Browsing by Author "Martinez, Gonzalo"

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    Association between spontaneous internal carotid artery dissection and perivascular adipose tissue attenuation on computed tomography angiography
    (2023) Cheng, Kevin; Lin, Andrew; Stecher, Ximena; Bernstein, Tomas; Zuniga, Paulo; Mazzon, Enrico; Brunser, Alejandro; Diaz, Violeta; Martinez, Gonzalo; Cameron, William; Nicholls, Stephen J.; Patel, Sanjay; Dey, Damini; Wong, Dennis T. L.; Venturelli, Paula Munoz
    Background: Spontaneous cervical artery dissection (sCAD) is a leading cause of ischemic stroke in young patients. Studies using high-resolution magnetic resonance imaging and positron emission tomography have suggested vessel wall inflammation to be a pathogenic factor in sCAD. Computed tomography (CT) attenuation of perivascular adipose tissue (PVAT) is an established non-invasive imaging biomarker of inflammation in coronary arteries, with higher attenuation values reflecting a greater degree of vascular inflammation. Objectives: We evaluate the CT attenuation of PVAT surrounding the internal carotid artery (PVAT(carotid)) with and without spontaneous dissection. Methods: Single-center prospective observational study of 56 consecutive patients with CT-verified spontaneous dissection of the internal carotid artery (ICA). Of these patients, six underwent follow-up computed tomography angiography (CTA). Twenty-two patients who underwent CTA for acute neurological symptoms but did not have dissection formed the control group. Using semi-automated research software, PVAT(carotid) was measured as the mean Hounsfield unit (HU) attenuation of adipose tissue within a defined volume of interest surrounding the ICA. Results: PVAT(carotid) was significantly higher around dissected ICA compared with non-dissected contralateral ICA in the same patients (-58.7 +/- 10.2 vs -68.9 +/- 8.1 HU, p < 0.0001) and ICA of patients without dissection (-58.7 +/- 10.2 vs -69.3 +/- 9.3 HU, p < 0.0001). After a median follow-up of 89 days, there was a significant reduction in PVAT(carotid) around dissected ICA (-57.5 +/- 13.4 to -74.3 +/- 10.5 HU, p < 0.05), while no change was observed around non-dissected contralateral ICA (-71.0 +/- 4.4 to -74.1 +/- 4.1 HU, p = 0.19). ICA dissection was an independent predictor of PVAT(carotid) following multivariable adjustment for age and the presence of ICA occlusion. Conclusion: PVAT(carotid) is elevated in the presence of sCAD and may decrease following the acute event.
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    Distribution, Invasion History, and Ecology of Non-native Pine Bark Beetles (Coleoptera: Curculionidae: Scolytinae) in Southern South America
    (2024) Lantschner, Victoria; Gomez, Demian F.; Vilardo, Gimena; Stazione, Leonel; Ramos, Sergio; Eskiviski, Edgar; Fachinetti, Romina; Schiappacassi, Marcela; Vallejos, Natalia; Germano, Monica; Villacide, Jose; Grilli, Mariano P.; Martinez, Gonzalo; Ahumada, Rodrigo; Estay, Sergio A.; Dumois, Ignacio; Corley, Juan
    The growth of international trade, coupled with an expansion of large-scale pine plantations in South America during the second half of the twentieth century, has significantly increased the opportunities for the invasion of forest insects. Bark beetles (Coleoptera: Curculionidae, Scolytinae) are a large and diverse group of insects, commonly recognized as one of the most important tree mortality agents in coniferous forests worldwide and an important group among invasive forest species. In this study, we combined data from field sampling with published records of established non-native pine bark beetles, to describe their distribution and invasion history in pine plantations across southern South America, reviewing the available information on their phenology and host range. We obtained records of established populations of six Eurasian species distributed in two major regions: the southwest region comprises plantations in Chile and the Argentine Patagonia, with four bark beetle species: Hylastes ater, Hylastes linearis, Hylurgus ligniperda, and Orthotomicus laricis; the northeastern zone includes northeastern Argentina, Uruguay, and southern Brazil, and includes three bark beetle species: Cyrtogenius luteus, H. ligniperda, and O. erosus. The establishment of non-native populations across the study area began in the 1950s, and from the 1980s onwards, there has been an exponential increase in introductions. We predict that several of these species will continue spreading across South America and that new species will continue arriving. We highlight the importance of international collaboration for early detection and management of non-native pine bark beetles.
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    Heart rate and cardiac autonomic responses to concomitant deep breathing, hand grip exercise, and circulatory occlusion in healthy young adult men and women
    (2021) Andrade Andrade, David Cristóbal; Melipillan, Claudia; Toledo, Camilo; Rios-Gallardo, Angélica; Marcus, Noah J.; Ortiz, Fernando C.; Martinez, Gonzalo; Muñoz Venturelli, Paula; Río Troncoso, Rodrigo Andre del
    Background: Deep breathing (DB) and handgrip (HG) exercise -with and without circulatory occlusion (OC) in muscle-, have been shown to have beneficial effects on cardiovascular function; however, the combination of these maneuvers on heart rate (HR) and cardiac sympathovagal balance have not been previously investigated. Therefore, the aim of the present study was to evaluate the effect of simultaneous DB, HG, and OC maneuvers on the sympathovagal balance in healthy women and men subjects. Methods and results: Electrocardiogram and ventilation were measured in 20 healthy subjects (Women: n = 10; age = 27 ± 4 years; weight = 67.1 ± 8.4 kg; and height = 1.6 ± 0.1 m. Men: n = 10; age = 27 ± 3 years; weight = 77.5 ± 10.1 kg; and height = 1.7 ± 0.1 m) at baseline and during DB, DB + HG, or DB + HG + OC protocols. Heart rate (HR) and respiratory rate were continuously recorded, and spectral analysis of heart rate variability (HRV) were calculated to indirectly estimate cardiac autonomic function. Men and women showed similar HR responses to DB, DB + HG and DB + HG + OC. Men exhibited a significant HR decrease following DB + HG + OC protocol which was accompanied by an improvement in cardiac autonomic control evidenced by spectral changes in HRV towards parasympathetic predominance (HRV High frequency: 83.95 ± 1.45 vs. 81.87 ± 1.50 n.u., DB + HG + OC vs. baseline; p < 0.05). In women, there was a marked decrease in HR after completion of both DB + HG and DB + HG + OC tests which was accompanied by a significant increase in cardiac vagal tone (HRV High frequency: 85.29 ± 1.19 vs. 77.93 ± 0.92 n.u., DB + HG vs. baseline; p < 0.05). No adverse effects or discomfort were reported by men or women during experimental procedures. Independent of sex, combination of DB, HG, and OC was tolerable and resulted in decreases in resting HR and elevations in cardiac parasympathetic tone. Conclusions: These data indicate that combined DB, HG and OC are effective in altering cardiac sympathovagal balance and reducing resting HR in healthy men and women.
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    MID-TERM FOLLOW UP OF BALLOON PULMONARY ANGIOPLASTY FOR INOPERABLE CHRONIC THROMBOEMBOLIC PULMONARY HYPERTENSION: INITIAL MULTICENTER EXPERIENCE IN CHILE
    (ELSEVIER SCIENCE INC, 2020) Andres Sepulveda, Pablo; Hameau, Rene; Backhouse, Christian; Charme, Gustavo; Ramirez, Pablo; Pacheco, Francisco; Fuensalida, Alberto; Quitral, Jorge; Martinez Sepulveda, Alejandro; Martinez, Gonzalo
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    Post-COVID-19 condition: a sex-based analysis of clinical and laboratory trends
    (2024) Delfino, Carlos; Poli, M. Cecilia; Vial, Cecilia; Vial, Pablo A.; Martinez, Gonzalo; Riviotta, Amy; Arbat, Catalina; Mac-Guire, Nicole; Hoppe, Josefina; Carvajal, Cristobal; Venturelli, Paula Munoz
    Background and aim Post-COVID-19 condition (PCC) encompasses long-lasting symptoms in individuals with COVID-19 and is estimated to affect between 31-67% of patients, with women being more commonly affected. No definitive biomarkers have emerged in the acute stage that can help predict the onset of PCC, therefore we aimed at describing sex-disaggregated data of PCC patients from a local cohort and explore potential acute predictors of PCC and neurologic PCC. Methods A local cohort of consecutive patients admitted with COVID-19 diagnosis between June 2020 and July 2021 were registered, and clinical and laboratory data were recorded. Only those <65 years, discharged alive and followed up at 6 and 12 months after admission were considered in these analyses. Multivariable logistic regression analysis was performed to explore variables associated with PCC (STATA v 18.0). Results From 130 patients in the cohort, 104 were contacted: 30% were women, median age of 42 years. At 6 months, 71 (68%) reported PCC symptoms. Women exhibited a higher prevalence of any PCC symptom (87 vs. 60%, p = 0.007), lower ferritin (p = 0.001) and procalcitonin (p = 0.021) and higher TNF levels (p = 0.042) in the acute phase compared to men. Being women was independently associated to 7.60 (95% CI 1.27-45.18, p = 0.026) higher risk for PCC. Moreover, women had lower return to normal activities 6 and 12 months. Conclusion Our findings highlight the lasting impact of COVID-19, particularly in young women, emphasising the need for tailored post-COVID care. The lower ferritin levels in women are an intriguing observation, warranting further research. The study argues for comprehensive strategies that address sex-specific challenges in recovery from COVID-19.