Dental implant prostheses cannot preclude a correct and stable implant osseointegration, which is still a challenge and greatly depends on biomaterial-cell interface. Titanium (Ti) coating using polyelectrolyte poly-L-lysine (PLL) may represent an interesting and simple approach, to provide a charged surface net able to improve cell adherence. However, in vitro and in vivo effects of Ti coated with PLL have been poorly investigated. The aims of the present study are (1) to obtain and characterize, chemically and physically, Ti disks coated with PLL (TiPLL); (2) to perform in vitro studies on osteoblast cell lines' cytocompatibility and functionality (alkaline phosphatase [ALP] activity, calcium deposition, proinflammatory interleukin 6 production); (3) to obtain in vivo evidence of osseointegration, using a sheep animal model. XPS, AFM, and contact-angle analyses demonstrated that the Ti disk was successfully covered with PLL, providing higher hydrophilicity to the Ti disk. No cellular toxicity, enhanced calcium deposition, and a decreased tendency toward interleukin-6 production were observed in the osteoblast seeded onto TiPLL. In vivo experiments showed cortical bone microhardness at 3 months significantly improved in the presence of the PLL coating. PLL coating on Ti implants seemed to safely enhance calcium deposition and implant early osseointegration in animals, suggesting promising evidence to optimize the surface properties of dental implants.
A 4-year-old, male cat was presented with a fixed, subcutaneous mass in the lumbosacral region. A histopathological examination revealed a well-defined but nonencapsulated neoplasm characterized by a proliferation of predominantly spindle cells, with high mitotic activity. Interspersed between these cells were single cellular elements with chondroid differentiation. Large areas of cartilaginous tissue with foci of endochondral ossification, necrosis and myxoid tissue were also observed within the neoplastic parenchyma. A diagnosis of extraskeletal mesenchymal chondrosarcoma was made based on the histological pattern - characterized by the coexistence of cartilaginous islands and undifferentiated mesenchymal cells, results of Alcian blue staining at various pH, immunohistochemical reactivity against vimentin and S-100, and the absence of skeletal involvement or other primary tumour sites. Clinical history of the cat excluded traumas, vaccinations or other types of subcutaneous inoculation. Six months on from surgical treatment, neither recurrence nor metastases have been detected.
An experimental protocol was designed to study the survival and behaviour of an allograft of amniotic epithelial cells (AECs) in an ovine model. The study was conducted on three healthy adult sheep. A core lesion was created in both calcaneal tendons under ultrasound (US) guidance by injecting 400 UI of Type 1A collagenase diluted in 0.6 ml saline. The AECs were obtained from a 60-80-day-old fetus and cultured under standard conditions. After 15 days of collagenase treatment, 2 x 10(6) AECs stained with a vital membrane fluorescent probe (PHK26) were injected under US guidance in 500 microl saline solution into the lesion of one limb. The contralateral untreated limb was used as a control. Animals were euthanatized 7 (1) and 30 (2) days later. Histological analyses performed on explanted tendons clearly demonstrate that AECs survived for at least 1 month inside the lesion without any adverse reactions. The damaged tissue of the treated tendons showed a high number of reparative cells in active proliferation that were accumulating collagen within the extracellular matrix. In addition, after 1 month, the neo-collagen began to be organized into parallel arrays of fibers oriented along the longitudinal axis of the tendon.
The aim of this study was to evaluate, during the first 4 wk of life, the involution of umbilical structures in clinically healthy calves and in calves affected by umbilical disorders, in both B-mode and color Doppler ultrasonography. The present study was carried out on 63 Holstein Friesian calves, divided into 3 different groups: group H (clinically healthy, n = 17), group A, (affected by omphaloarteritis, n = 24), and group V (affected by omphalophlebitis, n = 22). B-mode ultrasonography was performed at weekly intervals, using a portable device (LOGIQ Book XP, GE Healthcare, Little Chalfont, UK) and a linear multifrequency 7 to 10 MHz probe. In addition to the ultrasound examinations, the umbilicus of the calves was also evaluated using a color Doppler. The extra-abdominal as well as the intra-abdominal hemodynamics within the umbilical structures were evaluated using 3 different ranges of speed-flow detections (23, 14, and 7 cm/s). In healthy calves, as the age increased, the umbilical structures decreased in size and their ultrasonographic identification became more difficult. Conversely, in affected calves the umbilical structures did not show the same progressive reduction of external diameters and areas, but had an irregular trend of regression. Also the color Doppler ultrasonography showed a significant difference in frequency and percentage of speed-flow in the early days of examination between the 3 groups, with the most reliable results detected from the umbilical arteries. In our experimental study, omphaloarteritis could be detected at the d 1 color Doppler exam, with a 100% specificity and a 100% positive predictive value.
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