Serum vaspin levels in women with and without gestational diabetes mellitus during pregnancy and postpartum

Although vaspin is regarded an insulin-sensitizing adipokine, its role in gestational diabetes mellitus (GDM) is currently unknown. We aimed to evaluate serum vaspin levels and their correlation with insulin resistance in women with and without GDM. Forty-four women with GDM [GDM Group ? 20 managed with diet only (GDM-diet) and 24 with diet plus insulin (GDM-insulin)] and 44 age-matched pregnant women with normal glucose tolerance (Control Group) were studied. Serum glucose, lipids, uric acid, insulin and vaspin were measured at the 2nd and 3rd trimester of pregnancy and postpartum. The quantitative insulin sensitivity check index (QUICKI) and homeostasis model of assessment–insulin resistance (HOMA-IR) were calculated. Circulating vaspin levels decreased significantly postpartum in all groups (p < 0.001), but did not differ between GDM or GDM Subgroups and Control Group in any time point. At the 3rd trimester of pregnancy vaspin was positively correlated to insulin (p = 0.022), HOMA-IR (p = 0.016) and triglycerides (p = 0.033) and negatively correlated to QUICKI (p = 0.016) in the GDM women, but not in the Controls. These correlations were not observed at the 2nd trimester or postpartum. Vaspin, in contrast to HOMA-IR, could not independently predict GDM in binary logistic regression. In patients with GDM, insulin treatment did not affect vaspin levels. In conclusion, our data suggest that vaspin levels gradually decrease from the 2nd trimester to postpartum; however, decreases are similar between women with or without GDM. Serum vaspin cannot independently predict GDM and it is not affected by the degree of glucose metabolism deregulation or the exogenous administration of insulin.     

Cutaneous Mucormycosis by Saksenaea vasiformis: An Unusual Case Report and Review of Literature

Mycopathologia - Saksenaea vasiformis is one of the numerous fungi of the Order Mucorales. Rapid progression and invasion of neighboring tissues are the most characteristic features of S....     

Development of a Cotton Honey-Based Spread by Controlling Compositional and Processing Parameters

Food Biophysics - Honey from cotton blossoms tends to crystallize rapidly resulting in a product with hard texture and low spreadability, even if it is processed via a controlled crystallization...     

LaTcOm: a web server for visualizing rare codon clusters in coding sequences

We present LaTcOm, a new web tool, which offers several alternative methods for 'rare codon cluster' (RCC) identification from a single and simple graphical user interface. In the current version, three RCC detection schemes are implemented: the recently described %MinMax algorithm and a simplified sliding window approach, along with a novel modification of a linear-time algorithm for the detection of maximally scoring subsequences tailored to the RCC detection problem. Among a number of user tunable parameters, several codon-based scales relevant for RCC detection are available, including tRNA abundance values from Escherichia coli and several codon usage tables from a selection of genomes. Furthermore, useful scale transformations may be performed upon user request (e.g. linear, sigmoid). Users may choose to visualize RCC positions within the submitted sequences either with graphical representations or in textual form for further processing. AVAILABILITY: LaTcOm is freely available online at the URL http://troodos.biol.ucy.ac.cy/latcom.html.     

Preferential pathways for light-trapping involving β-ligated chlorophylls

The magnesium atom of chlorophylls (Chls) is always five- or six-coordinated within chlorophyll-protein complexes which are the main light-harvesting systems of plants, algae and most photosynthetic bacteria. Due to the presence of stereocenters and the axial ligation of magnesium the two faces of Chls are diastereotopic. It has been previously recognized that the α-configuration having the magnesium ligand on the opposite face of the 17-propionic acid moiety is more frequently encountered and is more stable than the more seldom β-configuration that has the magnesium ligand on the same face [T.S. Balaban, P. Fromme, A.R. Holzwarth, N. Krauβ, V.I. Prokhorenko, Relevance of the diastereotopic ligation of magnesium atoms in chlorophylls in Photosystem I, Biochim. Biophys. Acta (Bioenergetics), 1556 (2002) 197-207; T. Oba, H. Tamiaki, Which side of the π-macrocycle plane of (bacterio)chlorophylls is favored for binding of the fifth ligand? Photosynth. Res. 74 (2002) 1-10]. In photosystem I only 14 Chls out of a total of 96 are in a β-configuration and these occupy preferential positions around the reaction center. We have now analyzed the α/β dichotomy in the homodimeric photosystem II based on the 2.9 Å resolution crystal structure [A. Guskov, J. Kern, A. Gabdulkhakov, M. Broser, A. Zouni, W. Saenger, Cyanobacterial photosystem II at 2.9 Å resolution: role of quinones, lipids, channels and chloride, Nature Struct. Mol. Biol. 16 (2009) 334-342] and find that out of 35 Chls in each monomer only 9 are definitively in the β-configuration, while 4 are uncertain. Ab initio calculations using the approximate coupled-cluster singles-and-doubles model CC2 [O. Christiansen, H. Koch, P. Jørgensen, The second-order approximate coupled cluster singles and doubles model CC2, Chem. Phys. Lett. 243 (1995) 409-418] now correctly predict the absorption spectra of Chls a and b and conclusively show for histidine, which is the most frequent axial ligand of magnesium in chlorophyll-protein complexes, that only slight differences (< 4 nm) are encountered between the α- and β-configurations. Significant red shifts (up to 50 nm) can, however, be encountered in excitonically coupled β-β-Chl dimers. Surprisingly, in both photosystems I and II very similar “special” β-β dimers are encountered at practically the same distances from P700 and P680, respectively. In purple bacteria LH2, the B850 ring is composed exclusively of such tightly coupled β-bacteriochlorophylls a. A statistical analysis of the close contacts with the protein matrix (< 5 Å) shows significant differences between the α- and β-configurations and the subunit providing the axial magnesium ligand. The present study allows us to conclude that the excitation energy transfer in light-harvesting systems, from a peripheral antenna towards the reaction center, may follow preferential pathways due to structural reasons involving β-ligated Chls.     

Effect of the Novel Influenza A (H1N1) Virus in the Human Immune System

Background

The pandemic by the novel H1N1 virus has created the need to study any probable effects of that infection in the immune system of the host.

Methodology/Principal Findings

Blood was sampled within the first two days of the presentation of signs of infection from 10 healthy volunteers; from 18 cases of flu-like syndrome; and from 31 cases of infection by H1N1 confirmed by reverse RT-PCR. Absolute counts of subtypes of monocytes and of lymphocytes were determined after staining with monoclonal antibodies and analysis by flow cytometry. Peripheral blood mononuclear cells (PBMCs) were isolated from patients and stimulated with various bacterial stimuli. Concentrations of tumour necrosis factor-alpha, interleukin (IL)-1beta, IL-6, IL-18, interferon (FN)-alpha and of IFN-gamma were estimated in supernatants by an enzyme immunoassay. Infection by H1N1 was accompanied by an increase of monocytes. PBMCs of patients evoked strong cytokine production after stimulation with most of bacterial stimuli. Defective cytokine responses were shown in response to stimulation with phytohemagglutin and with heat-killed Streptococcus pneumoniae. Adaptive immune responses of H1N1-infected patients were characterized by decreases of CD4-lymphocytes and of B-lymphocytes and by increase of T-regulatory lymphocytes (Tregs).

Conclusions/Significance

Infection by the H1N1 virus is accompanied by a characteristic impairment of the innate immune responses characterized by defective cytokine responses to S.pneumoniae. Alterations of the adaptive immune responses are predominated by increase of Tregs. These findings signify a predisposition for pneumococcal infections after infection by H1N1 influenza.     

Chromatin-associated ornithine decarboxylase at early stages of growth and differentiation of etiolated mono- and dicotyledonous plants

Ornithine decarboxylase (ODC) of barley, corn, bean and pea plants was associated with chromatin at early stages of growth. In corn, bean and pea plants the chromatin of roots possessed ODC with the highest specific activity of 30–65 units per mg protein. After 200 h of growth ODC activity of chromatin declined, while ODC activity of cytosol increased linearly to 4–19 units per mg protein. ODC activity of either chromatin or cytosol of shoots in the above mentioned plants was usually low, 1–2 units per mg protein and only at the beginning of shoot growth (96 h) did pea chromatin have high ODC activity (14 units per mg protein). In these plants ODC was tightly bound to chromatin and could not be extracted with different concentrations of NaCl (0.1–1.0 M) or non-ionic detergent (Triton X100, Tween 20) but could be extracted by freezing and thawing with satisfactory recovery.     

Model-based intensification of a fed-batch microbial process for the maximization of polyhydroxybutyrate (PHB) production rate

An integrated metabolic–polymerization–macroscopic model, describing the microbial production of polyhydroxybutyrate (PHB) in Azohydromonas lata bacteria, was developed and validated using a comprehensive series of experimental measurements. The model accounted for biomass growth, biopolymer accumulation, carbon and nitrogen sources utilization, oxygen mass transfer and uptake rates and average molecular weights of the accumulated PHB, produced under batch and fed-batch cultivation conditions. Model predictions were in excellent agreement with experimental measurements. The validated model was subsequently utilized to calculate optimal operating conditions and feeding policies for maximizing PHB productivity for desired PHB molecular properties. More specifically, two optimal fed-batch strategies were calculated and experimentally tested: (1) a nitrogen-limited fed-batch policy and (2) a nitrogen sufficient one. The calculated optimal operating policies resulted in a maximum PHB content (94% g/g) in the cultivated bacteria and a biopolymer productivity of 4.2 g/(l h), respectively. Moreover, it was demonstrated that different PHB grades with weight average molecular weights of up to 1513 kg/mol could be produced via the optimal selection of bioprocess operating conditions.