Design,synthesis and structure–activity relationships of zwitterionic spirocyclic compounds as potent CCR1 antagonists

A series of zwitterionic spirocyclic compounds were synthesised. In vitro data revealed that these compounds were potent CCR1 antagonists. In particular, 2, 4, 11 and 20 inhibited CCR1 mediated chemotaxis of THP-1 cells in a functional assay.     

Nitrification exhibits Haldane kinetics in an agricultural soil treated with ammonium sulfate or dairy-waste compost

An agricultural soil was treated with dairy-waste compost, ammonium-sulfate fertilizer or no added nitrogen (control) and planted to silage corn for 6 years. The kinetics of nitrification were determined in laboratory-shaken slurry assays with a range of substrate concentrations (0-20 mM NH(4)(+)) over a 24-h period for soils from the three treatments. Determined concentrations of substrate and product were fit to Michaelis-Menten and Haldane models. For all the treatments, the Haldane model was a better fit, suggesting that significant nitrification inhibition may occur in soils under high ammonium conditions similar to those found immediately after fertilization or waste applications. The maximum rate of nitrification (V(max)) was significantly higher for the fertilized and compost-treated soils (1.74 and 1.50 mmol N kg(-1) soil day(-1)) vs. control soil (0.98 mmol kg(-1) soil day(-1)). The K(m) and K(i) values were not significantly different, with average values of 0.02 and 27 mM NH(4)(+), respectively. Our results suggest that both N sources increased nitrifier community size, but did not shift the nitrifier community structure in ways that influenced enzyme affinity or sensitivity to ammonium. The K(m) values are comparable to those determined directly in other soils, but are substantially lower than those from most pure cultures of ammonia-oxidizing bacteria.     

CD4 Cell Count Trends after Commencement of Antiretroviral Therapy among HIV-Infected Patients in Tigray,Northern Ethiopia: A Retrospective Cross-Sectional Study

Background

The rate and extent of CD4 cell recovery varies widely among HIV-infected patients with different baseline CD4 cell count strata. The objective of the study was to assess trends in CD4 cell counts in HIV-infected patients after initiation of antiretroviral therapy in Tigray, Northern Ethiopia.

Methods

A retrospective cross-sectional study was conducted by reviewing medical records of HIV patients who received antiretroviral treatment at twenty health centers in Tigray region during 2008–2012. Multi-stage cluster sampling technique was employed to collect data, and the data were analyzed using SPSS version 20.0 software.

Results

The median change from baseline to the most recent CD4 cell count was +292 cells/μl. By 5 years, the overall median (inter-quartile range, IQR) CD4 cell count was 444(263-557) cells/μl while the median (IQR) CD4 cell count was 342(246-580) cells/μl among patients with baseline CD4 cell counts ≤200 cells/μl, 500(241-557) cells/μl among those with baseline CD4 cell counts of 201–350 cells/μl, and 652(537-767) cells/μl among those with baseline CD4 cell counts >350 cells/μl. Higher baseline CD4 cell counts and being male were independently associated with the risk of immunological non-response at 12 months. Furthermore, it was also investigated that these factors were significant predictors of subsequent CD4 cell recovery.

Conclusions

Patients with higher baseline CD4 cell stratum returned to normal CD4 Cell counts though they had an increased risk of immunological non-response at 12 months compared to those with the least baseline CD4 cell stratum. The findings suggest that consideration be given to initiation of HAART at a CD4 cell count >350 cells/μl to achieve better immune recovery, and to HIV-infected male patients to improve their health seeking behavior.     

Why Do Women Deliver at Home? Multilevel Modeling of Ethiopian National Demographic and Health Survey Data

Background

Despite of the existing intensive efforts to improve maternal health in Ethiopia, the proportion of birth delivered at home remains high and is still the top priority among the national health threats.

Objective

The study aimed to examine effects of individual women and community-level factors of women’s decision on place of delivery in Ethiopia.

Methods

Data were obtained from the nationally representative 2011 Ethiopian Demographic and Health Survey (EDHS) which used a two-stage cluster sampling design with rural-urban and regions as strata. The EDHS collected data from a big sample size but our study focused on a sample of 7,908 women whose most recent birth was within five years preceding 2011 and 576 communities in which the women were living in. The data were analyzed using a two-level mixed-effects logistic regression to determine fixed-effects of individual- and community-level factors and random-intercept of between-cluster characteristics.

Results

In the current study, 6980 out of 7908 deliveries (88.3%) took place at home. Lower educational levels (OR=2.74, 95%CI:1.84,4.70; p<0.0001), making no or only a limited number of ANC visits (OR=3.72,95%CI:2.85, 4.83; p<0.0001), non-exposure to media (OR=1.51, 95%CI 1.13, 2.01; p=0.004), higher parity (OR=2.68, 95%CI:1.96,3.68; p<0.0001), and perceived distance problem to reach health facilities (OR=1.29, 95%CI:1.03,1.62; p=0.022) were positively associated with home delivery. About 75% of the total variance in the odds of giving birth at home was accounted for the between-community differences of characteristics (ICC=0.75, p<0.0001). With regard to community-level characteristics, rural communities (OR=4.67, 95%CI:3.06,7.11; p<0.0001), pastoralist communities (OR=4.53, 95%CI:2.81,7.28; p<0.0001), communities with higher poverty levels (OR=1.49 95%CI:1.08,2.22; p=0.048), with lower levels of ANC utilization (OR=2.01, 95%CI:1.42,2.85; p<0.0001) and problem of distance to a health facility (OR=1.29, 95%CI:1.03,1.62; p=0.004) had a positive influence on women to give birth at home.

Conclusions

Not only individual characteristics of women, but also community-level factors determine women’s decision to deliver at home.     

Modification of Astrocyte Metabolism as an Approach to the Treatment of Epilepsy: Triheptanoin and Acetyl-<Emphasis Type="SmallCaps">l</Emphasis>-Carnitine

Epilepsy is a severe neurological disorder characterized by altered electrical activity in the brain. Important pathophysiological mechanisms include disturbed metabolism and homeostasis of major excitatory and inhibitory neurotransmitters, glutamate and GABA. Current drug treatments are largely aimed at decreasing neuronal excitability and thereby preventing the occurrence of seizures. However, many patients are refractory to treatment and side effects are frequent. Temporal lobe epilepsy (TLE) is the most common type of drug-resistant epilepsy in adults. In rodents, the pilocarpine-status epilepticus model reflects the pathology and chronic spontaneous seizures of TLE and the pentylenetetrazole kindling model exhibits chronic induced limbic seizures. Accumulating evidence from studies on TLE points to alterations in astrocytes and neurons as key metabolic changes. The present review describes interventions which alleviate these disturbances in astrocyte–neuronal interactions by supporting mitochondrial metabolism. The compounds discussed are the endogenous transport molecule acetyl-l-carnitine and the triglyceride of heptanoate, triheptanoin. Both provide acetyl moieties for oxidation in the tricarboxylic acid cycle whereas heptanoate is also provides propionyl-CoA, which after carboxylation can produce succinyl-CoA, resulting in anaplerosis—the refilling of the tricarboxylic acid cycle.     

The GLT‐1 (EAAT2; slc1a2) glutamate transporter is essential for glutamate homeostasis in the neocortex of the mouse

Glutamate is the major excitatory neurotransmitter, and is inactivated by cellular uptake catalyzed mostly by the glutamate transporter subtypes GLT‐1 (EAAT2) and GLAST (EAAT1). Astrocytes express both GLT‐1 and GLAST, while axon terminals in the neocortex only express GLT‐1. To evaluate the role of GLT‐1 in glutamate homeostasis, we injected GLT‐1 knockout (KO) mice and wild‐type littermates with [1‐¹³C]glucose and [1,2‐¹³C]acetate 15 min before euthanization. Metabolite levels were analyzed in extracts from neocortex and cerebellum and ¹³C labeling in neocortex. Whereas the cerebellum in GLT‐1‐deficient mice had normal levels of glutamate, glutamine, and ¹³C labeling of metabolites, glutamate level was decreased but labeling from [1‐¹³C] glucose was unchanged in the neocortex. The contribution from pyruvate carboxylation toward labeling of these metabolites was unchanged. Labeling from [1,2‐¹³C] acetate, originating in astrocytes, was decreased in glutamate and glutamine in the neocortex indicating reduced mitochondrial metabolism in astrocytes. The decreased amount of glutamate in the cortex indicates that glutamine transport into neurons is not sufficient to replenish glutamate lost because of neurotransmission and that GLT‐1 plays a role in glutamate homeostasis in the cortex.

     

Cloning, expression and characterization of a fast self-sufficient P450: CYP102A5 from Bacillus cereus

CYP102s represent a family of natural self-sufficient fusions of cytochrome P450 and cytochrome P450 reductase found in some bacteria. One member of this family, named CYP102A1 or more traditionally P450BM-3, has been widely studied as a model of human P450 cytochromes. Remarkable detail of P450 structure and function has been revealed using this highly efficient enzyme. The recent rapid expansion of microbial genome sequences has revealed many relatives of CYP102A1, but to date only two from Bacillus subtilis have been characterized. We report here the cloning and expression of CYP102A5, a new member of this family that is very closely related to CYP102A4 from Bacillus anthracis. Characterization of the substrate specificity of CYP102A5 shows that it, like the other CYP102s, will metabolize saturated and unsaturated fatty acids as well as N-acylamino acids. CYP102A5 catalyzes very fast substrate oxidation, showing one of the highest turnover rates for any P450 monooxygenase studied so far. It does so with more specificity than other CYP102s, yielding primarily ω-1 and ω-2 hydroxylated products. Measurement of the rate of electron transfer through the reductase domain reveals that it is significantly faster in CYP102A5 than in CYP102A1, providing a likely explanation for the increased monooxygenation rate. The availability of this new, very fast fusion P450 will provide a great tool for comparative structure-function studies between CYP102A5 and the other characterized CYP102s.     

Triheptanoin partially restores levels of tricarboxylic acid cycle intermediates in the mouse pilocarpine model of epilepsy

Triheptanoin, the triglyceride of heptanoate, is anticonvulsant in various epilepsy models. It is thought to improve energy metabolism in the epileptic brain by re‐filling the tricarboxylic acid (TCA) cycle with C4‐intermediates (anaplerosis). Here, we injected mice with [1,2‐¹³C]glucose 3.5–4 weeks after pilocarpine‐induced status epilepticus (SE) fed either a control or triheptanoin diet. Amounts of metabolites and incorporations of ¹³C were determined in extracts of cerebral cortices and hippocampal formation and enzyme activity and mRNA expression were quantified. The percentage enrichment with two ¹³C atoms in malate, citrate, succinate, and GABA was reduced in hippocampal formation of control‐fed SE compared with control mice. Except for succinate, these reductions were not found in triheptanoin‐fed SE mice, indicating that triheptanoin prevented a decrease of TCA cycle capacity. Compared to those on control diet, triheptanoin‐fed SE mice showed few changes in most other metabolite levels and their ¹³C labeling. Reduced pyruvate carboxylase mRNA and enzyme activity in forebrains and decreased [2,3‐¹³C]aspartate amounts in cortex suggest a pyruvate carboxylation independent source of C‐4 TCA cycle intermediates. Most likely anaplerosis was kept unchanged by carboxylation of propionyl‐CoA derived from heptanoate. Further studies are proposed to fully understand triheptanoin's effects on neuroglial metabolism and interaction.