Timo Kallio

Sinusitis in the common cold

Abstract Background: Acute community-acquired sinusitis is considered a bacterial complication of the common cold. Radiologic abnormalities in sinuses occur, however, in most patients with upper respiratory virus infections. Objective: Assessment of the occurrence, clinical profile, laboratory findings, and outcome of radiologically confirmed sinusitis was carried out as part of a common cold study in young adults. Methods: Clinical examinations and radiography of the paranasal sinuses were carried out on days 1, 7, and 21 in 197 patients with the common cold. The symptoms were recorded on diary cards on days 1 to 20. Ten viruses and 5 bacteria were studied as etiologic agents of common cold as reported earlier. Serum C reactive protein concentrations, erythrocyte sedimentation rates, and total white blood cell counts with differentials were determined in 40 randomized subjects on day 7. The effect of 6 days of intranasal fluticasone propionate treatment of the common cold in the prevention of sinusitis was analyzed. Results: On day 7, 39% of patients with the common cold in the placebo group (n = 98) had sinusitis, which we would prefer to call viral sinusitis. The symptoms of patients with sinusitis and those without it were not clinically distinguishable. Viral infection was detected in 81.6% of patients with sinusitis. No significantly increased levels of antibodies to bacteria were detected. Serum C reactive protein concentrations, erythrocyte sedimentation rates, and white blood cell counts were low in patients with sinusitis. All patients made a clinical recovery within 21 days without antibiotic treatment. Fluticasone propionate treatment tended to prevent paranasal sinusitis, especially in rhinovirus-positive subjects. Conclusion: Viral sinusitis frequently occurs in the early days of the common cold, but it is a self-limited illness. The sinuses should not be imaged in patients with the common cold if the signs and symptoms of illness gradually become less severe and no specific signs suggestive of bacterial sinusitis occur. (J Allergy Clin Immunol 1998;102:403-8.)

Bonding of restorative and veneering composite resin to somepolymeric composites

OBJECTIVES The aim of the study was to determine bond strengths between different fiber-reinforced composites (FRC) and visible light-curing composites (VCR). METHODS A total of 180 specimens comprising eight types of FRC substrates and four types of VCR substrates were fabricated and divided in 36 different groups. Substrate surfaces were ground with 1200-grit silicon carbide paper before adding a repair composite (RC). The shear bond strength was determined for specimens without the use of an intermediate resin (IMR), for specimens with the IMR and for specimens with the IMR and thermocycling. Surface roughness of the substrate was measured with a profilometer before adding RC on the substrate. RESULTS The univariate analyses of variance (ANOVA) revealed significant differences (p<0.001) related to the type of the substrate, the IMR and the thermocycling. The highest shear bond strength for FRC substrates was achieved with StickNet/Z-100 combination and for VCR substrates with Sinfony/Sinfony combination. Surface roughness (R(a)) varied from 0.10 microm of Targis VCR to 0.50 microm for Vectris Pontic FRC. SIGNIFICANCE Surface roughness seemed not to influence shear bond strengths of RC to FRC and VCR substrates. High shear bond strengths were related to specific materials and IMRs used. In some cases materials performed better without the use of the accessory IMR.

The bond strength of light-curing composite resin to finally polymerized and aged glass fiber-reinforced composite substrate.

OBJECTIVE This study examines the shear bond strength of visible light-curing composite resin (VCR) to aged glass fiber-reinforced composite (FRC) substrate with multi-phase polymer matrix. METHODS Linear polymethyl methacrylate and dimethacrylate monomer preimpregnated unidirectional glass fiber reinforcement was used as an adhesion substrate for low-viscosity diacrylate veneering composite resin and restorative composite resin. A total of 60 test specimens were divided into three groups according to the brand and the use of an intermediate monomer resin (IMR). The used IMRs were either BisGMA-HEMA-resin, BisGMA-TEGDMA resin or the controls were left without the IMR treatment. Dry- and water-stored FRC-substrates were used for adhering the VCR with or without the IMR. The shear bond strength of the VCR to the substrate was measured for dry and thermocycled specimens and the results were analyzed with multi-variate ANOVA. RESULTS The highest mean shear bond strength (23.9 +/- 4.8 MPa) was achieved with FRC/BisGMA-HEMA/VCR combination when the FRC substrate was water stored and the test specimen was thermocycled. FRC/BisGMA-TEGDMA/VCR combination resulted in 15.7 +/- 6.0 MPa with the water-stored FRC substrate and after thermocycling of the test specimens. The lowest shear bond strength (1.0 +/- 0.5 MPa) was obtained with FRC/VCR combination with water-stored substrate and after thermocycling of the test specimens. Significant differences were found between the mean values of three groups according to the use of IMR (p<0.001). The storage conditions of the FRC substrate were related to brand of the IMR or the composite (p<0.001). High mean values of the shear bond strength after thermocycling fatigue were related to the type of IMR (p<0.001). SIGNIFICANCE The results suggest that the IMRs used in this study greatly influence the mean shear bond strength values when the test specimens are thermocycled.

Effect of resin application time on bond strength of polymer substrate repaired with particulate filler composite.

Four different polymeric substrates were treated with unfilled intermediate resin (IMR) for various lengths of time (15 s, 3 min, 1 h, 24 h, and 2 weeks) to find out the effect of IMR treating time on shear bond strength between the substrate and a particulate filler composite. The IMR used in the study was a diacrylate monomer resin and the particulate filler composite was added on it. Two of the tested substrates were fiber-reinforced composites (FRCs). Two other substrates were cross-linked bisphenol-A-glycidyl dimethacrylate/triethyleneglycol dimethacrylate (BisGMA/TEGDMA) substrate and linear polymethylmethacrylate substrate. The bond strength of the particulate filler composite to the BisGMA/TEGDMA substrate was significantly higher compared to the other substrates (p<0.001). A correlation between increasing shear bond strength and longer treating time were found with the BisGMA/TEGDMA substrates (r=0.594, p<0.001) whereas no correlation was found with the other substrates. Prolonging of IMR treating time enhanced the BisGMA/TEGDMA substrate bond strength to the particulate filler composite but it had no clear effect on the bond strength of other substrates.

The in vitro echogenicity of flowing blood in patients with vascular disease and the effect of naftidrofuryl

Blood echogenicity was measured in four patient groups with circulatory disturbances (myocardial infarction, stroke, claudication, and deep venous thrombosis) at hospital admission and one week later. The recording was done by an A-mode ultrasonic method at three shear rates down to 4.1 s-1. The rheological effects of adding an anti-aggregatory drug, naftidrofuryl, was tested in vitro at concentrations ranging from 10(-8)-10(-6) M. Echogenicity was lowest in blood from healthy volunteers and significantly greater in blood from patients with claudication. The in vitro addition of naftidrofuryl significantly lowered the echogenicity of blood samples taken from patients with venous thrombosis in the lower extremities. The authors suggest that increased blood echogenicity, which can be pharmacologically manipulated, may be a nonspecific indicator of disease.

The Effect of Surface Roughness on Repair Bond Strength of Light-Curing Composite Resin to Polymer Composite Substrate

Objective: The purpose of this study was to analyze the shear bond strength of a new composite resin to polymer-based composite substrates using various surface roughnesses and two kinds of polymer matrices. Materials and methods: Particulate filler composite resin with cross-linked polymer matrix and fiber-reinforced composite with semi-interpenetrating polymer matrix were used as bonding substrates after being ground to different roughnesses. Substrates were aged in water for one week before bonding to new resin composites. Twelve specimens in the substrate groups were ground with grinding papers of four grits; 320, 800, 1200 and 2400. Results: Corresponding values of surface roughness (Ra) varied from 0.09 to 0.40 for the particulate filler composite resin and 0.07 to 0.96 for the fiber-reinforced composite resin. Characteristic shear bond strength between the new resin and particulate filler composite resin was highest (27.8 MPa) with the roughest surface (Weibull modulus: 2.085). Fiber-reinforced composite showed the highest bond strength (20.8 MPa) with the smoothest surface (Weibull modulus: 4.713). Conclusions: We concluded that surface roughness did not increase the bonding of new resin to the substrate of IPN based fiber-reinforced composite, whereas the roughness contributed to bonding the new resin to the particulate filler composite resin with a cross-linked polymer matrix.

The effect of radiographic contrast media on ultrasonically detectable red blood cell aggregation in vitro.

We investigated the effect of radiographic contrast media (RCM) on red blood cell (RBC) aggregation by analyzing echogenicity of flowing blood before and after the addition of 2%, 20%, 50% or 95% volume of undiluted meglumine diatrizoate, iohexol, sodium meglumine ioxaglate, or iopamidol and equiosmolar volume concentration of saline. This was done both by stepwise increasing the concentration with minimal mixing and by stepwise decreasing the concentrations with more efficient mixing. All contrast media caused a drop in blood echogenicity after a proper mixing when compared with saline addition. After minimal stirring, both meglumine diatrozoate and iohexol caused a significant increase in blood echogenicity at volume concentrations over 50%. The paper demonstrates that earlier findings of both increased and decreased RBC aggregation following exposure to RCM can be reproduced and that the result depends on experimental setup. In diatrizoate and iohexol RBC aggregates disappear after mixing (increasing the shear rate) or when the RCM/blood mixture is diluted. After dispersement, the abnormal RBC aggregates will not reform.

Influence of intermediate resin on the bond strength of light-curing composite resin to polymer substrate

Abstract Objectives. The aim of this study was to examine the effect of intermediate resin (IMR) of different monomer compositions and viscosities on the shear bond strength between polymer substrate and light-curing composite. Methods. The substrate used in the study was an autopolymerizing polymethyl methacrylate (PMMA) based polymer. The substrate was treated with the IMR for 3 min before application of light polymerizable particulate filler composite resin. The monomers of the IMR were either bisphenol-A-glycidyl dimethacrylate (BisGMA) and triethyleneglycol dimethacrylate (TEGDMA) or BisGMA and methyl methacrylate (MMA). The shear bond strength of the IMR treated substrate to the particulate filler composite was evaluated after storing the specimens dry and after thermocycling the specimens in water. Light microscope examination was accomplished to determine the swelled layer of the substrate. Results. Significant differences were found between the shear bond strength values of the IMRs (p < 0.001). The bond strengths were generally higher in the BisGMA-MMA groups than in the BisGMA-TEGDMA groups. Two-way ANOVA revealed significant effects of type of IMR (p < 0.001) and thermocycling (p = 0.017) on the shear bond strength. No interaction was found between these variables (p > 0.05). Conclusions. The results suggest that the monomer composition and ratio of the IMRs used in the study influence the shear bond strength of the polymer substrate to the new resin.

Effect of fasting and food intake on magnetization transfer of human liver tissue

Magnetization transfer (MT) technique is a promising method in differential diagnosis of diseases in parenchymal tissues. Basic knowledge about circumstances and elementary factors that influence MT and its parameters is still insufficient, however. Having a meal before the magnetic resonance (MR) examination could change liver MT parameters compared to fasting state through alteration in liver perfusion, blood flow, and content of portal blood (proteins and other derivates from a meal). If MT parameters can be altered by a meal, then MR liver studies should always be performed after fasting. Before MRI examinations we examined three healthy volunteers after a high-fat meal with Doppler ultrasound technique to find out duration and magnitude of changes in portal blood flow. Duration of > or = 50% increased peak-flow value compared to fasting state in portal vein was > 90 min, which is enough for our MR examination. With a low-field 0.1-T MR imager we examined 10 healthy volunteers after a short (range from 3 h 45 min to 17 h 30 min) fast and also immediately after a high-fat meal. Magnetization transfer parameters, magnetization transfer ratio (MTR) and magnetization transfer rate Rwm of liver tissue were determined. MTR changed significantly (Student paired two-tailed t-test, p = .0044) after a meal, but Rwm did not (p = .0952). We recommend a 4 h fast before MR examination that aims to determine the MTR of liver tissue.

Teleradiology in Turku University Hospital - Diagnostic evaluation and clinical applications

Teleradiology installation between the Radiology Departments of the Main Hospital Compound and the Paimio Hospital, both belonging to the Turku University Central Hospital has been in clinical use since August 1991. It is based on Unix workstations with 1280 x 1024 pixel display with 216 shades of gray. It has been used to receive previous chest images from Paimio to be compared with recent films taken at TUCH Emergency Department. Scanning resolution of 1024 x 1024 pixels seems to be enough for reference images and probably sufficient for most other purposes.