Co‐administration of l‐cystine and l‐theanine enhances efficacy of influenza vaccination in elderly persons: Nutritional status‐dependent immunogenicity

Aim: The immune response to influenza vaccine is attenuated in elderly persons, though they are at greatest risk for morbidity and mortality by influenza virus infection. Experimental studies demonstrate that co‐administration of l ‐cystine and l ‐theanine enhanced antigen‐specific production of immunoglobulin in aged mice infected with influenza virus. We thus investigated the effect of l ‐cystine and l ‐theanine on antibody induction by influenza vaccines in elderly persons. Methods: Residents in a nursing home were randomly allocated to l ‐cystine and l ‐theanine (n = 32) or placebo (n = 33). The test substances were administered p.o. for 14 days before immunization. Serum influenza virus antibody titers were measured before and 4 weeks after vaccination. Results: Vaccination significantly elevated hemagglutination inhibition (HI) titers for all the three strains of influenza viruses (A/New Caledonia [H1N1], A/New York [H3N2] and B/Shanghai) in both groups. HI titers after vaccination were not significantly different between the two groups for either strain. Also, the seroconversion rate was not significantly different between the two groups in the aggregate. A stratified analysis showed that the rate of seroconversion was significantly greater in the l ‐cystine and l ‐theanine group compared with the placebo group for influenza virus A (H1N1) among subjects with low serum total protein (63% vs 10%, P < 0.05) or low hemoglobin (71% vs 9%, P < 0.05). Conclusion: Co‐administration of l ‐cystine and l ‐theanine before vaccination may enhance the immune response to influenza vaccine in elderly subjects with low serum total protein or hemoglobin.     

Melatonin interactions with blood pressure and vascular function during l‐NAME‐induced hypertension

Abstract: The mechanisms responsible for the antihypertensive effect of melatonin are not completely understood. To elucidate the possible role of the nitric oxide (NO) pathway in the hemodynamic actions of melatonin, the effects of this indolamine on vascular function during hypertension induced by the NO‐synthase (NOS) inhibitor, N^ω‐nitro‐l ‐arginine‐methyl ester (l ‐NAME) were investigated. Four groups of male adult Wistar rats were employed: control, L‐NAME (40 mg/kg), melatonin (10 mg/kg) and l ‐NAME + melatonin for 5 wks. Systolic and diastolic blood pressure were measured invasively in the carotid artery. Conjugated dienes concentration (an oxidative load marker), NOS RNA expression and its activity and RNA expression of cyclooxygenase‐(COX)‐1 and COX‐2 were determined in the aorta. Acetylcholine‐induced responses and their NO‐mediated component were evaluated in femoral and mesenteric artery. Moreover, endothelium‐derived constricting factor (EDCF)‐dependent vasoconstriction and inner diameter were determined in the femoral artery. Chronic l ‐NAME treatment induced hypertension, elevated the oxidative load and inhibited NOS activity. Moreover, impaired NO‐dependent relaxation, augmented EDCF‐constriction, increased COX‐2 expression and reduced arterial inner diameter were observed. Melatonin added to l ‐NAME treatment completely prevented elevation of the oxidative load in the aorta. However, melatonin was not able to prevent NOS activity decline, elevation of COX‐2 expression or the impairment of vascular responses (except moderate improvement in relaxation of small mesenteric arteries) and it exerted only slight antihypertensive effect. In conclusion, in addition to the reduction of the oxidative load, the restoration of the NO pathway seems to play an important role in the antihypertensive effect of melatonin.     

Hematologic,biochemical, and cardiopulmonary effects of l‐arginine supplementation or phosphodiesterase 5 inhibition in patients with sickle cell disease who are on hydroxyurea therapy

Objectives: Fetal hemoglobin (HbF) induction involves NO‐cGMP signaling pathways. l ‐arginine, an NO precursor, and the phosphodiesterase (PDE) 5 inhibitor sildenafil, which potentiates cGMP, were studied in adults with sickle cell disease (SCD) who were stably on HU. Methods: Twenty four courses of l ‐arginine (0.1–0.2 g/kg divided TID) or sildenafil (25–100 mg TID), assigned based on gender due to concerns about sildenafil‐related priapism, were successfully completed. Biochemical assays, pulmonary pressures, and cardiopulmonary exercise capacity are reported from patients in whom serial values are available. Hematologic responses are reported in 14 subjects with HbSS who had stable baseline HbF levels. Results: l ‐arginine increased plasma arginine and ornithine, but not citrulline, suggesting diversion by plasma arginase from NO, and citrulline, generation. Glutathione increased only in patients on l ‐arginine. Sildenafil increased plasma cGMP and citrulline, but not other amino acids. Pulmonary pressures and 6‐min walk distances improved only in patients on sildenafil. In subjects with stable baseline HbF levels, HbF levels changed little from a normalized baseline on l ‐arginine, decreasing by 2.9 ± 16.1%, n = 6; P = n.s., but increased on sildenafil, by 7.5 ± 11.7%, n = 8, P < 0.05. Absolute reticulocyte counts initially decreased in patients on sildenafil. Conclusions: l ‐arginine, at doses that increase plasma arginine levels, altered redox potential in red cells. The lack of clinically detectable efficacy of l ‐arginine may be due to increased arginine metabolism in SCD patients. In vivo augmentation of the cyclic nucleotide pathway by PDE inhibition may induce HbF slightly, but strikingly improves hemodynamic and functional status in SCD.     

l‐Methionine anti‐biofilm activity against Pseudomonas aeruginosa is enhanced by the cystic fibrosis transmembrane conductance regulator potentiator,ivacaftor

Background

Biofilms may contribute to refractory chronic rhinosinusitis (CRS), as they lead to antibiotic resistance and failure of effective clinical treatment. l ‐Methionine is an amino acid with reported biofilm‐inhibiting properties. Ivacaftor is a cystic fibrosis transmembrane conductance regulator (CFTR) potentiator with mild antimicrobial activity via inhibition of bacterial DNA gyrase and topoisomerase IV. The objective of this study was to evaluate whether co‐treatment with ivacaftor and l ‐methionine can reduce the formation of Pseudomonas aeruginosa biofilms.

Methods

P aeruginosa (PAO‐1 strain) biofilms were studied in the presence of l ‐methionine and/or ivacaftor. For static biofilm assays, PAO‐1 was cultured in a 48‐well plate for 72 hours with stepwise combinations of these agents. Relative biofilm inhibitions were measured according to optical density of crystal violet stain at 590 nm. Live/dead assays (BacTiter‐Glo? assay, Promega) were imaged with laser scanning confocal microscopy. An agar diffusion test was used to confirm antibacterial effects of the drugs.

Results

l ‐Methionine (0.5 μM) significantly reduced PAO‐1 biofilm mass (32.4 ± 18.0%; n = 4; p < 0.001) compared with controls. Low doses of ivacaftor alone (4, 8, and 12 μg/mL) had no effect on biofilm formation. When combined with ivacaftor (4 μg/mL), a synergistic anti‐biofilm effect was noted at 0.05 μM and 0.5 μM of l ‐methionine (two‐way analysis of variane, p = 0.0415) compared with corresponding concentrations of l ‐methionine alone.

Conclusion

Ivacaftor enhanced the anti‐biofilm activity of l ‐methionine against the PAO‐1 strain of P aeruginosa. Further studies evaluating the efficacy of ivacaftor/l ‐methionine combinations for P aeruginosa sinusitis are planned.

     

Activity and safety of combination chemotherapy with methotrexate,ifosfamide, l‐asparaginase and dexamethasone (MILD) for refractory lymphoid malignancies: a pilot study

Optimal salvage chemotherapy has not been established for lymphoid malignancy, which is refractory to the conventional cyclophosphamide, doxorubicin, vincristine, and prednisone regimen. To explore an effective regimen, we conducted a phase I pilot study of combination chemotherapy with methotrexate, ifosfamide, l‐asparaginase and dexamethasone (MILD), which are unaffected by MDR1‐encoded P‐glycoprotein. A total of 18 patients with lethal lymphoid malignancy were enrolled over a 2‐yr period. The median age was 63 yr. Eleven patients had T/NK‐cell malignancies, six had B‐cell malignancies, and one was diagnosed with a blastic plasmacytoid dendritic cell neoplasm. Patients aged ≥60 and <60 yr were planned to receive a set of starting doses of methotrexate and ifosfamide, which should induce myelosuppression. Eleven patients completed two courses of MILD therapy. Treatment‐related death because of systemic mucormycosis was observed in one patient. Major treatment‐related adverse events were grade 3 or more hematologic toxicities, which included lymphopenia corresponding to dose‐limiting toxicity. The most common grade 3 non‐hematologic toxicity was febrile neutropenia. Of the 14 evaluated patients, three achieved a complete response, and four showed a partial response. The overall response rate was 57%. It was very interesting that all of seven responders had T/NK‐cell malignancies. MILD therapy was feasible and presented acceptable toxicity in patients with refractory or lethal lymphoid malignancies. The efficacy for T/NK‐cell malignancies should be further evaluated.     

Effect of combination therapy of hydroxyurea with l‐carnitine and magnesium chloride on hematologic parameters and cardiac function of patients with β‐thalassemia intermedia

Background: l‐Carnitine and magnesium have antioxidant properties. They have the potential to stimulate production of fetal hemoglobin and stabilize the RBC membrane, respectively. Several studies have also shown the beneficial effects of hydroxyurea in thalassemic patients. We assessed the effect of combination therapy of hydroxyurea with l ‐carnitine and magnesium chloride on hematologic parameters and cardiac function of patients with β‐thalassemia intermedia. Methods: One‐hundred‐and‐twenty patients with thalassemia intermedia (range, 4–35 yr; mean, 19 ± 6.4 yr) who had no need for blood transfusion or requirement for blood transfusion with an interval of >6 months were randomly selected. All patients had been on hydroxyurea for >6 months. They were randomly divided into four groups: group A (hydroxyurea alone); group B (hydroxyurea and l ‐carnitine); group C (hydroxyurea and magnesium chloride); and group D (hydroxyurea, l ‐carnitine and magnesium chloride). Results: In groups B, C, and D, mean Hb and hematocrit increased during 6‐month treatment (P < 0.001). Echocardiographic studies revealed a significant decrease in left ventricular end‐diastolic diameter in group B (P = 0.032), increase in pulmonary acceleration time in group C (P = 0.012), and increase in left ventricular ejection fraction in groups C and D (P < 0.000 and 0.006, respectively). Conclusion: Combination of hydroxyurea with l ‐carnitine or magnesium could be more effective in improving hematologic parameters and cardiac status in patients with β‐thalassemia intermedia than hydroxyurea alone.     

A double‐blind,randomized, placebo‐controlled trial of intravenous l‐ornithine–l‐aspartate on postural control in patients with cirrhosis

Introduction: Hepatic encephalopathy (HE) is a complication of liver disease. Several treatments have been introduced but only l ‐ornithine–l ‐aspartate (LOLA) shows proven efficacy. This double‐blind, randomized, placebo‐controlled trial evaluated the effect of LOLA on postural control in cirrhotics. Methods: Forty patients were randomized to either LOLA or a placebo. HE was evaluated by psychometric testing (PSE Syndrome Test) and critical flicker frequency (CFF). Posturography [equilibrium score (ES)] provided information regarding postural control. Peripheral blood was analysed for ammonia concentration (NH₃) and the partial pressure of ammonia (pNH₃). Results: Both groups were comparable regarding baseline variables. Posturography and PSE Syndrome Test improved in both groups; improvement was greater in the LOLA group (ES: 5.3%; PSE: 1.9) compared with the placebo (ES: 3.9%; PSE: 1.3) but did not reach significance (ES: P=0.3; PSE: P=0.5). CFF remained unchanged during treatment and between groups (P=NS). NH₃ decreased in the LOLA group (Δ: ?15 μmol/L) and slightly increased in the placebo group (Δ: 11.1 μmol/L), but the differences did not reach statistical significance (P=0.07). pNH₃ remained largely unchanged (LOLA Δ: ?1.2 × 10^?5 mmHg vs. placebo Δ: ?0.3 × 10^?5 mmHg; P=0.21). Conclusion: In the LOLA group, an improvement of posturographic control and PSE Syndrome Test was observed, but a similar improvement was also achieved by the placebo. In LOLA, ammonia levels tended to decrease while they tended to increase in the placebo group. LOLA might augment the improvement achieved by intravenous fluids alone but a larger cohort will be needed to show this effect with statistical significance.     

Serum concentration of L‐kynurenine predicts the clinical outcome of patients with diffuse large B‐cell lymphoma treated with R‐CHOP

Purpose: Introduction of rituximab has largely improved the prognosis of patients with diffuse large B‐cell lymphoma(DLBCL). Such change in therapeutic outcome necessitates the identification of additional prognostic factors to conventional indexes that have been validated for CHOP without rituximab. Indoleamine 2,3‐dioxygenase (IDO) exerts intense immunomodulatory effects because of enzymatic activities that catalyze the breakdown of the essential amino acid L‐tryptophan. The activity of IDO can be estimated by measuring the serum concentration of L ‐kynurenine. Here, we investigated the role of L ‐kynurenine as a prognostic marker in R‐CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisolone) therapy. Experimental design: Data from 73 consecutive patients treated with eight cycles of R‐CHOP or R‐THP (tetrahydropyranyl adriamycin)‐COP between December 2002 and March 2007 were analyzed. L ‐kynurenine concentrations in serum samples obtained at admission were measured by high‐performance liquid chromatography. Results: The median serum L ‐kynurenine level was 1.575 μm (range 0.537–9.588). The complete response (CR) rates of patients with L ‐kynurenine <1.5 and ≥1.5 μm were 83% and 61%, respectively (P < 0.05). The three‐yr overall survival (OS) rates for patients with L ‐kynurenine <1.5 and ≥1.5 μm were 89% and 58%, respectively (P < 0.005). In addition, higher age, poor performance status, elevated serum lactate dehydrogenase, and unfavorable as well as revised International Prognosis Index were significantly worse factors for CR rate and OS. Multivariate analyses revealed only L ‐kynurenine as an independent prognostic factor for OS. Conclusions: Serum L ‐kynurenine might be a novel prognostic factor to determine the treatment outcome of DLBCL with the R‐CHOP regimen.     

Long‐Term Follow‐Up of Patients with Syncope Evaluated by Head‐Up Tilt Test

Background: Clinicians may be tempted to consider a positive head‐up tilt test (HUTT) an unfavorable prognostic indicator. We investigated whether results of routine HUTT predict long‐term recurrence of syncope. Methods: We analyzed syncope recurrence at long‐term among 107 patients (mean age 51 ± 20 years) receiving HUTT for diagnostic evaluation of unexplained/suspected neurocardiogenic syncope in our Institute. Results: HUTT was positive in 76 patients (vasodepressive response, n = 58; cardioinhibitory, n = 5; mixed, n = 13). During a median follow‐up of 113 months (range, 7–161), 34 (32%) patients experienced recurrence (24 [32%] with positive HUTT during 110 months (7–159); 10 [32%] with negative HUTT during 120 [22–161] months). Actuarial freedom from recurrence at 10 years did not significantly differ for patients with positive/negative test results (after passive/active phases) or with different positive response patterns (vasodepressive, cardioinhibitory, mixed). By contrast, history of >4 syncopes in the 12 months preceding HUTT stratified risk of recurrence, irrespective of HUTT positivity/negativity. At Cox proportional hazards analysis, history of >4 syncopes in the 12 months preceding HUTT was the single independent risk factor for recurrence both in the overall study population (HR, 1.7; 95% CI, 1.07–2.69) and within the subset of patients who tested positive (HR, 1.83; 95% CI, 1.07–3.17). Conclusions: This long‐term follow‐up study reinforces the concept that a positive HUTT should not be considered an unfavorable prognostic indicator; frequency of recent occurrences may be a more valid predictor. Ann Noninvasive Electrocardiol 2010;15(2):101–106     

A Review of HNS‐32: A Novel Azulene‐l‐Carboxamidine Derivative with Multiple Cardiovascular Protective Actions

HNS‐32 [N¹,N¹‐dimethyl‐N²‐(2‐pyridylmethyl)‐5‐isopropyl‐3,8‐dimethylazulene‐1‐carboxamidine] (CAS Registry Number: 186086‐10‐2) is a newly synthesized azulene derivative. Computer simulation showed that its three dimensional structure is similar to that of the class Ib antiarrhythmic drugs, e.g., lidocaine or mexiletine. HNS‐32 potently suppressed ventricular arrhythmias induced by ischemia due to coronary ligation and/or ischemia‐reperfusion in dogs and rats. In the isolated dog and guinea pig cardiac tissues, HNS‐32 had negative inotropic and chronotropic actions, prolonged atrial‐His and His‐ventricular conduction time and increased coronary blood flow. In the isolated guinea pig ventricular papillary muscle, HNS‐32 decreased maximal rate of action potential upstroke (V?_max) and shortened action potential duration (APD). These findings suggest that HNS‐32 inhibits inward Na⁺ and Ca²⁺ channel currents. In the isolated pig coronary and rabbit conduit arteries, HNS‐32 inhibited both Ca²⁺ channel‐dependent and ‐independent contractions induced by a wide variety of chemical stimuli. HNS‐32 is a potent inhibitor of protein kinase C (PKC)‐mediated constriction of cerebral arteries. It is likely to block both, Na⁺ and Ca²⁺ channels expressed in cardiac and vascular smooth muscles. These multiple ion channel blocking effects are largely responsible for the antiarrhythmic and vasorelaxant actions of HNS‐32. This drug may represent a novel approach to the treatment of arrhythmias.     

Evaluation of two,commercial, multi‐dye,nucleic acid amplification technology tests,for HBV/HCV/HIV‐1/HIV‐2 and B19V/HAV,for screening blood and plasma for further manufacture

Background The cobas^® TaqScreen MPX Test, version 2.0, a multiplex, multi‐dye nucleic acid amplification technology (NAT) test from Roche was evaluated by two European Blood Banks, the German Red Cross Blood Donor Service, Frankfurt, Germany and Centro de Hemoterapia y Hemodonación de Castilla y León, Valladolid, Spain. In addition, the cobas^® TaqScreen DPX Test was evaluated for the simultaneous detection and quantitation of parvovirus B19 and the detection of hepatitis A virus (HAV). Study Design and Methods The performances of the two tests were evaluated regarding the analytical sensitivity, the reproducibility of the tests using samples containing low concentrations of each virus and cross‐contamination using samples containing high titres of virus. Results The analytical sensitivity of the MPX Test, version 2.0, obtained by the German Red Cross Blood Donor Service was 1·1, 3·9 and 43·3 IU/ml for HBV, HCV and HIV‐1, respectively. The comparable analytical sensitivity at Centro de Hemoterapia y Hemodonación de Castilla y León was 3·5, 17·6 and 50·6 IU/ml for HBV, HCV and HIV‐1, respectively. The analytical sensitivity of the DPX test determined by the German Red Cross Blood Donor Service was 0·6 and 3·8 IU/ml for HAV and B19. Conclusion These multiplex and multi‐dye blood screening assays represent a flexible NAT screening system for mini‐pools between 6 and 96 samples per pool and fulfil all requirements of the European Pharmacopoeia for HCV and B19V testing of plasma for fractionation. The inclusion of a new multi‐dye technology means discriminatory assays are no longer required for either test thus improving workflow, turn‐around time and minimize the risk of obtaining a reactive result for which the virus cannot be identified.