In vitro differentiation of human mesenchymal stem cells on Ti6Al4V surfaces.

Long-term stability of arthroplasty prosthesis depends on the integration between the bone tissue and the implanted biomaterials, which requires the contribution of osteoblastic precursors and their continuous differentiation into the osteoblastic phenotype. Classically, these interactions are tested in vitro using mesenchymal stem cells (MSCs) isolated and ex vivo expanded from bone marrow aspirates. Human adipose tissue-derived stromal cells (AMSCs) may be a more convenient source of MSCs, according to their abundance and accessibility, but no data are available on their in vitro interactions with hard biomaterials. The aim of this work is to compare the osteogenic potential of human AMSCs and bone marrow-derived MSCs (BMMSCs) and to evaluate their response to Ti6Al4V alloy in terms of adhesion, proliferation and differentiation features, using the human osteosarcoma cell line SaOS-2 for comparison. The overall results showed that AMSCs have the same ability to produce bone matrix as BMMSCs and that Ti6Al4V surfaces exhibit an osteoinductive action on AMSCs, promoting their differentiation into functional osteoblasts and increasing bone formation. In conclusion, adipose tissue is a promising autologous source of osteoblastic cells with important clinical implications for bone tissue engineering.

The sialoglycoconjugates in the oviducts of fertile and postmenopausal women.

OBJECTIVES: The aim of the study was to investigate the distribution of the sialoderivatives of the glycoconjugates in the oviduct of normally menstruating and postmenopausal women. METHODS: Biopsies of ampullary and isthmic portions of the oviduct were obtained from fertile women, in proliferative and secretive phases, and from postmenopausal subjects. The study was carried out using digoxigenin-labelled lectins (MAA, SNA and PNA) in addition to the use of enzymatic and chemical treatments to characterize the different glycosidic linkages of the sialoderivatives and to obtain information on their structure. RESULTS: No appreciable difference in sialoderivatives distribution was observed among the oviducts, particularly at the epithelium luminal surface, of the fertile women in the two menstrual cycle phases or among those of the fertile and some postmenopausal women, independently from age. Moreover, no appreciable difference of distribution was observed between the ampullary and the isthmic portions in both the study groups. CONCLUSIONS: In the fertile women sialoderivatives present at the luminal surface of the epithelial cells could play a role in sperm capacitation and mobility, and facilitate the transit of the egg and of the early embryo along the oviducts. The similar distribution of sialoderivatives in the oviduct epithelium of some postmenopausal women of different age, compared to the fertile ones, suggests a maintaining of some functions of the organ, independently from the age of the woman. This could be due, in some cases, to the influence of remaining still sufficient sex hormonal levels.

Lectin binding in the umbilical cord in altered glycemia.

OBJECTIVE: Content and distribution of the oligosaccharides in the umbilical cord from pregnancies with altered glycemia were investigated. STUDY DESIGN: A prospective cohort study was conducted in the Florence Policlinic of Careggi, Italy. Samples of cord from physiological pregnancies (n=20), from pregnancies with minor degree of glucose intolerance (n=20) and from pregnancies with gestational diabetes mellitus (GDM) treated with insulin (n=20) were collected. Eleven lectins were used (ConA, WGA, PNA, SBA, DBA, LTA, UEA I, OOA, GSL II, MAL II and SNA) in combination with chemical and enzymatic treatments. RESULTS: Increase of N-acetyl-d-glucosamine and a loss of sialic acid in the umbilical cord of the cases with minor degree of glucose intolerance with respect to the other study groups was observed. d-Galactose(beta1-->3)-N-acetyl-d-galactosamine, N-acetyl-d-galactosamine and l-fucose were in less amount in both the pathological groups with respect to the control one. CONCLUSION: The increase of some glycoconjugates carbohydrates and the loss of others in the umbilical cord from pregnancies with minor degree of glucose intolerance might be related to its morphofunctional alterations in a not diabetic altered glycemia. Moreover, the treatment with insulin in the GDM might play a role in restoring partially the normal glycosilation in the cord components in the attempt to renew some their functions.

The oligosaccharidic content of the glycoconjugates of the prepubertal descended and undescended testis: lectin histochemical study.

The saccharidic content of the glycoconjugates has been studied in the descended the undescended testes of a 8 years old boy. For this purpose, a battery of seven HRP-conjugated lectins (SBA, DBA,PNA,WGA,UEAI, LTA and ConA) was used. D-galactose-N-acetyl-D-galactosamine and alpha-L-fucose sugar residues, which were present in the cytoplasm of the Sertoli cells of the normally positioned prepubertal testis, were not detected in the same cells of the undescended testis. The Leydig's cells of the descended testis appeared characterized by N-acetyl-D-glucosamine which was absent in the rare and atrophic Leydig's cells of the cryptorchid testis. Differences in sugar residues distribution between the descended and the undescended testis were also detected in the lamina propria of the seminiferous tubules. Peritubular myoid cells in the undescended testis only reacted with PNA, after neuraminidase digestion, thus revealing the presence of D-galactose (beta1-->3)-N-acetyl-D-galactosamine and sialic acid. In this study a complete distributional map of the sugar residues of the glycoconjugates in the descended and undescended prepubertal testis is reported.

Lectin-binding sites in newborn human testis.

The present investigation has been performed to obtain a complete distributional map of the oligosaccharidic component of the glycoconjugates in the testis of the human newborn. For this purpose seven eight HRP-conjugated lectins (SBA, DBA, PNA, WGA, OOA, UEAI, LTA and ConA) along with enzymatic treatments, were used. The Sertoli cells were characterized by the same sugar residues detected in the testes of adult healthy subject. Beta-N-acetyl-D-galactosamine in the Leydig's cells and a-N- acetyl-D-galactosamine anomer in the spermatogonia seem to be an unique feature of the newborn testis. For this fact SBA and DBA could be considered markers respectively of the Leydig's cells and of the spermatogonia in the newborn testis. Differences in lectin binding, between the newborn and the adult testis as the interstitial tissue and the endothelial cells of the capillary vessels are reported.