Evaporative cooling and coherent axial oscillations of highly charged ions in a penning trap.

Externally, in an electron beam ion trap, generated Ar16+ ions were retrapped in a Penning trap and evaporatively cooled in their axial motion. The cooling was observed by a novel extraction technique based on the excitation of a coherent axial oscillation which yields short ion bunches of well-defined energies. The initial temperature of the ion cloud was decreased by a factor of more than 140 within 1 s, while the phase-space density of the coldest extracted ion pulses was increased by a factor of up to about 9.

New mass value for 7Li.

A high-accuracy mass measurement of 7Li was performed with the SMILETRAP Penning-trap mass spectrometer via a cyclotron frequency comparison of 7Li3+ and H2+. A new atomic-mass value of 7Li has been determined to be 7.016 003 425 6(45) u with a relative uncertainty of 0.63 ppb. It has uncovered a discrepancy as large as 14sigma (1.1 microu) deviation relative to the literature value given in the Atomic-Mass Evaluation AME 2003. The importance of the improved and revised 7Li mass value, for calibration purposes in nuclear-charge radii and atomic-mass measurements of the neutron halos 9Li and 11Li, is discussed.

Angiographic predictors of graft patency and disease progression after coronary artery bypass grafting with arterial and venous grafts.

BACKGROUND: There are few data about angiographic determinants of functional graft patency and native artery disease progression after coronary artery bypass grafting operation with arterial grafts compared with venous grafts. METHODS: Baseline and follow-up coronary angiograms at a mean of 2 years after operation in 91 patients with 194 arterial and 204 venous graft anastomoses were analyzed. RESULTS: Ninety-two percent of the arterial and 87% of the venous graft anastomoses were patent at follow-up angiography (p = 0.05, odds ratio = 2.63). Unlike that of arterial grafts, the patency rate of venous graft anastomoses correlated negatively with decreasing severity of the bypassed lesion. In contrast to venous grafts, in which angiographic graft function was basically dichotomous (fully patent or occluded), compromised flow of the arterial graft anastomoses was registered in 12%. Progression of the disease was more common in segments bypassed with venous grafts than with arterial grafts (p = 0.001, odds ratio = 2.03). CONCLUSIONS: Angiographic determinants of functional graft patency and progression of occlusive changes in the bypassed artery segments are different for arterial and venous grafts.

Medial artery calcification. A neglected harbinger of cardiovascular complications in non-insulin-dependent diabetes mellitus.

Medial artery calcification (MAC) is a nonobstructive condition leading to reduced arterial compliance that is commonly considered as a nonsignificant finding. The aim of our study was to investigate the predictive value of MAC in relation to 7-year cardiovascular mortality, coronary heart disease (CHD) events, stroke, and lower extremity amputation in 1059 patients (581 men and 478 women) with non-insulin-dependent diabetes mellitus (NIDDM). At baseline radiologically detectable MAC in femoral arteries was found in 439 patients (41.5%) and intimal-type calcification in 310 diabetic patients (29.3%). The mean fasting plasma glucose at baseline was somewhat higher in women and the duration of diabetes somewhat longer in patients with MAC than in those without, but otherwise the presence of MAC was unrelated to conventional cardiovascular risk factors. During the follow-up 305 diabetic patients died: 208 from cardiovascular disease, 158 from CHD, and 34 from stroke. Furthermore, 58 NIDDM patients underwent their first lower extremity amputation. MAC was a strong independent predictor of total (risk factor-adjusted odds ratio and 95% confidence interval: 1.6; 1.2, 2.2), cardiovascular (1.6; 1.1, 2.2), and CHD (1.5; 1.0, 2.2) mortality, and it was also a significant predictor of future CHD events (fatal or nonfatal myocardial infarction), stroke, and amputation. This relationship was observed regardless of glycemic control and known duration of NIDDM. MAC is a strong marker of future cardiovascular events in NIDDM unrelated to cardiovascular risk factors, supporting the hypothesis that reduced arterial elasticity could lead to clinical manifestations of diabetic macroangiopathy.

Color Doppler imaging of the ophthalmic artery blood flow spectra of patients who have had a transient ischemic attack. Correlations with generalized iris transluminance and pseudoexfoliation syndrome.

PURPOSE: To study the interrelations among pseudoexfoliation syndrome (PXS), abnormal iris transluminance, and ophthalmic artery blood flow in a controlled study. METHODS: Ultrasonographic examination using color Doppler imaging (CDI) was performed on the ophthalmic arteries of 46 unselected patients (92 eyes) who have had at least one transient ischemic attack (TIA) and on 32 healthy subjects (64 eyes). The authors recorded the peak systolic and end diastolic velocities and determined the resistivity indices. Iris transillumination photographs were evaluated by two ophthalmologists in a blind trial to show the presence of abnormal iris transluminance of these eyes. Biomicroscopic examination was performed to show the presence of PXS. RESULTS: The frequency of abnormal iris transluminance in the whole group of patients who had had a TIA and in control subjects was 63% and 28%, respectively (P < 0.05). Pseudoexfoliation syndrome was found in 41% of the right eyes and in 43% of the left eyes in the group of patients who had had a TIA. The difference between the resistivity indices for the ophthalmic arteries of patients who had had a TIA with positive iris transluminance and healthy subjects without transluminance was statistically significant (P < 0.05, Student's t test). Pseudoexfoliation syndrome was detectable in 55.6% of the right eyes and in 61.5% of the left eyes of patients who had had a TIA with abnormal iris transluminance. CONCLUSION: The exceptionally high frequency of PXS in the eyes of patients who had had a TIA with positive iris transluminance suggests pathologic changes in the blood supply of PXS eyes. High values of resistivity indices for the ophthalmic arteries of these eyes suggest that disturbances in the ciliary circulation may be the possible cause of these changes.

Gastroepiploic artery as an in situ coronary artery bypass graft: evaluation of MRI and colour Doppler ultrasound in follow-up.

The right gastroepiploic artery, increasingly used as an in situ coronary artery bypass graft, has good long-term patency. This study aimed to assess the accuracy and limitations of magnetic resonance imaging (MRI) and colour Doppler ultrasound (US) in postoperative follow-up of such cases. In eight consecutive patients (6 men, 2 women, mean age 57 years), conventional angiography, MRI and US were performed to evaluate graft patency. Colour Doppler US, performed within a week of the operation, correctly detected flow in three patent grafts. MRI (1.5 tesla) was performed c. 17 months after surgery, using a spine coil and a coronal two-dimensional Flash-type imaging sequence. At angiography six of the eight gastroepiploic artery grafts were patent, and two were occluded. The sensitivity and specificity of MRI were 100%. This accuracy makes MRI a promising method for noninvasive post-operative evaluation of right gastroepiploic artery graft patency.

Medial artery calcification predicts cardiovascular mortality in patients with NIDDM.

OBJECTIVE: To study the predictive value of medial artery calcification (Mönckeberg's sclerosis) in relation to 10-year cardiovascular mortality in patients with non-insulin-dependent diabetes mellitus (NIDDM). RESEARCH DESIGN AND METHODS: We studied the predictive value of thigh medial and intimal artery calcifications to 10-year cardiovascular mortality in a well-characterized group of 133 middle-aged, newly diagnosed patients with NIDDM (70 men and 63 women). RESULTS: At baseline, medial artery calcifications were found in 17% of the patients and intimal-type calcifications were found in 23%. During the follow-up, 21% of the diabetic patients died from cardiovascular causes. The age-adjusted odds ratio for cardiovascular mortality was 4.2 (95% confidence intervals: 1.5-11.3) for medial-type and 1.6 (0.6-4.3) for intimal-type calcifications. In multiple logistic regression analysis, including age, sex, systolic blood pressure, low-density- and high-density-lipoprotein cholesterol, very-low-density lipoprotein triglycerides, smoking, body mass index, fasting serum insulin, blood glucose, urinary albumin, and ischemic ECG changes, as well as the intimal artery calcification, the medial artery calcification was the dominant factor predicting cardiovascular mortality. CONCLUSIONS: In this study medial artery calcification was a strong independent predictor of cardiovascular mortality in patients with newly diagnosed NIDDM. Whether these subjects had a longer duration of hyperglycemia before the diagnosis than those without medial artery calcifications remains unknown.

Femoropopliteal angioplasty in patients with claudication: primary and secondary patency in 140 limbs with 1-3-year follow-up.

PURPOSE: To determine the usefulness of percutaneous transluminal angioplasty in the femoropopliteal arteries in patients with claudication. MATERIALS AND METHODS: In a prospective study of 106 claudicants (71 men and 35 women, aged 41-90 years [mean, 67 years]), a total of 208 lesions in 140 limbs were treated. The patients were followed up for 12-36 months. The patency rates were based on determination of the ankle-brachial index. RESULTS: The hemodynamic success rate for all the treated limbs was 89%, 99% for femoropopliteal stenoses (n = 71) and 80% for femoropopliteal occlusions (n = 69). In multiple logistic regression analysis, a smaller number of diseased vessels (one to two vs three to seven) and milder lesion severity (stenosis vs occlusion) correlated favorably with early success. Survival analysis with the Kaplan-Meier method according to established criteria revealed 1-, 2-, and 3-year primary patency rates of 47% (27 of 57 limbs), 41% (14 of 34 limbs), and 43% (three of seven limbs), respectively. CONCLUSION: In selected cases, good primary success and acceptable long-term results can be achieved with femoropopliteal angioplasty in claudicants.

Chronic critical lower-limb ischemia: prospective trial of angioplasty with 1-36 months follow-up.

To determine the utility of percutaneous transluminal angioplasty (PTA) in the treatment of chronic critical lower-limb ischemia, a prospective study of 103 consecutive patients (117 limbs) was performed. Patients underwent PTA for a total of 209 lesions in the iliac (n = 4), femoropopliteal (n = 121), and infrapopliteal (n = 84) arteries and were followed up for 1-36 months (mean, 12 months). The primary technical success rate was 92% for stenosis and 80% for occlusion. Survival analysis with the Kaplan-Meier method revealed 1-, 2-, and 3-year limb salvage rates of 56%, 49%, and 49%, respectively. The following factors correlated favorably with limb salvage in Cox multiple regression analyses: a small number of diseased lower-limb vessels (one to five vs six to eight) and treated lesions per limb (one or two vs three to five), achieved peripheral runoff (one to three patent calf vessels vs none), and an occlusion as the successfully treated target lesion (instead of stenosis).

Ultrasound-facilitated central venous cannulation.

OBJECTIVE: To compare the conventional method for cannulation of the internal jugular vein with the ultrasound-aided technique. DESIGN: Prospective, randomized trial. SETTING: Medical and surgical patients requiring central cannulation in a university hospital. PATIENTS: Consecutive medical and surgical patients in whom central venous cannulation was indicated. INTERVENTIONS: Cannulation of the internal jugular vein was performed by one anesthesiologist. During the first 6 months, the ultrasound-aided technique (n = 29) was used, and during the second 6 months, the conventional technique (n = 27) was applied. MEASUREMENTS AND MAIN RESULTS: The venous lumen was reached with fewer punctures (1.2 +/- 0.5 vs. 3.3 +/- 3.0 punctures per patient) and the cannulation time was shorter (35 +/- 19 vs. 198 +/- 211 secs) while using the ultrasound-aided technique. The ultrasound-aided method showed that the large-bore (diameter greater than 2.0 mm) needles invariably perforated the medial wall of the internal jugular vein, increasing the risk of perforating the adjacent carotid artery. CONCLUSIONS: Ultrasound guidance reduces both the duration of time and the number of punctures required to cannulate the internal jugular vein. The Seldinger technique appears safer for catheterization of the internal jugular vein.

Asymptomatic atherosclerosis and insulin resistance.

High plasma insulin has been shown to be associated with the risk of coronary heart disease in nondiabetic subjects in prospective population studies. Furthermore, insulin resistance measured by the euglycemic glucose clamp technique has been shown to be related to lipid and lipoprotein changes favoring atherosclerosis and to high blood pressure. No study, however, has demonstrated that insulin resistance per se is directly associated with atherosclerosis. With this aim, we studied 30 middle-aged nonobese subjects with asymptomatic atherosclerosis in the femoral or carotid arteries and 13 corresponding control subjects. Fasting blood glucose, insulin, and C-peptide levels were only slightly and nonsignificantly higher in subjects with atherosclerosis than in controls, and during the oral glucose tolerance test 1- and 2-hour glucose, insulin, and C-peptide levels were similar in both groups. During the euglycemic hyperinsulinemic (1,200 pmol/l) clamp studies, subjects with atherosclerosis had a 20% reduced whole-body glucose uptake (58 +/- 2 versus 71 +/- 4 mumol/kg/min, p = 0.004). Glucose oxidation, lipid oxidation, suppression of free fatty acid levels, and potassium disposal were similar in both groups. In contrast, nonoxidative glucose disposal was significantly reduced in patients compared with that in controls (37 +/- 2 versus 50 +/- 4 mumol/kg/min, p = 0.004). When glucose uptakes were matched during the hyperglycemic clamp studies, the rate of nonoxidative glucose uptake was normalized in the patients. These results provide the first direct evidence that asymptomatic atherosclerosis is associated with insulin resistance. This insulin resistance is characterized by reduced whole-body and nonoxidative glucose uptake. In contrast, glucose and lipid oxidation, potassium disposal, and suppression of free fatty acid levels during hyperinsulinemia did not differ between the subjects with and without atherosclerosis.

CO2 gas perfusion: improved efficiency and safety with sapphire-probe laser ablation of human artery.

CO2 gas has been proposed as a new perfusion medium for laser angioplasty. To compare CO2 gas with conventional saline perfusion, 146 fresh specimens of normal and atheromatous human artery were irradiated with a neodymium: yttrium-aluminum-garnet laser with a sapphire probe in flowing whole blood in an experimental circulation-occlusion model. The dimensions of the ablation crater and the extent of the surrounding tissue damage were measured microscopically. Significantly better ablation of atheromatous plaque was achieved with CO2 perfusion than with saline perfusion: mean ablation areas were 5.0 mm2 versus 2.8 mm2, respectively (P = .001, Student t test). In contrast, the ablation areas on normal vessel wall were identical (mean, 3.4 mm2) with the two perfusion media. Moreover, CO2 gas functioned as a negative contrast agent and facilitated direct monitoring of the laser recanalization procedure. On an experimental basis, CO2 gas perfusion seems to improve the efficiency and safety of laser ablation in human arteries.

Aortic and lower limb artery calcification in type 2 (non-insulin-dependent) diabetic patients and non-diabetic control subjects. A five year follow-up study.

The purpose of the present study was to assess among a representative group of middle-aged newly diagnosed type 2 diabetics and control subjects the baseline prevalence and 5-year incidence of arterial calcifications of aorta and lower limb and their relationship to cardiovascular morbidity. The relationship of baseline risk factors to the development of arterial calcifications was also studied. At the time of diagnosis the age-adjusted prevalence of aortic and lower limb intimal calcifications was higher in diabetics than in control subjects (aortic calcifications: 29 vs. 17% for men, P = 0.05; 26 vs. 19% for women, P = 0.06; lower limb intimal calcifications: 24 vs. 12% for men, P = 0.02; 10 vs. 7% for women; P = NS), whereas no significant difference in baseline prevalence of lower limb medial calcifications was observed (15 vs. 21% for men, 9 vs. 10% for women). The 5-yr incidence of aortic calcifications in both sexes and of lower limb calcifications in men was similar in diabetic and control subjects, but the incidence of lower limb calcifications was higher in diabetic women than in control women (intimal: 33 vs. 11%, P = 0.009: medial: 29 vs. 14%, P = 0.05). The baseline prevalence of abdominal aortic (37 vs. 22%, P = NS for diabetics; 42 vs. 16%, P = 0.02 for control subjects), lower limb intimal (24 vs. 16% for diabetics, P = NS; 15 vs. 7% for control subjects, P = NS) and medial calcifications (23 vs. 7% for diabetics, P = 0.03) were higher in subjects who developed intermittent claudication during the follow-up than in those free of it at the 5-yr examination. Abnormalities in VLDL-metabolism and high systolic blood pressure were associated with the development of aortic calcification in diabetic subjects. In conclusion, already at the time of diagnosis atherosclerotic calcifications are more prevalent in type 2 diabetics than in nondiabetic subjects. During the follow-up diabetic women, but not men, had higher incidence of lower limb intimal and medial calcifications than non-diabetic subjects. Arterial calcifications tended to be associated with the development of intermittent claudication during the follow-up in diabetic and control subjects.

Plasma insulin, serum lipids and lipoproteins in gall stone disease in non-insulin dependent diabetic subjects: a case control study.

Fasting insulin, lipids and lipoproteins were measured in 22 middle aged female non-insulin dependent diabetics with gall stone disease (cases) and in 22 non-insulin dependent diabetics without gall stone disease (controls). The groups were matched for sex, age, obesity, and fasting glucose concentrations. No differences were observed between the cases and controls in duration of diabetes, glycated haemoglobin A1, alcohol intake, smoking, use of cardiovascular drugs or a history of myocardial infarction. Diabetics with gall stone disease had higher fasting insulin concentrations (p less than 0.5), lower total (p less than 0.01) and low density lipoprotein cholesterol (p less than 0.01) and high density lipoprotein cholesterol (not statistically significant) concentrations than diabetics without gall stone disease. These changes in insulin, lipids and lipoproteins are similar to reported changes in non-diabetic subjects with gall stone disease. Therefore, they are characteristic for gall stone disease and not as such explanatory to an increased risk of gall stones in patients with non-insulin dependent diabetes.

Carbon dioxide gas as a perfusion medium for the sapphire probe in laser ablation of human atheromatous plaques: comparison study with saline.

The effectiveness of CO2 gas as a perfusion medium was compared to that of saline in laser ablation of human atheromatous plaque. In an experimental circulation-occlusion model using flowing whole blood, human cadaveric arterial samples were irradiated by a sapphire probe with the Nd-YAG laser. The following experiments were performed: 1) lasing without perfusion, 2) lasing with saline perfusion of the probe, and 3) lasing with CO2 perfusion. Different perfusion flow rates of saline and CO2 were used. Results showed that the mean ablation area was 1.6-fold larger with CO2 than with saline perfusion (P less than 0.05, Student's t test). The mean lateral injury at the site adjacent to the ablation crater and at the area directly facing the probe was not significantly different with either perfusion medium. The larger ablation area with CO2 was probably due to the fact that CO2 is a good insulator for maintaining a higher probe temperature and keeps the probe free of blood debris. In conclusion, our results show that CO2 perfusion facilitates more effective laser ablation of atheromatous plaque than saline perfusion by the sapphire probe with the continuous wave Nd-YAG laser.

Reversed left internal mammary artery graft for coronary bypass. Evaluation of function with digital subtraction angiography and radionuclide imaging.

Reversed left internal mammary artery grafting with retrograde flow to the left anterior descending coronary branch was used in five of 500 consecutive bypass operations. The indications were significant stenosis in the left subclavian artery (3 patients) or the proximal left internal mammary artery (1) and proximal damage to the left internal mammary artery during dissection from the thoracic wall (1). The postoperative clinical course was smooth in all five patients, with no evidence of myocardial ischemia. In follow-up averaging 14 months four patients were asymptomatic. The reversed internal mammary artery graft was visualized with digital subtraction angiography in four cases. Radionuclide imaging during exercise confirmed graft patency in all but the symptomatic patient, who was found to have an area of reversible ischemia anteriorly in the left ventricle.