Acoustoelectric Time-Reversal for Ultrasound Phase-Aberration Correction.

Acoustoelectric imaging (AEI) is a technique that combines ultrasound (US) with radio frequency recording to detect and map local current source densities. This study demonstrates a new method called acoustoelectric time reversal (AETR), which uses AEI of a small current source to correct for phase aberrations through a skull or other US-aberrating layers with applications to brain imaging and therapy. Simulations conducted at three different US frequencies (0.5, 1.5, and 2.5 MHz) were performed through media layered with different sound speeds and geometries to induce aberrations of the US beam. Time delays of the acoustoelectric (AE) signal from a monopole within the medium were calculated for each element to enable corrections using AETR. Uncorrected aberrated beam profiles were compared with those after applying AETR corrections, which demonstrated a strong recovery (29%-100%) of lateral resolution and increases in focal pressure up to 283%. To further demonstrate the practical feasibility of AETR, we further conducted bench-top experiments using a 2.5 MHz linear US array to perform AETR through 3-D-printed aberrating objects. These experiments restored lost lateral restoration up to 100% for the different aberrators and increased focal pressure up to 230% after applying AETR corrections. Cumulatively, these results highlight AETR as a powerful tool for correcting focal aberrations in the presence of a local current source with applications to AEI, US imaging, neuromodulation, and therapy.

Cross-talk between TSC2 and the extracellular matrix controls pulmonary vascular proliferation and pulmonary hypertension.

Increased proliferation and survival of cells in small pulmonary arteries (PAs) drive pulmonary arterial hypertension (PAH). Because cell growth mediated by the mTOR-containing mTORC1 complex is inhibited by tuberous sclerosis complex 2 (TSC2), we investigated the role of this GTPase-activating protein in PAH pathology. TSC2 abundance was decreased in remodeled small PAs and PA vascular smooth muscle cells (PAVSMCs) from patients with PAH or from rodent pulmonary hypertension (PH) models, as well as PAVSMCs maintained on substrates that reproduced pathology-induced stiffness. Accordingly, mice with smooth muscle-specific reduction in TSC2 developed PH. At the molecular level, decreased TSC2 abundance led to stiffness-induced PAVSMC proliferation, increased abundance of the mechanosensitive transcriptional coactivators YAP/TAZ, and enhanced mTOR kinase activity. Moreover, extracellular matrix (ECM) produced by TSC2-deficient PAVSMCs stimulated the proliferation of nondiseased PA adventitial fibroblasts and PAVSMCs through fibronectin and its receptor, the α5ß1 integrin. Reconstituting TSC2 in PAVSMCs from patients with PAH through overexpression or treatment with the SIRT1 activator SRT2104 decreased YAP/TAZ abundance, mTOR activity, and ECM production, as well as inhibited proliferation and induced apoptosis. In two rodent models of PH, SRT2104 treatment restored TSC2 abundance, attenuated pulmonary vascular remodeling, and ameliorated PH. Thus, TSC2 in PAVSMCs integrates ECM composition and stiffness with pro-proliferative and survival signaling, and restoring TSC2 abundance could be an attractive therapeutic option to treat PH.

C3 Glomerulopathy, a pathology with scarce evidence. A case report.

C3 Glomerulonephritis (C3GN) is a rare disease with an estimated incidence of 1-2 cases per million, caused by an alteration in the alternative complement pathway, although its complete physiopathology remains uncertain. Treatment evidence is poor. Immunosuppressive therapy can be initiated in more severe cases. Progression rates to end stage kidney disease are of up to 50% within a decade, and the posttransplant recurrence rates of 45-60%. We describe the case of a young man without any past medical history, with lower extremities edema, dyspnea, and kidney function deterioration. The patient was ultimately diagnosed with C3GN.

Correlación de la distancia recorrida en la caminata de 6 minutos y puntajes de comorbilidad Charlson y Elixhauser / Correlation of distance traveled in the 6 minute walk and Charlson and Elihauser comorbidity scores

Introduction: The walking test of 6 minutes (6MW) is a test that merges the answer of different systems (respiratory, cardiovascular, metabolic, skeletal muscle and neurosensorial) and offers an useful objective result to lead therapeutic measurements and stablish a prognosis, it's possible that the comorbid patient lowers their functional reserve and alters the result of the test not only because of the presence of pathologies cardiorespiratory, nevertheless, information about the correlation between the scores of comorbidity and the traveled distance in the 6MW is limited. Objective: Determine the correlation between the traveled distance in the 6MW and the scores of comorbidities of Charlson and Elixhauser. Methods: A cross-sectional study was made, in patients taken to the 6MW made between 2006 until March 2020, in a hospital of high complexity; there were included patients older than 18 years old, whose clinic history record and walk of 6 minutes were available. The index of Charlson and Elixhauser were calculated in the 6MW, a bivariate analysis was made between the antecedents of pathologies and the traveled distance, independently and adjusted, the spearman correlation coefficient was calculated for the different scores and the distance in meters of the 6MW, was considerate a significative p: <0,05. Results: to the final analysis 491 subjects entered, the average age was of 69 years old (sd: 14,9), 54% male, the 15,3% had an abnormal walk less than the 80% of the expected, the diseases that were considered had a statistically significant relation with the decrease of the distance in the 6MW were arterial hypertension (p: <0,001), chronic heart failure (p=0,037), heart arrhythmia (p=0,003), smoking (p=0,022), chronic pulmonary obstruction disease (p: <0,001), dementia (p=0,03diabetes mellitus with target organ damage (p=0,01), moderate to severe chronic kidney disease (p=0,012), obesity (p=0,036) y lymphoma (p=0,038 the spearman correlation coefficient between the traveled distances and Charlson was of -0,343 (IC95%:-0,420 -0,264)(p: < 0,001) and -0,213(IC95%:-0,285 -0,116)(p: <0,001) with the Elixhauser index. Conclusion: The distances walked in meters in the 6MW has a reverse low correlation with the comorbidity index, the diseases that were not cardiopulmonary and that related independently with changes in the traveled dist ance are smoking, dementia, diabetes mellitus, chronic kidney disease, obesity, and lymphoma. Key words: Comorbidities, Walk, Test, Cardiopulmonary, Charlson, Elixhauser

Tercer caso de vasculitis leucocitoclástica cutánea secundaria al uso de oxacilina: reporte de caso / Third case in the literature of cutaneous leukocytoclastic vasculitis secondary to oxacilin use

Resumen La vasculitis leucocitoclastica es una patologìa que compromete los vasos pequeños y cuya causa predominantemente se ha descrito como idiopatica. Se presenta el caso de una mujer de 78 años hipertensa, diabética y con enfermedad renal crónica en estadio 5, que presentó lesiones limitadas a la piel posterior a la administración de oxacilina para manejo de bacteremia por SAMS. La presentación clínica se basó en purpuras palpables predominantemente en miembros inferiores y lesiones dolorosas coalescentes que formaban ampollas de contenido hemorrágico. Estas lesiones resolvieron gradualmente después del cambio de la terapia mencionada anteriormente. La biopsia fue compatible con vasculitis leucocitoclástica, con paraclínicos que descartaron causas infecciosas y autoinmunes.

Abstract Leukocytoclastic vasculitis is a pathology that involves small vessels and whose cause has been predominantly described as idiopathic. The clinical case of a 78-year-old woman with hypertension, diabetic and chronic stage 5 kidney disease, who presented limited skin lesions after administration of oxacillin for management of bacteremia by MSSA. The clinical presentation consisted on palpable purpura predominantly in the lower limbs and painful coalescent lesions that formed blisters of hemorrhagic content. Lesions gradually resolved after the change of the therapy mentioned above. The biopsy was compatible with leukocytocastic vasculitis, with paraclinics who ruled out infectious and autoimmune causes.

Criptococosis y linfocitopenia T CD4 idiopática: Reporte de un caso / Cryptococcosis and idiopathic CD4 T lymphocytopenia: A case report

Resumen La linfocitopenia T CD4 idiopática (LCI) es un síndrome clínico inusual que se caracteriza por un déficit de células T CD4+ circulantes en ausencia de infección por VIH u otra condición de inmunosupresión. Los pacientes con dicha enfermedad pueden presentarse asintomáticos o con infecciones oportunistas, las más frecuentes son por criptococo, micobacterias o virales como herpes zoster. Presentamos el caso de un hombre de 32 años, sin antecedentes, en quien se descartó infección por retrovirus, con recuento de linfocitos T CD4+ menor a 300 células/m3; se diagnosticó LCI posterior al diagnóstico de criptococomas cerebrales mediante hallazgos imagenológicos los cuales fueron congruentes con estudios microbiológicos.

Summary Idiopathic CD4 T lymphocytopenia (ICL) is an unusual clinical syndrome characterized by a deficit of circulating CD4 + T cells in the absence of HIV infection or another immunosuppression condition. Patients with this disease may present asymptomatic or with opportunistic infections, the most frequent are cryptococcus, mycobacteria or viral such as herpes zoster. We present a case of a 32-year-old man with no prior disease, in whom retrovirus infection was discarded, with CD4 + T lymphocyte count less than 300 cells/m3; ICL was diagnosed after the diagnosis of brain cryptococomas by imaging findings which were consistent with microbiological studies.

Acoustoelectric imaging of deep dipoles in a human head phantom for guiding treatment of epilepsy.

OBJECTIVE: This study employs a human head model with real skull to demonstrate the feasibility of transcranial acoustoelectric brain imaging (tABI) as a new modality for electrical mapping of deep dipole sources during treatment of epilepsy with much better resolution and accuracy than conventional mapping methods. APPROACH: This technique exploits an interaction between a focused ultrasound (US) beam and tissue resistivity to localize current source densities as deep as 63 mm at high spatial resolution (1 to 4 mm) and resolve fast time-varying currents with sub-ms precision. MAIN RESULTS: Detection thresholds through a thick segment of the human skull at biologically safe US intensities was below 0.5 mA and within range of strong currents generated by the human brain. SIGNIFICANCE: This work suggests that 4D tABI may emerge as a revolutionary modality for real-time high-resolution mapping of neuronal currents for the purpose of monitoring, staging, and guiding treatment of epilepsy and other brain disorders characterized by abnormal rhythms.

High resolution transcranial acoustoelectric imaging of current densities from a directional deep brain stimulator.

OBJECTIVE: New innovations in deep brain stimulation (DBS) enable directional current steering-allowing more precise electrical stimulation of the targeted brain structures for Parkinson's disease, essential tremor and other neurological disorders. While intra-operative navigation through MRI or CT approaches millimeter accuracy for placing the DBS leads, no existing modality provides feedback of the currents as they spread from the contacts through the brain tissue. In this study, we investigate transcranial acoustoelectric imaging (tAEI) as a new modality to non-invasively image and characterize current produced from a directional DBS lead. tAEI uses ultrasound (US) to modulate tissue resistivity to generate detectable voltage signals proportional to the local currents. APPROACH: An 8-channel directional DBS lead (Infinity 6172ANS, Abbott Inc) was inserted inside three adult human skulls submerged in 0.9% NaCl. A 2.5 MHz linear array delivered US pulses through the transtemporal window and focused near the contacts on the lead, while a custom amplifier and acquisition system recorded the acoustoelectric (AE) interaction used to generate images. MAIN RESULTS: tAEI detected monopolar current with stimulation pulses as short as 100 µs with an SNR ranging from 10-27 dB when using safe US pressure (mechanical indices <0.78) and injected current of ~2 mA peak amplitude. Adjacent contacts were discernable along the length and within each ring of the lead with a mean radial separation between contacts of 2.10 and 1.34 mm, respectively. SIGNIFICANCE: These results demonstrate the feasibility of tAEI for high resolution mapping of directional DBS currents using clinically-relevant stimulation parameters. This new modality may improve the accuracy for placing the DBS leads, guide calibration and programming, and monitor long-term performance of DBS for treatment of Parkinson's disease.

Fisiopatología de la hipertensión arterial secundaria a obesidad / Pathophysiology of hypertension secondary to obesity

Resumen: La obesidad es un problema de gran morbimortalidad a nivel mundial. Hoy en día, ha sido constituido como un factor de riesgo cardiovascular, que predispone frecuentemente al desarrollo de múltiples dolencias que deterioran la calidad de vida, tales como hipertensión arterial, dislipidemia y diabetes, que se relacionan con algunos de los criterios que se deben tener en cuenta en el diagnóstico del síndrome metabólico. Durante esta revisión, se busca explicar la relación entre la obesidad, el síndrome metabólico y el desarrollo de hipertensión arterial a partir de conceptos neurohumorales, bioquímicos y mecánicos.

Abstract: The obesity is a problem with a high morbidity and mortality all over the world. It has now been designated as a cardiovascular risk factor. It often predisposes the development of many diseases that reduce quality of life, such as hypertension, dyslipidaemia, and diabetes. These diseases are associated with some of the criteria that should be considered in the diagnosis of metabolic syndrome. During this review, explanations will be presented on the relationship between obesity, metabolic syndrome, and the development of hypertension from neurohumoral, biochemical and mechanical concepts.

[Pathophysiology of hypertension secondary to obesity]. / Fisiopatología de la hipertensión arterial secundaria a obesidad.

The obesity is a problem with a high morbidity and mortality all over the world. It has now been designated as a cardiovascular risk factor. It often predisposes the development of many diseases that reduce quality of life, such as hypertension, dyslipidaemia, and diabetes. These diseases are associated with some of the criteria that should be considered in the diagnosis of metabolic syndrome. During this review, explanations will be presented on the relationship between obesity, metabolic syndrome, and the development of hypertension from neurohumoral, biochemical and mechanical concepts.

Factores de riesgo cardiovascular enparticipantes de un programa masivode actividad física / Cardiovascular risk factors in participants of a massive program of physical activity

Objetivos: caracterizar los factores de riesgo cardiovascular en personas asistentes al programa ‘Muévete Bogotᒠy participantes del módulo de Recomendación y Asesoría en Actividad Física. Materiales y métodos: se contó con información de 3316 personas asistentes a un programa masivo de actividad física, a las cuales se les midió la antropometría; además se preguntó sobre antecedentes de salud, edad, tipo y nivel de actividad física practicada.Resultados: el 54 por ciento de los individuos tenía un peso adecuado, mientras que solo el 28,4 por ciento se clasificó como físicamente activo; de otra parte, las personas pertenecientes a la adultez temprana reportaron ser más sedentarias. El principal factor de riesgo reportado fue el sobrepeso, presente en el 40.3 por ciento de los individuos, y 1732 personas cuentan con la presencia de dos o más factores de riesgo cardiovascular. Discusión: cerca de la mitad de los individuos analizados podrían desarrollar enfermedades cardiovasculares en el futuro.