Adenosine deaminase (ADA) deficiency is an inherited disorder which leads to elevated cellular levels of deoxyadenosine triphosphate (dATP) and systemic accumulation of its precursor, 2‐deoxyadenosine. These metabolites impair lymphocyte function, and inactivate S‐adenosylhomocysteine hydrolase (SAHH) respectively, leading to severe immunodeficiency. Enzyme replacement therapy with polyethylene glycol‐conjugated ADA is available, but its efficacy is reduced by anti‐ADA neutralising antibody formation. We report here carrier erythrocyte encapsulated native ADA therapy in an adult‐type ADA deficient patient. Encapsulated enzyme is protected from antigenic responses and therapeutic activities are sustained. ADA‐loaded autologous carrier erythrocytes were prepared using a hypo‐osmotic dialysis procedure. Over a 9‐yr period 225 treatment cycles were administered at 2–3 weekly intervals. Therapeutic efficacy was determined by monitoring immunological and metabolic parameters. After 9 yr of therapy, erythrocyte dATP concentration ranged between 24 and 44 μmol/L (diagnosis, 234) and SAHH activity between 1.69 and 2.29 nmol/h/mg haemoglobin (diagnosis, 0.34). Erythrocyte ADA activities were above the reference range of 40–100 nmol/h/mg haemoglobin (0 at diagnosis). Initial increases in absolute lymphocyte counts were not sustained; however, despite subnormal circulating CD20+ cell numbers, serum immunoglobulin levels were normal. The patient tolerated the treatment well. The frequency of respiratory problems was reduced and the decline in the forced expiratory volume in 1 s and vital capacity reduced compared with the 4 yr preceding carrier erythrocyte therapy. Carrier erythrocyte‐ADA therapy in an adult patient with ADA deficiency was shown to be metabolically and clinically effective.

McGregor et al. reported increased levels of an unidentified urinary compound (CFSUM1) in patients with chronic fatigue syndrome (CFS), with reduced excretion of another unidentified compound (CFSUM2), and suggested the possibility of chemical or metabolic 'markers' for CFS. The identity of CFSUM1 as reported was erroneous and the identities of these compounds have remained unknown until now. Urine samples were obtained from 30 patients with ME/CFS, 30 age- and sex-matched healthy controls, 20 control patients with depression and 22 control patients with rheumatoid arthritis. Samples were prepared using the published methods of McGregor et al. to produce heptafluorobutyryl-isobutyl derivatives of urinary metabolites. Alternative preparations utilised isopropyl, n-butyl and trifluoroacetyl derivatives. These were separated and identified using gas chromatography-mass spectrometry. CFSUM2 was identified as being partially derivatised [isobutyl ester-mono-heptafluorobutyryl (HFB)] serine. CFSUM1 was identified as partially derivatised pyroglutamic acid, being the isobutyl ester without formation of a HFB derivative. Both CFSUM1 and CFSUM2 are artefacts of the sample preparation procedure and previously reported quantitative abnormalities of CFSUM1 and CFSUM2 in urine from patients with ME/CFS are also artefactual. Pyroglutamic acid may be of primarily dietary origin. The methods used cannot provide reliable qualitative or quantitative data on urinary metabolites. No clinical or biochemical significance can be drawn between these compounds in ME/CFS or any other clinical conditions.

This study investigated the potential of a single administration of carrier erythrocyte entrapped antigen to elicit humoral responses in the Balb/c mouse. Humoral responses to primary immunizations of erythrocyte encapsulated antigens were compared with those obtained with adjuvanted antigen administered via the subcutaneous route. Ig isotype responses to primary immunizations of erythrocyte entrapped antigen and subcutaneous antigen were compared to responses observed in mice that subsequently received booster immunizations with un-entrapped antigen. This study demonstrates that a single administration of antigen-loaded carrier erythrocytes is able to elicit humoral immune responses comparable or superior to those obtained via the adjuvanted subcutaneous vaccination route. The IgG isotype profiles demonstrate that the erythrocyte entrapment of antigens is another mechanism by which the Th responses to antigens maybe modulated.

Glutaryl-CoA dehydrogenase (GCDH) deficiency is a rare inborn disorder of L-lysine, L-hydroxylysine, and L-tryptophan metabolism complicated by striatal damage during acute encephalopathic crises. Three decades after its description, the natural history and how to treat this disorder are still incompletely understood. To study which variables influenced the outcome, we conducted an international cross-sectional study in 35 metabolic centers. Our main outcome measures were onset and neurologic sequelae of acute encephalopathic crises. A total of 279 patients (160 male, 119 female) were included who were diagnosed clinically after clinical presentation (n = 218) or presymptomatically by neonatal screening (n = 23), high-risk screening (n = 24), or macrocephaly (n = 14). Most symptomatic patients (n = 185) had encephalopathic crises, characteristically resulting in bilateral striatal damage and dystonia, secondary complications, and reduced life expectancy. First crises usually occurred during infancy (95% by age 2 y); the oldest age at which a repeat crisis was reported was 70 mo. In a few patients, neurologic disease developed without a reported crisis. Differences in the diagnostic criteria and therapeutic protocols for patients with GCDH deficiency resulted in a huge variability in the outcome worldwide. Recursive partitioning demonstrated that timely diagnosis in neurologically asymptomatic patients followed by treatment with L-carnitine and a lysine-restricted diet was the best predictor of good outcome, whereas treatment efficacy was low in patients diagnosed after the onset of neurologic disease. Notably, the biochemical phenotype did not predict the clinical phenotype. Our study proves GCDH deficiency to be a treatable disorder and a good candidate for neonatal screening.

Previous work by others have suggested the occurrence of one or more chemical or metabolic ‘markers’ for ME/CFS including specific amino acids and organic acids and a number of unidentified compounds (CFSUM1, CFSUM2). We have shown elsewhere that CFSUM1 is partially derivatised pyroglutamic acid and CFSUM2 partially derivatised serine and have suggested and demonstrated that the analytical methods used were unsuitable to identify or to accurately quantify urinary metabolites. We have now made a detailed analysis of plasma and urinary amino acids and of urinary organic acids from patients with ME/CFS and from three control groups. Fasting blood plasma and timed urine samples were obtained from 31 patients with CFS, 31 age and sex-matched healthy controls, 15 patients with depression and 22 patients with rheumatoid arthritis. Plasma and urinary amino acids and urinary organic acids were determined using established and validated methods and data compared by statistical analysis. None of the previously reported abnormalities in urinary amino acids or of organic acids could be confirmed. Results however provide some evidence in patients with ME/CFS for underlying inflammatory disease and for reduced intramuscular collagen with a lowered threshold for muscle micro-injury. These factors in combination may provide a basis for the fatigue and muscle pain that are the major symptoms in these patients.

Previous reports of patients with 3-hydroxy-3-methylglutaric aciduria have described the occurrence of di-trimethylsilyl (TMS) and tri-TMS derivatives of 3-hydroxy-3-methylglutaric acid on analysis using gas chromatography and mass spectrometry, leading to difficulty in quantification and ambiguity in diagnosis. We have extracted organic acids from the urine of patients with 3-hydroxy-3-methylglutaric aciduria using a variety of procedures. Solvent extraction combined with hydrochloric acid/sodium chloride resulted in production of both di-TMS and tri-TMS derivatives of 3-hydroxy-3-methylglutaric acid and also mono-TMS and di-TMS derivatives of 3-hydroxyisovaleric acid. The effects were not abolished by heating. Use of sulphate-based reagents minimised artefact formation and use of DEAE-Sephadex anion exchange extraction resulted in single fully trimethylsilylated derivatives. Artefact formation during use of chloride-based reagents was abolished by pyridine added prior to trimethylsilylation. Chloride ions form adducts with hydroxyl groups in these 3-hydroxy-3-methyl carboxylic acids that prevent complete trimethylsilylation. Chloride-based reagents should be avoided in the solvent extraction of organic acids from physiological fluids or, if used, pre-treatment of the dried extract with pyridine is essential to avoid partial trimethylsilylation of 3-hydroxy-3-methyl carboxylic acids.

Fumarase deficiency is a rare autosomal recessive disorder of the citric acid cycle causing severe neurological impairment. The cDNA for both the rat and human enzymes has been cloned previously and shown to encode a coding region of 1.46 kb. To scan for mutations in fumarase-deficient patients we amplified the coding region of fumarase from fibroblast/lymphoblast cDNA employing the oligonucleotide primers designed from the published human and rat cDNA sequence. We then directly sequenced the polymerase chain reaction product. In seven unrelated patients, we detected four missense mutations (A265T, D383V, F269C, K187R), a nonsense mutation (W458X), a 3-bp AAA insertion that introduces an additional lysine residue at codon 435, and a spontaneous new mutation resulting in a 74-bp deletion (66del74). Seven at-risk pregnancies were monitored with one prenatal diagnosis of fumarase deficiency by molecular analysis and favorable outcome of the other pregnancies as predicted by enzyme assay of cultured fetal cells or molecular analysis.

We have shown marked increases in the plasma amino acid concentrations of very low birth weight (VLBW) infants treated with dexamethasone (Arch Dis Child 1992; 67: 5-9). Ornithine, citrulline, alanine and glutamine increased most. We now report rates of urinary excretion Methods: 24-hour urine collections in 6 VLBW infants before and after 48 hours of dexamethasone (0.6 mg kg−1 d−1). Amino acids were measured by high performance liguid chromatography (HPIC). Results: Median values given (n=6 unless indicated). Conclusion: Increased excretion of both the end product and intermediate compounds of the urea cycle support the suggestion that changes in plasma amino acid concentrations result from catabolism rather than inhibition of nitrogen disposal.

Conference Article| December 01 1983 Secondary carnitine insufficiency in disorders of organic acid metabolism: modulation of acyl-CoA/CoA ratios by l-carnitine in vivo RONALD A. CHALMERS; RONALD A. CHALMERS *Paediatric Research Group, M.R.C. Clinical Research Centre, Watford Road, Harrow Middx. HA1 3UJ, U.K. Search for other works by this author on: This Site PubMed Google Scholar CHARLES R. ROE; CHARLES R. ROE †Division of Pediatric Metabolism, Duke University Medical Center, Durham, NC 27710, U.S.A. Search for other works by this author on: This Site PubMed Google Scholar BERYL M. TRACEY; BERYL M. TRACEY *Paediatric Research Group, M.R.C. Clinical Research Centre, Watford Road, Harrow Middx. HA1 3UJ, U.K. Search for other works by this author on: This Site PubMed Google Scholar TERRY E. STACEY; TERRY E. STACEY *Paediatric Research Group, M.R.C. Clinical Research Centre, Watford Road, Harrow Middx. HA1 3UJ, U.K. Search for other works by this author on: This Site PubMed Google Scholar CHARLES L. HOPPEL; CHARLES L. HOPPEL ‡Veterans' Administration Medical Center, Departments of Pharmacology and Medicine, Case Western Reserve University School of Medicine, Cleveland, OH 44106, U.S.A. Search for other works by this author on: This Site PubMed Google Scholar DAVID S. MILLINGTON DAVID S. MILLINGTON †Division of Pediatric Metabolism, Duke University Medical Center, Durham, NC 27710, U.S.A. Search for other works by this author on: This Site PubMed Google Scholar Author and article information Publisher: Portland Press Ltd Online ISSN: 1470-8752 Print ISSN: 0300-5127 © 1983 Biochemical Society1983 Biochem Soc Trans (1983) 11 (6): 724–725. https://doi.org/10.1042/bst0110724 Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Facebook Twitter LinkedIn Email Cite Icon Cite Get Permissions Citation RONALD A. CHALMERS, CHARLES R. ROE, BERYL M. TRACEY, TERRY E. STACEY, CHARLES L. HOPPEL, DAVID S. MILLINGTON; Secondary carnitine insufficiency in disorders of organic acid metabolism: modulation of acyl-CoA/CoA ratios by l-carnitine in vivo. Biochem Soc Trans 1 December 1983; 11 (6): 724–725. doi: https://doi.org/10.1042/bst0110724 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll JournalsBiochemical Society Transactions Search Advanced Search This content is only available as a PDF. © 1983 Biochemical Society1983 Article PDF first page preview Close Modal You do not currently have access to this content.

Conference Article| October 01 1980 Species-specific characteristics of released erythrocyte ‘ghosts’ in vitro ULRICH SPRANDEL; ULRICH SPRANDEL * Search for other works by this author on: This Site PubMed Google Scholar ANTHONY R. HUBBARD; ANTHONY R. HUBBARD 1Division of Inherited Metabolic Diseases, M.R.C. Clinical Research Centre, Watford Road, Harrow, Middx. HA1 3UJ, U.K. Search for other works by this author on: This Site PubMed Google Scholar RONALD A. CHALMERS RONALD A. CHALMERS 1Division of Inherited Metabolic Diseases, M.R.C. Clinical Research Centre, Watford Road, Harrow, Middx. HA1 3UJ, U.K. Search for other works by this author on: This Site PubMed Google Scholar Author and article information Publisher: Portland Press Ltd Online ISSN: 1470-8752 Print ISSN: 0300-5127 © 1980 Biochemical Society1980 Biochem Soc Trans (1980) 8 (5): 536–537. https://doi.org/10.1042/bst0080536 Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Facebook Twitter LinkedIn Email Cite Icon Cite Get Permissions Citation ULRICH SPRANDEL, ANTHONY R. HUBBARD, RONALD A. CHALMERS; Species-specific characteristics of released erythrocyte ‘ghosts’ in vitro. Biochem Soc Trans 1 October 1980; 8 (5): 536–537. doi: https://doi.org/10.1042/bst0080536 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll JournalsBiochemical Society Transactions Search Advanced Search This content is only available as a PDF. © 1980 Biochemical Society1980 Article PDF first page preview Close Modal You do not currently have access to this content.

Conference Article| October 01 1980 Dependence of mouse erythrocyte ‘ghost’ survival in vivo on cellular ATP concentration ANTHONY R. HUBBARD; ANTHONY R. HUBBARD 1Division of Inherited Metabolic Diseases, M.R.C. Clinical Research Centre, Watford Road, Harrow, Middx. HA1 3UJ, U.K. Search for other works by this author on: This Site PubMed Google Scholar ULRICH SPRANDEL; ULRICH SPRANDEL 1Division of Inherited Metabolic Diseases, M.R.C. Clinical Research Centre, Watford Road, Harrow, Middx. HA1 3UJ, U.K. Search for other works by this author on: This Site PubMed Google Scholar RONALD A. CHALMERS RONALD A. CHALMERS 1Division of Inherited Metabolic Diseases, M.R.C. Clinical Research Centre, Watford Road, Harrow, Middx. HA1 3UJ, U.K. Search for other works by this author on: This Site PubMed Google Scholar Biochem Soc Trans (1980) 8 (5): 578. https://doi.org/10.1042/bst0080578 Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Facebook Twitter LinkedIn MailTo Cite Icon Cite Get Permissions Citation ANTHONY R. HUBBARD, ULRICH SPRANDEL, RONALD A. CHALMERS; Dependence of mouse erythrocyte ‘ghost’ survival in vivo on cellular ATP concentration. Biochem Soc Trans 1 October 1980; 8 (5): 578. doi: https://doi.org/10.1042/bst0080578 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll JournalsBiochemical Society Transactions Search Advanced Search This content is only available as a PDF. © 1980 Biochemical Society1980 Article PDF first page preview Close Modal You do not currently have access to this content.

Conference Article| February 01 1978 Dicarboxylic Aciduria as an Indicator of Defective β-Oxidation in Twin Siblings with a Vomiting Sickness and Hypoglycaemia Similar to Jamaican Vomiting Sickness RONALD A. CHALMERS; RONALD A. CHALMERS *Division of Inherited Metabolic Diseases, Medical Research Council Clinical Research Centre, Watford Road, Harrow, Middx. HA1 3UJ, U.K. Search for other works by this author on: This Site PubMed Google Scholar ALEXANDER M. LAWSON ALEXANDER M. LAWSON †Division of Clinical Chemistry, Medical Research Council Clinical Research Centre, Watford Road, Harrow, Middx. HA1 3UJ, U.K. Search for other works by this author on: This Site PubMed Google Scholar Biochem Soc Trans (1978) 6 (1): 111–113. https://doi.org/10.1042/bst0060111 Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Facebook Twitter LinkedIn Email Cite Icon Cite Get Permissions Citation RONALD A. CHALMERS, ALEXANDER M. LAWSON; Dicarboxylic Aciduria as an Indicator of Defective β-Oxidation in Twin Siblings with a Vomiting Sickness and Hypoglycaemia Similar to Jamaican Vomiting Sickness. Biochem Soc Trans 1 February 1978; 6 (1): 111–113. doi: https://doi.org/10.1042/bst0060111 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll JournalsBiochemical Society Transactions Search Advanced Search © 1978 Biochemical Society1978 Article PDF first page preview Close Modal You do not currently have access to this content.

Conference Article| February 01 1978 Identification of 5-Hydroxyhexanoic Acid in the Urine of Twin Siblings with a Syndrome having Close Similarities to Jamaican Vomiting Sickness ALEXANDER M. LAWSON; ALEXANDER M. LAWSON *Division of Clinical Chemistry, Medical Research Council Clinical Research Centre, Watford Road, Harrow, Middx. HA1 3UJ, U.K. Search for other works by this author on: This Site PubMed Google Scholar RONALD A. CHALMERS RONALD A. CHALMERS †Division of Inherited Metabolic Diseases, Medical Research Council Clinical Research Centre, Watford Road, Harrow, Middx. HA1 3UJ, U.K. Search for other works by this author on: This Site PubMed Google Scholar Author and article information Publisher: Portland Press Ltd Online ISSN: 1470-8752 Print ISSN: 0300-5127 © 1978 Biochemical Society1978 Biochem Soc Trans (1978) 6 (1): 108–110. https://doi.org/10.1042/bst0060108 Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Facebook Twitter LinkedIn Email Cite Icon Cite Get Permissions Citation ALEXANDER M. LAWSON, RONALD A. CHALMERS; Identification of 5-Hydroxyhexanoic Acid in the Urine of Twin Siblings with a Syndrome having Close Similarities to Jamaican Vomiting Sickness. Biochem Soc Trans 1 February 1978; 6 (1): 108–110. doi: https://doi.org/10.1042/bst0060108 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll JournalsBiochemical Society Transactions Search Advanced Search This content is only available as a PDF. © 1978 Biochemical Society1978 Article PDF first page preview Close Modal You do not currently have access to this content.

These studies have shown that the over-all losses observed are due to volatilisation during the freeze-drying process. These losses are related to the variation of the vapour or sublimation pressures of the acids with temperature, and are also related to their latent heats of vaporisation or sublimation.Reliable data on the latent heats of vaporisation and sublimation of the acids of interest are seldom available and a method for the estimation of the latent heats, based on group contributions, has been developed. The reliability of the method, which is generally applicable to organic compounds, is discussed.Thermochemical data derived from the use of this method have been used in conjunction with reliable published experimental data to determine the optimum freeze-drying conditions for the complete quantitative recovery of all but the most volatile of the acids studied, with a minimum of preliminary experimental work.

A method for the quantitative extraction and gas-liquid chromatographic determination of organic acids in aqueous solution and biological fluids has been developed. The acids are extracted by a DEAE-Sephadex anion-exchange column, neutral and basic compounds are removed by washing with water and the acids are eluted with a pyridinium acetate buffer. The ethoximes of oxo-acids are formed in the eluate to stabilise these compounds and the eluate is then freeze-dried under carefully controlled conditions. The residue of dry free acids and their pyridinium salts is trimethylsilylated and the trimethylsilyl derivatives are separated and quantitatively determined by gas-liquid chromatography with the use of internal standards. The method would not be suitable for the determination of formic, acetic, propionic or butyric acid because of their volatility.

The enzymatic spectrophotometric determination of oxypurines (hypoxanthine plus xanthine) in urine and blood plasma has been extended by the use of differential spectrophotometry at 280 and 292 nm to enable the separate determination of hypoxanthine and xanthine to be carried out. The method retains the high degree of accuracy and specificity of the determination of total oxypurines, and has shown good recoveries and reproducibility when applied to aqueous solutions and to urine. Although less precise when applied to plasma, the method is the only simple method at present available that enables the determination of hypoxanthine and xanthine to be carried out on this material.

A quantitative method for the determination of "oxypurines"(hypoxanthine plus xanthine) in the presence of relatively high concentrations of uric acid, as in urine and blood plasma, is described.The oxypurines are separated from the uric acid and, with plasma, from proteins, on a cation-exchange resin, eluted and oxidised enzymatically to uric acid by using xanthine oxidase (xanthine: oxygen oxidoreductase, E.C.1.2.3.2). The uric acid is then determined by the change in the value of E292, which occurs when it is oxidised to allantoin by the highly specific enzyme uricase (urate: oxygen oxidoreductase, E.C.1.7.3.3).The accuracy and reproducibility of the method have been evaluated and a comparison with other methods is included in the discussion.