Void detection in root fillings using intraoral analogue, intraoral digital and cone beam CT images.

AIM: To compare void detection in root fillings using different radiographic imaging techniques: intraoral analogue, intraoral digital and cone beam CT (CBCT) images and to assess factors influencing small void detection. METHODOLOGY: Two straight root canals in canine teeth were prepared. Calibrated steel wires of five different diameters (200, 300, 350, 500, 800 microm) were inserted respectively in the canal after the injection of a sealer. To simulate filling voids of known dimensions, the wires were removed after the sealer had set. Each sample was imaged, using a Minray X-ray tube (Soredex, Helsinki, Finland) at optimal clinical settings combined with Vistascan PSP (Dürr Dental, Bietigheim-Bissingen, Germany), Digora Optime PSP (Soredex), Sigma CCD (Instrumentarium, Tuusula, Finland) and E-speed films (Agfa-Gevaert, Mortsel, Belgium). The teeth were also imaged using CBCT (3D Accuitomo, Morita, Japan). A generalized mixed model and ANOVA analysis were used on the acquired data (Tukey-Kramer correction). RESULTS: There was no evidence that the factor 'root level' affected void detection in root fillings. 'Void size' was a main determining factor as all voids larger than 300 microm were determined with all techniques. For the smaller voids, there were significant differences between the 5 imaging techniques at different void sizes and different root levels. CONCLUSIONS: Void size and imaging technique were main determining factors. Voids larger than 300 mum were determined with all imaging techniques. For small void detection, all digital intraoral techniques performed better than intraoral analogue and CBCT images.

Antioxidant treatment with N-acetylcysteine during adult respiratory distress syndrome: a prospective, randomized, placebo-controlled study.

OBJECTIVE: To examine whether the antioxidant N-acetylcysteine could ameliorate the course of the adult respiratory distress syndrome (ARDS) in man. DESIGN: Randomized, double-blind, placebo-controlled study. SETTING: Medical and surgical ICU in a regional hospital. PATIENTS: Sixty-six ICU patients with ARDS. INTERVENTIONS: Patients with ARDS (PaO2/FiO2 ratio less than 250 torr) were treated with either the antioxidant N-acetylcysteine 150 mg/kg as a loading dose and then 20 mg/kg/hr, or with placebo for 6 days. MEASUREMENTS AND MAIN RESULTS: No improvement could be demonstrated in the PaO2/FiO2 ratio in the study group as compared with the control group on any day. Pulmonary compliance was higher in the N-acetylcysteine group than in the placebo group on all days, but this difference did not reach the chosen 5% level of significance. No difference between the two groups could be demonstrated on chest radiograph or on survival rate. We documented that N-acetylcysteine acts as an anticoagulant and perhaps decreases pulmonary fibrin uptake during ARDS. CONCLUSIONS: N-acetylcysteine might be of benefit in ARDS. Before further clinical studies are started, problems with N-acetylcysteine and coagulation have to be elucidated in order to find out whether N-acetylcysteine could have a beneficial effect in the treatment of ARDS.

Plasma prekallikrein as a prognostic indicator in chronic liver insufficiency.

The prognostic value of plasma prekallikrein activity, prothrombin time, and serum albumin with regard to survival in chronic liver insufficiency was evaluated in 21 consecutive patients. Twenty patients had liver cirrhosis, and one patient had malignant liver disease (hepatocellular carcinoma). Eight patients died between 4 and 43 days after the time of blood sampling. These patients had a prekallikrein value less than 0.42. There were no overlapping prekallikrein values between patients who died and patients who survived (overlap index 0; p less than 0.001). Overlap index for prothrombin time was 0.35 (p less than 0.02), and for serum albumin 0.34 (p less than 0.02). In conclusion, plasma prekallikrein seems to indicate whether death is imminent in patients with liver insufficiency due to cirrhosis. Longitudinal studies of prekallikrein activity in different subgroups of patients with chronic and acute liver disease are recommended.

Laboratory aid in the diagnosis of acute appendicitis. A blinded, prospective trial concerning diagnostic value of leukocyte count, neutrophil differential count, and C-reactive protein.

The diagnostic value of C-reactive protein (CRP), total white blood cell (WBC) count, total neutrophil count, and neutrophil differential count were evaluated in a prospective blinded study of 204 patients submitted with the tentative diagnosis of acute appendicitis. The laboratory tests were performed on blood samples obtained at the time of admission, and the results were stored until the patients were discharged. One hundred patients were operated on: 59 had appendicitis, 3 had other surgically correctable diseases, and 38 had a superfluous exploration. All 104 nonoperated patients recovered spontaneously. The sensitivity, specificity, and predictive values of single tests and test combinations were calculated at different cutoff levels. Using standard reference intervals, WBC count demonstrated the best sensitivity (83 percent) and predictive value of a negative result (88 percent). Combining the tests by an "or" rule enhanced the sensitivity to 100 percent, employing WBC count or CRP or neutrophil percentage above the reference range (triple test), but at the expense of the predictive value of a positive test (37 percent). It was concluded that both single tests and combined tests are of limited value in predicting acute appendicitis. However, the same triple test combination proved a predictive value of a negative result at 100 percent (95 percent confidence limits 92 to 100 percent), indicating that acute appendicitis is unlikely when these tests are simultaneously negative. The triple test combination was valid in 32 percent of the patients who were free from appendicitis. In the study group, 10 of the patients (25 percent) who had a superfluous exploration had a negative triple test, and they might have avoided surgery if it had been used. Therefore, the triple test is recommended as a help in reducing the significant rate of negative laparotomies in patients suspected of having acute appendicitis.

ARDS after accidental inhalation of zinc chloride smoke.

Five soldiers were injured by inhalation of hexite smoke (ZnCl2) during military training. Two soldiers, not wearing gas masks breathed hexite for 1 or 2 min, they slowly developed severe adult respiratory distress syndrome (ARDS) over the ensuing 2 weeks. This slow, progressive clinical course has not been previously described. In both patients, an increased plasma zinc concentration was measured 3 weeks after the incident. Intravenous and nebulized acetylcysteine increased the urinary excretion of zinc, and briefly decreased the plasma levels. In an attempt to arrest collagen deposition in the lungs, L-3,4 dehydroproline was administered. Both patients died of severe respiratory failure (25 and 32 days after inhalation). At autopsy diffuse microvascular obliteration, widespread occlusion of the pulmonary arteries and extensive interstitial and intra-alveolar fibrosis was observed. Three soldiers wearing ill fitting gas masks, immediately developed severe coughing and dyspnea. They improved, and 12 months after exposure their lung function tests were nearly normal, but they still had slight dyspnea on exercise.

Rhesus immunization after Rh-incompatible kidney transplantation.

Rh-immunization of a male recipient was observed following the transplantation of two kidneys from Rh-pos donors. Immunosuppression consisted of azathioprine, prednisone and antilymphocyte globulin (1st transplantation) and cyclosporin A and prednisone (2nd transplantation). The immunization was probably caused by the residual blood in the cadaver kidneys. The use of cyclosporin A might increase the risk of Rh-immunization.