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Query: UMLS:C0027819 (
neuroblastoma
)
27,800
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Catecholamines are biogenic amines that play an important role in the nervous system. Some catecholamines have been used as tumor makers of phenochromocytoma, paraganglioma and
neuroblastoma
. The analysis of total catecholamine metabolites should be useful for one-shot screening of multiple aspects of diseases; however, it is difficult to do this, because the catecholamine metabolites are divided into three groups: five amines, one amino acid and three carbonic acids. Catecholamines and small molecules were separated from plasma proteins by an internal-surface reversed-phase column (protein-coated octadeyclsilica column) and were analyzed by liquid chromatography (LC)/mass spectrometry (MS) using electrospray ionization time-of-flight MS. Using a reversed-phase column and hydrophilic mobile phases, we succeeded in the separation of nine catecholamines, all of which had similar structures. These nine substances were eluted in the following order: norepinephrine, epinephrine, normetanephrine, dopamine, metanephrine,
3,4-dihydroxyphenylalanine
, vanillomandelic acid, 3,4-dihydroxyphenylacetic acid and homovanillic acid. The reproducibility of this method was acceptable. The highest coefficient of variation was 7.4%. In addition, various types of compounds were separated from and detected in plasma proteins by applying LC/MS. The plasma direct injection method, which uses an internal-surface reversed-phase column and an ion-pair reagent, allowed us to separate small molecules from plasma proteins. MS detected some compounds that high-performance LC could not succeed in separating and detecting with UV detection. We think that the method can be applied to find new markers in
neuroblastoma
, by comparing the plasma of patients with that of normal infants. The method can be also used to help in making a diagnosis of other diseases and finding their new makers.
...
PMID:Pretreatment and one-shot separating analysis of whole catecholamine metabolites in plasma by using LC/MS. 1679 60
(+/-)-3,4-Methylenedioxymethamphetamine (MDMA, also known as "ecstasy") is a chiral drug that is essentially metabolized in humans through O-demethylenation into 3,4-dihydroxymethamphetamine (HHMA). There has recently been a resurgence of interest in the possibility that MDMA metabolites, especially 5-(N-acetylcystein-S-yl)-N-methyl-alpha-methyldopamine (designated as 5-NAC-HHMA), might play a role in MDMA neurotoxicity. However, the chirality of MDMA was not considered in previously reported in vivo studies because HHMA, the precursor of the 5-NAC-HHMA metabolite, was used as the racemate. Since the stereochemistry of this chiral drug needs to be considered, the first total synthesis of R-(-)-HHMA is reported. Using
L-DOPA
as the chiral source, the preparation of R-(-)-HHMA is achieved through seven steps, in 30% overall yield and 99.5% enantiomeric excess. The cytotoxicity of R-(-)-HHMA and related catecholamines has been further determined by flow cytometric analysis of propidium iodide uptake in human dopaminergic
neuroblastoma
SH-SY5Y cells and by an Escherichia coli plate assay, specific for the detection of oxidative toxicity. The good correlation between the toxicities observed in both systems suggests that SH-SY5Y cells are sensitive to oxidative toxicity and that cell death (necrosis) would be mediated by reactive oxygen species mainly generated from redox active quinonoid centers. In contrast, apoptosis was detected for 3,4-dimethoxymethamphetamine (MMMA), the synthetic precursor of HHMA possessing a protected catechol group. MMMA was not toxic in the bacterial assay, indicating that its toxicity is not related to increased oxidative stress. Finally, we can conclude that there is a need to distinguish the toxicity ascribed to MDMA itself, also bearing a protected catechol moiety, from that depending on MDMA biotransformation leading to catechol metabolites such as HHMA and the thioether conjugates.
...
PMID:Synthesis and in vitro cytotoxicity profile of the R-enantiomer of 3,4-dihydroxymethamphetamine (R-(-)-HHMA): comparison with related catecholamines. 2001 34
We evaluated the feasibility and usefulness of reverse transcriptase-polymerase chain reaction (RT-PCR) on fine-needle aspirates for categorization of small blue round cell tumors (SBRCTs). A total of 51 cases, including 25 Ewing sarcoma/peripheral primitive neuroectodermal tumors (PNETs), 11 rhabdomyosarcomas, 13 neuroblastomas, and 2 desmoplastic small round cell tumors (DSRCTs) were analyzed. The detection of the EWS-FLI1 (20/25) and EWS-ERG (4/25) fusion transcripts resolved 24 of 25 cases of Ewing sarcoma/PNET. The PAX3/7-FKHR fusion transcript was detected in 2 of 4 cases of alveolar rhabdomyosarcoma and the EWS-WT1 transcript in both cases of DSRCT. Tyrosine hydroxylase and
3,4-dihydroxyphenylalanine
(dopa) decarboxylase transcripts were demonstrated in 10 of 13 cases of
neuroblastoma
. In comparison, immunocytochemical analysis resolved 19 (76%) of 25 Ewing sarcomas, 9 (82%) of 11 rhabdomyosarcomas, 6 (46%) of 13 neuroblastomas, and 1 (50%) of 2 DSRCTs. Overall, RT-PCR resolved 38 (86%) of 44 vs 35 (69%) of 51 cases by immunocytochemical analysis. RT-PCR is easily applied to fine-needle aspirates of SBRCT and greatly facilitates accurate tumor typing.
...
PMID:Reverse transcriptase-polymerase chain reaction as an ancillary molecular technique in the diagnosis of small blue round cell tumors by fine-needle aspiration cytology. 2023 17
The main lesion in Parkinson disease (PD) is loss of substantia nigra dopaminergic neurons.
Levodopa
(
L-DOPA
) is the most widely used therapy, but it does not arrest disease progression. Some possible contributing factors to the continuing neuronal loss are oxidative stress, including oxidation of
L-DOPA
, and neurotoxins generated by locally activated microglia and astrocytes. A possible method of reducing these factors is to produce
L-DOPA
hybrid compounds that have antioxidant and antiinflammatory properties. Here we demonstrate the properties of four such
L-DOPA
hybrids based on coupling
L-DOPA
to four different hydrogen sulfide-donating compounds. The donors themselves were shown to be capable of conversion by isolated mitochondria to H(2)S or equivalent SH(-) ions. This capability was confirmed by in vivo results, showing a large increase in intracerebral dopamine and glutathione after iv administration in rats. When human microglia, astrocytes, and SH-SY5Y
neuroblastoma
cells were treated with these donating agents, they all accumulated H(2)S intracellularly as did their derivatives coupled to
L-DOPA
. The donating agents and the
L-DOPA
hybrids reduced the release of tumor necrosis factor-alpha, interleukin-6, and nitric oxide from stimulated microglia, astrocytes as well as the THP-1 and U373 cell lines. They also demonstrated a neuroprotective effect by reducing the toxicity of supernatants from these stimulated cells to SH-SY5Y cells.
L-DOPA
itself was without effect in any of these assays. The H(2)S-releasing
L-DOPA
hybrid molecules also inhibited MAO B activity. They may be useful for the treatment of PD because of their significant antiinflammatory, antioxidant, and neuroprotective properties.
...
PMID:Effects of hydrogen sulfide-releasing L-DOPA derivatives on glial activation: potential for treating Parkinson disease. 2052
Fluoro-2-deoxy-D-glucose-positron emission tomography (FDG-PET) is utilized in more than 90% of cancers in staging, re-staging, assessing therapy response and during the follow-up. However, not all tumors show significant increase of metabolic activity on FDG-PET imaging. This is particularly true for prostate cancer, neuroendocrine tumors and hepatic tumors. In this review we have considered those already used for clinical applications such as 11C- and 18F-Choline, 11C-Methionine and 18F-FET, 18F-
DOPA
, 68Ga-DOTA-somatostatine analogues, 11C-Acetate and 18F-FLT. Choline presents a high affinity for malignant prostate tissue, even if low grade. Choline can be labeled with either 11C or 18F, the former being the preference due to lower urinary excretion and patients exposure. The latter is more useful for possible distribution to centers lacking in on-site cyclotron. Methionine is needed for protein synthesis and tumor cells require an external supply of methionine. These tracers have primarily been used for imaging of CNS neoplasms. The most appropriate indication is when conventional imaging procedures do not distinguish between edema, fibrosis or necrosis and disease relapse. In addition, the uptake of 11C-Methionine is proportional to the tumor grade and, therefore, the maximum small unilamellar vesicles (SUV) inside the brain mass before therapy is somehow considered a prognostic value. Neuroendocrine tumors (carcinoids, pheocromocytoma,
neuroblastoma
, medullary thyroid cancer, microcytoma, carotid glomus tumors, and melanoma) demonstrate an increased activity of L-DOPA decarboxylase, and hence they show a high uptake of 18FDOPA. For the study of NETs, 68Ga-DOTA-TOC/DOTA-NOC has been introduced as PET tracer. This compound for PET imaging has a high affinity for sst2 and sst5 and has been used in the detection of NETs in preliminary studies; 68Ga-DOTA-NOC PET is useful before metabolic radiotherapy in order to evaluate the biodistribution of the therapeutic compound; 18F-FLT is a specific marker of cell proliferation and the most important field of application of FLT is lung cancer. Other tracers are used in PET utilized as markers of hypoxia inside big neoplastic masses include 18F-MISO, 64Cu-ATSM, 18F-EF5, which highlight the presence of hypoxic areas are useful for patients that must be treated with radiotherapy.
...
PMID:Non-FDG PET in the practice of oncology. 2044 72
Positron emission tomography/computed tomography (PET/CT) has become an important imaging modality in the non-invasive evaluation and monitoring of children with known or suspected malignant diseases. In sarcoma patients, [18F]FDG (FDG) PET and FDG PET/CT is useful in staging, therapy monitoring, and detection of relapse. However, FDG PET has been proven to be less sensitive than chest CT in the detection of pulmonary metastases derived from sarcoma. This disadvantage has been overcome using a PET/CT scanner. In
neuroblastoma
patients, PET using FDG is indicated in MIBG-negative cases. Furthermore, there are specific PET tracers for tumors of the sympathetic nervous system, such as [11C]Hydroxyephedrine (HED) and [18F]-labeled dihydrophenylalanine (F-
DOPA
), which can be used for PET/CT imaging for detection of disease, staging and monitoring therapy. However, there are only few studies using specific PET tracers in
neuroblastoma
patients. In other pediatric malignancies including germ cell tumors and hepatoblastoma PET and PET/CT may be helpful in individual cases, but the literature in these entities is limited so far. Although publications on the additional value of the combined PET/CT compared to both stand-alone modalities are still limited in pediatrics, it can already be anticipated that the combination of morphological and functional information obtained by integrated PET/CT will improve the accuracy of staging and will change patient management in a significant number of pediatric patients.
...
PMID:FDG-PET/CT in pediatric solid tumors. 2082 8
Levodopa
(
L-DOPA
), a close structural analogue of the protein amino acid L-tyrosine, can substitute for L-tyrosine in protein synthesis and be mistakenly incorporated into newly synthesised proteins in vitro. We show that
L-DOPA
-containing proteins are present in the brain in
L-DOPA
-treated Parkinson's disease patients and accumulate in specific brain regions. In vitro studies demonstrate that substitution of L-tyrosine residues in proteins with
L-DOPA
causes protein misfolding and promotes protein aggregation in SH-SY5Y
neuroblastoma
cells resulting in the appearance of autofluorescent bodies. We show that the presence of
L-DOPA
-containing proteins causes profound changes in mitochondria and stimulates the formation of autophagic vacuoles in cells. Unlike
L-DOPA
, which is toxic to cells through its ability to generate radicals, proteins containing incorporated
L-DOPA
are toxic to SH-SY5Y cells by a mechanism independent of oxidative stress and resistant to antioxidants. These data suggest that the accumulation of
L-DOPA
-containing proteins in vulnerable cells might negatively impact on cell function.
...
PMID:L-DOPA is incorporated into brain proteins of patients treated for Parkinson's disease, inducing toxicity in human neuroblastoma cells in vitro. 2200 74
Parkinson's disease (PD) is one of the most common neurodegenerative disorders characterized by decreased levels of the neurotransmitter dopamine (DA) in the striatum of the brain, as a result of degeneration of DA neurons.
Levodopa
(
L-Dopa
) crosses the blood-brain barrier and its administration replenishes the loss of DA in dopaminergic neurons in PD patients. Despite the evident beneficial effects,
L-Dopa
use may cause side effects and its toxicity found in in vitro assays has been attributed to the generation of reactive oxygen species (ROS):
L-Dopa
is converted to DA and its metabolism and autoxidation gives rise to quinones, semiquinones, and hydrogen peroxide. Despite this evidence,
L-Dopa
in some in vivo and in vitro experiments showed no toxic effects, or even antioxidant effects. Two major peripheral
L-Dopa
metabolic pathways, driven by the enzymes Aromatic L-amino acid decarboxylase (AADC) and catechol-O-methyl transferase (COMT), significantly deplete the amount of
L-Dopa
reaching the brain. The low bioavailability of
L-Dopa
may cause a wide variation in clinical response between patients. Strategies addressing to improve the bioavailability of
L-Dopa
include coadministering
L-Dopa
with carbidopa, a decarboxylase inhibitor, as multiple daily doses. We utilized catecholaminergic human
neuroblastoma
cells to study DNA damage and ROS production after
L-Dopa
and carbidopa treatments. Our data lead us to confirm that
L-Dopa
may have a protective effect on dopaminergic cells especially at certain concentrations, in particular, toward the production of ROS and their toxic effects on DNA. Furthermore in the combined treatment, with induction of ROS following administration of H(2)O(2), carbidopa is effective in reducing the damage caused by reactive oxygen intermediates both alone and in combination with
L-Dopa
.
...
PMID:Protective effects of L-dopa and carbidopa combined treatments on human catecholaminergic cells. 2302 Jan 19
We report the case of a 6-year-old child with stage 4
neuroblastoma
, previously treated with chemotherapy, which relapsed in the right mandibular branch, right submandibular lymph nodes, and bone marrow. These sites of recurrence were detected on diagnostic (123)I-MIBG and confirmed by (18)F-
DOPA
-PET/CT, which revealed the following 2 additional sites of disease: in the skull base and the left supraclavicular lymph nodes. The patient was scheduled for radioiodine therapy and received a total dose of 7400 MBq (200 mCi) of (131)I-MIBG. The whole-body scan, acquired 72 hours later, revealed all sites of disease detected by (18)F-
DOPA
-PET/CT, including those negative on (123)I-MIBG scan.
...
PMID:Bone and lymph node metastases from neuroblastoma detected by 18F-DOPA-PET/CT and confirmed by posttherapy 131I-MIBG but negative on diagnostic 123I-MIBG scan. 2489 28
In the past decades, the clinical use of dopamine agonists has expanded from adjunct therapy in patients with a deteriorating response to
L-3,4-dihydroxyphenylalanine
(
L-DOPA
) to monotherapy for the treatment of early PD. Dopamine agonists provide their antiparkinsonian benefit through stimulation of brain postsynaptic type 2 dopamine receptors that exert their effect through classical cAMP-dependent mechanisms, as well as cAMP-independent cellular signaling cascades, including the Akt/glycogen synthase kinase 3 (GSK3) pathway. Alterations of Akt/GSK3 have been observed and may contribute to the neurodegenerative processes and the development of
L-DOPA
-induced dyskinesia. The effects
L-DOPA
and quinpirole, a dopamine agonist, on the two key regulatory kinases, Akt and GSK3, were evaluated in
neuroblastoma
cell line.
L-DOPA
and dopamine agonist dose-dependently and differentially modulated Akt and GSK3 expression and phosphorylation when added alone or combined. The combined treatment inverted or potentiated the modulatory properties of the single compound. The drug- and concentration-dependent balance of dopamine receptor stimulation over auto-oxidation may distinctively modulate GSK3 isoforms and Akt. Our results indicate that particular attention must be given to drug concentration and combination when multiple therapies are applied for the clinical treatment of PD patients.
...
PMID:Single or combined treatment with L-DOPA and quinpirole differentially modulate expression and phosphorylation of key regulatory kinases in neuroblastoma cells. 2389 26
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