Formation of enlarged mitochondria in a liver cell line in response to a synthetic glucocorticoid

For a number of years it has been recognized that glucocorticoids cause alterations in liver cell morphology (6, 9). Several investigators have shown that in liver in vivo mitochondria can be enlarged to many times their normal volume by treatment with cortisone (13, 15). There is a concomitant decrease in mitochondrial number, and the results of Kimberg and Loeb suggest that this is due to mitochondrial fusion (7). However, the exact mechanism whereby mitochondrial volume is altered and whether in fact cortisone is the direct causal agent are not known due to the complexity of studying these questions in a whole animal system. We have found that dexamethasone sodium phosphate (dex), a synthetic glucocorticoid, causes the formation of enlarged mitochondria in a liver cell line RLC-GAI, which grows in defined medium. In this paper we present our observations on the amount of enlargement that occurs after 5 days of treatment. The formation of enlarged mitochondria is reversible upon removal of the hormone from the medium, and we have attempted to determine whether "mitochondrial" or "nonmitochondrial" inhibitors are more effective in blocking the return of mitochondria to their normal size when the hormone is removed.     

Description of Euroleptochromus gen.n. (Coleoptera,Staphylinidae, Scydmaeninae) from Baltic amber,with discussion of biogeography and mouthpart evolution within Clidicini

A new extinct species of the ant‐like stone beetle supertribe Mastigitae, Euroleptochromus sabathi gen. & sp.n. is described from Eocene Baltic amber. A phylogenetic analysis of Clidicini, with representatives of Leptomastacini and Mastigini as out‐group taxa, provided strong support for a sister‐group relationship between the Neotropical Leptochromus and the new genus. The monophyly of Clidicini is questioned because of an alternative placement of Nearctic Papusus as a sister taxon to Leptomastacini + [Clidicus + (Palaeoleptochromus + (Euroleptochromus + Leptochromus))]. A dispersal‐vicariance analysis provided three alternative scenarios for the evolution of Mastigitae; with Laurasia as the ancestral area of the supertribe, major branching events occurring within either Eurasia or Laurentia and two trans‐Beringia dispersals in Late Cretaceous and Eocene. Euroleptochromus, Palaeoleptochromus and Leptochromus share highly derived structures on postgenae and maxillary palps, probably as part of a specialised feeding or prey capture mechanism. The formation of these modifications in Clidicini is demonstrated to involve a process (traced back to the Campanian, 79 Ma) of elongation and narrowing of maxillary palps and forming a cuticular setal projection from a broadened insertion site of sensory setae.     

Biologically relevant effects of mRNA amplification on gene expression profiles

Background  

Gene expression microarray technology permits the analysis of global gene expression profiles. The amount of sample needed limits the use of small excision biopsies and/or needle biopsies from human or animal tissues. Linear amplification techniques have been developed to increase the amount of sample derived cDNA. These amplified samples can be hybridised on microarrays. However, little information is available whether microarrays based on amplified and unamplified material yield comparable results.     

X-linked adrenoleukodystrophy (X-ALD): clinical presentation and guidelines for diagnosis, follow-up and management

Background

Pompe disease (Glycogen storage disease type II, GSD II, acid alpha-glucosidase deficiency, acid maltase deficiency, OMIM # 232300) is an autosomal-recessive lysosomal storage disorder due to a deficiency of acid alpha-glucosidase (GAA, acid maltase, EC 3.2.1.20, Swiss-Prot P10253). Clinical manifestations are dominated by progressive weakness of skeletal muscle throughout the clinical spectrum. In addition, the classic infantile form is characterised by hypertrophic cardiomyopathy.

Methods

In a cross-sectional single-centre study we clinically assessed 3 patients with classic infantile Pompe disease and 39 patients with non-classic presentations, measured their acid alpha-glucosidase activities and analysed their GAA genes.

Results

Classic infantile patients had nearly absent residual enzyme activities and a typical clinical course with hypertrophic cardiomyopathy until the beginning of therapy. The disease manifestations in non-classic patients were heterogeneous. There was a broad variability in the decline of locomotive and respiratory function. The age of onset ranged from birth to late adulthood and correlated with enzyme activities. Molecular analysis revealed as many as 33 different mutations, 14 of which are novel. All classic infantile patients had two severe mutations. The most common mutation in the non-classic group was c.-32-13?T?>?G. It was associated with a milder course in this subgroup.

Conclusions

Disease manifestation strongly correlates with the nature of the GAA mutations, while the variable progression in non-classic Pompe disease is likely to be explained by yet unknown modifying factors. This study provides the first comprehensive dataset on the clinical course and the mutational spectrum of Pompe disease in Germany.     

High-level production of animal-free recombinant transferrin from Saccharomyces cerevisiae

Background

Microorganisms that are exposed to pollutants in the environment, such as metals/metalloids, have a remarkable ability to fight the metal stress by various mechanisms. These metal-microbe interactions have already found an important role in biotechnological applications. It is only recently that microorganisms have been explored as potential biofactories for synthesis of metal/metalloid nanoparticles. Biosynthesis of selenium (Se⁰) nanospheres in aerobic conditions by a bacterial strain isolated from the coalmine soil is reported in the present study.

Results

The strain CM100B, identified as Bacillus cereus by morphological, biochemical and 16S rRNA gene sequencing [GenBank:GU551935.1] was studied for its ability to generate selenium nanoparticles (SNs) by transformation of toxic selenite (SeO₃ ^2-) anions into red elemental selenium (Se⁰) under aerobic conditions. Also, the ability of the strain to tolerate high levels of toxic selenite ions was studied by challenging the microbe with different concentrations of sodium selenite (0.5 mM-10 mM). ESEM, AFM and SEM studies revealed the spherical Se⁰ nanospheres adhering to bacterial biomass as well as present as free particles. The TEM microscopy showed the accumulation of spherical nanostructures as intracellular and extracellular deposits. The deposits were identified as element selenium by EDX analysis. This is also indicated by the red coloration of the culture broth that starts within 2-3 h of exposure to selenite oxyions. Selenium nanoparticles (SNs) were further characterized by UV-Visible spectroscopy, TEM and zeta potential measurement. The size of nanospheres was in the range of 150-200 nm with high negative charge of -46.86 mV.

Conclusions

This bacterial isolate has the potential to be used as a bionanofactory for the synthesis of stable, nearly monodisperse Se⁰ nanoparticles as well as for detoxification of the toxic selenite anions in the environment. A hypothetical mechanism for the biogenesis of selenium nanoparticles (SNs) involving membrane associated reductase enzyme(s) that reduces selenite (SeO₃ ^2-) to Se⁰ through electron shuttle enzymatic metal reduction process has been proposed.     

A comparison of anti-HER2 IgA and IgG1 in vivo efficacy is facilitated by high N-glycan sialylation of the IgA

Monomeric IgA has been proposed as an alternative antibody format for cancer therapy. Here, we present our studies on the production, purification and functional evaluation of anti-HER2 IgA antibodies as anti-cancer agents in comparison to the anti-HER2 IgG1 trastuzumab. MALDI-TOF MS analysis showed profound differences in glycosylation traits across the IgA isotypes and cell lines used for production, including sialylation and linkage thereof, fucosylation (both core and antennary) and the abundance of high-mannose type species. Increases in sialylation proved to positively correlate with in vivo plasma half-lives. The polymerization propensity of anti-HER2 IgA2m2 could be suppressed by an 18-aa deletion of the heavy chain tailpiece - coinciding with the loss of high-mannose type N-glycan species - as well as by 2 cysteine to serine mutations at positions 320 and 480. The HER2 F(ab')2-mediated anti-proliferative effect of the IgA2m1 and IgA2m2 subtypes was similar to IgG1, whereas the IgA1 isotype displayed considerably lower potency and efficacy. The Fc-mediated induction of antibody-dependent cell-mediated cytotoxicity (ADCC) using human whole blood ADCC assays did not demonstrate such clear differences between the IgA isotypes. However, the potency of the anti-HER2 IgA antibodies in these ADCC assays was found to be significantly lower than that of trastuzumab. In vivo anti-tumor activity of the anti-HER2 IgA antibodies was compared to that of trastuzumab in a BT-474 breast cancer xenograft model. Multiple dosing and sialylation of the IgA antibodies compensated for the short in vivo half-life of native IgA antibodies in mice compared to a single dose of IgG1. In the case of the IgA2m2 antibody, the resulting high plasma exposure levels were sufficient to cause clear tumor stasis comparable to that observed for trastuzumab at much lower plasma exposure levels.     

In vitro test systems supporting the development of improved pest control methods: a case study with chemical mixtures and bivalve biofoulers

Using the bivalve macrofouler Corbicula fluminea, the suitability of in vitro testing as a stepping stone towards the improvement of control methods based on chemical mixtures was addressed in this study. In vitro cholinesterase (ChE) activity inhibition following single exposure of C. fluminea tissue to four model chemicals (the organophosphates dimethoate and dichlorvos, copper and sodium dodecyl phosphate [SDS]) was first assessed. Consequently, mixtures of dimethoate with copper and dichlorvos with SDS were tested and modelled; mixtures with ChE revealed synergistic interactions for both chemical pairs. These synergic combinations were subsequently validated in vivo and the increased control potential of these selected combinations was verified, with gains of up to 50% in C. fluminea mortality relative to corresponding single chemical treatments. Such consistency supports the suitability of using time- and cost-effective surrogate testing platforms to assist the development of biofouling control strategies incorporating mixtures.