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PubMed2004

[Diagnosis and treatment of methylmalonic acidemia in 14 cases].

OBJECTIVE: Methylmalonic acidemia (MMA) is one of the most common disorders of congenital organic acid metabolism. This study aimed at exploring the clinical characteristics and treatment of the disease to help improve our understanding of it. METHODS: The clinical data of 14 patients with MMA admitted to our hospital between January 2002 and July 2003 were analyzed and the diagnoses were confirmed by gas chromatography/mass spectrometry (GC/MS). The patients consisted of 4 males and 10 females, whose age of onset ranged from birth to 9 years with 7 cases younger than 1 month (50%) and 10 cases younger than 1 year (71%). RESULTS: The main clinical manifestations were lethargy (6 cases), developmental retardation or regradation (7 cases), convulsion (6 cases), recurrent vomiting (4 cases), difficulty with feeding (4 cases), muscular dystonia (5 cases with hypotonia, 3 with hypertonia) and yellowish hair (4 cases), etc. Some cases were also presented with hair loss, hepatomegaly, ataxic or stiff gait, and motor weakness with muscular atrophy. The laboratory findings showed metabolic acidosis in 6 cases, hyperammonemia in 5 cases, ketonuria in 4 cases and remarkable elevation of urinary methylmalonic acid concentration in all cases. Some abnormalities in globus pallidus and cerebral white matter as well as diffuse cerebral atrophy were noted by the brain CT and MRI in 5 respective cases, while 4 cases did not receive neuroradiological examinations. Peripheral neuropathies were found by electromyography in 2 patients and bilateral optic nerve atrophy was detected by eyeground examination in 1 child. Three patients died before the diagnoses were made. Of the 11 survivals, 10 children have received therapy of vitamin B12 (VitB12) and supplementation of L-carnitine with restricted-protein diet. The follow-up for a period ranging from 3 months to 1.5 year (mean 8.5 months) of 7 cases with medical therapy showed a favorable outcome without any symptoms in 1 case and apparent improvement in 4 cases (the diffuse cerebral atrophy in MRI completely recovered in one case), however, 2 patients died from severe metabolic acidosis. CONCLUSIONS: The main clinical features of MMA include lethargy, developmental retardation or regradation, convulsion, recurrent vomiting, difficulty with feeding, muscular dystonia, yellowish hair, metabolic acidosis, hyperammonemia and ketonuria, etc. Urine organic acids analysis with GC/MS is critical to the early diagnosis of MMA. Early diagnosis and appropriate long-term treatment are essential to improve the prognosis of the disease.

Acidosis↗

PubMed1992

[An autopsy case of citrullinemia type II complicated with chronic pancreatitis].

A 34-year-old woman had developed frequent episodes of disorientation at night since a year ago. Her blood ammonia level was found to be markedly increased. Serum amino acid pattern and biochemical analysis of urea cycle enzymes in the liver indicated type II citrullinemia. Pancreatolithiasis was found by ultrasonography and CT scan. After a short remission following treatment by protein restriction and oral administration of sodium benzoate, she had disturbed consciousness due to exaggerated hyperammonemia and died of severe brain edema. In this report, efficacy of the treatment for hyperammonemia and histopathological findings are discussed.

Adult↗

PubMed2006

A case of adult-onset type II citrullinemia--deterioration of clinical course after infusion of hyperosmotic and high sugar solutions.

BACKGROUND: Adult-onset type II citrullinemia (CTLN2) is an autosomal recessive disorder caused by mutations of SLC25A13 gene encoding citrin and is characterized by recurrent encephalopathy with hyperammonemia. Factors affecting disease progression remain unknown. We report a case with CTLN2, whose clinical course was rapidly worsened by the administration of Glyceol, a hyperosmotic diuretic solution consisting of 10% glycerol and 5% fructose in saline. CASE REPORT: A 34-year-old man was admitted in coma after repeated episodes of altered consciousness. His plasma ammonia level was markedly elevated without any evidence of liver diseases. Brain MRI revealed high signal intensities at the bilateral cingulate gyri and insular cortices, suggesting hepatic encephalopathy. We administered Glyceol. intravenously to alleviate brain edema, however, he developed intractable seizures along with steep increase in plasma ammonia levels (from 808 to 2210 microg/dL) and died. The diagnosis of CTLN2 was confirmed by elevations of plasma citrulline level (384.3 nmol/mL; normal 17-43 nmol/mL) and serum pancreatic secretory trypsin inhibitor (PSTI) (110 ng/mL; normal 4.6-12.2 ng/mL), decrease in hepatic argininosuccinate synthetase activity (5.5% of control), lack of hepatic citrin protein expression and mutations in SLC25A13 gene (compound heterozygote with S225X and Ex1-1G>A). CONCLUSIONS: Physicians should take CTLN2 into consideration as a differential diagnosis in Asian patients with a history of repeated unconsciousness with hyperammonemia and use D-mannitol but not glycerol to treat brain edema in patients with CTLN2.

Adult↗

PubMed1991

Recurrent acute encephalopathy due to fatty acid metabolic defect--report of two cases.

An increasing number of reports indicate that patients with some inherited metabolic diseases may have symptoms resembling those of Reye's syndrome. We describe 2 patients who developed Reye-like syndrome at the age of 7 months respectively. Conscious disturbance, hepatomegaly, impaired liver function, hyperammonemia, and nonketotic hypoglycemia were noted during acute episode. Blood lactate level was normal in both cases. Liver and muscle biopsy of both patients showed macrovesicular fatty change. Increased density of matrix in hepatocyte mitochondria was noted in patient 1. Stacking of cristae was shown in patient 2. The first patient had another episode of hyperammonemia at 2 years of age. The second patient was admitted three more times due to recurrent vomiting and conscious change at the age of 7 months, 10 months and 13 months respectively. Fatty acid metabolic defect should be considered in children or infants with recurrent Reye-like syndrome.

Acute Disease↗

PubMed1990

Impact of methylparathion and malathion on cholinergic and non-cholinergic enzyme systems of penaeid prawn, Metapenaeus monoceros.

The nervous tissue AChE, BUChE and glutaminase activity levels were significantly inhibited, whereas glutamine synthetase activity, acetylcholine and glutamine contents were increased significantly following the sublethal exposure of prawn, Metapenaeus, monoceros to methylparathion and malathion. During OPI exposure ammoniagenesis was triggered by increased deamination of purines and oxidative deamination of glutamate. This results in the hyperammonemia. As a consequence of hyperammonemia, the OPI exposed prawn tissue have adopted the suitable mechanisms to detoxity the ammonia by enhancing the synthesis of urea and glutamine. From the study, it has been observed that 10 days of reclamation period is not enough but the prawn nervous tissue showed efficient mechanisms for the detoxification or biodegradation of OPI molecules, which will pave way for the successful survival prawns.

Acetylcholine↗

PubMed1979

Hyperammonemic coma after hepatectomy in germ-free rats.

Current theories on the pathogenesis of hepatic coma indicate that intestinal bacteria produce cerebral toxins, such as ammonia, mercaptans, and short-chain fatty acids. To test the hypothesis that elimination of anaerobic and aerobic intestinal bacteria retards the onset and alters the biochemical profile of acute hepatic coma, we determined the onset of coma and the ammonia concentration in blood and cecal contents in 7 germ-free and 10 normal dehepatized rats. Ammonia levels were also determined in a further group of 7 germ-free and 12 normal rats 24 hr after hepatic vascular exclusion was accomplished. Onset of coma for germ-free rats (x: 34 hr) was identical to that of normal rats (x: 36 hr). Arterial ammonia was equally elevated in germ-free rats (x: 834 mumol/liter) and in normal rats (x: 854 mumol/liter), although the ammonia concentration in the cecal contents was significantly lower in germ-free rats (x: 1762 mumol/liter) than in normal rats (x: 5572 mumol/liter). In germ-free animals, portal venous blood contained more ammonia than arterial blood (x A-V difference: -87 mumol/liter), indicating nonbacterial intestinal ammonia release. We conclude that intestinal bacteria toxins are of minor importance in the mechanism of acute hepatic coma of the liverless rat and that presumably bacterial toxins, such as ammonia, can be products of nonbacterial metabolism. Since hyperammonemia could be considered an important determinant of coma in our model, prevention of hyperammonemia in functionally anhepatic animals should be the next objective in unraveling the pathogenesis of acute hepatic coma.

Ammonia↗

PubMed1984

The molecular basis for the two different clinical presentations of classical pyruvate carboxylase deficiency.

Eight cases of isolated human pyruvate carboxylase deficiency were examined from seven families. Although all patients presented with a chronic lacticacidemia, two particular patients presented with the added features of hyperammonemia, citrullinemia, and hyperlysinemia. When cultured skin fibroblasts from these patients were examined for their ability to synthesize [3H]biotin-containing proteins, it was found that the two patients who presented with hyperammonemia, citrullinemia, and hyperlysinemia did not synthesise a protein of the correct subunit molecular weight (Mr = 125 K daltons) corresponding to pyruvate carboxylase. In addition, when skin fibroblast proteins were labeled with [35S]methionine, cross-reacting material (CRM) corresponding to pyruvate carboxylase was immunoprecipitated by antipyruvate carboxylase antiserum in most patients, but again the two patients with the atypical presentation showed no CRM. We propose that the different clinical presentation of human pyruvate carboxylase deficiency is a manifestation of two different mutations in the pyruvate carboxylase gene, one that results in the synthesis of a relatively inactive pyruvate carboxylase protein CRM(+ve) and one that results in the lack of expression of the gene in the form of a recognizable protein CRM(-ve).

Biotin↗

PubMed1980

Ammonia encephalopathy secondary to urinary tract infection with Proteus mirabilis.

Hyperammonemia with coma, tachypnea, and respiratory alkalosis developed in a 3-year-old boy with prune"-belly syndrome during a urinary tract infection with Proteus mirabilis. Hyperammonemia is thought to have resulted from the production within the massively dilated urinary tract of excessive amounts of ammonia due to bacterial urease, and its subsequent reabsorption into the systemic circulation. The patient rapidly improved following parenteral antibiotic therapy and continuous catheter drainage of the urinary tract.

Abdominal Muscles↗

PubMed1983

[Plasma ammonia concentrations in mucoviscidosis].

In 16 children and adolescents suffering from mucoviscidosis the ammonia concentration of the plasma determined by a modified ion exchange method was compared with the clinical degree of severity. The ammonia values of the plasma were compared with several parameters, such as Shwachman stage, the presence of cardio-respiratory insufficiency, blood gas values and liver function tests. In 5 children with cystic fibrosis and cardio-respiratory insufficiency high plasma ammonia values were found. In older children with the disease lasting for a longer time with medium Shwachman stage (stage III) but without cardiorespiratory insufficiency the ammonia values were also relatively high. Cardiorespiratory insufficiency and disturbance of the liver function may play a role in the development of hyperammonemia. A distinct hyperammonemia refers to a bad prognosis in children with cystic fibrosis.

Adolescent↗

PubMed1982

[Lethal neonatal deficiency of carbamyl phosphate synthetase (author's transl)].

This is a report of a male neonate with hyperammonemia who showed progressive neurologic symptoms and pulmonary bleeding due to carbamyl phosphate synthetase deficiency. This newborn male died in coma after only 119 hours. His elder brothers died under similar circumstances in the first days of life, and a CPS-deficiency is not to be excluded. The pulmonary bleeding in the patient and in one brother caused by hyperammonemia is emphasized. In the pedigree repeated consanguinity could be detected.

Amino Acid Metabolism, Inborn Errors↗

PubMed1980

Variations in blood ammonia and glutamine levels after hepatectomy and/or abdominal evisceration in the rat.

In order to specify the role of peripheral muscular tissue in ammonia metabolism, we studied, in rats, the variations of ammonia and glutamine levels in arterial and femoral venous blood after hepatectomy and abdominal evisceration with nephrectomy. In non-fasting rats this operation was immediately followed by an important hyperammonemia which was due to ammonia muscular release; glutamine blood levels increased only slightly without any modification in their arterio-femoral venous differences. The hyperammonemia induced by hepatectomy-evisceration was greatly reduced in animals which had been fasting for 48 hours but was not modified by a 72hrs preoperative sucrose feeding. These nutritional conditions did not change the blood glutamine variations which were first related to the abdominal evisceration. Indeed, in abdominal eviscerated rats without hepatectomy there was an important hyperglutaminemia with only a slight increase in blood ammonia. These results indicate that in rat 1) the liver plays an important part in skeletal muscle ammonia metabolism, 2) this metabolism is related to food ingestion, 3) the gastrointestinal tissue intervenes in glutamine metabolism.

Ammonia↗

PubMed1993

[Type II citrullinemia triggered by acetaminophen].

We report a 19-year-old man with type II citrullinemia triggered by the administration of acetaminophen when he caught a cold. He was admitted to our hospital of impairment of consciousness and abnormal behaviors. On admission he was comatose and laboratory data revealed respiratory alkalosis which was probably induced by hyperammonemia. Liver dysfunction was mild. Plain CT scans showed brain edema, and EEG revealed triphasic waves. Analysis of plasma and urine amino acids showed a significant increase in citrulline and the activity of argininosuccinate synthetase was markedly reduced in a liver biopsy specimen. Histopathology of the liver revealed inflammatory changes which was probably induced by acetaminophen. Branched chain amino acids transfusion was effective for consciousness disturbance, and sodium benzoate was effective for hyperammonemia. We reviewed 28 patients reported in the literature from 1981 to 1992 to evaluate the probable triggering episodes in type II citrullinemia. Four categories of probable trigger were found, which included 1) stress, 2) liver dysfunction, 3) alcohol, and 4) drugs. Avoidance of these triggers, early diagnosis, and treatment seem most important for the good prognosis and the quality of life.

Acetaminophen↗

PubMed1976

[Present-day therapy of hepatic encephalopathy (author's transl)].

The ammonia hypothesis is the most likely explanation for the pathogenesis of hepatic encephalopathy in cirrhosis patients. Reduction of hyperammonemia is therefore the most consistent therapy. From this point of view, the antibiotics have a central significance for the reduction of ammonia formation in the intestinal tract. Equally important is the correction of the hypopotassemia, which may lead to a renally induced hyperammonemia. At the same time, disorders which favor the cerebral toxicity of ammonia, especially anemia and hypoxias, must be compensated. These various measures have improved the prognosis for hepatic encephalopathy of the cirrhosis patient, but were without effect on the course of the coma in severe toxic hepatitis. During the last toxic hepatitis. During the last 10 years, many treatment methods have been reported whose efficacy, however, could not be proved.

Acid-Base Imbalance↗

PubMed1993

Effect of valproate, sodium 2-propyl-4-pentenoate and sodium 2-propyl-2-pentenoate on renal substrate uptake and ammoniagenesis in the rat.

Experiments were carried out in the intact functioning rat kidney to study the effect of valproate (VPA), a widely used antiepileptic drug and an hyperammonemic agent, but usually without clinical relevance, and of two of its metabolites, sodium 2-propyl-4-pentenoate (4-en-VPA) and sodium 2-propyl-2-pentenoate (2-en-VPA), on the renal production of ammonia and on the renal uptake of glutamine, glutamate and of inhibitors of renal ammoniagenesis; mainly lactate, fatty acids, ketone bodies and alpha-ketoglutarate. Administration of VPA and 4-en-VPA stimulated the uptake of glutamine and glutamate and the production of ammonia by the rat kidney, resulting in an increase in the renal venous release of ammonia and in a hyperammonemia. By contrast, no hyperammonemia was observed after the administration of 2-en-VPA which stimulated renal ammoniagenesis to a lesser extent than VPA and 4-en-VPA, resulting in no stimulation of the renal venous release of ammonia. The three compounds tested caused, in a qualitatively different but, in terms of substrate carbons, in a quantitatively similar manner, a significant diminution of the renal uptake of fatty acids, ketone bodies and alpha-ketoglutarate. These results suggest that, in the rat kidney, VPA, 4-en-VPA and 2-en-VPA stimulate the production of ammonia at least in part by reducing the renal uptake and metabolism of ammoniagenesis inhibitors; the more potent stimulation of renal ammoniagenesis caused by VPA and 4-en-VPA also suggest that these compounds exert their stimulatory effect by an additional mechanism.

Ammonia↗

PubMed1995

Vitamin B12 in health and disease: part I--inherited disorders of function, absorption, and transport.

All of vitamin B12 in nature is of microbial origin. Cobalamin, as vitamin B12 should correctly be termed, is a large polar molecule that must be bound to specialized transport proteins to gain entry into cells. Entry from the lumen of the intestine under physiological conditions occurs only in the ileum and only when bound to intrinsic factor. It is transported into all other cells only when bound to another transport protein, transcobalamin II. Congenital absence or defective synthesis of intrinsic factor or transcobalamin II result in megaloblastic anemia. The Immerslund-Graesbeck syndrome, a congenital defect in the transcellular transport of cobalamin through the ileal cell during absorption, also presents with megaloblastic anemia, but with accompanying albuminuria. In most bacteria and in all mammals, cobalamin regulates DNA synthesis indirectly through its effect on a step in folate metabolism, the conversion of N5-methyltetrahydrofolate to tetrahydrofolate, which in turn is linked to the conversion of homocysteine to methionine. This reaction occurs in the cytoplasm, and it is catalyzed by methionine synthase, which requires methyl cobalamin (MeCbl), one of the two coenzyme forms of the vitamin, as a cofactor. Defects in the generation of MeCbl (cobalamin E and G diseases) result in homocystinuria; affected infants present with megaloblastic anemia, retardation, and neurological and ocular defects. 5'-Deoxyadenosyl cobalamin (AdoCbl), the other coenzyme form of cobalamin, is present within mitochondria, and it is an essential cofactor for the enzyme Methylmalonyl-CoA mutase, which converts L-methylmalonyl CoA to succinyl CoA. This reaction is in the pathway for the metabolism of odd chain fatty acids via propionic acid, as well as that of the amino acids isoleucine, methionine, threonine, and valine. Impaired synthesis of AdoCbl (cobalamin A or B disease) results in infants with methylmalonic aciduria who are mentally retarded, hypotonic, and who present with metabolic acidosis, hypoglycemia, ketonemia, hyperglycinemia, and hyperammonemia. Megaloblastic anemia does not develop in these children because adequate amounts of MeCbl are present, but the effect of methylmalonic acid on marrow stem cells may give rise to pancytopenia. Congenital absence of reductases in the cytoplasm, which normally reduce the cobalt atom in cobalamin from its oxidized to its reduced state (cobalamin C and D diseases), results in impaired synthesis of both MeCbl and AdoCbl. Both methylmalonic aciduria and homocystinuria therefore develop in these children, and they present with megaloblastosis, mental retardation, a host of neurological and ocular disorders, and failure to thrive; however, they do not have hyperglycinemia or hyperammonemia. A similar biochemical profile and clinical presentation is also seen in cobalamin F disease, which results from a defect in the release of cobalamin from lysosomes, following receptor-mediated endocytosis of the transcobalamin II-cobalamin complex into cells. It is important to recognize these inborn errors of cobalamin absorption, transport, or function as soon after birth as possible, because most respond (in some patients more fully than others) to parenteral administration of cobalamin. Delays in diagnosis can lead to grave clinical consequences.

Biological Transport↗

PubMed1996

[Anesthetic management of a patient with ornithine transcarbamylase deficiency].

A 6-year-old female with disturbance of consciousness (JCS: 3 points) due to hyperammonemia caused by ornithine transcarbamylase deficiency is presented. She underwent an emergency insertion of a catheter for peritoneal dialysis under general anesthesia. Anesthesia was induced by intravenous administration of thiamylal sodium and maintained with inhalation of sevoflurane and oxygen after tracheal intubation. One percent mepivacaine was infiltrated around the surgical field to diminish the dose of sevoflurane. The operation proceeded uneventfully, although her consciousness could not recover rapidly to the normal level during the emergence from anesthesia. Peritoneal dialysis was started immediately after the operation and her consciousness recovered to the normal level gradually during the following six days with decreasing plasma ammonia levels. Ten days later, extirpation of the peritoneal catheter was scheduled. The course of anesthesia and operation was uneventful using the same anesthetic method as with the former anesthesia. In the anesthetic management for a patient with ornithine transcarbamylase deficiency, we have to be careful about the nitrogen balance, which can be affected by the kind and doses of anesthetic drugs, to avoid hyperammonemia. From this point of view, local anesthesia combined with general anesthesia might be useful to prevent the serum ammonia level from increasing.

Ammonia↗

PubMed1996

[Massive ascites as an initial sign, plasmacytoma of the cervical supine, and hyperammonemic consciousness disturbance in a patient with biclonal type multiple myeloma].

A 69-year-old male presented with fever, ascites and leg edema in February, 1994. He had a pathological fracture of cervical supine in October. Pathological findings at operation showed plasmacytoma. Bone marrow aspiration showed 16.2% myeloma cells. So he was diagnosed as multiple myeloma presenting biclonal gammopathy of IgA-L and IgD-K. Ascites was massive and drainage of 2 to 4 liter per week was required. Ascites was supposed to be related to multiple myeloma, because the IL-6 level in the ascites was increased (2,440 pg/ml), although repeated cytologic studies were negative. After the operation, he developed hyperammonemic drowsiness. It was also suggested that hyperammonemia was associated with multiple myeloma. In addition to radiation therapy for the cervical lesion, MP therapy, Interferon-alpha, VAD therapy and intraperitoneal cyclophosphamide infusion were administered. But no improvement of ascites or hyperammonemia were noticed. Here we described a case of multiple myeloma with very notable clinical features.

Aged↗

PubMed1996

Amino acid and DNA analyses in a family with ornithine transcarbamylase deficiency.

Ornithine transcarbamylase (OTC) is a hepatic mitochondrial enzyme involved in the detoxification of ammonia by the urea cycle. OTC deficiency is an X-linked genetic disorder, usually causing neonatal or infantile hyperammonemia, coma and death. We attended a male newborn who had poor feeding since 30 hours of age, at which time, he then rapidly progressed to a comatose state. Hyperammonemia and liver dysfunction were noted. Analysis of plasma amino acids showed elevated levels of glutamine and alanine, but a decreased level of arginine and no citrulline. OTC deficiency was diagnosed by family history of early death of newborn males on the maternal side and characteristic biochemical findings. In addition, it was proved by Southern blot analysis of genomic DNA. Although OTC deficiency has been described as the most common inborn error of ureagenesis in humans, to our knowledge, this is the first report in a Chinese family confirmed by biochemical and DNA analyses.

Amino Acid Metabolism, Inborn Errors↗