Endothelial Dysfunction and Pentraxin-3 in Clinically Stable Adult Asthma Patients.

BACKGROUND AND OBJECTIVE: Asthma is associated with low-grade systemic inflammation, prothrombotic state, and premature atherosclerosis. Objective: To evaluate the relationships between asthma, inflammatory biomarkers, and parameters of endothelial dysfunction. MATERIAL AND METHODS: We analyzed flow-mediated dilatation (FMD) of the brachial artery and intima-media thickness (IMT) of the common carotid artery using ultrasound in 92 clinically stable adult asthmatics and 62 well-matched controls. We also measured blood levels of selected inflammatory and asthma-specific biomarkers, including interleukin (IL) 4, IL-5, IL-6, IL-10, IL-12 (p70), IL-17A, IL-23, and interferon γ, as well as a disintegrin and metalloproteinase domain-containing protein 33 (ADAM-33). In addition, we assessed endothelial damage using 2 laboratory biomarkers: circulating von Willebrand factor (vWF) and pentraxin-3. We analyzed relationships between the study variables and asthma severity, lung function abnormalities, airway remodeling indices on computed tomography, and transthoracic echocardiography parameters. RESULTS: Asthmatics had higher IL-6, IL-10, and ADAM-33 levels. They were also characterized by 23% lower FMD% and 15% thicker IMT, as compared with controls (P<.001, both). In asthma, vWF was related to age (ß=0.28 [95%CI, 0.15-0.41]) and remained inversely associated with FEV1 (ß=-0.2 [95%CI, -0.05 to -0.35]). Surprisingly, a negative correlation was revealed between vWF and pentraxin-3 (ß=-0.17 [95%CI, -0.3 to -0.04]). Pentraxin-3 remained positively associated with airway remodeling indices. CONCLUSIONS: Asthma is characterized by endothelial dysfunction associated with airway obstruction. The biological role of pentraxin-3 is unknown, although our data suggest a protective role against endothelial damage and atherosclerosis.

Impaired cardiovascular autonomic nervous system function in patients with Churg-Strauss syndrome.

OBJECTIVES: Although peripheral nervous system involvement in patients with Churg-Strauss syndrome (CSS) has been described, little is known about its autonomic part. Autonomic nervous system (ANS) function can be assessed by studying heart rate variability (HRV) and a decrease in the spectrum of HRV correlates with ANS impairment. METHODS: Out of 24 CSS patients we chose 12 (four males, eight females, aged 40 ± 8.3 years) in disease remission and without cardiac involvement. Twelve age- and sex-matched healthy volunteers served as a control group. All underwent 24-h electrocardiogram (ECG) Holter recordings. HRV was calculated from 1-h segments, including: total power (TP), ultra-low frequency (ULF), very low frequency (VLF), low frequency (LF), and high frequency (HF) powers as well as normalized LF (LF%) and HF (HF%) powers and the LF to HF power ratio (LF/HF). RESULTS: The CSS patients showed decreased HRV parameters in the 1-h domains: TP (2038 vs. 3622 ms(2), p = 0.001), HF (561 vs. 1574 ms(2), p < 0.001), LF (672 vs. 1050 ms(2), p < 0.01), and VLF (544 vs. 738 ms(2), p = 0.016). However, LF% and LF/HF ratio were markedly higher in CSS patients than in controls (53.4% vs. 39%, p < 0.001 and 1.1 vs. 0.64, p < 0.001), whereas HF% was lower in CSS than in controls (46.6% vs. 61%, p < 0.001). These results were independent of duration of the disease, eosinophil count, corticosteroids, or peripheral nerve involvement in the past. CONCLUSIONS: The CSS patients show impaired HRV parameters, indicating parasympathetic ANS dysfunction in addition to peripheral nervous system involvement.

Pharmacological inhibition of leukotriene biosynthesis: effects on the heart conductance.

Leukotrienes are lipid mediators produced via 5-lipooxygenase pathway of arachidonic acid. At least two cysteinyl-leukotrienes receptors are highly expressed in the heart, including the conduction system. Coronary angiography or angioplasty is accompanied by release of cysteinyl leukotrienes into coronary circulation and into urine. We tested the hypothesis that inhibition of leukotrienes biosynthesis would affect the conductance system function. In a double-blind placebo controlled study, patients with stable angina undergoing elective coronary catheterization or angioplasty were randomly assigned to 48 hrs treatment with a 5-lipoxgenase inhibitor (n=54) or placebo (n=49). ECG Holter recording was carried out for 24 hrs before and after the procedure and urinary leukotriene E(4) measurements were done. Inhibition of 5-lipoxygenase caused 26% reduction of urinary leukotriene E(4), associated with: 1) decrease in heart rate by about 7%, 2) enhanced heart rate variability; 3) protection against depressions in atrioventricular conductance and ventricular repolarization induced by the procedure. No effects on either arrhythmias, or ECG patterns of ischemia were noted. We conclude that pharmacological inhibition of 5-lipoxygenase, shortly before percutaneous coronary intervention, reveals specific actions of leukotrienes on the heart rhythm. Inhibitors of 5-lipoxygenase might be of interest as a novel class of cardiac drugs affecting the conductive system.

Prediction of the excessive perioperative bleeding in patients undergoing coronary artery bypass grafting: role of aspirin and platelet glycoprotein IIIa polymorphism.

OBJECTIVE: The presence of the glycoprotein IIIa allele PlA2 is associated with enhanced thrombin formation and an impaired antithrombotic action of aspirin, which could favor coronary thrombosis. We wondered whether PlA1/A2 genetic polymorphism could affect the postoperative bleeding in patients undergoing coronary artery bypass grafting. We also aimed to assess the effects of aspirin pretreatment and to ascertain the value of platelet function studies as predictors of postoperative bleeding. METHODS: In a randomized, double-blind study, patients undergoing coronary artery bypass grafting were pretreated with a 150-mg dose of aspirin orally 12 and 3 hours before surgery (n = 51, 41 elective) or with placebo (n = 51, 43 elective). The hemostasis was monitored by Simplate (bioMérieux, Inc, Durham, NC) bleeding time and capillary closure time (platelet function analyzer PFA 100; Sysmex UK Ltd, Milton Keynes, United Kingdom). Postoperative bleeding and blood products transfusions were recorded. The glycoprotein IIIa polymorphism was analyzed. RESULTS: Bleeding was significantly greater in PlA1 homozygotes from control group. Blood loss was significantly greater (by 25%) in aspirin group. The volume of blood products transfusions in aspirin patients was significantly larger (by 137%). When subjects were stratified accordingly to blood platelet glycoprotein IIb/IIIa genotype, in the aspirin group PlA2 carriers had greater blood loss than PlA1 homozygotes (1858 +/- 932 mL vs 1216 +/- 525 mL, P < .05). CONCLUSION: PlA1 homozygotes normally had a greater risk of perioperative bleeding. Capillary closure time had no advantage relative to Simplate bleeding time in predicting postoperative blood loss. Aspirin pretreatment revealed no beneficial effects and resulted in increased postoperative bleeding and requirement for blood product transfusions after coronary artery bypass grafting in patients with stable angina. It was most unfavorable for PlA2 carriers.

Mutation A1298C of methylenetetrahydrofolate reductase: risk for early coronary disease not associated with hyperhomocysteinemia.

Diminished activity of 5,10 methylenetetrahydrofolate reductase (MTHFR), a regulatory enzyme of homocysteine metabolism, may predispose to coronary artery disease (CAD). In a case-control study we determined the prevalence of two common MTHFR polymorphisms, C677T and A1298C, in 161 male patients under the age of 50 years with angiographically documented CAD and compared it to that in 211 healthy controls. Genotyping was also performed in a random population sample, consisting of 149 men and 121 women at an average age of 40 years. The studied group had classic risk factors of atherosclerosis but did not differ in fasting plasma homocysteine, folic acid, and vitamin B12 levels in either the control group or population sample. The frequency of the 1298C allele was significantly higher in CAD (0.304) than in controls (0.199) or the population sample (0.235). Allele 1298C showed a significant association with early-onset CAD both in homozygotes and in heterozygous carriers. These findings were further supported by comparisons with the population sample. Homozygosity for allele 677T showed a tendency to associate with CAD. Allele 1298C of MTHFR is associated with early-onset CAD (carriers- RR = 1.71, 95% CI: 1.13-2.59; homozygotes- RR = 3.09, 95% CI: 1.36-7.02), even when blood homocysteine levels are not elevated.

[Fabry's disease--late diagnosis in men with chronic nephropathy and skin changes]. / Choroba Fabry'ego--pózne rozpoznanie u mezczyzny z przewlekla nefropatia i zmianami skórnymi.

We report a case of Fabry's disease, diagnosed in a 39-year-old patient treated for 4 years because of glomerulonephritis. The disease manifested itself by the presence of typical petechiae-like skin lesions in the bathing trunk area (angiokeratoma), eye changes, paresthesia, and--in additional investigations--mild proteinuria, lowered creatinine clearance, along with changes in the central nervous system. A biopsy of the kidney revealed the presence of foamy cells in all glomeruli, and in electron microscopy multilamellar bodies (zebra bodies). The diagnose of the disease was confirmed by a marked decrease in leucocyte alpha-galactosidase activity. An early diagnosis of non-inflammatory character of Fabry's disease allows to avoid an unnecessary immunosuppressive treatment.

Efficacy of MK-991 (L-743,872), a semisynthetic pneumocandin, in murine models of Pneumocystis carinii.

In addition to its potent efficacy in animal models against Candida sp., Aspergillus fumigatus, and Histoplasma capsulatum, the clinical candidate pneumocandin MK-991 (formerly L-743,872) was also extremely potent against Pneumocystis carinii in models of immune-compromised animals. MK-991 was approximately 14 times more potent than the original natural product lead, pneumocandin B0. The 90% effective dose (ED90) of MK-991 for cyst clearance in the rat model for pneumocystis was 0.011 mg/kg of body weight when delivered parenterally for 4 days twice a day (b.i.d.). In a mouse model, under the same experimental parameters, the ED90 was 0.02 mg/kg. MK-991 was also effective orally, with an ED90 for cyst clearance of 2.2 mg/kg against acute infection in rats (b.i.d. for 4 days). Complete prevention of P. carinii development was achieved in immunocompromised mice at a daily oral dose of 2.25 mg/kg. As reported previously for other pneumocandins and echinocandins, MK-991 selectively prevented the development of P. carinii cysts. When used as a prophylactic agent, neither stage of the organism appeared in the lungs of animals. In response to an acute infection, cysts were eliminated rapidly, while trophozoite forms persisted. Despite good efficacy as an oral agent in murine models, the low oral absorption of this class may limit the use of MK-991 to parenteral therapy.

In vitro preclinical evaluation studies with the echinocandin antifungal MK-0991 (L-743,872).

The echinocandin MK-0991, formerly L-743,872, is a water-soluble lipopeptide that has been demonstrated in preclinical studies to have potent activity against Candida spp., Aspergillus fumigatus, and Pneumocystis carinii. An extensive in vitro biological evaluation of MK-0991 was performed to better define the potential activities of this novel compound. Susceptibility testing with MK-0991 against approximately 200 clinical isolates of Candida, Cryptococcus neoformans, and Aspergillus isolates was conducted to determine MICs and minimum fungicidal concentrations MF(s). The MFC at which 90% of isolates are inhibited for 40 C. albicans clinical isolates was 0.5 microg/ml. Susceptibility testing with panels of antifungal agent-resistant species of Candida and C. neoformans isolates indicated that the MK-0991 MFCs for these isolates are comparable to those obtained for susceptible isolates. Growth kinetic studies of MK-0991 against Candida albicans and Candida tropicalis isolates showed that the compound exhibited fungicidal activity (i.e., a 99% reduction in viability) within 3 to 7 h at concentrations ranging from 0.06 to 1 microg/ml (0.25 to 4 times the MIC). Drug combination studies with MK-0991 plus amphotericin B found that this combination was not antagonistic against C. albicans, C. neoformans, or A. fumigatus in vitro. Studies with 0 to 50% pooled human or mouse serum established that fungal susceptibility to MK-0991 was not significantly influenced by the presence of human or mouse serum. Results from resistance induction studies suggested that the susceptibility of C. albicans was not altered by repeated exposure (40 passages) to MK-0991. Erythrocyte hemolysis studies with MK-0991 with washed and unwashed human or mouse erythrocytes indicated minimal hemolytic potential with this compound. These favorable results of preclinical studies support further studies with MK-0991 with humans.

Evaluation of the echinocandin antifungal MK-0991 (L-743,872): efficacies in mouse models of disseminated aspergillosis, candidiasis, and cryptococcosis.

The in vivo activity of the Merck antifungal echinocandin drug candidate MK-0991 (L-743,872) was evaluated in mouse models of disseminated candidiasis, aspergillosis, and cryptococcosis. The echinocandins are potent inhibitors of 1,3-beta-D-glucan synthase. Two models of disseminated candidiasis were used. In a Candida albicans mouse survival model with both DBA/2N and CD-1 mice, estimates of the 50% effective doses (ED50s) of MK-0991 were 0.04 and 0.10 mg/kg of body weight/dose at 21 days after challenge, respectively. In a C. albicans target organ assay (TOA) with DBA/2N mice, MK-0991 at levels of > or =0.09 mg/kg/dose significantly reduced the numbers of C. albicans CFU/g of kidneys compared to the numbers in the kidneys of control mice from 1 to 28 days after challenge. Even when given as a single intraperitoneal dose either 30 min or 24 h after challenge, MK-0991 was effective and significantly reduced the numbers of C. albicans CFU/g of kidney compared to those in the controls. MK-0991 was >300-fold less active when it was administered orally than when it was administered parenterally. MK-0991 was efficacious in mouse TOAs against other C. albicans strains and Candida species including Candida tropicalis, Candida (Torulopsis) glabrata, Candida lusitaniae, Candida parapsilosis, and Candida krusei. MK-0991 was ineffective against disseminated Cryptococcus neoformans infections. In the model of disseminated aspergillosis in mice, MK-0991 at doses of > or =0.02 mg/kg/dose significantly prolonged the survival of DBA/2N mice, with estimates of the ED50 and ED90 of MK-0991 being 0.03 and 0.12 mg/kg/dose, respectively, at 28 days after challenge. MK-0991 is a potent, parenterally administered therapeutic agent against disseminated candidiasis and aspergillosis that warrants further investigation in human clinical trials.

Preliminary animal pharmacokinetics of the parenteral antifungal agent MK-0991 (L-743,872).

MK-0991 (L-743,872) is a potent antifungal agent featuring long half-life pharmacokinetics. The pharmacokinetics of MK-0991 administered intravenously to mice, rats, rhesus monkeys, and chimpanzees is presented. Unique to MK-0991 is its consistent cross-species performance. The range of values for the pharmacokinetic parameters were as follows: clearance, 0.26 to 0.51 ml/min/kg; half-life, 5.2 to 7.6 h; and distributive volume, 0.11 to 0.27 liters/kg. The level of protein binding of MK-0991 was determined to be 96% in mouse and human serum. The compound exhibited high affinities for human serum albumin and at least two lipid components. The rationale for the selection of MK-0991 as a drug development candidate was based on its two- to threefold superior pharmacokinetic performance in chimpanzees over the performance of an otherwise equivalent analog, L-733,560. Once-daily dosing for MK-0991 is indicated by a graphical comparison of levels in the circulations of chimpanzees and mice. In a study of the pharmacokinetics of MK-0991 in mouse tissue, the organs were assayed following intraperitoneal administration. The area under the concentration-versus-time curves (AUC) segregated the tissues into three exposure categories relative to plasma. The tissues with greater exposure than that for plasma were liver (16 times), kidney (3 times), and large intestine (2 times). The exposure for small intestine, lung, and spleen were equivalent to that for plasma. Organs with lower levels of exposure were the heart (0.3 times that for plasma), thigh (0.2 times), and brain (0.06 times). Kinetically, drug was cleared more slowly from all tissues than from plasma, indicating that terminal-phase equilibrium had not been achieved by 24 h. Thus, some measure of accumulation is predicted for all tissues. Single daily doses of MK-0991 should provide adequate systemic levels of fungicidal activity as a result of its long half-life pharmacokinetics, wide distribution, and slowly accumulating concentrations in tissue.

Aerosol and parenteral pneumocandins are effective in a rat model of pulmonary aspergillosis.

The pneumocandins are semisynthetic analogs of echinocandin-like compounds that have shown efficacy in animal models of systemic candidiasis, disseminated aspergillosis, and pneumocystis pneumonia. However, the most common form of Aspergillus infection in susceptible patients is pulmonary aspergillosis, which was not directly tested in the mouse models used in the past. We have evaluated three pneumocandins, L-693,989, L-731,373, and L-733,560, in a rat model of pulmonary aspergillosis. Male Sprague-Dawley rats were treated for 2 weeks with cortisone and tetracycline and fed a low-protein diet before being inoculated via the trachea with 10(6) conidia of Aspergillus fumigatus H11-20. In the absence of drug treatment, the animals developed a progressive, rapidly fatal bronchopneumonia. All three pneumocandins at doses of 5 mg/kg (intraperitoneally [i.p.] every 12 h [q12h]) were effective in delaying mortality in this model. Survival at day 7 postinfection was 20% among controls (n = 10 for all groups), while it was 60, 80, and 90% in groups that were treated with L-693,989, L-731,373, and L-733,560, respectively. In another trial, survival at day 7 postinfection was 25% among controls (n = 8 for all groups); it was 87.5% in a group treated with amphotericin B (0.5 mg/kg i.p. q12h) and was 100% in a group treated with L-733,560 (0.625 mg/kg i.p. q12h). In a separate trial, aerosol L-693,989 administered 2 h before infection (5 mg/kg) delayed mortality. Eight of the 10 animals treated with aerosol L-693,989 survived for 7 days, whereas only 2 of 10 control animals survived. We conclude that the pneumocandins we tested were highly effective in an animal model of pulmonary aspergillosis.

New semisynthetic pneumocandins with improved efficacies against Pneumocystis carinii in the rat.

A new series of semisynthetic, water-soluble pneumocandin analogs has been found to be extremely potent against Pneumocystis carinii in an immunocompromised-rat model. These compounds are 5 to 10 times more potent than the parent natural product, pneumocandin B0 (L-688,786) (R. E. Schwartz et al., J. Antibiot. 45:1853-1866, 1992), and > 100 times more potent than cilofungin. One compound in particular, L-733,560, had a 90% effective dose against P. carinii cysts of 0.01 mg/kg of body weight when delivered parenterally (subcutaneously, twice daily for 4 days). This compound was also effective when given orally for the treatment and prevention of P. carinii pneumonia. For treating acute P. carinii pneumonia, oral doses of 2.2 mg/kg twice daily for 4 days were required to eliminate 90% of the cysts. A once-daily oral prophylactic dose of 2.2 mg/kg prevented cyst development, and a dose of 6.2 mg/kg prevented any development of P. carinii organisms (cysts and trophozoites), as determined through the use of a P. carinii-specific DNA probe (P. A. Liberator et al., J. Clin. Microbiol. 30:2968-2974, 1992). These results demonstrate that the antipneumocystis activities of the pneumocandins can be significantly improved through synthetic modification. Several of these compounds are also extremely effective against candidiasis (K. Bartizal et al., Antimicrob. Agents Chemother. 39:1070-1076, 1995) and aspergillosis (G. K. Abruzzo et al., Antimicrob. Agents Chemother. 39:860-894, 1995) in murine models, making them attractive as broad-spectrum antifungal agents.

Thrombinogenesis and its pharmacological modulation in atherosclerosis.

Appearance of thrombin in circulating blood can be monitored in the clinical setting by measuring specific thrombin markers, such as fibrinopeptide A, thrombin-antithrombin III or prothrombin fragment 1 + 2. In myocardial infarction monitoring of thrombin activity is of growing clinical interest. High levels of thrombin markers indicate an increased risk to a patient with myocardial infarction. Persistent, high thrombin marker levels, despite heparin anticoagulation, point to ongoing thrombin generation that may necessitate more anticoagulation, increased antiplatelet treatment, angioplasty or, in the future, use of new antithrombotic drugs. Recently, new sensitive methods have been developed to study the reaction of thrombin generation in clotting blood. These methods permitted to demonstrate that, aspirin, contrary to several other antiplatelet drugs, delay the process of thrombin formation. Continuous dampening of thrombin formation by aspirin might be one of the mechanisms responsible for its prophylactic and therapeutic efficacy. Hypercholesterolemic subjects might profit less than others from this type of treatment, since aspirin dampening effects are not so evident in hypercholesterolemia.

Serum immunoglobulin E and sudden cardiac arrest during myocardial infarction.

BACKGROUND: While studying the immunological response to acute myocardial infarction (AMI) we noticed that patients who on admission had a high serum immunoglobulin E (IgE) level were less likely to die suddenly. This observation seemed to deserve verification since atopic patients whose production of IgE was excessive had been reported to have depressed haemostatic platelet function and impaired thrombinogenesis. METHODS: We measured levels of serum IgE in 386 patients with AMI at the time of admission to the coronary care unit. Patients were divided into two groups, depending on the presence (n = 55) or absence (n = 331) of sudden cardiac arrest. The two groups did not differ with respect to age, sex, or risk factors for coronary artery disease. RESULTS: The mean level of serum IgE was significantly higher in the group without sudden cardiac arrest than in the group with this complication. In a separate study we found that high serum IgE levels were associated with delayed thrombin generation in the clotting blood of survivors of myocardial infarction. CONCLUSION: Early determination of serum IgE levels might help to detect patients at risk of sudden cardiac arrest during myocardial infarction. Patients with high serum IgE levels might be protected against sudden cardiac death through the depression of clot formation because of the late appearance of thrombin in their coronary arteries.

Persistent generation of thrombin after acute myocardial infarction.

During the acute phase of myocardial infarction, the generation of thrombin is reflected in the sudden rise of fibrinopeptide A (FPA) and the thrombin-antithrombin III (TAT) complex in blood. We have systematically determined the FPA and TAT plasma concentrations over a period of 14 days after acute myocardial infarction in 100 patients. Mean levels of both thrombin markers were the highest on admission, remained elevated over the following few days, and then gradually declined after day 5. Still, by the end of the first week two thirds of the patients had distinctly elevated TAT and FPA levels, and by the end of the second week such an abnormality was present in half of them. Continuous intravenous heparin infusion at a dose of 20,000 units/day, administered for 1 week to patients who had either received (n = 21) or not received (n = 17) streptokinase, led to a significant depression (p less than 0.05) of thrombin markers over the first 48 hours, an effect that did not persist over the subsequent days of treatment. In patients not assigned to heparin treatment, those in heart failure had significantly (p less than 0.05) higher mean TAT and FPA values on days 3, 5, and 7 compared with patients in whom heart failure was absent. Infarct extension, pulmonary embolism, and death were also associated with a rise in one or both thrombin markers, often preceding the onset of clinical symptoms. Thrombinogenesis was not accompanied by changes in mean plasma concentrations of prothrombin, antithrombin III, or alpha 2-macroglobulin.(ABSTRACT TRUNCATED AT 250 WORDS)

Serum immunoglobulin E response to myocardial infarction.

Mast cells have been implicated in the pathogenesis of coronary heart disease. They can be activated by immunoglobulin (Ig) E-mediated mechanisms to release powerful mediators affecting local blood flow. We have determined systematically serum IgE concentrations in 100 patients with acute myocardial infarction. There was a consistent pattern of change in serum IgE, characterized by a significant increase on the third and fifth day, peak values on the seventh day, and a gradual decline to initial levels by the end of the third week after infarction. The increase in serum IgE shortly after myocardial infarction was similar to the increase in blood eosinophil count, but was in contrast to serum IgG levels. After infarction, patients with high initial IgE levels (greater than 200 IU/ml) had a greater increase in IgE and less frequent severe complications than those whose initial IgE levels were below 200 IU/ml. In 16 subjects with acute coronary insufficiency without infarction serum IgE levels remained unchanged. It is suggested that in myocardial infarction circulating IgE sensitizes both mast cells of coronary arteries and eosinophils, invading ischemic myocardium; this facilitates release of chemical mediators. Patients with high IgE levels might be protected against complications of infarction because of a favorable ratio of locally released mediators and because of decreased platelet function.