Natural sunlight NO(3)(-)/NO(2)(-)-induced photo-degradation of phenylurea herbicides in water.

The nitrate-induced photodegradation of phenylureas in water was demonstrated to occur efficiently using natural sunlight irradiation. The kinetics of disappearance was found to be dependent on the inducer and substrate concentrations, the phenylurea structure and the origin and composition of the aqueous matrix including the presence of nitrite. The measured effects under sunlight were of the same order of those measured previously in the lab using our solar light simulated system. However, by-product distribution might differ substantially particularly considering the nitration pathway.

Evaluation of glycosylation and malonylation patterns in flavonoid glycosides during LC/MS/MS metabolite profiling.

Flavonoid conjugates constitute several classes of plant phenolic secondary metabolites including many isomeric compounds differing in the hydroxylation pattern and substitution of their rings with different groups such as alkyls, acyls or sugars. These compounds occur in plant tissues mainly as glycosides and in many cases it is necessary to have reliable and detailed information concerning the structure of these natural products. Our results were obtained using leaf extracts of Arabidopsis thaliana and Lupinus angustifolius in which different glycosides of flavones, flavonols and isoflavones are present. Analysis of collision-induced dissociation (CID)/MS/MS spectra of protonated [M + H](+), sodiated [M + Na](+) or deprotonated [M - H](-) molecules recorded during HPLC runs may bring needed information in this respect. However, registration of mass spectra of [M + Na](+) ions with a good efficiency is possible only after post-column addition of a sodium acetate solution to the LC column eluate. The retention of sodium cation on the saccharidic parts of the molecule is observed after the CID fragmentation. In many cases, the location of this cation on the glycan attached to C-3 hydroxyl group of flavonol led to assignment of its structure. Additionally, the determination of the structure of the aglycone and of the sequence of the glycan part was made possible through the CID data obtained from the [M + H](+) and [M - H](-) ions. CID spectra show a different order of sugar elimination from hydroxyl groups at C-3 and C-7 in flavonol glycosides isolated from A. thaliana leaves and give sufficient information to discriminate flavonoid O-diglycosides from flavonoid di-O-glycosides.

Photo-induced degradation of diuron in aqueous solution by nitrites and nitrates: kinetics and pathways.

The photo-induced degradation of diuron (3-(3,4-dichlorophenyl)-1,1-dimethylurea) in aqueous solution under simulated solar irradiation has been investigated in the presence of NO3-/NO2- ions. The degradation rates were compared by varying environmental parameters including substrate and inducer concentrations, oxygen content and pH. The photoproducts were identified by extensive LC-ESI-MS and LC-ESI-MS-MS studies after SPE preconcentration on prepacked cartridges. In both NO3- and NO2- conditions, oxidation of the N-(CH3)2 terminus group is the main process leading to the N-monodemethylated (NHCH3), N-formyl (N(CH3)CHO) and the uncommon and unstable carbinolamine (N(CH3)CH2OH) by-products. Cl/OH substituted and nitrated phenylureas are formed minorily. Degradation pathways involving OH* and NO2* (or dimer) radicals as reactive species are proposed.

Profiling of flavonoid conjugates in Lupinus albus and Lupinus angustifolius responding to biotic and abiotic stimuli.

Qualitative and quantitative composition of flavonoid and isoflavonoid glycosides as well as free aglycones in lupin seedlings (roots and aerial parts) grown under different light conditions or responding to infection with Pleiochaeta setosa, a fungus causing brown leaf spot, were monitored by liquid chromatography with UV and/or mass spectrometric detection. Both physical and biotic factors affected flavonoid and isoflavonoid levels in lupin tissues. Fungal infection evoked significant increase in the amounts of genistein, 2'-hydroxygenistein, and their prenylated derivatives that are thought to function as lupin phytoalexins. Effect on quantitative changes of glycosylated flavonoids and isoflavonoids in the roots and aerial parts was less significant. Moreover, different light conditions applied during seedling growth caused relative changes of flavonoid and isoflavonoid conjugates composition, especially in the leaves of white lupin plants. The chemical structures of flavonoid and isoflavonoid conjugates present in Lupinus angustifolius were elucidated. In addition to genistein and 2'-hydroxygenistein glycosides, flavonol conjugates were identified in leaves, while the composition of root isoflavonoids was similar to that of L. albus reported earlier.

Ozonation of chlorophenylurea pesticides in water: reaction monitoring and degradation pathways.

The degradation of mono- and dichlorophenylureas under ozone/hydrogen peroxide conditions was investigated in order to establish the effect of the structural parameters. The N-dimethyl phenylureas (mono- and dichloro) appear to differ strongly from the corresponding N-methyl N-methoxy analogues in terms of disappearance of the parent pesticide and evolution of the by-products identified by MS and MS-MS. The degradation rate of the latter is slower by a factor of 2.5 giving rise to additional pathways (hydroxylation of the phenyl ring and carbinolamine intermediate). Experiments with 14C-labelled compounds allow a complete determination of the mass balances obtained after solid-phase-extraction (SPE). This study demonstrates the interest of SPE for reaction monitoring and compares the performances of different types of phases for this purpose used alone or in combination. Mineralisation is also evaluated regarding 14CO2 production and found to contribute up to 20% in the degradation process.

Profiling changes in metabolism of isoflavonoids and their conjugates in Lupinus albus treated with biotic elicitor.

Liquid chromatography with ultraviolet and mass spectrometric detection was applied to monitor changes in profiles of isoflavonoid glycosides and free isoflavonoid aglycones in Lupinus albus L. Four isoflavonoid aglycones, fourteen isoflavonoid glycosides, four flavonol glycosides and flavone glycoside were identified in lupin tissue after LC/ESI/MS analyses. An elicitor preparation from purified yeast cell wall was used to inject the shoots of 3-week old seedlings or to infiltrate the cut lupin leaves. Qualitative and quantitative changes of isoflavonoids were measured at different time points after elicitation. In elicited lupin seedlings increased amounts of prenylated isoflavone aglycones were identified. The concentrations of glycosidic conjugates of isoflavones present in plant tissue were less affected.

Tandem solid-phase extraction of atrazine ozonation products in water.

The preconcentration of aqueous solutions containing atrazine degradation products was investigated using solid-phase extraction on octadecyl and cation-exchanger silica phases. The retention and elution steps were studied and evaluated separately in order to define and optimize the critical experimental parameters involved. A strategy which combines sequentially both phases is proposed to fractionate compounds into two groups of increasing polarities: firstly, the native pesticide, hydroxyatrazine and most chlorotriazines on octadecyl support, and secondly monodealkylated hydroxytriazines, ammeline and ammelide on cation-exchanger. This tandem procedure was successfully applied for analysing and quantifying atrazine ozonation products and its efficiency demonstrated using [U-ring 14C]-labelled atrazine experiments.

Impact of cytokine administration on the generation of antitumor reactivity in patients with metastatic melanoma receiving a peptide vaccine.

Patients with metastatic melanoma were immunized with an immunodominant peptide derived from the gp100 melanoma-melanocyte differentiation Ag that was modified to increase binding to HLA-A+0201. A total of 10 of 11 patients who received the g209-2M peptide alone developed precursors reactive with the native g209 peptide, compared with only 5 of 16 patients who received g209-2M peptide plus IL-2 (p2 = 0.005). Peptide reactivity closely correlated with the recognition of HLA-A+0201 melanoma cells (p < 0. 001). The decrease in immune reactivity when peptide was administered with IL-2 appeared specific for the immunizing peptide, since reactivity to an influenza peptide resulting from prior exposure was not affected. Preexisting antitumor precursors did not decrease when peptide plus IL-2 was administered. The administration of GM-CSF or IL-12 also resulted in a decrease in circulating precursors compared with the administration of peptide alone, though not as great a decrease as that seen with IL-2. Immunization with peptide plus IL-2 did, however, appear to have clinical impact since 6 of the 16 patients (38%) that received peptide plus IL-2 had objective cancer regressions. It thus appeared possible that immunization with peptide plus IL-2 resulted in sequestering or apoptotic destruction of newly activated immune cells at the tumor site. These represent the first detailed studies of the impact of immunization with tumor peptides in conjunction with a variety of cytokines in patients with metastatic cancer.

Prospective randomized trial of the treatment of patients with metastatic melanoma using chemotherapy with cisplatin, dacarbazine, and tamoxifen alone or in combination with interleukin-2 and interferon alfa-2b.

PURPOSE: The combination of chemotherapy with immunotherapeutic agents such as interleukin-2 and interferon alfa-2b has been reported to provide improved treatment results in patients with metastatic melanoma, compared with the use of chemotherapy alone. We have performed a prospective randomized trial in patients with metastatic melanoma, comparing treatment with chemotherapy to treatment with chemoimmunotherapy. PATIENTS AND METHODS: One hundred two patients with metastatic melanoma were prospectively randomized to receive chemotherapy composed of tamoxifen, cisplatin, and dacarbazine or this same chemotherapy followed by interferon alfa-2b and interleukin-2. Objective responses, survival, and toxicity in the two groups were evaluated at a median potential follow-up of 42 months. RESULTS: In 52 patients randomized to receive chemotherapy, there were 14 objective responses (27%), including four complete responses. In 50 patients randomized to receive chemoimmunotherapy, there were 22 objective responses (44%) (P2 = .071), including three complete responses. In both treatment groups, the duration of partial responses was often short, and there was a trend toward a survival advantage for patients receiving chemotherapy alone (P2 = .052; median survival of 15.8 months compared with 10.7 months). Treatment-related toxicities were greater in patients receiving chemoimmunotherapy. CONCLUSION: With the treatment regimens used in this study, the addition of immunotherapy to combination chemotherapy increased toxicity but did not increase survival. The use of combination chemoimmunotherapy regimens is not recommended in the absence of well-designed, prospective, randomized protocols showing the benefit of this treatment strategy.

Immunizing patients with metastatic melanoma using recombinant adenoviruses encoding MART-1 or gp100 melanoma antigens.

BACKGROUND: The characterization of the genes encoding melanoma-associated antigens MART-1 or gp100, recognized by T cells, has opened new possibilities for the development of immunization strategies for patients with metastatic melanoma. With the use of recombinant adenoviruses expressing either MART-1 or gp100 to immunize patients with metastatic melanoma, we evaluated the safety, immunologic, and potential therapeutic aspects of these immunizations. METHODS: In phase I studies, 54 patients received escalating doses (between 10(7) and 10(11) plaque-forming units) of recombinant adenovirus encoding either MART-1 or gp100 melanoma antigen administered either alone or followed by the administration of interleukin 2 (IL-2). The immunologic impact of these immunizations on the development of cellular and antibody reactivity was assayed. RESULTS: Recombinant adenoviruses expressing MART-1 or gp100 were safely administered. One of 16 patients with metastatic melanoma receiving the recombinant adenovirus MART-1 alone experienced a complete response. Other patients achieved objective responses, but they had received IL-2 along with an adenovirus, and their responses could be attributed to the cytokine. Immunologic assays showed no consistent immunization to the MART-1 or gp100 transgenes expressed by the recombinant adenoviruses. High levels of neutralizing antibody were found in the pretreatment sera of the patients. CONCLUSIONS: High doses of recombinant adenoviruses could be safely administered to cancer patients. High levels of neutralizing antibody present in patients' sera prior to treatment may have impaired the ability of these viruses to immunize patients against melanoma antigens.

Sex pheromone of the oleander scale, Aspidiotus nerii: structural characterization and absolute configuration of an unusual functionalized cyclobutane.

The sex pheromone emitted by the female oleander scale, Aspidiotus nerii (Homoptera, Diaspididae), has been isolated and characterized as (1R, 2S)-cis-2-isopropenyl-1-(4'-methyl-4'-penten-1'-yl)cyclobutaneethanol acetate by using advanced MS and NMR spectroscopic methods, as well as a variety of microderivatization sequences. The structure has been confirmed by stereo- and enantioselective synthesis of the four possible stereoisomers. The absolute configuration has been determined by comparison of the activity of the cis (1S,2R) and (1R, 2S) enantiomers with that exhibited by the natural material in greenhouse bioassays and field tests. The structure of this sesquiterpenoid pheromone is new in the coccids and in the pheromone field in general.

Immunologic and therapeutic evaluation of a synthetic peptide vaccine for the treatment of patients with metastatic melanoma.

The cloning of the genes encoding cancer antigens has opened new possibilities for the treatment of patients with cancer. In this study, immunodominant peptides from the gp100 melanoma-associated antigen were identified, and a synthetic peptide, designed to increase binding to HLA-A2 molecules, was used as a cancer vaccine to treat patients with metastatic melanoma. On the basis of immunologic assays, 91% of patients could be successfully immunized with this synthetic peptide, and 13 of 31 patients (42%) receiving the peptide vaccine plus IL-2 had objective cancer responses, and four additional patients had mixed or minor responses. Synthetic peptide vaccines based on the genes encoding cancer antigens hold promise for the development of novel cancer immunotherapies.

Allelic loss on chromosome 13q in human prostate carcinoma.

To clarify the role in prostate tumorigenesis played by loss of the three known or putative tumor suppressor loci on the centromeric portion of chromosome 13q, we examined 80 clinically localized and 15 advanced prostate carcinomas for allelic loss at microsatellite markers mapped to this region, including markers tightly linked to the BRCA-2, retinoblastoma (Rb), and DBM (deleted in B-cell malignancy) loci. Among the 80 clinically localized cases, 24 showed allelic loss at one or more 13q loci. In all cases with loss, the Rb and/or DBM loci were lost. No cases were found with loss of Rb without loss of DBM or loss of DBM without loss of Rb, implying a role for both the Rb and DBM loci in clinically localized prostate cancer. Loss of the BRCA-2 locus was less common (4 of 55 informative cases) and was always associated with loss of Rb and/or DBM loci. Thus, the BRCA-2 locus does not appear to play as important a role in clinically localized prostate cancer as the Rb and/or DBM loci. Allelic loss on 13q was extremely common in the clinically advanced cases; it was present in 14 of the 15 cases. The rate of allelic loss at each of the three tumor suppressor loci was increased significantly in the advanced cases (P < 0.01, Fisher's exact test). Thus, loss of heterozygosity on 13q is very common in prostate cancer and occurs at all three known or putative tumor suppressor loci on the centromeric portion of chromosome 13q.

The hematologic toxicity of interleukin-2 in patients with metastatic melanoma and renal cell carcinoma.

BACKGROUND: High dose interleukin-2 (IL-2) has been found to produce durable antitumor responses in some patients, benefiting most greatly those patients with melanoma and renal cell carcinoma. In this paper, the hematologic toxicity and changes resulting from high dose IL-2 alone administered by intravenous bolus are discussed. METHODS: One hundred ninety-nine consecutive patients treated with high dose IL-2 alone from January 1, 1988 to December 31, 1992 were included in this study. All patients had a diagnosis of metastatic melanoma or metastatic renal cell carcinoma and were treated at the National Cancer Institute (Bethesda, MD). RESULTS: Anemia, requiring erythrocyte transfusions, occurred in 14% of all treatment courses, with a median of two units of erythrocytes transfused. Severe leukopenia ( < 1,000 leukocytes/mm3) was rare (1.5% of all patients) and was not associated with any infectious complications. Severe thrombocytopenia ( < 30,000 platelets/mm3) occurred in 2.2% of all treatment cycles, with two patients experiencing a grade 3 hemorrhage, defined as gross blood loss, and one patient experiencing a grade 4 hemorrhage, defined as a debilitating blood loss. Defects in the coagulation pathway were common: abnormal partial thromboplastin time and prothrombin time values occurred in 64% and 25% of the treatment cycles, respectively. In addition, a mean clearance of 93% of lymphocytes from the peripheral blood was observed within 24 hours after initiating IL-2 therapy. This was followed by rebound lymphocytosis to a mean of 198% of baseline on posttreatment Day 4. There were no treatment-related deaths. CONCLUSIONS: During IL-2 therapy, adverse sequelae of anemia, thrombocytopenia, coagulopathy, and leukopenia were usually mild, transient and rarely limited therapy. A profound decrease in lymphocytes in the peripheral circulation occurred within 24 hours after initiating therapy, with a rebound occurring after stopping IL-2. No specific hematologic parameter was associated significantly with a patient's increased probability of responding to therapy.

Renal dysfunction associated with the administration of high-dose interleukin-2 in 199 consecutive patients with metastatic melanoma or renal carcinoma.

PURPOSE: To describe the incidence and management of renal dysfunction associated with the use of high-dose interleukin-2 (IL-2) (as is currently approved) in the treatment of cancer patients. PATIENTS AND METHODS: One hundred ninety-nine consecutive patients with metastatic renal carcinoma or melanoma were treated with intravenous bolus infusions of IL-2 alone (720,000 IU/kg) every 8 hours. RESULTS: Patients received 310 courses (589 cycles) of therapy and most experienced oliguria, hypotension, and weight gain; 13% of cycles were discontinued due to increased serum creatinine levels. Creatinine values (mean pretherapy, 1.2 mg/dL) increased during therapy and peaked (mean, 2.7 mg/dL) approximately 1 day after discontinuation of the second cycle of IL-2. Off therapy, toxicities reversed promptly and creatinine values returned to baseline. Higher peak creatinine values occurred in patients with renal carcinoma (v melanoma), older patients, males (v females), and those who had undergone prior nephrectomy. These same patient subsets received fewer doses of IL-2, but clinical responses were not associated with creatinine values or number of IL-2 doses administered. Urinalyses showed the appearance of protein, bilirubin, RBCs, WBCs, and granular casts during therapy, which cleared completely on follow-up evaluation. CONCLUSION: High-dose IL-2 can be safely administered to cancer patients. The associated renal dysfunction is transient and without evidence of intrinsic long-term renal damage. Practical guidelines for patient management have been identified.

Ram sexual pheromone: first approach of chemical identification.

A series of experiments has been designed with the aim of identifying the pheromone of the ram responsible for the primer effect--induction of a LH peak and ovulation--in anoestrous ewes. In a first experiment, the pheromonal activity of various sources was tested, extract of ram fleece and ante orbital gland secretion induced characteristic changes in LH secretion, whereas urine was ineffective. A second experimental series showed that an accurate separation of the ram's fleece extract in acid and neutral fractions resulted in each case in a complete loss of activity whereas both together were efficient, indicating that the pheromonal action involves several components. From GC-MS analysis of both fractions, and after comparison of male and female wool extract, semi-synthetic formulations were tested. The association of synthetic 1,2-hexadecanediol and 1,2-octadecanediol with the natural acid fraction was efficient in stimulating LH release in anoestrous ewes. As the most frequent linear fatty acids have been shown not to be necessary, a role of branched and oxygenated fatty acids has been hypothesised.