Yeast mediates lactic acidosis suppression after antibiotic cocktail treatment in short small bowel?

During acidotic periods in a girl with a short small bowel, very high D-lactic acid concentrations were measured in blood and urine; the patient's characteristic faecal flora contained mainly lactobacilli, and during antibiotic cocktail treatment also many yeasts. In this case report we sought to understand the beneficial effect of the antibiotic cocktail. Microbiological analysis was performed in faecal samples. Total lactic acid in serum and urine was studied using capillary gas chromatography-mass spectrometry, and D- and L-lactic acid in serum and urine by enzymatic assay. The results were coupled to patient's condition. Antibiotic cocktail therapy reduced the acidosis-associated symptoms, faecal lactobacilli and D-lactic acid production, but simultaneously the antibiotic therapy strongly increased the percentage of yeast in the faecal flora. Four to six weeks after each course of treatment the percentage of yeast decreased, whereas the percentage of intestinal lactobacilli increased; D-lactic acid also simultaneously increased in blood and urine. The patient felt well and showed a high percentage of intestinal yeast, but she often suffered from acidosis owing to a high percentage of lactobacilli. The yeast was identified as the pathogenic Candida glabrata. From the mentioned data together with data from the literature it was concluded that during several weeks the selected pathogenic yeast, C. glabrata, acted as a microbiological and metabolic buffer. Shortly after the course of antibiotic treatment this intestinal yeast strongly competed with the intestinal lactobacilli and thus prevented renewed rapid growth, massive D-lactic acid production from glucose and consequently also D-lactic acid-associated acidosis. The emergence of this yeast led us to consider probiotic lactobacilli or yeast for therapeutic use. The lack of knowledge regarding bile acid-deconjugating activity in both lactobacilli and probiotic yeast means that a final recommendation is not yet possible.

Trichothiodystrophy: quantification of cysteine in human hair and nails by application of sodium azide-dependent oxidation to cysteic acid

The term "trichothiodystrophy" (TTD) covers several autosomal recessive diseases whose diagnostic hallmark is short, brittle hair low in sulfur and cystine because of impaired synthesis of high-sulfur matrix protein. Clinical symptoms associated with TTD represent a variable range of abnormalities in organs derived from ectoderm and neuroectoderm. Important laboratory tests of the hair for the diagnosis of TTD comprise polarizing microscopy ("tiger-tail" pattern), electron microscopy, and amino acids analysis of hydrolyzed hair with a special focus on cystine. However, only very few institutions determine the amino acid composition of human hair and nail clippings, which requires special sample preparation including hydrolysis. If no special precautions are taken, quantification of cysteine and cystine becomes inaccurate because of decomposition of these residues during hydrolysis. We therefore performed the sample work-up with azide-dependent oxidation which we have for the first time adapted for analysis of hair and nail clippings. With our control and parent data resembling published data on hair and nail samples, we obtained a decreased proportion of cysteine (half cystine, determined as cysteic acid) in materials obtained from a boy with TTD. Clearly, the method for the quantification of cysteine following sodium azide-dependent oxidation is a suitable and rather convenient approach to the quantification of cyst(e)ine and other amino acids in hair and nail proteins, and is a valuable contribution to the diagnosis of TTD.

Successful treatment of acute respiratory distress syndrome and severe pulmonary hypertension in a child with Bordetella pertussis infection

Infection with Bordetella pertussis can cause severe illness with neurological and pulmonary complications in children. Pulmonary hypertension is an early sign of potentially fatal disease and can cause failure of conventional respiratory therapy in severe acute respiratory distress syndrome (ARDS). We report a 4 1/2-year-old boy with B. pertussis infection who developed severe ARDS and pulmonary hypertension. Because of severe neurological signs the patient did not qualify for extracorporal membrane oxygenation (ECMO). After conventional ventilation, surfactant and high frequency oscillation ventilation (HFOV) failed, treatment with nitric oxide (NO) improved oxygenation, allowing recovery without the need for ECMO. The patient survived with few sequelae. Thus, this treatment may be an option in high-risk children who meet the criteria for ECMO but are excluded because of poor neurological status, as in our patient.

Propionic acidemia revisited: a workshop report

Propionic acidemia (PA) is one of the most frequent organic acidurias, but information on the outcome of individuals with PA is rather limited. We present data of 49 patients with PA, which were gathered from 18 metabolic centers throughout Central Europe on the occasion of an international workshop. All patients were identified by selective metabolic screening, and 86% of them were classified as having early-onset PA owing to their presentation with clinical symptoms within the first 90 days of life. Mortality rate was one third, and details of symptoms and treatment of the surviving patients are discussed. The great variation of phenotypic expression of the disease and different therapeutic strategies (especially in regard to the degree of protein restriction) used at the various institutions involved in this study imply the need for a registry of PA patients and for a multicenter prospective treatment study.

The clinical spectrum of mitochondrial disease in 75 pediatric patients

The clinical presentation of mitochondrial disorders in childhood is highly variable causing difficulties in diagnosis and management. We assessed records of 75 children (48 male, 27 female) with a biochemically and/or molecularly established mitochondrial disorder in a retrospective, multicentric study. The predominant biochemical defect was an isolated respiratory chain complex IV, followed by respiratory chain complex I, combined respiratory chain, and isolated pyruvate dehydrogenase complex (PDHC) deficiencies. For the 75 patients, the predominant clinical presentations were a nonspecific encephalomyopathy (n = 34) and Leigh syndrome (n = 17). Classical mitochondrial syndromes with associated mutations of the mitochondrial DNA were rare (n = 12). Eleven children had a lethal infantile mitochondrial disease (LIMD). This group comprised a considerable variety of clinical pictures, and the cohort was big enough to show the high frequency and wide spectrum of nonneuromuscular symptoms in mitochondrial disorders in childhood.

Minimum birth prevalence of mitochondrial respiratory chain disorders in children

Mitochondrial respiratory chain disorders comprise a group of perhaps several hundred different genetic diseases. Each individual disorder is rare, but collectively they account for substantial use of health care resources. However, few accurate data on prevalence are available due to problems such as variation in clinical presentation, age of onset, referral practices and limitations of diagnostic methodologies. With this retrospective study, we aimed to determine the minimum birth prevalence of respiratory chain disorders that have onset in childhood, that is the proportion of births that will have onset of symptoms caused by a respiratory chain defect by 16 years of age. Of the 1 706 694 children born in the three south-eastern states of Australia (New South Wales, Victoria and South Australia) between January 1st 1987 and December 31st 1996, samples from 430 were referred for investigation of a respiratory chain disorder. Definite diagnosis of a respiratory chain disorder was made in 86 cases based on defined clinical, pathological, enzyme and molecular criteria. Age at presentation ranged from 0 to 129 months (median 4 months). The total data set predicts a minimum birth prevalence for respiratory chain disorders in children of 5.0/100 000 [95% confidence interval (CI) 4.0-6.2]. A significantly higher figure of 58.6/100 000 (95% CI 34.7-92.6) was noted for Australian families of Lebanese origin. Clinical awareness of respiratory chain disorders and investigation methods have improved since 1987, but not all affected children would have been recognized as such from the more recent years. The minimum birth prevalence of 6.2/100 000 (95% CI 4.5-8.4) for the 43 patients born between 1991 and 1994 is thought to be a more accurate estimate for respiratory chain disorders presenting in childhood. Combining our data with a previous study on prevalence of adult-onset respiratory chain disorders predicts a minimum birth prevalence of 13.1/100 000 or 1/7634 for respiratory chain disorders with onset at any age.

Identification of 16 novel mutations in the argininosuccinate synthetase gene and genotype-phenotype correlation in 38 classical citrullinemia patients

Classical citrullinemia (CTLN1), a rare autosomal recessive disorder, is caused by mutations of the argininosuccinate synthetase (ASS) gene, localized on chromosome 9q34.1. ASS functions as a rate-limiting enzyme in the urea cycle. Previously, we identified 32 mutations in the ASS gene of CTLN1 patients mainly in Japan and the United States, and to date 34 different mutations have been described in 50 families worldwide. In the present study, we report ASS mutations detected in 35 additional CTLN1 families from 11 countries. By analyzing the entire coding sequence and the intron-exon boundaries of the ASS gene using RT-PCR and/or genomic DNA-PCR, we have identified 16 novel mutations (two different 1-bp deletions, a 67-bp insertion, and 13 missense) and have detected 12 known mutations. Altogether, 50 different mutations (seven deletion, three splice site, one duplication, two nonsense, and 37 missense) in 85 CTLN1 families were identified. On the basis of primary sequence comparisons with the crystal structure of E. coli ASS protein, it may be concluded that any of the 37 missense mutations found at 30 different positions led to structural and functional impairments of the human ASS protein. It has been found that three mutations are particularly frequent: IVS6-2A>G in 23 families (Japan: 20 and Korea: three), G390R in 18 families (Turkey: six, U.S.: five, Spain: three, Israel: one, Austria: one, Canada: one, and Bolivia: one), and R304W in 10 families (Japan: nine and Turkey: one). Most mutations of the ASS gene are "private" and are distributed throughout the gene, except for exons 5 and 12-14. It seems that the clinical course of the patients with truncated mutations or the G390R mutation is early-onset/severe. The phenotype of the patients with certain missense mutations (G362V or W179R) is more late-onset/mild. Eight patients with R86H, A118T, R265H, or K310R mutations were adult/late-onset and four of them showed severe symptoms during pregnancy or postpartum. However, it is still difficult to prove the genotype-phenotype correlation, because many patients were compound heterozygotes (with two different mutations), lived in different environments at the time of diagnosis, and/or had several treatment regimes or various knowledge of the disease.

Lung function and symptom perception in children with asthma and their parents

A large proportion of children with asthma are managed without recourse to specialized care, and treatment decisions are based solely on symptoms as reported by the children and their parents. We investigated 90 school-age children with the diagnosis of asthma and their accompanying parent to evaluate whether we can obtain better information by using three different means of asking for asthma symptoms: a questionnaire for children (QSR(children)), "smilies," and a visual analogue scale for children (VAS(children)). Furthermore, we analyzed the relationship between these symptom reports and lung function results. Finally, we attempted to determine whether performing a lung function test contributes relevant information toward improving asthma management. Multiple linear regression adjusted for age and gender showed a significant relationship between VAS for children and forced expiratory volume in 1 sec (FEV(1)) (P = 0.047) and maximal expiratory flow at 50% of forced vital capacity (MEF(50)) (P = 0.037). Neither age, gender, QSR for children, "smilies for children" nor all the parents' scores showed a significant association with lung function measurement in the regression model. Subgroup analysis with Spearman's rank correlation coefficients by age group revealed significant correlation in children <10 years between VAS for children, QSR for parents, smilies for parents, and the lung function parameters FEV(1), and MEF(50). Above age 10 years there was no correlation at all, with the accuracy correlation ranging from -0.04 to +0.21. Our data demonstrate that reported symptoms do not reliably correlate with lung function results in asthmatic children and the childrens' parents, and correlation is dependent on the instrument used for symptom evaluation. In children, the VAS, and in parents, the QSR were the most valuable means of obtaining best information on asthma symptoms. This underlines the importance of supplementing information on asthma symptoms with lung function measurements to more reliably assess the severity of asthma.

Clinical heterogeneity in patients with mutations in the NDUFS4 gene of mitochondrial complex I

A comparison of the clinical presentation, disease course and results of laboratory and imaging studies of all patients so far published with a NDUFS4 mutation are presented. This reveals marked clinical heterogeneity, even in patients with the same genotype.

Clinical and Experimental Results on Cardiac Troponin Expression in Duchenne Muscular Dystrophy

Background: Because of controversial earlier studies, the purpose of this study was to provide novel experimental and additional clinical data regarding the possible reexpression of cardiac troponin T (cTnT) in regenerating skeletal muscle in Duchenne muscular dystrophy (DMD).

Methods: Plasma from 14 patients (mean age, 7.5 years; range, 5.7–19.4 years) with DMD was investigated for creatine kinase (CK), the CK MB isoenzyme (CKMB), cTnT and cardiac troponin I (cTnI), and myoglobin. cTnT concentrations were measured by an ELISA (second-generation assay; Roche) using the ES 300 Analyzer. cTnI, myoglobin, and CKMB were measured by an ELISA using the ACCESS System (Beckman Diagnostics). Troponin isoform expression was studied by Western blot analysis in remnants of skeletal muscle biopsies of three patients with DMD and in an animal model of DMD (mdx mice; n = 6).

Results: There was no relation of cTnT and cTnI to clinical evidence for cardiac failure. cTnI concentrations remained below the upper reference limit in all patients. cTnT was increased (median, 0.11 μg/L; range, 0.06–0.16 μg/L) in 50% of patients. The only significant correlation was found for CK (median, 3938 U/L; range, 2763–5030 U/L) with age (median, 7.5 years; range, 6.8–10.9 years; r = −0.762; P = 0.042). Western blot analysis of human or mouse homogenized muscle specimens showed no evidence for cardiac TnT and cTnI expression, despite strong signals for skeletal muscle troponin isoforms.

Conclusions: We found no evidence for cTnT reexpression in human early-stage DMD and in mdx mouse skeletal muscle biopsies. Discrepancies of cTnT and cTnI in plasma samples of DMD patients were found, but neither cTnT nor cTnI plasma concentrations were related with other clinical evidence for cardiac involvement.

Clinical and experimental results on cardiac troponin expression in Duchenne muscular dystrophy

BACKGROUND

Because of controversial earlier studies, the purpose of this study was to provide novel experimental and additional clinical data regarding the possible reexpression of cardiac troponin T (cTnT) in regenerating skeletal muscle in Duchenne muscular dystrophy (DMD).

METHODS

Plasma from 14 patients (mean age, 7.5 years; range, 5.7-19.4 years) with DMD was investigated for creatine kinase (CK), the CK MB isoenzyme (CKMB), cTnT and cardiac troponin I (cTnI), and myoglobin. cTnT concentrations were measured by an ELISA (second-generation assay; Roche) using the ES 300 Analyzer. cTnI, myoglobin, and CKMB were measured by an ELISA using the ACCESS System (Beckman Diagnostics). Troponin isoform expression was studied by Western blot analysis in remnants of skeletal muscle biopsies of three patients with DMD and in an animal model of DMD (mdx mice; n = 6).

RESULTS

There was no relation of cTnT and cTnI to clinical evidence for cardiac failure. cTnI concentrations remained below the upper reference limit in all patients. cTnT was increased (median, 0.11 microg/L; range, 0.06-0.16 microg/L) in 50% of patients. The only significant correlation was found for CK (median, 3938 U/L; range, 2763-5030 U/L) with age (median, 7.5 years; range, 6.8-10.9 years; r = -0.762; P = 0.042). Western blot analysis of human or mouse homogenized muscle specimens showed no evidence for cardiac TnT and cTnI expression, despite strong signals for skeletal muscle troponin isoforms.

CONCLUSIONS

We found no evidence for cTnT reexpression in human early-stage DMD and in mdx mouse skeletal muscle biopsies. Discrepancies of cTnT and cTnI in plasma samples of DMD patients were found, but neither cTnT nor cTnI plasma concentrations were related with other clinical evidence for cardiac involvement.

Predicting survival infants ventilated with high-frequency oscillation

This retrospective study identifies factors which may predict outcome in preterm infants and infants born at term, ventilated with high-frequency oscillation (HFO). In a 16-bed neonatal and paediatric intensive care unit (level III), 58 consecutive preterm and term infants with a median gestational age of 30 (24-41) weeks and a median birth weight of 1200 (520-3660) g suffered respiratory failure and were managed with HFO as rescue therapy. Forty-nine patients (84%) received exogenous surfactant before HFO which was initiated after a median interval of 20 (1-910) hours following birth. The overall survival rate was 70%. No significant differences existed between survivors and nonsurvivors in respect to demographic data. A greater proportion of patients with respiratory distress syndrome survived (76%) than with lung hypoplasia (20%) or with air-leak syndromes (pulmonary interstitial emphysema 60%, pneumothorax 28%). In survivors, the mean oxygenation index (OI) before HFO was significantly lower than that in nonsurvivors (16 +/- 1.3 vs. 26 +/- 3, p < 0.01) and showed a significant reduction of 32% within 4 hours. In contrast, mean OI increased to 68% over the first 4 hours in nonsurvivors and the difference between survivors and nonsurvivors remained significant during this time (after 2 hours: 15 +/- 1.5 vs. 30 +/- 6, p < 0.01; after 4 hours: 11 +/- 1 vs. 43 +/- 1, p < 0.01). A receiver of operator analysis revealed that an initial OI < 25 or alveolar-arterial oxygen difference (AaDO2) < 450 mmHg predicted survival with a sensitivity of 93% and a specificity of 41%. The positive predictive value was 79%; the negative predictive value, 70%.

CONCLUSION

A low OI and AaDO2 at the beginning of HFO, improvement in oxygenation over the first four hours of HFO ventilation and no development of air-leak syndromes were associated with a high predicted survival. This allows early identification of infants who may not survive and may benefit from established and alternative modes of respiratory support such as extracorporeal membrane oxygenation, nitric oxide and liquid ventilation.

Identification of novel mutations in the PCCB gene in European propionic acidemia patients. Mutation in brief no. 253. Online

Propionyl-CoA carboxylase (PCC) is a biotin-dependent enzyme located in the mitochondrial matrix. Mutations in the PCCA and PCCB genes, which encode the a and b subunits of this heteropolymer, result in propionic acidemia (PA). We report the molecular analysis of b-deficient patients from Spain and Austria. Subjects were screened for defects affecting the PCCB gene by direct sequencing from genomic PCR products, restriction digests and mRNA analysis by RT-PCR. Study by western blot of the presence of immunoreactive b-PCC protein was also performed. A total of four novel sequence variations were found including the point mutations V205D, and M442T, and the frameshift mutation 790-791insG. Additionally, a new point change, L17M, was identified on the same allele as 790-791insG. The missense changes described above were not found in at least 40 control chromosomes analyzed. The Austrian patients were homozygous for V205D. One of the Spanish subjects was heterozygous for M442T and the known mutation c1170insT. The other Spanish patient carried L17M+790-791insG on one allele, and the described mutation E168K on the other mutant chromosome. The mutations V205D and M442T were confirmed at RNA level and also we have detected the presence of immunoreactive b-PCC protein translated from these mutant alleles. The patient having L17M+790-791insG and E168K also presented immunoreactive b-PCC protein. However, no cDNA product was obtained from the chromosome carrying L17M+790-791insG. We propose that 790-791insG, which causes a frameshift and a premature stop codon, is responsible for this finding. In any case, the translation from this mutant cDNA would produce a severity truncated peptide and, in consequence, a non-functional protein. Expression analysis of all these changes will help us to clarify their structural/functional consequences.

[SIDS prevention program in Tyrol]

In April 1994, an intervention campaign to reduce the incidence of sudden infant death syndrome (SIDS) was established in the Tyrol. The campaign was intended to increase knowledge concerning risk factors for SIDS in the general community and to improve individual care for infants at risk. In contrast to interventional programmes in other federal states of Austria (i.e. Vorarlberg, Styria), this programme did not utilise polysomnography for identifying infants at risk. A part of the intervention programme was the "Styrian risk questionnaire", a standardised questionnaire concerning risk factors for SIDS. Individual instructions for health care of children at risk (risk score > or = 7) were provided and, if necessary, subscription of home monitoring was performed at the out-patient department (SIDS out-patient service) of the Department of Paediatrics in Innsbruck and other paediatric departments throughout the Tyrol. The educational programme also included information concerning basic life support. Psychological support was offered to parents of SIDS infants. Risk factors for SIDS in the Tyrol before the campaign were assessed in a retrospective case-control study (time period 1984-1994; 99 SIDS infants, 136 controls). The risk of SIDS was markedly reduced when parents had detailed knowledge of the risk factors of SIDS (odds ratio (OR) 0.03; p < 0.001), which emphasises the importance of information and educational programmes. The incidence of SIDS declined after the beginning of the intervention campaign from 1.83/1000 live births (average incidence from 1984-1994) to 0.4/1000 live births and remained at this level thereafter. Post-neonatal mortality also declined from 3.9 to 1.3/1000 live births. The prevalence of the prone sleeping position declined immediately after the campaign (53.7% vs. 5.4%, p < 0.001), as did the frequency of maternal smoking during pregnancy (22.9% vs. 14.5%, p < 0.01). Breast feeding became more popular. In all, the low-cost intervention programme in the Tyrol proved to be highly efficient in reducing the risk of SIDS and in maintaining this effect for several years.

Oral creatine supplementation in Duchenne muscular dystrophy: a clinical and 31P magnetic resonance spectroscopy study

The decrease in intracellular creatine concentration in Duchenne muscular dystrophy may contribute to the deterioration of intracellular energy homeostasis and may thus be one of the factors aggravating muscle weakness and degeneration. Oral creatine supplementation should have potential in alleviating the clinical symptoms. To test this hypothesis, creatine was orally administered over a period of 155 days to a 9-year-old patient with Duchenne muscular dystrophy. In accordance with previous investigations on normal subjects and trained athletes, the patient experienced improved muscle performance during creatine supplementation. Further evidence supporting this hypothesis derived from plasma creatine kinase and lactate dehydrogenase activities and repeated 31P magnetic resonance spectroscopy of the gastrocnemius muscle. These preliminary observations indicate a potential role for creatine supplementation in the symptomatic therapy of patients with muscle disease.

Elevated plasma bile acid concentrations in two sisters with tyrosinaemia type I

A 21-month-old girl suffering from tyrosinaemia type I and undergoing treatment with 2-(2-nitro-4-trifluoro-methylbenzoyl)-1,3-cyclohexanedione (NTBC) presented with pruritus which rapidly ceased with administration of high doses of ursodeoxycholic acid. Determination of plasma bile acids revealed clearly elevated levels both in samples taken before and after the onset of NTBC therapy, thus indicating, that the increase was not related to the administration of this drug. This result is corroborated by data from the first patient's newborn sister, diagnosed with the same disease, who showed elevated plasma bile acid concentrations in all samples examined, except for the cord plasma. This is the first report on altered bile acid concentrations in tyrosinaemia type I, and underlines the need for thorough investigation of bile acid metabolism in this disease.

Odd-numbered long-chain fatty acids in propionic acidaemia

In patients with propionic acidaemia (PA), the increased intracellular concentration of propionyl-CoA leads to a relative abundance of odd-numbered long-chain fatty acids (OLCFAs) in body lipids. We investigated the relative amount of OLCFA in erythrocyte membrane lipids over a period of 1-8 years in five patients with early onset PA and present their clinical outcome. After extraction from erythrocyte membrane lipids and esterification, fatty acids were analysed by capillary column gas chromatography. The sum of the OLCFA 15- and 17- carbon saturated and 17-carbon monounsaturated fatty acids (C15:0, C17:0, C17:1) was calculated and expressed as a percentage of the total C14-C22 fatty acids in the sample. Three patients (pccBC-complementation group) presented with a stable clinical course and showed OLCFA values usually below 1.9% (median % +/- SD: 1.4+/-0.5, 1.6+/-0.5, 1.8+/-0.5). Two patients (pccA-complementation group) had a more severe course of the disease and showed higher medians and a broader range of OLCFA levels (2.2+/-1.2 and 2.2+/-0.8).

CONCLUSION

Our study shows that odd-numbered long-chain fatty acid concentrations are increased in patients with propionic acidaemia and are higher in those with a more severe clinical course. The value of odd-numbered long-chain fatty acids in the assessment of the phenotypic severity and in the management of propionic acidaemia remains to be proven in a prospective long-term study with more patients of differing phenotype.

Plasma concentrations and renal clearance of orotic acid in argininosuccinic acid synthetase deficiency

Argininosuccinic acid synthetase deficiency (ASD) is a rare disorder of urea cycle metabolism, with pronounced citrullinemia and orotic aciduria being characteristic biochemical features. To further investigate the role of plasma orotic acid and its possible use for monitoring the metabolic status in ASD, we determined plasma orotic acid, amino acid, and ammonium levels in plasma samples collected over a period of 3 years from a patient who is now 8 years of age. Orotic acid plasma concentrations varied widely from less than 1 micromol/l to more than 60 micromol/l. The renal clearance of orotic acid was eightfold the glomerular filtration rate, thus supporting an active mechanism underlying the excretion of this pyrimidine. Data obtained during a metabolic crisis yielded a statistically significant linear correlation of orotic acid plasma levels with those of glutamine and ammonium, which are generally accepted for assessment of the successful treatment of this disorder. Our data revealed no advantage of plasma orotic acid concentrations over the established amino acids (glutamine and arginine) and ammonium for determining acute treatment responses. Since several effects of high levels of orotic acid have been described in mammals, further research is necessary to assess a possible contribution of orotic acid to the pathogenesis of ASD and the use of plasma orotic acid levels in the long-term monitoring of these patients.

Complications of percutaneous insertion of Hickman catheters in children

BACKGROUND/PURPOSE

The aim of this study was a retrospective evaluation of insertion and management complications of percutaneous Hickman catheter lines in pediatric patients to investigate whether the complication rate is acceptable in comparison with other insertion methods or other age groups.

METHODS

Over a period of 22 months a total of 27 Hickman catheters were inserted in 22 pediatric patients (20 oncological, 2 nononcological; age 6 weeks to 17.5 years).

RESULTS

Twenty-three of 36 insertion attempts (63.9%) were successful at first attempt. In another 4 patients, catheters were placed after repeated attempts. In an additional 4 patients, catheters were inserted by surgeons after percutaneous insertion failed. As immediate complications, 1 pneumothorax and 1 malposition were seen. Late complications included 1 to 29 (median, 8) days of fever in 15 patients, corresponding to 53 of 1,000 catheter days. Fourteen patients showed 21 positive blood cultures, including 11 cases of Staphylococcus epidermides, which might be related to the catheter. Antibiotics were given for a total of 1 to 130 (median, 35) days, that is 205 of 1,000 catheter days. No catheter was removed because of infectious complications. The total life span of the Hickman catheters was 1 to 371 (median, 163) days, the patients were in the hospital from 1 to 351 (median, 102) days because of their underlying disease. At the end of the study period, 8 of 27 (29.6%) catheters remained functioning in situ; 9 (33.3%) had been selectively removed. Two patients died with the catheter (7.4%) functioning well. Another 2 patients showed catheter thrombosis. Six catheters (22.2%) in 5 patients showed inadvertent dislodgement.

CONCLUSION

Percutaneous Hickman catheter insertion in pediatric patients is effective; however, complication rate is relevant, but not higher than percutaneous insertion of subclavian vein or Hickman catheters in adults.

Different clinical aspects of debrancher deficiency myopathy

OBJECTIVE

To characterise the main clinical phenotypes of debrancher deficiency myopathy and to increase awareness for this probably underdiagnosed disorder.

METHODS

The diagnosis of debrancher deficiency was established by laboratory tests, EMG, and muscle and liver biopsy.

RESULTS

Four patients with debrancher deficiency myopathy were identified in the Tyrol, a federal state of Austria with half a million inhabitants. Clinical appearance was highly variable. The following phenotypes were differentiated: (1) adult onset distal myopathy; (2) subacute myopathy of the respiratory muscles; (3) severe generalised myopathy; and (4) minimal variant myopathy. Exercise intolerance was uncommon. The clinical course was complicated by advanced liver dysfunction in two patients and by severe cardiomyopathy in one. All had raised creatine kinase concentrations (263 to 810 U/l), myogenic and neurogenic features on EMG, and markedly decreased debrancher enzyme activities in muscle or liver biopsy specimens. The findings were substantiated by a review of 79 previously published cases with neuromuscular debrancher deficiency.

CONCLUSIONS

This study illustrates the heterogeneity of neuromuscular manifestations in debrancher deficiency. Based on the clinical appearance, age at onset, and course of disease four phenotypes may be defined which differ in prognosis, frequency of complications, and response to therapy.

Normal ascorbic acid in cerebrospinal fluid of patients with infantile neuronal ceroid-lipofuscinosis

Neuronal ceroid-lipofuscinoses (NCL) are a group of neurodegenerative disorders. There is much evidence for a role of peroxidation processes in the pathogenesis of NCL, although this would certainly be indirect. Reduced total antioxidant activity of cerebrospinal fluid (CSF) has been reported in NCL. Since ascorbic acid represents a major antioxidant in CSF, we have now determined this parameter in CSF of two patients with the infantile form of NCL (Santavuori-Haltia disease). However, the ascorbic acid values obtained (103.6 and 181.3 microM) are comparable with control values from the literature as well as with those measured in groups of children with neurologic/psychiatric diseases other than NCL (mean +/- standard deviation: 137.1+/-41.3 microM), with suspected (but excluded) meningitis (124.1+/-34.0 microM) and acute lymphoblastic leukemia (131.7+/-17.0 microM). Our results indicate that CSF ascorbic acid concentrations are not affected by peroxidation processes in infantile NCL, but reveal a sharply decreased ascorbic acid concentration in one of the non-NCL patients, possibly associated with his convulsions and/or his anticonvulsant therapy.

The therapeutic potential of oral creatine supplementation in muscle disease

The decrease in intracellular creatine concentration observed in a number of muscle diseases may deplete energy homeostasis and may, therefore, be one of the factors determining and/or aggravating muscle weakness and degeneration. Two hypotheses are put forward in the present communication to explain: (i) the mechanisms leading to the disturbances in creatine metabolism found in various muscle diseases; and (ii) the potential of oral creatine supplementation in alleviating the clinical symptoms.

High resolution respirometry of permeabilized skeletal muscle fibers in the diagnosis of neuromuscular disorders

High resolution respirometry in combination with the skinned fiber technique offers the possibility to study mitochondrial function routinely in small amounts of human muscle. During a period of 2 years, we investigated mitochondrial function in skeletal muscle tissue of 13 patients (average age = 5.8 years). In all of them, an open muscle biopsy was performed for diagnosis of their neuromuscular disorder. Mitochondrial oxidation rates were measured with a highly sensitive respirometer. Multiple substrate-inhibitor titration was applied for investigation of mitochondrial function. About 50 mg fibers were sufficient to obtain maximal respiratory rates for seven different substrates (pyruvate/malate, glutamate/malate, octanoylcarnitine/malate, palmitoylcarnitine/malate, succinate, durochinol and ascorbate/TMPD). Decreased respiration rates with reference to the wet weight of the permeabilized fiber could immediately be detected during the course of measurements. In 4 patients with mitochondrial encephalomyopathy (MEM) the respiration pattern indicated a specific mitochondrial enzyme defect, which was confirmed in every patient by measurements of the individual enzymes (one patient with PDHC deficiency, one with complex I deficiency and two patients with combined complex I and IV deficiency). In the 6 patients with spinal muscular atrophy (SMA) oxidation rates were found to be decreased of 23 +/- 5% of controls. The normalized respiration pattern was comparable to that of the controls indicating a decreased content of mitochondria in SMA muscle with normal functional properties. Also in the 3 patients with Duchenne muscular dystrophy (DMD) decreased oxidation rates (42 +/- 5%) were detected. In addition a low RCI (1.2) indicated a loose coupling of oxidative phosphorylation in the mitochondria of these patients. It is concluded that investigation of mitochondrial function in saponin skinned muscle fibers using high resolution respirometry in combination with multiple substrate titration offers a valuable tool for evaluation of mitochondrial alterations in muscle biopsies of children suffering from neuromuscular disorders.

Metabolic stroke in carbamyl phosphate synthetase deficiency

Stroke-like episodes with hemiparesis have been described in children with different inherited metabolic diseases. We report the novel observation of a severe stroke as the presenting sign in an 18-month-old girl with carbamyl phosphate synthetase (CPS) deficiency. MRI revealed infarction within the territory of the right middle cerebral artery. Localized 1H-NMR spectroscopy showed elevation of glutamine (at 2.0-2.5 and 3.7 ppm) and lactate within the region of infarction. CPS activity in the liver was reduced (2.5 mU/ mg protein, n = 12-35). On a protein-restricted diet including arginine supplementation, the child has developed well with moderate mental retardation: no neurologic relapses have been observed over a period of 4 years. CPS deficiency has to be added to the list of metabolic diseases that may lead to stroke-like episodes. In every case of unclear hemiparesis in childhood, urea cycle defects should be included in the differential diagnosis.

Microheterogeneity of serum glycoproteins and their liver precursors in patients with carbohydrate-deficient glycoprotein syndrome type I: apparent deficiencies in clusterin and serum amyloid P

Serum and liver protein patterns were studied, respectively, in 5 patients (serum) and 1 patient (liver) with carbohydrate-deficient glycoprotein syndrome (CDGS) type I by high-resolution two-dimensional electrophoresis (2-DE) and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The pattern of serum glycoproteins in all 5 patients presented abnormal trains of isoforms with decreased mass (delta molecular weight 3000) and all showed a cathodal shift. Two-dimensional electrophoresis and SDS-PAGE mass analysis of transferrin, alpha1 -antitrypsin, haptoglobin beta-chain, and alpha1-acid glycoprotein after neuraminidase and N-glycosidase F treatments demonstrated that the additional trains of the isoforms found in CDGS type I contain homologous species of isoforms. Some of them still showed charge differences, and all still contained glycans except for transferrin, with some unusual nonglycosylated isoforms. In addition, deficiencies in clusterin and serum amyloid P, not described so far, have been found in all 5 patients. The two-dimensional pattern of immunodetected precursors of serum proteins in liver cells from 1 patient with CDGS showed abnormal low-mass precursors and the absence of the precursors normally found in controls. These results suggest that these abnormal precursors accumulate during the early oligosaccharide processing of the nascent protein-bound oligosaccharides and that glycoprotein precursors undergo an altered intracellular transport while the post-translational processing along the normal pathway is still apparently functioning in patients with CDGS.