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At least 1,639 records · Page 91Linked to original sources
PubMed2007

Observation of an unusually facile fragmentation pathway of gas-phase peptide ions: a study on the gas-phase fragmentation mechanism and energetics of tryptic peptides modified with 4-sulfophenyl isothiocyanate (SPITC) and 4-chlorosulfophenyl isocyanate (SPC) and their 18-crown-6 complexes.

Various peptide modifications have been explored recently to facilitate the acquisition of sequence information. N-terminal sulfonation is an interesting modification because it allows unambiguous de novo sequencing of peptides, especially in conjunction with MALDI-PSD-TOF analysis; such modified peptide ions undergo fragmentation at energies lower than those required conventionally for unmodified peptide ions. In this study, we systematically investigated the fragmentation mechanisms of N-terminal sulfonated peptide ions prepared using two different N-terminal sulfonation reagents: 4-sulfophenyl isothiocyanate (SPITC) and 4-chlorosulfophenyl isocyanate (SPC). Collision-induced dissociation (CID) of the SPC-modified peptide ions produced a set of y-series ions that were more evenly distributed relative to those observed for the SPITC-modified peptides; y(n-1) ion peaks were consistently and significantly larger than the signals of the other y-ions. We experimentally investigated the differences between the dissociation energies of the SPITC- and SPC-modified peptide ions by comparing the MS/MS spectra of the complexes formed between the crown ether 18-crown-6 (CE) and the modified peptides. Upon CID, the complexes formed between 18-crown-6 ether and the protonated amino groups of C-terminal lysine residues underwent either peptide backbone fragmentation or complex dissociation. Although the crown ether complexes of the unmodified ([M + CE + 2H]2+) and SPC-modified ([M* + CE + 2H]2+) peptides underwent predominantly noncovalent complex dissociation upon CID, the low-energy dissociations of the crown ether complexes of the SPITC-modified peptides ([M' + CE + 2H]2+) unexpectedly resulted in peptide backbone fragmentations, along with a degree of complex dissociation. We performed quantum mechanical calculations to address the energetics of fragmentations observed for the modified peptides.

Benzenesulfonates↗
PubMed1991

High-performance liquid chromatographic determination of 3-hydroxykynurenine with fluorimetric detection; comparison of preovulatory phase and postovulatory phase urinary excretion.

A high-performance liquid chromatographic assay for 3-hydroxykynurenine in human urine is described. A fluorescent derivative of 3-hydroxykynurenine was prepared, based on the reaction of the compound with p-toluenesulphonyl chloride in a basic medium. The analytical method for the measurement of the fluorescent compound employed a Tosoh ODS 80 column eluted with 10 mM potassium dihydrogenphosphate (pH 4.5) and acetonitrile (3:2, v/v) and detection at an excitation wavelength of 375 nm (10 nm bandpass) and an emission wavelength of 455 nm (10 nm bandpass). The column temperature was maintained at 25 degrees C. The detection limit was 3 pmol (673 pg) at a signal-to-noise ratio of 5:1. The fluorescent derivative of 3-hydroxykynurenine was eluted at ca. 12.5 min. The technique was applied to the analysis of human urine. The total analysis time was ca. 15 min.

Adult↗
PubMed2005

Phase II trial of thalidomide for advanced and recurrent gynecologic sarcoma: a brief communication from the New York Phase II consortium.

OBJECTIVE: To define the efficacy of thalidomide on the overall survival of patients with metastatic recurrent gynecologic sarcomas. PATIENTS AND METHODS: All patients with sarcoma or carcinosarcoma of gynecologic origin and documented recurrence or persistence of disease after appropriate surgery, radiation therapy and/or chemotherapy were recruited to the study. All patients were ambulatory and had measurable disease that could be documented on CT scan. Patients were started on 200 mg/day of thalidomide orally every night and escalated by 100-200 mg every 7 to 14 days. The length of the treatment was separated into 2 cycles with the first 84 days defined as the first cycle and the next 56 days as the second cycle. Common Toxicity Criteria were used to record toxicities. Because thalidomide was postulated to induce cytostasis, the end-points were progression-free and overall survival in this mixed group of patients. RESULTS: Seventeen patients were enrolled. The drug was not well tolerated because of constipation, fatigue, worsening performance status, drowsiness and sleepiness. The total dosage of medication given to each patient ranged from 3200 mg to 40,500 mg. The maximum dosage reached in each patient ranged from 300 mg to 750 mg, with the total time of treatment ranging from 13 to 99 days. All patients had progression of disease with a median progression-free survival time of 1.84 months (CI 1.54-2.79 months) and a median overall survival of 6.64 months. DISCUSSION: Thalidomide has no activity in patients with advanced or recurrent gynecologic sarcomas and was not well-tolerated. The overall survival was <7 months. The progression-free survival was <3 months, and, since the therapy was not tolerated well, we unanimously decided to close the study at this point. Despite the poor result, we still believe in the strategy of anti-angiogenesis and will continue to pursue other potential treatment options using the same concept.

Administration, Oral↗
PubMed2005

Solid-phase and solution-phase syntheses of oligomeric guanidines bearing peptide side chains.

[reaction: see text] Synthetic strategies for preparing N,N'-bridged oligomeric guanidines bearing peptide side chains both on solid support and in solution are presented. Monomers are prepared from common alpha-amino acids and therefore contain conventionally protected peptide side chains. The side chains include alkyl, aromatic, hydroxyl, amino, carboxylic acid, and amide functional groups. Oligomer elongation utilizes acid-sensitive sulfonyl activated thiourea through the formation of carbodiimide intermediate. With proper preparation of monomers, synthesis of oligomer can be performed in two directions (equivalent to N to C terminal or C to N terminal in a peptide sequence) with excellent efficiency.

Chromatography, Liquid↗
PubMed1999

Phase I and subsequent phase II study of filgrastim (r-met-HuG-CSF) and dose intensified cyclophosphamide plus epirubicin in patients with non-Hodgkin's lymphoma and advanced solid tumors.

BACKGROUND: To define a maximum tolerated dose (MTD) for the combination of epirubicin and cyclophosphamide with filgrastim (r-met-HuG-CSF) in patients with advanced solid tumors and non-Hodgkin's lymphoma (NHL). PATIENTS AND METHODS: Thirty-five patients with advanced solid tumors were enrolled in stages I and II. Twenty-one patients were treated in stage I in sequential cohorts of at least three patients at increasing dosage levels of cyclophosphamide and epirubicin, for up to six cycles every 21 days. At the completion of stage I, a MTD for epirubicin was established. Fourteen patients were treated in stage II, in cohorts of three or more. The epirubicin dose remained constant at the MTD dosage from stage I. Cyclophosphamide was further dose-escalated to establish its MTD. Twenty-one patients with previously untreated non-Hodgkin's lymphoma were treated in stage III with the MTD established in the prior stages. RESULTS: The MTD in stage I was epirubicin 150 mg/m2 and cyclophosphamide 1500 mg/m2 with cumulative neutropenia as the dose-limiting toxicity (DLT). Cumulative thrombocytopenia prevented further dose-escalation of cyclophosphamide in stage II. The stage III regimen consisted of six, 21-day cycles of epirubicin 150 mg/m2, cyclophosphamide 1500 mg/m2, vincristine 2 mg, and prednisolone 100 mg for five days with filgrastim support. Nineteen of twenty-one patients (90%) completed six cycles of treatment, eight (38%) without dose reduction. Common toxicity criteria (CTC) grade 4 neutropenia (neutrophil nadir < 0.5 x 10(9)/l) was documented in 85 of 118 cycles (72%). Neutropenic fever was documented in 17 of 21 patients (81%) on at least one occasion. Severe thrombocytopenia (< 25 x 10(9)/l) was seen in fourteen of 118 cycles (12%) and increased with cycle number. There was no significant non-hematological toxicity. CONCLUSION: Significant dose-escalation of epirubicin and cyclophosphamide was possible with filgrastim support. The MTD achieved was approximately double that of standard-dose therapy. This study forms the basis of an ongoing randomized study evaluating dose-intensification in intermediate grade NHL.

Adult↗
PubMed1998

Phase II trial of uracil/tegafur (UFT) plus leucovorin in patients with advanced pancreatic carcinoma: a University of Chicago phase II consortium study.

BACKGROUND/OBJECTIVES: Uracil and tegafur in a 4:1 molar concentration ratio (UFT; Bristol-Myers Squibb, Wallingford, CT) has broad anti-tumor activity for cancers arising from the gastrointestinal tract. However, there are no published data regarding the efficacy of leucovorin-modulated UFT in patients with pancreatic cancer. The objective of this trial was to determine the activity and evaluate the toxicity of UFT plus oral calcium leucovorin in patients with advanced pancreatic adenocarcinoma. PATIENTS AND METHODS: Fourteen patients with advanced measurable adenocarcinoma of the pancreas were enrolled onto the trial. Patients received 300 mg/m2/d UFT plus 90 mg/d leucovorin administered orally in divided doses every eight hours for 28 days repeated every 35 days. Objective tumor response was evaluated after two courses of therapy. RESULTS: Fourteen patients were evaluable for response and toxicity. No objective responses were seen. The median (range) time to progression and survival were 14 (1.6-37), and 15 (1.9-62) weeks, respectively. Toxicity was mild with severe (grade 3 or 4) hyperbilirubinemia, pain, diarrhea, transaminitis, venous thrombus, weakness, renal failure, confusion, and edema/ascites seen in three (21%), one (7%), two (14%), one (7%), one (7%), one (7%), one (7%), one (7%), and two (14%) patients, respectively. CONCLUSION: In the 14 patients evaluable, UFT 300 mg/m2/d plus oral leucovorin 90 mg/d administered for 28 days did not demonstrate anti-tumor activity against advanced pancreatic adenocarcinoma; however, this oral regimen was well tolerated and devoid of neutropenia, significant oral mucositis or diarrhea.

Adenocarcinoma↗
PubMed1998

Diagnostic relevance of interleukin pattern, acute-phase proteins, and procalcitonin in early phase of post-ERCP pancreatitis.

Post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis has been suggested as a model for acute pancreatitis (AP), which allows evaluation of early alterations in the time course of the disease. The influence of the clinical course on procalcitonin (PCT), serum amyloid A (SAA), and several proinflammatory and inhibitory cytokines was evaluated in patients with AP following ERCP. Blood samples were prospectively collected from patients undergoing ERCP. The incidence of ERCP-induced pancreatic damage, defined as abdominal complaints, a threefold increase of serum lipase, and elevation of CRP from <10 to >20 mg/liter was 12.8% (12/94). Only mild clinical courses of acute pancreatitis were observed. PCT significantly increased in subjects with post-ERCP pancreatitis after 24 hr. However, PCT levels did not exceed 0.5 ng/ml in any patient. Interleukin-1 receptor antagonist (IL-1RA) began to differ from baseline 2 hr after ERCP, followed by interleukin-6 (IL-6, 6 hr), solubilized tumor necrosis factor-alpha receptor II (sTNF-alphaRII, 24 hr) and SAA (24 hr). Interleukin 10 (IL-10) showed marked interindividual variations with no obvious peak. Among all parameters evaluated, only peak values of IL-6 and IL-10 showed significant correlations with the reported pain score (r2 = 0.62/0.78), degree of ampullar irritation (r2 = NS/0.87), and the duration of ERCP (r2 = 0.58/0.76). No correlation was found with the volume of the injected contrast agent. We conclude that IL-10 and IL-6 appear to be useful to monitor patients after ERCP. The absence of any PCT elevation in the present study is in accordance with the clinical course of the patients who suffered from mild pancreatic damage without systemic or infectious complications.

Acute Disease↗
PubMed2003

Perspectives on the treatment of chronic phase and advanced phase CML and Philadelphia chromosome positive ALL(1).

Chronic myeloid leukaemia (CML) is a malignant disease of the bone marrow characterised by the presence of the Philadelphia (Ph) chromosome. About 20% of acute lymphoblastic leukaemia (ALL) patients also show this genetic abnormality. A new drug, imatinib (Glivec, Novartis Pharma AG, Basel, Switzerland, and formerly STI571) is having a profound effect on the treatment and management of all stages of CML and Philadelphia chromosome positive (Ph+) ALL. New treatment algorithms are being developed. Should imatinib replace or be combined with existing therapies? To address this question, we review the pros and cons of therapy with interferon-alpha (IFN-alpha), allogeneic transplantation, autologous transplantation, imatinib, and in the case of Ph+ ALL, chemotherapy and experimental approaches. Conservative and aggressive treatments will be discussed and new molecular methods of monitoring cytogenetic response and their significance will also be reviewed.

Antineoplastic Agents↗