A simplified method for the preparation of indium-DTPA brain scanning agent.
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Brain↗
Biomedical subjects
T Hill
Publications and source records attributed to T Hill.
MR perfusion imaging of the kidney pre- and post-dipyridamole stress.
Animal studies have demonstrated that renal MR contrast enhancement depends on the timing of image acquisition. Limited human studies have demonstrated effects of dipyridamole (DP) on total renal perfusion. This study assessed the effect of DP on total and regional renal perfusion using gated perfusion MRI for patients undergoing DP stress. Five subjects with no evidence of renal ischemia were examined at rest and after DP stress. Rest MRI images in the left kidney were acquired using electrocardiogram (ECG)-gated MR: turbo fast low-angle shot (FLASH); echo time (TE) = 12, repetition time (TR) = 6, flip angle = 12, inversion time (TI) = 100) 10 to 45 seconds after injection of gadopentetate dimeglumine. Stress was induced in the MRI scanner (DP, .56 mg/kg over 4 minutes) followed by stress MRI after a second bolus of gadopentetate dimeglumine in the same position and identical time intervals. MR signal in the whole left kidney and renal medulla and cortex pre- and post-DP demonstrated a 70% depression of total renal perfusion with relative preservation of cortical perfusion at the expense of medullary perfusion. Post-DP MR images demonstrated a decrease in cortical perfusion with an additional 29% depression of medullary perfusion (P < .001) with respect to cortical perfusion. Turbo FLASH MRI can provide adequate time and spatial resolution to demonstrate changes in renal perfusion. Depression of renal medullary perfusion after DP appears to be caused by the intrarenal effect of DP and may have clinical impact.
Aged↗
Case report: legionella infected thoracic aortic graft.
A case of a thoracic aortic graft in a patient with Marfan's syndrome infected with legionella is presented. The pathogenesis of graft infection and aspects of examination with aortography, gallium scanning, magnetic resonance imaging (MRI), and spiral volumetric computed tomography (CT) are presented, and the pathophysiology and management of thoracic aortic graft infections is briefly discussed.
Aortic Dissection↗
Variability in breathing patterns during latent labor. A pilot study.
This study examined the breathing patterns of a small sample of women (n = 21) during latent labor. The study also examined the different thoughts or cognitions the women experienced during their early contractions and assessed whether these cognitions, when classified as associative or dissociative in orientation, were related to breathing styles and length of labor. Respiration rate and tidal volume were monitored during and between contractions using a noninvasive plethysmograph system. The breathing results indicated considerable variation among women in individual respiration rate and tidal volume both between and during contractions. In addition, marked variability was found in both the direction and degree of change in breathing frequency and tidal volume in response to contractions. Women who relied predominantly on associative strategies during early labor had lower breathing rates and higher tidal volumes than did women who employed dissociative strategies.
Adult↗
Hydroquinone: genotoxicity and prevention of genotoxicity following ingestion.
Plant-derived polyphenolics and other chemicals with antioxidant properties have been reported to inhibit the expression of genotoxic activity by pro-oxidant chemicals (Sai et al., 1992, 1994; Teel and Castonguay, 1992). In vitro and in vivo studies with ionizing radiation suggest that hydroquinone (HQ) may have similar protective effects (Babaev et al., 1994). The present study was conducted to determine whether HQ is capable of inhibiting the induction of micronuclei in the bone marrow of mice following exposure to an oxidant, potassium bromate or KBrO3 (Nakajima et al., 1989; Sai et al., 1992, 1994). To be able to interpret the results of this work, it was also necessary to determine whether HQ is itself genotoxic when fed in the diet. HQ diets (0.8%) fed to mice for 6 days reduced the background incidence of micronuclei compared with the basal diet. KBrO3 dosed ip (12.5-100 mg/kg) produced a dose-dependent increase in micronuclei as reported by others. Mice fed 0.8% HQ diets 6 days, and then dosed intraperitoneally with KBrO3, showed a 36% reduction in micronuclei across the range of KBrO3 dose levels. This effect was associated with a reduction in the background micronucleus response as well as a reduction in response to KBrO3. Statistical significance (P < or = 0.05), observed at a dose of 25 mg/kg KBrO3 in the mice fed the control diet, was abolished in the group fed 0.8% HQ. When mice were given 50 mg HQ/kg by oral gavage and then given 50 mg KBrO3/kg ip 20 min later, the micronucleus response induced by KBrO3, was lower in animals given HQ. The results of this study demonstrate that large doses of HQ may be given orally without induction of micronuclei or bone marrow depression, that HQ reduces the background micronucleus response in animals fed a basal diet, and that the HQ reduces the micronucleus response to KBrO3 as well as background incidence of micronuclei in KBrO3-dosed animals. The protective effect of HQ may be due to enzyme induction or a direct antioxidant effect of HQ against oxidants commonly present in the diet.
Administration, Oral↗
Decreased platelet adherence of polymer-coated tantalum stents.
PURPOSE: To compare the acute thrombogenicity of polyurethane-coated stents with that of bare tantalum stents. MATERIALS AND METHODS: Thirty stents (15 coated with polyurethane) were balloon expanded in 8-mm x 80-cm sections of polytetrafluoroethylene grafts (six stents per graft). Under sterile conditions, 8- and 10-F vascular sheaths were placed percutaneously in the femoral artery and vein of a 100-lb (45-kg) swine. Platelets were labeled with indium-111 and reinjected for quantitative assay. The stented grafts were connected to the arterial and venous sheaths to create an ex vivo fistula. Each fistula was opened for 5, 10, 30, 60, or 120 minutes, exposing heparinized blood to fully expanded stents. The fistulas were closed, flushed with saline until clear, and fixed with formalin. Stents were explanted, placed in a radionuclide well counter, and scanned with electron microscopy. RESULTS: Quantitatively, there were considerably fewer platelets on coated versus uncoated stents. At 60 minutes, coated stents averaged 12.93 platelets per 1,000 microns 2 compared with 75.88 platelets per 1,000 microns 2 for bare metallic stents. At 120 minutes, there were 23.22 platelets/1,000 microns 2 versus 102.31 platelets/1,000 microns 2, respectively. Electron microscopy of coated stents demonstrated few scattered platelets at 5, 10, and 30 minutes. There was a uniform layer of platelets at 60 and 120 minutes. Uncoated stents demonstrated random areas of platelet clumping at 5, 10, and 30 minutes. At 60 and 120 minutes, uncoated stents showed extensive layering of platelets and fibrin. CONCLUSION: Polyurethane coating decreases platelet adhesion, relative to bare tantalum, at all time intervals tested.
Animals↗
[The Mecron-titanium prosthesis].
To answer the question of the duration of cementless hip-endoprostheses 59 Mecron-Titanium-prosthesis were compared with a contingent of 56 prostheses with a Chromium-Cobalt-Molybdenum-stem. The clinical as well as the radiological results are compared in a 2-5 years follow up. It is shown, that the Titanium stem reaches 93.2% "very good" to "satisfactory" results in the Merl d'Aubigné-Scheme the Chromium-Cobalt-Molybdenum-stem in comparison only in 85.71%. The x-ray pictures show, that the Titanium stems cause less sclerosis of the femur than the Chromium-Cobalt-Molybdenum-stems. The radiologic signs of loosening of both stems nevertheless do not correlate with the subjective and clinical results. It has to be mentioned that it was not possible to carry out a complete following up of all patients on the fact that some did non appear to the follow-up-examination.
Chromium Alloys↗
The use of library and information resources in three rural AHECs.
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Grateful Med↗