The purpose of this study was to examine the relation among the angiographic severity of coronary artery lesions, coronary flow velocity and translesional pressure gradients.
Determination of the ...clinical and hemodynamic significance of coronary artery stenoses is often difficult and inexact. Angiography has been shown to be an imperfect tool for determining the physiologic significance of eccentric or irregular coronary lumen narrowing.
Using a 0.018-in. (0.046 cm) intracoronary Doppler-tipped angioplasty guide wire, spectral flow velocity data both proximal and distal to coronary stenoses were compared with translesional pressure gradient measurements and angiographic data obtained during cardiac catheterization in 101 patients. There were 17 patients with normal angiographic findings and 84 with coronary artery disease, with lesions ranging from 28% to 99% diameter narrowing. Patients with coronary disease were assigned to two groups on the basis of translesional gradients at rest. Group A (n = 56) had gradients < 20 mm Hg, and Group B (n = 28) had gradients > or = 20 mm Hg.
Proximal average peak velocity, diastolic velocity integral and total velocity integral were slightly but statistically lower in Group A; however, the distal average peak velocity and diastolic and total velocity integrals were all markedly (all p < 0.01) decreased in patients with gradients > or = 20 mm Hg (Group B). In addition, the ratio of proximal to distal total flow velocity integral was higher in Group B (2.4 +/- 1.0) than in group A (1.1 +/- 0.3, p < 0.001). There was a strong correlation between translesional pressure gradients and the ratios of the proximal to distal total flow velocity integrals (r = 0.8, p < 0.001), with a weaker relation between quantitative angiography and pressure gradients (r = 0.6, p < 0.001). In angiographically intermediate stenoses (range 50% to 70%), angiography was a poor predictor of translesional gradients (r = 0.2, p = NS), whereas the flow velocity ratios continued to have a strong correlation (r = 0.8, p < 0.001). Only two patients with a proximal/distal total flow velocity ratio < 1.7 had a translesional gradient > 30 mm Hg. Both patients had a very proximal lesion in a nonbranching right coronary artery.
These data demonstrate that in branching human coronary arteries, a close relation exists between translesional hemodynamics and distal coronary flow velocity. Translesional coronary flow velocity is a new and easily applicable method for determining the hemodynamic significance of coronary artery stenoses that is superior to angiography and can be applied at the time of diagnostic catheterization. These data will provide a rational approach to making decisions on the use of coronary interventional techniques when angiographic findings are questionable.
The Astropy Project supports and fosters the development of open-source and openly developed Python packages that provide commonly needed functionality to the astronomical community. A key element of ...the Astropy Project is the core package astropy, which serves as the foundation for more specialized projects and packages. In this article, we provide an overview of the organization of the Astropy project and summarize key features in the core package, as of the recent major release, version 2.0. We then describe the project infrastructure designed to facilitate and support development for a broader ecosystem of interoperable packages. We conclude with a future outlook of planned new features and directions for the broader Astropy Project.
The conditions for antenna diversity action are investigated. In terms of the fields, a condition is shown to be that the incident field and the far field of the diversity antenna should obey (or ...nearly obey) an orthogonality relationship. The role of mutual coupling is central, and it is different from that in a conventional array antenna. In terms of antenna parameters, a sufficient condition for diversity action for a certain class of high gain antennas at the mobile, which approximates most practical mobile antennas, is shown to be zero (or low) mutual resistance between elements. This is not the case at the base station, where the condition is necessary only. The mutual resistance condition offers a powerful design tool, and examples of new mobile diversity antennas are discussed along with some existing designs.
Diversification of the primary antibody repertoire occurs in young rabbit appendix. As a prelude to molecular investigation of whether human appendix has a similar role, we compared the lymphoid ...morphology and distribution of common B- and T-cell subsets in frozen and/or paraffin-embedded normal appendix specimens at various ages. IgA, IgM and IgG staining patterns were similar in frozen human and rabbit appendices. The elongated follicles of the young human and rabbit appendices regressed with age to resemble Peyer’s patches. Although similar in morphology to the bursa, human and rabbit appendix follicles differ in that they do not involute completely with age and contain significant numbers of germinal center (GC) T cells although the number is low early in life. If the human appendix functions as a primary lymphoid organ, it may occur during the first few months of age when the GC T-cell density is low.
Epicardial and resistance vessel function in the transplanted heart has been evaluated primarily in regions supplied by a single vessel. Heterogeneity of flow among multiple perfusion fields as a ...marker of early endothelial dysfunction in the microcirculation has not been evaluated previously. This study tested the hypothesis that increased variability of coronary flow reserve (CFR) among multiple vascular regions would be associated with allograft coronary vasculopathy.
One hundred six posttransplant patients undergoing cardiac catheterization had measurement of CFR in at least 3 major epicardial vessels. Patients were divided into those with minimal angiographic abnormalities (n=37) and those with no angiographic abnormalities (n=69). The ranges, coefficients of variation, and univariate and multivariate regression analyses of CFR were computed to determine the major clinical factors influencing the degree of variability. The abnormal angiographic group was older (54+/-11 versus 47+/-13 years; P<0.003), had older hearts (35+/-11 versus 27+/-10 years; P<0.005), and were further posttransplant (1626+/-1022 versus 931+/-984 days; P<0.0009). There was no difference in global CFR between groups (normal, 3.4+/-0.8 versus abnormal, 3.4+/-0.7; P=NS). The coefficient of variation of CFR was higher for the abnormal group (16.3+/-8.6% versus 11.0+/-5.5%; P<0. 0006). Univariate and multivariate predictors of increased variability in CFR included angiographic abnormalities, patient age, and body mass index. Both angiographic abnormalities and an elevated CV of CFR were predictive of a combined end point of death, congestive heart failure, or subsequent development of >/=50% coronary stenosis.
These data demonstrate that increased variability of CFR is associated with discernible allograft coronary arteriopathy and is predictive of outcome in patients after heart transplantation.
The purpose of this study was to evaluate the relationship between increasing hospital volume and the following outcomes for total shoulder arthroplasties done in the state of New York: length of ...stay, hospital costs, readmission within 60 days, revision surgery within 24 months, and death within 60 days. The Statewide Planning and Research Cooperative System (SPARCS) database from the New York State Department of Health, a census of all hospital discharges in the state, was used to evaluate the relationship between hospital volume and outcomes for total shoulder arthroplasties for 1996 to 1999. One thousand three hundred seven total shoulder arthroplasties were done in New York from 1996 to 1999. Nearly (1/2) were done at the five highest-volume hospitals. Middle-volume hospitals has the least lengths of stay and hospital costs. Independent of age and comorbidities, patients at hospitals with greater volumes of total shoulder arthroplasties were at reduced risk of patients being readmitted within 60 days. No other outcomes were significantly associated with hospital volume. The finding that greater hospital volume decreases risk of readmission may have important public health implications, but additional research is needed before implementing policy changes.
Drawing on the changing landscape of responses to HIV in Vietnam, this article describes the key players and analyzes the relationships between global players and local interests, including both the ...omnipresent state and an emerging civil society presence. We discuss the critical importance of timing for policy intervention and the role of health policy in shaping the broader social terrain. The interventions of external actors such as the US President's Emergency Plan for AIDS Relief (PEPFAR) and the Global Fund were instrumental in improving both policies and programs at a critical juncture, when the national responses to the epidemic had been ineffective. At the same time, those global interventions met resistance and led to unintended consequences, both welcome and unwelcome. Furthermore, the looming specter of donor withdrawal and the very gradually emerging national ownership raise many questions about capacity for scale-up and sustainability of the significant achievements to date. Further monitoring and in-depth analysis of the Vietnamese responses to the HIV epidemic in the next few years or so, we contend, have the potential to provide unique insights into the challenges faced by developing countries caught in the complex webs of health politics and policies at both the global and the national levels.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, ODKLJ, OILJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK, VSZLJ
Background —Low-dose alteplase with standard-dose abciximab enhances reperfusion 90 minutes after acute myocardial infarction (MI). We combined standard-dose abciximab with low-dose reteplase for ...acute MI in 2 phases. Two heparin doses were also explored. Methods and Results —Phase A patients were randomized 4:1 to receive an abciximab bolus with infusion alone (n=63) or with 5 U, 7.5 U, 10 U, 5 U+2.5 U, or 5 U+5 U of reteplase (total n=241). Phase B tested the best phase A strategy (abciximab plus 5 U+5 U reteplase, expressed as abciximab-reteplase 5+5 U; n=115) against 10 U+10 U reteplase alone (n=109). The primary end point was Thrombolysis In Myocardial Infarction (TIMI) grade 3 flow at 60 to 90 minutes. In phase A, 62% of the abciximab-reteplase 5+5 U group had TIMI grade 3 flow versus 27% of the abciximab-only patients ( P =0.001). In phase B, 54% of the abciximab-reteplase 5+5 U group had grade 3 flow versus 47% of the reteplase-only patients ( P =0.32). Grade 3 flow rates were 61% for a 60 U/kg heparin bolus and abciximab-reteplase 5+5 U, 51% for a 40 U/kg heparin bolus and abciximab-reteplase 5+5 U ( P =0.22), and 47% for reteplase alone ( P =0.05 versus the 60 U/kg heparin group). Major bleeding rates in phase A were 3.3% for abciximab alone and 5.3% for abciximab-reteplase 5+5 U; rates in phase B were 9.8% for abciximab-reteplase 5+5 U and 3.7% for reteplase alone. Major bleeding was similar with standard- or low-dose heparin (6.3% versus 10.5%, P =0.30). Conclusions —In this phase II trial, adding reteplase to abciximab treatment of acute MI versus reteplase alone enhanced the incidence of early complete reperfusion after the initiation of therapy in the emergency department.
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