Tryptophan Column Research Articles

A search for tryptophan in the gas of the IC 348 star cluster of the Perseus molecular cloud

ABSTRACT We have used spectra of the Spitzer Space Telescope to conduct a search for the aromatic amino acid tryptophan in the interstellar gas of the young star cluster IC 348. For all the strongest mid-infrared (mid-IR) laboratory bands of tryptophan, we have found counterpart emission lines in the observed spectrum which are consistent in wavelength and strength with the laboratory measurements. Assuming that the detected emission lines are due to tryptophan and using the measured fluxes, we estimate a tryptophan column density in the line of sight of the core of IC 348 in the range 109–1011 cm−2. The observed emission lines are also found in the combined spectrum of >30 interstellar locations obtained in diverse unrelated star-forming regions observed by Spitzer. This could be an indication that the molecule causing the emission is widespread in interstellar space. Future high spectral resolution mid-IR searches for proteinogenic amino acids in protostars, protoplanetary discs, and in the interstellar medium will be key to study an exogenous origin of meteoritic amino acids and to understand how the pre-biotic conditions for life were set in the early Earth.

Immunoadsorption therapy in refractory heart failure patients with dilated cardiomyopathy: a potential therapeutic option

Removal of cardiac autoantibodies by immunoadsorption might confer clinical improvement in dilated cardiomyopathy. In this pilot study, we investigated the efficacy and safety of immunoadsorption therapy in refractory heart failure patients with dilated cardiomyopathy. This study consisted of 9 heart failure patients with dilated cardiomyopathy, NYHA III-IV, left ventricular ejection fraction <30%, unresponsive to heart failure therapy, and with cardiac autoantibodies. Patients underwent immunoadsorption therapy for five consecutive days using a tryptophan column. Changes in cardiac function (left ventricular ejection fraction, left ventricular end-diastolic diameter, left ventricular end-systolic diameter), exercise capacity (6-minute walk distance), neurohormonal (N-terminal pro-brain natriuretic peptide), proinflammatory (high-sensitive C-reactive protein), and myocardial (cardiac troponin-I), biochemical, and hematological variables were obtained at baseline and after 3 and 6 months of immunoadsorption therapy. Mean left ventricular ejection fraction and 6-minute walk distance significantly increased at 3 months (from 23.27±5.09 to 32.1±1.7%, p=0.01 for left ventricular ejection fraction and from 353±118 to 434±159 m, p=0.04 for 6-minute walk distance) and further increased at 6 months after immunoadsorption therapy (to 34.5±7.7%, p=0.02 for ejection fraction and to 441±136 m, p=0.04 for 6-minute walk distance). NT-proBNP level reduced from 1161(392.8-3034) to 385(116.1-656.5) ng/L (p=0.04), and high-sensitive C-reactive protein decreased from 9.74±0.96 to 4.3±5.8 mg/L (p=0.04) at 6 months. Left ventricular end-diastolic diameter (66.1±5.8 vs. 64.7±8.9 mm) and left ventricular end-systolic diameter (56.1±8.6 vs. 52.3±10.8 mm) tended to decrease but did not reach statistical significance. No significant worsening was observed in creatinine, cardiac troponin-I, and hemoglobin levels after the immunoadsorption procedure. In dilated cardiomyopathy patients with refractory heart failure, immunoadsorption may be considered a potentially useful therapeutic option to improve a patient's clinical status.

Refractory idiopathic thrombocytopenic purpura treated with immunoadsorption using tryptophan column

The treatment of refractory idiopathic thrombocytopenia in adult is a challenge. Here we report successful treatment of an adult ITP patient with immunoadsorption using tryptophan column who were refractory to steroids, splenectomy, eltrombopag and various immunosuppressive medications.

Specific immunoadsorption therapy using a tryptophan column in patients with refractory heart failure due to dilated cardiomyopathy

Certain cardiac-specific autoantibodies found in patients with dilated cardiomyopathy (DCM) play a role in mediating myocardial damage and fatal ventricular arrhythmias resulting in sudden cardiac death. Immunoadsorption therapy (IA) is one of the therapeutic tools to remove such autoantibodies. Clinical studies from Germany have shown that nonspecific IA using columns loaded by sheep antihuman IgG or protein A improved hemodynamic data and affected favorably cardiac function and survival in patients with heart failure (HF) due to DCM. The goal of this study is to determine if IA therapy using the high-profile tryptophan column, which has high affinity for IgG3 subclass, affects favorably cardiac function in patients with severe HF who are refractory to conventional therapy. IA therapy was conducted in 16 patients with DCM (age 53 ± 4, male 8, New York Heart Association functional class III/IV, mean ejection fraction 18 ± 2%). Study subjects had autoantibodies directed against either β1-adrenergic or M2-muscarinic receptors. Plasma brain natriuretic peptide levels were significantly decreased after IA (P = 0.016). Plasma inflammatory cytokines including interleukin-6 and tumor necrosis factor-α did not change after each session of IA. Six-minute walk distance was significantly increased after IA (P = 0.01). Left ventricular ejection fraction increased by 3% 3 months after IA (P = 0.039). Our initial experience demonstrated safety and short-term efficacy of IA using a new IgG3-specific tryptophan column for patients with advanced HF due to DCM. Long-term follow-up is needed to confirm the effects on cardiac function and morbidity/mortality in such patients.

Specific Immunoadsorption Therapy Using a New Tryptophan Column for Patients With Advanced Heart Failure Due to Dilated Cardiomyopathy

Specific Immunoadsorption Therapy Using a New Tryptophan Column for Patients With Advanced Heart Failure Due to Dilated Cardiomyopathy

Elevated bradykinin and decreased carboxypeptidase R as a cause of hypotension during tryptophan column immunoabsorption therapy.

Tryptophan column immunoabsorption therapy is beneficial to the patient with a neuroimmunological disease, but some complications have been attributed to this treatment. There have been some instances of an abrupt shock state along with severe decreases in blood pressure. In regards to this shock state, it has been reported that plasma bradykinin levels increase during tryptophan column immunoabsorption therapy. In this study, we examined the correlation between plasma bradykinin levels and either blood pressure or the levels of its degrading enzymes, angiotensin converting enzyme (ACE) and carboxypeptidase R (CPR) in 6 patients. Increased concentrations of bradykinin were present in the latter half of the therapeutic interval, and plasma bradykinin levels were found to be inversely correlated to CPR activity. The decreased CPR level could augment the activities of bradykinin. We speculate that bradykinin could be responsible for the hypotension occurring in patients during tryptophan column immunoabsorption therapy and that the metabolism of bradykinin could be caused by the decreased activity of CPR.

Pretransplantation immunoadsorption therapy in patients immunized with human lymphocyte antigen: effect of treatment and three years' clinical follow-up of grafts.

Sensitization against human lymphocyte antigen (HLA) occurs frequently in previously transplanted patients that lose a first cadaveric graft. To shorten their time on the waiting list and reduce the incidence of early rejection in such patients, we performed immunoadsorption therapy by a tryptophan column in 10 patients as an attempt to remove circulating antibodies prior to regrafting. Resynthesis of antibodies was suppressed with cyclophosphamide and prednisolone. Following the course of immunoadsorption therapy, the panel reactive antibodies (PRA) decreased by more than 50% from the pretreatment values. In the present study, 8 patients were transplanted with cadaveric renal grafts. At the time of follow-up, graft survival was 63% in these patients (2-36 months post-transplantation, mean 23 months). There was one incidence of acute rejection, one graft was lost within 48 h owing to renal artery thrombosis, and one was lost within 2 weeks as a result of stenosis. The serum creatinine levels were down to near normal during the first 3 weeks in hospital (p < 0.0001) and remained at this level during the period of follow-up. We conclude that immunoadsorption might be a beneficial pretransplantation therapy and an alternative to plasmapheresis in HLA-immunized patients awaiting kidney transplantation.

Semiselective immunoadsorption of anti-AChR abs on tryptophan column in myasthenia gravis. Clinical experience in 32 patients

Semiselective immunoadsorption of anti-AChR abs on tryptophan column in myasthenia gravis. Clinical experience in 32 patients