Diagnostic utility of the Alvarado scale in older adults with suspected acute appendicitis.

BACKGROUND: Acute appendicitis remains as a differential diagnosis in older patients with abdominal pain. The Alvarado scale may assist to guide the diagnosis and treatment of this entity. The operative characteristics of the scale are little known in this population. METHOD: We conducted a systematic review of original studies published between 1986 and 2022 evaluating the diagnostic performance of the Alvarado scale in older adults with suspected acute appendicitis. The review was conducted according to the PRISMA statement. The evaluation of the methodological quality of the studies was performed according to the ROBINS-I criteria. RESULTS: Four original studies of retrospective design including 480 patients were identified. The heterogeneity and poor methodological quality limited an aggregate statistical analysis (meta-analysis). The value of the ROC curve of the scale varies between 0.799 and 0.969. From the available studies, the value of the ROC curve is lower in comparison to the RIPASA scale and comparable to the Lintula scale. CONCLUSIONS: The evidence on the diagnostic performance of the Alvarado scale in older adults is limited. The poor methodological quality of the available studies calls for a prudent use of this tool in this population. Our findings offer opportunities for future research.

ANTECEDENTES: La apendicitis aguda es un diagnóstico diferencial en el adulto mayor con dolor abdominal. La escala de Alvarado se utiliza para orientar el diagnóstico y el tratamiento. Las características operativas de la escala son poco conocidas en este grupo de pacientes. MÉTODO: Revisión sistemática de estudios originales publicados entre 1986 y 2022 que evaluaron el rendimiento diagnóstico de la escala de Alvarado en adultos mayores con sospecha de apendicitis aguda, con base en la declaración PRISMA. La evaluación de la calidad metodológica de los estudios se realizó con los criterios ROBINS-I. RESULTADOS: Se identificaron cuatro estudios originales de diseño retrospectivo que incluyen 480 pacientes. La heterogeneidad y la baja calidad metodológica limitaron un análisis estadístico agregado (metaanálisis). El valor de la curva ROC de la escala varía entre 0.799 y 0.969. En los estudios disponibles, el valor de la curva ROC es inferior al de la escala RIPASA y similar al de la escala de Lintula. CONCLUSIONES: La evidencia que sustenta el rendimiento diagnóstico de la escala de Alvarado en los adultos mayores es limitada. La pobre calidad de los estudios disponibles advierte sobre el uso prudente de esta herramienta en este grupo poblacional. Los hallazgos identificados ofrecen oportunidades de investigación futura.

Susceptibilidad a ceftarolina en staphylococcus aureus meticilino resistente / Susceptibility ceftaroline in methicillin-resistant staphylococcus aureus

Ceftarolina es un antibiótico de última generación del subgrupo de las cefalosporinas. Es el primer beta-lactámico comercializado que presenta actividad frente a Staphylococcus aureus resistente a la meticilina (SARM). El objetivo del presente estudio fue describir el patrón de susceptibilidad a ceftarolina en SARM aislados en el Laboratorio de Microbiología del Hospital Vargas de Caracas. Material y métodos: El aislamiento e identificación de las cepas se realizo por pruebas bioquímicas convencionales y las pruebas de susceptibilidad por el método de Difusión en Disco según CLSI 2015. Resultados: Se analizaron un total de 100 cepas SARM, de las cuales el 100% resultó sensible para ceftarolina (≥ 24 mm), con un rango de 26-35 mm, no detectándose ninguna cepa intermedia ni resistente. Conclusión: Ceftarolina muestra una excelente actividad in vitro frente a SARM, por lo que podría presentarse como una alternativa prometedora en el tratamiento de infecciones causadas por este microorganismo.

Ceftaroline is an antibiotic of last generation cephalosporins subgroup. Is the first marketed beta-lactam having activity against Methicillin-resistant S. aureus (MRSA). The aim of this study was to describe the pattern of susceptibility to ceftaroline in MRSA isolated in the Microbiology Laboratory of Hospital Vargas of Caracas. Methods: Isolation and identification of the strains was performed by conventional biochemical tests and susceptibility testing by disk diffusion method according to CLSI 2015. Results: A total of 100 MRSA strains were analyzed, of which 100% he was sensitive to ceftaroline (≥ 24 mm), with a range of 26-35 mm, not detected any intermediate or resistant strain. Conclusion: Ceftaroline shows excellent in vitro activity against MRSA, so it could be presented as a promising alternative in the treatment of infections caused by this organism.

Identifying reactive intermediates in the Ullmann coupling reaction by scanning tunneling microscopy and spectroscopy.

We present an atomic-scale study of substituent effects in the Ullmann coupling reaction on Cu{111} using low-temperature scanning tunneling microscopy and spectroscopy. We have observed fluorophenyl intermediates and phenyl intermediates as well as biphenyl products on Cu{111} after exposure to 4-fluoro-1-bromobenzene (p-FC(6)H(4)Br) and bromobenzene (C(6)H(5)Br), respectively. When p-FC(6)H(4)Br dissociatively chemisorbs at 298 K on Cu{111}, the relatively weakly bound Br dissociates, and fluorophenyl intermediates are formed. These intermediates couple to form 4,4'-difluorobiphenyl and desorb at temperatures below 370 K. However, by cooling the substrate to low temperature (4 K), we have observed unreacted fluorophenyl intermediates distributed randomly on terraces and at step edges of the Cu{111} surface. Alternatively, at similar coverages of C(6)H(5)Br, we have observed biphenyl distributed on terraces and step edges. In each case, Br adatoms were randomly distributed on the surface. Chemical identification of fluorophenyl and phenyl intermediates and biphenyl products was achieved by vibrational spectroscopy via inelastic tunneling spectroscopy. The strongest vibrational mode in the phenyl species disappears when the tilted intermediates couple to form biphenyl products. We infer that the surface normal component of the dipole moment is important in determining the transition strength in inelastic electron tunneling spectroscopy.

Long-range electronic interactions at a high temperature: bromine adatom islands on Cu(111).

Long-range electronic interactions between Br adatom islands, which are formed at approximately 600 K, on Cu(111) are mediated by substrate surface-state electrons at that elevated temperature. Using scanning tunneling microscopy at 4 K, we have quantified nearest neighbor island separations and found favored spacings to be half-multiples of the Fermi wavelength of Cu(111). The strong interaction potential and decay length of the interisland interactions are discussed in terms of the interaction of Br with the substrate surface state.

Dynamics and spectroscopy of hydrogen atoms on Pd{111}.

Chemisorption of hydrogen on Pd{111} is a relatively simple, yet important surface chemical process. By using low-temperature scanning tunneling microscopy, tip-induced motion of adsorbed atomic hydrogen at 4 K has been observed at low coverage. The motion has been ascribed to excitation of vibrational modes that decay into translational modes; vibrational spectroscopy via inelastic electron tunneling corroborates this assignment, and the barrier to hydrogen atom motion has been determined. At higher coverages, tip-induced motion of vacancies in the hydrogen overlayer is observed, and the associated barrier has also been determined.

Observation and manipulation of subsurface hydride in Pd[111] and its effect on surface chemical, physical, and electronic properties.

We report the observation and manipulation of hydrogen atoms beneath the surface of a Pd[111] crystal by using low-temperature scanning tunneling microscopy. These subsurface hydride sites have been postulated to have critical roles in hydrogen storage, metal embrittlement, fuel cells, and catalytic reactions, but they have been neither observed directly nor selectively populated previously. We demonstrate that the subsurface region of Pd can be populated with hydrogen atoms from the bulk by applying voltage pulses from a scanning tunneling microscope tip. This phenomenon is explained with an inelastic excitation mechanism, whereby hydrogen atoms in the bulk are excited by tunneling electrons and are promoted to more stable sites in the subsurface region. We show that this selectively placed subsurface hydride affects the electronic, geometric, and chemical properties of the surface. Specifically, we observed the effects of hydride formation on surface deformation and charge and on adsorbed hydrogen on the surface. Hydrogen segregation and overlayer vacancy ordering on the Pd[111] have been characterized and explained in terms of the surface changes attributable to selective hydrogen occupation of subsurface hydride sites in Pd[111].