Growth Hormone, Atherosclerosis and Peripheral Arterial Disease: Exploring the Spectrum from Acromegaly to Growth Hormone Deficiency.

Growth hormone (GH) and insulin-like growth factor 1 (IGF-1) are increasingly recognised for their role in cardiovascular (CV) physiology. The GH-IGF-1 axis plays an essential role in the development of the CV system as well as in the complex molecular network that regulates cardiac and endothelial structure and function. A considerable correlation between GH levels and CV mortality exists even among individuals in the general population without a notable deviation in the GHIGF- 1 axis functioning. In addition, over the last decades, evidence has demonstrated that pathologic conditions involving the GH-IGF-1 axis, as seen in GH excess to GH deficiency, are associated with an increased risk for CV morbidity and mortality. A significant part of that risk can be attributed to several accompanying comorbidities. In both conditions, disease control is associated with a consistent improvement of CV risk factors, reduction of CV mortality, and achievement of standardised mortality ratio similar to that of the general population. Data on the prevalence of peripheral arterial disease in patients with acromegaly or growth hormone deficiency and the effects of GH and IGF-1 levels on the disease progression is limited. In this review, we will consider the pivotal role of the GH-IGF-1 axis on CV system function, as well as the far-reaching consequences that arise when disorders within this axis occur, particularly in relation to the atherosclerosis process.

Endocrine Disorders and Peripheral Arterial Disease - A Series of Reviews Cushing Syndrome-Cortisol Excess.

Cushing syndrome (CS), characterised by endogenous or exogenous glucocorticoid hormone excess, is associated with several systemic complications, including impaired glucose metabolism, which often becomes clinically manifest as diabetes mellitus (DM). In addition, CS can harm the arterial wall because of hyperglycaemia, dyslipidaemia, hepatic steatosis, and central obesity. These metabolic disorders promote atherosclerosis by synthesising adipokines, leptin, and proinflammatory cytokines. Lower limb arterial complications in CS are common and significantly impact morbidity and mortality. Furthermore, CS, in combination with DM, is likely to cause more diffuse vascular disease that predominantly affects distal arterial beds. In conclusion, CS promotes atherosclerosis, including peripheral artery disease, by causing functional and morphological deterioration of the arterial vessel wall and increasing the presence of classical risk factors of atherosclerosis.

Nilotinib-induced vasculopathy: identification of vascular endothelial cells as a primary target site.

The BCR/ABL1 inhibitor Nilotinib is increasingly used to treat patients with chronic myeloid leukemia (CML). Although otherwise well-tolerated, Nilotinib has been associated with the occurrence of progressive arterial occlusive disease (AOD). Our objective was to determine the exact frequency of AOD and examine in vitro and in vivo effects of Nilotinib and Imatinib on endothelial cells to explain AOD-development. In contrast to Imatinib, Nilotinib was found to upregulate pro-atherogenic adhesion-proteins (ICAM-1, E-selectin, VCAM-1) on human endothelial cells. Nilotinib also suppressed endothelial cell proliferation, migration and tube-formation and bound to a distinct set of target-kinases, relevant to angiogenesis and atherosclerosis, including angiopoietin receptor-1 TEK, ABL-2, JAK1 and MAP-kinases. Nilotinib and siRNA against ABL-2 also suppressed KDR expression. In addition, Nilotinib augmented atherosclerosis in ApoE-/- mice and blocked reperfusion and angiogenesis in a hindlimb-ischemia model of arterial occlusion, whereas Imatinib showed no comparable effects. Clinically overt AOD-events were found to accumulate over time in Nilotinib-treated patients. After a median observation-time of 2.0 years, the AOD-frequency was higher in these patients (29.4%) compared to risk factor- and age-matched controls (<5%). Together, Nilotinib exerts direct pro-atherogenic and anti-angiogenic effects on vascular endothelial cells, which may contribute to development of AOD in patients with CML.

Chronic complications of venous thromboembolism.

Venous thromboembolism (VTE) is a common disease (~700 per 100 000) that is associated with significant risk of recurrence, chronic complications, and substantial mortality, with reported death rates of up to 40% at 10 years. The development of novel anticoagulants has revolutionized the treatment of acute VTE, while strategies for prevention and treatment of chronic complications still seek for such a landmark change. Impaired thrombus resolution is the common denominator behind VTE complications, which are postthrombotic syndrome (PTS) and chronic thromboembolic pulmonary hypertension (CTEPH). PTS and CTEPH are associated with substantial morbidity and high healthcare expenses. While PTS occurs in up to 50% of patients after symptomatic deep vein thrombosis, only a small and poorly defined number of patients are diagnosed with CTEPH after pulmonary embolism. This review is a comprehensive summary of VTE-related chronic complications, their epidemiology, diagnosis, and treatment.

Glucose-lowering therapy in type 2 diabetes. New hope after the EMPA-REG outcome trial.

Prevention of cardiovascular morbidity and mortality remains the key factor in the treatment of type 2 diabetes (T2DM). In the early phase of T2DM, multifactorial intervention is mandatory and glucose levels should be near normal, in particular in younger patients presenting with the highest cardiovascular risk. Anti-diabetic drugs without any risk for hypoglycaemia should be preferred in order to reduce clinical inertia and increase the long-term adherence to the treatment. In patients already presenting with cardiovascular disease, the best outcome may be expected with the triple oral therapy of metformin, pioglitazone, and empagliflozin, although a controlled prospective study versus insulin therapy is needed to confirm the expectation.

Secreted Frizzled-Related Protein 4 (SFRP4) is Elevated in Patients with Diabetes Mellitus.

Recently, SFRP4 was identified as a molecular link between islet inflammation and defective insulin secretion. Gene co-expression analysis detected a molecule associated with type 2 diabetes mellitus (T2D), elevated HbA1c, and reduced insulin secretion in mice as well as in a pilot sample of humans. To our knowledge SFRP4 has never been investigated in patients with different types of diabetes. We included 179 patients: 46 with type 1 diabetes (T1D), 30 age matched healthy controls for patients with T1D (CO-T1D), 55 with T2D, 37 with latent autoimmune diabetes of the adult (LADA) and 30 healthy controls (CO) for patients with T2D and LADA. Apart from anthropometric data, lipids and renal parameters were assessed. SFRP4 levels were measured by a commercial ELISA. Patients with diabetes had significant higher SFRP4 levels than CO: T2D vs. CO: 37.1±26.7 vs. 8.8±3.0 ng/ml, p<0.001; LADA vs. CO: 15.6±6.2 vs. 8.7±3.0 ng/ml, p<0.001; T1D vs. CO-T1D: 24.6±17.9 vs. 16.9±4.5 ng/ml, p=0.011. SFRP4 levels were correlated with age, BMI, HbA1c, HDL-cholesterol, and triglycerides. A multivariate model revealed HDL-cholesterol, triglycerides and BMI as predictors for SFRP4. This is the first study demonstrating that SFRP4 is significantly increased in patients with different types of diabetes suggesting that this protein is generally involved in islet dysfunction and potentially subclinical inflammation irrespective of type of diabetes.

Decrease in microvesicle-associated tissue factor activity in morbidly obese patients after bariatric surgery.

BACKGROUND: Tissue factor (TF) is the main in vivo initiator of the blood coagulation cascade. Active circulating TF was detected on small, negatively charged membrane vesicles, the so-called microvesicles (MVs), which are released upon cell activation and apoptosis from a variety of cells. Increased coagulation activation was found in morbidly obese patients, and elevated levels of TF-bearing MVs may contribute to the prothrombotic state in these patients. AIM: To determine MV-associated TF activity levels in morbidly obese patients before and after weight loss due to bariatric surgery. METHODS: MV-TF activity was measured with a factor Xa generation assay in morbidly obese patients before and 2 years after bariatric surgery. In addition, clinical parameters were determined. RESULTS: Seventy-four morbidly obese patients (mean age: 42 (±11) years; 61 females) were included in this study. After bariatric surgery, the body mass index decreased from (median, 25-75th percentile) 45.5 (42.3-50.2) to 30.5 (28.0-34.4 kg m(-2); P<0.001), and a significant improvement in metabolic parameters was observed. Preoperative MV-TF activity correlated with C-reactive protein levels (r=0.3; P=0.02). Postoperatively, the mean MV-TF activity decreased significantly from 0.20 pg ml(-1) (0.18-0.47) to 0.02 (0.00-0.28; P<0.01). CONCLUSION: We could demonstrate a significant decrease in MV-TF activity after weight loss in morbidly obese patients. Decreased MV-TF activity might contribute to an improved coagulation profile in these patients after weight loss.

[Current treatment of type 2 diabetes]. / Aktuelle Therapie des Typ-2-Diabetes.

Type 2 diabetes is a complex metabolic disease associated with a high risk of vascular disease and certain entities of cancer. An early starting multifactorial intervention is mandatory in order to improve the prognosis of the patients. Of highest priority is the lowering of LDL-cholesterol (Target value < 100 mg/dl or < 70 mg/dl when vascular complications are present) and of the very often increased blood pressure values (target values 130-135/80 mm Hg). A successful blood glucose lowering therapy is often only possible when antidiabetic drugs are used in combination. The antidiabetic therapy has to be individualized concerning the HbA1target value and the selection of the antidiabetic drugs in relation to age of the patients and presence or absence of co-morbidities. Severe events of hypoglycemia should be avoided, since these are associated with an increased cardiovascular risk and mortality.

The soluble form of the receptor of advanced glycation endproducts increases after bariatric surgery in morbid obesity.

OBJECTIVE: The increased cardiovascular (CV) disease risk in patients with morbid obesity (MO) cannot be fully explained by traditional CV risk factors. Activation of the receptor of Advanced Glycation Endproducts (RAGE) leads to inflammation via the NF κß (nuclear factor κß) pathway. The soluble form of RAGE (sRAGE), which is present in plasma, can bind to ligands of RAGE and avoids interaction of RAGE with proinflammatory ligands. We investigated sRAGE levels in patients with MO and compared them with healthy lean controls (CO), before and after bariatric surgery. DESIGN: We conducted a cross-sectional study and a 24-month longitudinal study. SUBJECTS: We included 85 patients (mean age: 41 ± 12 years; mean body mass index (BMI): 45.4 ± 7.9 kg m(-2)) with MO in comparison with 40 CO (mean age: 42 ± 13 years; mean BMI: 26.0 ± 5.5 kg m(-2)). All patients were investigated before and 2 years after bariatric surgery. Apart from weight and CV risk markers (blood pressure, lipids), a glucose tolerance test (75 g), renal and inflammation parameters were assessed. sRAGE levels were assessed by a commercial ELISA. To investigate the associations of the observed reductions of values, delta (Δ) of parameters were calculated. RESULTS: Patients with MO had significant lower sRAGE levels than CO: 1010 ± 514 vs 1501 ± 674 pg ml(-1); P<0.001. In the longitudinal study, sRAGE levels increased significantly after bariatric surgery from 1010 ± 514 to 1261 ± 710 pg ml(-1); P=0.008. In the correlation analysis, ΔsRAGE levels were associated with Δ1-h and Δ2-h postprandial glucose, Δfasting insulin, Δ2-h postprandial insulin, ΔHOMA (homeostatic model assessment)-insulin resistance (ΔHOMA-IR), Δγ-glutamyl transferase and Δtriglycerides. In a multivariate model, Δ1-h and Δ2-h postprandial glucose, Δ2-h postprandial insulin and ΔHOMA-IR predicted ΔsRAGE. CONCLUSION: Patients with MO have significantly lower sRAGE levels compared with non-obese CO, but sRAGE levels increase significantly after weight loss induced by bariatric surgery. As high sRAGE levels inhibit the activation of inflammatory pathways, our results might help understand the beneficial effects of bariatric surgery regarding CV morbidity and mortality.

Microvascular autoregulation in children and adolescents with type 1 diabetes mellitus.

AIMS/HYPOTHESIS: Deterioration of microvascular function may have an early onset in individuals with type 1 diabetes mellitus. We hypothesised that microvascular autoregulation is impaired in children with type 1 diabetes and can be detected non-invasively by postocclusive reactive hyperaemia (PORH). METHODS: Microvascular autoregulation was assessed in 58 children with type 1 diabetes and 58 age- and sex-matched healthy controls by PORH using laser Doppler fluxmetry. Baseline perfusion, biological zero (defined as a 'no flow' laser Doppler signal during suprasystolic occlusion), peak perfusion following occlusion, time to peak and recovery time (time until baseline perfusion is resumed) were recorded and compared between the groups. RESULTS: Peak perfusion was higher in children with type 1 diabetes than in healthy controls (1.7 ± 0.93 AU [arbitrary units] vs 1.29 ± 0.46 AU; p = 0.004), and biological zero was lower in children with type 1 diabetes vs controls (0.14 ± 0.04 AU vs 0.19 ± 0.04 AU; p < 0.0001). No differences were seen between the groups in baseline perfusion, time to peak during PORH and recovery time following PORH. CONCLUSIONS/INTERPRETATION: PORH reveals impaired microvascular autoregulation in children with type 1 diabetes. The higher peak perfusion might reflect a decline in the vasoconstrictive ability of arteriolar smooth muscle cells upstream of capillary beds in children with type 1 diabetes.

Which is the eligible patient to be treated with pioglitazone? The expert view.

Pioglitazone has an important role in the treatment of patients with Type 2 diabetes. The drug can help patients to achieve sustained glycemic control and may delay the requirement for insulin. Pioglitazone may provide benefits beyond its effects on glycemia, with data suggesting it may confer anti-atherosclerotic and cardioprotective properties. Attention should be given to possible side effects relating to class effects of TZD, and selection of appropriate patients to be prescribed pioglitazone will enable optimum benefits to be derived from pioglitazone treatment.

Thrombin generation in morbid obesity: significant reduction after weight loss.

BACKGROUND: Patients with morbid obesity (MO; body mass index > 40 kg m(-2)) suffer from an increased risk of cardiovascular disease, stroke, venous thromboembolism and all-cause mortality. OBJECTIVES: Because weight loss by bariatric surgery reduces cardiovascular and all-cause mortality, we hypothesized that the plasmatic clotting system might be involved in cardiovascular risk. PATIENTS/METHODS: Thirty-six MO patients [mean age 42 (+/-13) years; 29 female) were investigated before and 2 years after bariatric surgery. Thrombin generation was measured with a commercially available assay (Technothrombin-TGA,Technoclone). Metabolic parameters and parameters of the hemostatic system, such as tissue factor (TF), TF pathway inhibitor (TFPI), plasminogen activator inhibitor-1 (PAI-1) and prothrombinfragment 1.2 (F1.2), were determined. To investigate associations of changing parameters, deltas were calculated. RESULTS: Metabolic parameters improved with a mean weight loss of 41 (+/-19) kg. Postoperatively, the lag phase was significantly extended compared with preoperative values [median (25th-75th percentile), 7 (4-12) vs. 12 (7-19) min, P = 0.005]. Peak thrombin decreased after weight loss from 345 (232-455) to 282 (111-388) nm (P = 0.015) and the area under the curve from 3962 (3432-5023) to 3227 (2202-4030) nm thrombin (P < 0.001). TF, PAI-1 and F1.2 significantly decreased after weight loss. Analyses of the deltas showed a significant correlation between peak thrombin and total cholesterol (r = 0.50), triglycerides (r = 0.46) and HbA1c (r = 0.55). Moreover, an inverse correlation was found between insulin resistance and the lag phase (r = -0.46). CONCLUSION: Thrombin generation, a marker of the overall coagulation potential, decreased significantly with weight reduction. This might, at least in part, explain the decreased risk of cardiovascular disease after bariatric surgery.

Serum concentrations of retinol-binding protein 4 in women with and without gestational diabetes.

AIMS/HYPOTHESIS: Pregnancy is characterised by temporarily increased insulin resistance. Gestational diabetes occurs when pancreatic beta cell function is unable to compensate for this insulin resistance. Retinol-binding protein 4 (RBP4) could be related to insulin resistance. We hypothesised that RBP4 is elevated in gestational diabetes. METHODS: Serum RBP4, transthyretin and retinol were cross-sectionally measured in 42 women with gestational diabetes and 45 pregnant controls. Of these, 20 women with and 22 without gestational diabetes were included in an additional longitudinal study. RBP4 was determined by enzyme immunometric assay (EIA) and western blot. RESULTS: Women with gestational diabetes had lower RBP4 EIA and western blot levels than controls (median 6.8 [interquartile range, 3.9-14.3] vs 11.3 [7.8-19.9] microg/ml, p < 0.001 and 25.1 [21.7-29.6] vs 26.6 [23.5-32.2] microg/ml, p = 0.026). Transthyretin and the RBP4:transthyretin molar ratio were comparable between the groups. Serum retinol was lower (p < 0.001) and the RBP4 Western blot level: retinol molar ratio was higher in women with gestational diabetes (p = 0.044). RBP4 was not associated with the glucose or homeostasis model assessment of insulin resistance (HOMA-IR), but in gestational diabetes the RBP4:retinol molar ratio correlated with blood glucose and negatively with 2 h post-load insulin. The RBP4:transthyretin ratio correlated with HOMA-IR and fasting insulin in controls. In women with gestational diabetes RBP4 EIA and western blot levels increased after delivery. Retinol increased in both groups, while transthyretin and the RBP4:transthyretin ratio were not altered after parturition. CONCLUSIONS/INTERPRETATION: RBP4 measured by two different techniques is not elevated, but the RBP4:retinol molar ratio is higher and correlates with fasting blood glucose in women with gestational diabetes. Thus, the RBP4:retinol ratio and the RBP4:transthyretin ratio are more informative than RBP4 levels alone when assessing insulin-glucose homeostasis during pregnancy.

CD203c is overexpressed on neoplastic mast cells in systemic mastocytosis and is upregulated upon IgE receptor cross-linking.

The ectoenzyme E-NPP3 (CD203c) has recently been identified as a novel activation-linked cell surface antigen on basophils. In the present study, we examined expression of CD203c on normal mast cells (MC)and bone marrow (bm) MC derived from 85 patients with systemic mastocytosis (SM), including cases with indolent SM (ISM, n=72), SM with associated clonal hematologic non-MC-lineage disease (SM-AHNMD, n=6), aggressive SM (ASM, n=3), and mast cell leukemia (MCL, n=4). Surface expression of CD203c was analyzed by multicolor flow cytometry. In patients with SM, bm MC expressed significantly higher amounts of CD203c compared to normal bm MC (median MFI in controls: 260 versus median MFI in SM: 516, p<0.05). Slightly lower amounts of CD203c were detected on MC in SM-AHNMD and ASM compared to ISM. To demonstrate CD203c expression in MC at the mRNA level, neoplastic MC were highly enriched by cell sorting, and were found to express CD203c mRNA in RT-PCR analysis. Cross-linking of the IgE receptor on MC resulted in a substantial upregulation of CD203c, whereas the KIT-ligand stem cell factor (SCF) showed no significant effects. In conclusion, CD203c is a novel activation-linked surface antigen on MC that is upregulated in response to IgE receptor cross-linking and is overexpressed on neoplastic MC in patients with SM.

Interleukin-3 promotes the expression of E-NPP3/CD203C on human blood basophils in healthy subjects and in patients with birch pollen allergy.

We recently identified the ectoenzyme CD203c as a novel basophil activation antigen that is upregulated in response to FcepsilonRI cross-linkage. We investigated the effects of various interleukins (ILs) on expression of CD203c on blood basophils using an antibody against CD203c and flow cytometry. Of all cytokines tested, only IL-3 was found to upregulate expression of CD203c on basophils above baseline levels. The effects of IL-3 were dose- and time-dependent (EC(50): 0.1-1 ng/ml) without differences observed between healthy and allergic donors. Whereas anti-IgE induced maximum upregulation of CD203c within 15 minutes, the IL-3-induced upregulation showed a maximum after 180 minutes. IgE-receptor cross-linking resulted in enhanced expression of both CD63 and CD203c, whereas IL-3 enhanced the levels of CD203c without promoting expression of CD63. The IL-3-induced upregulation of CD203c was also observed in highly enriched basophils and was counteracted by a blocking antibody against the alpha chain of the IL-3 receptor (CD123). The IL-3-induced upregulation of CD203c was also found to depend on the presence of calcium. To analyze signaling pathways involved in IL-3-induced upregulation of CD203c, pharmacologic inhibitors were applied. The PI3-kinase inhibitors, wortmannin and LY294002 counteracted the IL-3-induced expression of CD203c, whereas MEK- and PKC inhibitors showed no effects. In conclusion, IL-3 upregulates expression of CD203c on basophils through a specific receptor and via a PI3-kinase-dependent signaling-pathway. Compared to FcepsilonRI-mediated cell activation, IL-3-induced upregulation of CD203c is a late(r) event and is not accompanied by upregulation of CD63.

Expression of the target receptor CD33 in CD34+/CD38-/CD123+ AML stem cells.

BACKGROUND: CD33 (Siglec-3) is becoming increasingly important as a target of antibody-mediated therapy in acute myeloid leukaemia (AML). In normal myelopoiesis, expression of CD33 is restricted to advanced stages of differentiation, whereas primitive stem cells do not express CD33. In the present study, we asked whether leukaemic stem cells in patients with AML express CD33. MATERIALS AND METHODS: A multicolour-staining technique was applied in 11 patients with AML, and leukaemic progenitors defined as CD34(+)/CD38(-)/CD123(+) cells. AML stem cells were purified by cell sorting and were examined for expression of CD33 mRNA by reverse transcriptase-polymerase chain reaction (RT-PCR). RESULTS: In all patients in whom the majority of myeloblasts expressed CD33 (n = 8), AML progenitors reacted with the CD33 antibody P67.6. Repopulation experiments utilizing irradiated NOD/SCID mice confirmed that AML stem cells in these patients reside within the CD33(+) subpopulation of the leukaemic clone. Moreover, highly purified AML stem cells (> 98% purity) from patients with CD33(+) AML were found to express CD33 mRNA in RT-PCR analyses. CD33 was neither detectable on CD34(+)/CD38(-) cells in normal bone marrow nor on leukaemic stem cells in patients with CD33-negative AML. CONCLUSIONS: Leukaemic stem cells in patients with CD33(+) AML express CD33. This observation is in favour of novel treatment concepts employing CD33-targeting antibodies in AML.

Soluble CD40L in patients with morbid obesity: significant reduction after bariatric surgery.

BACKGROUND: Morbid obesity is associated with increased cardiovascular morbidity and mortality. Recent studies suggest that soluble CD40 Ligand (sCD40L) may play a pathogenetic role in atherothrombotic complications in cardiovascular disease as well as in inflammation and thrombosis. As morbid obesity is closely associated with chronic inflammation and insulin resistance (IR), it was of interest to study sCD40L in patients with morbid obesity before and after massive weight loss induced by bariatric surgery. PATIENTS AND METHODS: A total of 34 patients (mean age 40 +/- 12 years) with morbid obesity were studied before and 27.2 months after bariatric surgery. High sensitivity assays were used to measure concentrations of fasting sCD40L, monocyte-chemoattractant-protein-1 (MCP-1) and high-sensitive C-reactive protein (hsCRP). To investigate the associations of concentration changes of the parameters studied, differences between pre- and post-operative data were assessed and tested by univariate and multivariate linear regression analysis. RESULTS: After a mean weight loss of 33.1 +/- 18.4 kg, circulating sCD40L decreased significantly from (3.7 +/- 1.5) ng mL(-1) to (2.2 +/- 0.7) ng mL(-1), (P < 0.001). The decline in sCD40L after weight loss correlated significantly with the decrease in fasting insulin, 2-h insulin, HOMA insulin resistance (HOMA-IR), triglycerides, and the inflammatory biomarkers MCP-1 and hsCRP. CONCLUSIONS: We have shown a marked decrease in circulating sCD40L in association with an improvement of both insulin resistance and chronic inflammation in morbidly obese patients after bariatric surgery. As high sCD40L was shown to predict cardiovascular death and myocardial infarction in several prospective studies, the observed marked lowering of sCD40L might be of clinical relevance in morbidly obese patients.

No effect of homocysteine-lowering therapy on vascular inflammation and haemostasis in peripheral arterial occlusive disease.

BACKGROUND: Although peripheral arterial occlusive disease (PAOD) is significantly associated with elevated homocysteine levels, the clinical relevance of hyperhomocysteinaemia for the prevention and progression of PAOD is still unknown. MATERIALS AND METHODS: A total of 65 patients suffering from symptomatic PAOD with elevated homocysteine levels were randomized onto placebo or B-vitamins (50 mg thiaminhydrochlorid, 50 mg pyridoxine, and 0.05 mg cyanocobalamin), plus 5 mg folic acid daily for 6 weeks. Serum levels of folic acid, vitamin B12, creatinine, ultra-sensitive C-reactive protein (usCRP), interleukin (IL)-6, IL-8, IL-18, monocyte-chemo-attractant-protein-1 (MCP-1) and plasma levels of homocysteine, tissue factor (TF) and tissue factor pathway inhibitor (TFPI) were determined on the 1st day and 42nd day. Primary outcome was reduction of homocysteine, secondary outcomes were reduction of usCRP, IL-6, IL-8, Il-18, MCP-1, TF and TFPI. RESULTS: The mean reduction of homocysteine concentration was 33% (95%CI 33.36-55.76, or 18.9+/-5.4 micromol L-1-12.6+/-2.8 micromol L-1, P=0) in the B-vitamin group compared with 1% in the placebo group. Folic acid (P=0) and vitamin B12 (P=0) increased significantly in the verum group, but both remained unchanged in the control group. No treatment effect of lowering of homocysteine on any markers of haemostasis (TF, TFPI) or inflammation (usCRP, IL-6, IL-8, IL-18 and MCP-1) was observed. CONCLUSION: Although homocysteine is associated with vascular disease risk in the general population and in particular with PAOD, marked lowering of homocysteine concentrations by folic acid and B-vitamin supplementation does not influence inflammatory responses involving usCRP, IL-6, IL-8, IL-18 and MCP-1, nor tissue factor. These results provide evidence against a major effect of hyperhomocysteinaemia on vascular chronic inflammation or coagulation in patients with symptomatic peripheral arterial occlusive disease.

Evaluation of neoplastic human mast cells by tryptase-immunoelectron microscopy.

AIMS: To analyse and characterize the ultrastructural morphology of normal tissue mast cells (MC) and neoplastic bone marrow MC. METHODS: We have examined the ultrastructure and cytomorphological features of MC derived from cord blood cells, neoplastic bone marrow MC in patients with systemic mastocytosis (SM, n = 4), myelomastocytic leukaemia (MML, n = 2), mast cell leukaemia (MCL, n = 2) and tryptase-positive acute myeloid leukaemia (AML, n = 4). RESULTS: Based on their ultrastructure and morphology, four distinct cell types could be delineated: (i) mature well-granulated tissue MC exhibiting a round central nucleus; (ii) atypical MC type I with oval nuclei, hypogranulated cytoplasm, and prominent surface projections; (iii) immature atypical MC with bi- or polylobed nuclei (atypical MC type II = promastocytes); and (iv) metachromatic blasts. Type I atypical MC were detected in a patient with indolent SM, whereas type II MC and metachromatic blasts were primarily found in MML, MCL and tryptase-positive AML. In all samples examined, the identity of MC could be reconfirmed by immunoelectron microscopy, irrespective of the stage of cell maturation or the disease variant, all types of MC contained tryptase in their cytoplasmic granules. CONCLUSION: Immunoelectron microscopy may be a helpful approach in confirming the identity of neoplastic MC in myeloid neoplasms.

Effects of various statins on cytokine-dependent growth and IgE-dependent release of histamine in human mast cells.

BACKGROUND: Statins are inhibitors of hydroxymethylglutaryl coenzyme A (HMG CoA) reductase, a key enzyme in mevalonic acid (MVA)-dependent signaling. Recent data suggest that statins exhibit profound inhibitory effects on growth and function of various immune cells. In the present study, we examined the in vitro effects of five different statins on primary human mast cells (MCs), MC progenitors, and the human MC line HMC-1. METHODS: Histamine release experiments were conducted on isolated MCs using statins and an anti-immunoglobulin E (IgE) antibody. Culture experiments were performed with stem cell factor (SCF) and interleukin (IL)-6, and cord blood-derived progenitors. RESULTS: Preincubation of primary lung MCs with cerivastatin or atorvastatin (1-50 microM) for 24 h resulted in inhibition of anti-IgE-induced release of histamine. The effects of both statins were dose-dependent. Moreover, both statins, and to a lesser degree lovastatin, were found to inhibit the SCF-induced differentiation of MCs from their progenitors. The other statins tested (simvastatin, pravastatin) did not affect mediator release or growth of MCs. CONCLUSIONS: Cerivastatin and atorvastatin act as inhibitors of growth and function of human MCs.