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ABSTRACT Reinforced Concrete (RC) is the predominant and most frequently used building material with a worldwide annual material flow of approximately 20-25 billion tons. Consequently, cement as the most used [...]

Objective: To evaluate the efficacy of a treatment programme for patients with fibromyalgia (FM) based on self management, using pool exercises and education. Methods: Randomised controlled trial with a 6 [...]

Objectives: To examine the long term prognosis in patients with fibromyalgia (FM). Methods: Forty five of 70 patients who had participated in a three week trial six years earlier completed [...]

Isolated methylmalonic acidurias comprise a heterogeneous group of inborn errors of metabolism caused by defects of methylmalonyl-CoA mutase (MCM) (mut0, mut–) or deficient synthesis of its cofactor 5′-deoxyadenosylcobalamin (AdoCbl) (cblA, cblB). The aim of this study was to compare the long-term outcome in patients from these four enzymatic subgroups. Eighty-three patients with isolated methylmalonic acidurias (age 7–33 y) born between 1971 and 1997 were enzymatically characterized and prospectively followed to evaluate the long-term outcome (median follow-up period, 18 y). Patients with mut0(n42), mut−(n10), cblA (n20), and cblB (n11) defects were included into the study. Thirty patients (37%) died, and 26 patients survived with a severe or moderate neurologic handicap (31%), whereas 27 patients (32%) remained neurologically uncompromised. Chronic renal failure (CRF) was found most frequently in mut0(61%) and cblB patients (66%), and was predicted by the urinary excretion of methylmalonic acid (MMA) before CRF. Overall, patients with mut0and cblB defects had an earlier onset of symptoms, a higher frequency of complications and deaths, and a more pronounced urinary excretion of MMA than those with mut−and cblA defects. In addition, long-term outcome was dependent on the age cohort and cobalamin responsiveness.

Two siblings, a boy age 12 and his sister age 4 years, presented with proteinuria and hematuria, hypertension, and chronic hemolytic anemia. At age 13 years, the boy developed an episode of severe hypertensive encephalopathy and transient renal failure. Both children are attending normal school, have no neurologic symptoms, and only minimal pigmentary retinal abnormalities. Renal biopsy showed a chronic thrombotic microangiopathic nephropathy. Both patients had hyperhomocysteinemia and mild methylmalonic aciduria. Fibroblasts showed decreased cobalamin uptake, reduced methyl- and adenosyl-cobalamin formation, and deficient incorporation of formate and propionate, compatible with the Cbl-C complementation group, but milder than that found in cells from most patients. Both patients and their father carry a balanced reciprocal translocation. Parenteral hydroxycobalamin treatment reduced the homocysteine levels, and methylmalonic acid disappeared. Increasing the dosage of hydroxycobalamin from 1 to 2.5, then 5 mg daily together with betaine, further reduced homocysteine levels (boy from 118 to 23 μM and girl from 59 to 14 μM). With this treatment, hemolysis has stopped, hematuria has disappeared, proteinuria has almost normalized, and creatinine clearance has been stable. Investigations for chronic thrombotic microangiopathy should include testing for this unusual but treatable disorder, regardless of age of presentation. © 2002 Wiley-Liss, Inc.

We report the first case of isolated biotin resistant 3-methylcrotonyl-CoA carboxylase (MCC) deficiency in Argentina. The diagnosis was established at 14 months of age by urinary organic-acid analysis and confirmed by enzyme assay in fibroblasts. The patient suffered from severe psychomotor retardation, hypotonia, areflexia, and failure to thrive, and died unexpectedly at 3 years 4 months of life. Brain MRI at 14 months showed signals of the white matter on cerebral T2-weighted, which were indicative of confluent and multiple foci of leukodystrophy, a pattern not previously described in this entity. In addition, high levels of oxypurines were detected in cerebrospinal fluid. This might be related to energetic consequences of the enzyme deficiency in the brain. This case extends the phenotype of isolated MCC deficiency in infancy and suggests this entity should be considered to be one of the possible causes of “metabolic leukodystrophies.”

Abstract: Holocarboxylase synthetase deficiency (HCS) is an autosomal recessive disorder characterized by metabolic ketoacidosis, abnormal urine organic metabolites, and dermatitis. These symptoms are improved by pharmacological doses of biotin. In this study, we have analyzed seven patients with HCS deficiency found in European and Middle Eastern countries by using reverse transcription/polymerase chain reaction/single-stranded conformation polymorphism and a sequencing analysis. Although we had previously reported that two mutations were frequent in Japanese patients, no frequent mutations were found in the patients analyzed in this study. Seven novel mutations were identified in the cDNA of the patients; these included three missense mutations, two single-base deletions that resulted in a termination codon, a three-base in-frame deletion, and a 68-bp deletion. A new polymorphism C1121T was also identified in four alleles. A transient expression study demonstrated that the HCS activities of three missense mutations and one amino acid deletion were 1%–14% that of wild-type cDNA; in contrast, the activities of the two single-base deletions followed by a termination codon and Asp571Asn were nearly undetectable. These data suggest that a variety of mutations is responsible for decreasing HCS activity and that the aspartate residue at amino acid position 571 may be crucial for the catalytic activity of HCS.

Inability to recycle biotin from endogenous biocytin in congenital biotinidase deficiency is associated with increased requirement of exogenous free biotin. We have observed that severe biotin depletion with clinical and biochemical consequences occurs within 12 days after birth in a newborn patient and within 15–20 days after withdrawal of biotin supplementation in four other patients. Our studies have shown that:Urinary loss of biotin and biocytin are major causes for this rapid biotin depletion.Intestinal absorption of biotin seems to be normal at least at the loading dose of 1.5 µg/kg.At normal or subnormal plasma biotin concentrations biocytin is found in low concentrations (below 1 nmoll-1) in plasma of patients but at much higher concentrations in urine (100–600 nmoll-1).An oral load of biocytin results in patients in unchanged biotin levels but in a marked rise of biocytin in plasma followed by rapid renal excretion of biocytin whereas in controls biotin levels in plasma increase rapidly and biocytin remains below detection levels. Urinary loss of biotin and biocytin are major causes for this rapid biotin depletion. Intestinal absorption of biotin seems to be normal at least at the loading dose of 1.5 µg/kg. At normal or subnormal plasma biotin concentrations biocytin is found in low concentrations (below 1 nmoll-1) in plasma of patients but at much higher concentrations in urine (100–600 nmoll-1). An oral load of biocytin results in patients in unchanged biotin levels but in a marked rise of biocytin in plasma followed by rapid renal excretion of biocytin whereas in controls biotin levels in plasma increase rapidly and biocytin remains below detection levels.

We present a new case of holocarboxylase synthetase (HCS) deficiency, a rare autosomal recessive metabolic disorder, causing the “early-onset” form of multiple carboxylase deficiency. The patient was born at term of healthy consanguineous parents after an uncomplicated pregnancy. On the 2nd day of life she refused oral feeding, became tachydyspnoeic and showed excessive weight loss. Laboratory studies showed metabolic acidosis, marked lactic acidaemia, hyperammonaemia and increased urinary excretion of 3-hydroxyisovaleric acid, 3-methylcrotonyglycine, 3-hydroxypropionic acid and methylcritric acid. Peritoneal dialysis combined with oral supplementation of biotin (10 mg/day) started on the 3rd day of life resulted in rapid clinical recovery and normalisation of biochemical parameters. HCS deficiency was established in lymphocytes and skin fibroblasts. The activities of all biotin-dependent carboxylases were severely decreased in fibroblasts grown in medium with moderate biotin concentration (10−8 mol/l) but normal in a high biotin medium (10−5 mol/l). Mitochondrial carboxylase activities in lymphocytes were 23%–29% of mean normal during therapy with 20 mg of biotin/day, with the higher dose of 40 mg/day they were within (3-methylcrotoryl-CoA carboxylase, pyruvate carboxylase) or slightly below (propionyl-CoA carboxylase) the normal range. At the age of 3 years the patient's physical and psychomotor development are normal. Early biotin supplementation should be considered in newborns with lactic acidosis and organoaciduria until a final diagnosis has been established. Furthermore, the required individual dose of biotin has to be carefully evaluated biochemically for the individual patient.

Comprehensive data on 30 patients with propionic acidaemia, diagnosed by selective screening for inborn errors of metabolism, are presented. The most valuable diagnostic metabolites found were methylcitric-, 3-hydroxypropionic-, and 2-methyl-3-oxovaleric acids. Hyperlysinaemia and hyperlysinuria are also characteristic findings in this disease. The metabolic pattern found in propionic acidaemia is discussed extensively as are enzymatic findings. Residual activity of propionyl-CoA carboxylase is neither a predictive marker for severity nor for outcome of the disease. Propionate fixation assay were less reliable for confirmation of propionic acidaemia and of no prognostic value. Clinical presentation of the disease is discussed in detail. Besides the well-known unspecific findings (poor appetite, feeding difficulties, vomiting, dehydration, weight loss, muscular hypotonia, dyspnoea, somnolence, apathy, convulsion, coma, severe metabolic acidosis, hyperammonaemia) various skin abnormalities have been detected in about 50% of all patients. In 27% “dermatitis acidemica” was found.

We have investigated four patients from three unrelated families with typical clinical and biochemical features of “late-onset” multiple carboxylase deficiency. All patients suffered from biotinidase deficiency (plasma biotinidase activities 1.4%–3% of normal). Intestinal absorption of biotin, measured in three of the patients using a single load of 1.5 µg/kg, was found to be normal. Deficient activities of the mitochondrial biotin-dependent carboxylases in lymphocytes of one of these patients increased from 25% of mean basal control values to 33%–36% within 45 min and to 46%–47% within 2 h of the 1.5 µg/kg biotin load. After a high biotin load of 100 µg/kg, the values normalised within 45 min in all three patients studied. These results indicate normal cellular transport of biotin and normal holocarboxylase synthesis. After cessation of biotin supplementation, the plasma and urinary biotin in patients decreased to subnormal levels. In one patient, available for more detailed studies, both plasma and urinary biotin declined about twice as fast as in controls (apparent half-life 12–14 h in the patient and 26 h in controls). These results point to increased excretion of free biotin in our patient. Renal loss of biotin is one of the factors contributing to the high biotin requirement observed in patients with biotinidase deficiency.

A modified assay for the detection of DNA single-strand breaks (SSBs) in human mononucleated white blood cells (MWBCs) based on the nick translation (NT) reaction was developed and combined with the test for unscheduled DNA synthesis (UDS). Both assays were performed on disposable 96-well filtration plates and therefore allowed rapid and sensitive examination of SSBs and UDS. Only 5–8 ml of heparinized blood is required for an eightfold determination in both assays. The uptake of radioactive nucleotide precursors was demonstrated to depend linearly upon the NT reaction time and in both assay systems on the number of investigated cells. The best results and the lowest signal to noise ratio were obtained when the NT assay was performed at 25°C for 20 min. The test was standardized for 150000MWBCs/well and a polymerase I concentration of 20 U/ml. The same number of cells were used to measure UDS during a 4-h incubation at 37°C. We observed a dose-dependent increase in SSBs after in vitro incubation with N-methyl-N-nitrosoguanidine (MNNG), with a detection limit of 50 µM when MNNG was present for 1 h and of 5µM after 20-h incubation period. UDS in MWBCs was increased after treatment for 1 h with MNNG (200 µM) only if poly(ADP)ribose synthesis was inhibited by 3-aminobenzamide. UDS was induced by 320 µM methyl methanesulfonate, but SSBs could only be detected after inhibition of UDS by 100 µM hydroxyurea. The described modification of the NT procedure for the detection of SSBs in DNA of human MWBCs and its combination with the detection of UDS could serve as a useful tool for biological monitoring in occupational or environmental medicine.

Children with biotinidase deficiency usually exhibit symptoms at several months to years of age. We describe four children who had symptoms later in childhood or during adolescence; they had motor limb weakness, spastic paresis, and eye problems, such as loss of visual acuity and scotomata, rather than the more characteristic symptoms observed in young untreated children with the disorder. These older children each have different mutations, but they are the same as those of children who have exhibited symptoms at an early age. Biotinidase deficiency should be considered in older children who suddenly experience limb weakness and/or spastic paresis and eye symptoms. (J Pediatr 1998;132:362-5)

An unusual clinical course of a patient with biotinidase deficiency, causing Leigh syndrome, is reported. Laryngeal stridor was the major presenting symptom followed by progressive neurologic deterioration and death at the age of 21.5 mo. Absence of skin and hair abnormalities as well as of organic aciduria delayed the correct diagnosis. Necropsy revealed subacute necrotizing encephalopathy (Leigh syndrome). Carboxylase activities (propionyl CoA carboxylase, 3-methylcrotonyl-CoA carboxylase, pyruvate carboxylase) measured in lymphocytes 1 day before death were decreased to 10 of normal values. Propionyl-CoA carboxylase was shown to be the only stable carboxylase in human postmortem tissue; in our patient it was moderately decreased in postmortem liver (29 of control) and kidney (42), but severely decreased in brain (3). These findings might explain the severity of neurological symptoms in the absence of marked organic aciduria. They indicate that in biotinidase deficiency the CNS may become biotin depleted earlier and more severely than other organs. Biotinidase deficiency should be included in the differential diagnosis of Leigh syndrome and of unexplained respiratory problems.

We have investigated the molecular lesions of T-protein deficiency causing typical or atypical nonketotic hyperglycinemia (NKH) in two unrelated pedigrees. A patient with typical NKH was identified as being homozygous for a missense mutation in the T-protein gene, a G-to-A transition leading to a Gly-to-Asp substitution at amino acid 269 (G269D). Sibling patients of a second family with atypical NKH had two different missense mutations in the T-protein gene (compound heterozygote), a G-to-A transition leading to a Gly-to-Arg substitution at amino acid 47 (G47R) in one allele, and a G-to-A transition leading to an Arg-to-His substitution at amino acid 320 (R320H) in the other allele. Gly 269 is conserved in T-proteins of various species, even in E. coli, whereas Gly 47 and Arg 320 are replaced by Ala and Leu, respectively, in E. coli. The mutation occurring in more conservative amino acid residues thus results in more deleterious damage to the T-protein, and gives the severe clinical phenotype, viz., typical NKH.

ABSTRACT: An unusual clinical course of a patient with biotinidase deficiency, causing Leigh syndrome, is reported. Laryngeal stridor was the major presenting symptom followed by progressive neurologic deterioration and death at the age of 21.5 mo. Absence of skin and hair abnormalities as well as of organic aciduria delayed the correct diagnosis. Necropsy revealed subacute necrotizing encephalopathy (Leigh syndrome). Carboxylase activities (propionyl CoA carboxylase, 3-methylcrotonyl-CoA carboxylase, pyruvate carboxylase) measured in lymphocytes 1 day before death were decreased to 10% of normal values. Propionyl-CoA carboxylase was shown to be the only stable carboxylase in human postmortem tissue; in our patient it was moderately decreased in postmortem liver (29% of control) and kidney (42%), but severely decreased in brain (3%). These findings might explain the severity of neurological symptoms in the absence of marked organic aciduria. They indicate that in biotinidase deficiency the CNS may become biotin depleted earlier and more severely than other organs. Biotinidase deficiency should be included in the differential diagnosis of Leigh syndrome and of unexplained respiratory problems.

ABSTRACT: Folic acid coenzyme distribution patterns were examined in the liver and kidney of two patients with homocystinuria due to different inborn errors of metabolism affecting the remethylation of homocysteine to methionine. One patient, with severe mental retardation (and death at 3½ yr), had greatly reduced levels of methylenetetrahydrofolic acid (THF) reductase in fibroblasts as well as in liver and kidney. Chromatographic separation of folate coenzymes in liver showed an abnormal pattern with THF as the main component and almost no methyl-THF but total folate was normal. The other patient, who was dystrophic, microcephalic, and had megaloblastic anemia died at age 4 months. He had reduced levels of methionine synthetase in liver and kidney due to a defect of intracellular cobalamin metabolism. Chromatographic analysis of his tissues showed methyl-THF to be the principal principal folate form and a markedly reduced total folate. These results support the “methyl-THF trap” hypothesis and offer information with respect to the possible therapy of these two disorders.

Extract: Propionyl-CoA carboxylase and combined methylmalonyl-CoA (MMA-CoA) racemase and -mutase activities were studied in liver and fibroblasts of two patients with the acute neonatal form of nonketotic hyperglycemia. In all experiments, these enzyme activities studied in tissues of the patients were within the range of healthy control subjects, whereas no propionyl-CoA carboxylase activity was measurable in the fibroblasts of a patient with propionic acidemia. Subcellular fractionation of liver and fibroblasts indicated that the normal amounts of MMA-CoA found after incubation of whole tissue homogenate were formed by propionyl-CoA carboxylase, a mitochondrial enzyme, and not by acetyl-CoA carboxylase, which theoretically could also be involved in the carboxylation of propionyl-CoA.From the above data as well as from clinical and biochemical observations in three patients, it was concluded that there exists a true nonketotic hyperglycinemia which is not related etiologically to the different disorders of the ketotic hyperglycinemia syndrome. True nonketotic hyperglycinemia is not associated with ketoacidosis even after loading with propionate- and MMA precursors. It must be distinguished by exclusion from mild forms of the ketotic hyperglycinemia syndrome which may present clinically as hyperglycinemia without ketosis.Speculation: The metabolism of propionate, methylmalonate, and branched chain amino acids is normal in true nonketotic hyperglycinemia. Further investigations will have to show whether the observed block in the glycine cleavage reaction to CO2, NH3, and a single-carbon tetrahydrofolate derivative represents the primary enzymatic defect. In view of the four enzymatic steps involved in this complex reaction, it may well be that true nonketotic hyperglycinemia also represents a heterogeneous syndrome. The elevated glycine concentrations in the central nervous system (CNS) may play a significant role in the development of the neurologic symptoms.

A computer program is described which allows the comparison of sample peaks with those of a standard. The errors produced by the chromatograph due to instability of inlet pressure or temperature are corrected by a consecutive adaption of time-windows of standard peaks. This method makes it possible to keep the time-windows for peak identification very small and to eliminate double identifications to a great extent. Quantitative analysis follows peak identification. Each sample peak has to pass a Nalimov test. A comparison of peak areas is finally used to establish a quantitative relation between sample and standard.

Renal reabsorption of biotin was investigated in human kidney by means of the isolated brush-border membrane vesicle technique. Biotin uptake into the vesicles was sodium-dependent producing a typical overshoot when incubated under sodium-gradient conditions (external concentration greater than internal). This effect was not observed in the presence of gradients of KCl, LiCl or choline-chloride, nor in the absence of any salt. Using the K+/valinomycin voltage-clamp method biotin uptake remained uninfluenced, i.e. was electroneutral, whereas glucose uptake (which is known to be electrogenic in kidney of other species) was greatly increased. When biotin transport was investigated as a function of external sodium concentration a stoichiometic coupling factor of 1 for the Na+-biotin- cotransport was determined. Increasing the biotin concentration in the incubation medium up to 200 µmol/l led to saturation with the kinetic parameters of 31 µmol/l for the apparent Michaelis constant and 82 nmol g protein-1 30 s-1 for the maximal transport rate. Uptake was not saturable in the concentration range of 0.001–1 µmol/l. Inhibition of the biotin uptake (25 µmol/l) was observed in the presence of 250 µmol/l dethiobiotin, bisnorbiotin, thioctic acid, and probenecid, whereas biocytin, propionic acid, lactic acid, succinic acid, citric acid, ascorbic acid, primidone and carbamazepine had no effect. We conclude that renal biotin reabsorption in human kidney is specifically sodium-dependent, saturable and electroneutral. It therefore fulfills the requirements for a secondary active carrier-mediated transport system. The results suggest that biocytin is not an inhibitor of renal biotin reabsorption.

Summary: We describe a simple method for the detection of biotinidaseK m-variants and detailed biochemical investigations in 5 such patient. They were detected among 103 patients with plasma biotinidase activity which ranged from undetectable to 30% of the mean normal value. Two different types of biotinidaseK m-variants were found. (1) In 3 infants biotinidase had a single 105–430-fold elevatedK m for biocytin. Biotinidase showed very low activities (0.2–4% of the mean normal value) in the routine colorimetric assay and was not functionalin vivo. Accordingly, these patients presented with classical clinical illness. (2) In two patients biotinidase showed biphasic kinetics indicating the presence of one component with a normalK m and reducedV max (1.7% and 12%), and another with 330- and 59-fold elevatedK m, respectively. In these two patients, biotinidase proved to be at least partially functionalin vivo. However, the first patient developed severe symptoms and biotin deficiency late, at the age of 10–15 years, and the second had marginal biotin deficiency at the age of 2 years but no clinical symptoms. Comparative studies revealed that both patients had more severe biotin deficiency than age-matched patients with similar levels of residual biotinidase activity and a single normalK m. Therefore, all patients with residual biotinidase activity should be evaluated for the presence of aK m-mutation, since such patients should be treated with biotin. These can easily be detected by including a second substrate concentration (1.5 mmol/L) in the routine colorimetric biotinidase assay which is performed with 0.15 mmol/L biotin. Increased activity with the higher substrate concentration indicates the presence of aK m-mutation. Detailed kinetic studies are needed to evaluate the distinct forms ofK m-variants.

Summary 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.

A patient with early-onset 3-methylcrotonyl coenzyme A carboxylase (MCC) deficiency showing a severe clinical course is described. Abnormal eye and head movements suggestive of seizures were noticed soon after birth. Tonic convulsions at the age of 10 weeks led to admission. Urinary organic acid analysis using gas chromatography-mass spectrometry at 3 months of age revealed elevated concentrations of 3-hydroxyisovaleric acid (3HIVA) and 3-methylcrotonylglycine but normal levels of lactate, 3-hydroxypropionate and methylcitrate suggesting isolated MCC deficiency. This was confirmed by enzyme assays in lymphocytes and cultured skin fibroblasts: MCC activity was virtually undetectable whereas activities of propionyl-CoA and pyruvate carboxylases were within the normal range. A low protein (0.8–1.5 g/kg/day) diet supplemented with a leucine-free amino acid mixture resulted in a marked decrease of 3HIVA excretion.l-Carnitine and biotin administration had no effect on the clinical condition or metabolite exretion. Supplementation with glycine resulted in only a temporary fall of 3HIVA excretion and was therefore discontinued.l-Carnitine therapy was reintroduced later because of secondary carnitine deficiency. Compliance with treatment was poor until the age of 27 months resulting in a severe episode with seizures and coma. The general clinical condition of the patient was always good but his psychomotor development was delayed and seizures were not continuously under good control due to poor therapy compliance. The boy is now 10.5 years old and attending a school for children with learning handicaps.

We describe a simple method for the detection of biotinidaseKm-variants and detailed biochemical investigations in 5 such patient. They were detected among 103 patients with plasma biotinidase activity which ranged from undetectable to 30% of the mean normal value. Two different types of biotinidaseKm-variants were found. (1) In 3 infants biotinidase had a single 105–430-fold elevatedKmfor biocytin. Biotinidase showed very low activities (0.2–4% of the mean normal value) in the routine colorimetric assay and was not functionalin vivo. Accordingly, these patients presented with classical clinical illness. (2) In two patients biotinidase showed biphasic kinetics indicating the presence of one component with a normalKmand reducedVmax(1.7% and 12%), and another with 330- and 59-fold elevatedKm, respectively. In these two patients, biotinidase proved to be at least partially functionalin vivo. However, the first patient developed severe symptoms and biotin deficiency late, at the age of 10–15 years, and the second had marginal biotin deficiency at the age of 2 years but no clinical symptoms. Comparative studies revealed that both patients had more severe biotin deficiency than age-matched patients with similar levels of residual biotinidase activity and a single normalKm. Therefore, all patients with residual biotinidase activity should be evaluated for the presence of aKm-mutation, since such patients should be treated with biotin. These can easily be detected by including a second substrate concentration (1.5 mmol/L) in the routine colorimetric biotinidase assay which is performed with 0.15 mmol/L biotin. Increased activity with the higher substrate concentration indicates the presence of aKm-mutation. Detailed kinetic studies are needed to evaluate the distinct forms ofKm-variants.

This paper summarizes the result of an industry survey of gas insulated equipment protection practices and develops recommendations where necessary. Tables are included to show the type of gas insulated equipment located at each substation (current transformers, voltage transformers, switches, bus bars, bushings, lightning arresters, and cable end terminations), the equipment configuration (single or three conductors), the type of gas monitoring equipment used (density or pressure), the use of gas monitoring equipment (alarm and/or trip), unique relaying protection applications, and unique operating procedures. Gas insulated circuit breakers are specifically excluded from this survey.

Folic acid coenzyme distribution patterns were examined in the liver and kidney of two patients with homocystinuria due to different inborn errors of metabolism affecting the remethylation of homocysteine to methionine. One patient, with severe mental retardation (and death at 3 12 yr), had greatly reduced levels of methylenetetrahydrofolic acid (THF) reductase in fibroblasts as well as in liver and kidney. Chromatographic separation of folate coenzymes in liver showed an abnormal pattern with THF as the main component and almost no methyl-THF but total folate was normal. The other patient, who was dystrophic, microcephalic, and had megaloblastic anemia died at age 4 months. He had reduced levels of methionine synthetase in liver and kidney due to a defect of intracellular cobalamin metabolism. Chromatographic analysis of his tissues showed methyl-THF to be the principal principal folate form and a markedly reduced total folate. These results support the “methyl-THF trap” hypothesis and offer information with respect to the possible therapy of these two disorders

In a controlled study, ten male volunteers (five smokers and five nonsmokers) were subjected to different smoking conditions and compared to five non-smokers, not exposed to cigarette smoke. During the 4 days of the study, nonsmoking periods were strictly controlled. On the first day the ten subjects were sham exposed. On the second day the five smokers smoked 24 cigarettes in 8 h, while the five nonsmokers were exposed to the environmental tobacco smoke. After another day of sham exposure the smoke exposure was repeated under the same conditions. Blood was drawn before and after exposure and DNA single-strand breaks (SSBs) were analyzed in lymphocytes immediately (1 h) after isolation of cells and after 4 h incubation at 37°C, using a modified assay based on the nick translation reaction. Base levels of unscheduled DNA synthesis (UDS) and UDS levels were determined after 1 h incubation with methyl methanesulfonate. Duplicate analysis using the same method was performed in a second laboratory after transportation of blood samples at 0°C on a train from Munich to Hamburg. Tobacco smoke exposure of the subjects increased COHb and plasma cotinine levels. SSBs could be detected in all probands with some inter-individual day-to-day and morning-to-evening variations. In four of five active smokers, SSB increases were found after smoking. In nonsmokers exposed to tobacco smoke no exposure-related variation in SSB levels could be detected. In lymphocytes which were incubated in culture medium (DME/H) for 4 h at 37°C, SSBs correlated significantly with the SSBs of fresh (NT1) samples but the SSB level was lower in almost all cases and the effect of smoking was not as pronounced as in the NT1 samples. Larger interindividual variations and higher values in general were detected after 8–9h of transportation. Therefore, we recommend immediate determination of SSBs as soon as possible after blood sampling. We conclude that the modified nick translation assay is sensitive enough to detect SSBs caused by an in vivo genotoxic exposure when possible interindividual differences are considered in the study design and could therefore be used in biological monitoring of exposures at the workplace.

Tuberculosis of the clavicle has rarely been reported. We have been closely observing such a case in the past year and have made a rather careful search of the cases reported. Recently Macey1 at the Mayo Clinic briefly reported a case of tuberculosis of the left clavicle and right malar bone, both of which are infrequently seen; Coley2 reported a case about forty years ago. We have seen no other American reports. There have been twenty-one cases reported in the French literature that we have seen. Couillard-Labonette3 in 1898 gave a review of the literature in which he stated that LeDentu,4 Reverdin5 and Thierry6 had reported cases.We have included these cases in our report. Couillard also added three new cases of his own. Conor7 reviewed the literature and, besides quoting the cases cited by Couillard, made reference to a case reported by

Because of some recent papers suggesting, and in some cases even stating, that tropical sprue and pernicious anemia are the same disease, it has seemed worth while to give some of our observations on cases of sprue, especially comparing those that are typical of the latter condition. The identity of these two diseases has been particularly insisted on by Wood,1 who has accepted Ashford's theory that Monilia causes sprue, and who has been able to take cultures of this yeast in all of his recent cases of pernicious anemia. He quite rightly says that for those who believe Monilia psilosis is the cause of sprue, the finding of this organism in pernicious anemia is one more point tending to prove the identity of these two diseases. We have recently published our results2 with mouth and stool cultures in eleven cases of sprue and seventeen cases of pernicious anemia. Recently also

Meningitis due to the B. typhosus is a relatively rare disease. Cole collected the cases recorded up to 1904. We have been able to find twenty-three cases recorded in the literature since that time.In addition to reviewing the cases reported by Cole, we wish to report a case in which cholecystitis and otitis media were additional complications. We had the opportunity of doing a necropsy in this case, thus making an anatomic study of the complications possible. The findings of the meningeal complication and of a pure typhoid culture comply with all of Cole's requirements for the diagnosis of purulent meningitis. REPORT OF CASE CASE 3494. —R. A., aged 6, admitted to the Halstead Hospital, Oct. 12, 1919, with complaint of headache, fever and abdominal pain. FAMILY HISTORY. —Negative. One brother living and well. The brother later developed typhoid fever and was a patient in the hospital. Positive Widal;

In this report, attention will be called particularly to primary cancer of the lungs. However, for the purpose of discussing certain references to probable determining etiologic factors, attention will also be called to the cases of secondary carcinoma which occurred in our experience during the same time that the primary cases occurred.Carcinoma of the lungs in the most recent studies shows a much higher incidence than was formerly thought. It has come to be recognized as occurring comparatively frequently; so much so that in the consideration of diseases of the chest, especially of the chronic form, one should always hold in mind the possibility of primary carcinoma of the lungs.Various causes have been suggested to explain this remarkable increase. As yet there is no agreement among clinicians and laboratory men. The accumulated evidence of many case reports may help to clarify the matter, and this is our reason

Reports on the incidence of intestinal protozoa have appeared from time to time and from various parts of the country, but so far as we know there have not appeared recently any extensive studies from New York State.Through the cooperation of the superintendent and his staff we were able to obtain stool specimens from 1,122 inmates of a New York State school for feebleminded women, and it is the result of these examinations that we report.The great majority of the inmates were of the poorer class, all were below normal mentally, all were females, and all were confined in an institution where many of the inmates themselves are employed in the capacity of servants for the others. These people form a group in which a high rate of infestation of intestinal protozoa would not be considered remarkable. The fact that the rate is comparatively low, especially so far

Trilithiumhexaoxocyclotrithiazane* (trilithiumtrisulfimid) has been prepared for the first time by reaction of triammoniumtrisulfimid with LiOH in a solid state reaction and by using high boiling alcohols as reaction medium. The thermolysis of different salts of trisulfimid (Na-, K-, Li-, Ag-, NH4-salt) has been studied by thermoanalytical methods in the region between 25–500 dC. The course of decomposition of these compounds is discussed by IR and chromatographic measurements.

Congestion of blood vessels and marked edema may occur in rabbits with a severe leucopenia. These two phenomena are, therefore, independent of the leucocytes.

According to Osler, it is difficult to classify sprue, as various views of its etiology are held. It is a disease of tropical or subtropical countries, more often occurring in the newcomer and in the better class of people. The disease is characterized by a distinctive sore tongue and mouth, a peculiar type of diarrhea, marked anemia, loss of weight and a tendency to remissions and exacerbations. Its etiology is unknown; various theories are given, some of which are pancreatic disease, mold, infection with Monilia or bacteria or deficiency in fat.In this paper we shall deal more especially with the study of sprue as we have found it in thirty-six patients who have entered our clinic in the past five and one-half years. Most of these patients were missionaries, and most of them came from the Orient. There were sixteen patients from China, seven from India, five from Korea,

Recently Schoonmaker and Webb1 reported a case of auricular fibrillation in a toxic adenoma of the thyroid. Because of the great improvement noted in all symptoms in this case and the rarity of this condition among our patients with goiter we thought it worth while to investigate the literature on this subject.In looking through the literature we find that as yet not many cases have been reported in detail, and that as a rule there are only incidental references to cases of goiter in descriptions of various cardiac conditions. However, that auricular fibrillation is not rare in goiter is shown by Willius2 who stated that at the Mayo clinic 7 per cent. of patients with exophthalmic goiter and 9 per cent. with hyperactive adenoma have auricular fibrillation on admission, and that these figures were doubled while the patients were under observation. Willius and Boothby3 in a more recent paper,

Screening for biotinidase deficiency has been added recently to some national screening programmes. To clarify the problem of false-positive screening tests in premature infants, we have studied biotinidase activities in the plasma of this population in more detail. In 64 newborns (premature and term babies) biotinidase activities correlated positively with gestational age from the 2nd to the 30th day of life. During the 1st–3rd day the activities were below the normal adult range in all 64 infants. In 56 infants the activities subsequently increased gradually and reached the normal adult range during the 4th–40th day of life. In contrast, the biotinidase activities in eight preterm infants dropped during the 3rd–7th day of life. Impaired liver function as a possible cause for this finding could be ruled out in these infants. The lowest activities in these infants were measured during the 4th–6th day of life, i.e. unfortunately at a time when samples for the screening are normally taken. According to our data, 4–8 out of 48 preterm or small-for-date infants with biotinidase activities ranging from 4.7%–26% of the mean adult value would have given false-positive screening tests. A positive screening test was also obtained in a newborn and in an older unrelated child with a partial biotinidase deficiency. In these children the biotinidase activity did not rise but remained slightly below or at the lower range for heterozygotes (at 31% and 38% of the mean adult value). Currently we do not know whether such individuals are heterozygotes, or whether they have a variant of biotinidase deficiency. However, these children have developed normally without biotin therapy.

In a patient with methylmalonic acidaemia (MMAA), persistent neurological symptoms were observed in addition to the acute episodes of metabolic dysequilibrium. CT scan and magnetic resonance imaging revealed bilateral symmetrical necrosis of the globus pallidus. Different episodes of metabolic decompensation, one with severe acidosis, had occurred. Persistent neurological symptoms in patients with MMAA who are appropriately treated suggest irreversible brain damage which appears to occur preferentially at the level of the basal ganglia.

The human gene encoding the a-polypeptide of propionyl-CoA carboxylase (PCC) has hitherto been localized to the distal half of the long arm of chromosome 13, segment 13q22?q34. We studied the enzyme activities of mitochondrial carboxylases in cell cultures obtained from patients with different deletions of chromosome 13. By setting the PCC activity in normal diploid cell cultures (control group) at 100%, cell cultures with trisomy 13 showed 150% activity. In contrast, one of four patients with partial monosomy 13 had an enzyme activity of only 50%. Thus, by comparative deletion mapping, combined with studies of the gene-dosage effect, we have been able to assign the PCCA gene locus to chromosome band 13q32.