Boiling diluted alkali incubation was found to be an effective way to prepare bioactive Ti6Al4V surfaces, whether polished or not, as indicated in vitro after immersion in two different supersaturated calcification solutions (SCSs). The induction of calcium phosphate (Ca-P) precipitation from the SCSs is most probably made possible by the formation of a new TiO2 surface layer and a large number of submicron-scaled etched pits therein. The morphologies and composition of the Ca-P deposited from different SCSs are entirely different from each other. The processes on Ti6Al4V surfaces during treatment and immersion were investigated in detail by means of scanning electron microscopy combined with energy dispersive X-ray analysis, X-ray photoelectron spectroscopy and X-ray diffraction.

Alloys↗

PubMedDate not supplied

Tissue reaction to bone-anchored percutaneous implants in rabbits.

It has been demonstrated that direct attachment to bony skeletal tissues favors the longevity of percutaneous devices (PDs). This study is focused on improvement of the success rates by using a two-stage implantation technique. For this purpose, cylindrical-shaped PDs were inserted into the tibia of rabbits. The enossal part of the implants was made of Ti6Al4V and was coated with a layer hydroxyapatite (HA). The percutaneous part was made of dense HA. In a first surgical session, the enossal part of the implants was inserted. In a second implantation session, about 3 months later, the percutaneous part was fixed into the enossal part. The implants were left in situ for 5 months after the second session. Clinical and histological investigations were performed. The results confirmed the previous finding--that bone anchoring is effective in the maintenance of a permanent percutaneous passage. On the other hand, it could not be proven that a two-stage implantation procedure improves the success rate of one-stage bone-anchored PDs.

Animals↗

PubMedDate not supplied

Severe CNS manifestations as the clinical hallmark in generalized Wegener's granulomatosis consistently negative for antineutrophil cytoplasmic antibodies (ANCA). A report of 3 cases and a review of the literature.

OBJECTIVE: Antineutrophil cytoplasmic antibodies (ANCA) directed against proteinase 3 are highly specific for Wegener's granulomatosis (WG); their sensitivity for active generalized WG is nearly 100%. There are patients, however, who fulfill both the ACR 1990 criteria and the CHC 1992 definition for WG but who remain ANCA negative. The authors report 3 young patients with biopsy-proven active generalized WG who were consistently negative for ANCA over observation times ranging from 58 to 114 months. METHODS: ANCA titers were determined serially every 3 months. ANCA-negativity was defined by the absence of any fluorescence pattern on IFT plus the absence of any specific ELISA reactions. This included negative results for the antibody classes IgG, IgM and IgA. The sera of all patients were also tested in a capture PR3-ANCA ELISA. At 1- to 6-month intervals each patient underwent a standardized set of interdisciplinary examinations. RESULTS: Although CNS involvement in large WG cohorts is about 10%, severe CNS manifestations were the clinical hallmark in all 3 patients. One patient suffered from both intraspinal and intracerebral disease with fatal outcome; the other 2 had meningeal manifestations that responded favorably to immunosuppressive therapy. CONCLUSION: Severe CNS manifestations could represent a clinical hallmark of patients with generalized Wegener's granulomatosis who are consistently negative for antineutrophil cytoplasmic antibodies (ANCA).

Adult↗

PubMedDate not supplied

Tracheal reconstruction with hydroxyapatite tracheal prosthesis.

A porous hydroxyapatite tracheal prosthesis was implanted in rabbits after resection of a 15 mm circular segment of the cervical trachea. Postoperatively the animals were followed by radiography, bronchoscopy, and microscopy at the time of autopsy. The longest survival time was 22 weeks. All the rabbits died of infection at the prosthetic site or of progressive stenosis at the anastomoses. The prosthesis was incorporated by surrounding tissues, but no overgrowth of ciliated epithelium on the luminal surface of the prosthesis was observed. Although a hydroxyapatite tracheal prosthesis is tolerated in rabbits, covering of the luminal surface of the prosthesis with a non-porous layer to prevent infection and to permit mucosal overgrowth is necessary to achieve better long-term results.

Animals↗

PubMedDate not supplied

A 5-year evaluation of apatite toothroots as means to reduce residual ridge resorption.

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Adolescent↗

PubMedDate not supplied

[ANCA-associated vasculitis (Wegener's granulomatosis, Churg-Strauss syndrome, microscopic polyangiitis). 2. Diagnostic procedure].

The ANCA-associated vasculitides (Wegener's granulomatosis, Churg-Strauss syndrome, microscopic polyangiitis) are characterized by a broad spectrum of clinical manifestations and a highly variable clinical course. Due to greatly improved diagnostic techniques the number of newly diagnosed cases has increased rapidly within the past few years. This facilitated more individualized treatment and led to the concept of stage-adapted treatment. Immunodiagnostic parameters are being utilized increasingly to supplement clinical and radiological findings. Inflammatory lesions are visualized by, for example, e.g. rhinoscopy, sinoscopy, and bronchoscopy or by radiological techniques including cranial and skeletal muscle magnetic resonance imaging, pulmonary high-resolution computed tomography, and digital subtraction angiography. These techniques not only serve to detect the extent of tissue and organ involvement, but also to direct bioptic procedures. Conventional histopathology must be supplemented by immunohistology in order to distinguish between the "immune complex vasculitides" and the ANCA-associated "pauci-immune vasculitides".

Antibodies, Antineutrophil Cytoplasmic↗