Association of polymorphonuclear leukocytes with sites of aortic catheter-induced injury in rabbits

The kinetics of the association of polymorphonuclear leukocytes (PMNs) with arterial balloon catheter-induced injury have been examined. An average of 6 X 10(7) PMNs were isolated from 20 ml of blood and labelled with 111In-oxine for reinfusion into the donor rabbit. The cells remained viable as demonstrated by both in vitro and in vivo tests of cell function. The abdominal aorta of rabbits was denuded of endothelium and immediately, 24 h, or 5 weeks later, exposed to autologous radiolabelled PMNs for 1 h. The presence of PMNs at sites of denudation was demonstrated by detection of the radioactive label and was confirmed by light and electron microscopy after 24 h, but not at 5 weeks. Immediately following denudation radioactivity was 2.44 +/- 0.33 times control (P = 0.006); 2.52 +/- 0.18 at 24 h (P = 0.005); and 1.88 +/- 0.32 times control at 5 weeks (P = 0.045). The presence of PMNs, or their products, 5 weeks after denudation suggests a more complex role of PMNs and possibly a direct involvement in the long term changes resulting from arterial balloon catheter injury.     

Influence of rate of administration of raclopride on akathisia and prolactin response

The D₂-dopamine receptor antagonist raclopride was administered to eight healthy male subjects, who had previously experienced akathisia following antipsychotic drugs. The influence of administration rate on onset, severity and duration of akathisia and on prolactin response was studied. Raclopride 3,5 or 9 mg or placebo (P) was administered as single IV infusions during 10 min (R10 min/3 mg), 1 h (R1h/5 mg) or 4 h (R4h/9 mg) according to a randomized double-blind design. Despite a 24-fold difference in administration rate a similar peak raclopride concentration of about 350 nmol/l was obtained after all three infusions. Three of the eight subjects experienced akathisia following R10 min/3 mg and R1h/5 mg, respectively. After R4h/9 mg seven subjects experienced akathisia of longer duration but not more severe than after the short infusions. The incidence and duration of akathisia seem to be mainly related to the plasma raclopride concentrations over time, whereas the rate of administration might be more important for the severity. A maximal prolactin response was induced which was not markedly affected by the rate of administration.     

Functional and morphologic endothelial damage in rabbit external jugular veins stored in heparinized normal saline.

Previous studies have demonstrated that vein storage in normal saline leads to significant mechanical morphological, and biochemical aberrations. However, little information is available regarding the functional damage that occurs. The purpose of this study was to evaluate the effect of saline storage on venous smooth muscle and endothelial function. Segments of ten external jugular veins from male New Zealand White rabbits were placed nondistended in either modified Krebs solution at 37 degrees C (Krebs-stored, KS) or heparinized normal saline at room temperature (saline-stored, SS) for 1 h. Segments 4 mm in length were then simultaneously studied in vitro under isometric tension. There was no difference in maximum tension or sensitivity to either bradykinin or histamine. Acetylcholine-induced relaxation in KS segments was not significantly different from relaxation in a historical cohort of nonstored segments (nonstored 87.4 +/- 1.0% vs. KS 84.5 +/- 2.0%; p = NS). However, there were significant attenuations in SS segment endothelium-dependent relaxation in response to both acetylcholine (KS 84.5 +/- 2.0% vs. SS 76.4 +/- 2.7%, p less than 0.02) and adenosine diphosphate (KS 47.9 +/- 2.9% vs. SS 40.6 +/- 3.7%, p less than 0.002). Relaxant responses to sodium nitroprusside (endothelium-independent) were not significantly different in the two groups (KS 94.6 +/- 1.6% vs. SS 95.7 +/- 2.2%; p = NS). Electron microscopic evaluation of SS segments revealed endothelial cell disruption with cellular edema and loss of intact junctions.(ABSTRACT TRUNCATED AT 250 WORDS)     

Electron Microscopy and Computed Microtomography Studies of in Vivo Implanted Mini-Tl Dosimeters

The need for direct methods of measuring the absorbed dose in vivo increases for systemic radiation therapy, and in more sophisticated methodologies developed for radioimmunotherapy. One method suggested is the use of mini-thermoluminescent dosimeters (TLD). Recent reports indicate a marked loss of signal when the dosimeters are used in vivo. We investigated the exterior surface of the dosimeters with scanning electron microscopy and the interior dosimeter volume with computed microtomography. The results show that the dosimeters initially have crystals uniformly embedded in the teflon matrix, with some of them directly exposed to the environment. After incubation in gel, holes appear in the dosimeter matrix where the crystals should have been. The computed microtomographic images show that crystals remain in the interior of the matrix, producing the remaining signal. We conclude that these dosimeters should be very carefully handled, and for practical use of mini-TLDs in vivo the dosimeters should be calibrated in equivalent milieus. An alternative solution to the problem of decreased TL efficiency, would be to coat the dosimeters with a thin layer, of Teflon, or other suitable material.     

Logics and Logistics of Community Intervention Against Osteoporosis: An Evidence Basis

Under designations like small areas action research and intervention, directed ‘ground-up’ health promotion and prevention in the population form an important part of the ongoing medical systems development. There is recent evidence of the success of community intervention against cardiovascular disease. In osteoporosis, however, there is still a lack of conclusive data on both the logics and logistics of such an approach. Since 1988, a county health policy program has been formulated and implemented in Östergötland, Sweden, following the principles and guidelines of the WHO HFA 2000 declaration. Vadstena (n ? 7,600) was chosen for a local and generalizable osteoporosis prevention project mediated by the primary care organization by means of health promotion and education in the community. In the present report we emphasize that community intervention is an important new advancement of the medical systems, where the basic research questions include operational and management aspects as equally vital and measurable requisites and results as other performance and outcome variables. We found that a community intervention trial against osteoporosis is both motivated and feasible and in this report wish to provide evidence on these crucial issues of logics and logistics.     

Rate and predictability of pulp revascularization in therapeutically reimplanted permanent incisors

Abstract The aim of the present investigation was to study the frequency of pulp revascularization in therapeutically reimplanted incisors as well; is its relationship with the following factors: width of apical foramen, duration of extra-alveolar lime, storage conditions and postoperative administration of antibiotics. Out of 72 immature teeth (width of apical foramen 1.1–5.0 mm) the pulp was revascularized in 13 (18%), while in 88 mature teeth (width of apical foramen 1.0 mm or less) no revascularization occurred. Among parameters tested statistically in immature teeth, a significantly increased frequency of revascularization (p < 0.05) was only found in teeth reimplanted within 45 minutes after avulsion, when compared with teeth reimplanted after a longer extra-alveolar time, and in mandibular incisors when compared with maxillary incisors (p < 0.01). All teeth in which revascularization did not occur exhibited a periapical radiolucency and/or external inflammatory root resorption.     

Computer simulation of periacetabular osteotomy.

A simple static three-dimensional mathematical model of an adult hip in one-legged stance was used to evaluate the mechanical situation after periacetabular osteotomy. We found that the hip joint rotation center shifted as a consequence of the osteotomy. This may have considerable effects on the hip joint resultant force and therefore also on the pressure on the femoral head, which could cause the development of arthrosis.     

Thrombin activatable fibrinolysis inhibitor and hemostatic changes in patients with type I diabetes mellitus with and without microvascular complications.

We investigated thrombin activatable fibrinolysis inhibitor (TAFI) and its influence on fibrinolysis by measuring pro-TAFI activity and total TAFI antigen in 38 patients with type I diabetes mellitus (18 with and 20 without microvascular complications), as well as in 20 healthy controls. The pro-TAFI levels in the two groups of patients did not differ from those in the control group. Total TAFI antigen [i.e. pro-TAFI, TAFI and inactive carboxypeptidase U (TAFIi)] tended to decrease in both the patient groups (59.7 +/- 7.2 and 73.4 +/- 8.9% with and without microvascular complications, respectively) compared with controls (91.9 +/- 12.2%) (P = 0.12). We also assessed the overall hemostatic potential (OHP) in plasma, the clot lysis time and the overall fibrinolytic potential. The OHP was significantly higher in patients with complications compared with controls (8.9 +/- 0.9 versus 6.7 +/- 0.4; P < 0.05) and also higher in the diabetics without complications (7.8 +/- 0.6), although the latter difference did not reach statistical significance. Levels of clot lysis time and overall fibrinolytic potential were similar in the two groups of patients and the controls. The increased OHP in plasma from diabetic patients with microvascular complications indicates an imbalance of the hemostatic system towards a prothrombotic state. No signs of impaired fibrinolysis were observed in patients with diabetes. Using the OHP method for estimation of overall hemostasis, it seems that TAFI does not influence either fibrinolysis or the increased thrombotic potential observed in patients with type I diabetes mellitus.     

Registration of myocardial infarction and stroke in the Kilkenny Health Project: Methodology

A myocardial infarction and stroke register was established in January 1987 as part of the evaluation of the Kilkenny Health Project This is a community programme which aims to reduce risk factors for coronary heart disease. The register records acute myocardial infarction and stroke in residents of County Kilkenny and of the reference county. This will provide accurate estimates of the incidence of these diseases and of trends over time. Methods used comply with the protocol in use by the WHO MONICA Project. This will allow comparison of the incidence of coronary heart disease and stroke in this register with that in other MONICA locations, including that in Belfast, Northern Ireland.