Association between fasting blood glucose and intracranial cerebral artery stenosis: a secondary analysis based on a retrospective cross-sectional study in Korean adults

AIMS

Diabetes mellitus (DM) is one of the main risk factors for intracranial cerebral artery stenosis (ICAS), and fasting blood glucose (FBG) might be an effective predictor of ICAS. However, there are a few studies revealing the relationship between FBG and ICAS. We aim to identify the association between FBG and ICAS in Koreans.

METHODS

This was a secondary study based on a cross-sectional study. A total of 1011 Korean individuals who were asymptomatic but with high cerebrovascular risk underwent an examination in a Korean medical centre from March 2008 to December 2014. The main measure was FBG, while the main outcome was ICAS. Multivariate logistic regression analyses of FBG in the presence of ICAS were performed to examine the potential association. The author used the data provided by the paper "Association between Serum Alkaline Phosphatase Level and Cerebral Small Vessel Disease" for secondary analysis.

RESULTS

The average age of the participants was 64.2 ± 9.1 years old, and approximately 35% of them were males. There were 24 participants suffering from ICAS in the first FBG tertile (< 5.4 mmol/L), while there were 26 in the second tertile (5.4-7.1 mmol/L) and 50 in the third tertile (≥ 7.1 mmol/L). The non-adjusted relationship between FBG and ICAS was positive. After controlling potential confounders, the association of FPG with ICAS remained positive, as well as in subgroups analysis, such as age, sex, hypertension, diabetes mellitus, hyperlipidaemia and COAD. The association remained unchanged after adjusted sex, age, hypertension, DM, uric acid, hyperlipidaemia, and CAOD (OR = 1.08, 95% CI = 1.02-1.15). The analyses also showed that the positive association was statistically significant (P < 0.05) among individuals without diabetes.

CONCLUSIONS

This study showed a positive relationship between FBG and ICAS, which suggests that clinicians may need to be simultaneously concerned about FBG and ICAS.

Comparative Study of Chronic Postischemic Pain Models in Mice: O-Ring Versus Tie Method

BACKGROUND

The success rate for the production of animal models of chronic postischemia pain (CPIP) using an O-ring has yet to be improved in the study of complex regional pain syndrome-type I (CRPS-I), and producing a CPIP model is challenging, especially for mice.

OBJECTIVES

We devised a new CPIP model with a higher success rate that induces ischemia for 3 hours by tying the hind limbs of mice with a rubber band, followed by reperfusion.

STUDY DESIGN

A randomized, controlled animal trial.

METHODS

Twenty-two male C57BL/6 mice were divided into a sham (n = 6), a ring (n = 8), and a tie group (n = 8). Anesthesia was induced using isoflurane. A precut O-ring was mounted on the upper left ankle in the sham group. A tight-fitting O-ring and a push-pull gauge manometer were mounted at the same location in the ring and tie groups, respectively. Reperfusion was induced 3 hours later. The thickness and circumference of the hind paws were measured before ischemia induction. Measurements were repeated 10 days after reperfusion. Mechanical allodynia was measured with a von Frey filament until 12 weeks after reperfusion.

RESULTS

The new tie model required 5 additional days until the onset of allodynia compared with the existing CPIP O-ring model. However, the successful induction rate of CPIP was higher in the tie group than in the ring group, and allodynia was maintained for over 30 days in the tie group. The ring and tie groups exhibited significantly high levels of tumor necrosis factor-alpha than those in the sham group.

LIMITATIONS

First, we did not evaluate hyperalgesia, cold or heat allodynia. Second, we did not measure blood levels of inflammatory or antiinflammatory cytokines, and research on oxidative stress biomarkers such as isoprostane, 8-hydroxy-2'-deoxyguanosine (a marker of DNA oxidative damage), and malondialdehyde was not performed.

CONCLUSIONS

The new CPIP tie model has a higher rate of successful induction than existing O-ring models for mice, with longer duration of mechanical allodynia. The model may reduce the number of animals sacrificed in CRPS-I research and could be useful for studying long-term effects of drugs.

KEY WORDS

CPIP, mouse, O-ring, rubber band, reperfusion, allodynia, hyperalgesia.

Circulating irisin levels are lower in patients with either stable coronary artery disease (CAD) or myocardial infarction (MI) versus healthy controls, whereas follistatin and activin A levels are higher and can discriminate MI from CAD with similar to CK-MB accuracy

BACKGROUND

Several myokines are produced by cardiac muscle. We investigated changes in myokine levels at the time of acute myocardial infarction (MI) and following reperfusion in relation to controls.

METHODS

Patients with MI (MI Group, n=31) treated with percutaneous coronary intervention (PCI) were compared to patients with stable coronary artery disease (CAD) subjected to scheduled PCI (CAD Group, n=40) and controls with symptoms mimicking CAD without stenosis in angiography (Control Group, n=43). The number and degree of stenosis were recorded. Irisin, follistatin, follistatin-like 3, activin A and B, ALT, AST, CK and CK-MB were measured at baseline and 6 or 24h after the intervention.

RESULTS

MI and CAD patients had lower irisin than controls (p<0.001). MI patients had higher follistatin, activin A, CK, CK-MB and AST than CAD patients and controls (all p≤0.001). None of the myokines changed following reperfusion. Circulating irisin was associated with the degree of stenosis in all patients (p=0.05). Irisin was not inferior to CK-MB in predicting MI while folistatin and activin A could discriminate MI from CAD patients with similar to CK-MB accuracy. None of these myokines was altered following PCI in contrast to CK-MB.

CONCLUSIONS

Irisin levels are lower in MI and CAD implying that their production may depend on myocadial blood supply. Follistatin and activin A are higher in MI than in CAD suggesting increased release due to myocardial necrosis. They can predict MI with accuracy similar to CK-MB and their role in the diagnosis of MI remains to be confirmed by prospective large clinical studies.

Predictive factors and clinical practice profile for strictures post-necrotising enterocolitis

Intestinal stricture is a severe and common complication of necrotizing enterocolitis (NEC), causing severe and prolonged morbidity. Our goal was to investigate the clinical predictors for strictures developing after NEC and evaluate the management outcome of the post-NEC strictures to better orient their medicosurgical care.A total of 188 patients diagnosed with NEC with identical treatment protocols throughout the period under study were retrospectively reviewed from 4 academic neonatal centers between from January 1, 2011, and October 31, 2016. Clinical predictive factors and clinical outcomes, including demographic information, clinical management, laboratory data, histopathology of resected bowel segment, and discharge summaries, were evaluated on the basis of with post-NEC strictures or not.Of the involved variables examined, the late-onset NEC [risk ratio (RR), 0.56; 95% confidence interval (95% CI), 0.41-0.92; P < 0.001], cesarean delivery (RR, 1.42; 95% CI, 0.98-2.29; P = 0.026), and first procalcitonin (PCT) (onset of symptoms) (RR, 1.82; 95% CI, 0.98-3.15; P = 0.009) were the independent predictive factors for the post-NEC strictures. C-reactive protein (CRP), white blood cell (WBC), and plateletcrit levels were markedly higher on infants with stricture and elevated levels were maintained until the stricture was healed. Infants with intestinal stricture had significantly longer times to beginning enteral feeds (23.9 ± 12.1), than infants without intestinal stricture (18.6 ± 8.8) (P = 0.023). The median age at discharge was also significantly higher in the group with stricture (P = 0.014).This retrospective and multicenter study demonstrates that the early-onset NEC and cesarean delivery conferred protection over the post-NEC stricture. Infants with post-NEC stricture need prolonged hospitalization.

Carcinoembryonic Antigen Level in Primary Sclerosing Cholangitis Is Not Influenced by Dominant Strictures or Bacterial Cholangitis

BACKGROUND

Carcinoembryonic antigen (CEA) can be used to screen for biliary tract cancer in patients with primary sclerosing cholangitis (PSC).

AIM

To study the influence of benign dominant strictures (DS), superimposed bacterial cholangitis (SBC), smoking status, and inflammatory bowel disease on CEA serum levels.

METHODS

A retrospective analysis of CEA values in cancer-free PSC patients was performed. We included the maximal CEA value obtained during follow-up and information on the presence of DS and SBC at that time, and we analyzed the CEA values in the presence and absence of DS and SBC. Results are reported as medians with the interquartile range (IQR).

RESULTS

The median maximal CEA level, which was 1.8 ng/mL (IQR 1.2-2.9) in the final 270 PSC patients included in the study, was not influenced by the presence of either DS or SBC (P = 0.320). Moreover, in 49 patients, the first CEA value available at the time of DS (1.5 ng/mL; IQR 1.2-2.1) and that at a time without DS (1.6 ng/mL; IQR 1.1-2.3) did not differ significantly (P = 0.397). Lastly, in 24 patients, the median CEA values at a time without SBC (1.8 ng/mL; IQR 1.2-2.5) and at the time of SBC (1.8 ng/mL; IQR 1.0-3.0) were comparable (P = 0.305). Smoking did not influence CEA-based cancer screening.

CONCLUSIONS

Serum CEA level is not influenced by the presence of DS or SBC and might therefore serve as a favorable parameter for improving cancer screening in PSC patients.

Cutting balloon treatment of anastomotic biliary stenosis after liver transplantation: Report of two cases

Biliary stenosis is a common complication after liver transplantation, and has an incidence rate ranging from 4.7% to 12.5% based on our previous study. Three types of biliary stenosis (anastomotic stenosis, non-anastomotic peripheral stenosis and non-anastomotic central hilar stenosis) have been identified. We report the outcome of two patients with anastomotic stricture after liver transplantation who underwent successful cutting balloon treatment. Case 1 was a 40-year-old male transplanted due to subacute fulminant hepatitis C. Case 2 was a 57-year-old male transplanted due to hepatitis B virus-related end-stage cirrhosis associated with hepatocellular carcinoma. Both patients had similar clinical scenarios: refractory anastomotic stenosis after orthotopic liver transplantation and failure of balloon dilation of the common bile duct to alleviate biliary stricture.

Monocyte Chemoattractant Protein-1 Levels and Postangioplasty Restenosis of Arteriovenous Fistulas

BACKGROUND AND OBJECTIVES

Inflammation is relevant in restenosis of atherosclerotic vascular diseases, but its role in dialysis arteriovenous fistula remains unknown. In animal studies, upregulation of monocyte chemoattractant protein-1 has been shown in venous segments of arteriovenous fistula. We, therefore, aimed to investigate serial changes in circulating monocyte chemoattractant protein-1 after percutaneous transluminal angioplasty of dialysis arteriovenous fistulas and its relation to restenosis.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Fifty-nine patients with dysfunctional arteriovenous fistulas that were referred for percutaneous transluminal angioplasty were enrolled prospectively between January of 2010 and July of 2012. Three of them were excluded due to percutaneous transluminal angioplasty failure or acute infection. Blood was sampled from arteriovenous fistulas at baseline, 2 days, 2 weeks, and 3 months after percutaneous transluminal angioplasty. Clinical follow-up was continued monthly for 3 months. Angiographic follow-up was arranged at the end of 3 months. Seventeen patients without significant stenosis were enrolled as the control group.

RESULTS

Fifty-six patients completed clinical follow-up. Significant increases in monocyte chemoattractant protein-1 were observed at 2 days and 2 weeks (both P<0.001) after percutaneous transluminal angioplasty. Twenty-three (41%) patients had symptomatic restenosis. The restenosis group had a higher percentage change in monocyte chemoattractant protein-1 levels at 2 days (median =47%; interquartile range, 27%-65% versus median =17%; interquartile range, 10%-25%; P<0.001) after percutaneous transluminal angioplasty compared with the patent group. Fifty-two patients completed angiographic follow-up. A positive correlation between relative luminal loss and monocyte chemoattractant protein-1 increase at 2 days after percutaneous transluminal angioplasty was found (r=0.53; P<0.001). In multivariate analysis, postangioplasty monocyte chemoattractant protein-1 increase at 2 days was an independent predictor of restenosis. Using receiver operator characteristic analysis, >25% postangioplasty increase of monocyte chemoattractant protein-1 was significantly associated with restenosis after percutaneous transluminal angioplasty (hazard ratio, 5.36; 95% confidence interval, 1.81 to 15.8).

CONCLUSIONS

Circulating monocyte chemoattractant protein-1 levels were elevated 2 days and 2 weeks after percutaneous transluminal angioplasty. Early postangioplasty increase of monocyte chemoattractant protein-1 level was associated with restenosis of arteriovenous fistulas.

Measurement of residual platelet thrombogenicity under arterial shear conditions in cerebrovascular disease patients receiving antiplatelet therapy

Essentials A consensus methodology for assessing the effects of antiplatelet agents has not been established. Measuring platelet thrombus formation (PTF) for evaluating antiplatelet effects was assessed. PTF differentially reflected antiplatelet effects compared to other tests. PTF may be associated with the severity of carotid or intracranial arterial stenosis. Click to hear a presentation on platelet function testing in the clinic by Gresele and colleagues

SUMMARY

Background A consensus methodology for assessing the effects of antiplatelet agents has not been established. Objective We investigated the usefulness of directly measuring platelet thrombus formation (PTF) using a microchip-based flow chamber system for evaluating antiplatelet therapy. Patients/Methods Platelet thrombus formation in the whole blood of 94 patients with ischemic cerebrovascular disease treated with clopidogrel and/or aspirin was measured in a flow chamber system at a shear rate of 1500 s(-1) and was compared with the results of assays for agonist-induced platelet aggregability, phosphorylation of vasodilator-stimulated phosphoprotein, platelet p-selectin expression (PS), and platelet-monocyte complexes. Results In all patients tested, area under the flow pressure curve (AUC10), which represents platelet thrombogenicity, showed weak correlation with platelet aggregation induced by either adenosine diphosphate or collagen. In addition, AUC10 was lower in patients treated with dual antiplatelet therapy (median 79.4) compared with patients treated with aspirin or clopidogrel alone (217.7 and 301.0, respectively), whereas the parameters evaluated by the other assays did not reflect the combined treatment efficacy. In clopidogrel monotherapy patients, AUC10 was associated with the severity of arterial stenosis (R(2) = 0.127, β = 1.25), and AUC10 and PS were higher in patients with severe carotid or intracranial arterial stenosis than in those with mild stenosis. Conclusions Platelet thrombus formation measurement using a flow-chamber system was useful for evaluating the efficacy of treatment with aspirin and clopidogrel, both alone and in combination. The present findings indicate that high residual platelet thrombogenicity in patients treated with clopidogrel may be associated with the severity of carotid or intracranial arterial stenosis.

Plasma Lipidomics as a Tool for Diagnosis of Extrahepatic Cholangiocarcinoma in Biliary Strictures: a Pilot Study

Biliary obstruction is a common clinical manifestation of various conditions, including extrahepatic cholangiocarcinoma. However, a screening test for diagnosis of extrahepatic cholangiocarcinoma in patients with biliary obstruction is not yet available. According to the rationale that the biliary system plays a major role in lipid metabolism, biliary obstruction may interfere with lipid profiles in the body. Therefore, plasma lipidomics may help indicate the presence or status of disease in biliary obstruction suspected extrahepatic cholangiocarcinoma. This study aimed to use plasma lipidomics for diagnosis of extrahepatic cholangiocarcinoma in patients with biliary obstruction. Plasma from healthy volunteers, patients with benign biliary obstruction extrahepatic cholangiocarcinoma, and other related cancers were used in this study. Plasma lipids were extracted and lipidomic analysis was performed using matrix-assisted laser desorption ionization time-of-flight mass spectrometry. Lipid profiles from extrahepatic cholangiocarcinoma patients showed significant differences from both normal and benign biliary obstruction conditions, with no distinction between the latter two. Relative intensity of the selected lipid mass was able to successfully differentiate all extrahepatic cholangiocarcinoma samples from patient samples taken from healthy volunteers, patients with benign biliary obstruction, and patients with other related cancers. In conclusion, lipidomics is a non-invasive method with high sensitivity and specificity for identification of extrahepatic cholangiocarcinoma in patients with biliary obstruction.

Asymptomatic intracranial arterial stenosis and metabolic syndrome: the APAC study

Purpose

The metabolic syndrome (MetS) is a major risk factor for cardiovascular diseases. We investigated potential associations between MetS and asymptomatic intracranial arterial stenosis (ICAS) in a general population.

Methods

The community-based “Asymptomatic Polyvascular Abnormalities in Community Study” examined asymptomatic polyvascular abnormalities in a Chinese population aged 40+ years without history of stroke and coronary heart disease. MetS was defined by the International Diabetes Federation criteria. Asymptomatic ICAS was diagnosed by transcranial color-coded Doppler sonography.

Results

Out of 5393 study participants, asymptomatic ICAS was detected in 713 (13.2%) participants, and MetS in 1323 (24.5%) individuals. Prevalence of asymptomatic ICAS increased significantly from 7.5% to 24.2% with increasing number of MetS components. After adjusting for age, gender, physical activity, body mass index, low-density lipoprotein cholesterol and high-sensitivity C-reactive protein, MetS was significantly associated with asymptomatic ICAS (OR: 1.50; 95%CI: 1.23,1.83). Compared with the subgroup without MetS, the ORs for asymptomatic ICAS increased (P<0.0001) for each of 5 components of MetS from 1.71 (95%CI: 1.27,2.30), to 2.20 (95%CI: 1.63,2.98), 2.79 (95CI: 2.01,3.88), 3.08 (95%CI: 2.11,4.51) and 4.27 (95%CI: 2.22,8.20).

Conclusions

In multivariate analysis, MetS was an independent and additional factor associated with asymptomatic ICAS. Study participants with 5 MetS components had a 4 times higher risk of asymptomatic ICAS than participants with no MetS component.

Circulating fibroblast growth factor 23 is associated with angiographic severity and extent of coronary artery disease

Objective

Fibroblast growth factor 23 (FGF23) is a circulating regulator of phosphate and vitamin D metabolism and is associated with coronary artery calcification, and has been implicated in the pathogenesis of cardiovascular disease. The aim of this study was to determine whether circulating FGF23 concentration is independently associated with the severity and extent of coronary artery disease in patients undergoing coronary angiography.

Method

A cross-sectional design was used to examine the relationship between serum FGF23 and the severity and extent of coronary artery stenosis in 2076 patients undergoing coronary angiography (1263 male and 813 female, mean aged 62.5 years). Subgroup analyses were performed to assess the associations between FGF23 and coronary arterial plaque characteristics evaluated by intravascular ultrasound and 12-month incidence of target vessel revascularization (TVR) and target lesion revascularization (TLR).

Findings

We found a stepwise increase of serum FGF23 concentrations in patients with mild, moderate, severe stenosis or with increased number of stenotic vessels compared with those without stenosis (P<0.001). Serum FGF23 concentration was positively correlated with stenosis scores as the global index of the severity and extent of coronary artery stenosis in both male and female (r = 0.315 and r = 0.291, P<0.001). In multiple regression analyses, serum FGF23 concentration was a significant determinant of the stenosis scores independent of other traditional risk factors (standardized β = 0.326, P<0.001). Furthermore, subgroup analyses found FGF23 was significantly associated with plaque and dense calcium volumes. Multiple logistic regression analyses showed that serum FGF23 levels were significantly independent predictors of TVR and TLR.

Conclusions

We report an independent association between circulating FGF23 concentration and the severity and extent of coronary artery stenosis in the coronary angiographic patients. Future studies are needed to elucidate the potential biological mechanisms and whether FGF23 is a modifiable cardiovascular risk factor.

Differentiation of pancreatobiliary cancer from benign biliary strictures using neutrophil gelatinase-associated lipocalin

Aim of the study was to investigate the value of serum and bile neutrophil gelatinase-associated lipocalin (NGAL) for distinguishing malignant strictures caused by cholangiocarcinoma (CCA) or pancreatic cancer from benign biliary strictures. The study was performed prospectively on patients admitted for endoscopic or radiologic biliary decompression. Forty patients with dilated biliary ducts, including 16 cases of CCA, 6 cases of pancreatic cancer, and 18 cases of benign biliary stricture were enrolled. Their sera and bile were collected to measure NGAL. Routine biochemistry including measurement of serum levels of carbohydrate antigens (CA) 19-9 and carcinoembryonic antigen (CEA) was also performed. The serum CA19-9, serum CEA, and bile NGAL levels were significantly increased in patients with malignant strictures as compared with patients with benign biliary diseases. Serum NGAL had no significant value for discriminating between malignant and benign biliary strictures. Bile NGAL levels had a receiver characteristic area under the curve of 0.74, sensitivity 77.3, and specificity 72.2% for discriminating between pancreatobiliary cancer and benign biliary diseases. Bile NGAL and serum CA19-9 were independent parameters and their combined use improved diagnostic accuracy (sensitivity 91%, negative predictive value 85.7%). We conclude that measurement of biliary, but not serum NGAL, may differentiate malignant pancreatobiliary from benign biliary strictures, serving as a complementary biomarker for serum CA19-9.

Hypertrophic pachymeningitis and tracheobronchial stenosis in IgG4-related disease: case presentation and literature review

Immunoglobulin G4 (IgG4)-related disease is a distinctive mass-forming disorder with frequent systemic involvement, most commonly in the pancreas, salivary glands and lacrimal glands. A few cases of dural involvement and one case of central airway stenosis have also been described. We report here a rare case of IgG4-related disease with intracranial hypertrophic pachymeningitis and irregular tracheobronchial stenosis. We review four previously reported cases of IgG4-related pachymeningitis. We currently lack international standards for the diagnosis of extrapancreatic IgG4-related disease. Based on the findings of the present case and those reported previously, we discuss the distinctive features of IgG4-related pachymeningitis.

Profiling circulating and urinary bile acids in patients with biliary obstruction before and after biliary stenting

Bile acids are considered as extremely toxic at the high concentrations reached during bile duct obstruction, but each acid displays variable cytotoxic properties. This study investigates how biliary obstruction and restoration of bile flow interferes with urinary and circulating levels of 17 common bile acids. Bile acids (conjugated and unconjugated) were quantified by liquid chromatography coupled with tandem mass spectrometry in serum and urine samples from 17 patients (8 men and 9 women) with biliary obstruction, before and after biliary stenting. Results were compared with serum concentrations measured in 40 age- and sex-paired control donors (20 men and 20 women). The total circulating bile acid concentration increases from 2.7 µM in control donors to 156.9 µM in untreated patients with biliary stenosis. Serum taurocholic and glycocholic acids exhibit 304- and 241-fold accumulations in patients with biliary obstruction compared to controls. The enrichment in chenodeoxycholic acid species reached a maximum of only 39-fold, while all secondary and 6α-hydroxylated species--except taurolithocholic acids--were either unchanged or significantly reduced. Stenting was efficient in restoring an almost normal circulating profile and in reducing urinary bile acids.

CONCLUSION

These results demonstrate that biliary obstruction affects differentially the circulating and/or urinary levels of the various bile acids. The observation that the most drastically affected acids correspond to the less toxic species supports the activation of self-protecting mechanisms aimed at limiting the inherent toxicity of bile acids in face of biliary obstruction.

Progressive peripheral arterial occlusive disease and other vascular events during nilotinib therapy in CML

The second generation BCR/ABL kinase inhibitor nilotinib is increasingly used for the treatment of imatinib-resistant chronic myeloid leukemia (CML). So far, nilotinib is considered a well-tolerated drug with little if any side effects, although an increase in the fasting glucose level has been reported. We examined a series of 24 consecutive CML patients treated with nilotinib in our center for the development of non-hematologic adverse events. Three of these 24 CML patients developed a rapidly progressive peripheral arterial occlusive disease (PAOD) during treatment with nilotinib. In all three cases, PAOD required repeated angioplasty and/or multiple surgeries within a few months. No PAOD was known before nilotinib-therapy in these patients, although all three had received imatinib. In two patients, pre-existing risk factors predisposing for PAOD were known, and one of them had developed diabetes mellitus during nilotinib. In the other 21 patients treated with nilotinib in our center, one less severe PAOD, one myocardial infarction, one spinal infarction, one subdural hematoma, and one sudden death of unknown etiology were recorded. In summary, treatment with nilotinib may be associated with an increased risk of vascular adverse events, including PAOD development. In a subgroup of patients, these events are severe or even life-threatening. Although the exact mechanisms remain unknown, we recommend screening for pre-existing PAOD and for vascular risk factors such as diabetes mellitus in all patients before starting nilotinib and in the follow up during nilotinib-therapy.

Venous blood gas and metabolite response to low-intensity muscle contractions with external limb compression

The effect of low-intensity resistance exercise with external limb compression (100 [EC100] and 160 [EC160] mm Hg) on limb blood flow and venous blood gas-metabolite response was investigated and compared with that of high-intensity resistance exercise (no external compression). Unilateral elbow flexion muscle contractions were performed at 20% (75 repetitions, 4 sets, 30-second rest intervals) and 70% of 1-repetition maximum (1-RM; 3 sets, each set was until failure, 3-minute rest intervals). Precontraction brachial arterial blood flow (Doppler ultrasound) was reduced with EC100 or EC160 (56% and 39% of baseline value, respectively) compared with no external compression (control). At 20% 1-RM, brachial arterial blood flow increased after contractions performed with EC160 (190%), but not with the others. Decreases in venous oxygen partial pressure (P(v)O(2)) and venous oxygen saturation (S(v)O(2)) were greater during EC100 and EC160 than control (mean [SE]: P(v)O(2), 28 [3] vs 26 [2] vs 33 [2] mm Hg; S(v)O(2), 41% [5%] vs 34% [4%] vs 52% [5%], respectively). Changes in venous pH (pH(v)), venous carbon dioxide partial pressure (P(v)CO(2)), and venous lactate concentration ([L(-)](v)) were greater with EC160 than EC100 and/or control (pH(v), 7.19 [0.01] vs 7.25 [0.01] vs 7.27 [0.02]; P(v)CO(2), 72 [3] vs 64 [2] vs 60 [3] mm Hg; [L(-)](v), 5.4 [0.6] vs 3.7 [0.4] vs 3.0 [0.4] mmol/L, respectively). Seventy percent 1-RM contractions resulted in greater changes in pH(v) (7.14 [0.02]), P(v)CO(2) (91 [5] mm Hg), and [L(-)](v) (7.0 [0.5] mmol/L) than EC100 and EC160, but P(v)O(2) (30 [4] mm Hg) and S(v)O(2) (40% [3%]) were similar. In conclusion, changes in pH(v), P(v)CO(2), and [L(-)](v), but not in P(v)O(2) and S(v)O(2), are sensitive to changes in relative, "internal" intensity of low-intensity muscle contractions caused by reduced blood flow (EC160) or high-intensity muscle contractions. Given the magnitude of the changes in pH(v), P(v)CO(2), and [L(-)](v), it appears plausible that they may be involved in stimulating the observed increase in muscle activation via group III and IV afferents.

Serum ferritin is linked with aortic stiffness in apparently healthy Korean women

BACKGROUND

There has been strong recent interest in the association between serum ferritin concentrations and increased risk of cardiovascular events. Surplus nutrition and convenience-seeking behavior has contributed to emergence of an increasingly obese population, with a concurrent increase in the prevalence of cardiovascular diseases. To date, few studies have specifically examined the association between serum ferritin and aortic stiffness in healthy populations, thus we investigated the association between serum ferritin and aortic stiffness according to sex and obesity in healthy subjects.

METHODS AND RESULTS

From a register of 196 healthy subjects (146 males, 50 females) 23 to 76 years of age, we measured BMI, serum ferritin, blood pressures, metabolic variables, and brachial ankle pulse wave velocity (baPWV). The average baPWV, serum ferritin and the sociodemographic prevalence (smoking, alcohol, and exercise) were higher in men than women. There was a positive association between serum ferritin and baPWV (R = 0.02) in total subjects after adjusting for age, sex, and blood pressures. The association between serum ferritin and baPWV (R = 0.099) in women was positive, yet negative in men (R = -0.007). The average baPWV and serum ferritin were highest in obese men, on the other hand lowest in nonobese women among 4 groups according to sex and obesity.

CONCLUSIONS

In conclusion, there was a stronger association between serum ferritin and PWV in healthy Korean women than men. Our finding suggests that cardiovascular risk factor monitoring through baPWV should be considered for even apparently healthy Korean women.

[Effect of nattokinase on restenosis after percutaneous transluminal angioplasty of the abdominal artery in rabbits]

OBJECTIVE

To investigate the effect of nattokinase on intimal hyperplasia in rabbit abdominal artery after balloon injury and explore a novel strategy for the preventing restenosis after percutaneous transluminal angioplasty.

METHODS

Fifty-six New Zealand rabbits were randomly divided into 7 groups, namely the solvent control group, model group, natto extract lavage group, refined nattokinse lavage group, intravenous refined nattokinse injection group, clopidogrel group and clopidogrel-aspirin group. Balloon injury was induced by inserting the catheter through the femoral artery into the thoracic aorta of the rabbits. The platelet counts were notad and platelet aggregation was observed, and the abdominal artery was taken for pathological analysis. The expressions of MMP-2 and -9 in the abdominal artery were detected immunohistochemically.

RESULTS

There was no significant difference in the platelet counts, platelet aggregation rate or MMP-2 and -9 expression between the model group and the nattokinse-treated groups (P>0.05). The stenosis index in each nattokinse-treated group was significantly greater and the neointimal proliferation index smaller than that of the model group (P<0.01 or 0.05).

CONCLUSION

Nattokinse can inhibit restenosis of rabbit abdominal artery after percutaneous transluminal angioplasty, which is independent of its actions on the platelet or MMP-2 and -9 expressions.

Serum YKL-40 as a marker of disease activity and stricture formation in patients with Crohn's disease

BACKGROUND AND AIM

YKL-40 is secreted by macrophages and neutrophils and is a growth factor for vascular endothelial cells and fibroblasts. Elevated serum levels of YKL-40 have been reported in patients with various inflammatory conditions and ongoing fibrosis. The aim of this study was to investigate the relationship between serum concentrations of YKL-40 and disease activity, acute phase reactants, and the presence of strictures in patients with Crohn's disease (CD).

METHODS

We studied the serum concentrations of YKL-40 in 41 patients with CD, in which 12 had an endoscopically- or radiologically-proven stricture formation. Forty-six age- and sex-matched healthy volunteers served as controls and a multivariate regression analysis was performed to find out the independent predictors of intestinal strictures and clinical activity.

RESULTS

The serum YKL-40 concentrations in the patients were significantly higher than that in the healthy controls (105.69 +/- 88.08 ng/mL [range 20.23-333.57]vs 44.92 +/- 24.89 ng/mL [range 18.31-113.43], P = 0.000) and patients with a stricture formation had significantly higher YKL-40 levels than those without strictures (167.50 +/- 119.30 ng/mL [range 23.62-333.57]vs 80.12 +/- 56.38 ng/mL [range 20.23-259.19], P = 0.003). Significant correlations were noted between YKL-40 levels and clinical activity (r = 0.681; P = 0.000) and the presence of intestinal strictures (r = 0.457; P = 0.003). The multivariate regression analysis found the serum YKL-40 levels to be an independent predictor of intestinal strictures (P = 0.001) and clinical activity (P = 0.001).

CONCLUSION

Patients with CD, particularly those with a stricture formation, have significantly higher levels of YKL-40. YKL-40 seems to be a useful marker of disease activity as well as stricture formation in patients with CD.

[Serum levels of Apo-AI and B as markers of synthetic graft stenosis after bypass for peripheral artery disease]

BACKGROUND

Hyperlipidemias are the main risk factors for atherosclerosis and cardiovascular disease. Nevertheless, the protein fractions of these lipids such as apolipoprotein B (Apo-B) can lead to arterial obstruction. In this study we investigated levels of apolipoproteins AI and B in patients with chronic occlusive peripheral arterial disease (PAD) of the lower extremities and their association with either patency or stenosis of synthetic grafts.

METHODS

This cohort study included 24 patients with chronic occlusive PAD who underwent infrainguinal revascularization with polytetrafluoroethylene (PTFE) synthetic graft. Patients were divided into two groups according to whether or not they were exposed to Apo-B, thus integrating two cohorts: the unexposed group (group 1, normal levels of Apo-B) and the exposed group (group 2, high levels of Apo-B). Variables investigated at 3, 6 and 12 months included arm/ankle index (AAI) and its association with levels of Apo-AI and Apo-B, and levels of cholesterol, triglycerides, and fibrinogen.

RESULTS

The study was comprised of 67% men and 33% women. Average age was 65.2 +/- 8.4 years. There was a correlation between AAI and high levels of Apo-B (p <0.001). Apo-AI levels were not significantly different between groups. Fibrinogen remained elevated in both groups with no statistical difference. Triglycerides demonstrated a significant difference between groups in basal measurements (p <0.05). Cholesterol remained normal in both groups without statistical difference.

CONCLUSIONS

This study demonstrates that patients exposed to high levels of Apo-B had synthetic graft failure (obstruction), as demonstrated by AAI <1.

[Interest of serologic markers in inflammatory bowel disease. About 105 cases]

BACKGROUND

The serum markers ASCA and pANCA can help the clinician in certain difficult situations of colites in IBD. The aim of this study was to determine the sensitivity and the specificity of each one of these markers and to establish the characteristics of the positive patients for each one.

METHODS

We included patients having a Crohn's disease (CD) or an ulcerative colitis (UC). These patients was compared to a control group.

RESULTS

80 CD patients with an average age of 35.62 years, 25 UC cases with an average age of 34.92 years and 79 healthy subjects with an average age of 34.2 years were included. The ASCA were detected in 33.8% of CD cases , 8% of UC cases of RCH and 2.5% of contro group (p < 000.1). The pANCA were detected in 48% of UC cases, 27.5% of CD patients and 1.3% of controls (p < 000.1). The sensitivity and the specificity of the ASCA and the pANCA for the diagnosis respectively of CD and UC were 33.8%, 97.5% and of 48%, 97.8%. During the CD, the positivity of the ASCA was significantly associated with ileal location (p = 0.001), with the sténosant and/or fistulisant phenotyp of the disease (p = 0.006), the young age at the time of the diagnosis of the CD (p = 0.067) and at a greater frequency of surgical treatment (p = 00.7). The pANCA were more frequently found in colic location of CD (p = 0.09). During UC, the positivity of the pANCA was not associated with the sex, age, loca tion of the disease, medical treatment nor chiurgical treatment.

CONCLUSION

The ASCA and pANCA are useful during some clinical situations such as differentiation between IBD otherss colitis and to distinguish CD from UC.

Over-expression of IGF-related peptides in stenoses of native arteriovenous fistulas in hemodialysis patients

INTRODUCTION

Insulin-like growth factors (IGFs) are known to play an important role in atherogenesis. The aim of our study was to assess the local expression of IGF-related peptides in stenosed hemodialysis fistulas and compare these with their respective serum levels.

METHODS

We investigated 15 stenosed vein segments of primary arteriovenous fistulas, 29 non-stenosed control vein segments from uremic patients and 15 non-stenosed control saphenous vein segments. Immunohistochemistry was performed for IGF-I, insulin, IGF-binding proteins (IGFBPs)-1, -2, -3 and -4, the acid labile subunit (ALS) and type 1 IGF-receptor (IGF-R). Serum levels were measured by specific radioimmunoassays.

RESULTS

Compared to both control groups, a significantly higher expression of the following IGF-related peptides was seen in the stenotic (neo)intima: IGF-I, IGFBP-1, -2, -3, -4 and IGF-R; in the stenotic media: IGF-I and IGFBP-3 and in the endothelium of stenotic fistulas: IGF-I (all p<0.05). Staining against ALS and insulin was negative in all vessels. Serum IGF-I levels did not differ. Serum levels of IGFBP-1, -2, -3 and -4 were significantly higher in patients with renal disease (all p<0.05). There were no correlations between local and systemic IGF-related peptide levels. There were correlations of neointimal expression of IGF-I, IGFBP-1, -2, -3, -4 and IGF-R with both hypercellularity and the presence of inflammatory cells (p<0.05).

CONCLUSION

In the stenotic arteriovenous fistula of hemodialysis patients, expression of the peptides IGF-I, IGFBP-1, -2, -3, -4 and IGF-R was significantly increased and showed a positive correlation with neointimal inflammation and hypercellularity (all p<0.05). IGF-related peptides are most likely synthesized locally and might be involved in the initiation and/or progression of neointimal thickening of primary arteriovenous fistulas.

C-Reactive Protein Level in Severe Stenosis of Cerebral Arteries

BACKGROUND

C-reactive protein (CRP) as a non-specific inflammatory biomarker has been demonstrated to actively contribute to all stages of atherogenesis. The aim of this study was to investigate the relation between CRP concentrations and the severity of stenosis of cerebral arteries.

METHODS

Lipid parameters and CRP levels were measured in the sera of 119 patients with stenosis of the extracranial cerebral arteries established by angiography and compared with the control group, with a normal appearance of the cerebral arteries on ultrasound examination. CRP concentrations were determined by a high-sensitivity assay.

RESULTS

CRP concentrations showed a statistically significant difference in the group of patients with cerebrovascular stenosis of more than 70% compared to the control group (median value 3.4 vs. 1.5 mg/l in the control group, p < 0.05). At logistic regression analysis, CRP was significantly associated with stenosis of more than 70%.

CONCLUSION

In addition to traditional biochemical risk markers, an elevated CRP level measured on automated analysers using a high-sensitivity assay may be useful in the detection of patients with severe stenosis of the cerebral arteries.

Three-phase CFD analytical modeling of blood flow

The behavior of blood cells in disturbed flow regions of arteries has significant relevance for understanding atherogenesis. However, their distribution with red blood cells (RBCs) and leukocytes is not so well studied and understood. Our three-phase computational fluid dynamics approach including plasma, RBCs, and leukocytes was used to numerically simulate the local hemodynamics in such a flow regime. This model has tracked the wall shear stress (WSS), phase distributions, and flow patterns for each phase in a concentrated suspension shear flow of blood. Unlike other computational approaches, this approach does not require dispersion coefficients as an input. The non-Newtonian viscosity model was applied to a wide physiological range of hematocrits, including low shear rates. The migration and segregation of blood cells in disturbed flow regions were computed, and the results compared favorably with available experimental data. The predicted higher leukocyte concentration was correlated with relatively low WSS near the stenosis having a high WSS. This behavior was attributed to flow-dependent interactions of the leukocytes with RBCs in pulsatile flow. This three-phase hemodynamic analysis may have application to vulnerable plaque formation in arteries with in vivo complex flow conditions.

Markedly elevated serum CA 19-9 levels in association with a benign biliary stricture due to primary sclerosing cholangitis

We report on the case of a 55-year-old man with long-standing ulcerative colitis who developed jaundice. This led to a diagnosis of primary sclerosing cholangitis being made, with a dominant stricture in the common bile duct. Serum CA 19-9 was initially markedly raised at 26,321 U/mL but fell promptly into the normal range after stenting of the stricture. Long-term follow up of this patient has failed to show evidence of cholangiocarcinoma. We conclude that serum CA 19-9 levels need to be assessed in the clinical context of biliary obstruction and should ideally be measured after relief of that obstruction, as it may be falsely elevated due to benign biliary strictures.

[Effects of Sini decoction on vascular stenosis after iliac artery balloon injury and oxidative stress in rabbits]

OBJECTIVE

To investigate the effect of Sini decoction (SND) in preventing vascular restenosis and protecting against oxidative stress after rabbit iliac artery balloon injury.

METHODS

Twenty-four male New Zealand albino rabbits were equally randomized into control group, model group and SND group. Rabbits in the control group were fed with common forage, and those in the model and SND groups with high-fat diet. Two weeks later, the iliac arteries of the rabbits in the latter two groups were subjected to balloon injury. Four weeks after the operation, the rabbits were killed and the vascular structure was observed by scanning electron microscope and optical microscope, with the serum cholesterol level, superoxide dismutase (SOD) activity and malondialdehyde (MDA) level determined.

RESULTS

Scanning electron microscopy showed that the endothelial cell lining in the iliac artery of the control and SND group remain regular, but the arteries in the model group presented with desquamated and exposure of the collagen fibril beneath the endothelium. Optical microscope revealed narrowed vascular lumen, thicken intima and numerous arteriosclerotic plaques in the model group in comparison with the control group, whereas the vascular lumen and intima thickness remained basically normal in SND group. The levels of total cholesterol, low-density lipoprotein cholesterol and triglyceride were decreased with high-density lipoprotein cholesterol levels increased in SND group, which was not observed in the model group. The serum SOD activity was higher in the control group than in the model and SND groups, but SND group had higher serum SOD activity than the model group. The serum MDA level was lower in the control group than in the other two groups, but SND group had lower MDA level than the model group.

CONCLUSION

SND can alleviate intimal hyperplasia and vascular stenosis in injured rabbit iliac artery, possibly in relation to increased SOD activity and decreased lipid peroxidation as a result of SND treatment.

Inflammatory response after influenza vaccination in men with and without carotid artery disease

OBJECTIVE

Inflammatory markers are associated with vascular disease; however, variation in the acute phase response (APR) has not been evaluated. We evaluated whether the APR magnitude in men with severe carotid artery disease (CAAD) (>80% stenosis) differed from that of men without stenosis (<15% stenosis).

METHODS AND RESULTS

White males with (n=43) and without (n=61) severe CAAD receiving clinical influenza vaccinations were recruited. Their baseline and 24-hour after -vaccination blood samples were assayed for C-reactive protein (CRP), IL-6, and serum amyloid-a (SAA). In vivo APR to vaccination was measurable and varied among subjects. Adjusted for age, smoking, oral hypoglycemics, aspirin, and stain use, the relative 24-hour changes in levels of ln(CRP), ln(IL-6), and ln(SAA) were higher in men with CAAD than in men without, but only the SAA response was significant (P=0.02); the relative SAA response was 1.6 (95% confidence interval, 1.1 to 2.5) times higher in men with than without CAAD. The APR for all markers appeared to be independent of baseline levels.

CONCLUSIONS

Influenza vaccination results in a mild, but measurable, APR in men with and without CAAD. SAA APR variability may be a predictor of severe vascular disease that is independent of basal SAA level.

Intense Vasoconstriction in Response to Aspirate From Stented Saphenous Vein Aortocoronary Bypass Grafts

OBJECTIVES

We sought to identify soluble vasoconstrictor substances that are released during stent implantation into saphenous vein aortocoronary bypass grafts.

BACKGROUND

Atherosclerotic saphenous vein aortocoronary bypass grafts are particularly vulnerable to plaque rupture. Protection devices prevent particulate debris from being embolized. Additional soluble vasoconstrictor substances possibly also contribute to impaired microvascular perfusion.

METHODS

Peripheral venous blood (VB) and aspirate (AS) were obtained from 14 patients with a significant stenosis in a saphenous vein graft during stent implantation under protection with a distal balloon occlusion device. In five additional patients, arterial blood (AB) was also taken distal to the stented lesion before intervention. Vasomotor substances in VB, AB, and AS plasma were identified in a bioassay of rat mesenteric arteries with intact (+E) and denuded endothelium (-E). Vasoconstriction was normalized to that induced by potassium chloride depolarization (100%).

RESULTS

Venous blood, AB, and AS plasma induced maximum vasoconstriction within six minutes. The AS plasma induced a vasoconstriction of 138 +/- 13% (-E) and 87 +/- 14% (+E); VB, of 70 +/- 14% (-E) and 23 +/- 4% (+E); and AB plasma obtained before intervention, of 49 +/- 9% (-E) and 36 +/- 8% (+E). The vasoconstrictor potency of AS plasma in endothelium-denuded vessels was related to the severity of anginal symptoms, angiographic stenosis severity, plaque volume, and plaque burden as determined by intravascular ultrasound. The AS plasma-induced vasoconstriction was largely attenuated by combined serotonin/5-hydroxytryptamine (5-HT)(2A/2C)- and 5-HT(1A/1B)-receptor blockade and eliminated by additional thromboxane A2 thromboxane-prostanoid (TP)-receptor blockade.

CONCLUSIONS

Stent implantation releases, apart from and in addition to particulate debris, soluble vasoconstrictor substances that possibly contribute to impaired microvascular perfusion.

Impact of dominant stenoses on the serum level of the tumor marker CA19-9 in patients with primary sclerosing cholangitis

BACKGROUND/AIMS

Patients with primary sclerosing cholangitis (PSC) have an increased risk of developing hepatobiliary tumors. The tumor marker CA19-9 was claimed to indicate the occurrence of bile duct carcinoma. This study aimed to assess whether increased serum levels of CA19-9 in PSC patients with dominant stenoses indicate bile duct carcinoma.

METHODS

The study cohort comprised 106 patients treated over a median time of 5.0 years (range 0.5 - 13 years). All patients were treated with ursodeoxycholic acid (UDCA) and whenever they developed dominant stenoses by endoscopic dilatation of these stenoses. In endoscopically treated patients, CA19-9 levels were measured before and 3, 6, 12 and 24 months after endoscopic dilatation.

RESULTS

Of the 106 patients, 22 carcinoma-free patients and 3 patients with bile duct carcinoma had elevated CA 19 - 9 levels. In 14 out of 25 patients with elevated CA19-9 levels, dominant stenoses were diagnosed and treated by endoscopic dilatation. In 71.4 % of the endoscopically treated patients, CA19-9 levels decreased following the endoscopic intervention.

CONCLUSIONS

In PSC patients, increased serum levels of CA19-9 are rarely due to the development of bile duct carcinoma. In patients with dominant stenoses, the relief of biliary obstruction by endoscopic dilatation may lead to a decrease of the serum levels of CA19-9.

Duct-narrowing chronic pancreatitis without immunoserologic abnormality: comparison with duct-narrowing chronic pancreatitis with positive serological evidence and its clinical management

We reviewed the clinical features and clinical course of patients with duct-narrowing chronic pancreatitis who were negative for immunoserologic test results (n = 16) in comparison with the findings for serological test-positive patients (n = 20) in order to determine an adequate treatment for those who had typical morphology of autoimmune pancreatitis in the absence of immunoserologic abnormality. No significant differences were found between the two groups of patients in clinical profiles including associated autoimmune-related diseases, pancreatic histology, and response to steroid therapy. Of the seronegative patients, eight who showed an improvement in narrowing of the main pancreatic duct with steroid therapy and three who did no show an improvement or who relapsed after surgical resection without this therapy had stenosis of the common bile duct with increased levels of serum hepatobiliary enzymes, except for two patients with affected sites limited to the body or tail of the gland. For the remaining five patients, who showed an improvement in pancreatic duct changes or long-term remission after surgery without steroid administration, normal biochemistry test results for liver functions were obtained, with no abnormal cholangiographic findings in the three patients examined. Duct-narrowing chronic pancreatitis without immunoserologic abnormality overlaps in clinical features with that fulfilling the immunoserologic criteria for a diagnosis of autoimmune pancreatitis. In particular, the disease with bile duct involvement should be treated clinically as autoimmune pancreatitis, for which steroid therapy is recommended, even if an autoimmune mechanism is not demonstrated serologically.

Platelet shape change and subsequent glycoprotein redistribution in human stenosed arteries

Shear stress encountered in stenosed human arteries is able to induce a certain range of platelet activation. In order to determine the extent of platelet shape change induced by high shear rate conditions, we used electron microscopy (EM) and immuno-EM to study platelet ultrastructure from blood flowing in vivo through stenosed arteries. Then it was compared with platelets from healthy controls exposed in vitro to a shear rate of 4000 s(-1). Six patients with stenosed arteries (iliac, femoral and renal) were investigated at the time of transcutaneous angiography. Blood was harvested from the same catheter in the stenosed artery and in the abdominal aortic artery (control sample), each patient being its own control. The percentage of platelets with shape changes (loss of discoid form, pseudopod emission, organelle centralisation) significantly increased in samples from stenosed arteries. Shape change was concomitant with the membrane glycoprotein IIb-IIIa distribution at the pseudopod extremities. These activated platelets had not completed secretion and were maintained in a reversible activation state. Similar results were obtained on platelets from healthy donors submitted in vitro to a high shear rate. In conclusion, this study shows that the high shear rate encountered in human stenosed arteries is able to induce shape change and reversible activation of platelets in vivo.

Ratios of homocysteine and nitrite to high-density lipoprotein in coronary artery patients with the different degree of stenosis

Although the interaction between Hcy, NO(2)(-) and vascular disease has been extensively studied, there are no data verifying their ratios to HDL-C in coronary artery disease (CAD). We examined whether Hcy/HDL-C and NO(2)(-)/HDL-C ratios correlated with the degree of stenosis in CAD. Also, TC/HDL-C and LDL-C/HDL-C ratios were evaluated in the same individuals. Seventy subjects were divided into three groups according to coronary angiography findings: >50% stenosis (n=35, years: 50.9+/-3.4; Group 1), 5-50% stenosis (n=20, years: 50.6+/-3.8; Group 2), <5% narrowing (n=15, years: 49.0+/-3.2; control group). Hcy/HDL-C, NO(2)(-)/HDL-C, TC/HDL-C and LDL-C/HDL-C were statistically higher in both Group 1 patients (p=0.001, for all ratios) and Group 2 patients (p=0.001, p=0.001, p=0.03, 0.041, respectively) with respect to controls. The values were correlated with the degree of stenosis in the different significance levels (r=0.496, p=0.001; r=0.384, p=0.004; r=0.334, p=0.012; r=0.321, p=0.016, respectively). In patients with >50% stenosis, NO(2)(-)/HDL-C was only shown to change significantly in relation to obstructive artery number (p=0.026) and also showed a positive correlation (r=0.379, p=0.032). In conclusion, Hcy/HDL-C and NO(2)(-)/HDL-C appear to be more indicative than TC/HDL-C and LDL-C/HDL-C in the evaluation of CAD patients regarding the degree of stenosis. However, only NO(2)(-)/HDL evaluation seems to be a reliable indicator in the patients with heavy stenosis of CAD. Further studies are needed to confirm the results of present study.

Biochemical and radiological predictors of malignant biliary strictures

AIM: Differentiation of benign biliary strictures (BBS) from malignant biliary strictures (MBS) remains difficult despite improvement in imaging and endoscopic techniques. The aim of this study was to identify the clinical, biochemical and or radiological predictors of malignant biliary strictures.

METHODS: We retrospectively reviewed all charts of patients who had biliary strictures (BS) on endoscopic retrograde cholangiopancreatography (ERCP) or percutaneous cholangiography (PTC) in case of unsuccessful ERCP from March 1998 to August 2002. Patient characteristics, clinical features, biochemical, radiological and biopsy results were all recorded. Stricture etiology was determined based on cytology, biopsy or clinical follow-up. A receiver operator characteristic (ROC) curve was constructed to determine the optimal laboratory diagnostic criterion threshold in predicting MBS.

RESULTS: One hundred twenty six patients with biliary strictures were enrolled, of which 72 were malignant. The mean age for BBS was 53 years compared to 62.4 years for MBS (P = 0.0006). Distal bile duct stricture was mainly due to a malignant process 48.6% vs 9% (P = 0.001). Alkaline phosphates and AST levels were more significantly elevated in MBS (P = 0.0002). ROC curve showed that a bilirubin level of 84 μmol/L or more was the most predictive of MBS with a sensitivity of 98.6%, specificity of 59.3% and a positive likelihood ratio of 2.42 (95%CI: 0.649-0.810). Proximal biliary dilatation was more frequently encountered in MBS compared to BBS, 73.8% vs 39.5% (P = 0.0001). Majority of BBS (87%) and MBS (78%) were managed endoscopically.

CONCLUSION: A serum bilirubin level of 84 μmol/L or greater is the best predictor of MBS. Older age, proximal biliary dilatation, higher levels of bilirubin, alkaline phosphatase, ALT and AST are all associated with MBS. ERCP is necessary to diagnose and treat benign and malignant biliary strictures.

Changes in blood coagulability as it traverses the ischemic limb

OBJECTIVE

We undertook this study to determine whether changes in blood coagulability associated with peripheral arterial occlusive disease are due to contact with the atherosclerotic arterial wall or passage through distal ischemic tissue.

METHODS

Thirty patients with peripheral arterial occlusive disease undergoing angiography participated in the study. Ankle-brachial pressure index was recorded before intervention. Blood samples taken from the aorta, common femoral artery, and common femoral vein were analyzed at thromboelastography. Angiograms were scored for stenotic disease by a radiologist blinded to the other results.

RESULTS

When femoral artery samples were compared with aortic samples there was a decrease in reaction time (R; P <.05), an increase in maximum amplitude (MA; P <.05), and an increase in coagulation index (CI; P <.002), indicating an increase in coagulability as blood flowed down the iliac segment. These changes also correlated (DeltaR, r = 0.442, P <.05; DeltaMA, r = 0.379, P <.05; DeltaCI, r = 0.429, P <.05) with the severity of disease in the ipsilateral iliac segment. Significant differences in R (P <.05), angle (P <.05), MA (P <.005), and CI (P <.001) between common femoral arterial and venous samples confirmed that venous samples were more coagulable in this group of patients. This difference in Thromboelastography parameters across the arteriovenous segment correlated inversely with the degree of ischemia (represented by ankle-brachial pressure index; DeltaCI, r = -0.427, P <.05; DeltaMA, r = -0.370, P <.05) in the puncture side limb.

CONCLUSION

Passage of blood down an atherosclerotic artery leads to an increase in coagulability proportional to the degree of stenosis in that vessel. Passage of blood through ischemic tissue may also contribute to increased coagulability in peripheral arterial occlusive disease.

Platelet distribution width (PDW) is increased in vaso-occlusive crisis in sickle cell disease

Considering the multigenic and multifactorial nature of the disease, we argue that a generalized bone marrow hyperplasia-and not merely erythroid hyperplasia-will occur in sickle cell disease. Consequently, we expect the hematological parameters to depict erythroid, myeloid as well as megakaryocyte hyperplasia. In the light of this expectation, we hypothesized that platelet distribution width (PDW) will increase in sickle cell disease. Here, we report the results from a cross-sectional study of 216 children admitted with complaints suggestive of vaso-occlusive crisis. We observed a strong association between PDW and sickle cell disease as compared to children who had HbAA genotype. Our findings bridge previous inconsistencies relating to the role of platelets in sickle cell disease. Implications of this finding are discussed.

Effect of low-dose warfarin on D-dimer levels during sickle cell vaso-occlusive crisis: a brief report

OBJECTIVE

To evaluate the activation of clotting systems in patients with sickle cell disease (SCD) by measuring the plasma D-dimer level and to determine the effect of low-dose warfarin on D-dimer level during vaso-occlusive crisis.

METHODS

Plasma D-dimer level was measured in 65 blood samples of 37 adult patients with SCD who were hospitalized for vaso-occlusive painful crisis. D-dimer level of patients who were on low-dose warfarin was compared with those patients who were not on any anticoagulation treatment. Analysis of variance (anova) was carried out to determine factors significantly associated with low D-dimer level in patients with SCD. The following factors were included in the anova model; warfarin, homozygous hemoglobin S, history of blood transfusion in past 3 months, hydroxyurea, hemoglobin S%, hemoglobin F%, white blood cell counts, hemoglobin level, platelet count, and plasma fibrinogen level.

RESULTS

Overall median D-dimer level in 65 samples was 2.7 microg fibrinogen equivalent units (FEU)/mL (0.34-4). Patients who were on low-dose warfarin had a median D-dimer level of 0.81 microg FEU/mL (0.34-1.8) compared with 3.1 microg FEU/mL (0.94-4) in those patients who were not on anticoagulation treatment. Using anova to model D-dimer levels, only warfarin was significantly correlated with low D-dimer levels after controlling for other variables.

CONCLUSIONS

Patients with SCD during vaso-occulsive painful crisis have an elevated D-dimer level. Low-dose anticoagulation treatment is associated with a significant reduction in the D-dimer levels.

Number and adhesive properties of circulating endothelial progenitor cells in patients with in-stent restenosis

OBJECTIVE

Intact endothelialization machinery is essential to facilitate vessel healing after stent placement and to prevent restenosis. Circulating endothelial progenitor cells (EPC) have been demonstrated in the peripheral blood and shown to display endothelial functional properties, along with the ability to traffic to damaged vasculature. We reasoned that robust in-stent intimal growth could be partially related to impaired endothelialization resulting from reduced circulating EPC number or function.

METHODS AND RESULTS

Sixteen patients with angiographically-demonstrated in-stent restenosis were compared with patients with a similar clinical presentation that exhibited patent stents (n=11). Groups were similar with respect to the use of drugs that could potentially influence EPC numbers. Circulating EPC numbers were determined by the colony-forming unit assay, and their phenotype was characterized by endothelial-cell markers. Adhesiveness of EPC from both groups to extracellular matrix and to endothelial cells was also assayed. Patients with in-stent restenosis and with patent stents displayed a similar number of circulating EPC. Fibronectin-binding was compromised in patients with in-stent restenosis as compared with their controls exhibiting patent stents. Patients with diffuse in-stent restenosis exhibited reduced numbers of EPC in comparison with subjects with focal in-stent lesions.

CONCLUSIONS

Reduced numbers of circulating EPC in patients with diffuse in-stent restenosis and impaired adhesion of EPC from patients with restenosis provides a potential mechanism mediating the exuberant proliferative process. These markers, if further validated, could provide means of risk stratifying patients for likelihood of developing in-stent restenosis.

Hepatic venous stenosis-related reduction of cyclosporin clearance in a pediatric patient after liver transplantation

A 20-month-old girl with Alagille syndrome developed stenosis of hepatic venous anastomosis after living related-donor liver transplantation. Cyclosporin (a microemulsion formulation) was given orally at a dose of 50 mg twice daily, and the trough blood concentration was relatively stable. Before balloon angioplasty of the hepatic vein, trough cyclosporin blood concentrations became elevated and consequently, the dosage was reduced to 15 mg twice daily. On the day of angioplasty, the calculated elimination rate constant of cyclosporin was 0.036 hr(-1), while its apparent basal value was 0.078 hr(-1). The cyclosporin trough concentration to dosage (C/D) ratio gradually increased reaching the maximum on the day after angioplasty. Thereafter, the C/D ratio promptly decreased. Thus, it is speculated that the increase in cyclosporine C/D ratio was mainly dependent on reduction of hepatic clearance of cyclosporin due to hepatic congestion caused by the stenosis of the hepatic venous anastomosis.

Impact of simvastatin, niacin, and/or antioxidants on cholesterol metabolism in CAD patients with low HDL

The HDL Atherosclerosis Treatment Study (HATS) demonstrated a clinical benefit in coronary artery disease patients with low HDL cholesterol (HDL-C) levels treated with simvastatin and niacin (S-N) or S-N plus antioxidants (S-N+A) compared with antioxidants alone or placebo. Angiographically documented stenosis regressed in the S-N group but progressed in all other groups. To assess the mechanism(s) responsible for these observations, surrogate markers of cholesterol absorption and synthesis were measured in a subset of 123 HATS participants at 24 months (on treatment) and at 38 months (off treatment). Treatment with S-N reduced desmosterol and lathosterol levels (cholesterol synthesis indicators) 46% and 36% (P < 0.05), respectively, and elevated campesterol and beta-sitosterol levels (cholesterol absorption indicators) 70% and 59% (P < 0.05), respectively, relative to placebo and antioxidant but not S-N+A. Treatment with antioxidants alone had no significant effect. Combining S-N with antioxidants reduced desmosterol and lathosterol by 37% and 31%, and elevated campesterol and beta-sitosterol levels by 54% and 46%, but differences did not attain significance. Mean change in percent stenosis was positively associated with a percent change in lathosterol (r = 0.26, P < 0.005) and negatively associated with a percent change in beta-sitosterol (r = -0.21, P < 0.01). These data suggest that changes in stenosis were attributable, in part, to changes in cholesterol metabolism.

L-arginine levels are diminished in adult acute vaso-occlusive sickle cell crisis in the emergency department

Paediatric studies have demonstrated that l-arginine (l-arg), the precursor to nitric oxide, is diminished in vaso-occlusive crisis (VOC). This study aimed to determine whether l-arginine levels are altered in adult VOC in the emergency department. Plasma l-arg and nitric oxide metabolite (NOx) levels were obtained in adult VOC patients presenting to the emergency department. Fifty patients had significantly low plasma l-arg (29.78 micromol/l +/- 11.21, P < 0.05 vs steady-state control = 41.16 micromol/l +/- 5.04) and significantly low plasma NOx (12.33 micromol/l +/- 10.28, P < 0.05 vs steady-state control = 25.2 +/- 2.6 micro mol/l). Neither l-arg nor NOx levels could predict VOC clinical course.

Biochemical risk factors in angiographically established stenosis of cerebral arteries

AIM

To determine the significance of the association between biochemical risk factors for cerebrovascular atherosclerosis (lipid parameters, lipoprotein(a), total homocysteine, total antioxidant status, trace elements, and electrolytes) and the degree of stenosis of cerebral arteries scored by digital subtraction angiography.

METHODS

The study included 35 patients with angiographically established < 50% stenosis of cerebral arteries and 55 patients with > or =50% stenosis of cerebral arteries, including obliteration. The control group consisted of 51 patients with normal cerebral arteries on ultrasound examination. Biochemical parameters were measured in all participants according to the standard laboratory protocols.

RESULTS

Logistic regression analysis showed two independent and significant biochemical risk factors associated with the severity of cerebrovascular stenosis: lipoprotein(a) for patients with different degrees of stenosis, and total antioxidant status for patients with severe stenosis of more than 50%. Univariate statistical evaluation showed significantly higher homocysteine levels in the group of patients with > or =50% stenosis than in the control group (median 14.84 micromol/L vs median 12.40 micromol/L, p < 0.05).

CONCLUSION

Increased lipoprotein(a) and low total antioxidant status values seem to be the most significant independent biochemical risk factors for the development of cerebrovascular stenosis. Mild hyperhomocysteinemia seems to be an additional discriminating indicator of the severe cerebrovascular stenosis. These factors may be useful for early identification and recognition of patients with cerebrovascular atherosclerosis.

Platelet aggregation and activation under complex patterns of shear stress

Arterial stenosis results in a complex pattern of blood flow containing an extremely fast flow in the throat of stenosis and a post-stenosis low flow. The fast flow generates high shear stress that has been demonstrated in vitro to activate and aggregate platelets. One potential problem of these in vitro studies is that platelets are invariably exposed to a high shear stress for a period that is significantly longer than they would have experienced in vivo. More importantly, the role of the post-stenosis low flow in platelet activation and aggregation has not been determined. By exposing platelets to a shear profile that contains both high and low shear segments, we found that platelets aggregate when they are exposed to a high shear stress of 100 dyn/cm(2) for as short as 2.5 s, a period that is significantly shorter than those previously reported (30-120 s). Platelet aggregation under this condition requires a low shear exposure immediately after a high shear pulse, suggesting that post-stenosis low flow enhances platelet aggregation. Furthermore, platelet aggregation under this condition is not activation-dependent because the CD62P expression of sheared platelets is significantly less than that of platelets treated with ADP. Based on these findings, we propose that shear-induced platelet aggregation may be a process of mechanical crosslinking of platelets, requiring minimal platelet activation. This process may function as a protective mechanism to prevent in vivo irreversible platelet activation and aggregation under temporary high shear.

Restenosis after percutaneous transluminal angioplasty in the femoropopliteal segment: the role of inflammation

PURPOSE

To determine the value of baseline C-reactive protein (CPR), fibrinogen, and white blood cell (WBC) counts in predicting 1-year patency after percutaneous transluminal angioplasty (PTA) in the femoropopliteal segment.

METHODS

In a retrospective cohort study, 168 consecutive patients (103 men; median age 70 years, interquartile range 61-77) who underwent successful PTA of the femoral and/or popliteal arteries were analyzed. Twelve-month patency was evaluated using oscillography, ankle brachial index, duplex sonography, and angiography. The predictive value of inflammatory markers was assessed in a multivariate model controlling for cardiovascular risk factors, technical success, and hemodynamic factors.

RESULTS

Transient WBC elevation was found 6 hours after PTA, but this returned to baseline after 24 hours. Fibrinogen was elevated at 24 hours. Duplex scanning disclosed restenosis in 66 (39%) patients within the first 12 months after PTA. Only residual postdilation stenosis (> or = 30%) in the target segment (odds ratio 3.6, p=0.001) and baseline CRP levels (odds ratio 4.2, p=0.02) were independent predictors of outcome; neither WBC counts nor fibrinogen levels at any time point was associated with restenosis.

CONCLUSIONS

Primary technical success and postinterventional hemodynamic flow at the dilated segment seem to be more important for intermediate-term patency than atherogenic risk factors. The predictive value of preprocedural serum CRP levels on restenosis should be further investigated.

Remnant-like lipoprotein particle cholesterol concentration and progression of coronary and vein-graft atherosclerosis in response to gemfibrozil treatment

Remnant lipoproteins such as chylomicron and very low density lipoprotein (VLDL) remnants have been implicated in the progression of coronary atherosclerosis. Recently, a novel method for the determination of the remnant-like lipoprotein particle cholesterol (RLP-C) concentration was developed based on immunoaffinity-separation of plasma. The compositional characteristics of RLP are strikingly similar to those of postprandially modified VLDL. In addition, the method also detects chylomicron remnants. We investigated the relationship between the plasma RLP-C concentration and the angiographic outcome of the 2-year, randomised, placebo-controlled Lipid Coronary Angiography Trial (LOCAT), which used gemfibrozil as lipid lowering agent. The RLP-C response to gemfibrozil treatment has not been described before. Gemfibrozil reduced the median RLP-C concentration by 34%. The on-treatment RLP-C concentration was significantly associated with the progression of the minimum lumen diameter (MLD) (P<0.004). The plasma levels of RLP-C as well as the change in response to treatment was closely associated with plasma triglycerides and the association between on-treatment RLP-C concentration and progression of MLD was not independent of plasma triglycerides. A significant relation was seen between RLP-C and the occurrence of new lesions in vein grafts. Subjects with one new lesion had an approximately 25% higher on-treatment RLP-C concentration and the four patients showing two new lesions had a 100% higher RLP-C concentration than patients without vein graft stenosis. A total of 19 out of 23 subjects having one new lesion, and all four patients showing two new lesions, were assigned to the placebo group. We conclude that the RLP-C concentration, which is likely to reflect the plasma cholesterol contained in postprandially modified VLDL and chylomicron remnants, is strongly associated with angiographically verified progression of focal coronary atherosclerosis, and that lowering of RLPs prevents vein graft stenosis.

Evaluation of C-reactive protein, a sensitive marker of inflammation, as a risk factor for stable coronary artery disease

OBJECTIVES

Multiple lines of investigations have converged to suggest a prominent role for inflammation in coronary artery disease (CAD). The association of CRP level with active CAD is well documented. The relation, however, between levels of CRP and the presence and extent of stable CAD has seldom been studied in the developing countries. We investigated the association between serum concentration of C-reactive protein (CRP) and angiographically documented coronary artery disease (CAD) in a population of 450 individuals.

DESIGN AND METHODS

Ultrasensitive immunoassay was used to measure CRP levels in 284 patients with CAD and 166 control healthy subjects. The association of CRP levels with severity of disease as indicated by > or = 50% stenosis in one vessel (n = 79), two vessels (n = 74), or three vessels (n = 131) was also investigated.

RESULTS

CRP levels were greater in the patients with CAD (2.14 (0.88--3.38) vs. 1.45 (0.70--2.55) mg/L, p < 0.0001) than in the respective control subjects. Multiple logistic regression analysis showed CRP as an independent discriminating risk factor for CAD (odds ratio, 3.46, p < 0.001). Significant correlation was identified between CRP levels and severity of CAD (p < 0.0001). Prediction models that incorporated CRP in addition to other established coronary risk factors were significantly better at predicting risk than the models based on the other risk factors alone. CRP level was also an independent predictor of CAD in a subpopulation with normal levels of low density lipoprotein cholesterol (LDL-C < or = 3.4 mmol/L, p < 0.009).

CONCLUSIONS

Our findings suggest that CRP has a strong association with stable CAD, as such, the measurement of CRP may improve the coronary risk assessment in Iranian CAD patients.

Characterization of simple and reproducible vascular stenosis model in hypercholesterolemic hamsters

The importance of low-density lipoprotein (LDL) in the etiology of atherosclerosis is well recognized. We have established a reproducible stenosis model in hypercholesterolemic hamsters, and the process of arterial stenosis by thrombus or neointima was studied and compared with that in normal hamsters. The level of plasma LDL was 4.6 times higher in hamsters fed a high-cholesterol diet than in hamsters fed normal food. Endothelial injury in right common carotid arteries was induced using a modified catheter. Arterial blood flow was monitored continuously using a Doppler flow probe. Arterial patency after the initiation of injury in high-cholesterol hamsters was significantly changed as compared with that of normal hamsters. Neointima was observed 2 wk after the vascular injury. The neointimal area of high-cholesterol hamsters was significantly larger than that of normal hamsters. To characterize the stenosis in hypercholesterolemic hamsters, we measured platelet aggregation, thrombin time, activated partial thromboplastin time, and proliferating smooth muscle cells (SMC) in vitro and in vivo. The half-maximal inhibitory concentration value for platelet aggregation induced by thrombin or collagen, the DNA synthesis stimulated by platelet-derived growth factor (PDGF)-BB, and 5-bromo-2-deoxy-uridine labeling indices (proliferating index of SMC in vivo) in high-cholesterol hamsters were each significantly higher than the comparable value from normal hamsters. However, specific binding of PDGF-BB in SMC was not different between the two types of hamsters. Furthermore, we investigated the inhibitory effects of probucol or losartan on neointima formation using this model. Probucol, but not losartan, significantly reduced the neointimal area in hypercholesterolemic hamsters. These findings indicated that high levels of plasma LDL strongly contributed to the development of thrombus and neointima formation via both up-regulation of platelet aggregation and the enhancement of SMC proliferation. This stenosis model may be useful for the investigation of hypercholesterolemia-associated cardiovascular diseases.