A 30-year-old man had an acute onset of orthostatic lightheadedness, sweating disturbance, paroxysmal cough and loss of potency. These symptoms reached the peak in two weeks, and then remitted very slowly. He was admitted to our hospital for further evaluation when he was 39 years old. Neurological examinations revealed right Horner's syndrome, dry skin and impotence, but neither motor nor sensory system was impaired. No abnormalities were found on routine examinations of the blood and cerebrospinal fluid, motor and sensory nerve velocities, computed tomography and electroencephalography. On sural nerve biopsy, the density of unmyelinated fibers was mildly decreased (13,857/mm2), whereas that of myelinated fibers was normal (7,220/mm2). Autonomic function tests disclosed orthostatic hypotension (-31 mmHg) on tilting, reduced levels of serum noradrenaline and vanillyl mandelic acid, supersensitive responses to noradrenaline infusion and adrenaline eye-dripping, severe sweating impairment and complete absence of sympathetic skin response. On the other hand, Aschner's test, Czermak's test and coefficient variation of R-R intervals were all normal. These results suggested that the chief lesion was located in the postganglionic fiber of sympathetic efferent pathway. We (Hayashi et al, 1990) quantified acetylcholinesterase (AchE)-positive fibers in the specimens of sural nerve biopsy, and reported that the density of AchE-positive fibers was correlated to the function of sympathetic postganglionic fibers. The density of AchE-positive fibers in the present case of acute idiopathic pandysautonomia (AIPD) was severely decreased to 225/mm2 by optical microscopy (control: 5,703 +/- 1,289/mm2), and to 2,996/mm2 by electron microscopy (control: 14,112 +/- 3,987/mm2).(ABSTRACT TRUNCATED AT 250 WORDS)

We report a case of a dopamine-secreting giant primary adrenal ganglioneuroma (GN) in a 29-year-old male patient. Although the patient was clinically silent, the 24-hour urine levels of dopamine, normetanephrine, homovanillic acid and vanillyl mandelic acid were elevated. Abdominal ultrasonography and magnetic resonance imaging showed a large solid tumor with calcifications and a slightly lobular edge on the left adrenal gland. A tumor, 13 x 23 x 25 cm in size, was completely resected without morbidity. A 2-year follow-up with computed tomography showed that the postoperative course of the patient was uneventful.

This study was aimed to observe that extremely low frequency magnetic field (ELF-MF) may be relevant to changes of major neurotransmitters in rat brain. After the exposure to ELF-MF (60 Hz, 2.0 mT) for 2 or 5 days, we measured the levels of biogenic amines and their metabolites, amino acid neurotransmitters and nitric oxide (NO) in the cortex, striatum, thalamus, cerebellum and hippocampus. The exposure of ELF-MF for 2 or 5 days produced significant differences in norepinephrine and vanillyl mandelic acid in the striatum, thalamus, cerebellum and hippocampus. Significant increases in the levels of serotonin and 5-hydroxyindoleacetic acid were also observed in the striatum, thalamus or hippocampus. ELF-MF significantly increased the concentration of dopamine in the thalamus. ELF-MF tended to increase the levels of amino acid neurotransmitters such as glutamine, glycine and γ -aminobutyric acid in the striatum and thalamus, whereas it decreased the levels in the cortex, cerebellum and hippocampus. ELF-MF significantly increased NO concentration in the striatum, thalamus and hippocampus. The present study has demonstrated that exposure to ELF-MFs may evoke the changes in the levels of biogenic amines, amino acid and NO in the brain although the extent and property vary with the brain areas. However, the mechanisms remain further to be characterized.

Pheochromocytoma is a neuroendocrine tumor arising from the adrenal medulla. A number of variants of pheochromocytoma are known; however, pigmented pheochromocytoma is extremely rare, with only few cases reported in literature. We report the cases of two patients with pigmented pheochromocytoma. Case 1 was a 28-year-old female who presented with complaints of breathlessness, palpitations, and anxiety for 5 years, which had worsened over the last 8 months. Computed tomography (CT) abdomen showed a right suprarenal mass. Case 2 was that of an 18-year-old girl who presented with similar complaints and was diagnosed with hypertension. CT abdomen showed bilateral adrenal masses. Urinary vanillyl mandelic acid was raised in both patients. Sections examined from all three tumors showed cells arranged in Zellballen pattern, separated by thin fibrovascular septae. Tumor cells showed moderate to marked nuclear pleomorphism in case 1. Mitoses were, however, not seen. There was no evidence of capsular or vascular invasion. Many of the tumor cells showed intracytoplasmic black pigment, which was positive for Fontana-Masson and was bleach-labile, confirming it as melanin. Hemosiderin deposition was also identified. Large areas of hemorrhagic necrosis were seen in case 1. Tumor cells were immunopositive for chromogranin and synaptophysin, while they were negative for HMB-45. Electron microscopy was performed. A final diagnosis of pigmented pheochromocytoma was rendered in both cases. Pigmented pheochromocytoma is a very rare tumor, which needs to be differentiated from other pigmented tumors like malignant melanoma of adrenal gland and pigmented adrenal adenoma. Histochemistry and immunohistochemistry help in making this distinction.

BACKGROUND

Phaeochromocytoma is a rare surgically treatable cause of hypertension. The aim of this paper is to present a case of phaeochromocytoma treated in Port Harcourt.

METHODS

The case record of a patent with phaeochromocytoma and a review of the relevant literature.

RESULTS

A 40 year-old man presented with episodic malignant hypertension resistant to several anti-hypertensive drugs. A 24-hour urinary Vanillyl Mandelic Acid estimation was high at 68 mmol. An ultrasound scan revealed a huge right suprarenal mass. Preoperative medication was given to reduce the blood pressure and prevent perioperative arrhythmias. Under general anaesthesia with propofol, the tumour was explored. It appeared to invade the kidney and there were multiple hepatic secondaries. It was resected in block with the kidney. Intra- and postoperatively he had episodes of hypertension which were successfully controlled with a combination of intravenous chlorpromazine 50 mg, tramadol 100 mg and lorazepam 4 mg. Histopathology examination showed that the suprarenal mass and hepatic lesions were identical showing malignant phaeochromocytoma. The post-operative period was satisfactory. Cytotoxic drugs were not given because they were not available. On review 8 weeks later, the patient remained well.

CONCLUSIONS

Meticulous anaesthetic and surgical skills are essential in the resection of a phaeochromocytoma.

Snake venom 5'-nucleotidase (5'NUC) plays a very important role in envenomation strategies; however, apart from its modulation of hemostatic functions, its other pharmacological effects are not yet well characterized. Several studies have used specific inhibitors of enzyme toxins as a biochemical or pharmacological tool to characterize or establish its mechanism of action. We report here for the first time vanillin mandelic acid (VMA), an analog of vanillin, to potentially, selectively, and specifically inhibit venom 5'NUC activity among other enzymes present in venoms. VMA is much more potent in inhibiting 5'NUC activity than vanillyl acid (VA). The experimental results obtained are in good agreement with the in silico molecular docking interaction data. Both VA and VMA are competitive inhibitors as evident by the inhibition-relieving effect upon increasing the substrate concentration. VMA also dose-dependently inhibited the anticoagulant effect in Naja naja venom. In this study, we report novel non-nucleoside specific inhibitors of snake venom 5'NUC and experimentally demonstrate their involvement in the anticoagulant activity of N. naja venom. Hence, we hypothesize that VMA can be used as a molecular tool to evaluate the role of 5'NUC in snake envenomation and to develop prototypes and lead compounds with potential therapeutic applications against snake bites.

The present study is the first attempt to report the characterization of a nucleotidase from Cerastes cerastes venom. A 70 kDa 5'-nucleotidase (Cc-5'NTase) was purified to homogeneity. The amino acid sequence of Cc-5'NTase displayed high homology with many nucleotidases. Its activity was optimal at pH 7 with a specific hydrolytic activity toward mono-, di-, and triphosphate adenylated nucleotides. Cc-5'NTase preferentially hydrolyzed ADP and obeyed Michaelis-Menten kinetics. Among the metals and inhibitors tested, Ni2+ and Mg2+ completely potentiated enzyme activity, whereas EGTA, PMSF, iodoacetamide, vanillic acid, vanillyl mandelic acid, and 1,10-phenanthroline partially abolished its activity. Cc-5'NTase was not lethal for mice at 5 mg/kg and exhibited in vivo anticoagulant effect. It also dose-dependently inhibited adenosine diphosphate-induced platelet aggregation by converting adenosine diphosphate to adenosine and prohibited arachidonic acid-induced aggregation but was not effective on fibrinogen-induced aggregation. Cc-5'NTase could be a good tool as pharmacological molecule in thrombosis diagnostic and/or therapy.

A fast and sensitive high-performance liquid chromatographic method has been developed for the determination in human plasma of MHPG (3-methoxy-4-hydroxyphenylethylenglycol) and VMA (vanillyl mandelic acid), the main metabolites of epinephrine and norepinephrine. Analyses were carried out at 325 nm while exciting at 285 nm on a reversed-phase column (Atlantis C18, 150 mm x 4.6 mm I.D., 5 microm) using a mobile phase composed of 2% methanol and 98% aqueous citrate buffer at pH 3.0. A careful solid-phase extraction procedure, based on mixed-mode reversed-phase - strong anion exchange Oasis cartridges (MAX, 30 mg, 1 mL), was developed for the pre-treatment of plasma samples. Extraction yields were satisfactory, always higher than 90%. Calibration curves were linear over the 0.2-40.0 ng mL(-1) concentration range for MHPG and over the 0.5-40.0 ng mL(-1) concentration range for VMA. The method was successfully applied to plasma samples of former drug users undergoing detoxification therapy and subjects "at risk" of developing drug addiction.

Neuron-specific enolase (NSE) in sera of 3 patients with neuroblastoma (Stage IV) were measured by radioimmunoassay, as compared with urinary catecholamine metabolites (vanillyl-mandelic acid (VMA) and homovanillic acid (HVA] during the course of chemotherapy, radiation, and second look operation. In Case 1 (Stage IV B) and Case 3 (Stage IV A), NSE-level on admission was found to be elevated to 51.0 ng/ml and 25.5 ng/ml, respectively. VMA and HVA were also elevated. In Case 2 (Stage IV A), NSE on admission was elevated to 128.0 ng/ml., HVA was high, but VMA was within normal range. From 1 to 3 weeks after chemotherapy and radiation, high levels of urinary VMA and/or HVA in patients promptly decreased within normal range. The size of primary tumor masses either showed no marked change or slightly decreased by radiological examinations. After intensive chemotherapy, high levels of serum NSE decreased within normal range. At that time, second look operations were carried out. The size of primary tumors was reduced (3.6 X 2.7 X 2.1 cm in average) and almost all masses had scarred over. These data suggest that serum NSE levels correlate very well with residual tumor burdens.

The twenty-four hour urinary excretion of vanillyl mandelic acid was determined in a group of eleven psychiatric patients prior to and during the day of the fifth unilateral electroconvulsive treatment. The patients were all determined by their treating psychiatrists and by psychological testing to be psychotically depressed. In ten of the eleven patients a marked decrease in excreted vanillyl mandelic acid was apparent from the pretreatment level to the fifth treatment level. In one of the eleven patients there was a slight rise from the pretreatment level to the excreted level during the fifth day of treatment. The mean pretreatment determination of vanillyl mandelic acid was 4.2 mg per twenty-four hours; the mean determination made on the fifth treatment was 2.8 mg per twenty-four hours.

The diagnosis of phaeochromocytoma can be extremely difficult with 40%-76% of cases escaping diagnosis during life. Until recently, the only available biochemical test for the detection of phaeochromocytoma in Singapore has been the 24-hour urinary vanillyl mandelic acid (VMA). Urinary VMA has been reported to have a high specificity (85%-100%) but variable sensitivity (28%-90%) in the diagnosis of this disease. In 1993, high performance liquid chromatography (HPLC) assays for the measurement of urinary catecholamines and metanephrines were introduced at the Singapore General Hospital. Since 1993, 4 cases of phaeochromocytoma have been detected at our institution. We report here, the diverse clinical presentations of these patients. The urinary-free catecholamine and catecholamine metabolite levels of these patients were compared with corresponding levels from 12 non-phaeochromocytoma patients. Using the reference value of 65.6 mumol/day, we found the urinary VMA to be a highly sensitive (100%) test with a specificity of only 31%. In contrast, a urinary total metanephrine level>> or = 9,000 nmol/day was both sensitive (100%) as well as specific (100%).

Pheochromocytoma was diagnosed in a female patient aged 26 with paroxysmal arterial hypertension (AH), profuse sweating, headache, anxiety, tachycardia, transit arrhythmia, high urinary norepinephrine (NE), epinephrine (E) and vanillyl mandelic acid (VMA). Urography with intravenous Odiston revealed a relatively large tumor at the upper pole of the right kidney. Complete removal of the tumor in a 2-step surgical procedure brings apparent clinical and hormonal recovery for 6 years, but then clinical and hormonal relapse occurs through ganglionary metastasis and tumor at the basis of the mesentery. Removal of the metastasis and tumor brings again improvement in the clinical and hormonal picture.

Metabolic studies on isolated rat organs showed that vanillyl mandelic acid (VMA) is dehydrogenated by liver homogenate and suspension of pseudomonas fluorescens. In the 100000 g supernatant fraction of homogenated rat kidneys enzymatic activity was sufficient for kinetic studies and the examination of substrate specificity, pH dependence and changes with age and sex of rats. Norepinephrine secretion and resorption may be influenced by antiarrhythmic drugs in vivo: after lidocaine, there was no change of the tyramine dependend norepinephrine depletion of rat hearts, Verapamil inhibited the uptake of norepinephrine by rat hearts. Immobilisation of the animals led to a significant decrease in the myocardial levels for norepinephrine and epinephrine, which was antagonised by recreation of 24 hours. Adumbran prevented the catecholamine depletion, so that the influence of the limbic system may be important for the mediation of sympathetic stimuli.

METHODS

Emotional stress was shown to lead to an elevated plasma level of norepinephrine, cortisole and free fatty acids. In patients undergoing surgery, the application of Valium and Fortral inhibited these stress reactions. After physical stress, which did not lead to significant changes of the catecholamine level in plasma of healthy volunteers, there was an elevated norepinephrine plasma level in patients with cardiac failure, which could be prevented by different antiarrhythmic drugs. The excretion of norepinephrine and VMA of these patients was also increased. It was shown, that sinus rate rose according to norepinephrine levels in plasma in this group, which was contrary to the behaviour of healthy volunteers, showing neither a norepinephrine overflow nor increased heart rate. In patients with atrial fibrillation, AV-conduction also increased with elevated norepinephrine levels in plasma. There was, however, no direct correlation. Determination of the cardiac AV-difference of plasma-norepinephrine levels showed a cardiac catecholamine overflow, which could be inhibited by specific and nonspecific antiarrhythmic drugs (Verapamil, Practolol). In studies of catecholamine and glucocorticoid metabolism, no significant difference of catecholamine and VMA could be determined in patients with normal blood pressure and arterial hypertension. There was, however, a tendency to increased values in patients of the last group. In postural hypotension, plasma levels and urinary excretion of catecholamines were decreased and showed no variation after physical stress in orthostasis and after nicotine. In patients with tumors of the adrenal cortex and medulla, a close relation of the disturbance in catecholamine and corticoid metabolism was revealed.

The effect of Datura alba (seed) extract on the brain and urinary metabolites of rats was studied. Treatment with Datura brought about a decrease in the activity of brain lipid peroxidase and catalase while an increase in the activity of fructose diphosphate aldolase and glucose 6-phosphate dehydrogenase was observed. An increase in the DNA and RNA contents of brain was noted after the treatment with Datura. The study also showed a marked decrease in the excretion of 5-hydroxyindole acetic acid and vanillyl mandelic acid in the urine of rats given Datura extract.