Fracture resistance and reinforcement of immature roots with gutta percha,mineral trioxide aggregate and calcium phosphate bone cement: a standardized in vitro model

Abstract –  Endodontic treatment of immature teeth is often complicated because of flaring root canals and open apices for which apexification is needed. Long‐term prognosis for these teeth is surprisingly low because of cervical root fractures occurring after an impact of weak forces. In this study, an experimental model was developed to determine the fracture resistance of immature teeth and to test the hypothesis that endodontic materials succeed in reinforcing them. Compact and hollow bone cylinders from bovine femurs were used as standardized samples. In order to evaluate the experimental model, fracture resistance in both groups was evaluated by determining the ultimate force to fracture (UFF) under diametral tensile stress. Analysis of variance (ANOVA) revealed a statistically significant difference between the mean values of UFF for both groups, independently of the sampling location or subject. In a following setting, the hypothesis that obturation with gutta percha (GP), mineral trioxide aggregate (MTA), or calcium phosphate bone cement (CPBC) reinforces the hollow bone samples was investigated. Obturation resulted in a significant reinforcement for all materials, but the degree of reinforcement depended on the material. The experimental model appeared to be suitable for in vitro investigation of reinforcement and fracture resistance in a standardized way.     

Haptoglobin polymorphism and lacunar stroke

Haptoglobin (Hp) 2-2 phenotype has been associated with peripheral and coronary artery disease and risk of vascular complications in diabetic patients, but any association of Hp polymorphism with cerebrovascular disease has not been explored so far. We aimed to study Hp polymorphism in a sample of 124 patients with a rather homogeneous type of cerebrovascular disease, namely first symptomatic lacunar stroke due to small vessel disease, in comparison with a large (n=918) control group. Hp phenotypes were determined using starch gel electrophoresis. Hp1 allele frequency was significantly higher in patients than in controls (0.480 vs. 0.395, p<0.05), mainly due to a lower Hp2-2 phenotype frequency (25.0 vs. 36.3 %; OR 0.59; 95%CI 0.38-0.90; p<0.05). This was even more pronounced in younger (相似文献   

Brucellar spondylodiscitis: case report

Brucellosis is a common zoonosis which still remains a major health problem in certain parts of the world. Osteoarticular involvement is the most frequent complication of brucellosis, in which the diagnosis of brucellar spondylodiscitis is often difficult since the clinical presentation may be obscured by many other conditions. Herein, we report an uncommon case of spondylodiscitis due to Brucella in a male who presented with abdominal pain. The diagnosis was established by positron emission tomography combined with computed tomography (PET/CT scan) and magnetic resonance followed by a confirmation on Brucella-agglutination test and positive culture of computed tomography (CT) guided punction fluid. This case report illustrates an atypical presentation of spondylitis and points out the difficulties in diagnosing the aetiological agens Brucella and differentiating its specific features from tuberculosis.     

A new decomposition product of dihydroartemisinin

After prolonged storage, samples of dihydroartemisinin were found to contain a decomposition product with a molecular weight of 238, as evidenced by MS analysis, the formation of which was accelerated by heating at 60 degrees C for several days. This decomposition product was isolated and identified as 2-(3-oxobutyl)-3-methyl-6-(2-propanal)-cyclohexanon, known to be formed by thermolysis of dihydroartemisinin at 190 degrees C. However, during work-up of this compound a hitherto unknown decomposition product of dihydroartemisinin with a molecular weight of 210 was obtained and identified by 1H, 13C and two-dimensional NMR spectroscopy as 2-(3-oxobutyl)-3-methyl-6-ethyl-cyclohexanon. Most probably this product was formed by oxidation of the aldehyde functionality of the former decomposition product and subsequent decarboxylation.     

Ethnobotanical survey and antibacterial activity of some plants used in Guinean traditional medicine

A total of 418 healers have been interviewed in Guinea, a coastal country of West Africa, ranging between 7 degrees 30 and 12 degrees 30 of northern latitude and 8 degrees and 15 degrees of western longitude. Plant species used by the local inhabitants to treat infectious diseases were identified using ethnobotanical, ethnographic and taxonomic methods. During these investigations, 218 plants were registered, of which the following were the most frequently used: Erythrina senegalensis, Bridelia ferruginea, Crossopteryx febrifuga, Ximenia americana, Annona senegalensis, Cochlospermum tinctorium, Cochlospermum planchonii, Lantana camara, Costus afer, Psidium guajava, Terminalia glaucescens, Uapaca somon and Swartzia madagascariensis. Most plants, and especially the leaves, were essentially used as a decoction. In order to assess antibacterial activity, 190 recipes were prepared and biologically tested, among which six showed activity (minimal inhibitory concentration<125 microg/ml) against Bacillus cereus, Mycobacterium fortuitum, Staphylococcus aureus, or Candida albicans, i.e., Entada africana, Chlorophora regia, Erythrina senegalensis, Harrisonia abyssinica, Uvaria tomentosa, and a mixture of six plants consisting of Swartzia madagascariensis, Isoberlinia doka, Annona senegalensis, Gardenia ternifolia, Terminalia glaucescens and Erythrina senegalensis.     

Ethnopharmacological survey of the Bunda district, Tanzania: plants used to treat infectious diseases

An ethnobotanical study was carried out in six villages in the Bunda district, Mara Region, Tanzania, where the use of plants still has a special meaning to the society, in the treatment of various diseases. Information was obtained from the traditional healers and other experienced persons, having some knowledge on medicinal plants. Fifty-two plants were reported for use in the treatment of various infectious diseases. These plants belong to 29 families, with Papilionaceae being the most represented. Leaves ranked the highest, especially for use in topical preparations. Oral administration was the most frequently used route of administration. Twenty-one percent of the recorded plants were reported for treating venereal diseases, with syphilis and gonorrhea being the most commonly mentioned. Information providers requested feedback with regard to the plants proven scientifically to be toxic in order to avoid risks while offering their services. From this work it was found out that, people in this area commonly use medicinal plants with trust they have built on the curative outcome witnessed. As the first ethnobotanical study in Bunda district recording 52 plants in a small area covered, publication of this work is expected to open up more studies to record many useful medicinal plants unfolded.     

DNA intercalation, topoisomerase II inhibition and cytotoxic activity of the plant alkaloid neocryptolepine

Cryptolepine and neocryptolepine are two indoloquinoline alkaloids isolated from the roots of the African plant Cryptolepis sanguinolenta. Both drugs have revealed antibacterial and antiparasitic activities and are strongly cytotoxic to tumour cells. We have recently shown that cryptolepine can intercalate into DNA and stimulates DNA cleavage by human topoisomerase II. In this study, we have investigated the mechanism of action and cytotoxicity of neocryptolepine, which differs from the parent isomer only by the orientation of the indole unit with respect to the quinoline moiety. The biochemical and physicochemical results presented here indicate that neocryptolepine also intercalates into DNA, preferentially at GC-rich sequences, but exhibits a reduced affinity for DNA compared with cryptolepine. The two alkaloids interfere with the catalytic activity of human topoisomerase II but the poisoning activity is slightly more pronounced with cryptolepine than with its isomer. The data provide a molecular basis to account for the reduced cytotoxicity of neocryptolepine compared with the parent drug.     

Cytotoxic Effects of Vitamin A in Combination with Vincristine, Daunorubicin and 6-Thioguanine upon Cells from Lymphoblastic Leukemic Patients

We studied whether isotretinoin potentiated the effects of vincristine (VCR), daunorubicin (DNR), and 6-thioguanine (6-TG) against cells obtained from 24 patients with acute lymphoblastic leukemia (ALL). Treatment with 5 μg /ml isotretinoin alone resulted in a leukemic cell survival of 82%± 28.1%. So isotretinoin is toxic to ALL cells. Dose-response curves were obtained for VCR, DNR and 6-TG in the presence and absence of isotretinoin Isotretinoin showed additive leukemic cell kills in combination with VCR and DNR, When corrected for cell kill by isotretinoin alone, it appeared that isotretinoin did not significantly enhance leukemic cell kills by VCR, DNR and 6-TG. No differences were found between samples from patients at initial diagnosis and at relapse with respect to cell kill by isotretinoin alone and with respect to a possible synergistic effect of isotretinoin and the cytostatic drugs. It is concluded that isotretinoin has additive antileukemic effects in combination with VCR or DNR. However, isotretinoin does not potentiate the antileukemic effects of VCR, DNR and 6-TG against leukemic cells obtained from patients with ALL.