A New Metabolomic Signature in Type-2 Diabetes Mellitus and Its Pathophysiology

Objective

The objective of the current study was to find a metabolic signature associated with the early manifestations of type-2 diabetes mellitus.

Research Design and Method

Modern metabolic profiling technology (MxP™ Broad Profiling) was applied to find early alterations in the plasma metabolome of type-2 diabetic patients. The results were validated in an independent study. Eicosanoid and single inon monitoring analysis (MxP™ Eicosanoid and MxP™ SIM analysis) were performed in subsets of samples.

Results

A metabolic signature including significantly increased levels of glyoxylate as a potential novel marker for early detection of type-2 diabetes mellitus was identified in an initial study (Study1). The signature was significantly altered in fasted diabetic and pre-diabetic subjects and in non-fasted subjects up to three years prior to the diagnosis of type-2 diabetes; most alterations were also consistently found in an independent patient group (Study 2). In Study 2 diabetic and most control subjects suffered from heart failure. In Study 1 a subgroup of diabetic subjects, with a history of use of anti-hypertensive medication further showed a more pronounced increase of glyoxylate levels, compared to a non-diabetic control group when tested in a hyperglycemic state. In the context of a prior history of anti-hypertensive medication, alterations in hexosamine and eicosanoid levels were also found.

Conclusion

A metabolic signature including glyoxylate was associated with type-2 diabetes mellitus, independent of the fasting status and of occurrence of another major disease. The same signature was also found to be associated with pre-diabetic subjects. Glyoxylate levels further showed a specifically strong increase in a subgroup of diabetic subjects. It could represent a new marker for the detection of medical subgroups of diabetic subjects.     

The Only African Wild Tobacco,Nicotiana africana: Alkaloid Content and the Effect of Herbivory

Herbivory in some Nicotiana species is known to induce alkaloid production. This study examined herbivore-induced defenses in the nornicotine-rich African tobacco N. africana, the only Nicotiana species indigenous to Africa. We tested the predictions that: 1) N. africana will have high constitutive levels of leaf, flower and nectar alkaloids; 2) leaf herbivory by the African bollworm Helicoverpa armigera will induce increased alkaloid levels in leaves, flowers and nectar; and 3) increased alkaloid concentrations in herbivore-damaged plants will negatively affect larval growth. We grew N. africana in large pots in a greenhouse and exposed flowering plants to densities of one, three and six fourth-instar larvae of H. armigera, for four days. Leaves, flowers and nectar were analyzed for nicotine, nornicotine and anabasine. The principal leaf alkaloid was nornicotine (mean: 28 µg/g dry mass) followed by anabasine (4.9 µg/g) and nicotine (0.6 µg/g). Nornicotine was found in low quantities in the flowers, but no nicotine or anabasine were recorded. The nectar contained none of the alkaloids measured. Larval growth was reduced when leaves of flowering plants were exposed to six larvae. As predicted by the optimal defense theory, herbivory had a localized effect and caused an increase in nornicotine concentrations in both undamaged top leaves of herbivore damaged plants and herbivore damaged leaves exposed to one and three larvae. The nicotine concentration increased in damaged compared to undamaged middle leaves. The nornicotine concentration was lower in damaged leaves of plants exposed to six compared to three larvae, suggesting that N. africana rather invests in new growth as opposed to protecting older leaves under severe attack. The results indicate that the nornicotine-rich N. africana will be unattractive to herbivores and more so when damaged, but that potential pollinators will be unaffected because the nectar remains alkaloid-free even after herbivory.     

Retroviral Infection of Murine Embryonic Stem Cell Derived Embryoid Body Cells for Analysis of Hematopoietic Differentiation

Embryonic stem cells (ESCs) are an outstanding model for elucidating the molecular mechanisms of cellular differentiation. They are especially useful for investigating the development of early hematopoietic progenitor cells (HPCs). Gene expression in ESCs can be manipulated by several techniques that allow the role for individual molecules in development to be determined. One difficulty is that expression of specific genes often has different phenotypic effects dependent on their temporal expression. This problem can be circumvented by the generation of ESCs that inducibly express a gene of interest using technology such as the doxycycline-inducible transgene system. However, generation of these inducible cell lines is costly and time consuming. Described here is a method for disaggregating ESC-derived embryoid bodies (EBs) into single cell suspensions, retrovirally infecting the cell suspensions, and then reforming the EBs by hanging drop. Downstream differentiation is then evaluated by flow cytometry. Using this protocol, it was demonstrated that exogenous expression of a microRNA gene at the beginning of ESC differentiation blocks HPC generation. However, when expressed in EB derived cells after nascent mesoderm is produced, the microRNA gene enhances hematopoietic differentiation. This method is useful for investigating the role of genes after specific germ layer tissue is derived.     

Self-deception as self-signalling: a model and experimental evidence

Self-deception has long been the subject of speculation and controversy in psychology, evolutionary biology and philosophy. According to an influential ‘deflationary’ view, the concept is an over-interpretation of what is in reality an instance of motivationally biased judgement. The opposite view takes the interpersonal deception analogy seriously, and holds that some part of the self actively manipulates information so as to mislead the other part. Building on an earlier self-signalling model of Bodner and Prelec, we present a game-theoretic model of self-deception. We propose that two distinct mechanisms collaborate to produce overt expressions of belief: a mechanism responsible for action selection (including verbal statements) and an interpretive mechanism that draws inferences from actions and generates emotional responses consistent with the inferences. The model distinguishes between two modes of self-deception, depending on whether the self-deceived individual regards his own statements as fully credible. The paper concludes with a new experimental study showing that self-deceptive judgements can be reliably and repeatedly elicited with financial incentives in a categorization task, and that the degree of self-deception varies with incentives. The study also finds evidence of the two forms of self-deception. The psychological benefits of self-deception, as measured by confidence, peak at moderate levels.     

The mitochondrial unfolded protein response is activated upon hematopoietic stem cell exit from quiescence

The mitochondrial unfolded protein response (UPR^mt), a cellular protective program that ensures proteostasis in the mitochondria, has recently emerged as a regulatory mechanism for adult stem cell maintenance that is conserved across tissues. Despite the emerging genetic evidence implicating the UPR^mt in stem cell maintenance, the underlying molecular mechanism is unknown. While it has been speculated that the UPR^mt is activated upon stem cell transition from quiescence to proliferation, the direct evidence is lacking. In this study, we devised three experimental approaches that enable us to monitor quiescent and proliferating hematopoietic stem cells (HSCs) and provided the direct evidence that the UPR^mt is activated upon HSC transition from quiescence to proliferation, and more broadly, mitochondrial integrity is actively monitored at the restriction point to ensure metabolic fitness before stem cells are committed to proliferation.     

Dedifferentiation of gland cells in hydra and further development of interstitial cells arising from them

Summary Asexual, non-budding hydras were treated in the 175000 solution of E 39 solubile (Bayer). They were feeding, growing and budding for six days. The interstitial cells found in the ectoderm at the moment of treatment differentiated into cnidoblasts during that period. The cells that happened to be in the gastroderm at that time, differentiated into interstitial cells which were not able to cross the mesoglea due to the E 39 activity. In the gastroderm a great number of cnids appeared.These observations support the hypothesis that in normal hydra the interstitial cells formed by the dedifferentiation of gland cells pass into the ectoderm. There they are transformed into cnidoblasts which pass into the mesoglea. Prom the gastroderm the cnidoblasts come into the ectoderm of the tentacles through endodermal cells and the coelenteric fluid.

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Zusammenfassung Asexuelle, knospenlose Hydren wurden mit einer Lösung von Bayer E 39 (175000), solubile behandelt. Einige Tiere wurden nach 4, 6, 10 und 24 Std fixiert, die übrigen nach 24 Std in das Aquariumwasser zurückversetzt. Diese Hydren wurden in Zeitabschnitten von 24 Std innerhalb von 8 Tagen fixiert.Im Verlauf der ersten 6 Tage fressen und wachsen alle Hydren und bilden Knospen. Am 7. Tag (bei einigen am 8. Tag) beginnt die Depression: Die Nahrungsaufnahme hört auf, die Polypen kontrahieren sich allmählich und ihre Tentakel verkürzen sich. Bis zum 16. Tag sind alle Hydren eingegangen. In den ersten Stunden nach der Behandlung (bis zu 10 Std) sind imEktoderm fast gar keine Veränderungen zu bemerken, imGastroderm kommt es jedoch zu Veränderungen in der Größe, Form und im Bau der zymogenen Zellen. Nach dem 1. Tag verschwinden die interstitiellen Zellen allmählich, aber die Cnidoblasten und die Cniden verbleiben vollzählig bis zum 7. Tag, dann aber nimmt die Zahl der Cnidoblasten ab. In geringerer Zahl bleiben jedoch die Cniden bis zum Lebensende erhalten. Die zymogenen Zellen dedifferenzieren sich zu interstitiellen Zellen, einige unter ihnen verwandeln sich in kleine kugelförmige, ausgesprochen basophile Zellen, welche sich an der Mesogloea ansammeln.Am Anfang, wenn E 39 noch nicht zu voller Wirkung gekommen ist, durchwandern interstitielle Zellen die Mesogloea und gliedern sich in das Ektoderm ein. Dieser Zellübergang nimmt allmählich ab, hört aber niemals vollkommen auf. Während dieser Zeit häufen sich immer mehr reife Cniden im Gastroderm an. Die Autoren sind der Meinung, daß es sich hierbei um Cniden handelt, die sich einerseits aus jenen Cnidoblasten entwickelt haben, die am Anfang der Behandlung aus dem Ektoderm in das Gastroderm eingewandert sind, andererseits von interstitiellen Zellen abstammen, die durch Dedifferenzierung aus zymogenen Zellen entstanden und im Gastroderm übriggeblieben sind. Sie entwickelten sich dort, weil sie infolge der Wirkung von E 39 weder durch die Mesogloea hindurchtreten, noch in die Tentakel einwandern konnten. Diese Prozesse werden in der Arbeit ausführlich diskutiert.Auf Grund dieser Beobachtungen nehmen die Autoren an, daß auch in der normalen Hydra die aus zymogenen Zellen entstandenen interstitiellen Zellen in das Ektoderm einwandern, wo sie sich teilen und zu Cnidoblasten ausdifferenzieren.Ein Teil dieser Cnidoblasten wandert durch die Mesogloea in das Gastroderm ein, aber aus dem Gastroderm mittels entodermaler Zellen und gastraler Flüssigkeit wieder aus und gelangt schließlich in das Ektoderm der Tentakel.

     

Purification and properties of esterases characteristic of adult rat brain

1. A method for the partial purification of an esterase fraction, present in the brain of the adult but not the newborn rat, is described. A 54-fold purification was achieved in three steps. 2. When subjected to starch-gel electrophoresis, the purified fraction resolved into three bands of esterase activity. Two of these bands migrate close together and faster than other esterases in the brain. These two esterases are inhibited by p-hydroxymercuribenzoate but not by di-isopropyl phosphorofluoridate. The third band is di-isopropyl phosphorofluoridate-sensitive and migrates just behind the two leading esterases. 3. After treatment with di-isopropyl phosphorofluoridate, to obviate the effects of the di-isopropyl phosphorofluoridate-sensitive esterase, the enzyme preparation hydrolyses alpha-naphthyl acetate, alpha-naphthyl propionate and alpha-naphthyl butyrate, but not cholesteryl acetate. The V(max.) for the naphthyl esters decreased with increase in chain length of the acyl group. The acetate ester is hydrolysed 34 times as fast as the butyrate and about seven times as fast as the propionate derivative. The K(m) values for these three esters, measured at pH7.2 and 37 degrees , are 2.8x10(-4)m, 3.1x10(-4)m and 7.3x10(-5)m for the acetate, propionate and butyrate derivatives respectively. 4. The Hofstee (1952) plots for the kinetic data show a single line, indicating that the two most-rapidly migrating esterases, although electrophoretically separable, are not kinetically distinguishable in the substrate ranges examined.     

Das Gastroderm im Prozeß der Regeneration der Hydra

Zusammenfassung Es wurden Amputationen an Hydren in der hypostomalen Region durchgeführt. Das Material wurde in verschiedenen Zeitabschnitten fixiert (von 5 min bis 19 Std). Die Heilung der Wunde findet unter Mitwirkung aller entodermalen Zellen statt. Der Prozeß der Regeneration geht von zymogenen Zellen aus, welche sich zu Neoblasten entdifferenzieren. Diese wandeln sich durch Differentiation in ektodermale Zellelemente um. Das alte Ektoderm hat an der Bildung des jungen Ektoderms im Gebiete der Wunde keinen Anteil.Der Wandel des Entoderms im Verlaufe der Heilung der Wunde und der Regeneration wurde mit Hilfe histochemischer Methode zur Darstellung der sauren Phosphatase verfolgt. Es wurde die Annahme geäußert, daß die zymogenen Zellen auch bei der normalen Hydra das Ektoderm mit neuen Zellen versorgen.

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The gastroderm in the process of the regeneration of hydra

Summary The amputations of the hydra in the hypostomal region have been performed. The material has been fixed in various time intervals after the amputation (from 5 min to 19 hours).The healing of the wound is done with the participation of all endodermal cells, the regeneration process with the help of zymogenic cells which dedifferenciate into neoblasts, and the neoblasts develop into ectodermal cell elements by differentiation. The old ectoderm does not take part in forming the young ectoderm in the wound area.The participation of endoderm in healing the wound and in the regeneration has been stated by the method for the acid phosphatase. It is supposed that the zymogenic cells also in normal hydra supply the ectoderm with new cells.

     

The Stabilization of Amorphous Zopiclone in an Amorphous Solid Dispersion

Zopiclone is a poorly soluble psychotherapeutic agent. The aim of this study was to prepare and characterize an amorphous form of zopiclone as well as the characterization and performance of a stable amorphous solid dispersion. The amorphous form was prepared by the well-known method of quench-cooling of the melt. The solid dispersion was prepared by a solvent evaporation method of zopiclone, polyvinylpyrrolidone-25 (PVP-25), and methanol, followed by freeze-drying. The physico-chemical properties and stability of amorphous zopiclone and the solid dispersion was studied using differential scanning calorimetry (DSC), infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), hot-stage microscopy (HSM), X-ray diffractometry (XRD), solubility, and dissolution studies. The zopiclone amorphous solid-state form was determined to be a fragile glass; it was concluded that the stability of the amorphous form is influenced by both temperature and water. Exposure of amorphous zopiclone to moisture results in rapid transformation of the amorphous form to the crystalline dihydrated form. In comparison, the amorphous solid dispersion proved to be more stable with increased aqueous solubility.KEY WORDS: amorphous, fragile, solid dispersion, stability, zopiclone     

Comparing the effect of modeled climatic variables on the distribution of African horse sickness in South Africa and Namibia

Africa horse sickness (AHS) is a lethal disease of horses with a seasonal occurrence that is influenced by environmental conditions that favor the development of Culicoides midges (Diptera: Ceratopogonidae). This study compared and evaluated the relationship of various modeled climatic variables with the distribution and abundance of AHS in South Africa and Namibia. A comprehensive literature review of the historical AHS reported data collected from the Windhoek archives as well as annual reports from the Directorate of Veterinary services in Namibia were conducted. South African AHS reported data were collected from the South African Department of Agriculture, Forestry, and Fisheries. Daily climatic data were extracted for the time period 1993–2011 from the ERA‐interim re‐analysis dataset. The principal component analysis of the complete dataset indicated a significant statistical difference between Namibia and South Africa for the various climate variables and the outbreaks of AHS. The most influential parameters in the distribution of AHS included humidity, precipitation, evaporation, and minimum temperature. In South Africa, temperature had the most significant effect on the outbreaks of AHS, whereas in Namibia, humidity and precipitation were the main drivers. The maximum AHS cases in South Africa occurred at temperatures of 20–22° C and relative humidity between 50–70%. Furthermore, anthropogenic effects must be taken into account when trying to understand the distribution of AHS.