Persistent Challenges: A Comprehensive Review of Persistent Postural-Perceptual Dizziness, Controversies, and Clinical Complexities.

Persistent postural-perceptual dizziness (PPPD) is a chronic and disabling disorder characterized by persistent dizziness, unsteadiness, and imbalance. It often arises without an identifiable cause and is exacerbated by upright posture, active or passive movement, and exposure to moving or complex visual stimuli. This complex pathophysiology and the psychological dimensions of its symptomatology pose a significant challenge to clinicians. PPPD presents diagnostic challenges and a lack of standardized treatment options, underscoring the need for multidisciplinary approaches encompassing pharmacotherapy, vestibular rehabilitation, and psychological interventions for effective management. Bridging the gaps in understanding PPPD requires collaborative efforts across disciplines, emphasizing integrated research approaches and patient support networks to enhance care and improve outcomes. This review explores the challenges, controversies, and clinical complexities of PPPD, highlighting the importance of a patient-centered approach.

Topological Learning Approach to Characterizing Biological Membranes.

Biological membranes play key roles in cellular compartmentalization, structure, and its signaling pathways. At varying temperatures, individual membrane lipids sample from different configurations, a process that frequently leads to higher-order phase behavior and phenomena. Here, we present a persistent homology (PH)-based method for quantifying the structural features of individual and bulk lipids, providing local and contextual information on lipid tail organization. Our method leverages the mathematical machinery of algebraic topology and machine learning to infer temperature-dependent structural information on lipids from static coordinates. To train our model, we generated multiple molecular dynamics trajectories of dipalmitoyl-phosphatidylcholine membranes at varying temperatures. A fingerprint was then constructed for each set of lipid coordinates by PH filtration, in which interaction spheres were grown around the lipid atoms while tracking their intersections. The sphere filtration formed a simplicial complex that captures enduring key topological features of the configuration landscape using homology, yielding persistence data. Following fingerprint extraction for physiologically relevant temperatures, the persistence data were used to train an attention-based neural network for assignment of effective temperature values to selected membrane regions. Our persistence homology-based method captures the local structural effects, via effective temperature, of lipids adjacent to other membrane constituents, e.g., sterols and proteins. This topological learning approach can predict lipid effective temperatures from static coordinates across multiple spatial resolutions. The tool, called MembTDA, can be accessed at https://github.com/hyunp2/Memb-TDA.

Twelve-month outcomes of Kahook dual blade goniotomy combined with cataract surgery in Latino patients.

PURPOSE: To evaluate 12 month surgical outcome of Kahook Dual Blade (KDB) goniotomy in combination with cataract surgery in Latino patients with open angle glaucoma (OAG) and ocular hypertension (OHT). METHODS: This retrospective study included 45 eyes of 40 patients who underwent KDB goniotomy combined with cataract extraction from January 2016 to September 2020 at two centers in South America. Primary outcome was surgical success defined as ≥ 20% intraocular pressure (IOP) reduction or ≥ 1 medication reduction from preoperative without additional IOP-lowering procedures and an IOP ≥ 5 mmHg or ≤ 21 mmHg. Additionally, we used 2 cutoffs values for success of IOP ≤ 18 and ≤ 15 mmHg. Secondary outcomes included: IOP, medication use, best corrected visual acuity, complications and failure-associated factors. RESULTS: Success rates at 12 months with cutoff limits of 21, 18 and 15 mmHg were 84.3%, 75.6% and 58.7%, respectively. At 12 months, mean preoperative IOP significantly decreased from 19.23 ± 0.65 mmHg on 2.3 ± 1.0 medications to 14.33 ± 0.66 mmHg on 0.6 ± 0.9 medications (p < 0.001) , with 62% of eyes free of hypotensive medication. Eyes that developed postoperative IOP spikes showed a higher risk for failure using the cutoff limit of IOP ≤ 18 mmHg with a hazard ratio of 3.6 (95% confidence interval [CI], 1.80-7.13; p < 0.001). There were no serious ocular adverse events. CONCLUSIONS: KDB combined with cataract extraction showed safety and efficacy for decreasing IOP in OAG and OHT Latino patients. Additionally, dependence on medications was reduced significantly after surgery.

Topological Learning Approach to Characterizing Biological Membranes.

Biological membranes play key roles in cellular compartmentalization, structure, and its signaling pathways. At varying temperatures, individual membrane lipids sample from different configurations, a process that frequently leads to higher-order phase behavior and phenomena. Here we present a persistent homology-based method for quantifying the structural features of individual and bulk lipids, providing local and contextual information on lipid tail organization. Our method leverages the mathematical machinery of algebraic topology and machine learning to infer temperature-dependent structural information of lipids from static coordinates. To train our model, we generated multiple molecular dynamics trajectories of DPPC membranes at varying temperatures. A fingerprint was then constructed for each set of lipid coordinates by a persistent homology filtration, in which interactions spheres were grown around the lipid atoms while tracking their intersections. The sphere filtration formed a simplicial complex that captures enduring key topological features of the configuration landscape, using homology, yielding persistence data. Following fingerprint extraction for physiologically relevant temperatures, the persistence data were used to train an attention-based neural network for assignment of effective temperature values to selected membrane regions. Our persistence homology-based method captures the local structural effects, via effective temperature, of lipids adjacent to other membrane constituents, e.g. sterols and proteins. This topological learning approach can predict lipid effective temperatures from static coordinates across multiple spatial resolutions. The tool, called MembTDA, can be accessed at https://github.com/hyunp2/Memb-TDA.

Tuning sterol extraction kinetics yields a renal-sparing polyene antifungal.

Decades of previous efforts to develop renal-sparing polyene antifungals were misguided by the classic membrane permeabilization model1. Recently, the clinically vital but also highly renal-toxic small-molecule natural product amphotericin B was instead found to kill fungi primarily by forming extramembraneous sponge-like aggregates that extract ergosterol from lipid bilayers2-6. Here we show that rapid and selective extraction of fungal ergosterol can yield potent and renal-sparing polyene antifungals. Cholesterol extraction was found to drive the toxicity of amphotericin B to human renal cells. Our examination of high-resolution structures of amphotericin B sponges in sterol-free and sterol-bound states guided us to a promising structural derivative that does not bind cholesterol and is thus renal sparing. This derivative was also less potent because it extracts ergosterol more slowly. Selective acceleration of ergosterol extraction with a second structural modification yielded a new polyene, AM-2-19, that is renal sparing in mice and primary human renal cells, potent against hundreds of pathogenic fungal strains, resistance evasive following serial passage in vitro and highly efficacious in animal models of invasive fungal infections. Thus, rational tuning of the dynamics of interactions between small molecules may lead to better treatments for fungal infections that still kill millions of people annually7,8 and potentially other resistance-evasive antimicrobials, including those that have recently been shown to operate through supramolecular structures that target specific lipids9.

Vértigo en gestantes: presentación clínica, impacto en la calidad de vida y factores asociados / Vertigo in pregnancy: clinical presentation, impact on quality of life and associated factors

OBJETIVO: Evaluar las características clínicas, el impacto en la calidad de vida y los factores asociados con vértigo en gestantes hospitalizadas en una institución de alta complejidad. MÉTODO: Estudio transversal. Se realizó una encuesta dirigida a la presencia de vértigo y sus características clínicas en 2020-2021. La calidad de vida se evaluó con el cuestionario Dizziness Handicap Inventory (DHI). El análisis estadístico incluyó un modelo lineal generalizado. RESULTADOS: De 103 mujeres, el 19,4% indicaron vértigo principalmente en el segundo trimestre de gestación (60%), con una mediana de 3,5 (rango intercuartil: 1,5-7,5) episodios. Fueron referidos vértigos episódicos asociados con cambios posicionales (40%), acompañados de inestabilidad (60%), cefalea (60%), fotopsias (55%) y tinnitus (45%). Las mujeres con vértigo presentaron mayor frecuencia de discapacidad moderada a grave en las dimensiones del DHI emocional (30 vs. 2,4%; p = 0,001), funcional (40 vs. 2,4%; p < 0,001) y física (55 vs. 2,4%; p < 0,001) en comparación con las mujeres sin la patología. La hospitalización durante el embarazo Razón de proporción (RP): 4,02; intervalo de confianza del 95% [IC95%]: 1,64-9,85; p = 0,002) y la presencia de vértigo pregestacional (RP: 2,37; IC95%: 1,15-4,88; p = 0,019) se identificaron como factores asociados. CONCLUSIONES: La alta frecuencia de vértigo en las gestantes sugiere la importancia de estudiar esta condición durante el embarazo, para lograr un manejo integral y generar acciones de prevención y control efectivas.

OBJECTIVE: To evaluate clinical characteristics, impact on quality of life and factors associated with vertigo in pregnant women hospitalized in a highly complex institution. METHOD: A cross-sectional study was conducted in 2021-2022. One focused survey including Dizziness Handicap Inventory (DHI) was performed. The statistical analysis was performed using a generalized lineal regression. RESULTS: 103 patients were included, 19.4% indicated vertigo mostly during the second semester (60%). A median of 3.5 episodes was obtained (RIC: 1.5-7.5). Positional and episodic vertigos (40%) associated with unsteadiness (60%), headache (60%), photopsia (55%) and tinnitus (45%) were described. DHI in pregnant females with vertigo compared to those without vertigo, presented higher rates of moderate to severe disability in the emotional (30 vs. 2.4%: p = 0.001), functional (40 vs. 2.4%; p < 0.001) and physical (55 vs. 2.4%; p < 0.001) dimensions. Hospitalizations during the pregnancy (RP: 4.02; 95%CI: 1.64-9.85; p = 0.002) and previous episodes before pregnancy (RP: 2.37; 95%CI: 1.15-4.88; p = 0.019) were identified as associated factors with current vertigo episodes. CONCLUSIONS: The high frequency of vertigo in pregnant women suggests the importance of studying this condition during pregnancy, to achieve comprehensive management and generate effective prevention and control actions.

Oftalmoplejía infecciosa en un paciente con virus de la varicela-zóster / Infectious ophthalmoplegia in patients with varicella-zoster virus

Introducción: Una de las complicaciones de la reactivación del virus de la varicela-zóster es el compromiso de los nervios craneales; sin embargo, es inusual que se presente como una oftalmoplejía completa. Objetivo: Describir el caso de un adulto inmunocompetente que desarrolló una oftalmoplejía infecciosa por reactivación del virus de la varicela-zóster. Caso clínico: El paciente presentó alteración completa de la motilidad de los músculos extraoculares del ojo izquierdo con compromiso del reflejo pupilar, disminución en la agudeza visual y neuralgia trigeminal concomitante; no tuvo signos o síntomas sugestivos de encefalitis o meningitis. Días antes de la oftalmoplejía aparecieron vesículas en la región frontal y periorbitaria izquierdas. Mediante el estudio del líquido cefalorraquídeo (LCR) con panel para meningitis/encefalitis FilmArray® se documentó positividad solo para el virus de la varicela-zóster. El paciente fue tratado con aciclovir, esteroides y neuromoduladores, con lo cual obtuvo mejoría parcial de sus síntomas a las dos semanas. La discusión se realizó a partir de los pocos reportes de casos encontrados en diferentes bases de datos. Conclusiones: Este caso amplía el entendimiento clínico y terapéutico de una manifestación inusual de esta enfermedad frecuente, que combina un compromiso patológico de varios nervios craneales por la reactivación del virus de la varicela-zóster.

Introduction: Cranial nerve involvement is one of the complications of varicella-zoster virus reactivation; however, presenting complete ophthalmoplegia is unusual. Objective: To describe the case of an immunocompetent adult who developed an infectious ophthalmoplegia due to varicella-zoster virus reactivation. Clinical case: The patient presented complete alteration of the extraocular muscle motility of the left eye with pupillary reflex compromise, decrease in visual acuity and concomitant trigeminal neuralgia. The patient did not present signs or symptoms suggestive of encephalitis or meningitis. Days before the ophthalmoplegia, vesicles appeared in the left frontal and periorbital regions. Cerebrospinal fluid (CSF) examination with FilmArray® meningitis/encephalitis panel documented positivity for varicella-zoster virus only. The patient was treated with acyclovir, steroids and neuromodulators, resulting in partial improvement of his symptoms after two weeks. The discussion was based on the few case reports found in different databases. Conclusions: This case broadens the clinical and therapeutic understanding of an unusual manifestation of this common disease, which combines pathologic involvement of several cranial nerves due to varicella-zoster virus reactivation.

Vertigo in Pregnancy: A Narrative Review.

During pregnancy, physical, hormonal, and psychological changes may occur from conception to labor. Balance is also impacted throughout this time, leading to symptoms such as vertigo and unsteadiness. These symptoms may appear at any time and can cause disability and physical impairment. Little has been published about vertigo in pregnancy. We performed a narrative review of vertigo in pregnant patients. Vertigo in pregnant females may be associated with hormonal changes in peripheral structures and inner ear organs. Meniere's disease, vestibular migraine, and benign paroxysmal positional vertigo are usually exacerbated during pregnancy. Specific changes to hearing and proprioception in the physical examination are also noted between the second and third trimester of pregnancy. These symptoms are usually seen in pregnant patients throughout this time. Some types of vertigo may be exacerbated and others may present at any time of pregnancy. Further research is needed to understand the clinical and pathological association of audiovestibular symptoms during pregnancy.

Phthalate monoesters act through peroxisome proliferator-activated receptors in the mouse ovary.

Widespread use of phthalates as solvents and plasticizers leads to everyday human exposure. The mechanisms by which phthalate metabolites act as ovarian toxicants are not fully understood. Thus, this study tested the hypothesis that the phthalate metabolites monononyl phthalate (MNP), monoisononyl phthalate (MiNP), mono(2-ethylhexyl) phthalate (MEHP), monobenzyl phthalate (MBzP), monobutyl phthalate (MBP), monoisobutyl phthalate (MiBP), and monoethyl phthalate (MEP) act through peroxisome proliferator-activated receptors (PPARs) in mouse granulosa cells. Primary granulosa cells were isolated from CD-1 mice and cultured with vehicle control (dimethyl sulfoxide) or MNP, MiNP, MEHP, MBzP, MBP, MiBP, or MEP (0.4-400 µM) for 24 h. Following culture, qPCR was performed for known PPAR targets, Fabp4 and Cd36. Treatment with the phthalate metabolites led to significant changes in Fabp4 and Cd36 expression relative to control in dose-dependent or nonmonotonic fashion. Primary granulosa cell cultures were also transfected with a DNA plasmid containing luciferase expressed under the control of a consensus PPAR response element. MNP, MiNP, MEHP, and MBzP caused dose-dependent changes in expression of luciferase, indicating the presence of functional endogenous PPAR receptors in the granulosa cells that respond to phthalate metabolites. The effects of phthalate metabolites on PPAR target genes were inhibited in most of the cultures by co-treatment with the PPAR-γ inhibitor, T0070907, or with the PPAR-α inhibitor, GW6471. Collectively, these data suggest that some phthalate metabolites may act through endogenous PPAR nuclear receptors in the ovary and that the differing structures of the phthalates result in different levels of activity.

Use of Microscale Thermophoresis to Measure Protein-Lipid Interactions.

The ability to determine the binding affinity of lipids to proteins is an essential part of understanding protein-lipid interactions in membrane trafficking, signal transduction and cytoskeletal remodeling. Classic tools for measuring such interactions include surface plasmon resonance (SPR) and isothermal titration calorimetry (ITC). While powerful tools, these approaches have setbacks. ITC requires large amounts of purified protein as well as lipids, which can be costly and difficult to produce. Furthermore, ITC as well as SPR are very time consuming, which could add significantly to the cost of performing these experiments. One way to bypass these restrictions is to use the relatively new technique of microscale thermophoresis (MST). MST is fast and cost effective using small amounts of sample to obtain a saturation curve for a given binding event. There currently are two types of MST systems available. One type of MST requires labeling with a fluorophore in the blue or red spectrum. The second system relies on the intrinsic fluorescence of aromatic amino acids in the UV range. Both systems detect the movement of molecules in response to localized induction of heat from an infrared laser. Each approach has its advantages and disadvantages. Label-free MST can use untagged native proteins; however, many analytes, including pharmaceuticals, fluoresce in the UV range, which can interfere with determination of accurate KD values. In comparison, labeled MST allows for a greater diversity of measurable pairwise interactions utilizing fluorescently labeled probes attached to ligands with measurable absorbances in the visible range as opposed to UV, limiting the potential for interfering signals from analytes.

Anthracycline derivatives inhibit cardiac CYP2J2.

Anthracycline chemotherapeutics are highly effective, but their clinical usefulness is hampered by adverse side effects such as cardiotoxicity. Cytochrome P450 2J2 (CYP2J2) is a cytochrome P450 epoxygenase in human cardiomyocytes that converts arachidonic acid (AA) to cardioprotective epoxyeicosatrienoic acid (EET) regioisomers. Herein, we performed biochemical studies to understand the interaction of anthracycline derivatives (daunorubicin, doxorubicin, epirubicin, idarubicin, 5-iminodaunorubicin, zorubicin, valrubicin, and aclarubicin) with CYP2J2. We utilized fluorescence polarization (FP) to assess whether anthracyclines bind to CYP2J2. We found that aclarubicin bound the strongest to CYP2J2 despite it having large bulky groups. We determined that ebastine competitively inhibits anthracycline binding, suggesting that ebastine and anthracyclines may share the same binding site. Molecular dynamics and ensemble docking revealed electrostatic interactions between the anthracyclines and CYP2J2, contributing to binding stability. In particular, the glycosamine groups in anthracyclines are stabilized by binding to glutamate and aspartate residues in CYP2J2 forming salt bridge interactions. Furthermore, we used iterative ensemble docking schemes to gauge anthracycline influence on EET regioisomer production and anthracycline inhibition on AA metabolism. This was followed by experimental validation of CYP2J2-mediated metabolism of anthracycline derivatives using liquid chromatography tandem mass spectrometry fragmentation analysis and inhibition of CYP2J2-mediated AA metabolism by these derivatives. Taken together, we use both experimental and theoretical methodologies to unveil the interactions of anthracycline derivatives with CYP2J2. These studies will help identify alternative mechanisms of how anthracycline cardiotoxicity may be mediated through the inhibition of cardiac P450, which will aid in the design of new anthracycline derivatives with lower toxicity.

Amphiphilic Distyrylbenzene Derivatives as Potential Therapeutic and Imaging Agents for Soluble and Insoluble Amyloid ß Aggregates in Alzheimer's Disease.

Alzheimer's Disease (AD) is the most common neurodegenerative disease, and efficient therapeutic and early diagnostic agents for AD are still lacking. Herein, we report the development of a novel amphiphilic compound, LS-4, generated by linking a hydrophobic amyloid-binding distyrylbenzene fragment with a hydrophilic triazamacrocycle, which dramatically increases the binding affinity toward various amyloid ß (Aß) peptide aggregates, especially for soluble Aß oligomers. Moreover, upon the administration of LS-4 to 5xFAD mice, fluorescence imaging of LS-4-treated brain sections reveals that LS-4 can penetrate the blood-brain barrier and bind to the Aß oligomers in vivo. In addition, the treatment of 5xFAD mice with LS-4 reduces the amount of both amyloid plaques and associated phosphorylated tau aggregates vs the vehicle-treated 5xFAD mice, while microglia activation is also reduced. Molecular dynamics simulations corroborate the observation that introducing a hydrophilic moiety into the molecular structure of LS-4 can enhance the electrostatic interactions with the polar residues of the Aß species. Finally, exploiting the Cu2+-chelating property of the triazamacrocycle, we performed a series of imaging and biodistribution studies that show the 64Cu-LS-4 complex binds to the amyloid plaques and can accumulate to a significantly larger extent in the 5xFAD mouse brains vs the wild-type controls. Overall, these results illustrate that the novel strategy, to employ an amphiphilic molecule containing a hydrophilic moiety attached to a hydrophobic amyloid-binding fragment, can increase the binding affinity for both soluble and insoluble Aß aggregates and can thus be used to detect and regulate various Aß species in AD.

Bioprosthetic Valve Thrombosis and Obstruction Secondary to COVID-19.

Patients with COVID-19 may present a hypercoagulable state, with an important impact on morbidity and mortality. Because of this situation pulmonary embolism is a frequent complication during the course of infection. We present the case of a patient recently discharged, after admission with confirmed COVID-19, who developed a pulmonary embolism and thrombosis of a biological mitral valve prosthesis, producing valve obstruction and stenosis. After 15 days of anticoagulant treatment, resolution of the thrombus and normalisation of prosthetic valve function was observed. This case supports current recommendations of administering full-dose anticoagulation therapy to COVID-19 patients with biological heart valve prosthesis, even after the acute phase of infection.

[Prognostic factors of mortality one year after a hip fragility fracture. Anoia hip study]. / Factores pronósticos de mortalidad al año de una fractura de cadera por fragilidad ósea. Estudio Maluc Anoia.

INTRODUCTION: Most of the patients who had a hip fragility fracture are characterized by advanced age, frailty, multimorbidity and high mortality rate into the first year. Our aim is to describe the prognostic factors of mortality one year after a hip fragility fracture. MATERIAL AND METHODS: Observational prospective study. During the study period we included patients older than 69 years with hip fragility fracture who were admitted to the Acute Geriatric Unit. RESULTS: We have followed 364 patients, 100 of them died (27.5%). The independent prognostic factors of mortality one year after a hip fragility fracture had been: have a less basis score in Lawton and Brody Scale 0.603 (0.505-0.721) (p< 0.001); have a higher score in Charlson Comorbidity Index 2.332 (1.308-4.157) p = 0.04); have a surgical waiting time ≥ 3 days 3.013 (1.330-6.829) p = 0.008); finding hydroelectrolytic disorders and/or deterioration of glomerular filtration 1.212 (1.017-1.444) p = 0.031) during hospital stay; discriminatory capacity of the area under the curve (AUC) (± 95%): 0.888 (0.880-0.891). CONCLUSIONS: Prognostic predictors of mortality at one year after a hip fragility fracture are those variables that reflect a worse state of health, complications during hospital stay and a longer surgical waiting time.

An Allosteric Binding Site on Sortilin Regulates the Trafficking of VLDL, PCSK9, and LDLR in Hepatocytes.

ApoB lipoproteins (apo B-Lp) are produced in hepatocytes, and their secretion requires the cargo receptor sortilin. We examined the secretion of apo B-Lp-containing very low-density lipoprotein (VLDL), an LDL progenitor. Sortilin also regulates the trafficking of the subtilase PCSK9, which when secreted binds the LDL receptor (LDLR), resulting in its endocytosis and destruction at the lysosome. We show that the site 2 binding compound (cpd984) has multiple effects in hepatocytes, including (1) enhanced Apo-Lp secretion, (2) increased cellular PCSK9 retention, and (3) augmented levels of LDLR at the plasma membrane. We postulate that cpd984 enhances apo B-Lp secretion in part through binding the lipid phosphatidylinositol 3,4,5-trisphosphate (PIP3), which is present at higher levels on circulating VLDL form fed rats relative to after fasting. We attribute the enhanced VLDL secretion to its increased binding affinity for sortilin site 1 induced by cpd984 binding site 2. This hinders PCSK9 binding and secretion, which would subsequently prevent its binding to LDLR leading to its degradation. This suggests that site 2 is an allosteric regulator of site 1 binding. This effect is not limited to VLDL, as cpd984 augments binding of the neuropeptide neurotensin (NT) to sortilin site 1. Molecular dynamics simulations demonstrate that the C-terminus of NT (Ct-NT) stably binds site 1 through an electrostatic interaction. This was bolstered by the ability of Ct-NT to disrupt lower-affinity interactions between sortilin and the site 1 ligand PIP3. Together, these data show that binding cargo at sortilin site 1 is allosterically regulated through site 2 binding, with important ramifications for cellular lipid homeostasis involving proteins such as PCSK9 and LDLR.

Sobrecarga del cuidador de pacientes con atrofia muscular espinal / Caregiver burden in spinal muscular atrophy

INTRODUCCIÓN La sobrecarga del cuidador ha sido ampliamente descrita en gerontología, pocos estudios la abordan en niños con enfermedades neuromusculares. El cuidado de pacientes con atrofia muscular espinal (AME), requiere atención continua de un tercero, pudiendo afectar la salud del cuidador y la calidad de atención y bienestar del paciente. El objetivo del estudio fue determinar el nivel de sobrecarga de los cuidadores de pacientes AME, identificando factores protectores y de riesgo asociados MÉTODOS Estudio observacional analítico transversal en padres de pacientes con AME, de un hospital privado de Santiago de Chile. Se analizaron datos demográficos clínicos y encuesta Zarit autoreportada por los padres de los pacientes con AME, realizada entre septiembre de 2017 y febrero de 2018. Se usó estadística descriptiva y regresión logística uni y multivariada para identificar factores asociados a sobrecarga RESULTADOS De los 50 padres encuestados, 14 (28%) eran de pacientes non-sitters, con sobrecarga intensa, mediana de puntaje 59 (37-76), 29 (58%) de pacientes sitters sobrecarga ligera, mediana 48 (32-79) y 7(14%) de pacientes walkers, ausencia de sobrecarga mediana 38 (23-54). Se identificaron como factores protectores de sobrecarga los años de enfermedad OR 0,9 (0,8-0,95) P=0,037 y la mayor edad de los pacientes OR 0,9(08,0,98) p=0,018. Factores de riesgo el uso de silla de ruedas OR 7,2(1,2-4,3) p=0,029 y la vía de alimentación artificial OR 9,2(1-78,8) p=0,040 CONCLUSIÓN Los padres de pacientes con AME tienen un significativo nivel de sobrecarga y existen factores que la aumentan y disminuyen. El equipo multidisciplinario debe integrar la medición periódica del nivel de sobrecarga, para intervenir oportunamente y procurar el cuidado integral de la familia.

Caregiver burden has been widely described in gerontology, few studies address it in children with neuromuscular diseases. The care of patients with spinal muscular atrophy (SMA) requires permanent care from a third person, which may affect the caregiver health, quality of care and well-being of the patient. The aim of the study was to determine the burden of SMA patient's caregivers, identifying associated protective and risk factors METHODS Descriptive cross-sectional analytical study in SMA patient's parents, from a private hospital in Santiago de Chile., demographic Clinical and self-reported Zarit survey data, parents self reported, conducted between September 2017 and February 2018, were analyzed. Descriptive statistics and uni and multivariate logistic regression were used to identify factors associated with overloading RESULTS Parents of non-sitter patients showed a median of 59 (37-76), corresponding to intense burden and those of sitters, a light burden, with a median score of 48 (32-79) Walkers patient's parents, presented a median score of 38 (23-54) that corresponds to an absence of burden. The years of illness and the higher age of the patients were identified as protective factors of overload. As risk factors of burden, the use of a wheelchair and artificial airway. Of the 50 parents surveyed, 14 (28%) were non-sitter patients, with intense overload, median 59(37-76), 29(58%) sitters patients, light overload, median 48 (32-79) and 7(14%) walker patients, absence of overload, median 38 (23-54). Protective factors of overload were years of disease OR 0,9(0,8-0,95) p=0.037 and the patients major age OR 0.9(0.8-0.98) p=0.018. Risk factors were the use of wheelchair OR 7,2(1,2-4,3) p=0.029 and artificial feeding support OR 9,2(1-78.8) p=0.040 CONCLUSION SMA patient's parents have a significant level of overload and there are factors that increase and decrease it. The multidisciplinary team must integrate the periodic measurement of the burden level, to make on time interventions and to ensure the integral care in the family.

Spontaneous symptomatic improvement in a pediatric patient with anti-3-hydroxy-3-methylglutraryl-coenzyme A reductase myopathy.

Immune-mediated necrotizing myopathy with antibodies against 3-hydroxy-3-methylglutaryl-coenzyme A reductase is a subgroup of idiopathic inflammatory myopathies mainly described in adults and requiring long term immunomodulatory therapy for remission. Pediatric patients have been reported as small series or sporadic cases. We report an eight-year-old girl with anti-3-hydroxy-3-methylglutaryl-coenzyme A reductase myopathy, presenting with subacute proximal limb weakness, high creatine kinase and a muscle biopsy displaying necrotizing pattern, initially diagnosed as limb-girdle muscular dystrophy, but subsequently negative genetic testing. A noteworthy spontaneous improvement in her weakness suggested the possibility of an acquired autoimmune myopathy, confirmed by positive testing of anti-HMGCR antibodies titers. After four years of follow-up, she maintains normal strength with high levels of anti-3-hydroxy-3-methylglutaryl-coenzyme A reductase antibody. This patient shows that spontaneous fluctuations and spontaneous long-lasting symptomatic remission can occur in patients with anti-3-hydroxy-3-methylglutaryl-coenzyme A reductase myopathy. Some patients could present a wane and wax clinical course, an important aspect when assessing response to therapy.

Aß(1-42) tetramer and octamer structures reveal edge conductivity pores as a mechanism for membrane damage.

Formation of amyloid-beta (Aß) oligomer pores in the membrane of neurons has been proposed to explain neurotoxicity in Alzheimer's disease (AD). Here, we present the three-dimensional structure of an Aß oligomer formed in a membrane mimicking environment, namely an Aß(1-42) tetramer, which comprises a six stranded ß-sheet core. The two faces of the ß-sheet core are hydrophobic and surrounded by the membrane-mimicking environment while the edges are hydrophilic and solvent-exposed. By increasing the concentration of Aß(1-42) in the sample, Aß(1-42) octamers are also formed, made by two Aß(1-42) tetramers facing each other forming a ß-sandwich structure. Notably, Aß(1-42) tetramers and octamers inserted into lipid bilayers as well-defined pores. To establish oligomer structure-membrane activity relationships, molecular dynamics simulations were carried out. These studies revealed a mechanism of membrane disruption in which water permeation occurred through lipid-stabilized pores mediated by the hydrophilic residues located on the core ß-sheets edges of the oligomers.