Changes in clinical characteristics and outcomes of patients hospitalized with COVID-19 during two years of the pandemic: experience in a venezuelan hospital. / Cambios en las características clínicas y desenlaces de pacientes hospitalizados por COVID-19 durante dos años de pandemia: experiencia en un hospital venezolano.

OBJECTIVES.: To determine changes in the clinical characteristics and in-hospital outcomes of patients hospitalized for COVID-19 in a private hospital in Caracas during two years of the pandemic. MATERIALS AND METHODS.: Retrospective, observational study of patients hospitalized for COVID-19. We evaluated the correspondence between waves of hospital admissions and circulating variants of SARS-CoV-2 in the general population of the Capital District and Miranda state. RESULTS.: A total of 1025 patients (569 men and 456 women) were included, with a mean age of 62.9 SD: 16.2 years. Four waves of hospital admissions were identified: first (March-November 2020) 150/1025 (14.6%) cases; second (December 2020 to May 2021) 415/1025 (40.5%) cases; third (June-December 2021) 344/1025 (33.6%) cases; fourth (January-February 2022) 116/1025 (11.3%) cases. The mean age was higher in the fourth wave (first: 64.0±15.7, second: 61.4±15.8, third: 62.1±16.5, and fourth wave: 68.5±16.4), while the proportion of male patients (first: 66.7%, second: 58.8%, third: 50.3%, and fourth wave: 44.8%), patients with severe-critical illness (first: 65.3%, second: 57%, third: 51.7%, and fourth wave: 44.8%), in-hospital stay (first: 9.1±6.0, second: 9.0±7.3, third: 8.8±7.7, and fourth wave: 6.9±5.0 days), ICU admissions (first: 23.3%, second: 15.7%, third: 14.0%, and fourth wave: 11.2%; p=0.027) and mortality (first: 21. 8%, second: 10.7%, third: 9.1%, and fourth wave: 7.1%; p<0.001) progressively decreased over time. CONCLUSIONS.: The results show lower frequency of severe cases and improvement of in-hospital outcomes in two years of the pandemic. Changes in circulating variants, improvements in disease management and vaccination are likely to have influenced these results.

OBJETIVOS.: Determinar los cambios en las características clínicas y desenlaces intrahospitalarios de los pacientes hospitalizados por COVID-19 en un hospital privado de Caracas durante dos años de pandemia. MATERIALES Y MÉTODOS.: Estudio retrospectivo, observacional, de pacientes hospitalizados por COVID-19. Se investigó la correspondencia entre las olas de ingresos hospitalarios con las variantes circulantes del SARS-CoV-2 en la población general del Distrito Capital y estado Miranda. RESULTADOS.: Se incluyeron 1025 pacientes (569 hombres y 456 mujeres), con edad promedio de 62,9 DE: 16,2 años. Cuatro olas de ingresos hospitalarios fueron identificadas: primera (marzo-noviembre 2020) 150/1025 (14,6%) casos; segunda (diciembre-2020 a mayo-2021) 415/1025 (40,5%) casos; tercera (junio-diciembre 2021) 344/1025 (33,6%) casos; cuarta (enero-febrero 2022) 116/1025 (11,3%) casos. La edad promedio fue mayor en la cuarta ola (primera 64,0±15,7, segunda 61,4±15,8, tercera 62,1±16,5, y cuarta ola 68,5±16,4), mientras que la proporción de pacientes masculinos (primera 66,7%, segunda 58,8%, tercera 50,3%, y cuarta 44,8%), los pacientes con enfermedad grave-crítica (primera 65,3%, segunda 57%, tercera 51,7% y cuarta 44,8%), la estadía intrahospitalaria (primera 9,1±6,0, segunda 9,0±7,3, tercera 8,8±7,7, y cuarta 6,9±5,0 días), los ingresos a la UCI (primera 23,3%, segunda 15,7%, tercera 14,0%, y cuarta 11,2%; p=0,027) y la mortalidad (primera 21.8%, segunda 10,7%, tercera 9,1%, y cuarta 7,1%; p<0,001) disminuyeron progresivamente con el tiempo. CONCLUSIONES.: Los resultados muestran menor frecuencia de casos severos y mejoría de los desenlaces intrahospitalarios en dos años de pandemia. Es probable que los cambios en las variantes circulantes, las mejoras del manejo de la enfermedad y la vacunación hayan influido sobre estos resultados.

Cambios en las características clínicas y desenlaces de pacientes hospitalizados por COVID-19 durante dos años de pandemia: experiencia en un hospital venezolano / Changes in clinical characteristics and outcomes of patients hospitalized with COVID-19 during two years of the pandemic: experience in a venezuelan hospital

RESUMEN Objetivos. Determinar los cambios en las características clínicas y desenlaces intrahospitalarios de los pacientes hospitalizados por COVID-19 en un hospital privado de Caracas durante dos años de pandemia. Materiales y métodos. Estudio retrospectivo, observacional, de pacientes hospitalizados por COVID-19. Se investigó la correspondencia entre las olas de ingresos hospitalarios con las variantes circulantes del SARS-CoV-2 en la población general del Distrito Capital y estado Miranda. Resultados. Se incluyeron 1025 pacientes (569 hombres y 456 mujeres), con edad promedio de 62,9 DE: 16,2 años. Cuatro olas de ingresos hospitalarios fueron identificadas: primera (marzo-noviembre 2020) 150/1025 (14,6%) casos; segunda (diciembre-2020 a mayo-2021) 415/1025 (40,5%) casos; tercera (junio-diciembre 2021) 344/1025 (33,6%) casos; cuarta (enero-febrero 2022) 116/1025 (11,3%) casos. La edad promedio fue mayor en la cuarta ola (primera 64,0±15,7, segunda 61,4±15,8, tercera 62,1±16,5, y cuarta ola 68,5±16,4), mientras que la proporción de pacientes masculinos (primera 66,7%, segunda 58,8%, tercera 50,3%, y cuarta 44,8%), los pacientes con enfermedad grave-crítica (primera 65,3%, segunda 57%, tercera 51,7% y cuarta 44,8%), la estadía intrahospitalaria (primera 9,1±6,0, segunda 9,0±7,3, tercera 8,8±7,7, y cuarta 6,9±5,0 días), los ingresos a la UCI (primera 23,3%, segunda 15,7%, tercera 14,0%, y cuarta 11,2%; p=0,027) y la mortalidad (primera 21.8%, segunda 10,7%, tercera 9,1%, y cuarta 7,1%; p<0,001) disminuyeron progresivamente con el tiempo. Conclusiones. Los resultados muestran menor frecuencia de casos severos y mejoría de los desenlaces intrahospitalarios en dos años de pandemia. Es probable que los cambios en las variantes circulantes, las mejoras del manejo de la enfermedad y la vacunación hayan influido sobre estos resultados.

ABSTRACT Objectives. To determine changes in the clinical characteristics and in-hospital outcomes of patients hospitalized for COVID-19 in a private hospital in Caracas during two years of the pandemic. Materials and Methods. Retrospective, observational study of patients hospitalized for COVID-19. We evaluated the correspondence between waves of hospital admissions and circulating variants of SARS-CoV-2 in the general population of the Capital District and Miranda state. Results. A total of 1025 patients (569 men and 456 women) were included, with a mean age of 62.9 SD: 16.2 years. Four waves of hospital admissions were identified: first (March-November 2020) 150/1025 (14.6%) cases; second (December 2020 to May 2021) 415/1025 (40.5%) cases; third (June-December 2021) 344/1025 (33.6%) cases; fourth (January-February 2022) 116/1025 (11.3%) cases. The mean age was higher in the fourth wave (first: 64.0±15.7, second: 61.4±15.8, third: 62.1±16.5, and fourth wave: 68.5±16.4), while the proportion of male patients (first: 66.7%, second: 58.8%, third: 50.3%, and fourth wave: 44.8%), patients with severe-critical illness (first: 65.3%, second: 57%, third: 51.7%, and fourth wave: 44.8%), in-hospital stay (first: 9.1±6.0, second: 9.0±7.3, third: 8.8±7.7, and fourth wave: 6.9±5.0 days), ICU admissions (first: 23.3%, second: 15.7%, third: 14.0%, and fourth wave: 11.2%; p=0.027) and mortality (first: 21. 8%, second: 10.7%, third: 9.1%, and fourth wave: 7.1%; p<0.001) progressively decreased over time. Conclusions. The results show lower frequency of severe cases and improvement of in-hospital outcomes in two years of the pandemic. Changes in circulating variants, improvements in disease management and vaccination are likely to have influenced these results.

Modeling Diversity in Structures of Bacterial Outer Membrane Lipids.

Lipopolysaccharides (LPSs) are vital components of the outer membrane of Gram-negative bacteria, and they act as extremely strong stimulators of innate immunity in diverse eukaryotic species. The primary immunostimulatory center of the LPS molecule is lipid A, a disaccharide-bound lipophilic domain. Considering the broad diversity in bacterial species, there are variations in the lipid A structures and their immunogenic potencies. In this work, we model the lipid A structures of eight commensal or human pathogenic bacterial species: Helicobacter pylori, Porphyromonas gingivalis, Bacteroides fragilis, Bordetella pertussis, Chlamydia trachomatis, Campylobacter jejuni, Neisseria meningitidis, and Salmonella minnesota. The membrane properties of these bacterial species were characterized and compared using molecular simulations. The structure-property relationships that emerge from this lipid A molecular library highlight the roles of acyl chain lengths, number of chains, phosphorylation state, membrane composition, and counterion charge in regulating the phase transition temperature of the membrane, diffusion coefficient of the lipids, and membrane thickness. The molecular and structural insights provided reveal the diversity in bacterial outer membrane lipids and their contribution to human disease and immunity.

The in vitro elution of BMP-7 from demineralized bone matrix.

Demineralized bone matrix (DBM) grafts induce new bone formation by locally releasing matrix-associated growth factors, such as bone morphogenetic proteins (BMPs), to the surrounding tissue after implantation. However, the release kinetics of BMPs from DBM lack characterization. Such information can potentially help to improve processing techniques to maximize graft osteoinductive potential, as well as increase understanding of the osteoinductive process itself. We produced DBM with three particle size ranges from bovine cortical bone, i.e., <106, 106-300, and 300-710 µm and extracted 1.5 g of each size range in 40 ml of Sorensen's buffer at room temperature for up to 168 h. The BMP-7 concentration of the DBM and the buffer were measured at each time point using enzyme-linked immunosorbant assay. Based on measurement of the concentration of BMP-7 in the buffer, the 0-8 h elution rate was high, i.e., 3.3, 2.9, and 2.2 ng BMP-7/g DBM h, and for the 8-168 h interval was much lower, at 0.039, 0.15, and 0.11 ng BMP-7/g DBM h for the three size ranges, respectively. By 168 h, there was no indication that elution was nearing completion. Measurement of the residual BMP-7 remaining in the DBM as a function of time yielded unexpected results, i.e., after the BMP-7 content of the DBM declined for the first 4-6 h, it paradoxically increased for the remaining interval. We propose a two-compartment model to help explain these results in terms of the possible distribution of BMP-7 in bone matrix.