Cerebrotendinous xanthomatosis without neurological involvement.

BACKGROUND: Cerebrotendinous xanthomatosis (CTX) is an autosomal recessively inherited inborn error of metabolism. Neurological symptoms are considered to be a clinical hallmark of untreated adult patients. We describe a 'milder CTX phenotype', without neurological involvement. METHODS: We performed a retrospective patient file study in 79 genetically confirmed Dutch patients with CTX (55 patients aged ≥ 21 years) to study the clinical heterogeneity of CTX. We studied the frequency of adult patients with CTX without neurological involvement at diagnosis, in our Dutch cohort, and included a family from South Africa and patients from Italy, USA, Chile and Asia from the literature. RESULTS: In total, we describe 19 adult patients with CTX from 16 independent families, without neurological symptoms at diagnosis. A relatively small percentage (21%, n = 4) had a history of cataract. The majority, 84% (n = 16), presented with tendon xanthomas as the sole or predominant feature. The majority of patients showed increased plasma cholesterol levels. No correlation was found between this 'milder phenotype', the cholestanol levels and the CYP27A1 genotype. In addition, we describe three novel mutations in the CYP27A1 gene. CONCLUSIONS: This study shows the clinical heterogeneity of CTX, highlighting the existence of a 'milder phenotype', that is without neurological involvement at diagnosis. Adult patients with CTX may present with tendon xanthomas as the sole or predominant feature, mimicking familial hypercholesterolemia. It is important to realize that the absence of neurological symptoms does not rule out the development of future neurological symptoms. As CTX is a treatable disorder, early diagnosis and initiation of treatment when additional clinical signs occur is therefore essential.

Detection of Staphylococcus aureus in cystic fibrosis patients using breath VOC profiles.

Staphylococcus aureus (S. aureus) is a common bacterium infecting children with cystic fibrosis (CF). Since current detection methods are difficult to perform in children, there is need for an alternative. This proof of concept study investigates whether breath profiles can discriminate between S. aureus infected and non-infected CF patients based on volatile organic compounds (VOCs). We collected exhaled breath of CF patients with and without S. aureus airways infections in which VOCs were identified using gas chromatography-mass spectrometry. We classified these VOC profiles with sparse partial least squares discriminant analysis. Multivariate breath VOC profiles discriminated infected from non-infected CF patients with high sensitivity (100%) and specificity (80%). We identified the nine compounds most important for this discrimination. We successfully detected S. aureus infection in CF patients, using breath VOC profiles. Nine highlighted compounds can be used as a focus point in further biomarker identification research. The results show considerable potential for non-invasive diagnosis of airway infections.

Identification of Pseudomonas aeruginosa and Aspergillus fumigatus mono- and co-cultures based on volatile biomarker combinations.

Volatile organic compound (VOC) analysis in exhaled breath is proposed as a non-invasive method to detect respiratory infections in cystic fibrosis patients. Since polymicrobial infections are common, we assessed whether we could distinguish Pseudomonas aeruginosa and Aspergillus fumigatus mono- and co-cultures using the VOC emissions. We took headspace samples of P. aeruginosa, A. fumigatus and co-cultures at 16, 24 and 48 h after inoculation, in which VOCs were identified by thermal desorption combined with gas chromatography - mass spectrometry. Using multivariate analysis by Partial Least Squares Discriminant Analysis we found distinct VOC biomarker combinations for mono- and co-cultures at each sampling time point, showing that there is an interaction between the two pathogens, with P. aeruginosa dominating the co-culture at 48 h. Furthermore, time-independent VOC biomarker combinations were also obtained to predict correct identification of P. aeruginosa and A. fumigatus in mono-culture and in co-culture. This study shows that the VOC combinations in P. aeruginosa and A. fumigatus co-microbial environment are different from those released by these pathogens in mono-culture. Using advanced data analysis techniques such as PLS-DA, time-independent pathogen specific biomarker combinations can be generated that may help to detect mixed respiratory infections in exhaled breath of cystic fibrosis patients.

Primary Carnitine (OCTN2) Deficiency Without Neonatal Carnitine Deficiency.

Although the diagnosis of a primary carnitine deficiency is usually based on a very low level of free and total carnitine (free carnitine: 1-5 µM, normal 20-55 µM) (Longo et al. 2006), we detected a patient via newborn screening with a total carnitine level 67 % of the normal value. At the age of 1 year, after interruption of carnitine supplementation for a 4-week period the carnitine profile was assessed and the free carnitine level had dropped to 10.4 µmol/l (normal: 20-55 µM) and total carnitine level had dropped to 12.7 µmol/l (normal: 25-65 µM). Transient carnitine deficiency was not likely anymore and DNA mutation analysis of the OCTN2 (SLC22A5) gene showed a homozygous c.136C>T (p.P46S) mutation, confirming the diagnosis of primary carnitine deficiency. We would like to emphasize that neonates with a primary carnitine deficiency might present with relatively high levels of total carnitine due to placental carnitine transfer, and also draw the attention to the importance of regular follow-up and the significance of genetic diagnostics in patients with a nonclassical presentation.

Clinical imaging and neuropathological correlations in an unusual case of cerebrotendinous xanthomatosis.

Cerebrotendinous xanthomatosis (CTX) is a rare autosomal recessive lipid storage disorder due to a deficiency of the mitochondrial enzyme sterol 27-hydroxylase (CYP 27) with reduced or no chenodeoxycholic synthesis. This deficiency leads to an accumulation of cholestanol in different sites such as the eye lens, central nervous system or tendons. We report a 64-year-old female patient with a progressive gait disorder associated with cognitive decline since the age of 59. The patient had no mental retardation, cataract or chronic diarrhea. Her family reported increasing behavioral modifications 10 years previously. Clinical examination revealed a spastic paraplegia and bilateral xanthomas on the Achilles tendons. Cerebral magnetic resonance imaging (MRI) revealed diffuse hyperintense T2 abnormalities in the pyramidal tracts from the internal capsules to the cerebral peduncles also Technetium-99m-ECD brain SPECT showed a severe cerebellar hypoperfusion. Serum cholestanol analysis was 7 µmol/l (N). After 2 years, she was bedridden and died of aspiration pneumonia. The neuropathological study confirmed the CTX diagnosis and the sequencing analysis revealed that she was compound heterozygous for two mutations in the CYP27A1 gene: 1435 C > T (exon 7) on one allele and a new mutation, 1017 G > C (exon 5) on the other. The interest of the present case is to report neuropathology findings strongly correlated with the MRI and SPECT abnormalities.

Alcohol increases homocysteine and reduces B vitamin concentration in healthy male volunteers--a randomized, crossover intervention study.

BACKGROUND: Few studies have examined the effect of alcohol consumption on total homocysteine (tHcy) concentrations. AIM: To assess the effect of an 8-week intervention with vodka or red wine on plasma tHcy and B vitamin concentrations in healthy male volunteers. To assess the effect on tHcy according to methylenetetrahydrofolate reductase (MTHFR) 677C>T genotype. DESIGN AND METHODS: A randomized controlled crossover intervention study measuring tHcy and serum folate and vitamin B(12) concentrations was conducted in 78 male subjects (21-70 years). Following a 2-week washout period during which no alcohol was consumed, all subjects consumed 24 g alcohol (either 240 ml red wine or 80 ml vodka)/day for a 2-week period. Following a further 2-week washout, participants consumed the alternate intervention for 2 weeks. RESULTS: A significant increase in plasma tHcy was observed after the 2-week red wine intervention (5%, P = 0.03), and a non-significant increase in tHcy with vodka intervention (3%, P = 0.09). When the two interventions were compared, the change in tHcy did not differ between the vodka and red wine interventions (P = 0.57). There were significant decreases in serum vitamin B(12) and folate concentrations, and this decrease did not differ between interventions. The increase in tHcy observed in both interventions did not vary by MTHFR 677C>T genotype. CONCLUSION: A 2-week alcohol intervention resulted in a decrease in folate and vitamin B(12) status and an increase in plasma tHcy. The effect of alcohol intervention on tHcy, folate and vitamin B(12) concentrations did not differ between the red wine and vodka intervention groups.

P-glycoprotein-deficient mice have proximal tubule dysfunction but are protected against ischemic renal injury.

The multidrug resistance gene 1 product, P-glycoprotein (P-gp), is expressed in several excretory organs, including the apical membrane of proximal tubules. After inducing acute renal failure, P-gp expression is upregulated and this might be a protective function by pumping out toxicants and harmful products of oxidative stress. We characterized renal function of P-gp knockout mice and studied its consequences in renal ischemic damage. Compared with wild-type mice, knockout mice have a lower glomerular filtration rate and renal plasma flow. An augmented urinary excretion of sodium, numerous amino acids, calcium, glucose, and low molecular weight proteins was observed along with an increased diuresis. A higher lithium plasma clearance in the knockout mice suggested proximal tubular dysfunction. Electron microscopy showed mitochondrial abnormalities in proximal tubular cells that could account for decreased adenosine triphosphate levels in the cortex. After inducing ischemia, wild-type mice showed a decrease in creatinine clearance and severe proximal tubular necrosis. In contrast, knockout mice had no signs of tubular damage. Our data indicate that P-gp knockout mice have impaired renal function but are protected against ischemic renal injury.

Association of 3-methylglutaconic aciduria with sensori-neural deafness, encephalopathy, and Leigh-like syndrome (MEGDEL association) in four patients with a disorder of the oxidative phosphorylation.

In this paper, we describe a distinct clinical subtype of 3-methylglutaconic aciduria. 3-Methylglutaconic aciduria is a group of different metabolic disorders biochemically characterized by increased urinary excretion of 3-methylglutaconic acid. We performed biochemical and genetic investigations, including urine organic acid analysis, NMR spectroscopy, measurement of 3-methylglutaconyl-CoA hydratase activity, cardiolipin levels, OPA3 gene analysis and measurement of the oxidative phosphorylation in four female patients with 3-methylglutaconic aciduria. 3-Methylglutaconic aciduria type I, Barth syndrome, and Costeff syndrome were excluded as the activity of 3-methylglutaconyl-CoA hydratase, the cardiolipin levels, and molecular analysis of the OPA3 gene, respectively, showed no abnormalities. The children presented with characteristic association of hearing loss and the neuro-radiological evidence of Leigh disease. They also had neonatal hypotonia, recurrent lactic acidemia, episodes with hypoglycemia and severe recurrent infections, feeding difficulties, failure to thrive, developmental delay, and progressive spasticity with extrapyramidal symptoms. Our patients were further biochemically characterized by a mitochondrial dysfunction and persistent urinary excretion of 3-methylglutaconic acid.

The 894 G > T variant of endothelial nitric oxide synthase (eNOS) increases the risk of recurrent venous thrombosis through interaction with elevated homocysteine levels.

BACKGROUND: Venous thrombosis is a multicausal disease involving both genetic as well as acquired risk factors. Hyperhomocysteinemia is associated with a 2-fold increased risk of recurrent venous thrombosis (RVT). Recently, the 894 G > T variant of endothelial nitric oxide synthase (eNOS) was postulated to be associated with hyperhomocysteinemia. OBJECTIVES: We hypothesized an interrelation of hyperhomocysteinemia, the eNOS 894 G > T variant and RVT risk. METHODS: The eNOS 894 G > T variant was studied in 170 cases with a history of RVT and 433 controls from the general population. RESULTS: The eNOS 894 TT genotype may increase RVT risk [odds ratio (OR) 1.3 (0.7-2.6)], but no association of the eNOS 894 G > T variant with elevated homocysteine was found in controls. Interestingly, in RVT cases the coexistence of both the 894 TT genotype and elevated tHcy levels (> 90th percentile) was more frequently present than in controls, which led to a substantially increased risk of recurrent venous thrombosis [fasting tHcy OR 5.3 (1.1-24.1), postload tHcy OR 6.5 (1.6-29.5)]. CONCLUSION: The results of the present study demonstrate that the eNOS 894 G > T variation interacts with elevated tHcy levels, leading to an increased risk of recurrent thrombotic events. This interaction points in the direction of S-nitrosation as a mechanism by which homocysteine exerts its detrimental effects on the hemostatic system.

The role of hyperhomocysteinemia in nitric oxide (NO) and endothelium-derived hyperpolarizing factor (EDHF)-mediated vasodilatation.

Hyperhomocysteinemia (HHcy) is associated with impaired endothelial-dependent vasodilatation and increased risk of atherosclerosis and thrombosis. Here, we summarize some of our previous work on the effect of HHcy on pathways involved in endothelium-dependent vasodilatation, and present new data concerning the endothelium-derived hyperpolarizing factor (EDHF)-mediated vasodilatation. We showed that the 894 G>T single-nucleotide polymorphism in the human endothelial nitric oxide synthase gene (eNOS) increased the risk of recurrent venous thrombosis in individuals with elevated homocysteine levels, indicating that the pathophysiological mechanism in HHcy involves impaired NO-mediated vasodilatation. In addition, the EDHF-mediated vasodilatation of the renal artery was disturbed in diet-induced hyperhomocysteinemic rats. Interestingly, we demonstrated that pretreatment of rats with periodate-oxidized adenosine (Adox), which is an inhibitor of S-adenosylhomocysteine hydrolase, prevented the methionine-induced rise in plasma total Hcy (tHcy) levels but not the inhibition of the EDHF pathway. Furthermore, we demonstrated that S-adenosylhomocysteine (AdoHcy) and S-adenosylmethionine (AdoMet) levels were increased in the kidneys of diet-induced HHcy rats, resulting in a decreased AdoMet:AdoHcy ratio. In addition, we demonstrated that mRNA expression of Connexin 40, which is one of the structural subunits of gap-junctions, was down-regulated in endothelial cells of HHcy rats, and correlated with elevated AdoHcy levels in kidney of these rats. These finding suggest a key role for AdoHcy in relation to decreased Cx40 mRNA expression and impaired EDHF-mediated vasodilatation of HHcy rats.

Early molecular events in the development of the diabetic cardiomyopathy.

UNLABELLED: Oxidative damage to DNA has been well documented in cardiac cells isolated from diabetic patients and rats with streptozotocin-induced diabetes mellitus (DM). This study evaluates possible molecular mechanisms for early events in the development of DM-induced cardiomyopathy. METHODS: To analyze the mechanism of overexpression of p21(WAF1/CIP1) and inhibition of cyclin D(1) expression in cardiomyocytes of diabetic rats we examined the methylation status of these genes by MS-PCR and assessed the possibility of epigenetic control of their expression. RESULTS: We found that the steady-state expression of both genes is influenced by their methylation status, as an epigenetic event, of their 5'-flanking regions upon development of diabetes. CONCLUSIONS: Oxidative damage contributes to the development of cardiomyopathy via p53-dependent activation of cardiac cell death. This pathway includes de novomethylation of the P53-inducible p21(WAF1/CIP1)-gene encoding a protein which binds to and inhibits a broad range of cyclin-cyclin-dependent kinase complexes.