High-resolution Ultrasound Scanning Research Articles

Preoperative Ultrasound Is Worthwhile for Reoperative Parathyroid Surgery

High-resolution ultrasound and sestamibi scanning are regarded as the first-line methods for preoperative localization of parathyroid adenomas. The utility of ultrasound in reoperative cases has been questioned because of concern that scarring will obscure normal tissue planes and vascularity that are critical to identification of an adenoma using this imaging modality. The purposes of the study were to evaluate the ability of high-resolution ultrasound to accurately localize parathyroid adenomas in the reoperative exploration and to identify any factors that influence its accuracy Retrospective chart review at a tertiary care academic medical center. All patients seen in referral for parathyroid surgery between May 1994 and September 2002 underwent high-resolution ultrasound as their initial diagnostic test. Patients who subsequently underwent exploration were included in the study. Intraoperative and ultrasound findings were compared. One hundred forty-two patients were included, 116 without and 26 with prior exploration. The sensitivity and positive predictive value of ultrasound were 86.9% and 89.1%, respectively. These data were not significantly different in patients without (88.2% and 90%) and in patients with (80% and 84.2%) prior thyroid or parathyroid surgery. The overall accuracy was 79% with a false-negative rate of 11.3%. Thyroid nodularity was significantly more common (81.8%) in patients who had a false-positive or false-negative finding on ultrasound than in the total population (61.3%). High-resolution ultrasound is an accurate method for localizing parathyroid adenomas even in patients who have previously undergone parathyroid exploration. However, the presence of thyroid nodules can interfere with its accuracy.

Impact of short-term intermittent intravenous dobutamine therapy on endothelial function in patients with severe chronic heart failure

Background Intermittent intravenous dobutamine therapy is used to treat patients with decompensated end-stage chronic heart failure (CHF), in whom the vascular endothelium is usually impaired. Although it has been suggested that modification or reversal of endothelial dysfunction may be of significant therapeutic benefit, the impact of short-term intermittent intravenous dobutamine therapy on flow-mediated dilation (FMD) in patients with severe decompensated end-stage chronic CHF has not been assessed. Methods We prospectively assessed the impact of intermittent intravenous low-dose dobutamine therapy on endothelium-dependent brachial artery FMD and endothelium-independent nitroglycerin (NTG)-mediated vasodilation using high resolution ultrasound scanning in 20 consecutive male patients with severe CHF and ischemic cardiomyopathy (New York Heart Association functional class IV), at baseline and after 4 months, and compared them to 20 age- and sex-matched control subjects. The cardiac index (CI), stroke index (SI), and systemic vascular resistance (SVR) were assessed non-invasively with a thoracic electrical bioimpedance device before and after intravenous dobutamine therapy. Results Intermittent intravenous dobutamine therapy resulted in significant improvement in post-intervention FMD compared with baseline (7.7% ± 2.4% vs 1.1% ± 2.6%; P = .001), a finding not evident in control subjects (1.3% ± 2.6% vs 1.2% ± 2.1%; P = .78). There was no significant effect of dobutamine treatment compared with control subjects on NTG-induced vasodilation (7.6% ± 5.5% vs 7.5% ± 8.8%, P = .979). Short-term dobutamine therapy also significantly improved SVR (1797 ± 926 dyne sec/cm 5 vs 2172 ± 1133 dyne sec/cm 5, P = .05), CI (2. 4± 0.6 L/min/m 2 vs 1.9 ± 0.6 L/min/m 2, P = .01), and SI (33.5 ± 11.7 mL/m 2 vs 27.2 ± 12.4 mL/m 2, P = .02). Conclusions Short-term intermittent intravenous low-dose dobutamine therapy significantly improved vascular endothelial function, perhaps demonstrating an additional mechanism for improved SVR, CI, and SI in patients with severe CHF.

Optimizing global risk evaluation in primary hypertension

To assess the impact and cost-effectiveness of microalbuminuria and cardiovascular ultrasonography in evaluating the risk profile in primary hypertension. Four hundred and five untreated patients with primary hypertension underwent a routine, traditional work-up plus evaluation of albuminuria and ultrasound (US) assessment of cardiac and vascular structures. Albuminuria was measured as the albumin to creatinine ratio in three non-consecutive first-morning urine samples. Left ventricular mass index was assessed by MB-mode echocardiography and carotid intima-media thickness by high-resolution US scan. The impact of these tests on patient risk classes, as indicated by European Society of Hypertension-European Society of Cardiology (ESH-ESC) guidelines, was assessed with respect to their cost and sensitivity. The prevalence of microalbuminuria, left ventricular hypertrophy and carotid intima-media thickening or carotid plaque was 13, 49 and 32%, respectively. The combined use of albuminuria, cardiac and vascular ultrasonography led to the detection of a significantly higher percentage of patients at high/very high risk. The three tests differ in sensitivity (albuminuria, 20%; echocardiography, 65%; and carotid ultrasound, 41%). The signs of target organ damage (TOD) only partly cluster within the same subgroup of patients and, thus, all three tests should be performed in order to maximize the sensitivity of the evaluation process. The diagnostic algorithm yielding the lowest cost per detected case of TOD is the search for microalbuminuria followed by cardiac and carotid ultrasound assessment. Ultrasonographic detection of TOD is a sensitive tool in the identification of high-risk patients, but should be preceded by a routine search for microalbuminuria in order to optimize the cost-effectiveness of the diagnostic work-up.

Effects of pravastatin on lipoproteins and endothelial function in patients receiving human immunodeficiency virus protease inhibitors

Background Although recommended as initial therapy for patients with dyslipidemia who are taking human immunodeficiency virus protease inhibitors (HIV PIs), the effects of pravastatin on lipoproteins and arterial reactivity have not been elucidated. The purpose of this study was to determine the effects of pravastatin on lipoprotein subfractions and endothelial function in patients with dyslipidemia who are receiving HIV PIs. Methods This was a placebo-controlled, double-blind, crossover study comparing pravastatin (40 mg) to placebo in 20 patients who were taking HIV PIs. Lipoprotein subfractions were measured with nuclear magnetic resonance spectroscopic analysis. Flow-mediated vasodilation (FMD) of the brachial artery was evaluated with high-resolution ultrasound scanning. Results At baseline, subjects had an increased concentration of low-density lipoprotein (LDL) particles (1756 ± 180 nmol/L), which tended to be small (19.9 ± 0.2 nm), a low concentration of large high-density lipoproteins (HDL; 0.94 ± 0.07 mmol/L), and an increased concentration of large very low-density lipoproteins (VLDL; 1.90 ± 0.58 mmol/L). FMD was impaired (4.5% ± 1.1%). Compared with placebo, pravastatin resulted in a 20.8% reduction in LDL particles ( P = .030), a 26.7% reduction in small LDL ( P = .100), and a 44.9% reduction in small VLDL ( P = .023). Total and non-HDL cholesterol levels decreased by 18.3% ( P <.001) and 21.7% ( P <.001), respectively. FMD tended to increase in patients receiving pravastatin (0.7% ± 0.6%); however, the difference between treatment phases was not statistically significant ( P = .080). Conclusions This is the first double-blind, placebo-controlled study of the effects of statin therapy on lipids, lipoprotein subfractions, and endothelial function in patients taking HIV PIs. Pravastatin reduced concentrations of atherogenic lipoproteins, particularly those most associated with future coronary events.

Perceived stress and cortisol levels predict speed of wound healing in healthy male adults

The main purpose of the present study was to investigate the association between perceived stress and impaired cutaneous wound healing in humans using a novel wound assessment technique, and taking into account putative mediating factors such as cortisol levels, health behaviours, and personality factors. The study made use of a prospective, within-subjects design in which 24 male non-smokers participated. Every subject received a standard 4mm-punch biopsy, and the healing progress was monitored via high-resolution ultrasound scanning. Participants completed questionnaires on perceived stress, health behaviours, and personality factors, and sampled saliva for cortisol assessment after awakening at 2 weeks prior, directly after, and 2 weeks after the biopsy. The overall results showed a significant negative correlation between speed of wound healing, and both Perceived Stress scale (PSS) scores (r=−.59; p<.01), and General Health Questionnaire (GHQ) scores (r=−.59; p<.01) at the time of the biopsy. The area under the morning cortisol response curve was negatively correlated with speed of wound healing (r=−.55; p<.05), indicating a clear elevation in the morning cortisol slope of those whose wounds were slowest to heal. A median split of the complete sample yielded that the ‘slow healing’ group showed higher stress levels (PSS t=3.93, p<.01, GHQ t=2.50, p<.05), lower trait optimism (t=3.25, p<.05), and higher cortisol levels to awakening (F=5.60, p<.05) compared with the ‘fast healing’ group. None of the health behaviours investigated (i.e. alcohol consumption, exercise, healthy eating, and sleep) were correlated with healing speed at any time point. Our data hint at a considerable influence of stress on wound healing, and suggests that elevated cortisol levels, rather than altered health behaviours, play a role in this effect.

Improvement of peripheral endothelial dysfunction by acute vitamin C application: different effects in patients with coronary artery disease, ischemic, and dilated cardiomyopathy

Background Endothelial dysfunction has been described in patients with coronary artery disease (CAD) or chronic heart failure (CHF). Vitamin C administration leads to an improvement of endothelial function by reducing elevated levels of reactive oxygen species. It remains unclear, however, whether the degree of endothelial dysfunction caused by oxidative stress differs between CAD and CHF because of ischemic (ICM) or dilated cardiomyopathy (DCM). Methods In patients with CAD (n = 9; left ventricular ejection fraction [LVEF], 64% ± 3%), ICM (n = 9; LVEF, 25% ± 4%), DCM (n = 9; LVEF, 25% ± 3%), and healthy subjects (HS; n = 5; LVEF, 66% ± 5%) a change in internal radial artery diameter in response to acetylcholine (Ach; 15 and 30 μg/min) was measured with high-resolution ultrasound scanning during a co-infusion of normal saline or vitamin C (25 mg/min). Results Ach-mediated vasodilation was blunted in patients with CHF (DCM, 90 ± 20 μm; ICM, 86 ± 20 μm) and patients with CAD (336 ± 20 μm) as compared with HS (496 ± 43 μm; P <.05 vs patients with DCM, ICM, CAD). Vitamin C co-infusion increased Ach-mediated vasodilation by 180 ± 35 μm (to 270 ± 30 μm) in DCM ( P <.05 vs CAD, HS) and by 294 ± 40 μm (to 380 ± 20 μm) in ICM ( P <.05 vs DCM, CAD, HS). In patients with CAD, vitamin C increased Ach-mediated vasodilation by 146 ± 35 μm to normal values, whereas vascular diameter remained unchanged in HS (14 ± 20 μm; P = not significant). Conclusions Acute vitamin C administration restored peripheral endothelial function in patients with CAD to normal values, whereas endothelial function remained attenuated in CHF, in particular in patients with DCM. These results suggest that in patients with CHF, factors other than oxidative stress (eg, cytokines) contribute to the pathologic endothelial function.

Orally and transdermally replaced estradiol improves endothelial function equally in middle-aged women after surgical menopause

Objective: Improvement in endothelial function may be an important mechanism by which estrogen replacement therapy protects postmenopausal women against coronary artery disease. We determined whether the vascular effects of estradiol depend on the route of administration. Study Design: Six weeks after surgically induced menopause, 43 healthy women were assigned randomly to 28 weeks of treatment by either orally or transdermally replaced estradiol. Endothelium-dependent and endothelium-independent dilation were calculated with the use of the diameters of the brachial artery that were measured at rest by high resolution ultrasound scanning after reactive hyperemia and after sublingual glyceryl trinitrate. Results: Endothelium-dependent dilation increased after oral estradiol replacement from 6% ± 3.9% to 13.2% ± 4.4% (P <.0001) and after transdermal estradiol replacement from 7% ± 4.9% to 14.9% ± 5.6%(P <.0001). Endothelium-independent dilation did not change significantly in either group. The improvements in endothelium-dependent dilation after estrogen substitution were independent of the changes in blood lipids and lipoproteins. Conclusion: Both oral and transdermal long-term replacement of estradiol lead to improved endothelial function in healthy middle-aged women after surgically induced menopause.

Porphyromonas gingivalis infection is associated with carotid atherosclerosis in non-obese Japanese type 2 diabetic patients

The aim of the present study was to investigate whether non-obese Japanese type 2 diabetic patients with porphyromonas gingivalis infection have atherosclerotic vascular diseases. A total of 134 non-obese Japanese type 2 diabetic patients (96 men and 38 women, aged 36 to 84 years, body mass index [BMI] 20.1 to 26.9 kg/m2) were studied. In conjunction with BMI, glycosylated hemoglobin (HbA1c), fasting glucose, and serum lipids (triglycerides, total cholesterol, high-density lipoprotein [HDL] cholesterol, low-density lipoprotein [LDL] cholesterol) were measured. LDL cholesterol was calculated using the Friedewald formula. Using high-resolution B-mode ultrasound scan, we measured intimal medial thickness (IMT) in plaque-free segments of bilateral common carotid arteries, and the mean of IMT in 2 vessels was used for the analysis. Furthermore, we calculated the degree of stenosis in plaque segments of bilateral common carotid arteries. The degree of carotid atherosclerosis was expressed as a percentage ratio between the area of plaque and that of the lumen using the formula (Lumen Area Residual − Lumen Area)/Lumem Area × 100. Both the areas were automatically measured by the system on a frozen transverse scanning plane at the site of maximal narrowing. When 2 or more plaques were present in the vessel, only that causing the greatest degree of stenosis was considered for analysis. Values represent mean±SEM unless otherwise stated. Immunoglobulin G (IgG) titer against porphyromonas gingivalis was 245 ± 65 (mean ± 2 SD) in nondiabetic healthy subjects. In contrast, there was a wide variation in IgG titer against porphyromonas gingivalis in type 2 diabetic patients studied (range, 16 to 26,800). Thus, we classified our type 2 diabetic patients into 2 subpopulations according to the value of mean ± 2 SD (= 310) of nondiabetic healthy subjects: one with high IgG titer against porphyromonas gingivalis (>310) (1,422 ± 408) and the other with normal IgG titer against porphyromonas gingivalis (<310) (152 ± 10, P =.002). The populations did not differ with respect to age, sex, BMI, fasting glucose, HbA1c, serum triglycerides, total, HDL, and LDL cholesterol levels. Although the mean IMT in plaque-free segments was not different between the 2 groups (0.73 ±0.03 v 0.68 ± 0.02 mm, P =.098), the degree of stenosis in plaque segments was significantly higher in the high IgG titer group (12.0% ± 2.2%) than in normal one (5.5% ± 1.4%, P =.009). From these results, it can be concluded that porphyromonas gingivalis infection, although still a subclinical infection, is associated with atherosclerotic vascular disease in non-obese Japanese type 2 diabetic patients. Copyright 2003, Elsevier Science (USA). All rights reserved.

Radical-trapping activity, blood pressure, and carotid enlargement in women.

The aim of this study was to evaluate the influence of traditional and nontraditional (oxidation markers) cardiovascular risk factors on the degree of adaptive response of the carotid wall to atherosclerotic disease, a process known as arterial enlargement. Five thousand sixty-two clinically healthy, middle-aged women living in the area of Naples participated in the "Progetto Atena" study; 310 of these women (potentially at higher atherosclerotic risk) underwent a high-resolution ultrasound scan of the carotid arteries. In addition to routine biochemical tests, these women had the determination of serum IgG antibody titer against oxidized LDL and measurement of thiobarbituric acid reactive substances and total radical-trapping activity potential of plasma. Age, systolic blood pressure, body mass index, and radical-trapping activity were all positively correlated with external and internal common carotid diameters, whereas triglycerides (positively) and HDL cholesterol (inversely) were related only to external diameter. After controlling for traditional cardiovascular risk factors, associations still persisted for age, systolic blood pressure, and plasma radical-trapping activity with external carotid diameters. However, in the quartile of women with highest total cholesterol (>7.38 mmol/L), the slope of the regression line between systolic blood pressure and external diameter was significantly flatter than in the three other quartiles (test for difference, P=0.014). Outward carotid enlargement is related to traditional and nontraditional risk factors and comes even before plaque development. Women with poor resistance to oxidative stress potentially have a difficulty to remodel their arteries in response to atherosclerotic stimuli.

Carotid intima media thickness and left ventricular changes in children with end-stage renal disease

To investigate the association between blood pressure and carotid intima-media thickness (IMT) in healthy adolescents.Study participants included 285 first-year high school students (mean age, 15.2 years) at a rural high school in Korea. Systolic and diastolic blood pressure (SBP and DBP) were measured with an oscillometric automated sphygmomanometer. The carotid arteries were evaluated with high-resolution B-mode ultrasound scanning. IMT value was determined with the average of the maximal IMT at each common carotid artery. Increased IMT was defined as sex-specific top quartile. The odds ratio (OR) for increased IMT per 1 SD increase of SBP and DBP was estimated after adjusting for age, sex, body mass index, waist circumference, fasting glucose level, and total/high-density lipoprotein cholesterol ratio.Adjusted OR for increased IMT was 1.70 (P = .003) per 12.4 mm Hg SBP and 1.25 (P = .125) per 7.0 mm Hg DBP. When the analyses were performed by sex, increased IMT was associated with both SBP (OR, 2.67; P = .003) and DBP (OR, 1.68; P = .019) in girls, but it was not associated with either SBP (OR, 1.46; P = .093) or DBP (OR, 0.99; P = .972) in boys.These results suggest that higher blood pressure level may be associated with increased carotid IMT in apparently healthy adolescents.

5,10-methylenetetrahydrofolate reductase polymorphism and early organ damage in primary hypertension

Hyperhomocyst(e)inemia is a known risk factor for the development of atherosclerotic vascular damage. Plasma homocyst(e)ine levels are influenced by nutritional and hereditary factors. A point mutation (cytosine to thymidine substitution; C677T) in the gene encoding 5,10-methylenetetrahydrofolate reductase (MTHFR) makes the enzyme thermolabile and has been associated with elevated homocyst(e)ine levels in homozygous carriers (TT genotypes). We evaluated the relationship between the T allele encoding for the thermolabile variant of MTHFR and several biochemical risk factors and early signs of hypertensive and atherosclerotic organ damage in 206 untreated patients with primary hypertension. The MTHFR genotype was evaluated by polymerase chain reaction. Albuminuria was measured as albumin-to-creatinine ratio in three nonconsecutive first morning urine samples (negative urine culture). Persistent Mi (Alb+) was defined as an average albumin-to-creatinine ratio between 2.38 and 19 (men) and 2.96 and 20 (women). Left ventricular (LV) mass index (LVMI) was assessed by M-B mode echocardiography (LV hypertrophy, LVH = LVMI ≥125g/m 2), carotid geometry by high-resolution ultrasound scan, and retinal vascular changes by direct ophthalmoscopy (Keith-Wagener classification). The prevalence of Mi, LVH, and retinopathy was 14%, 45%, and 42%, respectively. The prevalence of carotid plaque was 25%. Allele frequencies for C (wild-type allele) and T allele (mutant allele) were 56% and 44%, respectively. Genotype frequencies were CC 29%, CT 54%, TT 17% according to Hardy Weinberg equilibrium. There were no differences as for age, sex, body mass index, blood pressure levels, lipid profile, smoking habits, and alcohol intake, and LVMI and urinary albumin excretion on the basis of MTHFR genotype. Patients with TT polymorphism showed a higher prevalence of retinal vascular changes (TT, 61% v CT + CC, 38%; P < .02) and carotid plaque (TT, 42% v CT + CC, 21%; P < .05) compared to patients with CC and CT polymorphism. Moreover, patients with T allele showed increased carotid artery size as demonstrated by intima plus media thickness (TT, 0.79 ± 0.05 mm v CT + CC, 0.67 ± 0.02 mm; P < .02), relative wall thickness (TT, 0.23 ± 0.01 mm v CT + CC, 0.20 ± 0.005 mm; P < .02), and surface area (TT, 19 ± 1.9 mm 2 v CT + CC, 15 ± 0.55 mm 2; P < .05). Multiple linear regression analysis demonstrated that MTHFR genotype and systolic blood pressure independently influence intima-media thickness and together account for about 11% of its variations (r 2 = 0.11, F = 9.7, dF = 1–205, P < .0001). Homozygosity for the T allele of the MTHFR gene is an independent risk factor for the development of early atherosclerotic organ damage in hypertensive patients.

Increased renal resistive index in patients with essential hypertension: a marker of target organ damage.

Increased renal resistance detected by ultrasound (US) Doppler has been reported in severe essential hypertension (EH) and recently was shown to correlate with the degree of renal impairment in hypertensive patients with chronic renal failure. However, the pathophysiological significance of this finding is still controversial. In a group of 211 untreated patients with EH, we evaluated renal resistive index (RI) by US Doppler of interlobar arteries and early signs of target organ damage (TOD). Albuminuria was measured as the albumin to creatinine ratio (ACR) in three non-consecutive first morning urine samples. Left ventricular mass was evaluated by M-B mode echocardiography, and carotid wall thickness (IMT) by high resolution US scan. RI was positively correlated with age (r=0.25, P=0.003) and systolic blood pressure (SBP) (r=0.2, P=0.02) and with signs of early TOD, namely ACR (r=0.22, P=0.01) and IMT (r=0.17, P<0.05), and inversely correlated with renal volume (r=-0.22, P=0.01) and diastolic blood pressure (r=-0.23, P=0.006). Multiple linear regression analysis demonstrated that age, gender, ACR and SBP independently influence RI and together account for approximately 20% of its variations (F=8.153, P<0.0001). When clinical data were analysed according to the degree of RI, the patients in the top quartile were found to be older (P<0.05) and with higher SBP (P<0.05) as well as early signs of TOD, namely increased ACR (P<0.002) and IMT (P<0.005 by ANOVA), despite similar body mass index, uric acid, fasting blood glucose, lipid profile and duration of hypertension. Furthermore, patients with higher RI showed a significantly higher prevalence of microalbuminuria (13 vs 12 vs 3 vs 33% chi2=11.72, P=0.008) and left ventricular hypertrophy (40 vs 43 vs 32 vs 60%, chi2=9.25, P<0.05). Increased RI is associated with early signs of TOD in EH and could be a marker of intrarenal atherosclerosis.

Efficacy of Topical 0.05% Retinaldehyde in Skin Aging by Ultrasound and Rheological Techniques

Background: The natural precursor of retinoic acid, i.e. retinaldehyde, has been proven to exert retinoid activities. Aim and Methods: The aim of this prospective instrument study was to determine the effect of topical retinaldehyde 0.05% on the physical properties of aging skin. This was performed using two devices, namely a high-resolution (70–80 µm) ultrasound scanner, which visualizes the thickness of both the epidermis and the dermis, and an echorheometer, which assesses the stiffness and elasticity of the skin by suction. In a 1-year study, 21 patients applied retinaldehyde cream 0.05% on the face, while another group of 19 volunteers were only treated with an emollient (control group). Epidermal and dermal thicknesses were measured on the forehead and temple, and stiffness and elasticity were measured on the forehead only. All the instrumental parameters were assessed at baseline and at the end of treatment. Results: Compared to the control group, retinaldehyde treatment induced a significant increase in epidermal thickness of the temple, as well as in cutaneous elasticity (p < 0.01). Similarly, retinaldehyde treatment tended to increase dermal thickness and reduce cutaneous stiffness, but no statistical difference could be observed between the two groups. Conclusion: Taken together, the results further suggest that retinaldehyde has counteracting effects on skin aging

Endothelium-dependent vasodilatation is impaired in both microcirculation and macrocirculation during acute hyperglycemia

Purpose: Endothelial dysfunction is associated with atheromatosis and is a common finding with diabetes. We have studied the effects of acute hyperglycemia on the endothelium-dependent vasodilatation of both the microcirculation and the macrocirculation of healthy subjects. Because of the presence of endothelial dysfunction with diabetes, we hypothesize that acute hyperglycemia causes impaired endothelial-dependent responses. Methods: Twenty healthy subjects (15 men, 5 women) with a mean age of 32.3 years (range, 23 to 49 years) were examined during fasting conditions and at 1 hour after the ingestion of 75 g of glucose. The endothelium-dependent vasodilatation of the brachial artery, a conduit vessel, was evaluated with high-resolution ultrasound scan to measure the changes in the vessel diameter induced with reactive hyperemia. In the microcirculation, the endothelial function was assessed by measuring the changes in the erythrocyte flux after the acetylcholine iontophoresis. Results: The brachial artery endothelium-dependent dilatation was greater during fasting as compared with the response after the glucose load was administered (11.7% [8.3 to 14.3] vs 4.2% [1.5 to 9.6]; P < .001; median, first, and third quartile). Both peak and average blood flow velocities during the hyperemic response were higher after the administration of the glucose load as compared with the fasting period ( P < .05), but no changes were found in the blood flow volume. During fasting, microcirculatory endothelial-dependent vasodilatation was also significantly greater than the response after the administration of the glucose load (1293% [591 to 1856] vs 863% [385 to 1180]; P < .01). Conclusions: In healthy subjects, the ingestion of a glucose load impairs the endothelial-dependent vasodilation in both the microcirculation and the macrocirculation. Because impairment of endothelial responses is associated with the early changes of atherosclerosis, it is possible that prolonged hyperglycemia and endothelial dysfunction may lead to the early and accelerated atherosclerosis of diabetes. Further studies are necessary to examine the long-term effects of hyperglycemia. (J Vasc Surg 1998;28:687-94.)

Pro-inflammatory cytokines and endothelium-dependent vasodilation in the forearm. Serial assessment in patients with congestive heart failure.

In patients with heart failure endothelium-dependent vasodilation of the forearm conduit vessels is impaired possibly because of elevated plasma levels of pro-inflammatory cytokines. The effect of elevated plasma cytokines on endothelium-dependent vasodilation of forearm conduit vessels was therefore serially investigated in 16 patients with congestive heart failure during an episode of acute failure and at the time of recompensation. Pro-inflammatory cytokine levels and hyperaemic brachial artery diameters were obtained shortly after admission for an episode of acute heart failure and 11 +/- 3 days later at the time of recompensation, which was obtained using diuretic therapy without changing other cardiovascular medications. Serum concentrations (Mean +/- SD) of tumour necrosis factor alpha (TNF-alpha) (decompensation vs recompensation: 25 +/- 23 pg.ml-1 vs 26 +/- 17 pg.ml-1) and interleukine 6 (IL-6) (decompensation vs recompensation: 27 +/- 24 pg.ml-1 vs 20 +/- 18 pg.ml-1), determined in venous blood using immunoradiometric assays were elevated but remained unaltered following recompensation. Brachial artery diameter, derived from high-resolution ultrasound scans at rest and during reactive hyperaemia, 90 s after forearm cuff deflation, increased significantly during reactive hyperaemia at the time of admission (3.4 +/- 0.7 mm vs 4.0 +/- 0.5 mm; P = 0.014) and following recompensation (3.4 +/- 0.5 mm vs 3.8 +/- 0.2 mm; P = 0.032). The brachial artery diameter during recompensation expressed as a percentage of the baseline value was similar at both intervals (decompensation vs recompensation: 117 +/- 14% vs 116 +/- 10%; P = ns). At the time of decompensation, the correlation between TNF-alpha and the percentage change in brachial artery diameter following reactive hyperaemia was absent (r = 0.098; P = 0.719). The same correlation became significant at the time of recompensation (r = 0.750; P = 0.001). In patients with congestive heart failure, plasma levels of pro-inflammatory cytokines correlate with endothelium-dependent vasodilation of the brachial artery following recompensation, but not during an acute episode of heart failure.

Microalbuminuria Is an Early Marker of Target Organ Damage in Essential Hypertension

Microal buminuria has been associated with a cluster of metabolic and nonmetabolic risk factors, suggesting that it might indicate the presence of generalized microvascular damage in patients with essential hypertension. To explore whether microalbuminuria is associated with early target organ damage, two groups of essential hypertensive patients, with (n = 17) (HtAlb+) and without (n = 16) (HtAlb−) microalbuminuria, and a control group (C) of healthy normotensive subjects (n = 20) were studied. The study groups, selected among participants of a large epidemiologic trial, were carefully matched for several potentially confounding variables such as gender, age, duration of hypertension, and body mass index. Albumin excretion rate was evaluated by radioimmunoassay in three nonconsecutive timed overnight collections after 3 weeks of pharmacologic wash-out. Left ventricular mass was assessed by M-B-mode echocardiography, carotid wall thickness by a high resolution ultrasound scan, and renal vascular impedance by Doppler scan. Office as well as 24-h ambulatory pressure monitoring (Takeda TM-2420) were also evaluated. There was no difference between the two hypertensive groups for office and 24-h blood pressure levels except for a lower daytime/nighttime systolic blood pressure ratio in the group with microalbuminuria. Microalbuminuric patients showed signs of early organ damage as compared to normoalbuminuric patients and normal subjects, namely greater left ventricular mass indices (LVMI 167 ± 7 g/m 2 in HtAlb+; 139 ± 9 g/m 2 in HtAlb−; 118 ± 5 g/m 2 in C, P < .001) and increased wall thickness of common carotid arteries (intima plus media thickness 12.5 ± 0.2 mm in HtAlb+; 11.7 ± 0.3 mm in HtAlb−; 11.2 ± 0.2 mm in C, P < .001) as well as higher intrarenal vascular resistance (mean resistive index 0.62 ± 0.01 in HtAlb+; 0.59 ± 0.01 in HtAlb−; 0.59 ± 0.01 in C, P < .05). In conclusion, microalbuminuria is an early marker of diffuse target organ damage in essential hypertension and therefore can be useful to identify patients for whom more aggressive preventive strategies or additional treatment measures are advisable.

Sonographic evaluation of intervillous flow in early pregnancy: use of echo-enhancement agents.

The uteroplacental circulation of the cynomolgus monkey was examined in early pregnancy using a high-resolution ultrasound scanner. Intravenous injection of an echo-contrast agent, Albunex (sonicated albumin), was used to enhance the color Doppler images obtained. The flow of blood into and out of the intervillous compartment was readily assessed and quantified using pulsed and color Doppler. Flow within the intracotyledonary space was pulsatile and indicative of a low-resistance system. Flow within the decidual veins was non-pulsatile. The use of echo-contrast agents may assist in the determination of intervillous flow in human pregnancy at a correspondingly early stage.

Early antenatal ultrasound diagnosis of fetal intracranial teratoma.

The commonest fetal intracranial tumour is a teratoma. The prognosis is poor with death usually occurring shortly after birth. Modern high resolution ultrasound scanners facilitate examination of the cranial contents, allowing earlier diagnosis. We report a case where an intracranial teratoma was identified at 21 weeks gestation, the earliest gestational age that this has been reported. The ultrasound appearances are discussed.

Determination of Deltoid Fat Pad Thickness

To measure deltoid fat pad thickness and determine the optimal needle length for deltoid intramuscular immunization in healthy adults. Prospective study of 220 healthy health care workers (126 women, 94 men) at the Mayo Medical Center, Rochester, Minn. Deltoid fat pad thickness determined by high-resolution ultrasound scanning, weight, height, and mid-deltoid arm circumference. We found a highly significant difference between women and men in deltoid fat pad thickness, with women having a thicker deltoid fat pad (11.7 vs 8.3 mm; P<.001). Women had a greater deltoid skin-fold thickness than men (34.7 vs 17.2 mm, P<.001) and an equal body mass index. According to the ultrasound findings, a standard 16-mm (5/8-in) needle would not have reached 5 mm into muscle in 17% (16/94) of men and 48.4% (61/126) of women in this study. Among healthy adults of the age range we studied, the following needle lengths appear to be appropriate for true deltoid intramuscular immunization: For men across the weight ranges we studied (59-118 kg), use of a 25-mm (1-in) needle would result in at least 5 mm of muscle penetration in all subjects. For women who weighed less than 60 kg, a 16-mm (5/8-in) needle would be sufficient to achieve muscle penetration of 5 mm. For women between 60 and 90 kg, a 25-mm (1-in) needle would be sufficient, and women greater than 90 kg would require a 38-mm (1.5-in) needle to ensure intramuscular administration.

Determination of intervillous flow in early pregnancy

The process of placentation in the macaque has been extensively studied and found to resemble closely that observed in the human. In this model, histopathologically, intervillous flow is anticipated from week 3 post-conception. We set out to document the nature and onset of intervillous flow in the macaque in vivo using colour Doppler imaging (CDI), colour Doppler energy (CDE) and pulsed-wave Doppler (PWD). Pregnant females were assessed between 15-50 days gestation (term = 165 days) with an Acuson 128/XP10 high-resolution ultrasound scanner, using a 7-MHz linear array probe. The placenta, subjacent decidua and myometrium were assessed using CDI and CDE. Specific regions of flow were interrogated using PWD; the resulting flow velocity waveforms were stored and quantified using conventional Doppler indices. B-mode sonography was able to demonstrate the well-defined placental-decidual interface observed in this species; CDI and CDE clearly visualized the uteroplacental vasculature. Spiral arteries were followed to their point of discharge into the intervillous space, and PWD at these sites obtained a characteristic flow velocity waveform. The indices obtained confirmed a flow of low resistance and pulsatility throughout the gestation studied. Flow within the intervillous space was noted from day 20 of gestation.