Screening test for decompression sickness

The fibrin-fibrinogen degradation products (FDP) tests were studied in 18 patients having a history of illness associated with diving. FDP tests were performed prior to hyperbaric oxygen therapy (OHP). Eight patients were serious neurologic signs had positive FDP tests and required repetitive therapy. Six patients had negative FDP tests with local musculoskeletal complaints and all were asymptomatic following the first OHP treatment. Three patients were found to be suffering from other diseases. These three patients had normal levels of FDP. One patient treated at another facility 3 months earlier and having paraplegia had a positive FDP test. Serious decompression sickness with neurologic complaints appear to have some degree of disseminated intravascular coagulation (DIC) as reflected by the FDP tests. The FDP test appears to be a useful screening test that may be able to delineate therapy.     

Prostatic acid phosphatase. Current assessment in vaginal fluid of alleged rape victims

Although elevated prostatic acid phosphatase activity (ACP) in vaginal fluid is compatible with recent coitus, the finding of spermatozoa in vaginal fluid is usually considered the diagnostic indicator for semen. When 80 alleged rape cases during an 18-month period were reviewed and the results of cytologic examination for the presence of spermatozoa compared with quantitative ACP determinations, the latter appeared to be a more reliable and sensitive indicator of semen. The normal range of ACP in semen, as well as persistence of ACP in vaginal fluid, was also defined. It is concluded that vaginal fluid ACP is a reliable and sensitive method for identification of semen. Furthermore, the results confirm that quantitative ACP determination of vaginal fluid specimens may substantiate the allegation of rape with respect to time.     

Computer-controlled endoscopic performance assessment system

We have devised an advanced computer-controlled system (ADEPT) for the objective evaluation of endoscopic task performance. The system's hardware consists of a dual gimbal mechanism that accepts a variety of 5.0-mm standard endoscopic instruments for manipulation in a precisely mapped and enclosed work space. The target object consists of a sprung base plate incorporating various tasks. It is covered by a sprung perforated transparent top plate that has to be moved and held in the correct position by the operator to gain access to the various tasks. Standard video endoscope equipment provides the visual interface between the operator and the target-instrument field. Different target modules can be used, and the level of task difficulty can be adjusted by varying the manipulation, elevation, and azimuth angles. The system's software is designed to (a) prompt the surgeon with the information necessary to perform the task, (b) collect and collate data on performance during execution of specified tasks, and (c) save the data for future analysis. The system was alpha and beta tested to ensure that all functions operated correctly.     

Effects of blood flow pulse frequency on mass transfer efficiency of a commercial hollow fibre oxygenator

The clinical advantages achievable through pulsatile blood perfusion during cardio-pulmonary bypass have recently suggested the design of new pulsatile systems for extracorporeal circulation. Still it is not clear whether current commercial membrane oxygenators could be adopted with such systems, since their behaviour with pulsatile perfusion has not been satisfactorily documented yet. In a previous paper, we assessed that pulsatile perfusion of a widely used hollow fibre oxygenator (Sorin Monolyth) at 60 bpm provides more time-consistent oxygen transfer than steady perfusion. The present work is aimed to evaluate how the pulse frequency influences the gas transfer performance of the same device. The oxygenator was subjected to in vitro trials using a roller pump with pulsatile module (Stockert Instrumente) to generate pulsed flow. Four different pulse frequencies (45, 60, 75 and 90 bpm) were investigated at a fixed blood flow rate (4.0 l/min). The experiments lasting six hours were carried out using bovine blood with inlet conditions according to AAMI standards requirements. Blood samples were withdrawn every hour and O2 and CO2 transfer rates were evaluated. The experimental findings confirm that with pulsatile blood flow no time decay take place during prolonged perfusion. Moreover, when pulse frequency increases, transition levels occur for both O2 and CO2. Over these thresholds gas transfer rates display significant increases (p < 0.05), though of little magnitude (up to 2.5% for oxygen over 60 bpm; up to 3.7% for carbon dioxide over 75 bpm).     

Morphological features and healing of stress ulcers induced by alcohol and restraint

Gastric mucosal damage was produced in 130 mice by forced ingestion of alcohol, followed by restraint in the cold. Animals were killed at intervals from six hours to 27 days following the stress. Linear hemorrhagic erosions and diffuse hemorrhagic patches were found grossly, predominantly in the glandular portion of the stomach, in about 75% of the animals 6 to 24 hours after stress. At later time intervals, the linear mucosal depressions persisted; these became progressively less prominent with time but substantial numbers were still readily discernible three weeks after injury. Microscopical examination of the fresh lesions showed a variable amount of mucosal necrosis and acute inflammation. Epithelial regeneration became prominent after three days and persisted for several weeks. The first regenerating epithelial cells were primitive, cuboidal elements followed by mucous cells, parietal cells, and zymogen cells, in that order. The morphological features and evolution of the lesions were similar to that described in human stress ulcers.     

Effect of urea form and method of feeding on rumen ammonia concentration

Rumen ammonia was compared in six rumen fistulated, lactating Holstein cows fed urea twice daily in a concentrate mixture, urea fed once per day in a complete ration, and a gelatinized starch-urea product fed twice daily in the concentrate mixture. Samples were taken during 24-h intervals at the end of each 3 wk. Sharp and similar peaks in rumen ammonia followed feeding of urea and gelatinized urea-starch product twice daily in the concentrate mixture. A much lower ammonia peak followed the once daily feeding of the complete ration. Use of complete rations offered ad libitum eliminates the need for products with sustained ammonia release.     

The Use of Dynamic Mechanical Methods to Study the Effect of Absorbed Water on Temperature-dependent Properties of an Epoxy Resin-Carbon Fibre Composite

Dynamic mechanical methods were used to study the effect of absorbed moisture on the properties of an epoxy resin matrix CFRP. The glass transition temperature (T_g)of the matrix resin, determined as the onset of the characteristic fall in dynamic modulus with increasing temperature, was found to decrease with increasing moisture content. Maximum shifts in T_g of 80 to 90°C, relative to the dry material, were observed for a resin moisture content of 5.2% by weight. The effects of sample geometry, fibre orientation, and frequency of oscillation, on the dynamic mechanical properties are discussed. Results are given of an analysis of the observed dependence of T_g on water content using two theoretical models.