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Background Free carnitine (C0) and short-chain acylcarnitine (SCA) blood concentrations play a significant role in fatty acid oxidation process during the first days of life. The aim of this study was to demonstrate C0 and SCA concentrations in Dried Blood Spots (DBS) of full term breastfed infants in relation to their birth weight (BW) perinatally. Methods Breastfed full term infants (n = 12000, 6000 males, 6000 females) with BW 2000–4000 g were divided into 4 equal groups: Group A, 2000–2500 g, B 2500–3000 g, C 3000–3500 g and D 3500–4000 g. Blood samples in the form of DBS were collected on the 3rd day of life and analyzed via a liquid chromatography tandem mass spectrometry (LC-MS/MS) protocol. Results BW-related C0 and SCAs were found as follows: C0 was determined to be statistically significantly higher in group A (BW 2000–2500 g) in both males and females. Lower acetylcarnitine (C2) and hydroxybutyrylcarnitine (C4OH) blood concentrations were detected in group A of both sexes, whereas butyrylcarnitine (C4) concentrations were found to be lower in the same group of males only. Furthermore, high concentrations of C2 and C4OH were shown in group D (BW 3500-4000 g) in both sexes. SCA sum of means ± SD values in males and females of group A were statistically significantly lower as compared to other study groups. Conclusion Due to the number of the samples, data from this study could be applied as neonatal screening reference values for full term breastfed newborns in relation to their birth weight.

Background Propionic acidemia (PA) is a serious metabolic disorder, and different approaches have been applied to its prenatal diagnosis. To evaluate the reliability and validity of a biochemical strategy in the prenatal diagnosis of PA, we conducted a retrospective study of our 11-year experiences at a single center. Methods We accumulated data from 78 pregnancies from 58 families referred to our center and provided prenatal diagnosis by directed genetic analysis and/or metabolite measurement using tandem mass spectrometry (MS/MS) and gas chromatography/mass spectrometry (GC/MS) of amniotic fluid (AF) samples. Results Sixty-five unaffected fetuses (83.33%) and 13 affected fetuses (16.67%) were confirmed in our study. The characteristic metabolites including propionylcarnitine (C3) level, C3/acetylcarnitine (C2) ratio and 2-methylcitric acid (2MCA) level in unaffected and affected groups showed significant differences (P P > 0.05).Of the 78 pregnancies, 24 fetuses were found to have either one causative pathogenic variant or were without genetic information in the proband. Three of these fetuses had elevated AF levels of C3, C3/C2 ratio, and 2MCA and, thus, were determined to be affected, while the remaining fetuses were determined to be unaffected based on a normal AF metabolite profile. Our genetic and biochemical results were highly consistent with postnatal follow-up results on all unaffected fetuses. Conclusions We conclude that a biochemical approach can serve as a fast and convenient prenatal diagnostic method for pregnancies at an increased risk for PA, which could be used in conjunction with genetic testing for precise prenatal diagnosis of this disorder. In our analysis, the characteristic metabolites C3 level, C3/C2 ratio, and 2MCA level in AF supernatant were dependable biochemical markers for diagnosis, of which the C3/C2 ratio appears to be the most reliable biochemical marker for the prenatal diagnosis of PA.

Propionic acidemia (PA) is a disorder of organic acid metabolism which typically presents with acute encephalopathy-like symptoms associated with metabolic acidosis and hyperammonemia during the neonatal period. The estimated incidence of symptomatic PA in Japan is 1/400,000. The introduction of neonatal screening using tandem mass spectrometry has revealed a far higher disease frequency of approximately 1/45,000 live births due to a prevalent variant of c.1304T>C (p.Y435C) in PCCB, which codes β-subunit of propionyl-CoA carboxylase. Our questionnaire-based follow-up study reveals that most of these patients remain asymptomatic. However, reports on symptomatic patients exhibiting cardiac complications such as cardiomyopathy and QT prolongation have been increasing. Moreover, there were even cases in which these cardiac complications were the only symptoms related to PA. A currently ongoing study is investigating the risk of cardiac complications in patients with neonatal screening-detected PA caused by this common variant.

Increased cytokine expression contributes to the pathogenesis of cancer anorexia–cachexia syndrome. Carnitine may reduce inflammation in chronic diseases. We tested the effects of L-propionylcarnitine (PC group) or saline (C group) on food intake (FI), body composition, and inflammatory status of MCA-sarcoma-bearing rats. On tumor appearance, rats were randomly assigned to daily i.p. injection of L-propionylcarnitine (250 mg/kgBW/d; n = 8) or saline (equal volume; n = 8). FI and fat-free mass wasting improved in PC rats only (p < .01 vs. controls). Cytokines’ levels decreased in PC rats vs. controls (p < .02). Results suggest that carnitine may ameliorate cancer anorexia–cachexia, via reduction of the inflammatory status.

Propionyl-l-carnitine (PLC) has been introduced among the therapeutic approaches of peripheral arterial disease, and more recently, an increase of intimal cell apoptosis has been demonstrated to contribute to its effectiveness in rabbit carotid postinjury myointimal hyperplasia prevention. How PLC mediates these effects on vascular smooth muscle cells (SMCs) remains poorly understood. We investigated the role of NF-kappaB in PLC-induced arterial remodeling. In vivo, daily PLC treatment 15 days after injury resulted in a reduction of relative rat aortic intimal volume, an increase of apoptosis, Bax up-regulation without changing the Bcl-2 level, and a reduction of NF-kappaB, vascular cell adhesion molecule-1, monocyte chemotactic protein-1, and survivin in myointimal thickening compared with controls. In the presence of 10% serum, a reduced G(1) --S phase progression preceded PLC-induced intimal cell apoptosis; in 0.1% serum cultures, in a dose-dependent manner, PLC rapidly induced intimal cell apoptosis and reduced p65, p50, IAP-1, and IAP-2 expression. Inhibiting NF-kappaB activation through SN50 increased apoptotic rate and Bax expression in intimal but not in medial SMCs, and successive PLC treatment failed to induce a further increase in apoptotic rate. Bax antisense oligodeoxynucleotide reduced PLC-induced intimal cell apoptosis and cytochrome c release. The PLC-induced attenuation of NF-kappaB activity in intimal cells was also due to the increase of IkappaB-alpha bioavailability, as the result of a parallel induction of IkappaB-alpha synthesis and reduction of phosphorylation and degradation. Collectively, these findings document that NF-kappaB activity inhibition contributes to PLC-induced proliferative arrest and Bax-related apoptosis of intimal SMCs.

Objective Oxidative stress seems to play a role in impairing flow-mediated dilation (FMD) in patients with peripheral artery disease (PAD) but the underlying mechanism is still undefined. We evaluated whether NOX2, the catalytic core of NADPH oxidase, the most important producer of reactive oxidant species (ROS), is implicated in impairing FMD. Methods We measured FMD, urinary isoprostanes, a marker of oxidative stress, nitric oxide generation by serum levels of nitrite/nitrate (NOx), and serum levels of soluble NOX2-derived peptide (sNOX2-dp), a marker of NOX2 activation, in 50 PAD patients and 50 controls. Also, we performed an interventional cross-over study to assess if propionyl-l-carnitine (PLC) (6g/day), vs. placebo, was able to affect FMD via an oxidative stress-mediated mechanism. Results Compared to controls, patients with PAD had enhanced sNOX2-dp and isoprostanes and reduced NOx and FMD. Multiple linear regression analysis showed that FMD was independently associated with sNOX2-dp. After PLC infusion FMD increased while sNOX2-dp and isoprostanes significantly decreased; no changes were observed after placebo. In vitro study by incubating platelets or white cells with PLC demonstrated a significant inhibition of p47 phox translocation on cellular surface and ROS generated by NOX2 activation. Conclusion This study suggests that in PAD patients ROS generated by NOX2 contribute to reduce FMD and that the administration of an antioxidant is able to improve arterial dilatation via NOX2 inhibition.

Aims To investigate the existence of a relationship among flow-mediated dilation (FMD), nitric oxide (NO), and oxidative stress in patients with peripheral arterial disease (PAD), and to assess if the administration of an antioxidant was able to improve arterial dilatation. Methods and results We performed a cross-sectional study comparing FMD, 8-Hydroxy-2-deoxy-2-deoxyguanosine (8-OHdG), a marker of oxidative stress, and nitrite/nitrate (NOx) serum levels in a population of 25 PAD patients and 40 controls. In the second part of the study, 21 PAD patients were randomly allocated to a treatment sequence of 7 days of i.v. infusion of placebo or 6 g/day propionyl-l-carnitine (PLC) in a cross-over design. Compared with controls, patients with PAD had enhanced 8-OHdG serum levels (2.4 ± 1.2 vs. 4.24 ± 3.11 ng/mL; P < 0.001), reduced NOx (17.02 ± 6.11 vs. 11.28 ± 6.02 µM; P < 0.001), and lowered FMD (10.34 ± 2.14 vs. 6.69 ± 2.95; P < 0.001). PLC infusion was associated with an increase of FMD [from 6.6 ± 0.6 to 11.1 ± 1.2% (mean ± SE), P = 0.004] and NOx (from 14.5 ± 1.4 to 17.1 ± 1.2 µM; +18%, P = 0.012) and a decrease of 8-OHdG (from 3.62 ± 0.37 to 2.64 ± 0.32 ng/mL; −27%, P < 0.001). No changes were observed after placebo treatment. Conclusion This study shows that in PAD patients, oxidative stress is implicated in determining reduced FMD.

We investigated the effect of carnitine analogues on the physiology of Lactobacillus plantarum subjected to salt stress. Salt stressed cells of L. plantarum accumulated exogenously provided carnitine and its structural analogues acetylcarnitine and propionylcarnitine to maximum concentrations of 466, 122 and 75 μmol (g dry weight of cells)−1, respectively. Addition of these carnitines to osmotically stressed medium increased growth rate. Furthermore, the intracellular amino acid pool, consisting of mainly aspartate and glutamate, was reduced when carnitine, acetylcarnitine or propionylcarnitine were included in the medium. This is the first study demonstrating a role for β-substituted acylcarnitine esters in osmoadaptation of a lactic acid bacterium.

A new sensitive high-performance liquid chromatographic procedure for the determination of L-carnitine (LC), acetyl-L-carnitine (ALC) and propionyl-L-carnitine (PLC) in human plasma has been developed. Precolumn derivatization with 1-aminoanthracene (1AA), performed in phosphate buffer in the presence of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) as catalyst, is involved. The fluorescent derivatives were isocratically separated on a reversed-phase column (C18). The eluate was monitored with a fluorimetric detector set at 248 nm (excitation wavelength) and 418 nm (emission wavelength). Because of the presence of endogenous carnitines, the validation was performed using dialyzed plasma. The identity of the derivatized compounds was assessed by mass spectrometry and the purity of the chromatographic peaks was confirmed by HPLC-tandem mass spectrometry. The limits of quantitation were 5 nmol/ml for LC, 1 nmol/ml for ALC and 0.25 nmol/ml for PLC. The recovery of the extraction procedure was in the range 82.6%-95.4% for all 3 compounds. Good linearity (R approximately 0.99) was observed within the calibration ranges studied: 5-160 nmol/ml for LC, 1-32 nmol/ml for ALC and 0.25-8 nmol/ml for PLC. Precision was in the range 0.3-16.8% and accuracy was always lower than 10.6%.