Usefulness of technetium-99m sestamibi infarct size in predicting posthospital mortality following acute myocardial infarction.

In this multicenter study, 249 patients who underwent tomographic technetium-99m sestamibi infarct size measurement at hospital discharge were followed up for a median duration of 7 months. Infarct size was significantly associated with mortality (chi-square = 5.8, p = 0.02) and could stratify patients into lower and higher risk subsets: 1-year mortality 2% for infarct size < 14% versus 8% for infarct size > or = 14% of the left ventricle.

Evaluation of two oral baiting systems for wild rodents.

Tetracycline hydrochloride (TC)-treated peanut butter or rodent chow baits were distributed during March 1990, on separate 0.53 ha sites in Oglethorpe County, Georgia (USA). Rodents were trapped on a control site prior to bait distribution and on two baited sites 6 days post-distribution. Cleaned skulls from euthanized mammals were grossly examined for TC fluorescence using an ultraviolet (UV) light. Mandibles were sectioned and examined for TC fluorescence using an ultraviolet light microscope. All 21 cotton rats (Sigmodon hispidus), four eastern harvest mice (Rithrodontomys humulis), and two golden mice (Ochrotomys nuttalli) captured on the control site were negative for TC fluorescence. On the peanut butter bait site, mandible sections from 29 of 32 (91%) cotton rats, three of three (100%) eastern harvest mice, two of three (66%) golden mice, zero of five (0%) white-footed mice (Peromyscus leucopus), one of three (33%) short-tailed shrews (Blarina brevicauda), and zero of two (0%) least shrews (Cryptotis parva) were positive for TC. Results from the rodent chow bait site indicated that 18 of 25 (72%) cotton rats, zero of three (0%) eastern harvest mice, two of seven (29%) golden mice, zero of four (0%) white-footed mice, and zero of four (0%) least shrews were positive for TC fluorescence in mandible sections. These results suggest that a large portion of a free-ranging small rodent population can be administered biological markers or vaccines using baits.

Poloxamer-188 as an adjunct to primary percutaneous transluminal coronary angioplasty for acute myocardial infarction.

Poloxamer-188 is a surfactant polymer with antithrombotic and hemorheologic properties that make it potentially useful as an adjunct to acute reperfusion strategies. Animal studies and early human studies have documented poloxamer-188 to be effective at improving myocardial salvage when used as an adjunct to intravenous thrombolytic therapy for acute myocardial infarction. The current trial was a prospective pilot study involving 150 patients who were randomized in a 2:1 fashion to a poloxamer-188 infusion for 48-hours versus placebo. The poloxamer-188 infusion was well tolerated subjectively. The only clinically significant laboratory abnormality noted was an elevation in the serum creatinine above 2.0 g/dl in 12% (n = 12) of the 98 poloxamer-188 treated patients versus 1 of the 52 (2%) of the placebo treated patients (p = 0.048). Clinical end points including reinfarction (1% vs 4%), cardiogenic shock (7% vs 6%), and death (9% vs 4%) were statistically similar in the poloxamer-188 and placebo groups, respectively (p = NS). Using quantitative nuclear techniques, final infarct size and myocardial salvage were statistically similar in the poloxamer-188 and placebo groups. Mean left ventricular ejection fractions 1 week post after infarction were 51% +/- 12% in the poloxamer-188 group and 52% +/- 13% in the placebo group (p = NS). Final infarct size, was not altered by the poloxamer- 188 infusion; however, it was significantly correlated with normal perfusion (Thrombolysis in Myocardial Infarction grade 3 flow) in the infarct vessel after angioplasty. This study documented poloxamer-188 to be ineffective as an adjunct to primary angioplasty for acute myocardial infarction and resulted in azotemia in 12% of the patients.

Beneficial effects of RheothRx injection in patients receiving thrombolytic therapy for acute myocardial infarction. Results of a randomized, double-blind, placebo-controlled trial.

BACKGROUND: RheothRx (poloxamer 188) is a surfactant with hemorheological and antithrombotic properties that reduces myocardial reperfusion injury in animal models of myocardial infarction. The purpose of the present study was to evaluate the safety and efficacy of adjunctive therapy with poloxamer 188 in patients receiving thrombolytic therapy for acute myocardial infarction. METHODS AND RESULTS: In this multicenter trial, we randomized 114 patients to a 48-hour infusion of poloxamer 188 or vehicle placebo beginning immediately after the initiation of thrombolytic therapy. Tomographic imaging with 99mTc sestamibi before reperfusion and again 5 to 7 days after the infarction was used to determine myocardium at risk for infarction, infarct size, and myocardial salvage. Radionuclide angiography at 5 to 7 days after infarction was used to measure left ventricular ejection fraction. The treated and control groups had comparable baseline characteristics, time to thrombolytic administration, and time to treatment with poloxamer 188 or placebo. Poloxamer 188-treated patients demonstrated a 38% reduction in median myocardial infarct size (25th and 75th percentile) compared with placebo (16% [7, 30] versus 26% [9, 43]; P = .031), greater median myocardial salvage (13% [7, 20] versus 4% [1, 15]; P = .033), and a 13% relative improvement in median ejection fraction (52% [43, 60] versus 46% [35, 60]; P = .020). Poloxamer 188 treatment also resulted in a reduced incidence of reinfarction (1% versus 13%; P = .016). Poloxamer 188 was well tolerated without adverse hemodynamic effects or significant organ toxicity. CONCLUSIONS: Adjunctive therapy with poloxamer 188 resulted in substantial benefit in this randomized trial, including significantly smaller infarcts, greater myocardial salvage, better left ventricular function, and a lower incidence of in-hospital reinfarction. Although the mechanisms are unproven, poloxamer 188 treatment may accelerate thrombolysis, reduce reocclusion, and ameliorate reperfusion injury.

The relationship of inferior ST depression, lateral ST elevation, and left precordial ST elevation to myocardium at risk in acute anterior myocardial infarction.

The purpose of this study was to examine the relationship between the presence or absence of ST segment depression in inferior leads (II, III, and aVF) and ST segment elevation in lateral (I and aVL) or left precordial (V5 and V6) leads with the amount and location of myocardium at risk for infarction in patients with acute anterior myocardial infarction. Forty-three patients with anterior infarctions were injected with technetium 99m-sestamibi when they were first seen and underwent tomographic imaging to measure the amount and location of myocardium at risk. Patients with inferior ST depression (n = 10) compared with those without ST depression (n = 33) had perfusion defects that extended significantly further into the lateral wall (47 degrees vs 20 degrees, p = 0.04) and larger anterior injury vectors (6.47 vs 4.92, p = 0.008). There was no significant association with the percentage of myocardium at risk, disease of the right coronary artery, the presence of an inferior perfusion defect, or the size of the inferior injury vector. Among the patients with ST elevation in lateral leads (n = 16) compared with those without (n = 27), there was a significantly more lateral defect border (47 degrees vs 25 degrees, p = 0.007) and a larger anterior injury vector (6.07 vs 4.81, p = 0.01). There was no significant correlation with the percentage of myocardium at risk. A significant relationship could not be demonstrated between the presence of ST elevation in the left precordial leads and any measure of the amount or location of myocardium at risk. These data support the theory that inferior ST depression in patients with transmural anterior ischemia is a "reciprocal" finding and does not represent inferior ischemia. The presence of inferior ST depression or lateral ST elevation is associated with a more lateral perfusion defect. Neither of these ECG findings is associated with the amount of myocardium at risk for infarction.

Antibodies to vesicular stomatitis New Jersey type virus in white-tailed deer on Ossabaw Island, Georgia, 1985 to 1989.

From 1985 to 1989, 491 serum samples were collected from white-tailed deer (Odocoileus virginianus) on Ossabaw Island, Georgia (USA) and were tested for neutralizing antibodies to New Jersey and Indiana type vesicular stomatitis viruses. Prevalence of antibodies to vesicular stomatitis New Jersey (VSNJ) virus in deer for the 5-yr period was 43%. Prevalence of antibodies differed by year (P less than 0.0001), and was dependent on age class (P less than 0.0001) and location on the island (P less than 0.0001). Of 173 deer sampled from other locations in the southeastern United States, only two had VSNJ antibody titers normally considered positive (greater than or equal to 1: 32). The positive deer were from Union County, Arkansas (USA) and Wakulla County, Florida (USA). No evidence of exposure to vesicular stomatitis Indiana Virus was observed.

A field trial to determine the feasibility of delivering oral vaccines to wild swine.

A field study was conducted on Ossabaw Island, Georgia (USA) to determine the feasibility of delivering oral vaccines to wild swine (Sus scrofa). Baits were made of polymerbound fish meal and contained a gelatin capsule as a potential vaccine chamber. Two biomarkers, iophenoxic acid and tetracycline, were incorporated into each bait, and soured chicken mash was used as an attractant. Baits (n = 1,980) were distributed in a grid pattern on a 405-ha test site and monitored for animal disturbance. Within 72 hr, 88% of 393 monitored baits were gone, and observations of track-beds surrounding 100 baits indicated that at least 52% were taken by wild swine. Subsequent testing of 80 wild swine for the biomarkers revealed that 95% of the animals had consumed bait. Track-bed observations indicated that raccoons (Procyon lotor) were the only non-target animal that frequently took baits. Biomarker analyses indicated 44% of 16 raccoons tested had eaten bait. It was concluded that oral vaccine delivery to wild swine should be considered as a feasible method of control or eradication of pseudorabies and/or swine brucellosis in wild swine if effective vaccines become available.

Antibodies to vesicular stomatitis New Jersey type virus in wild and domestic sentinel swine.

Wild sentinel swine on Ossabaw Island, Chatham County, Georgia, were serially bled and tested for vesicular stomatitis New Jersey type virus neutralizing antibody to determine the intensity, distribution, and progression of annual viral activity. From March through September, 1984 and 1985, 112 and 226 juvenile (less than 8 months) swine, respectively, were sampled. Seroconversions initially were detected on May 7, 1984 and May 18, 1985. Incidence of seroconversion in wild swine reached 32% during 1984 and 26% during 1985. Viral activity as determined by seroconversion results occurred earliest and was greatest on the southern half of Ossabaw Island. Domestic swine were housed in four pens under controlled conditions to document arthropod transmission of vesicular stomatitis virus. Twelve swine, three in each pen, were serially bled from April through September of both years. Seroconversion occurred during May 16-23, 1984 and May 15-22, 1985. Results varied among pen locations but were consistent between years. Clinical disease was not seen in any wild or domestic swine during either year.

Enzootic vesicular stomatitis New Jersey type in an insular feral swine population.

Free-ranging feral swine from Ossabaw Island, Chatham County, Georgia, were serially bled and tested for vesicular stomatitis New Jersey type serum neutralizing antibody to determine the intensity and progression of annual vesicular stomatitis activity. From November 21, 1981 to October 11, 1982, and from March 15, 1983 to October 14, 1983, 307 and 340 swine were sampled, respectively. Seroconversions were initially detected during the first week of June and continued into September in both 1982 and 1983. Serologic results indicate a seroconversion incidence during 1982 and 1983 of approximately 12% and 60%, respectively. Similar patterns in timing and affected geographic area were observed during both years, with the earliest viral activity and highest incidence restricted to the southern portion of the island. Clinical vesicular stomatitis was not seen during 1982. However, during 1983, vesicular stomatitis New Jersey type virus was isolated from vesicular lesions on two swine.

Serologic surveillance for vesicular stomatitis virus on Ossabaw Island, Georgia.

Seventeen species of mammals and seven species of birds from Ossabaw Island, Georgia, were tested for vesicular stomatitis (VS) neutralizing antibodies. Seropositive results were restricted to mammals with six of 17 species testing seropositive for VS (New Jersey type) neutralizing antibodies. Seropositive species included: raccoons (Procyon lotor), white-tailed deer (Odocoileus virginianus), feral swine (Sus scrofa), cattle (Bos taurus), horses (Equus caballus), and donkeys (Equus asinus). All tests for VS (Indiana type) were negative.

Laboratory infection of house sparrows (Passer domesticus) with Mycoplasma gallisepticum and Mycoplasma synoviae.

House sparrows were infected by aerosol with Mycoplasma gallisepticum (MG) or M. synoviae (MS). MG was reisolated from 5 to 11 sparrows 10 days postinfection, but infection appeared to be temporary. Mycoplasma-free chickens reared in the experimental house became infected with MG during the trial. MS was recovered from only one sparrow. Serological tests were unsatisfactory for diagnosing infected birds. The results suggest that house sparrows may be temporary biological carriers of MG.