Fate of Radiometabolites
Lelio G. Colombetti in Principles of Radiopharmacology, 1979
Carbon 11 derivatives, dopamine, and norepinephrine are subject to a well-established metabolism. Dopamine is transformed into norepinephrine, and the latter is submitted part to the action of a catechol O methyl transferase giving normetanephrine, and part to a process of deamination that gives formation to an alcohol, dihydroxyphenylglycol, and to an acid, dihydroxymandelic acid. If normetanephrine is deaminated, the metabolites formed are methoxyhydroxyphenylglycol (MHPG) and methoxyhydroxymandelic acid—frequently named vanillylmandelic acid (VMA). Do-pamine may be directly deaminated conducting to dihydroxyphenylethanol and dihydroxyphenylacetic acid (DOPAC), or methoxylated then deaminated, giving methoxyhydroxyphenylacetic acid—known as homovanillic acid (HVA) (Figure 4).
Familial Neuroblastoma
Dongyou Liu in Handbook of Tumor Syndromes, 2020
Diagnosis of neuroblastoma involves medical history review (family history, earlier median age of diagnosis) physical examination (e.g., blood pressure; unusual mass in the abdominal, mediastinum, and paravertebral regions; bilateral/multifocal primary tumors), laboratory testing (e.g., gas chromatography and mass spectroscopy [GC-MS] detection of urinary catecholamine metabolites including vanillylmandelic acid [VMA] and homovanillic acid [HVA] in 90% of cases; metaiodobenzylguanidine [MIBG] mapping), imaging study (e.g., chest radiograph, abdominal ultrasound), histopathology (of tissue/bone marrow biopsy, bone marrow infiltration by tumor), and molecular confirmation (including cytogenetic evaluation of neoplastic cells; identification of ALK and PHOX2B mutations) [34].
Genetic Disorders of the Autonomic Nervous System
David Robertson, Italo Biaggioni in Disorders of the Autonomic Nervous System, 2019
Noradrenaline metabolites have been low or absent in plasma, urine and cerebrospinal fluid (CSF). Conversely, dopamine metabolites such as homovanillic acid and 3-methoxytyramine are raised. Determination of whether or not noradrenaline exists at all in patients with DBH deficiency must await further investigations and improvements in assay methodology. A low, but apparently detectable, level of vanillylmandelic acid was found in the urine of three patients (Robertson et al., 1986a; Mathiaset al., 1990), and a low, but detectable, level of 3-methoxy-4-hydroxyphenylglycol was found in the CSF of another patient (Manin’t Veldet al., 1987a). In other patients, these metabolites have been beneath the limits of detection of the assay. Whether these reflect genuine differences in pathology or the limitations of the respective assays remains to be seen.
Synchronous Hepatoblastoma and Neuroblastoma in Two Chinese Infants
Published in Fetal and Pediatric Pathology, 2023
Bo Shao, Yi-zhen Wang, Yuan Fang, Jing Chu, Lian Chen, Le-Jian He
Case 1: A ten-month-old boy presented with a 10 day history of increasing abdominal circumference which led to the discovery of an occupying lesion in the liver by abdominal ultrasound. There was no significant history or family history. Physical examination showed the patient had an extensive palpable epigastric mass, approximately 10.0 cm × 10.0 cm × 2.0 cm, with clear boundary, poor mobility, and no tenderness. The CT (Fig. 1A) scan revealed a large solid mass of the right hepatic lobe measuring 10.5 cm × 8.2 cm × 7.5 cm, with uneven density (Fig. 1B). Mediastinum window displayed a mass in the right paraspinal region with soft tissue density measuring 2.2 cm × 1.6 cm × 1.0 cm, with spotty high-density opacities inside, and the mass enhanced slightly after contrast administration (Fig. 1C). The liver mass was considered as a possible HBL, while the mediastinal lesion was considered as a metastasis or neurogenic tumor. Blood tests showed the initial α-fetoprotein (AFP) level was 86,226.20 ng/mL (reference ranges: 0–8.0 ng/mL). Urinalysis tests showed the urine vanillylmandelic acid (VMA) level was 2.46 mg/24 h (reference range 0–35 mg/24 h). The patient underwent radical resection of the liver tumor and the mediastinal tumor. Two cycles of carboplatin and doxorubicin and three cycles of cisplatin and doxorubicin were given after surgery. The patient had no recurrences/relapses or metastasis during 36 months follow-up after operation.
Urine catecholamines in children with severe Enterovirus A71 infection: comparison with paediatric septic shock
Published in Biomarkers, 2019
Sheng-Ling Jan, Ming-Chih Lin, Sheng-Ching Chan, Hsiu-Fen Lee, Po-Yen Chen, Fang-Liang Huang
Urine samples were collected for 24 h using a urinary catheter with a urine drainage bag or disposable paediatric urine bag within 24 h of diagnosis of septic shock or severe EV-A71 infection stage 2 or 4 for determination of urine catecholamine concentrations soon after obtaining informed consent. Aliquots were stored at 4 °C after urine sample collection, acidified with concentrated hydrochloric acid for adequate acidity (pH 2–4) and the samples were protected from light. All acidified samples were kept at −20 °C until analysis. If 24 h urinary collection was incomplete due to inotropic therapy in critical patients, untimed urine was collected for analysis before inotrope administration. Epi, NE, dopamine (DA) and vanillylmandelic acid (VMA) in urine were measured by high-performance liquid chromatography coupled with electrochemical detection using a commercially available method (Bio-Rad Laboratories, Milan, Italy). All urine samples were assayed in duplicate and values were retained if they were within 10% of each other. Urinary creatinine concentration was measured for each urine sample. Urine catecholamine and VMA concentrations were corrected for the corresponding urine creatinine concentration and expressed as a ratio to creatinine concentration (ug/gCr for catecholamines and mg/gCr for VMA).
Opsoclonus myoclonus and ataxia syndrome with supraventricular tachycardia
Published in Baylor University Medical Center Proceedings, 2023
Sydney Garner, Alec Giakas, Katherine Holder, Bernardo Galvan, Hollie Edwards
A 9-month-old male was born via cesarean delivery at 34 weeks’ gestation due to maternal preeclampsia and fetal heart rate decelerations. His past medical history was significant for macrocephaly and hypotonia. A month before presentation, he developed abnormal eye and body movements. He was noted to be more tired and to be eating less than usual. Upon examination, he was alert and had intermittent, rapid, low-amplitude, chaotic eye movements, abnormal jerking of the head and arms, and low truncal tone. Muscle bulk and reflexes were normal except for an exaggerated Moro reflex. An extensive initial workup included magnetic resonance imaging of his brain consistent with benign enlargement of subarachnoid spaces of infancy. Computed tomography of the neck, chest, abdomen, and pelvis and urinary vanillylmandelic acid (VMA) and homovanillic acid (HVA) levels were within normal limits and did not reveal a neuroblastoma.
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