bluuebunny/crossref_metadata_2025 huggingface dataset:
Invasive Aspergillosis in a Renal Transplant Recipient Successfully Treated with Interferon-Gamma
Authors: Estrada C. , Desai A. G. , Chirch L. M. , Suh H. , Seidman R. , Darras F. , Nord E. P.
Published: September 2012

Invasive aspergillosis is a serious complication of solid organ transplantation. An early diagnosis is hampered by the lack of reliable serum markers and, even if appropriately diagnosed and treated with current antifungal agents, has a high mortality rate. We report a case of invasive pulmonary and cerebral aspergillosis in a renal transplant patient treated with IFN-γin conjunction with combination anti-fungal therapy for six weeks in whom complete resolution of the fungal infection was achieved. Renal function remained intact throughout the treatment period. Surveillance CT scans of the chest and head showed resolution of prior disease but revealed a new left upper lobe mass four months after completion of treatment with IFN-γ. Biopsy of the lesion was positive for primary lung adenocarcinoma, for which she underwent left upper lobe resection. The pathology report confirmed clear surgical margins and lymph nodes and no evidence of fungal hyphae. IFN-γshould be considered early in the management of invasive aspergillosis in renal transplant patients. To date, allograft rejection has not been encountered.
Rare Case of Adult Undifferentiated (Embryonal) Sarcoma of the Liver Treated with Liver Transplantation: Excellent Long-Term Survival
Authors: Dhanasekaran Renumathy , Hemming Alan , Salazar Elaine , Cabrera Roniel
Published: September 2012

We present the case of a 54-year-old gentleman who presented with abdominal distension and a CT scan of his abdomen revealed a large (25 cm) left hepatic lobe tumor. He received chemotherapy for over 1.5 years. The CT scans at the completion of this therapy revealed that the tumor had actually slightly grown in size. He underwent orthotopic liver transplantation without any major complications. The explant histopathology revealed an undifferentiated embryonal cell sarcoma (UECS) composed of relatively bland spindled cells arranged in short fascicles. It is now 10 years and 3 months since his last transplant and the patient remains well with no tumor recurrence.
Contribution of Neurogenic and Allergic Ways to the Pathophysiology of Nonallergic Rhinitis
Authors: Kavut Ayşe Baççıoğlu , Kalpaklıoğlu Füsun , Atasoy Pinar
Published: September 2012

Background: A neuroallergic interaction was reported in the pathogenesis of allergic rhinitis (AR), but the pathophysiology of nonallergic rhinitis (NAR) is poorly understood. We aimed to explore the contribution of neuroallergic mechanisms to the pathogenesis of NAR. Methods: Subjects were divided into three groups – NAR patients (n = 25), AR patients (n = 16) and the control group (n = 10) – and were assessed using the nasal provocation test (NPT) with house dust mite. Total symptom scores, nasal inspiratory peak flow and nasal lavage were performed before and after NPT. Nasal brushing and scraping was done after NPT. Results: NPT was positive in NAR (52%) and AR (100%) patients and negative in all controls. After NPT, total symptom scores increased in both rhinitis groups. Post-NPT values of nasal inspiratory peak flow decreased only in AR patients. NAR patients showed a similar inflammatory cell profile in the nasal smears to AR patients which was different in controls. There were more tryptase- and immunoglobulin E (IgE)-positive cells in the nasal mucosa of AR patients, and more substance-p-positive cells were observed in NAR patients compared with controls. However, IgE- and tryptase-positive cells in NAR patients and substance-p-positive cells in AR patients were detectable in nasal mucosa, but rarely in the controls. Comparing the values before and after NPT, tryptase significantly increased in the nasal lavages of AR and NAR patients, while house dust mite-specific IgE did not change. Conclusions: We showed the existence of a common pathophysiological mechanism with different contributions in AR and NAR. We conclude that the difference in dominance of neuroallergic ways may determine the major phenotype of rhinitis.
Evaluation of Natural Regulatory T Cells in Subjects with Selective IgA Deficiency: From Senior Idea to Novel Opportunities
Authors: Soheili Habib , Abolhassani Hassan , Arandi Narges , Khazaei Hossein Ali , Shahinpour Shervin , Hirbod-Mobarakeh Armin , Rezaei Nima , Aghamohammadi Asghar
Published: September 2012

Background: Selective IgA deficiency (SIgAD) is the most common primary immunodeficiency disorder, which is characterized by significantly decreased serum levels of IgA. Abnormalities of CD4+CD25highforkhead box P3 (FoxP3)+ regulatory T cells (Treg) have been shown in association with autoimmune and inflammatory disorders. Methods: In order to evaluate the relationship between autoimmunity and Treg in SIgAD, we studied 26 IgA-deficient patients (aged 4–17 years) with serum IgA levels <7 mg/dl, 26 age- and sex-matched healthy controls and 26 age- and sex matched idiopathic thrombocytopenic purpura cases with normal immune system. Treg were determined by flow cytometry using Treg markers, including CD4, CD25 and FoxP3. Results: The mean percentage of CD4, CD25+FoxP3+ Treg from all CD4+ cells was 4.08 ± 0.86 in healthy controls, which was significantly higher than in SIgAD patients (2.93 ± 1.3; p = 0.003). We set a cutoff point (2.36%) for Treg, which was two standard deviations lower than the mean of normal controls. According to this cutoff point and in order to assess the role of Treg in clinical SIgAD manifestation, we classified patients into two groups: 16 patients in G1 with Treg <2.36% and 10 patients in G2 with Treg >2.36%. Autoimmunity was recorded in 9 patients (53.3%) of G1 and only 1 patient of G2, respectively (p = 0.034). Although a defect in class switching recombination was observed in 40% of the patients in G1, none of the G2 patients had such a defect (p = 0.028). Conclusion: This study showed decreased proportions of Treg in SIgAD patients, particularly in those with signs of chronic inflammation.
Capsaicin for Neuropathic Pain: Linking Traditional Medicine and Molecular Biology
Authors: Haanpää Maija , Treede Rolf-Detlef
Published: September 2012

Capsaicin has long been used as a traditional medicine to treat pain and, recently, its mechanism of analgesic action has been discovered. This review article documents the clinical development of capsaicin to demonstrate that pharmacognosy still has a profound influence on modern-day drug development programs. Capsaicin is a highly selective agonist for the transient receptor potential channel vanilloid-receptor type 1 (TRPV1), which is expressed on central and peripheral terminals of nociceptive primary sensory neurons. Knockout studies have revealed the importance of TRPV1 as a molecular pain integrator and target for novel analgesic agents. Topical application of capsaicin at the peripheral terminal of TRPV1-expressing neurons superficially denervates the epidermis in humans in a highly selective manner and results in hypoalgesia. In three recent randomized controlled trials, a patch containing high-concentration capsaicin demonstrated meaningful efficacy and tolerability relative to a low-concentration capsaicin control patch in patients with peripheral neuropathic pain. Data from clinical practice will determine if the high-concentration capsaicin patch is effective in real-world settings.
‘Bovine’ Aortic Arch – A Marker for Thoracic Aortic Disease
Authors: Hornick Matthew , Moomiaie Remo , Mojibian Hamid , Ziganshin Bulat , Almuwaqqat Zakaria , Lee Esther S. , Rizzo John A. , Tranquilli Maryann , Elefteriades John A.
Published: September 2012

Objectives: Very few studies have addressed the clinical significance of ‘bovine’ aortic arch (BA). We sought to determine whether BA is associated with thoracic aortic disease, including thoracic aortic aneurysm, aortic dissection, aortic rupture, and accelerated aortic growth rate. Methods: We retrospectively reviewed CT and/or MRI scans of 612 patients with thoracic aortic disease and 844 patients without thoracic aortic disease to determine BA prevalence. In patients with thoracic aortic disease, we reviewed hospital records to determine growth rate, prevalence of dissection and rupture, and accuracy of radiology reports in citing BA. Results: 26.3% of the patients with thoracic aortic disease had concomitant BA, compared to 16.4% of the patients without thoracic aortic disease (p < 0.001). There was no association between BA and prevalence of dissection or rupture (p = 0.38 and p = 0.56, respectively). The aortic expansion rate was 0.29 cm/year in the BA group and 0.09 cm/year in the non-BA group (p = 0.004). Radiology reports cited BA in only 16.1% of the affected patients. Conclusions: (1) BA is significantly more common in patients with thoracic aortic disease than in the general population. (2) Aortas expand more rapidly in the setting of BA. (3) Radiology reports often overlook BA. (4) BA should not be considered a ‘normal’ anatomic variant.
Voice Risk Factors in Kindergarten Teachers in Greece
Authors: Helidoni Meropi , Murry Thomas , Chlouverakis Gregory , Okalidou Areti , Velegrakis George
Published: September 2012

Objective: The purpose of this study was to identify voice risk factors for female kindergarten teachers and nurses in Heraklion, Crete. Patients and Methods: A questionnaire consisting of voice use and lifestyle activities was given to 200 kindergarten teachers in Heraklion, Crete, of which 151 were returned (75.5%). A group of 89 nurses served as the control group. Both groups also completed the Greek version of the Voice Handicap Index (VHI-G). Results: Kindergarten teachers sing more often, speak loudly more often when they are at work and present with more infections of the upper respiratory tract compared to nurses. They talk less than 30 min per day on the phone, drink less alcohol and water and smoke less in comparison with nurses. The median VHI-G score for the kindergarten teachers was significantly higher than that for the nurses. Conclusion: The results suggest that there is a difference in the factors that may be responsible for the appearance of voice problems in kindergarten teachers and in nurses. For kindergarten teachers, the risk factors for voice disorders are primarily related to vocal load factors and for nurses appear to be lifestyle-related more than voice use alone.
Acutely Ill Patients in Internal Medicine Departments Want Treatment for Undiagnosed, Symptomatic Skin Conditions
Authors: Goeksu Yasemin , Zimmerli Lukas U. , Braun Ralph P. , Klaghofer Richard , French Lars E. , Battegay Edouard , Navarini Alexander A.
Published: September 2012

Objective: Concomitant skin conditions may be neglected in internal medicine patients due to lack of knowledge or resources. Thus, we investigated the prevalence of undiagnosed skin conditions in this population. Methods: 200 patients in a university medical center’s internal medicine division were examined clinically for dermatoses and quality of life in a prospective, 2-month, single-center study. Results: All patients had several dermatological problems (mean per patient: 13; range: 3–25). There was no relationship between the patient’s main medical problem and the number or nature of dermatological conditions. Most patients (84%) requested treatment for their skin condition during hospitalization, especially for xerosis (76%), warts (69%), seborrheic eczema (67%) and onychorrhexis (53%) but not for asymptomatic dermatoses. The impairment in skin-related quality of life was mild but significant, with a mean ± SD Dermatology Life Quality Index of 3 ± 4 (p < 0.001), and global quality of life impairment was severe (p < 0.001). Conclusions: Inpatients suffered from many different, mostly age-related, skin conditions that remained undiagnosed. When prompted, however, patients requested treatment, particularly for symptomatic dermatological conditions such as xerosis, revealing an unmet need that needs to be addressed by qualified evaluation and care.
Frequency, Risk Factors, Prognosis, and Genetic Polymorphism of the Cyclooxygenase-1 Gene for Aspirin Resistance in Elderly Chinese Patients with Cardiovascular Disease
Authors: Fan Li , Cao Jian , Liu Lin , Li Xiaoli , Hu Guoliang , Hu Yixin , Zhu Bingpo
Published: September 2012

Background: Cardiovascular disease (CVD) is an important cause of mortality in elderly patients worldwide. Aspirin resistance has been well reported in CVD. Objective: The frequency, risk factors, prognosis, and genetic polymorphism of the cyclooxygenase-1 (COX-1) gene for aspirin resistance have not been reported in elderly patients with CVD. We therefore undertook this study to evaluate these associations among elderly Chinese patients with CVD. Methods: Four hundred thirty-one elderly Chinese patients with CVD receiving daily aspirin therapy (≥75 mg) over 1 month were enrolled. Platelet aggregation was measured by light transmission aggregometry (LTA) and thromboelastography platelet mapping assay (TEG) using arachidonic acid (AA) as a stimulus. The median follow-up was 1.8 years. Results: After the median follow-up, aspirin-resistant patients were at an increased risk of the composite endpoint compared to nonresistant patients by LTAAA + TEGAA (23.7 vs. 9.2%, p = 0.025). Additionally, Cox proportional hazards regression modeling demonstrated that aspirin resistance and cerebrovascular disease were associated with major adverse long-term outcomes (HR for aspirin resistance = 2.31, 95% CI 1.11-4.81, p = 0.026). The variant G-allele of COX-1 rs1330344 (-1676 A/G) significantly increased the risk of aspirin resistance defined by LTAAA + TEGAA (OR = 1.82, 95% CI 1.13- 2.92, p = 0.01). Conclusions: Aspirin resistance, evaluated by LTAAA + TEGAA, is associated with an increased risk of adverse clinical events in elderly Chinese patients with CVD. The variant G-allele of COX-1 rs1330344 is significantly associated with aspirin resistance defined by LTAAA + TEGAA.
The Thr715Pro variant impairs terminal glycosylation of P-selectin
Authors: Subramanian Hariharan , Gambaryan Stepan , Panzer Simon , Gremmel Thomas , Walter Ulrich , Mannhalter Christine
Published: September 2012

P-selectin variant 715Pro is associated with lower concentrations of plasma P-selectin and reduced risk for thrombosis. We examined the influence of 715Pro on P-selectin synthesis, post-translational processing, surface expression and function using HEK293 cells, which do not express endogenous P-selectin. Mass spectrometry revealed that HEK293 cells produced recombinant P-selectin which has a glycosylation pattern comparable to platelet P-selectin. Compared to wild-type transfectants, 715Pro transfectants have ~50% less terminally glycosylated P-selectin and accumulate more immature P-selectin in Golgi. Following Brefeldin A treatment, the majority of 715Pro P-selectin is not modified by Golgi enzymes, while wild-type P-selectin undergoes complete modification. Flow cytometry revealed that 715Pro transfectants have ~20% less P-selectin on the cell surface compared to wild-type transfectants. Secretion of P-selectin by 715Pro transfectants was about 38% lower compared to wild-type transfectants. Binding of HL-60 cells to 715Pro transfectants was ~29% lower than to wild-type transfectants. This observation was confirmed by the presence of fewer platelet-monocyte aggregates (PMA) in the blood of healthy individuals and patients with angiographically proven atherosclerosis, carrying 715Pro P-selectin compared to individuals with wild-type P-selectin. We conclude that the 715Pro variant impairs terminal glycosylation of P-selectin in Golgi, leading to reduced amounts of mature P-selectin and subsequently less surface expression and secretion of P-selectin. The reduced surface expression of 715Pro P-selectin contributes to inefficient adhesion to HL-60 cells or monocytes.
Efficacy and safety of prophylaxis with once-weekly BAY 79–4980 compared with thrice-weekly rFVIII-FS in haemophilia A patients
Authors: Martinowitz Uri , Windyga Jerzy , Di Minno Giovanni , Hellmann Andrzej , Pabinger Ingrid , Enriquez Monika , Schwartz Lawrence , Ingerslev Jørgen , Powell Jerry ,   the LipLong Study Investigators
Published: September 2012

The benefits of prophylaxis of haemophilia A patients regarding joint health and quality-of-life are well established. However, adherence to an up to every-other-day infusion regimen is a barrier to widespread adoption of prophylaxis. BAY 79–4980 is an investigational drug consisting of rFVIII-FS (sucrose-formulated recombinant FVIII) reconstituted with liposome solvent. Previous clinical studies showed extended protection from bleeding after a single injection of BAY 79–4980 (13.3 ± 6.2 days) compared with rFVIII-FS (7.2 ± 1.7 days). The effect of once-a-week prophylaxis with BAY 79–4980 (35 IU/kg) compared with three times-per-week rFVIII-FS (25 IU/kg) in previously treated, severe haemophilia A patients was evaluated in a 52-week, double-blind, two-arm, randomised, controlled study. The primary and secondary endpoints were protection from total bleeds and joint bleeds, respectively. Short- and long-term safety and tolerability of BAY 79–4980 including effects on lipid levels were assessed. A total of 139 and 131 subjects were evaluable for safety and efficacy analyses, respectively. A large difference in efficacy between treatment groups was observed with 72.1% (49/68) in the rFVIII-FS control group demonstrating <9 bleeds/year compared with 38.1% (24/63) of BAY 79–4980-treated subjects. A similar difference was seen in annualised joint bleeds, with 43 subjects (63.2%) in the control group demonstrating <5 joint bleeds/year compared with 24 subjects (38.1%) treated with BAY 79–4980. The distribution of bleeds seven days post-prophylactic treatment with BAY 79–4980 showed that 61% of bleeds occurred after day 4 post dosing. There were no safety concerns identified. The investigational treatment arm was prematurely discontinued due to failure to achieve the primary endpoint.
Management consensus guidance for the use of rivaroxaban – an oral, direct factor Xa inhibitor
Authors: Kreutz Reinhold , Llau Juan , Norrving Bo , Haas Sylvia , Turpie Alexander
Published: September 2012

A number of novel oral anticoagulants that directly target factor Xa or thrombin have been developed in recent years. Rivaroxaban and apixaban (direct factor Xa inhibitors) and dabigatran etexilate (a direct thrombin inhibitor) have shown considerable promise in large-scale, randomised clinical studies for the management of thromboembolic disorders, and have been approved for clinical use in specific indications. Rivaroxaban is licensed for the prevention of venous thromboembolism in patients undergoing elective hip or knee replacement surgery, the treatment of deep-vein thrombosis and prevention of recurrent venous thromboembolism, and for stroke prevention in patients with non-valvular atrial fibrillation. Based on the clinical trial data for rivaroxaban, feedback on its use in clinical practice and the authors’ experience with the use of rivaroxaban, practical guidance for the use of rivaroxaban in special patient populations and specific clinical situations is provided. Although most recommendations are in line with the European summary of product characteristics for the approved indications, additional and, in several areas, different recommendations are given based on review of the literature and the authors’ clinical experience.
A novel D235Y mutation in the GP1BA gene enhances platelet interaction with von Willebrand factor in an Iranian family with platelet-type von Willebrand disease
Authors: Enayat Said , Ravanbod Shirin , Rassoulzadegan Maryam , Jazebi Mohammad , Tarighat Shirin , Ala Fereydoun , Emsley Jonas , Othman Maha
Published: September 2012

Platelet-type von Willebrand disease (PT-VWD) is a rare bleeding disorder with an intrinsic defect in platelets rather than von Willebrand factor (VWF), but has clinical and laboratory features similar to the more common type 2B VWD. The intriguing nature of the pathophysiology and molecular genetics of PT-VWD has created lengthy debate in literature regarding its discrimination from type 2B VWD, and essentially confirming DNA analysis as the gold standard in diagnosis and revealing pathologic mutations. In this report we identify a novel Asp235Tyr mutation in the GP1BA gene of two Iranian patients showing the PT-VWD phenotype who were originally misdiagnosed as type 2B VWD. By structural modelling of the mutant by introducing Tyr235 into the available crystal structure of the glycoprotein (GP)Ibα N-terminal domain, we observed the mutant Tyr235 generates a hydrophobic tip to the extended β-switch loop of GPIbα. Further modelling of the resulting complex with VWFA1 indicates this could result in an enhanced interface compared to wild-type Asp235. This data provides an update to the present knowledge about this rare disorder, and confirms the necessity of genetic testing for accurate diagnosis, and the importance of studying natural mutations to better understand molecular aspects of GPIbα-VWFA1 interaction.
Reduction of cAMP and cGMP inhibitory effects in human platelets by MRP4-mediated transport
Authors: Borgognone Alessandra , Pulcinelli Fabio
Published: September 2012

Cyclic nucleotide-dependent inhibition of platelets represents the most important physiological way to limit thrombus formation. cAMP and cGMP increase in platelets as a consequence of prostacyclin and nitric oxide production by endothelial cells and act through PKA and PKG, respectively. The cytosolic concentration of cyclic nucleotides in platelets is regulated by AC- and GC-dependent synthesis and PDE-dependent degradation. In some cells cyclic nucleotides are eliminated also through MRP4/5/8-dependent efflux. As only MRP4 is expressed in platelets, at high levels in dense granules, we determined its role in the elimination of cyclic nucleotides from platelet cytosol. We studied the effects of MRP4 inhibition on cAMP/cGMP effects in platelets. Cyclic nucleotide inhibitory effects triggered by cAMP and cGMP-elevating agents on platelet aggregation are strongly enhanced by MRP4 inhibition and so is cyclic nucleotide-dependent phosphorylation of the common substrate VASP. MRP4 inhibition decreases cAMP concentration in platelet granules and both cAMP and cGMP compete with an established substrate of MRP4 (fluo-cAMP) for entrance in granules. Here we provide the first evidence of the transport of cyclic nucleotides mediated by MRP4 as part of their physiological mechanism of elimination in human platelets, which might represent a novel target to increase cyclic nucleotide-dependent inhibition.
Estimation of the warfarin dose with a pharmacogenetic refinement algorithm in Chinese patients mainly under low-intensity warfarin anticoagulation
Authors: Yang Jie , Gao Lei , Zhang Yan , Wang Hongjuan , Lu Caiyi , Zhao Yusheng , Xu Qiang , Xu Bin , Zhang Yuxiao , Yin Tong
Published: September 2012

Pharmacogenetic (PG) dosing algorithms have been confirmed to predict warfarin therapeutic dose more accurately;however, most of them are based on standard intensity of warfarin anticoagulation, and their utility outside this range is limited. This study was designed to develop and validate a PG refinement algorithm in Chinese patients mainly under low-intensity warfarin anticoagulation. Consented Chinese-Han patients (n=310) under stable warfarin treatment were randomly divided into a derivation (n=207) and a validation cohort (n=103), with 83% and 80% of the patients under low-intensity anticoagulation, respectively. In the derivation cohort, a PG algorithm was constructed on the basis of genotypes (CYP2C9*3 and VKORC1–1639A/G) and clinical data. After integrating additional covariates of international normalised ratio (INR) values (INR on day 4 of therapy and target INR) and genotype of CYP4F2 (rs2108622), a PG refinement algorithm was established and explained 54% of warfarin dose variability. In the validation cohort, warfarin dose prediction was more accurate (p <0.01) with the PG refinement algorithm than with the PG algorithm and the fixed dose approach (3 mg/day). In the entire cohort, the PG refinement algorithm could accurately identify larger proportions of patients with lower dose requirement (≤2 mg/day) and higher dose requirement (≥4 mg/day) than did the PG algorithm. In conclusion, PG refinement algorithm integrating early INR response and three genotypes CYP2C9*3, VKORC1–1639A/G, CYP4F2 rs2108622) improves the accuracy of warfarin dose prediction in Chinese patients mainly under low-intensity anticoagulation.
Thrombus and antiplatelet therapy in type 2 diabetes mellitus
Authors: Viswanathan Girish , Marshall Sally , Schechter Clyde , Balasubramaniam Karthik , Badimon José , Zaman Azfar
Published: September 2012

Type 2 diabetes mellitus (T2DM) is associated with higher rates of thrombotic complications in patients with coronary artery disease (CAD) despite optimal medical therapy. Thrombus area was measured in T2DM and non-diabetic patients receiving aspirin and clopidogrel 7–10 days after troponin positive Non ST-elevation acute coronary syndrome (NSTE-ACS). Secondly, we assessed response to clopidogrel in naive patients with T2DM and stable CAD in a randomised controlled trial. Thrombus area was measured by Badimon chamber and platelet reactivity by VerifyNow®. In T2DM patients presenting with NSTE-ACS, thrombus area was greater compared to non-diabetic patients (mean ± SD, 20,512 ± 12,567 [n=40] vs. 14,769 ± 8,531 [n=40] μm2/mm, p=0.02) Clopidogrel decreased thrombus area among stable CAD patients with T2DM (mean ± SD, Clopidogrel [n=45]: 13,978 ± 5,502 to 11,192 ± 3,764 μm2/mm vs. placebo [n=45]: 13,959 ± 7,038 to 14,201 ± 6,780 μm2/mm, p<0.001, delta values: clopidogrel vs. placebo, mean ± SD, 2,786 ± 4,561 vs. –249 ± 2,478, p<0.0005). Only 44% of patients with CAD and T2DM responded to clopidogrel as per VerifyNow® (cut-off PRUz value of ≥240). Importantly, no correlation was observed between thrombus area and VerifyNow® values (rho 0.08, p=0.49). Thrombus area values were similar among hypo-responders and good responders to clopidogrel (mean thrombus area ± SD: 12,186 ± 4,294 vs. 10,438 ± 3,401; p=0.17). Type 2 diabetes mellitus is associated with an increased blood thrombogenicity among NSTE-ACS patients on currently recommended medical therapy. Thrombus area was significantly reduced in all stable CAD patients independently of their response to clopidogrel therapy.
Contribution of the NH2-terminal EGF-domain of factor IXa to the specificity of intrinsic tenase
Authors: Qureshi Shabir , Yang Likui , Rezaie Alireza
Published: September 2012

Factor IXa (FIXa) is a vitamin K-dependent coagulation serine protease which binds to factor VIIIa (FVIIIa) on negatively charged phospholipid vesicles (PCPS) to catalyse the activation of factor X (FX) to factor Xa (FXa) in the intrinsic pathway. Fluorescence resonance energy transfer (FRET) studies have indicated that the Gla-domain-dependent interaction of FIXa and FX with PCPS in the presence of FVIIIa positions the active-site of the protease at an appropriate height above the membrane surface to optimise the catalytic reaction. In this study, we investigated the contribution of the NH2-terminal EGF-domain (EGF1) of FIXa to the recognition specificity of intrinsic tenase by constructing an EGF1 deletion mutant of FIXa (FIXa-desEGF1) and characterising the properties of the mutant in kinetic, direct binding and FRET assays. The results of direct binding and kinetic studies demonstrated that the binding affinity of the mutant for interaction with FVIIIa on PCPS has been impaired greater than 10-fold and the catalytic efficiency of the mutant protease FVIIIa-PCPS complex in the activation of FX has been decreased 100-fold. By contrast, the mutant protease exhibited a normal activity toward FX in the absence of the protein cofactor. FRET measurements revealed that the distance of the active-site of the mutant FIXa relative to PCPS vesicles has been decreased 10 Åfrom 75 ±2 Åfor FIXa to 65 ±2 Åfor FIXa-desEGF1 independent of FVIIIa. These results suggest that the NH2-terminal EGF-domain of FIXa provides a binding-site for FVIIIa and plays an essential spacer function in the intrinsic tenase complex.
Elevation of Plasma High-Density Lipoproteins Inhibits Development of Experimental Abdominal Aortic Aneurysms
Authors: Torsney Evelyn , Pirianov Grisha , Charolidi Nicoletta , Shoreim Azza , Gaze David , Petrova Slaveia , Laing Ken , Meisinger Trevor , Xiong Wanfen , Baxter B. Timothy , Cockerill Gillian W.
Published: September 2012

Objective—

Patients with abdominal aortic aneurysms have lower concentrations of high-density lipoproteins (HDLs), leading us to investigate whether increasing plasma HDLs could influence aneurysm formation.

Methods and Results—

Using the angiotensin II−induced hypercholesterolemic and the CaCl
2
-induced normocholesterolemic mouse model of AAA, we investigated the hypothesis that elevation of HDLs inhibits AAA. HDLs elevated before or at the time of AAA induction reduced AAA formation in both models but had no effect on early ruptures. Analysis of protein lysates from specific aortic segments demonstrated site-specific effects of HDLs on early signal transduction and cellular attrition. We found that HDLs reduced extracellular signal related kinases 1/2 activation in the suprarenal segment, while having no effect on p38 mitogen-associated protein kinase activation in any aortic segment and inhibiting c-Jun N-terminal kinase activation in all aortic segments. In addition, HDL elevation inhibited angiotensin II−induced apoptosis while inducing autophagy in the suprarenal segment of the aorta. Using Illumina gene array profiling we investigated the ability of HDL to modulate basal suprarenal aortic gene expression.

Conclusion—

Increasing plasma HDLs inhibit experimental AAA formation, independent of hypercholesterolemia via reduced extracellular signal related kinases 1/2 activation and alteration of the balance of cellular attrition. HDLs modulate genes involved in matrix remodelling, cell migration, and proliferation.
Myeloid-Specific IκB Kinase β Deficiency Decreases Atherosclerosis in Low-Density Lipoprotein Receptor–Deficient Mice
Authors: Park Se-Hyung , Sui Yipeng , Gizard Florence , Xu Jinxian , Rios-Pilier Jennifer , Helsley Robert N. , Han Seong-Su , Zhou Changcheng
Published: September 2012

Objective—

Inflammatory responses are the driving force of atherosclerosis development. IκB kinase β (IKKβ), a central coordinator in inflammation through regulation of nuclear factor-κB, has been implicated in the pathogenesis of atherosclerosis. Macrophages play an essential role in the initiation and progression of atherosclerosis, yet the role of macrophage IKKβ in atherosclerosis remains elusive and controversial. This study aims to investigate the impact of IKKβ expression on macrophage functions and to assess the effect of myeloid-specific IKKβ deletion on atherosclerosis development.

Methods and Results—

To explore the issue of macrophage IKKβ involvement of atherogenesis, we generated myeloid-specific IKKβ-deficient low-density lipoprotein receptor–deficient mice (IKKβ
ΔMye
LDLR
−/−
). Deficiency of IKKβ in myeloid cells did not affect plasma lipid levels but significantly decreased diet-induced atherosclerotic lesion areas in the aortic root, brachiocephalic artery, and aortic arch of low-density lipoprotein receptor–deficient mice. Ablation of myeloid IKKβ attenuated macrophage inflammatory responses and decreased atherosclerotic lesional inflammation. Furthermore, deficiency of IKKβ decreased adhesion, migration, and lipid uptake in macrophages.

Conclusion—

The present study demonstrates a pivotal role for myeloid IKKβ expression in atherosclerosis by modulating macrophage functions involved in atherogenesis. These results suggest that inhibiting nuclear factor-κB activation in macrophages may represent a feasible approach to combat atherosclerosis.
Lipid Oxidation in Carriers of Lecithin:Cholesterol Acyltransferase Gene Mutations
Authors: Holleboom Adriaan G. , Daniil Georgios , Fu Xiaoming , Zhang Renliang , Hovingh G. Kees , Schimmel Alinda W. , Kastelein John J.P. , Stroes Erik S.G. , Witztum Joseph L. , Hutten Barbara A. , Tsimikas Sotirios , Hazen Stanley L. , Chroni Angeliki , Kuivenhoven Jan Albert
Published: September 2012

Objective—

Lecithin:cholesterol acyltransferase (LCAT) has been shown to play a role in the depletion of lipid oxidation products, but this has so far not been studied in humans. In this study, we investigated processes and parameters relevant to lipid oxidation in carriers of functional
LCAT
mutations.

Methods and Results—

In 4 carriers of 2 mutant
LCAT
alleles, 63 heterozygotes, and 63 family controls, we measured activities of LCAT, paraoxonase 1, and platelet-activating factor-acetylhydrolase; levels of lysophosphatidylcholine molecular species, arachidonic and linoleic acids, and their oxidized derivatives; immunodetectable oxidized phospholipids on apolipoprotein (apo) B–containing and apo(a)-containing lipoproteins; IgM and IgG autoantibodies to malondialdehyde-low-density lipoprotein and IgG and IgM apoB-immune complexes; and the antioxidant capacity of high-density lipoprotein (HDL). In individuals with
LCAT
mutations, plasma LCAT activity, HDL cholesterol, apoA-I, arachidonic acid, and its oxidized derivatives, oxidized phospholipids on apo(a)-containing lipoproteins, HDL-associated platelet-activating factor-acetylhydrolase activity, and the antioxidative capacity of HDL were gene-dose–dependently decreased. Oxidized phospholipids on apoB-containing lipoproteins was increased in heterozygotes (17%;
P
<0.001) but not in carriers of 2 defective
LCAT
alleles.

Conclusion—

Carriers of
LCAT
mutations present with significant reductions in LCAT activity, HDL cholesterol, apoA-I, platelet-activating factor-acetylhydrolase activity, and antioxidative potential of HDL, but this is not associated with parameters of increased lipid peroxidation; we did not observe significant changes in the oxidation products of arachidonic acid and linoleic acid, immunoreactive oxidized phospholipids on apo(a)-containing lipoproteins, and IgM and IgG autoantibodies against malondialdehyde-low-density lipoprotein. These data indicate that plasma LCAT activity, HDL-associated platelet-activating factor-acetylhydrolase activity, and HDL cholesterol may not influence the levels of plasma lipid oxidation products.
Hydrogen Sulfide–Releasing Aspirin Derivative ACS14 Exerts Strong Antithrombotic Effects In Vitro and In Vivo
Authors: Pircher Joachim , Fochler Franziska , Czermak Thomas , Mannell Hanna , Kraemer Bjoern F. , Wörnle Markus , Sparatore Anna , Del Soldato Piero , Pohl Ulrich , Krötz Florian
Published: September 2012

Objective—

Hydrogen sulfide (H
2
S)–releasing NSAIDs exert potent anti-inflammatory effects beyond classical cyclooxygenase inhibition. Here, we compared the platelet inhibitory effects of the H
2
S-releasing aspirin derivative ACS14 with its mother compound aspirin to analyze additional effects on platelets.

Methods and Results—

In platelets of mice fed with ACS14 for 6 days (50 mg/kg per day), not only arachidonic acid–induced platelet aggregation but also ADP-dependent aggregation was decreased, an effect that was not observed with an equimolar dose of aspirin (23 mg/kg per day). ACS14 led to a significantly longer arterial occlusion time after light-dye–induced endothelial injury as well as decreased thrombus formation after ferric chloride-induced injury in the carotid artery. Bleeding time was not prolonged compared with animals treated with equimolar doses of aspirin. In vitro, in human whole blood, ACS14 (25–500 µmol/L) inhibited arachidonic acid–induced platelet aggregation, but compared with aspirin additionally reduced thrombin receptor–activating peptide–, ADP-, and collagen-dependent aggregation. In washed human platelets, ACS14 (500 µmol/L) attenuated αIIbβ3 integrin activation and fibrinogen binding and increased intracellular cAMP levels and cAMP-dependent vasodilator-stimulated phosphoprotein (VASP) phosphorylation.

Conclusion—

The H
2
S-releasing aspirin derivative ACS14 exerts strong antiaggregatory effects by impairing the activation of the fibrinogen receptor by mechanisms involving increased intracellular cyclic nucleotides. These additional antithrombotic properties result in a more efficient inhibition of thrombus formation in vivo as achieved with aspirin alone.
Novel Biological Functions of High-Density Lipoprotein Cholesterol
Authors: Mineo Chieko , Shaul Philip W.
Published: September 2012

In addition to its role in reverse cholesterol transport, high-density lipoprotein (HDL) cholesterol has direct action on numerous cell types that influence cardiovascular and metabolic health. Cellular responses to HDL entail its capacity to invoke cholesterol efflux that causes signal initiation via scavenger receptor class B, type I, and plasma membrane receptor activation by HDL cargo molecules. In endothelial cells and their progenitors, HDL attenuates apoptosis and stimulates proliferation and migration. HDL also has diverse anti-inflammatory actions in both endothelial cells and leukocytes. In vascular smooth muscles, HDL tempers proinflammatory, promigratory, and degradative processes, and through actions on endothelium and platelets HDL is antithrombotic. There are additional actions of HDL of potential cardiovascular consequence that are indirect, including the capacities to promote pancreatic β-cell insulin secretion, to protect pancreatic β cells from apoptosis, and to enhance glucose uptake by skeletal muscle myocytes. Furthermore, HDL decreases white adipose tissue mass, increases energy expenditure, and promotes the production of adipose-derived cytokine adiponectin that has its own vascular-protective properties. Many of these numerous actions of HDL have been observed not only in cell culture and animal models but also in human studies, and assessments of these functions are now being applied to patient populations to better-elucidate which actions of HDL may contribute to its cardioprotective potential and how they can be quantified and targeted. Further work on the many mechanisms of HDL action promises to reveal new prophylactic and therapeutic strategies to optimize both cardiovascular and metabolic health.
Oral Direct Factor Xa Inhibitors
Authors: Yeh Calvin H. , Fredenburgh James C. , Weitz Jeffrey I.
Published: September 2012

Vitamin K antagonists, such as warfarin, have been the mainstay of oral anticoagulation for many decades. Although effective, warfarin has numerous limitations, including a variable dose requirement from patient to patient because of differences in dietary vitamin K intake, common genetic polymorphisms, and multiple drug interactions that affect its pharmacodynamics and metabolism. Consequently, warfarin requires frequent monitoring to ensure that a therapeutic anticoagulant effect has been achieved because excessive anticoagulation can lead to bleeding, and because insufficient anticoagulation can result in thrombosis. Such monitoring is burdensome for patients and physicians and is costly for the health care system. These limitations have prompted the development of new oral anticoagulants that target either factor Xa or thrombin. Although the path to the development of these drugs has been long, the new drugs are at least as effective and safe as warfarin, but they streamline clinical care because they can be administered in fixed doses without routine coagulation monitoring. This article focuses on rivaroxaban, apixaban, and edoxaban, the oral factor Xa inhibitors in the most advanced stages of development. After 20 years of discovery research, these agents are already licensed for several indications. Thus, the long path to finding replacements for warfarin has finally reached fruition. Therefore, development of the oral factor Xa inhibitors represents a translational science success story.
Letter to the Editor on NaV1.8
Authors: Numann Randy E. , Gibson John K.
Published: September 2012

Letters to the Editor will be published, if suitable, as space permits. They should not exceed 1000 words (typed double-spaced) in length and may be subject to editing or abridgment.
Response to Numann and Gibson
Authors: Yang Tao , Roden Dan M.
Published: September 2012

Letters to the Editor will be published, if suitable, as space permits. They should not exceed 1000 words (typed double-spaced) in length and may be subject to editing or abridgment.
Ca
2+
/Calmodulin-Dependent Protein Kinase II–Based Regulation of Voltage-Gated Na
+
Channel in Cardiac Disease
Authors: Koval Olha M. , Snyder Jedidiah S. , Wolf Roseanne M. , Pavlovicz Ryan E. , Glynn Patric , Curran Jerry , Leymaster Nicholas D. , Dun Wen , Wright Patrick J. , Cardona Natalia , Qian Lan , Mitchell Colleen C. , Boyden Penelope A. , Binkley Philip F. , Li Chenglong , Anderson Mark E. , Mohler Peter J. , Hund Thomas J.
Published: September 2012

Background—

Human gene variants affecting ion channel biophysical activity and/or membrane localization are linked to potentially fatal cardiac arrhythmias. However, the mechanism for many human arrhythmia variants remains undefined despite more than a decade of investigation. Posttranslational modulation of membrane proteins is essential for normal cardiac function. Importantly, aberrant myocyte signaling has been linked to defects in cardiac ion channel posttranslational modifications and disease. We recently identified a novel pathway for posttranslational regulation of the primary cardiac voltage-gated Na
+
channel (Na
v
1.5) by Ca
2+
/calmodulin-dependent protein kinase II (CaMKII). However, a role for this pathway in cardiac disease has not been evaluated.

Methods and Results—

We evaluated the role of CaMKII-dependent phosphorylation in human genetic and acquired disease. We report an unexpected link between a short motif in the Na
v
1.5 DI-DII loop, recently shown to be critical for CaMKII-dependent phosphorylation, and Na
v
1.5 function in monogenic arrhythmia and common heart disease. Experiments in heterologous cells and primary ventricular cardiomyocytes demonstrate that the human arrhythmia susceptibility variants (A572D and Q573E) alter CaMKII-dependent regulation of Na
v
1.5, resulting in abnormal channel activity and cell excitability. In silico analysis reveals that these variants functionally mimic the phosphorylated channel, resulting in increased susceptibility to arrhythmia-triggering afterdepolarizations. Finally, we report that this same motif is aberrantly regulated in a large-animal model of acquired heart disease and in failing human myocardium.

Conclusions—

We identify the mechanism for 2 human arrhythmia variants that affect Na
v
1.5 channel activity through direct effects on channel posttranslational modification. We propose that the CaMKII phosphorylation motif in the Na
v
1.5 DI-DII cytoplasmic loop is a critical nodal point for proarrhythmic changes to Na
v
1.5 in congenital and acquired cardiac disease.
tDCS Modulation of Visually Induced Analgesia
Authors: Mancini Flavia , Bolognini Nadia , Haggard Patrick , Vallar Giuseppe
Published: September 2012

Multisensory interactions can produce analgesic effects. In particular, viewing one's own body reduces pain levels, perhaps because of changes in connectivity between visual areas specialized for body representation, and sensory areas underlying pain perception. We tested the causal role of the extrastriate visual cortex in triggering visually induced analgesia by modulating the excitability of this region with transcranial direct current stimulation (tDCS). Anodal, cathodal, or sham tDCS (2 mA, 10 min) was administered to 24 healthy participants over the right occipital or over the centro-parietal areas thought to be involved in the sensory processing of pain. Participants were required to rate the intensity of painful electrical stimuli while viewing either their left hand or an object occluding the left hand, both before and immediately after tDCS. We found that the analgesic effect of viewing the body was enhanced selectively by anodal stimulation of the occipital cortex. The effect was specific for the polarity and the site of stimulation. The present results indicate that visually induced analgesia may depend on neural signals from the extrastriate visual cortex.
Normal Aging Delays and Compromises Early Multifocal Visual Attention during Object Tracking
Authors: Störmer Viola S. , Li Shu-Chen , Heekeren Hauke R. , Lindenberger Ulman
Published: September 2012

Declines in selective attention are one of the sources contributing to age-related impairments in a broad range of cognitive functions. Most previous research on mechanisms underlying older adults' selection deficits has studied the deployment of visual attention to static objects and features. Here we investigate neural correlates of age-related differences in spatial attention to multiple objects as they move. We used a multiple object tracking task, in which younger and older adults were asked to keep track of moving target objects that moved randomly in the visual field among irrelevant distractor objects. By recording the brain's electrophysiological responses during the tracking period, we were able to delineate neural processing for targets and distractors at early stages of visual processing (∼100–300 msec). Older adults showed less selective attentional modulation in the early phase of the visual P1 component (100–125 msec) than younger adults, indicating that early selection is compromised in old age. However, with a 25-msec delay relative to younger adults, older adults showed distinct processing of targets (125–150 msec), that is, a delayed yet intact attentional modulation. The magnitude of this delayed attentional modulation was related to tracking performance in older adults. The amplitude of the N1 component (175–210 msec) was smaller in older adults than in younger adults, and the target amplification effect of this component was also smaller in older relative to younger adults. Overall, these results indicate that normal aging affects the efficiency and timing of early visual processing during multiple object tracking.
Columnar Processing in Primate pFC: Evidence for Executive Control Microcircuits
Authors: Opris Ioan , Hampson Robert E. , Gerhardt Greg A. , Berger Theodore W. , Deadwyler Sam A.
Published: September 2012

A common denominator for many cognitive disorders of human brain is the disruption of neural activity within pFC, whose structural basis is primarily interlaminar (columnar) microcircuits or “minicolumns.” The importance of this brain region for executive decision-making has been well documented; however, because of technological constraints, the minicolumnar basis is not well understood. Here, via implementation of a unique conformal multielectrode recording array, the role of interlaminar pFC minicolumns in the executive control of task-related target selection is demonstrated in nonhuman primates performing a visuomotor DMS task. The results reveal target-specific, interlaminar correlated firing during the decision phase of the trial between multielectrode recording array-isolated minicolumnar pairs of neurons located in parallel in layers 2/3 and layer 5 of pFC. The functional significance of individual pFC minicolumns (separated by 40 μm) was shown by reduced correlated firing between cell pairs within single minicolumns on error trials with inappropriate target selection. To further demonstrate dependence on performance, a task-disrupting drug (cocaine) was administered in the middle of the session, which also reduced interlaminar firing in minicolumns that fired appropriately in the early (nondrug) portion of the session. The results provide a direct demonstration of task-specific, real-time columnar processing in pFC indicating the role of this type of microcircuit in executive control of decision-making in primate brain.