Analysis of acylcarnitines in maternal urine for prenatal diagnosis of glutaric aciduria type 2

The urinary acylcarnitine profiles of two mothers whose first children were diagnosed to have glutaric aciduria type 2 (multiple acyl-CoA dehydrogenation deficiency, electron transfer flavoprotein (ETF) deficiency) were analysed in the second pregnancy. Large volumes of tigrylcarnitine and isovalerylcarnitine and a little glutarylcarnitine were detected. Each fetus was also diagnosed to be abnormal by enzyme activity and immunoassay of ETF protein. The acylcarnitines in the mothers' urine disappeared in 1 week after labour or artificial abortion. Acylcarnitines were never detected in the urine of controls.

[Carnitine palmitoyltransferase deficiency in a patient with severe psychomotor retardation]

A 13-year-old girl who had severe brain damage due to unknown prenatal cause presented rhabdomyolysis triggered by a mild viral infection. Her muscle biopsy revealed mild variation in fiber size and type 2 fiber atrophy without excess lipid storage. Biochemical analysis of the biopsied material showed decreased carnitine palmitoyltransferase (CPT) activity (15% of the control). Serum and urinary carnitine levels were normal. Skeletal muscle CT scanning showed multiple low density spots. The patient was diagnosed as having CPT deficiency. She recovered from rhabdomyolysis without renal failure after a month with conservative therapy. CPT deficiency is usually found in young healthy persons. This is the first case report of CPT deficiency which presented severe psychomotor retardation since neonatal period.

Macro creatine kinase in a case of carnitine palmitoyltransferase deficiency

A stout man was admitted to the hospital with acute rhabdomyolysis associated with macro creatine kinase (macro-CK, EC 2.7.3.2). This anomaly of CK was detected by gel electrophoresis as an atypical band between CK-MB and CK-MM, classified according to Stein's criteria (Clin Chem 1982; 28:19-24) as type 1, and identified by immunofixation electrophoresis as containing CK isoenzymes MM and MB and immunoglobulin A. Muscle biopsy showed that the etiology of rhabdomyolysis in this case was deficiency of carnitine palmitoyltransferase (CPT, EC 2.3.1.21) in the muscle. We report the first observation of macro-CK in a case of CPT deficiency; its presence may result from recurrent rhabdomyolytic attacks owing to CPT deficiency, and may suggest underlying enzymic abnormality in muscle.

Macro creatine kinase in a case of carnitine palmitoyltransferase deficiency

A stout man was admitted to the hospital with acute rhabdomyolysis associated with macro creatine kinase (macro-CK, EC 2.7.3.2). This anomaly of CK was detected by gel electrophoresis as an atypical band between CK-MB and CK-MM, classified according to Stein's criteria (Clin Chem 1982; 28:19-24) as type 1, and identified by immunofixation electrophoresis as containing CK isoenzymes MM and MB and immunoglobulin A. Muscle biopsy showed that the etiology of rhabdomyolysis in this case was deficiency of carnitine palmitoyltransferase (CPT, EC 2.3.1.21) in the muscle. We report the first observation of macro-CK in a case of CPT deficiency; its presence may result from recurrent rhabdomyolytic attacks owing to CPT deficiency, and may suggest underlying enzymic abnormality in muscle.

Anti-allergic effect of N-acetylneuraminic acid in guinea-pigs

The in-vivo anti-allergic effect of N-acetylneuraminic acid (NANA) in guinea-pigs passively sensitized with anti-ovalbumin rabbit serum has been studied. NANA (20 mg kg-1 i.v.) inhibited bronchial anaphylaxis and the release of histamine into bronchoalveolar lavage fluid. NANA dose-dependently inhibited heterologous passive cutaneous anaphylaxis and haemorrhaging in the passive Arthus reaction. However, it did not inhibit the release of histamine from sensitized minced lung tissue.

Presence and function of chondroitin-4-sulfate on recombinant human soluble thrombomodulin

We constructed a human soluble thrombomodulin (sTM) expression vector using the RSV promoter. Recombinant sTM (rsTM) was expressed in CHO cells and was recovered from culture medium by ion exchange chromatography. Two active fractions, designated as rsTM alpha (low salt elution) and rsTM beta (high salt elution), were detected and further purified by immunoaffinity chromatography. Purified rsTM beta contained bound chondroitin-4-sulfate as judged by HPLC detection of the chondroitinase ABC and AC I digestion product, 2-acetamido-2-deoxy-3-O-(beta-D-gluco-4-enepyranosyluronic acid)-4-O-sulfo-D-galactose. The apparent Kd values for thrombin of alpha and beta were 7.4 and 1.4 nM respectively. RsTM beta was more effective at inhibition of thrombin clotting activity and had antithrombin III-dependent anticoagulant activity which was not possessed by rsTM alpha. Both anticoagulant activities were lost after chondroitinase treatment of rsTM beta.

Carnitine deficiency in inherited organic acid disorders and Reye syndrome

A large quantity of propionylcarnitine in the urine of patients with propionic acidemia and methylmalonic aciduria was demonstrated. The amount excreted depended on the administered L-carnitine dose from 25 to 75 mg/kg/day. A high level of propionylcarnitine was also detected in the amniotic fluid of fetuses at risk of methylmalonic aciduria. Glutaric aciduria type 1 was characterized by excessive urinary excretion of glutarylcarnitine. In a neonate with glutaric aciduria type 2, several specific acylcarnitines were detected in the urine. These included isovaleryl-, acetyl-, isobutyryl-, and butyrylcarnitine as major carnitine esters and glutaryl-, and octanoylcarnitine as minor components. However, the pattern of acylcarnitines excreted changed from isovalerylcarnitine (via leucine) to isobutyrylcarnitine (via valine) during early life. In patients diagnosed as Reye syndrome, tissue carnitine deficiency was not always recognized and no decrease in the free/total carnitine ratio was found in the liver or muscle. The clinical and pathophysiological manifestations seen in these disorders are considered to relate to mitochondrial activity. Therefore, it is necessary to measure acylcarnitine fractions in the urine in order to obtain more precise information about mitochondrial function because carnitine and acylcarnitine compounds may express the metabolic state of mitochondria.

[Three cases of spontaneous rupture of the oesophagus (Boerhaave's syndrome)]

We reported three cases of spontaneous rupture which were surgically treated with direct suture method. One patient was operated on within eight hours after rupture with good results. In two patients diagnoses were made more than two days after rupture. One had esophageal fistula, but completely recovered after cervical oesophageal fistula, and another died of multiple organ failure. In this syndrome, early diagnosis and surgical treatment are essential for acceptable results. For early diagnosis, we emphasized on the presence of roentgenologic mediastinal and cervical emphysema. In patients for whom diagnosis was delayed and post-operative leakage at the oesophageal suture line occurred, temporarily fistulation of the cervical oesophagus proved to be effective in exclusion and diversion of the ruptured segment.

Effect of N-acetylneuraminic acid on respiratory tract secretion and inflammation in the bronchitic rabbit

Long-term exposure of rabbits to SO2 gas caused the following changes in the respiratory tract system: decreases in the respiratory rate and pO2 blood level; an increase in the viscosity of sputum associated with increases in protein, unsaturated phosphatidylethanolamine and sphingomyelin; subacute rhinitis, tracheitis and multiple bronchopneumonia. Pretreatment with repeated administrations (inhalations) of N-acetylneuraminic acid remarkably prevented these inflammatory changes. The significance of this finding is discussed.

An auto-inducible vector conferring high glucocorticoid inducibility upon stable transformant cells

A new gene expression system in mammalian cells was developed by using the glucocorticoid receptor (GR) as an inducible positive feedback factor. Mouse Ltk- cells were transfected with plasmids carrying the GR-encoding gene and the lacZ reporter gene, both of which were fused with the glucocorticoid-inducible enhancer/promotor of the mouse mammary tumor virus (MTV). The GR gene was first induced to supply the receptor protein, which further induced the expression of both GR and reporter genes. Stable transformants induced with dexamethasone, a synthetic glucocorticoid hormone, demonstrated beta-galactosidase activity 60-140-fold higher than uninduced controls. Similarly, the human alpha-interferon-encoding gene fused with the MTV enhancer/promoter was induced more than 12,000-fold. This system allowed us to increase the expression of the reporter or target genes without augmenting basal levels of expression significantly, and may be useful to investigate the unknown function of a cloned gene, particularly when the gene product of interest is cytotoxic or growth-inhibiting.

Identification of benzoylcarnitine in the urine of a patient of hyperammonemia

Benzoylcarnitine was identified in the urine of a patient with a carbamoyl-phosphate synthase I deficiency for whom sodium benzoate and L-carnitine had been used to treat hyperammonemia. This is a newly identified metabolite of benzoate. Its excretion in the urine was increased day by day at the administration of both sodium benzoate and L-carnitine from 0.10 to 2.25 mmol/g creatinine. Since there is the possibility of a secondary carnitine deficiency and an increase of benzoyl toxicity after long-term therapy with benzoate supplementation and protein restriction, it is important to monitor the urinary excretion of benzoylcarnitine.

[A case of dumbbell neurogenic tumors of the mediastinum]

A 49-year-old man was admitted for the further examination of the abnormal shadow of the left posterior mediastinum, which was incidentally detected on routine chest X-ray. He has no complaints, and no abnormalities on neurological examination. Thoracic spine X-ray showed the destruction of the T12 vertebral body and the dilatation of the left intervertebral foramen between T12 and L1. Myelography showed no abnormalities, but contrast-enhanced CT scanned just after myelography revealed the extradural dumbbell-formed tumor. One stage removal of the tumor was safely performed through left posterolateral thoracotomy and transthoracic partial laminectomy. Postoperative course was uneventful. The tumor was histologically schwannoma, originated from the left thoracic sympathetic trunk. We think that this procedure is available for the operation of a kind of dumbbell tumor of the posterior mediastinum.

[A female case of carnitine palmitoyltransferase deficiency]

A 17-year old woman noted myalgia after taking a long distance walk at the age of 10. In adolescence, she had several episodes of myalgia and pigmenturia after athletic activity or infection. At age 17, myoglobinuria and abnormally increased serum creatine kinase were documented after one of these episodes. The neurological examination revealed mild proximal muscle weakness of upper extremities. Electromyography showed myogenic patterns, such as brief, small abundant potentials on them. Venous lactate was raised normally on the ischemic exercise test. During prolonged fasting, plasma ketone bodies increased normally but there were abnormal elevations of plasma creatine kinase and myoglobin. Morphometric analysis of electron microscopy in muscle showed few lipid deposits and that of light microscopy revealed no abnormality. CPT activity in muscle was only 15% of normal value by the isotope-exchange assay. These results were consistent with the diagnosis of CPT deficiency. Although several cases of CPT deficiency with recurrent myoglobinuria have been reported in Western countries, our patients is the first case of Japanese showing recurrent myoglobinuria. CPT deficiency should be considered as a differential diagnosis in cases of recurrent myoglobinuria.

Disproportionate deficiency of iron-sulfur clusters and subunits of complex I in mitochondrial encephalomyopathy

To investigate the molecular abnormality in the mitochondria from various tissues of an autopsied patient exhibiting mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes, we have examined the enzymatic activity, iron-sulfur cluster, and subunit composition of the NADH-ubiquinone oxidoreductase (complex I). Rotenone-sensitive NADH-cytochrome c reductase activity was found to be decreased in all the tissues examined. A detailed study of the liver mitochondria has shown that NADH-ubiquinone oxidoreductase activity was greatly diminished. Analysis of the electron paramagnetic resonance spectra of the liver submitochondrial particles revealed a disproportionate deficiency of iron-sulfur clusters in the complex I segment of the respiratory chain. Signals from the clusters N-2 and N-3 diminished more drastically than those from clusters N-1b and N-4. Immunoblotting analysis showed that the 75-kD, 51-kD, and several other subunits were markedly diminished among multiple subunit polypeptides of complex I. These findings suggest that the underlying bases for mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes are defects, at least, in the complex I subunits containing a flavin and/or iron-sulfur cluster(s), which resulted in deficiencies of some iron-sulfur clusters.

Distribution of free N-acetylneuraminic acid in rat organs

The concentration of free N-acetylneuraminic acid in various rat organs was estimated by gas chromatography/mass spectrometry. Its concentration was in the range of 3.95 to 104.72 micrograms/g wet tissues, being particularly high in the endocrine glands. The ratio of free N-acetylneuraminic acid to total N-acetylneuraminic acid varied from 0.031 to 0.183, being especially high in the adrenal gland (0.181) and heart (0.183).

Urinary acylcarnitines in a patient with neonatal multiple acyl-CoA dehydrogenation deficiency, quantified by a carboxylic acid analyzer with a reversed-phase column

A quantitative analysis for urinary acylcarnitines in a patient with neonatal multiple acyl-CoA dehydrogenation deficiency is described. This method (liquid chromatography) can quantify twelve acylcarnitines including glutarylcarnitine and 3 isomeric acylcarnitines (butyryl-1, valeryl- and octanoylisomer) in urine. Before and up to the 15th hour of DL-carnitine therapy, isovalerylcarnitine was the largest single component existing in urinary acylcarnitines. Its excretion increased approximately 10 times within 1 day of DL-carnitine therapy. However, the acetyl-, the isobutyryl- and the butyrylcarnitine values increased gradually. From the 8th day of the therapy, the isobutyrylcarnitine value exceeded the isovalerylcarnitine. The patient's dominant urinary specific acylcarnitine derived from amino acids oxidation deficiency was changed from isovalerylcarnitine(leucine) to isobutyrylcarnitine(valine) during the early period of DL-carnitine therapy. Glutarylcarnitine was a minor component in the urine. Its degree of increase was as small as that of octanoylcarnitine. 2-Methylbutyrylcarnitine and propionylcarnitine were not detected.

A high-precision selective determination method for free N-acetylneuraminic acid in human serum

We established a high-precision selective determination method for free N-acetylneuraminic acid in human serum, involving capillary gas chromatography-mass spectrometry with selected ion monitoring and specific separation on a Sep Pak silica cartridge. In contrast to the value of 800 ng/ml of N-acetylneuraminic acid previously reported by Haverkamp et al. (J. Haverkamp, R. Schauer, and M. Wember (1976) Hoppe-Seyler's Z. Physiol. Chem. 357, 1699), who used the thiobarbituric acid method, the present method gave a value of 194 +/- 96 ng/ml for 22 serum samples from normal Japanese male volunteers aged between 20 and 30 years. The mass fragmentogram of serum showed a good signal/noise ratio, and the measurement was very specific, accurate, and reproducible.