Reparación de las lesiones crónicas del manguito rotador mediante diferentes compuestos / Repair of rotator cuff injuries using different composites

Objetivo. La reparación del manguito rotador se acompaña de una elevada tasa de rerrotura. Nuestro objetivo es determinar si el empleo de rhBMP-2 vehiculizada en un transportador híbrido mejora el proceso de reparación en lesiones crónicas del manguito. Material y métodos. Estudio experimental en 62 ratas. A las 4 semanas de la lesión se llevó a cabo una sutura transósea y la asignación aleatoria a uno de los 5 grupos de estudio: 1) grupo control: solo sutura; 2) grupo doble-control: se aplicó además un transportador de alginato-quitina; 3) grupo control-alginato: se añadió rhBMP-2 al alginato; 4) grupo control-quitina: se añadió rhBMP-2 a la quitina, y 5) grupo doble-muestra: se añadió rhBMP-2 a ambos componentes. A los 4 meses se evaluaron los resultados mediante estudios biomecánicos e histológicos. Resultados. En todos los casos se observó una brecha osteotendinosa macroscópicamente a las 4 semanas. La tasa de rerrotura fue del 7,5%, ocurriendo el 20% de ellas en el grupo control-alginato. En la evaluación histológica los mejores resultados se obtuvieron en el grupo doble muestra: 4,5 (3,3-5). La carga máxima soportada fue mayor en el grupo doble muestra 62,9N (59,8-69,4) presentando además una menor rigidez 12,7 (9,7-15,9). Conclusiones. El empleo de la rhBMP-2 vehiculizada en un transportador híbrido de alginato-quitina parece mejorar las características histológicas de la reparación e incrementar las propiedades biomecánicas del tendón en el contexto de una lesión crónica del manguito rotador (AU)

Aim. Rotator cuff repairs have shown a high level of re-ruptures. It is hypothesised that the use of rhBMP-2 in a carrier could improve the biomechanical and histological properties of the repair. Material and methods. Controlled experimental study conducted on 40 rats with section and repair of the supraspinatus tendon and randomisation to one of five groups: Group 1 (control) only suture; Group 2 (double control), suture and alginate-chitin carrier; Group 3 (alginate-control), the rhBMP-2 was added to the alginate; Group 4 (chitin-control) application of the rhBMP-2 to the chitin, and Group 5 (double sample): The two components of the carrier (alginate and chitin) have rhBMP-2. A biomechanical and histological analysis was performed at 4 weeks. Results. A gap was observed in all cases 4 weeks after supraspinatus detachment. The re-rupture rate was 7.5%, with 20% of them in the control-alginate Group. Histologically the best results were obtained in the double sample group: 4.5 (3.3-5.0). Double sample were also able to support higher loads to failure: 62.9N (59.8 to 69.4) with lower rigidity 12.7 (9.7 to 15.9). Conclusions. The use of alginate-chitin carrier with rhBMP-2 improves the biomechanical and histological properties of the repair site in a chronic rotator cuff tear (AU)

Repair of rotator cuff injuries using different composites. / Reparación de las lesiones crónicas del manguito rotador mediante diferentes compuestos.

AIM: Rotator cuff repairs have shown a high level of re-ruptures. It is hypothesised that the use of rhBMP-2 in a carrier could improve the biomechanical and histological properties of the repair. MATERIAL AND METHODS: Controlled experimental study conducted on 40 rats with section and repair of the supraspinatus tendon and randomisation to one of five groups: Group 1 (control) only suture; Group 2 (double control), suture and alginate-chitin carrier; Group 3 (alginate-control), the rhBMP-2 was added to the alginate; Group 4 (chitin-control) application of the rhBMP-2 to the chitin, and Group 5 (double sample): The two components of the carrier (alginate and chitin) have rhBMP-2. A biomechanical and histological analysis was performed at 4 weeks. RESULTS: A gap was observed in all cases 4 weeks after supraspinatus detachment. The re-rupture rate was 7.5%, with 20% of them in the control-alginate Group. Histologically the best results were obtained in the double sample group: 4.5 (3.3-5.0). Double sample were also able to support higher loads to failure: 62.9N (59.8 to 69.4) with lower rigidity 12.7 (9.7 to 15.9). CONCLUSIONS: The use of alginate-chitin carrier with rhBMP-2 improves the biomechanical and histological properties of the repair site in a chronic rotator cuff tear.

Label-free magnetic resonance imaging to locate live cells in three-dimensional porous scaffolds.

Porous scaffolds are widely tested materials used for various purposes in tissue engineering. A critical feature of a porous scaffold is its ability to allow cell migration and growth on its inner surface. Up to now, there has not been a method to locate live cells deep inside a material, or in an entire structure, using real-time imaging and a non-destructive technique. Herein, we seek to demonstrate the feasibility of the magnetic resonance imaging (MRI) technique as a method to detect and locate in vitro non-labelled live cells in an entire porous material. Our results show that the use of optimized MRI parameters (4.7 T; repetition time = 3000 ms; echo time = 20 ms; resolution 39 × 39 µm) makes it possible to obtain images of the scaffold structure and to locate live non-labelled cells in the entire material, with a signal intensity higher than that obtained in the culture medium. In the current study, cells are visualized and located in different kinds of porous scaffolds. Moreover, further development of this MRI method might be useful in several three-dimensional biomaterial tests such as cell distribution studies, routine qualitative testing methods and in situ monitoring of cells inside scaffolds.

Vigilancia compartida: enfermedad meningocócica vs gripe / Shared surveillance: meningococcal disease vs influenza

Objetivo: Analizar la asociación entre el comportamiento de la enfermedad meningocócica y la gripe utilizando datos poblacionales de España, para el periodo de 1964 a 1997.Métodos: Estudio ecológico de la incidencia de enfermedad meningocócica y gripe en España para los años 1964 a 1997, ambos inclusive. Se han utilizado los datos semanales de ambas enfermedades procedentes del Sistema de Enfermedades de Declaración Obligatoria (EDO). La componente determinista de las series de enfermedad meningocócica y gripe se estudió mediante el análisis espectral basado en la Transformada Rápida de Fourier y la parte no determinista mediante la modelización ARIMA. Se utilizó la técnica de Box-Jenkins para el preblanqueo de las series, estableciéndose posteriormente funciones de correlación cruzada entre los residuales para detectar la existencia de correlaciones significativas entre las series de enfermedad meningocócica y gripe. Resultados: En el periodo de 1964 a 1997, la semana que, en término medio, ha presentado el mayor número de casos de la temporada ha sido la semana 7 para la enfermedad meningocócica y la 6 para la gripe. El análisis espectral de las series de gripe y enfermedad meningocócica muestra una clara periodicidad anual para ambas series, así como una periodicidad próxima a los 11 años para la enfermedad meningocócica y para periodos superiores a 10 años para la gripe. Si se establecen funciones de correlación cruzada una vez preblanqueadas las series se obtienen correlaciones positivas en los retrasos 0, 1, 2 y 3. La modelización multivariada de enfermedad meningocócica introduciendo la gripe como variable exógena corrobora lo anteriormente expuesto teniendo significación estadística la relación establecida entre ambas en la misma semana y desfasada 3 semanas. Conclusiones: Mediante una metodología no empleada con anterioridad para abordar este tema y utilizando datos poblacionales del conjunto de un país a lo largo de un periodo de tiempo prolongado (que incluye varias ondas epidémicas) se ha corroborado la existencia de una asociación entre enfermedad meningocócica y gripe. Se plantea la necesidad de vigilar ambos procesos de forma interrelacionada (AU)

[Evolution of meningococcal disease in the community of Madrid. Effectiveness of antimeningococcal A+C vaccination]. / Evolución de la enfermedad meningocócica en la Comunidad de Madrid. Efectividad de la vacunación antimeningocócica A + C.

BACKGROUND: In 1997 (between 22 September and 14 November) an A + C meningococcal mass vaccination campaign was carried out in Madrid, targeting the age group of from 18 months to 19 years of age, in the face of an increase in the number of cases of meningococcal disease caused by serogroup C occurring in the 1996-97 season. This study forms a part of the impact assessment of that campaign. METHODS: The evolution of the meningococcal disease, by means of the comparison of rates of incidence; and the efficacy of the vaccination campaign was determined after one year (1997-98 season) and after two years (1997-98 and 1998-99 seasons) of monitoring. The vaccine efficacy has been calculated as [1-(Incidence rate in vaccinated/Incidence rate in unvaccinated)]* 100. RESULTS: A significant drop was registered in the incidence of serogroup C meningococcal disease on comparing the 1997-98 and 1998-99 seasons with the epidemic season (1996-97). The vaccine efficacy after two years of monitoring subsequent to the vaccination campaign was 76.9% for the global population between 18 months and 19 years of age and 88.5% in the group of vaccinated individuals between 15 and 19 years of age. CONCLUSIONS: The vaccine efficacy obtained is compatible with that described in the relevant literature. The significant reduction in the incidence of meningococcal disease caused by serogroup C was due to the vaccine efficacy obtained.

[Shared surveillance: meningococcal disease vs influenza]. / Vigilancia compartida: enfermedad meningocócica vs gripe.

OBJECTIVE: To analyse the association between the behavior of meningococcal disease and influenza, using for this purpose population statistics for Spain for the period of 1964 to 1997. METHODS: Ecological study of the incidence of meningococcal disease and influenza in Spain from 1964 to 1997, inclusive. The study used weekly statistical data for these diseases supplied by the Compulsory Disease Reporting System (Enfermedades de Declaración Obligatoria, EDO). The deterministic component of the meningococcal disease and influenza series was studied by means of spectral analysis based on the Fast Fourier Transformation, and the non-deterministic component was studied using the ARIMA model. The Box-Jenkins method was used for pre-bleaching the series, and a cross-correlation was subsequently established between the residuals in order to detect the presence of any significant correlations between the meningococcal disease and influenza series. RESULTS: During the period from 1964 to 1997, the week that showed, on average, the greatest number of cases for the season was week 7 in the case of meningococcal disease and week 6 in the case of influenza. Spectral analysis of the meningococcal disease and influenza series clearly demonstrated the annual periodicity of both series, and periodicity of nearly 11 years for meningococcal disease and slightly over 10 years for influenza. When cross-correlation is established after prebleaching the series, positive correlations are obtained in the results of lags 0, 1, 2, and 3. Introducing influenza as an exogenous variable in the multivariate model of meningococcal disease corroborates these results. There was a statistically significant relationship between the two processes during the same week and with a three-week lapse. CONCLUSIONS: By means of a methodology not previously applied to this subject, and by the use of prolonged time-span, country-comprehensive population statistics (which includes several epidemics waves), an association was shown to exist between meningococcal disease and influenza. This suggests the need for the surveillance of the two processes in an interrelated manner.