Adjustable conduits for guided peripheral nerve regeneration prepared from bi-zonal unidirectional and multidirectional laminar scaffold of type I collagen.

Shortness of donor nerves has led to the development of nerve conduits that connect sectioned peripheral nerve stumps and help to prevent the formation of neuromas. Often, the standard diameters of these devices cannot be adapted at the time of surgery to the diameter of the nerve injured. In this work, scaffolds were developed to form filled nerve conduits with an inner matrix with unidirectional channels covered by a multidirectional pore zone. Collagen type I dispersions (5 mg/g and 8 mg/g) were sequentially frozen using different methods to obtain six laminar scaffolds (P1 to P5) formed by a unidirectional (U) pore/channel zone adjacent to a multidirectional (M) pore zone. The physicochemical and microstructural properties of the scaffolds were determined and compared, as well as their biodegradability, residual glutaraldehyde and cytocompatibility. Also, the Young's modulus of the conduits made by rolling up the bizonal scaffolds from the unidirectional to the multidirectional zone was determined. Based on these comparisons, the proliferation and differentiation of hASC were assessed only in the P3 scaffolds. The cells adhered, aligned in the same direction as the unidirectional porous fibers, proliferated, and differentiated into Schwann-like cells. Adjustable conduits made with the P3 scaffold were implanted in rats 10 mm sciatic nerve lesions to compare their performance with that of autologous sciatic nerve grafted lesions. The in vivo results demonstrated that the tested conduit can be adapted to the diameter of the nerve stumps to guide their growth and promote their regeneration.

A Multi-Institutional Validation of the Prognostic Value of the Neutrophil-to-Lymphocyte Ratio in Patients With Diffuse Large B-Cell Lymphoma: A Study From The Latin American Group of Lymphoproliferative Disorders (GELL).

INTRODUCTION: We aimed at investigating the prognostic role of the neutrophil-to-lymphocyte ratio (NLR) in 2 independent cohorts of Latin American patients with diffuse large B-cell lymphoma (DLBCL) treated with chemoimmunotherapy. PATIENTS AND METHODS: The learning cohort was composed of 274 patients and the validation cohort of 323 patients, for a total of 597 patients. An optimal NLR cutoff ≥ 4 was determined using receiver operating characteristic analysis. RESULTS: In multivariate models, NLR ≥ 4 was independently associated with lower odds for complete response to chemoimmunotherapy in the learning (odds ratio, 0.46; P = .006) and the validation cohort (odds ratio, 0.49; P = .01), and independently associated with worse survival in the learning (hazard ratio, 1.55; P = .04) and the validation cohort (hazard ratio, 1.80; P = .003). CONCLUSIONS: The adverse prognostic value of NLR ≥ 4 was independent of the International Prognostic Index and the National Comprehensive Cancer Network-International Prognostic Index score. Based on the results of this multi-institutional study, NLR ≥ 4 emerges as an adverse prognostic factor in Latin American patients with DLBCL treated with chemoimmunotherapy.

Isolations of yellow fever virus from Haemagogus leucocelaenus in Rio Grande do Sul State, Brazil.

Following howling monkey (Alouatta caraya) deaths and yellow fever (YF) antigen detection by immunohistochemistry in the liver sample of a dead monkey in April and May 2001 in the municipalities of Garruchos and Santo Antônio das Missões, Rio Grande do Sul State, Brazil, epidemiological field investigations were initiated. Two strains of YF virus were isolated in suckling mice from 23 Haemagogus (Conopostegus) leucocelaenus Dyar & Shannon mosquitoes collected from the study sites. The YF virus was isolated from this species in the 1930s in Brazil and in the 1940s in Colombia. No human cases were reported during the current epizootic outbreak. The YF virus isolation and the absence of Hg. (Haemagogus) janthinomys Dyar from the area suggest that Hg. leucocelaenus may be a secondary YF vector and play an important role in the epidemiology of this disease in the Southern Cone.

Comparative study of mandibular linear measurements obtained by cone beam computed tomography and digital calipers.

OBJECTIVES: Cone beam computed tomography (CBCT) is an innovative dental of imaging system characterized by rapid volumetric imaging with patient exposure to a single dose of radiation. The present study was carried out to compare the linear measurements obtained with CBCT and digital caliper in 20 mandibles from human cadavers. STUDY DESIGN: A total of 4800 linear measurements were measured between different mandibular anatomical points with CBCT and digital caliper. The real measurements were defined as those obtained with the digital caliper. Posteriorly, the mandibles were scanned to obtain the CBCT images, with software-based measurements of the distances. RESULTS: The measurements obtained with the digital caliper were greater. The CBCT technique underestimated distances greater than 100 mm. CONCLUSIONS: CBCT allows to obtain linear mandibular anatomical measurements equivalent to those obtained with digital caliper. The differences existing between both methods were clinically acceptable. Key words:Computed tomography, cone beam CT, accuracy, reliability, digital caliper.

Genome Sequence of Streptomyces olindensis DAUFPE 5622, Producer of the Antitumoral Anthracycline Cosmomycin D.

Streptomyces olindensis DAUFPE 5622, which was isolated from a Brazilian soil sample, produces the antitumor anthracycline cosmomycin D. The genome sequence is 9.4 Mb in length, with a G+C content of 71%. Thirty-four putative secondary metabolite biosynthetic gene clusters were identified, including the cosmomycin D cluster.