Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)-based scaffolds for tissue engineering

Development and selection of an ideal scaffold is of importance for tissue engineering. Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) is a biocompatible bioresorbable copolymer that belongs to the polyhydroxyalkanoate family. Because of its good biocompatibility, PHBHHx has been widely used as a cell scaffold for tissue engineering. This review focuses on the utilization of PHBHHx-based scaffolds in tissue engineering. Advances in the preparation, modification, and application of PHBHHx scaffolds are discussed.

Expression of non-neuronal cholinergic system in maxilla of rat in vivo

BACKGROUND: Acetylcholine (ACh) is known to be a key neurotransmitter in the central and peripheral nervous systems, which is also produced in a variety of non-neuronal tissues and cell. The existence of ACh in maxilla in vivo and potential regulation role for osteogenesis need further study. RESULTS: Components of the cholinergic system (ACh, esterase, choline acetyltransferase, high-affinity choline uptake, n- and mAChRs) were determined in maxilla of rat in vivo, by means of Real-Time PCR and immunohistochemistry. Results showed RNA for CarAT, carnitine/acylcarnitine translocase member 20 (Slc25a20), VAChT, OCTN2, OCT1, OCT3, organic cation transporter member 4 (Slc22a4), AChE, BChE, nAChR subunits α1, α2, α3, α5, α7, α10, ß1, ß2, ß4, γ and mAChR subunits M1, M2, M3, M4, M5 were detected in rat's maxilla. RNA of VAChT, AChE, nAChR subunits α2, ß1, ß4 and mAChR subunits M4 had abundant expression (2(-ΔCt) > 0.03). Immunohistochemical staining was conducted for ACh, VAChT, nAChRα7 and AChE. ACh was expressed in mesenchymal cells, chondroblast, bone and cartilage matrix and bone marrow cells, The VAChT expression was very extensively while ACh receptor α7 was strongly expressed in newly formed bone matrix of endochondral and bone marrow ossification, AchE was found only in mesenchymal stem cells, cartilage and bone marrow cells. CONCLUSIONS: ACh might exert its effect on the endochondral and bone marrow ossification, and bone matrix mineralization in maxilla.

Costicartilage analysis inspection technology in the application of forensic medicine / 法医学杂志

The traditional costicartilage analysis inspection is limited to morphological inspection. In recent years, with the development of forensic radiology and molecular genetics, the costicartilage analysis inspection technology has been further enriched and developed. At present, the costicartilage analysis inspection technology have been able to be used in the practice of forensic medicine. This paper reviews the research advances about the costicartilage analysis inspection technology in the identification of human gender, age and so on in order to provide the references for forensic appraisers.

Tragal cartilage tympanoplasty for management of atelectatic tympanic membrane: palisade versus cross hatched cartilage

The purpose of this study was to analyze the outcomes of two cartilage tympanoplasty techniques for management of posterosuperior pars tensa atelectasis to achieve an acceptable compromise between sufficient mechanical stability and acceptable acoustic transfer characteristics of the cartilage graft. A prospective clinical study included patients who underwent cartilage tympanoplasty between April 2003 and March 2006. The study included 42 [patients with grade 3 posterosuperior pars tensa atelectasis, twenty males and twenty two females, their ages ranged between 22 and 48 years [mean age 32 +/ 3.6]. Eight patients had bilateral ear diseases operated separately with 6 months interval 50 cartilage tympanoplasties were performed. Of these procedures, 24 ears were grafted with tragal cartilage palisades [group A] and 26 ears [group B] were grafted with tragal cross hatched cartilage [modified cartilage plate]. Hearing results were reported using a four-frequency [0.5, 1, 2, 4 kHz] pure-tone average air-bone - gap [PTA-ABG]. Patients were follow up for 12 months through regular visits [weekly for the first month then monthly till the end of follow-up period]. Data were analyzed using Wilcoxon analysis for unpaired data and Chi-square [X[2]] test for comparisons of non-parametric results. The criteria for success were complete healing, prevention of further retraction in posterosuperior quadrant, and air-bone gap less than 20 dB. In palisade group [group A], 2 patients developed posterosuperior retraction [8%] and 2 patients developed anterior retraction. Compared with the outcomes of cross hatched cartilage tympanoplasty group [group B] in which 2 patients developed posterosuperior retraction and three patients develop anterior retraction, there was no significant difference. In group A, the hearing threshold improved in all patients except the two with recurrent retraction. The air- bone gap significantly decreased at all frequencies with significant decrease of mean PTA-ABG from 19.9 +/- 3.4 dB preoperative to 16.7 +/- 3 dB postoperative. Also, the cross hatched cartilage tympanoplasty had a significant decreasing effect on air-bone gap from 29.9 +/- 3.3 dB preoperativeiy to 13.4 +/- 2.6 dB postoperative. Comparing the postoperative hearing threshold of group [A] and group [B] revealed significant better acoustic outcome of cross hatched tympanoplasty technique. The cross hatched tragal cartilage tympanoplasty is a promising method for management of grade 3 postersuperior pars tensa retraction with good stability and acoustic outcomes

Tabla de valoración de la maduración esquelética según el signo de risser en individuos sanos de 10 a 20 años de edad / Table of valuation of the skeletal maturation according to the sign of risser in healthy individuals of 10 to 20 years of age

Se realizó un estudio clínico-radiográfico, transversal, comparativo, en 300 individuos sanos comprendidos entre de 10 y 20 años, de los dos sexos, del Instituto Fiscal de Educación Integrado "José Martí" y del Colegio Nacional Santiago de Guayaquil de la ciudad de Quito, entre enero y diciembre de 1996, con el propósito de elaborar una tabla de valoración ósea nacional, usando como referencia el signo de RISSER, (evolución de los centros secundarios de osificación de la cresta ilíaca). A cada uno de los sujetos de nuestro estudio se le realizó una radiografía anteroposterior de pelvis, y se analizaron las siguientes variables: peso, talla, edad, sexo y perímetro braquia para valorar el estado nutricional. Los sujetos fueron subdivididos en dos grupos de acuerdo al sexo: hombres y mujeres, y de acuerdo a la edad en subgrupos de 10 a 20 años con intervalos de 1 año. Se encontró que la maduración ósea según el signo de Risser se inicia más temprano en las mujeres. En los hombres existe una relación directa (correlación positiva r = 0.50) entre el aparecimiento del signo de Risser con las siguientes variables: perímetro braquial a los 16 años y con el peso y la talla a los 13 años; en las mujeres con talla a los 10 años y peso y perímetro braquial a los 13 años. En los hombres el signo de RISSER se inicia a los 13 años en un 6.67 por ciento y a los 19 años únicamente han completado la osificación el 46.67 por ciento, en las mujeres el 6.67 por ciento presentaron un RISSER 1 a los 10 años y completaron su osificación el 54.55 por ciento a los 19 años. Ninguno de los grupos presentó signos de desnutrición (Indice de Quetelet 0.17-0.22). Estos valores comparados con los de la literatura, nos indican que el desarrollo óseo en hombres y mujeres de Quito es notoriamente más tardía debido probablemente a factores nutricionales, climáticos, genéticos y étnicos...