Mechanical and biological performance of axially loaded novel bio-nanocomposite sandwich plate-type implant coated by biological polymer thin film.

Post-surgical infection is one of the essential problems in bone scaffolds that is usually treated with antibiotics. This issue may be related to the poor blood supply for bone tissue due to high concentrations of drug. In the current study, the effect of zinc oxide (ZnO) nanoparticles on the antibacterial behavior of the nanocrystalline hydroxyapatite (n-HA) scaffolds coated by gelatin-ibuprofen (GN-IBO) is evaluated. To this end, the bio-nanocomposite scaffolds are fabricated via the space holder technique and then characterized with the aid of X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The compressive strength, fracture toughness, porosity, elastic modulus as the mechanical properties, and the apatite formation, biodegradation, drug release and wettability beside the roughness as the biological properties are predicted. The obtained experimental results indicate that the bio-nanocomposite scaffolds containing 10 wt% ZnO has suitable mechanical and biological properties. After that, an analytical model is developed to predict the nonlinear instability and vibration responses of an axially loaded sandwich plate-type implants made of the fabricated n-HA-ZnO bio-nanocomposites coated by GN-IBO thin film corresponding to various weight fractions of ZnO nanoparticles. It is found that ZnO peaks in the positions of 2θ are equal to 31.6°, 33.6°, 34°, 46.4°, and 62°, which represent the crystalline characteristics. Also, it is revealed that through addition of ZnO nanoparticles, the hardness and elastic modulus as well as the bone formation and biodegradation rate of the bio-nanocomposite scaffold enhance, while its drug release in the phosphate buffer solution detected with UV spectrum reduces. It is found that by increasing the ZnO weight fraction, the critical axial buckling load of the sandwich bio-nanocomposite implant enhances, and it buckles at lower axial shortening. However, it is seen that for higher value of wt% ZnO, its influence on the critical buckling load decreases.

[Autopsy results of deep mycoses in hematologic neoplasms (1053 patients]. / Obduktionsergebnisse zu tiefen Mykosen bei hämatologischen Neoplasien (1053 Patienten).

1053 autopsies were performed during the period from 1976 to 1990 in patients with leukaemia and malignant lymphomas. At autopsy 184 of these (17.4%) presented with deep-seated mycoses. There was an increasing percentage of mycoses per year with a maximum of 30% in 1990. Today deep-seated mycoses are the most frequent lethal complication in haematologic neoplasias. As expected their number was especially high in patients with acute leukaemia but in recent years they were nearly just as frequent in myeloproliferative disorders. Among Non-Hodgkin lymphomas (NHL) they were twice as frequent in low-grade cases as in high-grade cases possibly due to a different extent of bone marrow infiltration. In contrast to former years more aspergillosis than Candida infections are found, probably as a result of antimycotic therapy.

[Deep mycoses in leukemia and malignant lymphoma]. / Tiefe Mykosen bei Leukämien und malignen Lymphomen.

1053 autopsies were performed from 1976 to 1990 in patients with leukemia and malignant lymphomas. At autopsy 184 of these (17.4%) presented with deep seated mycoses. There was an increasing percentage of mycoses per year with a maximum of 30% in 1990. Today deep seated mycoses are the most frequent letal complication in hematologic neoplasias. As expected their number was especially high in patients with acute leukemia but in recent years they were nearly just as numerous in myeloproliferative disorders. Among NHL they were twice as frequent in low grade cases as in high grade cases possibly due to a different extent of bone marrow infiltration. In contrast to former years more aspergilloses than candida infections are found, probably as a result of antimycotic therapy.

[Atypical congenital dyserythropoietic anemia]. / Atypische kongenitale dyserythropoietische Anämie.

The case is presented of a 26-year-old male patient suffering from chronic anemia since infancy. At age 12 (1972), congenital dyserythropoietic anemia (CDA) was diagnosed which could not be grouped with one of the three known variants of CDA. From onset the disease was complicated by thrombocytopenia with severe hemorrhagic diathesis. After splenectomy (1972) an extremely enlarged accessory spleen was removed in 1985 disclosing, histologically, excessively developed extramedullary hematopoiesis. Since bone marrow biopsy showed massive hyperplasia, the cellular phase of a myeloproliferative syndrome could not be excluded by histology alone.--Only a few cases of CDA with involvement of granulocytes and megakaryocytes have been reported so far. It is not clear whether or not they should be classed with CDA. In any event, involvement of granulopoiesis and/or thrombopoiesis indicates a genetic lesion of very early precursors, perhaps stem cells. It is proposed that such variants would be more correctly designated "congenital dyshematopoietic syndromes".

[Deep mycoses in leukemias and malignant lymphomas]. / Tiefe Mykosen bei Leukämien und malignen Lymphomen.

Of 590 autopsies during the period 1976 to 1983 in patients with leukaemia and malignant lymphomas there were 89 cases (15%) involving deep-seated mycoses. In the last three years the frequency of mycotic infections has risen considerably even though effective drugs are available today. The increase occurred particularly in acute leukaemias but was also found in chronic myelogenous leukaemias and in cases with high-malignancy non-Hodgkin lymphomas. An opportunistic fungal infection in Hodgkin's disease and in patients with plasmocytoma was rare. Candidosis and aspergillosis predominated histologically. About 70% of deep-seated mycoses were severe infections having a decisive influence on the course of the disease. On the basis of this retrospective analysis it can be concluded that the occurrence of mycoses is influenced, first and foremost, by 3 factors: 1. The antineoplastic therapy 2. The nature of the underlying disease 3. The intensity of the supportive measures.