Treatment outcome in endodontics: the Toronto Study. Phase 1: initial treatment

This study assessed the 4- to 6-yr outcome of initial endodontic treatment during Phase 1 of the "Toronto Study" project. A total of 450 teeth were treated, alternating the "Schilder" technique and step-back with lateral condensation, and examined clinically and radiographically by an independent examiner. Apical periodontitis was recorded as absent (periapical index < 3) or present (periapical index > or = 3) and outcome dichotomized as "healed" (no apical periodontitis, no signs or symptoms) or "disease." Univariate, bivariate, and multivariate analyses were performed (p = 0.05) on 120 examined teeth. The "healed" rate (81% overall) was significantly higher for teeth treated without apical periodontitis (92%) than with apical periodontitis (74%). Several other factors were associated with healing rate differential of 10% or higher, but no statistical significance. This study confirmed apical periodontitis as the main prognostic factor in initial endodontic treatment. Continuation of the project will allow assessment of other prognostic factors with better power.     

The hemolytic and cytotoxic properties of a zeolite-containing root filling material in vitro

OBJECTIVE: This in vitro study characterized the hemolysis and cytotoxicity of ZUT, an experimental glass ionomer cement (GIC) sealer with an added antimicrobial-containing zeolite (0.2% Zeomic w/w). STUDY DESIGN: ZUT, Ketac-Cem (GIC component of ZUT), Ketac-Endo, and two AH 26 sealer formulations were tested at various times after mixing. Hemolysis produced by standardized specimens was determined spectrophotometrically (n = 6/material). Cytotoxicity was assessed by using a Millipore Filter test with a HeLa cell monolayer (n = 10/material). Tests were repeated, and results were analyzed with a one-way analysis of variance (alpha = .05). RESULTS: Disks of AH 26 containing silver produced the most hemolysis of all test groups (P < .0001). Compared to controls, GICs and AH 26 formulations were noncytotoxic at 1 and 6 hours after mixing, respectively (P > .05). Addition of Zeomic did not increase the cytotoxic and hemolytic activity of Ketac-Cem (P > .05). CONCLUSION: Overall results suggest ZUT is less cytotoxic than AH 26 and possesses characteristics similar to the other GIC formulations tested.     

Periapical inflammation affecting coronally-inoculated dog teeth with root fillings augmented by white MTA orifice plugs

Placement of orifice plugs has been suggested to augment the seal of conventional root canal fillings. This study assessed in vivo the efficacy of white mineral trioxide aggregate (MTA) plugs in preventing periapical inflammation subsequent to coronal inoculation of root-filled teeth. The two-rooted mandibular premolars of six beagle dogs were conventionally prepared and filled with gutta-percha and sealer. A white MTA orifice plug was placed into one canal in each tooth. Pulp chambers were inoculated with plaque except for 12 teeth (negative control), and restored. Radiographs were taken at regular intervals. At 10 months, dogs were killed and jaw blocks processed for histology. None of the roots revealed radiographic or histologic evidence of severe inflammation. Mild inflammation was observed in 17% and 39% of the roots with and without an orifice plug, respectively (McNemar, p > 0.05). Without development of severe inflammation, the seal augmentation efficacy of MTA orifice plugs could not be determined.     

Increased emotional distress in daughters of breast cancer patients is associated with decreased natural cytotoxic activity,elevated levels of stress hormones and decreased secretion of Th1 cytokines

DBCP who are aware of their increased risk of developing breast cancer may suffer from high emotional distress. Chronic stress may interfere with NCA and low NCA is associated with increased cancer risk. We studied 80 DBCP and 47 age- and education-matched healthy females (controls). Heparinized venous blood (30 ml) was drawn from all subjects between 8 and 9 A.M., and each participant answered a set of psychologic questionnaires. In addition, the first-morning urine sample was collected. DBCP scored significantly higher in emotional distress compared to controls. Levels of stress hormones in DBCP were higher and in vitro secretion of IL-2, IL-12 and IFN-gamma lower compared to controls. NCA against NK-resistant (MCF-7, COLO-205, U937) and NK-sensitive (K562) cell lines was significantly lower in DBCP and much less augmented by in vitro preincubation with IL-2 or IL-12 compared to controls. NCA and in vitro Th1 cytokine secretion were inversely correlated with the degree of emotional distress and the level of stress hormones in blood or urine. High emotional distress and elevated levels of stress hormones are associated with impaired immune surveillance functions in DBCP. This may contribute to the increased risk of DBCP to develop breast cancer. An interventional trial to enhance coping and reduce stress levels may help to decrease the risk for breast cancer onset in DBCP.     

Exercise-induced symptomatic ischaemia predicts a poor long-term prognosis after acute myocardial infarction

STUDY OBJECTIVES: To evaluate the long-term prognostic significance of symptomatic ischaemia during exercise testing performed 3 weeks after acute myocardial infarction (AMI). DESIGN: A prospective study with long-term follow-up. SETTING: A Cardiac Rehabilitation Clinic in a University Hospital. SUBJECTS: A total of 446 patients were allowed to perform exercise testing 3 weeks after AMI and followed for 72 +/- 20 months. MEASUREMENTS AND RESULTS: Patients were divided into three groups according to whether they had no ECG evidence of ischaemia during exercise testing (334 patients), silent ischaemia (90 patients) or symptomatic ischaemia (22 patients). Cardiac death was significantly more frequent in patients with symptomatic ischaemia when compared with silent ischaemia (31.8% vs. 7.8%, P < 0.01) or when compared with no ischaemia (31.8% vs. 10.2%, P < 0.01). The three groups had a low cardiac mortality during the first 48 months of follow-up. The prognosis of patients with symptomatic ischaemia worsens markedly thereafter. The results of exercise testing did not predict recurrence of myocardial infarction. Coronary revascularization was performed in 34.4% of those without ischaemia, 47.8% of those with silent ischaemia and 45.5% of those with symptomatic ischaemia (P < 0.01). CONCLUSIONS: Patients with symptomatic ischaemia have a good prognosis during the first 4 years of follow-up. Their prognosis worsens thereafter as opposed to patients with or without silent ischaemia. This high-risk group of patients with symptomatic ischaemia deserves optimal management including revascularization when appropriate.     

Use of the albumin/creatinine ratio to detect microalbuminuria: implications of sex and race

The recommended albumin (microg)/creatinine (mg) ratio (ACR) (30 microg/mg) to detect microalbuminuria does not account for sex or racial differences in creatinine excretion. In a nationally representative sample of subjects, the distribution of urine albumin and creatinine concentrations was examined by using one ACR value (> or =30 microg/mg) and sex-specific cutpoints (> or =17 microg/mg in men and > or =25 microg/mg in women) measured in spot urine specimens. Mean urine albumin concentrations were not significantly different between men and women, but urine creatinine concentrations were significantly higher (P < 0.0001). Compared with non-Hispanic whites, urine creatinine concentrations were significantly higher in non-Hispanic blacks (NHB) and Mexican Americans, whereas urine albumin concentrations were significantly higher in NHB (P < 0.0001) but not Mexican Americans. When a single ACR is used, the prevalence of microalbuminuria was significantly lower among the men compared with women (6.0 versus 9.2%; P < 0.0001) and among non-Hispanic whites compared with NHB (7.2 versus 10.2%; P < 0.0001). No significant difference in the prevalence of microalbuminuria between men and women was noted when sex-specific ACR cutpoints were used. In the multivariate adjusted model, female sex (odds ratio, 1.62; 95% confidence interval, 1.29 to 2.05) and NHB race/ethnicity (odds ratio, 1.34; 95% confidence interval, 1.12 to 1.61) were independently associated with microalbuminuria when a single ACR threshold was used. When a sex-specific ACR was used, NHB race/ethnicity remained significantly associated with microalbuminuria but sex did not. The use of one ACR value to define microalbuminuria may underestimate microalbuminuria in subjects with higher muscle mass (men) and possibly members of certain racial/ethnic groups.     

Abnormal protein phosphorylation in post-mortem brain tissue from bipolar patients

Summary. Abnormal phosphorylation has been proposed to be involved in the pathogenesis of affective disorders. The present study investigated basal and cAMP-stimulated endogenous protein phosphorylation in human post-mortem brain tissue from bipolar and schizophrenic patients. Furthermore, basal kinase activity and stimulated protein kinase A activity were measured. The frontal and occipital cortex were analysed. Using [γ-³²P]ATP as phosphate donor, basal and cAMP-stimulated phosphorylation of endogenous proteins was measured in the absence or presence of 8-Br-cAMP, respectively. The proteins were separated on SDS-gels and the radioactivity in the individual bands was measured. We observed a significant reduction of ³²P incorporation in three protein substrates (15, 16 and 21 kD) in frontal cortex of bipolar patients. However, there were no differences in the PKA activity between any of the groups. The present study demonstrates abnormal phosphorylation of specific proteins in brain tissue obtained from bipolar patients in comparison to schizophrenics and controls. Received November 27, 1998; accepted September 2, 1999