The layman's view of orthodontics: a literary review

It is probably true to say that the masticatory apparatus attracts proportionally greater attention than any other part of the body. Evidence that this is so is provided, not only by the degree of specialisation within the dental profession, but by the frequency with which references to teeth and dentistry crop up in literature. Generations of biographers, novelists, poets, playwrights and essayists have written about their dental experiences and included the dentition in describing the facial appearance of characters, factual and fictional. The literary extracts in this article, culled from an extensive collection, refer to orthodontics. They provide a fascinating insight into the patient's perspective on that speciality and make entertaining reading.     

Increased oxidative damage is correlated to altered mitochondrial function in heterozygous manganese superoxide dismutase knockout mice

This study characterizes mitochondria isolated from livers of Sod2(-/+) and Sod2(+/+) mice. A 50% decrease in manganese superoxide dismutase (MnSOD) activity was observed in mitochondria isolated from Sod2(-/+) mice compared with Sod2(+/+) mice, with no change in the activities of either glutathione peroxidase or copper/zinc superoxide dismutase. However, the level of total glutathione was 30% less in liver mitochondria of the Sod2(-/+) mice. The reduction in MnSOD activity in Sod2(-/+) mice was correlated to an increase in oxidative damage to mitochondria: decreased activities of the Fe-S proteins (aconitase and NADH oxidoreductase), increased carbonyl groups in proteins, and increased levels of 8-hydroxydeoxyguanosine in mitochondrial DNA. In contrast, there were no significant changes in oxidative damage in the cytosolic proteins or nuclear DNA. The increase in oxidative damage in mitochondria was correlated to altered mitochondrial function. A significant decrease in the respiratory control ratio was observed in mitochondria isolated from Sod2(-/+) mice compared with Sod2(+/+) mice for substrates metabolized by complexes I, II, and III. In addition, mitochondria isolated from Sod2(-/+) mice showed an increased rate of induction of the permeability transition. Therefore, this study provides direct evidence correlating reduced MnSOD activity in vivo to increased oxidative damage in mitochondria and alterations in mitochondrial function.     

Current options in prosthetic vascular graft infection

Debate continues over which procedure is the best treatment for prosthetic graft infections. We retrospectively reviewed the medical records at our institution for all vascular graft infections that occurred from 1985 to 1995 to evaluate their occurrence, treatment, and outcome. Twenty-four patients had prosthetic graft infections. The average patient age was 62 years, and 67 per cent of the patients studied were men. The initial operation was for treatment of occlusive disease in 92 per cent of the patients, and aortofemoral bypasses were the most common procedures performed (15 of 24 patients, 63%). The average interval from graft implantation to presentation of infection was 29 months. In lower-extremity bypasses, the site of infection was most commonly in the groin (87%). Gram-positive organisms, including coagulase-negative Staphylococcus (32%) and Staphylococcus aureus (28%), were the most frequently isolated bacteria. Thirty procedures were performed for management of the graft infections. Extra-anatomic bypass was associated with no recurrent graft infections. Graft preservation was successful in two cases of early S. aureus infection (less than 1 year after original procedure), and in situ graft replacement was successful in all four cases of late-appearing coagulase-negative Staphylococcus infection (more than 1 year after original procedure). Both treatments failed in all five cases of Gram-negative infection (P = 0.008 by Fisher's exact test). The overall mortality and amputation rates were 17 per cent and 21 per cent, respectively, without significant differences between the treatment modalities. Extra-anatomic bypass remains the best treatment for prosthetic graft infection. In situ replacement and graft preservation treatments should be selective and based on presentation of the infection and the type of pathogenic organism.     

Transthyretin amyloidosis: a new mutation associated with dementia

NaCl-tolerant lactic acid bacteria (LAB) strains LC-10 (Lactobacillus casei) and LP-15 (Lact. plantarum) and NaCl were used as additives to sorghun (Sorghum bicolor). Numbers of LAB were significantly (P < 0.05) higher in all the additive-treated silages than in the control silage at an early stage of ensiling. During the fermentation process, addition of NaCl or LAB effectively inhibited the growth of aerobic bacteria and clostridia, but not yeasts. All the additive-treated silages had significantly (P < 0.05) lower pH, ammonia nitrogen content, dry matter loss and gas production but significantly (P < 0.05) higher lactic acid content and residual water soluble carbohydrates compared with the control silage. The improvement in silage quality was in the order: LAB > NaCl > control. Yeast counts were high in all additive-based silages and they increased during the exposure of the silages to air. As a result, these silages suffered aerobic deterioration, whereas the control silage was stable. The results confirmed that the NaCl or LAB improved fermentation quality but did not prevent aerobic deterioration of the silage.     

Flow beyond an isolated rotating diskEcoulement autour d'un disque tournant isoledie strömung hinter einer isolierten rotierenden scheibeOбтeкaниe изoлиpoвaннoгo бpaщayщeгocя диcкa

Visualization and flow measurements were performed for the flow field radially beyond the rims of isolated flat circular disks rotating in their own planes. The investigation included effects of disk thickness and speed of rotation. Flow in the near-rim region has similarities to that of the near-wake region of bluff-tailed bodies, with vortices being found there. In the same region there is a large negative radial gradient of whirl velocity. Further from the disk rim the flow becomes a jet with straight mean streamlines. The relative degree of swirl in the far-jet varies with disk thickness and speed.     

Simplified Model for Assessing Meander Bend Migration Rates

This paper describes a simple analytical model for assessing meander bend migration rates. The new model is innovative in that it can be applied directly using output data from one-dimensional hydraulic models. The method is designed as a first approximation that can be applied rapidly to large reaches of river systems, and should not be considered as a replacement for more detailed bank stability assessments. The model is based on a conversion factor for one-dimensional shear stress. Comparison of the conversion factor with existing data sets is presented. Converted shear stresses are translated to bank erosion volumes, which in turn are related to meander bend migration rates, using bank geometry and an appropriate sediment transport law. Results are presented for an evaluation of meander bend migration rates for a restoration feasibility study for a project on the Williamson River, Oregon.     

Studies on the time-course of ethanol''s acute effects on skeletal muscle protein synthesis: comparison with acute changes in proteolytic activity

The complexity of the spot patterns of two-dimensional electrophoresis gels made it necessary to use image processing techniques to analyze the gels. An important issue in the analysis is the detection and quantification of the protein spots. In this paper we describe a new technique to segment and model the different spots. For the segmentation of a gel into its different spot regions we apply a watershed technique, which is robust and efficient. For the quantification of the spots, a new spot model is constructed, based on diffusion principles. Besides the advantage of having a physical interpretation, the model is demonstrated to be superior to the commonly used Gaussian models.     

Complications of laparoscopic paraesophageal hernia repair

The complications of laparoscopic paraesophageal hernia repair at two institutions were reviewed to determine the rate and type of complications. A total of 76 patients underwent laparoscopic paraesophageal hernia repair between December 1992 and April 1996. Seventy-one of them had fundoplication (6 required a Collis-Nissen procedure). Five patients underwent hernia reduction and gastropexy only. There was one conversion to laparotomy. Traumatic visceral injury occurred in eight patients (11%) (gastric lacerations in 3, esophageal lacerations in 2, and bougie dilator perforations in 3). All lacerations were repaired intraoperatively except for one that was not recognized until postoperative day 2. Vagus nerve injuries occurred in at least three patients. Three delayed perforations occurred in the postoperative period (4%) (2 gastric and 1 esophageal). Two patients had pulmonary complications, two had gastroparesis, and one had fever of unknown origin. Seven patients required reoperation for gastroparesis (n = 2), dysphagia after mesh hiatal closure of the hiatus (n = 1), or recurrent herniation (n = 4). There were two deaths (3%): one from septic complications and one from myocardial infarction. Paraesophageal hernia repair took significantly longer (3.7 hours) than standard fundoplication (2.5 hours) in a concurrent series (P <0.05). Laparoscopic paraesophageal hernia repair is feasible but challenging. The overall complication rate, although significant, is lower than that for nonsurgically managed paraesophageal hernia.