Conformal stereotactic radiosurgery therapy: plan evaluation methods and results

The purpose of our study was the objective evaluation of micro-multileaf collimator (mMLC)-based stereotactic radiosurgery treatment plans. Forty-seven patients, 71 lesions received static beam conformal stereotactic radiosurgery treatment in our institute between November 2005 and June 2008. Target volume and organs at risk were outlined on a MRI-CT image fusion basis. BrainSCAN 5.31 system (BrainLAB AG, Heimstetten, Germany) was used for treatment planning, Elekta Presice TS linear accelerator (Elekta Oncology Systems Ltd, Crawley, UK) and BrainLAB m3 mMLC were used for treatment delivery. An invasive head frame, mounted to the treatment table, was used with four screws for patient head fixation. Treatment plans were analysed with objective parameters, such as conformal index (COIN), homogeneity index (HI), coverage index (CI) and healthy tissue relative overdose factor (HTOF) tools. x2 tests were performed between COIN, HI and the geometrical parameters of the target volume (lesion volume - LV, lesion-organ distance - LOD, lesion deformity index - LDI). Mean value of COIN, HI, HTOF and CI was 0.52 (SD 0.13), 1.16 (SD 0.1), 0.88 (SD 0.53), and 0.94 (SD 0.11), respectively. COIN significantly correlated with (p<0.001 in all three cases), while HI was independent of LV, LOD, LDI (p=0.94; 0.14 and 0.72). COIN is similar, HTOF is less than data from the literature. According to our results geometrical parameters of the target volume (size, location, deformation) significantly influence the COIN, but they have no effect on HI.     

Challenges in oncologic plastic surgery of the breast

Breast screening programs along with advances in diagnostic methods and oncologic treatment have resulted in full recovery for a decisive number of patients diagnosed with early-stage breast cancer. The results of the ultra-radical-, followed by the breast conserving era pose new opportunities and challenges for the oncologic breast surgeon. The focus of oncoplastic surgery is not only on the tumor, but also on the female patient, allowing for individualized immediate breast reconstruction with acceptable esthetic result following radical tumor exstirpation. Modern procedures differ both in concept and technique from that of traditional breast surgery. This paper provides a comprehensive and detailed overview of reconstructive and oncoplastic breast surgery.     

Subcellular Metabolite and Lipid Analysis of Xenopus laevis Eggs by LAESI Mass Spectrometry

Xenopus laevis eggs are used as a biological model system for studying fertilization and early embryonic development in vertebrates. Most methods used for their molecular analysis require elaborate sample preparation including separate protocols for the water soluble and lipid components. In this study, laser ablation electrospray ionization (LAESI), an ambient ionization technique, was used for direct mass spectrometric analysis of X. laevis eggs and early stage embryos up to five cleavage cycles. Single unfertilized and fertilized eggs, their animal and vegetal poles, and embryos through the 32-cell stage were analyzed. Fifty two small metabolite ions, including glutathione, GABA and amino acids, as well as numerous lipids including 14 fatty acids, 13 lysophosphatidylcholines, 36 phosphatidylcholines and 29 triacylglycerols were putatively identified. Additionally, some proteins, for example thymosin β4 (Xen), were also detected. On the subcellular level, the lipid profiles were found to differ between the animal and vegetal poles of the eggs. Radial profiling revealed profound compositional differences between the jelly coat vitelline/plasma membrane and egg cytoplasm. Changes in the metabolic profile of the egg following fertilization, e.g., the decline of polyamine content with the development of the embryo were observed using LAESI-MS. This approach enables the exploration of metabolic and lipid changes during the early stages of embryogenesis.     

Biofilm formation and dispersal in Gram-positive bacteria

Biofilms are structured communities of bacteria, which are adhered to a surface and embedded in a self-produced matrix of extracellular polymeric substances. Since biofilms are very resistant to antimicrobial agents, they are at the basis of a range of problems, including quality and safety issues in food industry. Recently, major advances have been made in elucidating the different structural components of the biofilm matrix, the regulatory pathways involved in biofilm formation, and signaling molecules involved in biofilm formation and dispersal, which provide opportunities for prevention and control of these biofilms in the food industry.     

Comparative analysis of the complete mitochondrial genomes of Aspergillus niger mtDNA type 1a and Aspergillus tubingensis mtDNA type 2b.

To understand the differences in the organization of mitochondrial genomes of the very closely related Aspergillus niger and Aspergillus tubingensis species, we determined the complete genome sequence of the 1a mtDNA type of A. niger and 2b mtDNA type of A. tubingensis and now we provide a comparative analysis of the two mtDNAs. We found that (1) the organization (gene content and order) of the two genomes is almost identical and (2) the size difference between them is principally attributed to the different intron content of their cox1, atp9 and ndh4L genes.     

High-Density Lipoprotein Function in Exudative Age-Related Macular Degeneration

PurposeHigh-density lipoproteins (HDL) have long been implicated in the pathogenesis of age-related macular degeneration (AMD). However, conflicting results have been reported with regard to the associations of AMD with HDL-cholesterol levels. The present study is the first to assess HDL composition and metrics of HDL function in patients with exudative AMD and control patients.MethodsBlood samples were collected from 29 patients with exudative AMD and 26 age-matched control patients. Major HDL associated apolipoproteins were determined in apoB-depleted serum by immunoturbidimetry or ELISA, HDL-associated lipids were quantified enzymatically. To get an integrated measure of HDL quantity and quality, we assessed several metrics of HDL function, including cholesterol efflux capacity, anti-oxidative and anti-inflammatory activities using apoB-depleted serum from study participants.ResultsIn our study, we observed that the HDL associated acute phase protein serum amyloid A (SAA) was significantly increased in AMD patients (p<0.01), whereas all other assessed apolipoproteins including ApoA-I, apoA-II, apoC-II, apoC-III and apoE as well as major HDL associated lipids were not altered. HDL efflux capacity, anti-oxidative capacity and arylesterase activity were not different in AMD patients when compared with the control group. The ability of apoB-depleted serum to inhibit monocyte NF-κB expression was significantly improved in AMD patients (mean difference (MD) -5.6, p<0.01). Moreover, lipoprotein-associated phospholipase A2 activity, a marker of vascular inflammation, was decreased in AMD subjects (MD -24.1, p<0.01).ConclusionsThe investigated metrics of HDL composition and HDL function were not associated with exudative AMD in this study, despite an increased content of HDL associated SAA in AMD patients. Unexpectedly, anti-inflammatory activity of apoB-depleted serum was even increased in our study. Our data suggest that the investigated parameters of serum HDL function showed no significant association with exudative AMD. However, we cannot exclude that alterations in locally produced HDL may be part of the AMD pathogenesis.     

Bacillus Calmette-Guérin plus interleukin-2 and/or granulocyte/macrophage-colony-stimulating factor enhances immunocompetent cell production of interferon-γ, which inhibits B16F10 melanoma cell growth in vitro

 Although immunotherapy with bacillus Calmette Guérin (BCG) is an established adjuvant treatment for malignant melanoma, the mechanism of its role in this process is unclear. To investigate the possible contribution of tumor-inhibitory cytokines induced by BCG, B16F10 melanoma cell growth in culture was assessed in response to purified cytokines and conditioned media of BCG-stimulated splenocytes. Interferon-γ (IFNγ) was the most potent single agent (IC₅₀≈50 pg/ml). Tumor necrosis factor α was substantially weaker (IC50>10 ng/ml) but provided synergy with IFNγ. None of the other cytokines such as interleukin-2 (IL-2), IL-4, IL-6, IL-10, IL-12, or granulocyte/macrophage-colony-stimulating factor had direct antitumor activity against B16F10 melanoma cells. However, when IL-2 and/or GM-CSF were combined with BCG either by exogenous addition or through endogenous production by novel cytokine-secreting recombinant BCG (rBCG), a substantial increase in INFγ production by splenocytes was observed. Antitumor activity of this conditioned medium directly correlated with IFNγ concentration and was completely blocked by neutralizing antibody to IFNγ. These results suggest that BCG may exert part of its antitumor action on melanoma through the induction of IFNγ, which can be greatly enhanced through the concomitant addition of IL-2 and/or GM-CSF. Furthermore, by utilizing rBCG that secrete these cytokines, it may be possible to potentiate the antitumor effect of BCG directly at the site of BCG inoculation. Received: 29 January 1996 / Accepted: 9 April 1996     

The protective layer of biofilm: a repellent function for a new class of amphiphilic proteins

Bacteria can survive harsh conditions when growing in complex communities of cells known as biofilms. The matrix of the biofilm presents a scaffold where cells are attached to each other and to the surface. The biofilm matrix is also a protective barrier that confers tolerance against various antimicrobial agents. In this issue of Molecular Microbiology, Kobayashi and Iwano (2012) show that the liquid permeability of Bacillus subtilis biofilms is determined by a small secreted protein, i.e. BslA (formerly called YuaB). BslA is important for the proper development of biofilms, but unlike exopolysaccharide and TasA, is not directly involved in cell cluster formation, and is synthesized following the production of exopolysaccharide and amyloid fibres. The amphiphilic BslA protein forms a polymer in vitro and localizes in vivo to the surface of the biofilm. The microstructures of the biofilm wrinkles are reduced in the bslA mutant strain and the liquid repellency of the biofilm surface is diminished. Exogenously added BslA(42-181) protein complements the bslA mutation and restores not only water repellency, but also the formation of aerial structures. This study demonstrates that amphiphilic proteins have an important role in liquid repellency of biofilms and it suggests that these polymers contribute to antimicrobial resistance.     

Individual variation and the resolution of conflict over parental care in penduline tits

Eurasian penduline tits (Remiz pendulinus) have an unusually diverse breeding system consisting of frequent male and female polygamy, and uniparental care by the male or the female. Intriguingly, 30 to 40 per cent of all nests are deserted by both parents. To understand the evolution of this diverse breeding system and frequent clutch desertion, we use 6 years of field data to derive fitness expectations for males and females depending on whether or not they care for their offspring. The resulting payoff matrix corresponds to an asymmetric Snowdrift Game with two alternative evolutionarily stable strategies (ESSs): female-only and male-only care. This, however, does not explain the polymorphism in care strategies and frequent biparental desertion, because theory predicts that one of the two ESSs should have spread to fixation. Using a bootstrapping approach, we demonstrate that taking account of individual variation in payoffs explains the patterns of care better than a model based on the average population payoff matrix. In particular, a model incorporating differences in male attractiveness closely predicts the observed frequencies of male and female desertion. Our work highlights the need for a new generation of individual-based evolutionary game-theoretic models.     

Bioenergetic analysis of isolated cerebrocortical nerve terminals on a microgram scale: spare respiratory capacity and stochastic mitochondrial failure

Pre-synaptic nerve terminals (synaptosomes) require ATP for neurotransmitter exocytosis and recovery and for ionic homeostasis, and are consequently abundantly furnished with mitochondria. Pre-synaptic mitochondrial dysfunction is implicated in a variety of neurodegenerative disorders, although there is no precise definition of the term 'dysfunction'. In this study, we test the hypothesis that partial restriction of electron transport through Complexes I and II in synaptosomes to mimic possible defects associated with Parkinson's and Huntington's diseases respectively, sensitizes individual terminals to mitochondrial depolarization under conditions of enhanced proton current utilization, even though these stresses are within the respiratory capacity of the synaptosomes when averaged over the entire population. We combine two novel techniques, firstly using a modification of a plate-based respiration and glycolysis assay that requires only microgram quantities of synaptosomal protein, and secondly developing an improved method for fluorescent imaging and statistical analysis of single synaptosomes. Conditions are defined for optimal substrate supply to the in situ mitochondria within mouse cerebrocortical synaptosomes, and the energetic demands of ion cycling and action-potential firing at the plasma membrane are additionally determined.