Clinical and radiographic results with the Trilock femoral component--a wedge-fit porous ingrowth stem design

Eighty-one cementless Trilock (Depuy, Warsaw, IN) femoral components were observed for 2 to 6 years. The following end points were examined: revision (none), pain score less than 5 (six patients), and radiographic settling greater than 5 mm (three patients). Four patients (5%) had thigh pain at follow-up. No complete radiopaque lines could be identified around the porous surface of the femoral components. By any standard, the wedge-fit tapered cementless femoral design is successful. As the follow-up period lengthens, a survivorship analysis can be done to assess the long-term potential of the Trilock design.     

Nitroglycerin-inhibited whole blood aggregation is partially mediated by calcitonin gene-related peptide–a neurogenic mechanism

1. The role of the vasculature and calcitonin gene-related peptide (CGRP) in nitroglycerin (NTG)-mediated platelet inhibition was studied.
2. In vitro incubations of CGRP in whole blood induced a dose-dependent inhibition of platelet aggregation with an IC₅₀ of 62.1 nM.
3. The platelet inhibition induced by CGRP was blocked by co-incubation of 0.53 μM CGRP_8-37, as well as 30 μM N^G-nitro-monomethyl-L-arginine (L-NMMA).
4. In a separate group of experiments, 100 nM NTG in rat whole blood (WB) induced platelet inhibition of 6.0±1.3% (mean±s.d.), which was enhanced to 77.6±3.5% by the addition of rat aortic tissue (AT) (P<0.001). The inclusion of CGRP_8-37 with NTG and AT in WB reduced platelet inhibition to 31.6±6.8% (P<0.01). Incubation of WB and AT with 30 μM L-NMMA reduced NTG-induced inhibition of platelet aggregation to 26.4±4.2% (P<0.001).
5. It is concluded that vascular tissue contributes to the antiplatelet mechanism of action of NTG. Furthermore, NTG apparently evokes the release of CGRP from vascular tissue and this neuropeptide contributes to the antiplatelet actions of NTG.
6. The antiplatelet activity of CGRP in whole blood is mediated primarily through the activation of nitric oxide synthase.

     

Comparison of pitot traverses taken at varying distances downstream of obstructions

This study determined the deviations between pitot traverses taken under "ideal" conditions--at least seven duct diameter's lengths (i.e., distance = 7D) from obstructions, elbows, junction fittings, and other disturbances to flows--with those taken downstream from commonplace disturbances. Two perpendicular 10-point, log-linear velocity pressure traverses were taken at various distances downstream of tested upstream conditions. Upstream conditions included a plain duct opening, a junction fitting, a single 90 degrees elbow, and two elbows rotated 90 degrees from each other into two orthogonal planes. Airflows determined from those values were compared with the values measured more than 40D downstream of the same obstructions under ideal conditions. The ideal measurements were taken on three traverse diameters in the same plane separated by 120 degrees in honed drawn-over-mandrel tubing. In all cases the pitot tubes were held in place by devices that effectively eliminated alignment errors and insertion depth errors. Duct velocities ranged from 1500 to 4500 ft/min. Results were surprisingly good if one employed two perpendicular traverses. When the averages of two perpendicular traverses was taken, deviations from ideal value were 6% or less even for traverses taken as close as 2D distance from the upstream disturbances. At 3D distance, deviations seldom exceeded 5%. With single diameter traverses, errors seldom exceeded 5% at 6D or more downstream from the disturbance. Interestingly, percentage deviations were about the same at high and low velocities. This study demonstrated that two perpendicular pitot traverses can be taken as close as 3D from these disturbances with acceptable (< or = 5%) deviations from measurements taken under ideal conditions.     

Psychological influences on the perception of immune function

BACKGROUND: Perception of deficiencies in immunity are common in a number of patient complaints. However, little is known about the way in which individuals form perceptions about the competence of their immune system. In two studies we examined the relationship between subjects' perceptions of their immune functioning, physical symptoms, mood and measures of immunity. METHODS: In Study 1, 20 healthy volunteers completed global ratings of their immune system functioning, as well as mood and symptom reports, twice a week for 5 weeks. At the same time, blood samples were taken to assess serum IgA, IgG, and IgM antibodies. In Study 2, another sample of 58 subjects completed the same measures weekly for 5 weeks and their blood was tested for concentrations of CD3, CD4, CD8, and CD16 lymphocytes. RESULTS: We found perceptions of immune functioning to be unrelated to the concentrations of serum antibodies or blood lymphocytes. Immune perceptions were strongly related to mood and in particular, feelings of fatigue and vigour. The experience of recent physical symptoms, while not as strong as mood variables, was also important in perceptions of immune functioning. CONCLUSIONS: Mood seems to be an important determinant in the perception of immune function, and complaints about immune dysfunction in clinical situation should be investigated with this possibility in mind.     

Analytic performance of two automated nonpretreatment digoxin immunoassays

The analytic performance of two automated nonpretreatment digoxin methods, AxSYM Digoxin II and Vitros digoxin immunoassays, was assessed. Both assays had analytic sensitivities of less than 0.2 microg/L, were linear from digoxin concentrations of 0.5 to 4.0 microg/L, and showed acceptable precision, with a maximum total coefficient of variation (CV) of 8.9% and 6.4% for the AxSYM and Vitros, respectively. Comparison of the two methods using samples from patients receiving digoxin gave the following relationship: Vitros = 0.91 x AxSYM + 0.23 (r = 0.97, Sy,x = 0.12). Digoxinlike immunoreactive factor (DLIF) crossreactivity was examined in specimens from patients who had hepatic disease, renal insufficiency, had undergone cardiac surgery, and in neonatal cord blood samples. Minimal crossreactivity was observed for most samples and the average crossreactivity for each group of samples was comparable for the two methods. The recovery of digoxin added to samples from each group of DLIF was similar, except for that from cord blood samples, for which recovery was significantly lower with the AxSYM method. Titration of a digoxin-spiked serum pool with digoxin-immune Fab showed a similar decrease in the measured digoxin concentration for both methods. Overall, the analytic performance characteristics of these two methods were comparable.     

Health service delivery to outback South Australia: a story of organizational change

Discusses attempts to meet in an accessible, equitable and high-quality way, the health needs of 35,000 South Australians in 1.68 million square kilometres. Illustrates innovative work practices, developing teams and responses to regionalization.