Accuracy of single-photon emission computed tomography myocardial perfusion imaging in patients with stents in native coronary arteries

Strategies to noninvasively evaluate patients after coronary stenting have not been evaluated. To determine the accuracy of single-photon emission computed tomography (SPECT) myocardial perfusion imaging in patients after coronary stenting, 209 patients who had undergone stenting followed by late stress SPECT myocardial perfusion imaging were evaluated. Quantitative coronary angiography was performed in 33 patients following SPECT imaging. SPECT restenosis was defined as a reversible or fixed defect within the stented vascular territory. Angiographic restenosis was examined using 2 definitions: total area narrowing > or =50% or > or =70% of the stent site or stented artery. The SPECT and angiographic findings were concordant in 22 of 33 stented vascular territories using the 50% definition of restenosis and in 29 of 33 stented territories using the 70% definition. Use of the 70% definition of restenosis resulted in improved accuracy of SPECT to detect a significant stenosis in the stented artery. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of SPECT were 95%, 73%, 88%, 89%, and 88% respectively. In patients with positive SPECT scans, the most significant stenosis in the stented artery was outside the stent site in 50% of cases. SPECT imaging appears to be accurate to predict significant stenosis in the stented artery, although the most severe stenosis is frequently distant from the stent site.     

Characterisation of L-[3H]glutamate binding to fresh and frozen crude plasma membranes isolated from cerebral cortex of adult rats

Specific [3H]glutamate binding to fresh crude plasma membranes (CPMs) was compared with binding to frozen CPMs and the optimal conditions for the binding to frozen CPMs isolated from cerebral cortex of adult rats were determined. Freezing reduced [3H]glutamate binding (3.5-fold), and pre-incubation of previously frozen membranes followed by three washes increased binding (4.5-fold) when compared to fresh samples. CPMs washed once, pre-incubated at 37 degrees C and washed 3 times was adopted as the most adequate condition for the binding assay of frozen membranes. In a Cl(-)-containing medium, [3H]glutamate binding (Bmax=97.9 pmol/mg, Kd=349.68 nM) to this frozen CPM preparation was significantly displaced by excess quisqualic acid (QA) (65%), L-2-amino-4-phosphonobutyric acid (L-AP4) (35%), trans-1-aminocyclopentane-1,3-dicarboxylate (1S,3R-ACPD) (25%) and alfa-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) (25%). In a Cl(-)-free medium, binding (Bmax=44.14 pmol/mg, 311 nM) was significantly displaced by QA (45%), L-AP4 (25%), ACPD (25%), AMPA (25%), kainic acid (20%) and N-methyl-D-aspartate (15%).     

Database of mutations in the p53 and APC tumor suppressor genes designed to facilitate molecular epidemiological analyses

Germline and somatic mutations in the p53 and APC genes contribute to neoplasia. The patterns of these and other acquired mutations in cancers reflect environmental mutagens and endogenous factors that contribute to carcinogenesis. Herein, we describe a database of almost 2,300 mutations in the p53 and APC genes published until September 1, 1993. In addition to cataloging the mutations, multiple fields of information have been added to facilitate future molecular epidemiological analyses of human cancer. The accuracy of the database has been checked by the present authors and, by soliciting feedback from the original corresponding authors. The strengths and limitations of the primary literature are discussed.     

Pneumatic dilatation is effective long-term treatment for achalasia

Although pneumatic dilatation (PD) has been an established treatment for achalasia for decades, there is limited information on its long-term clinical efficacy. We have followed up the clinical status of patients having PD with a 30- or 35-mm balloon by one of us (D.O.C.) over a 25-year period. Of 144 patients whose initial records were available for review, 31 could not be contacted. Of the remaining 113 patients, 72 (64%) responded to a questionnaire assessing swallowing status and patient satisfaction, and this forms the basis of this report. There were 32 men and 40 women, with mean age 46 years (range: 17-78); mean length of follow-up since PD was 6.5 years (range: 10 months to 25 years). Success was primarily defined by the need for no additional therapy for achalasia other than one or two PD's. PD was effective long-term treatment in 61/72 patients (85%); only four of these required a second PD over this time interval. There was no significant difference in any of the following parameters between patients with a treatment success or failure: age, sex, size of pneumatic dilator, and duration of symptoms prior to PD. Response was significantly better (P < 0.05) in patients having no prior dilatation (43/47; 91%) than in those in whom another physician had performed prior dilatation (18/25; 72%). In response to the question of whether they would select PD again, 68 patients (94%) responded positively. In conclusion, pneumatic dilatation performed using a consistent technique by an experienced physician is effective long-term therapy for achalasia patients of all ages. Most patients require only one dilatation.     

A review of new oncotropic tracers for PET imaging

We have developed three biochemical probes to determine if they are sensitive probes of early biochemical change in a tumor. All three probes appear to have the appropriate properties for in vivo imaging, but must now be evaluated as probes for the sensitive detection of changes in early malignant disease.     

Involvement of polyamines in the protection of taurine against the cytotoxicity of hydrazine or carbon tetrachloride in isolated rat hepatocytes

Taurine (2-aminoethanesulfonic acid) is known to protect hepatocyte injury induced by hydrazine or carbon tetrachloride. We investigated whether cellular polyamines are involved in the protective mechanism of taurine in the hepatocyte injury caused by hydrazine or carbon tetrachloride. The agents decreased cellular polyamine concentrations, but the treatment with taurine prevented this decrease. The protection of taurine against hepatic injury was not observed in hepatocytes treated with alpha-difluoromethylornithine (DFMO), an irreversible inhibitor of ornithine decarboxylase which is a key enzyme in polyamine biosynthesis. The protection of taurine was recovered by the addition of polyamines to DFMO-treated hepatocytes. These results suggest that cellular polyamines play an important role in the protection of taurine in hydrazine or carbon tetrachloride-induced hepatocyte injury.     

Cataract extraction rates in Olmsted County, Minnesota, 1980 through 1994

Management of Q-wave acute myocardial infarction (AMI) has been shown to differ between the United States and Canada, with more catheterization and revascularization procedures performed in the United States, but with little or no apparent difference in clinical outcomes. No previous studies have evaluated management differences for the acute coronary syndromes of unstable angina pectoris and non-Q-wave AMI. We therefore compared treatments and outcomes between 14 United States and 4 Canadian tertiary care centers participating in an observational registry of all consecutive admissions for unstable angina or non-Q-wave AMI between 1990 and 1993. A random, stratified sample was selected for detailed assessment and follow-up. There were 1,733 patients enrolled in United States centers and 642 in Canadian ones. In United States centers patients were less likely to receive intravenous nitroglycerin, heparin, beta blockers, calcium antagonists, or > or = 2 anti-ischemic agents. Coronary arteriography during index hospitalization was equally frequent in both countries (63.4% vs 66.9%, p = 0.781), but at 6 weeks and 1 year coronary arteriography was slightly less frequent in the United States patients. Revascularization by coronary angioplasty or bypass surgery was equivalent at 6 weeks and 1 year; however, there were trends toward less angioplasty and more bypass surgery in the United States than in Canada. Patients at United States centers stayed in the hospital fewer days than patients at Canadian centers (mean 8.2 vs 12.1 days, p <0.001). Death or AMI by 6 weeks was not different (4.8% vs 4.4%, p = 0.633), nor was it different at 1 year (10.0% vs 10.2%, p = 0.836). The combined outcome of death, AMI, or recurrent ischemia was more common in United States than in Canadian patients at 6 weeks (18.4% vs 13.9%, p = 0.004). Our findings indicate that United States physicians and hospitals did not consistently utilize more resources and were not more aggressive than their Canadian counterparts when treating acute coronary syndromes during this period.     

Problems associated with rabies preexposure prophylaxis

With the rabies vaccine presently available for preexposure prophylaxis, 20% of all individuals do not have seroconversion following routine immunizations, and 5% are allergic to this vaccine. Two experimental rabies vaccines of cell culture origin offering greater purity and potency were evaluated by means of a double-blind experiment. Thirty-one volunteers who did not have seroconversion or who were allergic to duck embryo rabies vaccine received rabies vaccine produced in either human diploid cell culture (WI-38), or hamster kidney-cell culture. All volunteers had seroconversion within 14 days of receiving a single injection of other experimental vaccine. Clinical side effects were only minor.     

Pinning of Austenite Grain Boundaries by

The growth behavior of austenite grains in the presence of A1N precipitates varies with the temperature and time of anneal. To study this behavior, two iron alloys, (in weight percent) a 0.1 carbon base chemistry with 0.03A1/0.01N and 0.09A1/0.04N, respectively, were annealed between 1000 °C and 1200 °C for times of up to 180 minutes. Using optical microscopy, as many as 1000 austenite grains per heat-treatment condition were measured. Conditions of sup- pressed, abnormal, and uniform grain growth were observed. Using an extraction replica tech- nique, the size, shape, and distribution of the A1N particles were determined using transmission electron microscopy (TEM). The largest grain boundary curvatures calculated, using the Hellman- Hillert pinning model, were in close agreement with independent calculations of curvatures using the grain size data. The largest grains in the lognormal size distribution of austenite grains were found to be the ones with the potential to grow to abnormally large sizes.     

Zinc-and aluminum-based protective coatings obtained in a fluidized bed

Sherardizing and zinc-aluminizing Ct3 steel in a fluidized bed are considered. Microhardness, microbrittleness, porosity, and corrosion resistance of zinc coatings are analyzed. Original Russian Text ? Yu.A. Balandin, A.S. Kolpakov, E.V. Zharkov, 2006, published in Zashchita Metallov, 2006, Vol. 42, No. 4, pp. 379–382.