Genetic differences in internal transcribed spacer 1 between Dermanyssus gallinae from wild birds and domestic chickens

We investigated the presence of the poultry red mite or the chicken mite, Dermanyssus gallinae De Geer, Acari: Dermanyssidae, in wild bird populations in four different geographical regions of Sweden. The mites identified as D. gallinae were compared genetically with D. gallinae from egg-producing poultry farms in the same regions. The small subunit (SSU) gene, the 5.8S ribosomal RNA (rRNA) gene and the two internal transcribed spacers (ITS) of the rRNA genes were used in the genetic analysis. All D. gallinae mites had identical SSU rRNA, 5.8S rRNA and ITS2 sequences independent of their origin. By contrast, we identified significant differences in the ITS1 sequences. Based on the differences in the ITS1 sequences, the mites could be divided into two genotypes, of wild and domesticated origin, with no variation within the groups. These results imply that wild bird populations are of low importance, if any, as natural reservoirs of D. gallinae in these four geographical regions of Sweden.

Emergency percutaneous coronary intervention (PCI) for the care of patients with ST-elevation myocardial infarction (STEMI)

There is general consensus that emergency percutaneous coronary intervention (PCI) is the preferred treatment for patients with ST-elevation myocardial infarction (STEMI), so long as it can be delivered in a timely fashion, by an experienced' operator and cardiac catheterization laboratory (CCL) team. STEMI is both a functional and structural issue. Although it has been recognized since the work of pioneering cardiologists and surgeons in Spokane, Washington, that approximately 88% of patients presenting within 6 hours of onset of STEMI have an occluded coronary artery, it is the pathophysiology of myocardial necrosis, and the varied consequences of necrosis that characterize STEMI. Accordingly, experience' of both primary operator and cardiac catheterization laboratory (CCL) crew, in performing an emergency PCI for STEMI, are as much a function of experience with the treatment of complex MI patients, as experience with coronary intervention. Rapidly achieving normal coronary artery flow, at both the macro and micro vascular levels, is the recognized key to aborting the otherwise progressive wavefront' of myocardial necrosis. The time urgency of decisions (Time is muscle') make emergency PCI for patients with on-going necrosis, more like emergency room (ER) care, than like most in-hospital or outpatient care. In general, most patients with acute coronary syndromes (ACS) are currently thought to have plaque rupture and/or erosion with subsequent thrombosis and embolization. Consequences of thrombo-embolism, such as slow flow' or no-reflow' are in addition to, the structural (anatomic) considerations of PCI in stable patients (such as ostial location; bifurcation involvement; heavy calcification; tortuosity of lesion or access to it; length of disease; caliber of infarct-artery; etc.). Good quality studies have provided strong support for the specific added value of glycoprotein IIb/IIIa inhibitors (especially abciximab), dual antiplatelet therapy (the addition of the thienopyridine, clopidogrel, to aspirin use), and bare-metal stents (BMS), for a broad range of STEMI patients. The added value of drug-eluting stents (DES) to bare-metal stents (BMS), primarily in terms of reducing restenosis and repeat revascularization, is supported by several randomized trials, and a number of registries, despite its being off-label' from a regulatory standpoint. The recognition of late stent thrombosis (LST) has raised additional issues, in choosing between these two options for specific STEMI patients. The added value of a number of other mechanical approaches to coronary thrombus, such as thrombus removal devices, and/or distal protection, are more controversial, and perhaps, patient specific. Whether intravascular ultrasound guidance (IVUS) for stent use should be used for the majority, or even a specific minority, of STEMI patients, is also controversial; late-stent thrombosis provides a counter-point. The advantages of developing a network approach to STEMI care, so as to optimize the number of patients receiving timely reperfusion, have been demonstrated in Prague, Denmark, and Minneapolis, among many places. The benefits of both bivalirudin (anti-thrombin drug with efficacy against clot-bound thrombin, which does not appear to stimulate platelets) and abciximab (glycoprotein IIb/IIIa inhibitor which is antibody to platelet receptors), as PCI adjuncts generally, and for STEMI patients, in particular, are supported by multiple trials. The specific choice of administering the bolus dose of either, or both, drugs via intra-coronary (IC) injection follows the precedents' of IC thrombolytics, and IC small-vessel vasodilators for no-reflow', but it has not been tested by prospective, randomized trials. Although rapid reperfusion is the first objective, one cannot ignore the other components of the oxygen delivery chain, and the importance of each of these components to on-going delivery of oxygen to all vital organs. A balance must be struck between doing those control' things which serve to stabilize other vital components of the oxygen-delivery chain, without digressing too long from the job of re-establishing brisk coronary flow. The clinical and angiographic heterogeneity of STEMI patients and the array of available therapeutic approaches make it impossible to obtain specific randomized trial direction for many of the clinical decisions in an individual emergency PCI for STEMI. There are a range of reasonable/ appropriate therapeutic choices for a given emergent PCI performed by multiple experienced and competent operators. The treatment of STEMI, and high-risk non-STEMI, patients, by means of emergent PCI, is among the most challenging and rewarding arenas in contemporary medicine.

Cost-Effectiveness of Coronary Artery Bypass Grafts Versus Percutaneous Coronary Intervention for Revascularization of High-Risk Patients

BACKGROUND

A Department of Veterans Affairs Cooperative Study randomized high-risk patients with medically refractory myocardial ischemia, a group largely excluded from previous trials, to urgent revascularization with either percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG). The present study examined the cost-effectiveness of PCI versus CABG for these high-risk patients.

METHODS AND RESULTS

Of 454 patients at 16 Department of Veterans Affairs medical centers, 445 were available for the economic analysis (218 PCI and 227 CABG patients). Total costs were assessed at 3 and 5 years from the third-party payer's perspective, and effectiveness was measured by survival. After 3 years, average total costs were 63,896 dollars for PCI versus 84,364 dollars for CABG patients, a difference of 20,468 dollars (95% confidence interval [CI] 13,918 dollars to 27,569 dollars). CIs were estimated by bootstrapping. Survival at 3 years was 0.82 for PCI versus 0.79 for CABG patients (P=0.34). Precision of the cost-effectiveness estimates were assessed by bootstrapping. PCI was less costly and more effective at 3 years in 92.6% of the bootstrap replications. After 5 years, average total costs were 81,790 dollars for PCI versus 100,522 dollars for CABG patients, a difference of 18,732 dollars (95% CI 9873 dollars to 27,831 dollars), whereas survival at 5 years was 0.75 for PCI patients versus 0.70 for CABG patients (P=0.21). At 5 years, PCI remained less costly and more effective in 89.4% of the bootstrap replications.

CONCLUSIONS

PCI was less costly and at least as effective for the urgent revascularization of medically refractory, high-risk patients over 5 years.

Biological control of sheep parasites using Duddingtonia flagrans: trials on commercial farms in Sweden

Trials were conducted on 3 commercial sheep farms in Sweden to assess the effect of administering spores of the nematode trapping fungus, Duddingtonia flagrans, together with supplementary feed to lactating ewes for the first 6 weeks from turn-out on pastures in spring. Also control groups of ewes, receiving only feed supplement, were established on all 3 farms. Groups were monitored by intensive parasitological investigation. The ewes and their lambs were moved in late June to saved pastures for summer grazing, the lambs receiving an anthelmintic treatment at this time. After approximately 6 weeks on summer pasture the lambs were weaned, treated a second time with anthelmintic, and returned to their original lambing pastures for finishing. Decisions as to when lambs were to be marketed were entirely at the discretion of the farmer co-operators. No difference in lamb performance was found between the two treatments on all three farms. This was attributed to the high levels of nutrition initially of the ewes limiting their post-partum rise in nematode faecal egg counts in spring, which in turn resulted in low levels of nematode infection on pastures throughout the autumn period. Additionally, pastures were of good quality for the lambs during the finishing period, so they grew at optimal rates as far as the farmers were concerned.

Percutaneous coronary intervention of or through saphenous vein grafts or internal mammary arteries: the impact of stents, adjunctive pharmacology, and multicomponent distal protection

We hypothesized that the use of stents and aggressive adjunctive pharmacotherapies has been associated with lower rates of complicating myocardial infarction (MI) and improved long-term outcomes compared to either previous balloon-only percutaneous coronary intervention (PCI) or atheroablative intervention for lesions of or through saphenous vein grafts (SVGs) and/or internal mammary arteries (IMAs). PCI of SVG has been complicated by relatively high rates of procedural MI and less favorable long-term outcomes than native vessel PCI, stimulating the development and application of an array of technologies. This study was based on retrospective review of stent-era (1999-2004) 5-year experience of a single center with 95 SVG procedures in 85 patients and 20 IMA procedures in 20 patients. These cases were compared with the previously published experience of one of the operators during the balloon-only period and literature review of the application of multiple technologies to SVG intervention, as well as consideration of the reoperation alternative. There was one in-hospital death each in the SVG cohort (1%) and in the IMA cohort (5%). There were SIX procedural MIs (6%), defined by total CK > normal, and 19 procedural MIs (20%) based on troponin-I > 1.0. Follow-up has been from 4 months to 5 years (average, 2.5 years), with 91% survival and one late CABG in the IMA group. SVG PCI with stents and adjunctive pharmacotherapies is associated with relatively low rates of procedural MI and favorable long-term outcomes.

Population genetics of the bovine/cattle lungworm (Dictyocaulus viviparus) based on mtDNA and AFLP marker techniques

Mitochondrial DNA (mtDNA) sequence data and amplified fragment length polymorphism (AFLP) patterns were compared for the lungworm Dictyocaulus viviparus, a nematode parasite of cattle. Eight individual D. viviparus samples from each of 8 herds in Sweden and 1 laboratory isolate were analysed, with the aim of describing the diversity and genetic structure in populations using different genetic markers on exactly the same DNA samples. There was qualitative agreement between the whole-genome AFLP data and the mtDNA sequence data, both indicating relatively strong genetic differentiation among the Swedish farms. However, the AFLP data detected much more genetic variation than did the mtDNA data, even after allowing for the different inheritance patterns of the markers, and indicated that there was much less differentiation among the populations. The mtDNA data therefore seemed to be more informative about the most recent history of the parasite populations, as the general patterns were less obscured by detailed inter-relationships among individual worms. The 4 mtDNA genes sequenced (1542 bp) showed consistent patterns, although there was more genetic variation in the protein-coding genes than in the structural RNA genes. Furthermore, there appeared to be at least 3 distinct genetic groups of D. viviparus infecting Swedish cattle, 1 of which was predominant and showed considerable differentiation between farms, but not necessarily within farms. Second, the 2 smaller genetic groups occurred on farms where the predominant group also occurred, suggesting that these farms have had multiple introductions of D. viviparus.

Percutaneous Intervention Versus Coronary Bypass Surgery for Patients Older Than 70 Years of Age With High-Risk Unstable Angina

BACKGROUND

The Angina With Extremely Serious Operative Mortality Evaluation (AWESOME) study was a multicenter Veterans Affairs randomized trial and registry that compared long-term survival of percutaneous coronary intervention with coronary artery bypass graft surgery for the treatment of patients with medically refractory myocardial ischemia and at least one additional risk factor for an adverse outcome with bypass. Both the randomized trial and the registry demonstrated comparable 3-year survival. The purpose of this study was to compare bypass and percutaneous intervention survival of AWESOME patients who were older than 70 years of age.

METHODS

Over a 5-year period (1995 to 2000), 2,431 patients with medically refractory myocardial ischemia and at least one of the following five risk factors (prior heart surgery, myocardial infarction within 7 days, left ventricular ejection fraction less than 35%, age > 70 years, intraaortic balloon pump requirement to stabilize) were identified. Of these patients, 1,278 were older than 70 years of age. Eight hundred, seventy-one patients were turned down by at least one physician, 407 were acceptable to both physician and surgeon for randomization, and 236 (60%) consented to randomization. Of the 1,042 eligible patients who were not randomized, 871 had their revascularization directed by a physician who was not involved in the study. One hundred, seventy-one patients who were acceptable for randomization by both the interventional cardiologist and the cardiac surgeon refused consent.

RESULTS

Bypass and percutaneous intervention survival were compared using Kaplan-Meier curves and log rank tests. Bypass and percutaneous intervention 36-month survival rates for patients older than 70 years of age were 76% and 75%, respectively, among the eligible patients. Survival was 71% and 78% among those patients who were randomized and 76% and 67% in the physician-directed subgroup. Of those patients who chose their revascularization techniques, the survivals were 79% and 85%, respectively. The survival differences are not large, and none of the global log rank tests of bypass compared with percutaneous intervention survival showed a statistically significant difference over 5 years.

CONCLUSIONS

Both the randomized and registry subgroups of patients who were older than 70 years of age support the trial conclusions that either bypass or percutaneous intervention effectively relieves medically refractory ischemia among high-risk unstable angina patients whose age was greater than 70 years.