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(1) In 1981 and 1982 male and female reproductive success of mainland and near- and distant-island populations of Centrosema virginianum and Opuntia stricta growing on two island and one mainland beach communities on the western coast of Florida were compared. (2) Pollen dispersal to neighbouring plants (which was used as an estimate of male reproductive success) was significantly reduced in both island populations of Centrosema relative to the mainland population. Pollen dispersal of Opuntia was significantly lower at the far island than at the near island. (3) Female reproductive success (estimated by fruit set) was significantly lower in Centrosema on the distant island than on the near island or mainland during 1981. Fruit set in Opuntia did not differ between the near and far island however, seeds per fruit were significantly lower on the far island both years. (4) Field experiments indicated significant pollinator limitation of fruit set for Centrosema growing on the far island in 1981, but not in 1982. On the far island in 1983, there was no significant difference in the number of seeds per fruit in naturally-pollinated and hand-crossed Opuntia flowers. (5) The differences between island and mainland pollinator communities and reproductive success that were found in plant communities separated by less than 10 km of water, suggest that pollinator limitation may be an important selective force on plant communities of distant, oceanic islands. [ABSTRACT FROM AUTHOR]

Can a Sports Ministry program positively impact the church's mission among its members? Previous research with commitment theory in psychology as it relates to sports and religious activity (2, 19) indicates that what benefits that church members get out of attending church activities will impact their frequency of attendance and commitment to their church. Sports activities have long been used as a tool to bring people into the church and increase fellowship and evangelism (11). To date, there has been little empirical research into the specific benefits of a sports ministry in the opinion of the church leaders who have sports activities in their church. [ABSTRACT FROM AUTHOR]

Despite the fact that door-to-balloon times have been greatly reduced, the rates of death and the incidence of heart failure in patients with ST-segment elevation myocardial infarction (MI) have plateaued. There is still an unmet need to further reduce MI size in the reperfusion era. Most adjunctive therapies to enhance myocardial salvage have failed, but some have shown promise. Currently, the only adjunctive therapy in a pivotal trial that has demonstrated reductions in infarct size is localized delivery of supersaturated oxygen (SSO 2 ) therapy. This review provides background on prior infarct size reduction efforts. The authors describe the preclinical data that shows the effectiveness of SSO 2  in reducing MI size, improving regional myocardial blood flow and cardiac function, and reducing adverse left ventricular remodeling-presumably by reducing patchy areas of residual ischemia within the reperfused risk zone. Potential mechanisms by which SSO 2 is beneficial are described, including the delivery of high levels of dissolved oxygen through plasma to ischemic, but viable, vascular and myocardial cells, thus allowing their survival and function. The authors then describe the SSO 2 clinical trials, demonstrating that in patients with anterior ST-segment elevation MI, SSO 2 therapy safely and effectively reduces infarct size, improves cardiac function, and reduces adverse left ventricular remodeling., Competing Interests: Drs Kloner and Burkhoff have been consultants for ZOLL TherOx. Dr Creech is an employee of ZOLL TherOx. Drs. Stone and O’Neill have been consultants for ZOLL TherOx; and were involved in previous clinical trials with SSO2. Dr Spears was involved with preclinical studies with SSO2., (© 2021 The Authors.)

The purpose of this study was to determine whether the use of a periarticular injection using liposomal bupivacaine could decrease pain and improve outcomes after total knee arthroplasty. Fifty consecutive patients received no periarticular injections (group A). Another 50 consecutive patients received a periarticular injection of liposomal bupivacaine (group B). There were no differences in the groups with respect to gender, age, body mass index (BMI), or comorbidities. There was a significant reduction in the amount of narcotics used in the liposomal bupivacaine group (60.97-mg oral morphine equivalent vs 89.74 mg, P  = 0.009). Patients in group B with a BMI <40 and a Charlson comorbidity index of 0-3 had decreased length of stay (2.64 vs 3.06 days, P  = .004), narcotic use over 24-48 hours (110.66 vs 182.47 mg, P  = .013), and narcotic use over 48-72 hours (49.61 vs. 112.65 mg, P  = .004). In patients with a BMI <40 and comorbidity index of ≤3, periarticular injection using liposomal bupivacaine leads to earlier discharge along with decreased use of narcotics.

Unlabelled: Transient ischemic dilation (TID) in the setting of abnormal stress-rest cardiac SPECT myocardial perfusion imaging (MPI) has been linked with increased cardiovascular risk. However, the significance of TID in the setting of an otherwise normal SPECT MPI study has not been clearly established. In this study, cardiac CT was used to evaluate the prevalence of atherosclerotic lesions and the severity of coronary artery stenosis in patients with TID of the left ventricle with or without associated myocardial perfusion defects on SPECT MPI., Methods: The study population consisted of 1,553 consecutive patients who had undergone both cardiac CT and SPECT MPI within 1 mo between January 1, 2006, and September 1, 2011. Patients included in the study group had a pathologic TID value defined as ≥1.18 for men and ≥1.22 for women. Coronary CT angiography was used to evaluate each coronary segment for the presence and composition of atherosclerotic plaque and the degree of coronary stenosis. TID-positive patients were compared with a 2:1 risk-factor-matched-pair control cohort without TID., Results: TID was identified in 30 patients who were compared with TID-negative risk-factor-matched controls (n = 60). When compared with the TID-negative control cohort, TID-positive patients had no significant differences in the presence and extent of atherosclerosis, the degree of coronary artery stenosis, or the calcium score at cardiac CT. Similarly, there were no significant differences in these CT measures in TID-positive patients with a normal perfusion study (n = 20) when compared with TID-negative patients with a normal perfusion study (n = 48). In addition, there was no significant difference in the incidence of major adverse cardiac events when comparing both the TID-positive patients and the TID-negative control cohort and when comparing patients who were TID-positive with normal perfusion with patients who were TID-negative with normal perfusion., Conclusion: The presence of TID with an otherwise normal SPECT MPI study does not translate into a greater extent of coronary artery disease as assessed by cardiac CT or increased risk for future major adverse cardiac events., (© 2014 by the Society of Nuclear Medicine and Molecular Imaging, Inc.)

Rationale and Objectives: To investigate the impact of iterative reconstruction in image space (IRIS) on image noise, image quality (IQ), and postprocessing at coronary computed tomography angiography (cCTA) compared to traditional filtered back-projection (FBP)., Materials and Methods: The cCTA results of 50 patients (26 men; 58 ± 15 years, body mass index 31.5 ± 6.7 kg/m²) were investigated using a second-generation dual-source computed tomography system. Scan data were reconstructed with the use of IRIS and FBP algorithms. Two radiologists independently evaluated the reconstructions using automated coronary tree analysis software. Image noise was measured and IQ was rated on a 5-point Likert scale. The number of manual corrections after automated vessel segmentation, the time required to complete segmentation, and the number of missed segments were assessed in both IRIS and FBP reconstructions. Results were compared using paired t-test., Results: IRIS significantly reduced image noise compared to FBP (23.3 ± 8.8 vs. 33.5 ± 13.5 Hounsfield units, P < .001). Subjective IQ improved with IRIS (IRIS 3.2 ± 1.0 vs. FBP 3.0 ± 1.0, P < .05). IRIS decreased the time needed for coronary segmentation from 111.9 ± 40.5 seconds to 95.2 ± 38.2 seconds with FBP (P < .01) and required fewer manual corrections (5.7 ± 3.0 vs. 6.8 ± 3.6, P < .01). The number of missed vessel segments was not significantly different (3.6 ± 1.8 vs. 3.8 ± 1.9, P > .05) between IRIS and FBP, respectively., Conclusions: During cCTA postprocessing, IRIS significantly decreases the time and the number of manual corrections for a complete coronary segmentation compared to FBP. This effect is likely attributable to suppression of image noise by IRIS, which improves the performance of automated vessel segmentation and positively impacts cCTA analysis., (Copyright © 2014 AUR. Published by Elsevier Inc. All rights reserved.)

Objectives: This study sought to determine whether hyperoxemic reperfusion with aqueous oxygen (AO) improves recovery of ventricular function after percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI)., Background: Hyperbaric oxygen reduces myocardial injury and improves ventricular function when administered during ischemia-reperfusion., Methods: In a prospective, multicenter study, 269 patients with acute anterior or large inferior AMI undergoing primary or rescue PCI (<24 h from symptom onset) were randomly assigned after successful PCI to receive hyperoxemic reperfusion (treatment group) or normoxemic blood autoreperfusion (control group). Hyperoxemic reperfusion was performed for 90 min using intracoronary AO. The primary end points were final infarct size at 14 days, ST-segment resolution, and delta regional wall motion score index of the infarct zone at 3 months., Results: At 30 days, the incidence of major adverse cardiac events was similar between the control and AO groups (5.2% vs. 6.7%, p = 0.62). There was no significant difference in the incidence of the primary end points between the study groups. In post-hoc analysis, anterior AMI patients reperfused <6 h who were treated with AO had a greater improvement in regional wall motion (delta wall motion score index = 0.54 in control group vs. 0.75 in AO group, p = 0.03), smaller infarct size (23% of left ventricle in control group vs. 9% of left ventricle in AO group, p = 0.04), and improved ST-segment resolution compared with normoxemic controls., Conclusions: Intracoronary hyperoxemic reperfusion was safe and well tolerated after PCI for AMI, but did not improve regional wall motion, ST-segment resolution, or final infarct size. A possible treatment effect was observed in anterior AMI patients reperfused <6 h of symptom onset.

Objectives: The objectives of the study were to test the hypothesis that hyperbaric levels of oxygen enhance the sensitivity of a sarcoma cell line to doxorubicin (Adriamycin) both in vitro and in vivo in a rat model of pulmonary metastases and to test the feasibility of arterialization of mixed venous blood by direct injection of aqueous oxygen into the pulmonary artery in a rat model., Methods: Rat sarcoma (MCA-2) cells were incubated in the presence of increasing concentrations of doxorubicin (0.1-2.0 micromol/L). A dose-dependent toxicity relationship at 12 hours of treatment was examined with and without pretreatment with hyperbaric oxygen (3.7 atm absolute for 1.5-3.5 hours). In vivo, Sprague-Dawley rats (n = 24) were injected intravenously with 10(6) MCA-2 cells, and the lung tumors were allowed to mature for 14 days. At that time the animals were divided into four groups: control (no treatment), doxorubicin at 2 mg/kg, hyperbaric oxygen (oxygen at 2 atm absolute for 30 minutes), and hyperbaric oxygen plus doxorubicin. Seven days after treatment, the numbers of lung nodules were counted and the lung weights were determined. In additional rats (n = 7), aqueous oxygen (1 mL oxygen/g saline solution) was infused into the pulmonary artery to determine whether arterialization of mixed venous blood was comparable to pulmonary artery oxygenation with a hyperbaric chamber (n = 7)., Results: Hyperbaric oxygen plus doxorubicin produced significantly greater cytolysis of MCA-2 cells (P <.01) than did doxorubicin alone. Hyperbaric oxygen plus doxorubicin also significantly decreased the number of lung metastases and the lung weight relative to doxorubicin alone (P <.01 and P <.01, respectively). The feasibility of arterialization of mixed venous blood (>100 mm Hg) with aqueous oxygen infusion was demonstrated., Conclusions: Hyperbaric oxygen enhanced the chemotherapeutic effect of doxorubicin both in cell culture and in the rat model. Aqueous oxygen infusion can be used to oxygenate mixed venous blood at levels similar to those obtained with the use of a hyperbaric chamber.

Objectives: The purpose of the study was to test the hypothesis that intracoronary aqueous oxygen (AO) hyperbaric reperfusion reduces myocardial injury after prolonged coronary occlusion. Background. Attenuation of ischemia/reperfusion injury by the use of hyperbaric oxygen (HBO) administered during reperfusion has been demonstrated for a wide variety of tissues, including myocardium. We have recently developed a more practical, catheter-based, site-specific method for delivery of oxygen at hyperbaric levels with aqueous oxygen infusion., Methods: Following a 60-minute balloon occlusion of the left anterior descending coronary artery in swine, intracoronary AO hyperoxemic perfusion (50 mL blood/minute; 1.5 mL AO/minute; mean pO2 = 834 104 mmHg) was performed for 90 minutes after a 15-minute period of normoxemic autoreperfusion (physiologic reperfusion). Control groups consisted of autoreperfusion alone; active normoxemic perfusion (50 mL/minute) for 90 minutes; and hyperoxemic perfusion with a hollow fiber oxygenator (HFO) for 90 minutes. Results. A significant improvement in left ventricular ejection fraction was noted by ventriculography at 105 minutes of reperfusion (ANOVA, p < 0.05), compared to the 15-minute autoreperfusion period, only in the AO and HFO groups. Mean percent infarct size (area of necrosis)/(area at risk), quantitative post-mortem hemorrhage score, and myocardial myeloperoxidase levels at 3 hours of reperfusion were significantly less in the AO group (ANOVA, p < 0.05), but not in the HFO group, compared to normoxemic groups. Conclusions. The results demonstrate that intracoronary hyperbaric reperfusion with AO, but not with a membrane oxygenator, attenuates myocardial ischemia/reperfusion injury.

Electron cryomicroscopy and icosahedral reconstruction are used to obtain the three-dimensional structure of the 1250-A-diameter herpesvirus B-capsid. The centers and orientations of particles in focal pairs of 400-kV, spot-scan micrographs are determined and iteratively refined by common-lines-based local and global refinement procedures. We describe the rationale behind choosing shared-memory multiprocessor computers for executing the global refinement, which is the most computationally intensive step in the reconstruction procedure. This refinement has been implemented on three different shared-memory supercomputers. The speedup and efficiency are evaluated by using test data sets with different numbers of particles and processors. Using this parallel refinement program, we refine the herpesvirus B-capsid from 355-particle images to 13-A resolution. The map shows new structural features and interactions of the protein subunits in the three distinct morphological units: penton, hexon, and triplex of this T = 16 icosahedral particle.

Background: High levels of hyperoxemia may have utility in the treatment of regional tissue ischemia, but current methods for its implementation are impractical. A catheter-based method for infusion of O2, dissolved in a crystalloid solution at extremely high concentrations, ie, 1 to 3 mL O2/g (aqueous oxygen [AO]), into blood without bubble nucleation was recently developed for the potential hyperoxemic treatment of regional tissue ischemia., Methods and Results: To test the hypotheses that hypoxemia is correctable and that hyperoxemia can be produced locally by AO infusion, normal saline equilibrated with O2 at 3 MPa (30 bar; 1 mL O2/g) was delivered into arterial blood in two different animal models. In 15 New Zealand White rabbits with systemic hypoxemia, AO was infused into the midabdominal aorta at 1 g/min. Mean distal arterial PO2 increased to 236+/-113 and 593+/-114 mm Hg on 1-hour periods of air and O2 breathing, respectively, from a baseline of 70+/-10 mm Hg (P<.01). In contrast, infusion of ordinary normal saline in a control group (n=7) had no effect on arterial PO2. No differences between groups (P>.05) in temporal changes in blood counts and chemistries were identified. In 10 dogs, low coronary blood flow in the circumflex artery was delivered with a roller pump through the central channel of an occluding balloon catheter. Hypoxemic, normoxemic, and AO-induced hyperoxemic blood perfusates (mean PO2, 52+/-4, 111+/-22, and 504+/-72 mm Hg, respectively) were infused for 3-minute periods in a randomized sequence. Short-axis two-dimensional echocardiography demonstrated a significant decrease (P<.05) in left ventricular ejection fraction compared with baseline physiological values with low-flow hypoxemic and normoxemic perfusion but not with low-flow hyperoxemic perfusion., Conclusions: Intra-arterial AO infusion was effective in these models for regional correction of hypoxemia and production of hyperoxemia.

A 37-year-old man, who had received 3 weeks of antimicrobial therapy for aortic value endocarditis, presented with an acute anteroseptal wall myocardial infarction. Coronary angiography demonstrated occlusion of the mid left anterior descending artery, thought to have been caused by embolization of a sterile vegetation. Following failure of balloon dilation to achieve vessel patency, this was achieved by placement of an intracoronary stent.

The adjoint form of the photon transport equation is applied to a generalized fluorescence detection problem, and its accuracy is empirically tested. This approach can be interpreted as mathematically reversing the temporal flow of fluorescent photons; that is, they are tracked from the detector back to potential sites of origin in the scattering medium. The result is a distribution of potential fluorescing sites that, when properly normalized, gives a probability field of the relative importance of the photon starting position and direction to the resulting signal. This adjoint solution can be combined with the temporally forward-derived distribution of absorbed excitation photons to evaluate the fluorescence excitation detection scheme. This bypasses the normal, temporal derivation wherein the fluorescence transport solution is dependent on the result of the excitation transport solution.

This study was designed to assess the potential relationship between the late loss of angiographic luminal diameter and biochemical abnormalities of arterial wall collagen in rabbits subjected to angioplasty, and to test the hypothesis that beta-aminopropionitrile (beta APN), an inhibitor of lysyl oxidase, would inhibit such changes when administered orally for 1 mo after angioplasty. Endovascular injury was induced in rabbit iliac arteries by ipsilateral balloon angioplasty (BA) and by contralateral balloon angioplasty accompanied by exposure to continuous wave neodymium: yttrium aluminum garnet laser radiation (LBA). Computer measurement of angiographic luminal diameter demonstrated significant vessel narrowing at 1 and 6 mo after both procedures. By quantitative histology, the majority of the 1-mo loss in angiographic diameter could not be attributed to neointimal thickening. Analysis of collagen cross-linking by HPLC in collagen obtained from the LBA-injured segments of the arteries 1 mo after angioplasty revealed a significant increase, relative to values from uninjured arteries (P < 0.05), in the difunctional cross-link dihydroxylysinonorleucine (DHLNL). 6 mo after angioplasty, the content of hydroxypyridinium, the trifunctional maturational product of DHLNL, was significantly elevated in both BA- and LBA-treated arteries compared with values from uninjured arteries (P < 0.05). In animals administered beta APN, luminal narrowing at 1 mo, compared with controls, was attenuated (P < 0.01) and DHLNL content was decreased (P < 0.05) in arteries subjected to LBA, but not in arteries subjected to BA. The results suggest that lathyrogenic agents may be efficacious in favorably modulating LBA-induced alterations in vessel diameter and mural connective tissue.

Background: Radiofrequency catheter ablation of left-sided accessory pathways is becoming the first line of therapy for patients with symptomatic Wolff-Parkinson-White syndrome. Nevertheless, alternative ablation techniques merit development, at least as supplementary modalities for cases in which conventional ablation approaches may prove unsuccessful. We recently reported the short-term results with transcatheter laser balloon ablation from the coronary sinus in a canine model, proving that the procedure is feasible for the potential ablation of left-sided accessory pathways. We now report the effects of percutaneous transcatheter laser balloon ablation in a chronic canine model., Methods and Results: Twenty adult mongrel dogs were studied. After baseline coronary arteriography, left ventriculography, and coronary sinus angiography were obtained, 15 dogs received two or three consecutive laser doses from the coronary sinus of 30-40 W for 15-30 seconds, for a total cumulative energy of 1,200-2,400 J. The five remaining animals underwent a procedure consisting of balloon sham inflation without laser exposure and served as controls. After a mean follow-up of 6 weeks, the angiographic procedures were repeated, and the animals were killed. The mean extent of the fibrotic lesion was 15 mm long, 6 mm wide, and 4.5 mm deep and involved the coronary sinus wall, atrium, and, frequently, the summit of the posterior left ventricular wall. Six animals (four in the study group and two in the control group) showed asymptomatic narrowing of the coronary sinus lumen but always with total angiographic reconstitution due to extensive collateral circulation. The circumflex artery and mitral valve were intact angiographically and histologically in all animals., Conclusions: Percutaneous transcatheter laser balloon ablation via the coronary sinus produces a lesion that may be anatomically well suited for left-sided accessory pathway ablation. Although coronary sinus narrowing may occur, adverse physiological effects are unlikely due to the development of extensive collateral circulation. Systematic clinical studies of this new approach to catheter ablation appear warranted.

To determine whether anesthesiologists can manually detect significant changes in pulmonary compliance in neonates using an "educated hand," the authors tested whether clinicians could detect clamping of an endotracheal tube connecting a neonatal lung model to one of three anesthesia breathing circuits. The test lungs corresponded to the lung of a full-term neonate (large lung) or a premature neonate (small lung), and the circuits were a disposable Mapleson D and a disposable pediatric circle system with and without a humidifier. Clinicians having four levels of expertise (inexperienced anesthesia residents, experienced anesthesia residents, faculty not specializing in pediatric anesthesia, and specialized pediatric anesthesia faculty) were permitted to choose fresh gas flows, ventilatory pattern, and rate. After an acclimation period, the endotracheal tube connecting the test lung to the circuit was occluded once for 30 s. Clinicians were credited with a successful detection if they reported the occlusion within 15 s and had fewer than one false positive per minute. With the large lung model, only 4 of 24 clinicians detected occlusion with the Mapleson D circuit; similar results were obtained with the other circuits. With the small lung model, the only successful detection occurred with the Mapleson D circuit. Success at detecting occlusion was similarly low for clinicians with different levels of expertise. The authors conclude that the commonly held belief that the "educated hand" permits clinicians to detect subtle changes in pulmonary compliance in neonates during anesthesia (necessitating manual rather than mechanical ventilation) is not true.

Mitigation of adverse biologic reactivity after balloon angioplasty is necessary before the incidence of restenosis can be appreciably reduced. A brief review of experimental evidence supports the hypothesis that the thrombogenicity of the injured arterial wall can be reduced by a suitable level of thermal denaturation or cross-linking of thrombogenic proteins. In addition, the concept of local pharmacologic therapy, which can be provided with laser balloon angioplasty at the site of arterial injury, is introduced. Preliminary in vitro and in vivo data suggest that guide catheter-injected albumin-heparin conjugates fabricated as water-insoluble microspheres remain adherent to the injured luminal surface and deeper arterial layers after physical trapping by the inflated balloon and subsequent laser/thermal exposure. The combination of initially adequate luminal morphology, reduction of the thrombogenicity of the injured arterial wall and application of local pharmacologic therapy with laser balloon angioplasty may eventually prove helpful in reducing the incidence of restenosis.

A multicenter clinical trial was initiated to test the potential safety and short-term efficacy of a percutaneous coronary application of laser balloon angioplasty, which has been shown experimentally to alleviate the common causes (dissection, recoil, thrombus) of suboptimal luminal results of conventional balloon angioplasty. Fifty-five patients, the majority (62%) of whom had relatively high risk lesions, were treated in 10 centers with a laser balloon that was identical in size (3 x 20 mm) to a balloon used for conventional balloon angioplasty performed on the same lesion immediately before laser balloon angioplasty. One or more neodymium:yttrium aluminum garnet (Nd:YAG) (1,060 nm) laser doses of 250 to 450 J were each delivered over a 20 s duration per exposure. Immediately and 1 day after laser balloon angioplasty no significant adverse effects on the arterial lumen were noted in any patient. By computerized image analysis of cineangiograms initial conventional balloon angioplasty failed to achieve a minimal luminal diameter greater than 1.5 mm in 14 patients (25%), including 3 patients with acute closure. However, after subsequent laser balloon angioplasty, minimal luminal diameter exceeded this value in all patients including this subgroup. Overall, minimal luminal diameter increased from 1.74 +/- 0.46 mm after conventional balloon angioplasty to 2.32 +/- 0.31 mm after laser balloon angioplasty (p less than 0.001) with no change found on 1 day and 1 month follow-up angiograms. Thus, laser balloon angioplasty is a safe, effective procedure for improving luminal dimensions after conventional balloon angioplasty.

Abrupt coronary occlusion and long-term restenosis continue to be the major problems associated with percutaneous transluminal coronary angioplasty (PTCA). Laser balloon angioplasty (LBA) is a technique designed to potentially alleviate these problems by sealing arterial dissections, smoothing the luminal surfaces, dehydrating thrombi, and reducing the elastic properties that tend to recoil the stretched artery to its original state. During LBA, laser energy is delivered circumferentially by a 100-microns optical fiber that terminates in a central diffusing tip within an angioplasty balloon. LBA is performed for 20 seconds during the final inflation of the angioplasty balloon. Achieved with decremental ramped laser dosimetry, Nd:YAG laser energy has been shown to be effective in welding experimental arterial dissections over a therapeutic temperature range of 95 degrees-120 degrees C. LBA treatment of rabbit iliac arteries has been superior to balloon angioplasty in inhibiting elastic recoil and causing acute and long-term luminal increment. LBA has also been effective for sealing acute dissections in atherosclerotic rabbit iliac arteries. Additionally, in a canine model, safety in the coronary circulation has been shown, that is, even at 1 month after LBA, angiography demonstrated a cast of the LBA balloon without luminal compromise. Since March 1988, more than 250 patients with symptomatic coronary artery disease have been treated with LBA with nearly uniform clinical success, including frequent reversal of abrupt closure. LBA seems to be a safe modality that may decrease the need for emergency operative procedures and late coronary revascularization after PTCA.

Fluorescence of hematoporphyrin derivative (HPD) has been used clinically to localize malignant neoplasms because of its selective accumulation in these tissues. We tested the hypothesis that HPD may also be selectively concentrated within atheromatous plaques. 48 h after HPD injection in a variety of species, selective fluorescence of atheromatous plaques of the aorta was seen in each animal (rabbits and Patas monkey) exhibiting such lesions. No fluorescence could be demonstrated in aortic segments free of atheromatous involvement. Since the efficacy of photodynamic destruction of malignant tumors with HPD has been demonstrated in clinical studies, the observations of the present study may have therapeutic implications in atheromatosis.

Drugs that localize in valvular vegetations may be useful in the diagnosis and treatment of infective endocarditis. We therefore tested the hypothesis that parenterally injected hematoporphyrin derivative (HPD), which is concentrated in tumors and atherosclerotic plaques, localizes in the vegetations of experimental infective endocarditis. In 14 rabbits, various bacteria were given intra-arterially immediately after injury to the aortic valve. In 12 additional rabbits, sterile vegetations on the aortic valve were produced by the trauma caused by an indwelling catheter that had been in place over a long period. HPD, 2.5 mg/kg, was injected intravenously 1 to 2 days before the animals were killed in six rabbits with sterile vegetations and in seven rabbits with infected vegetations. In all rabbits, multiple vegetations on the aortic valve leaflets were identified. On exposure to ultraviolet light, strong porphyrin fluorescence of all vegetations, whether sterile or infected, was observed only in rabbits given HPD. In two rabbits given HPD 10 weeks after catheter implantation across the aortic valve, however, only mild fluorescence could be detected in healing endocardial vegetations. In frozen sections of HPD-laden lesions, a patchy distribution of fluorescence was observed that was similar to the pattern of HPD localization in atheromatous plaques. Since vegetations in experimental infective endocarditis selectively concentrate HPD, porphyrins could be useful in the diagnosis and treatment of infective endocarditis.

The feasibility of in vivo coronary angioscopy was tested utilizing a 1.8 mm angioscope in vessels where blood had been replaced by optically clear liquids, including a new perfluorocarbon emulsion. After trials in postmortem canine and human coronary arteries, in vivo intraluminal visualization was accomplished in the dog with a catheterization technique and in patients during open heart surgery. The results demonstrate the feasibility and potential clinical usefulness of direct visualization of intravascular anatomy and disease, analogous to endoscopy of other organ systems.

Coronary angioscopy should permit direct inspection of the luminal cross section and identification of disease. The feasibility of introducing a 5F Olympus Ultrathin fiberscope into the obstructed right coronary artery in five patients after routine cardiac catheterization by the brachial approach was therefore tested. An 8.3F USCI woven Dacron angioplasty guiding catheter was modified to enlarge its lumen. After engaging the right coronary ostium with the catheter, an attempt was made to pass the angioscope coaxially to the tip of the catheter. Visualization of the coronary lumen was then achieved in three patients by manually injecting 5 to 10 cc of normal saline solution through the guiding catheter at 2 to 3 cc/s. White atheromatous plaque could be seen near the site of obstruction in each case. In two patients, a lack of sufficient flexibility in the distal 2 cm of the angioscope prevented passage to the catheter tip. Preliminary experience with a videoendoscopic system suggests that this monitoring technique is essential for the adequate performance of angioscopy and for recording dynamic changes during blood displacement. Geometric distortion of the image and nonlinearities in magnification and light reflex with a decreasing lens to object distance make quantitative evaluation of the lumen difficult. Lack of an angulation system further contributes to this problem and, more importantly, restricts passage of the angioscope to the proximal 1 to 2 cm segments of coronary arteries. Although coronary angioscopy may have research and clinical applications in the future, these technical problems should first be addressed.

Subjective estimates of the angiographic severity of coronary artery stenoses show variability and inaccuracy. We therefore tested the accuracy of a newly developed computerized image analysis system for quantitating vessel diameter from cineangiograms. Fourteen cylindrical phantoms of known diameter were filled with contrast medium and filmed over a wide range of clinically relevant radiographic conditions in order to develop regression equations that related computer-derived to anatomic diameters. Computer measurements of vessel diameter were unaffected by vessel size, magnification, focal spot size, thickness of scattering medium, kilovolt peak, or location within the radiographic field, but a correction factor was necessary for a small but significant (p less than .01) linear dependence on contrast medium concentration. The accuracy of computerized vessel diameter measurements ranged between +/- 59 and +/- 137 mu for all conditions except for rapid vessel motion and contrast medium concentrations of 50% or less meglumine diatrizoate (Renografin 76), both of which resulted in reduced accuracy as well as in the inability to locate lumen edges of vessels less than 1 mm in diameter.

The feasibility of using continuous on-line recording of intraventricular electrical impedance to measure ventricular stroke volume was assessed in 12 patients at cardiac catheterization with a multielectrode impedance catheter and a 1.3 kHz measuring current of 4 microA. Stroke volumes determined by electrical impedance were compared with stroke volumes determined by the thermodilution technique in 10 patients and correlated with an r value of .95. Directional changes in impedance recordings throughout the cardiac cycle were also compared with volume curves obtained from six patients by radionuclide ventriculography, and in all instances the agreement between the two volume recordings was excellent. For all patients, on-line measurements of impedance showed a beat-by-beat decrease in stroke volume with the Valsalva maneuver and the administration of amyl nitrite, as well as an immediate increase in stroke volume in the contraction following an extra-systolic beat. Similar directional changes in stroke volume were recorded in both left and right ventricles. Left ventricular pressure-volume relationships were assessed with simultaneous left ventricular pressure recordings and volume signals recorded from the impedance catheter to determine if impedance measurements of volume can be used clinically. Pressure-volume diagrams were subsequently plotted, and for all patients these diagrams showed characteristic isovolumetric contraction and relaxation phases as well as typical ejection and filling periods. Moreover, beat-by-beat sequential pressure-volume diagrams constructed for patients during the administration of amyl nitrite revealed a linear end-systolic pressure-volume relationship.(ABSTRACT TRUNCATED AT 250 WORDS)

Hematoporphyrin derivative, a photosensitive material used to identify and treat neoplastic tissue in humans, has been found to localize in atheromatous plaques in animals and has recently been found in postmortem human atherosclerotic plaques. It is not known whether human plaques take up hematoporphyrin derivative in vivo. In five patients undergoing surgical vascular procedures, specimens containing atheromatous plaques were removed and immediately incubated in autologous oxygenated blood at 37 degrees C with hematoporphyrin derivative at a clinically relevant concentration for 2 hours. On exposure to ultraviolet light, porphyrin fluorescence was noted throughout each plaque, whereas adjacent plaque-free tissue showed no fluorescence. To compare in vitro with in vivo hematoporphyrin derivative uptake by plaques, the fluorescence of three types of arterial lesions (induced by a high cholesterol diet, catheters or balloon injury) was studied in 16 New Zealand White rabbits. Each lesion fluoresced selectively with the same intensity whether hematoporphyrin derivative exposure was performed in vitro or in vivo. Fluorescence microscopy did not show a difference in the pattern of hematoporphyrin derivative fluorescence between in vitro and in vivo specimens. The results suggest that human atheromatous plaques should take up hematoporphyrin derivative in vivo and are, therefore, potentially suitable for photochemical treatment as a new therapeutic approach to atherosclerosis.

Widespread arteriosclerotic lesions were detected by histological examinations of rats killed at seven or nine weeks after an intrarenal (ir) injection of nickel subsulfide (Ni3S2, 5 mg per rat). Arteriosclerotic plaques were readily visualized by administering hematoporphyrin derivative (HPD) iv to rats at 24 hours before sacrifice. At necropsy, the major arteries were inspected under ultraviolet light, revealing patches of intense HPD-fluorescence in the arterial endothelium of Ni3S2-treated rats, but not in control rats. Consistent with previous reports, the Ni3S2-treated rats developed pronounced erythrocytosis; blood hematocrit values averaged 70 +/- 4 percent at seven weeks after ir injection of Ni3S2 (P less than 0.001 vs corresponding value of 49 +/- 2 percent in vehicle controls). At seven weeks, blood platelet counts averaged 17 percent lower and serum glucose concentrations averaged 23 percent lower in Ni3S2-treated rats than in controls; serum lipids, lipoproteins, non-protein nitrogen constituents, electrolytes, proteins, and enzymes were not significantly affected. Body weights and systolic blood pressures of rats at two, four, and six weeks after ir injection of Ni3S2 did not differ from corresponding values in controls. Addition of egg yolk to the diet caused mild hypercholesterolemia, but it did not enhance the incidence or severity of arterial lesions in Ni3S2-treated rats. These findings exclude hypertension and hyperlipidemia as pathogenic factors in Ni3S2-induced arteriosclerosis.