Carbon monoxide releasing molecule-2 improves protamine-mediated hypocoagulation/hyperfibrinolysis in human plasma in vitro.

BACKGROUND: Protamine sulfate has been implicated as a possible cause of coagulopathy for over 20 y. Protamine has been demonstrated to decrease thrombin activity and to prolong bleeding. We tested the hypothesis that a new hemostatic agent, carbon monoxide releasing molecule-2 (tricarbonyldichlororuthenium (II) dimer; CORM-2), could attenuate protamine-mediated hypocoagulation/hyperfibrinolysis in plasma. METHODS: Normal plasma was exposed to 0, 12.5, 25, or 50 µg/mL of protamine, with or without addition of 100 µM CORM-2. Tissue factor was used to initiate coagulation, and tissue type plasminogen activator was added in some experiments. Additional experiments were performed wherein plasma was exposed to protamine combined with 0% or 30% dilution with normal saline, with or without CORM-2 addition. Thrombelastography was performed until either stable clot strength or clot lysis occurred. RESULTS: Protamine, in a concentration-dependent fashion, significantly prolonged the onset of coagulation, decreased the velocity of thrombus growth, and decreased clot strength in the absence or presence of tissue type plasminogen activator. Further, protamine significantly decreased the time to onset of fibrinolysis and decreased clot lysis time. CORM-2 exposure significantly diminished all aforementioned protamine-mediated effects on coagulation and fibrinolysis. Lastly, CORM-2 addition significantly increased the velocity of clot growth and strength in diluted, protamine-exposed plasma. CONCLUSIONS: CORM-2 attenuated protamine-mediated hypocoagulation/hyperfibrinolysis at clinically encountered concentrations. Additional preclinical investigation is warranted to determine if CORM-2 administration will be efficacious in diminishing coagulopathy caused by protamine.

Fibrinogen is a heme-associated, carbon monoxide sensing molecule: a preliminary report.

The objective of this study was to determine how carbon monoxide directly modifies fibrinogen utilizing liquid chromatography-mass spectrometry (LC-MS/MS) by examining fibrinogen exposed to carbon monoxide releasing molecule-2 [tricarbonyldichlororuthenium (II) dimer; CORM-2]. Purified fibrinogen was exposed to 0, 25, 50 or 100 µmol/l CORM-2 for 5 min at 37°C and then stored at -80°C before analyses with LC-MS/MS. In a second series of experiments, normal plasma was exposed to 0 or 100 µmol/l CORM-2 in the absence or presence of the nitric oxide donor sodium nitroprusside and hydroquinone (an organic reductant) to compete with carbon monoxide binding to a putative heme group found on fibrinogen. Coagulation was activated with tissue factor (n=8 per condition). Thrombus growth was monitored with thrombelastography for 15 min. LC-MS/MS did not detect any direct modifications of amino acids in fibrinogen, but detection of small regions of both the alpha and gamma chains was lost following exposure to CORM-2 and endoproteinase digestion with trypsin and Glu-C. An ion with the same m/z and expected retention time as heme was found in the purified fibrinogen. Exposure of plasma to nitric oxide/hydroquinone significantly decreased CORM-2-mediated enhancement of coagulation without affecting the coagulation kinetics of plasma not exposed to CORM-2. Carbon monoxide derived from CORM-2 likely modifies fibrinogen via modulation of a fibrinogen-associated heme group(s). Whereas the precise molecular location of heme attachment and three-dimensional conformational change secondary to carbon monoxide exposure remain to be determined, fibrinogen appears to be a carbon monoxide sensing molecule.

Carbon monoxide releasing molecule-2 enhances α2-antiplasmin activity.

The objective of this study was to determine whether carbon monoxide releasing molecule (tricarbonyldichlororuthenium (II) dimer, CORM-2) directly affects α2-antiplasmin activity. For this purpose, purified α2-antiplasmin was exposed to 0 or 100 µmol/l CORM-2 for 5 min at 37°C and then placed in α2-antiplasmin-deficient plasma (25 µg/ml α2-antiplasmin and 3.3 µmol/l CORM-2 final concentrations). In a second series of experiments, α2-antiplasmin and deficient plasma were combined and then exposed to 0 or 100 µmol/l CORM-2. Coagulation was activated with tissue factor and fibrinolysis initiated with tissue-type plasminogen activator (n = 8 per condition). Thrombus growth/disintegration kinetics were monitored with thrombelastography until clot lysis time occurred. Samples containing α2-antiplasmin preexposed to 100 µmol/l CORM-2 demonstrated no changes in the velocity of clot growth, but had a significant prolongation of the time to maximum rate of lysis, clot lysis time, and a significant decrease in the maximum rate of clot lysis compared with samples preexposed to 0 µmol/l CORM-2. In sharp contrast, addition of 100 µmol/l CORM-2 to premixed α2-antiplasmin in its deficient plasma resulted in significant, marked increases in the velocity of clot growth and the strength with concurrent antifibrinolytic effects as in the first series. In conclusion, CORM-2 exerts its antifibrinolytic effects by direct enhancement of α2-antiplasmin activity. It appears that combined modification of both fibrinogen and α2-antiplasmin are responsible for the robust procoagulant/antifibrinolytic effects of CORM-2 in the fibrinolytic environment.

Carbon monoxide releasing molecule-2 improves coagulation in patient plasma in vitro following cardiopulmonary bypass.

The objective of the present study was to determine if a new procoagulant molecule, carbon monoxide releasing molecule (tricarbonyldichlororuthenium (II) dimer; CORM-2) would improve coagulation following cardiopulmonary bypass (CPB). Plasma was obtained from patients undergoing elective cardiac surgery requiring CPB. Whole blood was collected and anticoagulated with sodium citrate after induction of anesthesia and again after CPB and heparin neutralization with protamine. Blood samples were centrifuged for 15 min, with plasma collected and stored at -80°C prior to analysis. Samples were subsequently exposed to 0 or 100 µmol/l CORM-2, with coagulation activated with tissue factor. Data were collected with thrombelastography until clot strength stabilized. Patients underwent CPB for 133 ± 61 min (mean ± SD). The velocity of thrombus formation was significantly decreased (52%) by CPB, as was clot strength (53%). Addition of CORM-2 to plasma samples obtained after CPB significantly increased the velocity of clot formation (75%) and strength (52%) compared to matched unexposed samples. The lesion of plasmatic coagulation associated with CPB was significantly improved in vitro by addition of CORM-2. If preclinical assessments of efficacy and safety of CORM-2 are favorable, future clinical trials involving CORM-2 or other CORMs as a hemostatic intervention in the setting of CPB are justified.

Carbon monoxide releasing molecule-2 enhances coagulation and attenuates fibrinolysis by two mechanisms: insights gained with colloid dilution.

Carbon monoxide releasing molecule-2 (CORM-2, tricarbonyldichlororuthenium (II) dimer) enhances coagulation and attenuates vulnerability to fibrinolysis. Our goal was to further define the CORM-2-mediated mechanisms using colloids with known effects on coagulation/fibrinolytic proteins. Plasma diluted 0 or 30% with 0.9% NaCl, 5% human albumin, low molecular weight hydroxyethyl starch (130 kDa) or high molecular weight hydroxyethyl starch (450 kDa) was exposed to 0 or 100 µmol/l CORM-2 before activation with tissue factor (n = 8 per condition). A second identically diluted series of experiments were performed with the addition of tissue-type plasminogen activator. Thrombelastographic data were collected until clot strength stabilized or clot lysis occurred. Dilution resulted in fluid-specific decreases in velocity of clot growth, strength and clot growth time with progressive increases in macromolecule size. CORM-2 exposure significantly increased the velocity of clot formation and strength (thin fibrin fiber promoting), but not clot growth time, under all conditions. Fibrinolysis was enhanced to the greatest extent by hydroxyethyl starch (antiα2-antiplasmin effect), and CORM-2 addition attenuated fibrinolysis in all conditions (α2-antiplasmin enhancement). CORM-2 exposure attenuated the decrease in coagulation kinetics mediated by hemodilution by two different mechanisms based on kinetic profile differences between the diluents tested. Further laboratory-based investigation is warranted to further define the molecular mechanisms responsible for CORM-2-mediated effects on coagulation and fibrinolysis.

Dose-related levetiracetam-induced reticulated drug eruption.

Cutaneous drug eruptions are to antiepileptic drugs (AEDs) used for seizure prophylaxis can range from a maculopapular eruption to severe Stevens-Johnson syndrome or toxic epidermal necrolysis. The aromatic drugs: phenytoin, carbamazepine, oxcarbazepine, phenobarbital, primidone, zonisamide and lamotrigine are the most common offenders. In contrast, the second generation AEDs like valproate, topiramate, gabapentin, tiagabine and levetiracetam are rarely associated with a rash. Doses of AEDs are often started low and gradually increased to decrease the risk of allergic reactions. Herein, the authors report a 46-year-old woman with malignant brain tumor, who developed a levetiracetam induced dose-related reticular eruption only after the initial post-operative dose 500 mg twice a day was increased to 1000 mg twice a day, and upon re-challenge when the slower titrated levetiracetam dose reached 750 mg twice a day.

Symptomatic treatment of idiopathic and rosacea-associated cutaneous flushing with propranolol.

Flushing has been associated with medications, rosacea, menopause, carcinoid syndrome, pheochromocytoma, polycythemia, and mastocytosis, although it can occur without known cause. There are no known specific treatments available, but beta-blockers have suppressed flushing reactions in some patients, particularly when associated with anxiety. The medical histories and clinical characteristics of 9 patients with either idiopathic flushing or flushing associated with rosacea were reviewed. Eight patients experienced subjective improvement with propranolol therapy.

Cyclosporine controls epidermolysis bullosa acquisita co-occurring with acquired factor VIII deficiency.

BACKGROUND: Epidermolysis bullosa acquisita (EBA) is a rare antibody-mediated autoimmune blistering disease of adults. Likewise, acquired factor VIII deficiency is a rare antibody-mediated disease of adulthood. Both diseases can be exceedingly difficult to treat and refractory to immunomodulatory therapies. METHODS: Herein, we report a challenging case of EBA and acquired factor VIII deficiency in the same patient. RESULTS: Cyclosporine 4 mg/kg/day rapidly controlled both disease processes after the patient failed to respond to prednisone, colchicine, and pulse cyclophosphamide. The EBA relapsed when the cyclosporine was decreased to 2 mg/kg/day and the patient wore snuggly fitting new shoes, but it cleared quickly when the dose was increased. Cyclosporine has since been decreased gradually to 1.5 mg/kg/day without relapse of either condition or detectable side-effects. CONCLUSIONS: Cyclosporine should be considered when EBA and/or acquired factor VIII deficiency fail to respond to conservative therapy. Both conditions usually respond rapidly to cyclosporine 4-6 mg/kg/day.

Case report: verapamil-induced subacute cutaneous lupus erythematosus.

Calcium-channel blockers (CCB), including verapamil, nifedipine, and diltiazem, are one of the most widely prescribed class of drugs in the treatment of cardiovascular disease. In the last several years, CCBs have been linked with a distinct cutaneous subset in the lupus spectrum, subacute cutaneous lupus erythematosus (SCLE), and we describe a case induced by verapamil.

Carcinoma en cuirasse presenting as keloids of the chest.

BACKGROUND: Carcinoma en cuirasse is a form of metastatic cutaneous breast malignancy occurring most commonly on the chest as a recurrence of breast cancer, but it can be the primary presentation. OBJECTIVE: To discuss the clinical features of carcinoma en cuirasse that distinguish it from hypertrophic scars and keloids of the chest. METHOD: We report a 63-year-old woman with primary cutaneous breast carcinoma presenting as keloid nodules on the chest that failed treatments for keloids. Biopsy revealed a pattern of breast carcinoma in the skin. RESULTS: After further workup, no tumor was found in the deep breast tissue, but metastases were found in her axillary lymph nodes. CONCLUSIONS: Unusual keloid-like nodules or scars on the chest that fail to respond to therapy may be primary or metastatic malignancies, and adequate histologic verification should be obtained to avoid delay in the proper treatment.

Fatal interstitial pulmonary fibrosis in anti-Jo-1-negative amyopathic dermatomyositis.

Amyopathic dermatomyositis (DM) describes a subpopulation with the cutaneous eruption of DM, but without muscle involvement. Interstitial pulmonary fibrosis is a recognized complication of DM, often correlated with antisynthetase enzymes, such as anti-Jo-1. We describe a case of fatal IPF in a patient with anti-Jo-1 antibody-negative amyopathic DM.

Superficial gyrate erythema as a cutaneous reaction to alendronate for osteoporosis.

Alendronate is a bisphosphonate compound used to treat diseases of pathologic bone resorption. Cutaneous reactions to this medication are rare. We report the case of a superficial gyrate erythema that occurred as a reaction to weekly alendronate therapy used in the treatment of postmenopausal osteoporosis.

Cutaneous involvement of dermatomyositis can respond to Dapsone therapy.

BACKGROUND: Dapsone (4,4-diaminodiphenylsulfone) is a sulfone antibiotic used in the treatment of leprosy, but dermatologists more commonly utilize its anti-inflammatory properties particularly directed against leukocytes to treat various bullous disorders, erythema nodosum, pyoderma gangrenosum, Sweet's syndrome, cutaneous vasculitis, and cutaneous forms of lupus erythematosus. The cutaneous manifestations of dermatomyositis are often resistant to antimalarial and immunosuppressive therapies. METHODS: Two patients with cutaneous dermatomyositis unresponsive to combination therapy with prednisone, hydroxychloroquine, quinacrine, and immunosuppressive medications had Dapsone added to their therapy. RESULTS: Both patients showed rapid improvement with the addition of Dapsone. Each had an exacerbation of their cutaneous dermatomyositis on Dapsone with withdrawal and subsequent improvement when the Dapsone was reinstituted. CONCLUSIONS: Dapsone therapy for cutaneous dermatomyositis may have a wider role in treatment for these patients refractory to prednisone and antimalarial therapy.