Mass screening for neuroblastoma in infants.

Neuroblastoma (NB) is the only pediatric tumor that is screened for nationwide by detecting the urinary levels of homovanillic acid and/or vanillylmandelic acid; however, whether NB screening reduces the mortality rate has not been established. This review compared the incidence and mortality rates among data from international mass screening for NB, as well as an analysis of differences in age of screening, detection methods, and diagnostic biomarkers. A well-designed trial exploring possible benefits and hazards is warranted prior to resuming mass screening for NB.

Is Preoperative Biochemical Testing for Pheochromocytoma Necessary for All Adrenal Incidentalomas?

This study examined whether imaging phenotypes obtained from computed tomography (CT) can replace biochemical tests to exclude pheochromocytoma among adrenal incidentalomas (AIs) in the preoperative setting.We retrospectively reviewed the medical records of all patients (n = 251) who were admitted for operations and underwent adrenal-protocol CT for an incidentally discovered adrenal mass from January 2011 to December 2012. Various imaging phenotypes were assessed for their screening power for pheochromocytoma. Final diagnosis was confirmed by biopsy, biochemical tests, and follow-up CT.Pheochromocytomas showed similar imaging phenotypes as malignancies, but were significantly different from adenomas. Unenhanced attenuation values ≤10 Hounsfield units (HU) showed the highest specificity (97%) for excluding pheochromocytoma as a single phenotype. A combination of size ≤3 cm, unenhanced attenuation values ≤ 10 HU, and absence of suspicious morphology showed 100% specificity for excluding pheochromocytoma.Routine noncontrast CT can be used as a screening tool for pheochromocytoma by combining 3 imaging phenotypes: size ≤3 cm, unenhanced attenuation values ≤10 HU, and absence of suspicious morphology, and may substitute for biochemical testing in the preoperative setting.

Retrospective study of neuroblastoma in Chinese neonates from 1994 to 2011: an evaluation of diagnosis, treatments, and prognosis : a 10-year restrospective study of neonatal neuroblastoma.

PURPOSE: The purpose of the study is to review the clinical features, treatments, and outcomes of neonatal neuroblastoma (NB). METHODS: A retrospective analysis was performed on 42 patients with NB between January 1994 and December 2011. RESULTS: MYCN amplification was detected in nine tumor samples. The ratio of unfavorable histology to favorable histology was 1:2 in NB patients. The 5-year overall survival (OS) of NB patients was 85.7 %. The 5-year OS in patients in the operation group was 83.3 %, chemotherapy group was 83.3 %, and the "wait-and-see" group was 100 % (P = 0.04). Overall, the prognosis was favorable, except in patients with elevated MYCN amplification or vanillylmandelic acid. CONCLUSIONS: NB patients were more sensitive and vulnerable to chemotherapy and operation. The "wait-and-see" strategy should be highlighted in the treatment of NB.

Sensitive, rapid and easy analysis of three catecholamine metabolites in human urine and serum by liquid chromatography tandem mass spectrometry.

A sensitive and easy analytical method for catecholamine metabolites including 4-hydroxy-3-methoxyphenylglycol sulfate (HMPG sulfate), vanillylmandelic acid (VMA) and homovanillic acid (HVA) determination was developed based on liquid chromatography-tandem mass spectrometry in a negative multiple reaction monitoring mode. The analytes were rapidly separated on a reversed-phase Waters Xbridge C18 column (150 × 2.1 mm i.d.) with the mobile phase of 15% (v/v) acetonitrile containing 2 mM ammonium formate and 85% (v/v) formic acid solution (0.05%, v/v). Mass spectrometric conditions, such as characteristic fragmentations and quantification ion transitions, both with chromatographic conditions including separation column type and mobile phase composition, were systematically investigated to get optimal sensitivity and specificity. The limits of detection were in the range of 0.03-0.7 ng/mL for the targets. Recovery rates of spiked urine samples with three different concentration levels (low, middle and high) were above 86% with precisions less than 5.7%. For serum analysis, acetonitrile chosen both as protein precipitation reagent and extraction solvent facilitates to reduce matrix effects. Recovery rates of spiked serum sample were in the range of 90.6% to 111.1% for three targets. The intra-day and inter-day precisions were satisfactory less than 8.7%. This proposed method was successfully applied to determine HMPG sulfate, HVA and VMA present in human urine and serum.

Self-quenching in the electrochemiluminescence of tris(2,2'-bipyridyl) ruthenium(ii) using metabolites of catecholamines as co-reactants.

Electrochemiluminescence (ECL) of Ru(bpy)(3)(2+) using metabolites of catecholamines: homovanillic acid (HVA) and vanillylmandelic acid (VMA) as co-reactants were investigated in aqueous solution for the first time. When HVA and VMA were co-existent in the buffer solution containing Ru(bpy)(3)(2+), ECL peaks were observed at a potential corresponding to the oxidation of Ru(bpy)(3)(2+), and the ECL intensity was increased noticeably when the concentrations of HVA and VMA were at lower levels. The linear calibration range was from 8.0 × 10(-5) to 1.0 × 10(-9) M for HVA and VMA. The detection limit (S/N = 3) of HVA and VMA was 4.0 × 10(-10) M. The formation of the excited state Ru(bpy)(3)(2+*) was confirmed to result from the reaction between Ru(bpy)(3)(3+) and the intermediates of HVA or VMA radicals. Moreover, it was found that the ECL intensity was quenched significantly when the concentrations of HVA and VMA were relatively higher. The mechanism of self-quenching processes involved in the Ru(bpy)(3)(2+)-HVA and -VMA ECL systems are proposed in this study.

[Biological diagnosis of pheochromocytomas and paragangliomas]. / Diagnostic biologique des phéochromocytomes et paragangliomes.

Pheochromocytomas and/or paragangliomas are rare, heterogeneous tumors of the chromaffin cells. Thirty percent of the patients presented with these diseases in a hereditary context. The biological diagnosis relies on the identification of excessive secretion of the metanephrines which are more sensitive and specific than those of catecholamines The published recommendations give the opportunity to choose between the free metanephrines and the fractionated metanephrines in sera or urines. The concentrations of the free plasmatic metanephrines reflect the ongoing production of tumor. They are little sensitive to the renal failure. The assay of the vanillylmandelic acid should be dropped because of its inefficiency. The assay of the chromogranin A in serum should be used in association with those of metanephrines in the diagnosis but also in the follow-up. Its role still has to be precised.

The effect of stress hormones on cerebral hemodynamics in patients with chronic posttraumatic stress disorder.

The aim of the study was to assess the possible correlation between catecholamine and cortisol levels and changes in cerebral hemodynamics in patients with chronic posttraumatic stress disorder (PTSD). The study included 50 patients with chronic PTSD first ever hospitalized for psychiatric treatment and 50 healthy control subjects. All study subjects were aged 30-50. In PTSD patients, 24-h urine levels of the epinephrine and norepinephrine metabolites vanillylmandelic acid (VMA) and cortisol were determined and transcranial Doppler ultrasonography was performed on day 1 of hospital stay and repeated after 21-day psychiatric medicamentous treatment. On initial testing, increased level of 24-h VMA, decreased cortisol level and elevated mean blood flow velocity (MBFV) in the circle of Willis vessels were recorded in 25 (50.00%) patients. Repeat findings obtained after 21-day psychopharmaceutical therapy showed increased 24-h VMA, decreased cortisol and elevated MBFV in the circle of Willis vessels in seven (14.00%) patients (initial vs. repeat testing, P = 0.0002). Such parameters were not recorded in any of the control subjects (initial PTSD patient testing vs. control group, P = 0.0000). Study results pointed to a significant correlation between increased catecholamine levels, decreased cortisol level and elevated MBFV in the circle of Willis vessels caused by cerebral vasospasm. Psychiatric medicamentous therapy administered for three weeks significantly reduced the proportion of patients with concurrently altered cerebral hemodynamics, increased levels of catecholamine metabolites and decreased level of cortisol.

Expression of human organic anion transporters in the choroid plexus and their interactions with neurotransmitter metabolites.

The purpose of the present study was to elucidate the expression of human organic anion transporter 1 (hOAT1) and hOAT3 in the choroid plexus of the human brain and their interactions with neurotransmitter metabolites using stable cell lines. Immunohistochemical analysis revealed that hOAT1 and hOAT3 are expressed in the cytoplasmic membrane and cytoplasm of human choroid plexus. Neurotransmitter metabolites, namely, 5-methoxyindole-3-acetic acid (5-MI-3-AA), homovanillic acid (HVA), vanilmandelic acid (VMA), 3,4-dihydroxyphenylacetic acid (DOPAC), 5-hydroxyindole-3-acetic acid (5-HI-3-AA), N-acetyl-5-hydroxytryptamine (NA-5-HTT), melatonin, 5-methoxytryptamine (5-MTT), 3,4-dihidroxymandelic acid (DHMA), 5-hydroxytryptophol, and 5-methoxytryptophol (5-MTP), but not methanephrine (MN), normethanephrine (NMN), and 3-methyltyramine (3-MT), at 2 mM, inhibited para-aminohippuric acid uptake mediated by hOAT1. On the other hand, melatonin, 5-MI-3-AA, NA-5-HTT, 5-MTT, 5-MTP, HVA, 5-HI-3-AA, VMA, DOPAC, 5-hydroxytryptophol, and MN, but not 3-MT, DHMA, and NMN, at 2 mM, inhibited estrone sulfate uptake mediated by hOAT3. Differences in the IC(50) values between hOAT1 and hOAT3 were observed for DHMA, DOPAC, HVA, 5-HI-3-AA, melatonin, 5-MI-3-AA, 5-MTP, 5-MTT, and VMA. HOAT1 and hOAT3 mediated the transport of VMA but not HVA and melatonin. These results suggest that hOAT1 and hOAT3 are involved in the efflux of various neurotransmitter metabolites from the cerebrospinal fluid to the blood across the choroid plexus.

The use of enzyme immunoassays for the detection of abzymatic activities. Application to an enantioselective thioacetal hydrolysis activity.

Relying on the particularly high specificity displayed by antibodies, enzyme immunoassays have proved to be one of the most efficient tools for early detection of the catalytic activities displayed by antibodies. We took advantage of such an assay, namely the Cat-enzyme-linked immunoassay (EIA) approach developed in our laboratories, both to exhibit and characterise an antibody-catalysed thioacetal hydrolysis. Monoclonal antibody (mAb) H3-32 was thus identified to accelerate the hydrolysis reaction of thioacetal substrate (NC9) to vanillylmandelic acid (VMA), with a k(cat) of 0.148 h(-1) (k(uncat) = 6.85 x 10(-5) h(-1)), and a K(M) of 720 microM. Taking advantage of the enantiomeric discrimination between (R)- and (S)-VMA displayed by some of the anti-H3 monoclonal antibodies, we were also able to determine that (S)-VMA was preferentially formed during this abzymatic hydrolysis with a 47% enantiomeric excess. All these EIA measurements were confirmed through HPLC analyses.

Adrenergic hyperactivity and metanephrine excess in the nucleus accumbens after prefrontocortical dopamine depletion.

Selective dopamine depletion within the medial prefrontal cortex in rats is known to enhance dopamine and norepinephrine levels in the nucleus accumbens and to induce characteristic behavioral disturbances. The present study was designed to determine levels of adrenaline, apart from dopamine and norepinephrine, and metabolites in the nucleus accumbens after prefrontocortical dopamine depletion. Prefrontocortical dopamine depletion was carried out by injecting 6-hydroxydopamine, and it was validated through: the emergence of behavioral disturbances such as amphetamine-induced stereotypies, spontaneous motor hyperactivity, and enhanced "anxiety-like" responses and through postmortem quantification of catecholamine levels by using high-performance liquid chromatography. The findings indicated that lesioned rats exhibited more oral stereotypies after amphetamine, were hyperlocomotive, and showed more pronounced anxiety-like behaviors than controls. Following prefrontocortical dopamine depletion, postmortem concentrations of dopamine and norepinephrine, along with the metabolites 3,4-dihydroxyphenylacetic acid and vanillylmandelic acid, were reliably enhanced in the nucleus accumbens as expected, and dopamine turnover was decreased. Furthermore the nucleus accumbens contained higher levels of adrenaline and its transmethylated metabolite metanephrine. To sum up, prefrontocortical dopamine depletion induces motor and emotional disturbances in rats and alters the neurochemical profile of the nucleus accumbens, not only inducing dopaminergic and noradrenergic hyperactivity but also leading to adrenaline and metanephrine excess.

Induction of catecholamine synthesis in human neuroblastoma cells by replication inhibitors and sodium butyrate.

Various inhibitors of DNA synthesis induced neurite extension in human neuroblastoma cells. In order to clarify morphology-function relationship in differentiation of neuroblastoma cells, the effect of the replication inhibitors on inducibility of catecholamine synthesis was examined. The reagents alone did not affect production of dopamine and noradrenaline, but joint administration of each inhibitor and sodium butyrate considerably promoted the catecholamine synthesis, without additional change in neurite profile. Although inactive in neurite extension, sodium butyrate was moderately active in catecholamine production. The promoting effect of thymidine (or hydroxyurea) and sodium butyrate was repealed by alpha-amanitin, actinomycin D or cycloheximide.

[Effects of aluminum on neurobehavioral function and metabolism of monoamine neurotransmitter].

OBJECTIVE: To evaluate the effects of occupational exposure to aluminum on neurobahavioral function and metabolism of monoamine neurotransmitter. METHODS: Thirty-three workers exposed to aluminum and 40 controls were studied. Air aluminum concentrations in workplace environment were detected with an atomic absorption spectrophotometer, homovanillic acid (HVA) and vanilylmandellic acid (VMA) in urine and aluminum in serum and urine were detected with high perfolmance liquid chromatography. Neurobehavioral function was tested with Neurobehavioral Core Test Battery recommended by WHO. RESULTS: Geometric time-weighted average of aluminum in workplace environment was 0.95 mg/m3, ranging from 0.31 to 4.12 mg/m3, and urine aluminum levels in workers exposed to aluminum averaged 12.25 micrograms/L, significantly higher than that in controls (5.78 micrograms/L). There was no significant difference in serum aluminum between the exposed and controls. Both urine VMA and HVA levels were higher in the workers exposed to aluminum, and urine VMA level in the exposed was significantly higher than that in controls. There was significant difference in neurobehavioral test, including Santa Ana, digit symbol and Benton tests between the exposed and control workers. CONCLUSION: It suggests that occupational exposure to low level of aluminum can affect the neurobehavioral function and metabolism of monoamine neurotransmitter.

Metabolic characterisation of a novel vanillylmandelate-degrading bacterium.

A newly isolated gram-negative bacterium, possibly Brevundimonas diminuta, utilised D,L-vanillylmandelate (D,L-VMA) as a sole carbon and energy source. The organism converted D,L-VMA to vanillylglyoxylate using a soluble NAD-dependent dehydrogenase specific for D-VMA and a dye-linked, membrane-associated L-VMA dehydrogenase. Vanillylglyoxylate was further metabolised by decarboxylation, dehydrogenation and demethylation to protocatechuate. A 4,5-dioxygenase cleaved protocatechuate to 2-hydroxy-4-carboxymuconic semialdehyde. Partially purified d-VMA dehydrogenase exhibited optimal activity at 30 degrees C and pH 9.5 and had an apparent Km for D-VMA of 470 microM. Although induced by several substituted mandelates, the enzyme had a narrow substrate specificity range with virtually no activity towards D-mandelate. Such properties render the enzyme of potential use in both diagnostic and biosynthetic applications.

Tyrosine uptake and regional brain monoamine metabolites in a rat model resembling congenital hyperammonemia.

Hyperammonemia found in congenital disorders has a toxic effect on the central nervous system. Disturbances of brain neurotransmitter metabolism have been proposed, such as an increased transport of tryptophan into the brain and an increased flux through the serotonin pathway. Results concerning the catecholamine pathway are, however, contradictory. We therefore studied whether hyperammonermia increases brain uptake of the neurotransmitter precursor amino acid tyrosine and whether these changes affect the concentration of neurotransmitters and their metabolites in different brain areas (frontal cortex, caudatus-putamen, thalamus, hypothalamus, hippocampus/substantia nigra, brainstem) of rats made hyperammonemic with urease. The brain uptake of tyrosine was measured in the forebrain, brainstem, and cerebellum. The brain areas were analyzed for dopamine, 3,4-hydroxyphenylacetic acid; homovanillic acid, norepinephrine, and vanillylmandelic acid. The brain uptake index of tyrosine was increased in the forebrain and brainstem of the hyperammonemic rats with concomitantly elevated concentrations in the forebrain of tyrosine, phenylalanine, and tryptophan. The homovanillic acid content was significantly increased in the hypothalamus, hippocampus/substantia nigra and brainstem. The concentrations of norepinephrine, dopamine, and 3, 4-hydroxyphenylacetic acid were not significantly changed. Vanillylmandellic acid was decreased in the caudatus-putamen, thalamus, and hypothalamus. The data indicate an undisturbed neurotransmitter synthesis and, taken with the augmented tyrosine uptake at the blood-brain barrier, an increased flux through the dopamine pathway. These changes observed in the hyperammonemic animal model could contribute to the understanding of the pathogenic mechanisms and offer an explanation for the neuropsychiatric disturbances observed in children with congenital hyperammonemia.

Urinary homovanillic acid and vanillylmandelic acid in workers exposed to carbon disulfide.

Homovanillic acid (HVA) and vanillylmandelic acid (VMA), two end products of dopamine metabolism, were measured in 60 workers exposed to carbon disulfide (CS(2)) in a rayon factory and in 48 unexposed workers. The airborne CS(2) concentrations in eight major exposure zones of the plant were measured monthly over a period of 4 years, from 1990 to 1994. In addition, the exposure concentrations and exposure history of each worker were integrated to estimate the overall lifetime exposure. Industrial hygiene data showed that the geometric mean concentrations of CS(2) in the plant ranged from 2.68 to 20.19 ppm, and more than 15% of the studied population had been repeatedly exposed to CS(2) at concentrations exceeding the ACGIH recommended time-weighted average of 10 ppm. The results showed that there was a significantly lower level and a higher proportion of CS(2) workers with decreased HVA and VMA excretion. However, there were no statistical correlations between the two dopaminergic metabolites and the mean CS(2) concentration, and years of employment. In contrast, significant dose-effect relationships were observed between these two metabolites and the integrated cumulative exposure (ICE) variable. The correlation coefficients for ICE and HVA, and ICE and VMA were -0.35 (p < 0.01) and -0.20 (p <0.05), respectively. These data suggest that chronic exposure to CS(2) was associated with measurable reduction in catecholamine metabolite concentrations. This finding is compatible with the earlier observations in laboratory animals that CS(2) exposures interfere with neurochemical metabolism.

Noradrenergic and adrenergic functioning in autism.

A neurochemical assessment of noradrenergic and adrenergic functioning was carried out with autistic patients and normal control individuals. Norepinephrine and related compounds were measured in autistic (n = 17 unmedicated, 23 medicated; age range 9-29 years old) and normal controls (n = 27; age range 9-36 years old). Plasma levels and urinary excretion of 3-methoxy-4-hydroxy-phenylglycol (MHPG) were measured, as were urinary excretion rates of norepinephrine (NE), epinephrine (EPI), and vanillylmandelic acid (VMA). No significant group mean differences were seen between the autistic and control groups. In both the autistic and control groups urinary excretion rates of norepinephrine and epinephrine were substantially higher in the afternoon-evening (5-11 PM) compared to the overnight (11 PM-7 AM) collection period. Based on our neurochemical assessment, marked abnormalities in basal noradrenergic functioning do not appear to be present in autism.

[The neurohumoral status in depression]. / Neurohumoralni status depresija.

In 66 patients with endogenous depression (34 males and 32 females) the concentrations of biogene amine metabolites (vanilmandelic acid (VMA), 5-hydroxyindole acetic acid (5-HIIA), adrenaline and noradrenaline) were examined in 24-hrs urine and hormone in the serum: iodothyronine (T-3), thyroxine (T-4), thyroglobulin (Tg), thyroid-stimulating hormone (TSH), adrenocorticotropic hormone (ACTH), cortisol, prolactin and growth hormones. The examination was performed prior to the initiation of antidepressant therapy and 30 days after its application. The biogene amine metabolites were in reference values before initiation of the therapy, although values of 5-HIIA in women and were closer to the lower limit. Thirty days after the initiation of the antidepressant therapy the statistically significant difference was found at the level of p < 0.05 for adrenalin in men and for VMA and 5-HIIA in women. The hormone values before initiation of the therapy showed increased values of growth hormone, cortisol in men and of thyroglobulin, growth hormone and cortisol in women. At the end of the antidepressant therapy the statistically significant difference was found at the level of p < 0.05 for thyroglobulin and TSH in men and for thyroglobulin, growth hormone and cortisol in women. By comparing the results obtained before and after the antidepressant therapy, the statistically significant difference was found at the level of p < 0.05 for Tg in men and for Tg, T-3, prolactin and growth hormone compared to the women. It has been concluded that in patients with endogenous depression the important role in pathogenesis of the disease have some neurobiogenic disorders.