Intracellular Organization: Evolutionary Origins and Possible Consequences to Metabolic Rate Control in Vertebrates

We adopt the position that metabolism originated at (or near)mineral surfaces prior to the origin of the first cells. Basedon current views of the organization of contemporary animalcells we speculate that the metabolism of the immediate ancestorsof eukaryotic cells required these non-biological surfaces,but that the latter were subsequently replaced by membranes,and nuclear and cytoplasmic matrix proteins which, we argue,remain as required participants in the intermediary metabolismof contemporary eukaryotic cells. The idea that such an lntracellularorganization could have provided a fundamental means by whichto control metabolic rate at the level of the intact animalis considered next. In the case of vertebrates we suggest thatthe organismic level of control might operate throughthe rateof capillary blood flow, as proposed in the Flow Theory of Coulson(1986): by controlling the rate at which the organized enzymearrays within the cells are perfused with substrate, cellularmetabolic rates could be set throughout the organism in an integratedfashion. Although there are problems with this linkage the interestingpossibility arises that the metabolic rate of individual cellsmay be subservient to the organism, being driven not so muchby the well known intracellular controls of concentration-based-biochemistryas by the flow of nutrients through the cells.     

A Metabolic Biofuel Cell: Conversion of Human Leukocyte Metabolic Activity to Electrical Currents

An investigation of the electrochemical activity of human white blood cells (WBC) for biofuel cell (BFC) applications is described. WBCs isolated from whole human blood were suspended in PBS and introduced into the anode compartment of a proton exchange membrane (PEM) fuel cell. The cathode compartment contained a 50 mM potassium ferricyanide solution. Average current densities between 0.9 and 1.6 μA cm^-2 and open circuit potentials (V_oc) between 83 and 102 mV were obtained, which were both higher than control values. Cyclic voltammetry was used to investigate the electrochemical activity of the activated WBCs in an attempt to elucidate the mechanism of electron transfer between the cells and electrode. Voltammograms were obtained for the WBCs, including peripheral blood mononuclear cells (PBMCs - a lymphocyte-monocyte mixture isolated on a Ficoll gradient), a B lymphoblastoid cell line (BLCL), and two leukemia cell lines, namely K562 and Jurkat. An oxidation peak at about 363 mV vs. SCE for the PMA (phorbol ester) activated primary cells, with a notable absence of a reduction peak was observed. Oxidation peaks were not observed for the BLCL, K562 or Jurkat cell lines. HPLC confirmed the release of serotonin (5-HT) from the PMA activated primary cells. It is believed that serotonin, among other biochemical species released by the activated cells, contributes to the observed BFC currents.     

Cytoprotective Effects of Grape Seed Extract on Human Gingival Fibroblasts in Relation to Its Antioxidant Potential

Cytoprotective effects of short-term treatment with grape seed extract (GSE) upon human gingival fibroblasts (hGFs) were evaluated in relation to its antioxidant properties and compared with those of a water-soluble analog of vitamin E: trolox (Tx). GSE and Tx showed comparable antioxidant potential in vitro against di(phenyl)-(2,4,6-trinitrophenyl)iminoazanium (DPPH; a stable radical), hydroxyl radical (^•OH), singlet oxygen (¹O₂), and hydrogen peroxide (H₂O₂). Pretreatment or concomitant treatment with GSE for 1 min protected hGFs from oxidative stressors, including H₂O₂, acid-electrolyzed water (AEW), and ¹O₂, and attenuated the intracellular formation of reactive oxygen species induced by H₂O₂ and AEW. Tx also reduced the H₂O₂- and AEW-induced intracellular formation of reactive oxygen species, but showed no cytoprotective effects on hGFs exposed to H₂O₂, AEW, or ¹O₂. These results suggest that the cytoprotective effects of GSE are likely exerted independently of its antioxidant potential.     

Antioxidant Defences under Hyperoxygenic and Hyperosmotic Conditions in Leaves of Two Lines of Maize with Differential Sensitivity to Drought

The effects of hyperoxygenic and hyperosmotic stress on severalaspects of antioxidant defences were studied in the leaves ofa drought-sensitive (LG11) and a drought-tolerant (LIZA) lineof maize (Zea mays L.). When leaf disks were subjected to theseverest stress conditions (100% O₂ and 0.5 M mannitol), theactivities of antioxidant enzymes, such as superoxide dismutase(SOD), catalase (Cat), ascorbate peroxidase (Asc-Px) and glutathionereductase (GSSG-Red), remained higher in disks of LIZA thanin disks of LG11. The ratios of activities of SOD to Cat, SODto Asc-Px and SOD to GSSG-Red were much higher in leaf disksfrom LG11 than in those from LIZA. Damage, as indicated by,for example, the extend of lipid peroxidation, the destructionof chlorophyll and carotenoids, the decrease in levels of proteinsulfhydryl groups and the leakage of electrolytes from cellswas apparent in leaf disks of both LIZA and LG11 as consequenceof the applied stresses. However, the damage was less markedin LIZA than in LG11. (Received September 2, 1992; Accepted July 20, 1993)     

Increased Levels of Sphingosylphosphorylcholine (SPC) in Plasma of Metabolic Syndrome Patients

Recent developments in lipid mass spectrometry enable extensive lipid class and species analysis in metabolic disorders such as diabesity and metabolic syndrome. The minor plasma lipid class sphingosylphosphorylcholine (SPC) was identified as a ligand for lipid sensitive G-protein coupled receptors playing a key role in cell growth, differentiation, motility, calcium signaling, tissue remodeling, vascular diseases and cancer. However, information about its role in diabesity patients is sparse. In this study, we analyzed plasma lipid species in patients at risk for diabesity and the metabolic syndrome and compared them with healthy controls. Our data show that SPC is significantly increased in plasma samples from metabolic syndrome patients but not in plasma from patients at risk for diabesity. Detailed SPC species analysis showed that the observed increase is due to a significant increase in all detected SPC subspecies. Moreover, a strong positive correlation is observed between total SPC and individual SPC species with both body mass index and the acute phase low grade inflammation marker soluble CD163 (sCD163). Collectively, our study provides new information on SPC plasma levels in metabolic syndrome and suggests new avenues for investigation.     

Pharmacogenetic Analysis of Pediatric Patients with Acute Lymphoblastic Leukemia: A Possible Association between Survival Rate and ITPA Polymorphism

Genetic polymorphisms are important factors in the effects and toxicity of chemotherapeutics. To analyze the pharmacogenetic and ethnic differences in chemotherapeutics, major genes implicated in the treatment of acute lymphoblastic leukemia (ALL) were analyzed. Eighteen loci of 16 genes in 100 patients with ALL were analyzed. The distribution of variant alleles were CYP3A4*1B (0%), CYP3A5*3 (0%), GSTM1 (21%), GSTP1 (21%), GSTT1 (16%), MDR1 exon 21 (77%), MDR1 exon 26 (61%), MTHFR 677 (63%), MTHFR 1298 (29%), NR3C1 1088 (0%), RFC1 80 (68%), TPMT combined genotype (7%), VDR intron 8 (11%), VDR FokI (83%), TYMS enhancer repeat (22%) and ITPA 94 (30%). The frequencies of single nucleotide polymorphisms (SNPs) of 10 loci were statistically different from those in Western Caucasians. Dose percents (actual/planned dose) or toxicity of mercaptopurine and methotrexate were not related to any SNPs. Event free survival (EFS) rate was lower in ITPA variants, and ITPA 94 AC/AA variant genotypes were the only independent risk factor for lower EFS in multivariate analysis, which was a different pharmacogenetic implication from Western studies. This study is the first pharmacogenetic study in Korean pediatric ALL. Our result suggests that there are other possible pharmacogenetic factors besides TPMT or ITPA polymorphisms which influence the metabolism of mercaptopurine in Asian populations.     

APOA-I: A Possible Novel Biomarker for Metabolic Side Effects in First Episode Schizophrenia

The purpose of this study was to investigate the change in plasma protein expression in first episode schizophrenia after an 8-week treatment with risperidone, and to explore potential biomarkers for metabolic side effects associated with risperidone treatment. Eighty first-episode schizophrenia patientswere enrolled in the study. Fifteen of the 80 patients were randomly selected to undergo proteomic analysis. Plasma proteins were obtained before and after the 8-week risperidone treatment, and measured using two-dimensional gel electrophoresis (2-DE), Matrix-Assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry(MALDI-TOF/TOF) and peptide mass fingerprinting.Proteins with the highest fold changes after risperidone treatment were then measured for all 80 patients using enzyme linked immunosorbent assay (ELISA). The relationship between changes in plasma protein levels and changes in metabolic parameters after risperidone treatment was examined. In 15 randomly selected patients, approximately 1,500 protein spots were detected in each gel by 2-DE. Of those proteins, 22 spots showed significant difference in abundance after risperidone treatment (p''s<0.05). After MALDI-TOF peptide mass fingerprinting, apolipoprotein A-I (APOA-I) and Guanine Nucleotide Binding Protein, Alpha Stimulating (GNAS), were found to have the highest fold changes.The content of APOA-I was significantly increased, and the content of GNAS was significantly decreased after risperidone treatment (p''s<0.05). The analysis in the entire study sample showed similar findings in changes of APOA-I and GNAS after risperidone treatment. Further analysis showed significant relationships between changesin APOA-1 and changes in triglyceride, total cholesterol, and body mass index after controlling for age, gender and family history of diabetes. Similar analysis showed a trend positive relationship between changes in GNAS and changes in BMI. Using proteomic analysis, the study suggested that APOA-I might be a novel biomarkers related to metabolic side effects in first episode schizophrenia treated with risperidone.     

Dating of Pregnancy in First versus Second Trimester in Relation to Post-Term Birth Rate: A Cohort Study

Objectives

To evaluate in a national standardised setting whether the performance of ultrasound dating during the first rather than the second trimester of pregnancy had consequences regarding the definition of pre- and post-term birth rates.

Methods

A cohort study of 8,551 singleton pregnancies with spontaneous delivery was performed from 2006 to 2012 at Copenhagen University Hospital, Holbæk, Denmark. We determined the duration of pregnancy calculated by last menstrual period, crown rump length (CRL), biparietal diameter (1^st trimester), BPD (2^nd trimester), and head circumference and compared mean and median durations, the mean differences, the systematic discrepancies, and the percentages of pre-term and post-term pregnancies in relation to each method. The primary outcomes were post-term and pre-term birth rates defined by different dating methods.

Results

The change from use of second to first trimester measurements for dating was associated with a significant increase in the rate of post-term deliveries from 2.1–2.9% and a significant decrease in the rate of pre-term deliveries from 5.4–4.6% caused by systematic discrepancies. Thereby 25.1% would pass 41 weeks when GA is defined by CRL and 17.3% when BPD (2^nd trimester) is used. Calibration for these discrepancies resulted in a lower post-term birth rate, from 3.1–1.4%, when first compared to second trimester dating was used.

Conclusions

Systematic discrepancies were identified when biometric formulas were used to determine duration of pregnancy. This should be corrected in clinical practice to avoid an overestimation of post-term birth and unnecessary inductions when first trimester formulas are used.     

Selenium, Zinc, and Copper Plasma Levels in Patients with Schizophrenia: Relationship with Metabolic Risk Factors

The aim of this study was to determine the plasma selenium (Se), copper (Cu), and zinc (Zn) levels and to evaluate their possible association with metabolic syndrome (MetS) components in patients with schizophrenia. The study group consisted of 60 patients with schizophrenia and 60 sex- and age-matched healthy controls. Anthropometric measurements, blood pressure, and biochemical analysis of fasting blood were performed in all subjects. Patients with schizophrenia had significantly higher plasma Cu concentrations compared with controls (0.97?±?0.31 vs. 0.77?±?0.32 mg/L, p?=?0.001). The plasma Cu concentration showed a positive correlation with plasma glucose and diastolic blood pressure in the patient groups (r _s ?=?0.263, p?<?0.05 and r _s ?=?0.272, p?<?0.05, respectively). The plasma Se level correlated positive with MetS score (r _s ?=?0.385, p?<?0.01), waist circumference (r _s ?=?0.344, p?<?0.05), plasma glucose (r _s ?=?0.319, p?<?0.05), and triglyceride concentrations (r _s ?=?0.462, p?<?0.001) in patients with schizophrenia. Plasma Zn did not correlate with any of the MetS components. These results suggest that alterations in plasma Cu and Se levels in medicated patients with schizophrenia could be associated with metabolic risk factors.     

To Supplement or Not to Supplement: A Metabolic Network Framework for Human Nutritional Supplements

Flux balance analysis and constraint based modeling have been successfully used in the past to elucidate the metabolism of single cellular organisms. However, limited work has been done with multicellular organisms and even less with humans. The focus of this paper is to present a novel use of this technique by investigating human nutrition, a challenging field of study. Specifically, we present a steady state constraint based model of skeletal muscle tissue to investigate amino acid supplementation''s effect on protein synthesis. We implement several in silico supplementation strategies to study whether amino acid supplementation might be beneficial for increasing muscle contractile protein synthesis. Concurrent with published data on amino acid supplementation''s effect on protein synthesis in a post resistance exercise state, our results suggest that increasing bioavailability of methionine, arginine, and the branched-chain amino acids can increase the flux of contractile protein synthesis. The study also suggests that a common commercial supplement, glutamine, is not an effective supplement in the context of increasing protein synthesis and thus, muscle mass. Similar to any study in a model organism, the computational modeling of this research has some limitations. Thus, this paper introduces the prospect of using systems biology as a framework to formally investigate how supplementation and nutrition can affect human metabolism and physiology.     

Plasma Metabolomics in Human Pulmonary Tuberculosis Disease: A Pilot Study

We aimed to characterize metabolites during tuberculosis (TB) disease and identify new pathophysiologic pathways involved in infection as well as biomarkers of TB onset, progression and resolution. Such data may inform development of new anti-tuberculosis drugs. Plasma samples from adults with newly diagnosed pulmonary TB disease and their matched, asymptomatic, sputum culture-negative household contacts were analyzed using liquid chromatography high-resolution mass spectrometry (LC-MS) to identify metabolites. Statistical and bioinformatics methods were used to select accurate mass/charge (m/z) ions that were significantly different between the two groups at a false discovery rate (FDR) of q<0.05. Two-way hierarchical cluster analysis (HCA) was used to identify clusters of ions contributing to separation of cases and controls, and metabolomics databases were used to match these ions to known metabolites. Identity of specific D-series resolvins, glutamate and Mycobacterium tuberculosis (Mtb)-derived trehalose-6-mycolate was confirmed using LC-MS/MS analysis. Over 23,000 metabolites were detected in untargeted metabolomic analysis and 61 metabolites were significantly different between the two groups. HCA revealed 8 metabolite clusters containing metabolites largely upregulated in patients with TB disease, including anti-TB drugs, glutamate, choline derivatives, Mycobacterium tuberculosis-derived cell wall glycolipids (trehalose-6-mycolate and phosphatidylinositol) and pro-resolving lipid mediators of inflammation, known to stimulate resolution, efferocytosis and microbial killing. The resolvins were confirmed to be RvD1, aspirin-triggered RvD1, and RvD2. This study shows that high-resolution metabolomic analysis can differentiate patients with active TB disease from their asymptomatic household contacts. Specific metabolites upregulated in the plasma of patients with active TB disease, including Mtb-derived glycolipids and resolvins, have potential as biomarkers and may reveal pathways involved in TB disease pathogenesis and resolution.     

Positron Emission Tomography of the Human Brain in Relation to Psychological Defense Mechanisms in Patients with Multiple Sclerosis

Neurophysiological correlates of psychological defense mechanisms (PDMs) were studied in patients with multiple sclerosis. PDM scores (the Lifestyle Index test) were compared with the relative glucose metabolic rate (GMR) estimated by positron emission tomography. The results testified that the combined metabolic activity of the limbic system and the frontal and temporal brain areas of the right hemisphere plays a predominant role in the functioning of the PDM system. An increase or decrease in PDM activity was associated with changes in GMR in several brain structures of the parietal and frontal regions.