Nerve gaps repaired with acellular nerve allografts recellularized with Schwann-like cells: Preclinical trial.

BACKGROUND: Acellular nerve allografts (ANA) recellularized with mesenchymal stem cells (MSC) or Schwann cells (SC) are, at present, a therapeutic option for peripheral nerve injuries (PNI). This study aimed to evaluate the regenerative and functional capacity of a recellularized allograft (RA) compared with autograft nerve reconstruction in PNI. METHODS: Fourteen ovines were randomly included in two groups (n=7). A peroneal nerve gap 30 mm in length was excised, and nerve repair was performed by the transplantation of either an autograft or a recellularized allograft with SC-like cells. Evaluations included a histomorphological analysis of the ANA, MSC pre differentiated into SC-like cells, at one year follow-up functional limb recovery (support and gait), and nerve regeneration using neurophysiological tests and histomorphometric analysis. All evaluations were compared with the contralateral hindlimb as the control. RESULTS: The nerve allograft was successfully decellularized and more than 70% of MSC were pre differentiated into SC-like cells. Functional assessment in both treated groups improved similarly over time (p <0.05). Neurophysiological results (latency, amplitude, and conduction velocity) also improved in both treated groups at twelve months. Histological results demonstrated a less organized arrangement of nerve fibers (p <0.05) with an active remyelination process (p <0.05) in both treated groups compared with controls at twelve months. CONCLUSIONS: ANA recellularized with SC-like cells proved to be a successful treatment for nerve gaps. Motor recovery and nerve regeneration were satisfactorily achieved in both graft groups compared with their contralateral nontreated nerves. This approach could be useful for the clinical therapy of PNI.

A modified chemical protocol of decellularization of rat sciatic nerve and its recellularization with mesenchymal differentiated schwann-like cells: morphological and functional assessments.

The functional reconstruction of large neural defects usually requires the use of peripheral nerve autografts, though these have certain limitations. As a result, interest in new alternatives for autograft development has risen. The acellular peripheral nerve graft is an alternative for peripheral nerve injury repair, but to date there is not a standardized chemical decellularization method widely accepted. The objective of this study was to propose a modified chemical protocol of decellularization of rat sciatic nerve and its recellularization in vitro with mesenchimal differentiated Schwann-like cells. After the transplantation, an evaluation of its regeneration was performed using morphological and functional tests. The study consisted of two phases; in phase 1, different concentrations and times of exposure of rat sciatic nerves to detergents were tested, to establish a modified chemical protocol for nerve decellularization. The chemical treatment with 3% triton X-100 and 4% sodium deoxycholate for 15 days allowed a complete decellularization whilst conserving the extracellular matrix of the harvested nerve. In phase 2, the decellularized and recellularized alografts were compared against autografts. The morphological analysis showed a higher positivity to specific myelin antibodies in the recellularized group compared to the autograft. There were no differences in this parameter between the control limb and the experimental limb (recellularized group). The functional analysis showed no statistical differences at week 15 in the Sciatic Function Index in the autograft group vs the other groups. This study sets the morphological and functional bases for posterior studies about nerve defects regeneration in humans.

[The validation of a portable 3-channel recording system (Oxyflow, Edentec) for the diagnosis of the sleep apnea syndrome]. / Validación de un sistema portátil de registro de tres canales (Oxyflow, Edentec) para el diagnóstico del síndrome de apnea del sueño.

OBJECTIVE: To evaluate the usefulness of a portable recording device (Oxyflow, EdenTec) to measure oronasal airflow, oxygen saturation and arterial pulse for diagnosing sleep apnea syndrome (SAS) using conventional polysomnography as the gold standard. METHODS: Sixty-two subjects suspected of having SAS were studied prospectively by simultaneously recording conventional polysomnography and Oxyflow data in the sleep laboratory. Two different investigators, blinded to each other's findings, interpreted the data from each method. The apnea-hypopnea index (AHI) cut-off points used were?? 10, 15 and 30. The sensitivity, specificity, positive predictive value and negative predictive value of the Oxyflow indices for each AHI cut-off point were calculated. Both computer-generated and manually collected data from the Oxyflow device were analyzed. Manual readings were recorded by two independent investigators and interobserver agreement was calculated. The usefulness of both automatic and manual analyses for SAS diagnosis was assessed using receiver operating characteristic curves (ROC). RESULTS: Fifty-eight (93.5%) men and 4 (6.5%) women with a mean age (+/- SD) of 53 +/- 11 years (29-73) were enrolled. An AHI > or = 10 was observed in 58% of the patients and mean AHI was 25 +/- 28 (0-125). The index of respiratory disturbance per hour of analysis with desaturation events > or = 4% (RDI4%) was the parameter with the largest area under the ROC curve (0.90 for AHI > or = 10; 0.94 for AHI > or = 15 and 0.96 for AHI > or 30). Manual reading was practical and reproducible (agreement 0.93, kappa coefficient 0.82) but its efficiency was no greater than that of automatic analysis. CONCLUSIONS: The Oxyflow device may be a useful diagnostic tool for SAS. Its portability and simplicity makes it potentially useful for in-home studies.

Validación de un sistema portátil de registro de tres canales (Oxyflow, Edentec) para el diagnóstico del síndrome de apnea del sueño / Validation of a portable three-channel recording system (Oxyflow, EdenTec) for diagnosing sleep apnea syndrome

Objetivo: Evaluar la utilidad de un sistema de registro portátil (Oxyflow, Edentec), que mide flujo nasobucal, saturación de oxígeno y pulso arterial, para el diagnóstico del síndrome de apnea del sueño (SAS), utilizando la polisomnografía convencional como patrón de referencia. Métodos: Se estudiaron prospectivamente 62 sujetos con sospecha de SAS, realizándose simultáneamente polisomnografía convencional y registro con Oxyflow en el laboratorio de sueño. Dos investigadores diferentes interpretaron los registros de cada uno de los métodos, a ciegas respecto al otro. Se utilizaron diferentes puntos de corte para el índice de apneas-hipopneas (IAH) (>= 10, 15 y 30). Se calcularon la sensibilidad, especificidad, valor predictivo positivo y valor predicto negativo de los índices del Oxyflow para cada punto de corte del IAH. Al analizar los registros del Oxyflow, se emplearon tanto datos generados por el software incluido en el sistema como los obtenidos con una interpretación manual de los mismos. El análisis manual fue realizado por dos investigadores independientes, y se calculó la concordancia interobservador. La utilidad del análisis manual y el automático para el diagnóstico del SAS fue evaluado usando curvas receptor-operador (ROC). Resultados: Se incluyeron en el estudio 58 varones (93,5 por ciento) y 4 mujeres (6,5 por ciento), con una edad media (ñ DE) de 53 ñ 11 años (29-73). El 58 por ciento de los pacientes tenían un IAH >= 10 (IAH medio: 25 ñ 28 [0-125]). De todos los parámetros analizados, el RDI4 por ciento (índice de episodios respiratorios por hora de registro, con desaturaciones >= 4 por ciento) presentó el mayor área bajo la curva ROC (0,90 para IAH >= 10; 0,94 para IAH >= 15 y 0,96 para IAH >= 30). El análisis manual fue factible y reproducible (concordancia: 0,93; coeficiente kappa: 0,82), pero su eficiencia no fue mayor que la del análisis automático. Conclusiones: El sistema Oxyflow puede ser una herramienta útil para el diagnóstico del SAS. Su portabilidad y simplicidad lo hacen potencialmente útil para estudios domiciliarios. (AU)

[Varicella pneumonia in the previously healthy adult]. / Neumonía varicelosa en el adulto previamente sano.

Varicella (chickenpox) is a contagious, self-limited, usually benign disease common in childhood but uncommon in adulthood. Pneumonia is the most frequent complication of the disease in adults. We retrospectively review 7 cases of varicella pneumonia in previously healthy adults diagnosed in our hospital between 1992 and 1996. All of them were treated with intravenous acyclovir with good therapeutic response save for a patient who developed respiratory insufficiency and died 8 days after his admission. Smoking was the only risk factor detected. Clinical features of our patients are described and the need of an early diagnosis and treatment of varicella pneumonia is emphasized.

Neumonía varicelosa en el adulto previamente sano / Varicella penumonia in the previously healthy adult

La varicela es una enfermedad contagiosa autolimitada y generalmente benigna propia de la infancia, y poco común en el adulto. La neumonía es la complicación mas frecuente de la enfermedad en el adulto. Revisamos retrospectivamente 7 casos de neumonía varicelosa en adultos previamente sanos diagnosticados en nuestro hospital entre 1992 y 1996. Todos ellos fueron tratados con Aciclovir endovenoso, presentando buena evolución salvo un paciente que desarrolló insuficiencia respiratoria y falleció 8 días tras su ingreso. El tabaco fue el único factor de riesgo detectado. Presentamos las particularidades clínicas de nuestros pacientes y destacamos la necesidad de un diagnóstico y tratamiento precoz de la neumonía por varicela (AU)

[Hepatic hydrothorax without ascites: presentation of a case and review of the literature]. / Hidrotórax hepático sin ascitis: presentación de un caso y revisión de la literatura.

Hepatic Hydrothorax is a well known complication in patients with cirrhosis and secondary ascites. It is unusual in the absence of ascites, with few cases reported in the literature. We describe a patient with Hepatic Hydrothorax without ascites and review the literature.

[Spontaneous pneumothorax associated with human immunodeficiency virus (HIV) infection]. / Neumotórax espontáneo asociado a la infección por el virus de la inmunodeficiencia humana (VIH).

Spontaneous pneumothorax is a relatively frequent complication of human immunodeficiency virus (HIV) infection. Seven hundred sixty-five HIV-infected inpatients were treated at Marques de Valdecilla University Hospital between 1990 and 1996. Spontaneous pneumothorax developed in 9 patients. Pneumocystis carinii pneumonia was diagnosed in 6 patients (66%), either before or simultaneous to the appearance of pneumothorax. Pneumothorax was related to active or old tuberculosis infection in 3 patients (33%). Prophylactic therapy with nebulized pentamidine was used in 55% of the patients. Successful initial control of pneumothorax was achieved with simple drains in 58% of the episodes, although the recurrence rate was 71%. Pleurodesis with talcum with a chest tube was used successfully in 3 patients, in 2 because of sings of persistent air leakage uncorrected by simple drainage. Pleurodesis initially failed but later controlled pneumothorax the second time it was used. The mortality rate in this series was 66%, with a mean survival time of 55.6 days. We conclude that spontaneous pneumothorax is associated with poor prognosis in HIV infected patients. Prior or concurrent P. carinni pneumonia or tuberculosis were the etiologic factors identified in our patients. A simple pleural drain was associated with a high rate of recurrence, such that pleurodesis seems warranted in all patients.

[Small cell lung carcinoma in the form of multiple lung nodules]. / Carcinoma pulmonar de células pequeñas en forma de nódulos pulmonares múltiples.

Small cell carcinoma of the lung occasionally presents as a single pulmonary nodule, but its expression in the form of multiple pulmonary nodules has not been reported in the literature. We describe a single case of small cell carcinoma of the lung presenting as multiple pulmonary nodules that seems to have been cured by chemotherapy.

[Stages of the historic evolution of the antituberculosis campaign in Cuba]. / Recuento de las etapas de evolución histórica de la lucha antituberculosa en Cuba.

A brief account is provided on the main characteristics of the stages in the historical evolution of struggle against tuberculosis in Cuba. The foundations and the steps taken in tuberculosis control are noted. A synthesis of therapeutic schemes used in the last 20 years is provided and the tendency of notification of new cases in 1979-1988 is discussed. During that ten-year period there was a 38.8% reduction.