3D dento-maxillary osteolytic lesion and active contour segmentation pilot study in CBCT: semi-automatic vs manual methods

Objectives:

This study was designed to evaluate the reliability of a semi-automatic segmentation tool for dento-maxillary osteolytic image analysis compared with manually defined segmentation in CBCT scans.

Methods:

Five CBCT scans were selected from patients for whom periapical radiolucency images were available. All images were obtained using a ProMax® 3D Mid Planmeca (Planmeca Oy, Helsinki, Finland) and were acquired with 200-μm voxel size. Two clinicians performed the manual segmentations. Four operators applied three different semi-automatic procedures. The volumes of the lesions were measured. An analysis of dispersion was made for each procedure and each case. An ANOVA was used to evaluate the operator effect. Non-paired t-tests were used to compare semi-automatic procedures with the manual procedure. Statistical significance was set at α = 0.01.

Results:

The coefficients of variation for the manual procedure were 2.5–3.5% on average. There was no statistical difference between the two operators. The results of manual procedures can be used as a reference. For the semi-automatic procedures, the dispersion around the mean can be elevated depending on the operator and case. ANOVA revealed significant differences between the operators for the three techniques according to cases.

Conclusions:

Region-based segmentation was only comparable with the manual procedure for delineating a circumscribed osteolytic dento-maxillary lesion. The semi-automatic segmentations tested are interesting but are limited to complex surface structures. A methodology that combines the strengths of both methods could be of interest and should be tested. The improvement in the image analysis that is possible through the segmentation procedure and CBCT image quality could be of value.     

The agonist SR 146131 and the antagonist SR 27897 occupy different sites on the human CCK(1) receptor

1-[2-(4-(2-Chlorophenyl)thiazol-2-yl) aminocarbonyl indoyl] acetic acid (SR 27897) is an effective CCK₁ receptor antagonist, while the structurally related molecule 2-[4-(4-chloro-2,5-dimethoxyphenyl)-5-(2-cyclohexyl-ethyl)-thiazol-2-ylcarbamoyl]-5,7-dimethyl-indol-1-yl-1-acetic acid (SR 146131) is a highly potent and specific agonist for the same receptor. To discover how the two molecules interact with the human cholecystokinin (CCK) CCK₁ receptor, we have carried out binding and activity studies with 33-point mutated receptors. Only six mutants showed altered [³H]SR 27897 binding properties, Lys¹¹⁵, Lys¹⁸⁷, Phe¹⁹⁸, Trp²⁰⁹, Leu²¹⁴ and Asn³³³. In contrast, numerous mutations throughout the receptor either reduced SR 146131 agonist potency, Phe⁹⁷, Gly¹²², Phe¹⁹⁸, Trp²⁰⁹, Ile²²⁹, Asn³³³, Arg³³⁶ and Leu³⁵⁶ or increased it, Tyr⁴⁸, Cys⁹⁴, Asn⁹⁸, Leu²¹⁷ and Ser³⁵⁹. Only mutations of Phe¹⁹⁸, Trp²⁰⁹ and Asn³³³ affected both SR 27897 and SR 146131 binding or activity. The collated information was used to construct molecular models of SR 27897 and SR 146131 bound to the human CCK₁ receptor. The clear difference in the binding sites of SR 27897 and SR 146131 offers a molecular explanation for their contrasting pharmacological characteristics.     

Ex vivo evaluation of a new neonatal/infant oxygenator: comparison of the Terumo CAPIOX Baby RX with Dideco Lilliput 1 and Polystan Safe Micro in the piglet model

OBJECTIVE: A newly developed neonatal and infant oxygenator with a nonheparin biocompatible polymer coating, low priming volume (43 mL), high oxygen transfer, wide operating range (<1.5 L/min) and low pressure drop represents a promising solution for cardiac surgery in neonates and infants. We compared the new CAPIOX Baby RX, Terumo (BRX) with two commonly used neonatal oxygenators: Dideco Lilliput 1 (DL1) and Polystan Safe Micro (PSM) in a piglet model. METHODS: Fifteen piglets (5.6 +/- 1.3kg) were placed on standardized cardiopulmonary bypass (CPB) for 6 hours using one of the three oxygenators (n = 5 in each group). After 120 min, the system was cooled to 25 degrees C for 60 min and then returned to normothermia. Arterial and venous blood gas data and temperature were recorded continuously by a CDI500 System (Terumo). Pressure drop, FiO2 and gas flow were recorded. Blood samples were taken before CBP, after 10 min, before and after cooling, and at the end. Total blood counts, thrombin-antithrombin complex and plasma-free haemoglobin (PfHb) were measured. RESULTS: All oxygenators showed acceptable performance for the duration of CPB. The BRX had lower mean gas flow (0.33 +/- 0.05 L/min) and FiO2 (0.43 +/- 0.02%) throughout CPB than the DL1 (1.14 +/- 0.25 L/min, p = 0.006 and 0.60 +/- 0.02%, p = 0.009, respectively) or the PSM (1.47 +/- 0.87 L/min and 0.54 +/- 0.08%, p = ns). Pressure drop in the BRX group ranged from 12 to 22 mmHg. This was significantly lower than in the DL1 group (39-65 mmHg, p = 0.005). In the PSM group, values ranged between 24 and 33 mmHg (p = ns). The increase in PfHb at six hours was significantly lower in the BRX (11.3 +/- 4.2 ng/dL) versus the DL1 (42.2 +/- 6.1 ng/dL, p = 0.004) and the PSM (56.7 +/- 15.5 ng/dL, p = 0.045). CONCLUSIONS: The BRX is as safe as the DL1 and the PSM, with superior performance in pressure drop, efficient blood gas management and lower haemolysis. The BRX exhibited the lowest prime, hold-up volume and breakthrough time.     

Prevention of Biliary Stent Occlusion by Ursodeoxycholic Acid plus Norfloxacin

We report a prospective randomized multicenter trial that tested the efficacy of combining ursodeoxycholic acid and norfloxacin in the prevention of polyethylene stent clogging in patients with obstructive jaundice due to an unresectable malignancy at the level of the common bile duct. After insertion of a 10-Fr straight polyethylene stent, patients were allocated to receive oral treatment with ursodeoxycholic acid and norfloxacin, or conservative treatment. The primary outcome measure was stent blockage within six months. Thirty-three patients (group I) received ursodeoxycholic acid and norfloxacin, and 29 received conservative treatment (group II). At six months, cumulative stent patency rate did not differ significantly between group I (47 ± 11%, mean ± se, median 149 days) and group II patients (24 ± 10%, mean ± se, median 100 days, P = 0.23, log-rank test). Four stents were clogged by ursodeoxycholic acid. Survival did not differ between the two groups. Combined therapy with ursodeoxycholic acid and norfloxacin failed to improve stent patency. Moreover, ursodeoxycholic acid can cause stent obstruction.     

Tripe palms associated with systemic mastocytosis: the role of transforming growth factor-α and efficacy of interferon-alfa

Tripe palms are thickened, moss-like or velvety textured exaggerations of the normal dermatoglyphics. The disease belongs to the spectrum of papulosquamous paraneoplastic syndromes. Although suspected, the role of transforming growth factor-α (TGF-α) has not been clearly established. A 54-year-old man with systemic mastocytosis presented with thickening and darkening of the palms and soles. We performed skin biopsies for light microscopy (including toluidine blue), in situ hybridization and double labelling, and determination of serum tryptase, histamine and TGF-α levels. Toluidine blue stained the mast cells that had massively infiltrated the dermis. Tripe palm samples showed extensive hyperkeratosis. The TGF-α probe reacted strongly with the mast cells that also reacted with the antitryptase monoclonal antibody. Elevated tryptase, histamine and TGF-α levels prior to interferon-alfa administration decreased under treatment. The demonstration of TGF-α in infiltrating mast cells, the clinical regression of tripe palms and the lowering of the serum level and the mast cell molecular signal of the cytokine when systemic mastocytosis was controlled by interferon-alfa, suggest a key role for TGF-α in this cutaneous paraneoplastic syndrome.