Brain mitochondrial metabolic dysfunction and glutamate level reduction in the pilocarpine model of temporal lobe epilepsy in mice

Although certain metabolic characteristics such as interictal glucose hypometabolism are well established for temporal lobe epilepsy (TLE), its pathogenesis still remains unclear. Here, we performed a comprehensive study of brain metabolism in a mouse model of TLE, induced by pilocarpine–status epilepticus (SE). To investigate glucose metabolism, we injected mice 3.5–4 weeks after SE with [1,2-¹³C]glucose before microwave fixation of the head. Using ¹H and ¹³C nuclear magnetic resonance spectroscopy, gas chromatography—mass spectrometry and high-pressure liquid chromatography, we quantified metabolites and ¹³C labeling in extracts of cortex and hippocampal formation (HF). Hippocampal levels of glutamate, glutathione and alanine were decreased in pilocarpine–SE mice compared with controls. Moreover, the contents of N-acetyl aspartate, succinate and reduced nicotinamide adenine dinucleotide (phosphate) NAD(P)H were decreased in HF indicating impairment of mitochondrial function. In addition, the reduction in ¹³C enrichment of hippocampal citrate and malate suggests decreased tricarboxylic acid (TCA) cycle turnover in this region. In cortex, we found reduced ¹³C labeling of glutamate, glutamine and aspartate via the pyruvate carboxylation and pyruvate dehydrogenation pathways, suggesting slower turnover of these amino acids and/or the TCA cycle. In conclusion, mitochondrial metabolic dysfunction and altered amino-acid metabolism is found in both cortex and HF in this epilepsy model.     

Amphiphilic Block Copolymers Containing Regioregular Poly(3‐hexylthiophene) and Poly(2‐ethyl‐2‐oxazoline)

Poly(3‐hexylthiophene)‐block‐poly(2‐ethyl‐2‐oxazoline) amphiphilic rod–coil diblock copolymers have been synthesized by a combination of Grignard metathesis (GRIM) and ring‐opening cationic polymerization. Diblock copolymers containing 5, 15, and 30 mol‐% poly(2‐ethyl‐2‐oxazoline) have been synthesized and characterized. The synthesized rod–coil block copolymers display nanofibrillar morphology where the density of the nanofibrills is dependent on the concentration of the poly(2‐ethyl‐2‐oxazoline) coil segment. The conductivity of the diblock copolymers was lowered from 200 to 35 S · cm^?1 with an increase in the content of the insulating poly(2‐ethyl‐2‐oxazoline) block. By contrast, the field‐effect mobility decreased by 2–3 orders of magnitude upon the incorporation of the poly(2‐ethyl‐2‐oxazoline) insulating segment.

     

Health care use,drug treatment and comorbidity in patients with schizophrenia or non-affective psychosis in Sweden: a cross-sectional study

Background

This study investigated the prevalence of schizophrenia (ICD-10 F 20) and of other non-affective psychosis (NAP, ICD-10 F 21 - F 29) in Sweden. It further assessed health care use, comorbidity and medication for these patient groups.Most studies either have a study population of patients with strictly defined schizophrenia or a psychosis population of which strict schizophrenia cases form a smaller set. The present study permits comparison of the two mutually exclusive patient groups using data at the individual level in the diagnosis of non-affective psychosis, use of health care, medical treatment and comorbidity by diagnosis or medical treatment.

Methods

In 2012, data were extracted from a regional registry containing patient-level data on consultations, hospitalisations, diagnoses and dispensed drugs for the total population in the region of Stockholm (2.1 million inhabitants). The size of the total psychosis population was 18,769, of which 7284 had a diagnosis of schizophrenia. Crude prevalence rates and risk rates with 95% confidence intervals were calculated.

Results

In 2012, the prevalence of schizophrenia and NAP was 3.5/1000 and 5.5/1000, respectively. Schizophrenia was most common among patients aged 50–59 years and NAP most common among patients aged 40–49 years.Schizophrenia patients used psychiatric health care more often than the NAP patients but less overall inpatient care (78.6 vs. 60.0%).The most prevalent comorbidities were substance abuse/dependence (7.9% in the schizophrenia group vs. 11.7% in the NAP group), hypertension (7.9 vs. 9.7%) and diabetes (6.9 vs. 4.8%).The parenteral form of long-acting injectable antipsychotics was more often dispensed to patients with schizophrenia (10 vs. 2%).

Conclusions

This study, analysing all diagnoses recorded in a large health region, confirmed prevalence rates found in previous studies. Schizophrenia patients use more psychiatric and less overall inpatient health care than NAP patients. Differences between the two patient groups in comorbidity and drug treatment were found. The registered rates of a substance abuse/dependence diagnosis were the most common comorbidity observed among the patients investigated. The observed differences between the schizophrenia and the NAP patients in health care consumption, comorbidity and drug treatment are relevant and warrant further studies.

     

Feasibility and Acceptability of a Healthy Nordic Diet Intervention for the Treatment of Depression: A Randomized Controlled Pilot Trial

Healthy diet interventions have been shown to improve depressive symptoms, but there is a need for randomized controlled trials (RCTs) that are double blind and investigate biological mechanisms. The primary objectives of this randomized controlled pilot trial were to test the palatability of the meals and the acceptability of the intervention in preparation for an 8-week RCT in the future, which will investigate whether a healthy Nordic diet improves depressive symptoms in individuals with major depressive disorder, and associated biological mechanisms. Depressed (n = 10) and non-depressed (n = 6) women and men were randomized to receive either a healthy Nordic diet (ND) or a control diet (CD) for 8 days. Participants were blinded to their diet allocation and the study hypotheses. Health questionnaires were completed before and after the intervention and, throughout the study, questionnaires assessed participants’ liking for the meals, their sensory properties, adherence, and open-ended feedback. In the ND group, 75% of participants consumed only the provided foods, as instructed, compared to 50% of CD participants. The meals of both diets, on average, received good ratings for liking and sensory properties, though the ND ratings were somewhat higher. Overall, results were positive and informative, indicating that the planned RCT will be feasible and well-accepted, with some proposed modifications.     

Synthesis of Di‐block Copolymers Containing Regioregular Poly(3‐hexylthiophene) and Poly(tetrahydrofuran) by a Combination of Grignard Metathesis and Cationic Polymerizations

Poly(3‐hexylthiophene)‐block‐poly(tetrahydrofuran) was synthesized by cationic ring‐opening polymerization of tetrahydrofuran (THF) using a poly(3‐hexylthiophene) macroinitiator. Poly(3‐hexylthiophene) macroinitiator used for the ring‐opening polymerization of THF was synthesized by reacting the hydroxypropyl end‐group with trifluoromethanesulfonic anhydride in the presence of 2,6‐di‐tert‐butylpyridine. ¹H NMR spectroscopy and SEC data confirmed the formation of the di‐block copolymers. Field‐effect mobility of poly(3‐hexylthiophene)‐block‐poly(tetrahydrofuran) was measured in a thin‐film transistor configuration and was found to be 0.009 cm² · V^?1 · s^?1.

     

Paired pulse analysis of ATP and noradrenaline release from sympathetic nerves of rat tail artery and mouse vas deferens: effects of K+ channel blockers

1. The paired pulse stimulus paradigm – two pulses of equal strength delivered at variable interpulse intervals – was used to study the release of ATP and noradrenaline (NA) from post ganglionic sympathetic nerves of rat tail artery and mouse vas deferens.
2. Excitatory junction currents (EJCs) were used to measure the release of ATP, and differential pulse amperometry to measure that of NA.
3. At interpulse intervals of 0.1–1 s paired pulse stimulation caused an increase in the size of the second EJC, both in rat tail artery and mouse vas deferens. As the interpulse interval was increased to 10 s or more, the two EJCs became of equal size.
4. In both preparations the K⁺ channel blockers tetraethylammonium (TEA, 20 mM) and 4-aminopyridine (4-AP, 1 mM) prolonged the duration of the nerve terminal spike and greatly amplified the first EJC of the pair.
5. In the presence of TEA and 4-AP in rat tail artery paired pulse stimulation caused a dramatic depression of the second EJC without markedly affecting the nerve terminal spike. The depression of the second EJC decreased with increasing interpulse intervals, and also when external Ca²⁺ was reduced to 0.2 mM. In mouse vas deferens, TEA and 4-AP caused only a modest depression of the second EJC.
6. In rat tail artery in the presence of TEA and 4-AP paired pulse stimulation caused a depression of the NA oxidation current evoked by the second pulse, which was similar in magnitude and time course to that of the EJC. Similar TEA and 4-AP induced depression of the second pulse response was also observed when the purinergic and noradrenergic components of the contractile response were investigated.
7. The results show that in rat tail artery K⁺ channel blockers cause a dramatic paired pulse depression of the release of ATP and NA. The similarity in the depression of the EJC, the NA oxidation current, and the purinergic and noradrenergic components of the contractile response is compatible with the hypothesis that ATP and NA are released in parallel from the same neuronal sources.

     

Characterization of glucose‐related metabolic pathways in differentiated rat oligodendrocyte lineage cells

Although oligodendrocytes constitute a significant proportion of cells in the central nervous system (CNS), little is known about their intermediary metabolism. We have, therefore, characterized metabolic functions of primary oligodendrocyte precursor cell cultures at late stages of differentiation using isotope‐labelled metabolites. We report that differentiated oligodendrocyte lineage cells avidly metabolize glucose in the cytosol and pyruvate derived from glucose in the mitochondria. The labelling patterns of metabolites obtained after incubation with [1,2‐¹³C]glucose demonstrated that the pentose phosphate pathway (PPP) is highly active in oligodendrocytes (approximately 10% of glucose is metabolized via the PPP as indicated by labelling patterns in phosphoenolpyruvate). Mass spectrometry and magnetic resonance spectroscopy analyses of metabolites after incubation of cells with [1‐¹³C]lactate or [1,2‐¹³C]glucose, respectively, demonstrated that anaplerotic pyruvate carboxylation, which was thought to be exclusive to astrocytes, is also active in oligodendrocytes. Using [1,2‐¹³C]acetate, we show that oligodendrocytes convert acetate into acetyl CoA which is metabolized in the tricarboxylic acid cycle. Analysis of labelling patterns of alanine after incubation of cells with [1,2‐¹³C]acetate and [1,2‐¹³C]glucose showed catabolic oxidation of malate or oxaloacetate. In conclusion, we report that oligodendrocyte lineage cells at late differentiation stages are metabolically highly active cells that are likely to contribute considerably to the metabolic activity of the CNS. GLIA 2016;64:21–34     

In-vitro antimicrobial activity screening of some ethnoveterinary medicinal plants traditionally used against mastitis,wound and gastrointestinal tract complication in Tigray Region,Ethiopia

Objective

To screen the antibacterial activity of nine ethnoveterinary plants traditionally used for the treatment of mastitis, wound and gastrointestinal complications.

Methods

Hydroalcoholic exctracts of medicinal plants namely, Achyranthes aspera (A. aspera) L. (Family Asparagaceae), Ficus caria (F. caria) (Family Moraceae), Malvi parviflora (M. parviflora) (Family Malvaceae), Vernonia species (V. species) (local name Alakit, Family Asteraceae), Solanum hastifolium (S. hastifolium) (Family Solanaceae), Calpurinia aurea (C. aurea) (Ait) Benth (Family Fabaceae), Nicotiana tabacum (N. tabacum) L. (Family Solanaceae), Ziziphus spina-christi (Z. spina-christi) (Family Rhamnaceae), Croton macrostachys (C. macrostachys) (Family Euphorbiaceae), were screened against clinical bacterial isolates of veterinary importance from October 2007 to April 2009. The antibacterial activity was tested using disc diffusion at two concentrations (200 mg/mL and 100 mg/mL) and broth dilution methods using 70% methanol macerated leaf extracts.

Results

With the exception of S. hastifolium all plant extracts exhibited antibacterial activity. Among the medicinal plants tested C. aurea, C. macrostachyus, A. aspera, N. tabacum and vernonia species (Alakit) showed the most promising antimicrobial properties.

Conclusions

It can be concluded that many of the tested plants have antibacterial activity and supports the traditional usage of the plants for mastitis, wound and gastrointestinal complications treatment. Further studies into their toxicity and phytochemistry is advocated.