Improved teleradiology reporting using fax software

OBJECTIVE: In an effort to expedite after-hours teleradiology reports in an efficient and accurate manner with minimal usage of manpower, we have for the past 4 years used commercially available fax software running on a laptop computer placed beside the home-based teleradiology system. The software and laptop combination allows the radiologist to make a report rapidly by typing brief sentences in a fillable field or by selecting an applicable pretyped report from a menu. The report is then electronically faxed to single or multiple sites with a single mouse click. CONCLUSION: The system has drastically reduced the number of telephone calls between technologists and teleradiologists and has been well received by both technologists and emergency department staff and referring physicians.     

Laparoscopic virtual reality training: are 30 repetitions enough?

BACKGROUND: Current literature suggests that novices reach a plateau after two to seven trials when training on the MIST VR laparoscopic virtual reality system. We hypothesize that significant benefit may be gained through additional training. MATERIALS AND METHODS: Second-year medical students (n = 12) voluntarily enrolled under an IRB-approved protocol for MIST VR training. All subjects completed pre- and posttraining questionnaires and performed 30 repetitions of 12 tasks. Performance data were automatically recorded for each trial. Learning curves for each task were generated by fitting spline curves to the mean overall scores for each repetition. Scores were assessed for plateaus by repeated measures, slope, and best score. RESULTS: On average, subjects completed training in 7.1 h. (range, 5.9-9.2). Two to seven performance plateaus were identified for each of the 12 MIST VR tasks. Initial plateaus were found for all tasks by the 8th repetition; however, ultimate plateaus were not reached until 21-29 repetitions. Overall best score was reached between 20 and 30 repetitions and occurred beyond the ultimate plateau for 9 tasks. CONCLUSIONS: These data indicate that a lengthy learning curve exists for novices and may be seen throughout 30 repetitions and possibly beyond. Performance plateaus may not reliably determine training endpoints. We conclude that a significant and variable amount of training may be required to achieve maximal benefit. Neither a predetermined training duration nor an arbitrary number of repetitions may be adequate to ensure laparoscopic proficiency following simulator training. Standards which define performance-based endpoints should be established.     

Hepatosplenic morbidity in two neighbouring communities in Uganda with high levels of Schistosoma mansoni infection but very different durations of residence

Peri-portal fibrosis can be a serious sequelae of Schistosoma mansoni infection. Age or duration of exposure have been identified as important risk factors, but their relative importance cannot be easily separated. Here, we have compared two cohorts, aged 6-50 years and resident for ten years or since birth, from two neighbouring villages (Booma and Bugoigo) on the eastern shore of Lake Albert, Uganda. Parasitological measurements were similar, whereas the prevalence of peri-portal fibrosis was 5-fold higher in Booma. Data from the cohorts were pooled to assess the relative contribution of age and duration of residency on the risk of disease. Amongst adults, duration of residency was the critical risk factor--individuals aged 17-31 years resident for more 22 years had an almost 12-fold increased risk of fibrosis than those resident for less than 15 years. Height-standardised Splenic Vein Diameter (SVD), Portal Vein Diameter (PVD), Para-sternal Liver Length (PLL) and Spleen Length (SL) values were all higher in Booma, and each organometric parameter except PLL increased with the severity of fibrosis. Our results clearly demonstrate that duration of exposure is a critical risk factor for the development of peri-portal fibrosis and its sequelae in adults. This parameter should therefore be a routine measurement during epidemiological surveys of S. mansoni.     

Y-26763: ATP-sensitive K+ channel activation and the inhibition of insulin release from human pancreatic beta-cells

The effect of Y-26763 [(-)-(3S,4R)-4-(N-acetyl-N-hydroxyamino)-6-cyano-3,4-dihydro-2,2-dimethyl-2H-1-benzopyran-3-ol], a novel ATP-sensitive K(+) (K(ATP)) channel activator, was tested on insulin secretion from human pancreatic islets in vitro. Y-26763 was able to inhibit both glucose- and tolbutamide-induced insulin secretion from islets as assessed by radioimmunoassay. The mechanism for inhibition of insulin secretion was characterised using patch clamp electrophysiology on dispersed human pancreatic beta-cells which express K(ATP) channels comprised of Kir6.2 and SUR1, and the NES2Y human beta-cell line, transfected with Kir6.2DeltaC26. Y-26763 activated K(ATP) channels in a reversible manner with a similar activity to diazoxide. This required the presence of hydrolysable nucleotides and appeared to be mediated by interaction of Y-26763 with SUR1 since: (a) tolbutamide was able to reverse the actions of Y-26763 and (b) Y-26763 failed to activate Kir6.2DeltaC26 in the absence of SUR1. We conclude that Y-26763-induced inhibition of insulin release is dependent upon the activation of K(ATP) channels in human beta-cells.     

Interpretation and optimization of the dissolution specifications for a modified release product with an in vivo-in vitro correlation (IVIVC)

This article considers the in vivo significance attached to in vitro dissolution testing. Almost invariably, the in vitro dissolution test is interpreted in terms of bioequivalence. The literature that describes methods for setting in vitro dissolution specifications is reviewed. The most common interpretation of these specifications is a deterministic one, that is, those batches passing the dissolution specifications would be bioequivalent with the reference if tested in vivo and those failing the dissolution specifications would not be bioequivalent if tested in vivo. Due to random variation, the deterministic interpretation is not appropriate. Instead, we need to consider the conditional probability that a batch that has passed the in vitro dissolution test would demonstrate bioequivalence if tested in vivo, and that a batch known to have failed the in vitro dissolution test would demonstrate bioinequivalence if tested in vivo. One way to estimate these probabilities is by means of a simulated experiment in which the production and testing (in vivo and in vitro) of a large number of batches is computer simulated. Such a simulation can only be performed if the relationship between the in vitro dissolution characteristics and the in vivo performance of the product has been modeled. These models are generally referred to as in vivo-in vitro correlations (IVIVC). The results of one such experiment are described. The above-mentioned conditional probabilities are shown to depend on the choice of dissolution specifications. This result leads to the notion of optimal dissolution specifications. However, both of the conditional probabilities cannot be maximized simultaneously. The probability of making a correct decision on the basis of the in vitro dissolution test is introduced as a possible optimality criterion. This probability is a linear combination of the two conditional probabilities of interest. Using this criterion, the optimal dissolution specifications can be found by searching over the multidimensional space defined by the half width of each interval used in the specifications to find the combination that maximizes this probability. This process is demonstrated using the Nelder-Mead search routine. The choice of dissolution specifications has profound implications for the routine production of the product because if the specifications were very narrow the probability of a batch passing would be low, resulting in a low hit rate. The same computer program used to perform the simulation experiment can be used to estimate the hit rate. Furthermore, it can be used to explore the magnitude of changes required in the parameters describing the test product (particularly variability) to increase a low hit rate to an acceptable level.     

The impact of infection on the incidence of autoimmune disease

Falling infection rates in the developed world are being matched by a rapidly rising incidence of allergic and autoimmune diseases. This review explores the hypothesis that there is a causal link between these phenomena and that infections can prevent the onset of autoimmune disease. The hypothesis is discussed with particular reference to Type I diabetes in the NOD mouse and the ability of the helminth infection Schistosoma mansoni to prevent its onset. The article addresses the possible mechanisms that underly this protection. The effects of protective pathogen-derived agents on key cells of the innate immune system such as dendritic cells are distinct and include the production of anti-inflammatory cytokines such as IL-10. The most likely mechanisms by which these innate changes prevent the subsequent adaptive autoimmune destruction are: (1) the production of systemically high levels of cytokines that oppose the production of cytokines that drive the autoimmune process - possibly via the action of natural killer T (NKT) cells (2) the induction of regulatory T cells that inhibit the action of autoreactive cells and (3) the production of pathogen-specific T cells that are not autoreactive and compete with autoreactive cells for survival signals such as cytokines and T cell receptor ligation.     

Radiosensitization of colon cancer cell lines by docetaxel: mechanisms of action

The radiation-modifying action of docetaxel in experimental systems is well established. Docetaxel is also an increasingly important drug for the treatment of cancer in concurrent radiotherapy protocols. However, the mechanisms of docetaxel radiosensitization are not fully understood. We have investigated the magnitude and mechanisms of docetaxel radiosensitization in vitro in four human colorectal cancer cell lines (SW480, SW707, SW48, and HT29) with widely differing radiosensitivities. Cell survival curves were generated for a range of docetaxel concentrations (5-20 nM) alone and for X-rays (1-5 Gy) +/- 10 or 20 nM docetaxel (for 24 h before irradiation). Cell cycle distributions and apoptotic frequencies were measured during the treatments. Sensitivity to docetaxel alone was similar in all cell lines and could be attributed to massive induction of apoptosis (60-80% by 24 h). Radiosensitivity varied widely; the surviving fractions at 2 Gy in the most resistant (HT29) and most sensitive (SW28) lines were 0.81 and 0.13, respectively. Exposure to 10 nM docetaxel induced a progressive accumulation of SW480, SW707, and SW48 cells in G2/M. After 24 h, 55-70% of the cells were in G2/M. It is likely, therefore, that accumulation in this radiosensitive phase of the cell cycle contributes significantly to radiosensitization by the drug.     

The relationship between porosity and fatigue characteristics of bone cements

In this study, the fatigue strengths of acrylic cement prepared by various commercially available reduced pressure mixing systems were compared with the fatigue strength of cement mixed by hand (control) under atmospheric conditions. The following observations were made from this investigation. The mean fatigue strength of reduced pressure mixed acrylic bone cement is double that of cement mixed by hand using an open bowl, 11,354+/-6,441 cycles to failure for reduced pressure mixing in comparison with 5,938+/-3,199 cycles for mixing under atmospheric conditions. However, the variability in mean fatigue strengths of reduced pressure mixed bone cement is greater for some mixing devices. The variation in fatigue strengths for the different mixing techniques is explained by the different porosity distributions. The design of the reduced pressure mixing system and the technique employed during mixing strongly contribute to the porosity distribution within the acrylic bone cement. The level of reduced pressure applied during cement mixing has an effect on the fatigue strength of bone cement, but the mixing mechanism is significantly more influential.     

Early patterns of sexual activity: age cohort differences in Australia

Patterns of first sexual activity among Australians born between the 1940s and 1980s were analysed using data from a national telephone survey of 1784 adults (876 males; 908 females). Sixty-one percent of those randomly selected from the Australian electoral roll and contactable by telephone responded. Many trends, including earlier first intercourse--from 20 to 18 years (females) and 18.8 to 17.8 years (males)--were established with the 40-49 year cohort, whose sexual debut was in the late 1960s-70s. Significant age-cohort effects saw women in the contemporary (18-29 year) cohort draw level with males for age at first intercourse and first sex before age 16 and before leaving school. First intercourse contraceptive use climbed from 30% to 80%. Condom use quadrupled to 70%. Australian age-cohort effects are remarkably consistent with those in similar western cultures: gender convergence in sexual experience and increasing avoidance of sexually transmitted disease and pregnancy. If such trends continue, positive long-term outcomes for health and social wellbeing should result.