bluuebunny/crossref_metadata_2025 huggingface dataset:
The human arginases and arginase deficiency
Authors: Iyer R. , Jenkinson C. P. , Vockley J. G. , Kern R. M. , Grody W. W. , Cederbaum S.
Published: December 2002

Arginase is the final enzyme in the urea cycle. Its deficiency is the least frequently described disorder of this cycle. It results primarily in elevated blood arginine, and less frequently in either persistent or acute elevations in blood ammonia. This appears to be due to a second arginase locus, expressed primarily in the kidney, which can be recruited to compensate, in part, for the deficiency of liver arginase. The liver arginase gene structure permitted study of the molecular pathology of patients with the disorder and the results of these studies and the inferences about the protein structure are presented. The conserved regions among all arginases allowed the cloning of AII, the second arginase isoform. It has been localized to the mitochondrion and is thought to be involved in ornithine biosynthesis. It shares the major conserved protein sequences, and structural features of liver arginase gene are also conserved. When AI and AII from various species are compared, it appears that the two diverged some time prior to the evolution of amphibians. The evidence for the role of AII in nitric oxide and polyamine metabolism is presented and this appears consonant with the data on the tissue distribution.
Continuous venovenous haemodiafiltration in the acute phase of neonatal maple syrup urine disease
Authors: Jouvet P. , Poggi F. , Rabier D. , Michel J. L. , Hubert P. , Sposito M. , Saudubray J. M. , Man N. K.
Published: December 2002

Maple syrup urine disease results in accumulation of leucine and its metabolites, which may lead in the long term to neurological dysfunction. In acute neonatal crises, large amounts of leucine may be removed by continuous venovenous haemofiltration. This extracorporeal technique has its risks and hazards, which increase with duration of treatment. We report three neonates in life‐threatening conditions due to maple syrup urine disease, treated for not more than 12h with various continuous venovenous techniques: continuous haemofiltration, haemodiafiltration and haemodialysis. The efficiency of and tolerance to these techniques was evaluated. For all three patients, plasma leucine levels decreased dramatically from 2186, 3818 and 2536 µmol/L to 1131, 1275 and 488 µmol/L, respectively. Leucine clearance obtained was 4.28 ml/min in haemodiafiltration. Their patients' neurological status improved rapidly and they have a normal developmental quotient at 22 months, 13 months, and 11 months of age, respectively. Tolerance was good except for hypothermia and drop in haematocrit in all cases. Haemodiafiltration management was more cumbersome and time consuming because it required continual adjustment of the substitution fluid flow rate to precisely balance inflow and outflow rates. We recommend continuous venovenous haemodialysis as the therapy of choice. It might be anticipated that improvement of this technique, by increasing dialysate flow rate and blood flow rate, will allow leucine concentration to be decreased below 1000 µmol/L within 6‐8 h, whatever the initial level.
A new peroxisomal β‐oxidation disorder in twin neonates: Defective oxidation of both cerotic and pristanic acids
Authors: Christensen E. , Pedersen S. Anker , Leth H. , Jakobs C. , Schutgens R. B. H. , Wanders R. J. A.
Published: December 2002

Twin brothers were born with clinical symptoms indicating that they were suffering from Zellweger syndrome. However, instead of a generalized peroxisomal dysfunction, only very long‐chain fatty acids and the pristanic acid/phytanic acid ratio were elevated in plasma and decreased oxidation of very long‐chain fatty acids and pristanic acid was the only impairment found in fibroblasts. The other peroxisomal parameters tested were normal, including normal oxidation of phytanic acid and normal activity of dihydroxyacetonephosphate acyltransferase in fibroblasts as well as normal plasma bile acids. Although the biochemical results point to a defect in peroxisomal β‐oxidation, the isolated finding of impaired oxidation of very long‐chain fatty acids and pristanic acid has to our knowledge not been reported previously and is difficult to explain by a deficiency of a known peroxisomal β‐oxidation enzyme.
Plasmalogens and oxidative stress: evidence against a major role of plasmalogens in protection against the superoxide anion radical
Authors: Jansen G. A. , Wanders R. J. A.
Published: December 2002

Although ether‐linked phospholipids have been known to be constituents of biological membranes for a long time, their physiological function has remained an enigma through the years. Inspired by the suggestion of Zoeller and coworkers that plasmalogens, which are specific types of ether‐linked phospholipids characterized by the occurrence of an α,β‐unsaturated ether bond at the sn‐1 position, are involved in the protection of cells against reactive oxygen species, we studied reactive oxygen species metabolism in cultured human skin fibroblasts. Menadione was used as intracellular generator of reactive oxygen species and cytochrome c as extracellular indicator for the production of reactive oxygen species. The finding that identical results were obtained in control and plasmalogen‐deficient fibroblasts leads us to conclude that plasmalogens do not play a major role in protection against reactive oxygen species.
5α‐Reductase deficiency in patients with micropenis
Authors: Gad Y. Z. , Nasr H. , Mazen I. , Salah N. , El‐Ridi R.
Published: December 2002

The enzyme 5α‐reductase (5αR), by virtue of its peripheral 5α‐reduction of testosterone (T) to dihydrotestosterone (DHT), is believed to play a major role in the differentiation and the subsequent growth of the penis. However, recent studies have reported 5αR deficiency (5αRD) in patients with isolated micropenis and hypothesized that 5αRD is not invariably associated with genital ambiguity. In Egypt, 5αRD has been reported frequently among intersex patients. The aim of this study was to assess the role of 5αRD in the development of micropenis among Egyptian patients with abnormal sexual development. The study included 29 patients who were categorized into three groups (isolated micropenis, 9 patients; microphallus with genital ambiguity, 11 patients; genital ambiguity with normal‐sized phallus, 9 patients). Activity of 5αR was assessed by estimating T/DHT ratios in the basal state in pubertal subjects and following human chorionic gonadotropin (HCG) stimulation test in prepubertals.

The results showed that the incidence of 5αRD was much higher in cases of ambiguous genitalia with micropenis (5 families out of 10, 50%) than in those with isolated microphallus (1/9, 11·1%) or those with ambiguous genitalia and normal‐sized phallus (1/8, 12.5%). In conclusion, the study showed that isolated micropenis is a heterogeneous disorder and that 5αRD, despite its relative prevalence in Egypt, has a minimal role in the aetiology. On the other hand, 5αRD seems to correlate with penile length in intersex cases.
Executive function in treated phenylketonuria as measured by the one‐back and two‐back versions of the continuous performance test
Authors: Griffiths P. , Campbell R. , Robinson P.
Published: December 2002

The executive dysfunction hypothesis in treated phenylketonuria was investigated by means of the one‐back and two‐back versions of the continuous performance test. Eleven non‐retarded, primary school‐age children with classical phenylketonuria who had been treated early and continuously were indistinguishable from healthy, matched controls on the measures and test performance was not predicted by historical or concurrent plasma phenylalanine concentrations. Mean lifetime phenylalanine concentrations for the phenylketonuric subjects were within ranges currently recommended as dietary optima in the United Kingdom. The negative neuropsychological test findings add weight to the rationale for this policy.
Two new mutations in the 3′ coding region of the glycogen debranching enzyme in a glycogen storage disease type IIIa Ashkenazi Jewish patient
Authors: Parvari R. , Shen J. , Hershkovitz E. , Chen Y. T. , Moses S. W.
Published: December 2002

Glycogen storage disease type III (GSD III) is an autosomal recessive disease caused by the deficiency of glycogen debranching enzyme (AGL). We report the finding of two new mutations in a GSD IIIa Ashkenazi Jewish patient. Both mutations are insertion of an adenine into a stretch of 8 adenines towards the 3′ end of the coding region: one at position 3904 (3904insA) in exon 30, the second at position 4214 (4214insA) in exon 32. The mutations cause frameshifts and premature terminations of the glycogen debranching enzyme, the first causing a frameshift at amino acid 1304, the second causing a frameshift at amino acid 1408 of the total of 1532. These mutations demonstrate the importance of the 125 amino acids at the carboxy‐terminus of the debrancher enzyme for its activity and support the suggestion that the putative glycogen binding domain is located in the carboxy‐terminus of the AGL. The mutations cause distinctive single‐strand conformation polymorphism (SSCP) patterns enabling easy detection.
Subclinical visual impairment in phenylketonuria. A neurophysiological study (VEP‐P) with clinical, biochemical, and neuroradiological (MRI) correlations
Authors: Leuzzi V. , Rinalduzzi S. , Chiarotti F. , Garzia P. , Trasimeni G. , Accornero N.
Published: December 2002

During detailed visual function testing, pattern‐reversal visual evoked potentials (VEP), generated by different spatial frequencies (3c/d, 1c/d and 0.6c/d) and visual contrasts (100% and 10%) were recorded in 21 adolescent and young adult phenylketonuric (PKU) patients (11 females and 10 males; mean age 14.8 years, range 9–22.8) on and off diet. In 14 of the 21 patients, disease had been detected at neonatal screening and in 7 later. Ten age‐matched healthy subjects acted as controls. Recordings in more than 40% of eyes in the whole group and 30% of eyes in the screening subgroup showed a prolonged P100 latency. All visual pattern stimuli elicited a significantly longer P100 latency in PKU patients than in controls. VEP latencies to 3c/d, 1c/d and 1c/d with 10% contrast – but not to 0.6c/d – were longer in patients off diet than in patients on diet. No differences were found between VEP latencies in early‐ and later‐detected subjects. To study the link between biochemical variables and VEP latencies, we envisaged either a linear relationship between recent exposure to phenylalanine (Phe) and VEP abnormalities or a threshold model considering phenylalanine (Phe) concentrations among the factors influencing VEP latencies. The correlation analysis detected an association between plasma Phe concentrations and abnormal VEP latencies, predicting that plasma Phe concentrations >901 μmol/L would prolong VEP latencies to 1c/d; concentrations >879 μmol/L would prolong latencies to 3c/d; and concentrations >898 μmol/L would prolong latencies to 1c/d with 10% contrast. Finally, our data confirmed a lack of correlation between white‐matter abnormalities on MRI and abnormal VEP latencies. Our findings suggest that in young patients with PKU, prolonged, late exposure to high plasma Phe concentrations induces subclinical visual dysfunction. Although our findings do not allow us to specify the origin of visual system changes in PKU, they favour impairment of the retinal loop as the responsible mechanism.
The recognition of Lesch‐Nyhan syndrome as an inborn error of purine metabolism
Authors: Nyhan W. L.
Published: December 2002

Lesch‐Nyhan syndrome was first described over thirty years ago. The original patient was a 4‐year‐old boy with neurological abnormalities as well as haematuria. Crystals in his urine were identified and confirmed to be uric acid. The massive excretion of this purine led to metabolic studies using isotopically labelled uric acid to study turnover rates. Clues to the site of the enzyme defect resulted from studies with the immunosuppressive agent azathioprine, which normally causes uric acid concentrations to fall in blood and urine but was without effect in a Lesch‐Nyhan patient. A deficiency of hypoxanthine phosphoribosyltransferase (HPRT) activity explained this observation in Lesch‐Nyhan patients. Subsequent studies have indicated that the degree of HPRT deficiency appears to determine the severity of the disease. Molecular studies have shown that most families carry a unique mutation. Attempts are being made to correlate the type and site of a specific mutation with a particular phenotype.
Highly increased CSF concentrations of cholesterol precursors in Smith‐Lemli‐Opitz syndrome
Authors: van Rooij A. , Nijenhuis A. A. , Wijburg F. A. , Schutgens R. B. H.
Published: December 2002

The Smith‐Lemli‐Opitz syndrome is a genetic disorder characterized by typical clinical features including reduced myelination of both brain and peripheral nervous system and defective cholesterol biosynthesis. In patients this results in very low cholesterol concentrations and accumulation of cholesterol precursors in plasma, tissues, cultured cells and faeces. We now show that the cholesterol concentration in CSF of Smith‐Lemli‐Opitz patients is markedly decreased and that 7‐ and 8‐dehydrocholesterol concentrations are highly increased in comparison to controls. Moreover, dietary treatment of patients with cholesterol seems not to affect CSF cholesterol concentration.
Neonatal neurological assessment of offspring in maternal phenylketonuria
Authors: Waisbren S.E. , Chang P. , Levy H. L. , Shifrin H. , Allred E. , Azen C. , de la Cruz F. , Hanley W. , Koch R. , Matalon R. , Rouse B.
Published: December 2002

This study assesses the impact of prenatal and postnatal factors in maternal phenylketonuria (PKU). The Dubowitz Neurological Assessment of the Preterm and Full‐term Newborn Infant was administered within the first 8 days of life to 56 offspring of women with PKU and 45 controls. Follow‐up testing of the maternal PKU offspring at age 1 year consisted of the Bayley Scales of Infant Development and the Receptive‐Expressive Emergent Language Scale (REEL). In addition, the Home Observation for Measurement of the Environment (HOME Scale) was given. Birth weight was lower (z = 2.0, p = 0.045), birth length was lower (z = 2.1, p = 0.03) and birth head circumference was smaller (z = 3.5, p = 0.0005) in the maternal PKU offspring than in the control infants. Examiners rated 29% of the maternal PKU offspring and 9% of the control infants abnormal (Fisher's exact test, p = 0.01). At 1 year of age, 19% of the maternal PKU offspring attained a Bayley Developmental Quotient (DQ) and a score on the Bayley Motor Scale below 85; 19% had receptive language delay; and 26% had expressive language delay. The gestational age at which the mother attained metabolic control was an important factor associated with birth measurements, the Dubowitz Rating and subsequent developmental scores. The Dubowitz Neurological Assessment score did not predict developmental outcome (chi‐square = 1.3, p = 0.53), while the HOME score correlated with the DQ (r = 0.36, p = 0.02). In logistic regression analyses, the home environment was a greater determinant of risk for a low DQ than whether or not the mother attained metabolic control prior to prenancy (OR = 0.85, p = 0.02). These suggewst that treatment strategies addressing both prenatal and postnatal factors will most effectively reduce risks in maternal PKU.
Inherited defects of purine and pyrimidine metabolism: Laboratory methods for diagnosis
Authors: Duran M. , Dorland L. , Meuleman E. E. E. , Allers P. , Berger R.
Published: December 2002

The diagnosis of the majority of the known inherited defects of purine and pyrimidine metabolism can be achieved by analysing urinary excretion profiles. A quantitative measurement of the urinary uric acid/creatinine ratio should be the first approach for purine defects. The general screening system involves separation of the bases and nucleosides by reversed‐phase high‐performance liquid chromatography and multiwavelength UV detection. The catabolic defects of pyrimidine degradation can be diagnosed by gas chromatography ‐ mass spectrometry as used for organic acids. For the detection of adenylosuccinase deficiency, several simple but effective thin‐layer chromatographic methods are available.

Techniques such as liquid chromatography ‐ mass spectrometry, direct nega‐tive‐ion fast‐atom bombardment mass spectrometry, and proton nuclear magnetic resonance spectroscopy give promising results, but are not yet being used on a large scale. Patients should keep to a simple diet and preferably be free of medication in order to allow a reliable interpretation of the analytical data.
Accumulation of sphingolipid activator proteins (SAPs) A and D in granular osmiophilic deposits in miniature Schnauzer dogs with ceroid‐lipofuscinosis
Authors: Palmer D. N. , Tyynelä J. , van Mil H. C. , Westlake V. J. , Jolly R. D.
Published: December 2002

The neuronal ceroid‐lipofuscinoses (NCL, Batten disease) are fatal inherited neurodegenerative diseases of children characterized by retinal and brain atrophy and the accumulation of electron‐dense storage bodies in cells. Mutations in different genes underlie different major forms. The infantile disease (CLN‐1, McKusick 256730) is distinguished by the storage of the sphingolipid activator proteins (SAPs) A and D in distinctive granular osmiophilic deposits (GRODs). This contrasts with the other major forms, where subunit c of mitochondrial ATP synthase is stored in various multilamellar profiles. Ceroid‐lipofuscinoses also occur in dogs, including a form in miniature Schnauzers with distinctive granular osmiophilic deposit‐like storage bodies. Antisera to SAPs A and D reacted to these storage bodies in situ. The presence of SAP D was confirmed by Western blotting and of SAP A by protein sequencing. Neither subunit c of mitochondrial ATP synthase nor of vacuolar ATPase is stored. This suggests that there are two families of ceroid‐lipofuscinoses, the subunit c‐storing forms, and those in which SAPs A and D, and perhaps other proteins, accumulate. Further work is required to determine whether other forms with granular osmiophilic deposits belong to the latter class and the genetic relationships between them and the human infantile disease.
Neurodevelopmental outcome of long‐term therapy of urea cycle disorders in Japan
Authors: Uchino T. , Endo F. , Matsuda I.
Published: December 2002

In Japan, urea cycle disorders (UCDs) are one of the most frequent inborn errors of metabolism, estimated to have a prevalence of 1 per 50 000 live births. In an attempt to develop more effective treatment and enhance the quality of life, we investigated the clinical manifestations and prognosis of 216 patients with UCDs diagnosed and treated between 1978 and 1995. These included 92 cases of neonatal‐onset UCD and 116 of late‐onset UCD. Two cases of ornithine transcarbamylase (OTC) deficiency in males and 2 cases of argininosuccinase (AL) deficiency were diagnosed prospectively. By far the most common disorder was OTC deficiency, accounting for 2/3 of all cases. At the end of 1995, the 5‐year survival rate was 22% for the neonatal‐onset type and 41% for the late‐onset type. Among the 20 long‐term survivors with neonatal‐onset UCD, 18 (90%) had moderate to severe neurodevelopmental deficits; this contrasts with 13 of 47 (28%) survivors with the late‐onset type. In analysing 108 UCD cases, peak blood ammonia level during the first hyperammonaemic attack was correlated with neurodevelopmental outcome. When the concentration of blood ammonia was less than 180 µmol/L (5 times normal), there was no severe neurological damage. When the concentration of blood ammonia exceeded 350 µmol/L (10 times normal) at the first hyperammonaemic attack, the patients died or had severe neurological deficits. Our data point to the importance of early diagnosis and aggressive treatment.
Does the polymorphism 677C‐T of the 5,10‐methylenetetrahydrofolate reductase gene contribute to homocysteine‐related vascular disease?
Authors: Thuillier L. , Chadefaux‐Vekemans B. , Bonnefont J. P. , Kara A. , Aupetit J. , Rochette C. , Montalescot G. , Couty M. C. , Kamoun P. , Ankri A.
Published: December 2002

Whether the 677C‐T polymorphism of the methylene tetrahydrofolate reductase (MTHFR) gene acts as a risk factor for homocysteine‐related vascular disease remains a matter of debate. Testing for the 677C‐T nucleotide substitution and assay of plasma homocysteine were carried out simultaneously in 69 controls and 113 vascular disease patients from the Paris area. The variant gene frequency as well as the variant homozygous genotype frequency were very similar in controls and patients. Conversely, plasma homocysteine levels were substantially higher in patients than in controls. A slight interaction between the 677C‐T MTHFR polymorphism and homocysteinaemia was observed in the patient group only, while a negative correlation between fasting homocysteine and plasma folate levels was found in all individuals homozygous for the 677C‐T MTHFR genotype, irrespective of vascular disease. These data suggest that the 677C‐T MTHFR polymorphism is not a major determinant of the vascular disease but contributes to increased plasma homocysteine concentration in conjunction with low plasma folate levels.
Mutational analyses in four Japanese families with X‐linked liver phosphorylase kinase deficiency type 1
Authors: Hirono H. , Shoji Y. , Takahashi T. , Sato W. , Takeda E. , Nishijo T. , Kuroda Y. , Nishigaki T. , Inui K. , Takada G.
Published: December 2002

We analysed the gene of the human α‐subunit of liver phosphorylase kinase (PHKA2) in four Japanese families with X‐linked liver phosphorylase kinase deficiency type 1 by RT‐PCR followed by PCR–single‐strand conformation polymorphism and direct DNA sequencing. In this study, two novel mutations (Y116D and 2675A→G) and one mutation previously reported (P1205L) were identified, revealing molecular heterogeneity in Japanese patients. Considering the dissimilarity in phenotype among our patients even with an identical mutation in the PHKA2 gene, it seems that each genetic deficiency in this gene may not be the only factor to determine the clinical heterogeneity in this disease.
Biochemical monitoring of the treatment in paediatric patients with mitochondrial disease
Authors: Artuch R. , Vilaseca M. A. , Pineda M.
Published: December 2002

Treatment strategies in mitochondrial diseases consist of several drugs that diminish the deleterious effects of the abnormal respiratory chain function, reduce the presence of toxic agents or correct deficiencies in essential cofactors. In this study we evaluated the monitoring of tocopherol, carnitine and ubiquinone concentrations in a group of paediatric patients during a follow‐up period of 18 months and the response to treatment of these patients by means of the determination of blood lactate, plasma alanine and oxygen consumption by lymphocytes in relation to the clinical status of the patients. Tocopherol, carnitine and ubiquinone concentrations were easily corrected with therapy. Blood lactate proved the best biochemical tool to assess the response to treatment in paediatric patients. According to our results, improvement or stabilization of the clinical course seems to be more related to the biochemical or molecular defect than to the effectiveness of the treatment.
4‐Aminobutyrate aminotransferase (GABA‐transaminase) deficiency
Authors: Medina‐Kauwe L. K. , Tobin A. J. , De Meirleir L. , Jaeken J. , Jakobs C. , Nyhan W. L. , Gibson K. M.
Published: December 2002

4‐Aminobutyrate aminotransferase (GABA‐transaminase, GABA‐T, EC 2.6.1.19) deficiency (McKusick 137150), an inborn error of GABA degradation, has until now been documented in only a single Flemish child. Compared to the other defects of GABA degradation, succinic semialdehyde dehydrogenase (SSADH, EC 1.2.1.24) deficiency with >150 patients (McKusick 271980) and pyridoxine‐dependent seizures with >100 patients ('putative'glutamic acid decarboxylase (GAD, EC 4.1.1.15) deficiency; McKusick 266100), GABA‐T deficiency is very rare. We present a summary of the clinical, biochemical, enzymatic and molecular findings on the index proband, and a recently identified second patient, with GABA‐T deficiency. The phenotype in both included psychomotor retardation, hypotonia, hyperreflexia, lethargy, refractory seizures and electroencephalographic abnormalities. In an effort to elucidate the molecular basis of GABA‐T deficiency, we isolated and characterized a 1.5kb cDNA encoding human GABA‐T, in addition to a 41kb genomic clone which encompassed the GABA‐T coding region. Standard methods of cloning and sequencing revealed an A‐to‐G transition at nucleotide 754 of the coding region in lymphoblast cDNAs derived from the index proband. This mutation resulted in substitution of an invariant arginine at amino acid 220 by lysine. Expression of the mutant in E. coli, followed by isolation and enzymatic characterization of the recombinant protein, revealed an enzyme whose Vmax was reduced to 25% of wild‐type activity. The patient and father were heterozygous for this allele; the second allele in the patient remains unidentified. Genomic Southern analysis revealed that the second proband most likely harbours a deletion in the 3′region of the GABA‐T gene.
Spinal muscular atrophy
Authors: Talbot K.
Published: December 2002

Spinal muscular atrophy is a common cause of disability in childhood and is characterized by weakness and wasting of voluntary muscle. It is frequently fatal. The gene for this disorder has been identified as the SMN gene and is part of a highly complex duplicated region of chromosome 5 that is subject to a high rate of gene deletion and gene conversion. The severity of muscle weakness correlates with the amount of full‐length SMN protein produced. Molecular genetic studies support a model in which patients are compound heterozygotes of deleted and converted alleles that predicts a progressively decreasing amount of protein product with severity of muscle weakness. The function of SMN is beginning to be understood and it appears to be involved in ribonucleoprotein biogenesis and thus indirectly in post‐transcriptional processing of mRNA. There are theoretical grounds for motor neurons having a cell‐specific vulnerability to disturbances of mRNA processing and transport and these are briefly reviewed.
Chloramphenicol and Ampicillin-Induced Changes in Rat Hepatic Esterase and Amidase Activities
Authors: Farombi E. Olatunde , Nwankwo Joseph O. , Wara Sanusi H. , Odutola Bankole , Emerole Godwin O.
Published: December 2002

The influence of ampicillin and chloramphenicol administered intraperitoneallysingly or in combination on the protein content and the activities of hepaticsterase and amidase have been investigated in rats. The results have beencompared to the effects of phenobarbitone (inducer) andp-nitrophenyl-phosphate (inhibitor) of hepatic hydrolases.

Ampicillin pretreatment reduced protein level and amidase activity by3.5% each but caused a significant increase (8.1%) in total esteraseactivity compared to controls. Chloramphenicol treatment caused an overalldecrease in protein level, esterase and amidase activities respectively by11%, 11%, and 35% over controls.

Combined administration of both drugs resulted in a decrease in protein,esterase and amidase activities by 11.5%, 12.5%, and 41.2% respectively,thus mimicking the effects obtained with chloramphenicol alone.

The changes induced by administration of the drugs particularly incombination on the constituent enzymes of rat hepatic hydrolases may affectthe ability of the body to deal with exposure to environmental chemicals ifextrapolated to man.
Intracellular Free Calcium Concentration and Cisplatin Resistance in Human Lung Adenocarcinoma A549 Cells
Authors: Liang Xingjie , Huang Youguo
Published: December 2002

Human lung adenocarcinoma A549 cells sensitive and A549/DDP cells resistantto Cis-dichlorodiammine platinum[II] (cisplatin) exhibit differentintracellular free calcium and calcium fluorescence images labeled withFura-2/AM and Fluo-3/AM as judged by dual-excitation fluorescence assay,Miracal Imaging and Laser Scanning Confocal Microscopy (LSCM) of singlecells. The concentration of intracellular free calcium of the resistantA549/DDP cells is one third that of the sensitive A549 cells. The effluxof Rhodamine 123 in resistant A549/DDP cells is faster than that insensitive A549 cells. In addition, A549/DDP cells have an increase ofPhosphatidylinositol 4-kinase (PtdIns 4-kinase) activity in the plasmamembrane. So it is tentatively suggested that the increase in PtIns4-kinase activity resulting from lower intracellular Ca2+concentration leads to an increase of its enzymaticproducts”�”�PIP and PIP2, which may stimulate the activity ofP-glycoprotein.
Long‐term outcome of liver transplantation in patients with glycogen storage disease type Ia
Authors: Faivre L. , Houssin D. , Valayer J. , Brouard J. , Hadchouel M. , Bernard O.
Published: December 2002

Liver transplantation may be indicated in patients with GSD type Ia when dietary treatment fails or when hepatic adenomas develop, because they carry a risk of liver cancer or severe intratumoral haemorrhage. Published reports on the results of liver transplantation in patients with GSD Ia include 10 patients and provide little information on long‐term outcome. In particular, it is not known whether liver transplantation prevents renal failure due to focal segmental glomerulosclerosis. We report here on 3 patients with GSD Ia in whom liver transplantation was performed at 15, 17 and 23 years of age because of multiple hepatic adenomas in all 3 patients with a fear of malignant transformation, and of poor metabolic balance and severe growth retardationin the youngest one. Renal function was normal in all patients. During the 6–8 years following transplantation, the quality of life has initially greatly improved, with none of the previous dietary restraints and a spectacular increase in height. However, long‐term complications included chronic hepatitis C in one patient, gouty attacks in another and focal segmental glomerulosclerosis with progressive renal insufficiency in the third. These results: (1) confirm that liver transplantation restores a normal metabolic balance in patients with GSD Ia, allows catch‐up growth and improves the quality of life; (2) suggest that liver transplantation may be considered in teenagers with unresectable multiple adenomas because of a lack of clear‐cut criteria to detect malignant transformation early; and (3) suggest that liver transplantation does not prevent focal segmental glomerulosclerosis associated with GSD Ia.
Recognition and management of fatty acid oxidation defects: A series of 107 patients
Authors: Saudubray J. M. , Martin D. , De Lonlay P. , Touati G. , Poggi‐Travert F. , Bonnet D. , Jouvet P. , Boutron M. , Slama A. , Vianey‐Saban C. , Bonnefont J. P. , Rabier D. , Kamoun P. , Brivet M.
Published: December 2002

In a personal series of 107 patients, we describe clinical presentations, methods of recognition and therapeutic management of inherited fatty acid oxidation (FAO) defects. As a whole, FAO disorders appear very severe: among the 107 patients, only 57 are still living. Including 47 siblings who died early in infancy, in total 97 patients died, of whom 30% died within the first week of life and 69% before 1 year. Twenty‐eight patients presented in the neonatal period with sudden death, heart beat disorders, or neurological distress with various metabolic disturbances. Hepatic presentations were observed in 73% of patients (steatosis, hypoketotic hypoglycaemia, hepatomegaly, Reye syndrome). True hepatic failure was rare (10%); cholestasis was observed in one patient with LCHAD deficiency. Cardiac presentations were observed in 51% of patients: 67% patients presented with cardiomyopathy, mostly hypertrophic, and 47% of patients had heart beat disorders with various conduction abnormalities and arrhythmias responsible for collapse, near‐miss and sudden unexpected death. All enzymatic blocks affecting FAO except CPT I and MCAD were found associated with cardiac signs. Muscular signs were observed in 51% of patients (of whom 64% had myalgias or paroxysmal myoglobinuria, and 29% had progressive proximal myopathy). Chronic neurologic presentation was rare, except in LCHAD deficiency (retinitis pigmentosa and peripheral neuropathy). Renal presentation (tubulopathy) and transient renal failure were observed in 27% of patients. The diagnosis of FAO disorders is generally based on the plasma acylcarnitine profile determined by FAB‐MS/MS from simple blood spots collected on a Guthrie card. Urinary organic acid profile and total and free plasma carnitine can also be very helpful, mostly in acute attacks. If there is no significant disturbance between attacks, the diagnosis is based upon a long‐chain fatty acid loading test, fasting test, and in vitro studies of fatty acid oxidation on fresh lymphocytes or cultured fibroblasts. Treatment includes avoiding fasting or catabolism, suppressing lipolysis, and carnitine supplementation. The long‐term dietary therapy aims to prevent periods of fasting and restrict long‐chain fatty acid intake with supplementation of medium‐chain triglycerides. Despite these therapeutic measures, the long‐term prognosis remains uncertain.
Sendai Virus Binds to a Dispersed Population of NBD-GD1a
Authors: Rocheleau Jonathan V. , Petersen Nils O.
Published: December 2002

Receptor aggregation is believed to be an important step in the attachmentof membrane enveloped virus' to target cell membranes. A likely receptorfor Sendai virus is the ganglioside GD1a. In this work we have studied themembrane diffusion of the fluorescent ganglioside NBD-GD1a on the surfaceof CV-1 cells with standard photobleaching techniques. Using confocallaser scanning microscopy (CLSM) and Image Correlation Spectroscopy(ICS) NBD-GD1a is shown to exist in at least two populations: dispersedand aggregated. By quantifying the distribution of NBD-GD1a pre- andpost-incubation with Sendai virus it is shown that the virus inducesa dose-dependent clustering of NBD-GD1a. Image cross-correlationspectroscopy (ICCS) is used to further quantitatively characterizethis clustering by demonstrating that it occurs due to binding ofvirus to the dispersed population of NBD-GD1a.
Culture and Function of Electrofusion-Derived Clonal Insulin-Secreting Cells Immobilized on Solid and Macroporous Microcarrier Beads
Authors: Hamid M. , McCluskey J. T. , McClenaghan N. H. , Flatt P. R.
Published: December 2002

In view of the advantages of the bulk production of clonal pancreaticbeta cells, an investigation was made of the growth and insulin secretoryfunctions of an electrofusion-derived cell line (BRIN-BD11) immobilizedon a solid microcarrier, cytodex-1 or a macroporous microcarrier,cultispher-G. For comparison, similar tests were performed usingBRIN-BD11 cells present in single cell suspensions or allowed toform pseudoislets. Similar growth profiles were recorded for eachmicrocarrier with densities of 4.4×105±0.3 cells/ml and4.2×105±0.2 cells/ml achieved using cytodex-1 andcultispher-G, respectively. Cell viability began to decline on day 5 ofculture. Insulin concentration in the culture medium reached a peak of26±2.0 ng/ml and 24±2.2 ng/ml for cells grown oncytodex-1 and cultispher-G, respectively. Cells grown on both types ofmicrocarrier showed a significant 1.5–1.8-fold acuteinsulin-secretory response to 16.7 mmol/l glucose. L-alanine (10 mmol/l) andL-arginine (10 mmol/l) also induced significant 3–4 fold increasesof insulin release. BRIN-BD11 cells immobilized on cytodex-1 or cultispher-Gout-performed single cell suspensions and pseudoislets in terms ofinsulin-secretory responses to glucose and amino acids. A 1.3-fold,2.2-fold and 1.7-fold stimulation of insulin secretion was observed forglucose, L-alanine and L-arginine respectively in single cellsuspensions. Corresponding increases for pseudoislets were1.6–1.8-fold for L-alanine and L-arginine, with no significantresponse to glucose alone. These data indicate the utility ofmicro-carriers for the production of functioning clonal beta cells.
The neuronal ceroid‐lipofuscinoses (Batten disease): A new class of lysosomal storage diseases
Authors: Bennett M. J. , Hofmann S. L.
Published: December 2002

The neuronal ceroid‐lipofuscinoses (Batten disease) are a group of severe neurodegenerative disorders characterized clinically by visual loss, seizures and psychomotor degeneration, and pathologically by loss of neurons and lysosomal accumulation of autofluorescent storage material resembling ageing pigment. To date, eight genetic loci have been identified (CLN1‐8). Four CLN genes have been isolated (CLN1, CLN2, CLN3 and CLN5) and their gene products have been characterized. CLN1 is a lysosomal palmitoyl‐protein thioesterase (PPT) and CLN2 is a lysosomal pepstatin‐insensitive peptidase. CLN3 and CLN5 are proteins with multiple membrane‐spanning regions and have no homologies to other proteins that would suggest their function. The CLN3 protein is associated with lysosomal membranes and the intracellular location of the CLN5 protein is unknown. Therefore, there is ample evidence that the neuronal ceroid‐lipofuscinoses represent a new class of lysosomal storage disorders.
A rapid screening procedure for the diagnosis of peroxisomal disorders: Quantification of very long‐chain fatty acids, as dimethylaminoethyl esters, in plasma and blood spots, by electrospray tandem mass spectrometry
Authors: Johnson D. W.
Published: December 2002

A rapid method with potential to screen for many of the peroxisomal disorders using 5μl of plasma or a 3‐mm blood spot (3.6μl blood impregnated on filter paper) is described. Fatty acids are liberated from plasma or blood spots and converted to dimethylaminoethyl esters. Trideuterated fatty acids, added as internal standards, are used to quantify eicosanoic (C20:0), docosanoic (C22:0), tetracosanoic (C24:0) and hexacosanoic (C26:0) acids by electrospray tandem mass spectrometry. The C26:0/C22:0 and C24:0/C22:0 ratios are significantly greater in the plasma of patients with peroxisomal disorders compared to controls. The C20:0/C22:0 ratio is elevated in the plasma of peroxisomal patients who accumulate phytanic acid. Blood spots collected from four peroxisomal patients between 2 and 10 days after birth and stored for up to 17 years, were shown to give between 33% and 233% higher C26:0/C22:0 ratios compared to age‐matched controls.
Differentiation of hair growth cycle from scalp hair roots for the diagnosis of glucose‐6‐phosphate dehydrogenase deficiency in neonates
Authors: Lin S.‐Y. , Niu D.‐M. , Li M.‐J. , Tu C.‐P. , Lin H.‐L.
Published: December 2002

Hair analysis can be used as a screening tool in the diagnosis of genetic diseases. The scalp hair roots of 67 normal neonates and 39 neonates with glucose‐6‐phosphate dehydrogenase (G6PD) deficiency were analysed using Fourier transform infrared (FT‐IR) microspectroscopy to differentiate the stages of the hair growth cycle and to diagnose the genetic disorder on the basis of spectral differences. We have demonstrated that FT‐IR microspectroscopy is a rapid and effective noninvasive diagnostic method to differentiate scalp hair roots of normal neonates into the anagen, catagen or telogen phases of the hair growth cycle, using IR spectral differences within the 3000–2800 cm−1 region and the IR peak area ratio of 2854 cm−1/2873 cm−1 or 1084 cm−1/amide II band (p<0.001). Moreover, G6PD‐deficient neonates could be accurately diagnosed from telogen phase hair roots owing to significant differences in IR peak area ratios of 2854 cm−1/2873 −1 or 1084 cm−1/amide II band compared to normal values in healthy neonates. The result suggests that the application of FT‐IR microspectroscopy may be capable not only of differentiating the hair growth cycle into anagen, categen or telogen phases but also of detecting G6PD deficiency. Hair root analysis promises to be a useful complement to serum and urine analysis in the diagnosis of genetic diseases.
Sequence variations in the NDUFA1 gene encoding a subunit of complex I of the respiratory chain
Authors: Wittig I. , Augstein P. , Brown G. K. , Fujii T. , Rötig A. , Rustin P. , Munnich A. , Seibel P. , Thorburn D. , Wissinger B. , Tamboom K. , Metspalu A. , Lamantea E. , Zeviani M. , Wehnert M. S.
Published: December 2002

NDUFA1 is one of the 36 nuclear genes encoding subunits of the mitochondrial complex I involved in the respiratory chain. The human NDUFA1 has been cloned, completely sequenced and mapped to Xq24. In the present study, we searched for sequence variations in NDUFA1 as causative defects in complex I deficiency using genomic DNA of 152 patients with various clinical phenotypes. The patient sample consisted of 54 patients (46 male and 8 female) with Leber heriditary optic neuropathy (LHON) from 48 unrelated families from Germany and 98 patients (72 male and 26 female) with biochemically proven complex I deficiency including Leigh syndrome. Patient DNA was used to amplify all three exons, including the exon/intron boundaries and the promoter region of NDUFA1 for heteroduplex analysis and direct sequencing. In the 152 patients tested, no mutation was found that could be related to any of the disease phenotypes included. However, three single‐nucleotide polymorphisms (SNPs) located in the promoter region (SNP G/C at nt −71 and SNP T/C at nt −189) and in intron 1 (SNP T/G nt 1454) were discovered. Allele frequencies of the SNPs were estimated in a German and Estonian control population and compared to complex I‐deficient patients. There was no significant difference between the control population, the LHON patients, or the severely affected patients with complex I deficiency, excluding an association of the polymorphisms with the diseases. Our results suggest that mutations in NDUFA1 do not cause the gender difference observed in clinically severe and complex phenotypes with complex I deficiency.
Dietary therapy in two patients with a mild form of sulphite oxidase deficiency. Evidence for clinical and biological improvement
Authors: Touati G. , Rusthoven E. , Depondt E. , Dorche C. , Duran M. , Heron B. , Rabier D. , Russo M. , Saudubray J. M.
Published: December 2002

We report an attempt at dietetic therapy in two unrelated patients with isolated sulphite oxidase deficiency, with a mild clinical course and late onset of symptoms. In case 1, disease started at 15 months with an acute crisis of agitation, unexplained crying and restlessness following otitis. Case 2 was diagnosed at 10 months when she presented with slight motor delay and dislocation of lenses. In both cases, sulphite oxidase activity measured in fibroblasts was undetectable. Therapy consisted of a diet low in protein from natural foods (daily methionine intake 130–150 mg) and a synthetic amino acid mixture (50 g per day) without cystine and methionine (Xmet, Cys Maxamaid, SHS International Ltd). A comparison of clinical and biochemical parameters was made between the period before treatment and after 2 years of treatment. Restriction in protein and sulphur amino acids brought about a dramatic decrease of urinary thiosulphate and S‐sulphocysteine. It also brought about a generalized hypoaminoacidaemia with a low plasma methionine and cystine in both patients. Furthermore, both patients grew normally with no signs of neurological deterioration, and there was evidence of progress in psychomotor development.
Pharmacological and genetic modifications of somatic cholesterol do not substantially alter the course of CNS disease in Niemann–Pick C mice
Authors: Erickson R. P. , Garver W. S. , Camargo F. , Hossian G. S. , Heidenreich R. A.
Published: December 2002

Niemann–Pick type C (NPC) is a neurodegenerative disorder with somatically altered cholesterol metabolism. The NPC1 gene has recently been cloned and shown to have sequences shared with known sterol‐sensing proteins. We have used a mouse model with a disrupted Npc1 gene to study two cholesterol‐lowering drugs (nifedipine and probucol) and the effects of introducing a null mutation in the low‐density lipoprotein receptor (LDLR). Although these treatments significantly ameliorated liver cholesterol storage, little effect on the onset of neurological symptoms was found.
Three cases of intravenous sodium benzoate and sodium phenylacetate toxicity occurring in the treatment of acute hyperammonaemia
Authors: Praphanproj V. , Boyadjiev S. A. , Waber L. J. , Brusilow S. W. , Geraghty M. T.
Published: December 2002

Intravenous sodium benzoate and sodium phenylacetate have been used successfully in the treatment of acute hyperammonaemia in patients with urea cycle disorders. They provide alternative pathways for waste nitrogen disposal and help maintain nitrogen homeostasis. However, we report three patients with hyperammonaemia who received inappropriate doses of intravenous sodium benzoate and sodium phenylacetate that resulted in severe complications. Ambiguous medical prescriptions and inadequate cross‐checking of drug dosage by physicians, nurses and pharmacists were the main causes of these incidents. All the patients presented with alteration in mental status, Kussmaul respiration and a partially compensated metabolic acidosis with an increased anion gap. Two patients developed cerebral oedema and hypotension and died. The third survived after haemodialysis. Plasma levels of benzoate and phenylacetate were excessively high. The possible mechanisms of toxicity, management and safety measures are discussed.
Reduction of large neutral amino acid concentrations in plasma and CSF of patients with maple syrup urine disease during crises
Authors: Wajner M. , Coelho D. M. , Barschak A. G. , Araújo P. R. , Pires R. F. , Lulhier F. L. G. , Vargas C. R.
Published: December 2002

Neurological dysfunction is common in patients with maple syrup urine disease (MSUD). However, the mechanisms underlying the neuropathology of this disorder are poorly understood. We determined the concentrations of all amino acids in plasma of patients with MSUD during crises (with severe CNS symptoms) and after recovery in the hope of detecting possible alterations of these levels during metabolic decompensation. Blood samples obtained from 11 children with MSUD aged 1 month to 7 years and from 10 age‐matched controls (5 months to 6 years) with no evidence of metabolic disease were examined for their amino acid content by high‐performance liquid chromatography. We observed that leucine, isoleucine and valine concentrations were respectively 30, 9 and 3 times higher than normal values, whereas the concentrations of the large neutral amino acids (LNAA) phenylalanine, tyrosine, tryptophan and methionine were significantly lower during metabolic decompensation as compared to the controls. In addition, concentrations of leucine, but not of valine or isoleucine, were inversely related to the LNAA concentrations in plasma. The concentrations of these amino acids in plasma returned to normal values when patients were clinically well. CSF amino acid concentrations also showed decreased amounts of LNAA and increased concentrations of branched‐chain amino acids. It is possible that the decrease in plasma concentrations of LNAA may lead to a deficit of these essential amino acids in the brain as well as of their products such as proteins and neurotransmitters, a fact that might be related to the neurological dysfunction of MSUD.