming to decrease neurofilament light chain levels. We show that in multiple system atrophy, baseline plasma neurofilament light chain levels were better predictors of clinical progression, survival and degree of brain atrophy than the neurofilament light chain rate of change. Comparative analysis of multiple system atrophy progression over the course of disease, using plasma neurofilament light chain and clinical rating scales, indicated that neurofilament light chain levels rise as the motor symptoms progress, followed by deceleration in advanced stages. Sample size prediction suggested that significantly lower trial participant numbers would be needed to demonstrate treatment effects when incorporating plasma neurofilament light chain values into multiple system atrophy clinical trials in comparison to clinical measures alone. In conclusion, neurofilament light chain correlates with clinical disease severity, progression and prognosis in multiple system atrophy. Combined with clinical and imaging analysis, neurofilament light chain can inform patient stratification and serve as a reliable biomarker of treatment response in future multiple system atrophy trials of putative disease-modifying agents.

6-MSA, a secondary metabolite distribution hub with multiple fungal destinations.

6-methylsalicylic acid (6-MSA) is a small, simple polyketide produced by a broad spectrum of fungal species. Since fungi obtained the ability to synthesize 6-MSA from bacteria through a horizontal gene transfer event, it has developed into a multipurpose metabolic hub from where numerous complex compounds are produced. The most relevant metabolite from a human perspective is the small lactone patulin as it is one of the most potent mycotoxins. Other important end products derived from 6-MSA include the small quinone epoxide terreic acid and the prenylated yanuthones. The most advanced modification of 6-MSA is observed in the aculin biosynthetic pathway, which is mediated by a non-ribosomal peptide synthase and a terpene cyclase. In this short review, we summarize for the first time all the possible pathways that takes their onset from 6-MSA and provide a synopsis of the responsible gene clusters and derive the resulting biosynthetic pathways.

Multiple System Atrophy Caregivers' Experience: A Mixed Methods Study.

BACKGROUND: Multiple system atrophy (MSA) is a rare Parkinson-plus syndrome with rapid progression and a high symptom burden. The experience of caregivers of people with MSA has not been closely examined. We therefore sought to document the impact of MSA on caregivers using a mixed methods approach. METHODS: Patients and caregivers were recruited from a movement disorders program in Edmonton, Canada. Participants completed the following survey instruments based on their own or their loved one's symptoms: 36-Item Short-Form Health Survey (SF-36), Multiple System Atrophy health-related Quality of Life scale (MSA-QoL), and Hospital Anxiety and Depression Scale (HADS). Caregivers also completed the Zarit Burden Interview and HADS based on their own experience. Qualitative data were obtained through semi-structured interviews. RESULTS: Nine people with MSA (PwMSA) (age range: 48-78 years) and 11 caregivers (49-76 years) participated. All completed surveys; 7 PwMSA and 10 caregivers were interviewed. Eight PwMSA had the parkinsonian type of MSA (MSA-P) and one a mixed type. Caregivers had on average mild-moderate caregiver burden and mild anxiety. Caregiver burden and anxiety were correlated. Qualitative subthemes under the caregiving theme included keeping the patient safe, caregivers' own health, and communication symptoms cause frustration. The rapid progression of illness was bewildering to caregivers and increased their workload. Public home care services were invaluable to caregivers' maintaining their loved ones at home. Caregivers were inventive in finding sources of hope and quality of life for their loved ones. CONCLUSION: Publicly funded home care was essential for caregivers of PwMSA in this study. Caregiver support is needed to provide this unrecognized workforce with information and resources to face this challenging condition.

Contribution of central sleep apnea to severe sleep apnea hypopnea syndrome.

PURPOSE: Central sleep apnea (CSA) is usually distinguished from obstructive sleep apnea (OSA). In fact, CSA is often a component of severe sleep apnea hypopnea syndrome (SAHS), rather than occurring alone. We investigated the clinical characteristics and polysomnography (PSG) parameters of CSA components in patients with severe SAHS. METHODS: The clinical characteristics and PSG parameters were retrospectively analyzed. RESULTS: Pure or dominant CSA was rare (5% of all patients). Of all patients with CSA, 72% also exhibited other apnea subtypes that contributed to severe SAHS. Among patients with severe SAHS, those with CSA were more likely than others to be older; thinner; exhibit higher prevalences of comorbid coronary heart disease, arrhythmia, and heart failure; a higher apnea/hypopnea index (AHI); mixed apnea index (MAI); an elevated oxygen desaturation index (ODI); and more nighttime oxygen saturation levels < 90%. Multivariate logistic regression analysis revealed that older age, comorbid arrhythmia or heart failure, and an elevated ODI were independently associated with CSA. CONCLUSION: Patients who complain of snoring or apnea may be better evaluated by comprehensive PSG prior to treatment if they are old, show greater hypoxia, or suffer from arrhythmia and/or heart failure, because such patients are more likely than others to exhibit CSA.

Magnetic sphincter augmentation: paradigm change or just another device in the surgeon's toolbox?

The common denominator for virtually all episodes of gastroesophageal reflux in health and disease is the loss of the barrier that confines the distal esophagus to the stomach. Factors important in maintaining the function of the barrier are its pressure, length and position. In early reflux disease, overeating, gastric distention and delayed gastric emptying led to a transient loss of the barrier. A permanent loss of the barrier occurs from inflammatory injury to the muscle allowing free flow of gastric juice into the esophageal body. Corrective therapy requires augmentation or restoration of the barrier referred to more commonly as the lower esophageal sphincter.

Criteria of patient selection for magnetic sphincter augmentation.

This article is an expert review of published literature with the goal of defining the ideal patient selection for Magnetic Sphincter Augmentation (MSA) in Anti-reflux Surgery (ARS). The authors performed a literature search of outcomes after MSA for different patient populations. Although MSA utilization has expanded to include patients with advanced gastroesophageal reflux disease (GERD), obese patients, and patients with a history of bariatric surgery there is still a paucity of data to support its definitive use in these cohorts. We concluded that younger patients with mild/moderate GERD as evidenced by objective studies in conjunction with normal motility on manometry have the most favorable outcomes after MSA. MSA should be avoided in patients with allergies to nickel, titanium, stainless steel, or ferrous materials. As the utilization of MSA in ARS continues to expand and as more robust data emerges the ideal patient for this device will likely expand as well.

Magnetic sphincter augmentation and high-resolution manometry: impact of biomechanical properties on esophageal motility and clinical significance for selection and outcomes.

Magnetic sphincter augmentation (MSA)was introduced as an alternative to laparoscopic Nissen fundoplication (LNF). This reproducible, outpatient procedure addresses the etiology of gastroesophageal reflux disease by implanting a ring of magnetic beads across the esophagogastric junction (EGJ). MSA is designed to resist effacement of the lower esophageal sphincter (LES) and, similar to LNF, results in restoration of anti-reflux barrier competency by increasing overall length, intraabdominal length and resting pressure of the sphincter. However, the novel use of magnets to augment the physiology of the LES poses unique challenges to the physiology of the EGJ and esophagus. These impacts are best revealed through manometry. The degree of restrictive forces at the EGJ, as measured by intrabolus pressure and integrated relaxation pressure, is higher after MSA compared with LNF. In addition, contrary to the LNF, which retains neurohormonal relaxation capability during deglutition, the magnetic forces remain constant until forcibly opened. Therefore, the burden of overcoming EJG resistance is placed solely on the esophageal body contractile force, as measured by distal contractile integral and distal esophageal amplitude. The main utility of preoperative manometry is in determining whether a patient's esophagus has sufficient contractility or peristaltic reserve to adapt to the challenge of an MSA. Manometric thresholds predictive of MSA outcomes deviate from those used to define named Chicago Classification motility disorders. Therefore, individual preoperative manometric characteristics should be analyzed to aid in risk stratification and patient selection prior to MSA.