Role of Plasma Amino Acids and Urinary Organic Acids in Diagnosis of Mitochondrial Diseases in Children

BackgroundDiagnostic difficulty in mitochondrial diseases (MD) results not only from the wide spectrum of symptoms and signs but also from the absence of a reliable screening or diagnostic biomarker.AimTo investigate the likelihood of MD in patients with symptoms and signs impressive of MD through quantitative measurement of plasma amino acids, and urinary organic acids.MethodsTwenty patients with symptoms and signs suggestive of MD were further evaluated by quantitative plasma amino acids and urinary organic acids assay and neuroimaging.ResultsPlasma amino acid results revealed elevation of alanine in 11, glycine in five, and proline in two patients. Abnormal urinary organic acid analysis was present in six patients; increased urinary lactate (20%), dicarboxylicaciduria (15%), and urinary ketone bodies (10%). Upon enrollment our patients scored as possible MD according to the MD scoring system. At the end of the study, five patients still scored as possible MD, eight patients as probable MD, and seven patients as definite MD. All patients with definite MD had elevated serum lactate. In three patients, elevated urinary lactate was the only abnormality. Alanine was elevated in all patients with definite MD, whereas proline was elevated in only one. Magnetic resonance imaging of the brain showed atrophic changes in one patient and bilateral basal ganglia hyperintensity in another.ConclusionUrinary organic acids and quantitative plasma amino acids can help in the diagnosis of MD, especially when the economic burden and absence of specialized centers limits the diagnosis.     

Clinical effects of mianserin in endogenous depression and their relationship to drug plasma level

1. 1. This was a single-blind, open study undertaken to assess the antidepressant efficacy of mianserin, a new tetracyclic antidepressant in in-patients with major depression (DSM III).

2. 2. The relationship between steady state plasma levels and clinical response, and the predictability of steady-state mianserin plasma levels from a single point determination after an initial dose of the drug were also studied.

3. 3. There was remarkable clinical improvement as measured by the significant (P 0.001) reduction in mean HDRS scores after first week of active treatment which continued till day 28 when mean HDRS scores were reduced to about 50% of initial mean scores.

4. 4. There was a modest correlation (r = 0.623, n.s.) between the steady state levels of mianserin and the plasma concentration 12 hours after initial dose. No significant cardiovascular effect was noted throughout the course of treatment.

5. 5. Mianserin is a safe, efficacious antidepressant with minimal cardiovascular effects. Further clinical investigations of this new useful drug are recommended.

Distinct Plasma Profile of Polar Neutral Amino Acids, Leucine, and Glutamate in Children with Autism Spectrum Disorders

The goal of this investigation was to examine plasma amino acid (AA) levels in children with Autism Spectrum Disorders (ASD, N?=?27) and neuro-typically developing controls (N?=?20). We observed reduced plasma levels of most polar neutral AA and leucine in children with ASD. This AA profile conferred significant post hoc power for discriminating children with ASD from healthy children. Furthermore, statistical correlations suggested the lack of a typical decrease of glutamate and aspartate with age, and a non-typical increase of isoleucine and lysine with age in the ASD group. Findings from this limited prospective study warrant further examination of plasma AA levels in larger cross-sectional and longitudinal cohorts to adequately assess for relationships with developmental and clinical features of ASD.     

Loci on chromosomes 6q and 6p interact to increase susceptibility to bipolar affective disorder in the national institute of mental health genetics initiative pedigrees.

BACKGROUND: We have reported genetic linkage between bipolar disorder and markers on chromosome 6q16.3-22.1 in the National Institute of Mental Health Genetics Initiative wave 3 pedigrees. Here we test for: 1) robustness of the linkage to differing analysis methods, genotyping error, and gender-specific maps; 2) parent-of-origin effects; and 3) interaction with markers within the schizophrenia linkage region on chromosome 6p. METHODS: Members of 245 families ascertained through a sibling pair affected with bipolar I or schizoaffective-bipolar disorder were genotyped with 18 markers spanning chromosome 6. Nonparametric linkage analysis was performed. RESULTS: Linkage to 6q is robust to analysis method, gender-specific map differences, and genotyping error. The locus confers a 1.4-fold increased risk. Affected siblings share the maternal more often than the paternal chromosome (p =.006), which could reflect a maternal parent-of-origin effect. There is a positive correlation between family-specific linkage scores on 6q and those on 6p22.2 (r =.26; p <.0001). Linkage analysis for each locus conditioned on evidence of linkage to the other increases the evidence for linkage at both loci (p <.0005). Logarithm of the odds (LOD) scores increased from 2.26 to 5.42 on 6q and from.35 to 2.26 on 6p22.2. CONCLUSIONS: These results support linkage of bipolar disorder to 6q, uncover a maternal parent-of-origin effect, and demonstrate an interaction of this locus with one on chromosome 6p22.2, previously linked only to schizophrenia.     

Cerebrospinal Fluid Levels of Neuropeptides, Cortisol, and Amino Acids in Patients with Epilepsy

Summary: We measured lumbar cerebrospinal fluid (CSF) levels of somatostatin, cholecystokinin, neurotensin, atrial natriuretic factor, vasoactive inhibitory peptide, neuropeptide Y, adrenocorticotrophic hormone, corticotropin releasing hormone, β-endorphin, metenkephalin, cortisol, alanine, glycine, aspartate, glutamate, taurine, and γ-aminobutyric acid in 25 inpatients with epilepsy at known interictal and postictal times and in 11 neurologically normal volunteers. There were no significant differences between interictal or postictal complex partial seizures (CPS), postictal generalized tonic-clonic seizures (GTC), and control CSF neuropeptide, cortisol, and amino acid (AA) levels. However, there were nonsignificant trends for CSF levels of several neuropeptides to be increased after CPS and GTC as compared with interictal baseline levels. There were significant correlations between levels of certain CSF neuropeptides or (AAs) and serum antiepileptic drug (AED) levels. Several correlations were noted between CSF levels of AAs, including a correlation between the excitatory neurotransmitters aspartate and glutamate identified only after CPS.     

C-R Relationship between Fasting Plasma Glucose and Unfavorable Outcomes in Patients of Ischemic Stroke withoutDiabetes

Background

Limited data are available on the impact of fasting plasma glucose (FPG) on outcomes in nondiabetic acute ischemic stroke patients.

急性颅脑损伤神经降压素含量变化及临床意义

目的和方法应用放免法动态测定51例急性颅脑损伤患者血浆及脑脊液神经降压素含量，以观察神经降压素水平在颅脑损伤组和正常对照组中的变化，并探讨其临床意义。结果颅脑损伤患者急性期血浆及脑脊液神经降压素含量显著高于对照组，且与病情轻重程度明显相关。结论神经降压素参与急性颅脑损伤后继发性病理生理过程；神经降压素受体桔抗剂成为治疗颅脑损伤的有效途径；血浆或脑脊液神经降压素动态含量，可能是判断急性颅脑损伤患者预后的重要因素。     

Tryptophan catabolism in females with irritable bowel syndrome: relationship to interferon‐gamma,severity of symptoms and psychiatric co‐morbidity

Abstract Irritable bowel syndrome (IBS) has been linked with abnormal serotonin functioning and immune activation. Tryptophan forms the substrate for serotonin biosynthesis, but it can alternatively be catabolized to kynurenine (Kyn) by the enzyme indoleamine 2,3‐dioxygenase (IDO), the main inducer of which is interferon‐gamma. The primary aim of this study was to test the hypothesis that IBS is associated with increased tryptophan (Trp) catabolism along the Kyn pathway due to increased IFN‐γ levels. Plasma Kyn, Trp and IFN‐γ levels were measured in 41 female IBS subjects and 33 controls. Indoleamine 2,3‐dioxygenase activity was assessed using the Kyn to Trp ratio. Psychiatric co‐morbidity was assessed using the Patient Health Questionnaire, and severity of IBS assessed using self‐report ordinal scales. Irritable bowel syndrome subjects had increased Kyn concentrations compared with controls (P = 0.039) and there was a trend for Kyn:Trp to be increased in the IBS group (P = 0.09). There was a positive correlation between IBS severity and Kyn:Trp (r = 0.57, P < 0.001). Those with severe IBS symptoms had increased Kyn:Trp (P < 0.005) compared to those with less severe symptoms and controls, and were over twice as likely to have depression or anxiety compared to those with less severe IBS (RR = 2.2, 95% CI 1.2–3.9). No difference in IFN‐γ levels was observed between groups; however, IFN‐γ was positively correlated with Kyn:Trp in IBS (r = 0.58, P = 0.005) but not controls (r = 0.12, P = 0.5). Females with IBS have abnormal Trp catabolism. The Kyn:Trp is related to symptom severity, and those with severe IBS symptoms have increased shunting of Trp along the Kyn pathway which contributes to the abnormal serotonergic functioning in this syndrome.     

Levels of Free Amino Acids in Serum and Cerebrospinal Fluid After Administration of Taurine to Epileptic and Normal Subjects

The modifications associated with taurine treatment of the free amino acid content of serum and cerebrospinal fluid were investigated in epileptic and control subjects. In patients with epilepsy the main findings were, in the serum, the correction toward normal of the amino acid levels that were low prior to therapy, and in the cerebrospinal fluid, the increase up to above-normal levels of glutamic acid, greatly diminished before treatment. Thus taurine, which has an anticonvulsant action appears to partially correct the amino acid imbalance in epileptics. The monitoring of taurine-induced glutamate changes in the cerebrospinal fluid could help to establish the correct therapeutic dose.     

Involvement of Src Tyrosine Kinases (SFKs) and of Focal Adhesion Kinase (FAK) in the Injurious Mechanism in Rat Primary Neuronal Cultures Exposed to Chemical Ischemia

Src family of kinases (SFKs) and focal adhesion kinase (FAK) are two important cellular signaling components known to act cooperatively in the transduction of death and survival signals. We investigated the involvement of these proteins in the mechanism of the injurious response in rat primary neuronal cultures exposed to an insult composed of chemical ischemia (poisoning with iodoacetic acid; 100 μM, for 150 min) followed by 1 h of incubation in the regular medium, an insult shown before to be associated with generation of reactive oxygen species and with the depletion of adenosine triphisphate. The exposure of the neuronal cultures to the insult resulted in cell injury, assessed by the increased release of cytoplasmic lactate dehydrogenase (LDH) into the culture media, which could be attenuated markedly by the presence of the antioxidant LY 231617. The insult resulted in the decreased level of phosphorylation of the SFKs members Src, Fyn, and Yes at the Src Y416-equivalent activation sites and of the FAK Y397 activation site, degradation of FAK to a p85 fragment, and disassembling of the FAK–SFKs complexes. The inhibition of SFKs was found to be responsible for part of the insult-induced cell damage manifested in increased LDH release. Pervanadate, an inhibitor of the phosphotyrosine phosphatases (PTPs), abrogated the inactivation of SFKs and attenuated cell injury, indicating that insult-induced activation of PTPs is involved in SFKs inhibition and the ensued damage. The inhibition of SFKs and FAK is probably the cause of the disassembling of SFKs–FAK complexes, a process known to be associated with apoptosis.     

Sodium, Calcium and Late Potassium Currents are Reduced in Cerebellar Granule Cells Cultured in the Presence of a Protein Complex Conferring Resistance to Excitatory Amino Acids

Whole-cell, patch-clamp recordings were used to study voltage-gated currents generated by cerebellar granule cells that were cultured in medium containing either 10% fetal calf serum (hereafter termed S + granules) or neurite outgrowth and adhesion complex (NOAC, hereafter called NOAC granules). NOAC is a protein complex found in rabbit serum that renders granules resistant to the excitotoxic action of excitatory amino acids. During depolarizing commands both S+ and NOAC granules generated Na⁺ and Ca²⁺ inward currents and an early and a late K⁺ outward currents. However, Na⁺ and Ca²⁺ Inward currents and late outward K⁺ currents recorded in NOAC granules were smaller than those seen in S+ granules. Furthermore, although of similar amplitude, early K⁺ currents displayed different kinetics in the two types of neurons. Thus, these data demonstrate that the electrophysiological properties of cerebellar granules, and probably of other neuronal populations, depend upon serum components and raise the possibility that an analogous modulation might be operative in vivo, and play a role in development, synaptic plasticity or neuropathological processes.     

Meta-Analysis to Assess the Quality of International Normalized Ratio Control and Associated Outcomes in Venous Thromboembolism Patients

Introduction

Patients with venous thromboembolism (VTE) frequently require vitamin K antagonists (VKAs) to prevent recurrent events, but their use increases hemorrhage risk. We performed a meta-analysis to assess the quality of international normalized ratio (INR) control, identify study-level predictors of poor control and to examine the relationship between INR control and adverse outcomes in VTE patients.

Materials and Methods

We searched bibliographic databases (1990-June 2013) for studies of VTE patients receiving adjusted-dose VKAs that reported time in range (2.0-3.0) or proportion of INRs in range and/or reported INR measurements coinciding with thromboembolic or hemorrhagic events. Meta-analysis and meta-regression analysis was performed.

Results

Upon meta-analysis, studies found 59% (95%CI: 54-64%) of INRs measured and 61% (95%CI: 59-63%) of the time patients were treated were spent outside the target range of 2.0-3.0; with a tendency for under- versus over-anticoagulation. Moreover, this poor INR control resulted in a greater chance of recurrent VTE (beta-coefficient = -0.46, p = 0.01) and major bleeding (beta-coefficient = -0.30, p = 0.02). Patients with an INR < 2.0 made up 58% (95%CI: 39-77%) of VTE cases, while those with an INR > 3.0 made up 48% (95%CI: 34-61%) of major hemorrhage cases. Upon meta-regression, being VKA-naïve (-14%, p = 0.04) and treated in the community (-7%, p < 0.001) were associated with less time in range, while being treated in Europe/United Kingdom (compared to North America) was associated with (11%, p = 0.003) greater time.

Conclusions

Strategies to improve INR control or alternative anticoagulants, including the newer oral agents, should be widely implemented in VTE patients to reduce the rate of recurrent events and bleeding.     

Role of Liver and Plasma Lipoproteins in Selective Transport of n-3 Fatty Acids to Tissues: A Comparative Study of <Superscript>14</Superscript>C-DHA and <Superscript>3</Superscript>H-Oleic Acid Tracers

We conducted a study aimed at a direct comparison of the plasma dynamics and uptake of docosahexaenoic (DHA) and oleic (OA) fatty acids by various organs. ¹⁴C-DHA and ³H-OA were intravenously co-injected into mice. At 5 min after injection, more than 40% of the ¹⁴C-DHA, but less than 20% of the ³H-OA, labels was associated with the liver. Heart uptake of ¹⁴C-DHA was three to four times greater compared to the ³H-OA label. Brain incorporation of ¹⁴C-DHA slowly rose to 0.7% at 24 h, but it remained at the 1–1.5% level for ³H-OA. Total ¹⁴C activity in plasma reached 2% of the injected dose at 20 min and leveled off at 0.5% after 1.5 h. Fifteen percent of ¹⁴C-DHA plasma activity at 30 min was associated with non-esterified fatty acids, whereas about 85% was recovered in triglycerides in very low-density lipoprotein (VLDL) and LDL fractions. Only 30% of ³H-OA derived activity was found in the VLDL fraction at 30 min. All ³H activity in plasma at later time points was in catabolite fractions. These findings demonstrate that liver plays an important role in the initial selectivity for DHA. It is likely that DHA is specifically taken up by liver, esterified, loaded into lipoproteins, and then delivered to brain, heart, and other target tissues.     

Increased thrombin generation in splanchnic vein thrombosis is related to the presence of liver cirrhosis and not to the thrombotic event

Introduction

In recent years there have been increasing evidence associating liver disease with hypercoagulability, rather than bleeding. The aim of the study was to evaluate the haemostatic potential in patients with liver disease.

Patients and methods

We measured thrombin generation in the presence and absence of thrombomodulin in patients with portal vein thrombosis (PVT, n = 47), Budd-Chiari syndrome (BCS, n = 15) and cirrhosis (n = 24) and compared the results to those obtained from healthy controls (n = 21). Fifteen patients with PVT and 10 patients with BCS were treated with warfarin and were compared to an equal number of patients with atrial fibrillation matched for prothrombin time-international normalized ratio. We assessed resistance to thrombomodulin by using ratios [marker measured in the presence/absence of thrombomodulin].

Results

There were no differences in thrombin generation between patients on warfarin treatment and their controls. Cirrhotic patients generated more thrombin in the presence of thrombomodulin and exhibited thrombomodulin resistance compared to controls [p = 0.006 for endogenous thrombin potential (ETP) and p < 0.001 for peak thrombin and both ratios ETP and peak] and patients with non-cirrhotic PVT (p = 0.001, p = 0.006, p < 0.001, p < 0.001 for ETP, peak, ratio ETP, ratio peak, respectively). The patients with cirrhotic PVT exhibited higher ETP (p = 0.044) and peak (p = 0.02) in the presence of thrombomodulin than controls, as well as thrombomodulin resistance (ETP and peak ratios: p = 0.001).

Conclusions

Hypercoagulability and thrombomodulin resistance in patients with cirrhosis were independent of the presence of splanchnic vein thrombosis. The hypercoagulability in patients with cirrhotic PVT could have implications for considering longer or more intensive treatment with anticoagulants in this group.     

The international normalized ratio according to Owren in liver disease: Interlaboratory assessment and determination of international sensitivity index

Introduction

The international normalized ratio (INR) is used to prioritize liver disease patients for transplantation. Previous studies have shown high interlaboratory variability in Quick-based INR determinations in samples of patients with liver disease. We assessed Owren-based INR reagents for analyzing INR in patients with liver disease. Further, we determined the difference between international sensitivity index (ISI) for patients on vitamin K antagonists (ISI_VKA) and ISI for patients with liver disease (ISI_liver).

Patients and Methods

Twenty patients with liver disease were included, 10 with INR 1.8-3.6 (group A1) and 10 with INR 1.2-1.5 (group C1). Plasma from these patients was analyzed for Owren-based INR in eight Swedish laboratories using either of following reagents: SPA +, Owrens PT or Nycotest PT. To determine ISI liver, the reference thromboplastin RBT/05 and additional 41 patients with liver disease and 20 normal controls were included. ISI_VKA was determined according to the WHO procedure. The difference between the ISI_VKA and ISI_liver was calculated.

Results

The coefficients of variance for the Owren based INR methods were 6.2% in group A1, 3.9 % in group C1 and 5.3% for all patients. The difference between ISI_VKA and ISI_liver were -0.4%, -0.7% and -0.2% for SPA +, Owrens PT and Nycotest PT respectively.

Conclusions

Interlaboratory variation in INR analyses according to Owren in patients with liver disease is low and the difference between ISI_VKA and ISI_liver is below 10% with this method. ISI_VKA can therefore be used in the INR calibration, for the Owren reagents studied, when analyzing plasma from patients with liver disease.