A comparison of bond strengths of complete crowns using two types of cements and three cleaning agents

In the past, biomechanical investigations on the dorsal pelvic ring have generally been performed on a small number of cadaveric pelves in various non-standardized procedures. Significant differences in stability between different internal fixation methods of unstable pelvic ring fractures were not found. The experimental design presented here was based as closely as possible on the physiological loading of the pelvis in one-leg stance. This method made it possible to carry out standardized, reproducible tests on different osteosytheses of the sacroiliac joint. Furthermore, the suitability of artificial bones for such investigations can be assessed on the basis of a larger number of similar experiments on artificial and human pelves and the number of human pelves required for such studies could be reduced.     

The rate of CD4 decline as a determinant of progression to AIDS independent of the most recent CD4 count. The Italian Seroconversion Study

Horse liver alcohol dehydrogenase contains two tryptophan residues per subunit, Trp-15 on the surface of the catalytic domain and Trp-314 buried in the interface between the subunits of the dimer. We studied the contributions of the tryptophans to fluorescence and catalytic dynamics by substituting Trp-314 with a leucine residue and making two compensatory mutations that were required to obtain a stable protein, leading to the triple mutant M303F-L308I-W314L enzyme. The substitutions increased by two- to sixfold the turnover numbers for ethanol oxidation, acetaldehyde reduction, and the dissociation constants of the coenzymes. The rate of the exponential burst phase for the transient oxidation of ethanol increased slightly, but the rate of dissociation of the enzyme-NADH complex still limited turnover of ethanol, as for wild-type enzyme. The three substitutions at the dimer interface apparently activate the enzyme by allowing more rapid conformational changes that accompany coenzyme binding, probably due to movement of the loop containing residues 293 to 298. The emission spectrum of M303F-L308I-W314L enzyme, which contains Trp-15, was redshifted compared to wild-type enzyme. Time-resolved fluorescence measurements with the triple mutant show that the decay of Trp-15 is dominated by a approximately 7-ns component. In the mutant enzyme with Trp-15 substituted with phenylalanine, the decay of Trp-314 is dominated by a approximately 4-ns component. Solute quenching data for wild-type enzyme and the mutants show that only Trp-15 is exposed to iodide and acrylamide, whereas Trp-314 is inaccessible. The luminescence properties of the tryptophan residues in the mutated enzymes are consistent with conclusions from studies of the wild-type enzyme [M. R. Eftink, 1992, Adv. Biophys. Chem. 2, 81-114].     

Coronary artery fistula after cardiac transplantation

A cardiac transplant recipient with multiple coronary artery fistulae draining into the right ventricle is described. These fistulae presumably resulted from repeated endomyocardial biopsies. The diagnosis of coronary artery fistulae was made at the annual coronary arteriography. The magnitude of the shunt remained small over eight years of follow-up.     

Increased mortality after successful treatment for Hodgkin's disease

PURPOSE: To determine the impact of treatment toxicity on long-term survival in pediatric Hodgkin's disease. PATIENTS AND METHODS: We studied late events in 387 patients treated for pediatric Hodgkin's disease on four consecutive clinical trials at St Jude Children's Research Hospital from 1968 to 1990. Relative risks, actuarial risks, and absolute excess risks for cause-specific deaths were calculated. RESULTS: As of April 1997, 316 (82%) of patients were alive, with a median follow-up of 15.1 (range, 2.9 to 28.6) years. In this cohort, which represented 5,623 person-years of follow-up, 71 fatal events resulted from Hodgkin's disease (n=36), second malignancies (n=14), infections (n=7), accidents (n=7), cardiac disease (n=6), and asphyxiation (n=1). The 5-year estimated event-free survival (EFS) for the entire cohort was 79.6%+/-2.1 %, which declined to 63.1%+/-4.4% by 20 years. Cumulative incidences of cause-specific deaths at 25 years were 9.8%+/-1.6% for Hodgkin's disease, 8.1%+/-2.6% for second malignancy, 4.0%+/-1.8% for cardiac disease, 3.9%+/-1.5% for infection, and 2.1%+/-0.8% for accidents. Standardized incidence ratios showed excess risk for all second malignancies (12; 95% confidence interval [CI], 8 to 17), acute myeloid leukemia (81; 95% CI, 16 to 237), solid tumors (11; 95% CI, 7 to 16), and breast cancer (33; 95% CI, 12 to 72). Standardized mortality ratios also showed excess mortality from cardiac disease (22; 95% CI, 8 to 48) and infection (18; 95% CI, 7 to 38). CONCLUSION: Compared with age- and sex-matched control populations, survivors of pediatric Hodgkin's disease who were treated before 1990 face an increased risk of early mortality related to second cancers, cardiac disease, and infection.     

Juvenile Tillaux fracture simulating syndesmosis separation: a case report

Determination of proliferative activity of non-Hodgkin's lymphomas (NHL), aimed at improving the prediction of their clinical behavior, has gained considerable attention in the recent years. Flow cytometry has allowed rapid measurement of the cellular DNA content in terms of ploidy and proliferative activity. Flow cytometric DNA analysis was performed on paraffin embedded biopsy specimens taken from 125 patients with NHL. In 90 of them, proliferative index (PI) could be accurately measured and correlated with histology grade of the Working Formulation (WF). Intermediate and high grade NHL (54 patients) were analyzed together as HG-NHL. With the discrimination point for PI of 10%, the survival of high and low proliferative lymphomas was compared in the whole NHL group and within the WF prognostic groups. The median PI was 5% in LG (low grade) NHL and 10% in HG (high grade) NHL group. Acturial survival in NHL with high proliferative activity (39 patients) was 31% at 5 years and 15% at 10 years, and in NHL with low proliferative activity (51 patients) 53% and 18%, respectively (p = 0.002). In HG-NHL, survival at 5 years for low proliferative cases was 55% and for high proliferative cases 28% (p = 0.065), whereas in the LG-NHL group it was 54% and 28%, respectively (p = 0.059). The survival at 10 years was nearly equal in all groups. Proliferative index was associated with the overall survival of NHL in the whole group, as well as within the LG and HG prognostic categories. PI could differentiate more and less aggressive NHLs both within LG-NHL and HG-NHL. A tendency of survival curves toward continuous relapse was observed in low proliferative NHL and a tendency toward "plateau" in high proliferative NHL, irrespective of the histology grade.     

Orthopaedic surgery in hemophilic patients with human immunodeficiency virus

Patients registered at the author's hemophilia center between 1982 and 1994 were studied to establish whether major orthopaedic surgical procedures accelerate the fall of CD4 lymphocyte counts of patients with hemophilia who are infected with the human immunodeficiency virus, and whether patients who had surgery had different rates of development of acquired immune deficiency syndrome or death when compared with patients who did not have surgery. The patients were divided into four groups: Group 1, 22 patients who were human immunodeficiency virus positive undergoing orthopaedic surgery; Group 2, 89 patients who were human immunodeficiency virus positive not undergoing orthopaedic surgery; Group 3, 18 patients who were human immunodeficiency virus negative undergoing orthopaedic surgery; and Group 4, 135 patients who were human immunodeficiency virus negative not undergoing orthopaedic surgery. There was no significant difference between the rates of decline of CD4 lymphocyte counts for patients who were human immunodeficiency virus positive who underwent surgery when compared with human immunodeficiency virus positive patients who did not undergo surgery, nor was there any significant difference between the two human immunodeficiency virus negative groups. There were no significant differences in the rate of development of acquired immune deficiency syndrome or mortality rates between patients who had surgery and those who did not.     

Intracranial and spinal dissemination of an ACTH secreting pituitary neoplasia. Case report and review of the literature

Smoking is associated with insulin resistance, dyslipidaemia and markers of the insulin resistance syndrome. This study investigated adipose tissue lipolysis in situ by subcutaneous microdialysis twice in 10 healthy, male smokers after smoking four cigarettes over 2 h and after the administration of an equal amount of nicotine given as nasal spray (NNS). Glucose and insulin levels, in situ lipolysis and adipose tissue blood flow were studied in the post-absorptive state and after a 75-g oral glucose tolerance test (OGTT). Post-absorptively, acute smoking and NNS increased neither subcutaneous adipose tissue glycerol production nor plasma free fatty acid (FFA) or glycerol levels. After the OGTT, plasma insulin and lactate levels were significantly higher after smoking, whereas FFA levels were higher after NNS. Normal smoking or the administration of a normal dose of NNS caused only minor metabolic changes. Thus, it does not seem likely that increased lipolysis is an important contributor to the dyslipidaemia seen in smokers.     

Visual accommodation and virtual images: do attentional factors mediate the interacting effects of perceived distance, mental workload, and stimulus presentation modality?

A study was conducted to examine the effect on the visual accommodation response of processing information presented either visually or aurally while viewing a real-world scene. A number of different conditions were tested in which a mental processing task, a virtual image overlaying the real world (as is the case with head-up displays), or both were present. These manipulations provided two factors that have previously been demonstrated to have some influence on the accommodation response: mental effort and perceived distance. They also allowed the investigation of the influence of the source modality of the information to be processed. The results suggested that these influences may have a cumulative effect on the visual accommodation response, possibly mediated by attentional factors.