Reactions of PtII diamine anticancer complexes with trypanothione and octreotide

The products formed in reactions of the square-planar platinum(II) anticancer complexes, [Pt(en)Cl₂] and [Pt(R,R-dach)Cl₂] where en = ethylenediamine and dach = diaminocyclohexane, with trypanothione, a glutathione analogue found in some parasites, and octreotide, a synthetic analogue of the hormone somatostatin, have been investigated. Mononuclear and binuclear platinum adducts were formed in reactions of the cyclic disulfides in their oxidised and reduced forms, and were analysed by UV–visible spectroscopy and liquid chromatography–mass spectrometry (LC–MS). NMR and molecular modelling studies were carried out on the mononuclear adducts.     

Risk for schizophrenia and schizophrenia-like psychosis among patients with epilepsy: population based cohort study

Objectives To investigate whether age at onset of epilepsy, type of epilepsy, family history of psychosis, or family history of epilepsy affect the risk of schizophrenia or schizophrenia-like psychosis among patients with epilepsy.Design Comparison of population based data.Setting Danish longitudinal registers.Subjects The cohort comprised 2.27 million people.Main outcome measures Epilepsy, psychosis, personal birth data.Results We found an increased risk of schizophrenia (relative risk 2.48, 95% confidence interval 2.20 to 2.80) and schizophrenia-like psychosis (2.93, 2.69 to 3.20) in people with a history of epilepsy. The effect of epilepsy was the same in men and in women and increased with age. Family history of psychosis and a family history of epilepsy were significant risk factors for schizophrenia and schizophrenia-like psychosis, and the effect of epilepsy, both in cases and families, was greater among people with no family history of psychosis. In addition, the increased risk for schizophrenia or schizophrenia-like psychosis did not differ by type of epilepsy but increased with increasing number of admissions to hospital and, particularly, was significantly greater for people first admitted for epilepsy at later ages.Conclusions There is a strong association between epilepsy and schizophrenia or schizophrenia-like psychosis. The two conditions may share common genetic or environmental causes.     

Long-term survival and germination of Bacillus thuringiensis var. kurstaki in a field trial

Long-term survival, dispersal, and germination of Bacillus thuringiensis var. kurstaki DMU67R has been investigated in a field trial. An experimental cabbage plot was sprayed with DMU67R in 1993 and allowed to lie fallow since. The investigations reported here were carried out from 1997 to 2000 in this plot. High persistence of DMU67R for 7 years in the bulk soil of the plot has been demonstrated. The numbers have not significantly reduced since 1994, stabilizing around 6.6 x 10(2) cfu/g from 1996 to 2000. Horizontal dispersal of DMU67R in the 1994-1999 period was limited. Vertical dispersal occurred from 1994 to 1999, as 77% of the population of DMU67R occurred in the 0-2 cm layer in 1994, while only 22% of the population was found there in 1999. Most of the population in 1999 was present homogeneously in the upper 6 cm of the soil profile. Germination, as evidenced by the ratio of DMU67R cfu before and after heat treatment, was not observed in the bulk soil. However, in the rhizospheres of dandelion (Taraxacum officinalis) and quackgrass (Agropyron repens), 40 and 50% of DMU67R was present as vegetative germinated cells, respectively. No germination occurred in the rhizosphere of red fescue (Festuca rubra). The material from the gut of the earthworm species Lumbricus rubellus, Lumbricus terrestris, and Apporrectodea caliginosa and from a tipulid larvae from the plot also contained vegetative cells of DMU67R. Further investigations of A. caliginosa showed that germination seemed to be restricted to the gut and that sporulation occurred after defecation. The germination of DMU67R in rhizospheres and in the gut of nontarget invertebrates suggests that survival in the soil of B. thuringiensis is a dynamic process involving germination, cell divisions, and sporulation in specific microhabitats.     

Estuarine morphometry governs optically active substances, K d(PAR) and beam attenuation: assessments from a tropical ria and a temperate coastal plain estuary

Data on optical properties such as diffuse attenuation coefficient K _d(PAR), beam attenuation coefficient (c _p) and the optically active constituents (OACs) CDOM, Chl-a and suspended particulate matter were obtained in a Danish temperate coastal plain estuary (56°N) and a Vietnamese tropical ria (12°N) at high discharges. The major difference was the spatial distribution of the optical properties against distance, best described by significant power functions in the ria, compared to significant linear functions in the coastal plain. It was hypothesized that estuarine morphometry could explain this spatial distribution. Partition and multiple regression analyses showed that Chl-a governed K _d(PAR) and beam attenuation coefficient in both estuaries. Significant, high correlations were obtained by multiple regression analyses in the estimation of K _d(PAR) and beam attenuation coefficients in the two estuaries using OACs as input parameters. It is concluded that there are no large differences in OAC concentrations between the two estuaries. The spatial distributions of OACs and optical properties were significantly different and governed by the estuary morphometry, i.e. a power distribution in the tropical ria and a linear function in the temperate coastal plain estuary, and applicable to similar estuary types.     

Pathogenomic sequence analysis of Bacillus cereus and Bacillus thuringiensis isolates closely related to Bacillus anthracis

Bacillus anthracis, Bacillus cereus, and Bacillus thuringiensis are closely related gram-positive, spore-forming bacteria of the B. cereus sensu lato group. While independently derived strains of B. anthracis reveal conspicuous sequence homogeneity, environmental isolates of B. cereus and B. thuringiensis exhibit extensive genetic diversity. Here we report the sequencing and comparative analysis of the genomes of two members of the B. cereus group, B. thuringiensis 97-27 subsp. konkukian serotype H34, isolated from a necrotic human wound, and B. cereus E33L, which was isolated from a swab of a zebra carcass in Namibia. These two strains, when analyzed by amplified fragment length polymorphism within a collection of over 300 of B. cereus, B. thuringiensis, and B. anthracis isolates, appear closely related to B. anthracis. The B. cereus E33L isolate appears to be the nearest relative to B. anthracis identified thus far. Whole-genome sequencing of B. thuringiensis 97-27and B. cereus E33L was undertaken to identify shared and unique genes among these isolates in comparison to the genomes of pathogenic strains B. anthracis Ames and B. cereus G9241 and nonpathogenic strains B. cereus ATCC 10987 and B. cereus ATCC 14579. Comparison of these genomes revealed differences in terms of virulence, metabolic competence, structural components, and regulatory mechanisms.     

Synthetic analogs of anoplin show improved antimicrobial activities

We present the antimicrobial and hemolytic activities of the decapeptide anoplin and 19 analogs thereof tested against methicillin‐resistant Staphylococcus aureus ATCC 33591 (MRSA), Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853), vancomycin‐resistant Enterococcus faecium (ATCC 700221) (VRE), and Candida albicans (ATCC 200955). The anoplin analogs contain substitutions in amino acid positions 2, 3, 5, 6, 8, 9, and 10. We use these peptides to study the effect of altering the charge and hydrophobicity of anoplin on activity against red blood cells and microorganisms. We find that increasing the charge and/or hydrophobicity improves antimicrobial activity and increases hemolytic activity. For each strain tested, we identify at least six anoplin analogs with an improved therapeutic index compared with anoplin, the only exception being Enterococcus faecium, against which only few compounds are more specific than anoplin. Both 2Nal⁶ and Cha⁶ show improved therapeutic index against all strains tested. Copyright © 2013 European Peptide Society and John Wiley & Sons, Ltd.     

The use of PET/CT scanning technique for 3D visualization and quantification of real-time soil/plant interactions

Aims

Conventional methodology using destructive sampling, which is laborious and has poor spatial and temporal resolution, has limited our understanding of soil-plant interactions. New non-invasive tomographic techniques have the potential to significantly improve our knowledge. In this study we demonstrated the simultaneous use of PET (positron emission tomography) and CT (X-ray computed tomography) to (a) non-destructively image a whole plant growing in sand, and (b) to link the observed morphology with recently assimilated C. The PET scanner was used to detect and visualize the location of the short-lived radioisotope ¹¹C (with a half-life of 20.4?min) taken up by the plant through ¹¹C-labelled CO₂. This provided information on carbon translocation and the metabolism of photo-assimilates in the plant as well as root structure. The CT scanners yielded data on soil and root structure.

Methods

A medical PET/CT scanner was used to scan a fodder radish plant growing in a pot with test soil composed of homogenous sand. We constructed an air-plant-soil controller system (APS) to control the environmental conditions, such as CO₂, temperature and light during the experiment. The plant was allowed to assimilate ¹¹CO₂ for 90?min before PET scanning was initiated. We carried out PET scanning for 60?min. Subsequently, the aerial parts of the plant was cut off and the pot was rescanned using a micro-CT scanner to obtain more detailed information on structure of the root system and the growth medium structure.

Results

The acquired PET and CT images gave images clearly visualizing the architecture and morphology of root and soil. Using a CT scanner, we were able to detect the main taproot located at 0 to 30?mm depth. With the PET scanner, we were able to measure a signal down to 82?mm below the surface of the sand. We found the highest concentration of ¹¹C at the position of the main root. The PET images, at different time intervals, showed the translocation and metabolisation of photo-assimilates from top to root. Using the micro-CT scanner (voxel size of 90?μm), we were able to detect roots down to 100?mm depth. These findings correlated the PET signals measured down to 82?mm depth.

Conclusions

We conclude that the simultaneous use of PET and CT technologies was successfully applied for soil-plant studies. The combined PET/CT technology has potential to provide new fundamental insight into soil-plant interactions and especially into the effect of abiotic stresses in spite of the limitation due to spatial resolution.     

Autoradiographische Untersuchungen des Transportes einiger Nahrungsbestandteile im Darmtrakt zweier Kleinzikaden: Euscelidius variegatus Kbm. (Jassidae) und Triecphora vulnerata Germ. (Cercopidae)

Zusammenfassung Durch Verfütterung von radioaktiv markierten Nahrungsbestandteilen, geboten in synthetischer Nährlösung, wird die Richtigkeit der Hypothese von Berlese (1909) und Licent (1913) über die Funktion der Filterkammer für Euscelidius variegatus (Jassidae) und Triecphora vulnerata (Cercopidae) bewiesen. Während Wasser und Saccharose bzw. deren Spaltprodukte zum großen Teil die Filterepithelien passieren, in den Enddarm gelangen und als Honigtau vorzeitig ausgeschieden werden, verbleiben Aminosäuren und Protein im Verdauungstrakt. Eine Art Druckfiltration in der Filterkammer wird vermutet, da sich keine Hinweise für einen aktiven Transport durch die Filterepithelien erkennen lassen.

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Autoradiographic experiments on the transport of some nutritional elements in the digestive tract of two leafhoppers: Euscelidius variegatus Kbm. (Jassidae) and Triecphora vulnerata Germ. (Cercopidae)

Summary By feeding of radioactive nutritional elements in a synthetic diet the hypothesis of Berlese (1909) and Licent (1913) is proved for Euscelidius variegatus (Jassidae) and Triecphora vulnerata (Cercopidae). Most of the water and the sucrose or its monosaccharides pass the filter epithelia, reach the hind gut immediately and are defecated precociously as honey dew. Amino acids and protein on the other hand remain in the digestive tract. Some sort of filtration by pressure in the filter chamber is to be supposed as there are no hints on an active transport through the filter epithelia.

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Mit Unterstützung der Deutschen Forschungsgemeinschaft.     

Protein quality control in the endoplasmic reticulum

Protein folding and quality control in the endoplasmic reticulum (ER) are synchronized mechanisms ensuring that only properly folded proteins are integrated in the plasma membrane or secreted from the cell. These mechanisms act in close collaboration with the molecular machinery involved in retrograde-translocation and degradation of non-native proteins and with the ER-stress activated signalling systems. The common goal of these mechanisms is to prevent expression and secretion of misfolded proteins. Protein misfolding can be detrimental to the cell and contributes to the disease mechanism in several inherited disorders, e.g. cystic fibrosis, familial hypercholesterolemia and diabetes insipidus. This review outlines the molecular mechanisms in protein quality control occurring in the ER, signalling caused by ER stress, and finally ER associated protein degradation.     

Diagnostic properties of three conventional selective plating media for selection of <Emphasis Type="Italic">Bacillus cereus</Emphasis>, <Emphasis Type="Italic">B. thuringiensis</Emphasis> and <Emphasis Type="Italic">B. weihenstephanensis</Emphasis>

The aim of this study was to assess the diagnostic properties of the two selective plating media and a chromogenic medium for identification of Bacillus cereus. The 324 isolates were B. cereus (37%), Bacillus weihenstephanensis (45%) or Bacillus thuringiensis (18%), as identified by a new combination of techniques. All isolates were growing on mannitol–egg yolk–polymyxin agar (MYP), and they did not form acid from mannitol. However, a significant lower number of B. thuringiensis isolates did not show lecithinase activity. All isolates were also growing on polymyxin–egg yolk–mannitol–bromothymol blue agar (PEMBA); however, 11% isolates indicated that they did produce acid from mannitol, and 15% isolates did not show any lecithinase activity. Five of the isolates did not grow at all on the chromogenic agar, and 14 of the growing isolates were β-glucosidase negative. It is concluded that the two recommended selective plating media MYP and PEMBA for detection of B. cereus group bacteria both have their limitations for identification of some B. cereus, B. weihenstephanensis or B. thuringiensis. However, MYP is preferable compared to PEMBA. The chromogenic medium has its own advantages and limitations, and some of the limitations seem to be solved by incubation at 30°C instead of the recommended 37°C.