The macroscopic and especially microscopic properties of implant surfaces play a major role in the osseous healing of dental implants. The aim of this study was to perform a histologic and ...histomorphometric comparison of the healing characteristics of anodically modified, machined and hydroxyapatite (HA)‐coated implant types. A total of 24 machined surface implants (MSI), 24 HA‐coated implants (HCI) and 24 anodized titanium surface implants (ASI) were inserted into the mandibles of 12 adult mini‐pigs after extracting all mandibular premolars. Four animals each were killed after covered healing for 3, 6 and 12 weeks. Undecalcified ground sections were subjected to histologic and histomorphometric examinations. Primary effects and interactions were statistically evaluated and least square means (Tukey test) were compared. Histologic evaluations showed broad‐based bone apposition to HA‐coated and anodically roughened surfaces as well as narrow bone contacts to the machined surface. Localized resorption was only observed with the HA‐coated implants. Overall, histomorphometric evaluation of bone‐to‐implant contact percentages for all observation periods showed significant differences between MSI (19.39% ± 4.53) and HCI (39.05% ± 4.53;
P
= 0.0092) and between MSI and ASI (42.72% ± 4.20;
P
= 0.0011). In conclusion, the results of this study show that an anodically roughened implant may provide a similar rate of bone‐to‐implant contact as a HA‐coated implant. In the presence of bone quality II to IV, according to
Lekholm & Zarb (1985
, in: Tissue‐Integrated Prostheses: Osseointegration in Clinical Dentistry. Chicago: Quintessence Publishing), this may be of particular benefit, possibly because of higher stability, in maintaining pre‐implantation functional strength after implant healing.
To prospectively evaluate the effectiveness of portal vein embolization (PVE) and CD133(+) bone marrow stem cell (BMSC) administration to the liver, compared with PVE alone, to augment hepatic ...regeneration in patients with large hepatic malignancies.
The study was approved by the institutional ethics committee; informed consent was obtained. Thirteen patients underwent PVE of liver segments I and IV-VIII to stimulate hepatic regeneration prior to extended right hepatectomy. In six patients (three men, three women; mean age, 61 years; range, 46-72 years) with a future liver remnant volume (FLRV) below 25% and/or limited quality of hepatic parenchyma, PVE alone did not promise adequate proliferation. These patients underwent BMSC administration to segments II and III (group I). In seven patients (three men, four women; mean age, 69 years; range, 63-75 years) with an FLRV below 25%, PVE alone was performed (group II). Two radiologists blinded to patients' identity and each other's results measured liver and tumor volumes with helical computed tomography. Absolute, relative, and daily FLRV gains were compared by using the t test or the Wilcoxon test.
The increase of the mean absolute FLRV in group I from 239.3 mL +/- 103.5 (standard deviation) to 417.1 mL +/- 150.4 was significantly higher than that from 286.3 mL +/- 77.1 to 395.9 mL +/- 94.1 in group II (P = .049). The relative gain of FLRV after PVE in group I (77.3% +/- 38.2) was significantly higher than that in group II (39.1% +/- 20.4) (P = .039). The daily hepatic growth rate in group I (9.5 mL/d +/- 4.3) was significantly superior to that in group II (4.1 mL/d +/- 1.9) (P = .03). Time to surgery was 27 days +/- 11 in group I and 45 days +/- 21 in group II (P = .057).
In patients with malignant liver lesions, the combination of PVE with CD133(+) BMSC administration substantially increased hepatic regeneration compared with PVE alone.
Our study evaluated noninvasive tests for the diagnosis of atheromatous internal carotid artery (ICA) pseudo-occlusion.
Twenty patients (17 men, 3 women; mean age +/-SD, 64.3+/-11.6 years) with ...angiographically proven atheromatous ICA pseudo-occlusion (20 vessels) were prospectively examined with MR angiography (MRA; 2D and 3D time-of-flight techniques), color Doppler-assisted duplex imaging (CDDI) and power-flow imaging (PFI) with and without an intravenous ultrasonic contrast agent. As a control group, 13 patients (13 men; mean+/-SD age, 63.0+/-9.0 years) with angiographically proven ICA occlusion (13 vessels) were studied with the same techniques. For the determination of interobserver agreement (kappa statistics), the findings of each diagnostic technique were read by 2 blinded and independent observers who were not involved in patient recruitment and initial data acquisition. Specificity and sensitivity were calculated for all noninvasive techniques (observer consensus) in comparison to the standard of reference (intra-arterial angiography).
Interobserver reliabilities were kappa=0.86 for intra-arterial angiography, kappa=0.90 for unenhanced CDDI, kappa=0. 93 for enhanced CDDI, kappa=0.93 for unenhanced PFI, kappa=1.0 for enhanced PFI, kappa=0.93 for 2D MRA, and kappa=0.77 for 3D MRA, respectively (P<0.0001). Specificities and sensitivities were 0.92 and 0.70 for unenhanced CDDI, 0.92 and 0.83 for enhanced CDDI, 0.92 and 0.95 for unenhanced PFI, 1.0 and 0.94 for enhanced PFI, 1.0 and 0.65 for 2D MRA, and 0.89 and 0.47 for 3D MRA, respectively.
Advanced ultrasonographic techniques, especially PFI (with only 1 false-positive diagnosis of occlusion in the present series), can provide reliable and valid data to differentiate between ICA pseudo-occlusion and complete occlusion. In contrast, time-of-flight MRA at its present state is not capable of predicting minimal residual flow within a nearly occluded ICA.
Amphotericin B (1) was converted to a series of protected derivatives (3-5, 27). Compound 5 was degraded by ozonolysis and further elaborated to fragments 8, 14, and 15, three potential intermediates ...in a projected total synthesis of amphotericin B (1). A novel oxidative deglycosidation procedure based on radical bromination was devised and applied to the degradation of 5 and 27 to heptaenones 21 and 28, respectively. These heptaenones were stereospecifically reduced with sodium borohydride to amphoteronolide B derivatives 23 and 29, respectively. The R stereochemistry of the C-19 hydroxyl group arising from the reduction of these polyenones was confirmed by using Nakanishi's CD method on derivative 26 obtained by appropriate chemical manipulations of the reduction products. The aglycon of amphotericin B, amphoteronolide B (2), was obtained from 29 by desilylation followed by methyl ester hydrolysis.
MRI in acute appendicitis in pregnancy Dabir, D; Fürst, G; Blondin, D
RöFo : Fortschritte auf dem Gebiet der Röntgenstrahlen und der bildgebende Verfahren
182, Številka:
11
Journal Article
In the present study the time course of local bone formation following the application of PRP during implant placement was evaluated histomorphometrically and histologically.
The mandibular premolars ...of 12 adult minipigs were removed surgically and 72 sites were prepared for implant placement. Before the implants (MK III, Replace, and MK III TiUnite) were placed, autogenous PRP (8 x 10(5) to 10 x 10(5) platelets/microL) was instilled into the host sites on the left side. The animals were sacrificed at 3, 6, and 12 weeks, and undecalcified ground sections were prepared.
The histomorphometric evaluation showed significantly more bone-to-implant contact after topical PRP application in the early healing phase (6 weeks), which varied as a function of the distance from the implant surface (controls = 24.2% versus PRP = 44.21%; P = .013). At 12 weeks, the extent of osteoneogenesis was comparable in the 2 groups (controls = 51.3% versus PRP = 44.2%; P = .251). Statistical analysis revealed no significant interaction between implant surface type and PRP.
Topical PRP application significantly increased the activity of bone regeneration at implant host sites during early healing.
In the present study PRP was found to have a time- and site-dependent effect on peri-implant bone healing.
In this study, bovine hydroxyapatite (HA) alone or in combination with activated platelet-rich plasma (PRP) was examined for its usefulness for single-stage sinus grafting in minipigs. In 12 adult ...minipigs, Schneider's membrane of 24 sinuses was elevated bilaterally through an extra-oral approach. The material was divided into two groups of 12 sinuses. In one of these groups, the space between Schneider's membrane and the sinus wall was grafted with activated autogenous PRP and HA (PRP side). In the other, HA alone was used for grafting (control side). At the same time two dental implants with a machined surface were inserted into the grafting material through the facial sinus wall. Four animals of each group were sacrificed at 3, 6 and 12 weeks, and undecalcified thin-cut and ground sections (Donath 1988) stained with toluidine blue were prepared. In the facial sinus wall, fewer bone-to-implant contacts were present on the PRP side at 3 and 6 weeks than on the control side. At 12 weeks, the PRP side had caught up with the control side. In grafted bone, contacts on the PRP side were more extensive than on the control side at 3 weeks, had dropped below control side levels at 6 weeks and surpassed these at 12 weeks. This study showed that PRP has a differential effect on osseointegration in grafted bone and local host bone. Combined with HA it was not demonstrably superior to HA alone.
Magnetic resonance imaging is a promising tool for in vivo analysis of the neuropathology underlying schizophrenia. One of the most consistent features emerging from the majority of published studies ...is the lateralization of pathological findings, and this has led to hypotheses of impaired hemispheric specialization in schizophrenia. In previous work, we have validated morphometry of supratemporal language-related cortex using high-resolution magnetic resonance imaging and analyzed the relation of the so defined planum temporale to functional parameters of hemispheric specialization. In the present study, we examined planum temporale structural asymmetry in first-episode schizophrenics. Asymmetry coefficients obtained in these patients did not differ significantly from those in equally right-handed controls and were not correlated to standard psychopathological measures. These data are contrasted with other studies reporting lateralized brain pathology in schizophrenia with special emphasis on methodological considerations in neuroimaging procedures.
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