bluuebunny/crossref_metadata_2025 huggingface dataset:
Molecular dynamics study of water penetration in staphylococcal nuclease
Authors: Damjanović Ana , García‐Moreno Bertrand , Lattman Eaton E. , García Angel E.
Published: June 2005

The ionization properties of Lys and Glu residues buried in the hydrophobic core of staphylococcal nuclease (SN) suggest that the interior of this protein behaves as a highly polarizable medium with an apparent dielectric constant near 10. This has been rationalized previously in terms of localized conformational relaxation concomitant with the ionization of the internal residue, and with contributions by internal water molecules. Paradoxically, the crystal structure of the SN V66E variant shows internal water molecules and the structure of the V66K variant does not. To assess the structural and dynamical character of interior water molecules in SN, a series of 10‐ns‐long molecular dynamics (MD) simulations was performed with wild‐type SN, and with the V66E and V66K variants with Glu66 and Lys66 in the neutral form. Internal water molecules were identified based on their coordination state and characterized in terms of their residence times, average location, dipole moment fluctuations, hydrogen bonding interactions, and interaction energies. The locations of the water molecules that have residence times of several nanoseconds and display small mean‐square displacements agree well with the locations of crystallographically observed water molecules. Additional, relatively disordered water molecules that are not observed crystallographically were found in internal hydrophobic locations. All of the interior water molecules that were analyzed in detail displayed a distribution of interaction energies with higher mean value and narrower width than a bulk water molecule. This underscores the importance of protein dynamics for hydration of the protein interior. Further analysis of the MD trajectories revealed that the fluctuations in the protein structure (especially the loop elements) can strongly influence protein hydration by changing the patterns or strengths of hydrogen bonding interactions between water molecules and the protein. To investigate the dynamical response of the protein to burial of charged groups in the protein interior, MD simulations were performed with Glu66 and Lys66 in the charged state. Overall, the MD simulations suggest that a conformational change rather than internal water molecules is the dominant determinant of the high apparent polarizability of the protein interior. Proteins 2005. © 2005 Wiley‐Liss, Inc.
Computation of quantum mechanical hybridization and dipole correlation of the electronic structure of the F3B–NH3supermolecule
Authors: Ghosh Dulal C. , Bhattacharyya Soma
Published: June 2005

A valence bond description of the electronic structure and the process of the formation of the adduct supermolecule, F3B–NH3by charge transfer interactions between a Lewis acid, BF3, and a Lewis base, NH3, is computed in terms of the quantum mechanical localized molecular orbital (LMO) method. A dipole correlation of electronic structure is also reported. The valence bond description in terms of bond pair and lone pair is transparent in the generated LMOs of the donor, acceptor, and adduct supermolecule. It is transparent in the computed LMOs that the lone pair of N in NH3is actually involved in forming a new dative bond between B and N atoms. The present work reports the evaluated hybridization status of the boron, nitrogen, and fluorine atoms in the interesting donor–acceptor compound, F3B–NH3. It is transparent in the computed results that the quantum mechanical hybridization automatically incorporates the effect of change of environment in the pattern of hybridization perfectly in accordance with Bent's rule. The calculated dipole moment of the supermolecule is high; it is partitioned into contributions resulting from bond moments and atomic dipoles, as contributions from hybrid orbitals accommodating lone pairs of electrons. The magnitude of atomic dipole is small compared with the bond dipole component. A rationale of the bond moment of the molecule is attempted in terms of the charge density distribution on atomic sites and the atomic dipole is correlated in terms of the pattern of hybridization of lone pairs on the F atoms. The generated LMOs reveal that only one lone pair on each F atom is in a hybrid orbital, and the remaining two lone pairs are in pureporbitals. The small lone pair contribution to molecular dipole is thus transparent in computed quantum mechanical hybridization that shows that, out of three, only one lone pair on the F atoms can set in atomic dipole. This study demonstrates that atomic dipole can be used as a descriptor of the hybridization status of lone pairs on atoms in the molecules. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
The first and second derivative matrices in the random phase approximation scheme by using the Lagrangian technique
Authors: Gotoh Masashi , Tachikawa Masanori , Ryuo Kotaro , Sasagane Kotoku , Suzuki Kazunari , Mori Kazuhide , Nakamura Shinichiro
Published: June 2005

We have presented the explicit formulas for first and second derivatives of A and B matrices, appearing in the random phase approximation (RPA), with the aid of Lagrangian technique. Owing to the 2n + 1 rule, the Lagrangian approach is more efficient than the conventional approach to evaluate the higher‐order matrix elements. We have confirmed the validity of our formulation by demonstrating the geometry optimization of the first‐excited singlet states of formaldehyde, ethylene, and 1‐amino‐3‐propenal molecules. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Esophageal resection and by‐pass: A 6 year experience with a low postoperative mortality
Authors: Collard Jean ‐Marie , Otte Jean ‐Bernard , Reynaert Marc , Michel Luc , Carlier Marie ‐Anne , Kestens Paul ‐Jacques
Published: June 2005

From 1984 to 1989, 175 esophageal cancer patients, 10 patients admitted for severe caustic esophagitis, and 1 patient with pyothorax due to iatrogenic perforation of the esophagus underwent an esophageal resection or bypass operation. One hundred sixty‐eight esophageal resections were performed on 167 patients; 13 were total, 106 subtotal and 49 distal. Nineteen digestive transplants were pulled up to the neck to bypass the esophagus or re‐establish continuity after an esophagectomy made elsewhere. Digestive continuity was restored by a long gastric transplant in 120 patients, a colon segment in 17, a jejunal loop in 35, and a short gastric transplant after limited esophago‐gastrectomy in 14 patients. Thirty day mortality was 0 in the whole group. Hospital mortality was 1.2% in the resection group and 10.5% in the bypass group (p=0.048). Nonfatal postoperative complications consisted of respiratory distress in 33 patients, recurrent nerve palsy in 10, anastomotic fistula in 10 (cervical in 8 and intrathoracic in 2) and anastomotic stenosis in 18 patients. Respiratory complications were more frequent in patients with a cancer of the thoracic esophagus (29/111) than in those operated on for a cancer located in the esophago‐gastric junction (4/50) (p<0.01). Anastomotic stenosis occurred more frequently in the neck (17/137) than in the chest (1/49) (p<0.05). Nine patients were reoperated on for a technical complication; intraabdominal hemorrhage (1), thoracic duct injury (2), acute cholecystitis (1), tight stricture of the esophageal anastomosis (2), jejuno‐duodenal anastomotic fistula (2), or stridor related to recurrent nerve palsy (1). Low postoperative mortality may be achieved after esophageal surgery, even in a nonselected Caucasian population. However, nonfatal complications indicate that an esophageal resection or bypass operation remains a major surgical procedure. The surgical principles which we have applied to minimize postoperative mortality and severe complications are presented.
Hereditary variation of liver enzymes involved with detoxification and neurodegenerative disease
Authors: Williams A. C. , Steventon G. B. , Sturman S. , Waring R. H.
Published: June 2005

Enzymes involved with the metabolic transformation of xenobiotics have recently been studied in patients with the neurodegenerative diseases, Alzheimer's disease, Parkinson's disease and motor neurone disease. Defects were detected in sulphur pathways and also, in the case of Parkinson's disease, in monoamine oxidase B. The possibility exists that the ability to cope safely with endogenous and exogenous substances which have neurotoxic properties is important in the pathogenesis of these diseases. Potentially such individuals could be identified preclinically and these diseases postponed by reduction in the load of toxin or modification of the relevant enzymic activity.
Interrelationships of liver and brain with special reference to reye syndrome
Authors: Brown J. K. , Imam H.
Published: June 2005

Reye syndrome is an acute non‐inflammatory encephalopathy that can be precipitated by toxic, infective, metabolic or hypoxic upsets. The biochemical changes point to mitochondrial dysfunction and this is substantiated by structural changes in mitochondria on electron microscopy. The toxic metabolites that accumulate are similar to those incriminated in hepatic encephalopathy and other metabolic diseases. These metabolites exert their deleterious effects by direct neuronal damage, neurotransmitter blockade, vascular damage, cerebral oedema, hypoxic ischaemic damage, demyelination, retardation of brain growth and neuronal storage. Brain capillary endothelial cells are very rich in mitochondria and mitochondrial disorders can effect the central nervous system primarily, and not just as a consequence of systemic metabolic upset.
Techniques for studying hepatic metabolismin vivo
Authors: Leonard J. V. , Thompson G. N.
Published: June 2005

Techniques for studying metabolic eventsin vivo in patients with inborn errors are reviewed. Loading or provocation tests that have been used widely are insensitive and frequently non‐specific. Compounds labelled with stable isotopes can be used to study enzyme kinetics and substrate turnover, providing more detailed and specific information. Intracellular events may be studied using nuclear magnetic resonance spectroscopy.

The results using these techniques to study patients with selected inborn errors are discussed, namely phenylketonuria, glycogen storage disease type I and propionic acidaemia.
Tyrosinaemia type I — an update
Authors: Kvittingen E. A.
Published: June 2005

Tyrosinaemia type I is a recessively inherited disorder caused by a deficiency of fumarylacetoacetase (FAH), the last enzyme in tyrosine degradation. The presumed toxic agents are fumaryl‐ and maleylacetoacetate which are converted to succinylacetone (SA), a metabolite found in increased amounts in urine and plasma of the patients. The major clinical features are progressive liver damage and renal tubular defects with hypophosphataemic rickets. Renal tubular dysfunctions with secondary rickets may be lacking altogether, even in chronic patients. Hepatocellular carcinoma is a major cause of death in the chronic form. Diagnosis of the disorder is made by assay of SA in urine and serum and by determination of FAH in lymphocytes or fibroblasts. Prenatal diagnosis is performed by SA assay in amniotic fluid supernatant and FAH analysis in cultured amniotic fluid cells or chorionic villus material. Presence of a ‘pseudodeficiency’ gene for FAH prevents prenatal diagnosis by enzyme analysis in some families, and this gene also precludes identification of heterozygotes outside tyrosinaemia families. Immunoblot analyses show that acute patients and some chronic patients lack immunoreactive FAH protein. cDNA probes for FAH have been developed and several polymorphisms related to the FAH gene have been reported, which may allow prenatal diagnosis in families with complex genotypes. The gene for FAH has been mapped to chromosome 15 q23–q25. Liver transplantation is the ultimate treatment; most patients continue to excrete SA in urine after liver transplantation and therefore there is a possibility of kidney disease after transplantation.
Investigation of the molecular basis of the genetic deficiency of UDP‐glucuronosyl‐transferase in Crigler‐Najjar syndrome
Authors: Robertson K. J. , Clarke D. , Sutherland L. , Wooster R. , Coughtrie M. W. H. , Burchell B.
Published: June 2005

Liver biopsy samples were obtained from eight Crigler‐Najjar patients. Bilirubin UDPGT activity, assayed by a microassay with HPLC analysis, was not detectable in type I livers, and low levels (9–26% of controls) of monoglucuronide conjugates only were observed in type II livers. 1‐Naphthol UDPGT activity was normal in most patients, where membrane integrity was maintained by correct sample procurement and preparation. Our data on type II livers suggest that a defect in UDPGA transport is an unlikely cause of the hyperbilirubinaemia, but reduced affinity for UDPGA was observed in one sample. Analysis of four patient liver samples by immunoblot analysis revealed the heterogeneous nature of this inherited disease within the patient population, and one sample where 1‐naphthol UDPGT activity was considerably reduced appeared to correlate with the non‐detection of a phenol UDPGT protein. Progress towards a molecular genetic diagnosis of Crigler‐Najjar syndromes is discussed.
Treatment of inherited metabolic disorders by liver transplantation
Authors: Burdelski M. , Rodeck B. , Latta A. , Latta K. , Brodehl J. , Ringe B. , Pichlmayr R.
Published: June 2005

Among the worldwide accepted indications for liver transplantation, inherited metabolic disorders play an increasing role. In some paediatric centres this indication runs second after extrahepatic biliary atresia.

The aim of liver transplantation in inherited metabolic disorders is twofold: the first is to save a patient's life, the second is to accomplish phenotypic and functional cure of his disease. These aims may be achieved in disorders presenting with cirrhosis, hepatoma, life‐threatening progression or failure of other organs with preserved liver function. The timing of liver transplantation has become easier with development of surgical techniques of reduced‐size donor livers. These techniques enable the performance of liver transplantation with ABO blood group compatible organs of almost any size if indicated either by deterioration of liver function or impending complications such as hepatoma or life‐threatening progression. In comparison with other indications such as extrahepatic biliary atresia, postnecrotic liver cirrhosis or acute liver failure, the results of transplantation in patients with inherited metabolic disorders seem to be better, reaching up to 78–95% actuarial 1‐year survival rates. However, lifelong immunosuppressive therapy is necessary. This seems to be acceptable even in disorders with only partial liver function defects.
The place of fetal liver transplantation in the treatment of inborn errors of metabolism
Authors: Touraine J. ‐L. , Laplace S. , Rezzoug F. , Sanhadji K. , Veyron P. , Royo C. , Maire I. , Zabot M. T. , Vanier M. T. , Rolland M. O. , Goillot E. , de Bouteiller O. , Garnier J. L. , Pouteil‐Noble C. , Raffaele P. , Livrozet J. M. , Saint‐Marc T.
Published: June 2005

Over the last 16 years, 202 fetal tissue transplants have been performed in our department to treat 29 patients with severe inborn errors of metabolism without immunodeficiency, 26 patients with congenital and severe immunodeficiency diseases, and 2 patients with severe aplastic anaemia. The actuarial survival curve of patients with inborn errors of metabolism treated with fetal liver transplantation shows a 12‐year survival of 77%. The condition of many of these patients has been improved by the treatment, but transplantation has had to be repeated in order to maintain clinical amelioration. Enzyme levels were not significantly and durably increased in peripheral blood but the quantities of substrates detected in sera and urines were significantly reduced and tissue deposits were stabilized.
I‐cell disease
Authors: Patel Z. M. , Ambani L. M.
Published: June 2005

A 6‐month‐old female infant presented with severe psychomotor retardation, coarse facies, gingival hyperplasia, thick skin, restricted joint movements and radiological features suggestive of the Hurler syndrome. Her urine showed no excess excretion of mucopolysaccharides. I‐cell disease was suspected from the onset of clinical features in early infancy, the subsequent progress and the absence of mucopolysacchariduria. Marked elevation of the activity in serum of three lysosomal enzymes confirmed the diagnosis. This patient had repeated convulsions, a feature not previously reported in this condition. This is the first case report of I‐cell disease from India.
Skeletal muscle of patients with gyrate atrophy of the choroid and retina and hyperornithinaemia in ultralow‐field magnetic resonance imaging and computed tomography
Authors: Valtonen M. , Näntö‐Salonen K. , Heinänen K. , Alanen A. , Kalimo H. , Simell O.
Published: June 2005

Gyrate atrophy of the choroid and retina with hyperornithinaemia (GA), an autosomal recessive disease, affects skeletal muscle in addition to the eye. Muscle biopsy samples show prominent type 2 muscle fibre atrophy. Atrophic fibres also contain accumulations of tubular aggregates in electron microscopy. To evaluate skeletal muscle involvement in detail, the thigh muscles of 7 patients with GA were examined using semi‐open conchotome muscle biopsies, computed tomography (CT) and ultralow‐field magnetic resonance imaging (MRI) at 0.02 T. In MRI, the T1 and T2 proton relaxation times were measured. Type 2 muscle fibre atrophy was found in all biopsy samples (100%) and tubular aggregates in 6 of the 7 samples studied (87%). The CT density of the muscle tissue was increased in the only child of the study, decreased in 3 elderly subjects, and normal in the remaining 3 patients. Mean T1 relaxation times of the patients were decreased (135±5 ms) as compared to those of 6 healthy controls (157±12 ms) (p=0.002). The T2 relaxation time was slightly increased (40±3 ms) as compared to the controls (35±7 ms; not significant,p=0.3). Our findings suggest that the thigh muscles of the patients with GA universally show changes in CT and MRI studies, but relaxation time measurements gave little additional information on the muscle metabolism.
Rapid identification of PKU‐associated mutations by multiplex DGGE analysis of the PAH gene
Authors: Michiels L. , François B. , Raus J. , Vandevyver C.
Published: June 2005

A system of five sets of multiplex polymerase chain reaction amplifications followed by denaturing gel electrophoresis analysis allows rapid analysis of all 13 exons of the phenylalanine hydroxylase gene.
Late‐onset holocarboxylase synthetase deficiency
Authors: Gibson K. M. , Bennett M. J. , Nyhan W. L. , Mize C. E.
Published: June 2005

We report a 21‐month‐old female patient whose urine organic acid profile suggested a biotin utilization abnormality consistent with multiple carboxylase deficiency. For most previously reported patients, holocarboxylase synthetase deficiency has correlated with the early‐onset variant of multiple carboxylase deficiency; conversely, biotinidase deficiency has been characteristic of the late‐onset form.In vitro enzyme studies revealed that our patient suffered from holocarboxylase synthetase deficiency. We suggest that holocarboxylase synthetase deficiency should be considered in the differential diagnosis of older patients in whom there is suspicion of a defect in biotin metabolism.
Complementation analysis of systemic cytochrome oxidase deficiency presenting as Leigh syndrome
Authors: Brown R. M. , Brown G. K.
Published: June 2005

Systemic cytochrome oxidase deficiency presenting as Leigh syndrome is a well‐defined biochemical entity. Although the enzyme defect is demonstrable in all tissues, clinical abnormalities are restricted to the central nervous system. Biochemical studies comparing rates of synthesis of cytochrome oxidase subunits with the steady‐state levels of immunoreactive protein in the mitochondrial inner membrane suggest a defect in assembly or stability of the complex. Family studies suggest that the disease is inherited as an autosomal recessive and somatic cell genetic studies directly implicate nuclear genes. As there are likely to be a number of different nuclear genes involved in the synthesis, assembly and stability of the cytochrome oxidase complex, we have fused patient fibroblasts and analysed the heterokaryons for complementation of the enzyme defect in an attempt to define the extent of genetic heterogeneity in this condition. So far, three complementation groups have been defined, although the majority of patients fall into a single group.
A D255H substitution in the arylsulphatase A gene of two unrelated Belgian patients with late‐infantile metachromatic leukodystrophy
Authors: Lissens W. , Vervoort R. , Van Regemorter N. , Van Bogaert P. , Freund M. , Verellen‐Dumoulin C. , Seneca S. , Liebaers I.
Published: June 2005

Metachromatic leukodystrophy (MLD) is an autosomal recessive disease of myelin metabolism caused by a deficiency in the lysosomal enzyme arylsulphatase A (ARSA). We have identified a new mutation in exon 4 of the ARSA gene of two unrelated Belgian patients with late‐infantile MLD. The mutation predicts an aspartic acid‐to‐histidine substitution at position 255 in arylsulphatase A (D255H), in a highly conserved region among sulphatases. Transient expression of the mutation in COS cells did not show an increase in ARSA activity. Both patients were compound heterozygotes carrying the frequent splice site mutation in intron 2 (459+1G→A) on the other allele.
The effect of ethanol on glucose production in phosphorylase b kinase deficiency
Authors: Collins J. E. , Bartlett K. , Leonard J. V. , Aynsley‐Green A.
Published: June 2005

Glucose production was measured using stable isotopic techniques in two patients with phosphorylase b kinase deficiency before and after oral ethanol (0.75 g/kg). Glucose production was normal before the ethanol. In one patient, who did not take the full dose of ethanol, glucose production rose initially and then fell. In the other, glucose production fell steadily and in both patients blood lactate concentrations rose. Blood glucose concentrations decreased.

Patients with this enzyme deficiency are dependent on the gluconeogenic pathway when fasting and, therefore, ethanol may be potentially hazardous.
Dermatoglyphic study in children with phenylketonuria
Authors: Balci S. , Tanzer F. , Atasu M. , Özalp İ
Published: June 2005

Dermatoglyphic findings in 19 patients with phenylketonuria (11 male and 8 female), 39 of their relatives (18 female and 21 male) and 500 controls (TRC) were not statistically significant among the three groups studied. There was no definite relationship between the phenylketonuric gene and the dermatoglyphic patterns.

The parents of half the phenylketonuria cases are not consanguineous; thus the phenylketonuria gene may be more frequent in Turkey than other European countries.
Incidence and features of galactosaemia in Saudi Arabs
Authors: Moammar H. , Ratard R. , Cheriyan G. , Mathew P.
Published: June 2005

Over a 12‐year period (1983 to 1994), 11 cases of classical galactosaemia were identified in the Saudi Aramco Medical Services Organization (SAMSO). This yields an incidence of 12 cases per 100 000 live births in the Eastern Province of Saudi Arabia. A higher proportion of infants presented with infections compared to reports in the literature. Screening for galactosaemia is highly recommended in this high‐risk population.
l‐2‐Hydroxyglutaric aciduria: Neuropathological correlations and first report of severe neurodegenerative disease and neonatal death
Authors: Chen E. , Nyhan W. L. , Jakobs C. , Greco C. M. , Barkovich A. J. , Cox V. A. , Packman S.
Published: June 2005

l‐2‐Hydroxyglutaric aciduria is a rare organic aciduria associated with neurological and particularly cerebellar abnormalities. These abnormalities developed in childhood or later in all previously described patients. We report a more severe form ofl‐2‐hydroxyglutaric aciduria in which an infant presented shortly after birth with hypotonia, apnoea, and seizures, leading to death in the perinatal period. Computerized tomography scans of the brain at 1 day and 2 weeks of age showed abnormal low density of the cerebellum. Examination of the brain showed brainstem and cerebellar atrophy with neuronal loss and gliosis in an olivopontocerebellar distribution. The diagnosis ofl‐2‐hydroxyglutaric aciduria should be considered in any non‐dysmorphic newborn with progressive neurological abnormalities and CNS imaging suggesting low density and size of the cerebellum. The diagnostic consideration is based initially on clinical findings. Conventional urine organic acid analysis reveals the presence of 2‐hydroxyglutaric aciduria. Specific diagnosis requires methodologies which distinguish thel‐ from thed‐isomer.
Prenatal and postnatal diagnosis of menkes disease, an inherited disorder of copper metabolism
Authors: Tønnesen T. , Horn N.
Published: June 2005

105 patients with Menkes disease have been diagnosed from64Cu‐uptake studies in fibroblasts. These results are presented together with chase results following removal of64Cu from the medium for 16 Menkes patients. Second‐trimester prenatal diagnosis has been performed in 80 pregnancies with male karyotype. These64Cu‐uptake results show some overlap between the upper end of the normal range and the lower end of the Menkes range. Results are presented to show that a combination of64Cu‐uptake and chase results offers a better diagnostic potential than64Cu‐uptakeper se. Chorionic villus copper values from 53 first‐trimester prenatal diagnoses are presented. Maternal deciduum from some of these pregnancies contain similar high amounts of copper as found in the chorionic villus samples from affected fetuses.64Cu‐uptake in cultured chorionic villi from affected fetuses and unaffected fetuses is not discriminatory. Chase results seem however to offer a better diagnostic potential.
The inborn errors of peroxisomal β‐oxidation: A review
Authors: Wanders R. J. A. , van Roermund C. W. T. , Schutgens R. B. H. , Barth P. G. , Heymans H. S. A. , van den Bosch H. , Tager J. M.
Published: June 2005

In recent years a growing number of inherited diseases in man have been recognized in which there is an impairment in peroxisomal β‐oxidation. In some diseases this is due to the (virtual) absence of peroxisomes leading to a generalized loss of peroxisomal functions including peroxisomal β‐oxidation. In most inborn errors of peroxisomal β‐oxidation, however, peroxisomes are normally present and the impairment in peroxisomal β‐oxidation is due to the single or multiple loss of peroxisomal β‐oxidation enzyme activities. In all these disorders there is accumulation of very‐long‐chain fatty acids in plasma, which allows biochemical diagnosis of patients affected by an inborn error of peroxisomal β‐oxidation to be done via gas‐chromatographic analysis of plasma very‐long‐chain fatty acids. Subsequent enzymic and immunological investigations are required to identify the precise enzymic defects in these patients. In all inborn errors of peroxisomal β‐oxidation known today there are multiple abnormalities, especially neurological with death usually occurring in the first decade of life. Prenatal diagnosis of these disorders has recently become possible.
A comparison of [9,10‐3H]palmitic and [9,10‐3H]myristic acids for the detection of defects of fatty acid oxidation in intact cultured fibroblasts
Authors: Manning N. J. , Olpin S. E. , Pollitt R. J. , Webley J.
Published: June 2005

The production of tritiated water from [9,10‐3H]myristic acid can be used as a screening assay for the detection of medium‐chain acyl‐CoA dehydrogenase deficiency, multiple acyl‐CoA dehydrogenation defects (glutaric aciduria type 2 and ethylmalonic‐adipic aciduria types), and some types of hydroxydicarboxylic aciduria. Comparison with the release of tritiated water from [9,10‐3H]palmitic acid may give an indication of the chain‐length specificity of the metabolic defect. In a case of ethylmalonic‐adipic aciduria such a prediction has been confirmed by examination of accumulated intermediates in the affected fibroblasts.
Carnitine deficiency with cardiomyopathy presenting as neonatal hydrops: Successful response to carnitine therapy
Authors: Steenhout P. , Elmer C. , Clercx A. , Blum D. , Gnat D. , van Erum S. , Vertongen F. , Vamos E.
Published: June 2005

A small‐for‐date infant presented at birth with severe non‐immune hydrops, cardiac failure, metabolic acidosis and hypoglycaemia. Ultrasonography disclosed a cardiomyopathy. Initial therapy consisting of artificial ventilation, inotropes and diuretics resulted in partial disappearance of oedema without significant improvement in cardiac function. Episodes of hypoglycaemia recurred despite continuous glucose influsions.

Total serum carnitine from cord blood was 1.65 nmoles/ml and was undetectable on day 20. Oraldl‐carnitine supplements resulted in normoglycaemia, dramatic improvement in cardiac function and restoration of serum carnitine levels to normal values. The infant was thereafter maintained on carnitine therapy. Follow‐up over 1 year showed moderate growth retardation and normal developmental milestones.

In order to account for such a severe neonatal presentation of carnitine deficiency, a combination of defective pre‐ and postnatal carnitine supply with an inborn error of carnitine handling is considered. The present case illustrates the need for evaluation of carnitine status in fetuses and neonates presenting with hydrops associated with cardiac failure.
Comparison of patients with complete and partial biotinidase deficiency: Biochemical studies
Authors: Suormala T. M. , Baumgartner E. R. , Wick H. , Scheibenreiter S. , Schweitzer S.
Published: June 2005

Seventeen partially biotinidase‐deficient patients detected by neonatal screening or family studies were compared with four patients with classical biotinidase deficiency. Using a sensitive HPLC method for biotinidase in plasma (substrate: biocytin) the patients could be divided into two groups: one with residual biotinidase activity, and the second with undetectable biotinidase activity (0‐activity). Biocytin excretion, characteristically elevated in 0‐activity patients, decreased rapidly with increasing residual biotinidase activity and was almost normal when residual activity exceeded 2–3% of mean normal. In one patient with classical disease (0‐activity) biotin deficiency, typical organic aciduria and multiple carboxylase deficiency were found as early as at the second week of life. In contrast, 13 infants with residual activities from 1.2% to 23% had no remarkable clinical or biochemical abnormalities. However, in three 5‐, 14‐ and 15‐year‐old healthy siblings with residual biotinidase activities between 2.3% and 4.2%, biotin deficiency was proven by decreased activities of the mitochondrial carboxylases in lymphocytes (30–57% of mean normal) and, in the older siblings, also by subnormal plasma biotin concentrations. In biotinidase deficiency, biotin depletion presumably occurs earlier in the brain than in other tissues and may thus first affect the central nervous system. For this reason and because of discrete biochemical abnormalities found in a patient with residual biotinidase activity of 8%, we suggest that at least all patients with residual activities below 10% should be treated with biotin.
Type I glycogen storage disease with vasoconstrictive pulmonary hypertension
Authors: Furukawa N. , Kinugasa A. , Inoue F. , Imashuku S. , Takamatsu T. , Sawada T.
Published: June 2005

A case of glycogen storage disease (GSD) type I with vasoconstrictive pulmonary hypertension is described.
Identification of new mutations in the ornithine transcarbamylase (OTC) gene in Korean families
Authors: Yoo H.‐W. , Kim G.‐H. , Lee D.‐H.
Published: June 2005

Ornithine transcarbamylase (OTC) deficiency, an X‐linked inborn error of the urea cycle, is known to be heterogeneous genetically as well as phenotypically. Molecular defects of Korean patients with OTC deficiency have not been reported. To investigate molecular lesions resulting in OTC deficiency, the OTC genes of unrelated symptomatic or asymptomatic female heterozygotes were amplified exon by exon and analysed by direct sequencing of double‐stranded DNA. Three new mutations, two missense and one nonsense, were detected: (1) a C‐to‐T transition in codon 44 in exon 2 replacing a threonine by an isoleucine (T44I) was found in a late‐onset symptomatic female patient but not in her asymptomatic mother; (2) a C‐to‐T transition in codon 214 creating a newRsaI recognition site in exon 6 and substituting tyrosine for histidine (H214Y) was identified in an asymptomatic female carrier whose son developed acute neonatal onset of OTC deficiency; (3) a C‐to‐T transition in codon 320 (arginine) abolishing aTaqI recognition site and creating a newBClI site in exon 9 with generation of a stop codon (R320X) leading to premature termination in the enzyme. This nonsense mutation was found in a symptomatic female patient and her asymptomatic mother whose son died of OTC deficiency during the neonatal period. In addition, we found a G‐to‐A transition in codon 141 in exon 5 causing substitution of glutamine for arginine (R141Q) in a female obligate heterozygote whose previous three sons succumbed to acute neonatal‐onset OTC deficiency. This missense mutation has been described previously and is known to eliminate aTaqI recognition site in exon 5.
Comparative biochemical studies in fibroblasts from patients with different forms of Leigh syndrome
Authors: Vazquez‐Memije M. E. , Shanske S. , Santorelli F. M. , Kranz‐Eble P. , Davidson E. , De Vivo D. C. , DiMauro S.
Published: June 2005

We have compared respiratory chain enzyme activities, ATP synthesis, and ATP hydrolysis in cultured fibroblast mitochondria from patients with Leigh syndrome (LS) due to: (i) cytochrome oxidase (COX) deficiency (#6); (ii) pyruvate dehydrogenase complex (PDHC) deficiency (#4); and (iii) maternally inherited LS (MILS) with the T8993G mutation in the ATPase 6 gene of mtDNA (#5). Enzyme activities were normal in patients with MILS and variably decreased in those with COX and PDHC deficiency. ATP hydrolysis was normal or mildly decreased in all three groups. In contrast, ATP synthesis was decreased in all patients but more markedly in those with MILS, and especially with pyruvate/malate as substrate. These studies show that impaired ATP production is the common feature of all three forms of LS, but it is both more severe and more specific in MILS, consistent with the genetic defect.
Pyruvate carboxylase defect: Metabolic studies on cultured skin fibroblasts
Authors: Oizumi J. , Ng W. G. , Donnell G. N.
Published: June 2005

Oxidative studies using a number of radioactive carbon‐labelled substrates on intact cultured skin fibroblasts from a patient with pyruvate carboxylase deficiency revealed dysfunction of the Krebs cycle. The suppression of CO2 production from aspartate but not glutamine strongly suggests that the defective function lies in the aspartate‐malate shuttle. Furthermore, there is an unusual dependence on glutamine for the maintenance of growth of the patient's cells compared to normal cells. Glutamine could not be replaced by aspartate supplementation. A secondary defect resulting in accumulation of lipid material was also demonstrated in this study.

It is speculated that the intracellular level of oxaloacetate may also be diminished in the patient's cells. Oxaloacetate is primarily generated by the carboxylation of pyruvate catalysed by pyruvate carboxylase.
Partial deficiency of dihydroxyacetone phosphate acyltransferase activity in both classical and infantile Refsum's diseases
Authors: Van Crugten J. T. , Paton B. , Poulos A.
Published: June 2005

We measured the activity of dihydroxyacetone phosphate acyltransferase (DHAP‐AT) in fibroblasts of controls and patients with classical Refsum's disease (RD), infantile Refsum's disease (IRD) and Zellweger's syndrome (ZS). We confirmed that DHAP‐AT activity is severely reduced in ZS fibroblasts and amniocytes. We also demonstrated a partial deficiency of DHAP‐AT activity in RD and IRD fibroblast cultures. These diseases are probably distinct but related entities in which peroxisomal biogenesis is affected to varying degrees.
Ornithine transcarbamylase deficiency: a case with a truncated enzyme precursor and a case with undetectable mRNA activity
Authors: Kodama H. , Ohtake A. , Mori M. , Okabe I. , Tatibana M. , Kamoshita S.
Published: June 2005

The cell‐free translation of ornithine transcarbamylase (OTC) mRNA from the livers of two heterozygous patients (from different families) with OTC deficiency was performed. The enzyme activities and the immunoreactive proteins in both patients were about 5% of those in controls. Immunoblotting assay of liver extracts from both patients showed decreased amounts of the OTC protein. The mRNA from the liver of patient 1 directed the synthesis of a very small amount of OTC precursor of normal subunit size (40 000 Da), whereas that from patient 2 directed the synthesis of small amounts of two distinctin vitro products; one was 40 000 Da and the other was about 30 000 Da. Thein vitro product of normal precursor synthesized with mRNA from patient 2 was converted to mature‐sized OTC by isolated rat liver mitochondria, whereas the smaller product was degraded during the incubation with the mitochondria. These results indicate that in both patients the translatable level of mRNA for active OTC from liver cells was much lower than that in the controls. The results also suggest that in patient 2, the smaller product presumably derived from an abnormal gene could not be transferred to the mitochondria.
A new patient with hyperornithinaemia, hyperammonaemia and homocitrullinuria treated early with low protein diet
Authors: Gjessing L. R. , Lunde H. A. , Undrum T. , Broch H. , Alme A. , Lie S. O.
Published: June 2005

The characteristic biochemical disturbances of the amino acid and pyrimidine metabolism are described and illustrated by the first case of the HHH syndrome reported in Norway. The disorder was treated with a low protein diet at an early age and the patient developed normally on this diet.
Plasma amino acid values and pancreatic β‐cell function in phenylketonuria
Authors: Antonozzi I. , Carducci C. , Vestri L. , Manzari V. , Dominici R.
Published: June 2005

In 16 phenylketonuric (PKU) patients aged 5–12 years, plasma glucose, immunoreactive insulin (IRI), C‐peptide (CP) and plasma amino acids were measured in basal conditions and under a standard oral glucose tolerance test (OGTT).

The β‐cell response to OGTT was higher in PKU patients than in normal subjects as demonstrated by peak levels and areas under the curves of plasma concentrations of IRI and of CP. A significant correlation was observed between plasma phenylalanine values and both IRI and CP ‘output’ in PKU patients. Mean concentrations of branched chain amino acids and tyrosine in plasma decreased significantly during OGTT, while phenylalanine values increased in PKU subjects.
A new family affected by the syndrome of hyperornithinaemia, hyperammonaemia and homocitrullinuria
Authors: Rodes M. , Ribes A. , Pineda M. , Alvarez L. , Fabregas I. , Alvarez E. Fernandez , Coude F. X. , Grimber G.
Published: June 2005

We have reported three cases of hyperornithinaemia associated with hyperammonaemia and homocitrullinuria (HHH). They deal with two brothers and a sister from a family where the parents and four other children are healthy on clinical and biochemical examination. The biochemical findings in our patients indicate the existence of a defect in the transport of ornithine into the mitochondria. Cultured skin fibroblasts from two of these patients incorporated six times less [14C]ornithine into protein as compared to control cells. The most characteristic sign of the clinical picture is the progressive spastic paraparesis found in one of the cases. Ornithine supplementation and restricted protein intake may be useful in the treatment of this syndrome since after three years of treatment the clinical response was favourable and the patients showed no adverse clinical effects.
Molecular genetics of phosphorylase kinase: cDNA cloning, chromosomal mapping and isoform structure
Authors: Kilimann M. W.
Published: June 2005

A deficiency in phosphorylase kinase is responsible for several forms of glycogen storage disease which differ in heredity and affected tissues. This is so because phosphorylase kinase consists of four different subunits and has multiple tissue‐specific isoforms. To elucidate the molecular basis of phosphorylase kinase deficiencies, the cDNAs encoding the subunitsα andβ were cloned and sequenced. Each subunit was shown to be encoded by a single gene. Theα subunit gene was mapped to chromosome Xq12–q13 and theβ subunit gene to chromosome 16q12–q13. Isoform cDNAs reveal differential mRNA splicing. Thus, the stage is set for the molecular characterization of the genes and their deficiency mutations.
Disorders of glycoprotein degradation
Authors: Cantz M. , Ulrich‐Bott B.
Published: June 2005

The intracellular degradation of glycoproteins occurs predominantly in the lysosomes through the concerted action of proteases and glycosidases. Genetic defects in any of the enzymes cleaving the oligosaccharide side chains lead to specific diseases because of an excessive lysosomal accumulation of partially degraded material, mostly oligosaccharides.

This paper presents an overview of the biochemistry and the clinical spectrum of this group of diseases including sialidosis, galactosialidosis,α‐andβ‐mannosidosis, fucosidosis, aspartylglucosaminuria, andα‐N‐acetylgalactosaminidase deficiency (Schindler disease). In addition, the sialic acid storage disorder (Salla disease) which is caused by a defect in the lysosomal transport of this acidic monosaccharide is included because of functional and clinical correlations.
α‐ andβ‐mannosidoses
Authors: Cooper A. , Hatton C. E. , Thornley M. , Sardharwalla I. B.
Published: June 2005

Clinical, pathological and biochemical findings in the mannosidoses are described. Family studies showed granulocyte‐rich white cell fractions to be the tissue of choice for carrier detection inβ‐mannosidosis. Metabolic labelling studies using [3H] mannose demonstrated accumulation of Manβ1‐4GlcNAc in cultured skin fibroblasts from a patient with this condition. Alternative methods of egress from lysosomes were suggested for this compound by its secretion into culture medium and apparent reduction of storage with time in cultures.β‐mannosidase deficient goats are not thought to be a true animal model of the human condition, as although they showed a similar enzyme deficiency, the clinical presentation is much more severe and the major storage material (Manβ1‐4GlcNAcβ1‐4GlcNAc) is different.
Clinical application of somatic gene therapy in inborn errors of metabolism
Authors: Ledley F. D.
Published: June 2005

Rapid advances in recombinant DNA and gene transfer technologies provide the potential for somatic gene therapy of inborn errors of metabolism in which the genetically defective function will be restored by transfer of a normal gene into somatic cells. The therapeutic potential and safety of gene therapy has been explored in cultured cells and experimental animals, but therapeutic clinical trials have not yet been proposed or performed. The technologies which may make somatic gene replacement therapy feasible need to be considered and criticised from a clinical perspective. Clinical trials will be necessary to determine the efficacy of somatic gene therapy and address concerns about safety.
Fetal damage due to maternal phenylketonuria: Effects of dietary treatment and maternal phenylalanine concentrations around the time of conception
Authors: Smith I. , Glossop J. , Beasley M.
Published: June 2005

In 94 infants born to women with PKU, birth weight and head circumference were inversely and linearly related to the mothers' phenylalanine concentrations close to conception; with each 200 µmol/L rise in phenylalanine concentrations, birth weight fell by 98 g and head circumference by 0.46 cm. This relationship was highly significant and appeared to be the same whether or not the mother received a low phenylalanine diet. Even in the 28 infants whose mothers conceived on a strict low phenylalanine diet, birth weights and head circumferences, corrected for sex and gestation, were a little below the population norms (3421 g and 34.7 cm compared with 3600 g and 35.2 cm respectively) although the differences were not statistically significant. Optimal fetal growth occurred only in infants whose mothers had phenylalanine concentrations close to the normal range at conception. Dietary treatment started after conception did not appear to confer any benefit.
Analysis of abnormal urinary metabolites in the newborn period in medium‐chain acyl‐CoA dehydrogenase deficiency
Authors: Bennett M. J. , Coates P. M. , Hale D. E. , Millington D. S. , Pollitt R. J. , Rinaldo P. , Roe C. R. , Tanaka K.
Published: June 2005

In order to determine which are useful early diagnostic markers for medium‐chain acyl‐CoA dehydrogenase (MCAD) deficiency, we have analysed urine from an asymptomatic neonate. Profiling of urinary organic acids followed by peak confirmation by electron impact mass spectrometry revealed a high suberate/adipate ratio (>1.0) and the presence of n‐hexanoylglycine (HG). Acylcarnitine analysis by fast atom bombardment mass spectrometry (FAB‐MS) was inconclusive, but FAB‐MS/MS (tandem mass spectrometry) revealed diagnostic amounts of octanoylcarnitine and hexanoylcarnitine. Quantitative analysis of acylglycines by stable istotope dilution and chemical ionization mass spectrometry revealed a 30‐fold increase in HG and increased suberylglycine, but no increase in 3‐phenylpropionylglycine.
Fatty acid transport in multiple carboxylase deficiency fibroblasts
Authors: Packman S. , Whitney S.
Published: June 2005

Holocarboxylase synthetase (HS) and biotinidase deficiencies have been identified as causes of biotin‐responsive multiple carboxylase deficiency. Acetyl‐CoA carboxylase (ACC) deficiency has been shown to occur in multiple carboxylase deficiency, and HS(−) fibroblasts are being employed to investigate compensatory regulatory responses in cells deficient in ACC. In previous studies, biotin starved HS(−) fibroblasts showed a reduced fatty acid content, an abnormal percentage composition of fatty acids, and a preservation of longerchain fatty acid contents of cells. We herein ask whether the mutant cells show compensatory increases in the transport of longer‐chain fatty acids from the medium into fibroblasts. In the present experiments there was no change in the uptake of arachidonate, palmitate or oleate following growth of mutant and control fibroblasts in (+) or (−) biotin conditions. Differential fatty acid uptake from the medium is therefore not a compensatory mechanism in HS(−) cells, and cannot account for the specific changes in fatty acid composition produced by biotin restriction.