Masuhide Miyao

Enzymologic Studies and Therapy of Leigh's Disease Associated with Pyruvate Decarboxylase Deficiency

Summary: An 11-month-old boy with muscle hypotonia and neurologic deteriorations had lactic acidosis, pyruvic acidemia and alaninemia due to deficiency of the pyruvate dehydrogenase complex in his platelets and of pyruvate decarboxylase in his muscle. When placed on a low carbohydrate-high fat diet for 6 months, his blood levels of lactate and pyruvate became nearly normal, but his cerebrospinal fluid levels of lactate and pyruvate remained high. Despite this dietary therapy, neurologic deterioration progressed slowly. He died of pneumonia after artificial respiration for 3 wk. At autopsy, extensive symmetric necrotic lesions were found in the brain including proliferation of capillaries and gliosis in the brain stem and diffuse demyelination in the white matter. These lesions were consistent with those observed in Leighs disease. The activities of the pyruvate dehydrogenase complex and pyruvate decarboxylase in various tissues obtained at autopsy were less than 10% of control values; however, the activities of pyruvate carboxylase and α-ketoglutarate decarboxylase were within the normal limits. This patient with Leighs disease had an isolated deficiency of pyruvate decarboxylase in various tissues.Speculation: Deficiency of pyruvate decarboxylase in brain may be one cause of clinical and pathologic features of Leighs disease. The absence of pyruvate decarboxylase in the cerebellum, cerebrum, kidney, liver, muscle and platelets of the patient supports the hypothesis that there is only one form of pyruvate decarboxylase in humans.

Short latency somatosensory evoked potential in children

The short latency somatosensory evoked potential was studied in 90 normal children of 1 month to 16 years old and 7 adults. Somatosensory stimuli were delivered through a disc electrode placed over the median nerve at the wrist joint. The uniform recording sites used were the central region of the scalp, and the seventh cervical spine or Erbs point. Reference electrodes were placed on the hand contralateral to the median nerve stimulated. Three positive peaks (P1, P2 and P3) and one negative peak (N1) were consistently recorded, a further positive peak (P4) after N1 was not always observed. The latency of each peak per 1 m body length decreased with age until 2 or 5 years of age. The latency of each peak after 2 years of age was positively correlated with the body length and arm length. The value of P1 peak latency per 1 m body length reaches adult values at an earlier rate than the value of P3 peak latency and P2-P3 latency per 1 m body length. This suggests that central lemmiscal pathways mature at a slower rate than peripheral nerve fibers. The wave form pattern of the short latency somatosensory evoked potential changed to the adult pattern at 10 years of age. The peak latency of P4 during deep sleep was slightly prolonged. In recording on infants during sleep, the EEG should be monitored to determine the stage of sleep.

Treatment of chronic congenital lactic acidosis by oral administration of dichloroacetate

Sodium dichloroacetate (DCA) was administered orally at a dose of 50 mg per kg body weight twice or three times per day to a newborn infant with lactic acidosis of unknown cause (patient 1) and to a 15-year-old boy with mitochondrial encephalomyopathy associated with lactic acidosis (patient 2). In patient 1, during treatment with DCA, DCA accumulated in the blood judging from the findings that the urinary excretion of DCA increased cumulatively and the blood lactate level rapidly decreased to the normal range. In patient 2, the blood DCA level gradually increased during treatment to a concentration of 250 µgml−1 and the blood lactate level decreased and was maintained within the normal range. DCA was detected in the brain (25 µg g tissue−1) and the liver, kidney and muscle (33.8, 33.8 and 26.3 µg g tissue−1, respectively) obtained at autopsy of patient 1, and in the cerebrospinal fluid of patient 2 at a concentration of 125 µg ml−1 when the blood concentration was 250 µg ml−1. The lactate levels in the cerebrospinal fluid decreased from 7 and 4mmoll−1 to 2.4 and 2.6 mmoll−1 in patients 1 and 2, respectively. Thus DCA may be useful in clinical treatment of chronic congenital lactic acidosis because it seems to cross the blood-brain barrier. However, it must be given at non-toxic doses, determined by monitoring the concentrations of lactate and DCA in the blood, because orally administered DCA tends to accumulate in tissues.

Effects of Dichloroacetate on Pyruvate Metabolism in Rat Brain in Vivo

Summary: The effects of dichloroacetate (DCA) on the activity of the pyruvate dehydrogenase (PDH) complex and associated changes in the lactate and glucose levels in rat brain were investigated in vivo. The average activities of the active form of the PDH complex in the brain, liver and muscle of starved rats were respectively 0.40 ± 0.04, 0.07 ± 0.04, and 0.17 ± 0.11 μmol/min/g tissue, and amounted to 21, 11, and 16% of the total activity of the complex. Intraperitoneal injection of DCA (125 mg/kg) increased the percentage of the active form of the PDH complex in the brain, liver, and muscle to 107, 40, and 84%, respectively. DCA significantly lowered the lactate and glucose concentrations of the brain and blood. A lower dose of DCA (12.5 mg/kg) also caused significant increase in activity of the PDH complex in the brain, but did not significantly change the lactate or glucose concentration of the brain. These results suggest that DCA crosses the blood-brain barrier reasonably well.

Postural Effects on Behavioral States of Newborn Infants -A Sleep Polygraphic Study-

Physiological and behavioral correlates of neonates in the supine and prone positions were examined. Polygrams were recorded in 10 newborn infants in the prone and supine positions. Newborn infants slept more in the prone position than in the supine, and quiet sleep was significantly more in the prone position. Gross movement, jerky movement and twitch movement were less in the prone than the supine position. There was no difference in localized movement or tremor-like movement in the two positions. Respiration was more regular in the prone than the supine position. Sleep apnea (greater than or equal to 6 seconds) was less in the prone position. The pulse rate during quiet sleep was higher in the prone position.

Increased body movements during sleep in gilles de la tourette syndrome

Overnight sleep polygrams were recorded form 9 patients with Gilles de la Tourette syndrome (GTS). Six of 9 patients had abnormal electroencephalograms, but no specific abnormalities were detected. Body movements and twitch movements during sleep were analyzed. At all stages of sleep, body movements during sleep were more frequent in cases of GTS than those in normal controls. Twitch movements in stage REM of sleep were significantly increased in GTS. These results are consistent with the idea that GTS is due to an imbalance between the central neurotransmitters, catecholamine and serotonin.

Detection of pyruvate metabolism disorders by culture of skin fibroblasts with dichloroacetate.

ABSTRACT: For use in screening for disorders of pyruvate metabolism, a sensitive assay method was developed for measuring the rate of decarboxylation of [1-14C]pyruvate during in vitro culture of skin fibroblasts with dichloroacetate (DCA). The rate of decarboxylation of [1-14C]pyruvate by skin fibroblasts from control subjects increased from 59.6 ± 13.2 to 97.3 ± 12.0 nmol/h/mg protein during in vitro culture in medium supplemented with 10 mM DCA for 3 days. In contrast, the rate hardly increased in cells from four of 20 patients with congenital lactic acidosis of unknown cause during in vitro culture with DCA. On day 3 of culture, the values for the four patients did not overlap those of control cells and so these four patients could be clearly distinguished from control subjects. Measurements of the original activity and the activity of the pyruvate dehydrogenase (PDH) complex after activation with a broad specificity protein phosphatase and DCA suggested that in three of the patients the aberration was a disorder in the mechanism for activation of PDH, including deficiency of PDH phosphatase or a mutation of PDH itself, whereas that in the fourth patient it might be a disorder of the mitochondrial transport system for pyruvate. Thus, measurement of the rate of decarboxylation of [1-14C] pyruvate by skin fibroblasts cultured in medium supplemented with 10 mM DCA for 3 days is a useful method for screening for disorders of pyruvate metabolism in cultured skin fibroblasts.

Plasma atrial natriuretic peptide levels in patients with ventricular septal defect

involvement of the neural crest. Proc Greenwood Genetics Ctr 1985;4:81. 11. Bharati S, Kirklin JW, McAllister HA Jr, Lev M. The surgical anatomy of common atrioventricular orifice associated with tetralogy of Fallot, double outlet right ventricle and complete regular transposition. Circulation 1980;61:1142. 12. Toussaint M, Planche C, Graft WC, Royon M, Ribierre M. Double outlet right ventricle associated witli common atrioventricular canal: report of nine anatomic specimens. J Am Coll Cardiol 1986;8:396.

Rapid diagnosis of vitamin D-dependent rickets type II by use of phytohemagglutinin-stimulated lymphocytes

The interactions of 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] with phytohemagglutinin (PHA)-stimulated lymphocytes from normal subjects and three patients with vitamin D-dependent rickets (DDR) type II were investigated. Impaired nuclear uptake and normal cytosol binding of [3H]1,25-(OH)2D3 were observed with PHA-stimulated lymphocytes of these patients as with their cultured skin fibroblasts. Furthermore, the incorporation of [14C]thymidine into PHA-stimulated lymphocytes of the patients was not reduced by 1,25-(OH)2D3, which is known to inhibit proliferation of various cells. These findings suggest that 1,25-(OH)2D3 receptors are reduced or absent in patients with DDR type II. Thus, the capacities of cytosol binding and nuclear uptake of 1,25-(OH)2D3 in PHA-stimulated lymphocytes seem to reflect those of endo-organs such as the intestine and bone. These findings show that a test of the effect of 1,25-(OH)2D3 on thymidine incorporation into PHA-stimulated lymphocytes is useful for rapid diagnosis of DDR type II.

Nature of copper and zinc compounds in tissues from a patient with Menkes kinky hair syndrome

Copper and zinc concentrations, and the nature of the copper- and zinc-binding proteins, were studied using tissues from a Menkes patient who had been given intravenous infusions of cupric acetate. The liver and brain copper contents were lower than in an untreated, non-Menkes control, and the spleen, intestine and kidney showed higher copper concentrations than control tissues. Zinc concentrations in all the organs (except the kidneys) from the Menkes patient were slightly lower than those the control child. Using Sephadex G-75 column chromatography of cytosols (105,000 x g supernatant), three copper- and zinc-containing peaks were eluted. In all the Menkes tissues studied, copper was prominent in peak 3. On the other hand, peak 3 was the smallest and peak 1 was the largest in the control tissues. Zinc predominated in peak 1 in both Menkes and control tissues, except for Menkes kidney. In this tissue peak 3 was again the largest. The copper- and zinc-binding material in peak 3 fractions from Menkes kidney was chromatographed on DEAE-cellulose columns. Three copper- and zinc-containing peaks were observed at the same positions as metallothionein from human adult kidneys.