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1.
Bone augmentation procedures rely on osteogenic/osteoconductive properties of bone graft material (BGM). A further improvement is represented by use of autologous bone marrow stromal cells (BMSC), expanded in vitro and seeded on BGM before implantation in the bone defect. The effect of different BGMs on BMSC osteogenic differentiation was evaluated. BMSC were cultured in vitro in the presence of different BGM (natural, synthetic, and mixed origins). Cellular morphology was analyzed with scanning electron microscopy. The capability of BMSC to differentiate was determined in vitro by alkaline phosphatase gene expression and enzyme activity at different time points (7, 14, and 28 days) and in vivo by ectopic bone formation of implanted tissue constructs in an immunodeficient murine model. BGM supports the cell adhesion and osteogenic differentiation of BMSC developing a useful tool in the bone tissue engineering.  相似文献   
2.
Chronic skin ulcers, consequence of diabetes and other pathological conditions, heavily compromise the patient life quality and represent a high and constantly growing cost for National Health Services. Autologous platelet‐rich plasma (PRP), has been proposed to treat these lesions. The absence of guidelines for the PRP production and the need of a fresh preparation for each treatment lead us to develop a protocol for the production of an allogenic PRP‐based bioactive membrane (BAM), standardized for platelet concentration and growth factor release. This work compares BAMs obtained starting from two different platelet concentrations. There was no direct correlation between the amount of growth factors released by BAM in vitro and the initial platelet count. However, different release kinetics were noticed for different growth factors, suggesting that they were differently retained by the two BAMs. The angiogenic potential of both BAMs was determined by Luminex Angiogenesis Assay. The biological activity of the factors released by the two BAMs was confirmed by cell proliferation and migration. A diabetic mouse chronic ulcer model was used to define the best PRP therapeutic dose in vivo. Both BAMs induced wound healing by increasing the thickness of the regenerated epidermis and the vessel number. However, a too high platelet concentration resulted in a slowdown of the membrane resorption that interfered with the skin healing. Overall, the results indicate that the BAMs could represent a natural and effective wound healing tool for the treatment of skin ulcers. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   
3.
Maternal serum alpha-fetoprotein and fetal autosomal trisomies   总被引:4,自引:0,他引:4  
Maternal serum alpha-fetoprotein values in 61 patients with fetal autosomal trisomies diagnosed at 6581 genetic amniocenteses were significantly lower than those in an equal number of matched control subjects. The genetic risk of fetal autosomal trisomies for women less than age 35 offered amniocentesis with maternal serum alpha-fetoprotein values less than 0.5 multiples of the median is in the same range as that currently accepted for advanced maternal age. Maternal serum alpha-fetoprotein screening for autosomal trisomies (mainly Down syndrome) is feasible.  相似文献   
4.
In order to study male hypergonadotropic hypogonadism as completely as possible, and to evaluate its possible effects on muscle atrophy and sexuality, RIA or IRMA methods were used to measure the levels of luteinizing hormone (LH), follicle stimulating hormone (FSH), prolactin, total (T) and free (FT) testosterone, estradiol (E), dihydrotestosterone (DHT), sex hormone binding globulin (SHBG), androstenedione (A) and 17-OH-progesterone (17-OH-P) in 29 patients with myotonic dystrophy (MD). The mean hormonal levels ±SD were: LH 8.0±4.4 mIU/ml, FSH 17.4±11.5 mIU/ml, A 200±130 ng/dl (all higher than in controls); T 406±290 ng/dl, FT 22.7±7.0 pg/ml, DHT 55.5±29.7 ng/ml (all lower than in controls). The low FT and DHT levels (never previously studied in MD) confirm the androgenic deficiency. The high androstenedione levels and low testosterone concentrations suggest defective enzyme 17-dehydrogenase. The duration of the disease correlated with both testosterone (r=–0.56) and FT levels (r=–0.59), showing that hypogonadism tends to worsen progressively. When the patients were divided into three groups on the basis of the severity of muscle involvement (A, B and C), LH and FSH levels were higher in group C (more severe disease) than in group A, respectively 9.3±4.7 and 20.6±12.3 mIU/ml versus 4.8±0.9 and 8.4±3.8, p<0.03; T levels were lower in group C than in group A, 337.3±263.4 ng/dl versus 649.7±320.3 (p<0.03); however, there was no significant difference in the FT levels of the three groups, which may imply that hypogonadism is unlikely to have a direct effect on muscle atrophy. About 25% of our patients were impotent; these subjects had higher LH and FSH (p<0.001) and lower FT levels than the patients who were not impotent (p<0.03). However, hypogonadism may not be the only cause of impotence as all of the impotent patients belonged to group C and had a very high (CTG)n triplet expansion. We hypothesise that hypogonadism and sexual impairment could be partially due to a muscle cell alteration: i.e. a dysfunction of both the testicular peritubular myoid cells and of the corpus cavernosum smooth muscle.The financial support of Theleton (Grant No. 640) is gratefully acknowledged.  相似文献   
5.
We have analysed the [AGC] expansion in leucocytes, muscle and sperm from 17 individuals affected by myotonic dystrophy (DM). Skeletal muscle showed a larger repeat number than leucocytes in the same patient. A similar degree of expansion was detected in differently affected muscles of a single patient. The germline mutation ( 350 repeats) was expanded in somatic cells of the progeny in all patients examined. Our results provide evidence of an early postzygotic instability of the [AGC] repeat in DM.  相似文献   
6.
The present work investigates the sex hormone profiles in 50 male patients with liver cirrhosis of different etiology according to the degree of liver dysfunction. The only hormonal impairment in well-compensated cirrhotics (group A) was an increase in mean serum concentrations of estrone, androstenedione, and sex hormone binding globulin. In decompensated cirrhotic patients with ascites (group B), low mean levels of total and free testosterone were found along with normal gonadotropins mean levels. Estrone and androstenedione levels were still elevated, whereas sex hormone binding globulin levels were not different from controls. In decompensated cirrhotics patients with encephalopathy (group C), total and free testosterone mean levels were lower than in group B, and LH mean levels were elevated; estrone levels were markedly high, but androstenedione levels were subnormal; sex hormone binding globulin concentrations were again not different from controls. The few patients with high prolactin levels belonged primarily to this group. Estradiol mean levels were not significantly elevated in any of the groups. It is concluded that the various hormonal patterns of gonadal failure and of the impairment of steroid metabolism and transport, observed in cirrhosis, can be attributed to the degree of liver dysfunction.  相似文献   
7.
The objective of this study was to investigate the pattern of expression and the localization of Notch-1, Notch-4 and Jagged-1 in physiological and pathological human endometrium and to evaluate the expression levels of two major regulators of the G1 checkpoint, namely cyclin D1 and p21. Sixty samples of physiological endometrium and 60 samples of pathological endometrium were used for the study. Evaluation of the expression level and the distribution of Notch pathway members and cell-cycle proteins was performed by immunohistochemistry. In the physiological endometrium we observed an increase of Notch-1 and Jagged-1 from proliferative to secretory phase and an opposite trend for Notch-4. In menopause, the level of expression of all three members of the Notch pathway decreased. We also observed a cyclin D1 increase from proliferative to secretory phase. By contrast, p21 showed a slight increase from proliferative to secretory phase. In the pathological endometrium, we observed an increase of Notch-1 expression from polyps to carcinoma and decrease for Notch-4 and Jagged-1. Moreover, we observed a higher expression of cyclin D1 in all the endometrial pathologies. By contrast, the expression level of p21 slightly increased from polyps to carcinoma. We concluded that in human endometrium Notch-4 seems to be more involved in controlling proliferation, whereas Notch-1 seems to be more involved in differentiation programming. Deregulation of these functions may induce the onset of several endometrial pathologies from polyps to cancer.  相似文献   
8.
The heterogeneous population of non-haematopoietic cells residing in the bone marrow (bone marrow stromal cells, BMSCs) and the different fractions and components obtained from platelet-rich plasma provide an invaluable source of autologous cells and growth factors for bone and other connective tissue reconstruction. In this study, we investigated the effect of an allogenic platelet lysate on human BMSCs proliferation and differentiation. Cell proliferation and number of performed cell doublings were enhanced in cultures supplemented with the platelet-derived growth factors (platelet lysate, PL), either with or without the concomitant addition of fetal bovine serum (FBS), compared to cultures performed in the presence of FBS and FGF2. Both in vitro and in vivo osteogenic differentiation were unaltered in cells maintained in medium supplemented with PL and not FBS (Only PL) and in cells maintained in medium containing FBS and FGF2. Interestingly, the in vitro cartilage formation was more effective in the pellet of BMSCs expanded in the Only PL medium. In particular, a chondrogenic differentiation was observed in pellets of some in vitro-expanded BMSCs in the Only PL medium, whereas pellets from parallel cell cultures in medium containing FBS did not respond to the chondrogenic induction. We conclude that the platelet lysate from human source is an effective and even more beneficial substitute for fetal bovine serum to support the in vitro expansion of human BMSCs for subsequent tissue-engineering applications.  相似文献   
9.
The repair of large segmental bone defects due to trauma, inflammation and tumor surgery remains a major clinical problem. Animal models were developed to test bone repair by tissue engineering approaches, mimicking real clinical situations. Studies differed with regard to animals (dog, sheep, goat), treated bone (femur, tibia, mandible), chemistry and structure of the scaffolds. Still, an advantage in the bone formation and in the healing of the segmental defect was always observed when scaffolds were seeded with bone marrow derived stromal cells (BMSCs). In the year 1998 was performed the first implantation of a porous ceramic construct in a bone segmental defect of a patient; it was the first construct seeded with cultured autologous osteogenic cells. Since then, only few other similar cases were treated by the same approach. However, in other fields, such as oral and maxillofacial surgery, injectable cells/platelet-rich plasma composites have been used as grafting materials for maxillary sinus floor augmentation and/or onlay plasty. More recently, the reconstruction of a human mandible was also reported by means of a bone-muscle-flap in vivo prefabrication technique, where the patient served as his own bioreactor. Indeed continuous implementations test and provide new means of defects treatment and cure. However, based on results so far obtained in animal models and pilot clinical studies, one can affirm that the bone tissue engineering approaches, although successful in most cases, need further validation before a wide application in clinics. In particular, the supply of oxygen and nutrients to the cells in the inner part of the implanted scaffolds remains a major concern, requiring additional investigations.  相似文献   
10.
Extensive bone loss is still a major problem in orthopedics. A number of different therapeutic approaches have been developed and proposed, but so far none have proven to be fully satisfactory. We used a new tissue engineering approach to treat four patients with large bone diaphysis defects and poor therapeutic alternatives. To obtain implantable three-dimensional (3D) living constructs, cells isolated from the patients' bone marrow stroma were expanded in culture and seeded onto porous hydroxyapatite (HA) ceramic scaffolds designed to match the bone deficit in terms of size and shape. During the surgical session, an Ilizarov apparatus or a monoaxial external fixator was positioned on the patient's affected limb and the ceramic cylinder seeded with cells was placed in the bone defect. Patients were evaluated at different postsurgery time intervals by conventional radiographs and computed tomography (CT) scans. In one patient, an angiographic evaluation was performed at 6.5 years follow-up. In this study we analyze the long-term outcome of these patients following therapy. No major complications occurred in the early or late postoperative periods, nor were major complaints reported by the patients. No signs of pain, swelling, or infection were observed at the implantation site. Complete fusion between the implant and the host bone occurred 5 to 7 months after surgery. In all patients at the last follow-up (6 to 7 years postsurgery in patients 1 to 3), a good integration of the implants was maintained. No late fractures in the implant zone were observed. The present study shows the long-term durability of bone regeneration achieved by a bone engineering approach. We consider the obtained results very promising and propose the use of culture-expanded osteoprogenitor cells in conjunction with porous bioceramics as a real and significant improvement in the repair of critical-sized long bone defects.  相似文献   
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