Demonstration of “polyphosphate” and its possible role in RNA synthesis during early development of Rana japonica embryos

It has been described that the RNA preparation obtained from the Rana japonica embryos by phenol-SDS technique contained the substance incorporating radioactive orthophosphate very rapidly, while DNA and ribosomal RNA did not take up the label very much. From a methylated albumin column it was eluted between DNA and ribosomal RNA as a single peak, and insensitive against RNase and alkali. Moreover, it was non-dialyzable and precipitable as barium salt by Wiame's reagent. These observations made it likely that this substance might be polyphosphate. Possible function of “polyphosphate” was discussed in connection with the RNA synthesis throughout early development.     

Racial boundaries,stigma, and the re-emergence of “always being foreigners”: Iranians and the refugee crisis in Germany

The 2015 refugee crisis is at the center of public and political discourse across Europe, especially among nations that have accepted refugees. Utilizing ethnographic fieldwork and 48 in-depth interviews conducted in 2011 and 2016 with Iranians in Hamburg, Germany, this paper considers how the refugee crisis impacts the racial boundaries between Germans and immigrant communities. It details how the crisis has made ethnic nationalism, Islamophobia, anti-foreigner prejudice and racism more pronounced and salient throughout Germany. The interviews demonstrate that this climate affects Iranians in several ways: they cite feeling more threat and stigma, as well as experiences of marginality, perpetual foreignness, and discrimination. This research contributes to sociological scholarship on migration and race by examining how critical international events influence and shape processes of racialization, identity and belonging, and social boundaries and hierarchies.     

The “polarizing inducer” in hydra: A reexamination of its properties and its origin

Summary In order to prove the gradient hypothesis an attempt was made to isolate and accumulate the polarizing inducer present in homogenates of hydra and assumed to be a neurosecretory product. By means of gel chromatography two fractions were obtained which brought about the development of supernumary apical structures (tentacles and hypostomes) thus exhibiting the symptoms attributed to this polarizing agent: a low molecular fraction with only modest effectiveness and a main fraction with strong animalizing ability. Increasing the concentration affected only the quantity but not the qualitative properties of the structures produced, a result inconsistent with the postulate of the gradient hypothesis. By analysing the chemical and biological nature of the main agent and by applying pure isolated toxins compelling evidence is given that the inducer in question is nothing but a component of the nematocyst toxins. This component, being heat-stable and trypsin-sensitive, elicites its animalizing effect in unspecific means by disturbing the normal pattern of morphallactic events. A side effect with interest in respect of graded tissue properties could be recorded: by the influence of the relevant toxin, growing together of regenerating animals occurs whereby predominantly apical primordia fuse with apical primordia, thus forming stable parabioses. This observation may indicate the significance of surface bound, contact establishing components in polar differentiation.

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Zusammenfassung Zur Prüfung der entwicklungsphysiologischen Gradiententheorie wird der Versuch unternommen, den polarisierenden Induktor zu isolieren und anzureichern, der in Homogenaten von Hydra zugegen ist und als neurosekretorisches Produkt angesehen wird. Die Gelchromatographie wäßriger Extrakte liefert 2 Fraktionen, welche die Entwicklung überzähliger apikaler Strukturen (Tentakel und Mundkegel) hervorrufen: eine niedermolekulare Fraktion mit nur mäßiger Wirksamkeit und eine Hauptfraktion im mittelmolekularen Bereich mit starker animalisierender Kapazität. Entgegen dem Postulat der Gradiententheorie besteht keine Korrelation zwischen der applizierten Konzentration und der Qualität ausgelöster Formbildungen. Nur die Anzahl überzähliger Strukturen ist dosisabhängig. Die Analyse der biologischen und chemischen Eigenschaften der Hauptfraktion bringt den Hinweis, daß das polarisierende Agens eine Hitze-stabile, Trypsin-sensitive Komponenteder Nesselgifte ist, die ihre animalisierende Wirkung in unspezifischer Weise zeitigt. Die Applikation isolierter, reiner Nesselgifte erhärtet diese Vermutung zum klaren Beweis. Ein Nebeneffekt des relevanten Gifts legt graduierte Gewebseigenschaften offen: Unter seinem Einfluß verwachsen die Testpolypen, sowie sie in Kontakt zueinander kommen. Hierbei verbinden sich vorzugsweise apikale Primordien mit apikalen Primordien, um stabile Parabiosen zu bilden. Diese Beobachtung mag die Bedeutung Kontakt-vermittelnder Oberflächenstrukturen für das polare Differenzierungsgeschehen anzeigen.

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Supported by Deutsche Forschungsgemeinschaft.     

Studies of fluorescent components of the “heparin” drug and its complexing with phenylalanine, tyrosine, and tryptophan

Impurities of free aromatic amino acids (Phe and Tyr) and the elastin protein were found in the heparin commercial drug (Hep) by spectral luminescent and spectrophotometric methods. The fluorescence quenching of the Trp, Tyr, and Phe amino acids by the Hep drug was studied, and the Stern-Folmer constants (K) that reflected stability of the Hep complexes with amino acids were determined. The stability of AA-Hep complexes increased in the following sequence: Trp < Tyr < Phe (K = 19 ± 2 < 39 ± 3 < 710 ± 70 M^?1, respectively). These values probably determined the dominant contribution of the phenylalanine impurity in the heparin drug. The contamination of animal elastin whose structure differed from that of the human elastin is thought to be a reason for allergic reactions and even anaphylactic shock during medical treatment with this drug.     

Inflorescence scent,color, and nectar properties of “butterfly bush” (Buddleja davidii) in its native range

In this study, flower color, nectar properties, and inflorescence scent composition of eight natural and one introduced Buddleja davidii populations were investigated. Flower color of B. davidii was determined using the Royal Horticultural Society Color Chart and ranged from purple to white. Volume of nectar produced by a single flower ranged from 0.36 μl to 0.64 μl and total sugar concentration produced by inflorescence ranged from 17.0% to 33.5% in all populations. Floral nectar volume and sugar concentration were not significantly different between two flower color morphs in the B. davidii populations. Floral scents of B. davidii were collected using dynamic headspace adsorption and identified with coupled gas chromatography and mass spectrometry. In total, 33 compounds were identified from the inflorescences of B. davidii. The identified scents were divided into five chemical classes based on their biosynthetic origin: irregular terpenes, monoterpenoids, sesquiterpenoids, fatty acid derivatives, and benzenoids. The scent profiles in all populations were dominated by few components, such as: 4-oxoisophorone, E,E-α-farnesene, and 1-octen-3-ol. Given that inflorescence scents from natural and introduced individuals coming from the same population have discrepant chemical composition, we infer that phenotype plasticity may mediate floral scent composition. Based on the comparison of present and other data available on floral scent in B. davidii, we conclude that inflorescence scent may serve as a specific signal helping to attract pollinating butterflies to locate flowers as nectar sources, and may have evolved in conjunction with the sensory capabilities of butterflies and moths as a specific group of pollinators.     

Engineering, expression, and purification of “soluble” human cytochrome P45017α and its functional characterization

To engineer a "soluble" form of membrane-bound cytochrome P45017alpha (CYP17)--a key enzyme in steroid hormone biosynthesis--in the present work we have built a computer model of the tertiary structure of the hemeprotein, identified the surface hydrophobic amino acid residues, substituted these residues for more hydrophilic ones, and expressed and purified hydrophilized forms of CYP17. We have constructed and purified the following mutant forms of human CYP17: CYP17dH (CYP17 with deleted hydrophobic N-terminal sequence (Delta(23))) and CYP17mod (CYP17dH with substituted cluster of hydrophobic amino acid residues in the region of the FG-loop). Removal of the N-terminal sequence responsible for interaction with the membrane does not dramatically change the association of the protein with the membrane. However, CYP17mod containing hydrophilic FG-loop is mostly localized in the cytosolic fraction. Thus, in the present work we for the first time engineered a "soluble" form of the usually membrane-bound human CYP17 that is not bound to membrane. The expression degree of CYP17mod is approximately 900 nmol/liter of culture. The hemeprotein can be purified to apparent homogeneity without using detergents at any purification step. It is shown that replacement of hydrophobic amino acid residues in the FG-loop region does not change the metabolic profile during hydroxylation of steroids that is characteristic for wild type CYP17. Besides, the modification of the hemeprotein does not affect the affinity of CYP17 to steroid substrates. The engineered "soluble" form of human CYP17 is used as a subject for crystallization of the hemeprotein.     

The following article for this Special Issue was previously published and can be found in its respective issue online: “Detection of early Alzheimer’s disease-like molecular alterations in a mouse model expressing human ApoE4”

Detection of early Alzheimer’s disease-like molecular alterations in a mouse model expressing human ApoE4 (Published in JNC 166.3 issue) https://onlinelibrary.wiley.com/doi/10.1111/jnc.15904     

Efficacy and safety of rituximab treatment in early primary Sj?gren's syndrome: a prospective,multi-center,follow-up study

Introduction

Primary Sjögren’s syndrome (pSS) is an autoimmune disorder affecting exocrine glands; however, a subgroup of pSS patients experience systemic extra-glandular involvement leading to a worsening of disease prognosis. Current therapeutic options are mainly empiric and often translated by other autoimmune diseases. In the last few years growing evidence suggests that B-cell depletion by rituximab (RTX) is effective also in pSS. Patients with early active disease appear to be those who could benefit the most from RTX. The aim of this study was to investigate the efficacy and safety of RTX in comparison to disease modifying anti-rheumatic drugs (DMARDs) in early active pSS patients.

Methods

Forty-one patients with early pSS and active disease (EULAR Sjogren’s syndrome disease activity index, ESSDAI ≥ 6) were enrolled in the study. Patients were treated with either RTX or DMARDs in two different Rheumatology centers and followed up for 120 weeks. Clinical assessment was performed by ESSDAI every 12 weeks up to week 120 and by self-reported global disease activity pain, sicca symptoms and fatigue on visual analogic scales, unstimulated saliva flow and Schirmer’s I test at week 12, 24, 48, 72, 96, and 120. Laboratory assessment was performed every 12 weeks to week 120. Two labial minor salivary gland (MSG) biopsies were obtained from all patients at the time of inclusion in the study and at week 120.

Results

Our study demonstrated that RTX treatment results in a faster and more pronounced decrease of ESSDAI and other clinical parameters compared to DMARDs treatment. No adverse events were reported in the two groups. We also observed that RTX is able to reduce glandular infiltrate, interfere with B/T compartmentalization and consequently with the formation of ectopic lymphoid structures and germinal center-like structures in pSS-MSGs.

Conclusions

To our knowledge, this is the first study performed in a large cohort of early active pSS patients for a period of 120 weeks. We showed that RTX is a safe and effective agent to be employed in pSS patients with systemic, extra-glandular involvement. Furthermore, our data on pSS-MSGs provide additional biological basis to employ RTX in this disease.     

The following article for this Special Issue was previously published and can be found in its respective issue online: “How can I measure brain acetylcholine levels in vivo? Advantages and caveats of commonly used approaches”

How can I measure brain acetylcholine levels in vivo? Advantages and caveats of commonly used approaches (Published in JNC 167.1 issue) https://onlinelibrary.wiley.com/doi/10.1111/jnc.15943     

Vocalization in chicks,and the concept of “stimulus contrast”

• 1.1. The calls of the chick form a single system of responses, in which increasing intensity is shown by increasing length, pitch and number of trilling cycles.
• 2.2. The twitter and related calls are elicited by any stimulus which contrasts with background stimulation. Such stimuli are said here to have “intrinsic contrast”.
• 3.3. Naive chicks twitter when pecking at any type of small particle. In experienced chicks, twitters are given during pecks at food when hungry. Chicks trained to peck a lever for a food reward gave most of their twitters at the time when they perceived cues announcing the arrival of food. After long deprivation of food the number of calls given remained high throughout a session of fifty rewards, but after brief deprivation the number of calls were high for only the first few rewards and then became low.Twitters are also given to cues which announce the automatic presentation of food or, in thirsty birds, water.An explanation in terms of conditioning of the twitter is discussed and shown to be improbable. It is likely that the cues announcing food are given contrast because of the chick's set to perceive them, and that this set is affected by hunger. Contrast given to stimuli in this way is here termed “signal contrast”.
• 4.4. It is argued that all the calls of the chick form a single system of responses evoked by stimulus contrast of differing persistence and intensity. Persistent and relatively intense contrast, such as results from cold or absence of the imprinting object, is needed to evoke calls towards the peep end of the twitter-peep series, whilst very intense contrast such as that provided by a painful electric shock is needed to elicit a shriek.
• 5.5. The association between twitters and approach to the stimulus source, and between peeps and avoidance, can be explained by assuming that approach may be elicited by moderate stimulus contrast, and avoidance by intense contrast.
• 6.6. Other groups of responses, which may be best regarded as elicited by stimulus contrast, include alert responses, protective responses and certain autonomic responses associated with conflict. The latter two groups have probably both given rise to display components.